Abstract
Workpiece clamping in fixtures is an operation made accordingly to a succession of stages and activities. Thus, after an optimal orientation and position of the workpiece has been established, follows the selection stage for the surfaces of the workpiece used for orientation and position. On these surfaces support will placed to remove the degrees of freedom of the workpiece. By orientation and positioning surfaces it is understood an actual surface as well as workpiece edges or points. The proposed informatics system consists of a graphic interface that allows the designer to decide on, the surfaces to be chosen for orientation and positioning. The essence of the system is the framing of each surface in a particular class. The system allows, thus, classification of all orientation and positioning surfaces in certain categories, because selection is only between surfaces of the same type. Also, a classification of surfaces on size criteria is allowed. Further, the surfaces are classified in terms of dimensional accuracy, shape deviations, relative position, roughness and undulations. A last point concerns the quality of the surface layer of the surface, expressed by its hardness. In this way, it provides nearly complete characterization of orientation and positioning surfaces. Next, the designer is presented a list of criteria for the evaluation of orientation and positioning surfaces, from which he selects certain criteria that are feasible for a given situation. The designer can grant weighting or coefficients of importance to each evaluation criterion individually. According to mode each area is assigned in in the above mentioned categories and how each criteria is satisfied, to which the importance coefficient for each criteria is added. In this way, the designer can certainly decide on the selection of the orientation-positioning surfaces. |