MAJOR PROJECT REPORT

DESIGN OF COMPOUND DIE SET

WITH HYDRAULICPRESS

SUBMITTED TO: - SUBMITTED BY:-

Mechanical Engg. Deptt.

Ramkaran [3709349] Sanjay Singh [3709356]

Gurpreet [3709318] Deepak Kumar [3709313]

SELECTION OF PROJECT

We engineering students have certain skills, traits and motives. Our psychological make up tells us what traits and motives we posses, thus giving the solution to the problems of different nature and magnitude at different time being encountered.

The project activity is essentially a person oriented work which initially itself is a big task to identify, explore and then selection of the same.

After exploring the sound technical know how and skills we are possessing, the environmental set up in workshop, the availability of the resources, the manufacturing process involved, the expert guidance and help which can be sought, complexity of technology, economy of production and time schedule of completion of task. We finally select project title “COMPOUND DIE AND HYDRAULIC PRESS FOR WASHER CUTTING”.

This project involves intensive to extensive exposure to a no. of common types of manufacturing operations to be done on the job such as turning, drilling, cutting, threading etc. thus further increasing the technical know-how skill of we people.

This project emphasizes the trouble and problem being encountered at various levels of its production, from the procurement of material to operations and processes in giving final practical shape to the product; resulting us to know the difficulties being faced on the actual production floor of an industry.

WHAT WE HAVE INNOVATED IN THIS PROJECT

We are designing a hydraulic press for small scale industry which gives better production because as Compared to other press like electric their cost of maintenance and equipment is high .Whereas hand operated press creates lots of fatigue in workers as worker have to give force by his hand and as well as feed.But in foot operated die we can apply foce by legs and feed by hand that is why this type of press will be useful in small scale industries.

INTRODUCTION

Press working may be defined as a chip less manufacturing process by which various components are made from sheet metal. This process is known as cold stamping. The machine is used for press working is called a press. The main features of the press are: a frame which supports a ram or a slide and a bed, a source of mechanism for operating the ram Inline with and normal to the bed. The ram is equipped with suitable punch. A stamping is produced by the downward stroke of the ram when the punch moves towards and into the die block. the punch and die block assembly is generally termed as a die set or simply as the die press working operation are usually done at room temperature.

A die is a specialized tool used in manufacturing industries to cut, shape and form a wide variety of products and components. Like molds and templates, dies are generally customized and uniquely matched to the product they are used to create. Products made with dies range from simple paper clips to complex pieces used in advanced technology.

COMPOUND DIES:-

It performs two or more cutting operations during one stroke of the press at one station only. In order to do this both the upper and lower members of the die set carry punching and blanking elements which are directly opposite to each other.

WASHER BY COMPOUND DIE

PRESS OPERATION:-

The sheet metal operation done on a press may be grouped into two categories, cutting operation and forming operation. In cutting operation the work piece is stressed beyond its ultimate strength. The stress caused in the metal by the applied force will be shearing stress. In formatting operation the stress are below the ultimate strength of the metal. In this operation there is no cutting of the metal but only of the contour of the work piece is changed to get the desired product. The stress included in the metal during the bending and drawing operations is tensile and compressive and during the squeezing operation these are compressive.Below we give the definition of the various press operation:-

A)Blanking:- Blanking is the operation of cutting a flat shape from sheet metal. The article punched out is called the ‘blank’ and is the required product of the operation. The hole and metal left behind is discarded as waste. It is usually the first step of series of operations

B) Punching (piercing):- It is a cutting operation by which various shaped holes are made in sheet metal. Punching is similar to blanking except that in punching the hole is the desired product, the material punched out to form the hole being waste

Advantages of metal stamping:

Sheet stamping is an advanced technique of mechanical working. It has got the following option:

1. Small weight of fabricated part.2. High productivity of labour.3. High efficiency of technique as regards the fabrication of items of

diversified shape.4. High volume, low cost production.5. Predictable strength character stick.6. Uniformity in parts.7. Low cost material.8. Less labour consuming.

All the above advantages have made stamping very attractive to a host of industry, particularly to automotive, aircraft, electrical engineering and other.

PRESS WORKING EQUIPMENT:

We will use a foot operated press using a lever advantage.

Lever : A lever is a mechanism that can be used to exert a large force over a small distance at one end of the lever by exerting a small force over a greater distance at the other end of the lever.

In general the effort force can be expressed as

Fe = Fl dl / de         (1)

where

Fe = effort force (N, lb)

Fl = load force (N, lb) (note that weight is a force)

dl = distance from load force to fulcrum (m, ft)

de = distance from effort force to fulcrum (m, ft)

Requirements of press tool design:

The press tool design should suit the type of production it will be used for, that small batch, large batch, or mass production. The press tools should meet the following requirements:

1. The dimensional accuracy and surface finish of stamping should conform to the drawing and specification.

2. The working parts of the tool must be adequately strong, durable and easily replaceable when worn out.

3. The die should ensure described hourly output, easy maintains, safe operation and reliable fastening in the press.

4. The die should be designed in such a way that far as possible standards components are used for its manufacture.Asfew special parts as possible should be used in its design.

5. The scrap in the stamping operation must be kept as a minimum by

suitable designing the strip layout. The percent utilization of the material is given as:

Percentage material utilization = total area of blank cut / area of uncut strip *100Normally the value of this factor is 70 to 80%.

Press tool components:

The press tool components may be divided into the following types:

1. Working components, which participate in the shaping of parts: dies, punches and their section.

2. Structural components, which serve for joining the working components to one another and to press: upper shoe, lower shoe and shanks.

3. Guiding components, which sure accurately alignment of the upper shoe with the die in operation: guideposts and bushing.Guide post can also facilitate tryout of the press.

4. Feeding components, which feed the stock strip or blanks to the stamping station.

5. Locating and locking components, which provide for an accurate positioning of the stock or the blanks in the die and fix it in the places while the operation is performed?

6. Stripping components, which strip and remove the blanks and the scrap from the working components after the operations is over: strippers push off pins, knockouts.

Press tool components

PRESS WORKING TERMINOLOGY:-

A simple cutting die used for punching and blanking operation is shown. The definitions of the main component of the die and press are given:-

1) Die set:- It is unit assembly which incorporates a lower and upper shoe, two or more guideposts and guidepost bushings

2) Die:- The die may be defined as the female part of a complete tool for producing work in a press. It is also referred to a complete tool consisting of a pair of mating members for producing work in a press.

3) Die block:- It is a block or a plate which contains a die cavity.

4) Lower shoe:- The lower shoe of a die set is generally mounted on the bolster plate of a press. The die block is mounted on the lower shoe. Also, the guide posts are mounted in it.

5) Punch:- This is the male component of the die assembly, which is directly or indirectly moved by and fastened to the press ram or slide.

6) Upper shoe:- This is the upper part of the die set which contains guidepost bushings.

7) Punch plate:- The punch plate or punch retainer fits closely over the body of the punch and holds it in proper relative position.

8) Back up plate:- Back up plate or pressure plate is placed so that the intensity of pressure does not become excessive on punch holder . The plate distributes the pressure over a wide area and the intensity of pressure on the punch holder is reduced to avoid crushing.

9) Stripper:- It is a plate which is used to strip the metal strip from a

cutting or non cutting punch or die. It may also guide the sheet.

10) Knockout:- It is a mechanism, usually connected to and operated by the press ram, for freeing a work piece form a die.

11) Pitman:- It is a connecting rod which is used to transmit motion

from the main drive shaft to the press slide.

12) Shut Height:- It is the distance from top of the bed to the bottom

Of the slide, with its stroke down and adjustment up.

13) Stroke:- The stroke of a press is the distance of ram movement from its up position to its down position. It is equal to twice the crankshaft throw or the eccentricity of the eccentric drive. It is constant for the crankshaft and eccentric drives but is variable on the hydraulicpress.

Working of a cutting die:

The punch holder is fastened directly to the ram of the punch press and the die shoe is fastened to the bolster plate of the press. Guide post may be used as to better align the punch holder with the die shoe. These three main components constitute what is known as the die set. a die set can be had two guide post located at the rear of the die set ,diagonally ,one at the back and in the front of the die set , or with four guide post ,one in each corner of the die set .The lower ends of the guide post are press fitted into the die shoe. At upper end, the guide posts have a slip fit with the guide bushing which are press fitted into the punch holder. With this, the guide posts have a free movement in the bushings. The punch is fastened to the punch holder and the die block is fastened to the die shoe. The punch is aligned with the opening in the die block. Since both the punch and die block act as cutting tools they are hardened.

The cutting action takes places during the downward movement of the punch into the die block. After the cutting action, the elastic recovery in the strip material takes places. Due to this the size of the blank increases and that of the hole in the strip decreases. So at the end of the cutting action, when the punch starts to move upward the scrap strip cling to the punch and the blanks get clogged in the die opening. To remove the scrap strip from the punch surface a stripper is used to avoid clinging of the blank in the die opening; the walls of the die opening are tapered.

The usually happens with thin blanks which have been treated with a lubricant. To help the blanks free itself from the punch face, pushes off pins are provided which are fitted into the punch body.

The most popular design is a straight, round plunger with a sliding fit in the punch body. It is held in the places by a light compression spring and a set screw. If at the end of body, a pilot is to be provided, then the push-off pin is located off center. When the space available for a comparisons spring is insufficient, a flat spring is used.

In the case of very small punches no space is left to provide the push-off pin. In such cases, the sticking of the blank to the punch face may be avoided by changing the shape of punch bottom. With this, the oil seal or vacuum created by the oil films is broken and tendency of the blank to stick to the punch face is greatly decreased. The drawback of this method is that the blank gets distorted. Due to this method is suitable for punching operations.

Principle of metal cutting:-

The cutting of sheet metal in press work is a shearing process. The cutting action is explained with the help of fig. the punch is of the same shape as of the die opening except that it is smaller on each side by an account known as ‘clearance’. As the punch touches the material and travels downwards, it pushes the materiel into the die opening. The material is subjected to both tensile and compressive stresses as shown in fig. Stresses will be highest at the edges of punch and die and the materiel will start cracking there. The various steps in the rupture or fracture of the material can be written as: stressing the material beyond its elastic limit, plastic deformation, reduction in area, fracturing starts in the reduced area and becomes complete. if the clearance between punch and die is correct, the cracks starting from the punch and die edges will meet and the rupture is complete as shown in fig. If the clearance is too large or too small, the cracks do not meet and a ragged edge results due to the material being dragged and torn through the die.

DESIGN Clearance:

As is clear in the previous article, the die opening must be sufficiently larger than the punch to permit a clean fracture of the metal. This difference in dimensions between the mating members of a die set is called ‘clearance’. The clearance is applied in the following manner:-

(i) When the hole has to be held to size, i.e., the hole in the sheet metal is to be accurate(punching operation),and slug is to be discarded, the punch is made to the size of hole and the die opening size is obtained by adding clearance to the punch size.

(ii) In blanking operation, where the slug or blank is the desired part and has to be held to size, the die opening size equals the blank size and the punch size is obtained by subtracting the clearance from the die-opening size.

It is the amount of clearance per side of the die opening. The clearance is a function of the kind, thickness and temper of the work materiel, harder materials requiring larger clearance than soft materials, the exception being aluminium. The usual clearance per side if the die, for various metals are given below in terms of the stock thickness, t: For brass and soft steel, c = 5% of t For medium steel, c = 6% of t For hard steel, c = 7% of t For aluminium, c = 10% of tThe total clearance between punch and die size will be twice these fig. these clearance are blanking and piecing operations.

Minimum diameter of the piercing:

To punch a hole the compressive punch should be at least equal to the force necessary to fracture the material. The hole which will be punched under the condition will be smallest. If τ is the shear strength of the work material σ is the compressive strength, d is the smallest hole diameter to be pierced and t is the stock thickness, then smallest hole diameter to be pierced and t is the stock thickness then

Piercing pressure = Πτdt

Strength of pressure = σΠ/4

τΠdt = Π/4d²σ

d = 4τt/σ

It is assumed that σ = 2τthen

d = 2t

The minimum diameter of a hole can be punched is twice the stock thickness. In the actual practice smaller holes than this are précised successfully, showing to what extent the punch may be loaded without failure.

Cutting forces and force by our foot transmitting to shank:- In cutting forces as the punch in its downward movement enters the material it need not penetrate the thickness of the stock in the order to affect complete rapture of the part. The distance which the punch enters into the work material to cause rapture to take place is called penetration and is usually given as the percentage of the stock thickness.

The percent penetration depends upon the material is cut and also stock thickness. When a hard and strong material is being cut to very little penetration of the punch is necessary to cause fracture. With softer material, the penetration will be greater. For example, for soft aluminum,

it is 60% of t for 0.15%carbon steel is annealed; it is 38%of t. The percentage penetration depends upon the stock thickness, being smaller for thicker sheet and greater for thinner sheet.

The maximum force F is Newton needed to cut a martial is equal to the area to be shared times the shearing strength τ is N/mm²for the material. For a circular blank of the diameter D mm and of thickness t, mm the cutting force will be given as

Formula: F1 = pi* t * τ Newtons (for piercing)

Where τ is shearing stress = 60N/mm2. P is perimeter of steet to be pierced or blanked. t is thickness of sheet = 0.5 mm

F1 = 3.14x 10x0.560 =942 N F2 = pi×t× τ Newtons = 3.14 x 20x0.5x60

= 1884 N F = F1 + F2

= 942 + 1884 = 2826 N

Force we can apply by our foot is normally 400 N. By our lever we can increase effort by 5 times.As load = effort × (50/10) So load applied upward = 2000NNow this force is sent upward and here we have one more lever of effort length 20cm and load length 5 cmWe will fet force at punch =2000×4= 8000N So because of our lever mechanism we will get a increased effort of 8000N.Hence we can easily cut our material to make washer easily using this mechanism.

BOLSTER PLATE:It have dimensions (200×200×12) mm. The sides are to be machined on milling Machine and the surface on surface grinder. After that two holes of dia ¢ 22.0 mm and ¢ 12.0 mm are drilled throughout on vertical drilling machine. Then hole size of ¢ 6.8 mm is made and tapped with m8 tap.

Die Block: -It is taken of dimensions (150×150×15) mm. The sides are to be machined on milling m/c and the surface on surface grinder. Two holes of ¢ 20.0 mm and ¢ 10.0 mm are drilled throughout on vertical drilling machine. Drilling and Roaming is done to make hole size of ¢ 6.8 mm (4 No.s) and tapping is done with m8 tap set

Stripper plate: - Stripper plate has dimensions (150×150×10). A plate of (150×40×4) mm is made on vertical milling machine. Two holes of ¢ 20.0 mm and ¢ 10.0 mm are made on vertical drilling machine. Drilling and Reaming is done to make hole size of ¢ 6.8 mm (4 No.s).

Punch holding plate: - It will have dimensions of (200×200×15.5) mm. 4 holes of ¢ 14.0 mm are drilled throughout on vertical drilling machine. 12 holes are drilled of ¢ 5.0 mm and tapped with m6 tap.

Top plate :- Top plate will have dimensions (200×200×20.0) mm. 4 hole of ¢ 8.5 mm are drilled throughout m20 square threads are made in the centre for the screw movement.

Piercing Punch: - The material for the piercing punch has length 51mm and ¢ 40.2 mm. We will Face 0.5 mm from both sides. Turn a length of 50 mm to make dia 40 mm. Turn the rod up to a length of 40 mm length and make ¢ 10.0 mm. then drill 4 hole of ¢ 5.0 mm and tapping is done with m6 tap.

Blanking Punch: -We will take a rod of length 51 mm and ¢ 55.2 mm. face 0.5 mm from both sides. Turn the rod up to length 55.0 mm to make ¢ 50.0 mm. Turn up to a length of 45 mm and make ¢ 20.0. Turn up to a length of 5.0 mm to make ¢ 10.0 mm. Drill 4 hole of ¢ 5.0 mm and tapping is done with m6 tap.

Lever : -We will take a 4*4 bar of length 700 mm. towards the effort we will take 600 mm . whileat the bar going to punch we will take lenth 100mm with respect to fulcrum. Fulcurum will be at 600mm from the rope drive coming from pulley.

RAW MATERIAL ESTIMATION COST

Density of mild steel=7861 kg/m3 Cost of mild steel=Rs. 40/kgMass= volume ×density

( 1 ) Bolster plate:- Total volume =L×B×H = 202×202×21= 856884 mm³ =0.857×10-4 m3

Mass of bolster plate m = 0.857×7861×10-4

=6.74 kg

Cost of Bolster Plate = 6.74 X 40 = Rs. 270 ( 2 ) Die Block:-

Total volume V =L×B×H =152×152×16 =369664 mm3 =3.7×10-4 m2

Mass of die block m =V×S =3.7×10-4 ×7861

=2.91kgCost of Die Block = 2.91 X 40 = Rs. 117

( 3 )Stripper plate:- Total volume V=L×B×H =152×152×11 =254144mm3

= 2.54 X 10-4 m3

Mass of stripper plate:-

m=V×S=2.54×10-4 ×7861=2.0 kg

Cost of Stripper Plate = 2 X 40 = Rs. 80

(4) Punch holding plate:-

Total volume V= L×B×H =202×202×21 =856884mm3 = 8.57×10-4 m3

Mass=V×S =8.57×10-4 ×7861

=6.74 kg

Cost of Punch Holding Plate = 6.74 X 40 = Rs. 269.6

(5) Top plate:-

Total volume V= L×B×H =202×202×21 =856884 mm3 =8.57×10-4 m3

Mass=V×S =8.57×10-4 ×7861

=6.74kg

Cost of Punch Holding Plate = 6.74 X 40 = Rs. 269.6

(6) Guide post:-

Total volume V= Π /4 ×d2 ×l = Π /4 ×142 ×232 =35695.52mm3 = 3.57×10-5 m3

Mass=V×S =3.57×10-5 ×7861

=0.28kg

Cost of Guide Post = 0.28 X 40 = Rs. 12

Cost of 4 Guide Posts = 12 X 4 = Rs. 48

(7) Blanking punch:-

Volume of rod V = Π /4 ×d2 ×l = Π /4 ×522 ×55 = 116745.2mm3 = 1.2×10-4 m3

Mass = V×S = 1.2×10-5 ×7861 = 0.94kg

Cost of Blanking Punch = 0.94 X 40 = Rs. 38

(8) Piercing punch:-

Volume of rod V = Π /4 ×d2 ×l = Π /4 ×422 ×52 = 72006.48mm3 = 7.2×10-5 m3

Mass = V×S = 7.2×10-5 ×7861 = 0.6kg

Cost of Piercing Punch = 0.6 X 40 = Rs. 24

(9) Screw:-

Volume of rod V = Π /4 ×d2 ×l = Π /4 ×322 ×150 = 120576mm3 = 1.20×10-4 m3

Mass = V×S = 1.20×10-4 ×7861 = 0.948kgCost of Screw = 0.948 X 40 = Rs. 3810) Aluminium Sheet:

Total volume V = L×B×H = 1220×40×0.8 = 39040 mm3 = 3.9×10-5 m3

Mass = V×S = 3.9×10-5 ×2700 = 0.105kg

Cost of Aluminum Plate = 0.105 X 40 = Rs. 16

11)lever1:

Total volume = L×B×H =600×30×30 =510000mm3 = 5.1×10-4 m2

Mass = V×S = 5.1 ×10-4 × 7861

= 4 kgCost of plate = 4× 40 = Rs.160

12) Lever2:- Total volume = L×B×H =250×30×30 =150000mm3 = 1.5×10-4 m2

Mass = V×S = 1.5 ×10-4 ×7681

=1.1kgCost of pulley = 1.1 × 40

= Rs.44

14) Foot Platform:-

Total volume = 250×150×20 =750000mm2

= 7.5×10-4 m2

Mass = 7.5×10-4×7681= 5.7 kg

Cost = 5.7×40 = Rs. 228

15) Table:- Total volume = 650×300×100 + 4×2×2×500 = 19500000 + 8000

= 19508000mm2

Mass = 19.5 kg Cost = 19.5*40

=780 Total estimated material cost =Rs. 2382

REFERENCES

BOOKS:

Production technology by P.C. Sharma

Production technology by O.P.Khanna

Production technology by B.S.Raghuwanshi

Workshop technology by S.k.Garg

WEB:

www. google.com

www.encyclopedia.com