JP2018155395A - Sealing device for hydraulic damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device for a hydraulic damper which can lower the valve-opening pressure of a check lip.SOLUTION: A double-cylinder type sealing device 10 for a hydraulic damper comprises: an inner cylinder; an outer cylinder 3 covering the inner cylinder; a piston rod 4 which is arranged in the inner cylinder so as to be movable to an axial O-direction; and a rod guide 5 for blocking opening ends 3a of the inner cylinder and the outer cylinder 3, and pivotally supporting the piston rod 4. The sealing device 10 for the hydraulic damper also comprises a metal ring 11 which is arranged at a side opposite to the opening end of the inner cylinder of the rod guide 5, and an annular check lip 15 which is arranged at a side opposite to the rod guide 5 of the metal ring 11 so as to abut on the rod guide 5, and permits only a flow of fluid progressing toward a reservoir chamber which is formed between the inner cylinder and the outer cylinder 3 from a space between the rod guide 5 and the metal ring 11. The check lip 15 is composed of a plurality of lip pieces 16 in a peripheral direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sealing device for a hydraulic shock absorber.

  Generally, a vehicle such as an automobile is provided with a hydraulic shock absorber for each wheel in order to suppress vibration during traveling. Hydraulic shock absorbers are roughly classified into single-cylinder types and double-cylinder types, and particularly, double-cylinder type hydraulic shock absorbers are used in many ordinary vehicles because of their simple structure and reduced manufacturing costs.

A multi-cylinder hydraulic shock absorber generally includes an inner cylinder, an outer cylinder that covers the inner cylinder, a piston positioned in the inner cylinder, a piston joined to one end, and the other end that is external to the opening end of the inner cylinder. A piston rod is provided so as to protrude in the direction. The piston rod is slidably supported with respect to the rod guide by a rod guide that closes the open end of the inner cylinder, whereby the piston rod is provided in the inner cylinder so as to be movable in the axial direction. Yes.
The inner and outer cylinders are filled with hydraulic oil. When the piston rod slides against the rod guide, the hydraulic oil can flow out from the sliding surface of the piston rod and rod guide. There is sex. In order to suppress the outflow of the hydraulic oil, a sealing device that seals the outer periphery of the piston rod is provided.

For example, Patent Document 1 discloses a sealing device for a hydraulic shock absorber as shown in FIG. FIG. 15 is a half cross-sectional view showing the sealing device 101 cut along a plane passing through the axis O together with a part of the double cylinder type hydraulic shock absorber 100.
The sealing device 101 includes a flat washer-shaped metal ring 102, a main lip 103 and a check lip 104 that are integrally formed on the metal ring 102 with rubber or a synthetic resin having rubber-like elasticity.

The main lip 103 extends from the inside of the metal ring 102 toward the inside of the hydraulic shock absorber 100 and is in close contact with the outer peripheral surface of the piston rod 105 so as to be slidable.
In the direction in which the piston rod 105 protrudes outward, that is, in the axial movement in the upward direction in FIG. 15, the piston of the oil chamber S <b> 1 inside the inner cylinder 106 is moved by the movement of the piston (not shown) integral therewith. Since the volume of the portion located higher is reduced, a part of the hydraulic oil in the oil chamber S1 passes through the gap G between the inner peripheral surface of the rod guide 107 and the outer peripheral surface of the piston rod 105, and the main lip 103 is accommodated, and flows into the main lip chamber S3 partitioned on the outer peripheral side by a check lip 104 described later. The main lip 103 prevents the hydraulic oil in the oil chamber S1 flowing into the main lip chamber S3 from leaking to the outside.

The check lip 104 is provided on the outer peripheral side of the main lip 103, extends in a tapered shape that opens to the outer peripheral side, and a tip end portion thereof is in close contact with the valve seat surface 107 b of the rod guide 107 so as to be able to contact and separate.
As described above, when the hydraulic oil flows into the main lip chamber S3 and the pressure of the hydraulic oil in the main lip chamber S3 increases and becomes higher than the pressure in the open chamber S4 on the outer peripheral side of the check lip 104, the differential pressure As a result, the check lip 104 is opened and opened away from the valve seat surface 107b of the rod guide 107, and the hydraulic oil in the main lip chamber S3 is stored in the reservoir through the communication hole 107d provided in the rod guide 107 from the open chamber S4. Flows to chamber S2. In this way, the hydraulic oil flowing into the main lip chamber S3 is returned to the reservoir chamber S2.

  On the other hand, if the gas or hydraulic oil in the reservoir chamber S2 flows back to the main lip chamber S3 via the open chamber S4, the hydraulic shock absorber 100 may malfunction or generate abnormal noise. The check lip 104 is provided to suppress this. That is, when the gas or hydraulic oil is going to flow backward, the pressure in the open chamber S4 becomes higher than the pressure in the main lip chamber S3 and becomes a reverse pressure. Is pressed against the valve seat surface 107b. Thereby, the backflow of the gas and hydraulic oil in reservoir chamber S2 to main lip chamber S3 can be suppressed.

As described above, when the check lip 104 is provided in the sealing device 101, if the rigidity of the check lip 104 is high, the valve opening pressure, which is the pressure required to open the check lip 104, increases. Then, since the pressure in the main lip chamber S3 increases to the valve opening pressure, the pressing force of the main lip 103 against the piston rod 105 increases, and the frictional resistance when the piston rod 105 slides increases, so the ride comfort is impaired. May be. Therefore, it is necessary to reduce the valve opening pressure of the check lip 104 as much as possible.
A simple method for reducing the valve opening pressure is to reduce the rigidity and tightening allowance of the check lip 104.

However, in the method as described above, at the same time, the check lip 104 is easily reversed to the inner peripheral side at the time of back pressure due to the pressure in the reservoir chamber S2 (open chamber S4) rising.
In the sealing device 101 of Patent Document 1, a required number of concave portions 104c are formed at positions appropriately separated from the lip tip portion of the surface facing the opposite side of the valve seat surface 107b, so that the check lip 104 of the check lip 104 is reversely pressurized. The valve opening pressure is lowered while suppressing reversal.

  Patent Document 2 discloses a check seal structure in which a protrusion that contacts the rod guide is provided at the tip of the check seal, and a step portion that engages with the protrusion of the check seal is provided on the rod guide. Thereby, the return of the check seal to the inner peripheral side is restricted.

JP 2009-191992 A JP 2008-291959 A

  In recent years, vehicles such as automobiles have been required to further improve riding comfort. That is, in the hydraulic shock absorber sealing device, further improvement is required to lower the check lip valve opening pressure to lower the pressure in the main lip chamber and lower the frictional resistance when the piston rod slides. ing.

  The problem to be solved by the present invention is to provide a sealing device for a hydraulic shock absorber capable of reducing the valve opening pressure of the check lip.

The present invention employs the following means in order to solve the above problems. That is, the present invention is a double cylinder type hydraulic shock absorber sealing device, wherein the hydraulic shock absorber is provided in an inner cylinder, an outer cylinder covering the inner cylinder, and an axially movable inner cylinder. A piston guide, and a rod guide for closing the opening ends of the inner cylinder and the outer cylinder and pivotally supporting the piston rod, the rod guide on the opposite side of the opening end of the inner cylinder. A metal ring provided on a side of the metal ring facing the rod guide so as to come into contact with the rod guide; and a space between the rod guide and the metal ring from the inner cylinder and the outer ring. Provided is a sealing device for a hydraulic shock absorber having an annular check lip that allows only a fluid flow toward a reservoir chamber formed between the cylinder and the check lip, which is composed of a plurality of lip pieces in the circumferential direction. To do.
According to the configuration as described above, the check lip is provided on the side of the metal ring facing the rod guide so as to contact the rod guide. Are divided into a space on the inner peripheral side of the lip and a space on the outer peripheral side of the check lip. In addition, the check lip is composed of a plurality of lip pieces in the circumferential direction. Compared to a case where the check lip is integrally formed in the circumferential direction, the check lip is partially changed, for example, when a certain lip piece is deformed. Since the influence of tension, which tries to keep the shape of the check lip from the lip piece in a steady state, is suppressed, the check lip is easily deformed. That is, when a fluid such as hydraulic oil flows into the inner circumferential space and the pressure in the inner circumferential space rises and becomes higher than the pressure in the outer circumferential space, the increased inner circumferential space Each lip piece is easily deformed by the internal pressure, and the fluid in the inner circumferential space flows easily to the reservoir chamber through the outer circumferential space. Therefore, it is possible to effectively reduce the valve opening pressure of the check lip.

In one aspect of the present invention, the rod guide includes an annular projecting portion that projects to the side facing the metal ring, and the check lip contacts the outer peripheral surface of the projecting portion, The plurality of lip pieces are formed by cutting from the tip toward the base at a plurality of positions.
According to the above configuration, the check lip is cut from the tip toward the base at a plurality of positions in the circumferential direction to form a plurality of lip pieces, so that the check lip operates in the inner space. When fluid such as oil flows in and the pressure in the inner space rises and becomes higher than the pressure in the outer space, the notch between the lip pieces is increased by the increased pressure in the inner space. By opening, the fluid in the inner space can easily flow to the reservoir chamber through the outer space. Therefore, it is possible to effectively reduce the valve opening pressure of the check lip.
In addition, the rod guide has an annular projecting portion that projects to the side facing the metal ring, and the check lip is in contact with the outer peripheral surface of the projecting portion, so that the pressure in the outer circumferential space is When the pressure is higher than the pressure in the space on the side and becomes a reverse pressure, each lip piece is pressed against the outer peripheral surface of the protrusion by the pressure in the outer space, so that the inner space and the outer space are Partition. Therefore, it is possible to effectively suppress the backflow of fluid such as hydraulic oil or gas at the time of reverse pressure.

In another aspect of the present invention, the lip piece has, at one end in the circumferential direction, an extending portion that extends to the outer peripheral side of the other lip piece adjacent to the one end side and overlaps with the other lip piece. The extending portion is formed thinner than the overlapping portion of the other lip piece.
According to the above configuration, the extending part of the lip piece that overlaps with the other adjacent lip piece is formed thinner than the overlapping part of the other lip piece. When a fluid such as hydraulic oil flows into the space and the pressure in the inner circumferential space rises and becomes higher than the pressure in the outer circumferential space, the thinly formed extending portion rises on the inner circumferential side. It is easily deformed so as to bend toward the outer peripheral side by the pressure in the space, and a gap is formed between the adjacent lip pieces, so that the fluid in the inner peripheral space passes through this gap and the outer peripheral space, It has a structure that easily flows into the reservoir chamber. Therefore, it is possible to effectively reduce the valve opening pressure of the check lip.
In addition, since the stretched portion extends and overlaps the outer peripheral side of other adjacent lip pieces, the pressure in the outer peripheral space becomes higher than the pressure in the inner peripheral space, resulting in a reverse pressure In this case, the extending portion of each lip piece is pressed against another adjacent lip piece by the pressure in the outer peripheral side space, thereby partitioning the inner peripheral side space and the outer peripheral side space. Therefore, it is possible to effectively suppress the backflow of fluid such as hydraulic oil or gas at the time of reverse pressure.

In another aspect of the present invention, a gap is formed between the two lip pieces adjacent in the circumferential direction by separating the end sides from each other, and on the outer peripheral side of the two adjacent lip pieces. The outer peripheral side check lip is formed so as to overlap each of the two adjacent lip pieces across the gap, and the outer peripheral side check lip is formed thinner than the lip piece.
According to the above configuration, a gap is formed between the two lip pieces adjacent to each other in the circumferential direction by separating the end sides from each other. When the fluid flows in and the pressure in the inner space rises and becomes higher than the pressure in the outer space, the fluid tries to flow out to the outer space through this gap. . At this time, since the outer peripheral side check lip that overlaps each of the two adjacent lip pieces across the gap is formed thinner than the lip piece, it easily deforms to bend toward the outer peripheral side, and the adjacent lip By opening the gap between the pieces, the fluid in the inner peripheral space easily flows to the reservoir chamber via the gap and the outer peripheral space. Therefore, it is possible to effectively reduce the valve opening pressure of the check lip.
Further, since the outer peripheral side check lip is located on the outer peripheral side of the two adjacent lip pieces and overlaps, the pressure in the outer peripheral space becomes higher than the pressure in the inner peripheral space and becomes a reverse pressure. In this case, the outer peripheral side check lip is pressed against each of the two adjacent lip pieces by the pressure in the outer peripheral side space, thereby dividing the inner peripheral side space and the outer peripheral side space. Therefore, it is possible to effectively suppress the backflow of fluid such as hydraulic oil or gas at the time of reverse pressure.

In another aspect of the present invention, each of the two lip pieces adjacent to each other in the circumferential direction is spaced apart from each other in the circumferential direction, and is adjacent to the lip piece adjacent from the inner peripheral side toward the outer peripheral side. A valve body having a shape corresponding to each end of each of the lip pieces is openable and closable between the adjacent lip pieces. It is provided as follows.
According to the above configuration, each of the two lip pieces adjacent to each other in the circumferential direction is spaced apart from each other in the circumferential direction, and the valve body is adjacent to the lip piece between the adjacent lip pieces. It is provided so that the space can be freely opened and closed. For this reason, when fluid such as hydraulic fluid flows into the inner circumferential space and the pressure in the inner circumferential space rises and becomes higher than the pressure in the outer circumferential space, the increased inner circumferential side The valve element is separated from the lip piece to the outer peripheral side by the pressure of the space. At this time, each of the two lip pieces adjacent to each other in the circumferential direction is formed so that the distance from the adjacent lip piece increases from the inner peripheral side toward the outer peripheral side, and the valve body is formed of each lip piece. Since the shape corresponds to the end, the valve body is easily separated from the lip piece. Thereby, the fluid in the space on the inner peripheral side easily flows to the reservoir chamber through the gap formed by opening the gap between the lip pieces that are separated from each other. Therefore, it is possible to effectively reduce the valve opening pressure of the check lip.
Each of the two lip pieces adjacent to each other in the circumferential direction is formed so that the distance from the adjacent lip piece increases from the inner peripheral side toward the outer peripheral side, and the valve body is formed at each end of the lip piece. The shape corresponds to the part. For this reason, the lip piece and the valve body overlap each other at the end portion of the lip piece where the separation dimension is changed, and the valve body covers the lip piece from the outer peripheral side. Here, when the pressure in the outer circumferential space is higher than the pressure in the inner circumferential space and becomes a reverse pressure, the valve body located on the outer circumferential side in the overlapped portion Is pressed against each of the two adjacent lip pieces located on the inner peripheral side by the pressure of the pressure, and the space between the adjacent lip pieces is closed to partition the inner peripheral space and the outer peripheral space. Therefore, it is possible to effectively suppress the backflow of fluid such as hydraulic oil or gas at the time of reverse pressure.

In another aspect of the present invention, the check lip is cut at an angle with respect to a plane passing through the central axis of the check lip from the tip toward the base at a plurality of positions in the circumferential direction. The plurality of lip pieces are formed.
According to the above configuration, the check lip is cut from the tip toward the base at a plurality of positions in the circumferential direction to form a plurality of lip pieces. For this reason, when fluid such as hydraulic fluid flows into the inner circumferential space and the pressure in the inner circumferential space rises and becomes higher than the pressure in the outer circumferential space, the increased inner circumferential side The incision between the lip pieces is opened by the pressure in the space. Thereby, the fluid in the space on the inner peripheral side easily flows to the reservoir chamber via the space on the outer peripheral side. Therefore, it is possible to effectively reduce the valve opening pressure of the check lip.
Further, the above-mentioned cut is made at an angle with respect to a plane passing through the central axis of the check lip. For this reason, of two adjacent lip pieces, the cut end surface of one lip piece faces the outer peripheral side with respect to the circumferential direction, and the end surface of the other lip piece facing this is the inner peripheral side with respect to the circumferential direction. In this case, the lip piece and the notch are overlapped in the circumferential direction so as to cover from the outer peripheral side. Here, when the pressure in the outer circumferential space is higher than the pressure in the inner circumferential space and becomes a reverse pressure, the other lip piece located on the outer circumferential side in the overlapped portion is It is pressed against one lip piece located on the inner peripheral side by the pressure in the space, and divides the inner peripheral side space and the outer peripheral side space. Therefore, it is possible to effectively suppress the backflow of fluid such as hydraulic oil or gas at the time of reverse pressure.

  ADVANTAGE OF THE INVENTION According to this invention, the sealing device for hydraulic shock absorbers which can reduce the valve opening pressure of a check lip can be provided.

It is sectional drawing of the rod guide vicinity of the hydraulic shock absorber provided with the sealing device for hydraulic shock absorbers in 1st Embodiment of this invention. It is an enlarged view of the sealing device vicinity of FIG. It is a perspective view of the contact part of the check lip of a sealing device, and the projection part of a rod guide in the sealing device for hydraulic shock absorbers of the said 1st Embodiment. In the sealing device for hydraulic shock absorbers of the first embodiment, (a) is a perspective view and (b) is a cross-sectional view of a contact portion between a check lip of a sealing device and a protruding portion of a rod guide when the valve is opened. It is sectional drawing of the contact part of the check lip of a sealing device and the protrusion part of a rod guide in the 1st modification of 1st Embodiment of this invention. It is sectional drawing of the contact part of the check lip of a sealing device and the protrusion part of a rod guide in the 2nd modification of 1st Embodiment of this invention. It is sectional drawing of the sealing device vicinity in the 3rd modification of 1st Embodiment of this invention. (A) is a top view, (b) is sectional drawing, (c) is explanatory drawing of the check lip of the sealing device for hydraulic shock absorbers in 2nd Embodiment of this invention. It is explanatory drawing of the check lip of the sealing device for hydraulic shock absorbers in the said 2nd Embodiment. In the modification of 2nd Embodiment of this invention, (a) is a top view, (b) is sectional drawing, (c) is explanatory drawing of the check lip of the sealing device for hydraulic shock absorbers. It is explanatory drawing of the check lip of the sealing device for hydraulic shock absorbers in the modification of 2nd Embodiment of this invention. (A) is sectional drawing, (b) is the expanded perspective view, (c) is the expanded perspective view at the time of valve opening of the check lip of the sealing device for hydraulic shock absorbers in 3rd Embodiment of this invention. In the modified example of the third embodiment of the present invention, (a) is a cross-sectional view, (b) is an enlarged perspective view, and (c) is an enlarged perspective view when the valve is opened, of the check lip of the hydraulic shock absorber sealing device. It is. (A) is sectional drawing, (b) is the expanded perspective view, (c) is the expanded perspective view at the time of valve opening of the check lip of the sealing device for hydraulic shock absorbers in 4th Embodiment of this invention. It is explanatory drawing of the sealing device for conventional hydraulic shock absorbers.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view of the vicinity of a rod guide 5 of a hydraulic shock absorber 1 provided with a hydraulic shock absorber sealing device 10 according to a first embodiment of the present invention. In the first embodiment, the hydraulic shock absorber 1 is of a double cylinder type, and is provided in the inner cylinder 2, the outer cylinder 3 covering the inner cylinder 2, and the inner cylinder 2 so as to be movable in the axis O direction. The piston rod 4 is provided with a rod guide 5 that closes the open ends 2 a and 3 a of the inner cylinder 2 and the outer cylinder 3 and pivotally supports the piston rod 4, and a sealing device 10.

  The outer cylinder 3 extends in the axis O direction beyond the end of the inner cylinder 2. The end of the outer cylinder 3 includes a crimped portion 3b that is bent toward the inner peripheral side.

The rod guide 5 is formed in an annular shape, and includes a fitting portion 5 a that protrudes toward the inner space of the inner cylinder 2 on the inner peripheral side. The rod guide 5 is attached to the inner cylinder 2 so that the fitting portion 5 a is inserted into the inner space of the inner cylinder 2 and closes the opening end 2 a of the inner cylinder 2. The rod guide 5 is provided so that the outer surface 5 b contacts the inner side of the outer cylinder 3, and closes the opening end 3 a of the outer cylinder 3.
On the outside of the rod guide 5 in the direction of the axis O, that is, on the side opposite to the side where the fitting portion 5a is provided, a concave portion 5d is formed on the inner peripheral side, and a convex portion 5e is formed on the outer peripheral side in an annular shape. Yes. A step portion 5f is formed at a position while rising from the concave portion 5d to the convex portion 5e so as to form a plane substantially orthogonal to the axis O.

  On the inner surface 5c of the rod guide 5, a bearing sleeve 6 made of a synthetic resin material having a low friction coefficient and excellent wear resistance such as PTFE is mounted.

A piston (not shown) is joined to one end of the piston rod 4. The piston rod 4 is provided so that the piston is inside the inner cylinder 2 and the end opposite to the end where the piston is joined projects outward from the open ends 2a and 3a of the inner cylinder 2 and the outer cylinder 3. It has been.
The piston rod 4 is provided so as to pass through the inside of the rod guide 5 and the bearing sleeve 6, and is supported so as to be slidable with respect to the rod guide 5. It is provided so as to be movable in the direction of the axis O.

A space between the inner cylinder 2 and the piston rod 4 and closed by the rod guide 5 is an oil chamber S1 filled with hydraulic oil (fluid).
In addition, a space between the inner cylinder 2 and the outer cylinder 3 that is closed by the rod guide 5 is a reservoir chamber S2 in which gas is sealed. Under the reservoir chamber S2, hydraulic oil pushed out from the inner cylinder 2 when the piston moves in a direction to be inserted into the inner cylinder 2 is guided through a base valve (not shown). That is, the reservoir chamber S2 is provided with a mixture of gas and hydraulic oil (fluid).

The sealing device 10 abuts the rod guide 5 on the metal ring 11 provided on the opposite side of the rod guide 5 from the opening end 2a of the inner cylinder 2 and on the side of the metal ring 11 facing the rod guide 5. And an annular check lip 15 that allows only the flow of fluid from the space between the rod guide 5 and the metal ring 11 toward the reservoir chamber S2 formed between the inner cylinder 2 and the outer cylinder 3. ing.
The sealing device 10 further includes a main lip 12, a dust lip 13, and an outer peripheral lip 14.
FIG. 2 is an enlarged view of the vicinity of the sealing device 10 of FIG. In FIG. 2, the shapes of the main lip 12, the dust lip 13, and the outer peripheral lip 14 before the sealing device 10 is attached are indicated by two-dot chain lines.

The metal ring 11 is formed in a flat washer shape, and is clamped and fixed by a caulking portion 3 b of the outer cylinder 3 and a convex portion 5 e of the rod guide 5.
The main lip 12, the dust lip 13, the outer peripheral lip 14, and the check lip 15 are formed on the metal ring 11 with rubber or a synthetic resin having rubber-like elasticity.

  The main lip 12 is provided on the inner peripheral side of the metal ring 11 so as to extend inward in the direction of the axis O, that is, toward the oil chamber S1 shown in FIG. A garter spring 17 is annularly fitted on the outer peripheral side of the main lip 12. When the sealing device 10 is attached, the main lip 12 is positioned in the main lip chamber S3 formed by the concave portion 5d of the rod guide 5, the piston rod 4, and the sealing device 10, and the garter spring. 17 slidably contacts the outer peripheral surface of the piston rod 4. As a result, the main lip 12 moves from the oil chamber S1 shown in FIG. 1 to the main lip chamber S3 via the gap G between the rod guide 5 and the piston rod 4, and the outer periphery of the piston rod 4 is accommodated. And leakage from between the sealing device 10 to the outside.

  The dust lip 13 is provided on the inner peripheral side of the metal ring 11 so as to extend outward in the axis O direction. A garter spring 18 is annularly fitted on the outer periphery of the dust lip 13. When the sealing device 10 is attached, the dust lip 13 is slidably brought into close contact with the outer peripheral surface of the piston rod 4 by a garter spring 18. Thereby, the dust lip 13 suppresses entry of dust, muddy water, and the like into the hydraulic shock absorber 1 from the outside between the outer periphery of the piston rod 4 and the sealing device 10.

  The outer peripheral lip 14 is provided on the outer peripheral side of the metal ring 11 so as to extend inward in the axis O direction. The outer peripheral lip 14 is pressure-bonded to the inner surface of the outer cylinder 3 and the outer surface of the convex portion 5e of the rod guide 5, so that the hydraulic oil and gas contained in the reservoir chamber S2 shown in FIG. Further, leakage from between the rod guide 5 and the outer cylinder 3 to the outside is suppressed.

  Next, the check lip 15 will be described. The check lip 15 includes a plurality of lip pieces 16 in the circumferential direction. The rod guide 5 includes an annular projecting portion 5g projecting to the side facing the metal ring 11, and the check lip 15 abuts on the outer peripheral surface 5h of the projecting portion 5g, and at a plurality of positions in the circumferential direction. A plurality of lip pieces 16 are formed by cutting from the tip 15a toward the base 15b.

More specifically, the protruding portion 5g of the rod guide 5 protrudes toward the inner side of the step portion 5f of the rod guide 5 toward the outer side in the axis O direction, that is, the direction in which the metal ring 11 is positioned. Is provided. The tip 5i of the projecting part 5g is positioned so as to be lower than the convex part 5e, whereby a gap G1 is formed between the sealing device 10 provided on the convex part 5e and the tip 5i. Is formed.
The outer peripheral surface 5h of the protruding portion 5g is formed to be substantially perpendicular to the step portion 5f.

  The check lip 15 is provided on the outer peripheral side of the main lip 12 on the inner surface in the axis O direction of the metal ring 11. The check lip 15 is formed to rise substantially vertically from the inner surface of the metal ring 11 in the axis O direction. When the sealing device 10 is attached, the check lip 15 is positioned slightly on the outer peripheral side of the protruding portion 5g of the rod guide 5, and the inner peripheral surface 15c of the check lip 15 is on the outer peripheral side of the protruding portion 5g. It is provided so as to come into contact with and separate from the surface 5h.

  A check lip is formed by the inner surface in the direction of the axis O of the sealing device 10, the check lip 15, the step portion 5f of the rod guide 5, the inner peripheral surface of the convex portion 5e of the rod guide 5, and the outer peripheral surface 5h of the protruding portion 5g. 15 is divided from the main lip chamber S3 to form an open chamber S4. In the rod guide 5, a communication hole 5j is formed on the outer peripheral side of the protruding portion 5g of the rod guide 5 so as to communicate between the open chamber S4 and the reservoir chamber S2 shown in FIG.

FIG. 3 is a perspective view of a contact portion between the check lip 15 of the sealing device 10 and the protruding portion 5g of the rod guide 5 in the sealing device 10. As described above, since the check lip 15 is formed in an annular shape, in FIG. 3, the portions of the check lip 15 and the protruding portion 5g that are located on the back side and cannot be seen from the angle shown in FIG. This is indicated by a broken line.
As shown in FIG. 3, the check lip 15 includes cuts 15 d at a plurality of positions in the circumferential direction. The cut 15d is cut from the tip 15a of the check lip 15 toward the base 15b. As shown by the broken line in FIG. 2, the notch 15d has such a depth that the deepest part of the notch 15d is located at a height substantially equal to the tip 5i of the protruding part 5g when the sealing device 10 is attached. , Provided.

In the first embodiment, as shown in FIG. 3, two cuts 15d are provided on the front side of the protrusion 5g in FIG. 3, and two cuts 15d indicated by broken lines on the back side of the protrusion 5g are shown in FIG. There are four books in total. As a result, the check lip 15 has its tip 15a portion divided into four to form four lip pieces 16.
The notches 15d are provided so as to radially cut the check lip 15 formed in an annular shape from the axis O located at the center of the annular shape. Thereby, when each lip piece 16 is viewed in a cross-section so as to be orthogonal to the axis O, the lip piece 16 includes two arcs corresponding to the outer peripheral side surface and the inner peripheral surface 15c of the check lip 15, A thick arc shape is formed by two side edges connecting the end points of these arcs.

Next, the operation of the hydraulic shock absorber sealing device 10 will be described with reference to FIGS. 1 to 3 and FIG. 4 which have already been described.
4A is a perspective view of a contact portion between the check lip 15 of the sealing device 10 and the protruding portion 5g of the rod guide 5 when the valve is opened, and FIG. 4B is a cross-sectional view taken along a line AA in FIG. It is sectional drawing.

  When a relative movement in the direction of the axis O of the piston rod 4 with respect to the inner cylinder 2 and the outer cylinder 3 occurs due to an impact during travel of the vehicle provided with the hydraulic shock absorber 1, it is attached to the inner end of the piston rod 4. A piston (not shown) together with the piston rod 4 in the inner cylinder 2 in the direction of the axis O, in a direction in which the piston rod 4 protrudes outward, or in a direction in which the piston rod 4 is inserted into the inner cylinder 2 , Move relative. At this time, a vibration damping force is generated by the working oil flowing between the oil chambers located on the opposite sides of the piston in the inner cylinder 2 through the restriction flow path provided in the piston. Thereby, the impact on the vehicle is effectively mitigated and the vibration is converged.

  First, the case where the piston rod 4 moves relative to the direction protruding outward will be described. In this case, the movement of the piston joined to the piston rod 4 in the outward projecting direction reduces the volume of the portion of the oil chamber S1 located closer to the piston rod 4 than the piston. Part of the hydraulic oil in the chamber S1 flows into the main lip chamber S3 through the gap G between the bearing sleeve 6 provided in the rod guide 5 and the outer peripheral surface of the piston rod 4. Thereby, the pressure of the hydraulic oil in the main lip chamber S3 gradually increases.

  When the pressure in the main lip chamber S3 becomes higher than the pressure in the open chamber S4 on the outer peripheral side of the check lip 15, the differential pressure causes the check lip 15 to move from the outer peripheral surface 5h of the protruding portion 5g of the rod guide 5. Acts in the direction of separation. This differential pressure tends to keep the check lip 15 in a steady state in which the inner peripheral surface 15c of the check lip 15 is in contact with the outer peripheral surface 5h of the protrusion 5g. When exceeding the elastic force, the check lip 15 is elastically deformed toward the outer peripheral side so as to be separated from the outer peripheral side surface 5h of the protruding portion 5g of the rod guide 5.

  Here, each of the lip pieces 16 formed at the tip 15a of the check lip 15 is separated from the other lip pieces 16 by the notch 15d, so that the shape of the check lip 15 from the other lip pieces 16 is reduced. This suppresses the influence of tension, which tries to maintain a steady state. Therefore, the lip piece 16 is very easily deformed so as to be separated from the protruding portion 5g toward the outer peripheral side as shown in FIG. 4, and the main lip chamber S3 and the open chamber S4 communicate with each other.

  The main lip chamber S3 and the open chamber S4 communicate with each other, and a certain amount of hydraulic oil flows into the reservoir chamber S2 via the open chamber S4 and the communication hole 5j of the rod guide 5 through the open chamber S4. After that, the pressure in the main lip chamber S3 and the pressure in the open chamber S4 are substantially equal. As described above, when the pressure difference between the pressure in the main lip chamber S3 and the pressure in the open chamber S4 becomes equal to or less than a certain level, the check lip 15 is moved to the inner peripheral side of the check lip 15 by the elastic restoring force of the check lip 15. The surface 15c is restored to a steady state in which the surface 15c is in contact with the outer peripheral surface 5h of the protrusion 5g.

  On the other hand, when the piston rod 4 moves relative to the direction in which the piston rod 4 is inserted into the inner cylinder 2, the piston joined to the piston rod 4 moves in the direction into which the piston rod 4 is inserted into the inner cylinder 2. A volume of a portion of the chamber S1 located on the opposite side of the piston rod 4 from the piston is reduced, and a part of the hydraulic oil is provided on the opposite side of the hydraulic shock absorber 1 from the sealing device 10 (not shown). Since it flows into the reservoir chamber S2 communicating with this portion via the valve, the pressure in the space from the reservoir chamber S2 to the open chamber S4 via the communication hole 5j gradually increases.

  When the pressure in the open chamber S4 becomes a reverse pressure state in which the pressure in the open lip chamber S3 is higher than the pressure in the main lip chamber S3, the differential pressure acts to move the check lip 15 in the direction of the piston rod 4. At this time, the lip piece 16 of the check lip 15 is pressed against the outer peripheral surface 5h of the protruding portion 5g of the rod guide 5 located slightly on the inner peripheral side than the check lip 15, and is more inward than the outer peripheral surface 5h. It does not deform so as to move to the circumferential side. That is, at the time of reverse pressure, the check lip 15 and the lip piece 16 reliably partition the main lip chamber S3 and the open chamber S4.

  Next, the effect of the hydraulic shock absorber sealing device 10 will be described.

  According to the above configuration, the check lip 15 is provided on the side of the metal ring 11 that faces the rod guide 5 so as to contact the rod guide 5, and therefore, between the rod guide 5 and the metal ring 11. Is divided into a main lip chamber S3 which is a space on the inner peripheral side of the check lip 15 and an open chamber S4 which is a space on the outer peripheral side of the check lip 15. Further, the check lip 15 includes a plurality of lip pieces 16 in the circumferential direction, and the check lip 15 is partially deformed, for example, a certain lip piece 16 as compared with a case where the check lip 15 is integrally formed in the circumferential direction. At this time, since the influence of the tension, which tries to keep the shape of the check lip 15 from the other lip piece 16 in a steady state, is suppressed, the check lip 15 is easily deformed. That is, when the hydraulic oil flows into the main lip chamber S3 and the pressure in the main lip chamber S3 increases and becomes higher than the pressure in the open chamber S4, each lip piece is caused by the increased pressure in the main lip chamber S3. 16 is easily deformed, and the hydraulic oil in the main lip chamber S3 easily flows to the reservoir chamber S2 via the open chamber S4 and the communication hole 5j provided in the rod guide 5. Therefore, the valve opening pressure of the check lip 15 can be effectively reduced.

  The plurality of lip pieces 16 are formed by separating the lip pieces 16 by cutting the check lip 15 from the tip 15a toward the base portion 15b at a plurality of positions in the circumferential direction. Therefore, when the hydraulic oil flows into the main lip chamber S3 and the pressure in the main lip chamber S3 increases and becomes higher than the pressure in the open chamber S4, the lip piece 16 is caused by the increased pressure in the main lip chamber S3. By opening the notch 15d, the hydraulic oil in the main lip chamber S3 easily flows to the reservoir chamber S2 through the open chamber S4 and the communication hole 5j provided in the rod guide 5. Therefore, the valve opening pressure of the check lip 15 can be effectively reduced.

  Further, the rod guide 5 includes an annular projecting portion 5g projecting to the side facing the metal ring 11, and the check lip 15 is in contact with the outer peripheral surface 5h of the projecting portion 5g. When the pressure in the main lip chamber S3 becomes higher than the pressure in the main lip chamber S3, the lip pieces 16 are pressed against the outer peripheral surface 5h of the protruding portion 5g by the pressure in the open chamber S4. And an open room S4. Therefore, it is possible to effectively suppress the backflow of hydraulic oil and gas at the time of reverse pressure.

  As described above, the plurality of lip pieces 16 are formed by the check lip 15 being cut from the tip 15a toward the base portion 15b and separating the lip pieces 16 from each other. The depth of the notch 15d is provided at a depth substantially equal to the tip 5i of the part 5g, that is, the notch is formed in the gap G1 between the sealing device 10 and the tip 5i of the rod guide 5. Since 15d is not exposed, it is possible to effectively suppress the backflow of hydraulic oil or gas through the cut 15d even during back pressure.

(First modification of the first embodiment)
Next, a first modification of the hydraulic shock absorber sealing device 10 shown as the first embodiment will be described with reference to FIG. FIG. 5 is a cross-sectional view of a contact portion between the check lip 21 of the sealing device and the protruding portion 20a of the rod guide 20 in the hydraulic shock absorber of the first modification. The sealing device of the first modified example is different from the sealing device 10 in the first embodiment in the angle of the check lip 21 with respect to the surface of the metal ring 11.

  In the first embodiment, as shown in FIG. 2, the outer peripheral surface 5h of the protruding portion 5g is provided so as to be substantially perpendicular to the stepped portion 5f. On the other hand, in the first modified example, as shown in FIG. 5, the protruding portion 20a of the rod guide 20 is provided such that the outer peripheral surface 20b thereof is obtusely angled with respect to the stepped portion 20c. Yes.

  Similarly, in the first embodiment, as shown in FIG. 2, the check lip 15 is formed to rise substantially vertically from the surface of the metal ring 11. On the other hand, in the first modified example, as shown in FIG. 5, the check lip 21 has an inner peripheral surface 21 a along the outer peripheral surface 20 b of the protruding portion 20 a of the rod guide 20. Like the outer peripheral side surface 20 b, the inclined surface is provided, and an obtuse angle is provided with respect to the surface of the metal ring 11 on the main lip chamber S 3 side.

It goes without saying that the first modification has the same effects as those of the first embodiment.
In particular, in the configuration of the first modified example, the check lip 21 has an inner peripheral surface 21a provided with an obtuse angle with respect to the surface of the metal ring 11 on the main lip chamber S3 side. The check lip 21 is more easily deformed in the direction of the open chamber S4. Thereby, the valve opening pressure of the check lip 21 can be reduced more effectively than in the first embodiment.

(Second modification of the first embodiment)
Next, a second modification of the hydraulic shock absorber sealing device 10 shown as the first embodiment will be described with reference to FIG. FIG. 6 is a cross-sectional view of a contact portion between the check lip 31 of the sealing device and the protrusion 30a of the rod guide 30 in the hydraulic shock absorber of the second modification. The sealing device of the second modified example is different from the sealing device 10 of the first embodiment in the angle of the check lip 31 with respect to the surface of the metal ring 11 as in the first modified example.

In the second modification, the protruding portion 30a of the rod guide 30 is provided with an outer peripheral side surface 30b having an acute angle with respect to the stepped portion 30c.
Further, the check lip 31 is provided so as to be inclined in the same manner as the outer peripheral surface 30 b so that the inner peripheral surface 31 a thereof is along the outer peripheral surface 30 b of the protruding portion 30 a of the rod guide 30. Thereby, the outer peripheral side surface 31b of the check lip 31 is provided with an obtuse angle with respect to the surface of the metal ring 11 on the open chamber S4 side.

Needless to say, the second modified example has the same effect as the first embodiment.
In particular, in the configuration of the second modified example, the check lip 31 is provided with an obtuse angle with respect to the surface of the metal ring 11 on the open chamber S4 side. More difficult to deform in the direction. Thereby, it is possible to suppress the backflow of the hydraulic oil and gas at the time of back pressure more effectively than the first embodiment.

(Third Modification of First Embodiment)
Next, a third modification of the hydraulic shock absorber sealing device 10 shown as the first embodiment will be described with reference to FIG. FIG. 7 is an enlarged view of the vicinity of the sealing device 60 in the hydraulic shock absorber of the third modification. The sealing device 60 of the third modified example is different from the sealing device 10 in the first embodiment in the depth of the cut 61d provided in the check lip 61.

In the third modification, when the sealing device 60 is attached, the notch 61d is positioned so that the deepest part of the notch 61d is higher than the tip 5i of the protrusion 5g of the rod guide 5, and the notch 61d is cut into the gap G1. Is provided at such a depth as to be partially exposed.
The notches 61d are provided so as to cut radially from the axis O located at the center of the ring as in the first embodiment, and each lip piece 62 is perpendicular to the axis O. When the cross-sectional view is taken, the thickness formed by two arcs corresponding to each of the outer peripheral surface 61c and the inner peripheral surface 61c of the check lip 61 and two side edges connecting the end points of these arcs. It has a circular arc shape.

  The hydraulic shock absorber sealing device 60 including the above-described check lip 61 operates as described below.

  When the piston rod 4 protrudes outward, and the pressure in the main lip chamber S3 becomes higher than the pressure in the open chamber S4, the differential pressure causes the check lip 61 to move to the outer peripheral surface 5h of the protrusion 5g of the rod guide 5. Acting in the direction of separating from. At this time, the notch 61d is provided in such a depth that the notch 61d is partially exposed in the gap G1, so that each of the lip pieces 62 is at least partially in the main lip chamber S3 in the gap G1. Each of the lip pieces 62 is exposed and directly receives the pressure in the main lip chamber S3. Therefore, each of the lip pieces 62 receives pressure in the main lip chamber S3 independently and deforms independently of the other lip pieces 62, so that the main lip chamber S3 and the open chamber S4 communicate with each other.

  Further, since the notch 61d is provided at such a depth that the notch 61d is partially exposed in the gap G1, the pressure in the main lip chamber S3 rises and becomes higher than the pressure in the open chamber S4. In addition, for example, as described with reference to FIG. 4A in the first embodiment, the lip piece 62 does not open toward the outer peripheral side as a whole, but among the plurality of cuts 61d between the lip pieces 62. For example, the main lip chamber S3 and the open chamber S4 can communicate with each other even when the notch 61d is partially opened.

  The main lip chamber S3 and the open chamber S4 communicate with each other, and the pressure in the main lip chamber S3 and the pressure in the open chamber S4 are substantially equal to each other. When the differential pressure of the check lip 61 becomes a certain value or less, the check lip 61 is in a steady state in which the inner peripheral surface 61c of the check lip 61 is in contact with the outer peripheral surface 5h of the protruding portion 5g due to the elastic restoring force of the check lip 61. Is restored to the normal state.

  When the piston rod 4 is inserted into the inner cylinder and the pressure in the open chamber S4 is in a reverse pressure state in which the pressure is higher than the pressure in the main lip chamber S3, the differential pressure causes the check lip 61 to Acts to move in the direction. At this time, the lip piece 62 of the check lip 61 is pressed against the outer peripheral surface 5h of the protruding portion 5g of the rod guide 5 located slightly on the inner peripheral side with respect to the check lip 61, so that the inner side is closer to the inner surface than the outer peripheral surface 5h. It does not deform so as to move to the circumferential side.

  In addition, as described above, each lip piece 62 has two arcs corresponding to the outer peripheral surface and the inner peripheral surface 61c of the check lip 61 when viewed in a cross-section so as to be orthogonal to the axis O, and A thick arc shape is formed by two side edges connecting the end points of these arcs. For this reason, in the back pressure state in which the pressure in the open chamber S4 located outside the check lip 61 having the annular shape is higher than the pressure in the main lip chamber S3 located inside, the pressure is increased from the outside of the annular shape. Due to this pressure, the opposing side edges of the adjacent lip pieces 62 in each notch 61d are strongly pressed against each other. Accordingly, the check lip 61 divides the main lip chamber S3 and the open chamber S4 during back pressure even though the notch 61d is provided with a depth that is partially exposed to the gap G1. .

Needless to say, the third modification has the same effects as those of the first embodiment.
In particular, in the configuration of the third modification, each of the lip pieces 62 is at least partially exposed to the main lip chamber S3 via the gap G1 and directly receives the pressure in the main lip chamber S3. Therefore, each of the lip pieces 62 can be independently deformed independently of the other lip pieces 62 under the pressure in the main lip chamber S3. As a result, the valve opening pressure of the check lip 61 can be further effectively reduced without significantly impairing the backflow suppression performance during backpressure as described above.

(Second Embodiment)
Next, a sealing device for a hydraulic shock absorber according to a second embodiment of the present invention will be described. FIG. 8A is a plan view of the check lip of the hydraulic shock absorber sealing device in the second embodiment, FIG. 8B is a cross-sectional view of the BB portion of FIG. 8A, and FIG. FIG. 9C is a perspective view of the vicinity of a portion B in FIG.
In the second embodiment, the lip piece 42 (42A, 42B, 42C, 42D) extends to one end in the circumferential direction and to the outer peripheral side of another lip piece 42 adjacent to the one end side, thereby providing another lip piece 42. The extending portion 42a is formed to be thinner than the overlapping portion 42b of the other lip piece 42.

  In FIG.8 (b), the rod guide 40 provided facing the sealing device of this 2nd Embodiment is shown with the dashed-two dotted line. The rod guide 40 does not include a portion corresponding to the protruding portion 5g described with reference to FIG. 1 and the like regarding the rod guide 5 in the first embodiment. That is, in the rod guide 40, the recess 40d rises at the outer peripheral end, the upper end thereof is the inner peripheral end of the step 40f, and the upper end of the recess 40d is directly connected to the step 40f. Yes.

  Like the check lip 15 in the first embodiment described above, the check lip 41 in the sealing device of the second embodiment is formed in an annular shape as shown in a plan view in FIG. It consists of a plurality of lip pieces 42 (42A, 42B, 42C, 42D), for example, four in the direction.

  As described above, each lip piece 42 is provided with an extending portion 42 a at one end in the circumferential direction that extends to the outer peripheral side of another lip piece 42 adjacent to one end side and overlaps with the other lip piece 42. . For example, the extending portion 42a of the lip piece 42A located at the upper left in FIG. 8A overlaps the end portion 42b of the lip piece 42B located at the upper right in FIG. Yes. The extending part 42a of the lip piece 42B overlaps with the end part 42b of the lip piece 42C located in the lower right in FIG. The extending part 42a of the lip piece 42C overlaps with the end part 42b of the lip piece 42D located in the lower left in FIG. The extending part 42a of the lip piece 42D overlaps the end part 42b of the lip piece 42A adjacent in the clockwise direction.

  Each lip piece 42 is formed to be separated from the lip pieces 42 adjacent to each other in the circumferential direction from the tip 41a to the base 41b at four portions in the circumferential direction. Since the extending portion 42a is provided so as to overlap with the end portion 42b of the lip piece 42 adjacent in the clockwise direction, the check lip 41 as a whole when viewed in plan as shown in FIG. It forms so that it may become one check lip 41 which is not spaced apart.

  As shown in FIGS. 8B and 8C, the extending portion 42a of each lip piece 42 is provided to extend to the outer peripheral side of the end portion 42b of the other lip piece 42. The extending portion 42a is formed thinner than the overlapping portion of the end portion 42b of the other lip piece 42.

  The shape of the check lip 41 shown in FIG. 8 (b) is that before the sealing device is attached. When the sealing device is attached, the check lip 41 has two shapes in FIG. 8 (b). In accordance with the shape of the stepped portion 40f of the rod guide 40 indicated by the dotted line, the rod guide 40 is provided to bend toward the outer peripheral side.

  The structure of the other parts of the hydraulic shock absorber according to the second embodiment is the same as that of the hydraulic shock absorber 1 according to the first embodiment and the sealing device 10 provided therein.

Next, the operation of the hydraulic shock absorber sealing device provided with the check lip 41 will be described with reference to FIGS. 8 and 9 described above.
FIG. 9 is a perspective view showing the shape of the check lip 41 when the valve is opened, corresponding to FIG.

  When the piston rod protrudes outward and the pressure in the main lip chamber S3 becomes higher than the pressure in the open chamber S4, the differential pressure acts in a direction to separate the check lip 41 from the step portion 40f of the rod guide 40. To do. At this time, the extending portion 42a of each lip piece 42 is provided so as to extend to the outer peripheral side of the other lip piece 42, and the extending portion 42a is over the end portion 42b of the other lip piece 42. Since it is formed thinner than the wrapping portion, as shown in FIG. 9, the extending portion 42a bends in the direction of the open chamber S4 and overlaps the end portion 42b of the other lip piece 42. The main lip chamber S3 and the open chamber S4 are communicated with each other by forming a gap between the adjacent lip pieces 42.

  The main lip chamber S3 and the open chamber S4 communicate with each other, and the pressure in the main lip chamber S3 and the pressure in the open chamber S4 are substantially equal to each other. When the pressure differential pressure is below a certain level, the check lip 41 comes into contact with the outer peripheral surface of the end portion 42b of the adjacent lip piece 42 due to the elastic restoring force of the check lip 41. Is restored to a steady state.

  When the piston rod is inserted into the inner cylinder and the pressure in the open chamber S4 is in a reverse pressure state in which the pressure is higher than the pressure in the main lip chamber S3, the differential pressure causes the check lip 41 to move toward the piston rod. Acts to move. At this time, the tip 41a of the check lip 41 is pressed against the step 40f of the rod guide 40, and the extending part 42a of each lip piece 42 is formed thicker, and the end part 42b of the adjacent lip piece 42 is formed. Is pressed against the overlapping part. Thereby, at the time of back pressure, the check lip 41 and the lip piece 42 reliably partition the main lip chamber S3 and the open chamber S4.

  Next, effects of the hydraulic shock absorber sealing device according to the second embodiment will be described.

  According to the above configuration, the extending portion 42a of the lip piece 42 that overlaps with the other adjacent lip piece 42 is formed thinner than the overlapping portion of the other lip piece 42. When the hydraulic oil flows into the main lip chamber S3 and the pressure in the main lip chamber S3 increases and becomes higher than the pressure in the open chamber S4, the thinly formed extending portion 42a rises in the main lip chamber S3. Is easily deformed so as to bend to the outer peripheral side by the pressure of the pressure, and a gap is formed between the adjacent lip pieces 42, so that the hydraulic oil in the main lip chamber S3 is opened in the gap, the open chamber S4, and the rod guide. The structure is such that it easily flows to the reservoir chamber through the communicating hole. Therefore, the valve opening pressure of the check lip 42 can be effectively reduced.

  In addition, since the extending portion 42a extends and overlaps the outer peripheral side of another adjacent lip piece 42, the pressure in the open chamber S4 becomes higher than the pressure in the main lip chamber S3 and becomes a reverse pressure. , The extending portion 42a of each lip piece 42 is pressed against another adjacent lip piece 42 by the pressure in the open chamber S4, thereby dividing the main lip chamber S3 and the open chamber S4. Therefore, it is possible to effectively suppress the backflow of hydraulic oil and gas at the time of reverse pressure.

(Modification of the second embodiment)
Next, a modified example of the hydraulic shock absorber sealing device shown as the second embodiment will be described with reference to FIG. FIG. 10A is a plan view of a check lip of a hydraulic shock absorber sealing device according to a modification of the second embodiment, and FIG. 10B is a cross-sectional view taken along a line CC in FIG. 10A. FIG.10 (c) is a perspective view of C vicinity vicinity of Fig.10 (a).
The sealing device of the present modification is different from the sealing device in the second embodiment in the configuration of the check lip 51, and each end side is between two lip pieces 52 adjacent in the circumferential direction. A gap G2 is formed by being separated, and an outer peripheral side check lip 53 that overlaps each of the two adjacent lip pieces 52 across the gap G2 is formed on the outer peripheral side of the two adjacent lip pieces 52, The outer peripheral side check lip 53 is formed thinner than the lip piece 52.

  Also in FIG. 10B, the rod guide 40 is indicated by a two-dot chain line, as in FIG. 8B described in the second embodiment. The rod guide 40 is configured in the same manner as in the second embodiment.

  The check lip 51 in the sealing device of the present modification is formed in an annular shape as shown in the plan view of FIG. 10A, like the check lips 15 and 41 in the first and second embodiments described above. And a plurality of, for example, four, lip pieces 52 in the circumferential direction.

  As described above, the gap G <b> 2 is formed between the two lip pieces 52 adjacent in the circumferential direction by separating the end sides from each other. In addition, an outer peripheral check lip 53 that overlaps each of the two adjacent lip pieces 52 is formed on the outer peripheral side of the two adjacent lip pieces 52 so as to block the gap G2 with respect to each gap G2. Yes.

Each lip piece 52 is formed to be separated from the lip piece 52 adjacent in the circumferential direction from the tip 51a to the base 51b in four parts in the circumferential direction. However, as described above, the outer peripheral side check lip 53 is formed. Are provided so as to overlap each of the adjacent lip pieces 52, and the check lip 51 is not spaced as a whole when viewed in plan as shown in FIG. The check lip 51 is formed.
The outer peripheral side check lip 53 is formed thinner than the overlapping part of each lip piece 52.

  The shape of the check lip 51 shown in FIG. 10 (b) is that before the sealing device is attached. When the sealing device is attached, the check lip 51 is shown in FIG. 10 (b). In accordance with the shape of the stepped portion 40f of the rod guide 40 indicated by the dotted line, the rod guide 40 is provided to bend toward the outer peripheral side.

Next, the operation of the sealing device for a hydraulic shock absorber provided with the check lip 51 will be described with reference to FIGS. 10 and 11 described above.
FIG. 11 is a perspective view showing the shape of the check lip 51 when the valve is opened, corresponding to FIG.

  When the piston rod protrudes outward and the pressure in the main lip chamber S3 becomes higher than the pressure in the open chamber S4, the differential pressure acts in a direction to separate the check lip 51 from the step portion 40f of the rod guide 40. To do. At this time, since the outer peripheral side check lip 53 is formed on the outer peripheral side of the lip piece 52, and the outer peripheral side check lip 53 is formed thinner than the lip piece 52, as shown in FIG. The outer peripheral side check lip 53 bends in the direction of the open chamber S4 and is deformed so as to be separated from the overlapping portion of each lip piece 52, and a gap G2 is formed between the adjacent lip pieces 52, and the main lip The room S3 and the open room S4 communicate with each other.

  The main lip chamber S3 and the open chamber S4 communicate with each other, and the pressure in the main lip chamber S3 and the pressure in the open chamber S4 are substantially equal to each other. When the pressure difference between the lip pieces 52 becomes a certain value or less, the outer peripheral check lip 53 is restored to a steady state in contact with the outer peripheral surface of each lip piece 52 by the elastic restoring force of the outer peripheral check lip 53. The

  When the piston rod is inserted into the inner cylinder and the pressure in the open chamber S4 becomes a reverse pressure state in which the pressure is higher than the pressure in the main lip chamber S3, the differential pressure causes the check lip 51 to move toward the piston rod. Acts to move. At this time, the tip 51a of the check lip 51 is pressed against the stepped portion 40f of the rod guide 40, and each outer peripheral check lip 53 is moved to an overlapping portion of the lip piece 52 formed to be thicker. Pressed. Thereby, at the time of back pressure, the check lip 51 and the lip piece 52 reliably partition the main lip chamber S3 and the open chamber S4.

  Next, effects of the hydraulic shock absorber sealing device according to the modification of the second embodiment will be described.

  According to the above configuration, the gap G2 is formed between the two lip pieces 52 adjacent to each other in the circumferential direction by separating the end sides from each other, so that the hydraulic oil is supplied to the main lip chamber S3. When the pressure in the main lip chamber S3 rises and becomes higher than the pressure in the open chamber S4, the hydraulic oil tends to flow out to the open chamber S4 through the gap G2. At this time, since the outer peripheral side check lip 53 that overlaps each of the two adjacent lip pieces 52 across the gap G2 is formed thinner than the lip piece 52, it easily deforms to bend toward the outer peripheral side. When the gap G2 between the adjacent lip pieces 52 is opened, the hydraulic oil in the main lip chamber S3 passes through the gap G2, the open chamber S4, and the communication hole provided in the rod guide, and the reservoir chamber It has a structure that flows easily. Therefore, the valve opening pressure of the check lip 51 can be effectively reduced.

  Further, since the outer peripheral side check lip 53 is located on the outer peripheral side of the two adjacent lip pieces 52 and overlaps, the pressure in the open chamber S4 becomes higher than the pressure in the main lip chamber S3 and becomes a reverse pressure. In this case, the outer peripheral side check lip 53 is pressed against each of the two adjacent lip pieces 52 by the pressure in the open chamber S4, thereby dividing the main lip chamber S3 and the open chamber S4. Therefore, it is possible to effectively suppress the backflow of hydraulic oil and gas at the time of reverse pressure.

(Third embodiment)
Next, a hydraulic shock absorber sealing device according to a third embodiment of the present invention will be described. 12A is a cross-sectional view of the check lip of the hydraulic shock absorber sealing device according to the third embodiment, FIG. 12B is a perspective view in the vicinity of a portion D in FIG. 12A, and FIG. FIG. 13B is a perspective view when the valve is opened in the vicinity of a portion D in FIG.
In the third embodiment, each of the two lip pieces 72 adjacent to each other in the circumferential direction has the circumferential ends 72b separated from each other, and from the inner circumferential side, that is, the main lip chamber S3 side to the outer circumferential side, that is, the open chamber S4 side. The valve body 73 having a shape corresponding to each end 72b of the lip piece 72 is formed between the adjacent lip pieces 72. It is provided so that it can freely open and close between adjacent lip pieces 72.

  Also in FIG. 12A, the rod guide 40 is indicated by a two-dot chain line, as in FIG. 8B described in the second embodiment. The rod guide 40 is configured in the same manner as in the second embodiment.

The check lip 71 in the sealing device of the third embodiment is formed in an annular shape like the check lip 15 in the first embodiment described above, and includes a plurality of lip pieces 72 in the circumferential direction. The lip piece 72 is provided such that circumferential end portions 72b are separated from each other.
An end 72b in the circumferential direction of the lip piece 72 is formed to include an end first surface 72e, an end second surface 72f, and an end third surface 72g. The end first surface 72e is provided substantially perpendicular to the inner peripheral surface 72c so as to face another adjacent lip piece 72 at the end 72b and extends toward the outer peripheral side. The end second surface 72f is provided substantially perpendicular to the end first surface 72e so as to face the outer peripheral side, and extends in the circumferential direction. The end third surface 72g is provided substantially perpendicular to the end second surface 72f so as to face another adjacent lip piece 72, extends toward the outer peripheral side, and continues to the outer peripheral surface 72d. It is formed as follows.
By forming the end portion 72b in this way, each of the two lip pieces 72 adjacent in the circumferential direction is adjacent from the inner peripheral side, that is, the main lip chamber S3 side toward the outer peripheral side, that is, the open chamber S4 side. The distance from the lip piece 72 is increased.

  A valve body 73 is provided between the adjacent lip pieces 72. The valve body 73 includes an end first surface 73e, an end second surface 73f, and an end third surface 73g at the end in the circumferential direction. The end first surface 73e is provided substantially perpendicular to the inner peripheral surface 73c so as to face the adjacent lip piece 72 and extends toward the outer peripheral side. The end second surface 73f is provided substantially perpendicular to the end first surface 73e so as to face the inner peripheral side, and extends in the circumferential direction. The third end surface 73g is provided substantially perpendicular to the second end surface 73f so as to face the adjacent lip piece 72, extends toward the outer peripheral side, and continues to the outer peripheral surface 73d. Is formed.

In the third embodiment, the lip piece 72 and the valve body 73 are formed by cutting the check lip 71 from the tip 71a toward the base 71b. Therefore, in a state where no force is applied from the outside, the valve body 73 is fitted and accommodated between the adjacent lip pieces 72, and the space between the adjacent lip pieces 72 is closed by the valve body 73. Is provided.
That is, each of the end first surface 72e, the end second surface 72f, and the end third surface 72g of the lip piece 72, the end first surface 73e, the end second surface 73f of the valve body 73, and Each of the end third surfaces 73g faces and is in close contact with each other. Further, the surface of the tip 72a, the inner peripheral surface 72c, and the outer peripheral surface 72d of the lip piece 72, and the surface of the tip 73a, the inner peripheral surface 73c, and the outer peripheral surface 73d of the valve body 73 are mutually connected. It is continuous.
Thus, the shape of the valve body 73 corresponds to each end 72 b of the lip piece 72. In the end 72b of the lip piece 72 where the separation dimension is changed, the lip piece 72 and the valve body 73 overlap in the circumferential direction so that the valve body 73 covers the lip piece 72 from the outer peripheral side. It has become.

The length of the valve body 73 in the circumferential direction is formed to be shorter than the length of the lip piece 72 in the circumferential direction. For this reason, when the force which goes to an outer peripheral side acts from the inner peripheral side, the valve body 73 has a structure that bends to the outer peripheral side more easily than the lip piece 72.
Therefore, when the pressure on the inner peripheral side of the check lip 71, that is, the pressure in the main lip chamber S3 rises, the valve body 73 preferentially bends so that the space between the adjacent lip pieces 72 apart from the lip piece 72 is increased. Opened. Thus, the valve body 73 is provided so that it can open and close between the adjacent lip pieces 72.

  Since the valve body 73 is provided between the adjacent lip pieces 72 so as to be fitted and accommodated as described above, the check lip 71 has a structure that is not spaced apart in the circumferential direction as a whole. It has become.

  The shape of the check lip 71 shown in FIG. 12 (a) is the same as that before the sealing device is attached. When the sealing device is attached, the check lip 71 is not shown in FIG. 12 (a). In accordance with the shape of the stepped portion 40f of the rod guide 40 indicated by the dotted line, the rod guide 40 is provided to bend toward the outer peripheral side.

  The configuration of other parts of the hydraulic shock absorber according to the third embodiment is the same as that of the hydraulic shock absorber 1 according to the first embodiment and the sealing device 10 provided therein.

  Next, the action of the hydraulic shock absorber sealing device provided with the check lip 71 will be described.

  When the piston rod protrudes outward and the pressure in the main lip chamber S3 becomes higher than the pressure in the open chamber S4, the differential pressure acts in a direction to separate the check lip 71 from the step portion 40f of the rod guide 40. At this time, in each of the two lip pieces 72 adjacent in the circumferential direction, the end portions 72b in the circumferential direction are separated from each other, and the valve body 73 bends to the outer peripheral side more easily than the lip piece 72 as described above. Since the adjacent lip pieces 72 are provided so as to be openable and closable, the valve body 73 bends away from the lip piece 72 toward the outer peripheral side as shown in FIG. Thereby, a gap G3 is formed between the adjacent lip pieces 72, and the main lip chamber S3 and the open chamber S4 communicate with each other.

  The main lip chamber S3 and the open chamber S4 communicate with each other so that the pressure in the main lip chamber S3 and the pressure in the open chamber S4 are substantially equal, and the pressure in the main lip chamber S3 and the pressure in the open chamber S4 are reduced. When the differential pressure becomes equal to or less than a certain level, the valve body 73 is restored to a stationary state in which it is fitted and accommodated between the adjacent lip pieces 72 by the elastic restoring force of the check lip 71.

  When the piston rod is inserted into the inner cylinder and the pressure in the open chamber S4 becomes a reverse pressure state in which the pressure in the open lip chamber S3 is higher than the pressure in the main lip chamber S3, the differential pressure causes the check lip 71 to move in the direction of the piston rod. Acts as follows. At this time, the tip 71a of the check lip 71 is pressed against the stepped portion 40f of the rod guide 40, and at the portion where the lip piece 72 and the valve body 73 of the end 72b of the lip piece 72 overlap in the circumferential direction, The valve body 73 located on the side is pressed against each of the two adjacent lip pieces 72 located on the inner peripheral side. Thereby, at the time of back pressure, the check lip 71 partitions the main lip chamber S3 and the open chamber S4.

  Next, the effect of the hydraulic shock absorber sealing device according to the third embodiment will be described.

  According to the configuration as described above, each of the two lip pieces 72 adjacent to each other in the circumferential direction has the circumferential ends 72b separated from each other, and the valve body 73 is adjacent between the adjacent lip pieces 72. It is provided so that the space between the lip pieces 72 can be opened and closed. For this reason, when a fluid such as hydraulic oil flows into the main lip chamber S3 and the pressure in the main lip chamber S3 increases and becomes higher than the pressure in the open chamber S4, the increased pressure in the main lip chamber S3 The valve body 73 moves away from the lip piece 72 toward the outer peripheral side. At this time, each of the two lip pieces 72 adjacent to each other in the circumferential direction is formed so that the distance from the adjacent lip piece 72 increases from the inner peripheral side toward the outer peripheral side. Since the shape corresponds to each end 72 b of 72, the valve body 73 is easily separated from the lip piece 72. As a result, the fluid in the main lip chamber S3 easily flows into the reservoir chamber via the gap G3 formed by opening the lip piece 72 adjacent to the valve body 73. Therefore, the valve opening pressure of the check lip 71 can be effectively reduced.

  In addition, each of the two lip pieces 72 adjacent in the circumferential direction is formed so that the distance from the adjacent lip piece 72 increases from the inner peripheral side toward the outer peripheral side, and the valve body 73 is formed of the lip piece 72. It has a shape corresponding to each end 72b. For this reason, the lip piece 72 and the valve body 73 overlap in the circumferential direction at the end 72b of the lip piece 72 where the separation dimension is changed, and the valve body 73 is lip piece 72 from the outer peripheral side. To cover. Here, when the pressure in the open chamber S4 becomes higher than the pressure in the main lip chamber S3 and becomes a reverse pressure, the valve body 73 located on the outer peripheral side in the overlapped portion has the pressure in the open chamber S4. Is pressed against each of the two adjacent lip pieces 72 located on the inner peripheral side, and the space between the adjacent lip pieces 72 is closed to partition the main lip chamber S3 and the open chamber S4. Therefore, it is possible to effectively suppress the backflow of fluid such as hydraulic oil or gas at the time of reverse pressure.

(Modification of the third embodiment)
Next, a modified example of the hydraulic shock absorber sealing device shown as the third embodiment will be described with reference to FIG. 13A is a cross-sectional view of the check lip of the hydraulic shock absorber sealing device according to the present modification, FIG. 13B is a perspective view of the vicinity of portion E in FIG. 13A, and FIG. It is a perspective view at the time of valve opening of the E part vicinity of Fig.13 (a).
The sealing device of the present modification is different from the sealing device in the third embodiment in the shapes of the end portion 82b of the lip piece 82 and the valve body 83.

In this modification, the end 82b in the circumferential direction of the lip piece 82 includes an end surface 82h. The end surface 82h is provided so as to form an acute angle with respect to the inner peripheral surface 82c, extends toward the outer peripheral side, and is formed to connect with the outer peripheral surface 82d at an obtuse angle.
By forming the end portion 82b in this way, each of the two lip pieces 82 adjacent in the circumferential direction is adjacent from the inner peripheral side, that is, the main lip chamber S3 side toward the outer peripheral side, that is, the open chamber S4 side. The distance from the lip piece 82 is increased.

The valve body 83 includes an end surface 83h at the end in the circumferential direction. The end surface 83h is provided so as to form an obtuse angle with respect to the inner peripheral surface 83c, extends toward the outer peripheral side, and is formed to connect with the outer peripheral surface 83d at an acute angle.
Thus, the shape of the valve body 83 corresponds to each end portion 82 b of the lip piece 82. In the portion of the end portion 82b of the lip piece 82 where the separation dimension is changed, the lip piece 82 and the valve body 83 overlap in the circumferential direction so that the valve body 83 covers the lip piece 82 from the outer peripheral side. It has become.

  It goes without saying that the hydraulic shock absorber sealing device provided with the check lip 81 in the present modification works in the same manner as the hydraulic shock absorber sealing device provided with the check lip 71 in the third embodiment and has the same effect. .

(Fourth embodiment)
Next, a hydraulic shock absorber sealing apparatus according to a fourth embodiment of the present invention will be described. 14A is a cross-sectional view of the check lip of the hydraulic shock absorber sealing device according to the fourth embodiment, FIG. 14B is a perspective view of the vicinity of the portion F in FIG. 14A, and FIG. ) Is a perspective view when the valve is opened in the vicinity of the portion F in FIG.
In the fourth embodiment, the check lip 91 is cut at an angle with respect to a plane passing through the central axis O of the check lip 91 from the tip 91a toward the base 91b at a plurality of positions in the circumferential direction. Thus, a plurality of lip pieces 92 are formed.

  Also in FIG. 14A, the rod guide 40 is indicated by a two-dot chain line, as in FIG. 8B described in the second embodiment. The rod guide 40 is configured in the same manner as in the second embodiment.

The check lip 91 in the sealing device of the fourth embodiment is formed in an annular shape like the check lip 15 in the first embodiment described above, and at least its tip 91a is circumferentially formed by forming a cut 91d. It is divided into a plurality of lip pieces 92.
The notches 91d are formed at a plurality of positions in the circumferential direction so as to be cut at an angle with respect to a plane passing through the central axis O of the check lip 91 from the tip 91a toward the base 91b. Accordingly, as shown in FIG. 14B, one of the adjacent lip pieces 92A and 92B divided by the notch 91d is the same as the lip piece 92A on the inner peripheral side of the end portion 92b. It is located on the inner side of the end portion 92b and is an inner peripheral lip piece 92B. In the other lip piece 92A, the outer peripheral side of the end 92b is positioned outside the end 92b of the adjacent lip piece 92B, forming the outer peripheral lip piece 92A.
The end surfaces 92h of the inner lip piece 92B and the outer lip piece 92A are angled with respect to a plane passing through the central axis O of the check lip 91 so as to face the outer peripheral side and the inner peripheral side, respectively. Are provided opposite to each other.

  In this way, the inner peripheral lip piece 92B extends toward the outer peripheral lip piece 92A adjacent in the circumferential direction on the inner peripheral side to support the outer peripheral lip piece 92A from the inner peripheral side. The lip piece 92A extends toward the inner peripheral lip piece 92B on the outer peripheral side and covers the inner peripheral lip piece 92B from the outer peripheral side. That is, the lip pieces 92A and 92B overlap in the circumferential direction at the notch 91d.

In the fourth embodiment, the lip piece 92 is formed by cutting the check lip 91 from the tip 91a toward the base 91b. Therefore, in a state where no force is applied from the outside, the adjacent lip pieces 92 are provided in close contact with each other on the end surface 92h.
With the above-described configuration, the check lip 91 has a structure in which no interval is provided in the circumferential direction as a whole.

  The shape of the check lip 91 shown in FIG. 14 (a) is the same as that before the sealing device is attached. When the sealing device is attached, the check lip 91 is not shown in FIG. 14 (a). In accordance with the shape of the stepped portion 40f of the rod guide 40 indicated by the dotted line, the rod guide 40 is provided to bend toward the outer peripheral side.

  The configuration of other parts of the hydraulic shock absorber according to the fourth embodiment is the same as that of the hydraulic shock absorber 1 according to the first embodiment and the sealing device 10 provided therein.

  Next, the action of the hydraulic shock absorber sealing device provided with the check lip 91 will be described.

  When the piston rod protrudes outward and the pressure in the main lip chamber S3 becomes higher than the pressure in the open chamber S4, the differential pressure acts in a direction to separate the check lip 91 from the step portion 40f of the rod guide 40. At this time, the check lip 91 is cut from the tip 91a toward the base portion 91b at a plurality of positions in the circumferential direction to form a plurality of lip pieces 92. For this reason, as shown in FIG. 14 (c), the end 92b of the outer lip piece 92A provided so as to cover the other lip piece 92 from the outer peripheral side is the inner lip. It bends to the outer peripheral side so as to be separated from the piece 92B. Thus, by opening the notch 91d between the lip pieces 92, a gap G4 is formed between the adjacent lip pieces 92, and the main lip chamber S3 and the open chamber S4 communicate with each other.

  The main lip chamber S3 and the open chamber S4 communicate with each other so that the pressure in the main lip chamber S3 and the pressure in the open chamber S4 are substantially equal, and the pressure in the main lip chamber S3 and the pressure in the open chamber S4 are reduced. When the differential pressure is below a certain level, the outer peripheral lip piece 92A is brought into contact with the end surface 92h of the inner peripheral lip piece 92B by the elastic restoring force of the check lip 91. Is restored to the correct state.

  When the piston rod is inserted into the inner cylinder and the pressure in the open chamber S4 becomes a reverse pressure state in which the pressure in the open lip chamber S3 is higher than the pressure in the main lip chamber S3, the differential pressure causes the check lip 91 to move in the direction of the piston rod. Acts as follows. At this time, the leading end 91a of the check lip 91 is pressed against the stepped portion 40f of the rod guide 40, and the outer lip piece 92A is in the cut portion 91d where the two lip pieces 92A and 92B overlap in the circumferential direction. The end 92b is pressed against the end 92b of the inner lip piece 92B. Thereby, the check lip 91 divides the main lip chamber S3 and the open chamber S4 during back pressure.

  Next, effects of the hydraulic shock absorber sealing device according to the fourth embodiment will be described.

  According to the above configuration, the check lip 91 is cut from the distal end 91a toward the base portion 91b at a plurality of positions in the circumferential direction to form a plurality of lip pieces 92. For this reason, when a fluid such as hydraulic oil flows into the main lip chamber S3 and the pressure in the main lip chamber S3 increases and becomes higher than the pressure in the open chamber S4, the increased pressure in the main lip chamber S3. As a result, the notch 91d between the lip pieces 92 is opened. Thereby, the fluid in the main lip chamber S3 easily flows to the reservoir chamber via the open chamber S4. Therefore, the valve opening pressure of the check lip 91 can be effectively reduced.

  Further, the above-mentioned cut 91 d is cut at an angle with respect to a plane passing through the central axis O of the check lip 91. For this reason, of the two adjacent lip pieces 92A, 92B, the end surface 92h, which is the cut end surface of one lip piece 92B, faces the outer peripheral side with respect to the circumferential direction, and the other lip piece facing this. The end surface 92h of 92A faces the inner circumferential side from the circumferential direction, and the lip piece 92B is overlapped in the circumferential direction at the notch 91d so as to cover from the outer circumferential side. Here, when the pressure in the open chamber S4 becomes higher than the pressure in the main lip chamber S3 and becomes a reverse pressure, the lip piece 92A located on the outer peripheral side in the overlapped portion has the pressure in the open chamber S4. Is pressed against the lip piece 92B located on the inner peripheral side to partition the main lip chamber S3 and the open chamber S4. Therefore, it is possible to effectively suppress the backflow of fluid such as hydraulic oil or gas at the time of reverse pressure.

  The sealing device for a hydraulic shock absorber according to the present invention is not limited to the above-described embodiments and modifications described with reference to the drawings, and various other modifications can be considered within the technical scope thereof. .

For example, in each of the first embodiment and each modification of the first embodiment, a total of four cuts 15d and 61d are provided as shown for the cut 15d in the first embodiment in FIG. The check lips 15, 21, 31, 61 are formed with four lip pieces 16, 62. Similarly, in the second embodiment and the modified example of the second embodiment, as shown in FIGS. 8A and 10A, the check lips 41 and 51 have four lips in the circumferential direction. It consisted of pieces 42 and 52. However, in each embodiment and each modification, the number of lip pieces is not limited to this, and may be less than 4 or 5 or more. In order to realize an appropriate valve opening pressure, the number of the lip pieces, that is, the cuts and gaps formed between the lip pieces may be arbitrarily changed.
The same applies to the third embodiment, its modified examples, and the fourth embodiment. By adjusting the number and size of the valve bodies 73 and the number of cuts 91d, the check lips 71, 81, 91 can be adjusted at a desired pressure. Can be set to open.

  In addition to this, the configurations described in the above embodiments and modifications can be selected or changed to other configurations as appropriate without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Hydraulic buffer 2 Inner cylinder 2a Open end 3 Outer cylinder 3a Open end 4 Piston rod 5,20,30,40 Rod guide 5g, 20a, 30a Protruding part 5h, 20b, 30b Outer peripheral surface 10,60 Sealing device 11 Metal Rings 15, 21, 31, 41, 51, 61, 71, 81, 91 Check lips 15d, 61d, 91d Notches 15a, 41a, 51a, 71a, 91a Tips 15b, 41b, 51b, 71b, 91b Bases 16, 42, 52, 62, 72, 82, 92 Lip piece 42a Extending portion 53 Outer peripheral side check lips 72b, 82b, 92b End portions 73 and 83 in the circumferential direction Valve body S1 Oil chamber S2 Reservoir chamber S3 Main lip chamber S4 Open chamber G2 Gap O Axis, center axis

Claims (6)

A sealing device for a double cylinder type hydraulic shock absorber,
The hydraulic shock absorber closes an inner cylinder, an outer cylinder covering the inner cylinder, a piston rod provided in the inner cylinder so as to be movable in the axial direction, and open ends of the inner cylinder and the outer cylinder, A rod guide that pivotally supports the piston rod;
A metal ring provided on the opposite side of the open end of the inner cylinder of the rod guide;
The metal ring is provided on the side facing the rod guide so as to contact the rod guide, and is formed between the inner cylinder and the outer cylinder from a space between the rod guide and the metal ring. With an annular check lip that allows only fluid flow towards the reservoir chamber,
The check lip is a sealing device for a hydraulic shock absorber formed of a plurality of lip pieces in the circumferential direction. The rod guide includes an annular projecting portion that projects to the side facing the metal ring,
The check lip is in contact with the outer peripheral surface of the protrusion, and is cut from the tip toward the base at a plurality of positions in the circumferential direction to form the plurality of lip pieces. The sealing device for hydraulic shock absorbers as described. The lip piece includes, at one end in the circumferential direction, an extending portion that extends to the outer peripheral side of the other lip piece adjacent to the one end side and overlaps the other lip piece,
2. The sealing device for a hydraulic shock absorber according to claim 1, wherein the extending portion is formed thinner than an overlapping portion of the other lip piece. Between the two lip pieces adjacent in the circumferential direction, a gap is formed by separating each end side,
On the outer peripheral side of the two adjacent lip pieces, an outer peripheral side check lip that overlaps each of the two adjacent lip pieces across the gap is formed,
The sealing device for a double cylinder type hydraulic shock absorber according to claim 1, wherein the outer peripheral side check lip is formed thinner than the lip piece. Each of the two lip pieces adjacent to each other in the circumferential direction is formed such that end portions in the circumferential direction are separated from each other, and a separation dimension from the adjacent lip piece is increased from the inner peripheral side toward the outer peripheral side. ,
2. A valve body having a shape corresponding to the end of each of the lip pieces is provided between the adjacent lip pieces so as to be openable and closable between the adjacent lip pieces. A double cylinder type hydraulic shock absorber sealing device according to claim 1.   The check lip is cut at a plurality of positions in the circumferential direction at an angle with respect to a plane passing through the central axis of the check lip from the tip toward the base to form the plurality of lip pieces. The double cylinder type hydraulic shock absorber sealing device according to claim 1.

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