HYDRAULIC CONTROL SYSTEM FOR WORKING MACHINE - HITACHI CONSTRUCTION MACH CO

Title:

HYDRAULIC CONTROL SYSTEM FOR WORKING MACHINE

Document Type and Number:

WIPO Patent Application WO/2018/179070

Kind Code:

A1

Abstract:

The objective of the present invention is to provide a hydraulic control system for a working machine with which it is possible to detect an abnormality in a pump output switching device irrespective of the state of the abnormality of the pump output switching device. A hydraulic control system for a hydraulic shovel is provided with: an accumulator 21 connected to an oil line 25A between a pilot pump 17 and a pilot valve 20; an unloading valve 27, which is a pump output switching device; a pressure sensor 29 which detects the pressure of hydraulic oil supplied to the pilot valve 20; and a controller 30 including a pump output control unit 31 which switches the unloading valve 27 in accordance with the pressure detected by the pressure sensor 29. The controller 30 additionally includes an abnormality determining unit 32 which calculates a command continuation time of a state in which a command output to the unloading valve 27 does not change, determines that there is an abnormality in the unloading valve 27 if the command continuation time is equal to or greater than a prescribed value, and outputs the determination result.

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Inventors:

OGAWA YUICHI (JP)
HIJIKATA SEIJI (JP)
HOSHINO MASATOSHI (JP)

Application Number:

PCT/JP2017/012474

Publication Date:

October 04, 2018

Filing Date:

March 27, 2017

Export Citation:

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Assignee:

HITACHI CONSTRUCTION MACH CO (JP)

International Classes:

F15B21/14; F15B11/08; F15B20/00

Domestic Patent References:

WO2016147283A1	2016-09-22
WO2016147283A1	2016-09-22

Foreign References:

JPH06323308A	1994-11-25
JPH0258101U	1990-04-26

Other References: