Title:
WORK MACHINE
Document Type and Number:
WIPO Patent Application WO/2024/071261
Kind Code:
A1
Abstract:
This work machine comprises a cylinder control valve that controls the flow of hydraulic oil from a hydraulic pump to a hydraulic cylinder, a first pressure reduction valve that reduces the pressure of hydraulic oil discharged from the hydraulic pump to generate pilot primary pressure, a second pressure reduction valve that generates secondary pressure acting on a pressure-receiving part of the cylinder control valve, a bypass cut valve, a third pressure reduction valve that generates secondary pressure acting on a pressure-receiving part of the bypass cut valve, a regeneration passage that connects a meter-in passage and a meter-out passage, a meter-out aperture, and a control device. When the pressure of the hydraulic pump detected by a pressure sensor becomes low, the control device controls the third pressure reduction valve so that the opening area of the bypass cut valve becomes small, and commensurately reduces the opening area of the meter-out aperture as the amount of operation to operate a work device in the direction of gravity increases.
Inventors:
KAYANE MASAHIRO (JP)
KANEHAMA MITSUHIKO (JP)
KANEHAMA MITSUHIKO (JP)
Application Number:
PCT/JP2023/035296
Publication Date:
April 04, 2024
Filing Date:
September 27, 2023
Export Citation:
Assignee:
HITACHI CONSTRUCTION MACH CO (JP)
International Classes:
F15B11/08; E02F9/20; F15B11/044; F15B11/20
Domestic Patent References:
| WO2022195832A1 | 2022-09-22 |
Foreign References:
| JP2011127727A | 2011-06-30 |
Attorney, Agent or Firm:
KAICHI IP (JP)
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