| 摘要 |
A power steering system which minimizes control flow supplied to a valve mechanism when a steering assist force is not required and thereby reduces energy loss and which also prevents a deterioration in steering feeling occurring when the control flow changes. A valve mechanism V is made up of a power cylinder control valve for controlling a control flow and distributively supplying it to a power cylinder Q and a bypass control valve for bypassing the two pressure chambers of the power cylinder C; the bypass control valve is normally closed, but while the control flow Q is being increased from a minimum flow Q1 to a flow Q2 required for an assist force the bypass control valve opens and bypasses the two pressure chambers of the power cylinder C so that the pressure difference between the pressure chambers rises more gently than the control flow and the driver does not experience a feeling of the steering wheel suddenly being taken over. <IMAGE> |
