| 摘要 |
<p>PURPOSE:To renew old pipes without exerting a bad influence on a neighboring pipe adjacent to the old pipes by providing a pilot pipe having an edge at its end and also to the rear of which new pipes are continuously arranged, a crushing body supported in the central part of the pipe and having a diametrically expanded surface, a pilot pipe propulsion device, and an earth-and-sand discharge device. CONSTITUTION:A pilot pipe 1 to which new pipes Y are continuously arranged, a crushing body 2, a pilot pipe propulsion device 3 by which the pilot pipe 1 is pressedly moved forward from the rear, and an earth-and-sand discharge device 4 by which earth and sand taken in the inside of the pilot pipe 1 or the crushed pieces x of old pipes X are discharged to the rear outside of the pilot pipe 1 are provided. The pilot pipe 1 has an inside diameter larger than the maximum diameter part of the old pipes X, and at the end thereof, has an edge 11 of a taper surface 10. The crushing body 2 is supported by supporting arms 20 in the central part inside the pilot pipe 1, and has a diametrically expanded surface 21 expanded toward the rear. As a result, no bad influence is exerted on the embedded piping adjacent to the old pipes.</p> |
