Title:
HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINE
Document Type and Number:
WIPO Patent Application WO/2017/018557
Kind Code:
A1
Abstract:
Disclosed is a hydraulic circuit for controlling operation oil, which is supplied from a hydraulic pump to a hydraulic cylinder, and operation oil, which is returned from the hydraulic cylinder to an operation oil tank. The present invention provides a hydraulic circuit for a construction machine, characterized by comprising: a hydraulic pump and a pilot pump; a hydraulic cylinder driven by operation oil from the hydraulic pump; an electrically manipulated level; a first control valve installed in a channel between the hydraulic pump and the hydraulic cylinder so as to supply, when switching, operation oil from the hydraulic pump to a first chamber of the hydraulic cylinder or to return operation oil, which is discharged from the first chamber of the hydraulic cylinder, to an operation oil tank; a second control valve installed in a channel between the hydraulic pump and the hydraulic cylinder so as to return, when switching simultaneously with the first control valve, operation oil, which is discharged from a second chamber of the hydraulic cylinder, to the operation oil tank or to supply operation oil from the hydraulic pump to the second chamber of the hydraulic cylinder; and proportional control valves installed in a channel between the pilot pump and the first control valve and in a channel between the pilot pump and the second control valve, respectively, such that, in order to independently control the spool opening area of the first and second control valves, a pilot pressure corresponding to the amount of manipulation of the electronically manipulated level is applied to the first and second control valves, thereby switching the same.
Inventors:
KIM JIN-WOOK (KR)
KANG MIN-HEUK (KR)
KANG MIN-HEUK (KR)
Application Number:
PCT/KR2015/007867
Publication Date:
February 02, 2017
Filing Date:
July 28, 2015
Export Citation:
Assignee:
VOLVO CONSTR EQUIP AB (SE)
KIM JIN-WOOK (KR)
KIM JIN-WOOK (KR)
International Classes:
E02F9/20; E02F9/22; F15B13/02
Foreign References:
| KR100929420B1 | 2009-12-03 | |||
| JP2006112616A | 2006-04-27 | |||
| KR20130133447A | 2013-12-09 | |||
| KR20140078860A | 2014-06-26 | |||
| KR20140050009A | 2014-04-28 |
Attorney, Agent or Firm:
YOON, Eui-Seoup (KR)
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