JPH055682B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rear suspension that rotatably supports a rear wheel of an automobile and also alleviates vibrations and shocks transmitted from the rear wheel.

(Prior Art) There are several types of automobile suspensions, one of which is a trailing arm suspension. Trailing arm type suspensions have advantages such as no change in tread or camber, a simple structure that takes up less space, and less shock when overcoming obstacles, and are mainly used for rear suspensions. It should be noted that trailing arm type suspensions are rarely used as front suspensions because the caster changes are large and the nose type during braking becomes large.

In a trailing arm type rear suspension, the lateral load on the tire is supported by the trailing arm, so it is necessary to increase the lateral rigidity of the trailing arm, so it is necessary to increase the arm span and strengthen the arm. etc., making the arm itself heavier cannot be avoided. An increase in arm weight leads to an increase in vehicle weight, which leads to problems such as deterioration in fuel efficiency and increase in manufacturing costs.

In order to improve such problems, for example,
As disclosed in No. 56-62205, a suspension structure in which a lightweight swing arm arranged in the longitudinal direction of the vehicle body is supported by two lateral links to reduce weight and improve lateral strength. is proposed.

Such a suspension has the advantage that the camber angle can be easily adjusted by adjusting the attachment positions of the inner ends of the upper lateral link and the lower lateral link to the vehicle body. However, when the wheel moves up and down with respect to the car body, that is, during bumps and rebounds, the center of the wheel is supported by the upper and lower lateral links, creating an almost circular arc. It moves up and down and also moves inward of the vehicle body (in the vehicle width direction, the direction in which the lateral link is provided to the wheel, that is, the left side for the right wheel and the right side for the left wheel is referred to as the inside of the vehicle body). When the wheel center moves inward to the vehicle body, the other end of the swing arm that supports the wheel rotates inward to the vehicle body.
Accordingly, the wheel points in the toe-out direction.

In this way, the above-mentioned suspension using one swing arm and two lateral links has the advantage of increasing lateral rigidity, reducing weight, and facilitating canvas control. However, there is a problem in that it is not possible to control the toe change of the tire during bumps and rebounds, and the wheel changes to the toe-out side during bumps and rebounds while driving, making the running of the vehicle unstable.

On the other hand, there are some systems in which the above-mentioned undesirable toe change is regulated by a combination of a trailing link and a plurality of lateral links (for example, ATZ72 (1970) 6 No. 200
~206 pages, JP-A-57-134309, JP-A-54-
(See Publication No. 153422, Italian Patent No. 510335).

(Problem to be Solved by the Invention) An object of the present invention is to prevent the above-mentioned rear wheel from undesirable toe change, etc. by attaching it to the vehicle body at one point on the base end so as to be able to swing up and down. A type of suspension that combines a swing arm placed in the longitudinal direction of the vehicle body with a rear wheel support fixedly supported at its tip to receive force and longitudinal force, and three lateral links placed in the lateral direction of the vehicle body. In adopting this suspension, we aimed to solve the following problems specific to this suspension.

In other words, in the above type of suspension,
The rear wheel support moves up and down while rotating back and forth around the base end of the swing arm, and as a result, the lateral link becomes strained. For this reason, if a bush is adopted as the connection part on the vehicle body side of the lateral link and its pivot axis is provided in the longitudinal direction of the vehicle body, the bush may become distorted due to the influence of the rotational movement of the rear wheel support in the longitudinal direction. invite. This is disadvantageous in terms of durability of the bushing, and in the case of rubber bushings, when the above-mentioned twist occurs, the rubber becomes compressed, so the spring constant of the bushing increases, and the rubber bushing loses its original strength. It is also disadvantageous in terms of exerting the vibration-proofing and sound-proofing effects that it has.

(Means for Solving the Problems) In order to solve such problems, the present invention provides a suspension having a swing arm and three lateral links as described above, in which the swing center axes of the lateral links are approximated. Focusing on the point located on the line connecting the car body side connection point of the late link and the car body side connection point of the swing arm, place the axis of the bush above on the side of the connection part between the swing arm and the car body in the longitudinal direction of the car body. This problem was solved by tilting it towards.

In other words, the means for solving the above problem consists of a rear wheel support that supports the rear wheel, a rear wheel support that is attached to the vehicle body at one point at the base end so as to be able to swing up and down, and a rear wheel support that is attached at the tip end to receive rotational force and longitudinal force from the rear wheel. A swing arm fixedly supports the rear wheel support and is arranged in the longitudinal direction of the vehicle body, each outer end is connected to three mutually distant points on the rear wheel support, and each inner end is connected to three mutually distant points on the vehicle body. three lateral links connected to each other and arranged in the lateral direction of the vehicle body with their central axes set to be substantially orthogonal to the swing arm, at least one of the three lateral links; The inner end connecting portion is composed of a bush, the axis of which makes an acute angle with the central axis of the lateral link, and is inclined toward the connecting portion between the swing arm and the vehicle body with respect to the longitudinal direction of the vehicle body. This is a rear suspension for automobiles that is characterized by:

(Function) In the case of the above rear suspension, by appropriately setting the mutual arrangement of the three lateral links, desired camber control can be achieved and undesirable toe changes can be prevented.

However, since the rear wheel support is fixedly supported at the tip of the swing arm, when the rear wheel bumps or rebounds, it rotates back and forth around the base end of the swing arm and moves up and down. Become. For this reason, the swing center axes of the three lateral links whose center axes are set to be approximately orthogonal to the swing arm are not perpendicular to the link center axes (therefore, the swing center axes are set to be approximately perpendicular to the swing arm). Approximately, the swing center axis is formed on a line connecting the inner end side connection point of the lateral link and the vehicle body side connection part at the base end of the swing arm.

On the other hand, in the case where the inner end side connection part of the lateral link is composed of a bush, the axis of the bush makes an acute angle with the link center axis, and the connection part between the swing arm and the car body in the longitudinal direction of the car body. Since it is inclined toward the side and approximates the pivot axis of the lateral link, even if the connection point on the rear wheel support side of the lateral link moves up and down and rotates back and forth, the bushing will not move. The twisting force acting on the is small.

(Embodiment) FIGS. 1 to 3 each show the overall configuration of a rear suspension of an automobile. A rear wheel 1 is rotatably supported by a rear wheel support 2. The rear wheel support 2 is supported by a side frame 7 and a cross member 8 of the vehicle body by one swing arm 3 and three lateral links 4, 5, and 6. Furthermore, a strut 10 is interposed between the rear wheel support 2 and the suspension tower 9.

The swing arm 3 is a thin plate that is arranged long in the front and back direction with the plate surface in the vertical direction, and the base end (front end)
It is connected to the side frame 7 at one point so as to be able to swing vertically, and the rear wheel support 2 is fixedly supported at the tip (rear end). The connecting portion 11 on the base end side of the swing arm 3 is constituted by a rubber bush. The shaft of this rubber button is attached to the side frame 7.
It is supported by a bracket 12 fixed to the lower surface of the.

On the other hand, the three lateral links are composed of a first lateral link 4, a second lateral link 5, arranged above and below, and a third lateral link 6, arranged on the front side. It is set to be substantially perpendicular to the arm 3 and is long in the lateral direction of the vehicle body. The first lateral link 4 provided on the upper side is connected at its outer side to the rear upper position of the rear wheel support 2 and at its inner end to the upper position of the cross member 8 so as to be vertically swingable. Second lateral link 5 provided on the lower side
The outer end is connected to a lower rear position of the rear wheel support 2, and the inner end is connected to a lower position of the cross member 8 so as to be vertically swingable. Furthermore, the third lateral link 6 provided on the front side is connected to the first and second lateral links.
A side frame 7 that is shorter than the lateral links 4 and 5 and whose outer end extends below the front of the rear wheel support 2 and whose inner end extends forward of the cross member 8.
The two brackets 13 are connected to each other.

In other words, the three lateral links 4 to 6 have their outer ends connected to three points on the rear wheel support 2 that form the vertices of a triangle separated from each other, and their inner ends connected to three points on the vehicle body that form the vertices of a triangle separated from each other. This means that

Then, the outer end side connecting portions 14 to 16 and the inner end side connecting portions 17 of the three lateral links 4 to 6
- 19 are all constituted by rubber bushings in this example. And each lateral link 4~
As shown in FIG. 4, the inner end connecting portions 17 to 19 of 6 have rubber bushings whose axes S ₁ to S ₃ make an acute angle with the central axes of the lateral links 4 to 6, and which extend in the longitudinal direction of the vehicle body. In contrast, it is inclined toward the connecting portion 11 between the swing arm 3 and the side frame 7. In other words, the axes S ₁ to _{S 3} of the rubber bush are inclined so that the base end of the swing arm is located on the outer side of the vehicle body than the opposite side.

On the other hand, the rubber bush constituting the proximal connecting portion 11 of the swing arm 3 also has its axis So inclined such that the inner side of the vehicle body is located closer to the lateral link than the outer side of the vehicle body.

Next, to explain the function of the above-mentioned rear suspension, first, when a braking force is applied to the rear wheel 1 while the car is running, the longitudinal force from the rear wheel 1 and the rotational force of the rear wheel support 2 are generated by the swing arm. 3 will take over. In addition, geometrical interference between the swing arm 3 and each lateral link 4 to 6 due to the vertical movement of the rear wheel 1,
This is absorbed by the deformation of the thin plate swing arm 3 and the deformation of each rubber bush.

Therefore, if we look at the camber change and toe change of the rear wheel 1 when the rear wheel 1 bumps or rebounds, the camber change is caused by the first lateral link 4 and the second or third lateral link 5 arranged above and below. 6 exhibits a parallel link-like function to prevent large ground camber changes, and the length of each lateral link 4 to 6 can be appropriately set to perform desired camber control.

On the other hand, regarding the toe change, in the case of this example,
The third lateral link 6 on the front side prevents the rear wheel 1 from changing to the toe-out side when bumping.

Here, if we consider the vertical movement of the rear wheel 1, this vertical movement involves the swing arm 3, the lateral links 4 to 6, and the connecting parts 11, 14 to 1.
9 is caused by the deformation of the rubber bushing, and it is recognized that the rear wheel 1 does not have a fixed pivot axis. This means that each lateral link 4-6
The same can be said about the pivoting center axes, and it is recognized that the direction of each pivoting center axis changes depending on the amount of vertical movement of the rear wheel 1.
In any case, the center axis of swing of each of the lateral links 4 to 6 is inclined toward the connecting portion 11 at the base end of the swing arm with respect to the longitudinal direction of the vehicle body.

Therefore, since the axes S ₁ to _{S 3} of the rubber bushings of the connecting portions 17 to 19 of the lateral links 4 to 6 are inclined toward the connecting portion 11 at the base end of the swing arm, the lateral links This means that the direction is similar to the direction of the pivot axes 4 to 6, so that the rubber bush does not twist much when the rear wheel 1 moves up and down.

The fact that there is little twisting of the rubber bushing due to the vertical movement of the rear wheel 1 means that the change in the spring constant of the rubber bushing due to this vertical movement is small (if there is twisting, the rubber becomes compressed and the spring constant This means that the rubber bushing's original vibration-proofing and sound-proofing effects are exhibited.

In the above embodiment, each connecting portion, 11, 14 to 19
Although it is made up of a rubber bush, part of it may be made up of a ball joint. Furthermore, it is not necessary to configure all of the inner end connecting portions 17 to 19 of the three lateral links 4 to 6 with rubber bushings and to tilt their axes. Only the connecting portion that receives a large load may be constructed of a rubber bushing, and its axis may be inclined.

In addition, in the above embodiment, the swing arm is used as a trailing arm, but the base end of the swing arm is connected to the vehicle body behind the rear wheel, and the front and rear positional relationship of each lateral link is reversed, so that the leading arm It may also be used as

In addition to being directly attached to the rear wheel support, the strut may also be attached to the swing arm or any of the three lateral links.

The rear wheel can also be used as a driving wheel with a structure in which the drive shaft passes through the rear wheel support.

(Effects of the Invention) According to the present invention, there is provided a swing arm in the longitudinal direction of the vehicle body that fixedly supports a rear wheel support at its tip, and three lateral links whose central axes are set to be substantially orthogonal to the swing arm. established,
The axis of the bush constituting the inner end side connection part of the lateral link is made to form an acute angle with the link center axis,
In addition, since it is tilted toward the connecting part between the swing arm and the vehicle body, it is possible to prevent the rear wheel from toeing out when bumping, and it also prevents the bushing from becoming twisted due to the vertical movement of the rear wheel. This will improve the durability of the bushing, and in the case of rubber bushings, the change in spring constant due to the above-mentioned twisting will be prevented, allowing the bushing to fully exhibit its vibration-proofing and sound-proofing properties.

[Brief explanation of the drawing]

The drawings show the rear suspension of an automobile; Fig. 1 is a plan view with the strut omitted, Fig. 2 is a rear view, Fig. 3 is a side view, and Fig. 4 is an enlarged plan view with the rear wheel support section simplified. It is. 1... Rear wheel, 2... Rear wheel support, 3... Swing arm, 4... First lateral link, 5... Second lateral link, 6... Third lateral link, 7... Side frame, 8 …
...Cross member, 11...Connection part, 14-19
...Connection part.

Claims (1)

[Scope of Claims] 1. A rear wheel support that supports the rear wheel, and a rear wheel support that is attached to the vehicle body at one point at the base end so as to be able to swing up and down, and that the rear wheel is attached to the tip end so as to receive rotational force and longitudinal force from the rear wheel. A swing arm fixedly supports a support and is arranged in the longitudinal direction of the vehicle body, each outer end is connected to three mutually distant points on the rear wheel support, and each inner end is connected to three mutually distant points on the vehicle body. , and three lateral links disposed in the lateral direction of the vehicle body, the center axis of which is set to be substantially orthogonal to the swing arm, and at least one of the three lateral links is an internal link. The end-side connecting portion is composed of a bush, the axis of which makes an acute angle with the center axis of the lateral link, and is inclined toward the connecting portion between the swing arm and the vehicle body with respect to the longitudinal direction of the vehicle body. An automobile rear suspension characterized by: