CNC process decision-making model levy - its profile processing method chain in the ordinary process MC may be rough car and follow the control process to establish the H.cki.net CNC machining process has the following characteristics: CNC machine tool processing accuracy. Generally, the precision of the processing part can be achieved with only one processing, without the need for roughing and finishing.
On the CNC machine tool, the workpiece can be clamped at one time, and multiple parts can be processed, and sometimes even the entire processing content of the workpiece can be completed.
Since there are several or more spare tools on the tool magazine or tool holder, the configuration, installation and use of the tool when machining the workpiece on the CNC machine do not need to interrupt the machining process, so that the machining process is continuous.
According to the characteristics of the workpiece clamping and the tool configuration and the use characteristics of the CNC machine tool processing, it is different from the normal machine tool processing. The NC machining sequence of each part of the workpiece may be very different from the order of machining the workpiece on the ordinary machine tool.
The process in the CNC machining process is relatively concentrated, so the process content in the CNC process specification is particularly detailed. For example, the machining position, machining sequence, tool configuration and use sequence, tool path, tool path, cutting parameters, etc. during tool machining are more detailed than those in the ordinary machine tool machining process.
The NC process is the preparation of the NC machining program to prepare the necessary process information, and the CNC process decision rule is the principle and mechanism of the CNC process creation. It is also the basis of the CNC machining process decision expert system. Due to the characteristics of the above-mentioned CNC machining process, it is decided that in the CAPP system, the NC process decision rules are different from the process decision rules of ordinary machine tools. The decision rules of NC machining process in the CAPP system are summarized as follows.
The CNC machine tool can complete the processing of the machining surface with precision requirements on the workpiece at one time. Therefore, there is a difference between the establishment of the characteristic profile machining method chain of the workpiece characteristic profile processing method chain and the ordinary machining. Such as a special semi-finished car ※ fine car; and in the CNC machining process decision, may only be CNC turning, but in the CNC turning process, several passes or switch to different turning tools and cutting amount.
CNC machine tools sometimes have two power heads, and CNC machining can complete the machining tasks that can be completed by ordinary machining several times. Therefore, in the decision of the numerical control process, the content of one process can be determined according to the processing tasks that can be completed by one clamping.
Since the configuration, installation and use of tools in CNC machining are different from ordinary machine tools, the rules followed in the process decision-making merge are different from the rules of common machining steps. The configuration and sequence of tools should be followed during CNC machining. With the change of the knife. On the ordinary machine tool, the contents that cannot be merged into the same step may be merged into the same step on the CNC machine.
The ordering of the process in the machining process decision of CNC machine tools should be consistent with the characteristics of CNC machine tool workpiece clamping and tool configuration, tool change and so on.
The content of the numerical control process needs to be described in detail. In the process decision-making, the detailed rules of the process and the work step should be followed, that is, the rules such as automatic selection and matching of the machine tool, automatic selection of the tool, and automatic selection and matching of the cutting parameters in the process decision making are made in detail to make the decision. The post-process is detailed.
The numerical control process results should have both the process documentation file (.doc) and the process code file (.cod) (this is the internal file of the CAPP system) so that the NC tool path file generation "module utilizes the code process file (.cod) to generate the NC. The tool path data file (.dat) and the general processing CAPP only need to generate the process document file (.
The meter uses the numerical control processing based on the feature surface of the part to establish the number until the stage of the numerical control process. In each feature, the NC machining method is based on NC?ME (NCmanufacturing?element). After the decision, according to the machining accuracy of the CNC machine tool, the clamping method of the workpiece and the addition), the NC machining element NC is the entity of the NC machining information with the feature of the part as the core. It is the basic of the NC machining process. The instruction is formed by matching the NC machining method and the feature matching of the parts in the NC machining process rules. After the parts are determined, each feature primitive (the feature primitives including the main shape features along with their associated precision features, material features, technical features, etc.) of the component parts are searched for the NC machining method chain library of the corresponding part features one by one. The NC machining method chain to the corresponding features obtains the relational model of NCME.TM and manufacturing resources of the part (see). Through the matching of CNC machining element NC?ME and CNC machining manufacturing resources, the NC machining process element NC?WE (NCWork machining process element NC? WE CNC machining process specification hierarchical structure (see). CNC machining process The primitive is the basic element of NC machining activities, which can be regarded as the operation of the state space. The numerical control process can be considered as the state space composed of the initial state (hairy) to the final state (a series of states).
The hierarchical structure of the step-by-step numerical control process specification 4. The numerical control process creation process (see) The numerical control process creation process is divided into two stages : “positive dispersion†and “reverse concentration†.
By scanning the feature information base of the part, discriminating the feature type, reading the feature parameters, and matching and optimizing with the numerical control machining methods of each feature in the numerical control process rule, determining the common rules on the numerical control machining methods of each feature (such as the first master The second, first and second holes, etc.) The NC machining steps and the merging and sorting of the process, the rough CNC process is based on the characteristics of the NC machining method, and the relationship between the NCME and the NC manufacturing resources is used to scan the capacity library of the CNC machine tool. According to the information of CNC workshop, the technical parameters of CNC machine tools and the overall information of the parts, the CNC machine tools are selected reasonably; then according to the machining position of CNC machine tools and the NC machining methods of various features, the design steps are redesigned and the necessary steps are reordered and Then merge; finally, according to the NC machining features of each step, the numerical position of the CNC machining equipment and CNC machine tools, CNC machining features, select the fixtures, tools, measuring tools and other technical equipment for CNC machining. This completes the design of the CNC process card. Then, according to the machining condition of the numerical control step, the amount of CNC machining cutting is determined, and the machining time and other conditions are used to determine the CNC machining man-hour.
Conclusion By studying the characteristics of numerical control technology, the conclusions of numerical control process decision-making are summarized. On the basis of the numerical control process decision rules, the numerical control process decision model is established, so that the automatic creation of the numerical control process can be smoothly carried out.
The research on the automatic creation process of numerical control technology has laid an important foundation for the development of CNC CAPP and CNC machining CAD/CAPPi:AM.
Hmc Machining Center,5 Axis Horizontal Machining Center,Vertical And Horizontal Machining Center,Horizontal Machining Center
Dongguan Liyang Intelligent Technology Co., Ltd , https://www.leyomachine.com