Lower nozzle attachment/detachment device

A lower nozzle attaching-detaching apparatus for attaching and detaching a lower nozzle made of a refractory material with respect to a lower plate made of a refractory material and installed in a sliding nozzle device, the lower nozzle attaching-detaching apparatus comprising:

• a holder capable of being attached and detached with respect to a holding metal frame that holds the lower nozzle;
• a robot arm having the holder at a tip thereof;
• a force sensor to detect a reaction force in a front/rear direction and a reaction force in a rotational direction, the two reaction forces being received by the holder from the holding metal frame along with a movement of the robot arm;
• and
• a control unit to monitor and control the movement of the robot arm, wherein the control unit operates to perform attaching and detaching of the lower nozzle by controlling the movement of the robot arm while monitoring the two reaction forces detected by the force sensor, and two movement amounts in the front/rear direction and in the rotational direction of the robot arm.