GB2197268A

GB2197268A - Transverse leaf spring suspension

Info

Publication number: GB2197268A
Application number: GB8723483A
Authority: GB
Inventors: David Cowburn
Original assignee: GKN Technology Ltd
Current assignee: GKN Technology Ltd
Priority date: 1986-10-07
Filing date: 1987-10-07
Publication date: 1988-05-18
Also published as: GB8624066D0; GB8723483D0

Abstract

A suspension for a motor vehicle, comprising a leaf spring portion (either end portions of a single spring 10 or individual springs 21) at each side of the vehicle, extending transversely thereof and having its outer end connected to a wheel carrier member 13, 24; and a U-shaped member with a body 18, 26 extending transversely of the vehicle to the front or rear of the spring portion and limbs 20, 27 extending rearwardly or forwardly to the wheel carriers. The U-shaped member acts as an anti-roll bar and assists wheel location. <IMAGE>

Description

SPECIFICATION SPECIFICATION Vehicle suspension This invention relates to an independent suspension for a pair of wheels of a motor vehicle.

The invention provides a suspension for a pair of wheels of a motor vehicle, comprising a leaf spring portion at each side of the vehicle, and extending transversely thereof, connected to the vehicle structure and having its outer end connected to a wheel carrier member; and a generally U-shaped member having a torsionally resilient body portion exteding transversely of the vehicle spaced forwardly or rearwardly of said spring portions and supported by the vehicle structure for pivotal movement about its longitudinal axis, and limbs at the ends of said body portion extending rearwardly or forwardly therefrom and connected to said wheel carrier members.

In a suspension according to the invention, the generally U-shaped member acts as an anti-roll bar in known manner, and assists control of the path of movement of the wheel carrier members, particularly in relation to resisting displacements forwardly or rearwardly of the vehicle under forces arising in use.

Preferably the wheel carrier members are further supported relative to the vehicle structure by respective generally vertically disposed damper units.

The leaf spring portions may be end portions of a single leaf spring extending transversely of the vehicle, or may be separate leaf spring portions.

The invention will now be described by way of example with reference to the accompanying drawings, of which: Figure 1 is a diagrammatic illustration of one embodiment of suspension according to the invention; Figure 2 is a diagrammatic view of a further embodiment of suspension according to the invention.

Referring firstly to Fig. 1, the suspension there illustrated comprises a leaf spring 10 extending transversely of the vehicle, having a central portion 11 secured to the vehicle at an appropriate member of the vehicle's chassis or integral body-chassis structure. The spring 10 is generally of semi-eliptical form-, and preferably is made of composite (fibre-reinforced plastics) material.

Each end of the leaf spring 10 is held within and secured to a respective end fitting 12 which in turn is connected, by a suitable swivel joint (not shown in detail), to a wheel carrier member 13. Each wheel carrier member supports, by a conventional stub axle, hub and bearing assembly, a wheel 14, and is further connected to the structure of the vehicle by respective generally vertically disposed telescopic damper strut 15 whose upper end 16 is mounted on the vehicle structure. A steering link forming part of the mechanism for steering the wheels is indicated diagrammatically at 17.

The suspension further comprises a generally U-shaped member having a body portion 18 which is torsionally resilient and is dis- posed forwardly or rearwardly (forwardly in the illustrated example) of the spring 19 and is pivotally supported by the vehicle structure by bushes 19. Limbs 20 at the ends of the body portion 18 extend rearwardly-from the body portion 18, and are connected, e.g. by suitable elastomeric bushes, to the spring end fittings 12 and thus to the wheel carrier members 13. When we say that limbs 20 extend rearwardly from the body portion 18, it will be appreciated that in practice, to suit a part'- ocular vehicle, they may be at an inclination to such body portion, rather than exactly perpendicular thereto.Similarly, when we refer to spring portions extending transversely of the vehicle they are not necessarily exactly perpendicular to the longitudinal centre line of the vehicle.

In use, the path of wheel travel relative to the vehicle structure is determined by the combination of spring 10, damper units 15, and U-shaped member 18, 20. The later member acts as an anti-roll bar to resist roll of the vehicle, and additionally assists in resisting forces on the wheels in the direction fore and aft of the vehicle. The suspension is not dependent on the lateral bending stiffness of the spring 10 (i.e. its stiffness in the direction normal to that in which it bends to provide vertical wheel springing) for resisting such forces acting fore and aft of the vehicle.

Referring now to Fig. 2 of the drawings, this shows a suspension generally similar to that of Fig. 1 but intended for the rear wheels of the vehicle and differing in that instead of a single spring 10 it utilises two individual leaf spring portions 21, extending transversely of the vehicle. Each leaf spring portion is supported at its innermost end relative. to the vehicle structure, not shown, to extend outwardly as a cantilever from a support 22 and reaction abutment 23. The outermost end of each spring portion is connected to a respective wheel carrier member 24, by a pivotal connection providing for pivotal movement about a respective axis extending transversely of the spring portion, i.e. fore and aft of the vehicle.

Because it is intended for the rear wheels of the vehicle, wheel carrier members 24 do not provide for steering swivelling movement.

They are further supported relative to the vehicle structure by telescopic damper units 25, and as for the embodiment of Fig. 1 there is a generally U-shaped member with a tor sioriálly resilient body portion 26 and end limbs one of which is visible at 27, extending forwardly or rearwardly to connect to the wheel carrier members 24.

Spring portions 21 are of composite, fibrereinforced plastics material, and as illustrated they are of tapered configuration, of decreasing thickness towards their outermost ends.

Any appropriate configuration of such leaf spring portions could, however, be used. As in the embodiment of Fig. 1, the U-shaped member 26, 27 at least partially relieves the spring portions of having to withstand loads in directions fore and aft of the vehicle, and the configuration of the spring portions would be designed with this in view.

Claims

1. A suspension for a pair of wheels of a vehicle, comprising a leaf spring portion at each side of the vehicle and extending transversely thereof, connected to the vehicle structure and having its outer end connected to a wheel carrier member; and a generally Ushaped member having a torsionally resilient body portion extending transversely of the vehicle spaced forwardly or rearwardly of said spring portions and supported by the vehicle structure for pivotal movement about its longitudinal axis, and limbs at the ends of said body portion extending rearwardly or forwardly therefrom and connected to said wheel carrier members.

2. A suspension according to Claim 1 wherein said wheel carrier members are further supported relative to the vehicle structure by generally vertically disposed telescopic damper units.

3. A suspension according to Claim 1 or Claim 2 wherein said leaf spring portions are end portions of a single leaf spring.

4. A suspension according to Claim 1 or Claim 2 wherein said leaf spring portions are separate leaf springs.

5. A suspension according to any of the preceding claims wherein said leaf spring portions are of composite (fibre-reinforced plastics) material.

6. A suspension substantially as hereinbefore described with reference to Fig. 1 or Fig.

2 of the accompanying drawings.