MANUFACTURING METHOD FOR A COMPONENT INCLUDING A THERMOPLASTIC RESIN MATERIAL, AND MANUFACTURING DEVICE FOR A COMPONENT INCLUDING A THERMOPLASTIC RESIN MATERIAL

Bumper reinforcement (20) is manufactured by: a first process of respectively setting a first molded article (22) and a second molded article (24) in a first mold (30) and a second mold (32); a second process of setting a third molded article (25, formed employing a thermoplastic resin material or a metal material, in a third mold (34 such that the third molded article (25) is disposed between the first molded article (22) and the second molded article (24); and a third process of vibrating the third mold (34) such that by moving the third mold relative to the first mold (30) and the second mold, sliding contact is caused and vibration welding is performed between the first molded article (22) and the third molded article (25), and sliding contact is caused and vibration welding is performed between the second molded article (24) and the third molded article (25).