Mechanical parts and auxiliary devices are important components of CNC machine tools. Among them, the mechanical part mainly includes: the machine tool spindle part, the employer screw nut pair, the track light. The auxiliary devices mainly include: CNC indexing head, automatic tool changer, hydraulic pressure system and cooling lubrication device. Therefore, one of the contents of the entire maintenance and maintenance of CNC machine tools during daily maintenance and maintenance.
1. Maintenance and Maintenance of Mechanical Parts The maintenance and maintenance of the mechanical parts of CNC machine tools mainly include the maintenance and maintenance of the machine tool spindle components, feed transmission mechanisms, and guide rails.
1.Maintenance and Maintenance of Spindle Components Spindle components are an important part of the mechanical parts of CNC machine tools, consisting mainly of spindles, bearings, accurate stopping of spindles, automatic clamping and chip removal devices. The lubrication, cooling and sealing of the spindle components of numerically controlled machine tools are a few issues that are worthy of attention during the use and maintenance of machine tools.
First of all, a good lubrication effect can reduce the operating temperature of the bearing and prolong its service life. For this reason, it should be noted that during operation and use, grease and oil are circulated and lubricated at low speed, and oil mist and oil-gas lubrication are used at high speed. However, when using grease lubrication, the spindle bearing is usually filled with 10% of the space volume of the bearing. Do not fill it with any amount of grease. This will increase the spindle heat. For the oil circulation lubrication, it is necessary to check the spindle lubrication thermostatic mailbox every day during operation to see if the oil quantity is sufficient. If the oil quantity is not enough, add the lubricant immediately; at the same time, check whether the lubricant temperature range is appropriate.
In order to ensure the spindle has a good lubrication, reduce friction and heat, but also can take away the heat of the spindle assembly, usually using a circulating lubrication system, using a hydraulic pump strong oil lubrication, the use of oil temperature controller to control the tank fluid temperature. High-grade CNC machine tool spindle bearings are lubricated with a high-grade grease sealer, which can be used for 7-10 years each time. The new lubrication and cooling method not only reduces the temperature rise of the bearing, but also reduces the temperature difference between the inner and outer rings of the bearing and ensures that the main shaft has little thermal deformation.
There are two common spindle lubrication methods. The oil-air lubrication method is similar to the oil mist lubrication method. However, the oil mist lubrication method continuously supplies oil mist, while the oil-air lubrication is the timing of quantitatively sending the oil mist into the bearing gap. Lubrication of the oil mist avoids too much oil mist and pollutes the surrounding air. The injection lubrication method uses a constant flow with a large flow rate to inject the spindle bearings to achieve lubrication and cooling purposes. Here the larger flow injected oil must be drained by the drain pump instead of the natural backflow. At the same time, a dedicated large-capacity, high-precision temperature-controlled mailbox is also used, and oil temperature changes are controlled within 5°C.
Second, the cooling of the main shaft components is mainly to reduce the bearing heating and effectively control the heat source.
Third, the seal of the main shaft components not only prevents dust, chips, and cutting fluid from entering the main shaft components, but also prevents leakage of the oil. The seals of the main shaft components are contact and non-contact seals. For contact seals with felt rings and oil-resistant rubber seals, check for ageing and damage. For non-contact seals, to prevent leakage, it is important to ensure that the return oil can be drained as soon as possible, and to ensure the smooth return hole. .
2. Maintenance and maintenance of feed transmission structure The electromechanical components of feed transmission mechanism mainly include: servo motor and detection element, deceleration mechanism, ball screw nut pair, screw bearing, moving parts (worktable, spindle box, column, etc.) ).
(1) Adjusting the axial clearance of the ball screw nut The ball screw nut has strict requirements on the axial clearance in addition to the precision of the feeding motion in one direction, so as to ensure the reverse transmission accuracy. Therefore, in the operation and use, it should be noted that the axial clearance caused by wear of the screw nut pair is eliminated by adjusting method. Double nut gasket type anti-backlash, double nut thread type anti-backlash, tooth-type anti-backlash.
(2) Daily inspection of the ball screw nut couple seal and lubrication The daily inspection of the ball screw nut couple seal and lubrication is a problem that we should pay attention to during operation and use. For the screw nut seal, it is necessary to check the seal ring and protective sleeve to prevent dust and impurities from entering the ball screw nut pair. Lubrication of the screw nut is regularly lubricated if grease is used. If oil is used, pay attention to oiling through the oil hole.
3. Maintenance and Maintenance of Machine Tool Guides The maintenance and maintenance of machine tool guides are mainly the lubrication of guide rails and the protection of guide rails.
(1) Lubrication of the guide rail The purpose of the guide rail lubrication is to reduce frictional resistance and frictional wear in order to avoid creeping at low speed and to reduce temperature rise at high temperatures. Therefore, the lubrication of the guide rail is very important. Lubricating oil is used for sliding guide rails, and lubricating oil or grease can be used for rolling guide rails. Check the amount of oil in the guide rail lubricant tank. If the amount of oil is not enough, you should immediately add the lubricant; at the same time, check whether the lubricant pump can be started and stopped regularly, and check whether the lubricant can be provided when the timing starts. (2) Protection of the guide rail In operation and use, care should be taken to prevent chips, abrasive particles, or chip liquids from falling on the surface of the guide rail. Otherwise, the wear of the guide rail will be aggravated, scratched, and rusted. To this end, we must pay attention to the daily inspection of the guide rail protection device to ensure the protection of the guide rail.
4. Maintenance and maintenance of the rotary table The maintenance and maintenance of the auxiliary devices of the CNC machine tools mainly include the maintenance of the CNC indexing head, the automatic tool changer, and the hydraulic hydraulic system.
1. Maintenance and Maintenance of CNC Indexing Head CNC indexing head is a common accessory for CNC milling machines and machining centers. Its role is to perform rotary indexing or continuous rotation feed motion in accordance with the instructions of the CNC device so that the CNC machine tool can complete the instructions. The accuracy of processing, therefore, should pay attention to the correct operation and use according to the requirements and operating instructions of the digital indexing head in operation.
2. Maintenance and maintenance of automatic tool changer When the automatic tool changer is used, the machining center is different from other special structures of CNC machine tools. It has the function of automatically changing the required tool according to the processing technology requirements to help the CNC machine tool to save the auxiliary time, and to meet the multiple process and step processing requirements in a single installation. Therefore, during operation, it is necessary to pay attention to checking whether the operation of the mechanical structure of each component of the automatic tool changer works normally and whether there is an abnormal phenomenon; check whether the lubrication is good, and pay attention to the reliability and safety inspection of the tool change.
3.Maintenance and maintenance of hydraulic system (1) Periodically inspect, filter and replace the oil in the mailbox;
(2) Check the working performance of the cooler and heater and control the oil temperature;
(3) Regular inspection of replacement seals to prevent leakage of hydraulic system;
(4) Regularly check the cleaning or replacement of hydraulic parts, filter elements, and regularly check the cleaning of mailboxes and pipes;
(5) Strictly implement the daily inspection system to check whether the system's leakage, noise, vibration, pressure, and temperature are normal.
4.Maintenance and maintenance of air pressure system (1) Use proper filter to remove impurities and moisture in compressed air;
(2) Check the amount of oil supplied by the lubricator in the system to ensure that there is a proper amount of lubricating oil in the air to lubricate the pneumatic components and prevent air leakage and component malfunction due to rust and wear;
(3) Keep the sealing of the pneumatic system and check the replacement of seals regularly;
(4) Pay attention to adjusting working pressure;
(5) Check regularly to clean or replace pneumatic components and filter elements.
