JP2018155529A - Rotational angle detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotational angle detector which can be manufactured at lower cost, can have an increased detection accuracy by becoming less affected by use environments, and can be downsized by a simple configuration.SOLUTION: A rotational angle detector includes: a rotating sector gear 17 (base body); a vibration source 21 which is brought into contact with the sector gear 17 and vibrates the sector gear 17; and a vibration pick-up 22 brought into contact with a position spaced apart, in a direction of rotation, from a position of a surface of the sector gear where the vibration source 21 is brought into contact with the surface of the sector gear; and a signal processing circuit 32 for determining a rotational angle of the sector gear 17 on the basis of magnitude of vibration detected by the vibration pick-up 22. One of the vibration source 21 and the vibration pick-up 22 is fixed to the sector gear 17, and the other is supported by a print circuit board 26 (supporting member) while allowing for rotation of the sector gear 17.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rotation angle detection device that detects a rotation angle of a rotating member.

  2. Description of the Related Art Conventionally, for example, a rotary actuator that drives an air conditioning valve has a rotation angle detection device that detects a rotation angle of a rotation shaft. Many conventional rotation angle detection devices of this type use a potentiometer whose electric resistance changes according to the rotation angle, a magnetic sensor whose magnetic flux density changes according to the rotation angle, and the like.

In the air conditioning valve, the rotation angle detection device that detects the rotation angle of the rotation shaft greatly affects the control accuracy of the actuator. For this reason, in recent air conditioning valves, it is required to further increase the detection accuracy of the rotation angle detection device so that the opening degree can be controlled with higher accuracy.
In order to make detection accuracy higher than that of a rotation angle detection device using a potentiometer, a magnetic sensor, or the like, it is conceivable to use a measurement device as described in Patent Document 1, for example.
The measurement device disclosed in Patent Document 1 uses propagation of surface acoustic waves on a substrate for position detection.

JP 2011-257315 A

  However, the measuring device described in Patent Document 1 is greatly affected by heat and changes in accuracy. On the other hand, the temperature of the air conditioning valve changes greatly due to the heat of the drive motor and the heat of the control fluid flowing in the valve. For this reason, in order to apply the measuring device shown in Patent Document 1 to the rotary actuator of the air conditioning valve, the temperature characteristics cannot be maintained unless the base material of the measuring device is made of a material having a small coefficient of thermal expansion. Since such a base material is expensive, when this measuring device is used as an actuator for an air conditioning valve, the manufacturing cost of the air conditioning valve increases.

  Further, the surface acoustic wave sensor used in the measuring device of Patent Document 1 is also used for a humidity sensor, and is generally known to be greatly affected by humidity. For this reason, with this measuring device, it is difficult to accurately measure the opening of the air conditioning valve installed in a humidity environment where the relative humidity is 5 to 95 RH.

  Furthermore, in order to incorporate the measuring device disclosed in Patent Document 1 into an actuator for an air conditioning valve, the number of parts increases as described below, and the actuator becomes complicated due to structural and design restrictions. At the same time, there is a problem of increasing the size. There are two reasons why the number of parts increases. The first reason is that a base material for propagating surface acoustic waves is required separately from the actuator parts. The second reason is that a mechanism for interlocking the receiver and the actuator is necessary so that the receiver of the measuring device moves in the rotation direction of the actuator.

The structural restriction is that the propagation direction of the surface acoustic wave generated from the exciter must be configured to coincide with the rotation direction of the actuator, and the receiver must be arranged along this direction.
A design limitation is that the exciter and receiver must be installed on the same surface.
The present invention has been made to solve such a problem. The rotation is low in manufacturing cost, is hardly affected by the use environment, improves the detection accuracy, and can be downsized with a simple configuration. An object is to provide an angle detection device.

  In order to achieve this object, a rotation angle detection device according to the present invention comprises a rotating base for detecting a rotation angle, a vibration source that contacts the surface of the base and applies vibration to the base, and Based on the vibration pickup that detects the vibration of the base body in contact with the position separated from the position of the vibration source on the surface of the base body in the rotational direction of the base body, and the magnitude of the vibration detected by the vibration pickup A signal processing circuit for obtaining a rotation angle of the base, wherein one of the vibration source and the vibration pickup is fixed to the base and the other is supported differently from the base in a state in which the base is allowed to rotate. It is supported by the member.

  In the rotation angle detection device according to the aspect of the invention, the base is a gear constituting a part of a drive system of the rotary actuator, and the vibration source and the vibration pickup are in contact with an end face in the axial direction of the gear. You may do it.

  According to the present invention, in the rotation angle detection device, the base is a shaft that is rotated by being driven by a rotary actuator, and the vibration source and the vibration pickup may be in contact with an outer peripheral surface of the shaft. Good.

  In the rotation angle detection device according to the present invention, the shaft may be a valve stem of a valve in which a valve body rotates.

  In the rotation angle detection device according to the present invention, the support member may be a printed circuit board having a control circuit that controls the operation of the rotary actuator.

  According to the present invention, when the base vibrates together with the vibration source, the vibration wave is transmitted from the vibration source to the vibration pickup through the base. The vibration detected by the vibration pickup is attenuated according to the distance between the vibration source and the vibration pickup. This vibration is strong when the distance between the vibration source and the vibration pickup is short, and is weak when this distance is long. The distance between the vibration source and the vibration pickup corresponds to the magnitude of the rotation angle of the substrate. For this reason, according to this rotation angle detection device, the rotation angle of the substrate can be obtained based on the magnitude (strength) of this vibration.

  This rotation angle detection device is composed of a base, a vibration source, a vibration pickup, and a signal processing circuit, and has a simple structure realized with a small number of components. For this reason, according to this rotation angle detection apparatus, compared with the measuring apparatus shown in patent document 1, a manufacturing cost can be suppressed low. The vibration source and vibration pickup used in this rotational angle detection device are less susceptible to the effects of temperature and humidity compared to sensors using surface acoustic waves. it can. This also reduces the cost.

The magnitude (intensity) of the vibration transmitted from the vibration source to the vibration pickup does not change greatly even if the temperature or humidity changes. For this reason, it is difficult to be influenced by the use environment, and the detection accuracy is increased.
In addition, the position where the vibration source and the vibration pickup are in contact with the base does not need to consider the direction in which the vibration is propagated, and any position where the distance between these components changes as the base rotates. It may be in any position. For this reason, the degree of freedom is high in designing the rotation angle detection device. As a result, the vibration source and the vibration pickup can be arranged compactly with a simple mounting structure along the base.
Therefore, according to the present invention, it is possible to provide a rotation angle detection device that is high in detection accuracy while adopting a configuration that is low in manufacturing cost and hardly affected by the use environment, and that can be downsized with a simple configuration. it can.

It is a perspective view which fractures | ruptures and shows the valve body of the valve | bulb for air conditioning provided with the rotation angle detection apparatus by 1st Embodiment. It is a perspective view which shows the structure of the rotation angle detection apparatus by 1st Embodiment. It is a top view of a sector gear, a vibration source, and a vibration pickup in a fully closed state. It is a top view of a sector gear, a vibration source, and a vibration pickup in a fully open state. It is a block diagram which shows the structure of a control system. It is a graph which shows the change of the magnitude of vibration when changing from a fully closed state to a fully opened state. It is a graph which shows the change of the magnitude of vibration when changing from a full open state to a full closed state. It is a top view of a sector gear, a vibration source, and a vibration pickup showing a modification in which positions of the vibration source and the vibration pickup are different. It is a perspective view which shows the structure of the rotation angle detection apparatus by 2nd Embodiment.

(First embodiment)
Hereinafter, an embodiment of a rotation angle detection device according to the present invention will be described in detail with reference to FIGS.
A rotation angle detection device 1 shown in FIG. 1 is installed in an actuator 3 that drives an air conditioning valve 2. The air conditioning valve 2 is configured by assembling a valve body 5 and a valve stem 6 to a valve body 4. A fluid passage 7 is formed inside the valve body 4. Mounting flanges 8 are provided at both ends of the valve body 4.

The valve body 5 is formed in a spherical shape and is disposed in the fluid passage 7 and is rotatably supported by the valve body 4.
The valve stem 6 is formed in a columnar shape, and is rotatably supported by the valve body 4 with one end projecting from the valve body 4. One end of the valve stem 6 is connected to the actuator 3. The other end of the valve stem 6 is connected to the valve body 5 so as to rotate integrally. For this reason, the valve body 5 rotates around the axis C <b> 1 of the valve stem 6. The maximum rotation angle when the valve body 5 rotates is about 90 °. In the air conditioning valve 2 according to this embodiment, when the valve body 5 is rotated about 90 ° from the fully open state, the valve body 5 is fully closed, and the valve body 5 is rotated about 90 ° in the opposite direction from the fully closed state. To return to the fully open state.

The actuator 3 includes a housing 11 supported by the valve body 4, a driving motor 12 and a valve control device 13 accommodated in the housing 11.
The drive motor 12 serves as a power source for driving the air conditioning valve 2, and is connected to the valve stem 6 via the transmission mechanism 14. The transmission mechanism 14 constitutes a drive system for the rotary actuator 3, and includes a rotary shaft 16 connected to the valve stem 6 via a joint 15, a sector gear 17 fixed to the rotary shaft 16, A gear group (not shown) for connecting the sector gear 17 and the pinion 18 of the drive motor 12 is included.

  As shown in FIG. 2, the sector gear 17 includes a boss portion 17a through which the rotary shaft 16 passes, and a plate-like main body portion 17b that protrudes radially outward from the boss portion 17a. The main body portion 17 b is formed in a fan shape when viewed from the axial direction of the rotating shaft 16. Teeth 17c are formed on the peripheral wall portion of the main body portion 17b.

  The gear group of the transmission mechanism 14 includes a plurality of gears that mesh with each other. In FIG. 1, the gear group is omitted for easy understanding of the configuration. The sector gear 17 and pinion 18 of the transmission mechanism 14 and the gears of the gear group are made of a plastic material. In this transmission mechanism 14, the sector gear 17 moves from the fully closed position shown in FIG. 3 by shifting from the fully closed state where the opening degree of the air conditioning valve 2 is 0% to the fully open state where the opening degree is 100%. In FIG. 4, it is turned about 90 ° counterclockwise, and is located at the fully open position shown in FIG. In this embodiment, the sector gear 17 corresponds to the “base” in the invention described in claim 1 and corresponds to the “gear” in the invention described in claim 2.

  The valve control device 13 controls the operation of the drive motor 12 so that the current opening degree of the air conditioning valve 2 becomes the target opening degree. As shown in FIG. 5, the valve control device 13 is connected to the drive motor 12, the vibration source 21, and the vibration pickup 22, and has a plurality of functional units. Although the details will be described later, the plurality of functional units are a communication unit 23, a motor control unit 24, and an opening degree detection unit 25.

The current opening degree of the air conditioning valve 2 is detected by a rotation angle detection device 1 having a vibration source 21 and a vibration pickup 22. The description of the rotation angle detection device 1 will be described later.
The target opening degree of the air conditioning valve 2 is set by an air conditioning control device (not shown), and is sent as a control signal from the air conditioning control device to the valve control device 13.

  The vibration source 21 connected to the valve control device 13 vibrates when energized. Although not shown in detail as the vibration source 21, for example, a vibration motor or a piezoelectric element can be used. As shown in FIG. 2, the vibration source 21 is mounted on the printed circuit board 26 and supported by the printed circuit board 26, and in the vicinity of the sector gear 17 together with the printed circuit board 26 while allowing the sector gear 17 to rotate. Has been placed. In this embodiment, the printed circuit board 26 corresponds to a “support member” in the present invention.

  The printed circuit board 26 according to this embodiment is supported by the casing 11 of the actuator 3 via a pressing mechanism (not shown) in a state where the mounting surface having the vibration source 21 faces one end surface of the sector gear 17 in the axial direction. ing. The pressing mechanism is configured to bias the printed circuit board 26 toward the sector gear 17. In the following, one end surface in the axial direction of the sector gear 17 facing the printed circuit board 26 is simply referred to as a detection surface 27.

  The vibration source 21 contacts the detection surface 27 of the sector gear 17 when the printed circuit board 26 is urged by the pressing mechanism. When the vibration source 21 is energized and vibrates in this contact state, this vibration is transmitted to the sector gear 17. As shown in FIG. 3, the vibration source 21 according to this embodiment is in contact with one end of the sector gear 17 in the rotational direction in the fully closed position. This one end portion is one end portion of the sector gear 17 that is on the front side in the traveling direction when the sector gear 17 rotates in the direction in which the opening of the air conditioning valve 2 increases (counterclockwise in FIG. 3).

  For this reason, the sector gear 17 rotates between the fully closed position shown in FIG. 3 and the fully opened position shown in FIG. 4 in a state where the vibration source 21 is in contact with the detection surface 27. As shown by a two-dot chain line in FIG. 2, a sheet 28 made of a material having a low frictional resistance can be sandwiched between the sector gear 17 and the vibration source 21. An example of the sheet 28 is a Teflon (registered trademark) sheet. The sheet 28 shown in FIG. 2 is formed in a shape that covers the entire range in which the vibration source 21 is in sliding contact, and is attached to the detection surface 27. Note that this type of seat can be provided in the vibration source 21 instead of being provided in the sector gear 17.

  As the vibration pickup 22 connected to the valve control device 13, for example, an acceleration sensor (not shown) that converts vibration into an electrical signal can be used. The vibration pickup 22 is fixed with a fixing screw or an adhesive (not shown) in contact with the detection surface 27 of the sector gear 17. For this reason, the vibration pickup 22 detects the vibration of the detection surface 27 of the sector gear 17.

  As shown in FIG. 3, the position where the vibration pickup 22 is fixed on the detection surface 27 is a position away from the position where the vibration source 21 contacts in the rotational direction of the sector gear 17. A distance R1 between the vibration pickup 22 and the rotation center of the sector gear 17 is equal to a distance R2 between the vibration source 21 and the rotation center of the sector gear 17. The vibration pickup 22 according to this embodiment is one end portion in the rotation direction of the sector gear 17 in the fully closed position, and the rear side in the traveling direction when the sector gear 17 rotates in the direction in which the opening degree of the air conditioning valve 2 increases. Is disposed at one end of the sector gear 17. For this reason, the distance between the vibration pickup 22 and the vibration source 21 is gradually shortened as the sector gear 17 rotates from the fully closed position shown in FIG. 3 to the fully open position shown in FIG. 4, and the sector gear 17 is fully opened. It gradually becomes longer by turning to the fully closed position.

The communication unit 23 provided in the valve control device 13 has a function of receiving a control signal from an air conditioning control device (not shown). This control signal includes target opening data.
The motor control unit 24 has a function of switching the normal rotation and reverse rotation of the drive motor 12 and controlling the operation of the rotary actuator 3 by switching the rotation and stop of the drive motor 12. The motor control unit 24 according to this embodiment is provided as a control circuit 31 on the printed circuit board 26 described above.

The opening degree detection unit 25 constitutes a part of the rotation angle detection device 1 and is provided as a signal processing circuit 32 on the printed circuit board 26. The rotation angle detection device 1 according to this embodiment includes the signal processing circuit 32, the vibration source 21, the vibration pickup 22, the sector gear 17, and the like.
The opening degree detection unit 25 has first to third functions. The first function is a function for obtaining the current opening degree of the air conditioning valve 2 based on the magnitude of vibration detected by the vibration pickup 22 described above.

  The vibration pickup 22 detects a vibration wave transmitted from the vibration source 21 via the sector gear 17. The vibration detected by the vibration pickup 22 is attenuated according to the distance between the vibration source 21 and the vibration pickup 22. This vibration is strong when the distance between the vibration source 21 and the vibration pickup 22 is short, and is weak when this distance is long. For this reason, the magnitude of the vibration detected by the vibration pickup 22 corresponds to the magnitude of the rotation angle of the sector gear 17.

  In this embodiment, the vibration detected by the vibration pickup 22 is the smallest (weak) when the sector gear 17 is in the fully closed position shown in FIG. 3, and the largest when the sector gear 17 is in the fully opened position shown in FIG. Become stronger. The vibration detected by the vibration pickup 22 when the sector gear 17 rotates from about 0 ° in the fully closed position to about 90 ° in the fully open position gradually increases as shown in FIG. The vibration detected by the vibration pickup 22 when the sector gear 17 rotates from the fully open position to the fully closed position gradually decreases as shown in FIG.

  When the opening degree detection unit 25 obtains the current opening degree, for example, the opening degree corresponding to the current magnitude of vibration detected by the vibration pickup 22 is read from a data map (not shown) for opening degree determination. Can be done. In this data map, data obtained by experiments conducted using the vibration pickup 22 is recorded. This data is the magnitude of the vibration during the experiment and the opening when the vibration is detected. For this reason, the current opening degree calculated | required by the opening degree detection part 25 is an opening degree at the time of an experiment corresponding to the magnitude | size of the present vibration.

  The second function of the opening degree detection unit 25 is a function of removing unnecessary vibrations from vibrations detected by the vibration pickup 22. Unnecessary vibration is vibration generated by the rotation of the drive motor 12 or vibration transmitted from the valve body 4. This second function can be realized by performing correction processing such as noise cut and averaging processing on the output data of the vibration pickup 22.

  The third function of the opening detection unit 25 is a function of detecting an abnormality in the drive motor 12 and the transmission mechanism 14. When an abnormality occurs in the drive motor 12 or the transmission mechanism 14, it appears as vibration. By detecting vibration caused by such an abnormality, it is possible to determine the presence or absence of the abnormality. The opening degree detection unit 25 analyzes the frequency component of the vibration included in the detection data of the vibration pickup 22, and determines that there is an abnormality when detecting the vibration of the frequency component corresponding to the abnormal vibration.

In the air conditioning valve 2 configured as described above, the operation of the drive motor 12 is controlled by the valve control device 13 so that the current opening obtained by the rotation angle detection device 1 matches the target opening. The
The rotation angle detection device 1 according to this embodiment includes a sector gear 17, a vibration source 21, a vibration pickup 22, and a signal processing circuit 32, and has a simple structure realized with a small number of components. It is. For this reason, according to this rotation angle detection apparatus 1, compared with the measuring apparatus shown in patent document 1, a manufacturing cost can be suppressed low.
The vibration source 21 and the vibration pickup 22 used in the rotation angle detection device 1 are less susceptible to the influence of temperature and humidity than a sensor using surface acoustic waves, and both are inexpensive products that are commercially available. Can be used. This also reduces the cost.

The magnitude (intensity) of vibration propagated from the vibration source 21 to the vibration pickup 22 does not change greatly even if the temperature and humidity change. For this reason, it is difficult to be influenced by the use environment, and the detection accuracy is increased.
Further, the position at which the vibration source 21 and the vibration pickup 22 are in contact with the sector gear 17 does not need to consider the direction in which the vibration is propagated, and the distance between these components changes as the sector gear 17 rotates. Any position is acceptable. For this reason, the degree of freedom is high in designing the rotation angle detection device 1. As a result, the vibration source 21 and the vibration pickup 22 can be arranged compactly with a simple mounting structure along the sector gear 17.
Therefore, according to this embodiment, it is possible to provide a rotation angle detection device that is low in manufacturing cost, hardly affected by the use environment, improves detection accuracy, and can be downsized with a simple configuration. Can do.

The sector gear 17 according to this embodiment constitutes a part of the drive system of the rotary actuator 3. The vibration source 21 and the vibration pickup 22 are in contact with the end surface (detection surface 27) of the sector gear 17 in the axial direction.
According to this embodiment, a component that exclusively functions as a vibration transmitting base is not required. For this reason, compared with the case where the exclusive component which functions as a base for vibration transmission is used, the number of components is reduced, the manufacturing cost is further reduced, and further miniaturization becomes possible.

The vibration source 21 according to this embodiment is supported by a printed circuit board 26 having a control circuit 31 that controls the operation of the rotary actuator 3.
According to this embodiment, a component that exclusively supports the vibration source 21 is unnecessary. For this reason, compared with the case where the exclusive component which functions as a supporting member is used, the number of components is reduced, the manufacturing cost is further reduced, and further downsizing is possible.

The rotation angle detection device 1 according to this embodiment uses the current opening degree as the opening degree during the experiment corresponding to the current magnitude of vibration. For this reason, when installing the vibration source 21 and the vibration pickup 22, it is not necessary to perform precise positioning.
The vibration pickup 22 can detect not only vibrations transmitted through the surface but also vibration waves transmitted through the substance. For this reason, the position where the vibration source 21 and the vibration pickup 22 are in contact with the sector gear 17 is not limited to the position shown in FIG. 3 and can be changed as appropriate. For example, the vibration source 21 and the vibration pickup 22 may be disposed separately on the upper surface side and the lower surface side of the sector gear 17 or may be disposed in contact with the peripheral surface 17d of the sector gear 17 as shown in FIG. it can.

(Second Embodiment)
The substrate to be detected by the rotation angle detection device according to the present invention can be a shaft as shown in FIG. In FIG. 9, the same or equivalent members as those described with reference to FIGS.
The rotation angle detection device 41 shown in FIG. 9 uses a shaft 42 as a base.
A shaft 42 shown in FIG. 9 is a shaft that is driven by the rotary actuator 3 to rotate. Such a shaft 42 corresponds to the rotating shaft 16 of the rotary actuator 3, the valve stem 6 of the air conditioning valve 2, or the like.

The shaft 42 is formed in a cylindrical shape from a metal material, and rotates about an axis C2 parallel to the longitudinal direction by the power of the drive motor 12 (not shown).
The vibration source 21 is in contact with the outer peripheral surface 42a of the shaft 42 in a state where the vibration source 21 is supported by a printed circuit board 26 or other support member (not shown).

The vibration pickup 22 is fixed by a fixing screw or an adhesive (not shown) in contact with the outer peripheral surface 42a of the shaft 42. The position where the vibration pickup 22 is fixed on the outer peripheral surface 42 a is a position separated from the vibration source 21 by a predetermined distance in the circumferential direction of the shaft 42. The vibration pickup 22 according to this embodiment is provided at a position away from the vibration source 21 in the axial direction of the shaft 42.
As shown in this embodiment, even if the rotation angle detection device is configured using the shaft 42 as a base body, the same effect as in the case of adopting the first embodiment can be obtained.

Also in this embodiment, there is no need for a component that functions exclusively as a vibration transmitting base. For this reason, compared with the case where the exclusive component which functions as a base | substrate is used, the number of components decreases, manufacturing cost becomes still lower, and further size reduction is attained.
In this embodiment, when the shaft 42 is the valve stem 6 of the air conditioning valve 2, the rotation angle of the valve stem 6 can be directly detected. Therefore, by adopting this configuration, it is possible to provide a rotation angle detection device with even higher detection accuracy.

  In each of the above-described embodiments, the vibration source 21 slidably contacts the sector gear 17 and the shaft 42, and the vibration pickup 22 is fixed to the sector gear 17 and the shaft 42. However, the present invention is not limited to such a limitation, and the vibration source 21 is fixed to the sector gear 17 and the shaft 42, and the vibration pickup 22 is slidably in contact with the sector gear 17 and the shaft 42. be able to.

  In the above-described first embodiment, an example in which the sector gear 17 that transmits vibration is formed of a plastic material has been described. However, the sector gear 17 can be formed of a metal material. In the second embodiment, an example in which the shaft 42 is formed of a metal material has been described. However, the shaft 42 can be formed of a plastic material.

  DESCRIPTION OF SYMBOLS 1 ... Rotation angle detection apparatus, 2 ... Air conditioning valve, 3 ... Rotary actuator, 6 ... Valve stem, 14 ... Transmission mechanism (drive system), 16 ... Rotating shaft, 17 ... Sector gear (base | substrate), 21 ... Vibration Source 22 ... Vibration pickup 26 ... Printed circuit board (support member) 27 ... Detection surface 31 ... Control circuit 32 ... Signal processing circuit 42 ... Shaft 42a ... Outer peripheral surface

Claims (5)

A rotating base for detecting a rotation angle;
A vibration source that contacts the surface of the substrate and applies vibrations to the substrate;
A vibration pickup that detects a vibration of the base body in contact with a position spaced in the rotation direction of the base body from a position where the vibration source contacts on the surface of the base body;
A signal processing circuit for obtaining a rotation angle of the base based on the magnitude of vibration detected by the vibration pickup;
One of the vibration source and the vibration pickup is fixed to the base, and the other is supported on a rotation member that is supported by a support member different from the base while allowing the base to rotate. The rotation angle detection device according to claim 1,
The base is a gear constituting a part of a drive system of the rotary actuator,
The rotation angle detection device, wherein the vibration source and the vibration pickup are in contact with an end face of the gear in the axial direction. The rotation angle detection device according to claim 1,
The base is a shaft that rotates by being driven by a rotary actuator,
The rotation angle detecting device, wherein the vibration source and the vibration pickup are in contact with an outer peripheral surface of the shaft. In the rotation angle detection device according to claim 3,
The rotation angle detecting device according to claim 1, wherein the shaft is a valve stem of a valve in which a valve body rotates. In the rotation angle detection device according to any one of claims 2 to 4,
The rotation angle detection device according to claim 1, wherein the support member is a printed circuit board having a control circuit for controlling the operation of the rotary actuator.

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