KYAMBOGO
UNIVERSITY
FACULTY OF ENGINEERING
DEPARTMENT OF MECHANICAL AND PRODUCTION ENGINEERING
BACHELOR OF ENGINEERING IN MECHANICAL AND
MANUFACTURING ENGINEERING
FINAL YEAR PROJECT REPORT
DESIGN OF A LOW COST PNEUMATIC OPERATED SHEARING
MACHINE
BY
BAMUKUNDA EDMOND
13/U/9079/EME/PE
SUPERVISOR: MR. EROJU MOSES
A REPORT DOCUMENT ON THE DESIGN OF A LOW COST PNEUMATIC OPERATED
SHEARING MACHINE FOR CONTRACTORS SUN FRONTIERS SUBMITTED TO THE
MECHANICAL AND PRODUCTION DEPARTMENT AS PARTIAL FULFILLMENT OF A
BACHELORS DEGREE IN MECHANICAL AND MANUFACTURING ENGINEERING.
AUGUST 2018
DECLARATION
I BAMUKUNDA EDMOND hereby declare that this research project is my own work and it
has never been submitted to any institution for any reward.
Signature:………………………………………..
Date:……………………………………………..
i
APPROVAL
This is to certify that this work was carried out under strict supervision and has been approved
for submission to the Department of Mechanical and Production Engineering of Kyambogo
University in partial fulfillment of the requirement of the award of a Bachelor of Engineering in
Mechanical and Manufacturing Engineering.
Supervisor Name: MR. EROJU MOSES
Signature:……………………………………………………………..
Date:…………………………………………………………………..
ii
DEDICATION
I humbly dedicate this project to all people that have always assisted me in my study time during
which I was doing this work, particularly my parents who supported me financially.
iii
ACKNOWLEDGEMENT
I am overwhelmingly thankful to the Almighty for His abundant providence all through the years
of my life.
My sincere appreciation goes towards my supervisor Mr. Eroju Moses for the guidance,
assistance and advice during this period.
To my friends for the consistent support, encouragement and words of wisdom. God bless you.
Finally, my heartfelt thanks go to my family members, most especially my parents for the
financial, spiritual and moral support you have rendered to me during this period. May God
reward you abundantly.
iv
TABLE OF CONTENTS
DECLARATION ............................................................................................................................. i
APPROVAL.................................................................................................................................... ii
DEDICATION ............................................................................................................................... iii
ACKNOWLEDGEMENT ............................................................................................................. iv
LIST OF FIGURES ..................................................................................................................... viii
LIST OF TABLES ....................................................................................................................... viii
ABSTRACT ................................................................................................................................... ix
CHAPTER ONE ........................................................................................................................... 1
INTRODUCTION ......................................................................................................................... 1
1.1 Background ........................................................................................................................... 1
1.2
Problem Statement ........................................................................................................... 3
1.3.
Objectives ......................................................................................................................... 4
1.3.1. General objective .......................................................................................................... 4
1.3.2. Specific objectives ........................................................................................................ 4
1.4 Research questions................................................................................................................ 4
1.5 Scope..................................................................................................................................... 4
1.6 Justification ........................................................................................................................... 4
1.7 Significance .......................................................................................................................... 4
1.8
Limitations ....................................................................................................................... 5
1.9 Delimitations......................................................................................................................... 5
CHAPTER TWO .......................................................................................................................... 6
LITERATURE REVIEW............................................................................................................. 6
2.1 Introduction........................................................................................................................... 6
2.2 Shearing Machines ................................................................................................................ 8
2.2.1 Pneumatically operated: ................................................................................................ 9
v
2.2.2 Hydraulically operated: - ............................................................................................... 9
2.2.3 Rack and pinion operated: -........................................................................................... 9
2.2.4 Spring operated: - .......................................................................................................... 9
CHAPTER THREE .................................................................................................................... 10
METHODOLOGY...................................................................................................................... 10
3.1
Introduction .................................................................................................................... 10
3.2
Research design .............................................................................................................. 10
3.3
Types of data .................................................................................................................. 10
3.4
Sources of data ............................................................................................................... 10
3.5
Data collection techniques ............................................................................................. 10
3.5.1
Observation ............................................................................................................. 10
3.5.2
Internet search ......................................................................................................... 10
3.5.3
Field survey............................................................................................................. 11
3.6 Methodology table .............................................................................................................. 11
3.7 Data analysis ....................................................................................................................... 11
CHAPTER FOUR ....................................................................................................................... 12
DATA PRESENTATION, ANALYSIS AND DISCUSSION OF FINDINGS ...................... 12
4.1 Introduction......................................................................................................................... 12
4.2 EXISTING SHEARING MACHINE MECHANISMS OF OPERATION ........................ 12
4.2.1 Pneumatically operated: .............................................................................................. 12
4.2.2 Hydraulically operated: - ............................................................................................. 12
4.2.3 Rack and pinion operated: -......................................................................................... 12
4.2.4 Spring operated: - ........................................................................................................ 13
4.3 COMPONENTS, DESIGN PARAMETERS AND LAYOUT OF THE LOW COST
PNEUMATIC OPERATED SHEARING MACHINE ............................................................ 13
4.3.1 CONSTRUCTION ...................................................................................................... 13
vi
4.3.2 DESIGN ...................................................................................................................... 14
4.3.3 General Layout ............................................................................................................ 20
4.4 COST ANALYSIS ............................................................................................................. 20
CHAPTER FIVE......................................................................................................................... 22
CONCLUSION AND RECOMMENDATIONS ...................................................................... 22
5.1 CONCLUSION................................................................................................................... 22
5.2 RECOMMENDATIONS .................................................................................................... 22
REFERENCES.............................................................................................................................. 23
vii
LIST OF FIGURES
Figure 1: pneumatic operated shearing machine ............................................................................. 8
Figure 2: Concept Image for project ............................................................................................. 13
Figure 3: base frame layout ........................................................................................................... 18
Figure 4: shearing blades layout ................................................................................................... 19
Figure 5: general layout of pneumatic machine ............................................................................ 20
LIST OF TABLES
Table 1: Methodology Table ......................................................................................................... 11
Table 2: bill of materials ............................................................................................................... 20
viii
ABSTRACT
There is so much high competition of industries in Uganda towards producing best quality items
required by clients. Yet companies need to produce items in the shortest time possible, in the
highest quantities as required and in the best standard as a measure of accuracy to international
standards practices. Most companies use advanced machines which apply mechatronic
synchronization but their maintenance is rather high and even the competences of the workers on
these machines are low.
There is no statistical evidence that to produce quality sheet metal items, a company needs
advanced machines. It is rather low cost machines that sustain small and medium size companies
in production. What is important is “how well” and “how easy” the machine can be operated.
The technology of pneumatics has gained tremendous importance in the field of automation from
old fashioned timber works, machine shops and space robots. Certain characterizes of air have
made this medium quite suitable for use in modern manufacturing and production industries. It is
therefore important that technicians and engineers should have knowledge on pneumatic systems
air operated valves accessories. Pneumatic system consists of a compressor plant, pipelines,
control valves, pneumatic cylinder, connecting links, control system and drive members. The air
is compressed in an air compressor and from the compressor plant, the flow media is transmitted
to the pneumatic cylinder through a well-laid pipeline system. So, keeping in mind about the
importance of pneumatic system, introducing a pneumatic sheet metal cutting. By the use of
pneumatic shearing technique, it can reduce human effort in cutting sheet metal and it is a time
saving process. The design is particularly suited to applications where the working space is
constrained. Pneumatic shearing machines are useful when materials need to be cut in hazardous
areas such as oil & gas refineries, chemical factories or oilrigs as well as dusty and wet
environments where electric tools are not effective.
Keywords: Pneumatic cylinder, connecting links Pneumatic shearing machines, time and cost
saving.
The shearing machine is of great importance in the sheet metal industry in the present times. The
machine is used for straight cutting with a wide variety of applications. In some industries
manual sheet cutters are used, which require a lot of the human effort. The machine should be
easy to operate and maintain, thus the idea to develop the pneumatic shearing machine.
ix
CHAPTER ONE
INTRODUCTION
1.1 Background
In many developed industries today, the automatic sheet shearing machines are widely used as
opposed to the earlier the process which was carried out manually. The manual process was time
consuming as well as the output of machine was very less. The main aim of the project is to
improve the efficiency of the required output and to increase the production, and give better
quality output.
In this project I used pneumatic system, which involves the use of pressurized gases to do work
in science and technology.
Pneumatic devices are used in many industrial applications. Generally appropriate for
applications involving less force than hydraulic applications, and typically less expensive than
electric applications, most pneumatic devices are designed to use clean dry air as an energy
source (S.R.Mujumdar, 1993). The actuator then converts that compressed air into mechanical
motion. Pneumatic cylinders are generally less expensive than hydraulic or electric cylinders of
similar size and capacity.
In this operation the pneumatic system is installed on the C-frame body with required
attachment. And pneumatic cylinder is placed on C-frame body vertically with front flange
mounting (S.R. Mujumdar, 1985).
Sheet metal is simply a metal formed into thin and flat pieces (E. Paul. Degarmo 2003). It is one
of the fundamental forms used in metal working and can be cut and bent into a variety of
different shapes.
Very many objects are made of sheet metal. Thicknesses can vary significantly, although
extremely thin thicknesses are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are
considered plate. The thickness of the sheet metal is called its gauge. Commonly used steel sheet
metal ranges from 30 gauge to about 8 gauge. The larger the gauge number, the thinner the
metal. Gauge is measured in ferrous (iron based) metals while nonferrous metals such as
aluminum or copper are designated differently; i.e., Copper is measured in thickness by Ounce.
There are many different metals that can be made into sheet metal, such as aluminum, brass,
1
copper, steel, tin, nickel and titanium. For decorative uses, important sheet metals include silver,
gold and platinum (platinum sheet metal is also utilized as a catalyst.) Sheet metal also has
applications in car bodies, airplane wings, medical tables, roofs for buildings (Architectural) and
many other things. Sheet metal of iron and other materials with high magnetic permeability, also
known as laminated steel cores, has applications in transformers and electric machines.
There are three primary procedures in Layout
1. Parallel
2. Radial
3. Triangulation
Cutting processes are those in which a piece of sheet metal is separated by applying a great
enough force to cause the material to fail. The most common cutting processes are performed by
applying a shear force, and are therefore sometimes referred to as shearing processes. When a
great enough shearing force is applied, the shear stress in the material will exceed the ultimate
shear strength and the material will fail and separate at the cut location. Two tools, one above
and one below the sheet apply this shearing force. Whether these tools are a punch and die or
upper and lower blades, the tool above the sheet delivers a quick downward blow to the sheet
metal that rests over the lower tool. A small clearance is present between the edges of the upper
and lower tools, which facilitates the fracture of the material. The size of this clearance is
typically 2-10% of the material thickness and depends upon several factors, such as the specific
shearing process, material, and sheet thickness. The effects of shearing on the material change as
the cut progresses and are visible on the edge of the sheared material. When the punch or blade
influences the sheet, the clearance between the tools allows the sheet to plastically deform and
“rollover” the edge. Finally, the shear stress is too great and the material fractures at an angle
with a small burr formed at the edge. The height of these portions of the cut depends on several
Pneumatic Shearing Machine: Pneumatics is the branch of technology, which deals with the
study and usage of pressurized gas to affect mechanical motion. Pneumatic sheet metal machine
is a cutting machine tool designed to cut metal by applying pneumatic pressure. My project deals
with fabrication of light weight pneumatic shearing machine specially designed to quickly and
safely cut through thin and soft metals. This machine can be easily designed using standard
cylinders & other components like release/port/direction control valves, flow regulator, piston
2
and air compressor. Controlling of this machine is as easy as it is simple ON - OFF type.
Because of compressible air, the equipment is less likely to be damaged by shock. There are
numerous types of cutting machines available in engineering field, but we are interested to
introduce low cost pneumatic system in sheet metal cutting machine. The design is particularly
suited to applications where the working space is constrained, Pneumatic shearing machines are
useful when materials need to be cut in hazardous areas such as oil & gas refineries, chemical
factories or oil rigs as well as dusty and wet environments where electric tools are not effective.
The machine is exclusively intended for mass production and they represent the faster and more
efficient way to cut a metal. The operation of the unit is simplified to a few simple operations
involving a cylinder block and factors, including the sharpness of the tools and the clearance
between the tools.
There are numerous types of cutting machines in Engineering field. The main function of
Pneumatic shearing machine is to cut thin and soft metals by pneumatic power.
Pneumatic devices are used in many industrial applications. Generally appropriate for
applications involving less force than hydraulic applications, and typically less expensive than
electric applications, most pneumatic devices are designed to use clean dry air as an energy
source. The actuator then converts that compressed air into mechanical motion. Pneumatic
cylinders are generally less expensive than hydraulic or electric cylinders of similar size and
capacity.
1.2
Problem Statement
The shearing machine used at Contractors Sun Frontiers is manually operated and requires a lot
of manpower to effect its operation yet the mechanically operated shearing machines in the
market are costly hence beyond the reach of Contractors Sun Frontiers. The purpose of this study
therefore is to design a low cost pneumatic shearing machine.
3
1.3.
Objectives
1.3.1. General objective
•
To design a low cost pneumatic operated shearing machine.
1.3.2. Specific objectives

To study the existing shearing machine mechanisms of operation.

To determine components and design parameters of the low cost pneumatic shearing
machine.

To size, select and develop the layout of the low cost pneumatic shearing machine.

To carry out cost analysis of the low cost pneumatic shearing machine.
1.4 Research questions
a)
What are the existing shearing machine mechanisms of operation?
b)
What are the design parameters of the low cost pneumatic operated shearing machine?
c)
What is the possible cost of designing the low cost pneumatic operated shearing
machine?
1.5 Scope
Context Scope
The research is limited to design a pneumatic operated shearing machine of:
Mild Steel bars for base frame.
35C8 material for shearing blades.
1.6 Justification

The need to reduce on the excessive human effort required in shearing operation.

The need to reduce the working time that lowers the production rate.

The need to improve income through increased productivity.
1.7 Significance
The project will give a higher effectiveness, ease of operation, safety of machine operator, high
durability and reliability, and high adaptability to the harsh environment.
4
1.8
Limitations

Insufficient funds for secretarial and communication services.

Weather changes characterized by very hot conditions and heavy rains.

Language barrier during interviews with workers as some were illiterate respondents.

Transport problems.
1.9 Delimitations

Language barrier was solved by getting nearest interpreters.

Too much sunshine and heavy rains were solved by getting umbrellas and cold weather
coats and jackets.

Insufficient funds were solved by cutting down costs as well as asking for contributions
from my parents and friends.
5
CHAPTER TWO
LITERATURE REVIEW
2.1 Introduction
The word “pneuma‟ comes from Greek and means breather wind. The word pneumatics is the
study of air movement and its phenomena is derived from the word pneuma. Today pneumatics
is mainly understood to means the application of air as a working medium in industry especially
to driving and controlling of machines and equipment. Pneumatics has for some considerable
time between used for carrying out the simplest mechanical tasks. In times that are more recent it
is playing more important role in the development of pneumatic technology for automation.
Pneumatic systems operate on a supply of compressed air that must be made available in
sufficient quantity and at a pressure to suit the capacity of the system. When the pneumatic
system is being adopted for the first time, however it wills indeed the necessary deal with the
question of compressed air supply. The key part of any facility for supply of compressed air is by
means using reciprocating compressor. A compressor is a machine that takes in air, gas at a
certain pressure and delivers the air at a high pressure. Compressor capacity is the actual quantity
of air compressed and delivered and the volume expressed is that of the air at intake conditions
namely at atmosphere pressure and normal ambient temperature. Robert Boyle first investigated
the compressibility of the air in 1962 and he found that the product of pressure and volume of a
particular quantity of gas is inversely proportional. It is written as PV = C (or) PıVı = P2V2 In
this equation the pressure is the absolute pressured which is about 14.7 Psi and is of courage
capable of maintaining a column of mercury, nearly 30 inches high in an ordinary barometer.
Any gas can be used in pneumatic system but air is the mostly used system now a days.
Selection of Pneumatics: Mechanization is broadly defined as the replacement of manual effort
by mechanical power. Pneumatic is an attractive medium for low cost mechanization particularly
for sequential (or) repetitive operations. Many factories and plants already have a compressed air
system, which is capable of providing the power (or) energy requirements and the control system
(although equally pneumatic control systems may be economic and can be advantageously
applied to other forms of power). The main advantage of an all-pneumatic system are usually
economic and simplicity the latter reducing maintenance to a low level. It can also have
outstanding advantages in terms of safety.
6
In dentistry applications, pneumatic drills are lighter, faster and simpler than an electric drill of
the same power rating, because the prime mover, the compressor, is separate from the drill and
pumped air is capable of rotating the drill bit at extremely high rpm. Pneumatic transfer systems
are employed in many industries to move powders and pellets.
Pneumatic devices are also used where electric motors cannot be used for safety reasons, such as
mining applications where rock drills are powered by air motors to preclude the need for electric
motors deep in the mine where explosive gases may be present.
Pneumatic systems operate on a supply of compressed air, which must be made available in
sufficient quantity and at a pressure to suit the capacity of the system. The key part of any
facility for supply of compressed air is by means using reciprocating compressor. A compressor
is a machine that takes in air, gas at a certain pressure and delivers the air at a high pressure.
Compressor capacity is the actual quantity of air compressed and delivered and the volume
expressed is that of the air at intake conditions namely at atmosphere pressure and normal
ambient temperature. Clean condition of the suction air is one of the factors, which decides the
life of a compressor. Warm and moist suction air will result in increased precipitation of
condense from the compressed air. Compressor may be classified in two general types. 1.
Positive displacement compressor. 2. Turbo compressor. Positive displacement compressors are
most frequently employed for compressed air plant, have proved highly successful, and supply
air for pneumatic control application. The types of positive compressor are
1. Reciprocating type compressor
2. Rotary type compressor.
Turbo compressors are employed where large capacity of air required at low discharge pressures.
They cannot attain pressure necessary for pneumatic control application unless built in
multistage designs and are seldom encountered in pneumatic service
In shearing or cutting operation, a blade descends upon the metal, the pressure exerted by the
blade first cause the plastic deformation of the metal. Since the clearance between the two blades
is very small, the plastic deformation takes place in a localized area and the metal adjacent to the
cutting edges of the blade edges becomes highly stressed, which causes the fracture to start on
7
both sides of the sheet as the deformation progresses and the sheet is sheared.
Figure 1: pneumatic operated shearing machine
2.2 Shearing Machines
Types of shearing Machine:
1)
Pneumatically operated
2)
Hydraulically operated
3)
Rack and pinion operated
4)
Spring operated
Brief description of all the types is as follows.
8
2.2.1 Pneumatically operated:
Here the advancement of the header is carried out in the upward and the downward direction
using the pneumatic double acting piston and cylinder unit arrangement along with the foot
operated direction control valve. In this type of machine high pressure air is used as the working
fluid for the transfer of power and the motion.
2.2.2 Hydraulically operated: Here the lowering and raising of the header is carried over using the hydraulic piston and
cylinder arrangement. To actuate the piston and cylinder, the oil is allowed to enter the cylinder
from front or the back side of the piston. But the oil is comparatively costlier and its leakage may
cause so many problems.
2.2.3 Rack and pinion operated: Here the lowering and the raising of the header are carried out manually using the rack and
pinion arrangement. In this case the required pressure is applied manually using direct hand
pressure on the rack using pinion and lever arrangement. Since the machine is robust and
requires large pressure, hence it is not suitable.
2.2.4 Spring operated: The working of spring operated machine is similar to the rack and pinion operated machine but
differs from it in construction. Here the lowering and the raising of the heating handle are carried
out manually and it requires too much pressure for its operation and also there is possibility of
having damage to the work piece if not handled carefully.
9
CHAPTER THREE
METHODOLOGY
3.1
Introduction
This chapter presents a detailed description of the selected research design. It describes in detail
what was done and how it was done.
3.2
Research design
The study contained both qualitative and quantitative designs approaches. This enabled the study
to stimulate explanations on use of shearing machine and its possible advancements.
The qualitative method involved
3.3
Types of data
The data collected was either primary or secondary data. Primary data being that which was
captured for the first time and secondary data that which was captured from other sources but
accessed for another problem.
This research mainly used secondary data obtained by carrying out research on the design
specifications of various pneumatic shearing machines. In addition, primary data obtained from
the users of various shearing machines helped in design of the project.
3.4
Sources of data
The sources of data included the workshop users who have operated shearing operations, and
also from manufacturers manuals.
3.5
Data collection techniques
3.5.1
Observation
This involved watching, listening and recording.
3.5.2
Internet search
Relevant websites about shearing operations were visited to collect information related to
existing shearing machines.
10
3.5.3
Field survey
This was used to study shearing operations. This also involved finding out costs of the materials
from the field/market.
3.6 Methodology table
Table 1: Methodology Table
S/N
1
2
Specific objectives
Methods
To study the existing shearing Observations
machine mechanisms of operation.
Remarks
This
involved
watching,
listening
and recording
To size, select components, develop Internet and library This involved making
search
comparisons
with
design parameters and layout for the
available
shearing
machines.
low cost pneumatic operated shearing
machine.
3
To carry out cost analysis of the low Field survey
cost
pneumatic operated shearing
machine.
This involved finding
out costs of the
materials from the
field/market.
3.7 Data analysis
The data was analysed basing on whether it was qualitative or quantitative. A descriptive
summary including frequency distributions and statistical analysis was made. The data collected
was interpreted and discussed in line with research objectives and literature review to attach
meaning to the figures obtained
11
CHAPTER FOUR
DATA PRESENTATION, ANALYSIS AND DISCUSSION OF FINDINGS
4.1 Introduction
This chapter contains the findings and the results of the research carried out. It gives a detailed
description and discussion of the data acquired during the research in line with the specific
objectives and therefore conclusions in the next chapter were drawn accordingly.
Through Observations:
4.2 EXISTING SHEARING MACHINE MECHANISMS OF OPERATION
4.2.1 Pneumatically operated:
Here the advancement of the header is carried out in the upward and the downward direction
using the pneumatic double acting piston and cylinder unit arrangement along with the foot
operated direction control valve. In this type of machine high pressure air is used as the working
fluid for the transfer of power and the motion.
4.2.2 Hydraulically operated: Here the lowering and raising of the header is carried over using the hydraulic piston and
cylinder arrangement. To actuate the piston and cylinder, the oil is allowed to enter the cylinder
from front or the back side of the piston. But the oil is comparatively costlier and its leakage may
cause so many problems.
4.2.3 Rack and pinion operated: Here the lowering and the raising of the header are carried out manually using the rack and
pinion arrangement. In this case the required pressure is applied manually using direct hand
pressure on the rack using pinion and lever arrangement. Since the machine is robust and
requires large pressure, hence it is not suitable.
12
4.2.4 Spring operated: The working of spring operated machine is similar to the rack and pinion operated machine but
differs from it in construction. Here the lowering and the raising of the heating handle are carried
out manually and it requires too much pressure for its operation and also there is possibility of
having damage to the work piece if not handled carefully.
Through Internet and library search:
4.3 COMPONENTS, DESIGN PARAMETERS AND LAYOUT OF THE LOW COST
PNEUMATIC OPERATED SHEARING MACHINE
Figure 2: Concept Image for project
4.3.1 CONSTRUCTION
Raw Material Used
 Mild Steel bars for base frame.
 35C8 material for shearing blades.
 Cylinder fittings like fork end, base plates, support links.
 Angle section for blade fitting.
 Connecting link.
 Blade link.
13
Ready Items Used
 Pneumatic double acting cylinder
 Direction and flow control valves.
 Pneumatic pipe and pipe fittings
 Bolts and nuts
 Antirust coat and paint.
Machines and tools used
 Cutting machine
 Hacksaw cutting machine.
 Sensitive drilling machine
 Horizontal milling machine
 Electric arc welding machine
 Table grinder
 Hand grinder
 Surface grinding machine
 Tap and tap holder
4.3.2 DESIGN
Base Frame;
Quantity: 1
Height: 300mm
Length: 900mm
Width: 300mm
Weight: 5kg
Shearing blade;
Quantity: 2
Length: 300mm
Height: 60mm
14
Thickness: 15mm
Blade angle: 15
Weight: 3.5kg
Base Plate;
Quantity: 1
Height: 65mm
Width: 65mm
Thickness: 6mm
Fork end;
Quantity: 1
Length: 75mm
Width: 20mm
Thickness: 5mm
Angle section
Quantity: 1
Height: 45mm
Length: 300mm
Width: 45mm
Thickness: 7mm
Weight: 0.5kg
Connecting link
Quantity: 1
Length: 360mm
Thickness: 5mm
15
Height: 25mm
Weight: 0.3kg
Support links
Quantity: 2
Height: 90mm
Width: 25
Thickness: 5
Blade link
Quantity: 1
Height: 90mm
Width: 20mm
Thickness: 5mm
Welded length: 30mm
Calculation of cutting force on blade.
Let,
A = Area of cross-section of blade which is to be cut by shearing machine
A = (width x thickness)
A = (30 x 0.71) mm2
Let, we have
Pressure P =
By assuming pressure in working cylinder is,
Working Pressure P = 3 bar = 0.3 N/mm2
[ F = 6.39 N ] = Working or cutting force.
16
2) Design of Pneumatic Components:
Clavarino’s equation for closed end cylinder at both ends. For ductile material use to
determine the thickness of cylinder.
Let,
Material of the cylinder is Gray Cast iron.
Sut = Ultimate tensile strength = 200 N/mm2
¥ì = Poisson`s Ratio for the cylinder material = 0.29 (std.)
di = Inner diameter of cylinder = 50mm
Consider,
Double acting cylinder 50 X 50 (Diameter X Stroke)
[ ri =25 mm]
By assuming pressure in working cylinder is, P = 6 bar =0.6 N/mm2
So according to Clavarino’s equation,
For closed end cylinder at both ends to determine the thickness of cylinder
17
Base Frame
Figure 3: base frame layout
18
Shearing blades and link
Figure 4: shearing blades layout
19
4.3.3 General Layout
The following figure shows the general layout for the machine;
Figure 5: general layout of pneumatic machine
Initially the air-compressor is started and allowed the receiver tank air pressure to reach up to 8
bar. The supply air is then passed to the manifold through FRL unit to condition the air and
eligible to industrial use.
From the manifold a separate supply for the machine is taken out and given to ON-OFF switch,
so as to operate the machine at will without interrupting the running of compressor.
Then the pipe carries compressed air first to machine`s Direction Control Valve.
4.4 COST ANALYSIS
Table 2: bill of materials
Sr.
Part name
Material
Quantity
no.
Material
Machining
Total
cost
Cost
cost
A)Base Frame
1]
Main Frame
Mild steel
20 feet
33000
27500
60500
2]
Angle section
Mild steel
1
2750
2750
5500
3]
Cylinder
Base Mild steel
1
1650
1650
3300
plate
20
4]
Support Links
Mild steel
2
1650
1650
3300
acting Plain carbon steel
1
220000
-
220000
control Cast steel
2
46750
-
46750
3m
6600
-
6600
1
38500
-
38750
3
8250
-
8250
B) Pneumatic circuit components
5]
Double
cylinder
6]
Flow
valve
7]
Pipe
PVC
8]
Direction control Alloy steel
valve
9]
Pipe
fitting Cast steel
connections
C) Blades and Accessories
10]
Shearing blades
35CB
2
16500
22000
38500
11]
Blade link
Mild Steel
1
1100
1650
2750
12]
Connecting link
Mild steel
1
1650
1650
3300
13]
Fork end
Mild steel
1
2750
2750
5500
D) OTHERS
14]
Bolts
Alloy steel
11
4400
-
4400
15]
Nuts
Alloy steel
3
550
-
550
16
Antirust Coat
-
100ml
1100
-
1100
17
Paint
-
100ml
2200
-
2200
389400
61600
451000
Grand Total cost (in Uganda shillings)
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CHAPTER FIVE
CONCLUSION AND RECOMMENDATIONS
5.1 CONCLUSION
The range of the cutting thickness can be increased by arranging a high pressure compressor and
installing more hardened blades. This machine is advantageous to small sheet metal cutting
industries as they cannot afford the expensive hydraulic machine.
5.2 RECOMMENDATIONS
The fact that the machine was built, and it brought some improvement in the shearing process,
does not necessarily mean that it will be constantly efficient in all conditions. This is a welldesigned and efficient system, if not well maintained, the efficiency will eventually reduce.
These maintenance services may include: cleaning, lubrication and immediately changing spare
parts which get faults before the rest are also affected or break down.
22
REFERENCES
Books
S.R. Mujumdar, (1993), Pneumatic systems: Principle and Maintenance.
R.K. Jain, (1973), Workshop technology.
S.R. Mujumdar, (1985), Pneumatic System: Principle & Maintenance.
A.S. Aditya Polapragada& K. Sri Varsha, (2012), “Pneumatic Auto Feed Punching, cutting and
Riveting Machine “, International Journal of Engineering Research & Technology (IJERT) Vol.
1
E. Paul. Degarmo, (2003), “Shearing in Metal Cutting”, Pages 518-528, Materials and Processes
in Manufacturing, Eighth edition, Prentice Hall of India Pvt Ltd.
Websites
http://www.google.com/ ,
http://www.engineersedge.com/,
http://www.efunda.com/,
http://www.mechanicalengineeringblog.com/
www.pumpwork.in
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