Presentation on theme: "Chapter4 - MILLING PROCESS. FIG. 1 Typical parts and shapes produced by various cutting processes."— Presentation transcript:
Chapter4 - MILLING PROCESS
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 spiral right hand spiral Left hand cutter right hand cutter Fig. 5 Left and right hand cutters. Helical Plain Fig. 6 Milling Cutters. a ) Helical b ) Plain
Slab mill Course tooth mill Helical mill Staggered tooth mill Side mill Interloching mill Metal slitting saw Fig. 7 Various types of milling cutters Helical mill (arbor type)
Fig. 8 Various types of end mills Woodruff Keyslot end mill Double-end end mill Two-lip end mill Shell end mill T-slot end mill
Fig. 9 Angle, concave, convex, corner and gear cutters Corner rounding cutter Covex formed cutter Gear tooth cutter Single angle cutterDouble angle cutter Concave formed cutter
Fig. 10 Effect of milling cutter diameter on workpiece travel Large diameter cutter Amount of travel using large diameter cutter Direction of cut Material being removed workpiece Small diameter cutter Amount of travel using small diameter cutter
Fig.11 Tapers used for Milling machine arborrs Fig. 12The standard milling machine arbor Arbor Intermediate arbor support Arbor support Spindle Draw in bolt Milling cutter Journal bearing Arbor nut Fig. 13 Arbor installation
Fig. 18Fig. 18 examples of various vises swivel vise Standard machine table vise The universal vise Fig. 19 The index head and footstock
Fig. 20Fig. 20 Rotary table Fig. 21Fig. 21 Offset boring head 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
Not correct Correct Workpiece Parallel Selection of Parallels Vise Workpiece Centering of workpiece in vise Locating the workpiece at end of vise Fig. 24 correct mounting of workpiece in a vise Strap block Workpiece Vise 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.
Fig. 25 using hold down straps Fig. 2Fig. 26 The indexing plate Brown and Sharpe type Plate I - 15, 16, 17, 18, 19, 20 holes Plate , 23, 27, 29, 31, 33 holes Plate , 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 Shank End mill Fig. 27 Examples of Milling Cutters and Operations d) e)
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.
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. f v v (a) (b)
TABLE 1 Typical capacities and maximum workpiece dimensions for milling machines Machine toolMaximum dimension m (ft) Power (kW) Maxi mum speed Milling machines (table travel) Knee-and- column 1.4 (4.6) rpm Bed4.3 (14) Numerical control 5 (16.5) Note: Larger capacities are available for special applications.
TABLE 1 Parameters and formulae of the milling process 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 =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 MRR =mm 3 /min or in. 3 /min =w d v, where w is the width of cut Torque =N-m or lb-ft ( F c ) (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. 31Fig. 31 A typical setup for plain milling Fig. 32Fig. 32 is a typical example of angular milling. Fig. 33Fig. 33 Straddel milling of a hexagon Fig. 3Fig. 34 Face milling
Fig. 35Fig. 35 Face milling of angular surfaces Fig. 3Fig. 36 Gange milling. Fig. 37Fig. 37 Form milling
FigFig. 38 Fly cutting tools Fig. 39Fig. 39 The Woodruff key slot milling cutter Key is milled to required length Cutter centered over the shaft Fig. 40 Milling rounded end key slot waysKey is milled to required length
Fig. 41Fig. 41 T-slot milling cutter Fig. 42Fig. 42 Parting of a solid stock Fig. 43Fig. 43 The splines are cut by straddle milling