final project

1. PROJECT REPORT ON A PROJECT REPORT ON COMMON BENDING TOOL DESIGN FOR TWO SHEET METAL COMPONENTS(LEFT&RIGHT) GANDHI INSTITUTE FOR TECHNOLOGY, BHUBANESWAR PREPARED BY – GAURAV KUMAR SINGH KISHAN KUMAR NAIK JAGANNATH SAHU DEEPAK KU. DALBEHERA GUIDED BY- PROF.RADHAKRISHNA SAHU PROJECT HEAD- PROF.KHITISH KUMAR DASH

2. CONTENT: HISTROY INTRODUCTION TYPES OF PRESS TOOL MAJOR OPERATION BY COMPOUND TOOL THEORY DEFINITION OF STRIP LAY OUT TYPES OF STRIP LAY OUT STRIP ARRANGEMENT FACTORS DEPEND UPEN STRIP ARRANGEMENT CALCULATION DIFFERENT PARAMETERS DIE DESIGN REFERENCE

3. HISTROY:- Historically, metal was shaped by hand using a hammer. Later, larger hammers were constructed to press more metal at once, or to press thicker materials. Often a smith would employ a helper or apprentice to swing the sledgehammer while the smith concentrated on positioning the work piece. Adding windmill or steam power yielded still larger hammers such as steam hammers. Most modern machine presses use a combination of electric motors and hydraulics to achieve the necessary pressure. Along with the evolution of presses came the evolution of the dies used within them.

4. INTRODUCTION PRESS TOOL: A machine press, commonly shortened to press, is a machine tool that changes the shape of a work piece. Press tools are commonly used in hydraulic and mechanical presses to produce components at a high productivity rate. Generally press tools are categorized by the types of operation performed using the tool, such as blanking,piercing, bending, forming, forging, trimming etc. The press tool will also be specified as blanking tool, piercing tool, bending tool etc.

5. TYPES OF PRESS TOOL Blanking tool Piercing Tool Cut off tool Parting off tool Trimming tool Shaving tool Bending tool Forming tool Drawing tool Progressive tool Compound tool

6. Blanking tool When a component is produced with one single punch and die where the entire outer profile is cut in single stoke is called Blanking. Blanking is the operation of cutting flat shapes from sheet metal. The hole and metal remained after blanking operation is discarded as a waste. Size of blank or product is the size of the die & clearance is given on punch. It is a metal cutting operation. It is fast process and generally used for medium and mass production volumes. It is cheapest process in manufacturing. Piercing Tool Piercing involves cutting of clean holes with resulting scrape slug. The operation is often called piercing, In general the term piercing is used to describe die cut holes regardless of size and shape. Piecing is performed in a press with the die. The piercing tool is used to pierce the holes as secondary tool such as after bending of component etc. Cut off tool Cut off operations are those in which a strip of suitable width is cut to lengthen single. Cut-off tools can produce many parts. The required length of strip can be cut off for bending and forming operations using this tool.

7. Parting off tool Parting off is an operation that involves two cut off operations to produce blank from the strip. During parting some scrape is produced. Therefore parting is the next best method for cutting blanks. It is used when blanks will not rest perfectly. It is similar to cut off operation except the cut is in double line. This is done for components with two straight surfaces and two profile surfaces. Trimming tool When cups and shells are drawn from flat sheet metal the edge is left wavy and irregular, due to uneven flow of metal. This irregular edge is trimmed in a trimming die. Shown is flanged shell, as well as the trimmed ring removed from around the edge. While a small amount of Material is removed from the side of a component in trimming tool. Shaving tool Shaving removes a small amount of material around the edges of a previously blanked stampings or piercing. A straight, smooth edge is provided and therefore shaving is frequently performed on instrument parts, watch and clock parts and the like. Shaving is accomplished in shaving tools especially designed for the purpose.

8. Parting off tool Parting off is an operation that involves two cut off operations to produce blank from the strip. During parting some scrape is produced. Therefore parting is the next best method for cutting blanks. It is used when blanks will not rest perfectly. It is similar to cut off operation except the cut is in double line. This is done for components with two straight surfaces and two profile surfaces. Trimming tool When cups and shells are drawn from flat sheet metal the edge is left wavy and irregular, due to uneven flow of metal. This irregular edge is trimmed in a trimming die. Shown is flanged shell, as well as the trimmed ring removed from around the edge. While a small amount of Material is removed from the side of a component in trimming tool. Shaving tool Shaving removes a small amount of material around the edges of a previously blanked stampings or piercing. A straight, smooth edge is provided and therefore shaving is frequently performed on instrument parts, watch and clock parts and the like. Shaving is accomplished in shaving tools especially designed for the purpose.

9. Progressive tool Progressive tool differs from the stage tool by the following aspect, In progressive tool the final component is obtained by progressing the sheet metal or strip in many stages. In each and every stages the component will get its shape stage by stage the full shape will be obtained at the final stage. Compound tool The compound tool differs from progressive and stage tool by the arrangement of punch and die. It is a inverted tool were blanking and piercing takes place in a single stage and also blanking punch will act as piercing die. Combination tool In combination tool two or more operations will be performed simultaneously such as bending and trimming takes place in a single stage. IN combination tool two or more operations such as forming, drawing, extruding, embossing may be combined on the component with various cutting operations like blanking, piercing, broaching and cut off takes place.

10. MAJOR OPERATION BY COMPOUND TOOL BLANKING Blanking is the operation of cutting a flat shape from the sheet metal. The article punched out is called the “blank” and is the required product of the operation. The material remaining after blanking left is behind is discarded as waste. PIERCING It is a cutting operation by which various shaped holes are made in the sheet metal. Piercing is similar to blanking except that here the hole the desired product, the material cut out to form the hole being waste.

11. ClearancE :- It is defind as the difference between the punch and die in one side. Mathematically C/2=Die size-Punch size In case of blanking , Punch Size<Actual size of the component ,i.e. Punch Size =Actual size – Clearance Die size = Actual size In case of Piercing , Die size>Actual size of the component ,i.e. Die Size =Actual size + Clearance Punch size = Actual size

12. STRIP LAYOUT:- Strip layout plays an important role especially in the case of the design of the press tool. Strip decides the economic utilization of the work piece and helps in the decrease of cost of the job and reduction in the production time by increasing the number of components .

13. DEFINITION OF STRIP LAY OUT The first step in strip layout is defining the strip. This process involves naming the strip assembly and the strip part and defining the width and height of a station, the project shortcut, the number of stages, and an offset before and after the strip. You can specify a prefix for the name that is generated for parts placed inside the strip assembly. Parts include instances of the article and stamp reference parts.

14. ECONOMY FACTOR Stock material consservation is a decisive factor in means should be tried to attain this without sacrificing the piece part. Economy of any strip layout in percentage is fount out by the following formula. Economy factor(E) in %=(area of the blank *number of rows* 100)/(width of the strip*pitch) A minimum economy of 60% should be aimed . The position of the blank in the strip decides the economy factor.

15. TYPES OF STRIP LAY OUT:- Single row one pass layout:- This is the most popular way of laying out the strip.The blanks are arranged in a single row.The strip is passed through the tool only once to punch out the blanks from it. There are two possible ways of laying out this strip. - Narrow run - wide run Wide run is more desirable due to the following reasons. Shorter advance distance of the strip promotes easy feeding. More blanks could be prduced from a given length of strip compared to narrow run.Therefore a fewer number of strips are to be handled to produce a given number of blanks. Narrow run is used when the grain direction of the piece part has importance.

16. Double row lay out:- Higher economy can be attained by positioning the blanks in double rows. Gang dies:- A gang die consists of two or more similar sets of tool members so as to produce two or more number of components during a single stroke of the press ram. A gang die eliminates the cumbersome process of double pass. the higher tool cost will be off set by higher rate of production.Gang dies are not recommended for very complex work . Angular layout :- Some piece parts require to be laid out in an angular position to make the lay out more economical.

17. WHAT IS STRIP LAYOUT ARRANGEMENT? Strip layout is important to have economy of press tool operation. Scrap strip layout gives an idea on the positioning of various punches, stops and pilots. It ensures the ideal location of blanks in the stock strip . Several trial layouts have to be made to confirm the maximum percentage of utilization of stock strip. The goal should be to have at least 75% utilization . Strip-layout design is an important step in the planning stage of sheet metal work on progressive die. It is an experience-driven activity and the quality of strip-layout is highly dependent on the knowledge and skill of die designers

18. STRIP ARRANGEMENT:-

19. Press tool design types may be categorized by layout as well as by motif or style of pattern.The term layout   refers to the arrangement of motifs in the framework of the design plane . Unlike a painting or drawing, which is designed in relation to its boundaries or edges, the elements in a textile design are designed in relation only to each other. There are no  boundaries, when the pattern is printed it will continue over yards and yards of cloth. For a textile design to be reproduced on fabric, it must eventually be developed into one standard unit containing a specific arrangement of the desired motifs . This one unit,called a repeat, will be repeated across the width and length of the fabric in a continuous manner.

20. Factors depend upon strip layout arrangement:- Maximum material utilization in obtained. The choice of an efficient strip-layout is an important step during die design, because as only the optimum layout can reduce wastage of the strip material. Reduce the overall cost of production. Increases number of production of products. It also reduces company's production cost. It also saves time of production.

21. CALCULATION:- For the strip layout and design, We have to consider the following parameters. i.e , Net weight of the component Gross weight of the component Metal loss % metal loss Cutting force Press capacity Press Tonnage Die cavity

22. Basic die components 1 -shank 2 -shank holder 3 -backing plate 4 -punch holder 5 -punch 6 -guide post bushing 7 -guide post 8 -stripper 9 -guide rail 10-die block 11-die shoe

23. PART DETAILS OF COMPOUND TOOL

24. DIE DESIGN:- Overall dimensions of the die block will be determined by the minimum die wall thickness required for strength and by the space needed for screws and dowels and for mounting the stripper plate . wall thickness requirements for strength depend upon the thickness of the stock to be cut. Sharp corners in the contour may lead to cracking in heat treatment and so require greater wall thickness at such points . Only two dowels are provided in each block or element that requires accurate and permanent positioning. these should be spaced as far apart as possible for maximum locating effect, usually near diagonally opposite corners.

25. Screws and dowels are preferably located about 1.5 times their diameters from the outer edges or blanking contour. For very thin materials, 12.7 is sufficient but , except for temporary tools , finished thickness is seldom less than 22mm,which allows for blind screw holes Stock thickness(mm) Die thickness(sq. mm)per ton Stock thickness(mm) Die thickness(sq. mm)per ton 2.5 0.8 15.2 3.8 5.1 1.5 17.8 4.19 7.6 2.2 20.3 4.6 10.2 2.8 22.9 4.8 12.7 3.3 25.4 5.1

26. Die thickness also calculated according to the blank required. Die block thickness should be a minimum of 19.1mm for a perimeter between 76.2mm to 101.6mm. For longer perimeters, die block thickness should be 31.75mm. Die blocks are seldom thinner than 22.2mm finished thickness to allow for grinding and blind screw holes. If the perimeter of the blank is approximately 177.8mm , a die block thickness of 38.1 is specified of 6.4 mm grinding allowance.

27. Margin:- There should be a minimum of 32mm margin around the opening of the die block On die blocks up to a78mm square use a minimum up two M10 cap screw and two 10mm dowels For blanking heavy stock , use cap screws M14 and dowels 14mm. Die must not If special alloy steels are used then die thickness can be decreased. The critical distance A , between the cutting edge and the die border must be 1.5 to 2 times the die thickness for smaller dies. But for larger dies it may be 2 to three times. be thinner than 7.6mm

28. Clearance:- Clearance is generally taken as 10% of the strip thickness. Such as if the thickness is 1.64,then clearance should be 1.64×10=0.16 per each side. If the blank is to be the size of the die then clearance is given on the punch side . PUNCH DIMENSIONING The determination of punch dimension has been generally based on practical experience. For piercing t he dia of punch can be calculated from the following formula; 4St÷sd=1

29. Where s=unit compressive stress on the punch S=unit shear stress on the stock T=stock thickness D=dia. of punch holes Diameters of the most hole are greater than the stock thickness, but a value of ratio d:t of 1:1 is recommended The maximum allowable length of the punch can be calculated from the following formula L=(πd÷8 )×(E÷S)×(d^0.5÷t) Where E= modulus of elasticity

30. ADVANTAGES:- SMALL WEIGHT OF FABRICATED PARTS. HIGH PRODUCTIVITY OF LABOUR. HIGH VOLUME, LOW-COST PRODUCTION. PREDICTABLE STRENGTH CHARACTARISTICS. UNIFORMITY OF PARTS. LOW COST MATERIAL. LESS LABOUR-CONSUMING. LESS WASTE PRODUCT WILL OCCURS.

31. APPLICATION:- IT IS USED IN AEROSPACE INDUSTRIES, HOUSE HOLD EQUIPMENTS, AUTOMOBILE PARTS,SHIP PARTS,ELECTRONIC APPLIANCES. THE BEST EXAMPLES ARE DAILY USED SAVING BLADE,DRAWING CLIPS,COLDRINK BOTTLE CAP & CAP OPENER,CANE CLIP, ETC.

32. Metal Cutting And Tool Design By B.J.RANGANATH. Mechanical Engineering  Design By JOSEPH SHIGLEY & CHARLES MISCHKE. Engineering Design By GEORGE DIETER AND LINDA SCHMIDT. Fundamentals Of Tool Design By  David Spitler, Jeff Lantrip, John Nee and David A Smith. REFERENCES:-

33. Thank you