Operation detection device for actuator

Abstract

To reduce the number of wires and enable miniaturization.SOLUTION: When a solenoid valve 11 is switched to a holding state, if at least one of fluid output from a first output port A to a first pressure application chamber 44 and fluid output from a second output port B to a second pressure application chamber 45 leaks, a pressure detected by a pressure sensor 61 drops. In this way, a microcomputer 62 determines that fluid leak has occurred when the pressure detected by the pressure sensor 61 drops. Therefore, an operation detection device 60 of an actuator 40 does not need to comprise a pressure sensor that detects the pressure of the fluid output to the first pressure application chamber 44 and a pressure sensor that detects the pressure of the fluid output to the second pressure application chamber 45.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an actuator operation detection device.

Background Art

[0002] An actuator has a piston rod reciprocating by fluids output from a first output port of a solenoid valve having a first output port and a second output port to a first pressure acting chamber and fluids output from the second output port to a second pressure acting chamber. In such an actuator, the piston rod is held when the solenoid valve switches to a holding state capable of holding the pressure of the fluid output from the first output port to the first pressure acting chamber and the pressure of the fluid output from the second output port to the second pressure acting chamber, respectively. An operation detection device for detecting the operation of such an actuator is disclosed in, for example, Patent Document 1. The actuator operation detection device includes a pressure sensor for detecting the pressure of the fluid output to the first pressure acting chamber and a pressure sensor for detecting the pressure of the fluid output to the second pressure acting chamber, respectively.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in such an actuator operation detection device, since two pressure sensors are required, the operation detection device itself becomes large-sized. In addition, since wiring extends from each pressure sensor, the number of wirings increases. Therefore, an operation detection device capable of reducing the number of wirings and achieving miniaturization is desired.

Means for Solving the Problems

[0005] Each aspect for solving the above problems will be described. [Aspect 1] An actuator operation detection device for holding a piston rod, wherein the piston rod reciprocates by fluids output from a first output port of a solenoid valve having a first output port and a second output port to a first pressure acting chamber and from the second output port to a second pressure acting chamber, and the solenoid valve switches to a holding state capable of holding the pressure of the fluid output from the first output port to the first pressure acting chamber and the pressure of the fluid output from the second output port to the second pressure acting chamber respectively, comprising: A pressure sensor for detecting one of the pressure of the fluid output to the first pressure acting chamber and the pressure of the fluid output to the second pressure acting chamber; A determination unit for determining whether or not fluid leakage has occurred based on the pressure detected by the pressure sensor when the solenoid valve is switched to the holding state. The actuator operation detection device is characterized by comprising the above.

[0006] [Aspect 2] The actuator operation detection device according to [Aspect 1], wherein the determination unit converts the pressure drop amount detected by the pressure sensor into a pressure drop rate, and determines that fluid leakage has occurred when the drop rate is equal to or greater than a certain value.

[0007] [Aspect 3] A spacer is provided between a manifold base having a first output flow path communicating with the first output port and outputting fluid to the first pressure acting chamber, and a second output flow path communicating with the second output port and outputting fluid to the second pressure acting chamber, and the solenoid valve, The spacer has: A first output connection flow path connecting the first output port and the first output flow path; A second output connection flow path connecting the second output port and the second output flow path. The pressure sensor is characterized by detecting one of the pressure of the fluid flowing through the first output connection flow path and the pressure of the fluid flowing through the second output connection flow path, and is the actuator operation detection device according to [Aspect 1] or [Aspect 2].

[0008] [Aspect 4] The spacer has a branch flow path that branches from one of the first output connection flow path and the second output connection flow path. The pressure sensor is characterized by detecting the pressure of the fluid flowing from one of the first output connection flow path and the second output connection flow path into the branch flow path, and is the actuator operation detection device according to [Aspect 3]. [Advantages of the Invention]

[0009] According to this invention, the number of wirings can be reduced and miniaturization can be achieved. [Brief Description of the Drawings]

[0010]

Figure 1

Figure 2

Figure 3

[0011] Hereinafter, an embodiment in which an actuator operation detection device is embodied will be described with reference to FIGS. 1 to 3. The actuator operation detection device of this embodiment constitutes a part of an electromagnetic valve manifold.

[0012] [Overall Configuration of the Electromagnetic Valve Manifold] As shown in FIG. 1, the solenoid valve manifold 10 includes a solenoid valve 11, a manifold base 31, and a spacer 51. The spacer 51 is interposed between the manifold base 31 and the solenoid valve 11. The solenoid valve 11 is mounted on the mounting surface 31a of the manifold base 31 via the spacer 51. Therefore, the manifold base 31 mounts the solenoid valve 11.

[0013] <Solenoid valve> The solenoid valve 11 has a valve casing 12. The valve casing 12 is in the shape of a long rectangular block. The valve casing 12 has a casing body 13, a first connecting block 14, and a second connecting block 15. The casing body 13 is in the shape of a long rectangular block. The first connecting block 14 is connected to the first end in the longitudinal direction of the casing body 13. The second connecting block 15 is connected to the second end in the longitudinal direction of the casing body 13. The casing body 13 has a main body facing surface 13a facing the spacer 51.

[0014] The valve casing 12 has a valve hole 16. The valve hole 16 is formed in the casing body 13. The valve hole 16 is circular. The valve hole 16 extends in the longitudinal direction of the casing body 13. The first end of the valve hole 16 opens to the first end face in the longitudinal direction of the casing body 13. The second end of the valve hole 16 opens to the second end face in the longitudinal direction of the casing body 13. Therefore, the valve hole 16 penetrates the casing body 13 in the longitudinal direction.

[0015] The solenoid valve 11 has a spool valve 17. The spool valve 17 is inserted into the valve hole 16. The spool valve 17 is inserted into the valve hole 16 with the axial direction of the spool valve 17 coinciding with the axial direction of the valve hole 16. The spool valve 17 is inserted into the valve hole 16 so as to be reciprocally movable.

[0016] The solenoid valve 11 has a supply port P, a first output port A, a second output port B, a first discharge port R1, and a second discharge port R2. Therefore, the solenoid valve 11 of the present embodiment is a 5-port solenoid valve. The supply port P, the first output port A, the second output port B, the first discharge port R1, and the second discharge port R2 are formed in the casing body 13. The supply port P, the first output port A, the second output port B, the first discharge port R1, and the second discharge port R2 communicate with the valve holes 16 respectively.

[0017] The first discharge port R1, the first output port A, the supply port P, the second output port B, and the second discharge port R2 are arranged in this order along the longitudinal direction of the casing body 13 from the first end to the second end of the casing body 13 and are formed in the casing body 13. The first ends of the supply port P, the first output port A, the second output port B, the first discharge port R1, and the second discharge port R2 communicate with the valve holes 16 respectively. The second ends of the supply port P, the first output port A, the second output port B, the first discharge port R1, and the second discharge port R2 open to the main body facing surface 13a of the casing body 13.

[0018] The solenoid valve 11 has a first piston 18 and a second piston 19. The first piston 18 is disc-shaped. The first piston 18 is connected to the first end of the spool valve 17. The first piston 18 moves integrally with the spool valve 17. The second piston 19 is disc-shaped. The second piston 19 is connected to the second end of the spool valve 17. The second piston 19 moves integrally with the spool valve 17.

[0019] A circular hole-shaped first piston housing recess 20 is formed in the first connection block 14. The first piston 18 is reciprocally housed in the first piston housing recess 20. Then, the first pilot pressure acting chamber 21 is partitioned by the first piston housing recess 20 and the first piston 18. Pilot fluid is supplied and discharged to and from the first pilot pressure acting chamber 21.

[0020] The second connecting block 15 is formed with a second piston accommodating recess 22 in the shape of a circular hole. A second piston 19 is reciprocally accommodated in the second piston accommodating recess 22. The second piston accommodating recess 22 and the second piston 19 define a second pilot pressure acting chamber 23. Pilot fluid is supplied to and discharged from the second pilot pressure acting chamber 23.

[0021] The second connecting block 15 is formed with a spring accommodating chamber 24. The spring accommodating chamber 24 opens to the end face on the side of the casing body 13 in the second connecting block 15. The spring accommodating chamber 24 communicates with the valve hole 16. The second connecting block 15 is formed with a communication hole 25. The communication hole 25 communicates the spring accommodating chamber 24 with the inside of the second piston accommodating recess 22. The first piston accommodating recess 20, the valve hole 16, the spring accommodating chamber 24, the communication hole 25, and the second piston accommodating recess 22 are formed in the valve casing 12 in this order side by side from the first end to the second end of the valve casing 12. The spool valve 17 extends from the inside of the first piston accommodating recess 20 through the valve hole 16, the spring accommodating chamber 24, and the communication hole 25 to the inside of the second piston accommodating recess 22.

[0022] The solenoid valve 11 has a return spring 26, a first spring receiving portion 27, and a second spring receiving portion 28. The return spring 26, the first spring receiving portion 27, and the second spring receiving portion 28 are accommodated in the spring accommodating chamber 24.

[0023] The first spring receiving portion 27 is annular. The spool valve 17 passes through the inside of the first spring receiving portion 27. The spool valve 17 has a first abutting portion 29 against which the first spring receiving portion 27 abuts. The first abutting portion 29 is, for example, a step formed on the outer peripheral surface of the spool valve 17. Further, the first spring receiving portion 27 can abut around the valve hole 16 on the end face of the casing body 13 on the side of the second connecting block 15.

[0024] The second spring receiving portion 28 is annular. The spool valve 17 passes through the inside of the second spring receiving portion 28. The second spring receiving portion 28 faces the first spring receiving portion 27 in the axial direction of the spool valve 17. The spool valve 17 has a second abutting portion 30 against which the second spring receiving portion 28 abuts. The second abutting portion 30 is, for example, an annular flange extending from the outer peripheral surface of the spool valve 17. Further, the second spring receiving portion 28 can abut around the communication hole 25 in the second connecting block 15.

[0025] The return spring 26 is interposed between the first spring receiving portion 27 and the second spring receiving portion 28. The first end of the return spring 26 is supported by the first spring receiving portion 27. The second end of the return spring 26 is supported by the second spring receiving portion 28.

[0026] The solenoid valve 11 includes a first pilot valve V1 and a second pilot valve V2. Therefore, the solenoid valve 11 is a double-solenoid type pilot-operated solenoid valve. Application of voltage to the first pilot valve V1 and the second pilot valve V2 is performed by an external control device such as a programmable logic controller (PLC) not shown in the figure.

[0027] <Manifold base> The manifold base 31 has a supply passage 32, a first output passage 33, a second output passage 34, a first discharge passage 35, and a second discharge passage 36. The supply passage 32, the first output passage 33, the second output passage 34, the first discharge passage 35, and the second discharge passage 36 open to the mounting surface 31a.

[0028] The end of the supply channel 32 on the side opposite to the mounting surface 31a is connected to a fluid supply source (not shown) via, for example, a pipe or the like. The fluid supplied from the fluid supply source to the supply channel 32 is compressed air. The end of the first output channel 33 on the side opposite to the mounting surface 31a is connected to the actuator 40 via the first pipe 37. The end of the second output channel 34 on the side opposite to the mounting surface 31a is connected to the actuator 40 via the second pipe 38. The ends of the first discharge channel 35 and the second discharge channel 36 on the side opposite to the mounting surface 31a communicate with the atmosphere respectively.

[0029] <actuator> The actuator 40 includes a cylinder tube 41. A piston 42 is reciprocally accommodated in the cylinder tube 41. A piston rod 43 is integrally provided on the piston 42. The piston rod 43 can project in and out of the cylinder tube 41. The inside of the cylinder tube 41 is partitioned by the piston 42 into a first pressure acting chamber 44 and a second pressure acting chamber 45. The piston rod 43 is integrally provided on the piston 42. The first output channel 33 communicates with the first pressure acting chamber 44 via the first pipe 37. The first output channel 33 outputs fluid to the first pressure acting chamber 44 via the first pipe 37. The second output channel 34 communicates with the second pressure acting chamber 45 via the second pipe 38. The second output channel 34 outputs fluid to the second pressure acting chamber 45 via the second pipe 38.

[0030] <spacer> The spacer 51 is in the shape of a long rectangular block. The spacer 51 has a first opposing surface 51a facing the valve casing 12 and a second opposing surface 51b facing the manifold base 31. The longitudinal direction of the spacer 51 coincides with the longitudinal direction of the valve casing 12. The spacer 51 has a supply connection channel 52, a first output connection channel 53, a second output connection channel 54, a first discharge connection channel 55, and a second discharge connection channel 56.

[0031] The supply connection passage 52 connects the supply port P and the supply passage 32. The first output connection passage 53 connects the first output port A and the first output passage 33. Accordingly, the first output passage 33 communicates with the first output port A via the first output connection passage 53. The second output connection passage 54 connects the second output port B and the second output passage 34. Accordingly, the second output passage 34 communicates with the second output port B via the second output connection passage 54. The first discharge connection passage 55 connects the first discharge port R1 and the first discharge passage 35. The second discharge connection passage 56 connects the second discharge port R2 and the second discharge passage 36.

[0032] <Actuator Operation> As shown in FIGS. 1, 2, and 3, the spool valve 17 is switchable between a first position, a second position, and an intermediate position. For example, it is assumed that a voltage is applied to the first pilot valve V1 and the application of voltage to the second pilot valve V2 is stopped. Then, the compressed fluid from the fluid supply source is supplied as pilot fluid to the first pilot pressure working chamber 21 by the first pilot valve V1. On the other hand, the pilot fluid in the second pilot pressure working chamber 23 is discharged to the atmosphere by the second pilot valve V2. As a result, as shown in FIG. 2, the pilot pressure in the first pilot pressure working chamber 21 overcomes the spring force of the return spring 26, and the spool valve 17 moves toward the second piston housing recess 22. As a result, the spool valve 17 switches to the first position where the supply port P and the first output port A communicate with each other, and the second output port B and the second discharge port R2 communicate with each other. Further, when the spool valve 17 switches to the first position, the connection between the supply port P and the second output port B is blocked, and the connection between the first output port A and the first discharge port R1 is blocked.

[0033] When the spool valve 17 switches to the first position, the fluid from the fluid supply source is supplied to the first pressure acting chamber 44 through the supply flow path 32, the supply connection flow path 52, the supply port P, the first output port A, the first output connection flow path 53, the first output flow path 33, and the first pipe 37. Also, the fluid in the second pressure acting chamber 45 is discharged to the outside through the second pipe 38, the second output flow path 34, the second output connection flow path 54, the second output port B, the second discharge port R2, the second discharge connection flow path 56, and the second discharge flow path 36. As a result, the piston 42 in the cylinder tube 41 moves to one stroke end in the axial direction of the cylinder tube 41. Consequently, the piston rod 43 of the actuator 40 protrudes from the cylinder tube 41.

[0034] For example, assume that the application of voltage to the first pilot valve V1 is stopped and the application of voltage to the second pilot valve V2 is being performed. Then, the compressed fluid from the fluid supply source is supplied as pilot fluid to the second pilot pressure acting chamber 23 by the second pilot valve V2. On the other hand, the pilot fluid in the first pilot pressure acting chamber 21 is discharged to the atmosphere by the first pilot valve V1. As a result, as shown in FIG. 3, the pilot pressure in the second pilot pressure acting chamber 23 overcomes the spring force of the return spring 26, and the spool valve 17 moves toward the first piston housing recess 20. Consequently, the spool valve 17 switches to the second position where the supply port P communicates with the second output port B and the first output port A communicates with the first discharge port R1. Also, when the spool valve 17 switches to the second position, the connection between the supply port P and the first output port A is blocked, and the connection between the second output port B and the second discharge port R2 is blocked.

[0035] When the spool valve 17 switches to the second position, the fluid from the fluid supply source is supplied to the second pressure acting chamber 45 via the supply flow path 32, the supply connection flow path 52, the supply port P, the second output port B, the second output connection flow path 54, the second output flow path 34, and the second pipe 38. Also, the fluid in the first pressure acting chamber 44 is discharged to the outside via the first pipe 37, the first output flow path 33, the first output connection flow path 53, the first output port A, the first discharge port R1, the first discharge connection flow path 55, and the first discharge flow path 35. As a result, the piston 42 in the cylinder tube 41 moves to the other stroke end in the axial direction of the cylinder tube 41. Consequently, the piston rod 43 of the actuator 40 is in a state of being immersed from the cylinder tube 41.

[0036] In this way, in the actuator 40, the piston rod 43 reciprocates by the fluid output from the first output port A to the first pressure acting chamber 44 and the fluid output from the second output port B to the second pressure acting chamber 45.

[0037] When the application of voltage to both the first pilot valve V1 and the second pilot valve V2 is stopped, the pilot fluid in the first pilot pressure acting chamber 21 is discharged to the atmosphere, and the pilot fluid in the second pilot pressure acting chamber 23 is discharged to the atmosphere. Then, as shown in FIG. 1, the spool valve 17 returns to the neutral position by the restoring force of the return spring 26. As a result, the communication of each of the supply port P, the first output port A, the second output port B, the first discharge port R1, and the second discharge port R2 is blocked. And the space between the first pressure acting chamber 44 and the first output port A and the space between the second pressure acting chamber 45 and the second output port B are filled with fluid. As a result, the reciprocating motion of the piston rod 43 of the actuator 40 suddenly stops at the intermediate position of the stroke. Therefore, the return spring 26 is set with a spring force so as to hold the spool valve 17 in the neutral position.

[0038] In this way, the piston rod 43 is held by switching the electromagnetic valve 11 to a holding state capable of holding the pressure of the fluid output from the first output port A to the first pressure acting chamber 44 and the pressure of the fluid output from the second output port B to the second pressure acting chamber 45, respectively. The electromagnetic valve 11 of the present embodiment is a three-position switching valve that can be switched to three positions: a first position, a second position, and an intermediate position.

[0039] <Actuator operation detection device> The operation detection device 60 includes a pressure sensor 61 and a microcomputer 62. In the present embodiment, the spacer 51 constitutes a part of the operation detection device 60. Therefore, the operation detection device 60 includes the spacer 51.

[0040] The pressure sensor 61 is mounted on the circuit board 63. The microcomputer 62 is mounted on the control board 64. The circuit board 63 and the control board 64 are electrically connected by a wiring 65.

[0041] The spacer 51 has a branch flow path 66. The first end of the branch flow path 66 communicates with the first output connection flow path 53. The branch flow path 66 branches from the first output connection flow path 53. The spacer 51 has a sensor housing chamber 67. The sensor housing chamber 67 communicates with the second end of the branch flow path 66. The circuit board 63 and the pressure sensor 61 are housed in the sensor housing chamber 67. The pressure sensor 61 detects the pressure of the fluid flowing from the first output connection flow path 53 into the branch flow path 66. Therefore, the pressure sensor 61 detects the pressure of the fluid flowing through the first output connection flow path 53. In this way, the pressure sensor 61 detects the pressure of the fluid output to the first pressure acting chamber 44.

[0042] The spacer 51 has a wiring insertion hole 68. The first end of the wiring insertion hole 68 communicates with the sensor housing chamber 67. The second end of the wiring insertion hole 68 opens to the second opposing surface 51b of the spacer 51. The wiring 65 is inserted inside the wiring insertion hole 68.

[0043] The manifold base 31 has a substrate accommodation chamber 69. The substrate accommodation chamber 69 communicates with the second end of the wiring insertion hole 68. A control board 64 and a microcomputer 62 are accommodated in the substrate accommodation chamber 69.

[0044] The pressure of the fluid detected by the pressure sensor 61 is output to the microcomputer 62 via the circuit board 63, the wiring 65, and the control board 64. The microcomputer 62 is electrically connected to an external control device. The microcomputer 62 transmits information regarding the pressure of the fluid output from the pressure sensor 61 to the external control device.

[0045] The microcomputer 62 stores in advance a determination program for determining whether or not a fluid leak has occurred based on the pressure detected by the pressure sensor 61 when the solenoid valve 11 is switched to the holding state. Therefore, the microcomputer 62 functions as a determination unit that determines whether or not a fluid leak has occurred based on the pressure detected by the pressure sensor 61 when the solenoid valve 11 is switched to the holding state.

[0046] The microcomputer 62 stores in advance a conversion program for converting the amount of pressure drop detected by the pressure sensor 61 into a pressure drop rate. In the conversion program, the amount of pressure drop detected by the pressure sensor 61 is differentiated to convert it into a pressure drop rate. In the determination program, it is determined that no fluid leak has occurred when the pressure drop rate is not equal to or greater than a certain value. On the other hand, in the determination program, it is determined that a fluid leak has occurred when the pressure drop rate is equal to or greater than a certain value. Therefore, the microcomputer 62 converts the amount of pressure drop detected by the pressure sensor 61 into a pressure drop rate, and determines that a fluid leak has occurred when the pressure drop rate is equal to or greater than a certain value. The certain rate of the pressure drop rate, which is a threshold value for determining that a fluid leak has occurred, has been obtained in advance through experiments or the like.

[0047] [Operation of the Embodiment] Next, the operation of this embodiment will be described. When the electromagnetic valve 11 is switched to the holding state, for example, it is assumed that fluid leakage occurs on the first pressure acting chamber 44 side. In this case, as the pressure of the fluid in the first pressure acting chamber 44 drops, the pressures of the fluids filled in the first pipe 37, the first output flow path 33, the first output connection flow path 53, and the first output port A respectively drop. As a result, the pressure detected by the pressure sensor 61 drops.

[0048] The microcomputer 62 converts the amount of pressure drop detected by the pressure sensor 61 into a pressure drop rate. Then, the microcomputer 62 determines whether the pressure drop rate is equal to or higher than a certain value. When the microcomputer 62 determines that the pressure drop rate is equal to or higher than a certain value, it determines that fluid leakage has occurred, and transmits information to that effect to an external control device.

[0049] When the electromagnetic valve 11 is switched to the holding state, for example, it is assumed that fluid leakage occurs on the second pressure acting chamber 45 side. In this case, as the pressure of the fluid in the second pressure acting chamber 45 drops, the piston 42 in the cylinder tube 41 moves toward one stroke end in the axial direction of the cylinder tube 41. As a result, the pressure of the fluid in the first pressure acting chamber 44 also drops. Thereby, the pressures of the fluids filled in the first pipe 37, the first output flow path 33, the first output connection flow path 53, and the first output port A respectively drop. As a result, the pressure detected by the pressure sensor 61 drops. The microcomputer 62 determines that fluid leakage has occurred in the same procedure as when fluid leakage occurs on the first pressure acting chamber 44 side, and transmits information to that effect to an external control device.

[0050] [Effects of the Embodiment] In the above embodiment, the following effects can be obtained. (1) For example, consider a case where at least one of the fluid output from the first output port A to the first pressure acting chamber 44 and the fluid output from the second output port B to the second pressure acting chamber 45 leaks when the solenoid valve 11 is switched to the holding state. In this case, the pressure detected by the pressure sensor 61 drops. Thus, when the pressure detected by the pressure sensor 61 drops, the microcomputer 62 determines that a fluid leak has occurred. Therefore, the operation detection device 60 of the actuator 40 does not need to include a pressure sensor for detecting the pressure of the fluid output to the first pressure acting chamber 44 and a pressure sensor for detecting the pressure of the fluid output to the second pressure acting chamber 45, respectively. Therefore, for example, compared with an operation detection device that includes a pressure sensor for detecting the pressure of the fluid output to the first pressure acting chamber 44 and a pressure sensor for detecting the pressure of the fluid output to the second pressure acting chamber 45, respectively, the number of wirings 65 can be reduced and miniaturization can be achieved.

[0051] (2) Since the microcomputer 62 converts the amount of pressure drop detected by the pressure sensor 61 into a pressure drop rate and determines that a fluid leak has occurred when the pressure drop rate is equal to or greater than a certain value, it is possible to accurately determine that a fluid leak has occurred.

[0052] (3) The pressure of the fluid flowing through the first output connection flow path 53 is the pressure of the fluid output to the first pressure acting chamber 44. And the pressure sensor 61 detects the pressure of the fluid flowing through the first output connection flow path 53. According to this, with the solenoid valve 11 and the manifold base 31 remaining in the existing configuration, based on the pressure detected by the pressure sensor 61 when the solenoid valve 11 is switched to the holding state, the microcomputer 62 can determine whether a fluid leak has occurred.

[0053] (4) The spacer 51 has a branch flow path 66 that branches off from the first output connection flow path 53. The pressure sensor 61 detects the pressure of the fluid flowing from the first output connection flow path 53 into the branch flow path 66. Such a configuration is suitable as a configuration in which the spacer 51 includes the pressure sensor 61 that detects the pressure of the fluid flowing through the first output connection flow path 53.

[0054] [Modification Example] Note that the above embodiment can be implemented with the following modifications. The above embodiment and the following modification examples can be implemented in combination with each other as long as they do not technically conflict with each other.

[0055] · In the embodiment, the branch flow path 66 may branch off from the second output connection flow path 54 instead of branching off from the first output connection flow path 53. In this case, the pressure sensor 61 detects the pressure of the fluid flowing from the second output connection flow path 54 into the branch flow path 66. Therefore, the pressure sensor 61 may detect the pressure of the fluid flowing through the second output connection flow path 54. In short, the branch flow path 66 only needs to branch off from one of the first output connection flow path 53 and the second output connection flow path 54. And the pressure sensor 61 only needs to detect the pressure of the fluid flowing from one of the first output connection flow path 53 and the second output connection flow path 54 into the branch flow path 66. Thus, the pressure sensor 61 only needs to detect one of the pressure of the fluid flowing through the first output connection flow path 53 and the pressure of the fluid flowing through the second output connection flow path 54. In short, the pressure sensor 61 only needs to be configured to detect one of the pressure of the fluid output to the first pressure acting chamber 44 and the pressure of the fluid output to the second pressure acting chamber 45.

[0056] · In the embodiment, the pressure sensor 61 may be configured to detect, for example, the pressure of the fluid flowing through the first output flow path 33. Also, the pressure sensor 61 may be configured to detect the pressure of the fluid flowing through the first output port A. In such a case, the operation detection device 60 may be configured not to include the spacer 51. Therefore, the spacer 51 does not have to be interposed between the manifold base 31 and the solenoid valve 11.

[0057] ·In the embodiment, the microcomputer 62 may be configured to determine that a fluid leak has occurred when the amount of pressure drop detected by the pressure sensor 61 is equal to or greater than a certain value. In short, the microcomputer 62 does not necessarily have to convert the amount of pressure drop detected by the pressure sensor 61 into a pressure drop rate.

[0058] ·In the embodiment, the operation detection device 60 may include, separately from the microcomputer 62, a determination unit that determines whether or not a fluid leak has occurred based on the pressure detected by the pressure sensor 61 when the solenoid valve 11 is switched to the holding state.

[0059] ·In the embodiment, the solenoid valve 11 may be, for example, a 4-port solenoid valve in which the second discharge port R2 is omitted.

Explanation of Reference Numerals

[0060] 11... Solenoid valve, 31... Manifold base, 33... First output flow path, 34... Second output flow path, 40... Actuator, 43... Piston rod, 44... First pressure acting chamber, 45... Second pressure acting chamber, 51... Spacer, 53... First output connection flow path, 54... Second output connection flow path, 60... Operation detection device, 61... Pressure sensor, 62... Microcomputer functioning as a determination unit, 66... Branch flow path, A... First output port, B... Second output port.

Claims

1. An actuator operation detection device in which a piston rod reciprocates by fluids output from a first output port of a solenoid valve having a first output port and a second output port to a first pressure acting chamber and from the second output port to a second pressure acting chamber, and the solenoid valve switches to a holding state capable of holding the pressure of the fluid output from the first output port to the first pressure acting chamber and the pressure of the fluid output from the second output port to the second pressure acting chamber, respectively, thereby holding the piston rod, comprising: a pressure sensor that detects one of the pressure of the fluid output to the first pressure acting chamber and the pressure of the fluid output to the second pressure acting chamber; a determination unit that determines whether or not fluid leakage has occurred based on the pressure detected by the pressure sensor when the solenoid valve has switched to the holding state. The actuator operation detection device is characterized by comprising the above.

2. The determination unit according to claim 1, wherein the determination unit converts the amount of pressure drop detected by the pressure sensor into a pressure drop rate, and determines that fluid leakage has occurred when the drop rate is equal to or higher than a certain level. The actuator operation detection device according to claim 1 is characterized by this.

3. A spacer is provided between a manifold base having a first output flow path that communicates with the first output port and outputs fluid to the first pressure acting chamber, and a second output flow path that communicates with the second output port and outputs fluid to the second pressure acting chamber, and the solenoid valve, The spacer is a first output connection flow path that connects the first output port and the first output flow path; a second output connection flow path that connects the second output port and the second output flow path. The actuator operation detection device according to claim 1 or claim 2 is characterized in that the pressure sensor detects one of the pressure of the fluid flowing through the first output connection flow path and the pressure of the fluid flowing through the second output connection flow path.

4. The spacer has a branch flow path that branches from one of the first output connection flow path and the second output connection flow path, The actuator operation detection device according to claim 3 is characterized in that the pressure sensor detects the pressure of the fluid flowing from one of the first output connection flow path and the second output connection flow path into the branch flow path. ​

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