JPS63240413A - Suspension device for automobile - Google Patents

Abstract

PURPOSE:To carry out proper toe control by utilizing a driving reaction, by mounting a member for supporting a differential gear on the front or rear side of a rear wheel driving shaft, through an elastic member to a vehicle body. CONSTITUTION:A differential gear is located at an intermediate position between right and left rear wheels 3. A driving shaft 4 is connected through a wheel supporting member 5 to each rear wheel 3. A bracket 6 is mounted on the front side of a differential gear case 2, and the bracket 6 is mounted through an elastic member 7 to a vehicle body 8. Another bracket 9 is mounted to the gear case 2 on the rear side of the driving shaft 4. The bracket 9 is mounted through elastic members 10 and 11 to the vehicle body 8. Two lateral links 12 and 13 are pivotably connected at their outer ends to each wheel supporting member 5. The inner ends of one of the lateral links 12 and 13 are mounted to the opposite ends of the bracket 9.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a suspension device for an automobile, and more particularly, the present invention relates to a rear wheel suspension device that performs toe control by adjusting the mounting conditions of suspension support members, lateral links, etc. Regarding equipment.

(Prior art) An automobile suspension device plays the role of damping the vibrations of the wheels so that they are not directly transmitted to the vehicle body.From this point of view, Japanese Patent Publication No. 56-47008 describes the suspension device. A support structure is disclosed in which the structure of the bushing interposed between the bushing and the vehicle body is improved to enhance the vibration damping effect. In this disclosed device, the bush compresses and deforms due to vibration in the vertical direction, thereby causing 1. It has a structure that absorbs vibrations from the wheels, and the elastic modulus in the vertical direction changes according to displacement.

Furthermore, it has been conventionally known to perform toe control using a suspension device. For example, Japanese Utility Model Publication No. 59-966 discloses a rear wheel suspension device that prevents the tendency to toe out during turns and ensures running stability. The disclosed suspension device includes an arm member extending in the longitudinal direction and two arms extending in the lateral direction, one end of which is attached to a wheel support member, and the other end supported by the vehicle body. . In this case, the above horizontal arm is
It is attached to the wheel support member via a deformable bushing in such a positional relationship that a toe-in tendency occurs when a lateral force is applied to the wheel.

Further, in Japanese Utility Model Application Publication No. 61-48808, one end of a link member that can swing vertically is attached to both sides of a suspension support member, that is, a suspension cross member, and the other end of this link member supports a wheel. A rear suspension device is disclosed,
In this device, the suspension cross member is attached to the vehicle body in the longitudinal direction via two types of buffer members.

In this case, the stiffness of the front shock absorbing member of the cross member is set to be smaller than the stiffness of the rear shock absorbing member, so that a toe-in tendency occurs when a lateral force is applied.

In these conventional suspension devices, toe changes are caused by lateral forces that act during turning.

By the way, while the vehicle is running, a drive reaction force from the road surface also acts on the vehicle, so there is a limit to the conventional configuration in which toe control is performed by considering only the lateral force.

Additionally, since the requirements for toe control vary depending on the characteristics of the vehicle, it is necessary to perform appropriate control that corresponds to each requirement, but conventional methods cannot sufficiently meet these requirements. Ta.

For example, a toe-in tendency is desirable to ensure driving stability, but in the case of a front-heavy vehicle,
As the driving force increases, the problem arises that there is a tendency to understeer, that is, a tendency to under-power, which deteriorates steering controllability. Therefore, in such a vehicle, a tendency to toe-out rather than toe-in occurs. Preferably controlled.

(Means for Solving the Problem) The present invention utilizes drive reaction force acting on the vehicle while driving to provide desired toe change characteristics, thereby performing appropriate toe control according to the characteristics of the vehicle. The purpose is to provide a suspension device that can.

An automobile suspension device according to the present invention includes a rear wheel differential gear device that transmits driving force to a rear wheel drive shaft;
A differential gear support member that supports the differential gear device in front of or behind the rear wheel drive shaft, and two lateral links arranged in the front-rear direction and extending substantially horizontally and laterally, one of the lateral links. A lateral inner end of the link is attached to the differential gear support member, and an inner end of the other lateral link is an automobile suspension device attached to the vehicle body, and the differential gear support member is attached to the vehicle body via an elastic member. It is characterized by being attached.

(Function) When a vehicle having a suspension device with the above structure is running by driving force, instead of the driving force being transmitted from the wheels to the road surface, a driving reaction force is generated from the road surface in the opposite direction to the driving force. transmitted to the vehicle.

This reaction force is transmitted to the differential gear device via the drive shaft of the wheel, and acts on a suspension support member that supports this device. In this case, the reaction force acts to displace the rear side of the differential gear device downward and the front side upward.

The differential gear device is coupled to the differential gear support member behind the drive shaft, so that the inner end of the rear lateral link is coupled to the differential gear support member, and the inner end of the front lateral link is attached to the vehicle body. In this structure, when the above drive reaction force acts, a force that pulls the differential gear support member downward acts on the differential gear support member.

As a result, the differential gear support member is displaced downward due to the displacement of the elastic member interposed between it and the vehicle body.

However, since the inner end of the front lateral link is coupled to the vehicle body, vertical displacement due to drive reaction force does not occur.

Therefore, the inner end of the posterior lateral link is relatively
Lower than the inner end of the front lateral link.

When turning, the vehicle bumps and the vehicle body sinks into the outer wheels, but both lateral links tend to have the same tendency, and the ones attached to the outer end are displaced downward around the outer wheels. do.

In this way, the inner ends of the front and rear lateral links move differently, producing an effect that rotates the rear wheel within a horizontal plane. That is, when the inner end of the rear lateral link becomes relatively low as described above, the rear side of the wheel rotates so as to be drawn inward, resulting in a tendency to toe out.

In addition, the differential gear device is supported by a differential gear support member on the front side of the drive shaft, and this differential gear support member is supported by the vehicle body via an elastic member, and the front lateral link is connected to the differential gear support member on the rear side. A similar effect can be obtained when the lateral link is attached to the vehicle body. That is, when the drive reaction force is input to the differential gear device, the inner end of the front lateral link becomes higher, contrary to the above, but in this case, due to the bump condition, the front lateral link is affected by the drive reaction force. Similarly, the inner end of the rear lateral link is displaced in a larger amount than the inner end of the front lateral link. Therefore, similar to the above, a toe-out tendency occurs.

Furthermore, during a braked turn in which the vehicle turns while using the engine brake, the direction of action of the drive reaction force is opposite to that described above, so that the vehicle tends to toe-in.

(Effects of the Invention) With the above configuration, the suspension device of the present invention can suppress toe-out tendency and suppress oversteer tendency during braking turning using engine braking, thereby ensuring driving safety. can.

Furthermore, during drive turning, toe control can be performed using drive reaction force depending on the characteristics of the vehicle. For example, in a front-heavy vehicle, it is possible to generate a moderate toe-out tendency, thereby preventing a power-under tendency, and provide a suspension device with high steering controllability.

(Description of Examples) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic plan view of the lower part of a vehicle incorporating the suspension device 1 of the present invention, and FIG.
1 is a schematic elevational view of this suspension device 1. FIG.

Referring to FIGS. 1 and 2, a differential gear case 2 that accommodates a differential gear device (not shown) for rear wheels is provided at the rear of the vehicle of this example.

The differential gear device is located in the middle of a line connecting the two rear wheels 3, and the rear wheel 3 has an axle that is connected to the differential gear device and extends laterally to transmit driving force to the rear wheels 3. The drive shaft 4 is connected to the wheel support member 5
connected via.

A bracket 6 is attached to the front side of the differential gear case 2, and this bracket 6 is attached to the vehicle body 8 via elastic members 7 at two locations. In this example, these elastic members 7 serve only to absorb vibrations, and do not affect toe control. Further, a bracket 9 is fixed to the rear side of the drive shaft 4 of the differential gear case 2, and this bracket 9 is attached to the vehicle body 8 via an elastic member 10.11.

Further, in the suspension device 1 of this example, the inner ends 12aS and 13a of the two lateral links 12 and 13 extending in the substantially horizontal direction and the lateral direction are attached to be rotatable in the vertical direction. Outer ends 12b, 13b of lateral links 12.13
are attached to arm portions 5a and 5b formed on the wheel support member 5 and extending forward and rearward so as to be rotatable in the vertical direction.

The operation of the device having the above structure will be explained.

While the vehicle is running, the rear wheels 3 receive a driving reaction force from the road surface 14 in the direction of the arrow in FIG. 2, that is, clockwise. This drive reaction force acts on the differential gear case 2 so as to pull the rear end downward.

Since the differential gear case 2 is attached to the vehicle body 8 via the bracket 9 and the elastic member 10.11, it rotates slightly clockwise, and therefore the inner end 13a of the rear lateral link 13 also moves slightly downward. Displace.

On the other hand, since the inner end of the front lateral link 12 is directly connected to the vehicle body 8, it is not displaced by the action of the driving reaction force. Therefore, due to the action of the driving reaction force, the inner end of the rear lateral link is located below the inner end of the front lateral link.

When turning, the outside of the rotation of the vehicle body is in a bump state, and the vehicle body sinks relative to the rear wheels 3.

As a result, the parts 12a and 13a are attached to the inner end of the lateral link 12.13, and the parts 12b and 1 are attached to the outer end of the lateral link 12.13.
Rotate downward around 3b.

Since the displacement tendency in this bump state is not different between the front and rear links, it does not affect the toe change.

Therefore, the drive reaction force rotates the rear wheel 3 in a horizontal plane via the wheel support member 5. In this case, since the inner end 13a of the rear lateral link 13 is located lower than the front side, the rear side of the wheel 3 is relatively drawn inward, thereby causing a tendency to toe out.

As a result, for example, in front-heavy vehicles, it is possible to suppress the tendency to under-power and maintain good controllability.

In addition, when turning while using the engine brake (so-called brake turning), the drive reaction force acts in the opposite direction to the above, so the displacement tendency of the lateral link is also reversed, causing a toe-in tendency in the wheels. .

Therefore, when turning while braking, oversteer tendency can be prevented and running stability can be ensured.

Another embodiment of the invention is shown in FIGS. 3 and 4.

In this example, the differential gear case 2 includes a drive shaft 4
It is attached to the vehicle body 8 via a bracket 9 and an elastic member 10.11 on the front side.

In this example, the inner end 12 of the front lateral link 12
a is coupled to the differential gear case 2, and the inner end 13a of the rear lateral link 13 is attached to the vehicle body 8.

Therefore, in this example, when the driving reaction force acts,
The inner end 12a of the front lateral link 12 is displaced upward.

However, since the displacement relationship with the rear lateral link 13 is the same as in the previous example, the tendency of the wheel toe change is also the same as in the previous example. As a result, a tendency to toe-out occurs when a drive reaction force is applied during normal driving, and a tendency to toe-in occurs when turning while braking using the engine brake.

Therefore, even with just one example, the same effect as the previous example can be obtained.

In addition, in the structure of this example, since one of the lateral links is directly attached to the vehicle body, there is also an advantage that the lateral rigidity of the suspension device can be improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the framework of a suspension device according to one embodiment of the present invention, FIG. 2 is an elevational view of the suspension device of FIG. 1, and FIG. 3 is a plan view of the suspension device according to another embodiment. FIG. 4 is a view similar to FIG. 1, and FIG. 4 is a view similar to FIG. 2 of the suspension device of FIG. 3. 1... Suspension device, 2... Differential gear case, 3...
...Rear wheel, 4...Drive shaft, rear wheel,
...Wheel support member, 6...Bracket,
7...Elastic member, 12.13...Lateral link, 14...
...Road surface.

Claims (1)

[Claims] A rear wheel differential gear device that transmits driving force to the rear wheel drive shaft, and a differential gear support member that supports the differential gear device in front or behind the rear wheel drive shaft, are arranged side by side in the front-rear direction and are substantially horizontal. and two lateral links extending in the lateral direction, the lateral inner end of one of the lateral links is attached to the differential gear support member, and the inner end of the other lateral link is attached to the vehicle body. A suspension device for an automobile, wherein the differential gear support member is attached to a vehicle body via an elastic member.