Punch press

The shearing or scissors is used for cutting a material by two past each other moving cutting ( DIN 8588 ). The material is thereby sheared by shear forces.

In sheet metal processing this separation process is one of the most commonly used manufacturing processes. Tools for this separation process are the scissors (household shears, plate shears, plate shears, cable cutters ), as well as, inter alia, punch presses, hydraulic cutters ( " jaws of life " ) or nibblers.

Cutting process

Material separation by shearing can be divided into four phases:

Decisive for the quality of the interfaces in production are the material thickness, the cutting gap in relation to the material thickness (3-5 % for open, 5-10 %, with cut closed, during fine blanking 0.5-1 %), the state of wear of the cutting tools, the material type, the tool guide and the part geometry.

The quality of the internal shape is greatly influenced by the punch, since only a relative movement between the punch and the internal shape take place. For an external shape is considered appropriate for the inserts.

Method

From the position of the workpiece boundary we distinguish the following methods:

• Cut - When you cut the part is usually made of a metal strip ( coil), partly cut out of sheet metal blanks also. The strip after cutting waste, the cutting line during cutting is always closed. The cutting edge of the outside lead to the workpiece. See also punching. The process is not to be confused with pruning ( see below).
• Punch - When punching one or more holes are cut into the workpiece. The shape of the holes or openings is arbitrary, the cut line is always closed when punching. The Cut-out is in the drilling waste. See also punching.
• Cut off - When cutting the workpiece is cut off, usually without waste of a metal strip. The cut line is open and runs straight across the sheet metal strip. The curve of the cut line is determined to be produced by the shape of the workpiece. See also Plate Shear.
• Notching - When notching one or more pieces from the side of a sheet metal blank (workpiece) to be cut out. The intersection of this process is open and begins and ends at the workpiece edge of a page.
• Pruning - Pruning is the cutting of a deep- drawn part after forming to its exact dimensions.
• Cut - During cutting of the sheet metal blank is cut along a line which ends in the workpiece and is thus not closed. The incision usually occurs together with the bending deformation.

Furthermore, the method can be divided according to the following criteria

• Form of cutting Open Cut
• Closed Cut

• Shear blade
• Slitting blades

• Full - edged cutting
• Crossing - cutting

• Separate