JPH08233017A - Hydraulic shock absorber - Google Patents

Abstract

(57) [Summary] [Purpose] To make it possible to set a large variable range of damping force characteristics and to facilitate attachment / detachment of a damping force adjusting mechanism to improve maintenance workability. [Structure] A piston 12 is installed in a cylinder 11 filled with hydraulic oil to define a cylinder, and these defining chambers 18A and 18B communicate with each other through a first flow path 22 formed outside the cylinder. In the hydraulic shock absorber 10 in which the compression-side damping force adjusting mechanism 15 for generating and adjusting the compression-side damping force and the expansion-side damping force adjusting mechanism 16 for generating and adjusting the expansion-side damping force are arranged in these flow paths and the like. The compression-side damping force adjusting mechanism and the extension-side damping force adjusting mechanism are arranged to face each other in the housing housing 14 installed in the cylinder independently of each other in the diameter direction of the cylinder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic shock absorber, and more particularly to a hydraulic shock absorber capable of expanding a variable range of damping force characteristics.

[0002]

2. Description of the Related Art A hydraulic shock absorber applied to a four-wheeled motor vehicle or a two-wheeled motor vehicle has a piston installed in a cylinder filled with hydraulic oil, as in the invention described in JP-A-6-221365. The inside of the cylinder is divided into two chambers, and these two chambers are communicated with each other by a flow path formed outside the cylinder, and a compression side damping force adjusting mechanism that generates and adjusts a compression side damping force in this flow path,
There is one in which an extension side damping force adjusting mechanism for generating and adjusting the extension side damping force is provided. The compression-side damping force adjusting mechanism and the extension-side damping force adjusting mechanism are arranged side by side on the upper connecting member installed in the cylinder in a direction orthogonal to the axial direction of the cylinder.

[0003]

In the above-mentioned hydraulic shock absorber, since the compression side damping force adjusting mechanism and the extension side damping force adjusting mechanism are arranged side by side in the direction orthogonal to the axial direction of the cylinder, these damping forces are not provided. The diameter of the adjusting mechanism cannot be increased, and therefore the variable width of the damping force characteristic cannot be set large.

The present invention has been made in consideration of the above-mentioned circumstances, and it is possible to set the variable width of the damping force characteristic to be large and to facilitate the attachment / detachment of the damping force adjusting mechanism to improve the workability of maintenance. An object of the present invention is to provide a hydraulic shock absorber capable of

[0005]

According to a first aspect of the present invention, a piston is installed in a cylinder filled with hydraulic oil to define the inside of the cylinder, and these defining chambers are provided outside the cylinder. A compression-side damping force adjusting mechanism that generates and adjusts a compression-side damping force and an expansion-side damping force adjusting mechanism that generates and adjusts a stretching-side damping force are provided in this flow path. In the hydraulic shock absorber, the compression side damping force adjusting mechanism and the extension side damping force adjusting mechanism are arranged to face each other in a diametrical direction of the cylinder independently of each other in a housing housing installed in the cylinder.

According to a second aspect of the present invention, in the invention according to the first aspect, a reservoir chamber is formed in the storage housing in the vicinity of the compression side damping force adjusting mechanism and the extension side damping force adjusting mechanism. is there.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the invention described in (1), the compression side damping force adjusting mechanism and the extension side damping force adjusting mechanism are mounted on one surface of the valve seat in which a plurality of oil holes having different flow passage areas are formed in the circumferential direction, respectively. And a shutter provided with a window portion rotatably installed on the other surface of the valve seat to selectively open the oil hole, the valve seat and the damping valve. A shutter operating portion that extends through the valve and the central portion of the shutter to the outside and that rotationally operates the shutter by an external operation, and a bypass flow formed by bypassing the attenuation valve in the shutter operating portion. And a needle valve that is installed in the bypass flow passage and that can change the flow passage area of the bypass flow passage by an operation from the outside. Damping valve, the shutter, the shutter operation section, the bypass flow passage and the needle valve is configured in the unit structure, in which a freely disposed detachably in the storage housing.

[0008]

The invention described in claim 1 has the following effects. Since the compression side damping force adjusting mechanism and the extension side damping force adjusting mechanism are arranged independently, the compression side damping force and the extension side damping force can be set completely independently.

Further, since the compression side damping force adjusting mechanism and the extension side damping force adjusting mechanism are arranged to face each other in the diameter direction of the cylinder, both damping force adjusting mechanisms are arranged side by side in the cylinder diameter direction. In comparison with the above case, the diameter of the damping valve and the valve seat arranged in each damping force adjusting mechanism can be increased, and the flow passage area of the oil hole formed in the valve seat can be set large. Therefore, the variable width of the damping force characteristic of each damping force adjusting mechanism can be set large, and the hydraulic shock absorber can be made compact accordingly.

The invention according to claim 2 has the following effects. Since the reservoir chamber is installed in the vicinity of the compression side damping force adjusting mechanism and the extension side damping force adjusting mechanism, the flow path that connects the reservoir chamber and both damping force adjusting mechanisms is not complicated, and there is no delay in the transmission of operating hydraulic pressure. The effect can be avoided.

The invention described in claim 3 has the following operation. A valve seat, a damping valve, a shutter, which constitute each of the compression side damping force adjusting mechanism and the extension side damping force adjusting mechanism.
Since the shutter operating portion, the bypass flow passage, and the needle valve are configured as a detachable unit structure, the damping force adjusting mechanism can be easily replaced, and the maintainability can be improved.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of a hydraulic shock absorber according to the present invention. FIG. 2 is an enlarged cross-sectional view showing a part of FIG. 1 in an enlarged manner. FIG. 3 is an enlarged cross-sectional view of the portion III in FIG. FIG. 4 is a sectional view of the valve seat of FIG. 2 taken along the line IV-IV in FIGS. 5 and 6. FIG. 5 is a view on arrow V in FIG. FIG. 6 is a view on arrow VI of FIG. FIG. 7 is an operation diagram showing an operation state of the shutter of FIG. Figure 8
It is a graph which shows the damping force characteristic by the hydraulic shock absorber of FIG.

The hydraulic shock absorber 10 is, as shown in FIG. 1, a cylinder 11, a piston 12, an outer cylinder 13, and a housing 1.
4, compression side damping force adjusting mechanism 15, extension side damping force adjusting mechanism 16
And a free piston 17.

The cylinder 11 is filled with hydraulic oil, and the piston 12 is slidably arranged in the cylinder 11 to divide the interior of the piston 12 into an A chamber 18A and a B chamber 18B. The outer cylinder 13 is arranged outside the cylinder 11,
One ends of the cylinder 11 and the outer cylinder 13 are closed by a rod guide 19, and the accommodation housing 14 is arranged at the other end of the cylinder 11 and substantially the center of the outer cylinder 13. Further, in the outer cylinder 13, a housing housing 14 shown in FIG.
The free piston 17 is disposed below the
A reservoir chamber 18C is formed near the housing 14. Reference numeral 20 is a gas chamber 20 in which a gas such as nitrogen gas is enclosed.

A piston rod 21 is fixed to the piston 12, and the piston rod 21 has a rod guide 19
It penetrates through and is projected outward.

A first flow path 22 is formed between the cylinder 11 and the outer cylinder 13, and the first flow path 22 is formed by the rod guide 1.
The chamber A is communicated with the A chamber 18A through the second flow path 23 formed in 9. The first housing hole 24 is formed in the housing housing 14.
And the second housing hole 25 is formed, and the third flow path 2 is formed.
6, the fourth flow path 27, the fifth flow path 28, and the sixth flow path 29 are formed respectively. The third flow path 26 connects the first flow path 22 and the first accommodation hole 24. The fourth flow path 27 connects the first accommodation hole 24 and the reservoir chamber 18C. Fifth channel 28
Connects the reservoir chamber 18C and the second accommodation hole 25.
The sixth flow path 29 connects the second accommodation hole 25 and the lower chamber 18B. Therefore, the first flow path 22 passes through the third flow path 26, the first storage hole 24, the fourth flow path 27, the reservoir chamber 18C, the fifth flow path 28, the second storage hole 25, and the sixth flow path 29. B room 1
It is connected to 8B.

Reference numeral 30 is a connecting hole 30 for supporting the hydraulic shock absorber 10 on the axle side of the vehicle, and the tip of the piston rod 21 is supported on the vehicle body side of the vehicle.

Now, the first accommodation hole 24 and the second accommodation hole 25 are formed so as to face each other in the diametrical direction of the cylinder 11.
The compression side damping force adjusting mechanism 15 is provided in the second accommodation hole 25 as a first
The extension side damping force adjusting mechanism 16 is independently and detachably housed in the housing hole 24, and is held in the housing housing 14 by the cap 31. Therefore, the reservoir chamber 18C is
It is formed in the vicinity of the compression side damping force adjusting mechanism 15 and the extension side damping force adjusting mechanism 16.

As shown in FIG. 2, each of the compression side damping force adjusting mechanism 15 and the extension side damping force adjusting mechanism 16 has a valve seat 32, a damping valve 33, a shutter 34, a shutter operating portion 35, a bypass passage 36, and a bypass passage 36. Needle valve 3
7, and these are supported by the support member 38 to form a unit structure.

That is, the shutter operating portion 35 comprises an operating rotary shaft 39 and an operating plate 40, and the operating rotary shaft 39 is rotatably supported by the support member 38 via the click mechanism 41. A hollow support bolt 42 is fitted on the operation rotary shaft 39 so as to be relatively rotatable. A valve seat 32, a damping valve 33 and a shutter 34 are attached to the support bolt 42, a retainer 43, washers 44 and 45.
Through (FIG. 3), the nut 46 is integrally tightened and fixed. The damping valve 33 and the shutter 34 are provided on the surfaces of the valve seat 32 that face each other.

As shown in FIGS. 4, 5 and 6, the valve seat 32 has high oil holes 4 having different flow passage areas in the circumferential direction.
7, middle oil holes 48 and wax oil holes 49 are formed so as to penetrate therethrough, and a plurality of return flow passages 50 are also formed so as to penetrate at the outer peripheral edge side. The high oil hole 47 has the smallest diameter, and the wax oil hole 49 has the largest diameter. Further, a ring-shaped guide groove 51 is formed on the shutter 34 side surface of the valve seat 32.

The damping valve 33 is formed by stacking disc valves, and has a diameter that covers the high oil hole 47, the middle oil hole 48, and the low oil hole 49 of the valve seat 32. A damping force is generated by the flexural deformation of the damping valve 33 by this hydraulic oil.

The shutter 34 is a washer 44 shown in FIG.
And 45 so as to be rotatable with respect to the valve seat 32, and have a window portion 52 as shown in FIG. The window portion 52 reliably selects and opens the high oil hole 47, the middle oil hole 48, or the low oil hole 49 by the rotation of the shutter 34. 7A shows the case where the window 52 opens the high oil hole 47, and FIG. 7B shows the window 5
2 is a case where the middle oil hole 48 is opened.
(C) shows a case where the window portion 52 opens the wax oil hole 49. The hydraulic oil passes through the opened high oil hole 47, middle oil hole 48 or low oil hole 49, and flexibly deforms the damping valve 33.

Further, as shown in FIG.
Is a spring 5 interposed between the operation plate 40 and
3 functions as a check valve that is urged toward the valve seat 32 side to close the return passage 50 of the valve seat 32.

The shutter operating portion 35 is the operation rotary shaft 3
The operation plate 40 is installed on one end of the rotor 9 so as to rotate together, and the operation piece 54 is engaged with the operation plate 40. The other end of the operation rotary shaft 39 extends to the outside of the cap 31. Further, after the tip of the operation piece 54 penetrates the guide hole 61 (FIGS. 1 and 7) of the shutter 34, it is fitted into the guide groove 51 of the valve seat 32. Therefore, the operator
By pinching the other end of the operation rotary shaft 39 and rotating the operation rotary shaft 39, the operation piece 54 rotates the shutter 34 via the operation plate 40.

The operation rotary shaft 39 of the shutter operation section 35.
Has a hollow shape, and this hollow portion constitutes the bypass flow path 36. The bypass passage 36 is a passage provided in parallel with the high oil hole 47, the middle oil hole 48, the low oil hole 49 of the valve seat 32, and the damping valve 33, and the needle valve is provided in the bypass passage 36. 37 is provided. The needle valve 37 is arranged on the other end side of the operation rotary shaft 39, and allows the flow passage area of the bypass flow passage 36 to be changed by the rotation operation of the operator.

Next, the operation will be described with reference to FIGS. 1 and 2. In the compression process of the hydraulic shock absorber 10, the hydraulic oil in the B chamber 18B reaches the compression side damping force adjusting mechanism 15 via the sixth flow path 29 as shown by the solid arrow in FIGS.
At a low speed of 2, a damping force at a low speed on the pressure side is generated in the flow path (orifice) through the bypass flow path 36 and the needle valve 37. Further, when the piston 12 is in the middle and high speeds, the damping valve 33 is flexibly deformed through the high oil hole 47, the middle oil hole 48 or the low oil hole 49 of the valve seat 32 to generate the damping force at the pressure side in the middle and high speeds. The hydraulic oil flowing out from the compression side damping force adjusting mechanism 15 reaches the reservoir chamber 18C via the fifth flow path 28, and reaches the inside of the extension side damping force adjusting mechanism 16 from the fourth flow path 27. In the extension side damping force adjusting mechanism 16, the hydraulic oil flows through the return flow passage 50 of the valve seat 32 to push and open the shutter 34, and from the third flow passage 26 to the first flow passage 22 and the second flow passage 23. After that, it flows to room A 18A.

During the expansion process of the hydraulic shock absorber 10, the chamber A 18
The hydraulic oil in A reaches the inside of the extension side damping force adjusting mechanism 16 through the second flow path 23, the first flow path 22 and the third flow path 26 in this order, as shown by the broken line arrows in FIGS. 1 and 2. , Piston 12
At low speed, the damping force at low speed on the extension side is generated in the flow path (orifice) with the needle valve 37 via the bypass flow path 36. Further, when the piston 12 is in the middle high speed, the damping valve 33 is flexibly deformed through the high oil hole 47, the middle oil hole 48 or the low oil hole 49 of the valve seat 32 to generate the damping force at the extension side middle speed. Extension side damping force adjustment mechanism 1
The hydraulic oil flowing out of 6 reaches the reservoir chamber 18C via the fourth flow path 27, and reaches the inside of the compression side damping force adjusting mechanism 15 from the sixth flow path 29. In the compression side damping force adjusting mechanism 15, the hydraulic oil flows through the return flow passage 50 of the valve seat 32 to push and open the shutter 34, and through the sixth flow passage 29, the B chamber 1
It flows to 8B.

In the compression process or the expansion process of the hydraulic shock absorber 10, the needle valve 37 of the compression side damping force adjusting mechanism 15 or the expansion side damping force adjusting mechanism 16 is rotationally adjusted, so that the flow passage area of the valve flow passage 36, that is, The flow passage area constituted by the bypass flow passage 36 and the needle valve 37 can be changed, and the damping force at low speed on the compression side or the extension side can be adjusted.

During the compression process or the expansion process of the hydraulic shock absorber 10, the shutter 34 is moved to the valve seat 32 by rotationally adjusting the operating rotary shaft 39 of the shutter operating portion 35.
The high oil hole 47, the middle oil hole 48, or the low oil hole 49 is selected, and the pressure receiving area of the damping valve 33 is changed to adjust the damping force at the compression side or the extension side at high speed. The damping force is large when the shutter 34 selects the high oil hole 47, medium when the shutter 34 selects the middle oil hole 48, and medium when the shutter 34 selects the low oil hole 49. Has a small damping force and is set respectively.

As described above, the damping force of the hydraulic shock absorber 10 is adjusted, and as a result, the damping force characteristic shown in FIG. 8 is obtained. Solid lines 55, 56 and 57 in FIG. 8 are hydraulic shock absorbers 10.
Is a damping force characteristic in the compression process, and solid lines 58, 59 and 60 are damping force characteristics in the expansion process of the hydraulic shock absorber 10. The solid lines 55 and 58 indicate that the shutter 34 has a high oil hole 47.
Shows the case where the damping force selected is large and the solid lines 56 and 5
9 indicates the case where the shutter 34 selects the middle oil hole 48 for a medium damping force, and the solid lines 57 and 60 indicate the case where the shutter 34 selects the wax oil hole 49 for a small damping force.

According to the above-described embodiment, since the compression side damping force adjusting mechanism 15 and the extension side damping force adjusting mechanism 16 are independently arranged in the second accommodation hole 25 and the first accommodation hole 24, respectively, the compression side damping force is reduced. The force and the extension side damping force can be set completely independently.

Further, since the compression side damping force adjusting mechanism 15 and the extension side damping force adjusting mechanism 16 are arranged to face each other in the diametrical direction of the cylinder 11, these both damping force adjusting mechanisms are arranged in the diametrical direction of the cylinder. Compared to the conventional case where
The diameters of the damping valve 33 and the valve seat 32 arranged in the respective damping force adjusting mechanisms 15 and 16 can be increased, and the oil holes 47, 48 and 49 formed in the valve seat 32 are provided.
The flow passage area of can also be set large. Therefore, the variable width of the damping force characteristics of the respective damping force adjusting mechanisms 15 and 16 can be set large as shown in FIG.
0 can be configured compactly.

Further, since the reservoir chamber 18C is installed in the vicinity of the compression side damping force adjusting mechanism 15 and the extension side damping force adjusting mechanism 16, the flow path (that connects the reservoir chamber 18C and both damping force adjusting mechanisms 15 and 16) Fourth channel 27 and fifth channel 2
8) does not become complicated, and the influence of transmission delay of hydraulic pressure can be avoided.

Further, the valve seat 3 constituting each of the compression side damping force adjusting mechanism 15 and the extension side damping force adjusting mechanism 16.
2, attenuation valve 33, shutter 34, shutter operation unit 3
5, the bypass passage 36 and the needle valve 37 have a detachable unit structure, the damping force adjusting mechanisms 15 and 16 can be easily replaced, and the maintainability can be improved.

Further, since the compression side damping force adjusting mechanism 15 and the expansion side damping force adjusting mechanism 16 are installed in the housing housing 14 so as to be opposed to each other in the diameter direction of the cylinder 11,
The compression-side damping force adjusting mechanism 15 and the extension-side damping force adjusting mechanism 16 are not projected outward in the diametrical direction of the cylinder 11, and the hydraulic shock absorber 10 can be made compact in this respect as well.

Further, since no valve mechanism is installed in the piston 12, another damping force adjusting mechanism (for example, a position-dependent damping force adjusting mechanism) can be installed in the piston 12.

[0038]

As described above, according to the hydraulic shock absorber of the present invention, the variable width of the damping force characteristic can be set to be large, and the damping force adjusting mechanism can be easily attached and detached to improve the workability of maintenance. be able to.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a hydraulic shock absorber according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing a part of FIG. 1 in an enlarged manner.

FIG. 3 is an enlarged cross-sectional view of a III part in FIG.

FIG. 4 is a cross-sectional view of the valve seat of FIG. 2 taken along the line IV-IV in FIGS. 5 and 6.

5 is a view on arrow V in FIG. 4. FIG.

FIG. 6 is a view on arrow VI of FIG. 4.

FIG. 7 is an operation diagram showing an operation state of the shutter of FIG.

FIG. 8 is a graph showing damping force characteristics of the hydraulic shock absorber of FIG.

[Explanation of symbols]

 10 Hydraulic shock absorber 11 Cylinder 12 Piston 13 Outer cylinder 14 Housing housing 15 Pressure side damping force adjusting mechanism 15 Extension side damping force adjusting mechanism 18A A chamber 18B B chamber 18C Reservoir chamber 22 First flow path 23 Second flow path 26 Third flow Channel 27 Fourth channel 28 Fifth channel 29 Sixth channel 32 Valve seat 33 Damping valve 34 Shutter 35 Shutter operation part 36 Bypass channel 37 Needle valve 47 High oil hole 48 Middle oil hole 49 Low oil hole 52 Window part

Claims (3)

[Claims] 1. A piston is installed in a cylinder filled with hydraulic oil to define the inside of the cylinder, and these defining chambers are communicated with each other by a flow path formed outside the cylinder. A hydraulic shock absorber in which a compression side damping force adjusting mechanism for generating and adjusting a compression side damping force and an extension side damping force adjusting mechanism for generating and adjusting an extension side damping force are provided in a road, A hydraulic shock absorber, wherein a side damping force adjusting mechanism is arranged in a housing housing installed in the cylinder so as to be opposed to each other independently of the diametrical direction of the cylinder. 2. The hydraulic shock absorber according to claim 1, wherein the storage housing has a reservoir chamber formed in the vicinity of the compression side damping force adjusting mechanism and the extension side damping force adjusting mechanism. 3. The compression side damping force adjusting mechanism and the extension side damping force adjusting mechanism are mounted on one surface of a valve seat in which a plurality of oil holes having different flow passage areas are formed in the circumferential direction, respectively. Damping valve that can close the oil hole, a shutter that is rotatably installed on the other surface of the valve seat and that has a window that selectively opens the oil hole, the valve seat, and the damping valve. And a shutter operating portion that extends through the central portion of the shutter to the outside and that rotationally operates the shutter by an operation from the outside, and a bypass flow path formed by bypassing the attenuation valve in the shutter operating portion. When,
And a needle valve that is installed in the bypass flow passage and that can change the flow passage area of the bypass flow passage by an operation from the outside, the valve seat, the damping valve, the shutter, and the shutter operation unit. The hydraulic shock absorber according to claim 1 or 2, wherein the bypass flow path and the needle valve are configured as a unit structure and are detachably arranged in a housing.