JPH0615355B2 - Vehicle suspension - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a suspension system for a vehicle, and more particularly to an improvement of a wishbone suspension system in which wheels are supported by a support arm composed of a pair of front and rear arms.

[Prior art]

In the wishbone type suspension device, a pair of front and rear arms form a support arm, and a pair of bearings are provided at the inner end of the support arm in the front and rear, so that the support arm can be smoothly swung. In order to do so, it is preferable that the shaft centers of the pair of front and rear bearing portions are surely aligned with each other.
For this reason, as described in JP-A-58-164428, in a small vehicle such as a motorcycle, the pair of front and rear bearing portions are provided in a lower portion of the vehicle body so as to extend in the front-rear direction. It is attached to the frame.

By the way, since a large load is applied to the portion to which the bearing portion is attached via the support arm, a large twist acts on the pair of left and right lower frames to which the bearing portion is attached.
Therefore, it is necessary to use a pipe having a considerably large diameter for the lower frame. However, in the case of a small vehicle, there is a limit in increasing the diameter of the pipe because there is a restriction on the distance from the road surface.

Further, in a small vehicle, since the distance between the road surface and the lower frame is small, an obstacle is likely to come into contact with the bearing portion, and particularly in the case of a vehicle traveling on a rough land such as off-road, the tendency is further increased. Become.

[Object of the Invention]

An object of the present invention is to provide a suspension device for a vehicle that can improve the strength of the lower frame without narrowing the gap with the road surface, and that makes it difficult for obstacles to hit the bearing portion of the wheel support arm. To provide.

[Structure of Invention]

The present invention for achieving the above-mentioned object, while one end of a pair of front and rear support arms is swingably supported by a pair of left and right lower frames extending in the front-rear direction at the lower part of the vehicle body via a pair of front and rear bearing portions, In a vehicle in which wheels are supported at the other end, a plate member is bridged over the pair of left and right lower frames, and the pair of front and rear bearing portions are attached to an upper surface of the plate member.

Example of Invention

 The present invention will be described below with reference to the embodiments shown in the drawings.

In the small four-wheeled motor vehicle shown in the figure, 1 is a bearing, which is fixed to a bracket 1a fixed to the front end of the main frame 2. A single down tube 3 extending obliquely rearward and downward is fixed to the front portion of the main frame 2. At the lower end of the down tube 3, a pair of left and right lower frames 4 and 4 extending in the front-rear direction is fixed via a laterally extending connecting pipe (not shown). The engine 5 is mounted on the lower frames 4 and 4 located rearward of the down tube 3, and the main frames are connected to the front ends of the lower frames 4 and 4 extending forward from the down tube 3 via a connecting pipe 20. Front pipes 6, 6 extending diagonally forward and downward from the front part of 2
The lower end of is connected and fixed. Reference numeral 7 is a bumper mounted in front of the connecting pipe 20.

The left and right front wheels 8 and 8 are equipped with rear wheels 20 and 20 and low-pressure tires having an air pressure of about 0.1 to 0.3 kg / cm ² . Further, 9 and 9 are so-called wishbone type support arms composed of a pair of front and rear arms. The front wheels 8 and 8 are the outer ends 9a of the support arms 9 and 9, respectively.
It is supported by 9a via a kingpin (not shown). A pair of front and rear bearings 10, 10 are provided at the inner ends of the support arms 9, 9 and are supported at the center of the vehicle body. The pair of front and rear bearings 10, 10 are pivotally supported by brackets 12, 12 having a U-shaped cross section fixed to the upper surface of the plate member 11, and the plate member 11 is slightly slanted to the front in the inclined state. It is hung and fixed on the upper surfaces of the lower frames 4 and 4. Further, the support arm 9 is elastically supported by the shock absorber 13 at a position near the outer end of the support arm 9 with respect to the front pipe 6 in the axially supported state. The longitudinal direction of the shock absorber 13 is made to substantially coincide with the inclination direction of the front pipe 6 so that the front pipe 6 does not receive an excessive bending moment against an impact from the front wheel 8 and is sufficiently endured. is there.

The plate member 11 is provided with a bearing portion 15 for supporting the lower end of the steering shaft 14 at a substantially central portion thereof, and through holes 16, 16 are formed on both left and right sides thereof. In this way, the steering shaft 14
By supporting the lower end of the steering plate 14 with the plate member 11, the steering shaft 14 is supported reliably.

The bearing portion 15 is composed of a pipe material 15a fixed to the plate material 11, and metal bearings 15b and 15b press-fitted into both ends of the pipe material 15a. The steering shaft 1 having a solid shaft member 14a only at the tip end thereof is attached to the bearing portion 15.
The tip of 4 is rotatably supported. A cover 17 is fixed to the back surface of the plate member 11 corresponding to the bearing portion 15 to protect the shaft end of the steering shaft 14. Reference numeral 18 denotes a pitman arm fixed to the shaft material 14a of the steering shaft 14. The pitman arm 18 is a tie rod 1
Via knuckles 9 and 19, knuckle arms (not shown) provided on the front wheels 8 and 8 are connected.

According to the above-described suspension device, the bearing portion 10 of the support arm 9
The plate material 1 attached to the lower frames 4 and 4
Since it is applied to the upper surface of No. 1, the plate member 11 having this large area is subjected to the load applied to the bearing portion 10 and dispersed. Therefore, the plate member 11 can improve the strength of the left and right lower frames 4 and 4 without increasing the diameter. Therefore, even a small vehicle can secure a sufficient distance from the road surface. Further, since the bearing portion 10 is attached to the upper surface of the plate material 11, it is protected against the road surface and the obstacle is hard to hit. Therefore, it is particularly advantageous when applied to a vehicle for traveling on rough ground such as off-road.

Further, when the plate member 11 is inclined and fixed upward as in the above-described embodiment, the torsional moment is not applied to the support arm 9 during the rough terrain traveling so that the support arm 9 can be swung smoothly. As a result, riding comfort can be improved. That is, when traveling on a rough terrain, the uneven road surface mainly hits the tread surface of the front wheel 8 diagonally forward and downward, and the reaction force acts diagonally upward and rearward on the front wheel 8. Further, by fixing the plate member 11 at an inclined position, it becomes more difficult for an obstacle to hit the bearing portion 10.

In the above-mentioned embodiment, the case of the suspension device for the front wheels has been described, but the mechanism of the present invention can also be applied as a suspension device for the rear wheels. Further, the present invention is particularly effective for a four-wheeled vehicle or a three-wheeled vehicle for running on rough terrain equipped with low-pressure tires, but is also applicable to other vehicles equipped with general tires.

〔The invention's effect〕

As described above, the suspension device of the present invention swingably supports one end of the pair of front and rear support arms to the pair of left and right lower frames extending in the front-rear direction at the lower part of the vehicle body through the pair of front and rear bearing portions, In a vehicle with wheels supported at the other end, a plate member is laid over the pair of left and right lower frames, and the pair of front and rear bearings is attached to the upper surface of the plate member.
The load applied to the bearing portion is received by the plate material having a large area, and the lower frame is reinforced without increasing the size. Therefore, the gap between the lower frame and the road surface can be kept wide, and the bearing portion of the support arm is protected against the road surface by the plate member, so that contact of the obstacle with the bearing portion can be eliminated.

[Brief description of drawings]

1 is a side view of a four-wheeled motor vehicle equipped with a suspension system according to an embodiment of the present invention, FIG. 2 is a view taken along the line II-II of FIG. 1, and FIG.
FIG. 4 is a view on arrow III-III in FIG. 2. FIG. 4 is a view on arrow IV-IV in FIG. 4 ... Lower frame, 8 ... Front wheel, 9 ... Support arm, 1
0 …… Bearing part, 11 …… Plate material, 12 …… Bracket.

Claims (1)

[Claims] 1. A pair of front and rear support arms is swingably supported by a pair of left and right lower frames extending in the front-rear direction at a lower portion of a vehicle body through a pair of front and rear bearings, and a wheel is supported at the other end. In the vehicle described above, a suspension device for a vehicle, characterized in that a plate member is bridged over the pair of left and right lower frames, and the pair of front and rear bearing portions are attached to an upper surface of the plate member.