| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent generation of rolling in a power vehicle in the direction opposite to the required running direction by using one of control circuits for an automatic clutch, also as a control circuit for a hill holder. SOLUTION: A hill holder is buit in an auxiliary hydraulic control circuit 6, and when an automatic clutch is controlled by a main hydraulic control circuit 3 in a specified manner, the hill holder is operated. In the case of failure in the circuit 3, the circuit 6 controls the automatic clutch. Two changeover valves 4, 5 control the automatic clutch in stead of pressure reducing part 18 and increasing part 19 of the circuit 6 controlled the hill holder so far, and the hill holder is changeover to an oil tank 7 with no pressure by means of a hydraulic pressure changeover valve 4. Accordingly the drive software for a hydraulic element and a clutch controller can utilize for the function of hill holder.</p> |
