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Patent Searching and Data


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.

Inventors:
OGAWA Yuichi (Hitachi Construction Machinery Co. Ltd., 650, Kandatsumachi, Tsuchiura-sh, Ibaraki 13, 〒3000013, JP)
HIJIKATA Seiji (Hitachi Construction Machinery Co. Ltd., 650, Kandatsumachi, Tsuchiura-sh, Ibaraki 13, 〒3000013, JP)
HOSHINO Masatoshi (Hitachi Construction Machinery Co. Ltd., 650, Kandatsumachi, Tsuchiura-sh, Ibaraki 13, 〒3000013, JP)
Application Number:
JP2017/012474
Publication Date:
October 04, 2018
Filing Date:
March 27, 2017
Export Citation:
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Assignee:
HITACHI CONSTRUCTION MACHINERY CO., LTD. (16-1, Higashiueno 2-chome Taito-k, Tokyo 15, 〒1100015, JP)
International Classes:
F15B21/14; F15B11/08; F15B20/00
Domestic Patent References:
WO2016147283A12016-09-22
WO2016147283A12016-09-22
Foreign References:
JPH06323308A1994-11-25
JPH0258101U1990-04-26
Attorney, Agent or Firm:
KAICHI IP (3-16, Nihonbashi-muromachi 4-chome Chuo-k, Tokyo 22, 〒1030022, JP)
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