Press brake

In a press brake, press brake or bending machine sheet metal parts such as cowlings, housing or machine components are manufactured by bending. The press is basically composed of the punch and the bending die. To be added: a tool magazine and tool changing device, it is called a Gesenkbiegezentrum.

When flanging is a sheet metal between the punch and die. The punch is then lowered, the sheet is pushed into the die and assumes the shape of the die. By a non- complete lowering, any smaller bending angle can be produced. In more complex profiles, several cuts are possible, while the sheet is positioned differently and reduced the stamp again after the first reduction. The press must not be set up again for this, which is why it is a very economical way of shaping.

Another machine, the plates flex and abkantet, the bending machine.

Security

At press brakes up to year 2002, the protection of the operator's hands by a two-hand safety circuit ( ZHS ) is guaranteed (according to DIN EN 574 ) with one or more control panels. The dangerous closing movement occurs only when the operator actuates both switches of the console at the same time. However, this type of sheet metal processing is no longer appropriate for two reasons. Due to the high complexity of current sheet structures, most parts have to be performed during the bend. Furthermore, the method of ZHS is very time-consuming and therefore costly. This is a cause that it often comes to the conscious bypass the two-hand control in older machines. Furthermore, the ZHS is bypassed in order to hold the part can. To circumvent these problems, new machines are equipped as standard since 2002 with revolving safety devices.

On both sides of the plunger retainer arms are mounted, on which at the bottom of the security system is installed. Transmitting and receiving unit of the system are mounted such that the lower edge of the die is monitored. Here are various monitoring concepts, but all of which function visually.

The most common variant, this monitoring using one or more laser beams dar. this case, the interruption of the beam is detected as a trigger for an emergency stop of the machine. In order for these systems a box bending, that is, to a bend in an already canted legs of the sheet enters the security area of ​​the cameras perform, the operator must, after the interruption of the laser beam is detected, acknowledge this by means of the foot switch. Or the front laser beams are muted once for the box-bending function.

New developments

During the development of security systems is very far advanced, there are in the area of the holding arms still some development needs. In order to protect older machines ( built before 2002) with a traveling safety device, the holding arms must be adapted to the given conditions. Manufacturers of new machines are the problem not over, because they have all possibilities during the design stage of the machine to integrate the holding arms. However, both versions have in common is that in most poor there is no possibility, the state of the security system (active / inactive) display. This is necessary because many operators whose press was equipped with a traveling safety device, less careful work, their assumptions of complete protection during bending. They do not realize that, from the " mute" point or, for example, in the method of the backgauge the system is idle. To counteract this misinformation offer the latest developments in the retrofit sector on recently integrated into the arm, led lights an additional visual status indication of the system.