CO_2焊短路信号的检测

Signal detecting of short-circuit in CO_2 welding

根据CO2气体保护焊短路过渡过程的负载特点,利用电压比较器、du/dt线路和数字电子线路,设计了短路检测电路和短路液桥缩颈检测电路。短路检测电路利用焊接电压的变化确定熔滴短路的状态和时刻,能正确区分引弧短路与熔滴短路并考虑瞬时短路对过程的影响;缩颈检测电路利用焊接电压微分du/dt检测液体小桥产生缩颈爆断的时刻,对瞬时短路可能产生的不良影响不做反应。对所设计的电路成功地进行了模拟实验和实际试验验证。

According to the load properties of short circuit transfer in CO 2 welding,short-circuit detecting circuit,including primary short=circuit detecting and liquid bridge pinch detecting circuit,is designed on the basis of voltage comparer,du/dt and digital circuit.The short-circuit detecting circuit can determine the short-circuit time ,correctly distinguish the short-circuit from arc stricking and droplet and confine the effect of momentary short.Also,the latter detects liquid bridge pinching by welding voltage differential du/dt,and prevents the unfavorable effects from momentary short.The designed circuit has passed the simulation test and welding experiments.