What are some precautions for maintaining a pipe bending machine?

1. Hydraulic System Maintenance

Oil Management: Regularly check the hydraulic oil level and replenish with the same brand and type of oil if necessary. Change the hydraulic oil after the first 500 hours of operation, and thereafter every 2000-3000 hours or annually. Oil contamination or emulsification is a common cause of hydraulic valve sticking and abnormal cylinder operation.

Oil Temperature Monitoring: The ideal operating temperature for hydraulic oil is 35℃-55℃. Prolonged operation above 60℃ will accelerate oil oxidation and seal aging. Check that the radiator fan is operating normally and regularly clean the oil and dust from the radiator fins.

Filter Replacement: Replace the return oil filter and suction oil filter regularly according to the equipment manual to prevent impurities from entering the hydraulic system and damaging the pumps and valves.

2. Mold and Mandrel Maintenance

Cleaning and Rust Prevention: After each pipe change or shift, clean the bending mold, clamping mold, anti-wrinkle mold, and mandrel surfaces to remove metal shavings and sludge. Apply rust-preventive oil to molds that are not used for extended periods.

Wear Inspection: Regularly inspect the working surface of the mold for indentations, scratches, or localized wear. Excessive wear can cause wrinkling and excessive ovality in bent tubes; timely repair or replacement is necessary.

Mandrel Condition: The joints of the ball-head mandrel must rotate freely. Regularly check the mandrel rod for bending and scratches. Inaccurate mandrel positioning or wear is a major cause of inward collapse and bending in thin-walled tubes.

3. Electrical and Motor Maintenance

Cleaning and Heat Dissipation: Regularly clean dust from the electrical control cabinet and check the cooling fan's operation. Precision components such as frequency converters and servo drives are sensitive to dust; it is recommended to install filters or air conditioning in the electrical control cabinet in harsh environments.

Wiring Inspection: Check the motor terminals and contactor contacts quarterly for looseness, oxidation, or burning marks. Single-phase operation can cause the motor to overheat and burn out rapidly.

Motor Lubrication: For motors with bearing lubrication holes, replenish grease periodically. If abnormal noise or increased vibration occurs, promptly check for bearing wear.

4. Mechanical Transmission and Lubrication

Guide Rails and Lead Screws: Linear guide rails and ball screws of the feed shaft and rotary shaft require regular cleaning and replenishment with special grease. Damaged guide rail protective covers should be replaced immediately to prevent chips from entering and damaging the rolling elements.

Reducer and Gears: Check the reducer oil level and change the gear oil regularly according to equipment requirements. The transmission gears of the bending arm should be kept lubricated; any severe wear or pitting on the gear teeth requires immediate attention.

Fastener Inspection: Long-term equipment vibration may cause anchor bolts and mold fixing bolts to loosen; a quick inspection should be conducted before starting each shift.

5. Cooling and Filtration System

Oil Cooler/Water Cooler: If the equipment is equipped with an independent cooler, the condenser fins need to be cleaned regularly, and the refrigerant pressure and piping leaks checked.

Air Filter: The air filter on the hydraulic oil tank should be kept clean to prevent dust from entering the tank with changes in oil level.

6. Operating Procedures and Daily Inspections

**Preheating:** Especially in low-temperature environments, run the machine unloaded for 5-10 minutes after startup to allow the hydraulic oil to circulate and warm up before putting it into production.

**Daily Inspection:** Establish a daily inspection log, including oil level, abnormal noise, oil leaks, mold wear, and air pressure (if using pneumatic clamping).

**Abnormal Shutdown:** If abnormal noise, vibration, sluggish movement, or sudden changes in bending quality are detected, immediately stop the machine for troubleshooting to prevent the problem from escalating.

7. Periodic Calibration and Accuracy Testing

**Bending Angle Calibration:** Every six months or after changing the mold, use an angle gauge to calibrate the consistency between the equipment's bending angle and the encoder feedback.

**Repeat Positioning Accuracy:** Check the repeatability of the feeding length and rotation angle. If the repeatability exceeds the tolerance, adjust the servo parameters or check the mechanical clearance.

Maintaining a pipe bending machine is not about "repairing it only when it breaks down," but rather a systematic task that runs throughout the day. A four-step cycle of cleaning, lubrication, tightening, and inspection, combined with standardized oil management and mold maintenance, is essential to ensure the equipment always operates with high precision and efficiency.