JP5981562B2 - Check valve - Google Patents

Description

  The present invention relates to a check valve having a valve body that allows fluid flow in one direction and blocks flow in the reverse direction.

  The check valve is also referred to as a check valve, and is used in a fluid pressure flow path for guiding fluid such as compressed air or liquid. The check valve is used to allow the fluid to flow only in one direction and prevent the fluid from flowing in the reverse direction. Have. The check valve has a valve housing in which a first port to which a first pipe for guiding fluid is connected and a second port to which a second pipe is connected are formed. The valve body mounted in the flow path between both ports moves freely in the axial direction, and is positioned at a position where it opens away from the valve seat and a position where it closes and closes the valve seat To do.

  In a check valve in which the valve body is a poppet type, the valve body is moved in the axial direction to open and close the valve seat. A check valve having a poppet-type valve body has a form in which a valve body that opens and closes a valve seat is attached to an outflow hole so as to be movable in an axial direction, as described in Patent Document 1. In Patent Document 1, an annular valve seat is provided at a boundary portion between an inflow hole of a valve housing and an outflow hole having an inner diameter larger than the inflow hole. In this check valve, the valve body is provided with a conical head at one end, and the base on the other end is provided with a cylinder that slides on the inner surface of the outflow hole. A communication hole for guiding the fluid flowing into the outflow hole to the outside is provided in the base.

  As another type of check valve, as described in Patent Document 2, a cylindrical base portion that slides on the inner surface of the small-diameter hole on the inflow side, and a head provided with an annular protrusion that opens and closes the valve seat are provided. Some have a valve body with a portion. In this check valve, when the annular projection moves to a position away from the valve seat, a cross passage formed in the cylindrical base portion connects the small diameter hole on the inflow side and the large diameter hole on the outflow side.

Japanese Utility Model Publication No. 48-69135 Japanese Patent Laid-Open No. 11-6574

  As described above, in a check valve having a poppet-type valve body, a bottomed axial communication hole having a bottom surface on the head side of the valve body is formed inside the valve body. Further, a radial communication hole is formed in the valve body so that the axial communication hole communicates with the outflow hole when the valve body is separated from the valve seat.

  To prevent fluid leakage from between the valve seat and the valve body when the valve body closes the valve seat, make sure that the head of the valve body is in close contact with the valve seat surface to improve the sealing performance of the valve seat. Need to increase. When the valve body is tilted and contacts the valve seat, the sealing performance of the valve seat is lowered and leakage from the valve seat occurs. In order to improve the sealing performance of the valve seat, the coaxiality between the central axis of the valve body and the central axis of the communication hole that accommodates the valve body is set so that the valve body does not tilt when the valve body moves in the axial direction. Need to increase. Increasing the axial length of the sliding portion of the valve body can increase the coaxiality, but the axial dimension of the valve body is increased and the check valve cannot be reduced in size.

  When the valve seat is released from the valve seat, the fluid flows from the inflow hole to the outflow hole through the communication hole of the valve body. In order to secure the flow rate at this time, it is necessary to increase the communication opening degree of the communication hole of the valve body. If the sliding part is divided and provided on both the head side and the base side of the valve body, the coaxiality during sliding of the valve body can be improved without increasing the axial length of the entire sliding part. However, if the sliding portion is provided on the head side of the valve body, the communication opening cannot be sufficiently secured.

  An object of the present invention is to provide a check valve that can ensure a fluid flow rate when the valve seat is opened without increasing the axial length of the valve body.

  An object of the present invention is to provide a check valve capable of enhancing the sealing performance when the valve seat is closed while ensuring the fluid flow rate when the valve seat is opened.

The check valve according to the present invention includes a first communication hole that opens to the first port and a second communication hole that opens to the second port, and the first and second communication holes A valve housing in which a valve seat is formed at a boundary portion and an axially slidable attachment to the second communication hole, the valve seat is opened, and the second communication hole is opened from the first communication hole. A valve body that allows the flow of fluid toward the valve, blocks the valve seat and blocks the flow in the opposite direction, and is mounted on the second communication hole, and the valve body has a spring force toward the valve seat. A spring member for biasing, and the valve body is provided on one end portion side of the valve body and opens and closes the valve seat, and is provided on the other end side with respect to the head portion. a sliding surface that slides inside surface of the second communication holes, said a diameter is than the sliding surface provided between said head portion and said sliding surface and the It has a communication with the outer circumferential surface which forms a guide passage between the inner periphery of the communicating hole, and a radial step surface between the sliding surface and the communicating outer peripheral surface, the other of said valve body An axial communication hole that opens in the end surface and extends in the axial direction toward one end of the valve body is formed in the valve body, and extends in the radial direction to communicate the axial communication hole and the guide channel. A directional communication hole is formed in the valve body by opening it in the sliding surface and the communication outer peripheral surface.

  A radial communication hole is formed across the sliding surface that is in sliding contact with the inner peripheral surface of the second communication hole and the communication outer peripheral surface that forms the guide channel, and a part of the sliding surface is in radial communication. A hole is formed. Therefore, the axial length of the sliding surface can be increased without increasing the axial length of the valve element. Thereby, it can prevent that a valve body inclines at the time of valve body movement, and can improve the sealing performance of the valve seat when a valve body obstruct | occludes a valve seat, without enlarging a check valve.

  The radial communication hole is formed across the communication outer peripheral surface and the sliding surface. That is, the radial direction communication hole has an opening portion opened in the radial direction on the communication outer peripheral surface and an opening portion opened in the axial direction so as to face the guide flow channel, and communicates with the guide flow channel. Thereby, when the valve seat is opened away from the valve seat, the communication opening degree between the guide channel and the radial communication hole can be increased. Therefore, the fluid flow rate when the valve seat is opened can be increased without increasing the axial length of the valve body.

It is sectional drawing which shows the non-return valve which is one Embodiment in the state which closed the valve seat with the valve body. It is sectional drawing which shows the non-return valve of FIG. 1 in the state which opened the valve seat with the valve body. FIG. 3 is an enlarged perspective view of the valve body shown in FIGS. 1 and 2. (A) is a front view of FIG. 3, (B) is sectional drawing of FIG. (A) is a front view which shows the modification of a valve body, (B) is a longitudinal cross-sectional view of (A). It is sectional drawing which shows the non-return valve as a comparative example. It is an expanded sectional view of the valve body shown by FIG. It is sectional drawing which shows the non-return valve as another comparative example. It is an expanded sectional view of the valve body shown by FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, the check valve 10 has a valve housing 12 in which a stepped through hole 11 is formed. A first port 13 is formed at one end of the through hole. A joint 14 is attached to the first port 13. A second port 15 is formed at the other end of the through hole 11. A joint 16 is attached to the second port 15. As shown in FIG. 1, pipes 17 and 18 made of hoses and pipes for guiding air are attached to the joints 14 and 16, respectively.

  The through hole 11 includes a first communication hole 21 that opens to the first port 13 and a second communication hole 22 that opens to the second port 15. The inner diameter of the second communication hole 22 is larger than the inner diameter of the first communication hole 21. A valve seat 23 is provided at the boundary between the first communication hole 21 that is a small-diameter communication hole and the second communication hole 22 that is a large-diameter communication hole. The valve seat 23 has a tapered surface having an inner diameter that increases from the first communication hole 21 toward the second communication hole 22. Instead of the tapered surface, the valve seat 23 may be a radial surface perpendicular to the axial direction of the communication holes 21 and 22.

  A valve body 24 is attached to the second communication hole 22 so as to be slidable in the axial direction. An annular groove 27 in which a seal member 26 is mounted is formed in a head 25 provided at one end of the valve body 24. The seal member 26 attached to the head portion 25 of the valve body 24 opens and closes the valve seat 23 by sliding the valve body 24 in the axial direction. As shown in FIG. 1, when the seal member 26 of the valve body 24 is in close contact with the valve seat 23, the valve seat 23 is closed. On the other hand, as shown in FIG. 2, when the seal member 26 of the head portion 25 of the valve body 24 is separated from the valve seat 23, the valve seat 23 is opened.

  As shown in FIGS. 3 and 4, the other end side of the valve body 24 is a base portion 28 integrated with the head portion 25, and the base portion 28 is provided with a cylindrical sliding portion 31. . The outer diameter of the sliding portion 31 is larger than the outer diameter of the head 25. The sliding portion 31 has a sliding surface 32 that comes into sliding contact with the inner peripheral surface of the second communication hole 22. A spring mounting portion 33 having a smaller diameter than the sliding portion 31 and a small diameter sliding portion 34 having a smaller diameter than the spring mounting portion 33 are provided on the base portion 28. As shown in FIGS. 1 and 2, an annular spring receiving member 35 is attached to the second communication hole 22. A compression coil spring 36 is mounted between the spring receiving member 35 and the sliding portion 31. The compression coil spring 36 biases the spring force in the direction toward the valve seat 23 against the valve body 24. One end of the compression coil spring 36 is in contact with the end surface of the spring receiving member 35, and the other end of the compression coil spring 36 is in contact with the radial end surface 37 between the sliding portion 31 and the spring mounting portion 33.

  The small-diameter sliding portion 34 has a small-diameter sliding surface 38 that is in sliding contact with the inner peripheral surface of the spring receiving member 35. As a result, when the valve body 24 moves in the axial direction, the sliding surface 32 at the central portion in the axial direction of the base portion 28 comes into sliding contact with the second communication hole 22, and the small-diameter sliding at the end portion of the base portion 28. The surface 38 is in sliding contact with the inner peripheral surface of the spring receiving member.

  Between the head 25 and the sliding portion 31, a flow path forming portion 41 having a smaller diameter than the sliding portion 31 is provided. A communication outer peripheral surface 43 is provided between the outer peripheral surface of the head 25 and the sliding surface 32. The communication outer peripheral surface 43 forms a guide channel 42 between the communication outer peripheral surface 43 and the inner peripheral surface of the second communication hole 22. As shown in FIG. 4B, an axial communication hole 44 extending in the axial direction is formed inside the valve body 24. The axial communication hole 44 is open to the other end surface of the valve body 24, that is, the end surface of the base portion 28, and is a bottomed hole having a bottom surface on the head 25 side. A radial communication hole 45 is formed in the valve body 24. The radial direction communication hole 45 allows the portion on the bottom surface side of the axial direction communication hole 44 to communicate with the guide channel 42. The bottom surface of the axial communication hole 44 has a portion that is continuous with the inner peripheral surface of the radial communication hole 45 without a step, and the bottom surface is in contact with the inner peripheral surface of the radial communication hole 45. A total of four radial communication holes 45 are formed approximately every 90 degrees in the circumferential direction. As shown in FIG. 4B, when the diameter of the axial communication hole 44 is D and the diameter of each radial communication hole 45 is d, the diameter d is smaller than the diameter D.

  Two forces, the air pressure of the second communication hole 22 and the spring force of the compression coil spring 36, are applied to the valve body 24 as thrust in the direction toward the valve seat 23, that is, the direction closing the valve seat 23. Further, the air pressure of the first communication hole 21 is applied to the valve body 24 as a thrust in a direction away from the valve seat 23, that is, a direction in which the valve seat 23 is opened. When the pressure of the air guided by the pipe 17 and supplied to the first communication hole 21 becomes larger than the thrust applied in the direction of closing the valve body 24, the valve body 24 is moved to the valve seat as shown in FIG. The valve seat 23 is opened away from the valve 23. Thus, the air supplied from the pipe 17 to the first communication hole 21 flows into the second communication hole 22 and passes through the radial communication hole 45 and the axial communication hole 44 formed in the valve body 24. It flows out from the pipe 18 to the outside. On the other hand, when the thrust in the direction toward the valve seat 23 becomes larger than the thrust in the reverse direction, the seal member 26 of the valve body 24 comes into close contact with the valve seat 23 and the valve seat 23 is closed. Accordingly, as shown in FIG. 1, the air guided by the pipe 17 and supplied to the first communication hole 21 does not flow into the second communication hole 22. As described above, the check valve 10 allows the flow of fluid from the first communication hole 21 to the second communication hole 22 and prevents the flow from the second communication hole 22 to the first communication hole 21. .

  The radial communication hole 45 is formed at a position straddling the sliding portion 31 and the flow path forming portion 41 in the axial direction. The radially inner end of each radial communication hole 45 opens at the bottom of the axial communication hole 44. The radially outer end of the radial communication hole 45 is open on both the sliding surface 32 of the sliding portion 31 and the communication outer peripheral surface 43 of the flow path forming portion 41 so as to straddle in the axial direction. A semicircular portion of the cross section of the circular radial communication hole 45 is formed in the sliding portion 31, and the remaining semicircular portion is formed in the flow path forming portion 41. An outer end portion of each radial communication hole 45 opens in a radial step surface 46 between the sliding portion 31 and the flow path forming portion 41. In other words, it can be said that the center of the radial communication hole 45 is located at substantially the same position as the axial position of the step surface 46. Therefore, a portion of the outer end that opens to the sliding surface 32 is substantially not opened because it is covered by the second communication hole 22 as shown in FIG. However, there is an edge 47 between the step surface 46 and the outer end portion of the radial communication hole 45, and the communication opening 48 between the edges 47 opens in the axial direction opposite to the guide channel 42. To do.

  As described above, the outer end of the radial communication hole 45 has a portion that opens to the communication outer peripheral surface 43 in the direction along the guide flow path 42, and an opening to the step surface 46 that faces the guide flow path 42 in the axial direction. And a portion to be Thus, when the valve seat 23 is opened, the air supplied from the pipe 17 and flowing into the second communication hole 22 from the first communication hole 21 opens the radial communication hole 45 in the communication outer peripheral surface 43. The gas flows into the radial communication hole 45 from both the part and the part opened to the step surface 46 forming the communication opening 48, and flows out from the pipe 18 through the axial communication hole 44. Therefore, the outer end of the radial communication hole 45 does not open entirely on the communication outer peripheral surface 43, but the radial communication hole 45 via the communication opening 48 that faces the guide channel 42 in the axial direction. And the guide flow path 42 communicate with each other, the flow cross-sectional area of the guide flow path 42 and the axial communication hole 44 can be increased without increasing the diameter of each radial communication hole 45. The total cross-sectional area of the four radial communication holes 45 is set to an area that is equal to or larger than the cross-sectional area of the axial communication hole 44, and the flow resistance of the radial communication holes 45 is that of the axial communication hole 44. It is equal to or smaller than the distribution resistance.

  When the axial length of the valve body 24 is increased, the axial length of the check valve 10 is increased, so that the check valve cannot be reduced in size. For example, if the radial communication hole 45 is formed only in the flow path forming part 41 without straddling the sliding part 31 and the flow path forming part 41, the entire opening of the radial communication hole 45 is communicated with the outer peripheral surface. 43 will open. In that case, since the axial dimension of the flow path forming portion 41 must be increased so that the radial communication hole 45 does not interfere with the annular groove 27, the axial dimension of the valve body 24 becomes longer. In order to open the radial communication hole 45 in the communication outer peripheral surface 43 without increasing the axial dimension of the valve body 24, the axial dimension of the sliding portion 31 is shortened. If it does so, since the valve body 24 will fall easily with respect to an axial direction when the valve body 24 moves to an axial direction, the valve body 24 may incline and may contact the valve seat 23. FIG. When the valve body 24 is inclined and the valve seat 23 is closed, the seal member 26 comes into contact with the valve seat 23 and the sealing performance of the valve body 24 is deteriorated.

  On the other hand, in the illustrated check valve 10, since the radial communication hole 45 is formed so as to straddle the sliding portion 31 and the flow path forming portion 41, the axial length of the sliding portion 31 is increased. can do. As a result, the valve body 24 is unlikely to fall down in the axial direction, so that the seal member 26 can be prevented from coming into contact with the valve seat 23 when the valve seat 23 is closed. Thereby, the sealing performance of the valve body 24 could be enhanced without increasing the length of the valve body 24. In addition, the flow area or flow volume of the radial communication hole 45 can be sufficiently secured.

  As shown in FIG. 4A, the center of the radial communication hole 45 is the position of the step surface 46, and the width dimension, that is, the circumferential dimension of the communication opening 48 is the same as the diameter d. ing. When the center of the radial communication hole 45 is brought closer to the head 25 side in FIG. 4A, the width dimension of the communication opening 48 becomes smaller than the dimension of the diameter d, and the communication outer peripheral surface 43 of the radial communication hole 45 becomes smaller. The area of the opening is larger than the illustrated form. In contrast, when the center of the radial communication hole 45 is moved away from the head 25 side in FIG. 4A, the width dimension of the communication opening 48 is smaller than the dimension of the diameter d and the radial communication is performed. The area of the opening of the communication outer peripheral surface 43 of the hole 45 is also reduced.

  Compared to these cases, when the center of the radial direction communication hole 45 is set to the position of the step surface 46, the width dimension of the communication opening 48 can be maximized, and the flow path area is secured and at the same time the valve body 24 An increase in the axial length can be suppressed. When the center of the radial direction communication hole 45 is brought closer to the head 25 side in FIG. 4A, the area of the opening of the communication outer peripheral surface 43 becomes larger and the flow path area can be secured. Since the axial length becomes long and the axial length of the valve body 24 becomes long, the valve body cannot be downsized.

  The cross-sectional shape of the radial communication hole 45 is not limited to the circular shape described above, and may be an oval or elliptical shape, or may be a rectangular or polygonal shape. In the form in which the radial communication hole 45 is an oval or elliptical shape, the radial communication hole 45 is formed in the valve body 24 such that the major axis faces the radial direction of the valve body 24 and the minor axis faces the axial direction of the valve body 24. Formed. When the long diameter is directed in the radial direction of the valve body 24, the width dimension of the communication opening 48 can be increased, so that the flow area is increased. When the minor axis faces the axial direction of the valve body 24, it is possible to suppress the axial length of the valve body 24 from becoming long. Even in the case of an oval or elliptical shape, the radial communication hole 45 is formed at a position straddling the sliding portion 31 and the flow path forming portion 41 in the axial direction, that is, at a position penetrating the step surface 46 in the axial direction.

  FIG. 5 (A) is a front view showing a modification of the valve body, and FIG. 5 (B) is a longitudinal sectional view of FIG. 5 (A). The cross-sectional shape of the radial communication hole 45 of the valve body 24 is a quadrilateral, that is, a rectangle. The rectangular radial communication hole 45 is formed at a position across the sliding portion 31 and the flow path forming portion 41 in the axial direction, as in the above-described embodiment.

  As shown in FIGS. 1 and 2, the valve housing 12 is provided with a bypass portion 51, and a valve mounting hole 52 is formed in the bypass portion 51. A flow path 53 a that connects the guide flow path 42 and the valve mounting hole 52, and a flow path 53 b that connects the flow path 53 a and the first communication hole 21 via the valve mounting hole 52 are formed in the valve housing 12. Has been. A bypass flow path 53 that connects the guide flow path 42 and the first communication hole 21 is constituted by both the flow paths 53a and 53b. An opening adjustment valve 54 is provided in the valve mounting hole 52 in order to adjust the opening of the bypass passage 53. The opening adjustment valve 54 has a screw shaft 56 with a needle valve 55 provided at the tip, and a rotation operation portion 57 is provided at the base end of the screw shaft 56. When the screw shaft 56 is rotated, the needle valve 55 moves in the axial direction, and the opening degree of the bypass passage 53 is adjusted. In order to fix the adjusted opening degree, a lock nut 58 is screwed to the screw shaft 56.

  When the bypass flow path 53 is provided in the check valve 10, the air that flows in from the pipe 18 attached to the second port 15 flows out to the first communication hole 21 through the bypass flow path 53. In this way, the bypass flow path 53 can guide the air that has flowed into the pipe 17 attached to the first port 13.

  Check valves 10a and 10b different from the above-described check valve 10 are shown in FIGS. 6 to 9 as comparative examples. In these drawings, the same reference numerals are given to members having commonality with the members of the check valve 10 described above.

  The valve body 24 of the check valve 10 a shown in FIGS. 6 and 7 has an outer end of the radial direction communication hole 45 opening on the communication outer peripheral surface 43 of the flow path forming portion 41. As described above, the guide channel 42 and the radial communication hole 45 are formed on the opening surface along the communication outer peripheral surface 43 while setting the axial length of the valve body 24 to be the same as that of the valve body 24 of the check valve 10 described above. , The axial length of the sliding portion 31 needs to be shortened and the width of the sliding portion 31 needs to be reduced. When this dimension is shortened, when the valve body 24 closes the valve seat 23, air leaks from the first communication hole 21 to the second communication hole 22 through the space between the valve seat 23 and the seal member 26. It has been found by the operation test of the check valve 10a that there is a case. Leakage is likely to occur due to the cumulative number of operations. This is because the axial dimension of the sliding portion 31 is short, so that the central axis of the valve body 24 tends to be inclined with respect to the central axis of the second communication hole 22 when the valve body 24 is opened and closed. It is considered that the seal member 26 is in contact with the valve seat 23 when the valve seat 23 is closed in a state where the valve seat 23 is inclined.

  On the other hand, the valve body 24 of the check valve 10 b shown in FIGS. 8 and 9 is provided with sliding portions 31 a and 31 b on both axial sides of the radial communication hole 45. The sliding portion 31a on the head side is formed with a notch (not shown) for allowing the first communication hole 21 and the radial communication hole 45 to communicate with each other. As described above, when the two sliding portions 31a and 31b are provided on the head side and the base end side of the valve body 24, the valve body 24 is compared with the check valve 10a shown in FIGS. It was possible to prevent the valve body 24 from being inclined during the opening / closing operation. However, when the valve body 24 opens the valve seat 23, the flow of air flowing through the notch is obstructed by the sliding portion 31a on the head side. For this reason, it is inevitable that the flow rate of air when the valve body 24 opens the valve seat 23 is reduced as compared with the check valves 10 and 10a described above.

  In the check valve 10 shown in FIGS. 1 to 4, the radial communication hole 45 is formed across the communication outer peripheral surface 43 and the sliding surface 32. Accordingly, the radial communication hole 45 communicates with the guide flow path 42 by both an opening portion opened in the radial direction on the communication outer peripheral surface 43 and an opening portion opened in the axial direction opposite to the guide flow passage 42. Thereby, when the valve body 24 is opened away from the valve seat 23, the communication opening degree between the guide channel 42 and the radial communication hole 45 can be increased, and the axial length of the valve body 24 is increased. Therefore, the fluid flow rate when the valve seat is opened can be increased. Furthermore, since a part of the radial direction communication hole 45 opens in the communication outer peripheral surface 43, the axial length of the sliding portion 31 can be increased without increasing the length of the valve body 24. The degree of concentricity is ensured when the valve body 24 moves in the axial direction, and the occurrence of per contact of the valve body 24 against the valve seat 23 is prevented. Thereby, the sealing property of the valve seat 23 when the valve seat 23 is obstruct | occluded by the valve body 24 can be improved.

  The valve body 24 is provided with a small-diameter sliding surface 38 away from the sliding surface 32 in the axial direction. The sliding surface 32 slides on the inner surface of the second communication hole 22, and the small diameter sliding surface 38 slides on the inner peripheral surface of the spring receiving member 35. Since these two sliding portions are separated in the axial direction, the inclination of the valve body 24 is further suppressed, and the seal member 26 is further prevented from coming into contact with the valve seat 23 when the valve seat 23 is closed. .

  4A and 4B, a total of four radial communication holes 45 are formed at intervals of 90 degrees in the circumferential direction, but a total of two may be formed at intervals of 180 degrees. In this case, if the diameter of the axial communication hole 44 is D and the diameter of each radial communication hole 45 is d, the diameter d is not necessarily smaller than the diameter D, and the diameter d is the same as the diameter D. It may be.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. The check valve 10 is provided in a pneumatic circuit that guides compressed air, and is used to allow the compressed air to flow only in one direction of the flow path. For example, when a hydraulic fluid or the like is used as a working medium The check valve of the present invention can also be applied.

  This check valve is applied to a pneumatic system for supplying compressed air from a pneumatic source to a pneumatic actuator.

Claims (9)

A first communication hole that opens to the first port and a second communication hole that opens to the second port are formed, and a valve seat is formed at the boundary between the first and second communication holes. A valve housing,
The second communication hole is slidably mounted in the axial direction, and the valve seat is opened to allow a flow of fluid from the first communication hole toward the second communication hole. A valve body that blocks and prevents flow in the opposite direction;
A spring member attached to the second communication hole and biasing a spring force toward the valve seat on the valve body;
The valve body is provided on one end side of the valve body and opens and closes the valve seat, and is provided on the other end side of the head and slides on the inner surface of the second communication hole. A communication surface that is provided between the sliding surface and the head and the sliding surface, has a smaller diameter than the sliding surface, and forms a guide channel between the inner peripheral surface of the second communication hole. An outer peripheral surface, and a radial step surface between the sliding surface and the communication outer peripheral surface ;
An opening in the other end surface of the valve body and an axial communication hole extending in the axial direction toward one end portion of the valve body are formed in the valve body,
A radial communication hole that extends in the radial direction and communicates the axial communication hole and the guide channel is formed in the valve body by opening the sliding surface and the communication outer peripheral surface. Check valve.   2. The check valve according to claim 1, wherein a half of a cross section of the radial communication hole opens in the sliding surface, and the other half opens in the communication outer peripheral surface.   2. The check valve according to claim 1, wherein a bottom surface of the axial communication hole is continuous with a part of an inner peripheral surface of the radial communication hole.   2. The check valve according to claim 1, wherein the radial communication hole has a circular cross section.   The check valve according to claim 1, wherein the radial communication hole has a rectangular cross section.   6. The check valve according to claim 1, wherein an annular spring receiving member with which the spring member abuts is attached to the second communication hole, and slides on an inner peripheral surface of the spring receiving member. A check valve characterized in that a small-diameter sliding surface is provided at the other end of the valve body.   The check valve according to claim 1, wherein a seal member that is in close contact with the valve seat is provided on the head.   The check valve according to any one of claims 1 to 7, wherein a plurality of the radial communication holes are formed in the valve body.   The check valve according to any one of claims 1 to 8, wherein a bypass flow path that connects the guide flow path and the first communication hole is formed in the valve housing, and the bypass flow path is opened. A check valve characterized in that an opening adjusting valve for adjusting the degree is provided in the valve housing.

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