Jtekt Corporation

Tetsuya Ozaki

Masahiko Sakamaki

Akihiko Shiina

Ryouichi Kubo

Yasuhiro Tomagou

Hiroyasu Inoue

A hydraulic power steering system includes: a hydraulic cylinder in which an interior is partitioned into first and second hydraulic chambers by a piston on a steered shaft; a variable displacement electric pump that supplies hydraulic fluid to the hydraulic cylinder; a selector valve selectively set in a mode in which the hydraulic fluid is supplied to the first hydraulic chamber and drained from the second hydraulic chamber or in a mode in which the hydraulic fluid is supplied to the second hydraulic chamber and drained from the first hydraulic chamber; a detector that detects torque, steering angle, and/or vehicle speed; and a controller.

Hydraulic power steering system

A hydraulic power steering apparatus assists in steering of a vehicle with a hydraulic cylinder. The hydraulic power steering apparatus includes a flow control valve, a steering torque sensor, a steering angle sensor, a vehicle speed sensor, and an ECU. The flow control valve changes the supply/drainage amount of hydraulic fluid for the hydraulic cylinder. The ECU sets a supply/drainage mode for supplying/draining the hydraulic fluid with respect to the hydraulic cylinder based on detection results from the aforementioned sensors and controls the flow control valve in accordance with the supply/drainage mode of the hydraulic fluid.

Hydraulic power steering apparatus

In an electric power steering device, if the temperature of a specific site that increases due to the driving of a steering assist motor exceeds a threshold, the motor current is controlled to be equal to or below a current restriction value. The temperature Toff of the specific site detected when an engine is stopped, and the current restriction value Ioff provided when the engine is stopped are stored into a storage. A temperature difference Ta between the temperature detected when a starter switch is turned on and the temperature Toff is computed. If the temperature of the specific site when the starter switch is turned on is above the threshold, the current restriction value is set to be equal to or above the current restriction value Ioff stored in the storage, according to the temperature difference Ta, over a time following the turning-on of the starter switch.

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Kitakatsuragi-gun, Japan

Tetsuya Ozaki