pedal powered hacksaw machine

Major ProjectON

PNEUMATIC SHEET METAL CUTTING MACHINE

Under the guidance of SUBMITTED BY - Miss. Swati Gangwar Samarjeet yadav (1204240043) Anuj Mishra (1204240008) Ashish Dubey

(1204240012) Rituraj Singh

(1204240042) SonamVerma

(1204240051)Submitted to

Department of Mechanical Engineering Madan Mohan Malaviya University of Technology Gorakhpur, India

1.Introduction

2.Literature Survey

3.Components

3.1 Pneumatic Cylinder

3.2 Sheet Cutter

3.3 Frame Base

3.4 Two way valve

3.5 Hose Connector

3.6 Air Compressor

CONTENTS:

4. Figure5. Working6. Cost Estimation7. Advantages8. Applications

Introduction 1. The objective of the project is to prepare a machine which cuts sheet metal without human efforts but operates pneumatically. Compressed air is used as working media. The compressed air moves the blades of machine to cut the sheet of metal.2. The idea of the project generated due to a manual sheet metal sheering machine in workshop of our college. In that machine sheet metal is placed in between the two sheering blades of machine and the lever is pulled down to move the upper movable blade and cut the work-piece

Literature Survey In shearing operation as the punch descends upon the metal, the pressure exerted by the punch first cause the plastic deformation of the metal. Since the clearance between the punch and the die is very small, the plastic deformation takes place in a localized area and the metal adjacent to the cutting edges of the punch and die edges becomes highly stressed, which causes the fracture to start on both sides of the sheet as the deformation progresses and the sheet is sheared. Like hydraulics, pneumatics is a type of fluid power application where instead of an incompressible liquid,

pneumatics employ gas in their system. Hydraulics present certain advantages over pneumatics, but in a given application, pneumatic powered

equipment is more suitable, particularly in industries where the factory units are plumbed for compressed air.

The air used in pneumatic devices is dried and free from moisture so that it does not create any problem to the internal parts of the system.

Moreover, to avoid corrosive actions, oil or lubricants are added so that friction effects can be reduced. Compressed air is used in most of the machines and in some cases compressed carbon dioxide

COMPONENTS:Various components used in our project are as follows

1. Pneumatic Cylinder2. Sheet Cutter3. Frame4. Two way valve and hose connector5. Compressor

PNEUMATIC CYLINDER Pneumatic cylinder consist piston ,piston rod and

a body or tube. Compressed air enters at one end of the tube

imparting Force on the piston which is then displaced in

order to balance the force exerted on the piston . Cylinders are available in a variety of sizes and

shapes and has varying stroke. A typical cylinder sizes range from a small 2.5

mm air cylinder which might be used for picking up a small transistor or other component.

SHEET CUTTER Sheet cutter are hand-operated shearing tools. They consist of a pair of metal

blades pivoted so that the sharpened edges slide against each other when the handles (bows) opposite to the pivot are closed

High-carbon, high chromium steel is used in production of sheet cutter

FRAME BASE It forms the robust supports to stand the machine vertically. It holds the weight of the vertical post and supports the direction

control valve. It is made of mild steel. It is made of rectangular base with the vertical post and the

horizontal channel.

TWO WAY VALVE A valve is a device that regulates, directs or controls the flow of a fluid (gases,

liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways.

Hose connector Hose connector is a fitting, consisting of a short piece of pipe, usually provided

with a male pipe thread at each end, for connecting two other fittings.

AIR COMPRESSOR An air compressor is a

device that converts power (using an electric motor, diesel or gasoline engine, etc.) into potential energy stored in pressurized air

FIGURE :(FABRICATION OF SHEET METAL CUTTING MACHINE )

Working Initially the air-compressor is started and allowed the receiver tank air pressure to

reach up to 10 bar. The supply air is then passed to the manifold.

At position ‘A’ shows the non-actuated circuit diagram. At this position the piston is steady and locked. All ports are in closed condition.

Position ‘A’

At position ‘B’, the DC valve is at left hand position as shown in figure.

When the piston moves outwards, the force is transmitted through the connecting link and the upper blade moves downwards.

Position ‘B’

Now the DC valve is operated to come at position ‘C’, as shown in figure. The compressed air comes in the rod end of the cylinder and pushes the pistons inwards. The air already present in the cap end side is pushed out of the cylinder.

Position ‘B’

Design Parameters Specifications of the Sheet Metal :

SHEET METAL MATERIAL ALUMINIUM

THICKNESS 0.5 mm

LENGTH OF CUT 25 mm

Max. SHEAR STRENGTH OFALUMINIUM

30 N/mm2

Force Calculation Force required to cut the Sheet = L*t*Tmax

For sheet of 0.5 mm thickness,force required = 25*0.5*30= 375 NThis is the force required to cut the sheet metal, however the initial force required to cut the sheet is more and it is 140-150% than we calculated.Therefore, max force required to cut the sheet = 525 to 562.5 N.Now we have chosen 12 volt DC Air Compressor thatdevelops a pressure of 10.34 bar (150psi).Design of CylinderSince the max force required to cut the sheet = 562.5 NAnd pressure applied by 12 volt compressor =10.34 barTherefore, Force applied by the cylinder,F = (Pi/4)*d2*P

562.5=(Pi/4)*d2*(10.34/10)

d=26.3 mm For safety , we have taken the cylinder of diameter 30 mm.

Cost Estimation:

Pneumatic Cylinder ₹ 2000

Cost28%

Sheet Cutter ₹ 2500 Cost 35%Frame ₹500Cost7%

Two way Valve + Connector

₹1100Cost15%

Compressor ₹ 1000Cost14%

Pneumatic Cylinder ₹ 2000

Sheet Cutter ₹ 2500

Frame ₹500

Two way Valve + Connector ₹1100

Compressor ₹ 1000

ADVANTAGES:

Very CHEAP compared to hydraulic shearing machine. With the help of compressed air, cutting becomes EASY. Fast cutting action is carried out. Cutting without bending is achieved. Good Surface finish High Accuracy

APPLICATIONS:

Sheet metals are used in: Automobile Industry Aircraft Industry Used in laminated sheet cores. Used in transformers and electrical machines.

REFERENCES

• http://www.mechengg.net/2015/03/project-on-pneumatic-sheet-metal.html

• https://www.google.co.jp/imghp?hl=en&tab=wi&ei=cek8VqW8BqKvmAXfvqbQDg&ved=0CBIQqi4oAQ

• https://en.wikipedia.org/wiki/Shearing_(manufacturing)• https://en.wikipedia.org/wiki/Pneumatic_cylinder• http://dir.indiamart.com/search.mp?ss=pneumatic+cylinders• Machine Design by R.S. KHURMI• Design of Machine Elements by V.B. BHANDARI• Theory of Machines by Sadhu Singh

THANK YOU