JPS6248606B2 - - 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 extremely limited due to the need to install other suspension components such as stabilizers, so the swinging space for the triangular arm must be secured to avoid interference with other components. Therefore, there are many constraints and the degree of freedom in design is considerably restricted. Furthermore, while driving,
An impact load is applied to the wheels in the front and back direction due to the unevenness of the road surface, but in this case, the upper arm is pivoted at two points in the front and back, so it has high rigidity in the direction of this impact load, which prevents the impact from being applied to the vehicle body. This is easily transmitted and the ride quality worsens. This impact can be alleviated by making the elastic push of the two-point pivot part softer, but if it is made too soft, the camber change ( (in the forward direction) becomes large, resulting in a decrease in grip force and worsening of 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. Afterwards,
In order to enable smooth vertical movement of the wheel, it is essential to make the circumferential movement of this part 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.

(Objective of the present invention) An object of the present invention is to provide a lightweight and compact vehicle that can suppress the tendency to toe out due to vertical movement of the wheel, does not impair riding comfort, and also improves running stability. It is an object of the present invention to provide a rear suspension for an automobile that can be further improved.

(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 applies a force in the longitudinal 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 three lateral links extend 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. The wheel support member is connected to the vehicle body via the swing arm so as to be rotatably attached to the vehicle body through the swing arm, and the wheel support member is connected to the vehicle body through the swing arm so as to be rotatably mounted to the vehicle body. The attachment point of one lateral link is located above the wheel center, the attachment point of one other lateral link is below and in front of the wheel center, and the attachment point of the remaining lateral link is below and above the wheel center. The vehicle is characterized in that the lateral links that are arranged at the rear and are attached below and in front of the wheel center are shorter than the lateral links that are attached below and to the rear of the wheel center.

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. In the present invention, one of the three lateral links is located above the wheel center, and the other two
The book is attached to the wheel support member below the wheel center, and the two lateral links attached below are located at the front and rear of the wheel center, so toe changes due to wheel bumps and rebounds are caused by these two lateral links. It will be controlled by the lower two lateral links. Of the two lower lateral links, the front one is shorter than the rear one, so when the front lateral link swings in the vertical direction, the inward displacement of the outer end in the width direction of the rear lateral link The displacement of the outer edge of the wheel can be larger than the displacement of the outer end of the wheel, giving the wheel a slight toe-in change, or at least controlling the tendency to toe-out. 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, it is necessary to reduce the lateral rigidity of the swing arm so that it can flex laterally during bumps, rebounds, etc., or to attach the swing arm so that it can be displaced laterally relative to the vehicle body, or to The swing arm may be configured to allow lateral displacement of the wheel support member, such as by coupling the arm and the wheel support member such that relative displacement 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 above the wheel center, and the attachment points of the other two lateral links are above the wheel center. is positioned below the wheel center, and one of the lower two lateral links is positioned forward and the other behind the wheel center, so the toe change of the wheel is It is now regulated only by these two lower lateral links. Of the two lower lateral links, the one on the front side is made shorter than the one on the rear side, so it is possible to effectively suppress the tendency to toe out when the wheel bumps or rebounds.

(Description of Embodiments) Referring to FIGS. 1 to 5, a wheel 10 is rotatably supported by a wheel support member 12 and connected to a vehicle body 16 via a suspension device 14. The suspension device 14 includes a swing arm 18, a first lateral link 20, 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 rotatable around a horizontal axis in the lateral direction of the vehicle body by a rubber bush 39 integrated with the swing arm 18 on a bracket 29 provided on the main frame 28 of the vehicle body. The rear end is attached to the wheel support member 12.
It is fixed with bolts 30. 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 about 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 2
4 has rubber bushings 22a and 24 at one end, respectively.
It is rotatably attached to the wheel support member 12 via a to be rotatable about a horizontal axis in the longitudinal direction of the vehicle body, and is similarly attached to the rear subframe 32 on the vehicle body side via rubber bushings 22b and 24b about a horizontal axis in the longitudinal direction of the vehicle body. It is rotatably mounted on the The shock absorber 26 includes a coil spring 34 and a damper 36.
It extends in the vertical direction, the lower end is 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 the upper end is attached to the vehicle body 16 so as to be rotationally deflectable. . 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. The first lateral link also slopes slightly rearwardly and outwardly in the plane of FIG. 1, and slopes slightly outwardly and downwardly in the rear view of FIG. The first lateral link 20 is configured to have a shorter link length than the third lateral link 24.

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 center 40
is displaced along an arcuate trajectory centered on the bolt 38 at the front end of the swing arm 18.
In this case, since the wheel support member 12 is laterally supported by the three lateral links 20, 22, and 24, the lateral links 20, 22, and 24 also swing in the vertical direction, and their outer ends swing. Displaces laterally with movement. In the lateral link arrangement as in the illustrated embodiment, the first lateral link 20 is slanted laterally outwardly and slightly rearwardly and downwardly;
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 aligned along the curve 20c in FIG.
Although it is slightly displaced outward, since the link 20 has a rearward inclination, the amount of outward displacement is small.
The outer end of the second lateral link 22 is displaced inward as the wheel is displaced upward. Furthermore, although the outer end of the third lateral link 24 is displaced along the curve c in FIG. 2, the amount of displacement in the lateral direction of the vehicle body is extremely small. Since the outer end of the first lateral link 20 is located forward of the outer end of the third lateral link 24, there is almost no toe-in change as a whole, and the outer end of the second lateral link 22 is positioned upwardly relative to the other links. The camber angle will decrease. A downward displacement or rebound of the wheel results in a slight toe-in and a slight increase in camber angle. That is, in response to vertical displacement of the wheel, the toe angle changes as shown by curve a in FIG. 6, and the camber angle changes as shown in FIG. 6 c. Curve b in Figure 6 is Utility Model 56-62205
This figure shows the toe angle change in the No. 2 suspension, and from this figure, the effect of the excellent toe angle control in this example can be recognized. With such a change in the attitude of the wheel, the rubber bush 39 that attaches the swing arm 18 to the vehicle main frame 28 is displaced in the axial direction, so that the swing arm 1
8 to produce 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 make almost no toe angle change 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.

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.

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 of an embodiment of the suspension of the present invention, FIG. 2 is a rear view thereof, and FIG. 3 is a perspective view thereof.
FIG. 4 is a sectional view taken along the line AA in FIG. 1, FIG. 5 is a side view seen from the inside, and FIG. 6 is a chart showing changes in toe angle when the wheel is subjected to vertical force. 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)

[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 which is rotatable to the wheel support member and the other end to the vehicle body, respectively, through one pivoting means. and the wheel support member is connected to the vehicle body via the swing arm so as to allow lateral displacement with respect to the vehicle body, and one lateral tank is attached to the wheel support member. The point is located above the wheel center, the attachment point of one other lateral link is located below and in front of the wheel center, and the attachment point of the remaining lateral link is located below and behind the wheel center. A rear suspension for an automobile, characterized in that a lateral link installed below and in front of the wheel center is shorter than a lateral link installed below and behind the wheel center.