Retrofit propulsion device of existing buried pipe

摘要

PROBLEM TO BE SOLVED: To install a propulsion unit with a sufficient propulsion stroke by using an existing manhole and further install a drive unit with high output by using a manhole on the arrival side to enable efficient propulsion and earth removal.SOLUTION: The reconstruction propulsion unit includes: a propulsion unit that is arranged in a starting side manhole and has a propulsion cylinder for generating propulsion force for propelling a renewal pipe and a guiding pipe; a rotation drive unit that is arranged in an arrival side manhole and outputs torque for rotating an excavation head and a screw; and a division type transmission rod that interconnects the rotation drive unit and the excavation head through the inside of an underground pipe to transmit the torque output by the rotation drive unit to the excavation head. The propulsion unit includes a propulsion stroke doubling mechanism that enables continuous propulsion strokes of a first stage and a second stage by a full stroke of the propulsion cylinder.