JP2012185145A - Measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring apparatus which detects a change in an interval with a rod body using a non-contact distance sensor and, based on it, measures the operation state of a rod body.SOLUTION: The operation state of a rod body is measured based on the detection signal of a non-contact distance sensor which is arranged so as to face the surface of a rod body moving in an axis direction in a non-contact state and detects a change in a distance with the surface. In the configuration, from a change state of the distance, movement start and stop positions of the rod body, and movement time and timing thereof can be accurately determined, which in turn allows movement amount and speed of the rod body in the axis direction to be obtained.

Description

  The present invention relates to a measuring apparatus for detecting a change in the interval between the sensor and the rod body by a non-contact distance sensor arranged close to the surface of the rod body and measuring the operating state of the rod body based on the change. It is.

  One of the necessary information for diagnosing the soundness of an electric valve is information related to the movement of the valve stem. In other words, the valve stem transmits the rotational force on the motor side as the opening / closing driving force of the valve body, and information on its movement uses the moving speed, moving amount, moving time, moving timing, etc. of the valve stem. This is an important factor when diagnosing matters related to the function and deterioration of the motorized valve.

  By the way, as a method for acquiring information related to such displacement of the valve stem, for example, a measuring rod type acquisition method (see Patent Document 1 and Patent Document 2) or a wire type acquisition method (see Patent Document 3) has been proposed. Yes.

  The measuring rod type acquisition method is such that one end of a measuring rod arranged so as to be movable in the axial direction of the valve stem is brought into contact with the top of the valve stem, and displacement information (moving direction, moving speed, moving amount) of the valve rod. Etc.) is obtained based on the displacement of the measuring rod following the movement of the valve stem.

  In the wire acquisition method, one end of the wire is fixed to the top of the valve stem, and the other end is connected to the pulley of the encoder attached to the valve stem housing, and the amount of displacement of the wire that follows the displacement of the valve stem is determined. The rotation amount of the pulley is detected by the encoder, and the detected value is output as a signal corresponding to the displacement amount of the valve stem.

Japanese Patent Laid-Open No. 7-4549 Japanese Utility Model Publication No. 6-82483 JP-A-2-307033 JP 2010-85105 A

  However, in each of the above acquisition methods, it is necessary to open a part of the motor-operated valve and install a measuring rod, a wire, or a distance measuring means in the measurement work for acquiring the movement information of the valve rod. There are restrictions on the installation work of the measuring rods and the like, such as requiring an operator with expertise in the motorized valve for the installation work.

  In addition, when a part of the motor-operated valve is opened in this manner, the function of the motor-operated valve is stopped by opening the motor-operated valve.Therefore, the measurement work is time-constrained from the viewpoint of ensuring the operation of the piping system equipped with the motor-operated valve. is there.

  It is considered that these problems are caused by opening the valve stem cover in order to acquire movement information of the tip portion of the valve stem.

  Therefore, from this point of view, it is conceivable that the information regarding the movement of the valve stem is acquired from the outside of the motor-operated valve without disassembling the motor-operated valve, that is, without opening the valve stem cover. As an example of such a measurement technique, Patent Document 4 discloses that a marking point is provided on the surface of the externally exposed portion of the valve stem, and this marking point is photographed with a photographing device arranged in a non-contact state on the motorized valve. There has been proposed a technique for acquiring information related to movement of a valve stem by performing image processing on a signal output from a photographing apparatus.

  According to such a method for acquiring movement information of the valve stem by “imaging analysis”, since the information can be acquired without disassembling the motor-operated valve, the problem in the acquisition method as described above is solved as much as possible. This is considered to be an extremely useful technique.

  However, on the other hand, in setting such as setting the distance between the camera and the valve stem that is the subject or the relative position between them, it takes time and effort to ensure illumination, secure installation space, and avoid interference with the surrounding area. To do. In addition, since information is acquired by photographing with the photographing device, there is a risk that measurement accuracy may be reduced when distortion occurs in the lens image or when the valve stem slightly vibrates.

  SUMMARY OF THE INVENTION The present invention has been made with the object of providing a measuring apparatus capable of reliably measuring the displacement of a rod body with high accuracy without being restricted by the measurement timing or the like.

  In the present invention, the following specific configuration is adopted as specific means for solving the above-described problems.

  In the measuring apparatus according to the first invention of the present application, an eddy current sensor including a coil that generates a high-frequency magnetic field is disposed to face the surface of a conductive rod that moves in an axial direction in a non-contact state, and It is characterized in that the impedance of the coil that changes in accordance with a change in the distance between the rod and the eddy current sensor or a change in the shape of the rod or a physical quantity corresponding to the impedance is measured.

  Here, the change in the distance between the rod and the eddy current sensor is a change in the distance between the surface of the rod and the eddy current sensor facing the surface (that is, a change in the radial direction of the rod). For example, when the rod body vibrates in the radial direction and the distance to the eddy current sensor changes, or the screw is engraved on the surface of the rod body, and along with the movement of the rod body in the axial direction, This is a case where the distance between the rod and the eddy current sensor changes corresponding to the unevenness of the thread.

  In addition, although it does not result from the original operating state of such a rod or the shape for exhibiting a specific function, for example, the rod is bent as a cause of changing the distance. When the distance between the rod body and the eddy current sensor changes with the movement in the axial direction, or the rod body is supported in an inclined state with respect to the movement direction, and with the movement in the axial direction In some cases, the distance between the rod and the eddy current sensor changes.

  The measuring apparatus according to the second invention of the present application includes a non-contact distance sensor that is disposed so as to face the surface of the rod body that moves in the axial direction in a non-contact state and detects a change in the distance to the surface. The operating state of the rod is measured based on the detection signal of the non-contact distance sensor.

  Here, the change in the distance between the rod and the non-contact distance sensor is the change in the distance between the surface of the rod and the non-contact distance sensor facing the surface (that is, the change in the radial direction of the rod). For example, when the rod body vibrates in the radial direction and the distance from the non-contact distance sensor changes, screws are engraved on the surface of the rod body, and the rod body moves in the axial direction. Along with this, the distance between the rod and the non-contact distance sensor changes corresponding to the unevenness of the thread.

  In addition to this, as a cause of the change in the distance between the rod body and the non-contact distance sensor, for example, when the rod body is bent or the rod body is supported in a state of being inclined with respect to the moving direction. It may be like that.

  In the measuring apparatus according to the third invention of the present application, in the measuring apparatus according to the second invention, the non-contact distance sensor is constituted by an eddy current sensor including a coil that generates a high-frequency magnetic field, and the rod and The operating state of the rod body is measured based on the impedance of the coil that changes in accordance with the change in the distance of the rod or the shape change of the rod body or a physical quantity corresponding to the impedance.

  In the measurement apparatus according to the fourth invention of the present application, in the measurement apparatus according to the second invention, the non-contact distance sensor is constituted by a capacitance sensor that detects a change in capacitance in an electric field, and The operating state of the rod is measured based on a capacitance value that changes in accordance with a change in the distance from the rod and a change in the shape of the rod.

  In the measuring apparatus according to the fifth invention of the present application, in the measuring apparatus according to the second invention, the non-contact distance sensor is constituted by an ultrasonic sensor having an ultrasonic transmission / reception function, and the ultrasonic sensor The operating state of the bar is measured based on a reciprocating propagation time between the ultrasonic sensor of the transmitted ultrasonic wave and the surface of the bar.

  In a measurement apparatus according to a sixth invention of the present application, in the measurement apparatus according to the second invention, the non-contact distance sensor is constituted by a laser sensor having a function of transmitting and receiving laser light, and is transmitted from the laser sensor. The operating state of the bar is measured based on the reciprocation time between the laser sensor of the laser beam to be emitted and the surface of the bar.

  In the measuring device according to the seventh invention of the present application, in the measuring device according to the second, third, fourth, fifth or sixth invention, a plurality of the non-contact distance sensors are provided in the circumferential direction of the rod body. It is characterized by the arrangement.

  In the measuring device according to the eighth invention of the present application, in the measuring device according to the second, third, fourth, fifth or sixth invention, a plurality of the non-contact distance sensors are provided in the axial direction of the rod body. It is characterized by the arrangement.

  According to the measuring apparatus according to the present invention, the following effects can be obtained.

(A) Measuring device according to the first invention of the present application When the eddy current sensor is disposed to face the surface of the rod body in a non-contact state and a high-frequency current is passed through the coil in this state, the electromagnetic induction causes the above Eddy current flows on the surface of the rod.

  And, when the distance between the surface of the rod and the eddy current sensor facing the rod changes due to vibration or shape change of the rod, the impedance of the coil changes corresponding to the change in the distance, This change in impedance can be acquired as an impedance waveform or as a physical quantity corresponding to the impedance, for example, a voltage waveform (signal waveform) converted into a voltage.

  In the acquired signal waveform, the signal waveform when the rod is moving in its axial direction (when the rod vibrates in the radial direction, etc.), and the signal waveform when the rod is stopped are Since these can be clearly identified, it is possible to accurately determine the movement start / stop position of the rod body and the movement time / timing by both of them, and in the axial direction of the rod body. The amount and speed of movement can be obtained by calculation. In addition, it is possible to know the presence or absence or degree of bending or inclination of the rod.

(B) The measuring device according to the second invention of the present application The non-contact distance sensor is arranged to face the surface of the rod body in a non-contact state, and the non-contact distance sensor is arranged to measure the distance between the surface of the rod body and the non-contact distance sensor. By detecting the change, it is possible to clearly distinguish the state in which the rod is moving in the axial direction and the case in which the rod is stopped from the change state of the distance. As a result, it is possible to accurately determine the movement start / stop position of the rod and the movement time / timing, and by extension, the amount of movement and the movement speed of the rod in the axial direction can be obtained by calculation. In addition, it is possible to know the presence or absence or degree of bending or inclination of the rod.

(C) The measuring device according to the third invention of the present application When the eddy current sensor is disposed so as to face the surface of the rod body in a non-contact state and a high-frequency current is passed through the coil in this state, the electromagnetic induction causes the above-mentioned Eddy current flows on the surface of the rod. And, when the distance between the surface of the rod and the eddy current sensor facing the rod changes due to vibration or shape change of the rod, the impedance of the coil changes corresponding to the change in the distance, This change in impedance can be acquired as an impedance waveform or as a physical quantity corresponding to the impedance, for example, a voltage waveform (signal waveform) converted into a voltage.

  In the acquired signal waveform, the signal waveform when the rod is moving in its axial direction (when the rod vibrates in the radial direction, etc.), and the signal waveform when the rod is stopped are Since these can be clearly identified, it is possible to accurately determine the movement start / stop position of the rod body and the movement time / timing by both of them, and in the axial direction of the rod body. The amount and speed of movement can be obtained by calculation. In addition, it is possible to know the presence or absence or degree of bending or inclination of the rod.

(D) Measuring apparatus according to the fourth invention of the present application When the capacitance sensor is disposed to face the surface of the rod body in a non-contact state, the rod body moves in the axial direction, changes in shape or diameter. When the distance between the surface of the rod and the capacitance sensor changes due to the vibration in the direction, the capacitance detected by the capacitance sensor changes corresponding to the change in the distance.

  And since the change state of the capacitance when the rod is moving in the axial direction and the change state of the capacitance when the rod is stopped can be clearly identified. With both of these, it is possible to accurately determine the movement start / stop position of the rod body and the movement time / timing, and by calculation, the amount of movement and the movement speed of the rod body in the axial direction can be obtained. it can. In addition, it is possible to know the presence or absence or degree of bending or inclination of the rod.

(E) A measuring device according to the fifth invention of the present application When the ultrasonic sensor is arranged to face the surface of the rod body in a non-contact state, the rod body moves in the axial direction, changes in shape, or in the radial direction. When the distance between the surface of the rod body and the ultrasonic sensor changes due to vibration to the ultrasonic wave, the ultrasonic wave travels back and forth between the ultrasonic sensor and the surface of the rod body in response to the change in the distance. Time changes.

  And since the change state of the round-trip propagation time when the rod is moving in the axial direction and the change state of the round-trip propagation time when the rod is stopped can be clearly distinguished. With both of these, it is possible to accurately determine the movement start / stop position of the rod body and the movement time / timing, and by calculation, the amount of movement and the movement speed of the rod body in the axial direction can be obtained. it can. In addition, it is possible to know the presence or absence or degree of bending or inclination of the rod.

  When measuring the distance from the rod with an ultrasonic sensor, the ultrasonic wave propagates in the air, but the propagation speed of this ultrasonic wave in the air changes according to the air temperature. is there. Therefore, in order to ensure the measurement accuracy of the distance measurement by the ultrasonic sensor, the propagation time of ultrasonic waves acquired by the measurement (that is, the measurement distance) is corrected based on the temperature change.

(F) Measuring device according to the sixth invention of the present application When the laser sensor is disposed opposite to the surface of the rod body in a non-contact state, the rod body moves in the axial direction, changes in shape or in the radial direction. When the distance between the surface of the rod and the laser sensor changes due to the vibration of the laser, the reciprocation time of the laser beam between the laser sensor and the surface of the rod changes in response to the change in the distance. .

  And the change state of the round trip time of the laser beam when the rod is moving in the axial direction and the change state of the round trip time of the laser beam when the rod is stopped can be clearly distinguished Therefore, it is possible to accurately determine the movement start / stop position of the rod body and the movement time / timing by both of them, and further, the amount of movement and the movement speed of the rod body in the axial direction. Can be obtained by calculation. In addition, it is possible to know the presence or absence or degree of bending or inclination of the rod.

(G) The measuring device according to the seventh invention of the present application By arranging a plurality of the non-contact distance sensors in the circumferential direction of the rod body, for example, when the rod body is curved, In addition, when the axis of the rod body is inclined with respect to the moving direction of the rod body, it is possible to know the inclination direction, and information on the bending direction or the inclination direction of the rod body is obtained by the non-contact distance sensor. By reflecting the distance measurement, further improvement in the measurement accuracy of the measuring device can be expected.

  Further, by calculating each of the measurement values of the plurality of non-contact distance sensors, the noise signal can be removed and the measurement signal can be clarified, and the reliability of the measurement value is ensured. For example, each non-contact distance sensor performs distance measurement, and differential processing is performed on the measurement signals of each of the non-contact distance sensors, so that common noise in the measurement signal can be removed. High measurement is possible.

(H) Measuring device according to the eighth invention of the present application By arranging a plurality of the non-contact distance sensors in the axial direction of the rod, the moving direction of the rod can be known, and the moving direction of the rod By reflecting the information on the distance measurement by the non-contact distance sensor, further improvement in the measurement accuracy of the measuring device can be expected.

  Further, by calculating each of the measurement values of the plurality of non-contact distance sensors, the noise signal can be removed and the measurement signal can be clarified, and the reliability of the measurement value is ensured. For example, each non-contact distance sensor performs distance measurement, and differential processing is performed on the measurement signals of each of the non-contact distance sensors, so that common noise in the measurement signal can be removed. High measurement is possible.

As described above, according to the measuring device of each invention of the present application, since the operating state of the rod body is measured in a non-contact state,
(A) Compared to measuring the displacement of the rod end,
(A-1) It is not necessary to open a part of the device provided with the rod body and arrange the measuring device, and the measurement work can be simplified and speeded up.
(A-2) Since the displacement of the rod can be measured without being restricted by this even when the rod is in operation, the degree of freedom of measurement time is improved.
Etc. are obtained.

(B) Compared to an optical measuring device using a camera,
(B-1) The setting of the measuring device with respect to the rod side is easy, and the simplification and speeding up of the measuring work is promoted.
(B-2) The measurement accuracy is not affected by the distortion of the lens image or the minute vibration of the rod, and a higher accuracy measurement is possible.
Etc. are obtained.

It is explanatory drawing of the measuring method of the valve-rod operating state of a motor operated valve using the measuring apparatus which concerns on embodiment of this invention. It is 1st measurement form explanatory drawing by an eddy current sensor. It is 2nd measurement form explanatory drawing by an eddy current sensor. It is explanatory drawing of the 3rd measurement form by an eddy current sensor. It is explanatory drawing of the impedance waveform of the valve-rod opening operation start position vicinity acquired by an eddy current sensor. It is explanatory drawing of the impedance waveform of the valve-rod opening operation stop position vicinity acquired by an eddy current sensor. It is explanatory drawing of the impedance waveform of the opening operation start position vicinity of the valve stem with a screw | thread acquired by an eddy current sensor. It is explanatory drawing of the acquisition method of the moving speed of the valve stem using an impedance waveform. It is explanatory drawing of an impedance waveform in case a valve stem has a curve. It is explanatory drawing of an impedance waveform in case a valve stem has inclination. It is explanatory drawing at the time of arrange | positioning multiple eddy current sensors to the circumferential direction of a valve rod. It is explanatory drawing at the time of arrange | positioning multiple eddy current sensors to the axial direction of a valve stem. It is explanatory drawing of the measuring method of the valve stem operating state in an air operating valve. It is explanatory drawing of the operation state of an air operation valve. It is arrangement | positioning explanatory drawing of the electrostatic capacitance sensor to the yoke part of a motor operated valve. It is XVI-XVI sectional drawing of FIG. It is a wave form diagram of a sensor output voltage acquired by a capacitance sensor arranged on one side of a valve stem. It is a wave form diagram of a sensor output voltage acquired by a capacitance sensor arranged on the other side of a valve stem. It is a graph which shows the distance relationship between an electrostatic capacitance sensor and a valve stem in a fully open position and a fully closed position of an electric valve. It is a conceptual explanatory drawing in the case of acquiring the inclination degree of a valve stem using a capacitance sensor.

A: First Embodiment FIG. 1 shows a valve stem 6 (a “rod body” in the claims) using an eddy current sensor 10 constituting a measuring apparatus according to a first embodiment of the present invention. 1 shows a motor-operated valve 1 whose displacement is measured.

  The eddy current sensor 10 is one of the “non-contact distance sensors” in the claims, and has a conventionally known structure including a coil that receives a high-frequency current and generates a high-frequency magnetic field. When a conductor (in this embodiment, the valve stem 6 corresponds to this) exists in the high-frequency magnetic field, an eddy current is generated on the surface of the conductor by magnetic induction, and the impedance of the coil changes. The impedance of the coil changes according to the change in the distance between the coil and the conductor.

  Therefore, if the eddy current sensor 10 is disposed in close proximity to the valve stem 6 and the impedance of the coil is measured and continuously monitored, the change in the distance of the valve stem 6 with respect to the eddy current sensor 10 is changed. (Or a physical quantity corresponding to the impedance, for example, a voltage waveform corresponding to a change in voltage) is obtained (see FIG. 5).

  In order to measure the displacement of the valve stem 6 by the eddy current sensor 10 having the measurement function as described above, the eddy current sensor 10 is opposed to the surface of the valve stem 6 in a close state (that is, in a non-contact state). Here, as an arrangement form of the eddy current sensor 10, as shown in FIG. 2, the eddy current sensor 10 is arranged opposite to the smooth portion 6b of the valve stem 6 (hereinafter referred to as “first arrangement”). As shown in FIG. 3, the eddy current sensor 10 is affixed to the smooth portion 6b of the valve stem 6 with an auxiliary material 7 in which convex portions 71 or concave portions 72 are formed at a predetermined pitch. A form in which the eddy current sensor 10 is arranged in a state of facing the material 7 (hereinafter referred to as “second arrangement form”) and a screw part 6a of the valve stem 6 as shown in FIG. Assuming form (hereinafter referred to as “third arrangement form”) .

  Here, the impedance waveform obtained by the measurement by the eddy current sensor 10 will be described.

  In the motor-operated valve 1, during the movement, the valve stem 6 receives vibrations on the motor 2 or the valve drive unit 4 side to generate radial vibrations, whereby the surface of the valve stem 6 and the eddy current sensor 10 are generated. The distance of will change.

  While the valve stem 6 is stopped, vibration caused by the operation of the valve stem 6 (that is, vibration on the motor 2 or the valve drive unit 4 side) is not input to the valve stem 6, but this operation The vibration other than the vibration caused by the above, for example, the vibration on the pipe side provided with the motor-operated valve 1 is always input to the valve stem 6 side. However, this vibration level can be classified as compared with the vibration level caused by the operation of the valve stem 6, and the measurement of the operation state of the valve stem 6 and the measurement result are dealt with in the diagnosis regarding the operation of the motor-operated valve 1. obtain.

  Further, when the valve stem 6 is bent or when the axis of the valve stem 6 is inclined with respect to the moving direction due to uneven wear of the support portion of the valve stem 6, Along with the operation, the distance between the surface of the valve stem 6 and the eddy current sensor 10 changes.

  As described above, when the distance between the surface of the valve stem 6 and the eddy current sensor 10 changes, the impedance of the coil in the eddy current sensor 10 changes corresponding to the change in the distance. Based on this, it is possible to know the movement state of the valve stem 6 and the like.

  For example, even when the surface of the valve stem 6 is scratched or when a part of the threaded portion 6a is chipped, these scratches or chips are not removed from the surface of the valve stem 6 and the eddy current sensor 10. Therefore, the impedance of the coil in the eddy current sensor 10 changes and is detected.

Hereinafter, the measurement of the operating state of the valve stem 6 using the eddy current sensor 10 and how to use the impedance waveform obtained by the measurement will be described with reference to FIGS.

A: About FIG. 5 FIG. 5 shows the motor current waveform in the vicinity of the starting position of the opening operation of the impedance waveform obtained by the measurement in which the eddy current sensor 10 is arranged to face the smooth portion 6b of the valve stem 6. It is shown with.

  According to the impedance waveform, when the opening operation of the valve stem 6 is started, the impedance suddenly increases and changes with a predetermined magnitude. By checking this sudden change portion of the impedance, the valve stem 6 6 can be accurately recognized as the starting point of the opening operation (ie, the movement timing of the valve stem 6).

  In the motor current waveform, the starting point of the motor 2 can be accurately recognized as a sudden change point of the waveform. Therefore, the operation delay time of the valve stem 6 can be known by associating the motor starting point with the opening operation start point of the valve stem 6.

B: FIG. 6 FIG. 6 shows the waveform of the impedance waveform obtained by the measurement in which the eddy current sensor 10 is disposed facing the smoothing portion 6b of the valve stem 6 in the vicinity of the stop position of the opening operation. It is shown together with the waveform.

  According to the impedance waveform, when the opening operation of the valve stem 6 is stopped, the impedance rapidly decreases and remains in the decreased state. By checking this sudden change portion of the impedance, Thus, the open operation stop point 6 (that is, the movement stop timing of the valve stem 6) can be accurately recognized.

  In the motor current waveform, the stop point of the motor 2 can be accurately recognized as a sudden change point of the waveform. Therefore, the coasting time of the valve stem 6 can be known by associating the motor stop point with the opening stop point of the valve stem 6.

C: FIG. 5 and FIG. 6 As described above, the opening operation start point of the valve stem 6 is acquired in the impedance waveform in FIG. 5, and the opening operation stop point of the valve rod 6 is acquired in the impedance waveform of FIG. The travel time of the valve stem 6 can be accurately known from the open operation start point and the open operation stop point.

D: About FIG. 7 FIG. 7 shows the waveform of the impedance waveform obtained by the measurement in which the eddy current sensor 10 is placed facing the screw portion 6a of the valve stem 6 in the vicinity of the stop position of the opening operation. This is shown together with the waveform and corresponds to FIG.

  In the impedance waveform of FIG. 7, the valve rod opening operation start point can be accurately recognized by the sudden change in impedance at the valve rod opening operation starting point, as in the case shown in FIG. Further, the shape of this impedance waveform is represented as a regular wavy line having a large amplitude corresponding to each of the crest 61 and the trough 62 of the threaded portion 6a of the valve stem 6, as shown in FIG. Therefore, for example, the change in impedance during the movement of the valve stem 6 is more clearly recognized than when the eddy current sensor 10 is arranged and measured on the smooth portion 6b of the valve stem 6 (see FIG. 5). can do.

E: About FIG. 8 FIG. 8 is an enlarged view of a part of the impedance waveform in FIG. 7, and is a synchronized display of the valve lift waveform acquired by a lift sensor (not shown). As described above, this impedance waveform is represented as a regular waveform having a large amplitude corresponding to each of the crest 61 and the trough 62 of the threaded portion 6a of the valve stem 6.

  The time “ΔT” of one pitch of the impedance waveform can be obtained from the impedance waveform. Further, the width dimension “ΔL” of one pitch of the screw portion 6a is known. Therefore, the moving speed of the valve stem 6 can be obtained by calculation based on the time “ΔT” and the width dimension “ΔL”.

  Further, the amount of movement of the valve stem 6 can be obtained by calculation from the width dimension “ΔL” and the wave number of the impedance waveform between the opening start point of the valve stem 6 and the opening stop point. .

F: About FIG. 9 FIG. 9 shows the impedance waveform when the eddy current sensor 10 is arranged in the smoothing portion 6b of the valve stem 6 and the valve stem 6 is bent. is there. Since this impedance waveform appears as a curved shape corresponding to the bent shape of the valve stem 6, the presence of the impedance waveform can be easily known, and the reliability of the valve stem 6 can be determined based on the magnitude (degree) of the bend. It is also possible to determine whether or not there is a need for replacement.

G: About FIG. 10 FIG. 10 shows an impedance waveform when the eddy current sensor 10 is arranged in the smoothing portion 6b of the valve stem 6 and when the valve stem 6 is inclined. Since this impedance waveform appears in an inclined line shape corresponding to the inclination of the valve stem 6, its presence can be easily recognized, and the support of the valve stem 6 is supported based on the magnitude (degree) of the inclination. It is also possible to determine the size of the partial wear of the portion and whether or not the support portion needs to be replaced.

I: Others (I-1) Fixing of the eddy current sensor 10 As shown in FIG. 1, the eddy current sensor 10 is, for example, the electric motor 1 as well as the fixing method of directly attaching to the yoke 3 of the motor-operated valve 1. A fixing method in which the valve 1 is fixed to the floor side without contact is conceivable.

  In the former case, that is, when the eddy current sensor 10 is directly attached to the yoke 3 of the motor-operated valve 1 and the operating state of the valve stem 6 is measured by the eddy current sensor 10, the valve stem 6 is operated. The vibration of the valve stem 6 itself and the vibration of the eddy current sensor 10 itself by the yoke 3 are combined. Therefore, since the impedance waveform acquired by the measurement by the eddy current sensor 10 has an amplitude corresponding to the combined vibration, for example, the operation start point or the operation stop of the valve stem 6 based on the impedance waveform. It becomes easy to confirm the point or hammer blow operation.

  Further, according to the configuration in which the eddy current sensor 10 is directly attached to the yoke 3 of the motor-operated valve 1 in this way, the eddy current sensor 10 can be fixed to the yoke 3 side via a relatively small support member, etc. Simplification of the structure is promoted.

  In the latter case, that is, when the operating state of the valve stem 6 is measured by the eddy current sensor 10 fixed to the floor surface in a non-contact manner with the motor-operated valve 1, for example, the eddy current sensor 10 and the eddy current sensor 10 are attached. The influence of backlash and the like between the support members to be applied can be avoided as much as possible to the measurement of the eddy current sensor 10, and a highly accurate measurement is possible.

Further, since the eddy current sensor 10 is configured to perform measurement without contact with the valve stem 6, for example, even when the valve stem or the yoke is hot, measurement can be performed without being affected by this, and the reliability thereof is high. However, when this eddy current sensor 10 is fixed to the floor surface side without contact with the motor-operated valve 1 as described above, the effect becomes more remarkable.

(I-2) Other Arrangement Examples of Eddy Current Sensor 10 In the above embodiment, one eddy current sensor 10 is arranged in a state where the valve stem 6 is brought close to the eddy current sensor 10, but the arrangement is limited to such a configuration. Instead, a plurality of the eddy current sensors 10 are prepared, and a circumferential arrangement configuration in which the eddy current sensors 10 are arranged in the circumferential direction of the valve stem 6 or an axial arrangement configuration in which the valve stem 6 is arranged in the axial direction is provided. It can also be adopted.

(I-2-1) Circumferential Arrangement Configuration of Eddy Current Sensor 10 FIG. 11 shows two eddy current sensors 10 as valve shafts 6 as an example of the circumferential arrangement of a plurality of eddy current sensors 10. In the same position in the axial direction, the valve rod 6 is arranged in a non-contact state with a crossing angle of approximately 90 ° in the circumferential direction.

  In this way, a plurality (two in this example) of the eddy current sensors 10 are arranged in the circumferential direction of the valve stem 6, and the distance from the surface of the eddy current sensor 10 is measured by each of the eddy current sensors 10. When configured, the following specific effects can be obtained.

  (A) Two (plural) eddy current sensors 10 are arranged, the operating state of the valve stem 6 is measured by each eddy current sensor 10, and the measurement data is differentially processed. When the two eddy current sensors 10 are arranged close to each other, the original measurement signal can be further clarified by removing the electromagnetic noise or the common noise due to the vibration of the sensor itself. High-precision measurement is possible.

  (B) By arranging two eddy current sensors 10 with a crossing angle of approximately 90 ° in the circumferential direction of the valve stem 6, for example, when the valve stem 6 is bent, the bending direction is Further, when the axis of the valve stem 6 is inclined with respect to the moving direction of the valve stem 6, the direction of the inclination can be known, respectively, and information regarding the bending direction or the inclination direction of the valve stem 6 can be obtained. By reflecting it in the distance measurement by the contact distance sensor 10, the accompanying effect that the measurement accuracy of the measuring device is further improved can be obtained.

  In this case, the crossing angle of the two eddy current sensors 10 is not limited to “substantially 90 °” and can be set to any crossing angle. However, the incidental effect can be obtained more accurately. From this point of view, it can be said that it is optimal to set the crossing angle to “approximately 90 °”.

(I-2-2) Axial Arrangement Configuration of Eddy Current Sensor 10 FIG. 12 shows two eddy current sensors 10 as valve shafts 6 as an example of an axial arrangement configuration of a plurality of eddy current sensors 10. Is shown in a non-contact state with a predetermined interval in the axial direction of the valve stem 6 at the same circumferential position.

  In this way, a plurality (two in this example) of the eddy current sensors 10 are arranged in the axial direction of the valve stem 6, and the distance from the surface of the eddy current sensor 10 is measured by each of the eddy current sensors 10. When configured, the following specific effects can be obtained.

  (A) Two (plural) eddy current sensors 10 are arranged, the operating state of the valve stem 6 is measured by each eddy current sensor 10, and the measurement data is differentially processed. When the two eddy current sensors 10 are arranged close to each other, the original measurement signal can be further clarified by removing the electromagnetic noise or the common noise due to the vibration of the sensor itself. High-precision measurement is possible.

  (B) Since the two eddy current sensors 10 are arranged at predetermined intervals in the axial direction of the valve stem 6, the movement direction of the valve stem 6 can be known, and information on the movement direction of the valve stem 6 is obtained. Is reflected in the distance measurement by the non-contact distance sensor 10 to further improve the measurement accuracy of the measuring apparatus.

  In this case, the distance between the two eddy current sensors 10 in the axial direction of the valve stem 6 increases the resolution when the measured values measured by the eddy current sensors 10 are processed, thereby achieving high accuracy. From the viewpoint, it is better that the interval is as small as possible, and it is ultimately preferable that the distance is almost zero (that is, substantially the same position in the axial direction).

(I-2-3) Synthetic Arrangement Configuration of Eddy Current Sensor 10 As an arrangement configuration of the eddy current sensor 10, in addition to the circumferential arrangement configuration and the axial arrangement configuration, a synthesis obtained by synthesizing these two arrangement configurations. An arrangement is conceivable. That is, two or more eddy current sensors 10 are arranged close to each other at different positions in the axial direction of the valve stem 6 and with a predetermined crossing angle in the circumferential direction of the valve stem 6. According to such an arrangement configuration, it is possible to simultaneously obtain a specific effect by the circumferential arrangement configuration and a specific effect by the axial arrangement configuration.

  Further, even when the circumferential arrangement or the axial arrangement of the plurality of eddy current sensors 10 cannot be performed due to, for example, structural reasons on the electric valve side, the eddy current sensors 10 are combined and arranged, The restriction on the arrangement position of the eddy current sensor 10 can be eliminated, and the layout flexibility of the eddy current sensor 10 is improved accordingly.

  Furthermore, according to the combined arrangement configuration, for example, the X-axis direction and the Y-axis direction (that is, two directions orthogonal to the circumferential direction of the valve rod 6) and the Z-axis direction (that is, the valve rod 6) In addition to the information in the axial direction, information related to the movement time of the valve stem 6 can be obtained, and four-dimensional management of the valve stem 6 can be performed based on these pieces of information.

(I-3) Trend management of the valve stem 6 By continuously monitoring data relating to the operating state of the valve stem 6 acquired by measurement with the eddy current sensor 10, or with a current sensor or yoke stress sensor By comparison, it is possible to acquire the operating tendency of the valve stem 6 and take necessary measures as necessary. For example, the long tendency of the operation delay time of the valve stem 6 (see FIG. 5) becomes, for example, a judgment material for determining the worn state of the stem nut and its replacement timing.

(I-4) Application of the Invention to an Air Actuated Valve FIG. 13 shows a state in which the actuated state of the valve rod 101 of the air actuated valve 100 is measured by an eddy current sensor 103 attached to the yoke 102. The valve rod 101 of the air-operated valve 100 is often used as a flow rate adjusting valve. Therefore, as shown in FIG. 14, the operation of repeating the opening operation and the closing operation is a basic operation. In this case, according to the eddy current sensor 10, it is possible to accurately know the operation start point and the operation stop point in the opening operation of the valve rod 101, and the operation start point and the operation stop point in the closing operation. This is suitable as a method for measuring the operating state of the air-operated valve 100, such as being able to acquire the amplitude and cycle of the hunting operation or the amplitude and cycle of the hunting operation.

B: Second Embodiment In the measuring device according to the second embodiment of the present invention, the measuring device according to the first embodiment includes the eddy current sensor 10 for measuring the operating state of the valve stem 6. On the other hand, as shown in FIG. 15, a capacitance sensor 20 is provided.

  The capacitance sensor 20 (hereinafter referred to as “20A to 20F” as necessary) functions as a non-contact distance sensor like the eddy current sensor 10, and is shown in FIG. As described above, the main body portion 22 containing the electric product and the rod-shaped electrode portion 21 containing the electrode at the tip portion are configured, and the tip surface of the electrode portion 21 is in a non-contact state with the surface of the valve stem 6. Are arranged close to each other. The capacitance sensor 20 detects a change in capacitance within the electric field generated in the electrode portion 21. That is, if the relative distance between the valve stem 6 and the electrode portion 21 changes due to the movement of the valve stem 6 in the axial direction, the shape change of the valve stem 6 or the vibration in the radial direction, the change in the relative distance. Corresponding to the capacitance in the electric field changes. This capacitance change is converted into a voltage corresponding to the change in the relative distance by a voltage conversion circuit, for example, and this is detected, and the operating state of the valve stem 6 is measured based on the detected voltage signal It is.

  By the way, the number of the capacitive sensors 20 and the arrangement position of the capacitance sensor 20 with respect to the valve stem 6 can be arbitrarily set as necessary. In this embodiment, “detection of the inclination of the valve stem 6”, which will be described later. , And two capacitance sensors 20A and 20B (the minimum number necessary for detecting the inclination of the valve stem 6) are used as shown by solid lines in FIG. 15 and FIG. The intersection angle α between these two points (for example, a point corresponding to the axial center of the valve stem 6 at a position directly above the gland packing presser in the fully closed state is defined as a reference point P, and one of the capacitance sensors 20A passing through the reference point P The angle between the directional line “La” and the directional line “Lb” of the other capacitance sensor 20B passing through the reference point P) is set to “about 90 °”.

  Note that the crossing angle α of the two capacitance sensors 20 is “180 °” because it is necessary to detect two tilt components in the X-axis direction and the Y-axis direction when the movement direction of the valve stem 6 is the Z-axis. "Near" should be avoided, and can be arbitrarily set as long as it is within an angular range other than near "180 °". Therefore, in the example of the arrangement of the capacitance sensors 20A to 20F illustrated in FIG. 16, a combination (for example, a combination of 20A and 20F, or a combination of 20B and 20D) on the straight line across the axis of the valve stem 6 is arranged. Any combination other than (combination) can be set arbitrarily.

  Further, the number of the capacitance sensors 20 can be set to one if the “tilt of the valve stem 6” is not taken into consideration, but if the “inclination of the valve stem 6” is taken into account, the electrostatic capacity sensor 20 is electrostatically charged as described above. It is necessary to arrange at least two capacitive sensors 20. However, since the part where the electrostatic capacity sensor 20 can be arranged is limited to the space between the left and right yokes 3 and 3, it is preferable that the number is at most about four in consideration of this space restriction.

The capacitance sensor 20 can also be configured such that the electrode portion 21 can be shielded by a magnetic shield material. Therefore, a plurality of capacitance sensors 20 configured to be shielded as described above are installed. For example, the capacitance sensor actually used according to the purpose of measurement performed using the capacitance sensor 20 or the like. By selecting the number of 20 or the arrangement position,
Selection of the usage mode of the capacitance sensor corresponding to the measurement purpose becomes easy.

  Next, a specific method and the like for diagnosing the presence or absence and the degree of inclination of the valve stem 6 using the capacitance sensor will be described.

  Here, as shown by the solid line in FIG. 16, the two electrostatic capacity sensors 20A and 20B in which the crossing angle α is set to “approximately 90 °” are shown in FIG. The case where it arrange | positions so that it may face and oppose the surface of the said valve stem 6 in the same height position is assumed.

  In this state, a series of operations of moving the valve stem 6 from the fully open position to the fully closed position and further moving from the fully closed position to the fully open position is repeated three times, and the movement of the valve stem 6 in this case Are measured by the capacitance sensors 20A and 20B, and the measurement results are shown in FIGS.

  FIG. 17 shows an output voltage waveform obtained by measurement with one capacitance sensor 20A. According to this output voltage waveform, the voltage level of the “output voltage” is changed from the fully opened position to the fully open position during the closed operation period. As the shift to the closed position is gradually decreased, conversely, during the open operation period, the shift is gradually increased from the fully closed position to the fully opened position. Is the same.

  FIG. 18 shows an output voltage waveform obtained by measurement with the other capacitance sensor 20B. According to this output voltage waveform, the voltage level of the “output voltage” is changed from the fully opened position to the fully open position during the closed operation period. In the open operation period, on the contrary, the voltage level gradually increases and changes gradually in the open operation period. Is the same.

  On the other hand, the “output voltage” is inversely proportional to the distance between the electrode portion 21 of the capacitance sensor and the surface of the valve stem 6 facing the capacitance portion 21, and the greater this distance is (that is, the electrode portion 21 is in the valve stem 6. The voltage level decreases as the distance from the surface increases.

Therefore, when the correlation between the “distance and voltage level” is applied to the measurement by the capacitance sensors 20A and 20B,
(A) When viewed from the direction in which one capacitance sensor 20A is directed, the distance “L1” from the valve stem 6 gradually increases and changes during the closing operation in which the valve stem 6 moves downward (ie, the valve stem 6 The distance “L1” with respect to the valve stem 6 gradually decreases and changes during the opening operation in which the valve stem 6 moves upward (ie, away from one capacitance sensor 20A) (that is, the valve stem 6 is one capacitance sensor). Is approaching 20A),
(B) From the direction of the other capacitance sensor 20B, the distance “L2” from the valve stem 6 gradually decreases and changes during the closing operation in which the valve stem 6 moves downward (that is, the valve stem 6 The distance “L2” from the valve stem 6 gradually increases and changes during the opening operation in which the valve stem 6 moves upward (closer to the other capacitance sensor 20B) (that is, the valve stem 6 changes to the other capacitance sensor). 20B)
(C) The distance “L1” on the one capacitance sensor 20A side and the distance “L2” on the other capacitance sensor 20B side are “increase change” in both the opening operation and the closing operation. It only “decreases” and does not “turn from increasing change to decreasing” or “turn from decreasing change to increasing” during the opening or closing operation.

  From the facts described in (a) to (c) above, it is understood that the valve stem 6 is not bent and deformed and has a straight shape. However, the valve stem 6 is in the direction of its movement line (that is, the motor-operated valve). Therefore, it can be known that the valve rod 6 is moving in this inclined state.

  On the other hand, distances “L1” and “L2” between the electrode portions 21 of the capacitance sensors 20A and 20B and the surface of the valve stem 6 can be obtained by calculation using the output voltages of the capacitance sensors 20A and 20B. . Then, the degree of inclination of the valve stem 6 can be known by the calculation using the acquired distance as described below.

  In FIG. 19, the distances “L1” and “L1” acquired based on the output voltages of the capacitance sensors 20A and 20B (specifically, based on the average value of the measured values in three measurements) are displayed. L2 "is shown as distances" L1a "and" L2a "at the fully open position and distances" L1b "and" L2b "at the fully closed position.

  20 shows the relationship between the distances “L1a”, “L2a”, “L1b”, and “L2b” shown in FIG. 19, and the relative relationship between the valve stem 6 and the capacitance sensors 20A and 20B. Shown below. According to FIG. 20, in the fully opened position, the valve stem 6 is at a distance “L1a” from the capacitance sensor 20A and at a distance “L2a” from the capacitance sensor 20B. However, in the fully closed position, the capacitance sensor 20A is displaced to the position of the distance “L1b”, and the capacitance sensor 20B is displaced to the position of the distance “L2b”. It can be seen that during the closing operation to the closed position, the valve stem 6 has shifted so that its axial center approaches the reference point P. Accordingly, the position of the valve stem 6 in the fully open position (position defined by the distances “L1a” and “L2a”) and the position of the valve stem 6 in the fully closed position (positions defined by the distances “L1b” and “L2b”). ) Can be known to which direction and how much the valve stem 6 is inclined.

  As described above, according to the measurement method using the capacitance sensor 20, whether or not the valve stem 6 is bent or tilted and the degree thereof are determined by the measurement result of the capacitance sensor 20 (that is, the change tendency of the output voltage waveform). Etc.), and facilitating such judgment is extremely useful in diagnosis of a motor-operated valve.

  In this embodiment, as shown in FIGS. 17 and 18, a raw waveform is used as the output voltage of the capacitance sensor. Depending on the purpose of use of the capacitance sensor, the raw waveform may be filtered. It can also be used in a state where differential / integral processing has been performed.

  Further, in this embodiment, as shown in FIG. 15, the capacitance sensor 20 is placed on the floor surface away from the motor-operated valve 1 (the floor surface affected by the vibration of the motor-operated valve 1 or the floor surface not affected by the vibration). However, the present invention is not limited to the configuration in which the capacitance sensor 20 is installed on the floor as described above. For example, the capacitance sensor 20 is connected to the motor-operated valve 1. The installation configuration of the capacitance sensor 20 can be arbitrarily selected in consideration of the surrounding situation of the motor-operated valve 1 or the purpose of using the sensor signal, such as being directly installed on the yoke 3.

  Also in the measuring apparatus in this embodiment, the same operational effects as in the measuring apparatus according to the first embodiment can be obtained.

  In the second embodiment as well, as in the first embodiment, a plurality of the capacitance sensors are provided, and as the arrangement configuration thereof, the circumferential arrangement configuration, the axial arrangement configuration, or the synthesis is provided. Of course, the arrangement configuration can be appropriately selected.

  In addition, as in this embodiment, a method of knowing the presence or absence and the degree of the bending or tilting of the valve stem 6 using a capacitance sensor is not a function and effect peculiar to the capacitance sensor, and is widely non-contacting. This can be said about the distance sensor, for example, when an eddy current sensor is used as a non-contact distance sensor as in the first embodiment, or as a non-contact distance sensor as described in the following embodiments, an ultrasonic wave is used. The same applies to sensors and laser sensors.

C: Third Embodiment A measuring apparatus according to a third embodiment of the present invention includes an ultrasonic sensor for measuring the operating state of the valve stem 6.

  Similar to the eddy current sensor 10, this ultrasonic sensor functions as a non-contact distance sensor, is configured to have an ultrasonic transmission / reception function, and is configured to transmit ultrasonic waves transmitted from the ultrasonic sensor. The operating state of the bar is measured based on the reciprocal propagation time between the ultrasonic sensor and the surface of the bar.

  And this ultrasonic sensor is opposed to the surface of the valve stem 6 in a non-contact manner, similar to the eddy current sensor 10 (see FIG. 2). As described above, when the ultrasonic sensor is disposed opposite to the surface of the valve stem 6 in a non-contact state, the valve stem 6 is moved by the movement of the valve stem 6 in the axial direction, the shape change or the vibration in the radial direction. When the distance between the surface 6 and the ultrasonic sensor changes, the ultrasonic propagation time between the ultrasonic sensor and the valve stem 6 changes corresponding to the change in the distance.

  And the change state of the reciprocating propagation time when the valve stem 6 is moving in the axial direction and the change state of the reciprocating propagation time when the valve stem 6 is stopped can be clearly distinguished. Therefore, it is possible to accurately determine the movement start / stop position of the valve stem 6 and the movement time / timing by both of them, and further, the amount of movement and the movement speed of the valve stem 6 in the axial direction. Can be obtained by calculation. In addition, it is possible to know whether or not the valve stem 6 is bent, tilted, or the like.

  In the third embodiment, as in the first embodiment, a plurality of the ultrasonic sensors are provided, and the valve rods are arranged by the circumferential arrangement, the axial arrangement, or the combined arrangement. Of course, it can arrange | position to 6 side.

D: Fourth Embodiment A measuring device according to a fourth embodiment of the present invention is provided with a laser sensor for measuring the operating state of the valve stem 6.

  Like the eddy current sensor 10, this laser sensor functions as a non-contact distance sensor, and reciprocates between the laser sensor emitted from the laser sensor and the surface of the rod. The operating state of the rod is measured based on time.

And this laser sensor is arranged to face the surface of the valve stem 6 in a non-contact manner, similar to the eddy current sensor 10 (see FIG. 2). As described above, when the laser sensor is disposed to face the surface of the valve stem 6 in a non-contact state, the valve stem 6 is moved by the movement of the valve stem 6 in the axial direction, the shape change, or the vibration in the radial direction. When the distance between the surface of the sensor and the ultrasonic sensor changes,
Corresponding to this change in distance, the round trip time of the laser light between the laser sensor and the surface of the valve stem 6 changes.

  The change state of the reciprocation time of the laser beam when the valve rod 6 is moving in the axial direction is clearly distinguished from the change state of the reciprocation time of the laser beam when the valve rod 6 is stopped. Therefore, it is possible to accurately determine the movement start / stop position of the valve stem 6 and the movement time / timing by using both of them. Quantity and moving speed can be obtained by calculation. In addition, it is possible to know whether or not the valve stem 6 is bent, tilted, or the like.

  In the fourth embodiment as well, as in the first embodiment, a plurality of the laser sensors are provided, and the valve rods 6 are arranged by the circumferential arrangement, the axial arrangement, or the combined arrangement. Of course, it can be arranged on the side.

E: Fifth Embodiment A measuring device according to a fifth embodiment of the present invention is provided with a magnetostrictive sensor for measuring the operating state of the valve stem 6, and the valve stem 6 has a magnitude of strain. This is a configuration suitable for a case where it is made of a material having a special magnetic characteristic in which the magnetic permeability changes correspondingly.

  That is, the magnetostrictive sensor functions as a non-contact distance sensor like the eddy current sensor 10, the capacitance sensor, the ultrasonic sensor, and the laser sensor, but unlike these sensors, The change state of the magnetic permeability due to strain is detected, and the operating state of the valve stem 6 is measured based on the change state of the magnetic permeability. The magnetostrictive sensor is arranged in a non-contact manner on the surface of the valve stem 6 as in the eddy current sensor 10 (see FIG. 2), but is not limited to this, and the surface of the valve stem 6 is not limited thereto. It can also be placed in contact with.

  As described above, when the magnetostrictive sensor is disposed so as to face the surface of the valve stem 6 in a non-contact state, an axial force acts on the valve stem 6 when the valve stem 6 is moved in the axial direction. Since the distortion occurs in the rod 6, the permeability in the strain direction changes and is detected by the magnetostrictive sensor. On the other hand, when the valve rod 6 is stopped, no axial force acts on the valve rod 6 and the distortion also occurs. The magnetic permeability does not change because it does not occur.

  Therefore, the movement start / stop position of the valve stem 6 and the movement time / time can be accurately determined based on the presence / absence and change state of the magnetic permeability. The movement amount and movement speed in the axial direction can be obtained by calculation. In addition, it is possible to know whether or not the valve stem 6 is bent, tilted, or the like.

  Further, since the change state of the magnetic permeability when the valve stem 6 is moving in the axial direction and the change state of the magnetic permeability when the valve stem 6 is stopped can be clearly distinguished. Both of them can accurately determine the movement start / stop position of the valve stem 6 and the movement time / timing, and then calculate the movement amount and movement speed of the valve stem 6 in the axial direction. Can be obtained.

In addition to using the magnetostrictive sensor as a non-contact distance sensor for measuring the operating state of the valve stem 6 as in this embodiment, the magnetostrictive sensor acts on the yoke based on, for example, a change in permeability due to the strain of the yoke. It can also be used as a yoke stress sensor that measures stress. Further, as in the first embodiment, it is possible to provide a plurality of the magnetostrictive sensors and arrange them on the valve stem 6 side by the circumferential arrangement, the axial arrangement, or the combined arrangement. is there.

  The present invention can be used for diagnosis of a valve device such as an electric valve installed in a nuclear power plant or the like.

1 .. Motorized valve 2 .. Motor 3 .. Yoke 4 .. Valve drive unit 6 .. Valve rod 7 .. Auxiliary material 10 .. Eddy current sensor 20 .. Capacitance sensor 21 .. Electrode unit 22 .. Main body 100 ..Air operated valve 101 ..Valve rod 102 ..Yoke 103 ..Eddy current sensor

Claims (8)

  An eddy current sensor equipped with a coil that generates a high-frequency magnetic field is disposed opposite to the surface of a conductive rod that moves in the axial direction in a non-contact state, and the distance between the rod and the eddy current sensor changes. Or a physical quantity corresponding to the impedance of the coil that changes in accordance with a change in the shape of the rod or the rod.   A non-contact distance sensor that is disposed in a non-contact state with respect to the surface of the rod body that moves in the axial direction and detects a change in the distance to the surface, and is based on a detection signal of the non-contact distance sensor A measuring device for measuring an operating state of a rod. In claim 2,
The non-contact distance sensor is composed of an eddy current sensor having a coil that generates a high-frequency magnetic field, and the impedance of the coil or the impedance that changes in accordance with a change in the distance to the rod or a change in the shape of the rod A measuring apparatus for measuring an operating state of the rod body based on a physical quantity corresponding to. In claim 2,
The non-contact distance sensor is composed of a capacitance sensor that detects a change in capacitance in an electric field, and a capacitance value that changes in accordance with a change in the distance to the rod or a change in shape of the rod A measuring apparatus for measuring the operating state of the rod body based on the above. In claim 2,
The non-contact distance sensor is composed of an ultrasonic sensor having an ultrasonic transmission / reception function, and a round-trip propagation time between the ultrasonic sensor transmitted from the ultrasonic sensor and the surface of the rod body A measuring apparatus for measuring the operating state of the rod body based on the above. In claim 2,
The non-contact distance sensor is composed of a laser sensor having a function of transmitting / receiving laser light, and is based on a round trip time between the laser sensor transmitted from the laser sensor and the surface of the rod body. A measuring apparatus for measuring an operating state of the rod. In claim 2, 3, 4, 5 or 6,
A plurality of the non-contact distance sensors are arranged in the circumferential direction of the rod body. In claim 2, 3, 4, 5 or 6,
A plurality of the non-contact distance sensors are arranged in the axial direction of the rod body.

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