SECTION-A(i) Introduction to Machine T ools

1. SECTION-A(i)Introduction to Machine Tools For more info. : www.goodwisher.com

2. Syllabus(ME-101-F) • Section-A • Introduction to machine tools • Basic Concepts of thermodynamics • Properties of steam & steam generators • Section-B • Refrigeration & Air conditioning. • Hydraulic turbines & pumps. • Section-C • Power transmission methods & devices • Stresses & strains • Section-D • Introduction to manufacturing system(NC & CNC Machining) For more info. : www.goodwisher.com

3. Topics • Lathe • Shaper • Planer • Milling • Drilling • Slotter • Introduction to Metal Cutting. For more info. : www.goodwisher.com

4. Introduction to metal cutting • Metal cutting:- • Metal cutting or machining is a process of producing a job by removing a layer of unwanted material from a given workpiece. • A sharp edged tool is set to a certain depth of cut & moves relative to the workpiece causing compression near the tip of the tool. • All machining processes involves the formation of chips ; this occurs by deforming the workpiece on the surface of job with the help of a cutting tool. For more info. : www.goodwisher.com

5. Types of chips • There are three types of chips • Continuous chips. • Discontinuous chips. • Continuous chips with built up edge. For more info. : www.goodwisher.com

6. Continuous chips. • While machining ductile materials , large plastic deformation of the workpiece occurs ahead of the cutting edge of tool. • The metal of the workpiece is compressed & slides over the tool face in the form of a long continuous chips. • Such chips coil in helix & curl around the work & tool • They are likely to injure the operator , when break loose. • For convenience , the continuous chips are broken by using a chip breaker. For more info. : www.goodwisher.com

7. Discontinuous chips • This type of chip is a segmented chip produced in the form of small pieces. • The discontinuous chips are produced when cutting brittle materials like cast iron,bronze & brass. • Working on ductile materials under poor condition may also sometimes lead to formation of discontinous chips. For more info. : www.goodwisher.com

8. Continuous chips with built-up-edge • The term built up edge refers to the small metal particle that sticks to the cutting tool & machined surface as a result of high temperature , high pressure & high frictional resistance during machining. For more info. : www.goodwisher.com

9. Cutting operations • There are two types of cutting operations: • Orthogonal cutting • Oblique cutting For more info. : www.goodwisher.com

10. Orthogonal cutting • In orthogonal cutting:- • Cutting edge of the tool is perpendicular to the workpiece. • The cutting edge of the tool clears the width of workpiece on the entire ends. • The chip flows over the tool face and the direction of the chip flow velocity is normal to the cutting edge. For more info. : www.goodwisher.com

11. Oblique cutting • The cutting edge is inclined with the workpiece by a certain angle called the inclination angle. • The cutting edge may not clear the width of the workpiece • The chip flows on the tool face at an angle with normal to the cutting edge. For more info. : www.goodwisher.com

12. Types of tools • There are two types of tools. • SINGLE POINT CUTTING TOOL. • MULTI POINT CUTTING TOOL. For more info. : www.goodwisher.com

13. SINGLE POINT CUTTING TOOL • The tool has only one cutting edge. • These tools are mostly used on lathes , shapers & planers. For more info. : www.goodwisher.com

14. Multi point cutting tool • The tool has more than one cutting edge. • The milling cutter used in a milling operation is a multi point tool. • The tool has cutting teeth on its periphery. • During the machining process , cutting action of each tooth occurs independently on the workpiece. • The tool used for drilling is an another example of multi point cutting tool. For more info. : www.goodwisher.com