Study On The Design Of Resistance Spot Welding Quality Monitoring System For Sedan

Resistance spot welding because of its advantages of high efficiency and simpleoperation is widely used in industrial production, especially in the automotive industry, carwhite body almost entirely complete by the spot welding method, welding quality has agreat influence on the quality of car body, thus guarantee the quality of spot welding isespecially important. Common quality problems mainly include virtual welding, spotwelding desoldering, crack, shrinkage cavity, etc. The detection of the spot welding qualityis mainly used artificial destructive experiments method, this method is of low efficiencyand waste materials. In order to be able to achieve the purpose of rapid and simpledetection of welding quality, this paper studies a set of resistance spot welding qualitymonitoring system of sedan white body.Spot welding welding parameters mainly include the welding current, voltage betweenelectrodes, electrode pressure, welding time and electrode displacement and so on, theseparameters are closely related with spot welding quality. Monitoring the spot weldingquality monitoring system mainly monitor welding current, electrode voltage and electrodedisplacement in the process of spot welding, by means of real-time, on-line monitoringthese three parameters,we can extracted the characteristic values related to the quality andanalyze it, so as to achieve the purpose of monitoring the quality of spot welding.The car white body resistance spot welding quality monitoring system consists ofhardware part and software part, the hardware system mainly includes: LHA-8000-atype of hall current sensor, LE-300type grating displacement sensor, electrode voltagemeasuring device and USB08222C10data acquisition card; Software part includes: dataacquisition program and quality judgment program writted in LabVIEW software. Wetested for the quality monitoring system in a TN-100power frequency ac pneumatic spotwelding machine, the test results show that the quality monitoring system can accuratelyand reliably acquire the characteristic signal of the spot welding process, through thehandling of the characteristics of these signals,we can judge the quality of spot welding.