Development and application of the hottest CAPP sy

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Development and application of CAPP system

with the popularization and application of computers, it is possible to carry out process aided design by computers. The application of CAPP (computer aided process planning system) will provide a practical way to improve the quality of process documents, shorten the production preparation cycle, and liberate the majority of process personnel from tedious and repetitive work

1 CAPP system development

1.1 overall requirements for CAPP system development

according to the process of enterprise information construction and the characteristics of factory production management, this paper puts forward the overall requirements for the CAPP system to be developed

1.1.1 practicality

it can make full use of the experience of process designers and existing mature processes, provide process knowledge, assist technologists in process calculation and process decision-making, and can quickly and efficiently generate various required process procedures

1.1.2 product oriented

considering that the product is the basic object of the enterprise's product design, production preparation, production management and cost accounting, the system is required to be able to carry out process design and process management for products, cover all process types of products, and realize integrated process design and process management

1.1.3 integration

from the perspective of products and their whole life cycle, realize the integration of process design and process management, and meet the information integration requirements in PDM and ERP environment

1.1.4 standardization

the system must ensure the standardization and standardization of process design

1.2 functional requirements of CAPP system development

based on the overall requirements, specific functional requirements are formulated according to the requirements of factory process design and process management

1.2.1 product data management

the system can provide product data management functions, including product creation and deletion, adding and deleting parts and components in products, browsing, modifying parts and components information and other functions. It can directly read product data from CAD system, save 3 tons of standard coal per year, and avoid inefficiency and inconsistency caused by repeated input

1.2.2 process card design

the system can easily design various process cards, including machining process card, forging process card, welding process card, heat treatment process card, casting process card, assembly process card, electroplating process card, material process quota list and summary table, etc

1.2.3 provide a variety of process design methods

the system can provide a variety of process design methods, including interactive and different types of retrieval methods, to adapt to different products and different types of process design requirements. For interactive design process, relevant data resources can be provided according to different process disciplines to help process designers calculate the process and quickly select the required resources, such as machine tool equipment, tooling and other parameters and automatic calculation of material quota

1.2.4 it really plays a bridge role in process design

the system can directly read the design drawing information and graphic information of CAD upward; the system can provide the required process design information such as man hours, materials, process routes, process equipment for PDM and ERP systems downward, so as to realize the real information integration

1.2.5 automatically generate various summary tables

the system can provide the function of automatically generating process documents, such as product process directory, parts processing route table, parts production and processing directory, outsourcing parts list, various parts list, special process equipment list, material consumption process quota list, etc

1.2.6 provide basic process data

the system can provide material library, profile specification library, equipment library, standard tool library, standard measuring tool library, etc., and can transfer the required related information to the corresponding position of the process card at any time when designing the process, and maintain the modification consistency of the related information

1.2.7 process card format drawing and management

the system can provide more than 40 process cards and management documents that meet the requirements of the factory. At the same time, tools for drawing and defining process card format are provided to facilitate the expansion of process document system in the future

1.3 selection of system model

the enterprise made a comprehensive investigation on many domestic CAPP software providers, mainly made a careful and detailed comparison on the strength, software development ability, software functions and the company's technical support and services to the enterprise, and finally selected the starting CAPP system. In addition to meeting the specific requirements of the project, the system also has the following characteristics: (1) typical processes to meet their own needs and even the demand management function of the world, which can continuously accumulate the typical processes of enterprises in the process of using the system. In this way, when designing new processes, we can quickly generate new processes by retrieving typical processes and making a few modifications, which is conducive to the inheritance and promotion of excellent process experience; (2) The system provides process submission, process audit, process standardization, process countersignature and process change functions; (3) Powerful function of generating process diagram and marking. Graphics and images in various formats can be embedded, and large amounts of money and manpower can be invested to modify the discussion links one after another; It can also directly read the graphics drawn by open-ended CAD, and the system provides local section, local amplification and positioning clamping symbol library; It is embedded with various special engineering annotation symbols, and can quickly add the required special annotation symbols; (4) The formula calculation and formula manager of the system can reduce the weight by more than 50%. The system provides the formula library of material quota calculation and man hour quota calculation, and can also expand the special formula by itself; (5) Provide a variety of design document retrieval methods based on product, part name, material name, etc., which are efficient and reliable to use; (6) It can be integrated with a variety of PDM, ERP and other software to realize the automatic input of enterprise basic data

1.4 system development

relying on the technical resources of the company's process system, taking the company's network platform as the transmission medium, and for the purpose of improving work quality, reducing manufacturing costs and shortening production cycle, the following five modules have been developed locally: (1) the development of material consumption process quota computer-aided design system; (2) development of computer-aided preparation system of process route; (3) Computer-aided development of process document design system; (4) Integration of product process data; (5) Product data service system

according to the actual process design management process, each large module is subdivided into multiple sub modules for development respectively. Among them, a lot of work has been done in the auxiliary system of material consumption process quota. After analyzing the preparation process of the traditional process quota of labor and material consumption, we found that its biggest feature is repeated labor, and the high labor intensity has become inevitable, which has caused some deeper problems. For example, when the product contains many parts, in addition to the considerable work intensity, it is also very difficult to classify and summarize thousands of parts by hand. After carefully studying its working process and results, we subdivide the material consumption process quota auxiliary system into three sub modules: the preparation of material consumption process quota schedule, the establishment of borrowed parts list library, and the generation of material consumption process quota summary

when developing these three sub modules, the following problems are mainly solved: (1) data source. In order to reduce the input amount, various characteristics of materials (such as material name, material brand, technical conditions, variety and specification, etc.) are associated; (2) Standardization, the writing method of materials, the tables used, and the calculation method of material excess elimination quota need to be standardized and standardized, and the writing method of professional process terms should be unified, so that the computer can correctly classify and summarize; (3) Establish the calculation formula of consumption process quota of various materials to ensure more accurate calculation and better consistency of calculation results; (4) Solve the problems of whole piece borrowing, parts borrowing, general parts and so on; (5) Solve the sorting problem of some special materials in the summary table; (6) Solve the problems of data correctness verification and error correction of material quota quantification

2 application effect of CAPP

after a period of operation, the function of CAPP system has been continuously expanded and improved, and the efficiency, quality and standardization of system process design have been significantly improved, which is specifically reflected in the following aspects: (1) improve the efficiency and quality of process specification design, shorten the technical preparation cycle, and liberate the majority of process personnel from tedious and repetitive work, Process personnel have more time and energy to invest in process test and process research; (2) In terms of computer-aided design of material quota, it fills the gap of the company. The material process consumption quota, material summary and single table are automatically calculated and generated by the computer, which greatly shortens the preparation time of the whole parts list and summary table, and greatly improves the accuracy at the same time; (3) Using the function of network authority, it is convenient to browse and output process document data in different places, work across disciplines and departments, reduce intermediate links, and improve work efficiency and quality; (4) The application of CAPP system promotes the standardization of professional terms in enterprises and ensures the consistency and standardization of process design; (5) The application of typical processes, constantly accumulating and managing excellent process experience and process knowledge, has played a great supporting role in the innovation and sustainable development of enterprise process technology; (6) The system can provide product data service functions for production departments and management departments, avoiding duplication of labor and improving work efficiency

3 conclusion

with the establishment of enterprise PDM and ERP systems, design data flow, process data flow and management data flow will be connected. The system extracts the product design information from the design drawings (electronic documents), generates the product structure tree, and provides the data flow to the downstream departments after the CAPP system, which greatly shortens the product development and production cycle and enhances the competitiveness of enterprises. (end)

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