JP5918188B2 - Control valve - Google Patents

Description

  The present invention relates to a control valve having a piston member.

  A switching valve as a control valve used in an air conditioner or the like includes, for example, a pilot electromagnetic valve mechanism in a valve body having a valve seat on the periphery of the opening end of the chamber, as shown in Patent Document 1. The chamber communicates with the first passage and the second passage. The pilot solenoid valve mechanism includes a plunger that is slidably disposed in the plunger tube, a needle that is disposed on the inner peripheral portion of the lower end portion of the plunger, and a valve in which the tip of the needle is in contact with one end. It comprises a valve body that has a seat and selectively contacts the valve seat at the periphery of the opening end of the chamber by a needle, and an electromagnetic coil that is arranged around the outer periphery of the plunger tube. ing.

  As shown in FIGS. 5 (A) and 5 (B) in Patent Document 1, the valve body has a packing at the lower end that contacts the valve seat at the periphery of the opening end of the chamber and seals the opening end. Proposed. The packing as such a sealing member is held at the lower end of the valve body by both ends of the metal piece. Moreover, the valve body outer edge part in the both ends of the metal piece is comprised so that the step part of the valve seat in the opening edge periphery of a chamber may contact | abut.

  In such a configuration, when the electromagnetic coil is excited, the plunger and the needle are pushed down, and the lower end of the needle is lowered while abutting against the valve seat of the valve body. Abutting on the valve seat at the end periphery, the space between the first passage and the second passage is closed. On the other hand, when the electromagnetic coil is not excited, the packing of the valve body is separated from the valve seat at the periphery of the opening end of the chamber, so that the first passage and the second passage are opened.

JP 2001-124440 A JP 2001-330167 A JP-A-2001-263527

  When the packing is held by both ends of the metal piece in close contact with the lower end portion of the valve body, as in the valve body shown in Patent Document 1 above, when the valve body takes the above-mentioned closed state, After the packing contacts and is pressed against the valve seat, the outer edge of the valve body at both ends of the metal piece contacts the stepped portion of the valve seat at the periphery of the opening end of the chamber.

  However, since the packing is held by both ends of the metal piece in close contact with the lower end portion of the valve body and there is no fluid vent passage (gas vent hole) in the gap between the packing and the lower end portion of the valve body, As suggested in paragraph [0008], there is a risk that pressure builds up in the gap between the packing and the lower end of the valve body, so-called liquid sealing. Therefore, the packing may come off from the lower end of the valve body due to the liquid seal.

  In view of the above problems, an object of the present invention is to provide a control valve having a piston member, which can avoid pressure accumulation in a seal member held by the piston member with a simple configuration. And

  In order to achieve the above object, a control valve according to the present invention has an inlet port connected to a first passage and an outlet port connected to a second passage. A valve body portion having a housing portion that communicates and movably accommodates a piston unit that controls opening and closing of the outlet port; and a piston unit drive mechanism that causes the piston unit to perform an operation of opening and closing the outlet port. A seal member that selectively contacts a valve seat formed on the periphery of the outlet port; and a holding ring member that is engaged with the seal member and holds the seal member. And a holding ring member having a groove communicating with the gap formed around the groove and a passage continuing to the groove at an end contacting the seal member.

  According to the control valve of the present invention, the piston unit is a holding ring member that is engaged with the seal member and holds the seal member, and communicates with a gap formed around the accommodating portion of the valve main body and the seal member. And a holding ring member having a groove connected to the groove at an end contacting the seal member, pressure accumulated in a gap formed around the seal member is applied to the groove and the groove. Since it is avoided through the continuous passage, it is possible to avoid the accumulation of pressure in the seal member held by the piston member with a simple configuration.

It is a perspective view which shows the external appearance of the piston unit used for an example of the control valve which concerns on this invention. It is sectional drawing which shows the structure of an example of the control valve which concerns on this invention with the pipe for piping. It is a fragmentary sectional view which expands and shows the principal part in the example shown by FIG. It is a disassembled perspective view in the example shown by FIG. It is the elements on larger scale which expand and show the V section shown by FIG. FIG. 3 is a partially enlarged view for explaining the operation of the holding ring member in the example shown in FIG. 2. (A), (B), and (C) are perspective views which respectively show an example of the holding | maintenance ring member used for the piston unit shown by FIG. It is sectional drawing which shows the structure of the other example of the control valve which concerns on this invention with the pipe for piping.

  FIG. 2 schematically shows a configuration of an example of a control valve according to the present invention together with a pipe for piping.

  In FIG. 2, the control valve is, for example, a normally closed electromagnetic valve, and is arranged in a pipe in a refrigerant circuit in the air conditioner. The solenoid valve includes a plunger 28 having a ball valve 34 movably disposed in the plunger tube 26, a piston unit having a discharge passage 36 b opened and closed by the ball valve 34 of the plunger 28 inside, and a plunger tube 26. The main part includes a valve main body 10 coupled to one end and an electromagnetic coil unit which is arranged on the outer peripheral portion of the plunger tube 26 and selectively excites the plunger 28 as main elements.

  The electromagnetic coil unit mainly includes a coil portion 20 disposed on the outer peripheral portion of the plunger tube 26, an attractor 24 that closes one end of the plunger tube 26, and a casing 16 that covers the coil portion 20 and is housed inside. It is configured. The coil unit 20 is electrically connected to a drive control unit (not shown) via a lead wire 22. The casing 16 is fixed to the suction element 24 by screwing the machine screw 18 into the female screw hole of the suction element 24 through the mounting hole of the casing 16. When the attractor 24 is excited by the coil portion 20, a plunger 28 described later is attracted to the attractor 24 by a magnetic force.

  As shown in FIG. 2, the plunger 28 is movably disposed between the end of the suction element 24 in the plunger tube 26 and a piston member 36 described later. The plunger 28 has a communication path 28a inside. One end of the coil spring 30 is received and accommodated in the enlarged portion of one end of the communication passage 28a facing the end of the suction element 24. The coil spring 30 biases the plunger 28 in a direction separating the plunger 28 from the attracting element 24, that is, toward the piston unit. One end of the coil spring 38 is received and accommodated in the enlarged portion at the other end of the communication passage 28a as shown in an enlarged manner in FIG. The coil spring 38 urges the ball valve 34 toward the open end of the ball cap 28 </ b> A that holds the ball valve 34. The ball cap 28 </ b> A is joined to the end of the plunger 28. The open end of the ball cap 28A is formed to face the other end of the communication path 28a. The diameter of the open end of the ball cap 28 </ b> A is set smaller than the diameter of the ball valve 34. The ball cap 28A has a plurality of pores so as to be substantially orthogonal to the central axis of the opening end. As a result, the other end of the communication passage 28a communicates with a gap between the outer peripheral portion of the ball cap 28A and the inner peripheral portion of a hole 36A of the piston member 36, which will be described later, via a plurality of pores.

  The valve body 10 is made of a metal material, for example, brass, stainless steel, aluminum alloy, and the like, and has a piston unit housing portion 10A that houses the piston unit together with the ball cap 28A. The piston unit housing portion 10A has an inlet port 10PI to which one end of the high-pressure side piping pipe 12 serving as a first passage is connected on an axis substantially orthogonal to the central axis of the plunger 28, and the central axis of the plunger 28 An outlet port 10PE to which one end of a low-pressure side pipe 14 as a second passage is connected is formed on a common axis.

  An annular valve seat 10V is formed at the opening end of the outlet port 10PE in the inner peripheral portion of the piston unit housing portion 10A. A valve body 42 as a seal member, which will be described later, is selectively brought into contact with the arcuate tip of the valve seat 10V. A flat stopper portion 10S is formed around the periphery of the valve seat 10V as shown in FIG. The stopper portion 10S is formed on a common plane with the base end of the valve seat 10V. Thereby, when the piston member 36 is pushed down, as shown by a two-dot chain line in FIG. 6, a lower end of the piston member 36 pushed down is brought into contact with the stopper portion 10S by a holding ring member 44 described later. Is positioned at a predetermined position.

  A retaining ring 32 is provided adjacent to one end of the plunger tube 26 on the inner side of the coupling end portion of the valve main body 10 where one end of the plunger tube 26 is coupled. As a result, one end of the piston member 36 comes into contact with the retaining ring 32, so that the position of the piston member 36 separated from the valve seat 10V is regulated. A coil spring 40 that urges the piston member 36 in a direction away from the valve seat 10 </ b> V is disposed between the outer peripheral portion of the piston member 36 and the step portion in the inner peripheral portion of the valve main body portion 10.

  Therefore, the drive mechanism of the piston unit, which will be described later, includes an electromagnetic coil unit, a plunger 28 including a ball valve 34, and a coil spring 40.

  As shown in FIG. 4, the piston unit is held by a piston member 36 movably disposed in the piston unit housing portion 10 </ b> A in the valve main body 10 described above, and a first recess 36 </ b> C of the piston member 36. A valve body 42 as a seal member and a holding ring member 44 that is locked to the valve body 42 and holds the valve body 42 in the first recess 36C of the piston member 36 are configured.

  The piston member 36 is made of a metal material, for example, brass, stainless steel, aluminum alloy, and has a hole 36A into which the ball cap 28A and the ball valve 34 are inserted, as shown in FIG. ing. At the bottom of the hole 36A, when the ball valve 34 is open, one end of a discharge passage 36b that discharges the high-pressure fluid in the hole 36A to the outlet port 10PE is opened. A valve seat for receiving the ball valve 34 is formed at one end of the discharge passage 36b. FIG. 3 shows a closed state of the ball valve 34.

  The other end of the discharge passage 36b opens toward the outlet port 10PE. The discharge passage 36b is formed so as to be disposed on an axis common to the central axis of the plunger 28 described above. An annular protrusion 36B for positioning the valve body 42 is formed on the periphery of the other end of the discharge passage 36b. An annular first recess 36C into which the valve body 42 is inserted is formed around the protrusion 36B. As shown in an enlarged view in FIG. 5, the height H from the inner peripheral surface forming the first recess 36 </ b> C substantially orthogonal to the central axis of the piston member 36 to the tip of the protrusion 36 </ b> B along the central axis. Is set to be slightly larger than the thickness T of the valve body 42 described later. At that time, the maximum diameter Dc of the inner peripheral portion of the first recess 36 </ b> C is set slightly larger than the maximum diameter of the valve body 42 with a predetermined gap. The maximum diameter Dc is set to be smaller than the diameter Db around the central axis of the valve body 10 at the falling part of the stopper 10S of the valve body 10. As a result, the pressing force of the piston member 36 is received by the stopper portion 10S of the valve body portion 10 via the holding ring member 44 without applying a bending moment to the holding ring member 44, and will be described later. The caulking portion 36E is not damaged, and an increase in creep of the valve body 42 is avoided.

  Further, as shown in FIG. 5, an annular second recess 36D having a diameter larger than the maximum diameter Dc of the inner periphery of the first recess 36C is formed on the periphery of the first recess 36C. ing. A holding ring member 44 described later is inserted into the second recess 36D. The depth Hb along the central axis of the piston member 36 in the second recess 36D is set to be substantially the same as or smaller than the thickness of the holding ring member 44 and smaller than the depth Ha of the first recess 36C. Has been. The depth Hb is not limited to such an example, and may be the same dimension as the depth Ha or may be large.

  The holding ring member 44 is locked by a caulking portion 36E formed at the tip of the piston member 36 and is held by the second recess 36D. The caulking portion 36E is formed over the entire circumference. The caulking portion 36E is formed by pressing after the valve body 42 and the holding ring member 44 are sequentially attached to the first recess 36C and the second recess 36D, as shown in an enlarged view in FIG. It is formed with a predetermined caulking allowance. At that time, a part of the caulking portion 36E is pushed into each groove 44G of the holding ring member 44 described later.

  The diameter Da around the central axis of the piston member 36 at the tip of the caulking portion 36E is set to be larger than the above-described diameter Db. Thereby, as shown in FIG. 3, when the piston unit closes the outlet port 10PE, there is no possibility that the tip of the caulking portion 36E interferes with the falling portion of the stopper portion 10S of the valve main body portion 10. The caulking portion 36E is not limited to such an example, and may be individually formed at a plurality of locations separated along the circumferential direction, for example.

  The valve body 42 as a sealing member is formed in an annular shape as shown in an enlarged view in FIG. 4 with a resin material, for example, an engineering plastic or a rubber material as an elastic material. The valve body 42 has a circular through hole 42a into which the protrusion 36B of the piston member 36 is inserted. The valve body 42 includes a large-diameter portion 42A that abuts on the inner peripheral surface that forms the first recess 36C, and a small-diameter portion 42B that is integrally formed with the large-diameter portion 42A and abuts on the valve seat 10V. Yes.

  The small diameter portion 42B selectively abuts on the valve seat 10V and seals the open end of the outlet port 10PE. A stepped portion 42S that is received by the annular surface of the holding ring member 44 is formed at the boundary portion between the small diameter portion 42B and the large diameter portion 42A as shown in an enlarged manner in FIGS.

  The holding ring member 44 is made of a metal material, for example, brass, stainless steel, aluminum alloy, or ceramic, in an annular shape. The material of the holding ring member 44 is not limited to such an example. For example, when the retaining ring member 44 is locked by a caulking portion 36E formed in the tapered portion of the piston member 36, the holding ring member 44 has a strength not to be damaged and a working fluid. Any material having corrosion resistance can be used.

  The holding ring member 44 has a through hole 44a into which the small-diameter portion 42B of the valve body 42 is inserted, as shown in an enlarged view in FIG. The holding ring member 44 has annular surfaces on both end surfaces in the thickness direction. Grooves 44G that cross the annular surface along the radial direction are formed facing the four locations at intervals of 90 ° along the circumferential direction of each annular surface. Further, an arc-shaped chamfer 44 </ b> C serving as a notch is provided at a position corresponding to the groove 44 </ b> G on the outer peripheral portion of the holding ring member 44. The shape of the chamfer 44C is not limited to such an example, and may be a flat shape, a rectangular shape, or a V shape, for example. Accordingly, as shown in FIGS. 5 and 6, when the holding ring member 44 holds the valve body 42, a part of the small diameter portion 42B of the valve body 42 is pushed into a part of each groove 44G, The gap between the outer periphery of the valve body 42 and the inner periphery of the first recess 36C communicates with the other part of the groove 44G. As a result, as indicated by arrows in FIG. 5, the working fluid or gas in the gap between the outer peripheral portion of the valve body 42 and the inner peripheral portion of the first recess 36C causes the groove 44G, the chamfer 44C, and the second It will discharge | release through between the inner peripheral parts of this recessed part 36D. As a result, so-called liquid sealing is avoided. Further, as shown in FIG. 5, a part of the small diameter portion 42B of the valve body 42 is pushed into a part of each groove 44G, so that the valve body 42 is prevented from loosening. Furthermore, as shown by a two-dot chain line in FIG. 6, when the annular surface of the holding ring member 44 abuts against the stopper portion 10S, creep due to excessive deformation of the valve body 42 is prevented. At that time, sticking of the annular surface of the holding ring member 44 to the stopper portion 10S is also avoided by the grooves 44G.

  In such a configuration, when the attractor 24 and the plunger 28 are not excited by the coil portion 20, the valve element 42 comes into contact with the valve seat 10V as shown in FIG. Is cut off. On the other hand, when the attractor 24 and the plunger 28 are excited by the coil part 20, the plunger 28 is separated from the piston member 36, whereby the ball valve 34 opens the discharge passage 36b, and the piston unit accommodating part 10A High pressure fluid is discharged to the outlet port 10PE. As a result, the pressure in the piston unit housing portion 10 </ b> A decreases, so that the valve body 42 of the piston member 36 is separated from the valve seat 10 </ b> V by the biasing force of the coil spring 40. At that time, the working fluid is supplied into the piston unit housing portion 10A. Therefore, the working fluid from the high-pressure side piping pipe 12 is supplied to the low-pressure side piping pipe 14 along the direction indicated by the arrow F in FIG. Thereafter, when the attractor 24 and the plunger 28 are not excited, the ball valve 34 in the plunger 28 comes into contact with the opening end of the discharge passage 36b by the urging force of the coil spring 30, so that the valve body 42 comes into contact with the valve seat 10V. The working fluid from the high-pressure side piping pipe 12 is shut off.

  The holding ring member 44 is not limited to such an example. For example, as shown in an enlarged view in FIG. 7B, the holding ring member 54 having the grooves 54GA and 54GB may be formed. The holding ring member 44 shown in FIG. 7A has a groove 44G formed to face each other. In the example shown in FIG. 7B, the holding ring member 44 is formed on one annular surface. The groove 54GA and the groove 54GB formed on the other annular surface do not face each other, and are formed at a deviated position with a predetermined circumferential angle. Thereby, since the thickness of the position corresponding to the grooves 54GA and 54GB in the holding ring member 54 can be increased as compared with the example shown in FIG. 7A, the bending rigidity of the holding ring member 54 is increased.

  The retaining ring member 54 is made of a metal material, for example, brass, stainless steel, aluminum alloy, or ceramic, in an annular shape. The holding ring member 54 has a through-hole 54a into which the small diameter portion 42B of the valve body 42 is inserted at the center. The holding ring members 54 have annular surfaces on both end surfaces in the thickness direction. Grooves 54GA and 54GB crossing each annular surface along the radial direction are formed at three positions at intervals of 120 ° along the circumferential direction of each annular surface. Further, at positions corresponding to the grooves 54GA and 54GB on the outer peripheral portion of the holding ring member 54, chamfers 54C forming a flat surface are provided at three locations.

  Further, the holding ring member is not limited to the example shown in FIGS. 7A and 7B, and is, for example, a holding ring member 64 as shown enlarged in FIG. 7C. May be.

  The retaining ring member 64 is made of a metal material, for example, brass, stainless steel, aluminum alloy, or ceramic, in an annular shape. The holding ring member 64 has a through hole 64a into which the small diameter portion 42B of the valve body 42 is inserted at the center. The holding ring member 64 is formed with grooves 64G wider than the grooves 44G on both end surfaces in the thickness direction so as to face three locations. The grooves 64G are formed at intervals of 120 ° along the circumferential direction of each annular surface, and cross the annular surface along the radial direction. A through hole 64H is formed in the groove 64G.

  Accordingly, the holding rings shown in FIGS. 7A to 7C each have a plurality of types of prevention of liquid sealing, prevention of creep of the valve element 42 (prevention of loosening), and prevention of sticking to the stopper portion 10S. It has the function of

  FIG. 8 schematically shows the configuration of another example of the control valve according to the present invention together with a pipe for piping.

  In FIG. 8, the control valve is, for example, a normally closed electromagnetic valve, and is arranged in a pipe in the refrigerant circuit in the air conditioner. The piston unit of the electromagnetic valve shown in FIG. 2 is configured to include a cylindrical piston member 36, a valve body 42, and a holding ring member 44. In the example shown in FIG. The piston unit of the valve includes a piston member 48 that is a solid shaft, a valve body 42, and a holding ring member 44. In FIG. 8, the same components in the example shown in FIG. 2 are denoted by the same reference numerals, and redundant description thereof is omitted.

  The solenoid valve includes a piston unit movably disposed in the plunger tube 26, a valve main body 50 coupled to one end of the plunger tube 26, and an attractor 24 and a piston which are disposed on the outer peripheral portion of the plunger tube 26 and will be described later. And an electromagnetic coil unit for selectively exciting the unit as main elements.

  The electromagnetic coil unit mainly includes a coil portion 20 disposed on the outer peripheral portion of the plunger tube 26, an attractor 24 that closes one end of the plunger tube 26, and a casing 16 that covers the coil portion 20 and is housed inside. It is configured. The coil unit 20 is electrically connected to a drive control unit (not shown) via a lead wire 22. One end surface of the attractor 24 receives one end of the coil spring 30. The coil spring 30 is disposed between one end face of the suction member 24 and the bottom of the concave portion of the piston member 48, and biases the piston member 48 away from the suction member 24, that is, toward the valve body. It is supposed to be.

  The valve body 50 is made of a metal material, for example, brass, stainless steel, aluminum alloy, and the like, and has a piston unit housing portion 50A that houses the piston unit inside. The piston unit housing portion 50 </ b> A has an inlet port 50 </ b> PI to which one end of the high-pressure side pipe 12 as a first passage is connected on an axis substantially orthogonal to the center axis of the piston member 48, and the center of the piston member 48. An outlet port 50PE to which one end of the low-pressure side piping pipe 14 serving as a second passage is connected is formed on an axis common to the axis.

  An annular valve seat 50V is formed at the opening end of the outlet port 50PE in the inner periphery of the piston unit housing 50A. A valve body 42 as a seal member is selectively brought into contact with the arcuate tip of the valve seat 50V. A flat stopper portion 50S is formed around the periphery of the valve seat 50V. The stopper portion 50S is formed on a common plane with the base end of the valve seat 50V. Thereby, when the piston member 48 is pushed down, the lower end of the pushed-down piston member 48 is positioned at a predetermined position by bringing the holding ring member 44 into contact with the stopper portion 50S.

  Therefore, the piston unit drive mechanism described later includes an electromagnetic coil unit and a coil spring 30.

  The piston unit includes a piston member 48 that is movably disposed in the piston unit housing portion 50A of the valve main body 50 described above, and a valve body 42 as a seal member that is held in the first recess 48C of the piston member 48. And a retaining ring member 44 that is locked to the valve body 42 and holds the valve body 42 in the first recess 48C of the piston member 48.

  The solid shaft piston member 48 is made of, for example, a magnetic material, and has a hole into which one end of the coil spring 30 is inserted, as shown in FIG.

  An annular first recess 48 </ b> C into which the valve body 42 is inserted is formed at the other end of the piston member 48. The maximum diameter Dc of the inner periphery of the first recess 48C is set slightly larger than the maximum diameter of the valve body 42 with a predetermined gap. The maximum diameter Dc is set smaller than the diameter Db around the central axis of the valve body 50 at the falling part of the stopper 50S of the valve body 50. As a result, the pressing force of the piston member 48 is received by the stopper portion 50S of the valve body 50 via the holding ring member 44 without applying a bending moment to the holding ring member 44, and will be described later. The caulking portion 48E is not damaged, and an increase in creep of the valve body 42 is avoided.

  Furthermore, an annular second recess 48D having a diameter larger than the maximum diameter Dc of the inner periphery of the first recess 48C is formed at the periphery of the first recess 48C. A holding ring member 44 is inserted into the second recess 48D.

  The holding ring member 44 is locked by a caulking portion 48E formed at the tip of the piston member 48 and is held by the second recess 48D. The caulking portion 48E is formed over the entire circumference. The caulking portion 48E is formed with a predetermined caulking allowance by pressing after the valve body 42 and the holding ring member 44 are sequentially attached to the first recess 48C and the second recess 48D. At that time, a part of the caulking portion 48E is pushed into each groove 44G of the holding ring member 44.

  The diameter Da around the central axis of the piston member 48 at the tip of the caulking portion 48E is set to be larger than the diameter Db described above. Thereby, as shown in FIG. 8, when the piston unit closes the outlet port 50PE, there is no possibility that the tip of the caulking part 48E interferes with the falling part of the stopper part 50S of the valve body part 50. The caulking portion 48E is not limited to such an example, and may be individually formed at a plurality of locations separated along the circumferential direction, for example.

  In such a configuration, when the attractor 24 and the piston member 48 are not excited by the coil portion 20, the valve body 42 comes into contact with the valve seat 50V as shown in FIG. Fluid is shut off. On the other hand, when the attractor 24 and the piston member 48 are excited by the coil portion 20, the attractor 24 and the piston member 48 are brought close to each other by the mutual attraction force, and the valve body 42 of the piston member 48 is biased by the coil spring 30. Against the valve seat 50V. At that time, the working fluid is supplied into the piston unit housing 50A. Therefore, the working fluid from the high-pressure side piping pipe 12 is supplied to the low-pressure side piping pipe 14 along the direction indicated by the arrow F in FIG. Thereafter, when the attractor 24 and the piston member 48 are not excited, the valve body 42 comes into contact with the valve seat 50V by the urging force of the coil spring 30, and the working fluid from the high-pressure side pipe 12 is shut off.

  In the example shown in FIGS. 7A to 7C described above, the groove of the holding ring member is formed at three or four locations on the annular surface, but is limited to such an example. Alternatively, the groove may be provided at least at one place or at five places or more.

  In the above-described example, an example of the control valve according to the present invention is applied to an electromagnetic valve including a piston member, but is not limited to such an example. For example, as shown in Patent Document 3, You may apply to a pilot-type solenoid valve provided with the valve body holder which has a pilot hole in an axial center part.

DESCRIPTION OF SYMBOLS 10 Valve main-body part 28 Plunger 36 Piston member 42 Valve body 44,54,64 Ring member for holding | maintenance

Claims (7)

A piston unit that has an inlet port connected to the first passage and an outlet port connected to the second passage, communicates with the inlet port and the outlet port, and controls the opening and closing of the outlet port is movable. A valve main body provided with an accommodating portion for accommodating in,
A piston unit drive mechanism that causes the piston unit to perform an operation of opening and closing the outlet port;
The piston unit is a seal member that selectively contacts a valve seat formed at a peripheral edge of the outlet port, and a retaining ring member that is engaged with the seal member and holds the seal member. And a holding ring member having a groove communicating with a gap formed around the seal member and a passage continuing to the groove at an end contacting the seal member. Control valve to do.   2. The holding ring member has at least one radially extending groove formed on each of opposite end faces and a chamfered portion connected to the groove forming a passage around the outer peripheral portion. The control valve described.   2. The control valve according to claim 1, wherein each of the holding ring members has at least one groove extending in a radial direction and a through hole penetrating in a thickness direction on each of end faces facing each other. The piston unit includes a piston member having a first recess and a second recess for receiving the seal member and the holding ring member, respectively, facing a valve seat formed on a peripheral edge of the outlet port. first gap between the inner periphery of the recess, claim 2 Symbol placement of the control valve, characterized in that communicating with the groove and the chamfered portion of the retaining ring member outer circumference and the piston member of the member.   A part of the annular portion of the seal member is inserted into a part of the groove of the holding ring member, and a part of the peripheral edge of the second recess of the piston member is a part of the groove of the holding ring member. The control valve according to claim 4, wherein the control valve is pushed into another part connected to the part.   5. The control valve according to claim 4, wherein when the piston unit closes the outlet port, the holding ring member comes into contact with a stopper portion connected to a valve seat formed at a peripheral edge of the outlet port. .   The diameter of the valve body portion around the central axis at the falling portion of the stopper portion of the valve body portion is larger than the maximum diameter of the inner peripheral portion of the first recess of the piston member. Item 7. The control valve according to Item 6.

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