IGNITION DEVICE WITH COMBUSTION FLAME DETECTING FUNCTION

PURPOSE:To provide an ignition device with combustion flame detecting function which saves energy and enables easy prevention of adhesion of carbon, by a method wherein, during running of an engine, a detecting part of glass is normally heated and controlled to temperature at which a combustion prod is difficult to adhere. CONSTITUTION:A heat resistant material 7 consisting of a mixture of silica and alumina is disposed to a hollow part formed between a metallic pipe 4, formed integrally with a cylindrical cover 1, a case 2, and an attaching screw part 3, and an optical fiber 5 for detecting light disposed to the central part of the metallic pipe, and a heater 8 is buried in the heat resistant material. By means of a detecting signal for a combustion flame, a microcomputer outputs a signal, responding to running of an engine, to a temperature set part to heat and control the heater 8 to a temperature of 300-700 deg.C. Namely, after running of an engine, the temperature of the heater 8 is controlled by means of a signal by means of which the running state of an engine is monitored so that the temperature of the detecting part of the fiber 5 for detecting light is maintained at a value at which a combustion prod is difficult to adhere. Since a combustion prod is prevented from adhesion before it is adhered, the combustion product can be prevented from adhesion by means of a small amount of energy.