JP2006184194A - Thrust detector and calibration device of air-driven valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thrust detector and a calibration device for air-driven valve capable of diagnosing the thrust of a stem with a further simple structure, compared with a conventional one. <P>SOLUTION: Since measurement data in which thrusts acting on the stem 14 are conformed to distortions detected by a distortion sensor 3 is stored in a storage part 50, the thrust of the stem 14 can be detected from the distortion of a yoke 7 only by attaching the distortion sensor 3 to the yoke 7, and the thrust of the stem can be thus diagnosed with a further simple structure, compared with the conventional one. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thrust detecting device and a calibration device for an air driven valve that detect thrust applied to a stem of the air driven valve.

  Conventionally, a diaphragm is provided inside the air driving chamber, and this diaphragm is operated by the operating air pressure and the return spring, and the stem linked to the diaphragm is reciprocated in the axial direction in accordance with this, and the valve is operated in the valve box. There is known an air-driven valve that opens and closes a body.

  By the way, in the air-driven valve having such a configuration, a gland packing is provided between the stem and the valve box, and a frictional force is generated because the stem moves forward and backward while sliding with respect to the gland packing. The thrust that is applied to changes. The thrust applied to such a stem also changes when the valve element comes into contact with or separates from the valve seat depending on the properties of the controlled fluid, temperature, pressure, presence or absence of impurities, and the like.

  Therefore, in order to detect thrust applied to such a stem in an air driven valve, an abnormality notification device in a valve device in which a mounting hole is provided in a valve stem as a stem and a strain gauge is attached to the inner surface of this mounting hole has been proposed. (For example, Patent Document 1).

  In this valve device abnormality alarm device, the strain in the axial direction of the valve stem is detected by a strain gauge as a strain sensor, and based on the detection result, the thrust of the valve stem taking into account the properties of the diaphragm and the frictional force in the gland packing is taken into account. It can be detected.

  In addition, as a device for detecting thrust applied to a stem in an air driven valve, there has been proposed a control valve operation diagnosis device provided with an axial force sensor as a load detecting means between a bottom portion of a yoke and a valve shaft as a stem. (For example, Patent Document 2).

In this control valve operation diagnostic device, the axial force sensor detects the tensile force or compressive force applied in the axial direction of the valve shaft, and the characteristics of the diaphragm and the frictional force in the gland packing are taken into account based on the detection results. It is designed to detect the thrust of the valve stem.
JP 2001-108142 A JP 2003-90457 A

  However, in the abnormality notification device in the valve device having such a configuration, a strain gauge needs to be pasted in advance on the inner surface of the mounting hole provided in the valve stem, and a drawing hole provided in a side portion of the mounting hole is provided. Therefore, there is a problem that the structure is complicated because the lead wire of the strain gauge needs to be led to the outside.

  The above-described control valve operation diagnostic apparatus also has a problem in that the structure thereof is complicated because an axial force sensor needs to be provided in advance between the bottom of the yoke and the upper end side of the valve shaft.

  In view of the above-described problems, an object of the present invention is to provide a thrust detecting device and a calibration device for an air-driven valve that can detect the thrust of a stem with a simpler configuration than the conventional one.

  In order to achieve the above object, an invention according to claim 1 includes an air driving chamber provided with a diaphragm that is displaced by a return elastic means and an operating air pressure, and an air driving chamber that is connected to the air driving chamber. In a thrust detecting device for detecting thrust in an air-driven valve having a yoke through which a linking stem is inserted and a valve body that opens and closes in response to the advance and retreat of the stem, the distortion of the yoke that occurs in response to the advance and retreat of the stem The strain detected by the strain detection means corresponds to the thrust acting on the stem calculated based on the pressure detection means for detecting the pressure, the pressure data of the air driving chamber and the elastic force of the return elastic means. And storage means for storing the attached measurement data in advance.

  According to a second aspect of the present invention, there is provided an air driving chamber having a diaphragm displaced therein by a return elastic means and an operating air pressure, and a stem connected to the air driving chamber and connected to the diaphragm. A thrust detecting device for detecting a thrust in an air driven valve comprising a yoke and a valve element that opens and closes in accordance with the advancement and retraction of the stem, based on the distortion of the yoke, Acquiring means for acquiring the accompanying distortion of the yoke as a strain amount, supply / discharge means for supplying trial working air into the air driving chamber and discharging the trial working air in the air driving chamber, and the air driving chamber The thrust acting on the stem is calculated based on the pressure measuring means for measuring the pressure data of the air, the pressure data of the air driving chamber and the elastic force of the return elastic means , Characterized in that it comprises a calibratable calibration means the distortion of the yoke by associating the thrust to the distortion amount obtained by the obtaining means.

  According to the thrust detecting device of the first aspect of the present invention, the measurement data in which the thrust acting on the stem is associated with the amount of strain detected by the strain detecting means is stored in advance in the storage means. It is possible to detect the thrust of the stem from the distortion of the yoke only by attaching the strain detecting means to the stem, and thus it is possible to diagnose the thrust of the stem with a simpler configuration than in the past.

  Further, according to the calibration device of the second aspect, since the distortion of the yoke can be calibrated by associating the thrust acting on the stem with the amount of distortion, the yoke can be simply detected by detecting the distortion of the yoke in the thrust detection device. Thus, the stem thrust can be accurately detected from the strain of the stem, and thus the stem thrust can be diagnosed with a simpler configuration than in the prior art.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  In FIG. 1, reference numeral 1 denotes a thrust diagnosis device with a calibration function as a thrust detection device and a calibration device for an air driven valve. This thrust diagnostic apparatus 1 with a calibration function includes an apparatus main body 2, a strain sensor 3 attached to a yoke 7 of a diaphragm valve 5, and a pressure measuring unit 4 attached to the diaphragm valve 5 by a supply port attaching part 4a. Has been.

  Here, the diaphragm valve 5 to which the thrust diagnostic apparatus 1 with the calibration function is attached will be described first.

  The diaphragm valve 5 has a valve body 6 connected to a pipe (not shown) by a flange, and an air driving unit 8 is provided on the upper part of the valve body 6 via a yoke 7.

  The valve body 6 moves up and down in the valve box 12a, a valve box 12a having a valve hole 11 in a partition wall 10 that divides the inside, a bonnet 12b that fixes the yoke 7 and the valve box 12a with bolts 20a and 20b, and the valve box 12a. Thus, a valve body 13 that opens and closes the valve hole 11 and a stem 14 that moves the valve body 13 up and down are configured.

  Here, the bonnet 12b is provided with a through hole 15 through which the stem 14 is inserted, and a gland packing 16 is provided between the through hole 15 and the stem 14. The through-hole 15 is provided with a packing presser 18 for holding and compressing the gland packing 16, and the bolt 19 can be tightened to increase the compression margin of the gland packing 16, and thus the gland Leakage due to aging of the packing 16 can be prevented.

  Further, a guide ring 17 is provided inside the valve box 12a, and a stem 14 is inserted into the guide ring 17.

  Thus, the stem 14 is supported by the guide ring 17 and can slide up and down while maintaining airtightness in the valve box 12a by the gland packing 16.

  The upper end of the stem 14 passes through a yoke 7 fixed to the valve body 6, is supported by a seal packing 21 provided at the center of the yoke 7, and is an air drive unit fixed to the upper portion of the yoke 7 by a bolt 22. 8 is inserted.

  Here, the yoke 7 has a function of bearing a reaction force generated by the opening / closing operation of the valve body 13 and is configured so that the valve body 6 and the air driving unit 8 can be integrated using bolts 20a and 22. Yes.

  The air driving unit 8 includes an air driving chamber 24 having a slightly flat circular dish shape and having a hollow portion 23, and an upper end of the stem 14 is attached to a diaphragm 25 that divides the air driving chamber 24 into two chambers. .

  Actually, the hollow portion 23 of the air drive chamber 24 includes a pneumatic chamber 30 having a pneumatic supply port 38 on the lower surface, and a return spring 31 that opposes the operating air pressure and biases the diaphragm 25 toward the pneumatic chamber 30. The spring chamber 32 is provided.

  Here, the return spring 31 is provided between the first spring receiving plate 35 of the adjusting bolt 34 screwed into the top wall of the lid 33 and the second spring receiving plate 36 provided above the diaphragm 25. The second spring receiving plate 36, the diaphragm 25 and the stem 14 are urged downward by the spring force as the elastic force, and the valve body 13 is fully closed. The screw lid 37 provided on the top wall of the lid 33 can be operated by operating the adjusting bolt 34 by removing it.

  Thus, in the diaphragm valve 5, when the diaphragm 25 is pushed downward by the return spring 31, the valve body 13 is held in the fully closed state via the stem 14. In this state, the diaphragm valve 5 raises the pressure in the pneumatic chamber 30 by supplying the required working air to the pneumatic chamber 30 from the pneumatic supply port 38, and raises the diaphragm 25 against the return spring 31. Thereby, the diaphragm valve 5 can raise the stem 14 integrally with the diaphragm 25, and can open the valve body 13 according to the supply amount of working air.

  On the other hand, when the valve body 13 is in the fully open state, the pressure in the pneumatic chamber 30 is reduced, so that the diaphragm 25 is lowered and returned by the discharge amount of the working air and the spring force of the return spring 31. Can be closed again.

  When the valve body 13 moves up and down in this way, the stem 14 receives sliding resistance from the gland packing 16, the guide ring 17 and the seal packing 21, and a tensile or compressive load acts on the sliding resistance. Alternatively, the compressive load acts on the yoke 7 to cause distortion in the yoke 7.

  Next, the configuration of the thrust diagnostic apparatus with a calibration function 1 attached to the diaphragm valve 5 described above will be described below.

  In the thrust diagnostic apparatus 1 with a calibration function according to the present invention, a supply port mounting portion 4a is connected to the apparatus body 2 via a tube 4b. The supply port attachment portion 4a is configured to be detachable from the air pressure supply port 38 of the diaphragm valve 5.

  The apparatus main body 2 has an air tank 41 to which a tube 4b from the supply port mounting portion 4a is connected, and a compressor 42. When the pressure of the trial working air pressure stored in the air tank 41 decreases, the apparatus 42 Trial working air is replenished into the air tank 41.

  Incidentally, a compressor driving unit 46 connected to the control unit 45 as shown in FIG.

  Here, the thrust diagnostic device with calibration function 1 is an amplifier 49 to which a pressure measuring unit 4, a compressor driving unit 46, and a strain sensor 3 are connected to a control unit 45 that comprehensively controls the thrust diagnostic device with calibration function 1. The storage unit 50 and the display unit 51 are connected.

  Among these various circuit units, in the thrust diagnostic device 1 with the calibration function, the thrust detection circuit 45a of the control unit 45, the strain sensor 3, the amplifier 49, the storage unit 50, and the display unit 51 are used as the thrust detection device. Consists of 40a.

  In the thrust diagnostic apparatus 1 with the calibration function, the calibration circuit 45b of the control unit 45, the pressure measurement unit 4, the air tank 41, the compressor 42, and the compressor driving unit 46 constitute a calibration device 40b. .

  The calibration circuit 45b drives the compressor drive unit 46 based on an operation command from a controller (not shown) connected to the control unit 45 in the calibration mode for calibrating the strain sensor 3, and performs a trial operation in the air tank 41. Air can be supplied into the air drive chamber 24 via the supply port mounting portion 4a to increase the pressure in the pneumatic chamber 30.

  Further, the calibration circuit 45b is adapted to discharge the trial air from the pneumatic chamber 30 via the pneumatic supply port 38 and reduce the pressure in the pneumatic chamber 30, and thus air drive using the trial working air. The pressure in chamber 24 can be varied.

  As a result, the thrust diagnostic apparatus with calibration function 1 supplies or discharges the trial working air from the supply port attachment portion 4a attached to the air pressure supply port 38 of the air driving chamber 24 (FIG. 1) in the calibration mode. The valve body 13 can be opened and closed through the stem 14 by moving the valve 25 up and down.

  In addition to such a configuration, the calibration circuit 45b is configured so that the opening / closing degree of the valve body 13 and the trial operating air pressure when the valve body 13 is opened / closed as shown in FIGS. Data H2 and H3 representing the relationship with the applied operating force can be calculated.

  That is, the thrust diagnostic apparatus with a calibration function 1 uses the pressure measuring unit 4 to calculate the pressure in the air driving chamber 24 when the valve body 13 is raised and the pressure in the air driving chamber 24 when the valve body 13 is lowered. Each measurement is performed, and these measurement results are sent to the control unit 45 as pressure data.

  Thereby, the calibration circuit 45b calculates the operating force that the trial operating air pressure applies to the diaphragm 25 from the pressure data, the area of the diaphragm 25, and the like.

  Further, the calibration circuit 45b receives movement distance data from a movement detection unit (not shown) that detects the movement amount of the stem 14, and valve opening degree information indicating the current degree of opening and closing of the valve body 13 from the movement distance data. Have been made to get.

  Thus, the calibration circuit 45b obtains data H2 and H3 representing the relationship between the actuation force as shown in FIGS. 3A and 3B and the degree of opening and closing of the valve body 13 associated with the actuation force.

  In addition to this configuration, the calibration circuit 45b includes a spring force of the return spring 31 in the stroke from the fully closed state to the fully open state as shown in FIGS. 3 (A) and 3 (B). The data H1 representing is previously input, and the difference between the data H1 and the data H2 and H3 is calculated, and these differences (shaded portions in FIGS. 3A and 3B) are detected as the thrust of the stem 14. It is made to be able to do.

  That is, when the trial working air pressure is changed to move the valve body 13 from the fully closed state to the fully open state, the stem 14 linked to the diaphragm 25 has a frictional force due to the gland packing 16 or the like, or the pressure in the valve box 12a. Resistance occurs due to various causes, such as the nature of the control fluid, temperature, pressure, and the presence or absence of impurities.

  For this reason, even if an actuation force corresponding to only the spring force of the return spring 31 is applied, the valve body 13 does not rise due to the resistance force and maintains the fully closed state. Thereafter, the spring force and resistance force of the return spring 31 are maintained. When the operating force becomes larger than the above, the valve body 13 starts to open from the fully closed state.

  Therefore, when the valve body 13 is shifted from the fully closed state to the fully open state, the operating force given by the trial operating air pressure is greater than the spring force and resistance force of the return spring 31 and is shown in FIG. It becomes like data H2.

  On the other hand, when changing the operating air pressure for trial to shift the valve body 13 from the fully open state to the fully closed state, the stem 14 linked to the diaphragm 25 has a frictional force due to the gland packing 16 or the like, or the valve box. Resistance occurs due to various factors such as the properties of the controlled fluid in 12a, temperature, pressure, and the presence or absence of impurities.

  For this reason, even if an operating force corresponding only to the spring force of the return spring 31 is applied, the valve element 13 does not descend due to the resistance force and maintains the fully open state. When the spring force becomes larger than the resistance force, the valve body 13 starts to close from the fully open state.

  Therefore, when the valve body 13 is shifted from the fully open state to the fully closed state, the operating force applied by the trial operating air pressure is such that the spring force of the return spring 31 is greater than the low drag force. It is much smaller than the spring force, and becomes data H3 shown in FIG.

  Then, in the calibration mode, the calibration circuit 45b compares the data H2 when the valve body 13 transitions from the fully closed state to the fully opened state and the data H1 representing the spring force of the return spring 31 for each opening / closing degree. Calculate the difference. As a result, the calibration circuit 45b detects the difference between the data H2 and the data H1 (the hatched portion in FIG. 3A) as the thrust of the stem 14 when the valve body 13 shifts from the fully closed state to the fully open state. .

  In addition, the calibration circuit 45b compares the data H3 when the valve body 13 shifts from the fully open state to the fully closed state and the data H1 representing the spring force of the return spring 31 for each opening / closing degree, and calculates the difference. calculate. Thereby, the control unit 45 detects the difference between the data H3 and the data H1 (the hatched portion in FIG. 3B) as the thrust of the stem 14 when the valve body 13 shifts from the fully open state to the fully closed state. . In this way, the thrust diagnostic apparatus with calibration function 1 can detect a change in thrust acting on the stem 14 as the valve body 13 moves up and down.

  By the way, when the valve body 13 moves up and down, the stem 14 receives sliding resistance from the gland packing 16, the guide ring 17, and the like. A thrust in the tension or compression direction acts on the stem 14 by the resistance force due to the sliding resistance. A thrust reaction force acting on the stem 14 acts on the yoke 7, and distortion as shown in FIG. 4 occurs in the yoke 7.

  Here, the strain sensor 3 detects the strain generated in the yoke 7 as a strain amount, sends it to the amplifier 49 and converts it into an electrical signal, and sends it to the control unit 45.

  Then, the calibration circuit 45b of the control unit 45 associates the strain amount detected by the strain sensor 3 with the calculated thrust in a one-to-one relationship based on the valve opening information in the calibration mode, so that the strain sensor 3 The strain amount detected in (1) is defined by the thrust amount, and the strain amount thus defined by the thrust amount is stored in the storage unit 50 as measurement data, and the calibration mode is terminated.

  As described above, the calibration circuit 45b has a function as an arithmetic unit, and is capable of calibrating the strain sensor 3 by making the distortion generated in the yoke 7 correspond to the thrust. Note that the above-described calibration process as the calculation process may be executed by a calibration process program stored in a ROM (Read Only Memory) (not shown) of the control unit 45.

  Thereafter, in the thrust diagnostic apparatus 1 with the calibration function, a normal power mechanism (not shown) for supplying the working air is attached to the air pressure supply port 38 instead of the supply port mounting portion 4a, and the thrust is detected using only the strain sensor 3. Transition to the thrust detection mode for detecting.

  When the thrust detection circuit 45a of the control unit 45 detects the distortion of the yoke 7 based on the supply or discharge of the working air from the power mechanism as the distortion amount in the thrust detection mode, the measurement data obtained in the calibration mode is detected. The thrust corresponding to the amount of strain from the strain sensor 3 is read from the storage unit 50 based on the above. Then, the thrust detection circuit 45a sends the result read from the storage unit 50 to the display unit 51, and displays the thrust corresponding to the distortion of the yoke 7 on the display unit 51.

  In the above configuration, in the calibration mode, the operator attaches the strain sensor 3 to the yoke 7 of the diaphragm valve 5 and attaches the supply port mounting portion 4a to the air pressure supply port 38 of the diaphragm valve 5.

  In the calibration mode, the thrust diagnostic apparatus 1 with the calibration function supplies the trial working air from the air tank 41 in the apparatus main body 2 to the air driving chamber 24 through the supply port mounting portion 4a and is in a fully closed state. Raise body 13. At this time, the thrust diagnostic apparatus with a calibration function 1 calculates the working force that the trial working air pressure gives to the diaphragm 25 based on the pressure data of the air pressure chamber 30 measured by the pressure measuring unit 4 by the calibration circuit 45b. The thrust acting on the stem 14 is calculated based on the power, the spring force of the return spring 31 and the valve opening information.

  At this time, the thrust diagnostic apparatus with a calibration function 1 uses the strain sensor 3 to detect the distortion of the yoke 7 (the distortion caused by the compression in this case) caused by the rise of the valve body 13 in the fully closed state. In the calibration circuit 45b, the distortion amount sent from the strain sensor 3 is associated with the calculated thrust based on the valve opening information. Thereby, the calibration circuit 45b can define the amount of distortion of the valve body 13 from the fully closed state to the fully open state by the thrust amount.

  Thereafter, when the valve element 13 is fully opened, the thrust diagnostic apparatus 1 with a calibration function discharges the trial working air from the air driving chamber 24 through the supply port mounting portion 4a, and the valve element 13 in the fully open state is discharged. Lower it. At this time, the thrust diagnostic apparatus with a calibration function 1 calculates the operating force that the trial operating air pressure gives to the diaphragm 25 based on the pressure data of the air pressure chamber 30 measured by the pressure measuring unit 4 by the calibration circuit 45b. The thrust acting on the stem 14 is calculated based on the power, the spring force of the return spring 31 and the valve opening information.

  At this time, the thrust diagnostic apparatus with a calibration function 1 detects the distortion of the yoke 7 (the distortion caused by being pulled in this case) caused by the valve element 13 in the fully opened state as the distortion amount by the strain sensor 3. Then, in the calibration circuit 45b, the strain amount sent from the strain sensor 3 is associated with the calculated thrust based on the valve opening information. Thereby, the calibration circuit 45b can define the amount of strain from the fully open state to the fully closed state of the valve body 13 as a thrust amount.

  Then, the distortion amount defined by these thrust amounts is stored in the storage unit 50 as measurement data, and the calibration mode is terminated.

  After completion of the calibration mode, the operator removes the supply port mounting portion 4a from the air pressure supply port 38 of the air drive chamber 24 in the diaphragm valve 5 and replaces this with a power mechanism normally used for operating the diaphragm valve 5. It is attached to the air pressure supply port 38 of the air driving chamber 24.

  Thus, in the thrust detection mode, when the diaphragm valve 5 is moved up and down by the power mechanism and the yoke 7 is distorted, the thrust diagnostic apparatus 1 with a calibration function detects this distortion as a distortion amount.

  Thereby, the thrust detection circuit 45a reads out the thrust corresponding to the distortion amount from the measurement data created in the calibration mode based on the distortion amount detected by the strain sensor 3, and outputs the result to the display unit 51. To do. Thus, the operator can diagnose the thrust in the diaphragm valve 5 by the thrust displayed on the display unit 51.

  Incidentally, in this embodiment, although the case where the thrust read from the storage unit 50 based on the strain amount from the strain sensor 3 is displayed on the display unit 51 has been described, the present invention is not limited to this. The thrust read from the storage unit 50 based on the strain amount from the strain sensor 3 may be sent to a diagnostic device (not shown).

  In this case, the diagnostic device can determine whether or not the thrust detected by the thrust diagnostic device with calibration function 1 is normal, and display the determination result on a predetermined display unit. Further, when the diagnostic device determines that the thrust is abnormal, it can be notified by an alarm lamp, an alarm buzzer, a voice synthesizer, or the like.

  According to the above configuration, in the present embodiment, the measurement data in which the thrust acting on the stem 14 is associated with the amount of strain detected by the strain sensor 3 is stored in the storage unit 50 in advance. The thrust of the stem 14 can be detected from the strain of the yoke 7 only by attaching the strain sensor 3 to the stem 7. Thus, the thrust of the stem 14 can be diagnosed with a simpler configuration than in the prior art.

  In the present embodiment, the distortion of the yoke 7 can be calibrated by associating the thrust acting on the stem 14 with the amount of distortion detected by the strain sensor 3. Therefore, if this calibration result is used in the thrust diagnostic apparatus 1 with the calibration function, the thrust of the stem 14 can be accurately detected from the distortion of the yoke 7 only by detecting the distortion of the yoke 7 in the thrust diagnostic apparatus 1 with the calibration function. Thus, the thrust of the stem 14 can be diagnosed with a simpler configuration than in the prior art.

  In addition, this invention is not limited to this embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above-described embodiment, the case where the diaphragm valve 5 is used in which the stem 14 is lowered by the spring force of the return spring 31 so that the valve body 13 is fully closed is described. The invention is not limited to this, and a diaphragm valve is used in which the pneumatic chamber 30 and the spring chamber 32 are provided upside down, and the stem 14 is lowered by the supply of working air so that the valve body 13 is fully closed. Also good. In the embodiment described above, the diaphragm valve 5 is used as the air driven valve, but various air driven valves such as a cylinder type air driven valve may be used.

  Further, in the above-described embodiment, the case where the thrust diagnostic device 1 with the calibration function in which the thrust detection device 40a and the calibration device 40b are integrated is used as the thrust detection device and the calibration device. The invention is not limited to this, and the thrust detection device 40a that executes the thrust detection mode and the calibration device 40b that executes the calibration mode may be configured separately.

  It should be noted that the present invention can be used not only for an air driven valve alone but also for other functions such as a part of a diagnostic device.

It is a basic diagram which shows the whole structure of the thrust diagnostic apparatus with a calibration function in this invention, and a diaphragm valve using the same. It is a block diagram which shows the structure of the thrust diagnostic apparatus with a calibration function. It is a graph which shows the displacement of the spring force of the return spring with respect to the degree of opening and closing of a valve body, and the operation force given by trial operation air pressure. It is a graph which shows the displacement of the distortion amount in a yoke with respect to the opening / closing degree of a valve body.

Explanation of symbols

1 Thrust diagnostic device with calibration function 3 Strain sensor (strain detection means, acquisition means)
4 Pressure measurement unit 5 Diaphragm valve (air driven valve)
7 York
13 Disc
14 stem
24 Air drive room
25 Diaphragm
31 Return spring (return elastic means)
40a Thrust detector
40b Calibration device
41 Air tank (supply / discharge means)
42 Compressor (supply / discharge means)
45 Control unit (calibration means)
46 Compressor drive (supply / discharge means)
50 storage

Claims (2)

  An air driving chamber provided with a diaphragm that is displaced by a return elastic means and an operating air pressure, a yoke that is connected to the air driving chamber and through which a stem that is linked to the diaphragm is inserted, and according to the advance and retreat of the stem In a thrust detecting device for detecting thrust in an air driven valve having a valve body that opens and closes, a strain detecting means for detecting a distortion of a yoke generated in accordance with advancement and retreat of the stem, pressure data of the air driven chamber, Storage means for storing in advance measurement data in which the amount of strain detected by the strain detection means is associated with the thrust acting on the stem calculated based on the elastic force of the return elastic means. A thrust detecting device for an air driven valve. An air driving chamber provided with a diaphragm that is displaced by a return elastic means and an operating air pressure, a yoke that is connected to the air driving chamber and through which a stem that is linked to the diaphragm is inserted, and according to the advance and retreat of the stem A thrust detecting device calibrating device that detects thrust in an air driven valve having a valve body that opens and closes by a distortion of the yoke, and obtains the distortion of the yoke as the working air pressure changes as a strain amount Obtaining means for supplying trial operating air into the air driving chamber, supplying and discharging means for discharging the trial working air in the air driving chamber, and pressure measuring means for measuring pressure data of the air driving chamber And calculating the thrust acting on the stem based on the pressure data of the air driving chamber and the elastic force of the return elastic means, and obtaining the strain acquired by the acquisition means. Calibration apparatus air driven valves, characterized in that it comprises a calibratable calibration means the distortion of the yoke by associating the thrust.

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