摘要 |
PROBLEM TO BE SOLVED: To reduce fuel consumption by reducing a load acting on an engine by automatically lowering a pilot primary pressure without asking operator' help when a machine is not operated. SOLUTION: A pilot primary oil passage 12 extending from a pilot hydraulic power source 11 to a remote control valve 13 is provided with a branch oil passage 20 communicating with a tank 17. An electromagnetic valve 21 is located in the branch oil passage 20, and also a relief valve 23 is located in the downstream side of the electromagnetic valve 21. When a non-operation state of the construction machine is detected by an operation detecting means 19, the pilot primary pressure is lowered by opening the branch oil passage 20 by switching the electromagnetic valve 21 through the control of a controller 30. COPYRIGHT: (C)2004,JPO&NCIPI
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