Method for inspecting objects particularly for detecting defects or irregularities therein by means of X-radiation and apparatus for performing the method

#1. Field of the Invention

#The present invention relates to a method for inspecting or testing objects, particularly for detecting defects or irregularities therein, wherein the object to be inspected is moved in a rotary manner in an X-ray using a manipulating system, and the X-ray components, comprising X-ray tubes and X-ray detectors, are moved in a translatory manner, as well as to an apparatus for performing the method according to the invention.

#2. Description of the Related Art

#FIG. 1 shows a perspective view of the apparatus according to the invention, in which parts are broken away in order to show the internal structure.

#FIG. 2 shows a perspective view of the gimbal or cardan frame with fixed inspection objects.

#FIGS. 3A-3B show different diagrammatic views making clear the gimbal suspension.

#FIG. 1 shows the fundamental structure of an apparatus according to the invention enabling the method of the invention to be performed. The test or inspection system comprises a radiation protection cabin 14, an X-ray tube 12, an X-ray detector 18, a part support/pallet 30, and an inspection/test object 19. Although FIG. 1 shows only one inspection object on a pallet 15, there can also be several objects on a single pallet. FIG. 1 also shows gimbal frames 16 and 26, and drives 22 and 23 for the gimbal or cardan axes in the vicinity of the center of gravity, x-y plane translatory movement units 17 and 13 for the tube and detector in the X and Z-direction, both on the base and below the cover.

#The testing or inspection sequence is as follows:

#The parts or objects are conveyed into the cabin and the radiation protection, e.g. a radiation protection cabin door, is closed. The X-ray is switched on and there is a move up to the first inspection position for the first inspection object. For this purpose, the tube and detector are brought into the appropriate position. The drives of these translatory axes can be coupled, so that the beam always strikes perpendicularly in the center of the detector. Simultaneously, using the two drives 22 and 23, the frame is tilted in such a way that the correct transmission angle for the inspection object is reached. Since, as will be shown hereinafter, the objects are fixed to the pallet, angles above 45° are possible without the object sliding. The two frames are balanced in such a way that virtually no forces are required in order to maintain the positions reached. The detector is used for taking an image and it is passed onto a screen or computer for evaluation purposes. Then, in parallel, the tube and the detector are moved to the next position and the two frames are tilted in the correct angle. The next image is then taken. This procedure is repeated until the object or all the objects on the pallet have been inspected. This method makes it possible to achieve the necessary transmission angles and to move to all positions.