IGNITER PLUG

PURPOSE:To stably perform an ignition even at a high rate of air speed by disposing a protective cover having a plurality of air holes around the ignition source in parallel with the air flowing direction so as to reduce the influence of the air speed on the ignition performance. CONSTITUTION:Since the air pressure in the protective tube 2 becomes lower that the outside air pressure in accordance with the principle of Pitot tube, the air enters from holes 3 drilled in the side of the protective tube 2. On account of the pressure loss when the air passes through the holes 3, the speed of air passing through the protective tube 2 becomes less than 1/2 of that which passes outside the igniter plug. Further, since the fuel particles injected near to the igniter plug are carried away with the incoming air through the holes 3, the ignition at the igniter plug becomes easier. The holes 3 in the side of the protective tube 2 will have the same effect if they are drilled at an angle. The protective tube 2, moreover, prevents the heat generator 1 from being damaged.