Tricone bit jaw CAPP system (3)
3.3 Feature Sorting Figure 3 Mapping from the feature process chain to the routing (1) The sorting step of the step of the step is to sort the work step contents of each feature process chain of the part according to certain rules. In order to sort the work steps, the priority level can be set for each work step, and the priority is large. Priority processing. The determination of the priority involves three factors: the processing stage, the type of processing and the priority processing level of the feature. For example, the roughing priority is greater than the finishing priority; the turning priority is greater than the thread priority. The impact of these three factors on the priority level is represented by its impact value. The processing stage has the largest impact value. Therefore, the final priority level of a work step is determined on the basis of comprehensive assessment of the above three influencing factors, which can be expressed as Previous page 2 tier Cooling Rack,3 tier Cooling Rack,Foldable Cooling Rack,Creative Cooling Rack Shenzhen Lanejoy Technology Co.,LTD , https://www.wire-spring.com
The claw parts are composed of several features. Due to the differences in shape, size and precision of each feature and the complex spatial positional relationship among the features, this restricts the order of feature processing. It is therefore necessary to sort the features. In order to determine the processing priority of each feature, the part processing features are divided into related features and independent features. The so-called associated features are those that have dimensional, precision and geometric tolerance requirements in spatial position, while independent features refer to those that do not. There is no requirement for the positional relationship (size, accuracy) of the spatial position relationship. The system uses the following control strategies for sorting features.
(1) The constraint relationship of the associated feature is sorted according to the relationship between the feature and other feature positional relationships or the accuracy of the contact size.
(2) Other features used as a reference after the benchmark should be processed first.
(3) The first master and the second arrange the main feature processing first, and then arrange the processing of the secondary features.
(4) After the first face and the back hole, the plane is first processed, and then the hole is processed.
(5) Arrange external feature processing first, then arrange internal feature processing.
According to the feature parameters in the feature list, combined with the determined feature location scheme, the above control strategy is used for reasoning, and the feature ranking can be realized to determine the priority processing level of each feature. When the processing process is arranged in the same processing stage, the feature must be sorted according to the feature. The result is to achieve the order of processing of each feature.
3.4 Process route generation
The essence of the process route is the completion of the process generation, the arrangement of the process sequence and the reorganization of each step in each feature process segment in each process. The mapping process is shown in Figure 3. The generation of the system routing is achieved as follows. 
Priority=f(Cut_Phrase, Cut_Type, Feature_Priority)
Where: Priority represents processing priority, Cut_Phrase represents processing phase, Cut_Type represents processing type, and Feature_Priority represents feature priority. The system sorts the steps according to the size of the final priority level of each step.
(2) The process of combining the step into the process of generating the process is: according to the result of the step sorting, sequentially taking out the steps in the step, and generating a process, if the adjacent subsequent steps can be processed on a certain machine tool When completed, these steps are attributed to the same process; otherwise, a new process is generated. By analogy, the process can be completed. Of course, in the process of step by step, we must also give due consideration to the problem of concentration and dispersion of processes. Obviously, the process of generating the process actually completes the choice of the machine tool.
The above process design method is simple, convenient and reliable, and also simplifies the structural design of the program. The resulting route results are basically in line with the actual processing conditions.