1. Overview of Hydraulic Flying Shear

A Hydraulic Flying Shear is a high-performance cutting device widely used in continuous Rolling Mills, steel plate processing, pipe production lines, and bar manufacturing. Its main function is to cut moving metal materials into specified lengths without stopping the production line, thereby ensuring continuous and efficient operation.

Unlike traditional mechanical shears, the hydraulic flying shear utilizes hydraulic cylinders and servo control systems to drive the cutting blades, providing high cutting force, flexible operation, and stable performance. This makes it especially suitable for cutting thick plates, large-section steel, and high-strength materials in heavy-duty industrial environments.

Hydraulic Flying Shears are typically installed in hot rolling, cold rolling, and continuous casting production lines, serving as the key equipment for length control and online shearing.

2. Working Principle of Hydraulic Flying Shear

The working principle of the hydraulic flying shear is based on synchronized motion and hydraulic power transmission.

During operation, the continuous material passes through the shear zone at a constant speed. When the measuring system detects that the preset length has been reached, the control system sends a signal to the hydraulic system. The hydraulic cylinders then accelerate the cutting frame (also called the flying carriage) to match the line speed of the moving material.

Once synchronized, the upper and lower blades close rapidly under hydraulic pressure, completing the shearing process. After cutting, the cylinder reverses, and the shear carriage returns to its initial position, preparing for the next cut.

Modern hydraulic flying shears often integrate PLC or CNC systems to ensure precise timing, synchronization, and cutting length control. Advanced models are also equipped with proportional hydraulic valves, servo-hydraulic systems, and real-time feedback sensors, which improve response speed and accuracy.

3. Structure and Main Components

A hydraulic flying shear typically consists of the following major components:

1. Main Frame: The rigid steel structure that supports the entire machine and ensures stability during operation.

2. Hydraulic System: Includes pumps, valves, hydraulic cylinders, oil tanks, and pipelines. Provides cutting power and motion control.

3. Shear Carriage: The moving assembly that carries the blades and performs the synchronized motion.

4. Cutting Blades: Made of high-strength alloy steel with heat treatment for durability and sharpness.

5. Measuring Device: Uses encoders or laser sensors to monitor material length and speed.

6. Control System: Usually a PLC or CNC system for automatic synchronization and precision control.

7. Guiding and Transmission System: Ensures smooth linear motion and stable acceleration.

8. Cooling and Lubrication System: Maintains optimal operating temperature and minimizes wear.

9. Safety Protection System: Includes protective covers, pressure sensors, and emergency stops.

4. Classification of Hydraulic Flying Shears

Hydraulic flying shears can be classified as follows:

1. By Structure:

• Horizontal Type: The most common structure, suitable for bars and plates.

• Vertical Type: Used for cutting billets and slabs.

2. By Function:

• Hot Hydraulic Flying Shear: Designed for hot rolling lines, can withstand high temperatures.

• Cold Hydraulic Flying Shear: Used for cutting cold materials such as coils or finished bars.

3. By Cutting Mode:

• Single-Blade Shear: For medium-speed cutting.

• Double-Blade Shear: For high-speed and heavy-duty cutting.

4. By Application:

• Bar Shear, Plate Shear, Tube Shear, and Billet Shear, depending on material type.

5. Performance Characteristics and Advantages

• Strong Cutting Force: Hydraulic drive provides high pressure and stable force output.

• Continuous Operation: Enables uninterrupted cutting during continuous production.

• High Precision: Servo control ensures synchronization and length accuracy.

• Wide Applicability: Suitable for various materials and thicknesses.

• Smooth Operation: Hydraulic cushioning reduces vibration and noise.

• Flexible Adjustment: Cutting parameters can be modified easily via touch screen.

• Energy Efficiency: Modern hydraulic systems use variable displacement pumps for reduced power loss.

• Safety and Reliability: Equipped with overload protection and automatic fault alarm.

6. Application Fields

Hydraulic flying shears are extensively used in:

1. Steel Rolling Mills: For cutting billets, bars, and rods in hot rolling lines.

2. Pipe Mills: For cutting pipes during continuous production.

3. Plate and Coil Processing: Used for trimming or fixed-length cutting in cold rolling lines.

4. Construction Steel Production: For rebar and H-beam length cutting.

5. Shipbuilding and Heavy Machinery Industries: For thick plate cutting operations.

7. Maintenance and Operation Tips

To ensure stable performance, follow these guidelines:

• Regularly inspect hydraulic oil quality and maintain clean filters.

• Check for oil leaks and abnormal noises in hydraulic cylinders.

• Calibrate sensors and encoders periodically.

• Replace worn blades promptly.

• Monitor temperature and pressure indicators during operation.

• Perform preventive maintenance every 3–6 months.

Conclusion

The Hydraulic Flying Shear represents a critical advancement in modern metal processing technology. With its powerful cutting capacity, precise control, and adaptability to various production environments, it has become an essential component of continuous production lines. As automation, energy efficiency, and intelligent control technologies evolve, hydraulic flying shears will continue to improve in performance, reliability, and intelligence, driving the modernization of global steel and metal industries.