EP 1193400 A3 20031112 - Hydraulic circuit of construction machine
Title (en)
Hydraulic circuit of construction machine
Title (de)
Hydraulikkreislauf für Baumaschinen
Title (fr)
Circuit hydraulique pour engin de construction
Publication
Application
Priority
JP 2000274757 A 20000911
Abstract (en)
[origin: EP1193400A2] To provide a way to prevent sharp decrease in the speed of main body actuators by ensuring a sufficient amount of hydraulic fluid to be fed to the main body actuators even if the pressure in the attachment circuit of a hydraulic shovel approaches the relief pressure. When the pressure in an independent attachment circuit 37, which is adapted to control an attachment of a hydraulic shovel, approaches a given relief pressure in the course of operating the attachment together with other main body actuators, a controller 71 detects the increase of the pressure by means of a pressure sensor 66 and shifts an electromagnetic selector valve 68 to the channel-communicating position so that priority hydraulic fluid branching off from a pressure compensation flow dividing valve 38 to an external channel 67 flows through the electromagnetic selector valve 68 into a tank 39. As a result, the discharge rate of a pump 33 is increased by the amount equivalent to the decrease in the discharge pressure so that a greater amount of hydraulic fluid is fed from the independent attachment circuit 37 into a main circuit 36 of the main body actuators. Therefore, sharp decrease in the speed of the main body actuators is prevented. <IMAGE>
IPC 1-7
IPC 8 full level
E02F 9/22 (2006.01); F15B 11/16 (2006.01); F15B 11/17 (2006.01); F15B 13/06 (2006.01)
CPC (source: EP)
E02F 9/2228 (2013.01); E02F 9/2253 (2013.01); E02F 9/2285 (2013.01); E02F 9/2292 (2013.01); F15B 11/162 (2013.01); F15B 11/17 (2013.01); F15B 2211/20576 (2013.01); F15B 2211/40515 (2013.01); F15B 2211/4053 (2013.01); F15B 2211/426 (2013.01); F15B 2211/428 (2013.01); F15B 2211/45 (2013.01); F15B 2211/455 (2013.01); F15B 2211/50563 (2013.01); F15B 2211/528 (2013.01); F15B 2211/57 (2013.01); F15B 2211/6313 (2013.01); F15B 2211/6355 (2013.01); F15B 2211/6654 (2013.01); F15B 2211/7142 (2013.01); F15B 2211/781 (2013.01)
Citation (search report)
- [DA] PATENT ABSTRACTS OF JAPAN vol. 2000, no. 06 22 September 2000 (2000-09-22)
- [A] PATENT ABSTRACTS OF JAPAN vol. 011, no. 048 (M - 561) 13 February 1987 (1987-02-13)
- [A] PATENT ABSTRACTS OF JAPAN vol. 1997, no. 05 30 May 1997 (1997-05-30)
- [A] PATENT ABSTRACTS OF JAPAN vol. 1998, no. 09 31 July 1998 (1998-07-31)
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
DOCDB simple family (publication)
EP 1193400 A2 20020403; EP 1193400 A3 20031112; EP 1193400 B1 20050202; DE 60108695 D1 20050310; DE 60108695 T2 20060504; JP 2002089511 A 20020327; JP 3511504 B2 20040329
DOCDB simple family (application)
EP 01302602 A 20010321; DE 60108695 T 20010321; JP 2000274757 A 20000911