When purchasing a press, you have several options, including manual, pneumatic, hydraulic, and hydropneumatic presses. Among these, pneumatic press brakes are frequently used by manufacturing companies as robust industrial machines for deforming workpieces.
What is a Pneumatic Press Brake
A pneumatic press brake utilizes a pneumatic system to apply force to a workpiece. Compressed air powers the press, driving a piston or a series of pistons that apply force to the workpiece. Manufacturing processes commonly use pneumatic presses to form, shape, and join materials. These presses are preferred because they generate a force greater than what the workforce can achieve alone. Industries use them for various industrial actions, such as pressing, squeezing, forming, and more.
Types of Pneumatic Press Brake
Energy can be removed by a brake in several ways. Here are some different approaches to braking:
- Band—Band brakes are the simplest type of brake. They have a metal band lined with heat- and wear-resistant friction material.
- Drum—Drum brakes press shoes against a spinning surface. They are often used on automobile rear wheels.
- Disc—Disc brakes have brake pads, a caliper, and a rotor. During operation, the brake pads are squeezed against the rotor. Disc brakes have good heat dissipation properties.
- Cone—Cone brakes consist of a cup and a cone, which is lined with a heat- and wear-resistant friction material. During actuation, the cone is pressed against the mating cup surface. Cone brakes are not commonly used.
Several engagement methods are available for pneumatic brakes, including:
- Noncontact—Braking action is achieved through a non-contact technology such as a magnetic field, eddy currents, etc.
- Friction—Friction between contact surfaces transmits power. This is the most common type of brake.
- Toothed—Toothed contact surfaces transmit power without slipping or heat generation. Teeth are engaged only when stopped or running at a slow speed (< 20 rpm).
- Wrap Spring—A coiled spring wraps downward onto the rotating element. The brake is disengaged when the spring is uncoiled via a control tang at its end.
- Oil Shear—Braking action is engaged via the viscous action of the shearing of transmission fluid.
Features
There are two brake operation methods for pneumatic brakes: spring actuation (engage) and spring return (disengage):
• Spring Actuation/Engage—The spring engages during operation and requires power to disengage. Spring-actuated brakes are also called power-off brakes, fail-safe brakes, and safety brakes.
• Spring Return/Disengage—The brakes need power to engage. A spring is used to disengage the brake. Spring-return brakes are also called power-on brakes and non-fail-safe brakes.
Though pneumatic brakes are most familiar to us as they are used in trucks and trains, they are handy to use in factory environments where compressed air is readily available. Brakes that are integrated into machine tools, conveyors, and other equipment can safely slow their operating components without taking on any additional weight that may be associated with a hydraulic system. Air brake equipment is much more reliable than hydraulic brakes. An additional advantage of pneumatic brakes is that the working fluid supply is unlimited and will never run out. Small leaks will not lead to brake failure.
Advantages of Pneumatic Press Brake
- It does not generate heat
- Quick to react
- Minimal energy use
- Useful in all industries.
- A pneumatic press relies on a comparatively straightforward operation compared to other presses.
- Pneumatic presses are typically substantially less expensive to buy as a result.
- Cost-effective for methods involving mass production
- It can support a variety of workpieces.
- Using a pneumatic press provides control over the size and dimensions of the workpiece.
- It produces very little noise when operating
Comparison of pneumatic and hydraulic press brakes
Certain shaping presses have hydraulic systems for manipulating workpieces, called hydraulic presses. They can accomplish many of the same production tasks as their pneumatic counterparts. However, the two types of presses differ in how they are powered. Hydraulic presses are powered by pressurized liquid, with a descending piston pushing a top plate into the workpiece as it presses into the liquid-filled tank. The piston generates pressure in the liquid, which cannot expand, pushing the top plate into the workpiece.
On the other hand, pneumatic presses are powered by compressed gas or air and use compressive forces to manipulate workpieces, just like hydraulic presses. However, pneumatic presses employ pressurized gas or air, while hydraulic presses use pressurized liquid. Compared to hydraulic presses, pneumatic presses are faster and simpler.
How Pneumatic Press Brakes Work
Basic Operating Principles
- Function: Pneumatic press brakes use compressed air to create the force necessary for bending and forming metal workpieces. This force is applied through a ram or pressing tool that shapes the material as it is pressed against a die.
- Pressure Application: Compressed air is directed into pneumatic cylinders, which then convert the air pressure into mechanical force. This force drives the ram to perform the bending operation.
- Cycle Operation: The press brake operates in a cycle where the ram moves downward to apply pressure, bends the workpiece, and then returns to its original position. The cycle can be manually controlled or automated depending on the machine type.
Role of Pneumatic Cylinders and Compressors
- Pneumatic Cylinders:
- Function: Pneumatic cylinders are critical components that translate the compressed air pressure into linear mechanical motion. They push the ram downward to apply bending force on the workpiece.
- Types: Different types of pneumatic cylinders, such as double-acting cylinders, can be used depending on the required force and movement precision.
- Adjustment: Cylinder stroke length and pressure can be adjusted to control the depth and force of the bend.
- Compressors:
- Function: Compressors generate and supply the compressed air needed to operate the pneumatic cylinders. They ensure a steady and reliable air pressure for consistent performance.
- Types: Various types of compressors, including rotary screw and piston compressors, can be used based on the required air volume and pressure.
- Maintenance: Proper maintenance of compressors is essential to ensure a continuous supply of clean and dry compressed air, which is crucial for optimal press brake operation.
Control Mechanisms and Adjustments
- Control Panels:
- Function: Control panels allow operators to set and adjust parameters such as pressure, stroke length, and bending speed. They often include gauges, switches, and digital displays.
- Types: Panels can range from simple manual controls to sophisticated digital or programmable interfaces that offer precise control and automation.
- Adjustments:
- Pressure Regulation: The pressure applied by the pneumatic cylinders can be adjusted using pressure regulators to achieve the desired bending force.
- Stroke Length: The length of the ram's movement can be adjusted to control the depth of the bend. This is typically done through mechanical stops or digital controls.
- Speed Control: The speed at which the ram moves can be adjusted to accommodate different materials and bending requirements. This can be managed through flow control valves or programmable settings in automated systems.
Pneumatic vs. Hydraulic Press Brakes
Pneumatic press brakes are advantageous due to their faster cycle times, simpler design, and cost-effectiveness, along with their compact size and flexibility for various applications. However, they have limited force capacity compared to hydraulic systems and are less suited for high-torque or heavy-duty tasks. In contrast, hydraulic press brakes offer higher force capacities and precision, making them ideal for heavy-duty bending tasks and a wide range of materials and thicknesses. Nevertheless, they come with a higher initial cost, increased maintenance requirements, and a larger footprint, which can lead to potentially higher energy consumption.
Pneumatic vs. Electric Press Brakes
Pneumatic press brakes offer advantages such as lower installation and maintenance costs, efficiency for rapid operations, and cleaner operation with fewer moving parts. However, they generally have limited precision and control compared to electric systems and may be less energy-efficient, often requiring a continuous supply of compressed air. On the other hand, electric press brakes provide high precision and control with programmable settings, are more energy-efficient and environmentally friendly, and ensure greater consistency in bending accuracy and repeatability. Nonetheless, they come with a higher initial cost, increased complexity, and require specific electrical infrastructure, which can result in higher maintenance costs.
What Is Pneumatic Press Brake Used For?
A pneumatic press brake is used for bending and shaping metal workpieces by applying controlled force through compressed air. Common applications include:
- Sheet Metal Bending: For creating various angles and shapes in metal sheets.
- Fabrication: In industries like automotive, aerospace, and manufacturing for producing components and parts.
- Custom Parts Production: Ideal for small to medium-sized custom projects requiring precise bends and forms.
- Prototype Development: Useful in developing prototypes where flexibility and rapid adjustments are needed.
Pneumatic press brakes are valued for their efficiency in tasks that demand quick cycle times and are well-suited for operations with lower force requirements and simpler bending needs.
Pnuematic Press Brake Manufactures
Several manufacturers are well-known for producing pneumatic press brakes. Some notable ones include:
- Durma - Known for a range of pneumatic press brakes with robust build quality and advanced features.
- Amada - Offers pneumatic press brakes designed for versatility and precision in metalworking.
- Haco - Provides a variety of pneumatic press brakes with options for different production needs.
- Baileigh Industrial - Known for high-quality pneumatic press brakes suitable for various applications.
- Wilson Tool - Offers pneumatic press brakes that focus on durability and ease of use.
These manufacturers offer a range of models catering to different needs, from basic to advanced pneumatic press brakes.
Conclusion
In conclusion, pneumatic press brakes are a valuable tool for metalworking operations that require efficient and precise bending with a focus on cost-effectiveness and ease of maintenance. Their advantages include faster cycle times, a simpler design, and a compact footprint, making them ideal for smaller workshops and less demanding applications. However, they come with limitations such as lower force capacity and less precision compared to hydraulic and electric press brakes. Despite these constraints, pneumatic press brakes remain a practical choice for a variety of manufacturing tasks, offering reliable performance and versatility for a range of bending and forming needs.
pneumatic press brakes are a valuable tool for metalworking !!