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特開2024-163027対象物の幾何学的パラメータを測定する測定装置および方法
(19)【発行国】日本国特許庁(JP)
(12)【公報種別】公開特許公報(A)
(11)【公開番号】P2024163027
(43)【公開日】2024-11-21
(54)【発明の名称】対象物の幾何学的パラメータを測定する測定装置および方法
(51)【国際特許分類】
G01B 11/08 20060101AFI20241114BHJP
G01B 11/06 20060101ALI20241114BHJP
【ＦＩ】
G01B11/08 Z
G01B11/06 Z
【審査請求】未請求
【請求項の数】22
【出願形態】ＯＬ
【外国語出願】
(21)【出願番号】P 2024065702
(22)【出願日】2024-04-15
(31)【優先権主張番号】23172870
(32)【優先日】2023-05-11
(33)【優先権主張国・地域又は機関】EP
(71)【出願人】
【識別番号】511082609
【氏名又は名称】シコラ アーゲー
(74)【代理人】
【識別番号】100080182
【弁理士】
【氏名又は名称】渡辺 三彦
(74)【代理人】
【識別番号】100142572
【弁理士】
【氏名又は名称】水内 龍介
(72)【発明者】
【氏名】フランク クリスチャン
(72)【発明者】
【氏名】シュー トビアス コリャ
(72)【発明者】
【氏名】シコラ ハラルド
【テーマコード（参考）】
2F065
【Ｆターム（参考）】
2F065AA26
2F065AA27
2F065AA30
2F065BB08
2F065FF02
2F065FF46
2F065FF65
2F065GG01
2F065HH15
2F065JJ02
2F065JJ15
2F065MM09
2F065PP22
(57)【要約】 （修正有）
【課題】対象物のさまざまな位置で、柔軟かつ信頼できる方法で幾何学的パラメータを決定することができる測定装置と方法を提供する。
【解決手段】特に管状対象物２４の幾何学的パラメータ、特に内径、外径および／または壁厚を測定するための測定装置であって、テラヘルツ放射が対象物に部分的に反射するように、テラヘルツ放射を対象物に放射するための送信装置と、送信装置から対象物に放射されたテラヘルツ放射を受信するための受信装置を有するトランシーバ１０を備え、測定装置は、トランシーバ１０と、テラヘルツ放射が対象物の少なくとも一部分を通過した後、反射する反射器１６を支持するホルダ１４を備え、ホルダ１４は、対象物の幾何学的パラメータを測定するための測定装置が対象物と反対方向に置かれるように、トランシーバ１０と反射器１６が、対象物の異なる側または対象物の壁上に互いに反対になるように、設計されている。
【選択図】図１
【解決手段】特に管状対象物２４の幾何学的パラメータ、特に内径、外径および／または壁厚を測定するための測定装置であって、テラヘルツ放射が対象物に部分的に反射するように、テラヘルツ放射を対象物に放射するための送信装置と、送信装置から対象物に放射されたテラヘルツ放射を受信するための受信装置を有するトランシーバ１０を備え、測定装置は、トランシーバ１０と、テラヘルツ放射が対象物の少なくとも一部分を通過した後、反射する反射器１６を支持するホルダ１４を備え、ホルダ１４は、対象物の幾何学的パラメータを測定するための測定装置が対象物と反対方向に置かれるように、トランシーバ１０と反射器１６が、対象物の異なる側または対象物の壁上に互いに反対になるように、設計されている。
【選択図】図１
【特許請求の範囲】
【請求項1】
平板状またはストランド状、特に管状の対象物（２４）の幾何学的パラメータ、特に内径および／または外径および／または壁厚を測定するための測定装置であって、テラヘルツ放射が前記対象物（２４）によって少なくとも部分的に反射されるように、前記対象物にテラヘルツ放射を放射するための送信装置を有するトランシーバ（１０）と、前記送信装置によって前記対象物（２４）に放射された前記テラヘルツ放射を受信するための受信装置とを備え、前記測定装置は、測定者にとって持ち運び可能である、測定装置であって、
前記測定装置は、前記トランシーバ（１０）と、前記テラヘルツ放射が前記対象物（２４）の少なくとも一部分を通過した後に、前記送信装置によって放射された前記テラヘルツ放射を反射するための反射器（１６、３２）とを支持するホルダ（１４，３０，３４）備え、前記ホルダ（１４、３０、３４）は、前記対象物（２４）の前記幾何学的パラメータを測定するための前記測定装置が、前記トランシーバ（１０）と前記反射器（１６、３２）とが前記対象物（２４）または前記対象物（２４）の壁上の異なる側で互いに対向するように、前記対象物（２４）に対して配置されるように設計されていることを特徴とする、測定装置。
前記測定装置は、前記トランシーバ（１０）と、前記テラヘルツ放射が前記対象物（２４）の少なくとも一部分を通過した後に、前記送信装置によって放射された前記テラヘルツ放射を反射するための反射器（１６、３２）とを支持するホルダ（１４，３０，３４）備え、前記ホルダ（１４、３０、３４）は、前記対象物（２４）の前記幾何学的パラメータを測定するための前記測定装置が、前記トランシーバ（１０）と前記反射器（１６、３２）とが前記対象物（２４）または前記対象物（２４）の壁上の異なる側で互いに対向するように、前記対象物（２４）に対して配置されるように設計されていることを特徴とする、測定装置。
【請求項2】
前記ホルダ（１４，３０，３４）がＣ字形であることを特徴とする請求項１に記載の測定装置。
【請求項3】
前記ホルダ（１４，３０，３４）は、前記測定装置を配置するために前記対象物（２４）の端面に対向して配置可能なストップを形成することを特徴とする、請求項１または２のいずれかに１項に記載の測定装置。
【請求項4】
前記トランシーバ（１０）および／または前記反射器（１６，３２）が、前記ホルダ（１４，３０，３４）上に長手方向に変位可能な方法で取り付けられていることを特徴とする、請求項１から３のいずれか１項に記載の測定装置。
【請求項5】
前記トランシーバ（１０）および／または前記反射器（１６，３２）が、前記ホルダ（１４，３０，３４）上に着脱可能に配置されていることを特徴とする、請求項１から４のいずれか１項に記載の測定装置。
【請求項6】
前記反射器（１６、３２）は、前記測定装置が前記対象物（２４）と対向して配置された状態で前記テラヘルツ放射が通過し、前記反射器（１６，３２）に隣接する前記対象物（２４）の壁から離れて配置されていることを特徴とする、請求項１から５のいずれか１項に記載の測定装置。
【請求項7】
前記ホルダ（１４，３０，３４）は、前記トランシーバ（１０）および／または前記反射器（１６，３２）が前記対象物（２４）に対向して配置された状態で前記対象物（２４）の表面上に載る少なくとも１つの支持体を備えることを特徴とする、請求項１から６のいずれか１項に記載の測定装置。
【請求項8】
前記少なくとも１つの支持体は、前記対象物（２４）に対して配置された状態で前記対象物（２４）の前記表面上に載る少なくとも１つのガイドローラ（１８、２０）を備えることを特徴とする、請求項７に記載の測定装置。
【請求項9】
前記少なくとも１つの支持体は、前記対象物（２４）の異なる寸法に適合するように調整可能であることを特徴とする、請求項７または８のいずれか１項に記載の測定装置。
【請求項10】
前記少なくとも１つの支持体は、互いに間隔を隔てて配置され予荷重に対抗して押し広げ可能な少なくとも２つの支持部を備えることを特徴とする、請求項９に記載の測定装置。
【請求項11】
前記ホルダ（１４，３０，３４）を備えた前記測定装置を、前記対象物（２４）に接触させることなく測定の過程で方向付けることによって、少なくとも１つのセンサも設けられていることを特徴とする、請求項１から１０のいずれか１項に記載の測定装置。
【請求項12】
前記少なくとも１つのセンサは、少なくとも１つの光学センサおよび／または少なくとも１つの慣性センサおよび／または少なくとも１つの位置センサを備えることを特徴とする、請求項１１に記載の測定装置。
【請求項13】
反射器（１６、３２）が円筒部の形状を有することを特徴とする、請求項１から１２のいずれか１項に記載の測定装置。
【請求項14】
前記反射器（１６，３２）は、前記送信装置によって放射される前記テラヘルツ放射に対して部分的に透過であることを特徴とする、請求項１から１３のいずれか１項に記載の測定装置。
【請求項15】
前記対象物を製造するための製造装置上に固定的に配置することができ、前記トランシーバ（１０）および／または前記ホルダ（１４，３０，３４）を着脱可能に固定することができる保持部（４２）をさらに備えることを特徴とする、請求項１から１４のいずれか１項に記載の測定装置。
【請求項16】
前記受信装置によって受信された測定値に基づいて、前記対象物（２４）の幾何学的パラメータ、特に壁厚および／または内径および／または外径を決定するように設計された評価装置（２６）をさらに備えることを特徴とする、請求項１から１５のいずれか１項に記載の測定装置。
【請求項17】
前記評価装置（２６）は、放射が前記対象物（２４）を通過した状態で前記送信装置によって放射され前記受信装置によって受信された前記テラヘルツ放射の遅延時間と、前記放射が前記対象物（２４）を通過していない状態で前記送信装置によって放射され前記受信装置によって受信されたテラヘルツ放射の遅延時間との比較から、前記対象物（２４）の屈折率を決定するようにさらに設計されていることを特徴とする、請求項１６に記載の測定装置。
【請求項18】
前記測定装置は、前記受信装置によって受信された測定値を前記測定装置とは別の評価装置（２６）に送信するための、および／または、前記測定装置に内蔵されている評価装置（２６）によって評価されたデータを前記測定装置とは別の制御装置に送信するための、無線送信装置を備えることを特徴とする、請求項１から１７のいずれか１項に記載の測定装置。
【請求項19】
請求項１から１８のいずれか一項に記載の測定装置と、前記対象物（２４）とを備える、システム。
【請求項20】
前記測定装置の測定領域を通って前記対象物（２４）を長手方向に搬送する搬送装置をさらに備えることを特徴とする、請求項１９に記載のシステム。
【請求項21】
請求項１から１８のいずれか一項に記載の測定装置を用いて、または請求項１９または２０のいずれか一項に記載のシステムを用いて、平板状またはストランド状、特に管状の対象物（２４）の幾何学的パラメータ、特に内径および／または外径および／または壁厚を測定する、方法。
【発明の詳細な説明】
【技術分野】
【0001】
本発明は、平板状またはストランド状、特に管状対象物の幾何学的パラメータ、特に内径および／または外径および／または壁厚を測定するための測定装置であって、測定装置は、テラヘルツ放射が対象物によって少なくとも部分的に反射されるように、テラヘルツ放射を対象物に放射するための送信装置と、送信装置によって対象物に放射されたテラヘルツ放射を受信するための受信装置を有するトランシーバを備え、測定装置は、操作者が持ち運び可能な測定装置である、測定装置に関する。
【0002】
本発明はまた、平板状またはストランド状、特に管状対象物の幾何学的パラメータ、特に内径および／または外径および／または壁厚を測定するための方法に関する。
【背景技術】
【0003】
例えば、押出ラインにおけるプラスチックパイプの製造では、例えば壁厚や内径または外径といった幾何学的パラメータを、柔軟な方法で、早い段階で、製造ラインの様々な場所で測定できることが望ましい。この目的のために、テラヘルツ放射を対象物に放射し、対象物によって反射されたテラヘルツ放射を受信する、テラヘルツ測定装置が従来技術から知られている。例えば、壁厚や直径などの幾何学的パラメータを、遅延時間測定に基づいて決定することができる。
【0004】
製造ライン上の異なる場所で、幾何学的パラメータを迅速かつ柔軟に測定するためには、測定者が持ち運びできる携帯型装置が有用である。携帯型装置は、独国特許出願公開第１０２０１６１１９７２８号明細書（特許文献１）から知られている。この装置は、測定される対象物上に、装置を位置決めするための複数の接触点を有する支持外形を有する。例えば、対象物の材料の屈折率が既知であると仮定した場合に、既知の携帯型装置を、幾何学的な壁厚を決定するために使用することができる。
【0005】
ＰＥ、ＰＰ、ＨＤＰＥ、ＰＶＤＦ、ＰＴＦＥ、ＰＶＣなど、頻繁に使用されるプラスチック材料については、標準的な条件下で信頼性の高い屈折率値が知られている。原則として、屈折率は、材料の温度、凝集状態、したがって密度、さらに使用周波数に依存する。しかし、実際には、紫外線に対するより適切な保護や帯電防止などの目的で、プラスチック材料に添加物が加えられることが多い。添加物は屈折率を変化させ、添加物の添加は、供給されるプラスチック材料中の、規格外の混合物または添加物の割合の変動により、しばしば変動する。この種のパイプの幾何学的パラメータを測定するための要件は、ＤＩＮ ＥＮ ＩＳＯ ３１２６規格に定められている。要求される測定精度のレベルは厳しい。添加物による屈折率の変化は、屈折率が一定であると仮定した場合、既知の携帯型機器による壁厚測定を大きく歪める可能性がある。したがって、プラスチック材料の壁厚の信頼性の高い測定値を得るためには、壁厚の測定位置で屈折率を直接検出し、それを幾何学的壁厚の計算に利用することが急務である。
【0006】
屈折率を決定するために、あるいはむしろ屈折率に関して第一のテラヘルツ測定装置を調整するために、独国特許発明第１０２０２２１００６５０号明細書（特許文献２）では、機械的触覚測定装置を用いて既に冷却されたパイプ片の壁厚測定を行うことが提案されており、これによって冷却されたパイプ片を測定する第二のテラヘルツ測定装置が調整される。これにより、第一のテラヘルツ測定装置を測定することができる。このようにして、測定対象物の個々の屈折率を測定場所で決定し、正確な幾何学的パラメータを決定することができる。しかし、冷却されたパイプの最初の測定と最終測定との間の遅延時間が１時間以上であるため、調整手順は非常に時間がかかる。最後に、この方法では、最初の測定位置、すなわちプラスチック材料が部分的にしか固化していない、いわゆるホットゾーンでの屈折率の値が得られるだけである。プラスチック材料中の添加物の割合は別として、その温度、密度、材料の凝集状態も屈折率の値に影響を与える。
【先行技術文献】
【特許文献】
【0007】
【特許文献1】独国特許出願公開第１０２０１６１１９７２８号明細書
【特許文献2】独国特許発明第１０２０２２１００６５０号明細書
【特許文献3】国際公開第２０１６／１３９１５５号
【発明の概要】
【発明が解決しようとする課題】
【0008】
上記で述べた従来技術から進んで、本発明の目的は、前述したタイプの測定装置と方法を提供することであり、これによって、対象物のさまざまな位置で、柔軟かつ信頼できる方法で幾何学的パラメータを決定することができる。
【課題を解決するための手段】
【0009】
本発明は、請求項１および２１によって対象物を達成する。有利な実施形態は、従属請求項、明細書および図に開示されている。
【0010】
測定装置内の対象物は、トランシーバと、テラヘルツ放射が対象物の少なくとも一部を通過した後に送信装置から放射されたテラヘルツ放射を反射する反射器とを支えるホルダを有し、ホルダが、対象物の幾何学的パラメータを測定する測定装置が対象物とは反対方向に置かれるように、トランシーバと反射器が対象物の異なる側または壁上に互いに反対になるように、設計されている点で、目的を達成する。
【0011】
測定対象物は、例えば、円筒形や管状であってもよい。測定対象物はまた、平板状またはむしろ平面的な対象物であってもよい。対象物は、送信装置によって放射されるテラヘルツ放射に対して少なくとも部分的に透過であり、対象物に放射されたテラヘルツ放射が対象物の境界面で反射されるようになっている。テラヘルツ放射の一部は、対象物を通過し、反射器で反射された後、受信装置に戻り、ここで、対象物で反射された先の放射および放射成分が測定信号として受信される。送信装置と受信装置は、トランシーバに内蔵されるように設計され、特に同じ場所に配置される。対象物は、例えばＰＥ、ＰＰ、ＨＤＰＥ、ＰＴＦＥ、ＰＶＤＦ、ＰＶＣなどのプラスチック材料で構成されてもよい。しかし、対象物は、使用するテラヘルツ放射線に対して対象物が少なくとも部分的に透過させるならば、例えば、ガラス、セラミック材料、凍った水、木材、または様々な種類の建築材料でも構成されてもよい。テラヘルツ放射は、例えば、１ＧＨｚから６ＴＨｚの周波数範囲、特に１０ＧＨｚから１．５ＴＨｚの周波数範囲の放射線を放出することができる。対象物は、測定装置の測定領域を通って長手方向に搬送される。例えば、対象物は、押出装置内で製造され、例えば、押出ライン内にある間に、本発明による測定装置あるいは代わりに本発明による方法によって測定される。対象物は、本発明による測定装置あるいは代わりに本発明による方法による測定時に、流動性成分、すなわち完全に冷却されていないまたはむしろ固化されていない成分を含んでもよい。これは、特に、押出装置または押出ラインの第１冷却タンクから押し出された後すぐの測定に適用される。送信装置は、ＦＭＣＷテラヘルツ放射、特に広帯域テラヘルツ放射を放射してもよい。
【0012】
前述したように、受信装置は、送信装置によって放射され、対象物によって少なくとも部分的に反射されたテラヘルツ放射を受信する。同様に前述したように、受信装置は、対象物を通過したテラヘルツ放射を受信することもできる。本発明による測定装置は、特に測定中、測定者が持ち運び可能である。したがって、本発明による測定装置は、ハンドヘルド装置である。測定装置は、好ましくは、電気エネルギーのための独自のエネルギー供給源、特にバッテリー、好ましくは充電可能なバッテリーを有する。それ自体周知のように、受信装置は、例えば、対象物の異なる境界層で反射されたテラヘルツ放射の遅延時間測定に基づいて、対象物の幾何学的パラメータ、例えば、壁厚および／または内径および／または外径を決定し、結果をディスプレイ上に表示してもよい。この目的のために、測定装置は、以下により詳細に説明されるように、対応する評価装置を構成してもよい。
【0013】
本発明によれば、測定装置は、トランシーバと、放射線が対象物の少なくとも一部分を通過した後に、送信装置によって放射されたテラヘルツ放射を反射する反射器とを支持するホルダを含む。ホルダは、測定装置が測定プロセスのために対象物と反対方向に置かれるように、トランシーバと反射器が対象物のまたは対象物の壁上の異なる側に互いに反対になるように、設計されている。したがって、送信装置によって放射されたテラヘルツ放射は、対象物または対象物の壁を通過した後、反射器によって反射され、対象物または対象物の壁を再び通過した後、テラヘルツ放射は、トランシーバ、特に受信装置に戻り、そこで上記放射が測定信号として検出される。以下に詳細に説明するように、このようにして、同じ場所で測定された対象物の材料の個々の屈折率を決定することが可能であり、したがって、例えば添加物の添加により、対象物の組成が変化する場合、あるいは、十分な精度で知られていない組成の場合でさえも、関連する幾何学的パラメータの信頼できる正確な測定値を決定することが可能である。同時に、ホルダを備えた携帯型測定装置の設計により、測定は、対象物上のあるいはむしろ対象物の製造ライン上の、ほぼ任意の位置で、測定者によって実行することができる。測定結果は信頼性が高く、すぐに利用できる。固定様式で配置された測定装置は、潜在的に測定結果を連続して用意することができるが、本発明による携帯型測定装置は、非常に柔軟な方法で信頼できる測定結果を達成することができる。トランシーバおよび反射器と同様にホルダを備えた本発明による設計によって、屈折率およびそれに基づく幾何学的パラメータの測定結果は、１回の測定ステップで得ることができる。したがって、製造ラインにおける対象物の受入れのための信頼性の高い文書化も可能である。
【0014】
前述した従来技術のハンドヘルド装置と比べて、本発明による測定装置は、対象物の屈折率が既知であると推定することに依存しない。むしろ、対象物の屈折率の正確な値は、測定場所自体で直接記録され、幾何学的パラメータの測定値の計算に含まれる。その結果、ＤＩＮ ＥＮ ＩＳＯ ３１２６規格の要求事項は完全に満たされる。
【0015】
トランシーバと反射器は、対象物に対向して配置された状態で、対象物の壁の異なる側に互いに対向して配置されることを条件として、測定装置は、例えば、製造後、すなわち管状対象物が必要な長さに切断される直前および切断された後でも、管状対象物の端部に配置することができる。反射器またはトランシーバは、その時、管状対象物の内部に配置され、２つのうちのもう一方は管状対象物の外面上に対向して配置される。本発明によれば、壁厚や直径に加えて、管状対象物の楕円率も、例えば、内径または外径を対象物の円周にわたって複数回測定することにより、製造中または製造後に幾何学的パラメータとして確実に決定することができる。この目的のために、測定装置を全体として回転させることもできるし、例えば、反射器を静止させたまま、トランシーバだけを例えば管状対象物の長手方向軸を中心に回転させることもできる。回転のために、測定装置は回転駆動装置を含んでもよい。対象物の外周を測定することにより、壁厚変動に加えて、例えば対象物の材料における不均一性、例えば対象物の外周にある添加物の不均一な分布を特定することが可能である。測定装置はまた、例えば、放射されたテラヘルツ放射と、反射器で反射された後に回収されたテラヘルツ放射を比較することによって、対象物によって引き起こされたテラヘルツ放射の吸収を検出することも可能である。このように、携帯型測定装置は、対象物またはむしろ対象物の材料が本発明による方法で測定可能かどうか、もし測定可能な場合、どの程度の厚さまで測定可能かを確認するのにもより適している。
【0016】
原則的に、携帯型装置は、大小の対象物、もし可能ならば、対象物の表面から短い距離での測定にも適していなければならない。トランシーバのアンテナは、したがって、好ましくは２０～３０ｄＢｉの高利得と、それに伴う振幅で十分な感度を持つべきである。受信信号の過変調を防ぐために、受信信号の関連状況に適応できる送信電力の閉ループ制御が有用である。十分に高速な制御は有用であり、例えば、パイプの前後両面の壁厚に適合した異なる送信電力で測定プロセスを実行することができる。
【0017】
特に実用的な実施形態によれば、ホルダはＣ字型であってもよい。そして、トランシーバと反射器は、Ｃ字型ホルダの対向する自由端に配置することができる。この種のＣ字型ホルダは、例えばプラスチック材料、例えば炭素繊維強化プラスチック材料で構成されてもよい。測定装置のＣ字型または湾曲型ホルダが十分に大きいことを条件として、トランシーバと反射器は、例えば、管状対象物の測定中に、対象物の対向する外面に配置することができる。
【0018】
ホルダは、測定装置を配置するために、対象物の端面に対向して置くストップを形成してもよい。このようにして、対象物、特に平坦な対象物の端面または既に長さに合わせて切断されたパイプに対する測定装置の規定された位置が利用可能になる。例えば、パイプの壁厚を測定する場合、パイプの切断端から特定の距離、例えば少なくとも５０ｍｍが規定されることが多い。材料の応力が解放されるため、切断端自体の壁厚については信頼できる値がないことが多い。上記の設計により、切断端からの所定の距離を常に確実にすることができる。これは、例えばパイプの円周上の壁厚測定にも当てはまる。
【0019】
更なる実施形態によれば、異なる要件または条件に適応するために、対象物の端部、例えば切断端部からの距離を調整可能にするためには、トランシーバおよび／または反射器が、長手方向に変位可能な方法で、特に対象物に対して配置された状態で対象物の長手方向に、ホルダ上に取り付けられることが前提となる。
【0020】
更なる実施形態によれば、トランシーバおよび／または反射器は、ホルダ上に着脱可能に配置してもよい。このようにすれば、測定装置による測定は、必要に応じて反射器の有無にかかわらず可能である。反射器なしの測定は、例えば、対象物の材料の屈折率が、対応する測定がなくても十分に信頼できる範囲で既知である場合に有用である。例えば対象物の製造ライン内で、例えば管状対象物の押出ライン上に固定的に配置された反射器と、測定装置との組み合わせも可能である。この種の固定反射器は、例えば、対象物の押出ラインの始点、例えば、対象物が押出装置を出た後に最初の冷却を受ける最初の冷却タンクの出口に配置することができる。例えば、もし固定的に配置された反射器が、測定装置のトランシーバまたは測定装置のホルダの受信部も備えている場合、測定の正確な方向が常に確実となる。トランシーバ用ホルダと組み合わせた反射器を、例えば最初の冷却タンクの出口に直接、あるいは代わりにさらなる冷却タンクへの入口の上流に、あるいは代わりに製造ラインの冷却タンク間に、特に簡単に取り付けることができ、トランシーバと反射器間の測定経路の高い再現性が保証される。したがって、製造ラインのウォームゾーンでの正確な測定は可能であり、すなわち、対象物がまだ流動可能な成分を有し、したがってまだある程度の収縮やたるみがある状態での正確な測定が可能である。完全に固化した対象物の最終的な幾何学的パラメータから逸脱する可能性のある測定結果はこのウォームゾーンで得られるが、製造ラインを設定する際、特に、壁厚と、予測されるたるみに関して押出装置をプリセットする際に、重要な助けとなる。現在、巻尺を用いてウォームゾーンで管状対象物の直径の外法寸法を機械的に測定するのが一般的である。ここで、本発明により、測定装置を用いた簡単な非接触検出が可能になる。管状対象物の例えば外径の知識と、本発明による測定装置による内径の測定により、管状対象物の二重壁厚を確認でき、前部と後部の両方で検出された光学的壁厚値から個々の幾何学的壁厚値を決定することができる。トランシーバをホルダから取り外すことも、例えばトランシーバのバッテリーを再充電したり、別のトランシーバなどに交換したりするのに便利である。例えば、反射器をホルダに保持したまま使用し、測定経路内に折り畳んだり、測定経路外に折り畳んだりできるように、反射器を折り畳み式に設計することも考えられる。
【0021】
ホルダ上のトランシーバの着脱可能な設計は、使用目的に応じて、トランシーバを異なるホルダと組み合わせることができるという利点も有する。したがって、測定装置は、本発明による方法で設計され、異なる目的に最適化された、複数のホルダを含んでもよい。ホルダ上の反射器を着脱可能に配置することにより、反射器を、簡単かつ正確に使いやすくロックすることもできる。幾何学的寸法、壁厚、壁厚値および／または直径値を正確に決定するためには、屈折率の正確な決定が重要であり、すなわち、反射器への直接照射と、放射線が材料を通過した後の照射との間の遅延時間差の検出が違うことで、そのことが遅延時間を増加させる。このことは、反射器の距離の校正から実用化までの間に、数マイクロメートルの範囲の距離の変化が生じないことを意味する。プラスチック材料の屈折率が通常１．５、ガラスの屈折率が約２の場合、反射器の距離の変化の約３分の１がプラスチック材料の場合は壁厚値に含まれ、ガラスの場合は２分の１が含まれる。したがって、トランシーバと反射器の正確な配置が特に重要である。
【0022】
さらなる実施形態によれば、反射器は、反射器に隣接した対象物の壁および、測定装置が対象物に対向して配置された状態でテラヘルツ放射が通過する対象物の壁から、間隔を開けて配置してもよい。したがって、反射器と測定対象物の一部（例えば対象物の壁）との間には一定の距離がある。このようにして、反射器のエコーと、例えば管状対象物の内壁のような、離間した表面のエコーとを、測定信号において確実に分離することができる。
【0023】
ホルダはさらに、トランシーバおよび／または反射器が、対象物に対向して配置された状態で、対象物の表面上に基づく場合に、少なくとも１つの支持体を含んでもよい。この種の支持体のおかげで、測定対象物に対するトランシーバおよび／または反射器の規定の配置またはむしろ位置が保証される。少なくとも１つの受け部は、例えば、少なくとも１つのガイドランナーまたはむしろスキッドを含んでもよい。また、例えば、少なくとも１つの支持部が、対象物に対して配置された状態で対象物の表面上に基づく少なくとも１つのガイドローラーを含むことも可能である。少なくとも１つの支持体は、対象物の異なる寸法に適合するように調整可能であってもよい。例えば、少なくとも１つの支持体は、互いに間隔をあけて配置され、予荷重に対抗して押し広げることができる少なくとも２つの支持部分を含んでもよい。予荷重は、例えば、予荷重バネによって与えられてもよい。少なくとも１つの支持体は、対象物の異なる寸法に手動で適合させることができる。しかし、例えば電気駆動も考えられる。予荷重ばねによる予荷重の代わりに、例えば外向きの歯を持つ弾力性のある歯付きベルトのような別の設計も考えられる。この点で特に実用的な設計では、例えば、対象物の異なる寸法に適合させるために適合させることができ、例えば、対象物の外側の面に配置することができるような、２つの支持部を含んでもよく、同様に、対象物の内側の面に接するように反対側に配置された支持部を含んでもよい。
【0024】
また、少なくとも１つのセンサを設けてもよく、このセンサによって、ホルダを備えた測定装置を、対象物に接触させることなく測定プロセスに適応させることができる。少なくとも１つのセンサは、例えば、少なくとも１つの光学センサおよび／または少なくとも１つの慣性センサおよび／または少なくとも１つの位置センサを含んでもよい。この場合、測定装置は、例えば、３つまたは４つの距離センサ、例えば、飛行時間センサを用いた光学的方位測定を使用して、機械的ガイダンスなしに適応させてもよい。測定そのものにとって、例えばトランシーバから対象物の表面までの距離はあまり重要ではない。しかし、できるだけ垂直な方向、つまり測定面に対して９０°の方向は重要である。光学センサを用いた方位測定は、例えば、レチクルなどのシンボルがディスプレイなどに表示され、手動で測定がトリガーされるか、または自動認識され、例えば垂直な方位測定が達成されたときに自動的に測定がトリガーされてもよい。ジャイロセンサを使用した方位測定や、トランシーバ自体を使用した方位測定も考えられる。また、例えば対応する慣性センサや位置センサによって最適な方位測定が検出された場合に、送信装置が方位測定手順中にできるだけ早い段階で送信し、受信装置によって受信された対応する測定値を使用することも可能である。位置センサを使用する場合、例えば、管状対象物の円周上の異なる位置に、測定値を割り当てることも可能である。
【0025】
さらなる実施形態によれば、反射器は円筒部分の形状を有してもよい。これにより、特に円筒形状が管状対象物の形状、特に管状対象物の中心軸に沿った曲率に調節されている場合に、測定装置のガイダンスを簡素化することができる。特に、ホルダ上の反射器の取り外し可能な配置と組み合わせて、異なる形状の反射器、例えば異なる円筒半径の反射器は、特に異なるサイズの対象物に適合させて使用することができる。このようにして、例えば非常に小さなパイプの幾何学的パラメータも確実に測定することもできる。
【0026】
測定装置の用途に応じて、反射器は、例えば、対象物の端部の壁厚を測定するために使用することも、同じ対象物のさらなる測定における材料の屈折率を検出するためだけに使用することもできる。さらなる実施形態によれば、反射器は、送信装置によって放射されたテラヘルツ放射に対して部分的に透過させてもよい。この場合、送信装置によって放射されたテラヘルツ放射の一部は反射器によって反射され、一部は反射器を通過する。１００％反射する反射器は、光学分野では積分球として知られている。送信された高周波の最適な反射のためには、上記反射器は、その中心点がトランシーバの送信／受信アンテナの領域に位置するような形状であることが望ましい。これは、本発明による反射器にも当てはまる。反射器の曲率を例えばパイプの中心点に合わせることは、トランシーバのアンテナもパイプの中心点に合わせる場合にのみ最適である。部分的に反射する反射器は、特に、トランシーバと反射器の間に位置する対象物の壁や、管状対象物内に反射器が配置されている場合にトランシーバに背を向けて反射器の側面に配置された壁を測定する場合に有用である。部分的に透過させる反射器を使用することで、対象物の材料の屈折率を測定することができ、また、管状対象物の両壁部の壁厚を測定し、同時に外径と内径を測定することができる。また、２つの反射部分を互いに対称に配置した２分割設計の反射器も考えられる。
【0027】
送信装置から放射されたテラヘルツ放射の一部が反射器に当たって反射し、テラヘルツ放射の一部が反射器を通過するように、反射器を狭く設計することも可能である。この場合、屈折率を測定することも可能であり、テラヘルツ放射のすべてを反射する反射器の場合には、壁の厚さ、内径および外径を測定することも可能である。反射器は、十分な信号が壁厚にもかかわらず反射器からトランシーバに戻ることができ、パイプの第２の壁厚を調べるために十分な量の放射線を通過させることができ、パイプの内径と外径と同様に両方の壁厚を測定することができるように、対応する狭い輪郭を持つように設計することが特に有利である。携帯型測定装置では、装置が小型で扱いやすく、寸法も小さいことが実用上重要である。これは、対応する幅の狭い反射器で実現できる。
【0028】
さらなる実施形態によれば、ホルダは柔軟性を有してもよい。例えば、ホルダが湾曲するように設計されていれば、異なるサイズの対象物に適合させることができる。ホルダの材料として考えられるのは、原則としてプラスチック材料または金属である。ガラス繊維強化プラスチックまたは炭素繊維強化プラスチックも使用できる。柔軟なホルダは、特にプラスチック材料で構成されてもよい。
【0029】
測定装置は、対象物を製造する製造装置上に配置できる、あるいは代わりに固定した方法で配置する保持具で、トランシーバおよび／またはホルダを固定できる、あるいは代わりに取り外し可能な方法で固定する保持具を含んでもよい。例えば、保持部は、製造装置を収容する製造領域の床面に載置可能なベースプレート含んでもよい。ベースプレートは、例えばねじ接続等を介して床に固定可能であってもよい。保持部は、スタンドを形成し、位置的に正確な配置や、場合によっては測定対象物の円周周囲における測定装置のガイダンスを保証してもよい。このようにして、例えば管状対象物の円周および／または外径および／または内径および／または楕円率を介して、例えば壁厚を特に正確に検出することができる。製造装置は、対象物が押出によって製造される押出装置を含んでもよい。
【0030】
本発明による測定装置は、受信装置によって受信された測定値に基づいて、対象物の幾何学的パラメータ、特に壁厚および／または内径および／または外径を決定するように設計された評価装置をさらに含んでもよい。前述したように、対応する幾何学的パラメータを、例えば遅延時間の測定値に基づいて決定してもよい。評価装置は、トランシーバに内蔵されていてもよいし、それとは別体であってもよい。トランシーバはまた、記録された測定値および検出した屈折率の表示装置を含んでいてもよい。その結果、測定者は対応する値を迅速かつ容易に読み取ることができる。評価装置がトランシーバと別体の場合、評価装置は、例えばトランシーバ用の充電ステーションを含んでもよい。トランシーバは、ネットワークまたは例えばＬＡＮインターフェースなどのインターネットインターフェースを搭載してもよい。また、トランシーバがＰｏｗｅｒ－ｏｖｅｒ－Ｅｔｈｅｒｎｅｔ（ＰｏＥ）接続により自律的に動作することも可能である。ホルダが、別々に配置された評価装置とまたはさらなる測定装置とのＬＡＮ接続、および／または、例えば測定装置のバッテリーの充電装置と組み合わせた、トランシーバへの電圧供給を搭載することも可能である。説明したように、供給電圧は、連合しているＰｏＥ接続を介して行われてもよい。例えば、トランシーバは、その測定データを、中央評価ユニットまたは例えば押出ライン上に固定的に配置された別の測定装置に送信してもよい。このように、例えば押出ラインのウォームゾーン内、すなわち押出機から短い距離に配置された測定装置があってもよい。説明したように、このウォームゾーン内では、対象物はまだ固体化していない状態である。
【0031】
評価装置は、送信装置によって放射され受信装置によって受信されたテラヘルツ放射の、上記放射が対象物を通過した状態での遅延時間と、対象物を通過していない状態での遅延時間との比較から、対象物の屈折率を決定するように、さらに設計されてもよい。このような屈折率の決定は、例えば、国際公開第２０１６／１３９１５５号（特許文献３）で説明されており、本実施例において使用することができる。
【0032】
測定装置は、受信装置によって受信した測定値を、測定装置とは別の評価装置に送信する、および／または、測定装置に内蔵された評価装置によって評価されたデータを測定装置とは別の制御装置に送信する、無線送信装置をさらに含んでもよい。測定装置は、例えば、ＷＬＡＮデータ伝送を備えていてもよい。使用時間の間、測定装置またはむしろトランシーバは、例えば、測定装置またはむしろトランシーバのバッテリーを充電するための充電ステーションに配置してもよい。充電ステーションは、例えば有線または無線のデータ接続を介して、制御装置またはさらなる測定装置に、任意に接続してもよい。このようにして、対応する文書化を行うことができる。さらに、測定装置から受信した測定値は、例えば対象物の製造ラインの、例えば押出装置を有する押出ラインの、制御に使用することができる。測定値はまた、特に対象物の予想される収縮、あるいは代わりに予想されるたるみを考慮して、例えば対象物の幾何学的パラメータを決定するための固定テラヘルツ測定装置の測定値をチェックするために、または修正するために使用してもよい。
【0033】
評価装置は、測定装置に特別に割り当てられた評価装置であってもよい。しかしながら、評価装置が、例えば測定結果に基づいた押出装置の作動および／または主要評価装置が、さらなる測定装置に割り当てられ、測定装置の測定結果および／またはさらなる測定装置の結果を獲得し、および／または、測定装置の測定結果に基づいた収縮値および／またはたるみを修正し、および／または例えば押出機を制御するためのさらなる測定装置の測定結果を獲得するような、さらなるタスクを実行する主要評価装置となることも可能である。
【0034】
原理的には、本発明による測定装置は、対象物を検出し、その結果を可視化できるまたは可聴化できる信号として、あるいは代わりに、対象物、寸法等を検出して表すのに、必要なすべての機能を含んでいてもよいし、その結果をディスプレイに表示してもよい。評価装置は、厳密には必要ではないが、例えば、測定値を記録、文書化、または使用するため、あるいは、例えば、パイプまたはプレートの製造におけるプロセスを最適化するために、有利に使用することができる。
【0035】
本発明はまた、対象物と同様に本発明による測定装置を含むシステムに関する。このシステムは、測定装置の測定領域を通って対象物を長手方向に搬送するための搬送装置をさらに含んでいてもよい。本発明によるシステムはまた、対象物を製造するための製造装置、例えば押出装置を含んでいてもよい。
【0036】
本発明はさらに、本発明による測定装置を用いて、または本発明によるシステムを用いて、平板状またはストランド状、特に管状の、対象物の幾何学的パラメータ、特に内径、外径および／または壁厚を測定する方法によって目的を達成する。前述したように、本発明によれば、測定値は例えば対象物の製造ライン上の異なる位置で記録されてもよく、上記製造ラインとは、例えば押出ラインである。本発明によれば、対象物が既にその最終形状に到達している領域、すなわち特に完全に冷却されたまたはむしろ固化した領域は別として、例えば押出装置で製造された対象物が必要な長さに切断された後またはその直前、すなわち対象物がまだ流動可能な成分を有し、収縮および／またはたるみがまだ完了していないときに、特に製造ラインのウォームゾーン内で測定することも可能である。これについては前述したとおりである。上述した可能な実施形態を有する測定装置の持ち運び可能な設計のおかげで、屈折率が既知であると推定されない場合にも、迅速に利用可能な結果を伴う信頼性の高い測定が可能である。
【0037】
図中、特に断りのない限り、同じ参照符号は同じものを指している。
【図面の簡単な説明】
【0038】
【図1】第１の例示的実施形態による本発明による測定装置を代表図で示す、
【発明を実施するための形態】
【0039】
特に明記しない限り、同一の参照番号は、図中の同一の対象を示す。
【0040】
図１および図２に示す本発明による測定装置は、テラヘルツ放射を放射するための送信装置と、送信装置によって放射されたテラヘルツ放射を受信するための受信装置を有するトランシーバ１０を備える。図示の例では、トランシーバ１０は、Ｃ字形状のホルダ１４の脚部１２上に配置され、その脚部１２の反対側の自由端には、反射器１６が配置され、この反射器は、好ましくは、送信装置によって放射されるテラヘルツ放射に対して部分的に透過であり、テラヘルツ放射の一部をトランシーバ１０、ひいては受信装置に反射して戻し、テラヘルツ放射の一部を通過させるようになっている。ホルダ１４はさらに、２つの外側ガイドローラー１８と１つの内側ガイドローラー２０とを含む。図２には外側ガイドローラー１８は示されていない。外側ガイドローラー１８は、それぞれの場合に、保持アーム２２の外側端部に配置されている。保持アーム２２はＶ字形状を成し、例えば予荷重ばねによる予荷重に抗してガイドローラー１８によって押し広げることができる。図１および図２に示すように、測定装置は、例えば、外側ガイドローラー１８がプラスチックパイプ２４の外側の面に、内側ガイドローラー２０がプラスチックパイプ２４の内側の面上に載るように、管状対象物２４、特にプラスチックパイプ２４に対向して配置してもよい。ガイドローラー１８を押し広げることができるため、同じく異なるパイプ寸法にも対応することができる。さらに、特に図２に見られるように、ホルダ１４は、測定装置を配置するために管状対象物２４の端面に対向して配置することができるストップを形成する。トランシーバ１０は、ホルダ１４、特に脚部１２に、特に管状対象物２４の長手方向、すなわち図２における水平方向に変位可能な方法で、取り付けてもよい。反射器１６も、必要に応じて、長手方向に変位可能な方法で、ホルダ１４に取り付けてもよい。このようにして、測定装置の、特にトランシーバ１０と反射器１６の、測定管状対象物２４に関する、規定された向きと位置が保証される。測定装置は、評価装置２６をさらに備えてもよく、この評価装置２６は、例えば無線データ接続を介してトランシーバ１０に接続されていてもよい。
【0041】
動作中、トランシーバ１０の送信装置は、図２に破線２８で示すように、テラヘルツ放射を測定対象の管状対象物２４、すなわち図１および図２において垂直下方に放射する。テラヘルツ放射は、管状対象物２４の境界面、特に壁部の外面および内面、並びに反射器１６上で完全にまたは部分的に反射される。反射された後、テラヘルツ放射はトランシーバ１０に戻り、受信装置によって測定信号として検出される。測定値を得る評価装置２６は、遅延時間の測定値を用いて、例えば管状対象物２４の壁部の光学的厚さ、ひいては管状対象物２４の外径および内径を決定することができる。ここから対応する幾何学的パラメータの幾何学的値を決定するためには、管状対象物２４の材料の屈折率を考慮しなければならない。この目的のために、評価装置２６は、反射器１６によって反射されたテラヘルツ放射を各場合に用いることで、送信装置によって放射され管状対象物２４を通過した上記放射が受信装置によって受信されたテラヘルツ放射と、送信装置によって放射され管状対象物２４を通過していない上記放射が受信装置によって受信されたテラヘルツ放射との、遅延時間の比較から、管状対象物２４の屈折率を決定することができる。図１および図２に示す測定装置は、反射器１６がプラスチック管２４の内部に配置されるように設計されているため、測定は、プラスチック管２４の端面、特に、例えば押出ライン内で製造された後に必要な長さに合わせて切断された後から、適宜可能である。
【0042】
前述したように、評価装置２６はトランシーバ１０に内蔵されていてもよい。バッテリーを充電するための電源は、例えばトランシーバとは別体であってもよい。また前述したように、反射器１６は部分的に透過である必要はない。
【0043】
図３および図４は、本発明による測定装置のさらなる例示的な実施形態を示しており、この測定装置によって、まだ必要な長さに切断されていない管状対象物２４、特にプラスチック管２４を、特に押出装置から出た直後または第１の冷却タンクから出た直後のウォームゾーンにおいて、管状対象物２４がしたがってまだ流動可能な成分を有するときに、測定することもできる。この目的のために、湾曲したホルダ３０が設けられ、その一方の自由端に測定装置のトランシーバ１０が配置され、他方の自由端に反射器３２が配置され、反射器は、図示の例では、管状対象物２４の形状に適合するように円筒部分の形状を有している。ホルダ３０は、例えば、プラスチック材料からなり、柔軟性を有していてもよい。ホルダは、管状対象物２４に対して外側から配置することを可能にし、トランシーバ１０および反射器３２は、管状対象物２４の反対側の外側面に配置される。再び破線２８で示すように、トランシーバ１０の送信装置によって放射されたテラヘルツ放射は、管状対象物２４の境界面および管状対象物２４の反対側に配置された反射器３２で反射される。それぞれの場合に反射された放射線成分は受信装置に戻り、それによって測定値として受信され、その測定値は次に評価装置２６に送られる。トランシーバ１０は、測定値を表示するためのディスプレイを含んでもよい。これに基づいて、上記で説明した方法で、測定装置またはむしろ評価装置２６は、プラスチックパイプ２４の材料の屈折率、壁厚、管状対象物２４の外径と内径を決定することができる。
【0044】
前述したように、評価装置２６は、測定装置のために特別に設けられた評価装置２６であってもよい。しかしながら、上記で説明したように、評価装置２６が、例えば押出装置を作動させおよび／またはさらなる測定装置に割り当てられる中央評価装置であることも可能である。
【0045】
図５は、本発明による測定装置のさらなる例示的な実施形態を示しており、ホルダ３４に関して図３および図４による例示的な実施形態とは異なっている。上記ホルダは、２つの向かい合った脚部３６、３８を有する図１および図２のホルダ１４と同様に設計されている。トランシーバ１０は脚部３６上に配置され、反射器３２は脚部３８上に配置され、図３および図４に示す反射器３２のような曲率を有していてもよい。図５に示す例示的な実施形態では、ホルダ３４は、脚部３６、３８上に配置されるガイドローラを有してもよく、管状物体２４に対向して固定して配置された状態で管状物体２４の対向する外面に隣接し、例えば図１、２に例示的に示されるガイドローラ１８の方法で設計されてもよい。したがって、管状対象物２４に関して、測定装置、特にトランシーバ１０および反射器３２の、規定された位置および向きが、例えば管状軸２４の中心軸４０上で確保される。また、ホルダ３４は、管状対象物２４に対する配置のためのストップを形成する。また、トランシーバ１０および／または反射器３２は、それぞれ、管状対象物の長手軸方向で長手方向に変位可能であるように、ホルダ３４上、特に脚部３６および／または３８にそれぞれ配置されてもよい。
【0046】
図６に示す測定装置が図５に示す測定装置と異なるのは、例えば管状対象物２４を押し出す押出装置上に固定的に配置される保持部４２も設けられている点である。保持部４２は、ベースプレート４４からなり、このベースプレート４４は、例えば押出装置を収容する製造エリアの床面に、例えばねじ止めにより固定される。ホルダ３４は、クロスメンバー４６を介して保持部４２上に配置されてもよい。このようにして、測定装置の位置的に正確な配置と、例えば中心軸４０を中心とする回転中の測定装置の確実なガイドが、測定中に確保される。
【0047】
本発明は、管状の対象物２４、特にプラスチックパイプ２４についての例示的な実施形態に基づいて説明されてきたが、他の対象物、例えば平坦な対象物や中が詰まった円筒形の対象物についても、対応する方法で使用することができることを理解されたい。また、図１および図２に示した、細いロッド状の反射器１６の代わりに、例えば円筒部分の形状を有するパイプ形状に適合した反射器を使用することも可能である。したがって、図３～図５による例示的な実施形態では、異なる形状の反射器３２も可能であろう。
【0048】
すべての例示的な実施形態において、トランシーバ１０および／または反射器１６、３２をホルダ１４、３０、または代わりに３４に取り外し可能に配置することも可能である。これにより、反射器を使用しない測定や、例えばバッテリーを充電するためにトランシーバ１０を取り外すことや、データ送信が可能になる。例えば、図１および図２による例示的な実施形態において反射器１６を取り外すことにより、プラスチックパイプ２４の材料の屈折率が既知であれば、まだ長さに合わせて切断されていない、または代わりに平面対象物上のプラスチックパイプ２４の領域における測定が可能になる。図６に示す保持部は、図１～図４による例示的な実施形態においても設けることができる。
【符号の説明】
【0049】
１０ トランシーバ
１２ 脚部
１４ ホルダ
１６ 反射器
１８ 外部ガイドローラー
２０ 内部ガイドローラー
２２ 保持アーム
２４ 管状対象物
２６ 評価装置
２８ 破線
３０ ホルダ
３２ 反射器
３４ ホルダ
３６ 脚部
３８ 脚部
４０ 中心軸
４２ 保持部
４４ ベースプレート
４６ クロスメンバー
１２ 脚部
１４ ホルダ
１６ 反射器
１８ 外部ガイドローラー
２０ 内部ガイドローラー
２２ 保持アーム
２４ 管状対象物
２６ 評価装置
２８ 破線
３０ ホルダ
３２ 反射器
３４ ホルダ
３６ 脚部
３８ 脚部
４０ 中心軸
４２ 保持部
４４ ベースプレート
４６ クロスメンバー
【図1】
【図2】
【図3】
【図4】
【図5】
【図6】
【手続補正書】
【提出日】2024-05-01
【手続補正1】
【補正対象書類名】特許請求の範囲
【補正対象項目名】全文
【補正方法】変更
【補正の内容】
【特許請求の範囲】
【請求項1】
平板状またはストランド状、特に管状の対象物（２４）の幾何学的パラメータ、特に内径および／または外径および／または壁厚を測定するための測定装置であって、テラヘルツ放射が前記対象物（２４）によって少なくとも部分的に反射されるように、前記対象物にテラヘルツ放射を放射するための送信装置を有するトランシーバ（１０）と、前記送信装置によって前記対象物（２４）に放射された前記テラヘルツ放射を受信するための受信装置とを備え、前記測定装置は、測定者にとって持ち運び可能である、測定装置であって、
前記測定装置は、前記トランシーバ（１０）と、前記テラヘルツ放射が前記対象物（２４）の少なくとも一部分を通過した後に、前記送信装置によって放射された前記テラヘルツ放射を反射するための反射器（１６、３２）とを支持するホルダ（１４，３０，３４）備え、前記ホルダ（１４、３０、３４）は、前記対象物（２４）の前記幾何学的パラメータを測定するための前記測定装置が、前記トランシーバ（１０）と前記反射器（１６、３２）とが前記対象物（２４）または前記対象物（２４）の壁上の異なる側で互いに対向するように、前記対象物（２４）に対して配置されるように設計されていることを特徴とする、測定装置。
前記測定装置は、前記トランシーバ（１０）と、前記テラヘルツ放射が前記対象物（２４）の少なくとも一部分を通過した後に、前記送信装置によって放射された前記テラヘルツ放射を反射するための反射器（１６、３２）とを支持するホルダ（１４，３０，３４）備え、前記ホルダ（１４、３０、３４）は、前記対象物（２４）の前記幾何学的パラメータを測定するための前記測定装置が、前記トランシーバ（１０）と前記反射器（１６、３２）とが前記対象物（２４）または前記対象物（２４）の壁上の異なる側で互いに対向するように、前記対象物（２４）に対して配置されるように設計されていることを特徴とする、測定装置。
【請求項2】
前記ホルダ（１４，３０，３４）がＣ字形であることを特徴とする請求項１に記載の測定装置。
【請求項3】
前記ホルダ（１４，３０，３４）は、前記測定装置を配置するために前記対象物（２４）の端面に対向して配置可能なストップを形成することを特徴とする、請求項１または２のいずれかに１項に記載の測定装置。
【請求項4】
前記トランシーバ（１０）および／または前記反射器（１６，３２）が、前記ホルダ（１４，３０，３４）上に長手方向に変位可能な方法で取り付けられていることを特徴とする、請求項１または２のいずれか１項に記載の測定装置。
【請求項5】
前記トランシーバ（１０）および／または前記反射器（１６，３２）が、前記ホルダ（１４，３０，３４）上に着脱可能に配置されていることを特徴とする、請求項１または２のいずれか１項に記載の測定装置。
【請求項6】
前記反射器（１６、３２）は、前記測定装置が前記対象物（２４）と対向して配置された状態で前記テラヘルツ放射が通過し、前記反射器（１６，３２）に隣接する前記対象物（２４）の壁から離れて配置されていることを特徴とする、請求項１または２のいずれか１項に記載の測定装置。
【請求項7】
前記ホルダ（１４，３０，３４）は、前記トランシーバ（１０）および／または前記反射器（１６，３２）が前記対象物（２４）に対向して配置された状態で前記対象物（２４）の表面上に載る少なくとも１つの支持体を備えることを特徴とする、請求項１または２のいずれか１項に記載の測定装置。
【請求項8】
前記少なくとも１つの支持体は、前記対象物（２４）に対して配置された状態で前記対象物（２４）の前記表面上に載る少なくとも１つのガイドローラ（１８、２０）を備えることを特徴とする、請求項７に記載の測定装置。
【請求項9】
前記少なくとも１つの支持体は、前記対象物（２４）の異なる寸法に適合するように調整可能であることを特徴とする、請求項７に記載の測定装置。
【請求項10】
前記少なくとも１つの支持体は、互いに間隔を隔てて配置され予荷重に対抗して押し広げ可能な少なくとも２つの支持部を備えることを特徴とする、請求項９に記載の測定装置。
【請求項11】
前記ホルダ（１４，３０，３４）を備えた前記測定装置を、前記対象物（２４）に接触させることなく測定の過程で方向付けることによって、少なくとも１つのセンサも設けられていることを特徴とする、請求項１または２のいずれか１項に記載の測定装置。
【請求項12】
前記少なくとも１つのセンサは、少なくとも１つの光学センサおよび／または少なくとも１つの慣性センサおよび／または少なくとも１つの位置センサを備えることを特徴とする、請求項１１に記載の測定装置。
【請求項13】
反射器（１６、３２）が円筒部の形状を有することを特徴とする、請求項１または２のいずれか１項に記載の測定装置。
【請求項14】
前記反射器（１６，３２）は、前記送信装置によって放射される前記テラヘルツ放射に対して部分的に透過であることを特徴とする、請求項１または２のいずれか１項に記載の測定装置。
【請求項15】
前記対象物を製造するための製造装置上に固定的に配置することができ、前記トランシーバ（１０）および／または前記ホルダ（１４，３０，３４）を着脱可能に固定することができる保持部（４２）をさらに備えることを特徴とする、請求項１または２のいずれか１項に記載の測定装置。
【請求項16】
前記受信装置によって受信された測定値に基づいて、前記対象物（２４）の幾何学的パラメータ、特に壁厚および／または内径および／または外径を決定するように設計された評価装置（２６）をさらに備えることを特徴とする、請求項１または２のいずれか１項に記載の測定装置。
【請求項17】
前記評価装置（２６）は、放射が前記対象物（２４）を通過した状態で前記送信装置によって放射され前記受信装置によって受信された前記テラヘルツ放射の遅延時間と、前記放射が前記対象物（２４）を通過していない状態で前記送信装置によって放射され前記受信装置によって受信されたテラヘルツ放射の遅延時間との比較から、前記対象物（２４）の屈折率を決定するようにさらに設計されていることを特徴とする、請求項１６に記載の測定装置。
【請求項18】
前記測定装置は、前記受信装置によって受信された測定値を前記測定装置とは別の評価装置（２６）に送信するための、および／または、前記測定装置に内蔵されている評価装置（２６）によって評価されたデータを前記測定装置とは別の制御装置に送信するための、無線送信装置を備えることを特徴とする、請求項１または２のいずれか１項に記載の測定装置。
【請求項19】
請求項１または２のいずれか一項に記載の測定装置と、前記対象物（２４）とを備える、システム。
【請求項20】
前記測定装置の測定領域を通って前記対象物（２４）を長手方向に搬送する搬送装置をさらに備えることを特徴とする、請求項１９に記載のシステム。
【請求項21】
請求項１または２のいずれか１項に記載の測定装置を用いて、平板状またはストランド状、特に管状の対象物（２４）の幾何学的パラメータ、特に内径および／または外径および／または壁厚を測定する、方法。
【請求項22】
請求項１９に記載のシステムを用いて、平板状またはストランド状、特に管状の対象物（２４）の幾何学的パラメータ、特に内径および／または外径および／または壁厚を測定する、方法。
【外国語明細書】
Measuring device and method for measuring a geometric parameter of an object
The invention relates to a measuring device for measuring a geometric parameter, in particular an inner and/or outer diameter and/or a wall thickness, of a flat or strand-shaped, in particular tubular, object, comprising a transceiver having a transmission apparatus for emitting terahertz radiation onto the object, wherein the terahertz radiation is at least partially reflected by the object, and having a receiving apparatus for receiving the terahertz radiation emitted by the transmission apparatus onto the object, wherein the measuring device is a measuring device that is portable for an operator.
The invention also relates to a method for measuring a geometric parameter, in particular an inner and/or outer diameter and/or a wall thickness of a flat or strand-shaped, in particular tubular, object.
In the manufacture of plastics pipes in extrusion lines, for example, it is desirable to be able to measure geometric parameters, for example wall thicknesses and inner or outer diameters in a flexible manner, at an early stage, and at various locations on the production line. For this purpose, terahertz measuring devices are known from the prior art which emit terahertz radiation onto the object and receive terahertz radiation reflected by the object. For example, geometric parameters such as wall thicknesses or diameters can be determined based on delay time measurements.
For fast and flexible measurement of geometric parameters at different locations on a production line, hand-held devices that can be carried by an operator are helpful. A portable device is known from DE 10 2016 119 728 A1. It comprises a support contour having multiple contact points for positioning the device on the object to be measured. The known portable device can be used, for example, to determine the geometric wall thickness if the refractive index of the material of the object is assumed to be known.
For frequently used plastics materials, such as PE, PP, HDPE, PVDF, PTFE, PVC, etc., in pure form, reliable refractive index values are known for standard conditions. In principle, the refractive index depends on the temperature of the material, on the state of aggregation thereof, and thus on the density thereof, but also on the frequency used. However, in practice, additives are often added to the plastics materials, for example for better protection against UV radiation or to achieve anti-static properties. Additives alter the refractive index and the addition of additives is often subject to fluctuations on account of irregular admixtures or fluctuating proportions of the additives in the supplied plastics materials. The requirements for measuring geometric parameters of pipes of this kind are established in the standard DIN EN ISO 3126. The required level of measuring accuracy is demanding. A change in the refractive index due to added additives can significantly distort a wall thickness measurement with the known portable device if the refractive index is assumed to be constant. Therefore, for reliable measured values for the wall thickness of a plastics material, it is urgently advised to detect the refractive index directly at the measurement location for a wall thickness in order to use same in the calculation of the geometric wall thickness.
In order to determine the refractive index or rather to calibrate a first terahertz measuring apparatus with regard to the refractive index, DE 10 2022 100 650 B3 proposes performing a wall thickness measurement on an already cooled pipe piece using a mechanical tactile measuring apparatus, by means of which a second terahertz measuring device that measures the cooled pipe piece is calibrated. This can in turn be used to calibrate the first terahertz measuring apparatus. In this way, the individual refractive index of the object to be measured can be determined at the measurement location and accurate geometric parameters can thus be determined. However, the calibration procedure is very time-consuming due to the delay time between the first measurement and the final measurements on the cooled pipe being one or more hours. Finally, this method merely provides a value for the refractive index at the first measurement location, i.e. in the so-called hot zone, in which the plastics material has only partially solidified. Aside from the proportion of additives in the plastics material, the temperature thereof, the density, and the state of aggregation of the material also have an influence on the refractive index value.
Proceeding from the explained prior art, the object of the invention is to provide a measuring device and a method of the type mentioned at the outset, by means of which geometric parameters can be determined in a flexible and reliable manner at different locations on the object.
The invention achieves the object through independent claims 1 and 21. Advantageous embodiments are disclosed in the dependent claims, the description, and the figures.
With regard to a measuring device of the type mentioned at the outset, the invention achieves the object in that the measuring device comprises a holder that supports the transceiver as well as a reflector for reflecting the terahertz radiation emitted by the transmission apparatus after said terahertz radiation has passed through at least one portion of the object, wherein the holder is designed such that the measuring device for measuring the geometric parameter of the object can be placed against the object such that the transceiver and the reflector are opposite one another on different sides of the object or a wall of the object.
The object to be measured may, for example, be cylindrical or tubular. It may also be a flat or rather planar object. It is at least partially transparent to the terahertz radiation emitted by the transmission apparatus, such that terahertz radiation emitted onto the object is reflected on boundary surfaces of the object. Some of the terahertz radiation can pass through the object and, after being reflected on the reflector, return to the receiving apparatus, where said radiation and the radiation components reflected by the object are received as measurement signals. The transmission apparatus and the receiving apparatus are designed to be integrated into a transceiver and are, in particular, located at the same location. The object may consist of a plastics material, for example PE, PP, HDPE, PTFE, PVDF, or PVC. However, the object may also consist, for example, of glass or ceramic material or frozen water or wood or construction materials of various types, provided that it is at least partially transparent to the terahertz radiation used. The terahertz radiation may, for example, emit radiation in a frequency range of from 1 GHz to 6 THz, in particular in a frequency range of from 10 GHz to 1.5 THz. The object may be conveyed in a longitudinal direction through a measuring region of the measuring device. For example, the object may have been manufactured in an extrusion device and, for example, be measured by means of the measuring device according to the invention or, alternatively, method according to the invention while still in the extrusion line. The object may still comprise flowable components, i.e. not be completely cooled or rather solidified, at the time of the measurement with the measuring device according to the invention or, alternatively, method according to the invention. This applies, in particular, to a measurement shortly after exit from the extrusion device or a first cooling tank of the extrusion line. The transmission apparatus may emit FMCW terahertz radiation, in particular broadband terahertz radiation.
As already explained, the receiving apparatus receives the terahertz radiation emitted by the transmission apparatus and at least partially reflected by the object. As already explained as well, the receiving apparatus may also receive terahertz radiation that has passed through the object. The measuring device according to the invention is portable for an operator, in particular during the measurement. It is therefore a hand-held device. The measuring device preferably has its own energy supply for electrical energy, in particular a battery, preferably a rechargeable battery. As is known per se, the receiving apparatus may, for example, determine geometric parameters of the object, for example a wall thickness and/or an inner and/or outer diameter, based on delay time measurements of the terahertz radiation reflected at different boundary layers of the object and display the results on a display. For this purpose, the measuring device may comprise a corresponding evaluation apparatus, as will be explained in more detail below.
According to the invention, the measuring device comprises a holder which supports the transceiver as well as a reflector for reflecting the terahertz radiation emitted by the transmission apparatus after said radiation has passed through at least one portion of the object. The holder is designed such that the measuring device can be placed against an object for a measurement process in such a way that the transceiver and the reflector are opposite one another on different sides of the object or on different sides of a wall of the object. Terahertz radiation emitted by the transmission apparatus is thus reflected by the reflector after having passed through the object or the wall of the object, such that, after passing through the object or the wall of the object again, the terahertz radiation returns to the transceiver, in particular the receiving apparatus, where said radiation is detected as a measurement signal. As will be explained in more detail below, it is thus possible to determine the individual refractive index of the material of the object just measured at the same location and thus also to determine reliable and precise measured values of the relevant geometric parameter in the event of a changing composition of the object or even in the event of a composition that is not known with sufficient accuracy, for example due to the addition of additives. At the same time, due to the design of the portable measuring device with the holder, a measurement can be performed by an operator at largely arbitrary locations on the object or rather on a production line for the object. The measurement results are reliable and available quickly. Although measuring devices arranged in a stationary manner can potentially deliver measurement results continuously, the portable measuring device according to the invention can achieve a reliable measurement result in a very flexible manner. On account of the design according to the invention with the holder as well as the transceiver and reflector, the refractive index and measurement results of the geometric parameter based thereon can be obtained in one measuring step. Reliable documentation for acceptance of the object within the context of a production line is thus also possible.
In contrast to the hand-held device of the prior art explained at the outset, the measuring device according to the invention does not rely on presuming the refractive index of the object to be known. Rather, the precise value of the refractive index of the object is recorded directly at the measurement location itself and included in the calculation of the measured values for the geometric parameter. As a result, the requirements imposed by the standard DIN EN ISO 3126 are fully met.
Provided that the transceiver and the reflector are opposite one another on different sides of a wall of the object in the state placed against the object, the measuring device can, for example, be placed at the end of a tubular object, for example subsequently to production, i.e. immediately before and also after the tubular object is cut to length. The reflector or the transceiver is then arranged inside the tubular object, while the other of the two is arranged opposite on the outer face of the tubular object. According to the invention, in addition to wall thicknesses and diameters, ovalities of a tubular object, for example, can also be reliably determined as geometric parameters during production or subsequently to production by measuring, for example, the inner or outer diameter multiple times over the circumference of the object. For this purpose, the measuring device can be rotated as a whole or, for example, only the transceiver can be rotated about a longitudinal axis, for example, of a tubular object while the reflector remains still. For the rotation, the measuring device may comprise a rotary drive. By measuring around the circumference of the object, in addition to wall thickness fluctuations, it is possible, for example, to identify inhomogeneities in the material of the object, for example an inhomogeneous distribution of additives around the circumference of the object. The measuring device could also detect an absorption of the terahertz radiation caused by the object, for example by comparing the terahertz radiation emitted and then recovered after being reflected on the reflector. In this way, the portable measuring device is also well suited for checking whether the object or rather a material of the object can be measured in the manner according to the invention and, if applicable, to what thickness.
In principle, the portable device should be suitable for measuring small and large objects and, if applicable, also at short distances from the surface of the object. The antenna of the transceiver should thus have a high gain of preferably 20 to 30 dBi and a sensitivity that is sufficient with the accompanying amplitudes. In order to prevent overmodulation of the reception signal, closed-loop control of the transmission power that allows for adaptation to the relevant situation of the reception signals can be useful. Sufficiently fast control is useful, for example, in order to be able to perform a measuring process at a different transmission power, adapted to a front and rear wall thickness of a pipe, for example.
According to a particularly practical embodiment, the holder may be C-shaped. The transceiver and the reflector may then be arranged at the opposite free ends of the C-shaped holder. A C-shaped holder of this kind may, for example, consist of plastics material, for example a carbon fiber-reinforced plastics material. Provided that a C-shaped or curved holder of the measuring device is sufficiently large, the transceiver and the reflector can, for example, be positioned on opposing outer faces of the object during measurement of a tubular object.
The holder may form a stop which can be placed against an end face of the object for placement of the measuring device. In this way, a defined position of the measuring device relative to the object, in particular an end face of a flat object or a pipe that has already been cut to length, is made available. For example, when measuring the wall thickness of pipes, a particular distance from the cut edge of the pipe, for example at least 50 mm, is often prescribed. Due to the stresses released in the material, there are often no reliable values for the wall thickness at the cut edges themselves. The prescribed distance from the cut edge can be ensured at all times with the above-mentioned design. This also applies, for example, to a measurement of the wall thickness over the circumference of the pipe.
According to a further embodiment, in order to allow for adjustability of the distance from an edge, for example a cut edge, of the object in order to adapt to different requirements or conditions, it can be provided that the transceiver and/or the reflector is mounted on the holder in a longitudinally displaceable manner, in particular in the longitudinal direction of the object in the state placed against the object.
According to a further embodiment, the transceiver and/or the reflector may be detachably arranged on the holder. In this way, a measurement with the measuring device is possible with or without the reflector as needed. A measurement without a reflector is useful, for example, if the refractive index of the material of the object is known to a sufficiently reliable extent even without a corresponding measurement. A combination of the measuring device with a reflector arranged, for example, in a stationary manner on a production line of the object, for example an extrusion line of a tubular object, is then possible as well. A stationary reflector of this kind could, for example, be arranged at the start of an extrusion line for the object, for example at the outlet of a first cooling tank in which the object undergoes a first cooling after exiting the extrusion device. If, for example, the reflector arranged in a stationary manner also has a receiving portion for the transceiver of the measuring device or the holder of the measuring device, a precise orientation would thus be ensured at all times for the measurement. Particularly simple mounting of a reflector in combination with a holder for a transceiver, for example directly at the outlet of a first cooling tank or, alternatively, upstream of the inlet into a further cooling tank or, alternatively, between further cooling tanks of the production line can thus be achieved and ensures a high degree of repeatability for the measurement path between the transceiver and the reflector. Therefore, an accurate measurement in the warm zone of the production line is possible, i.e. when the object thus still has flowable components and is thus still subject to a certain amount of shrinkage and sagging. Although measurement results that may deviate from the final geometric parameters of the fully solidified object are obtained in this warm zone, they can be an important aid when setting up the production line, in particular when presetting an extrusion device with regard to the wall thickness and the expected sagging. It is currently common practice to mechanically measure the outer dimension of the diameter of a tubular object in the warm zone using a tape measure. Here, the invention allows for simple non-contact detection using the measuring device. With knowledge of the outer diameter, for example, of a tubular object and with the measurement of the inner diameter by means of the measuring device according to the invention, the double wall thickness of the tubular object can be ascertained and individual geometric wall thickness values can be determined from the detected optical wall thickness values both at the front and at the rear. Detachment of the transceiver from the holder may also be useful, for example in order to recharge a battery of the transceiver or to change to another transceiver or the like. Even a folding design of the reflector, for example, is conceivable such that the reflector can be used while still held on the holder and either folded into the measurement path or folded out thereof.
A detachable design of the transceiver on the holder also has the advantage that the transceiver can be combined with different holders, depending on the intended use. Accordingly, the measuring device may also comprise multiple holders that are designed in the manner according to the invention and that are optimized for different purposes. The detachable arrangement of the reflector on the holder also allows for simple yet precise and user-friendly locking of the reflector. In order to precisely determine the geometric dimensions, the wall thickness, the wall thickness and/or diameter values, exact determination of the refractive index is important, namely the detection of the delay time differences between direct irradiation of the reflector and irradiation thereof after radiation has passed through materials, which increases the delay time. This means that no changes in distance in the range of a few micrometers can take place between calibration of the distance of the reflector and practical use thereof. In the case of a refractive index of typically 1.5 for plastics materials and approximately 2 for glass, this means that approximately one third of any change in distance of the reflector is included in the wall thickness value in the case of plastics materials, and one half in the case of glass. Thus, a precise arrangement of the transceiver and reflector is particularly important.
According to a further embodiment, the reflector may be spaced apart from a wall of the object that is adjacent to the reflector and through which the terahertz radiation passes in the state of the measuring device placed against the object. There is therefore a certain distance between the reflector and the portion of the object to be measured, for example the wall of the object. In this way, echoes of the reflector and of the spaced-apart surface, for example an inner wall of a tubular object, can be reliably separated in the measurement signal.
The holder may further comprise at least one support by means of which the transceiver and/or the reflector rests on a surface of the object in the state placed against the object. On account of a support of this kind, a defined arrangement or rather position of the transceiver and/or reflector in relation to the object to be measured is ensured. The at least one receiving portion may, for example, comprise at least one guide runner or rather skid. It is also possible, for example, for the at least one support to comprise at least one guide roller that rests on the surface of the object in the state placed against the object. The at least one support may be adjustable in order to adapt to different dimensions of the object. For example, the at least one support may comprise at least two support portions that are spaced apart from one another and that can be pressed apart counter to a preload. The preload may, for example, be provided by means of a preload spring. The at least one support can be adapted to different dimensions of the object manually. However, an electric drive, for example, is also conceivable. Instead of a preload by means of a preload spring, another design, for example, is also conceivable, for example a resilient toothed belt with outward-facing teeth. A particularly practical design in this regard may, for example, comprise two support portions that can be adapted in order to adapt to different dimensions of the object and that, for example, can be placed on an outer face of the object as well as comprise a support portion arranged on the opposite side for abutting an inner face of the object.
At least one sensor may also be provided, by means of which the measuring device with the holder can be oriented for a measurement process without contacting the object. The at least one sensor may, for example, comprise at least one optical sensor and/or at least one inertial sensor and/or at least one position sensor. In this case, the measuring device may also be oriented without mechanical guidance, for example using optical orientation with three or four distance sensors, for example time-of-flight sensors. For the measurement itself, the distance, for example from the transceiver to the surface of the object, is of little importance. However, an orientation that is as vertical as possible, i.e. 90° to the measuring plane, is important. The orientation with optical sensors may, for example, take place in that a symbol, for example a reticle, is displayed on a display or the like with manual triggering of the measurement or with automatic recognition and automated triggering of the measurement when, for example, a vertical orientation is achieved. Orientation using gyroscopic sensors or using the transceiver itself would also be conceivable. It is also possible for the transmission apparatus to transmit as early as during the orientation procedure and to use the corresponding measured values received by the receiving apparatus when an optimal orientation is detected, for example by means of corresponding inertial or position sensors. When using position sensors, it is also possible, for example, to assign the measured values to different positions on the circumference of a tubular object.
According to a further embodiment, the reflector may have the shape of a cylindrical portion. This can simplify guidance of the measuring device, in particular if the cylindrical shape is adapted to the geometry of a tubular object, in particular a curvature aligned with the center axis of a tubular object. In particular in conjunction with the detachable arrangement of the reflector on the holder, differently shaped reflectors, for example reflectors with different cylinder radii, can be used, in particular in order to adapt to differently sized objects. In this way, geometric parameters of very small pipes, for example, can also be measured reliably.
Depending on the use of the measuring device, the reflector can be used, for example, to measure the wall thickness at the edge of an object or merely to detect the refractive index of the material for further measurements of the same object. According to a further embodiment, the reflector may be partially transparent to the terahertz radiation emitted by the transmission apparatus. In this case, some of the terahertz radiation emitted by the transmission apparatus is reflected by the reflector, while some passes through the reflector. A 100% reflective reflector is known in optics as an integrating sphere. For optimal reflection of the transmitted high frequency, said reflector should be shaped such that its center point is located in the region of the transmission/reception antenna of the transceiver. This also applies to the reflector according to the invention. Alignment of the curvature of the reflector with the center point, for example, of a pipe would only be optimal if the antenna of the transceiver were also aligned with the center point of the pipe. A partially reflective reflector may be useful, in particular, if a wall of the object located between the transceiver and the reflector as well as a wall arranged on a side of the reflector facing away from the transceiver are to be measured in the case of an arrangement of the reflector inside a tubular object. Using a partially transparent reflector makes it possible to measure the refractive index of the material of the object and also the wall thickness of both wall portions of the tubular object and, at the same time, the outer and inner diameter. A two-part design of the reflector with two reflector portions arranged symmetrically with respect to one another would also be conceivable.
A narrow design of the reflector is also possible, such that some of the terahertz radiation emitted by the transmission apparatus strikes the reflector and is reflected thereby, and some of the terahertz radiation passes by the reflector. In this case, it is also possible to determine the refractive index and to measure the wall thickness and the inner and outer diameter in the case of a reflector that reflects all of the terahertz radiation. It is particularly advantageous to design the reflector such that it has a correspondingly narrow contour, such that enough signal can make it back from the reflector to the transceiver in spite of the wall thickness to travel through and such that a sufficient amount of the radiation can pass through in order to examine the second wall thickness of a pipe and thus to determine both wall thicknesses, as well as the inner and outer diameter of a pipe. For a hand-held measuring device, it is of practical importance if a device is small and handy and also has small dimensions. This can be achieved with a correspondingly narrow reflector.
According to a further embodiment, the holder may be flexible. For example, if it is designed to be curved, it can thus be adapted to different sizes of the object. Possible materials for the holder are, in principle, plastics materials or metals. Even glass fiber-reinforced or carbon fiber-reinforced plastics materials could be used. Flexible holders may consist, in particular, of plastics material.
The measuring device may further comprise a holding portion which can be arranged or, alternatively, is arranged in a stationary manner on a manufacturing apparatus for manufacturing the object and to which the transceiver and/or the holder can be fastened or, alternatively, is fastened in a detachable manner. For example, the holding portion may comprise a base plate which can rest on the floor of a production area that houses the manufacturing apparatus. The base plate may be fastenable to the floor, for example via a screw connection or the like. The holding portion may form a stand and ensures positionally precise arrangement and, if applicable, guidance of the measuring device around the circumference of the object to be measured. In this way, for example, the wall thickness can be detected in a particularly precise manner via the circumference and/or an outer and/or inner diameter and/or an ovality of a, for example, tubular object. The manufacturing apparatus may comprise an extrusion device in which the object is manufactured by means of extrusion.
The measuring device according to the invention may further comprise an evaluation apparatus which is designed to determine a geometric parameter, in particular a wall thickness and/or an inner and/or outer diameter, of the object based on measured values received by the receiving apparatus. As explained at the outset, the corresponding geometric parameters may be determined, for example, based on delay time measurements. The evaluation apparatus may be integrated in the transceiver or it may be separate therefrom. The transceiver may also comprise a display apparatus for the recorded measured values and the detected refractive index. As a result, an operator can read off the corresponding values quickly and easily. If the evaluation apparatus is separate from the transceiver, it may, for example, comprise a charging station for the transceiver. The transceiver may also be equipped with a network or Internet interface, for example a LAN interface. It is also possible for the transceiver to be operated autonomously with a Power-over-Ethernet (PoE) connection. It is also possible for the holder to be equipped with a LAN connection to a separately arranged evaluation apparatus or to a further measuring device, and/or with a voltage supply for the transceiver, for example in combination with a charging device for a battery of the measuring device. As already explained, the voltage supply may take place via a combined Power-over-Ethernet connection. For example, the transceiver may transmit its measurement data to a central evaluation unit or to another measuring apparatus that is, for example, arranged in a stationary manner on an extrusion line. This may, for example, be a measuring apparatus which is arranged in the warm zone of the extrusion line, i.e. at a short distance from the extruder. As explained, in this warm zone the object has regions that have not yet solidified.
The evaluation apparatus may further be designed to determine the refractive index of the object from a comparison of the delay time of the terahertz radiation emitted by the transmission apparatus and received by the receiving apparatus with said radiation passing through the object with the delay time of the terahertz radiation emitted by the transmission apparatus and received by the receiving apparatus without said radiation passing through the object. Such determination of the refractive index is explained, for example, in WO 2016/139155 A1 and can be used in the present case.
The measuring device may further comprise a wireless transmission apparatus for transmitting measured values received by the receiving apparatus to an evaluation apparatus that is separate from the measuring device and/or for transmitting data evaluated by an evaluation apparatus integrated in the measuring device to a control apparatus that is separate from the measuring device. The measuring device may, for example, be equipped with WLAN data transmission. Between usage times, the measuring device or rather the transceiver may, for example, be arranged in a charging station for charging a battery of the measuring device or rather the transceiver. The charging station may optionally be connected, for example via a wired or wireless data connection, to the control apparatus or to a further measuring device. In this way, corresponding documentation can take place. Moreover, the measured values received from the measuring device can be used for the control, for example, of a production line for the object, for example an extrusion line having an extrusion device. The measured values may also be used, for example, to check or even correct measured values of a stationary terahertz measuring device for determining geometric parameters of the object, in particular with a view to expected shrinkage or, alternatively, expected sagging of the object.
The evaluation apparatus may be an evaluation apparatus that is specially assigned to the measuring device. However, it is also possible for the evaluation apparatus to be a central evaluation apparatus which performs further tasks, for example actuation of an extrusion device based on the measurement results and/or said central evaluation apparatus is assigned to a further measuring apparatus and archives the measurement results of the measuring device and/or the measurement results of the further measuring apparatus and/or corrects values for shrinkage and/or sagging of the object based on the measurement results of the measuring device and/or the measurement results of the further measuring device, for example for control of an extrusion device.
In principle, the measuring device according to the invention may comprise all functions required for detecting objects and representing the result in the form of visible or audible signaling, or alternatively to detect objects, dimensions, etc., and display the results on a display. The evaluation apparatus is not strictly required, but it can advantageously be used, for example, to register, document, or use measured values or to optimize a process, e.g. in the manufacture of pipes or plates.
The invention also relates to a system comprising a measuring device according to the invention as well as the object. The system may further comprise a conveying apparatus for conveying the object in a longitudinal direction through a measuring region of the measuring device. The system according to the invention may also comprise a manufacturing apparatus, for example an extrusion device, for manufacturing the object.
The invention further achieves the object by means of a method for measuring a geometric parameter, in particular an inner and/or outer diameter and/or a wall thickness of a flat or strand-shaped, in particular tubular, object using a measuring device according to the invention or using a system according to the invention. As already explained, according to the invention, the measured values may be recorded at different positions on a production line for the object, for example, said production line being an extrusion line, for example. According to the invention, aside from regions in which the object has already attained its final geometry, i.e. in particular fully cooled or rather solidified, for example after or immediately before an object manufactured in an extrusion device has been cut to length, it is also possible to measure in the warm zone of the production line in particular, i.e. when the object still has flowable components and shrinkage and/or sagging is not yet complete. This has been explained above. On account of the portable design of the measuring device with the above-mentioned possible embodiments, a reliable measurement with quickly available results is also possible when the refractive index is not presumed to be known.
Exemplary embodiments of the invention are explained below in greater detail with reference to schematic figures, in which:
Fig. 1 shows a measuring device according to the invention according to a first exemplary embodiment in a first view,
Fig. 2 shows the measuring device from Fig. 1 in a view that has been rotated by 90° with respect to Fig. 1,
Fig. 3 shows a measuring device according to the invention according to a further exemplary embodiment in a view corresponding to Fig. 1,
Fig. 4 shows the measuring device from Fig. 3 in a view that has been rotated by 90° with respect to Fig. 3,
Fig. 5 shows a measuring device according to the invention according to a further exemplary embodiment in a view corresponding to Fig. 4, and
Fig. 6 shows a measuring device according to the invention according to a further exemplary embodiment in a view corresponding to Fig. 5.
The same reference signs refer to the same objects in the figures unless indicated otherwise.
The measuring device according to the invention shown in Fig. 1 and 2 comprises a transceiver 10 having a transmission apparatus for emitting terahertz radiation and having a receiving apparatus for receiving the terahertz radiation emitted by the transmission apparatus. In the example shown, the transceiver 10 is arranged on a leg 12 of a C-shaped holder 14, on the free end of which opposite the leg 12 a reflector 16 is arranged, which reflector is preferably partially transparent to the terahertz radiation emitted by the transmission apparatus, such that it reflects some of the terahertz radiation back to the transceiver 10 and thus to the receiving apparatus and allows some of the terahertz radiation to pass through. The holder 14 further comprises two outer guide rollers 18 and an inner guide roller 20. Fig. 2 does not show the outer guide rollers 18. The outer guide rollers 18 are in each case arranged at an outer end of a holding arm 22. The holding arms 22 form a V-shape and can be pressed apart by means of the guide rollers 18 against a preload provided, for example, by a preload spring. As shown in Fig. 1 and 2, the measuring device may, for example, be placed against a tubular object 24, in particular a plastics pipe 24, such that the outer guide rollers 18 rest on the outer face of the plastics pipe 24 and the inner guide roller 20 rests on the inner face of the plastics pipe 24. Due to the possibility of pressing the guide rollers 18 apart, same can be adapted to different pipe dimensions. Furthermore, as is visible in Fig. 2 in particular, the holder 14 forms a stop which can be placed against an end face of the tubular object 24 for placement of the measuring device. The transceiver 10 may be mounted on the holder 14, in particular the leg 12, in a longitudinally displaceable manner, in particular in the longitudinal direction of the tubular object 24, i.e. in the horizontal direction in Fig. 2. The reflector 16 may also be mounted on the holder 14 in a longitudinally displaceable manner, if desired. In this way, a defined orientation and position of the measuring device, in particular of the transceiver 10 and the reflector 16, relative to the tubular object 24 to be measured is ensured. The measuring device further comprises an evaluation apparatus 26, which may be connected to the transceiver 10 via a wireless data connection, for example.
During operation, the transmission apparatus of the transceiver 10 emits terahertz radiation onto the tubular object 24 to be measured, i.e. vertically downward in Fig. 1 and 2, as illustrated in Fig. 2 by the dashed line 28. The terahertz radiation is reflected on boundary surfaces of the tubular object 24, in particular the outer and inner faces of the wall portions, as well as completely or partially on the reflector 16. After being reflected, the terahertz radiation returns to the transceiver 10 and is detected as a measurement signal by the receiving apparatus. The evaluation apparatus 26, which obtains the measured values, can use the delay time measurements, for example, to determine the optical thickness of the wall portions of the tubular object 24 and thus the outer and inner diameter of the tubular object 24. In order to determine herefrom the geometric values of the corresponding geometric parameters, the refractive index of the material of the tubular object 24 must be taken into account. For this purpose, the evaluation apparatus 26 can determine the refractive index of the tubular object 24 from the comparison of the delay time of the terahertz radiation emitted by the transmission apparatus and received by the receiving apparatus with said radiation passing through the tubular object 24 with the delay time of the terahertz radiation emitted by the transmission apparatus and received by the receiving apparatus without said radiation passing through the tubular object 24, in each case using the terahertz radiation reflected by the reflector 16. Since the measuring device shown in Fig. 1 and 2 is designed such that the reflector 16 is arranged inside the plastics pipe 24, a measurement is accordingly possible from an end face of the plastics pipe 24, in particular after the plastics pipe 24 has been cut to length after being manufactured in an extrusion line, for example.
As explained, the evaluation apparatus 26 may be integrated in the transceiver 10. A power supply for charging a battery, for example, may be separate from the transceiver, for example. As also explained, the reflector 16 does not have to be partially transparent.
Fig. 3 and 4 show a further exemplary embodiment of a measuring device according to the invention, by means of which a tubular object 24, in particular a plastics pipe 24, that has not yet been cut to length can, in particular, also be measured, in particular in the warm zone shortly after exiting an extrusion device or after exiting a first cooling tank, when the tubular object 24 thus still has flowable components. For this purpose, a curved holder 30 is provided, at one free end of which the transceiver 10 of the measuring device is arranged and at the other free end of which a reflector 32 is arranged, which reflector, in the example shown, has the shape of a cylindrical portion in adaptation to the geometry of the tubular object 24. The holder 30 may, for example, consist of a plastics material and be flexible. The holder allows for placement against the tubular object 24 from the outside, wherein the transceiver 10 and the reflector 32 are located on opposite outer faces of the tubular object 24. As illustrated again by the dashed line 28, terahertz radiation emitted by the transmission apparatus of the transceiver 10 is reflected on boundary surfaces of the tubular object 24 and on the reflector 32 arranged on the opposite side of the tubular object 24. The radiation components reflected in each case return to the receiving apparatus and are received thereby as measured values, which are in turn sent to the evaluation apparatus 26. The transceiver 10 may also comprise a display for representing the measured values. On this basis and in the manner explained above, the measuring device or rather the evaluation apparatus 26 can determine the refractive index of the material of the the refractive index of the material of the plastics pipe 24 and the wall thicknesses as well as the outer and inner diameters of the tubular object 24.
As explained, the evaluation apparatus 26 may be an evaluation apparatus 26 that is specially provided for the measuring device. However, it is also possible for the evaluation apparatus 26 to be a central evaluation apparatus which, for example, actuates an extrusion device and/or is assigned to a further measuring apparatus, as explained above.
Fig. 5 shows a further exemplary embodiment of a measuring device according to the invention, which differs from the exemplary embodiment according to Fig. 3 and 4 with regard to the holder 34. Said holder is designed similarly to the holder 14 in Fig. 1 and 2 with two opposing legs 36, 38. The transceiver 10 is arranged on the leg 36 and the reflector 32 is arranged on the leg 38 and may have a curvature like the reflector 32 shown in Fig. 3 and 4. In the exemplary embodiment shown in Fig. 5, the holder 34 may have guide rollers which are arranged on the legs 36, 38, abut opposing outer faces of the tubular object 24 in the state placed against the tubular object 24, and may be designed, for example, in the manner of the guide rollers 18 of the exemplary embodiment shown in Fig. 1 and 2. Thus, a defined position and orientation of the measuring device, in particular of the transceiver 10 and reflector 32, with respect to the tubular object 24 is ensured, for example on the center axis 40 of the tubular axis 24. Again, the holder 34 provides a stop for placement against the tubular object 24. Again, the transceiver 10 and/or the reflector 32 may be arranged on the holder 34, in particular the legs 36 and/or 38, respectively, so as to be longitudinally displaceable in the direction of the longitudinal axis of the tubular object.
The measuring device shown in Fig. 6 differs from the measuring device shown in Fig. 5 in that a holding portion 42 that is arranged in a stationary manner on, for example, an extrusion device for extruding the tubular object 24 is also provided. The holding portion 42 comprises a base plate 44, which is fastened, for example screwed, on the floor of a production area that houses the extrusion device, for example. The holder 34 may be arranged on the holding portion 42 via a cross-member 46. In this way, a positionally precise arrangement of the measuring device and secure guidance of the measuring device, for example during a rotation about the center axis 40, is ensured during the measurement.
Although the invention has been described based on exemplary embodiments for a tubular object 24, in particular a plastics pipe 24, it should be understood that it may also be used in a corresponding manner for other objects, for example flat objects or solid cylindrical objects. It is also possible that, instead of the narrow, rod-shaped reflector 16 shown in Fig. 1 and 2, a reflector that is adapted to the pipe geometry with, for example, the shape of a cylindrical portion is used. Accordingly, a differently shaped reflector 32 would also be possible in the exemplary embodiments according to Fig. 3 to 5.
In all exemplary embodiments, it is also possible for the transceiver 10 and/or the reflector 16, 32 to be detachably arranged on the holder 14, 30, or, alternatively, 34. This allows either for a measurement without a reflector or for removal of the transceiver 10, for example in order to charge a battery or for data transmission. For example, by removing the reflector 16 in the exemplary embodiment according to Fig. 1 and 2, a measurement in the region of the plastics pipe 24 that has not yet been cut to length or, alternatively, on a planar object would be possible if the refractive index of the material of the plastics pipe 24 were known. The holding portion shown in Fig. 6 may also be provided in the exemplary embodiments according to Fig. 1 to 4.
List of Reference Signs
10 Transceiver
12 Leg
14 Holder
16 Reflector
18 Outer guide rollers
20 Inner guide roller
22 Holding arms
24 Tubular object
26 Evaluation apparatus
28 Line
30 Holder
32 Reflector
34 Holder
36 Leg
38 Leg
40 Center axis
42 Holding portion
44 Base plate
46 Cross-member
The invention relates to a measuring device for measuring a geometric parameter, in particular an inner and/or outer diameter and/or a wall thickness, of a flat or strand-shaped, in particular tubular, object, comprising a transceiver having a transmission apparatus for emitting terahertz radiation onto the object, wherein the terahertz radiation is at least partially reflected by the object, and having a receiving apparatus for receiving the terahertz radiation emitted by the transmission apparatus onto the object, wherein the measuring device is a measuring device that is portable for an operator.
The invention also relates to a method for measuring a geometric parameter, in particular an inner and/or outer diameter and/or a wall thickness of a flat or strand-shaped, in particular tubular, object.
In the manufacture of plastics pipes in extrusion lines, for example, it is desirable to be able to measure geometric parameters, for example wall thicknesses and inner or outer diameters in a flexible manner, at an early stage, and at various locations on the production line. For this purpose, terahertz measuring devices are known from the prior art which emit terahertz radiation onto the object and receive terahertz radiation reflected by the object. For example, geometric parameters such as wall thicknesses or diameters can be determined based on delay time measurements.
For fast and flexible measurement of geometric parameters at different locations on a production line, hand-held devices that can be carried by an operator are helpful. A portable device is known from DE 10 2016 119 728 A1. It comprises a support contour having multiple contact points for positioning the device on the object to be measured. The known portable device can be used, for example, to determine the geometric wall thickness if the refractive index of the material of the object is assumed to be known.
For frequently used plastics materials, such as PE, PP, HDPE, PVDF, PTFE, PVC, etc., in pure form, reliable refractive index values are known for standard conditions. In principle, the refractive index depends on the temperature of the material, on the state of aggregation thereof, and thus on the density thereof, but also on the frequency used. However, in practice, additives are often added to the plastics materials, for example for better protection against UV radiation or to achieve anti-static properties. Additives alter the refractive index and the addition of additives is often subject to fluctuations on account of irregular admixtures or fluctuating proportions of the additives in the supplied plastics materials. The requirements for measuring geometric parameters of pipes of this kind are established in the standard DIN EN ISO 3126. The required level of measuring accuracy is demanding. A change in the refractive index due to added additives can significantly distort a wall thickness measurement with the known portable device if the refractive index is assumed to be constant. Therefore, for reliable measured values for the wall thickness of a plastics material, it is urgently advised to detect the refractive index directly at the measurement location for a wall thickness in order to use same in the calculation of the geometric wall thickness.
In order to determine the refractive index or rather to calibrate a first terahertz measuring apparatus with regard to the refractive index, DE 10 2022 100 650 B3 proposes performing a wall thickness measurement on an already cooled pipe piece using a mechanical tactile measuring apparatus, by means of which a second terahertz measuring device that measures the cooled pipe piece is calibrated. This can in turn be used to calibrate the first terahertz measuring apparatus. In this way, the individual refractive index of the object to be measured can be determined at the measurement location and accurate geometric parameters can thus be determined. However, the calibration procedure is very time-consuming due to the delay time between the first measurement and the final measurements on the cooled pipe being one or more hours. Finally, this method merely provides a value for the refractive index at the first measurement location, i.e. in the so-called hot zone, in which the plastics material has only partially solidified. Aside from the proportion of additives in the plastics material, the temperature thereof, the density, and the state of aggregation of the material also have an influence on the refractive index value.
Proceeding from the explained prior art, the object of the invention is to provide a measuring device and a method of the type mentioned at the outset, by means of which geometric parameters can be determined in a flexible and reliable manner at different locations on the object.
The invention achieves the object through independent claims 1 and 21. Advantageous embodiments are disclosed in the dependent claims, the description, and the figures.
With regard to a measuring device of the type mentioned at the outset, the invention achieves the object in that the measuring device comprises a holder that supports the transceiver as well as a reflector for reflecting the terahertz radiation emitted by the transmission apparatus after said terahertz radiation has passed through at least one portion of the object, wherein the holder is designed such that the measuring device for measuring the geometric parameter of the object can be placed against the object such that the transceiver and the reflector are opposite one another on different sides of the object or a wall of the object.
The object to be measured may, for example, be cylindrical or tubular. It may also be a flat or rather planar object. It is at least partially transparent to the terahertz radiation emitted by the transmission apparatus, such that terahertz radiation emitted onto the object is reflected on boundary surfaces of the object. Some of the terahertz radiation can pass through the object and, after being reflected on the reflector, return to the receiving apparatus, where said radiation and the radiation components reflected by the object are received as measurement signals. The transmission apparatus and the receiving apparatus are designed to be integrated into a transceiver and are, in particular, located at the same location. The object may consist of a plastics material, for example PE, PP, HDPE, PTFE, PVDF, or PVC. However, the object may also consist, for example, of glass or ceramic material or frozen water or wood or construction materials of various types, provided that it is at least partially transparent to the terahertz radiation used. The terahertz radiation may, for example, emit radiation in a frequency range of from 1 GHz to 6 THz, in particular in a frequency range of from 10 GHz to 1.5 THz. The object may be conveyed in a longitudinal direction through a measuring region of the measuring device. For example, the object may have been manufactured in an extrusion device and, for example, be measured by means of the measuring device according to the invention or, alternatively, method according to the invention while still in the extrusion line. The object may still comprise flowable components, i.e. not be completely cooled or rather solidified, at the time of the measurement with the measuring device according to the invention or, alternatively, method according to the invention. This applies, in particular, to a measurement shortly after exit from the extrusion device or a first cooling tank of the extrusion line. The transmission apparatus may emit FMCW terahertz radiation, in particular broadband terahertz radiation.
As already explained, the receiving apparatus receives the terahertz radiation emitted by the transmission apparatus and at least partially reflected by the object. As already explained as well, the receiving apparatus may also receive terahertz radiation that has passed through the object. The measuring device according to the invention is portable for an operator, in particular during the measurement. It is therefore a hand-held device. The measuring device preferably has its own energy supply for electrical energy, in particular a battery, preferably a rechargeable battery. As is known per se, the receiving apparatus may, for example, determine geometric parameters of the object, for example a wall thickness and/or an inner and/or outer diameter, based on delay time measurements of the terahertz radiation reflected at different boundary layers of the object and display the results on a display. For this purpose, the measuring device may comprise a corresponding evaluation apparatus, as will be explained in more detail below.
According to the invention, the measuring device comprises a holder which supports the transceiver as well as a reflector for reflecting the terahertz radiation emitted by the transmission apparatus after said radiation has passed through at least one portion of the object. The holder is designed such that the measuring device can be placed against an object for a measurement process in such a way that the transceiver and the reflector are opposite one another on different sides of the object or on different sides of a wall of the object. Terahertz radiation emitted by the transmission apparatus is thus reflected by the reflector after having passed through the object or the wall of the object, such that, after passing through the object or the wall of the object again, the terahertz radiation returns to the transceiver, in particular the receiving apparatus, where said radiation is detected as a measurement signal. As will be explained in more detail below, it is thus possible to determine the individual refractive index of the material of the object just measured at the same location and thus also to determine reliable and precise measured values of the relevant geometric parameter in the event of a changing composition of the object or even in the event of a composition that is not known with sufficient accuracy, for example due to the addition of additives. At the same time, due to the design of the portable measuring device with the holder, a measurement can be performed by an operator at largely arbitrary locations on the object or rather on a production line for the object. The measurement results are reliable and available quickly. Although measuring devices arranged in a stationary manner can potentially deliver measurement results continuously, the portable measuring device according to the invention can achieve a reliable measurement result in a very flexible manner. On account of the design according to the invention with the holder as well as the transceiver and reflector, the refractive index and measurement results of the geometric parameter based thereon can be obtained in one measuring step. Reliable documentation for acceptance of the object within the context of a production line is thus also possible.
In contrast to the hand-held device of the prior art explained at the outset, the measuring device according to the invention does not rely on presuming the refractive index of the object to be known. Rather, the precise value of the refractive index of the object is recorded directly at the measurement location itself and included in the calculation of the measured values for the geometric parameter. As a result, the requirements imposed by the standard DIN EN ISO 3126 are fully met.
Provided that the transceiver and the reflector are opposite one another on different sides of a wall of the object in the state placed against the object, the measuring device can, for example, be placed at the end of a tubular object, for example subsequently to production, i.e. immediately before and also after the tubular object is cut to length. The reflector or the transceiver is then arranged inside the tubular object, while the other of the two is arranged opposite on the outer face of the tubular object. According to the invention, in addition to wall thicknesses and diameters, ovalities of a tubular object, for example, can also be reliably determined as geometric parameters during production or subsequently to production by measuring, for example, the inner or outer diameter multiple times over the circumference of the object. For this purpose, the measuring device can be rotated as a whole or, for example, only the transceiver can be rotated about a longitudinal axis, for example, of a tubular object while the reflector remains still. For the rotation, the measuring device may comprise a rotary drive. By measuring around the circumference of the object, in addition to wall thickness fluctuations, it is possible, for example, to identify inhomogeneities in the material of the object, for example an inhomogeneous distribution of additives around the circumference of the object. The measuring device could also detect an absorption of the terahertz radiation caused by the object, for example by comparing the terahertz radiation emitted and then recovered after being reflected on the reflector. In this way, the portable measuring device is also well suited for checking whether the object or rather a material of the object can be measured in the manner according to the invention and, if applicable, to what thickness.
In principle, the portable device should be suitable for measuring small and large objects and, if applicable, also at short distances from the surface of the object. The antenna of the transceiver should thus have a high gain of preferably 20 to 30 dBi and a sensitivity that is sufficient with the accompanying amplitudes. In order to prevent overmodulation of the reception signal, closed-loop control of the transmission power that allows for adaptation to the relevant situation of the reception signals can be useful. Sufficiently fast control is useful, for example, in order to be able to perform a measuring process at a different transmission power, adapted to a front and rear wall thickness of a pipe, for example.
According to a particularly practical embodiment, the holder may be C-shaped. The transceiver and the reflector may then be arranged at the opposite free ends of the C-shaped holder. A C-shaped holder of this kind may, for example, consist of plastics material, for example a carbon fiber-reinforced plastics material. Provided that a C-shaped or curved holder of the measuring device is sufficiently large, the transceiver and the reflector can, for example, be positioned on opposing outer faces of the object during measurement of a tubular object.
The holder may form a stop which can be placed against an end face of the object for placement of the measuring device. In this way, a defined position of the measuring device relative to the object, in particular an end face of a flat object or a pipe that has already been cut to length, is made available. For example, when measuring the wall thickness of pipes, a particular distance from the cut edge of the pipe, for example at least 50 mm, is often prescribed. Due to the stresses released in the material, there are often no reliable values for the wall thickness at the cut edges themselves. The prescribed distance from the cut edge can be ensured at all times with the above-mentioned design. This also applies, for example, to a measurement of the wall thickness over the circumference of the pipe.
According to a further embodiment, in order to allow for adjustability of the distance from an edge, for example a cut edge, of the object in order to adapt to different requirements or conditions, it can be provided that the transceiver and/or the reflector is mounted on the holder in a longitudinally displaceable manner, in particular in the longitudinal direction of the object in the state placed against the object.
According to a further embodiment, the transceiver and/or the reflector may be detachably arranged on the holder. In this way, a measurement with the measuring device is possible with or without the reflector as needed. A measurement without a reflector is useful, for example, if the refractive index of the material of the object is known to a sufficiently reliable extent even without a corresponding measurement. A combination of the measuring device with a reflector arranged, for example, in a stationary manner on a production line of the object, for example an extrusion line of a tubular object, is then possible as well. A stationary reflector of this kind could, for example, be arranged at the start of an extrusion line for the object, for example at the outlet of a first cooling tank in which the object undergoes a first cooling after exiting the extrusion device. If, for example, the reflector arranged in a stationary manner also has a receiving portion for the transceiver of the measuring device or the holder of the measuring device, a precise orientation would thus be ensured at all times for the measurement. Particularly simple mounting of a reflector in combination with a holder for a transceiver, for example directly at the outlet of a first cooling tank or, alternatively, upstream of the inlet into a further cooling tank or, alternatively, between further cooling tanks of the production line can thus be achieved and ensures a high degree of repeatability for the measurement path between the transceiver and the reflector. Therefore, an accurate measurement in the warm zone of the production line is possible, i.e. when the object thus still has flowable components and is thus still subject to a certain amount of shrinkage and sagging. Although measurement results that may deviate from the final geometric parameters of the fully solidified object are obtained in this warm zone, they can be an important aid when setting up the production line, in particular when presetting an extrusion device with regard to the wall thickness and the expected sagging. It is currently common practice to mechanically measure the outer dimension of the diameter of a tubular object in the warm zone using a tape measure. Here, the invention allows for simple non-contact detection using the measuring device. With knowledge of the outer diameter, for example, of a tubular object and with the measurement of the inner diameter by means of the measuring device according to the invention, the double wall thickness of the tubular object can be ascertained and individual geometric wall thickness values can be determined from the detected optical wall thickness values both at the front and at the rear. Detachment of the transceiver from the holder may also be useful, for example in order to recharge a battery of the transceiver or to change to another transceiver or the like. Even a folding design of the reflector, for example, is conceivable such that the reflector can be used while still held on the holder and either folded into the measurement path or folded out thereof.
A detachable design of the transceiver on the holder also has the advantage that the transceiver can be combined with different holders, depending on the intended use. Accordingly, the measuring device may also comprise multiple holders that are designed in the manner according to the invention and that are optimized for different purposes. The detachable arrangement of the reflector on the holder also allows for simple yet precise and user-friendly locking of the reflector. In order to precisely determine the geometric dimensions, the wall thickness, the wall thickness and/or diameter values, exact determination of the refractive index is important, namely the detection of the delay time differences between direct irradiation of the reflector and irradiation thereof after radiation has passed through materials, which increases the delay time. This means that no changes in distance in the range of a few micrometers can take place between calibration of the distance of the reflector and practical use thereof. In the case of a refractive index of typically 1.5 for plastics materials and approximately 2 for glass, this means that approximately one third of any change in distance of the reflector is included in the wall thickness value in the case of plastics materials, and one half in the case of glass. Thus, a precise arrangement of the transceiver and reflector is particularly important.
According to a further embodiment, the reflector may be spaced apart from a wall of the object that is adjacent to the reflector and through which the terahertz radiation passes in the state of the measuring device placed against the object. There is therefore a certain distance between the reflector and the portion of the object to be measured, for example the wall of the object. In this way, echoes of the reflector and of the spaced-apart surface, for example an inner wall of a tubular object, can be reliably separated in the measurement signal.
The holder may further comprise at least one support by means of which the transceiver and/or the reflector rests on a surface of the object in the state placed against the object. On account of a support of this kind, a defined arrangement or rather position of the transceiver and/or reflector in relation to the object to be measured is ensured. The at least one receiving portion may, for example, comprise at least one guide runner or rather skid. It is also possible, for example, for the at least one support to comprise at least one guide roller that rests on the surface of the object in the state placed against the object. The at least one support may be adjustable in order to adapt to different dimensions of the object. For example, the at least one support may comprise at least two support portions that are spaced apart from one another and that can be pressed apart counter to a preload. The preload may, for example, be provided by means of a preload spring. The at least one support can be adapted to different dimensions of the object manually. However, an electric drive, for example, is also conceivable. Instead of a preload by means of a preload spring, another design, for example, is also conceivable, for example a resilient toothed belt with outward-facing teeth. A particularly practical design in this regard may, for example, comprise two support portions that can be adapted in order to adapt to different dimensions of the object and that, for example, can be placed on an outer face of the object as well as comprise a support portion arranged on the opposite side for abutting an inner face of the object.
At least one sensor may also be provided, by means of which the measuring device with the holder can be oriented for a measurement process without contacting the object. The at least one sensor may, for example, comprise at least one optical sensor and/or at least one inertial sensor and/or at least one position sensor. In this case, the measuring device may also be oriented without mechanical guidance, for example using optical orientation with three or four distance sensors, for example time-of-flight sensors. For the measurement itself, the distance, for example from the transceiver to the surface of the object, is of little importance. However, an orientation that is as vertical as possible, i.e. 90° to the measuring plane, is important. The orientation with optical sensors may, for example, take place in that a symbol, for example a reticle, is displayed on a display or the like with manual triggering of the measurement or with automatic recognition and automated triggering of the measurement when, for example, a vertical orientation is achieved. Orientation using gyroscopic sensors or using the transceiver itself would also be conceivable. It is also possible for the transmission apparatus to transmit as early as during the orientation procedure and to use the corresponding measured values received by the receiving apparatus when an optimal orientation is detected, for example by means of corresponding inertial or position sensors. When using position sensors, it is also possible, for example, to assign the measured values to different positions on the circumference of a tubular object.
According to a further embodiment, the reflector may have the shape of a cylindrical portion. This can simplify guidance of the measuring device, in particular if the cylindrical shape is adapted to the geometry of a tubular object, in particular a curvature aligned with the center axis of a tubular object. In particular in conjunction with the detachable arrangement of the reflector on the holder, differently shaped reflectors, for example reflectors with different cylinder radii, can be used, in particular in order to adapt to differently sized objects. In this way, geometric parameters of very small pipes, for example, can also be measured reliably.
Depending on the use of the measuring device, the reflector can be used, for example, to measure the wall thickness at the edge of an object or merely to detect the refractive index of the material for further measurements of the same object. According to a further embodiment, the reflector may be partially transparent to the terahertz radiation emitted by the transmission apparatus. In this case, some of the terahertz radiation emitted by the transmission apparatus is reflected by the reflector, while some passes through the reflector. A 100% reflective reflector is known in optics as an integrating sphere. For optimal reflection of the transmitted high frequency, said reflector should be shaped such that its center point is located in the region of the transmission/reception antenna of the transceiver. This also applies to the reflector according to the invention. Alignment of the curvature of the reflector with the center point, for example, of a pipe would only be optimal if the antenna of the transceiver were also aligned with the center point of the pipe. A partially reflective reflector may be useful, in particular, if a wall of the object located between the transceiver and the reflector as well as a wall arranged on a side of the reflector facing away from the transceiver are to be measured in the case of an arrangement of the reflector inside a tubular object. Using a partially transparent reflector makes it possible to measure the refractive index of the material of the object and also the wall thickness of both wall portions of the tubular object and, at the same time, the outer and inner diameter. A two-part design of the reflector with two reflector portions arranged symmetrically with respect to one another would also be conceivable.
A narrow design of the reflector is also possible, such that some of the terahertz radiation emitted by the transmission apparatus strikes the reflector and is reflected thereby, and some of the terahertz radiation passes by the reflector. In this case, it is also possible to determine the refractive index and to measure the wall thickness and the inner and outer diameter in the case of a reflector that reflects all of the terahertz radiation. It is particularly advantageous to design the reflector such that it has a correspondingly narrow contour, such that enough signal can make it back from the reflector to the transceiver in spite of the wall thickness to travel through and such that a sufficient amount of the radiation can pass through in order to examine the second wall thickness of a pipe and thus to determine both wall thicknesses, as well as the inner and outer diameter of a pipe. For a hand-held measuring device, it is of practical importance if a device is small and handy and also has small dimensions. This can be achieved with a correspondingly narrow reflector.
According to a further embodiment, the holder may be flexible. For example, if it is designed to be curved, it can thus be adapted to different sizes of the object. Possible materials for the holder are, in principle, plastics materials or metals. Even glass fiber-reinforced or carbon fiber-reinforced plastics materials could be used. Flexible holders may consist, in particular, of plastics material.
The measuring device may further comprise a holding portion which can be arranged or, alternatively, is arranged in a stationary manner on a manufacturing apparatus for manufacturing the object and to which the transceiver and/or the holder can be fastened or, alternatively, is fastened in a detachable manner. For example, the holding portion may comprise a base plate which can rest on the floor of a production area that houses the manufacturing apparatus. The base plate may be fastenable to the floor, for example via a screw connection or the like. The holding portion may form a stand and ensures positionally precise arrangement and, if applicable, guidance of the measuring device around the circumference of the object to be measured. In this way, for example, the wall thickness can be detected in a particularly precise manner via the circumference and/or an outer and/or inner diameter and/or an ovality of a, for example, tubular object. The manufacturing apparatus may comprise an extrusion device in which the object is manufactured by means of extrusion.
The measuring device according to the invention may further comprise an evaluation apparatus which is designed to determine a geometric parameter, in particular a wall thickness and/or an inner and/or outer diameter, of the object based on measured values received by the receiving apparatus. As explained at the outset, the corresponding geometric parameters may be determined, for example, based on delay time measurements. The evaluation apparatus may be integrated in the transceiver or it may be separate therefrom. The transceiver may also comprise a display apparatus for the recorded measured values and the detected refractive index. As a result, an operator can read off the corresponding values quickly and easily. If the evaluation apparatus is separate from the transceiver, it may, for example, comprise a charging station for the transceiver. The transceiver may also be equipped with a network or Internet interface, for example a LAN interface. It is also possible for the transceiver to be operated autonomously with a Power-over-Ethernet (PoE) connection. It is also possible for the holder to be equipped with a LAN connection to a separately arranged evaluation apparatus or to a further measuring device, and/or with a voltage supply for the transceiver, for example in combination with a charging device for a battery of the measuring device. As already explained, the voltage supply may take place via a combined Power-over-Ethernet connection. For example, the transceiver may transmit its measurement data to a central evaluation unit or to another measuring apparatus that is, for example, arranged in a stationary manner on an extrusion line. This may, for example, be a measuring apparatus which is arranged in the warm zone of the extrusion line, i.e. at a short distance from the extruder. As explained, in this warm zone the object has regions that have not yet solidified.
The evaluation apparatus may further be designed to determine the refractive index of the object from a comparison of the delay time of the terahertz radiation emitted by the transmission apparatus and received by the receiving apparatus with said radiation passing through the object with the delay time of the terahertz radiation emitted by the transmission apparatus and received by the receiving apparatus without said radiation passing through the object. Such determination of the refractive index is explained, for example, in WO 2016/139155 A1 and can be used in the present case.
The measuring device may further comprise a wireless transmission apparatus for transmitting measured values received by the receiving apparatus to an evaluation apparatus that is separate from the measuring device and/or for transmitting data evaluated by an evaluation apparatus integrated in the measuring device to a control apparatus that is separate from the measuring device. The measuring device may, for example, be equipped with WLAN data transmission. Between usage times, the measuring device or rather the transceiver may, for example, be arranged in a charging station for charging a battery of the measuring device or rather the transceiver. The charging station may optionally be connected, for example via a wired or wireless data connection, to the control apparatus or to a further measuring device. In this way, corresponding documentation can take place. Moreover, the measured values received from the measuring device can be used for the control, for example, of a production line for the object, for example an extrusion line having an extrusion device. The measured values may also be used, for example, to check or even correct measured values of a stationary terahertz measuring device for determining geometric parameters of the object, in particular with a view to expected shrinkage or, alternatively, expected sagging of the object.
The evaluation apparatus may be an evaluation apparatus that is specially assigned to the measuring device. However, it is also possible for the evaluation apparatus to be a central evaluation apparatus which performs further tasks, for example actuation of an extrusion device based on the measurement results and/or said central evaluation apparatus is assigned to a further measuring apparatus and archives the measurement results of the measuring device and/or the measurement results of the further measuring apparatus and/or corrects values for shrinkage and/or sagging of the object based on the measurement results of the measuring device and/or the measurement results of the further measuring device, for example for control of an extrusion device.
In principle, the measuring device according to the invention may comprise all functions required for detecting objects and representing the result in the form of visible or audible signaling, or alternatively to detect objects, dimensions, etc., and display the results on a display. The evaluation apparatus is not strictly required, but it can advantageously be used, for example, to register, document, or use measured values or to optimize a process, e.g. in the manufacture of pipes or plates.
The invention also relates to a system comprising a measuring device according to the invention as well as the object. The system may further comprise a conveying apparatus for conveying the object in a longitudinal direction through a measuring region of the measuring device. The system according to the invention may also comprise a manufacturing apparatus, for example an extrusion device, for manufacturing the object.
The invention further achieves the object by means of a method for measuring a geometric parameter, in particular an inner and/or outer diameter and/or a wall thickness of a flat or strand-shaped, in particular tubular, object using a measuring device according to the invention or using a system according to the invention. As already explained, according to the invention, the measured values may be recorded at different positions on a production line for the object, for example, said production line being an extrusion line, for example. According to the invention, aside from regions in which the object has already attained its final geometry, i.e. in particular fully cooled or rather solidified, for example after or immediately before an object manufactured in an extrusion device has been cut to length, it is also possible to measure in the warm zone of the production line in particular, i.e. when the object still has flowable components and shrinkage and/or sagging is not yet complete. This has been explained above. On account of the portable design of the measuring device with the above-mentioned possible embodiments, a reliable measurement with quickly available results is also possible when the refractive index is not presumed to be known.
Exemplary embodiments of the invention are explained below in greater detail with reference to schematic figures, in which:
Fig. 1 shows a measuring device according to the invention according to a first exemplary embodiment in a first view,
Fig. 2 shows the measuring device from Fig. 1 in a view that has been rotated by 90° with respect to Fig. 1,
Fig. 3 shows a measuring device according to the invention according to a further exemplary embodiment in a view corresponding to Fig. 1,
Fig. 4 shows the measuring device from Fig. 3 in a view that has been rotated by 90° with respect to Fig. 3,
Fig. 5 shows a measuring device according to the invention according to a further exemplary embodiment in a view corresponding to Fig. 4, and
Fig. 6 shows a measuring device according to the invention according to a further exemplary embodiment in a view corresponding to Fig. 5.
The same reference signs refer to the same objects in the figures unless indicated otherwise.
The measuring device according to the invention shown in Fig. 1 and 2 comprises a transceiver 10 having a transmission apparatus for emitting terahertz radiation and having a receiving apparatus for receiving the terahertz radiation emitted by the transmission apparatus. In the example shown, the transceiver 10 is arranged on a leg 12 of a C-shaped holder 14, on the free end of which opposite the leg 12 a reflector 16 is arranged, which reflector is preferably partially transparent to the terahertz radiation emitted by the transmission apparatus, such that it reflects some of the terahertz radiation back to the transceiver 10 and thus to the receiving apparatus and allows some of the terahertz radiation to pass through. The holder 14 further comprises two outer guide rollers 18 and an inner guide roller 20. Fig. 2 does not show the outer guide rollers 18. The outer guide rollers 18 are in each case arranged at an outer end of a holding arm 22. The holding arms 22 form a V-shape and can be pressed apart by means of the guide rollers 18 against a preload provided, for example, by a preload spring. As shown in Fig. 1 and 2, the measuring device may, for example, be placed against a tubular object 24, in particular a plastics pipe 24, such that the outer guide rollers 18 rest on the outer face of the plastics pipe 24 and the inner guide roller 20 rests on the inner face of the plastics pipe 24. Due to the possibility of pressing the guide rollers 18 apart, same can be adapted to different pipe dimensions. Furthermore, as is visible in Fig. 2 in particular, the holder 14 forms a stop which can be placed against an end face of the tubular object 24 for placement of the measuring device. The transceiver 10 may be mounted on the holder 14, in particular the leg 12, in a longitudinally displaceable manner, in particular in the longitudinal direction of the tubular object 24, i.e. in the horizontal direction in Fig. 2. The reflector 16 may also be mounted on the holder 14 in a longitudinally displaceable manner, if desired. In this way, a defined orientation and position of the measuring device, in particular of the transceiver 10 and the reflector 16, relative to the tubular object 24 to be measured is ensured. The measuring device further comprises an evaluation apparatus 26, which may be connected to the transceiver 10 via a wireless data connection, for example.
During operation, the transmission apparatus of the transceiver 10 emits terahertz radiation onto the tubular object 24 to be measured, i.e. vertically downward in Fig. 1 and 2, as illustrated in Fig. 2 by the dashed line 28. The terahertz radiation is reflected on boundary surfaces of the tubular object 24, in particular the outer and inner faces of the wall portions, as well as completely or partially on the reflector 16. After being reflected, the terahertz radiation returns to the transceiver 10 and is detected as a measurement signal by the receiving apparatus. The evaluation apparatus 26, which obtains the measured values, can use the delay time measurements, for example, to determine the optical thickness of the wall portions of the tubular object 24 and thus the outer and inner diameter of the tubular object 24. In order to determine herefrom the geometric values of the corresponding geometric parameters, the refractive index of the material of the tubular object 24 must be taken into account. For this purpose, the evaluation apparatus 26 can determine the refractive index of the tubular object 24 from the comparison of the delay time of the terahertz radiation emitted by the transmission apparatus and received by the receiving apparatus with said radiation passing through the tubular object 24 with the delay time of the terahertz radiation emitted by the transmission apparatus and received by the receiving apparatus without said radiation passing through the tubular object 24, in each case using the terahertz radiation reflected by the reflector 16. Since the measuring device shown in Fig. 1 and 2 is designed such that the reflector 16 is arranged inside the plastics pipe 24, a measurement is accordingly possible from an end face of the plastics pipe 24, in particular after the plastics pipe 24 has been cut to length after being manufactured in an extrusion line, for example.
As explained, the evaluation apparatus 26 may be integrated in the transceiver 10. A power supply for charging a battery, for example, may be separate from the transceiver, for example. As also explained, the reflector 16 does not have to be partially transparent.
Fig. 3 and 4 show a further exemplary embodiment of a measuring device according to the invention, by means of which a tubular object 24, in particular a plastics pipe 24, that has not yet been cut to length can, in particular, also be measured, in particular in the warm zone shortly after exiting an extrusion device or after exiting a first cooling tank, when the tubular object 24 thus still has flowable components. For this purpose, a curved holder 30 is provided, at one free end of which the transceiver 10 of the measuring device is arranged and at the other free end of which a reflector 32 is arranged, which reflector, in the example shown, has the shape of a cylindrical portion in adaptation to the geometry of the tubular object 24. The holder 30 may, for example, consist of a plastics material and be flexible. The holder allows for placement against the tubular object 24 from the outside, wherein the transceiver 10 and the reflector 32 are located on opposite outer faces of the tubular object 24. As illustrated again by the dashed line 28, terahertz radiation emitted by the transmission apparatus of the transceiver 10 is reflected on boundary surfaces of the tubular object 24 and on the reflector 32 arranged on the opposite side of the tubular object 24. The radiation components reflected in each case return to the receiving apparatus and are received thereby as measured values, which are in turn sent to the evaluation apparatus 26. The transceiver 10 may also comprise a display for representing the measured values. On this basis and in the manner explained above, the measuring device or rather the evaluation apparatus 26 can determine the refractive index of the material of the the refractive index of the material of the plastics pipe 24 and the wall thicknesses as well as the outer and inner diameters of the tubular object 24.
As explained, the evaluation apparatus 26 may be an evaluation apparatus 26 that is specially provided for the measuring device. However, it is also possible for the evaluation apparatus 26 to be a central evaluation apparatus which, for example, actuates an extrusion device and/or is assigned to a further measuring apparatus, as explained above.
Fig. 5 shows a further exemplary embodiment of a measuring device according to the invention, which differs from the exemplary embodiment according to Fig. 3 and 4 with regard to the holder 34. Said holder is designed similarly to the holder 14 in Fig. 1 and 2 with two opposing legs 36, 38. The transceiver 10 is arranged on the leg 36 and the reflector 32 is arranged on the leg 38 and may have a curvature like the reflector 32 shown in Fig. 3 and 4. In the exemplary embodiment shown in Fig. 5, the holder 34 may have guide rollers which are arranged on the legs 36, 38, abut opposing outer faces of the tubular object 24 in the state placed against the tubular object 24, and may be designed, for example, in the manner of the guide rollers 18 of the exemplary embodiment shown in Fig. 1 and 2. Thus, a defined position and orientation of the measuring device, in particular of the transceiver 10 and reflector 32, with respect to the tubular object 24 is ensured, for example on the center axis 40 of the tubular axis 24. Again, the holder 34 provides a stop for placement against the tubular object 24. Again, the transceiver 10 and/or the reflector 32 may be arranged on the holder 34, in particular the legs 36 and/or 38, respectively, so as to be longitudinally displaceable in the direction of the longitudinal axis of the tubular object.
The measuring device shown in Fig. 6 differs from the measuring device shown in Fig. 5 in that a holding portion 42 that is arranged in a stationary manner on, for example, an extrusion device for extruding the tubular object 24 is also provided. The holding portion 42 comprises a base plate 44, which is fastened, for example screwed, on the floor of a production area that houses the extrusion device, for example. The holder 34 may be arranged on the holding portion 42 via a cross-member 46. In this way, a positionally precise arrangement of the measuring device and secure guidance of the measuring device, for example during a rotation about the center axis 40, is ensured during the measurement.
Although the invention has been described based on exemplary embodiments for a tubular object 24, in particular a plastics pipe 24, it should be understood that it may also be used in a corresponding manner for other objects, for example flat objects or solid cylindrical objects. It is also possible that, instead of the narrow, rod-shaped reflector 16 shown in Fig. 1 and 2, a reflector that is adapted to the pipe geometry with, for example, the shape of a cylindrical portion is used. Accordingly, a differently shaped reflector 32 would also be possible in the exemplary embodiments according to Fig. 3 to 5.
In all exemplary embodiments, it is also possible for the transceiver 10 and/or the reflector 16, 32 to be detachably arranged on the holder 14, 30, or, alternatively, 34. This allows either for a measurement without a reflector or for removal of the transceiver 10, for example in order to charge a battery or for data transmission. For example, by removing the reflector 16 in the exemplary embodiment according to Fig. 1 and 2, a measurement in the region of the plastics pipe 24 that has not yet been cut to length or, alternatively, on a planar object would be possible if the refractive index of the material of the plastics pipe 24 were known. The holding portion shown in Fig. 6 may also be provided in the exemplary embodiments according to Fig. 1 to 4.
List of Reference Signs
10 Transceiver
12 Leg
14 Holder
16 Reflector
18 Outer guide rollers
20 Inner guide roller
22 Holding arms
24 Tubular object
26 Evaluation apparatus
28 Line
30 Holder
32 Reflector
34 Holder
36 Leg
38 Leg
40 Center axis
42 Holding portion
44 Base plate
46 Cross-member
Claims
1. A measuring device for measuring a geometric parameter, in particular an inner and/or outer diameter and/or a wall thickness, of a flat or strand-shaped, in particular tubular, object (24), comprising a transceiver (10) having a transmission apparatus for emitting terahertz radiation onto the object, wherein the terahertz radiation is at least partially reflected by the object (24), and having a receiving apparatus for receiving the terahertz radiation emitted by the transmission apparatus onto the object (24), wherein the measuring device is a measuring device that is portable for an operator,
characterized in that the measuring device comprises a holder (14, 30, 34) that supports the transceiver (10) as well as a reflector (16, 32) for reflecting the terahertz radiation emitted by the transmission apparatus after said terahertz radiation has passed through at least one portion of the object (24), wherein the holder (14, 30, 34) is designed such that the measuring device for measuring the geometric parameter of the object (24) can be placed against the object (24) such that the transceiver (10) and the reflector (16, 32) are opposite one another on different sides of the object (24) or a wall of the object (24).
2. The measuring device according to any one of the preceding claims, characterized in that the holder (14, 30, 34) is C-shaped.
3. The measuring device according to any one of the preceding claims, characterized in that the holder (14, 30, 34) forms a stop which can be placed against an end face of the object (24) for placement of the measuring device.
4. The measuring device according to any one of the preceding claims, characterized in that the transceiver (10) and/or the reflector (16, 32) is mounted in a longitudinally displaceable manner on the holder (14, 30, 34).
5. The measuring device according to any one of the preceding claims, characterized in that the transceiver (10) and/or the reflector (16, 32) are detachably arranged on the holder (14, 30, 34).
6. The measuring device according to any one of the preceding claims, characterized in that the reflector (16, 32) is spaced apart from a wall of the object (24) that is adjacent to the reflector (16, 32) and through which the terahertz radiation passes in the state of the measuring device placed against the object (24).
7. The measuring device according to any one of the preceding claims, characterized in that the holder (14, 30, 34) comprises at least one support by means of which the transceiver (10) and/or the reflector (16, 32) rests on a surface of the object (24) in the state placed against the object (24).
8. The measuring device according to claim 7, characterized in that the at least one support comprises at least one guide roller (18, 20) that rests on the surface of the object (24) in the state placed against the object (24).
9. The measuring device according to any one of claims 7 or 8, characterized in that the at least one support is adjustable in order to adapt to different dimensions of the object (24).
10. The measuring device according to claim 9, characterized in that the at least one support comprises at least two support portions that are spaced apart from one another and that can be pressed apart counter to a preload.
11. The measuring device according to any one of the preceding claims, characterized in that at least one sensor is also provided, by means of which the measuring device with the holder (14, 30, 34) can be oriented for a measurement process without contacting the object (24).
12. The measuring device according to claim 11, characterized in that the at least one sensor comprises at least one optical sensor and/or at least one inertial sensor and/or at least one position sensor.
13. The measuring device according to any one of the preceding claims, characterized in that the reflector (16, 32) has the shape of a cylindrical portion.
14. The measuring device according to any one of the preceding claims, characterized in that the reflector (16, 32) is partially transparent to the terahertz radiation emitted by the transmission apparatus.
15. The measuring device according to any one of the preceding claims, characterized in that it further comprises a holding portion (42) which can be arranged in a stationary manner on a manufacturing apparatus for manufacturing the object and to which the transceiver (10) and/or the holder (14, 30, 34) can be fastened in a detachable manner.
16. The measuring device according to any one of the preceding claims, characterized in that it further comprises an evaluation apparatus (26) which is designed to determine a geometric parameter, in particular a wall thickness and/or an inner and/or outer diameter, of the object (24) based on measured values received by the receiving apparatus.
17. The measuring device according to claim 16, characterized in that the evaluation apparatus (26) is further designed to determine the refractive index of the object (24) from a comparison of the delay time of the terahertz radiation emitted by the transmission apparatus and received by the receiving apparatus with said radiation passing through the object (24) with the delay time of the terahertz radiation emitted by the transmission apparatus and received by the receiving apparatus without said radiation passing through the object (24).
18. The measuring device according to any one of the preceding claims, characterized in that the measuring device comprises a wireless transmission apparatus for transmitting measured values received by the receiving apparatus to an evaluation apparatus (26) that is separate from the measuring device and/or for transmitting data evaluated by an evaluation apparatus (26) integrated in the measuring device to a control apparatus that is separate from the measuring device.
19. A system, comprising a measuring device according to any one of the preceding claims and the object (24).
20. The system according to claim 19, characterized in that it further comprises a conveying apparatus for conveying the object (24) in a longitudinal direction through a measuring region of the measuring device.
21. A method for measuring a geometric parameter, in particular an inner and/or outer diameter and/or a wall thickness, of a flat or strand-shaped, in particular tubular, object (24) using a measuring device according to any one of claims 1 to 18 or using a system according to any one of claims 19 or 20.
1. A measuring device for measuring a geometric parameter, in particular an inner and/or outer diameter and/or a wall thickness, of a flat or strand-shaped, in particular tubular, object (24), comprising a transceiver (10) having a transmission apparatus for emitting terahertz radiation onto the object, wherein the terahertz radiation is at least partially reflected by the object (24), and having a receiving apparatus for receiving the terahertz radiation emitted by the transmission apparatus onto the object (24), wherein the measuring device is a measuring device that is portable for an operator,
characterized in that the measuring device comprises a holder (14, 30, 34) that supports the transceiver (10) as well as a reflector (16, 32) for reflecting the terahertz radiation emitted by the transmission apparatus after said terahertz radiation has passed through at least one portion of the object (24), wherein the holder (14, 30, 34) is designed such that the measuring device for measuring the geometric parameter of the object (24) can be placed against the object (24) such that the transceiver (10) and the reflector (16, 32) are opposite one another on different sides of the object (24) or a wall of the object (24).
2. The measuring device according to any one of the preceding claims, characterized in that the holder (14, 30, 34) is C-shaped.
3. The measuring device according to any one of the preceding claims, characterized in that the holder (14, 30, 34) forms a stop which can be placed against an end face of the object (24) for placement of the measuring device.
4. The measuring device according to any one of the preceding claims, characterized in that the transceiver (10) and/or the reflector (16, 32) is mounted in a longitudinally displaceable manner on the holder (14, 30, 34).
5. The measuring device according to any one of the preceding claims, characterized in that the transceiver (10) and/or the reflector (16, 32) are detachably arranged on the holder (14, 30, 34).
6. The measuring device according to any one of the preceding claims, characterized in that the reflector (16, 32) is spaced apart from a wall of the object (24) that is adjacent to the reflector (16, 32) and through which the terahertz radiation passes in the state of the measuring device placed against the object (24).
7. The measuring device according to any one of the preceding claims, characterized in that the holder (14, 30, 34) comprises at least one support by means of which the transceiver (10) and/or the reflector (16, 32) rests on a surface of the object (24) in the state placed against the object (24).
8. The measuring device according to claim 7, characterized in that the at least one support comprises at least one guide roller (18, 20) that rests on the surface of the object (24) in the state placed against the object (24).
9. The measuring device according to any one of claims 7 or 8, characterized in that the at least one support is adjustable in order to adapt to different dimensions of the object (24).
10. The measuring device according to claim 9, characterized in that the at least one support comprises at least two support portions that are spaced apart from one another and that can be pressed apart counter to a preload.
11. The measuring device according to any one of the preceding claims, characterized in that at least one sensor is also provided, by means of which the measuring device with the holder (14, 30, 34) can be oriented for a measurement process without contacting the object (24).
12. The measuring device according to claim 11, characterized in that the at least one sensor comprises at least one optical sensor and/or at least one inertial sensor and/or at least one position sensor.
13. The measuring device according to any one of the preceding claims, characterized in that the reflector (16, 32) has the shape of a cylindrical portion.
14. The measuring device according to any one of the preceding claims, characterized in that the reflector (16, 32) is partially transparent to the terahertz radiation emitted by the transmission apparatus.
15. The measuring device according to any one of the preceding claims, characterized in that it further comprises a holding portion (42) which can be arranged in a stationary manner on a manufacturing apparatus for manufacturing the object and to which the transceiver (10) and/or the holder (14, 30, 34) can be fastened in a detachable manner.
16. The measuring device according to any one of the preceding claims, characterized in that it further comprises an evaluation apparatus (26) which is designed to determine a geometric parameter, in particular a wall thickness and/or an inner and/or outer diameter, of the object (24) based on measured values received by the receiving apparatus.
17. The measuring device according to claim 16, characterized in that the evaluation apparatus (26) is further designed to determine the refractive index of the object (24) from a comparison of the delay time of the terahertz radiation emitted by the transmission apparatus and received by the receiving apparatus with said radiation passing through the object (24) with the delay time of the terahertz radiation emitted by the transmission apparatus and received by the receiving apparatus without said radiation passing through the object (24).
18. The measuring device according to any one of the preceding claims, characterized in that the measuring device comprises a wireless transmission apparatus for transmitting measured values received by the receiving apparatus to an evaluation apparatus (26) that is separate from the measuring device and/or for transmitting data evaluated by an evaluation apparatus (26) integrated in the measuring device to a control apparatus that is separate from the measuring device.
19. A system, comprising a measuring device according to any one of the preceding claims and the object (24).
20. The system according to claim 19, characterized in that it further comprises a conveying apparatus for conveying the object (24) in a longitudinal direction through a measuring region of the measuring device.
21. A method for measuring a geometric parameter, in particular an inner and/or outer diameter and/or a wall thickness, of a flat or strand-shaped, in particular tubular, object (24) using a measuring device according to any one of claims 1 to 18 or using a system according to any one of claims 19 or 20.
Abstract
The invention relates to a measuring device for measuring a geometric parameter, in particular an inner and/or outer diameter and/or a wall thickness, of a flat or strand-shaped, in particular tubular, object, comprising a transceiver having a transmission apparatus for emitting terahertz radiation onto the object, wherein the terahertz radiation is at least partially reflected by the object, and having a receiving apparatus for receiving the terahertz radiation emitted by the transmission apparatus onto the object, wherein the measuring device is a measuring device that is portable for an operator, wherein the measuring device comprises a holder that supports the transceiver as well as a reflector for reflecting the terahertz radiation emitted by the transmission apparatus after said terahertz radiation has passed through at least one portion of the object, wherein the holder is designed such that the measuring device for measuring the geometric parameter of the object can be placed against the object such that the transceiver and the reflector are opposite one another on different sides of the object or a wall of the object. The invention also relates to a corresponding method.
The invention relates to a measuring device for measuring a geometric parameter, in particular an inner and/or outer diameter and/or a wall thickness, of a flat or strand-shaped, in particular tubular, object, comprising a transceiver having a transmission apparatus for emitting terahertz radiation onto the object, wherein the terahertz radiation is at least partially reflected by the object, and having a receiving apparatus for receiving the terahertz radiation emitted by the transmission apparatus onto the object, wherein the measuring device is a measuring device that is portable for an operator, wherein the measuring device comprises a holder that supports the transceiver as well as a reflector for reflecting the terahertz radiation emitted by the transmission apparatus after said terahertz radiation has passed through at least one portion of the object, wherein the holder is designed such that the measuring device for measuring the geometric parameter of the object can be placed against the object such that the transceiver and the reflector are opposite one another on different sides of the object or a wall of the object. The invention also relates to a corresponding method.