Hydraulic rear-wheel steering for vehicle - uses electromagnetic valves with clamping circuit in event of system failure

摘要

The steering linkage rod (44) is attached to a piston (45) in the operating cylinder (47). Hydraulic fluid is supplied to either side of the piston through the non-return valve (52) by the pump connected at union (P). One exit from the non-return valve goes directly to one side of the piston, the other goes first through the 3-position steering valve assembly (50) to the other side. The piston works on the differential principle, moving according as to the difference in pressure on either side. A clamping valve (70) also supplied by pressurised fluid allows the steering position to be maintained in the event of failure of either control electronics or of the pump. The union (T) connects with the fluid reservoir. The valves are all electromagnetically operated with a return spring. A feedback circuit can return a position signal to the control electronics. USE/ADVANTAGE - Pressurised hydraulic rear-wheel steering. Feedback circuit with clamping valve give safety against failure of pump or electronics.