First, establish the principle of the table drive part model library In the series design process of the product, in order to speed up the product design process and reduce repetitive labor, a three-dimensional model library with the same structural shape and only different size parts, such as screws, bolts, nuts, washers, seals, and lubrication parts, should be established. Bearings and other standard parts. Although UG provides many secondary development tools (such as UG/Open GRIP, UG/Open API, and UG/Open, etc.), the use of secondary development tools requires designers to have relatively high technology, which is difficult for general designers to complete. The use of table-driven technology provided by UG can also create standard parts, universal parts, and a series of three-dimensional model library for product design. After creating a three-dimensional parametric model, set design variables and assign design variables to the model. Then create an external spreadsheet containing these variables and link the spreadsheet to the current model. Because the variables in the spreadsheet are referenced by the part size of the current graphics file, this table can be used to change the size of the parts in the current graphics file, so the user can modify the parts by controlling the external spreadsheet to avoid the design. The change has to modify the loss caused by a large number of model parameters, and use a model to express multiple parts of the same structure. Second, establish a three-dimensional parametric model based on table-driven parts 1. Analyze part features In order to create a table-driven part efficiently, the part must be carefully analyzed before designing. First, the general idea of ​​modeling the part should be formed as a whole, and what features need to be created and the sequence of creating these features must be clearly defined. It is also necessary to pay attention to the intrinsic connections of the various features to be created and their respective characteristics. Finally, it is clear that the part needs several parameters to drive. In order to realize the parametric design of the three-dimensional model, the size and geometry constraints of the parts are firstly required to determine the unique part shape. As shown in Figure 1, the part requires 8 dimensional constraints and some geometric constraints. The size constraint is shown in Figure 1. The geometric constraints include: the four straight lines in the top view are each tangent to the adjacent arc; three circles or arcs with diameters of 25mm, 40mm, and radius of 28mm are the same as the center of the circle; the arcs with the radius of 15mm and the circle of the diameter of 16mm are the same; A circle with a diameter of 16mm is horizontally connected. Through the establishment of the above dimensional constraints and geometric constraints, the uniqueness of the parts is guaranteed. 2. Create a part model Based on the analysis of parts, according to the characteristics of the parts, to create a variety of features required by the three-dimensional parametric model, including geometric features and auxiliary features, and use all the constraints of the above analysis to fully constrain the three-dimensional model of the parts. 3. Create and assign design variables UG provides functions to establish relationships between the drive dimensions and the part's model through expressions. Before creating the table driver, assign the already-determined design variables to the corresponding dimensions by renamed expressions, as shown in Figure 2 and Figure 3. The constraint size is re-edited in UG so that the assignment of design variables is completed. 4. Create a table drive In UG, a series of dimensions of a part can be completely built in a spreadsheet to form a part database. This is convenient for the management, editing, and expansion of this database. Specifically, one or more data in the table may be arbitrarily modified, a new set of part data may be added, design variables may be added, and the like. Finally, a three-dimensional model of a series of parts using the same solid model is generated. 1) Click on the menu "Tools → Expression", rename and edit the parameter expression, as shown in Figure 2; 2) Click on the menu "Tools → Part Families", the system will pop up as shown in Figure 4 "Part Families" dialog box, double-click each expression in the parameter box to be extracted shown in Figure 3, then these expressions will In the "Extracted Parameters" list, set "Family Save Dictionary" to "E:\falan", then click "Create" to enter the "Spreadsheet" to create the part library; 3) At this time, the system will pop up the Excel worksheet shown in Figure 5, in which the system generates 8 data columns corresponding to the 8 parameters just extracted. Enter the relevant parameter values ​​for the PartName and series of parts in the table. Use the spreadsheet (Excel) to create the following data (see Figure 4). This data format can be directly linked with UG, thus achieving a three-dimensional parametric model of the part. The first row of each design variable in the table, namely the field names in the database, each row of one record below, represents a set of parameters that determine the size of a part. After the input is complete, you can use the "verify part" under the "PartFamily" menu to generate a part to make sure the parameter selection is correct. After the above work is clear, the "Save Family" under "PartFamily" can be selected to store the electronic format; 4) Select 3 to 8 columns in the worksheet shown in Figure 5, and then click "Create parts" under the "PartFamily" menu in the Excel program to generate the family of family parts in the specified working directory. Third, the conclusion The use of table-driven technology to create a three-dimensional model library for a series of parts is perfectly feasible, and a technician familiar with UG can quickly master the technology. Utilizing the solid modeling function of UG to build a three-dimensional part model and using table drive technology to set up a three-dimensional parametric model of the part by setting reasonable design parameters, the method is simple and easy to operate, and it is a very practical three-dimensional parametric design method. High Pressure Switch,Low-Pressure Switch For Water Purifier,Water Purifier Low Pressure Switch,Water Low Pressure Switch Zhejiang Hongchang Electrical Technology Co.,Ltd , https://www.hongchangelectrical.com
Often encountered in the design of similar shapes, but not exactly the same size of the parts, such as serialized product parts, commonly used standard parts. The two-dimensional design of these parts is currently relatively mature. However, with the development of CAD/CAM technology, the design and manufacturing of products have undergone a new development, that is, from the three-dimensional to two-dimensional design steps, that is, the first to establish a three-dimensional model, and then automatically generate two-dimensional engineering drawings, or use The three-dimensional part model directly generates the numerical control code, realizes no drawing processing, saves time and costs. Therefore, the establishment of a three-dimensional parametric model of a part is particularly important. It will make it possible to serialize the structural design of the product, greatly shorten the structural design cycle, and reduce the workload of the engineer due to the dimensional change of the part. 
Figure 1 The dimensional constraints of the part 
Figure 2 Assigning Design Variables 
Figure 3 Rename expression
The steps for creating a spreadsheet in UG are as follows: 
Figure 4 Part Families dialog 
Figure 5 Excel worksheet 
Figure 6 Creating a series of parts
This paper describes the method and steps of UG-driven table-driven three-dimensional parametric part library, and discusses in detail how to establish parametric models, determine design variables, assign design variables to models, and set and edit electronic tables with an example. . Practice has proved that using this method, a three-dimensional parametric model library of parts can be established conveniently and quickly to achieve serialized design of parts and design efficiency can be greatly improved.