This document contains a summer training report submitted by Ravinder in partial fulfillment of a Bachelor of Technology degree in Mechanical Engineering. The report details Ravinder's 42-day summer internship at Lakshmi Precision Screws Ltd. in Rohtak, where he trained under the guidance of manager Vijay Kumar Jain. The report includes sections on the company, types of brakes, disc brakes, drum brakes, and provides technical details and images related to the Mahindra Bolero vehicle and its brake systems.

1. MAHINDRA& MAHINDRALtd.
DARBHANGA( BIHAR)
PROJECT ON BOLERO
(EX/SLX/SLE/ZLX )BRAKES
UDIT NARAYAN
14-ME-073
A summertraining report submitted In
Partial fulfillment of my Bachelor
B.TECH (MechanicalEngineering)
GANGA INSTIT-UTE OF TECHNOLOGY & MANAGEMENT
KABLANA , JHAJJAR
AFFILIATED TO
M.D. UNIVERSITY, ROHTAK
MAY 2009

2. PROJECT
ON
“LAKSHMI PRECISION SCREWS LTD. ROHTAK”
A SUMMER TRAINING PROJECTREPORT
Submitted by
RAVINDER
15-LME-109
In partial fulfillment for the award of the degree
of
BACHELOR OFTECHNOLOGY
in
MECHANICALENGINEERING
GANGA INSTITUTEOF TECHNOLOGY AND MANAGEMENT
KABLANA,JHAJJAR
AFFILIATED TO
M.D UNIVERSITY, ROHTAK

3. DECLARATION
This training program has been undertaken during the summer break 2016 as a
trainee by me after completion of my Second year under the guidance of my
mentor Mr. VIJAY KUMAR JAIN (MANAGER.) Further I would like to declare that
this project is my original work and has been prepared solely for academic
purpose. This project has not been presented in any seminar or submitted
elsewhere for the award of any degree or diploma.

4. Acknowledgement
I am Indeed I highly obliged MR. VIJAY KUMAR JAIN. “LAKSHMI
PRECISION SCREWS LTD. ROHTAK” for giving me this opportunity to this
summer internship project. I owe thanks to many people who helped and supported
me during the project. I am thankful to all other faculty members and admistrative
staff of GITAM, KABLANA, JHAJJAR FOR THERIR valuable help during
the project
Finally I am thankful to all the people who helped supported me directly or
indirectly in this project
Thank you
RAVINDER

5. Training Details
NAME: AQUIB JAWED
YEAR: 2016
ORGANIZATION: SHIV SHAKTI WAHAN Pvt. Ltd. DARBHANGA (
BIHAR)
PLACE OF TRAINING: N.H-57- NEAR DILLI MORE FLYOVER
BASUDEOPUR , DARBHANGA – 846004, TEL – 06272-246026, 247026
Email: info@shivshakti.biz
DESIGNATIONOF GUIDE:Mr. ASFAQUEALAM ( Head
TechnicalCell)
PERIOD: FROM- 20th June 2016 to 01st Aug 2016
DURATION: 42- DAYS.
FIELD OF TRAINING: PROJECTON MAHINDRABOLERO ( EX
/ SLX /SLE/ZLX ) BRAKES

6. TABLE OF CONTENTS
BONAFIDE CERTIFICATE…………………………………………..
DECLARATION……………………………………………………………...
ACKNOWLEDGEMENT……………………………………………………
TRAININGDETAIL…………………………………………………………
INTRODUCTIONOFCOMPONY…………………………………………..
1.MAHINDRABOLERO………………………………………………….......
1.1 BOLEROIMAGE-EX&SLE……………………………………….......
1.2 BOLEROIMAGE–SLX&ZLX………………………………………..
2. BRAKE…………………………………………………………..…
2.1 IMAGE OF BRAKE……………………………………………….....
2.2TYPES OF BRAKE……………………………………………...……
3. DISC BRAKE……………………………………………………........
3.1 CONTENT OF DISC BRAKE...........................................................
3.2 HISTORY.............................................................................................
3.3 BRAKE DISC…………………………………………………………
3.4 CERAMIC COMPOSITE……………………………………………
3.5 CALLIPERS…………………………………………………..………
3.6 BRAKE PAD…………………………………………………….……
4. DRUM BRAKE………………………………………………………
4.1 CONTENT OF DRUM BRAKE………………………………...….
4.2COMPONENTS……………………………………………………….
4.3BRAKE DRUM………………………………………………………..
4.4 BRAKE SHOE………………………………………………………...
4.5 DRUM BRAKE DESIGNS…………………………………..….….
4.6 ADVANTAGES…………………………………………………..…
4.7 TO LIST ADVANTAGES OF DRUM BRAKES……………....…..
4.8 DISADVANTAGES……………………………………………............

7. AUTOMOBILE INDUSTRY
The automobile industry has changed the way people live and
work. The earliest of modern cars was manufactured in the year 1895.
Shortly the firstappearanceof the car followed in India. As the century turned,
three carswereimported in Mumbai (India). Within decade there weretotal of
1025 cars in the city.
The dawn of automobile actually goes back to 4000 years when the firstwheel
was usedfor transportationinIndia. In thebeginning of 15th century,Portuguese
arrived in Chinaand the interaction of the two cultures led to a variety of new
technologies, including thecreation of a wheel that turned under its own
power. By 1600s small steam-poweredengine models was developed,
but it took another century before a full-sizedengine- poweredvehiclewas
created.Brothers Charles and Frank Duryea introduced the actual
horseless carriage in the year 1893. Itwas thefirst internal-combustion motor
car of America, and it was followed byHenry Ford’s firstexperimentalcar that
same year.Oneof the highest-rated early luxury automobiles was the 1909 Rolls-
Royce SilverGhostthatfeatured a quiet 6cylinder engine, leather interior, folding
windscreensand hood, and an aluminum body.Chauffeurs usually droveitand
emphasis was on comfortand stylerather than speed.During the 1920s, the
cars exhibited design refinements such as balloon tires, pressed-steel
wheels, and four-wheelbrake
Graham Paige DC Phaeton of 1929 featured an 8-cylinder engine and an aluminum
body.The 1937 Pontiac De Luxe sedan had roomy interior and rear-
hinged back door thatsuited more to the needs of families. In 1930s,
vehicles were less boxy and morestreamlined than their predecessorwas.
The 1940s saw features like automatic transmission, sealed-beam headlights, and
tubelesstires.
The year 1957 brought powerful high-performance cars suchas Mercedes-Benz
300SL. Itwas built on compactand stylized lines, and was capable of 230

8. kmph(144 mph).This was the Indian automobile history, and today modern
cars aregenerally light, aerodynamically shaped, and compact.
MAHINDRA BOLERO
Mahind ra Bo lero is o ne o f the mo s t s uc c es s ful and p o p ular
utility vehic le o f theMahindra and Mahindra Group. The car is robust in
appearance and it has been elegantlydesigned, keeping in mind the conditions of
the Indian roads.
Mahindra Bolero is also among the best fuel-efficient cars of India as the
manufacturer has equipped it with a 2500 cc diesel engine with5- speed
transmission

9. BRAKE:


A brake is a mechanical device
which inhibits motion.
WORKING OF BRAKES
•A COMMON MISCONCEPTIONABOUT BRAKES IS THAT BRAKES SQUEEZE
AGAINST A DRUM OR DISC, AND THE PRESSURE OF THE SQUEEZING
ACTION SLOWS THE VEHICLE DOWN. THIS IS IN FACT A PART OF THE
REASON FOR SLOWING DOWN A VEHICLE.
•ACTUALLY BRAKES USE FRICTION OF BRAKE SHOES AND DRUMS TO
CONVERT KINETIC ENERGY DEVELOPEDBY THE VEHICLE INTO HEAT
ENERGY.
•WHEN WE APPLY BRAKES, THE PADS OR SHOES THAT PRESS AGAINST
THE BRAKE DRUMS OR ROTOR CONVERT KINETIC ENERGY INTO THERMAL
ENERGY VIA FRICTION.

11. TYPES OF BRAKES

MECHANICAL BRAKES
•DRUM BRAKES
•DISC BRAKES
HYDRAULIC BRAKES
POWER BRAKES
•AIR BRAKES
•AIR HYDRAULIC BRAKES
•VACCUM BRAKES
•ELECTRIC BRAKES

12. DISC BRAKE
A disc brakeis a type of brakethat uses calipers to squeeze pairs ofpads againsta
disc in order to create friction that retards the rotationof a shaft, such as a vehicle
axle, either to reduce its rotational speed or to hold it stationary. The energy of
motion is converted into wasteheatwhich mustbe dispersed. Hydraulic disc
brakes are the mostcommonly used formof brakefor motor vehicles but the
principlesof a disc brakeare applicable to almost any rotating shaft.
Compared to drumbrakes, disc brakes offer better stoppingperformancebecause
the disc is more readily cooled. As aconsequencediscs are less prone to the brake
fade caused whenbrakecomponents overheat. Disc brakes also recover more
quicklyfromimmersion (wetbrakes are less effective than dry ones).
Most drumbrakedesigns have at least one leading shoe, which gives a servo-
effect. By contrast, a discbrakehas no self-servo effectand its braking forceis
always proportionalto the pressureplaced on the brakepad by the braking
systemvia any brakeservo, braking pedal, or lever. This tends to give the driver
better. "feel" and helps to avoid impending lockup. Drums arealso prone to "bell
mouthing" and trap worn liningmaterial within the assembly, both causes of
various braking problems.
CONTENTS OF DISC BRAKE
1 History
2 Brakedisc
2.1 Ceramic composites
3 Calipers
4 Brakepads

13. BRAKE DISC
The brake disc is the componentof a disc brakeagainst which the brakepadsare
applied. The material is typically grey iron,[18] a formof cast iron. Thedesign of
the disc varies somewhat. Some are simply solid, but others arehollowed out with
fins or vanes joining together the disc's two contactsurfaces (usually included as
part of a casting process). Theweight andpower of the vehicle determines the
need for ventilated discs.[13] The"ventilated" disc design helps to dissipatethe
generated heat and iscommonly used on the more-heavily-loaded frontdiscs.
Beginning in the 1960s on racing cars, it is now common for
high-performancecars, motorcycles and even bicycles, to havebrakes with
drilled holes or slots. This "cross-drilling" is donefor a number of reasons:
heat dissipation, surface-water dispersal, brakesquealelimination, mass
reduction, or marketing cosmetics. An alleged disadvantageof cross drilling
for racing or other severe conditions is that the holes might become a source
of stress cracks.

14. Ceramic composites
Ceramic discs are used in somehigh-performancecars and heavy vehicles.The
firstdevelopment of the modern ceramic brake was made by British engineers
working in the railwayindustry for TGV applications in 1988. The objective was to
reduce weight, the number of brakes per axle,as well as provide stable friction
fromvery high speeds and all temperatures. The result was a carbon-
fibrereinforced ceramic process which is now used in various forms
forautomotive, railway, and aircraft brakeapplications.
Due to the high heat tolerance and mechanical strength of ceramiccomposite
discs, they areoften used on exotic vehicles wherethecost is not prohibitive to
the application. They are also found inindustrial applications wherethe ceramic
disc's light weight andlow-maintenanceproperties justify the cost relative to
alternatives.Compositebrakes can withstand temperatures that would make
steeldiscs bendable.
Adjustment mechanism
In automotive applications, the piston seal has a squarecross section, also known
as a square-cutseal.
As the piston moves in and out, the seal drags and stretches on the piston,causing
the seal to twist. The sealdistorts approximately 1/10 of a millimeter. The piston is

15. allowed to move out freely, but the slight amountof drag caused by the seal stops
the piston fromfully retracting to its previous position when the brakes are
released, and so takes up the slack caused by the wear of the brakepads,
eliminating the need for returnsprings.
Calipers
The brake caliper is the assembly which houses the brake pads andpistons. The
pistons are usually made of plastic, aluminiumorchrome-plated steel.
Calipers are of two types, floating or fixed. A fixed caliper does notmove relative
to the disc and is thus less tolerant of discimperfections. Ituses one or more pairs
of opposing pistons to clampfromeach side of the disc, and is more complex and
expensive than afloating caliper.
A floating caliper (also called a "sliding caliper") moves with respectto the disc,
along a line parallel to the axis of rotation of the disc; apiston on one side of the
disc pushes the inner brakepad until itmakes contact with the braking surface,
then pulls the caliper body with the outer brakepad so pressureisapplied to both
sides of the disc. Floating caliper (single piston) designs are subjectto sticking
failure,caused by dirt or corrosion entering at least one mounting mechanismand
stopping its normal movement.This can lead to the caliper's pads rubbing on the

16. Brake pads
Brake pads are designed for high friction with brake pad material embedded in
the disc in the process ofbedding while wearing evenly. Friction can be divided
into two parts. They are: adhesiveand abrasive.
Depending on the properties of the material of both the pad and the disc and the
configuration and the usage,pad and disc wear rates will vary considerably. The
properties that determine material wear involvetrade-offs between performance
and longevity.
The brake pads mustusually be replaced regularly (depending on pad material,
and drivestyle), and some areequipped with a mechanismthat alerts drivers that
replacement is needed, such as a thin piece of soft metalthat rubs againstthe disc
when the pads are too thin causing the brakes to squeal, a softmetal tab
embeddedin the pad material that closes an electric circuit and lights a warning
light when the brakepad gets thin, oran electronic sensor.
Generally road-going vehicles have two brakepads per caliper, while up to six are
installed on each racingcaliper, with varying frictionalproperties in a staggered
pattern for optimum performance.
Early brakepads (and linings) contained asbestos, producing dustwhich should
not be inhaled. Althoughnewer pads can be made of ceramics, Kevlar, and other
plastics, inhalation of brake dustshould still beavoided regardless of material.

17. Drum brake
A drumbrake is a brakethat uses friction caused by a set ofshoes or pads that
press outward againsta rotating cylindershapedpart called a brakedrum.
The term drum brake usually means a brake in which shoes presson the inner
surfaceof the drum. When shoes press on theoutside of the drum, it is usually
called a clasp brake. Wherethedrumis pinched between two shoes, similar to a
conventionaldisc brake, it is sometimes called a pinch drum brake, thoughsuch
brakes are relatively rare. A related type called a band brakeuses a flexible belt or
"band" wrapping around the outsideof adrum.
Contents Drum Brake
1 History
2 Components
2.1 Backing plate
2.2 Brakedrum
2.3 Wheel cylinder
2.4 Brakeshoe
3 Drumbrakedesigns
4 Advantages
5 Disadvantages

18. History
The modern automobile drum brakewas firstused in a car madeby Maybach in
1900, although the principle was only laterpatented in 1902 by Louis Renault. He
used woven asbestoslining for the drumbrakelining, as no alternative dissipated
heatlike the asbestos lining, though Maybach had used a lesssophisticated drum
brake. In the first drumbrakes, levers androds or cables operated the shoes
mechanically. Fromthe mid1930s,oilpressurein a small wheel cylinder and
pistons (as inthe picture) operated the brakes, though somevehicles
continuedwith purely mechanical systems for decades. Some designs havetwo
wheel cylinders.
As the shoes in drumbrakes wear, brakes required regularmanualadjustment
until the introduction of selfadjustingdrumbrakesin the 1950s. Drums areprone
to brake fading with repeated use.[1][2]
In 1953, Jaguar fielded three cars equipped with disc brakes at Le Mans, where
they won, in large partdue to their superior braking over drumequipped rivals. [3]
This spelled the beginning of the crossoverof drumbrakesto disc brakes in
passenger cars. From1955 to the 1970s, disc brakes gradually replaced
drumbrakes on the front wheels of cars. Now practically all cars usedisc brakes
on the front wheels,and many use disc brakes on all four wheels.
Components
Drumbrakecomponents include the backing plate, brakedrum, shoe, wheel
cylinder, and variousspringsand pins.
Backing plate
The backing plate provides a base for the other components. Itattaches to the
axle sleeve and provides anon-rotatingrigid mounting surfacefor the wheel

19. cylinder, brake shoes, and assorted hardware. Sinceallbraking operations exert
pressureon the backing plate, it must be strong and wear-resistant.Levers for
emergency or parking brakes, and automatic brakeshoeadjuster werealso added
in recent years.
Brake drum
The brake drumis generally made of a special type of castironthat is
heatconductiveand wearresistant.Itrotates with thewheel and axle. When a
driver applies the brakes, theliningpushes radially against the inner surfaceof the
drum, and theensuing friction slows or stops rotation of the wheel and axle,and
thus the vehicle. This friction generates substantial heat.
Wheel cylinder
One wheel cylinder operates the brakeon each wheel. Twopistons operatethe
shoes, one at each end of the wheel cylinder.Theleading shoe(closestto the
frontof the vehicle) is known astheprimary shoe. The trailing shoeis known as
the secondaryshoe. Hydraulic pressurefromthemaster cylinder acts on the

20. piston cup, pushing the pistons toward the shoes, forcing themthe drum. When
the driver releases the brakes, the brakeshoesprings restoretheshoes to their
original (disengaged)position. Theparts of the wheel cylinder are shown to the
right.
Brake shoe
Brake shoes aretypically made of two pieces of steel weldedtogether. The friction
material is either riveted to the lining table or attached with adhesive. The
Crescentshapedpieceis called the Web and contains holes and slots in different
shapes for returnsprings, holddownhardware, parking brakelinkageand
selfadjustingcomponents. Allthe applicationforce of the wheel cylinder is applied
through the web to the lining table and brake lining. The edge of
the lining table generally has three “V"shapednotches or tabs on each side called
nibs. The nibs restagainstthe supportpads of the backing plate to which the
shoes are installed. Each brakeassembly hastwo shoes, a primary and secondary.
The primary shoe is located toward the front of the vehicle and hasthe lining
positioned differently from the secondary shoe. Quite often, the two shoes are
interchangeable,so close inspection for any variation is important.
Linings must be resistantto heat and wear and have a high friction coefficient
unaffected by fluctuationsin temperature and humidity.

21. Emergency brake
The parking brakes (emergency brake) systemcontrols the brakes through a
series of steel cables that areconnected to either a hand lever or a foot pedal. The
idea is that the systemis fully mechanical andcompletely bypasses thehydraulic
systemso that the vehicle can be broughtto a stop even if there is a
total brakefailure. Here the cable pulls on a lever mounted in the brakeand is
directly connected to thebrake shoes. This has the effect of bypassing the wheel
cylinder and controlling the brakes directly.
Drum brake designe
Drumbrakes are typically described as either leading/trailing ortwin leading.[4]
Rear drumbrakes are typically of a leading/trailing design (fornonservo
systems), or primary/secondary (for duo servosystems)theshoes being moved by
a single doubleactinghydraulic cylinder and hinged at the same point.[4] In this
design,oneof the brake shoes always experiences the selfapplyingeffect,
irrespectiveof whether the vehicle is moving forwards orbackwards.[4] This is
particularly useful on the rear brakes, wheretheparking brake(handbrakeor

22. footbrake) mustexert enoughforceto stop the vehicle from traveling backwards
and hold it ona slope. Provided the contact area of the brakeshoes is large
enough, which isn't always the case, theselfapplyingeffect can securely hold a
vehicle when the weight is transferred to the rear brakes due tothe incline of a
slope or the reversedirection of motion. A further advantageof using a single
hydrauliccylinder on the rear is that the opposite pivot may be made in the form
of a doublelobedcam that isrotated by the action of the parking brakesystem.
Frontdrum brakes may be of either design in practice, but the twin leading design
is more effective.[4]This design uses two actuating cylinders arranged so that
both shoes usethe selfapplyingcharacteristicwhen thevehicle is moving
forwards.[4] Thebrakeshoes pivotat oppositepoints to each other.[4] This
gives the maximum possiblebraking when moving forwards, butis not so
effective when the vehicle istraveling in reverse.[4]
The optimum arrangementof twin leading frontbrakes with leading/trailing
brakes on the rear allowsmorebraking forceat the frontof the vehicle when it is
moving forwards, with less at the rear. Thishelps prevent the rear wheels from
locking up, but still provides adequate braking at the rear.[4]
Roller brakes are specially designed drumbrakes for bicycles,mounted to the
side of the wheel's hub.
Advantages
Drumbrakes are used in most heavy duty trucks, somemedium and light duty
trucks, and few cars, dirtbikes, and ATVs. Drumbrakes areoften applied to the
rear wheels since mostof the stopping forceisgenerated by the front brakes of
the vehicle and therefore the heat generated in the rear is significantlyless. Drum
brakes allow simple incorporation of a parking brake.
Drumbrakes are also occasionally fitted as the parking (and emergency) brake
even when the rearwheels use disc brakes as the main brakes. Many rear disc
braking systems usea parking brakein whichthe piston in the caliper is actuated
by a cam or screw. This compresses the pads againstthe rotor.However, this type
of systembecomes much more complicated when the rear disc brakes use fixed,

23. Multipistoncalipers. In this situation, a small drumis usually fitted within or as
part of the brakedisc.This type of brakeis also known as a banksia brake.
In hybrid vehicle applications, wear on braking systems is greatly reduced by
energy recovering motorgenerators(seeregenerativebraking), so somehybrid
vehicles such as the GMC Yukon Hybrid andToyota Prius (except the third
generation) usedrum brakes.
Disc brakes rely on pliability of caliper seals and slightrunout to release pads,
leading to drag, fuelmileage loss, and disc scoring. Drumbrakereturn springs give
more positive action and, adjustedcorrectly, often have less drag when released.
Itis however possibleto design special seals that retractthe piston on a disc
brake.
To list advantages of drum brakes:
* less expensive to produce
* slightly lower frequency of maintenance due to better corrosion resistance
compared to disks.
* Built-inself energizing effect requires less input force(such as hydraulic
pressure).
* wheel cylinders are somewhatsimpler to recondition compared to calipers.
* minor weight savings, primarily frommuch smaller and lighter hydraulic
cylinders vs. calipers.

24. Disadvantages
Drumbrakes, like mostother brakes, convertkinetic energy into heat by
friction.[4] This heat shoulddissipateinto the surrounding air, butcan justas
easily transfer to other braking systemcomponents.Brakedrums mustbelarge to
cope with the massiveforces involved, and mustbe able to absorb anddissipatea
lot of heat. Heat transfer to air can be aided by incorporating cooling fins onto the
drum.However, excessiveheating can occur due to heavy or repeated braking,
which can cause the drum todistort, leading to vibration under braking.
The other consequence of overheating is brakefade.[4] This is due to one of
severalprocesses or moreusually an accumulation of all of them.1. When the
drums are heated by hard braking, the diameter of the drumincreases slightly
due tothermal expansion, so the shoes mustmove farther and the driver must
press the brakepedalfarther.2. The properties of the friction material can change
if heated, resulting in less friction. This can be amuch larger problem with drum
brakes than disc brakes, sincethe shoes are inside the drumand
not exposed to cooling ambient air. The loss of friction is usually only temporary
and the materialregains its efficiency when cooled,[4] but if the surfaceoverheats
to the point where it becomes glazed the reduction in braking efficiency is more
permanent. Surfaceglazing can be worn awaywith further useof the brakes, but
that takes time.3. Excessivebrakedrum heating can causethe brakefluid to
vaporize, which reduces the hydraulicpressureapplied to the brakeshoes.[4]
Therefore, the brakes provideless deceleration for a given
amount of pressureon the pedal. The effect is worsened by poor maintenance.
Brake fluid that isold and has absorbed moisturehas a lower boiling point, so
brakefade occurs sooner.[4]Brakefadeis not always dueto overheating. Water
between the friction surfaces and the drumcan act asa lubricant and reduce
braking efficiency.[4] The water tends to stay until heated sufficiently to vaporize,
at which point braking efficiency returns. All friction braking systems havea
maximum theoretical rateof energy conversion. Oncethat rate is reached,
applying greater pedal pressuredoesn'tchangeit—infact, the effects mentioned
can substantially reduce it. Ultimately, this is whatbrake fade is, regardless
of the mechanisms of its causes. Disc brakes arenot immune to any of these
processes, butthey dealwith heat and water more effectively than drums.
Drumbrakes can be grabby if the drumsurfacegets light rustor if the brakeis
cold and damp, giving the

25. REFERENCES
 http://www.mahindrabolero.in/
 http://business.mapsofindia.com/automobile/
 http://en.wikipedia.org/wiki/Automobile_industry_in_India
Table for the non considerationmahindra
 1.Which four wheeler do you own?