Title:
HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINE
Document Type and Number:
Japanese Patent JP2016014398
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a hydraulic system for a construction machine, capable of suppressing the operating modulation of a front structure, not intended by an operator.SOLUTION: The hydraulic system for the construction machine includes a regeneration hydraulic motor 55 to be driven by return oil from a bottom port BP of a boom cylinder 32, a regeneration electric motor 54 for converting the rotating power of the regeneration hydraulic motor 55 into electric energy, return oil control valves 51-53 for controlling the flow of the return oil depending on a pilot pressure guided from a pilot hydraulic source 45 in association with the operation of a boom operation lever 46, return-oil-control-valve solenoid valves 57-59 for controlling the pilot pressure to drive the return oil control valves 51-53, and malfunction preventing devices 64, 65 for operating with a pressure fluctuation resulting from, for example, the malfunction of the return-oil-control-valve solenoid valve 58 to cut off the transmission of the pilot pressure from the return-oil-control-valve solenoid valve 58 to the return oil control valve 52.
Inventors:
OKI TAKATOSHI
HIJIKATA SEIJI
ISHIKAWA KOJI
HIJIKATA SEIJI
ISHIKAWA KOJI
Application Number:
JP2014135131A
Publication Date:
January 28, 2016
Filing Date:
June 30, 2014
Export Citation:
Assignee:
HITACHI CONSTRUCTION MACHINERY
International Classes:
F15B20/00; E02F9/20; E02F9/22; F15B21/14
Domestic Patent References:
| JP2014095394A | 2014-05-22 |
Foreign References:
| WO2014017492A1 | 2014-01-30 |
Attorney, Agent or Firm:
Kaichi International Patent Office