What Is an Air Press?
An air press is a sheet metal processing machine powered by air pressure.
They are classified as mechanical presses, and are also called “pneumatic presses.” Air presses effectively process metal by using air pressure to raise and lower dies. The feature of air presses is their high processing speed. They are suitable for mass production and processes that require high productivity.
Uses of Air Presses
Air presses are mainly used for bending, punching, cutting, and riveting. They are also used in the following processes: drawing, deep drawing, forging, and coining.
1. Drawing
This is the process of making a seamless cylinder, rectangular tube, cone, or other container from a single sheet of metal.
2. Forging
Press machines are also partially used in the forging process. Other processes include the use of material feeders and lubrication equipment.
3. Coining
This is a processing method used when bending angle accuracy is required.
4. Deep Drawing
Deep drawing is considered being a difficult process because wrinkles and distortion easily occur. Specifically, it is suitable for numbering parts for the automotive industry and traceability, and for stamping electric, electronic, and automotive parts that require mass production.
Principle of Air Presses
A typical air press is a crank-type press. Among crank-type presses, the air clutch type, which is powered by compressed air, is the most common type. Other types include knuckle mechanisms and link mechanisms.
1. Air Clutch Type
When the flywheel is rotated by the motor and the clutch is engaged by a pushbutton or the like, power is transmitted to the crank. This force is transmitted to the connecting rod, causing the slide to move up and down.
Static accuracy, pressure, torque, and work capacity are important characteristics. Static accuracy refers to the press accuracy in terms of straightness, parallelism, and squareness between the slide and the bolster (base for receiving press pressure).
2. Crank Mechanism
The crank mechanism moves the slide up and down by means of a crank-shaped rotating shaft. It is commonly used for bending, drawing, and forging.
3. Knuckle Joint Mechanism
This mechanism is suitable for cold forging presses due to its slow speed near the bottom dead center (lowest point of stroke).
4. Link Mechanism
Compared to the crank mechanism, the speed during machining is lower and the slide rises faster. This mechanism reduces impact, noise, and vibration during processing and improves formability in deep drawing.
5. Servo Press
Servo presses are a type of mechanical presses. It is driven by a servomotor without a flywheel.
With a servomotor, the direction of rotation can be switched, and the stroke width can be changed by repeatedly rotating and counter-rotating the slide width of the press.