Research On Key Technologies Of Ultrasonic Detection For Casting Defects Of Aluminum Alloy Wheel Hubs

As one of the important parts of the automobile,the aluminum alloy wheel hub directly affects the safety of the whole vehicle,so the quality and safety of the aluminum alloy wheel must be guaranteed.In the low-pressure casting process of aluminum alloy wheels,may appear typical casting defects such as stomatal,dispersed shrinkage,shrinkage cavity,cracks,etc.Therefore,in order to ensure the safety of the aluminum alloy wheel hub and meet the goal of safe driving of the whole vehicle,it is necessary to carry out quality inspection on the aluminum alloy wheel hub blank during the manufacturing process.Moreover,since the impact surface of the rim surface of the hub is relatively large during driving,it is an important research issue to ensure the quality and safety of the rim surface.Aiming at the quality and safety of aluminum alloy wheel rim surface,ultrasonic pulse reflection technology is used to non-destructively test for the typical casting defects inside the aluminum alloy wheel rim surface.At the same time,in order to reduce the influence of manual detection on the detection results,an automatic scanning structure for ultrasonic testing was designed to realize ultrasonic automatic detection.Firstly,the basic principle of ultrasonic detection is briefly introduced.The self-designed ultrasonic automatic detecting device of aluminum alloy wheel casting defect and working principle are introduced.Then,the aluminum alloy wheel rim surface detecting equipment and parameters are set,and ensuring that the pose of the ultrasonic probe meets the detection requirement by analyzing pose of ultrasonic probe.Finally,the acquired ultrasonic echo signals are analyzed and processed by spectrum analysis and time-frequency analysis to realize that the type,spot,quantify of the typical casting defects in the aluminum alloy wheel rim surface.Based on the above techniques and methods,an automatic detection system for casting defects inner the rim surface of aluminum alloy wheel is constructed by ultrasonic water immersion reflection method.Through the experiment and simulation,the characteristics of ultrasonic echo signals are extracted and analyzed by spectrum analysis and time-frequency analysis.This could determine type,spot,quantify of typical casting defects inner the rim surface of aluminum alloy wheel.The feasibility of this system is verified.