Machine Tools MILLING PROCESS. BY LAKSHMIPATHI YERRA Asst.professor Dept.of Mechanical Engg.

Size: px

Start display at page:

Download "Machine Tools MILLING PROCESS. BY LAKSHMIPATHI YERRA Asst.professor Dept.of Mechanical Engg."

Mildred Copeland
6 years ago
Views:

1 Machine Tools MILLING PROCESS BY LAKSHMIPATHI YERRA Asst.professor Dept.of Mechanical Engg.

2 FIG. 1 Typical parts and shapes produced by various cutting processes

3 Fig. 2 Schematic illustration of milling machines

4 Fig. 3 Milling machines

6 Fig 4 Nomenclature of a common milling cutter

7 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

8 Slab mill Helical mill Course tooth mill Helical mill (arbor type) Staggered tooth mill Side mill Interloching mill Metal slitting saw Fig. 7 Various types of milling cutters

9 Two-lip end mill T-slot end mill Shell end mill Double-end end mill Woodruff Keyslot end mill Fig. 8 Various types of end mills

10 Corner rounding cutter Covex formed cutter Gear tooth cutter Single angle cutter Double angle cutter Concave formed cutter Fig. 9 Angle, concave, convex, corner and gear cutters

11 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

12 Fig. 12The standard milling machine arbor Spindle Arbor Intermediate arbor support Arbor support Fig.11 Tapers used for Milling machine arborrs Draw in bolt Milling cutter Journal bearing Arbor nut Fig. 13 Arbor installation

13 Fig. 14 Typical milling arbors

14 Fig. 15 Typical Collet types Milling machine adapters Fig. 16 Adapters Chuck adapter Fig. 17 Quick change adapter and tool holder.

15 Standard machine table vise swivel vise Fig. 18 examples of various vises The universal vise Fig. 19 The index head and footstock

16 Fig. 21 Offset boring head Fig. 20 Rotary table Angle plate V-Block and clamp V-clamp C- clamp Step block Bent tail machine clamp Finger machine clamp Strap clamp C- clamp Fig.22 Various mounting tools

17 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 Workpiece Vise Correct Workpiece Parallel Selection of Parallels Vise Parallel Workpiece Workpiece Centering of workpiece in vise Vise Workpiece Locating the workpiece at end of vise Strap block Fig. 24 correct mounting of workpiece in a vise

18 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

19 a) Slab milling b) Face milling c) End milling Cutter Arbor Spindle Spindle End mill Shank Arbor d) e) Fig. 27 Examples of Milling Cutters and Operations

20 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.

21 (a) (b) v f v Fig. 29 (a) Slab milling operation, showing depth of cut, d, feed per tooth, f, chip depth of cut, t c, and workpiece speed, v. (b) Schematic illustration of cutter travel distance l c to reach full depth of cut.

22 TABLE 1 Typical capacities and maximum workpiece dimensions for milling machines Machine tool Milling machines (table travel) Knee-andcolumn Maximum dimension m (ft) Bed 4.3 (14) Numerical control Power (kw) Maxi mum speed 1.4 (4.6) rpm 5 (16.5) Note: Larger capacities are available for special applications.

23 N = Rotational speed of the milling cutter, rpm 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 MRR = Torque = Power = =D N 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+l c ) v, where l c =extent of the cutter s first contact with workpiece mm 3 /min or in. 3 /min =w d v, where w is the width of cut N-m or lb-ft ( F c ) (D/2) kw or hp = (Torque) ( ), where = 2 N radians/min TABLE 1 Parameters and formulae of the milling process Note: The units given are those that are commonly used; however, appropriate units must be used in the formulas.

24 Fig. 31 A typical setup for plain milling Fig. 33 Straddel milling of a hexagon Fig. 32 is a typical example of angular milling. Fig. 34 Face milling

25 Fig. 35 Face milling of angular surfaces Fig. 36 Gange milling. Fig. 37 Form milling

26 Cutter centered over the shaft Fig. 38 Fly cutting tools Key is milled to required length Fig. 39 The Woodruff key slot milling cutter Fig. 40 Milling rounded end key slot wayskey is milled to required length

27 Fig. 41 T-slot milling cutter Fig. 42 Parting of a solid stock Fig. 43 The splines are cut by straddle milling

CHAPTER 23 Machining Processes Used to Produce Various Shapes Kalpakjian Schmid Manufacturing Engineering and Technology 2001 Prentice-Hall Page 23-1

CHAPTER 23 Machining Processes Used to Produce Various Shapes Manufacturing Engineering and Technology 2001 Prentice-Hall Page 23-1 Examples of Parts Produced Using the Machining Processes in the Chapter