JPH06106934A - Rigid axle type rear suspension - Google Patents

Abstract

PURPOSE:To suppress a tread change by providing trailing arms of connecting one end part to an axle and the other end part to a car body side through a bush, torque rods of connecting one end part to the axle and a torsion beam capable of extending/contracting in the axial direction by connecting the axles in a car width direction. CONSTITUTION:Trailing arms 3 of connecting rear ends to right/left axles 2a, 2b are extended to the front and connected to a car body side member through bushes 4. Both end parts of torque rods 6 are connected respectively to the axles 2a, 2b and the halfway of the trailing arm 3, and the axles 2a, 2b are connected by a torsion beam 7. The torsion beam 7 is constituted by providing bearings 9 respectively in both end part sides of a rod 8 extended in the axial direction, so that a sheathing member 11 extended in the axial direction from an upper side is coaxially covered, to integrally connect a right end of the sheathing member 11 to the right side axle 2a and also integrally connecting a left end of the rod 8 to the left side axle 2b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rigid suspension type rear suspension that does not require a lateral link.

[0002]

2. Description of the Related Art A conventional rigid axle type rear suspension is disclosed in, for example, Japanese Patent Application Laid-Open No. 57-130805. This kind of suspension
Left and right wheels are connected by a torsion beam arranged in the vehicle width direction, and a lateral link rotatably connecting one end to the torsion beam is extended in the vehicle width direction,
The other end is rotatably connected to a side member or the like that is a vehicle body side member, and the lateral force that is input is supported by a lateral link.

[0003]

However, in the rigid axle type rear suspension as described above, when the wheels bounce and rebound while traveling on a bad road or the like, the lateral link follows the vertical movement of the left and right wheels. There is a problem in that the vehicle rotates in the vertical direction, the lateral displacement generated by the arc motion of the lateral link is input to the vehicle body, and the vehicle body rolls laterally.

Further, since the distance between the left and right wheels is constant due to the torsion beam, when the left and right wheels bounce and rebound separately while traveling on an irregular road, the torsion beam tilts obliquely in the horizontal direction. There is also a problem that the left and right wheels are shortened and skid occurs on the wheels. Further, unless the attachment structure of the lateral link is devised, when the vehicle body rolls, the jack-up amount and the load movement amount of the vehicle body differ between left turning and right turning.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a rigid axle type rear suspension which suppresses a change in tread.

[0006]

In order to achieve the above object, a rigid axle type suspension of the present invention comprises left and right axles for individually supporting the left and right wheels, respectively.
Left and right trailing arms, one end of which is connected to the axle and the other end of which is connected to the vehicle body side via a bush, and left and right torque rods that are connected to the axle at one end to restrict rotation of the axle. And a torsion beam that connects the left and right axles in the vehicle width direction and can expand and contract in the axial direction.

At this time, it is preferable that the trailing arm is attached to the axle at a position rearward of the wheel center of the left and right wheels.

[0008]

Since the left and right wheels are connected by the torsion beam, even if the vehicle body is rolled by turning, the ground camber hardly changes as in the conventional case. Further, since the lateral force input from the left and right wheels is transmitted to the trailing arm via the axles supporting the wheels, respectively, and the trailing arm supports the lateral force, the lateral force for supporting the lateral force is set. The lateral link is no longer needed, and the bouncing
Rolling of the vehicle body that occurs at the time of rebound is eliminated, and there is no difference in the jack-up amount and the load movement amount when turning left and right due to the lateral link.

Further, even if only one wheel bounces or rebounds and the torsion beam pivots in the vertical direction and tilts, the torsion beam expands and contracts, and the tread between the left and right wheels does not change in the horizontal direction. The left and right wheels do not skid, tire wear and the like are suppressed more than before, and steering stability is improved. Since the torsion beam and the axle are connected to the trailing arm, a torque rod is provided in the present invention to support the braking reaction force, that is, to prevent the axle from rotating due to the reaction force of the braking force. is doing.

Further, by arranging the mounting position of the trailing arm to the axle so as to be offset to the rear of the vehicle body with respect to the wheel center of the left and right wheels, even if a lateral force such as a side wind is input during straight traveling, the axle and the torsion beam are It acts as a moment in the toe-in direction, and the rear wheels tend to understeer, improving straight running performance.

[0011]

Embodiments of the present invention will be described with reference to the drawings.
First, the structure will be described. As shown in FIG. 1, wheels (not shown) are rotatably supported on the left and right axles 2a and 2b, respectively, and the rear ends of the trailing arms 3 are vertically moved on the respective axles 2a and 2b. Is rotatably connected to. The trailing arm 3 has a shape extending forward and bifurcating on the front side, and each tip end thereof is rotatably connected to a vehicle body side member (not shown) via a bush 4.

The pivot shafts on the vehicle body side by the bushes 4 of the left and right trailing arms 1 are arranged so as to be coaxial with each other in the vehicle width direction. In addition, each axle 2a,
A lower end portion of the shock absorber 5 is swingably fixed to each of the shock absorbers 2b, and an upper end portion of the shock absorber 5 is fixed to a vehicle body-side member (not shown).

Further, one end of a torque rod 6 is swingably connected to the upper portion of each axle 2a, 2b, and the other end of the torque rod 6 is swingable in the middle of the trailing arm 3. It prevents the axle from rotating due to the reaction of the braking force. Furthermore, the left and right axles 2a, 2b are connected by a torsion beam 7 whose axis is oriented in the vehicle width direction.

The torsion beam 7 has a structure as shown in FIG. That is, the rolling bearings 9 are provided on both ends of the long rod 8 extending in the axial direction. In the rolling bearing 9, for example, as shown in FIG. 3, an inner cylinder 9a is fitted to the outer circumference of the end portion of the rod 8, and a plurality of inner rings extending in the axial direction of the rod 8 are formed on the outer peripheral surface of the inner cylinder 9a. ing. An outer cylinder 9b serving as a housing is arranged on the outer periphery of the inner cylinder 8, and an outer ring facing the inner ring is formed on the inner peripheral surface of the outer cylinder 9b, and a plurality of steel plates are provided between the inner ring and the outer ring. A ball 9c is rollably interposed. Further, one ends of dust boots 10 are attached to both ends of the outer cylinder 9b, and the dust boots 10 extend in the axial direction and slidably abut the other ends on the outer peripheral surface of the rod 8, Dust is prevented from entering the rolling bearing 9.

Then, the rod 8 having the rolling bearing 9 as described above is covered with an exterior member 11 having an inverted U-shaped vertical section and extending in the axial direction so as to be coaxial with the rod 8 from above. The outer cylinder 9b of the rolling bearing 9 is the exterior member 1
It is engaged with the inner peripheral surface of 1 and fixed to the exterior member 11 by a bracket 12. In the torsion beam 7 having the above configuration, the right end of the exterior member 11 is integrally connected to the right axle 2a, and the left end of the rod 8 is connected to one end of the left axle 2b, so that the left and right axles 2a and 2b are laterally aligned. The exterior member 11 and the rod 8 forming the torsion beam 11 relatively expand and contract in the axial direction according to the swinging of the.

In the normal state, the rod 8 is
The left end of is protruded leftward from the exterior member 11 by a predetermined amount and is arranged to be contractible. In the vehicle having the rear suspension configured as described above, even if the vehicle body is rolled by turning, the link arrangement that connects the left and right wheels 1 is not changed by the torsion beam 7. Therefore, as in the conventional case, the opposite camber is almost changed. There is no.

Further, a lateral force is input to the wheel 1 at the time of turning or the like, but the lateral force is transmitted to the trailing arm 3 via the axles 2a, 2b, and the vehicle body of the trailing arm 3 is transmitted. The bush 4 of the side mounting portion is bent and absorbed. For this reason, a lateral link that receives a lateral force is not necessary, and there is no rolling of the vehicle body caused by the rotation of the lateral link when bounding or rebounding on an irregular road, etc. Since the center of rotation is eccentric, the difference in jack-up amount and load movement amount between left turn and right turn, which occurred in the conventional suspension when turning, disappears, and the above difference when turning left and right. Does not occur.

When the vehicle travels on an irregular road, the left and right wheels bounce and rebound separately, so that the torsion beam 7 connecting the left and right wheels pivots vertically and tilts. For example,
When one wheel 1a rides on and bounces on the projection 20 on the road surface, the one wheel 1a rotates upward with the center of rotation on the other wheel 1b side. As shown in FIG. 4, the ground contact portion A with the road surface of the one wheel 1b has a constant value.
Is displaced by a predetermined displacement amount δ in the vehicle width direction, and the wheel 1 skids sideways. In this embodiment, as shown in FIG. 5, the torsion beam 7 expands and contracts in the vehicle width direction by the displacement amount δ. Since the lateral displacement is absorbed and the wheels 1 do not skid, steering stability on rough roads is improved.

Further, the suspension structure of this embodiment is
Since the trailing arm 3 is connected to the vehicle body without a supporting mechanism such as a Panhard rod, the trailing arm 3 supports the lateral force. Therefore, when the vehicle travels straight ahead, as shown in FIG.
Is input, the trailing arm 3 rotates in the oversteer direction (toe-out direction) M1.

However, as shown in FIG. 6 (b),
Since the axles 2a and 2b are not rigidly connected to the trailing arm 3 but are connected to the trailing arm 3 via the bushes, the axles 2a and 2b are kept in parallel with each other regardless of the rotational movement of the trailing arm 3 in the lateral direction. Relative movement (to the left in FIG. 6). On the other hand, the support point of the trailing arm 3 and the torsion beam 7, that is, the mounting position of the trailing arm 3 to the axles 2a and 2b is determined by the wheel center W.
Since it is offset rearward from C, a lateral force F2 applied to the axles 2a and 2b from the wheel 1 and a reaction force F1 applied from the trailing arm 3 generate a couple in the understeer direction (toe-in direction) to generate a torsion beam. 7 bends, and the left wheel is slightly displaced in the toe-out direction and the right wheel is slightly displaced in the toe-in direction to cause an understeer tendency, which improves the stability of the vehicle and improves the straight running performance.

In the above embodiment, the rod 8 constituting the torsion beam 7 and the exterior member 11 are connected to each other by a rolling bearing 9 so as to be capable of expanding and contracting in the axial direction. The torsion beam 7 may be made expandable / contractible by using a bearing, and the structure of the torsion beam 7 is not limited to that in the above embodiment, and may be a double tube structure. The point is that it can be expanded and contracted in the axial direction.

The trailing arm 3 may have a dual link structure.

[0023]

As described above, in the rigid axle type rear suspension of the present invention, when the vehicle body rolls, the ground camber hardly changes as in the conventional case. In addition, because the structure does not require a lateral link, rolling of the lateral link eliminates rolling of the vehicle body, and the torsion beam expands and contracts even if the left and right wheels individually bounce and rebound due to bad roads. The side slip that occurs on the left and right wheels is reduced, and steering stability is improved.

Further, by disposing the trailing arm attachment portion to the axle rearward of the wheel center of the left and right wheels, a moment that tends to understeer against the input of lateral force such as side wind during straight running is generated. It becomes possible to obtain straight driving performance.

[Brief description of drawings]

FIG. 1 is a perspective view showing a rigid axle type rear suspension according to an embodiment of the present invention.

FIG. 2 is an exploded view of the rigid axle type rear suspension.

FIG. 3 is a diagram showing a rolling bearing.

FIG. 4 is a view showing a conventional state when one wheel bounces.

FIG. 5 is a diagram showing a state in the present embodiment when one wheel bounces.

FIG. 6 is a schematic diagram showing compliance steering when a lateral force is input.

[Explanation of symbols]

 2a, 2b Axle 3 Trailing arm 4 Bushing 6 Torque rod 7 Torsion beam 8 Rod 9 Rolling bearing 11 Exterior member

Claims (2)

[Claims] 1. Left and right axles for individually supporting the left and right wheels, left and right trailing arms having one end connected to the axle and the other end connected to a vehicle body through a bush, and one end A rigid axle type in which a portion is provided with left and right torque rods that are connected to an axle to restrict rotation of the axle, and a torsion beam that connects the left and right axles in the vehicle width direction and is expandable and contractible in the axial direction. Rear suspension. 2. The rigid axle rear suspension according to claim 1, wherein the trailing arm is attached to the axle at an offset position rearward of the wheel center of the left and right wheels.