| 摘要 |
PROBLEM TO BE SOLVED: To precisely control a temperature of respective parts by interposing/ inserting a heat insulating plate between mutually adjacent heating zones of plural heating zones respectively provided with heating wires, a temperature sensor and a temperature controller for adjusting a temperature by information from the temperature sensor. SOLUTION: For example, a heat insulating plate 7 such as heat resistant ceramic fiber is protrusively arranged on upper/lower wall inside surfaces in a furnace in respective boundaries of zones A, B, C in a heating zone 3 in a heating furnace. The respective zones are hardly influenced by radiation heat since the radiation heat of the adjacent zones is shielded and reduced by the heat insulating plate 7 so that a temperature can be accurately adjusted by a temperature controller. The total number of heating wires 4 in the respective zones is desirably set to 2 in the zones A, C and 4 in the zone B to be respectively connected in series to impress the same voltage. A calorific value of the respective heating wires 4 of the zone B is reduced more than that of the other zones so that a temperature rising speed of the respective other zones can be brought near to each other.
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