Where do cnc machine tools need compressed air?

CNC machine tools rely on compressed air in many key aspects, mainly used for core functions such as cleaning, cooling, clamping, lubrication and control. The following are specific application scenarios and role analysis:

1. Cooling of spindle and tool

1. role: High-speed rotating spindles and tools generate a lot of heat during the machining process, and compressed air is blown directly into the cutting area through the nozzle to achieve forced cooling.
2. advantages：
   • rapid cooling: Avoid thermal deformation of the spindle due to overheating, which affects processing accuracy.
   • prolong life: Reduce tool wear and reduce the frequency of replacement.
3. case: In aluminum alloy processing, compressed air cooling can increase tool life by more than 30%.

2. Cleaning of workpieces and machine tools

1. role：
   • Cleaning before processing: Blow off impurities such as oil stains and metal chips on the surface of the workpiece to ensure stable clamping and processing quality.
   • Cleaning during processing: Remove chips in real time to prevent scratching the workpiece surface or clogging the tool chip discharge groove.
   • Post-processing cleaning: Clean up residual chips inside the machine tool and keep the equipment clean.
2. advantages：
   • improve accuracy: Reduce impurity interference and reduce scrap rate.
   • protection equipment: Avoid chip accumulation leading to wear of guide rails, screw screws and other components.
3. case: In precision mold processing, compressed air cleaning can reduce the surface roughness to below Ra0.8μm.

3. Pneumatic clamps and chucks

1. role：
   • workpiece clamping: Quickly and stably fix the workpiece by pneumatic chucks or clamps, especially suitable for special-shaped parts or thin-walled parts.
   • automatic tool changing: Pneumatic devices drive tool magazine rotation and tool exchange to achieve efficient automated machining.
2. advantages：
   • Adjustable clamping force: Adjust the air pressure according to the material and shape of the workpiece to avoid deformation caused by excessive clamping.
   • fast response: The pneumatic system acts quickly and shortens the assistance time.
3. case: In the processing of automobile engine blocks, pneumatic clamps can shorten the clamping time to less than 5 seconds.

4. Main shaft air sealing and protection

1. role：
   • Prevent chip intrusion: High-pressure air forms an air curtain at the front end of the spindle to prevent chips and coolant from entering the interior of the spindle.
   • lubrication protection: Some main shafts use air bearing, and compressed air is used as the lubricating medium to reduce friction and wear.
2. advantages：
   • improve reliability: Avoid failure of the spindle due to impurities intrusion and extend service life.
   • reduce maintenance costs: Reduce spindle maintenance frequency and downtime.
3. case: In high-speed machining centers, the air seal system can reduce the spindle failure rate by more than 50%.

5. Pneumatic tool changer (ATC)

1. role：
   • tool exchange: The pneumatic cylinder drives the cutter arm to rotate to realize automatic tool replacement.
   • Tool magazine positioning: Pneumatic control of the precise positioning of the tool magazine ensures the accuracy of tool changing.
2. advantages：
   • Fast tool change speed: The response time of the pneumatic system is short, and the tool change cycle can be shortened to less than 2 seconds.
   • compact structure: The pneumatic device is small and easy to integrate into the machine tool.
3. case: In a five-axis linkage machining center, a pneumatic tool changing device can increase machining efficiency by more than 20%.

6. Lubricating system assistance

1. role：
   • oil-gas mixed lubrication: The compressed air atomizes a trace amount of lubricating oil and sprays it towards the cutting area to achieve dual effects of cooling and lubrication.
   • centralized lubrication: Pneumatic pumps deliver lubricating oil to various lubrication points of the machine tool to ensure smooth operation of guide rails, screw screws and other components.
2. advantages：
   • reduce pollution: Oil and gas mixed lubrication can reduce coolant usage and reduce waste liquid treatment costs.
   • prolong life: Precise lubrication reduces component wear and reduces maintenance frequency.
3. case: In precision machining, oil-gas mixed lubrication can extend tool life to twice the original.

7. Air pressure detection and control

1. role：
   • pressure monitoring: Monitor the air pressure of the spindle air seals, pneumatic clamps and other parts in real time through the air pressure sensor to ensure normal operation of the system.
   • safety protection: When the air pressure is lower than the set value, an alarm or shutdown will be automatically triggered to avoid equipment damage.
2. advantages：
   • improve security: Prevent clamping loosening or spindle failure caused by insufficient air pressure.
   • intelligent management: Linkage with the machine tool control system to achieve automated monitoring and adjustment.
3. case: In high-end machining centers, air pressure detection systems can reduce equipment failure rates by more than 30%.

8. Compressed air quality requirements

1. pressure stability: Usually it needs to be kept at 0.5-0.7MPa, and the fluctuation range does not exceed ±0.05MPa.
2. cleanliness: It needs to be dried and filtered, with oil content ≤0.01mg/m³, and particulate matter size ≤5μm.
3. dryness: The dew point temperature should be lower than-20℃ to avoid moisture causing corrosion of the spindle or pneumatic components.