Search International and National Patent Collections

1. (WO2018163821) CONSTRUCTION MACHINE

Pub. No.:    WO/2018/163821    International Application No.:    PCT/JP2018/006200
Publication Date: Fri Sep 14 01:59:59 CEST 2018 International Filing Date: Thu Feb 22 00:59:59 CET 2018
IPC: E02F 9/22
Applicants: HITACHI CONSTRUCTION MACHINERY CO., LTD.
日立建機株式会社
Inventors: KANETA Tomoaki
金田 朋晃
NARAZAKI Akihiro
楢▲崎▼ 昭広
KODAKA Katsuaki
小高 克明
Title: CONSTRUCTION MACHINE
Abstract:
The present invention addresses the problem of preventing an increase/decrease in pump flow rate due to a load fluctuation caused by a change in the posture of a work attachment and improving operability in an arm pressing operation. A hydraulic shovel 1 provided with a front mechanism including an arm 33 driven by a hydraulic actuator 43 by means of an operation of an operation lever 50 is provided with: first and second angle sensors 37, 38 for detecting the posture of the arm 33; and a controller 49 which, when the posture of the arm 33 is located farther away from a rotation body 20 than a preset position, and a bucket 35 is aligned on the basis of an operation amount preset to be equal to or close to the maximum operation amount of the operation lever 50 in the arm pressing operation by the operation lever 50, drives a hydraulic pump 41 by transitioning the flow rate characteristic of a pressure oil, with respect to a discharge pressure of the hydraulic pump 41 supplying the pressure oil to the hydraulic actuator 43, into a characteristic PTS having a flow rate higher than that of a flow rate characteristic PT when operating exclusive of the operation amount.