NEW SYNOPSIS

DESIGN OF SUPPORT BRACKET TACKWELDING FIXTURE
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Department of Mechanicalengineering P.E.S.C.E
ABSTRACT:
Welding Fixture:
A Welding fixture is a device for ensuring that a hole to be drilled, tapped or reamed
in a work piece will be machined in a proper co-ordinate or PCD. Thus instead of
laying out the position of a hole on each work piece with the aid of a square, straight
edge, scriber and centre punch, the operation uses a welding fixture to guide the drill
into the proper place. Basically it consists of a clamping device to hold the part in the
position under hardened steel bushings through which the drill passes during
operation. The drill is guided through bush. If the work piece is of simple
construction, the welding fixture may be clamped on the work piece. In most cases
however the work piece is held by the welding fixture and the welding fixture is
arranged so that the work piece can be quickly inserted and quickly removed after
machining operation is performed. Welding is usually used for mass production jobs
or precision jobs.
 The aim of the project is to design a welding fixture for drilling machine to
perform drilling operation accurately for yoke. While making holes on the yoke
lot of problems encountered such as inaccuracy, misalignment etc. These
problems cause rejection of finished jobs productivity losses more time
consumption etc.
In this project an attempt has made to design a drill welding fixture and use the
same during the holes on work pieces, which eliminates the problems faced during
conventional drilling. This procedure helps in increasing the production rate,
accuracy, perfect alignment, reducing operators fatigue etc. In this procedure a drill
welding fixture will guide the drill bit to the correct position on the workpiece. With
implementation of SOLID EDGE, the modeling of each component of a welding
fixture is designed.

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THE PROJECTWAS CARRIED OUT IN 4 PHASES
DESIGN OF FIXTURE
The fixture design was carried out in a systematic manner, with the inputs given by AAL.
Based on the date given by AAL, the design was conceptualized using CAD. Here an
interactive process was followed to come up with the suitable design according to the
specification provided by AAL.
CONVERTING OF 2-D MODEL
Based upon the findings obtained in the design process, we have converted the 2D model to
3D model using the modelling software SOLID EDGE V19. This helps in the fabrication
purpose of the design.
SELECTION OF MATERIALS
Materials selection is a step in the process of designing any physical object. In the context of
product design, the main goal of material selection is to minimize cost while meeting product
performance goals. Systematic selection of the best material for a given application begins
with properties and cost of candidate materials. For example, a thermal blanket must have
poor thermal conductivity in order to minimize heat transfer for a given temperature
difference or a load bearing member should have resistance to deformation. The materials
which are selected for this setup are Mild steel, EN8, EN24, EN353
COST ESTIMATION
In this stage the cost of the design is to be optimized. Based on the results of the analysis and
modification, a suitable material was chosen which would meet the industrial standards

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AXLE
An axle is a central shaft for a rotating wheel or gear. Axles are an integral component of
most practical wheeled vehicles. In a live-axle suspension system, the axles serve to transmit
driving torque to the wheel, as well as to maintain the position of the wheels relative to each
other and to the vehicle body. The axles in this system must also bear the weight of the
vehicle plus any cargo. A non-driving axle, such as the front beam axle in heavy duty trucks
and some 2-wheel drive light trucks and vans, will have no shaft, and serves only as a
suspension and steering component.

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SUPPORT
BRACKET

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PRINCIPLES OF FIXTURE DESIGN
1. LOCATION
 Ensure that work is given desired constraints.
 Place the locators so that swarf will not cause misalignment.
 Make the location points adjustable if a rough casting or a
forging is being formed.
 Introduce fool proofing devices such as fouling pins, projections
etc. to prevent incorrect positioning of the work piece.
 Make all location points visible to the operator from his working
position.
 Make location progressive.
2. CLAMPING
 Position the clamps to give best resistance to cutting forces without
causing deformation of the work piece.
 If possible make the clamps integral with fixture body.
 Make all clamping and location methods easy and natural to perform.
3. CLEAFRANCE
 Allow sample clearance to allow for variations of work piece size and
operator’s hand.
Ensure that there is sample swarf clearance and clearance to enable the
work piece to be removed after machining, when burns will be present.
4. STABILITY AND RIGIDITY
 Make the fixture as rigid as required for operation.
 Provide means of positioning and bolting the equipment to machine
table.
 Provide four feet so that uneven seating will be obvious and ensure
that the forces on the equipment act within area enclosed by a line
joining points.
5. HANDLING
 Make the component as light as possible and easy to handle, and
ensures that no sharp corners are present and provide lifting points, if
it is heavy.

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6. GENERAL
 Keep the design simple in order to minimize the cost, and avoid break
down caused by over contraction.
 Utilize the standard and proprietary parts as much as possible.
7. PROVISION FOR COOLANT
 The jig or fixture most have adequate arrangement for the supply of
coolant to the cutting edge of the tool, so that the tool is cooled and at
the same time the swarf of the chips produced are washed away so
that, operator does not waste his time in adjusting the coolants flow
and cleaning the chips.
ELIMINATE FINISHING OPERATIONS
Finishing operations should never be performed for cosmetic purposes. Making a fixture look
better often can double its cost.
KEEP TOLERANCES AS LIBERAL AS POSSIBLE
The most cost effective tooling tolerance for a locator is approximately 30% to 50% of the
work piece’s tolerance. Tighter tolerances normally add extra cost to the tooling with little
benefit to the process. Where necessary ,tighter tolerances can be used, but tighter tolerances
do not necessarily result in a better fixture , only a more expensive one.

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STEPS OF FIXTURE DESIGN
Step 1: DEFINE REQUIREMETS
To initiate the fixture design process, clearly state the problem to be solved or needs to be
met. State these requirements as broadly as possible, but specifically enough to define the
scope of the design project.
The designer should ask some basic questions:
Is the new tooling required for first-time production or to improve existing productions?
If improving an existing job, is the goal greater accuracy ,faster cycle times ,or both? Is the
tooling intended for one part or an entire family of parts?
Step 2: GATHER INFORMATION
Collect all relevant data and resemble it for evaluation. The main sources of information are
the part print ,process sheets, and machine specifications. Make sure that part documents and
records are current .For example, verify that the shop print is the current revision, and the
processing information is up-to-date. Check with the design department for pending part
revisions.
An important part of the evaluation process is note taking. Complete, accurate notes allow
designers to record important information. With these notes, they should be able to fill in all
items on the “Checklist for design Considerations “.All ideas, thoughts, observations and any
other data about the Part or fixture are then available for later reference .It is always better to
have too many ideas about a particular design than too few.

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Step 3: DEVELOP OPTIONS
This phase of the fixture-design process requires the most creativity. A typical work piece
can be located and the clamped several different ways. The natural tendency is to think of
one solution, then develop and refine it while blocking out other, perhaps better solutions. A
designer should brainstorm for several good tooling alternatives ,not just choose one path
right away.
During this phase ,the designer’s goal should be adding options ,not discarding them. In the
interest of economy, alternative designs should be developed only far enough to make sure
they are feasible and to do a cost estimate.
Step 4: CHOOSE THE BEST OPTION
The fourth phase of the tool-design process is a cost/benefit analysis of different tooling
options. Some benefits, such as greater operator comfort and safety, are difficulty to express
in dollars but are still important. Other factors, such as tooling durability, are difficult to
estimate.
To evaluate the cost of any work holding alternative, first estimate the initial cost of the
fixture .To make this estimate, draw an accurate sketch of the fixture. Number and list each
part and component of the fixture. Number and list each part and component of the fixture
individually.
First list the cost of each component, them itemize the operations needed to mount, machine
and assemble that component. Once those steps are listed, estimate the time required for each
operation for each component, and then multiply by the labour rate.

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WELDING USING FIXTURE:
• Initially the fixture is located in its position on the housing.
• The next operation involves the proper placement of the TOP PAD BRACKET
followed by its clamping.
• Once the clamping is done, tack welding is done.
• After tack welding fixture is unclamped and the bracket is fully welded.

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SELECTIONOF MATERIALS
SELECTION OF MATERIAL BASED ON THE JOB AND HEAT TREATMENT
Material selection is a step in the process of designing any physical object. In the
context of product design, the main goal of material selection is to minimize cost while
meeting product performance goals. Systematic selection of the best material for a given
application begins with properties and costs of candidate materials. For example, a thermal
blanket must have poor thermal conductivity in order to minimize heat transfer for a given
temperature difference or a load bearing member should have resistance to deformation.
The materials which are selected for this setup are Mild steel, ENS, EN24, EN353.
MILD STEEL
It is the most common form of steel often used when large amounts of steel are
needed.
Mild steel is a carbon steel typically with a maximum of 0.25% Carbon and 0.4%-
0.7% manganese, 0.1%-0.5% Silicon and some traces of other elements such as phosphorous,
it may also contain led or sulphur.
Mild steel have good strength and low to medium Carbon content and can be bent,
worked or can be welded into an endless variety of shapes for uses from vehicles to building
materials.
Though mild steel is a strong as most steels, and corrodes quickly in moist
environments, but is cheap and readily available and hence is used the most worldwide.
Different types of steel have different properties that make them useful for specific
things. Steel’s property comes from the way that it was made. Steel with more carbon will be
harder yet more brittle. Sometimes,

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Stress straindiagram for mild steel
Graph of stress as a function of strain can be constructed from data obtained in any
mechanical test where load is applied to a material, and continuous measurement of stress
and strain are made simultaneously. It is constructed for compression, tension and torsion
tests.

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EN8:
EN8 is an unalloyed carbon steel with good tensile strength. The material also requires heat
treatment for hardening of the component to avoid failure during operation.Tensile properties
may vary but are usually between 500-800 N/mm^2
Chemical Composition
Typical analysis in %
C Si Mn S P
0.40% 0.25% 0.80% 0.015% 0.015%
Application : Components of small cross section, requiring low tensile strength, as well as
heavy forging in the normalized condition for automotive and general engineering such as
axles, clutch shafts, presses and punches parts, piston rods and gear rods.
Heat treatment: The material also requires heat treatment for hardening of the component to
avoid failure during operation. The heat treatment carried out for EN8 steel is as depicted
below.
Hardening temperature Quenching medium Tempering
temperature
750-900 oil 150-200

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EN24
It is a high quality, high tensile, alloy steel. Usually supplied readily machine able. It
combines high tensile strength, shock resistance, good ductility and resistance to wear. EN24
is available from stock in round bar, flat bar and plate.
EN24 comes treated in the condition to 850/1000 N/mm^2, EN24 is a popular grade of
through hardening alloy steel due to its machinability. EN24 is used in components such as
gears, shafts, studs and bolts. EN24 can be further surface-hardened to create components
with enhanced wear resistance by induction or nitrating processing.
In addition to the above, EN24 is capable of retaining good impact values at low
temperatures, hence it is frequently specified for harsh offshore applications such as
hydraulic bolt tensioners and ship borne mechanical handling equipment. It is therefore
recommended that larger sizes are applied in the annealed (softened) condition and that
quenching and tempering is carried after initial stock removal. This should achieve better
mechanical properties towards the core.
C Si Mn Ni Cr Mo
0.40% 0.30% 0.60% 1.50% 1.20% 0.25%
EN353 Steel
En353 is a case hardened steel which is carburized with carbon percentage of up to
0.2%. It is the most widely used industrial application which produces a hard ware resistance
surface layer on low carbon and low alloy steels.
The chemical composition of the EN353 is listed below
C Si Mn Cr Mo Ni
0.10-
0.20
0.35 0.50-1.00 0.75-1.25 0.80-0.15 1.00-1.50

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2D DRAWING

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OBJECTIVE OF THE PROJECT:
1) To Save the Machining hour rate of Support pad by providing a new welding
fixture
2) To Accommodate the job better and increase the production on Welding
Machine
3) Higher utilization of available resources
SCOPE OF THE PROJECT:
The project plays very important role in an industry for increasing the productivity by
decreasing the set up time by decreasing the machine hour rate.
METHODALOGY(PROCEDURE):
1) Product lay out drawing
2) Conceptual drawing to make Fixture design
How Fixture will work?
1) Fixture will locate in Brake Flange holes on housing & it will rest on Housing
Box section
2) Fixture will be clamped to the Flange
3) Support Pad will be located in the Fixture.
4) Tack welds the Support pad to the housing.
5) De clamp the fixture
6) Inspect the component ( Tack welded Housing)
7) Repeat the same on other side.

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ADVANTAGE:
 It eliminate the marking out measuring and other setting method before
machining
 It enable identical parts which are interchangeable, this facilitates the
assembly operation
 It increases the machining accuracy because the work piece is automatically
located and the tool guided without making manual adjustment .
APPLICATION:
Support Bracket will be welded on the housing & machining will be done (Milling,
drilling & Tapping)Plummer Block will be mounted on this bracket &
it will support to Brake cam shaft to be aligned in one axis.
CONCLUSION:
The newly designed welding fixture helps to simplify the operation and reduces the
risk of the operator during loading and unloading. Therefore even unskilled workers
can operate the machine to produce accurate welding on the work piece. The
replacement of skilled workers also proves cost effective. It welds the housing with
accurate alignment and hence loss of rejections will be minimized. It also protects
the work piece surface free from scratches, damages etc.
This fixture helped in achieving more positional accuracy and precision in
welding the bracket.
 Time taken to carry out the welding process using the welding fixture
was reduced while compared to conventional method.
 The fixture allows objective of using a fixture to reduce the cycle time
and production costis achieved.
ADVANTAGES OF NEWLY DESIGNED WELDING FIXTURE FOR TOP
PAD BRACKET:
The advantages of the welding fixture are as follows:
 This kind of welding fixture uses the simple clamping mechanism.

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 EASE OF OPERATION: Thewelding fixture for mounting TOP PAD
bracketprovides a flexible design, which results in skill reduction.
 COST REDUCTION: Higher production, reduction in scrap and saving in
labour cost
Results in substantialreduction in cost of Axle housing with TOP PAD
Produced using fixtures.
This design provides the great flexibility of welding TOP PAD bracket without
marking, whereas in conventional method, welding is preceded by marking the
component.
 REPEATABILITY: It is the variation in the measurement taken by a single
person or instrument on the same item and under the same conditions.
 The design saves a lot of time, avoiding the marking process.
 The welding fixture also incorporates fool-proof mechanism, which
prevents the miss alignment time of the component.
FIT TO USE: The newly designed fixture is ready to use without much
alterations.

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Student's Signature
1.
2.
3.
4.
Mr.Rudresh Addamani
Asst professor
Department Of Mechanical Engineering
PESCE, Mandya
Signature of Guide

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