A hydraulic press brake is a crucial tool in metal fabrication, providing precision and efficiency in bending various materials. Understanding the key components of this essential equipment is vital for maximizing its capabilities and ensuring optimal performance in manufacturing processes.
1. Frame: the foundation
The backbone of a hydraulic press brake is its robust frame, which provides stability and support during the bending process. Typically made of high-strength steel, the frame plays a pivotal role in maintaining accuracy and minimizing deflection. The depth of the frame is equal to the throat depth, providing ample space for bending. Additionally, the frame is equipped with monitoring tools capable of detecting spring back and minimizing its impact.
According to the different frames, hydraulic press brakes can be divided into C-Type Hydraulic Press Brake and G-Type Hydraulic Press Brake.
C-Type Hydraulic Press Brake
The frame of a C-type press brake resembles the letter “C” when viewed from the side. It is a single, open-sided frame. The frame consists of a vertical side and a top horizontal beam. The hydraulic components and bending area are located on the open side of the frame. Following are the Advantages:
- Simplicity: C-type structures are simpler in design, making them easier to manufacture and maintain.
- Accessibility: The open side allows easy access for tooling changes and maintenance tasks.
- Versatility: C-type press brakes are versatile and can handle a wide range of bending applications.
G-Type Hydraulic Press Brake
The frame of a G-type press brake resembles the letter “G” when viewed from the side. It consists of two uprights and a horizontal beam connecting them. The frame is more complex, providing additional rigidity and support. The hydraulic components and bending area are enclosed within the frame structure. Following are the Advantages:
- Rigidity: G-type structures offer increased rigidity, making them suitable for handling heavier workpieces and achieving higher precision.
- Support: The dual uprights provide better support for the entire structure, contributing to enhanced stability during bending operations.
- Precision: G-type press brakes are often chosen for applications where precision is crucial, such as when working with demanding materials or achieving tight tolerances.
2. Hydraulic system
The hydraulic system is employed to regulate the pressure and flow rate of the hydraulic cylinder. It primarily comprises a motor, oil pump, oil filling valve, and oil cylinder, all installed on the frame of the press brake. Each of the left and right vertical plates houses an oil cylinder. The hydraulic pump transforms mechanical energy into hydraulic pressure energy, propelling the hydraulic system. Subsequently, the hydraulic cylinder converts the liquid pressure into kinetic energy to drive the ram.
3. Ram (upper beam)
The ram is also referred to as the upper beam. It is the movable part of the press brake that carries the upper tooling, which typically includes the punch and die. The ram moves vertically, descending to apply force to the workpiece positioned on the bed (lower beam).
During the bending process, the ram and its attached upper tooling come into contact with the workpiece, forming the desired bend. The downward movement of the ram is controlled by the hydraulic system, and the force applied by the ram, in conjunction with the lower tooling on the bed, shapes the material to the specified angle.
4. Bed (lower beam)
The bed, also known as the lower beam, is the stationary horizontal surface of the press brake where the lower tooling is mounted. It provides a stable foundation for the workpiece during the bending process. The bed remains fixed while the upper tooling (usually mounted on the ram) descends to shape the material.
The back gauge is a critical component of the press brake, positioned at the rear of the press brake, controlling and adjusting the position and length of the workpiece during bending, ensuring correct positioning. It can be controlled and adjusted by motors, servo motors, or cylinders. Operators set the position and length through the press brake’s control system to meet different bending requirements.
Controlled by the CNC controller, the back gauge moves on six axes: R-axis for up and down, X-axis for forward and backward, and Z-axis for left and right movements. During bending, the workpiece sits on the die of the workbench, pushed to fit the stop fingers connected to the back gauge.
- Stop Finger: Displays the size of the processed piece and moves on a linear guide rail, allowing smooth adjustment up and down. Multiple stop fingers enable the bending of sheet metal parts of varying lengths.
- Back Gauge Bar: Works with stop fingers, moving and adjusting their position via electric or hydraulic drive. Precise control is achieved through the control system.
- Back Gauge Sensor: Tests the position and length of the workpiece, providing feedback to the control system for a more precise location.
- Back Gauge Controller: An electrical device that controls the back gauge, adjusting workpiece location based on signals from the back gauge sensor.
- Back Gauge Guide Rails: A system installed on the bed to support and guide the movement of the back gauge bar, ensuring steady and precise motion along the bed.
6. Punch and die
The press brake tooling consists of two main components: the punch (top die) and the die. These elements are employed for the stamping, forming, and separation of sheet metal, shaping the workpiece into specific sizes and shapes. The choice of die for bending is influenced by factors such as the bending method, bending angle, raw material, and material thickness. In the bending process, the ram propels the top punch into the bottom die, constituting a bending stroke.
Punches come in various types, including right angle dies, acute angle dies, gooseneck dies, and more. Moreover, the bottom die features U-shaped dies, V-shaped dies, and other configurations to accommodate diverse bending requirements.
7. CNC control unit
Modern hydraulic press brakes come equipped with advanced control systems, often featuring CNC (Computer Numerical Control) technology. This allows for programmable and automated bending operations, enhancing accuracy, repeatability, and overall efficiency in the production process.
8. Safety devices
The press brake is equipped with safety features such as protective covers, emergency stop buttons, and more, all designed to prioritize the safety of operators. Additionally, safety doors are installed on both sides of the press brake. When these doors are closed, the hazardous areas on both sides become inaccessible, enhancing operator safety. In the event of the doors being opened during operation, all axes cease movement as a precautionary measure.
For more advanced protection, the press brake may incorporate cutting-edge safety devices like light curtain safety systems and laser protection devices. These technologies add an extra layer of safety by detecting and responding to potential hazards during machine operation.
9. Hydraulic oil reservoir
The hydraulic press brake features a hydraulic oil reservoir, a crucial component responsible for storing hydraulic fluid. This fluid is utilized to generate the hydraulic pressure needed for the bending operation. The reservoir ensures a consistent and sufficient supply of hydraulic oil, contributing to the smooth and efficient functioning of the hydraulic system in the press brake.
10. Foot pedal or control panel
The control interface of a hydraulic press brake can take the form of a foot pedal or a control panel. The foot pedal allows the operator hands-free control over certain functions, facilitating a more ergonomic operation. Alternatively, a control panel provides a centralized interface for programming and adjusting various parameters, offering precision and customization in the bending process.
In summary, a hydraulic press brake comprises several integral components that work in harmony to deliver precise and efficient metal bending. From the sturdy frame to the advanced control system, each element plays a crucial role in shaping raw materials into finished products. Understanding these components is essential for operators and manufacturers alike, as it empowers them to harness the full potential of this indispensable tool in the world of metal fabrication.