CNC Machining Parts Program Structure
CNC machining, refers to the CNC machine tools for processing a part of the process, CNC machine tool processing and traditional machine tool processing procedures are generally the same, but also has undergone significant changes. Machining method for controlling the displacement of parts and tools with digital information. It is an effective way to solve the problem of variable variety, small batch, complex shape, high precision and high efficiency and automatic processing.
CNC machining program preparation methods are manual (manual) programming and automatic programming of the points. Manual programming, the entire contents of the program is manually by the NC system specified by the instruction format written. Automatic programming is computer programming, can be divided into language and painting based on the automatic programming method. However, no matter what kind of automatic programming method, need to have the appropriate supporting hardware and software.
It can be seen that the realization of CNC machining programming is the key. But the programming is not enough light, CNC machining also includes programming must be done before a series of preparatory work and after the preparation of the aftermath of the work. In general, CNC machining process mainly includes the following:
(1) to select and determine the parts and contents for CNC machining;
⑵ the part of the drawings for CNC machining process analysis;
⑶ CNC machining process design;
⑷ mathematical processing of parts drawings;
⑸ preparation of processing procedures;
⑹ according to the program production control medium;
(7) Verification and modification of the program;
⑻ the first piece of test processing and on-site problem processing;
⑼ CNC machining process file stereotypes and archiving.
In order to improve the degree of production automation, shorten the programming time and reduce the cost of CNC machining, in the aerospace industry also developed and used a series of advanced CNC machining technology. Such as computer numerical control, that is, with a small or microcomputer instead of CNC controller in the system, and stored in the computer software to perform the calculation and control functions, this soft-connected computer numerical control system is gradually replacing the initial state of the numerical control system. Direct CNC is a computer directly control multiple CNC machine tools, it is suitable for small batch short-cycle production of the aircraft. The ideal control system is an adaptive control system that can continuously change the machining parameters. Although the system itself is complex and expensive, it can improve the processing efficiency and quality. The development of CNC In addition to the hardware aspects of the CNC system and machine improvement, there is another important aspect is the development of software. Computer-aided programming (also called automatic programming) is written by the programmer in a numerical language, it is input to the computer for translation, and finally by the computer automatically output perforation tape or tape. The more widely used CNC language is the APT language. It is roughly divided into main processing and post-processing. The former programmer to write the program to be translated to calculate the tool path; the latter tool path into a CNC machine tool parts processing program. CNC machining, in the workpiece before processing in advance on the computer to prepare a good program, and then enter these procedures to the use of computer program control machine for instructional processing, or directly in the computer program control machine control panel to write instructions For processing. Processing process includes: knife, tool change, speed, change, parking, etc., are automatically completed. CNC machining is a modern mold manufacturing and processing of an advanced means. Of course, CNC machining means must not only for the mold parts processing, use a very wide range.
A block is a continuous block that can be processed as a unit, and it is actually a program in a CNC machining program. The main part of the part processing program consists of several blocks. Most blocks are used to instruct the machine to complete or perform an action. The block is made up of size words, non-size words, and block end instructions. When writing and printing, each block generally occupies one line, as is the case when the program is displayed on the screen.
The conventional machining program consists of a start character (a single column), a program name (a single column), a program body, and a program end instruction (typically a single column). At the end of the program there is a program end character. The program start character is the same character as the program end character:% in the ISO code, ER in the EIA code. The program end instruction can be used with M02 (program concatenation) or M30 (end of tape). CNC machine tools are generally run using a stored program, and M02 and M30 have in common that the spindle, coolant and feed are stopped and the control system is reset after completing all the other instructions in the block. M02 and M30 are fully equivalent when used on some machines (systems), and on other machines (systems) there are the following differences: the end of the program with M02, after the end of the automatic operation at the end of the program at the end of the cursor; End of the program with M3O running, automatic operation after the end of the cursor and the screen display can automatically return to the beginning of the program, press the start button to run the program again. Although M02 and M30 allow a program block to be used in conjunction with other program words, it is best to separate it or share only one block with the sequence number.
The program name is located before the program body, after the start of the program, it is generally exclusive. There are two forms of program name: one is the provisions of the English word (multi-use O) at the beginning, followed by a number of digits followed. The maximum number of digits allowed by the number of instructions, the common is two and four. This form of program name can also be called program number. Another form is that the program name by the English word, digital or English, digital mix, the middle can also join the "-" number. This form makes the user naming program more flexible, for example, in the LC30 CNC lathe processing part number 215 of the flange third process procedures, can be named LC30-FIANGE-215-3, which to use, storage And retrieval to bring great convenience. Program name with which form is determined by the numerical control system.