Hydraulic circuit formation of plural actuators and excavating attachment having said circuit



(57)【要約】 【課題】 共通油圧回路によって操作される複数のアク チュエータを優先順位に従って作動させる。さらに、選 択的に特定のアクチュエータだけを作動させる。 【解決手段】 一対の共通油圧回路を複数の対の個別油 圧回路に分岐し、各対の個別油圧回路を個々の油圧アク チュエータに接続した油圧回路において、いずれかの油 圧アクチュエータの一対の個別油圧回路の各々に、他の 油圧アクチュエータの作動油圧よりも高い設定圧で回路 を開くリリーフバルブを設ける。さらに、共通油圧回路 から分岐したリリーフ回路に、前記個別油圧回路のリリ ーフバルブよりも小さい設定圧で回路を開くリリーフバ ルブを設け、該リリーフ回路の油の流れを選択的に停止 させる閉鎖手段を設けてもよい。
PROBLEM TO BE SOLVED: To actuate a plurality of actuators operated through a common hydraulic circuit according to the order of priority, and selectively actuate only a specified actuator. SOLUTION: In a hydraulic circuit where a pair of common hydraulic circuits is branched off into plural pairs of individual hydraulic circuits, and each pair of individual hydraulic circuits is connected to an individual hydraulic actuator, each of a pair of individual hydraulic circuits 7a, 7b of one of hydraulic actuator 9 is provided with a relief valve 11 to open the circut at a set pressure higher than the working oil pressure of another hydraulic actuator. In addition, a relief circuit 5 branched from the common hydraulic circuits 3a, 3b is provided with a relief valve 16 to open the circuit at a set pressure lower than pressure at the relief valve 11 of the individual hydraulic circuit, and may be provided with a closing means 17 for selectively stopping an oil flow in the relief circuit 5. COPYRIGHT: (C)1999,JPO




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Cited By (6)

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    CN-102644304-AAugust 22, 2012日立建机株式会社Deeply excavating excavator
    CN-102644304-BJanuary 13, 2016日立建机株式会社深挖挖掘机
    CN-103255787-AAugust 21, 2013日立建机株式会社Expansion rod and deep drilling machine
    JP-2012172362-ASeptember 10, 2012Hitachi Constr Mach Co Ltd, 日立建機株式会社Deep drilling machine
    JP-2013167107-AAugust 29, 2013Hitachi Constr Mach Co Ltd, 日立建機株式会社伸縮ロッドおよび深掘掘削機
    JP-2013167108-AAugust 29, 2013Hitachi Constr Mach Co Ltd, 日立建機株式会社深掘掘削機の油圧回路