4.1 Stamping feature
To generate appropriate process plans, the product data requires the original inputs, which includes the geometry, topology, tolerance, material and quantity of product.
Based on the feature technology and stamping technology,
4 Key points of process path generation
Unigraphics has several features that provide a subset of the capabilities of a KBE language—UG/KFL, which provides a way to specify knowledge rules that can cover all Unigraphics applications. The stamping CAPP system for automobile panels has been developed based on the frameworks advanced above, which choose C and UG/KF language as the implementation language, and ACCESS as its database on the UG/CAD development environ- ment. UG/Open and UG/Open++ allow customization and extension of Unigraphics using a standard procedural language (C and C++). UG/KFL provides a way to specify knowledge rules that can cover all Unigraphics applica- tions. Rules of UG/KFL are easily written by the developer, easy to read, understandable, and reusable by the user. Furthermore, UG/Open can be integrated with KBE by
a stamping feature is the portion of a part which can be formed by means of certain stamping operations. For ex- ample, a drawn feature or bend feature is defined as the main feature, which is to describe the near net shape of a component, while flange, hole, emboss, bead, notch and flange-hole are defined as the auxiliary ones, which are required to describe the local part of the final shape.
Using feature technology and the geometry extraction method, the stamping design features, such as the main forming feature (e.g. drawing, bend), flange, hole, emboss, bead, notch, and so on, can be extracted from a 3D solid model, which are first defined as UG/UDO. For example, Fig. 3 shows the stamping features of one automobile panel. The stamping feature model should then be defined to represent product knowledge integrated and unambiguous. The stamping feature is represented as object-oriented class or object and instance using UG/KF language (UG/KFL); it
Fig. 3 Stamping features of automobile panel
not only represents feature parameters, tolerance, material, etc. as attributes of class or instance, but also represents geometrical objects by importing UG/UDO and UG/UDF referenced solid geometry as an instance attribute or child. And this realizes the connectivity and integration between the symbol of a feature and its geometrical object. It can also get an attribute value from a function, rule, expression and database. The following is the hole class created by UG/KF. If the attribute parameters of the class are valued, the object or instance of the hole is confirmed concretely. Others can also be expressed similarly.
DefClass: pdcapp_hole_feat(ug_base_part); # name for hole feature class
(string modifiable parameter) hole_id: “variable”;
#name of hole.
(integer modifiable parameter) hole_type: variable;
# the typeof hole.
(string ) geomtry_id: “udo_name”; #reference name of edges group.
(string ) parent_feature: “feature name”; # reference name of parent feature.
(number) radius: askholeradius (hole_id:); #get value from function.
(integer modifiable parameter) tolerance: variable;
# tolerance level.
(Number modifiable parameter) part_Thickness: number variable;
(string modifiable parameter) material:”material_ name” ; 计算机辅助工艺规划CAPP系统英文文献和中文翻译(5):http://www.751com.cn/fanyi/lunwen_77413.html