Development And Realization Of Intelligent Machining Process Design System For Mould Parts

With the development of modern manufacturing industry toward automation and intelligence,realizing the intelligent generation of processing process files,improving the efficiency of process design and shortening the manufacturing cycle of mould products have become the internal demand of the transformation and upgrading of the manufacturing industry.As an important part for the research and development of mould products as well as the link between product design and manufacturing,machining process design aims to develop the most reasonable processing scheme and work out the machining process route based on the characteristics of the product such as material,structure.At present,the traditional processing technology of mould parts mainly depends on the experience of process engineers and manual preparation,which has low efficiency,long design cycle and cannot adapt to the needs of mould small batch,multiple varieties,efficient and intelligent production.Therefore,the development of intelligent machining process design system,which can automatically obtain the feature information of parts,make intelligent reasoning decisions,match and store the machining process according to the 3D model of the machining parts,has become a research hotspot to realize the automation and intelligentization of the machining process design process.In this paper,the mould machining process design system of mould parts was selected as the research object,the design requirements of mould parts machining process was analyzed in terms of practicability,rapidity and intellectualization,the structure analysis of the system architecture and overall frame was conducted on the basis of a structured method.Combined with the actual production situation of mould industry as well as the process characteristics of mould parts design and manufacturing process,the operating principle of the system was analyzed,and the system development platform based on B/S framework was established.Focusing on the problem that the information of mould parts is difficult to be obtained automatically during the machining process design,a method of importing the 3D solid model of mould parts into the powermill processing software and combining the information modeling technology and database design technology was proposed to construct the information acquisition model of mould parts.Through analyzing the concept,main characteristics and modeling process of metamodel,the similarity element matrix and similarity element metamodel were established.Using the feature evolution mapping technology,the part information mapping metamodel was constructed.Based on the Petri net technology,part information acquisition process was established.And adopting secondary development technology of powermill and SQL technology to realize the automatic acquisition of mould parts information.Combined with the existing form and demand of process knowledge of mould parts,the process database was designed,and the process knowledge exchange and data processing method were studied.The dynamic database structure was used to store process knowledge and complete the construction of process database.According to the high similarity of machining process of mould parts,a case-based retrieval method was proposed,and the retrieval process relying on case-based reasoning was constructed.Aiming at the weight problem of similarity element attributes in similarity calculation,a method of determining the weight of similarity element attributes was developed on the basis of rough sets.Aiming at the problem that the similarity of mould parts could not be measured,an overall similarity calculation model was builton the basis of weights and local similarity,and the similarity calculation of the obtained part information was carried out.Aiming at the problem that the similarity threshold is difficult to be determined,a numerical calculation method is proposed to determine the similarity threshold by the selection of regulatory factors.A method combining K-means mould parts clustering with KNN algorithm was proposed to realize the fast and accurate matching between the parts to be manufactured and the parts in the example library.The validity of the KNN algorithm was verified by the test of the number of instances and the retrieval time.Finally,the method of case revision was studied,and the new valuable machining process examples were stored in the case library to realize the real time update of the case library.Based on the above research contents and using Win Form framework,the intelligent machining process design system of mould parts was developed which consists of six functional modules,including user login,model download,format conversion,information acquisition,process decision-making and process management.Through the analysis and design of the software and hardware platform of the system operation,the C# and VB.NET language programming was selected,and the Visual Studio 2012 was used as the application development platform,the SQL Server was regarded as the database development platform,FTP Server was taken as the code and data operation platform,and then the system prototype of intelligent machining process design of mould parts based on B/S framework was developed,and the interface of each function module was designed,and the intelligent design for machining process of mould parts was realized.The practical test results show that using the developed intelligent machining process system,the time of downloading part model is shortened by 50%,the time of analyzing part model and determining the machining process is shortened by 64.5%,and the time of designing the machining process of mould parts is shortened by 40%,and the automatic and intelligent generation of the machining process of mould parts is realized.At the same time,the unreasonable process design is reduced by82.8% and the missing process is reduced by 69.6%,which greatly improves the machining efficiency and quality of mould parts.