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Patent Searching and Data


Title:
HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINES
Document Type and Number:
WIPO Patent Application WO/2014/092222
Kind Code:
A1
Abstract:
Disclosed is a hydraulic circuit for a construction machine, which is capable of increasing the temperature of the hydraulic fluid to the level appropriate for operating equipment even without boarding the seat of the driver before starting work when the driver works during the winter season or the like. The hydraulic circuit for a construction machine according to the present invention, comprises: first and second hydraulic pumps and a pilot pump; a first hydraulic actuator connected to the first hydraulic pump by means of a first center bypass path; a second hydraulic actuator connected to the second hydraulic pump by means of a second center bypass path; an operating lever; a main control valve for controlling the direction of the flow of the hydraulic fluid which is supplied to the first and second hydraulic actuators from the first and second hydraulic pumps, respectively, by an operation of the operating lever; first and second center bypass valves arranged in the downstream of the first and second center bypass paths, respectively, in the main control valve such that the first and second center bypass valves are capable of opening and closing; and a switching valve arranged in the signal path between the pilot pump and the first and second center bypass valves such that the switching valve is capable of opening and closing.

Inventors:
SON YOUNG-JIN (KR)
YUN SEONG-GEUN (KR)
Application Number:
PCT/KR2012/010933
Publication Date:
June 19, 2014
Filing Date:
December 14, 2012
Export Citation:
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Assignee:
VOLVO CONSTR EQUIP AB (SE)
SON YOUNG-JIN (KR)
YUN SEONG-GEUN (KR)
International Classes:
F15B13/043; E02F9/22; F15B13/044; F15B21/0427
Foreign References:
KR20120086288A2012-08-02
KR101161307B12012-07-05
US20020134227A12002-09-26
JP2001165105A2001-06-19
JPH0726590A1995-01-27
Other References:
See also references of EP 2933504A4
Attorney, Agent or Firm:
YOON, Eui-Seoup (KR)
윤의섭 (KR)
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