JP2005147210A - Vehicular hydraulic buffer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide hydraulic buffer with pistons whose valves are arranged in simplified construction for reducing the cost while disusing a pressure side base valve device for generating pressure side damping force on operating oil whose amount is equivalent to the volume of a piston rod moved therein. <P>SOLUTION: This vehicular hydraulic buffer 1 comprises the hydraulic buffers 100, 200 provided on the right and left sides of a wheel. The hydraulic buffer 100 on one side has an expansion-pressure common oil path 42 in the piston 32, a pressure side valve assembly 101B in an opening portion at the lower end of the oil path 42 movably in the axial direction for generating damping force substantially only during compression and an oil path 50 for volume compensation for the piston rod 15, which normally opens a piston rod side oil chamber 41A to an oil reservoir 43. The hydraulic buffer 200 on the other side has an expansion-pressure common oil path 42 in the piston 32, an expansion side assembly 201B in an opening portion at the upper end of the oil path 42 movably in the axial direction for generating damping force substantially only during expansion and an oil path 70 for volume compensation for the piton rod 15, which normally opens a piston side oil chamber 41B to the oil reservoir 43. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention attaches the lower ends of a pair of hydraulic shock absorbers disposed on the left and right of a wheel of a motorcycle or the like to a common axle or an axle side member attached to a common axle, and substantially on one side of the left and right. A hydraulic shock absorber that generates only the compression side damping force is provided, and a hydraulic shock absorber that generates substantially only the expansion side damping force is provided on the other side, and one hydraulic shock absorber is constituted by a pair of right and left hydraulic shock absorbers. The present invention relates to a unit-type hydraulic shock absorber.

  Patent Document 1 discloses a motorcycle having a compression leg 5 that essentially exhibits a damping function only during a compression movement and a return leg 6 that essentially exhibits a damping function only during a return (extension) movement. A front fork is disclosed.

  The front fork of Patent Document 1 has a pressure chamber unit 22 connected to the outer periphery of the lower portion of the inner tube 8 as shown in FIG. The pressure chamber unit 22 includes a gas (nitrogen gas) in the space 23 and a displaceable separation piston 24, and a control valve unit 25 (pressure-side base valve device) is provided between the space 17 and the pressure chamber unit 22. Is provided.

The control valve unit 25 (pressure side base valve device) includes an adjusting screw 26 for setting a bleed amount and a valve function body. The valve function body is mainly provided to generate a compression side damping force for the hydraulic oil corresponding to the volume of entry of the piston rod 10 into the damper cylinder 13.
JP2001-165221 ([0029], [0032])

  In the thing of patent document 1, since each leg is equipped with the control valve unit 25 (pressure side base valve apparatus) which generates the compression side damping force with respect to the hydraulic oil for the approach volume of a piston rod, the following problem There is a point.

  (1) Since the control valve unit 25 (pressure-side base valve device) is provided, the number of parts increases and the cost increases. As a result, it is difficult to apply to hydraulic shock absorbers such as small motorcycles with cost constraints.

  (2) Normally, the compression side damping force generated in the compression side base valve device is set larger than the compression side damping force generated in the piston portion at the tip of the piston rod. The reason is that when the piston rod moves from the compression stroke to the extension stroke, the piston rod side oil chamber is filled with sufficient hydraulic oil so that negative pressure is not generated in the piston rod side oil chamber.

  However, if the compression-side damping force generated at the compression-side base valve portion is to be made larger than the compression-side damping force generated at the piston portion, the piston rod cross-sectional area usually has an annular cross-sectional area (from the piston cross-sectional area to the piston rod Therefore, it is necessary to increase the pressure in the piston side oil chamber to increase the differential pressure.

  As a result, the internal pressure of the piston-side oil chamber becomes excessive. In particular, in a hydraulic shock absorber (for example, Japanese Utility Model Publication No. 59-149149) in which only the orifice hole is provided in the pressure-side base valve portion, the valve constituting the pressure-side base valve portion. The body 22 and the valve seat 23 may be destroyed.

  The compression side damping force at the piston part is the value obtained by multiplying the sectional area of the piston by subtracting the sectional area of the piston rod from the annular sectional area and the differential pressure of the oil chambers on both sides of the piston part. The generated compression side damping force is a value obtained by multiplying the cross-sectional area of the piston rod by the pressure difference between the chambers on both sides of the compression side base valve portion.

  (3) Next, in the compression leg 5, as shown in FIGS. 4 and 5 of Patent Document 1, the piston 12 fixed to the tip of the piston rod 10 has a very hard first shim stack 36 (compression side damping). Valve) and a very weak second shim stack 37 (a valve that opens when extended).

  Then, the damping force of the compression stroke is generated by the first shim stack 36 (pressure side damping valve), and the second shim stack 37 (check valve that opens when extended) that functions as a check valve easily opens during expansion. Thus, the damping force in the return (extension) stroke is not generated.

  In the return leg 6, as shown in FIGS. 6 and 7 of Patent Document 1, a weak fourth shim stack 37 '(a check valve that opens at the time of compression) and a hard member are fixed to the piston 12 fixed to the tip of the piston rod 10. A third shim stack 36 '(extension side damping valve) is provided.

  The damping force of the expansion stroke is generated by the third shim stack 36 ', and during compression, the fourth shim stack 37' functioning as a check valve is easily opened to substantially reduce the damping force of the compression stroke. It does not occur.

  In this way, the generation of the damping force in the compression stroke and the extension stroke is shared by the left and right legs, the compression-side damping valve is provided in the compression leg piston, the expansion-side damping valve is provided in the return leg piston, Or the generation mechanism of the extension side damping force is simplified.

  However, the compression leg piston still has a compression damping valve at the top opening, a check valve that opens upon extension at the bottom opening, and the return leg piston has an extension damping valve at the bottom opening, A check valve is provided at the top opening that opens during compression.

That is, conventionally, the compression side damping valves arranged on the upper end surfaces of the respective pistons of the left and right hydraulic shock absorbers are collected at the upper end portions of the pistons of the one side hydraulic shock absorbers. The expansion side damping valve arranged on the lower end surface of the piston is only collected on the lower end surface of the piston on the other side, and the compression side damping valve and check valve, or the extension side damping valve and check are placed in the upper and lower openings of each piston. The arrangement of the valves is not different from the conventional one, and the number of valves to be used is not substantially changed.
As a result, the cost associated with the valve portion does not change much.

  (4) In addition, each piston of the left and right hydraulic shock absorbers is provided with a compression side oil passage and an extension side oil passage. In one hydraulic shock absorber, the area of the compression side oil passage is the area of the extension side oil passage. In the other hydraulic shock absorber, the area of the extension side oil passage is restricted by the area of the compression side oil passage.

  Therefore, in the case of a small-diameter piston, it is difficult to ensure the required pressure side or extension side oil passage area.

  The object of the present invention is to eliminate the pressure-side base valve device that generates the compression-side damping force for the hydraulic oil equivalent to the entry volume of the piston rod, and further simplify the arrangement of the piston valve and reduce the cost. An object of the present invention is to provide a hydraulic shock absorber that can be reduced.

  According to the first aspect of the present invention, hydraulic shock absorbers are provided on the left and right sides of the wheel, substantially only the compression side damping force is generated in the one side hydraulic shock absorber, and only the extension side damping force is substantially generated in the other side hydraulic shock absorber. In the hydraulic shock absorber for a vehicle, the one-side hydraulic shock absorber has an outer cylinder attached to the wheel side and an inner cylinder provided in the outer cylinder, and slides in the inner cylinder. A piston rod that is attached to the vehicle body side, a piston rod side oil chamber and a piston side oil chamber that are partitioned by the piston are provided in the inner cylinder; An oil reservoir chamber and a gas chamber above the oil reservoir chamber are provided between the cylinder and the outer cylinder, and a common oil passage is provided in the piston of the hydraulic shock absorber on the one side, and the lower end of the oil passage By providing a pressure side valve or pressure side valve assembly in the axial direction so as to be movable in the axial direction, In addition, the piston rod side oil chamber is provided with an oil passage for volume compensation of the piston rod that is always open to the oil reservoir chamber, and the piston of the hydraulic shock absorber on the other side is provided. An oil passage common to pressure expansion is provided, and an extension side valve or extension side valve assembly is provided in the opening at the upper end of the oil passage so as to be movable in the axial direction. In addition, an oil passage for volume compensation of a piston rod that is always open to the oil reservoir chamber is provided in the piston-side oil chamber.

  According to a second aspect of the present invention, in the first aspect of the present invention, the pressure side valve assembly or the extension side valve assembly further includes an annular valve having an opening, and a disk provided adjacent to the piston side of the annular valve. It consists of a valve.

  According to a third aspect of the present invention, in addition to the first aspect of the present invention, the compression side valve or the expansion side valve is an annular valve provided with an orifice hole.

  (Claims 1 to 3) (a) “A common oil passage is provided in the piston of the hydraulic shock absorber on one side, and the pressure side valve or the pressure side valve assembly is disposed in the axial direction at the opening at the lower end of the oil passage. By providing it movably, a damping force is generated substantially only during compression, and an oil passage for volume compensation of the piston rod that always opens to the oil reservoir chamber is provided in the oil chamber on the piston rod side. In the hydraulic shock absorber on one side, the hydraulic oil in the piston-side oil chamber that shrinks during the compression stroke is equivalent to the piston's cross-sectional area (including the cross-sectional area of the piston rod). The oil flows through the assembly to the upper piston rod side oil chamber, and further passes through the oil passage (opening) for volume compensation of the piston rod that is always open to the oil reservoir chamber, and then flows to the oil reservoir chamber.

  Therefore, even if an oil passage for volume compensation is provided in the piston rod side oil chamber, there is no problem in the operation of the piston rod. In addition, the pressure side valve valve or pressure side valve assembly generates a pressure side damping force for the hydraulic oil corresponding to the piston rod entry volume, so the pressure side base valve device provided at the bottom of the inner cylinder may be eliminated. it can.

  (b) “A common oil passage is provided in the piston of the hydraulic shock absorber on the other side, and an extension side valve or extension side valve assembly is provided in the opening at the upper end of the oil passage so as to be movable in the axial direction. Thus, a damping force is generated substantially only when extended, and an oil passage for volume compensation of the piston rod that always opens in the oil reservoir chamber is provided in the piston-side oil chamber. " Since no or substantially no compression side damping force is generated, the compression side base valve device can be eliminated.

  (c) “An oil passage common to the pressure extension is provided in the piston of the hydraulic shock absorber on one side, and the pressure side valve or the pressure side valve assembly is provided in the opening at the lower end of the oil passage so as to be movable in the axial direction. An oil passage common to the pressure extension was provided in the piston of the hydraulic shock absorber, and the extension side valve or the extension side valve assembly was provided in the opening at the upper end of the oil passage so as to be movable in the axial direction. The compression side piston has a pressure side valve or pressure side valve assembly only at its lower end, and the other side (extension side) piston has an extension side valve or extension side valve assembly only at its upper end. Therefore, the arrangement of the valves can be simplified as a whole, and the number of valves can be reduced. Therefore, the cost can be reduced.

  (d) Since the piston is provided only with an oil passage common to the pressure extension, as in Patent Document 1, the area of the oil passage is limited compared to the case where the piston is provided with the pressure side oil passage and the extension side oil passage. The required area of the oil passage can be secured even in the case of a small-diameter piston, and the degree of freedom in design can be improved. it can.

  1 is an overall view showing a hydraulic shock absorber for a vehicle according to a first embodiment, FIG. 2 is a cross-sectional view showing one of the left and right hydraulic shock absorbers, FIG. 3 is an enlarged view of a main part of FIG. FIG. 5A is an overall cross-sectional view, FIG. 5B is an enlarged view of a main part, FIG. 5 shows components of a compression side piston / valve assembly, FIG. 5A is a plan view showing an annular valve, and FIG. Is a sectional view showing a disk valve, FIG. 6C is a plan view showing a modification of the annular valve, FIG. 6 shows an operating state of the compression side piston / valve assembly, FIG. 6A is a sectional view showing a compressed state, and FIG. ) Is a cross-sectional view showing an extended state, FIG. 7 is a cross-sectional view showing the other hydraulic shock absorber, FIG. 8 is an enlarged view of the main part of FIG. 7, and FIG. 9 is an extension side piston / valve assembly. Is an overall cross-sectional view, (B) is an enlarged view of the main part, FIG. 10 shows the operating state of the expansion side piston / valve assembly, (A) FIG. 11 is a sectional view showing a tension state, FIG. 11 is a sectional view showing a compressed state, FIG. 11 is an overall view showing a hydraulic shock absorber for a vehicle according to a second embodiment, and FIG. 13 is an enlarged view of a main part of FIG. 12, FIG. 14 is a compression side piston / valve assembly, (A) is an overall sectional view, (B) is an enlarged view of the main part, FIG. 15 is a piston, and (A) is Sectional view, (B) is a plan view, FIG. 16 is a plan view showing a disk valve, FIG. 17 shows an annular valve, (A) is a sectional view, (B) is a plan view, and FIG. FIG. 19 is an enlarged view of a main part of FIG. 18, FIG. 20 is an enlarged side piston / valve assembly, (A) is an overall cross-sectional view, and (B) is an enlarged view of the main part.

Example 1 (FIGS. 1 to 10)
As shown in FIG. 1, a vehicle hydraulic shock absorber 1 includes left and right hydraulic shock absorbers 100 and 200 provided on both left and right sides of the vehicle. This hydraulic shock absorber 1 is a rear damper for a two-wheeled vehicle or the like, in which wheel side tubes of left and right hydraulic shock absorbers are attached to both sides of a common axle, or a rear wheel-side hydraulic shock absorber for a two-wheeled vehicle or the like. Thus, the left and right hydraulic shock absorbers are configured to be attached to a common swing arm, and exclude the independent suspension type hydraulic shock absorber.

  One of the left and right hydraulic shock absorbers 100 is configured as shown in FIGS. 2 to 6, and the other left and right hydraulic shock absorbers 200 are configured as shown in FIGS. 7 to 10. The hydraulic shock absorber 1 includes a piston / valve assembly 101A (hereinafter referred to as “pressure side”) that is provided at the tip of a piston rod 15 inserted into the inner cylinder 12 of one hydraulic shock absorber 100 and generates substantially only a compression side damping force. A piston / valve assembly ”) and a piston / valve assembly which is provided at the tip of the piston rod 15 inserted into the inner cylinder 12 of the other hydraulic shock absorber 200 and generates substantially only the extension side damping force. A solid body 201A (hereinafter referred to as “extension side piston / valve assembly”) is provided, and the generation of the compression side damping force and the extension side damping force is shared by the left and right hydraulic shock absorbers 100 and 200, respectively.

(Hydraulic shock absorber 100) (FIGS. 2 to 6)
As shown in FIG. 2, the hydraulic shock absorber 100 has an inner cylinder 12 standing on the bottom 11 </ b> A of the outer cylinder 11, and a piston rod 15 slidably supported on a rod guide 14 provided in an opening of the inner cylinder 12. The piston rod 15 is inserted into the inner cylinder 12. The wheel side mounting portion 13 is fixed to the bottom portion 11A. Further, the hydraulic shock absorber 100 is provided with a shaft sealing means 16 such as an oil seal at the opening of the outer cylinder 11, the piston rod 15 is sealed by the shaft sealing means 16, the piston rod 15 projects from the outer cylinder 11, and the piston A vehicle body side mounting portion 17 is provided at the protruding end of the rod 15.

  The hydraulic shock absorber 100 has a spring bearing support member 18A fixed to the outer periphery of the outer cylinder 11, a spring bearing 18B having a cam surface supported on the back by the spring bearing support member 18A, and a vehicle body side mounting provided on the piston rod 15. A suspension spring 20 is interposed between spring receivers 19 formed in the portion 17. The initial set load of the suspension spring 20 can be adjusted by the rotation of the spring support 18B relative to the spring support member 18A. The hydraulic shock absorber 100 buffers the impact force received from the road surface when the vehicle travels by the spring reaction force of the suspension spring 20.

  The hydraulic shock absorber 100 has the above-described compression side piston / valve assembly 101 </ b> A in order to suppress the expansion and contraction vibration of the suspension spring 20.

  The compression side piston / valve assembly 101A has a stopper collar 31, a piston 32, a washer 33, a disk valve 34, an annular valve 35, a valve spring 36, and a valve stopper 37 inserted in this order into the small diameter portion of the piston rod 15. It is held by the caulking portion 38. The annular valve 35 and the disc valve 34 constitute a pressure side valve assembly 101B.

  The piston 32 includes a piston ring that slidably contacts the inner circumference of the inner cylinder 12, and the piston rod side oil chamber 41 </ b> A on the side where the piston rod 15 is inserted and the piston rod 15 are inserted inside the inner cylinder 12. It has a pressure expansion common oil passage 42 that is divided into a piston-side oil chamber 41B on the non-piston side and communicates the piston rod-side oil chamber 41A and the piston-side oil chamber 41B. The disc valve 34 and the annular valve 35 are slid on the inner periphery of the guide 37A of the valve stopper 37, and are provided so as to be movable in the axial direction with respect to the opening at the lower end of the pressure expansion common oil passage 42. A damping force is generated only at times.

  The annular valve 35 (FIG. 5A) has a plurality of hole-shaped openings 35A, slides the inner periphery of the guide 37A of the valve stopper 37, and is more than the pressure increase common oil passage 42 on the lower end surface of the piston 32. The oil passage 42 is opened and closed by contacting and separating from the valve seat 32A formed on the outer peripheral side. The valve spring 36 biases the annular valve 35 toward the valve seat 32A. The disc valve 34 (FIG. 5B) is adjacent to the piston 32 side of the annular valve 35 around the guide 37 </ b> A of the valve stopper 37, and between the lower end surface of the piston 32 and the washer 33 and the annular valve 35. The outer periphery is sandwiched between the valve seat 32A of the piston 32 and closer to the common pressure oil passage 42 than the valve seat 32A, and the outer periphery is bent so as to be in contact with and separated from the annular valve 35 with the inner periphery being cantilevered. It deform | transforms and opens and closes the hole-shaped opening part 35A of the annular valve 35.

  Therefore, in the compression side piston / valve assembly 101A, during compression, the hydraulic pressure of the piston side oil chamber 41B is applied to the disc valve 34 from the hole-shaped opening 35A of the annular valve 35, as shown in FIG. By causing the disk valve 34 to bend and deform (in other words, to generate a pressure-side damping force), the oil in the piston-side oil chamber 41B flows into the piston rod-side oil chamber 41A via the pressure-extended common oil passage 42. 6B, the oil pressure in the piston rod side oil chamber 41A is applied to the disc valve 34 and the annular valve 35, and the disc valve 34 and the annular valve 35 are resisted against the urging force of the valve spring 36. Then, the oil in the piston rod side oil chamber 41A is caused to flow to the piston side oil chamber 41B via the oil passage 42 through a path that bypasses the disk valve 34, which is a valve means for generating a compression side damping force.

  The piston 32 includes two small-diameter hole orifices 32B that connect the pressure-extended common oil passage 42 to the piston-side oil chamber 41B on the circumference of the valve seat 32A.

  The hydraulic shock absorber 100 is provided with a lower oil reservoir chamber 43 and an upper gas chamber 44 in an annular space between the outer cylinder 11 and the inner cylinder 12, and the piston rod side oil chamber 41 </ b> A is always open to the oil reservoir chamber 43. The oil passage 50 for volume compensation of the piston rod 15 is provided in the inner cylinder 12.

  The oil passage 50 is provided below the oil level (L) of the oil reservoir 43, and the position of the piston 32 (FIGS. 2 and 3) when fully extended is positioned below the opening of the oil passage 50, The oil passage 50 is always opened to the piston rod side oil chamber 41 </ b> A and the oil reservoir chamber 43. In other words, the hydraulic shock absorber 100 is provided with the extended position regulating member 60 of the piston rod 15 between the inner cylinder 12 side and the piston rod 15 side, whereby the oil passage 50 is connected to the piston rod side oil chamber 41A and the piston rod side oil chamber 41A. The oil reservoir 43 is always opened. The extended position restricting member 60 includes a collar 61 fixed to the upper inner periphery of the inner cylinder 12 (a stopper ring 62 in which the outer periphery of the collar 61 is engaged with the inner periphery of the inner cylinder 12, and the rod guide 14. Sandwiched between). A rebound spring (coil spring) 63 is provided between the tip end of the collar 61 and the stopper collar 31 held by the piston rod 15 to provide a buffer at the time of maximum extension. regulate.

Accordingly, the hydraulic shock absorber 100 operates as follows.
(Compression process)
During compression of the hydraulic shock absorber 100, the outer cylinder 11, the inner cylinder 12 and the piston rod 15 are relatively compressed, and the suspension spring 20 is compressed. Further, the piston rod 15 enters the inner cylinder 12, and the oil in the piston side oil chamber 41B flows into the piston rod side oil chamber 41A through the orifice 32B of the piston 32 at a low speed, and is compressed by the throttle resistance of the orifice 32B during this time. Get damping force. Further, at medium and high speeds, the oil in the piston-side oil chamber 41B deflects and deforms the disk valve 34 in the pressure expansion common oil passage 42 of the piston 32 and flows into the piston rod-side oil chamber 41A. Get compression side damping force. The spring force of the suspension spring 20 buffers an impact during compression, and the compression side damping force controls the compression speed of the suspension spring 20.

  When the hydraulic shock absorber 100 is compressed, oil corresponding to the volume of the piston rod 15 entering the inner cylinder 12 is discharged from the piston rod side oil chamber 41 </ b> A through the oil passage 50 of the inner cylinder 12 to the oil reservoir chamber 43.

(Extension process)
When the hydraulic shock absorber 100 is extended, the outer cylinder 11, the inner cylinder 12 and the piston rod 15 are relatively extended, and the suspension spring 20 is extended. Further, the piston rod 15 retreats from the inner cylinder 12, and the oil in the piston rod side oil chamber 41A moves the disk valve 34 and the annular valve 35 of the pressure increase common oil passage 42 of the piston 32 downward to move the piston side oil chamber. It flows to 41B.

  When the hydraulic shock absorber 100 is fully extended, the rebound spring 63 backed up and supported by the collar 61 fixed to the inner cylinder 12 is compressed by the stopper collar 31 of the piston 32 to restrict the maximum extension stroke.

  When the hydraulic shock absorber 100 is extended, the oil corresponding to the withdrawal volume of the piston rod 15 from the inner cylinder 12 is replenished from the oil reservoir chamber 43 through the oil passage 50 of the inner cylinder 12 to the piston rod side oil chamber 41A. The piston 32 passes through the pressure common oil passage 42 of the piston 32 and is replenished to the piston-side oil chamber 41B.

(Hydraulic shock absorber 200) (FIGS. 7 to 10)
The only difference between the hydraulic shock absorber 200 and the hydraulic shock absorber 100 is that the compression side piston / valve assembly 101A in the hydraulic shock absorber 100 is replaced with an expansion side piston / valve assembly 201A, as shown in FIGS. .

  That is, the hydraulic shock absorber 200 has the above-described extension-side piston / valve assembly 201 </ b> A in order to suppress the expansion and contraction vibration of the suspension spring 20.

  As shown in FIGS. 7 to 9, the extension side piston / valve assembly 201A provided at the tip of the piston rod 15 inserted into the inner cylinder 12 is the same as the aforementioned pressure side piston / valve assembly 101A. Was installed in reverse.

  The extension-side piston / valve assembly 201A has a valve stopper 37, a valve spring 36, an annular valve 35, and a disc valve 34 that are the same as the components of the compression-side piston / valve assembly 101A at the small diameter portion of the piston rod 15. The washer 33 and the piston 32 are inserted in this order, and are held by the caulking portion 38.

  The piston 32 includes a piston ring that slidably contacts the inner circumference of the inner cylinder 12, and the piston rod side oil chamber 41 </ b> A on the side where the piston rod 15 is inserted and the piston rod 15 are inserted inside the inner cylinder 12. It has a pressure expansion common oil passage 42 that is divided into a piston-side oil chamber 41B on the non-piston side and communicates the piston rod-side oil chamber 41A and the piston-side oil chamber 41B. The washer 33, the disk valve 34, and the annular valve 35 are slid on the inner periphery of the guide 37A of the valve stopper 37, and are provided so as to be axially movable with respect to the opening at the upper end of the pressure increasing common oil passage 42. Therefore, the damping force is generated only when it is extended.

  The annular valve 35 (FIG. 5A) includes a plurality of hole-shaped openings 35A, and slides the inner periphery of the guide 37A of the valve stopper 37 so that it is more than the pressure increasing common oil passage 42 on the upper end surface of the piston 32. The oil passage 42 is opened and closed by contacting and separating from the valve seat 32A formed on the outer peripheral side. The valve spring 36 biases the annular valve 35 toward the valve seat 32A. The disc valve 34 (FIG. 5B) is adjacent to the piston 32 side of the annular valve 35 around the guide 37A of the valve stopper 37, and between the upper end surface of the piston 32 and the washer 33 and the annular valve 35. The outer periphery is sandwiched between the valve seat 32A of the piston 32 and closer to the common pressure oil passage 42 than the valve seat 32A, and the outer periphery is bent so as to be in contact with and separated from the annular valve 35 with the inner periphery being cantilevered. It deform | transforms and opens and closes the hole-shaped opening part 35A of the annular valve 35.

The annular valve 35 and the disc valve 34 constitute an extension side valve assembly 201B.
Accordingly, in the extension side piston / valve assembly 201A, when extended, the hydraulic pressure of the piston rod side oil chamber 41A is transferred from the hole-shaped opening 35A of the annular valve 35 to the disc valve 34 as shown in FIG. In addition, the disk valve 34 is flexibly deformed (in other words, an expansion-side damping force is generated), so that the oil in the piston rod-side oil chamber 41A flows into the piston-side oil chamber 41B via the pressure-extended common oil passage 42. During compression, as shown in FIG. 10B, the oil pressure in the piston side oil chamber 41B is applied to the disc valve 34 and the annular valve 35, and the disc valve 34 and the annular valve 35 are resisted against the urging force of the valve spring 36. The oil in the piston-side oil chamber 41B is caused to flow through the oil passage 42 to the piston rod-side oil chamber 41A through a path that bypasses the disk valve 34 that is the valve means for generating the extension-side damping force.

  The piston 32 includes two small-diameter hole orifices 32B on the circumference of the valve seat 32A for communicating the pressure increase common oil passage 42 to the piston rod side oil chamber 41A.

  The hydraulic shock absorber 200 is provided with a lower oil reservoir chamber 43 and an upper gas chamber 44 in an annular space between the outer cylinder 11 and the inner cylinder 12, and the piston-side oil chamber 41B is always open to the oil reservoir chamber 43. An oil passage 70 for volume compensation of the piston rod 15 is provided in the inner cylinder 12. Since this oil passage 70 does not generate a damping force during compression, it is only necessary to consider replenishment of hydraulic oil during expansion. Therefore, a sufficiently large opening can be set.

Accordingly, the hydraulic shock absorber 200 operates as follows.
(Compression process)
During compression of the hydraulic shock absorber 200, the outer cylinder 11, the inner cylinder 12, and the piston rod 15 are relatively compressed, and the suspension spring 20 is compressed. Further, the piston rod 15 enters the inner cylinder 12, and the oil in the piston side oil chamber 41B moves the disk valve 34 and the annular valve 35 of the pressure increase common oil passage 42 of the piston 32 upward to move the piston rod side oil chamber. It flows to 41A.

  When the hydraulic shock absorber 200 is compressed, the oil corresponding to the volume of the piston rod 15 entering the inner cylinder 12 is discharged from the piston-side oil chamber 41 </ b> B through the oil passage 70 of the inner cylinder 12 to the oil reservoir chamber 43.

(Extension process)
When the hydraulic shock absorber 200 is extended, the outer cylinder 11, the inner cylinder 12 and the piston rod 15 are relatively extended, and the suspension spring 20 is extended. Further, the piston rod 15 retreats from the inner cylinder 12, and the oil in the piston rod side oil chamber 41A flows into the piston side oil chamber 41B through the orifice 32B of the piston 32 at a low speed, and is extended by the restriction resistance of the orifice 32B during this time. Get side damping force. Further, at medium and high speeds, the oil in the piston rod side oil chamber 41A deflects and deforms the disk valve 34 of the pressure expansion common oil passage 42 of the piston 32 and flows into the piston side oil chamber 41B. Get extension side damping force. The extension side damping force prevents the suspension spring 20 from resonating.

  When the hydraulic shock absorber 200 is fully extended, the rebound spring 71 backed up by the rod guide 14 on the inner cylinder 12 side is compressed by the valve stopper 37 of the piston 32 to restrict the maximum extension stroke.

  When the hydraulic shock absorber 200 is extended, oil corresponding to the withdrawal volume of the piston rod 15 from the inner cylinder 12 is supplied from the oil reservoir 43 through the oil passage 70 of the inner cylinder 12 to the piston-side oil chamber 41B.

  Therefore, in the hydraulic shock absorber 1, the compression side piston / valve assembly 101A of the hydraulic shock absorber 100 generates a compression side damping force during the compression stroke, and the expansion side piston / valve assembly 201A of the hydraulic shock absorber 200 during the expansion stroke. The expansion and contraction vibration of the suspension spring 20 is suppressed by the extension side damping force generated.

  In the compression side piston / valve assembly 101A (the same applies to the expansion side piston / valve assembly 201A), the set of the disk valve 34 and the annular valve 35 is placed on the annular valve 300 shown in FIG. It can be replaced. The annular valve 300 has a hole orifice 301. The annular valve 300 has the same inner and outer diameters as the annular valve 35, is urged toward the valve seat 32 </ b> A of the piston 32 by the valve spring 36, and can slide the guide 37 </ b> A of the valve stopper 37. It is provided so that it can move in the axial direction with respect to the opening. In the compression side valve assembly 101B, the oil in the piston side oil chamber 41B at the time of compression is passed through the orifice 301 and flows from the oil passage 42 of the piston 32 to the piston rod side oil chamber 41A, and the compression side damping force based on the restriction resistance of the orifice 301 is applied. The annular valve 300 is moved downward by the hydraulic pressure of the piston rod side oil chamber 41A during expansion and flows to the piston side oil chamber 41B. In the extension side piston / valve assembly 201A, the oil in the piston rod side oil chamber 41A at the time of extension passes through the orifice 301, and flows from the oil passage 42 of the piston to the piston side oil chamber 41B. A damping force is generated, and the annular valve 300 is moved upward by the hydraulic pressure of the piston-side oil chamber 14B during compression to flow into the piston rod-side oil chamber 41A.

According to the present embodiment, the following operational effects can be obtained.
(a) “A common oil pressure passage 42 is provided in the piston 32 of the hydraulic shock absorber 100 on one side, and an annular valve (pressure side valve) 300 or an annular valve 35 is provided at the lower end of the oil passage 42. By providing the pressure side valve assembly 101B composed of the disk valve 34 so as to be movable in the axial direction, a damping force is substantially generated only during compression, and the piston rod side oil chamber 41A is always opened to the oil reservoir chamber 43. From the hydraulic shock absorber 100 on one side, the hydraulic oil in the piston-side oil chamber 41B that shrinks during the compression stroke has the cross-sectional area of the piston rod 15 reduced. The hydraulic oil corresponding to the cross-sectional area of the piston 32 (including the cross-sectional area of the piston rod 15) is included in the pressure-side damping force generating means (the annular valve 300 or the pressure-side valve assembly 1) of the piston 32. 1B) flows as the top of the piston rod side oil chamber 41A and further through the oil passage 50 for volume compensation of the piston rod 15 to constantly open to the oil reservoir chamber 43 (opening), flows into the oil reservoir chamber 43.

  Therefore, even if the oil passage 50 for volume compensation is provided in the piston rod side oil chamber 41A, there is no problem in the operation of the piston rod 15. Further, since the compression side damping force generating means (the annular valve 300 or the pressure side valve assembly 101B) of the piston 32 generates a compression side damping force for the hydraulic oil corresponding to the entry volume of the piston rod 15, the inner cylinder The pressure side base valve device provided at the bottom of 12 can be eliminated.

  (b) “An oil passage 42 common to the pressure extension is provided in the piston 32 of the hydraulic shock absorber 200 on the other side, and an annular valve (extension side valve) 300 or an annular valve 35 is provided at the upper end of the oil passage 42. By providing the expansion side valve assembly 201B composed of the disk valve 34 so as to be movable in the axial direction, a damping force is generated substantially only when extended, and the piston side oil chamber 41B and the oil reservoir chamber 43 are always open. Therefore, since the hydraulic shock absorber 200 on the other side does not generate a pressure side damping force at all or substantially, the pressure side base valve device is abolished. can do.

  (c) “A common oil passage 42 is provided in the piston 32 of the hydraulic shock absorber 100 on one side, and the pressure side valve assembly 101B is provided in the opening at the lower end of the oil passage 42 so as to be movable in the axial direction. From the piston 32 of the hydraulic shock absorber 200 on the other side, a common oil passage 42 is provided, and the extension side valve assembly 201B is provided in the opening at the upper end of the oil passage 42 so as to be movable in the axial direction. The one side (compression side) piston 32 is provided with a compression side valve assembly 101B only at its lower end, and the other side (extension side) piston 32 is provided only at its upper end with an extension side valve assembly 201B. Therefore, the arrangement of the valves can be simplified as a whole, and the number of valves can be reduced. Therefore, the cost can be reduced.

  (d) Since the piston 32 is provided with only the oil passage 42 common to the pressure extension, as in Patent Document 1, the area of the oil passage is larger than when the piston is provided with the pressure side oil passage and the extension side oil passage. The area of the hole-shaped opening 35A of the annular valve 35 is not restricted, and the area of the oil passage 42 necessary for the small-diameter piston 32 can be secured even if the piston 32 has a small diameter. The degree of freedom can be improved.

Example 2 (FIGS. 11 to 20)
As shown in FIG. 11, the vehicle hydraulic shock absorber 1 includes left and right hydraulic shock absorbers 100 and 200 provided on the left and right sides of the vehicle. This hydraulic shock absorber 1 has a wheel-side tube of left and right hydraulic shock absorbers attached to both sides of a common axle, such as a front fork of a two-wheel vehicle or the like, or a rear wheel side hydraulic shock absorber such as a two-wheel vehicle. As described above, the left and right hydraulic shock absorbers are attached to a common swing arm, and are independent of the independent suspension type hydraulic shock absorber.

  One of the left and right hydraulic shock absorbers 100 is configured as shown in FIGS. 12 to 14, and the other left and right hydraulic shock absorbers 200 are configured as shown in FIGS. 18 and 20. The hydraulic shock absorber 1 is a pressure side piston that is provided at the tip of a piston rod 124 (piston bolt 124A) inserted into a damper cylinder (inner cylinder) 121 of one hydraulic shock absorber 100 and generates substantially only a compression side damping force.・ Valve assembly 101A is provided to generate substantially only the extension side damping force provided at the tip of the piston rod 124 (piston bolt 124A) inserted into the damper cylinder (inner cylinder) 121 of the other hydraulic shock absorber 200. The expansion side piston / valve assembly 201A is provided, and the generation of the compression side damping force and the extension side damping force is shared by the left and right hydraulic shock absorbers 100 and 200, respectively.

(Hydraulic shock absorber 100) (FIGS. 12 to 17)
As shown in FIG. 12, the hydraulic shock absorber 100 is configured by fitting a vehicle body side tube 111 and a wheel side tube 112 (outer cylinder) in a liquid-tight slidable manner. A bush 113 is provided on the inner periphery of the lower end of the vehicle body side tube 111, and a bush 114 is provided on the inner periphery of the upper end side of the vehicle body side tube 111. The wheel-side tube 112 is provided with an oil hole 112 </ b> A that connects an oil reservoir chamber 128 to be described later to an annular gap sandwiched between the bushes 113 and 114 between the vehicle body-side tube 111 and the wheel-side tube 112.

  The vehicle body side tube 111 is provided with a cap 116 detachably and liquid-tightly at the opening 115 at the upper end, and the vehicle body side tube 111 is provided with a vehicle body side mounting portion. The wheel side tube 112 is integrally provided with a bottom bracket 118 at a lower end portion, and a wheel side mounting portion 119 is provided at the bottom bracket 118.

  The hydraulic shock absorber 100 accommodates a damper cylinder 121 (inner cylinder) and a piston rod 124 that constitute a damper 120 inside a vehicle body side tube 111 and a wheel side tube 112. That is, the hydraulic shock absorber 100 has a damper cylinder 121 fixed inside the bottom bracket 118 standing inside the wheel side tube 112. A center bolt 122 inserted into the bottom of the bottom bracket 118 attracts the stopper ring 122A engaged with the inner periphery of the lower end of the damper cylinder 121, and the damper cylinder 121 is fixed to the bottom of the bottom bracket 118 with the bottom collar 122B interposed. .

  The front fork 110 is integrally fixed by screwing a sleeve 123 to the center portion of the cap 116, and a hollow piston rod 124 and a lock nut 123A are screwed to the lower end portion of the sleeve 123 inserted into the vehicle body side tube 111. The piston rod 124 is fixedly supported with respect to the vehicle body side tube 111. The piston rod 124 is slidably passed through a rod guide 125 provided at the upper end portion of the damper cylinder 121 and is inserted into the oil chamber 127 inside the damper cylinder 121. The piston rod 124 is attached to a piston bolt 124A provided at the insertion tip portion thereof. 126. The piston 126 is fixed by a nut 124B screwed to the piston bolt 124A. The piston 126 slides up and down on the inner surface of the damper cylinder 121. The oil chamber 127 is divided by the piston 126 into a piston rod side oil chamber 127A on the side where the piston rod 124 is inserted and a piston side oil chamber 127B on the side where the piston rod 124 is not inserted.

  In the hydraulic shock absorber 100, the space around the damper cylinder 121 between the vehicle body side tube 111 and the wheel side tube 112 is an oil reservoir chamber 128, and the upper portion of the oil reservoir chamber 128 is a gas chamber (air chamber) 129.

  The hydraulic shock absorber 100 is supported by a pin 130 </ b> A that a spring load adjuster 130 inserted into an annular space between the cap 116 and the sleeve 123 is screwed to the outer periphery of the sleeve 123 and abuts against the lower end surface of the spring load adjuster 130. A spring collar 131 composed of a combination of a plurality of members that move up and down, and between an upper spring seat 132 backed up by the spring collar 131 and a lower spring seat 133 fixed to the rod guide 125 at the upper end of the damper cylinder 121 A suspension spring 134 is interposed.

  The hydraulic shock absorber 100 buffers the impact force received from the road surface when the vehicle travels by the spring reaction force of the suspension spring 134 and the spring reaction force of the air spring of the air chamber 129.

  The hydraulic shock absorber 100 includes the above-described compression-side piston / valve assembly 101A in order to control the suspension spring 134 and the expansion / contraction vibration of the air spring of the air chamber 129.

  The pressure side piston / valve assembly 101A includes a valve stopper 140A, a piston 126 (FIG. 15), a valve collar 140B, a disc valve (pressure side valve) 141 (FIG. 16), and an annular valve 142 (FIG. 17) at the small diameter portion of the piston bolt 124A. ), The valve spring 143, the valve guide 144, and the valve stopper 140C are inserted in this order, and these are held by the nut 124B.

  The piston 126 includes a piston ring that slidably contacts the inner periphery of the damper cylinder 121, and the interior of the damper cylinder 121 is partitioned into the piston rod side oil chamber 127A and the piston side oil chamber 127B as described above, and is shown in FIG. As described above, the pressure increasing common oil passage 145 that connects the piston rod side oil chamber 127A and the piston side oil chamber 127B is provided. The disc valve 141 and the annular valve 142 are provided so as to move in the axial direction on the outer periphery of the valve collar 140B, and to be movable in the axial direction with respect to the opening at the lower end of the pressure expansion common oil passage 145. Is generated.

  The valve spring 143 is supported on the back by a valve guide 144 and presses the annular valve 142 and the disk valve 141 against the valve seat 126A formed on the outer peripheral side of the oil passage 145 on the lower end surface of the piston 126 by its urging force. The disc valve 141 is bent and deformed so that the inner peripheral side thereof contacts and separates from the annular valve 142 while the outer periphery is cantilevered between the valve seat 126A of the piston 126 and the annular valve 142. Open and close the hole-shaped opening 142A. The annular valve 142 has a plurality of hole-like openings 142 </ b> A that are opened and closed by the disk valve 141.

  The annular valve 142 and the disk valve 141 constitute a pressure side valve assembly 101B.

  Therefore, in the compression side piston / valve assembly 101A, during compression, the oil pressure of the piston side oil chamber 127B is applied to the disc valve 141 from the opening 142A of the annular valve 142, and the inner peripheral portion of the disc valve 141 is bent and deformed. (In other words, by generating a compression side damping force), the oil in the piston side oil chamber 127B is caused to flow to the piston rod side oil chamber 127A via the oil passage 145 of the piston 126. Further, at the time of extension, the oil pressure of the piston rod side oil chamber 127A is applied to the disk valve 141 and the annular valve 142, and the disk valve 141 and the annular valve 142 are moved downward against the urging force of the valve spring 143, and the piston rod side The oil in the oil chamber 127A is caused to flow through the oil passage 145 of the piston 126 to the piston-side oil chamber 127B through a path that bypasses the disk valve 141 that is a valve means for generating a compression-side damping force.

  Further, the pressure side piston / valve assembly 101A bypasses the piston 126 and allows the piston rod side oil chamber 127A and the piston side oil chamber 127B to communicate with each other inside the piston rod 124 (piston bolt 124A). The bypass channel 146 can be opened and closed by the needle valve 147A. At this time, the damping force adjuster 147 is screwed into the center of the sleeve 123 provided in the cap 116, the rod 147B supported by the damping force adjuster 147 is inserted into the hollow portion of the piston rod 124, and the above-mentioned needle is inserted into the insertion end. A valve 147A is provided.

  The needle valve 147A provided in the pressure side piston / valve assembly 101A of the hydraulic shock absorber 100 functions as a pressure side damping force adjusting device.

  One hydraulic shock absorber 100 is provided with a hole-compensating oil passage 150 for volume compensation of the piston rod 124, which always connects the piston rod-side oil chamber 127 </ b> A and the oil reservoir chamber 128 on the side wall on the upper end side of the damper cylinder 121. ing.

Accordingly, the hydraulic shock absorber 100 operates as follows.
(Compression process)
When the hydraulic shock absorber 100 is compressed, the vehicle body side tube 111 and the wheel side tube 112 are relatively compressed, and the suspension spring 134 is compressed. Also, the piston rod 124 enters the damper cylinder 121, and the oil in the piston-side oil chamber 127B flows into the piston rod-side oil chamber 127A through the bypass oil passage 146 of the piston 126 at a low speed, and the throttle of the needle valve 147A during this period The compression side damping force is obtained by resistance. Further, at medium and high speeds, the oil in the piston-side oil chamber 127B flows into the piston rod-side oil chamber 127A through the disk valve 141 of the pressure increase common oil passage 145 of the piston 126, and the pressure-side damping is caused by the deflection resistance of the disk valve 141 during this time. Gain power. The spring force of the suspension spring 134 buffers an impact during compression, and the compression side damping force controls the compression speed of the suspension spring 134.

  When the hydraulic shock absorber 100 is compressed, the oil corresponding to the volume of the piston rod 124 entering the damper cylinder 121 is discharged from the piston rod side oil chamber 127 </ b> A through the oil passage 150 of the damper cylinder 121 to the oil reservoir chamber 128.

(Extension process)
When the hydraulic shock absorber 100 is extended, the vehicle body side tube 111 and the wheel side tube 112 are relatively extended, and the suspension spring 134 is extended. In addition, the piston rod 124 retreats from the damper cylinder 121, and the oil in the piston rod side oil chamber 127A moves the disk valve 141 and the annular valve 142 of the pressure increase common oil passage 145 of the piston 126 downward to move the piston side oil. Flows into chamber 127B.

  When the hydraulic shock absorber 100 is fully extended, the rebound spring 139 backed up and supported by a spring receiver 138 locked to the inner peripheral portion of the upper end side of the damper cylinder 121 is compressed by the upper end flange of the piston bolt 124A to restrict the maximum extension stroke. To do.

  When the hydraulic shock absorber 100 is extended, oil corresponding to the retraction volume of the piston rod 124 from the damper cylinder 121 is replenished from the oil reservoir chamber 128 through the oil passage 150 of the damper cylinder 121 to the piston rod side oil chamber 127A. Through the oil passage 145 of the piston 126, the piston side oil chamber 127B is replenished.

(Hydraulic shock absorber 200) (FIGS. 18 and 20)
The only difference between the hydraulic shock absorber 200 and the hydraulic shock absorber 100 is that the compression side piston / valve assembly 101A in the hydraulic shock absorber 100 is changed to the expansion side piston / valve assembly 201A as shown in FIG.

  That is, the hydraulic shock absorber 200 has the above-described extension-side piston / valve assembly 201 </ b> A in order to suppress the expansion and contraction vibration of the suspension spring 134 and the air spring of the air chamber 129.

  As shown in FIGS. 19 and 20, the expansion side piston / valve assembly 201A includes an expansion side piston / valve assembly 201A provided at the tip of the piston rod 124 (piston bolt 124A) of the damper 120. Inverted in the solid 101A.

  The expansion side valve assembly 201A has a valve stopper 140A, a valve guide 144, a valve collar 140B, a valve spring 143, an annular shape, which are the same as the components of the compression side piston / valve assembly 101A at the small diameter portion of the piston bolt 124A. The valve 142, the disk valve (extension side valve) 141, and the piston 126 are inserted in this order, and these are held by the nut 124B.

  The piston 126 includes a piston ring that slidably contacts the inner periphery of the damper cylinder 121, and the interior of the damper cylinder 121 is partitioned into the piston rod side oil chamber 127A and the piston side oil chamber 127B as described above, and is shown in FIG. As described above, the pressure increasing common oil passage 145 that connects the piston rod side oil chamber 127A and the piston side oil chamber 127B is provided. The disc valve 141 and the annular valve 142 are provided so as to move in the axial direction on the outer periphery of the valve collar 140B and to be movable in the axial direction with respect to the opening at the upper end of the pressure expansion common oil passage 145. Is generated.

  The valve spring 143 is supported on the back by a valve guide 144, and presses the annular valve 142 and the disk valve 141 against the valve seat 126A formed on the outer peripheral side of the oil passage 145 on the upper end surface of the piston 126 by its urging force. The disc valve 141 is bent and deformed so that the inner peripheral side thereof contacts and separates from the annular valve 142 while the outer periphery is cantilevered between the valve seat 126A of the piston 126 and the annular valve 142. Open and close the hole-shaped opening 142A. The annular valve 142 has a plurality of hole-like openings 142 </ b> A that are opened and closed by the disk valve 141.

  The annular valve 142 and the disc valve 141 constitute an extension side valve assembly 201B (extension side damping force generating means).

  Therefore, in the extension side piston / valve assembly 201A, when extending, the hydraulic pressure of the piston rod side oil chamber 127A is applied to the disc valve 141 from the opening 142A of the annular valve 142 to bend and deform the disc valve 141 (in other words, By generating an extension side damping force), the oil in the piston rod side oil chamber 127A flows through the oil passage 145 of the piston 126 to the piston side oil chamber 127B. Further, during compression, the oil pressure of the piston side oil chamber 127B is applied to the disk valve 141 and the annular valve 142, and the disk valve 141 and the annular valve 142 are moved upward against the urging force of the valve spring 143, so that the piston side oil chamber The oil of 127B is caused to flow into the piston rod side oil chamber 127A through the oil passage 145 through a path that bypasses the disk valve 141 that is the valve means for generating the extension side damping force.

  In the same way as the compression side piston / valve assembly 101A, the extension side piston / valve assembly 201A bypasses the piston 126 inside the piston rod 124 (piston bolt 124A) and the piston rod side oil chamber 127A and the piston side oil. A bypass oil passage 146 that allows the chamber 127B to communicate is provided, and the bypass oil passage 146 can be opened and closed by a needle valve 147A. At this time, the damping force adjuster 147 is screwed into the center of the sleeve 123 provided in the cap 116, the damping force adjuster 147 is inserted into the hollow portion of the piston rod 124, and the needle valve 147A is provided at the insertion end.

  The needle valve 147A provided in the expansion side piston / valve assembly 201A of the hydraulic shock absorber 200 functions as an expansion side damping force adjusting device.

  The other hydraulic shock absorber 200 is provided with a hole-shaped oil passage 170 for volume compensation of the piston rod 124, which communicates the piston-side oil chamber 127 </ b> B and the oil reservoir chamber 128 on the side wall on the lower end side of the damper cylinder 121. .

Accordingly, the hydraulic shock absorber 200 operates as follows.
(Compression process)
When the hydraulic shock absorber 200 is compressed, the vehicle body side tube 111 and the wheel side tube 112 are relatively compressed, and the suspension spring 134 is compressed. Further, the piston rod 124 enters the damper cylinder 121, and the oil in the piston-side oil chamber 127B pushes the disk valve 141 and the annular valve 142 of the pressure increase common oil passage 145 of the piston 126 into the piston rod-side oil chamber 127A. Flowing.

  When the hydraulic shock absorber 200 is compressed, the oil corresponding to the volume of the piston rod 124 entering the damper cylinder 121 is discharged from the piston-side oil chamber 127 </ b> B through the oil passage 170 of the damper cylinder 121 to the oil reservoir chamber 128.

(Extension process)
When the hydraulic shock absorber 200 is extended, the vehicle body side tube 111 and the wheel side tube 112 are relatively extended, and the suspension spring 134 is extended. Also, the piston rod 124 retreats from the damper cylinder 121, and the oil in the piston rod side oil chamber 127A flows into the piston side oil chamber 127B through the bypass oil passage 146 of the piston 126 at a low speed, and the throttle of the needle valve 147A during this period Stretch side damping force is obtained by resistance. Further, at medium and high speeds, the oil in the piston rod side oil chamber 127A flows into the piston side oil chamber 127B through the disk valve 141 of the pressure increase common oil passage 145 of the piston 126, and the deflection side of the disk valve 141 during this time causes the expansion side. Get damping force. The extension side damping force prevents the suspension spring 134 from resonating.

  When the hydraulic shock absorber 200 is fully extended, the rebound spring 139 backed up and supported by the spring receiver 138 locked to the inner peripheral portion of the upper end of the damper cylinder 121 is compressed by the upper end flange of the piston bolt 124A to restrict the maximum extension stroke. To do.

  When the hydraulic shock absorber 200 is extended, oil corresponding to the retraction volume of the piston rod 124 from the damper cylinder 121 is supplied from the oil reservoir chamber 128 to the piston-side oil chamber 127 </ b> A through the oil passage 170 of the damper cylinder 121.

  Therefore, in the hydraulic shock absorber 1, the compression side piston / valve assembly 101A of the hydraulic shock absorber 100 generates a compression side damping force during the compression stroke, and the expansion side piston / valve assembly 201A of the hydraulic shock absorber 200 during the expansion stroke. The expansion-and-contraction vibration of the suspension spring 134 is suppressed by the extension side damping force generated.

According to the present embodiment, the following operational effects can be obtained.
(a) “A common oil passage 145 is provided in the piston 126 of the hydraulic shock absorber 100 on one side, and a pressure side valve assembly 101B comprising an annular valve 142 and a disk valve 141 is provided at the lower end of the oil passage 145. By providing the (pressure-side damping force generating means) so as to be movable in the axial direction, a damping force is generated substantially only during compression, and the piston rod 124 that is always open to the oil reservoir chamber 128 is opened in the piston rod-side oil chamber 127A. In the hydraulic shock absorber 100 on one side, the hydraulic oil in the piston-side oil chamber 127B that shrinks during the compression stroke is reduced in the cross-sectional area of the piston 126 (of the piston rod 124). A considerable amount of hydraulic oil (including the cross-sectional area) passes through the pressure side valve assembly 101B (annular valve 142, disk valve 141) of the piston 126, and the upper piston. It flows to the head-side oil chamber 127A, further, through the oil passage 150 for volume compensation of the piston rod 124 which always open to the oil reservoir chamber 128 (the opening), flows into the oil reservoir chamber 128.

  Therefore, even if the oil passage 150 for volume compensation is provided in the piston rod side oil chamber 127A, the operation of the piston rod 124 is not hindered. In addition, since the pressure side valve assembly 101B of the piston 126 generates a pressure side damping force for the hydraulic oil corresponding to the entry volume of the piston rod 124, a pressure side base valve device provided at the bottom of the damper cylinder 121 (inner cylinder). Can be abolished.

  (b) “A common oil passage 145 is provided in the piston 126 of the hydraulic shock absorber 200 on the other side, and an opening side valve assembly 201B (annular valve 142, disk valve 141 is provided in the upper end opening of the oil passage 145. ) ”Is provided so as to be movable in the axial direction, so that a damping force is generated substantially only when extended, and the oil for compensating the volume of the piston rod 124 that is always open to the oil reservoir 128 is provided in the piston-side oil chamber 127B. A path 170 was provided. Therefore, since the hydraulic shock absorber 200 on the other side does not generate a compression side damping force at all or substantially, the compression side base valve device can be eliminated.

  (c) “A common oil passage 145 is provided in the piston 126 of the hydraulic shock absorber 100 on one side, and the pressure side valve assembly 101B (annular valve 142, disk valve 141) is provided at the opening at the lower end of the oil passage 145. Is provided so as to be movable in the axial direction, and a common oil passage 145 is provided in the piston 126 of the hydraulic shock absorber 200 on the other side, and the opening side valve assembly 201B (annular valve) is formed in the opening at the upper end of the oil passage 145. 142, the disc valve 141) is provided so as to be movable in the axial direction. "From the piston 126 on one side (compression side), the pressure side valve assembly 101B is arranged only at the lower end portion, and the other side (extension side). ) Is provided with the expansion side valve assembly 201B only at its upper end, so that the overall arrangement of the valves can be simplified and the number of valves can be reduced. Therefore, the cost can be reduced.

  (d) Since the piston 126 is provided with only the oil passage 145 common to the pressure increase, as in Patent Document 1, the area of the oil passage is larger than when the pressure side oil passage and the extension side oil passage are provided in the piston. The area of the hole-shaped opening 142A of the annular valve 142 is not limited, and the area of the oil passage necessary for the small-diameter piston 126 can be secured even if the piston 126 has a small diameter. The degree of freedom can be improved.

  In the hydraulic shock absorber 100 on one side of this embodiment, “always opening” the volume compensating oil passage 150 of the piston rod 124 is not blocked by the piston even at the maximum extension, It means opening directly to the oil reservoir without going through the gas chamber. This is because when the gas chamber is opened, the air in the gas chamber is sucked when the gas chamber is extended. Further, the opening of the volume compensating oil passage 170 of the piston rod 124 in the hydraulic shock absorber 200 on the other side of the present invention does not need to generate a compression side damping force at the opening, and therefore, when the oil passage 170 is extended to the oil passage 170. The size can be set taking into consideration only the suction property.

  Further, the vehicle to which the present invention is applied is a four-wheeled vehicle, regardless of a motorcycle, as long as the outer cylinder side of the hydraulic shock absorber is attached to a common axle or an axle-side member having a common axle. May be. That is, it is sufficient if the left and right hydraulic shock absorbers are interlocked in synchronization with the left and right.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention.

FIG. 1 is an overall view showing a hydraulic shock absorber for a vehicle according to a first embodiment. FIG. 2 is a cross-sectional view showing one of the left and right hydraulic shock absorbers. FIG. 3 is an enlarged view of a main part of FIG. 4A and 4B show the pressure side piston / valve assembly, in which FIG. 4A is an overall cross-sectional view and FIG. FIG. 5 shows the components of the compression side piston / valve assembly, (A) is a plan view showing the annular valve, (B) is a sectional view showing the disc valve, and (C) is a plan view showing a modification of the annular valve. It is. 6A and 6B show the operating state of the compression side piston / valve assembly. FIG. 6A is a sectional view showing a compressed state, and FIG. 6B is a sectional view showing an extended state. FIG. 7 is a cross-sectional view showing the left and right hydraulic shock absorbers. FIG. 8 is an enlarged view of a main part of FIG. FIG. 9 shows an extension side piston / valve assembly, (A) is an overall cross-sectional view, and (B) is an enlarged view of a main part. 10A and 10B show the operating state of the expansion side piston / valve assembly, where FIG. 10A is a sectional view showing an extended state, and FIG. 10B is a sectional view showing a compressed state. FIG. 11 is an overall view showing a hydraulic shock absorber for a vehicle according to the second embodiment. FIG. 12 is a cross-sectional view showing one of the left and right hydraulic shock absorbers. FIG. 13 is an enlarged view of a main part of FIG. 14A and 14B show a compression side piston / valve assembly, in which FIG. 14A is an overall cross-sectional view and FIG. FIG. 15 shows a piston, (A) is a sectional view, and (B) is a plan view. FIG. 16 is a plan view showing the disk valve. FIG. 17 shows a check valve, where (A) is a cross-sectional view and (B) is a plan view. FIG. 18 is a cross-sectional view showing the left and right hydraulic shock absorbers. FIG. 19 is an enlarged view of a main part of FIG. 20A and 20B show an expansion side piston / valve assembly, where FIG. 20A is an overall cross-sectional view and FIG.

Explanation of symbols

1 Hydraulic shock absorber 11 Outer cylinder 12 Inner cylinder 15 Piston rod 32 Piston 34 Disc valve (pressure side valve, extension side valve)
35 Annular valve 35A Opening 41A Piston rod side oil chamber 41B Piston side oil chamber 42 Pressure expansion common oil passage 43 Oil reservoir chamber 44 Gas chamber 50 Volume compensation oil passage 70 Volume compensation oil passage 100, 200 Hydraulic buffer 101A Pressure side piston / valve assembly 101B Pressure side valve assembly 112 Wheel side tube (outer cylinder)
121 Damper cylinder (inner cylinder)
124 piston rod 126 piston 127A piston rod side oil chamber 127B piston side oil chamber 128 oil reservoir chamber 129 gas chamber 141 disk valve (pressure side valve, extension side valve)
142 Annular valve 142A Opening 145 Pressure expansion common oil path 150 Volume compensation oil path 170 Volume compensation oil path 201A Extension side piston / valve assembly 201B Extension side valve assembly 300 Annular valve (pressure side valve, extension side valve) )
301 Orifice hole

Claims (3)

Install hydraulic shock absorbers on the left and right of the wheel
In the vehicle hydraulic shock absorber, in which only the compression side damping force is substantially generated in the one side hydraulic shock absorber, and only the expansion side damping force is substantially generated in the other side hydraulic shock absorber,
The hydraulic shock absorber on one side is
While having an outer cylinder attached to the wheel side and an inner cylinder provided in the outer cylinder,
Having a piston that slides in the inner cylinder at the tip, and a piston rod attached to the vehicle body side;
While providing a piston rod side oil chamber and a piston side oil chamber partitioned by the piston in the inner cylinder,
An oil reservoir and a gas chamber above the oil reservoir are provided between the inner cylinder and the outer cylinder,
By providing an oil passage common to the piston of the hydraulic shock absorber on one side and providing a pressure side valve or a pressure side valve assembly movably in the axial direction at the opening at the lower end of the oil passage, A damping force is generated only during compression,
The piston rod side oil chamber is provided with an oil passage for volume compensation of the piston rod that is always open to the oil reservoir chamber,
By providing an oil passage common to the piston of the hydraulic shock absorber on the other side and providing an extension side valve or extension side valve assembly in the opening at the upper end of the oil passage so as to be movable in the axial direction. In addition to generating damping force only when stretched,
A hydraulic shock absorber for a vehicle, wherein an oil passage for volume compensation of a piston rod that is always open to the oil reservoir chamber is provided in the piston-side oil chamber.   2. The vehicle hydraulic shock absorber according to claim 1, wherein the pressure side valve assembly or the extension side valve assembly includes an annular valve having an opening and a disk valve provided adjacent to the piston side of the annular valve.   2. The hydraulic shock absorber for a vehicle according to claim 1, wherein the pressure side valve or the extension side valve is an annular valve provided with an orifice hole.

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