| 摘要 |
In the case of casting moulds produced from a foundry sand consolidated by means of binder, visual checking for freedom from defects presents considerable problems. On the one hand, it is possible to detect only gross defects such as broken edges or the like and, on the other hand, the attention of the personnel carrying out the checks wanes in mass production and the reliability of the checks thus decreases. The casting mould is now exposed to a source of radiation and the distribution of the intensity of radiation allowed through in each case over the area of projection is recorded in grid or line form (actual image) and compared with the intensity distribution of a tested sample mould (desired image). Deviations are detected electronically and trigger a signal, for example an actuating signal. By mechanising the checking for defects, it is possible to achieve considerably shorter cycle times and, by virtue of the method chosen, it is possible to achieve a higher resolution which allows defects in the millimetre range to be detected. The particular advantage lies above all in the fact that even areas of the mould which can not be inspected from the outside can be checked.
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