HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINERY HAVING FLOATING FUNCTION AND METHOD FOR CONTROLLING FLOATING FUNCTION

Title:

HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINERY HAVING FLOATING FUNCTION AND METHOD FOR CONTROLLING FLOATING FUNCTION

Document Type and Number:

WIPO Patent Application WO/2014/208828

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, is provided with: 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 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.

Inventors:

JOUNG HEA-GYOON (KR)
KIM SUNG-GON (KR)

Application Number:

PCT/KR2013/009788

Publication Date:

December 31, 2014

Filing Date:

October 31, 2013

Export Citation:

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Assignee:

VOLVO CONSTR EQUIP AB (SE)
JOUNG HEA-GYOON (KR)
KIM SUNG-GON (KR)

International Classes:

F15B13/043; E02F9/22; F15B19/00

Foreign References:

US6892535B2	2005-05-17
JP2010084333A	2010-04-15
US6186044B1	2001-02-13
US5890303A	1999-04-06
JPH06128983A	1994-05-10
KR100621977B1	2006-09-13

Other References: