| 摘要 |
<p>PURPOSE:To improve safety by automatically intercoupling a handle and a steering link through a drive force transmission mechanism and converting a rotation amount of the handle to a movement amount of the steering link when operation by a hydraulic servo system is not carried out due to the occurrence of failure in operation to the hydraulic circuit of a hydraulic servo. CONSTITUTION:When a handle 10 is steered, a valve rotor 12 is rotated based on a valve sleeve 13 to open a servo valve A. A power cylinder B is operated according to the steering direction of the handle 10, and a steering link 20 is driven to steer wheels. When a hydraulic circuit containing a servo valve A is failed in operation and the oil pressure of an oil pressure feed circuit is decreased to a value lower than a set value, through operation by an above- mentioned hydraulic system is not executed, a lock mechanism F automatically brings a carrier 53 of a planetary gear E into a lock state. Thereby, a drive force is transmitted through the planetary gear E, and a rotation amount of the handle 10 is converted into a movement amount of the steering link 20 in a steering gear ratio set by each gear of the planetary gear E to transmit the movement amount.</p> |
