NEW PIPE LEADING DEVICE FOR REPLACING BURIED PIPE WITHOUT OPEN-CUT AND RELAYING

摘要

PURPOSE:To miniaturize a propulsion device by way of reducing propulsion force of the propulsion device by making outer diameter of a guide part almost the same as the inner diameter of a buried pipe, making a broken opened part in a slightly larger diameter than the inner diameter of the previously buried pipe and making an expanded diameter part in the same diameter as the outer diameter of a new pipe. CONSTITUTION:A leading pipe 20 consists of a small diameter head end part 21, a tapered intermediate part 22 and a large diameter rear end part 23, on the small diameter head end part 21, guide rollers 24 are installed radially in a plural number and become a guide part, on the tapered intermediate part 22, breaking opening rollers 25 are radially installed in a plural number and become a broken and opened part, and on the large diameter rear end part 23, diameter expansion rollers 26 are radially installed in a plural number and become an expanded diameter part. Consequently, the previously buried tube 4 is expanded in diameter by the diameter expansion rollers 26 after it is broken and opened by the breaking opening rollers 25, the inner diameter of an diametrically expanded part 4a becomes the same as the outer diameter of a new pipe 6, and as a difference of diameters of the preciously buried pipe 4 and the diameter expanded part 4a, that is, an expanded diameter flap becomes small and pressing force required for diameter expnasion becomes small, it is possible to miniaturize a propulsion device by way of reducing propulsion force.