METAL CUTTING AND MACHINE TOOLS 1st Lecture : INTRODUCTION ASIMAVA ROY CHOUDHURY MECHANICAL ENGINEERING IIT KHARAGPUR
1
INTRODUCTION What is metal cutting ?
part
feed
tool
Removal of material from a part in the form of chips so as to attain a final desired shape and size
FACULTY NAME DEPARTMENT NAME IIT KHARAGPUR
2
INTRODUCTION Attaining shape and size : Manufacturing There are various other methods of manufacturing Manufacturing methods : Casting, Forming, welding, Conventional machining, Non‐conventional machining, Rapid prototyping
FACULTY NAME DEPARTMENT NAME IIT KHARAGPUR
3
INTRODUCTION Metal cutting : Cutting tool, work piece, fixture, relative motion, operator
Sharp, wedge‐shaped cutting tool; Htool > Hw/p ; Set‐up for rigidly holding tool‐work piece pair and providing relative motion between them FACULTY NAME DEPARTMENT NAME IIT KHARAGPUR
4
INTRODUCTION Part / Job / work piece rotates
Chip comes out
Cutting tool
INTRODUCTION A typical single point turning tool
Planes, edges and points
FACULTY NAME DEPARTMENT NAME IIT KHARAGPUR
6
INTRODUCTION Machine tool : Set‐up for rigidly holding tool‐work piece pair and providing relative motion between them
Examples of machine tools : Lathe, Milling machine, Shaping machine, Grinding machine, Drilling machine
FACULTY NAME DEPARTMENT NAME IIT KHARAGPUR
7
8
METAL CUTTING AND MACHINE TOOLS 2ND LECTURE: GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 ASIMAVA ROY CHOUDHURY MECHANICAL ENGINEERING IIT KHARAGPUR
1
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 A typical single point turning tool (SPTT) is considered as the basic cutting tool in machining
SPTT Rake surface
Planes – Rake surface, Principal flank and Auxiliary flank
Aux. flank Pr. flank
A Roy Choudhury Mech Engg IIT KHARAGPUR
2
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 Machine tool : Set‐up for rigidly holding tool‐work piece pair and providing relative motion between them
Examples of machine tools : Lathe, Milling machine, Shaping machine, Grinding machine, Drilling machine
FACULTY NAME DEPARTMENT NAME IIT KHARAGPUR
3
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 Rake surface is that over which the chips flow Principal flank faces the unfinished part surface, Aux. flank faces the finished part surface
Rake surface
Tool‐in‐ hand system
Aux. flank Pr. flank
A Roy Choudhury Mech Engg IIT KHARAGPUR
4
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 The principal cutting edge is the intersection of Rake surface and Pr. flank Aux. Cutting edge
The auxiliary cutting edge is the intersection of Rake surface and Aux. flank Tool nose
Rake surface
Tool in hand system
Aux. flank Pr. flank Pr. Cutting edge
FACULTY NAME DEPARTMENT NAME IIT KHARAGPUR
5
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1
Machine reference system : Planes, angles and edges of a tool placed in the coordinate system of a machine tool
Z
Y
X
Machine horizontal plane πxy Machine longitudinal
American system of tool nomenclature uses these angle definitions
plane πx
SPTT Machine transverse plane πy
FACULTY NAME DEPARTMENT NAME IIT KHARAGPUR
6
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1
γx
Machine reference system : Planes, angles and edges of a tool placed in the coordinate system of a machine tool αx γy : Back rake angle γx : Side rake angle αy : Back clearance αx : Side clearance фs : Approach angle фe : End Cutting Edge Angle
πx Auxiliary Cutting edge
Principal Cutting edge
фe фs
American system of tool nomenclature uses these angle definitions
αy
γy πy
πxy FACULTY NAME DEPARTMENT NAME IIT KHARAGPUR
7
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1
Orthogonal rake system : System of tool nomenclature based on the plane of cut.
Z, Vc Cutting plane πc
Y
Reference plane πR
X
Reference plane, Cutting plane, orthogonal plane,
Orthogonal plane πo SPTT
FACULTY NAME DEPARTMENT NAME IIT KHARAGPUR
8
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1
Orthogonal rake system : Planes, angles and edges of a tool placed in the coordinate system of a machine tool πR : Reference plane πC : Cutting plane πo : Orthogonal plane γo : Orthogonal rake λ : Inclination angle αo : Orthogonal clearance αo’ : Aux. Orthogonal clearance ф : Principal cutting edge angle ф1 : End Cutting Edge Angle
λ
ф ф1
πc
πR FACULTY NAME DEPARTMENT NAME IIT KHARAGPUR
9
10
METAL CUTTING AND MACHINE TOOLS 3rd LECTURE: GEOMETRY OF SINGLE POINT TURNING TOOLS - 2 ASIMAVA ROY CHOUDHURY MECHANICAL ENGINEERING IIT KHARAGPUR
1
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 Z, Vc
Normal rake system : System of tool
Orthogonal
nomenclature based on the plane of cut.
Y
plane πo
Reference
X
Reference plane, Cutting plane, orthogonal plane,Normal plane
λ
plane πR
SPTT Cutting plane πc
Normal plane πn
ASIMAVA ROY CHOUDHURY MECHANICAL ENGG 2 IIT KHARAGPUR
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1
Normal rake system : Planes, angles and edges of a tool placed in the coordinate system of a machine tool πR : Reference plane πC : Cutting plane πo : Orthogonal plane γo : Orthogonal rake λ : Inclination angle αo : Orthogonal clearance αo’ : Aux. Orthogonal clearance ф : Principal cutting edge angle ф1 : End Cutting Edge Angle
λ
ф ф1
πc
πR ASIMAVA ROY CHOUDHURY MECHANICAL ENGG 3 IIT KHARAGPUR
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 This image cannot currently be display ed.
γx
S tan x B tan y O tan o
αx S ф
O
αy B
cos 1 tan x sin 1 tan y tan o
γy
ASIMAVA ROY CHOUDHURY MECHANICAL ENGG IIT KHARAGPUR
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 This image cannot currently be display ed.
γx
O tan S tan x B tan y
αx O
B
αx
S tan sin 1 tan x cos 1 tan y
γy
ASIMAVA ROY CHOUDHURY MECHANICAL ENGG IIT KHARAGPUR
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 This image cannot currently be display ed.
L tan O tan o B tan y λ
αy ф ф1
πc
γy
tan cos 1 sin 1 tan o tan y πR
ASIMAVA ROY CHOUDHURY MECHANICAL ENGG IIT KHARAGPUR
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 This image cannot currently be display ed.
γx
L tan S cot x B cot y
αx L
B
αy
S tan cos cot x sin cot y
ASIMAVA ROY CHOUDHURY MECHANICAL ENGG IIT KHARAGPUR
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 This image cannot currently be display ed.
L tan O cot o B cot y λ
ф ф1
πc
αy
tan sin cos cot o cot y πR ASIMAVA ROY CHOUDHURY MECHANICAL ENGG IIT KHARAGPUR
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 This image cannot currently be display ed.
L tan B cot x O cot o λ πc
tan cos cot x sin cot o
αx ф L ф1
B
πR ASIMAVA ROY CHOUDHURY MECHANICAL ENGG IIT KHARAGPUR
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1
L
ф
L tan ' O cot 'o B cot ' x
B
ф1
cot ' x sin 1 cot 'o tan ' cos 1 πR
10
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1
Let us do this ourselves cot ' y cos 1 cot 'o tan ' sin 1
11
ASIMAVA ROY CHOUDHURY MECHANICAL ENGG IIT KHARAGPUR 12
METAL CUTTING AND MACHINE TOOLS 4th LECTURE: DIFFERENT TYPES OF CUTTING TOOLS ASIMAVA ROY CHOUDHURY MECHANICAL ENGINEERING IIT KHARAGPUR
1
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 This image cannot currently be display ed.
L tan O cot o B cot y λ
ф ф1
πc
αy
tan sin cos cot o cot y πR ASIMAVA ROY CHOUDHURY MECHANICAL ENGG IIT KHARAGPUR
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1 This image cannot currently be display ed.
L tan B cot x O cot o λ πc
tan cos cot x sin cot o
αx ф L ф1
B
πR ASIMAVA ROY CHOUDHURY MECHANICAL ENGG IIT KHARAGPUR
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1
L
ф
L tan ' O cot 'o B cot ' x
B
ф1
cot ' x sin 1 cot 'o tan ' cos 1 πR
4
GEOMETRY OF SINGLE POINT TURNING TOOLS - 1
Let us do this ourselves cot ' y cos 1 cot 'o tan ' sin 1
5
ASIMAVA ROY CHOUDHURY MECHANICAL ENGG 6 IIT KHARAGPUR
METAL CUTTING AND MACHINE TOOLS 5th LECTURE: DIFFERENT CUTTING TOOLS NUMERICAL PROBLEMS, ASIMAVA ROY CHOUDHURY MECHANICAL ENGINEERING IIT KHARAGPUR
1
TOPIC NAME αx
The master lines for rake and clearance ф
tan max tan x tan y 2
2
фα
γx
1
фγ
αy γy
tan x tan tan y 1
ASIMAVA ROY CHOUDHURY MECHANICAL ENGINEERING 2 IIT KHARAGPUR
TOPIC NAME αx
The master lines for rake and clearance ф
фα
γx
1
фγ
1 1 1 cot x cot y cot cos cot y cot y cot sin 2 2 2 ASIMAVA ROY CHOUDHURY MECHANICAL ENGINEERING 3 IIT KHARAGPUR
TOPIC NAME Inclination angle of the main cutting edge is 00 and Orthogonal rake is 7.50. Principal cutting edge angle = 750 and auxiliary cutting edge angle = 150. Auxiliary inclination angle is (in degrees) a.5 b. 7.5 c. 2.5 d. 3.74
ASIMAVA ROY CHOUDHURY MECHANICAL ENGINEERING 4 IIT KHARAGPUR
TOPIC NAME In a single point turning tool, the orthogonal rake angle is equal to the normal rake angle. In that case, a. The inclination angle must be necessarily zero b. The inclination angle must be necessarily non‐zero c. The orthogonal rake must be necessarily zero d. None of these
ASIMAVA ROY CHOUDHURY MECHANICAL ENGINEERING 5 IIT KHARAGPUR
TOPIC NAME In a single point turning tool, the principal cutting edge angle is 900. In that case
a. The orthogonal rake angle and the back rake angle are necessarily equal b. The normal rake angle and the side rake angle are necessarily equal c. The orthogonal rake angle is necessarily zero d. The orthogonal rake angle and the side rake angle are necessarily equal
ASIMAVA ROY CHOUDHURY MECHANICAL ENGINEERING 6 IIT KHARAGPUR
ASIMAVA ROY CHOUDHURY MECHANICAL ENGG 7 IIT KHARAGPUR
