Abstract: In a power steering apparatus provided with a damper valve, a second valve apparatus of the damper valve is provided with a valve plate in contact with and apart from a partition member so as to open and close a through flow passage provided in the partition member, and a fluid storing recess portion is provided in a contact area between the partition member and the valve plate.

Abstract: In a power steering apparatus provided with a damper valve, the damper valve holds a partition member between a cap and the housing.

Abstract: A hydraulic power steering apparatus for a vehicle is provided with a main control valve in which a valve opening degree is controlled on the basis of a relative movement between an input shaft interlocking with a steering wheel and an output shaft interlocking with a steering mechanism for turning a steered wheel, a power cylinder mechanism generating a steering assist force, a pump apparatus discharging a fixed flow amount of working oil, a first flow passage including a supply passage communicated with the main control valve, and a control unit controlling an assist control valve. The main control valve controls a supply amount of the working oil in the first flow passage to the power steering apparatus, and the assist control valve controlling a flow amount of a part of the working oil discharged from the pump apparatus is controlled to a set valve opening degree set on the basis of a vehicle speed and an oil pressure of the working oil in the first flow passage, by the control unit.

Abstract: In a control valve of a power steering apparatus, mutually adjacent longitudinal grooves are formed at an inner surface of a sleeve, and each upper end of longitudinal grooves is arranged in a stagger layout, and each lower end thereof is arranged in a stagger layout.

Abstract: A hydraulic power steering apparatus for a vehicle is provided with a main control valve in which a valve opening degree is controlled on the basis of a relative movement between an input shaft interlocking with a steering wheel and an output shaft interlocking with a steering mechanism for turning a steered wheel, a power cylinder mechanism generating a steering assist force, a pump apparatus discharging a fixed flow amount of working oil, a first flow passage including a supply passage communicated with the main control valve, and a control unit controlling an assist control valve. The main control valve controls a supply amount of the working oil in the first flow passage to the power steering apparatus, and the assist control valve controlling a flow amount of a part of the working oil discharged from the pump apparatus 1 is controlled to a set valve opening degree set on the basis of a vehicle speed and an oil pressure of the working oil in the first flow passage, by the control unit.

Abstract: A damper valve for a hydraulic power steering device is disposed in a hydraulic oil circuit connecting an oil passage changing-over valve in a gear box and left and right oil chambers of a power cylinder. It is provided with a piston valve which is opened by through-flow of hydraulic oil returned back to the oil passage changing-over valve from either one of the left and right chambers of the power cylinder, and a check valve which is disposed in a valve body of the piston valve and which allows only hydraulic oil supplied from the oil passage changing-over valve to either one of the left and right chambers of the power cylinder to flow through the check valve. The piston valve is structured such that a throttle oil passage is formed by through flow of the returned hydraulic oil having an oil pressure of a predetermined value or less, and a fully opened oil passage is formed by through flow of the returned hydraulic oil having an oil pressure of more than the predetermined value.