Post on 19-Jan-2016
description
Machine tools
• Machine which performs the material removal operation with tools
Lathe
LatheJob is rotatedAnd cutting tool is advanced
shaper
shaper
Tool Reciprocating on a flat surface
Planer
Planer
• Tool remains stationary and work piece reciprocates.
• Used for large jobs
Drilling Machine(Multipoint cutting tool)
Grinding machine
MillingRevolving cutter with many teeth (multi
point) having a cutting edge each
sawing
Machine tools• Lathe• Shapers• Planers• Drilling• Grinding• Milling• Sawing
We will discuss• Lathe• Shapers• Planers• Drilling• Grinding• Milling• Sawing
We will also discuss
• Mechanics of chip formation• Types of chips
• Cutting fluids
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading• Knurling
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading• Knurling
Lathe O
perations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading• Knurling
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading• Knurling
Lathe Operations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading• Knurling
Lathe O
perations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading• Knurling
Lathe O
perations• Centering• Facing• Plain turning• Step Turning• Taper Turning• Drilling• Reaming• Boring• Undercutting or grooving• Threading• Knurling
Mechanism of Chip formation
Proc
ess
of C
hip
form
ation
Proc
ess
of C
hip
form
ation
Continuous DiscontinuousProduced while machining brittle metalsHigh cutting speedLarge depth of cutLarge rake anglesLack of effective fluids will produceEase of handlingGood surface finishHeat Produced in the chip is carried awayTool life
Continuous DiscontinuousProduced while machining brittle metals
No Yes
High cutting speedLarge depth of cutLarge rake anglesLack of effective fluids will produceEase of handlingGood surface finishHeat Produced in the chip is carried awayTool life
Continuous DiscontinuousProduced while machining brittle metals
No Yes
High cutting speed Yes NoLarge depth of cutLarge rake anglesLack of effective fluids will produceEase of handlingGood surface finishHeat Produced in the chip is carried awayTool life
Continuous DiscontinuousProduced while machining brittle metals
No Yes
High cutting speed Yes NoLarge depth of cut No YesLarge rake anglesLack of effective fluids will produceEase of handlingGood surface finishHeat Produced in the chip is carried awayTool life
Continuous DiscontinuousProduced while machining brittle metals
No Yes
High cutting speed Yes NoLarge depth of cut No YesLarge rake angles Yes NoLack of effective fluids will produceEase of handlingGood surface finishHeat Produced in the chip is carried awayTool life
Continuous DiscontinuousProduced while machining brittle metals
No Yes
High cutting speed Yes NoLarge depth of cut No YesLarge rake angles Yes NoLack of effective fluids will produce
No Yes
Ease of handlingGood surface finishHeat Produced in the chip is carried awayTool life
Continuous DiscontinuousProduced while machining brittle metals
No Yes
High cutting speed Yes NoLarge depth of cut No YesLarge rake angles Yes NoLack of effective fluids will produce
No Yes
Ease of handling Less MoreGood surface finishHeat Produced in the chip is carried awayTool life
Continuous DiscontinuousProduced while machining brittle metals
No Yes
High cutting speed Yes NoLarge depth of cut No YesLarge rake angles Yes NoLack of effective fluids will produce
No Yes
Ease of handling Less MoreGood surface finish ? ?Heat Produced in the chip is carried awayTool life
Continuous DiscontinuousProduced while machining brittle metals
No Yes
High cutting speed Yes NoLarge depth of cut No YesLarge rake angles Yes NoLack of effective fluids will produce
No Yes
Ease of handling Less MoreGood surface finish ? ?Heat Produced in the chip is carried away
No Yes
Tool life
Continuous DiscontinuousProduced while machining brittle metals
No Yes
High cutting speed Yes NoLarge depth of cut No YesLarge rake angles Yes NoLack of effective fluids will produce
No Yes
Ease of handling Less MoreGood surface finish ? ?Heat Produced in the chip is carried away
No Yes
Tool life ? ?
Factors responsible for Built-up Edge
• Excessive Pressure at the cutting edge• Machining of ductile materials with high
friction• rake angle• cutting speed• depth of cut• Blunt tool• High friction at tool chip interface
Continuous Chips with Built-up Edge
• Excessive Pressure at the cutting edge• Machining of ductile materials with high
friction• Low rake angle• Low cutting speed• Large depth of cut• Blunt tool• High friction at tool chip interface
BUE can be desirable because ?
BUE can be desirable because ?
A thin and stable BUE protects tool surface and reduces wear
BUE can be undesirable because ?
BUE can be undesirable because ?
Inferior surface finish
Cutting fluids
Cutting fluid advantages
• Lubrication – reduces friction• Absorbs and carriages away the generated
heat.• Washes away chips and any dust during
process.• Carry away the BUE• Prevent corrosion of the machined surface,
tool and machine
Disadvantages
Disadvantages
It cost to have pumps, filters, coolant tank etc
Disadvantages
Skin allergy
Disadvantages
Disadvantages
Corrosion
Disadvantages
Disadvantages
Flammable and can cause fire hazards
Principal parts of lathe
• Bed• Headstock• Tailstock• Carriage• Feed Mechanisms