Inner plate mounting structure of boxcar

The invention discloses an inner plate mounting structure of a boxcar. The inner plate mounting structure comprises an undercarriage, a flank, an end wall, a floor and a top plate, the floor comprises unit composite boards paved on the surface of the undercarriage and uniformly distributed along the length direction of the undercarriage of the boxcar, the adjacent unit composite boards are connected or overlapped by mortise and tenon joints, and the unit composite boards are fixedly connected with a small longitudinal beam of the undercarriage via flush bolts. An inner glass fiber reinforced polyurethane composite wallboard is fixedly mounted on the inner side of an outer wallboard. The inner plate mounting structure has the advantages that the glass fiber reinforced polyurethane composite wallboard is used as the floor of the boxcar, the glass fiber reinforced polyurethane composite materials are arranged in the flank, the end wall and the top plate as the structural layers, weatherability and stability in use of the glass fiber reinforced polyurethane composite boards are sufficiently developed, and the inner plate mounting structure has impact resistance, wear resistance, skid resistance, environment friendliness and the like, the polyurethane hard foam plastics are arranged on the inner sides of the structural layers of the flank, the end wall and the top plate, and heat insulation performance is improved.