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Figure 4 Threaded CAD flow chart
This system introduces integrated design pattern (System technical components shown in Figure 1), joint use of Visual C ++ 6.0 / Object ARX and other tools to create a complete design system to achieve a fully automated design, the threaded coupling of CAD (including type selection, parameter Determination, intensity calculation, automatic generation of graphics, integration of standard parts table sorting output, etc.).
The system structure is shown in Figure 2. The system function module is shown in Figure 3. The system is mainly composed of six functional modules: type selection, strength check, drawing function, standard part table output, file management and help.
Figure 4 is a CAD diagram of the threaded joint. The meaning of the input and output variables in the figure is as follows: TY - the type of threaded joint; LX - the type of force applied to the thread; HD - the thickness of the joint being connected; ZX - the joint Frequent disassembly; SJ - type of looseness of the joint; KZ - whether the pre-tightening force needs to be controlled when the joint is tight; CL1 - the material of the coupled part; CL2 - the mechanical performance grade of the material of the threaded standard part; F - The size of the force applied to the threaded coupling group; Z——the number of standard parts of the threaded joint in the threaded coupling group; K——the importance of the threaded joint (reliability); M——the nominal diameter of the joint thread; l——nominal Length; mn - the mechanical performance rating of the threaded fastener; C1 - the stiffness of the threaded fastener; C2 - the stiffness of the coupled part.
In system design, AutoCAD graphics database is a key part of ObjectARX development. Since the threaded fastener is a standard part and its pattern is fixed, after drawing these standard parts in AuoCAD2000, the type selection function can call the fastener pattern according to its national label and carry out related dimensioning.
By modifying the AutoCAD menu file, you can add your own application commands to the drop-down menu items to get the user's menu file. In addition, the dialog definition file can be compiled by the dialog control language DCL, and the dialog driver can be written by using the dialog operation function in the ADS library provided by Object ARX.
In the system of thread type selection and strength check, considering the force of the two connected parts, the frequency of disassembly, material and structure size, etc., the knowledge base of thread connection type selection and the thread selected for this design are established. Fastener table, and can output the thread fastener table according to the user's needs, according to the national label, diameter, length and other fields. The design principles for the selection of the thread connection type, the determination of the diameter and length, and the output of the standard parts are as follows: