Download Chapter4 - MILLING PROCESS

MILLING PROCESS
130390119075-PATEL NISHANT P.
GUIDED BY : PROF.R.B.PATEL
BE SEM 3RD MECHANICAL
SUBJECT-MP-I
FIG. 1 Typical parts and shapes produced by various cutting processes
Fig. 2 Schematic illustration of milling machines
Fig. 3 Milling machines
Fig 4 Nomenclature of a common milling cutter
Left hand cutter
right hand cutter
Left hand spiral
right hand spiral
Fig. 5 Left and right hand cutters.
Helical
Plain
Fig. 6 Milling Cutters. a ) Helical b ) Plain
Helical mill
Slab mill
Course tooth mill
Helical mill (arbor type)
Staggered tooth mill
Side mill
Interloching mill
Fig. 7 Various types of milling cutters
Metal slitting saw
Two-lip end mill
Shell end mill
T-slot end mill
Double-end end mill
Fig. 8 Various types of end mills
Woodruff Keyslot end mill
Corner rounding cutter
Covex formed cutter
Single angle cutter
Double angle cutter
Fig. 9 Angle, concave, convex, corner and gear cutters
Gear tooth cutter
Concave formed cutter
Amount of travel using large diameter cutter
Large diameter
cutter
Amount of travel using small diameter cutter
Direction of cut
Material being removed
Small diameter
cutter
workpiece
Fig. 10 Effect of milling cutter diameter on workpiece travel
Fig. 12The standard milling machine arbor
Arbor
Intermediate arbor
support
Arbor support
Spindle
Draw in bolt
Milling cutter
Journal bearing Arbor nut
Fig.11 Tapers used for Milling machine arborrs
Fig. 13 Arbor installation
Fig. 14 Typical milling arbors
Milling machine adapters
Fig. 15 Typical Collet types
Fig. 16 Adapters
Fig. 17 Quick change adapter
and tool holder.
Chuck adapter
Standard machine table vise
swivel vise
The universal vise
Fig. 18 examples of various vises
Fig. 19 The index head and footstock
Fig. 21 Offset boring head
Fig. 20 Rotary table
Angle plate
Step block
C- clamp
V-Block and clamp
Bent tail machine clamp
V-clamp
Finger machine clamp
Fig.22 Various mounting tools
C- clamp
Strap clamp
Fig. 23 locating keys or tongues on the underside
of the vise bases should be located correctly in
relation to the T-slots on the milling machine table
vise.
Not correct
Correct
Workpiece
Vise
Parallel
Parallel
Selection of Parallels
Workpiece
Vise
Workpiece
Centering of workpiece in vise
Workpiece
Vise
Workpiece
Strap block
Locating the workpiece at end of vise
Fig. 24 correct mounting of workpiece in a vise
Fig. 25 using hold down straps
Fig. 26 The indexing plate
Brown and Sharpe type
Plate I - 15, 16, 17, 18, 19, 20 holes
Plate 2 - 21, 23, 27, 29, 31, 33 holes
Plate 3 - 37, 39, 41, 43, 47, 49 holes
Cincinnati type
First side - 24, 25, 28, 30, 34, 37, 38, 39, 41, 42, 43 holes
Second side - 46, 47, 49, 51, 53, 54, 57, 58, 59, 62, 66 holes
a) Slab milling
b) Face milling
c) End milling
Arbor
Cutter
Spindle
Spindle
Shank
End mill
Arbor
d)
e)
Fig. 27 Examples of Milling Cutters and Operations
Fig. 28 Face-milling operation showing (a) action of an insert in
face milling; (b) climb milling; (c) conventional milling; (d)
dimensions in face milling. The width of cut, w, is not
necessarily the same as the cutter radius.
(b)
(a)
f
v
v
Fig. 29 (a) Slab milling operation, showing depth of cut, d,
feed per tooth, f, chip depth of cut, tc, and workpiece
speed, v. (b) Schematic illustration of cutter travel
distance lc to reach full depth of cut.
TABLE 1 Typical capacities and maximum workpiece
dimensions for milling machines
Machine tool
Maximum
dimension
m (ft)
Power
(kW)
Maxi
mum
speed
1.4 (4.6)
20
4000
rpm
Milling machines
(table travel)
Knee-andcolumn
Bed
Numerical
control
4.3 (14)
5 (16.5)
Note: Larger capacities are available for special applications.
= Rotational speed of the milling cutter, rpm
N
f = Feed, mm/tooth or in./tooth
D = Cutter diameter, mm or in.
n = Number of teeth on cutter
v
=
Linear speed of the workpiece or feed rate, mm/min or
in./min
V = Surface speed of cutter, m/min or ft/min
=D N
TABLE 1
Parameters and
formulae of the
milling process
f = Feed per tooth, mm/tooth or in/tooth
=v /N n
l = Length of cut, mm or in.
t = Cutting time, s or min
=( l+lc ) v , where lc =extent of the cutter’s first contact with
workpiece
MRR = mm3/min or in.3/min
=w d v , where w is the width of cut
Torque = N-m or lb-ft
( Fc ) (D/2)
Power = kW or hp
= (Torque) ( ), where  = 2 N radians/min
Note: The units
given are those
that are
commonly used;
however,
appropriate units
must be used in
the formulas.
Fig. 31 A typical setup for plain milling
Fig. 32 is a typical example of angular
milling.
Fig. 33 Straddel
milling of a hexagon
Fig. 34 Face milling
Fig. 35 Face milling of angular surfaces
Fig. 36 Gange milling.
Fig. 37 Form milling
Cutter centered over the shaft
Fig. 38 Fly cutting tools
Key is milled to required length
Fig. 40 Milling rounded end key slot
waysKey is milled to required length
Fig. 39 The Woodruff key slot
milling cutter
Fig. 41 T-slot milling cutter
Fig. 42 Parting of a solid stock
Fig. 43 The splines are cut by straddle
milling