Introduction to CNC Machine Operation

Author: Ren Yizeng
Publisher:
Publish Date: 2003-12-01
Features: Numerical control machine tools integrate mechanical, electrical, and hydraulic systems, characterized by high technological and knowledge density. They are advanced machining equipment with a high degree of automation, complex structures, and high costs. To maximize their efficiency and minimize failures, daily maintenance is essential. While every numerical control machine tool will eventually wear out after long-term use, extending the service life of components, prolonging the wear cycle of mechanical parts, preventing accidental severe accidents, and ensuring the machine operates for extended periods are the objectives of preventive maintenance. Operators should be familiar with the operating environment and processing conditions of the machine and use the numerical control machine tool correctly according to the requirements of the machine and system manuals. This allows for a comprehensive understanding, proper use, and mastery of the machine, ensuring timely maintenance. The main maintenance tasks are as follows:
1. Selecting a suitable operating environment
The operating environment of a CNC lathe affects its normal operation, so the installation of the machine must strictly comply with the installation conditions and requirements specified in the machine manual.
2. Establishing strict operation and maintenance procedures
Since CNC lathes are highly automated equipment, improper operation can easily lead to accidents. Therefore, it is necessary to establish strict operation and maintenance procedures, prohibiting non-CNC machine tool operators or maintenance personnel from operating or maintaining the machine.
3. Developing a machine maintenance schedule, such as cleaning air filters, electrical cabinets, and printed circuit boards.
4. Maintaining idle CNC lathes
When a CNC lathe is idle, it should be frequently powered on, and the machine should be set to run in an idle state while locked. During the rainy season with high humidity, it should be powered on daily to utilize the heat generated by electrical components to drive away moisture inside the CNC cabinet, ensuring the stable and reliable performance of electronic components. Specific maintenance requirements for each CNC machine tool are detailed in the machine manual. Below, we introduce the general arrangement of periodic maintenance and inspections for CNC equipment.
### I. Daily Inspection
The user should pay attention to the following phenomena while operating the machine daily, maintaining the highest level of vigilance. If any abnormalities are detected, they should immediately investigate the cause or contact the machine manufacturer to jointly study and take action to resolve the issue.
1. Before startup
(1) Check if the power cables and all wire connections and pipe joints are damaged or poorly connected.
(2) Check if the oil level indicators for the tool changer and other lubricating oils are normal.
(3) Check if the cutting fluid tank needs to be refilled.
(4) Check if the air pressure is normal.
(5) Check for any oil leaks.
(6) Ensure all safety protection devices are functioning properly and that no personnel are in hazardous areas.
2. After startup
(1) Check if the spindle temperature is too high or if there are abnormal noises.
(2) Check if the electric lubrication pump is operating normally.
(3) Check if the machining program is complete.
(4) Check if there are missing or insufficient cutting tools.
(5) Keep the machine and the operator panel clean and dry.
(6) Check if the transformer is overheating.
(7) Check if the spindle blowing function is normal.
3. At the end of work
(1) Clean the spindle taper hole with a cleaning rod daily.
(2) Clean the chips on the three-axis clamps and the cutting fluid tank daily.
(3) Clean the debris on the tool holder at least once every 8 hours.
(4) Clean all axis motors daily.
(5) Clean the appearance before leaving work or handing over.
(6) Move the three axes to the middle of the travel range to maintain the workbench's balance accuracy.
(7) Perform rust prevention work on the workbench after removing chips.
(8) Check if all safety doors are closed.
(9) Check if the power switch is turned off.
(10) Check if the power supply switch is turned off.
### II. Regular Maintenance
1. Maintenance Precautions
(1) Ensure the safety of maintenance work. Electrical doors and covers should only be opened when necessary for maintenance.
(2) Do not use compressed air to clean the machine or other components. (If the environment is not clean enough, dust and metal chips may be blown into bearings or lubrication channels.)
2. Daily Maintenance Tasks
(1) Remove chips, dust, and debris from the workbench, base, and tool length measuring device.
(2) Remove all objects from the surface of the rails (uncovered parts).
(3) Clean the covers of all axes and their rails.
(4) Clean the taper bore inside the spindle.
(5) Clean all exposed electrical components and limit switches.
(6) Check the oil level in the central lubrication tank and the spindle lubrication tank and ensure it remains at the recommended level.
(7) Confirm that all water has been completely drained from the air filter.
(8) Check to ensure the pressure is normal.
(9) Visually inspect the machine and the hydraulic unit for any oil leaks and take appropriate action if necessary.
(10) Check and clean the cutting fluid pipes and tank, removing all debris.
(11) Check the cutting fluid level and replenish if necessary.
(12) Check all work lights or warning lights to ensure they are functioning properly.
(13) Check and clean any debris on the tool length measuring unit.
(14) Check if the relay is excessively dusty.