JPH05278421A - Rear suspension of automobile - Google Patents

Abstract

PURPOSE:To satisfy both a good operation stability and a riding comfortableness by composing the lateral link of a trapezoid lower arm separately from the trailing arm of the lower arm, and combining the outer end of the lateral link to the trailing arm to allow to fluctuate freely in the longitudinal direction. CONSTITUTION:The lateral link 12 of a trapezoid lower arm 1 is composed separately from the trailing arm 11 of the lower arm 1, the lateral link is combined to the trailing arm 11 through a ball joint or a bush 11a, and the lateral link 12 is made possible to fluctuate in the longitudinal direction to the trailing arm 11. And the included angle alpha of the fluctuating axis X-X of the trapezoid lower arm 1 and the lateral link 12 is made in an acute angle. As a result, by making a bush 12a hard and the bush 11a of the trailing arm 11 soft, the lateral rigidity is increased to improve the operation stability, and the longitudinal rigidity is reduced to improve the riding comfortableness. And since the angle alpha is made in an acute angle, the steering-in condition is made in a braking so as to improve the stability in the turning braking operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile rear suspension.

[0002]

2. Description of the Related Art A rear suspension for a vehicle using a trapezoidal lower arm is disclosed in, for example, Japanese Patent Laid-Open No. 63-270.
It is conventionally known as disclosed in Japanese Patent Laid-Open No. 207.

[0003]

For example, as shown in FIG. 4, a multi-link rear suspension using a trapezoidal lower arm a has an advantage that it has a small number of parts and is simple, but has a lateral rigidity. When the bushes mounted on the vehicle body side attachment portion of the lateral link portion b are made hard to increase the steering stability, the lateral link portion b and the trailing arm portion c are integrated, so that the longitudinal rigidity is increased. It is also not preferable from the standpoint of improving the riding comfort, and it is difficult to satisfy both the steering stability and the riding comfort. Further, there is a problem that it is difficult to prevent the toe-out change of the tire when a backward force such as a braking force is applied, and there is a difficulty in improving stability during braking.

An object of the present invention is to solve the above problems of the trapezoidal lower arm type multi-link rear suspension.

[0005]

According to the present invention, in a vehicle multi-link rear suspension using a trapezoidal lower arm as described above, the lateral link portion of the trapezoidal lower arm is formed separately from the trailing arm portion, and the lateral link portion is formed separately from the trailing arm portion. The first feature is that the outer end of the link part is connected to the trailing arm part so as to be swingable in the front-rear direction, and the angle formed between the vertical swing shaft of the trapezoidal lower arm and the lateral link part is an acute angle. This is the second feature, and the third feature is that the upper link and the trailing arm portion are connected so as to be suspended by a connecting rod.

[0006]

As described above, the lateral link of the trapezoidal lower arm is connected to the trailing arm so as to be swingable in the front-rear direction, so that the rigidity of the suspension in the front-rear direction is fixed to the vehicle body side member at the inner end of the lateral link part. The trailing arm can be set only by the rigidity of the bush at the front end of the trailing arm, regardless of the rigidity of the bush inserted in the section. By softening the bush at the front end of the member to reduce the rigidity in the front-rear direction, both stability and ride comfort can be achieved. Also, by making the included angle between the vertical swing axis of the trapezoidal lower arm and the lateral link part an acute angle, the wheels toe-in change when a rearward force is applied to the wheels, improving stability during braking, especially during turning braking. You can Furthermore, by connecting the upper link and the trailing arm portion with the connecting rod, it is possible to prevent the trailing arm portion from falling due to the brake torque.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a trapezoidal lower arm, 2 is an upper link, 3 is a connecting rod, and 4 is a housing which is a wheel support.

The trapezoidal lower arm 1 is composed of a trailing arm portion 11 and a lateral link portion 12, and conventionally, the trailing arm portion 11 and the lateral link portion 12 are integrally formed, but in the present invention, the trailing arm portion is formed. The portion 11 and the lateral link portion 12 are separately configured, and the lateral link portion 12 is rotatably coupled to the trailing arm portion 11.

That is, the trailing arm portion 11 is formed in such a shape that the width becomes gradually wider at the rear, and the widest rear end portion is connected to the lower portion of the housing 4 so as to be vertically swingable at two front and rear portions of the wheel center. The narrow front end is attached to a vehicle body-side member (not shown) such as a side frame by a bush 1.
The lateral link portion 12 is rotatably attached via the la 1 and is configured as a separate component from the trailing arm portion 11. It is rotatably coupled and its inner end is attached to a vehicle body-side member (not shown) so as to be vertically swingable via a bush 12a. The swing axis X-X of the trapezoidal lower arm 1 composed of the trailing arm portion 11 and the lateral link portion 12 is inclined so that the front extends outward with respect to the center line of the vehicle body, and the swing axis XX and the lateral link portion. The included angle α with 12 is set to an acute angle.

An upper end of the upper link 2 is vertically swingably coupled to an upper portion of the housing 4, and an inner end of the upper link 2 is vertically swingably mounted to a body side member (not shown) through a bush 2a. The lower end 3 of the trailing arm 11 is rotatably mounted near the rear end of the trailing arm 11, and the upper end of the upper link 2 is rotatably mounted near the outer end of the upper link 2.

As described above, the trailing arm portion 11
And the lateral link portion 12 are pivotally connected to each other so that the suspension can swing in the longitudinal direction, the longitudinal rigidity of the suspension is almost independent of the rigidity of the bush 12a interposed in the mounting portion of the lateral link portion to the vehicle body side member. In addition, the rigidity can be set only by the rigidity of the bush 11a interposed in the mounting portion of the trailing arm portion 11 to the vehicle body side member. Therefore, the bush 12a of the lateral link portion 12 is hardened to increase the lateral rigidity to improve the maneuverability, and the bush 11a of the trailing arm portion 11 is softened to optimize the front-rear rigidity for riding comfort. It is possible to set it as low as possible, and it is possible to achieve both maneuverability and ride comfort that were difficult in the past.

Further, as described above, the angle α between the swing axis XX of the trapezoidal lower arm 1 and the lateral link portion 12 is set to an acute angle, so that the wheels are toe-in when a rearward force is applied to the tire during braking. It is possible to change and improve the stability during turning braking. That is, as shown in FIG. 3, when a rearward force is applied to the wheel 5, the trailing arm portion 11 is displaced rearward and the lateral link portion is rearwardly displaced due to the rearward deformation of the bush 11a of the trailing arm portion 11 as shown by the chain line. However, when the included angle α between the swing axis XX and the lateral link portion 12 is an acute angle, the pivot point between the trailing arm portion 11 and the lateral link portion 12 is displaced toward the inner side of the vehicle body. The wheel 5 changes its toe angle in the toe-in direction by γ, and the stability during braking, especially during turning braking, is improved.

Furthermore, since the upper link 2 and the trailing arm portion 11 are connected so as to be suspended by the connecting rod 3, the trailing arm portion 11 is prevented from falling down due to the brake torque.

As shown in FIG. 1, assuming that the upper and lower mounting positions of the connecting rod 3 with respect to the upper link 2 and the trailing arm portion 11 are A1 / B1.apprxeq.A2 / B2, the trailing is performed with respect to the vertical movement of the wheel. The pivot joint portion of the arm portion 11 and the lateral link portion 12 moves as if the trailing arm portion 11 and the lateral link portion 12 are integrated without swinging relatively relatively, and thus the conventional trapezoidal lower arm type The suspension locus can be almost the same as that of the multi-link.

FIG. 2 shows another example of the joint structure of the trailing arm portion 11 and the lateral link portion 12. Instead of the joint by the ball joint 13 of FIG. An example is shown. That is, the lateral link portion 12 with respect to the trailing arm portion 11
And the upper link 2 through the common shaft 15 such as a bolt
The bushing 14 is interposed between the outer ends of the lateral link portions 12 and the shaft 15 (the bushes are also interposed in the upper and lower shaft attaching portions of the upper link 3).
The bush 14 has a structure in which the lateral link portion 12 can be swung back and forth to some extent. Thus, the lateral link portion 12 with respect to the trailing arm portion 11 is
The upper link 2 and the upper link 2 are attached to one shaft in common to simplify the structure. In FIG. 2, the structure other than the above is the same as that of FIG.

[0017]

As described above, according to the present invention, in the trapezoidal lower arm type multi-link rear suspension,
The lateral link of the trapezoidal lower arm is configured separately from the trailing arm, and the outer end of the lateral link is connected to the trailing arm so as to be swingable in the front-rear direction. Can set the rigidity of the suspension in the front-rear direction almost irrespectively, and it is possible to achieve both maneuverability and ride comfort that were difficult with the conventional integrated trapezoidal lower arm. In addition, the trapezoidal lower arm consisting of the trailing arm section and the lateral link section is set at an acute angle between the vertical swing axis and the lateral link section, so that when the rearward force such as the braking force acts, the wheels move in the toe-in direction. The toe angle changes and the stability at the time of turning braking can be improved, and in combination with the simple structure and the good workability of outfitting, it can bring about a great effect in practical use.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a partial perspective view showing another example of the connecting structure of the trailing arm portion and the lateral link portion.

FIG. 3 is a plan view illustrating a change in the toe angle when a rearward force is applied to the wheel in the suspension according to the present invention.

FIG. 4 is a plan view showing an example of a conventional trapezoidal lower arm type multi-link rear suspension.

[Explanation of symbols]

 1 Trapezoidal lower arm 2 Upper link 3 Connecting rod 4 Housing 5 Wheel 11 Trailing arm part 11a Bushing 12 Lateral link part 12a Bushing 13 Ball joint 14 Bushing 15 Shaft

Claims (3)

[Claims] 1. In a trapezoidal lower arm type multi-link rear suspension of an automobile having a trapezoidal lower arm composed of a trailing arm portion and a lateral link portion, and an upper link, the lateral link portion of the trapezoidal lower arm is separated from the trailing arm portion. The trailing arm part is connected to the lower part of the housing, which is a wheel support, so that the trailing arm part is vertically swingable, and the front end part is attached to the vehicle body side member via a bush so as to be vertically swingable. A rear suspension for an automobile, characterized in that an outer end of a lateral link portion, the end portion of which is attached to a vehicle body side member via a bush, is joined to the trailing arm portion so as to be swingable in the front-rear direction. 2. The rear suspension of an automobile according to claim 1, wherein the trapezoidal lower arm including the trailing arm portion and the lateral link portion has an acute angle between the vertical swing shaft and the lateral link portion. Characteristic car rear suspension. 3. The rear suspension for a vehicle according to claim 1, wherein an outer end portion is vertically swingably coupled to an upper portion of the housing and an inner end portion is attached to a vehicle body side member via a bush. A rear suspension for an automobile, characterized in that a connecting rod for connecting the trapezoidal lower arm and the trailing arm portion of the trapezoidal lower arm to each other is provided.