| 摘要 |
PURPOSE:To improve the durability of the titled device by a method wherein a heater is formed in double helical shape by winding a pair of thin wires which extended forward with the proper insulating interval from the base bottom where said thin wire of a heat generating coil is folded. CONSTITUTION:The heater 1 of a glow plug is formed in double helical shape by winding a pair of heat generating wires which extended forward with the proper insulating interval from a base bottom 11a where a heat generating coil 11 is folded. The positive and negative pole side terminals T1, T2 are both extended from each forward end of said heat generating coil. Thereby, the straight parts for taking out the terminals from said heat generating coil can be provided at each low temperature part of the heater. Thus, the disadvantage of said heater is solved without decreasing of mass production efficiency. Further, because of the extreme minimanizing of the varation in thermal expansion between a sintering material 12 of surrounding silicone nitride, the durability of the heater can be improved without posibility of breaking of wire, even when the pre-heating speed is more increased by flowing of larger amount of electrical current in the heater. |
