| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a heater disconnection alarm apparatus and method provided in an extrusion molding apparatus of highly reliable screw constitution not receiving the effect of the fluctuations of primary power supply voltage supplied to a heater and a heater current value by heater temp. SOLUTION: From the heater rated voltage EO, heater actually measured voltage value EWr and heater actually measured current value AWr in the primary power supply of a heater, a corrected current value A is calculated as the heater current value corresponding to the heater rated voltage value EO by an arithmetic unit 3 and various relations of this corrected current value A and heater temp. are preliminarily stored in a memory device 4. Next, an alarm reference value becoming an alarm signal issuing start point is set from each of the relations of the corrected current value A and the heater temp. to be stored in a memory device 4. When relation W<(EWr /EO)×(AWr /A) is formed from the preliminarily stored alarm reference value W and the heater current value AWr and heater voltage value EWr actually measured at a time of the operation monitor of an extrusion molding apparatus and the heater corrected current value A operated by an arithmetic unit 3 and the heater rated voltage value, an alarm signal is issued.</p> |
