JPH02212206A - Suspension of vehicle - Google Patents

Abstract

PURPOSE:To achieve a good operability and a good comfortableness simultaneously by disposing shock absorbers at the front and back of both rolling axial lines of a wheel, and setting the damping force at the time of contraction to be relatively large by the shock absorber at the front. CONSTITUTION:A wheel 32 is installed at a wheel carrier 20, and the wheel carrier 20 is supported to displace or rotate about a rotation axial line O of the wheel 32 by means of a number of arms 22-26. The arms 22-26 are connected with a vehicle body to be capable of oscillating through resiliant bushes respectively. In this case, shock absorbers 28, 30 are disposed at the front and back of the rotation axial line O in the vehicle respectively, and their lower end parts are connected with the wheel carrier 20 through ball joints 44, 46 respectively. The damping force at the time of contraction at the shock absorber 28 at the front is set larger than the damping force at the time of contraction at the shock absorber 30 at the back.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vehicle suspension, in particular a double wishbone type in which a wheel carrier is supported by an upper arm and a lower arm, and an axle housing is supported by two upper links and two wooden suspensions. Supported by the lower link of
A link type in which a lateral link absorbs lateral force, a 4-link type in which the axle housing is supported by two diagonally arranged upper links and two lower links, and the upper link also absorbs lateral force, etc. Regarding the suspension.

(Prior Art) In the above-mentioned double wishbone type, link type, or four-link type suspension, rubber or other material is used at the connection part of the arm or link (both referred to as an arm in this specification) to the vehicle body. An elastic bushing is disposed. Therefore, when the wheel carrier (including the axle housing) receives force from the road surface, it tends to displace or rotate around the rotational axis of the wheel within the range of deflection of the bushing. If this displacement can be actively utilized, the compliance in the overnight direction can be increased without changing the characteristics of the bush.

By the way, one shock absorber is usually arranged for each suspension in an independent suspension of a vehicle, or at each end of the axle housing in a suspension provided with an axle housing. In this case, the mounting location of the shock absorber is determined from the viewpoints of whether the receiver can easily hold the upper and lower blades that are added to the wheel carrier, and whether or not it will interfere with other parts.

There is also a proposal to use two shock absorbers for each suspension, and Figures 4 (Japanese Unexamined Patent Publication No. 6:112207) and Figure 5 (Japanese Unexamined Patent Publication No. 6:1-306910) are examples of this. be. This proposal also does not consider increasing the longitudinal compliance by utilizing the fact that the wheel carrier can be displaced around the rotational axis.

The suspension shown in FIG. 4 is of a so-called trailing arm type, which prevents vibration of the trailing arm due to brake reaction force. The trailing arm 10 is rigidly connected to a wheel carrier 12, and is swingably connected to the vehicle body at its front end. A shock absorber 13 and a shock absorber 14 are installed at the rear part of the wheel carrier 11 across the axis of rotation of the wheel 12.
is attached.

The suspension shown in FIG. 5 is of a double wishbone type, which increases the damping force in the sprung joint area. An upper arm 15 and a Rona arm 16 are swingably connected to a wheel carrier 17, a shock absorber 18 extends from the lower arm 16, and a shock absorber 19 located forward of the shock absorber 18 extends from the upper arm 15.

(Problem to be Solved by the Invention) In the suspension shown in Fig. 4, when the wheel rides on a protrusion on the road surface, the wheel swings around the front end of the trailing arm, but at this time, the longitudinal compliance is It does not change. If the spring constant in the longitudinal direction of the elastic bush disposed at the front end of the trailing arm is set to be soft, the longitudinal compliance can be changed by 1. However, if this is done, the alignment is likely to change due to forces from the road surface, impairing steering stability.

In the suspension shown in Fig. 5, the lower arm has particularly high rigidity, and the upper arm is bifurcated, and this support rigidity is also high, so the wheels can easily run over protrusions. At this time, substantially no displacement of the wheel carrier about the axis of rotation of the wheel occurs.

An object of the present invention is to provide a vehicle suspension that can change longitudinal compliance without changing the spring constant of a bushing provided in association with an arm.

(Means for Solving the Problems) The present invention includes a wheel carrier on which a wheel is mounted, and a plurality of arms that support the wheel carrier, and the wheel carrier is displaceable around the rotational axis of the wheel. , a suspension in which the plurality of arms are connected to the vehicle body through elastic bushings, the front shock absorber and the rear shock absorber being spaced apart from each other in the longitudinal direction of the vehicle across the axis of rotation. a shock absorber, and the damping force of the front shock absorber when it is retracted is set to be larger than the damping force of the rear shock absorber when it is retracted.

The suspension can be double wishbone, link or four link.

In either type of suspension, the arms are arranged and/or shaped such that the wheel carrier is displaced about the axis of rotation of the wheel. The elastic bushings disposed at the connection portions of each arm with the vehicle body may be the same as those conventionally used.

When the suspension is of the double wishbone type, a front shock absorber and a rear shock absorber are provided for each suspension, front and rear across the rotational axis of the wheel. Suspension is link type or 4
In the case of a link type, a front shock absorber and a rear shock absorber, which are placed across the rotational axis of the wheel, are provided at each end of the axle housing.

(Operation and Effect) When a wheel of a running vehicle rides on a protrusion and the wheel carrier receives an upward force, the front shock absorber and the rear shock absorber tend to contract. At this time, since the damping force when the front shock absorber is compressed is greater than the damping force when the rear shock absorber is compressed, the rear shock absorber contracts with a larger stroke, and eventually the wheel carrier is aligned with the axis of rotation of the wheel. Rotate around the wheel in the direction of rotation. by this,
Front and rear compliance increases.

Increasing the longitudinal compliance when riding on a protrusion or the like is equivalent to reducing the spring constant of the bushing provided in relation to the arm. therefore,
Shock can be reduced and ride comfort can be improved.

Since the bushings provided in association with the arms can have exactly the same characteristics as conventional ones, changes in alignment can be maintained in the same state as conventional ones. In other words, riding comfort is not secured at the expense of handling stability, but it is possible to achieve both.

(Example) The suspension shown in FIGS. 1 and 2 is of a double wishbone type, and the wheel carrier 20
and a plurality (three in the illustrated example) of arms 22.24.2.
6 and two shock absorbers 28.30.

The wheels 32 are of a structure known per se and are mounted on the wheel carrier 2.
Attached to O. Wheel carrier 20 is arm 2
2.24.26, the wheel 32 is supported for displacement or rotation around the axis of rotation O.

The arm 22 has an A-shaped or ■-shaped planar shape, and is connected to the wheel carrier 20 via a ball joint 34 at an end 23a that is outward in the lateral direction of the vehicle body. Two inner end portions 23b, 23 of the arm
c is swingably connected to the vehicle body via a rubber bush 36.

An arm 24 located below the arm 22 and in front of the axis of rotation 0 of the wheel consists of a substantially straight bar member. Arm 24
is connected at its outer end to the wheel carrier 20 via a ball joint 38 and at its inner end to the vehicle body via a rubber bushing 40.

Arm 2 below arm 22 and behind the rotation axis O
6 consists of a nearly straight member. The arm 26 is connected at its outer end to the wheel carrier 20 via a ball joint (not shown) and at its inner end to the vehicle body via a rubber bushing (not shown). .

A strut par 42 is connected to the wheel carrier 20. This strut par 42 extends forward or diagonally forward of the vehicle, and is swingably connected to the vehicle body via a rubber bush (not shown). The strut par 42 restricts the movement of the wheel carrier 20 in the longitudinal direction.

The shock absorbers 28 and 30 are arranged in the longitudinal direction of the vehicle across the rotational axis 0, with the shock absorber 28 located at the front and the shock absorber 30 located at the rear. The shock absorber 28 is connected to the wheel carrier 20 at its lower end via a ball joint 44, and the shock absorber 30 is connected to the wheel carrier 20 at its lower end via a ball joint 46.

Shock absorber 28 can also be connected to arm 24 and shock absorber 30 can be connected to arm 26. The upper ends of both shock absorbers are swingably connected to the vehicle body. This connection structure may be of any type known per se. The coil spring 31 is the rear shock absorber 30
This is arranged around the shock absorber 3.
0 and the vehicle body.

The damping force of the front shock absorber 28 when it is compressed is set to be larger than the damping force of the rear shock absorber 30 when it is compressed. Do this like this:

For example, the damping force of the front shock absorber 28 during contraction can be set to be greater than the damping force of the rear shock absorber 30 in all piston speed ranges.

For this purpose, two shock absorbers with different characteristics may be used.

As another example, for example, if the piston speed is 0.5 m
/s or more, the damping force of the front shock absorber 28 when compressed becomes greater than that of the rear shock absorber 30, but in a range lower than the piston speed,
It is also possible to set the damping force of both shock absorbers to be the same when they are compressed. One shock absorber is a normal shock absorber, and the other shock absorber communicates two liquid chambers in a cylinder partitioned by a piston through a bypass passage provided in the piston rod. It can be constructed by arranging a valve that opens when the speed exceeds 5 m/s.

As another example, both shock absorbers have the same characteristics, and when assembled to the vehicle body, one is positioned obliquely and the other is positioned approximately vertically.

The embodiment shown in FIG. 3 is a four-link suspension. Axle housing 50 which is a wheel carrier
is swingably supported by an upper arm 52 and a lower arm 54 at each end thereof, that is, at each side in the lateral direction of the vehicle. The front end of the upper arm 52 is swingably connected to the vehicle body via a rubber bushing 56, and the front end of the lower arm 54 is swingably connected to the vehicle body via a rubber bushing 58.

Two shock absorbers 60, 62 are arranged on each side of the vehicle, front and rear across the wheel rotation axis 0,
Each is pivotally connected to the axle housing 50. The damping force of the front shock absorber 60 when it is retracted is set to be larger than the damping force of the rear shock absorber 62 when it is retracted. This can be set as described above.

As shown in FIG. 2, when a wheel 32 of a vehicle traveling forward runs onto a protrusion 70 on the road surface, a force F is applied from the protrusion. As a result, wheel carrier 2'0 has
Wheel carrier 20 of front shock absorber 28
When the front shock absorber 28 contracts Since the damping force is larger than the damping force when the rear shock absorber 30 is compressed, the rear shock absorber 30 contracts with a larger stroke. This results in
The wheel carrier 20 rotates around the rotation axis 0, and since this rotation is in the same direction as the wheel, the rotation axis is 0. , and the connection point P moves to P. In this way, the wheel carrier rotates and
Front and rear compliance increases.

As shown in FIG. 1, when the front shock absorber 28 is arranged at an angle, a force F3 smaller than the vertical component F2 of the force F acts on the front shock absorber 28. On the other hand, a vertical force F2 acts on the rear shock absorber 30. Therefore, shock absorber 28.3
Even if the characteristics of 0 are set to be the same, the damping force of the front shock absorber 28 when it is compressed will apparently be larger than the damping force of the rear shock absorber 30 when it is compressed.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the side surface of the suspension system 1, Fig. 2 is a schematic diagram showing its function, Fig. 3 is a side view of another embodiment of the suspension, and Figs. 4 and 5 are diagrams showing the conventional suspension. 4 is a side view, and FIG. 5 is a perspective view. 20: Wheel carrier, 22.24.26.52.54: Arm, 28.30.
60.62: Shock absorber 34.36.40.5
6.58: Push.

Claims (1)

[Claims] The wheel carrier is provided with a wheel carrier on which a wheel is attached, and a plurality of arms that support the wheel carrier, and the plurality of arms are disposed through elastic bushes so that the wheel carrier is displaced around the rotational axis of the wheel. A suspension connected to a vehicle body, including a front shock absorber and a rear shock absorber that are spaced apart from each other in the longitudinal direction of the vehicle across the rotational axis,
A suspension for a vehicle, wherein a damping force of the front shock absorber when it is compressed is set to be larger than a damping force of the rear shock absorber when it is compressed.