HYDRAULIC DRIVE DEVICE FOR WORK MACHINE

WIPO Patent Application WO/2020/031974

A1

Provided is a hydraulic drive device for a work machine with which the frequency of maintenance can be reduced. A controller (20) opens a first opening/closing valve (25a), closes a second opening/closing valve (25b), switches a first direction switching valve (30a) to a first position (A), and switches a second direction switching valve (30b) to a third position (C), whereby pressure oil from a hydraulic pump (1a) is supplied from the first opening/closing valve to an actuator (5a) via the first direction switching valve. When history information of the first opening/closing valve is assessed to satisfy a prescribed condition, the controller closes the first opening/closing valve, opens the second opening/closing valve, switches the first direction switching valve to a second position (B), and switches the second direction switching valve to a fourth position (D), whereby pressure oil from the hydraulic pump is supplied from the second opening/closing valve to the actuator via the second direction switching valve. For example, the controller determines that the prescribed condition is satisfied when the number of operations of the first opening/closing valve has reached a first prescribed value.

WO/2020/194528	FAILURE DIAGNOSTIC SYSTEM AND FAILURE DIAGNOSTIC METHOD
JP3788604	MECHANICAL CONTROL DEVICE OF SERVO-ACTUATOR

TAKIMOTO YOSHIFUMI (JP)
TAKIGUCHI KAZUO (JP)
IIO CHINORI (JP)
OKAMURA JUN (JP)
TAKAHASHI HIROMASA (JP)

PCT/JP2019/030767

February 13, 2020

August 05, 2019

Click for automatic bibliography generation  

HITACHI CONSTRUCTION MACH CO (JP)

F15B20/00; E02F9/22; F15B11/02

JP2008127129A	2008-06-05
EP2982868A1	2016-02-10
JP2017053383A	2017-03-16

See also references of EP 3744988A4

THE PATENT BODY CORPORATE TAKEWA INTERNATIONAL PATENT OFFICE (JP)

View/Download PDF      PDF Help

Previous Patent: FLUID LEAK DETECTING SYSTEM

Next Patent: CATALYST-COATED GASOLINE PARTICULATE FILTER AND METHOD FOR PRODUCING SAME