JP6719163B2 - Rear suspension - Google Patents

Description

The present invention relates to a rear suspension of a vehicle such as an automobile.

As a specific example of the rear suspension, there is one disclosed in Patent Document 1.
The rear suspension described in the document is a type in which a pair of left and right trailing arms are connected by a torsion beam. A rubber bush, which is rotatably supported by a bracket on the vehicle body side, is attached to the front part of each trailing arm.The center axis of this rubber bush is more toward the rear of the vehicle on the outside than the inside in the vehicle width direction. It is set to be tilted so that it is located.
With such a configuration, it is possible to utilize the lateral force that acts on the outer wheel when the vehicle turns to make the steering characteristic understeer. Unlike the above-mentioned document, when the central axis of the rubber bush is set so as not to be inclined with respect to the vehicle width direction, oversteer occurs, which is not preferable for improving the steering stability, According to this, it is possible to eliminate such a thing.

However, in the above-mentioned conventional technique, there is still room for improvement as described below.

That is, when the vehicle turns, a lateral force is generated that tends to displace the rear wheel on the outer wheel side inward in the vehicle width direction. Therefore, in Patent Document 1, in order to prevent the front portion of the trailing arm and the rubber bush from being displaced inward in the vehicle width direction by this lateral force, a ring-shaped ring is formed at the end of the elastic body of the rubber bush. A stopper portion is provided, and the stopper portion is always brought into contact with the vehicle body side bracket.
However, according to such a configuration, if the stopper portion of the rubber bush is hard, the flexibility of the rubber bush in the vehicle width direction is impaired. Further, the displacement of the front part of the trailing arm inward in the vehicle width direction may be excessively restricted, and good understeer characteristics may not be obtained. In the above-mentioned type of rear suspension, the larger the amount of displacement of the front part of the trailing arm inward in the vehicle width direction, the stronger the understeer characteristic, but the stopper part of the rubber bush always contacts the vehicle body side bracket. If they are in contact with each other, it becomes difficult to appropriately displace the front portion of the trailing arm inward in the vehicle width direction when the stopper portion is hard.
On the other hand, if the stopper portion is soft, the understeer characteristic can be obtained, but the lateral rigidity of the suspension becomes poor and the maneuverability deteriorates.
Although such a problem can be solved to some extent by making the material of the stopper part an appropriate hardness, it is difficult to set such a hardness in practice, and the above-mentioned problems are appropriately solved. Is difficult to do.

JP, 2007-137087, A

The present invention has been devised under the circumstances as described above, and it is an object of the present invention to provide a rear suspension capable of suitably setting understeer, improving maneuverability and riding comfort. , That is the subject.

In order to solve the above problems, the present invention takes the following technical means.

A rear suspension provided by the present invention is a pair of left and right trailing arms that are located at intervals in the vehicle width direction and are connected to each other via a torsion beam, and that have rear wheels attached to their rear portions. A pair of left and right rubber bushes joined to the front parts of the pair of trailing arms and attached to the vehicle body side bracket, and a pair of left and right rubber bushes provided at the end surfaces on the inner side in the vehicle width direction of the rubber bushes The rear suspension is provided with a protrusion projecting toward one side, and the center axis of each of the rubber bushes is inclined so that the outer side is positioned rearward of the vehicle rather than the inner side in the vehicle width direction. In the normal state in which the trailing arms are not bound or rebounded, the protrusions of the rubber bushes are located in the upper half of the end face portion on the vehicle rear side, and Each rubber bush has an arc shape extending in the circumferential direction of the rubber bush in a side view, and is provided so as to form a gap between the rubber bush and the vehicle body side bracket in the vehicle width direction. with the when the trailing arm is bound while receiving a lateral force in the vehicle width direction inner side is, the are a vehicle body side bracket on the contact configuration, provided the said end surface of each rubber bushing And one of the pair of trailing arms is used as a rubber bush of the other trailing arm by reversing one rubber bush of the other trailing arm, the additional protrusion is the protruding portion of the rubber bush of the other trailing arm. It is characterized by further including a section .

With such a configuration, the following effects can be obtained.
That is, when the trailing arm bounces while the vehicle turns and the rear wheel on the outer wheel side receives the lateral force inward in the vehicle width direction, the protrusion of the rubber bush and the bracket on the vehicle body side are initially in contact with each other. Since there is a gap between them and they are not in contact with each other, the front part of the trailing arm can be smoothly displaced inward in the vehicle width direction. On the other hand, since the protrusion of the rubber bush comes into contact with the bracket on the vehicle body side after that, it is possible to appropriately restrain the front portion of the trailing arm from being displaced inward in the vehicle width direction thereafter. ..
Therefore, according to the present invention, when the vehicle turns, the front portion of the trailing arm can be displaced inward by an appropriate amount in the vehicle width direction, and the steering characteristic can be made good understeer. In addition, the flexibility of the rubber bush in the vehicle width direction is not significantly impaired, and the lateral rigidity of the rear suspension is not significantly reduced, which improves ride comfort and maneuverability. It is possible.
Furthermore, since the protrusion is non-ring-shaped, when assembling the rubber bush to the trailing arm by using a press-fitting method, for example, the portion of the end surface of the rubber bush where the protrusion is not provided is It is possible to pressurize and properly perform the assembling work. Since the stopper portion of Patent Document 1 is ring-shaped, it is difficult to handle the rubber bush as described above in the present invention.

Other features and advantages of the present invention will become more apparent from the following description of the embodiments of the invention with reference to the accompanying drawings.

It is a principal part schematic plan view which shows an example of the rear suspension which concerns on this invention. (A) is a plane sectional view of a mounting portion of a right side rubber bush of the rear suspension shown in FIG. 1, and (b) is a sectional view taken along line IIb-IIb of (a). FIG. 1A is a side view schematically showing a normal state of the rear suspension shown in FIG. 1, and FIG. 1B is a plan view of a main part of a right rubber bush mounting portion in a state shown in FIG. Is. 1A is a side view schematically showing a state where a trailing arm of the rear suspension shown in FIG. 1 is bound, and FIG. 1B is a side view of a right rubber bush mounting portion in a state shown in FIG. FIG.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.
In the figure, arrow Fr indicates the front of the vehicle, arrow Up indicates the upper side in the vehicle height direction, and arrow W indicates the vehicle width direction.

The rear suspension S shown in FIG. 1 is a pair of left and right trailing arms 1 which are spaced apart in the vehicle width direction and have rear wheels 6 attached to their rear portions, and the pair of trailing arms 1 in the vehicle longitudinal direction. A torsion beam 2 for connecting the middle portions and a pair of rubber bushes 3 attached to the front portions of the pair of trailing arms 1 are provided.

The central axis L3 of each rubber bush 3 is set to be inclined at an appropriate angle α with respect to the vehicle width direction so that the outer side is positioned rearward of the vehicle rather than the inner side in the vehicle width direction. As described in the background art section, the steering characteristic of the rear suspension S can be made understeer by such setting.

Each rubber bush 3 is a portion that serves as a rotation fulcrum in the vertical height direction of each trailing arm 1, and as shown in FIG. 2, the outer cylinder 30 joined to the front portion of the trailing arm 1 and the vehicle body side bracket. 4, an inner cylinder 31 attached by using bolts and nuts 48, 49, an elastic body 32 interposed between the inner cylinder 31 and the outer cylinder 30, and a protrusion 33.

The protruding portion 33 is a portion for restricting the front portion of the trailing arm 1 from being displaced inward in the vehicle width direction when the vehicle turns, and is an end surface portion of the rubber bush 3 on the inner side in the vehicle width direction. 35, and projects toward the inner side in the vehicle width direction. However, the protrusion 33 is provided so as to form a gap 34 having an appropriate width s1 (for example, about 0.7 mm) between the protrusion 33 and the side wall 40 of the vehicle body side bracket 4. Preferably, the protrusion 33 is formed integrally with the elastic body 32, and is provided so that the back side is supported by the flange portion 30 a of the outer cylinder 30.

As well shown in FIG. 2B, the protrusion 33 has a non-ring shape provided in a part of the rubber bush 3 in the circumferential direction. The position of the protruding portion 33 is, for example, on the vehicle rear side (rear side of the center line Lb) of the end surface portion 35 of the rubber bush 3 and on the upper half (upper side of the center line Lc) .

FIG. 2B shows a configuration in which an additional protrusion 33 ′ different from the protrusion 33 is further provided. When the rubber bush 3 is inverted and attached to the trailing arm 1 on the side opposite to the trailing arm 1 shown in FIG. 2, this additional protrusion 33 ′ is attached to the trailing arm 1 on the opposite side. This is a portion that becomes the protrusion 33 for movement restriction. With such a configuration, the rubber bush 3 having the same shape can be used for both the right and left trailing arms 1, and it is necessary to use two types of rubber bushes having different positions of the protrusion 33. Disappears.

Next, the operation of the above-mentioned rear suspension S will be described.

Explaining the case where the vehicle turns to the left side, when the vehicle turns, a lateral force F acts on the rear wheel 6 on the right side which is the outer wheel side, and the trailing arm 1 on the right side bounces relative to the vehicle body. The lateral force F acts as a force that displaces the front portion of the trailing arm 1 inward in the vehicle width direction. Here, before turning the vehicle, as described above, there is a gap 34 between the projection 33 of the rubber bush 3 and the side wall 40 of the vehicle body side bracket 4 (see also FIG. 3 ). In the initial stage of turning, the front part of the trailing arm 1 is smoothly displaced inward in the vehicle width direction. As a result, the rear wheels 6 can be toeed in and good understeer can be achieved.

The protruding portion 33 of the rubber bush then contacts the side wall portion 40 of the vehicle body side bracket 4 (
After this contact, the front part of the trailing arm 1 is restricted from being displaced inward in the vehicle width direction by this contact. Therefore, the front portion of the trailing arm 1 can be prevented from being excessively displaced inward in the vehicle width direction, and the lateral rigidity of the rear suspension S can be prevented from being significantly reduced.
For this reason, in the rear suspension S of the present embodiment, it is possible to improve ride comfort and maneuverability while maintaining good understeer steering characteristics.

The protrusion 33 of the rubber bush 3 has a non-ring shape as described above, but such a configuration is convenient when the rubber bush 3 is assembled to the trailing arm 1. That is, referring to FIG. 2A, the rubber bush 3 is assembled to the trailing arm 1 by pressing the rubber bush 3 into the rubber bush press-fitting hole portion 18 of the trailing arm 1 from the left side of FIG. Done. In this case, if the protrusion 33 has a ring shape, it becomes difficult to press the end surface portion 35 of the rubber bush 3 while avoiding the protrusion 33. If the protrusion 33 is pressed during the press-fitting, the protrusion 33 is greatly damaged and may be damaged. On the other hand, with the rubber bush 3 of the present embodiment, it is possible to appropriately press the portion of the end surface portion 35 where the protrusion 33 is not provided.

In the process from FIG. 3 to FIG. 4, the rubber bush 3 is displaced inward in the vehicle width direction while rotating in a direction in which the upper side turns around the vehicle front side. The rotation center of the rubber bush 3 at this time is a straight line connecting the shearing center of the torsion beam 2 and the central portion of the rubber bush 3, and does not coincide with the central axis L3 of the rubber bush 3. Therefore, when the trailing arm 1 bounces and the rubber bush 3 rotates, a part of the end face part 35 of the rubber bush 3 that approaches the side wall part 40 of the vehicle body side bracket 4 and a part that moves away from it. Will occur. In the present embodiment, the protrusion 33 is provided at a portion of such a portion that approaches the vehicle body side bracket 4, and the protrusion 33 can be appropriately brought into contact with the side wall portion 40. There is.

The present invention is not limited to the contents of the above-mentioned embodiment. The specific configuration of each part of the rear suspension according to the present invention can be modified in various ways within the scope intended by the present invention.
The specific shape, size, position and material of the protruding portion of the rubber bush are not limited. The protrusion is preferably provided integrally with the elastic body interposed between the outer cylinder and the inner cylinder, but it is also possible to intentionally form it by using an elastic body which is separate from the elastic body.

S Rear suspension L3 Rubber bush central axis 1 Trailing arm 2 Torsion beam 3 Rubber bush 30 Outer cylinder 31 Inner cylinder 32 Elastic body 33 Projection 34 Gap 4 Body side bracket

Claims (1)

A pair of left and right trailing arms that are located at intervals in the vehicle width direction and are connected to each other via a torsion beam, and have rear wheels attached to their rear portions,
A pair of left and right rubber bushes which are joined to the front parts of the pair of trailing arms and are attached to the vehicle body side bracket;
A protrusion provided on an end surface portion of each rubber bush on the inner side in the vehicle width direction, and protruding toward the inner side in the vehicle width direction,
Is equipped with
The central axis of each of the rubber bushes is a rear suspension that is set to be inclined so that the outer side is located rearward of the vehicle rather than the inner side in the vehicle width direction,
The protrusion of each of the rubber bushes is located in the upper half of the end face portion on the vehicle rear side in the normal state where the trailing arms are not bound and rebounded, and The rubber bush has an arc shape extending in the circumferential direction in a side view, and is provided so as to form a gap between the rubber bush and the vehicle body side bracket in the vehicle width direction. when the trailing arm bounces while receiving a lateral force in the vehicle width direction inner side is configured to abut on the vehicle body side bracket,
When one rubber bush of the pair of trailing arms is inverted and used as the rubber bush of the other trailing arm provided on the end surface portion of each rubber bush, the rubber bush of the other trailing arm. The rear suspension further comprising an additional protrusion that is the protrusion of the rear suspension.

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