US 7,685,990 B2Granted

Dual mode combustion apparatus and method

AssigneeDelphi Technologies, Inc.

InventorPhilip J. G. Dingle

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Abstract

A fuel injection apparatus for a fuel injector nozzle includes a moveable valve needle slideably located within a nozzle body, the nozzle body having an internal surface defining a valve seat between a fuel supply path and fuel outlets. The valve needle includes an obturator piston that is engagable with an axial fuel outlet and a two-stage lift mechanism for enabling lift of the valve needle. In a first stage lifted position of the valve needle, the valve face is spaced apart from the valve seat, and the obturator piston is positioned such that a fuel flow passage is opened between the obturator piston and the axial fuel outlet. In a second stage lifted position, the valve face is spaced further apart from the valve seat and the obturator piston is positioned such that the fuel flow passage between the obturator piston and the axial fuel outlet is substantially closed.

Claims23

Dependent claims

A fuel injection apparatus for a fuel injector nozzle, the apparatus comprising:

a nozzle body and a moveable valve needle slideably located within the nozzle body;
wherein the nozzle body has a plurality of radial fuel outlets, at least one axial fuel outlet, an external surface, and an internal surface defining a valve seat positioned between a fuel supply path and the fuel outlets;
wherein the valve needle comprises:
a valve face that engages with the valve seat when the valve needle is in a seated position such that a fluid-tight seal is formed between the fuel supply path and the fuel outlets,
an obturator piston that is engageable with the at least one axial fuel outlet,
a spray shaping region having, at least in part, a concave, necked profile located between the valve seat and the obturator piston, wherein the profile of the valve needle transitions smoothly between the valve seat, spray shaping region, and obturator piston;
and
a two-stage lift mechanism for enabling lift of the valve needle;
wherein each of the fuel outlets passes through the nozzle body from the internal surface to the external surface;
wherein, in a first stage lifted position of the valve needle, the valve face is spaced apart from the valve seat, and the obturator piston is positioned such that a fuel flow passage is opened between the obturator piston and the axial fuel outlet;
and
wherein, in a second stage lifted position, the valve face is spaced further apart from the valve seat and the obturator piston is positioned such that the fuel flow passage between the obturator piston and the axial fuel outlet is substantially closed;
wherein, in use, the profile of the spray shaping region encourages fuel passing the surface of the valve needle to be attached to it.

10 more elements

An internal combustion engine comprising a fuel injector, a fuel supply means, and a reciprocating piston, the fuel injector comprising a nozzle body provided with a plurality of radial fuel outlets and an axial fuel outlet, a moveable valve needle which allows or prevents fuel flow through the radial and axial fuel outlets, and a lift mechanism which controls movement of the valve needle under the influence of pressurised fuel provided by the fuel supply means, the reciprocating piston comprising a combustion chamber having a secondary combustion cavity provided with an inlet, wherein the inlet is arranged relative to the axial fuel outlet of the fuel injector such that, in use, when the reciprocating piston is at or near a top dead centre position, fuel passing through the axial fuel outlet is directed into the secondary combustion cavity, characterised in that, when the fuel supply means supplies fuel to the injector at a first pressure the lift mechanism raises the valve needle to a first lifted position, wherein a first portion of the injected fuel is injected through the axial fuel outlet and in that when the fuel supply means supplies fuel to the injector at a second pressure the lift mechanism raises the valve needle to a second lifted position wherein a second portion of the injected fuel is injected through the radial fuel outlets.

A method of operating a dual combustion mode fuel injection system comprising the steps of:

supplying fuel to a fuel injector at a first, relatively low, pressure such that a first injection event occurs in which a majority of the fuel is injected through a nozzle outlet path for a premixed combustion mode and a minority of the fuel is injected through a nozzle outlet path for a diffusion combustion mode;
supplying fuel to the fuel injector at a second, relatively high, pressure such that a second injection event occurs in which a majority of the fuel is injected through a nozzle outlet path for a diffusion combustion mode and a minority of the fuel is injected through a nozzle outlet path for a premixed combustion mode;
wherein in the second injection event the fuel injected through the nozzle path for a diffusion combustion mode is burned in a primary combustion event and the fuel injected through the nozzle path for a premixed combustion mode is burned in a secondary combustion event;
and wherein the combustion gases from the secondary combustion event re-energise the primary combustion event.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 11/998,465Filed 29 Nov 2007
Published: US 2009/0139487 A14 Jun 2009
Granted: 30 Mar 2010
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

F02M 61/06
Having valves , e.g. having a plurality of valves in series: the valves being furnished at seated ends with pintle or plug shaped extensions
F02M 61/1813
Characterised by the arrangement of discharge orifices, e.g. orientation or size: discharge orifices having different orientations with respect to…
F02M 61/182
Characterised by the arrangement of discharge orifices, e.g. orientation or size: discharge orifices being situated in different transversal…
F02M 61/1866
Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for: valve seats or member ends having…