Maintenance of equipment

Correct maintenance of CNC equipment

(1) Workplace selection of CNC machine tools:

1. Avoid direct sunlight and heat radiation, avoid too humid or excessive dust, try to use in air-conditioned environment, keep room temperature around 20 °C. Because the country is in a temperate climate, affected by the monsoon, and the temperature difference is large, for high precision and expensive CNC machine tools, it should be used in air-conditioned rooms.
2. Avoid places with corrosive gases. Corrosive gases tend to deteriorate electronic components, cause poor contact, or cause short-circuiting of components, affecting the normal operation of the machine.
3. Keep away from equipment with high vibration (such as punching machines, forging equipment, etc.). For high-precision machine tools, anti-vibration measures (such as anti-vibration ditch) should also be used.
4. Keep away from strong electromagnetic interference sources to make the machine work stable.

(2) Equipped with high-quality programming, operation and maintenance personnel:

CNC machine tools are typical mechatronics products that integrate advanced technologies such as computer technology, automatic control technology, precision measurement technology and machine tool design. The control system is complex and expensive. Therefore, the personnel equipped must have the following basic qualities: First, they should have a high degree of responsibility and good professional ethics. Second, it has a good knowledge and a good working habit of diligent learning, good thinking, and more hands-on. The person in charge of routine maintenance must not only master computer principles, electronic and electrical technology, automatic control and electric drag, measurement technology, mechanical transmission and cutting process knowledge, but also have a certain English foundation and strong hands-on practical ability. In order to fully control the CNC machine tools, so to cultivate students' comprehensive quality and job skills, is the basic guarantee for the good operation of the college numerical control equipment.

(3) Establish a maintenance system for CNC equipment:

There are many types of CNC machine tools, and various types of CNC machine tools have different characteristics due to their functions, structures and systems. The contents and details of its maintenance also have its own characteristics. It is necessary to formulate and strictly define the daily maintenance system according to the type, model and actual use of the machine, and with reference to the requirements of the machine manual. Daily maintenance work can be divided into daily inspection, weekly inspection, semi-annual inspection and irregular inspection. Check the content for regular inspection. For some frequently moving elements, components (whether mechanical transmission parts or drive control parts) should be used as regular inspection objects. If repeating the positioning accuracy, it is necessary to make a key check before each skill appraisal to ensure that students get better dimensional accuracy in the assessment. In addition, for the storage (CMOS) power supply battery, the new battery should be replaced when the CNC system is powered on to ensure that the storage parameters are not lost and the CNC system is operating normally.

(4) Do a good job in the maintenance of the numerical control device:

1. Do a good job in machine troubleshooting.
Once an alarm occurs on the machine, the machine has failed or is in an abnormal state. You should first find out the cause before you can continue to run. Once the CNC machine tool is shut down, it directly affects the internship teaching plan, and the consequences are very serious. Therefore, maintenance personnel must have high-tech and rigorous work style, carefully make maintenance records, scientifically analyze the causes of failures, and find the root causes and laws of faults, thus eliminating machine faults.
2. Pay attention to the dustproof of the numerical control device.
First of all, in addition to the necessary maintenance, the door should be opened as little as possible, because the door is often open, so that dust, oil mist and metal powder floating in the air can fall on the printed circuit board and electrical connectors, which is easy to cause. Insulation resistance between components is reduced, causing malfunctions and even component damage, so it is important to strengthen the sealing management of CNC cabinets and power cabinets. Some CNC machine tool spindle speed control units are installed in the power cabinet. The tightness of the power cabinet door is a cause of damage to the electrical components and is a cause of malfunction of the CNC system. Secondly, some circuit boards and connectors that have been contaminated by external dust and oil mist can be sprayed with a special electronic cleaner.
3. pay attention to the heat dissipation of the numerical control device.
Every cooling fan on the CNC system cabinet should be checked every day for normal operation. Check whether the air duct filter is blocked every six months or quarterly depending on the working environment. If there is too much dust accumulation on the filter, it needs to be cleaned up in time. Otherwise, the temperature inside the cabinet of the CNC system will be high (it is generally not allowed to exceed 55 °C), resulting in overheating alarm or unreliable operation of the CNC system.

(5) The doors of the CNC cabinet and the power cabinet should be opened as little as possible:

Because the air in the machine shop usually contains oil mist, dust and even metal powder. Once they fall on the printed circuit or electrical device in the CNC system, it is easy to cause the insulation resistance between components to drop, and even cause damage to components and printed circuits. Some users in the summer in order to overload the CNC system for a long time, open the door of the CNC cabinet to dissipate heat, this is an indispensable method, which will eventually lead to accelerated damage of the CNC system. The correct way is to reduce the external ambient temperature of the CNC system. Therefore, there should be a strict regulation, unless the necessary adjustments and repairs are made, it is not allowed to open the door casually, and it is not allowed to open the door during use.

(6) Maintenance of the CNC system when not in use for a long time:

In order to improve the utilization rate of the numerical control system and reduce the failure of the numerical control system, the numerical control machine tool should be used at full load, instead of being idle for a long time. For some reason, when the numerical control system is idle for a long time, in order to avoid damage of the numerical control system, the following two should be noted. point:
1. It is necessary to energize the CNC system frequently, especially in the rainy season with high ambient humidity. When the machine lock is not moving (ie, the servo motor does not turn), let the CNC system run empty. The heat of the electrical components itself is used to dissipate the moisture in the numerical control system, and the performance of the electronic device is ensured to be stable and reliable. It has been proved that in areas with high air humidity, frequent power supply is an effective measure to reduce the failure rate.
2. CNC machine tools adopt DC feed servo drive and DC spindle servo drive, the brush should be taken out from the DC motor to avoid corrosion of the commutator surface due to chemical corrosion, resulting in deterioration of commutation performance, even the whole set The motor is damaged.

(7) Maintenance of cutting tools and cutting oil:

1. Tool performance is a fundamental factor affecting machining efficiency, machining quality and tool durability. During maintenance, the data of the tool and the degree of wear should be detected by observation and equipment, and the error of the tool parameters can be corrected in time to prevent errors.
2. The performance of cutting oil is the necessary condition for the performance of the tool. The cutting oil with excellent performance can effectively protect the tool, prevent the generation of cutting edge and improve the surface finish of the workpiece. Therefore, the cutting oil should be inspected during regular maintenance. If there is a change in viscosity, gelation, sedimentation, etc., it should be replaced in time. In addition, professional equipment can be used for sampling inspection if conditions permit.