JPH09137870A - Check valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a check valve to stabilize the valve opening pressure of a check lip and have the excellent reliability. SOLUTION: A thick-walled base part 16 is provided on a non-return valve body side of a seal lip 15 of an oil seal 1, and on the upstream side of the fluid flowing in the regular direction, a projected part 52 to be pressed against the base part 16 is provided on a flow passage wall 5C opposite to the base part, and a flow passage 16b of the fluid is provided on the base part. Deformation of the base part 16 of the check lip due to the fluid pressure in the regular direction and in the reverse direction thereby, and the valve opening pressure can be stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check valve applied to, for example, a reciprocating sealing device with a check valve mechanism used in a shaft seal portion of a shock absorber, and more particularly to a check valve.

[0002]

2. Description of the Related Art Conventionally, a check lip integrated type check valve is shown in FIG.

FIG. 5 shows the oil seal 100 mounted on the shock absorber 110.

This check valve is provided with a shock absorber 11
Seal lip 1 used for the shaft sealing part of the rod 111 of 0
It is provided integrally with the oil seal 100 provided with 04 and 105, and is provided with the reservoir chamber 118 and the rod guide 1.
The flexible check lip 101 is provided so as to block the flow path 115A that communicates between the seal chamber 119 between the oil seal 15 and the oil seal 100.

The oil seal 100 seals between the outer cylinder 114 and the rod 111, and has a metallic reinforcing ring 103 inside. The main lip 104 and the dust lip 105 are in sealing contact with the rod, and the seal lip is pressed toward the rod 111 by the spring 106. The check lip 101 is provided so as to face the rod guide 115, and has a thick base portion 102 on the reinforcing ring 103 side.

The check lip 101 has a flow path 115.
With respect to the fluid pressure in the positive direction from the seal chamber 119 side to the reservoir chamber 118 side of A, the lip tip is deformed in the direction away from the rod guide 115 as the flow path wall to allow the fluid to flow, and the reservoir chamber With respect to the fluid pressure in the opposite direction from 118 to the seal chamber 119 side, the tip of the lip is the rod guide 1.
The fluid is deformed in the direction pressed by 15 to prevent the fluid from flowing, and the fluid such as oil or gas is allowed to flow in only one direction.

The shaft seal portion of the shock absorber includes an inner cylinder 113 and an outer cylinder 114 which are concentrically assembled with each other.
And a rod guide 115 for guiding the rod. The upper end of the inner cylinder 113 is fixed to the step portion 115B of the rod guide 115, and the outer circumference of the rod guide is the outer cylinder 11.
It is fitted to the inner circumference of 4. A reservoir chamber 118 filled with high-pressure gas or the like is provided between the outer cylinder 114 and the inner cylinder 113, and the rod guide 115 connects the reservoir chamber 118, the oil seal 100, and the seal chamber 119 between the rod guides. A flow channel 115A is provided. A rod 111 is slidably inserted into the inner circumference of the rod guide 115.
5, the piston upper chamber 120 in the inner cylinder 113
And the seal chamber 119 are in communication with each other.

[0008]

However, in the oil seal 100, the check lip 1 including the depth h of the rod guide 115 and the base portion 102 shown in FIG. 6A.
Due to the variation of the height dimension H of 01, the rod guide 11
The force in contact with 5 varies, and as a result, the valve opening pressure at which the check lip opens when fluid pressure is applied in the positive direction varies.

Further, as shown in FIG. 6 (b), the fluid pressure P
_{By o} , the base portion is deformed in the outer diameter direction to generate a locked state, or as shown in FIG. 6C, the fluid pressure P _c causes the base portion to be deformed in the inner diameter direction to cause an inverted state. There was a problem that it would end up. The present invention was made in order to solve the above-mentioned problems of the prior art, and its object is to stabilize the valve opening pressure of the check lip,
It is to provide a check valve having high reliability.

[0010]

SUMMARY OF THE INVENTION A first aspect of the invention comprises a flexible check lip arranged to block a flow path, the check lip being a lip for positive valve opening pressure. The tip is deformed in the direction away from the channel wall to allow the fluid to flow, and the lip tip is deformed in the direction to be pressed by the channel wall against the reverse pressure in the opposite direction to prevent the fluid from flowing. In the check valve, on the check valve main body side of the check lip, on the upstream side of the fluid flowing in the forward direction, a thick base portion is provided, and in the flow path wall facing the base portion, in the base portion. It is characterized in that a pressure-contacting protrusion is provided, and the fluid passage is provided in at least one of the base and the protrusion.

A second aspect of the present invention comprises a flexible check lip arranged so as to block the flow passage, and the tip of the lip extends from the flow passage wall when the check lip has a positive valve opening pressure. In a check valve that deforms in the direction of separating and allows the flow of fluid, and for reverse pressure in the opposite direction, deforms in the direction in which the lip tip is pressed against the flow path wall and blocks the flow of fluid,
On the check valve body side of the check lip, on the downstream side of the fluid flowing in the forward direction, a thick base portion is provided, and between the base portion and the flow path wall facing the base portion, the forward direction is provided. The support portion for supporting the base portion with respect to the valve opening pressure is interposed.

In the check valve according to the first or second aspect of the invention, the check lip is provided integrally with the reciprocating sealing device for shaft-sealing the shock absorber, and is provided on the guide member for guiding the rod of the shock absorber. It may be arranged so as to block the flow path.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a view showing an oil seal as a reciprocating sealing device provided with a check valve according to the present embodiment. Like the prior art, it is provided integrally with the oil seal for shaft sealing of the shock absorber. FIG. 2 shows FIG.
It is the figure which expanded and showed the check lip periphery.

The shaft seal portion of the shock absorber comprises an inner cylinder 2 and an outer cylinder 3 which are concentrically assembled with each other, and a rod 4.
And a rod guide 5 as a guide member for guiding the inner cylinder 2, the upper end of the inner cylinder 2 is fixed to the step portion 5A of the rod guide 5, and the outer circumference of the rod guide 5 is fitted to the inner circumference of the outer cylinder 3. Has been done. A space between the outer cylinder 3 and the inner cylinder 2 is a reservoir chamber 6 filled with high-pressure gas or the like, and the rod guide 5 is connected to the reservoir chamber 6 and a seal chamber 7 between the oil seal and the rod guide. A passage 51 is provided.
A rod 4 is slidably inserted into the inner circumference of the rod guide 5, and a piston upper chamber 8 and a seal chamber 7 in the inner cylinder 2 communicate with each other through a gap between the rod 4 and the rod guide 5. Has been done.

The oil seal 1 generally has an annular seal body 11 fitted on the inner circumference of the outer cylinder 3 and a seal body 11.
Seal lip 12 made of rubber-like elastic material provided on the inner peripheral side
And a check lip 1 made of a rubber-like elastic body that constitutes a check valve provided between the inner circumference of the outer cylinder 3 and the seal lip 12.
5, and the thick base portion 1 provided on the seal body side of the check lip 15 and on the upstream side of the fluid flowing in the positive direction.
6

The seal body 11 is provided with an outer cylinder seal portion 18 which axially projects from the outer peripheral portion of a metal reinforcing ring 17 having a rectangular cross section, and which is fitted into the inner periphery of the outer cylinder 3, and the outer cylinder seal thereof. The outer periphery of the portion 18 extends to and covers the outer peripheral edge of the reinforcing ring 17.

The seal lip 12 is composed of a main lip 13 and a dust lip 14. The main lip 13 extends from the inner end of the reinforcing ring 17 toward the fluid to be sealed in the axial direction, and the main lip tip portion thereof. 13a, 13b
Is in slidable sealing contact with the outer periphery of the rod 4. The rod 4 is attached to the outer periphery of the main lip tips 13a and 13b.
A spring 19 that presses to the side is attached. The rod guide 5 is provided with a step portion 5B which is recessed by the space occupied by the main lip 13. The dust lip extends radially inward from the inner end of the reinforcing ring 17 and faces inward in the radial direction, and the dust lip tip portion 14a slidably seals the outer circumference of the rod 4. The outer periphery of the dust lip 14 extends to the vicinity of the outer periphery of the end surface of the reinforcing ring 17 on the atmosphere side and covers the reinforcing ring 17. This dust lip 1
4 has a role to prevent intrusion of sand and dust.

The check lip 15 constituting the check valve of this embodiment is located on the outer peripheral side of the main lip 13 and extends from the thick base portion 16 provided on the reinforcing ring 17 side toward the fluid to be sealed. It is set up.

The tip 15a of the check lip 15 is adjacent to the step portion 5B of the rod guide 5 serving as a flow path wall 5C.
Is pressed.

Between the stepped portions 5B and 5C of the rod guide 5, there is provided a protruding portion 52 extending toward the axial seal main body side.
It is provided continuously all around. The projecting portion 52 has an inner peripheral portion 52A formed by axially extending the peripheral surface of the rod guide 5 forming the stepped portion 5B, a distal end portion 52B formed in a plane perpendicular to the axial direction, and a rod guide body side. And an outer peripheral portion forming a taper gradually increasing in diameter. It is desirable to form an R shape between the inner peripheral portion 52A and the front end portion 52B and between the front end portion 52B and the outer peripheral portion 52C.

A recess 16a is formed in the end surface 16A of the check lip base 16 on the fluid side to be sealed in the axial direction so that the tip 52B of the protrusion fits into the recess 16a. Is press fitted. End face 16
Although it is possible to press the tip end portion 52B of the protruding portion into A without forming the concave portion, it is more effective to prevent the deformation when the protruding portion 52B and the concave portion 16a are fitted together.

Since the protruding portion 52 is continuously provided over the entire circumference, the fluid flow from the seal chamber 7 is blocked by the base portion 16 and the protruding portion 52. Therefore, as shown by the broken line, the end face 16A of the base portion 16 of the check lip is
A radial groove 16b that connects the inner diameter side and the outer diameter side of the protruding portion 52 is provided as a fluid flow path. The grooves 16b are provided at a plurality of locations in the circumferential direction, but it is desirable to provide the grooves 16b evenly in the circumferential direction.

The check lip 15 has a mechanism in which oil and gas flow only in one direction when the rod 4 reciprocates. That is, the flow from the piston upper chamber 8 to the seal chamber 7 to the flow path 51 to the reservoir chamber 6 is allowed and the flow in the opposite direction is blocked. Specifically, with respect to the fluid pressure in the positive direction, the lip tip 15a is deformed in the direction away from the rod guide 5 as the flow path wall to allow the fluid to flow, and with respect to the fluid pressure in the reverse direction. The lip tip 15a is deformed in the direction in which it is pressed by the rod guide 5 to prevent the fluid from flowing.

The outer circumference of the rod guide 5 is a fitting surface 53 that is fitted to the inner circumference of the outer cylinder 3, and the atmosphere side extends radially inward from the end of the fitting surface 53 toward the atmosphere side. The inclined surface 53a is formed up to the outer peripheral edge of the atmospheric side end surface 54 of the rod guide 5. The other end of the fitting surface extends to the outer peripheral edge of the step portion 5A. Then, the flow path 51 described above penetrates between the outer peripheral end of the step portion 5C and the step portion 5A.

The atmosphere-side end surface 54 of the rod guide 5 abuts the rubber portion 11a between the outer cylinder seal portion 18 and the check lip base portion 16 and the atmosphere-side slant surface 53a has a tip 18a of the outer cylinder seal portion of the oil seal. Abut. Further, the rubber portion 11b baked on the atmosphere side end surface of the reinforcing ring 17 is in contact with the inner peripheral surface of the inward flange portion 31 of the outer cylinder 3. Further, the end surface 55 of the rod guide 5 adjacent to the step portion 5A into which the inner cylinder 2 is fitted faces the piston upper chamber 8.

Oil seal 1 having a check valve of the above construction
Then, in the process of extending the rod 4, the piston upper chamber 8
The fluid inserted into the flow path flows into the seal chamber 7 through the gap between the inner circumference of the rod guide 5 and the outer circumference of the rod 4, and the fluid passes through the groove 16b formed in the end surface 16A of the base portion 16 of the check lip 15. , Check lip tip 15a
By pressing, the check lip 15 is deformed so as to be flipped up to form a gap, and flows into the flow path 51 of the rod guide 5 through the gap and flows into the reservoir chamber 6.

At this time, the base portion 16 of the check lip is
It is pressed to the outer diameter side by the fluid P _O, but is recessed in the base 16
The tip end portion 52B of the protruding portion is press-fitted to a, and deformation in the outer diameter direction is suppressed. Therefore, check lip 1
Locking of 5 is prevented.

On the other hand, when the rod 4 is contracted, the fluid in the reservoir chamber 6 passes through the flow path 51 of the rod guide 5 and exerts a check pressure P _C for pushing the outer peripheral surface 15b of the check lip 15 toward the inner diameter side. . Then the tip 1 of the check lip 15
5a is pressed by the step portion 5C of the rod guide 5 to prevent the backflow of the fluid to the seal chamber 7.

At this time, the base portion 16 of the check lip is pressed toward the inner diameter side by the fluid pressure P _C, but
The tip end portion 52B of the protruding portion is press-fitted to a, and deformation in the inner diameter direction is suppressed. Therefore, check lip 1
Inversion of 5 is prevented.

In this way, the fluid pressure P _o and the fluid pressure P _c
The deformation of the base portion of the check lip due to can be suppressed. Therefore, lock and inversion of the check lip can be prevented.

As in the present embodiment, the rod guide protrusion portion 52 is pressed against the axially sealed fluid-side end surface 16A of the base portion 16 of the check lip, whereby the rod guide 5
The variation in the depth dimension h can be ignored, and only the variation in the height H ′ from the end face of the check lip concave portion 16a to the tip of the check lip causes the variation in the valve opening pressure.

Therefore, the valve opening pressure of the check lip can be stabilized.

In the present embodiment, the protruding portion 52 is continuous over the entire circumference, but it may be provided at a plurality of locations in the circumferential direction.

Further, the groove does not necessarily have to be provided on the base 16 side of the check lip, and a radial groove 52b as shown by a broken line is provided on the projecting portion 52 side so that the inner diameter side and the outer diameter side of the projecting portion 52 are provided. You may make it communicate with.

The shape of the protruding portion of the rod guide is not limited to that shown in FIGS. 1 and 2, but as shown in FIG.
The protruding portion 52 'may be formed in a tapered shape so that the step portion 5C protrudes toward the atmosphere side toward the inner diameter side. In this case, the tip portion 52'a of the protruding portion has an R shape, and the recess 16 provided in the base portion 16 'of the check lip is provided.
You may make it press-fit to ‘a. When the rod guide is press-molded, the protrusion having such a shape is more suitable. Also in this case, the base portion 16 ′ and the protruding portion 5
As shown by the broken line on at least one of 2 ',
A radial groove 16'b or 52'b is provided on the inner diameter side and the outer diameter side of the protruding portion 52 'for allowing the fluid to flow therethrough. Groove 16
It is desirable that ′ b or 52′b be evenly provided in the circumferential direction.

Also in this case, similarly, the fluid pressure P _o and the fluid pressure P
The deformation of the base of the check lip due to _c can be suppressed, and the lock and inversion of the check lip can be prevented.

Further, variations in the depth dimension h of the rod guide 5 can be neglected, and the recess 16 of the check lip can be ignored.
Similarly, only the variation in the height H'from the end face of a'to the tip of the check lip causes the variation in the valve opening pressure.

Therefore, the valve opening pressure of the check lip can be stabilized even if the protrusion has such a shape.

In the present embodiment, the check valve provided integrally with the sealing device for the shaft seal of the shock absorber has been described, but the check valve is not limited to the shock absorber, and a check lip is used to supply fluid. It can be used as a check valve that allows circulation in one direction.

(Second Embodiment) FIG. 4 shows a check valve according to a second embodiment.

The check valve according to the present embodiment is integrally provided with the oil seal 20 for sealing the shaft of the shock absorber, as in the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description is omitted.

The seal body 21 is fitted on the inner peripheral surface 54 of the rod guide 5. An outer peripheral seal portion 22 that covers the reinforcing ring is provided on the outer periphery of the seal body, and is in contact with the inner peripheral surface 54 of the rod guide 5. The fluid to be sealed side of the reinforcing ring is exposed on the outer diameter side, and the exposed portion 17a is in contact with the step portion 5D of the rod guide 5.
Further, a protrusion 21 a protruding toward the atmosphere is provided on the outer diameter side of the rubber portion 11 a burned on the atmosphere side end surface of the reinforcing ring 17, and the protrusion 21 a is the inner circumference of the inward flange portion 31 of the outer cylinder 3. Pressed against the surface.

The base portion 26 of the check lip 15 according to this embodiment is provided on the outer diameter side, that is, on the downstream side of the fluid flowing in the forward direction. Further, as a support portion, a protrusion 27 that comes into contact with the inner peripheral surface 55 adjacent to the step portion 5C of the rod guide 5 is provided from the base portion 26 toward the outer diameter side. It is desirable that the protrusions 27 are evenly provided at a plurality of locations in the circumferential direction.

In the expansion process of the rod (not shown), the fluid inserted in the piston upper chamber 8 flows into the seal chamber 7 through the gap between the inner circumference of the rod guide 5 and the outer circumference of the rod, and presses the check lip 15. As a result, the distal end portion 15a is deformed so as to be flipped up to form a gap, and flows through the gap into the flow path 51 of the rod guide 5 and into the reservoir chamber 6.

At this time, the base portion 26 of the check lip is pressed to the outer diameter side by the fluid pressure P _o .
Since the projection 27 is interposed between the rod guide and the inner peripheral surface 55, the deformation in the outer radial direction is suppressed.

Therefore, by providing such a protrusion 27, even if the fluid pressure P _{o in} the positive direction becomes high, the deformation of the base portion 26 of the check lip can be suppressed, and the check lip is prevented from locking. It is possible to stabilize the valve opening pressure.

In this embodiment, a plurality of protrusions 27 are provided as a supporting portion in the circumferential direction so as to come into contact with the inner peripheral surface 55 of the rod guide. However, they are provided so as to be in pressure contact over the entire circumference. Good.

In this embodiment, the check valve provided integrally with the sealing device for sealing the shaft of the shock absorber has been described. However, the check valve is not limited to the shock absorber, and a check lip is used to supply fluid. It can be used as a check valve that allows circulation in one direction.

[0049]

According to the first aspect of the present invention, a thick base is provided on the check valve body side of the check lip on the upstream side of the fluid flowing in the forward direction, and the flow path wall facing the base is provided. In addition, since the protruding portion is provided in pressure contact with the base portion and the fluid passage is provided in at least one of the base portion and the protruding portion, deformation of the base portion of the check lip due to fluid pressure in the forward direction and the reverse direction is suppressed, and the check lip is suppressed. Since it is possible to prevent reversal and locking of the check valve, it is possible to stabilize the valve opening pressure of the check lip.

According to the second aspect of the invention, a thick base is provided on the check valve body side of the check lip on the downstream side of the fluid flowing in the forward direction, and the base and the flow path wall facing the base are provided. Since a support part for supporting the base part against the valve opening pressure in the positive direction is interposed between and, the deformation of the base part of the check lip due to the fluid pressure in the positive direction is suppressed, and the check lip is prevented from locking. Therefore, the valve opening pressure of the check lip can be stabilized.

In the check valve according to the first or second aspect of the present invention, the check lip is provided integrally with the reciprocating sealing device for shaft sealing of the shock absorber, and is provided with the guide member for guiding the rod of the shock absorber. By arranging such a flow path so as to be blocked, it is possible to stabilize the quality and improve the function of the shock absorber.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a check valve according to a first embodiment.

FIG. 2 is a view showing the vicinity of a check lip of the check valve according to the first embodiment.

FIG. 3 is a view showing the vicinity of a check lip of the check valve according to the first embodiment.

FIG. 4 is a diagram showing a schematic configuration of a check valve according to a second embodiment.

FIG. 5 is a diagram showing a schematic configuration of a conventional check valve.

FIG. 6 (a) is a diagram showing the vicinity of a check lip of a conventional check valve. FIG. 6B is a diagram for explaining the lock phenomenon of the check lip of the conventional check valve. FIG.
(C) is a figure explaining the reversal phenomenon of the check lip of the conventional check valve.

[Explanation of symbols]

 1 Oil Seal 5 Rod Guide 11 Seal Main Body 15 Check Lip 16 Base 52 Projection 16b Groove 27 Projection

Claims (3)

[Claims] 1. A flexible check lip arranged so as to block a flow passage, the check lip being in a direction in which the lip tip is separated from a flow passage wall in response to a positive valve opening pressure. A check valve that deforms to allow the flow of fluid and deforms in the direction in which the lip tip is pressed against the flow path wall against reverse pressure in the opposite direction to prevent the flow of fluid. A thick base portion is provided on the stop valve main body side on the upstream side of the fluid flowing in the forward direction, and a flow passage wall facing the base portion is provided with a protruding portion that comes into pressure contact with the base portion. A check valve, wherein a flow path for the fluid is provided in at least one of the protrusions. 2. A flexible check lip arranged so as to block the flow passage, wherein the check lip is arranged in a direction in which the lip tip is separated from the flow passage wall in response to a positive valve opening pressure. A check valve that deforms to allow the flow of fluid and deforms in the direction in which the lip tip is pressed against the flow path wall against reverse pressure in the opposite direction to prevent the flow of fluid. A thick base portion is provided on the stop valve main body side, downstream of the fluid flowing in the forward direction, and a valve opening pressure in the forward direction is provided between the base portion and the flow path wall facing the base portion. On the other hand, a check valve characterized by interposing a support portion for supporting the base portion. 3. A check lip is provided integrally with a reciprocating sealing device for shaft-sealing a shock absorber, and is arranged so as to block a flow path provided in a guide member for guiding a rod of the shock absorber. The check valve according to claim 1 or 2, characterized in that.