Carriage for pipe machining

A carriage for pipe machining, comprising:

• a traveling unit equipped with a machining tool for machining a pipe, wherein the traveling unit is configured to travel along an outer circumferential surface of the pipe;
• the traveling unit comprising:
• a body;
• and
• a front wheel and a rear wheel that are mounted to a lower portion of the body to roll while in contact with the outer circumferential surface of the pipe;
• and
• a roller chain coupled to the traveling unit to wrap around the outer circumferential surface of the pipe, wherein the roller chain is configured to guide the traveling unit to travel along the outer circumferential surface of the pipe,
• wherein the roller chain is configured to:
• couple both ends of the roller chain to the traveling unit;
• couple a plurality of unit roller chains to each other in succession so as to extend in a longitudinal direction of the roller chain;
• and
• enable a roller mounted in each of the unit roller chains to rotate on the outer circumferential surface of the pipe, and
• wherein the traveling unit is adapted such that a distance between the front wheel and the rear wheel of the traveling unit is adjusted according to a diameter of the pipe.