JPH0292711A - Suspension device for vehicle - Google Patents

Abstract

PURPOSE:To give a good ride by directly detecting the vertical movement of wheels according to a road surface condition as the rearwardly changing quantity of a trailing link and carrying out highly accurate control while varying the damping force of a shock absorber in accordance with the road surface condition. CONSTITUTION:A suspension device consists of two suspension arms 4, 5 which are supported by a vehicle body 3 while the other ends thereof being supported by a wheel supporting body 2 for supporting a wheel 1, a strut 8 consisting of a shock absorber 6 which is fixed to the wheel supporting body 2 with the upper portion thereof being supported by the vehicle body and a coil spring 7, and a trailing link 9 the rear end of which is supported by the strut 8 while the front end thereof being supported by the vehicle body 3. In this case, a means 10 detects the displacement in the longitudinal direction of the trailing link 9. A means for varying a damping force which is installed inside the shock absorber 6 is driven in accordance with the detected result of the means 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a suspension system for a vehicle that improves steering response and stability by controlling the damping force of a shock absorber. Conventional technology] Conventionally, as a device for automatically controlling the damping force of a shock absorber used in a vehicle suspension device,
A shock absorber that changes the damping force of a shock absorber based on a signal from a vehicle speed sensor that outputs a signal corresponding to the vehicle speed is known (see Japanese Utility Model Publication No. 58-45129).

[Problem to be solved by the invention]

However, conventional devices change the damping force of the shock absorber through electrical control based on the vehicle speed signal from the vehicle speed sensor, thereby increasing wet longitudinal response as neutral or slightly oversteer characteristics when the vehicle speed is low. When the vehicle speed is high, it attempts to improve stability as an understeer characteristic, and it attempts to estimate the behavior of the vehicle depending on the vehicle speed and control it in advance based on that estimate.It is based on the current state of the vehicle. Well then (,
In particular, no consideration was given to the condition of the driving road surface.
There is a problem in that the damping force of the shock absorber is large even on a road surface with continuous unevenness, and the ride comfort becomes poor because the shock absorber tries to move up and down in response to each unevenness.

Therefore, devices that change the damping force of the shock absorber by detecting the condition of the road surface using a laser or the like are proposed, but devices that use a laser or the like have the problem that the equipment is very expensive and large-scale. Ta.

The present invention solves the above problems, improves riding comfort by reducing the damping force of the shock absorber on continuously uneven road surfaces, and directly detects the current vehicle condition to provide high-precision shock absorber damping. The purpose is to control force.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a suspension system for a vehicle equipped with a shock absorber, which includes means for changing damping force provided in the shock absorber, and a suspension arm installed between a suspension arm and a vehicle body. a trailing link that regulates the longitudinal displacement of the trailing link, a displacement detection means that detects the longitudinal displacement of the trailing link, and a means that changes the damping force of the shock absorber in response to a signal from the displacement detection means. It is equipped with an operating means.

[Effect]

In the vehicle suspension device of the present invention configured as described above, a longitudinal force is applied to the trailing link when the wheel moves up and down, displacing the trailing link in the longitudinal direction. By detecting the displacement of the vehicle with a displacement detection means and changing the damping force of the shock absorber, the road surface condition during driving is directly detected from the vertical movement of the wheels, and the damping force of the shock absorber is obtained according to the road surface condition. It is.

〔Example〕

Embodiments of the present invention will be described based on the drawings.

In the first embodiment shown in FIGS. 1 and 2, one end is supported at the front and rear of a wheel support 2 that rotatably supports a wheel l, and the other end is attached to a vehicle body 3 so as to open toward the inside of the vehicle body. A strut 8 consisting of two suspension arms 4 and 5 whose ends are supported, a shock absorber 6 and a coil spring 7 which are fixed inside the wheel support 2 and whose upper part is elastically supported by the vehicle body. A suspension device is formed by a trailing link 9 whose rear end is supported at the lower part of the vehicle body 3, extends in the longitudinal direction of the vehicle body, and whose front end is supported by the vehicle body 3.

Displacement detection means 10 such as a potentiometer is installed at an appropriate position of the trailing link 9 to detect the displacement of the trailing link 9 in the front-rear direction, and detect the inside of the shunt and link absorber 6 via an action means (not shown). This is to drive a means (not shown) for changing the direction of the shock absorber 6 installed in the cylinder. In this case, an electric motor or the like is suitable as the operating means.

With the above configuration, the displacement of the trailing link 9 in the longitudinal direction due to the longitudinal force acting on the trailing link 9 is detected, and the road surface condition during driving is directly detected from the vertical movement of the wheel l, and the unevenness of the road surface is detected. Shock absorber according to 6
This provides a damping force of .

FIGS. 3 and 4 show a displacement detection means for detecting displacement of the trailing link in the longitudinal direction, and an action means for driving means for changing the damping force of the shock absorber in accordance with a signal from the displacement detection means. Different second and third embodiments are shown.

In FIG. 3, the shock absorber 6 has an outer chamber 6A and an inner chamber 6B formed by an outer cylinder 61 and an inner cylinder 62, and a piston 63 is slidably disposed in the inner chamber 6B. is provided with a throttle stop valve 64, a check valve 65, and a rod 66. In addition, the outer room 6A and the inner room 6B are
They communicate with each other through an opening 6C formed in the upper part of the inner cylinder 62.

A hydraulic pressure adjustment valve 11 is installed at the lower end of the shock absorber 6, and a valve chamber 111 is formed in its main body 110, and the valve chamber 111 is connected to the outer chamber 6A by boats 112 and 113.
A spool valve 114 is slidably disposed within the valve chamber 111, and a spring 115 causes the spool valve 114 to maintain the opening degree of the ports 112 and 113 at a predetermined amount. Forced.

A trailing link 9 is installed between a suspension arm (not shown) and the vehicle body 3, and is connected to a fluid bush 91.9.
2, the pressure chamber 116 of the valve chamber 111
is connected to a fluid chamber of a suspension arm-side fluid bush 91 at the rear end of the trailing link 9 through a conduit 12 passing through the roof plate 117 . Note that 13 is an accumulator.

To explain the operation of the second embodiment, when the wheels move up and down according to the unevenness of the road surface, a backward force F is applied to the trailing link 9 and the trailing link 9 is displaced rearward. Hydraulic pressure is generated in the liquid chamber of the suspension arm side fluid bush 91, and the hydraulic pressure is transmitted to the pressure chamber 116 via the pipe line 12, presses the spool valve 114 against the spring 115, and changes the opening degree of the ports 112 and 113. The outer chamber 6A and the inner chamber 6B are connected via the valve chamber 111 by adjusting the
The damping force of the shock absorber 6 is reduced by changing the resistance of the passage through which the shock absorber 6 communicates.

When a rearward force F is acting on the trailing link 9, the damping force of the shock absorber 6 is always reduced, but depending on the magnitude of the rearward force F, bow) 112, 113
The amount of decrease in damping force changes as the opening degree of the damping force changes. That is, the amount of decrease in the damping force of the shock absorber 6 changes depending on the amount of vertical movement of the wheels in response to the unevenness of the road surface.

Next, a third embodiment will be explained with reference to FIG. Here, the same reference numerals as in FIG. 3 indicate the same parts.

A hydraulic pressure regulating valve 14 is installed at the lower end of the shock absorber 6, and a valve chamber 141 is formed in the vehicle body 140. The valve chamber 141 is connected to the outer chamber 6A by ports 142 and 143.
A spool valve 144 is slidably disposed in the valve chamber 141, and a spring 145,
146 connects the spool valve 144 to ports 142 and 143.
energized to cut off communication.

Both end surfaces of the spool valve 144 serve as pressure receiving surfaces, and pressure chambers 147 and 148 are formed at both ends of the valve chamber 141, and a pipeline 15.
16 communicate with either side of an orifice 18 provided in a conduit 17 which communicates the fluid chambers of the fluid bushes 91,92 supporting the trailing link 9 with one another.

To explain the operation of the third embodiment, when the wheels move up and down in accordance with the unevenness of the road surface, a force F acts backwards on the trailing link 9, displacing the trailing link 9 backwards. , the oil pressure in the liquid chamber of the suspension arm side fluid bushing 91 increases and the oil pressure in the liquid chamber of the fluid bushing 92 on the vehicle body 3 side decreases. 92 through the pipe line 17, a pressure difference is generated between the upstream side and the downstream side of the orifice, and this pressure difference is guided to the pressure chambers 147 and 148 via the pipe lines 15 and 16. Move the spool valve 144,
The damping force of the shock absorber 6 is reduced by adjusting the opening degree of the shock absorber 143.

Depending on the magnitude of the rearward force F acting on the trailing link 9, the degree of opening of the ports 112 and 113 changes, and the amount by which the damping force decreases changes.

That is, the amount of reduction in the damping force of the shock absorber 6 changes due to the vertical movement of the wheels in response to the unevenness of the road surface.

The amount of rearward displacement of the trailing link 9 becomes constant.
That is, when there is no change in the rearward force F, the flow of oil in the pipe line 17 stops and the pressure difference between the upstream side and the downstream side of the orifice 18 disappears, so the spool valve 144 returns to its initial state. Then, the opening degrees of the ports 142 and 143 are returned to their original values, and the damping force of the horizontal absorber 6 is returned to its initial state. This means that the damping force of the shock absorber 6 is returned to its initial state when the vertical movement of the wheels is eliminated, in other words, when the unevenness of the road surface is eliminated.

[Effects of the Invention] Since the present invention is configured as described above, it produces the effects described below.

The vertical movement of the wheels depending on the road surface condition can be directly detected as the amount of rearward displacement of the trailing link, so it is possible to perform highly sensitive @ control, and the damping force of the shock absorber can be adjusted depending on the road surface condition. Since it changes the vehicle speed, it is possible to improve ride comfort.

Furthermore, it can be manufactured at a lower cost than a device that detects road surface conditions using a laser or the like.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the first embodiment of the present invention, Fig. 2 is a rear view, Fig. 3 is an enlarged explanatory view of the main part of the second embodiment, and Fig. 4 is a main part of the third embodiment. It is an enlarged explanatory diagram. l...Wheel, 2...Wheel support, 3...Vehicle body, 4.5...Suspension arm, 6...
・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・１１．１４ Potentiometers, hydraulic regulating valves, orifices, fluid bushings.

Claims (1)

[Claims] (1) In a suspension system for a vehicle equipped with a shock absorber, a means for changing the damping force is provided in the shock absorber, and a means is installed between the suspension arm and the vehicle body to regulate displacement of the suspension arm in the longitudinal direction. The present invention includes a trailing link, a displacement detection means for detecting displacement of the trailing link in the longitudinal direction, and an action means for driving a means for changing the damping force of the shock absorber in response to a signal from the displacement detection means. Characteristic vehicle suspension equipment.