Friday, March 15, 2013

DESIGN AND MANUFACTURING OF A PROGRESSIVE TOOL


1.INTRODUCTION
1.1 NECESSITY OF PROFESSIVE DIE IN MASS PRODUCTION
In today’s industrial era the main basic thing for any industry is to produce 
and manufacture the product with shortest Lead time and with greatest accuracy. Also grate care is taken to maintain international quality and to over come these problems we can o for progressive dies.Progressive die is widely used in our present day manufacture industry. These dies play a vital role in each and every operation that lead to manufacturing of certain components. Further the dies are classified according to the type of operation performed by them.

SOME OF THE IMAGES OF PROGRESSIVE TOOL ARE
(A)Piercing:
The piercing is the operation of production of hole in a sheet metal by the punch and the die. The material punched out to form the hole constitutes the waste. The punch point diameter In the case of piercing in less than or equal to the work material thickness. The punch governs the size of the hole and the clearance is allowed on the die. 
(I) bending :
The punching operation is similar to the piercing operation. While punching the formation of the hole is the desired result. The difference between the punching and the piercing is that in the case of punching a cylindrical hole is produce, where as in the case of piercing the hole produced may be of any other shape. The size of the hole is determined by the size of the punch and the clearance is allowed on the die.

©Perforating:
The perforating is the operation of production of a number of holes evenly spaced in a regular pattern on a sheet metal.

(D)Blanking:
The blanking is a operation of cutting of flat sheet of the desired shape the metal punched out is the required product and the plate with the role left on the die goes as waste. While blanking 

(d) Cutting off: 
The size of the blank of the die and the clearance is left on the punch.
The cutting off is the operation of shearing a piece from a sheet of metal or a bar with a cut along a single line. The cutting off operation can be performed along a straight line or a curve.
(E)Parting:
The parting is the operation of cutting a sheet metal in two parts. Unlike cutting off operation, some quality of scraps is removed to shear the work piece in two parts.
(f)Notching:
The notching is the operation of removal of the desired shape from the edge of a plate. This operation removes a small amount of material from the edges of a strip or a blank. Nothing serves to shape the outer contours of the work piece in a progressive die or to remove excess metal before a drawing or forming operation in a progressive die.
(g)Embossing:
The embossing die is used to press letters and number onto a sheet metal or on predawn piece part. The forms of the script are engraved and polished usually the punch bears the raised from and die bears the cavity.
(h)Coining:
Coining is the process of pressing cold material in a die so that it flows into the engraved profiles on the die face. Coining differs from embossing such that in coining the metal flows, where as in embossing the metal thus not changes in thickness to great extent.
round straight axis which extends completely across the material. The result is a plane surface at an angle to the original plane of the flat blanked component. Metal flow is uniform along the bend axis. 
(j)Forming:
The operation of forming is similar to bending aspect that the line of bend is along a curved axis instead of a straight. Metal flow is not uniform as in bending because it may be localized to some extent depending up on the shape of the work piece.
(K) Drawing:
In drawing a flat blank is transformed in to a cup or shell, the parent metal subjected to several plastic deformation. Shell forms produced may be cylindrical or rectangular with straight tapered sides.

NEED FOR DESINGNING OF PROGRESSIVE DIE
Die design, a large division of tool engineering is a complex, fascinating subject. It is one of the most exciting of all areas of the general field of tool designing. The die designer originates designs of the die employed to stamp & form parts from sheet metal, assemble parts together & perform variety of other operations,
Today `s industrial era demands something that is simple and economical .in this regard the progressive die will play a very important role. A progressive die is a die which can perform a number of operations at each press of ram. And hence will be the brightest future in the mass production area. Let`s see some of the advantages and disadvantages.

1.2ADVANTAGES AND DISADVANTAGES OF PROGRESSIVE DIE.

Advantages:
• If the pierced holes are too near to the outer edge of the piece part, the blanking punch of a compound die which accommodates the piercing dies will be come very weak.
• The posses a very big disadvantage of punch breakage either during manufacturing or during the course of the die life. For such piece parts the best solution is always a progressive die.
• Compound dies generally uses more than one press along with secondary press. Where as progressive die needs only one press even for to work stations.
• Progressive dies increases the annual production to a high volume(thus high scale production only through progressive die) 

Disadvantages:
• Parts produced from compound die are very accurate and identical as all operations are carried out in a single station. this is made possible because the accuracy the part does not 
• Depend on the accuracy of the advance of the strip or the accuracy of the layout of the stations as in the progressive die.
• Scrape stocks from other dies can be economically employed to produce piece part in a compound die whereas progressive die always need stock strip sheared to size.
• In a compound die burrs resulting from piercing and blanking are on the same side of the piece part. Piece parts produced by a progressive die have the burrs on the opposite sides.
• Die cost incurred in manufacturing a compound die is lesser then that of a progressive die made for the same component because of its smaller size and easier manufacturing methods warranted.
Thus we need to design a progressive die for better scale of production and effective use.

1.3METHOD OF DESIGNING A PROGRESSIVE DIE 
• The first step of designing a progressive die is to study the piece pat drawing carefully and to plan the operations to be carried out in different stations.
• The drawing of the stock strip is laid out as it will appear after it as gone through all stations, till a finished piece part is removed from it.
• It should be dimensioned and should carry all information’s necessary to start with the tool design like the feed direction, the amount by which the strip advances after each stroke of the press.
• The blank must be positioned in the strip so that a maximum area of the strip is utilized for the production of the stepping.
• The existence of numerous die stations having many punches tends to weaken the over all die. Than one or more idle stations, where now operations or performed should be included. The addition of an idle station is also called for when the punches from two active stations are too close to each other.
• Although idle stations are often included to strengthen a die, at times they are also included in order to case of die maintenance to provide flexibility in the event that additional need to be added later.
• Most stamping operations are carried out on parts less than 200mm is size using progressive die. Large parts are not usually produced on progressive dies because the size of die becomes exorbitantly large.
• Progressive dies can produce a complete part without any secondary operations. Then are capable of high speeds & high degree of accuracy they can be engineered to produce very complex parts.

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