INDUSTRIAL TRAINING PRESENTATION

ON “CNC MACHINES”

By:Kavindra Singh NikhurpaECE-A, 4th year120070102058

Introduction to BHEL Introduction to CNC Machines History of CNC Machines Elements of a CNC System Block diagram of CNC Machine Control Systems Modes of Operation Advantages of CNC Machines Challenges Conclusion

Contents

Bharat Heavy Electricals Limited is power plant equipment manufacturer based in New Delhi, India

It was established in 1964 It has a network of 17 manufacturing units It manufactures gas turbines, steam

turbines, generators and boilers It is 7th largest power plant equipment

manufacturer in the world

Introduction to BHEL

Definition:A Computer Numerical Control system is aSystem in which actionsare controlled by directinsertion of numerical data at some point

Introduction to CNC MachinesDisplay

Slide

Numerical control for machine tool was first introduced in the 1950s by Prof. John T Parson

First CNC machine was built at Massachusetts Institute of Technology in 1953

History of CNC Machines

A CNC system consist of following 6 major elements: Input Device Machine Control Unit Machine Tool Driving System Feedback Devices Display Unit

Elements of a CNC System

Input Devices: Floppy Disk Drive USB Flash Drive Serial Communication

Machine Control Unit: Data Processing Unit Control Loop Unit

Driving System: DC Servo Motor AC Servo Motor Stepping Motor

Feedback Devices: Positional Feedback Devices• Linear Transducer• Rotary Encoder

Velocity Feedback Device

Display Unit: Shows position of machine slide, part

programmes etc. Can also show graphics simulation of tool path so

that part programmes may be verified

Block diagram of CNC Machine

Control Systems

In open loop systems, the slide may overshoot or may not reach desired position because of inertia, wear and tear and friction, hence inaccurate machining.

In closed loop systems, the position sensors are used to correct slide movements and achieve higher accuracy and repeatability

Manual Mode Manual Data Input Mode Automatic Mode Reference Mode Input Mode and Output Mode

Modes of Operation

Higher flexibility Increased productivity Consistent quality Reliable operation Reduced manpower High accuracy Increased operation safety

Advantages of CNC Machines

Costly setup, skilled operators required Programming knowledge required Maintenance is difficult

Challenges

The advantage of a CNC system are that the operation of a conventional machine is removed and the part production is made automatic

It reduces the labor work and hence highly efficient in the manufacturing process.

BHEL generally uses CNC machines to achieve its manufacturing targets. For manufacturing works of large scale it is very difficult to work with manual machines as they are time consuming

CNC machines have their wide scope because they are easy to handle, the work becomes easier and jobs are done with perfection

Conclusion

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