JPS6248602B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to improvements in rear suspensions for automobiles.

(Prior Art) A system called a trailing arm type or a semi-trailing arm type has been known as an independent rear suspension for automobiles.
This rear suspension system has a trailing arm that extends in the longitudinal direction of the vehicle body and whose front end is attached to the vehicle body so that it can swing vertically.The rear end of this trailing arm has a hub support for supporting the wheel hub. The member is fixed. Further, a damper is arranged between the rear end of the trailing arm and the vehicle body above it. This type of rear suspension has a simple structure and is lightweight, but in order to sufficiently increase the lateral rigidity of the trailing arm, its cross-sectional shape must be made large and the attachment points to the vehicle body must be This requires a wide lateral spacing between the two, which increases the size of the trailing arm, which is disadvantageous in terms of weight.

A structure that solves these problems was developed in 1982.
Proposed by No. 62205. In this proposed structure, the front end of the trailing arm extending in the longitudinal direction of the vehicle body is swingably attached to the vehicle body, and the wheel hub is supported at the rear end. The outer ends of the two arranged lateral links are rotatably connected, and the inner ends of the lateral links are rotatably connected to the vehicle body. This type of rear suspension is advantageous in that the rigidity of the trailing arm does not need to be very high, but when the wheels move vertically relative to the vehicle body, the downward The wheels also tend to move in the toe-out direction during rebound, resulting in unstable steering such as oversteer while driving on a curved road. On the other hand, in West German Published Patent Application No. 2038880, a triangular upper arm disposed above and two lower arms arranged in parallel at the front and back disposed below are used to control the wheels. A configuration that supports this is disclosed. In this case, the attitude of the wheel is basically regulated by these three arms, so by selecting the position, arrangement, and length relationship of these arms, Even when the wheels move in the vertical direction relative to the vehicle body, the toe of the wheels can be set appropriately, and compared to the structure of the prior art described above, driving stability due to toe changes can be improved. It is. however,
The upper arm of this publication is constituted by a triangular arm having two pivot points to the vehicle body spaced apart in the longitudinal direction, and is particularly disadvantageous in terms of both space and riding comfort. In other words, it is necessary to secure a large space in order to allow the triangular upper arm to swing as the wheel moves up and down.
Generally, the space behind the wheels is very limited due to the need to install other suspension components such as stabilizers, so the swinging space of the triangular arm is limited to avoid interference with other parts. In order to ensure this, many constraints must be met, and the degree of design freedom is considerably restricted. Furthermore, while driving, impact loads are applied to the wheels in the front and rear directions due to the unevenness of the road surface. This causes shock to be easily transmitted to the vehicle body, worsening the ride comfort. It is possible to alleviate this impact by making the elastic bushing of the two-point pivot joint softer, but if it is made too soft, the camber of the wheel will be affected when lateral force is applied to the wheel during rotation. The change (in the positive direction) becomes large, resulting in a decrease in grip strength and poor steering stability.

Also, the rear end of the trailing arm in this publication is
For wheel support members that rotatably support wheels,
They are connected so that they can rotate freely. Then,
In order to enable smooth vertical movement of the wheel, it is essential that the circumferential motion of this part be smooth, and in order to ensure reliability, it is actually necessary to separately install parts such as large seal boots. As a result, there is a concern that the structure will become more complex.

(Object of the present invention) An object of the present invention is to be able to suppress the toe-out tendency that accompanies vertical movement of wheels, thereby further improving running stability and impairing riding comfort. The purpose of the present invention is to provide a lightweight and compact rear suspension for an automobile without any friction.

(Configuration of the present invention) In order to achieve the above object, the present invention is configured as follows. That is, the present invention extends in the longitudinal direction of the vehicle body, has one end attached to the vehicle body so as to be swingable in the vertical direction, supports a wheel support member at the other end, and transmits force in the longitudinal direction and rotational force in the wheel rotation direction to the wheel support member. three lateral links extending in the lateral direction of the vehicle body independently of each other; one end of each lateral link is connected to the wheel support member, and the other end is connected to the vehicle body through one pivoting means. The three lateral links are rotatably mounted and have a positional relationship in which the attachment points of the three lateral links to the wheel support member are not aligned in a vertical plane in the longitudinal direction of the vehicle body, and the wheel support member is lateral to the vehicle body. It is characterized in that it is connected to the vehicle body via the swing arm so as to allow directional displacement.

According to this configuration of the present invention, the attitude of the wheel support member and therefore the wheel is regulated only by the three lateral links, and the arrangement of the three lateral links, that is, the upper and lower positions of each lateral link. By appropriately determining the direction, longitudinal inclination angle, length, mounting position to the wheel support member, and lateral rigidity at the mounting position, lateral and longitudinal forces can be reduced when the wheel bumps, rebounds, and the wheel. It becomes possible to control the toe change and camber angle change of the wheel in a desired manner when the wheel is actuated.
The swing arm only needs to have the strength and rigidity to transmit the force in the longitudinal direction of the vehicle body and the rotational force in the wheel rotation direction, and it is necessary that it does not restrict the wheel attitude control by the three lateral links. There is. To achieve this, either the lateral stiffness of the swing arm is reduced so that the swing arm can flex laterally during bumps, rebounds, etc., or the swing arm and the wheel support member are They may be coupled in such a way that relative displacement in the horizontal or horizontal direction is possible.

(Effects of the Invention) According to the present invention, three lateral links extending in the lateral direction of the vehicle body are provided, and the attachment points of these lateral links to the vehicle body support member are not aligned in a straight line in the vertical plane in the longitudinal direction of the vehicle body. Because of the arrangement, the attitude of the wheel is regulated by these lateral links. Therefore, the swing arm can be made lightweight with a relatively small cross section, and the suspension can be constructed to be lightweight as a whole. In addition, by appropriately determining the arrangement of the three lateral links, it is possible to make the attitude change of the wheel desirable when the wheel moves in the vertical direction or when lateral force or longitudinal force is applied to the wheel. This makes it possible to effectively suppress the tendency of the wheels to toe out, for example, when bumping or rebounding. In this case, since each of the three lateral links is supported by the vehicle body via one pivoting means, the links can easily swing in all directions without deteriorating ride comfort.

(Description of Embodiments) Referring to FIGS. 1, 2, 3, and 4, a wheel 10 is rotatably supported by a wheel support member 12, and is connected to a vehicle body 1 via a suspension device 14.
6. Suspension device 14
is the swing arm 18, the first lateral link 2
0, a second lateral link 22, a third lateral link 24, and a shock absorber 26. The swing arm 18 has a vertically wide plate shape and extends in the longitudinal direction of the vehicle body. One end is attached to the vehicle body main frame 28 so as to be rotatable around a horizontal axis in the lateral direction of the vehicle body, and the other end is attached to the wheel support member 12 with bolts 30.
Fixed by First lateral link 20
extends substantially transversely to the vehicle body, and one end is attached to the wheel support member 12 via a rubber bushing 20a so as to be rotatable about a horizontal axis approximately in the longitudinal direction of the vehicle body;
The other end is attached to the main frame 28 of the vehicle body and is rotatable around a horizontal axis in the longitudinal direction of the vehicle body.
It is attached via 0b. The second lateral link 22 and the third lateral link 24 have one end rotatably attached to the wheel support member 12 via rubber bushings 22a and 24a, respectively, so as to be rotatable around a horizontal axis in the longitudinal direction of the vehicle body, and the other end of the second lateral link 22 and the third lateral link 24 are rotatable about a horizontal axis in the longitudinal direction of the vehicle body, respectively. 24b to the rear subframe 32 on the vehicle body side so as to be rotatable about a horizontal axis extending substantially in the longitudinal direction of the vehicle body. The shock absorber 26 includes a coil spring 34 and a damper 36, extends in the vertical direction, has a lower end attached to the wheel support member 12 so as to be rotatable around a horizontal axis in the lateral direction of the vehicle body, and has an upper end rotatably mounted to the vehicle body 16. installed in such a way that it is possible. Each lateral link 20,
The attachment positions of the wheels 22 and 24 on the wheel support member 12 are not in a straight line in a vertical plane in the longitudinal direction of the vehicle body.

When the wheel 10 receives a force in the vertical direction, the wheel 10 is displaced in the vertical direction, and the swing arm 1
8 swings around an axis 38 for attaching its front end to the vehicle body. In this case, the wheel support member 12
is supported laterally by the three lateral links 20, 22, and 24, so the lateral link 2
0, 22, and 24 also swing in the vertical direction, and their outer ends are displaced in the lateral direction as they swing. In the lateral link arrangement of the illustrated embodiment, the first lateral link 20 is slanted laterally outwardly and slightly rearwardly downward, and has the shortest length among the three lateral links. shellfish. 2nd lateral link 2
2 is slanted slightly forward and upwardly toward the outside in the lateral direction, and the third lateral link 24 is slanted slightly downwardly toward the outside in the lateral direction. With this arrangement, for example, if the wheel is displaced upward, the outer end of the first lateral link 20 will be slightly displaced outward, but since the link 20 has a rearward inclination, it will not move outward. The amount of displacement is small. The outer end of the second lateral link 22 is displaced inward as the wheel is displaced upward. Further, the outer end of the third lateral link 24 is displaced outward, and the amount of displacement is the same as that of the first lateral link.
This amount is larger than the amount of displacement of the outer end of the lateral link 20. And the first and second lateral links 20,
The outer end of the third lateral link 22 is located forward of the outer end of the third lateral link 24, resulting in a slight toe-in tendency as a whole and a decrease in the camber angle. A downward displacement or rebound of the wheel results in a slight toe-out and a slight increase in camber angle. That is, in response to vertical displacement of the wheel, a toe angle change occurs as shown by curve a in FIG. 6, and a camber angle change has a similar tendency. Curve b in FIG. 6 shows the toe angle change in the suspension of Utility Model Application No. 56-62205, and from this figure, the excellent effect of toe angle control in this embodiment can be recognized. Due to such a change in the attitude of the wheel, a necessary amount of lateral deflection occurs in the swing arm 18.

Note that when a lateral force is applied to the wheels such as when driving on a curved road, the rubber bushes 20a, 22a, 24a provided at the attachment portions between the lateral links 20, 22, 24 and the wheel support member 12 are bent. ,
By making the rigidity of these rubber bushings the same, it is possible to prevent almost any toe change from occurring in response to lateral force, and by changing the rigidity of these rubber bushings as necessary, it is possible to prevent inward lateral force from occurring. It is also possible to produce a slight toe-in against outward forces and a slight toe-out against outward lateral forces. Furthermore, with this arrangement, almost no toe angle change occurs with respect to longitudinal force.

Note that the reaction force acting against the longitudinal force and rotational force acting on the wheel 10 is shared by the swing arm 18. FIG. 5 shows another embodiment of the present invention, in which the same parts as in the previous example are designated by the same reference numerals. In this example, there are three lateral links 2
The arrangement of 0, 22, and 24 has been changed.

Referring to FIG. 5, each lateral link 20,
The mounting positions of the wheel support members 22 and 24 on the wheel support member 12 are in a positional relationship that is not in a straight line in the vertical plane in the longitudinal direction of the vehicle body, and the first lateral link 20
is located below and in front of the axle 40,
The second lateral link 22 is located above and in front of the axle 40, and the third lateral link 24
are attached at positions below and at the rear of the axle 40, respectively. Even with this arrangement, the operation is the same as the previous example.

The present invention is not limited to the arrangement of the embodiments described above, but by variously changing the arrangement of the lateral link, the position and rigidity of the attachment point to the wheel support member, the camber angle and toe angle of the wheel can be changed as desired. It is possible to make it a trend.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the suspension of the present invention, FIG. 2 is an elevational view showing the suspension of the present invention, FIG. 3 is a perspective view showing the suspension of the present invention, and FIG. 4 is a perspective view showing the suspension of the present invention. is a cross-sectional view taken along line A-A in Figure 1.
The figure is a detailed side view of the suspension of another embodiment.
FIG. 6 is a graph showing the change in toe angle when the wheel receives a force in the vertical direction. DESCRIPTION OF SYMBOLS 10...Wheel, 12...Wheel support member, 14...Suspension device, 18...Swing arm, 20...
First lateral link, 22... Second lateral link, 24... Third lateral link, 26... Shock absorber, 28... Vehicle main frame.

Claims (1)

[Claims] 1 Extends in the longitudinal direction of the vehicle body, has one end attached to the vehicle body so as to be swingable in the vertical direction, supports a wheel support member at the other end, and is configured to be capable of transmitting force in the longitudinal direction and rotational force in the wheel rotation direction to the wheel support member. and three lateral links extending independently from each other in the lateral direction of the vehicle body, one end of each lateral link being rotatable to the wheel support member and the other end being rotatable to the vehicle body through one pivoting means. The attachment points of the three lateral links to the wheel support member are not aligned in a straight line in a vertical plane in the longitudinal direction of the vehicle body, and the wheel support member has a positional relationship in which the attachment points of the three lateral links to the wheel support member are not aligned in a straight line in a vertical plane in the longitudinal direction of the vehicle body. A rear suspension for an automobile, characterized in that the rear suspension is connected to a vehicle body via the swing arm so as to allow the swing arm to rotate.