JP2018200064A - Check valve - Google Patents

Abstract

To provide a swing type check valve capable of forcibly regulating rotation of a disc relative to an arm even in any valve opening state from a valve closing state to a full valve opening state, without machining the disc and needing a new component or assembly.SOLUTION: A check valve comprises: an arm 4 pivotally supported in a body 1 having outflow inlets 8, 9; an attachment shaft part 31 of a disc 3 attached to the arm 4; a rotation prevention member 5 arranged around the attachment shaft part 31. The rotation prevention member 5 is locked to the arm 4, and then the rotating disc 3 is regulated from rotating at a predetermined angle.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a check valve, and more particularly, to a swing type check valve that restricts rotation of a disc with respect to an arm.

  Conventionally, a swing type check valve is often used in order to prevent a back flow in a pipe and flow a fluid in only one direction. In a swing type check valve, normally, one side of an arm is pivotally attached to the inside of a valve box by a hinge pin, and a valve body is attached to the other side of the arm with a nut through a washer. With this structure, the valve body is supported in the valve box by the arm, and the arm swings around the hinge pin to open and close the flow path by the valve body.

  In this case, in order to improve the sealing performance between the valve body and the valve seat surface, the valve body is generally mounted in a flexible state in which the valve body freely rotates with respect to the arm, and the valve body is attached to the valve seat surface. It is often moved so as to follow, and both are made to be sealed so as to be compatible with each other. In particular, at an intermediate opening degree of the valve body, the valve body tends to rotate due to the influence of fluid flowing irregularly due to the influence of pump pulsation or the like. If the valve body freely rotates beyond the limit, the contact surface between the valve body and the arm wears, and the clearance between them increases, so that the relative position between the valve body and the valve seat surface is increased. There is a possibility that the sealing performance when the valve is closed is lost.

  As a means for regulating the rotation of the valve body, for example, a check valve of Patent Document 1 is disclosed. In this check valve, a valve stop is formed inside the valve box so that the head of the bolt for fixing the valve body abuts, and the valve stop is provided in a concave shape to be fitted to the bolt head. As a result, the bolt head fits into the concave shaped portion of the valve stop, and attempts to suppress the rotation and vibration of the valve body when the valve is fully opened.

  In the swing type check valve of Patent Document 2, an abrasion-resistant hard material is welded to a fitting contact portion between an arm and a valve body, and a curvature surface or an inclined surface is formed. Thus, the rotational motion and swinging motion of the valve body are reduced, and the occurrence of wear on the contact surface between the arm and the valve body is prevented to ensure the soundness of the check surface.

  On the other hand, as other means for restricting rotation of the valve body, two protrusions are provided integrally with the valve body on the surface opposite to the sealing surface of the valve body, and the arm is sandwiched between these protrusions. Swing check valves with a body attached are known. In the case of this check valve, when the valve body is about to rotate, the arm comes into contact with the protrusion of the valve body and its rotation is restricted.

  Matters concerning the regulation of the rotation of the valve body with respect to these arms are defined as one of the important specifications of the industrial check valve. For example, API 594 which is a standard of API (American Petroleum Institute) stipulates that “the assembly design of the disc (valve body) is to limit the rotation of the disc to less than 360 °”. Thus, for example, even when a check valve is piped near the secondary side of a bent flow path such as an elbow and force is constantly applied in the rotation direction of the disk due to the vortex, the contact portion due to continuous rotation of the disk This prevents wear and prevents problems such as disk dropping out.

JP-A-6-307559 JP-A-3-149471

  In the check valve described in Patent Document 1, rotation of the valve body when fully opened is attempted to be suppressed by a valve stop, and an intermediate opening other than when fully opened and rotation of the valve body when the valve is closed are prevented. It is not possible. For this reason, in the swing range of the valve body other than when the valve is fully opened, the valve body easily rotates freely beyond the limit by an angle of 360 ° or more with respect to the arm. In addition, when this type of swing type check valve is used, the valve body rarely swings to the fully open state and is often in an intermediate opening state. Therefore, the valve body is more easily rotated in the intermediate opening state. Thus, since the state of the intermediate opening is long, the frequency of the function of preventing the rotation of the valve body when fully opened is reduced.

  In Patent Document 2, it is difficult to limit the rotation of the disc to less than 360 ° because only the wear-resistant hard material is sandwiched between the fitting contact portion between the arm and the valve body. As described above, when a hard wear-resistant hard material is newly provided between the arm and the valve body and a curvature surface or an inclined surface is formed, the number of parts and the number of assembling steps increase, leading to an increase in cost.

On the other hand, when two protrusions are provided integrally on the surface opposite to the sealing surface of the valve body, these protrusions are newly machined and the interval and height can be used to restrict the movement of the valve body across the arm. Must be set to The protrusion may interfere with machining. For example, when the annular contact surface that is the arm mounting side of the valve body is formed flat, the protrusion becomes an obstacle and processing becomes difficult.
When the distance between the protrusions is narrow, the rotation region of the valve body is narrowed and flexibility is impaired, which may adversely affect the sealing performance, and may not be able to cope with deformation of the body due to application of pressure or the like. The protrusion changes the center of gravity of the valve body, which may lead to a decrease in sealing performance.

  The present invention was developed in order to solve the conventional problems, and the object of the present invention is to open the valve from the closed state to the disk without processing the disc or requiring new parts or assembly. It is an object of the present invention to provide a swing type check valve that forcibly restricts the rotation of the disc relative to the arm in any of the above valve opening states.

  To achieve the above object, an invention according to claim 1 is arranged around an arm pivotally mounted in a body having an outflow inlet, a mounting shaft portion of a disc attached to the arm, and a periphery of the mounting shaft portion. An anti-rotation member, and the anti-rotation member is locked to an arm so that the rotating disc is restricted from rotating at a predetermined angle.

  In the invention according to claim 2, the arm is attached to the mounting shaft portion with a nut through a washer, and the locking piece extended to the washer is locked to a part of the arm to be a rotation preventing member. It is a valve.

  In the invention according to claim 3, an engaging piece is extended to the washer, the engaging piece is engaged with the nut, and the nut and the washer are integrated through a pin through the nut and the engaging piece. Check valve.

  The invention according to claim 4 is the check valve in which the locking plate is attached to the mounting shaft portion between the disc and the arm in a non-rotating state, and the locking plate is used as a rotation preventing member.

  According to the first aspect of the present invention, the rotation preventing member disposed around the mounting shaft portion is locked to the arm and the rotation of the disk is restricted to a predetermined angle, so that the disk can be processed, or a new part or The rotation preventing member can be locked to the arm and forcibly stop the rotation of the disk in any valve opening state from the valve closed state to the valve open state without requiring assembly man-hours. In this way, the disc can be rotated with respect to the arm and the rotation of the disc by 360 ° or more can be regulated, thereby preventing free rotation exceeding the limit of the disc and preventing contact between the disc and the arm. Wear can be prevented, and the compatibility between the disc and the valve seat side when the valve is closed can be ensured to maintain high sealing performance. For this reason, the disc and the arm can be prevented from being damaged or broken, and the disc can be prevented from falling off. By preventing the wear on the body side due to the rotational contact of the disc when fully open, and ensuring a constant movable area of the disc when fully open, it is possible to reliably return the disc to the sealed state when the valve is closed.

  According to the invention which concerns on Claim 2, by making the washer which extended the latching piece into a rotation prevention member, a number of parts and an assembly man-hour do not increase and it becomes easy to assemble. The locking piece can be easily formed by bending and the strength of the locking piece can be secured. Without any new processing on the disc, the current parts are used as they are to ensure sealing performance. Since the distance from the mounting shaft portion to the locking piece can be shortened, the rotation of the disk can be suppressed while suppressing the rotational moment applied to the arm to be small. For this reason, the load applied to the anti-rotation member and the disc is suppressed to prevent wear and contribute to the downsizing of the anti-rotation member.

  According to the third aspect of the present invention, by engaging the engaging piece with the nut and passing the pin through the engaging piece, the anti-rotation member rotates integrally with the nut tightened on the mounting shaft portion. Regulate the rotation of The pin prevents the nut from being loosened or dropped off against the rotation preventing member, and improves the unity of the nut to keep the rotation amount of the disk arm substantially constant.

  According to the fourth aspect of the present invention, by locking the locking plate to the arm, the rotation of the disk with respect to the arm is forcibly stopped in any valve opening state from the valve closed state to the valve open state. Ensures free rotation beyond the limit.

It is a longitudinal cross-sectional view which shows embodiment of the non-return valve in this invention. FIG. 2 is an exploded perspective view of the check valve of FIG. 1. It is a principal part expanded longitudinal sectional view which shows the attachment state of a disk and an arm. It is an expansion perspective view which shows a rotation prevention member. It is a longitudinal cross-sectional view which shows the intermediate opening state of the disc of the check valve of FIG. It is a longitudinal cross-sectional view which shows the fully open state of the disc of the check valve of FIG. It is a principal part expanded side view which shows the attachment state of a disk.

Hereinafter, embodiments of a check valve according to the present invention will be described in detail with reference to the drawings. In FIG. 1, the longitudinal cross-sectional view of the non-return valve of embodiment of this invention is shown, and the isolation | separation perspective view of the non-return valve of FIG. 1 is shown in FIG.
In the figure, the check valve includes a body 1, a cover 2, a disc 3, an arm 4, an anti-rotation member 5, a holder 6, and a nut 7. The arm 4 is pivotally mounted in the body 1 so as to be swingable. The disc 4 provided on the distal end side of the arm 4 comprises a swing type check valve in which the flow path 1a in the body 1 is provided so as to be freely opened and closed.

  The body 1 has an inflow port 8 and an outflow port 9, and the fluid flows from the inflow port 8 side to the outflow port 9 side by the operation of the disc 3, which will be described later, and from the outflow port 9 side to the inflow port 8 side. Backflow is prevented. An annular valve seat surface 10 is formed in the flow path 1 a between the inflow port 8 and the outflow port 9. The space in the body 1 is provided in such a size that the disc 3 can be operated from the valve closed state to the valve open state, and a restricting portion 11 for restricting the fully open position is formed on the disc 3 opening side.

  An opening 12 is formed in the upper portion of the body 1 so as to communicate with the flow path 1 a, and components can be incorporated into the body 1 through the opening 12. A substantially rectangular parallelepiped mounting portion 13 is formed in the vicinity of the inlet side inside the opening 12 so as to project inward, and two female screws 14 are formed on the upper surface of the mounting portion 13. An annular concave flat portion 15 is formed on the outer periphery on the upper surface side of the opening 12, and a flange portion 16 is provided on the outer periphery of the concave flat portion 15.

  As described above, by disposing the attachment portion 13 near the inlet side of the opening portion 12, when the internal thread 14 is processed, the insertion depth of the tap as a processing tool becomes shallow, and the processing accuracy of the internal thread 14 is improved. Can be increased. Note that the upper surface of the attachment portion 13 may be provided in substantially the same plane as the concave planar portion 15.

  Flange surfaces 17 and 17 are provided on both sides of the body 1, and external piping (not shown) is provided on each flange surface 17 so as to be connectable. A name plate 18 on which a product name, a size, a specification, and the like are written is attached to an appropriate position of the body 1.

  The cover 2 is formed in a substantially disc shape, and an annular convex flat portion 20 that can be fitted to the concave flat portion 15 of the body 1 is formed at the center of the bottom surface. The cover 2 is provided so as to be able to be placed on the flange portion 16 in a state where the gasket 21 is sandwiched between the convex flat portion 20 and the concave flat portion 15, and by screwing all the screw bolts 22 and the hexagon nuts 23 together. The cover 2 and the flange portion 16 are firmly fixed, and the opening 12 is covered with the cover 2.

  In FIG. 1 to FIG. 3, the disk 3 has a substantially disk-shaped disk main body 30 and an attachment shaft portion 31 for attachment to the arm 4, and can rotate to the arm 4 via the attachment shaft portion 31. Mounted on. The disk main body 30 is provided with a larger diameter than the opening area on the primary side of the flow path 1a, and an annular seal surface 32 that can contact and seal the valve seat surface 10 is formed. The mounting shaft portion 31 and an annular flat mounting seat surface 33 are formed on the outer peripheral side of the mounting shaft portion 31.

  The mounting shaft portion 31 is formed so as to protrude from the center on the back side of the disc main body 30, and includes a cylindrical portion 34 and a male screw portion 35 following the cylindrical portion 34. The cylindrical portion 34 is provided with an outer diameter that can be inserted into a mounting hole 36 of the arm 4 to be described later, and is formed to be slightly longer than the thickness near the mounting hole 36 of the arm 4. The male screw part 35 is formed to have a diameter smaller than that of the cylindrical part 34, and a step part 37 is formed between the cylindrical part 34 and the male screw part 35. A through hole 38 is formed at a predetermined position of the male screw portion 35 in a direction perpendicular to the screwing direction.

  The arm 4 is formed in a substantially arc shape and includes a proximal end side and a distal end side. A mounting hole 40 is formed on the base end side of the arm 4 in a direction intersecting with the flow path 1 a, and the base end side is axially mounted in the body 1 through the mounting hole 40. The distal end side of the arm 4 is a disk mounting side, and a flat mounting surface 41 is provided. The mounting hole 36 is formed through the inner peripheral side of the mounting surface 41. The disc 3 is provided on the distal end side of the arm 4 through the mounting hole 36 so as to be attachable.

  The rotation preventing member 5 shown in FIG. 4 is disposed around the mounting shaft portion 31. The rotation preventing member 5 is locked to the arm 4 in the rotation direction of the disk 3, so that the rotating disk 3 has a predetermined angle. Rotation is restricted at.

  The anti-rotation member 5 is made of a washer that can be mounted between the arm 4 and the nut 7 in FIG. The piece 51 and the engaging piece 52 are integrally extended. The locking piece 51 is formed in a substantially L shape with its distal end bent in the direction of attachment to the arm 4, and is provided so as to be locked to the arm 4. The engagement piece 52 is formed by being bent in a direction opposite to the engagement piece 51 at a position facing the engagement piece 51, and is provided so as to be engageable with the side surface of the nut 7. An insertion hole 53 is formed near the center of the engagement piece 52. The engaging piece 52 is not limited to the position facing the locking piece 51, and may be another position or an adjacent position as long as it can engage with the side surface of the nut 7.

  The nut 7 has a female screw portion 55 that is screwed into the male screw portion 35 of the disc 3, and can be fixed to the position of the step portion 37 of the mounting shaft portion 31 when the female screw portion 55 is screwed into the male screw portion 35. It has become. A hole 56 is formed through the nut 7 at a predetermined position in a direction orthogonal to the screwing direction.

  1 to 3, the mounting shaft portion 31 of the disc 3 is inserted into the mounting hole 36 of the arm 4 described above until the cylindrical portion 34 is loosely fitted with the mounting surface 41 and the mounting seat surface 33 facing each other. Is inserted, and the rotation preventing member 5 is mounted from above the mounting shaft portion 31 through the insertion hole 50. At this time, the rotation preventing member 5 is arranged in a direction in which the locking piece 51 is on the disk 3 side and the engaging piece 52 is on the nut 7 mounting side, and the rotation preventing member 5 is interposed in the step portion 37. The female screw portion 55 of the nut 7 is screwed into the male screw portion 35 of the mounting shaft portion 31. In this way, the arm 4 is attached to the attachment shaft portion 31 with the nut 7 via the rotation preventing member (washer) 5.

  After the nut 7 is screwed, the rotation preventing member 5 comes into contact with the step portion 37, and the nut 7 is provided so as to be rotatable integrally with the disc 3 and the nut 7. Thus, the clearance S is provided between the disc 3 and the arm 4 via the stepped portion 37, so that the disc 3 exhibits flexibility with respect to the arm 4 via the clearance S. ing.

  As shown in FIGS. 7A and 7B, the disc 3 rotates counterclockwise or clockwise with respect to the arm 4. At each rotation, the locking piece 51 is attached to the arm 4. The washer 5 functions as an anti-rotation member by engaging with a part of the side surface. From the counterclockwise stop position of the disc 3 in FIG. 7A, the disc 3 in FIG. The rotation of the disk 3 is restricted within a range of a predetermined angle θ as the center P of the disk 3 (mounting shaft portion 31) up to the clockwise stop position.

  At this time, the angle θ of the disc 3 with respect to the arm 4 is larger than the minimum angle when the center P of the disc 3 and both side surfaces of the arm 4 are connected, and 360 ° − (the center P and the arm 4 It is preferable that the angle be smaller than the angle between the contact points of the locking pieces 51 on both side surfaces. Specifically, for example, 10 ° <angle θ <350 ° is preferable, and more preferably, the angle θ is in a range from 90 ° to 270 °. By restricting the rotation of the disk 3 within these ranges, the rotation of the disk 3 can be restricted while ensuring the flexibility of the disk 3.

  Further, the engagement piece 52 is engaged with the side surface of the nut 7 to prevent the rotation prevention member 5 from being displaced relative to the nut 7, and the rotation prevention member 5 rotates together with the nut 7 and the disc 3. ing. A pin (in this embodiment, a split pin) 57 is attached to the engagement piece 52 as a fastening member.

  The split pin 57 shown in FIGS. 2 and 3 is in a state where the insertion hole 53 of the engagement piece 52, the hole 56 of the nut 7 and the through hole 38 of the disc 3 are communicated with each other from the insertion hole 53 side. Inserted. By providing the split pin 57, the nut 6 and the rotation preventing member 5 are integrated through the split pin 57 through the nut 6 and the engagement piece 52, and the nut 7 is prevented from loosening or falling off.

  As described above, the disc member 58 is constituted by the disc 3, the arm 4, the rotation prevention member 5, the nut 7, and the split pin 57, and this disc member 58 is attached in the body 1 through the holder 6.

  As shown in FIG. 2, the holder 6 is formed in a substantially U-shape having a holding part 60 formed so as to hang down on both sides and a connecting part 61 that connects these holding parts 60 at the upper part. The holding portions 60 are provided at intervals that can hold the base end side of the arm 4, and a communication hole 62 for mounting the arm 4 is formed in the lower portion of each holding portion 60. These holding portions 60 are connected and reinforced by rod-shaped reinforcing portions 63 in the vicinity of the middle, and the intervals are maintained. The connecting portion 61 is formed in a size that can be placed on the upper surface of the mounting portion 13 with the holding portions 60 on both sides straddling the mounting portion 13 of the body 1, and corresponds to the female screw 14 of the mounting portion 13. Two holes 64 are provided at the position.

  In the arm 4 described above, in a state where the mounting hole 40 and the communication hole 62 are communicated with each other, a hinge pin 65 is inserted in the lateral direction, and the arm 4 is rotated (swinged) with respect to the holder 6 with the hinge pin 65 as a fulcrum. ) Provided possible. The holder 6 is mounted as a unit by mounting the arm 4 and the disc 3, and the unit is inserted into the body 1 through the opening 12, and the connecting portion 61 is placed on the mounting portion 13. The connecting portion 61 is screwed to the female screw 14 of the mounting portion 13 through a washer 67 by a hexagon socket head bolt 66 through a hole portion 64, and the disk 3 is positioned in the body 1 in the height direction and the flow path direction. Is done. Thus, by fixing the holder 6 to the attachment portion 13, the arm 4 and the disc 3 can be attached while being suspended in the body 1.

  According to the mounting structure of the arm 4 to the body 1, the arm 4 is not pivotally attached from the outside of the body 1 with a hinge pin, so that no other parts such as a plug are used, and a plug insertion that requires high accuracy is required. There is no need to drill holes. Fluid leakage to the outside of the body can be reliably prevented. The mounting portion 13 can be formed integrally with the body 1, and the disk 3 can be disposed at a predetermined position in the body 1 without the need for position adjustment by simply attaching the connecting portion 61 to the mounting portion 13.

  In FIG. 1, after the holder 6 is attached, the center of gravity of the disc member 58 is located on the right side of the axis of the hinge pin 65 after the disc member 58 is installed inside the body 1. In the valve closed state, the disc member 58 tries to rotate clockwise. For this reason, a force acts in a direction in which the annular seal surface 32 of the disc 3 is pressed against the valve seat surface 10, and the annular seal surface 32 and the valve seat surface 10 are tightly sealed, so that from the secondary side of the flow path 1 a. Backflow to the primary side is reliably prevented.

  When the fluid flows from the primary side to the secondary side in the state of FIG. 1, the disc 3 is pressed by the fluid pressure, and the arm 4 swings counterclockwise around the hinge pin 65 as shown in FIG. It becomes a state. Subsequently, at the time of full opening in FIG. 6, the tip end portion of the attachment shaft portion 31 abuts on the restriction portion 11, thereby restricting the fully open position of the disc 3 and preventing further swing of the disc 3 in the valve opening direction. When the flow rate decreases, the disc member 58 reliably swings clockwise around the hinge pin 65 and returns to the valve closed state.

  In the above embodiment, the example in which the rotation preventing member 5 is mounted between the stepped portion 37 and the nut 7 has been described. However, this rotation preventing member is not illustrated, but various positions around the mounting shaft portion 31. The shape can be arbitrarily set.

  For example, the rotation prevention member which has the collar part which bends in the same direction is provided in two places of the opposing position of the peripheral part of a washer, and the step part 37 in the state which arrange | positioned this rotation prevention member to the arm 4 side. It may be mounted as a washer between the nut 7 and the nut 7. In this case, when the disc 3 is rotated, each collar portion is locked to the arm 4 to restrict the rotation of the disc 3. At this time, the restriction angle of the disk 3 is smaller than in the case where the locking piece 51 is provided at one place in the above-described embodiment.

  A washer having a large diameter that reaches the position of the arm 4 may be used, and a tapped hole is provided in the washer, and a bolt that locks the arm 4 is screwed into the tapped hole as a rotation preventing member. Also good. In this case, the bolt can function as the aforementioned locking piece, and the rotation of the disc 3 can be restricted when the bolt is locked to the arm 4.

A locking piece made of a straight collar may be integrally provided on the washer, while a protruding portion may be provided on the arm at a position where the locking piece can be locked. In this case, when the disk 3 is rotated, the rotation of the disk 3 can be restricted by the locking piece being locked to the protruding portion.
In the case of the above example, since the washer can be used as an anti-rotation member, there are no additional parts.

  Further, the rotation of the disc 3 can be restricted by providing a separate locking plate without changing the shape and mounting state of the washer. In this case, for example, a locking plate that can be mounted is provided between the disk 3 and the arm 4, specifically, between the mounting seat surface 33 of the disk 3 and the arm 41, and is provided at the center of the locking plate. A mounting hole having two parallel surfaces is provided, and a locking piece that can be locked to the arm 4 is formed on the outer periphery of the locking plate. On the other hand, on the base end side of the cylindrical portion 34 of the disc 3, a two-surface width portion that can be fitted into the mounting hole is provided. The locking plate is attached to the base end side of the disk cylindrical portion 34, and at the time of mounting, the two-surface width portion is fitted into the mounting hole, thereby locking to the mounting shaft portion between the disk 3 and the arm 4. The board is mounted in a non-rotating state.

  When the disc 3 is rotated, the locking piece of the locking plate is locked to the arm 4 so that the anti-rotation function can be exhibited using this locking plate. As described above, a part other than the washer other than between the arm 4 and the nut 7 can be provided as the rotation preventing member. When the locking plate is provided as the rotation preventing member, the annular washer is processed or shaped. It can be used as it is without any changes.

  As described above, the split pin can also function as an anti-rotation member in addition to using the washer as an anti-rotation member or providing an anti-rotation member different from the washer. In this case, the split pin is bent to the arm 4 side, and the bent portion is locked to the arm 4 to change the shape and mounting state of the annular washer, or to provide a rotation prevention member that is a separate component from the washer. The rotation of the disc 3 can be restricted without providing it.

  Further, in addition to providing a bent portion on the split pin, the other end side of the bent portion is bent in the direction of the nut 7 and engaged with the nut 7 to prevent the split pin from rotating with respect to the nut 7. it can. In this case, the bent portion can be prevented from rotating, and the bent portion can be reliably locked to the arm 4 when the disk 3 is rotated.

  In the above-described embodiment, the nut 7 and the rotation preventing member 5 are integrated by the split pin 57. However, parts other than the split pin 57 can be used as the fastening member, and the shape and the mounting structure are not particular. Absent. Further, the split pin 57 can be omitted.

  Further, although the arm 4 is pivotally mounted in the body 1 via the holder 6, the arm 4 may be directly attached to the body 1 with a hinge pin 65.

Next, the operation of the above embodiment in the check valve of the present invention will be described.
As described above, in the valve closed state of the check valve in FIG. 1, the annular seal surface 32 is in close contact with the valve seat surface 10. In the case of the intermediate opening degree of the disc 3 in FIG. 5, the disc 3 is separated from the valve seat surface 10, and in the fully opened state in FIG. 6, the tip end portion of the mounting shaft portion 31 abuts on the regulating portion 11. It becomes a state.

  In any of the valve closed state, the intermediate opening state, and the fully open state of the disc 3, a force in the rotational direction acts on the disc 3 when fluid pressure is applied to the disc 3. At that time, in the valve closed state, the annular seal surface 32 is crimped to the valve seat surface 10, and in the fully opened state, the attachment shaft portion 31 abuts against the regulating portion 11, so that the discs 3 are not easily rotated by frictional resistance. However, it becomes difficult to regulate the rotation as the fluid pressure increases or fluctuates. On the other hand, when the intermediate opening degree is reached, the disc 3 is easily affected by the fluid pressure due to the disc 3 being separated from the valve seat surface 10 and the regulating portion 11, and the disc 3 is likely to rotate.

  On the other hand, the check valve of the present invention is configured such that the mounting shaft portion 31 of the disc 3 is inserted into the mounting hole 36 of the arm 4 and the rotation preventing member 5 is interposed in the step portion 37 of the mounting shaft portion 31. 7 is screwed to the male screw portion 35, and the rotation preventing member 5 is attached to the distal end side of the arm 4 so as to be rotatable together with the disc 3. At this time, since the mounting surface 41 and the mounting seat surface 33 are opposed to each other, sliding resistance is reduced, and the disc 3 can be rotated with respect to the arm 4 while preventing wear.

  When the disc 3 is rotated, the locking piece 51 is located on the side surface of the arm 4 in the state shown in FIGS. 7A and 7B regardless of whether the valve is closed, in the intermediate opening state, or in the fully open state. The rotation preventing member 5 stops rotating at this position, and the angle θ during rotation of the disk 3 integrated with the rotation preventing member 5 is restricted to a range of less than 360 °.

  Thereby, even if the check valve is used in every situation, free rotation exceeding the limit of the disk 3 can be prevented, and wear and breakage of the disk 3 and the arm 4 can be prevented. The clearance between the disc 3 and the arm 4 can be maintained at a predetermined size, and the deterioration of the flexible performance of the disc 3 is also suppressed. Here, the clearance represents the entire gap generated between the disc 3 and the arm 4 and does not indicate a specific gap.

  Therefore, the function as a check valve can be maintained, and when the valve is closed, a certain play is ensured between the disc 3 and the arm 4, and the annular seal surface 32 is connected to the valve seat surface 10 through this play. It seals with stable adhesiveness while blending in, and exhibits excellent sealing properties.

  On the other hand, when fully opened, rotation of the attachment shaft portion 31 with respect to the restriction portion 11 is prevented to suppress wear of the restriction portion 11 and increase in the opening degree of the disc 3 is prevented. As a result, the swing operation of the disk 3 when the valve is opened is kept within a normal range, and when the fluid from the primary side stops, the disk 3 can reliably return to the valve closed state.

  Further, by providing the engagement piece 52 on the nut 7 side of the rotation preventing member 5 and engaging the engagement piece 52 with the side surface of the nut 7, the rotation of the rotation prevention member 5 with respect to the nut 7 can be prevented. When the disk 3 is about to rotate, the nut 7 integrated with the disk 3 rotates, and the rotation preventing member 5 rotates together with the nut 7, so that the rotation preventing member 5 rotates together with the disk 3. For this reason, the rotation angle of the disc 3 can be reliably regulated to less than 360 ° via the rotation preventing member 5.

  At this time, the rotation preventing member 5 does not directly contact the mounting side of the arm 4 by contacting the stepped portion 37. For this reason, the sliding resistance between the rotation preventing member 5 and the arm 4 can be suppressed through the clearance, and the rotation can be restricted by the locking piece 51 while the disk 3 is smoothly rotated to ensure flexibility. It has become.

  Moreover, by inserting the split pin 57 into the insertion hole 53 of the rotation preventing member 5, the hole portion 56 of the nut 7, and the through hole 38 of the mounting shaft portion 31, the split pin 57 is inserted into the nut 7 and the engagement piece 51. The nut 7 and the rotation preventing member 5 are integrated. Accordingly, the split pins 57 enhance the integrity of the rotation preventing member 5, the nut 7, and the mounting shaft portion 31, and these can be integrally rotated with respect to the arm 4 while preventing the nut 7 from loosening or falling off.

  Since the locking piece 51 and the engaging piece 52 can be integrally formed with the anti-rotation member 5 by bending, the disk 3 and the arm 4 can be used as they are without being processed, and the anti-rotation member 5 is inexpensive by using a washer. Can be formed. The rotation of the disc 3 can be forcibly restricted while maintaining the sealing performance between the disc 3 and the valve seat surface 10 without requiring another part or changing the assembly man-hour and the processing method. The center of gravity of the disc 3 does not change as compared with the case where the disc 3 is processed to have a protrusion or the like so that the rotation preventing function is exerted, so that the operation of the disc swing is also stabilized.

  Since the impact generated in the arm 4 and the disc 3 during the operation of the arm 4 is not directly applied to the nut 7 by being received by the anti-rotation member 5 that is a washer, the loosening, wear, and breakage of the nut 7 due to the impact can be avoided. .

  The embodiment of the present invention has been described in detail above, but the present invention is not limited to the above-described embodiment, and the scope does not depart from the spirit of the invention described in the claims of the present invention. Thus, various changes can be made.

1 Body 3 Disc 4 Arm 5 Washer (Rotation prevention member)
7 Nut 8 Inlet 9 Outlet 31 Mounting Shaft 51 Locking Piece 52 Engaging Piece 57 Split Pin (Pin)

Claims (4)

  An arm pivotally mounted in a body having an outflow inlet, a mounting shaft portion of a disc attached to the arm, and an anti-rotation member disposed around the mounting shaft portion are provided. A non-return valve characterized in that a rotating disc is locked to an arm and is rotated at a predetermined angle.   The said arm is attached to the said mounting shaft part with a nut through a washer, The locking piece extended in this washer was latched by a part of said arm, and it was set as the said rotation prevention member. Check valve.   An engagement piece extends from the washer, the engagement piece is engaged with the nut, and the nut and the washer are integrated through a pin through the nut and the engagement piece. Check valve described in 1.   The check valve according to claim 1, wherein a locking plate is attached to a mounting shaft portion between the disk and the arm in a non-rotating state, and the locking plate is used as the rotation preventing member.

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