Patent ID: 9592576
Date: 2017-03-14
CPC Classifications: B21D,B23P,F28F,Y10T

Claim:
1. A heat transfer tube expansion apparatus comprising: a heat transfer tube fixing apparatus which has grasping sections which grasp one axial direction end sections of a plurality of heat transfer tubes in a state in which the heat transfer tubes are inserted in insertion holes in a plurality of heat transfer fins which are layered with spacing of a predetermined interval and a moving section which switches between a first state of covering surroundings of the grasping sections and a second state of not covering the surroundings of the grasping sections by moving in an axial direction of the heat transfer tubes; and a mandrel apparatus which has mandrels which are inserted from the one axial direction end section side of the heat transfer tubes to an inside of the heat transfer tubes, the moving section being a plate shaped member in which guide holes are formed, the first state being a state in which inner surfaces of the guide holes are moved to positions covering the surroundings of the grasping sections and the second state being a state in which the inner surfaces of the guide holes are moved to positions not covering the surroundings of the grasping sections, the grasping sections fixing the heat transfer tubes so as not to move in the axial direction and the heat transfer fins and the heat transfer tubes are fixed by the heat transfer tubes expanding with the mandrels being inserted inside the heat transfer tubes in a state when the moving section is in the first state, and the guide holes extending from an upper surface to a lower surface of the plate shaped member of the moving section.