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Patent Searching and Data


Title:
CONSTRUCTION MACHINERY
Document Type and Number:
WIPO Patent Application WO/2019/054234
Kind Code:
A1
Abstract:
Provided is construction machinery with which it is possible to suppress the unintended operation of a hydraulic actuator even when a double discharge pump breaks down in a hydraulic closed circuit system. A hydraulic closed circuit system (200) is provided with pressure sensors (62a, 62b) for detecting the drain pressure of working oil discharged from drain ports (60a, 60b) of a plurality of double discharge pumps (10a, 10b). When, among the plurality of double discharge pumps, there exists a double discharge pump the drain pressure of which that was detected by the pressure sensors exceeds a prescribed pressure, a controller (40) determines that the double discharge pump the drain pressure of which exceeds a prescribed pressure is a broken double discharge pump and closes all of the selector valves, among a plurality of selector valves (11a, 11b, 12a, 12b), that are connected to the broken double discharge pump.

Inventors:
KAI Takamasa (6-6, Marunouchi 1-chome, Chiyoda-k, Tokyo 80, 〒1008280, JP)
HIRAKU Kenji (HITACHI CONSTRUCTION MACHINERY CO. LTD., 650, Kandatsumachi, Tsuchiura-sh, Ibaraki 13, 〒3000013, JP)
TAKAHASHI Hiromasa (HITACHI CONSTRUCTION MACHINERY CO. LTD., 650, Kandatsumachi, Tsuchiura-sh, Ibaraki 13, 〒3000013, JP)
SAITOH Teppei (6-6, Marunouchi 1-chome, Chiyoda-k, Tokyo 80, 〒1008280, JP)
Application Number:
JP2018/032747
Publication Date:
March 21, 2019
Filing Date:
September 04, 2018
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:
F15B20/00; E02F9/22; E02F9/24; F15B11/02
Foreign References:
JP2017115994A2017-06-29
JP2008196403A2008-08-28
JPS6317421U1988-02-05
Attorney, Agent or Firm:
KAICHI IP (3-16, Nihonbashi-muromachi 4-chome Chuo-k, Tokyo 22, 〒1030022, JP)
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