JP2012077886A - Fluid pressure buffer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the workability of an assembling work of a front fork by preventing air bubbles from mixing in an operative chamber with respect to an improvement in a fluid pressure buffer such as a front fork.SOLUTION: The fluid pressure buffer includes a buffer body including an outer tube 1 and an inner tube 2, a damper 3 housed inside the buffer body to generate a prescribed damping force, and a reservoir chamber R formed between the buffer body and a damper 3 to reserve a working fluid. The damper 3 includes a cylinder 4 for housing the working fluid, and a piston 6 for partioning an inside of the cylinder 4 into an extending-side working chamber P1 and a pressurizing-side working chamber P2. In such a fluid pressure buffer, there is provided a flow path L1 for allowing the extending-side working chamber P1 and the reservoir chamber R to consistently communicate with each other. This flow path L1 is formed in a direction not perpendicular to a fluid surface O.

Description

  The present invention relates to an improvement in a fluid pressure shock absorber such as a front fork that suspends a front wheel of a motorcycle.

  Various proposals have been made for fluid pressure shock absorbers so far. For example, the fluid pressure shock absorber is used as a suspension device such as a front fork or a rear cushion unit that suspends a wheel of a two-wheeled vehicle and attenuates road surface vibration input to the wheel. The

  Patent Document 1 discloses a configuration of a conventional front fork, which includes an outer tube and an inner tube that is slidably inserted into the outer tube. A fork body is provided. The outer tube is connected to the vehicle body side, and the inner tube is connected to the wheel side via an attachment member to constitute an inverted front fork.

  The front fork is housed in the fork body and generates a predetermined damping force, the damper is housed in the fork body and generates a predetermined damping force, the fork body, and the damper. And a reservoir chamber formed between the two. A working fluid is stored in the reservoir chamber, and a gas is accommodated upward through the liquid surface to form an air chamber.

  The damper includes a cylinder that accommodates a working fluid therein and is fixed to the axial center portion of the inner tube, and a rod that is fixed to the axial center portion of the outer tube and protrudes into and out of the cylinder. A piston that divides the inside of the cylinder into an extension side working chamber and a pressure side working chamber is held at the tip of the rod.

  The extension side working chamber and the pressure side action chamber are immersed in the working fluid accommodated in the reservoir chamber, and the extension side working chamber formed on the rod side is a rod guide screwed into the head portion of the cylinder. Is separated from the reservoir chamber. On the other hand, the pressure side working chamber formed on the piston side is partitioned from the reservoir chamber by a base member screwed into the bottom portion of the cylinder.

  The piston communicates between the extension side working chamber and the pressure side working chamber and includes a communication path including damping force generating means for generating a predetermined damping force when the working fluid passes, and the extension side working chamber and the pressure side working chamber. And a communication passage provided with a check valve that allows only the working fluid to move from the pressure side working chamber to the extension side working chamber.

  The base member communicates between the pressure side working chamber and the reservoir chamber, and communicates with the communication path including damping force generating means for generating a predetermined damping force when the working fluid passes, and similarly communicates the pressure side working chamber and the reservoir chamber. And a communication passage having a check valve that only allows the working fluid to move from the reservoir chamber to the extension chamber.

  With the above configuration, the damping force generating means provided on the piston generates the main extension side damping force, the damping force generating means provided on the base member generates the main compression side damping force, and the front fork is connected to the fork body. This is useful in that the stretching motion can be attenuated.

  However, depending on the setting of the damping force generating means provided on the base member in the front fork, when the fork main body contracts due to the input of road surface vibration, the expansion side working chamber becomes lower than the reference pressure and the suction force is applied to the piston. There is a risk that the desired damping force on the compression side cannot be obtained, or that the piston is pulled back by the suction force when the process moves to the next expansion step, leading to a deterioration in riding comfort of the two-wheeled vehicle.

  Therefore, in order to solve the above-mentioned problem, the applicant opens a flow path L10 that always communicates the extension side working chamber P1 and the reservoir chamber R with the rod guide 700 in the axial direction, as shown in FIG. Insufficient working fluid in the expansion side working chamber P1 is compensated from the reservoir chamber R via the flow path L10, and the inside of the expansion side working chamber P1 is kept at the same pressure as the reservoir chamber (hereinafter referred to as reservoir pressure) even during the compression process. I created a front fork that allows me to keep it.

JP 2009-275832 A

  In the front fork as the conventional fluid pressure buffer, by providing the flow path L10, it is possible to prevent the extension side working chamber from becoming lower than the reference pressure, and the flow path L10 is connected to the rod. Although it is useful in that the flow path L10 can be easily formed because the guide is opened in the axial direction, the following problems may be pointed out.

  That is, the reservoir chamber R side opening in the flow path L10 faces the liquid level of the reservoir chamber, and the flow path L10 is formed perpendicular to the liquid level, so that the extension side working chamber P1 is pressurized. Then, the working fluid jetted from the flow path L10 comes into direct contact with the liquid surface, and bubbles are involved in the working fluid. And the working fluid containing a bubble flows in into the cylinder 4 via the flow path L10 at the time of a shrinkage | contraction process, and the said bubble becomes a hindrance from obtaining desired damping force.

  Further, in the assembly operation process of the front fork, the working fluid is injected while moving the piston, so that the working fluid is jetted from the flow path L10 in the vertical direction, and workability is poor.

  Then, the objective of this invention is providing the fluid pressure buffer which solves the said malfunction in the fluid pressure buffer provided with the said flow path.

  The first means for solving the above-mentioned problem is that a shock absorber body comprising an outer tube, an inner tube slidably inserted into the outer tube, and a predetermined body accommodated in the shock absorber body. A damper that generates a damping force; and a reservoir chamber formed between the shock absorber main body and the damper. A working fluid is stored in the reservoir chamber, and a gas flows upward through the liquid level. The damper includes a cylinder that stores the working fluid, a rod that moves in the cylinder in the axial direction along with expansion and contraction of the shock absorber body, and an extension side that is held by the rod and extends in the cylinder. A piston that is divided into a working chamber and a pressure-side working chamber; and is formed in an annular shape so as to be in sliding contact with the outer periphery of the rod and attached to the head portion of the cylinder, so that the extension-side working chamber and the reservoir chamber The rod guide is immersed in the working fluid in the reservoir chamber, and the damper has a flow path that always connects the extension side working chamber and the reservoir chamber. Thus, the flow path is formed in a direction that is not orthogonal to the liquid surface.

  The second means for solving the above-mentioned problems includes a shock absorber body comprising an outer tube, an inner tube slidably inserted into the outer tube, and a predetermined body contained in the shock absorber body. A damper that generates a damping force; and a reservoir chamber formed between the shock absorber main body and the damper. A working fluid is stored in the reservoir chamber, and a gas flows upward through the liquid level. The damper includes a cylinder that stores the working fluid, a rod that moves in the cylinder in the axial direction along with expansion and contraction of the shock absorber body, and an extension side that is held by the rod and extends in the cylinder. A piston that is divided into a working chamber and a pressure-side working chamber; and is formed in an annular shape so as to be in sliding contact with the outer periphery of the rod and attached to the head portion of the cylinder, so that the extension-side working chamber and the reservoir chamber The rod guide is immersed in the working fluid in the reservoir chamber, and the damper has a flow path that always connects the extension side working chamber and the reservoir chamber. The flow path is formed in the rod guide perpendicular to the liquid surface, and includes a wall plate that closes a part of the reservoir chamber side opening in the flow path.

  According to the present invention, since the working fluid that jets from the flow path that always communicates between the extension side chamber and the reservoir chamber does not come into direct contact with the liquid surface, it is possible to suppress entrainment of bubbles in the working fluid. It becomes.

  In addition, since the working fluid does not jet in the liquid surface direction, it is possible to improve the workability of the assembly work of the fluid pressure shock absorber.

It is a longitudinal cross-sectional view which shows in principle the front fork which is a fluid pressure buffer which concerns on one embodiment of this invention. It is a side view which cuts and shows the right half of the front fork which is a fluid pressure buffer which concerns on one embodiment of this invention. It is a partial expanded longitudinal cross-sectional view which shows the flow-path periphery part in the front fork which is a fluid pressure buffer which concerns on one embodiment of this invention. (A) It is a partial expanded longitudinal cross-sectional view which shows the 1st modification of the flow path of FIG. (B) It is a partial expanded longitudinal cross-sectional view which shows the 2nd modification of the flow path of FIG. It is a partial expanded longitudinal cross-sectional view which shows the flow-path periphery part in the front fork which is the conventional fluid pressure buffer.

  A fluid pressure shock absorber according to an embodiment of the present invention will be described below with reference to the drawings. The same reference numerals given throughout the several drawings indicate the same or corresponding parts.

  The fluid pressure shock absorber according to the present embodiment is a front fork that suspends a front wheel of a motorcycle and attenuates road surface vibration input to the front wheel due to unevenness of the road surface.

  Although not shown, the front fork is composed of a pair of left and right fork members whose upper end portions are connected by a bridge mechanism, and the lower ends of the fork members are connected to the axles of the front wheels and suspended so as to sandwich the front wheels.

  Further, although not shown, the bridge mechanism has a steering shaft coupled to a handle, and the front mechanism can be steered by operating the handle by including the configuration.

  As shown in FIGS. 1 and 2, the fork member includes a fork body that is a shock absorber body including an outer tube 1 and an inner tube 2 that is slidably inserted into the outer tube 1.

  The fork member includes a damper 3 that is housed in the fork body and generates a predetermined damping force, and a reservoir chamber R that is formed between the fork body and the damper 3. In this reservoir chamber R, working fluid is accommodated, and gas is accommodated upward via the liquid level O.

  The damper 3 includes a cylinder 4 that contains a working fluid, a rod 5 that moves in the cylinder 4 in the axial direction as the fork main body expands and contracts, and an extension side action that is held by the rod 5 and moves inside the cylinder 4. A piston 6 that is divided into a chamber P1 and a pressure-side working chamber P2, and is formed in an annular shape so that its inner periphery is slidably contacted with the outer periphery of the rod 5, and is mounted on the head portion of the cylinder 4 so that the extension-side working chamber P1 and the reservoir And a rod guide 7 partitioning the chamber R.

  The rod guide 7 is immersed in the working fluid in the reservoir chamber R, and the damper 3 includes a flow path L1 in which the extension side working chamber P1 and the reservoir chamber R are always in communication. , Formed in a direction not orthogonal to the liquid level O.

  Hereinafter, each component of the front fork will be described in detail with reference to FIGS. FIG. 1 is a longitudinal sectional view showing in principle the front fork according to the present embodiment. FIG. 2 is a side view specifically showing the front fork according to the present embodiment, in which the right half is cut away. FIG. 3 is a partially enlarged longitudinal sectional view showing the periphery of the flow path L1 in the front fork according to the present embodiment, and FIG. 4 shows a modification of the flow path L1.

  The fork main body composed of the outer tube 1 and the inner tube 2 constitutes an inverted front fork in which the outer tube 1 is disposed on the vehicle body side and the inner tube 2 is disposed on the wheel side.

  The fork main body has its upper and lower ends sealed with a cap member 10 and a bottom member 20, respectively.

  Specifically, as shown in FIG. 2, the bottom member 20 includes a connecting portion 21 that is connected to the axle, and a substantially cylindrical support portion 22 that supports the inner tube 2 and the cylinder 4.

  The inner tube 2 is screwed to the support portion 22 in the inner periphery of the upper end portion 22a in the figure, and the cylinder 4 is screwed to the inner periphery of the small diameter portion 22b in which the inner periphery is smaller in diameter than the upper end portion 22a. While being supported, a reduced diameter portion 22c is formed on the lower side of the small diameter portion 22b in the figure with an inner circumference formed to be smaller in diameter than the small diameter portion 22b.

  A base rod holding member 24 for supporting the base rod 23 is fitted into the inner periphery of the reduced diameter portion 22c, and the base member 8 is attached to the upper end portion of the base rod 23 in the drawing via a center rod 25. Retained.

  By providing the base rod 23, the base member 8 can be inserted from the lower side of the cylinder 4 in the figure and arranged at a predetermined position. The center rod 25 is provided with a flange portion 25a on the back side of the base member 8, and the space between the outer periphery of the flange portion 25a and the cylinder 4 is sealed by a seal member 25c. The air chamber A can be formed on the lower end side of the inner flange portion 25a, and the front fork can be reduced in weight.

  Further, a seal member (not shown) is sealed between the inner periphery of the upper end portion 22a of the bottom member 20 and the outer periphery of the inner tube 2 and between the inner periphery of the cylinder 4 and the outer periphery of the base member holding portion 24. Therefore, the working fluid accommodated in the fork main body does not leak out.

  The configuration of the bottom member 20 is not limited to the above. For example, the base member 8 may be fixed to the bottom member 20 without providing the air chamber A, and the configuration can be selected as appropriate. .

  The fork body accommodates therein a suspension spring S that absorbs road vibration and a damper 3 that generates a predetermined damping force. By providing the structure, the front fork can attenuate the expansion and contraction movement of the fork main body due to the absorption of the road surface vibration by the suspension spring S by the damper 3, and the riding comfort of the motorcycle can be improved. Become.

  Specifically, as shown in FIG. 2, the suspension spring S is interposed between a cylindrical case 11 held by the cap member 10 and a rod guide 7 that closes the upper end opening of the cylinder 4 in the drawing. The fork body is always urged in the extension direction.

  The case 11 can be moved in the axial direction by rotating an adjuster 10a attached to the cap member 10, whereby an initial load applied to the suspension spring S can be arbitrarily set.

  The reservoir chamber R formed between the fork main body and the damper 3 stores working fluid, and gas is sealed upward through the liquid level O to form an air chamber G.

  The air chamber G expands and contracts with the expansion and contraction of the fork main body, generates a predetermined spring reaction force, and functions as an air spring. Although not shown, the internal pressure of the air chamber G can be adjusted by an air valve provided in the cap member 10.

  Further, the liquid level O is immersed in the working fluid stored in the reservoir chamber R even when the fork main body is at its maximum extension where the liquid level O is the lowest when the rod guide 7 that closes the upper end opening of the cylinder 4 in the drawing. It is set as follows.

  As shown in FIGS. 1 and 2, the damper 3 housed in the fork main body includes a cylinder 4 that stands on the axial center of the inner tube 2 and a rod that is held by the cap member 10 and protrudes into and out of the cylinder 4. 5 and a piston 6 that is held at the tip of the rod 5 via a tip member 50 (FIG. 2) and slidably contacts the outer periphery of the cylinder 4.

  A rod guide 7 which is formed in an annular shape and slidably supports the rod 5 on the inner periphery thereof is attached to the upper end portion (head portion) of the cylinder 4 in the figure. On the other hand, the lower end side of the cylinder 4 in the figure is supported by a base rod 23 while being closed by a flange 25a of a center rod 25 that closely contacts the outer periphery of the cylinder 4 as shown in FIG. It communicates with the reservoir chamber R via the member 8.

  A space formed between the rod guide 7 and the base member 8 in the cylinder 4 is filled with a working fluid to form a working chamber. The working chamber is divided into upper and lower parts in the figure by the piston 6, and an extension working chamber P1 is formed on the rod 5 side, and a pressure side working chamber P2 is formed on the piston 6 side. Further, the working chambers (P1, P2) are immersed in the working fluid accommodated in the reservoir chamber R.

  As shown in FIG. 1, the piston 6 communicates with the extension side working chamber P1 and the pressure side working chamber P2 and includes a communication passage 60 provided with a damping force generating means V1 that generates a predetermined damping force when the working fluid passes through. Similarly, it has a communication passage 61 including a check valve C2 that allows the working fluid P1 and the pressure working chamber P2 to communicate with each other and allows only the working fluid to move from the pressure working chamber P2 to the stretching working chamber P1.

  The base member 8 communicates with the pressure-side working chamber P2 and the reservoir chamber R, and also includes a communication passage 80 including damping force generating means V2 that generates a predetermined damping force when the working fluid passes, and the pressure-side working chamber P2. And a communication passage 81 provided with a check valve C1 that allows the working fluid to only move from the reservoir chamber R to the pressure side working chamber P2.

  By providing the above configuration, it becomes possible to supplement the working fluid that is excessive or insufficient in the working chamber of the rod 5 from the reservoir chamber R through the base member 8.

  The valve structures of the piston 6 and the base member 8 can be appropriately selected. FIG. 2 shows a part of a specific form of the valve structure.

  FIG. 2 shows a communication path 60 formed in the piston 6 and having the damping force generation means V1, and a communication path 80 formed in the base member 8 and having the damping force generation means V2.

  The communication path 60 of the piston 6 displayed in FIG. 2 is always in communication with the extension side working chamber P1. The damping force generating means V1 provided in the piston 6 is a laminated leaf valve facing the opening on the pressure side working chamber P2 side of the communication path 60, and the inner peripheral portion is fixed to the piston 6 via the nut N1. The outer peripheral part is separated from and seated on the seating surface of the piston 6 to open and close the communication path 60.

  In other words, in the present embodiment, the laminated leaf valve (damping force generating means V1) allows only the working fluid to move from the expansion side working chamber P1 to the pressure side working chamber P2, and the working fluid is put on the laminated leaf valve. A predetermined damping force, that is, an extension-side damping force, is generated when the outer peripheral portion is pushed open and flows into the compression-side action chamber P2.

  On the other hand, the communication path 80 of the base member 8 displayed in FIG. 2 always communicates with the compression side working chamber P2. The damping force generating means provided in the base member 8 is a leaf valve facing the reservoir chamber R side opening of the communication path 80, and the inner peripheral portion is fixed to the base member 8 via the nut N2 and the outer peripheral portion. The part opens and closes on the seat surface of the base member 8 to open and close the communication path 80. A valve stopper 83 for restricting the opening amount of the leaf valve is provided on the back side of the leaf valve.

  In other words, in the present embodiment, the leaf valve (damping force generating means V2) only allows the working fluid to move from the pressure side working chamber P2 to the reservoir chamber R, and the working fluid that has pushed the leaf valve open is A predetermined damping force, that is, a compression-side damping force is generated through the gap between the valve stopper 83 and the seating surface.

  In the form shown in FIG. 2, the initial load of the check valve C <b> 2 provided on the piston 6 can be adjusted via an adjuster 10 b attached to the cap member 10. Further, the flow rate of the working fluid passing through the communication passages 60 and 61 of the piston 6 can be adjusted via an adjuster 10 c that is also attached to the cap member 10.

  The rod guide 7 that partitions the extension side action chamber P1 and the reservoir chamber R is formed with a flow path L1 that always communicates the extension side action chamber P1 and the reservoir chamber R.

  Specifically, as shown in FIG. 3, the rod guide 7 has a bush 70a that is formed in a small-diameter cylindrical shape and the outer periphery of the rod 5 is in sliding contact with, and a guide portion 70 that is formed in a nut shape on the outer periphery. A sheet portion 71 that extends in the radial direction from the lower end portion of the guide portion 70 in the drawing and carries the suspension spring S, and is coaxially connected to the guide portion 70 from the outer peripheral end portion of the seat portion 71 to the lower side in the drawing. It is provided with a coupling portion 72 provided and threaded on the outer periphery.

  By providing the above configuration, the rod guide 7 can be coupled to the cylinder 4 by screwing the coupling portion 72 to the inner periphery of the cylinder 4 and slidably support the rod 5 by the bush 70a. .

  Further, an annular spring seat 9 for preventing the rod guide 7 from being scraped by the suspension spring S is crowned on the outer peripheral portion on the upper surface side of the seat portion 71 in the drawing, and the rod guide 7 is attached to the spring seat 9. The suspension spring S is supported via

  The flow path L1 is formed such that the extension side working chamber P1 side opening (lower side in the figure) is formed on the inner side and the reservoir chamber R side opening (upper side in the figure) is formed on the outer side, and penetrates the sheet portion 71 obliquely. .

  By providing the flow path L1, when the expansion side working chamber P1 is depressurized when the fork main body contracts and the inside of the expansion side working chamber P1 becomes lower in pressure than the reservoir chamber R, the working fluid in the reservoir chamber R is expanded. It is possible to prevent the internal pressure of the extension side action chamber P1 from flowing into the side action chamber P1 and lower than the reservoir pressure.

  Therefore, the inside of the extension side working chamber P1 becomes lower than the reference pressure, and exerts a suction force on the piston 6 so that a desired compression side damping force cannot be obtained. There is no possibility that the piston 6 is pulled back to the expansion side working chamber P1 side and the riding comfort of the two-wheeled vehicle is deteriorated.

  Further, since the flow path L1 is formed obliquely on the rod guide 7 and is disposed obliquely with respect to the liquid level O, the expansion side working chamber P1 is pressurized when the fork body is extended, and the flow path L1 is removed from the flow path L1. The working fluid to be jetted first comes into contact with the suspension spring S and the inner periphery of the fork main body.

  That is, since the working fluid jetted from the flow path L1 does not directly contact the liquid level O, it is possible to prevent the working fluid jetted from the flow path L1 from entraining bubbles when the fork body is extended. Therefore, even if the working fluid in the reservoir chamber R flows into the cylinder 4 when the fork body contracts, it is possible to prevent the bubbles from entering the extension side working chamber P1 and obtain a desired damping force. Is possible.

  In addition, since the working fluid is not jetted in the vertical direction even when the front fork is assembled, it is possible to prevent the working fluid from being applied to an operator or the like and to improve the workability of the front fork assembling work. Become.

  The configuration of the flow path L1 is not limited to the above, and an appropriate configuration is selected as long as the working fluid jetted from the flow path L1 can be prevented from coming into direct contact with the liquid level O. Is possible.

  For example, the configuration shown in FIGS. 4A and 4B may be adopted. FIG. 4A shows a first modification in which the flow path L2 is provided horizontally with the liquid surface, and FIG. A second modified example in which a part of the reservoir chamber R side opening of the flow path L3 is closed with a spring seat 9 is shown.

  According to the first modified example, since the working fluid jetted from the flow path L2 first contacts the inner periphery of the fork main body, the working fluid is prevented from directly contacting the liquid level O, and the flow path is inclined. It is possible to achieve the same effect as provided (FIG. 3).

  According to the second modification, a part of the opening on the reservoir chamber R side in the flow path L3 is blocked by the inner peripheral portion of the spring seat 9, so that the flow path L3 is perpendicular to the liquid level O. Even if formed, the working fluid passing through the flow path L3 is partially blocked by the spring seat 9, and does not jet in the vertical direction. Accordingly, it is possible to prevent the working fluid from coming into direct contact with the liquid level O and to achieve the same effect as when the flow path is provided obliquely (FIG. 3).

  Although not shown, the flow path may be provided on the head portion side of the cylinder 4, and in this case, from the flow path as in the flow path L2 of the first modified example (FIG. 4A). The working fluid that is jetted first contacts the inner periphery of the fork main body.

  Furthermore, in the second modified example, the inner periphery of the spring seat 9 covers the part of the opening on the reservoir chamber R side of the flow path L3, but a wall plate (not shown) other than the spring seat 9 is used. The wall plate may be provided to block a part of the reservoir chamber R side opening in the flow path L3.

  The diameters of the flow paths L1, L2, and L3 can be selected as appropriate, but when the extension side action chamber P1 is pressurized, the working fluid flows out from the extension side action chamber P1 to the reservoir chamber R. Is set to produce a predetermined resistance. Therefore, the damping force on the extension side of the front fork is determined by the flow path L1 and the damping force generating means V1 provided in the piston 6 and the check valve C1 provided in the base member 8.

  Next, the operation of the front fork as a fluid pressure shock absorber in one embodiment will be described with reference to FIGS.

  In the front fork extension process in which the fork body extends, the extension side working chamber P1 is pressurized and the working fluid passes through the flow path L1, the damping force generation means V1 of the piston 6 and the check valve C1 of the base member 8, The front fork generates a damping force on the extension side. At this time, the working fluid that is deficient in the retraction chamber of the rod 5 flows from the reservoir chamber R into the pressure-side chamber P2 via the check valve C1 of the base member 8.

  On the other hand, in the front fork contraction process in which the fork main body contracts, the pressure side working chamber P2 is pressurized and the working fluid passes through the check valve C2 of the piston 6 and the damping force generation means V2 of the base member 8, so that the front fork Generates a damping force on the compression side. At this time, surplus working fluid in the immersion chamber of the rod 5 flows out into the reservoir chamber R via the damping force generating means P2 of the base member 8. Further, when the pressure in the extension side working chamber P1 decreases and becomes lower than the reservoir pressure, the working fluid in the reservoir chamber R flows into the extension side working chamber P1 through the flow path L1.

  While the preferred embodiment of the present invention has been described above, it should be understood that modifications, variations and changes may be made without departing from the scope of the claims.

  For example, in the above embodiment, the present invention is embodied in the front fork. However, the present invention is not limited to this. For example, the present invention may be embodied in another fluid pressure buffer such as a rear cushion unit.

  In the above embodiment, the front fork is set upside down. However, the inner tube may be set up on the vehicle body side and the outer tube may be set up on the axle side so as to be set upright.

  Further, the present invention may be embodied in a double rod type damper.

A Air chamber C1, C2 Check valve G Air chamber L1, L2, L3 Flow path P1 Stretch side working chamber P2 Pressure side working chamber R Reservoir chamber V1 Stretching side damping force generating means (laminated leaf valve)
V2 Pressure side damping force generation means (leaf valve)
DESCRIPTION OF SYMBOLS 1 Outer tube 2 Inner tube 3 Damper 4 Cylinder 5 Rod 6 Piston 7 Rod guide 8 Base member 9 Spring seat 10 Cap member 20 Bottom member 60, 61, 80, 81 Communication path

Claims (5)

A shock absorber body comprising an outer tube and an inner tube slidably inserted into the outer tube; a damper which is accommodated in the shock absorber body and generates a predetermined damping force; and the shock absorber body; A reservoir chamber formed between the damper and the damper,
In the reservoir chamber, working fluid is stored, and gas is accommodated upward through the liquid level,
The damper includes a cylinder that contains a working fluid, a rod that moves in the cylinder in the axial direction as the shock absorber body expands and contracts, and an extension-side working chamber and a pressure-side working chamber that are held by the rod in the cylinder. And a rod guide that is formed in an annular shape and that is slidably in contact with the outer periphery of the rod and mounted on the head of the cylinder to partition the extension side working chamber and the reservoir chamber. In the pressure buffer,
The rod guide is immersed in the working fluid in the reservoir chamber, and the damper includes a flow path that always communicates the extension side working chamber and the reservoir chamber;
The fluid pressure buffer, wherein the flow path is formed in a direction not orthogonal to the liquid level.   2. The fluid pressure shock absorber according to claim 1, wherein the flow path is formed on the head portion side of the cylinder or the rod guide horizontally with the liquid surface.   The fluid pressure buffer according to claim 1, wherein the flow path is formed in the rod guide obliquely with respect to the liquid level. A shock absorber body comprising an outer tube and an inner tube slidably inserted into the outer tube; a damper which is accommodated in the shock absorber body and generates a predetermined damping force; and the shock absorber body; A reservoir chamber formed between the damper and the damper,
In the reservoir chamber, working fluid is stored, and gas is accommodated upward through the liquid level,
The damper includes a cylinder that contains a working fluid, a rod that moves in the cylinder in the axial direction as the shock absorber body expands and contracts, and an extension-side working chamber and a pressure-side working chamber that are held by the rod in the cylinder. And a rod guide that is formed in an annular shape and that is slidably in contact with the outer periphery of the rod and mounted on the head of the cylinder to partition the extension side working chamber and the reservoir chamber. In the pressure buffer,
The rod guide is immersed in the working fluid in the reservoir chamber, and the damper includes a flow path that always communicates the extension side working chamber and the reservoir chamber;
The fluid pressure buffer, wherein the flow path is formed in the rod guide perpendicular to the liquid surface, and includes a wall plate that closes a part of the reservoir chamber side opening in the flow path. A suspension spring supported by the rod guide as well as energizing the shock absorber body in the extension direction so that the outer periphery extends along the inner periphery of the shock absorber body;
5. The fluid pressure shock absorber according to claim 4, wherein the wall plate is formed of a spring seat interposed between the rod guide and a suspension spring.

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