TABLE OF CONTENTS
CHAPTER NO. TITLE PAGE NO.
ABSTRACT IN TAMILABSTRACT IN ENGLISHACKNOWLEDGEMENTLIST OF
TABLESLIST OF FIGURES
1 INTRODUCTION11.1INTRODUCTION11.2 OBJECTIVE OF THE
PROJECT11.2METHODOLOGY21.4 INTRODUCTION TO BICYCLE SIDE STAND31.4.1
Bracket31.4.2 Leg rod31.4.3 Holder41.4.4 Bush41.3.5 Springs and
Washers51.3.6 Rivets, Bolts and Nuts52 LITERATURE REVIEW6
3 MATERIAL AND PROCESS93.1 BRACKET MATERIAL93.1.1 Chemical
Composition93.1.2 Mechanical properties93.1.3 Minimum Internal
diameter of bend103.1.4 Delivery condition103.2 DIE MATERIAL113.2.1
Chemical composition113.2.2 Mechanical properties113.3
MANUFACTURING PROCESS113.3.1 Sheet strip cutting133.3.2 Piercing,
Notching and Blanking133.3.3 Company identity marking133.3.4 First
forming143.3.5 Second forming143.3.6 Folding153.3.7 Acid
cleaning153.3.8 Powder coating153.3.9 Assembly164 DESIGN
CONSIDERATION AND CALCULATION174.1 DESIGN CONSIDERATION174.1.1
Marking174.1.2 Embossing174.1.3 Bending184.1.4 V- Bending184.1.5
Air bending184.1.6 Bottoming194.1.7 Wiping204.1.8 Spring
back204.1.9 Spring back compensation224.2 DESIGN CALCULATION224.2.1
Force required for Identity marking224.2.2 Force required for
embossing224.2.3 Force required for bending234.3.4 Press selection
and specification244.3.5 Tool height254.3.6 Hexagonal socket headed
screw264.3.8 Pillar set284.3.9 Bush set285 MODELLING OF TOOL295.1
INTRODUCTION295.2 COMPONENT MODEL IN SEQUENCE295.2.1 Blank
modelling295.2.2 First forming305.2.3 Second forming305.3 DIE
MODEL315.3.1 Bottom die Model315.3.2 Top die model315.3.3 Modelling
of supporting elements316 CONCLUSION356.1 Conclusion356.2 Future
work35REFERENCES36
LIST OF FIGURES
FIGURE NO TITLE PAGE NO.
1.1 Proposed methodology21.2 Bracket31.3 Leg rod41.4 Holder4 1.5
Bush42.1 3D model of forming tool developed in solid Works 200363.1
Process flow chart12 3.2 Sheet strip13 3.3 Blank13 3.4 Marking14
3.5 First forming14 3.6 Second forming15 3.7 Folding15 3.8 Powder
cleaning16 3.9 Assembly16 4.1 Air bending19 4.2 Bottoming19 4.3
Wiping20 4.4 Illustration of spring back21 4.5 Shut height of
press25 4.6 Hexagonal socket headed screw27 4.7 Die set
parameters27 5.1 3D Model of blank29 5.2 First forming30 5.3 Second
forming30 5.4 Bottom die Model32 5.5 Bottom die Model32 5.6
Location of the blank on the bottom die 33 5.6 Assembly of
supporting elements in tool set 33 5.7 Assembly of the die
set34
LIST FO TABLES
TABLE NO. TITILE PAGE NO.
3.1Chemical composition of bracket 9 3.2 Minimum Internal
diameter of bend10 3.3Chemical composition of die material11
4.1Spring back angle compensation22 4.2Press specification24 4.3Die
set parameter specification27
CHAPTER 1INTRODUCTIONINTRODUCTION This work deals with the
design analysis and process simulation of a sheet metal component
with multiple bends is a product supplied by SVL ENTERPRISES. SVL
is a medium scale Industry located in Thiruvallur. SVL is vendor of
TI cycles of India having more than 15 years the company tie up
with the TI cycles. Some of the components made in the plants are
Bicycle side stands for TI cycles Bicycle carriers for TI cycles
Channels for TI metal forming Crank case plating for Caterpillar.
Due to the unavailability of labour at sufficient levels and
increase in the production rate, adaptation of new technology is
important for growth. In this work it proposed to combine three
process in the sequence of manufacturing into a single stage
process by the application of CAE tools. This not only increases
the production rate but also reduces the cost and time of
production of the component. 1.2 OBJECTIVE OF THE PROJECT To design
the complete die set for combining three individual steps of
operation in single stage. To develop the solid model of die sets
and components by CAE tools. To simulate the process and perform
stress analysis of the component. To analyse the die to determine
the stress in the critical sections. To giving proper component
model to the industry for manufacture. METHODOLOGYThe tool design
starts from the need and problem description. Then the
understanding of the problem leads to the literature and design
criteria needed to incorporate. Based on this the design and model
of the component is generated using CAE tools. Evaluation of the
critical regions and the remedies will be done in the simulation
stages. Fig. 1.1 shows the methodology adopted in the design of
tools.
Fig.1.1 Proposed methodology 1.4 BICYCLE SIDE STANDBicycle side
stands are used to park the bicycle in an easy manner. Various
bicycle companies has different types of side stand designs. Some
of the designs are Lady bird splash, Captain DX, AXN 26, AXN 24,
Utima 24, Ultima 26 and Herculus dirt rider. These have difference
in their cut length of leg rod, bracket notch area and blank hole
position. The various component of the bicycle side stand are
Bracket Springs
Leg rod Washers
Holder Rivets
Bush Bolts & nuts
1.4.1 BRACKETBracket is a component which connects the side
stand leg rod with the bicycle frame with the help of bolt and
nuts. It is not a straight component but an angled one. This angle
helps to make easy contact between the land surfaces to the side
stand. Embossing recess helps to increase the stiffness of bend and
gives strength to the bracket. A rivet hole is provided to connect
the bracket with the leg rod through rivet connections. Fig. 1.2
shows the bracket which is to be produced using the designed
die.
Fig.1.2 Bracket1.4.2 LEG RODLeg rod shown in the Fig.1.3 is an
important and basic component in the side stand. Initially using
the wire drawing machine, the rod in the form of coil is drawn as a
uniform diameter and cut to the specified length. One end of the
rod is flattened to make the hole and another end of the rod is
boot. Boot is molded using injection molding machine. In some types
of stand a cup with a hole is welded with the rod to form boot. For
placing the washer and spring arrangements a notch impression is
generated on the rod.
Fig.1.3 Leg rod1.4.3 HOLDERHolder shown in the Fig.1.4 is used
to make the assembly of the spring with the leg rod. This is made
up of Polypropylene Co Polymer (PPCP) black plastic material in the
injection molding machine. It has good environmental impact and
good strength to withstand the spring impact.
Fig.1.4 Holder1.4.4 BUSHThe bush shown in Fig.1.5 provide
support to the holder with the bracket end. It is also made up of
PPCP black plastic material.
Fig.1.5 Bush1.3.5 SPRINGS AND WASHERSSprings are used to make
release the stand from the original position. The spring is placed
on the rod notch with the help of washer and it is also covered by
the holder. The company outsources the component from an external
supplier (Aleef Springs Marketing Agency).Washer is used to
constrain the spring in the rod through the rod notch provided. The
company make the washer in this branch itself. The sheet strips
with the proper length are cut from the coil. Using punch and die
first inside hole is pierced and then outer surface is
pierced.1.3.6 RIVETS, BOLTS AND NUTSRivet, bolts and nuts all these
are out sourced by the company from their external supplier. Rivets
are used to connect the bracket with the leg rod assembly through
pressing using hand press. Bolts and nuts are used to connect the
bracket with the bicycle frame.
CHAPTER 2LITERATURE REVIEW
Annigeri et al. (2014) discussed the design, development and
structural analysis of a forming tool for a side panel of
automobile. The design starts from the design requirements, then
force needed to achieve the forming and embossing operations were
calculated by using the standard formulae. Based on the total force
and press availability the press was selected. Using SOLIDWORKS
2013 the modelling of tool and die were generated as per the
drawings. Then ANSYS 5.4 was used to analyze the tool stress and
deformation. The model was free meshed using isoparametric SOLID92
3-D 10node tetrahedral structural solid. It was observed that the
design of forming tool is safe as the von-misses stress is well
within the compressive strength of the material for both punch and
die. The deflection of both punch and die are well within the
allowable deflection of 0.05 mm and hence it was conclude that the
design of both forming punch and die was safe. The reduction in web
thickness of punch and die by 30% did not interfere with the
allowable stress and deflection values of punch and die. This has
led to a weight reduction of 4.2 kg. Fig. 2.1 shows the 3D model of
forming tool.
Fig 2.1 3D model of forming tool developed in solid Works
2003Madake et al. (2013) reported on developed sheet-metal
component with a forming die using CAE software tools (Hyper form)
for design validation and improvement. Punch and die to form the
cup was designed and the various dimensions, blank holding force,
force required to perform the operations were calculated. HYPERFORM
is used analyze the stress. The operating condition involving the
magnitude of blank holding pressure is varied and the results
analyzed. Suitable blank holding pressure (5Ton) is recommended for
a defect-free component. The results obtained by mathematical
treatment and the results obtained through the use of software
(analytical) agree reasonably well.Sheng et al. (2007) worked on
FEM analysis and design of bulb shield progressive draw die. The
progressive tools was used to produce bulb shields include complex
deep draw operations. The component was modeled and analyzed using
FEM code DYNAFORM 5.2. An FEM simulation based analysis and design
method for the draw operations is proposed in this study. Based on
the analysis on the second draw punch radius effect on Von Mises
stress which represented the material work hardening tendency, an
improved design was suggested. The resultant progressive die has
been manufactured and is running successfully in production. With
the aid of FEM simulation, forming problems can be visually
identified. Furthermore, utilization of these simulations to
predict forming and cosmetic problems at the part design phase
offers significant advantages.Chan et al. (2004) reported on Finite
element analysis of spring-back of V-bending sheet metal forming
processes. This paper presents a study of spring-back in the
V-bending metal forming process with one clamped end and one free
end. Different die punch parameters such as punch radius, punch
angle and die-lip radius are varied to study their effect on
spring-back. Also, the effect of the punch displacement on
spring-back is investigated. The H-convergence test is done to
justify the number of elements used. Patran is used to model the
nodes of the sheet metal and rigid surfaces of the die, pad and
punch. Abaqus/Standard is used to simulate the punching process.
The results are analyzed using Abaqus/CAE. The analysis shows that
spring-back angle of the valley region decreases with increment of
punch radius and punch angle. Therefore, there is an optimum punch
radius to achieve minimum spring-back
Mastanamma et al. (2012) reported on Design and Analysis of
Progressive Tool for a sheet metal component with multiple holes.
The progressive tool with its supplementary elements were designed
in Pro-E. Using ANSYS, tool was analyses ny applying suitable
boundary conditions. The results were compared with the theoretical
calculations and verified.
So for from the literature all the design has been started from
the design requirement and need. For the sheet metal bending spring
back is the important criteria to make the bend to be accurate.
This literature gives the methodology of the project and importance
of application of CAE tools in design and analysis.31
CHAPTER 3MATERIAL AND PROCESS3.1 BRACKET MATERIAL The bracket
material is specified by the TI cycle component drawings. According
to that IS 1079: 2069 sheet material is selected. 3.1.1 Chemical
CompositionTable 3.1 gives the chemical composition of the material
of the bracket. From this HR3 grade is selected based on the
drawing instructions.Table 3.1 Chemical composition of bracket
materialS.No Quality Constituent
DesignationOld designationNameCMnPSMicro-alloy
IHR0NewOrdinary0.251.700.050.045-
iiHR1OCommercial0.150.600.050.035-
iiiHR2DDrawing0.100.450.0400.035-
ivHR3DDDeep Drawing0.080.400.0350.030-
vHR4EDDExtra Deep Drawing0.080.350.0300.030-
ViHR5NewMicro-Alloyed dual Phase0.161.60.0200.0200.2
3.1.2 Mechanical propertiesDensity of the material is 7850 kg /
mm3 Tensile strength = 300 N / mm2 Percentage of elongation = 23%
3.1.3 Minimum Internal diameter of bendThe minimum bend radius is
the radius below which a component should not be bent. Table 3.2
gives the minimum internal diameter of the bend for the material.
From that for HR3 material chose the bending radius as close as
possible Table 3.2 Minimum Internal diameter of
bendS.NoGradeInternal Diameter of Bend
iHR12t
iiHR2T
iiiHR3Close
ivHR4Close
Note wheret is the thickness of work piece3.1.4 Delivery
condition The material may be supplied in any one (or, in
combination) of the following conditions a) Hot rolled,b)
Annealed,c) Normalized, andd) DescaledFrom the supplier the company
purchase the sheet as straight strips. This avoids the extra cost
and time of straightening and cutting of sheets from the coil.
3.2 DIE MATERIAL According to IS 4957: 1999 standard, high
carbon high chromium steels (HCHC). D2 (Common name) is the popular
choice of the tool makers material. The material should have Good
wear resistance High toughness High dimensional stability3.2.1
Chemical compositionTable 3.3 shows the chemical composition of the
die material which as a high percentage of chromium.Table 3.3
Chemical composition of die materialConstituentCarbon Chromium
Manganese Vanadium Molybdenum
Percentage1.55% 12.00% 0.45% 0.80% 0.85%
3.2.2 Mechanical properties Density= 7700 kg / mm3 Rockwell
hardness = 65 Poisons ratio = 0.27-0.3 Elastic modulus = 190 210
GPa. Ultimate tensile strength = 260 390 GPa 3.3 MANUFACTURING
PROCESSSimple work flow from the sheet strip to the bracket
assembly is illustrated in the flow chart shown in fig.3.1
Fig3.1 Process flow chart3.3.1 Sheet strip cutting:The company
purchases the sheets in strip condition as shown in fig.3.2.
Fig 3.2 Sheet strip
3.3.2 Piercing, Notching and BlankingA progressive tool is used
to make the piercing, notching and blanking operation from the
sheet strips. In the progressive tool first the holes are pierced
and the center notch operation is done finally the component
blanked out as shown in fig. 3.3.
Fig 3.3 Blank
3.3.3 Company identity marking Company identity marking is done
using a hand press. The identity denotes that the company name and
the year and month of manufacturing as shown in fig.3.4.
Fig. 3.4 Marking 3.3.4 First formingFig 3.5 shows the component
after first forming. During this operation two embossing and a
v-bending operation is done in a single stroke. Locating pins are
used to place the component in the die. The company has employed a
20 ton capacity mechanically operated press to do this work.
Fig.3.5 First forming3.3.5 Second formingAfter the first forming
another side of the blank is formed in this stage. During this two
v-bending operations and two embossing operations are done.
Currently a 20 ton capacity mechanically operated press is used for
this forming. Fig 3.6 shows the final component after second
forming operation.
Fig.3.6 Second forming3.3.6 FoldingIt is a form of channel
bending. A die with suitable recess used to place the component. A
rectangular tool is used to make the folding as shown in
fig.3.7.
Fig. 3.7 Folding3.3.7 Acid cleaning:To remove the dust and
impurity layer around the material acid cleaning followed by the
water rinsing is done. During this stage the color change predicts
the impurity removal rate.3.3.8 Powder coatingAfter the cleaning
the powder coating sprayers and systems are used to spray black
powder around the component. Then the powder coated component is
heated in the oven at 1900C. At this temperature the powder melts
and sticks with the component as shown in figure 3.8
Fig. 3.8 Powder cleaning3.3.9 AssemblyIn the assembly as shown
in fig. 3.9 all the parts of side stand are assembled with the
Bracket through rigid connections.
Fig. 3.9 Assembly
CHAPTER 4DESIGN CONSIDERATION AND CALCULATION4.1 DESIGN
CONSIDERATION4.1.1 Marking Marking of company identity is done by
the coining operation. Coining is a form of precision stamping in
which a work piece is subjected to a sufficiently high stress to
induce plastic flow on the surface of the material. Coining is a
cold working process that uses a great deal of force to plastically
deform a work piece, so it conforms to adie. It can be done using a
gear driven press, a mechanical press, or more commonly, a
hydraulically actuated press. In this process any of the male or
female die has an impression and the other one is flat. During this
operation the load applied to the component is to be limited.
Because the load should not cut or damage the component.4.1.2
Embossing Embossing is a process for producing raised or sunken
designs or relief in sheet metal. This process can be made by means
of matched male and female roller dies, or by passing sheet or a
strip of metal between rolls of the desired pattern. Embossing
process has these characteristics The ability to formductilemetals.
Use in medium to high production runs. The ability to maintain the
same metal thickness before and after embossing. The ability to
produce unlimited patterns, depending on the roll dies. The ability
to reproduce product with no variation. Provide the stiffness to
the component Increase the bending strength4.1.3 Bending: Sheet
metal bending is the plastic deformation of the work over an axis,
creating a change in the part's geometry. This produces a V-shape,
U-shape, or channel shape along a straight axis in ductile
materials, most commonly sheet metal. The bending is used in the to
produce an angled component, sheet profile, shipbuilding, apparatus
manufacturing and common household things4.1.4 V- Bending:In V-
bending either the male and female die or any both of them must
have the V shape. In this top die forces the component in to the
bottom die.4.1.5 Air bending:This bending method forms material by
upper or top V-die into the material, forcing it into a bottom die,
which is mounted on the press. The punch forms the bend so that the
distance between the punch and the side wall of the V is greater
than the material thickness (T).Either a V-shaped or square opening
may be used in the bottom die as shown in fig.4.1. A set of top and
bottom dies are made for each product or part produced on the
press. As it requires less bend force, air bending tends to use
smaller tools than other methods.Some of the newer bottom tools are
adjustable, so, by using a single set of top and bottom tools and
varying press-stroke depth, different profiles and products can be
produced. Different materials and thicknesses can be bent in
varying bend angles, adding the advantage of flexibility to air
bending. There are also fewer tool changes, thus gives higher
productivity.A disadvantage of air bending is that, because the
sheet does not stay in full contact with the dies, it is not as
precise as some other methods, and stroke depth must be kept very
accurate. Variations in the thickness of the material and wear on
the tools can result in defects in parts produced. Air bending's
angle accuracy is approximately 0.5 deg. Angle accuracy is ensured
by applying a value to the width of the V opening, ranging from 6 T
(T- material thickness) for sheets to 3 mm thick to 12 T for sheets
more than 10 mm thick. Spring back depends on material properties,
influencing the resulting bend angle.
Fig. 4.1 Air bending4.1.6 Bottoming: In bottoming, the sheet is
forced against the V opening in the bottom tool as shown in fig.
4.2. U-shaped openings cannot be used. Space is left between the
sheet and the bottom of the V opening. The optimum width of the V
opening is 6 T for sheets about 3 mm thick, up to about 12 T for 12
mm thick sheets. The bending radius must be at least 0.8 T to 2 T
for sheet steel. Larger bend radius require about the same force as
larger radii in air bending, however, smaller radii require greater
force up to five times as much than air bending. Advantages of
bottoming include greater accuracy and less springback. A
disadvantage is that a different tool set is needed for each bend
angle, sheet thickness, and material.
Fig. 4.2 Bottoming4.1.7 Wiping:In wiping, the longest end of the
sheet is clamped, then the tool moves up and down, bending the
sheet around the bend profile as shown in fig.4.3. Though faster
than folding, wiping has a higher risk of producing scratches or
otherwise damaging the sheet, because the tool is moving over the
sheet surface. The risk increases if sharp angles are being
produced. Wiping on press brakes involves special tools. This
method will typically bottom or coin the material to set the edge
to help overcome springback. In this bending method, the radius of
the bottom die determines the final bending radius.
Fig. 4.3 Wiping4.1.8 Spring back:Spring back is the geometric
change made to a part at the end of the forming process when the
part has been released from the forces of the forming tool. Upon
completion of sheet metal forming, deep-drawn and stretch-drawn
parts spring back and thereby affect the dimensional accuracy of a
finished part. The final form of a part is changed by spring back,
which makes it difficult to produce the part. This is due to the
plastic-elastic forming of a work piece, at the end of a bending
process. When bending is done, the elastic stresses causes the
material to spring back towards its original position, so the sheet
must be over-bent to achieve the proper bend angle. InFig.4.4, the
final bend angle after springback (af) is smaller than the bend
angle before springback (ai), and the final bend radius after
springback (Rf) is larger than the bend radius before springback
(Ri).It is difficult to predict springback because many variables
affect it, such as material properties, tool geometry, sheet
thickness, and punch stroke. As a rule, however, the smaller the
punch radius, the smaller the springback, and the greater the
bending angle, the greater the springback.
Fig 4.4 Illustration of spring backThe spring back has to be
compensated to achieve an accurate result. Usually that is realized
by over-bending the material correspondent to the height of the
spring back. That means for the practical side of the bending
process, the bending former enters deeper into the bending prism.
In the case of complex tools the spring back has to be already
considered in the construction phase. Therefore complex software
simulations are used. Frequently this is not enough to deliver the
desired results. In such cases practical experiments are done,
using the trial-and-error plus experience method to correct the
tool. The spring back angle also depends upon the bend angle and
the material properties. A spring back is compensated by two ways
1.Over bending the sheet to get the proper bent angle. 2.Bottoming
or squeezing the material at the bend line.In bottoming this the
metal gets squeezed in the bottom die. This reduces the spring back
by holding the metal at the bottom of the die.4.1.9 Spring back
compensationIn this work embossing gives the additional stiffness
to the bend angle and it reduces the spring back of the material.
Based on the internal bending radius and tensile strength of the
spring back angle is selected from the table 4.1[10] For tensile
strength 300 N / mm2 and Bending radius below the thickness of the
sheet Table 4.1 Spring back angle compensationBend angle906030
Spring back angle4.73.11.6
4.2 DESIGN CALCULATION4.2.1 Force required for Identity marking
Coining force = Perimeter x Depth of impression x Tensile strength
Avg. perimeter = 120 mm (calculating by measuring the outside
length of the letters) Force = 120 x 0.5 x 300 = 18,000 N4.2.2
Force required for embossing Embossing Force = Perimeter (P) x
Average embossing depth (D) x Tensile strength (S)During first
forming: For small embossing, Force = P x D x S = 42 x 3 x 300 =
37,900 N For long embossing, Force = P x D x S = 58 x 6 x 300 =
1,04,400 N
During second forming: For small embossing, Force = P x D x S
=38 x 2 x 300 = 22,800 N For long embossing, Force = P x D x S = 56
x 3 x 300 = 50,400 N4.2.3 Force required for bending The V- bending
force is calculated using the standard formula[9]
k = Bending factor = 1.33 s = ultimate tensile strength l =
length of bend t = thickness w = die opening = 8t
= 5236.8 N = 5237 N Here V- bending takes place in three places.
So, three times of the bending force is required. Total force =
18000 + 37900 + 104400 + 22800 + 50400 +5237 x 3 = 249211 N = 25
tons (approximately)4.3.4 Press selection and specification: 25 ton
force is required to for the component. Considering the safety and
availability, the press of 30 tons is selected. The specifications
are given in the table 4.2.Table 4.2 Press specificationsCapacity30
tons
TypeC Frame
Table size450 x 500
Shut height275 mm
Stroke length75 mm
Ram Adjustment30 mm
Strokes per minute65
Power required3 H.P
Gross weight19000 N
Capacity of press - The maximum amount of force produced by the
press during its operation. C type Frame - The base and the head
are connected through the C type frame.Shut height - For a press,
this is the distance from the top of the bed to the bottom of the
slide with the stroke down and adjustment up[7]. In general, it is
the maximum die height that can be accommodated for normal
operation, taking the bolster plate into consideration as shown in
fig.4.5.Stroke length - It is the distance travelled by the ram
during the half stroke of the press without considering the ram
adjustment..Fig 4.5 Shut height of press4.3.5 Tool height Max. Tool
height = Shut height adjustment = 275 10 = 265 mm Min. Tool height
= Max. Tool height - Ram Adjustment = 265 -30 = 235 mm Optimum tool
height = Min. Tool height + regrind allowance = 235 + 15 =250
mm4.3.6 Hexagonal socket headed screw: It is used to connect the
bottom plate and top plate with the die sets. Material
Specification: ASTM A574M / DIN ENISO4762-alloy steel Hardness: RC
38 43 Max. Permissible stress on the threads: 120 N / mm2 No of
Screws: 8
= 14.86 mm Major diameter of thread D = dc / 0.8 = 18 mm
(approximately) M18 Screw is selected According to IS 2269: 1967
and the various dimensions of the screw are selected. Based on PSG
design data book[6] the various dimensions are shown in the fig.
4.6.
Fig. 4.6 Hexagonal socket headed screw4.3.7 Die set Standard die
sets are selected from manufacturers catalogue[8] based on the size
of the table and availability. Fig. 4.7 gives the various
dimensional parameters used in the die sets and table 4.3 provides
dimensions accordingly. Fig 4.7 Die set parametersA B A1 C1 C2 E
P
315 200 171 50 50 225 45
Table 4.3 Die set parameter dimensions4.3.8 Pillar set
Corresponding to the die set, the pillar set of 30 mm diameter
should be recommended by the manufacturers catalogue[8].Pillar
length = Tool height Regrind allowance (two sides) = 250 40 = 210
mm 4.3.9 Bush set Corresponding to the die set, the bush set of 55
mm outer diameter and 30 mm inside diameter has to be
recommended[8]. Pillar length = (stroke length + Regrind allowance)
+ (Bolt thickness Base allowance) = (75 + 15) + (50 -20) = 90 + 30
= 120 mm
CHAPTER 5MODELLING OF TOOL5.1 INTRODUCTIONComputer aided
Engineering (CAE) makes the component drawing and drafting easy.
Now with the help of CAE complete study of component with their
proper function, even with the optimized condition is possible
before the component has to be manufactured. Using the CREO v2.0
CAE software package the component and the tools were modeled and
assembled. CREO platform helps easily for this work. As there is
separate module called CREO- Sheet metal specially constructed for
sheet metal works.5.2 COMPONENT MODEL IN SEQUENCE:Component is
modeled based on the drawing specified by the TI cycles of India
using the CREO. The various views of the drawings should be
thoroughly understood then only integration of those details with
the software package is possible.5.2.1 Blank modelling:Blank is
modeled based on the dimensions. Initially component is generated
as a solid part modelling. After the various operations are done
the component is converted as a sheet metal as shown in fig.5.1.
Fig.5.1 3D Model of blank5.2.2 First formingDuring this operation
two embossing and a v-bending operation are done in a single
stroke. For the convenience of modeling the component has to be
modeled without embossing. In the software environment the bend
line, bent surface (top) and the bend angle of 300 are the data to
be provided to make the component bent in the sheet metal module.
The component after first forming is shown in fig.5.2.
Fig. 5.2 First forming5.2.3 Second formingAfter the first
forming the other side of the blank is formed in this stage. During
this stage two v-bending operations and two embossing operations
are done. In this two bending operations, first a 900 bent is
provided adjacent to the center notch and a 600 bent is provided 4
mm after the 900 bent as shown in fig. 5.3.
Fig 5.3 Second forming5.3 DIE MODEL5.3.1 Bottom die ModelBefore
the die has to be modeled the component placement is an important
criteria, as this decides the top and bottom die profile. In this
work integration of identity marking tool places an important role.
Fig.5.4 shows the 3-D view of the solid model of bottom die.The
marking tool must be a replaceable one. It should be changed every
month. So due to the gravity issue it should be placed on the
bottom die.It should contain the locating pins to place the
component in a bottom die. The placement is based on the recess
provided on the component. It constrains the component on the die.
Fig 5.5 shows the location of the blank on the bottom die.5.3.2 Top
die modelThe top die has an opposite impression of the bottom die.
Additionally it is also provided with a recess for the locating pin
movement. The fig. 5.6 shows the solid model of Top die.5.3.3
Modelling of supporting elementsSupporting elements are the one
which make the die as a tool. Based on the dimensions are
calculated on the chapter 4, the models are created in the CREO
solid model environment. The solid models of the various elements
such as top plate, bottom plate, pillars, bushes, and hexagonal
socket headed screw are shown in the fig.5.6Fig. 5.7 shows the
complete assembly of the die set.
Provision for identity marking toolLocating pins
Fig. 5.4 Bottom die Model
Recess for locating pins
Fig. 5.6 Top die model
BlankLocating pinsBottom die
Fig.5.5 Location of blank on the bottom die
Bottom plate Hexagonal socket headed screws Pillar Bush Top
plate
Fig. 5.7 Assembly of supporting elements in tool set
Fig 5.8 Assembly of the die set
CHAPTER 6CONCLUSION6.1 CONCLUSION The study of the processes and
problem involved in the manufacturing of the sheet metal component
with multiple bends (bracket) have been carried out. The individual
steps of operation of the component have been modeled separately
using the CREO sheet metal environment. Total force required for
the component, material selection and press selection have been
carried out. A suitable die for the component with the various
forming processes has been designed along with the supporting
elements such as top plate, bottom plate, bush, pillar, and
hexagonal socket headed screw and modeled. The profile of the die
was taken as the impression from the component. Provision for
marking tool is given on the bottom die. Locating pins have been
provided to place the component in the die.6.2 FUTURE WORK So far
the die model has been created without considering the embossing
aspect. The second phase of this project will focus on designing
the die model taking into consideration embossing also Designed die
has to be analysed to determine the stress and critical sections.
Process simulation of the component will be carried out. Simulating
the process of the component will give the better idea and improve
understanding of the formability of the component.
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