摘要 |
Values of a current and a voltage from a heating power supply device that supplies a current to a wire electrode and that heats the wire electrode are measured, a load resistance value is calculated by dividing the voltage value by the current value, a resistance increment of the wire electrode is calculated from an increased amount in the load resistance value with reference to the load resistance value and an estimated resistance value, a temperature rise value of the wire electrode is estimated based on a specific resistance of the wire electrode and a temperature coefficient of the specific resistance, and a state of carrying a current to the wire electrode is controlled based on the temperature rise value. |