HEATING TEMPERATURE CONTROL METHOD FOR HIGH-FREQUENCY INDUCTION HEATING AND HIGH-FREQUENCY INDUCTION HEATING TEMPERATURE CONTROL DEVICE

摘要

PURPOSE:To eliminate a thermocouple sensor and a timer, and cause induction heating to accurately and quickly take place by keeping an oscillation circuit having a high-frequency induction heating coil in an oscillating condition, and then restraining heating temperature for a heated body on the basis of an oscillation frequency changing with the temperature rise of the body under the oscillating condition of the circuit. CONSTITUTION:High-frequency current is caused to flow to a high-frequency induction heating coil 6 and a catalytic converter 9 is thereby induction heated, when a high-frequency power supply 10 composed of a DC power supply 2 and an inverter 3 is used to actuate an oscillation circuit 4 in a heating temperature control device 1. In this case, the output voltage of the power supply section 10 is supplied to a PLL oscillation circuit 8 and current flowing to the coil 6 is also fed to a circuit 8 via a current circuit 7. Also, a control signal corresponding to the voltage and current is generated in the circuit 8, and supplied to the inverter 3, thereby keeping the circuit 4 in an oscillating condition at all times. Namely, a change in specific magnetic permeability rising with the temperature rise of the converter 9 is followed, and the circuit 4 is always kept in an oscillating condition on the operation of the circuit 8. The supply of power from a current section 19 is interrupted, when the oscillation becomes equal to the predetermined frequency.