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HYDRAULIC PRESSURE CONTROL SYSTEM IN WORK MACHINE
To enable an electromagnetic proportional valve for outputting pilot pressure to two control valves to be shared even though the two control valves perform different operation in accordance with an operation tool operation amount.SOLUTION: Only a directional control valve for a boom is opened and a flow rate control valve for a boom is closed in the case that output pilot pressure from an electromagnetic proportional valve for a boom is less than second setting pilot pressure, and both the directional control valve for a boom and the flow rate control valve for a boom are opened in the case of being the second setting pilot pressure or more by providing a sharing electromagnetic proportional valve 41 for a boom for outputting pilot pressure in accordance with an operation tool operation amount of a boom rise side to both a directional control valve 23 for a boom and a flow rate control valve 29 for a bloom for performing supply flow rate control to a boom cylinder 8, and setting second setting pilot pressure at which a supply valve passage 29a of the flow rate control valve for a boom starts to open to pressure higher than first setting pilot pressure at which a supply valve passage 23a of the directional control valve for a boom starts to open.SELECTED DRAWING: Figure 2
【課題】操作具操作量に応じて異なる動作をする二つの制御弁であっても、これら二つの制御弁にパイロット圧を出力する電磁比例弁を共用できるようにする。【解決手段】ブームシリンダ８への供給流量制御を行うブーム用方向切換弁２３およびブーム用流量制御弁２９の両方に、ブーム上昇側の操作具操作量に応じてパイロット圧を出力するブーム用共用電磁比例弁４１を設けるとともに、ブーム用流量制御弁の供給用弁路２９ａが開口開始する第二設定パイロット圧を、ブーム用方向切換弁の供給用弁路２３ａが開口開始する第一設定パイロット圧よりも高圧に設定することで、ブーム用共用電磁比例弁からの出力パイロット圧が第二設定パイロット圧未満の場合にはブーム用方向切換弁のみが開いてブーム用流量制御弁は閉じ、第二設定パイロット圧以上の場合にはブーム用方向切換弁、ブーム用流量制御弁の両方が開く構成にした。【選択図】図２
HYDRAULIC PRESSURE CONTROL SYSTEM IN WORK MACHINE
To enable an electromagnetic proportional valve for outputting pilot pressure to two control valves to be shared even though the two control valves perform different operation in accordance with an operation tool operation amount.SOLUTION: Only a directional control valve for a boom is opened and a flow rate control valve for a boom is closed in the case that output pilot pressure from an electromagnetic proportional valve for a boom is less than second setting pilot pressure, and both the directional control valve for a boom and the flow rate control valve for a boom are opened in the case of being the second setting pilot pressure or more by providing a sharing electromagnetic proportional valve 41 for a boom for outputting pilot pressure in accordance with an operation tool operation amount of a boom rise side to both a directional control valve 23 for a boom and a flow rate control valve 29 for a bloom for performing supply flow rate control to a boom cylinder 8, and setting second setting pilot pressure at which a supply valve passage 29a of the flow rate control valve for a boom starts to open to pressure higher than first setting pilot pressure at which a supply valve passage 23a of the directional control valve for a boom starts to open.SELECTED DRAWING: Figure 2
【課題】操作具操作量に応じて異なる動作をする二つの制御弁であっても、これら二つの制御弁にパイロット圧を出力する電磁比例弁を共用できるようにする。【解決手段】ブームシリンダ８への供給流量制御を行うブーム用方向切換弁２３およびブーム用流量制御弁２９の両方に、ブーム上昇側の操作具操作量に応じてパイロット圧を出力するブーム用共用電磁比例弁４１を設けるとともに、ブーム用流量制御弁の供給用弁路２９ａが開口開始する第二設定パイロット圧を、ブーム用方向切換弁の供給用弁路２３ａが開口開始する第一設定パイロット圧よりも高圧に設定することで、ブーム用共用電磁比例弁からの出力パイロット圧が第二設定パイロット圧未満の場合にはブーム用方向切換弁のみが開いてブーム用流量制御弁は閉じ、第二設定パイロット圧以上の場合にはブーム用方向切換弁、ブーム用流量制御弁の両方が開く構成にした。【選択図】図２
HYDRAULIC PRESSURE CONTROL SYSTEM IN WORK MACHINE
作業機械における油圧制御システム
NAKAJIMA HIDEKI (author) / KIYASU KOICHI (author)
2023-04-11
Patent
Electronic Resource
Japanese
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