Title:
HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINERY HAVING FLOATING FUNCTION AND METHOD FOR CONTROLLING FLOATING FUNCTION
Document Type and Number:
WIPO Patent Application WO/2014/208795
Kind Code:
A1
Abstract:
Disclosed are a hydraulic circuit for using a hydraulic fluid in a hydraulic pump in another hydraulic actuator, during levelling and grading work by means of an excavator, and a method for controlling a floating function. A hydraulic circuit for construction machinery having a floating function, according to the present invention, comprises: two or more hydraulic pumps; a hydraulic cylinder connected to the hydraulic pumps; a boom driving control valve provided on the flow path between the hydraulic pump on one side and the hydraulic cylinder; a boom confluence control valve provided on the flow path between the hydraulic pump on the other side and the hydraulic cylinder; an operating lever; a first sensor for measuring the hydraulic fluid pressure of a large chamber of the hydraulic cylinder; a second sensor for measuring the boom lowering pilot signal pressure applied to one end of the boom driving control valve; a control valve provided on the flow path between the operating lever and the other ends of the boom driving control valve and the boom confluence control valve, wherein the control valve, when switched by means of the application of an electrical signal which corresponds to the pressure detection value of the first and second sensors, switches the boom confluence control valve into a floating state by applying the boom lowering pilot signal pressure to the boom confluence control valve, or supplies the hydraulic fluid in the hydraulic pump on one side to a small chamber of the hydraulic cylinder by means of the switching of the boom driving control valve by applying the boom lowering pilot signal pressure to the boom driving control valve.
Inventors:
JOUNG HEA-GYOON (KR)
KIM SUNG-GON (KR)
KIM SUNG-GON (KR)
Application Number:
PCT/KR2013/005742
Publication Date:
December 31, 2014
Filing Date:
June 28, 2013
Export Citation:
Assignee:
VOLVO CONSTR EQUIP AB (SE)
JOUNG HEA-GYOON (KR)
KIM SUNG-GON (KR)
JOUNG HEA-GYOON (KR)
KIM SUNG-GON (KR)
International Classes:
E02F9/22; F15B13/02
Foreign References:
| KR100621977B1 | 2006-09-13 | |||
| KR20100056087A | 2010-05-27 | |||
| JP2010084332A | 2010-04-15 | |||
| KR200348333Y1 | 2004-07-07 | |||
| JPH10168949A | 1998-06-23 |
Attorney, Agent or Firm:
YOON, Eui-Seoup (KR)
윤의섭 (KR)
윤의섭 (KR)
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