GB1571565A

GB1571565A - Suspension for commercial vehicles

Info

Publication number: GB1571565A
Application number: GB2183877A
Authority: GB
Original assignee: Daimler Benz AG
Current assignee: Daimler Benz AG
Priority date: 1976-06-01
Filing date: 1977-05-24
Publication date: 1980-07-16
Also published as: FR2353409A1; IT1078135B; FR2353409B1; DE2624430B1; DE2624430C2; SE7706342L

Description

(54) SUSPENSION FOR COMMERCIAL VEHICLES (71) We, DAIMLER-BENZ AKTIENGESELLSCHAFT, of Stuttgart Unterttirkheim, Germany, a Company organised under the laws of the Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:: The invention relates to an axle suspension for vehicles, particularly a front-axle suspension for all-wheel drive motor vehicles, of the kind, hereinafter referred to as the kind set forth, in which an axle assembly, abutted resiliently in relation to the vehicle frame or body, has associated with it a torsion-bar stabiliser bent to U-shape in plan view, whose bar portion extending transversely of the vehicle is supported in relation to the frame or body at two bearing points, while its arms are articulated to the said axle assembly.

Known axle suspensions of the kind set forth have certain drawbacks, particularly in the case of commercial vehicles or crosscountry utility vehicles with large spring deflections, as with all-wheel driven vehicles, which can lead to excessive stressing of the stabiliser. In suspensions in which the stabiliser serves also for longitudinal guidance of the axle assembly, excessive twisting of the stabiliser may occur.

The present invention seeks to provide an axle suspension of the kind set forth, particularly for all-wheel drive vehicles including agricultural and other cross-country vehicles, by which excessive stressing of the stabiliser is avoided even with large spring deflections.

According to the invention, a vehicle-axle suspension comprises, in combination with a rigid-axle assembly abutted resiliently in relation to the vehicle frame, a torsion-bar stabiliser, bent to a U-shape in plan view, whose bar portion, extending transversely of the vehicle, is supported in relation to the frame at two bearing points and each of whose arms, extending in the longitudinal direction of the vehicle, is articulated to the axle assembly which is guided in relation to the frame independently of the stabiliser, each said arm having a flat, upright, cross section over part of its length and being slidably guided in its longitudinal direction by an end part of round cross section slidable in a guide bore in the ball of a universal ball joint whose ball socket is so held on the axle assembly as to be immovable in relation thereto in the direction axially of the said end part.

The universal mobility of the joint and the resilience of the stabiliser arms in the transverse direction of the vehicle afforded by the aforesaid upright flat cross section have the effect that, even in event of large spring deflection on one side of the vehicle, no considerable stresses can arise between the stabiliser and axle assembly in the transverse direction of the vehicle which could result in undesirable stiffening in the spring behaviour and excessive stressing of the stabiliser.

The upright flat cross-section of the arms permits necessary lateral resilience of the arms by which superimposed bending and torsional stresses in the transitions from the arms to the bar of the stabiliser can largely be avoided. At the same time the longitudinally slidable articulations of the arms to the assembly also permit longitudinal movements between the stabiliser and the assembly, whose suppression would unfavourably influence the conditions of loading of the stabiliser. Unfavourable loading conditions, in conjuction with the torsional stresses which occur, could lead to fracture of the stabiliser.

Each ball socket may be disposed in a bearing support which is mounted on the said assembly by respective transversely disposed hoops for securing a set of longitudinal leaf springs to the assembly. The bearing support may be an angular element, in one arm of which a horizontal bore accommodating the ball socket is provided and of which the other arm is clamped, in relation to the said assembly, against the underside of a seating for the set of springs by means of the hoops.

One embodiment of the invention will now be more fully described with reference to the accompanying drawings, in which: Figure I is a plan view of a steerable, driven, axle guided by means of a longitudinal leaf springs and suitable in particular, for a front axle of a commercial or utility vehicle.

Figure 2 a rear view of the same axle, Figure 3 is diagrammatic plan view, partly in section, to a larger scale, showing the articulation of one arm of a torsion bar to an axle-housing assembly, and Figure 4 is a side view of the articulation arrangement shown in Figure 3.

Referring to the drawings, a housing assembly 1 of a vehicle rigid axle abutted by sets of leaf springs 2 in relation to the vehicle frame or body (not shown) is associated with axle gearing 3. Driving connections to steerable wheels 4 are through joints (not shown) provided in the region of wheel carriers 5 which are pivotably mounted on the assembly 1. Each carrier 5 is connected by a track arm 6 to a track rod 7 and one of them is connected to a steering arm 8 on which steering gear (not shown) operates.

The sets of leaf springs 2 are clamped by spring hoops 9 in the form of U-bolts against respective spring-seating plates 10. As may be seen from Figures 3 and 4, there is secured to each plate 10, by the ends, projecting below the plate, of the limbs of respective hoops 9, a bearing support 12, in which a corresponding end portion 13 of one arm 14 of a torsion-bar stabiliser 15 bent to a U-shape in plan view (Figure 1) is held. The arms 14 are connected together by the actual torsion bar 16 which extends transversely of the direction of travel 11 and is mounted on the vehicle frame or body (not shown) by way of bearings indicated diagrammatically at 17 (Figure 1).

Over its length between the end portions 13 and the torsion bar 16, each arm 14 of the stabiliser 15 is forged to an upright flat cross-section which, at one end, merges into the circular cross-section of the bar 16 and at the other end (Figures 3 and 4) terminates in the end portion 13, which is also of circular cross-section.

As shown in Figure 4, the bearing support 12 is an angular element of which one arm 12a is clamped against the spring-seating plate 10 by screw means on the limbs of the hoops 9. The other arm 12b, which extends substantially vertically, has a substantially horizontal bore 18 accommodating a balljoint socket 19 which is located axially in the said bore by, in the present example, spring rings 20. The socket 19 receives a joint ball 21 provided with an axial guide bore 22 in which the end portion 13, of circular crosssection, of the respective arm 14 of the stabiliser 15 is held in longitudinally slidable manner. Relative sliding movement is limited at the end towards the torsion bar 16 by a collar 23 and at the other, free, end of the arm by a nut 24 screwed thereon.The cylindrical end portion 13 between these stop parts 23, 24 and the joint socket 19 is covered by elastic bellows 25 which, as shown in Figures 3 and 4, are provided at the ends near the bearing support 12 with collars engaged in respective circumferential grooves 26 in the bore 18.

With the above described arrangement, on the one hand the articulations of the torsion-bar stabiliser 15 at the axle end can be secured in a simple manner and on the other hand, because of the nature of the articulated, longitudinally sliding, guidance of the end portion 13 and because of the flat, upright, cross-section of the arms 14, the latter can adapt themselves to such a large extent to the movements, in relation to the body, of the axle-housing assembly, which movements may be very considerable in the case of cross-country vehicles, that unallowable stressing of the stabiliser can be avoided. Both the stabiliser and its articulations can, therefore, be given more advantageous dimensions.

WHAT WE CLAIM IS: 1. A vehicle-axle suspension comprising, in combination with a rigid-axle assembly abutted resliently in relation to the vehicle frame, a torsion-bar stabiliser, bent to a U-shape in plan view, whose bar portion, extending transversely of the vehicle, is supported in relation to the frame at two bearing points and each of whose arms, extending in the longitudinal direction of the vehicle, is articulated to the axle assembly which is guided in relation to the frame independently of the stabiliser, each said arm having a flat, upright, cross section over part of its length and being slidably guided in its longitudinal direction by an end part of round cross section slidable in a guide bore in the ball of a universal ball joint whose ball socket is so held on the axle assembly as to be immovable in relation thereto in the direction axially of the said end part.

2. A suspension according to claim 1, wherein each said ball socket is disposed in a bearing support which is mounted on the said assembly by respective transversely disposed hoops for securing a set of longitu

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. said assembly by respective transversely disposed hoops for securing a set of longitudinal leaf springs to the assembly. The bearing support may be an angular element, in one arm of which a horizontal bore accommodating the ball socket is provided and of which the other arm is clamped, in relation to the said assembly, against the underside of a seating for the set of springs by means of the hoops. One embodiment of the invention will now be more fully described with reference to the accompanying drawings, in which: Figure I is a plan view of a steerable, driven, axle guided by means of a longitudinal leaf springs and suitable in particular, for a front axle of a commercial or utility vehicle. Figure 2 a rear view of the same axle, Figure 3 is diagrammatic plan view, partly in section, to a larger scale, showing the articulation of one arm of a torsion bar to an axle-housing assembly, and Figure 4 is a side view of the articulation arrangement shown in Figure 3. Referring to the drawings, a housing assembly 1 of a vehicle rigid axle abutted by sets of leaf springs 2 in relation to the vehicle frame or body (not shown) is associated with axle gearing 3. Driving connections to steerable wheels 4 are through joints (not shown) provided in the region of wheel carriers 5 which are pivotably mounted on the assembly 1. Each carrier 5 is connected by a track arm 6 to a track rod 7 and one of them is connected to a steering arm 8 on which steering gear (not shown) operates. The sets of leaf springs 2 are clamped by spring hoops 9 in the form of U-bolts against respective spring-seating plates 10. As may be seen from Figures 3 and 4, there is secured to each plate 10, by the ends, projecting below the plate, of the limbs of respective hoops 9, a bearing support 12, in which a corresponding end portion 13 of one arm 14 of a torsion-bar stabiliser 15 bent to a U-shape in plan view (Figure 1) is held. The arms 14 are connected together by the actual torsion bar 16 which extends transversely of the direction of travel 11 and is mounted on the vehicle frame or body (not shown) by way of bearings indicated diagrammatically at 17 (Figure 1). Over its length between the end portions 13 and the torsion bar 16, each arm 14 of the stabiliser 15 is forged to an upright flat cross-section which, at one end, merges into the circular cross-section of the bar 16 and at the other end (Figures 3 and 4) terminates in the end portion 13, which is also of circular cross-section. As shown in Figure 4, the bearing support 12 is an angular element of which one arm 12a is clamped against the spring-seating plate 10 by screw means on the limbs of the hoops 9. The other arm 12b, which extends substantially vertically, has a substantially horizontal bore 18 accommodating a balljoint socket 19 which is located axially in the said bore by, in the present example, spring rings 20. The socket 19 receives a joint ball 21 provided with an axial guide bore 22 in which the end portion 13, of circular crosssection, of the respective arm 14 of the stabiliser 15 is held in longitudinally slidable manner. Relative sliding movement is limited at the end towards the torsion bar 16 by a collar 23 and at the other, free, end of the arm by a nut 24 screwed thereon.The cylindrical end portion 13 between these stop parts 23, 24 and the joint socket 19 is covered by elastic bellows 25 which, as shown in Figures 3 and 4, are provided at the ends near the bearing support 12 with collars engaged in respective circumferential grooves 26 in the bore 18. With the above described arrangement, on the one hand the articulations of the torsion-bar stabiliser 15 at the axle end can be secured in a simple manner and on the other hand, because of the nature of the articulated, longitudinally sliding, guidance of the end portion 13 and because of the flat, upright, cross-section of the arms 14, the latter can adapt themselves to such a large extent to the movements, in relation to the body, of the axle-housing assembly, which movements may be very considerable in the case of cross-country vehicles, that unallowable stressing of the stabiliser can be avoided. Both the stabiliser and its articulations can, therefore, be given more advantageous dimensions. WHAT WE CLAIM IS:

1. A vehicle-axle suspension comprising, in combination with a rigid-axle assembly abutted resliently in relation to the vehicle frame, a torsion-bar stabiliser, bent to a U-shape in plan view, whose bar portion, extending transversely of the vehicle, is supported in relation to the frame at two bearing points and each of whose arms, extending in the longitudinal direction of the vehicle, is articulated to the axle assembly which is guided in relation to the frame independently of the stabiliser, each said arm having a flat, upright, cross section over part of its length and being slidably guided in its longitudinal direction by an end part of round cross section slidable in a guide bore in the ball of a universal ball joint whose ball socket is so held on the axle assembly as to be immovable in relation thereto in the direction axially of the said end part.

dinal leaf springs to the assembly.

3. A suspension according to claim 2, wherein the bearing support is an angular element, in one arm of which a horizontal bore accommodating the ball socket is provided and of which the other arm is clamped, in relation to the said assembly, against the underside of a seating for the set of springs by means of the hoops.

4. An axle suspension substantially as hereinbefore described with reference to the accompanying drawings.