JP2013019442A - Check valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a check valve capable of smoothly flowing fluid suppressing a flowing channel resistance when the valve is opened by enhancing a sealing performance when the valve is closed by stably actuating a disc by suppressing the inclination and vibration of the disc while simplifying an inside structure and making the whole body lightweight by reducing the number of parts.SOLUTION: An annular valve seat 8 is formed in a flow inlet 5 side of a body 1 with an integral structure having the flow inlet 5 and a flow outlet 6, the disc 2 opening and closing the annular valve seat 8 and a spring 3 elastically biasing the disc 2 to the annular valve seat 8 are inserted into the body 1, one end of the spring 3 is mounted to a spring mounting a part 9 located in an outer periphery side of the disc 2, the other end is mounted to a spring receiving part 10 integrally formed in the body 1 side, and the spring mounting part 9 and the spring receiving part 10 are not less than the bore diameter Db of the body 1.

Description

  The present invention relates to a check valve used for various pipes in order to keep a fluid flow in one direction and prevent backflow.

Conventionally, as this kind of check valve, for example, the check valve of Patent Document 1 is known. This check valve has a cylindrical outlet member forming a body, an inlet member forming a cap, a valve body, a valve shaft for fixing the valve body, and a spring, and a valve box is provided by screwing the body and the cap. In this valve box, a valve shaft having a valve body fixed is attached in a state of being biased through a spring. The spring is guided to the outer peripheral side of the valve shaft, and is interposed between the back side of the valve body and a shaft support portion formed in the body.
The spring-biased check valve of Patent Document 2 has a cylindrical outlet member that forms a body, an inlet member that forms a cap, a valve body, a spring receiver, and a coil spring, and a valve chamber is formed by the body and the cap. Yes. In this valve chamber, a coil spring is mounted in a compressed state near the center of the flow path between the valve element back side and the spring receiver, and the valve element is urged in the valve closing direction by this coil spring.
These check valve bodies and caps, valve bodies, valve shafts, spring receivers, and springs are usually made of metal, and the check valves are formed on the body and cap, so various types of pipes such as vertical piping are provided via screws. Joined to piping. When the fluid flows from the primary side, the valve body is pushed to the secondary side, the fluid flows, and when a reverse pressure is applied from the secondary side, the valve is closed by the spring biasing force of the spring and the reverse flow is generated. Is prevented.

JP 2009-138888 A Japanese Patent No. 3924045

  However, the check valves of Patent Documents 1 and 2 use a valve shaft and a spring receiver to mount the valve body in the body, and the body and cap can be attached and detached to mount these components inside. It has a separate structure. Thus, in these check valves, the body, cap, valve body, valve stem (spring receiver), and spring (coil spring) become indispensable parts, so the number of parts increases, and these parts are made of metal. As a result, the overall weight also increases. Furthermore, since the structure is complicated, the number of processed surfaces increases, and it takes time to manufacture. When assembling the check valve, remove the cap from the body, attach the valve stem (spring receiver) and spring (coil spring) to the specified position in the body, and then attach the valve body. It took time and effort to install and integrate.

  In addition, these check valves are supported near the center of the valve body by a spring or coil spring, and the distance from the support position by this spring or coil spring to the outer peripheral end side of the valve body is separated. On the outer peripheral side of the valve body, the inclination and the shake tend to increase with respect to the axial direction. In order to prevent this, as described above, in the same document 1, the valve body is guided by the valve shaft mounted in the body, and in the same document 2, the valve body is mounted while receiving the coil spring by the spring receiver provided in the body, Each is trying to ensure accuracy during valve operation, but there is no difference in the distance from the support position of the spring or coil spring to the outer periphery of the valve body. It is difficult to suppress. For this reason, the sealing performance when the valve is closed cannot be reliably exhibited, and there is a risk of leakage.

  The present invention has been developed to solve the above-described problems, and the object of the present invention is to reduce the number of parts, simplify the internal structure and reduce the overall weight, An object of the present invention is to provide a check valve capable of improving the sealing performance when the valve is closed by suppressing the vibration and stably operating the disc.

  In order to achieve the above-mentioned object, the invention according to claim 1 is a disc in which an annular valve seat is formed on the inlet side of an integral structure body having an inlet and an outlet, and the annular valve seat is opened and closed in the body. And a spring for elastically urging the disc toward the annular valve seat side, one end of the spring being attached to a spring mounting portion located on the outer peripheral side of the disc, and the other end being integrally formed on the body side. And a check valve in which the spring mounting portion and the spring receiving portion are equal to or greater than the bore of the body.

  The invention according to claim 2 is a check valve in which the spring is a coil spring, and the coil diameter of the coil spring is equal to or greater than the diameter of the body.

  According to a third aspect of the present invention, a guide protrusion for mounting one end of the spring is formed on the outer peripheral portion of the disc, and the guide protrusion is slidably guided on a sliding surface formed on the inner peripheral surface of the body. This check valve is a non-return valve in which the sliding surface is a sliding area when the disk slides from the annular valve seat to the stepped disk stopper formed on the inner peripheral surface of the body. .

  According to a fourth aspect of the present invention, there is provided a disk stopper in which one end of a coil spring is mounted in a mounting groove formed on a guide projection, and the other end is mounted on a stepped spring receiving portion formed on the outlet side of the body. This is a check valve having a second valve chamber in a region from the part to the spring receiving part.

  The invention according to claim 5 is the check valve in which the large diameter portion side of the coil spring is mounted on the mounting groove of the guide projection and the small diameter portion side is mounted on the spring receiving portion.

  The invention according to claim 6 is the check valve in which the protrusion outer peripheral surface of the guide protrusion is formed in a substantially spherical shape, and the protrusion outer peripheral surface is slidably provided on the sliding surface.

  The invention according to claim 7 is a check valve in which the guide protrusions are distributed at an angle of 25 ° to 35 ° from the disk center line so as to protrude at least at four or more locations.

  According to an eighth aspect of the present invention, a disc insertion recess for insertion into the body is provided in a part of the bore on the outlet side of the body, and a disc can be inserted into the body through the disc insertion recess, or the first valve chamber This is a check valve in which a disc insertion recess is provided at the back corner of the disc so that the disc can be inserted into the body.

  According to the first aspect of the present invention, since the body is provided in an integral structure, it can be configured with the minimum number of parts including the body, the disc, and the spring, so that the number of parts is reduced and the internal structure is simplified and the overall weight is reduced. In addition, the integrated body makes it possible to reduce the inter-surface dimension while improving the strength while reducing the overall size. Since there are few processing surfaces, it is easy to manufacture and easy to assemble, so it can contribute to resource saving, energy saving, and improvement of environmental resistance performance while keeping costs down. Since the shape of the disc is simple, the disc can be reduced in weight, and this reduction in the weight reduces the cracking pressure and improves the disc operation. When the fluid flows, while the external structure of the body is reliably suppressed by the body structure, the disc is removed by the spring provided between the spring mounting part and the spring receiving part provided at or equal to the diameter of the body. The disc can be stably operated while holding the outer peripheral side and suppressing tilting and swinging in the axial direction, and can be seated accurately on the annular valve seat to improve the sealing performance when the valve is closed. On the other hand, when the valve is opened, a member for holding the disc other than the spring is not required, so that a wide flow path is ensured and fluid can flow smoothly.

  According to the second aspect of the present invention, by making the coil diameter of the coil spring equal to or greater than the diameter of the body, the alignment of the disk is improved and the disk is prevented from swinging up, down, left and right. It can be operated smoothly and accurately seated on the annular valve seat to reliably prevent leakage when the valve is closed.

  According to the third aspect of the present invention, the disc is slid while guiding the guide protrusion to the sliding surface to prevent the disc from tilting or swinging, and the disc is moved in parallel to be perpendicular to the annular valve seat. Can be seated from. Since the first valve chamber from the annular valve seat to the disc stopper portion is a sliding area where the disc slides, the disc is prevented from coming out from the first valve chamber to the secondary side.

  According to the invention which concerns on Claim 4, the operation | movement of a disc is stabilized by mounting | wearing a predetermined position with a spring via a mounting groove and a spring receiving part. By holding the spring between the mounting groove and the spring receiving portion, it is possible to prevent the spring or the disc from coming off to the primary side and maintain a predetermined mounting state. By setting the area from the disk stopper portion to the spring receiving portion as the second valve chamber, when the operation of the disk is restricted in the first valve chamber by the disk stopper portion, the second valve chamber becomes the spring accommodating region, The disc can be operated by the stable elasticity of the spring while preventing excessive compression of the spring.

  According to the fifth aspect of the present invention, the coil spring has a large-diameter side mounted on the mounting groove and the small-diameter side is mounted on the spring receiving part and receives the large-diameter side disk of the coil spring. The disc can be reciprocated in a stable state while maintaining the angle.

  According to the sixth aspect of the present invention, the guide protrusion is slid on the sliding surface via the substantially spherical protrusion outer peripheral surface, thereby absorbing the play by the protrusion outer peripheral surface and The disc can be reciprocated while minimizing the swing, and the disc can be accurately seated on the annular valve seat to improve the sealing performance. In addition, since the sliding resistance can be suppressed by the outer peripheral surface of the protrusion, the guide protrusion can be operated smoothly.

  According to the seventh aspect of the present invention, the guide projection can be smoothly operated in a state where the resistance against the sliding surface is low, and the guide projection is formed at four or more locations while preventing inclination. The disc can be operated while maintaining the squareness in the axial direction, and the flow rate when the valve is open can be secured.

  According to the eighth aspect of the present invention, the disc can be easily mounted at a predetermined position by inserting the disc from the disc insertion recess into the integral structure body, and the disc can be inserted even if the disc has a large diameter and the flow rate is increased. This disc can be inserted from the recess.

It is a longitudinal cross-sectional view which shows one Embodiment of the non-return valve of this invention. It is a longitudinal cross-sectional view which shows the valve open state of the non-return valve of FIG. (A) is the perspective sectional view which showed the temporary attachment state of the disc. (B) is the partially expanded perspective view which showed the protrusion for guides. (A) is the AA end elevation of FIG. (B) is a partially expanded sectional view of (a). It is BB sectional drawing of FIG. It is the longitudinal cross-sectional view which showed the state which started mounting | wearing of a disc. It is a longitudinal cross-sectional view which shows the state which inserted the disc from the state of FIG. It is a longitudinal cross-sectional view which shows the state which inserted the disc further from the state of FIG. It is a longitudinal cross-sectional view which shows other embodiment of the non-return valve of this invention.

Hereinafter, embodiments of a check valve according to the present invention will be described in detail with reference to the drawings. 1 and 2 show an embodiment of the check valve of the present invention.
The check valve of the present invention is connected to a fluid pipe such as water, oil, gas, etc., not shown, and has a metal body 1, a disc 2, and a spring 3, and the disc 2 and the spring 3 are inserted into the body 1. ing.

  As shown in FIGS. 1 and 2, the body 1 is provided in an integral structure having an inflow port 5 and an outflow port 6, a valve chamber 7 is provided inside the body 1, and an annular shape is formed on the inflow port 5 side. A valve seat 8 is formed. In the body 1, the inlet 5 and the valve chamber 7 communicate with the primary side communication port 1 a, and the valve chamber 7 and the outlet 6 communicate with each other through the secondary side communication port 1 b, respectively. Formed on top. Female screws 5a and 6a are formed at the inflow port 5 and the outflow port 6, respectively, and can be joined to the outside via these female screws 5a and 6a.

  In FIG. 3, a stepped disk stopper portion 17 is formed on the inner peripheral surface 13 of the body, and the first valve chamber 15 extends from the annular valve seat 8 to the disk stopper portion 17 on the inner peripheral surface 13 of the body. The disc 2 is slidable in the first valve chamber 15, and a sliding surface 15 a on which the disc 2 slides is formed in the first valve chamber 15. The sliding surface 15 a becomes a sliding area when the disc slides in the first valve chamber 15. The sliding surface 15a is provided smoothly. For example, when the body 1 is cast, it is desirable that the casting surface of the sliding surface 15a be smoothed by a coating mold.

A stepped spring receiving portion 10 is integrally formed on the outlet 6 side of the body. The spring receiving portion 10 is provided in the vicinity of the outer periphery of the secondary side communication port 1b, and the spring 3 can be attached to the spring receiving portion 10.
The region from the disk stopper portion 17 to the spring receiving portion 10 is the second valve chamber following the first valve chamber.

  In this case, as shown in FIG. 8, the inner diameter d1 of the first valve chamber 15 is larger than the outer diameter (maximum outer diameter of the disc 2) d2 formed by the guide projection 12 of the spring mounting portion 9 of the disc 2 described later. Formed in large diameter. Thereby, the disc 2 can be stored in the first valve chamber 15, and the disc 2 can slide on the sliding surface 15 a of the first valve chamber 15 as described above. The second valve chamber 16 is formed on the secondary side of the first valve chamber 15 with an inner diameter d3 having a smaller diameter than the guide protrusion 12 of the disc 2. Thus, by providing a difference between the inner diameter d1 of the first valve chamber 15 and the inner diameter d3 of the second valve chamber 16, the above-described disc stopper portion 17 is formed, and the disc 2 is inserted into the disc stopper portion 17. It can be locked. As a result, the reciprocating motion of the disc 2 is restricted within the first valve chamber 15.

  As shown in FIGS. 4 (a) and 4 (b), a disc insertion recess 11 is formed in a part of the diameter on the outflow port 6 side of the body 1 by a width W and a depth H, and this disc insertion is performed. The disc 2 can be inserted into the body 1 from the recess 11 from the outlet 6 side. The disc insertion recess 11 is formed on the lower side of the spring receiving portion 10 in FIG. 4A, but the disc 2 can be inserted into the valve chamber 7 while passing a guide projection 12 of the disc 2 described later. If the width is W and the depth is H, the disc insertion recess 11 can be provided at an appropriate position on the body 1. For this reason, a disc insertion recess 11 indicated by a two-dot chain line is cut out in the back corner 14 of the first valve chamber 15, and the disc 2 can be inserted into the body 1 through the disc insertion recess 11. . In this case, the disc insertion recessed part 11 by the side of the outflow port 6 becomes unnecessary.

  As shown in FIGS. 3A and 5, the disc 2 is formed in a substantially disk shape, and a metal sealing surface 19 is formed on the seating side of the annular valve seat 8. The disc 2 is provided in the body 1 so that the annular valve seat 8 can be opened and closed, and a seal surface 19 seals the annular valve seat 8 by metal touch.

A spring mounting portion 9 is provided at a position on the outer peripheral side of the disc 2, and a guide protrusion 12 is formed to protrude from the spring mounting portion 9, and a mounting groove 22 for spring mounting is formed in the guide protrusion 12. Has been. A spring 3 to be described later is mounted in the body 1 by having one end mounted in the mounting groove 22 of the spring mounting portion 9 and the other end mounted in the spring receiving portion 10 described above.
The diameter Ds of the spring mounting portion 9 (the diameter of the mounting groove 22) Ds and the diameter Du of the spring receiving portion 10 are equal to or greater than the diameter Db of the body 1.

The guide protrusion 12 is slidably provided on the sliding surface 15a of the inner circumferential surface 13 of the body. As shown in FIG. 5, the guide protrusions 12 are distributed at an angle θ of 25 ° to 35 ° with respect to the center line L of the disk 2 and are formed to protrude at least at four or more locations. In the present embodiment, four guide protrusions 12 are provided, and the disc 2 is configured such that the protrusion outer peripheral surface 20 provided on the guide protrusion 12 slides on the sliding surface 15a. Guided into the room 15. The protrusion outer peripheral surface 20 is provided in an arc shape that can slide on the sliding surface 15a. When the number of sliding guide protrusions 12 is increased, the reciprocating motion of the disc 2 can be stabilized by increasing the contact area of the protrusion outer peripheral surface 20 with the sliding surface 15a.
As shown in FIG. 3B, a corner portion 21 is provided on the outer peripheral surface 20 of the protrusion, and the corner portion 21 is formed in a substantially spherical shape. The guide protrusion is configured to operate while the protrusion outer peripheral surface 20 slides on the sliding surface 15a.

  In FIG. 1, the spring 3 is formed of a conical coil spring, and is inserted into the body 1 so as to elastically urge the disc 2 toward the annular valve seat 8 side. The coil diameter Dc1 on the large diameter side of the coil spring 3 is substantially the same as the diameter Ds of the spring mounting portion 9, and the coil diameter Dc2 on the reduced diameter side of the coil spring 3 is the diameter Du of the spring receiving portion 10. It is almost the same diameter. These are all provided to be equal to or greater than the diameter Db of the body 1 and are larger than the port diameter Dp of the disc 2. Thereby, the outer diameter of the whole spring becomes larger than the port diameter Dp of a disk because the coil diameter Dc2 by the side of a reduced diameter part is larger than the port diameter Dp of a disk. As described above, the coil spring 3 is mounted on the mounting groove 22 on the large diameter side, mounted on the spring receiving portion 10 on the small diameter side, and mounted on the disk 2 side on the small diameter side, so that the square angle with respect to the axis P direction of the disk 2 is obtained. Is held and the opening and closing operation is stabilized.

  With the above-described configuration, the check valve is configured such that the disc 2 housed in the body 1 is elastically urged by the spring 3 to operate in the valve closed state, and is operated in the valve open state by the fluid pressure. Yes. As a result, when the fluid pressure from the inflow port 5 becomes larger than the elastic biasing force of the spring 3, the disc 2 is opened as shown in FIG. In this case, as shown in FIG. 1, the disc 2 is closed, and the fluid backflow prevention function is exhibited.

When assembling the check valve, the disc 2 is inserted into the second valve chamber 16 and the first valve chamber 15 in the horizontal direction from the opening side of the outlet 6 as shown in FIG. In this case, since the port diameter Dp of the disc 2 is smaller than the diameter Db of the body 1, it can be easily inserted.
In FIG. 7, the front side of the disc 2 is inserted to the vicinity of the annular valve seat 8 of the first valve chamber 15, and the disc 2 is positioned so that the front guide protrusion 12 is positioned above the first valve chamber 15. When the guide 2 is tilted, the guide protrusion 12 located on the rear side of the disc 2 passes through the disc insertion recess 11 so that the front side of the disc 2 is the first valve chamber 15 and the rear side of the disc 2 is the second valve chamber. 16 is inserted. As described above, the disc 2 is inserted into the valve chamber 7 by the disc insertion recess 11 so that the length of the valve chamber 7 in the axial center P direction is shortened, and the inter-surface dimension (not shown) of the body 1 is minimized. Can be.

  Subsequently, the entire disc 2 is inserted to the vicinity of the first valve chamber 15 as shown in FIG. In this case, the relationship between the inner diameter d1 of the first valve chamber 15, the inner diameter d3 of the second valve chamber 16, and the maximum outer diameter d2 of the disc 2 formed by the guide projection 12 is such that the inner diameter d1 of the first valve chamber 15> disk 2. The maximum outer diameter d2> the inner diameter d3 of the second valve chamber 16, so that the disc 2 can be inserted into the first valve chamber 15 by passing the disc stopper portion 17 while the disc 2 is tilted.

  The spring 3 compressed in this state is inserted into the valve chamber 7 in close contact from the opening side of the outlet 6 and is mounted between the mounting groove 22 of the disc 2 and the spring receiving portion 10 in the valve chamber 7. The disc 2 is attached with the spring 3 biased in the direction of the annular valve seat 8. When the spring 3 is attached to the spring receiving portion 10, the spring 3 covers the disc insertion recess 11 from the valve chamber 7 side, so that the spring 3 and the disc 2 are prevented from jumping out to the outlet 6 side. It is. In this way, the check valve is incorporated into an integral structure in a predetermined state.

As described above, the check valve according to the present invention has the annular valve seat 8 formed on the inlet 5 side of the body 1 having the inlet 5 and the outlet 6, and the disc 2 and the body 1. Since the spring 3 is inserted, one end of the spring 3 is attached to the spring attaching portion 9 located on the outer peripheral side of the disc 2 and the other end is attached to the spring receiving portion 10 integrally formed on the body 1 side. It is possible to provide a non-return valve that prevents the backflow and makes the fluid flow in one direction with the minimum configuration of the body 1, the disc 2, and the spring 3, and reduces the number of parts to reduce the weight. Can do. Furthermore, since there are few processed surfaces, the man-hour at the time of manufacture can be reduced.
At the time of assembling, the disc 2 and the spring 3 can be easily assembled by inserting the disc 2 and the spring 3 into the body 1 from the inlet 5 or the outlet 6 as described above.

  Since the spring mounting portion 9 and the spring receiving portion 10 are equal to or greater than the body diameter Db, and the coil diameters Dc1 and Dc2 of the spring 3 are equal to or greater than the body diameter Db, the guide protrusion In a state where the 12 arcuate outer peripheral surfaces 20 are in contact with the sliding surface 15b, the outer periphery of the disc 2 is held by the spring 3 and is moved in parallel with the axis P while preventing vertical and horizontal tilts and vibrations. The sliding surface 15b can be slid and seated on the annular valve seat 8 while exerting the aligning action. This improves the sealing performance when the valve is closed and prevents leakage. Thus, since the disc 2 is held in the body 1 by the spring 3, a large flow path in the valve chamber 7 can be secured to increase the flow rate.

  At this time, the corner corner 21 of the protrusion outer peripheral surface 20 of the guide protrusion 12 is formed in a substantially spherical shape, and the corner corner 21 of the protrusion outer peripheral surface 20 is made hemispherical and can slide on the sliding surface. Therefore, it is possible to reciprocate the disk 2 while correcting the trajectory in the axis P direction while minimizing the inclination and vibration in the axis P direction by absorbing the backlash by the protrusion outer peripheral surface 20. it can. For this reason, the disc 2 can be accurately seated on the annular valve seat 8 to improve the sealing performance. Moreover, it is possible to smoothly operate the disc 2 while suppressing the sliding resistance by the protrusion outer peripheral surface 21.

FIG. 9 shows another embodiment of the check valve of the present invention. In addition, in this embodiment, the same part as the said embodiment is represented by the same code | symbol, The description is abbreviate | omitted.
In the check valve of this embodiment, a sealing member 31 is provided separately from the disc 30 by a resin material such as PTFE (polytetrafluoroethylene), and the annular concave groove 32 formed in the disc 30 is formed in the sealing member 31. It is attached to. As described above, the seal member 31 can be provided on the disc 30 according to the type of fluid. The soft seal can seal the disc 30 to the annular valve seat 8 to improve the sealing performance. Furthermore, the sealing member 31 can be provided by a rubber material. In the case of PTFE, the seal member 31 can be easily attached to the disc by fixing it to the annular recess 32 by caulking. In the case of a rubber material, a primer is applied to the disc and baked. In either case, back leakage of the sealing member 31 after mounting can be avoided.

  Although not shown, a seal member may be provided on the annular valve seat side. In this case as well, as in the case of the disc 30, a sealing member may be formed of a resin material such as PTFE or a rubber material, and the sealing member may be attached by caulking and fixing.

DESCRIPTION OF SYMBOLS 1 Body 2 Disc 3 Spring 5 Inlet 6 Outlet 8 Annular valve seat 10 Spring receiving part 11 Disc insertion recessed part 12 Guide protrusion 13 Body inner peripheral surface 15 First valve chamber 15a Sliding surface 16 Second valve chamber 17 Disc Stopper part 20 Outer peripheral surface 21 Protrusion outer peripheral surface 22 Mounting groove

Claims (8)

  An annular valve seat is formed on the inflow side of an integrally structured body having an inflow port and an outflow port, and a disc for opening and closing the annular valve seat in the body and the disc is elastically applied to the annular valve seat side. A spring to be urged, and one end of the spring is mounted on a spring mounting portion located on the outer peripheral side of the disc, and the other end is mounted on a spring receiving portion integrally formed on the body side, and the spring mounting portion A check valve characterized in that the spring receiving portion is equal to or greater than the bore of the body.   The check valve according to claim 1, wherein the spring is a coil spring, and a coil diameter of the coil spring is equal to or greater than a diameter of the body.   A guide protrusion for mounting one end of the spring is formed on the outer periphery of the disc, and the guide protrusion is slidably guided on a sliding surface formed on the inner peripheral surface of the body. The moving surface is defined as a sliding region when the disc slides in the first valve chamber from the annular valve seat to a stepped disc stopper formed on the inner peripheral surface of the body. Check valve.   One end of the coil spring is mounted in a mounting groove formed on the guide protrusion, and the other end is mounted on a step-like spring receiving portion formed on the outlet side of the body, and the spring from the disk stopper portion. The check valve according to any one of claims 1 to 3, wherein a region up to the receiving portion is a second valve chamber.   The check valve according to claim 4, wherein a large diameter portion side of the coil spring is mounted on the mounting groove of the guide projection, and a small diameter portion is mounted on the spring receiving portion.   The check valve according to any one of claims 3 to 5, wherein a protrusion outer peripheral surface of the guide protrusion is formed in a substantially spherical shape, and the protrusion outer peripheral surface is slidably provided on the sliding surface. .   The check valve according to any one of claims 3 to 6, wherein the guide protrusions are distributed at an angle of 25 ° to 35 ° with respect to the center line of the disc and protruded to at least four locations.   A disc insertion recess that is inserted into the body is provided in a part of the diameter on the outlet side of the body, and a disc can be inserted into the body from the disc insertion recess, or a disc is inserted into the back corner of the first valve chamber. The check valve according to any one of claims 1 to 7, wherein a recess is provided so that the disc can be inserted into the body.

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