Punching
& punching machines - more than just a special form of drilling
A punching machine,
also known as a punches for short, is a machine tool for cutting materials into
a specific shape. It is a separating process without deviations (deep drawing)
in the third dimension.
The way a punch
works is comparable to that of plate shears, with the difference that the
knives of a punching machine form one or more closed contours. Furthermore,
punching tools usually do not have a cutting angle, which means that the entire
cross-section must be cut through in one operation. The advantage is that the
stroke of the punching tool is small, but the cutting force required is high.
Depending on the high cutting force of punches and punching machines, high
levels of noise are generated during punching. That is why punches and punching
machines are very often chambered.
Punches
& punching machines - structure
The components find
their place in a complete machine frame. From bottom to top, the structure is
as follows: foot, table, die holder, die, material feed area, punch, punch
holder and punch drive.
The die and the
punch are the tools of the punching process. The material is inserted between
them and the punch plunges into the die during punching. For a clean, burr-free
punching result, it is necessary that the cutting clearance between punch and
die is precisely maintained over the entire contour. The distance between punch
and die varies, depending on the material to be punched, but is not more than
10% of the material thickness.
The punched-out
part falls out of the die and can be conveyed out via a basket or a conveyor
belt. The punched-out part can, however, be scrap waste or also the good part.
In the simplest
case, the punching force can be generated manually using a lever or a lever
mechanism. The degree of automation can be increased by hydraulic drives or
eccentric drives.
Punches
& punching machines - variants
The simplest form
of the punch is the version with manual actuation. The material is manually
inserted into the punch and the punching process is carried out using a
two-hand control. Then the stamped part is removed again manually. This process
is only suitable for small quantities.
Automatic feeding
of the material into the punching machine is ideal for larger numbers of
workpieces. For example, a driver can unwind material from a coil and cycle it
into the work area of the punching machine. A punching process then takes place
after each feeding cycle.
The degree of
automation increases when using automatic punching machines, with the
transition from the punching machine to the automatic punching machine being
fluid here too. The degree of automation can be increased by quick-change
tools, automated tool changes, automatic feed and discharge and NC or CNC
controls.
Quick-change tools
contain the die and the punch together with guides and return springs in one compact
component. This has the great advantage that the punch and die are 100% aligned
with one another immediately after being installed in the punching machine.
Guides or pins ensure the perfect position of the tool in the machine tool.
Punching tools arranged
one after the other in punching machines can also work out contours which
cannot be realized in one work step.
Depending on the
shape of the component, the material, the number of pieces or the material
thickness, it makes sense to use either a punch, a punching machine or an
automatic punching machine. As a result of chaining machines new possibilities
of complexity in workpieces are possible. Chaining is also conceivable with a
bending machine, performing the next work step after the punching machine.
There are also
machine manufacturers who produce combined stamping and bending machines. The
combination of a punch and a deep-drawing process can also be found in presses.
After the deep-drawing process, the edge of the workpiece is cut off inside the
pressing tool. This cut corresponds to the punching process.
From a certain
point of view, the use of laser cutting systems, plasma cutting systems or
water jet cutting systems makes sense, but that is a different topic.
Different
variations of punching in punching machines
During the punching
process, an embossing process can also take place due to a shortened stroke and
execution of the tool. When embossing, the material is not cut through, but
logos, lettering, technical data or slugs and beads are embossed.
tramao and
punches or punching machines
tramao offers you a large selection of used and new
punching machines. You will also find the right service companies for
purchases, repairs and spare parts procurement on tramao.de.
On tramao you will also find a wide range of
machine accessories for punching machines such as tools (dies and punchers),
lifting cylinders, feed and discharge devices and much more.
If you decide to buy a new or used punching
machine, you will find a large selection of well-known manufacturers such as
Euromac, Trumpf, Sandt, Weingarten, Amada, Finn-Power or Bruderer on tramao.