JPH07125516A - Rear suspension provided with lateral link - Google Patents

Abstract

PURPOSE:To realize brisk handling when side force is relatively low, and also improve turning stability when high side force is applied. CONSTITUTION:An attaching pin 5 is protruded from a torsion beam 3 toward the front of a vehicle, and one end of a lateral link 6 is connected to the attaching pin 5 so as to be oscillated. An axle side attaching part 6a and a lateral link main body 6b are integrally formed. The lateral link main body 6b is extended from the axle side attaching part 6a in the car width direction and also backward in the vehicle longitudinal direction, and the end is fixed to a car body side attaching part 6c. The car body side attaching part 6c is attached to a vehicle body side member. Thereby a vehicle body side attaching point B is made relatively offset backward from an axle side attaching point A in the vehicle longitudinal direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rigid rear suspension provided with a lateral link for lateral positioning, and more particularly to a rear suspension with a lateral link characterized by the arrangement of the lateral link and its mounting structure.

[0002]

2. Description of the Related Art As a conventional rear suspension with a lateral link, for example, there is one as shown in FIG. This is a rigid suspension in which both left and right wheels 1 are connected by a torsion beam 3 extending in the vehicle width direction. A lateral link 6 is arranged substantially parallel to the torsion beam 3 at a line connecting the wheel centers of the left and right wheels, that is, at a position in front of the torsion beam 3 in the vehicle front-rear direction. The lateral link 6 has both ends 6a, 6
c is swingably connected to the torsion beam 3 and the vehicle body side member to support the lateral force F1 input to the wheel 1.

The rear ends of a pair of trailing arms 4 are fixed to the torsion beam 3. Each of the trailing arms 4 extends forward in the vehicle front-rear direction, and its front end portion is connected to a vehicle body side member to position the rear suspension in the vehicle front-rear direction. In the rear suspension configured as described above, since the lateral link 6 is arranged on the front side of the torsion beam 3, the lateral force F1 when the vehicle is turning applies a moment in the toe-out direction to the turning outer wheel 1.

In order to deal with this, Japanese Patent Laid-Open No. 62-20
In the invention described in Japanese Patent No. 5810, the distance between the ends of the pair of trailing arms 4 is set to be wider than the distance between the axle-side mounting portions. As described above, when the rear suspension is supported by arranging the pair of trailing arms 4 in a state in which they are spread toward the front of the vehicle, the wheels 1 supported by the trailing arms when the lateral force F1 acts on the wheels 1. The instantaneous center of the rotational displacement of can be located behind the vehicle with respect to the line connecting the wheel centers of the left and right wheels.

As a result, when the lateral force F1 is relatively small, the swinging of the mounting portions 6a and 6c has a small effect on the position of the lateral link 6 and is greatly affected by the support structure of the trailing arm 4 to change the toe-in. Cause Furthermore, when a large lateral force F1 is applied, the position of the lateral link 6 is affected, and the change in the toe-in direction is suppressed, and the characteristics change in the toe-out direction.

[0006]

As in the above-mentioned conventional example,
When the high lateral force F1 is applied, changing the toe-out of the turning outer wheel 1 to eliminate the understeer of an FF vehicle or the like greatly deteriorates the stability of the vehicle, and in terms of running safety,
It becomes an unfavorable characteristic. The present invention has been made in view of the problems as described above, and realizes sharp handling when the lateral force is relatively low, and the turning stability when a high lateral force acts. Is intended to improve.

[0007]

In order to achieve the above object, the rear suspension with a lateral link of the present invention comprises:
A torsion beam that extends in the vehicle width direction and connects the left and right wheels, and a torsion beam that is swingably connected to the torsion beam with one end located at a front position in the vehicle front-rear direction of the torsion beam and that extends in the vehicle width direction and the other end is A rear suspension including a lateral link swingably connected to a vehicle body member is characterized in that a vehicle body side attachment point of the lateral link is offset rearward in a vehicle longitudinal direction from an axle side attachment point.

Alternatively, a torsion beam that extends in the vehicle width direction and connects the left and right wheels, and one end that swingably connects to the torsion beam extend in the vehicle width direction and the other end that swings to the vehicle body side member. In a rear suspension provided with a lateral link to be connected, the vehicle body side mounting points of the lateral links are two locations with a predetermined gap therebetween in the vehicle front-rear direction with the axis of the lateral link interposed therebetween, and the respective mounting points are The elastic rigidity of each elastic body disposed at the pair of vehicle body side mounting points in the vehicle width direction is relatively higher than that of the rear side in the vehicle front-rear direction. It is characterized by being set low.

[0009]

[Operation] When the vehicle turns and lateral force is input to the wheels,
The lateral force is transmitted to the lateral link via the torsion beam. At this time, as in the conventional case, when the lateral link is arranged in front of the torsion beam in the vehicle front-rear direction and with the axis oriented in the vehicle width direction, the outer ring side is attached to the axle side mounting portion of the lateral link by the input of the lateral force. A moment to rotate in the toe-out direction is generated.

On the other hand, in the rear suspension according to claim 1 of the present invention, the vehicle body side mounting portion of the lateral link is offset rearward in the vehicle front-rear direction from the axle side mounting point so that the lateral link is attached. The axis of the lateral link that connects the vehicle body side attachment point is set to be tilted in the vehicle front-rear direction with respect to the axle. Then, since the lateral force transmitted to the lateral link is directed in the vehicle width direction, this force is divided into a force in the axial direction of the lateral link and a force in the vehicle front-rear direction at the axle side mounting portion. I will be forced. Then, a rotational moment is input to the lateral link due to the component force directed in the vehicle front-rear direction, and the axle side mounting portion is displaced in the vehicle front-rear direction, whereby the lateral link mounting portion of the torsion beam is displaced in the vehicle front-rear direction. As a result, the axis of the torsion beam is tilted in the vehicle front-rear direction to give the turning outer wheel a toe-in direction displacement.

At this time, the both end mounting portions of the lateral link are swingably mounted by interposing bushes, but the characteristics of the bushes are generally soft for small inputs and large for large inputs. Hard set. Therefore, when the lateral force is relatively small, the rotational moment generated in the lateral link is absorbed by the swing of the mounting portion due to the bending of the bush, and is not transmitted to the torsion beam so much that the effect of the present application is small. Therefore, the turning outer wheel changes in the toe-out direction due to the conventional action of arranging the lateral link in front of the torsion beam.

Further, when a large lateral force is applied, the bush is bent and hardened by a predetermined amount, and the rotational moment generated in the lateral link is transmitted to the torsion beam as it is, and the turning outer wheel becomes large in lateral force. It changes in the toe-in direction by the displacement of the corresponding magnitude. Therefore, the toe characteristic of the rear suspension of the present invention draws a curve as shown in FIG. That is, when the vehicle turns gently with a small lateral force, the rear outer wheel is displaced in the toe-out direction and becomes in reverse phase with the steered front wheel, so that the turning performance is improved and the crisp handling performance is improved. Further, during a hard turning with a large lateral force, the rear outer wheel is displaced in the toe-in direction and becomes in phase with the steered front wheel, so that the running stability is improved.

Further, in the rear suspension according to the second aspect, when the lateral force is transmitted to the lateral link similarly to the above, the vehicle body side mounting portion side of the lateral link is interposed at the mounting point on the front side in the vehicle front-rear direction. Since the relative elastic rigidity of the elastic body is set lower, the elastic body at the attachment point on the front side bends more in the vehicle width direction than the elastic body at the attachment point on the rear side. For this reason, similarly to the above, due to the lateral force, a rotational moment of the lateral link in the vehicle front-rear direction is generated, and the torsion beam moves and tilts in the vehicle front-rear direction to give a displacement in the toe-in direction to the outer wheel.

As a result, the same operation as that of the invention of claim 1 can be obtained.

[0015]

Embodiments of the present invention will be described with reference to the drawings.
First, the configuration will be described. As shown in FIG. 1, the left and right wheels 1 are rotatably supported by wheel supporting members 2, respectively, and the left and right wheel supporting members 2 constitute an axle whose axis is oriented in the vehicle width direction. Are connected by a torsion beam 3. On each wheel side part of the torsion beam 3,
Each trailing arm 4 has a rear end portion rigidly connected thereto. Each of the trailing arms 4 extends toward the front of the vehicle and has its front end attached to a vehicle body side member so as to be swingable in the vertical direction, and is responsible for positioning in the vehicle front-rear direction and its force.

A mounting pin 5 projects from the right wheel side of the torsion beam 3 toward the front of the vehicle, and one end of a lateral link 6 is swingably connected to the mounting pin 5. The axle side mounting portion 6a of the lateral link 6 is configured by interposing a rubber bush between an inner cylinder and an outer cylinder which are substantially coaxial, and the lateral link main body 6b is integrally formed on the outer cylinder. In addition, the mounting pin 5 is inserted into the inner cylinder, and the nut 7 is screwed into the tip end of the mounting pin 5 to form the connecting portion.

The lateral link body 6b extends in the vehicle width direction and rearward in the vehicle front-rear direction from the axle side mounting portion 6a, and the outer cylinder of the vehicle body side mounting portion 6c is integrally fixed to the end thereof. . The vehicle body side mounting portion 6c is configured by interposing a rubber bush between an inner cylinder and an outer cylinder that are arranged substantially coaxially with the axis in the vehicle front-rear direction, and the inner cylinder side is mounted on the vehicle body side member. ing.

Here, by setting the extending direction of the lateral link body 6b as described above, the vehicle body side mounting point B of the lateral link 6 is located at the rear side S of the vehicle relative to the axle side mounting point A. This means that the offset has been set. A shock absorber (not shown) is installed near each end of the torsion beam 3.

In the rear suspension as described above, when the vehicle turns left, as shown in FIG. 2, a lateral force F1 directed to the left side is input to the wheel 1, and the lateral force F1 is transmitted via the torsion beam 3 to the lateral link. 6 is transmitted to the axle side mounting portion 6a. As shown in FIG. 3, the center axis P connecting the both end mounting portions of the lateral link 6 is inclined rearward in the vehicle front-rear direction with respect to the direction of the lateral force F2 input to the axle side mounting portion 6a. The lateral force F1 is decomposed into a force F3 directed toward the central axis P and a force F4 directed substantially forward in the vehicle front-rear direction.

Therefore, a rotational moment M is generated in the lateral link 6 toward the front in the vehicle front-rear direction by the component force F4 that is directed substantially in the vehicle front-rear direction about the vehicle body side attachment point B. As shown in FIG. 2, the rotational moment M causes the axle-side mounting portion 6a to be displaced forward in the vehicle front-rear direction, whereby the right wheel side of the torsion beam 3 is pulled forward in the vehicle front-rear direction via the mounting pin 5. Then, the displacement in the toe-in direction is input to the right wheel, that is, the turning outer wheel 1b.

When the vehicle turns right, a lateral force F1 directed to the right side is input to the wheel 1 as shown in FIG. 4, and the lateral force F1 is transmitted via the torsion beam 3 to the axle side mounting portion of the lateral link 6. 6a is transmitted. As shown in FIG. 5, the central axis P connecting the both end mounting portions of the lateral link 6 is inclined rearward in the vehicle front-rear direction with respect to the direction of the lateral force F2 input to the axle side mounting portion 6a. The lateral force F1 is decomposed into a force F3 directed to the central axis P and a force F4 directed substantially rearward in the vehicle front-rear direction.

Therefore, a rotational moment M is generated in the lateral link 6 toward the rear in the vehicle front-rear direction by a component force that is directed substantially rearward in the vehicle front-rear direction. As shown in FIG. 4, the rotational moment M pushes the right wheel side of the torsion beam 3 rearward in the vehicle front-rear direction via the axle side attachment portion 6a and the attachment pin 5 to the left wheel, that is, the turning outer wheel 1a. The displacement in the direction is input.

Since a rubber bush is interposed between the outer cylinder and the inner cylinder at the axle side mounting portion 6a which is a connecting member between the lateral link 6 and the torsion beam 3,
During a gentle turn in which the lateral force F1 is relatively small, the rotational moment M generated in the lateral link 6 is small, so that the rotational moment M is absorbed by the bending of the rubber bush and is not transmitted to the torsion beam 3 so much. .

However, the displacement in the toe-out direction is input to the turning outer wheel by the conventional action of the vehicle-body-side mounting portion 6c being disposed in front of the torsion beam 3 in the vehicle front-rear direction, and as a result, the lateral force F1 is generated. In a relatively small and gentle turn, displacement in the toe-out direction is input to the turning outer wheel, so that crisp handling can be realized.

Further, the vehicle makes a hard turn and the lateral force F
When 1 becomes larger, the rotational moment M generated in the lateral link 6 becomes larger in proportion to the lateral force F1, the displacement in the toe-in direction is input to the outer turning wheel, and the turning safety is improved. From the above, the toe characteristics as shown in FIG. 6 can be given to the turning outer wheel by the arrangement configuration of the lateral link 6 of the present embodiment.

The both ends mounting portions 6 of the lateral link 6 are
Since a and 6c have their axes oriented in the vehicle front-rear direction, as described above, regardless of the inclination of the lateral link body 6b, there is no left-right difference with respect to input due to road surface unevenness, and straightness is maintained. There is no effect. Further, in the above embodiment, the lateral link main body 6b extends linearly, but if it interferes with other members such as the torsion beam 3, the lateral main body is formed in an L shape as shown in FIG. 7, for example. It may be curved to avoid interference with other members.

In this case, the lateral force input to the vehicle body side mounting portion 6c becomes large. Therefore, in the example shown in FIG. 7, two vehicle body side mounting portions 6c are provided in series and are shown in FIGS. It is attached to the vehicle body side member. Of course, the vehicle body side mounting portion 6c may be one if the predetermined rigidity is secured. In the connection structure of the vehicle body side mounting portion shown in FIGS. 7 to 9, the lateral link body 6b is used as an inner cylinder, the rubber bush 8b is coaxially provided on the outer circumference, and the outer cylinder 8c is coaxially provided on the outer circumference of the rubber bush. The outer cylinder 8c is fixed to the vehicle body side member 9.

Even when the arrangement of the lateral links 6 is set in this way, the vehicle body side mounting portion 6c is not replaced by the axle side mounting portion 6a.
Since it is offset rearward in the vehicle front-rear direction, it has the same action and effect as above. Since the curved shape of the lateral link body 6b is an example, it may be arcuate or curved in the vertical direction.

Next, the second embodiment will be described. Second
As shown in FIG. 10, the basic structure of the rear suspension of the embodiment is the same as that of the first embodiment, but the structure and arrangement of the lateral link 6 are different. The lateral link 6 is arranged in front of the torsion beam 3 in the front-rear direction of the vehicle and with its axis oriented in the vehicle width direction, and its axle-side mounting portion 6a is provided so as to project from the right wheel side of the torsion beam 3 toward the vehicle front. It is swingably connected to the attached mounting pin 5.

Axle side attachment portion 6 of the lateral link 6
The a is configured by interposing a rubber bush between an inner cylinder and an outer cylinder that are substantially coaxial with the axis in the vehicle front-rear direction, and the lateral link body 6b is integrated with the outer cylinder. At the same time, the attachment pin 5 is inserted into the inner cylinder, and a nut is screwed into the tip end of the attachment pin 5 to form the connection portion.

The lateral link body 6b extends in the vehicle width direction from the axle side mounting portion 6a. The ends of the lateral links 6 in the extending direction are bifurcated, and the tips of the pair of legs 6d are arranged with a predetermined span in the vehicle front-rear direction with the axis P of the lateral link body 6b interposed therebetween. ing. The body side mounting portion 6 is attached to each of the tip portions.
The outer cylinders e and 6f are fixed.

Each of the vehicle body side mounting portions 6e and 6f is constructed by interposing an elastic rubber bush between an inner cylinder and an outer cylinder which are arranged substantially coaxially with their axes in the vehicle front-rear direction. The inner cylinder side is attached to the vehicle body side member.
The pair of vehicle body side mounting portions 6e and 6f are set such that the front side 6e of the vehicle in the vehicle front-rear direction has a flexural rigidity relatively lower in the vehicle width direction than the rear side 6f.

The flexural rigidity is set, for example, as shown in FIG. 11, in the rubber bush 8b of the vehicle body side member on the front side.
A pair of curls 10 are provided to sandwich the inner cylinder 8a to reduce the rigidity, or, as shown in FIG. 12, rubber bushes 8b provided with the above-mentioned curls 10 are adopted for both vehicle body side members so that the direction of the curls 10 can be changed. , On the front side in the vehicle width direction (FIG. 12A),
On the rear side, it is set by pointing in the vertical direction (FIG. 12B).

Alternatively, the diameter of the outer cylinder 8c may be made relatively smaller at the rear vehicle body mounting portion than at the front vehicle body mounting portion, and the radial thickness of the rubber bush 8b may be made different to allow bending. The rigidity may be different. In this case, since the size of the rubber bush 8b is different, it is possible to prevent erroneous assembly of the rubber bush 8b. Of course, the above-described flexural rigidity setting means is an example, and other known means such as embedding a stiffening member in the rubber bush 8b to change the flexural rigidity may be adopted.

In the rear suspension having the above structure, when the vehicle turns left, as shown in FIG.
Lateral force F1 toward the left side is input to this lateral force F
1 is transmitted to the axle side mounting portion 6a of the lateral link 6 via the torsion beam 3. Axle side attachment part 6
The rubber bushes 8b of the vehicle body side mounting portions 6e and 6f are both compressed in the direction of the lateral force F2 input to a, but the front side 6e of the rubber bushes 8b bends more,
As shown in FIG. 14, at the vehicle body side mounting points B1 and B2, the front side mounting point B1 is displaced more in the vehicle width direction than the rear side mounting point B2.

For this reason, front and rear vehicle body side mounting points B1, B
Rotational moment M with the center of rotation between 2 as the center of rotation
Occurs on the lateral link 6. Due to this rotational moment M, the axle side mounting portion 6a is displaced forward in the vehicle front-rear direction, and as shown in FIG. 13, the right wheel side of the torsion beam 3 is pulled forward through the attachment pin 5 to the right in the vehicle front-rear direction. The displacement in the toe-in direction is input to the wheel, that is, the turning outer wheel 1b.

When the vehicle turns right, a lateral force F1 toward the right side is input to the wheel 1 as shown in FIG. 15, and this lateral force F1 is transmitted through the torsion beam 3 to the axle side of the lateral link 6. It is transmitted to the mounting portion 6a. The rubber bushes 8b of the vehicle body side mounting portions 6e and 6f are pulled in the direction of the lateral force F2 input to the axle side mounting portion 6a, but the rubber bush 8b of the front side 6e is bent more. Among the vehicle body side attachment points B1 and B2, the front attachment point B1 is displaced in the vehicle width direction more than the rear attachment point B2.

Therefore, a rotational moment M about the center of the front and rear mounting points on the vehicle body is generated in the lateral link 6. Due to this rotational moment M, the axle-side mounting portion 6a is displaced rearward in the vehicle front-rear direction, and the right wheel side of the torsion beam 3 is pushed rearward in the vehicle front-rear direction via the mounting pin 5 to the left wheel, that is, the turning outer wheel. The displacement in the direction is input.

Here, since the rubber bush 8b is interposed between the outer cylinder 8c and the inner cylinder 8a at the axle side mounting portion 6a which is a connecting member of the lateral link 6 and the torsion beam 3, the lateral force is increased. During a gentle turn where F1 is relatively small, the rotational moment M generated in the lateral link 6 is small, so that the rotational moment M is absorbed by the bending of the rubber bush 8b, and the torsion beam 3 is generated.
Not very well transmitted.

However, the vehicle body side mounting portions 6e, 6f
Is placed in front of the torsion beam 3 in the front-rear direction of the vehicle, the displacement in the toe-out direction is input to the turning outer wheel by the conventional action.
When 1 is a relatively small and gentle turn, displacement in the toe-out direction is input to the turning outer wheel, so that crisp handling can be realized.

When the lateral force F1 becomes larger due to a harder turning, the rotational moment M generated in the lateral link 6 becomes larger in proportion to the lateral force F1 and the displacement in the toe-in direction is input to the outer turning wheel. , Driving safety is improved. From the above, the toe characteristics similar to those of the first embodiment can be imparted to the turning outer wheel even by the arrangement configuration of the lateral link 6 of the second embodiment.

In the lateral link 6 of the second embodiment, the pair of vehicle body side mounting portions 6e and 6f are symmetrically arranged in the vehicle longitudinal direction with the axis P of the lateral link 6 interposed therebetween. To the respective vehicle body mounting portions may be different, and both vehicle body side mounting portions 6e, 6
f may be relatively offset in the vehicle width direction.

Further, the lateral link main body 6b may be arranged so as to be inclined in the vehicle front-rear direction by using the structure of the first embodiment together.

[0044]

As described above, the rear suspension with a lateral link of the present invention can improve the turning stability of the vehicle.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a rear suspension of an embodiment according to the present invention.

FIG. 2 is a schematic plan view showing the action of the embodiment of the present invention when turning left.

FIG. 3 is a schematic view showing the action of the embodiment of the present invention when turning left.

FIG. 4 is a schematic plan view showing the action of the embodiment of the present invention when turning to the right.

FIG. 5 is a schematic view showing the action of the embodiment of the present invention when turning to the right.

FIG. 6 is a diagram showing toe change characteristics of an example according to the present invention.

FIG. 7 is a schematic plan view showing a rear suspension according to an embodiment of the present invention.

FIG. 8 is a side view showing a vehicle body side mounting portion of a lateral link according to an embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a vehicle body side attachment portion of a lateral link according to an embodiment of the present invention.

FIG. 10 is a schematic plan view showing a rear suspension of the second embodiment according to the present invention.

FIG. 11 is a view showing a bush structure of a vehicle body side mounting portion of a second embodiment according to the present invention.

FIG. 12 is a view showing a bush structure of a vehicle body side mounting portion of a second embodiment according to the present invention.

FIG. 13 is a schematic plan view showing the action of the second embodiment according to the present invention when turning to the left.

FIG. 14 is a schematic view showing the operation of the second embodiment according to the present invention when turning to the left.

FIG. 15 is a schematic plan view showing the action of the second embodiment according to the present invention when turning to the right.

FIG. 16 is a schematic plan view showing a conventional rear suspension.

[Explanation of symbols]

 1 Wheel 3 Torsion Beam 6 Lateral Link 6a Axle Side Attachment 6b Lateral Link Main Body 6c, 6e, 6f Vehicle Side Attachment F1, F2 Lateral Force M Rotation Moment P Axis

Claims (2)

[Claims] 1. A torsion beam that extends in the vehicle width direction and connects left and right wheels, and a torsion beam that is swingably connected to the torsion beam with one end located at a front position of the torsion beam in the vehicle front-rear direction and extends in the vehicle width direction. In a rear suspension provided with a lateral link that swingably connects the other end to a member on the vehicle body side, the vehicle body side attachment point of the lateral link is offset rearward in the vehicle longitudinal direction from the axle side attachment point. Rear suspension with lateral link featuring. 2. A torsion beam extending in the vehicle width direction and connecting left and right wheels, and one end swingably connected to the torsion beam so as to extend in the vehicle width direction and the other end swingable to a vehicle body side member. In a rear suspension provided with a lateral link to be connected, the vehicle body side mounting points of the lateral links are two locations with a predetermined gap therebetween in the vehicle front-rear direction with the axis of the lateral link interposed therebetween, and the respective mounting points are The elastic rigidity of each elastic body disposed at the pair of vehicle body side mounting points in the vehicle width direction is relatively higher than that of the rear side in the vehicle front-rear direction. Rear suspension with a lateral link characterized by being set low.