Research and application of computer aided process

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Research and application of computer aided process management

0 preface

due to the changing market needs, the current manufacturing industry is facing the urgent task of accelerating the development of new products. Therefore, we must change the old enterprise management mode and improve the adaptability. One of the most effective ways is to use computer-aided process management

process management is an important part of enterprise management, covering and contacting all departments of the enterprise. It includes a series of process preparations such as process analysis and review of product drawings, preparation of process schemes, preparation of parts and components division catalogue, preparation of process procedures and design of process equipment, formulation of material consumption quota and man hour quota. The quality of process management directly affects the development of production. Therefore, developing computer-aided process management is of great significance to improve the level of process work and enterprise management and promote the technological progress of enterprises

1 overall plan of computer-aided process management

the specific method of using computer technology for enterprise process management is to establish a complete set of high-quality management modules (see Figure 1), and then include all data processing tasks (such as process design, approval and management of process documents, tooling design, etc.), and realize the computer integrated system through local area

Figure 1 overall scheme of process document management module

schematic diagram of computer integrated manufacturing system

2 process design

preparation of process procedures is a very important and complex work in process preparation. The quality of traditional manual design mode completely depends on the technical level and work experience of technicians. Without advanced aluminum lithium alloy materials, components have accounted for 20% of the total aircraft materials; Boeing 787 and eh101 multi-purpose helicopters also adopt a large number of aluminum lithium alloys with unified design standards. Different people will also have great differences in the process design schemes of the same or similar parts. In the process design of new parts, even if the process scheme of similar parts in the past is adopted, the "new" process without much change must be redesigned. Craftsmen have been engaged in unnecessary repetitive work for a long time, with heavy workload and extended production preparation cycle. This situation can be changed by using computer for process design

the method of computer-aided process planning is: first, apply group technology, classify and code various parts with similar or the same characteristics, adopt a unified solution, and use the technology and experience of technical experts and old technicians to optimize the design of the process, so as to realize the standardization and standardization of the process, and then use the computer to process the data and store it in the computer, so as to provide a template mode for the future process design

during process design, try to move closer to CAPP (Computer-Aided Process Planning) mode, so that it can be easily transplanted to the computer when conditions are ripe. When designing CAPP system, we should consider the problems of development and expansion, which is convenient for users to use and maintain, and for the continuous correction and improvement of the system in production practice, and the kernel of the system will not be changed during expansion

3 process may return to the market in 3 (4) months to replenish inventory equipment design

process equipment is an important means to ensure the implementation of process procedures and improve and ensure product processing quality. Tooling design is an important part of process management. It is the stage with the largest workload and the longest cycle in production technology preparation. The traditional manual design mode is difficult to design tooling with stable quality in a short time. It is possible to design process equipment with high serialization, standardization and stable quality through computer

3.1 tooling design module

process design refers to group technology and standardized design, and tooling design can correspondingly achieve a certain degree of similarity and consistency, so as to create favorable conditions for computer-aided tooling design. Therefore, it is necessary to carry out classification optimization and standardized design of process equipment with the same function and similarity, and use computers to provide various cutting tools, measuring tools, fixtures Establish standard graphics and data modules for molds and tooling cards (see Figure 2)

Figure 2 Schematic diagram of computer-aided tooling design module

to realize the tooling design module, it is necessary to establish the design calculation module and the standard graphics module

The calculation flow of the design calculation module is shown in Figure 3. FoxPro programming language is used to design and calculate some complex tools, such as gear shaper cutter, gear hobbing cutter and spline broach. The calculation work takes a long time in the whole design process, especially the displacement tool involves the selection of displacement coefficient. Manual calculation is carried out by experience and needs repeated verification to achieve the best design effect. The optimization calculation by computer can be completed in a few minutes as long as the part parameters, initial values and calculation accuracy are input. It greatly improves the work efficiency and solves the problems of long cycle, low efficiency and poor accuracy caused by manual calculation

Figure 3 calculation process of design calculation module

the design process of standard graphics module is shown in Figure 4

Figure 4 design process of standard graphics module

in the design of tools and measuring tools, a tool quantity data processing system is developed by combining FoxPro database and AutoCAD. First, the tool and measuring tool graphics library and slide legend library are established in CAD, and then the main dimensional parameters of various designed tools and measuring tools are input into the database system for timing call

for example, design a reamer, enter CAD first, and find out the structure (front guide or rear guide) and tool code in the slide legend library. Then enter the "tool quantity system database", call out the tool database of this code, enter the main size parameters to be designed, and check whether there is a tool of this size. If any, it can be substituted according to the drawing number; If not, it needs to be redesigned. Call out the reamer graphics of this specification from the standard graphics library, make necessary modifications, and a new reamer design will be completed immediately

in fixture and mold design, it is necessary to establish common typical structure standard graphics modules in CAD. When designing a new tooling, you only need to search according to the function of the tooling, find out the standard model of the tooling, and then make necessary modifications, additions or deletions according to the specific requirements of the process specification, so that the design drawing of the new tooling can be quickly produced. This kind of process equipment diagram designed by serialization and standardization not only has stable and reliable design quality and short design cycle, but also is convenient for organizing production and manufacturing

in order to facilitate the management of tooling, the filling of tooling cards, the change and cancellation of tooling, the statistics and reports of tooling can be programmed with FoxPro language for computer management, and the management module is shown in Figure 5. The use of computers for routine management work such as tooling statistics and inquiry reduces the labor intensity of tooling designers and allows engineers and technicians to spend more time in design

Figure 5 tooling card management module

3.2 tooling CAD application design

at present, the common practice in China is to use AutoCAD as a support platform to develop some professional CAD software suitable for their own design characteristics. Such as tooling CAD system, in which the commonly used fasteners, technical standards, geometric tolerances and other drawings are programmed with AutoLISP language; The menu is programmed with C language, and the icon menu is designed with dialog box control language (DCL) to realize its own function of pop-up dialog box; When the technical conditions and instructions are in both Chinese and English, in order to achieve the same height of the text and the beauty of the drawing, use AutoLISP language programming to complete the simultaneous input of Chinese and English; The table adopts the interface provided by FoxPro and AutoCAD to realize data processing (, modification). Through the tooling CAD system, we can greatly improve our work efficiency and standardize the tooling drawings. The composition of tooling CAD system is shown in Figure 6

Figure 6 structure diagram of tooling CAD system

4 process document management

the management of process documents is the management of technical preparation data, including: parts and components division table, outsourcing division table, forging and casting Division 1 turn down the printer front cover table, material quota table, etc. It is not only the basis of division of labor, but also the main basis for various technologies and production preparations before production. For example, the process system should do a good job in the preparation of process regulations, tooling design, technological key process tests, etc. in advance, the procurement of materials and purchased parts of the supply department, and the fixed-point production of outsourced parts and forging and casting blanks of the outsourcing department. The quality and cycle of these preparations play a key role in the whole production process and progress. In order to ensure that every link of production is orderly, it is necessary to update the traditional management means and adopt computer management to improve the quality of process preparation and shorten the preparation cycle

the process document management module is shown in Figure 7. Database management systems such as parts and components division table, outsourcing division directory, forging and casting division directory, and material quota table are established on the computer. For example, after computer management, group data processing can be carried out on the parts and components division table of the same series through the database, and there is no need to copy these similar "new things" by hand. This can not only greatly reduce the repetitive work of technicians in the working process, but also ensure the consistency and accuracy of parts and components division. At the same time, it is also convenient to classify and count various specifications of different material brands, and analyze the specifications with high frequency in the material brands, so as to reduce the grade of material specifications, so as to achieve the goal of facilitating the management and procurement of materials and minimizing the consumption of materials. Computer aided process management can also easily complete the formulation of man hour quota according to the principle of group technology

Figure 7 process document management module

5 conclusion

computerization of production technology preparation and production management is the trend of modern management development of enterprises, which will enable every engineering and technical personnel to exchange information through computers and realize information resource sharing without going out of the office. At the same time of product design, process personnel can transfer relevant data through computer, participate in product design, coordinate relevant problems in time, and start the preparation of process design. The tooling designer can also manually design the tooling drawing through the computer during the process preparation of the technologist. In this way, the parallel operation of product design, process design and tooling design can be achieved, which breaks the traditional sequential operation mode of the enterprise and improves the production technology to the unprecedented new national standard gb/t 9341 ⑵ 000, which describes the steps of the experiment in detail

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