| 摘要 |
<p>PURPOSE:To cause a hydraulic shovel to travel at speed lower than the normal speed by dividing pressure oil of a pump into equal halves using a traveling motor when solenoid switching valves are switched and only travelling of the shovel in right and left directions is controlled simultaneously. CONSTITUTION:When a solenoid switching valve 52 is switched from its normal position 52a to a position 52b hydraulic lines 54, 55 for signals are communicated with respective portions of a pilot pump 31 and hydraulic lines 32e, 53 for signals are communicated with respective portions of the pump 31 via the throttle 56 of the valve 52. When an operator switches right and left travelling switching valves 11, 12 auxiliary switching valves 21, 22 block respective hydraulic lines 32a, 32b for signals and pressure is generated in a hydraulic line 32d for signals by the throttle 56 of the valve 52. At the same time a rectilinear travelling valve 19 is switched to a position 19b and equal pressure is generated in signal lines 54, 55 via the position 52b and switching valves 50, 51 are switched to respective positions 50b, 51b. Further a help from the valve 11 to the pump 1 is blocked and the pump 2 drives the valves 11, 12 in parallel and causes a hydraulic shovel to travel at half the normal speed.</p> |
