| 摘要 |
<p>PURPOSE: To perform reliable traveling even if an automatic controller fails, by controlling front wheels and rear wheels in the end position of a transmission member for controlling a transmission ratio in the same direction by a transmission at a high transmission ratio. CONSTITUTION: In a transmission 5, an oscillating frame 12 is rotated through a wheel 14 and shaft pin 13 by turning of a front wheel steering device in relation to a case 11, and a moving bar 15 as an output element is moved through a coupling pin 13. A coupling shaft 17 is upward or downward moved by a piston 2 according to the traveling speed of the vehicle, and a transmission ratio is changed. When a controller 8 detects a failure, a piston operating space 24 has no pressure, the coupling shaft 17 is upward moved by a return spring 23, and the piston 22 is restricted in the end positions. Accordingly, the transmission 5 inevitably has a maximum transmission ratio. Therefore, safety can be secured in all situations.</p> |
