Shaper slotter planer

UNIT-3SHAPING , SLOTTING & PLANING MACHINES

By

D. Kanaka RajaDepartment of mechanical engineering,

AITS

2

Shaping Machine is also called Shaper

3

What is a shaper ? A Machine which

produces flat surfaces

A Ram holding the Tool reciprocates

Work is fed perpendicular to the tool

4

Shaper - working principle

WORK

TOOL

B

A

In the shaper, the cutting tool has a reciprocating motion, and it cuts only during the forward stroke.

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

5

Working principle – Contd.

The tool line eventually reaches position C D

Combination of two movements results in the flat plane ABCD being machined B

A

D

C

6

Classification of shapers

Basic types:

Horizontal Shaper

Vertical Shaper

Traveling head Shaper

7

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.

8

Detailed classification

M305.23 9

a) Push Type Shaper 1. Acc. to Cutting Stroke action 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

10

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

11

Draw type shaper

Metal is removed when the tool is drawn towards the column

Allows heavier cuts to be made

Less vibration during cutting

12

Standard shaper Work Table can be moved Vertically & Horizontally. it cannot swivelled or tilted.

Universal shaper Table can be moved Horizontally Vertically Swivelled & Tilted This is mostly used in Tool Rooms

13

Crank type shaper: Driving mechanism is by crank and a slotted lever quick return

motion mechanism is used to give reciprocating motion to the ram. The crank is adjustable and is arranged inside the body of bull 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.• It is more efficient than the crank and geared type shapers.

14

SHAPING MACHINE - Working

15

SHAPING MACHINE - PARTS

BASE

COLUMN

RAM

CROSS RAIL

TABLE

TOOL

16

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

17

Constructional details of a shaper

BASE

TABLE

CROSS RAIL

RAMTOOL HEAD RAM CLAMP

CLUTCH

COLUMN

TOOL POST

BASE

18

Parts - functions

1. Base Bottom most part Supports other parts of the machine Acts as a reservoir of lubricating oil Made of Cast Iron

BASE

19

2. Column

Vertically mounted on the base

Houses Driving Mechanism of Ram

Has guide ways on which Ram slides

Made of Cast Iron

COLUMN

20

3. Ram

The main moving

part of a Shaper It carries Tool Head Connected to Driving

Mechanism

R A M

21

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

TABLE

22

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

CROSSRAIL

23

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 SADDLE

CROSS RAIL

24

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

TOOL HEAD

TOOL POST

CLAPPER BOX

25

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

CLAPPER BOX

26

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 • Size of table• Maximum horizontal and vertical travel of the table

27

Working of shaper

Shaper drive Mechanism changes rotary motion of power source (Electric motor) to reciprocating motion of Ram.

Material removal (cutting) of work piece takes place in the forward stroke of ram.

The return stroke of the ram does no cutting, hence is called Idle stroke.

The Ram with cutting tool has to move slowly in cutting stroke.

28

•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.

Working of shaper

29

Shaper Operations

Machining Horizontal Surfaces

Machining Vertical Surfaces

Machining Angular Surfaces

Cutting Slots, Grooves & Key ways

Machining irregular surfaces

Machining Splines / Cutting Gears

30

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

31

Steps for Machining 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

32


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

33


34


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

35


36


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

37


38

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

39


40

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

41

Cutting Key ways (At the end)

42

Cutting Key ways (Midway)

43


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

44


WORK

TOOL

Advantages and limitations of shaper Advantages The set up is very quick and

easy and can be readily changed from one job to another.

The work can held easily. The single point tools used are

in inexpensive; These tools can be easily

grounded to any desired shape. Lower first cost. The cutting stroke has a definite

stopping point. Because lower cutting forces,

thin and fragile jobs can be conventionally machined on shapers.

Limitations By nature is a slow machine

because of its straight line, forward and return stroke. The single point tool requires several strokes to complete a work.

The cutting speeds are not usually very high speeds of reciprocating motion due to high inertia forces developed in the motion of the units and components of the machine. Owing to these reasons the shaper does not find ready adaptability for assembly and production line.

46

Shaper Driving Mechanisms

• Whitworth quick return mechanism• Slotted link quick return mechanism• Hydraulic quick return mechanism

47

Quick Return Mechanism

Q.R.M

48

Whitworth Quick Return Mechanism

49


50


51


52

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

=


53

Crank & Slotted Link

54

Crank & Slotted Link QRM

55

Main Parts of the Mechanism

BULLGEAR

BULLGEAR

SLIDING BLOCK

CRANK PIN

BULLGEAR

SLIDE

LEAD SCREWBEVEL GEARS

ROCKER ARM

SLIDING BLOCK

56

Line diagram ofCrank & Slotted lever Mechanism

Driving Pinion

Slotted Lever

Crank pin

Lead Screw

Clamping lever

Ram

Ram Block

Bevel Gears

Bull gear Sliding block

Lever Sliding block

Bull Gear

Bull gear Slide

Pivot

Bevel Gears

57

Elements of the Mechanism

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).

58

Working Principle

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.

59

Working Principle - concluded

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.

60

PRINCIPLE OF Q.R.M.

P

M N

K

O

L

C2C1

61

Principle - Explained

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.

P

M N

K

O

L

C2C1

62

Principle - Continued

PM&PN are tangents drawn to the crank pin circle.

Forward cutting stroke takes place through the angle C1K C2

Return stroke takes place through the angle C2 L C1 of the crank.

It is evident that angle C2K C1

is greater than C2 L C1 P

M N

K

O

L

C2

C1

63

Principle - Concluded

P

M N

K

O

L

C2C1

• Angular velocity of crank pin is constant.• So Return stroke is completed in a shorter time.• Therefore it is known as quick return motion.

64

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

M N

K

O

L

C2C1

Hydraulic drive

Quick return in the hydraulic shaper is accomplished by increasing the flow of hydraulic oil during the return stroke.

In the hydraulic shaper the ram is connected to the hydraulic cylinder which is controlled by means of a 4 way valve.

The hydraulic fluid is pumped to the hydraulic cylinder through 4 way valve; this valve is connected to the sump.

The 4 way valve controls the direction of high pressure fluid into the cylinder and controls the direction of motion, either the cutting stroke or return stroke.

Hydraulic drive

The flow control valve controls the flow rate of the hydraulic fluid thereby controlling the speed at which ram moves.

Since the power available remains constant throughout, it is possible to utilize the full capacity of the cutting tool during the cutting stroke

The starting and stopping of the machine is achieved by through a finger operator lever.

An adjustable trip dog operated lever controls the operation of 4 way valve to control the ram reversible.

The return or idle stroke is faster than the cutting stroke because of the smaller area in the return side of the cylinder if constant volume pump is used.

Hydraulic drive

The cutting stroke has a more constant velocity and less vibration is induced in the hydraulic shaper.

The cutting speed is generally shown on an indicator and does not require calculation.

Both the cutting stroke length and its position relative to the work may be changed quickly without stopping the machine.

The hydraulic feed operates while the tool is clear of work. More strokes per minute can be achieved by consuming less

time for reversal and return strokes.

Advantages of hydraulic drive

The stopping point of the cutting stroke in a hydraulic shaper can vary depending upon the resistance offered to cutting by the work material.

It is more expensive compared to the mechanical shaper.

Disadvantages

70

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

Work holders

72

Using a Swivel Vice

73

Using T bolts & Clamps

Cutting speed is defined as the average linear speed in stroke in m/mm, which depends on the number of ram stokes(or ram cycles) per minute and the length of stroke.

The number of double strokes or cycles of the ram/min N= the number of double strokes or cycles of the ram L=length of the ram stroke, mm K= return stroke time Where k=2/3, 3/4

Cutting speed

Vc = NL(1+k)/1000 m/mm

The feed is the relative motion of the work piece in a direction perpendicular to the axis of reciprocating of the ram.

Feed is given to the work piece. Depth of cut d is the thickness of the material removed in

one cut,in mm.

Feed

The machining timethe time required to complete one double stroke, from cutting speed Vc is given by

With a feed of f mm/double stroke, number of strokes required to machine a surface of width B will be Ns=B/f

Machining time

t = L(1+K)/1000Vc

Hence total machining the surface of width B will be

In terms of ram strokes N, the time for machining the surface is given by

Ns=B/fN minMachine time tm = B/f ((L/Vc*1000)+(L /Vr *1000)Where B= width of the job mm f = feed mm/ stroke l = length of stroke, mm Vc = Cutting speed Vr = return stroke speed mm/min

t = LB(1+K)/1000Vcf

Machining time

Slotting machine

89

Slotting machine

Slotting machine is also called as Slotter

90

Line diagram of slotter

SADDLE

CROSSSLIDE

91

Slotters

92

Slotter

• A Machine which produces flat surfaces

• A Ram holding the Tool reciprocates

• Ram reciprocates in vertical direction

• Work is fed perpendicular to the tool

93

Slotter - working principle

WORK

TOO

L

B

A 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

94

WORKING PRINCIPLE – contd.

The tool line eventually reaches position C D

Combination of two movements results in the flat plane ABCD being machined

BA

DC

95


Work is supported on a rotary table.

Table can have longitudinal and rotary movements

Straight and rotary cuts can be produced.

96

CLASSIFICATION

According to design and purpose the slottersare classified into two types

1. Puncher Slotter2. 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

Production slotter

98

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

99

Difference between vertical shaper and Slotter

• in vertical shaper the tool holding ram can tilt by about 100 with respect to vertical axis• In slotter ram cannot tilt at all.• In all other aspects vertical shaper and slotter are similar

M305.30 100

Slotting machine Introduction

Having known the Working Principle we will now look at :

The Constructional Details of a slotting Machine Function of each part Specifications of a slotter

M305.30 101

Slotting machine -construction

BASE

CIRCULAR TABLE

COLUMN

RAM

CROSS SLIDE

SADDLE

T-SLOTS

TOOL HEAD

M305.30 102

Slotting machine

103

Line diagram of slotter

104

Main parts of a slotter

1. Base 5. Cross slide

2. Column 6. Saddle

3. Ram 7. Tool head

4. Table

105

Parts - functions 1. Base

Bottom most part Supports other parts of the machine Acts as a reservoir of lubricating oil Made of Cast Iron

Contd..

106

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

107

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

COLUMN

M305.30 108

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

R A M

109

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

TABLE

110

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

111

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

112

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

113

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

Specification

115

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

116

Slotted disc mechanism

117

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

118

Methods to obtain Q.R.M. in slotter

1. Whitworth Q.R.M. Mechanism2. Variable speed reversible motor drive

mechanism3. Hydraulic drive Mechanism The mechanisms for QRM in slotter are similar to

QRM in shaper

119

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. longitudinalb. cross and c. circular feeds.

Contd…

120

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

121

Feed mechanism of a Slotter

Feed shaft

122

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.

Feed mechanism of a Slotter

123

Operations on slotter

1. Machining flat surfaces

2. Machining Circular Surfaces

3. Machining internal surfaces

4. Machining grooves or key ways

124

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 workContd…

125

Setup for Machining

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

126

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

127

Machining Flat Surfaces

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

128

Machining flat surfaces

129

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

130

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

131

Machining grooves or key ways

Slotter is specially intended for cutting internal grooves

External or internal gear 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

132

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

133

Cutting Key ways

134

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

135

Clamping the work on a Slotter is depicted in the following Slides, one by one

136

1. Using a Swivel Vice

137

2. Using T bolts & Clamps

Planing machine

139

Planing machine

140

Another view of Planer

141

Table Movement in Planer

142

Table Movement in Planer- another view

143

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

144

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

WORK

TOOL

Work is fixed on Table

145


Table is driven by an electric motor

Length of table stroke can be adjusted

Speed of return stroke is also regulated

146

Principle of operation of a planer

147

Classification of planers

1. Double housing Planer 2. Open side Planer 3. Pit type Planer 4. Edge Planer or Plate Planer 5. Divided Table Planer

148

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

Double housing planer:

149

A double housing planer

150

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 are mounted on Cross rail Stroke length of bed is controlled by adjustable dogs

Open side planer

152

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

153

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

154

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

155

Planing machine - parts

BED

TABLE

CROSS RAILCOLUMN

TOOL HEADS

Feed Mechanism

156

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

157

Constructional details of a planer

TOOL HEADS

CROSS RAIL

TABLE

COLUMN

BED

CROSS MEMBER

COLUMN

Feed Mechanism

158

Parts of planer

159

Parts of planer

160

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

161

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

162

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

163

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

164

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

165

Specifications of a Planer

1. 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

166

Specifications of a Planer- contd.

5. Power input

6. Floor space required

7. Type of Drive

8. Net weight of the Machine

167

Mechanism Introduction 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

168

Mechanisms to drive the Table (QRM)

1. Open & Cross belt drive

2. Reversible motor drive

3. Hydraulic drive

169

1.Open & Cross belt drive MechanismLoose Pulley

Fast Pulley

17. Belt shifter lever

Pulleys on Shaft

Open beltCross beltBelt shifter

Counter Shaft

Loose PulleysFast Pulleys

9,12

10,11

13 - Bull gear shaft14 - Bull gear

Rack

18. Trip dog19 - Table

Change gears

Feed disc

170

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

These Pulleys transfer power to main shaft(Driving)

Main shaft drives the table by rack & pinion

171

Open & Cross belt drive Mechanism 2 Sets of fast & loose pulleys are mounted on driving

shaft at one end and pinion is on another endRETURN STROKE: Smaller fast pulley is used for backward motion of table

(Quick motion) It is connected by open belt drive The open belt passes over small fast pulley to get

Quick return The Cross belt is on loose pulley so it will not drive

172

Open & Cross belt drive Mechanism FORWARD STROKE: Bigger fast pulley is driven by cross belt drive It is used to drive the table during cutting stroke Open belt is on loose pulley 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

173

Rack & Pinion used to move Table

174

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

175

Reversible Motor Drive Mechanism 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

176

Reversible Motor Drive Diagram

Exciter

A.C.driving motor Generator

Reversible motor Motor field

resistance

Motor field

Generator field

Reversing switch

177

3.Hydraulic Drive of Planer

TABLE

Operating Cylinder

Speed Control

178

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

TABLE

179

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

TABLE

180

Cycle Repeated

Flow of oil is changed from one side to the other side of cylinder

The length of stroke can be varied by adjusting the distance between trip dogs

181

Planer Operations

1.Planing Horizontal Surfaces

2. Planing Vertical Surfaces

3. Planing Angular Surfaces / Dovetails

4. Planing Curved surfaces

5. Planing Slots, key ways & Grooves

182

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

183

WORK

PLANER TABLE

Planing Horizontal Surfaces

TOOL

CLAPPER BLOCK

184

Planing Vertical Surfaces

Fix the job on the table firmly Align the surface to be machined properly Vertical side 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

185

Planing Vertical Surfaces

PLANER TABLE

WORK

186

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

187

Planing Angular Surfaces

188

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

189

TOOL

WORK

PLANER TABLE

Planing Formed Surfaces

190

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

191


PLANER TABLE

WORK

1. Heavier, more rigid costlier machine.

2. Requires more floor area.

3. Work reciprocates horizontally.

4. Tool is stationary during cutting.

5. Heavier cuts and coarse feeds can be employed.

6. Work setting requires much of skill and take longer time.

7. Several tools can be mounted and employed simultaneously, usually four as a maximum facilitating a faster rate of production.

8. Used for machining large size work pieces.

1. A comparatively lighter and cheaper machine.

2. Requires less floor area.

3. Tool reciprocates horizontally

4. Work is stationary during cutting.

5. Very heavy cuts and coarse feeds cannot be employed.

6. Clamping of work is simple and easy.

7. Usually one tool is used on a shaper.

8. Used for machining small size work piece comparatively

Comparison between planer and shaperShaperPlaner

Shaper slotter planer

Engineering

Transcript of Shaper slotter planer