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BY

G.SHARATH CHANDR (097Y1A0315)SRIKAR SOOGOOR (097Y1A0344)

VINEETH POSHALA (097Y1A0325)

P.JITHENDER (097Y1A0337)

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INTRODUCTION Bharat Heavy Electricals Limited is the largest engineering

and manufacturing enterprise in India in the energyrelated / infrastructure sector today and ranks among the

top twelve manufacturers of power equipment in the world.

Today BHEL has 14 Manufacturing Divisions, 4 PowerSector regional Centers, 8 Service Centers 18 regional

offices and large number of Project Sites spread all overIndia and abroad enables the Company to promptly serveits customers and provide them with suitable products ,systems and services efficiently and at competitive prices.

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Manufacturing Process The benefits of civilization which we enjoy today are

essentially due to the improved quality of productsavailable to us The improvement in the quality of the goods

can be achieved with proper design that takes intoconsideration the functional requirement as well as itsmanufacturing aspects. This would ensure a better productbeing made available at an economical cost.

Manufacturing involves turning raw material to finishedproducts to be used for various purposes. In the present agethere have been increasing demands on the productperformance by way of desirable exotic properties

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Manufacturing Processes are classified into four categorie:-

Casting Processes : Ex: Sand casting, die casting, centrifugal casting,precision investment casting etc

Forming Processes : Ex: Rolling, press forging, wire drawing, sheetmetal operations etc

Fabrication Processes : It is a secondarymanufacturing process. Ex:Electric arc welding, gas welding, soldering, brazing etc

Material removal processes: It is also the secondarymanufacturingprocess. It is the expensive process. This process delivers gooddimensional accuracy and surface finish. Ex : Turning, milling, drilling,grinding etc

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Material removing process likemilling,turning,grinding,drilling etc are carried on cncmachines

cnc machines are preffered for accurate job work withaccurate dimensions

Material is removed faster when compared with other

machines Material removal rate is more when compared with

other machines

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DEVELOPMENT OF MACHINE TOOLS

GENERAL PURPOSE MACHINES (GPM)(CONVENTIONAL MACHINES)

SPECIAL PURPOSE MACHINES (SPM)(AUTOMATICS)

NUMERICAL CONTROL MACHINES

COMPUTER NUMERICAL CNTROLMACHINES

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Comparison of GPM / SPM / CNC :-

GPM - Completely manual SPM - Built in automatic cycles / For mass

production / Changes are difficult

CNC - Highly flexible / Suitable for batch

production / Job production as Per production

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COMPUTER NUMERICAL CONTROL OF

MACHINE TOOLS

By controlling the relative movements between the tooland the work piece geometrical shapes are machined.Control of these relative movements through coded letters

numbers is known as Numerical Control of machinetools.

In conventional machine operator directly controlling themachine functions. Where as in NC machine a separatemedia which is in between machine and operator is

controlling the machine functions. These NC machines donot have any memory of their own and hence capable ofonly executing a simple block of information fed to it at atime.

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BASIC COMPONENTS OF NC

Program ofinstructions

MCU Machine tool

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Program of instructions: The program instructions is the detailed step by step of

directions which tell the machine tool, what to do.

Machine control unit: This consists of the electronics and hardware that read and

interpret the program and convert it into mechanicalactions of the machine tool.

Machine tool: It is the part of the NC system which performs the useful

work.

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OPERATING PRINCIPLE :

Conventional machine tool NCmachine tool

Operators brain = NC controller

Hands = DC servo drives

Eyes = Feed back system

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Special purpose machine tools :

Because of the CNC technology new types of machines are beingmade like machining centers which are predominantly made forprismatic components. Turning centers are being made formachining components which have more of turning operationsbut also having operations which call for milling, drilling and

tapping. These machines are also called CNC lathes with driventools or live tools. These machines have turret which hasindependent drive, programmable through CNC system andsome of the tool positions can have tools which will rotate. Usingthese machines, the operations like slotting, key way milling,

drilling and tapping can be completed after completing theturning operations. Similarly, the machining centers areequipped with CNC controlled facing and turning attachmentsto complete the turning operations in the prismatic components.

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Adaptive controls For machining operations, the term adaptive control denotes a control

system that measures certain output process variables and uses them tocontrol the process. Some of the process variables that have been usedin adoptive control are spindle deflection, torque, cutting temperature,

Vibration, amplitude and horse power. The motivation for developingan adaptive machining system lies in trying to operate the process

more efficiently. The typical measure of performance in machininghave been removal rate cost per volume of metal removed.

Benefits of adaptive control machining: 1. Increased production rates 2. Increased tool life 3. Greater part protection 4. Less operator intervention 5. Easier part programming

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RESPONSIBILITIES OF CNC MACHINE OPERATOR

WHILE EXECUTING THE JOB :

Job loading and setting as per the job layout Program entering manually/ through punched tape / through DNC

/ calling from memory Loading the required cutting tools into the turret / tool magazine as

per the tools layout and entering the tool data into the memory Fixing the work zero with reference to the machine zero Verification of correctness of the program from graphic simulation

if the system allows Machining the job in single mode as per the program. Dimensional

inspection while machining and correction of tool offset ifnecessary. Replacement of inserts, cutting tools whenever required. Optimization of the program i.e. correction of feeds, speeds, idle

movements etc

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mac nes o er e o ow ngadvantages in manufacturing.

Higher flexibility. Increased machine utilization Reduced scrap rate.

Reduced man power. Shorter cycle time. Higher accuracy. Automatic material handling. Lesser floor space. Increased operational safety. Machining of advanced material. Savings in jigs and fixtures

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THANK YOU