Method for producing fiber-reinforced resin bonded body

A method for producing a fiber-reinforced resin bonded body, for heating connection ends of a first composite member and a second composite member and thereafter pressing the connection ends between a lower mold and an upper mold to bond the connection ends, the first composite member and the second composite member each containing a first thermoplastic resin and first discontinuous fibers having a fiber length La,

• the method comprising:
• a heating step, in which the first composite member and the second composite member are placed on the lower mold in such a manner that end surfaces of the connection ends are arranged facing each other at an interval of a first length, the lower mold is heated by a first heater to melt portions of the first composite member and the second composite member in such a manner that the melted portions extend inward from the end surfaces over a second length, and a connecting member containing a second thermoplastic resin and second discontinuous fibers having a fiber length Lb is heated and melted by a second heater;
• a stacking step, in which the melted connecting member is placed so as to bridge a space between the melted connection ends to thereby form a stack;
• a pressing step, in which the lower mold and the upper mold are moved closer to each other to press the stack, whereby the melted portions of the connection ends and the melted connecting member are caused to flow into the space between the end surfaces and are mixed with each other to form a mixture portion;
• and
• a solidifying step, in which the mixture portion is cooled and solidified, whereby the first composite member and the second composite member are bonded by the mixture portion to produce the fiber-reinforced resin bonded body,
• wherein the first length is equal to or more than ½ of the fiber length Lb, and the second length is equal to or more than the fiber length La.