Global Patent Index - EP 2362023 A1

EP 2362023 A1 20110831 - Hydraulic drive system for construction machine

Title (en)

Hydraulic drive system for construction machine

Title (de)

Hydraulikantriebssystem für Baumaschinen

Title (fr)

Système de commande hydraulique pour machine de construction

Publication

EP 2362023 A1 20110831 (EN)

Application

EP 11151508 A 20110120

Priority

JP 2010042676 A 20100226

Abstract (en)

A manually operated directional control valve 39 is interposed between attachment-drive lines 37a and 37b to establish connection between an attachment-drive actuator 22 and an attachment-drive control valve 33. The directional control valve 39 is switched to any one of switching positions X, Y, and Z, the first switching position X allowing an actuator port A and a valve port B to communicate with each other and to block a line port C and a tank port D, the switching position Y allowing the actuator port A and the tank port D to communicate with each other and to block the valve port B and the line port C, and the switching position Z allowing the line port C and the tank port D to communicate with each other and to block the actuator port A and the valve port B. Thus, depressurizing work for the attachment-drive lines can be done with a hydraulic circuit having a simple, compact structure.

IPC 8 full level

E02F 3/36 (2006.01); B66C 13/12 (2006.01); E02F 9/22 (2006.01); F15B 21/04 (2006.01)

CPC (source: EP)

E02F 3/3654 (2013.01); E02F 9/2267 (2013.01); E02F 9/2271 (2013.01); F15B 20/005 (2013.01); F15B 2211/3116 (2013.01)

Citation (applicant)

JP H0637087 B2 19940518

Citation (search report)

Designated contracting state (EPC)

AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

Designated extension state (EPC)

BA ME

DOCDB simple family (publication)

EP 2362023 A1 20110831; JP 2011179191 A 20110915

DOCDB simple family (application)

EP 11151508 A 20110120; JP 2010042676 A 20100226