| 摘要 |
PURPOSE:To control a motor for slewing a construction machine when engine is stopped during the slewing period by a method in which when discharge amounts of a pilot pump are lowered to less than a given pressure, an accumulator is led to the discharge circuit of the pilot pump. CONSTITUTION:A main pump 2 and an accumulator 15 are connected through a main circuit 5 to a slewing motor 4 to be controlled by a servo valve 7, and a pilot pump 3 is connected through an operating valve 9 to the controller of the valve 7. In such a liquid-pressure slewing circuit, the accumulator 15 is connected to the discharge circuit of the pump 3 through a reducing valve 17 and a check valve 18. When an engine 1 is stopped during slewing operation, the discharge pressure of the pump 3 is lowered, and pressure stored in the accumulator 15 is sent through the valves 17 and 18 into the discharge circuit. The slewing motor 4 can thus be controlled by valve 9 in spite of the stoppage of the engine 1. |
