HYDRAULIC CIRCUIT FOR CONSTRUCTION EQUIPMENT

Title:

HYDRAULIC CIRCUIT FOR CONSTRUCTION EQUIPMENT

Document Type and Number:

WIPO Patent Application WO/2012/030003

Kind Code:

A1

Abstract:

Disclosed is a hydraulic circuit that supplements and uses a hydraulic fluid of a hydraulic pump for a cooling fan and a hydraulic fluid of a main hydraulic pump as a hydraulic power unit of RCV to supply a signal pressure to a control valve controlling the drive of a hydraulic actuator. The hydraulic circuit for a construction equipment of the present invention comprises: a first hydraulic pump, a second hydraulic pump, and a third hydraulic pump; a first control valve placed on a fluid channel of the first hydraulic pump; a second control valve placed on a fluid channel of the second hydraulic pump; a hydraulic motor connected to the third hydraulic pump; a cooling fan connected to the hydraulic motor; a first shuttle valve having an input unit connected to the first hydraulic pump and the third hydraulic pump; a second shuttle valve having an input unit connected to the second hydraulic pump and the third hydraulic pump; and a pilot pressure generating device which is placed on a pilot fluid channel connected to each of the output units of the first shuttle valve and the second shuttle valve, and supplies as a pilot signal pressure a hydraulic fluid having a relatively high pressure from the first, second, and third hydraulic pumps to the first and second control valves at the time of a change-over.

Inventors:

SON YOUNG-JIN (KR)
OK JAE-WHAN (KR)

Application Number:

PCT/KR2010/005968

Publication Date:

March 08, 2012

Filing Date:

September 02, 2010

Export Citation:

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Assignee:

VOLVO CONSTR EQUIP AB (SE)
SON YOUNG-JIN (KR)
OK JAE-WHAN (KR)

International Classes:

E02F9/22; F15B13/043; F15B13/02; F15B20/00; F15B21/08; F16K17/04

Foreign References:

JP2002188177A	2002-07-05
JP2008031752A	2008-02-14
KR20090068823A	2009-06-29
JPH11218104A	1999-08-10
JPH11132154A	1999-05-18
KR100640538B1	2006-10-30

Other References: