Patent ID: 6681884
Filing Date: 2004-01-27
Classification: B62D

Abstract:
A power steering system, characterised by:a steering valve (9) for controlling a power cylinder (8); a variable orifice (a) provided upstream from the steering valve (9); a solenoid (SOL) for controlling a degree of opening of the variable orifice (a); a controller (C) for controlling a solenoid current instruction value (SI) used for driving the solenoid (SOL); a steering angle sensor (14) and a vehicle speed sensor (15) which are connected to the controller (C); and a flow control valve (V) for distributing a flow supplied from a pump (P), to a control flow supplied to the steering valve (9) in accordance with the degree of opening of the variable orifice (a), and a return flow circulating back to a tank (T) or the pump (P), and in that the controller (C) stores a table of basic current instruction values (I1) corresponding to combinations of steering angles and steering angular velocities, and multiplies the basic current instruction value (I1), obtained from the table, by a current instruction value (I2) set on the basis of a vehicle speed for determination of the solenoid current instruction value (SI).