JPH02306805A - Suspension device of vehicle - Google Patents

Abstract

PURPOSE:To prevent deterioration of riding comfortableness by disposing a coil spring off of a vertical surface including a wheel rotating axial line in such a manner as to satisfy a determined condition to suppress the generation of vehicle weight moment when the coil spring is supported by either one of two lower arms in a double wishbone type suspension device. CONSTITUTION:A point O on which a line l2 parallel to a line l1 connecting the vehicle body side connecting parts 23b, 23c of an upper arm 22 and passing the connecting part 23a between the upper arm 22 and a wheel carrier 20 crosses a vertical surface P including the rotating axial line C of a wheel 32 is determined. A coil spring 28 is installed in such a manner that a line l3 connecting the center point of the connecting part 25a between a lower arm 24 for supporting the coil spring 28 and the wheel carrier 20 with the crossing point O is parallel to the axial line l4 of the coil spring 28. According to this constitution, generation of vehicle weight moment can be suppressed to prevent addition of pre-load to a lower arm mounting bush, and deterioration of riding comfortableness can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a suspension system of a double wishbone type of a vehicle, particularly suitable for suspending drive wheels.

(Prior Art) As shown in FIG. 3.4, a device for suspending a double wishbone drive wheel includes a wheel carrier 10 that supports a wheel 11, and a wheel carrier 10 that supports a wheel 11, An upper arm 12 is swingably connected to a portion of the wheel carrier 10 that is pivotable to a portion of the wheel carrier 10 that is spaced downward from the upper arm 12 and is swingably connected to a portion of the wheel carrier 10 that is forward and rearward of the vehicle body from the rotation axis C. and a lower arm 13.14 which is possibly connected to the lower arm 13.14.

The wheels 11 are driven by a drive shaft 15, and a coil spring 16 is supported by a front lower arm 13 to avoid interference with the drive shaft.

Incidentally, as a similar technique, there is a suspension system described in Japanese Patent Application Laid-Open No. 62-94406.

(Problem to be Solved by the Invention) When the vehicle weight W is applied to the wheel, since the coil spring 16 is HIJu forward from the vertical plane P including the rotation axis C of the wheel, a moment of M=WH is applied to the wheel carrier 10. to work. As a result, a preload is applied to the lower arm 14.

The rubber bushing disposed at the connection portion of the lower arm 4 with the vehicle body, which also has the function of receiving loads in the longitudinal direction, is generally set to have load-deflection characteristics as shown in FIG. Therefore, when no preload is applied to the bushing, k
The spring constant of o, that is, the stiffness, becomes , when the preload P is applied, the stiffness increases and the riding comfort deteriorates.

An object of the present invention is to suppress the generation of a vehicle weight moment due to the bias when the coil spring is disposed in the na direction or rearward from the vertical plane containing the rotational axis of the wheel, and to prevent preload from being applied to the bush when the lower arm is attached. Make sure that there is no
The purpose is to prevent deterioration of riding comfort.

(Means for Solving the Problems) The present invention includes a wheel carrier that rotatably supports a wheel, and a wheel carrier that is swingably connected to a portion of the wheel carrier that is above the rotational axis of the wheel, and that is attached to a vehicle body. An upper arm is swingably connected to two parts, and the wheel carrier is swingably connected to two parts, which are forward and rearward of the vehicle body from the rotational axis of the wheel and below the upper arm. A suspension system for a vehicle, comprising two lower arms, and a coil spring disposed biased toward the front or rear of a vertical plane containing the rotational axis of the wheel and supported by one of the two lower arms, the suspension system comprising: parallel to the straight line connecting the center points of the two connecting parts with the editorial body of the upper arm and
A straight line connecting the point where a straight line passing through the center point of the connection part of the wheel carrier intersects the vertical plane and the center point of the connection part of the lower arm with the wheel carrier on which the coil spring is supported is The coil spring is arranged substantially parallel to the axis of the spring.

(Function and Effect) The reaction force of the vehicle weight is parallel to the vertical plane including the wheel rotation line and the straight line connecting the center points of the two connections on the vehicle body side of the upper arm, and At the intersection with the straight line passing through the center point of the section,
From the intersection point, the force is resolved into component forces directed toward the center point of the connection part of the lower arm supporting the coil spring with the wheel carrier, and the center point of the connection part of the upper arm with the wheel carrier. As a result, the former force is applied by the coil spring,
Further, the latter component force is stopped by the upper arm, and no preload is applied to the lower arm without the coil spring.

Since no preload is applied to the lower arm without a coil spring, the rigidity of the rubber bushing disposed at the connection portion of the lower arm with the vehicle body is maintained at a low level, thereby preventing deterioration of riding comfort.

Generally, the coil spring is arranged to surround the shock absorber, but as a result of supporting the coil spring on the lower arm, the upper end of the shock absorber can be mounted as low as possible on the vehicle body side. There is no need to provide a separate tower for shock absorber installation. Even if a tower is installed for installation, the height of the tower will be sufficiently low compared to the height of the tower when the lower end of the shock absorber is connected to the wheel carrier, which will reduce the weight increase and It becomes easier to ensure rigidity on the vehicle body side.

(Example) As shown in FIG. 1, the suspension system includes a wheel carrier 2
0, upper arm 22, and two lower arms 24.2
6 and a coil spring 28.

The wheel carrier 20 rotatably supports the wheel 32.)
do. This wheel 32 is driven by a drive shaft 34.

In the illustrated embodiment, the upper arm 22 has a planar shape of A.
It is V-shaped and has an outer end 23a and two inner ends 23b and 23c spaced apart from each other. At a portion of the wheel carrier 20 where the outer end 23a is above the rotational axis C (FIG. 2) of the wheel 32,
They are swingably connected by a ball joint 36.

The two inner ends 23b and 23c of the upper arm 22 are swingably connected to the vehicle body via rubber bushings (not shown). Note that in this specification, the term "vehicle body" includes the suspension member.

The lower arm 24 is a straight, so-called summer-type arm, and has an outer end 25a and an inner end 25b. As shown in FIG. 2, the outer end 25a is located at a portion of the wheel carrier 20 that is spaced downward from the upper arm 22 and biased forward from the rotation axis C of the wheel 32.
They are pivotally connected via a rubber bush (not shown). The inner end 25b of the lower arm 24 is swingably connected to the vehicle body via a rubber bush (not shown).

The lower arm 26 is arranged behind the lower arm 24 and diagonally with respect to the vehicle body, and is a straight summer-type arm. The lower arm 26 has a front end 71527a and a rear end 27b. The front end 27a is spaced downward from the upper arm 22, as shown in FIG.
In addition, it is swingably connected to a portion of the wheel carrier 20 that is deviated rearward from the rotation line C of the wheel 32 via a rubber bush (not shown). The rear end 27b of the lower arm 26 is formed as an eye, and a rubber bush 40 is attached to the eye. The end portion 27b on the 1 side is swingably connected to the vehicle body via a bush 40.

The coil spring 28 is arranged so as to surround the shock absorber 30. That is, the shock absorber 30 is connected to the vehicle body at its upper end, and its lower end is swingably connected to the lower arm 24 via a ball joint (not shown), and the coil spring 28 is connected to the shock absorber 30 at its upper end. It is arranged to surround the absorber 30. coil spring 28
The upper and lower ends of the shock absorber 30 are hooked into spring receivers of a structure known per se, which are provided in connection with the shock absorber 30.

As a result of supporting the coil spring 28 on the lower arm 24 via the shock absorber 30, the coil spring 28 is supported on the wheel 32.
It is located biased toward the front of the vertical plane P that includes the rotation axis C of the. This coil spring 28 is attached as follows.

That is, the two connecting portions 2 of the upper arm 22 with the vehicle body
A straight line connecting the center points of 3b and 23c! , and a connecting portion 23 of the upper arm 22 with the wheel carrier 20
Point 0 where the straight line 12 passing through the center point of a intersects the vertical plane P
A straight line 13 connecting the axis 2. The coil spring 28 is arranged so as to be substantially parallel to.

When the vehicle weight W is applied manually to the wheels 32, a reaction force W' is generated at the intersection 0 of the straight line nxy and the vertical plane P, as shown in FIG. Then, the upper arm 22 is in a straight line 1. Because the component force W1 is on the straight line 12 and the straight line 23
A component force W'2 is generated. However, since the straight line J23 is substantially parallel to the axis 14 of the coil spring 28, the component force W'2 of the straight line 23 is canceled out by the spring force of the coil spring 28. Therefore, even if the coil spring 28 is deviated from the vertical plane P, no moment of vehicle weight is generated due to the deviation, and no preload is applied to the lower arm 26. Therefore, the bushing 40 disposed on the lower arm 26 is maintained at the rigidity shown in FIG. 5, and the riding comfort is not deteriorated.

In addition, in the above embodiment, the upper arm 22 is
Although it is a type arm, two summer type arms can be used instead of a knead type arm. In this case, the two arms are spaced apart from each other in the front and back, and the straight line connecting the center points of the connecting parts with the vehicle body is J2. The straight line connecting the center points of the connection parts with each wheel carrier 20 is IL2.
Arrange the two arms so that

Although the present invention is suitable for suspension of drive wheels as in the embodiment, it can also be implemented when the drive wheels are located at the front wheels and are simultaneously steered, or when the drive wheels are located at the rear wheels and cannot be steered.

[Brief explanation of drawings]

Figure 1 is a plan view of the suspension system, Figure 2 is a schematic side view, Figures 3 and 4 are schematic diagrams of a conventional suspension system, Figure 3 is a perspective view, and Figure 4 is a schematic diagram of a conventional suspension system. The side view, FIG. 5, is a characteristic diagram of a bushing provided in relation to the lower arm. 20: Wheel carrier, 22 Near shoulder arm, 24.26: Lower arm, 28: Coil spring, 30: Shock absorber, 40: Push

Claims (1)

[Claims] a wheel carrier rotatably supporting a wheel; and one of the wheel carriers above the rotational axis of the wheel.
an upper arm that is swingably connected to two parts of the vehicle body, and an upper arm that is swingably connected to two parts of the vehicle body; and the wheel carrier that is located forward and rearward of the vehicle body from the rotation axis of the wheel and below the upper arm. Two lower arms each swingably connected to two parts,
A suspension system for a vehicle, comprising a coil spring biased toward the front or rear of a vertical plane containing the rotational axis of the wheel and supported by one of the two lower arms, the suspension system comprising: A point where a straight line that is parallel to the center point of the two connecting parts and passes through the center point of the connecting part of the upper arm with the wheel carrier intersects the vertical plane, and a point of the lower arm on which the coil spring is supported. A suspension system for a vehicle, wherein the coil spring is arranged such that a straight line connecting a center point of a connecting portion with the wheel carrier is substantially parallel to an axis of the coil spring.