To provide a working machine that has a simple structure, and can quickly control a counter balance valve.SOLUTION: A working machine comprises a hydraulic actuator (2) to be driven by pressure oil, and a counter balance valve (10) interposed in a return side oil passage (4a) of the hydraulic actuator. The counter balance valve comprises: a first oil chamber (24) to which the pressure oil is guided; a second oil chamber (25) to which the pressure oil is guided independently of the first oil chamber, and in which an internal pressure is changed depending on a pressure of the first oil chamber; and flow rate control means (35) for controlling a flow rate of the pressure oil flowing to the return side oil passage from the second oil chamber depending on a pressure of the pressure oil on an input side of the counter balance valve.SELECTED DRAWING: Figure 2
【課題】簡易な構成でカウンタバランス弁を迅速に制御可能な作業機械を提供する。【解決手段】圧油によって駆動する油圧アクチュエータ(2)と、油圧アクチュエータの戻り側油路(4a)に介装されるカウンタバランス弁(10)と、を備えた作業機械において、カウンタバランス弁は、圧油が導かれる第1油室(24)と、第1油室とは別に圧油が導かれ、前記第1油室の圧力に応じて内部の圧力が変化する第2油室(25)と、カウンタバランス弁の入力側の圧油の圧力に応じて第2油室から戻り側油路へ流れる圧油の流量を制御する流量制御手段(35)と、を備えることを特徴とする。【選択図】図2
WORKING MACHINE AND COUNTER BALANCE VALVE
作業機械およびカウンタバランス弁
2020-10-08
Patent
Electronic Resource
Japanese