| 摘要 |
PURPOSE:To enable the inlet pipe to be press-fixed tightly to the heat exchanger tank by a method wherein a positive electrode of die structure is fitted to one end of the inlet pipe, a negative electrode of punch structure is fitted to the other end of the pipe, an electric current is supplied through the electrodes at the same time, an electrode which is movable is moved toward the other electrode so that an annular bead is formed about the pipe and the bead is crushed. CONSTITUTION:A barring hole 1 is drilled in the wall 3 of the heat exchanger tank UT and a projection 4 for preventing the slipping out of a hose is formed on the outer surface of the inlet pipe P. Then the tank UT is fitted about the die-structured positive electrode 5 of a projection welder, the pipe P is inserted into the hole 1 and an insert hole 6 in the positive electrode 5 and the split type punch-structured negative electrode 7 is set on the pipe P. With the above structure, when the electrodes 5 and 7 are energized and the electrode 7 is moved toward the electrode 5, the resultant heat concentrates on the exposed portion 9 of the pipe P so that the bead 2 formed due to a buckling phenomenon is then crushed by the movement of the electrode 7 to form itself a flange. Accordingly the pipe P is fixed firmly to the tank and the wall of the tank is also strengthened. |
