HYDRAULIC CIRCUIT APPARATUS FOR HYDRAULIC SHOVEL - HITACHI CONSTRUCTION MACHINERY

Title:

HYDRAULIC CIRCUIT APPARATUS FOR HYDRAULIC SHOVEL

Document Type and Number:

WIPO Patent Application WO/2010/116816

Kind Code:

A1

Abstract:

A hydraulic circuit apparatus for a hydraulic shovel having a hydraulic circuit for an attachment is provided with a direction control valve (16), which provides and removes hydraulic fluid to an attachment which connects to the hydraulic circuit for an attachment; a first overload relief valve unit (38), provided on one set of piping in the hydraulic circuit for an attachment; a second overload relief valve unit (39) provided on the other set of piping in the hydraulic circuit for an attachment; a first proportional solenoid valve (40), which adjusts the relief pressure setpoint of the aforementioned first overload relief valve unit (38); and a second proportional solenoid valve (41), which adjusts the relief pressure setpoint of the second proportional relief valve unit (39). As a result, it is possible for hydraulic breakers, crushers, or the like with various characteristics and capacities to be accommodated by the hydraulic circuit for an attachment by means of a simple configuration.

Inventors:

HANAKAWA KAZUYOSHI (JP)
MITSUHASHI MAKOTO (JP)
NAKAMURA TSUYOSHI (JP)

Application Number:

PCT/JP2010/053156

Publication Date:

October 14, 2010

Filing Date:

February 26, 2010

Export Citation:

Click for automatic bibliography generation Help

Assignee:

HITACHI CONSTRUCTION MACHINERY (JP)
HANAKAWA KAZUYOSHI (JP)
MITSUHASHI MAKOTO (JP)
NAKAMURA TSUYOSHI (JP)

International Classes:

E02F9/22; E02F3/36; E02F9/26; F15B11/028; F15B11/08

Foreign References:

JP2008133842A	2008-06-12
JP2002294758A	2002-10-09
JP2004074331A	2004-03-11
JP2004076411A	2004-03-11
JP2004076411A	2004-03-11

Other References: