Patent ID: 7943075

Claim:
A method for producing a fiber-reinforced composite member having a rectangular, flat panel portion and flanges extending from its edges, from prepregs of reinforcing fibers impregnated with a matrix resin, by using a molding die comprising upper and lower dies each having outer dimensions substantially equal to the other and having a cavity, and a plurality of side dies, each cavity of said upper and lower dies having a horizontal portion having aligned first holes, and vertical portions, at least one of which has second holes, each of the first holes of the upper die having a large diameter screw-threaded portion and a small diameter cylindrical-shaped portion, and each of the first holes of the lower die and the second holes having a large diameter portion and a small diameter portion, comprising: (1) forming the molding die by fitting resin-leak preventing plugs complementary in shape to each of the first holes of said upper and lower dies and the second holes to the first holes of said upper and lower dies and the second holes, respectively, stacking the upper die on the lower die so that each of corner projections of the upper die rests directly on a corresponding corner projection of the lower die so that the horizontal portions of cavities of the upper die and the lower die directly face each other, and clamping the side dies, respectively, along each of vertical sides of the stacked upper and lower die so as to cover an entirety of each vertical side of the stacked upper and lower dies including vertical portions of the cavities; (2) placing a laminate of said prepregs in the horizontal portions of the cavities of said upper and lower dies and in the vertical portions of the cavities formed between at least one of the side walls and one of the upper and lower dies; (3) cutting off excess margins of said prepreg laminate along the edges of the cavities; (4) heating said prepreg laminate after closing said upper die, said lower die and said side dies, to cure said matrix resin; (5) detaching the resin-leak-preventing plugs from the first holes of the upper and lower dies and the second holes; and (6) forming connecting holes in the rectangular, flat panel portion and at least one of the flanges of a resultant cured prepreg molding by fixing a jig having holes aligned with the second holes in said vertical portion to at least one side surface of said upper or lower die, inserting a guide plug having a hole into each of the first holes of said upper die and the holes of the jig, said guide plug being complementary in shape to each of said first holes of said upper die and the jig, and inserting a boring tool into the hole of each guide plug in order to produce the fiber-reinforced composite member.