Patent ID: 9511796
Filing Date: 2016-12-06
CPC Classification: B62D

Claim Text:
1. A power steering system comprising: an electric power steering including a motor serving as an electric actuator that generates a first steering assist force based on a torsion amount of a first torsion bar to which steering torque is applied; a hydraulic power steering including an electric valve that provides or interrupts communication between a supply path through which the hydraulic fluid is supplied to the control valve and a drain path through which the hydraulic fluid is drained from the control valve; and a controller that adjusts the flow rate of the hydraulic fluid that is supplied to the control valve by controlling an opening degree of the electric valve, wherein the second torsion bar has a torsional stiffness that is equal to or substantially equal to a torsional stiffness of the first torsion bar, and wherein the controller fully closes the electric valve when the electric power steering malfunctions.