After giving you a definition of machine tools yesterday, today we are going to speak about sheetmetal machines.
Sheet metal is simply metal formed into thin and flat pieces. It is one of the fundamental forms used in metalworking, and can be cut and bent into a variety of different shapes.
Thicknesses can vary significantly, although extremely thin thicknesses are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are considered plate.
Materials:
– Stainless steel
– Aluminium
Here is an overview of the main categories of sheetmetal machines and their definition:
Definition of bending machines
Metalworking process that allows the bending of sheet metal. A cornice brake only allows for simple bends and creases, while a box-and-pan brake also allows one to form box and pan shapes. It is also known as a bending machine or bending brake.
Definition of deep drawing machines
A sheet metal forming process in which a sheet metal blank is radially drawn into a forming die by the mechanical action of a punch. The process is considered “deep” drawing when the depth of the drawn part exceeds its diameter.
This is achieved by redrawing the part through a series of dies. The flange region (sheet metal in the die shoulder area) experiences a radial drawing stress and a tangential compressive stress due to the material retention property. These compressive stresses (hoop stresses) result in flange wrinkles (wrinkles of the first order). Wrinkles can be prevented by using a blank holder, the function of which is to facilitate controlled material flow into the die radius.
Definition of laser cutting machines
Cutting sheet metal can be done in various ways from hand tools called tin snips up to very large powered shears. With the advances in technology, sheet metal cutting has turned to computers for precise cutting.
CNC laser involves moving a lens assembly carrying a beam of laser light over the surface of the metal. Oxygen, nitrogen or air is fed through the same nozzle from which the laser beam exits. The metal is heated and burnt by the laser beam, cutting the metal sheet. The quality of the edge can be mirror smooth and a precision of around 0.1 mm (0.0039 in) can be obtained. Cutting speeds on thin 1.2 mm (0.047 in) sheet can be as high as 25 m (82 ft) a minute.
Most of the laser cutting systems use a CO2 based laser source with a wavelength of around 10 um; some more recent systems use a YAG based laser with a wavelength of around 1 um.
Definition of press brake forming machines
This is a form of bending, used for long and thin sheet metal parts. The machine that bends the metal is called a press brake. The lower part of the press contains a V shaped groove. This is called the die. The upper part of the press contains a punch that will press the sheet metal down into the v shaped die, causing it to bend.
There are several techniques used here, but the most common modern method is “air bending”. Here, the die has a sharper angle than the required bend (typically 85 degrees for a 90 degree bend) and the upper tool is precisely controlled in its stroke to push the metal down the required amount to bend it through 90 degrees.
Typically, a general purpose machine has a bending force available of around 25 tonnes per metre of length. The opening width of the lower die is typically 8 to 10 times the thickness of the metal to be bent (for example, 5mm material could be bent in a 40mm die) the inner radius of the bend formed in the metal is determined not by the radius of the upper tool, but by the lower die width. Typically, the inner radius is equal to 1/6 of the V width used in the forming process.
Punching – is performed by placing the sheet of metal stock between a punch and a die mounted in a press. The punch and die are made of hardened steel and are the same shape. The punch just barely fits into the die. The press pushes the punch against and into the die with enough force to cut a hole in the stock. In some cases the punch and die “nest” together to create a depression in the stock.
Definition of water jet cutting machines
A water jet cutter, also known as a waterjet, is a tool capable of slicing into metal or other materials using a jet of water at high velocity and pressure, or a mixture of water and an abrasive substance.
If you are looking for a machine mentioned above, do not hesitate to check our used sheetmetal machines.
