Valve and Fluid Control Device

Abstract

To provide a valve capable of accurately detecting operation of a valve.SOLUTION: A valve 1 is equipped with a valve body 2 defining a fluid channel, a diaphragm 30 operating the fluid channel so as to open / close, an actuator 4 driving the valve body by supplying or shutting down working fluid, a stem 40 transmitting driving force of the actuator 4 to the diaphragm 30, an open / close detection sensor 50 detecting open / close action of the diaphragm 30, and an O-ring 66 fixing a ring-shaped magnet 501 inserted at one end of the stem 40 with respect to the stem 40. The open / close detection sensor 50 is equipped with the magnet 501 fixed by the O-ring, and a magnetic sensor 502 detecting changes of a magnetic field of the magnet 501.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a valve provided with a sensor inside the device and capable of outputting data detected by the sensor.

Background Art

[0002] Conventionally, there are many valves equipped with sensors to confirm the opening and closing operations of the valves. Among such valves, especially in the case of valves for integration, sensors and operation parts are provided on the upper part or the upper surface of the valve so that operations such as installation and removal of the valve from the upper part of the valve, or operations such as supply of driving pressure and driving operation can be performed. And when designed in this way, in many cases, the opening and closing operation of the valve is detected by the vertical movement of the piston.

[0003] In this regard, for example, in Patent Document 1, there is provided a chemical solution air operation valve having a piston rod that reciprocates within the valve body to open or close the valve, and an indicating member that is connected to the piston rod and inserted through a through hole of the valve body, and a detection switch that detects the location of the tip portion of the indicating member, and a case that covers the detection switch and the tip portion of the indicating member and is attached to the valve body. Also, in Patent Document 2, there is proposed an air operation valve provided with an actuator that raises and lowers a stem by supplying or blocking a working fluid, and having an opening / closing detection sensor that detects the opening and closing of a valve body accompanying the raising and lowering of a piston based on a change in the distance to the piston.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when detecting the operation of the valve according to the operation of the piston that opens and closes the valve, if the piston tilts, the detection target tilts, accurate detection cannot be performed, and there is a possibility of detection failure. Also, if the movement amount (stroke amount) of the piston is small, it may further affect the detection accuracy.

[0006] Therefore, one of the objects of the present invention is to provide a valve capable of accurately detecting the operation of the valve.

Means for Solving the Problems

[0007] To achieve the above object, a valve according to the present invention includes a valve body that defines a fluid flow path, a valve element that operates to open and close the fluid flow path, an actuator that drives the valve element by supplying or blocking an operating fluid, a stem that transmits the driving force of the actuator to the valve element, a detection means that detects the opening and closing operation of the valve element, and an elastic member that fixes a ring-shaped magnetic body inserted through one end of the stem to the stem. The detection means includes the magnetic body fixed by the elastic member and a magnetic sensor that detects a change in the magnetic field of the magnetic body.

[0008] A recess may be provided along the circumferential direction on the outer peripheral surface of the stem to which the magnetic body is fixed, and an inclined portion that expands in diameter toward the outside may be provided at the end of the recess.

[0009] The actuator includes a pressure chamber into which the operating fluid is supplied, and an actuator cap that projects one end of the stem to the outside from the inside on the side opposite to the valve element. The actuator further includes a sensor cap that covers the detection means together with one end of the stem. A bolt inserted through a bolt hole of the sensor cap may be fastened to a fastening groove provided on the outer peripheral surface of the actuator cap.

[0010] In the vicinity of the opening of the fastening groove, an inclined portion that expands in diameter toward the outside may be formed.

[0011] The magnetic sensor may be attached to the outer surface of the actuator cap.

[0012] The magnetic sensor may be attached inside the sensor cap.

[0013] It may be configured as a fluid control device including the valve.

Advantages of the Invention

[0014] According to the valve of the present invention, the operation of the valve can be accurately detected.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Best Mode for Carrying Out the Invention

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the external appearance of an air operation valve (hereinafter, also simply referred to as valve 1) provided with a sensor unit 5 according to an embodiment of the present invention, and FIG. 2 shows a longitudinal section when the valve of valve 1 is closed. In the following description, for convenience, the directions of members and the like may be referred to as up, down, left, and right according to the directions on the drawing, but these do not limit the directions of members and the like during the implementation or use of the present invention.

[0017] Valve 1 is a direct touch type metal diaphragm valve capable of highly accurately controlling a minute flow rate of a process fluid, and includes a valve body 2, a diaphragm 30, a bonnet 31, a bonnet nut 32, an actuator 4, a sensor unit 5, and the like. Valve 1 is used, for example, in a semiconductor manufacturing apparatus that utilizes a film forming technique of the ALD (Atomic Layer Deposition) method.

[0018] ● Valve body 2 The valve body 2 is formed of a metal material such as stainless steel and defines a fluid flow path. Two flow ports are provided at the lower part of the valve body 2, and a fluid inflow path 20 and a fluid outflow path 21 are formed from each flow port. An upwardly open valve chamber 22 having a substantially concave cross section is formed at the upper part of the valve body 2 and communicates with the fluid inflow path 20 and the fluid outflow path 21. A valve seat 23 made of synthetic resin is provided on the bottom surface of the valve chamber 22, and an annular step portion 24 is formed on the lower side of the inner peripheral surface of the valve chamber 22.

[0019] ● Diaphragm 30 The diaphragm 30 is a valve body that can open and close a fluid flow path, has an extremely thin thickness, and is formed of a metal material such as stainless steel or other shape memory alloys. This diaphragm 30 is disposed above the valve seat 23 and is composed of a plurality of diaphragms. Further, the diaphragm 30 has a dish shape with the central portion curved upward in a natural state.

[0020] The retainer adapter 44 is an annular member attached to the inner peripheral surface of the valve chamber 22, and is pressed by the cylindrical lower end portion of the bonnet 31 toward the stepped portion 24. The peripheral edge portion of the diaphragm 30 is clamped and fixed by the stepped portion 24 and the retainer adapter 44, and the airtightness of the valve chamber 22 is maintained.

[0021] ● Bonnet 31 The bonnet 31 is formed in a substantially lid-shaped cylindrical form, and its cylindrical lower end portion is inserted into the valve chamber 22 of the valve body 2 and screwed to the cylindrical upper portion of the valve body 2. Inside the bonnet 31, a stem 40 is disposed so as to be able to move up and down, and a coiled spring 42 is disposed around the stem 40. The spring 42 biases downward the enlarged diameter portion 403 formed at the lower portion of the stem 40. A diaphragm presser 43 made of synthetic resin that can abut against the upper surface of the central portion of the diaphragm 30 is fitted to the lower surface of the enlarged diameter portion 403.

[0022] ● Actuator 4 The actuator 4 is a fluid-operated drive mechanism that moves the stem 40 up and down by supplying or blocking the operating fluid from a fluid supply source (not shown), and thereby opens and closes the valve 1 by bringing the diaphragm 30, which is the valve element, into contact with and away from the valve seat 23. The actuator 4 includes a housing 45, two pressure chambers 46 partitioned vertically inside the housing 45, two pistons 47 disposed vertically inside the housing 45 facing the respective pressure chambers 46, and one partition member 48 disposed between the pistons 47 inside the housing 45. In addition, the actuator 4 may include a stroke adjustment mechanism capable of adjusting the stroke amount due to the up and down movement of the stem 40.

[0023] Figure 3 shows an enlarged view of the actuator 4. The housing 45 is formed by coupling an upper actuator cap 451 and a lower actuator body 452 by screwing.

[0024] The actuator cap 451 houses the pressure chamber 46 to which the working fluid is supplied therein, and projects one end of the stem 40 to the outside from the inside, on the side opposite to the diaphragm 30. That is, a through hole 45a is formed in the upper part of the actuator cap 451, and the stem 40 is inserted into the through hole 45a and housed in the sensor unit 5. The flow path 41 formed in the stem 40 is composed of an axial hole 41a extending in the axial direction of the stem 40 and two radial holes 41b branching radially from the axial hole 41a. The working fluid is supplied to the two pressure chambers 46 from the supply port 53a through the axial hole 41a and the radial holes 41b in sequence.

[0025] An opening 45d for inserting the stem 40 is formed in the cylindrical lower part 4521 of the actuator body 452. The actuator 4 is fastened and fixed to the bonnet 31 by screwing the cylindrical lower part 4521 to the bonnet 31 and tightening the bonnet nut 32. The stem 40 is supported in the housing 45 so as to be able to move up and down.

[0026] ● Stem 40 The stem 40 is composed of a stem body 401 that moves up and down in the bonnet 31 and a rod 402 that extends from the inside of the housing 45 of the actuator 4 to the sensor unit 5, and their upper and lower ends are screwed together and connected. Thereby, the stem body 401 and the rod 402 connected to each other integrally form the stem 40 and move up and down in the bonnet 31, the housing 45, and the sensor unit 5 described later.

[0027] The rod 402 constituting the stem 40 is inserted into the through hole 45a formed in the upper surface of the actuator cap 451 and housed in the sensor unit 5. The rod 402 is provided with a flow path 41 for the working fluid, and this flow path 41 communicates with the supply port 53a for the working fluid formed in the upper surface of the sensor cap 53. Thereby, the working fluid supplied from the fluid supply source flows into the flow path 41 through the supply port 53a.

[0028] The two pistons 47 are connected to a rod 402 that constitutes the stem 40, and are accommodated in the housing 45 together with the rod 402 so as to be able to move up and down. Each piston 47 has a sliding outer peripheral surface 47a, a first pressure-receiving surface 47b, and an inner peripheral surface 47c. The sliding outer peripheral surface 47a is slid on the inner wall 45e of the housing 45 via an O-ring 61 as the stem 40 moves up and down. The first pressure-receiving surface 47b is annular, partitions the pressure chamber 46 together with the inner wall 45e, and receives the pressure of the working fluid.

[0029] Below the lower piston 47, the pressure chamber 46 is partitioned by the first pressure-receiving surface 47b, the inner wall 45e, and the bottom wall 45f of the housing 45 which is a part of the inner wall 45e. The inner peripheral surface 47c of the piston 47 is fixed to the outer peripheral surface 40a of the stem 40 by an interference fit that is not a press fit like an interference fit via an O-ring 62, but a fit of an intermediate fit. A first fitting portion 471 is formed on the inner peripheral surface 47c.

[0030] A flange portion 404 is provided on the stem 40. The flange portion 404 is formed by expanding the outer peripheral surface 40a of the stem 40, and the lower surface 404a of the flange portion 404 is in contact with the upper surface 47d of the upper piston 47. Thus, when the working fluid is supplied to the pressure chamber 46, the stem 40 is pushed up and rises together with the piston 47 by the pressure of each pressure chamber 46.

[0031] When assembling the valve 1, the O-ring 62 is fitted into the first fitting portion 471 either before or after connecting the piston 47 to the stem 40. Since the piston 47 is not press-fitted into the stem 40, damage, entrapment, and breakage of the O-ring 62 can be reliably prevented, and the sealing function of each pressure chamber 46 is realized.

[0032] In addition, the state of the O-ring 62 can be easily visually confirmed from the first fitting portion 471. Therefore, even if damage, entrainment, or fracture of the O-ring 62 should occur, these states can be detected at an early stage. Further, the O-ring 62 is fitted into the first fitting portion 471 with friction while applying its own elastic force due to crushing deformation to the inner wall of the first fitting portion 471. For this reason, the O-ring 62 will not fall off even when the piston 47 moves up and down.

[0033] Furthermore, since the O-ring 62 is exposed to the pressure chamber 46, when the valve 1 is fully opened, the O-ring 62 is pressed against the inner wall of the first fitting portion 471 by the pressure of the working fluid acting on the pressure chamber 46. Due to this pressing force, the crushing deformation of the O-ring 62 in the first fitting portion 471 is further promoted, and the sealing performance of each pressure chamber 46 is further improved.

[0034] Furthermore, since the O-ring 62 is exposed to the pressure chamber 46 and comes into contact with the working fluid, it may thermally expand according to the temperature of the working fluid. When such thermal expansion of the O-ring 62 occurs in a fitting groove with a limited space as in the prior art, the thermal expansion is restricted and there is no place for heat to escape, so that the O-ring 62 may be deteriorated such as hardened, softened, or swollen.

[0035] However, in the case of the present embodiment, the O-ring 62 is fitted into the first fitting portion 471, and a certain degree of freedom of thermal expansion is ensured, and a certain degree of heat escape path is ensured. For this reason, the deterioration of the O-ring 62 due to the thermal expansion and the influence on the sealing performance of the pressure chamber 46 are reduced.

[0036] The partition member 48 is fixed to the inner wall 45e between the two pistons 47, and partitions the upper pressure chamber 46 together with the first pressure receiving surface 47b of the upper piston 47 and the inner wall 45e. Specifically, the partition member 48 has a sliding inner peripheral surface 48a, a second pressure receiving surface 48b, and a fixed outer peripheral surface 48c. The sliding inner peripheral surface 48a is slid on the outer peripheral surface 40a of the stem 40 via an O-ring 63 as the stem 40 moves up and down.

[0037] The second pressure receiving surface 48b is annular and partitions the pressure chamber 46 together with the inner wall 45e and the first pressure receiving surface 47b, and receives the pressure of the working fluid. The fixed outer peripheral surface 48c is fixed to the inner wall 45e via an O-ring 63. The sliding inner peripheral surface 48a slides on the outer peripheral surface 40a of the stem 40 as the stem 40 moves up and down. Further, a second fitting portion 481 is formed on the sliding inner peripheral surface 48a.

[0038] The second fitting portion 481 is formed by cutting out corners extending from the sliding inner peripheral surface 48a to the second pressure receiving surface 48b over the entire circumference, and the O-ring 64 is fitted therein. Thereby, the stem 40 slides in an airtight manner with respect to the partitioning member 48, and the sealing function of the upper pressure chamber 46 is ensured. Further, the O-ring 64 is fitted into the second fitting portion 481 with friction due to its own elastic force caused by crushing and deformation, similar to the case of the O-ring 62.

[0039] Therefore, the O-ring 64 does not fall off even when the stem 40 moves up and down. Further, the O-ring 64 is exposed to the pressure chamber 46, similar to the case of the O-ring 62. For this reason, when the valve 1 is fully opened, the O-ring 64 is pressed against the inner wall of the second fitting portion 481 by the pressure of the working fluid acting on the pressure chamber 46. Due to this pressing force, the crushing and deformation of the O-ring 64 in the second fitting portion 481 is further promoted, and the sealing performance of the upper pressure chamber 46 is further improved.

[0040] Furthermore, since the O-ring 64 is fitted into the second fitting portion 481, thermal expansion is allowed to a certain extent, similar to the case of the O-ring 62. Therefore, the adverse effects caused by the thermal expansion of the O-ring 64 in a limited space as in the prior art, that is, the deterioration of the O-ring 64 and the influence on the sealing performance of the lower pressure chamber 46 are reduced.

[0041] Furthermore, the bottom wall 45f of the housing 45 has the same function as the partitioning member 48 in terms of partitioning the lower pressure chamber 46, and the O-ring 65 is fitted into the third fitting portion 4522 provided on the bottom wall 45f and exposed to the pressure chamber 46, and has the same function as the O-ring 64. Therefore, the sealing function of the lower pressure chamber 46 is also ensured.

[0042] On the first pressure receiving surface 47b, a countersunk portion 49 is formed such that when the first pressure receiving surface 47b contacts the second pressure receiving surface 48b or the bottom wall 45f as the stem 40 descends, the radial hole 41b of the flow path 41 communicates therewith. Here, if the stroke amount of the stem 40 is increased by the stroke adjustment mechanism, the first pressure receiving surface 47b may contact the second pressure receiving surface 48b or the bottom wall 45f as the stem 40 descends. When the first pressure receiving surface 47b contacts the second pressure receiving surface 48b or the bottom wall 45f, a necessary volume cannot be secured in the pressure chamber 46, and also, since the radial hole 41b is blocked, malfunction of the valve 1 may occur. Also, the O-ring 62 may contact the partitioning member 48 and the O-ring 62 may be damaged.

[0043] However, by forming the countersunk portion 49 on the first pressure receiving surface 47b, even when the first pressure receiving surface 47b contacts the second pressure receiving surface 48b, the radial hole 41b is opened in the space of the countersunk portion 49, so that the working fluid can be supplied to the space. Therefore, the space of the countersunk portion 49 is secured as the pressure chamber 46.

[0044] Also, in order to avoid contact between the first pressure receiving surface 47b, the second pressure receiving surface 48b, and the bottom wall 45f, it is not necessary to secure a large pressure chamber 46 when the valve 1 is fully closed with a safety margin, and it is not necessary to secure the outer shape of the actuator 4 to be long in the axial direction. Therefore, while ensuring the reliability of the actuator 4 and thus the valve 1, the valve 1 can be miniaturized.

[0045] Also, the stroke amount of the stem 40 can be adjusted to be small by the stroke adjustment mechanism to improve the responsiveness and controllability of the opening and closing operation of the valve 1. Further, the O-ring 62, the O-ring 64, and the O-ring 65 are exposed to the countersunk portion 49 when the first pressure receiving surface 47b contacts the second pressure receiving surface 48b as the stem 40 descends.

[0046] Accordingly, when the working fluid is supplied to the pressure chamber 46 when shifting from the fully closed state to the fully open state of the valve 1, the O-ring 62, the O-ring 64, and the O-ring 65 are pressed by the working fluid and crushed and deformed in the space of the countersunk portion 49. Therefore, even when the first pressure receiving surface 47b and the second pressure receiving surface 48b are in contact, the sealing function of each pressure chamber 46 is ensured by forming the countersunk portion 49.

[0047] ● Opening and closing operation of the valve Here, the opening and closing operation of the valve 1 will be described. When the working fluid is supplied from the supply port 53a to the two pressure chambers 46 through the flow path 41, the piston 47 and the stem 40 are pulled up and lifted against the elastic force of the spring 42 by the pressure in each pressure chamber 46. As a result, the diaphragm 30 returns to its natural state with a convex cross-section by its own restoring force and separates from the valve seat 23, and the valve 1 is in the valve open state.

[0048] On the other hand, when the supply of the working fluid from the supply port 53a is stopped and the pressure in the flow path 41 and the two pressure chambers 46 is released, the piston 47 and the stem 40 are lowered by the elastic force of the spring 42. As a result, the diaphragm 30 has its central portion pressed downward by the diaphragm retainer 43, is deformed into a concave cross-section against its own restoring force, and comes into contact with the valve seat 23, and the valve 1 is in the valve closed state.

[0049] ● Sensor unit 5 The sensor unit 5 is a functional unit that senses the operation of the valve 1 and is provided above the actuator 4 as shown in FIGS. 2 to 5. This sensor unit 5 includes an opening / closing detection sensor 50 composed of a magnet 501 and a magnetic sensor 502, and a sensor cap 53, and the opening / closing detection sensor 50 is housed in the sensor cap 53.

[0050] The sensor cap 53 is attached above the actuator cap 451 and covers the opening / closing detection sensor 50 and the like together with the portion of the stem 40 protruding from the actuator cap 451. On the upper surface of the sensor cap 53, there are provided a supply port 53a for the working fluid, a cable outlet 53b for leading out the cable 56 to the outside, and a through-hole 53c into which the LED cap 53d is fitted.

[0051] At a portion communicating with the supply port 53a for the working fluid and corresponding to the upper end portion of the stem 40, an annular fourth fitting portion 533 is formed. An O-ring 67 is fitted into the fourth fitting portion 533, thereby maintaining the airtightness between the sensor cap 53 and the stem 40 in the vicinity of the supply port 53a.

[0052] A cable holder 561 for holding the cable 56 is provided at the cable outlet 53b, and the cable holder 561 prevents the cable 56 from wobbling or bending at the cable outlet 53b portion. The LED cap 53d is a member having translucency and having a shape conforming to the shape of the through-hole 53c. When the LED cap 53d is fitted into the through-hole 53c, the light of the LED housed in the sensor cap 53 can be transmitted to the outside.

[0053] On the side surface of the sensor cap 53, bolt holes 53e for attaching the sensor cap 53 to the actuator cap 451 are formed. As shown in FIGS. 6 and 7, the bolt holes 53e are composed of a diameter-expanded portion 531 having a shape conforming to the shape of the bolt 53f and having a taper formed so as to expand in diameter toward the outside, and a hole portion 532 having a shape conforming to the shaft portion of the bolt 53f. On the inner peripheral surface of the hole portion 532, a female thread corresponding to the male thread formed on the outer peripheral surface of the bolt 53f is formed so as to be screwed onto the bolt 53f.

[0054] Above the outer peripheral surface of the actuator cap 451 to which the sensor cap 53 is attached, a concave fastening groove 45c is formed that covers the lower part of the sensor cap 53 and to which the tip of the bolt 53f is fastened. When the sensor cap 53 is placed over the actuator cap 451 from above, the bolt hole 53e is positioned at the location where the fastening groove 45c is formed. In addition, near the opening of the fastening groove 45c, an inclined portion 4511 with a taper formed so as to increase in diameter toward the outside is provided.

[0055] Here, with reference to FIG. 7, the mounting process of the sensor cap 53 and the actuator cap 451 will be described. First, as shown in FIG. 7(a), the sensor cap 53 is placed over the actuator cap 451. Next, as shown in FIG. 7(b), the bolt 53f is inserted through the bolt hole 53e of the sensor cap 53 into the fastening groove 45c of the actuator cap 451, and the male thread of the bolt 53f and the female thread of the hole portion 532 are screwed together. At this time, the tip of the shaft rod portion of the bolt 53f is guided toward the back of the hole portion 532 while contacting the enlarged diameter portion 531. As it is, as shown in FIG. 7(c), while screwing the bolt 53f into the bolt hole 53e, it is fastened to the bottom of the fastening groove 45c. At this time, the tip of the shaft rod portion of the bolt 53f is guided to the bottom of the fastening groove 45c by the inclined portion 4511 formed in the fastening groove 45c of the actuator cap 451. When the tip of the shaft rod portion of the bolt 53f comes into pressure contact with the bottom of the fastening groove 45c, the sensor cap 53 is fixed to the actuator cap 451 so as not to rotate.

[0056] As a result of fixing the sensor cap 53 with the bolt 53f to the fastening groove 45c provided in the actuator cap 451 in this way, unlike the case where the sensor cap 53 is screwed on while being rotated with respect to the actuator cap 451, the cable outlet 53b of the sensor cap 53, the cable 56, and the LED cap 53d and the LED 57 are easily aligned. In addition, even when the cable 56 is led out from the cable outlet 53b, it can be fixed without applying a load to the cable 56. In addition, since the sensor cap 53 is attached to the actuator cap 451 by fastening bolts 53f at three locations from the side, the sensor cap 53 does not tilt with respect to the actuator cap 451. Furthermore, the inclined portion 4511 formed in the fastening groove 45c of the actuator cap 451 serves as a guide, making the axial fastening positions of the three bolts 53f equal and preventing the sensor cap 53 from tilting.

[0057] ● Opening / closing detection sensor 50 In this embodiment, the opening / closing detection sensor 50 is attached to the upper surface of the outer surface of the actuator cap 451. This opening / closing detection sensor 50 constitutes a detection means for detecting the opening and closing of the diaphragm 30 accompanying the raising and lowering of the stem 40, that is, the opening and closing operation of the valve 1, based on the change in the magnetic field due to the raising and lowering of the magnet 501 attached to the stem 40. Furthermore, based on the change in the magnetic field, it is also possible to detect or calculate the pressure in the pressure chamber 46, the stroke amount of the diaphragm retainer 43, the thrust of the piston 47, and the average moving speed. The information obtained by this opening / closing detection sensor 50 can be used for abnormality determination of the operation of the valve 1 and the like.

[0058] As shown in FIGS. 3 and 4, the magnet 501 is a ring-shaped magnetic body and is attached to a stepped portion provided on the stem 40 so that the stem 40 protruding upward from the through hole 45a of the actuator cap 451 passes through. As a result of the magnet 501 being ring-shaped, no matter where the magnetic sensor 502 is provided around the stem 40, the magnetic field emitted by the magnet 501 can be reliably and accurately detected.

[0059] Also, an O-ring 66 is provided at a predetermined position on the stem 40 as an elastic member for fixing the magnet 501 to the stem 40. This O-ring 66 contacts the magnet 501 from above and fixes the magnet 501 at a predetermined position on the stem 40. Here, as shown in FIG. 6, an annular recess 40b is formed in a portion of the outer peripheral surface 40a of the stem 40 that extends from the through-hole 45a of the actuator cap 451. This recess 40b is formed at regular intervals along the circumferential direction of the stem 40. Further, inclined portions 405 having a taper formed so as to increase in diameter from the inner side to the outer side are provided at the upper and lower ends of the recess 40b.

[0060] As a result of the O-ring 66 fitting into the recess 40b, the O-ring 66 presses down the magnet 501 without shifting in the axial direction of the stem 40, and the magnet 501 is securely fixed in place. In particular, the O-ring 66 contacts the upper inclined portion 405 of the recess 40b so as to be pushed downward, thereby pressing the magnet 501 from above to below and firmly fixing it. Further, since the upper surface of the magnet 501 is in contact with the O-ring 66 over the entire circumference and frictional resistance is generated, the rotation of the magnet 501 in the circumferential direction with respect to the stem 40 is prevented. Also, by fixing with the elastic member of the O-ring 66, vibrations during the opening and closing operation of the valve 1 transmitted from the stem 40 to the magnet 501 can be suppressed. As a result, the magnetic sensor 502 can accurately detect the magnetic field emitted by the magnet 501 that moves only in the vertical direction. Furthermore, the attachment and detachment of the magnet 501 can be performed by attaching and detaching the O-ring 66, which is simple.

[0061] Note that since the stem 40 is fixed so as to be vertically movable by the O-rings 65 and 67, it moves vertically without tilting along the axial direction. Also, since the stem 40 is held by a plurality of O-rings, it does not rotate due to a spring 42 wound around the stem 40 or the like. Therefore, the magnet 501 does not rotate together with the stem 40.

[0062] Also, in the present embodiment, the diameter of the stem 40 is slightly smaller than other portions at the position where the magnet 501 is attached, and the lower end surface of the magnet 501 is supported so as to be in contact with the stepped surface of the stem 40 without a gap.

[0063] The magnetic sensor 502 is a non-contact sensor that utilizes, for example, the Hall effect. It detects the magnetic field emitted by the magnet 501 and converts the change in the magnetic field into an electrical signal for output. Note that the operation type of the magnetic sensor 502 is not limited, and for example, a latch type or a switch type may be used. Also, those using a coil or those using an AMR element whose resistance value changes depending on the strength and direction of the magnetic field may be used. As long as the position of the magnet 501 can be detected non-contact by combining with the magnet 501, it is acceptable.

[0064] As shown in FIGS. 4 and 5, the magnetic sensor 502 is clamped and fixed by a sensor base 51 and a sensor holder 52. In this embodiment, the sensor base 51 has a rectangular parallelepiped shape and includes an elongated hole 51a for fixing to the upper surface of the actuator cap 451 with a bolt 51b, and a bolt hole 51c for attaching the sensor holder 52.

[0065] The elongated hole 51a is an oval hole having a length in the radial direction of the stem 40 when the sensor base 51 is attached on the actuator cap 451. Thereby, the sensor base 51 can adjust the mounting position within the range where the bolt hole 45b of the actuator cap 451 and the elongated hole 51a of the sensor base 51 overlap. By adjusting the mounting position of the sensor base 51 within the range of the length of the oval shape of the elongated hole 51a, the sensor holder 52 can be brought closer to or conversely moved away from the magnet 501 attached to the stem 40 and fixed, and the distance between the magnetic sensor 502 held by the sensor holder 52 and the magnet 501 can be adjusted. In such a configuration, it can be said that the elongated hole 51a constitutes an adjustment means for adjusting the distance between the magnetic sensor 502 and the magnet 501.

[0066] In this embodiment, the sensor holder 52 is formed of a rectangular plate-like member, has a pair of bolt holes 52a into which a bolt 51d is screwed, and an opening 52b is provided between the pair of bolt holes 52a. The sensor holder 52 is adapted to be attached to the surface of the sensor base 51 on the stem 40 side, and is fixed to the sensor base 51 in a state where the magnetic sensor 502 is sandwiched by a bolt 51d screwed into the bolt hole 52a through the bolt hole 51c.

[0067] In a state where the magnetic sensor 502 is sandwiched between the sensor holder 52 and the sensor base 51, the magnetic sensor 502 is exposed from the opening 52b toward the magnet 501 side. Thereby, the magnetic sensor 502 can surely detect the magnetic field generated by the magnet 501.

[0068] The magnetic sensor 502 is connected to the circuit board 54. From the circuit board 54, the wirings 55 are aggregated and led out as a cable 56 to the outside of the valve 1 through the cable lead-out port 53b of the sensor cap 53. The circuit board 54 is configured with a processing module that transmits and receives information obtained by the magnetic sensor 502 and executes information processing based on the information. Thereby, information can be transmitted to an external terminal or the like through the cable 56.

[0069] In this embodiment, the circuit board 54 is attached to the upper surface of the actuator cap 451 together with the sensor base 51. Further, for example, a flexible printed circuit (FPC) is used for the circuit board 54, and the gap between members can be used as a wiring path to the magnetic sensor 502. Further, the processing module may be stored in the valve 1 separately from the circuit board 54, or may be configured as a part of the magnetic sensor 502.

[0070] An LED 57 is connected to the circuit board 54. The LED 57 is a notification means for notifying the detection result by the magnetic sensor 502, the analysis result based on the detection result, or the state information such as a detection error, and emits light in a predetermined color and emission pattern according to the notification content. The light of the LED 57 is visually recognized from the outside through the LED cap 53d.

[0071] According to the valve 1 according to the above-described embodiment, the operation of the valve 1 can be accurately detected. In particular, since the magnet 501 is securely fixed to the stem 40 and the stem 40 also exhibits stable behavior without tilting or the like, the detection accuracy of the opening / closing operation is high. Furthermore, the sensor unit 5 is provided above the valve 1, and it is easy to replace and visually check. In particular, since the sensor unit 5 is attached to the outside of the actuator cap 451, maintenance such as replacement of the sensor unit 5 itself or members such as the magnet 501 constituting the sensor unit 5 can be performed without touching parts that affect driving such as the pressure chamber 46 and the spring 42 of the actuator 4.

[0072] In another embodiment of the present invention, as shown in FIG. 8, the sensor base 51 and the circuit board 54 are attached to the inner top surface of the sensor cap 53, and thereby the opening / closing detection sensor 50 can also be attached inside the sensor cap 53. Thereby, by replacing the sensor cap 53, the opening / closing detection sensor 50 can be easily replaced. Also, the vibration of the actuator 4 is less likely to be transmitted to the opening / closing detection sensor 50, which is suitable for improving the detection accuracy.

[0073] In the above-described embodiment, the valve 1 may be provided with information display means such as a liquid crystal panel for displaying operation information and the like. Also, means for outputting a notification sound may be provided according to the processing result by the built-in software and the like.

[0074] Also, as shown in FIG. 9, a plurality of valves 1 having the above-described configuration are integrated to form a fluid control device 10 (gas unit) together with a flow rate control device 11 (hereinafter also referred to as a mass flow controller 11) and the like. The fluid control device 10 is composed of a plurality of gas lines 10A (three lines in FIG. 9) adjacent to each other in the width direction, and each gas line 10A is installed on a base sheet metal. A plurality of valves 1 and 7 connected via a block-shaped joint 12 are arranged side by side in a row on each gas line 10A on the substrate together with components such as the mass flow controller 11. In this embodiment, the valve 1 is provided on the downstream side of the flow control device 11, but it may be provided on the valve 7 side.

[0075] Further, the countersunk portion 49 and the actuator 4 may each be provided with one piston 47 and pressure chamber 46, or may be provided with two or more of each. Further, the actuator 4 and the sensor unit 5 are applicable not only to air operation valves but also to valves having other drive sources and drive targets other than valves. Further, the actuator cap 451 and the actuator body 452 are fastened by screwing, but may be fastened by other fastening methods. Further, the stem 40 is composed of a rod 402 and a stem body 401, but may be integrally formed. Further, in this embodiment, a two-way valve in which two flow paths, a fluid inflow path 20 and a fluid outflow path 21, are formed in the valve body 2 is shown, but a three-way valve having three flow paths may also be used.

Explanation of reference numerals

[0076] 1: Valve 2: Valve body 10: Flow control device 30: Diaphragm (valve element) 31: Bonnet 32: Bonnet nut 4: Actuator 40: Stem 401: Stem body 402: Rod 405: Inclined portion 42: Spring 451: Actuator cap 4511: Inclined portion 452: Actuator body 45a: Through hole 45b: Bolt hole 45c: Fastening groove 46: Pressure chamber 47: Piston 48: Partition member 5: Sensor unit 50: Open / close detection sensor (detection means) 501: Magnet (magnetic material) 502: Magnetic sensor 51: Sensor base 51a: Long hole 51b: Bolt 51c: Bolt hole 51d: Bolt 52: Sensor holder 52a: Bolt hole 52b: Opening 53: Sensor cap 53a: Supply port 53b: Cable outlet 53c: Through hole 53d: LED cap 53e: Bolt hole 53f: Bolt 54: Circuit board 55: Wiring 56: Cable 61, 62, 63, 64, 65, 66, 67: O-ring

Claims

1. A valve body defining a fluid flow path, A valve element that can open and close the fluid flow path, An actuator that drives the valve element by supplying or blocking the working fluid, A stem that transmits the driving force of the actuator to the valve element, Detection means for detecting the opening and closing operation of the valve element, An elastic member that fixes a ring-shaped magnetic body inserted through one end of the stem to the stem, and The detection means, The magnetic body fixed by the elastic member, and A magnetic sensor that detects a change in the magnetic field of the magnetic body, and A recess is provided along the circumferential direction on the outer peripheral surface of the stem to which the magnetic body is fixed, An inclined portion that expands in diameter toward the outside is provided at the end of the recess, The elastic member is fitted into the recess and contacts the magnetic body so as to be pushed down by the inclined portion to fix the magnetic body, Valve.

2. The actuator, An actuator cap that houses a pressure chamber to which the working fluid is supplied inside and projects one end of the stem to the outside from the inside to the side opposite to the valve element, and Further includes a sensor cap that covers the detection means together with one end of the stem, A bolt inserted through a bolt hole of the sensor cap is fastened to a fastening groove provided on the outer peripheral surface of the actuator cap, The valve according to claim 1.

3. An inclined portion that expands in diameter toward the outside is formed near the opening of the fastening groove, The valve according to claim 2.

4. The magnetic sensor is attached to the outer surface of the actuator cap, The valve according to claim 2 or 3.

5. The magnetic sensor is attached to the inside of the sensor cap, The valve according to claim 2 or 3.

6. A fluid control device comprising the valve according to any one of claims 1 to 5, Fluid control device.

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