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A device for controlling the combustion process in an internal combustion engine

IP.com Disclosure Number: IPCOM000022243D
Publication Date: 2004-Mar-02
Document File: 2 page(s) / 13K

Publishing Venue

The IP.com Prior Art Database

Abstract

The invention relates to an internal combustion engine of the type where a fuel-air mixture is self-ignited by the compression heat, such as HCCI-engines

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A device for controlling the combustion process in an internal combustion engine

The invention relates to an internal combustion engine of the type where a fuel-air mixture is self-ignited by the compression heat. Such internal combustion engines are usually called HCCI-engines (Homogeneous Charge Compression Ignition). The active control of the compression ratio and thereby the ignition time for such an engine has already been proposed by using an extra piston in the engine cylinder head. However, a drawback in using such a solution is the very limited surface area that is left for making a sufficient exchange of gases in the combustion chamber possible. The extra piston has to protrude into the combustion chamber and the bigger its surface area is, the less it has to protrude into the combustion chamber, which is important in order to be able to keep the ordinary piston stroke.

The problem to be solved is to use an extra piston in a way that will not limit the combustion chamber surface, which is necessary for a good gas exchange in the combustion chamber. This is solved by building together an extra piston and a valve of one of the inlet or outlet ports of the combustion chamber.

Fig. 1 shows a cylinder 1 of such an engine, according to an embodiment of the invention. The cylinder 1 comprises a combustion chamber 2, which downwards is restricted by a piston 3. An inlet valve, in the form of a first integrated piston valve 4, is arranged to control the supply of the fuel-air mixture fed into the combustion chamber 2 via an inlet port 5. An exhaust valve, in the form of a second integrat...