GB2206086A

GB2206086A - Vehicle wheel suspension arrangement

Info

Publication number: GB2206086A
Application number: GB08714930A
Authority: GB
Inventors: Edward Kenneth Laban
Original assignee: Jaguar Cars Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 1987-06-25
Filing date: 1987-06-25
Publication date: 1988-12-29
Also published as: GB8714930D0

Abstract

A suspension assembly for a vehicle comprises a support member such as a wishbone (2) pivotally mounted relative to the body (1) of the vehicle. A spring (3) acts between the support member and a spring mount which is fixed relative to the body of the vehicle and a vibration compensating device such as a damper (6) acts between the support member and a mount, which is fixed relative to the body of the vehicle. The spring (3) is dimensioned such that at least one of its end portions has a greater diameter than the mid-portion thereof which makes it possible to position a damper (6) closer to the spring than would otherwise be possible and also makes it possible to position the spring closer to the line of action of the wheel centre line than would otherwise be possible by permitting the axis of the spring to be positioned closer to the drive shaft. <IMAGE>

Description

SUSPENSIO! ASSEI:.BLY FOR VEHICLES The present invention relates to a suspension assembly for vehicles.

A suspension assembly for a vehicle generally comprises a wishbone which is mounted pivotally on a subframe or body portion of the vehicle and which carries directly or indirectly a wheel, a spring acting between the wishbone and the subframe or body of the vehicle, and a vibration compensating device such as a danper also mounted between the subframe or body and which damps out oscillations in the spring.

Suspension assemblies are known in many different configurations. However, a problem commonly encountered is a lack of space. This problem is often exacerbated because the spring when compressed bulges and deflects and requires more working space than would appear from the diameter of the spring.

It is an object of the present invention to provide a suspension assembly for a vehicle which makes better use of the space available.

According to the present invention there is provided a suspension assembly for a vehicle comprising a support ember pivotally mounted relative to the body of the vehicle, a spring acting between the support member and a spring mount which is fixed relative to the body of the vehicle, and a vibration compensating device acting between the support member and a mount which is fixed relative to the body of the vehicle, wherein the spring is dimensioned such that at least one of the end portions thereof has a greater diameter than the mid-portion thereof.

Preferably bot end portions of the spring have a diameter greater than the mid-portion thereof.

The spring may be made of bar having a constant or a variable diameter and may have a constant or a variable pitch.

Tie spring may be mounted on a spring platform at each end thereof, the spring platforms being inclined relative to each other.

The use of a spring which has a smaller diameter at the mid-portion thereof makes it possible to position the damper closer to the spring than would otherwise be possible. It also makes it possible to position the spring closer to the line of action of the wheel centre line than would otherwise be possible.

For a better understanding of the present invention and to sow more clearly how it may be carried into effect reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 is a diagrammatic elevational view of one embodiment of a vehicle suspension assembly according to the present invention; and Figure 2 is a cross-section along the line II-II shown in Figure 1.

The vehicle suspension assembly shown in the figures comprises a vehicle body incorporating a vehicle subframe 1 on which a support member or wishbone 2 is pivotally mounted. A suspension spring 3 extends between the subframe and the wishbone and is mounted on spring platforms 4 and 5 respectively. A vibration compensating device in the form of a damper 6 also extends between the subframe and the wishbone and serves to damp out oscillations in the spring. A wheel 7 is mounted on the wishbone 2 and is rotated by a drive shaft 8.

The spring 3 is shaped so that is has a smaller diameter in the mid-portion thereof than at its ends, that is to say the shape of the spring 3 resembles an hour-glass. Figure 1 shows in chain-dotted lines the space required by a conventional spring. It can be seen that under the same conditions the hour-glass spring requires considerably less space and thus allows the damper 6 to be positioned closer to the spring 3 than would otherwise be possible.

Additionally, as can be seen from Figure 2, the hour-glass shape permits the spring 3 to be positioned closer to the drive shaft 8 which brings the spring load closer to the line of action of the wheel centre line.

The spring 3 may be made of bar having a constant diameter. However, it is advantageous to employ a bar having a variable diameter which introduces a progressive spring rate and reduces the weight of the spring.

Aaditionally, it is possible to vary the pitch of the spring. As an alternative to using an hour-glass shaped spring 3 it is possible to employ a spring which is shaped so that it has a smaller diameter in the mid-portion and at one end portion thereof.

The platforms 4 and 5 on which the spring is mounted may be inclined relative to each other so as to induce a predetermined bowing into the spring 3. This may permit the deflection of the spring 3 to be predicted with greater accuracy.

Where the wheel 7 is a steered wheel it is necessary to provide means for turning the wheel. In such a case the rod for turning the wheel may pass through the walls of the wishbone thereby saving further space.

Claims

1. A suspension assembly for a vehicle comprising a support member pivotally mounted relative to the body of the vehicle, a spring acting between the support member and a spring mount which is fixed relative to the body of the vehicle, and a vibration compensating device acting between the support member and a mount which is fixed relative to the body of the vehicle, wherein the spring is cimensioned such that at least one of the end portions thereof has a greater diameter than the mid-portion thereof.

2. A suspension assembly as claimed in claim 1, wherein both end portions of the spring have a diameter greater than the mid-portion thereof.

3. A suspension assembly as claimed in claim 1 or 2, wherein the spring is made of bar having a constant diameter.

4. A suspension assembly as claimed in claim 1 or 2, wherein the spring is made of bar having a variable diameter.

5. A suspension assembly as claimed in any one of claims 1 to 4, wherein the spring has a constant pitch.

6. A suspension assembly as claimed in any one of clains 1 to 4, wherein the spring has a variable pitch.

7. A suspension assembly as claimed in any preceding claim, wherein the spring is mounted on a spring platform at each end thereof, the spring platforms being inclined relative to each other.

8. A suspension assembly for a vehicle substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.