HMT TRACTOR PROJET REPORT FOR SUMMER TRAINING

REPORT

On

Four Months Industrial Training

At

HMT Ltd. Pinjore(From 03 Jan., 2012 – 02 May, 2012)

Submitted to,Mr. V. K. Grover

Submitted by,Harshal R.Deshmukh

Sunil L.BhaleraoAmbadas M.Chalge

Bipin N.JadhaoSuraj V.Satao

College Of Agril. Engg. And Tech, Jalgaon Jamod, Dist:-Buldana(Maharashtra)

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ACKNOWLEDGEMENT

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

persons without whose generous cooperation and coordination, it would

have been very difficult for me to have a successful training experience in

the organization.

It would like to thank Mr. V. K. Grover for giving me a golden

opportunity of industrial training, which would help me to enhance my

technical skill and helps me a lot besides some technical skills.

I am extremely grateful to the management of HMT, Pinjore for

giving me an opportunity to pursue four months training in their reputed

organization. This provides me a wonderful and learning experience for

me to go through this training.

Finally, I would like to thanks all those colleagues who help me out

of intensifying my technical knowledge and provide satisfactory solutions

to my all queries.

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Index

Sr. no. Particulars Page no.

I. Section A

1. Introduction 4

2. Company profile 5-8

3. Training centre 9-10

4. Foundry Mechanism 11-14

5. Heavy Machine Shop 15-17

6. Light Machine Shop 18-20

7. Heat Treatment 21-22

8. Engine Assembly and Testing 23-35

9. Tractor Assembly 36-38

II. Section B

Project Work 39-51

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I. INTRODUCTION

The country, India, is basically an agricultural country where more

than 65 % of population population, enough food has to be produced.

This cannot be produced with our conventional bullock drawn

implements. So there was need felt to invent such machine which speeds

up the agricultural production. Due to this reason the tractor was

invented.

Before we start, it is necessary to know how the word ‘tractor’ is

derived. Prior to 1900, the machine i. e. tractor is known as traction

machine (pulling machine). After 1900, both the words joined by taking

‘tract’ from traction and ‘tor’ from motor calling ‘tractor’. The tractor is

the machine which is used for applying high traction.

In our country, tractors were started manufacturing in real sense

after independence and at present, we are self sufficient in meeting

demand of country’s requirements for tractors. At present in India, there

are different tractor producing factories present like Hindustan machine

tools, Punjab tractors, Kirloskar tractors, etc is directly or indirectly

connected to agriculture. Moreover for increasing

.

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II. COMPANY PROFILE

2.1 Birth of HMT

In 1949 the idea of public sector tools was commissioned to be a corner stone

for the government’s industrial development plans. This led to the birth of

HINDUSTAN MACHINE TOOLS at Bangalore in 1953 which started a single

machine tools factory to produce lathes at Bangalore, in collaboration with M/s

Oerlikon of Switzerland.

Next, the company widened its product range beyond lathes by entering into

technical collaboration with other international leaders in machine tools such as Fritz

Werner, Herman Kolb, Errantly Somua, Gildermeister, Liebherr etc.

The second machine tool unit was set up in Bangalore in 1961 making use of

the Company’s own resources. The company diversified itself when, in collaboration

with Citizen Watch Company of Japan, the first watch factory was setup in Bangalore

in 1962 to produce hand watches.

The third machine tool unit was set up in 1963 at Pinjore, Haryana to produce

milling machines. In next few years, Machine Tool Units were set up at Kalamessary

in Kerala and in Hyderabad. The Printing Machinery division was attached to

machine tools factory at Kalamessary to qualities Printing Machine.

HMT’s tractor business commenced its operations in 1971 in technical

collaboration with M/s MOTOKOV, Czechoslovakia because of the priority given to

the agriculture in the national development plan and to take advantage of the green

revolution. HMT started the operations with the manufacturing of 25 Hp tractors.

Over the years, it has developed tractors ranging from 25 – 75 Hp.

The unit in Hyderabad began to make lamps and lamp making machines in

1973 to cater to the growing needs of rural. This was followed by producing

automatic watches.

A third watches factory was established in Srinagar to manufacture hand

wound watches for men. In 1975, the company took over the machine tool

corporation of India’s unit in Ajmer, Rajasthan and its name was changed to HMT

Limited.

In 1975, a separate international scales network called HMT was set up

comprising of company’s own agencies as well as other sales agents in Australia,

Europe and America. This network was to handle the marketing strategy and

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operations of the company overseas and it also extended its services to the other

leading Indians and overseas engineering companies. Since then this international arm

of the company has set up the turkey project in Algeria, Indonesia, Iraq, Kenya,

Nigeria and Srilanka.

2.2 HMT’s Products

The main products produced by HMT ltd are –

Machine tools,

Watches,

Tractors,

Bearings,

Printing Machinery,

Die Casting Machinery.

The divisions of HMT are described below –

2.2.1 Bangalore

It produces lathes (both CNC and Non CNC), milling/ machining centers,

grinding machines, gear cutting machineries, simple drilling machines, special

purpose machines, die casting and plastic injection moulding.

It also produces refurbishing and retrofitting like heavy duty, turret lathe,

multi spindle drilling machines and fine boring machines.

The other application components include the jigs, fixtures, some radar and

transonic components. It also develops hinomerik control system, Hyderabad.

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2.2.2 Hyderabad

It produces the machining centers, CNC, Boring machines, milling machines,

die and mould machining centers, presses and brakes. It also produces special purpose

machines like CNC tube chamfering machines, cam shaft milling machines, filament

winding machines, horizontal and vertical coil winding machines, multi spindle

machining centers.

2.2.3 Kalamessary

It produces CNC lathes and printing machineries.

2.2.4 Ajmer

It produces grinders and lathes. It also manufactures some application

components like hydraulic lift mechanism for tractors, valve devices and oil priming

pump.

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The retrofitting includes center less grinders and double disc grinders.

After establishing two machine factories and a watch factory in Bangalore, the

Pinjore unit was established as the third machine tool factory. Breaking the ground on

2nd may, 1962, this factory

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III. TRAINING CENTRE

In training centre, the basic machines are studied such as Lathe Machine,

Milling machine, Drilling Machine, etc.

3.1 Structure of Training Centre

Training center is divided into four sections,

1. Turning section,

2. Fitting section,

3. Milling section,

4. Tractor training section.

3.2 Turning Section

In turning section, we have learnt about the lathe machine which is mother of

all machines and play a basic role in mechanical line.

3.2.1 Lathe Machine

Lathe is probably the oldest machine tools. The basic idea about turning or

lathe machine came out in 17 century. Until 1770, lathes were useless metal cutting

because they lacked power and holding device, were not strong enough and accurate

enough to guide the tools. For its development to the form in which we know it now,

we owe much to Henry Muldsley, who developed the sliding carriage and in 1880

built a screw cutting lathe.

3.2.2 Classification of Lathe Machine

1. Engine Lathe,

2. Speed Lathe,

3. Turret Lathe,

4. Toll Room Lathe,

5. Hollow Spindle Lathe,

6. Capstan Lathe,

7. Bench Lathe.

Lathe is also called Complete Machine. This single machine can do number of

operation.

3.2.3 Facing

This operation is carried out to produce flat surface at the end of part, which is

useful for parts that are attached to other components, or face grooving to produce

grooves for O-ring seals.

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3.2.4 Drilling

In this process a drilling of desire diameter is held in the tail stock and the

operation of drill is carried out.

3.2.5 Boring

In this enlargement of hole or cylinder cavity made by previous process is

done. It improves accuracy and surface finish.

3.2.6 Threading

In this operation internal and external threads on the surface are prepared.

3.2.7 Knurling

In this operation a regularly shaped roughness is prepared on the cylindrical

surface for fascinating easy gripping.

3.3 Fitting Section

Fitting work is very important work in engineering. In fitting shop unwanted

material is removed with the help of hand tools. It is done for mating, repair and

manufacturing purpose. The person working in fitting shop is called as fitter.

Commonly used tools are hacksaw, files, chisels etc.

3.3.1 Tools Used in Fitting Shop

1. Clamping Tools

2. Measuring and Marking Tools

3. Cutting Tools

4. Striking Tools

5. Drilling Tools

3.4 Milling Section

Milling machine were basically developed to machine flat surface. But, the

present machine can machine flat, countered and helical surfaces, cut gears and do

various other jobs. Due to this all milling machine is one of the most useful and

necessary machine tools found in the shop and it rank next to the lathe in importance.

Milling machine are designed to hold and rotate milling cutter or cutters, hold

the work piece and feed the work piece to the milling cutter in one several directions.

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IV. FOUNDRY MECHANISMS

Since there are certain basic steps in the metal casting process, these may be

used as unit of mechanism.

Processing steps which lead them to the mechanism are,

1. Sand preparation,

2. Core making,

3. Moulding, pouring and shakeouts,

4. Melting,

5. Cleaning.

Foundry is divided into following section,

1. Sand plant system,

2. Sand handling system,

3. Core making and baking system,

4. Moulding making and handling,

5. Core setting system,

6. Melting system,

7. Metal pouring system,

8. Testing lab,

9. Fettling section,

10. Painting and printing section.

4.1 Sand plant system

The main objective of it is to reuse the used lad to the installation of sand plant

system. The vital task of sand plant system is to deliver well prepared sand at required

place that will determine the efficient working of the foundry. After casing are

knocked out of moulding box on a vibratory shakeout box that the used sand is

returned to the fixed amount of new sand, binders, catalysts and hardeners to get to

the required composition of the sand. Green sand, dry sand and oil sand are being

prepared in the sand plant. These constitutes are added in Muller in which all contents

are mixed thoroughly and then supplied via belt conveyor system to working stations.

Green sand composition:

Muller batch capacity 700 kg

New sand 35 kg (5%)

Bentonite 660 kg (94.4%)

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Water 3.6 kg (0.4 %)

Return sand 1.4 kg (0.2%)

Dry sand composition:

Return sand 80%

New sand 10%

Bentonite 1.2%

Dextrin 1.8%

Moisture 7%

Composition of oil sand (100 kg of sand):

Bentonite 12 kg

Dextrin 25 kg

Linseed oil 15 kg

Moisture 20 G

4.2 Sand handling system

For handling the sand i. e. move it from one place to another, the bucket

elevator and belt conveyor are used.

4.2.1 Bucket elevator

When sand is to be conveyed vertically upward, a bucket is ideal. There are

two pulleys, one at the top and other at the bottom which carry an endless belt. The

belt carries number of buckets all around and the whole assembly is enclosed in steel

casting which has two openings, one at bottom for feeding and other at top for

discharge.

4.2.2 Belt conveyor

It is used for transferring sand from one place to another. It consist of endless

belt, two pulleys or idlers for carrying a loaded belt and returning the empty belt, a

belt tightening mechanism and the belt cleaner. The angle of inclination should not be

exceeding 150 for dry sand.

4.3 Core making and baking system

As patterns are made to get to outer shape of the casting, the inner shapes are

used to for whole generation core placed in the moulds. As the core comes in contact

of molten metal that must possess following characteristics:

1. Core sand must have high strength to bear the pressure of metal when poured.

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2. The sand must have high refractory characteristics so that it may not fuse due

to high temperature being in contact with molten metal.

3. It must have high cohesive property so as to get good finish castings.

Zircon paint (alcohol base) dried just by lightning it up. Large and heavy cores

are baked along with the dry sand moulds in oven.

Core drying cycles for oven:

3000 C – 1 hrs.

2000 C - 2 hrs.

Cooling time in oven 3 hrs.

After baking, the hardness is tested by using hardness meter

4.4 Mould making section

Moulds are being made on moulding machine pedantically powered rammers.

Metallic patterns are being used. After mould being made on moulding machine, it

goes to sand cutter which removes extra sand present and level the mould base, from

on to the power operated roller conveyor, the mould is handled using the swing type

crane. Core setting is done in drag part of mould. Zircon painting is sprayed on to the

mould (as paint is alcohol based hence get dry up by lighting fire).

4.4.1 Mould baking

Dry sand moulds are to bake to acquire hardness to with sand the pressure

produced by the flow of molten metal. These are baked in ovens. Mould baking cycles

for ovens 300C for 2 hrs. and Cooling time in oven 3 hrs.

4.4.2 Melting section

It is having two types of furnace.

1. Electric induction furnace,

2. Copula furnace.

4.5 Fettling

After they are knocked out on vibrator shake, the casting head to be finished

by the removal of projections whether they are gets riser or runner that where there as

a part of design aspect or the projection which has appeared as a defect like fins or

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blow holes. The process that involves all these procedure of casting finish is termed as

fettling.

Fettling operation is divided into following stages:

1. Knocking out of dry sand cores,

2. Removal of gates and risers,

3. Extraction of fins and other projections,

4. Cleaning and smoothing of the surface,

5. Repair casting by filling of the blow holes, straightening the wrap or deformed

casting.

4.6 Priming and painting

After all the cleaning process has been performed then the final step is priming

and the painting casting. The machine tool castings are generally big and are handled

with crane during painting. Painting is done by brushes only.

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V. HEAY MACHINE SHOP

5.1 Introduction

In heavy machine shop all the heavy part of tractor are machined like gear box

housing, Main transmission housing, Front cover etc. all the parts undergoes different

operations like milling, boring, drilling, tapping, slotting etc. in HMS section.

The entire machines in this section are special purpose machine; it means the

machine doing special or specific operation on a job.

The advantage of special purpose machine is that it increases the rate of

production. The machines are capable of machining any number of identical parts in a

very less time.

5.2 Parts Machined in HMS

1. Gear box housing

2. Main transmission housing

5.2.1 Gear Box Housing

Gear box housing is used for fitment of gears and shafts. The material used for

Gear box housing is cast iron.

5.2.1.1 Process of Gear Box Housing

Sr. no. Operation

1. Marking the gear box housing

With help of crane, we put the housing on the surface plate and after this

with the help of vernier height gigue we mark the gear box housing.

Marking is done of the gearbox is done for remove the all allowances

material.

2. Bottom Milling

With help of crane we put the work piece on the milling machine (SPM).

Bottom milling is done for removing the extra material on the gear box

housing.

3. Drill the location hole on the gear box housing. Location holes are made

for fix the housing on the different machine.

4. Top Milling

Put the housing on milling machine according to location holes. Top

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milling done for removing the extra material on the housing.

5. Front and Rear Cover

According to their location of hole we fix the work piece on the milling

machine. For removing the all allowance on to the housing.

6. Left And Right Milling

For removing the all allowance on to the housing.

7. Slot milling

In this milling we made the slots for gear forks which used for change the

gears. Dimension of slot is 16mm.

8. Boring

Boring is done for removing extra material from bores to make the bore

according to their dimensions.

9. Pre Boring of Steering Bore

Pre boring is done for removing the allowance from steering bore.

10. Heavy Duty Drilling

It is done for making the drilling in to the housing for joining purpose.

11. Bottom Milling Housing

20 drills simultaneous.

12. Tapping

Tapping is for making the internal thread in to the drilled holes and for

joining purpose.

13. Drill for Clutch and Pedal

For joining the clutch and pedal drilling is done on both faces right and

left on the gear box housing.

14. Final bores on the all bores i. e. steering bore, reverse gear and shaft

boring on the boring machine.

15. Washing for the gear box housing in the washing machine.

16. Inspection of the Gear box housing according to design.

5.2.2 Main Transmission Housing

Main Transmission Housing is manufacturing in heavy machine shop. M.T.

Housing is used for setup the differential and axle assembly. Material used for M.T

Housing is cast iron.

5.2.2.1 Manufacturing procedure of M.T Housing

Sr. no. Operations

1. Marking M.T Housing

With help of crane we put the housing on the surface plate and after this

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with the help of vernier height gauge we mark the M.T. Housing according

to their dimension. White paint is used foe marking.

2. Horizontal Milling.

Horizontal milling is done for removing the extra material or allowances

according to their drawing

3. Radial Drilling

Radial drills are used for the made the location holes in the housing and

these locations are used for seat the job on the different type of machine.

4. Milling of M.T. Housing

In this operation milling of four faces is done front, rear, left and right. In

operation we fix the job on their location and holes and after we do milling

5. Boring

In this boring operation we do rough boring of front, left & right bores.

6. Dimensions of bores:

Left hand bore: 290mm.

Right hand bore: 288& front hand bore: 90mm

7. Horizontal milling on front:

Horizontal milling is done for remove the extra material or allowances

according to their drawing. Horizontal milling is done on SPM milling

machine.

8. Boring finish

After horizontal milling we put the housing on the boring machine on their

location holes. it is done for finishing purpose.

9. Washing

Washing is done to remove chips and oil. this is done after all the

operation.

10 Inspection

Inspection of work piece according to their drawing.

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VI. LIGHT MACHINE SHOP

6.1 Introduction

As the name suggests that in this section light parts or small parts of tractors

are machined such as speed gears of tractor, sun & planet gears crown wheel, PTO

shaft, clutch shaft, spline shaft, front and rear axle.

6.2 Spline shaft

A shaft with longitudinal gear like ridges along its interior or exterior surface

is called spline shaft. the function of spline shaft is to transmit the power from

flywheel to lay shaft. Material used for spline shaft is low carbon steel.

6.2.1 Process for spline shaft

1. Raw material from vendors.

2. Cutting of shaft.

3. Facing and centering.

4. CNC turning.

5. Inspection

6. Gear hobbing.

7. Gear tooth rounding.

8. Fitting.

9. Washing.

10. Inspection.

11. Gear shaving.

12. Bench drilling.

After these process spline shaft send to heat treatment plant for hardening

process.

1. Gas carburizing & hardening.

2. Tempering

3. Shot blasting.

4. Straightening.

5. Centre grinding.

6. Internal grinding.

7. Fitting.

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8. Inspection

6.3 Bevel Pinion Shaft

Bevel pinion shaft is used for transmit the power from gear box to differential.

The material used for it is low carbon steel.

6.3.1 Process for Bevel Pinion Shaft

1. Raw material from vender.

2. Material cutting.

3. Facing and centering

4. Turning on s-pilot machine.

5. Inspection according to drawing.

6. Gear hobbing.

7. Fitting.

8. Washing and inspection work piece.

9. Gas carburizing & hardening.

10. Annealing.

11. Turning.

12. Cylindrical grinding.

13. Thread rolling.

14. Drilling.

15. Tempering.

16. Shot blasting.

17. Straightening.

18. Washing & inspection of the bevel pinion shaft.

6.4 Wheel Shaft

Wheel shaft is assembled in axle housing and its transmit torque to wheels.

6.4.1 Process for Wheel Shaft

1. Raw material from vender.

2. Facing and centering on lathe machine.

3. Drilling.

4. Radial drilling.

5. Gear hobbing.


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7. Induction hardening.

8. Tempering.

9. Cylindrical grinding.

10. Threading.

11. Fitting.

12. Horizontal milling.

13. Fitting


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VII. HEAT TREATMENT

All components (manufactured in LMS) after undergoing machining operation

are subjected to heat treatment. It is done so as to improve hardness and strength of

these components viz. gears and shafts.

Basic operations performed during heat treatment:

1. Hardening,

2. Quenching,

3. Annealing,

4. Tempering,

5. Normalizing,

6. Carburizing.

Melting temprature: 6400C,

Carburizing media 13- 15 % sodium cyanide + 85 % BaCl + NaCl

7.1 Hardening

For medium carbon steel and high carbon steel 8400C- 8500C

For other 770 – 8200C

Hardening is performed on the various metals and its alloys to provide them

with strength and wear resistance. It is accomplished by heating the component above

its hardening temperature and quenching it in water.

7.2 Quenching

Emercing hot metal in desired water or oil does quenching. Here transfer of

heat is ensured at slow rate so as to remove internal stresses to permissible limit.

7.3 Normalizing

In this process, iron alloy casting is heated to 50 – 600C above critical

temperature range. The casting is held for definite time and then allowed to cool in

still air. Normalization eliminates casting or cooling strains and resultant casting is

easy to machine.

7.4 Carburizing

Process of adding carbon to surface layer of the component is called

carburizing. It is the process of casehardening, which is addition of some elements

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like carbon, nitrogen to the surface by diffusion for surrounding medium at high

temperature the purpose of carburizing is to obtain high surface wear resistance and

obtain a hard surface.

7.5 Tempering

For medium carbon steel and high carbon steel 6700 - 6800 C

for fasteners tempering to be done at 3500 – 4000 C for 1 – 2 hrs.

In tempering long grains formed during quenching are broken into smaller

grains so as to improve elasticity of the material. Here heating is done at around 1800 -

2000 C for around 2 hrs. and then cool in air. It reduces internal stress and stabilizes

the structure of metal.

7.6 Annealing

For medium carbon steel and high carbon steel 6800 – 6900 C.

7.7 Case hardening

Carburizing + hardening.

7.7.1 Process used for blackening

1. Job is clean with cotton waste.

2. Put the job in the NaOH solution for 10 to 20 min. for de-greasing or

decomposition.

3. Wash it with warm water.

4. De-rust the job in the rust solution.

5. Wash it with water.

6. Shift it to blackening furnace at 1200 C for 10 – 20 min. according to sectional

area

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VIII. ENGINE ASSEMBLY AND TESTING

The engines of different models are assembled and tested in this shop as per

standard procedures.

8.1 Engine Assembly

In this shop, whole of the engine is completed and ready for the tractor

assembly. The various parts of engine from manufacturing section are brought in this

section and they are assembled to prepare the whole engine. The engine assembly can

be divided into following steps.

1. Washing of crank case with a special soap solution and drying it by means of

air jets.

2. Fitting of cylinder sleeve.

3. Fixing of studs and fitment of crank shaft in crank case.

4. Inserting pistons in cylinder sleeve.

5. Assembling the lubrication pump and fitment of cam shaft.

6. Mounting of flywheel with clutch assembly.

7. Fixing of cylinder head on the top of the cylinder sleeve.

8. Putting tappets, push rods and rocker arm for opening and closing the valves.

9. Attaching the fuel filters and oil filter.

10. Mounting the fuel injection pump and injection lines.

11. Fitting the self starter and alternator.

Now the engine is ready for testing. Among the all parts fuel injection system

is the heart of the engine.

8.1.1 Function of Injection Pump

The purpose of injection pump is the ensure injection of the flue at high

pressure in to cylinder space at certain instance and in correct amount. In gallery of

injection pump there are fitted in operates. The injection pump is driven from the

timing gear with shaft of injection pump to which it is connected with dog clutch. The

cams of the camshaft causes movement of plunger in their barrels by mean of roller

tappet to which plunger to is pressed with which rest at the lower spring late. The

barrels are secured against turning with pins roller tappet are secured with tannens of

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roller which mesh with the grooves of pump body. Rollers which contact the camps

are fitted on pins. In the recesses of top part of roller tappets adjusting screw with nuts

are fitted by mean which the angular distribution of injection start of individual

plunger can be adjusted. The working space of barrel are closed with delivery valve

the tappers of which are pressed in to the valve bodies by means of spring with peg.

The delivery valve are tightened to the cylinder head with the cylinder neck

thread union to which the injection line is fixed connection the injection pump to

injector. The deliver amount of fuel is changed by turning plunger i. e. by length over

lapping the transverse intake orifice in barrel. The plunger is provide in its bottom

part with a plunger vane which mesh with recess of control sleeve. The control sleeve

gear with the teeth is mounted on the top part of control sleeve the teeth engaging into

gearing of common control rack. The sleeve is tightened to the control sleeve by a

screw. When the shifting the control rack plunger are turned their barrel and helix

formed on the plunger opens sooner or later the transverse (intake) orifice in the

barrel. In the plunger has been turned in such way that the transfer groove connection

the face of the plunger with the helix edge flushes with transverse orifice in the barrel.

The pump does not deliver any fuel and control rack is in its stop position. If the

control rack is in its opposite position he pump deliver the maximum amount of fuel.

At the side fuel gallery into intake parts a relief valve is mounted which maintains a

constant pressure of 1 kg/cm2 on the intake port and the excessive amount of fuel is

returned by this valve back to the tank. When starting the engine, by making the use

of excess fuel, starting spring is fitted in governor which returns the control rack is

obtained for the purpose of maximum delivery of fuel at maximum injection delay. At

the opposite side of drive, the output governor is mounted which serves for regulating

the engine output at higher performance revolutions. The range of governing is given

by variable speed of engine.

The governor controls the amount of injected fuel into the engine, with set up

revolutions, in accordance with the taken of power. Decrease or increase of

revolutions at a higher or lower load of engine is called unevenness of output

governor. If the governing spring is set up from operator place to certain revolutions,

the governor shift the link member of pump into such position which at a certain

instantaneous load of engine corresponds to these selected revolutions.

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Terminology Connected with Engine Power

1. Bore: Bore is the diameter of the engine cylinder.

2. Stroke: It is the linear distance traveled by the piston from top dead center to

bottom dead center.

3. Stroke bore ratio: the ratio of length of stroke and diameter of bore of the

cylinder is called stroke bore ratio this ratio vary between 1

to1.45 and for tractor engine and this ratio is about 1.25.

4. Swept volume: It is the volume (A × L) displaced by one stroke of the piston.

Where A is the cross sectional area of the piston and L is the

length of stroke.

5. Compression ratio: it is the ratio of the volume of the charge at beginning of

the compression stroke to that at the end of compression stroke

that’s mean ratio of total cylinder volume to clearance volume.

6. Power: It is the rate of doing work. It is expressed in watt in SI unit.

7. Indicated power: it is the power generated in the engine cylinder and received

by the piston. It is the power developed in the cylinder without

friction or auxiliary unit.

8. Break power: It is the powered delivered by the engine and is available at end

of the crankshaft.

9. Belt power: It is the power of the engine measured at the end of a suitable belt

receiving drive from the PTO shaft.

10. Drawbar power: It is the power of a tractor, measured at the end of the

drawbar. It is the power, which is available for pulling loads at

the drawbar.

11. Power take off power: it is the power delivered by a tractor through its PTO

shaft.

12. Frictional power: It is the power required to the engine at a given speed

without producing any useful power. It represents the friction

and pumping losses of an engine.

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13. Mean effective pressure: it is the average pressure during the power stroke

minus the average pressure during other strokes. This pressure

actually forces the piston down during the power stroke.

14. Volumetric efficiency: It is the ratio of actual weight of air introduced by the

engine on the suction stroke to the theoretical weight of air that

should have been introduced by filling the piston displacement

volume with air at atm. Pressure and temp.

15. Torque: A turning effect due to force applied on some point is called torque.

16. Specific fuel consumption: It is the quantity of fuel consumed per kW-hr. in an

engine.

17. Brake mean effective pressure: It is the average pressure acting throughout the

entire power strokes, which are necessary to produce brake

power of the engine.

18. Mechanical efficiency: It is the ratio of brake power to indicated power.

19. Thermal efficiency: It is the ratio of output in the form of useful mechanical

power to the power value of the fuel consumed.

Engine components

Internal combustion engine consists of number of parts which are given as below

1. Cylinder: It is part of the engine which confines of the expanding gases and

forms the combustion space. It provides space in which piston operates to suck

the air or air fuel mixture. Cylinders are usually made of high grade cast iron.

2. Cylinder block: It is the solid casting which includes the cylinder and water

jackets.

3. Cylinder head: It is detachable portion of an engine which covers the cylinder

and includes the combustion chamber, spark plug and valves.

4. Cylinder liner or sleeve:

26

It is cylindrical lining either wet or dry which is inserted in the cylinder

block in which the piston slides. Cylinder liners are fitted in the cylinder bore

and they are easily replaceable. The overhauling and repairing of the engines,

fitted with liners is easy and economical. Liners are classified as

a. Dry liner and

b. Wet liner

A) Dry liners make meal to metal contact with the cylinder block casting.

B) Wet liners are come in contact with the cooling water, where as dry liners do

not come in contact with the cooling water

5. Piston: it is cylinder part closed at one end which maintains a close sliding fit

in the engine cylinder. It is connected to the connecting rod by a piston pin.

The force of the expanding gases against the closed end of the piston , forces

the piston down in the cylinder. This causes the connecting rod to rotate the

crankshaft. Aluminum and its alloy are preferred to made piston.

Head (Crown) of piston: it is the top of the piston.

Skirt: it is that portion of the piston below the piston pin which is designed to

absorb the side movements of the piston.

6. Piston rings: it is split expansion ring, placed in the groove of the piston. They

are usually made of cast iron or pressed steel alloy. the functions of the rings

are :

A) It forms a gas tight combustion chamber for all positions of piston.

B) It reduces contact area between cylinder wall and piston wall for preventing

friction losses and excessive wear.

C) It controls the cylinder lubrication.

D) It transmits the heat away from the piston to the cylinder wall.

Piston rings are of two types;

A) Compression ring and

B) Oil ring

7. Piston pin: it is also called wrist pin or gudgeon pin . it is used to join the

connecting rods to the piston.. it provides a flexible or hinge like connection

between the piston and the connecting rod. It is usually made of case hardened

alloy steel.

8. Connecting rod: it is special type of rod. One end of which is connected to

piston and the other to the crankshaft. It transmits the power of combustion to

27

the crankshaft and makes it rotate continuously. It is usually made of drop

forged steel.

9. Crankshaft:

It is the main shaft of an engine which converts the reciprocating

motion of the piston in to rotary motion of the flywheel. Usually the

crankshaft made of drop forged steel or cast steel. Crankshaft is provided with

counter weights throughout its length to have counter balance of the unit.

10. Flywheel: Fly wheel is made of cast iron. It stores energy during power stroke

and returns back the same energy during the idle strokes .engine timing marks

are usually stamped on the flywheel which helps in the adjusting the timing of

engine.

11. Crankcase: the crankcase is that part of the engine supports and encloses the

crankshaft and camshaft: it provides the reservoir for the lubricating oil of the

engine. It also serves as a mounting unit for such accessories as the oil pump ,

oil filter, generator, starting motor and ignition components.

12. Camshaft:

It is shaft that raises and lowers the inlet and exhaust valves at proper

time. The speed of the camshaft is exactly half the speed of crankshaft in four

stroke engine. It is mounted in the crankcase parallel to the crankshaft.

28

13. Timing gear: timing is a combination of gears one gear of which mounted at

one end of camshaft and other gear on the end of crankshaft. Timing gear

controls the timing of ignition, timing of opening and closing of valves as well

as fuel injection timing.

14. Inlet manifold: it is that part of engine through which air or air fuel mixture

enters into the engine cylinder. It is fitted by the side of the cylinder head.

15. Exhaust manifold: it is that part of engine through which exhaust gases go out

from engine cylinder. It is fitted by the side of the cylinder head.

8.2 Engine testing

After assembly, engine is brought to engine testing section. In this section,

practical checking of engine is done on engine. Firstly the water supply is given to the

engine and then started it with external DC supply. During running the engine, the

load is varied and various terms are checked such as lubricating oil pressure, load

capacity, fuel consumption, torque, operating temperature, etc. Then proper operating

of valves is checked.

8.2.1 Procedure for Engine Testing

1. Note starting time of engine and also bed no. which it is being tested.

2. Check oil level of engine and FIP.

3. Check clearance of valve tappets for inlet and exhaust.

4. Check oil pressure at idle and rated rpm.

5. Check any unusual sound.

6. Check idle and fly up rpm.

7. Check leakage of water, fuel and oil at rated rpm.

8. Check load and torque at rated rpm, fuel timing in seconds for 100cc and

recheck oil pressure.

9. Check outlet water temp.

10. Check leakage in front and rear oil seal.

11. Check visible blow hole in component, if any.

12. Pix OK sticker.

13. Check engine no. punched on engine. It is to be same as on sticker.

The engine is kept running for 2 hours. For proper working, load capacity is

checked by applying load on the shaft of engine through water. The lubricating oil

29

pressure in the engine should be 3.8 to 4.2 Kg/ cm2. The maximum RPM of the engine

are kept 2200. Supplying a measured quantity of fuel, the fuel consumption is

checked. For this test, 100 cc (cm3) fuel is supplied to the engine.

Corr. Power =

Where, C. F. =

P= atm. Press. (mm of Hg )

T= ambient temp. (0c)

Corr. SFC. =

Volume of fuel is 100cc or 200cc and fuel time is in sec.

8.2.2 Engine testing cycle time

Running time (min) RPM Load, l

10 700 Nil

20 1000 20

30 1400 50

30 1700 75

10 1600 75

5 1800 100

5 Rated 2100/2200 100

8.3 Specifications of HMT Tractors

8.3.1 Model 2522

30

Sr. no. Particulars Specifications

1. Bore × Stroke (mm) 95 × 110

2. Engine rated speed (rpm) 2100

3. Engine fly up rpm 2300 + 60

4. Static injection timing (0 BTDC) 14

5. Tappet clearance -

Inlet valve (mm) 0.3

Exhaust valve (mm) 0.4

6. Height of cylinder liner above

cylinder block (mm)

0.06 - 0.12

7. Bumping clearance (mm) 0.75 + 0.4

8. Injection tip (mm) 2.2 – 2.5

9. Injection pressure (bar) 190 + 8

10. Piston ring end gap (mm) -

First ring 0.2 – 0.4

Second ring 0.4 – 0.6

Third ring 0.25 - 0.5

11. Nozzle spray holes 5 × 0.2 × 150

12. H. P. pipe size (mm) 6 × 1.8 × 500

13. Ring colour on injector Utility green

8.3.2 Model 3022

31


1. Bore × Stroke (mm) 102 × 110







6. Height of cylinder liner above cylinder block (mm) 0.02 - 0.06

7. Bumping clearance (mm) 0.7 - 0.966

8. Injection tip (mm) 3.18







12. H. P. pipe size (mm) 6 × 1.5 × 400

13. Ring colour on injector Golden yellow

8.3.3 Model 3522





32














12. H. P. pipe size (mm) 6 × 1.5 × 500


8.3.4 Model 4022







33












12. H. P. pipe size (mm) 6 × 1.5 × 500


8.3.4 Model 4922


1. Bore × Stroke (mm) 102 × 110








34









12. H. P. pipe size (mm) 6 × 1.5 ×450


8.3.5 Model 6522


1. Bore × Stroke (mm) 102 × 110










35







12. H. P. pipe size (mm) 6 × 1.5 ×450


IX. TRACTOR ASSEMBLY SHOP

INTRODUCTION:-

In this shop, whole of the tractor is assembled and completed for testing and

displacement various components of tractors are manufacture in light machine shop

and heavy machine shop. Engine from engine assembly, lift from lift assembly and

other component from LMS, HMS are made to assemble here

Tractor Assembly Procedure:-

9.1 Gear Box Sub Assembly:-

First gear box housing is put on the trolley and different type of the shaft and the gear

assemble in the gear box.

9.2 Clutch Assembly:-

Clutch is device used to connect and disconnect the tractor engine from the

transmission gears and the drive wheels. Clutch transmits power by mean of friction

between driving members and driven members. Generally dual clutch is used in the

HMT Tractors.

9.3 MT Housing Assembly:-

In this housing the differential unit and the hydraulic pump is fitted also it provide the

special arrangement of gears.

36

9.4 Rear Axle Mounting:-

Mount brake shoes, brake shoes holder, expander unit, retractor spring wheel shaft

along with flange, tapered roller bearing, a bull gear along with spring and locked

device to prevent axial movement off bull gear, on the porter housing.

Assemble rear axle housing on the portal and then assemble the crown on the

differential shaft around the brake shoes.

9.5 Lift Mounting:-

After mounting of axle on the differential lift is mounted on the main transmission

housing which is used for the load up to 1200 kg and 1400 kg.

9.6 Engine Mounting:-

After then engine is mounted on gear box and MT housing and portal assembly with

the help of bolts.

9.7 Front Axle Mounting:-

Assembly front axle wheel hub, pivot, king pin, track record on the extension along

with locking devices, bush and bearings.

Connect these two extensions with each other by the extension tube.

9.8 Steering Assembly:-

Steering:- the system governing the angular movement of front wheel of tractor is

called steering system. This system minimizes the efforts of the operator in turning

the front wheel with the application of leverages.

9.9 Brake System Assembly:-

Brake is used to stop or slow down the motion of tractor. It is mounted on the driving

axle and operated by two independent pedals. Each pedal can be operated

independently to assist the turning of tractor during the field work or locked together

by means of a lock.

9.10 Washing Zone, Drying Oven and Painting:-

After mounting all the parts on the body it sends to washing zone for remove the

unwanted material like dust and machining material.

After washing of the body, it sends to oven for drying the body where we dry

it. After drying the body painting is done on the body. Grey paint is used for painting

the body and the chassis.

37

9.11 Greasing Zone

Greasing is done all the greasing points with the help of pneumatic gun.

The following are the grease points:

1. Front wheel hub

2. Front axle extension

3. Front axle pin

4. Clutch shaft

5. Right hand stud

6. Three point linkage

7. Tie rod end

Three free play of foot brake is maintained 2mm.

9.12 Air Cleaner, Radiator and Fuel Tank

After washing and painting air cleaner and radiator mount on the tractor body.

Heavy duty type of air cleaner is used in the tractors.

This is of oil bath type cleaner. It consists of a filter element saturated with oil.

At the bottom there is separate oil pun. The air from atmosphere enter in to the gap

and when air takes turn it leaves the impurities there and after it impinging on the

surface of oil and leaves the impurities there and at last air pass through the filter and

cleaning of air is done.

9.13 Air Cleaner

After fitting the air cleaner radiator is attached with engine. The main purpose

of radiator is providing the cooling to the engine i.e. the remove the heat from engine.

Water and alcohol is used as coolant in the radiator.

9.14 Tyre Mounting

After attached all parts tyre is attached with tractors. After assembly the tyre

alignment of wheel is done.

9.15 Following electrical items are mounted,

1. Horn

2. Head Light

3. Brake Light

4. Parking Light

5. Plough Lamp

6. Direction Indicators

7. Dashboard pilot lamp.

38

After this, tractor is completed up to bridge out stage

SECTION B

PROJECT WORK

Objectives:

1.Study and documentation of stage wise assembly procedures in assembling

tractors of different models

.

2.Time and work force requirement study for assembling 1800 units of 2522, 3600

unit of 3522, 1800 unit of 4022, 900 unit of 5022, 900 unit of 6522 totaling 9000

unit per annually.

.

3.Action required to be taken for increasing productivity and reduce in rework /

rejection at final / different stages.

39

TRACTOR ASSEMBLY

Introduction

. All the tractors 2522, 3522, 4022, 4522, 5022 and 6522 are assembled here.

Tractor Assembly Procedure

The detailed procedure of tractor assembly is given below.

Gear Box Sub Assembly

First gear box housing is put on the trolley and different type of the shaft and

gear assembled in the gear box.

Following parts are assembled in the gear box housing:

1. Lay shaft.

2. Reverse gear.

3. Reduction shaft.

4. Clutch.

5. Bended gear.

6. Front cover.

7. PTO Spline.

In HMT tractors sliding mesh type gear box is used. It contains

40

1. Splined shaft.

2. Lay shaft.

3. Speed gears.

4. Reduction gears.

5. PTO shaft.

6. Clutch shaft.

7. Clutch.

8. Bended gear.

i. Main drive gear

ii. Counter shaft

iii. Main shaft

iv. I gear

v. II gear

vi. III gear

vii. Top speed engaging dogs

INPUT SHAFT ASSEMBLY:

Input shaft consist of spiral gear on one end splines on the other end.

Splined part is attached to the clutch and geared part (Z-19) is attachéd the constant

mesh gear of lay shaft i. e. Z-45. Input is put in to the gearbox with the bearing, which

is locked by circlip.

MAIN SHAFT ASSEMBLY:

Main shaft assembly is solid shaft with splines on outer surface. The shaft

is placed in to gearbox with both end supporter by bearing and locked by circlip. The

back part of shaft is projected outside the gearbox to get drive from it. The assembly

of shaft consist of gears 24, 31 and 34 gear. The sliding gear 34 is used for first and

reverse gear, sliding gear 31 is used for second gear and sliding gear 24 used for third

and fourth gear. These gears are provided with grooves on one side to attached gear

shifter fork.

Intermediate shaft assembly.

Output shaft assembly.

Lay shaft and connecting shaft assembly ( along with power

transmission gears).

41

LAY SHAFT ASSEMBLY:

The lay shaft is hollow shaft with spling on outer surface. The one end of

the lay shaft is threaded ( in case of single clutch) and tightened from front side of

gear box with a hexagonal nut. The whole assembly consist of gear Z-45 i. e.

( constant mesh gear with input shaft gear) spacer 15mm, gear 35, gear Z-29, spacer

30mm, gear Z-28, spacer 25mm bearing with circlip. The whole assembly is washed.

In case of dual clutch tractors model the drive shaft is placed through the hollow lay

shaft. The drive shaft consist of splines on one end and the gear (Z-52) on the other

end. The constantly meshed with the gear of intermediate shaft. The main function of

the lay shaft is to rotate fixed gear on it from where we can get different speed with

the help of sliding gear on drive shaft.

Clutch

In HMT, all the tractors have spring loaded dry friction type dual clutch

various parts of clutch are: pressure plate, clutch plate and spring. Release bearings

mounted on PTO shaft are always in contact with shaft when the clutch is pressed the

release bearing depress with release level with further produce tension in compression

springs and as a result of this the gap is produce between pressure plate and flywheel

and disc become free on pressing the clutch up to 7cm, the drive to clutch shaft is

stopped and when full clutch is pressed drive to PTO as well as clutch shaft is also

stopped. But in first position PTO rotates and wheels are in standstill position.

42

The main function of clutch is to engage or disengage the power coming from the

engine.

On the basis of working there are two type of clutches.

Single clutch

Double clutch

Genrally double clutch is used in HMT Tractor

DOUBLE CLUTCH:- This clutch is provided with two clutch plates one for the

main transmission & the other for P.T.O drive. In b/w the two clutch plates, an

intermediate plate is provided. Normally, six release levers the purpose of

disengaging the clutch plates Out of six three are for engine disengaging & the rest of

three are for disengaging the P.T.O drive.

MT Housing Assembly

It is the rear part of the tractor cheesy. The main function of the differential in

tractor to reduce final speed and also turn the drive around at 90 degree. The reduction

of the speed is done two stages. The first stage is reduction in tail pinion and crown

wheel meshing and second stage is reduction in bull gear meshing with left and right

B.P. shaft. Its also consisting the P.T.O. shaft, which is used to the threshers, pumps,

rotavator and other accessories components with the help of pully attached on it.

Following are main parts of differential housing:-

1. Crown wheel.

2. Bevel pinion.

3. Differential assembly. ( with sun and star gear)

4. P.T.O. shaft.

5. Bull gear.

6. Bevel gear.

7. Bearing.

8. Half shaft.

43

9. Brakes housing.

Differential: it is the a special arrangement of gears to permite one of the rear wheel

of the tractor to rotate slower or faster than the other. While turning the tractor on

curved path, the inner wheel has to travel lesser distance than the outer wheel.

The bevel pinion is in mesh with large bevel wheel known as crown wheel.

The main function of crown wheel is to transmit power through right angle drive to

suit the tractor wheel.

Assembling of different component in M.T. Housing.

1. Clean MT housing with dry air and cloth.

2. Mount hydraulic pump and link brackets on MT housing.

3. Assemble the differential kit on the MT housing. It consist of crown wheel, two sun

gears, four planet gears, two planet pins, left and right cages, taper bearing and tail

pinion with two roller bearing and flanges. Shims are used for maintaining proper

backlash between pinion and crown wheel.

4. Assemble hydraulic pump lift gear.

5. Assemble hand brakes in the MT housing and gear shifting rods with forks on the

gear box.

6. Assemble pump shaft and PTO shaft in MT housing and gear shifting rods with

fork for pump shaft.

7. Assemble top cover on gear box with reduction gear change lever, pump shaft

change lever hand brake, pin and plug etc.

Shim is provided to increase or decrease the distance of the bevel pinion shaft.

Shim Thickness and Backlash

Shim and thickness = P+Q+R+S

P= Reading of bevel pinion in sub assembly or the fixture it is always negative

with respect to the setting gauge block its nominal position valve must

always be taken account.

Q= Reading as given on MT housing, it gives the variation of the bevel pinion

mounting face from the two coaxial flange bores with respect to the

theoretical valves.

R= Reading as given on crown wheel. It gives the variation in the mounting

distance for smooth running as determined in the lapping machine.

44

S= Reading as given on the bevel pinion. It the thickness on the bevel pinion

from theoretical vales, it is always negative.

Backlash to be maintained for all models 0.25 to 0.27.

Portal and Direct Axle Mounting

Assemble differential shat with two roller bearings, wheel shaft along with

flange, tapered rolling bearing, a bull gear along with spring tube and locking device

to prevent axial movement of bull gear, on the portal housing.

Rear axle housing assembly

Mount brake shoes, brake shoes holder, expander unit, refractor springs on the

rear axle housing.

Assembly rear axle housing on the portal and then assembly the crown on the

differential shaft around the brake shoes.

1. Assembly this rear axle and portal assembly on the MT housing such that hand

brake shoes are on the brake drum.

2. Assembly brackets on the MT housing and portals and connect these by a

York.

3. Assembly the lift assembly on the MT housing.

4. Assembly brackets to mount master cylinder arrangement and differential lock

pedal. Then engagements on and make the linkage to connect these

arrangements to the respective systems.

5. Fill gear box housing and portal with lubricating oil and assembly the rear

cover on MT housing and portal.

6. Assembly tailor end coupling, channel hook, lower and upper linkages, hinges

on the rear of MT housing.

7. Assembly clutch linkage in the gear boxes. It consists of clutch pedal and

thrust bearing, release fork, fork lever, spring and adjusting nuts etc.

Lift Mounting

45

After mounting of axle on the differential lift is mounted on the main

transmission housing which is used for lift the load up to 1200kg and 1400kg. Drive is

given with the help of hydraulic pump which is set bottom of the MT housing. After

mounting left and right hand portals on the sides of differential housing, hydraulic lift

is mounted on the top of the differential housing hydraulic lift mainly consist of

kinematics systems that operates the distributor unit. The oil from the distributor unit.

Then, it follows two paths, inner circuit and outer circuit. The inner circuit is used for

lifting the plough as the putter circuit is used for trolley purpose for automatic loading

and unloading. The lift permits the simultaneous use of outer and inner circuit for

three positions, whereas;

P: Position control, D: Depth control and M: Mixed control.

Position control; in this system, constant depth of ploughing is maintained by

automatic adjustment of draft of tractor. In this system the control valves can be

operator directly by the driver to raise lower or hold an implement mounted on the

linkage at any chosen height.

Draft control: in this system the working depth of any implement can be controlled

continuously without the need for a depth wheel on the implement.

Mixed control: it is the combination of position control and draft control.

Oil is sent to ram cylinder for lifting the arms of the lift oil is entered in

distribution box and enters a gallery. From where oil goes to differential shaft through

binder valve and outer and inner valve at the same time from outer circuit valve, it

enters inner circuit gallery. Inner circuit gallery sends oil other gallery which has three

opening for Free circuit, Anti slip circuit and Lowering circuit.

46

Free circuit means, no work is being done and pump is working i. e throwing

oil with pressure. So free path circuit is provided to discharge oil and to protect the

pump from bursting.

Anti slip circuit is provided so that when the oil reaches the gallery having

differential bush, different quantity of oil is supplied for outer and inner circuit fort

lifting the arms of the lift. When the lift is lowered, the inner circuit valve changes its

position and allows the oil to go through lower circuit hole.

Engine Mounting

The tested ok engine after trial is send to the assembly shop, where it is

mounted on the gear box, and MT housing and portal assembly with the help of bolts.

Front Axle Mounting

1. Assembly front axle wheel hub, pivot, king pin, track record on the extension

along with locking devices, bush and bearings.

2. Connects these two connections with each other by the extension tube.

3. Assemble front axle bracket on the above arrangement with help of center pin.

4. Assemble all the parts with the tractor body.

Steering Assembly

Steering:- the system governing the angular movement of front wheel of tractor is

called steering system. This system minimizes the efforts of the operator in turning

the front wheel with the application of leverages.

Component of steering system:-

1. Steering wheel.

2. Steering shaft.

3. Steering gear.

4. Pitman arm ( drop arm).

5. Drag link.

6. Steering arm.

7. Tie rod.

8. King pin.

Steering is used in tractor is screw and nut type steering. After mounting all

the accessories, steering is assembled on gear box.

There are two types of steering system are used in HMT Tractors.

1. Mechanical steering system.

2. Power steering system.

47

Steering geometry:

Various angles in steering geometry are

1. Caster angle: it is the angle between the centre line of the king pin of the

vertical line

2. Camber angle: it is the angle between the center line of the tyre and vertical

line.

3. King pin inclination angle: it is the angle between the vehicle line and the

king pin centre line is known as king pin inclination angle.

4. Toe –in: it is the difference in the distance of the centre lines of the back end

and front end of front wheels of tractor.

5. Toe-out: toe-out is the spreading apart of the front wheels on turns. The

purpose of toe-out is to give correct turning alignment and to prevent

excessive tyre wear.

Brake assembly:-

This tractor having heavy duty self-energizing, water sealed disc with

spherical roller and ventilation pipe which gives better cooling. The ventilated results

in reduction of about 30% pad temperature. Brake housing cover containing two disc

made of asbestos base non-metallic. The max. temp. resistance about 300 degree C

between this two disc plate a cast iron plate is fixed which contain steel spherical

roller and hold by spring. Whenever brake is applied the spherical roller move are left

from there place in the plate and try to expanded the plate. During expanding of plate

the disc are strongly mounted on B.P left and B.P right shaft stop the speed of

differential. The also having actuators and link with rubber seal.

There are two types of brake system used in HMT Tractor.

1. Mechanical brake

2. Hydraulic brake

Hydraulic Brake and Floor Assembly

Hydraulic brake system is based on the principal of pascal’s law The brake

fluid which is usually a mixture of gylcerine and alchol is filled in the master

cylinder .when in the master cylinder is forced into the cylinder and the entire

system turns to a pressure system.Immediatly the piston of the wheel cylinder slides

outward which move the break shoes to stop the rotating drum. When the pedal is

released,the return spring of the a sudden pressure drop in the the line. The retracting

48

spring of the break shoe bring them back to their original position.Thus the piston of

the wheel cylinder returns back.

After assemble various accessories on the body Master cylinder and floor is

attached with body. Master cylinder is used for apply the force in the brake pads.

The basis component of hydraulic system.

Wheel cylinder

Maser cylinder

Piston rod

Retraction spring

Brake drum

Washing Zone, Drying Oven and Painting

After mounting all the parts on the body it sends to washing zone for remove

the unwanted material like dust and machining material.

After washing of the body, it sends to oven for drying the body where we dry

it. After drying the body painting is done on the body. Grey paint is used for painting

the body and the chassis.

Properties of paint

Base painting of chassis

Base hardness : 7:1

Viscosity : 20-24 sec.

Operating pressure : 5-6 Kgcm3

Thinner : 20-30%

Greasing zone

Greasing is done all the greasing points with the help of pneumatic gun.

The following are the grease points:

8. Front wheel hub

9. Front axle extension

10. Front axle pin

11. Clutch shaft

12. Right hand stud

13. Three point linkage

14. Tie rod end

Three free play of foot brake is maintained 2mm.

49

Air Cleaner, Radiator and Fuel Tank

After washing and painting air cleaner and radiator mount on the tractor body.

Heavy duty type of air cleaner is used in the tractors.

This is of oil bath type cleaner. It consists of a filter element saturated with oil.

At the bottom there is separate oil pun. The air from atmosphere enter in to the gap

and when air takes turn it leaves the impurities there and after it impinging on the

surface of oil and leaves the impurities there and at last air pass through the filter and

cleaning of air is done.

Air Cleaner

After fitting the air cleaner radiator is attached with engine. The main purpose

of radiator is providing the cooling to the engine i.e. the remove the heat from engine.

Water and alcohol is used as coolant in the radiator.

Tyre Mounting

After attached all parts tyre is attached with tractors. After assembly the tyre

alignment of wheel is done.

Alignment parameter

Toe in of wheel 4 mm i. e. from front distance is constant and from the back

side the distance is increased 4 mm. 2 to 3 deg. camber is given to wheel.

Purpose of alignment

1. It provides good balancing to the tractor.

2. It prevent from wear and tear of tyres.

3. It helps in steering system.

After this, bonnet and electrical items are attached to the tractors.

Following electrical items are mounted,

8. Horn

9. Head Light

10. Brake Light

11. Parking Light

12. Plough Lamp

13. Direction Indicators

14. Dashboard pilot lamp.

After this, tractor is completed up to bridge out stage.

TRACTOR TESTING

50

1. Sinking

2. Jerking

3. Drafting

4. Hand brake setting up to forth teeth.

5. Foot break to be checked combined and individually.

6. Different locks to be checked for its normal function at500-700RPM.

7. Tractor to be checked for any unusual sound from.

8. Road testing.

9. Roller testing.

Time and Work Force Requirement Study for Assembling Engine

Units of Different Models

Sr. no. Model Time required to

assemble one unit

(hr.)

No. of

units

Total time

required

(hr.)

Work force

requirement

1. 2522 7 1800 12600 1680

2. 3522 11 3600 39600 5280

3. 4022 11 1800 19800 2640

4. 5022 11 900 9900 1320

5. 6522 15 900 13500 1800

Total 9000 95400 12720

51

Suggestion for Quality Improvement of Tractor :

i. Feedback to defects in tractor to concerned department must be given

immediately to curb the faults at manufacturing level.

ii. Wash all the parts on the body in washing zone for remove the unwanted

material like dust and machining material.

iii. Total material distribution system on tractor assembly line (stage wise should

be handled totally by P. P. C. to avoid the wastage of time and wastage of

material).

iv. To avoid delays on assembly line, every component should be given after

complete inspection to tractor assembly line.

v. Tractor assembly store like G.B. housing, M.T. housing & shifting of engine

etc. should be properly handled by expert person concerned to avoid the

wastage of material and proper accounting automatically.

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HMT TRACTOR PROJET REPORT FOR SUMMER TRAINING

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