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Patent Searching and Data


Title:
HYDRAULIC CONTROL DEVICE FOR WORK MACHINE
Document Type and Number:
WIPO Patent Application WO/2020/262073
Kind Code:
A1
Abstract:
Provided is a hydraulic drive device (20) for a work machine with which it is possible to ensure drive pressure for a work actuator in a combined operation state, and to transition suitably from an independent operation state to a combined operation state while suppressing an increase in the speed of a travel motor. The hydraulic drive device (20) is provided with a flow passage switching valve (70) and a flow passage switching control unit for operating this valve. The supply switching valve 70 has a first position (71) for an independent operation state and a second position (73) for a combined operation state and, in the first position (71), is able to form a first flow passage (73a) connected to a first pump (21), a second flow passage (73b) connected to a second pump (22), and a connecting flow passage (73c) connecting the first flow passage (73a) and the second flow passage (73b). When the drive state of a work actuator (45) is not in a permissible range during the combined operation state, the flow passage switching control unit reduces the opening area of the connecting flow passage (73c) to less than when the drive state is within the permissible range.

Inventors:
NAGAI, Masaki
UEDA, Koji
FUJITA, Yuichiro
Application Number:
JP2020/023410
Publication Date:
December 30, 2020
Filing Date:
June 15, 2020
Export Citation:
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Assignee:
KOBELCO CONSTRUCTION MACHINERY CO., LTD. (JP)
International Classes:
F15B11/02; E02F9/22; F15B11/024; F15B11/042; F15B11/17
Attorney, Agent or Firm:
KOTANI, Masataka et al. (JP)
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