MANUFACTURE OF VOICE COIL

PURPOSE:To hold the mechanical strength of a voice coil with making it a real circle by automatically executing various production procedure of the access of a silver thread line to a heat plate, the cutting by an air nipper, the separation of the silver thread line cross-section due to the access of the heat plate of a second motion to a core and the soldering of lead wires and the silver thread line. CONSTITUTION:The silver thread line 3 is held in a position detached from a voice coil bobbing with both ends clamped by clampers 17 and 18 and with the attitude of straddling the dent part 23 of guides between two guides 9 and 9' protruding from the front edge of the heat plate 8. A cutting tool 22 is inserted into the dent part 23 and only the central part of the silver thread line 3 is cut, whereby there is not slit in the bobbin. If the guides 9 and 9', and the clampers 17 and 18 are simultaneously descended and the heat plate 8 is pressed to the bobbin by an air cylinder, the edge part of the cross-section of the silver thread line 3 which have been cut is pressed to the dent curved surface of the heat plate 8 and is heat-welded along the outer periphery of the coil core 2. At that time, the section of the silver thread line 3 is opened and electric connection is eliminated. Thus, the soldering connection of the silver thread line 3 and the lead wires 4 of the voice coil can be executed.