JP4137540B2 - Hydraulic shock absorber for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic shock absorber for a vehicle.
[0002]
[Prior art]
2. Description of the Related Art Some vehicle hydraulic shock absorbers are provided with hydraulic shock absorbers on the left and right sides of wheels. Each hydraulic shock absorber is provided with two oil passages in the piston that slides in the cylinder, as described in Japanese Utility Model Publication No. 64-41495, and an extension side damping valve that generates an extension side damping force in one oil passage. And an extension side damping force generator provided with a compression side check valve that easily opens to the other oil passage during compression and generates little or no compression side damping force, and two sub-pistons fixed to the bottom of the cylinder have two An oil passage is provided, and a compression-side damping valve that generates a compression-side damping force for hydraulic oil equivalent to the piston rod entry volume is provided in one of the oil passages. It has a compression side damping force generator provided with an extension side check valve that is not generated.
[0003]
[Problems to be solved by the invention]
In the prior art, both of the hydraulic shock absorbers provided on both sides of the wheel are an extension side damping force generator provided on a piston sliding in the cylinder, and a compression side damping force generator provided on a sub-piston fixed to the bottom of the cylinder. have. For this reason, the damping valve structure of each hydraulic shock absorber is complicated and the number of parts increases, and the manufacturing cost cannot be reduced.
[0004]
An object of the present invention is to simplify a damping valve structure of each hydraulic shock absorber and reduce manufacturing cost in a hydraulic shock absorber provided with hydraulic shock absorbers on the left and right sides of a wheel.
[0005]
[Problems to be solved by the invention]
According to the first aspect of the present invention, in a vehicle hydraulic shock absorber provided with hydraulic shock absorbers on the left and right sides of the wheel, one hydraulic shock absorber is provided with a compression side damping force generating means for mainly generating a compression side damping force, and the other hydraulic shock absorber is provided. An extension side damping force generating means for mainly generating an extension side damping force is provided in the container so that the generation of the compression side damping force and the extension side damping force is shared between the left and right hydraulic shock absorbers, It consists of a vehicle body side tube and a wheel side tube that are slidably fitted, a damper cylinder, and a piston rod with a piston that slides inside the damper cylinder attached to the tip, and the damper cylinder is mounted in the wheel side tube. A damper having the piston rod mounted in the vehicle body side tube, a piston rod side oil chamber and a piston side oil chamber defined by the piston in the damper cylinder, and an outer periphery of the damper cylinder. And an oil reservoir chamber was provided with two oil passage provided in the piston, and the compression side damping valve provided on one oil passage of said, is provided at the other oil passage, and a check valve that opens when stretched closed during compression, As an oil path for volume compensation of the piston rod, only an oil path that always communicates the piston rod side oil chamber and the oil reservoir chamber is provided.
[0006]
The invention according to claim 2 is provided with hydraulic shock absorbers on both the left and right sides of the wheel, each hydraulic shock absorber slidably fits the vehicle body side tube and the wheel side tube, and slides within the damper cylinder and the damper cylinder. It has a damper consisting of a piston rod attached to the tip of a moving piston, the damper cylinder is installed in the wheel side tube, the piston rod is installed in the vehicle body side tube, and the piston rod is accommodated on both sides of the piston A piston rod-side oil chamber and a piston-side oil chamber that does not accommodate the piston rod are divided, and two oil passages that communicate the two oil chambers are provided in the piston, and the volume of the piston rod is provided on the outer periphery of the damper cylinder In a hydraulic shock absorber for a vehicle configured to provide a compensation oil reservoir, one hydraulic shock absorber includes a pressure side damping in one oil passage of the piston. Provided Lube, provided the check valve that opens when stretched closed during compression in the other oil passage, and, constantly communicating the oil reservoir chamber and the piston rod side oil chamber as the oil path for volume compensation of the piston rod oil The other hydraulic shock absorber is provided with an extension side damping valve in one oil passage of the piston , a check valve is provided in the other oil passage and is closed when the piston is extended, and is opened when compressed . As an oil path for volume compensation, only an oil path that always communicates the piston-side oil chamber and the oil reservoir chamber is provided.
[0007]
According to a third aspect of the present invention, in the first or second aspect of the present invention, a bypass oil passage communicating the oil chambers on both sides of the piston is provided in the piston rod of each hydraulic shock absorber, and the damping force is adjusted in the bypass oil passage. A valve is provided.
[0008]
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, an oil passage of the one hydraulic shock absorber is formed on a side wall of the damper cylinder.
[0009]
According to a fifth aspect of the present invention, in the invention according to any one of the first to third aspects, an oil passage of the one hydraulic shock absorber is provided in a guide member that guides the piston rod.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
1 is an overall view showing one of the left and right hydraulic shock absorbers, FIG. 2 is an enlarged view of the main part of FIG. 1, FIG. 3 shows a modification in which an oil passage is provided in the rod guide, (A) is a sectional view, (B ) Is a plan view of the bush, FIG. 4 is an overall view showing the left and right hydraulic shock absorbers, and FIG. 5 is an enlarged view of a main part of FIG.
[0011]
The 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 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.
[0012]
One of the left and right hydraulic shock absorbers 100 is configured as shown in FIGS. 1 to 3, and the other left and right hydraulic shock absorbers 200 are configured as shown in FIGS. 4 and 5. The hydraulic shock absorber 1 is provided with a compression-side damping force generating means 101 that mainly generates a compression-side damping force in one hydraulic shock absorber 100, and an expansion-side damping force that mainly generates an expansion-side damping force in the other hydraulic shock absorber 200. The generating means 201 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.
[0013]
(Hydraulic shock absorber 100) (FIGS. 1 to 3)
As shown in FIG. 1, the hydraulic shock absorber 100 is configured by fitting a vehicle body side tube 11 and a wheel side tube 12 in a fluid-tight manner so as to be slidable. A bush 13 is provided on the outer periphery of the lower end of the vehicle body side tube 11, and a bush 14 is provided on the inner periphery of the upper end side of the wheel side tube 12. An oil hole 11 </ b> A is provided on the lower end side of the vehicle body side tube 11 to communicate an oil reservoir chamber 28, which will be described later, between the vehicle body side tube 11 and the wheel side tube 12 in an annular gap sandwiched between the bushes 13 and 14.
[0014]
The vehicle body side tube 11 is provided with a cap 16 detachably and liquid-tightly at the opening 15 at the upper end, and the vehicle body side tube 11 is provided with a vehicle body side mounting portion. The axle-side tube 12 is integrally provided with a bottom bracket 18 at a lower end portion, and an axle-side mounting portion 19 is provided on the bottom bracket 18.
[0015]
The hydraulic shock absorber 100 accommodates a damper cylinder 21 and a piston rod 24 that constitute the damper 20 inside the vehicle body side tube 11 and the wheel side tube 12. That is, the hydraulic shock absorber 100 has a damper cylinder 21 fixed inside the bottom bracket 18 erected inside the wheel side tube 12. A center ring 22 attached to the bottom of the bottom bracket 18 pulls a stopper ring 22A engaged with the inner periphery of the lower end of the damper cylinder 21 so that the damper cylinder 21 is moved under the flange 37A of an oil lock piece 37 described later. It is fixed to the bottom. In the front fork 10, a spring load adjusting sleeve 23 is screwed in a liquid tight manner at the center of the cap 16, and a hollow piston rod 24 and a lock nut 23 </ b> A are provided at the lower end of the spring load adjusting sleeve 23 inserted into the vehicle body side tube 11. And the piston rod 24 is fixedly supported to the vehicle body side tube 11. The piston rod 24 slidably passes through a rod guide 25 provided at the upper end of the damper cylinder 21 and is inserted into an oil chamber 27 inside the damper cylinder 21, and is connected to a piston bolt 24 </ b> A provided at the insertion tip of the piston rod 24. 26. The piston 26 is fixed by a nut 24B screwed to the piston bolt 24A. The piston 26 slides up and down on the inner surface of the damper cylinder 21. The oil chamber 27 is partitioned by the piston 26 into a piston rod side oil chamber 27A on the side where the piston rod 24 is inserted and a piston side oil chamber 27B on the side where the piston rod 24 is not inserted.
[0016]
The rod guide 25 is provided with an inner collar 25E fitted with an O-ring 25D inside upper and lower washers 25A, 25B and an outer collar 25C which are caulked and fixed to the upper end of the damper cylinder 21, and a bush which is press-fitted into the inner collar 25E. The piston rod 24 is slidably supported by 25F. The O-ring 25D absorbs the axial misalignment between the damper cylinder 21 and the piston rod 24. The inner collar 25E and the bush 25F may move up and down between the upper and lower washers 25A and 25B, or may be fixed so as not to move up and down.
[0017]
In the hydraulic shock absorber 100, the space around the damper cylinder 21 between the vehicle body side tube 11 and the wheel side tube 12 is an oil reservoir chamber 28, and the upper portion of the oil reservoir chamber 28 is a gas chamber (air chamber) 29.
[0018]
The hydraulic shock absorber 100 includes a spring collar 31 formed by a combination of a plurality of members that are supported by the aforementioned spring load adjusting sleeve 23 provided on the cap 16 and moved up and down, and an upper spring seat 32 that is backed up by the spring collar 31. A suspension spring 34 is interposed between the lower spring seat 33 fixed to the outer periphery of the upper end portion of the damper cylinder 21.
[0019]
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 34 and the spring reaction force of the air spring of the air chamber 29.
[0020]
The hydraulic shock absorber 100 includes the above-described compression-side damping force generating means 101 in order to suppress the expansion and contraction vibration of the suspension spring 34 and the air spring of the air chamber 29.
[0021]
As shown in FIG. 2, the compression-side damping force generating means 101 includes a compression-side oil passage 41 and an extension side that allow the piston rod-side oil chamber 27 </ b> A and the piston-side oil chamber 27 </ b> B to communicate with the piston 26 that is in sliding contact with the inner surface of the damper cylinder 21. A flow path 42 is provided, and the pressure side oil path 41 can be opened and closed by a pressure side damping valve 43, and the extension side flow path 42 can be opened and closed by a check valve 44. The compression-side damping valve 43 is backed up and supported by a valve stopper 43A that is locked by the piston rod 24. The check valve 44 is backed up and supported by a valve spring 44B held by a spring receiver 44A fixed by a nut 24B, and closes when compressed and opens when extended.
[0022]
Further, the compression-side damping force generating means 101 has a bypass passage 46 in the piston rod 24 (piston bolt 24A) that bypasses the piston 26 and allows the piston rod-side oil chamber 27A and the piston-side oil chamber 27B to communicate with each other. And the bypass channel 46 can be opened and closed by a needle valve 47A. At this time, the damping force adjusting rod 47 is screwed into the center of the spring load adjusting sleeve 23 provided on the cap 16, the damping force adjusting rod 47 is inserted into the hollow portion of the piston rod 24, and the needle valve 47A described above is inserted into the insertion end. Is provided.
[0023]
The needle valve 47A provided in the compression side damping force generating means 101 of the hydraulic shock absorber 100 functions as a compression side damping force adjusting device.
[0024]
The compression-side damping force generating means 101 is provided with a hole-shaped oil passage 50 for volume compensation of the piston rod 24, which communicates the piston rod-side oil chamber 27 </ b> A and the oil reservoir chamber 28 on the side wall on the upper end side of the damper cylinder 21. Yes.
[0025]
Accordingly, the hydraulic shock absorber 100 operates as follows.
(Compression process)
When the hydraulic shock absorber 100 is compressed, the vehicle body side tube 11 and the wheel side tube 12 are relatively compressed, and the suspension spring 34 is compressed. Also, the piston rod 24 enters the damper cylinder 21, and the oil in the piston-side oil chamber 27B flows into the piston rod-side oil chamber 27A through the bypass oil passage 46 of the piston 26 at a low speed. The compression side damping force is obtained by resistance. Further, at medium and high speeds, the oil in the piston side oil chamber 27B flows into the piston rod side oil chamber 27A through the pressure side damping valve 43 of the pressure side oil passage 41 of the piston 26, and the pressure side damping is caused by the deflection resistance of the pressure side damping valve 43 during this period. Gain power. The spring force of the suspension spring 34 buffers an impact during compression, and the compression side damping force controls the compression speed of the suspension spring 34.
[0026]
When the hydraulic shock absorber 100 is most compressed, the check valve 36A of the oil lock collar 36 provided at the lower end of the vehicle body side tube 11 is fitted to the outer periphery of the oil lock piece 37 erected on the bottom of the wheel side tube 12. Then, an oil lock oil chamber is defined between the wheel side tube 12 and the oil lock piece 37 to restrict the maximum compression stroke.
[0027]
When the hydraulic shock absorber 100 is compressed, the oil corresponding to the volume of the piston rod 24 entering the damper cylinder 21 is discharged from the piston rod side oil chamber 27 </ b> A through the oil passage 50 of the damper cylinder 21 to the oil reservoir chamber 28.
[0028]
(Extension process)
When the hydraulic shock absorber 100 is extended, the vehicle body side tube 11 and the wheel side tube 12 are relatively extended, and the suspension spring 34 is extended. Further, the piston rod 24 retreats from the damper cylinder 21, and the oil in the piston rod side oil chamber 27A pushes open the check valve 44 of the extension side oil passage 42 of the piston 26 and flows into the piston side oil chamber 27B.
[0029]
When the hydraulic shock absorber 100 is fully extended, the rebound spring 39 backed up and supported by the spring receiver 38 locked to the outer periphery of the upper end of the damper cylinder 21 is compressed by the upper end washer of the oil lock collar 36 to restrict the maximum extension stroke. To do.
[0030]
When the hydraulic shock absorber 100 is extended, oil corresponding to the retracted volume of the piston rod 24 from the damper cylinder 21 is supplied from the oil reservoir chamber 28 to the piston rod side oil chamber 27 </ b> A through the oil passage 50 of the damper cylinder 21.
[0031]
In the hydraulic shock absorber 100, the oil passage 50 provided for volume compensation of the piston rod 24 is a rod guide 51 (described above) provided at the upper end of the damper cylinder 21 so as to guide the piston rod 24 as shown in FIG. (Corresponding to the rod guide 25). The rod guide 51 accommodates a bush 51D through an annular gap inside upper and lower washers 51A, 51B and an outer collar 51C that are caulked and fixed to the upper end of the damper cylinder 21, and a plurality of circumferentially arranged upper and lower end surfaces of the bush 51D. Oil grooves 51E and 51F are provided at the position over the entire length in the radial direction. The bush 51D may move up and down between the upper and lower washers 51A and 51B, or may be fixed so as not to move up and down. The oil passage 50 is formed by a gap formed by the inner circumferences of the upper and lower washers 51A and 51B with respect to the outer circumference of the piston rod 24, upper and lower oil grooves 51E and 51F, and an annular gap between the outer collar 51C and the bush 51D.
[0032]
(Hydraulic shock absorber 200) (FIGS. 4 and 5)
The hydraulic shock absorber 200 is different from the hydraulic shock absorber 100 only in that the compression side damping force generating means 101 in the hydraulic shock absorber 100 is changed to the extension side damping force generating means 201 as shown in FIG.
[0033]
That is, the hydraulic shock absorber 200 has the above-described extension side damping force generation means 201 in order to suppress the expansion and contraction vibration of the suspension spring 34 and the air spring of the air chamber 29.
[0034]
As shown in FIG. 5, the extension-side damping force generating means 201 reverses the piston 26 provided in the piston bolt 24 </ b> A of the piston rod 24 as compared with the compression-side damping force generating means 101 of the hydraulic shock absorber 101. That is, the extension side damping force generating means 201 is connected to the piston 26 slidably contacting the inner surface of the damper cylinder 21 so that the piston rod side oil chamber 27A and the piston side oil chamber 27B can communicate with each other. The extension side oil passage 61 can be opened and closed by the extension side damping valve 63, and the compression side oil passage 62 can be opened and closed by the tick valve 64. The expansion side damping valve 63 is backed up and supported by a valve stopper 63A fixed by a nut 24B. The check valve 64 is backed up and supported by a valve spring 64B held by a spring receiver 64A locked by the piston rod 24, and closes when extended and opens when compressed.
[0035]
Similarly to the compression side damping force generation unit 101, the extension side damping force generation unit 201 bypasses the piston 26 inside the piston rod 24 (piston bolt 24A), and the piston rod side oil chamber 27A and the piston side oil chamber 27B. And the bypass oil passage 46 can be opened and closed by a needle valve 47A. At this time, the damping force adjusting rod 47 is screwed into the center of the spring load adjusting sleeve 23 provided on the cap 16, the damping force adjusting rod 47 is inserted into the hollow portion of the piston rod 24, and the needle valve 47A described above is inserted into the insertion end. Is provided.
[0036]
The needle valve 47A provided in the extension side damping force generating means 201 of the hydraulic shock absorber 200 functions as an extension side damping force adjusting device.
[0037]
The expansion-side damping force generating means 201 is provided with a hole-shaped oil passage 70 for volume compensation of the piston rod 24 that communicates the piston-side oil chamber 27B and the oil reservoir chamber 28 on the side wall on the lower end side of the damper cylinder 21. Yes.
[0038]
Accordingly, the hydraulic shock absorber 200 operates as follows.
(Compression process)
When the hydraulic shock absorber 200 is compressed, the vehicle body side tube 11 and the wheel side tube 12 are relatively compressed, and the suspension spring 34 is compressed. Further, the piston rod 24 enters the damper cylinder 21, and the oil in the piston side oil chamber 27B pushes open the check valve 64 of the pressure side oil passage 62 of the piston 26 and flows into the piston rod side oil chamber 27A.
[0039]
When the hydraulic shock absorber 200 is compressed most, the check valve 36A of the oil lock collar 36 provided at the lower end portion of the vehicle body side tube 11 is fitted to the outer periphery of the oil lock piece 37 standing on the bottom of the wheel side tube 12. Then, an oil lock oil chamber is defined between the wheel side tube 12 and the oil lock piece 37 to restrict the maximum compression stroke.
[0040]
When the hydraulic shock absorber 200 is compressed, the oil corresponding to the volume of the piston rod 24 entering the damper cylinder 21 is discharged from the piston rod side oil chamber 27 </ b> B through the oil passage 70 of the damper cylinder 21 to the oil reservoir chamber 28.
[0041]
(Extension process)
When the hydraulic shock absorber 200 is extended, the vehicle body side tube 11 and the wheel side tube 12 are relatively extended, and the suspension spring 34 is extended. Also, the piston rod 24 retreats from the damper cylinder 21, and the oil in the piston rod side oil chamber 27A flows into the piston side oil chamber 27B through the bypass oil passage 46 of the piston 26 at a low speed. Stretch side damping force is obtained by resistance. Further, at medium and high speeds, the oil in the piston rod side oil chamber 27A flows into the piston side oil chamber 27B through the extension side damping valve 63 of the extension side oil passage 61 of the piston 26, and the deflection resistance of the extension side damping valve 63 during this period. Thus, the extension side damping force is obtained. The extension side damping force prevents the suspension spring 34 from resonating.
[0042]
When the hydraulic shock absorber 200 is fully extended, the rebound spring 39 backed up and supported by the spring receiver 38 locked to the outer periphery of the upper end of the damper cylinder 21 is compressed by the upper end washer of the oil lock collar 36 to restrict the maximum extension stroke. To do.
[0043]
When the hydraulic shock absorber 200 is extended, oil corresponding to the retraction volume of the piston rod 24 from the damper cylinder 21 is replenished from the oil reservoir chamber 28 through the oil passage 70 of the damper cylinder 21 to the piston-side oil chamber 27A.
[0044]
Therefore, in the hydraulic shock absorber 1, the compression side damping force generated by the compression side damping force generation means 101 of the hydraulic shock absorber 100 is generated in the compression step, and the expansion side damping force generation means 201 of the hydraulic shock absorber 200 is generated in the expansion step. The expansion and contraction vibration of the suspension spring 34 is suppressed by the extending side damping force.
[0045]
According to this embodiment, there are the following operations.
(Operation corresponding to claim 1)
(1) The hydraulic shock absorber 100 on the side that generates the compression side damping force generates the compression side damping force by the compression side damping valve 43 provided on the piston 26 that slides inside the damper cylinder 21. Therefore, it is not necessary for the hydraulic shock absorber 100 on the side that generates the compression side damping force to have a compression side damping force generation device in which the compression side damping valve and the extension side check valve are provided on the sub-piston fixed to the bottom of the damper cylinder 21. Manufacturing cost can be reduced.
[0046]
(2) In the hydraulic shock absorber 100, an oil passage 50 for volume compensation of the piston rod 24 is provided to communicate the piston rod side oil chamber 27A inside the damper cylinder 21 with the oil reservoir chamber 28 outside the damper cylinder 21. . Therefore, when compressed, the hydraulic oil in the piston side oil chamber 27B passes through the pressure side damping valve 43 and reaches the piston rod side oil chamber 27A, and further through the oil passage 50, the oil reservoir chamber outside the damper cylinder 21. 28 flows.
[0047]
Therefore, compared with the case where the volume compensation oil passage 50 is provided on the piston side oil chamber 27B side, the hydraulic oil passes through the full pressure side damping valve 43, and a stable compression side damping force can be generated.
[0048]
When the oil passage 50 for volume compensation is provided on the piston side oil chamber 27B side, the pressure side damping valve 43 of the piston 26 and the oil passage 50 on the piston side oil chamber 27B constitute a parallel flow path. It becomes difficult to set the size of the oil passage 50 on the piston side oil chamber 27B side, and the generation of the compression side damping force is not stable.
[0049]
(Operation corresponding to claim 2)
(3) In addition to the above (1) and (2), the hydraulic shock absorber 200 on the side that generates the extension side damping force is also provided with a compression side damping valve and an extension side check valve on the sub-piston fixed to the bottom of the damper cylinder 21. It is not necessary to have a pressure-side damping force generator, and the manufacturing cost can be reduced.
[0050]
(Operation corresponding to claim 3)
(4) A damping force adjusting valve (needle valve 47A) provided in the hydraulic shock absorber 100 on the side generating the compression side damping force works as a compression side damping force adjusting device. The damping force adjustment valve (needle valve 47A) provided in the hydraulic shock absorber 200 on the side that generates the extension side damping force works as an extension side damping force adjustment device. Accordingly, the damping force adjustment of the hydraulic shock absorbers 100 and 200 can be made independent of each other.
[0051]
In the prior art, both the left and right hydraulic shock absorbers 100 and 200 are provided with both the extension side damping force adjusting device and the compression side damping force adjusting device. Therefore, when adjusting the compression side damping force, the left and right pressure side damping forces are adjusted. It is necessary to adjust the adjustment device, and it is necessary to adjust the same amount on the left and right sides.To adjust the extension side damping force, it is necessary to adjust the left and right extension side damping force adjustment devices. It is necessary to adjust the amount.
[0052]
(Operation corresponding to claim 4)
(5) Since the oil passage 50 is formed on the side wall of the damper cylinder 21, the structure is simplified and the cost can be reduced.
[0053]
(Operation corresponding to claim 5)
(6) Since the oil passage 50 is provided in the guide member (rod guide 51) of the piston rod 24, the dimensional accuracy of the size of the oil passage 50 can be increased.
[0054]
Although the embodiment of the present invention has been described with reference to the drawings, the specific configuration of the present invention is not limited to this embodiment, and there are design changes and the like without departing from the scope of the present invention. Are also included in the present invention.
[0055]
【The invention's effect】
As described above, according to the present invention, in the hydraulic shock absorber provided with the hydraulic shock absorbers on the left and right sides of the wheels, the damping valve structure of each hydraulic shock absorber can be simplified and the manufacturing cost can be reduced.
[Brief description of the drawings]
FIG. 1 is an overall view showing one of left and right hydraulic shock absorbers.
FIG. 2 is an enlarged view of a main part of FIG.
FIGS. 3A and 3B show a modified example in which an oil passage is provided in a rod guide. FIG. 3A is a cross-sectional view and FIG. 3B is a plan view of a bush.
FIG. 4 is an overall view showing the left and right hydraulic shock absorbers.
FIG. 5 is an enlarged view of a main part of FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hydraulic shock absorber 11 Car body side tube 12 Wheel side tube 20 Damper 21 Damper cylinder 24 Piston rod 26 Piston 27A Piston rod side oil chamber 27B Piston side oil chamber 28 Oil reservoir chamber 41 Pressure side oil passage 42 Extension side oil passage 43 Pressure side damping valve 44 Check valve 46 Bypass oil passage 47A Needle valve (damping force adjustment valve)
50 Oil passage 51 Rod guide (guide member)
61 Extension side oil passage 62 Pressure side oil passage 63 Extension side damping valve 64 Check valve 70 Oil passage 100 One hydraulic shock absorber 101 Compression side damping force generating means 200 The other hydraulic shock absorber 201 Extension side damping force generating means

Claims (5)

In a vehicle hydraulic shock absorber provided with hydraulic shock absorbers on the left and right of the wheel,
One hydraulic shock absorber is provided with a compression side damping force generating means for mainly generating a compression side damping force, and the other hydraulic shock absorber is provided with an expansion side damping force generating means for mainly generating an expansion side damping force. Let the left and right hydraulic shock absorbers share the generation of the extension side damping force,
The one hydraulic shock absorber is
A vehicle body side tube and a wheel side tube that are slidably fitted,
A damper cylinder, and a piston rod attached to the tip of a piston that slides in the damper cylinder, the damper cylinder attached in a wheel side tube, and a damper attached in the vehicle body side tube;
A piston rod side oil chamber and a piston side oil chamber partitioned by the piston in the damper cylinder;
An oil reservoir provided on the outer periphery of the damper cylinder;
Comprising two oil passages provided in the piston, a pressure-side damping valve provided in one of the oil passages, and a check valve provided in the other oil passage, which is closed when compressed and opened when extended, and compensates the volume of the piston rod hydraulic shock absorber for a vehicle, wherein a is provided only constantly oil passage communicating the oil passage and the piston rod side oil chamber and the oil reservoir chamber of use. Install hydraulic shock absorbers on both the left and right sides of the wheel,
Each hydraulic shock absorber
Fit the body side tube and wheel side tube slidably,
A damper cylinder and a damper composed of a piston rod attached to the tip of a piston that slides in the damper cylinder; the damper cylinder is mounted in a wheel side tube; the piston rod is mounted in a vehicle body side tube;
A piston rod side oil chamber that houses the piston rod on both sides of the piston and a piston side oil chamber that does not contain the piston rod;
The piston is provided with two oil passages communicating the two oil chambers,
In the vehicle hydraulic shock absorber configured to provide an oil reservoir for volume compensation of the piston rod on the outer periphery of the damper cylinder,
One hydraulic shock absorber is provided with a compression-side damping valve in one oil passage of the piston , a check valve is provided in the other oil passage and is closed when compressed and opened, and an oil passage for volume compensation of the piston rod. only oil passage constantly communicating the oil reservoir chamber and the piston rod side oil chamber is provided as,
The other hydraulic shock absorber is provided with an expansion-side damping valve in one oil passage of the piston , a check valve is opened in the other oil passage and is closed when it is extended, and oil for compensating the volume of the piston rod is provided. hydraulic shock absorber for a vehicle, characterized in that a only oil passage constantly communicating the oil reservoir chamber and the piston-side oil chamber as a road.   The hydraulic shock absorber for a vehicle according to claim 1 or 2, wherein a bypass oil passage that communicates oil chambers on both sides of the piston is provided in a piston rod of each hydraulic shock absorber, and a damping force adjusting valve is provided in the bypass oil passage. .   The hydraulic shock absorber for a vehicle according to any one of claims 1 to 3, wherein an oil passage of the one hydraulic shock absorber is formed on a side wall of the damper cylinder.   The hydraulic shock absorber for a vehicle according to any one of claims 1 to 3, wherein an oil passage of the one hydraulic shock absorber is provided in a guide member that guides the piston rod.

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