JP2008014676A

JP2008014676A - Tension of belt measurement method, and tension of belt measurement device

Info

Publication number: JP2008014676A
Application number: JP2006183774A
Authority: JP
Inventors: Yasuhiro Hashimoto; 康弘橋本
Original assignee: Mitsuboshi Belting Ltd
Current assignee: Mitsuboshi Belting Ltd
Priority date: 2006-07-03
Filing date: 2006-07-03
Publication date: 2008-01-24

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tension of belt measurement method capable of correctly measurement the tension of a belt, without changing the running condition and of measurement of the tension of the belt in noncontact condition, while making the belt run and drive, while hanging the belt on the pulley. <P>SOLUTION: A front reflection mark 3 and A rear reflection mark 4 are provided on the belt 1, and a front optical sensor 5 and a rear optical sensor 6 are arranged along the belt 1. At the reference test i.e. wherein a tension is T<SB>0</SB>, is performed no-load to the belt 1, a time t<SB>A0</SB>and a time t<SB>B0</SB>are measured, based on the detections by the front reflection mark 3 and the rear reflection mark 4 by the front optical sensor 5 and the rear optical sensor 6. At the measurement test in which the belt 1 is made to run with a tension T, time t<SB>A1</SB>and time T<SB>B1</SB>are measured, based on the detection of the front reflection mark 3 and the rear reflection mark 4 due to the front optical sensor 5 and the rear optical sensor 6. The tension T of the belt 1 is obtained by the Equation: T=T<SB>0</SB>+K[(t<SB>A1</SB>×t<SB>B0</SB>)/(t<SB>B1</SB>×t<SB>A0</SB>)-1], where K is the intrinsic constant of the belt. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、ベルトをプーリに懸架して走行駆動させながら、ベルトの張力を測定する方法及び測定装置に関するものである。 The present invention relates to a method and a measuring device for measuring the tension of a belt while suspending and driving the belt on a pulley.

プーリに懸架したベルトの張力を測定する方法として、走行を停止した状態でベルトの張力を測定する場合には、特許文献１などで各種の方法が提案されているが、走行停止状態と、荷重が負荷された従動プーリに動力を伝達する走行状態とではベルトの張力は異なるので、実機で走行駆動している状態でのベルトの張力を知るには、プーリでベルトを走行駆動させながら張力を測定することが必要である。 As a method of measuring the tension of the belt suspended on the pulley, various methods have been proposed in Patent Document 1 or the like when measuring the tension of the belt while the traveling is stopped. Since the belt tension is different from the traveling state where power is transmitted to the driven pulley loaded with the belt, the tension of the belt while traveling with the pulley can be determined in order to know the belt tension when traveling with the actual machine. It is necessary to measure.

一方、特許文献２には、ベルトの張力に応じて走行時の振動が変化することに着目し、ベルトの振動を光学的に検出して、ベルトの張力を算出する方法が提案されている。この方法ではベルトを走行駆動させながら張力を測定することが可能であるが、ベルトの振動は、ベルトの固有振動だけでなく、クランク軸の回転変動に伴う張力変動によって振動が発生する他、その他の振動も入ってくるので、張力を正確に測定することは困難であり、実用的であるとはいえない。 On the other hand, Patent Document 2 proposes a method of calculating the belt tension by optically detecting the vibration of the belt, focusing on the fact that the vibration during running changes according to the tension of the belt. In this method, it is possible to measure the tension while driving the belt. However, the vibration of the belt is not only due to the natural vibration of the belt, but also due to the fluctuation of the tension caused by the fluctuation of the rotation of the crankshaft. Therefore, it is difficult to accurately measure the tension, which is not practical.

そこでベルトを走行駆動させながら張力を測定する方法として、従来から図４に示すような軸荷重測定法が一般に行なわれている。すなわち、図４（ｂ）のように歪ゲージ１５を貼った軸１６の先端に張力測定用プーリ１７を設け、図４（ａ）のようにプーリ２間に懸架したベルト１にこの張力測定用プーリ１７を押し当てて、角度θでベルト１を屈曲させた状態で、ベルト１を走行駆動させるようにしたものである。そしてベルト１を走行駆動させた際の歪ゲージ１５の出力から軸荷重Ｆを計測し、次の式からベルト１の張力Ｔを求めることができるものである。 Therefore, as a method of measuring the tension while driving the belt, a shaft load measuring method as shown in FIG. 4 has been conventionally performed. That is, a tension measuring pulley 17 is provided at the tip of a shaft 16 to which a strain gauge 15 is attached as shown in FIG. 4B, and this tension measuring pulley 1 is suspended between the pulleys 2 as shown in FIG. The belt 1 is driven to run in a state where the pulley 17 is pressed and the belt 1 is bent at an angle θ. The axial load F is measured from the output of the strain gauge 15 when the belt 1 is driven to travel, and the tension T of the belt 1 can be obtained from the following equation.

Ｔ＝Ｆ／２ｃｏｓθ
特開平１１−３０５５８号公報特開２００２−２６７５５６号公報 T = F / 2 cos θ
Japanese Patent Laid-Open No. 11-30558 JP 2002-267556 A

しかし、張力測定用プーリ１７を設ける位置に、本来アイドラプーリがない駆動系の場合、張力測定用プーリ１７を用いてベルトをθの角度で屈曲させると、プーリ２に対するベルト１の巻き付き角が変わることになって、伝達力が変化することになり、またベルト１のスパン長も変わって、ベルト１の振動形態が変化することになる。従ってこのようにベルト１の走行状態が変化するので、正確な張力を測定することが難しいという問題があった。またプーリ２間に張力測定用プーリ１７を配置しなければならないために、プーリ２の軸間距離が短い場合は測定が困難であり、さらにベルト１が使用される対象機械やエンジンに合った軸をその度に作製しなければならないという問題もあった。 However, in the case of a drive system that originally does not have an idler pulley at the position where the tension measurement pulley 17 is provided, if the belt is bent at an angle θ using the tension measurement pulley 17, the winding angle of the belt 1 with respect to the pulley 2 changes. As a result, the transmission force changes, the span length of the belt 1 also changes, and the vibration form of the belt 1 changes. Therefore, since the running state of the belt 1 changes in this way, there is a problem that it is difficult to measure an accurate tension. In addition, since the tension measuring pulley 17 must be disposed between the pulleys 2, the measurement is difficult when the distance between the pulleys 2 is short, and the shaft suitable for the target machine or engine in which the belt 1 is used. There was also a problem that it had to be produced each time.

本発明は上記の点に鑑みてなされたものであり、ベルトをプーリに懸架して走行駆動させながら、ベルトの張力を非接触で測定することができ、ベルトの走行状態を変化させることなく正確に張力を測定することができるベルトの張力測定方法及び張力測定装置を提供することを目的とするものである。 The present invention has been made in view of the above points. The belt tension can be measured in a non-contact manner while the belt is suspended and driven by a pulley, and the belt traveling state can be accurately measured without changing. It is an object of the present invention to provide a belt tension measuring method and tension measuring apparatus capable of measuring tension.

本発明の請求項１に係るベルトの張力測定方法は、測定対象となるベルト１をプーリ２に懸架して走行駆動した際に、このベルト１に作用する張力Ｔを測定する方法であって、
ベルト１の表面にその走行方向での前後２箇所において前反射マーク３と後反射マーク４とを設けると共に、ベルト１に沿ってその走行方向での前後２箇所において、前反射マーク３の通過を検知する前光センサ５と前反射マーク３及び後反射マーク４の通過を検知する後光センサ６とを配置して設け、
張力Ｔ_０に設定して無負荷でベルト１を走行させたときにおいて、前反射マーク３が通過したことを後光センサ６が検知した後に後反射マーク４が通過したことを後光センサ６が検知するまでの時間ｔ_Ａ０を計測すると共に、後光センサ６で前反射マーク３が通過したことを検知した後にこの前反射マーク３が通過したことを前光センサ５が検知するまでの時間ｔ_Ｂ０を計測し、
測定する張力Ｔでベルト１を走行させたときにおいて、前反射マーク３が通過したことを後光センサ６が検知した後に後反射マーク４が通過したことを後光センサ６が検知するまでの時間ｔ_Ａ１を計測すると共に、後光センサ６で前反射マーク３が通過したことを検知した後にこの前反射マーク３が通過したことを前光センサ５が検知するまでの時間ｔ_Ｂ１を計測し、
Ｔ＝Ｔ_０＋Ｋ［（ｔ_Ａ１・ｔ_Ｂ０）／（ｔ_Ｂ１・ｔ_Ａ０）−１］
（Ｋはベルト固有の定数）
の式から張力Ｔを求めることを特徴とするものである。 The belt tension measuring method according to claim 1 of the present invention is a method for measuring the tension T acting on the belt 1 when the belt 1 to be measured is suspended and driven by the pulley 2,
The front reflection mark 3 and the rear reflection mark 4 are provided on the surface of the belt 1 at two front and rear positions in the traveling direction, and the front reflection mark 3 is passed along the belt 1 at two front and rear positions in the traveling direction. The front light sensor 5 to detect and the rear light sensor 6 to detect the passage of the front reflection mark 3 and the rear reflection mark 4 are arranged and provided,
When the belt 1 is run with no load set to the tension T ₀ , the rear light sensor 6 indicates that the rear reflection mark 4 has passed after the rear light sensor 6 detects that the front reflection mark 3 has passed. The time t _A0 until detection is measured, and the time t until the front light sensor 5 detects that the front reflection mark 3 has passed after the rear light sensor 6 detects that the front reflection mark 3 has passed. Measure _B0 ,
Time until the rear light sensor 6 detects that the rear reflection mark 4 has passed after the rear light sensor 6 has detected that the front reflection mark 3 has passed when the belt 1 is run with the tension T to be measured. t _A1 is measured, and the time t _B1 until the front light sensor 5 detects that the front reflection mark 3 has passed after the rear light sensor 6 detects that the front reflection mark 3 has passed is measured.
T = T ₀ + K [(t _A1 · t _B0 ) / (t _B1 · t _A0 ) −1]
(K is a constant specific to the belt)
This is characterized in that the tension T is obtained from the following equation.

本発明の請求項２に係るベルトの張力測定装置は、測定対象となるベルト１を懸架して走行駆動するプーリ２と、
このベルト１にその走行方向での前後２箇所において設けられる前反射マーク３及び後反射マーク４と、
ベルト１に沿ってその走行方向での前後２箇所において設けられる、前反射マーク３の通過を検知する前光センサ５及び前反射マーク３と後反射マーク４の通過を検知する後光センサ６と、
前反射マーク３が通過したことを後光センサ６が検知した後に後反射マーク４が通過したことを後光センサ６が検知するまでの時間を計測し、且つ、後光センサ６で前反射マーク３が通過したことを検知した後にこの前反射マーク３が通過したことを前光センサ５が検知するまでの時間を計測する時間計測部７と、
張力Ｔ_０に設定して無負荷でベルト１を走行させたときにおいて、後光センサ６の検知に基づいて時間計測部７で計測される、前反射マーク３が後光センサ６を通過した後に後反射マーク４が後光センサ６を通過するまでの時間をｔ_Ａ０、前光センサ５の検知に基づいて時間計測部７で計測される、前反射マーク３が後光センサ６を通過したことを検知した後にこの前反射マーク３が前光センサ５を通過するまでの時間をｔ_Ｂ０とし、
測定する張力Ｔでベルト１を走行させたときにおいて、後光センサ６の検知に基づいて時間計測部７で計測される、前反射マーク３が後光センサ６を通過した後に後反射マーク４が後光センサ６を通過するまでの時間をｔ_Ａ１、前光センサ５の検知に基づいて時間計測部７で計測される、後光センサ６で前反射マーク３が通過したことを検知した後にこの前反射マーク３が前光センサ５を通過するまでの時間をｔ_Ｂ１とすると、
Ｔ＝Ｔ_０＋Ｋ［（ｔ_Ａ１・ｔ_Ｂ０）／（ｔ_Ｂ１・ｔ_Ａ０）−１］
（Ｋはベルト固有の定数）
の式から張力Ｔを演算して求める張力演算部７と、を備えて成ることを特徴とするものである。 A belt tension measuring device according to a second aspect of the present invention includes a pulley 2 that suspends and drives the belt 1 to be measured,
A front reflection mark 3 and a rear reflection mark 4 provided on the belt 1 at two locations in the front and rear directions in the running direction;
A front light sensor 5 for detecting the passage of the front reflection mark 3 and a rear light sensor 6 for detecting the passage of the front reflection mark 3 and the rear reflection mark 4 provided at two positions along the belt 1 in the traveling direction. ,
After the rear light sensor 6 detects that the front reflection mark 3 has passed, the time until the rear light sensor 6 detects that the rear reflection mark 4 has passed is measured. A time measuring unit 7 that measures the time until the front light sensor 5 detects that the pre-reflection mark 3 has passed after detecting that the light has passed 3;
When the belt 1 is run with no load set to the tension T ₀ , after the front reflection mark 3 measured by the time measurement unit 7 based on the detection of the rear light sensor 6 passes through the rear light sensor 6. The time until the rear reflection mark 4 passes the rear light sensor 6 is t _A0 , which is measured by the time measuring unit 7 based on the detection of the front light sensor 5, and that the front reflection mark 3 has passed the rear light sensor 6. T _B0 is the time until the front reflection mark 3 passes through the front light sensor 5 after detecting
When the belt 1 is run with the tension T to be measured, the back reflection mark 4 is measured after the front reflection mark 3 passes through the rear light sensor 6 and is measured by the time measuring unit 7 based on the detection of the rear light sensor 6. The time until passing through the rear light sensor 6 is t _A1 , which is measured by the time measuring unit 7 based on the detection of the front light sensor 5, and after detecting that the front reflection mark 3 has passed through the rear light sensor 6. If the time until the front reflection mark 3 passes the front light sensor 5 is t _B1 ,
T = T ₀ + K [(t _A1 · t _B0 ) / (t _B1 · t _A0 ) −1]
(K is a constant specific to the belt)
And a tension calculating unit 7 that calculates and calculates the tension T from the equation (1).

本発明によれば、ベルト１を走行駆動しながら、ベルト１に設けた前反射マーク３や後反射マーク４を、前光センサ５や後光センサ６で検知して、前反射マーク３が通過したことを後光センサ６が検知した後に後反射マーク４が通過したことを後光センサ６が検知するまでの時間や、後光センサ６で前反射マーク３が通過したことを検知した後にこの前反射マーク３が通過したことを前光センサ５が検知するまでの時間を計測することによって、これらの計測時間からベルト１の走行駆動時の張力Ｔを求めることができ、ベルト１の張力を非接触で測定することができるものであり、ベルトの走行状態を変化させることなく正確に張力を測定することができるものである。しかも張力Ｔを求める演算式は計測時間のみを変数とする関数であり、ベルト１の走行速度、前反射マーク３と後反射マーク４の間の距離、前光センサ５と後光センサ６の間の距離などの精度高く測定できない数値が関与することがなく、張力Ｔを精度高く測定することができるものである。 According to the present invention, the front reflection mark 3 and the rear reflection mark 4 provided on the belt 1 are detected by the front light sensor 5 and the rear light sensor 6 while the belt 1 is driven to travel, and the front reflection mark 3 passes. The time until the rear light sensor 6 detects that the rear reflection mark 4 has passed after the rear light sensor 6 detects that the rear light sensor 6 has detected, or after the front light reflection sensor 3 detects that the front reflection mark 3 has passed. By measuring the time until the front light sensor 5 detects that the front reflection mark 3 has passed, the tension T when the belt 1 is driven to travel can be obtained from these measurement times. The tension can be measured without contact, and the tension can be accurately measured without changing the running state of the belt. In addition, the calculation formula for obtaining the tension T is a function having only the measurement time as a variable. The running speed of the belt 1, the distance between the front reflection mark 3 and the rear reflection mark 4, and between the front light sensor 5 and the rear light sensor 6. Therefore, the tension T can be measured with high accuracy without involving numerical values that cannot be measured with high accuracy, such as the distance of.

以下、本発明を実施するための最良の形態を説明する。 Hereinafter, the best mode for carrying out the present invention will be described.

図１は本発明の実施の形態の一例を示すものであり、複数のプーリ２の間にベルト１が懸架してある。図の実施の形態では、プーリ２ａが原動プーリ、プーリ２ｂが従動プーリとしてある。このベルト１の外面（ベルト背面）には長手方向に沿った２箇所に、前反射マーク３と後反射マーク４が設けてある。ベルト１の走行方向での前側に前反射マーク３が、後側に後反射マーク４が設けられるものである。これらの前反射マーク３や後反射マーク４は、ベルト１の表面における光の反射率よりも高い反射率を表面に有するものであれば何でも良いが、例えば光反射テープなどをベルト１の表面に貼って形成することができる。 FIG. 1 shows an example of an embodiment of the present invention, in which a belt 1 is suspended between a plurality of pulleys 2. In the illustrated embodiment, the pulley 2a is a driving pulley and the pulley 2b is a driven pulley. A front reflection mark 3 and a rear reflection mark 4 are provided at two locations along the longitudinal direction on the outer surface (belt back surface) of the belt 1. The front reflection mark 3 is provided on the front side in the running direction of the belt 1 and the rear reflection mark 4 is provided on the rear side. The front reflection mark 3 and the rear reflection mark 4 may be anything as long as the surface has a reflectance higher than the reflectance of light on the surface of the belt 1. For example, a light reflection tape or the like is applied to the surface of the belt 1. Can be pasted.

また、ベルト１の外面に対向する位置において、ベルト１の長手方向に沿った２箇所に前光センサ５と後光センサ６を配置して設けてある。ベルト１の走行方向での前側に前光センサ５が、後側に後光センサ６が配置されるものである。これらの前光センサ５や後光センサ６は、例えば発光素子と受光素子を備えて形成されるものであり、発光素子から発光された光の反射光を受光素子で受光することによって、検知対象物を検知することできるようにしたものである。 Further, the front light sensor 5 and the rear light sensor 6 are provided at two positions along the longitudinal direction of the belt 1 at a position facing the outer surface of the belt 1. The front light sensor 5 is disposed on the front side in the traveling direction of the belt 1 and the rear light sensor 6 is disposed on the rear side. The front light sensor 5 and the rear light sensor 6 are formed with, for example, a light emitting element and a light receiving element, and are detected by receiving reflected light of light emitted from the light emitting element by the light receiving element. An object can be detected.

すなわち、プーリ２によってベルト１を走行駆動させた際に、前光センサ５や後光センサ６から発光される光がベルト１の表面で反射されるときは、反射率が低いので、反射して前光センサ５や後光センサ６で受光される光の強度は小さいが、前光センサ５や後光センサ６から発光される光が前反射マーク３や後反射マーク４に照射されると、反射率が高いので、反射されて前光センサ５や後光センサ６で受光される光の強度は高く変化する。従って、前光センサ５や後光センサ６で受光される光の強度が高く変化したときに、前反射マーク３や後反射マーク４が前光センサ５や後光センサ６の位置を通過したということを検知することができるものである。 That is, when the belt 1 is driven by the pulley 2 and the light emitted from the front light sensor 5 and the rear light sensor 6 is reflected on the surface of the belt 1, the reflectivity is low. Although the intensity of light received by the front light sensor 5 or the rear light sensor 6 is small, when the light emitted from the front light sensor 5 or the rear light sensor 6 is irradiated to the front reflection mark 3 or the rear reflection mark 4, Since the reflectance is high, the intensity of the light that is reflected and received by the front light sensor 5 and the rear light sensor 6 changes high. Therefore, when the intensity of the light received by the front light sensor 5 or the rear light sensor 6 changes to a high level, the front reflection mark 3 or the rear reflection mark 4 passes through the positions of the front light sensor 5 or the rear light sensor 6. It is possible to detect this.

ここで、前反射マーク３と後反射マーク４の間の距離と、前光センサ５と後光センサ６の距離とは、等しく設定する必要はないものであり、近似する距離であればよい。 Here, the distance between the front reflection mark 3 and the rear reflection mark 4 and the distance between the front light sensor 5 and the rear light sensor 6 do not need to be set equal, and may be any approximate distance.

上記の前光センサ５及び後センサ６は、ＣＰＵ、ＲＡＭ、ＲＯＭ等を備えて形成される制御器９に電気的に接続してある。制御器９には時間計測部７と張力演算部８が形成されており、前光センサ５及び後センサ６は時間計測部７に接続されるものである。そして、プーリ２を回転してベルト１を走行駆動すると、ベルト１の走行によって前反射マーク３及び後反射マーク４が移動し、前反射マーク３や後反射マーク４が前光センサ５や後光センサ６の位置を通過する際に、受光の強度の変化で前反射マーク３や後反射マーク４が検知されるが、前光センサ５や後光センサ６からこの検知信号が時間計測部７に入力されると、時間計測部７のタイマー回路でパルス波形に変換されて記録されるようにしてある。 The front light sensor 5 and the rear sensor 6 are electrically connected to a controller 9 formed with a CPU, a RAM, a ROM, and the like. The controller 9 includes a time measuring unit 7 and a tension calculating unit 8, and the front light sensor 5 and the rear sensor 6 are connected to the time measuring unit 7. When the pulley 2 is rotated to drive the belt 1, the front reflection mark 3 and the rear reflection mark 4 are moved by the belt 1, and the front reflection mark 3 and the rear reflection mark 4 are moved to the front light sensor 5 and the rear light. When passing through the position of the sensor 6, the front reflection mark 3 and the rear reflection mark 4 are detected by a change in the intensity of received light. The detection signal is sent from the front light sensor 5 and the rear light sensor 6 to the time measuring unit 7. When input, it is converted into a pulse waveform by the timer circuit of the time measuring unit 7 and recorded.

このとき、ベルト１の走行によって前反射マーク３及び後反射マーク４はまず後光センサ６の位置を通過するが、図２（ａ）は後光センサ６で検知された前反射マーク３と後反射マーク４の検知信号によるパルスを示すものであり、前反射マーク３の検知パルスと後反射マーク４の検知パルスとの間の時間間隔を時間計測部７のタイマー回路で検出することによって、前反射マーク３が後光センサ６を通過した後に後反射マーク４が後光センサ６を通過するまでの時間ｔ_Ａが計測されるようにしてある。 At this time, the front reflection mark 3 and the rear reflection mark 4 first pass the position of the rear light sensor 6 by the running of the belt 1, but FIG. 2A shows the front reflection mark 3 detected by the rear light sensor 6 and the rear reflection mark 6. The pulse by the detection signal of the reflection mark 4 is shown, and the time interval between the detection pulse of the front reflection mark 3 and the detection pulse of the rear reflection mark 4 is detected by the timer circuit of the time measuring unit 7, thereby The time t _A until the rear reflection mark 4 passes the rear light sensor 6 after the reflection mark 3 passes the rear light sensor 6 is measured.

また図２（ｂ）は前光センサ５で検知された前反射マーク３と後反射マーク４の検知パルスを示すものであり、図２（ａ）の後光センサ６で検知された前反射マーク３の検知パルスと、前光センサ５で検知された前反射マーク３の検知パルスとの間の時間間隔を時間計測部７のタイマー回路で検出することによって、前反射マーク３が後光センサ６を通過した後にこの前反射マーク３が前光センサ５を通過するまでの時間ｔ_Ｂが計測されるようにしてある。 FIG. 2B shows detection pulses of the front reflection mark 3 and the rear reflection mark 4 detected by the front light sensor 5, and the front reflection mark detected by the rear light sensor 6 of FIG. 3 is detected by the timer circuit of the time measuring unit 7 by detecting the time interval between the detection pulse 3 and the detection pulse of the front reflection mark 3 detected by the front light sensor 5. The time t _B until the front reflection mark 3 passes the front light sensor 5 after passing through is measured.

以下、ベルト１の張力の測定について説明する。ベルト１をプーリ２間に懸架し、まず、従動プーリ２ｂが無負荷の状態でベルト１を走行させて基準試験を行なう。 Hereinafter, the measurement of the tension of the belt 1 will be described. The belt 1 is suspended between the pulleys 2, and first, a reference test is performed by running the belt 1 with the driven pulley 2b unloaded.

無負荷状態での走行中のベルト１の張力Ｔ_０の測定は、例えば図５に示す方法で行なうことができる。図５において、プーリ２のうち原動プーリ２ａの軸は可動体２０に、従動プーリ２ｂの軸は支持体１８にそれぞれ取り付けてあり、可動体２０及び支持体１８はそれぞれ矢印方向に移動できるようになっているが、支持体１８はロードセル１９に連結してあり、従動プーリ１８の軸荷重をロードセル１９で測定することができるようにしてある。そしてプーリ２ａ，２ｂ間にベルト１を懸架した状態で、引張治具２１で可動体２０を引いて移動させることによって、所定の張力をベルト１に掛けることができるようにしてあり、このときの従動プーリ１８の軸荷重をロードセル１９で測定することによって、ベルト１の張力を求めることができるものである。すなわち、従動プーリ２ｂを空転させる無負荷状態でベルト１を走行させた際の軸荷重をロードセル１９で測定すると、この軸荷重はベルト１の上部と下部（プーリ２の上に掛け渡される部分と下に掛け渡される部分）の各張力の和であるため、この無負荷状態でベルト１を走行させたときの張力Ｔ_０は、ロードセル１９で測定される軸荷重の１／２として求めることができるものである。 The measurement of the tension T ₀ of the belt 1 during traveling in an unloaded state can be performed, for example, by the method shown in FIG. In FIG. 5, the shaft of the driving pulley 2a of the pulley 2 is attached to the movable body 20, and the shaft of the driven pulley 2b is attached to the support body 18, so that the movable body 20 and the support body 18 can move in the directions of the arrows. However, the support 18 is connected to the load cell 19 so that the axial load of the driven pulley 18 can be measured by the load cell 19. Then, in a state where the belt 1 is suspended between the pulleys 2a and 2b, a predetermined tension can be applied to the belt 1 by pulling and moving the movable body 20 with the tension jig 21. By measuring the axial load of the driven pulley 18 with the load cell 19, the tension of the belt 1 can be obtained. That is, when the load on the shaft 1 is measured when the belt 1 is run in a no-load state in which the driven pulley 2b is idling, the shaft load is measured at the upper and lower portions of the belt 1 (the portion stretched over the pulley 2). The tension T ₀ when the belt 1 is run in this unloaded state can be obtained as ½ of the axial load measured by the load cell 19. It can be done.

また無負荷でベルト１を走行させる場合、ベルト１に走行時に作用する張力は、ベルト１の張力を停止状態で測定した張力とほぼ等しいので、プーリ２間にベルト１を懸架して停止状態で測定した張力Ｔ_０を、基準試験での張力Ｔ_０とすることもできるものである。この停止状態でのベルト１の張力の測定は、従来から提供されている種々の機器、例えば三ツ星ベルト（株）製「ドクターテンション」を用いて行なうことができる。 When running the belt 1 with no load, the tension acting on the belt 1 during running is almost equal to the tension measured when the belt 1 is stopped, so that the belt 1 is suspended between the pulleys 2 and stopped. the tension T ₀ measured, but can also be a tension T ₀ of the reference test. The measurement of the tension of the belt 1 in the stopped state can be performed using various conventionally provided devices such as “Doctor Tension” manufactured by Mitsuboshi Belting.

そして、この無負荷状態で基準試験を行なうものであり、張力Ｔ_０の状態でプーリ２を回転させてベルト１を所定の速度Ｖで走行駆動し、上記のように、前反射マーク３が後光センサ６を通過した後に後反射マーク４が後光センサ６を通過するまでの時間ｔ_Ａを計測する（この基準試験で計測された時間を時間ｔ_Ａ０とする）。また上記のように、前反射マーク３が後光センサ６を通過した後にこの前反射マーク３が前光センサ５を通過するまでの時間ｔ_Ｂを計測する（この基準試験で計測された時間を時間ｔ_Ｂ０とする）。 Then, the reference test is performed in this no-load state, the pulley 2 is rotated in the state of tension T ₀ , and the belt 1 is driven to travel at a predetermined speed V. As described above, the front reflection mark 3 is moved to the rear. The time t _A until the rear reflection mark 4 passes through the rear light sensor 6 after passing through the optical sensor 6 is measured (the time measured in this reference test is defined as time t _A0 ). Further, as described above, the time t _B until the front reflection mark 3 passes through the front light sensor 5 after the front reflection mark 3 passes through the rear light sensor 6 is measured (the time measured in this reference test). Time _tB0 ).

次に、荷重を従動プーリ２ｂに掛けて、荷重負荷の状態でプーリ２を回転させてベルト１を上記とほぼ同じ速度Ｖで走行駆動し、測定試験を行なう。本発明ではこの荷重負荷状態でベルト１を走行駆動する測定試験においてベルト１に作用する張力Ｔを測定しようとするものであり、上記のように、前反射マーク３が後光センサ６を通過した後に後反射マーク４が後光センサ６を通過するまでの時間ｔ_Ａを計測する（この測定試験で計測された時間を時間ｔ_Ａ１とする）。また上記のように、前反射マーク３が後光センサ６を通過した後にこの前反射マーク３が前光センサ５を通過するまでの時間ｔ_Ｂを計測する（この測定試験で計測された時間を時間ｔ_Ｂ１とする）。 Next, a load is applied to the driven pulley 2b, the pulley 2 is rotated under the load condition, and the belt 1 is driven to travel at substantially the same speed V as described above to perform a measurement test. In the present invention, the tension T acting on the belt 1 is to be measured in a measurement test in which the belt 1 is driven to run in this load state. As described above, the front reflection mark 3 has passed through the rear light sensor 6. The time t _A until the rear reflection mark 4 passes through the rear light sensor 6 is measured later (the time measured in this measurement test is defined as time t _A1 ). Further, as described above, the time t _B until the front reflection mark 3 passes the front light sensor 5 after the front reflection mark 3 passes the rear light sensor 6 is measured (the time measured in this measurement test is measured). Time t _B1 ).

ここで、前光センサ５と後光センサ６の間の距離をＬｓ、測定試験を行なう際の張力Ｔが作用するベルト１における、前反射マーク３と後反射マーク４の間の距離をＬとすると、ベルト１の走行速度Ｖは次の式（１）で表される。 Here, the distance between the front light sensor 5 and the rear light sensor 6 is Ls, and the distance between the front reflection mark 3 and the rear reflection mark 4 in the belt 1 on which the tension T during the measurement test is applied is L. Then, the running speed V of the belt 1 is expressed by the following formula (1).

Ｖ＝Ｌ／ｔ_Ａ１＝Ｌ_Ｓ／ｔ_Ｂ１（１）
そしてこの式（１）から次の式（２）が導かれる。 V = L / t _A1 = L _S / t _B1 (1)
Then, the following equation (2) is derived from this equation (1).

Ｌ＝（ｔ_Ａ１／ｔ_Ｂ１）・Ｌ_Ｓ（２）
一方、測定試験においてベルト１に作用する張力Ｔは、無負荷での基準試験における張力Ｔ_０に、張力の増加あるいは減少の張力変動分ΔＴが付加されたものであり、この張力変動分ΔＴは、基準試験時に対する測定試験時のベルト１の伸び率と、ベルト１に固有の弾性率などの定数Ｋとの積である。従って、基準試験時の張力Ｔ_０が作用するベルト１における前反射マーク３と後反射マーク４の間の距離をＬ_０、測定試験時の前反射マーク３と後反射マーク４の間の距離を上記のようにＬとすると、ベルト１の伸び率は（Ｌ−Ｌ_０）／Ｌ_０であるから、次の関係式（３）が成立する。 L = (t _A1 / t _B1 ) · L _S (2)
On the other hand, the tension T acting on the belt 1 in the measurement test is obtained by adding a tension fluctuation ΔT of increase or decrease in tension to the tension T ₀ in the reference test without load. The product of the elongation percentage of the belt 1 during the measurement test with respect to the reference test time and a constant K such as the elastic modulus inherent in the belt 1. Therefore, the distance between the front reflection mark 3 and the rear reflection mark 4 in the belt 1 to which the tension T ₀ is applied during the reference test is L ₀ , and the distance between the front reflection mark 3 and the rear reflection mark 4 is measured during the measurement test. Assuming that L is as described above, since the elongation percentage of the belt 1 is (L−L ₀ ) / L ₀ , the following relational expression (3) is established.

Ｔ−Ｔ_０＝ΔＴ＝Ｋ・（Ｌ−Ｌ_０）／Ｌ_０（３）
そしてこの式（３）と上記の式（２）から、次の式（４）が成立する。 T−T ₀ = ΔT = K · (L−L ₀ ) / L ₀ (3)
From this equation (3) and the above equation (2), the following equation (4) is established.

ΔＴ＝（Ｋ／Ｌ_０）・［（ｔ_Ａ１／ｔ_Ｂ１）・Ｌ_Ｓ−Ｌ_０］（４）
またベルト１の走行速度Ｖは次の式（５）でも表される。 ΔT = (K / L ₀ ) · [(t _A1 / t _B1 ) · L _S −L ₀ ] (4)
The traveling speed V of the belt 1 is also expressed by the following equation (5).

Ｖ＝Ｌ_０／ｔ_Ａ０＝Ｌ_Ｓ／ｔ_Ｂ０（５）
この式（５）から次の式（６）が導かれる。 V = L ₀ / t _A0 = L _S / t _B0 (5)
From this equation (5), the following equation (6) is derived.

Ｌ_Ｓ＝（ｔ_Ｂ０／ｔ_Ａ０）・Ｌ_０（６）
そしてこの式（６）と上記の式（４）とから、次の式（７）が成立する。 L _S = (t _B0 / t _A0 ) · L ₀ (6)
From this equation (6) and the above equation (4), the following equation (7) is established.

ΔＴ＝（Ｋ／Ｌ_０）・［（ｔ_Ａ１／ｔ_Ｂ１）・（ｔ_Ｂ０／ｔ_Ａ０）・Ｌ_０−Ｌ_０］
＝Ｋ・［（ｔ_Ａ１／ｔ_Ｂ１）・（ｔ_Ｂ０／ｔ_Ａ０）−１］（７）
従って、測定試験時の張力Ｔ＝Ｔ_０＋ΔＴであるから、測定試験の際に走行駆動されるベルト１に作用する張力Ｔは、次の式（８）で求めることができる。 ΔT = (K / L ₀ ) · [[t _A1 / t _B1 ) · (t _B0 / t _A0 ) · L ₀ −L ₀ ]
= K · [(t _A1 / t _B1 ) · (t _B0 / t _A0 ) −1] (7)
Accordingly, since the tension T during the measurement test is T = T ₀ + ΔT, the tension T acting on the belt 1 that is travel-driven during the measurement test can be obtained by the following equation (8).

Ｔ＝Ｔ_０＋Ｋ［（ｔ_Ａ１・ｔ_Ｂ０）／（ｔ_Ｂ１・ｔ_Ａ０）−１］（８）
ここで、この演算式（８）は制御器９の張力演算部８に予め入力して保存されており、ベルト１に固有の定数Ｋも張力演算部８に予め入力して保存されている。また基準試験を行なった際の張力Ｔ_０や、基準試験を行なった際に時間計測部７で計測された時間ｔ_Ａ０，ｔ_Ｂ０のデータも張力演算部８に入力して保存されている。 T = T ₀ + K [(t _A1 · t _B0 ) / (t _B1 · t _A0 ) −1] (8)
Here, the calculation formula (8) is input and stored in advance in the tension calculation unit 8 of the controller 9, and a constant K unique to the belt 1 is also input and stored in the tension calculation unit 8 in advance. Further, the tension T ₀ when the reference test is performed and the data of the times t _A0 and t _B0 measured by the time measurement unit 7 when the reference test is performed are also input to the tension calculation unit 8 and stored.

そして上記のように、測定試験を行なって、前光センサ３と後光センサ４による検知に基づいて時間計測部７で計測された時間ｔ_Ａ１，ｔ_Ｂ１が張力演算部８に入力されると、式（８）の演算式に基づいて演算がなされ、測定試験の際に走行駆動されるベルト１に作用する張力Ｔが求められるものである。尚、基準試験はベルト１について一度行なうだけでよく、基準試験で得たデータに基づいて、測定試験で種々の張力でベルト１をプーリ２に懸架して走行駆動した際の張力Ｔを測定することができるものである。 As described above, when the measurement test is performed and the times t _A1 and t _B1 measured by the time measuring unit 7 based on the detection by the front light sensor 3 and the rear light sensor 4 are input to the tension calculation unit 8. The calculation is performed based on the calculation formula of Formula (8), and the tension T acting on the belt 1 that is driven to travel during the measurement test is obtained. The reference test only needs to be performed once for the belt 1, and based on the data obtained in the reference test, the measurement test measures the tension T when the belt 1 is suspended and driven by the pulley 2 with various tensions. It is something that can be done.

このようにして、前センサ３や後センサ４によって非接触で得られたデータによって、走行駆動時のベルト１の張力を測定することができるものであり、ベルト１の走行状態を変化させることなく、正確に張力を測定することが可能になるものである。しかも張力Ｔを求める演算式（８）は、計測時間のみを変数とする関数であり、ベルト１の走行速度Ｖ、前反射マーク３と後反射マーク４の間の距離Ｌ_０，Ｌ、光センサ５と後光センサ６の間の距離Ｌ_Ｓのように精度高く測定できない数値を関与させることなく、張力Ｔを求めることができる。従って、例えば０．０２５％以下程度に計測時間の精度を高めることによって、張力Ｔを精度高く測定することができるものである。また、従来のようにプーリ２の間に張力測定用プーリ１７を配置するような必要がなく、プーリ２の軸間距離が短い場合でも容易に測定することができるものであり、さらに張力測定用プーリ１７を用いる場合のように、ベルト１が使用される対象機械やエンジンに合った軸をその度に作製しなければならないというような問題もなくなるものである。 In this way, the tension of the belt 1 at the time of traveling drive can be measured based on the data obtained without contact by the front sensor 3 and the rear sensor 4 without changing the traveling state of the belt 1. This makes it possible to accurately measure the tension. Moreover, the calculation formula (8) for obtaining the tension T is a function having only the measurement time as a variable, and the running speed V of the belt 1, the distances L ₀ and L between the front reflection mark 3 and the rear reflection mark 4, an optical sensor. The tension T can be obtained without involving a numerical value that cannot be measured with high accuracy, such as the distance L _S between 5 and the rear light sensor 6. Therefore, for example, the tension T can be measured with high accuracy by increasing the accuracy of the measurement time to about 0.025% or less. Further, there is no need to arrange the tension measuring pulley 17 between the pulleys 2 as in the prior art, and it is possible to easily measure even when the distance between the axes of the pulley 2 is short. As in the case where the pulley 17 is used, the problem that the shaft suitable for the target machine or engine in which the belt 1 is used must be produced each time is eliminated.

次に、上記の演算式（８）の有効性を検証する実施例を示す。 Next, an embodiment for verifying the validity of the arithmetic expression (8) will be shown.

ベルト１として５ＰＫ１３９０タイプのＶリブドベルトを用い、ベルト１の背面に光反射テープを２０５ｍｍの間隔で貼って前反射マーク３と後反射マーク４を設けた。このベルト１の引張弾性率Ｋは９８ｋＮである。また前光センサ５及び後光センサ６としてキーエンス社製「ＦＳ−Ｍ１Ｈ」を用い、２００ｍｍの間隔で配置した。 A 5PK1390 type V-ribbed belt was used as the belt 1, and a front reflection mark 3 and a rear reflection mark 4 were provided on the back of the belt 1 by attaching a light reflection tape at intervals of 205 mm. The belt 1 has a tensile elastic modulus K of 98 kN. Further, “FS-M1H” manufactured by Keyence Corporation was used as the front light sensor 5 and the rear light sensor 6, and they were arranged at intervals of 200 mm.

そしてこのベルト１を図５に示す装置の、１２０ｍｍφの原動プーリ２ａと１２０ｍｍφの従動プーリ２ｂの間に懸架し、回転数１３０６ｒｐｍ（Ｖ＝８．２１ｍ／ｓ）と、回転数１７５４ｒｐｍ（Ｖ＝１１．０２ｍ／ｓ）でそれぞれ回転させてベルト１を走行駆動して、試験を行なった。 The belt 1 is suspended between a driving pulley 2a of 120 mmφ and a driven pulley 2b of 120 mmφ in the apparatus shown in FIG. 5, and rotates at 1306 rpm (V = 8.21 m / s) and 1754 rpm (V = 11). The belt 1 was driven to run at a speed of 0.02 m / s), and the test was performed.

まず、ベルト１をプーリ２ａ，２ｂ間に懸架し、ベルト１を走行させながら原動プーリ２ａを移動させ、ロードセル１９による測定で求められるベルト１の張力Ｔ_０＝５０Ｎ／ｒｉｂ（１リブ当たりの張力）となるように、原動プーリ２ａと従動プーリ２ｂの軸間距離を調整した。そしてこのまま無負荷状態でベルト１を走行させ基準試験を行ない、ｔ_Ａ０とｔ_Ｂ０を求めた。 First, the belt 1 is suspended between the pulleys 2a and 2b, the driving pulley 2a is moved while the belt 1 is running, and the tension T _{0 of the} belt 1 obtained by measurement by the load cell 19 is equal to 50 N / rib (tension per rib). ), The distance between the axes of the driving pulley 2a and the driven pulley 2b was adjusted. Then, the belt 1 was run in the no-load state as it was and a reference test was performed to obtain t _A0 and t _B0 .

次に、原動プーリ２ａを移動させて原動プーリ２ａと従動プーリ２ｂの軸間距離を種々の距離に調節し、各軸間距離の状態でベルト１を走行させて、このときにベルト１に掛かる張力をロードセル１９によって実張力として測定し、またこの状態でベルト１を走行させて測定試験を行ない、ｔ_Ａ１とｔ_Ｂ１を求めた。 Next, the driving pulley 2a is moved to adjust the distance between the shafts of the driving pulley 2a and the driven pulley 2b to various distances, and the belt 1 is run in the state of the distance between the shafts. tension was measured as the actual tension by the load cell 19, also performs measurement test by running the belt 1 in this state to determine the t _A1 and t _B1.

そして、Ｋ、Ｔ_０及び基準試験で求めたｔ_Ａ０、ｔ_Ｂ０、測定試験で求めたｔ_Ａ１とｔ_Ｂ１を演算式（８）に代入することによって、種々の張力でプーリ２ａ，２ｂ間に懸架して走行駆動した際のベルト１の張力Ｔを計算して求めた。 Then, by substituting K A, T ₀ , t _A0 , t _B0 obtained in the reference test, and t _A1 and t _B1 obtained in the measurement test into the arithmetic expression (8), between the pulleys 2 a and 2 b with various tensions. The tension T of the belt 1 when it was suspended and traveled was calculated and obtained.

次に、このように演算式（８）から計算して求めた計算張力を縦軸、ロードセル１９で測定した実張力を横軸にとって、図３に示すようにプロットし、計算張力と実測張力とを比較した。図３にみられるように、演算式（８）から計算して求めた計算張力と実張力の間には、張力や回転数が変わってもほぼ相関関係がみられるものであり、演算式（８）を用いた本発明に係る張力測定方法は十分に実用的であることが確認される。 Next, plotted as shown in FIG. 3 with the calculated tension calculated from the calculation formula (8) in the vertical axis and the actual tension measured by the load cell 19 as the horizontal axis, as shown in FIG. Compared. As shown in FIG. 3, the calculated tension obtained from the calculation formula (8) and the actual tension are substantially correlated even if the tension and the rotational speed are changed. It is confirmed that the tension measuring method according to the present invention using 8) is sufficiently practical.

本発明の実施の形態の一例を示す概略図である。It is the schematic which shows an example of embodiment of this invention. （ａ）は後光センサによる前反射マークと後反射マークの検知時刻を示すパルス波形のグラフ、（ｂ）は前光センサによる前反射マークと後反射マークの検知時刻を示すパルス波形のグラフである。(A) is a pulse waveform graph showing the detection time of the front reflection mark and the rear reflection mark by the rear light sensor, and (b) is a pulse waveform graph showing the detection time of the front reflection mark and the rear reflection mark by the front light sensor. is there. 計算張力と実測張力の相関関係を示すグラフである。It is a graph which shows the correlation of calculated tension | tensile_strength and measured tension | tensile_strength. 軸荷重測定法を示すものであり、（ａ）、（ｂ）はそれぞれ概略図である。The axial load measuring method is shown, and (a) and (b) are schematic diagrams respectively. ベルトの張力を検証するための測定装置を示す概略図である。It is the schematic which shows the measuring apparatus for verifying the tension | tensile_strength of a belt.

Explanation of symbols

１ベルト
２プーリ
３前反射マーク
４後反射マーク
５前光センサ
６後光センサ
７時間計測部
８張力演算部 1 Belt 2 Pulley 3 Front Reflection Mark 4 Rear Reflection Mark 5 Front Light Sensor 6 Rear Light Sensor 7 Time Measurement Unit 8 Tension Calculation Unit

Claims

A method of measuring a tension T acting on a belt when the belt to be measured is suspended and driven by a pulley,
A front light sensor for providing a front reflection mark and a rear reflection mark at two front and rear positions in the running direction on the surface of the belt, and detecting passage of the front reflection mark at two front and rear positions in the running direction along the belt. And a rear light sensor for detecting the passage of the front reflection mark and the rear reflection mark,
Time until the rear light sensor detects that the rear reflection mark has passed after the rear light sensor has detected that the front reflection mark has passed when the belt is run with no load with the tension T ₀ set. measuring t _A0, and measuring a time t _B0 until the front light sensor detects that the front reflection mark has passed after detecting that the front reflection mark has passed by the rear light sensor,
When the belt is run at the tension T to be measured, a time t _A1 from when the rear light sensor detects that the front reflection mark has passed after the rear light sensor detects that the front reflection mark has passed is measured. And measuring the time t _B1 until the front light sensor detects that the front reflection mark has passed after the rear light sensor has detected that the front reflection mark has passed,
T = T ₀ + K [(t _A1 · t _B0 ) / (t _B1 · t _A0 ) −1]
(K is a constant specific to the belt)
A method for measuring the tension of a belt, wherein the tension T is obtained from the formula:

A pulley that travels by suspending a belt to be measured;
A front reflection mark and a rear reflection mark provided on the belt at two locations in the front and rear directions in the running direction;
A front light sensor for detecting the passage of the front reflection mark and the rear reflection mark, and a rear light sensor for detecting the passage of the front reflection mark, which are provided at two locations along the belt in the traveling direction;
After the rear light sensor detects that the front reflection mark has passed, it measures the time until the rear light sensor detects that the rear reflection mark has passed, and indicates that the front reflection mark has passed by the rear light sensor. A time measuring unit that measures the time until the front light sensor detects that the previous reflection mark has passed after detection;
In case that was running the belt under no load is set to the tension T _0, is measured by the time measuring unit based on the detection of the halo sensor, after the rear reflection mark after the previous reflection marks has passed the halo sensor The time until passing through the optical sensor is t _A0 , which is measured by the time measurement unit based on the detection of the front light sensor, and after detecting that the front reflection mark has passed through the rear light sensor, _Let t _B0 be the time to pass the sensor,
When the belt is run at the tension T to be measured, the time reflection unit measures the time based on the detection of the rear light sensor, and then the rear reflection mark passes the rear light sensor after passing the rear light sensor. The time until t _A1 is measured by the time measurement unit based on the detection of the front light sensor, and after detecting that the front reflection mark has passed by the rear light sensor, until the front reflection mark passes the front light sensor _Let t _B1 be the time of
T = T ₀ + K [(t _A1 · t _B0 ) / (t _B1 · t _A0 ) −1]
(K is a constant specific to the belt)
And a tension calculating unit that calculates and calculates the tension T from the equation (1).