Subject: ADVANCED PRODUCTION PROCESSES &2//(*( Branch

ENGINEERING /TECHNOLOGY OCTOBER 2019
Subject: ADVANCED PRODUCTION PROCESSES
MADIN P
OLY TECHNIC
C OLL
EGE
www.madinpoly.com
I. 1).The definition of automation is the use of machines and technology to make processes run on their
own without manpower. Or automation can be defined as the creation and application of technology to
monitor and control the production and delivery of products and services.
2).Three axis machining centre, Horizontal Three axis machining centre, four axis machining centre, five
axis machining centre, Machining centre with pallet changer
3).1. Gear shaving. 2. Gear burnishing. 3. Gear grinding. 4. Gear lapping, and5. Gear honing
4).Dressing: Dressing is the term used to denote sharpening operation of grinding wheel. The purpose of
dressing is to remove dulled abrasive grains and to improve the cutting action of a grinding wheel. This is
done by wheel dresser.
5).An industrial robot is a reprogrammable, multifunctional manipulator designed to move material, parts,
tools or specialized devices through variable programmed motions to accomplish a variety of tasks'. The
basic elements of robots are:
1. Manipulator 2. Controller 3. Sensors 4. End effectors, and 5. Power source
II. 1).
MADIN P
OLY TECHNIC
C OLL
EGE
www.madinpoly.com
2). 1. The RMS is designed for adjustable production resources to respond to imminent needs.
2. To enhance the speed of responsiveness of a manufacturing system, core RMS characteristics should be
embedded in the whole system as well as in its components.
3. The RMS is designed around a part family, with just enough customized flexibility needed to produce all
parts in that family.
4. The RMS contains an economic equipment mix of flexible and reconfigurable machine tools,
reconfigurable inspection machines, and reconfigurable assembly machines.
5. The RMS possesses hardware and software capabilities to cost effectively respond to unpredictable
events, both external and intrinsic events.
3). PROPERTIES OF CUTTING FLUIDS
1. They should possess good lubricating properties to minimize the friction
2. They should possess high heat absorption .capacity so as to carry away the heat generated.
3. They should present no fire or accidental hazards.
4. They should not cause skin irritation.
5. They should not emit obnoxious odours and vapours harmful to the operator, work piece or surrounding area.
6. They should be of low viscosity to permit free flow, and easy separation from chips collected.
7. They should be transparent, so that an operator can clearly view tool and work; it is very important where high
dimensional accuracy and fine finish are required.
8. They should prevent rusting of the machine sliding and working surfaces.
9. They should be suitable for a variety of cutting operations, and should be easily available at low price so as to
minimize production cost.
10. They should be chemically stable
11. They must possess a law evaporation rate and must not fume.
12. They should not deteriorate in storage.
MADIN P
OLY TECHNIC
C OLL
13. They should have high flash point.
4). Blanking: Blanking is a process of cutting out desired shape from the strip or sheet by a single blow of
the punch. The product of blanking part cut out from sheet is a finished product or may be used for
subsequent cold forming process. The sheet left with a hole on the dies goes as waste. The size of die
determines the size of blanked part and the clearance should be given to the punch. Blanking is usually the
fastest and most economical process to make flat parts, particularly in large quantities.
Piercing-Piercing or punching is a process of making a desired hole by using a punch and die. The
blanked part is a waste and a sheet with a hole left on the dies is a desired product. The size of the punch
determines the size of hole and the clearance should be given to die.
5).Advantages of lapping process:
1. Less heat is generated, and there is no distortion of work surface.
2. Due to low temperature, there are no metallurgical changes in the work materials.
3. The process is suitable for any materials, and can be used for finishing flat or cylindrical surfaces and
holes.
Disadvantages:
1. The process is very slow and metal removal rate is low.
2. Machining allowance for lapping is taken to be 0.005to 0.02 mm.
3. Hand lapping requires high operation skills.
4. Process cost is high and should not be recommended unless very accurate surface is absolutely necessary.
6).Advantages of EDM
MADIN P
OLY TECHNIC
C OLL
2. High degree of surface finish can be obtained.
3. The tool and work are not in contact, and no cutting force acts upon the work.
4. Thin sections can be machined without any distortion.
5. Any complicated shapes can be produced on the work piece.
6. The process is readily adaptable to automatic operation.
7. The process is compatible with CNC control system.
8. EDM may be the only process available for machining some of the more difficult
aerospace alloys.
1. The metal removal rate is low
2. Only suitable for electrically conducting metals.
3. High heat produced at work surface may change the metallurgical properties (structure,
grain size etc)
7). Applications of Robots
2. Machine loading applications
Robot loads the machine with work piece and unloads the finished part.
3 Spray painting applications
6. Assembly of parts
III. a)
MADIN P
OLY TECHNIC
C OLL
EGE
www.madinpoly.com
Bar work in capstan and turret lathes can be processed conveniently by incorporating bar
feed mechanism. The purpose of this mechanism is to fed the bar forward through spindle
to the bar stop when the collect chuck open after completing the first piece
by hand, but one has to stop the machine for feeding the bar and it also wastes a lot of time.
Various types of bar feeding mechanism have been designed to
when the collet opens without stopping the
chuck, lathe spindle and then through the collect chuck. The bar chuck rotates in a sliding
bracket which is mounted on long sliding bar. The weight attached to chain exerts thrust all
the time on bar chuck which is holding the
through the spindle when the collet chuck is released. Thus bar feeding
facilitates to feed the bar without stopping the machine.
III. b)
The hydraulic units are basically servomechanis
force or signal in order to provide a larger output force or signal for operating the
mechanism. This output signal from the
Bar work in capstan and turret lathes can be processed conveniently by incorporating bar
feed mechanism. The purpose of this mechanism is to fed the bar forward through spindle
the bar stop when the collect chuck open after completing the first piece
Various types of bar feeding mechanism have been designed to feed
when the collet opens without stopping the machine. The bar is passed through the bar
the time on bar chuck which is holding the bar by means of two set screws and forces the bar
through the spindle when the collet chuck is released. Thus bar feeding
to feed the bar without stopping the machine.
The hydraulic units are basically servomechanism which magnifies a relatively small input
mechanism. This output signal from the servo mechanism must be continually and
Bar work in capstan and turret lathes can be processed conveniently by incorporating bar-
feed mechanism. The purpose of this mechanism is to fed the bar forward through spindle up
the bar stop when the collect chuck open after completing the first piece. Bar may be fed
the bar immediately
r is passed through the bar
bar by means of two set screws and forces the bar
through the spindle when the collet chuck is released. Thus bar feeding mechanism
m which magnifies a relatively small input
servo mechanism must be continually and
MADIN P
OLY TECHNIC
C OLL
EGE
www.madinpoly.com
automatically modified to suit variations in the input signal .The lathe saddle traverses along
the bed, the stylus will follow the template edge always being kept in contact by spring
pressure on the left-hand end of the valve spool. If the stylus moves to the right then the
spool will move to the right. This will allow the oil to the left of the piston to exhaust, and
will allow oil in to the right of the piston hence moving it to the left. Therefore, the tool slide
and tool will move to the left reproducing the template upon the work piece. The
responsiveness and accuracy of the copying system depend upon the accuracy with which
the spool valve is manufactured. The spool shoulder lengths and port openings must be of a
precise length, and the resistance to oil flow must be identical at any spool position.
IV. A) WORK HOLDING DEVICES:
The work holding devices used on capstan or turret lathes differ slightly from those used in
engine lathe. In turret lathe the work is only supported at the spindle end, and there is no
place for tailstock to support the other end. The following are the devices used to hold the
work on capstan or turret lathes.
1. Collets,
EGE
www.madinpoly.com
1. Collets: Collets are used to grip the bars passing through the headstock spindle. They are
more suitable for mass production because of their quick action and accurate setting. Collets
grip the work by the spring action of its split jaws. They may be operated manually or by
power. The power operated collets are more efficient,
2. Chucks: Chucks are used for the gripping of large sized work which cannot be introduced
through headstock spindle and gripped by collets. Both three-and four jaw chucks are used
on capstan and turret lathes. The three-jaw power operated chuck is widely used on capstan
lathe for production of medium size components form bar stock. The four-jaw chuck is used
occasionally for gripping irregularly shaped work pieces.
MADIN P
OLY TECHNIC
C OLL
EGE
www.madinpoly.com
3. Fixtures: It is used as a holding device when the shape of a
it is difficult to hold it in a spring collet or chuck. Fixture is specially designed to
locate and grip a work piece. It also
pieces.
Three Axis Machining Center: A
plane of the table and a Z axis in the spindle's direction. This is most basic type of machining center.
Typically, three axis machines are in the vertical configuration show above. With thr
machine one surface of a cube with the end of the cutter and
cutter.
It is used as a holding device when the shape of a work
to hold it in a spring collet or chuck. Fixture is specially designed to
piece. It also permits rapid loading and unloading of work
Center: A three axis machining center has programmable X and Y axes in the
Typically, three axis machines are in the vertical configuration show above. With thr
machine one surface of a cube with the end of the cutter and four additional surfaces with the side of the
work piece is such that
to hold it in a spring collet or chuck. Fixture is specially designed to
rapid loading and unloading of work
three axis machining center has programmable X and Y axes in the
Typically, three axis machines are in the vertical configuration show above. With three axes, one can
four additional surfaces with the side of the
MADIN P
OLY TECHNIC
C OLL
Four Axis Machining Center:
rotates to create the fourth axis. Frequently, a fixture called a tombstone is mounted on the table and
many small parts machined at once on a large machine.
the end of the cutter and two additional surfaces with side of the
Center: Four axis machining centers are generally horizontal, and the table
fourth axis. Frequently, a fixture called a tombstone is mounted on the table and
many small parts machined at once on a large machine. One can machine four surfaces of a cube with
the end of the cutter and two additional surfaces with side of the cutter.
centers are generally horizontal, and the table
fourth axis. Frequently, a fixture called a tombstone is mounted on the table and
can machine four surfaces of a cube with
MADIN P
OLY TECHNIC
C OLL
V. a) Horizontal Broaching Machine
The horizontal broaching machine is used for surface broaching or internal broaching, the later being most
common. The work is held in fixture. In the surface broaching the tool (broach)
while for internal broaching the broach is pulled through the work (
are mostly pull type and can be operated at a
- cutting stroke) may be about 30 m/min. Hydraulic horizontal machine has an infinitely variable range of
cutting speed with return speed much greater than the cutting speed. The broach is pu
surface of the work piece held in a fixture. The hydraulic cylinder which pulls the broach is housed in the
right end of the machine.
Broaching Machine :
common. The work is held in fixture. In the surface broaching the tool (broach) is pulled over the surface
while for internal broaching the broach is pulled through the work (i.e. through the hole). These machines
are mostly pull type and can be operated at a cutting speed of 3 to 15 m/min. The speed of return stroke (non
cutting stroke) may be about 30 m/min. Hydraulic horizontal machine has an infinitely variable range of
cutting speed with return speed much greater than the cutting speed. The broach is pu
in a fixture. The hydraulic cylinder which pulls the broach is housed in the
is pulled over the surface
through the hole). These machines
cutting speed of 3 to 15 m/min. The speed of return stroke (non
cutting stroke) may be about 30 m/min. Hydraulic horizontal machine has an infinitely variable range of
cutting speed with return speed much greater than the cutting speed. The broach is pulled over the top
in a fixture. The hydraulic cylinder which pulls the broach is housed in the
MADIN P
OLY TECHNIC
C OLL
V. b)
The gear shaping process is carried on a vertical type shaper. The main parts of gear shaper are shown
above. The blank is mounted upon a vertical arbor, and a pinion cutter fixed to the cutter spindle which is
carried by the saddle. A guide controls the action of the cutter spindle. The saddle can be fed alongside
ways. The cutter spindle and the work spindle are connected to each other through gearing, and the desired
gear ratio between the pinion cutter and blank depends upon the number of teeth on the cutter, and the
number of teeth required on the blank.
MADIN P
OLY TECHNIC
C OLL
In compound die two or more cutting operations are
When the ram descends, the blanking and piercing operations are performed simultaneously. For blanking
operation, the punch used for piercing becomes a die. i.e. blanking is done in opposite direction to that of
piercing. This die is very economical,
parts produced is higher.
VI. b)Flame hardening: The process of flame
an Oxyacetyleneflame.Only a thin layer of the heated surface is brought to the hardening
flame is followed by a stream of cold water which quenches the heated layer
it. Small parts may be heated individually and then quenched. Parts of cylindrical shape may be slowly
In compound die two or more cutting operations are performed at single station in a single
r piercing becomes a die. i.e. blanking is done in opposite direction to that of
piercing. This die is very economical, it leads to savings in floor space and power, and the accuracy of the
process of flame hardening consists of heating the metal surface by using
Oxyacetyleneflame.Only a thin layer of the heated surface is brought to the hardening
flame is followed by a stream of cold water which quenches the heated layer of metal and thereby hardens
parts may be heated individually and then quenched. Parts of cylindrical shape may be slowly
single station in a single stroke of the ram.
r piercing becomes a die. i.e. blanking is done in opposite direction to that of
leads to savings in floor space and power, and the accuracy of the
hardening consists of heating the metal surface by using
Oxyacetyleneflame.Only a thin layer of the heated surface is brought to the hardening temperature. The
of metal and thereby hardens
parts may be heated individually and then quenched. Parts of cylindrical shape may be slowly
MADIN P
OLY TECHNIC
C OLL
EGE
www.madinpoly.com
rotated and heated by exposing their surfaces to the flame of the torch. Parts which may be flame-hardened
successfully include machine tool beds, gears, cams and camshafts. The process is recommended for
medium carbon and low-alloy steels.
Induction hardening: The procedure for induction hardening is the same as flame hardening. But the
high temperature is produced by high frequency alternating current. The surface to be hardened is enclosed
(without contact) in an induction coil. The passage of current through the coil causes induced current to heat
the steel very rapidly to the hardening range, and is immediately followed by spray quenching. The process
of surface hardening by induction is expensive. However, when large quantities of identical parts is to be
surface hardened, this process is economical and efficient. Parts which may be surface hardened by this
process are crankshafts, transmission shafts, camshaft, connecting rods, gears, spindles, cylinders etc.
VII. a)
MADIN P
OLY TECHNIC
C OLL
EGE
www.madinpoly.com
Through- feed grinding: In this type of grinding the work piece has a uniform diameter and is fed
through the wheels which have been set at a fixed. Distance apart to give the correct work diameter. In order
to impart an axial feed to the work piece the control wheel is tilted slightly, generally less than 7degree. It is
used for parallel work of any length which has no surface obstructions.
Infeed grinding: It is a plunge grinding and is used for multi diameter work or any form of work that
cannot be passed completely through the wheels. The work is placed in position against a pre-set end stop.
Control wheel slide advance the rotating work up to the grinding wheel. The control wheel is usually tilted
slightly to hold the work piece
End feed grinding: It is used with the multi diameter work but the length to be ground is too long for
the infeed grinding operation. Feed motion is imparted to work piece until it meets the end stop. Thus it is
combination of infeed and through-feed grinding. This method is mostly used for taper grinding
VII. B) ADVANTAGES OF LASER BEAM MACHINING
1. It can cut all materials
2. No tooling cost because no physical tool is required.
3. It produces finish part or high surface finish.
4. No tool wears because no physical tool is used.
5. Micro holes can be drilled accurately.
6. Complex shapes can be machined easily because laser can be move in any path.
7. Very hard material can be cut through laser beam machining
8. High accuracy can be achieved.
DISADVANTAGES
EGE
www.madinpoly.com
1. It is uneconomical when high volume of same shape to be cut compare to stamping.
2. High capital and maintenance cost
3. It cannot use to produce blind hole
4. Laser can be leads to safety hazards
VIII. a)
MADIN P
OLY TECHNIC
C OLL
The ultrasonic machining uses a magneto strictive type transducer which generates linear vibrations at high
frequency and minimum amplitude. These vibrations are transmitted to the tool by means of mechanical
devices. The mechanical focusing device that provides vibrating motion to tool is called transducer. The tool
moves in the direction of vibrations and forces the abrasive particles on the work piece. These abrasive
particles are mixed with water to form slurry, and the abrasive slurry is continuously circulated between the
tool and work piece until the cutting edges are dull. Due to the impact of abrasive grains on work piece
metal is removed. The form of the tool tip is confined to cavity to be produced in the work piece. The most
commonly used abrasives are boron carbide, silicon carbide and aluminium oxide. Boron carbide is
economical and gives good machining rates. It is also harder than both aluminium oxide and silicon carbide.
The size of abrasive varies between 180 and 200 grit. Metal removal rate is high with coarse grains while
fine grades are used 1or finishing.
VIII. b)
Galvanizing: It is the process of producing the zinc coating on iron or steel by hot-dipping. That is by
immersion of iron or steel articles in molten bath of zinc. For galvanizing, the work surface must be cleaned
by picling and fluxed by immersing the material in a solution of zinc chloride. The flux prevents the
oxidation of surface and assists the formation of good bond between the coating and base metal. After
cleaning, the articles are dipped in a bath of molten zinc maintained at about450°C. In galvanizing the zinc
coating results due to the tendency of the molten zinc to diffuse into the base metal. The time and
temperature of dipping controls the character and thickness of coating layer. The usual coating thickness of
galvanised sheets variesfrom0.025 to 0.3 mm. At higher temperature diffusion rate is high; and long time in
molten zinc increases the hardness and brittleness of coating layer and causes subsequent difficulty in
bending and forming of the final product.
Parkerising: It is a process of providing phosphate coating on work surface by hot-dipping. The
phosphate coating on iron and steel serves as base for enamel and paints. For parkerising, the components
must be degreased, cleaned from rust and scale and then dipped in a solution of manganese si-hydrogen
phosphate maintained at a temperature of 90°C. The components are held for about 45minutes. During this
period, the solution decomposes and phosphate separates out and forms a thick layer on the steel
MADIN P
OLY TECHNIC
C OLL
finish is necessary to apply organic coatings.
IX. a)
Open-looped system: In open loop system the input signal is given to machine slide to move to a
certain position, the slide will move to its ordered position and then stop. The actual motion and the
specified motion are not monitored since the components of an open loop system are not tied up by
feedback. The open loop system should be applied where there is no change in conditions. These machines
carry a circuit to control the functions such as to start or to stop the flow of cutting fluids, rotation of spindle
etc and feedback is not required.
Closed-looped system: In closed loop system the feedback is built into the system. The term feedback
is used to describe various methods of transmitting the positional information of machine slide from
position measuring unit to control unit. The closed loop system monitors the actual motion of slide.
Feedback signal to control and indicates whether the slide moved correctly to its new position or not, its
position is automatically corrected; and if the error is zero, no correction action takes place. So closed loop
system use an error-actuater system. The use of closed loop system enables to achieve high degree of
accuracy due to presence of feedback system. This system is applied to fully automatic machine tools.
MADIN P
OLY TECHNIC
C OLL
EGE
www.madinpoly.com
IX. b)Automated guided vehicle systems offer a viable solution when the conventional systems are in
adequate to satisfy the requirements of plants. They are employed where the product is carried out through
interconnected work cells and where flexibility and rapid change-over times are of primary importance.
AGVS possess intrinsic flexibility and capability to integrate with other automatic devices such as robots,
CNC, automatic storage system. These system find application for distribution, assembly and
manufacturing.
i) Point-to-point robots
i) Cartesian robot - three linear arms
ii) Cylindrical robot - two linear and one rotary axis
iii) Spherical robot - one linear and two rotary axes
MADIN P
OLY TECHNIC
C OLL
4. Based on manipulation function
i) Pick and place robots
ii) Special purpose robots
X.b) ADVANTAGES OF N. C MACHINES
1. NC machines are capable of uninterrupted machining and do not stop at the end of cut to plan its next
move.
2. Complex contour shapes can be machined economically.
3. Produce parts with high accuracy and close tolerances without taking any special precautions.
4. Required less operator skills
5. Expensive jigs and fixtures are not required
6. High flexibility, change in part design can be incorporated by simply changing part of tape programme.
7. Setup and tool layout time is reduced; higher machine utilization and more time is available for
machining.
8. Human errors are eliminated and therefore, inspection cost is reduced.
9. Uniformity in duplicating is assured.
10. Programmed tapes can be stored and reused whenever a repeat order is received
MADIN P
OLY TECHNIC
C OLL
EGE
www.madinpoly.com
DISADVANTAGES:
1. The initial cost of machine is higher than conventional machine tools
2. Trained engineers are required to prepare the programme
3. The machine should be fully utilized to justify the investment
MADIN P
OLY TECHNIC
C OLL

Documents

Subject: ADVANCED PRODUCTION PROCESSES &2//(*( Branch