GB2310838A

GB2310838A - Vehicle axle assembly

Info

Publication number: GB2310838A
Application number: GB9703271A
Authority: GB
Inventors: Philip Kohn; Peter Holdmann; Dieter Braun
Original assignee: Daimler Benz AG
Current assignee: Daimler Benz AG
Priority date: 1996-03-06
Filing date: 1997-02-17
Publication date: 1997-09-10
Anticipated expiration: 2017-02-17
Also published as: FR2745757B1; ITRM970117A1; IT1290955B1; DE19608578A1; FR2745757A1; GB9703271D0; GB2310838B

Description

1 Vehicle axle assembly 2310838 The invention relates to a vehicle axle

assembly with independent wheel suspension and spring assemblies, assigned separately to the wheels, without wheel-guidance functions, and with body-side spring assembly abutments which are positively coupled to one another to give adjustment in the same direction.

Axle assemblies of this kind are generally known. In this arrangement, the wheels of such an axle assembly can, for example, be guided by a twin arrangement of transverse links, i.e. transverse links arranged vertically one above the other.

One such arrangement forms the subject-matter of German Auslegeschrift 1, 254,480. The axle assembly described there has a wheel-pressure compensating means. For this purpose, the body-side spring mounts are positively coupled to one another to give movements in the same direction. This has the ef f ect that, in the event of an upward movement of one wheel of the axle assembly relative to the vehicle body, that wheel of the axle assembly which is arranged on the opposite side of the body tends to execute a downward movement relative to the vehicle body.

According to German Auslegeschrift 1,254,480, the spring assemblies operate with torsion bars, one end of which is held in a manner fixed against rotation on the respective upper transverse link of the associated wheel and the other end of which is in each case held in a manner fixed against rotation in an abutment which is mounted on the respective upper transverse link in such a way as to be rotatable about an axis parallel to the body-side pivoting axis of the upper transverse link and is positively coupled by mechanical means to the corresponding spring abutment of the other wheel, such that the spring abutments can execute rotary movements in the same direction.

It is furthermore a fundamentally known practice to design running-gear assemblies of vehicles in such a.way that 2 tilting of the vehicle body towards the inside of the bend is made possible during cornering.

The present invention seeks to provide an expedient axle assembly for this purpose.

According to the present invention there is provided a vehicle axle assembly with independent wheel suspension and spring assemblies operatively extending between the body and the wheels, assigned separately to the wheels, and with bodyside spring assembly abutments which are positively coupled to one another to give adjustment in the same direction, wherein spring struts or spri ng-and- shock absorber struts are in each case provided as spring assemblies and their body-side abutments are arranged essentially fixed in relation to the body in the direction of a vertical axis of the body and, in the direction of a transverse axis of the body, are adjustable simultaneously and in the same direction by means of an actuator in order to enable a tilt of the body directed towards the inside of the curve during cornering.

Preferably, the wheels are guided by a twin arrangement of transverse links. The body-side abutments of the spring struts are preferably each arranged on levers which are pivotable about a longitudinal axis of the vehicle and are positively coupled to one another to give pivoting in the same direction. The positive coupling may be mechanical or hydraulic. Preferably, the levers are positively coupled to one another by means of a rod in such a way as to be simultaneously pivotable.

In an alternative embodiment, the levers are positively coupled to one another by means of a multiple-link arrangement in such a way as to be simultaneously pivotable. The wheels may each be guided by a multiplelink assembly, in particular a 5-link assembly.

The invention is based on the general idea of enabling adjustment of the body-side abutments of the spring struts with comparatively small forces by virtue of the fact that the static normal wheel forces acting in the direction of the vertical axis of the body lead essentially only to 3 internal forces in body-side parts or in the positive coupling between the body-side abutments of the axle assembly and can therefore not appear as resistances during the adjustment of these abutments. As the end result of this, both the body and the wheels of the axle assembly can be tilted in a desired direction with a comparatively small actuating force.

As regards preferred features of the invention, attention is drawn to the following description of advantageous embodiments, which are explained with reference to the drawings, in which:

Fig. 1 shows a view in the longitudinal direction of the vehicle of a slightly schematized overall representation of an axle assembly according to the invention in the normal position of the wheels, Fig. 2 shows a half axle of an axle assembly in a constructional representation, the wheel again being in its normal position, and Fig. 3 shows a representation corresponding to that in Fig. 2, the wheel and the body assuming a laterally inclined position.

Fig. 1 shows an axle frame 1 which is connected to a vehicle body (not shown) in an essentially rigid manner or via damping elements which allow only a small degree of relative mobility between the axle frame 1 and the body, or which can form part of a floor assembly of a vehicle body or chassis. Wheels 2 are arranged on both sides of the axle frame by means of upper and lower transverse links 3 and 4. The upper transverse link 3 has an upper, axle-frame-side coupling point 5 and an upper, wheel-side coupling point 6 on a wheel carrier 7, while the lower transverse link 4 has a lower coupling point 8 on the axle frame 1 and a lower coupling point 9 on the wheel carrier 7. Thus, overall, the transverse links 3 and 4 form a parallelogram-type arrangement with the coupling points 5, 6, 8 and 9.

Each wheel 2 is assigned a spring strut 10, which is designed as a springand-shock absorber strut and, in a fundamentally known form, comprises a shock absorber and a 4 helical compression spring.

Each spring strut 10 has a wheel-side coupling point, which, in the example of Fig. 1, coincides with the wheel-side coupling point 9 of the respective lower transverse link 4.

The body-side abutment of each spring strut 10 is in each case arranged on a lever 11 which is mounted on the axle f rame 1 in such a way as to be pivotable about a longitudinal axis of the vehicle, this mounting in each case coinciding, in the example of Fig. 1, with the body-side coupling point 8 of the lower transverse link 4.

The two levers 11 are positively coupled to one another by a rod 12 in such a way as to give simultaneous pivoting.

An actuator 14 is arranged between one of the levers 11 and an abutment 13 which is fixed to the axle frame, allowing the levers 11 to be pivotally moved simultaneously and in the same direction relative to the axle frame 1.

During such a pivoting movement, one of the wheels 2 is urged in the downward direction and the other wheel 2 in the upward direction relative to the axle f rame 1. During this pivoting movement, the actuator 14 has to transmit only relatively small forces because the static normal forces of the wheels absorbed by the spring struts 10 cannot act on the actuator 14 but can lead only to internal forces in the axle frame 1, the levers 11 and the rod 12.

The embodiment of Fig. 2 differs from the embodiment of Fig. 1 first of all in having a track rod, denoted by 15, of a steering system by means of which the wheels 2 are steered.

The wheel-side abutment of each spring strut 10 between the wheel 2 and the axle frame 1 is furthermore arranged on the lower transverse link 4. However, this does not make any functional difference in relation to the embodiment of Fig. 1.

Fig. 3 illustrates the conditions during the pivoting of the levers 11 relative to the axle frame 1. Both the wheels 2 and the axle f rame 1 and, accordingly, also the vehicle body (not shown) are then tilted to the side.

As a departure from the embodiments illustrated, the rod 12 can also be replaced by hydraulic positive coupling of the levers 11. For this purpose, each lever 11 can be coupled in drive terms to a hydraulic cylinder which is hydraulically positively connected to the hydraulic cylinder of the other lever in each case.

As a departure from the embodiment illustrated, the levers 11 can also be positively coupled to one another by a multiple-link arrangement.

Moreover, the wheels 2 can also be guided in a manner different from that shown in the drawing. Instead of wheel guidance by means of a twin arrangement of transverse links, a multiple-link assembly, e.g. a 5-link assembly, can also be provided.

6

Claims

1. A vehicle axle assembly with independent wheel suspension and spring assemblies operatively extending between the body and the wheels, assigned separately to the wheels, and with body-side spring assembly abutments which are positively coupled to one another to give adjustment in the same direction, wherein spring struts or spring-and-shock absorber struts are in each case provided as spring assemblies and their body-side abutments are arranged essentially fixed in relation to the body in the direction of a vertical axis of the body and, in the direction of a transverse axis of the body, are adjustable simultaneously and in the same direction by means of an actuator in order to enable a tilt of the body directed towards the inside of the curve during cornering.

2. An axle assembly according to Claim 1, wherein the wheels are guided by a twin arrangement of transverse links.

3. An axle assembly according to Claim 1 or 2, wherein the body-side abutments of the spring struts are each arranged on levers which are pivotable about a longitudinal axis of the vehicle and are positively coupled to one another to give pivoting in the same direction.

4. An axle assembly according to any one of Claims 1 to 3. wherein there is mechanical positive coupling.

5. An axle assembly according to any one of Claims 1 to 3f wherein hydraulic positive coupling is provided.

6. An axle assembly according to Claim 3, wherein the levers are positively coupled to one another by means of a rod in such a way as to be simultaneously pivotable.

7. An axle assembly according to Claim 3, wherein the levers are positively coupled to one another by means of a 7 multiple-link arrangement simultaneously pivotable.

in such a way as to be

8. An axle assembly according to any one of Claims 1 to 7, wherein the wheels are each guided by a multiple-link assembly.

9. An axle assembly according to Claim 8, wherein the wheels are each guided by a 5-link assembly.

10. A vehicle axle assembly with independent wheel suspension and spring assemblies operatively extending between the body and the wheels, substantially as described herein with reference to, and as illustrated in, the accompanying drawings.