Project Review (1)

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AUTOMATIC PUNCHING MACHINE USING PNEUMATIC SYSTEMTEAM MEMBERS: R.GAUTTHAM(711112114009) A.S.KARTHI(711112114016) T.LOGESHWARAN(711112114022) M.MAYILSAMY(711112114302) FACULTY GUIDANCE Mr. T.GANDHIRAM B.E. ABSTRACTThe proposed work describes the design and fabrication of prototype of automatic punching machine controlled by relays and sensors. Punching or pressing process is the one of most important and necessary processing step in manufacturing industries. By automating this process one can have a greater control over the process. Solenoid valves are used for control the system. This system can replace the existing manual model. It is possible to achieve good results in the form of reduced manufacturing lead time, reduced cost and increase safety of the worker.

PROBLEM IDENTIFICATIONPLC system is interfaced with the conventional punching process for achieving the automation.By using such kind of PLC for achieving automation will increase the capital investments of every manufacturing sectors. In addition, mechanical and electrical installation cost will also be included. If the machinery cost is high, obviously it will influence the total production cost. Thus resulting in the increase of final products retail price. In manual or conventional methods of pressing the disadvantages are: * Higher material handling time * Manufacturing lead time * Angular misalignment of the sheet * Reduced safety for the worker INTRODUCTION Sheet metal has replaced many cast , forged and machined products.Punching or pressing is the initial and main operation in the process sequence.Automation is defined as Technology concerned with application of mechanical, electrical, computer based system to operate and control system.It may reduce manufacturing lead time, increase productivity and to improve worker safety. It has easier implementation of mass production as well as greater control on technical parameters . PNEUMATIC CYLINDERS Double acting cylinders(DAC) use the force of air to move in both extend and retract strokes. Force of the compressed air make the cylinder to extent and retract. ADVANTAGES: Force builds up in both directions of movement. Constant force(dependent on stroke). Strokes of several meters are possible.

SENSORSA sensor is a device which receives and respond to a signal.It plays a major role in automation sector.

Main criteria to use sensors are cost reduction , rationalization automation , flexibility and environmental protection.The sensors used in this project is INDUCTIVE PROXIMITY SENSORS -DC TYPE. RELAYSA relay is an electromechanical device that is actuated by an electrical current.It has wide variety of applications throughout industry and automation systems.It is used because of their simplicity , long life , high reliability.

Circuit DiagramRelay

SWITCH MODE POWER SUPPLYSwitch Mode Power Supply(SMPS) transfer electric power from a source (AC mains) to the load by converting the characteristics of current and voltage. SMPS uses a switching a regulator to convert electric power efficiently. SMPS always provide a well regulated power to the load irrespective of the input variation. SMPS regulates the output power by varying the on to off time using minimum voltage so that efficiency is very high compared to the linear power supply.

5/2 SOLENOID VALVE A valve is a device that regulates the flow of fluid (gases, liquids, fluidized solids or slurries) by opening and closing or partially obstructing passage ways. A 5/2 way directional valve from the name itself has 5 ports equally spaced and 2 flow positions. The compressed air flows the passage it makes the retract or extend a double acting cylinder.

Circuit DiagramSolenoid ValveMODELLING

ELECTRO PNEUMATIC CIRCUIT DIAGRAM

DIAGRAM EXPLANATIONA0, A1 - Sensor for loading purposeB0, B1 - Sensor for punching purposeC0,C1 - Sensor for unloading purposeS1, S2, S3- 5/2 Spring actuated solenoid valve RL1 to RL6- RelayCylinder A - Loading PurposeCylinder B- Punching PurposeCylinder C - Unloading purpose

COMPONENTS USED Pneumatic Cylinders5/2 spring actuated solenoid valveCompressorFilter, Reservoir, Lubricator(FRL) Unit Relay Switch Mode Power Supply(SMPS)

WORKING METHODLOGYWhen the switch S1 is pressed, the air supply will flow to all valves of the system.The sensor A1 is actuated, then the cylinder A is fully extended and work piece is placed manually infornt of cylinder A and the cylinder rod clamp the work piece.The sensor senses the work piece position and it actuates the sensor B1.The sensor B1 is actuated, then the cylinder B is fully extended and punching operation performed on the work piece.The punching operation can carried out at a given pressure from the compressor unit.Continued.,Before that , the air from the compressor is filtered by using Filter, Reservoir, Lubricator(FRL) unit.The sensor B0 is actuated, then the cylinder B is fully retracted and back to original position.The sensor A0 is actuated, then the cylinder B is fully retracted and unclamped the work piece. The sensor C0 is actuated, then the cylinder C is fully extended and move the punched work piece. And hence the cycle repeats.

PROCESS FLOWCHARTstartCylinder A extendCylinder B extendCylinder B retractCylinder A retractCylinder C extendCylinder C retractstopCALCULATION GIVENCylinder A rod diameter = 12mmCylinder B rod diameter= 12mmCylinder C rod diameter = 10mmCompressor pressure = 5 Bar

FORMULAE Force = Pressure Area

Area = where, Pressure in N/m Force in N Area in mm2

FORCE CALCULATION Cylinder A = Pressure Area =5105 F = 44.41N

Cylinder B =Pressure Area =5105 F= 44.41N

Cylinder C = Pressure Area =5105 F= 39.26 N

COST ESTIMATIONS.NONAME OF THE MATERIALQUANTITYPRICE in (Rs.)1.Pneumatic cylinder345002.5/2 Spring actuated solenoid valve315003.Inductive proximity sensor612004.12V/2A switch mode power supply15505.12V Relay101506.Multi colour wire41607.Fasteners201008.Cardboard -2009.Steel tube-400Total cost8760/-ADVANTAGESLess environmental pollutionLess Noise processSimple constructionHigher work efficiencyEasy maintenanceLight weightFaster production High safety for workers

CONCLUSIONIn this project, a working model of punching machine using pneumatic system is discussed.

By using sensors, a good control over the system can be achieved , manufacturing time is reduced by developing a automatic feeding mechanism.

The workers safety can be increased by reducing the human participation in the process.REFERENCE 1.International journal of Advanced Mechanical Engineering ISSN 2250-3234 Volume4, Number 5(2014), pp.509-517 Research India Publications http://www.ripublication.com 2. Applied Hydraulics and Pneumatics, Pearson Publication.