CNC Programming
CNC machining program creation methods are divided into manual (human) programming and automatic programming. In manual programming, the entire program is written manually according to the instruction format specified by the CNC system. Automatic programming, or computer programming, can be divided into automatic programming methods based on language and drawing. However, regardless of the automatic programming method used, corresponding supporting hardware and software are required.
Therefore, implementing CNC machining programming is crucial. But programming alone is not enough; CNC machining also includes a series of preparatory work before programming and post-programming processing. Generally, the main contents of CNC machining processes include the following:
⑴ Selecting and determining the parts and content to be CNC machined;
⑵ Performing CNC machining process analysis on the part drawings;
⑶ CNC machining process design;
⑷ Mathematical processing of the part drawings;
⑸ Writing the machining program sheet;
⑹ Creating the control medium according to the program sheet;
⑺ Program verification and modification;
⑻ First-piece trial machining and handling on-site problems;
⑼ Finalizing and archiving CNC machining process documents.
To improve production automation, shorten programming time, and reduce CNC machining costs, a series of advanced CNC machining technologies have been developed and used in the aerospace industry. These include Computer Numerical Control (CNC), which uses a small or microcomputer to replace the controller in a CNC system and uses software stored in the computer to perform calculations and control functions. This type of soft-connected CNC system is gradually replacing the initial CNC system. Direct CNC uses one computer to directly control multiple CNC machine tools, making it well-suited for small-batch, short-cycle production of aircraft. An ideal control system is an adaptive control system that can continuously change machining parameters. Although the system itself is complex and expensive, it can improve machining efficiency and quality. Besides hardware improvements to CNC systems and machine tools, another important aspect of CNC development is software development. Computer-aided programming (also called automatic programming) involves programmers writing programs in CNC languages, inputting them into a computer for translation, and finally, the computer automatically outputting punched tape or magnetic tape. A widely used CNC language is APT (Automatic Programming Language). It is broadly divided into a main processing program and a post-processing program. The former translates the program written by the programmer and calculates the tool path; the latter compiles the tool path into a machining program for a CNC machine tool. CNC machining involves pre-writing programs on a computer before machining the workpiece, then inputting these programs into a computer-controlled machine tool for instruction-based machining, or directly writing instructions on the control panel of such a computer-controlled machine tool. The machining process includes tool feed, tool change, speed change, direction change, and stopping, all of which are completed automatically. CNC machining is an advanced method in modern mold manufacturing. Of course, CNC machining is not limited to mold parts processing; its applications are very wide-ranging.