1. Field of the Invention
This invention relates to internal combustion engines.
2. Description of the Prior Art
Internal combustion engines have been proposed having stratified charging in which air only is admitted through the inlet valve and fuel is injected directly into the combustion chamber and ignited by a plug located adjacent to the injection nozzle where the air/fuel mixture is rich and ignitable. The combustion thus initiated should burn up the remainder of the fuel in the cylinder which is mixed with the air in the form of a layer of very lean mixture superimposed in a layer of air over the piston. Engine speed is controlled by varying the amount of petrol injected. Such engines have not in practice proved satisfactory because of difficulties in controlling engine speed by controlling the fuel supply only. A modified type of stratified engine has also be proposed having rich mixture ante chambers fed through separate inlet valves with inlet throttling of a carburetor supplying a very weak mixture through a conventional inlet valve. Such an engine can be controlled satisfactorily but has a high cost due to the additional equipment required.
It is an object therefor of the applicant's invention to provide an internal combustion engine in which improved ignition of the initial mixture is achieved without requiring additional equipment such as an additional carburettor and separate inlet valve.