A

SUMMER TRAINING REPORT

ON

FOUNDARY MANUFACTURING ASSEMBLY

OF

HMT MACHINE TOOLS LTD, AJMER (RAJ.)

GOVT. ENGINEERING COLLEGE, BHARATPUR

(AN AUTONOMOUS INSTITUTE OF GOVT. OF RAJASTHAN)

BACHELOR OF TECHNOLOGY

MACHANICAL ENGINEERING

2015-2016

Submitted By:- Submitted To:- GULSHAN KUMAR Er. RAHUL SHRIVASTAV

12EELME023 HEAD OF DEPARTMENT

YEAR - 4th

Year (VII SEM.) MECHANICAL ENGINEERING

MECHANICAL ENGINEERING

MECHANICAL ENGINEERING DEPARTMENT

GOVERNMENT ENGINEERING COLLEGE, BHARATPUR

(AFFILIATED BY RAJASTHAN TECHNICAL UNIVERSITY)

GOVT. ENGINEERING COLLEGE BHARATPUR

(AN AUTONOMOUS INSTITUTION OF GOVT OF RAJASTHAN)

DEPARTMENT OF MECHANICAL ENGINEERING

SESSION: 2015-16

Certificate

This is to certify that _____GULSHAN KUMAR________ of B-Tech IV year

ROLL NO. ___12EELMEO23__ Branch Mechanical Engineering has

Successfully Submitted Summer training Report.

HEAD

MECHANICAL ENGINEERING

DEPARTMENT

ACKNOWLEDGEMENT

I would like to thank the entire HMT limited who has provided me

this nine weeks training. I am thankful to the HRD officer of training

centre who organized my training schedule and also the DGM’s and AGM’s of various shop departments who have provided me the various knowledge about their respective shops.

I also thanks to the workers of their respective departments, who

were always ready to clarify our doubts and helped us to increase our

knowledge by illustrating us to the finer points.

I wish to express my deep gratitude to all the concerned persons,

whose co-operation and co-ordination have given me the success to

complete my training in organization.

I hope that my report will reflect our technical knowledge and

innovativeness, which we gained at HMT MACHINE TOOL

LTD,Ajmer.

Gulshan Kumar

Mechanical Engineering

Roll No. 12EELME023

PREFACE

Industrial training is part and parcel of every technical course and

gives a face or form to all the theoretical knowledge we gain in our

classroom. We get to have a virtual experience of the processes,

methods, objects and phenomenon which used to be just an imaginary

picture in our minds. It also gives an exposure to the environment of the

industries and workshops which are virtual components of our

professional life. We too were provided with this opportunity this

summer.

We are thankful to our college administration that handed this

invaluable chance to us and at the same time we pay our regards to the

administration of HMT Ajmer (Machine Tools Division) that proved to

be a great supporting force for the fulfillment of the purpose. The

officials and the workers of the firm provided us with the best of their

attention and share ample of knowledge of their concerned field with us.

GULSHAN KUMAR

MECHANICAL ENGINEERING

12EELME023

Index

1. Chapter-1

1.1Introduction – Fulcrum of Indian Industrial Development

1.2 HMT at A Glance

1.3 HMT Machine Tools Division, Ajmer

2. Chapter-2

2.1 Different Department Of HMT

3. Chapter-3

3.1 Foundry Department

(A) Pattern Shop

3.1.1 Pattern Making

3.1.2 Sand Mould and Core Making

(B) Melting Department

3.1.3 Metal Melting

3.1.4 Casting and Separation

3.1.5 Removal of Runner and Riser

3.1.6 Finishing

3.1.7 Sand Recovery and Reclamation

4. Chapter-4

4.2 Manufacturing department

4.2.1 MMS (Medium Machine Shop)

4.2.1.1 Milling Machine (H & V-milling)

4.2.1.2 Lathe Machine (Centre & Turret)

4.2.1.3 Boring Machine

4.2.1.4 Radial Drilling Machine

4.2.1.5 Surface and Cylindrical Machine

4.2.1.6 Honing Machine

4.2.1.7 Shaper Machine

4.2.2 ROUNDS SHOP

4.2.2.1 Internal Grinding Machine

4.2.2.2 Surface Grinding Machine

4.2.2.3 Rotary Grinding Machine

4.2.2.4 Cylindrical Grinding Machine

4.2.2.5 Slotter

4.2.2.6 Gearing

4.2.3 HDMS (HEAVY DUTIES MACHINE SHOP)

4.2.3.1 Planning

4.2.3.1.1 Double Housing Planer

4.2.3.1.2 Open Slide Planer

4.2.3.1.3 Plano Milling Machine

4.2.3.2 Boring

4.2.4 TOOLS ROOM

4.2.4.1Veriner Caliper

4.2.4.2 Micrometer

4.2.4.3 Dial Indicator

5. Chapter-5

5.3 Assembly Department

5.3.1 GPM Section

5.3.2 CNC Section

5.3.2.1 Assembly

5.3.2.2 Machine Description

5.3.2.2.1 Bed Type Machine Configuration

5.3.2.2.2 Linear Motion with Guide Ways

5.3.2.2.3 Open Package Design

5.3.2.2.4 Long Nose Quill Type Spindle

5.3.2.2.5 Spindle Cooling

5.3.2.2.6 Step-less AC Spindle Motor

5.3.2.2.7 Electronic Orientation

5.3.2.2.8 AC Servomotor

5.3.2.2.9 Lubrication

5.3.2.2.10 Automatic Chip Collection

5.3.2.2.11 Guide Protection

5.3.2.2.12 Automatic Tool Changer

5.3.2.2.13 Numerical Head Counter Balance

5.3.2.2.14 Machining Features

6. Chapter-6

6.1 Bibliography

Chapter-1

INTRODUTION

Fulcrum of Indian Industrial Development:

When India achieved independence in 1947, there was hardly any

industrial base in the country. Right form the prior H.M.T. has played an

important role in providing the much needed industrial base as well as a

launching pad for the growth & development of the country.

HMT was conceived by the Government of India in 1949, and was

incorporated in 1953, with the objective of producing a limited range of

machine tools, required for building an industrial edifice for the country.

HMT Limited was established in 1953 in technical collaboration with

M/s Orleikon of Switzerland. Over the years, new products have been

added to its manufacturing range. It has technical collaboration with

over 30 leading International Engineering Companies for manufacture of

various products HMT’s diversified product range includes Machine Tools, Watches, Tractors, Printing Machine Press, Di-Casting and

Plastic Injection, Moulding Machines, Food Processing Machinery,

CNC Systems, Bal Screws etc.

This Unit was established as Machine Tool Corporation of India limited

in January 1964 keeping in view the Government Policy of differing

new industries in under developed areas of the country and achieving

self reliance in production of Grinding Machine Tools which were

imported.

This Unit was started 1970-71 with a production of Rs. 8.64 Lack faces

with difficulty in procurement of quality Machine Tool Casings a

captive Foundry Plant was installed in 193 with a capital of about Rs.2

Crore.

This Unit was subsequently merged with HMT Ltd. On 1st April 1975

as sixth Machine Tool Plant with this merger; the Unit got backup

support of HMT. The basic plant was established with the collaboration

of the Czechoslovakian firms, M/s Skoda Export, Praha and German

firm WMW, then in East Germany.

HMT’s commitment to the development of the machine tools technology is clearly reflected in the fact that HMT has as many as

seven exclusive machine tool units, spread across the country. Each

superbly equipped to meet the most challenging demand for machine

tools. These units are in Ajmer, Banglore, Pinjore, Kalamassery, and

Hyderabad are all ISO 9000 certified.

Today HMT is well positioned at the fore front of the precision

engineering field. Its manufacturing plants employ highly skilled

workforces strongly supported by R&D. Today over 780000 machine

tools manufactured by HMT are in used in India and elsewhere.

In tune with changing business environment, HMT limited

restructured into holding company tractors as its core business and the

following subsidiaries:

HMT Machine Tools Limited,

HMT Watch Limited,

HMT Bearings Limited,

HMT Chinar Watches Limited,

HMT (International) Limited,

Praga Machine Tools Limited.

1.1 HMT AT A GLANCE

Date of Registration 11-01-1967

Commencement of Production 1970-71

Merger with HMT 1-04-1975

Capital Employed (as on 1.4.2007) 201 Lacs.

Land Area –Total 178 Acres

Plant Foundry 62 Acres

Township 116 Acres

Covered Area (Plant) 31848 Sq. Mtrs.

No. of Quarters 136

Power Required 4.00 Lacs Units/Month

No. of Employees (as on 01.04.2011) 381

No. of Machines 250

ISO-9001 Certified 1994

factory campus 166 acres : for township 136 quarters : for housing its

employees]

Cost of Machines working in the unit 6 Lacs up to 1 CR.60 Lacs

No. Of machine shops 180

Working shifts 4 [‘A’ shift - (6.00am to

2.00pm) ‘B’ shift - (2.00pm to 10.00pm) ‘C’ shift - (10.00pm to

8.00am)

HMT, MACHINE TOOLS DIVISION, AJMER

Profile of the Unit

Name of the Company HMT MACHINE TOOLS LIMITED

Name of the Unit Machine Tools Division

Location Ajmer, Rajasthan

Major Products:

Wide range of CNC Conventional, General Purpose & Special Purpose

Grinding Machines (Cylindrical, Centreless, Internal, Crankshaft,

Double Disc, Duplex, Horizontal & Vertical, Tool & Cutter) CNC

Turning Centres PUSHKAR CNC Training Lathes & Machining

Centres Reconditioning & Refurbishing

Major Manufacturing Facilities:

Machine Shop equipped with Machining Centres, CNC Turning

Centres, Jig Boring Machine, Honing Machine, Superfinishing

Machines Measuring Centre Materials Testing Laboratory CAD Centre

Foundry.

Working Hours (General Shift) : 0830 Hrs. to 1630 Hrs.

Weekly Holiday: Sunday

Chapter-2

DIFFERENT DEPARTMENTS OF HMT, AJMER

Foundry

Manufacturing

Assembly

Maintenance

Inspection

MMS

ROUNDS

HDMS

TOOLS ROOM

K130

GCL

GDS

GTC

ELECTRICAL ASSEMBLY

Chapter-3

3.1. Foundry Department

Headed by AGM Foundry. This department is administratively

under HMT Ajmer, but functionally under executive director.

HMT’s foundry shop comprises of two units:

One is the captive foundry, meant for the small production of

casting having weight upto 4 tonnes. The capacity of this foundry

is 1000 MT per annum.

And the other is meant for mass production of comparatively

smaller tractor and machine components. The capacity of this

foundry is 2000 MT per annum.

(A) PATTERN SHOP

3.1.1 Pattern making

In casting, a pattern is a replica of the object to be cast, used to

prepare the cavity into which molten material will be poured during the

casting process.

Patterns used in sand casting may be made of wood, metal, plastics or

other materials. Patterns are made to exacting standards of construction,

so that they can last for a reasonable length of time, according to the

quality grade of the pattern being built, and so that they will repeatably

provide a dimensionally acceptable casting.

Patterns provide the exterior (mould) or interior (core)shape of the

finished casting and are produced in wood,metal or resin for use in sand

mould and core making. Patterns are usually made in two halves.

Fig. Pattern of motorcycle-yolk

3.1.2. Sand mould and core making

In HMT due to complex structure of components (such as gear

box) are produced with the help of master pattern. Here core is first

made with the help of master pattern after which the core is allowed to

be baked.

Sand casting is the most common production technique, especially for

ferrous castings. Sand is mixed with clay and water or with chemical

binders and then packed or rammed around the pattern to form a mould

half. The two halves are joined together to make the mould - a rigid

cavity that provides the required shape for the casting.

The core is made with the help of sand such as

Rigid coated sand in shell core machining.

Air setting sand or no bake sand.

Green sand.

Here the gear box is made with no bake/air setting sand which is

prepared by mixing different constituents.

Here the prepared core (made from master pattern) is allowed to

solidify.

Smaller core is baked with the help of shell core machine, which

has a box containing rigid coated sand. When allowed to operate the

front assembly rotates and the box moves upward from which the

sand falls in the die (die used according to shape of core required)

here die can be changed.

Now the core is put in cope, drag and the molten metal is poured

after which pattern can be easily obtained.

Fettling:

Fettling is the process by which the pattern obtained is given the desired

finish by various processes. Before fettling, the casting obtained is

subjected to removal of projections, chips, core, runner, riser etc. by the

following processes:

Decoring

Chipping

Shot blasting (for heavy pattern)

Wheel abrasion (for small pattern)

Decoring:

Decoring is the process of removing the fused sand.

Chipping:

Chipping is the process of removing the runner, riser etc.

Shot Blasting & Wheel Abrasion:

Shot blasting or wheel abrasion is used for removing the sand particles

by the usage of air.

After this fettling is done by the following process:

Pneumatic gun- to remove corner sand.

Angle grinder- to give corner finish.

Die grinder- to give finish to inner portion.

Pedestal grinder-to give surface finish.

While making casting for gears, surface finish is not required because

gear has to be cut on it with the help of milling machine after which it is

grinded.

Priming & Painting:

After clean and fettling, the casting is subjected to priming and painting

to prevent corrosion.

(B) Melting Department

3.1.3 Metal melting

The process of melting in HMT is carried out in induction furnaces at a

temperature of about 1400°-1450° C.

Process:

At first the induction furnaces are coated with fine cement clay. Now

metal scrap is inserted in the furnace and slag coagulant is added to it.

The requisite amount of coke is added to it. The current is supplied to

copper coils provided in the furnace which induce current in the metal

scrap and the scrap gets heated up, when the melting temperature is

reached the molten metal is collected in ladles and taken to the pouring

zone. When this process is being carried out the copper coils are

regularly cooled with coolant (water) so that the coils do’not melt due to the high temperature generated in the coils.

The foundary of HMT has three furnaces, two, each having capacity

of 3MT and one of 1.5MT. The two types of induction furnaces are:-

Main frequency Induction Furnace(50Hz)

Medium frequency Induction Furnace(250Hz)

Melting of metal ion medium frequency furnaces are faster than the

main frequency furnaces. Molten metal is prepared in a variety of

furnaces, the choice of which is determined by the quality, quantity and

throughput required.

Electric induction furnaces are the most common type used for batch

melting of ferrous, copper and super alloys. This method involves the

use of an electrical current surrounding a crucible that holds the metal

charge. Furnace sizes range from < 100 kg up to 15 tonnes. For

production of super alloys and titanium, melting may be undertaken in a

vacuum chamber to prevent oxidation .

Fig. Electrical furnace

3.1.4 Casting and separation

Molten metal is poured into moulds using various types of ladles, or in

high volume production, automated pouring furnaces. Metal is poured

into the “runner” (a channel into the mould cavity) until the runner bush is full. The “riser” provides an additional reservoir of feed metal to

counteract the shrinkage that occurs as the casting begins to cool.

When the metal has cooled sufficiently for the casting to hold its shape,

it is separated from the mould by mechanical or manual methods. Where

sand moulds are used, the process is often referred to as shakeout or

knockout, and large amounts of dust may be generated.

3.1.5 Removal of runners and risers

A riser, also known as a feeder, is a reservoir built into a metal

casting mold to prevent cavities due to shrinkage. Most metals are less

dense as a liquid than as a solid so castings shrink upon cooling, which

can leave a void at the last point to solidify.

Risers prevent this by providing molten metal to the casting as it

solidifies, so that the cavity forms in the riser and not the casting. Risers

are not effective on materials that have a large freezing range, because

directional solidification is not possible.

They are also not needed for casting processes that utilized pressure to

fill the mold cavity. A feeder operated by a treadle is called an

underfeeder.

After casting, these extraneous pieces of metal are rem oved and often

collected for re- melting. In ferrous castings and larger non-ferrous

castings, they may be removed by knocking off, sawing or cutting using

an arc air or oxy-propane torch. In die-castings, they are often snapped

off manually.

3.1.6 Finishing

A range of finishing processes is usually undertaken. These include:

♦ cleaning to remove residual sand, oxides and surface scale, often by

shot or tumble blasting;

♦ heat treatment, including annealing, tempering, normalising and

quenching (in water or oil) to enhance mechanical properties;

♦ removal of excess metal or surface blemishes, (e.g., flash resulting

from incomplete mould closure or burrs left from riser cut-off), by

grinding, sawing or arc air (oxy-propane cutting);

♦ rectification of defects by welding;

♦ machining;

♦ non destructive testing to check for defects;

♦ priming, painting or application of a rust preventative coating.

3.1.7 Sand recovery and reclamation

The industry recycles a large proportion of mould and core making sand

internally for re-use. This involves processing to remove tramp metal

and returns the sand to a condition that enables it to beused again for

mould or core production .

Chapter-4

4.2. Manufacturing Department

Headed by AGM (manufacturing). HMT Ajmer’s manufacturing environment is highly advanced; this department also looks after

utilizing only the latest production techniques in all phases of

manufacturing maintenance.

MACHINE FEATURES

Bed made of high tensile strength cast iron, heavily ribbed for

better vibration damping and shock absorption.

Precision, widely placed V & flat guideways for table with

continuous automatic lubrication. Turcite lining for G17.

Grinding wheel head spindle runs in a high precision

hydrodynamic bearing.

Higher powered wheel head for production model for high rate of

stock removal.

Spindle is nitrided and super finished for reliability and life.

Precision, V & Flat guideways with turcite for infeed slide for

better damping & higher repeatability.

Automatic infeed at table reversal for traverse grinding operation.

Auto plunge grinding cycle consisting of rapid approach, coarse

feed, fine feed, spark out and rapid retraction.

Single piece robust construction with long guided sleeve for better

rigidity of tailstock.

Independent drive for internal grinding attachment.

Single push button control cycle.

4.2.1 MMS (Medium Machine Shop)

In HMT, Ajmer; It is the medium machine shop which gives the shape

to the castings which come from the foundry after being painted rough.

In this section various operations are performed for making small parts

of machines by the help of lathe (V-Turret & Centre lathe), milling,

drilling, boring and surface grinding machines. In it first of all the jobs

are marked, checked so that machining time is saved if the casting size is

oversized.

There are many types of machines are available for performing

operation like as cutting, drilling, milling, grinding etc. Each machine is

used for different operation purpose.

The main machines in shop are:

Milling (H & V-milling) Machine

Lathe (Centre & V-Turret) Machine

Vertical Boring Machine

Radial Drilling Machine

Surface & Cylindrical Grinding Machine

Honing Machine

Shaper Machine

4.2.1.1 Milling Machine (H & V-milling)

Milling is the machining process of using rotary cutters to remove

material from a workpiece advancing (or feeding) in a direction at an

angle with the axis of the tool.

It covers a wide variety of different operations and machines, on scales

from small individual parts to large, heavy-duty gang milling operations.

It is one of the most commonly used processes in industry and

machine shops today for machining parts to precise sizes and shapes.

V-Milling Machine

Fig. V-milling Machine

Vertical milling machine. 1: milling cutter 2: spindle 3: top slide or

overarm 4: column 5: table 6: Y-axis slide 7: knee 8: base

In the vertical mill the spindle axis is vertically oriented. Milling

cutters are held in the spindle and rotate on its axis. The spindle can

generally be extended (or the table can be raised/lowered, giving the

same effect), allowing plunge cuts and drilling.

H-Milling Machine

A horizontal mill has the same sort but the cutters are mounted

on a horizontal arbor ( Arbor milling) across the table.

Many horizontal mills also feature a built-in rotary table that allows

milling at various angles; this feature is called a universal table.

4.2.1.2 Lathe Machine (Centre & V-Turret)

A lathe is a machine that shapes pieces of material. Usually the

material being molded is wood or metal, and is referred to as the "work."

The most common lathes are centre lathe.

The sits between two parts of the lathe called the headsock and the

tailsock. The two parts hold the work in place and spin it quickly. When

using centre lathes the pieces are shaped by tools with a single point

cutting tools, while lathes that shape other materials, such as metal, have

tool attached to an adjustable carriage that holds the cutting tools in

contact with the spinning metal.

Main operation perform on Lathe machine are:

Turning

Taper turning

Threading (External & Internal)

Boring

Grooving

Drilling

Facing

Knurling

Taping (internal thread cutting) etc.

Turret Lathe

It allow multiple cutting operations to be performed, each with a

different cutting tool in easy, rapid succession, with no need for the

operator to perform setup tasks in between, such as installing or

uninstalling tools, nor to control the toolpath. The latter is due to the

toolpath's being controlled by the machine, either in jig-like fashion, via

the mechanical limits placed on it by the turret's slide and stops, or via

electronically-directed servomechanisms for computer numerical control

lathes.

4.2.1.3 Boring Machine

Boring is the operation of enlarging an already drilled hole. The

holes are pre-drilled as in casting only.

Machining time in boring:-

Machining time is the time required to complete the work place in

a request period of time.

Time required = Length of cut/(RPM × feed per meter)

Machines installed

Horizontal Boring Machine

Vertical Boring Machine

Jig Boring Machine

Horizontal Boring Machine

In the horizontal boring machine, operations are performed on

those large components which cannot be rotated. The spindle and the

boring bar are horizontal.

It has mechanical system and fixture is attached with table. The

work table can be transverse along and across the machine bed.

Vertical Boring Machine

The spindle is vertical and bores vertical holes in the spindle. The

size of the machine is determined by maximum length of the job which

can be machined on it. The machine can also be used as a drilling

machine.

Jig Boring Machine

Jig boring machine is used to accurately enlarge existing holes and

make their diameters highly accurate. Jig boring can also maintain high

accuracy between multiple holes and surfaces.

Tolerances can be held readily within ±0.002mm. The machine can also

do accurate milling, reaming, drilling and facing,

In general, the vertical jig boring machine employs a precision

vertical tools spindle and coordinate work table with a great accuracy.

The position measuring system consists of accurate lead screw with

micrometer and an optical scale along with a vernier.

The machine are of rail type i.e. they are constructed with a cross

rail that is supported and adjusted vertically on two columns. The cross

rail serves to carry vertical spindle in its housing along the transverse

axis.

4.2.1.4 Radial Drilling Machine

A radial drilling machine or radial arm press is a geared drill head

that is mounted on an arm assembly that can be moved around to the

extent of its arm reach.

The most important components are the arm, column, and the drill

head. The drill head of the radial drilling machine can be moved,

adjusted in height, and rotated.

Aside from its compact design, the radial drill press is capable of

positioning its drill head to the work piece through this radial arm

mechanism.

Salient Features :

» Massive and rigid construction.

» Ergonomically grouped controls for operating convenience.

» Light centering of spindle.

» Precise depth release.

» Electrohydraulic clamping provided for drill head, arm & sleeve.

» Shock-free engagement of taps through clutch and spindle reverse for

withdrawals.

» Machine with drilling capacity 80 mm / 100 mm also available.

Fig. Radial Drilling Machine

Specifications :

RM 62 RM 63 RM

65

Drilling

Capacity

In Steel

In Cast Iron

mm

mm

50

60

50

60

50

60

dia 100

(At 60 rpm

with

0.5 mm/rev.

dia.125

(at 60 rpm

with 0.62

mm/rev)

Drilling depth Mm 325 325 325

Tapping In Steel

In Cast Iron

M56x2.5 or BSW 1-3/4

M70 or BSW 2-1/2"

dia. 80 dia.

100

Boring

In Steel

In Cast Iron

dia. 250 dia.

300

Spindle speeds Rpm 12:40-1800 32:10-1545

Spindle feeds no:mm/rev 6:0.125-1.25 18:0.075-4

Max. drilling

radius

Mm 1500 1790 2350

Main motor Kw 3.6 / 4.5 20

4.2.1.5 Surface And Cylinder Grinding Machine

Grinding Machines are also regarded as machine tools. A distinguishing

feature of grinding machines is the rotating abrasive tool.

Grinding machine is employed to obtain high accuracy along with

very high class of surface finish on the workpiece.

However, advent of new generation of grinding wheelsand grinding

machines, characterised by their rigidity, power and speed enables one

to go for high efficiency deep grinding (often called as abrasive milling)

of not only hardened material but also ductile materials.

Conventional grinding machines can be broadly classified as:

(a) Surface grinding machine

(b) Cylindrical grinding machine

(c) Internal grinding machine

(d) Tool and cutter grinding machine

Fig. Cylindrical Grinding Machine

4.2.1.6 Honing Machine

Honing is an abrasive machining process that produces a precision

surface on a metal workpiece by scrubbing an abrasive stone against it

along a controlled path.

Honing is primarily used to improve the geometric form of a surface,

but may also improve the surface texture.

Typical applications are the finishing of cylinders for internal

combustion engines, air bearing spindles and gears.

There are many types of hones but all consist of one or more abrasive

stones that are held under pressure against the surface they are

working on.

4.2.1.7 Shaper Machine

A shaping machine is used to machine surfaces. It can cut curves,

angles and many other shapes. It is a popular machine in a workshop

because its movement is very simple although it can produce a variety of

work.

The tool feed handle can be turned to slowly feed the cutting tool into

the material as the 'ram' moves forwards and backwards. The strong

machine vice holds the material securely.

A small vice would not be suitable as the work could quite easily be

pulled out of position and be damaged. The vice rests on a steel table

which can be adjusted so that it ca be moved up and down and then

locked in position. Pulling back on the clutch handle starts the 'ram'

moving forwards and backwards.

4.2.2 ROUNDS SHOP

This section concerned with the round job construction and

working. The section involves operation like grinding, slotting, drilling

etc.

Following are the lists of machines and operations concerned with

them:-

4.2.2.1 Internal Grinding Machines

Concerned with grinding of inner surface of job.

4.2.2.2 Surface Grinding Machines

Concerned with outer surface of job. It uses magnetic chuck and

shows only horizontal motion of the table at the bed.

4.2.2.3 Rotary Grinding Machines

Concerned with horizontal as well as rotational movement of the

table. It also uses magnetic chuck.

4.2.2.4 Cylindrical Grinding Machine

This is used to grind cylindrical jobs with the motion of grinder

itself. This job is held in the jaw chuck.

4.2.2.5 Slotter

This machine is concerned with slot cutting. It uses carbide tip and

shows vertical motion of the tool for slot cutting.

The other machines concerned with this section are lathes, drilling

machines etc.

4.2.2.6 Gearing

Gear is used for power transmission of different parts of machines.

This section is concerned with teeth cutting. Proper indexing is

maintained in the process with fixtures on the machines concerned.

There are four types of gears used in manufactured here:-

1. Spur gear

2. Worm gear

3. Helical gear

4. Bevel gear

The various machines involved are:-

Milling Machine

Generally used for manufacturing of spur gears. Cutters of

prescribed sizes are used.

Gear Hobbing Machines

Gear hobbing machine is used for manufacture of worm gear. It

uses hydraulic action.

Broaching Machine

Broaching machine is used to put splines in gear.

Gear Teeth Grinding Machines

It is used for grinding the teeth of the gears. In this machine gear teeth

are grinded by a worm type grinding wheel. Here the tooth profile are

checked with a machine called gear tooth profile tester.

4.2.3 HDMS (HEAVY DUTIES MACHINE SHOP)

It is the shop which gives the shape to the largest castings which

come from the foundary after being painted rough. In this section

various operations are performed by the help of planers, boring and

planning-boring machines.

In this section, first of all the jobs are checked for the castings to

be over-size or undersize. If they are undersize, they are sent to scrap. If

they are oversize, they are marked and sent for machining.

Different types of operations are done by using different machines

including various measuring devices.

This section also includes in itself a high technology section in

which advanced machines are placed to machine crucial parts generally

guide ways etc. It accommodates a tool preset device which is used to

set the tool of all machines and CNC machines. It is used to measure the

length and diameter of the tool with the help of leases.

This section is generally divided into two sections:

Planning

Boring

4.2.3.1 Planning

This section consists essentially of planers mounted on one side of

the section. In this section the job planning is one of the basic operations

done for machining process. It is primarily intended for machining large

flat surfaces.

Machines Installed

Double Housing Planer

Open Side Planer

Plano Milling Machining

Horizontal Turning Centre

4.2.3.1.1 Double Housing Planer

This is the heavy type of planer and is used for heavy cuts by

double cutters. Its length is 3000mm. It consists of two columns, one on

each side of bed. The cross rail is fitted between the two housings which

can accommodate one or two heads, according to the specifications.

4.2.3.1.2 Open Side Planer

This type of planer consists of a single column situated vertically

on one side of the bed and other side is left open without any column.

The cross-rail is wholly supported on the single column. Only one

tool head can be located on it as there is only one column.

4.2.3.1.3 Plano Milling Machine

This is similar to a double housing planer but the tool can be

milling tool. One of the machines is TNC (three axis turning centre) in

which only one axis can be moved at a time. Thus round jobs cannot b

machined here.

Another machine is CNC in which two axis can be moved

simultaneously to machine round job. The length of the bed is 2800mm.

4.2.3.2 Boring

This is already discussing in MMS section.

4.2.4 TOOLS ROOM

This department keeps various kinds of tools which are useful during

manufacturing of heavy pats. Most of the tools are measuring devices

such as vernier caliper, micrometer etc.

4.2.4.1 Vernier Caliper

A vernier caliper is a device used to measure the distance between

two symmetrically opposing sides.

The tips of the caliper are adjusted to fit across the points to be

measured, the caliper is then removed and the distance read by

measuring between the tops with a measuring tool, such as a ruler.

Vernier calipers can measure internal dimensions (using the uppermost

jaws in the picture), external dimensions using the pictured lowered jaws

and depending on the manufacturer, depth measurements by the use of a

probe that is attached to the movable head and slides along the center of

the body. This probe is slender and can get into deep grooves that may

prove difficult for other measuring tools.

The vernier scale may include both metric and inch measurements

on the upper and lower part of the scale.

Vernier calipers commonly used in industry to provide a precision

to a hundredth of a millimeter (10 micrometers), or one thousandth of an

inch.

Parts of Vernier caliper

Outside Jaws: used to measure external diameter or width of an

object

Inside Jaws: used to measure internal diameter of an object

Depth Probe: used to measure depth of an object or an hole

Main Scale: gives measurements of up to one decimal place (in

cm)

Main Scale: gives measurements in fraction (in inch)

Vernier gives measurements up to two decimal places (in cm)

Vernier gives measurements in fraction (in inch)

Retainer: Used to block movable part to allow the easy

transferring a measurement.

4.2.4.2 Micrometer

A micrometer sometimes known as a “Micrometer Screw Gauge”, is a device used widely in mechanical engineering and machining as

well as most mechanical trades for precision measurement, along with

other metrological instruments such as dial calipers and vernier calipers.

Micrometers are often, but not always, in the form of calipers.

Types of Micrometer:

Outside Micrometer (aka micrometer caliper), typically used to

measure wires, spheres, shafts and blocks.

Inside Micrometer, used to measure the diameter of holes.

Depth Micrometer, measures depths of slot and steps.

Bore Micrometer, typically a three-anvil head on a micrometer

base used to accurately measure inside diameters.

Tube Micrometer, used to measure the thickness of tubes.

4.2.4.3 Dial Indicator

Dial indicators, also known as dial gauge and probe indicators, are

instruments used to accurately measure small linear distances, and are

frequently used in industrial and mechanical processes. They are named

as so because the measurement results are displayed in a magnified way

by means of a dial.

Dial Indicator may be used to check the variation in tolerance

during the inspection process of a machined part, measure the deflection

of a beam or ring under laboratory conditions, as well as many other

situations where a small measurement needs to be registered or

indicated. Dial indicators typically measure ranges from 0.25mm to

300mm (0.015in to 12.0in), with graduations of 0.001mm to 0.01mm

(metric) or 0.00005in to 0.001in (empirical).

Chapter-5

5.3. Assembly department

5.3.1 GPM Section

GPM stands for general purpose machines. These are generally

manually worked machines involving no computerized or numerical

control. These machines are semiautomatic in nature and some of its

operation like table movement, job movement, tool movement etc. can

be carried out either automatically or even manually.

These are operated by concerned operations only. The concept of

modern days machines originated from GPMs itself.

These are the simplest form of the metal working machines.

Main machine in this section are:

K130

GCL (Centre-less Grinding)

GDS (Double Surface Grinding)

GTC (Tool Cutter Grinding)

5.3.2 CNC SECTION

Introduction

We know that GPMs are semi-automatic machines. They require an

operator for each work piece loaded on machine and in a limited period.

Mass production is not possible in these machines. Moreover complex

shaped jobs require high precision. They need for flexible automation

has always been felt. And this is an era of machine tool automation. So,

flexible automation is implemented in machine tools in the form of NC

and CNC (Computerized Numerical Control) technology . Today HMT

is producing a lot of CNC variants of conventional machine tools with

the specialized functions and mostly CNC products.

CNC machines are part of the field named mechatronics. This field is the

combination of electronics and mechanical engineering fields. When

they work in combination they are termed as above. A single CNC

machine can perform variety of machining operations in a sequential

order (based upon the programme). For example drilling , tapping ,

slotting, milling, etc. operator is used only for clamping and declamping

purpose ( after feeding the programme ). These machines ensure

repeatability of the dimensions (precision). Accuracy of these machines

is in microns.

A CNC machine may be of three dimensional coordinate system with

XYZ axis. Rest two are available on machines whose table can rotate

and tilt. These are 4th

and 5th

axis. The axis of the spindle is termed as Z

axis. The axis which crosses Z axis perpendicularly is X axis and the

other mutually perpendicular axis is Y axis. CNC machines differ in

orientation of the main spindle. If spindle is horizontal it is termed as

HMC (horizontal machining centre) and if the spindle is vertical it is

termed as VMC (vertical machining centre). Model number of machine

depends upon capacity of machine. Capacity means traverse length

along various axis or maximum size of the pallet. Thus a VTC 1000

designates a CNC machines whose spindle is vertical with pallet size or

traverse length of 1000mm.

5.3.2.1 Assembly

Main parts of the CNC machine are:-

1. Bed

2. Column

3. Saddle

4. Table

5. Pallet chaner (optional)

6. Magazine

7. AC servo motors

8. Tool changer arm

9. Head

10. Main spindle

The different processes of assembly are:-

1. Procurement of various parts.

2. Bed is leveled.

3. Column is fixed on bed.

4. Ball screws and drive motors are installed.

5. Alignment of column w.r.t. bed.

6. Fixing table on saddle.

7. Installing ball screws and drive motor.

8. Alignment of saddle w.r.t. column.

9. Fixing table on saddle.

10. Laser test:- In this test the laser beam is thrown on the pairs of

prism one attached to the table and other on the spindle of the machine

and reflected back through the same part and data is collected on the

computer and thus can be corrected.

11. Tool magazine is assembled and attached to the machine.

12. The oiling system is attached to the machine as separate apparatus

and solves the purpose of lubrication .

13. All electrical and electronics appliances are installed.

14. The body of the machine is and rest of the accessories are attached to

it.

15. Final inspection is done.

5.3.2.2 Machine Description

Salient features of CNC machines are as follows:-

5. 3.2.2.1 Bed type machine configuration

Bed type construction with longitudinal and cross movement to

work table and vertical movement to head , provides stable cutting

condition and maximum rigidity. Box type construction of bed and

column with properly ribbed reinforcement minimizes torsion and

flexural deflection.

5.3.2.2.2 Linear motion with guide ways

Preloaded anti - friction linear motion type. Guide ways in the entire

three provide clearance free guidance for slides during cutting. Their use

significantly reduces the coefficient of friction and eliminates stick slip

and thermal generation during high speed positioning. In addition they

offer high positioning and outstanding contouring capability.

5.3.2.2.3 One package design

One package design i.e. integral mechanical- electrical construction

with CNC unit mounted on machine guarding, substantially cuts down

floor space requirements. This enhances productivity per unit area and

assures easy machine movement when production line is changed.

5.3.2.2.4 Long nose quill type spindle

Cylindrically shaped head end and prevents any interference with the

work complicated shape. This configuration also eliminates interference

even with large steep work. Machining of deep holes in the work are

also possible with full power and without compromising tool rigidity.

5.3.2.2.5 Spindle cooling( for machine with spindle speed of 6000

rpm)

Circulation of cooled oil through the oil jacket around the main

spindle bearing, maintains precision even in long and continuous runs.

5.3.2.2.6 Stepless AC spindle motor

AC spindle motor eliminates the troublesome brush inspections and

replacements required in case of DC motors. Another advantage of DC

motor is that it reduces electricaly consumption.

5.3.2.2.7 Electronic spindle orientation

The spindle motor has build in encoder for position feedback of the

spindle. Spindle orientation stops spindle in a particular position. This

helps in retracting bars without damaging bores in boring operations and

counter-boring/Facing. Automatic tool change is also achieved through

the features.

5.3.2.2.8 AC servomotors

All the three axes are driven through AC servomotors. Their use

provides a higher rapid rate of revolution with minimum maintenance.

They also provide high acceleration and deceleration property and

subsequently increase the machining efficiency.

5.3.2.2.9 Lubrication

Automatic lubrication is provided for minimal operator attention.

Main spindle bearing and all axes drive bearing are fitted with synthetic

grease, requiring no attention for long periods . All axes ball screws and

linear re-circulating bearings are also lubricated.

5.3.2.2.10 Automatic chip collection

Flushing coolant with discharge of 100lpm is used for automatic

flushing of chips and is collected in tray at rear of machine. Wide

channels with sufficient scope are provided in both sides of bed for easy

disposal of chips at rear of machine.

5.3.2.2.11 Guide protection

Guide ways protection with telescopic cover protects guide ways

against external damages and chips.

5.3.2.2.12 Automatic Tool Changer(ATC)

Machine is equipped with a suitable number of tool station/pocket

(mainly12,30,60,120) . Using cam the automatic tool changer changes a

tool accurately and swiftly.

3.2.2.13 Numeric head counter balance

It offsets the natural weight of spindle head and guarantees consistent

cutting,high speed and highly accurate positioning. It eliminates head

falling.

5.3.2.2.14 Machining Features

1. External coolant on spindle:- External coolant facilities the

machining of steel/aluminium. It also helps in taking away chips from

machining zone with its large flow.

2. Mist coolant:- Machining of light metals is faciliated with mist

coolant. Mist coolant takes away heat from work zone, with change of

state. It does not require any return path.

3. Chip conveyor:- It takes away large volume of chips produced

out of the machine continuously with its independent drive.

4. Refrigeration type of spindle coolant:- Coolant of cooled oil

with heat exchanger(refrigeration type), through spindle jacket provides

higher spindle stability which results in improved working accuracy.

5. Spindle mounted probe:- Spindle mounted probe with auto

measuring cycle and datum cycle makes fixture/job setting simple.

6. Higher speed spindle upto 8000 rpm :- It facilitates machining

of light metals with latest tool technology.

7. Pallet changer:- This part is concerned with handling of

additional table on which the next job can be mounted for machining

meanwhile machining of the current job is going on which considerably

reduces the mounting time.

Chapter-6

6.1 Bibliography

1. www.hmtmachinetools.com

2. www.hmtmachinetools.com\Ajmer-comlex

3. www.google.com

4. www.hi.wikipedia.org