For these beginners who CNC machine tools, CNC machine operator to master certain skills are very important. On the one hand they can avoid machine crashes, resulting in damage to the machine; the second is in a short space of time, can rapidly improve the operator's CNC machine operator skills, competent at their jobs. Here are some theoretical knowledge of CNC machine operating skills, and hope to have some reference significance for just engaged in CNC machine operator is. First, the operator of the CNC machine operator required to have a comprehensive understanding.
Learn the mechanical structure of the machine: To find the machine mechanical structure composed; to master the machine shaft distribution; but also to firmly grasp the positive and negative directions of each NC machine tool axes; to master the function and use of the various components of the machine, such as a simple pneumatic system principle and function, a simple hydraulic system works and functions; in addition to master the machine each auxiliary unit works and functions, such as the magazine, the cooling unit, voltage regulator, electrical cabinets, etc. cooler unit work principle, function and use, as well as various security locks the machine works, function and use.
Firmly grasp the machine each operation button functions: to know how to perform procedures; how to pause the program after checking workpiece machining status after resume a suspended state continue program execution after how to stop the program; how to change the program after the execution of the program, and so on.
Learn what you operate the machine what operating system; a simple understanding of the principles and working methods of numerical control system; the system uses what working language, language software tools used in processing and use. If the operator did not understand the language or understand the language of the vocabulary, you need professional training, in training need to carefully take notes, software tools for each word represents what Chinese mean, you must remember to die hard carried back to master, so in order for the proper use of the machine after the job.
In addition, the operator need training on general operation of the alarm statement to learn to master, to know the Chinese are representative of what that means, how to solve the problem, how to eliminate false alarms. In addition to the operator, if there is energy and ability allows it, you can learn to master the language of this kind, then the future improve machine operating skills of great help.
Secondly, we must master the manual control or automatic operation of CNC machine tools, proficiency in movement control of each machine axis CNC.
The operator must meet practice makes perfect jingjie, it can under no circumstances can do acting freely; only in the face of a collision or fault conditions, the operator can correct and timely deal with the problem, the operator will form a conditioned reflex take decisive brake means.
In addition the operator of the CNC machine tools to be very familiar with the program; what kind of processes and operations, the machine should have what kind of action, must be very familiar with. When the machine execute the program, you can know the correct operation of the machine for the first time, the need to take measures to brake. In addition, each novice operator at the beginning of the operation of the machine more or less have some fear, fear of the machine tool collision occurs, the collision occurred. The operator then only after mastering the operation of CNC machine tools to overcome similar fears
Third, to master the program editor, compensation diameter and length of each process parameters and tool compensation or wheel.
First, you want to be trained to master the operation of CNC machine tools, programming languages, programming methods and parameters Compensation. Now most advanced CNC machine tools are equipped with simulation programming or PC workstation. So beginners can start with editing software and machine cutting simulation study on the workstation.
Learning programming, do not focus only on the simulation results, more importantly, to learn the simulation process, and to understand the workpiece need to use what tools or grinding wheels, machine tool CNC axes by what trajectory complete machining; machine a concrete step in the implementation process, position and direction of movement of the relevant components in the machine; note that in the implementation of the direction of movement of each axis machining and cutting directions, including how to feed, how to retract, note the various stations in the machine when fast forward velocity and displacement steps, each step of the work into the velocity and displacement. After the collision or cause the actual processing time, or; in the process through simulation software, pay attention during the simulation All parameters must be entered correctly, not because you are free analog input sloppy, this may appear incorrect processing simulation results Part scrapped. If the simulation software has the function of anti-collision test, then you should use this function to check the correctness of programming.
In addition, the operator needs special attention: the results of a simulation process is theoretical and does not represent actual machine in the cutting process will not be a collision, it does not mean you can process the certified product. The simulation program is designed to save time and improve the actual machine utilization, and reduce debugging time when machining a workpiece, do not represent actual parts processing. Complete and perfect workpiece is CNC machine operator's wisdom and sweat inseparable. Point 4, the actual process of working skills, ready to work conscientiously, first read drawings, confirmed to be processed
Position of the workpiece, the workpiece parts to confirm the accuracy of tolerance, and then edit the machining program. Workpiece and tool or grinding wheel to the required processing is ready, the process requires testing equipment are ready, the process requires an auxiliary tooling and fixtures are ready.
The first machining a workpiece, the machine should use the single-step test cutting working state. When the machine program every call a new tool or grinding wheel should be preceded by the knife, to check whether correct operation of the program.
Try to take a fixture to complete the workpiece when the workpiece; if you need to measure or other reasons workpiece clamping the second, then we must ensure that the first and second clamping fixture positioning and machining datum unification . If you take the machine automatically positioning device, then the need to maintain the consistency of measurement speed automatic measuring system. When machining accuracy of the workpiece is detected, it is possible to complete the machine, thus reducing the positioning error of the second fixture. In addition, some parts of the workpiece in the machine, the higher its precision dimensional tolerances, the operator after each processing is completed, you need to check the accuracy, inspection and approval and then go to the next position of a workpiece; if the workpiece shape on a part of the process is composed of two or more synthetic directions, each direction of the process will affect the position or shape site geometry tolerances, then the process should be the first workpiece machining accuracy of a less affected direction, then the workpiece tolerances higher direction, and finally repeated processing, and finally approaching the required precision. If you use standard measuring instruments on the machine the workpiece can not be measured, but the work can not be measured is removed from the machine, or affect the machining accuracy of the workpiece, you can use a special card, plug, and other means to gauge detect if the machine itself, the software with measurement functions, you can use the machine to measure the workpiece itself. After the completion of the entire machining the workpiece, then the workpiece comprehensive testing.
For a batch processing of the workpiece. After the initial time debugging is complete, we need to optimize the machining program. The basic principles of optimization are as follows: the premise of ensuring the quality of processing, optimization of cutting parameters, such as speed work into the tool or wheel speed, lateral feed rate, depth of processing, and so on; optimization process steps to optimize machining datum, improve processing efficiency, the use of high life tool or grinding wheel, grinding wheel to reduce the number of tool changes or frequency; mathematical model reasonable processing program, effective and reliable editing program, a reasonable set of rough finishing margin and the number and use of an appropriately shaped tool or wheel, to improve efficiency processing quality assurance tool has a more significant effect.
To guarantee finishing of workpiece should note the following: To the machine tool machining heat engine for some time, to maintain thermal balance machine tool mechanical axis during operation, try to remain stable workpiece temperature machining process, and try to keep working head, spindle, screw rails, grating, grinding wheel or tool chuck connecting rod hot and cold balance. If the machine is equipped with cooling oil and coolant to keep its temperature constant, the coolant temperature is one of the important factors that affect the accuracy of the workpiece through the machine's cooling system to ensure a constant temperature of the coolant.
General factory night need to shut down, the next need to open the machine, so the machine before work every day, the need for a heat engine. In order to improve machine utilization, the existing two ways to achieve machining. First, after the power of the original program slightly xiugai, all processing steps to make a far compensation of the workpiece, the process, the machine changes the correction value at the time of machining according to the measurement results, when the machine is in thermal equilibrium correction value may not need to be changed. Another method is, then the first workpiece tolerances of a large part of a period of time after start-up, and then after a period of time until the machine to reach thermal equilibrium, again on the workpiece machining tolerances required some higher position; or first with the machine after roughing, and other machine tools working to reach thermal equilibrium, and then finishing the workpiece. For having a multi-reference, there are many high precision size workpieces. So we should have a working definition of reference only one or two dimensions on the workpiece, but the size of high precision position, and a plurality of reference for the same size of the site, the site should be the highest precision machining, precision machining and then comparing low position. Because the machine when the workpiece machining precision parts prone to waste, the remaining parts of the work that you can not process, which saves processing costs. In short, the basic principles of processing: First roughing, remove the excess material of the workpiece and finishing; processing should avoid vibrations; avoid heat denaturation of the workpiece machining. Vibration caused by the occurrence of a number of reasons, may be the load is too large, it may be resonance machine and workpiece, or may be insufficient rigidity of the machine, it may be the tool or grinding wheel after passivation caused. We can reduce the vibration by the following method: reduced infeed volume and depth of processing to check whether workpiece clamping firm to improve speed or reduce the speed of the tool can reduce the resonance, the other to see if it is necessary to replace the new tool.
CNC machine operator for beginners often collide. Often heard people say, do not touch the machine, the machine operator will not learn, this is a very wrong and harmful awareness. The accuracy of the machine tool collision is great damage, for different types of impact tools are not the same. In general, the machine is not strong rigidity greater impact, the more rigid machine gantry structure, in the same impact force less affected. If the machine is too cantilevered structure, and the spindle is mounted on a rotary shaft of the machine structure, once the machine collision, then the accuracy on the machine is fatal. So for high-precision CNC machine tools, absolutely have to put an end collision. As long as careful operator and master certain anti-collision method, the collision is completely preventable and avoided. Perhaps the following tips to prevent the collision of CNC machine tools for beginners helpful.
The main reason for the collision occurred: First, the tool or grinding wheel diameter and length of the input error; the second is the initial position of the workpiece size and other relevant geometry input errors and workpiece positioning error; the third is the machine the workpiece coordinate system set incorrectly, or the machine is reset to zero in the process, and produce change. Machine tool collision occurs mostly in fast-moving process, which occurs when a collision hazard is also the largest, should be absolutely avoided. Therefore, the operator should pay special attention to the machine at the initial stage and the execution of the program in the machine tool or grinding wheel replacement time, this time once the program editing error, the tool or grinding wheel diameter and length of the input error, then it is easy collision. In the end phase of the program, retracting operation of each CNC axes in the wrong order, then a collision may occur. To avoid collision, the first time you use the tool and wheel, carefully carried the knife, not underestimate the problem. To avoid collision, the operator when operating the machine, facial features to fully observe any abnormal operation of the machine, with or without spark, with or without noise and unusual ring, with or without vibration, whether the burning smell. Abnormal situation should immediately stop the program until the issue is resolved after the machine, the machine can continue to work. At the same time before the operation, the operator should receive training in safe operation of the machine, the machine proper safety procedures for each type, the operator should be operating and safety training systems, in order to hold the machine on the job after training of qualified job card. Former staff should be aware of fire extinguishers position, and the operator to grasp the position of fire extinguisher method, the position of the machine pressure switch, the machine input power switch, hydraulic station location, because of grasp the emergency shutdown method for use grinder cooling oil fire extinguishers should be placed within three meters of the machine.
In short, to master the operating skills of CNC machine tools is a gradual process, and can not be done overnight. It is built on the basic operation of the machine mastered the basic machining knowledge and basic programming knowledge above. CNC machine operator skill is not static. It is a component of the operator is required to play an organic combination of imagination and ability, is the innovative labor.
