EP 1319763 A1 20030618 - Work vehicle with turning upper structure
Title (en)
Work vehicle with turning upper structure
Title (de)
Arbeitsfahrzeug mit drehbarer oberer Struktur
Title (fr)
Véhicule de travail avec structure supérieure tournante
Publication
Application
Priority
JP 2001379672 A 20011213
Abstract (en)
The pump discharge volumetric flow of a variable delivery oil pressure pump (12) is rapidly increased when the vehicle's working machine starts working to improve the machine's action efficiency and is slowly increased when the vehicle starts traveling to diminish the shock thereto. An arrangement is thus provided including a torque control valve (21) for controlling the pump discharge volumetric flow of the pump (12), an electromagnetic proportional pressure reducing valve (23) for applying a pilot pressure to the torque control valve (21) and a controller (28) for controlling the current to energize the solenoid (23a) of the electromagnetic proportional pressure reducing valve (23). When a machine control valve (14) is exclusively operated, the controller (28) rapidly changes the current to the solenoid (23a) of the electromagnetic proportional control valve (23) to rapidly increase the pump discharge volumetric flow. And, when the vehicle traveling morion control valve (13) is operated, it slowly changes the energizing current to slowly increase the pump discharge volumetric flow. <IMAGE>
IPC 1-7
IPC 8 full level
E02F 9/20 (2006.01); E02F 9/22 (2006.01); F15B 11/02 (2006.01); F15B 11/04 (2006.01)
CPC (source: EP KR)
E02F 9/20 (2013.01 - KR); E02F 9/2207 (2013.01 - EP); E02F 9/2235 (2013.01 - EP); E02F 9/2296 (2013.01 - EP); F02D 41/021 (2013.01 - EP)
Citation (search report)
- [A] US 5996341 A 19991207 - TOHJI YUTAKA [JP]
- [A] EP 0644335 A1 19950322 - HITACHI CONSTRUCTION MACHINERY [JP]
- [A] US 6308516 B1 20011030 - KAMADA SEIJI [JP]
- [A] US 6209322 B1 20010403 - YOSHIDA NOBUMI [JP], et al
- [A] EP 0695875 A1 19960207 - HITACHI CONSTRUCTION MACHINERY [JP]
- [A] PATENT ABSTRACTS OF JAPAN vol. 1995, no. 01 28 February 1995 (1995-02-28)
Designated contracting state (EPC)
GB IT
DOCDB simple family (publication)
EP 1319763 A1 20030618; JP 2003184805 A 20030703; JP 3812728 B2 20060823; KR 20030051244 A 20030625
DOCDB simple family (application)
EP 02027168 A 20021205; JP 2001379672 A 20011213; KR 20020077550 A 20021207