JPS588842A - Shock absorber - Google Patents

Abstract

PURPOSE:To prevent both tubes from bumping each other, by designing a closed space serving as two hydraulic pressure lock chambers so as to form two steps to the progress of a compression stroke between an inner tube and an outer tube at their compression stroke finish end side. CONSTITUTION:In time of an extension stroke, since oil in an oil reservoir 36 flows into a room 38 via a hollow part of a hollow rod 33 and a path hole 37A while oil in a pressure room 39 is discharged to the oil reservoir 36 side via a throttle hole 41, damping force is energized. Next, in time of a compression stroke, oil in the room 38 flows into the pressure room 39 via an interpenetrating hole 40A and a check valve 40 while the excess oil is led to the oil reservoir 36 from the path hole 37 to the hollow rod 33. When arriving at the finish end of the compression stroke, a small diameter parts 31B of an inner tube 31 is inserted into a small diamter part 32B of an outer tube 32 so that compression resistivity is somewhat increased. Afterward, when the interpenetrating hole 40A is blocked off with the said smaller diameter part 32B, compression comes into a maximum state and collision between tubes 31 and 32 is thus obviated.

Description

[Detailed description of the invention] The present invention relates to a shock absorber.

Figure 1 shows a shock absorber 1 used in general motorcycles.
2, the shock absorber 1 is composed of an inner tube 2 and an outer tube 3 that are mutually expandable and retractable, and is interposed between a frame 4 and a front wheel 5 of a vehicle body. Buffer 1
The spring cushions vibrations caused by uneven road surfaces, and the vertical vibrations of the spring can be suppressed and damped by oil flow resistance.

2 and 3 are cross-sectional views showing the internal structure of a conventional shock absorber, in which the inner tube 11 is slidably inserted into the outer tube 12, and the inner tube 11 is slidably inserted into the outer tube 12.
A hollow rod 13 vertically provided at the inner bottom passes through the end surface 11A of the inner tube 11 and is loosely inserted into the inner tube 11. An auxiliary piston 14 is formed at the tip of the hollow rod 13, and a spring 15 is interposed between the other end surface of the inner tube 11 and the auxiliary piston 14. contains oil. Pressure chamber 1 defined by inner tube 11, hollow rod 13 and auxiliary piston 14
7 is communicated with the oil reservoir chamber 16 through a throttle hole 18, and is capable of generating a damping force during an extension stroke in which the inner tube 11 and outer tube 12 of this shock absorber mutually extend.

Inner tube 11 of such a conventional shock absorber
During the compression stroke in which the outer tube 12 and the outer tube 12 mutually contract, oil filling the chamber 19 flows into the pressure chamber 17 via the check valve 20, and excess oil flows from the through hole 21 to the hollow opening. The oil is led to the oil reservoir chamber 16 through the hollow part 23. As the compression stroke further progresses, the inner tube 11
The outer tube 12 and the lock taper 23 with the lock tube 22 form a hydraulic lock chamber 24 as shown in FIG.
By trapping oil in the seventh chamber 24, the compressive resistance force generated between the inner tube 11 and the outer tube 12 is rapidly increased, and the occurrence of impact due to the bottom between the inner tube 11 and the outer tube 12 is prevented. are doing.

However, in such a conventional shock absorber, as the compression stroke progresses, a large compression resistance force suddenly occurs at the end of the compression stroke, and such a shock absorber is applied to, for example, a vehicle. In this case, there is a problem that a good riding feeling cannot be ensured.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a shock absorber that can smoothly alleviate the impact on the bottoms of the inner tube and the outer tube.

In order to achieve the above object, the present invention includes an inner tube that is slidably inserted into an outer tube, and a pressure chamber that generates a damping force during an extension stroke between the inner tube and the outer tube. In the shock absorber formed between the inner tube and the outer tube at the end end of the compression stroke, a sealed space consisting of a first hydraulic lock chamber and a second hydraulic lock chamber is provided between the inner tube and the outer tube at the end of the compression stroke. It can be formed in two stages as the process progresses.

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

4 to 6 are cross-sectional views showing different operating states of a shock absorber as an embodiment of the present invention. The inner tube 31 has a sliding contact portion 3 inside the outer tube 32.
1A and sliding contact portion 32A. The outer periphery of the tip side of the inner tube 31 is a small outer diameter portion 31
B, the inner periphery of the bottom side of the outer tube 32 is a small inner diameter part 32B, and the small outer diameter part 31B can be fitted into the small inner diameter part 32B.

A hollow rod 33 that is vertically installed at the inner bottom of the outer tube 32 passes through the distal end surface of the inner tube 31 and is loosely inserted into the inner tube 31, and an auxiliary piston 34 is disposed at the distal end of the hollow rod 33. ing. A spring 35 is compressably interposed between the inner tube 31 and the auxiliary piston 34, and an oil reservoir chamber 36 within the inner tube 31 is filled with oil at a predetermined level. The oil in the oil reservoir chamber 36 flows through the hollow part of the hollow rod 33 and the through hole 37 to the tip of the inner tube 31, the outer tube 32, and the hollow rod 3.
It is possible to flow into a chamber 38 defined by 3 and 3. A check valve 40 is provided in the pressure chamber 39 defined by the inner tube 31, the hollow rod 33, and the auxiliary piston 34 during the compression stroke when the inner tube 31 and outer tube 32 of this shock absorber mutually contract. Oil is introduced from the chamber 38 through the communication hole 40A, and the oil introduced into the pressure chamber 39 is introduced through the throttle hole 41 during an extension stroke in which the inner tube 31 and the outer tube 32 of this shock absorber mutually extend. It is discharged to the oil sump chamber 36 side, making it possible to generate damping force during the extension stroke. Note that the communication hole 40A is connected to the inner tube 31.
Small outer diameter portion 31B (this is open).

Further, between the inner tube 31 and the outer tube 32, there is a first tube shown in FIG. 5 on the end side of the compression stroke.
Hydraulic lock chamber 42. A sealed space, which is a second hydraulic lock chamber 43 shown in FIG. 6, can be formed in two stages as the compression stroke progresses. That is, in the state shown in FIG. 5 in which the compression stroke progresses and the small outer diameter portion 31B of the inner tube 31 fits into the small inner diameter portion 32B of the outer tube 32, the distal end surface of the inner tube 31 and the outer tube A first hydraulic lock chamber 42 is formed between the bottom of the
When the compression stroke further progresses to a recompressed state, the communication hole 4
0A is closed by the small inner diameter portion 32B of the outer tube 32, and a second hydraulic rotor chamber 43 is formed between the small outer diameter portion 31B of the inner tube 31 and the sliding contact portion 32A of the outer tube 32. .

Next, the operation of the above embodiment will be explained. During the extension stroke of the shock absorber, the oil in the oil reservoir chamber 36 flows into the chamber 38 through the hole 37 in the hollow portion 9 of the hollow rod 33, and during the extension stroke, the check valve 40 is closed. Therefore, the oil in the pressure chamber 39 is discharged to the oil reservoir chamber 36 side through the throttle hole 41, and generates a damping force during expansion. During the compression stroke of the shock absorber, oil in the chamber 38 flows into the pressure chamber 39 via the communication hole 40A and the check valve 40, and excess oil flows from the communication hole 37 through the hollow part of the hollow rod 33. and is guided to the oil sump chamber 36. As the compression stroke progresses and approaches its end, the small outer diameter portion 31B of the inner tube 31 is connected to the outer tube 3, as shown in FIG.
2, and forms a first hydraulic lock chamber 42 between the inner tube 31 and the outer tube 32 to reduce the compression resistance force generated between the inner tube 31 and the outer tube 32. ＼Increase. In addition, at the stage where the first hydraulic lock chamber 42 is formed, the small outer diameter portion 31B of the inner tube 31 and the outer tube 3
The oil surrounded by the sliding contact portion 32A of 2 is the communication hole 40A.
, can flow into the pressure chamber 39 side via the check valve 40. As the compression process progresses further and reaches the most compressed state,
As shown in FIG. 6, the communication hole 40A is connected to the outer tube 3.
A second hydraulic lock chamber 4 is closed between the inner tube 31 and the outer tube 32.
3 is formed, an inner tube 31 and an outer tube 3
2, the impact caused by the bottom portion of the inner tube 31 colliding with the bottom portion of the outer tube 32 is alleviated.

According to the embodiment described above, a certain amount of impact during the compression stroke can be alleviated by the first hydraulic lock chamber 42, and even larger impacts can be alleviated by the first hydraulic lock chamber 42 and the second hydraulic lock chamber 43. Since the hydraulic lock chamber is formed in two stages, it is possible to smoothly absorb the impact by the bottoms of the inner tube 31 and the outer tube 32.

As described above, the present invention allows the inner tube to be slidably inserted into the outer tube, and the pressure chambers that generate damping force during the extension stroke of the inner tube and the outer tube to be separated from each other on the inner tube side and the outer tube side. In the shock absorber formed between the inner tube and the outer tube, a sealed space consisting of a first hydraulic lock chamber and a second hydraulic lock chamber is provided between the inner tube and the outer tube at the end of the compression stroke. On the other hand, since it can be formed in two stages, it has the effect that the impact on the bottoms of the inner tube and the outer tube can be smoothly alleviated.

[Brief explanation of the drawing]

Fig. 1 is a partial side view showing a shock absorber used in general motorcycles, Fig. 2 is a sectional view showing the internal structure of a conventional shock absorber, and Fig. 3 is the same as that of Fig. 2. 4 is a sectional view showing the internal structure of the shock absorber according to the present invention, and FIGS. 5 and 6 are sectional views showing different operating states of FIG. 4. 31-inner tube, 32 outer tube. 39 - Pressure chamber, 42 First hydraulic rotor chamber. 43-Second hydraulic lock chamber. Agent Patent Attorney Shuji Shiokawa/Zuwei 6

Claims (1)

[Claims] (11) A shock absorber in which the inner tube is slidably inserted into the outer tube, and a pressure chamber is formed between the inner tube side and the outer tube side to generate a damping force during the extension stroke of the inner tube and outer tube. In this step, a sealed space consisting of a first hydraulic lock chamber and a second hydraulic lock chamber is formed between the inner tube and the outer tube at the end end of the compression stroke in two stages as the compression stroke progresses. A shock absorber characterized by enabling.