Parametric Design And Optimum Design Of The Industrial Sewing Machine Casing

In recent years, the domestic sewing machinery industry take the innovation as the main line to promote enterprise transformation and upgrading, automatic numerical control technology and information technology develop new market with its intelligent and efficient, saving labor, the rapid market reaction and other comprehensive performance. Under the background of Shaanxi Province CNC mechanical product innovation generation demonstration project, the shape dimensions and the local features of the casing parts are designed, the parameters of the parts are designed, and the finite element analysis and optimization of the casing are studied by taking the casing of industrial sewing machine as the research object in this paper. The specific work is carried out in the following four aspects:(1)The design of the casing is completed according to the similarity principle, the design principle of the shape elements and the mechanical design standard. The ratio of each dimension of the casing and the shape elements of each part are determined. The design of the wall thickness, the strengthening rib, the hole, the convex table and the other local features are determined.(2)The three-dimensional parameterized model of the casing of high-speed sewing machine is established by using 3D drawing software Solidworks. Based on the VB programming language, the secondary development of SolidWorks and the design of user interface embedded in the database of the casing and the bottom plate are realized, which achieves the visualization of casing module through bringing the API function of SolidWorks.(3)The 3D solid model is simplified, and the model is imported into Workbench by using the special interface of ANSYS Workbench and SolidWorks. The displacement distribution contour, stress distribution contour, first six order modals and relative natural frequency are given by using the Workbench to do the static analysis and dynamic analysis of the casing, providing basis and design ideas to optimize the structure of the casing.(4)Taking the first natural frequency of the body away from the sewing machine maximum working frequency as the optimization target, and combining APDL language and Workbench optimization module to optimize a group of thickness parameters sensitive to body mass. Under the condition of smaller reducing the performance of sewing machine, the best combination of casing thickness and bottom plate thickness is obtained by software simulation, which keeps the body natural frequencies far away from the maximum frequency. The topology optimization of the established finite element model is carried out by using the topology optimization function provided by Workbench, which finds the best material distribution scheme under the premise of improving strength and stiffness, and optimizes the detail areas of the structure.The innovation of this thesis is to apply the modular design idea to the industrial sewing machine, and divide the machine into independent functional modules from the function of the mechanism, the casing module provides the basis for other function modules and special modules. This paper works for the design and study of the casing module, including developing a parametric design system convenient for designers with the rapid development of computer technology, modeling the casing parts automatically by dimension driven method and realizing the flexible management of parts database with the function of data storage diversity. The different modules can be assembled with a certain combination to form industrial sewing machine with different performance and specifications, which realizes the diversity of products.