There are many types of bending machines, such as mechanical press brakes, hydraulic press brakes, servo-electro press brakes, and more.
Currently, the most widely used is the CNC press brake, which is an electro-hydraulic servo press brake.
The servo system and grating ruler of the electro-hydraulic servo press brake can control the accuracy of the machine during operation.
The CNC control system can set all bending parameters to ensure the accuracy of bending procedures.
This article will introduce the structure, operation and maintenance of the CNC press brake.
The main body of the press brake is composed of two C-shaped frames on the left and right sides.
The bottom worktable and the top beam are connected to the C-shaped frames.
The ram part consists of a crossbeam with upper punches and a workbench with bottom dies.
The back gauge aims to provide an accurate positioning function.
The components and operation of the press brake are basically the same, with differences in driving sources and individual parts.
Next, this article will detail each component of the press brake.
Frame
The frame of the press brake is the basic structure that supports other parts.
It's usually a high-strength, all-welded C-shaped structure, composed of left and right side vertical plates, a bed (worktable), and connecting supports.
However, there are also square-shaped frames.
The depth of the frame, which is the throat depth, provides enough bending space.
There are also monitoring tools on the frame to detect springback and keep it to a minimum.
Ram
The ram of the press brake can be divided into upper and lower parts.
It's the component of the driving mechanism that applies pressure to the machine.
The ram is made of a whole steel plate, and the piston rod connects the ram with the oil cylinders.
The ram is driven by synchronous hydraulic cylinders on both sides.
In a mechanical press brake, the ram is driven by a crank mechanism and flywheel.
The grating rulers on both sides of the ram can accurately position it for synchronous movement.
With the help of the oil cylinder and mechanical stopper, the ram can prevent crowning.
Workbench
The workbench is the foundation of the press brake. The tool holder for the bottom dies is installed on the workbench.
There are two motion modes when bending. One is the downward movement of the top die, and the other is the upward movement of the lower die.
The beam drives the ram to exert a force downward, which is evenly distributed.
The crowning mechanism of the press brake workbench can adjust the force distribution accordingly.
Back Gauge
The back gauge is a set of devices located at the rear of the press brake.
It is used to precisely position the workpiece before bending.
The back gauge of the CNC press brake is driven by different motors and moves on different axes.
The ball screw and timing belt ensures the synchronous movement of the back gauge.
The back gauge is controlled by the CNC controller and can move on 6 different axes.
The R-axis indicates upward and downward movement. The X-axis represents forward and backward movement. The Z-axis indicates left and right movement.
When the back gauge moves forward and backward, the force is limited to 150N to prevent collision.
During bending, the workpiece is placed on the die of the workbench. Push the workpiece to fit with the stop finger. The back gauge has many stop fingers connected with the workpiece.
Tool Clamps
Press brake clamps are used to fix the tooling. Clamps are divided into upper clamps and clamps on the workbench.
During the clamping process, the upper clamps can automatically align the center.
Clamps are also divided into ordinary clamps and fast tool clamps.
Fast tool clamps can quickly and conveniently replace the punches.
Punches and Dies
The tooling of the press brake is divided into the punch (top die) and the die.
The die used for bending depends on the bending method, bending angle, raw material, and material thickness.
During bending, the ram drives the upper die to press into the lower die, which is a bending stroke.
Punches have right angle dies, acute angle dies, gooseneck dies, etc., and the lower die has U-shaped dies, V-shaped dies, etc.
Hydraulic System
The motor, oil pump, oil filling valve, and oil cylinder are the main components of the hydraulic system.
These devices are mounted on the press brake's frame, and there is an oil cylinder on each of the left and right vertical plates.
The hydraulic pump converts mechanical energy into hydraulic pressure energy to drive the hydraulic system.
The hydraulic cylinder converts the liquid pressure into kinetic energy to drive the ram.
Various control valves in the hydraulic system accurately regulate the oil output, pressure, and other parameters to control the hydraulic system's movement.
Control System
The controller of the CNC press brake can control the bending process through programming.
The controller can accurately control the movement of different parts of the machine.
The controller can save complex bending steps for reuse.
There are two versions of the controller: button and touch screen.
The control system provides 2D and 3D graphics programming to simulate the bending process.
Various parameters can be saved in the system.
Currently, the most popular controller brands in the market include Delem, ESA, Cyblec, and others.
Safety Devices
Press brakes usually have safety doors on both sides.
When the safety doors are closed, the dangerous area on both sides is inaccessible.
When the safety doors are opened during operation, all axes will stop moving.
More advanced protection devices include light curtain safety devices and laser protection devices.
Conclusion
If you are new to press brakes, you can read this article to understand the basic knowledge of press brakes.
ADH's press brakes include CNC press brake, NC press brake, large press brake and robot bending cell.
The bending tonnage ranges from 30 tons to 3000 tons. The controller brands include ESTUN, DELEM, CYBELEC and ESA.
You can browse our products to choose the right machine or consult our sales to learn about detailed information.
