MILLING MACHINE PPT 2: PARTS AND CLASSIFICATION OF MILLING MACHINES

MILLING MACHINE PPT 2: PARTS AND CLASSIFICATION OF MILLING MACHINES

1. LENDI INSTITUTE OF ENGINEERING AND TECHNOLOGY METAL CUTTING AND MACHINE TOOLS COURSE CODE: C302 REGULATION: R16 3 rd BTECH 1 st SEM PREPARED BY : POLAYYA CHINTADA M.TECH,M.B.A,(PhD) ASSISTANT PROFESSOR TOPIC : MILLING MACHINES

2. PARTS OF MILLING MACHINES : 2 1. Base It is a foundation member and it carries the column at its one end. In some machines, the base is hollow and serves as a reservoir for cutting fluid. 2. Column The column is the main supporting member mounted vertically on the base. It is box-shaped, heavily ribbed inside and houses all the driving mechanism for the spindle and table feed. The front vertical face of the column is accurately machined and is provided with a dovetail guide way for supporting the knee. 3. Knee The knee is a rigid grey iron casting which slides up and down on the vertical ways of the column face. An elevating screw mounted on the base is used to adjust the height of the knee and it also supports the knee. 4. Saddle The saddle is placed on the top of the knee and it slides on guide ways set exactly at 90° to the column face. The top of the saddle provides guide-ways for the table. 5. Table The table rests on ways on the saddle and travels longitudinally. A lead screw under the table engages a nut on the saddle to move the table horizontally by hand or power. In universal machines, the table may also be swiveled horizontally. For this purpose the table is mounted on a circular base. The top of the table is accurately finished and T -slots are provided for clamping the work and other fixtures on it

3. PARTS OF MILLING MACHINES : 3 6.Overhanging arm It is mounted on the top of the column, which extends beyond the column face and serves as a bearing support for the other end of the arbor. 7. Front brace It is an extra support, which is fitted between the knee and the over-arm to ensure further rigidity to the arbor and the knee. 8. Spindle It is situated in the upper part of the column and receives power from the motor through belts, gears, and clutches and transmit it to the arbor. 9. Arbor It is like an extension of the machine spindle on which milling cutters are securely mounted and rotated. The arbors are made with taper shanks for proper alignment with the machine spindles having taper holes at their nose. The arbor assembly consists of the following components. 1. Arbor 2. Spindle 3. Spacing collars 4. Bearing bush 5. Cutter 6. Draw bolt 7. Locknut 8. Key block 9. Set screw

4. CLASSIFICATION OF MILLING MACHINES : 4 Column and Knee Type Milling Machine Hand Milling Machines HORIZONTAL milling machine (b) Vertical milling machine (c) Universal milling machine (d) Omniversal milling machine Fixed Bed Type Milling Machine (a) Simplex milling (b) Duplex milling (c) Triplex milling (d) Rise and Fall type Planner Type Milling Machine Special purpose Milling Machine Thread milling machine Gear milling machine Cam milling machine Skin milling machine Spar milling machine Double end milling machine Production type Milling Machine (a) Rotary table milling (b) Drum milling (c) Tracer controlled milling

5. Column & knee type OF MILLING MACHINES : 5 HORIZONTAL MILLING MACHINE The horizontal milling machine has a spindle that is parallel to the shop floor and an over arm that extends over the Work piece. • The over arm supports the arbor, which holds the milling cutter. • On the horizontal mill, the arbor is the component that rotates the milling cutter

6. Column & knee type OF MILLING MACHINES : 6 hand MILLING MACHINE

7. 7 VERTICAL MILLING MACHINE  Spindle is vertical or perpendicular to the work table.  It has all the movements of the table for proper setting and feeding the work.  Spindle head may be swiveled at an angle, permitting the milling cutter mounted on the spindle to work on angular surfaces.  In some machines, spindle can also be adjusted up or down relative to the work.  Adopted for machining grooves, slots and flat surfaces. Cutter is directly mounted in the spindle.  used for face and end milling operations Column & knee type OF MILLING MACHINES :

8. 8 Universal MILLING MACHINE A universal milling machine is named so as it is used to do a large variety of operations. this milling machine is it table which is mounted on a circular swiveling base which has degree graduations. The table can be swiveled to any angle up to 45 degrees on either side of normal position. Helical milling operation is possible on universal milling machine as its table can be fed to cutter at an angle. Provision of large number of auxiliaries like dividing head, vertical milling attachments, rotary table, etc. make it suitable for wide variety of operations. Column & knee type OF MILLING MACHINES :

9. 9 Omni versal MILLING MACHINE Omni-versal milling machine is like a universal milling machine with additional feature that its table can be tilted in a vertical plane by providing a swivel arrangement at the knee. This enables it to make taper spiral grooves in reamers, bevel gears, etc. Used for tool room applications. In additional to the movement of the universal milling machine, its knee can be swiveled in a horizontal plane. Suitable for cutting spiral grooves on angular jobs Here the table also has four movements of the universal milling machine. It can also be tilted in a vertical plane by providing a swivel arrangement at the knee. Column & knee type OF MILLING MACHINES :

10. Fixed bed type MILLING MACHINES : 10 Simplex head MILLING MACHINE It is also known as manufacturing type milling machine. Larger and more robust than column and knee type milling machines. Its table is mounted directly on the ways of fixed bed. Used for tool room applications. Table movement is restricted to reciprocation only. Cutter is mounted on the spindle head which can move vertically on the column. Suitable for cutting spiral grooves on angular jobs Used for heavy production work.

11. Fixed bed type MILLING MACHINES : 11 Duplex head MILLING MACHINE

12. Fixed bed type MILLING MACHINES : 12 triplex head MILLING MACHINE

13. PLANNER type MILLING MACHINES : 13 It is a heavy duty milling machine. It consist of four spindles each with its own drive motor. Table movement provides the feed. Used where high MRR is the prime Concern. it has a cross rail capable of being raised or lowered carrying the cutters, their heads, and the saddles, all supported by rigid uprights. There may be a number of independent spindles carrying cutters on the rail as two heads on the uprights. The use of the machine is limited to production work only and is considered ultimate in metal re-moving capacity

14. PRODUCTION type MILLING MACHINES : 14 DRUM TYPE MILLING MACHINE It is a heavy duty production milling machine It consist of two vertical columns mounted on sturdy base Drum is mounted between the columns for holding the work piece Milling heads are mounted vertical columns, carrying horizontal spindles and they are adjustable All cutters in the spindle are face cutters, 2 are finishing cutters and 2 more finishing cutters Drum rotates continuously, work mounted on fixtures on the rear side of the machine First rough machining done at upper cutter and finishing done at bottom cutter

15. PRODUCTION type MILLING MACHINES : 15 rotary TYPE MILLING MACHINE

16. PRODUCTION type MILLING MACHINES : 16 Tracer controlled MILLING MACHINE

17. Y ours : POLAYYA CHINTADA M.TECH,M.B.A,(PhD) ASSISTANT PROFESSOR