| 摘要 |
<p>PURPOSE:To accord with respective neutral position of a steering handwheel and a steering wheel at all times by connecting respective ball nuts of two ball screw mechanisms installed in a steering force transmission system in series with a level member, changing the length of an arm of this lever member to some extent, and making a steering angle ratio so as to be varied. CONSTITUTION:This variable steering angle ratio steering system connects an input shaft 12 coupled with a steering 13 and an output shaft 14 coupled with a steering gear mechanism via both first and second ball screw mechanisms 20, 30 housed in a common case 11 and a transmission mechanism 40 which is provided with a rocking member (lever member) 42 supported in the case 11 free of rocking motion and a rotational member 43 installed free of relative rotation on an outer circumference of a ball nut 32 and shiftably as one body in the axial direction, and this rotational member 43 is rotated by a drive motor 50, and a guide pin 43a of this rotational member 43 is slidden on a sliding bearing 44 of the sliding member 42, through which the length of an arm to the rotational member 43 of the sliding member 42 is varied, thus rectilinear motion of each of ball nuts 22, 23 is shifted and, what is more, a steering angle ratio is varied as well.</p> |
