Friction joining device and friction joining method

A friction joining device comprising:

• a first spindle which grips a first workpiece;
• a second spindle which grips a second workpiece so as to face the first workpiece in an axial direction;
• a first drive mechanism which includes a first drive source and is configured to move the first spindle in the axial direction by using a drive force of the first drive source;
• a second drive mechanism which includes a second drive source and is configured to move the second spindle in the axial direction by using a drive force of the second drive source;
• a rotational drive mechanism configured to relatively rotate the first workpiece and the second workpiece around a rotation axis line along the axial direction;
• control means for controlling the first drive mechanism, the second drive mechanism and the rotational drive mechanism so that the first workpiece and the second workpiece are joined by contacting with each other in a state where the first workpiece and the second workpiece are relatively rotated;
• and
• current limiting means for limiting current flowing to the first drive source and the second drive source to predetermined limit values or less, wherein
• in a first friction heating period that is a predetermined period immediately after the first workpiece and the second workpiece come in contact with each other, the current limiting means limits the current that flows to the first drive source and the second drive source to a first limit value or less that is smaller than a second limit value for limiting the current flowing to the first drive source and the second drive source in a second friction heating period after the first friction heating period has elapsed.