HIGH FREQUENCY INDUCTION HEATING TYPE CASTING APPARATUS

摘要

PROBLEM TO BE SOLVED: To automatically set an optimum timing of gas pressurization for pushing molten metal into a mold.

SOLUTION: A high frequency induction heating type casting apparatus includes: a parallel resonance circuit 12 constituted of a coil 5 for high frequency heating concentrically disposed on the outer periphery of a crucible 1 for holding metallic material, and a condenser 11 connected in parallel with the coil; a high frequency signal generater 14 for supplying the high frequency signal into the parallel resonance circuit; a detector 18 for detecting the magnitude of the high frequency signal current supplied to the above parallel resonance circuit or detecting the resonance frequency; a comparator 22 for generating a control signal by comparing the magnitude of the signal current or the resonance frequency detected with this detector and changed by the fall and discharge of the molten metal from the crucible toward a sprue of the mold, with the preset reference value; and a timing circuit 24 for generating a signal for starting the gas pressurization for pushing the molten metal into the mold at the optimum timing.

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