Resistance welding machine and method of controlling resistance welding machine

A resistance welding machine comprising:

• a first electrode and a second electrode between which a base material to be welded is inserted;
• a pressure application device configured to apply pressure between the first and second electrodes, thereby applying pressure to the base material inserted between the first and second electrodes:
• a power supply unit configured to provide electrical energy between the first and second electrodes;
• an infrared radiation thermometer configured to measure temperature of the first electrode;
• and
• a controller configured to control the power supply unit, wherein
• when the base material is welded in accordance with a first set of energization conditions preset as energization conditions including a current value and an energization time flowing between the first and second electrodes when welding the base material, and a temperature limit of the first electrode during the energization time,
• the controller is configured to control the power supply unit to apply current between the first and second electrodes at the current value for the energization time, in a case where the temperature of the first electrode measured by the infrared radiation thermometer has not reached the temperature limit within the energization time, and
• the controller is configured to control the power supply unit to shift to welding in accordance with a second set of energization conditions when the second set of energization conditions are set to follow the first set of energization conditions, and to control the power supply unit to stop energizing when the second set of energization conditions are not set, at a point when the temperature of the first electrode has reached the temperature limit, in a case where the temperature of the first electrode measured by the infrared radiation thermometer has reached the temperature limit within the energization time.