JPH0516630A - Double-wishbone type suspension - Google Patents

Abstract

PURPOSE:To prevent a large reduction of the caster angle and the caster trail when a wheel receives a rearward force from the road surface. CONSTITUTION:An upper arm 14 and a lower arm 16 pivited to a wheel carrier at the outer ends, and pivoted to a car body at two inner ends which are separated in the front side and the rear side, through a pair of rubber bushes, are provided. One side rubber bushes 48 and 54 at the inner ends of the arms have the first chamber space 56 and the second chamber space 58 at the inner sides respectively. The first and the second chamber spaces are connected each other through a duct 10, and one side chamber space is provided at the position to receive a compression deformation when the corresponding arm is moved to move its outer end to the rear side, while the other side chamber space is provided at the position to receive a tensile deformation when the corresponding arm is moved to move its outer end to the rear side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension of a vehicle such as an automobile, and more particularly to a double wishbone type suspension.

[0002]

2. Description of the Related Art As one of the double wishbone type suspensions for vehicles such as automobiles, there is, for example, the actual breakout 62-.
As described in Japanese Patent No. 187904, a carrier that rotatably supports a wheel and an elastic bush at two inner ends that are pivotally attached to the carrier at their outer ends and are substantially separated from each other in the vehicle front-rear direction. A double-wishbone type suspension having an upper arm and a lower arm pivotally supported by a vehicle body via the vehicle is already known.

FIG. 4 is a schematic perspective view showing an example of the double wishbone type suspension as described above as a skeleton diagram. In FIG. 4, the shock absorber and the suspension spring are omitted. In FIG. 4, reference numeral 10 denotes a carrier that rotatably supports the wheel 12 around a rotation axis 12A, and reference numerals 14 and 16 denote an upper arm and a lower arm, respectively. In the illustrated example, both the upper arm and the lower arm are A-type arms.

The upper arm 14 is pivotally attached at its outer end to the upper end of the carrier 10 by a ball joint 18 and has a pair of joints 20 including rubber bushes at two inner ends which are substantially separated from each other in the vehicle longitudinal direction. , 22 pivotally about their common axis 24 to a vehicle body (not shown). Similarly, lower arm 16
Is a carrier 10 at the outer end by a ball joint 26.
Of the vehicle body by a pair of joints 28, 30 which are pivotally attached to the lower end of the vehicle and which include rubber bushes at two inner ends substantially spaced from each other in the longitudinal direction of the vehicle. Is pivoted to. The carrier 10 is integrally provided with a knuckle arm 34, and one end of a tie rod 38 is pivotally attached to the tip of the knuckle arm by a ball joint 36.

[0005]

In the conventional double wishbone suspension as described above, as shown in FIG. 5, when the vehicle is being braked, the wheels 12 have a road surface due to the braking force and the road surface unevenness. When receiving the vehicle rearward force Fb than 40, the ball joint 26 for pivoting look carrier 10 in FIG. 6 in the counterclockwise direction is the vehicle rearward force F ₁
In response to this, the ball joint 18 is displaced to the position indicated by the reference numeral 26 ', and the ball joint 18 acts as a reaction force of F ₁ to force the vehicle forward F ₂
In response to this, it is displaced to the position indicated by reference numeral 18 '. As a result, the kingpin axis 42, defined as a straight line passing through the centers of the ball joints 18 and 26, is displaced to the position indicated by the reference numeral 42 ', which reduces the caster trail Ct to Ct' and reduces the caster angle .theta.c. θc ′, which reduces the straightness of the vehicle.

Further, when the vehicle turns, as shown in FIG. 6, a cornering force Fc acts on the wheels 12, and when the vehicle turns with braking, the force component Fcb of the rearward force of the cornering force Fc is applied. However, since the same phenomenon as that described above is caused, the caster trail and the caster angle are reduced, and thus the feel of the steering wheel during turning is deteriorated.

In view of the above-mentioned problems in the conventional double wishbone suspension, the present invention prevents the caster angle and the caster trail from being greatly reduced even when the wheels receive a rearward force from the road surface of the vehicle. It is intended to provide an improved double wishbone suspension.

[0008]

SUMMARY OF THE INVENTION According to the present invention, the above object is to provide a carrier that rotatably supports wheels and a carrier that is pivotally attached to the carrier at an outer end thereof and is substantially separated from each other in the vehicle longitudinal direction. The two inner ends of the pair of elastic bushes are pivotally supported on the vehicle body by a pair of elastic bushes, and one of the pair of elastic bushes has an upper arm having a first chamber space inside and an outer end of which is pivotally attached to the carrier. The pair of elastic bushes are pivotally supported by the vehicle body through a pair of elastic bushes at two inner ends that are substantially separated from each other in the vehicle front-rear direction, and one of the pair of elastic bushes has a lower arm having a second chamber space therein. , A conduit that connects the first chamber space and the second chamber space to each other, and one of the first and second chamber spaces has a corresponding arm whose outer end moves rearward of the vehicle. When it is pivoted relative to the vehicle body, A portion provided in a portion subject to deformation, and the other of the first and second chamber spaces is subject to tensile deformation when the corresponding arm pivots relative to the vehicle body so that its outer end moves rearward of the vehicle. It is achieved by the double wishbone type suspension characterized by being provided in the.

[0009]

According to the above-described structure, one of the first and second chamber spaces undergoes compressive deformation when the corresponding arm pivots relative to the vehicle body so that the outer end of the corresponding arm moves rearward of the vehicle. The other one of the first and second chamber spaces is provided in a portion that undergoes tensile deformation when the corresponding arm pivots relative to the vehicle body so that its outer end moves rearward of the vehicle.

Further, since the first and second chamber spaces are connected to each other by the conduit, the volume of one of the first and second chamber spaces is reduced due to the compressive deformation of the corresponding elastic bush, and the internal pressure thereof is reduced. When the pressure increases, the increase in pressure is transmitted to the other of the first and second chamber spaces via the conduit, so that the other chamber space of the elastic bush corresponding to the other chamber space is provided. Undergoes tensile deformation due to expansion. On the contrary, if the volume of one of the first and second chamber spaces increases due to the tensile deformation of the corresponding elastic bush and the internal pressure decreases, the decrease in the pressure decreases the pressure in the first and second chamber spaces via the conduit. By being transmitted to the other, the portion of the elastic bush corresponding to the other chamber space in which the other chamber space is provided undergoes compression deformation due to contraction.

Therefore, when the lower arm is pivoted relative to the vehicle body so that the outer end of the upper arm moves rearward of the vehicle due to the wheel receiving a force rearward of the vehicle from the road surface, the upper arm moves the outer end rearward of the vehicle. So that the caster trail and the caster angle are reduced and reduced.

[0012]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view showing one embodiment of a double wishbone suspension according to the present invention as a skeleton diagram, and FIG. 2 is a partial cutaway of the main part of the embodiment shown in FIG. FIG. In these figures, the shock absorber and the suspension spring are omitted, and the parts corresponding to the parts shown in FIGS. 4 to 6 are designated by the same reference numerals. Is attached.

In these figures, 10 indicates a carrier for rotatably supporting the wheel 12 around a rotation axis 12A, and 14 and 16 indicate an upper arm and a lower arm, respectively. In the illustrated embodiment, the upper arm 14 is an A-shaped arm and the lower arm 16 is an L-shaped arm.

The upper arm 14 is pivotally attached at its outer end to the upper end of the carrier 10 by a ball joint 18 and has a pair of joints 20 including rubber bushes at two inner ends substantially separated from each other in the vehicle longitudinal direction. , 22 pivotally about their common axis 24 to a vehicle body (not shown). Similarly, lower arm 16
Is a carrier 10 at the outer end by a ball joint 26.
A pair of joints 28, 30 pivotally attached to the lower ends of the two and including rubber bushes at two inner ends substantially spaced from each other in the vehicle longitudinal direction so as to be pivotable about their common axis 32. It is pivoted to a car body not shown in. In the particular illustrated embodiment, the front joint 28 of the lower arm 16 is located in substantially the same lateral position as the ball joint 26.

As shown in detail in FIG. 2, the joint 22 on the rear side of the upper arm 14 extends along the axis 24 and is fixed to the vehicle body by bolts and nuts not shown in the drawing. An outer cylinder 46 concentrically arranged with respect to the inner cylinder and fixed to an inner end of a rear arm portion of the upper arm 14, and a rubber bush 48 elastically mounted between the inner cylinder and the outer cylinder. ing. Similarly, the joint 30 has an axis 32
An inner cylinder 50 that extends along the shaft and is fixed to the vehicle body by bolts and nuts not shown in the figure, and an outer cylinder 52 that is arranged concentrically with the inner cylinder and is fixed to the rear inner end of the lower arm 16. And a rubber bush 5 mounted between the inner cylinder and the outer cylinder.
4 and.

In the illustrated embodiment, a rubber bush 48.
Has a first chamber space 56 inside, and the rubber bush 54 has a second chamber space 58 inside. First room space 5
6 is provided on the inboard side of the inner cylinder 44, and the second chamber space 58 is provided on the outboard side of the inner cylinder 50. The chamber spaces 56 and 58 are connected to each other by a conduit 60, and the chamber spaces and the conduits are filled with oil which is an incompressible fluid.

The joints 20 and 28 are constructed in the same manner as the joints 22 and 30 except that no room space is provided.

In the embodiment constructed as described above, FIG.
When a force F ₁ directed rearward of the vehicle acts on the ball joint 26 at the outer end of the lower arm 16 as shown in FIG. 5, the lower arm pivots relative to the vehicle body in the direction in which the ball joint 26 is displaced rearward, and the rubber bush 54 is subjected to compressive deformation at a portion on the outboard side of the inner cylinder 50. Therefore, the pressure in the second chamber space 58 is increased and a part of the oil in the second chamber space moves to the first chamber space 56 via the conduit 60, and the volume of the chamber space is increased. Thus, when the volume of the first chamber space 56 is increased, the outer cylinder 46 is displaced in the inboard direction relative to the inner cylinder 44, and the upper arm 14 is moved clockwise relative to the vehicle body as seen in FIG. As a result, the ball joint 18 is also displaced rearward under the force F ₂ directed rearward of the vehicle.

Therefore, as shown in FIG. 3, the kingpin shaft 42 is displaced to the position indicated by the reference numeral 42 ', and the caster trail Ct and the caster angle .theta.c are smaller than those in the conventional case shown in FIG. The degree of reduction is reduced, which reduces or avoids deterioration of straightness of the vehicle and deterioration of the feel of the steering wheel when turning.

In the above embodiment, the first chamber space 5
6 is provided on the inboard side with respect to the inner cylinder 44 of the rubber bush 48, and the second chamber space 58 is provided on the outboard side with respect to the inner cylinder 50 of the rubber bush 54. The arm corresponding to one of the arms is provided at a portion which undergoes compressive deformation when pivoted relatively to the vehicle body so that the outer end of the arm moves rearward of the vehicle, and the arm corresponding to the other chamber space has the outer end thereof rearward of the vehicle. It may be provided at any portion as long as it is provided at a portion that undergoes tensile deformation when pivoted relative to the vehicle body so as to move.

For example, the first chamber space 56 has a joint 20.
It may be provided on the outboard side with respect to the inner cylinder of the rubber bush. The first chamber space 56 may be provided on the outboard side of the inner cylinder 44 of the rubber bush 48, and the second chamber space 58 may be provided on the inboard side of the inner cylinder 50 of the rubber bush 54. Further, both chamber spaces 56 and 58 may be provided in the front joints 20 and 28,
Especially, the inner end on the rear side of the lower arm 16 has the ball joint 2
6 in a lateral position substantially the same as 6 and the front inner end of the lower arm is in front of it, the second chamber space 58
May be provided on the inboard side with respect to the inner cylinder of the rubber bush of the joint 28.

The chamber spaces 56, 58 and the conduit 60 are preferably filled with an incompressible fluid as in the above-mentioned embodiment, but the fluid filled in these is a compressible fluid such as air. Good.

Further, in the illustrated embodiment, the inner ends of the upper and lower arms are fixed to the outer cylinders of the corresponding joints, but at least one of the inner ends of these arms is the inner cylinder of the corresponding joints. The axis of the joint at the inner end of at least one of the arms may extend in the vertical direction.

Although the present invention has been described above in detail with reference to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art that it is possible.

[0026]

As is apparent from the above description, according to the present invention, the lower arm is moved relative to the vehicle body so that the outer end of the lower arm is moved rearward of the vehicle when the wheel receives a rearward force from the road surface. When pivoted, the upper arm is pivoted relative to the vehicle body so that the outer end of the upper arm moves rearward of the vehicle.Therefore, the caster trail and caster angle are large even when the wheels receive a vehicle rearward force from the road. It is possible to prevent the reduction of the amount, and thereby to prevent the deterioration of the straightness of the vehicle and the feeling of the steering wheel when turning.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing, as a skeleton diagram, one embodiment of a double wishbone suspension according to the present invention.

FIG. 2 is a plan view showing a main part of the embodiment shown in FIG. 1 with a part thereof cut away.

FIG. 3 is a schematic side view showing changes in caster angle and caster trail that occur when a wheel receives a vehicle rearward force from a road surface in the illustrated embodiment.

FIG. 4 is a schematic perspective view showing an example of a conventional double wishbone suspension as a skeleton diagram.

FIG. 5 is a schematic side view showing changes in caster angle and caster trail that occur when a wheel receives a vehicle rearward force from a road surface in a conventional double wishbone suspension.

FIG. 6 is a schematic plan view showing a cornering force generated when a vehicle turns in a conventional double wishbone suspension and a vehicle rearward force resulting therefrom.

[Explanation of symbols]

 10 ... Carrier 14 ... Upper arm 16 ... Lower arm 18 ... Ball joint 20,22 ... Joint 26 ... Ball joint 28,30 ... Joint 48,54 ... Rubber bush 56 ... First chamber space 58 ... Second chamber space 60 ... Conduit

Claims (1)

Claim: What is claimed is: 1. A carrier for rotatably supporting a wheel, and a pair of two inner ends which are pivotally attached to the carrier at outer ends thereof and are substantially separated from each other in the vehicle longitudinal direction. An upper arm having a first chamber space therein and one of the pair of elastic bushes pivotally supported by the vehicle body through an elastic bush of the upper bush and an outer end of the upper arm that are pivotally attached to the carrier and are substantially separated from each other in the vehicle longitudinal direction. One of the pair of elastic bushes is pivotally supported on the vehicle body by a pair of elastic bushes at the two inner ends of the lower arm having a second chamber space therein, the first chamber space and the first chamber space. A conduit for communicating with the second chamber space, and one of the first and second chamber spaces is pivoted relative to the vehicle body so that the outer end of the corresponding arm moves rearward of the vehicle. It is provided at the site that receives compression deformation when moved, Note that the other of the first and second chamber spaces is provided in a portion that undergoes tensile deformation when the corresponding arm pivots relative to the vehicle body so that the outer end of the corresponding arm moves rearward of the vehicle. Double wishbone suspension.