Resistance spot welding apparatus and method for manufacturing a welded structure

A resistance spot welding apparatus comprising:

• a first rod-shaped electrode body,
• a second rod-shaped electrode body,
• a first ring-shaped member,
• a second ring-shaped member,
• a first compression coil spring,
• a second compression coil spring,
• a first holder, and
• a second holder, wherein
• the first rod-shaped electrode body and the second rod-shaped electrode body are arranged facing each other,
• the first ring-shaped member and the second ring-shaped member are arranged facing each other,
• the first holder is fixed to the first rod-shaped electrode body on a side opposite to the second rod-shaped electrode body and the first holder is mounted on a spot welding gun,
• the second holder is fixed to the second rod-shaped electrode body on a side opposite to the first rod-shaped electrode body and the second holder is mounted on a spot welding gun,
• the first rod-shaped electrode body is inserted into a through hole of the first ring-shaped member,
• the first compression coil spring is connected between the first ring-shaped member on a side opposite to the second rod-shaped electrode body and the first holder,
• the first rod-shaped electrode body and the first ring-shaped member are not electrically connected each other,
• the second rod-shaped electrode body is inserted into a through hole of the second ring-shaped member,
• the second compression coil spring is connected between the second ring-shaped member on a side opposite to the first rod-shaped electrode body and the second holder, and
• the second rod-shaped electrode body and the second ring-shaped member are not electrically connected each other.