一种实用新型CO2弧焊PWM送丝调速系统

PWM wire feeder timing system in CO2 arc welding machine

关键词:  PWM  调速电路  电枢电压负反馈  送丝速度变化率

Key words:  PWM  timing circuit  negative feedback of armature voltage  wire feed rate variation

摘要:

介绍了一种利用SG3524芯片设计的CO₂弧焊机送丝调速电路。SG3524芯片是一种最常用的性能优良的专用PWM脉宽调制芯片,通过其可实现送丝机通断控制,电枢电压负反馈控制和速度调节控制。较之传统晶闸管调速电路,该电路结构简单,调速性能更佳。通过网压波动试验,电机冷热态变化试验及焊枪阻力试验,验证了该调速电路的可靠性。送丝速度变化率在三种情况下均小于10%,符合JB/T8748-1998,MIG/MAG弧焊机标准要求。该电路已应用于NBC-500KR型焊机上。

Abstract:

Taking advantage of the SG3524 chip a sort of wire feeder timing circuit of the CO₂ arc welding machine was designed.The SG3524 is a kind of special PWM chip with fine performance and most in common use.Through it we can control the on-off of the wire feeder,negative feedback of the armature voltage and adjust the speed.Compared with the traditional silicon controlled rectifier timing circuit,this circuit has more simple structure and better timing performance.By the experiments of electric network voltage fluctuatiuon,the cold-heat state special property variation of electrical machinery and the obstruction inside welding torch,the trustiness of this timing circuit has been verified.In the three conditions,wire feed rate variety are within 10%,and accord with the JB/T8748-1998,MIG/MAG arc welding machine standard demands.This circuit has been used in NBC-500KR welding machine.