JPH04236831A - Shock absorber for vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a shock absorber for a vehicle.
More specifically, the present invention relates to a shock absorbing device for a vehicle that is effective in removing minute vibrations transmitted from the road surface and improving ride comfort without sacrificing the handling stability of the vehicle.

0002

[Prior Art and Problems] Conventionally, a damper 100 used in a double wishbone type shock absorber is connected to a wheel side (lower side) 10 and a vehicle body via an elastic member 20 such as a rubber bush, as shown in FIG. 5, which is a sectional view of a conventional example. It was connected between the side (upper side) 1.

[0003] The elastic member 20 such as a rubber bush plays the role of absorbing minute vibrations transmitted from the road surface to the axle in the first stage, but if the spring constant is too small, the stiffness of the entire suspension decreases and the steering stability is affected. tends to be damaged. Therefore, there was a problem in that it was difficult to achieve both soft ride comfort and maneuverability.

[0004] In particular, when determining the spring constant of elastic members such as rubber bushings for running wheels (mainly front wheels) at the design stage, designers have had to struggle with this trade-off.

As a means to solve this problem, a double wishbon type suspension device has been proposed in which the upper arm support portion (pivotal portion) is connected to the vehicle body via an elastic body (Utility Model No. 64). -9803).

However, the above-mentioned problems have not been completely solved.

That is, it is not an easy problem to constantly maintain the geometry of each axle to provide appropriate compliance. When we investigated the cause of this problem, we found that conventional shock absorbers handle (static) load and displacement (strain).
It was found that the relationship between the two is linear as shown in FIG. FIG. 4 is a graph showing the load-displacement relationship of a conventional vehicle shock absorber.

[0008] Therefore, the inventor of the present invention has pursued a means for improving the ability to absorb micro vibrations at least in the direction of deflection of the spring, and as a result, has arrived at the present invention.

[0009]

[Object of the Invention] An object of the present invention is to improve ride comfort without causing deterioration of steering stability.

Another object of the present invention is to suppress the roll angle without sacrificing ride comfort.

[0011]

SUMMARY OF THE INVENTION According to the present invention, a shock absorber for a vehicle includes a damper that connects a vehicle body side and a wheel side of a vehicle via an elastic member, and a spring disposed in parallel with the damper. A damper for a vehicle, characterized in that the damper is equipped in series with an auxiliary damper having a spring constant lower than that of the auxiliary damper (claim 1). A mold spring (claim 2) is provided.

The present invention will be explained in detail below using examples.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view showing essential parts of an embodiment of the present invention, and FIG. 2 is a front sectional view of the embodiment of the present invention.

In FIG. 2, 1 is a cross member on the vehicle body side;
2 is an upper arm, 2A is an upper arm pivot shaft, 3 is an upper ball joint, 6 is a lower arm, 6A is a lower arm pivot shaft, 7 is a lower ball joint, 9 is a coil spring, 30 is a cylindrical oil damper, 40 is a damper 30 an auxiliary shock absorbing mechanism arranged in series with 11, a damper lower pivot joint;
2 is a damper upper fixing portion, and 12A is a rubber bush (elastic member). Instead of the coil spring 9, the arm pivot shaft 2A or 6A may be supported by a torsion bar, or an air suspension may be used.

Further, the damper 30 may be turned upside down and supported at the lower pivot portion via a rubber bush.

Rather, FIG. 1 is a sectional view of the main part in this case.

In FIG. 1, the embodiment 200 of the present invention differs from the conventional example 100 in that it has an auxiliary buffer mechanism 40 arranged in series.

The auxiliary shock absorbing mechanism 40 consists of a cylinder 40A, a piston 43, rubber cushions 42 and 44 that soften the shock during vertical bottoming, and a connecting rod 45 connected to the wheel side 10 from the piston 43 via a rubber bush 20. ing.

What is important here is that the spring constant K1 of the spring 41 of the auxiliary buffer mechanism 40 is the spring constant K1 of the rubber bush.
2, that is, K1<K2.

As a result, after the auxiliary shock absorbing mechanism 40 has used up its stroke and bottomed, the original damper 30
works.

When a static load is applied to the suspension according to the embodiment, a nonlinear line graph consisting of regions A and B becomes as shown in FIG. This is because, as described above, the coil spring 41 in the auxiliary buffer mechanism 40 first bends together with the external spring 9 in the A area, and then the rubber bush 20 and the original damper 30 contract together with the external spring 9 in the B area. .

[0022] Therefore, when a normal vibration load is repeated, in which small-amplitude short-period vibrations are superimposed on large-width vibrations,
The device of the present invention can absorb minute vibrations at any position.

It should be noted that the present invention is difficult to apply to a MacPherson strut type suspension in which the entire load is received by a damper, but is effective in a type of suspension having parallel springs such as a wishbone type suspension.

Further, the auxiliary shock absorbing mechanism of the present invention may be constructed simply of a small coil spring and a rubber cushion as in this embodiment, but it may also be provided with an orifice in the piston as in the oleo type, and an oil damper function may be added as it is filled with oil. You may. By doing so, convergence characteristics can be provided even in the micro-vibration region in terms of dynamic characteristics, which has the advantage of increasing the degree of freedom in design.

[0025]

[Effects of the Invention] By carrying out the present invention, all of the above objects can be achieved.

[0026] That is, without causing deterioration of steering stability,
Riding comfort can be improved. It also absorbs slight vibrations and suppresses the roll angle without sacrificing ride comfort, improving the driver's sense of security.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an embodiment of the present invention.

FIG. 2 is a partially sectional front view of an embodiment of the present invention.

FIG. 3 is a graph showing a load-displacement relationship in an example of the present invention.

FIG. 4 is a graph showing a load-displacement relationship in a conventional example.

FIG. 5 is a sectional view of a main part of a conventional example.

[Explanation of symbols]

1 Vehicle side 10 Wheel side 20 Rubber bush (elastic member) 30
Damper 40 Auxiliary shock absorber 41 Coil spring 42 Rubber cushion 44 Rubber cushion 43 Piston

Claims (2)

[Claims] 1. A shock absorber for a vehicle comprising a damper that connects a vehicle body side and a wheel side of the vehicle via an elastic member, and a spring disposed in parallel with the damper, wherein the damper has a spring constant higher than that of the elastic member. A shock absorber for a vehicle, characterized in that the damper is a damper equipped with an auxiliary shock absorber mechanism having a low coefficient of shock in series. 2. The shock absorber for a vehicle according to claim 1, wherein the spring in the auxiliary shock absorber is a nonlinear strain spring.