Research And Implementation Of 3D Automatic Marking Technology For Shaft Parts

With the introduction and implementation of three-dimensional CAD standard,the function of two-dimensional engineering drawings has been gradually weakened.The use of three-dimensional software platform can improve the efficiency of product development,so there is an urgent need for three-dimensional CAD system to accurately and quickly provide process size information related to parts.In this paper,an automatic dimensioning algorithm for three-dimensional axle parts is proposed,and an automatic dimensioning system for axle parts is developed.The contents of this paper are as follows:According to the requirement,the overall scheme of dimension automatic marking is designed and divided into reasonable sub-modules according to the different functions;the information of parts is organized and extracted based on model features,and the features are classified according to the priority of feature shape and the size of axis coordinate value;according to the characteristics of axle parts,the position relationship between the features of axle segments and other features and the length and diameter of parts are based on the features of axle segments.The type of parts can be judged by comparison.The problem of dimension redundancy judgment is transformed into a graph theory problem.The axially end coordinate value corresponds to the node number of the graph and the connection between the corresponding nodes.The connectivity of the nodes is judged by the method of searching and collecting,and then the dimension redundancy is determined.This method is applicable to the dynamic graph.According to the other characteristics of the shaft,the process datum is automatically selected,and then the reasonable dimension annotation sequence is used to automatically select the process datum.The dimension of parts is marked.The time consumption of each module is counted for performance comparison.Based on UG platform and using C++ programming language,a labeling system for shaft parts is developed.Its functions include judging the type of current parts,automatically labeling the process size of current shaft parts,providing process information(tolerances,roughness,chamfers and rounded corners)by manual labeling in an interactive way with users,and realizing the labeling of complete process information for parts.