JPH0148161B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is a small four-wheeled vehicle, especially a vehicle with a small passenger capacity, in which the suspension of the two rear wheels, which are the driving wheels, has a semi-independent suspension characteristic. This invention relates to a suspension system for small four-wheeled vehicles.

[Prior art]

Small four-wheeled vehicles, especially those with a small passenger capacity, need to be lightweight because their engine output is low, and they are also required to have sufficient strength and provide a comfortable ride. Ru. In order to meet the above requirements, this type of small four-wheeled vehicle has the front end of a trailing arm, which does not have a bent part, pivoted to the body frame that supports the seat and the vehicle body, and the rear wheel is attached to this trailing arm. and an engine unit.

However, if the rear wheels and engine unit are mounted on a trailing arm (usually two for each left and right rear wheel) that does not have a bending part on its own, the left and right rear wheels can When ascending and descending according to different undulations, two connected
Stress is concentrated in each part of the book's trailing arm,
This part needs to be reinforced as it is easily damaged. On the other hand, if the left and right wheels are independent (full trailing arm) in order to fundamentally improve this, a constant velocity joint, etc. will be required, which will complicate the structure and increase costs.

[Purpose of the invention]

This invention was made in view of this point, and has a simple structure that does not require independent suspension of the left and right wheels, prevents high stress from occurring in each part of the trailing arm, and improves understeer characteristics. The object of the present invention is to provide a suspension system for a small four-wheeled vehicle that can improve running stability by providing the following characteristics.

[Structure of the invention]

In the suspension system for a small four-wheeled vehicle of the present invention, a trailing arm is formed by a left arm and a right arm that are provided in parallel in the front-rear direction, and the front portion of the left arm and the right arm is positioned in the left-right direction. The front ends of the left arm and the right arm are expanded in a direction away from each other from the rod, and the front ends are pivotally connected to the vehicle body frame, and the rear ends of the left arm and right arm are An engine that integrates a rear wheel that is a driving wheel, an engine that drives the rear wheel, a transmission, and a driving wheel shaft, which are connected by a rod and are placed on the left arm and the right arm in the middle between the two rods. It is characterized by being equipped with a unit.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, numeral 1 indicates a small four-wheeled vehicle to which the present invention is applied. This small four-wheeled vehicle 1 has a body frame 2 made of a pipe material whose rear part is bent upward and then extends horizontally, front wheels 3 attached to both sides of the front part of the body frame 2, and A trailing arm 4 whose front end is pivotally connected to an intermediate portion, the details of which will be described later, an engine unit 5 supported in the middle of this trailing arm 4, and a drive wheel shaft (axle) forming a part of this engine unit 5. 6, a steering wheel 8, and a vehicle body 9.
It is composed of. The engine unit 5 is
An engine and a transmission are housed in a case 10 (see FIG. 2), and a drive wheel shaft 6 is projected from a shaft tube 11 projected from both sides of the case 10, and a rear wheel 7 is attached to the end of the shaft tube 6.

FIG. 2 shows the trailing arm 4, which is the essential part of this invention, in a partially exploded state. As shown in this figure, trailing arm 4
is formed by arranging a left arm 12 and a right arm 13 parallel to each other in the front-rear direction. These left arm 1
2 and a bracket 1 near the front of the right arm 13.
9 and 20 are provided facing each other, and this bracket 1
Both ends of a rod 21 in the left and right direction are pivotally connected by shafts 22 and 23 and spanned between the rods 9 and 20.
The front end side of the portion of the left arm 12 and the right arm 13 beyond the part to which the rod 21 is pivoted expands in the direction of moving away from each other to form a figure eight shape. , pipes 14 and 15 whose axes coincide with each other are fixed. A shaft (not shown) is inserted through the pipes 14 and 15, and is attached to a bracket 16 on the vehicle body frame 2 side (see FIG. 1).
It is pivoted to. For this reason, rubber pushers 17 and 18 are interposed inside and at the ends of the pipes 14 and 15 to provide play in connection with the vehicle body frame 2 and at the same time to reduce vibration.

On the other hand, bolts 24 and 25 are projected from the rear ends of the left arm 12 and right arm 13, and a rod 26 is inserted through holes 27 and 28 at both ends between these two bolts 24 and 25. Washiya 29, 30
The rear end of the left arm 12 and the right arm 13 are connected by tightening nuts 31 and 32 through the left arm 12 and the right arm 13, respectively.

Rod 2 of left arm 12 and right arm 13
1 and 26 are attached, there is a bracket 33, which has a recess in the middle part.
34 is attached to receive the aforementioned shaft tube 11. The shaft tube 11 is fixed onto the brackets 33, 34 by retainers 37, 38 which are attached to the brackets 33, 34 via mounting rubbers 35, 36.
Bolts for tightening the retainers 37 and 38 are not shown. 39 and 40 are shock absorbers, respectively, and brackets 41 and 42 are provided near the rear ends of the left arm 12 and the right arm 13;
It is installed between the vehicle body frame 2 and a portion near the rear end thereof (see FIG. 1).

This small four-wheeled vehicle configured in this way 1
is the vertical vibration that the rear wheel 7 receives when driving,
This is absorbed by the rotational force using the front end of the trailing arm 4 as a fulcrum. In this case, when one of the two rear wheels 7 rides on a high part of the road surface, for example, if the left rear wheel 7 bumps as shown in FIG. 7 remains in the state shown by the solid line in FIG. It will come out to the front. Due to this difference in the position of the left and right rear wheels 7, the driving force of the left rear wheel 7 that comes out ahead becomes stronger than that of the right rear wheel 7, and the vehicle body moves in the right direction, that is, the bumped rear wheel 7 Proceed towards the opposite side. When the right rear wheel 7 bumps, the situation is opposite to the above. In this way, when one of the rear wheels 7 bumps, the steering wheel on the bumped side is not grabbed, so running stability is improved. Also the fifth
As shown in the figure, when the side force F is applied during turning, the left arm 12 and the right arm 13 perform a horizontal circular motion as shown by the arrow around the pipes 14 and 15, which are the support points at the front end, and move to the left. Arm 1
2. Since the front end side of the right arm 13 is expanded, the driving wheel shaft does not move in parallel, but is displaced as shown by the chain line, and the direction of the rear wheels 7, 7 is corrected as shown by the chain line, resulting in an understay effect. arise.

〔Effect of the invention〕

Since this invention allows the trailing arm to easily twist up and down, it is possible to absorb stress through the twisting of the trailing arm itself and avoid concentration of stress on specific parts of the trailing arm.

Additionally, when one of the rear wheels rides on a high part of the road surface, or when side force is applied during a turn, the understay side works, improving driving stability.

[Brief explanation of drawings]

Fig. 1 is a side view of a small four-wheeled vehicle to which the present invention has been applied, Fig. 2 is a perspective view showing an embodiment of the invention in an exploded state, and Fig. 3 is a side view of a small four-wheeled vehicle to which the present invention has been applied. The explanatory drawings, FIGS. 4 and 5, viewed from the direction shown in the drawings are schematic diagrams showing the operation of the one shown in FIG. 2. 1...Small four-wheeled vehicle, 2...Vehicle frame,
4... Trailing arm, 5... Engine unit, 7... Rear wheel, 12... Left arm, 13...
Right arm, 21, 26... Rod, 22, 23...
...Axis, 27, 28...hole.

Claims (1)

[Claims] 1 A trailing arm is formed by a left arm and a right arm that are provided parallel to each other in the front-rear direction, and the front portions of the left arm and the right arm are pivotally connected to the tips of rods in the left-right direction, and the left arm The front ends of the right arm are expanded in a direction away from each other than the rods, and the front ends are pivotally connected to the vehicle body frame. An engine unit that integrates a rear wheel as a driving wheel, an engine that drives the rear wheel, a transmission, and a driving wheel axle is mounted on the left arm and the right arm in the middle of the vehicle. Suspension system for wheeled vehicles.