JPH0667943U - Hydraulic shock absorber - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a hydraulic shock absorber which can obtain a desired soft feeling, can widen the effective adjustment range of damping force, and can perform fine adjustment. [Composition] An inner tube 1 is movably inserted into an outer tube, a damper cylinder 2 is erected from a lower portion of the inner tube, and a piston rod is movably inserted through a piston into the damper cylinder. In conjunction with the tube, the reservoir 3 is partitioned between the inner tube and the damper cylinder,
In the hydraulic shock absorber in which the piston partitions the rod side chamber and the piston side chamber 4 in the damper cylinder, and the compression side damping force generating mechanism A is provided in the lower part of the damper cylinder, the compression side damping force generating mechanism connects the piston side chamber and the reservoir. Main passages 7, 33, 34 and bypass passages 9, 24 are provided, main leaf valves 8, 31 are provided in the middle of the main passage so as to be openable and closable, and the sub-leaf valve 1 is provided in the bypass passage.
2, 30 and the variable orifices 14, 28 are provided in parallel.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hydraulic shock absorber suitable for use with a front fork or a Liya cushion unit that is interposed between a motorcycle body and an axle and that damps vibrations from the road surface.

[0002]

[Prior art]

 As this type of hydraulic shock absorber, for example, the one shown in FIG. 3 has been developed.

This is because the inner tube 1 is movably inserted into the outer tube, the damper cylinder 2 is erected from the lower part of the inner tube 1, and the piston rod is movably inserted into the damper cylinder 2 via a piston. Inserted, the piston rod connects to the top of the outer tube.

A reservoir 3 is defined between the inner tube 1 and the damper cylinder 2, and a rod side chamber and a piston side chamber 4 are defined in the damper cylinder 2 via a piston.

A compression side damping force generating mechanism is provided below the damper cylinder 2 between the piston side chamber 4 and the reservoir 3.

The compression-side damping force generating mechanism A includes a hollow rod 5, a partition wall member 6 provided on the outer periphery of the hollow rod 5, and a compression side main passage provided in the partition wall member 6 for communicating the piston side chamber 4 with the reservoir 3. 7, a pressure side main leaf valve 8 that is openably and closably provided at the outlet end of the main passage 7, a series of bypasses 9 and 10 that are provided in the hollow rod 5 and that connect the piston side chamber 4 and the reservoir 3 to each other, and the bypass 9 A needle valve 11 for setting a variable orifice and a sub-leaf valve 12 which is provided at the outlet end of the bypass 10 so as to be openable and closable are provided.

According to the compression side damping force generating mechanism A, the oil in the piston side chamber 4 passes through the bypasses 9 and 10 during compression in the low speed range, and the variable orifice and the sub leaf set in the needle valve 11 provided in parallel are set. A synthetic damping force is generated by the valve 12, and it becomes possible to generate a synthetic damping force by opening the main leaf valve 8 from the main passage 7 at medium and high speeds.

[0008]

[Problems to be solved by the device]

 In the conventional hydraulic shock absorber described above, it is possible to generate a damping force to obtain a desired feeling by adjusting the variable orifice depending on the course conditions on which the motorcycle runs and the rider's skill.

However, since the variable orifice and the pressure side leaf valve 12 are arranged in series, a damping force is generated by the pressure side leaf valve 12 even when the variable orifice is fully opened.

Therefore, there is a problem that this damping force gives a hard and bad feeling to a high-speed traveling on a hard road surface or to a rider having a relatively low skill.

Therefore, an object of the present invention is to provide a hydraulic shock absorber capable of obtaining a desired soft feeling, expanding the effective adjustment range of the damping force, and capable of fine adjustment.

[0012]

[Means for Solving the Problems]

 In order to achieve the above object, the structure of the present invention is such that the inner tube is movably inserted in the outer tube, the damper cylinder stands up from the lower part of the inner tube, and the piston rod moves through the piston in the damper cylinder. It is freely inserted, the piston rod interlocks with the outer tube, the reservoir is defined between the inner tube and the damper cylinder, and the piston divides the rod side chamber and the piston side chamber into the damper cylinder. In a hydraulic shock absorber that has a compression-side damping force generation mechanism in the lower part of the, the compression-side damping force generation mechanism has a main passage that connects the piston side chamber and the reservoir and a bypass passage, and a main leaf valve is provided in the middle of the main passage. It is openable and closable and has a sub-leaf valve and variable orifice in the bypass passage. It is characterized in that provided in the column.

[0013]

[Action]

 During compression, in the low speed region, the oil in the piston side chamber flows from the bypass to the reservoir via the variable orifice and pressure side sub-leaf valve, and damping force is generated by the variable orifice and pressure side sub-leaf valve.

At medium and high speeds, it flows from the main passage to the reservoir via the main leaf valve, and a synthetic damping force including the main leaf valve is generated.

The damping force is adjusted by adjusting the opening amount of the variable orifice.

When the variable orifice is fully opened, a soft low damping force that is not affected by the sub-leaf valve is obtained.

[0017]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. The basic structure of this hydraulic shock absorber is the same as that of the prior art shown in FIG.

That is, the inner tube 1 on the axle side is slidably inserted into the outer tube on the vehicle body side.

A damper cylinder 2 is erected in the lower center of the lower bottom member 10 of the inner tube 1, and a piston rod is movably inserted into the damper cylinder 2 via a piston. The piston rod is interlocked with the outer tube. There is.

The piston defines a rod side chamber and a piston side chamber 4 in the damper cylinder 2.

A reservoir 3 including a lower oil chamber 11 and an upper gas chamber is defined between the inner tube 1 and the damper cylinder 2.

The piston side chamber 4 and the reservoir 3 are in communication with a compression side damping force generating mechanism A provided in the lower portion of the damper cylinder 2 via a port 13.

The compression side damping force generating mechanism A includes a hollow rod 5 coupled to the bottom member 10 and a lower portion of the damper cylinder 2, a partition member 6 provided on the outer periphery of the hollow rod 5, and a piston side chamber provided on the partition member 6. 4 and the reservoir 3 to communicate with each other, the pressure side main leaf valve 8 provided at the outlet end of the main passage 7 so as to be openable and closable, and the hollow rod 5 to communicate with the piston side chamber 4 and the reservoir 3. It is composed of a bypass 9, a variable orifice 14 and a pressure side sub-leaf valve 12 which are provided in parallel in the middle of the bypass 9.

The hollow rod 5 includes a large-diameter base end portion 5 a and a cylindrical portion 5 b, and the base end portion 5 a is connected to the bottom member 10 and the hollow cylinder 2 via a seal 15 and a screw 16. There is.

A vertical passage 9a forming a part of the bypass 9 is formed in the cylindrical portion 5b, and two branched parallel lateral passages 9b, 9 forming a part of the bypass 9 are formed in the base end portion 5a. c is formed.

A pressure side sub-leaf valve 12 is provided at the outlet end of the lateral passage 9b so as to be openable and closable, and a needle valve 11 is vertically inserted in the middle of the other lateral passage 9c and formed in the middle of the lateral passage 9c. The opening area of the variable orifice 14 is adjusted by the needle valve 11.

The needle valve 11 is rotatably coupled to the base end portion 5 a via a screw 16, and is guided in the vertical direction via a guide groove 17 and a guide ball 19, and a tool is inserted into the groove 18 from the outside. When it rotates, it moves up and down, and the variable orifice 14 is adjusted from fully open to fully closed depending on its position.

A pressure side main passage 7 and an extension side passage 20 are formed in the partition wall member 6, and a pressure side main leaf valve 8 is openably and closably provided at a lower outlet of the pressure side main passage 7 to form an upper outlet of the extension side passage. A check valve 21 is provided to be openable and closable.

During the extension operation, the oil in the reservoir 3 is supplied from the extension side passage 20 to the piston side chamber 4 via the check valve 21.

During the compression operation, in the low speed range, the oil in the piston side chamber 4 flows from the bypass 9 to the reservoir 3 via the variable orifice 14 and the pressure side sub-leaf valve 12, and the variable orifice 14 and the sub-leaf valve 12 are combined. In the middle / high speed range, oil also flows out from the main passage 7 through the main leaf valve 8 to generate a combined damping force by adding the damping force of the main leaf valve 8.

Since the pressure side sub-leaf valve 14 and the variable orifice 14 are arranged in parallel in the bypass 9, when the variable orifice 14 is fully closed, the damping force of only the sub-leaf valve 12 is generated and the variable orifice 14 is changed. When the orifice 14 is open, a synthetic damping force corresponding to the opening is generated.

Moreover, when the variable orifice 14 is fully opened, the soft low damping force of only the variable orifice 14 is generated in the extremely low speed range.

FIG. 2 shows another embodiment of the present invention in which the base end 22a of the hollow rod 22 is fitted in the body 21 and the partition member 23 is provided on the outer periphery of the cylindrical portion 22b. .

The hollow rod 22 is formed with horizontal passages 26, 27 parallel to the vertical passage 25 constituting the bypass 24, and a pressure side sub-leaf valve 30 is provided at the outlet end of the horizontal passage 26 for opening and closing. A variable orifice 28 controlled by the needle valve 26 is provided in the middle of the other lateral passage 26.

The partition wall member 23 is formed with main passages 33 and 34 that also serve as pressure side and extension side passages, and the main side passages of these main passages 33 and 34 are checked with the pressure side main leaf valve 31 biased by a spring 35. A valve 32 is provided so as to be superposed and openable.

In the low speed range during compression, the oil in the piston side chamber 4 flows from the bypass 24 through the variable orifice 28 and the pressure side sub-leaf valve 30 to the reservoir 3, and a combined damping force is generated by the variable orifice 28 and the sub-leaf valve 30. In the middle and high speed ranges, the main leaf valves 31 also flow from the main passages 33 and 34, and a synthetic damping force is generated by adding the damping force of the main leaf valves 31.

At the time of extension, the oil in the reservoir 3 pushes open the check valve 32 and is rarely required from the main passages 33, 34 to the piston side 4.

The needle valve 26 is vertically driven by a push rod 36, and the push rod 36 is screwed into the body 21 via a screw 37 and guided by a guide ball 38 while rotating in the vertical direction.

Other operations are the same as those of the embodiment shown in FIG.

[0041]

[Effect of device]

 The present invention has the following effects.

1) Since the bypass is provided with the variable orifice and the sub-leaf valve in parallel, a synthetic damping force of the variable orifice and the pressure-side leaf valve is generated in the pressure-side low speed range, and the main leaf is operated in the middle and high speeds. A synthetic damping force is generated with the damping force of the valve added. At this time, the damping force can be adjusted by the opening area of the variable orifice, the effective adjustment width can be expanded as compared with the prior art, and fine adjustment can be performed.

2) When the variable orifice is fully closed, a synthetic damping force is generated by the sub-leaf valve and the main leaf valve, and at this time, a high damping force is obtained by the sub-leaf valve even in an extremely low speed range.

3) A desired soft feeling is obtained as the variable orifice is opened. Especially, when the variable orifice is fully opened, the sub-leaf valve is not affected in the extremely low speed range, and the soft low damping force from the fully opened variable orifice is obtained. Is obtained. For this reason, it is possible to give a soft feeling to a rider who runs at a high speed on a hard road or to a rider who has a relatively low skill.

[Brief description of drawings]

FIG. 1 is a partially longitudinal front view of a hydraulic shock absorber according to an embodiment of the present invention.

FIG. 2 is a sectional view of an essential part of a hydraulic shock absorber according to another embodiment of the present invention.

FIG. 3 is a partially longitudinal front view of a conventional hydraulic shock absorber.

[Explanation of symbols]

 1 Inner tube 2 Damper cylinder 3 Reservoir 4 Piston side chamber 7,33,34 Main passage 8,31 Main leaf valve 9,24 Bypass passage 12,30 Sub leaf valve 14,28 Variable orifice A Pressure side damping force generation mechanism

Claims (1)

[Scope of utility model registration request] 1. An inner tube is movably inserted into an outer tube, a damper cylinder is erected from a lower portion of the inner tube, a piston rod is movably inserted into the damper cylinder through a piston, and the piston rod is an outer tube. In conjunction with the tube, a reservoir is defined between the inner tube and the damper cylinder, the piston divides the rod side chamber and the piston side chamber inside the damper cylinder, and the compression side damping force generation mechanism is provided below the damper cylinder. In the shock absorber, the compression-side damping force generation mechanism includes a main passage that connects the piston side chamber and the reservoir, and a bypass passage. A main leaf valve is provided in the middle of the main passage so that the main leaf valve can be opened and closed. Hydraulic buffer characterized by having orifices in parallel vessel.