TUBE EXPANDER

PROBLEM TO BE SOLVED: To provide a tube expander capable of adjusting the fin pitch in a desired condition in tube expansion. SOLUTION: A tube expander is use for a heat exchanger 2 having a plurality of layered fins 23 each formed with a plurality of holes and a plurality of heat transfer tubes 24 inserted in the holes and penetrating the fins 23 , and the tube expander fixes the fins 23 to the heat transfer tubes 24 by expanding the heat transfer tubes 24 inserted in the holes of the fins 23, and has a plurality of mandrels 4 and a moving member 8. The plurality of mandrels 4 are inserted in the heat transfer tubes 24 from an upper end side of the plurality of heat transfer tubes 24 to expand the heat transfer tubes 24. The moving member 8 is movable in a first direction A3 from the upper end side to the lower end side of the heat transfer tubes 24, and in a second direction A2 from the lower end side to the upper end side of the heat transfer tubes 24, and can support the fins 23. COPYRIGHT: (C)2006,JPO&NCIPI