GB2176158A

GB2176158A - Independent rear suspension for use on motor vehicles

Info

Publication number: GB2176158A
Application number: GB08613369A
Authority: GB
Inventors: Nobuyoshi Asanuma; Kanji Kubo; Keiichi Mitobe
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 1985-06-03
Filing date: 1986-06-03
Publication date: 1986-12-17
Also published as: JPH0581443B2; GB8613369D0; FR2582591B1; FR2582591A1; DE3618563C2; GB2176158B; JPS61278408A; DE3618563A1

Abstract

An independent rear suspension includes a knuckle 1 having a spindle 11 for supporting a wheel 2, the spindle having a central axis C, a trailing arm 6 coupled to the knuckle, a pair of spaced lower arms 3, 4 pivotally mounted on the knuckle, a knuckle arm 12 extending substantially upwardly from the knuckle, an upper arm 5 pivotally mounted on the knuckle arm, and a damper 8 having a lower end 82 coupled to the knuckle at a position below the central axis of the spindle, the damper having a lower portion 81 disposed between the spaced lower arms and in the vicinity of the central axis of the spindle. <IMAGE>

Description

SPECIFICATION Independent rear suspension for use on motor vehicles The present invention relates to an independent rear suspension including atrailing arm,foruseona motor vehicle, and more particularly to a damper attachment structure for such an independent rear suspension.

Japanese Laid-Open Patent Publication No.

60-92106 published on May 1985 discloses an independent rear suspension for use on a motor vehicle. The disclosed independent rear suspension generally comprises a knuckle for supporting a wheel, a trailing arm coupled to the knuckle, a pair of front and rear lower arms coupled to the knuckle, and an upper arm coupled to a knuckle arm extending upwardly from the knuckle. This prior independent rear suspension is functionally equivalent to the so-called double wishbone suspension. Adamperor shock absorber has its lower end attached to the knuckle adjacent to the lower arms such that the damper lower end is offset or displaced in the fore-and-aft direction of the motor vehicle from the centre of the wheel when viewed in side elevation.

This is undesirable from the standpoint of damper performance since, when the wheel is moved vertically during travel of the motor vehicle, the damper lower end is subjected to a twisting moment commensurate with the extent by which the damper lower end is displaced from the wheel centre. In addition, an elastic bushing interposed between the upper end of the damper and the vehicle body undergoes undue external forces when the wheel is moved vertically. The knuckle and the lower arms are required to be of a large mechanical strength in order to withstand the twisting moment imposed on the damper lower end, resulting in increased weights of the suspension components.

According to the present invention there is provided an independent rear suspension for a motor vehicle, comprising a knuckle having a spindle for supporting a wheel rotatablythereon, the spindle having a central axis, a trailing arm coupled to said knuckle, a pair of spaced lower arms pivotally mounted on said knuckle, a knuckle arm extending substantially upwardly from said knuckle, an upper arm pivotally mounted on said knuckle arm, and a damper having a lower end coupled to said knuckle at a position below the central axis of said spindle, said damper having a lower portion disposed between said spaced lower arms and in the vicinity of said central axis of said spindle.

Preferably the lower portion of the damper is located substantially in alignment with the central axis ofthe spindle when viewed in side elevation.

Preferably the knuckle has a damper attachment leg extending substantially downwardly therefrom below the central axis ofthe spindle, the lower end of the damper being pivotally coupled to the damper attachment leg.

With this arrangement, the space between the lower arms is effectively utilized by positioning the dampertherein. Since the lower portion ofthe damper is substantially aligned with the central axis ofthe spindle, no appreciable twisting moment is applied to the damper, and hence the damper and elastomeric bushings on its upper end can effectively perform their function while the suspension is in operation. Inasmuch as no substantial twisting forces are imposed on the damper, the components of the suspension are not required to increase their mechanical strength against such twisting forces.

Therefore, the suspension can be lightweight. The stroke of the damper is increased because the lower end ofthe damper is coupled to the damper attachment leg disposed below the central axis ofthe spindle.

An embodiment ofthe invention will now be described byway of example and with reference to the accompanying drawings, in which: Figure lisa perspective view of an independent rear suspension according to the present invention; and Figure2 is a rearelevational viewofthe independent rear suspension of Figure 1 with a wheel rotatably mounted thereon.

As shown in Figures 1 and 2, an independent rear suspension for a motor vehicle according to the present invention includes a knuckle 1 having a spindle 11 projecting outwardly from an outer surface thereof. Awheel 2 including a tyre 2a is rotatably supported on the spindle 11. The suspension also includes front and rear lower arms 3, spaced from each otherandextendingtransverselyacrossthe longitudinal orfore-and-aft direction of the motor vehicle, the lower arms 3,4 having outer ends 3a, 4a (left ends in Figure 2) pivotally coupled to opposite sides ofthe knuckle 1. The respective inner ends 3b, 4b of the lower arms 3,4 are pivotally coupled through elastomeric bushings 31,41, respectively, to a crossbeam 7a of the vehicle body.

From an upper rear end of the knuckle 1, there extends upwardly a knuckle arm 12 with its upper portion extending rearwardly (toward the viewer of Figure2) and outwardly (to the left in Figure 2).An upper arm 5 has an outer end 5a pivotally coupled to the upper end 1 2a of the knuckle arm 12 through a ball-and-socketjoint 1 2a. The inner end 5b of the upper arm 5 is pivotally connected to a bracket7b through an elastomeric bushing 51 by a pivot rod 52 fixed to the bracket 7b which is secured to a wall of a wheel house accommodating the wheel 2.

As shown in Figure 1,the knuckle has a pairof upper and lower joint arms 1 3a, 13b extending forwardly from a front side of the knuckle 1. The suspension includes a trailing arm 6 extending in the longitudinal direction of the motor vehicle and lying in a vertical plane. The trailing arm 6 has a pair of upper and lower joint arms 61 a, 61 b fastened respectively to the joint arms 13a, 1 3b of the knuckle 1 by means of bolts 63. The trailing arm 6 has a front end 61 c pivotally mounted on a vehicle body member (not shown) through an elastomeric bushing 62. The trailing arm 6 is made of a leaf spring material which is highly rigid against bending stresses applied along its plane, and which is sufficiently resilient under forces imposed across its plane.

A damper attachment leg 14 projects downwardly and inwardlyfrom the lower end ofthe knuckle 1, and lies substantially immediately beneath the central axis C of the wheel 2, i.e., the spindle 11 (hereinafter referred to as a "wheel centre C"), when viewed in side elevation. A hydraulic damper or shock absorber 8 is positioned inwardly ofthe knuckle 1 and has a lower portion 81 disposed between the front and rear lower arms 3,4. The lower end 82 ofthe damper8 is pivotally mounted on the damper leg 14through an elastomeric bushing 83. The upper end 84 of the damper8 is coupled through elastomeric bushings 85 to a vehicle body member (not shown) such thatthe lower portion 81 of the damper 84 lies substantially in alignment with the wheel centre C when viewed in side elevation.

With the damper8 disposed between the lower arms 3,4 and the lower portion 81 thereof substantially aligned with the wheel centre C, the damper8 is substantiallyfree from a twisting momentwhen the wheel 2 is vertically moved during travel ofthe motor vehicle. Therefore, the damper 8 and the elastomeric bushing 85 are capable ofwell performing theirfunction during operation ofthe suspension. The suspension components are not required to increasetheir mechanical strength to withstand the twisting momentwhichwould otherwise be imposed on them,and hencethe suspension is reduced in weight.

Since the lower end 82 ofthe damper 8 is mounted on the damper attachment leg 14 located belowthe wheel centre C, a sufficiently long stroke is available forthe damper 8.

It will thus be seen that the present invention, at least in its preferred forms, proivdes an independent rear suspension for motorvehicles which includes a damper disposed between front and rear lower arms and coupled to a knuckle for eliminating a twisting moment on the damper lower end, thus reducing the weight of the suspension, and also providing an increased strokeforthe damper.

It isto be clearly understood thatthere are no particular features of the foregoing specification, or of any claims appended hereto, which are at present regarded as being essential to the performance ofthe present invention, and that any one or more of such features or combinations thereof maytherefore be included in, added to, omitted from or deleted from any of such claims if and when amended during the prosecution ofthis application or in the filing or prosecution ofanydivisional application based thereon.

Claims

1. An independentrearsuspensionfora motor vehicle, comprising: a knuckle having a spindleforsupporting awheel rotatably thereon, said spindle having a central axis; atrailing arm coupled to said knuckle; a pair of spaced lower arms pivotally mounted on said knuckle; a knuckle arm extending substantially upwardly from said knuckle; an upperarm pivotally mounted on said knuckle arm; and a damper having a lower end coupled to said knuckle at a position below the central axis of said spindle, said damper having a lower portion disposed between said spaced lower arms and in the vicinity of said central axis of said spindle.

2. An independentrearsuspension according to claim 1 ,wherein said lower portion of said damper is located substantially in alignment with said central axis of said spindle when viewed in side elevation.

3. An independent rear suspension accordingto claim 1 or 2, wherein said knuckle has a damper attachment leg extending substantially downwardly therefrom below said central axis of the spindle, said lower end of said damper being pivotally coupled to said damper attachment leg.

4. An independent rear suspension fora motor vehicle,substantiallyas hereinbefore described with reference to the accompanying drawings.