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1. (WO2017154186) CONSTRUCTION MACHINE

Pub. No.:    WO/2017/154186    International Application No.:    PCT/JP2016/057680
Publication Date: Fri Sep 15 01:59:59 CEST 2017 International Filing Date: Fri Mar 11 00:59:59 CET 2016
IPC: F15B 11/044
Applicants: HITACHI CONSTRUCTION MACHINERY CO., LTD.
日立建機株式会社
Inventors: AMANO Hiroaki
天野 裕昭
IMURA Shinya
井村 進也
YAMASHITA Ryouhei
山下 亮平
NISHIKAWA Shinji
西川 真司
Title: CONSTRUCTION MACHINE
Abstract:
A hydraulic shovel is provided with an arm cylinder (34) driven by hydraulic oil from a hydraulic pump (23), a meter-out flow channel (L4) through which hydraulic oil expelled from the arm cylinder flows, a control valve (41) for controlling the flow rate of hydraulic oil in the meter-out flow channel, a pressure sensor (SE5) for detecting the load acting on the arm cylinder, a pressure sensor (SE3) for detecting the manipulated variable of an operating device (42) for operating the arm cylinder, and a controller (44). The controller alternatively selects a normal actuation mode in which the opening area of the control valve is controlled on the basis of an actuator load and the manipulated variable, and an alternative actuation mode in which the opening area of the control valve is controlled on the basis of the manipulated variable. When the alternative actuation mode is selected, the controller increases the discharge flow rate of the hydraulic pump above that in the normal actuation mode.