Mazda Motor Corporation

Koushun Note

Hirotaka Kanazawa

Yasuhiro Nakashima

Yoshiaki Mukai

Shunji Sakamoto

Takeshi Murai

Shigeo Okamizu

A four-wheel steering apparatus for a vehicle consisting of a steering mechanism that includes a steering wheel. A front wheel turning mechanism is operatively connected to the steering mechanism to turn the front wheels according to the turning angle of the steering wheel. A rear wheel turning mechanism is operatively connected to the steering mechanism to turn the rear wheels in response to operation of the steering wheel. A hydraulically operated power assist is connected with the rear wheels turning mechanism. A rear wheels steering ratio changing mechanism is provided for changing the ratio of the turning angle of the rear wheels with respect to the turning angle of the steering wheel. A return mechanism is provided for returning the rear wheels to a neutral position. A valve mechanism drains the oil applied from an oil pump to the power assist mechanism. An engine stop mechanism is provided for stopping the engine. A control mechanism is provided for controlling the valve mechanism to drain the oil when the engine stop mechanism outputs a signal for stopping the engine. A delay mechanism is provided for delaying the drain of the oil applied from the oil pump to the power assist means.

Four-wheel steering apparatus for vehicle

A vehicle four-wheel steering apparatus including a manually operated steering member and front and rear wheel steering mechanisms coupled with the steering member for producing steering movements in the vehicle front and rear wheels. The rear wheel steering mechanism includes a power assist actuated by an oil pump driven by the vehicle engine. A return spring returns the rear wheels to a neutral position when the power assist is off. A steering condition detector detects the condition of the rear steering mechanism. An engine output power increase mechanism increases the engine output power responsive to a control signal for increasing the engine output power when the rear steering mechanism is actuated.

A four-wheel steering system has a front wheel turning mechanism for turning front wheels in response to operation of a steering wheel, a rear wheel turning mechanism for turning rear wheels, a controller for controlling the rear wheel turning mechanism to turn the rear wheels according to preset four-wheel steering characteristics and a relay shaft which is connected to the controller to transmit turning of the front wheels to the controller. The front wheel turning mechanism and the rear wheel turning mechanism are caused to bring the front wheels and the rear wheels to the respective straight-ahead positions while the relay shaft is disconnected from the controller. Then the controller is brought into the state corresponding to the straight-ahead positions of the front and rear wheels on the basis of the preset four-wheel steering characteristics. Thereafter, the relay shaft is connected to the controller.

Method of incorporating four-wheel steering system in vehicle and

A four-wheel steering system for a vehicle in which the rear wheels of a vehicle are turned in response to the turning of the front wheels of the vehicle upon operation of a steering wheel. The rear wheel steering is derived from the front wheel steering by way of a transmission shaft. The transmission shaft is supported rotatably and for sliding movement in the axial direction by way of a bearing fixed on the vehicle body. A stopper ring is fixed on the transmission shaft a short distance forward from the bearing to limit the backward sliding of the transmission shaft.

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Higashhiroshima, Japan

Koushun Note