| 摘要 |
<p>PURPOSE:To improve operability by decreasing the displacement of a lower- priority oil path switching valve as the displacement of a higher operation priority oil path switching valve is increased, and using the maximum value of an oil path switching valve displacement command signal as a swash plate angle command signal. CONSTITUTION:Operation priority is assigned to oil path switching valves 14a-14d, 15a-15d, 16a-16d. As the displacement of a higher operation priority oil path switching valve is increased, the displacement of a lower priority oil path switching valve is decreased. The maximum value of an oil path switching displacement command signal is used as a swash plate angle command signal for variable-displacement hydraulic pumps 4a-4d. Thus, even if load changes, working fluid is not caused to concentratively flow into a cylinder on low pressure side, so that working fluid corresponding to operating amount can be supplied to each actuator to favorably perform fine operation and interlocking operation.</p> |
