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1、毕 业 设 计（论 文）英 文 翻 译课题名称顶盖后雨檐冲压工艺分析与拉延模设计系 部材 料 工 程 系姓 名刘鹏专 业材料成型与控制工程班 级T833-2学 号20070330436指导教师签名（校内）指导教师签名（校外） 年 月日Development of a Design Supporting System for Press Die of Automobile PanelsSang-Jun Lee1, Keun-Sang Park2, Jong-Hwa Kim3, and Seoung-Soo Lee31 Dept. of Automobile, Dongeui Institute
2、of Technology, Busan, South Korealeesjdit.ac.kr2 Dept. of Industrial Engineering, Konkuk University, Seoul, South Koreaergparkkonkuk.ac.kr3 CAESIT, Konkuk University, Seoul, South Koreajhkimkonkuk.ac.kr,ssleekonkuk.ac.krAbstract. This paper presents the development of a design supporting system for
3、press die of automobile panels. The proposed system supports the design process of press die efficiently and systematically by utilizing standard data, and reflecting knowledge of press die design collected and accumulated through the interviews with design specialists working in a Korean motor comp
4、any. This paper illustrates a methodology for systematic press die design, automatic checking of dimensions and implementation.In addition the rule-based design system is developed based on the product data. All components of the press die are regarded as product data and the omponents are regarded
5、as the unit of press die. Parametric design using knowledge base and standard database is introduced to make it easier to deal with the complicated design knowledge easily. For implementation, the ule-based design system is programmed with C+ and Motif and the system can be linked with CATIA.1 Intro
6、ductionReducing manufacturing cycle time is an important issue in the recent automobile industry with changing customer needs. Although the industry has adopted various new technologies such as CAD/CAM and factory automation, the results do not meet the expected level. The main reason is that the ne
7、w technologies must be adapted to the industrys own know-how and knowledge workflow, as well as administrative traits of a particular company. 1In designing and manufacturing of trim die and draw die, the variety of car panel shapes and the complexity of the structures complicate the problem even mo
8、re. A lack of consistency in the design may cause weak relationship between the design and manufacturing, and presents difficulties in finding out the errors of designer. Due to these problems, a lot of time and resources are wasted. 1In spite of the variety and the complexity of the car panel struc
9、ture, some consistencies can be found in the rules, knowledge and the methods of design, although they are redundant sometimes. 2-3Hence, it is helpful to develop a design supporting system for trim die and draw die. The design supporting system can be developed by systematically converting the regu
10、lation of the design characteristics and the know-hows of design specialists into the decision rules and knowledge bases. 42 The Current Design ProcessSince the dies are essential tools in manufacturing the body panel of an automobile,the design processes and the process plans of the dies determine
11、the cost, quality,processing time and even the safety factors. 5In the stamping process many kinds of dies such as draw dies, trim dies, flange dies, cam dies, flanking and piercing dies and progressive dies are used. Among them the trim dies are used in the shear forming pressing process which cuts
12、 and removes the panel material by the force of fracture made with cast iron or steel die. 1 The main functions of the trim die are as follows: 1) trimming to cut the boundary of a body panel, 2) removing the scraps, 3) piercing to make holes on a body panel.Until now, these three processes were per
13、formed manually due to the complexity of rules to determine various design variables even if the designers are experts of commercial CAD system. They use approximate work-piece sizes and tentative methods, and relied on past experience to layout the die sets. Also the resulting designs are prone to
14、errors since it is difficult to figure out 3D free surface from the 2D draft and it is very complicated task to calculate the angles of normal and tangent vectors of the trim line and the heights of the inner shapes. To facilitate the die design process and perform the above three processes in a sin
15、gle step a design supporting system is proposed.The draw die process is to force the flat blank into a cavity of the required shape, and at the same time to confine the metal between the drawing surfaces which is forced to change its form from a flat blank to the desired shape. This process is depen
16、dent on the thickness of the metal, depth of the draw, and height of the flange to be formed.Specification of the die for a particular application must be governed by the engineer who has sufficient experience and knowledge about the operation and construction of the various die shapes. In the desig
17、ning process of draw dies, the designer examines whether the panel geometry data has defects or not. If there is a defect, it should be rearranged. After this process, the designer points out the punch profile and blank curve among the surfaces and curves which consists the geometry of the panel.The
18、 first step is to determine die face, offset line, design of wear plate, block lifter and gauge. Next important step is to determine the size and layout of die set. 1 Finally, several components such as balance block, cushion pin, and rib, etc. are designed.3 Development of Design Supporting System
19、for Press DieIn developing the design supporting system the following criteria must be satisfied. First, the design process should be carried out according to the standardized design work flow. Second, the design variables are determined by the rules of design processes. Third, the complex geometry
20、can be checked automatically.For embodiment, the design rule base is programmed using CATGEO, CATMSP in the CATIA version 4.2.1. 13 The program is developed on IBM RS/6000 with C+ and IUA for GUI. The design rules and knowledge are collected by the interviews of design specialists in the press engin
21、eering department of H Motor Company.The configuration of the system is presented in Figure 1.3.1 The Structure of the Design Supporting System for Press DieThe design supporting system for trim die and draw die design consists of the user interface module, the design process module, and the rule-ba
22、se module. The user interface module helps users to design the press die easier and faster. The design process module controls the input data and the data generated at a design stage so that they can be stored or retrieved systematically. The rule-base module helps representing the know-how of desig
23、n specialists and design rules of the automotive industry. The structure of the developed system is shown in Figure 2. 6The proposed system enables the design process to be dialogical one and checks the errors in user input to prevent a failed design. Hence, the system can be used as an error checki
24、ng tool as well as design tool.3.2 Representation of the Design RulesWhen designing a panel with prismatic shapes and complicated structure, the resulting design tends to be different from the original design or even faulty even if the same design conditions and design processes are applied. However
25、, no one can clear out the reason due to the inherent complexity of design rules and structure. 6-7 Therefore, it is important to establish robust design system which can give us consistent results especially when designing and manufacturing complex products.To establish robust design system it is n
26、ecessary to standardize the design process by extracting the design methods and rules through the careful analysis of design processes and variety of special features included in the design process. 8In developing the press die design system, the design processes and the design rules are standardize
27、d by gathering information and know-how from the specialists and then storing them in a database to retrieve the information whenever necessary. 4 The design rules are implemented in three groups:1) Historic Rule: general design knowledge, features of design method for each component, selection of d
28、ie type, selection of material for each component accordingto the shapes, maximum (or minimum) size of each component, location of each block, bolt location and the number of jig parts in each component, positioning dimension, the number and designing position of reinforcing rigs, etc.2) Heuristic R
29、ule: includes design method and know-how of the design specialists, location of each component in trim line and draw die shape, position decision factor, prohibition section of component separation, machining margin, method of pierce separating, width margin of scrap cutter, location of block, etc.3
30、) Procedure Rule: calculation of dimension according to the design formulation, design rule, mutual relation between the components height and width, separation length between each component, calculation of height between each component, etc.The proposed design system has many advantages: The design
31、er dependency can be reduced by saving the special know-how and experiences related to the design. The new design of an object is corresponded quickly by storing the past design rules in the rule base. 9 Also, modification and maintenance can be done easily.3.3 The Process of Design Shape in Trim Di
32、e DesignTo design a block in the quadratic domain the position and dimension of the block are determined by the face surface of the product included in the block feature using the enumerating method implemented in the design rule base.The dimension of a block is determined in the sequence of width,
33、height, and length after the designer sets the check gap of height in the shape.When the designer decides the trim line and the start point, the positions of the blocks and the block widths are determined first. The positions and widths of the blocks can be calculated by dividing the trim line into
34、equal parts by the check intervals determined with several rules. Then the block heights bounded by the maximum heights (obtained by the shape checking routine) are calculated so as to minimize the machining volumes. Finally, the length of the block is determined using the width and the height of ea
35、ch block considering the size tolerance and weight of each block.The system stores shapes and parameters of the resulting design as a feature information in the database so that the system can extract those information in case of designing a trim die with similar shapes and parameters. 10-113.4 The
36、Process of Design Shape in Draw Die DesignThe next step is to arrange the block using grid line in 2D according to the design rules as mentioned before, and to select rule-base data management method in order to decide the draw die type by die size and body panel shape.There are four major functions
37、 in draw die design system. They are 1) selection of components and their dimension and shapes from standard database, 2) determination of layout position, 3) construction of the relations among the components and geometries, and 4) modification of the parts and die size from the past design. These
38、programs cover four different types of draw dies; three single action type (transfer, tandem, and cross bar) and one double action type.Before deciding the height of components feature, user must decide shape checking interval of draw die in the product surface feature and divide surface shape and h
39、eight of draw die according to the selected checking interval. Positioning of each component is decided by this divided point and an intersecting point on 2-dimensional die shape.The feature information of each components generated as a result of design and design parameters are stored in database a
40、nd the system can retrieve the data in case of designing draw die with similar features and parameters to save time repeating the same design work. 10-113.5 Display of Design InformationThe proposed system controls product design process in a viewpoint of design administrator and provide 2D user-int
41、erface to support the detailed concept design with automatic 3D component calculation. Moreover, the system can provide user-friendly interface with graphics and charts and check design error caused by blunders in design step.The system shows the design rules and design methods on the system-display
42、 panel and they can be corrected automatically using the built-in tool which can induce design data control module with design-object, design process and user-interface. 10-11Also the shape and size of the designed block are illustrated as a 3D shape with the material table that includes all the nec
43、essary information in the design and production step so that the design results can be passed directly to the production step.4 An ExampleIn this section, an example is presented to demonstrate the effectiveness of the “Design supporting system for press die” using the solid model of a panel in CATI
44、A Fig. 3. The shape of Quarter outer panel as input modelFig. 4. Height definition of panel using “CHECK” menu Fig. 5. 2D shape of designed trimming block Fig. 6. 3D solid shape of designed trimming blockenvironment. 13-15 The selected model is the quarter outer panel of an automobile,which is desig
45、ned and produced at the H motor company.The feature windows displayed during the execution of the proposed system are illustrated in Figure 3 through Figure 6. Also the materials table created after the final design is shown in Table 1. The materials table is automatically created with the name of “
46、PARTLIST”.The design of draw die includes a lot of variables depending on the design conditions and much of the design process is not standardized yet. This makes the designer to select a particular method in the design process sometimes.Figure 7 shows the feature windows, showing automated executio
47、n of draw die design with double action among the press die design process. Table 1. Part-list output of designed trimming blockFig. 7. Top view of drawing for upper die using double action5 ConclusionIn this paper, a design supporting system for press die is developed. The main featuresof the devel
48、oped system are as follows:1) The number of errors due to the complexity of geometry can be reduced and prevented. Also design accuracy is improved by managing geometrical data mathematically.2) The feature information of a design can be used as manufacturing information such as orders for raw materials. This can shorten the time for designing and manufacturing.3) Beginners can design dies by modifying the design rules and the design knowledge standardizes simple operations and the design process for the specialists. Furthermore, a domestic design syst
