CNC metal plate press brake bending machines come in various types, each employing different driving methods. These methods impact accuracy, efficiency, and operational requirements.
Servo Motor-Driven CNC Bending Machines
A full servo motor CNC bending machine uses an AC servo driver to control a permanent magnet synchronous brushless motor. There are three primary driving methods for these machines:
Electrohydraulic Valve Control Drive
In this method, hydraulic pumps and valves provide the driving force. The hydraulic pump maintains pressure, while the hydraulic valve controls the flow rate and direction of the hydraulic oil. The control system manages machining accuracy by regulating the valve’s opening and closing times. However, this method often results in lower machining accuracy and is best suited for applications with less stringent accuracy requirements. Temperature changes in the hydraulic oil can significantly impact machining accuracy, making the operator’s understanding of the system’s characteristics crucial for maintaining stable accuracy.
Oil-Electric Hybrid Pump Control
This approach uses a servo motor to drive a plunger pump, which provides precise pressure control. The flow rate and direction of the hydraulic oil are managed by the servo motor’s rotation speed and direction. This results in improved pressure accuracy, faster oil cylinder movement, and enhanced machining efficiency. The reduced reliance on hydraulic oil also minimizes temperature fluctuations, which helps maintain high precision over time and eases the operator’s burden.
All-Electric Servo Drive
Machines driven entirely by servo motors avoid using hydraulic oil for pressure transmission, thus eliminating related accuracy and speed issues. This method ensures consistent bending accuracy, better adaptability to varying environmental temperatures, and high performance even under prolonged heavy loads. Overall, the all-electric servo drive offers superior machining accuracy, speed, stability, and operator convenience compared to other methods.
Key Characteristics of Electro-Hydraulic Servo CNC Metal Plate Press Brake Bending Machines
Despite their higher cost, electro-hydraulic servo CNC metal plate press brake bending machines offer several significant advantages:
- High Precision: The integration of electric motors with servo motor cabinets and computer control systems allows for precise bending angle control, meeting the needs of complex parts.
- High Efficiency: The responsive hydraulic system enhances operational efficiency, reducing bending time and increasing productivity, making it ideal for large-scale operations.
- Wide Process Scope: Capable of processing various materials, including metals like steel, aluminum, and copper, as well as non-metals like plastics and wood. The machine can handle different thicknesses of parts.
- Convenient Operation: Features a user-friendly interface, simplifying machine operation and data management, thus improving operational efficiency and accuracy.
- High Security: Equipped with safety devices such as safety gratings and doors to ensure operator safety and reduce hazards.
Operating Precautions for Electro-Hydraulic CNC Metal Plate Press Brake Bending Machines
To ensure high precision and extend the machine’s service life, operators should follow these precautions:
- Focus during operation, coordinate hand and foot movements, and wear personal protective equipment. Avoid operating the machine while fatigued, distracted, or under the influence of alcohol or drugs.
- Do not place hands or fingers between the upper and lower molds. Ensure safety measures, such as raising the travel switch when loading, and keeping feet away from the foot switch.
- Allow the machine to idle for 1 to 3 minutes before starting to check that all buttons and safety devices are functioning properly, and ensure that there are no malfunctions or unusual noises.
- If the machine is idle for an extended period, loosen the wire wheel to prevent deformation from prolonged compression, which can affect accuracy.
- Always exit the CNC system program before shutting down and disconnect the power.
- Avoid bending materials that exceed the machine’s performance specifications to prevent damage.
Difference Between Torsion Axis Synchronous and Electro-Hydraulic Synchronous Bending Machines
The torsion axis synchronous bending machine and the electro-hydraulic synchronous bending machine differ in several key areas:
- Bending Speed: The torsion axis synchronous machine has a slower bending speed, suitable for general needs. The electro-hydraulic machine is faster, accommodating complex workpieces more efficiently.
- Bending Effect: The electro-hydraulic machine provides better bending accuracy due to its ability to automatically adjust the position of the oil cylinders using optical rulers. The torsion axis machine relies on a synchronous belt and motor, which does not offer automatic adjustments.
- Control Axes: The torsion axis machine typically controls up to 2+1 axes, while the electro-hydraulic machine can manage at least 3+1 axes and can be configured with more complex setups like 4+1+2 or 5+1+2 axes.
