Milling Machines

Views:
 
     
 

Presentation Description

No description available.

Comments

Presentation Transcript

PowerPoint Presentation:

INTRODUCTION A milling machine is a machine tool that removes metal as the work is fed against a rotating multipoint cutter. The milling cutter rotates at high speed and it removes metal at a very fast rate with the help of multiple cutting edges. One or more number of cutters can be mounted simultaneously on the arbor of milling machine. This is the reason that a milling machine finds wide application in production work. Milling machine is used for machining flat surfaces, contoured surfaces, surfaces of revolution, external and internal threads, and helical surfaces of various cross-sections. In many applications, due to its higher production rate and accuracy, milling machine has even replaced shapers and slotters Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

PRINCIPLE OF MILLING In milling machine, the metal is cut by means of a rotating cutter having multiple cutting edges. For cutting operation, the workpiece is fed against the rotary cutter. As the workpiece moves against the cutting edges of milling cutter, metal is removed in form chips of trochoid shape. Machined surface is formed in one or more passes of the work. The work to be machined is held in a vice, a rotary table, a three jaw chuck, an index head, between centers , in a special fixture or bolted to machine table. The rotatory speed of the cutting tool and the feed rate of the workpiece depend upon the type of material being machined. Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

SIZE OF MILLING MACHINE The size of the column and knee type milling machine is specified by (1) The dimensions of the working surface of the table, and (2) Its maximum length of longitudinal, cross and vertical travel of the table. In addition to above, number of spindle speeds, number of feeds, spindle nose taper, power available, floor space required and net weight of machine will also be required for additional specification. Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

TYPES OF MILLING MACHINES Milling machine rotates the cutter mounted on the arbor of the machine and at the same time automatically feed the work in the required direction. The milling machine may be classified in several forms, but the choice of any particular machine is determined primarily by the size of the workpiece to be undertaken and operations to be performed. With the above function or requirement in mind, milling machines are made in a variety of types and sizes. 1. Column and knee type milling machines ( a) Hand milling machine ( b) Horizontal milling machine ( c) Universal milling machine ( d) Vertical milling machine Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

2. Planer milling machine 3. Fixed-bed type milling machine ( a) Simplex milling machine. ( b) Duplex milling machine. ( c) Triplex milling machine. 4. Machining center machines 5. Special types of milling machines ( a) Rotary table milling machine. ( b) Planetary milling machine. ( c) Profiling machine. ( d) Duplicating machine. ( e) Pantograph milling machine. ( f) Continuous milling machine. ( g) Drum milling machine ( h) Profiling and tracer controlled milling machine Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Column and Knee Type Milling Machine Fig. shows a simple column and knee type milling machine. It is the most commonly used milling machine used for general shop work. In this type of milling machine the table column. The knee is vertically adjustable on the column so that the table can be moved up and down to accommodate work of various heights. The column and knee type milling machines are classified on the basis of various methods of supplying power to the table, different movements of the table and different axis of rotation of the main spindle. Column and knee type milling machine comprises of the following important parts- 1. Base 2. Column 3. Saddle 4. Table 5. Elevating screw 6. Knee 7. Knee elevating handle 8. Cross feed handle 9. Front brace 10. Arbor support 11. Arbor 12. Overhanging arm 13. Cutter 14. Cone pulley 15. Telescopic feed shaft. Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Base It is a foundation member for all the other parts, which rest upon it. It carries the column at its one end. In some machines, the base is hollow and serves as a reservoir for cutting fluid. 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 dovetail guideway for supporting the knee. 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. The knee houses the feed mechanism of the table, and different controls to operate it. Saddle The saddle is placed on the top of the knee and it slides on guideways set exactly at 90° to the column face. The top of the saddle provides guide-ways for the table. Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

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 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 . 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. Spindle It is situated in the upper part of the column and receives power from the motor throughbelts , gears. and clutches and transmit it to the arbor . Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

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 draw bolt is used for managing for locking the arbor with the spindle and the whole assembly. The arbor assembly consists of the following components. 1. Arbor 2. Spindle 3. Spacing collars 4. Bearing bush 5. Cutter 6. Draw bolt 7. Lock nut 8. Key block 9. Set screw Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg .)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

INDEXING AND DIVIDING HEADS Indexing is the operation of dividing the periphery of a piece of work into any number of equal parts. In cutting spur gear equal spacing of teeth on the gear blank is performed by indexing. Indexing is accomplished by using a special attachment known as dividing head or index head as shown in Fig. The dividing heads are of three types: (1) Plain or simple dividing head, (2) Universal dividing head and (3) Optical dividing head Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Plain or Simple Dividing Head The plain dividing head comprises a cylindrical spindle housed on a frame, and a base bolted to the machine table. The index crank is connected to the tail end of the spindle directly, and the crank and the spindle rotate as one unit. The index plate is mounted on the spindle and rotates with it. The spindle may be rotated through the desired angle and then clamped by inserting the clamping lever pin into anyone of the equally spaced holes or slots cut on the periphery of the index plate. This type of dividing head is used for handling large number of workpieces , which require a very small number of divisions on the periphery. Swiveling block Live centre Index crank Index plate. Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

24.9 OPERATIONS PERFORMED ON MILLING MACHINE Unlike a lathe, a milling cutter does not give a continuous cut, but begins with a sliding motion between the cutter and the work. Then follows a crushing movement, and then a cutting operation by which the chip is removed. Many different kinds of operations can be performed on a milling machine but a few of the more common operations will now be explained. These are: Plain milling or slab milling Fig. 24.9(a) illustrates the plain and slab milling operation. It is a method of producing a plain, flat, horizontal surface parallel to the axis of rotation of the cutter. Face milling Fig. 24.9(b) illustrates the face milling operation. It is a method of producing a flat surface at right angles to the axis of the cutter. Side milling Fig. 24.9(c) illustrates the side milling operation. It is the operation of production of a flat vertical surface on the side of a work-piece by using a side milling cutter. Angular milling Fig. 24.9(d) illustrates angular milling operation. It is a method of producing a flat surface making an angle to the axis of the cutter. Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Gang-milling Fig. 24.9(e) illustrates the gang milling operation. It is a method of milling by means of two or more cutters simultaneously having same or different diameters mounted on the arbor of the milling machine. Form milling Fig. 24.9(f) illustrates the form milling operation. It is, a method of producing a surface having an irregular outline. End milling Fig. 24.9(g) illustrates end milling operation. It is a method of milling slots, flat surfaces, and profiles by end mills. Profile milling Fig. 24.9(h) illustrates profile milling operation. It is the operation of reproduction of an outline of a template or complex shape of a master die on a workpiece . Saw milling Fig. 24.9( i ) illustrates saw milling operation. It is a method of producing deep slots and cutting materials into the required length by slitting saws. Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

T-slot milling Fig. 24.9(j) illustrates T-slot milling operation. Keyway milling Fig. 24.9(k) illustrates keyway milling operation. Gear cutting milling Fig. 24.9(l) illustrates gear cutting milling operation. Helical milling Fig. 24.9(m) illustrates helical milling operation. Flute milling It is a method of grooving or cutting of flutes on drills, reamers, taps, etc, Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

PowerPoint Presentation:

Rattandeep singh (Mechanical engg.)Email:-rsrattanvirdi@gmail.com contact no 9876866320

authorStream Live Help