| 摘要 |
PURPOSE:To fuse the main body of a wire with certainty even when an insulation-coated wire is used as well as to control the diameter of a ball in a highly precise manner by a method wherein the insulation coating of an insulation-coated wire is removed first by fusing using a control means when the ball is formed, then the insulating coating is removed, and the ball is formed by fusing the wire main body. CONSTITUTION:First, a selective control signal with which a high voltage generating circuit 6 is selected is outputted from a control part 4, and after the control voltage to be used for high voltage is generated from the high voltage generating circuit 6 and the voltage is boosted at a transforming part 8, the high voltage is applied between an insulation-coated wire and a discharge electrode 3 for a relatively short period of time. When high voltage is applied, the insulating coating 2b of an insulating coated wire 2 is fused first and removed. On the other hand, when the generation of the selective control signal for generation of high voltage is finished, the selective control signal for selection of a low voltage generating circuit 7 is generated from the control part 4, a control voltage for low voltage is generated from the low voltage generating circuit 7, the control voltage is boosted at the transforming part 8, and the voltage is applied between the insulation-coated wire 2 and the discharge electrode 3. As a result, the tip part of the wire main body 2a is fused into a ball 2c. |
