The Centering Method Of Crankshaft Finished Product Quality Centre And Its Algorithm Research

The crankshaft processing is a key issue in the engine manufacturing. It's difficult to process as its asymmetric structure. The center hole is an important position datum and the main factor to ensure the quality of crankshaft machining.In the crankshaft processing industry, the study of the locating datum to play center hole has been a hot topic.By compare and analyses the traditional positioning method based on further exploration, the paper propose a concept of the centering method of Crankshaft finished product quality centre. Namely through computer vision to get the crankshaft geometry information rapidly, then reconstructing the rough's three-dimensional model, realizing the best matching for the crankshaft finished CAD model and the rough's reconstruction model. Under the premise of a certain match criteria, it can forecast quality center of the finished crankshaft, which can be regard as the locating datum center. This method could solve the dynamic imbalance affect for the crankshaft machining quality theoretically and the greatest difficulty in crankshaft machining as well. Then with an example for the four-cylinder cast crankshaft, the paper do some research about the key problems, which all base on the course for this method's implementation. And the main contents are as follows:(1) It analyzes the important status of the center hole during the crankshaft processing, according to the current deficiencies of the crankshaft center hole for positioning, it propose the concept of" the centering method of Crankshaft finished product quality centre ", then concludes the advantages of this centring process and some key research problem.(2) Based on experimental crankshaft rough, through the analysis to its structure function, it adopt the simplified project that using the CMM as a tool to get geometric information of the crankshaft rough surface. Using the reverse engineering technology, it generates three-dimensional reconstruction for the crankshaft and crank rough CAD model.(3) According to the inheritance relationship between the finished crankshaft and crankshaft blank, it could realize the predictable finished crankshaft product quality center axis.Through crank discrete, data processed, the computational mathematics model's established, then it can get the finished crankshaft product quality center axis in Matlab by iterative optimization when it satisfied the condition of dynamic balance.(4) The paper study on software integration problems that base on realizing the centering method of Crankshaft finished product quality centre, it puts forward the implementation of the second development plan on the Solidworks platform. Then, as an example for secondary development project, it studied the reconstructed crankshaft finished CAD model, which be regard as a reference for the follow-up fully integrated research.The paper proposed the centering method of Crankshaft finished product quality centre, which innovational changed the traditional research methods to determine the location of the center hole, each key issues also has some innovative ideas.The research results will push forward to the change of the centering method of the crankshaft process, that is very meaningful for the engine manufacturing, and in line with national industrial demand.