| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve such a problem that, when an insulation film is adhered to the tip of a wire or a base material, short-circuit determination between the wire and the base material requires certain time in retract start control, so that a pressed wire jumps out in a retreat operation and start failure is generated. <P>SOLUTION: An arc start control method is employed, in which a wire is fed forward in the direction approaching the base material, and contact determination is made based on a detected voltage value between the wire and the base material and on a predetermined short-circuit determination voltage value. The wire is fed backward in the direction separating the wire from the base material after contact determination to generate an arc. Beginning of a decrease in the detected voltage value is detected during the forward feeding, and the short-circuit determination voltage value is gradually increased by a predetermined increase component after the detection. The detected voltage value and the short-circuit determination voltage value are compared with each other, and, when the detected voltage value becomes the short-circuit determination voltage value or less, it is determined that the contact is made. Since determination of obtaining an electrical contact is made at an early timing, the press amount of the wire is reduced, so that start failure is prevented. <P>COPYRIGHT: (C)2013,JPO&INPIT |
