Punching Machine

Machine structure

Punching machines can be designed with different frame shapes. One option is the C frame, as used. This offers special benefits.The machine frame absorbs the forces 16 required for punching 1 . The punching head 2 is permanently mounted on the machine frame.

The C-shaped design of the machine frame means that the machine is open at the front and readily accessible. For it is at the front that the working area is located.

The sheets 22 can be moved freely in the working area. They are positioned exactly underneath the punch and then machined. The finished part can leave the machine 7 , for example, via the part removal flap.

Punching is normally a non-continuous movement, i.e., positioning – stopping –punching . In certain machining processes such as marking 14 or when using roller technology 13 the tables move continuously with the sheet.

1 Control panel

2 Machine table

3 Switch cabinet

4 Hydraulic unit

5 Transverse rail with linear magazine 5

6 Punching head 2

7 Part removal flap

Tool magazine

The tools 3 required for processing are held ready in a tool magazine on the punching machine 4 . These tools can be changed automatically by the machine as required. As a wide range of different tools can be held ready for use, e.g., tools for punching 9 , forming 11, marking 14 or step less shearing 10. Tool magazines are available in different variants. One is the linear magazine, which is installed axially in the C frame parallel to the machine table.

The linear magazine is mounted on the transverse rail of the machine and offers space for up to 23 cassettes as well as the clamps used to secure the sheet 22.

The tool cartridges each contain a tool set, with the punch, stripper and die 6 already having been properly aligned to each other. Compatible magazine stations allow tools of any type and size to be arranged at each magazine station.

The linear magazine is easily accessible for set up. Tool cartridges are conveniently dropped into the linear magazine by the operator.

To change the tool during operation, the linear magazine moves the required tool into position in front of the punching head 2 . The tool set 3 is then inserted in the tool adapter, where it is removed from the tool cartridge and clamped in place mechanically. This can occur in less than three seconds.

If the linear magazine does not have sufficient space, there are additional external tool magazines, e.g., the Tool Master 8 , which holds another 70 tools at the ready. When one of these tools is required, it is first of all automatically inserted in the linear magazine and from there switched to the punching head 2 . The tool magazine plays a key role for automation 8 , for example, when the punching machine 4 is scheduled to operate during an automated shift or at the weekend.

Die

In a tool set 3 the die is the counterpart to the punch. It counteracts the ram force and permits punching 1 .

Applications such as downward forming 11 are not possible with a fixed die. Forming would catch with the die. The solution here is to use a descending die, which moves down after the punching stroke and makes room for forming. This increases process reliability as collisions between the die and material can be ruled out. The descending die also makes scratch-free processing of components possible since it is lowered before every positioning motion, so preventing contact between the sheet 22 and the die.

Even more extensive applications can be performed using an active die, which is a separate axis that moves the console with die holder and die. The active die thus functions like a second punching head 2 , which leads the forming tool 11 up from the plane of the sheet. After forming the die draws the tool back under the sheet. The sheet 22 is not lifted during forming. Typical forms are louvers, cups and extrusions, which can project up to 12 millimeters from the sheet surface. The active die makes integrated flattening possible. Using this function even highly perforated sheets can be taken even 21 from the machine.

Removal

Punching 1 produces different-sized sheet metal parts and scrap. There are various options for removing both from the machine 4 after processing and sorting them out. Different processes are generally combined here.

Manual removal is particularly important if parts are too large to fit through the part removal flap or when parts must not get scratched from falling onto each other.

If the finished part has not been completely detached from the scrap skeleton 23, and there are still little connections to the skeleton, they are known as micro joints.

The sheet metal parts are still attached to the scrap skeleton. They are then pressed or shaken out by hand. Unlike single part automation, this automation method 8 involves subsequent manual intervention.

Automated parts removal

There are different ways of discharging finished and waste parts from the machine into containers without manual intervention 8 . Here it is even possible to separate different-shaped finished parts and waste parts from each other and sort them into different containers.

Sorting and selective removal of good and waste parts can be carried out with the help of a sorting flap. The removal path depends on the position of the sorting flap.