JPS6053409A - Rear suspension of car - Google Patents

Abstract

PURPOSE:To improve the traveling stability of a car by supporting a wheel bearing member with a swing arm extending along the car body and three lateral links extending across the car body and by forming the swing arm so as to allow the transverse displacement of the wheel bearing member against the car body. CONSTITUTION:A swing arm 18 is provided, which is plate-shaped (vertically wide) and extending along the car body and which is fixed, at one end, to the car body via a horizontal transverse shaft 38 in such a manner as to permit free rotation about this shaft and also fixed, at the other end, to a wheel bearing member with a bolt 30. Also the first through third lateral links 20, 22, 24 are provided, each of which is fixed, at one end, to the wheel bearing member 12 via a horizontal shaft extending practically along the car body in such a manner as to permit free rotation about this shaft and also fixed, at the other end, to the car body in the same manner, permitting free rotation. In this case, the fitting points of the three lateral links 20 through 24 to the wheel bearing member 12 are arranged so that they are not in a straight line in a vertical plane extending in the same direction as the car body line. Additionally, the one end of the swing arm 18 is fixed to the car body through a rubber bush 39 which can allow the axial displacement.

Description

[Detailed description of the invention] (Industrial application field) 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 is attached to the vehicle body so that its front end can swing vertically, and a hub support member that supports the wheel hub at the rear end of the trailing arm. 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, which increases the size of the trailing arm, which is disadvantageous in terms of weight.

A structure that solves these problems was developed in U.S. Pat.
It is proposed by No. 5. In this proposed structure,
The front end of a trailing arm that extends in the longitudinal direction of the vehicle body is swingably attached to the vehicle body, and the rear end supports a wheel hub. Each outer end of the link is coupled to a rotating member, and the inner end of the lateral link is rotatably coupled 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. 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.

(Object of the present invention) An object of the present invention is to provide a rear suspension for an automobile that can suppress the tendency to toe out due to vertical movement of a wheel, thereby further improving driving stability. .

(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. It includes a swing arm configured to be able to transmit transmission and three lateral links that extend in the lateral direction of the vehicle body independently of each other, one end of each lateral link is rotatably attached to the wheel support member, and the other end is rotatably attached to the vehicle body. 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 swing arm is configured to allow lateral displacement of the wheel support member with respect to the vehicle body. It is characterized by having been. In order to allow 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 transversely to the vehicle body. Further, as another aspect, the swing arm may be constructed of a temporary structure having a vertically elongated cross section whose height is larger than its thickness, or rubber may be interposed between the other end of the swing arm and the wheel support member. Good too.

According to this configuration of the present invention, the posture 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 vertical and vertical directions of each lateral link. By appropriately determining the longitudinal inclination angle, length, mounting position to the wheel support member, and lateral rigidity at the mounting position, lateral force and longitudinal force on the wheel can be minimized during wheel hump, rebound, etc. It becomes possible to control the toe change and camber angle change of the wheel to a desired tendency when the wheel is activated.

The swing arm only needs to have the strength and rigidity to transmit force in the longitudinal direction of the vehicle body and rotational force in the wheel rotation direction.
It is necessary not to impose constraints on the attitude control of the wheels by the three lateral links. Therefore, in the present invention, it is necessary to reduce the lateral rigidity of the swing arm so that the swing arm 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. , the swing arm is configured to allow lateral displacement of the wheel support member, such as by coupling the swing arm and the wheel support member for relative displacement.

(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 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, the change in attitude of the wheel becomes desirable when the wheel undergoes vertical motion or when lateral force or front-rear 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 FIG. 1, FIG. 2, FIG. 3, and FIG. has been done.

The suspension system @14 includes the swing arm 18, the first
It is composed of a lateral link 20, a second lateral link 22, a third lateral link 24, and a shock absorber 26. The swing arm 18 has a medium-wide plate shape vertically 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 by bolts 30. As shown in detail in FIG. 6, the front end of the swing arm 18 is provided with a rubber bush 39 consisting of an outer ff 139a, an inner cylinder 39b, and an inner cylindrical rubber 39c provided between the inner and outer cylinders. The front end of the swing arm 18 is attached to the bracket 29 of the vehicle main frame 28 by a bolt 38 inserted into the inner cylinder 39b of the rubber bush 39. 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, the rubber bushing 20 can be rotated around a horizontal axis in the longitudinal direction of the vehicle.
It is attached via b. Second lateral link 22
The third lateral link 24 has one end attached to the wheel support member 12 via rubber bushes 22a and 24a, respectively, so as to be rotatable around a horizontal axis in the longitudinal direction of the vehicle body.
The shock absorber 26, whose other end is similarly rotatably attached to the vehicle body side No. 10 frame 32 via rubber bushes 22b and 24b, is rotatable around a horizontal axis in the longitudinal direction of the vehicle body, and includes a coil spring 34 and a damper 36. It extends in the vertical direction, and its 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 its upper end is attached to the vehicle body 16 so as to be rotationally deflectable. The mounting positions of the lateral links 20, 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 18 swings around the bolt 38 for attaching its front end to the vehicle body.

Therefore, the wheel support member 12
It will be displaced along an arcuate trajectory centered on the bolt 38 at the front end of. 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 swing vertically, and their outer ends swing. Displaces laterally with movement. In the illustrated embodiment of the lateral link arrangement, the first lateral link 20 is slanted laterally outwardly and slightly posteriorly downward, and has the shortest length among the three lateral links. shellfish. 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. 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 equal to that of the first lateral link 24.
is larger than the amount of displacement at the outer end of. And the first and second
Since the outer ends of the lateral links 20, 22 are located further forward than the outer ends of the third lateral links 24, there is a slight toe-in tendency as a whole and the camber angle is reduced.

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. The curve in Figure 7 is from the 1980s.
This figure shows the toe angle change in the No. 05 suspension, and from this figure, the excellent effect of toe angle control in this example can be recognized. With such a change in the attitude of the wheel, the rubber bushing 39 that attaches the swing arm 1B to the vehicle main frame 28 is displaced in the axial direction as shown by the imaginary line in FIG. 6, and the swing arm 18 is Since it is a plate material having a longitudinally elongated cross-sectional shape whose height is larger than its thickness, the swing arm 18 is deflected by a lateral force, and therefore the swing arm 18 is caused to undergo a necessary amount of lateral displacement.

Note that when a lateral force is applied to the wheels such as when traveling on a curved road, the rubber bushes 20a, 22a,
24a is deflected, but by making the rigidity of these rubber bushings the same, almost no toe change occurs in response to lateral force, and the rigidity of these rubber bushings can be changed as necessary. This also makes it possible to produce a slight toe-in in response to an inward lateral force and a slight toe-out in response to an outward lateral force. Furthermore, with this arrangement, there is almost no change in the toe angle from front to back.

Note that the reaction force acting on the wheel 10 in the front and rear directions and opposing the rotational force 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 denoted by the same reference numerals. In this example, the arrangement of three lateral links 20, 22, and 24 is changed. Referring to FIG. 5, the mounting positions of the lateral links 20, 22, 24 on the wheel support member 12 are not aligned in a vertical plane in the longitudinal direction of the vehicle body, and the first lateral link 20 is A second lateral link 2 is located above and in front of the axle 40.
2 is located above and in front of the axle 40, and the third
The lateral links 24 are each attached at a position below and at the rear of the axle 40. Even with this arrangement, the effect is the same as the previous example.

FIG. 8 shows a further different embodiment of the present invention, in which the same parts as in the previous example are denoted 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 has its axis 39/ inclined laterally and rearward. In this example, when the swing arm 18 rebounds from the bump of the wheel 10, the deformation of the rubber bush 39 due to lateral displacement as shown by the imaginary line facilitates rearward movement of the wheel support member 12, allowing You can widen the scope.

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 drawings]

Figure 1 is a plan view showing the suspension of the present invention, Figure 2 is a plan view showing the suspension of the present invention.
The figure is an elevational view showing the suspension of the present invention, Figure 3 is a perspective view showing the suspension of the present invention, Figure 4 is a sectional view taken along line A-A in Figure 1, and Figure 5 is a cross-sectional view of another suspension. A detailed side view of the embodiment, FIG. 6 is a cross-sectional view showing the rubber butt 7 for attaching the swing arm, FIG. 7 is a chart showing the change in toe angle when the wheel receives vertical force, FIG. 8 is a plan view of yet another different embodiment. 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. Patent applicant: Toyo Kogyo Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4

Claims (3)

[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 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 is rotatably attached to the wheel support member, the other end is rotatably attached to the vehicle body, and the other end is rotatably attached to the vehicle body. The attachment points of the three lateral links to the support member are not aligned in a vertical plane in the longitudinal direction of the vehicle body, and the swing arm is configured to allow lateral displacement of the wheel support member with respect to the vehicle body. A rear suspension for an automobile characterized by comprising: (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 attached to the vehicle body with its axis oriented substantially transversely to the vehicle body. rear suspension. (3) In the above item 1 or 2, the swing arm is made of a plate material with a vertical cross section whose height is larger than its thickness, and the swing arm is configured to allow lateral displacement of the wheel support member by its lateral deflection. The rear suspension of a car.