| 摘要 |
<p>PURPOSE:To make a speed transmission ration adjustable with a motor small in output by making a turning angle of the motor so as to be driven and controlled on the basis of the detected value of a speed sensor when the steering angle detected value is less than the value equivalent to the specified steering angle. CONSTITUTION:In a power steering system provided with a power assist mechanism, a second input shaft 12 being connected to a first input shaft 11 by a torsion bar 13 and an output shaft 14 are coupled together by a speed transmission mechanism which consists of a countershaft 15, an angular speed ratio variable gear train A and a speed-up gear train B transmitting its speed to the output shaft 14. A worm gear 33 is rotated and driven by an electric motor 34, through which a speed transmission ratio between these input-output shafts 12, 14 is made variable. The motor 34 is controlled by a controller 53 on the basis of a speed sensor 52 when the detected value of a steering angle sensor 51 is less than the value equivalent to the specified steering angle.</p> |
