WORK MACHINE - HITACHI CONSTRUCTION MACH CO

Title:

WORK MACHINE

Document Type and Number:

WIPO Patent Application WO/2022/014606

Kind Code:

A1

Abstract:

This work machine comprises: a hydraulic actuator driven by pressurized oil from a hydraulic pump; an open center-type direction control valve which is disposed on a center bypass line and controls the flow of the pressurized oil supplied to the hydraulic actuator; a CB cut-off valve disposed on the center bypass line between the direction control valve and a hydraulic oil tank; and a machine body controller which controls the degree of opening of the CB cut-off valve. The machine body controller narrows the degree of opening of the CB cut-off valve in a case where an operation on the hydraulic actuator is in a fine operation state within a predetermined range exhibiting a fine operation region and the fine operation state has continued beyond a predetermined period. In all other cases, the machine body controller sets the CB cut-off valve to be fully open.

Inventors:

HOSHINO MASATOSHI (JP)
HIJIKATA SEIJI (JP)
TSURUGA YASUTAKA (JP)

Application Number:

PCT/JP2021/026349

Publication Date:

January 20, 2022

Filing Date:

July 13, 2021

Export Citation:

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Assignee:

HITACHI CONSTRUCTION MACH CO (JP)

International Classes:

F15B11/00; E02F9/22

Domestic Patent References:

WO2018207268A1	2018-11-15
WO2014061741A1	2014-04-24

Foreign References:

JP2011085159A	2011-04-28
JPH09247515A	1997-09-19
JPH0713605A	1995-01-17
JP2012057409A	2012-03-22
JP2001082410A	2001-03-27

Other References: