shper slotter planner

What is a shaper ?

• A Machine which produces flat surfaces
• A Ram holding the Tool reciprocates
• Work is fed perpendicular to the tool
working principle
• Cutting Tool repeatedly travels along line A B
• Work is fed a small distance each time
• Feed of work & line of tool motion are in same plane but perpendicular
• The tool line eventually reaches position C D
• Combination of two movements results in the flat plane ABCD being machined
Classification of shapers
Basic types:
• Horizontal Shaper
• Vertical Shaper
• Traveling head Shaper
Horizontal shaper:
• Ram holding the cutting tool moves In horizontal plane
Vertical shaper:
• The cutting tool moves in vertical plane
Traveling head shaper:
• Cutting tool reciprocates & moves cross wise simultaneously.
1. Acc. to Cutting
Stroke action a) Push Type Shaper
b) Draw Type Shaper

a) Standard Shaper
2. Acc. to the
Table Design:
b) Universal Shaper
a) Crank type
3. Acc. to Driving
Mechanism: b) Geared type

c) Hydraulic Shaper
Push type shaper
• Metal is removed when the ram moves away from column
• Most common type used in practice
• Unless otherwise specified, the term shaper refers to Push type Shaper

Draw type shaper
• Metal is removed when the tool is drawn towards the column
• Allows heavier cuts to be made
• Less vibration during cutting
Standard shaper
Work Table can be moved
1.Vertically & 2. Horizontally
Universal shaper
Table can be moved
1. Horizontally 2. Vertically 3. Swivelled &
4. Tilted
This is mostly used in Tool Rooms
Crank type shaper:
• Driving mechanism is by crank & gear
Geared type shaper:
• Driven by Rack & Pinion mechanism

Hydraulic shaper:
• Driven by oil pressure developed by a pump, which is run by an electric motor.
• Construction of Shaper
Main parts of a shaping machine
1. BASE 5. CROSS RAIL
2. COLUMN 6. SADDLE
3. RAM 7. TOOL HEAD
4. TABLE 8. CLAPPER BOX
1. Base
• Bottom most part
• Supports other parts of the machine
• Acts as a reservoir of lubricating oil
• Made of Cast Iron
2. Column
• Vertically mounted on the base
• Houses Driving Mechanism of Ram
• Has guide ways on which Ram slides
• Made of Cast Iron
3. Ram

• The main moving part of a Shaper
• It carries Tool Head
• Connected to Driving Mechanism
4.Table
• A box like casting with T-slots on its top
• Shaper vice is fitted in the T-slots
• Work is fixed in the vice
5. Cross rail
• Used to move the Table Up & Down
• Upward movement is controlled by an Elevating Screw
• Side movement is controlled by lead screw
6. Saddle
• It is mounted on cross rail
• It supports the Table
• Moves across the cross rail left to right
• Movement obtained by a cross feed screw
7. Tool head
• It is attached to the front end of Ram
• Carries Clapper box & Tool post on it
• Can be swiveled at any angle on either side

8. Clapper box
• It is hinged to the tool head
• It houses clapper block
• Swings outward in return stroke
• Tool post mounted on clapper block
Specifications of Shaping Machine
• Max.length of Stroke of Ram
• Type of Drive
• Power input
• Floor Space required
• Weight of the Machine
• Cutting to Return Stroke ratio
• Feed
Shaper Drive Mechanisms
• Since return stroke does no cutting the ram should move faster during return stroke.
• The shaper drive system incorporates quick return mechanism. So that the ram moves faster during return stroke
• Thus minimizing the (idle time) Quick Return time.
Shaper Driving Mechanisms
• Whitworth quick return mechanism
• Slotted link quick return mechanism
• Hydraulic quick return mechanism
Whitworth Quick Return Mechanism

• Crank BC revolves at a uniform speed.
• During cutting stroke point C travels from Y to X through Z.
• Ram returns at high speed as the crank rotates from X to Y through T.
• Then:
Time for cutting stroke 360 - Ø
Time for return stroke Ø

• Since Ø is smaller than 360 – Ø, the time for cutting is more than the idle time.
• Stroke length can be changed by varying the radius AE
• On entering the cut the highest pressure on the tool and the slowest speed is available.
• On entering the cut the maximum pressure is holding the ram down in its slides
Crank & Slotted Link QRM


• Crank pin(11) is fitted in the slotted link(9)
• Bottom end of slotted link (rocker arm) is attached to frame of column(15)
• Its upper end is connected to ram(2).
• Electric motor drives pinion (1)
• Pinion (1) drives the bull gear(14)
• A Radial slide (16) is bolted at the centre of bull gear.
• Radial slide carries a sliding block(12) & a crank pin (11)
• As the bull gear 14 rotates, crank pin 11 rotates.
• So sliding block 12 also rotates on the crank pin circle.
• Simultaneously crankpin will move up & down in the slot of the slotted link 9.
• As the crank pin11 moves, slotted link 9 gets rocking movement.
• This rocking movement is communicated to the ram.
• Thus the rotary motion of the bull gear is converted to reciprocating motion of the ram.
• When the link is in the position PM, ram will be at the extreme backward position.
• When it is at PN, ram is at extreme forward position
• PM&PN are tangents drawn to the crank pin circle.
• Forward cutting stroke takes place through the angle C1 K C2
• Return stroke takes place through the angle C2 L C1 of the crank.
• It is evident that angle C2 K C1
is greater than C2 L C1
• Angular velocity of crank pin is constant.
• So Return stroke is completed in a shorter time.
• Therefore it is known as quick return motion.
Ratio between cutting time & return time.
• Cutting time : Return stroke = Angle C1KC2 : Angle C2LC1
• Cutting time : Return time ratio
• usually varies bet 2 : 1.
• Practical limit is 3 : 2
Hydraulic Quick Return
Motion Mechanism
• The Ram with cutting tool has to move slowly in cutting stroke
• Ram to return quickly in idle stroke
• The first 2 methods are discussed already
• The 3rd method is by Hydraulic Mechanism
• If the Quick Return Motion is obtained by hydraulic means in a Shaper
• Then such a Shaping Machine is Known as HYDRAULIC SHAPER

WORKING – Forward Stroke
• Oil is pumped to Right side of Cylinder
• Piston moves Left Hand Side
• Ram moves Forward Stroke
• Shaper dog hits the reversing lever
• Reversing lever alters valve position
• Oil is now pumped to Left side of Piston
• Piston moves Right Side
• Ram performs Return Stroke
• Oil on the Right side of Piston goes to reservoir
• At the end of Return stroke another trip dog hits reversing lever
• Reversing lever changes direction of stroke of Piston
• Thus the Cycle is repeated

QRM is obtained
• Due to the difference in stroke volume
• Volume on Left side of piston is small due to presence of piston rod
• Right side volume is larger ( absence of piston rod)
• Pump pumps same amount of oil both sides
• As volume is small on Left side, pressure increases
• Increase in pressure causes Speed of ram to increase in Return stroke
Advantages of Hydraulic Shaper
• Cutting tool works uniformly during cutting stroke
• Reverse stroke is obtained without any shock
• More no. of cutting speeds are obtained
• Good control on cutting speed
• Relief valve ensures safety i.e. Machine is not overloaded
Shaper Operations
• Machining Horizontal Surfaces
• Machining Vertical Surfaces
• Machining Angular Surfaces
• Cutting Slots, Grooves & Key ways
• Machining irregular surfaces
• Machining Splines / Cutting Gears
Steps for Machining
• Work is properly held in a vice
• Table is raised to a gap of 25 to 30 mm between tool & work
• The length & position of stroke are adjusted
• The length of stroke should be nearly 20 mm longer than the work
• The approach & over run should be 10 & 5 mm respectively.
• Depth of cut is adjusted by rotating down the feed screw of tool head
• Feed is adjusted about half the width of cutting edge of tool

Machining Horizontal Surfaces
• Fix the work properly on the table
• Adjust the length of stroke
• Set the required cutting speed
• Give required feed of the table
• Fix an appropriate tool in the tool head
• Give suitable depth of cut for rough cuts
• Finishing the job by giving less depth of cut
Machining Vertical Surfaces
• Fix up the job on the table firmly
• Align the surface to be machined properly
• Fix up a side cutting tool in the tool head
• Set the vertical slide exactly at zero
• Swivel the apron away from the job
• Switch on the machine
• Rotate down feed screw by hand to give down feed
• Feed in about 0.25 mm
Machining Angular Surfaces
• Angular shaping is carried out to machine inclined surfaces, bevelled, dove tail etc.,
• Set the work on the table
• Swivel the vertical slide of tool head to the required angle ( to the left or right)
• Set apron away from work
• Give down feed as per requirement
Cutting Rack or Splines
• Fix up a square nose tool in tool head
• Adjust the length & position of stroke
• Reduce the cutting speed
• Give suitable depth of cut
• Feed the work properly to get equal splines
Cutting Key ways
• Fix up the job between two centres
• Cut first spline similar to a key way
• Move / Rotate work by the required amount
• Use index plate for this purpose

Machining irregular surfaces
• Fix up a forming tool in tool post
• Give cross feed in conjunction with down feed
• Swivel the apron suitably according to the contour required
Clamping the Work on a Shaper
Work should be properly & firmly fixed on the Shaper table
Work is fixed on the table by 3 methods.
• Using a Swivel Vice
• Using T bolts & Clamps
• Using Angle plate & C Clamps
Slotting machine
• A Machine which produces flat surfaces
• A Ram holding the Tool reciprocates
• Ram reciprocates in verticle direction
• Work is fed perpendicular to the tool
Slotter - working principle
• Cutting Tool repeatedly travels along line A B
• Work is fed a small distance each time
• Feed of work & line of tool motion are in same plane but perpendicular
• The tool line eventually reaches position C D

• Combination of two movements results in the flat plane ABCD being machined
• Work is supported on a rotary table.

• Table can have longitudinal and rotary movements

• Straight and rotary cuts can be produced.
CLASSIFICATION
According to design and purpose the slotters
are classified into two types
Puncher Slotter
Precision tool room Slotter
Puncher slotter:
• Intended for removing large amount of metal from heavy works.
• heavy and rigid machine
• Ram driven by rack and spiral pinion mechanism
• used for machining large castings and forgings
Precision tool room slotter:
• Used for tool room work, where accuracy important
• Lighter in construction
• Fitted with quick return mechanism
• Operates at high speeds and designed for light cuts
• Gives accurate finish
• Suitable for small to medium size work pieces
Difference between vertical shaper and Slotter
• in verticle shaper the tool holding ram can tilt by about 50
with respect to verticle axis
• In slotter ram cannot tilt at all.
• In all other aspects verticle shaper and slotter are similar
Main parts of a slotter
1. Base 5. Cross slide
2. Column 6. Saddle
3. Ram 7. Tool head
4. Table
1. Base
• Bottom most part
• Supports other parts of the machine
• Acts as a reservoir of lubricating oil
• Made of Cast Iron
Base
• Rigidly built to take up cutting forces
• Top of bed is accurately finished
• Guide ways are provided for saddle
• Guide ways are perpendicular to column face
Column
• Vertically mounted on the base
• Houses Driving Mechanism of Ram
• Has guide ways on which Ram slides
• Made of Cast Iron
• Also houses feeding mechanism
Ram
• Reciprocating vertically up and down of a slotter
• Mounted on guide ways of column
• It carries Tool Head / cutting tool
• Connected to Driving Mechanism
• An arrangement is provided on the body of ram to change length of stroke
Table
• It holds the work piece.
• A circular casting with T-slots on its top
• Movement of table can be linear or rotary
• Table is graduated in degrees so indexing can be done
• Slotter vice may be fitted in the T-slots
• Work may be fixed in the vice
• Operated manually or by power
Saddle
• It is mounted on guide ways of bed
• It can be moved towards or away from bed
• Using saddle longitudinal feed is given
• Top is accurately finished to provide guide ways for cross slide
• These guide ways are perpendicular to the guide on the base
• Operated either manually or by power
Cross slide
• Circular work-table is mounted on the top.
• Mounted on guide ways of saddle
• Moves parallel to the face of the column
• Using cross slide cross feed is given
• Operated either manually or by power
Tool head
• It is attached to the bottom end of Ram
• Carries Tool post on it
• Tool is fixed in position
• No swiveling along verticle axis or horizontal axis
Specifications of Slotting machine
• Max. length of Ram Stroke
• Diameter of work table in mm.
• Type of Drive
• Maximum table travel.
• Power input
• Floor Space required
Specifications Contd..
• Amount of longitudinal travel in mm
• No. of speeds available
• No. of feeds available
• Table feed.
Slotter driving mechanism
• A Slotting machine produces flat surfaces
• The Ram holding the Tool reciprocates vertically up and down
• Cuts the material only in down stroke
• There should be some mechanism to move the ram in reciprocating motion
• It is called as slotter driving mechanism
• The mechanism commonly used is slotted disc mechanism
Quick return mechanism (QRM)
• A Mechanism makes the ram to move slowly during cutting stroke.
• During return stroke ram moves at a faster rate.
• To reduce the idle time,It Should return quickly .
• The mechanism adopted is known as QRM
Methods to obtain Q.R.M. in slotter
. Whitworth Q.R.M. Mechanism
2. Variable speed reversible motor drive mechanism
3. Hydraulic drive Mechanism
The mechanisms for QRM in slotter are similar to QRM in shaper
Feed in Slotter
• In Slotter feed is given by table
• Feed movement is intermittent
• Feed is given at the beginning of the cutting stroke
• Feed may be given either manually or by power
• Table will have three types of feed movements
a. longitudinal
b. cross and
c. circular feeds.
Types of feed in Slotter
Longitudinal feed:
• Table is fed perpendicular to the column
• Table moves towards or away from the column
Cross feed:
• Table is fed parallel to the face of the column
Circular feed:
• table is rotated with respect to verticle axis
Feed mechanism of a Slotter
• Uses a ratchet and pawl mechanism
• Feed shaft engaged with cross, longitudinal / rotary feed screws has the ratchet mounted on it.
• Ratchet is moved by small amount in one direction only with the help of a connecting rod, lever.
• The roller moves in the cam groove cut on the face of the bull gear of slotting machine.
Operations on slotter
1. Machining flat surfaces
2. Machining Circular Surfaces
3. Machining internal surfaces
4. Machining grooves or key ways
Setup for Machining
• Work is properly held in a vice
• Table is raised to a gap of 25 to 30 mm between tool & work
• The length & position of stroke are adjusted
• The length of stroke should be nearly 20 mm longer than the work
• The approach & over run should be 10 & 5 mm respectively.
• Depth of cut is adjusted by rotating down the feed screw of tool head
• Feed is adjusted about half the width of cutting edge of tool
Machining Flat Surfaces
• Fix the work properly on the table
• Adjust the length of stroke
• Set the required cutting speed
• Give required feed of the table
• Tool is held in the tool head of ram
• Ram reciprocates up and down
• Feed has to be given at the beginning of cutting stroke
• Both internal and external surfaces can be machined
• Give suitable depth of cut for rough cuts
• Finishing the job by giving less depth of cut
Machining circular surfaces
• Tool is set radially on the work
• Work piece is placed centrally on the rotary table
• Feed is given by the rotary table feed screw
• Feed screw rotates the table through an arc
• Adjust the length of stroke
• Set the required cutting speed
• Finishing the job by giving less depth of cut
Machining internal surfaces
• Fix up a tool in tool post
• Cross, longitudinal and rotary feed are combined
• Any contoured surface can be machined
• Mostly done manually
• Good skill is required from operator
Machining grooves or key ways
• Slotter is specially intended for cutting internal grooves
• External or internal gar teeth can be machined
• Fix up the job between two centers
• Cut first a key way
• Move / Rotate work by the required amount
• Indexing can be done by using graduations on rotary table
Cutting Key ways
• Fix up the job between two centres
• Cut first spline similar to a key way
• Move / Rotate work by the required amount
• Use index plate for this purpose
Work holding devices
Work should be properly & firmly fixed on the Slotter table
Work is fixed on the table by 3 methods.
1. Using a Swivel Vice
2. Using T bolts & Clamps
3. Using Angle plate & C Clamps
What is a planer ?
• A Machine which produces flat surfaces
• Consists a stationary housing for holding the tools
• A table holding the work reciprocates
• Large works, that con not be accommodate on shapers
• The tool is stationary but the work moves
Planer - working principle
• The table on which work is clamped is imparted a reciprocating movement
• Cutting takes place during the forward stroke of table
• During return stroke the cutting tool is slightly lifted
• Tool is fed for each forward stroke
• Table is driven by an electric motor
• Length of table stroke can be adjusted
• Speed of return stroke is also regulated
Classification of planers
Double housing Planer
2. Open side Planer
3. Pit type Planer
4. Edge Planer or Plate Planer
5. Divided Table Planer
Double housing planer:
• It is the Standard model & most widely used
• Very heavy and robust
• Has a bed and two vertical housings are fixed
• Table moves along the guide ways of the bed
• Housing supports cross rail & tool heads.
• Cross rail carries two tool heads
• Tool head carries tools
Open side planer
• It has only one supporting column (housing)
• Area larger than the table can be planed
• Cross rail is mounted as a Cantilever
• Tool holders ( max.3) are mounted on Cross rail
• Stroke length of bed is controled by adjustable dogs
PIT Planer
• Columns and cross rail carrying tool head move longitudinally on massive rail above the work table
• Bed is recessed in the floor
• Loading and unloading of jobs is easy
• Used for Planing heavy & large jobs
• Table and work piece resting on it are stationary and the tool reciprocates
Edge / plate planer
• Specially designed for squaring or beveling the edges of heavy steel plates for pressure vessels
• Carriage supporting the tool is moved back and front direction
• Cutting can take place during both directions of carriage travel
• Operator stands on the platform & operates
Divided table planer
• Also known as Tandem planer
• Planer has two tables on the bed
• Table may be reciprocated together or separately
• Each table reciprocates under different tool head
• For continuous production, small work pieces clamped on one table are being machined, another is stationary and can be used for setting up fresh works
• Used for quick & continuous production
Main Parts of Planing machine
1. Bed
2. Table
3. Housing or Column
4. Cross rail
5. Tool heads
6. Driving Mechanism
7. Feed Mechanism
1. Bed
• Large box like casting
• Length is nearly twice the table length
• Consists guide ways on which table moves
• Houses the driving mechanism of table
• Made of Cast Iron
2.Table
• Also called Platen
• Large rectangular casting mounted on bed ways
• Holds the work & reciprocates along bed ways
• Top surface has T slots
• Work is clamped on T slots
3.Housing or Column
• Large vertical structures on each side of the bed
• Supports cross rail on which tool heads are mounted
• Also supports the mechanism for operating the tool heads
• Made of Cast Iron
4. Cross rail
• A rigid casting mounted horizontally on the column
• Can be moved up & down by elevating screw
• Carries two slides with tool heads
• Tool heads can be moved horizontally on the guide ways of cross rail
5. Tool heads
• Contains tool posts for holding the tools
• Tool post (clapper block) is hinged to the head
• During return stroke cutting tool will be lifted
• Tool heads can be swiveled through 60º on either side of its vertical position
Specifications of a Planer
. Distance between the two housings
2. Height between Table & cross rail at its uppermost
position
3. Maximum length of table travel
4. Number of Speeds & feeds available
5. Power input
6. Floor space required
7. Type of Drive
8. Net weight of the Machine
Mechanisms used to drive the table
• A Planing Machine produces flat surfaces
• The Table holding the Work reciprocates
• There should be some mechanism to move the Table in reciprocating motion, and
• Table to move quick during idle stroke
Mechanisms to drive the Table (QRM)
. Open & Cross belt drive
2. Reversible motor drive
3. Hydraulic drive
Open & Cross belt drive Mechanism
• Used for smaller capacity machines
• Table is moved by gears & rack attached under
the table
• Counter shaft at the top of housing has 2 pulleys
• Pulleys transfer power to main shaft
• Main shaft drives the table by rack & pinion
• 2 Sets of fast & loose pulleys are mounted on driving shaft
• Smaller fast pulley is used for backward motion of table (Quick motion)
• It is connected by open belt drive
• Bigger fast pulley is driven by cross belt drive
• It is used to drive the table during forward stroke
• At the end of cutting stroke, cross belt is shifted from fast pulley to loose pulley
• Simultaneously open belt is shifted from loose pulley to fast pulley
• This is achieved by trip dog which operates belt shifting lever
• Thus the direction of movement is automatically reversed
2. Reversible Motor Drive Mechanism
• Electric motor drives the bull gear through gear trains
• Motor is coupled to D.C. generator
• When motor is started, generator supplies power to reversible motor
• Reversible motor causes the planer table to move
• At the end of stroke, trip dog operates the switch which reverses the direction of table
• Speed of cutting stroke is reduced by regulating the field current of the generator
3.Hydraulic Drive of Planer
Forward Stroke of Table
• During cutting stroke, oil is pumped into LHS of cylinder
• As the area is less due to presence of piston rod, less force acts
• So the table moves slowly in cutting stroke
• At the end of each stroke trip dog operates a lever
• Lever actuates the control valve of circuit
Return Stroke of Table
• Oil is pumped into the Operating cylinder
• Cylinder contains piston & piston rod
• The other end of piston rod is connected to the Table
• During return stroke, oil is pumped into RHS of cylinder
• More force acts on the piston & it moves quickly
Planer Operations
1.Planing Horizontal Surfaces
2. Planing Vertical Surfaces
3. Planing Angular Surfaces / Dovetails
4. Planing Curved surfaces
5. Planing Slots & Grooves
Planing Horizontal Surfaces
• Fix the work properly on the table
• Set the required cutting speed
• Give required feed of the tool
• Give suitable depth of cut for rough cuts
• Finishing the job by giving less depth of cut
Planing Vertical Surfaces
• Fix the job on the table firmly
• Align the surface to be machined properly
• Vertical slide is adjusted perpendicular to the table
• Swivel the apron away from the job
• Switch on the machine
• Rotate down feed screw by hand to give down feed
Planing Angular Surfaces
• Main angular planing is to make dove tails & V grooves
• Set the work on the table
• Swivel the tool head to the required angle
• Set apron away from work
• Give down feed as per requirement
Planing Formed Surfaces
• Fix up a square nose tool in tool head
• Required form is obtained by feeding the tool simultaneously in both hor. & ver. Directions
• Give suitable depth of cut
• This can also be done with the aid of a special fixture
Planing Slots & Grooves
• Fix up the job on the table suitably
• Fix Slotter tools in tool heads
• Give feed using down feed screw
• Move the tool by the required amount to get uniform slots / grooves
broach
BROACHING OPERATION
• A method of metal removal with a special tool called Broach.
• Cutting tool called broach has three types of teeth, namely roughly teeth, semi finishing teeth, finishing teeth
• Broach can be pulled or pushed in a fixed path
• Surfaces machined may be flat or contoured can be produced in a single pass or stroke of broach
• Both internal and external surfaces can be machined
• But limited to removal of 6 mm stock or less
BROACHING OPERATION
• Surfaces machined may be flat or contoured can be produced in a work piece by a single pass or stroke of broach.
• Both internal and external surfaces can be machined
• But limited to removal of 6mm stock or less
BROACH
• Tool used in broaching
• Broach is a multi-teeth cutter produced to close tolerances.
• It has successively higher cutting edges along length
• It has three types of teeth, is rough, semi finish, finish teeth.
• Available in different shapes and sizes
• For irregular shapes one broach for one contour or shape has to be developed
• High speed steel is the most widely used material for producing broach.
• Carbide tools are also used for machining steel castings
CLASSIFICATION OF BROACHES
Broaches may be classified on different criteria, some of them are
According to type of operation
i) internal broach
ii) external broach
According to method of operation
i) push broach
ii) pull broach
According to type of construction
i) solid broach
ii) built-up broach
iii) inserted tooth broach
iv) progressive cut broach
According to function
i) surface broach
ii) key way broach
iii) round hole broach
iv) Spiral broach
PUSH BROACH
• Designed to be pushed through a stationary work piece
• It has tendency to bend under compressive load
• It is short and stocky
• Fewer teeth on broach
• Less stock can be removed for each pass
• So production time will be more
PULL BROACH
• Designed to pull through a stationary work piece
• Tool is in tension during cutting
• Pull broach is long and slender
• It has large number of teeth
• More stock can be removed
• Production time will be less
BROACHING METHODS
According to method of operation the broaching may be classified as
• pull broaching
• push broaching
• surface broaching
• continuous broaching
PULL BROACHING
• Work is held stationary
• Broach is held in a special head
• Broach is pulled over or through the work
• Mostly used for internal broaching
• Surface broaching can also be done
PUSH BROACHING
• Work is held stationary
• Broach is held in a special head
• Broach is pushed over or through the work
• Mostly used for
i) sizing already drilled holes
ii) cutting key ways
• Broach is operated by
i) manually
or ii) Hydraulic arbor press
• less metal is removed
SURFACE BROACHING
• Work is held in a fixture and tool in tool head
• Either work or broach moves across each other
• Tools must be specially designed for each work piece
• Many irregular and intricate shapes can be broached
• Produces excellent surface finish
• Time required will be very low when compared to other machining processes.
CONTINUOUS BROACHING
• Broach tool is held stationary
• Work pieces are moved continuously
• Path of work piece movement may be
i. Straight horizontal
or ii. Circular
• Suitable for producing similar work pieces
• Suitable for mass production
• Suitable for small size work pieces only
BROACHING MACHINES
• Simplest of all machine tools
• Have less components
• Broaching machines consist of :
work holding fixture
broaching tool
drive mechanism
suitable supporting frame
• Most machines are hydraulically operated
• Has smooth and uniform cutting action
• Used for low or high production quantities.
CLASSIFICATION OF BROACHING MACHINES
Broaching machines are mainly classified as
• Horizontal broaching machines (push or pull type)
• Vertical broaching machines
• Special design continuous broaching machine
• Rotary table continuous broaching machine
• horizontal continuous broaching machine
HORIZONTAL BROACHING MACHINE
Main parts of the broaching machine are
Bed
Housing
Drive mechanism
Broach pilot
Fixture
BED:
• Bottom most part
• Supports other parts of the machine
• Made of Cast Iron
HOUSING: houses the driving mechanism
houes the pulling head
DRIVE MECHANISM
drives the pulling head
cutting stroke speed is less
return stroke speed is more
• Broach pilot holds the broach rigidly
• Fixture holds the work piece rigidly
HORIZONTAL BROACHING MACHINE
• Both surface and internal broaching can be done
• Broach is securely held in a pulling head
• In surface broaching broach is pulled over the surface
• For internal broaching broach is pulled through work
• Mainly used for internal broaching
• Operated at cutting speed of 3 to 5 m/min
• Speed of return stroke is 30 m/min
• Hydraulic drive is used for pulling head
• Operated at infinitely variable range of cutting speeds
• Hydraulic cylinder is housed on right side of the machine
• Long broaches are easily handled
• heavy work pieces are easily handled
• occupies more space than vertical machine
Uses
It is used to machine
• Keyways
• Splines
• Slots
• Round holes
• Other internal shapes
These are further classified as
• Surface broaching machines
• internal broaching machines
VERTICAL BROACHING MACHINE
• it may either push type or pull type
• pull type is popular
• Main parts of vertical broaching machines are
Base
Column
Ram and broach
Fixture and table
Drive mechanism
• Three models are available in vertical type
pull up
pull down
push down
• Pull up model is most popular
• Broach is securely held in ram
• Occupy less floor space
• Modern vertical machines are available with
• Hydraulic drive
• Electro-mechanical drive
• Hydraulic drive machines cost less
• Require plat form or pit for the operator
• Convenient to pass work from one machine to other
• Employed in multiple operations

• Two rams will be provided on some machines
• Such machines are called duplex head machines
DUPLEX HEAD BROACHING MACHINE
• Machine with two heads
• Simultaneously two surfaces can be machined
• Mostly push type machines
• Commonly employed for surface broaching
• Rate of production is high
CONTINUOUS BROACHING MACHINES
• used for mass production of small parts
• they are of two types
– Rotary continuous broaching machine
– Horizontal continuous broaching machine
• In both machines
– Broach is stationary
– Work pieces move across broach
ROTARY CONTINUOUS BROACHING MACHINES
• Work pieces are loaded on the table
• Table rotates continuously
• During broaching broach is stationary
• Work pieces are held in fixtures
• Work pieces come into contact with broach during table rotation
• Loading and unloading done on the table
• It is a surface machining operation
• Heavy production rate
హొరిజొంతల్ ఓణ్టీణూఓఊ బ్రోఅచింగ్ మచినెస్
• వర్క్ పిఎసుస్ అరె కార్రిఎద్ బి ఎంద లెస్ చిన్
• Chain carries work holding fixtures
• Work pieces are placed in fixtures
• Broach is held stationary
• When chain rotates the work pieces move against stationary broach
• It is a surface broaching operation
• Heavy production rate
SPECIFICATION OF BROACHING MACHINE
• Main specification
– Length of stroke in mm.
– Force that can be applied to broach in tones
i.e., broaching machine with specification 1000-10 means
• Machine has 1000 mm stroke length and
• 10 tones broach driving force
Other parameters to be specified are
• Broaching speed
• Return speed
• Machine horse power
• Floor space required
• H.P of the motor
BROACHING OPERATIONS
Broaching is applied for
• various internal and external surfaces
• round and irregular shaped holes of 6 to 100 mm
diameter
• Flat and contoured surfaces
Most operations are completed with one pass of the broach
In all broaching operations
• Work is held in a fixture
• Tool is held in tool head (pulling or pushing head)
• Either work or tool move across each other
• Various broaching operations are as shown in following slides
Nomenclature of broach tooth
Pitch:
linear distance between cutting edge of one tooth and corresponding edge on next tooth
Land:
top portion of tool
ground to provide a slight clearance
Back off:
it is the clearance angle of broach
its value vary from 0.50 to 200
Rake angle:
it corresponds to rake angle of lathe tool
its value increases as ductility increases
ADVANTAGES OF BROACHING
• rate of production is high
• Less skilled worker can be employed
• High accuracy can be obtained
• High surface finish can be obtained
• Rough and finish cut both are completed in one pass
• both internal and external surfaces can be machined
• Any form that can be reproduced on broach can be machined
• Cutting fluid may be readily applied
• Life of broach tool is high
• Cutting temperature and tool wear is low
• Cutting force acts in clamping direction
• Process can be semi or fully automised
LIMITATIONS OF BROACHING
• High tool cost
• Economical only for mass production
• Sharpening is difficult and expensive
• Not suitable for very large work pieces
• Surfaces should not have obstructions
• Cannot remove large amount of stock
• Very light and delicate jobs cannot be broached