HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINERY

Title:

HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINERY

Document Type and Number:

WIPO Patent Application WO/2013/176298

Kind Code:

A1

Abstract:

Disclosed is a hydraulic system for performing land preparation works by means of a simultaneous boom-up and arm-in operation. The hydraulic system according to the present invention includes: an arm cylinder and a boom cylinder that are connected to first and second hydraulic pumps, respectively; a first boom control valve that is disposed in the discharge flow path of the second hydraulic pump; a second boom control valve that is disposed in the discharge flow path of the first hydraulic pump and causes the working fluid of the first hydraulic pump to converge with the working fluid which is supplied from the second hydraulic pump to the boom cylinder; a first arm control valve that is disposed in the discharge flow path of the first hydraulic pump; a second arm control valve that is disposed in the discharge flow path of the second hydraulic pump and causes the working fluid of the second hydraulic pump to converge with the working fluid which is supplied from the first hydraulic pump to the arm cylinder; a recycle valve that is disposed in the flow path between the working fluid inlet port of the first arm control valve and a hydraulic tank; and a second boom control valve spool having a parallel pressure section in which the boom-up pilot pressure does not increase with respect to the boom-up strokes during the simultaneous boom-up and arm-in operation.

Inventors:

JEON MAN-SEUK (KR)

Application Number:

PCT/KR2012/003992

Publication Date:

November 28, 2013

Filing Date:

May 21, 2012

Export Citation:

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Assignee:

VOLVO CONSTR EQUIP AB (SE)
JEON MAN-SEUK (KR)

International Classes:

F15B13/043; E02F9/22; F15B13/02

Foreign References:

KR20110075066A	2011-07-06
KR20100134827A	2010-12-24
JPH1113091A	1999-01-19
US5890303A	1999-04-06

Other References: