The hydraulic press brake of today is the result of constant evolution. Just like cars, for example, which have become high-tech means of transportation, the press brake is now a concentrate of technological and mechanical innovation. And yet, in the case of both the car and the press brake, the basic mechanical components are still basically the same as they were at the beginning. However, they have been improved and refined over time.
In order to understand the fundamental steps in the history of sheet metal bending, we suggest you to go back in time to discover some of the history of these historical machine tools that are essential for our customers today.
Mechanical press brakes
Mechanical folding machines are still used in many workshops to perform marginal machining, even though they are now considered prohibited from a safety point of view. Therefore, they can logically no longer be used by the staff. In the past, the best-known mechanical folding machines were made by Mariani or Omag and were characterized by extremely fast movement and high pressure force.
Hydraulic press brakes type "RG" Promecam
Born in France thanks to the intuition of the French-Italian Roger Giordano, the hydraulic folding machines type RG Promecam are compact machine tools.
Their most obvious feature is the movement of the bed, different from all other press brakes.
Indeed, if it is generally the upper part - called "crossbar" - that goes down, in this case, it is the bench that goes up.
The movement is obtained thanks to the thrust of a central hydraulic system. Simple and very reliable, they have practically made the history of the Italian press brake but not only. Nowadays, they do not comply with the safety regulations, as they do not have the speed change point and are not equipped with the modern safety systems.
Therefore, they can only work if they are adapted with specific kits.
They were distributed for a long time and it is still not uncommon today to find them in many workshops that are still operational; after the Second World War, they represented a real revolution, since the bench prevented the natural bending of the sleeper.
Moreover, since the latter was rather low and compact, it allowed to obtain large closed profiles that could "embrace" the upper part of the machine.
Synchronized hydraulic press brakes
At present, the hydraulic synchronized press brake is the most common modern machine.
It guides the movement of the upper crossbar by means of two independent hydraulic cylinders operated by proportional valves.
In this way, the machine is more versatile and allows the operator to act on the two cylinders independently to modify the descent of the crossbar and prevent possible irregularities of the sheet. In fact, it often happens that a piece bends more on one side than on the other due to the variability of the raw material.
The numerical control of a synchronized hydraulic press brake is much more advanced than the positioner of the torsion bar press brake.
The CNC allows the operator to make many adjustments: from parking time in "bottom dead center" to fold speed at decompression.
The electric press brake
From a chronological point of view, they represent the latest evolution of press brakes and, even today, they are seen as a borderline solution for specific requirements.
They guarantee speed and repeatability, as well as low energy consumption. However, they are less versatile and have much higher costs than synchronized hydraulic folders.
Basically, there are two techniques to drive an electric folder: with recirculating ball screws or with adapted belts.
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