US 7,464,690 B1 · Adaptive engine injection for emissions reduction

Abstract

NOx and soot emissions from internal combustion engines, and in particular compression ignition (diesel) engines, are reduced by varying fuel injection timing, fuel injection pressure, and injected fuel volume between low and greater engine loads. At low loads, fuel is injected during one or more low-pressure injections occurring at low injection pressures between the start of the intake stroke and approximately 40 degrees before top dead center during the compression stroke. At higher loads, similar injections are used early in each combustion cycle, in addition to later injections which preferably occur between about 90 degrees before top dead center during the compression stroke, and about 90 degrees after top dead center during the expansion stroke (and which most preferably begin at or closely adjacent the end of the compression stroke). These later injections have higher injection pressure, and also lower injected fuel volume, than the earlier injections.

Claims28

Dependent claims

a. over a low range of engine loads, injecting fuel during a low load injection occurring at a low injection pressure prior to the end of the compression stroke;
b. over a range of greater engine loads, injecting fuel:
(1) during one or more starting greater load injections occurring between the start of the intake stroke and the end of the compression stroke;
and
(2) during one or more ending greater load injections occurring prior to the end of the expansion stroke, the ending greater load injections each having:
(a) higher injection pressure than the injection pressure of any of the starting greater load injections, and
(b) lower injected fuel volume than the total injected fuel volume of all starting greater load injections.

4 more elements

An injection method for an internal combustion engine wherein an injector injects fuel into a combustion chamber during an engine cycle having intake, compression, expansion, and exhaust strokes, the method including the steps of injecting fuel during multiple injections occurring between the start of the intake stroke and the middle of the expansion stroke, wherein:

a. any two or more injections starting between the start of the intake stroke and the end of the compression stroke provide each injection after the first injection with greater injection pressure than the prior injection;
b. any injections starting between the end of the compression stroke and the middle of the expansion stroke:
(1) each have an injection pressure which is greater than that of any injections starting prior to the end of the compression stroke, and
(2) collectively have an injected fuel volume which is less than the total injected fuel volume of injections starting prior to the end of the compression stroke.

1 more element

a. over a low range of engine loads, injecting fuel during one or more low load injections wherein:
(1) the first low load injection occurs after the start of the intake stroke,
(2) the final low load injection occurs at or prior to 40 degrees before top dead center during the compression stroke, and
(3) each low load injection after the first low load injection has higher injection pressure than the prior low load injection;
b. over a range of greater engine loads, injecting fuel during:
(1) one or more starting greater load injections wherein:
(a) the first starting greater load injection occurs after the start of the intake stroke;
(b) the final starting greater load injection occurs at or prior to 40 degrees before top dead center during the compression stroke;
and
(c) each starting greater load injection after the first starting greater load injection has higher injection pressure than the prior starting greater load injection;
(2) one or more ending greater load injections wherein:
(a) the first ending greater load injection occurs at or after 90 degrees before top dead center during the compression stroke, and
(b) the final ending greater load injection occurs at or prior to 180 degrees after top dead center during the expansion stroke;
(c) each ending greater load injection has higher injection pressure than any of the starting greater load injections;
(d) each ending greater load injection has lower injected fuel volume than the total injected fuel volume of all starting greater load injections;
and
(e) the total injected fuel volume of all ending greater load injections is less than the total injected fuel volume of all starting greater load injections.

14 more elements

Dependencies are inferred from the claim text.

Adaptive engine injection for emissions reduction

Life of this patent

Adaptive engine injection for emissions reduction

Life of this patent

Abstract

Claims28