JP5113774B2 - Fluid control valve - Google Patents

Description

  The present invention relates to a fluid control valve that controls the pressure of a fluid.

  There is a fluid control valve that controls the pressure of the fluid on the outlet side (secondary side) by adjusting the displacement of the valve body connected to the diaphragm (see, for example, Patent Document 1). As shown in FIG. 6, in the fluid control valve 820 described in Patent Document 1, a valve seat portion 825 is formed in a flow path 823 from an inlet 821 to an outlet 822 in an intermediate body 830 constituting the valve body. Yes. Then, by adjusting the displacement of the valve body 824 connected to the diaphragm 827, the distance between the valve seat portion 825 and the valve body 824 is adjusted to control the pressure of the fluid on the outlet 822 side (secondary side). ing.

JP 2008-202654 A JP 2000-193106 A

  By the way, since the fluid control valve 820 described in Patent Document 1 connects the diaphragm 827 and the valve body 824, when the pressure of the fluid on the outlet 822 side (secondary side) rises, the diaphragm 827 The force pulling the body 824 may increase, and the valve body 824 may be excessively pressed against the valve seat portion 825. In particular, when the fluid control valve 820 controls the pressure of a corrosive chemical solution, the intermediate body 830 and the valve body 824 are formed of a fluorine-based synthetic resin. For this reason, when the valve body 824 is excessively pressed against the valve seat portion 825, the intermediate body 830 and the valve body 824 may be damaged or deformed. As a result, the fluid sealing performance by the valve body 824 may be reduced.

  On the other hand, there is a fluid control valve in which a diaphragm and a valve body are fitted to be separable (see, for example, Patent Document 2). As shown in FIG. 7, in the fluid control valve 920 described in Patent Document 2, the pressure of the fluid on the outflow port 922 side (secondary side) rises to displace the diaphragm 927 to the side opposite to the valve body 924. The diaphragm 927 and the valve body 924 are configured to be separated when acted on. For this reason, it can suppress that the valve body 924 is pressed against the valve seat part 925 excessively. However, in the configuration in which the diaphragm 927 and the valve body 924 are separated, the valve body 924 is pressed against the valve seat 925 only by the urging force of the spring 932, so that the fluid sealing performance by the valve body 924 may be reduced. .

  The present invention has been made in view of the above circumstances, and provides a fluid control valve capable of suppressing the valve body from being excessively pressed against the valve seat portion and maintaining the fluid sealing performance of the valve body. The main purpose is to do.

  In order to solve the above-mentioned problems, the first invention includes a valve body having a fluid flow path therein and a valve seat portion provided in the middle of the flow path, and operating the flow path in the valve body. A diaphragm that is partitioned into a chamber, and a valve body that is integrated on the inner peripheral side of the diaphragm with respect to the diaphragm and that is displaced from a state of being seated on the valve seat portion to a state of being separated from the diaphragm, When the pressure of the fluid on the next side rises, the flexible portion of the diaphragm is displaced from the flow path side to the operation chamber side and the valve body is displaced in the direction of seating on the valve seat portion. A fluid control valve for controlling a secondary fluid by displacing the diaphragm and the valve body based on a pressure applied to the diaphragm from a chamber, wherein an outer peripheral edge and an inner peripheral edge of the flexible portion of the diaphragm The intermediate portion of the flexible portion is displaced from the flow path side to the operation chamber side from the restriction position in a state where the valve body is seated on the valve seat portion. It is characterized by comprising an intermediate restricting part for restricting.

  According to the first aspect of the present invention, the relative position between the valve seat and the valve body is adjusted by displacing the diaphragm and the valve body based on the pressure applied to the diaphragm from the operation chamber. The pressure and flow rate of the fluid on the side can be controlled. The intermediate restricting portion is displaced integrally with the intermediate portion between the outer peripheral edge and the inner peripheral edge of the flexible portion of the diaphragm, and in this state, the displacement of the intermediate portion is not restricted and applied to the entire diaphragm. The secondary fluid can be controlled based on the applied pressure.

  When the pressure of the fluid on the secondary side rises, the flexible part of the diaphragm is displaced from the flow path side to the operation chamber side, and the valve body is displaced in the direction of seating on the valve seat portion. The force in the direction of seating on the valve seat portion acting on the valve increases. And when the said valve body will be in the state seated on the said valve seat part, it will be controlled by the intermediate control part that the said intermediate part of the said flexible part will displace from the flow path side to the said operation chamber side rather than a control position. . In a state where the displacement of the intermediate portion is restricted, the intermediate restricting portion suppresses the pressure applied to the valve body by the fluid in the flow path from the intermediate portion of the flexible portion to the valve body, The pressure applied to the inner peripheral portion of the flexible portion is transmitted to the valve body by the inner peripheral portion. Here, the force by which the valve body is pulled by the pressure applied to the inner peripheral portion of the flexible portion is smaller than the force by which the valve body is pulled by the pressure applied to the entire flexible portion. Become. As a result, even when the pressure of the fluid on the secondary side increases, it is possible to suppress the valve body from being excessively pressed against the valve seat portion and to maintain the fluid sealing performance by the valve body.

  In the flexible portion of the diaphragm, the area on the inner peripheral side from the top of the bent portion is an effective pressure receiving area that generates a force for displacing the valve body. And the precision with which a fluid control valve controls a fluid becomes high, so that this effective pressure receiving area is large.

  In this regard, according to the second invention, in the first invention, the valve body is connected to the intermediate restricting portion and presses the valve body against each other in the displacement direction of the valve body in a state where the valve body is separated from the valve seat portion. On the other hand, it is characterized by comprising a press switching portion that is in a state in which the valve body is not pressed against the valve body in the displacement direction of the valve body when the valve body is seated on the valve seat portion.

  According to the second aspect of the present invention, the pressure switching portion is connected to the intermediate regulating portion, and the pressure switching portion and the valve body are pressed against each other in the displacement direction of the valve body in a state where the valve body is separated from the valve seat portion. Therefore, the relative displacement between the intermediate portion of the flexible portion and the valve body is limited in the displacement direction of the valve body. For this reason, in the flexible portion, the portion on the inner peripheral side with respect to the intermediate portion does not function as a diaphragm, and in the flexible portion, the portion on the outer peripheral side with respect to the intermediate portion functions as a diaphragm. Therefore, it is possible to suppress the flexible portion existing on the inner peripheral side from the intermediate portion from reducing the effective pressure receiving area, and to increase the effective pressure receiving area of the diaphragm to the portion on the outer peripheral side from the intermediate portion. As a result, it is possible to suppress a decrease in the accuracy with which the fluid control valve controls the fluid.

  In addition, when the valve body is seated on the valve seat portion, the pressure switching portion and the valve body are not pressed against each other in the displacement direction of the valve body, so that the fluid in the flow path applies to the flexible portion. The pressure that is applied is not transmitted to the valve body via the pressing switch. Then, in a state where the pressing switching portion and the valve body do not press each other in the displacement direction of the valve body, relative displacement between the intermediate portion of the flexible portion and the valve body can be allowed in the displacement direction of the valve body. When the width of the displacement of the intermediate portion of the flexible portion from the flow path side to the operation chamber side is increased by this relative displacement, the intermediate portion of the flexible portion is displaced from the flow path side to the operation chamber side from the restriction position as described above. Is regulated by the middle regulation department. Therefore, even when the pressure of the fluid on the secondary side increases, it is possible to suppress the valve body from being excessively pressed against the valve seat portion and to maintain the fluid sealing performance by the valve body.

  According to a third invention, in the second invention, the end on the operation chamber side integrated with the valve body and the press switching portion are relatively slidable in the displacement direction of the valve body. Since the sliding part fitted is provided, the end on the operation chamber side integrated with the valve body, while allowing relative displacement between the valve body and the pressure switching part in the displacement direction of the valve body, It is possible to suppress the relative movement of the pressing switching unit in the direction orthogonal to the displacement direction of the valve body. Here, the press switching part is connected to the intermediate restricting part, and the intermediate restricting part provided closer to the outer peripheral edge than the central part of the diaphragm is smaller in displacement than the central part. For this reason, it can suppress that the edge part by the side of the operation chamber integrated with the valve body shifts | deviates to the direction orthogonal to the displacement direction of a valve body, and can stabilize the attitude | position of a valve body. As a result, it is possible to suppress a decrease in the accuracy with which the fluid control valve controls the fluid pressure.

  According to a fourth invention, in any one of the first to third inventions, when the intermediate portion of the flexible portion is displaced from the flow path side to the operation chamber side to the restriction position in the operation chamber. An abutting portion that abuts against the intermediate restricting portion and restricts the intermediate portion from being displaced from the restricting position is provided.

  According to the fourth invention, when the intermediate restricting portion is displaced integrally with the intermediate portion of the flexible portion, the intermediate restricting portion abuts on the abutting portion provided in the operation chamber, whereby the flexible portion Displacement of the middle part of the is regulated at the regulation position. Therefore, the displacement of the intermediate portion of the flexible portion can be restricted with a simple configuration.

  According to a fifth invention, in any one of the first to fourth inventions, the intermediate restricting portion is arranged in an annular shape at an intermediate portion between the outer peripheral edge and the inner peripheral edge of the flexible portion. The pressure applied to the flexible portion can be received over the entire circumference of the intermediate restricting portion. As a result, the pressure acting on the flexible portion from the intermediate restricting portion can be reduced, so that the flexible portion of the diaphragm can be prevented from being damaged.

  According to a sixth aspect of the invention, in any one of the first to fifth aspects of the invention, in the projection plane perpendicular to the displacement direction of the valve body, the area on the inner circumferential side of the intermediate portion of the flexible portion is the valve Since it is set larger than the area on the inner peripheral side than the contact part between the seat part and the valve body, when the pressure of the fluid on the secondary side rises, the force corresponding to the difference between these areas is Acts as a force to seat the body on the valve seat. As a result, even when the intermediate portion of the flexible portion is restricted from being displaced from the flow path side to the operation chamber side, the fluid sealing performance by the valve body can be appropriately maintained.

Sectional drawing which shows a pilot regulator. Sectional drawing which shows operation | movement of the pilot regulator of FIG. Sectional drawing which shows the modification of a pilot regulator. Sectional drawing which shows operation | movement of the pilot regulator of FIG. Sectional drawing which shows the modification of a regulator. Sectional drawing which shows the conventional pilot regulator. Sectional drawing which shows the other conventional pilot regulator.

  Hereinafter, an embodiment embodied in a pilot regulator for controlling the pressure of a chemical solution will be described with reference to the drawings.

  As shown in FIG. 1, the pilot regulator 20 (fluid control valve) includes a first cover 35 and a second cover 36, and an intermediate body 30 is assembled between the covers 35 and 36. The intermediate body 30 is formed with an inflow port 21 through which a chemical solution is introduced and an outflow port 22 through which the chemical solution is discharged. The intermediate body 30 in contact with the chemical solution is formed of, for example, a fluorine-based synthetic resin so as not to be corroded, and the covers 35 and 36 not in contact with the chemical solution are formed of, for example, a polypropylene resin. The first cover 35, the second cover 36, and the intermediate body 30 constitute a valve body.

  A through hole serving as a valve chamber 23 that communicates the inflow port 21 and the outflow port 22 is formed in a substantially central portion of the intermediate body 30 so as to extend in the assembly direction of the first cover 35 and the second cover 36. . The valve chamber 23 has a small hole diameter in the middle of the assembly direction. In other words, the inner wall surface of the valve chamber 23 protrudes inward in the middle, and the valve seat portion 25 is formed by this protruding portion. The valve chamber 23 has an upstream valve chamber 23a on the upstream side (primary side) with respect to the valve seat portion 25 in the flow direction of the chemical solution, and a downstream side (secondary side) with respect to the valve seat portion 25 on the downstream side. It is a side valve chamber 23b. The upstream valve chamber 23a is connected to the inflow port 21 by an inflow passage 21a. In addition, a circular passage 23c having a larger hole diameter is formed downstream of the downstream valve chamber 23b. The circular passage 23c is connected to the outflow port 22 by the outflow passage 22a. The inflow passage 21a, the upstream valve chamber 23a, the downstream valve chamber 23b, the circular passage 23c, and the outflow passage 22a constitute a flow path.

  The valve chamber 23 accommodates a cylindrical valve body 24 that can reciprocate in the assembly direction of the first cover 35 and the second cover 36. Two diaphragms 27 and 29 are connected to the valve body 24, and the valve body 24 and the diaphragm 29 are integrally formed. The valve body 24 and the central portion 27 a of the diaphragm 27 are fastened, and the valve body 24 is integrated with the central portion 27 a of the diaphragm 27. The fixed portion 27 d of the diaphragm 27 is fixed by being sandwiched between the first cover 35 and the intermediate body 30. In the diaphragm 27, a portion between the central portion 27a and the fixed portion 27d is a flexible portion 27g that bends according to pressure. The valve body 24 and the diaphragms 27 and 29 that are in contact with the chemical solution are formed of, for example, a fluorine-based synthetic resin so as not to be corroded.

  The valve body 24 is formed with an enlarged diameter portion 28 having a diameter larger than that of other portions in the middle of the axial direction. An end portion of the enlarged diameter portion 28 facing the valve seat portion 25 is formed to be larger than the inner diameter of the valve seat portion 25 and can come into contact with the valve seat portion 25. Therefore, when the valve body 24 moves in the direction of the diaphragm 27, the end of the enlarged diameter portion 28 comes into contact with the valve seat portion 25, and communication between the inflow port 21 and the outflow port 22 is blocked. When the pressure (secondary pressure) of the chemical solution in the circular passage 23c increases, the pressure applied to the diaphragm 27 increases, so that the force with which the end portion of the enlarged diameter portion 28 comes into contact with the valve seat portion 25 is increased. growing. On the other hand, when the valve body 24 moves in the direction of the diaphragm 29, the end portion of the enlarged diameter portion 28 is separated from the valve seat portion 25, and the inlet 21 and the outlet 22 are communicated.

  A spring accommodating chamber 31 is formed on the second cover 36 on the opposite side of the valve chamber 23 with the diaphragm 29 interposed therebetween. A compression coil spring 32 is accommodated in the spring accommodating chamber 31. Due to the urging force of the compression coil spring 32, the valve body 24 is constantly urged toward the diaphragm 27 side. As a result, the state in which the end portion of the enlarged diameter portion 28 formed in the valve body 24 abuts on the valve seat portion 25 is maintained.

  An operation chamber 33 into which air from the outside of the pilot regulator 20 is introduced is formed on the opposite side of the valve chamber 23 across the diaphragm 27. That is, the diaphragm 27 divides the inside of the valve main body into a chemical flow path and an operation chamber 33 into which air is introduced. The operation chamber 33 is formed with a shaping portion 33b for suppressing the bulging direction of the diaphragm 27 from being reversed when the diaphragm 27 is displaced toward the operation chamber 33 side. Specifically, the shaping portion 33b has a curved portion 33d that curves in the same direction as the expansion direction of the diaphragm 27 (the convex direction toward the valve chamber 23), and the curved portion 33d is formed in an annular shape. For this reason, when the diaphragm 27 contacts the curved portion 33d of the shaping portion 33b, the diaphragm 27 can be shaped along the curved portion 33, and the bulge direction of the diaphragm 27 is opposite (convex direction toward the operation chamber 33). Can be suppressed. The operation chamber 33 communicates with an introduction port 34 formed in the first cover 35. Air is introduced into the introduction port 34 through the air passage. The position of the valve body 24 is adjusted by controlling the air pressure (operation pressure) in the operation chamber 33.

  Here, in the present embodiment, as described below, the end of the diameter-expanded portion 28 of the valve body 24 is prevented from being excessively pressed against the valve seat portion 25, and the sealing performance of the chemical solution by the valve body 24 is suppressed. The structure for hold | maintaining is provided.

  On the surface of the diaphragm 27 on the operation chamber 33 side, the outer peripheral edge (boundary between the flexible part 27g and the fixed part 27d) and the inner peripheral edge (boundary between the flexible part 27g and the central part 27a) of the flexible part 27g of the diaphragm 27. The intermediate restricting portion 27b is provided in the intermediate portion 27m with the above. The intermediate restricting portion 27b is formed integrally with the diaphragm 27, and is formed in an annular shape at the approximate center of the flexible portion 27g in the radial direction of the diaphragm 27. For this reason, the intermediate restricting portion 27b is connected to the flexible portion 27g over the entire circumference, and when the flexible portion 27g is displaced, the intermediate portion 27m of the flexible portion 27g (the intermediate restricting portion 27b in the flexible portion 27g is provided). The unit is displaced with the part).

  The diameter of the annular intermediate restricting portion 27 b is set to be larger than the diameter of the annular contact portion between the valve body 24 and the valve seat portion 25. That is, on the projection plane perpendicular to the displacement direction of the valve body 24, the area on the inner peripheral side with respect to the intermediate portion 27 m of the flexible portion 27 g is on the inner peripheral side with respect to the contact portion between the valve seat portion 25 and the valve body 24. It is set larger than the area.

  Further, the intermediate portion 27m provided with the intermediate restricting portion 27b in the flexible portion 27g has a predetermined width in the radial direction of the diaphragm 27. The width of the intermediate portion 27m is set to a value that can prevent the flexible portion 27g from being damaged by the intermediate restricting portion 27b when a force acts between the flexible portion 27g and the intermediate restricting portion 27b. Has been. In other words, if the width of the intermediate portion 27m is too narrow, the flexible portion 27g may be damaged by the intermediate restricting portion 27b when a force acts between the flexible portion 27g and the intermediate restricting portion 27b. is there.

  The intermediate restricting portion 27 b has an annular shape and extends in a direction substantially perpendicular to the surface of the diaphragm 27. A ring-shaped ring member 40 (press switching unit) is disposed on the inner periphery of the intermediate restricting portion 27b. The outer peripheral surface of the ring member 40 is fixed to the inner peripheral surface of the intermediate restricting portion 27b. The intermediate restricting portion 27 b and the ring member 40 are fastened by a screw thread formed on the inner peripheral surface of the intermediate restricting portion 27 b and a screw thread formed on the outer peripheral surface of the ring member 40.

  In the state where the intermediate restricting portion 27b and the ring member 40 are fastened, the end surfaces of the intermediate restricting portion 27b and the ring member 40 opposite to the diaphragm 27 are both located on the same plane. For this reason, when the intermediate restricting portion 27b and the ring member 40 move in the direction of the wall surface 33a of the operation chamber 33, the end surface 40b of the intermediate restricting portion 27b and the ring member 40 becomes the wall surface 33a (contact portion) of the operation chamber 33. It will abut on the entire surface. Therefore, the intermediate restricting portion 27b and the ring member 40 can be stably brought into contact with the wall surface 33a of the operation chamber 33, and the intermediate restricting portion 27b and the ring member 40 are inclined or deformed in this contact state. Can be suppressed. In addition, you may shape | mold the intermediate | middle control part 27b and the ring member 40 integrally so that it may become a shape similar to the above.

  A through hole 40 a having a circular cross section is formed at the center of the ring member 40 so as to extend in the displacement direction of the valve body 24. A cylindrical convex portion 27 c extending in the displacement direction of the valve body 24 is formed at an end portion on the operation chamber 33 side in the central portion 27 a of the diaphragm 27, that is, an end portion on the operation chamber 33 side integrated with the valve body 24. Has been. These through holes 40a and the convex portions 27c are fitted in a state in which they can slide relative to each other in the displacement direction of the valve body 24. That is, in the displacement direction of the valve body 24, the end on the operation chamber 33 side integrated with the valve body 24 from the contact portion of the valve body 24 with the valve seat portion 25 (the operation chamber 33 in the central portion 27 a of the diaphragm 27. The total length of the ring member 40 and the length of the ring member 40 (the thickness in the displacement direction of the valve body 24) from the contact portion of the valve body 24 with the valve seat portion 25. It is set longer than the length to the wall surface 33a. In other words, in a state in which the valve body 24 is seated on the valve seat portion 25, the length in which the through hole 40a and the convex portion 27c are fitted in the displacement direction of the valve body 24 is a ring member in the displacement direction of the valve body 24. The length 40 is set to be longer than the length movable in the direction away from the center of the diaphragm 27. Therefore, the state in which the convex portion 27c of the central portion 27a of the diaphragm 27 and the through hole 40a of the ring member 40 are slidably fitted is maintained. Then, relative displacement between the valve body 24 and the ring member 40 in the displacement direction of the valve body 24 is allowed.

  Further, when the convex portion 27 c of the central portion 27 a of the diaphragm 27 and the through hole 40 a of the ring member 40 are fitted, the convex portion 27 c and the ring member 40 are relatively moved in a direction orthogonal to the displacement direction of the valve body 24. Is suppressed. Here, the ring member 40 is fastened to the intermediate restricting portion 27b, and the intermediate restricting portion 27b provided closer to the outer peripheral edge (the intermediate portion 27m of the flexible portion 27g) than the central portion 27a of the diaphragm 27 is the central portion 27a. The displacement becomes smaller than. For this reason, it can suppress that the convex part 27c shifts | deviates to the direction orthogonal to the displacement direction of the valve body 24, and can stabilize the attitude | position of the valve body 24. FIG. That is, when a force that tilts the central axis of the valve body 24 is applied, the ring member 40 can suppress the movement of the convex portion 27c.

  A gap is formed between the flexible portion 27 g of the diaphragm 27 and the ring member 40. A space 33 c is defined by the central portion 27 a of the diaphragm 27, the intermediate restriction portion 27 b, and the ring member 40. In a state where the central portion 27a of the diaphragm 27 and the ring member 40 are in contact with each other in the displacement direction of the valve body 24, it is difficult for air to flow into and out of the space 33c through the through hole 40a. On the other hand, a communication hole 40c that allows air to flow into and out of the space 33c is formed in the ring member 40. For this reason, when the volume of the space 33c changes, air can be smoothly flowed in and out through the communication hole 40c. A sliding portion is configured by the convex portion 27 c of the central portion 27 a of the diaphragm 27 and the through hole 40 a of the ring member 40.

  In a state where the valve body 24 is seated on the valve seat portion 25 and the central portion 27a of the diaphragm 27 and the ring member 40 are pressed against each other in the displacement direction of the valve body 24, the diaphragm 27 of the ring member 40 and the intermediate restriction portion 27b. A gap is formed between the end surface 40 b on the opposite side to the wall surface 33 a of the operation chamber 33. In this state, when the diaphragm 27, the intermediate regulating portion 27b, and the ring member 40 are displaced toward the operation chamber 33 due to the pressure (secondary pressure) of the chemical in the circular passage 23c, the operation chamber 33 is moved from the circular passage 23c side of the valve body 24 to the operation chamber 33. Since the displacement to the side is regulated by the valve seat portion 25, the ring member 40 is moved away from the central portion 27 a of the diaphragm 27 in the displacement direction of the valve body 24, that is, in the displacement direction of the valve body 24. The central portion 27a of the diaphragm 27 and the ring member 40 are not pressed against each other. Therefore, the diaphragm 27 is moved from the circular passage 23c side to the operation chamber 33 side by the pressure of the chemical solution in the circular passage 23c rather than the force that displaces the diaphragm 27 to the circular passage 23c side by the air pressure (operation pressure) in the operation chamber 33. When the displacement force increases, it is possible to prevent the force that displaces the diaphragm 27 from the circular passage 23 c side to the operation chamber 33 side from being transmitted to the valve body 24.

  When the intermediate restricting portion 27b and the ring member 40 are further displaced in the direction of the wall surface 33a of the operation chamber 33, the intermediate restricting portion 27b and the end surface 40b of the ring member 40 are brought into contact with the wall surface 33a and further displacement is restricted. . That is, the position of the intermediate restricting portion 27b when the intermediate restricting portion 27b and the end surface 40b of the ring member 40 contact the wall surface 33a is the restricting position. Therefore, the force acting on the outer peripheral side portion of the diaphragm 27 relative to the intermediate restricting portion 27 b can be received by the wall surface 33 a of the operation chamber 33 via the intermediate restricting portion 27 b and the ring member 40.

  The operation of the pilot regulator 20 configured as described above will be described with reference to FIGS.

  In an initial state where the operation pressure is not applied to the operation chamber 33 and the pressure (secondary pressure) of the chemical solution on the outlet 22 side is low, the end of the enlarged diameter portion 28 of the valve body 24 is urged by the urging force of the compression coil spring 32. The portion abuts on the valve seat portion 25, and the communication between the upstream valve chamber 23a and the downstream valve chamber 23b is blocked. Thereby, the distribution of the chemical solution from the inlet 21 to the outlet 22 is prevented. Further, the central portion 27a of the diaphragm 27 and the ring member 40 are slightly pressed with each other in the displacement direction of the valve body 24, or the forces pressing each other are substantially zero.

  In contrast, when air is introduced into the operation chamber 33, the ring member 40 presses the central portion 27 a of the diaphragm 27, and the valve body 24 connected to the central portion 27 a resists the urging force of the compression coil spring 32. To the diaphragm 29 side. For this reason, the upstream valve chamber 23a and the downstream valve chamber 23b communicate with each other, and the flow of the chemical solution from the inflow port 21 to the outflow port 22 is allowed. Further, the distance between the end portion of the enlarged diameter portion 28 and the valve seat portion 25 changes according to the operation pressure in the operation chamber 33. As a result, the flow rate of the chemical solution flowing from the upstream valve chamber 23a to the downstream valve chamber 23b increases or decreases, and the pressure of the chemical solution in the circular passage 23c is controlled.

  Here, in a state where the end portion of the enlarged diameter portion 28 of the valve body 24 is separated from the valve seat portion 25, the state in which the central portion 27a of the diaphragm 27 and the ring member 40 press each other in the displacement direction of the valve body 24 is maintained. Is done. That is, since the valve body 24 is always urged toward the diaphragm 27 by the urging force of the compression coil spring 32 accommodated in the spring accommodating chamber 31, the central portion 27a of the diaphragm 27 is intermediate between the flexible portion 27g. The intermediate restricting portion 27b connected to the portion 27m and the ring member 40 are pressed. For this reason, the valve body 24, the central portion 27a of the diaphragm 27, the ring member 40, and the intermediate restricting portion 27b are integrally displaced. In addition, the convex part 27c of the center part 27a of the diaphragm 27 and the through hole 40a of the ring member 40 are in a fitted state. For this reason, as above-mentioned, it can suppress that the convex part 27c shifts | deviates to the direction orthogonal to the displacement direction of the valve body 24, and can stabilize the attitude | position of the valve body 24. FIG.

  Further, in the flexible portion of the diaphragm, the area on the inner peripheral side with respect to the top of the bent portion is an effective pressure receiving area that generates a force for displacing the valve element. And the precision with which a fluid control valve controls a chemical | medical solution becomes high, so that this effective pressure receiving area is large.

  In the present embodiment, when the valve body 24 is separated from the valve seat portion 25, the central portion 27a of the diaphragm 27, the ring member 40, and the intermediate restricting portion 27b are integrally displaced. For this reason, in the flexible part 27g, the inner peripheral part 27f on the inner peripheral side of the intermediate part 27m does not function as a diaphragm, and in the flexible part 27g, the outer peripheral part 27e on the outer peripheral side of the intermediate part 27m functions as a diaphragm. Therefore, the effective pressure receiving area of the diaphragm 27 can be increased to the outer peripheral portion 27e on the outer peripheral side with respect to the intermediate portion 27m. Specifically, the area on the inner peripheral side with respect to the bending top of the outer peripheral part 27e is an effective pressure receiving area that generates a force for displacing the valve body 24, and is as effective as the conventional fluid control valve 820 shown in FIG. A pressure receiving area can be secured.

  In the state where the operation pressure is applied to the operation chamber 33, the end portion of the diameter-expanded portion 28 of the valve body 24 is adjusted by the balance between the force due to the operation pressure, the biasing force of the compression coil spring 32, and the force due to the secondary pressure. When it comes into contact with the seat 25, the communication between the upstream valve chamber 23a and the downstream valve chamber 23b is blocked. In this state, since the operation pressure is applied to the operation chamber 33, the central portion 27a of the diaphragm 27 and the ring member 40 in the displacement direction of the valve body 24 until the pressure of the chemical solution on the outlet 22 side increases to some extent. Are kept pressed against each other.

  Here, in the state where the valve body 24 is seated on the valve seat 25, when the pressure of the chemical solution on the outlet 22 side increases, the diaphragm 27 is displaced from the circular passage 23c side to the operation chamber 33 side as shown in FIG. The force is increased, and the ring member 40 is moved away from the central portion 27a of the diaphragm 27 in the displacement direction of the valve body 24. That is, the central portion 27a of the diaphragm 27 and the ring member 40 are not pressed against each other in the displacement direction of the valve body 24. At this time, the ring member 40 is guided in the direction perpendicular to the diaphragm 27 (the displacement direction of the valve body 24) by sliding in a state where the convex portion 27c of the central portion 27a and the ring member 40 are fitted. Accordingly, in the configuration in which the central portion 27a of the diaphragm 27 and the ring member 40 are connected, the pressure acting on the flexible portion 27g (the inner peripheral portion 27f, the intermediate portion 27m, and the outer peripheral portion 27e) is controlled via the ring member 40. While being transmitted to the body 24, it is possible to suppress this pressure from being transmitted to the valve body 24 via the ring member 40.

  Since the flexible portion 27g of the diaphragm 27 is in contact with the curved portion 33d of the shaping portion 33b and the diaphragm 27 is shaped along the curved portion 33, the expansion direction of the diaphragm 27 is opposite (convex direction toward the operation chamber 33). Can be suppressed. In a state where the flexible portion 27g of the diaphragm 27 is in contact with the curved portion 33d of the shaping portion 33b, the pressure applied to the outer peripheral portion 27e on the outer peripheral side from the intermediate portion 27m of the flexible portion 27g by the chemical solution in the circular passage 23c. Is transmitted to the valve body 24 by the shaping portion 33b.

  Further, when the volume of the space 33c defined by the diaphragm 27, the central portion 27a of the diaphragm 27, the intermediate restricting portion 27b, and the ring member 40 is increased, air flows in through the communication hole 40c. The part 27b can be moved smoothly.

  And if the end surface 40b of the ring member 40 and the intermediate | middle control part 27b contact | abuts to the wall surface 33a of the operation chamber 33, the displacement of the ring member 40 and the intermediate | middle control part 27b will be controlled. For this reason, the pressure acting on the outer peripheral portion 27 e in the flexible portion 27 g of the diaphragm 27 is received by the wall surface 33 a of the operation chamber 33 via the intermediate restricting portion 27 b and the ring member 40. Accordingly, the intermediate restricting portion 24b suppresses the pressure acting on the outer peripheral portion 27e from being transmitted to the valve body 24.

  At this time, the pressure acting on the inner peripheral portion 27f in the flexible portion 27g of the diaphragm 27 is transmitted to the central portion 27a of the diaphragm 27, and acts as a force for pulling the valve body 24 toward the operation chamber 33. That is, of the pressure acting on the entire flexible portion 27g, the pressure acting on the inner peripheral portion 27f acts as the pressure for seating the valve body 24 on the valve seat portion 25. For this reason, the end of the enlarged diameter portion 28 of the valve body 24 is appropriately pressed against the valve seat portion 25, and the sealing performance of the chemical solution by the valve body 24 can be maintained.

  Further, in the projection plane perpendicular to the displacement direction of the valve body 24, the area of the inner peripheral portion 27f on the inner peripheral side with respect to the intermediate portion 27m of the flexible portion 27g is the contact portion between the valve seat portion 25 and the valve body 24. It is set larger than the area on the inner peripheral side. For this reason, it acts on the inner peripheral portion 27f of the flexible portion 27g rather than the force that acts on the enlarged diameter portion 28 of the valve body 24 to separate the valve body 24 from the valve seat portion 25. The force to be seated on the valve seat portion 25 can be increased. Therefore, as compared with the conventional configuration in which the valve body and the diaphragm are separated, it is possible to leave a force for the diaphragm 27 to seat the valve body 24.

  When the ring member 40 and the intermediate restricting portion 27b move from the operation chamber 33 side to the circular passage 23c side and the volume of the space 33c is reduced, air flows out through the communication hole 40c. 27 can be quickly brought into contact with the central portion 27a. As a result, since the responsiveness at the time of moving the valve body 24 can be improved, the pressure of the chemical | medical solution by the side of the outflow port 22 can be raised rapidly.

  According to the configuration of the present embodiment described in detail above, the following excellent effects can be obtained.

  By displacing the diaphragm 27 and the valve body 24 based on the operation pressure applied to the diaphragm 27 from the operation chamber 33, the relative position between the valve seat portion 25 and the valve body 24 is adjusted, and the pressure of the secondary side chemical solution And the flow rate can be controlled. The intermediate restricting portion 27b is displaced integrally with the intermediate portion 27m between the outer peripheral edge and the inner peripheral edge of the flexible portion 27g of the diaphragm 27. In this state, the displacement of the intermediate portion 27m is not restricted, and the diaphragm The chemical solution on the secondary side can be controlled based on the operation pressure applied to the entire 27.

  When the pressure of the chemical solution on the secondary side rises, the flexible portion 27g of the diaphragm 27 is displaced from the circular passage 23c side to the operation chamber 33 side and is displaced in the direction in which the valve body 24 is seated on the valve seat portion 25. The force in the direction of seating on the valve seat 25 acting on the body 24 increases. When the valve body 24 is seated on the valve seat portion 25, the intermediate restriction portion 27b restricts the intermediate portion 27m of the flexible portion 27g from being displaced from the restriction position from the circular passage 23c side to the operation chamber 33 side. Is done. In a state in which the displacement of the intermediate portion 27m is restricted, the pressure applied to the outer peripheral portion 27e on the outer peripheral side of the flexible portion 27g with respect to the outer peripheral portion 27e of the flexible portion 27g is transmitted to the valve body 24 by the chemical solution in the circular passage 23c. The pressure that is suppressed by the intermediate restricting portion 27b and is applied to the inner peripheral portion 27f on the inner peripheral side of the intermediate portion 27m of the flexible portion 27g is transmitted to the valve body 24 via the central portion 27a by the inner peripheral portion 27f. The Here, the force by which the valve body 24 is pulled by the pressure applied to the inner peripheral portion 27f of the flexible portion 27g is applied to the entire flexible portion 27g (the inner peripheral portion 27f, the intermediate portion 27m, and the outer peripheral portion 27e). It becomes smaller than the force by which the valve body 24 is pulled by the pressure to be applied. As a result, in the state where the valve body 24 is seated on the valve seat portion 25, even when the pressure of the secondary side chemical liquid is increased, the valve body 24 is prevented from being excessively pressed against the valve seat portion 25. At the same time, the sealing performance of the chemical solution by the valve body 24 can be maintained.

  Since the ring member 40 is fastened to the intermediate restricting portion 27b and the valve body 24 is separated from the valve seat portion 25, the ring member 40 and the valve body 24 are pressed against each other in the displacement direction of the valve body 24. In the displacement direction of the body 24, the relative displacement between the intermediate portion 27m of the flexible portion 27g and the valve body 24 is limited. For this reason, in the flexible part 27g, the inner peripheral part 27f on the inner peripheral side of the intermediate part 27m does not function as a diaphragm, and in the flexible part 27g, the outer peripheral part 27e on the outer peripheral side of the intermediate part 27m functions as a diaphragm. Accordingly, the inner peripheral portion 27f existing on the inner peripheral side of the intermediate portion 27m is prevented from reducing the effective pressure receiving area, and the effective pressure receiving area of the diaphragm 27 is increased to the outer peripheral portion 27e on the outer peripheral side of the intermediate portion 27m. can do. As a result, it is possible to suppress a decrease in the accuracy with which the pilot regulator 20 controls the chemical solution.

  Further, since the ring member 40 and the valve body 24 are not pressed against each other in the displacement direction of the valve body 24 in a state where the valve body 24 is seated on the valve seat portion 25, the flexible portion 27g is caused by the chemical solution in the circular passage 23c. The pressure applied to the valve body is not transmitted to the valve body via the ring member 40. When the ring member 40 and the valve body 24 are not pressed against each other in the displacement direction of the valve body 24, relative displacement between the intermediate portion 27m of the flexible portion 27g and the valve body 24 in the displacement direction of the valve body 24 is allowed. be able to. When the width by which the intermediate portion 27m of the flexible portion 27g is displaced from the operation chamber 33 side to the circular passage 23c due to this relative displacement increases, as described above, the intermediate portion 27m of the flexible portion 27g is operated from the circular passage 23c side. Displacement from the restriction position toward the chamber 33 is restricted by the intermediate restriction part 27b.

  The operation chamber 33 end integrated with the valve body 24 (the operation chamber 33 end at the central portion 27a of the diaphragm 27) and the ring member 40 can slide relative to each other in the displacement direction of the valve body 24. Since the convex portion 27c and the through hole 40a that are fitted with each other are provided, the convex portion 27c and the ring are allowed to allow relative displacement between the valve body 24 and the ring member 40 in the displacement direction of the valve body 24. Relative movement of the member 40 in a direction orthogonal to the displacement direction of the valve body 24 can be suppressed. Here, the ring member 40 is fastened to the intermediate restriction portion 27b, and the displacement of the intermediate restriction portion 27b provided closer to the outer peripheral edge than the central portion 27a of the diaphragm 27 is smaller than that of the central portion 27a. For this reason, it can suppress that the convex part 27c shifts | deviates to the direction orthogonal to the displacement direction of the valve body 24, and can stabilize the attitude | position of the valve body 24. FIG. As a result, it is possible to suppress a decrease in accuracy with which the pilot regulator 20 controls the pressure of the chemical solution.

  When the intermediate restricting portion 27b is displaced integrally with the intermediate portion 27m of the flexible portion 27g, the intermediate restricting portion 27b comes into contact with the wall surface 33a provided in the operation chamber 33, whereby the intermediate portion of the flexible portion 27g. A 27-m displacement is regulated at the regulation position. Therefore, the displacement of the intermediate portion 27m of the flexible portion 27g can be restricted with a simple configuration.

  Since the intermediate restricting portion 27b is arranged in an annular shape at an intermediate portion 27m between the outer peripheral edge and the inner peripheral edge of the flexible portion 27g, the pressure applied to the flexible portion 27g of the diaphragm 27 is applied to all of the intermediate restricting portion 27b. It can be received over the lap. As a result, the pressure acting on the flexible portion 27g from the intermediate restricting portion 27b can be reduced, so that the flexible portion 27g of the diaphragm 27 can be prevented from being damaged.

  On the projection plane perpendicular to the displacement direction of the valve body 24, the area of the inner peripheral portion 27f on the inner peripheral side of the intermediate portion 27m of the flexible portion 27g is larger than the contact portion between the valve seat portion 25 and the valve body 24. Since it is set to be larger than the area on the inner peripheral side, when the pressure of the chemical solution on the secondary side rises, a force corresponding to the difference between these areas acts as a force for seating the valve body 24 on the valve seat portion 25. To do. As a result, even when the intermediate portion 27m of the flexible portion 27g is restricted from being displaced from the circular passage 23c side to the operation chamber 33 side, the sealing performance of the chemical solution by the valve body 24 can be appropriately maintained. it can.

  It is not limited to the said embodiment, For example, it can also implement as follows.

  In the above embodiment, the central portion 27a of the diaphragm 27 is in contact with the ring member 40. However, the valve body 24 contacts the ring member 40 by causing the valve body 24 to protrude further toward the operation chamber 33 than the diaphragm 27. It can also be touched. With such a configuration, the valve body 24 and the ring member 40 may be pressed against each other in the displacement direction of the valve body 24.

  In the above embodiment, the intermediate restricting portion 27b is arranged in an annular shape in the intermediate portion 27m of the flexible portion 27g. However, a part of the annular intermediate restricting portion 27b can be omitted. Even in such a configuration, when the pressure of the chemical liquid in the circular passage 23c rises with the valve body 24 seated on the valve seat portion 25, the diaphragm 27 operates the valve body 24 from the circular passage 23c side. The force pulled toward the chamber 33 can be reduced.

  In the above embodiment, the convex portion 27c is formed at the end portion on the operation chamber 33 side in the central portion 27a of the diaphragm 27 and the through hole 40a is formed in the ring member 40, but the operation chamber 33 side in the central portion 27a of the diaphragm 27 is formed. While forming a recessed part in the edge part of this, and forming a convex part in the center part of the ring member 40, these may be slidably fitted. Further, these convex portions, through holes, and concave portions may be omitted, and the end portion on the operation chamber 33 side in the central portion 27a of the diaphragm 27 and the ring member 40 may be in contact with each other on a plane.

  In the above embodiment, the operation pressure is directly applied to the diaphragm 27 that contacts the chemical solution. However, as shown in FIGS. 3 and 4, the operation pressure is applied to the diaphragm 129 and the diaphragm 129 and the disk member. The valve body 24 may be pressed via 140. Also in this case, an intermediate restricting portion 127b is formed, and a convex portion that is fitted to the central portion 127a of the diaphragm 127 and the disc member 140 in a state in which the valve member 24 can be relatively slid in the displacement direction. 127c and a recess 140a are provided. The intermediate restricting portion 127b and the disk member 140 are formed separately and are in contact with each other.

  Further, a flange 140b is formed on the outer periphery of the disk member 140, and an inner wall surface of the operation chamber 133 protrudes inward to form a protruding portion 133a that faces the flange 140b. In a state where the valve body 24 is seated on the valve seat portion 25, in a state where the central portion 127 a of the diaphragm 127 and the disk member 140 are pressed against each other in the displacement direction of the valve body 24, the flange 140 b of the disk member 140 and the operation chamber A gap is formed between the protruding portion 133a of 133.

  And when the pressure of the chemical | medical solution by the side of the outflow port 22 rises in the state which the valve body 24 seated to the valve seat part 25, as shown in FIG. 4, the force which displaces the diaphragm 127 from the circular channel | path 23c side to the operation chamber 133 side. And the central portion 127a of the diaphragm 127 and the disc member 140 are not pressed against each other in the displacement direction of the valve body 24. When the flange 140b of the disc member 140 abuts on the protruding portion 133a of the operation chamber 133, the displacement of the disc member 140 and the intermediate restricting portion 127b is restricted. Even if it is such a structure, there can exist an effect similar to the said embodiment.

  In the above embodiment, the pressure of the chemical liquid is controlled by controlling the pressure of the air introduced into the operation chamber 33. However, as shown in FIG. 5, the pressure applied to the disk member 240 is manually adjusted. You may adjust. In this case, the spring 232 is in contact with the disc member 240, and the pressure applied to the disc member 240 via the spring retainer 237 and the spring 232 is adjusted by turning the handle 238. Further, ribs 240b extend from the outer peripheral edge of the disk member 240 in a direction perpendicular to the surface of the disk, and the step portion 233a is ribbed at the portion where the hole diameter changes in the operation chamber 233 formed as a cylindrical space. It is formed opposite to 240b. In a state in which the valve body 24 is seated on the valve seat portion 25, the rib 240 b of the disk member 240 and the operation chamber are in a state in which the central portion 127 a of the diaphragm 127 and the disk member 240 are pressed against each other in the displacement direction of the valve body 24. A gap is formed between the step portion 233a of 233. Even if it is such a structure, there can exist an effect similar to the said embodiment. Moreover, it can also be set as the structure which controls the pressure applied to the disc member 240 with an electromagnetic actuator.

  20 ... Pilot regulator as a fluid control valve, 23c ... Circular passage, 24 ... Valve body, 25 ... Valve seat part, 27 ... Diaphragm, 27b ... Intermediate regulating part, 27g ... Flexible part, 27m ... Intermediate part, 33 ... Operation Room.

Claims (6)

A valve body having a fluid flow path therein and a valve seat portion provided in the middle of the flow path; a diaphragm partitioning the inside of the valve body into the flow path and the operation chamber; and A valve body that is integrated on the inner peripheral side with respect to the flexible portion and that is displaced from a state of being seated on the valve seat portion to a state of being separated from the valve seat portion, and when the pressure of the fluid on the secondary side rises, The flexible portion is displaced from the flow path side to the operation chamber side and the valve body is displaced in a direction in which the valve body is seated on the valve seat portion, and the diaphragm is based on the pressure applied to the diaphragm from the operation chamber. And a fluid control valve that controls the fluid on the secondary side by displacing the valve body,
The diaphragm is integrally displaced with an intermediate portion between an outer peripheral edge and an inner peripheral edge of the flexible portion, and the intermediate portion of the flexible portion is in the state where the valve body is seated on the valve seat portion. A fluid control valve comprising an intermediate restricting portion for restricting displacement from a restricting position from the road side to the operation chamber side.   The valve body is connected to the intermediate regulating portion, and in a state where the valve body is separated from the valve seat portion, the valve body is pressed against the valve body in the displacement direction of the valve body, while the valve body is seated on the valve seat portion. 2. The fluid control valve according to claim 1, further comprising: a pressure switching unit that is in a state in which the valve body is not pressed against each other in the displacement direction of the valve body in a state of being performed.   The operation chamber side end integrated with the valve body and the pressing switching portion are provided with a sliding portion that is fitted in a slidable state in the displacement direction of the valve body. The fluid control valve according to claim 2, wherein:   In the operation chamber, when the intermediate portion of the flexible portion is displaced from the flow path side to the operation chamber side to the restriction position, the intermediate portion comes into contact with the intermediate restriction portion and is displaced from the restriction position. The fluid control valve according to claim 1, further comprising a contact portion that restricts the operation.   The fluid control valve according to any one of claims 1 to 4, wherein the intermediate restricting portion is arranged in an annular shape at an intermediate portion between an outer peripheral edge and an inner peripheral edge of the flexible portion.   On the projection plane perpendicular to the displacement direction of the valve body, the area on the inner peripheral side with respect to the intermediate part of the flexible portion is the area on the inner peripheral side with respect to the contact part between the valve seat part and the valve body. The fluid control valve according to any one of claims 1 to 5, wherein the fluid control valve is set to be larger.

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