1734_吊耳加強板零件沖壓工藝與沖模設(shè)計
1734_吊耳加強板零件沖壓工藝與沖模設(shè)計,加強,零件,沖壓,工藝,沖模,設(shè)計
1Intelligent stamping process planning system research Abstract: this paper to build a intelligent stamping process design knowledge based system gives a brief introduction. Study the system framework of model, and knowledge reasoning model are introduced. For some key technologies such as the feasibility of stamping process and exhaust kind of best algorithm, intelligent zone layout and internal force calculation is studied. This system can improve process planning efficiency. Keywords: arrangement a KBS knowledge model ribbon arrangement method introduction Stamping process planning is one of the core punching product development project. It is the metal molding application an important component part of it and the production quality, cost, productivity and tool life have direct influence. The rapid development of modern manufacturing for stamping put forward higher request, especially in stamping process. For many years, the related research has the environment in innovation to strengthen the integration and process planning study intelligentize degree. In recent years, through the production of metal forming intelligent design system, automation technology, the whole and the process planning principles. Intelligent process planning method can effectively improve the design efficiency and quality, innovative design ability. [1]. For cold forging sequence of designing and developing a kind of expert system based on PC, this system based on practical considerations plasticity theory and the rules. At the Ohio state university, a called FORMEX rules system is Altan and his colleagues write multistage cold forging process planning and programming language. [2]. It depends on a cold forging parts of various shapes widely classification. [3] implement knowledge based cold forming sequence design system, adopting the design rule sure to establish a feasible sequence, then using finite element analysis optimization this sequence. A knowledge based mold design automation system is Cheok and his colleagues carefully designed. [4] in the national university of Singapore. Some parts representation techniques, stamping parts recognition and mould constitute also exists in this work. In China, huazhong university of science and technology researchers also developed based on knowledge system for small metal parts stamping progressive die program packages. [5]. Use features, users can under 3D architecture design products. In manually set arrangement, user can use interactive command to development zones outfit layout design. From Liverpool university industrial research department's researchers are also studying stamping process and punch die special system. [6]. The focus of their study in decomposed smaller bridge waste shape coding and recognition 2technology. [7] in Shanghai stamping mould and tools institute of technology researchers also developed progressive die CAD/CAM system. They study the system depend on special relevant data to describe the workpiece and mould structure. The findings of the research work purpose is to promote the development of metal forming process. From metal intelligence review and analysis of the forming of intelligent design, use the theory and method to study the stamping process planning steps. In this paper introduces applied in stamping process planning of intelligent system. This intelligent system in dealing with some complex design problem is a powerful tool. By special knowledge construction intelligent systems can use an interactive way help user to solve all kinds of problems or questions. [8]. Intelligent system is a computer system, it tried to represent human knowledge and professional knowledge, and to a practical and effective way to provide fast, convenient and knowledge. Intelligent system can accomplish generally require experts to complete tasks. It can automatic real-time use existing professional knowledge, and explain its reasoning process. Stamping process planning is a rich knowledge of the complex design process. Integration in the stamping process planning and design of the key techniques of intelligent system is of vital importance. The use of intelligence theory stamping process planning intelligent systems have been proffered. Some key technologies, such as integrated product knowledge modeling and strategic planning comprehensive stamping process was studied. In stamping design including all kinds of knowledge, such as domain knowledge, multitasking knowledge, non-standard knowledge. Each kind of knowledge all need to be integrated into the system. Stamping mould that is the core of stamping process. Must consider the various factors, such as geometry, technical requirements, material properties and stamping feasibility, working procedures arrangement, the structure of mould tool. Stamping process planning is a kind of creative program based on experts' knowledge. Intelligent system technology can improve the efficiency of the stamping process planning. 2 system frame and the frame Intelligent system key technology is built and application of information model making. This product information model, including three stages: a kind of the model, based on geometric model based on features based on intelligence, the model. Based on geometric model describing the geometric topology information parts. Because parts of data message cannot be fully described, data separation level is too low, geometric model was characteristic model replaced. This information model includes a set of geometric entities. Rely on this model, the engineering semantic model with design of related functions many can be realized. Along with the development of artificial intelligence, the intelligent model begins to be used. 3Professional knowledge, design process of knowledge, and relevant knowledge are included in the knowledge model [9, 10]. Intelligent model support expression and transfer of useful information. This paper mainly summarizes a stamping process planning of intelligent system. This intelligent system for product definition effective and complete. It has the advantages of different geometrical model and can satisfy the geometric designs and reasoning process. Object-oriented technology is applied to integrate all kinds of knowledge. This integrated knowledge system model can be Shared and used in intelligent design and product information communication. Figure 1 shows the stamping process planning intelligent system frame This about stamping mould process planning of intelligent system frame has been designed. The components of the structure design, including a graphical user interface, an application system, design resources, knowledge tool, mixed reasoning mechanism, basic model. In this architecture knowledge model have different classification. Knowledge model from the design resource to extract useful information, support knowledge acquisition and knowledge expression program. This model is useful information transferred to knowledge. Comprising CAD software support. Design results as a 3D model, pictures and database is stored in the repository, it in different parts of the knowledge base is very important knowledge transfer. 3 implementation method and application 3.1 stamping feasibility of intelligent model Intelligent system for stamping workpiece quality, cost, die life is evaluated. This evaluation based on mature intelligent model. This model has integrated rule library, parts information and conclusion library. Coefficient of knowledge rule reasoning in knowledge according to that. Stamping forming feasibility can from a database of information and related coefficient parts launch. In the design process of the extension of the new conclusion preserved in conclusion library. Model of intelligent reasoning process and parts specification limits range compared with the technological parameters. This specification Including input/output radius, aperture, orifice plate, hole nets, chamfer, trough nets. Results to confirm whether accord with the shape of mould parts processing tools. Intelligent reasoning is used in the automatic and interactive way. It's purpose is to study the feasibility of pressing the product. Intelligent reasoning based on the key is to determine the thickness and the correlation coefficient parts processing limit. Figure 2 shows the feasibility of the 4model for product flow chart. Figure 2 shows the feasibility of the model for product flow chart. Knowledge rules and design results stored in the database of mechanical reasoning. Parts in knowledge model shape can modify. The decision by the knowledge model stamping process planning is very important step, it also provides to choose a single step process tool or composite tools or a method of improvement tools. All sorts of different domain knowledge, experience and expertise are kept in the process planning of professional system. Based on the development of knowledge base is the common principle rules expression. The purpose of this step is to integrate professional experience and parts shape 3.2 based on optimization algorithm of intelligent strip layout model In order to achieve higher material utilization, blank knowledge model was established, the results are stored in knowledge base established basis other modules. In the knowledge base there are four arrangement type: Arranged layout pattern determined With an array of Washington relative pattern Second-ranking arranged layout mode two With two second-ranking arranged layout relative mode The purpose of establishing the knowledge model is to improve the material utilization. The restrictions by knowledge can provide human experts to choose from. This knowledge model control over the whole arrangement design process. Figure 3 shows the layout rating system structure The first kind of mode selection function is roughly calculated the numerical and working area general outline. This model provides the original parameters. All the information is roughly value resulting from them, no matter the figures are outlined draw or selected. The second mode used to determine the layout type, Angle range, layout size and strip the width. The third kind of mode applied optimization algorithm. Design results include material utilization, material width and every step clearance are kept in this mode, the different layout drawing also generate. In the fourth mode can modify layout results. Eventually parameters include clearance, material each step of grid, and the width, the ability to switch. When the parameters change, 5layout plans can be updated. This knowledge is the main purpose of the algorithm to optimize the layout planning. This algorithm six steps. 1. The most suitable around in graphics rectangular first generation. The original copy and the distance between the approach is included in the net. Figure 4 shows the algorithm. 2. The value of the two ring is among a computation. The two ring is decomposed into line and arc units. The distance between each element needs to compensation. And then you can find the shortest distance. 3. The minimum value and calculated the value of the required the difference between is error. When the error less than value, arrangement planning can be completed. In addition, graphic layout to follow the direction of the view movement. Graph 4: arrangement algorithm. A primitive Angle graphics. B rotation Angle of graphics after 4. Material utilization in layout's point of view is calculated. 5. Arrangement graphics rotating certain Angle. Rotating center near the center is the rectangular roughly value. Material utilization in the current Angle was calculated. 6. Arrangement graphics rotated to another Angle. Repeat the steps of the third part, until Angle reached 180 degrees. Figure 5 shows is the arrangement design results. Graph 5: row kind of intelligent design results. The development of 3.3 ribbon layout The layout of the shingles rule was integration process in knowledge base level into tool design. This intelligent model function is: select parts location, design azimuth and arrange ribbon work step distance. In order to solve the operational procedures, and the rules should be reasonable and effective formulated. Automatic design module is intelligent model in the most important modules. Artificial intelligence technology has been applied in this module. This model, including the pretreatment module orientating products module and extracted from the product modularization accurate information. In order to modify module generates a model, initial design engineering is modified [11]. The modified module instead of processing module. Figure 6 shows the layout of the model and the algorithm for shingles. 3.3.1 automatic ribbon layout design preprocessing 1) determine the position and permutations. Parts The user can use interface to determine some of the preconditioning module parameter. The process can determine the position and 6other elements, such as: to do together shape and size accuracy, parts and user requirements. Parts in the shape of the intelligent model definition, the results are stored in a knowledge base. 2) get parts precise information. The precise information should get in ribbon layout knowledge base. Useful information including punching accurate information and relative location information. This type of knowledge model of information will decide parts stamping sequence. The design process is the main requirements for the position precision to develop a knowledge model [12]. First, the shape of the parts were divided into closed contour. Outline the number of n K = {k1, k2,..., ki,..., kn} (1) Here the first I ki says parts an outline. The relative relations between all contour contained in the relationship of P. If in contour kj ki and precision, there exists between requirements ki, kj) ∈ (p. P = {...., (ki, kj),...} ki, kj ∈ K, 1 acuities were I, j acuities n (I _ = j). (2) The position precision from P get relevant matrix is: (3) Each type of accurate information through the correlation matrices is preserved in knowledge model. 3.3.2 ribbon layout automatic design Ribbon automatic placement design module in the knowledge model is the most important one. In the knowledge model contains a lot of important rules, for example in a single stroke in stamping all the inner contour is better. In the next stage of this section was cut off. Sometimes, if the distance between the stamping point within is very small, some will be moved to outline a stage for machining. If stamping point too close from fractionation point fractionation point, if will need to be changed to the next stage. If there are still not the right size and some point can be moved to the next stage. Repeat the process until matrix of every size between points can be accepted. Intelligent design is the core of the layout of the intelligent model development interference point. [13] Parts were divided into many point blank form. These point name is k1, k2,..., dij kn. Here Kj ki and is the smallest distance between. Matrix critical value is S. If dij < S, ki and kj Can't draw in the same steps. This kind of situation is intelligent model of the conflict between two points. Development of the intelligent model interference point ChongTuDian aim was to determine the existence. This matrix is a system matrix. In order to make the 7design process is more convenient, can put the matrix of half part element zeros. Here, mu ij correlation coefficient, which it says is for every to point between different relations. If there is a contradiction between two points, one of them is to be moved to the next step. In every step of ChongTuDian disappear until repeat this step. Finally matrix M become empty matrix. The shingles layout of 3.3.3 trace process The layout of the shingles son two of handling knowledge model: change results and create part graphic layout. Automatic design model from ribbon layout draw result is staple. They may can't satisfy the users of all the requirements. Depended on the knowledge model data structures, by moving point and change steps, increase steps and deletes empty empty the purpose can be realized step. We can pass the data processing steps to revise the ribbon of the layout design results. Step change can work through exchange of coding to realize two positions, work step increase or decrease can insert or removed by the operation to complete. Code When we want to move some point, we can from the first step to the last step transfer list is points. Figure 7. Shows is the ribbon automatic placement design result [11]. Figure 7: ribbon automatic placement design result 3.4 sure stamping center and force calculation of intelligent model. Press center design model establishment is the purpose of the group operates [11] together. Mould tool center and stamping center's consistent is very important, only as stamping tools can together the normal work. Press center from the knowledge model calculation of every contour position in conclusion. Design is to get the first part of the tools work area. CAD platform of parts provided parts of graphic outline the rectangle. Rely on stamping center and the relationship between the rectangular can generate work area. Because of the result of unbalanced force is the possibility, it also offers stamping center regeneration into. Regeneration by human-machine interface into steps to complete. Software Figure 8 shows as the composite modulus stiletto mechanic for design of area results. Stored in the repository includes every type of mould tool parts blanking, waste removal, etc. Different situations force calculation method is different. By force equations is obtained knowledge rules, the reasoning of the library. First, processing power and cutting force is based on parts of the contour length and knowledge base knowledge rules get. Then, through the design results, can get harmony parts from force, resistance and push a force. Total force the guide according to knowledge step by step calculation. Figure 8: composite modulus punching machine work area. 84 conclusion and further work The application of computer aided design tools in the application of metal forming, save a lot of time and money. Due to complex parts the complexity of stamping process design to develop a system of automatic generation process step is very important. This study developed an integrated CAD system, this system developed a process planning system makes for an irregular parts in high speed into precision processing can be realized. The system has the features: 1. In the design process changing data in different ways to save, including digital form and picture form. Users in the design process can freely use them as reference. 2. Check the model check processing feasibility, the feasibility of can also pressing for complex parts stamping process planning with some Suggestions. 3. Arrangement module generating optimal arrangement graph the biggest arrived on the material utilization. The product cost reduction depends on the strip layout optimization calculation. Not only the best planning and every reasonable planning are stored in a knowledge base. Users can choose any one as their final design results. 4. Ribbon arrangement module automated process plan. According to the requirements of customers, the results can be ribbons in the strip layout design process of any period modification. In process planning of this system in assist designer will be a useful tool. It will be enough flexibility allows designers creative, at the same time use the computer to execute geometry calculation and automatic get design results. It provides a very flexible design environment, users can complete mastery of even complex parts stamping process planning and design. This system has a graphical interface, user can in the design process of design parameters geometrial change. Further
收藏