| 摘要 |
PROBLEM TO BE SOLVED: To further enhance the finish quality of a floor plate surface.SOLUTION: In a truck floor structure in which a floor plate is fastened to a joint material with a countersunk tapping screw which penetrates the floor plate, the countersunk tapping screw 11 has a screw part 12 which is screw-coupled to the joint material, and a head 13 whose surface is flat and which is integrally formed at the screw part 12, a wooden material pressing face 18 formed of a tapered face 18a and a radial face 18b radially extending from an external peripheral edge of the tapered face 18a is formed at a rear surface side of the head 13, an outside protrusion 19 is formed at the surroundings of the radial face 18b over the whole periphery of the radial face 18b, a plurality of inside protrusions 20 are formed at the tapered face 18a along the circumferential direction at prescribed intervals, and a part of the floor plate which is outwardly expanded by the tapered face 18a is moved in the rotating direction by the inside protrusions 20 and collected to the inside of the outside protrusion 19. |
