Title:
WORK MACHINE
Document Type and Number:
WIPO Patent Application WO/2020/183891
Kind Code:
A1
Abstract:
According to the present invention, a connection switching device (45) connects a bottom-side oil chamber (15C) of a boom cylinder (15) and a bottom-side oil chamber (16C) of an arm cylinder (16) when the contraction of the boom cylinder (15) is instructed by a boom operation device (22A) and the expansion of the arm cylinder (16) is instructed by an arm operation device (21B). The connection switching device (45) connects the bottom-side oil chamber (15C) of the boom cylinder (15) and a rod-side oil chamber (16D) of the arm cylinder (16) when the contraction of the boom cylinder (15) is instructed by the boom operation device (22A) and the expansion of the arm cylinder (16) is instructed by the arm operation device (21B).
Inventors:
SUZUKI KAZUYOSHI (JP)
Application Number:
PCT/JP2020/000912
Publication Date:
September 17, 2020
Filing Date:
January 14, 2020
Export Citation:
Assignee:
HITACHI CONSTRUCTION MACH CO (JP)
International Classes:
E02F9/20; E02F9/22; F15B21/14
Foreign References:
| JP2017106227A | 2017-06-15 | |||
| JP2015048857A | 2015-03-16 | |||
| JP2015048858A | 2015-03-16 | |||
| JP2011179541A | 2011-09-15 | |||
| JP4213473B2 | 2009-01-21 |
Other References:
See also references of EP 3940152A4
Attorney, Agent or Firm:
HIROWA PATENT FIRM (JP)
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