Development and implementation of digital virtual

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Development and implementation of digital virtual manufacturing technology for body in white equipment for a long time, the manufacturing of automotive body process equipment in China has been completed by human experience and mechanical drawing. Since the development of computer aided design/manufacturing (cad/cam) technology in the 1980s, this technology has been widely recognized and has shown great advantages in practical production at a rapid development speed. Computer aided engineering analysis (CAE), which began to develop in the 1990s, has been widely used in the field of automobile die formability analysis

since the combination of computer (digital) technology and traditional car body process equipment manufacturing industry, China's car body process equipment manufacturing industry has developed rapidly in just over 20 years. With the attention and investment of enterprises in computing technology, the average computer ownership, broadband access, network construction, database (especially product/technology database) construction and various business application systems construction of China's body equipment manufacturing industry have been higher than the average development level of other industries. Some large-scale body equipment manufacturing enterprises in China have reached the advanced level of software/hardware, even exceeding the international advanced level

however, large quantity does not mean powerful. Advanced software/hardware does not mean advanced technology. Looking at the application status of digital technology in China's well-developed body equipment manufacturing enterprises, it is not difficult to find that formability analysis, three-dimensional solid design of tooling product structure and three-dimensional numerical control programming account for more than 90% of digital applications, and welding process planning, testing and debugging still remain in the traditional production mode. The imbalance of technology leads to the unsmooth connection between processes, and it is difficult for digital technology and simulation technology to play an integral role, which has become the bottleneck for the further development of digital virtual manufacturing of body equipment in China

virtual manufacturing is to use information technology, simulation technology, computer technology, etc. to comprehensively simulate people, objects, information and manufacturing process in real manufacturing activities, so as to find possible problems in manufacturing, and take preventive measures before the actual production of products, so as to ensure that products can be successfully manufactured at one time. In virtual manufacturing, the whole production cycle of products from initial shape design, production process modeling, simulation processing, model assembly to inspection is simulated and simulated on the computer, and there is no need to actually produce products to test the rationality of the design. In this way, it can reduce the trouble caused by the early design to the later processing and manufacturing, and avoid the occurrence of scrap, so as to achieve the purpose of improving the primary yield of product development, shortening the product development cycle and reducing the manufacturing cost of the enterprise

the development of domestic BIW equipment digital virtual manufacturing

China's automotive equipment industry still needs a process of in-depth application and innovation to achieve real virtual manufacturing

1. The application of the existing cae/cad/cam technology needs to be further deepened

at present, the stamping process analysis (CAE) of the die has not formed a unified and standard specification in the pre-processing and post-processing. The use of the software can be said to vary from person to person and from company to company. Therefore, there must be some differences in the evaluation of the analysis results. In addition, the job responsibilities are not detailed enough to cultivate expert talents for CAE analysis. DL designers carry out process evaluation of products, prediction of process schemes, formulation of process schemes, feasibility analysis of process schemes, etc. the application of CAE is always in a general basic application state. At present, CAE is mainly applied to the feasibility analysis of drawing forming, and there is little work on the optimization of trimming line, the feasibility of flanging forming, and the prediction and compensation analysis of springback distortion. That is, improving standardization and specialization and expanding the application of backward processes are the contents that need to be further deepened

in terms of structural design (CAD), in addition to further improving and popularizing the existing entity design specifications, it is also necessary to continuously expand the entity resource library, including mold press library, standard parts library, typical structure library, plant resource library, etc. Moreover, knowledge engineering technology is a favorable tool to improve design efficiency and quality. Enterprises should actively transform design experience into reusable mathematical models, so as to play its role in guiding and standardizing design

the domestic development of cam is very close to that of foreign countries. It is not inferior in terms of numerical control equipment and programming ability, but there is a big gap in processing data. There may be great differences between the machining digital simulation of the die surface and the product digital simulation. The manufacturing of the die surface for machining needs to accumulate a lot of practical experience and follow the corresponding criteria. The preparation of such criteria requires a considerable understanding of the product matching relationship and the welding of the whole vehicle, and even a sufficient grasp of the body in white design. We still need long-term summary and accumulation for the production of this fine mold surface

in addition, foreign countries have adopted the practice of direct programming of entity data, which has high programming efficiency and good effect. However, due to its high requirements for product data quality, it also requires that the product version must be relatively stable, otherwise the workload of data modification will be large and difficult to maintain. All these put forward higher requirements for domestic main engine manufacturers

2. Establish a perfect simulation system

establish a perfect simulation system based on the existing digital platform, give full play to the advantages of digital technology, find possible problems in manufacturing at the design stage, take preventive measures before actual production, and improve the success rate of one-time commissioning

(1) mold simulation

· realize the motion simulation analysis of mold, progressive mold, large mold stamping line, pressing mold and complex mold. At present, the structure of the car body mold tends to be more and more complex and compact. It is difficult to detect the problems in motion by using the design verification methods such as human visual judgment and section observation in the three-dimensional environment. In analyzing whether mechanical handling is smooth and interference free, and whether manual handling is safe and convenient, it is more necessary to carry out simulation. In addition, in order to improve the efficiency of motion simulation, the motion scenes of typical mechanisms should be established, such as the typical motion of handling mechanism, press mechanism and wedge

· realize numerical control machining simulation, effectively prevent the collision of machining tools, optimize cutting path and improve machining efficiency

· use the white light scanning equipment to collect the die surface data after numerical control processing, virtual die closing in the computer, find and deal with the possible problems in debugging in advance, and improve the efficiency of actual die research and maintenance. It can also compare and analyze the die surface data after fitter debugging with CAE simulation results to accumulate stamping process design experience

(2) welding tooling simulation

· realize the simulation of the overall process planning of the welding assembly line. Use the pre-defined welding process planning template, import the product tree diagram, and then carry out the actual welding process planning. During the planning process, various welding resources such as welding plant structure, process tempo, fixture layout, process logistics, welding equipment and other factors should be considered at the same time, so as to form a "real" welding process flow in the computer. The production capacity of the welding production line is balanced and analyzed, and the process allocation, solder joint allocation, station number, personnel allocation, tooling automation and other contents of the product are continuously optimized

· in terms of structural materials, realize the assembly sequence simulation of welding products at stations (including the process of product loading and unloading), the mutual matching simulation of resources at each station, the time sequence analysis and simulation verification of welding line and fixture stations, and the simulation verification of welding tongs

· realize man-machine engineering simulation, robot welding assembly process simulation, mechanism motion simulation and the establishment of three-dimensional factory

it is quite difficult to realize the above contents, and professional talents are required. The amount of data in large stamping lines and welding plants is very large. The existing computer hardware level is sometimes difficult to meet the simultaneous simulation of a large number of complex movements. It is necessary to study the data lightweight design means and step-by-step simulation. In addition, because this part of functions involves the whole process of body equipment design and manufacturing, the software platform at each business stage is not unified. How to ensure the complete transmission and inheritance of data and information from the previous and next processes often requires detailed planning and software secondary development

3. Exploring and applying international cutting-edge simulation technology to achieve accurate control and optimization of design

vr (virtual reality) is a new way for people to visually operate and interact with complex data through computers, and reproduce the computer's three-dimensional data space through large-scale three-dimensional projection equipment. Compared with the traditional man-machine interface and popular windows operation, virtual reality has made a qualitative leap in technology and thought. Virtual reality has the characteristics of multi sensing, immersion, interactivity and imagination. So that the operator can really enter an interactive 3D virtual environment generated by the computer, interact with it and communicate with it

desktop virtual effect can be realized by using 3D simulation software and PC workstation. The operator can sit in front of the computer monitor to observe the virtual realm of 360 degrees, and use the mouse, trackball and other control terminals to change the viewing angle. However, operators and other participants are not fully involved in the virtual scene. In order to form this "real" sense of engagement, we must use the input virtual device

this technology is used to conduct virtual simulation on die stamping line, typical die, NC machining process, virtual mold closing process, large welding line planning, detailed process content, robot action, plant construction and other contents, giving full play to the characteristics of the input virtual reality system:

immersion (presence): refers to the degree to which users feel that they are the protagonists in the simulation environment. The ideal simulation environment should make it difficult for users to distinguish between true and false, and make users devote themselves to the three-dimensional virtual environment created by the computer

interactivity: refers to the user's operability of objects in the simulated environment and the natural degree (including real-time) of getting feedback from the environment, or deformation will occur under the action of gravity

conceivability: it is emphasized that virtual reality technology should have a broad imaginable space, which can broaden the scope of human cognition. It can not only reproduce the real environment, but also freely conceive the objective non-existent or even impossible environment

through such input virtual reality technology, what is realized is no longer the basic functions of simple three-dimensional observation such as motion simulation and interference inspection, but to create the feeling of being born in its environment, inspire the creative thinking of designers, and provide a broad space environment and realistic sense of scene for many non operators to stop the technical discussion, technical planning and approval of start-up operators

analysis of stamping line motion

introduction and application experience of new technology

virtual manufacturing technology is a new technology for many enterprises, and its application is still a subject that enterprises need to face. As an entity directly facing the market, the enterprise is the most pragmatic. The research, development and introduction of any technology must finally be implemented into the actual production before it is meaningful

apply a technology well

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