Patent ID: 7291302

Claim:
A manufacturing method for a synthetic resin hollow molded body, comprising: a first injection molding process in which a first split assembly member, a second split assembly member and a third split assembly member are molded by a first injection between a first die and a second die, a positioning process in which phases of the first split assembly member, the second split assembly member, and the third split assembly member are made different in a die opening/closing direction while the first die and the second die are open, and then first split assembly member, the second split assembly member, and the third split assembly member are made to face one another in the die opening/closing direction; and a second injection molding process in which each of the contact portions of the first split assembly member, the second split assembly member, and the third split assembly member is made to contact a corresponding contact portion and each of the contact portions is joined with the corresponding contact portion by a second injection between the first die and the second die; wherein in the positioning process, the second split assembly member is moved in the die opening/closing direction such that the phases of the first split assembly member, the second split assembly member, and the third split assembly member are made different in the die opening/closing direction, the third split assembly member is rotated around the shaft center in the die opening/closing direction such that the second split assembly member, and the third split assembly member face each other in the die opening/closing direction, and the second split assembly member, and the third split assembly member are slid in a direction perpendicular to the die opening/closing direction, whereby the first split assembly member, the second split assembly member, and the third split assembly member face one another in the die opening/closing direction.