JPH1076826A - Rear wheel suspension device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rear wheel independent suspension device of compact structure and with high operating performance which can achieve a low floor structure of a rear floor. SOLUTION: A rear wheel suspension device concerned is composed of a swing arm 1 whose front end is pivoted on a vehicle body with possibility of swinging up and down and rear end supports the rear wheels rotatably, a lower link 8 whose external end is pivoted on the tail lower part of the swing arm, a buffer device 14 whose top is pivoted on the vehicle body and bottom is pivited on the lower link 8, and an A-type upper link 16 whose inner end is pivoted at two points on the buffer device 14 and external end is pivoted on the tail upper part of the swing arm 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear wheel suspension system for a motor vehicle, and more particularly to an independent rear wheel suspension system capable of expanding a cabin space as a floor is lowered.

[0002]

2. Description of the Related Art In recent years, RV-type vehicles have attracted attention due to an increasing need for an outdoor boom. In particular, this RV
There are high demands for system-based vehicles, for example, to increase the cabin space and improve the loadability of luggage, and there is an extremely high demand to lower the floor height. On the other hand, in the RV system, a high-performance suspension is required to ensure stability due to the fact that the load fluctuates greatly with the loading and the vehicle height is high and the center of gravity is extremely high.

[0003] However, the above two requirements have a conflicting relationship. When the floor is lowered, the suspension space is reduced, and it is extremely difficult to employ a high-performance suspension. There is a problem that the appeal as an RV is reduced. Chassis developers of each automobile manufacturer are focusing on the development of rear wheel suspension systems to satisfy these requirements on a higher level.

Incidentally, as a structure of a rear wheel suspension device which can satisfy the above-mentioned requirements to some extent, for example, a rear wheel suspension device as disclosed in Japanese Patent Publication No. 63-55445 has been proposed. In recent years, there have been cases in which this structure is actually used in RV vehicles.

In this structure, a swing arm having a front end pivotally attached to a vehicle body and a rear wheel rotatably supported at a rear end is provided. One upper and lower upper and lower arms are provided at the rear end of the swing arm. The rear wheel suspension device is constructed by pivotally connecting to a vehicle body via a link. As a result, the size of the suspension body and the size of the cross member are reduced in accordance with the reduction in the number of links while the performance of the suspension is improved, and the floor is lowered.

[0006]

However, even in the structure of the prior art described above, the size of the suspension cannot be reduced enough to sufficiently lower the floor, and the performance of the suspension cannot be improved so much. It is not enough in terms of achieving a balance between lowering the floor in dimensions and suspension performance.

To explain this point in detail, in the suspension having the above-described structure, since the upper link is disposed longer in the vehicle width direction between the vehicle body and the swing arm, the upper link is disposed between the upper link and the lower surface of the floor at the time of wheel bumping. This causes a problem of interference with the installed side frame, and the side frame cannot be lowered so much to avoid this interference, and the floor height cannot be reduced accordingly.

In order to avoid the interference with the side frame, it is conceivable to form an interference preventing portion bent downward to avoid the interference with the side frame in the upper link. Therefore, interference with the drive shaft located at the rear side cannot be avoided, and eventually the front side frame cannot be lifted, and the floor of the rear floor cannot be sufficiently reduced.

In view of the suspension performance, the present suspension is composed of one I-type link for each of the upper and lower parts. Since the suspension alignment is determined only by the arrangement of the two links. It has a low degree of freedom in setting the suspension alignment, which is a disadvantageous structure for sufficiently improving the maneuverability.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a compact and high-performance independent rear-wheel suspension system which can achieve a sufficiently low rear floor while having a sufficiently high performance. The purpose is to do so.

[0011]

According to the present invention, there is provided an independent rear wheel suspension device according to the present invention, wherein a front end is pivotally attached to a vehicle body so as to be vertically swingable, and a rear end rotatably supports a rear wheel at a rear end. A lower link having an outer end pivotally attached to a lower rear end of the swing arm, a shock absorber having an upper end pivotally connected to the vehicle body, and a lower end pivotally connected to the lower link, and an inner end being connected to the shock absorber. And an upper link pivotally attached to an upper end of a rear end of the swing arm.

[0012]

The effect of the present invention based on the above structure is that the upper link is pivotally connected to the shock absorber, so that the upper link can be extremely short, and it is necessary to consider the interference with the side frame. Absent. Also, if the upper link is short, the camber performance and the like tend to deteriorate, but in this type of suspension, since the camber change is determined by the synergistic operation with the shock absorber, the suspension performance does not decrease.

Since the upper link is pivotally connected to the shock absorber, the suspension alignment is determined by the layout of the shock absorber.
It is easy to ensure high maneuverability.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a simplified perspective view showing the entire left rear wheel independent suspension device according to the present invention, FIG. 2 is a plan view of the rear wheel suspension device according to the present invention, FIG. 3 is a front view, and FIG. It is a side view.

In FIG. 1, reference numeral 1 denotes an extremely rigid swing arm formed in a U-shaped cross section. The swing arm 1 has a front end 2 vertically mounted on a vehicle body (not shown) via a swing arm bush 3. It is pivotally supported and swingable.
A drive shaft support 6 for rotatably supporting a drive shaft 5 is formed at the rear end 4 of the swing arm 1. The drive shaft 5 is inserted through the drive shaft support 6, and a wheel is inserted into the drive shaft 5. The wheel 7 is rotatably supported by fixing the hub.

In this embodiment, the swing arm 1 and the drive shaft support are integrally formed. However, the swing arm 1 and the wheel support having the drive shaft support are divided into two parts. It goes without saying that they may be integrated by being connected.

In the figure, reference numeral 8 denotes a lower link. The inner end 9 of the lower link 8 is pivotally connected to the vehicle body via a bush 11, and the outer end 10 is connected to the lower end of the swing arm 1 via a bush 12. Pivotally supported.

A lower end of a shock absorber 14 is pivotally connected to an intermediate portion 13 of the lower link 8 via a joint, so that the shock absorber 14 can rotate about an axis. On the other hand, the upper end of the shock absorber 14 (the upper end of the piston rod) is elastically pivotally supported on the vehicle body via the mount bush 15, and is connected so as to be able to slightly swing in the vehicle width direction and the vehicle front-rear direction. Is what is being done.

The upper link 16 configured in the A-shape
An outer end 17 is pivotally connected to an upper end of the swing arm 1 via a ball joint 18, and an inner end 19 is connected to the shock absorber 1.
The front and rear shafts 20 so that only the up and down swing can be performed on the main body 14A of the shock absorber 14 at two points in the front and rear direction so as to straddle the
It is pivotally supported via.

In FIG. 1, reference numeral 21 denotes a coil spring disposed between the swing arm 1 and the vehicle body, and reference numeral 22 denotes a differential device for distributing a driving force while performing a differential between left and right rear wheels.

According to the suspension device of the present invention configured as described above, since the inner end 19 of the upper link 16 is pivotally supported by the shock absorber 14, the length of the upper link 16 itself is reduced. The upper link does not interfere with the side frame 24 or the drive shaft 5 provided on the lower surface of the rear floor 23 unlike the prior art. Therefore, not only can the rear floor 23 be lowered and the interior space can be expanded, but also the luggage loading and getting on and off can be improved as much as possible, which is particularly attractive for RV vehicles. Can be tailored as a car.

On the other hand, when the upper link 16 is shortened, the camber performance tends to be greatly reduced due to the effect of the short link itself (because the amount of pull-in becomes large) and the effect of imbalance with the lower link 8. However, in this type of suspension, the camber performance is not only controlled by the upper link 16 but also by the shock absorber 14.
Therefore, the camber performance is not degraded, and the steering stability in a high dimension can be ensured. (Actually, the amount of swing of the upper link 16 is determined by the mounting point of the shock absorber 14 with respect to the lower link 8.) Further, the direction of the mounting axis of the shock absorber 14 with respect to the lower link 8 and the shock absorption of the upper link 16 are determined. The camber, the toe, and the
Performance such as pitching can be made favorable, further tuning of suspension alignment becomes possible, and higher steering stability can be obtained.

In the suspension according to the present invention, the upper link 16 must be pivotally attached to the shock absorber 14 so as not to swing back and forth.
The adoption of an A-shaped arm having two attachment points for the A.4 results in extremely high rigidity, which can be expected to further improve the steering stability as the lateral rigidity is improved.

In this embodiment, the upper link 16 is constituted by an A-type arm.
Needless to say, the structure may be changed to a mold arm, and the lower end of the shock absorber 14 may be pivotally connected to the lower link via the front-rear shaft so that the shock absorber main body 14A does not rotate.

[Brief description of the drawings]

FIG. 1 is a simplified perspective view of a rear wheel suspension device according to the present invention.

FIG. 2 is a plan view of a rear wheel suspension device according to the present invention.

FIG. 3 is a front view of the rear wheel suspension device according to the present invention.

FIG. 4 is a side view of the rear wheel suspension device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Swing arm 2 Front end of swing arm 3 Swing arm bush 4 Rear end of swing arm 5 Drive shaft 6 Drive shaft support part 7 Wheel 8 Lower link 9 Inner end of lower link 10 Outer end of lower link 11 Bush 12 Bush 13 Intermediate portion of lower link 14 Shock absorber 15 Mount bush 16 Upper link 17 Outer end of upper link 18 Ball joint 19 Inner end of upper link 20 Front-rear shaft 21 Coil spring 22 Differential device

Claims (1)

[Claims] 1. A rear arm suspension device for a motor vehicle, comprising: a swing arm having a front end pivotally attached to a vehicle body so as to be vertically swingable, and a rear end rotatably supporting a rear wheel; A lower link pivotally connected to the outer end of the lower link; a shock absorber having an upper end pivotally connected to the vehicle body; a lower end pivotally connected to the lower link; an inner end pivotally connected to the shock absorber; A rear wheel suspension device for a vehicle, comprising an upper link pivotally mounted on an upper portion of a rear end of an arm.