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|NDT.net Issue - 2020-07 - NEWS ||NDT.net Issue: 2020-07|
Publication: e-Journal of Nondestructive Testing (NDT) ISSN 1435-4934 (NDT.net Journal)
Automatic Phased Array Detection of Electronic Beam Welds for Vehicle GearsDoppler Electronic Technologies Co., Ltd4, Guangzhou, China
The automobile transmission gear is the key component in the process of automobile transmission, which is directly related to the safety of automobile driving. Due to welding process, welding operation or equipment problems, it inevitably will produce a variety of manufacturing defects, such as pores, cracks, slag or lack of fusion. In order to ensure safety driving, the relevant regulations in China require to cary out strict weld quality testing of transmission gears before out of factory.
For internal defects, some production plants determine whether the batch of samples qualified through observation of the status of anatomical samples, which can not effectively protect product quality. Some manufacturers have adopted conventional ultrasonic detection technology, through a single crystal probe rotating one circle to complete the weld detection, but the coverage is insufficient, there is a risk of missed detection.
In view of the above problems, a set of automotive gear weld automatic detection system has been developed, and the use of phased array ultrasonic technology can realize multi-angle detection, which greatly improves coverage. The gear plate is very thin, only 2.4mm, and in order to ensure that the phased array probe has better thin-walled focusing capacity and large-angle beam deflection capability, Doppler’s self-focused phased array probe and specially designed short front large angle wedge are used to achieve optimal detection results.
Detection schematics / Schematic of beam cover
According to the high efficiency and intelligent detection demand, there comes another important problem faced by researchers, that is how to identify defects among complex image signals such as the inherent structure echo signal. After further study, we used double matrix-box gates displayed in the phased array S scan view, to avoid other non-defect inherent structure signal according to the weld structure, position etc. In this way, as long as the box gate to get over-standard reflection signal, the system can be informed and the problem gear work pieces automatically assigned to the bad product area, and vice versa, the work piece into the qualified product area.
Non-defective inherent structure signal / Defect signal in the box gate
Visit: Doppler Electronic Technologies Co., Ltd