Title:
WORK MACHINE
Document Type and Number:
WIPO Patent Application WO/2021/059571
Kind Code:
A1
Abstract:
Provided is a work machine that is capable of preventing trapping of pump pressure. A hydraulic shovel comprises: a control valve that controls the flow of pressure oil from a hydraulic pump to a hydraulic actuator; an operation device for operating the control valve; a pressure sensor that detects a pilot pressure that corresponds to an amount of operation of the operation device; a regulator that variably controls a capacity of the hydraulic pump; a bleed-off valve disposed on a bleed-off pipeline that returns the pressure oil supplied to the control valve from the hydraulic pump to a tank; and a controller that outputs, according to the pilot pressure detected by the pressure sensor, a pump command current for controlling the capacity of the hydraulic pump, and a bleed-off command current for controlling a degree of opening of the bleed-off valve. In a case where a decrease rate of the pilot pressure is greater than a predetermined value, the controller corrects the bleed-off command current such that the degree of opening of the bleed-off valve increases.
Inventors:
SUZUKI DAISUKE (JP)
Application Number:
PCT/JP2020/017249
Publication Date:
April 01, 2021
Filing Date:
April 21, 2020
Export Citation:
Assignee:
HITACHI CONSTRUCTION MACH CO (JP)
International Classes:
E02F9/22; F15B11/00; F15B11/044
Foreign References:
| JP5886976B2 | 2016-03-16 | |||
| JPH10147959A | 1998-06-02 | |||
| JP2018048503A | 2018-03-29 |
Attorney, Agent or Firm:
KAICHI IP (JP)
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