| 摘要 |
PURPOSE:To make it possible to simply and uniformly polish a specific part such as, for example, a back bead on the internal surface of a pipe, by filling a magnetic fluid containing therein magnetic particles and abrasive particles in the pipe, and by applying magnetic force which rotates or reciprocates at a high speed, from the outer peripheral surface of the pipe. CONSTITUTION:During polishing a connecting pipe A0 such as, for example, a stainless pipe, a fluid C containing a magnetic fluid and abrasive particles is filled into the pipe, and two semicircular magnets 4a, 4b each having both poles are arranged around the outer periphery of the pipe along the circumferential direction of the pipe so that both magnets 4a, 4b are opposed to each other, and therefore, magnetic force lines P are generated. Further, the pair of magnets 4a, 4b are rotated at a high speed along the outer periphery of the pipe or reciprocated in the longitudinal direction of the pipe by a suitable means, and therefore, the fluid C in the connecting pipe A0 is moved to rub the convex surface of a back bead 3, etc. for polishing the same. Thus, if the magnetic poles are set at suitable positions, it is possible to simply and uniformly polish the back bead, etc. the bead on each welded section A1 are polished one by one, and then the polishing fluid C is returned into a fluid tank 4. |
