Steering system for motor vehicles with two steering circuits

摘要

The system has a main circuit (1) and an auxiliary circuit (2), each with a tank (3,3'), supply pump (4,4') and steering cylinder (6,6'), whereby the cylinders are mechanically connected and the two circuits are driven by a common hand steering wheel (25). The steering unit has main and auxiliary oil inlets, both connected to a control valve (22) and both closed by non-return valves (26,27) opening towards the control valve, that of the auxiliary circuit having a higher opening pressure. The steering unit has two cylinder connections each for the main and auxiliary circuit steering cylinders. The cylinder lines leading to the auxiliary circuit steering cylinder are connected via opposed reverse suction valves (35,36).