What is an Electro-Hydraulic Bending Machine?

An electro-hydraulic press brake is a CNC machine tool that uses electricity to drive a hydraulic system to precisely bend sheet metal. It is the most mainstream and efficient bending equipment in the modern metalworking industry.

1. Core Components
A standard electro-hydraulic press brake consists of the following main components:

Frame: Typically a sturdy welded steel structure, ensuring stability and precision under immense pressure without deformation.
Hydraulic System: The power source.
Oil Pump: Provides high-pressure oil to the entire system.
Cylinder: Typically, there are two synchronized cylinders that move the slide (upper die) up and down.
Hydraulic Valves: Control the direction, pressure, and flow of the oil, thereby precisely controlling the slide's speed and pressure.
Oil Tank: Stores the hydraulic oil.
CNC (CNC) System: The control core. The operator enters sheet material parameters (material, thickness, length), bend angle, and bending steps. The CNC system automatically calculates and controls the stroke, pressure, and speed of the hydraulic cylinder to ensure bending accuracy.
Ram: The part that mounts the upper die and is driven downward by the hydraulic cylinder to complete the bend.
Bed: The part that mounts the lower die, typically full length, with a T-slot for securing the die.
Back Gauge: A precision positioning device driven by a servo motor that determines the placement of the sheet metal and thus controls the position of the bend line. This is a critical component for ensuring dimensional accuracy.
Tooling: This includes the upper punch and lower die. Different tool shapes allow for different bending angles and shapes.

2. Working Principle (Workflow)
Programming: The operator enters the processing requirements on the CNC screen (e.g., bend a sheet metal part at a 90° angle with two sides 100mm long).
Positioning: The servo motor drives the back gauge to the specified position, and the operator places the sheet metal against the back gauge.
Starting: Depressing the foot switch or pressing a button starts the machine. Downstroke: The CNC controls the hydraulic system, driving the slide downward rapidly. When approaching the workpiece, it switches to feed (slow) mode to ensure smooth contact.
Bending: The slide continues downward, pressing the sheet into the V-shaped opening of the lower die, causing plastic deformation and reaching the preset angle.
Dwelling: After reaching the target position or detecting sufficient pressure, the slide briefly holds its position to fully form the material, release internal stresses, and reduce springback.
Return: Once the bend is complete, the slide quickly returns to its initial position, completing the cycle.
Key Features and Benefits
High Precision and Consistency: The CNC system ensures highly consistent angles and dimensions for every bend, making it ideal for high-volume production.
High Flexibility: Programmable bends of varying angles and dimensions can be quickly completed, allowing new workpieces to be processed after a die change.
Powerful Processing Capabilities: Capable of bending very thick and long sheet metal (e.g., pressures exceeding 100 tons and worktable lengths ranging from several meters to over ten meters). High Safety: Typically equipped with light barriers, laser safety devices, and other safety features, the machine will stop immediately if foreign objects or human hands enter the danger zone.
High Production Efficiency: A high degree of automation reduces operator workload and the need for operator proficiency.

3. Differences from Traditional Mechanical Bending Machines