FR2564042A1 - Suspension device with telescopic leg for a vehicle wheel - Google Patents

Abstract

In the invention the spring 14 surrounding the telescopic suspension leg 3 has an approximately frustoconical general shape, its broad base resting on the lower collar 15 which is off-centred towards the exterior of the vehicle with respect to the axis Xj of the leg 3, while its other base rests on the upper collar 16 which is approximately concentric with the said axis. This results in a telescopic leg suspension device which both occupies little transverse room and has a low resistance to sliding. Application particularly to the steered wheels of vehicles.

Description

The invention relates to suspension devices

  sion of a vehicle wheel, of the type comprising a telescopic leg comprising a lower sliding element laterally carrying the wheel and connected to the vehicle structure by a lower arm extending approximately transversely, and an upper sliding element connected to the

  structure of the vehicle by an articulation, a spring

  turning the leg being compressed between an upper cup

  lower and a lower cup respectively solidai-

  res of the joint and the lower sliding element.

  The sliding axis of the usual cutting leg-

  the ground at a point in the interior of the vehicle

  moves with respect to the center of the contact zone between the wheel and the ground, so that the reaction force of the ground on the wheel does not generate excessive friction in line with the sliding parts of the leg, the axis of the spring is of

  preferably inclined relative to the axis of the leg, its push

  sée between the cups being carried out on average according to

  a straight line roughly passing through the center of the

  lation and by a point on the ground located outside the

  vehicle with respect to the center of said contact area.

  In order not to occupy too much space in

  the vehicle in a transverse direction, the leg is

  carefully placed very close to the wheel and slightly inclined with respect to the vertical. The inclination of the spring must

  be important for resistance to sliding-

  leg is minimal. The spring being usual-

  helical, its winding diameter must then be wide enough so that it does not strike the leg internally, and the upper cup must be offset towards

  the interior of the vehicle.

  bothersome of the spring in this area, especially when it is a steerable wheel because in this case the spring and the cups pivot, at the same time as the wheel, around an approximately vertical axis. revenge the spring

  is less inclined to be less bulky, the slide

  the leg is carried out with more friction, which affects the qualities of the suspension and the steering

of the vehicle.

  The invention aims to achieve, to connect

  a wheel which can be steered to the structure of a vehicle

  hicule, a telescopic leg suspension device having both a small transverse space requirement and

  low sliding resistance.

  According to the invention, the device of the aforementioned type, is characterized in that the spring is of general shape

  approximately frustoconical, its base resting on the neck

  lower shovel which is offset towards the outside of the vehicle

  hicle with respect to the axis of the leg, while its other base rests on the upper cup which is little

near concentric with said axis.

  According to another advantageous characteristic of the invention, the spring is located higher than the wheel and the lower cup has, between its edge located towards

  the outside of the vehicle and its central part, a recess

  lying upward, bypassing the upper periphery of

  the wheel and thus allowing the spring to be lowered as much as possible

comes out above the wheel.

  An exemplary embodiment of a suspension device

  telescopic leg board according to the invention is described

  below, with reference to the accompanying drawing, of which the sole Fi-

  gure is a partial sectional view along a sensitive plane-

  transverse to the vehicle and passing through the axis of the leg.

  We can see on the Figure a wheel 1 laterally

  also by a sliding element 2 of a hanger leg

  sion 3 connected to the structure 4 of a vehicle by a rear

  upper ticulation 5 and by a lower arm 6 sensi-

  transversely. The upper leg element which slides in element 2 by means of a rod 7 which slides in element 2 by means of a

  piston 8 and a guide ring 9 respectively so-

  lidaries of the lower end of the rod 7 and

  the upper end of element 2.

  The articulation 5 comprises an annular block 10 of elastomer integral internally with a hub 11

  attached to the upper end of the rod 7, and external-

  ment of a socket 12 fixed to the structure 4. A sealing bellows 13 surrounds the rod 7 between the hub '11 and

ring 9.

  The wheel 1 is steerable, that is to say that the element 2 which carries it can pivot, by means of a wheelhouse not shown, around the axis joining the center of the articulation 5 to the center of a ball joint 6a which connects the arm 6 to the element 2. This pivot axis is here merged with the axis Xj of the leg 3, therefore of the rod 7, around which the element 2 and the wheel 1 pivot. A spring 14 arranged around the leg and

  located higher than the wheel is compressed between a

  lower shovel 15 integral with element 2 and a cou-

  upper shovel 16 bearing on the hub 11, with inter-

  position of a thrust bearing 17 allowing this cup, as well as the spring 14, to pivot at the same time

  that element 2 around rod 7.

  According to the invention, this spring is of general shape.

  truncated conical, its broad base resting on the cup-

  the lower 15.This is offset to the outside

  of the vehicle relative to the leg, and it includes,

  its edge 18 located towards the outside of the vehicle and its hub 19 connecting it to the element 2, a recess 20 turned upward: so as to bypass the upper periphery of the rDue. This recess makes it possible to lower

  the more the cup 15 as it is wider.

  The upper cup 16 cooperating with the

  small base of the frustoconical spring, is roughly con-

  centric at ti j 7 and its outside diameter is

  same order of magnitude as that of socket 12.

  The eccentricity of the cup 15 is such that the axis Xr of the spring 14 is notably inclined relative to that Xj of the rod 7; these axes Xr and Xj meet the ground respectively outward and inward of the vehicle with respect to the center C of the contact zone of the wheel on the ground. The average thrust of the spring 14 on the cups is thus oriented, in a known manner, so as to

  prevent the vertical reaction of the ground on the wheel from causing

  dre, in line with the piston 8 and the ring 9, transient forces

  where there are harmful rubbing rubs

  smoothing of the leg and pivoting of the wheel.

  The optimal position of the axis Xr of the spring is such that it cuts approximately vertically from point C to

  extension of the straight line connecting the centers of the articulations

arm 6.

  Thanks to the relatively small size of the cou-

  upper shovel 16 and at the eccentricity of the cup

  lower 15, the part of the spring located on the interior side of the vehicle can be over its entire height disposed very close to the leg 3, and the upper part of this can be closer to the neighboring body 21 than when the spring is helical .Spring 14 thus mainly uses the free volume located above the wheel, while it takes up less useful space, on the inside, than an equivalent helical spring which would be inclined according to

  the same axis of average thrust Xr, especially when pivoting-

  the wheel if it is steerable, or for a

  space given in transverse direction, the spring cuts

  conical can be more inclined than an equivalent coil spring, and therefore further reduce friction

sliding leg.

  In addition, the spring having large turns on the side of its lower base, its flexibility is greater than

  that of a conventional coil spring of the same height.

  Consequently, for the same flexibility, the frustoconical spring

is less bulky in height.

  Alternatively, the shape of the spring 14 may not be

  only approximately frustoconical, while keeping essential-

  Lely a wide lower base eccentric to the outside

  of the vehicle and a small base, roughly about one hundred

  on the rod, for example the general shape of the spring

  can be rounded like a barrel.

  The spring is advantageously made of a wire whose section increases from the small base to the wide base of the spring, so that the mechanical stresses in this wire are almost uniformly distributed.

2564042.

Claims (2)

- CLAIMS -   1 - Suspension device for a vehicle wheel   cule comprising a telescopic leg comprising an element   lower sliding element (2) carrying the wheel laterally   (1) and connected to the vehicle structure by a lower arm   laughing (6) extending approximately transversely, and an ele-   sliding upper part (7) connected to the structure of the vehicle   flows by an articulation (5), a spring (14) surrounding the leg being compressed between an upper cup (16) and a lower cup (15) respectively secured   of the joint and the lower sliding element, ca-   characterized in that the spring (14) is of general shape.   approximately frustoconical, its broad base resting on   the lower cup (15) which is eccentrically outward   laughter of the vehicle with respect to the axis (Xj) of the leg   (3), while its other base rests on the upper cup   higher (16) which is roughly concentric with said axis.   2 - Device according to claim 1, character-   risé in that the spring (14) is located higher than the wheel (1) and the lower cup (15), comprises between its   edge located towards the outside of the vehicle and its central part   trale, a recess (20) extending upwards, contour-   nant the upper periphery of the wheel (1) and thus allowing to lower the spring above the wheel.