JPH0444408Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field of the Invention) The present invention relates to a rear wheel suspension system for an automobile, and in particular,
The present invention relates to a rear wheel suspension system for an automobile that includes a trailing arm that is swingably connected to the vehicle body via a pivot joint that extends in the lateral direction of the vehicle body.

(Prior art) In a trailing arm suspension system, an attempt is made to improve riding comfort by reducing the rigidity in the longitudinal direction of the vehicle body of the rubber bushing attached to the pivot joint that connects the trailing arm to the vehicle body. Then,
When an automobile turns, compliance steering caused by the elastic deformation of the bushing tends to oversteer, deteriorating steering stability.

A bushing has been developed that keeps the longitudinal rigidity of the vehicle body small and reduces the tendency for oversteer when turning (SAE 810421).
Rear Suspension Design with Front Wheel
Drive Vehicles).

(Problems to be Solved by the Invention) The bushing is configured so that the pivot point of the trailing arm is laterally displaced when the vehicle turns, thereby reducing the oversteer tendency. There is a problem in that the generated lateral force causes lateral displacement of the entire suspension system, reducing running stability.

A rear wheel suspension system for automobiles proposed to solve the above problem (Utility Application No. 140799, 1983;
No. 56106) discloses a rear wheel suspension system including a trailing arm swingably connected to the vehicle body via a pivot joint extending in the lateral direction of the vehicle body, wherein the pivot joint of the trailing arm is connected to the rear wheel suspension device. a rod that is fixed and extends toward at least one of the front and rear sides of the vehicle body; and an elastic member that is fixed to the vehicle body at a portion of the rod that is opposite to the range of upward swinging around the axis of the pivot portion. including the body. The elastic body has an inner circumferential surface curved with a radius of curvature smaller than the arc drawn when the rod swings.

An object of the present invention is to provide a rear wheel suspension system that can provide understeer characteristics to the vehicle without causing lateral displacement during cornering.

(Means for Solving the Problems) The present invention provides a rear wheel suspension system for an automobile that includes a trailing arm that is swingably connected to the vehicle body via a pivot joint that extends in the lateral direction of the vehicle body. A rod fixed to the pivot joint of the trailing arm and extending toward at least one of the front and rear sides of the vehicle body, and a rod facing an upward swinging range about the axis of the pivot joint. The rod includes an elastic body fixed to the vehicle body at a portion thereof, and a plate adhered to the inner circumferential surface of the elastic body, and the inner circumferential surface of the elastic body and the plate form a circular arc drawn when the rod swings. Curved with a small radius of curvature.

(Function) When the automobile turns, the rod receives force from the plate and the elastic body, so the axis of the pivot portion is displaced in the longitudinal direction, causing the vehicle to understeer or tend to understeer (referred to as understeer in this specification). do.

(Embodiment) As shown in FIG. 1, the rear wheel suspension system 10 is constructed by rigidly connecting left and right trailing arms 12 and 14 with a torsion beam 16. A bracket 18 is fixed to the rear end of each trailing arm, and a tire 22 is rotatably supported by a spindle 20 protruding from the bracket 18. Since the above configuration is known per se, detailed explanation will be omitted.

The left and right trailing arms 12 and 14 are arranged symmetrically with respect to a center line extending in the front-rear direction through the center of a vehicle body (not shown). The following description will be made regarding the left trailing arm 12.

A tube 24 is welded to the front end of the trailing arm 12. The tube 24 extends in the lateral direction of the vehicle body and forms a pivot joint. tube 24
A pair of rods 26 and 28 are welded to the body, one rod 26 extending toward the front of the vehicle body, and the other rod 28 extending toward the rear of the vehicle body. In the illustrated embodiment, a pair of rods 26, 28
are the same length.

A rubber bush 30 is bonded to the inner peripheral surface of the tube 24 by vulcanization bonding or other means. The rigidity of the bush 30 in the longitudinal direction of the vehicle body is preferably made small by, for example, providing a hollowed out portion in the longitudinal direction across the axis of the tube 24, and the rigidity in the lateral direction is set large as in the conventional case. Instead of adhering the bush 30 to the tube 24, the bush 30 can be formed by adhering it to the inner cylinder and the outer cylinder, and this can be press-fitted into the tube 24 to incorporate the bush 30 into the tube 24.

As shown in FIGS. 1 and 2, the bracket 32 includes a top portion 34 and a skirt portion 35 that extends downward from the top portion 34 in a substantially trapezoidal shape, and includes a front piece 36 and a rear piece arranged at intervals in the front and rear. 37 and a skirt portion 35 having a pair of side pieces 38 spaced apart in the lateral direction, and is fixed to the vehicle body.

A notch is provided in the rear piece 37 of the bracket 32, and a hole is made in the pair of side pieces 38. The trailing arm 12 is inserted into the notch, the tube 24 is inserted into the space between the pair of side pieces 38, and the bush 30 is held between the side pieces 38. The trailing arm 12 is swingably connected to the bracket 32 by passing a bolt 40 through the bush 30 and the hole and screwing a nut 41 onto the bolt 40.

Elastic bodies 42 and 44 made of rubber are bonded to the inner circumferential surfaces of the front piece 36 and the rear piece 37 of the bracket 32 in the longitudinal direction of the vehicle body, which faces the upward swing range of the rods 26 and 28. There is. Furthermore, a metal plate 46 is adhered to the inner peripheral surface 43 of the elastic body 42, and a metal plate 48 is adhered to the inner peripheral surface 45 of the elastic body 44, respectively. A hollowed out portion 50 is provided in a portion of each elastic body that faces the horizontal rod.

As shown in detail in FIG.
The free end of the elastic body 8 is curved with a smaller radius of curvature than the arcuate plane P drawn when it swings about the axis of the tube 24, and each elastic body is formed so that its wall thickness increases as it goes upward.

The portion of the inner circumferential surface 43 of the elastic body 42 that is located opposite the rod 26 when the rod 26 is in a horizontal state without swinging is the radius of curvature of the arcuate surface P and the thickness of the plate 46. It is preferable that it be curved concentrically with the circular arc surface P with a radius of curvature equal to the sum of the radius of curvature. Further, it is preferable that a portion of the plate 46 that is located opposite the rod 26 when the rod 26 is in a horizontal state without swinging is curved with the same radius of curvature as the arcuate surface P. Inner peripheral surface 45 of elastic body 44 and plate 48
The relationship between the rod 28 and the rod 28 is also similar.

As a result of the above configuration, the elastic bodies 42, 44
The rigidity of the vehicle body in the longitudinal direction is small, and the elastic body exhibits a small restraining force against movement of the rods 26, 28 in the longitudinal direction of the vehicle body when the rods 26, 28 are in a horizontal position where they do not swing. The upper rigidity of the elastic bodies 42 and 44 is large, and when the rods 26 and 28 swing, each elastic body and the plate are
A large force is exerted on the rod facing the plate.

In the illustrated embodiment, the left and right trailing arms 12, 14 are rigidly connected by a torsion beam 16. Instead, the present invention can be implemented with a semi-trailing arm or full trailing arm type suspension system in which the left and right trailing arms are provided independently.

Instead of fixing the rods 26, 28 to the tube 24, they can also be fixed to the outer barrel if the bush 30 is formed by adhesively bonding the inner and outer barrels.

Each trailing arm is rod 26 and rod 2
8, and an elastic body is provided opposite the rod.

(Function of the embodiment) When the automobile equipped with the rear wheel suspension system 10 is running straight, the longitudinal rigidity of the trailing arms 12 and 14 is determined by the bush 30 attached to the tube 24 and the elastic body attached to the bracket 32. 42,
44, the rigidity of the bush 30 is small, and the elastic bodies 42 and 44 have hollowed out portions 50.
Therefore, when the vehicle is traveling straight, shocks in the longitudinal direction of the vehicle body are easily absorbed, resulting in a good ride comfort.

When traveling straight, the pair of rods 26 and 28 do not receive any force from the elastic bodies 42 and 44, so
As shown in FIG. 4, the pivot portion 52 of the trailing arm 12, the pivot portion 54 of the trailing arm 14, and the fixed points 56, 58 on the vehicle body side are not displaced relative to each other, as shown in FIG.

When a car turns, the car body rolls, the tires on the outside of the turn are in a bound state, and the tires on the inside are in a rebound state. Therefore, for example, when the car turns to the left, the rod 28 provided in relation to the outer trailing arm 14 swings upward and hits the plate 48 bonded to the inner circumferential surface 45 of the elastic body 44. , the rods 26 provided in association with the inner trailing arms 12 are swung upwards to face the plates 46 adhered to the inner peripheral surface 43 of the elastic body 42, respectively.

As a result, a forward force is exerted on the rod 28 of the outer trailing arm 14 from the elastic body 44 and the plate 48, and from the elastic body 42 and the plate 46.
Rod 26 of trailing arm 12 inside from
As shown in FIG.
is displaced rearward from the fixed point 56, causing the tire 22 to deflect. This causes the vehicle characteristics to become understeer. In this case, the degree of understeer can be controlled by the radius of curvature and spring constant of the inner circumferential surfaces of the elastic bodies 42 and 44, the shape of the inner circumferential surfaces of the plates 46 and 48, and the like.

(Effects of the invention) According to the invention, when turning, the rod provided at the pivot point of the trailing arm is positioned opposite the elastic body and plate fixed to the vehicle body, and the suspension The force from the plate causes understeer. In other words, if the rod extends forward from the pivot joint, the rod will receive a backward force from the elastic body and the plate when rebounding, and if the rod extends backward from the pivot joint, the rod will receive a backward force when rebounding. When the vehicle bounces, it receives a forward force from the elastic body and plate, resulting in understeer and improved steering stability.

Since the rod slides on a metal or other plate adhered to the inner peripheral surface of the elastic body, the wear resistance of the elastic body is greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the main parts of the rear wheel suspension system according to the present invention, with the bracket shown in a cut state;
2 is a sectional view taken along the line 2-2 in FIG. 1, FIG. 3 is an enlarged sectional view of the main part, and FIGS. 4 and 5 are explanatory diagrams of the operation. 10... Rear wheel suspension system, 12, 14... Trailing arm, 24... Tube, 26, 28...
... Rod, 30 ... Bush, 32 ... Bracket, 42, 44 ... Elastic body, 43, 45 ... Inner peripheral surface, 46, 48 ... Plate, 52, 54 ... Pivotal joint.

Claims (1)

[Scope of utility model registration request] A rear wheel suspension system for an automobile comprising a trailing arm swingably connected to the vehicle body via a pivot joint extending in the lateral direction of the vehicle body, the rear wheel suspension being fixed to the pivot joint of the trailing arm and supporting the vehicle body. a rod extending toward at least one of the front and the rear;
an elastic body fixed to the vehicle body at a portion facing the upward swing range of the rod about the axis of the pivot joint; and a plate adhered to the inner circumferential surface of the elastic body. A rear wheel suspension system for an automobile, wherein the inner circumferential surface of the elastic body and the plate are curved with a radius of curvature smaller than the arc drawn when the rod swings.