JPS6328706A - Rear wheel suspension device in rear two wheel vehicle - Google Patents

Abstract

PURPOSE:To improve travelling performance and control stability on the unleveled ground by arranging the suspension in such a way that a swing arm, a cushion unit and a dowble link type suspension device are combined, in the above-mentioned device for bestriding type four-wheel vehicle. CONSTITUTION:When a rear wheels 11 are rocked by the ups and downs of a road surface 30, the rear wheels 11 are rocked independently of each other by a double link type suspension 12. Accordingly the rock of one wheel is not transmitted to the other. And large ups and downs on the load surface are absorbed by the rocks of the double link type suspension 12 and a swing arm 5. Accordingly, the rock stroke of the rear wheel 11 is secured large. Further since a rear accel shaft 18 is relatively rocked to the rock of the rear wheel 11, the rock angle of the propeller shaft 25 to the rock stroke of the rear wheel 11 can be made small. By this constitution, the travelling performance and control stability on an unleveled ground can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a rear wheel suspension system for a two-wheeled vehicle in which two vehicles are arranged facing each other.

[Prior art] Conventionally, in light vehicles such as straddle-type four-wheeled vehicles, and some tricycles, which have two vehicles attached to the rear of the vehicle, a swing system that is swingably supported on the body frame has been used. On the arm
-The two rear wheels are supported through the main axle and are suspended.

With such a conventional suspension system using a swing arm type, it is possible to secure a large stroke for the rear wheels, which improves the running performance on rough terrain. Therefore, there is a problem in that stroke fluctuations caused by one wheel are transmitted to the other wheel, resulting in a lack of steering stability of the vehicle.

On the other hand, in the past, in addition to the above-mentioned swing arm type suspension system, the rear two wheels were also suspended using independent suspension systems such as the so-called double wishbone type. However, although this type of independent suspension system improves steering stability, it is unable to ensure a large rocking stroke for the rear wheels, and as a result, the running performance on rough terrain is significantly affected. There was a problem that the performance decreased significantly.

(Object of the Invention) In view of the above-mentioned problems, the present invention provides a rear wheel suspension system that improves running performance on rough terrain, handling, and longitudinal stability.

(Configuration of Tl Light) In order to achieve the above-mentioned problems, the present invention includes a swing arm that is freely supported on the vehicle body frame, and a swing arm that is disposed between the swing arm and the vehicle body frame. The rear two wheels include a cushion unit that absorbs swinging of the arm, and a double link suspension that is disposed on the swing arm and independently supports a pair of rear wheels that are arranged opposite to each other at the rear of the vehicle. The swinging motion of the wheels is absorbed by the double link suspension and swing arm.

〔Example〕

Hereinafter, one embodiment of a rear wheel suspension system according to the present invention will be described in detail.

FIG. 1 is a sectional view of a main part of a rear two-wheeled vehicle 2 equipped with a rear wheel suspension system 1 according to the present invention.

The rear two-wheeled vehicle (hereinafter referred to as "vehicle") 2 has a body frame 3 mounted thereon at right angles to the traveling direction (arrow A) of the vehicle body. ,
A moving shaft 4 is arranged on a stake, and a swing arm 5 is supported on this shaft 4. As shown in FIG. 2, which is a cross-sectional view of the main part of FIG. 3 and the arm portion 6.7 shown in FIG.

On the other hand, a pair of suspension wheels 11 are disposed opposite to each other behind the swing arm 5, and this rear wheel 11 is supported by a pair of double link type suspensions 12 disposed on the sides of the swing arm 5. Each is independently supported by As shown in FIG. 3, which is a right side view of FIG. With a double wishbone type suspension, each rear wheel 11 is supported via a drive shaft 16 by a knuckle arm 15 supported at the tips of upper and lower arms 13 and 14. Further, the cushion unit 17 of the double link suspension 12 is connected to the lower arm 14 and the vehicle body frame 3.
2 yen is placed between them.

In addition, in FIGS. 1 to 3, reference numeral 18 is a rear axle shaft, 19 is a bearing that supports this rear axle shaft 18, and drive sprockets 20 are provided at both ends of the rear axle shaft 18, as shown in FIG. and the brake disc 21 are fixed. A drive chain 22 is wound around this drive sprocket 20 as shown in FIG. 2, and the engine 22 shown in FIG.
3 is transmitted to the rear axle shaft 18.

In addition, advance distribution 1? Drive transmitted to axle shaft 18! JJ h is a propeller shaft 25 connected via a pair of universal joints 24 as shown in FIG.
is transmitted to the drive shaft 16 by.

Next, the operation of the rear wheel suspension system 1 described above will be explained.

When the vehicle 2 runs, the rear wheels 11
However, since each rear wheel 11 swings independently due to the double-link suspension 12, the stroke change due to the swing of one rear wheel will be caused by the change in the stroke of the other rear wheel I\.
It will not be transmitted. Furthermore, when driving on rough terrain with large undulations on the road surface 30, the swing stroke of the rear wheel 11 is absorbed by the double link suspension 12 and the swing arm 5, so the swing of the rear wheel 11 relative to the body frame 3 is absorbed. This ensures a large dynamic stroke. In addition, according to the rear wheel suspension system 1 described above, j! of the rear wheel 11! Since the rear axle shaft 18 also swings relative to the ribs, the swing angle of the propeller shaft 25 (FIG. 3) can be reduced relative to the swing stroke of the rear wheel 11.

In the above embodiment, the cushion unit 17 of the double link suspension 12 was installed between the lower arm 14 and the vehicle body frame 3, but the present invention is not limited to the above embodiment, and as shown in FIG. As shown in FIG. 4, where the same parts are designated by the same reference numerals, the cushion unit 1
7 through the mounting member 31 fixed to the swing arm 5,
It may also be installed between the lower arm 14 and the swing arm 5 of the double link suspension 12.

In this way, the cushion unit 17 of the double link suspension 12 is connected to the lower arm 14 and the swing arm 5.
When the displacement of the road surface 30 is transmitted through the shoe control unit 17, the displacement of the road surface 30 is not directly transmitted to the vehicle body frame 3, but is transmitted through the swing arm 5, which improves the behavior of the vehicle body frame 3 with respect to the road surface 30. Changes will be reduced.

[Effects of the Invention] This invention allows the rear two wheels to be suspended by a swing arm that can be freely attached to the vehicle body frame, and a double link suspension installed on this swing arm. A large rocking stroke of the rear wheels is ensured while eliminating interference, and therefore the steering stability and rough terrain running performance of the rear two-wheeled vehicle can be improved. In addition, as the rear axle shaft that drives the rear wheel also swings relative to the swing of the rear wheel, the swing angle of the propeller shaft used in double-link suspensions becomes a small value. It is possible to use a universal joint with a simple structure in place of the normally used constant velocity joint as a joint for connecting the two, and therefore the suspension system can be provided at a low cost. In addition, by changing the length of the swing arm and the arm length of the double-link suspension, the degree of freedom in setting the suspension has been greatly improved. equipment can be provided.

[BRIEF DESCRIPTION OF THE DRAWINGS] Figure 1 shows the rear wheel suspension system according to the present invention.
FIG. 2 is a cross-sectional view of the main part of the wheeled vehicle, FIG. 2 is a cross-sectional plan view of the main part of FIG. 1, FIG. 3 is a right side view of FIG. 1, and FIG. 4 is a side view of another embodiment. 1... Rear wheel suspension system, 2... Rear two-wheel vehicle, 3...
Body frame, 5... Swing arm, 10.17.
...Cushion unit, 12...Double link suspension, 14...Lower arm. Figure 3 Figure 4

Claims (4)

[Claims] (1) A swing arm supported on a vehicle body frame, a cushion unit disposed between the swing arm and the vehicle body frame, and a pair of rear wheels disposed on the swing arm and facing each other. A rear wheel suspension system for a rear two-wheeled vehicle, comprising: a double-link type suspension that supports each independently. (2) A rear wheel suspension system for a vehicle with two rear wheels as set forth in claim (1), wherein the double-link type suspension is a wishbone type suspension. (3) The cushion unit of the wishbone suspension is installed between the lower arm of the wishbone suspension and the vehicle body frame. Rear wheel suspension system for wheeled vehicles. (4) The cushion unit of the wishbone suspension is installed between the lower arm of the wishbone suspension and the swing arm. Rear wheel suspension system for wheeled vehicles.