| 摘要 |
PURPOSE:To perform optimum rear wheel steering according to both front wheel steering angles and vehicle speeds from low to high vehicle speeds by changing control pulse frequencies applied to a stepping motor working as a power source of a rear wheel steering device based on vehicle speed information. CONSTITUTION:In a front wheel steering mechanism 1 of a four wheel steering device, a rack rod 5 is laterally reciprocated by the turn of a steering wheel 2 through a gear box 4 so that a front wheel 9 is steered through both a tie-rod 6 and a knuckle arm 7. A rear wheel steering mechanism 10 on the other hand is constituted with a power steering mechanism 13 powered by a stepping motor 12 controlled by a control device 11. In the above constitution, the control device 11 is equipped with a memory storing multiple pulse characteristic tables to be selected according to vehicle speeds and changes frequencies of control pulses generated in a control pulse generating unit and applied to the motor 12 by the use of the pulse characteristic table selected according to the vehicle speed. |
