Research On The Key Technology Of Computer Aided Quotation For Cavity Moulds

Moulds and dies are vital technical equipments in the field of modem manufacturing industry. Its level is the symbol of manufacturing level and throughput of a country or an enterprise. With the developing of the modern industry and the sharp shortening of the period of products updating, the demand of moulds and dies expands increasingly, which makes the roles more and more important in the development of all the national economy. The rationality of moulds and dies quotation is related to users' benefits, the makers'payoff, the formulation of the market competitive strategies, the reality of preconcerted aims, and so on. So determining the prices of moulds and dies properly is one of the most important contents of managerial decision-making for moulds and dies manufacturing enterprises. The conventional experience quotation methods of moulds and dies, such as quotation by the proportion of man-hour and materials, weighing, etc, have shortcoming such as depending too much on experience, difficulty in standardization and normalization. Although the calculating quotation methods of moulds and dies, such as man-hour method, have high precision of quotation, and standard and normal process of quotation, they can't meet the requirement of rapid quotation in the new environment because complicated calculation process taks too much time, especially quoted by manual work. With the development of the modern science and technology, such as forecasting technique, computer science, network technique, information technique, database technique, etc, it becomes possible to realize Computer Aided Quotation of Moulds and Dies(CAQMD). Therefore, it is significant, feasible and practical to research CAQMD.The research object of the quotation system of moulds and dies in the dissertation is cavity moulds, and the system is brought forward and improved against the deficiency of present quotation system of moulds and dies in the aspect of information distilling, quotation method, network, etc. Through feasible arithmetic, the system distills quotation information automatically from the DXF files of workpiece drawings, which is to advance the extent of automatization and intelligentizing. On the base of man-hour quotation method, a new quotation method, geometry-similarity-calculation quotation method, is brought forward aiming at the mould quotation of serial product in the dissertation .This quotation method has the advantages of high quotation precision, simpleness and practicality in the application of mould quotation of serial product.Based on above, the following main problems are discussed in the dissertation: 1. Distill quotation information automatically such as dimension precision, surface finishment, shape complication, ect, from the DXF files of workpiece drawings, and create workpiece information database faced on mould quotation.2. Study the principle and formula derivation of geometry-similarity- calculation quotation method, which resolves some problem of geometry-similarity-calculation quotation method in theoretics.3. Organize and establish the databases of system, including standard mould frame database, standard part database, materials database, etc.4. Study the security and maintenance of system. The system is more secure and reliable, and is more convenient to maintain system data efficiently through the security- entering module and the data- maintenance module.According to above study, a prototype system is developed on the WINDOWS NT platform by POWERBUILD & SQLANYWHERE of SYBASE corporation.