Blanking Machine

Blanking Machine Points : Blanking Machine, Definition Definition Blanking is a process of cutting or shearing a blank from sheet or strip material I the production of many articles from sheet metal under a press or by spinning, the process of blanking is often the first operation in the production cycle. Simply expressed, blanking is the process of shearing from sheet or strip metal a blank of a given shape.

The term normally implies two things:
(i) To the process is carried out under some type of press, and
(ii) To the entire edge of the resultant blank has been subjected to a shearing operation.

Reduced to simplest terms, a set of blanking tools consists of a bed and punch. The latter is attached to the ram of the machine and the former is clamped to the bed to the press. When the tools are set the punch should first enter the bed without touching the sides is such a manner as -to damage the cutting edge. The clearance between the cutting edges is regulated t suit the thickness of the metal to be cut with the tools in position~ the punch should be adjusted to enter the ; for the minimum distance necessary to give complete shear. If it is permitted to enter too far, be punch is subjected to unnecessary wear. With tools in position and properly set the tail end of downward stroke of the ram forces the punch to carry the materials it covers in the bed. The rounding metal cannot enter hence is sheared off In order to obtain a blank fret from burr. That is, with a clean sheared edge, particular attention should be given to the clearance and condition of the cutting edges. A typical layout for a small set of blanking tools. The punch is of the built. Type having a low- carbon steel shank, which is fitted in the press ram, and a edge held by screws on to the face. The aim of having a built-up ‘punch of this type is twofold it gives a strong edge that will withstand the abrasive action for a considerable period without losing its size and it permits a great economy in the use of expensive alloy steel. In this particular design the cutting edge is held in position by means of a spigot and hollow-head screws. To assist the clamping and make up the “shunt height” of the press, the bed is mounted on a bolster plate.

Theoretically the punch should fir within the die with a uniform clearance the approaches zero on its downward stroke it should not enter the die but should stop just as its base aligns with the top surface of the die. In general practices the clearance is between 5 to 7% of the thickness and the punch enters slightly into the die cavity.