| 摘要 |
<p>PURPOSE:To ensure auxiliary power only when necessary with a simple structure by installing a preset spring between the input/output shafts of a steering shaft and providing an actuator which receives turning force from the input shaft and which outputs an auxiliary power to the output shaft. CONSTITUTION:As the steering load of a steering shaft 20 becomes above the pre-load of a preset spring 81 installed between an input shaft 21 and an output shaft 27, the input shaft 21 is precedingly rotated generating difference in the rotation phase between the input/output shafts 21, 27. Thereupon, the spool rod 34 pivotally installed on a spool lever 72 and the spool valve 33 of a power- assisting actuator 30 which is one with the input shaft 21 are moved rearward. As a result, oil is fed under pressure to the rear oil pressure chamber of a cylinder 42 moving a piston 43 forward while moving the body side of the actuator 30 rearward. Thereby, power is transmitted to the output shaft 27 via a center arm 75 to lighten a steering force.</p> |
