ELECTRONIC CONTROLLED POWER STEERING APPARATUS OF VEHICLE

摘要

PURPOSE: An electronic control power assistance steering system of a vehicle which can reduce noise of a solenoid is provided to support operating force with the power of a motor by mounting a motor and an electronic control unit in a rack bar or a column instead of a hydraulic pump and a working cylinder. CONSTITUTION: An electronic control power assistance steering system of a vehicle comprises a flow load conversion valve, a first valve(710), a second valve(720), a solenoid(217), and an electronic control unit. The flow load conversion valve changes the flow path of the working fluid. The first valve provides the working fluid from the hydraulic pump and controls the maximum pressure of the working fluid. The second valve supplies the working fluid provided from the first valve through the reaction force port to the fluid pressure reaction force part of the flow load conversion valve. The solenoid adds pressure to the second valve in order to supply the working fluid to the fluid pressure reaction force part. The electronic control unit multiplies the duty ratio of the square wave through the pulse width modulation.