| 摘要 |
<p>PURPOSE:To enable execution of 4-wheel steering even during failure in operation of a car speed sensor, by a method wherein a steering angle ratio set means having a control mode for a steering angle ratio responding to a car speed and a control mode for a steering angle ratio responding to a front wheel steering angle, and during failure in operation of the car speed sensor, a steering angle ratio is controlled by means of the control mode for a steering angle ratio responding to a front wheel steering angle. CONSTITUTION:In a steering angle ration control mechanism A wherein an input link 14 is linked to a drop arm 8 so as to interlock with a front wheel steering angle mechanism 7, an output link 27 coupled to a control lever 30, pivotally mounted at 23 to a car body, by means of a pin 28 is provided. A rod 31 pivotally supported at 27a to the output link 27 is linked to the valve element of a servo control valve 32 of a rear wheel steering mechanism 34. A gear 17 rotated with the aid of a steering angle ratio control motor 18 is geared with a partial gear 22 on an arc of a circle formed to the output link 27. The steering angle ratio control motor 18 is controlled by an electronic control device 51 according to a steering angle ratio decided according to a control mode for a steering angle ratio responding to a car speed during ordinary running and a control mode for a steering angle ratio responding to a front wheel steering angle during the occurrence of abnormality to a car speed sensor 55.</p> |
