Suspension system for motor vehicles

Abstract

A piston-cylinder unit includes a working cylinder, a damping piston mounted for movement in the cylinder, and a piston rod connected to the piston. An outer tube surrounding the working cylinder defines a compensating space, and a piston rod guide fitted to the working cylinder and the outer tube closes off an end of the compensating space, the piston rod guide having a bore communicating with the compensating space. An envelope body of variable shape, located in the compensating space, is filled with gas through a connecting element having a cylindrical portion fitted in the bore. The connecting element also has a lobe which is received through an elongate aperture in a retaining plate fitted over the bore when the connecting element is in a selected orientation, the lobe being axially retained under the plate by rotating the connecting element from the selected orientation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a partial cross section of a suspension system for motor vehicles;

FIG. 2 shows an enlarged view of a cross section of an envelope body with its connecting element in isolation; and

FIGS. 3-11 show cross sections, front views, and perspective views of details of the connecting element.

Claims

1. A suspension system for motor vehicles, comprising: a piston-cylinder unit comprising a working cylinder, a damping piston mounted for movement in said cylinder, and a piston rod connected to the piston;an outer tube surrounding said working cylinder and defining a compensating space between said outer tube and said working cylinder;a piston rod guide fitted to said working cylinder and said tube to close off an end of said compensating space, said piston rod passing through said piston rod guide, said piston rod guide having a bore communicating with said compensating space;an envelope body of variable shape in said compensating space, said envelope body comprising a gas-tight barrier layer;a retaining plate fitted over said bore in said piston rod guide, said retaining plate having an elongate aperture; anda connecting element having a cylindrical portion fitted in said bore and a lobe which is received through said elongate aperture in a selected orientation, said lobe being axially retained under said plate by rotating said connecting element from said selected orientation.

2. The suspension system of claim 1 wherein said connecting element is a molded part, said cylindrical portion having a surface which is free of mold-removal burrs.

3. The suspension system of claim 1 wherein said piston rod guide has a recess surrounding said bore, said retaining plate being fitted in said recess.

4. The suspension system of claim 3 wherein said piston rod guide is made of a material which can be deformed, said retaining plate being retained in said recess by deforming said material to overlap said retaining plate.

5. The suspension system of claim 4 wherein the recess has an external contour which is at least partially circular.

6. The suspension system of claim 5 wherein the retaining plate has an external contour which is at least partially circular.

7. The suspension system of claim 5 wherein said retaining plate comprises means for preventing rotation of said retaining plate in said recess.

8. The suspension system of claim 7 wherein said means for preventing rotation comprises a notch in the external contour of the retaining plate, said material of said piston rod guide being deformed to flow into said notch.

9. The suspension system of claim 1 further comprising a sealing ring fitted radially between said cylindrical sealing portion and said piston rod guide.

10. The suspension system of claim 9 further comprising a support ring fitted around the cylindrical sealing portion between the sealing ring and the lobe.

11. The suspension system of claim 10 wherein the support ring is free to move axially with respect to the connecting element.

12. The suspension system of claim 1 wherein the lobe is axially retained under the plate by rotating the connecting element through approximately ninety degrees from said selected orientation.

13. The suspension system of claim 1 wherein said connecting element has two lobes, said lobes being retained under said plate on opposite sides of said elongate aperture when said connecting element is rotated from said selected orientation.