Molding method for fiber-reinforced plastic structure, and vehicle wheel

A molding method for a fiber-reinforced plastic structure having a plurality of hollows, comprising:

• forming a plurality of cores by filling each of a plurality of bags made of a flexible material with a grain group;
• interposing prepreg laminates, each of which includes one or more prepregs, between adjacent cores of the plurality of cores;
• disposing the plurality of cores in contact with the prepreg laminates to make a preform, and setting and pressing the preform in a cavity of a molding die;
• pressing a portion of an outer circumferential surface of at least one core of the plurality of cores with pressing means that moves into the cavity of the molding die;
• deforming the at least one core by increasing an internal pressure of the at least one core;
• increasing cohesion of the prepreg laminates to the molding die and the plurality of cores disposed in the cavity of the molding die by the deformation of the plurality of cores due to the pressing;
• curing a resin in a state where the prepregs that accommodate the plurality of cores are pressurized in the cavity of the molding die;
• and
• removing the grain group filling the plurality of cores from the bags.