What are the methods for maintaining and servicing hydraulic plate bending machines?

I. Daily Maintenance: Must-do Before/After Daily Startup

1. Pre-startup Inspection

• Appearance and Connections: Check if all equipment components are intact and if screws/nuts are loose (especially roller bearing blocks and hydraulic pipeline interfaces). Tighten immediately if loose.

• Hydraulic System: Observe if the oil level in the tank is within the oil gauge scale. Add the same type of hydraulic oil if insufficient; mixing different brands or types is strictly prohibited. Inspect hydraulic pipelines for leaks (e.g., oil stains at joints, hose damage) and replace seals or hoses promptly if leaks are found.

• Lubrication System: Apply lubricating oil/grease (e.g., calcium-based grease) to moving parts such as roller bearings and gear meshing surfaces as required by the equipment manual to ensure sufficient lubrication.

• Electrical System: Check if power cords, control buttons, and indicator lights are functioning normally. Verify that the emergency stop button is sensitive and effective to avoid operational failure due to electrical faults.

2. Operation Monitoring

• Pay attention to abnormal equipment operation sounds. Normal operation produces steady mechanical noise; stop immediately for inspection if abnormal noises or increased vibration occur.

• Monitor the stability of hydraulic system pressure. If it exceeds or fluctuates significantly beyond the rated working pressure range, pump or valve faults may be the cause—stop to troubleshoot.

• Check the roller surface condition. Wipe off metal chips and oil stains with a clean cloth promptly to prevent scratches or contamination on the sheet surface.

3. Post-shutdown Handling

• Clean iron chips, dust, and oil stains from the equipment surface and work area to keep the workbench tidy. Use compressed air to blow debris from gaps if needed.

• Reset the rollers to their initial position, turn off the main power switch, and maintain equipment operation records (e.g., processed sheet specifications, operation duration, abnormal conditions).

II. Regular Maintenance: Periodic In-depth Maintenance (Weekly/Monthly/Quarterly)

1. Weekly Maintenance

• Filtration System: Clean the hydraulic oil filter. Remove the filter element, rinse with kerosene or special cleaning agent to remove impurities, air-dry, and reinstall. Replace the element directly if damaged.

• Guide Rails and Sliders: Inspect guide rail surfaces for scratches and wear, and apply special guide rail lubricating oil. Clean foreign objects on the rails and adjust gaps if sliders move stiffly.

• Seals: Check if the hydraulic cylinder piston rod seals are aged or deformed. Replace with the same type of sealing ring promptly if oil leakage occurs to avoid pressure drop caused by hydraulic oil leakage.

2. Monthly Maintenance

• Hydraulic Oil Quality: Sample and observe the hydraulic oil condition. Normal oil is transparent or pale yellow without impurities, foam, or emulsification. Completely replace the oil and clean the tank if it becomes turbid, black, or odorous. Use silk cloth to wipe the tank inner wall (avoid cotton yarn to prevent fiber residue from clogging oil circuits).

• Roller Precision: Use a dial indicator to measure roller radial runout and axial movement. Adjust bearing gaps or replace bearings if the error exceeds the range specified in the equipment manual (e.g., >0.1mm).

• Electrical Components: Open the electrical control cabinet, clean dust with a brush to avoid short circuits. Check for oxidation on contactor and relay contacts; polish with fine sandpaper or replace if severely oxidized.

3. Quarterly Maintenance

• Hydraulic Pump and Motor: Check the noise and temperature of the hydraulic pump during operation. Normal oil temperature ≤60℃. Disassemble, inspect, and replace worn parts (e.g., bearings, gears) if overheating or excessive noise occurs due to internal pump wear.

• Transmission System: Check the oil level and quality of gearbox lubricating oil; replenish if insufficient or replace if deteriorated. Adjust the tension of chains and sprockets with tensioning devices if loose, and apply special chain grease.

• Safety Devices: Test the sensitivity and reliability of emergency stop buttons, overload protection devices, and limit switches. The equipment should power off immediately after emergency stop, and rollers should stop moving when limit switches are triggered.

III. Special Maintenance: In-depth Maintenance for Key Components

1. Roller Maintenance

• Polish minor scratches on the roller surface with fine sandpaper (≥800 grit). Send for repair or replace if severe collisions or deformation occur to avoid affecting sheet bending precision.

• Apply anti-rust oil to the roller surface and cover with waterproof cloth before long-term shutdown to prevent corrosion.

2. Special Hydraulic System Maintenance

• Replace hydraulic oil every 1-2 years (adjust based on usage frequency; replace annually for full-load daily operation). Replace the filter element simultaneously during oil change.

• Regularly check the flexibility of hydraulic valves (e.g., relief valves, directional valves). Disassemble and clean valve cores with kerosene if stuck; replace valves if necessary.

3. Special Electrical System Maintenance

• Conduct insulation testing on electrical circuits annually with a megohmmeter; insulation resistance should be ≥0.5MΩ. Replace aged circuits promptly.

• Back up the PLC control system program regularly to avoid loss. Clean the touchscreen with a special soft cloth; avoid corrosive liquids such as alcohol.

IV. Fault Prevention and Special Case Handling

1. Load Control: Prohibit bending sheets beyond the equipment's rated specifications (e.g., thickness, hardness) to avoid overload damage to rollers and the hydraulic system.

2. Environment Control: Store the equipment in a dry, well-ventilated workshop to prevent corrosion of electrical components or emulsification of hydraulic oil due to humidity. Avoid storing corrosive materials nearby.

3. Shutdown Maintenance: For long-term shutdown (over 1 month), run the equipment idly for 10-15 minutes weekly to circulate hydraulic oil and prevent oil precipitation. Reapply anti-rust oil to rollers, guide rails, and other parts.

Summary