Ultrasonic Sensors Make Forage Harvesters More Reliable
Reliability and chop quality are the critical factors in the viability of a forage harvester. Harvesting machinery must guarantee high throughput in addition to maximum availability in the harvesting season. At 1,200 rpm and more than 300 tonnes of harvested crop per hour, the cutting cylinders or cutter heads with their weld-on blade holders are exposed to enormous mechanical loads. Researchers at Fraunhofer IZFP have developed the "LinScanDuo 2.0" ultrasonic sensor system, which can reliably inspect the quality of weld seams. The ultrasonic sensor system is used to improve the quality assurance process in production, thereby increasing the productivity and safety of the whole system.
The customised semi-automatic testing system is based on electronically scanning phased array electronics. Together with the custom-designed inspection system software, the quality of 100 percent of the weld seams on each cutter head can be automatically inspected, analysed, and documented comprehensively in digital format. The two main advantages of phased array technology are a very high testing rate with simultaneous, complete capture of the test volume, as well as the flexible adaptation of the testing system to the blade holders without having to make time-consuming adjustments. The two weld seams on a blade holder are scanned with an electronic cycle, eliminating the need to move the sensor/test head or the test object.
The weld seams are now checked in production, thereby reducing inspection times for the weld seam quality from approximately four hours per cutting cylinder to now just less than twenty minutes at agricultural machinery manufacturer John Deere, for instance.