JPH0545332U - Check valve - Google Patents

Abstract

(57) [Abstract] [Purpose] It facilitates the setting that satisfies both the valve opening pressure and the stopping force for the fluid pressure in the forward and reverse directions of the check lip.
Improve performance. A valve body 91 having a volume is formed at the tip of the check lip 9, and the valve body 91 and one member 1 are connected by a thin flexible member 92. The valve opening pressure can be set by a thin flexible member 92, and the stopping force against the fluid pressure in the opposite direction can be set by combining the size of the valve body portion 91 and the throttle portion 12 with each other. Part 91
The feature is that it can be set depending on the material.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 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 hydraulic shock absorber, and more particularly to a check valve having a check lip.

[0002]

[Prior Art]

 Conventional check valves having this type of check lip include, for example, those shown in FIGS. 3 and 4. That is, the check valve is integrally provided on the reciprocating oil seal 102 provided with the seal lip 101 used for the shaft sealing portion of the rod 100 of the hydraulic shock absorber, and includes the reservoir chamber 103 and the guide member. The flexible check lip 107 is provided so as to block the communication passage 106 that communicates between the seal chamber 105 between the oil seal 102 and the oil seal 102.

The check lip 107 has a rectangular cross section that is inclined with respect to the guide member 104, and the tip of the lip serves as a flow path wall against a positive fluid pressure from the seal chamber 105 side of the communication passage 106 to the reservoir chamber 103 side. The communication passage 106 opens apart from the guide member 104 of the above, and the tip of the lip presses the guide member 104 against the fluid pressure in the reverse direction from the reservoir chamber 103 to the seal chamber 105 side. It is designed to stop the flow of fluid such as oil and gas in one direction.

[0004]

[Problems to be solved by the device]

 However, in the case of the above-mentioned conventional technique, when the fluid pressure in the forward direction is low, the wall thickness of the check lip 107 provided on the oil seal 102 is reduced or the material is softened to make it easier to bend. There must be. In this case, since the check lip 107 is easily bent, the restraining force against the fluid pressure in the opposite direction becomes small.

On the contrary, in order to increase the restraining force against the fluid pressure in the opposite direction, it is necessary to increase the wall thickness of the check clip 107 or harden the material to make it difficult to bend. Even if the fluid pressure in the direction acts on the check lip 107, it becomes difficult to open the valve.

Therefore, it is difficult to set the check lip 107 that satisfies both the valve opening pressure and the stopping force with respect to the forward and reverse fluid pressures.

The present invention was made in order to solve the above-mentioned problems of the prior art, and an object of the present invention is to satisfy both the valve opening pressure and the stopping force with respect to the fluid pressure in the forward and reverse directions of the check lip. The purpose of the present invention is to provide a non-return valve that can be easily set and the performance can be improved.

[0008]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, in the present invention, a flexible check lip is provided so as to block the flow path, and the check lip has a lip tip with respect to a positive fluid pressure. A check valve that opens the flow path away from the flow path wall and closes the flow path by pressing the tip of the lip against the flow path wall against the fluid pressure in the opposite direction. The valve body is provided in close contact with the flow passage wall by the elasticity of the check lip, while the flow passage is provided with a throttle portion that is closed by the valve body when the fluid pressure acts in the opposite direction. The valve opening pressure with respect to the pressure can be set by the check clip, and the maximum check pressure for the fluid pressure in the opposite direction can be set by the combination of the valve body portion and the throttle portion.

[0009]

[Action]

 In the check valve having the above-described configuration, the check valve is bent with respect to the fluid pressure in the positive direction, so that the valve body portion is separated from the flow path wall and opens. Therefore, the valve opening pressure can be set depending on the thickness of the check lip and the material.

Further, with respect to the fluid pressure in the opposite direction, the valve body portion is pressed by the fluid pressure toward the throttle portion side provided in the flow path to close the throttle portion. Therefore, the stopping force against the fluid pressure in the opposite direction can be set by the combination of the valve body portion and the throttle portion, for example, the volume of the valve body portion and the size and material of the throttle portion.

As described above, the valve opening with respect to the fluid pressure in the forward direction and the valve closing with respect to the fluid pressure in the opposite direction, that is, the restraint against the fluid pressure in the opposite direction are functionally separated. Therefore, since each setting can be freely set, it becomes easy to set both the valve opening pressure and the blocking force against the fluid pressure in the forward and reverse directions of the check lip, and the check valve performance can be improved. ..

[0012]

【Example】

 The present invention will be described below based on the illustrated embodiment. 1 and 2 show a check valve according to an embodiment of the present invention, and in this embodiment as well as in the conventional example, the check valve is provided integrally with an oil seal 1 for shaft sealing of a hydraulic shock absorber. The case is explained as an example.

The shaft seal portion of the hydraulic shock absorber is composed of an outer cylinder 2 and an inner cylinder 3 that are concentrically assembled with each other, and a guide member 5 that guides the rod 4, and the upper end of the inner cylinder 3 is The guide member 5 is fixed to the step portion 51 of the guide member 5, and the outer periphery of the guide member 5 is fitted to the inner periphery of the outer cylinder 2. A space between the outer cylinder 2 and the inner cylinder 3 is a reservoir chamber B filled with high-pressure gas or the like, and the guide member 5 includes a reservoir chamber B, an oil seal 1, and a guide member 5 between them. A communication hole 52 that communicates with the seal chamber C is provided. A rod 4 is slidably inserted into the inner circumference of the guide member 5 via a sleeve 6, and a seal is formed between the upper piston chamber D in the inner cylinder 3 and the seal through a gap between the rod 4 and the sleeve 6. The rooms C communicate with each other.

The oil seal 1 generally comprises an annular seal body 7 fitted to the inner circumference of the outer cylinder 2, and a check valve provided between the inner circumference of the outer cylinder 2 and the seal lip 8. And a check lip 9 made of a rubber-like elastic material.

The seal body 7 is composed of a rubber-like elastic body 71 that projects axially toward the atmosphere side A from the atmosphere side end surface of the outer periphery of the metal reinforcing ring 10 having a rectangular cross section. Then, the contact surface 53 of the guide member 5 contacts the end surface of the reinforcing ring 10, and the rubber-like elastic body 71 is fixed by caulking or the like at the opening end portion 21 of the outer cylinder 2, whereby the oil seal 1 is fixed. There is.

The seal lip 8 is composed of a main seal lip 81 and a sub seal lip 82. The main seal lip 81 extends from the inner end of the reinforcing ring 10 to the seal chamber C side and its main The seal lip tip portion 81a slidably and sealingly contacts the outer periphery of the rod 4. On the outer circumference of the main seal lip tip portion 81a, a spring 11 that presses the rod 4 side is mounted.

The sub-seal lip 82 extends from the inner end of the reinforcing ring 10 to the atmosphere side A and is directed inward in the radial direction, and the sub-seal lip tip 82 a is slidably sealed on the outer circumference of the rod 4. Are in contact. The sub seal lip 82 has a function of preventing intrusion of sand and dust.

On the other hand, the check lip 9 which constitutes the check valve of the present invention is a cross section which is continuously baked from the outer periphery of the main seal lip 81 in the middle part of the reinforcing ring 10 and protrudes toward the axial guide member 5 side. The rubber-like elastic body 83 having a substantially trapezoidal shape is integrally provided.

Further, the rubber-like elastic body 83 having a substantially trapezoidal cross section and the step portion 54 of the guide member 5 form the flow passage 12 as a narrowed portion between the seal chamber C and the communication hole 52 of the guide member 5. Has been done. The flow passage 12 includes a small flow passage 12a having a narrow gap between the axial end surface 83a of the rubber-like elastic body 83 and the end surface 54a of the step portion 54 of the guide member 5, and the outer cylinder 2 side of the rubber-like elastic body 83. A narrowed portion is formed by the large flow path 12b having a wide space between the inclined surface 83b and the outer peripheral wall 54b of the step portion 54 of the guide member 5.

The check lip 9 is composed of a valve body portion 91 having a circular cross section with a volume at the tip of the lip, and a thin rubber flexible member 92 connecting the valve body portion 91 and the rubber elastic body 83. It is configured. Specifically, the rubber-like flexible member 92 extends obliquely from the corner of the end face 83a of the rubber-like elastic body 83 on the outer cylinder 2 side to the step portion 54, and has a circular disc-shaped valve body portion continuous to the tip thereof. 91 is provided, is located on the large flow path 12b side, and is in contact with the end surface 54a of the step portion 54. The cross-sectional area of the valve body 91 is larger than the width of the small flow passage 12a and smaller than the width of the large flow passage 12b.

The check lip 9 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 D → the seal chamber C → the flow path 12 → the communication hole 52 → the reservoir chamber B is allowed and the flow in the opposite direction is stopped. Specifically, the valve body 91 is pressed against the fluid pressure in the forward direction, and the thin rubber-like flexible member 92 bends to separate from the end surface 54a of the guide member 5 as the flow path wall. When the valve body is opened and the valve body 91 is pressed against the fluid pressure in the opposite direction, the cross-sectional area of the valve body 91 is smaller than the small flow passage 12a between the rubber elastic body 83 and the stepped portion 54 of the guide member 5. Since it is large, the small flow path 12a is clogged to suppress the fluid pressure. Further, at this time, if the valve body 91 is made of a soft material and the check pressure becomes large, the valve body 91 may escape to the seal chamber C side, so a hard material is preferable.

Next, the operation of the oil seal equipped with the check valve will be described. The fluid introduced into the piston upper chamber D during the expansion process of the rod 4 inserted into the inner cylinder 3 flows into the seal chamber C through the gap between the inner periphery of the sleeve 6 and the outer periphery of the rod 4, and The fluid presses the valve body portion 91 of the check lip 9 through the small flow path 12a including the end surface 83a of the rubber-like elastic body 83 and the end surface 54a of the step portion 54 of the guide member 5, thereby forming a thin rubber shape. The flexible member 92 bends and the valve body 91 is opened apart from the end surface 54a of the step 54 of the guide member 5, and the fluid is opened by the slope 83b of the rubber-like elastic body 83 and the outer periphery of the step 54 of the guide member 5. It flows into the large flow path 12b including the wall 54b, and then flows into the reservoir chamber B through the communication hole 52 of the guide member 5. Therefore, the valve opening is performed by bending the thin rubber-like flexible member 92.

On the other hand, in the step of contracting the rod 4, a check pressure is applied to the fluid in the reservoir chamber B to the check lip 9 via the communication hole 52 of the guide member 5. At that time, since the cross-sectional area of the valve body portion 91 at the lip end portion of the check lip 9 is larger than the small flow passage 12a formed by the end surface 83a of the rubber-like elastic body 83 and the end surface 54a of the step portion 54 of the guide member 5, a small flow is generated. Pressed by the passage 12a, the small passage 12a is clogged by the valve body portion 91 to prevent the reverse flow of the fluid to the seal chamber C. Therefore, the stop is also performed by the combination of the size of the cross-sectional area of the valve body portion 91 and the size of the small flow passage 12a of the throttle portion and the material of the valve body portion 91.

As described above, the valve opening for the fluid pressure in the forward direction and the control for the fluid pressure in the reverse direction are functionally separated.

In the oil seal with the check valve having the above-described structure, the valve is opened to the fluid pressure in the positive direction by bending the thin rubber flexible member 92 of the check lip 9. Therefore, the valve opening pressure with respect to the fluid pressure in the positive direction can be set depending on the thickness of the rubber-like flexible member 92 or the material thereof.

On the other hand, the control against the fluid pressure in the opposite direction is achieved by combining the size of the cross-sectional area of the valve body portion 91 of the check lip 9 and the size of the small flow passage 12a of the throttle portion and the material of the valve body portion 91. The maximum check pressure can be set depending on the combination and the material of the valve body 91.

Further, since the valve opening for the fluid pressure in the positive direction and the restriction for the fluid pressure in the opposite direction are functionally separated, each setting can be freely set. For example, when the fluid pressure in the positive direction is low, the thickness of the rubber-like flexible member 92 of the check lip 9 is reduced or softened so that the check lip 9 is easily bent. On the other hand, the stopping force against the fluid pressure in the opposite direction is set separately by the valve body portion 91 of the check lip 9 and the small flow passage 12b of the throttle portion, so that the check lip 9 is easily bent as in the prior art. As a result, the stopping force does not become small, and it is possible to easily set both the valve opening pressure and the stopping force for the fluid pressure in the forward and reverse directions.

Therefore, the specification can be easily set, and the performance of the check valve can be improved.

In the above-described embodiment, the cross-sectional shape of the valve body 91 of the check lip 9 is described as a circular shape, but the shape is not particularly limited, and the valve body 91 is a small flow passage of the throttle portion at the time of check pressure. Any shape may be used as long as it can fit in 12b.

Further, in this embodiment, the example in which the check valve is integrally provided in the sealing device for the shaft seal of the shock absorber has been described, but the present invention is not limited to the shock absorber and, in short, a check lip is used. Of course, it can be widely used as a check valve for checking the fluid.

[0031]

[Effect of the device]

 The present invention has the above-described configuration and action, and is configured so that the valve body is formed at the tip of the check lip and the flow passage is closed by the valve body against the fluid pressure in the opposite direction. The valve opening pressure against the fluid pressure in the forward direction can be set by the check lip, and the stopping force against the fluid pressure in the reverse direction can be determined by the size of the valve body, the size of the flow path, the material of the valve body, It can be set by a combination of. Since the valve opening pressure and the check pressure can be set freely in this way, it becomes easy to set both the valve opening pressure and the blocking force for the fluid pressure in the forward and reverse directions, and the check valve performance can be improved. Can be achieved.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part of an oil seal provided with a check valve according to an embodiment of the present invention in use.

FIG. 2 is an enlarged vertical sectional view of an essential part of a check lip of the oil seal of FIG.

FIG. 3 is a vertical cross-sectional view of a main part of a conventional oil seal provided with a check valve in use.

FIG. 4 is an enlarged vertical sectional view of a main part of a check lip of the oil seal of FIG.

[Explanation of symbols]

 1 Oil Seal 2 Outer Cylinder 21 Open End 3 Inner Cylinder 4 Rod 5 Guide Member 51 Stepped Part 52 Communication Hole 53 Abutment Surface 54 Step 54a End Face 54b Outer Wall 6 Sleeve 7 Seal Body 71 Rubber Elastic Body 8 Seal Lip 81 Main seal lip 81a Main seal lip tip portion 82 Sub seal lip 82a Sub seal lip tip portion 83 Rubber elastic body 83a End face 83b Slope 9 Check lip 91 Valve body portion 92 Rubber flexible member 10 Reinforcement ring 11 Spring 12 Flow path 12a Small channel 12b Large channel A Atmosphere side B Reservoir chamber C Seal chamber D Piston upper chamber

Claims (1)

[Scope of utility model registration request] 1. A flexible check lip is provided so as to block the flow passage, and the check lip opens the flow passage by separating the tip of the lip from the flow passage wall in response to a positive fluid pressure. A check valve that closes the flow passage by pressing the tip of the lip against the flow passage wall against the fluid pressure in the opposite direction, wherein the check lip tip is in close contact with the flow passage wall by the elasticity of the check lip. A body part is provided, while a throttle part that is closed by the valve body part when the fluid pressure in the opposite direction is applied is provided in the flow passage, and the valve opening pressure for the positive direction fluid pressure can be set by the check lip. The check valve is characterized in that the maximum check pressure for making the fluid pressure in the opposite direction can be set by the combination of the valve body portion and the throttle portion.