JPH03224810A - Trailing arm suspension - Google Patents

Abstract

PURPOSE:To improve operational stability by supporting a wheel on an accelerator carrier provided on the rear end of a trailing arm so as to vibrate freely, and by supporting the accelerator carrier on a car body through a camber control rod whose both ends are arranged on specified positions. CONSTITUTION:An accelerator carrier 4 is mounted by supporting a front and back pair of boss parts 6 on a support shaft 7 in a front-to-back direction, on the rear end of a trailing arm 1 by which a pair of boss parts 2 provided on the front end are supported on a car body side through a support shaft 3 so as to vibrate freely, while a wheel spindle 5 supporting a wheel W is integrated into the outside of the carrier 4, which is connected on the car body side through a camber control rod 9 extended in a car width direction, at the point higher than the boss part 6, and its connection point A on the side of the carrier 4 is set higher than a vibration center shaft line B of the rod 9, in such a way that the connection point A is always situated higher than the vibration center shaft line B during the vibration to the lower part of the rod 9.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a trailing arm type suspension for an automobile.

[Conventional technology]

A trailing arm type suspension is constructed by supporting wheels on a trailing arm attached to the vehicle body. Generally, a trailing arm is provided with a boss portion at its front end, and this boss portion is fitted and supported on a horizontal support shaft on the vehicle body side via a rubber bush. Therefore, the trailing arm is vertically swingable around the support shaft. Furthermore, the rubber bush reduces vibration transmission to the body.

[Problem to be solved by the invention]

However, such a trailing arm type suspension has the following problems. For example, in the case of a full trailing arm type, as shown in FIG. 5, when rolling occurs during turning, the camber of the wheels relative to the vehicle body does not change, and the roll angle of the vehicle body appears as a change in the camber relative to the ground. Therefore, during rolling, the tire surface collapses, resulting in poor tire grip, and the cornering force is reduced due to canvas last, which worsens steering stability. Furthermore, in the semi-trailing arm type, when the trailing arm swings up and down, there is a slight change in the camber relative to the vehicle body, so the change in the camber relative to the ground is slightly less than in the case of the full trailing arm type. However, in order to sufficiently change the camber relative to the vehicle body and prevent the tire surface from collapsing, it is necessary to increase the inclination angle of the trailing arm's swing axis (the angle indicated by α in Figure 3). . However, in such a case, the change in the toe-in direction of the wheels becomes too large when the trailing arm swings, resulting in another problem of poor straight-line stability when traveling on rough terrain. When the vehicle goes over a convex part of the road surface, the trailing arm swings as the wheels bounce, resulting in a toe change, but if this change is large when the vehicle is traveling straight, it causes a significant deterioration in running stability. The present invention was devised under the above circumstances, and prevents changes in the ground camber of the wheel when rolling occurs without deteriorating the straight-line stability when driving on rough terrain. An object of the present invention is to provide a trailing arm type suspension configured to improve steering stability during cornering.

[Means to solve the problem]

In order to solve the above problems, the present invention takes the following technical measures. That is, the trailing type suspension of the present invention is a suspension in which wheels are supported by a trailing arm via an axle carrier, and the axle carrier can be swung relative to the trailing arm around an axis in the longitudinal direction. On the other hand, a camber control rod extends above the trailing arm in the vehicle width direction, is connected to the vehicle body at one end, and the axle carrier at the other end, and can swing up and down about the connection point with the vehicle body. In addition, when the trailing arm swings in the direction of compressing the suspension spring, the camber control rod swings while displacing the connection point with the axle carrier inward in the vehicle width direction, thereby extending the suspension spring. The camber control rod is characterized in that when the trailing arm swings in the direction in which it moves, the camber control rod swings while displacing the connection point with the axle carrier outward in the vehicle width direction.

[Action of the invention]

An axle carrier that supports the wheels is attached to the trailing arm so as to be swingable about an axis in the longitudinal direction. In other words, the axle carrier is swingable in the camber direction. A camber control rod is placed above the trailing arm. The camber control rod extends in the vehicle width direction, has one end connected to the vehicle body, and the other end connected to the axle carrier, and is vertically swingable about the connection point with the vehicle body. When the trailing arm swings up and down, the camber control rod also swings up and down. When the camber control rod swings up and down, the connection point between the camber control rod and the axle carrier is displaced in the vehicle width direction. As described above, the axle carrier can swing relative to the trailing arm in the camber direction, and the camber control rod is connected to the axle carrier above the swing axis of the axle carrier. Therefore, when the camber control rond swings up and down, the axle carrier is pulled or pushed by the gamber control rond and swings in the camber direction. When the trailing arm swings in the direction in which the suspension spring is compressed, the connection point between the camber control rod and the axle carrier is displaced inward in the vehicle width direction as the camber control rod swings. In this case, the axle carrier is pulled by the camber control rod, and the axle carrier and the wheels supported by the axle carrier tilt with respect to the vehicle body in a so-called negative camber direction in which the upper portion of the axle carrier extends inward in the vehicle width direction. On the other hand, when the trailing arm swings in the direction in which the suspension spring extends, the connection point between the camber control rod and the axle carrier is displaced outward in the vehicle width direction. In this case, contrary to the above, the axle carrier and the wheels are tilted relative to the vehicle body in a so-called positive camber direction, in which the upper portions are tilted outward in the vehicle width direction. When rolling occurs during cornering, the trailing arm swings relative to the vehicle body on the outer wheel side, compressing the suspension spring. Can be changed in the camber direction. On the other hand, on the inner wheel side, the trailing arm swings relative to the vehicle body and the suspension spring expands, so that the camber of the wheel relative to the vehicle body changes in the positive camber direction. Therefore, when rolling occurs, the inclination of the trailing arm in the positive camber direction on the outer wheel side is offset by the relative inclination of the axle carrier and the wheel in the negative camber direction with respect to the trailing arm, thereby preventing a change in the ground camber of the wheel. Further, the inclination of the trailing arm in the negative camber direction on the inner ring side is offset by the inclination of the axle carrier and the wheel in the positive camber direction, thereby preventing a change in the ground camber of the wheel.

【Effect of the invention】

As described above, the present invention can prevent changes in the ground camber of the wheels when rolling occurs during cornering, and therefore, unlike conventional trailing arm suspensions, the tire surface collapses during cornering and the running stability deteriorates. There is no such problem, and the steering stability can be improved. Furthermore, since the swing axis of the trailing arm is not tilted to change the camber relative to the vehicle body when the trailing arm swings, a problem arises in which straight-line stability is impaired when driving on rough terrain. Nor.

[Explanation of Examples]

Embodiments of the present invention will be described below with reference to the drawings. In this example, an example in which the present invention is applied to a semi-trailing arm type suspension will be described. As shown in FIGS. 1 and 3, a pair of boss portions 2, 2 are provided at the front end of the trailing arm 1. The trailing arm 1 is swingably attached to the vehicle body by having the boss portion 2 supported by a support shaft 3 on the vehicle body side via a rubber bush (as shown). Further, a suspension spring 13 is attached to the trailing arm 1, the upper end of which is connected to the vehicle body side, and the lower end of which is connected to the trailing arm 1. An axle carrier 4 that supports wheels W is attached to the rear end of the trailing arm 1. A wheel spindle 5 that supports a wheel W via a bearing (as shown) or the like is integrally provided on the outer side of the axle carrier 4. Also, axle carrier 4
A pair of front and rear boss portions 6, 6 arranged on the same axis in the front and back direction are provided on the inner side of the head. To attach the axle carrier 4 to the trailing arm 1, attach the pair of boss parts 6, 6 to the trailing arm 1.
This is done by fitting and supporting a support shaft 7 in the front-rear direction provided in the front and back via a rubber bush (as shown). The support shaft 7 is inserted into and supported by a boss portion 8 provided at the rear end of the trailing arm 1 via a rubber bush (as shown). Further, as shown in FIGS. 1 and 2, the axle carrier 4 is connected to a camber control rod 9 that extends above the trailing arm 1 in the vehicle width direction. The camber control rod 9 has an inner end boss 10 supported via a rubber bush (as shown) on a longitudinal support shaft 11 attached to the vehicle body, and an outer end supported via a ball joint 12. and is connected to the axle carrier 4. The camber control rod 9 can swing up and down about the support shaft 11, and when swinging, the connection point A between the camber control rod 9 and the axle carrier 4 is aligned with the support shaft 11 (swing center axis B). ) Draw an arc locus centered on Therefore, when the camber control rod 9 swings up and down, the connection point A is displaced in the vehicle width direction. At this time, the axle carrier 4 is pulled inward in the vehicle width direction or pushed outward in the vehicle width direction by the camber control rod 9 to swing around the support shaft 7 . As a result, the wheels W supported by the axle carrier 4 are tilted in the camber direction (in the direction of arrow N or P in FIG. 2). In the case of this example, as shown in FIGS. 1 and 2, the connection point A is located above the swing center axis B of the camber control rod 9, and the camber control rod 9 is tilted in the vertical direction. ing. Furthermore, even when the camber control rod 9 swings downward, the connection point A is always positioned above the swing center axis B. As a result, when the camber control rod 9 swings, the displacement direction in the vehicle width direction of the connecting point A, which moves on an arc centered on the swing axis, becomes inward in the vehicle width direction when the camber control rod 9 swings upward, and downwards. When the vehicle is swung, the vehicle is oriented outward in the width direction of the vehicle. When the connection point A is displaced inward in the vehicle width direction, the axle carrier 4 is pulled by the camber control rod 9 and is caused to swing relative to the trailing arm 1 in the direction of arrow N in FIG. At this time, the wheel W changes its camber relative to the vehicle body in a so-called negative camber direction, in which the upper part of the wheel W tilts inward. Additionally, if the connection point A is displaced outward in the vehicle width direction, the axle carrier 4
is pushed into the camber control rod 9 and is caused to swing relative to the trailing arm 1 in the direction of arrow P in FIG. Thereby, the wheel W changes its camber relative to the vehicle body in a so-called positive camber direction, in which the upper part of the wheel W tilts outward. In addition, camber control rod! H;l: As shown in the figure, it is desirable to arrange the inner end boss portion 10 so that it is located above the swing axis of the trailing arm 1. By doing so, the swing locus of the trailing arm 1 and the swing locus of the camber control rod 9 can be matched, and the camber control by the camber control rod 9 can be performed more smoothly. Further, the longitudinal position of the connection point A is made to substantially coincide with the longitudinal center of the boss portion 8 of the trailing arm 1. In the trailing arm suspension of the present invention configured as described above, the ground camber of the wheel W can be kept constant even when rolling occurs. When rolling occurs during turning, the trailing arm 1 on the outer wheel side swings relative to the vehicle body in a direction approaching the vehicle body (in a direction that compresses the suspension spring 13). in this case,
The camber control rod 9 is connected to the axle carrier 4
Displace the connecting point A inward in the vehicle width direction, and move the axle carrier 4 in the negative camber direction (direction of arrow N in Figure 2).
The trailing arm 1 is relatively swung in the same direction as the trailing arm 1. Therefore, the camber of the wheel W relative to the vehicle body can be changed in the negative camber direction by the rocking of the axle carrier 4, so even if the trailing arm 1 is tilted in the positive camber direction due to rolling, as shown in FIG. , the ground camber of the wheels can be kept constant. In addition, on the inner wheel side, the trailing arm 1 is moved away from the vehicle body (suspension spring 13
relative swing in the direction of elongation). At this time, the camber control rod 9 displaces the connection point A with the axle carrier 4 outward in the vehicle width direction, swings the axle carrier 4 in the positive camber direction (direction of arrow P in FIG. 2), and performs a trailing motion. It relatively swings in the same direction as arm 1. Therefore, since the camber of the wheel W relative to the vehicle body can be changed in the positive camber direction, even if the trailing arm 1 is tilted in the negative camber direction, the fourth
As shown in the figure, changes in the ground camber of the wheels can be prevented. Therefore, it is possible to prevent the tire surface from collapsing due to rolling during turning, and it is possible to improve steering stability. Further, in this example, the front and rear boss portions 6, 6 of the axle carrier 4 are provided such that the front boss portion 6 is located near the center of the wheel in the front-rear direction. As a result, most of the lateral force that the wheels W receive from the road surface when turning or the like acts on the front boss portion 6 of the front and rear boss portions 6.6. Furthermore, the spring constant of the rubber bushing installed inside the front boss part 6 is
The spring constant is smaller than that of the rubber bushing inside. Therefore, when a lateral force is applied to the wheel during turning, etc., the amount of deflection of the rubber bushings in each of the boss sections 6 and 6, which are deformed by the lateral force, is greater on the front boss section 6 side. growing. When viewed from the outer wheel side during a turn, the above-mentioned lateral force acts as a force Y directed inward in the vehicle width direction, as shown in Fig. 3, so the amount of deflection of the rubber bushing of the front boss portion 6 increases. This means that the axle carrier 4 is moved in the toe-in direction (arrow 1 direction). Therefore, even if the trailing arm 1 is moved in the toe-out direction (in the direction of arrow O) due to the deflection of the rubber bush in the boss portion 2 due to the lateral force, the displacement in the toe-out direction is compensated for in the toe-in direction of the axle carrier 4. As a result, displacement of the wheel W in one direction can be prevented. In addition, in the case of the inner wheel, the above-mentioned lateral force acts on the wheel as an outward force in the vehicle width direction, but the movement of the trailing arm 1 in the toe-in direction is offset by the displacement of the axle carrier 4 in the toe-out direction. Thus, the toe change of the wheel W can be prevented. In other words, it is possible to prevent compliance 6 steer when turning, etc., and it is expected that the steering stability will be improved thereby. Further, the center axis of rotation of the wheel W when the axle carrier 4 is displaced in one direction is the connection point A (ball joint 12
) and the approximate center point between the boss portions 6.6 of the axle carrier 4 (see FIG. 2). In this example,
As shown in FIG. 2, the connection point B is located inward in the vehicle width direction from the boss portion 6, and the virtual kingpin axis SA
The ground contact point S of the tire is offset outward from the ground contact center point T of the tire, which is a so-called negative offset setting. Therefore, when a rearward force X (see Figure 3) is applied to the tire during braking, etc., normally,
The above force bends the rubber bushing of the trailing arm and displaces the trailing arm and tire in the 0 direction (toe-out) in FIG. 3, but in this example,
Due to the above negative offset, the axle carrier 4
Then, the tire is displaced in the direction 1 (toe-in) in FIG. 3, and as a result, toe change of the tire can be prevented, so running stability is further enhanced. By the way, the scope of the present invention is not limited to the above-described embodiments. For example, although the above-mentioned embodiment shows an example in which the present invention is applied to a semi-trailing arm type suspension, the present invention can also be applied to a full trailing arm type suspension without any problems. Further, in the above embodiment, the axle carrier and the canopy control rond are connected through a ball joint, but they may be connected through an elastic body.

[Brief explanation of drawings]

FIG. 1 is a perspective view schematically showing a suspension according to an embodiment of the present invention, FIG. 2 is a rear view of a suspension according to an embodiment, and FIG. 3 is a plan view of FIG. FIG. 4 is a diagram schematically showing the state of the suspension according to the embodiment during turning, and FIG. 5 is a diagram schematically showing the state of the conventional suspension during turning. 1... Trailing arm, 4...Axle carrier, 9...Canister control rond.

Claims (1)

[Claims] (1) A suspension in which a wheel is supported on a trailing arm via an axle carrier, in which the axle carrier is attached to the trailing arm so as to be able to swing relative to it around an axis in the longitudinal direction; A camber control rod is provided that extends upward in the vehicle width direction, is connected to the vehicle body at one end and to the axle carrier at the other end, and is capable of vertically swinging around the connection point with the vehicle body, and is equipped with a suspension spring. When the trailing arm swings in the direction of compression, the camber control rod swings while displacing the connection point with the axle carrier inward in the vehicle width direction, causing the trailing arm to swing in the direction of extending the suspension spring. The trailing arm type suspension is characterized in that the camber control rod sometimes swings while displacing the connection point with the axle carrier outward in the vehicle width direction.