Expansion forming apparatus

An expansion forming apparatus that shapes a metal material with a die, comprising:

• an electrode that comes into contact with the metal material and performs energization heating;
• an electrode mounting unit having an electrode movement actuator that moves the electrode along an extension direction of the metal material during heating;
• and
• an electrode adjustment unit that adjusts a moving direction of the electrode by the electrode mounting unit so as to follow the extension direction of the metal material disposed in the die,
• wherein the metal material has a linear shape parallel to a right-left direction which is curved or bent in a middle and is held such that both right and left end portions are inclined downward,
• the electrode adjustment unit is a substantially rectangular plate-shaped block when viewed in a plan view, and is mounted on and dismounted from an upper surface of a base stage, which is a horizontal plane, by fixing means,
• a plurality of the electrode adjustment units in which inclination angles of upper surfaces are different from each other are provided, and
• inclination angles of the electrode and the electrode mounting unit are collectively changed and regulated by exchanging the electrode adjustment units.