What is CNC machining process in production?

Do a good job of CNC milling process work, and gradually improve and perfect the CNC milling process preparation, for product quality, processing efficiency, and cost are of vital importance.

Compared with ordinary machine tools, CNC milling machine tools have their characteristics, first of all, the CNC milling machine tool processing program is more complex, so its process regulations are more cumbersome;

Secondly, in the use of CNC milling machine tools for processing parts, the issues should be more comprehensive, such as the arrangement of work steps within the process, the determination of the tool route and tool change point, and the location of the tool point, etc., these issues in the ordinary machine tools are not to be considered in the CNC milling machine tools must be seriously considered.

Usually, CNC milling machine tool machining process preparation work mainly includes the following parts of the content: process analysis, parts clamping and positioning, cutting and tool selection, machining route analysis, and arrangement.

CNC milling process analysis

1. Labeling size

In the process of CNC milling machining process preparation, all the points, lines, and surfaces of the size and location of the determination of the programmed origin as a reference, so in the processing of the object of the diagram should be labeled above the coordinates of the size.

2. Comprehensive elements

In the programming process, they must be able to accurately grasp the composition of the machining object contour of all the set of elements of the parameters, and the relationship between the parameters should also be a clear understanding. The same CNC milling process preparation should also analyze the elements, to ensure that the programming is carried out in an orderly manner, the machining object on the spatial curve, size, shape curve contour, and other content must be determined.

Designers in the design of the problem may not be comprehensive, so the relevant personnel in the review of drawings, but also must be careful, once the problem is found on time with the designers to contact and solve the problem.

3. Accurate positioning

In the process of CNC milling, the machining process is more concentrated, so it is very important to use the same data for positioning.

4. Uniform dimensions and types

To minimize the number of tool changes and shorten the length of each program, the cavity and shape of the machined parts should be of uniform size and geometry, and the shape of the machined parts should be geometrically symmetrical, so that the mirror function of the CNC machine can be used to program, and the time will be greatly reduced.

CNC milling in the positioning and clamping

In the processing of parts before, one must also ensure that the processing of parts in the machine tool fixture position is correct, and in the process of parts processing, it should always be maintained in the correct position, the processing of parts clamped and pressed, so that it will not be in the cutting force under the action of displacement, and this process is the process of positioning and clamping.

In the process of positioning and clamping of machined parts, we should try to reduce the number of clamping, after positioning and clamping, it is best to be able to process all the surfaces to be machined; in addition to maximize the role of CNC machine tools, it is recommended that the best not to occupy the machine manually adjusted type of machining program.

CNC milling in the tool and cutting volume selection

1. Tool selection

Milling is very important work is to choose the right milling cutter, the choice of tools, should follow the principles of high precision, high strength, good rigidity, ease to adjust, and long service life, in addition to the choice of milling cutter should also be consistent with the object of processing.

In the actual processing work, the choice of milling cutter should also refer to the geometric parameters of the processed parts, for example, is the processing of closed keyway should be selected keyway milling cutter, the machining plane should be selected face milling cutter, and so on.

2. Selection of Cutting Dosage

Cutting operation of all the parameters of the movement of the general term is called cutting amount, such as feed, cutting speed and spindle speed, and other parameters, the life of the milling cutter is a process with a cutting amount has a close relationship with the parameters, usually we will be divided into two categories of the maximum productivity of life and the lowest cost of the economic life, and according to the difference between the two we choose the cutting amount of cutting for the maximum productivity of cutting and the lowest cost of cutting two kinds of, and according to the difference between the two, we choose the maximum production of cutting and the lowest cost of cutting, and we choose the maximum production of cutting. The minimum cost of cutting two kinds, usually we choose the latter and the maximum productivity of cutting only in the urgent production tasks.

In the choice of cutting, we also refer to the spindle speed, feed, and cutting depth of these three indicators for evaluation, while we also take into full account the cost of processing parts, and strive to select the lowest cost and the best cutting results, to ensure that the milling efficiency and quality of work.

CNC milling route selection and arrangement

1. Division of the processing stage

Due to the characteristics of the milling process and the actual requirements of the parts process, we generally divide the parts into two stages, the first stage for the roughing stage, the purpose of which is for the cutting allowance; and the second stage for the fine machining stage, this stage of the operation is strictly based on the drawings and the requirements of the work process for processing, to fully ensure the quality of processing.

2. Arrangement of machining sequence

Usually, when we arrange the machining sequence, we should follow the principles of roughing before finishing, face before the hole, and base surface first, that is to say, we should carry out roughing before finishing; carry out flat surface machining before slot hole machining; and we should also process the side as a reference first, that is, the side without slot hole.

3. Decentralization and Concentration of Work Processes

After determining the first two tasks, we should also pay attention to the issue of decentralization or several kinds of processes.

The so-called process decentralization refers to the process of machining parts into many processes, so that the content of each process will be very little, while the process route will be very long, the advantage is simple and easy to adjust the operation, while it is the most reasonable choice of cutting amount, but to spend more resources;

While the process is focused on the process of processing parts to several processes, its advantage is to save resources and reduce costs, while the efficiency of the work is also improved, it is a very complex structure, and the preparation process is complex and not easy to adjust.

CNC milling CNC programming

The CNC machining preparation stage is the most important content is the work of CNC programming it is also from the parts of the drawing design stage to get all the CNC machining program of the whole process, mainly including the analysis of the parts drawings, to determine the process; preparation of CNC machining program;

Proofreading program; calculating the tool path, determining the tool position data; preparation of control media; and the first piece of test cutting, and so on.

Typically, we divide CNC programming into two main categories, namely manual programming and automatic programming.

The so-called manual programming refers to the programming of all stages that are manually completed, programmers use ordinary computing tools, apply various types of mathematical methods, manually calculate tool trajectory, and the preparation of instructions, Manual programming has obvious advantages, such as applicability, simple operation and easy to master, etc., but due to the complexity and the amount of calculation of the limitations of this type of programming method is generally only suitable for However, due to the limitation of its complexity and calculation volume, this type of programming method is generally only applicable to the programming of programs of medium complexity or less than medium complexity with a small amount of calculation.

Automatic programming refers to the use of a variety of computer software to prepare the CNC machining program process, this type of programming method is simpler, the operator only according to the requirements of the drawing of the processed parts, the application of CNC language, the subsequent calculation of the numerical value as well as post-processing and other work is done by the computer, in the completion of the machining of the parts after the preparation of the program list, the operator will be these machining program list input to the CNC machine tools, so that CNC machine tools can be completed, and then the machine can be used to complete the process. So that the CNC machine can complete the processing of parts.

Through the above discussion, we on CNC milling process analysis, CNC milling in the positioning and clamping, CNC milling in the selection of tools and cutting dosage, CNC milling in the selection and arrangement of routes, as well as CNC milling CNC programming five aspects of the content of a detailed analysis and discussion.

In the process of CNC machine milling process preparation, all the links are essential, the process preparation personnel must seriously and carefully treat each link, do a good job on the milling process analysis, seriously complete the CNC milling process in the positioning and clamping work, select the most appropriate cutting amount, cutting tools, and machining routes, but also to choose a reasonable CNC programming methods, to truly ensure the quality of the workpiece manufacturing, CNC milling processing, CNC milling processing, CNC programming, CNC programming. CNC milling can continue to be widely used in China’s manufacturing industry to ensure the quality of the workpiece.