PNEUMATIC CONTROLLED BAR FEEDING MECHANISM

Submitted in the partial fulfillment of the requirement for the award of

“DIPLOMA IN MECHANICAL ENGINEERING ”

SUBMITTED BY:

1. G.K. MANIGANDAN 4. J. DHANAJEYAN 2. B. KARTHIKEYAN 5. D. DURAIVEL 3. P. BALASUBRAMANI 6. L. PRABHU

Under guidance of

Mr. V.K. RAJENDRAN,M.E.

APRIL 2010.

DEPARTMENT OF MECHANICAL ENGINEERING

A M K TECHNOLOGICAL POLYTECHNIC COLLEGECHEM BARAMBAKKAM, CHENNAI – 602 103

A M K TECHNOLOGICAL POLYTECHNIC COLLEGECHEM BARAMBAKKAM, CHENNAI – 602 103

BONAFIDE CERTIFICATE

This is to certify that this Project work on

“PNEUMATIC CONTROLLED BAR FEEDING MECHANISM”

submitted by …………………… ……………. Reg. No. ……………

in partial fulfillment for the award of

DIPLOMA IN MECHANICAL ENGINEERING

This is the bonafide record of work carried out by him under our supervision

during the year 2012

Submitted for the Viva-voce exam held on ……………..

HEAD OF THE DEPARTMENT PROJECT GUIDE

INTERNAL EXAMINER EXTERNAL EXAMINER

ACKNOWLEDGEMENT

ACKNOWLEDGEMENT

At the outset, we would like to emphasize our sincere thanks to the

Principal Mr. A. VIJAY KISHORE ,MSc., M TECH, MISTE.,

encouragement and valuable advice.

we thank our Esquired Head of Department Mr R. RAJKUMAR,

A.M.I.E, M.E. Phd, for presenting his felicitations on us.

We are grateful on our Entourages Mr. . R RAJKUMAR, A.M.I.E,

M.E,Phd., for guiding in various aspects of the project making it a grand

success.

We also owe our sincere thanks to all staff members of the Mechanical

Engineering Department.

Ultimately, we extend our thanks to all who had rendered their co-

operation for the success of the project.

CONTENTS

TABLE OF CONTENTS

CHAPTER TITLE PAGE NOACKNOWLEDGEMENT

ABSTRACT

LIST OF TABLES

LIST OF FIGURES

NOMENCLATURE

Iiiivviiviiiix

1INTRODUCTION

1.1 OBJECTIVES AND SCOPE

1

2 LITERATURE SURVEY 2

3 BAR REEDING MACHANISM

3.1 BAR FEEDING MECHANISM

3.2 WORKING PRINCIPLE

3.3 CONSTRUCTION

3.3.1. BASE

3.3.2. MOVABLE V – BLOCK

3.3.3. FIXED V – BLOCK

3.3.4. GUIDE ROD

44

44455

4. CYLINDER

4.1 CYLINDER

4.2 TYPES OF CYLINDERS

4.2.1. SINGLE CYLINDER PUMP

4.2.2. DOUBLE CYLINDER PUMP

6666677

4.2.3. TRIPLE CYLINDER PUMP

4.2.4. DUPLEX DOUBLE ACTING PUMP

4.2.5. QUINTUPLEX PUMP

7

CHAPTER TITLE PAGE NO4.3 SINGLE – ACTING CYLINDER

4.4 DOUBLE – ACTING CYLINDER

4.5. SPECIFICATION

5. HAND OPERATING VALVE

5.1 HAND OPERATING VALVE

5.2 TYPES OF HAND OPERATING VALVE

6. POWER HACKSAW MACHINE

6.1. POWER HACKSAW MACHINE

6.1.1. TYPES OF POWER HACKSAW MACHINE

6.1.2. SPECIFICATION OF MACHINE

6.1.3. SPECIFICATION OF MOTOR

7. TEAM SPLIT

8. COST ESTIMATION

9. CONCLUSION

APPENDIX 1 : Base Plate (M.S)

APPENDIX 2: R.H.V- Block (M.S)

APPENDIX 3: Moving V- Block (M.S)

APPENDIX 4 : L.H. V – Block

APPENDIX 5 : Cylinder MTG bracket (M.S. WELD)

APPENDIX 6 : Guide Bush & Guide Rod

APPENDIX 7 : Stopper Screw & Nut

APPENDIX 8 : Stopper Plate

APPENDIX 9 : Isometric view

APPENDIX 10 : Photographic view

REFERENCE

LIST OF TABLES

TABLE LABLE PAGE NO

4.1 Specification of Cylinder

6.1 Machine Specification

6.2 Motor Specification

8.1 Cost Estimation

LIST OF FIGURES

TABLE LABLE PAGE NO

4.1 Single Acting Cylinder

4.2 Double Acting Cylinder

5.1 Hand Operating Valve

6.1 Power Hacksaw Machine

A-1 Base Plate (M.S)

A-2 R.H.V. Block (M.S)

A-3 Moving V- Block (M.S)

A-4 L.H.V – Block (M.S)

A-5 Cylinder MTG bracket (MS WELD)

A-6 Guide Bush & Guide Rod

A-7 Stopper Screw & Nut

A-8 Stopper Plate

A-9 Isometric View

A-10 Photographic View

NOMENCLATURE

NOTATIONS UNITS DESCRIPTION

D mm Diameter of the Cylinder

A M2 Cross sectional area of the Cylinder

R mm Radius of crank

N rpm Speed of Crank

L mm Length of Stroke

Hs mm Height of centre of the cylinder above the

liquid surface, m

Hd mm Height of which the liquid is raised above

the centre of the cylinder m

V m3 Volume of liquid sucked during suction

stroke

P kw Power required to drive the pump

CHAPTER – 1

INTRODUCTION

1.1 OBJECTIVE AND SCOPE :

The automatic bar feeding mechanism in the hacksaw machine. The bar is

feed on the machine. When the machine is switched – ON. A bar is

automatically feed in the machine in ensure uniform length. When a number of

pieces of same length are to be cut in this machine. The power operated

hacksaws use on electric motor precutting metals by providing reciprocating

motion to the through on eccentric. For this mechanical construction. We

purchased components and after suitable modification and machining some

parts. We have assembled them in addition to this we have provided some

additional features in our machine as part of our project work. They are as

follows a coolant pump coupled with main shaft which automatically supplies

coolant whenever the machine is switched on a bar stops attachment to ensure

uniformity in length when a number of pieces of same length are to be cut.

CHAPTER 2

LITERATURE SURVEY

Literature survey is the documentation of a comprehensive review of the

published and unpublished work from secondary sources data in the areas of

specific interest to the researcher.

The Library is a rich storage base for secondary data and researchers used

to spend several weeks and sometimes months going through books, journals,

newspapers, magazines, conference proceedings, doctoral dissertations,

master’s these, government publications and financial reports to find

information on their research topic.

With computerized database now readily available and accessible the

literature search is much speedier and easier and can be done without entering

the Portals of a library building.

The researcher could start the literature survey even as the information

from the unstructured and structured interviews is being gathered.

Reviewing the literature on the topic area at this time helps the researcher

to focus further interviews more meaningfully on certain aspects found to be

important is the published studies even if these had not surfaced during the

earlier questioning.

So the literature survey is important for gathering the secondary data for

the research which might be proved very helpful in the research.

The literature survey can be conducted for several reasons. The literature

review can be in any area of the business.

The purpose of the literature survey is to identify information relevant to

freshwater and pollutant discharges from the Rio Grande and Arroya Colorado

and the potential and known impacts of these discharges within the project area,

identify those areas where there is an absence or paucity of data, and make

recommendations for future studies and planning efforts.

CHAPTER – 3

BAR FEEDING MECHANISM

3.1. BAR FEEDING MECHANISM

Material feed and placement mechanisms for a steel cutting machine

result in a power saving and accurate clamping device. A work piece is moved

into cutting position and clamped in place by the feed mechanism. After being

cut by the cutting machine, the cut piece is slowly laid down by the placement

mechanism. Not only can noise and vibration be eliminated, but also the safety

of workers is improved, and machine life is extended.

3.2. WORKING PRINCIPLE

When the hand operated lever is moved into forward position, then

clamping cylinder 1 and 2 was released the clamping position and meanwhile

feeding cylinder was moved backward. The lever moved into backward position

then clamping cylinder hold the rod and after few second later feeding cylinder

moves toward the forward. By using the stopper screw, we can adjust the length

of the rod. So we can cut the rod by using power hacksaw machine.

3.3 CONSTRUCTION

We are detail discuss about the construction of bar feeding

mechanism as given below.

3.3.1. BASE

It is made up of mild steel. It is used to fix all other components.

3.3.2. MOVEABLE V - BLOCK

After release the clamping cylinder 1 &2, then feeding cylinder moves

the backward position along with them movable V- block . It is made up of mild

steel.

3.3.3. FIXED V- BLOCK

There are two fixed V- Block in bar feeder. One is fixed on left

side and another one is on right side. Both the block support the work piece. It is

made up of mild steel.

3.3.4. GUIDE ROD :

It is used to guide the movable V-Block. It is made up of mild steel

with good surface finishing.

CHAPTER – 4

INTRODUCTION TO PNEUMATIC SYSTEM

INTRODUCTION TO PNEUMATICS

In engineering field may Machines make use of a fluid or compressed air to

develop a force to move or hold an object

A system which is operated by compressed air is known as Pneumatic

System. It is most widely used the work Piece turning drilling sawing etc.

By the use of Pneumatic System the risk of explosion on fire with compressed

air is minimum high working speed and simple in construction.

PNEUMATIC COMPONENTS

In engineering field, many machines make use of fluid for developing a

force to move or hold an object. A number of fluid can be used in devices

and system. Two commonly used fluids are oil and compressed air. A

system which is operated by compressed air. A system which is operated by

compressed air is know as pneumatic system.

AIR COMPRESSOR

Compressor is a device which gets air fro the atmosphere and compresses

it for increasing the pressure of air. Thus the compressed air. Thus the

compressed air used for many application.

The compression process requires work in put. Hence a compressor is

driven by a prime mover. Generally an electric motor is used as prime

mover. The compressed air from compressor is stored in vessel called

reservoir. Fro reservoir it be conveyed to the desired place through pipe

lines.

2. FLTER

In pneumatic system, an air filter is used to remove all foreign matter. An

air filter dry clean air to flow without resistance various materials are used for

the filter element. The air may be passed thorugh a piece metal, a pours stone

felt resin impregnated paper. In some filters centrifugal action or cyclone action

is used to remove foreign matters.

3. PRESSURE REGULATOR

Constant pressure level is required for the trouble free operation of a

pneumatic control., A pressure regulator is fitted downstream of the

compressed air filter. It provides a constant set pressure at the outlet of the

outlet of the regulator. The pressure regulator is also called as pressure

reducing valve or pressure regulating valve.

4. LUBRICATOR

The purpose of an air lubricator is to provide the pneumatic components

with sufficient lubricant. These lubricants must reduce the wear of the moving

parts reduce frictional forces and protect the equipment from corrosion.

Care should be taken to ensure that sufficient lubrication is provided. But

excessive lubrication should be avoided.

.

5. FLR Package (or) FRL Package

The air service unit is a combination of following units.

1. Compressed air filter

2. Compressed air regulator

3. Compressed air lubricator

Air Filter, regulator and lubricator are connected together with close

nipples as one package. This unit is know as FLR (Filter, regulator, lubricator.)

6. PRESSURE CONTROL VALVE :

Each hydraulic system is used to operate in a certain pressure range.

Higher pressure causes damage of components. To avoid this pressure control

valves are fitted in the circuits.

7. Direction control valve :

Directional control valves are used to control the direction of flow. The

design principle is a major factor with regard to service life actuating force

switching times etc.

8. Piston and Cylinder

single acting pneumatic cylinder;

PNEUMATIC CITCUIT SYMBOL FOR SINGLE ACTING PNEUMATIC CYLINDER;

Pneumatic cylinders (sometimes known as air cylinders) are mechanical devices

which produce force, often in combination with movement, and are powered by

compressed gas (typically air).

To perform their function, pneumatic cylinders impart a force by converting the

potential energy of compressed gas into kinetic energy. This is achieved by the

compressed gas being able to expand, without external energy input, which itself

occurs due to the pressure gradient established by the compressed gas being at a

greater pressure than the atmospheric pressure. This air expansion forces a piston to

move in the desired direction. The piston is a disc or cylinder, and the piston rod

transfers the force it develops to the object to be moved.

When selecting a pneumatic cylinder, you must pay attention to:

how far the piston extends when activated, known as "stroke"

surface area of the piston face, known as "bore size"

action type

pressure rating, such as "50 PSI"

type of connection to each port, such as "1/4" NPT"

must be rated for compressed air use

mounting method

Types

Although pneumatic cylinders will vary in appearance, size and function, they

generally fall into one of the specific categories shown below. However there

are also numerous other types of pneumatic cylinder available, many of which

are designed to fulfill specific and specialised functions.

Single acting cylinders

Single acting cylinders (SAC) use the pressure imparted by compressed air to

create a driving force in one direction (usually out), and a spring to return to the

"home" position

Double acting cylinders

Double Acting Cylinders (DAC) use the force of air to move in both extend and

retract strokes. They have two ports to allow air in, one for outstroke and one for

instroke.

Other types

Although SACs and DACs are the most common types of pneumatic cylinder,

the following types are not particularly rare:

Rotary air cylinders: actuators that use air to impart a rotary motion

Rodless air cylinders: These have no piston rod. They are actuators that

use a mechanical or magnetic coupling to impart force, typically to a

table or other body that moves along the length of the cylinder body, but

does not extend beyond it.

Sizes

Air cylinders are available in a variety of sizes and can typically range from a

small 2.5 mm air cylinder, which might be used for picking up a small transistor

or other electronic component, to 400 mm diameter air cylinders which would

impart enough force to lift a car. Some pneumatic cylinders reach 1000 mm in

diameter, and are used in place of hydraulic cylinders for special circumstances

where leaking hydraulic oil could impose an extreme hazard.

Pressure, radius, area and force relationships

Although the diameter of the piston and the force exerted by a cylinder are

related, they are not directly proportional to one another. Additionally, the typical

mathematical relationship between the two assumes that the air supply does not

become saturated. Due to the effective cross sectional area reduced by the area of

the piston rod, the instroke force is less than the outstroke force when both are

powered pneumatically and by same supply of compressed gas.

The relationship, between force on outstroke, pressure and radius, is as follows:

This is derived from the relationship, between force, pressure and effective

cross-sectional area, which is:

F = p A\,

With the same symbolic notation of variables as above, but also A represents the

effective cross sectional area.

On instroke, the same relationship between force exerted, pressure and effective

cross sectional area applies as discussed above for outstroke. However, since

the cross sectional area is less than the piston area the relationship between

force, pressure and radius is different. The calculation isn't more complicated

though, since the effective cross sectional area is merely that of the piston less

that of the piston rod.

For instroke, therefore, the relationship between force exerted, pressure, radius

of the piston, and radius of the piston rod, is as follows:

Where:

F represents the force exerted

r1 represents the radius of the piston

r2 represents the radius of the piston rod

π is pi, approximately equal to 3.14159.

VALVE CONNECTORS;

POLYURETHANE TUBE ; shortly say PUN tube;

Manual operations involving heavy lifting. Pushing or pulling motions

can be firing for the operations and can induce a monotony which results in

lowered production. Cylinders have been designed to carry out these

movements with a pre – determined force and stroke and can be fitted to

synchronize with operation cycles of many machines it is worth wile to

examine the existing plan and methods of movement and to consider the

numberous mechanical applications which the range of pneumatic cylinders

make possible. Quality is to keynote of air cylinder. Engineer them into you

production setup to get the last ounce of power, speed and efficiency to save

time, space and money.

Piston is cylinder part which moves in a cylinder have corresponding hole

on it. To make the strokes effective there is no gap between them or with a very

tiny gap, part of the micron. The cylinder and its piston have a glazing surface

where there is a contact between them for easy motion of piston and avoiding

wear and tear of both. The outer side of the cylinder have mountings consists

of plate and studs attached with it. But the of these mountings, the cylinder and

piston assembly can fitted on any place of the piston have threads on it for

fastening theother parts (or) accessories according the operating performed and

the application required. We can fit holding devices, Clamping materials or

other metal cutting and forming ports with which can be movable with the

piston.

Pneumatics are used practically in every industry for a wide variety of

manufacturing process, pneumatics equipments are used for multiple reasons.

The best reason is that it is air powered ordinary air turns out to be very

excellent as a fluid power components.

Solenoid Valve :

In order to automate the air flow in our system we have to provide an

electrically controlled valves. Electrical devices can provide more effective

control, less expensive interlocks having many additional safety features and

simplified automatic sequencing when a machine must operate in a hazardous

area, remote actuation is a desirable. The operator can provide satisfactory

control though electrical devices from a remote point with in a safe area, uding

a semi automatic system and these electrical flow control devices are also in use

in full automation by providing proper action signals.

Push and pull actuation can be priced b solenoids. These movements are

used to open and close the pop pet type valves. These actuations are done

according to the signals given to the solenoid coil when the decided by the

program. The outlet of solenoiud coil when the decided by the program,. The

outlet of solenoid valve is connected to a spray gun, which is going to spray the

paint.

SOLENOID OPERATED VALVES:

Solenoid valves are electromechanical devices like relays and contractors.

A solenoid valve is used to obtain mechanical movement in machinery by

utilizing fluid or air pressure. The fluid or air pressure is applied to the cylinder

piston through a valve operated by a cylindrical electrical coil. The electrical

coil along with its frame and plunger is known as the solenoid and the assembly

of solenoid and mechanical valve is known as solenoid valve. The solenoid

valve is thus another important electromechanical device used in control of

machines. Solenoid valves are of two types,

1. Single solenoid spring return operating valve,(5/2)

2. Double solenoid operating valve.

In fig 1 is shown a single solenoid spring return valve in its de-energized

condition. The symbol for the solenoid and the return are also shown. The

solenoid valve is shown connected to the cylinder to help readers understand

the solenoid valve action. In the de energized condition, the plunger and the

valve spool position as shown in figure 1.

In this position of spool, port P is connected to port A and port B is connected to

tank or exhaust (i.e. atmosphere) if air is used. Spring pressure (S) keeps the

spool in this condition as long as the coil is de energized. Fluid pressure from

port P through port A is applied to the left side of the cylinder piston. Thus the

cylinder piston moves in the right direction. Now

5/2 WAY VALVE

when the solenoid coil is energized, plunger is attracted and it pushes the spool

against spring pressure.

The new position of plunger and spool are shown in fig 2.

In this position of spool, port A gets connected to tank and port P gets

connected to port B. Thus pressure is applied to the cylinder piston from right

and moves the piston rod to the left. At the same time fluid in the other side is

drained out to the tank. When the solenoid coil is again de energized, the spring

(S) will move the spool to its original position as shown in figure 1. Thus,

normally when the solenoid coil is de energized the piston rod remains

extended.

PNEUMATIC CIRCUIT DIAGRAM

PNEUMATICFITTING

PNEUMATIC FITTINGS:

There are no nuts to tighten the tube to the fittings as in the conventional

type of metallic fittings. The tube is connected to the fitting by a simple push

ensuring leak proof connection and can be released by pressing the cap and does

not require any special tooling like spanner to connect (or) disconnect the tube

from the fitting.

SPECIFICATION OF THE FITTING:

Body Material - Plastic

Collect/Thread Nipple - Brass

Seal - Nitrate Rubber

Fluid Used - Air

Max. Operating Pressure - 7 Bar

Tolerance on OD of the tubes - 1 mm

Min. Wall thickness of tubes - 1 mm.

FLEXIBLE HOSES:

The Pneumatic hoses, which is used when pneumatic components such as

actuators are subjected to movement. Hose is fabricated in layer of

Elastomer or synthetic rubber, which permits operation at high pressure. The

standard outside diameter of tubing is 1/16 inch. If the hose is subjected to

rubbing, it should be encased in a protective sleeve.

ADVANTAGES AND LIMITATIONS

ADVANTAGES:

The Pneumatic arm is more efficient in the technical field

Quick response is achieved

Simple in constructions

Easy to maintain and repair

Cost of the unit is less when compared to other robotics

No fire hazard problem due to over loading

Comparatively the operation cost is less

The operation of arm is faster because the media to operate is air

Continuous operation is possible without stopping.

LIMITATIONS:

High torque cannot be obtained.

Load Carrying capacity of this unit is not very high (3 – 5 kg/s)

Silencer may be used, to reduce the noise of compressed air

APPLICATION

1) DISCHARGE OF WORKPIECE:

The arm fed has wide application in low cost automation. It can be used

in automated assembly lines to pick-up the finished product from workstation

and place them in the bins. It can also be used to pick-up the raw material and

place them on the conveyor belts and vice versa.

2) JOB CLAMPING:

This unit can also be used in clamping operations in certain areas of mass

productions where clamping and unclamping have to be done at high speeds.

The application of this unit is limited to operations, which involves moderate

clamping forces.

3) TRANSFER OF JOBS BETWEEN WORK STATIONS:

The gripping method used in a low cost automation to move the work

piece from one workstation to another. The combination of an angular rotary

motion is the principle behind this method. The gripper holds the work rigidly.

The to and fro motion is achieved by means of the actuating cylinder.

4) TOOL CHANGING APPLICATION:

When the pneumatic arms are made smaller in size they can be used in

automatic tool changer in CNC turning and drilling machines, by attaching

suitable tool holding device to the rotary cylinder.

CHAPTER – 5

ELECTRICAL CIRCUIT DETAILS

CIRCUIT DETAILS

1. Micro controller system

2. Interface Circuit for Solenoid valves

3. Power supply (230V A.C. to 24vdc V and 5V DC)

4. Key Board Circuit

MICRO CONTROLLER SYSTEM:

This system monitors the engine condition by using PIC 16F870 (28 pin

IC Package) micro controller. The pin details of micro controller are shown in

figure.

The circuit diagram for this micro controller board is shown below,

in no 2&5.The pin no 1 is RESET switch..The INPUTS are connected to

port B .The OUTPUTS are connected to PORT C.6 MHZ crystal is

connected to pin no 9,10.

Keypad interface;

Here seven soft microswitches are soldered in the main board and their

connections are shown below.

POWER SUPPLY 5V DC AND 24V DC;

A 12 –0 -12v step down transformer is used to stepdown 230V AC to

24V AC .This 24V AC supply is converted to 12V DC using four rectifier

diodes. The voltage from the rectifier section is regulated to 12V DC using 7812

IC . From 12V DC the 7805 IC is used for regulating 5V DC for the power

supply of microcontroller.

the power supply circuit is shown in fig.

INTRODUCTION:

All the electronic components starting from diode to Intel IC’s only work

with a DC supply ranging from +5V to +12V. We are utilizing for the same, the

cheapest and commonly available energy source of 230V-50Hz and stepping

down, rectifying, filtering and regulating the voltage.

STEP DOWN TRANSFORMER:

When AC is applied to the primary winding of the power transformer, it

can either be stepped down or stepped up depending on the value of DC needed.

In our circuit the transformer of 230V/15-0-15V is used to perform the step

down operation where a 230V AC appears as 15V AC across the secondary

winding. Apart from stepping down voltages, it gives isolation between the

power source and power supply circuitries.

RECTIFIER UNIT:

In the power supply unit, rectification is normally achieved using a solid

state diode. Diode has the property that will let the electron flow easily in one

direction at proper biasing condition. As AC is applied to the diode, electrons

only flow when the anode and cathode is negative. Reversing the polarity of

voltage will not permit electron flow. A commonly used circuit for supplying

large amounts of DCpower is the bridge rectifier. A bridge rectifier of four

diodes (4 x IN4007) are used to achieve full wave rectification. Two diodes

will conduct during the negative cycle and the other two will conduct during the

positive half cycle, and only one diode conducts. At the same time one of the

other two diodes conducts for the negative voltage that is applied from the

bottom winding due to the forward bias for that diode. In this circuit due to

positive half cycle D1 & D2 will conduct to give 0.8V pulsating DC. The DC

output has a ripple frequency of 100Hz. Since each alteration produces a

resulting output pulse, frequency = 2 x 50 Hz. The output obtained is not a pure

DC and therefore filtration has to be done.

The DC voltage appearing across the output terminals of the bridge

rectifier will be somewhat less than 90% of the applied rms value. Normally

one alteration of the input voltage will reverse the polarities. Opposite ends of

the transformer will therefore always be 180 degree out of phase with each

other. For a positive cycle, two diodes are connected to the positive voltage at

the top winding.

FILTERING CIRCUIT:

Filter circuits which is usually capacitor acting as a surge arrester always

follow the rectifier unit. This capacitor is also called as a decoupling capacitor

or a bypassing capacitor, is used not only to ‘short’ the ripple with frequency of

120Hz to ground but also to leave the frequency of the DC to appear at the

output. A load resistor R1 is connected so that a reference to the ground is

maintained. C1, R1 is for bypassing ripples. C2, R2 is used as a low pass filter,

i.e. it passes only low frequency signals and bypasses high frequency signals.

The load resistor should be 1% to 2.5% of the load.

1000f/25V : for the reduction of ripples from the pulsating

10f/25V : for maintaining the stability of the voltage at the load side.

0.1f : for bypassing the high frequency disturbances

BLOCK DIAGRAM FOR POWER SUPPLY

STEP DOWN BRIDGE POSITIVETRANSFORMER RECTIFIER CHARGE

CAPACITOR

5V 12V REGULATOR REGULATOR

MOTHER DISPLAY

BOARD BOARD RELAY

VOLTAGE REGULATOR:

The voltage regulators play an important role in any power supply unit.

The primary purpose of a regulator is to aid the rectifier and filter circuit in

providing a constant DC voltage to the device. Power supplies without

regulators have an inherent problem of changing DC voltage values due to

variations in the load or due to fluctuations in the AC linear voltage. With a

regulator connected to the DC output, the voltage can be maintained within a

close tolerant region of the desired output. IC7812 and 7912 is used in this

project for providing +12V and 12V DC supply.

5 TO 24 V DC DRIVE CARD

Here we have to drive the 24V DC load. The 5V signal from the PIC

16F870 micro-controller is fed into the input of interface circuit. SL100

transistor is used here for high speed switching purpose and IRF 540N

MOSFET is connected to the motor to handle the larger current drawn by the

valves.

CHAPTER – 6

POWER HACKSAW MACHINE

CHAPTER – 6

POWER HACKSAW MACHINE

6.1 POWER HACKSAW MACHINE :

Power hacksaws are used to cut large sizes (sections) of metals

such as steel. Cutting diameters of more than 10/15mm is very hard work with a

normal hand held hacksaw. Therefore power hacksaws have been developed to

carry out the difficult and time consuming work.

The heavy ‘arm’ moves backwards and forwards, cutting on the forward

stroke.

The metal to be cut is held in a machine vice which is an integral part of

the base. Turning the handle tightens or loosens the vice. The vice is very

powerful and locks the metal in position.

When cutting is taking place, the metal and especially the blade heats up

quickly. Coolant should be fed onto the blade, cooling it down and lubricating it

as it cuts through the metal.

Without the use of coolant the blade will over heat and break /snap. This

can be dangerous as the blade can break with powerful force, shattering.

When the metal is placed and fixed in the vice, the blade is lowered onto

its top surface. The diagram below shows the ‘arm’ being lowered with the

‘adjusting’ handle’.

Blades of power hacksaws are graded according to the material they are

made from and the number of teeth per inch. Top quality blades are

manufactured from High Speed Steel. Although there are cheaper alternatives

such as carbon steel blades.

In general the number of teeth per inch (TPI) range from 14 to 24 the

more teeth per inch – the smoother the cut.

Every power hacksaw should have a foot switch / emergency switch. This

allows the operator to turn the machine off quickly by using his/her foot to step

on the switch. The foot switch is normally positioned at the front or side of the

machine.

Power hacksaws have electric motors that power the blade through a

pulley system. Some have ratchet systems. The pulley system showed below

shows how rotary power is transferred from the motor and changed to

reciprocating motion allow the blade to cut through the material.

Most power hacksaws have two pulley wheels. If the belt is placed on the

smaller pulley wheel the speed of cut will be fast. Changing the belt so that it

runs round the larger pulley wheel will reduce the speed.

6.1.1. TYPES OF POWER HACKSAW MACHINE

Hydraulic type

Pneumatic type

Hydro Pneumatic type

6.1.2. SPECIFICATION OF MACHINE

Speed of the motor 1400 rpm

Stroke length 110 – 185mm

Speed of crank 105 rpm

Max – height of job that could be

machined.

4 inches.

Table 6.1. Machine Specification

6.1.3. SPECIFICATION OF MOTOR

Phase 3 Phase

Voltage 1095 volt

Speed 1400 rpm

Power 0.75 watts

Rating Constant

Frequency 50 Hz

Horse power 1 HP

Current 415 Amps

Table 6.2. Motor Specification

CHAPTER 7

TEAM SPLIT

CHAPTER 7

TEAM SPLIT

We decided to split our work to join two members for our work. We split

our work as follows,

M. VINOD KUMAR

&

M. SHANMUGAM

G..B. SURESH

&

G. DAVID RAJA

R. SUNDAR

R. SELVARAJ

CHAPTER – 8

COST ESTIMATION

CHAPTER – 8

COST ESTIMATION

S.NO PARTICULARS NO.OFF AMOUNT

1. BASE PLATE 1 550

2. R.H.V. BLOCK 1 500

3. MOVING V BLOCK 1 450

4. L.H.V. BLOCK 1 500

5. MTG. CYLINDER BRACKET 2 700

6. GUIDE ROD 2 500

7. GUIDE BUSH 2 400

8. STOPPER SCREW 1 100

9. NUT 8 50

10. STOPPER SCREW 1 50

11. V- CLAMP 2 150

12. PNEUMATIC CYLINDER 3 2000

13. HAND OPERATING VALVE 1 500

14. SCREW 8 100

15. 1/8TH HAND OPERATING CONNECTOR 5 250

16. 1/4TH HAND OPERATING CONNECTOR 6 250

17. T-CONNECTOR 2 50

18. PIPE (P6) 4M 1 50

19. ALUMINIUM ROD 1 150

TABLE 8.1 COST ESTIMATION

TOTAL COST OF THIS PROJECT : RS. 6000/-

CHAPTER 9

CONCLUSION

CHAPTER 9

CONCLUSION

The machine was erected in the fitting shop it is a pneumatically operated

machine. It can be adjusted for required cutting length of bar automatically by using

power hacksaw machine.

The machine is very much useful for cutting work pieces for actively classes in

fitting shop and near by welding shop.

REFERENCE

REFERENCE

Bansal, R.K., “Fluid Mechanics and Hydraulics Machines” (5th edition), Laxmi

publications (P) ltd, New Delhi, 1995.

Ramamirtham,S., “Fluid Mechanics and Hydraulics and Fluid Machines”,

Dhanpat Rai and Sons, Delhi, 1998.

P.C. Sharma, “A Text Book of Production Engineering”, S. Chand and Co.ltd,

IV edition, 1993.

Hajra Choudry, “Elements of work shop Technology – Vol. II” Media

Promoters. 2002.

Majundar s.r., “Pneumatic systems – Principles and Maintenance”, tata

McGraw hill, 1995.