| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize a compact internal pushing device which can be manufactured as a structure needing neither backing ring nor cushioning material and capable of responding to propulsion work of a short pushing pipe. <P>SOLUTION: A T-shaped internal pushing pipe has an outer diameter slightly smaller than the diameter of a junction collar and is formed such that the length in the pipe axis direction is equal to the sum of the length and the stroke of a hydraulic jack. A cylindrical part, in which a plurality of storage parts for the hydraulic jack are formed, is formed inside the internal pushing pipe, and a rib structure having ribs radially erected on the inner circumference is formed on the side of a barrier wall. The hydraulic jack directs a tip of telescopic motion direction toward a propulsion direction and a jack body is fixed to the storage part by means of a mounting metal fitting. An S-shaped internal pushing pipe is provided with a water cut-off rubber on the outer peripheral surface and has a junction part with ribs radially erected at equal intervals on the inner circumference. A steel collar having a diameter slightly larger than the outer diameter of the cylindrical part is integrated with the S-shaped internal pushing pipe via a rear side barrier wall of the junction part, and a cylindrical part of the T-shaped internal pushing pipe is inserted into the steel collar of the S-shaped internal pushing pipe via a rubber ring for the T-shaped internal pushing pipe. <P>COPYRIGHT: (C)2012,JPO&INPIT |
