Torch-ignition internal combustion engine

摘要

A torch-ignition internal combustion engine has a main and pre-combustion chambers communicated with each other through a torch aperture. Electrodes of a spark plug are disposed in the pre-combustion chamber at a point remote from the torch aperture. A fresh charge of a lean air-fuel mixture is supplied through an intake port into the main chamber on an intake stroke and compressed during a compression stroke so that a part of the fresh mixture charge is introduced through the torch aperture into the pre-combustion chamber. A tubular passage is provided and extends in the pre-combustion chamber toward the plug electrodes to guide the mixture part from the torch aperture toward the plug electrodes during the compression stroke for thereby displacing residual combustion gases away therefrom whereby the plug electrodes are scavenged for improved reliable spark-ignition of the mixture therearound to produce an initial combustion flame which propagates into the passage to produce a torch running through the torch aperture into the main chamber for the torch-ignition of the mixture charge therein. The residual combustion gases in the pre-combustion chamber are mixed with a portion of the fresh mixture part introduced into the pre-combustion chamber to form a stratum or strata of combustible gas which is retained in a space or spaces therein remote from the plug electrodes and which is also burnt by the initial combustion flame at a vurning velocity lower than that of the fresh mixture in the passage. The production of the torch lasts by the time the combustion of the stratum or strata of the combustible gas is completed, whereby the duration of the torch is greatly prolonged compared with the prior art with a resultant improved torch-ignition of the mixture in the main chamber.