Views: 0 Author: Site Editor Publish Time: 2022-06-13 Origin: Site
1. Programming skills
1) The processing sequence of parts:
First drilling after the flat end (this is to prevent the shrinkage of the material when drilling); First rough car, and then fine car (this is to ensure the accuracy of parts);
Machining the large tolerance first and the small tolerance finally (this is to ensure that the surface of the small tolerance size is not scratched and prevent parts from deformation).
2) Choose reasonable speed, feed and cutting depth according to the hardness of the material. My personal summary is as follows:
a） Carbon steel material selection of high speed, high feed, large cutting depth. Such as: 1Gr11, select S1600, F0.2, cutting depth 2mm;
b） Hard alloy choose low speed, low feed, small cutting depth. For example: GH4033, S800, F0.08, cutting depth 0.5mm;
c） Titanium alloy choice of low speed, high feed, small cutting depth. For example: Ti6, S400, F0.2, cutting depth 0.3mm.
2. Knife skills
The knife is divided into knife instrument and direct knife. Most lathes do not have the tool instrument, for direct tool, the following tool skill for direct tool. First choose the right end center of the parts for the tool point, and set as zero, the machine tool back to the origin, each need to use the tool parts right end center for zero tool; Input Z0 click measuring tool in contact with the right end, cutter knife repairing values will automatically record the measured values, which means that the Z axis to the knife to the good, X knife to try to cutting knife, with less tool cart cylindrical parts, measured by a car cylindrical numerical x20 (such as X 20 mm) as input, click on the measurement, knife repairing value will automatically record the measured values, Now the X-axis is right; This tool alignment method, even if the machine power, call after the restart will not change the value of the tool, can be applied to large quantities of long time production of the same part, during the closing of the lathe does not need to re-alignment.
3. Debugging skills
Parts in the program, after the good knife need to carry out trial cutting debugging, in order to prevent errors in the program and the error of the knife, causing the crash accident, we should be advanced line travel simulation processing, in the machine tool coordinate facing the tool to the right overall translation parts 2 -- 3 times the total length; Then began to simulate processing, simulation processing after the completion of the confirmation of the program and the knife, and then began to process parts, the first part of the processing is completed, the first self-check, confirmed qualified, and then find full-time inspection, full-time inspection confirmed qualified after this means the end of debugging.
4. Finish the machining of parts
Parts after completion of the first trial cut, be about to batch production, but the first thing that is not equal to the whole batch of qualified parts will be qualified, because in the machining process, due to the difference of processing material can make the cutting tool wear, processing of soft material, tool wear is small, hard processing material, tool wear is fast, so in the process of machining, to regular amount of regular inspection, timely repair value increase and decrease the knife, Ensure the parts are up to standard.
In short, the basic principle of processing: first rough processing, remove the excess material of the workpiece, and then fine processing; Vibration should be avoided in processing; Avoid thermal denaturation of workpiece processing, vibration caused by many reasons, may be too much load; It may be the resonance of the machine tool and the workpiece, or it may be the insufficient rigidity of the machine tool, or it may be caused by the passivation of the tool. We can reduce the vibration by the following methods; reduce the lateral feed and machining depth, check whether the workpiece is firmly clamped, increase the tool speed, which can reduce the speed of resonance, in addition, check whether it is necessary to replace a new tool.
In addition, in order to safely operate CNC machine tools, prevent machine collision, I have the following experience:
Often hear others say, do not touch the machine tool, will not learn machine tool operation, this is a very wrong and harmful understanding, machine tool collision on the accuracy of machine tool is very damaging, for different types of machine tool impact is not the same, generally speaking, for the rigidity of the machine tool is not strong.
Once the machine tool collision, the impact on the accuracy of the machine tool is fatal. So for high precision CNC lathes, collision must be absolutely eliminated, as long as the operator is careful and master a certain anti-collision method, collision is completely preventable and avoided.
The main reasons for the collision: first, the diameter and length of the tool input error; Second, the size of the workpiece and other related geometric dimensions input errors and the initial position of the workpiece positioning errors; Third, the workpiece coordinate system of the machine tool is set incorrectly, or the zero point of the machine tool is reset in the process of processing, and the change occurs. Machine tool collision mostly occurs in the process of machine tool rapid movement. At this time, the harm of the collision is also the largest, which should be absolutely avoided.
So the operator should pay special attention to the machine tool in the initial stage of the execution of the program and the machine tool in the replacement of the tool, at this time once the program edit error, the diameter and length of the tool input error, then it is easy to collision. At the end of the program, the NC axis back tool action sequence is wrong, then collision may also occur. In order to avoid the collision, the operator in the operation of the machine tool, to give full play to the function of the five senses, observe the machine tool has no abnormal action, there is no spark, there is no noise and abnormal ringing, there is no vibration, there is no coke taste.
Abnormal conditions should be found immediately stop the program, machine tool to solve the problem, machine tool to continue to work, in short, to master the operation skills of CNC machine tools is a step-by-step process, and cannot be accomplished overnight. It is built on mastering the basic operation of machine tools, basic machining knowledge and basic programming knowledge. Numerical control machine tool operation skills are not immutable, it is the operator to give full play to the imagination and hands-on ability of the organic combination, is an innovative labor.