| 摘要 |
PURPOSE:To produce an enough brake force by means of the back pressure of a hydraulic motor for running during running on a descending slope by a method wherein a motor control means performs control so that a push-aside volume is maximized when it is decided based on a detecting value from a detecting means that a vehicle is in a state to run down on a slope. CONSTITUTION:In a controller 23, when strokes S of two control valves 4 and 5 detected by stroke sensors 22a and 22b are lower than a preset value So (in the case of S<So), since an operator controls the control valves 4 and 5 with a low stroke for safety during running down on a slope, it is decided that a vehicle is in a state to run down on a slope, and an ON signal is outputted to a solenoid valve 18. The swash plates of hydraulic motors 8 and 9 for running are switched to a high inclination angle. A brake force represented by a product of the back pressures of the motors 8 and 9, i.e. a main line pressure 6a on the delivery side or the circuit pressures of 6b and 7a or 7b, and the inclination angle of the swash plate is increased according to setting of 8 high inclination angle to produce an enough brake force. As a result, the vehicle runs down on a slope with safety without running away on a slope. |
