PURPOSE: To improve the construction of a precombustion chamber of a torch ignition type internal combustion engine to inhibit production of noxious components over a wide range of running of the engine from a low load running to a high load running and to improve the fuel cost and the output power thereof.
CONSTITUTION: A torch ignition type internal combustion engine has a main combustion chamber M to which lean mixture is supplied and a precombustion chamber A which is provided with an ignition plug 16 therein and to which rich mixture is supplied. The precombustion chamber A is divided by a partition wall member 4 into first and second precombustion chambers 5, 6 which are communicated to the main combustion chamber M by way of first and second torch nozzles 7, 8 respectively. The first and second precombustion chambers 5, 6 are communicated to each other by means of a slot 9 formed in the partition wall member 4. Assuming that the total cross sectional areas of the first and the second torch nozzles are represented by F1 and F2, respectively, and the total cross sectional area of the slot 9 by F3, their relationships are determined; F1≤F2, F1≥F3.
FUJII ISAO
KOGURE HIROSHI
MATSUOKA SABUROU
