To prevent the breakage by the rotational torque by providing a round part in a part in which a polygonal flange part of an insert member is brought into contact with a molding body main body to eliminate an edge part to mitigate the stress generated in the molding body part abutted on the insert.
An insert member 10 comprising a cylindrical part 11 having a screw hole 14 in its center part and a polygonal flat plate flange part 12 provided on the cylindrical part 11 is integrated with a molding body in an embedded manner in a molding, and a closing member is screwed in the screw hole 14. A holding part 22 to surround and hold a periphery of the flange part 12 is provided on a formed body main part 20, and round parts R1, R2 for mitigating the stress concentration are provided in corner parts 12a, 12b where the flange part is brought into contact with the holding part 22.
NAKANISHI SHINICHI
UDAGAWA KAZUMASA
