CNC manual programming methods and steps
source：未知
Wanbang Hardware believes that the main contents of NC programming are: analyzing the part pattern to determine the process, numerical calculation, writing the processing program, proofreading program and the first piece of trial cutting.
The specific steps of programming are as follows:
1. Analyze the pattern and determine the process
The parts processed by the craftsman are the part drawings. According to the part drawing, the shape, dimensional accuracy, surface roughness, workpiece material, blank type and heat treatment condition of the part can be analyzed, and then the machine tool and the tool are selected to determine the positioning clamping device, the processing method, the processing sequence and the cutting amount. size. In the process of determining the process, the command function of the CNC machine tool used should be fully considered, and the performance of the machine tool should be fully utilized to achieve a reasonable processing route, a small number of passes and a short processing time. In addition, you should also fill in relevant technical documents, such as CNC machining process cards, CNC tool cards, and route maps.
2. Calculate the coordinate value of the tool path
According to the geometry of the part drawing and the programmed coordinate system, the motion track of the tool center is calculated, and all the tool position data is obtained. Generally, the numerical control system has the functions of linear interpolation and circular interpolation. For the contour processing of flat shapes with simple shapes (such as parts composed of straight lines and circular arcs), only the starting point, end point and arc of the geometric elements need to be calculated. The center of the circle (or the radius of the arc), the intersection of the two geometric elements, or the coordinates of the tangent point. If the CNC system has no tool compensation function, the coordinate value of the motion path of the tool center is calculated. For parts with complex shapes (such as parts consisting of non-circular curves and curved surfaces), straight lines (or arc segments) are required to approximate the actual curve or surface, and the coordinate values ??of the nodes are calculated according to the required machining accuracy.
3. Write a part program
According to the machining route, the tool movement trajectory data and the determined process parameters and auxiliary actions are calculated. The programmer can write the machining program of the parts one by one according to the function instructions and the program segment format specified by the numerical control system. At the time of writing, it should be noted that: first, the normative nature of the program should be easy to express and communicate; secondly, on the basis of the full familiarity with the performance and instructions of the CNC machine used, the skills used in each instruction and the skills of the program segment preparation.
4. Enter the program into the CNC machine
The way to input the machining program into the CNC machine tool is: photoelectric reader, keyboard, disk, tape, memory card, DNC interface and network connected to the upper computer. At present, the commonly used method is to directly input the machining program (MDI mode) into the CNC machine program memory through the keyboard or transfer the machining program to the program memory of the CNC machine tool through the communication interface between the computer and the numerical control system, and the machine operator processes the parts according to the parts. Need to be called. Now some new CNC machine tools have been configured with large-capacity memory card storage processing programs, which are used as CNC machine program memory, so the NC program can be stored in the memory card in advance.
5. Program verification and first piece trial cutting
The NC program must be verified and tested before it can be formally processed. On the CNC machine with graphic simulation function, it can perform graphic simulation processing to check the correctness of the tool path, and can perform the dry running test on the CNC machine without this function. However, these methods can only check whether the tool trajectory is correct, can not find the tooling error, due to improper tool adjustment or machining error caused by some calculation errors and the machining accuracy of the parts, so it is necessary to pass the first part of the part processing. This important step of cutting. When machining errors are found or the drawings are not met, the cause of the error should be analyzed in order to modify the machining program or take measures such as tool size compensation until the parts required by the drawings are processed. With the development of CNC machining technology, advanced CNC machining simulation methods can be used to check the NC machining program.
