Development and application of the latest train bo

The development and application of body process template

the competition in the domestic and foreign automobile market is fierce, and the speed of product upgrading is faster and faster. All manufacturers prefer to change the body assembly as the embodiment of automotive product upgrading, but the development cycle of new body is long, so shortening the development time of body assembly has become the goal of major companies

the new body product development mainly includes four stages: product planning and definition, product design (conceptual design and engineering design), product verification and production preparation (see Figure 1). The whole product development must be carried out in accordance with the enterprise design standards, processes and experience, with reference to the existing model data and the target sample vehicle structure. Because the same structure, the same section and parts, the same design methods, design rules and design standards are applied in each development, there is a lot of repetitive work in the whole product development of the body. For example, for each vehicle model, ergonomic analysis and layout must be carried out, and the ergonomic layout of the newly developed series cab requires more than 10 design repairs from product planning definition to product design completion, which has unique industrial advantages. Every scheme modification is a repetitive work, which consumes a lot of design time. Therefore, how to avoid repetitive work and shorten the product development cycle has become the primary problem

Figure 1 body product development process

in addition, in the body product development, talents also play a vital role in the cycle and quality of product development. However, the phenomenon of talent flow of automobile design experts is relatively serious, and how to stabilize these talents is also a problem that all enterprises need to consider at present

CATIA software is commonly used in the development of car body products. With the use and development of CATIA, many new product development methods combined with CATIA software have appeared abroad, such as DMU technology, template technology, correlation design method, etc. Among them, template technology can not only avoid the repetitive work of design and shorten the development cycle of products, but also realize the knowledge accumulation of enterprises. Major foreign automobile enterprises and design companies use this technology in product design and development

introduction to template technology

template technology refers to using design software as a carrier to it the geometric features, typical structures, typical sections, typical parts, assemblies, design methods, design rules and design standards frequently used in product development and design, forming a separate and repeatable use library or module file. The template technology based on CATIA V5 software usually uses KBE (knowledge based Engineering) technology provided by the knowledge engineering module in CATIA V5 software. KBE is a knowledge-based engineering system, which defines the product design method and design process by capturing the knowledge in the design scheme and design process, adopts the knowledge drive to form an interactive interface, and provides the designer with a reasonable design solution. Therefore, through KBE technology, knowledge is captured and formalized, and designers make full use of the existing knowledge of experts and enterprises, enterprise standards and international regulations in product design, so as to achieve the best design effect

templates are divided into feature templates, part templates, assembly templates and process templates according to different it content. Assembly templates and process templates have high requirements for the development ability of enterprises. Enterprises themselves must have the ability of independent development, and the product development process, scale, standardization and standardization. The body Department of FAW Technology Center currently defines some feature templates, as shown in Figure 2

Figure 2 the body Department of FAW Technology Center currently defines some feature templates

major foreign auto manufacturers have already developed their own templates, and the number of various templates ranges from more than 100 to thousands, which have been applied to product development and design, and achieved good results. Since 2005, FAW technology center, in cooperation with Dassault and Xunli, has started to define and develop body design templates by drawing on foreign experience and combining the development characteristics of body products in its department. At present, the customization of feature templates, part templates and process templates has been completed and applied to the development of commercial vehicle body products

development and use of process template

the body Department of the technology center has developed the ergonomic design process template and the wiper system verification process template based on CATIA V5 R15 version. These two process templates make SAE standards, enterprise standards and expert knowledge it, and provide beneficial help for ergonomic design and verification. See Figure 3 for ergonomic design process template and output report

Figure 3 ergonomic design process template output report

next, the author takes the wiper system verification process template as an example to introduce the development and use of the template of more than 23000 process personnel

wiper system verification refers to the process of calculating the theoretical windshield areas a, B, C and the actual windshield areas a, B, C according to the known ergonomic parameters, geometric elements and regulations in the early scheme layout development stage of the car body or other product development stages, and then determining and verifying the wiping rate (the wiping rate is the ratio of the actual a, B, C wiping area to the corresponding theoretical a, B, C wiping area). At present, the main regulation used by the body Department of the technical center is SAE j198 windshield wiper systems trucks, buses, and multiple vehicles. The verification process template of wiper system makes the above process it and forms a proprietary design module

the development process of the wiper system verification process template is to first establish the geometric modeling of the wiper system by using the part design and gene in CATIA V5 R15 software, which have a non sticky feel and a weight reduction of 65% tive shape design module. The three theoretical wiper areas a, B and C are based on the angle values given in SAE j198 regulations (see Figure 4), Make the 95th percentile SAE eye ellipse upper and lower tangent planes (straight line in the side view) and left and right tangent planes (straight line in the top view) respectively. These four tangent planes intersect with the windshield to obtain four intersecting lines. The part of the surface on the glass surrounded by the intersecting lines is the theoretical scratch area. If the intersection line exceeds the glass boundary line, or the intersection line with the glass is less than 25mm from the glass boundary (DLO), the area 25mm inward from the glass boundary (DLO) shall prevail; The actual wiper area is to determine the actual wiper area of the windshield according to the known parameters such as the size of the wiper, the center position of the wiper arm, the direction of the windshield and the wiper shaft

Figure 4 SAE j198 stipulates that the geometric model established above classified vehicle models must use knowledge engineering modules (parameters, formulas, VBScript, etc.), and the model must have correlation and parameterization characteristics

according to the established geometric model, use powercopy or UDF technology to establish small templates. The number of templates is determined by the geometric complexity of the model and the specific design process. A total of 5 small templates are established in the wiper system verification process template

according to the small template that has been created, the designer builds a knowledge driven interactive interface under the environment provided in the BKT module, and finally completes the creation of the process template

the use process of the wiper system process template is divided into seven steps, mainly including importing the geometric conditions required for modeling, establishing empty design part documents, creating theoretical windshield a, B, C areas, creating actual windshield a, B, C areas, checking and analyzing, optimizing parameters and output result reports. See Fig. 5 and 6 for the optimization analysis of the wiper system check process template and the program tips of the check process template

Figure 5 optimization analysis of wiper system verification process template

Figure 6 program prompt of wiper system verification process template

when the wiper system verification process template creates theoretical areas a, B and C, the input conditions include windshield surface, eye ellipse center point, body absolute coordinate plane, vehicle types classified by purpose (SAE j198), etc. The wiper system process template includes all SAE specified vehicle types; When creating the actual zones A, B and C, input the conditions: the fixed point of the wiper, the windshield surface, the initial position of the wiper blade, the length of the wiper blade and the rotation mode of the wiper arm. This model can check the forward swing and opposite swing of the wiper system

if the analysis results of the wiper system verification process template cannot meet the requirements, the template will provide two ways to optimize the analysis, one is to change the length of the wiper arm to optimize the actual wiping area; One is to change the location of wiper layout points to optimize the actual wiping area. Provide solutions for designers in these two ways. Therefore, the template can be used not only for the verification of later products, but also for the preliminary scheme design

after optimization, if the scraped areas of areas a, B and C meet SAE standards, the program prompts the designer to generate the verification report. The report results are shown in Figure 7

Figure 7 output report of wiper system verification process template

conclusion

FAW Technology Center customized two process templates through cooperation with Dassault and Xunli. After that, designers no longer need to carry out repetitive work in ergonomic design and analysis, which improves the efficiency of product development and shortens the product development cycle. The use of process template also promotes and deepens the process, standardization and standardization of the body design and development of the enterprise, and also realizes the knowledge accumulation of the enterprise. (end)