What is a Punch Press Machine and how it works?
Sheet metal fabricators use a wide variety of tools and machines to form materials into various shapes and sizes. Precise and repeat cutting is best achieved using specialist equipment and can include shearing, guillotining, laser cutting, plasma cutting etc. A punch press machine is another excellent option to help to manage the cutting of metal and we take an in depth look at how it works.
What is a punch press machine?
A punch press is a large piece of machinery featuring a hydraulic powered ram at the top. These large machines operated by manufacturers have the capabilities of punching holes at high speed. When the ram is engaged, the metal is compressed against a fixed stationary die, creating a hole in the metal. Punch presses are a great way to cut through these harder materials, ensuring safety throughout the process.Components of a punch press machine:
The punch press machine is comprised of various essential components, including:- Base/bed: The lowest part of the frame that offers support to the workpiece holding the dies and other press mechanisms.
- Frame: Provides structural support to the press, housing the ram driving mechanisms and controlling mechanism. It is divided into the upper part (crown) and lower part (bed).
- Flywheel: Acts as the energy storing device, ensuring a constant speed of the ram and preventing fluctuations.
- Brakes: Essential for safety, with two types - standard (quickly brings driveshaft to rest by disconnecting from the flywheel) and emergency (provides stronger braking power with a power shut switch).
- Bolster plate: A thick plate attached to the base of the press to secure the bottom part of the die.
- Pitman: Connects the ram and crankshaft.
- Ram: The primary operating component of the press, moving up and down between guideways with a specific stroke length and strength. It can be adjusted for different requirements, with the punch attached to the bottom of the ram.
- Driving mechanism: Utilizes a crankshaft to power the ram, transferring power from the motor.
- Controlling mechanism: Enables precise operation of the press under controlled conditions, adjusting the length and power of the ram's stroke. A clutch in the driving system disengages power transfer, while microprocessors provide reliable and accurate automation control.
Punch press machines types
Various types of punch press machines are utilized in production, each with its own unique specifications. These include:
Flywheel drive:
While most punch presses nowadays are hydraulically powered for convenience, in the past, a constantly rotating flywheel would supply power to the ram. The flywheel drives the ram using a 'pitman' arm. Historically, flywheels were driven by a leather drive belt that was connected to the line shafting.Mechanical drive:
This is a commonly used type of punch press in the assembly process. There are two variations of mechanical punch presses, distinguished by their clutch or braking system. Older presses employ a full revolution press (open clutch), which necessitates a complete revolution of the crankshaft to halt the process. This can be highly dangerous without strict safety protocols in place. Many countries have stringent health and safety requirements for operating such machines. On the other hand, partial revolution presses can pause the ram at any point during its rotation, providing a higher level of safety.Hydraulic drive:
These presses utilize a hydraulic cylinder to power the ram. The ram moves up and down under the control of valves.Servo drive:
In this press system, the original brake and clutch are combined with the hydraulic ram system. It offers a significantly lower maintenance cost as it does not require hydraulics or an oil-cooling chiller.
The operational principles of a punch press
Numerous industries utilize this efficient equipment to manufacture various products, but how exactly do they function? Punch presses operate similarly to a standard hole punch used on paper, pressing a shape downward into the material to create a clean cut by exerting pressure on the die attached to the press. This process involves two main components: the punch and the die. The punch is connected to the machine's ram, while the die is secured to a bed/anvil with a flat surface perpendicular to the ram's path, resulting in the formation of a hole. Punch presses are typically powered by electric motors with intermittent power requirements. A flywheel is linked to the drive shaft, storing energy when the machine is not in use between cuts and releasing it to the shaft during punching.Advantages of a punch press machine
Punch press machines offer the benefit of delivering extremely accurate cutting. The various components work together to stabilize the workpiece, enabling careful handling of the material.The machines operate reliably, with built-in safety features to ensure the highest level of safety for operators.
Punch press machines are known for their high productivity, precision, and ability to work continuously. By minimizing the need for manual labor, they prove to be efficient in terms of both work output and costs. As technology progresses, fully automated machines help cut down costs while enhancing value and efficiency.
Italian Machinery Association has a wide selection of EUROMAC punching presses. The constant research and technological innovation has allowed Euromac to create a range CNC punching machines that are performing, highly productive and with the lowest running costs.
