| 摘要 |
<p>The invention provides a necking detecting and controlling method for melted-electrode arc welding. In the necking detecting and controlling method that detects molten-drop necking and thus dramatically reduces welding current, a welding state is inhibited from becoming unstable during a time from a necking detection to reoccurrence of arcs. If molten-drop necking is deected, the welding current (Iw) is reduced until a low-level current value (I1). When a passing time from a necking detection time point reaches a reference time before the reoccurrence of arc, the welding current (Iw) is increased until a high-level current value (Ih). If arc reoccurs, then the welding current (Iw) is changed to an initial arc current value (Iai). Furthermore, the initial arc current value (Iai) is enabled to changed according to a value relative to a heat input amount to a solder wire in a compensation period (Th). As a result, an arc length after the reoccurrence of the arc is appropricated, so that the welding state is stabilized.</p> |
