Patent EP0269289A2 successfully refreshed from Google Patents.
EP0269289A2
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EP
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Diesel unit fuel injector with spill assist injection needle valve closure
Assignee: Diesel Technology Corp
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Filing: 1987-11-04
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Granted: —
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Expires: 2007-11-04
Abstract
Abstract A diesel unit fuel injector includes a pump assembly having an externally actuated pump plunger (4) reciprocable in a bushing (3) which with the pump plunger defines a pump chamber (14), with flow therefrom during an injection cycle portion of the pump stroke being directed to a fuel injection nozzle assembly. The injection nozzle assembly includes a needle type differential area injection valve (91) that is normally biased to a valve closed position by a valve return spring (97) which is positioned in a spring cavity (103) and which is operatively connected to the opposite end of the needle injection valve. Passage means (51,37,102), including orifice passages (100,101), are used to direct spill flow from the pump chamber at the end of an injection cycle to the spring cavity to effect closure of the needle injection valve at a valve closing pressure which is greater than the valve opening pressure so that the pressure of the discharge of fuel at the end of an injection cycle is relatively great whereby to effect increased penetration of the discharged fuel into the associate combustion chamber of a diesel engine.
Inventors
- 👤 Richard F. Teerman
- 👤 Richard S. Knape
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 03:19
CPC Classifications
F; F02; F02M; F02M57/00; F02M57/02; F02M57/022; F02M57/023; F02M59/00; F02M59/20; F02M59/36; F02M59/366; F02M59/44; F02M59/46; F02M59/466; F02M61/00; F02M61/16; F02M61/20; F02M61/205; F02B; F02B3/00; F02B3/06; F02M2200/00; F02M2200/50; F02M2200/502
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
359 words
A unit fuel injector comprising a pump body (1) with an externally actuated pump plunger (4) reciprocable therein to define a pump chamber (14,14ʹ) open at one end in which fuel is pressurized during a pump stroke of the pump plunger, supply/drain means (30,35) operatively connectable at one end to a source of fuel at a predetermined supply pressure, for supplying fuel to the pump chamber, a fuel injection nozzle assembly operatively connected to the pump chamber, the fuel injection nozzle assembly including a spray tip (15) with spray orifices (93) at the free end thereof which are in flow communication with the pump chamber, an injection valve (91) having one end thereof movable to open and close the spray orifices, a spring cavity (103), a valve return spring (97) positioned in the spring cavity and operatively connected to the opposite end of the injection valve to normally bias the injection valve in a direction to close the spray orifices, and spill flow control means (38) operatively connected to the pump chamber to effect spill flow of fuel during a pump stroke of the pump plunger whereby to control the start and end of injection, characterised in that the spill flow control means includes supply/drain passages (51) in flow communication at one end with the pump chamber, and a flow control valve (38) controlling flow between the opposite end of the supply/drain passages and the opposite end of the supply/drain means; the supply/drain means includes orifice passage means (100,101) next adjacent its opposite end; and by a passage (36,102) interconnecting the spring cavity and the supply/drain means upstream of the orifice passage means in terms of the direction of spill flow from the pump chamber out through the orifice passage means for the spill flow of fuel to the spring cavity, the arrangement being such that the injection valve will open when supplied with pressurized fuel at a predetermined valve opening pressure and will close at a higher pressure as a result of the spill cavity pressure in the spring cavity acting with the valve return spring to effect movement of the injection valve to close the spray orifices.
Claim 2
Dependent Claim
359 words
A unit fuel injector comprising a pump body (1) with an externally actuated pump plunger (4) reciprocable therein to define a pump chamber (14,14ʹ) open at one end in which fuel is pressurized during a pump stroke of the pump plunger, supply/drain means (30,35) operatively connectable at one end to a source of fuel at a predetermined supply pressure, for supplying fuel to the pump chamber, a fuel injection nozzle assembly operatively connected to the pump chamber, the fuel injection nozzle assembly including a spray tip (15) with spray orifices (93) at the free end thereof which are in flow communication with the pump chamber, an injection valve (91) having one end thereof movable to open and close the spray orifices, a spring cavity (103), a valve return spring (97) positioned in the spring cavity and operatively connected to the opposite end of the injection valve to normally bias the injection valve in a direction to close the spray orifices, and spill flow control means (38) operatively connected to the pump chamber to effect spill flow of fuel during a pump stroke of the pump plunger whereby to control the start and end of injection, characterised in that the spill flow control means includes supply/drain passages (51) in flow communication at one end with the pump chamber, and a flow control valve (38) controlling flow between the opposite end of the supply/drain passages and the opposite end of the supply/drain means; the supply/drain means includes orifice passage means (100,101) next adjacent its opposite end; and by a passage (36,102) interconnecting the spring cavity and the supply/drain means upstream of the orifice passage means in terms of the direction of spill flow from the pump chamber out through the orifice passage means for the spill flow of fuel to the spring cavity, the arrangement being such that the injection valve will open when supplied with pressurized fuel at a predetermined valve opening pressure and will close at a higher pressure as a result of the spill cavity pressure in the spring cavity acting with the valve return spring to effect movement of the injection valve to close the spray orifices.
Claim 3
Dependent Claim
20 words
A unit fuel injector as claimed in Claim 1, characterised in that the flow control valve (38) is solenoid actuated.
References Cited (Backward Citations)
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