The application range of the subroutine processes the part. When there is the same processing content, the part of the processing content is programmed into a subroutine to be called, which can simplify the program and reduce the programming workload. The application of subroutines from the regularity of the structural features of the parts, the roughening of the machining process, and the multi-piece machining has obvious advantages. Structural features have regular parts. Some parts are in different parts, and their structural shape is identical, such as the same diameter, the same length of the journal on the stepped shaft, several connecting journals on the crankshaft parts, and the same diameter on the porous part. The hole, the same size of the boss on the multi-bolt part. By machining these identical parts and the trajectory of the tool is the same, a subroutine can be programmed. Some parts have structural features that are incremental or decremented, such as multi-stepped shafts, which are sized to form a series of holes or slots. When machining these parts, the tool moves in the same way, and a subroutine can still be programmed. The processing of rough and finished parts often requires a division of the machining stage for roughing and finishing. Since the machining steps of roughing and finishing are the same, the tool moves in the same way. In order to simplify the program, subroutines should be applied. Not only that, but also multi-subprogramming can be applied. When processing multiple small parts with regular shapes, it is common to combine multiple pieces into one blank, and after processing to a certain stage, separate into a single piece. For the machining of these parts, subroutines can be programmed for one of the parts, such as turning small bushing parts. When milling, drilling, etc., a small number of small parts, multi-station processing is often used to increase productivity. When multiple pieces of machining are performed under the same installation, since the machining steps, machine movements, and tool movements of each workpiece are the same, a subroutine can be applied by the machining process of one workpiece. Multiple subroutine programming can also be applied. Comparison of subroutines and cyclic programming functions Some high-end CNC systems provide subroutine functions as well as cyclic programming functions, which make programming simple. When subprogramming is applied, the subroutine is called in the main program. If the calling format is only 1 call, the following format can also be used; the subroutine application article of NC machining summarizes the application range of the NC machining subroutine. By comparing with the loop function which can also simplify programming, it is known that the application subroutine is flexible and convenient, and it is easy to ensure the processing quality and improve the efficiency. It also explains the aspects that should be noted in the application of subprogramming. Application of composite loop function programming and subprogramming have their own advantages and disadvantages. From the format of the turning compound cycle G73 command, it is known that the programming with the compound cycle function is simple and it is not easy to generate calculation errors. However, the use of the delay function G04 command is invalid, which affects the improvement of the machining quality of the parts. Moreover, because it is not convenient to directly change the tool, it is difficult to effectively improve efficiency and reduce costs under the premise of ensuring quality. Although the application subroutine programming is easy to cause human error, the G04 command can be used reasonably, and it is easy to change the tool in time. Therefore, the tool can be used reasonably to ensure the processing quality of the parts, improve the processing efficiency, and reduce the production cost. When applying subroutine programming, as long as you carefully study and carefully review, you can develop your strengths and avoid weaknesses and give full play to the role of CNC machine tools. Application subroutine should pay attention to the problem Absolute programming and incremental programming When applying subroutine programming, in the subroutine, because the reflected repetitive motion of the tool path is the incremental path on the last basis, the incremental size is required. The relationship is described, so use the G91 command. When returning to the main program at the end of the subroutine call, attention should be paid to the coordination with the main program G command. When the main program uses the G90 instruction, the subroutine should be changed when it returns. Otherwise, the main program segment after the subroutine is called is also executed according to the G91 instruction and an error is generated. Absolute programming and incremental programming applications, Huazhong CNC system requirements are consistent with the same paragraph, can not be mixed, absolute programming with G90 instructions, incremental programming with G91 instructions; the system can perform absolute programming and incremental programming in one segment at the same time. After determining the amount of rough and finished backing knife, the subroutine is used for roughing and finishing, and the number of times the roughing call subroutine is determined according to the machining allowance and the size. The feed rate or feed rate has a great influence on the machining efficiency and surface quality. Different feed or feed speeds for coarse and fine machining can be set by subroutine or multiple subroutine. When the minimum workpiece surface roughness is the first optimization target, the feed amount f is the main factor affecting the surface roughness of the workpiece, so the value of f should be as small as possible. Roughing sets a large feed for increasing efficiency; finishing requires a small feed to ensure a good surface quality. According to the principle of cutting amount, when roughing, it is larger, so choose a smaller cutting speed; when finishing, choose a larger one. It is represented in the program by the spindle function S. Also, it can be set in a subroutine or multiple subroutine. The versatility and modularity of the program In the cutting process, the program needs to be modified due to factors such as wear or replacement. After applying the subroutine, it should be able to adjust the setting of the tool compensation amount to ensure the dimensional stability of a batch of parts. This ensures a stable processing quality. Application subprogramming, for series of parts, should be able to modify only the critical dimensions or a small amount of deletion and addition, can adapt to the processing of the series of parts, in order to ensure the versatility of the program. Application subprogramming makes it easy to modularize the program structure. Programmers should write programs in a modular way, giving full play to the utility of subroutines, facilitating the optimization of NC machining programs and system management. (Finish) Air Compressors with Gasoline Engine, Gasoline Air Compressor, Air-Compressor,Auto Compressor Co., Ltd. , http://www.liyangcompressor.com