We continue with the hot forging machinery, through the family of presses.
We can divide the presses into three groups: hydraulic, eccentric and knuckle joint.
The hydraulic presses, using Pascal’s law, operate the hammer, between the guide columns arranged in a V shape, by means of a hydraulic cylinder, powered by a hydraulic motor.
Compared to power hammers, hydraulic presses, but also other types:
– have greater precision, as they are less influenced by external factors, such as vibrations;
– are slower, but for this reason the springback in the components is minimal;
– are unable to raise the temperature of the part and, for this reason, they are less suitable for obtaining low thickness components.
The eccentric presses operate the hammer by means of an eccentric shaft with two supports or slider-crank, powered by an electric motor.
The eccentric presses can be muzzle, direct transmission, or delayed, where the power is amplified by the use of reducers.
Compared to hydraulic presses, they are more “robust” and require less maintenance.
There is a particular “front” eccentric press, called swan neck, which, due to its C-shaped structure, allows working on the three free sides (useful for example in sheet metal processing).
Finally, the knuckle joint presses operate the hammer by means of a system of levers, which transform the circular motion into alternating rectilinear motion, powered by an electric motor.
As with hydraulic presses, due to the time required for the reversal of motion, the springback in the components is minimal.
Compared to hydraulic and eccentric presses, the force during the stroke is more constant,
and so is the precision.