JPS6030564B2 - Vehicle suspension system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle suspension system, and more particularly to a vehicle suspension system having a stacked leaf spring device capable of controlling inter-plate frictional force depending on the running condition of the vehicle.

2. Description of the Related Art Suspension systems used in vehicles such as automobiles generally include a stacked leaf spring device, whose longitudinally intermediate portion is connected to the axle, and both ends are connected to the vehicle body. As is well known, the spring constant and the friction between the plates affect the riding position, steering stability, etc., and the degree of influence also varies depending on the vehicle's running speed, the condition of the road, etc. In general, the ride comfort when driving on a good road is better when there is less friction between the plates, but the steering stability shows a tendency that is contrary to this. On the other hand, in order to reduce the weight of vehicles and improve riding comfort, tapered leaf springs with tapered parts whose thickness decreases as they get closer to the end of the leaf have come to be used. Therefore, in order to improve ride comfort when driving on rough roads, it is necessary to increase the capacity of the shock absorber.

Therefore, in order to increase the friction between the slopes, a clamp mechanism is used that presses the leaf springs against each other in the thickness direction, and is provided near the end of the leaf. However, in the secondary clamp mechanism, the friction between the plates is almost constant, so while it can improve the ride comfort when driving on rough roads, on the other hand, there is a mirror bias that worsens the ride comfort when driving on good roads. . The present invention has been made under the above circumstances, and its purpose is to provide a vehicle that can always maintain optimal ride comfort and stiffness and longitudinal stability, regardless of the running speed or the condition of the rock on which it is running. The purpose of the present invention is to provide a suspension system.

Hereinafter, the present invention will be described with reference to an illustrated embodiment.

In FIG. 1, a stacked leaf spring device 1 constituting a suspension system includes a plurality of leaf springs 2 (in the case of three leaf springs in the figure) stacked in the thickness direction. In the illustrated example, the board and imitation 2...
Although all of these springs are tapered leaf springs, all or some of them may not have a tapered portion. As in the conventional device, the leaf springs 2 are attached vertically in the thickness direction by appropriate means 3 at their longitudinally intermediate portions, and are connected to the axle side (not shown) of the vehicle. A support member 5 is provided on the vehicle body side a of the above-mentioned vehicle to rotatably support an eyeball portion 4 formed at one end in the longitudinal direction of the first leaf spring 2. On the vehicle body side a, the leaf spring 2...
- A clamping machine 6 is provided that can tighten the vicinity of the other end in the thickness direction.

The clasp mechanism 6 includes a first member 7 attached to the vehicle body side a, and a second member 8 facing the first member 7 with the leaf spring 2 interposed therebetween. These first and second members 7
, 8, it is desirable that the mutually opposing top surfaces have an arc shape with an appropriate curvature. The second member 8 is supported so as to be movable up and down via a cylinder device 9 provided on the vehicle body side a. The cylinder device 9 is a valve device 10 having a pressure control valve etc.
It is connected to a pressure fluid supply source 11 via. The valve device 10 is connected to a detection section 13, a manual operation section 14, etc. via a control section 12. The control unit 12 controls the valve device 10 according to input signals from the detection unit 13 or the manual operation unit 14, etc.
It is configured to output a control signal for controlling the
The detection unit 13 is configured to be able to generate signals relating to all or part of, for example, the vertical acceleration, lateral acceleration, angular acceleration, vehicle running speed, rotation angle of the steering wheel, etc. . In the device configured as described above, when the vertical vibration of the vehicle body increases, for example when driving on a rough road, the control unit 12 outputs a control signal based on the output signal from the vertical acceleration sensor in the detection unit 13, The cylinder device 9 is shortened by a desired amount, and the first
, the plate springs 2 are pressed by the second members 7, 8 to increase the friction between the plates.

This increases the vibration damping force in the stacked leaf spring device 1 and improves riding comfort. When the vertical vibration is small, such as when driving on a good road, the friction between slopes is reduced by the opposite operation to that described above, and the original good riding comfort is obtained. Further, when the steering wheel is operated while the vehicle is traveling at high speed, control is performed to increase the friction between slopes in accordance with the output signals from the respective sensors for the traveling speed and the steering wheel rotation angle, for example. By increasing the plate end friction in this way, even if the static spring constant of the stacked leaf spring device 1 is constant, the force spring constant is substantially increased, so that the steering stability can also be improved. Furthermore, instead of automatic control as described above, or when it is necessary to correct the results of automatic control, the slope friction can be controlled in accordance with a signal from the manual operation section 14. It should be noted that the present invention is not limited to the above-mentioned embodiments. For example, a clamp mechanism may be provided at both ends of the stacked leaf spring device 1. In this case, a support member may be provided as illustrated in FIG. 5 may be used instead of the first member 7.

Also, instead of driving the second member 8 directly by the silling device 9, the push cable 1
5, and in this case, a plurality of clamp mechanisms may be driven by one cylinder device. Furthermore, instead of moving the second member 8 linearly, it may be rotated as shown in FIG. 4, which makes it possible to variably control the slope friction and the spring constant at the same time. In addition, various modifications and applications are possible within the scope of the gist of the present invention. As described above, the present invention is provided with a control means that can control the clamping force of the clamp mechanism in the stacked leaf spring device according to the running condition of the vehicle, so that the friction between the plates and the force spring constant can be adjusted according to the running condition. Can be variably controlled.

Therefore, ride comfort and steering stability can always be maintained in an optimal state, regardless of the speed of the vehicle, the condition of the road, etc.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIGS. 2 to 4 are explanatory diagrams showing different modifications of the same example. 1... Layered leaf spring device, 2... Leaf spring, 6...
... Clamp mechanism, 9 ... Schilling device, 10
... Valve device, 12... Control section, 13...
...detection section, 14...manual operation section. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A stacked leaf spring device including a plurality of leaf springs overlapped in the thickness direction, whose longitudinally intermediate portion and both end portions are connected to the axle and the vehicle body, respectively, and the plates of this stacked leaf spring device. and a clamp mechanism provided near an end to tighten the leaf spring in the thickness direction, wherein the clamp mechanism is provided across the body of the vehicle and controls the clamping force of the leaf spring of the clamp mechanism according to the running condition of the vehicle. A suspension system for a vehicle, characterized in that it is equipped with control means capable of controlling the vehicle.