Suspension system for motor vehicles
A suspension system for motor vehicles with a level control for adjusting a predetermined height of the vehicle body is configured with at least one piston-cylinder unit which is provided with a work cylinder, a piston rod and a damping piston having damping valves, a pump of an oil reservoir, corresponding inlet lines and outlet lines from the oil reservoir, and corresponding inlet lines and outlet lines from the oil reservoir to the piston-cylinder unit, and vice versa, and the pump is configured with a pump piston and a drive unit. The piston-cylinder unit and the pump are constructed as separate subassemblies which are manufactured independently beforehand, and at least the piston-cylinder unit is filled with damping medium before the two subassemblies are mounted.
1. A suspension system for a motor vehicle with level regulation for adjusting a height of a vehicle body, comprising:
a piston-cylinder unit provided with a work cylinder, a piston rod axially movable in the work cylinder, and a damping piston connected to the piston rod;
an arrangement of damping valves provided in the damping piston and operable during rebound and compression strokes of the damping piston;
a high pressure chamber and a low pressure chamber which are partially filled with damping medium;
a pump unit for pumping damping medium from the low pressure chamber to the high pressure chamber, the pump unit comprising a pump piston and a drive unit for reciprocally displacing the pump piston, the piston-cylinder unit being assembled separately from the pump unit and configured to receive damping medium prior to mounting the pump unit to the piston-cylinder unit; and
a base on the piston-cylinder unit configured to support the pump unit and having at least one connection for conducting a flow of damping medium to or from the pump unit when the pump unit is mounted on the piston-cylinder unit, the at least one connection being open to the atmosphere when the pump unit is not mounted on the piston-cylinder unit, the base comprising blocking elements which prevent flow communication between the chambers and the at least one connection prior to mounting the pump unit on the piston-cylinder unit.
2. The suspension system of claim 1 , wherein the blocking elements comprise at least one closure member and at least one check valve.
3. The suspension system of claim 1 , wherein the pump unit comprises a housing having a plurality of check valves.
4. The suspension system of claim 1 , wherein the piston-cylinder unit and the pump unit can be tested independently from one another.
5. The suspension system of claim 1 , wherein the pump unit and the base are configured so as to selectively couple to one another in a plurality of coupling positions.
6. The suspension system of claim 1 , wherein the piston-cylinder unit further comprises an outer tube spaced radially outwards from the work cylinder and comprising the base.
7. The suspension system of claim 1 , wherein the at least one piston-cylinder unit further comprises:
an outer tube spaced radially outwards from the work cylinder;
an intermediate wall extending between the outer tube and the work cylinder and separating the high pressure chamber from the low pressure chamber;
a flow connection connecting the low pressure chamber to the pump unit.
8. The suspension system of claim 7 , further comprising a flow connection through the intermediate wall connecting the pump unit to the high pressure chamber when the pump unit is mounted on the piston-cylinder unit.