Design of Progressive Tool (prototype) for Washer Manufacturing

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INTRODUCTION

Press working techniques utilize manufacturing tooling equipment design have greatly opened the way for mass production of articles such that most

of the necessities like automobiles, refrigerator, office furniture and domestic wares of sheet metal have come within the rich of common man.

Press working may be defined as a chip less from sheet metals manufacturing process by which various components are made from sheet metals. This process is also termed as cold stamping. The machine used for press working is called a press.

NECESSITY OF PROGRESSIVE 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 overcome these problems we can go 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.

OPERATIONS

There are various operations based on the shearing process.

PUNCHING

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.

Punching or piercing is a cutting operation by which various shaped holes are made in sheet metal.in punching hole is the desired product and the material punched out to form the hole is waste.

BLANKING

Blanking is the operation of cutting a flat shape from sheet metal. The article punched out is called BLANK and is required product in the operation. The hole and material is left behind is discarded as waste.

PERFORATING

In perforating operation we punch a number of holes in a sheet .these holes are very small and close to each other.

NOTCHING

In this operation we remove pieces or various shapes from the edge of the sheet, strip or blank.

PARTING

Shearing the sheet into two or more pieces usually when the adjacent blanks not have matching contour is called parting.

[pic 3]

FIGURE: Blanking and piercing operation

LANCING

This is a cutting in which a hole is partly cut and then one side is bent down to form a tab removing any material.

TRIMMING

This operation consists of cutting unwanted excess material from the periphery of a previously formed component.

SLITTING

It refers to the operation of making incomplete hole in a workpiece. Slitting is similar to opening cans; the operation is carried out with a pair of circular blades that follow either a straight line or a circular or curved path. A slit edge normally has a burr, and it may be removed by rolling. There are two types of slitting equipment, one is the driven type with powered blades, and the other is the pull through type where the strip is pulled through the idling blades.

[pic 4]

FIG2: Die cutting operations.

ADVANTAGE OF PRESS WORKING:

1. Small weights of fabricated parts.

2. High productivity of labour.

3. High efficiency.

4. High volume, low cost production.

5. Predictable strength characteristics.

6. Uniformity of parts.

7. Low cost material.

TYPES OF DIES

Dies may be classified according to the type of press operation and according to method of operation.

On the basis of press operation type

According to this criterion, the dies are classified on the basis of the operation performed over the work piece. There are two types of dies based on this, cutting and forming dies.

CUTTING DIES

These dies are used to cut the metal. They utilize the cutting or shearing action. The cutting dies include blanking dies, piercing dies, perforation dies, notching dies, shaving dies, nibbling dies etc.

FORMING DIES

This die changes the appearance of the sheet without removing any stock.no cutting takes place in this case. These dies include bending dies, drawing dies, squeezing dies etc.

On the basis of method of operation

According to this criterion, the dies are classified as

Simple dies

Simple dies or single action dies perform single operation for each stroke of the press slide. The operation can be cutting or forming operation.

For increased productivity, two or more basic metal forming operation can often be combined in dedicated tooling. Beyond the single operation per press-stroke, other options with dedicated tooling include compound dies, progressive tooling, transfer die system, and slide forming.

Compound dies

Compound dies are hard tooling options that allow two or more operations to be combined into one. A compound blank and pierce, for example permits the entire perimeter and all holes to be cut in one stroke of the press. This produces the closest feature-to-feature tolerances, flattest part, and easiest to control burr height.in