EP 2677180 A1 20131225 - HYDRAULIC DRIVE DEVICE OF WORKING MACHINE
Title (en)
HYDRAULIC DRIVE DEVICE OF WORKING MACHINE
Title (de)
HYDRAULISCHE ANTRIEBSVORRICHTUNG FÜR EINE ARBEITSMASCHINE
Title (fr)
DISPOSITIF D'ENTRAÎNEMENT HYDRAULIQUE D'ENGIN DE CHANTIER
Publication
Application
Priority
- JP 2011028940 A 20110214
- JP 2012052977 W 20120209
Abstract (en)
To provide a hydraulic drive system for a working machine, which can realize the assurance of good operability in normal operation and precision operation and a reduction in energy loss in the precision operation. A controller (31) is provided with a pump delivery rate control unit (40) and a center bypass valve control unit (50). The pump delivery rate control unit (40) performs control processing to output, to a control terminal of a solenoid-operated proportional reducing valve (21), a control signal to make a displacement of a variable displacement hydraulic pump (10) smaller than a displacement corresponding to normal operation when a working element control device is in a manipulation mode considered to correspond to precision operation. The center bypass valve control unit (50) performs control processing to output, to a control terminal of a proportional solenoid valve (23), a control signal to make a center bypass valve (22) have a relatively large opening amount despite the center bypass valve (22) is in a switched state between a fully open position and a fully closed position when the working element control device is in a manipulation mode considered to correspond to the precision operation and a load pressure on a working element actuator is in a low state.
IPC 8 full level
F15B 11/02 (2006.01); E02F 9/22 (2006.01); F15B 11/00 (2006.01)
CPC (source: EP KR US)
E02F 9/20 (2013.01 - EP); E02F 9/22 (2013.01 - KR); E02F 9/2235 (2013.01 - EP); E02F 9/2282 (2013.01 - EP US); E02F 9/2285 (2013.01 - EP); E02F 9/2296 (2013.01 - EP); F04B 1/12 (2013.01 - EP); F04B 49/002 (2013.01 - EP); F04B 49/08 (2013.01 - EP); F04B 49/12 (2013.01 - EP US); F04B 49/22 (2013.01 - EP); F15B 11/02 (2013.01 - EP KR)
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
DOCDB simple family (publication)
EP 2677180 A1 20131225; EP 2677180 A4 20180214; EP 2677180 B1 20210922; CN 103380303 A 20131030; CN 103380303 B 20151014; JP 2012167735 A 20120906; JP 5481408 B2 20140423; KR 101913309 B1 20181030; KR 20140010066 A 20140123; WO 2012111525 A1 20120823
DOCDB simple family (application)
EP 12747270 A 20120209; CN 201280008795 A 20120209; JP 2011028940 A 20110214; JP 2012052977 W 20120209; KR 20137023845 A 20120209