WELD SEAM INSPECTION WITH PHASED ARRAY TECHNOLOGY MINIMIZES CYCLE TIMES
AUTOMATION MINIMIZE CYCLE TIMES
VOGT ULTRASONICS
WELD SEAM INSPECTION WITH PHASED ARRAY TECHNOLOGY MINIMIZES CYCLE TIMES
VOGT Ultrasonics realized a fully automated Phased Array ultrasonic inspection solution of electron beam welds on rotors for asynchronous motors for a supplier to the automotive industry .
The task was to develop a test system that reliably inspects rotors in the shortest possible time while ensuring a very high level of system availability . The system was designed as an integral part of a production line .
Phased Array and Bubbler- Technique
The used VOGT Phased Array ultrasonic inspection system works immersion-free in bubbler technique . The component is locally moistened with water to couple the ultrasound . This means that a complex and cost-intensive drying stage is not required .
The use of Phased Array ultrasound technology leads to a considerable reduction in testing time . Phased Array ultrasound systems are based on the principle of multi-element testing . A probe can have up to 128 elements , which can be
92 PECM Issue 34 activated electronically either individually or in group . This creates a focused ultrasound .
The inspection software creates two-and three dimensional views of the component with the inspection areas showing the sizes and locations of the detected defects . The advantages of this technique are the beam focusing and control and the possibility of linear or sectoral testing . This allows defects to be detected quickly and reliable with just one probe , independent of direction .
The developed ultrasonic inspection system thus achieves a cycle time reduction by a factor of 30 compared to the conventional inspection method .
Automation creates test reliability
After the rotors have been welded by the customer ’ s system , they are subjected to an automatic quality control in the subsequent process step . A robot feeds them to the VOGT ultrasonic inspection system in 24 / 7 operation . The inspection task is to test the weld seams of the copper components on their both end faces for imperfections .
Optionally , the 0 ° marking of the cylindrical component is made by means of a mandrel , which is driven into the component by a pneumatic stamp . If required , this enables a local metallurgical inspection of the component at the defect location .
The components are tested for defects with a site of up to 0.35mm2 . After scanning the first end face , the component is rotated by a gripper located in the VOGT inspection system , optionally marked again and the second end face tested .
The inspection software evaluates the test data automatically on the basis of previously defined evaluation criteria and communicates the test result ( OK / NOT OK ) to the customer ' s central control system . For this purpose the raster scan software with a stencil synchronization module is used due to the complex , non-contiguous test area . Afterwards , the components are automatically fed by a robot into the further production process or are sorted out as NOT OK . www . vogt-ultrasonics . de