Research On Detection Device For Nugget And Surefce Morphology Of Spot Welding

Resistance spot welding is an economic and efficient connection type, which is usingwidely in modern manufacturing industry, such as automobile, railway vehicle and so on.Because of the influence of the technological characteristics in spot welding process, surfacewelding indentation and solder melt nuclear will influence the surface quality andmechanical properties of the products. At present, although the application of new typewelding materials and new welding technologies ensure the quality of products largely,because of the nonuniformity of spot welding joint performance and the complexity of thestress distribution, and there is no guarantee that no welding defects are produced absolutelyin welding process, it is important to test the quality of Spot weld in the process of industrialproduction and manufacturing. Through thw process of Spot weld formation, electrodepressure on the joint area, generating resistance heat and heating the joint area to melt orplastic state to make it form atoms combine. This process occurs in a closed condition,which is hard to observe, causing great difficulties for the quality detection of spot weldingjoint. With the development of manufacturing, industrial production process requires anaccurate, reliable and convenient method to test the quality of spot welding joint.which canrealize the automation, Intellectualization and visualization of production testing equipment.Reflecting joint fusion nuclear and surface topography visually and measuring spot weldingjoint indentation depth and weld nuclear size accurately.This paper designs a scanning detection devicese realizing the automation andintellectualization of the detection on Spot welding joint surface topography and meltnuclear diameter. Use ultrasonic nondestructive testing C scan image measurement methodto test diameter of pot weld nugget, obtaining the ultrasonic scan images. To deal with thenoise of the ultrasonic scanning original image, highlight the scan images on the weld nuggetedges and details characteristics, making the calculation results of the C scan image measurement method more accurately. Use laser displacement dme to test the depth of spotweld indentation. Use the industrial computer control data acquisition card to get the distancesignal between the spot weld creasing surface signal and the laser displacement distancesensor, then draw the imageof the indentation surface. Distance signal changes is used todetermine the indentation edge position. Through the built-in algorithm get the largest depthof indentation, the average of indentation depths and the area of the indentation. At the sametime, eliminate possible errors in the experiment through the built-in algorithm to get moreaccurate indentation depth.