To provide a hydraulic circuit of a working machine which can surely brake a turning motor.SOLUTION: A hydraulic circuit of a working machine comprises: an engine (22); a main pump (23); a pilot pump (27); a turning hydraulic motor (24) driven by a working fluid discharged from the main pump; a direction control valve (41) for controlling a flow direction of the working fluid supplied to the turning hydraulic motor from the main pump; and a flow rate adjustment valve (43) for adjusting a flow rate of the working fluid supplied to the direction control valve from the main pump. The hydraulic circuit also comprises a flow rate adjustment valve control part (70) arranged at a discharge side of the pilot pump, creating command pressure (Pgr') with the discharge pressure of the pilot pump as primary pressure on the basis of an operation of an operation member (37) for braking the turning hydraulic motor, and controlling the flow rate adjustment valve to a direction in which the flow rate adjustment valve is closed by the command pressure.SELECTED DRAWING: Figure 2

    【課題】確実に旋回モータに制動をかけることができる作業機械の油圧回路を提供する。【解決手段】エンジン(22)と、メインポンプ(23)と、パイロットポンプ(27)と、メインポンプから吐出される作動油により駆動される旋回用油圧モータ(24)と、メインポンプから旋回用油圧モータへ供給される作動油の流れ方向を制御する方向制御弁(41)と、メインポンプから方向制御弁に供給される作動油の流量を調節する流量調節弁(43)とを備えた作業機械の油圧回路において、パイロットポンプの吐出側に設けられ、旋回用油圧モータに制動をかけるための操作部材(37)の操作に基づいて、パイロットポンプの吐出圧を一次圧として指令圧(Pgr´)を生成し、指令圧により流量調節弁を閉じる方向に制御する流量調節弁制御部(70)を備えている。【選択図】図2


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    Title :

    HYDRAULIC CIRCUIT OF WORKING MACHINE


    Additional title:

    作業機械の油圧回路


    Contributors:

    Publication date :

    2019-10-10


    Type of media :

    Patent


    Type of material :

    Electronic Resource


    Language :

    Japanese


    Classification :

    IPC:    F16H Getriebe , GEARING / B66C Krane , CRANES / F15B SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL , Druckmittelbetriebene Systeme allgemein



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