| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that when a short-circuit failure occurs in an arc welding apparatus having a low internal impedance, an output stop only based on an absolute current threshold is too late to prevent damage of an apparatus due to excessive current flow. <P>SOLUTION: The arc welding apparatus includes: a welding power source unit for performing a welding output; a current detection portion for detecting a welding current; a voltage detection portion for detecting a welding voltage; a calculating section for calculating an increase amount of a welding current per unit time based on a detection result of the current detection portion; a current threshold setting section for setting a threshold of the increase amount of the welding current per unit time; a voltage threshold setting section for setting a threshold of the welding voltage; and an output control section for controlling the welding power source unit based on a detection result of the voltage detection portion, a calculation result of the calculating section, a setting value of the current threshold setting section and a setting value of the voltage threshold setting section, to control the welding output. The output control section stops the welding output when the calculation result of the calculating section exceeds the setting value of the current threshold setting section and the detection result of the voltage detection portion is equal to or less than the setting value of the voltage threshold setting section. <P>COPYRIGHT: (C)2012,JPO&INPIT |
