Basic compressed-air requirements for machining equipment
In modern machining workshops, compressed air is one of the essential power sources. Key processes such as pneumatic fixtures, tool‑change mechanisms, spindle sealing, and chip removal all rely on stable air pressure. Different machines have specific pressure requirements, and maintaining compliance with these specifications is crucial for ensuring machining accuracy and extending equipment life.
Air Pressure Ranges of Common Machining Equipment
- CNC machining center: Typically, the gas supply pressure is required to be within 0.5 MPa To 0.7 MPa within this range. This pressure range ensures smooth tool changes in the tool magazine and provides adequate back pressure for the spindle’s air-seal system, preventing coolant and chips from entering the spindle bearings.
- CNC lathe: The clamping actions of the pneumatic chuck and tailstock typically require 0.4 MPa To 0.6 MPa of compressed air. Too low a pressure will result in insufficient workpiece clamping force, posing a safety hazard during machining.
- Special-purpose machine tools: For wire EDM and electrical discharge machines, the pneumatic systems are relatively simple, primarily used for stirring the dielectric fluid or operating pneumatic fixtures, typically 0.4 MPa To 0.5 MPa This will suffice to meet the requirements.
The impact of abnormal air pressure on machining
Fluctuations in air pressure directly affect the operating condition of machine tools, primarily manifesting in the following two ways:
- Pressure is too lowThis can result in sluggish actuation or incomplete positioning of pneumatic components; for example, the tool‑change manipulator may jam, and workholding fixtures may loosen. Furthermore, a degraded chip‑blowing function can cause chips to wrap around the cutting tool, severely degrading workpiece surface quality and potentially triggering a low‑pressure alarm that shuts down the machine.
- Pressure is too highProlonged operation under excessive pressure accelerates the wear of pneumatic components such as cylinders and solenoid valves, significantly increasing the risk of seal failure and pipeline leaks, while also unnecessarily raising the air compressor’s energy consumption.
Recommendations for Air Compressor Selection and Pressure Setting
To meet the pneumatic pressure requirements of machining equipment, the air compressor configuration and pipeline network design must adhere to scientific principles.
- Set the exhaust pressure appropriately.The air compressor’s rated discharge pressure should exceed the pressure requirement of the workshop’s highest-demand pneumatic equipment by 0.1 MPa To 0.2 MPa, to compensate for the frictional pressure losses incurred during transmission through the pipeline network.
- Equipped with gas storage and purification equipmentMachining places certain cleanliness requirements on compressed air. It is recommended to install an air receiver tank downstream of the air compressor to dampen pressure fluctuations, and to equip the system with an air dryer and a precision filter to remove moisture and contaminants from the air, thereby preventing corrosion and seizing of pneumatic components.
- Zonal air supply strategyIf both high-pressure and conventional-pressure demands are present in the workshop, it is recommended to adopt a staged‑pressure supply system or a localized pressure‑boosting solution to prevent excessive overall network pressure and associated energy waste.