JPS63101115A - Wheel suspension for vehicle - Google Patents

Abstract

PURPOSE:To improve the comfortableness to ride and driving stability by switching the spring constant and ground clearance of a wheel suspension in two stages respectively via a mechanism combined with a lever and a link by the operation of a hydraulic cylinder. CONSTITUTION:During the normal travel, a piston rod 25 is shrunk by a hydraulic cylinder 22 and a lever 17 is kept at the solid line position, and the ground clearance is set high so as to assure a sufficient wheel stroke. Under this condition, the spring constant becomes low, and the ascent/descent quantity of a spring seat 12 ascended/descended resulting from the ascent/descent of a wheel 2 as the load is increased/decreased is limited to about 1/3 of the ascent/descent quantity of the wheel 2. On the other hand, when the piston rod 25 is extended by the hydraulic cylinder 22, the relative position of the lever 17 is displaced to the virtual line position, a suspension arm 4 is lifted by the rotation of a swaying lever 9, and the ground clearance is lowered and the spring constant is increased concurrently. Accordingly, the ascent/descent quantity of the spring seat 12 is also increased. According to this constitution, the comfortableness to ride and driving stability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wheel suspension system for a vehicle that can change the vehicle height and the spring constant in two stages.

In general, lowering the spring constant of the wheel suspension system improves the ride comfort of the vehicle, but when driving at high speeds or turning, the posture of the vehicle body becomes unstable, reducing steering stability and becoming dangerous. be. Therefore, in such a case, it is preferable that the spring constant be higher.

Generally speaking, the higher the height of the vehicle, the greater the vertical movement stroke of the wheels, which improves ride comfort, but when driving at high speeds or turning, the posture of the vehicle becomes unstable.
It is dangerous because the steering stability decreases. Therefore, in such a case, it is desirable that the height of the vehicle be lower.

Therefore, the present invention makes it possible to switch the spring constant of the wheel suspension system into two stages, high and low, and at the same time, the vehicle height can also be changed into two stages, high and low. The object of the present invention is to provide a wheel suspension system that can maintain comfortable riding comfort and handling stability, and its features are as follows.

A knuckle that rotatably supports a wheel, a suspension arm that supports this knuckle at its tip and whose base end is pivotally connected to the vehicle body so as to be able to swing vertically, and a predetermined position between both ends of this suspension arm. a rocking lever pivotally connected to the knuckle so as to be rotatable in the vertical direction; a shock absorber having a lower end fixed to the knuckle and an upper end supported by the vehicle body above; and a spring fitted into the shock absorber so as to be vertically slidable. A seat, a connecting rod that pivotally connects the spring seat and the tip of the swing lever, and a coil spring interposed between the spring seat and the vehicle body above, which can be rotated vertically at a predetermined position on the vehicle body. A lever is pivotally connected to the lever, a link rod is pivotally connected to one end of the lever and the lower end of the swing lever, and a hydraulic cylinder is interposed between the other end of the lever and the vehicle body.

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings. First, in FIGS. 1, 2, and 3, 1 is a vehicle body, 2 is
is a wheel; 3 is a knuckle that rotatably supports the wheel; 4 is a knuckle that rotatably supports the wheel;
is a suspension arm, and the suspension arm 4 is attached at its base to a bracket 5 fixed to the vehicle body 1 via a bush 6 made of an elastic material and a shaft 7 so as to be swingable in the vertical direction, and its tip end It is pivotally connected to the lower part of the knuckle 3. A shaft 8 is fixed to the front and back of a predetermined position between both ends of this suspension arm 40, and a pair of front and rear swing levers 9 are attached to this shaft 8.
The center part is attached so that it can rotate in the vertical direction. Further, a lower end portion of a bumper buffer 10 is fixed to the upper part of the knuckle 3, and the upper end portion of the buffer device 10 is supported by the vehicle body 1 above via an elastic support member 11. Further, a spring seat 12 is fitted onto the outer peripheral wall of the shock absorber 10 so as to be slidable up and down in the axial direction of the shock absorber 10. A coil spring 13 is interposed between this spring seat 12 and the upper vehicle body 1.

Reference numeral 14 denotes a connecting rod having a substantially inverted U shape, the upper end of which is connected to the spring seat 12 with a pin 15, and the lower end of which is connected to the tip of the swinging lever 9 with a pin 16. . A lever 17 is attached to a predetermined position of the bracket 5 to which the base end of the suspension arm 4 is pivotally attached via a shaft 18 so as to be rotatable in the vertical direction. Reference numeral 19 denotes a link rod, one end of which is connected to the lower end of the swing lever 9 with a pin 20, and the other end connected to one end of the lever 17 with a pin 21. 22 is a hydraulic cylinder, and the base of this hydraulic cylinder 22 is connected to a bracket 23 fixed to the vehicle body 1 with a pin 24. The tip of a piston rod 25 that is extendably inserted into the hydraulic cylinder 22 is connected to the other end of the lever 17 with a pin 26. 27 is the suspension arm 4 and the vehicle body 1
This is a radius rod interposed in between in a substantially diagonal front-rear direction.

The present invention is constructed as described above, and its operation will be explained with reference to FIGS. 4, 5, 6, and 7.

First, when the vehicle is running normally, hydraulic cylinder 2
2 is actuated to retract the piston rod 25, thereby bringing the relative position of the lever 17 to the solid line position shown in FIG. In this state, the vehicle height should be set high to ensure sufficient wheel stroke. FIG. 5 is an explanatory diagram showing the action in running in this state, so to explain the action in running in this state, during running,
When the wheel 2 moves up and down as the load increases or decreases and rises from the solid line position to the upper imaginary line position, the spring seat 12 also rises to the upper imaginary line position accordingly.

The rising amount S of the spring seat 12 is only a small amount (approximately) equal to the rising amount of the wheel 2.

Therefore, in order to generate elastic force in the coil spring 13 that balances the load applied to the wheel 2, the wheel 2 moves with a relatively large stroke, and such operating characteristics are represented by the spring characteristic line X in FIG. be able to. After all, the spring constant in this case is relatively low.

By the way, as mentioned above, if the spring constant is low and sufficient wheel stroke is ensured, the cushioning effect will be soft and a good ride comfort will be obtained. becomes unstable, resulting in a reduction in maneuvering stability. In such a case, the hydraulic cylinder 22 is actuated to extend the piston rod 25, thereby displacing the relative position of the lever 17 from the solid line position shown in FIG. 4 to the phantom line position. In response to this, the swing lever 9 rotates, and the relative angle to the suspension arm 4 changes, thereby displacing the suspension arm 4 to the upper imaginary line position and lowering the vehicle height. Since FIG. 7 is an explanatory diagram showing the action in running in this state, the action in running in this state will be explained using it.During running, the wheel 2 moves up and down as the load increases and decreases, and the wheel 2 moves upward from the solid line position to the imaginary line position. When the spring seat 12 rises, the spring seat 12 also rises to the upper imaginary line position. The amount of rise S of the spring seat 12 is relatively large, approximately divided by the amount of rise of the wheel 2. Therefore, the movement stroke of the wheel 2 to generate an elastic force in the coil spring 13 that balances the load applied to the wheel 2 is relatively small, and such operating characteristics are similar to the spring characteristic line Y in FIG. It can be expressed as After all, since the spring constant in this case is relatively high (9), it is possible to effectively prevent the attitude of the vehicle body 1 from becoming unstable.

As described above, according to the present invention, the spring constant and vehicle height can be switched between high and low levels by operating the hydraulic cylinder. The height can be changed to two levels, high and low, which has the effect of always maintaining good ride comfort and handling stability.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of the device of the present invention;
Figure 2 is a partially cutaway plan view of Figure 1, Figure 3 is A of Figure 1.
- A cross-sectional view taken along line A, FIGS. 4 and 5 are action explanatory diagrams of an embodiment of the device of the present invention, FIG. 6 is a spring characteristic diagram, and FIG. 7 is an action of an embodiment of the device of the present invention. It is an explanatory diagram. 1...Car body, 2...Wheels, 4...
...Suspension arm, 9... Swing lever, 10...
...Buffer, 12...Spring seat,
14...Connecting rod, 17...Lever, 1
9...Link rod, 22...Hydraulic cylinder.

Claims (1)

[Claims] 1 A knuckle that rotatably supports a wheel, a suspension arm that supports this knuckle at its tip and whose base end is pivoted to the vehicle body so as to be able to swing vertically, and a predetermined distance between both ends of this suspension arm. a rocking lever pivotally mounted to the position so as to be rotatable in the vertical direction; a shock absorber having a lower end fixed to the knuckle and an upper end supported by the vehicle body above; and a shock absorber fitted into the shock absorber so as to be vertically slidable. A spring seat, a connecting rod that pivotally connects the spring seat and the tip of the swinging lever, a coil spring interposed between the spring seat and the upper vehicle body, and rotates vertically at a predetermined position on the vehicle body. a lever pivotally connected to the lever; a link rod pivotally connecting one end of the lever to a lower end of the swinging lever;
A wheel suspension system for a vehicle, characterized in that a hydraulic cylinder is interposed between the other end of the lever and the vehicle body.