Vertical machining center 640 programming is a skill that a qualified machining center operator must master, but programming is also a problem that plagues many friends.
1. Basics of CNC Programming
1. The role of NC program editing-why do you want to program NC program?
A CNC machine tool is an automated machine tool. During processing, according to the requirements of the workpiece pattern and the processing process, the movement, speed and sequence of actions, spindle speed, spindle rotation direction, tool head clamping, The cutter head loosening and cooling operations are compiled into a program list in the form of a prescribed numerical control code and input into the special computer of the machine tool. Then, the numerical control system compiles, calculates, and logically processes the input instructions, outputs various signals and instructions, and controls each part to process various workpieces of different shapes according to the prescribed displacement and sequential actions. Therefore, the programming of the program has a great influence on the effectiveness of CNC machine tools.
2. The standard of NC program-what does NC program look like?
The CNC machine tool must input the instruction codes representing various functions into the CNC device in the form of a program, and the CNC device performs arithmetic processing, and then sends out pulse signals to control the operation of the various moving parts of the CNC machine tool to complete the cutting process of the parts. At present, there are two standards for CNC programs: ISO of the International Organization for Standardization and EIA of the American Electronics Industry Association.
3. Machining coordinate system and mechanical coordinate system-are the two the same thing?
Most vertical CNC machining centers or CNC machine tools stipulate: Assuming that the workbench is not moving, the operator is standing in front of the machine tool to observe the movement of the tool. The tool moves to the right as the X axis, inward as the Y axis, and upward as the Z axis. Carr coordinate system. The zero return of each axis of the machine tool is at a certain fixed point, which is the mechanical zero point of the machine tool.
The zero point determined at the position where the workpiece is more convenient for alignment during programming is the programming zero point. The workpieces of the mold factory are mostly rectangular parallelepipeds. Generally, the zero point is selected at the symmetry center of the workpiece, which is also called the "four-sided centering" position, which is the zero point of the X and Y axes, and the Z value is mostly set at the highest surface.
4. Program code-what are the commonly used codes?
In many machine tool systems, the currently commonly used CNC program code is G code.
Two, programming software introduction
1. How to compile complex programs? What are the programming software? Which one is easy to use?
With the advancement of technology, 3D CNC programming generally rarely uses manual programming, but uses commercial CAD/CAM software.
CAD/CAM is the core of a computer-aided programming system. Its main functions include data input/output, calculation and editing of processing trajectories, process parameter settings, processing simulation, post-processing of numerical control programs, and data management.
At present, in our country, the software with powerful CNC programming function that is popular among users includes Mastercam, UG, Cimatron, PowerMILL, CAXA, etc. The principles of NC programming, graphics processing methods, and processing methods are similar for each software, but each has its own characteristics. Because every kind of software is not perfect, users must not only learn its strengths, but also understand their weaknesses in depth, so that they can be used freely.
2. Introduction to the control panel of a typical CNC machine tool
As a CNC programmer, you must first understand how the program you have compiled runs, so it is necessary to learn the operation of a certain type of CNC machine tool. If possible, it is best to be able to operate the machine correctly to a certain level, and then Learn CNC programming, so that the programmed program can be realistic. Commonly used typical CNC systems include FANUC (Japan), SIMEMENS (Germany), FAGOR (Spain), HEIDENHAIN (Germany), MITSUBISH (Japan) and other companies' CNC systems and related products, which occupy a dominant position in the CNC industry.
Third, the essentials and precautions for the operation of CNC machine tools
(1) The power is turned on. To check whether the electric meters are normal, whether the barometer is normal, whether the oil-water meter is normal. If there is no problem, press the POWER ON button to turn on the power. After a few seconds, the machine will self-check and the CRT will display the coordinates. If an alarm message appears, analyze and eliminate it by yourself first. If it cannot be solved, report it to the superior immediately and ask a professional to deal with it. If normal, proceed to the next operation.
(2) The machine tool returns to the reference zero point, manually or automatically, so that the machine tool can run normally.
(3) Analyze the NC program sheet and compare the programming graphics to understand the overall tool movement, tool setting mode and clamping mode; prepare tools, measuring tools and fixtures; clamp the workpiece on the machine tool as required.
(4) The workpiece is centered and corrected, and the mechanical value of the zero point of the workpiece coordinate system is input into G54, G55 and other memories.
(5) Load the tool for tool calibration, and input the length compensation value to the H value.
(6) Copy the NC program and modify the head and tail of the program according to the existing tool number and compensation number.
(7) Turn on high-pressure air blowing.
(8) The NC program is transmitted through the DNC network in the DNC state.
(9) At the beginning, feed the tool slowly, wait for the tool to cut into the workpiece, and adjust the feedrate override switch to the normal speed when the cutting is stable and normal. Adjust the speed switch to make the sound loud and smooth cutting. Determine the appropriate speed S and feed F according to the requirements, so that the cutting volume per blade can meet the requirements of reasonable and efficient.
(10) If processing steel parts, pay close attention to the degree of wear of the blade when roughing, and adjust or replace in time if there is a problem.
(11) To have an understanding of the machine tool accuracy, tool rotation accuracy and machining error you are using, and to communicate closely with the programmer, so that enough margin is left when the knife is lighted.
(12) After the processing is completed, the measurement should be carried out on the machine tool against the programmed graphics. If it is unqualified, analyze the reason. It is necessary to reprogram by adjusting the programming margin or adjust the compensation number and then process until it is qualified. Remove it after passing the test. Clean the machine and prepare to process the next one.
4. Advice for beginners
To learn the knowledge that UG CNC programming should have—I don’t have a high level of education, can you learn CNC well?
CNC programming is a comprehensive skill. To learn well, enthusiasm alone is not enough. You must also learn a certain basic knowledge beforehand, so that you can truly understand and apply it flexibly to actual work.
To be able to use UG or other software for basic 3D drawing and basic operations. Because to optimize the tool path, it is necessary to organize graphics, modify graphics, and sometimes increase or decrease auxiliary lines and auxiliary surfaces.
Basic knowledge of machining and drawing. This is the basic knowledge to do a good job in this industry, I suggest you learn while working.
