Hydraulically-actuated fuel injector with direct control needle valve

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(11)

EP 1 152 144 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	18.12.2002 Bulletin 2002/51

(43)	Date of publication A2:
	07.11.2001 Bulletin 2001/45

(21)	Application number: 01117613.8

(22)	Date of filing: 12.08.1997

(51)	International Patent Classification (IPC)⁷: F02M 57/02, F02M 47/02, F02M 59/10, F02M 59/46

(84)	Designated Contracting States:
	DE FR GB

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Priority:

30.08.1996 US 707804
13.12.1996 US 768014
28.05.1997 US 864606

(62)	Application number of the earlier application in accordance with Art. 76 EPC:
	97306118.7 / 0826877

(71)	Applicant: CATERPILLAR INC.
	Peoria Illinois 61629-6490 (US)

(72)	Inventors:
	Chen, Shikui K. Peoria, Illinois 61615 (US) Hefler, Gregory W. Chillicothe, Illinois 61523 (US)

(74)	Representative: Brunner, Michael John
	GILL JENNINGS & EVERY, Broadgate House, 7 Eldon Street London EC2M 7LH London EC2M 7LH (GB)

(54)	Hydraulically-actuated fuel injector with direct control needle valve

(57) A hydraulically actuated fuel injector (14') includes an injector body (105) having an actuation fluid inlet (106) and a needle control chamber (118). A hydraulic means within the injector pressurizes fuel in the injector body (105). The hydraulic means includes an actuation fluid control valve (140) having a solenoid (130) and is movable to open and close the actuation fluid inlet (106). A needle valve member (160) includes a closing hydraulic surface (167) exposed to pressure in the needle control chamber (118). A needle control valve (136), which utilizes the same solenoid (130), is mounted in the injector body (105) and movable to open and close the needle control chamber (118) to a source of high pressure fluid (106). The slower response time of the actuation fluid control valve (140) allows for direct control of the fast responding needle valve (160) by a single fast acting two-way solenoid (130).

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