JPH08230426A - Rear axle holding device for automobile - Google Patents

Abstract

PURPOSE: To provide a rear axle holding device which has simple constitution and is effective in generating compliance under-steer being excellent in running stability and operability against a disturbance. CONSTITUTION: A vehicle body 2 and rear axles 4, 5 suspended in the vehicle body 2 via a suspension spring are connected together via a pair of left and right torque rods 11 arranged along the longitudinal direction, and the rear axles 4, 5 are held. Axial lines of an outer 13a and a pin 13b in a rubber bush 13 connecting the base ends of the respective torque rods 11 to the vehicle body 2 are arranged parallelly to the vehicle width direction, while axial lines of an outer 15a and a pin 15b in a rubber bush 15 connecting the tips of the respective torque rods 11 to the rear axles 4, 5 are inclined so as to be shifted forward further toward the vehicle body center side, and as a result, compliance under-steer can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear shaft holding device for an automobile, and more particularly to a rear shaft holding device capable of enhancing running stability and maneuverability against disturbances.

[0002]

2. Description of the Related Art In a vehicle in which a vehicle body and a rear shaft suspended from the vehicle body via suspension springs are connected via a pair of left and right torque rods to hold the rear shaft, a pair of left and right torque rods is used. The lateral rod is often simplified or omitted by adopting a C-shaped array that gradually expands toward the front.

In such a C-shaped rear axle holding device, the front wheels are steered to generate a lateral force corresponding to the centrifugal force between the rear wheels and the ground, or when a lateral wind is received. When lateral force is generated, compliance steer occurs on the rear axle. Such compliance steer is due to the rotation of the rear shaft about the intersection of the extension lines of the torque rod due to the bending of the rubber bush interposed in the coupling portion of each torque rod.

By the way, when the intersection of the torque rods is located forward of the axis of the rear axle, the rear axle is rotated by the lateral force generated by the steering of the front axle and the rear axle is steered in the opposite direction to the front axle. As a result, the running stability may be impaired due to the compliance oversteer. Similarly, the rear wheels are steered even when a side wind is received in a straight traveling state, which causes a problem that a deviation occurs between the direction of the vehicle and the traveling direction.

Further, when the intersection of the torque rods is positioned behind the rear axle, the rear wheels are steered in a direction that corrects the change in the traveling direction due to cross wind, and the rear wheels are steered in the same direction as the steering direction of the front wheels. Since the compliance understeer of being steered is obtained, the running stability of the vehicle is increased.

However, when the torque rods are arranged in a V-shape in this manner, the shape of the torque rod bracket becomes complicated and the space for assembling the torque rod becomes large, so that the space for assembling other parts is restricted. There is a problem that it ends up.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a simple structure effective for causing compliance understeer with high running stability and maneuverability against disturbances. An object is to provide a shaft holding device.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a vehicle body and a rear shaft suspended from the vehicle body via suspension springs, which are connected to each other via a pair of left and right torque rods extending in the front-rear direction. In an automobile in which the rear axle is held, the axis of the outer side of the rubber bush and the pin connecting the base end of each torque rod to the vehicle body is set parallel to the vehicle width direction. Further, the shaft lines of the outer and the pin of the rubber bush connecting the tip of each torque rod to the rear shaft are inclined so as to be displaced forward toward the center side of the vehicle body.

[0009]

In the rear axle holding device of the automobile constructed as described above, when the lateral force due to the steering of the front wheels or the lateral force due to the lateral wind acts from the right side to the left side, for example, the tip end of the torque rod located on the right side is The pin of the rubber bush moves toward the center of the vehicle body, and the pin of the rubber bush at the tip of the torque rod located on the left side tries to move in parallel in the direction away from the center of the vehicle body. However, because the axes of the outer and pin of the rubber bush that connects the tip of each torque rod to the rear shaft are inclined so as to be displaced forward as the center of the vehicle body is approached, the torque rod located on the right side and the rear shaft are The pin of the rubber bush that couples the outer bush moves to the tip side of the outer, and the pin of the rubber bush that joins the torque rod and the rear shaft located on the left moves to the outer proximal end.

For this reason, the effective length of the torque rod located on the right side becomes larger than the effective length of the torque rod located on the left side, so that the rear axle moves the right side forward around the vicinity of the center of the vehicle body. To rotate. Therefore,
Even when the traveling direction of the vehicle body is to be changed to the left side due to the lateral force, the understeer effect by the correction of the traveling direction is obtained by the rotation of the rear shaft as described above, and the traveling stability is secured.

Further, the compliance understeer can be obtained by using the torque rods along the front-rear direction and only inclining the axial lines of the outer and pin of the rubber bush connecting the tip of each torque rod to the rear shaft. Therefore, the shape of the torque rod bracket does not become complicated, and the space for assembling the torque rod becomes large, and the space for assembling other parts is not restricted.

[0012]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic plan view showing an example of an automobile equipped with a rear shaft holding device according to the present invention, FIG. 2 is a side view showing an embodiment of the rear shaft holding device according to the present invention, and FIG. 3 is a tip of a torque rod. FIG. 4 is a cross-sectional view showing a specific example of a portion, FIG. 4 is a plan view showing a state of a torque rod when a lateral force does not act, and FIG. 5 is a plan view showing a state of a torque rod when a lateral force acts.

In these figures, a rear two-axle vehicle is constructed by suspending a rear front shaft 4 and a rear rear shaft 5 on a vehicle body 2 of an automobile equipped with front wheels 1 via a suspension spring 3 composed of a leaf spring. ing. An intermediate portion of the suspension spring 3 is rotatably attached to the vehicle body 2 via a trunnion bracket 6 to form a trunnion suspension.

The rear front shaft 4 is a drive axle to which the driving force from the engine 7 is transmitted, and the rear rear shaft 5 is a dead axle to which the driving force is not transmitted. Each of them is a vehicle body via a torque rod described later. The rear shafts 4 and 5 are held by being connected to the second shaft 2. Reference numeral 8 is a rear wheel attached to the shaft ends of the rear front shaft 4 and the rear rear shaft 5, and 9 is a steering wheel.

The torque rod includes a rear front shaft 4 and a rear rear shaft 5.
Upper torque rod 10 connecting the central portion of the vehicle body 2 to the central portion of the vehicle body 2, and a pair of left and right lower torque rods 11 connecting the left and right ends of the rear front shaft 4 and the rear rear shaft 5 to the vehicle body 2, respectively.
It is composed of These torque rods 10,
All 11 are arranged along the front-back direction.

The rubber bushes 12 and 13 connecting the base ends of the torque rods 10 and 11 to the vehicle body 2 and the tips of the upper torque rods 10 are connected to the rear front shaft 10 and the rear rear shaft 1, respectively.
The rubber bush 14 that is connected to the outer ring 1 is formed by the outer 12a, 13
The axes of a, 14a and pins 12b, 13b, 14b are set parallel to the vehicle width direction. In addition, the axes of the outer 15a and the pin 15b of the rubber bush 15 connecting the front ends of the lower torque rods 11 to the rear front shaft 4 and the rear rear shaft 5, respectively, are shown in FIGS. 1 and 3 to 5, respectively. It is inclined so as to be displaced forward as it reaches the side. 15c is an outer 15a and a pin 15b
Is a rubber that binds.

In the rear axle holding device of the automobile constructed as described above, when the front wheels 1 are not steered or a lateral force due to a side wind is not applied, as shown in FIG. 4, the upper torque rod 10 and the lower torque rod are used. Since both 11 are held parallel to the front-rear direction to hold the rear front shaft 4 and the rear rear shaft 5 parallel to the vehicle width direction, the straight running stability of the vehicle is ensured.

On the other hand, if a lateral force F due to steering of the front wheels or side wind acts from the right side to the left side, for example, FIG.
As indicated by solid lines, the torque bushes 10 and 11 rotate in the direction of the lateral force F due to the bending of the rubber bushes 12 and 13. Further, the pin 15b of the rubber bush 15 at the tip of the lower torque rod 11 located on the right side translates toward the center of the vehicle body 2, and the rubber bush 14 at the tip of the upper torque rod 10 and the lower torque rod 11 located on the left side.
Both of the pins 14b, 15b of the rubber bush 15 at the tip of are trying to move in parallel in the direction away from the vehicle body center.

However, a rubber bush 15 for connecting the tip of each lower torque rod 11 to the rear front shaft 4 and the rear rear shaft 5.
The outer 15a and the pin 15b are inclined so that the axis lines of the outer 15a and the pin 15b are displaced forward as they reach the center side of the vehicle body.
Deforms more in the shear direction than in the compression direction. For this reason, the pin 15b of the rubber bush 15 for connecting the lower torque rod 11 located on the right side to the rear front shaft 4 and the rear rear shaft 5 is formed.
The pin 15b of the rubber bush 15 that moves the lower torque rod 11 located on the left side of the outer 15a to the left front shaft 4 and the rear rear shaft 5 moves to the base end side of the outer 15a.

Therefore, when the lateral force F acts, both torque rods 10 and 11 rotate in the direction of the lateral force F around the rubber bushes 12 and 13 at the base ends as shown by the solid lines in FIG. 5, respectively. However, the effective length of the lower torque rod 11 located on the right side becomes larger than the effective length of the lower torque rod 11 located on the left side.

For this reason, the rear front shaft 4 and the rear rear shaft 5 are provided with a rubber bush 14 provided at the tip of the upper torque rod 10.
Rotate so as to move the right side forward around.
Therefore, even when the traveling direction of the vehicle body 2 is changed to the left side due to the lateral force F, the rear front shaft 4 as described above is
Also, by rotating the rear rear shaft 5, an understeer effect is obtained by correcting the traveling direction, and traveling stability is secured.

Further, the torque rod 10 along the front-rear direction,
While using 11, the compliance understeer can be obtained only by inclining the axis lines of the outer 15a and the pin 15b of the rubber bush 15 connecting the front end of the lower torque rod 11 to the rear front shaft 4 and the rear rear shaft 5. Therefore, the shape of the torque rod bracket does not become complicated, and the assembling space for the torque rods 10 and 11 does not become large so that the assembling space for other components is not restricted.

Although the present invention is applied to a rear two-axle vehicle in the embodiment, it may be applied to a rear single-axle vehicle.
Further, in the embodiment, the case where each rear shaft is held by three torque rods has been described, but the present invention is applied to a four-link type rear shaft holding device in which a pair of upper and lower torque rods are provided on the left and right. Alternatively, the suspension spring may be constituted by an air spring or the like.

[0024]

As is apparent from the above description, according to the present invention, a rubber that connects the front ends of the torque rods to the rear shaft while using the torque rods having a small mounting space and excellent in stability along the longitudinal direction. Since the compliance understeer can be obtained simply by inclining the bush outer and pin axes, the shape of the torque rod bracket is not complicated, and the torque rod mounting space is increased to assemble other parts. Space is not restricted.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing an example of an automobile provided with a rear shaft holding device according to the present invention.

FIG. 2 is a side view showing an embodiment of a rear shaft holding device according to the present invention.

FIG. 3 is a cross-sectional view showing a specific example of a tip portion of a torque rod.

FIG. 4 is a plan view showing a state of the torque rod when no lateral force acts.

FIG. 5 is a plan view showing a state of the torque rod when a lateral force acts.

[Explanation of symbols]

 1 front wheel 2 vehicle body 3 suspension spring 4 rear front shaft 5 rear rear shaft 6 trunnion bracket 8 rear wheel 10 upper torque rod 11 lower torque rod 12, 13, 14, 15 rubber bush 12a, 13a, 14a, 15a outer 12b, 13b, 14b, 15b Pin 15c Rubber F Lateral force

Claims (1)

[Claims] 1. A vehicle, wherein a vehicle body and a rear shaft suspended from the vehicle body via suspension springs are coupled to each other via a pair of left and right torque rods extending in the front-rear direction to hold the rear shaft. The axis of the rubber bush outer and pin that connect the base end of the to the vehicle body is set parallel to the vehicle width direction, and the axis of the rubber bush outer and pin that connects the tip of each torque rod to the rear axle is set to the vehicle body center side. A rear-shaft holding device for an automobile, wherein the rear-shaft holding device is inclined so as to be displaced forward as it comes to.