Automotive four wheel steering system.

摘要

An automative vehicle having a fluid-operated, four wheel steering system for steering not only the front wheel pair (1), but also the rear wheel pair (4) as a function of the amount of turn of the front wheel pair (1) with respect to the direction of straightforward run of the vehicle. The system makes use of a front cylinder (16) operatively associated with a steering gear assembly and a rear cylinder (27) operated by a fluid medium supplied from the front cylinder (16) for steering the rear wheel pair (4). In order for the steering system to be responsive to the vehicle running speed thereby to control the amount of turn of the rear wheel pair (4) appropriate for a particular range of vehicle running speed, a device (46) is provided for accommodating a portion of the fluid medium to be supplied to the rear cylinder (27) when the pressure of the fluid medium increases to a value higher than a predetermined pressure. Increase of the fluid pressure over the predetermined value takes place when the steering wheel (2b) is turned during the low speed run of the vehicle.