Multi-cylinder internal combustion engine and method of operation thereof
AssigneeNissan Motor Co., Ltd.
InventorYoshitaka Hata
Life of this patent
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Abstract
At high and low engine speed ranges cylinders are separately fed with rich and lean mixtures. During medium engine speed the rich mixture is leaned but still remains richer than the stoichiometric mixture.
Claims13
A method of operation of a multi-cylinder internal combustion engine having a first group of cylinders consisting of at least half the total number of cylinders and a second group of cylinders consisting of the remaining cylinders, the engine being followed by an afterburner for burning exhaust gases from all the cylinders, comprising:
- feeding said first group of cylinders with a first air-fuel mixture richer than stoichiometric;
- feeding said second group of cylinders with a second air-fuel mixture leaner than stoichiometric;
- and
- feeding said fist group of cylinders with an air-fuel mixture which is leaner than said first air-fuel mixture and richer than stoichiometric only when the engine is operated at medium engine speed range.
A multi-cylinder internal combustion engine which has a first group of cylinders consisting of at least half the total number of cylinders and a second group of cylinders consisting of the remaining cylinders, the engine being followed by an afterburner for burning exhaust gases from all the cylinders, comprising:
- a first carburetor for feeding said first group of cylinders with a first air-fuel mixture richer than stoichiometric;
- a second carburetor for feeding said second group of cylinders with a secone air-fuel mixture leaner than stoichiometric;
- means for allowing said first carburetor to feed an air-fuel mixture which is leaner than said first air-fuel mixure and richer than stoichiometric only when the engine is operated at medium engine speed range.
Dependencies are inferred from the claim text.