11lfskraftlenkung für Kraftfahrzeuge

摘要

The invention concerns a servo-assisted steering system for vehicles, the system having at least one steerable, rigid rear axle (1) steered by at least two cylinder-piston units (5, 6) which can be acted on hydraulically. Each of the cylinder-piston units (5, 6) is disposed on one side of the rear axle (1) and is connected in hinged manner at one end to a frame (4) of the vehicle and, at the other, to the rear axle (1). The rear axle (1) is articulated in its upper region on the vehicle frame (4) by means of an A-frame arm (2) in a bearing head (3). The two cylinder-piston units (4, 5) are controlled such that, when the vehicle is travelling in a straight line, both cylinder-piston units (5, 6) are completely retracted and, on cornering, only the cylinder-piston unit (5, 6) on the outside of the curve is adjusted, whilst the cylinder-piston unit (6, 5) on the inside of the curve remains in its retracted position. In this way, the articulation point (7, 8) of the cylinder-piston unit (5, 6) on the inside of the curve forms a swing centre which, together with the bearing head (4) of the A-frame arm (2), forms an axis of rotation for the steering of the rear axle (1). A working circuit (14) and a centring circuit (25) are provided for controlling the cylinder-piston units (5, 6).