3 Design of a dedicated CAD system
3.1 Principle structure of the system
Figure 1 is a schematic diagram of the basic module division and its function of a simplified dedicated CAD system. among them:
Rule base: accumulated by the manufacturer's many years of production experience. It contains the rules for the size and position of each component under different models and different requirements. It is the key to automatic plotting.
Figure 1 Schematic diagram of the CAD system for the air conditioner frame
Reasoner: Extract rules from the rule base, analyze them, and generate 3D models of components.
3D model: It is the core of the whole dedicated CAD system. It not only contains the geometric information of the parts, but also contains all the useful information such as assembly information and production information of the parts. It is the mapping of the parts in the computer.
2D view: It is the projection of a component on a plane. It is the basic unit for interactive modification on the drawing. The 3D model forms a one-to-many relationship with it.
Blanking module: According to the 3D model, general blanking and special blanking are applied to the flexible 2D view.
Processing information generation module: Generate processing information according to the 3D module, such as CN code.
3.2 The specific implementation of the modeling part
The following are some of the key points in the design and implementation.
(a) Establishment of a rule base
The rule base is the key to the automatic generation of drawings, and it is also the database for the manufacturers to produce materials for many years. These materials are stored in the form of examples (inquiries about the examples, which are not discussed here). The following is an example of a simplified air conditioning cabinet, the main part of the system, which illustrates the basic idea of ​​the system setup example:
Instance name: The name of the instance.
Room type name: air conditioner cabinet room name, such as the fan room, coil room, etc. mentioned above.
Generation rule: Equivalent to the IF name of the rule. When the condition is met, the angle iron entity is created based on the information in the rule.
Angle iron ID: Record the ID number of the angle iron to be generated for other angle irons (panels or other parts) to reference it.
The head is connected to the angle iron ID, and the tail is connected to the angle iron ID: the assembly relationship of the angle iron is recorded.
Dimensional calculation formula: An expression for recording the various dimensions of the angle iron.
After the retrieved instance, an assembly drawing is generated based on the information of each of the parts.
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Kaiping Jenor Sanitary Ware Co., Ltd , https://www.kpjenorsanitary.com