PROJECT REPORT

ON

LOAD BODY ANALYSIS ON TATA XENON

(PRODUCTION ENGINEERING DEPARTMENT)

IN

Tata Motors Ltd

Pune, Maharashtra

Report by-

Akash Mane

National Institute of Technology

B. Tech Mechanical Engineering

Roll number: 123205

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Acknowledgement

I would like to profusely thank Tata Motors Ltd, Pune for giving me an opportunity to undergo training in their reputed company. I would also like to take this opportunity to thank all those people who have contributed to the successful completion of this training report. I would like to express my deep sense of gratitude towards my training coordinator Mr Arthur Gonsalvez (Division Manager, Production Engineering Department), who’s valuable advice and guidance was very crucial in the completion of my project. He has been a source of inspiration and has always encouraged me to learn new things and meet different people throughout the duration of my project.

I would also like to sincerely thank all the other staff members namely: Mr Narayan, Mr Prashant Pawar, Mr Amol and others for their help and support that was provided to me during the course of my internship.

I hope that I can build upon this enriching experience and knowledge that I have gained and make a valuable contribution towards this industry in the coming future.

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CONTENTS

ACKNOWLEDGEMENT

TATA GROUP PROFILE

TATA MOTORS MANUFACTURING PROCESS

PRODUCTION ENGINEERING DEPARTMENT

MISSION AND ROLE OF PE DIE CONSTITUENTS DIE MANUFACTURING PROCESS PATTERN SHOP AND MACHINE SHOP DIE ASSEMBLY AND TRY OUT

SHEET METAL FORMING

TYPES OF PRESSES MATERIALS USED AND THEIR PROPERTIES FORMING LIMIT DIAGRAM TYPES OF DIES ASSESSMENT OF A SHEET METAL PANEL DEFECTS, CAUSES AND WAYS TO REDUCE THEM

XENON LOAD BODY FRONT DOOR

MANUFACTURING PROCESS MEASUREMENTS AND READINGS DEFECTS AND WAYS TO REDUCE THEM

CONCLUSION BIBLIOGRAPHY

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TATA GROUP PROFILE

Tata Motors is one of the 32 publicly listed enterprises under the Tata Group, India’s largest business corporation. Tata Group was established in 1868 by Jamsetji Tata and is headquartered in India. It comprises over 100 operating companies, with operations in more than 100 countries across six continents, exporting products and services to over 150 countries. The revenue of Tata companies, taken together, was $103.27 billion (around Rs.6,24,757 crore) in 2013-14, with 67.2 percent of this coming from businesses outside India.

The Tata group’s core purpose is to improve the quality of life of the communities it serves globally, through long-term stakeholder value creation based on leadership with trust. There are 31 publicly-listed Tata enterprises and they have a combined market capitalisation of about $128.1 billion (as on May 28, 2015), and a shareholder base of 3.9 million. Tata companies with significant scale include Tata Steel, Tata Motors, Tata Consultancy Services, Tata Power, Tata Chemicals, Tata Global Beverages, Tata Teleservices, Titan, Tata Communications and Indian Hotels.

Good corporate citizenship is part of the Tata group’s DNA. Sixty six percent of the equity of Tata Sons, the promoter holding company, is held by philanthropic trusts, thereby returning wealth to society. As a result of this unique ownership structure and ethos of serving the community, the Tata name has been respected for more than 140 years and is trusted for its adherence to strong values and business ethics.

Each Tata company or enterprise operates independently and has its own board of directors and shareholders, to whom it is answerable. Many Tata companies have achieved global leadership in their businesses. Employing a diverse workforce in their operations, Tata companies have made significant local investments in different geographies.

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TATA MOTORS

Tata Motors Limited was founded in 1945 as a manufacturer of locomotives. It is headquartered in Mumbai, Maharashtra, India and is a subsidiary of the Tata Group. Tata Motors collaborated with Germany’s Daimler Benz in 1954 for 15 years to manufacture commercial vehicles. Since then, Tata Motors has grown vastly and produces numerous vehicles through their three main divisions – Passenger Cars, Utility Vehicles and Commercial Vehicles

Tata Motors Limited is India’s largest automobile company, with consolidated revenues of INR 2,32,834 crores (USD 38.9 billion) in 2013-14. It is the leader in commercial vehicles in each segment, and among the top in passenger vehicles with winning products in the compact, midsize car and utility vehicle segments. The Tata Motors Group’s over 60,000 employees are guided by the mission “to be passionate in anticipating and providing the best vehicles and experiences that excite our customers globally.''

The company’s head office is situated in Mumbai & the works at Pune, Jamshedpur, Luck now & Dharwad. Tata motors ltd. Plant at Pune started its production on small scale in 1965 & has gradually blossomed into sophisticated huge plant. Besides commercial vehicles, the company manufactures a wide range of engineering products such as excavators, overhead cranes, large press tools, special purpose machines (SPM) & various CNC machines GPM’s & various other products.

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MANUFACTURING PROCESS

The Passenger Car Business Unit at Tata Motors basically deals with the production of the following passenger vehicles namely: Tata Indica V2, Indica V2 Turbo, Aria, Bolt, Indigo XL, Indigo ECS etc. whereas the Commercial Vehicle Business Unit deals with the production of LCVS, MCVs and HCVs. The assembly line of the PVB unit generally consists of BIW (Body in White) line, trim lines, underbody lines, and mechanical lines. Each of these lines consists of a several numbers of stations. After the completion of the specified operations in one line, the body of the car moves to the next line. After the complete assembly, several tests are performed on the car.

The order of assembly is given below:

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PAINT TOUCH UP

SHOWER TEST

HEAD LAMP FOCUS

WHEEL ALIGNMENT

MECHANICAL LINE 1& 2

UNDERBODY 1 & 2

TRIM LINE 1 & 2

BIW LINE

PRODUCTION ENGINEERING DIVISION

The Production Engineering division is the central tool room for TATA motors, Pune and occasionally makes tooling for Jamshedpur having the distinction of being one of the biggest and most sophisticated tool rooms in the Indian Subcontinent; it is also very versatile and employs around 850 employees. Here, high level of precision technology is employed for manufacturing of press tools, Jigs and Fixtures, gauges, metal patterns and the special tooling’s required to process various parts of the automobile. This division has also developed several hydro-pneumatically automated dies and fixtures for the first directly to the sophisticated CNC machines so that the die geometry can be directly download onto the machine.

 ROLE AND OBJECTIVES OF PRODUCTION ENGINEERING

Catering to the increasing needs of tooling for Tata Motors and its ancillaries for introduction of new vehicle models.

Meeting demands of tooling for production of above models. Introduction of new technologies in design and manufacture of tooling

to meet international standards. Introducing new products designed and manufactured in PE. Exporting dies to various companies. Enhancing skill and involvement of operatives through training,

teamwork, healthy environment, self-working practices, small group activity and suggestion box scheme.

Effective servicing and maintenance of tooling supplied by PE to Auto Division and other In-House customers.

PE has these main Departments:

Sheet Metal Tool Design Central Jigs and Fixtures Design Metal pattern Design. PE Shop Floor consists of the following sections:

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Machine shop (Heavy And Light Machine Shop) Die Assembly Section(Die Assy-01, Die Assy-02) Die Try Out Section Jigs And Fixtures Assembly Pattern Shop Sheet Metal Fixtures Jig Boring And Gauge Room Process Planning & Production Control

DIE CONSTITUENTS

To cut and form a sheet metal into the required shape, dies are used. The major components of a die are

1. Upper shoe/Lower shoe: These are structures made of steel and serve as foundations for mounting die components. The upper and lower die shoes assembled together with guide pins create the die set.

2. Guide pins: Guide pins ,sometimes referred to as guide posts or pillars, function together with guide bushings to align both the upper and lower die shoes precisely

3. Heel blocks and heel plates: Heel blocks are special steel blocks that are precision-machined, screwed, doweled, and often welded to both the upper and lower die shoes. They contain components called wear plates and function to adsorb any side thrust that may be generated during the cutting and forming processes

4. Punch: Component of the die set that stamps the metal to perform the necessary cutting or non – cutting operation.

5. Blank Holder: Holds the outer rim of the sheet metal undergoing the drawing operation and controls the material flow into the die radius.

6. Pad: A pad is simply a pressure-loaded plate, either flat or contoured, that holds, controls, or strips the metal during the cutting and forming processes.

7. Retainer: Retainers hold or secure cutting or forming die components to both the upper and lower die shoes.

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MANUFACTURING PROCESS

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PE CAE

CRITICAL PARAMETER CHECKING WITH INSP. FIXTURE.

DESPATCH WITH SHOP DELIVERY NOTE

FINAL TRY OUT & Q. A. CERTIFICATION

ASSEMBLY SECTIONS WITH FEEDBACK

TRY - OUT

ASSEMBLY SECTIONS FOR TOOLMAKING WORK, HEAT TREATMENT & ASSEMBLY.

COPY MACHINING L. DIE, U. DIE & PAD

ASSEMBLY SECTIONS

DIE & DRAWING BOOKED IN DIE ASSEMBLY

PRIMARY M/CINGPRIMARY M/CING

CASTINGPRIMARY M/CING

FOR 200 SERIES ITEMS

FABRICATION

THERMOCOLE PATTERNPROD. CONTROL

PLANNING

SMTD

COMP. DRG / CAD DATA

DIE DESIGNING

Designing is the first stage of die manufacturing. SMTD department works for die design. Die designing starting in CTED after receiving the computer drawing.

PE PROCESS PLANNING & PRODUCTION CONTROL

The PE Planning looks after: Types of component and design of the tooling. Whether the design is simple/ complex enough, so that it can be processed in PE given to outside party, available machines & time required for manufacturing.

After the design, the Process Planning department goes through the process details and then prepares the process sheet. The Process Sheet has the routing of the all the individual items of an assembly, which are to be manufactured. It enlists all the operations to be done on the item in proper sequence as well as the sections where the respective operations are to done. Then the raw materials for the items are sent in the shop floor for machining. The Production Control keeps track of the items being machined in various machine shops (Turning, Milling and Grinding).

PATTERN SHOP

Pattern shop is basically divided into three departments:

1. Model Shop

2. Plastic shop

3. Thermo Cole shop

The model and the plastic shop area interrelated while the Thermo

Cole shop is independent.

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Generally, two types of models come to pattern shop:

1) Those, which can be made by hand.

2) Those, which require CNC machining. Here the CAD programs are directly

transferred to the M/C.

Previously wooden models were made. Wooden patterns are no

longer used. They are now being replaced by models with only a wooden base

supporting a mixture of resin and hardener in paste form, which is moulded to

the shape of the component according to the drawing. Plastic Patterns and

models are also made in this section.

THERMOCOL PATTERN SHOP

This section of pattern shop makes thermocol patterns of the dies designed by the Die Design dept. The drawings are carefully studied and taking into account all tolerances the thermocol model is made. This model is then off loaded to outside parties, which convert the thermocol model into a solid cast iron, die by the casting process.

Metal Patterns

Metal pattern design

This design office plays a highly specialized role in the design activities of PE. It deals with all types of mass produced castings, right from ordinary green sand-mold ones to high pressure aluminum die casting. This department designs metal patterns used in mass production of castings.

Metal Pattern Shop

This section manufactures and repairs all tooling in the foundry, while the routine maintenance is done at the foundry itself major maintenance work is done in this section.

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MACHINE SHOP

HEAVY MACHINE SHOP

HMS which is known as a heart of P.E.This section of the shop floor deals with the machining of all large work pieces that cannot be handled on other smaller machines. These jobs are mainly above 1 metric ton. This section has some of the most sophisticated machinery in Tata Engineering. HMS consists of two sections called as SCHARMANN section & CNC section.

Scharmann Section:

It consists of six NC machines & two CNC machines. Machining operation of casting starts from sacharmann section. The primary machining of the dies done through scharmann section.

CNC Section:

This shop consists of fourteen CNC machines. 3D machining of dies, ciba material (inspection fixtures) , thermo Cole, are done in CNC machine shop. The angular machining of cam also done on CNC. PE actively uses CNCs for production and manufacturing of dies, punches, patterns etc. These machines are epitomized by their high accuracy.

LIGHT MACHINE SHOP

This section handles jobs weighing less than 1 ton. This section is divided into 3 sections:

1) Milling

2) Turning

3) Grinding section

These sections deal with the manufacturing of all small parts required in all assemblies, gauges and other miscellaneous tooling. If high precision is necessary then the jobs are machined here and finished in the jig boring and gauge rooms. Otherwise, for routine jobs the entire manufacturing process is completed here.

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DIE ASSEMBLY SHOP

This occupies the largest of the P.E. shop floor and is concerned with the building of the dies as per design. Here all the sheet metal dies are assembled. Here machining done is complicated and is done on CNCs. The operators in this section are highly skilled and have excellent knowledge of drawing, as the drawings of dies are very complicated. The surface finish of the finished component directly depends on the dies. Hence, the dies are tried out several times and finished accordingly. The material is supplied by the stores along with the technical parts list accompanying the drawing set. There are two sections in this shop:

Die Assembly-01 Die Assembly-02

DIE TRYOUT

Starting with a blank which is passed through a set of dies to create a final part, a panel trial is taken. After the die is assembled, it is dispatched to Die Try Out section where it is loaded on a press and tried out i.e. a trial operation is performed. This section has presses of different capacities (650T-2000T). The sheet metal undergoes the corresponding forming operation depending on which die is loaded in the press.

The part obtained is inspected for defects like thinning, scoring, tool marks, hole-pulling, wrinkling, spring back etc. may be present in the part. After inspecting the component, bedding is done. In bedding operation, the part is painted with a red paste and is allowed to be placed between the dies.

The component is removed and the dies are inspected. Wherever there is a patch of color on corresponding areas of both the upper and lower dies, that area is marked as the ‘hard spot’. These hard spots are eliminated by grinding the surface of the die with a pneumatic grinder. This process is repeated until the clearance between the upper and lower die has proper clearences to produce consistent quality components within the specified limits i.e. until no more hard spots can be found.

Normally 3 components are made and inspected by the QA section. After their approval, the die is sent back to the assembly section feedback as per try-out is cleared. The dies are then reloaded and necessary Q loops are conducted to ensure proper achievement of quality parameters.

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SHEET METAL FORMING

Sheet metal is one of the most important semi-finished products used in the steel industry and sheet metal forming technology is therefore an important engineering discipline within the area of mechanical engineering. Sheet metals are characterized by a high ratio of surface area to thickness. Sheet metal forming is basically conversion of a flat sheet metal into a product of desired shape without defect like fracture or excessive localized thinning.

In automobiles the sheet metal is formed into the desired shape & brought into the required form to get auto body pressings like bonnet, bumpers, doors, etc. In aircraft’s sheet metal is used for making the entire fuselage wings and body. In domestic applications sheet metal is used for making many parts like washing machine body and covers, iron tops, timepiece cases, fan blades and casing, cooking utensils etc.

The products made by sheet-forming processes include a large variety of shapes and sizes, ranging from simple bends to double curvatures with shallow or deep recesses. Typical examples are metal desks, appliance bodies, aircraft panels, beverage cans, auto bodies, and kitchen utensils. In many cases while deforming the sheet metal, the component fractures at certain point. The causes of failure are parameters related to forming process.

TYPES OF PRESSES

Press machine tools are of two main types, hydraulic presses and mechanical presses. Selection of a type of machine press depends on the factors of the manufacturing process. The first consideration would be the basic type of process the press tool will be employed to perform. For example, a press for metal forging, a press for extrusion, a press for impact extrusion, or a press for sheet metal working will all have different general requirements. The next very important factor in machine press selection for a manufacturing operation is the press capacity required. Required press capacity is likely related to the size of the work stock, and type of process. Length of stroke over which the press delivers force is another primary factor when choosing a press machine tool, this also will be related to the basic type of process being employed.

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Hydraulic Press: The basic working principles of the hydraulic press are simple, and rely on differences in fluid pressure. Fluid is pumped into the cylinder below the piston, this causes the fluid pressure under the piston to increase. Simultaneously, fluid is pumped out of the top channel, causing the fluid pressure above the piston to decrease. A higher pressure of the fluid below the piston than the fluid above it causes the piston to rise. In the next step, fluid is pumped out from below the piston, causing the pressure under the piston to decrease. Simultaneously, fluid is pumped into the cylinder from the top, this increases the fluid pressure above the piston. A higher pressure of the fluid above the piston, than the fluid below it, moves the piston downward.

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Mechanical Press: Primarily, the mechanical press transforms the rotational force of a motor into a translational force vector that performs the pressing action. Therefore, the energy in a mechanical press comes from the motor. These types of presses are generally faster than hydraulic or screw presses, (actually the screw press may also be classified as a mechanical press). Unlike some presses, in a mechanical press, the application of force varies in both speed and magnitude throughout the distance of the stroke. When performing a manufacturing operation using a mechanical press, the correct range of the stroke is essential.

MATERIALS USED AND THEIR PROPERTIES

Material K (GPa) n E(GPa)Poisson’s Ratio

Uses

EDD513 0.501 0.2415 210 0.3 Skin panels and geometries requiring high stretch

D513 0.58 0.203 210 0.3 For all medium complexity geometries

DD1079 0.854 0.29 210 0.3

E34 0.854 0.29 210 0.3 All members requiring high yield strength

E38 0.76 0.183 210 0.3

BSK46 0.73 0.133 200 0.33

IFHS350 0.704 0.21 200 0.33 Suitable for skin panels and medium complexity geometries.

IFHS400 0.72 0.2-0.24 200 0.33

DP400/600 1.08 0.14 200 0.33High strength steels mostly suitable for open sections like channels and pillars

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DP500/800 1.303 0.14 200 0.33

FORMING LIMIT DIAGRAM

Formability is the ability of sheet metal to undergo shape change without failure by necking or tearing. A forming limit diagram, also known as a forming limit curve, is used in sheet metal forming for predicting forming behavior of sheet metal. The diagram attempts to provide a graphical description of material failure tests. This concept of FLD reflects the maximum principal strains that can be sustained by sheet metals prior to the start of localized necking.

As seen from the figure, the major strain is always positive (stretching), the minor strain may be positive or negative.

R is the normal anisotropy of the sheet.

Sheet metal is marked with small circles, stretched over a punch and deformation is observed in failure areas. FLD shows boundary between safe and failure zones. In production, FLD is used to predict the safety margin of the process and direct the designer to improve forming process and tryout the dies.

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TYPES OF DIES

The metal stamping die is an ideal tool that can produce large quantities of parts that are consistent in appearance, quality, and dimensional accuracy. Stamping is a cold-forming operation, which means that no heat is introduced into the die or the sheet material intentionally. However, because heat is generated from friction during the cutting and forming process, stamped parts often exit the dies very hot. The die's cutting and forming sections typically are made from special types of harden able steel called tool steel. Dies also can contain cutting and forming sections made from carbide or various other hard, wear-resistant materials.

There are many kinds of stamping dies, all of which perform two basic operations.

CUTTING DIES

Trim Die: Trimming dies cut away excess or unwanted irregular features from a part, they are usually the last operation performed.

Blank die: A dual purpose cutting operation usually performed on a larger scale, blanking is used in operations in which the slug is saved for further press working. It also is used to cut finished piece parts free from the sheet metal. The profiled sheet metal slug removed from the sheet by this process is called the blank or starting piece of sheet metal that will be cut or formed later.

Pierce die: Piercing is a metal cutting operation that produces a round or square hole in flat sheet metal or a formed part. The cutting punch that produces the hole is called the pierce punch, and the hole the punch enters is called the matrix.

Part off die: Part off operation is a cutting operation, in which shearing the sheet into two or more pieces is involved.

NON CUTTING DIES

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Draw die: Draw dies create the part shape by controlling metal flow into a cavity and over the forming punch. Draw dies utilize a special pressure-loaded plate or ring called a draw pad or blank holder to control the metal's flow into the cavity. This plate prevents the metal from wrinkling as it flows into the cavity. Increasing or decreasing the pressure exerted under the pad also controls how much metal feeds into the die.

Form die: All forming operations deform sheet material by exposing it to tension, compression, or both. Most part defects, such as splits and wrinkles, occur in forming operations. Successful sheet metal forming relies heavily on the metal's mechanical properties. The metal being formed must have the ability to stretch and compress within given limits. It also must be strong enough to satisfy the part's fit and function.

Restrike die: The restrike die operation fundamentally is a solid forming operation. The main difference is that a restrike die is used after most of the major forming already has been performed. The restrike die

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function is to finish forming features that could not be obtained in a previous operation. Restrike dies add details such as sharp radii and small embosses. They also help compensate for spring-back that occurred during the initial forming. A restrike die operation often follows a drawing or trimming operation.

Flanging die: Flanging is bending metal along a curved axis. Two basic types of flanges are tension or stretch flanges, and compression or shrink flanges. Tension flanges are susceptible to splitting & shrink flanges are susceptible to wrinkling. Flanges are created using a flanging die that wipes the metal between a punch and a lower die section. Both tension and compression occur during the flanging process.

Bending die: Bending can be defined simply as a forming operation in which the metal is deformed along a straight axis. Items such as tabs and channels are created using the bending process. Among the various bending methods are wipe bending, V bending, and rotary bending. Both compression and tension occur during bending. Compression occurs on the inside radius, while tension occurs on the outside radius.

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ASSESSMENT OF A SHEET METAL PANEL

Before a sheet metal panel is welded to the mating part, it has to be checked for various criteria so that the part fits and aligns between the two surfaces. This examination is done on a checking fixture.

Checking fixture:

Checking fixture is a scale to measure complicated parts. It is a measuring device on which the part sits as it would in the actual vehicle so as to simulate its behavior on the vehicle. For the manufacturing of a checking fixture, an assemblage of Cibatool blocks of specified dimensions are CNC machined which cuts out the required 3D shape of the fixture. The fixture is then painted and attachment of clamps, templates and gauges is done. Clamps & templates are used in the fixture to hold the component tightly because there should not be any movement of the component while measuring. Gauges are used to check the hole-size. The sheet metal part is placed on the checking fixture and adjusted using Primary Locating Points (PLPs) pins. 3mm rectangular pads are attached at specific locations on the checking fixture.

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The economy of production can be improved by using a fixture by allowing smooth operation and quick transition from part to part, reducing the requirement for skilled labor by simplifying conformity across a production run. The shape of the fixture consists of the base plate which is located horizontally. On the base plate we have to attach the vertical plates by welding process.

Matching area:

Matching area is the zone where the mating area of one sheet metal part sits matches with its corresponding neighbouring parts and has to be spot welded. These are marked in red color on the checking fixture.

Gap and Flush:

Gap and flush measurement is commonly carried out to examine fit and alignment between two surfaces. For example, the gap between car front floor and firewall .If fit and finish is out of specification it not only affects the aesthetics of the product but also the performance, efficiency and risk of failure.

The gap between the sheet metal and checking fixture for a part is measured with the help of a tapered measuring scale. When the scale is placed in between the sheet metal and the checking fixture at a certain point (A, B, C.), the number coinciding on the scale with the point marked is taken as the reading. Flushness can be measured with the help of a Vernier Caliper.

Quality Check:

The sheet metal panel is inspected for any defects which can be classified further as geometrical and aesthetical defects. The inspection is done visually or in a green room.

If the quality standards are not met then the report is sent back and further modifications are made in the die.

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DEFECTS AND WAYS TO REDUCE THEM

Wrinkling: One of the primary defects that occurs in deep drawing operations is the wrinkling of sheet metal material, generally in the wall or flange of the part. The flange of the blank undergoes radial drawing stress and tangential compressive stress during the stamping process, which sometimes results in wrinkles. Wrinkling is preventable if the deep drawing system and stamped part are designed properly.

Several factors can cause wrinkles in deep drawn parts, including: • Blank holder pressure• Die cavity depth and radius• Friction between the blank, blank holder, punch and die cavity• Clearances between the blank, blank holder, punch and die cavity• Blank shape and thickness

Burr: A burr is a rough edge or ridge left on an object, especially of a metal, by action of a tool or machine. It is usually an unwanted piece of material and is removed with a deburring tool in a process called 'deburring'. Burrs are most commonly created after machining operations, such as grinding, drilling, milling or turning. It may be present in the form of a fine wire on the edge of a freshly sharpened tool or as a raised portion of a surface; this type of burr is commonly formed when a hammer strikes a surface.

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Surface Scratches: This occurs when the die and punch do not have a smooth surface. Insufficient lubrication is also another cause of surface scratches. To reduce these scratches we smoothen the surface of the die and punch by polishing and grinding.

Thinning: Thinning is defined as the reduction in the given specified thickness of the sheet metal due to stretching. The maximum acceptable thinning percentage for sheet metal at Tata Motors is 20%. Too much of a blank holder pressure and friction may cause thinning of the walls and fracture at the flange bottom and corners.

Waviness: Waviness is defined as a curvy shape or profile which is not uniform or smooth. This issue can be resolved by increasing matching area and cushion pressure in the press.

Crack: A thin line in the surface of something that is broken but not separated into 2 pieces.

Orange Peel: A surface roughening defect encountered in forming products from metal stock that has a coarse grain size. It is due to the uneven flow or to the appearance of the overly large grains usually the result of annealing at too high a temperature.

Fracture: Too much of a blank holder pressure and friction may cause thinning of the walls and a fracture at the flange, bottom and the corners of any sheet metal.

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XENON LOAD BODY FRONT DOOR

A pickup truck is a light duty truck having an enclosed cab and an open cargo area with low sides and tailgate. Tata Xenon is a pickup truck manufactured by Tata Motors. The Xenon is powered by newly developed 2.2L common rail turbo diesel 140 PS (103 kW) engine (DICOR) [i.e. Direct injection Common Rail].

The load body front floor is attached at the inside of the rear end of the pick-up. It forms the inner side of the back door. This part is joined with the outer side by screws and also by spot welding and some places. When the load body front floor is closed, it can be used to safely store the goods and prevent it from falling out. When it is open, it facilitates the easy stocking and withdrawal of the goods.

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MANUFACTURING PROCESS:

In the try-out section, the operation sequence to manufacture the load body front floor consists of the following two steps:

Blank and Pierce: Blanking and piercing are shearing processes in which a punch and die are used to modify the sheet metal raw material. In blanking the punched out piece is used and called a blank; in piercing the punched out piece is scrap. The blank and pierce die is inserted in the press to perform this operation. In the try-out section for the manufacturing of Load body front floor, the piece of sheet metal required is cut from the stock material with the help of a laser cutting machine .The holes are made with the help of laser cutting machine. The sheet metal then moves on to the press where form and flange down operation is done. Laser cutting is done during the blank development phase. Once the laser cut profile is finalised, the blank die is cut to the finalised laser blank profile.

Form and flange down: In the forming process, the shape which is imprinted on the punch and die is stamped on the blank of sheet metal which produces the required design and shape. In the flange down process, bending of the edges of sheet metal is done to 900 along an axis. In the load body front floor, the corners of the sheet metal on three sides are bent down.

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The material used in the manufacture of load body front floor is D-513 automobile steel.

The properties of D-513 are listed below:

Strength coefficient (K) = 0.58 GPa

Work hardening coefficient (n) = 0.203

Young’s Modulus = 210 GPA

Poisson’s Ratio = 0.3

The ‘Load body front floor’ part hence obtained from the tryout dies after the forming operations has to be checked for various criteria such as geometrical and aesthetic defects. The geometrical parameters such as gap, flush, matching area are verified on a checking fixture.

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MEASUREMENTS AND READINGS

Part Details:

Part No.289670108284

Part Name Load body front floor

ERC Modification B7

PECAE revision NR-5

Released for (E1/E2/E3) Metal machining

Material Properties:

n value 0.200

r value (0/45/90 degree)1.29/1.33/1.30

Young’s Modulus 210,000.00 MPa

Yield Strength 237 MPa

UTS 344.9 MPa

Simulation Setup:

Material D-513

Thickness 1.60 mm

Master surface Upper side of initial blank

Blank size 1448 x 492

Material yield 96.4 %

Coefficient of friction 0.140

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Binder stroke Upper\Lower 30 mm\20 mm

Pad force Upper\Lower 40 T \120 T

Minimum draw tonnage 450 T

Press used:

A 500 T BB (Big Bed) press has to be used for the production of the load body front floor. Since the 500 T press is not available currently, the 1100 T tryout press is used.

Press 1100 T Tryout Press

Type of Press Hydraulic

Cushion Pressure (Upper\Lower) 40 T \ 120 T

Minimum Draw Tonnage 450 T

Tonnage used 1100 T

Thin sheets are frequently required to have good ductility and high strength. r- and n-values are often also determined via tensile tests in order to characterize forming properties; the n-value describes the work hardening – increase in stress – during plastic deformation up to uniform elongation, while the r-value describes the vertical anisotropy. The n-value is determined from the tensile stress data and strain values; for the r-value the transverse strain on the tensile specimen is measured.

n value: The strain hardening exponent (also called strain hardening index), noted as n, is a materials constant which is used in calculations for stress–strain behaviour in work hardening.

In the formula

σ = K ε n

σ represents the applied stress on the material,ε is the strain,K is the strength coefficient.

The value of the strain hardening exponent lies between 0 and 1. A value of 0 means that a material is a perfectly plastic solid, while a value of 1

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represents a 100% elastic solid. Most metals have an n value between 0.10 and 0.50.

r value: The Lankford coefficient (also called Lankford value, R-value, or plastic strain ratio) is a measure of the plastic anisotropy of a rolled sheet metal. This scalar quantity is used extensively as an indicator of the formability of recrystallized low-carbon steel sheets.

For sheet metals, the R values are usually determined for three different directions of loading in-plane (00,450,900 to the rolling direction) and the normal R-value is taken to be the average

Yield strength: It is the stress at which a specific amount of plastic deformation is produced, usually taken as 0.2 per cent of the unstressed length.

Quality requirements:

The % OK requirements are 90% for matching area, 90% for trim line and 100% for holes. 3mm rectangular pads are attached at specific locations on the checking fixture. The load body front floor rests on these pads. A tolerance of ±1 mm is given for the readings taken for gap measurement. The specified norm is 3mm. Thus if the value for gap lies in between 2 mm to 4 mm , the reading at that check point is considered as OK. For flush measurement, the specified norm is 0 mm and the tolerance is ±1 mm. Templates have a specified norm of 3mm and their tolerance is ±0.5 mm. If the readings obtained for matching area, trim line and holes, on the sheet metal are greater than or equal to the required percentage criteria, the part is considered as OK.

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Trim Table:

S.NO

CHK PTS

SPECIFIED NOM & TOLERANCE

(8/6/15) (11/6/15)

(12/6/15)

GAP FLUSH GAP

FLUSH

GAP FLUSH

1 A 3.0 ± 1.0 3.0 2.6 2.6

2 B 3.0 ± 1.0 3.0 2.5 2.5

3 C 3.0 ± 1.0 3.2 2.5 2.6

4 D 3.0 ± 1.0 2.6 2.6 2.6

5 E 3.0 ± 1.0 2.3 2.5 2.5

6 F 3.0 ± 1.0 2.4 2.6 2.6

7 G 3.0 ± 1.0 2.4 2.7 2.7

8 H 3.0 ± 1.0 2.9 2.5 2.9

9 I 3.0 ± 1.0 3.0 2.4 3.0

10 J 3.0 ± 1.0 2.6 2.4 2.9

11 K 3.0 ± 1.0 3.2 2.4 2.9

12 L 3.0 ± 1.0 3.8 2.6 3.0

13 M 3.0 ± 1.0 4.0 2.5 2.6

14 N 3.0 ± 1.0 3.9 2.7 2.7

15 O 3.0 ± 1.0 3.8 2.8 2.5

16 P 3.0 ± 1.0 4.1 3 2.7

17 Q 3.0 ± 1.0 2.6 3 3.0

18 R 3.0 ± 1.0 2.5 2.6 2.5

19 S 3.0 ± 1.0 2.2 2.4 2.2

20 T 3.0 ± 1.0 2.4 2.7 2.4

21 U 3.0 ± 1.0 2.2 2.6 2.7

22 V 3.0 ± 1.0 2.2 2.7 2.5

23 W 0.0 ± 1.0 0.8 0 0

24 X 0.0 ± 1.0 1.0 -1.5 -1

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25 Y 0.0 ± 1.0 1.4 -0.2 0

26 Z 0.0 ± 1.0 0.3 -0.2 -0.5

27 A1 0.0 ± 1.0 -1.0 -0.2 -1

28 B1 0.0 ± 1.0 -0.5 -0.5 -0.5

29 C1 0.0 ± 1.0 -0.8 -1.5 -1.5

30 D1 0.0 ± 1.0 -0.2 -0.5 -0.4

31 E1 0.0 ± 1.0 -1.0 -1.8 -1.0

32 F1 0.0 ± 1.0 0.1 -0.5 -0.2

33 G1 0.0 ± 1.0 -0.8 -2 -1.8

34 H1 0.0 ± 1.0 0.3 -0.8 -1.0

35 I1 0.0 ± 1.0 0.2 -0.5 -0.4

36 J1 0.0 ± 1.0 -0.7 -2 -1

37 K1 0.0 ± 1.0 -0.2 0 -0.5

38 L1 0.0 ± 1.0 -0.6 1.5 -1

39 M1 0.0 ± 1.0 0.1 -0.5 -0.4

40 N1 0.0 ± 1.0 1.0 -1 -1

41 O1 0.0 ± 1.0 0.1 -0.2 0

42 P1 0.0 ± 1.0 0.9 -1.5 -0.9

43 Q1 0.0 ± 1.0 0.1 0 -0.1

44 R1 0.0 ± 1.0 1.0 0 -0.2

45 S1 0.0 ± 1.0 1.0 1 -1.0

46 T1 0.0 ± 1.0 1.9 0.5 0

47 U1 3.0 ± 1.0 2.0 2.6 2.5

48 V1 3.0 ± 1.0 2.0 2.6 2.9

49 W1 3.0 ± 1.0 2.4 2.6 2.9

50 X1 3.0 ± 1.0 2.7 2.2 2.7

51 Y1 3.0 ± 1.0 2.6 2.4 2.7

52 Z1 3.0 ± 1.0 3.5 2.5 3.0

OK 49 47 50

TOTAL 52 52 52

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OK % 94% 90 % 96%

Match Table:

S.NO

CHK PTS

SPECIFIED NOM & TOLERANCE

(8/6/15) (11/6/15) (12/6/15)

GAP FLUSHGAP

FLUSH

GAP FLUSH

1 A 0 TO 1.0 0.8 0.1 0.6

2 B 0 TO 1.0 0.8 0.5 0.2

3 C 0 TO 1.0 0.6 0.1 0.2

4 D 0 TO 1.0 0.4 0.8 0.2

5 E 0 TO 1.0 0.2 0.7 0.1

6 F 0 TO 1.0 0.4 0.6 0.2

7 G 0 TO 1.0 0.4 0.3 0.1

8 H 0 TO 1.0 0.4 0.9 0.1

9 I 0 TO 1.0 0.5 1 0.2

10 J 0 TO 1.0 0.5 0.9 0.2

11 K 0 TO 1.0 0.7 0.7 0.3

12 L 0 TO 1.0 0.7 0.8 0.3

13 M 0 TO 1.0 0.3 0.5 0.2

14 N 0 TO 1.0 0.4 1 0.1

15 O 0 TO 1.0 0.4 1 0.1

16 P 0 TO 1.0 0.5 0.9 0.2

17 Q 0 TO 1.0 0.3 0.5 0.5

18 R 0 TO 1.0 0.2 0.7 0.2

19 S 0 TO 1.0 -0.4 1 0.1

20 T 0 TO 1.0 -0.5 0.5 0

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21 U 0 TO 1.0 -0.3 0.8 0

22 V 0 TO 1.0 -0.7 0.7 0

23 W 3.0 TO 4.0 3.1 3 3

24 X 3.0 TO 4.0 3.0 3.1 3

25 Y 3.0 TO 4.0 2.7 3.1 3

26 Z 3.0 TO 4.0 3.8 3.3 3

27 A1 3.0 TO 4.0 3.9 3.3 3.1

28 B1 3.0 TO 4.0 3.9 3.1 3

29 C1 3.0 TO 4.0 3.9 3.2 3

30 D1 3.0 TO 4.0 3.4 3.0 3

31 E1 3.0 TO 4.0 3.9 3.1 3

32 F1 3.0 TO 4.0 3 3 3

33 G1 3.0 TO 4.0 3.6 3.1 3

34 H1 3.0 TO 4.0 2.9 3 3

35 I1 3.0 TO 4.0 2.9 3 3

36 J1 3.0 TO 4.0 3.5 3.4 3

37 K1 3.0 TO 4.0 2.8 3 3

38 L1 3.0 TO 4.0 3.7 3.3 3

39 M1 3.0 TO 4.0 3.4 3.2 3.1

40 N1 3.0 TO 4.0 3.4 3.4 3.2

41 O1 3.0 TO 4.0 3.2 3.5 3.3

42 P1 3.0 TO 4.0 3.6 3.6 3.3

43 Q1 3.0 TO 4.0 3.9 3.5 3.4

44 R1 3.0 TO 4.0 3.5 3.2 3.1

45 S1 3.0 TO 4.0 2.9 3.0 3

46 T1 3.0 TO 4.0 2.6 2.7 2.7

47 U1 0 TO 1.0 -0.3 0.1 0

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48 V1 0 TO 1.0 -0.1 0.1 0

49 W1 0 TO 1.0 -0.3 0.1 0.1

50 X1 0 TO 1.0 0.2 0.5 0

51 Y1 0 TO 1.0 0.2 0.1 0.2

52 Z1 0 TO 1.0 0.1 0.1 0.2

TEMPLATE-1

53 A2 3.0±0.5 2.5 2.2 3.5

54 B2 3.0±0.5 2.5 2.0 3.5

55 C2 3.0±0.5 2.5 1.9 3.3

56 D2 3.0±0.5 2.3 1.4 3.2

TEMPLATE-2

57 E2 3.0±0.5 2.5 2.6 2.5

58 F2 3.0±0.5 2.7 2.7 2.6

59 G2 3.0±0.5 2.9 3.0 3.1

60 H2 3.0±0.5 3.0 3.0 3.5

TEMPLATE-3

61 I2 3.0±0.5 2.0 3.2 3.9

62 J2 3.0±0.5 2.5 3.5 3.5

TEMPLATE-4

63 K2 3.0±0.5 2.0 3.0 3.3

64 L2 3.0±0.5 1.9 3.4 3.3

OK 60 59 62

TOTAL 64 64 64

OK %94% 92

%97 %

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Holes Table:

The load body front floor consists of 6 holes in total out of which 2 of them are Primary Locating Points (PLPs). PLP ‘A’ signifies that the hole is of great importance. The diameter/size of the hole is measured with the help of a Vernier caliper whereas the position of the hole is checked with a gauge which has a ±1 mm tolerance. All dimensions are in mm.

Hole No.

Cluster Class

Specified dia. & tolerance (mm)

Check 8/6/15 11/6/15

12/6/15

1 PLP ‘A’ 19.00 ± 0.2

Size 19.1/19.1

19.1/19.1

19.1/19.1

Position

PLP OK PLP OK PLP OK

2 PLP ‘A’ 19.00 ± 0.2

Size 19.1/19.3

19.1/19.2

19.1/19.2

Position

PLP OK PLP OK PLP OK

3 20.00 + 0.5

Size 20.2/20.3

20.1/20.4

20.3/20.9

Position

OK OK NOT OK

4 12.00 + 0.5

Size 12.4/12.3

12.8/13.4

12.3/12.2

Position

OK NOT OK

OK

5 12.00 + 0.5

Size 12.5/12.8

13.0/12.9

12.3/12.4

Position

NOT OK NOT OK

OK

6 20.00 + 0.5

Size 20.4/20.7

20.5/20.1

20.7/20.1

Position

NOT OK OK NOT OK

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OK 6 6 6

TOTAL 6 6 6

% OK 100% 100 % 100%

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DEFECTS OBSERVED, THEIR CAUSES AND WAYS TO REDUCE THEM

Scoring marks & shock lines : The marring or scratching of any formed part by metal pickup on the punch or die results in scoring marks on the flange.

`Ways to reduce scoring marks and shock lines-

Futura Nano Coating : Ideal for applications where the tools are subject to a high thermal load, Futura Nano titanium aluminum nitride tool coatings feature a Nano layered structure engineered to provide an optimum balance between hardness and internal stress, which helps to reduce the propagation of cracks and delay the onset of failure. These tool coatings also have improved sliding properties.The coatings offer improved performance through higher speeds and feeds, while eliminating the use of coolants. Titanium aluminum nitride tool coatings are ideal for application on abrasive and difficult to machine materials such as cast iron and heat treated steel and stainless steel.

Key specifications of Futura Nano: Thickness: 4 µm Micro hardness: 3300hv Thermal stability up to 900ºC Coefficient friction vs. steel: 0.3 - 0.35

Physical Vapor Deposition: PVD describes a variety of vacuum deposition methods used to deposit thin films by the condensation of a vaporized form of the desired film material onto various work piece surfaces.

Nitriding: Nitriding is a heat treating process that diffuses nitrogen into the surface of a metal to create a case-hardened surface. These processes are most commonly used on low-carbon, low-alloy steels.

Scoring can also be reduced by grinding, polishing and stoning on the inner surface of the die so that these marks are not produced on the upcoming sheet metal.

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Galling: Galling is a form of wear caused by adhesion between sliding surfaces. When a material galls, some of it is pulled with the contacting surface, especially if there is a large amount of force compressing the surfaces together.

Causes: Galling is caused by a combination of friction and adhesion between surfaces. Galling is most commonly found in metal surfaces that are in sliding contact with each other. It is especially common where there is inadequate lubrication between the surfaces. However, certain metals will generally be more prone to galling, due to the atomic structure of their crystals

Ways to reduce galling: Galling occurs in forming of stainless steel due to lubricant film breakdown leading to scoring and bad surface quality. By hardening the sheet metal and by providing adequate lubrication between the surfaces, we can prevent galling.

Waviness and Thinning:

Waviness is defined as a curvy shape or profile which is not uniform or smooth. Thinning is defined as the reduction in the given specified thickness of the sheet metal due to stretching. The maximum acceptable thinning percentage for sheet metal at Tata Motors is 20%.

Causes and ways to reduce:

Waviness can be reduced by increasing matching area and cushion pressure in the press.

Too much of a blank holder pressure and friction may cause thinning of the walls and fracture at the flange bottom and corners.

Tool marks:

These are caused if there is a rough contact between some surface of the die and the sheet metal. This can be reduced by performing operations such as grinding, polishing and stoning.

Deformations around all depressions: 41

An even surface is not obtained on the area surrounding embosses on the load body front floor. The surface obtained has an uneven profile and the gap can be measured by using a filler gauge. To reduce this, the contact area has to be increased.

Burr:

A burr is a rough edge or ridge left on an object, especially of a metal, by action of a tool or machine. It is usually an unwanted piece of material and is removed with a deburring tool in a process called 'deburring'. Burrs are most commonly created after machining operations, such as grinding, drilling, milling or turning. It may be present in the form of a fine wire on the edge of a freshly sharpened tool or as a raised portion of a surface; this type of burr is commonly formed when a hammer strikes a surface.

INFERENCE

Parameter Required ValueObserved Value

Matching Area 90% 97%

Trim 90% 96%

Holes 100% 100%

Thinning 20% within limits

The required quality parameters i.e. matching area, trim and holes percentage were within the required limits.

Thinning of the panel was less than 20%. Other defects like cracking, tool-marks and wrinkles were not present in

the part.

CONCLUSION42

The primary objective of this project was for the xenon load front floor part to meet all the quality assurance requirements. This report provides a summary of operations taking place in the production engineering division and in particular the automotive body die-tryout section. During my project, I learnt about the role of production engineering division & basic processes involved in the manufacturing of dies, die constituents, different types of sheet metal dies & presses and processes involved in the assembly of parts in a car.

The report provides information on various types of automobile sheet metal used, their properties and the steps of forming operations performed on a blank of sheet metal. Regarding the assessment of sheet metal, I was able to identify defects, understand their causes and remedies and also learn about methods used to analyze the part with the help of checking fixture, gap and flush measurement etc. One can also understand in brief on where the load body front floor fits and what its uses are in Tata Xenon. Once the load body front floor is sent for quality check visually, the defects on sheet metal part can be observed. To reduce the number of defects, necessary modifications have to be done in the die set in try-out section. Once the die set is corrected, it can be sent over to another block for mass production of that sheet metal part.

BIBLIOGRAPHYReferences:

www.tatamotors.com www.peweb.com Basic information about die design and manufacturing

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