| 摘要 |
PROBLEM TO BE SOLVED: To contrive so that a cleaning gun is not required to be alway held horizontally and pressed when the fine pipe is cleaned by a method wherein an expansion rubber is applied to cover a nozzle head, the outer periphery of an extremely end of the expansion rubber is expanded with hydraulic pressure and closely contacted with and held against the inner wall surface of the fine pipe. SOLUTION: Small holes 21 are punched on the circumference of a front cylindrical part 20F of a nozzle head N threadably fixed to the extremity end of a nozzle main body 5. Expansion rubber 22 having rubber characteristic covered on the front cylindrical part 20F of the nozzle head N has a cylindrical shape at its front side, its rear side is formed into a frustum of circular cone, and the expansion rubber 22 is supported and prevented from being pulled off by engaging projections 23 spaced apart and projected at a forward or a rearward position of the small holes 21 at the outer circumference of the front cylindrical part 20F. Then, an annular concave groove is formed at the inner circumferential surface of the expansion rubber 22 corresponding to the outer circumferences of the small holes 21, the part in the annular concave groove 24 of the expansion rubber 22 is expanded with pressurized water injected from the small holes 21, resulting in that the extremity end of the nozzle head N is closely contacted and held against the inner circumferential surface of a fine pipe P so as to seal it. |
