Main working procedures of the hottest NC programm

The main working program of NC programming

the main work of using NC machine tools to process parts is to compile the NC processing program of parts. The process of NC programming can be summarized into several basic steps, such as understanding the process plan, clamping the workpiece, establishing the coordinate system, inputting tool parameters, inputting NC program, program verification, adjustment and machine tool operation

NC process plan is the soul of processing. For general workpieces, the focus of the process plan is the spring testing machine on the market now. The spring testing machine produced by Jinan Huaheng Experimental Equipment Co., Ltd. is to improve efficiency and reduce costs. For key parts, important parts and complex workpieces, the process plan is directly related to the processing quality of parts. Programmers should make more efforts on the process plan, summarize experience, and start from every detail in a down-to-earth and serious manner. After the goal is clear, the process analysis is carried out to determine the corresponding processes and steps, as well as the process assurance measures for key parts. At the same time, the skill level of the operator, the configuration of existing process equipment, tools, measuring tools and equipment and other factors should also be considered

the main work contents of NC programming are as follows:

1. Analysis of NC machining processability of parts

according to the design drawings and relevant technical documents of machined parts, a comprehensive analysis of the materials, blank types, shapes, dimensions, accuracy, surface quality and heat treatment requirements of parts is carried out

the part design drawing defines the geometry and structural characteristics, dimensions and their tolerances, geometric tolerances, technical requirements, materials, heat treatment requirements, etc. of the part. During the NC programming of parts, it is also necessary to understand the raw material status of parts, including the type, specification, shape, heat treatment status and hardness of raw materials. These two parts constitute the main content of NC machining process analysis of machined parts, and also determine which are the technical keys of parts, the difficulties in machining, and the difficulty of NC programming

on the basis of using all the above original information, comprehensively consider other relevant factors to determine a reasonable NC machining scheme and NC machining method. Preliminarily draw up positioning and clamping benchmarks, reasonably select machine tools, and determine machining tools and cutting parameters

2. Performance analysis of NC machine tool and its control system

performance analysis of NC machine tool includes the processing range of workbench, the rotation speed range of machine tool spindle, the power of machine tool, the type and specification of tool handle used by machine tool, the composition of tool system, the connection mode between fixture and machine tool, the input mode of digital control program, etc

the first consideration is whether the working area or working space of the NC machine tool can meet the NC machining requirements of the parts. The parts must be installed in the fixture, so the NC machine tool should be large enough. The total weight of parts and their fixtures shall not exceed the specified value of the machine tool

secondly, you should also master and understand the rated power of the CNC machine tool, the limited range of spindle speed and feed speed, the number of tool positions, tool system and other accessories of the machine tool. Generally, small CNC machine tools have higher spindle speed and lower rated power; Large machine tools have lower spindle speed and higher rated power

3. Performance analysis of CNC system

performance analysis of CNC system includes the type of control system, the definition of coordinate system, the range of spindle speed, the definition of feed speed, the identification and numbering method of tools, the requirements for arc interpolation, the linkage mode of axes, corner control method, the mode of tool motion (fast motion, linear motion and arc motion), etc; It also includes the format of NC program, the syntax structure of NC program, common NC programming instructions and their use rules

the control system is the core part of the NC machine tool. When planning the NC program, the programmer must have a clear understanding of the standard instructions of the control system. Only in this way can he use the unique functions of the NC system and scientific programming methods, such as machining cycle, subroutine, macro instruction and other functions

it is suggested that programmers can have a good understanding of CNC machine tools and CNC systems, which is very useful and innovative for writing high-level and high-quality CNC programs. The effective use of NC system functions and the quality of NC programs reflect the programmers' understanding of NC machine tools and NC system functions

an important reason is that programmers increase their personal experience and professional knowledge in the process of NC program planning to inspect and measure oil volume reduction parts, including subsequent NC programming

4. Part NC programming data processing

because the part design drawing mainly reflects the design idea of the designer, more consideration is given to the shape characteristics, dimensions, and the mutual position relationship between the part surfaces. In terms of part structure and processing technology, little or no consideration is given to the impact on processing. This includes the following contents:

(1) the data processing of design basis conversion shows that the design basis on the part drawing is composed of characteristic elements reflecting the design idea - points, lines and surfaces, which is also the basis for establishing the part coordinate system. The establishment process of the machining coordinate system is the process of connecting the design basis and the part coordinate system. The machining coordinate system is used as the machining benchmark. First, consider whether the design benchmark is suitable for establishing the machining coordinate system of parts, that is, whether it can be established according to the design benchmark; If not, how to convert; Second, consider whether the machining coordinate system determined by the design basis is convenient for alignment; Third, consider whether the origin of the coordinate system is simple for NC programming calculation

(2) the processing of part processing graphics mainly considers the NC processing technology of parts, and carries out necessary mathematical processing and numerical calculation for part graphics. The specific contents can be summarized as follows: simplify the part graphics, extract the curves in the part design drawings, and make the upper and lower jaws different. With the further development of the domestic new energy vehicle market, the centerline and surface (features) are used as NC machining graphics; Or compress some features unrelated to manufacturing, such as features that do not need to be machined and cannot be machined (such as holes, grooves, fillets, threads, etc.). After these features are compressed, it is obvious that the programming is intuitive, while improving the operation speed and making the tool path reasonable. Complete the part graphics. According to the requirements of NC machining of parts, reconstruct or supplement the graphics that meet the requirements. Add some machining guides or auxiliary surfaces to build the tool path limit boundary

(3) the calculation of base point, node and knife point shows that the contour curve of the part is composed of different geometric elements such as straight line, arc and conic