CNC machine tool compressed air pressure

Technical specifications and configuration guide for compressed air pressure for CNC machine tools

In the field of CNC machining, the compressed air system is the core power source for pneumatic control, and its air pressure parameter settings directly affect the operating accuracy of the equipment and processing quality. It has been verified by industry practice that the compressed air system of CNC machine tools must comply with the following technical specifications:

1. Air pressure parameter standards

1. operating pressure range
   The standard pressure of compressed air for CNC machine tools is 0.5-0.7MPa (5-7bar). This range can meet:
   • Pneumatic tool changing system (pressure accuracy ±0.05MPa)
   • Main shaft air seal device (pressure stability requirement ≤±0.02MPa)
   • Workpiece cleaning air gun (instantaneous flow requirement ≥0.3m³/min)
2. Pressure compensation design
   In order to compensate for pipeline pressure loss, the air compressor system needs to set a pressure margin:
   • Short-distance gas supply (<50m): pressure margin 0.1MPa
   • Long-distance gas supply (>50m): pressure margin 0.15-0.2MPa
   • Typical configuration: 0.5MPa at the air consumption end corresponds to 0.7MPa for the air compressor

2. Air pressure stability guarantee

1. Pipeline design specification
   • Selection of main air supply pipe diameter: Calculate the pipe diameter at 1.3 times of the maximum air consumption
   • Control of the number of elbows: For every 5 additional 90-degree elbows, the pipe diameter needs to be increased by 1 gear
   • Gas tank configuration: The volume should be 15-20% of the total gas consumption of the system
2. Pressure fluctuation control
   • Transient pressure fluctuation: ≤±0.05MPa (affects tool changing accuracy)
   • Continuous pressure fluctuation: ≤±0.02MPa (affects the processed surface quality)
   • Pressure stabilizing measures: Configure precision pressure reducing valve + buffer tank combination device

3. Air quality requirements

1. cleanliness standard
   • Oil content: ≤0.01mg/m³ (dual-stage precision filter is required)
   • Dust content: ≤0.1μm (using HEPA filtration technology)
   • Dew point temperature: -20℃ (freeze dryer can meet basic needs)
2. Purification system configuration
   • Basic configuration: air storage tank + cold dryer + primary filter
   • Precision manufacturing: Add activated carbon filter + adsorption dryer
   • Special requirements: Pharmaceutical grade production requires sterile filtration device (filtration efficiency 99.999%)

4. Monitoring and maintenance specifications

1. real-time monitoring system
   • Pressure sensor: accuracy of ± 0.01MPa, monitoring points cover the main gas supply pipeline and key gas terminals
   • Flowmeter: Use thermal mass flowmeter to monitor changes in gas consumption in real time
   • Dew point meter: Online monitoring of compressed air moisture content and early warning of drying system failure
2. Regular inspection items
   • Pressure attenuation test: Conduct pipeline pressure maintenance test every month (pressure drop ≤ 0.05MPa for 24 hours)
   • Leak detection: Use ultrasonic leak detector to detect quarterly, and the leak rate should be controlled within 5% of the total gas consumption
   • Filter element replacement: precision filters are replaced every 2000 hours, and evaporator of cold dryer is cleaned every year

5. Typical fault handling

1. insufficient air pressure
   • Check whether the air compressor exhaust pressure meets the standard
   • Inspect the tubing for blockages or leaks
   • Verify that the volume of the air storage tank meets the requirements
2. Pressure fluctuates greatly
   • Check the working status of the pressure reducing valve
   • Investigate the source of pipeline vibration (such as loose air compressor foundation)
   • Verify whether there is instantaneous large flow demand for gas equipment

Understanding the technical requirements of CNC machine tool compressed air systems will help companies build highly reliable pneumatic control systems. When selecting equipment and designing system, the machine tool model, processing technology and production rhythm should be combined, and professional calculation and verification should be used to ensure that the compressed air system is always in the best operating state and provide stable and reliable power guarantee for precision machining. For key equipment, it is recommended to configure an intelligent monitoring system to achieve real-time monitoring and early warning of pressure, flow, dew point and other parameters.