-
1
CHAPTER-1
INTRODUCTION 1.1 INTRODUCTION
Now days the development of industries has become the key
area
for the engineers. In this dynamic cycle of industrial world
they innovate
every machine for their purpose of their own needs.
1.2 HISTORY
The AMREP ltd group which is the leading industry with the
production of clutch plates for the heavy vechiles tie up with
more
industries over the seas.
The group starts with the collaboration with Repco limited
in
Australia at the year 1967.
In 1970 it results with the commercial production of clutch
assembly and components to automotives.
After this the company solved many complicated and more
potential problems to withstand the organisation with the fast
moving
automotives industries in the world.
The organisation which has tendency to produce more than
3000
products/per day.
1.3 PRODUCTS
Clutch cover plate.
Clutch driven plate.
Clutch service kit.
Release lever kit.
Spring kit.
Lever plate kit.
-
2
1.4 DEALERS
Passengers car :
Maruti car
Bajaj minidor
Hindustan trekker
Ambassador
Light commercial vehicle :
Tata sumo
Mahindra jeep
Bajaj tempo trax/traveller
Mahindra-EC150/FC160
Medium and commercial vehicles :
Tata 1210D/TMB
Tata 1210/SE/1312/1313/1510
Ashok Leyland comet/viking/tarus/hippo/beaver
Tractor
TAFE
Eicher
Swaraj
Mahindra
John deere
1.5 MANUFACTURING PROCESS
Press shop
Machine shop
Driven plate assembly
Cover assembly area
-
3
1.6 TOOLS AND PRODUCT MAINTAINING AREA
Tool room
Rework area
Inspection of products.
1.7 IMPROVEMENT OF PRODUCTION
Total productivity management
Quality analyser
Design and development
FIGURE 1.1 : AMALGAMATION REPCO LIMITED
-
4
CHAPTER-2
LITERATURE SURVEY
2.1 INTRODUCTION
In the existing process the organization which has to
produce
clutch plates with the help of single riveting machine. The
process which leads
to increase the operator fatigue and increases the production
time. The project
which deals with the designing of the gang riveting fixture for
the production of
driven plates assembly. The gang riveting fixture which helps to
reduces the
process of individual riveting with main plate and segment
riveting. The
specifications of the riveting machine and the hydraulic press
machine are
explained below.
2.2 RIVETING MACHINE
The function of riveting machine is used to join together the
two
products by using the rivets.
Pedestal riveting machines is used where the component length
is
long & it has to hold vertically only. Also these machines
can adjust
components with different lengths by adjusting moving fixtures
up down.
2.3. FEATURES
Microsmatic Stroke adjustment
Head up & down movement arrangement
Operator Panel with auto/manual
Foot switch
Robust Base & Frame Construction
Advantages
Smooth & crack free surface finish
Smaller press can be used compared to impact pressure
Less noise during forming
Long tool life
-
5
FIGURE 2.1 : RIVETING MACHINE
Setting facility for quality riveing
Different types of forming heads possible
Less maintenance
Cost saving
Easy to operate
Optional
Anti-tie 2 hand cycle start push button
Fixtures as per components
Job counter
-
6
Input air pressure switch
PLC controlled Panel
Machine lamps
With extra shut height & throat depth
Possible Rivet Profiles
Conical
Flat
Crown
Eyelet
Semi-tubular
2.4 HYDRAULIC MACHINE PRESS
The hydraulic punching machine which is used to make the
joints
of two components with the help of bottom and top die plates. In
this machine
the punching process is done with the maximum load applicable
for the product
and this must not causes any damages to the product.
Hydraulic punch presses, which power the ram with a
hydraulic
cylinder rather than a flywheel, and are either valve controlled
or valve and
feedback controlled. Valve controlled machines usually allow a
one stroke
operation allowing the ram to stroke up and down when
commanded.
Controlled feedback systems allow the ram to be proportionally
controlled to
within fixed points as commanded. This allows greater control
over the stroke
of the ram, and increases punching rates as the ram no longer
has to complete
the traditional full stroke up and down but can operate within a
very short
window of stroke.
-
7
FIGURE 2.2 : HYDRAULIC MACHINE PRESS
Hydraulic presses are commonly used for
forging
clinching
moulding
blanking
punching
deep drawing
metal forming
The hydraulic punch which is used to make the rivets with a
single stroke,which
has the following function
Time consumption
Operator fatigue
Increased productivity
-
8
FIGUR 2.3 OUTLINE OF GANG RIVETING FIXTURE
TOP PAD
PUNCH HOLDER
STRIPPER PLATE
BOTTOM - DIE
STRIPPER PLATE
PUNCH HOLDER
BOTTOM PAD
TOP - DIE
-
9
2.5 OBJECTIVE OF THE PROJECT
The main objective of this research is to design and develop jig
and
fixture for riveting the clutch to be used in engine assembly.
Among the
other objectives want to achieve are follows:
i. To identify current jigs and fixtures limitation and design
technology
availability
ii. Carried out data collection based on need engine assembly
used to
clutch rivet at machine press.
iii. To design and fabricate a jig and fixture press rivet based
on data
collection.
iv. To validity the performance of jig and fixture at driven
plate assembly
of clutch plate.
2.6 SCOPE OF STUDY
Scope of assumption for this research is to design and produce
jig press
rivet clutch . These jigs and fixture are used at main assembly
line to assemble
the components. The jig and fixture design based on data
clutch
specification, the data from machine press also accounts to
realize this study.
All the data collected based on references from the
organisation.
2.7 PROBLEM STATEMENT
The description of common jig and fixture in use today suggests
that jig
and fixture are currently designed for a specific task on
specific part geometry.
There is only limited flexibility in using the same jig and
fixture for different
part shapes and sizes. In order to comply with the needs of
smaller batch sizes
of the future jig and fixture should also be redesigned with a
view to make them
flexible and versatile to increase productivity. The goal of the
jig and fixture
design today is to provide user some guidance so that these
guides can be used
for a wide variety of part sizes, shapes, materials and weights.
In this research, a
-
10
subset of this problem has been addressed the jig and fixture
press rivet for
clutch motorcycle engine assembly. Use a different jig and
fixture for different
model can give effect to production when assemble the clutch at
motorcycle
engine, which is takes a longer time when changing the jig and
fixture. Based
on the problem has it, a study is carried out to develop a jig
and fixture can be
used for all models in general to assemble clutch, however
special focus is
given for 11054 models.Therefore the design this jig and fixture
can be increase
a production and save cost,when jig and fixture established at
assembly line
production.
2.8 IMPORTANT OF THE PROJECT
This project is important in order to generate the design that
can be
improved a jig and fixture design assembly. Moreover the design
also can
reduce the time to assemble clutch rivet and increase
production. In addition it
also can encourage others to get some idea and knowledge to
develop jig and
fixture for press base on this research. Study of suitable jig
and fixture used for
press rivet operation to get the best design and can implement
at real
environment.
-
11
CHAPTER - 3
COMPONENTS DESCRIPTION
3.1 CLUTCH
A clutch is a mechanical device that provides for the
transmission of
power (and therefore usually motion) from one component (the
driving
member) to another (the driven member) when engaged, but can be
disengaged.
3.2 MATERIALS
Various materials have been used for the disc-friction facings,
including
asbestos in the past. Modern clutches typically use a compound
organic resin
with copper wire facing or a ceramic material. A typical
coefficient of friction
used on a friction disc surface is 0.35 for organic and 0.25 for
ceramic. Ceramic
materials are typically used in heavy applications such as
racing or heavy-duty
hauling, though the harder ceramic materials increase flywheel
and pressure
plate wear.
3.3 PUSH/PULL
Friction-disc clutches generally are classified as push type or
pull
type depending on the location of the pressure plate fulcrum
points. In a pull-
type clutch, the action of pressing the pedal pulls the release
bearing, pulling on
the diaphragm spring and disengaging the vehicle drive. The
opposite is true
with a push type, the release bearing is pushed into the clutch
disengaging the
vehicle drive. In this instance, the release bearing can be
known as a thrust
bearing (as per the image above).
-
12
3.4 DAMPERS
A clutch damper is a device that softens the response of the
clutch
engagement/disengagement. In automotive applications, this is
often provided
by a mechanism in the clutch disc centres. In addition to the
damped disc
centres, which reduce driveline vibration, pre-dampers may be
used to reduce
gear rattle at idle by changing the natural frequency of the
disc. These weaker
springs are compressed solely by the radial vibrations of an
idling engine. They
are fully compressed and no longer in use once the main damper
springs take up
drive.
3.5 LOAD
Mercedes truck examples: A clamp load of 33 kN is normal for a
single
plate 430. The 400 Twin application offers a clamp load of a
mere 23 kN.
Bursts speeds are typically around 5,000 rpm with the weakest
point being the
facing rivet.
3.6 MANUFACTURING
Modern clutch development focuses its attention on the
simplification of
the overall assembly and/or manufacturing method. For example
drive straps
are now commonly employed to transfer torque as well as lift the
pressure plate
upon disengagement of vehicle drive. With regard to the
manufacture of
diaphragm springs, heat treatment is crucial. Laser welding is
becoming more
common as a method of attaching the drive plate to the disc ring
with the laser
typically being between 2-3KW and a feed rate 1m/minute. Types
are discussed
below.
3.6.1 MULTIPLE PLATE CLUTCH
This type of clutch has several driving members interleaved or
"stacked"
with several driven members. It is used in race cars
including F1, IndyCar, World Rally and even most club
-
13
racing,motorcycles, automatic transmissions and in some
diesel
locomotives with mechanical transmissions. It is also used in
some
electronically controlled all-wheel drive systems as well as in
some transfer
cases.
3.6.2 WET & DRY
A wet clutch is immersed in a cooling lubricating fluid that
also keeps
surfaces clean and provides smoother performance and longer
life. Wet
clutches, however, tend to lose some energy to the liquid. Since
the surfaces of
a wet clutch can be slippery (as with a motorcycle clutch bathed
in engine oil),
stacking multiple clutch discs can compensate for the lower
coefficient of
friction and so eliminate slippage under power when fully
engaged. The Hele-
Shaw clutch was a wet clutch that relied entirely on viscous
effects, rather than
on friction.
A dry clutch, as the name implies, is not bathed in liquid and
should be,
literally, dry.
3.6.3 CENTRIFUGAL
A centrifugal clutch is used in some vehicles (e.g., mopeds) and
also in
other applications where the speed of the engine defines the
state of the clutch,
for example, in a chainsaw. This clutch system employs
centrifugal force to
automatically engage the clutch when the engine rpm rises above
a threshold
and to automatically disengage the clutch when the engine rpm
falls low
enough. The system involves a clutch shoe or shoes attached to
the driven shaft,
rotating inside a clutch bell attached to the output shaft. The
shoe(s) are held
inwards by springs until centrifugal force overcomes the spring
tension and the
shoe(s) make contact with the bell, driving the output. In the
case of a chainsaw
this allows the chain to remain stationary whilst the engine is
idling; once the
-
14
throttle is pressed and the engine speed rises, the centrifugal
clutch engages and
the cutting chain moves. See Saxomat and Variomatic.
3.6.4 CONE CLUTCH
As the name implies, a cone clutch has conical friction
surfaces. The
cone's taper means that a given amount of movement of the
actuator makes the
surfaces approach (or recede) much more slowly than in a disc
clutch. As well,
a given amount of actuating force creates more pressure on the
mating surfaces.
The best known example of a cone clutch is a synchronizer ring
in a manual
transmission. The synchronizer ring is responsible for
"synchronizing" the
speeds of the shift hub and the gear wheel to ensure a smooth
gear change.
FIGURE 3.1 : CLUTCH
-
15
3.7 ASSEMBLY PROCESS
The child parts which are gather around from some other
organisation
and some of them are manufactured from here itself.
The process is carried with the following steps:
SPRING ASSEMBLY
STOP PIN RIVETING
MAIN PLATE FACING RIVETING
FACING SEGMENT SUB ASSEMBLY
DRIVEN PLATE ASSEMBLY
1. SPRING ASSEMBLY:
The drive function needs to be carefully reviewed to select the
correct
clutch for an application. The spring assembly which helps to
reduce the
damper ratio which carried out to release load applied to the
clutch regain its
original shape.
FIGURE 3.2 SPRING ASSEMBLY
-
16
The spring assembly which consist of the following :
Damper spring - 8 Nos
Cushion segment - 6 Nos
Shim/Friction washer - as required
Waved washer - 1
2.STOP PIN RIVETING:
The stop pin riveting process which helps to join the side plate
and main
plate segments.
FIGURE 3.3 : SIDE PLATE
The above figure which is the side plate,in this process the
side plate which is
get riveted wwith the spring assembled hub.
-
17
3.MAIN PLATE FACING RIVETING:
The main plate facing segment riveting process,which is one part
of the
clutch driven plate. It is the next process to the stop pin
riveting process,it
consist of the rivet facing segment.
FIGURE 3.4 FACING SEGMENT
The main plate comes along with the facing segment in this the
riveting consist
of 24 rivets along in it.
In this the rivet which is used as said to be 2 rivet (i.e., the
size of rivet) of semi-
tubular rivets.
-
18
4.FACING SEGMENT : SUB-ASSEMBLY:
In this process the facing segment and the sub assembly part
which
undergoes to the riveting function. The process carried out with
the use of
riveting machine.
FIGURE 3.5 : FACING SEGMENT AND SUB ASSEMBLY
-
19
5.DRIVEN PLATE ASSEMBLY:
The driven plate assembly which is the last step to finish the
product of
the clutch plate. In this process the assembled parts of main
plate segment and
the facing segment sub assemblies are taken together to the
final riveting
process to complete the assembly of the driven plate of
clutch
FIGURE 3.6.DRIVEN PLATE ASSEMBLY
-
20
3.8 PARAMETER OF MACHINE PRESS
The Machine which is controlled by using the hydraulic supply
for the
attaining of proper punch with loads to be applied as required
.
FIGURE 3.7. HYDRAULIC MACHINE PRESS
-
21
3.9 INTODUCTION TO JIG AND FIXTURE
3.9.1 Jigs
A JIG is a type of custom-made tool used to control the location
and/or
motion of another tool. A jig's primary purpose is to
provide repeatability, accuracy, and interchangeability in the
manufacturing of
products.[1] A jig is often confused with a fixture; a fixture
holds the work in a
fixed location. A device that does both functions (holding the
work and guiding
a tool) is called a jig
3.9.2 Fixtures
A fixture is a work-holding or support device used in
the manufacturing industry. Fixtures are used to securely locate
(position in a
specific location or orientation) and support the work, ensuring
that all parts
produced using the fixture will maintain conformity and
interchangeability.
Using a fixture improves the economy of production by allowing
smooth
operation and quick transition from part to part, reducing the
requirement for
skilled labour by simplifying how workpieces are mounted, and
increasing
conformity across a production run.
A fixture differs from a jig in that when a fixture is used, the
tool must move
relative to the workpiece, a jig moves the piece while the tool
remains
stationary.
3.9.3 Objectives of jigs and fixtures
introduction of jigs and fixtures,
purpose and advantages of jigs and fixtures,
important considerations while designing jigs and fixtures,
know the meaning and principles of location,
describe the different types of locations,
explain the clamping and its different type,
-
22
the requirements of a good clamping device,
know the different types of clamp,
explain the jigs and their different types, and
know about the milling fixtures.
3.9.4 PURPOSE AND ADVANTAGES OF JIGS AND FIXTURES
Following the purpose and advantages of jigs and fixtures :
(a) It reduces or sometimes eliminates the efforts of marking,
measuring and
setting of workpiece on a machine and maintains the accuracy of
performance.
(b) The workpiece and tool are relatively located at their exact
positions before
the operation automatically within negligible time. So it
reduces product cycle
time.
(c) Variability of dimension in mass production is very low so
manufacturing
processes supported by use of jigs and fixtures maintain a
consistent quality.
(d) Due to low variability in dimension assembly operation
becomes easy, low
rejection due to les defective production is observed.
(e) It reduces the production cycle time so increases production
capacity.
Simultaneously working by more than one tool on the same
workpiece is
possible.
(f) The operating conditions like speed, feed rate and depth of
cut can be set to
higher values due to rigidity of clamping of workpiece by jigs
and fixtures.
(g) Operators working becomes comfortable as his efforts in
setting the
workpiece can be eliminated.
(h) Semi-skilled operators can be assigned the work so it saves
the cost of
manpower also.
-
23
(i) There is no need to examine the quality of produce provided
that quality of
employed jigs and fixtures is ensured.
3.10 IMPORTANT CONSIDERATIONS WHILE DESIGNING JIGS AND
FIXTURES
Designing of jigs and fixtures depends upon so many factors.
These factors are
analysed to get design inputs for jigs and fixtures. The list of
such factors is
mentioned below :
(a) Study of workpiece and finished component size and
geometry.
(b) Type and capacity of the machine, its extent of
automation.
(c) Provision of locating devices in the machine.
(d) Available clamping arrangements in the machine.
(e) Available indexing devices, their accuracy.
(f) Evaluation of variability in the performance results of the
machine.
(g) Rigidity and of the machine tool under consideration.
(h) Study of ejecting devices, safety devices, etc.
(i) Required level of the accuracy in the work and quality to be
produced.
-
24
3.11 MEANING OF LOCATION
It is very important to understand the meaning of location
before
understanding about the jigs and fixtures. The location refers
to the
establishment of a desired relationship between the workpiece
and the jigs or
fixture correctness of location directly influences the accuracy
of the finished
product. The jigs and fixtures are desired so that all
undesirable movements of
the workpiece can be restricted. Determination of the locating
points and
clamping of the workpiece serve to restrict movements of the
component in any
direction, while setting it in a particular pre-decided position
relative to the jig.
Before deciding the locating points it is advisable to find out
the all possible
degrees of freedom of the workpiece. Then some of the degrees of
freedom or
all of them are restrained by making suitable arrangements.
These arrangements
are called locators.
3.12 PRINCIPLES OF LOCATIONS
The principle of location is being discussed here with the help
of a most
popular example which is available in any of the book covering
jigs and
fixtures. It is important that one should understand the problem
first.
Any rectangular body many have three axis along x-axis, y-axis
and z-axis. It
can more along any of these axes or any of its movement can be
released to
these three axes. At the same time the body can also rotate
about these axes too.
So total degree of freedom of the body along which it can move
is six. For
processing the body it is required to restrain all the degree of
freedom (DOF) by
arranging suitable locating points and then clamping it in a
fixed and required
position. The basic principle used to locate the points is
desirable below.
Six Points Location of a Rectangular Block
Considering the six degree of freedom of a rectangular block .It
is made to rest
on several points on the jig body. Provide a rest to workpiece
on three points on
the bottom x-y surface. This will stop the movement along
z-axis, rotation with
respect to x-axis and y-axis. Supporting it on the three points
is considered as
-
25
better support then one point or two points. Rest the workpiece
on two points of
side surface (x-z), this will fix the movement of workpiece
along y-axis and
rotation with respect to z-axis. Provide a support at one point
of the adjacent
surface (y-z) that will fix other remaining free movements. This
principle of
location of fixing points on the workpiece is also named as
3-2-1 principle of
fixture design as number of points selected at different faces
of the workpiece
are 3, 2 and 1 respectively.
Body to be restrained (each of the axis can be divided into two
halves positive
and negative)
FIGURE 3.8 : AVAILABLE DEGREE OF FREEDOM OF
RECTANGULAR BLOCK
-
26
3.13 LOCATION OF A CYLINDER ON A VEE BLOCK
The analysis of the principle of location of a cylinder on a Vee
block is
indicated in Figure 3.9. All the degrees of freedom of the
cylindrical object are
restrained. It is only fixed to move along axis AB. It can
rotate about the axis
AB. These free movements are also indicated in the figure. If
the operation to be
done on the cylindrical object requires restriction of the above
mentioned free
movements also than some more locating provisions must also be
incorporated
in addition to use of the Vee block.
FIGURE 3.9 : LOCATING A CYLINDER ON A VEE BLOCK
3.14 DIFFERENT METHODS USED FOR LOCATION
There are different methods used for location of a work. The
locating
arrangement should be decided after studying the type of work,
type of
operation, degree of accuracy required. Volume of mass
production to be done
also mattes a lot. Different locating methods are described
below.
-
27
3.14.1 FLAT LOCATOR
Flat locators are used for location of flat machined surfaces of
the
component. Three different examples which can be served as a
general principle
of location are described here for flat locators. These examples
are illustrated in
Figure 3.10.
FIGURE 3.10: METHOD OF LOCATING USING FLAT LOCATORS
A flat surface locator can be used as shown in first figure. In
this case an
undercut is provided at the bottom where two perpendicular
surfaces intersect
each other. This is made for swarf clearance. The middle figure
shows flat
headed button type locator. There is no need to made undercut
for swarf
clearance. The button can be adjusted to decide very fine
location of the
workpiece. There can be a vertical button support as shown in
third figure,
which is a better arrangement due to its capacity to bear end
load and there is a
provision for swarf clearance automatically.
-
28
3.14.2 CYLINDRICAL LOCATORS
A cylindrical locator is shown in Figure 3.11. It is used for
locating
components having drilled holes. The cylindrical component to be
located is
gripped by a cylindrical locator fitted to the jigs body and
inserted in the drilled
hole of the component. The face of the jigs body around the
locator is undercut
to provide space for swarf clearance.
FIGURE 3.11 : CYLINDRICAL LOCATOR
3.14.3 CONICAL LOCATOR
A conical locator is illustrated in Figure 3.12 . This is used
for locating
the workpieces having cylindrical hole in the workpiece. The
workpiece is
found located by supporting it over the conical locator inserted
into the drilled
hole of the workpiece. A conical locator is considered as
superior as it has a
capacity to accommodate a slight variation in the hole diameter
of the
component without affecting the accuracy of location. Degree of
freedom along
z-axis can also be restrained by putting a template over the
workpiece with the
help of screws.
-
29
FIGURE 3.12 : CONICAL LOCATOR
3.14.3 JACK PIN LOCATOR
Jack pin locator is used for supporting rough workpieces from
the button
as shown in Figure 3.13. Height of the jack pin is adjustable to
accommodate
the workpieces having variation in their surface texture. So
this is a suitable
method to accommodate the components which are rough and
un-machined.
FIGURE 3.13: JACK PIN LOCATOR
-
30
3.14.4 DRILL BUSH LOCATOR
The drill bush locator is illustrated in Figure 3.14. It is used
for holding
and locating the cylindrical workpieces. The bush has conical
opening for
locating purpose and it is sometimes screwed on the jigs body
for the
adjustment of height of the work.
FIGURE 3.14 : DRILL BUSH LOCATOR
3.14.5 VEE LOCATORS
This is quick and effective method of locating the workpiece
with desired
level of accuracy. This is used for locating the circular and
semi-circular type of
workpieces as shown in Figure 3.15. The main part of locating
device is Vee
shaped block which is normally fixed to the jig. This locator
can be of two types
fixed Vee locator and adjustable Vee locator. The fixed type
locator is normally
fixed on the jig and adjustable locator can be moved axially to
provide proper
grip of Vee band to the workpiece.
FIGURE 3.15: FIXED V LOCATOR
-
31
3.15 CLAMPING
To restrain the workpiece completely a clamping device is
required in
addition to locating device and jigs and fixtures. A clamping
device holds the
workpiece securely in a jig or fixture against the forces
applied over it during on
operation. Clamping device should be incorporated into the
fixture, proper
clamp in a fixture directly influence the accuracy and quality
of the work done
and production cycle time. Basic requirement of a good clamping
device are
listed below :
(a) It should rigidly hold the workpiece.
(b) The workpiece being clamped should not be damaged due to
application of
clamping pressure by the clamping unit.
(c) The clamping pressure should be enough to over come the
operating
pressure applied on the workpiece as both pressure act on the
workpiece in
opposite directions.
(d) Clamping device should be capable to be unaffected by the
vibrations
generated during an operation.
(e) It should also be user friendly, like its clamping and
releasing should be easy
and less time consuming. Its maintenance should also be
easy.
(f) Clamping pressure should be directed towards the support
surfaces or
support points to prevent undesired lifting of workpiece from
its supports.
(g) Clamping faces should be hardened by proper treatments to
minimize their
wearing out.
(h) To handle the workpieces made of fragile material the faces
of clamping
unit should be equipped with fibre pads to avoid any damage to
workpiece.
-
32
3.15.1 DIFFERENT TYPES OF CLAMPS
Different variety of clamps used with jigs and fixtures are
classified into
different categories are discussed here.
3.15.2 STRAP CLAMP
This is also called edge clamp. This type clamping is done with
the help
of a lever pressure acting as a strap on the workpiece.
Different types of strap
clamps are discussed below.
Heel Clamp
The simple form of a heel clamp is shown in Figure 3.16.
Rotation of the
clamp in clockwise direction is prevented and it is allowed in
anticlockwise
direction. For releasing the workpiece the clamping nut is
unscrewed. The free
movement in anticlockwise direction takes place before
un-securing the nut to
release the workpiece.
FIGURE 3.16 : HEEL CLAMP
Bridge Clamp
The bridge clamp is illustrated in Figure3.17. It applies more
clamping
pressure as compared to heel clamp. The clamping pressure
experienced by the
workpiece depends on the distances x and y marked in the Figure
3.17 . To
-
33
release the workpiece the nut named as clamping nut is
unscrewed. The spring
lifts the lever to release the workpiece.
FIGURE 3.17 : BRIDGE CLAMP
Edge Clamp or Side Clamp
A side clamp is also known as edge clamp. In this case the
surface to be
machined is always clamped above the clamping device. This
clamping device
is recommended for fixed length workpiece. The clamping device
is illustrated
in Figure. Releasing and clamping of the workpiece can be
accomplished by
unscrewing and screwing of the clamping nut respectively
FIGURE 3.18 : EDGE CLAMP OR SIDE CLAMP
-
34
Screw Clamp
The screw clamp is illustrated in Figure 3.19. It is also known
as clamp
screw. This clamping apply pressure directly on the side faces
of the workpiece.
There is a floating pad at their end to serve the following
purposes :
(a) It prevents displacement of workpiece and slip.
(b) It prevents denting of clamping area of workpiece.
(c) The available cushion prevents deflection of screw.
In addition to the above there are some disadvantages associated
with this
method. The clamping pressure largely depends on the workpiece,
it varies from
one workpiece to other. It is more time consuming and more
efforts are
required.
FIGURE 3.19 : SCREW CLAMP
Latch Clamp
Latch clamps are used to clamp the work piece, the clamping
system is
normally locked with the help of a latch provided. To unload the
work piece the
tail end of the latch is pushed that causes the leaf to swung
open, so releasing
the work piece. Here time consumed in loading and unloading is
very less as no
screw is tightened but clamping pressure is not so high as in
other clamping
devices. Life of this type of clamping device is small.
-
35
Power Driven Clamping
Light duty clamps are used manually because small power is
required to
operate these clamps. Hand clamping leads to application of
variable pressure,
operators fatigue and more time consumed. The power driven
clamping over
comes the above mentioned problems of hand clamping. Power
clamps are
operated on the base of hydraulic or pneumatic power. Power
clamps are high
pressure clamping, these are quick acting, easily controllable,
reliable and less
time consuming.
3.16 JIGS
Jigs along with fixtures are specifically designated machine
parts, which
can be manufactured by any of the following methods : (a)
Machining, (b)
Forging, (c) Casting and (d) Complicated.
Jigs are fabricated in different pieces and joined together by
welding.
Normally jigs are made of hardened steel, which are wear
resistant, corrosion
resistant, and thermally in sensitive. Their dimensional
accuracy directly
influences the accuracy of performance of the operations where
these are used.
3.16.1 DIFFERENT TYPES OF JIGS
Different types of jigs used are described below :
3.16.2 DRILLING JIGS
Drilling jigs are used for large number of operations. Different
types of
drilling jigs are described below.
3.16.3 TEMPLATE JIG
This is a simple plate of metal or wood which carries correct
locations of
holes to be made in the workpiece. Size of template jig should
be same as that
of the workpiece. It is overlapped with the workpiece and
drilling is done
quickly. Use of this jig avoids the marking operation
completely.
3.16.4 PLATE TYPE JIG
If the work is to be done on very large scale, an improvement
can be
made to template jig that is plate type jig. This uses a plate
having drill pushes
-
36
and suitable means to hold and locate the works that it can be
clamped to the
plate and holds drilled directly through the bushes in correct
positions.
3.16.5 OPEN TYPE JIG
In this jig the top is kept open and workpiece is placed on the
base of the
jig and the drill plate. Carrying the drill bushes is placed on
the top to guide the
tool. After the operation is over, the drill plate is removed
and workpiece is
replaced.
FIGURE 3.20 : OPEN TYPE JIG
-
37
3.16.6 SWINGING LEAF TYPE JIG
This type of jig carries a leaf or plate, arranged at the top or
on one side,
which is capable of swinging about a fulcrum. It is normally the
drill plate itself
which is pivoted about a point at its one end. A swinging leaf
type jig is shown
in Figure 4.15. The work is loaded and unloaded with the help of
swinging bolt.
FIGURE 3.21 : SWINGING TYPE JIG
3.16.7 BOX TYPE JIG
Its construction is like a box and it is used for the components
having
irregular shape and to be operated at different places. This
type of jig provides
rigid support, so machining on the various places of workpiece
becomes
comfortable.
3.16.8 SOLID TYPE JIG
This is also used for drilling holes in articles of simple
shapes and
relatively smaller sizes. This is made of standard section of
rolled steel.
3.16.9 POT TYPE JIG
This jig is used for drilling holes in hallow cylindrical
components having
smaller size. Here the body of the jig is like a pot that is
used to accommodate
the workpiece comfortably. Location on the inside surface of the
component is
-
38
provided by the clamp projecting from the bush plate located
over the top of the
workpieces.
3.16.10 INDEX JIGS
This type of jig is equipped with the facility of indexing,
which creates
positional division of the workpiece suitably. This jig is used
for quick drilling
of equidistant holes on the circular surface of the workpiece.
By means of
indexing device a hole is drilled then the workpiece is moved
(indexed) to next
position under the drill bush for drilling automatically.
3.16.11 MULTI-STATION JIGS
These jigs are designed for multi-spindle machine where many
operations
can be performed simultaneously. Each spindle of the machine
carries a
different tool to perform a different operation. Tools and
spindles are arranged
in the sequence in which operations are to be performed.
3.16.12 UNIVERSAL JIG
As indicated by the name universal jigs are meant to do large
number of
operations. These may have replaceable elements on them.
Selection and
mounting of an element depends on the type of operation to be
performed.
-
39
3.17 FIXTURES
Fixtures are designed specifically for an operation and so these
are named
on the base of the operation to be carried out with their help.
Fixtures are used
to hold the workpiece properly to carryout the operations.
Different types of
fixtures are listed below.
(a) Turning fixtures
(b) Milling fixtures
(c) Fixture for grinding
(d) Fixture for broaching
(e) Fixture for boring/drilling
(f) Tapping fixture
(g) Fixture for welding
(h) Assembling fixture
-
40
CHAPTER 4
PROJECT DESCRIPTION
4.1 DESIGNING OF FIXTURE
A Fixture is a tool,which is used to examined manufactured parts
for
industry seldom will any manufactured parts be made,moved
,assembled or
inspected without the use of fixture.
Fixture might hold the raw material going into a stamping
press,load
them into the press,hold them during assembly to other parts and
hold them
during inspection.A fixture is differ fro other tools in that
they are designed to
hold a specific part during a specific operation.
4.2 CLASSIFICATION OF MACHINING FIXTURE
SURFACE MACHINING
ROTORY MOTION STRAIGHT LINE MOTION
SINGLE POINT CUTTER
LATHE FIXTURE PLANNING,SHAPING &
SLOTTING FIXTURE
MULTI-POINT CUTTER
MILLING FIXTURE FOR
CIRCULAR FEED
FIXTURES FOR CIRCULAR
GRINDING
MILLING FIXTIRE FOR STRAIGHT
LINE FEED
BROACHING FIXTURE
SURFACE FIXTURE
SAWING FIXTURE
HOLE MACHINING
SINGLE POINT CUTTER MULTI POINT CUTTER
BORING JIGS DRILL,TAPPING,REAMING JIGS
HONING AND LAPPING JIGS
TABLE 4.1 : CLASSIFICATION OF MACHINING FIXTURE
-
41
4.3 CLASSIFICATION OF MANNUAL FIXTURES
PURPOSE TYPE
PREPARATORY OPERATIONS LAYOUT FIXTURES
METALLURGICAL OPERATIONS HEAT-TREATMENT &
ANNEALINGS FIXTURE
JOINING OPERATIONS WELDING,SOLDERING,BRAZING,
RIVETING FIXTURES
WIRE-SWITCHING, CRIMPING &
ASSEMBLY FIXTURES
QUALITY CONTROL INSPECTION FIXTURE
MEASURING FIXTURE
PRESSURE TESTING FIXTURE
TABLE 4.2 : CLASSIFICATION OF MANNUAL FIXTURES
4.4 COMPONENTS OF GANG RIVETING FIXTURE
Bottom plate
Bottom pad plate
Bottom punch holder plate
Bottom stripper plate
Top stripper plate
Top punch holder plate
Top pad plate
Top plate
Shank
Centre bunk
Top punch
Bottom punch
-
42
Cap screw
Bottom insert
Top insert
Guide bush
Guide pillar
Dowel pin
SOC.Head bolt
Spring
Sleeve
4.4.1 BOTTOM PLATE
The bottom plate is the base for the gang riveting fixture; it
helps to
hold the machining surface and the punch holder. The bottom
plate is the lower
working member of the die set. Its shape corresponds with that
of the top plate
except that it is provided with clamping flanges. The flanges
have provision for
fastening the die holder to the bolster plate of the press.
Usually the bottom
plate is made thicker than the top plate. This is to compensate
for the weakening
effect of slug and blank holes. The bottom plate surface which
should be in the
following dimensions
B.P = 525*420*8 thick in mm
The material which is used in the manufacture of this plate
is
MILD STEEL.
4.4.2 BOTTOM PAD PLATES
The bottom pad plates which are used to support the bottom
plate.
In this plate which consists of several components that spring,
cap screw and the
tool die are placed over this plates.
B.P.P (OD)= 300*20 thick in mm
The material is used here is mild steel
-
43
4.4.3 BOTTOM PUNCH HOLDER
The bottom punch holder which consist of punch, machining
surface placed over this plate
B.P.H (OD)= 300*30 thick in mm
The material is used in this component are Oil Hardened Non-
shrinking Steel (OHNS)
4.4.4 BOTTOM STRIPPER PLATE
This plate, which is consist of the fixed plate position to hold
the clutch plates and assembly plates.
B.S.P (OD) = 300*30 thick in mm
The material used in this is MILD STEEL
4.4.5 TOP PLATES
Likewise the bottom plates which are similar to the top plate
the work holding devices are fixed along the requirements, the
components and dimensions are similar to the bottom plates
FIGURE 4.1: EXAMPLE OF TOP & BOTTOM PLATES
-
44
4.4.6 GUIDE BUSHES
Guide bushes are precision ground bushes which are press
fitted
into accurately bored holes in the top plate. The guide bush
which is required to
reduce the vibration and the mis alignment caused due to the
surface finish and
during the machining process.
G.B I (OD*ID*Lg) =64 *40*115
G.B II (OD*ID*Lg) = 62*38*115
The materials used in this are OHNS
FIGURE 4.2: GUIDE BUSHES
4.4.7 GUIDE PILLAR
Guide pillars are precision ground pins which are press fitted
into accurately bored holes in the bottom plate. Guide pillars are
assembled into corresponding guide bushes to align punch and die
components with a high degree of accuracy. The commonly used type
of pillars Small diameter guide pillars which are usually hardened
and centre less ground. Large diameter pillar which are ground
between centres after hardening or case hardening. Removable guide
pillars can be easily removed from the die set for resharpening the
cutting elements. They are employed for large dies and for dies
having more than two pillars.
-
45
G.P I(OD * Lg) = 50*210 in mm
G.P II(OD * Lg) = 50* 240 in mm
The materials used in this are OHNS
FIGURE 4.3: GUIDING PILLARS
4.4.8 SHANK
The shank is the end of a drill bit grasped by the chuck of a
drill.
The cutting edges of the drill bit contact the workpiece, and
are connected via
the shaft with the shank, which fits into the chuck. In many
cases a general-
purpose arrangement is used, such as a bit with cylindrical
shaft and shank in a
three-jaw chuck which grips a cylindrical shank tightly.
Different shank and
chuck combination can deliver improved performance, such as
allowing higher
torque, greater centering accuracy, or moving the bit, but not
the chuck, with a
hammer action.
SHANK (OD * Lg) = 83*76 in mm
The materials used in this are MILD STEEL
-
46
FIGURE 4.4 : SHANK
4.4.9 SOCKET HEAD BOLT
Are high-strength tension fasteners designed for clamping
assemblies and are commonly used in tool and die fixturing
applications. Socket
Screws, also known as Allen head screws, are available in
several head styles
and materials. Used in many applications, Socket Screws are
reliable and
durable.
SOC.Head Bolt = M6*25Lg = 3 Nos
SOC.Head Bolt = M10*25Lg =12 Nos
SOC.HEAD BOLT = M10*80Lg = 1 No
The material used in this are STD materials
FIGURE 4.5: SOCKET HEAD BOLT
-
47
4.4.10. DOWEL PIN
A dowel is a solid cylindrical rod, usually made of wood,
plastic,
or metal. In its original manufactured form, a dowel is called a
dowel rod.
Dowel rods are often cut into short lengths called dowel pins.
Dowels are
employed in numerous, diverse applications including as axles
in
toys, detents(e.g., in gymnastics grips), structural
reinforcements in cabinet
making, and supports for tiered wedding cakes. Other uses
include:
As furniture shelf supports
As moveable game pieces (i.e., pegs)
As supports for hanging items such as clothing, key rings,
tools, toilet
roll dispensers and picture frames
To precisely align two objects in a dowel joint: a hole is bored
in both
objects and the dowel pin is inserted into the aligned holes
As a core to wrap cable or textiles around
DOWEL PIN (OD * Lg) = 10*110
The material used in these are STD materials.
FIGURE 4.6:DOWEL PINS
-
48
4.4.11 SLEEVE
Sleeves may be placed and hydraulic operated clamps mounted on
the
upper end of each of the bucks for holding the cuffs of the
sleeves during a
pressing operation. Each clamp includes a head or block having a
vertical
clamping surface, a pneumatic cylinder mounted within the block
having its
piston rod extending generally perpendicularly outwardly through
the surface,
and a T-clamp connected to the rod for movement toward and away
from the
surface upon actuation of the cylinder. A pneumatic control
circuit controls
operation of the cylinders. A hold down device located between
the bucks
applies tension to the sleeves of a rivet during a pressing
operation .
FIGURE 4.7: SLEEVES
-
49
4.4.12 INSERT OF TOOL ( TOP & BOTTOM )
A Insert tool is generally refers to any cutting or punching
tool where the cutting edge consists of a separate piece of
material,
either brazed, welded or clamped on to a separate body.
TOP INSERT (OD * LG) = 19*13 in mm = 24 Nos
BOTTOM INSERT (OD * LG) = 16*17 in mm = 24 Nos
FIGURE 4.8: TOOL INSERTERS
4.4.13 PUNCH( TOP & BOTTOM )
A punch press is a type of machine press used to cut holes
in
material. It can be small and manually operated and hold one
simple die set, or
be very large, CNC operated, with a multi-station turret and
hold a much larger
and complex die set. The tool is placed slightly above the
bottom bed plate by
providing two parallel blocks accurately ground to the same
size. This is a
necessary action since many tools, scrap (cut pieces which are a
waste) is
-
50
discharged through the bottom element of the tool, not
necessarily in the centre
of the tool. the scrap or the blank ( the required portion )
come out from the die
at different places . These have to be taken out horizontally
from between the
parallels placed. Otherwise they get accumulated inside the tool
itself and cause
severe damage to the tool.
TOP PUNCH (OD* Lg) =16*71 = 24 Nos
BOTTOM PUNCH (OD* Lg) = 16*65 =24 Nos
FIGURE 4.9: FIXED PUNCH
4.4.14 SPRINGS
Damping is an influence within or upon an oscillatory system
that
has the effect of reducing, restricting or preventing its
oscillations. In physical
systems, damping is produced by processes that dissipate the
energy stored in
the oscillation. Examples include Viscous drag in mechanical
systems, resistance in electronic, and absorption and scattering
of light in optical
oscillators. Damping not based on energy loss can be important
in other
oscillating systems such as those that occur in biological
systems.
The damping of a system can be described as being one of the
following:
Overdamped: The system returns (exponentially decays) to
equilibrium
without oscillating.
-
51
Critically damped: The system returns to equilibrium as quickly
as possible
without oscillating.
Underdamped: The system oscillates (at reduced frequency
compared to
the undamped case) with the amplitude gradually decreasing to
zero.
Undamped The system oscillates at its natural resonant frequency
(o).
For linear Damping
The force may be related to the velocity by
This force may be used as an approximation to the friction
caused
by drag and may be realized, for instance, using a dashpot.
(This device
uses the viscous drag of a fluid, such as oil, to provide a
resistance that is
related linearly to velocity.) Even when friction is related to
, if the
velocity is restricted to a small range, then this non-linear
effect may be
small. In such a situation, a linearizied friction coefficient
may be
determined which produces little error.
When including a restoring force (such as due to a spring) that
is
proportional to the displacement and in the opposite direction,
and by
setting the sum of these two forces equal to the mass of the
object times
its acceleration creates a second-order differential equation
whose terms
can be rearranged into the following form:
where 0 is the undamped angular frequency of the oscillator and
is a
constant called the damping ratio. This equation is valid for
many
different oscillating systems, but with different formulas for
the damping
ratio and the undamped angular frequency.
-
52
The value of the damping ratio determines the behaviour of the
system
such that = 1 corresponds to being critically damped with larger
values
being overdamped and smaller values being underdamped. If = 0,
the
system is undamped.
SPRING(OD*TH*Lg) = 30*4*55 = 24Nos
FIGURE 4.10 : SPRING ASSEMBLY
4.5 MACHINES INVOLVE TO FABRICATE JIG AND FIXTURE
CONVENTIONAL MILLING MACHINE
LATHE MACHINE
DRILLING MACHINE
BANDSAW MACHINE
CNC MILLING MACHINE (3-AXIS)
CNC MILLING MACHINE (5-AXIS)
-
53
4.6 TOOLING DETAILS
Tooling details are the overall construction characteristics and
special
features incorporated into the jig or fixture. Permanent work
holders are
designed and built to last longer than temporary workholders.
So, permanent
jigs and fixtures usually contain more-elaborate parts and
features than
temporary workholders.There are several other differences
between permanent
and temporary workholders in this area. These include the type
and complexity
of the individual tooling elements, the extent of secondary
machining and
finishing operations on the tool, the tool-design process, and
the amount of
detail in the workholder drawings. Since the elements for
modular workholders
are usually part of a complete set, or system, only rarely will
additional custom
components need to be made.Permanent workholders contain
different
commercial tooling components based on expected tool usage.
Permanent jigs
intended for a high-volume drilling operation, for example,
often use a
renewable bushing and liner bushing together. A throwaway jig
for a smaller
production run often uses a simple press-fit bushing.The
secondary operations
normally associated with tooling include hardening, grinding,
and similar
operations to finish the workholder. Usually, permanent
workholders are
hardened and ground to assure their accuracy over a long
production run. Since
they are intended only for short production runs, throwaway jigs
and fixtures do
not require these operations. Another secondary operation
frequently performed
on permanent tools, but not temporary tools, is applying a
protective finish,
such as black oxide, chrome plating, or enamel paint.In
designing a permanent
workholder, the designer often makes detailed engineering
drawings to show
the toolroom exactly what must be done to build the workholder.
With
temporary workholders, the design drawings are often sent to the
toolroom as
simple freehand sketches.
-
54
Permanent tools are normally designed for long-term use. This
being the
case, the drawings and engineering data for the permanent jig or
fixture then
become a permanent record. With modular workholders, the
designer may
either construct drawings or specify building the workholder
directly around the
part. Here only a parts list and photographs or video tape are
kept as a
permanent record.
Certain workholding applications require special fixture
characteristics.
For example, a particularly corrosive environment may require
stainless steel
components and clamps to deliver a satisfactory life cycle. In
other cases,
variable workpiece dimensions, as in a casting, necessitate
clamping devices
which can compensate for these variations. Appearance of a
finished part might
require the use of nylon, plastic, or rubber contact points to
protect the part.
Similarly, the selection of tooling details can enhance the
productivity of
some permanent tools. For example, utilizing small hydraulic
clamps may allow
loading many parts on a workholder due to the compactness of the
design. This
would enhance productivity by reducing load/unload time as a
percentage of
total cycle time. Duplicate fixtures are sometimes justified for
machining
centers because they allow loading of parts on one pallet during
the machining
cycle on the other pallet.
4.7 TOOLING OPERATION
The performance of any workholder is critical to the complete
usefulness
of the tool. If the workholder cannot perform the functions
desired in the
manner intended, it is completely useless, regardless of the
cost or the extent of
the detail. As the performance of a permanent, modular, or
general-purpose
workholder is considered, several factors about the machine
tools must be
known. These factors include the type, size, and number of
machine tools
-
55
needed for the intended operations.Work holders are sometimes
designed to
serve multiple functions. For example, it is possible to have a
work holder that
acts both as a drill jig and a milling fixture. These tools are
called combination
tools or multiple-function work holders.Despite the work holder
design or the
size of the production run, every jig or fixture must meet
certain criteria to be
useful. These criteria include accuracy, durability, and safety.
Accuracy, with
regard to jigs and fixtures, is the ability of a work holder to
produce the desired
result, within the required limits and specifications, part
after part, throughout
the production run.
To perform to this minimum level of accuracy, the work holder
must also
be durable. So, the jig or fixture must be designed and built to
maintain the
required accuracy throughout the expected part production. If
part production is
continuous, year after year, the jig or fixture must be more
durable than is
necessary for only one production run. The final consideration,
safety, is
actually the most important. No matter how good the design or
construction, or
how well it produces the desired accuracy, if the work holder is
not safe, it is
useless. Safety is a primary concern in the design of any
workholder.Safety, as
well as speed and reliability of part loading, can often be
improved by the use of
power clamping, either pneumatic or hydraulic. Once set, power
clamps will
repeatedly clamp with the identical force. This is not always
true with manual
clamps, which depend on operator diligence for the proper
application of
clamping force. In addition, power-clamping systems can have
interlocks to the
machine control which will shut the machine down if the system
loses power
a clear safety advantage for both operator and machine tool.
4.8 APPLICATIONS FOR JIGS AND FIXTURES
Typically, the jigs and fixtures found in a machine shop are
for
machining operations. Other operations, however, such as
assembly, inspection,
-
56
testing, and layout, are also areas where workholding devices
are well suited.
Figure 1-7 shows a list of the more-common classifications and
applications of
jigs and fixtures used for manufacturing. There are many
distinct variations
within each general classification, and many workholders are
actually
combinations of two or more of the classifications shown.
4.8.1 EXTERNAL-MACHINING APPLICATIONS:
Flat-Surface Machining
Milling fixtures
Surface-grinding fixtures
Planing fixtures
Shaping fixtures
Cylindrical-Surface Machining
Lathe fixtures
Cylindrical-grinding fixtures
Irregular-Surface Machining
Band-sawing fixtures
External-broaching fixtures
4.8.2 INTERNAL-MACHINING APPLICATIONS:
Cylindrical- and Irregular-Hole Machining
Drill jigs
Boring jigs
Electrical-discharge-machining fixtures
Punching fixtures
Internal-broaching fixtures
-
57
4.8.3 NON-MACHINING APPLICATIONS:
Assembly
Welding fixtures
Mechanical-assembly fixtures
(Riveting, stapling, stitching, pinning, etc.)
Soldering fixtures
Inspection
Mechanical-inspection fixtures
Optical-inspection fixtures
Electronic-inspection fixtures
Finishing
Painting fixtures
Plating fixtures
Polishing fixtures
Lapping fixtures
Honing fixtures
Miscellaneous
Layout templates
Testing fixtures
Heat-treating fixtures
-
58
4.9 DESIGNING RESULT
The designing of the tool are given below
FIGURE 4.11 GANG RIVETING FIXTURE
BOTTOM DIE TOP DIE
-
59
`
FIGURE 4.12 VARIOUS PARTS
SHANK CENTRE BUNK
BOTTOM
PUNCH
TOP
PUNCH
BOTTOM
INSERT
TOP
INSERT
GUIDE PILLAR-I
GUIDE PILLAR - II
GUIDE BUSH-I
GUIDE BUSH -II
SLEEVE
-
60
FIGURE 4.13 BOTTOM PUNCH HOLDER
FIGURE 4.14 BOTTOM STRIPPER PLATE
-
61
FIGURE 4.15 BOTTOM PLATE
FIGURE 4.16 TOP PLATE
-
62
FIGURE 4.17 TOP STRIPPER PLATE
FIGURE 4.18 TOP PUNCH HOLDER
-
63
CHAPTER 5
RESULT AND DISCUSSION
5.1RESULT
The designed components which tend to eradicate the man
power,
cycle time and the easy flow of the process. The designing of
the gang riveting
tool which has little complex and involved more precision to
develop the design
and implement in the organisation. The designing of the tool
which are
discussed below.
5.2 COMPONENTS LIST
S.NO PART NAME NO.OF
PARTS
MATERIAL
1 BOTTOM PLATE 1 MS
2 BOTTOM PAD PLATE 1 MS
3 BOTTOM PUNCH HOLDER 1 OHNS
4 BOTTOM STRIPPER PLATE 1 MS
5 TOP STRIPPER PLATE 1 MS
6 TOP PUNCH HOLDER 1 OHNS
7 TOP PAD PLATES 1 MS
8 TOP PLATE 1 MS
9 SHANK 1 MS
10 CENTRE BUNK 1 OHNS
11 TOP PUNCH 24 D2
12 BOTTOM PUNCH 24 D2
13 CAP SCREW 24 STD
14 BOTTOM INSERT 24 OHNS
15 TOP INSERT 24 OHNS
-
64
16 GUIDE BUSH - I 1 OHNS
17 GUIDE BUSH II 1 OHNS
18 GUIDE PILLAR I 1 OHNS
19 GUIDE PILLAR- II 1 OHNS
20 DOWEL PIN 4 STD
21 SOC.HEAD BOLT
M10* 55Lg
24 STD
22 SOC.HEAD BOLT
M6 *25 Lg
6 STD
23 SPRING 24 STD
24 SOC.HEAD BOLT
M10*80Lg
1 STD
25 SLEEVE 24 MS
TABLE 6.1 LIST OF COMPONENTS
5.3 DISCUSSION
The gang riveting fixture which consist of the following
measures
Dimensions of Facing plate
Inner PCD = 192 mm
Outer PCD = 247.5 mm
Thickness = 3.5 mm
Rivet hole Diameter = 11.3 mm
Rivet diameter = 4.8515 mm
Rivet height = 5.6722 mm
Rivet head diameter = 9.15\9.65 mm
ANGLE
Angle between riveting hole = 18
-
65
Locating pins
PCD = 219.5mm
Flaring diameter = Rivet dia * 1.25 mm
= 4.8515*1.25 = 6.064375 mm
Load capacity = p=F/A ,
F= normal force, A= surface of contact
It can withstand with a maximum load of 2000kPa to maintain the
flaring
diameter without any damage to the plate.
5.4TOOLING:
Provide two non-plated thru tooling holes, dia 0.125
+0.003/-0.003 as far
apart as practical.
Tooling hole to tooling pin tolerance +0.000/-0.003.
A 0.050 annular area around tooling holes must be clear of
components
and test pads.
-
66
5.4 MERITS & DEMERITES OVER RIVETING MACHINE
5.4.1MERITS
It reduces the operation fatigue.
It increases the cycle time.
Quality of the component increased.
Increased productivity.
More secure for workers than the riveting machine.
5.4.2DEMERITS
It consumes time to set the rivets .
Proper maintance and survilance should be maintained.
Mis-alignment of tool cause damages to the plate.
-
67
CHAPTER - 6
CONCLUSION
6.1 CONCLUSION
The objective of the project is to design the gang riveting
fixture, to
reduce the operation which consumes repetitive action to the
assembly of the
driven clutch plate. From the state of scratch path is being
designed with the
help of AutoCAD. The work is carried out with the basis of step
by step
calculation at each level to the complete designing of gang
riveting fixture.The
approach of the project could be a part of the work towards the
improvement of
production in your organisation.
The maximum load that can be applied for the tool is
2000Kpa.
6.1 RECOMMENDATION
With the introducing of this tool that tends to increase the
production
level increase with the high tolerance and accuracy. This will
be more precision
in accuracy and the inspection .
-
68
6.3 REFERENCE
MECHANICAL DESIGN ,2ND EDITION BY PETER R.N CHILDS
B.Sc(Hons)
MECHANICAL ASSEMBLIES BY DANIEL E. WHITNEY..
AUTOCAD2010-APROBLEM SLOVING APPROACH.
Design of final riveting tool by the organisation..
-
69