| 摘要 |
<p>PURPOSE:To prevent an insulation layer from a crack or the like even at a high heater temperature or upon exposure to a heavy vibration by constituting the insulation layer with the first insulation and second insulation layers. CONSTITUTION:An insulation layer comprises the first insulation layer 301 so formed as to adhere to a metal wire 1 having a 45 to 75% filling rate (sectional area rate of insulation layer) of inorganic insulation particles between adjacent metal wires 1 of a metal wire heater, and the second insulation layer 302 formed on the first insulation layer 301 and having the filling rate of the inorganic insulation particles approximately equal to the case of the first insulation layer 301 or more (45 to 85%). As a result, the inorganic insulation particles of the first insulation layer 301 deposited and formed between the metal wires of a metal wire coil is uniformly distributed, and a defect such as an air gap does not occur. The strength of the insulation layer and the electrical insulation characteristics thereof are improved, and the improved characteristics have an effect on the insulation formation of the second insulation layer 302, thereby forming uniform particle distribution and insulation layer. According to the aforesaid construction, a heater can be so formed as to be almost free from a defect in the whole insulation layer.</p> |
