| 摘要 |
<p>PURPOSE: To specify a pitch of a thread ridge in an external thread part and in an internal thread part with respect to a tread overlap in both thread part so as to suppress deterioration in joining strength in a connecting part in screw connecting in which a fiber reinforced plastic pipes are connected together via a fiber reinforced plastic joint. CONSTITUTION: A FRP pipe 1 is molded by winding fiber roving immersed in plastic on a core bar, while the first stepped parts 3 are formed on both end outer circumferential faces 2 in the FRP pipe 1, and in the stepped part 3, an external thread part 4 is formed by means of cutting and the like. The second stepped parts 5 are arranged in the pipe end parts by means of cutting and like. When the FRP pipes 1, 1 are joined together, a FRP joint 6, in which an internal thread part 8, a circular recess part 9, and a circular stepped part 10 are formed on an internal circumferential face 7 by means of cutting and the like, is used, and the external thread part 4 and the internal thread part 8 are screwed to each other so as to perform junction. In this process, a pitch in each of the thread parts 4, 8 is set to be 10 times as high as a thread overlap or more, and as a result, excellent joining strength can be obtained.</p> |
