Bending machines are essential in metalworking, but they can face hydraulic and electrical issues that hinder their operation. This guide covers common problems such as hydraulic circuit failures, bending machine stalling, and Y-axis setting issues, along with their respective solutions.
Troubleshooting Hydraulic Circuit Failures in Bending Machines
Common Hydraulic Issues
Valve Blockages:
- Directional Control Valve or Relief Valve Sticking: These valves can become stuck, preventing proper hydraulic flow and machine operation.
Electrical Faults Affecting Valves:
- Valve Power Issues: Electrical faults can prevent valves from receiving power, causing malfunction.
Solutions for Hydraulic Problems
Cleaning Stuck Valves:
1. Disassemble the Valve:
- Carefully remove the directional control valve or relief valve.
2. Clean the Components:
- Use appropriate cleaning solutions to remove any debris or buildup from the valve components.
3. Reassemble the Valve:
- After thorough cleaning, reassemble the valve and test its operation.
Checking Electrical Circuits:
1. Inspect Electrical Connections:
- Examine the wiring and connections leading to the valve to identify any loose or damaged wires.
2. Test for Electrical Faults:
- Use a multimeter to check for continuity and voltage at the valve connections.
3. Repair or Replace Faulty Components:
- Fix any identified faults or replace defective components to restore proper valve operation.
Addressing Bending Machine Stalling Issues
Causes of Bending Machine Stalling
Electrical Faults:
- Contactor Malfunction: If the contactor in the electrical box is not working, the machine will stall.
- Foot Pedal Switch Issues: A faulty foot pedal switch can prevent the machine from receiving the necessary signals to operate.
Solenoid Valve Problems:
- Lack of Power to Solenoid Valve: The solenoid valve may not be receiving power, indicated by a lack of magnetic response.
Steps to Resolve Stalling
Checking Electrical Components:
1. Inspect the Contactor:
- Open the electrical box and ensure the contactor is functioning correctly.
2. Test the Foot Pedal Switch:
- Use a multimeter to check if the foot pedal switch is sending the correct signals.
Testing and Cleaning Solenoid Valves:
1. Check Power to Solenoid Valve:
- Observe the indicator light on the solenoid valve or use a piece of iron to test for magnetism.
2. Clean the Solenoid Valve:
- If the valve is receiving power but not functioning, disassemble and clean each solenoid valve individually.
3. Reassemble and Test:
- After cleaning, reassemble the solenoid valve and test the machine's operation.
Resolving Y-Axis Setting Issues in Bending Machines
Problem: Y-Axis Setting Not Moving
When the bending machine is set to a specific Y-axis value, but the blade does not move up or down, it is typically due to electrical malfunctions.
Solutions for Y-Axis Issues
Manual Valve Testing:
1. Check Valve Functionality:
- Manually check each valve to ensure they can open and close properly.
Restarting the Machine:
1. Power Cycle the Machine:
- Turn off the power supply to the machine.
2. Restart the System:
- After a brief wait, restart the machine to reset its operations. This often restores normal functionality.
Additional Tips and Warnings
Caution During Valve Cleaning:
- Sequential Cleaning: Clean and test each solenoid valve individually to avoid mixing up components and causing further issues.
Seek Professional Help When Needed:
- Professional Maintenance: If the above methods do not resolve the problem, contact a professional technician for repair and adjustment.
Practical Guide to Ensuring Optimal Bending Machine Performance
1. Ensuring Proper Power Supply
Initial Steps:
- Connect Power: Ensure the bending machine is connected to a stable power supply.
- Activate Control Panel: Turn on the key switch and start the oil pump to power up the machine.
2. Stroke Adjustment
Set Stroke Parameters:
- Adjust Top Dead Center: Ensure the upper die's lowest position leaves a gap equal to the sheet thickness.
- Use of Rapid and Fine Adjustments: Adjust the stroke using either rapid electric adjustments or manual fine-tuning.
3. Selecting Appropriate Die Slot
Slot Width Selection:
- Slot Width Guidelines: Select a slot width that is eight times the thickness of the sheet metal (e.g., for 4mm thickness, use a 32mm slot).
4. Adjusting the Back Gauge
Gauge Positioning:
- Electric and Manual Adjustments: Adjust the back gauge using electric rapid adjustment or manual fine-tuning, similar to the shearing machine method.
5. Operating the Bending Process
Starting Bending:
- Foot Pedal Use: Press the foot pedal to initiate bending. Release to pause and press again to continue.
Maintaining Hydraulic Pressure Balance
Hydraulic System Pressure Management
Pre-Operation Check:
- Activate Hydraulic System: Turn on the machine, activate the oil pump, and ensure the hydraulic system is operational before applying pressure.
- Pressure Adjustment: Adjust the hydraulic pressure to meet the required levels, usually between 10-15 MPa, to avoid excessive wear or poor adhesion.
Avoid Over-Pressure:
- Balanced Pressure Application: Ensure that the pressure applied is balanced to prevent mechanical wear and material damage, such as wrinkling or curling.
Safety Precautions
Distance from Moving Parts:
- Keep Hands Away: Maintain a safe distance from the rollers and other moving parts to prevent injury.
Proper Edge Handling:
- Edge Cutting: Use appropriate tools to cut the edges of the material to the correct width and wrap the cut strips on the winding roller.
Conclusion
Maintaining and troubleshooting a CNC bending machine involves understanding its hydraulic and electrical systems. By following the detailed steps for addressing common issues, adjusting bending parameters, and ensuring safety protocols, operators can ensure efficient and safe machine operation. Always refer to the specific machine’s user manual for detailed instructions and consult the manufacturer or a professional technician for additional guidance.
