JP2006292378A - Ultrasonic flowmeter - Google Patents

Ultrasonic flowmeter Download PDF

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JP2006292378A
JP2006292378A JP2005109104A JP2005109104A JP2006292378A JP 2006292378 A JP2006292378 A JP 2006292378A JP 2005109104 A JP2005109104 A JP 2005109104A JP 2005109104 A JP2005109104 A JP 2005109104A JP 2006292378 A JP2006292378 A JP 2006292378A
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ultrasonic
ultrasonic transducer
case
flow path
insulating material
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JP2005109104A
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Inventor
Tatsuo Fujimoto
龍雄 藤本
Mamoru Suzuki
守 鈴木
Kenichiro Yuasa
健一郎 湯浅
Yasuhiro Fujii
泰宏 藤井
Yukio Kimura
幸雄 木村
Toru Hiroyama
徹 廣山
Koji Hanamura
浩二 花村
Yukio Takahashi
幸夫 鷹箸
Yoshitomi Sameda
芳富 鮫田
Tatsuya Kimura
達也 木村
Shinya Hasebe
臣哉 長谷部
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Toshiba Corp
Osaka Gas Co Ltd
Tokyo Gas Co Ltd
Aichi Tokei Denki Co Ltd
Toho Gas Co Ltd
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Toshiba Corp
Osaka Gas Co Ltd
Tokyo Gas Co Ltd
Aichi Tokei Denki Co Ltd
Toho Gas Co Ltd
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Application filed by Toshiba Corp, Osaka Gas Co Ltd, Tokyo Gas Co Ltd, Aichi Tokei Denki Co Ltd, Toho Gas Co Ltd filed Critical Toshiba Corp
Priority to JP2005109104A priority Critical patent/JP2006292378A/en
Publication of JP2006292378A publication Critical patent/JP2006292378A/en
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Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic flowmeter capable of measuring a flow rate with high accuracy regardless of a temperature change. <P>SOLUTION: This flowmeter is equipped with a case 10 forming a passage 11 wherein fluid to be measured flows; a first ultrasonic vibrator 14 arranged on the upstream side inside the passage; a second ultrasonic vibrator 15 arranged oppositely to the first ultrasonic vibrator on the downstream side inside the passage; a control circuit 16 arranged outside the passage, for calculating the flow rate of the fluid to be measured flowing in the passage based on a propagation time of an ultrasonic wave transmitted/received between the first ultrasonic vibrator and the second ultrasonic vibrator; a signal wire 17 for connecting together the first ultrasonic vibrator and the second ultrasonic vibrator to the control circuit; and an insulating material 20 arranged in a hole 17 bored in the case, for holding the signal wire and securing insulation from the case. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、超音波を用いて流体の流量を計測する超音波流量計に関し、特に測定精度を向上させる技術に関する。   The present invention relates to an ultrasonic flowmeter that measures the flow rate of a fluid using ultrasonic waves, and more particularly to a technique for improving measurement accuracy.

従来、流体の流路の上流側と下流側に一定の距離をおいて一対の超音波振動子を配置し、制御回路の制御の下に、一対の超音波振動子の間で相互に超音波を繰り返して送受信し、上流側から下流側への超音波の伝播時間の積算値と、下流側から上流側への超音波の伝播時間の積算値との差に基づいて流体の流量を測定する超音波流量計が知られている。このような超音波流量計では、流路の中に配置された一対の超音波振動子と流路の外に配置された制御回路とは、流路を形成するケースに設けられた穴に中継端子を嵌め込み、この中継端子を経由する信号線により接続されている。   Conventionally, a pair of ultrasonic transducers are arranged at a certain distance on the upstream side and downstream side of a fluid flow path, and ultrasonic waves are mutually transmitted between the pair of ultrasonic transducers under the control of a control circuit. To measure the fluid flow rate based on the difference between the integrated value of the ultrasonic propagation time from the upstream side to the downstream side and the integrated value of the ultrasonic propagation time from the downstream side to the upstream side. Ultrasonic flow meters are known. In such an ultrasonic flowmeter, a pair of ultrasonic transducers arranged in the flow path and a control circuit arranged outside the flow path are relayed to a hole provided in a case forming the flow path. The terminals are fitted and connected by signal lines passing through the relay terminals.

また、上記超音波流量計に関連する技術として、開口穴での渦の低減と超音波送受信器から発信された超音波の不要成分の減衰促進により、超音波の送信波形のＳ／Ｎを高めて計測精度および流量計測できる上限値を高めることができる超音波流量計測装置が知られている（例えば、特許文献１参照）。   In addition, as a technology related to the ultrasonic flow meter, the S / N of the ultrasonic transmission waveform is increased by reducing the vortex in the opening hole and promoting the attenuation of unnecessary components of the ultrasonic wave transmitted from the ultrasonic transmitter / receiver. There is known an ultrasonic flow rate measuring device capable of increasing the measurement accuracy and the upper limit value for flow rate measurement (see, for example, Patent Document 1).

この超音波流量計測装置は、流体が流れる計測流路と、この計測流路の上流側および下流側に設けた超音波送受信器と、この超音波送受信器を計測流路に臨ませる上流側および下流側の開口穴と、開口穴の内面に配設した電気絶縁性を有する材料で形成した開口穴絶縁体と、開口穴に流入抑制体を備えている。   The ultrasonic flow rate measuring device includes a measurement channel through which a fluid flows, an ultrasonic transmitter / receiver provided upstream and downstream of the measurement channel, an upstream side where the ultrasonic transmitter / receiver faces the measurement channel, and An opening hole on the downstream side, an opening hole insulator formed of an electrically insulating material disposed on the inner surface of the opening hole, and an inflow suppressor are provided in the opening hole.

これにより、コンパクトな収納スペースでも開口穴絶縁体により超音波送受信器と開口穴を形成する流路体との間の導電距離を大きくし、落雷などにより取り付け側の流路体と超音波送受信器間に異常高電圧が発生した場合でもリークに至る耐電圧を高め、リーク電流による超音波送受信器の破損を防いで信頼性を向上することができる。
特開２００４−３７４６８号公報 As a result, even in a compact storage space, the conductive distance between the ultrasonic transmitter / receiver and the flow path body forming the open hole is increased by the opening hole insulator, and the flow path body and the ultrasonic transmitter / receiver on the attachment side are increased due to a lightning strike or the like. Even when an abnormally high voltage occurs in the meantime, the withstand voltage leading to leakage can be increased, and the ultrasonic transceiver can be prevented from being damaged by the leakage current, thereby improving the reliability.
JP 2004-37468 A

しかしながら、上述した従来の超音波流量計では、中継端子の部分での信号線とケースとの絶縁抵抗が温度などで変化することによりリーク電流が変化すると、一対の超音波振動子と制御回路との間で送受される信号の波形が歪み、またオフセット電圧が変化する。その結果、計測流量の値がばらつくという問題がある。   However, in the conventional ultrasonic flowmeter described above, when the leakage current changes due to the change in the insulation resistance between the signal line and the case at the relay terminal due to temperature or the like, a pair of ultrasonic transducers and a control circuit The waveform of the signal transmitted / received between is distorted and the offset voltage changes. As a result, there is a problem that the value of the measured flow rate varies.

本発明は、上述した問題を解消するためになされたものであり、その課題は、温度変化に拘わらず高い精度で流量を測定できる超音波流量計を提供することにある。   The present invention has been made to solve the above-described problems, and an object thereof is to provide an ultrasonic flowmeter capable of measuring a flow rate with high accuracy regardless of a temperature change.

上記課題を解決するために、本発明に係る超音波流量計は、被計測流体が流れる流路を形成するケースと、流路の内部の上流側に配置された第１超音波振動子と、流路の内部の下流側に第１超音波振動子と対向するように配置された第２超音波振動子と、流路の外部に配置され、第１超音波振動子と第２超音波振動子との間で送受される超音波の伝播時間に基づいて流路に流れる被計測流体の流量を算出する制御回路と、第１超音波振動子および第２超音波振動子と制御回路との間を接続する信号線と、ケースに穿たれた穴に配置され、信号線を保持しケースとの絶縁を確保する絶縁材とを備えることを特徴とする。   In order to solve the above-described problem, an ultrasonic flowmeter according to the present invention includes a case for forming a flow path through which a fluid to be measured flows, a first ultrasonic vibrator disposed on the upstream side of the flow path, A second ultrasonic transducer disposed on the downstream side of the flow channel so as to face the first ultrasonic transducer, and a first ultrasonic transducer and a second ultrasonic vibration disposed outside the flow channel. A control circuit for calculating a flow rate of a fluid to be measured flowing in a flow path based on a propagation time of ultrasonic waves transmitted to and received from a child, a first ultrasonic transducer, a second ultrasonic transducer, and a control circuit; It is characterized by comprising a signal line that connects the two and an insulating material that is disposed in a hole formed in the case and holds the signal line and ensures insulation from the case.

本発明に係る超音波流量計によれば、第１超音波振動子および第２超音波振動子と制御回路とを接続する信号線とケースとの間に、信号線を保持しケースとの絶縁を確保する絶縁材が配置されているので、信号線に流れる電流がケースへリークするのを抑制することができる。その結果、第１超音波振動子および第２超音波振動子と制御回路との間で送受される信号波形の歪みを抑えることができるので、流量の計測精度が劣化することを防止できる。   According to the ultrasonic flowmeter of the present invention, the signal line is held between the signal line connecting the first ultrasonic transducer and the second ultrasonic transducer and the control circuit and the case and insulated from the case. Since the insulating material for ensuring the resistance is arranged, it is possible to suppress the leakage of the current flowing through the signal line to the case. As a result, distortion of signal waveforms transmitted and received between the first ultrasonic transducer and the second ultrasonic transducer and the control circuit can be suppressed, so that deterioration in flow rate measurement accuracy can be prevented.

以下、本発明の実施例を、図面を参照しながら詳細に説明する。   Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

図１は、本発明の実施例１に係る超音波流量計の構造を示す側断面図である。この超音波流量計の内部には、ケース１０により、流体が流れる流路１１が形成されている。外部から供給された流体は、矢印で示すように、流入口１２から流路１１内に導入され、流路１１を通過して流出口１３から排出される。   FIG. 1 is a side sectional view showing the structure of the ultrasonic flowmeter according to the first embodiment of the present invention. A flow path 11 through which a fluid flows is formed by the case 10 inside the ultrasonic flowmeter. The fluid supplied from the outside is introduced into the flow path 11 from the inlet 12 as shown by the arrow, passes through the flow path 11 and is discharged from the outlet 13.

流路１１の上流側には第１超音波振動子１４が配置されている。また、流路１１の下流側には、所定距離をおいて第１超音波振動子１４に対向するように第２超音波振動子１５が配置されている。   A first ultrasonic transducer 14 is disposed on the upstream side of the flow path 11. Further, a second ultrasonic transducer 15 is disposed on the downstream side of the flow path 11 so as to face the first ultrasonic transducer 14 at a predetermined distance.

また、流路１１の外側には、制御回路１６が設けられている。この制御回路１６と、第１超音波振動子１４および第２超音波振動子１５との間は、ケース１０に穿たれた穴１７に配置された中継端子１８を経由する信号線１９により接続されている。また、穴１７は、中継端子１８の絶縁材２０により塞がれており、流路１１の気密を保つようになっている。絶縁材２０は、信号線１９を保持し、ケース１０との絶縁を確保するように構成されている。絶縁材２０としては、体積抵抗率が１×１０15（Ω−ｃｍ）以上の高抵抗の材料、例えば体積抵抗率が１×１０18（Ω−ｃｍ）を有するテフロン（登録商標）材で構成することができる。なお、絶縁材２０としては、テフロン（登録商標）材に限らず、例えば、体積抵抗率が１×１０15（Ω−ｃｍ）のシリコン材を用いることができる。 A control circuit 16 is provided outside the flow path 11. The control circuit 16 is connected to the first ultrasonic transducer 14 and the second ultrasonic transducer 15 by a signal line 19 via a relay terminal 18 arranged in a hole 17 formed in the case 10. ing. The hole 17 is closed by the insulating material 20 of the relay terminal 18 so that the air flow path 11 is kept airtight. The insulating material 20 is configured to hold the signal line 19 and ensure insulation from the case 10. The insulating material 20 is made of a high-resistance material having a volume resistivity of 1 × 10 15 (Ω-cm) or more, for example, a Teflon (registered trademark) material having a volume resistivity of 1 × 10 18 (Ω-cm). can do. The insulating material 20 is not limited to a Teflon (registered trademark) material, and for example, a silicon material having a volume resistivity of 1 × 10 15 (Ω-cm) can be used.

上記の構成において、第１超音波振動子１４は、制御回路１６から送られてくる駆動パルス信号に応じて超音波を発生し、第２超音波振動子１５に向けて送信する。また、第１超音波振動子１４は、第２超音波振動子１５からの超音波を受信して電気信号に変換し、制御回路１６に送る。第２超音波振動子１５は、制御回路１６から送られてくる駆動パルス信号に応じて超音波を発生し、第１超音波振動子１４に向けて送信する。また、第２超音波振動子１５は、第１超音波振動子１４からの超音波を受信して電気信号に変換し、制御回路１６に送る。   In the above configuration, the first ultrasonic transducer 14 generates an ultrasonic wave according to the drive pulse signal sent from the control circuit 16 and transmits the ultrasonic wave toward the second ultrasonic transducer 15. Further, the first ultrasonic transducer 14 receives the ultrasonic wave from the second ultrasonic transducer 15, converts it into an electrical signal, and sends it to the control circuit 16. The second ultrasonic transducer 15 generates an ultrasonic wave according to the drive pulse signal sent from the control circuit 16 and transmits the ultrasonic wave toward the first ultrasonic transducer 14. The second ultrasonic transducer 15 receives the ultrasonic wave from the first ultrasonic transducer 14, converts it into an electrical signal, and sends it to the control circuit 16.

制御回路１６は、例えばマイクロコンピュータを含み、第１超音波振動子１４または第２超音波振動子１５に駆動パルス信号を送って超音波を発生させるとともに、この超音波を受信した第１超音波振動子１４または第２超音波振動子１５から送られてくる受信信号に基づき、第１超音波振動子１４から第２超音波振動子１５への超音波の伝播時間（順方向伝播時間）と第２超音波振動子１５から第１超音波振動子１４へ超音波の伝播時間（逆方向伝播時間）とを算出する。そして、これら算出した超音波の順方向伝播時間と逆方向伝播時間との差に基づいて流体の流速を算出し、算出した流速に流路１１の断面積を乗じて体積流量を求める。求められた体積流量が、測定された流体の流量として外部に出力される。   The control circuit 16 includes, for example, a microcomputer, sends a drive pulse signal to the first ultrasonic transducer 14 or the second ultrasonic transducer 15 to generate an ultrasonic wave, and receives the first ultrasonic wave. Based on the received signal sent from the transducer 14 or the second ultrasonic transducer 15, the propagation time (forward propagation time) of the ultrasonic wave from the first ultrasonic transducer 14 to the second ultrasonic transducer 15, and The propagation time of ultrasonic waves (reverse propagation time) from the second ultrasonic transducer 15 to the first ultrasonic transducer 14 is calculated. Then, the flow velocity of the fluid is calculated based on the difference between the calculated forward propagation time and backward propagation time of the ultrasonic wave, and the volume flow rate is obtained by multiplying the calculated flow velocity by the cross-sectional area of the flow path 11. The obtained volume flow rate is output to the outside as the measured fluid flow rate.

以上のように構成される本発明の実施例１に係る超音波流量計によれば、ケース１０に穿たれた穴１７に配置された中継端子１８の周囲は、高抵抗の絶縁材２０で覆われているので、温度変化があっても中継端子１８及び信号線１７に流れる信号電流がケース１０へリークするのを抑制することができる。   According to the ultrasonic flowmeter according to the first embodiment of the present invention configured as described above, the periphery of the relay terminal 18 disposed in the hole 17 formed in the case 10 is covered with the high-resistance insulating material 20. Therefore, even if there is a temperature change, it is possible to prevent the signal current flowing through the relay terminal 18 and the signal line 17 from leaking to the case 10.

その結果、第１超音波振動子１４および第２超音波振動子１５と制御回路１６との間で送受される信号波形の歪みを抑えることができるので、流量の計測精度が劣化することを防止できる。   As a result, distortion of signal waveforms transmitted and received between the first ultrasonic transducer 14 and the second ultrasonic transducer 15 and the control circuit 16 can be suppressed, so that deterioration in flow rate measurement accuracy is prevented. it can.

本発明の実施例２に係る超音波流量計は、実施例１に係る超音波流量計おける信号線の代わりに同軸線を用いたものである。なお、以下においては、実施例１に係る超音波流量計の構造と同一または相当部分には実施例１と同一の符号を付して説明を省略または簡単化する。   The ultrasonic flowmeter according to the second embodiment of the present invention uses a coaxial line instead of the signal line in the ultrasonic flowmeter according to the first embodiment. In the following, the same or corresponding parts as the structure of the ultrasonic flowmeter according to the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description thereof is omitted or simplified.

図２は、本発明の実施例２に係る超音波流量計の構造を示す側断面図である。この超音波流量計は、図１に示した実施例１に係る超音波流量計の中継端子１８および信号線１９の代わりに同軸線２１を用いて、第１超音波振動子１４および第２超音波振動子１５と制御回路１６とが接続されている。同軸線２１は、２本の信号線を絶縁材で被覆することにより構成されている。   FIG. 2 is a side sectional view showing the structure of the ultrasonic flowmeter according to the second embodiment of the present invention. This ultrasonic flowmeter uses the coaxial line 21 instead of the relay terminal 18 and the signal line 19 of the ultrasonic flowmeter according to the first embodiment shown in FIG. The sound wave vibrator 15 and the control circuit 16 are connected. The coaxial line 21 is configured by covering two signal lines with an insulating material.

また、ケース１０に穿たれた穴１７を通過する同軸線２１の周囲は、充填材２２で塞がれて構成されている。これにより、流路１１の気密性を保つことができる。充填材２２としては、シリコン材、テフロン（登録商標）材、軟質のゴム、エポキシ樹脂などを用いることができる。   Further, the periphery of the coaxial line 21 passing through the hole 17 formed in the case 10 is configured to be closed with a filler 22. Thereby, the airtightness of the flow path 11 can be maintained. As the filler 22, silicon material, Teflon (registered trademark) material, soft rubber, epoxy resin, or the like can be used.

以上のように構成される本発明の実施例２に係る超音波流量計によれば、第１超音波振動子１４および第２超音波振動子１５と制御回路１６との接続に同軸線２１を用いたので中継端子が不要になるとともに、同軸線２１自体が信号線を絶縁材で被覆することにより構成されているので、信号線とケース１０との間の絶縁性を保つことができる。   According to the ultrasonic flowmeter according to the second embodiment of the present invention configured as described above, the coaxial line 21 is connected to the connection between the first ultrasonic transducer 14 and the second ultrasonic transducer 15 and the control circuit 16. Since it is used, the relay terminal becomes unnecessary, and the coaxial line 21 itself is configured by covering the signal line with an insulating material, so that the insulation between the signal line and the case 10 can be maintained.

本発明の実施例３に係る超音波流量計は、一対の超音波振動子をケースに取り付けたものである。なお、以下においては、実施例１に係る超音波流量計の構造と同一または相当部分には実施例１と同一の符号を付して説明を省略または簡単化する。   The ultrasonic flowmeter according to the third embodiment of the present invention has a pair of ultrasonic transducers attached to a case. In the following, the same or corresponding parts as the structure of the ultrasonic flowmeter according to the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description thereof is omitted or simplified.

図３は、本発明の実施例３に係る超音波流量計の構造を示す側断面図である。この超音波流量計においては、第１超音波振動子１４は、流路１１の上流側のケース１０の内側壁に取り付けられており、その信号端子３０は、ケース１０の外側壁から外部に露出するように導かれている。この第１超音波振動子１４の信号端子３０は、流路１１の外部において信号線１９により制御回路１６に接続されている。   FIG. 3 is a side sectional view showing the structure of the ultrasonic flowmeter according to the third embodiment of the present invention. In this ultrasonic flow meter, the first ultrasonic transducer 14 is attached to the inner wall of the case 10 upstream of the flow path 11, and its signal terminal 30 is exposed to the outside from the outer wall of the case 10. Is guided to do. The signal terminal 30 of the first ultrasonic transducer 14 is connected to the control circuit 16 by a signal line 19 outside the flow path 11.

また、第２超音波振動子１５は、流路１１の下流側のケース１０の内側壁に、第１超音波振動子１４に対向するように取り付けられており、その信号端子３０は、ケース１０の外側壁から外部に露出するように導かれている。この第２超音波振動子１５の信号端子３０は、流路１１の外部において信号線１９により制御回路１６に接続されている。   The second ultrasonic transducer 15 is attached to the inner wall of the case 10 on the downstream side of the flow path 11 so as to face the first ultrasonic transducer 14, and the signal terminal 30 is connected to the case 10. It is led to be exposed to the outside from the outer wall. The signal terminal 30 of the second ultrasonic transducer 15 is connected to the control circuit 16 by a signal line 19 outside the flow path 11.

図４は、第１超音波振動子１４の取り付け状態を拡大して示す図であり、図４（ａ）は平面図、図４（ｂ）は側断面図である。第１超音波振動子１４は、その信号端子３０がケース１０に穿たれた穴２３を介してケース１０の外部に露出されるようにして、絶縁性Ｏリング３１を介在させてケース１０の内側壁に取り付けられている。   FIGS. 4A and 4B are enlarged views showing a state where the first ultrasonic transducer 14 is attached. FIG. 4A is a plan view and FIG. 4B is a side sectional view. The first ultrasonic transducer 14 is exposed to the inside of the case 10 with an insulating O-ring 31 interposed so that the signal terminal 30 is exposed to the outside of the case 10 through the hole 23 formed in the case 10. Attached to the wall.

より詳しくは、ケース１０の内側壁に絶縁性Ｏリング３１を介在させて第１超音波振動子１４の本体が載置され、この本体の鍔部１４ａをＯリング３２により押圧するようにして留めネジ３３によりケース１０にネジ止めされている。第２超音波振動子１５の取り付けも同様の方法で行われている。絶縁性Ｏリング３１は、高抵抗、例えば体積抵抗率が１×１０15（Ω−ｃｍ）を有するテフロン（登録商標）材またはシリコン材をドーナツ状に成型して作製することができる。 More specifically, the main body of the first ultrasonic transducer 14 is placed on the inner wall of the case 10 with an insulating O-ring 31 interposed therebetween, and the flange 14 a of the main body is pressed by the O-ring 32 so as to be fastened. Screwed to the case 10 by screws 33. The second ultrasonic transducer 15 is attached in the same manner. The insulating O-ring 31 can be produced by molding a Teflon (registered trademark) material or silicon material having a high resistance, for example, a volume resistivity of 1 × 10 15 (Ω-cm) into a donut shape.

以上のように構成される本発明の実施例３に係る超音波流量計によれば、第１超音波振動子１４および第２超音波振動子１５の信号端子３０からの信号線１９を、流路１１の内部に配線することなく（流路１１の外部を通過するようにして）、制御回路１６に接続したので、温度変化があっても信号端子３０に流れる信号電流がケース１０へリークするのを抑制することができる。   According to the ultrasonic flowmeter of the third embodiment of the present invention configured as described above, the signal line 19 from the signal terminal 30 of the first ultrasonic transducer 14 and the second ultrasonic transducer 15 is connected to the flowmeter. Since it is connected to the control circuit 16 without wiring inside the path 11 (so as to pass through the outside of the flow path 11), the signal current flowing through the signal terminal 30 leaks to the case 10 even if the temperature changes. Can be suppressed.

その結果、第１超音波振動子１４および第２超音波振動子１５と制御回路１６との間で送受される信号波形の歪みを抑えることができるので、流量の計測精度が劣化することを防止できる。   As a result, distortion of signal waveforms transmitted and received between the first ultrasonic transducer 14 and the second ultrasonic transducer 15 and the control circuit 16 can be suppressed, so that deterioration in flow rate measurement accuracy is prevented. it can.

なお、実施例３に係る超音波流量計では、第１超音波振動子１４および第２超音波振動子１５のケース１０への取り付けを、絶縁性Ｏリング３１を介在させてネジ止めにより行うように構成したが、第１超音波振動子１４および第２超音波振動子１５は、その本体と熱膨張係数が同一の接着剤を用いてケース１０に取り付けるように構成することもできる。この場合、絶縁性Ｏリング３１、Ｏリング３２および留めネジ３３は不要になるので、超音波流量計を安価に構成できる。また、ネジ止め作業を行う必要がないので、組み立て作業が簡単になり、製造コストを下げることができる。   In the ultrasonic flowmeter according to the third embodiment, the first ultrasonic transducer 14 and the second ultrasonic transducer 15 are attached to the case 10 by screwing with an insulating O-ring 31 interposed. However, the first ultrasonic transducer 14 and the second ultrasonic transducer 15 may be configured to be attached to the case 10 using an adhesive having the same thermal expansion coefficient as that of the main body. In this case, since the insulating O-ring 31, the O-ring 32, and the retaining screw 33 are unnecessary, the ultrasonic flowmeter can be configured at low cost. Further, since it is not necessary to perform a screwing operation, the assembling operation is simplified and the manufacturing cost can be reduced.

本発明の実施例４に係る超音波流量計は、実施例１に係る超音波流量計において、信号線とケースとの間のリーク電流を監視するようにしたものである。   The ultrasonic flowmeter according to the fourth embodiment of the present invention monitors the leakage current between the signal line and the case in the ultrasonic flowmeter according to the first embodiment.

図５は、本発明の実施例４に係る超音波流量計の構成を示す図である。この超音波流量計は、図１に示した実施例１に係る超音波流量計に、リーク電流監視回路４０が追加されて構成されている。   FIG. 5 is a diagram illustrating a configuration of an ultrasonic flowmeter according to the fourth embodiment of the present invention. This ultrasonic flow meter is configured by adding a leakage current monitoring circuit 40 to the ultrasonic flow meter according to the first embodiment shown in FIG.

リーク電流監視回路４０は、ケース１０と絶縁材２０とに接続され、これら間の抵抗値を計測する。具体的には、リーク電流監視回路４０は、定期的にケース１０と絶縁材２０との間に電圧を印加し、電圧印加時にケース１０と絶縁材２０との間に流れるリーク電流を計測する。そして、計測されたリーク電流値を所定の基準値と比較し、リーク電流値が基準値以上になった場合に、ケース１０と中継端子１８（信号線１９）との間の抵抗値が所定値以下になったものとみなし、その旨を外部に通知する。   The leakage current monitoring circuit 40 is connected to the case 10 and the insulating material 20 and measures a resistance value therebetween. Specifically, the leakage current monitoring circuit 40 periodically applies a voltage between the case 10 and the insulating material 20 and measures a leakage current flowing between the case 10 and the insulating material 20 when the voltage is applied. Then, the measured leakage current value is compared with a predetermined reference value, and when the leakage current value is equal to or higher than the reference value, the resistance value between the case 10 and the relay terminal 18 (signal line 19) is a predetermined value. It is assumed that the following has occurred, and this is notified to the outside.

以上のように構成される本発明の実施例４に係る超音波流量計によれば、ケース１０と絶縁材２０との間の抵抗値が所定値以下になった場合に外部に通知されるので、経年変化等により絶縁材２０の絶縁特性が劣化したことを知ることができ、必要に応じて絶縁材２０を交換することができる。   According to the ultrasonic flowmeter according to the fourth embodiment of the present invention configured as described above, when the resistance value between the case 10 and the insulating material 20 becomes a predetermined value or less, it is notified to the outside. It is possible to know that the insulating properties of the insulating material 20 have deteriorated due to aging, etc., and the insulating material 20 can be replaced as necessary.

従って、第１超音波振動子１４および第２超音波振動子１５と制御回路１６との間で送受される信号波形の歪みを常に正常に保つことができるので、流量の計測精度が劣化することを防止できる。   Accordingly, the distortion of the signal waveform transmitted and received between the first ultrasonic transducer 14 and the second ultrasonic transducer 15 and the control circuit 16 can always be kept normal, so that the measurement accuracy of the flow rate is deteriorated. Can be prevented.

本発明は、超音波ガスメータ等に適用可能である。   The present invention is applicable to an ultrasonic gas meter or the like.

本発明の実施例１に係る超音波流量計の構造を示す側断面図である。It is a sectional side view which shows the structure of the ultrasonic flowmeter which concerns on Example 1 of this invention. 本発明の実施例２に係る超音波流量計の構造を示す側断面図である。It is a sectional side view which shows the structure of the ultrasonic flowmeter which concerns on Example 2 of this invention. 本発明の実施例３に係る超音波流量計の構造を示す側断面図である。It is a sectional side view which shows the structure of the ultrasonic flowmeter which concerns on Example 3 of this invention. 本発明の実施例３に係る超音波流量計における第１超音波振動子の取り付け状態を拡大して示す図である。It is a figure which expands and shows the attachment state of the 1st ultrasonic transducer | vibrator in the ultrasonic flowmeter which concerns on Example 3 of this invention. 本発明の実施例４に係る超音波流量計の構成を示す図である。It is a figure which shows the structure of the ultrasonic flowmeter which concerns on Example 4 of this invention.

符号の説明Explanation of symbols

１０ ケース
１１ 流路
１２ 流入口
１３ 流出口
１４ 第１超音波振動子
１４ａ 鍔部
１５ 第２超音波振動子
１６ 制御回路
１７ 穴
１８ 中継端子
１９ 信号線
２０ 絶縁材
２１ 同軸線
２２ 充填材
２３ 穴
３０ 信号端子
３１ 絶縁性Ｏリング
３２ Ｏリング
３３ 留めネジ
４０ リーク電流監視回路 DESCRIPTION OF SYMBOLS 10 Case 11 Flow path 12 Inlet 13 Outlet 14 1st ultrasonic transducer | vibrator 14a The collar part 15 The 2nd ultrasonic transducer | vibrator 16 Control circuit 17 Hole 18 Relay terminal 19 Signal line 20 Insulation material 21 Coaxial line 22 Filler material 23 Hole 30 Signal terminal 31 Insulating O-ring 32 O-ring 33 Set screw 40 Leakage current monitoring circuit

Claims (9)

被計測流体が流れる流路を形成するケースと、
前記流路の内部の上流側に配置された第１超音波振動子と、
前記流路の内部の下流側に前記第１超音波振動子と対向するように配置された第２超音波振動子と、
前記流路の外部に配置され、前記第１超音波振動子と前記第２超音波振動子との間で送受される超音波の伝播時間に基づいて前記流路に流れる被計測流体の流量を算出する制御回路と、
前記第１超音波振動子および第２超音波振動子と前記制御回路との間を接続する信号線と、
前記ケースに穿たれた穴に配置され、前記信号線を保持し前記ケースとの絶縁を確保する絶縁材と、
を備えることを特徴とする超音波流量計。 A case forming a flow path through which the fluid to be measured flows;
A first ultrasonic transducer disposed on the upstream side of the flow path;
A second ultrasonic transducer disposed on the downstream side of the flow path so as to face the first ultrasonic transducer;
The flow rate of the fluid to be measured that flows in the flow path based on the propagation time of the ultrasonic wave that is arranged outside the flow path and is transmitted and received between the first ultrasonic transducer and the second ultrasonic transducer. A control circuit to calculate,
A signal line connecting between the first ultrasonic transducer and the second ultrasonic transducer and the control circuit;
An insulating material that is disposed in a hole formed in the case and holds the signal line and secures insulation from the case;
An ultrasonic flowmeter comprising: 前記絶縁材は、温度変化による前記ケースへのリーク電流を抑制することを特徴とする請求項１記載の超音波流量計。   The ultrasonic flowmeter according to claim 1, wherein the insulating material suppresses a leakage current to the case due to a temperature change. 前記絶縁材は、テフロン（登録商標）材から成ることを特徴とする請求項１記載の超音波流量計。   The ultrasonic flowmeter according to claim 1, wherein the insulating material is made of a Teflon (registered trademark) material. 前記絶縁材は、シリコン材から成ることを特徴とする請求項１記載の超音波流量計。   The ultrasonic flowmeter according to claim 1, wherein the insulating material is made of a silicon material. 前記信号線は、同軸線から成ることを特徴とする請求項１記載の超音波流量計。   The ultrasonic flowmeter according to claim 1, wherein the signal line is a coaxial line. 前記絶縁材は、前記温度変化による前記ケースへのリーク電流を抑制する充填材から成ることを特徴とする請求項５記載の超音波流量計。   The ultrasonic flowmeter according to claim 5, wherein the insulating material is made of a filler that suppresses a leakage current to the case due to the temperature change. 被計測流体が流れる流路を形成するケースと、
前記流路の内部の上流側に配置され且つ前記ケースの内側壁に、第１信号端子が前記流路の外部に露出するように取り付けられた第１超音波振動子と、
前記流路の内部の下流側に前記第１超音波振動子と対向するように配置され且つ前記ケースの内側壁に、第２信号端子が前記流路の外部に露出するように取り付けられた第２超音波振動子と、
前記流路の外部に配置され、前記第１超音波振動子と前記第２超音波振動子との間で送受される超音波の伝播時間に基づいて前記流路に流れる被計測流体の流量を算出する制御回路と、
前記流路の外部を通過して、前記第１超音波振動子および第２超音波振動子の各信号端子と前記制御回路との間を接続する信号線と、
前記各超音波振動子毎に設けられ、前記超音波振動子と前記ケースの内側壁との間に配置された絶縁材と、
を備えることを特徴とする超音波流量計。 A case forming a flow path through which the fluid to be measured flows;
A first ultrasonic transducer disposed upstream of the flow path and attached to an inner wall of the case so that a first signal terminal is exposed to the outside of the flow path;
A second signal terminal is disposed on the downstream side of the flow path so as to face the first ultrasonic transducer and is attached to an inner wall of the case so as to be exposed to the outside of the flow path. 2 ultrasonic transducers,
The flow rate of the fluid to be measured that flows in the flow path based on the propagation time of the ultrasonic wave that is arranged outside the flow path and is transmitted and received between the first ultrasonic transducer and the second ultrasonic transducer. A control circuit to calculate,
A signal line that passes through the outside of the flow path and connects between the signal terminals of the first ultrasonic transducer and the second ultrasonic transducer and the control circuit;
An insulating material provided for each of the ultrasonic transducers and disposed between the ultrasonic transducer and an inner wall of the case;
An ultrasonic flowmeter comprising: 前記第１超音波振動子および第２超音波振動子の各々は、前記絶縁材を介在させてネジ止めにより、または前記絶縁材を介在させないで接着剤により前記ケースの内側壁に取付けられていることを特徴とする請求項７記載の超音波流量計。   Each of the first ultrasonic transducer and the second ultrasonic transducer is attached to the inner wall of the case by screws with the insulating material interposed, or by an adhesive without interposing the insulating material. The ultrasonic flowmeter according to claim 7. 前記信号線と前記ケースとの間とのリーク電流を監視するリーク電流監視回路を備えることを特徴とする請求項１記載の超音波流量計。   The ultrasonic flowmeter according to claim 1, further comprising a leakage current monitoring circuit that monitors a leakage current between the signal line and the case.
JP2005109104A 2005-04-05 2005-04-05 Ultrasonic flowmeter Pending JP2006292378A (en)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51124460A (en) * 1975-04-23 1976-10-29 Yokogawa Hokushin Electric Corp Ultrasonic-wave vibrator equipping method and device
JPS59215685A (en) * 1983-05-23 1984-12-05 日本電気ホームエレクトロニクス株式会社 Method of producing airtight terminal with rubber
JPH029831A (en) * 1988-06-28 1990-01-12 Kawasaki Steel Corp Purification of alkylbenzene oligomer mixture
JP2003339092A (en) * 2002-05-20 2003-11-28 Murata Mfg Co Ltd Ultrasonic wave sensor, and ultrasonic wave flowmeter employing the same
JP2004037468A (en) * 2001-10-31 2004-02-05 Matsushita Electric Ind Co Ltd Ultrasonic flowmeter
JP2004127712A (en) * 2002-10-02 2004-04-22 Matsushita Electric Ind Co Ltd Gas-blast circuit-breaker
JP2004151090A (en) * 2002-10-07 2004-05-27 Aichi Tokei Denki Co Ltd Gas flow meter and airtight terminal

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51124460A (en) * 1975-04-23 1976-10-29 Yokogawa Hokushin Electric Corp Ultrasonic-wave vibrator equipping method and device
JPS59215685A (en) * 1983-05-23 1984-12-05 日本電気ホームエレクトロニクス株式会社 Method of producing airtight terminal with rubber
JPH029831A (en) * 1988-06-28 1990-01-12 Kawasaki Steel Corp Purification of alkylbenzene oligomer mixture
JP2004037468A (en) * 2001-10-31 2004-02-05 Matsushita Electric Ind Co Ltd Ultrasonic flowmeter
JP2003339092A (en) * 2002-05-20 2003-11-28 Murata Mfg Co Ltd Ultrasonic wave sensor, and ultrasonic wave flowmeter employing the same
JP2004127712A (en) * 2002-10-02 2004-04-22 Matsushita Electric Ind Co Ltd Gas-blast circuit-breaker
JP2004151090A (en) * 2002-10-07 2004-05-27 Aichi Tokei Denki Co Ltd Gas flow meter and airtight terminal

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