JPS5914249Y2 - Automotive drive wheel suspension system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structural improvement of a suspension system for a drive wheel of an automobile.

Generally, in the suspension system of a rear wheel drive vehicle, a differential gear system is generated by supporting a differential gear system on a mount member in the vehicle width direction and connecting the mount member to the vehicle body side via a rubber mount. In addition to preventing vibrations from being transmitted directly to the vehicle body, the wheel support member that rotatably supports the rear wheels is connected to the mount member via a suspension link to prevent road vibrations from the rear wheels from being directly transmitted to the vehicle body. A support structure is known from Japanese Utility Model Publication No. 50-15288.

However, in the above conventional drive wheel suspension structure,
When a lateral force acts on the drive wheel when cornering a car or due to a crosswind, a component of the lateral force acts on the rubber mount of the mount member through the suspension link, causing the rubber mount to deform, and this deformation causes the drive wheel to There has been a problem in that running stability deteriorates as a result of the wheels being displaced from their normal positions.

The present invention was developed to solve this problem, and by making the installation positions and spring constants of each rubber mount of the front and rear mount members different with respect to the drive wheel, the drive wheel is stabilized against lateral forces. It is an object of the present invention to provide a drive wheel suspension system for a motor vehicle, which can maintain stable driving performance even when cornering or facing a crosswind.

In other words, in the present invention, the distance of the rubber mount on the front mount member side from the drive wheel axis is set larger than that on the rear mount member side, and with this setting, a larger component force is generated when a lateral force is applied. The basic idea is that the hardness of the rubber mount on the rear mount member side that receives the load, in other words, the spring constant, is set to a large value so that it can receive a large amount of force without excessive deformation, thereby preventing the drive wheel from tilting. It is a characteristic feature.

Hereinafter, the present invention will be described in more detail with reference to the illustrated embodiments.

In Fig. 1, 1 and 1 are a pair of chassis frames on both sides extending in the longitudinal direction of the vehicle body, and 2 and 2 are chassis frames 1 and 2, respectively.
, left and right rear wheels independently suspended on the outside of 1, 3 an input shaft 6 connected to a propeller shaft 4 via a universal joint 5, and left and right drive shafts that drive the rear wheels 2, 2. The front part of the casing 8 of the device 3 is fixed to the center of the front mount member 9, the rear part is fixed to the center of the rear mount member 10, and the front part of the casing 8 of the device 3 is fixed to the center of the rear mount member 10. It is supported by the chassis frame 1°1 by a member 9 and a rear mount member 10.

Above front mount member 9, rear mount member 1
As shown in FIG. 3, each end of 0 is elastically coupled to the chassis frame 1 side by being attached to the outer periphery of the mount rubber 12 of the rubber mount 11 fixed to the chassis frame 1 with bolts. There is.

Again in FIG. 1, reference numeral 14.14 denotes a wheel support member whose bearing supports the axle of the rear wheels 2, 2 connected to the drive shaft, and 15.15 denotes a front side portion of each wheel support member 14. A front lateral link 1 connects a pair of bracket parts 9a provided near the center of the front mount member 9;
6.16 is a lateral link that connects the rear side portion of each wheel support member 14 and the central portion of the rear mount member 10; rubber mound) lla, l
The trailing links are connected to the chassis frames 1, 1 in front of the lb, and the connections at each end of each of these links 15, 16, 17 are, for example, as shown in FIG. This is done by fitting each end to the outer periphery of a rubber bush 20 of a rubber mount 19 supported by bolts between brackets 18.

As shown in FIG. 2, the wheel support member 14.14 is
It is connected and supported by the lower end of the strut 22 in the vertical direction, and is elastically supported by a coil spring 23 provided on the strut 22 and a mount rubber 25 supported on the strut tower 24.

In the above drive wheel suspension structure, in the present invention, the mass, the rubber mount on the front mount member 9 side) 11a
, 11 b and the axes of the drive wheels 2, 2, the distance 11 between the rubber mount 11 C, 1 on the rear mount member 10 side.
1d and the axes of the drive wheels 2, 2, so that the front side and rear side rubber mounts 11 are larger than the distance 12 between
Set the installation positions of a, 11 b, 11 c, and 11 d.

Therefore, for example, when a lateral force P acts on the right drive wheel 2, the front rubber mount 11a,
The component force acting on the rear rubber mount 11 d is Fl,
If it is F2, obviously F2>Fl, and the rear rubber mount 11 d is the front rubber mount) 1
1 Receives a larger force compared to a.

For this reason, the stiffness of the mount rubber is set to be larger than that of the front rubber mount 11a, and a large force is applied to the spring constant of the rear rubber mount 11d. Front side bar mount that prevents excessive deformation of the rubber mount and receives smaller force by receiving it with rubber) 11
The deformation amount should be approximately equal to or slightly smaller than the deformation amount of a.

As a method of varying the hardness of the mount rubber, the material of the rubber itself may be varied, or the method of press-fitting the mount rubber may be varied.

As mentioned above, the front rubber mount 11a, ll
The installation distance 11 of b is the rear rubber mount 11C, 11
If it is set larger than the installation distance 12 of d, the windup vibration frequency caused by the differential gear device 3 can be made lower than the frequency of vehicle body vibration in the normal driving range, and resonance with the vehicle body can be avoided. It is also advantageous in that it can be

In this case, the windup rigidity when the center of gravity of the differential gear device 3 and the axis of the drive wheel 2 substantially coincide with each other is determined by the following equation.

K = 1 x 112 + k2X 1□' 1: Spring constant of front rubber mount 2: Spring constant of rear rubber mount.

Also, the lateral rigidity of the suspension system is 1+2.

When l and k are constant, the windup stiffness can be replaced by the following equation.

K=k ((-L) 2- (L-')'' Therefore,
The windup stiffness K is maximum when 11==1, that is, when 11 and 12 are equal.

Here, the frequency f of windup vibration is expressed by the following formula % formula %: Therefore, in order to lower the frequency, the windup stiffness K
It is necessary to lower the distance, and for this purpose, it is known that it is better to make 11 longer than the ground, that is, 11 longer than 12, from the layout of the vehicle.

The reason why it is better to make 11 longer in terms of layout is as follows.

That is, the center of gravity of the differential gear device 3 is located in front of the axis of the drive wheels 2 because the propeller shaft is disposed in the front side.

In this case, considering weight distribution, it would be better to make the front side longer.

Further, since parts such as a gasoline tank are usually arranged on the rear side of the differential gear device 3, it is preferable to make the front side longer from this point of view as well.

In addition, although the case where the center of gravity of the differential gear device 3 and the axis of the drive wheel 2 almost coincide with each other has been described above, if they do not coincide, the windup rigidity will be affected by the amount of deviation. The value becomes larger by a certain value, but as above, 1
It is obtained as a quadratic function of , and is maximum at 14, so there is essentially no difference.

In addition, in order to further shift the windup vibration to the lower frequency side, the front rubber mounts 11a, 11
It is better to attach the balance weight 27 to b.

In addition, as shown in Figure 5, the trailing link (first
It goes without saying that the present invention can also be applied to a suspension structure in which the stabilizer 28 (see FIG. 17) is also used as the well-known stabilizer 28.

The embodiment shown in FIG. 5 is not different from the embodiment shown in FIG. 1 in other respects, so the same parts are given the same numbers and redundant explanation will be omitted.

In addition, the rubber mount has an annular partition in the center.
It is also possible to use a mount rubber that is divided into two parts, an inner and an outer part.

As is clear from the above explanation, the present invention has the advantage that the front rubber mount is installed farther from the axis of the drive wheel than the rear rubber mount, while the rear rubber mount is hardened. The present invention provides a drive wheel suspension system for an automobile, characterized in that the stiffness of the front rubber mount is set to be harder than that of a front side rubber mount.

According to the present invention, it is possible to deform the front and rear rubber mounts almost equally in response to lateral forces.
It is possible to support the drive wheels without changing their directionality, improving running stability, and increasing the lateral rigidity of the suspension system, reducing the wind-up vibration frequency and improving performance in the normal driving range. It is possible to obtain the effect that the resonance with the vehicle body can also be reduced.

[Brief explanation of drawings]

Fig. 1 is an explanatory plan view showing the automobile drive wheel suspension system according to the present invention, Fig. 2 is an explanatory side view of the same, Fig. 3 is a cross-sectional view of the rubber mount of the mount member, and Fig. 4 is the rubber of the suspension link. A cross-sectional view of the mount and FIG. 5 are explanatory plan views showing another embodiment of the present invention. 1.1...Frame, 2,2...Drive wheel, 8...
Differential gear case, 9...Front mount member, 1
0... Rear mount member, 11 a, 11 b.
...Front side rubber mount, 11C111d...
Rear rubber mount.

Claims (1)

[Scope of utility model registration request] In a suspension system for a drive wheel of an automobile, a front mount member and a rear mount member that support the front and rear of a differential gear case are supported on the vehicle body via a rubber mount,
The distance between the drive wheel axis and the front rubber mount is set longer than the distance between the drive wheel axis and the rear rubber mount, and the hardness of the rear rubber mount is set to be harder than the front rubber mount. A drive wheel suspension system for an automobile, characterized in that a wheel support member rotatably supporting the drive wheel is connected to the front and rear mount members by suspension links.