100% Inline surface defect inspection guarantees long life of fuel pumps
Fuel pumps must operate trouble-free behind the scenes during the whole life of the automobile. A defect-free surface of the pump tube is a prerequisite for perfect corrosion protection and thus a long life of the fuel pump. To guarantee this, Präschu Umformtechnik has chosen an in-line inspection system from OCTUM for the automatic surface defect inspection of the pump tubes.
The tubes of fuel pumps are produced fully automatically in a deep drawing process. Tubes are washed after deep drawing and then presented to the image processing system decollated and in the correct position over a chute with stoppers. A roller mechanism turns the parts around their longitudinal axis by 380 degrees underneath the camera. The CV-600 inspection system takes the camera images in high resolution with a line scan camera and evaluates these automatically. The CV-Inspect system software operates with local adaptive methods to cope with brightness changes to compensate for process-related or material-related fluctuations in the appearance of the tubes after the deep drawing. The sensitivity of the defect segmentation and of course also the defect tolerances can be configured by the operator. At this time, defects from a size of 0.2 mm x 0.2 mm upwards lead to rejection of the part. All detected defects are color marked in the grey image. Inspection regions and excluded areas can be set flexibly. The overall cycle time is 1.8 seconds, image acquisition and inspection is completed within 1s.
At Präschu, more than 2.1 million parts per year are produced. Good parts are transported directly for packing. This future-orientated investment is part of the 0 ppm strategy of Präschu Umformtechnik and guarantees the continuing high level of quality in the production. Because of the positive experience made with the installed inspection system and the quick return on investment as well as other cost savings, additional surface inspection systems are being planned for other lines and products.