JPS6248603B2 - - 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 if the wheels move vertically relative to the vehicle body, they will Even when the vehicle moves toward the vehicle or rebounds, the wheels tend to move in the toe-out direction, 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 therefore disadvantageous both in terms of 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. Many restrictions must be met in order to ensure
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 part softer, but if it is made too soft, the camber of the wheel will change when lateral force is applied to the wheel during turning. (in the forward direction) becomes large, resulting in a decrease in grip force 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 front-rear direction of the vehicle body, has one end attached to the vehicle body so as to be swingable in the vertical direction, and has the other end fixed to a wheel support member, and applies a force in the front-rear direction and a rotational force in the wheel rotation direction to the wheel support member. The swing arm is configured to be capable of transmission, and has 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 swing arm is rotatably attached to the wheel support member, and 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 swing arm is rotatably attached to the wheel support member relative to the vehicle body. It is characterized by being constructed from a plate material with a vertically long cross section, the height of which is greater than the thickness, so as to allow for lateral displacement. In order to allow more lateral displacement of the wheel support member, the one end of the swing arm may be attached to the vehicle body via an axially displaceable rubber bushing, and the axis of the rubber bushing may be oriented substantially laterally with respect to the vehicle body.

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 position of each lateral link. By appropriately determining the inclination angle and length in the vertical and longitudinal directions, the mounting position to the wheel support member, and the lateral rigidity at the mounting position, it is possible to prevent lateral forces and longitudinal forces on the wheel during bumps, rebounds, etc. It becomes possible to control the toe change and camber angle change of the wheel in a desired manner when a force is applied. 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. Therefore, in the present invention, the lateral stiffness of the swing arm is lowered to reduce bumps,
The swing arm is made to be able to deflect laterally during rebound, etc., or the swing arm is attached to the vehicle body so that it can be displaced laterally, or the swing arm and the wheel support member are coupled to allow relative displacement. The swing arm is configured to allow lateral displacement of the wheel support member by the following method.

(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 this arrangement, the attitude of the wheel is regulated only by these lateral links. Therefore, the swing arm can be lightweight and have a relatively small cross section.
The suspension as a whole can be made lightweight.
In addition, by appropriately determining the arrangement of the three lateral links, the attitude change of the wheel becomes 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 during bumps or rebounds, for example. Further, since the swing arm is configured to allow lateral displacement of the wheel support member with respect to the vehicle body, the attitude control of the wheel by the lateral link is not restricted by the swing arm.

(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, and its front end is attached to the vehicle main frame 28 so as to be rotatable around a horizontal axis in the lateral direction of the vehicle body, and its rear end is attached to the wheel support member 12 with bolts 30.
Fixed by As shown in detail in FIG. 6, a rubber bushing 39 is provided at the front end of the swing arm 18 and includes an outer cylinder 39a, an inner cylinder 39b, and an inner cylindrical rubber 39c provided between the inner and outer cylinders. The front end of the spink arm 18 is attached to the bracket 29 of the vehicle main frame 28 by a bolt 38 inserted into the inner cylinder 39b. The rubber bushing 39 can be displaced in the axial direction, as shown in phantom lines in FIG. 6, and the axis is arranged in the lateral direction of the vehicle body. The first lateral link 20 extends substantially transversely to the vehicle body, and has one end attached to the wheel support member 12 via a rubber bushing 20a so as to be rotatable around a horizontal axis in the longitudinal direction of the vehicle body, and the other end to the vehicle main frame 28. Similarly, it is mounted via a rubber bushing 20b so as to be rotatable around a horizontal axis extending substantially in the longitudinal direction of the vehicle body. Second lateral link 22 and third lateral link 24
have rubber bushings 22a and 24a at one end, respectively.
The other end is attached to the wheel support member 12 via rubber bushings 22b and 24b so as to be rotatable around a horizontal axis in the longitudinal direction of the vehicle body, and the other end is attached to the rear subframe 32 on the vehicle body side via rubber bushings 22b and 24b. It is mounted so that it can rotate around its axis. 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. The mounting positions of the respective lateral links 20, 22, and 24 on the wheel support member 12 are in a positional relationship that is not in a straight line within 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 is a bolt 38 for attaching the front end to the vehicle body
sway around. Therefore, the wheel support member 12 is attached to the bolt 38 at the front end of the swing arm 18.
It will be displaced along an arcuate trajectory centered on . In this case, since the wheel support member 12 is laterally supported by the three lateral links 20, 22, 24, the lateral links 20, 22, 24
also swings vertically, and its outer end is displaced laterally as it swings. In a lateral link arrangement such as the illustrated embodiment, the first lateral link 20
is slanted laterally outward and slightly posteriorly downward, and its length is the shortest among the three lateral links. The second lateral link 22 is laterally outwardly inclined slightly forward and upwardly, and the third lateral link 24 is laterally outwardly inclined slightly downwardly. 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. Second lateral link 22
The outer end of the wheel is displaced inwardly 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 greater than the amount of displacement of the outer end of the first lateral link 20. and,
Since the outer ends of the first and second lateral links 20 and 22 are located forward of the outer end of the third lateral link 24, a slight toe-in tendency occurs as a whole, and the camber angle decreases. 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. 7, and a camber angle change has a similar tendency. Curve b in Figure 7 shows the toe angle change in the suspension of Utility Model Application No. 56-62205. From this figure,
The excellent toe angle control effect in this example is recognized. Along with this change in wheel posture,
The rubber bush 39 that attaches the swing arm 18 to the vehicle main frame 28 has an axial deviation as shown by the imaginary line in FIG. The shape of the plate material causes lateral flexure, thus causing the swing arm 18 to undergo the required amount of lateral displacement.

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 20, 2.
2 and 24 have been changed. Referring to FIG. 5, each lateral link 20, 22, 24
The mounting position on the wheel support member 12 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 attached to the axle shaft 40.
The second lateral link 22 is located above and in front of the axle 40, and the third lateral link 24 is located above and in front of the axle 40.
They are respectively installed below and at the rear of the vehicle. Even with this arrangement, the operation is similar to that of the previous example.

FIG. 8 shows a still further 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, the rubber bush 39 for attaching the front end of the swing arm 18 to the bracket 29 of the vehicle main frame 28 is inclined rearward with its axis 39l facing in the lateral direction. In this example, the swing arm 18 is
0 bump, the deformation of the rubber bushing 39 due to lateral displacement as shown by the imaginary line during rebound is
The rearward movement of the wheel support member 12 is facilitated, and the permissible range can be widened.

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 invention, Fig. 3 is a perspective view showing the suspension of the invention, and Fig. 4 is a perspective view showing the suspension of the invention. The figure is a sectional view taken along the line A-A in Fig. 1, Fig. 5 is a detailed side view of another embodiment, Fig. 6 is a sectional view showing a rubber button for attaching the swing arm, and Fig. 7 is a sectional view of the wheel in the vertical direction. FIG. 8 is a plan view of yet another different embodiment. Explanation 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, 2
6...Shock absorber, 28...Vehicle main frame.

Claims (1)

[Scope of Claims] 1. Extends in the longitudinal direction of the vehicle body, one end is attached to the vehicle body so as to be swingable in the vertical direction, and the other end is fixed to a wheel support member, so that it does not apply force in the longitudinal direction to the wheel support member and rotation in the wheel rotation direction. A swing arm configured to be able to transmit force, and three lateral links extending in the lateral direction of the vehicle body independently of each other, one end of each lateral link being pivotally connected to the wheel support member, and the other end being pivotally connected to the vehicle body. The swing arm is rotatably attached to the wheel support member and has a positional relationship in which attachment points of the three lateral links to the wheel support member are not lined up in a vertical plane in the longitudinal direction of the vehicle body, and the swing arm A rear suspension for an automobile, characterized in that it is constructed from a plate material having a longitudinally long cross-section, the height of which is greater than the thickness thereof, so as to permit lateral displacement of the member relative to the vehicle body. 2. In the above item 1, the one end of the swing arm is attached to the vehicle body via a rubber bushing that is displaceable in the axial direction, and the rubber bushing is arranged so that its axis is oriented substantially transversely to the vehicle body. Shion.