MAHINDRA & MAHINDRA Ltd. DARBHANGA ( BIHAR )

PROJECT ON BOLERO ( EX/SLX/SLE/ZLX ) BRAKES

UDIT NARAYAN 14-ME-073

A summer training report submitted In Partial fulfillment of my Bachelor

B.TECH (Mechanical Engineering)

GANGA INSTIT-UTE OF TECHNOLOGY & MANAGEMENT KABLANA , JHAJJAR

AFFILIATED TO M.D. UNIVERSITY, ROHTAK MAY 2009

PROJECT ON

“LAKSHMI PRECISION SCREWS LTD. ROHTAK”

A SUMMER TRAINING PROJECT REPORT

Submitted by RAVINDER

15-LME-109

In partial fulfillment for the award of the degree of BACHELOR OF TECHNOLOGY in MECHANICAL ENGINEERING

GANGA INSTITUTE OF TECHNOLOGY AND MANAGEMENT KABLANA, JHAJJAR AFFILIATED TO M.D UNIVERSITY, ROHTAK

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.

AcknowledgementI 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

Training Details

NAME: AQUIB JAWEDYEAR: 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 , 247026Email: info@shivshakti.biz

DESIGNATION OF GUIDE: Mr. ASFAQUE ALAM ( Head Technical Cell ) 

PERIOD: FROM- 20th June 2016 to 01st Aug 2016

DURATION: 42- DAYS. 

FIELD OF TRAINING:  PROJECT ON MAHINDRA BOLERO ( EX / SLX /SLE/ZLX ) BRAKES

TABLE OF CONTENTS

BONAFIDE CERTIFICATE…………………………………………..

DECLARATION……………………………………………………………...

ACKNOWLEDGEMENT……………………………………………………

TRAINING DETAIL…………………………………………………………

INTRODUCTION OF COMPONY…………………………………………..

1.MAHINDRA BOLERO………………………………………………….......1.1 BOLERO IMAGE - EX & SLE……………………………………….......1.2 BOLERO IMAGE – 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……………………………………………............AUTOMOBILE INDUSTRY

The automobi le industry has changed the way people l i ve and work. The ear l iest o f modern cars was manufactured in the year 1895.

Shortly the first appearance of the car followed in India. As the century turned, three carswere imported in Mumbai (India). Within decade there were total of 1025 cars in the city.

The dawn of automobile actually goes back to 4000 years when the first wheel was usedfor transportation in India. In the beginning 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 - powered vehicle was created.Brothers Charles and Frank Duryea introduced the actual horseless carriage in the year 1893. It was the first internal-combustion motor car of America, and it was followed byHenry Ford’s first experimental car that same year.One of the highest-rated early luxury automobiles was the 1909 Rolls-Royce SilverGhostthat featured a quiet 6cylinder engine, leather interior, folding windscreensand hood, and an aluminum body.Chauffeurs usually drove it and emphasis was on comfort and style rather than speed.During the 1920s, the cars exhibited design refinements such as balloon tires, pressed-steel wheels, and four-wheel brake

Graham Paige DC Phaeton of 1929 featured an 8-cylinder engine and an aluminum body.The 1937 Pont iac De Luxe  sedan   had roomy interior and rear-hinged back door thatsui ted more to the needs of fami l ies . In 1930s , vehic les were less boxy and more streamlined than their predecessor was.The 1940s saw features like automatic transmission, sealed-beam headlights, and tubelesstires.

The year 1957 brought powerful high-performance cars such as Mercedes-Benz 300SL. Itwas built on compact and stylized lines, and was capable of 230 kmph(144 mph).This was the Indian automobile history, and today modern cars aregenerally light, aerodynamically shaped, and compact.

MAHINDRA BOLERO

M a h i n d r a   B o l e r o   i s   o n e   o f   t h e   m o s t   s u c c e s s f u l   a n d   p o p u l a r  u t i l i t y   v e h i c l e   o f   t h e Mahindra 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

BRAKE:

A brake is a mechanical device which inhibits motion.

WORKING OF BRAKES

•A COMMON MISCONCEPTION ABOUT 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 DEVELOPED BY 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.

TYPES OF BRAKES

MECHANICAL BRAKES •DRUM BRAKES •DISC BRAKES HYDRAULIC BRAKES POWER BRAKES •AIR BRAKES •AIR HYDRAULIC BRAKES •VACCUM BRAKES •ELECTRIC BRAKES

DISC BRAKE

A disc brake is a type of brake that uses calipers to squeeze pairs ofpads against a 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 wasteheat which must be dispersed. Hydraulic disc brakes are the mostcommonly used form of brake for motor vehicles but the principlesof a disc brake are applicable to almost any rotating shaft.

Compared to drum brakes, disc brakes offer better stoppingperformance because the disc is more readily cooled. As aconsequence discs are less prone to the brake fade caused whenbrake components overheat. Disc brakes also recover more quicklyfrom immersion (wet brakes are less effective than dry ones).

Most drum brake designs have at least one leading shoe, which gives a servo-effect. By contrast, a discbrake has no self-servo effect and its braking force is always proportional to the pressure placed on the brakepad by the braking system via any brake servo, braking pedal, or lever. This tends to give the driver better. "feel" and helps to avoid impending lockup. Drums are also prone to "bell mouthing" and trap worn liningmaterial within the assembly, both causes of various braking problems.

CONTENTS OF DISC BRAKE1 History2 Brake disc2.1 Ceramic composites3 Calipers4 Brake pads

BRAKE DISC

The brake disc is the component of a disc brake against which the brake padsare applied. The material is typically grey iron,[18] a form of 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). The weight andpower of the vehicle determines the need for ventilated discs.[13] The"ventilated" disc design helps to dissipate the generated heat and iscommonly used on the more-heavily-loaded front discs.

Beginning in the 1960s on racing cars, it is now common forhigh-performance cars, motorcycles and even bicycles, to have brakes withdrilled holes or slots. This "cross-drilling" is done for a number of reasons:heat dissipation, surface-water dispersal, brake squeal elimination, massreduction, or marketing cosmetics. An alleged disadvantage of cross drillingfor racing or other severe conditions is that the holes might become a sourceof stress cracks.

Ceramic composites

Ceramic discs are used in some high-performance cars and heavy vehicles.The first development 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 from very high speeds and all temperatures. The result was a carbon-fibrereinforced ceramic process which is now used in various forms forautomotive, railway, and aircraft brake applications.

Due to the high heat tolerance and mechanical strength of ceramiccomposite discs, they are often used on exotic vehicles where thecost is not prohibitive to the application. They are also found inindustrial applications where the ceramic disc's light weight andlow-maintenance properties justify the cost relative to alternatives.Composite brakes can withstand temperatures that would make steeldiscs bendable.

Adjustment mechanism

In automotive applications, the piston seal has a square cross section, also known as a square-cut seal.

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

allowed to move out freely, but the slight amountof drag caused by the seal stops the piston from fully retracting to its previous position when the brakes arereleased, and so takes up the slack caused by the wear of the brake pads, 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. It uses one or more pairs of opposing pistons to clampfrom each 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 brake pad until itmakes contact with the braking surface, then pulls the caliper body with the outer brake pad so pressure isapplied to both sides of the disc. Floating caliper (single piston) designs are subject to sticking failure,caused by dirt or corrosion entering at least one mounting mechanism and stopping its normal movement.This can lead to the caliper's pads rubbing on the

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: adhesive and 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 must usually be replaced regularly (depending on pad material, and drivestyle), and some areequipped with a mechanism that alerts drivers that replacement is needed, such as a thin piece of soft metalthat rubs against the disc when the pads are too thin causing the brakes to squeal, a soft metal tab embeddedin the pad material that closes an electric circuit and lights a warning light when the brake pad gets thin, oran electronic sensor.

Generally road-going vehicles have two brake pads per caliper, while up to six are installed on each racingcaliper, with varying frictional properties in a staggered pattern for optimum performance.

Early brake pads (and linings) contained asbestos, producing dust which should not be inhaled. Althoughnewer pads can be made of ceramics, Kevlar, and other plastics, inhalation of brake dust should still beavoided regardless of material.

Drum brake

A drum brake is a brake that uses friction caused by a set ofshoes or pads that press outward against a rotating cylindershapedpart called a brake drum.

The term drum brake usually means a brake in which shoes presson the inner surface of the drum. When shoes press on theoutside of the drum, it is usually called a clasp brake. Where thedrum is 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 outside of adrum.

Contents Drum Brake1 History2 Components2.1 Backing plate2.2 Brake drum2.3 Wheel cylinder2.4 Brake shoe3 Drum brake designs4 Advantages5 Disadvantages

History

The modern automobile drum brake was first used in a car madeby Maybach in 1900, although the principle was only laterpatented in 1902 by Louis Renault. He used woven asbestoslining for the drum brake lining, as no alternative dissipated heatlike the asbestos lining, though Maybach had used a lesssophisticated drum brake. In the first drum brakes, levers androds or cables operated the shoes mechanically. From the mid1930s,oil pressure in a small wheel cylinder and pistons (as inthe picture) operated the brakes, though some vehicles continuedwith purely mechanical systems for decades. Some designs havetwo wheel cylinders.

As the shoes in drum brakes wear, brakes required regularmanual adjustment until the introduction of selfadjustingdrumbrakes in the 1950s. Drums are prone 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 drum equipped rivals. [3] This spelled the beginning of the crossoverof drum brakes to disc brakes in passenger cars. From 1955 to the 1970s, disc brakes gradually replaceddrum brakes on the front wheels of cars. Now practically all cars use disc brakes on the front wheels,and many use disc brakes on all four wheels.

Components

Drum brake components include the backing plate, brake drum, shoe, wheel cylinder, and varioussprings and pins.

Backing plate

The backing plate provides a base for the other components. It attaches to the axle sleeve and provides anon-rotatingrigid mounting surface for the wheel

cylinder, brake shoes, and assorted hardware. Since allbraking operations exert pressure on the backing plate, it must be strong and wear-resistant.Levers foremergency or parking brakes, and automatic brakeshoeadjuster were also added in recent years.

Brake drum

The brake drum is generally made of a special type of cast ironthat is heatconductiveand wearresistant.It rotates with thewheel and axle. When a driver applies the brakes, the liningpushes radially against the inner surface of 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 brake on each wheel. Twopistons operate the shoes, one at each end of the wheel cylinder.The leading shoe (closest to the front of the vehicle) is known asthe primary shoe. The trailing shoe is known as the secondaryshoe. Hydraulic pressure from the master cylinder acts on the

piston cup, pushing the pistons toward the shoes, forcing themthe drum. When the driver releases the brakes, the brakeshoe springs restore the shoes to their original (disengaged)position. The parts of the wheel cylinder are shown to the right.

Brake shoe

Brake shoes are typically made of two pieces of steel weldedtogether. The friction material is either riveted to the lining table or attached with adhesive. TheCrescentshapedpiece is called the Web and contains holes and slots in different shapes for returnsprings, holddownhardware, parking brake linkage and selfadjustingcomponents. All the applicationforce of the wheel cylinder is applied through the web to the lining table and brake lining. The edge ofthe lining table generally has three “V"shapednotches or tabs on each side called nibs. The nibs restagainst the support pads of the backing plate to which the shoes are installed. Each brake assembly 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 resistant to heat and wear and have a high friction coefficient unaffected by fluctuationsin temperature and humidity.

Emergency brake

The parking brakes (emergency brake) system controls the brakes through a series of steel cables that areconnected to either a hand lever or a foot pedal. The idea is that the system is fully mechanical andcompletely bypasses the hydraulic system so that the vehicle can be brought to a stop even if there is atotal brake failure. Here the cable pulls on a lever mounted in the brake and is directly connected to thebrake shoes. This has the effect of bypassing the wheel cylinder and controlling the brakes directly.

Drum brake designe

Drum brakes are typically described as either leading/trailing ortwin leading.[4]

Rear drum brakes are typically of a leading/trailing design (fornonservosystems), or primary/secondary (for duo servosystems) the shoes being moved by a single doubleactinghydraulic cylinder and hinged at the same point.[4] In this design,one of the brake shoes always experiences the selfapplyingeffect, irrespective of whether the vehicle is moving forwards orbackwards.[4] This is particularly useful on the rear brakes, wherethe parking brake (handbrake or

footbrake) must exert enoughforce to stop the vehicle from traveling backwards and hold it ona slope. Provided the contact area of the brake shoes 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 reverse direction of motion. A further advantage of 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 brake system.

Front drum 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 use the selfapplyingcharacteristicwhen the vehicle is moving forwards.[4] The brake shoes pivot at opposite points to each other.[4] Thisgives the maximum possible braking when moving forwards, but is not so effective when the vehicle istraveling in reverse.[4]

The optimum arrangement of twin leading front brakes with leading/trailing brakes on the rear allowsmore braking force at the front of 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 drum brakes for bicycles,mounted to the side of the wheel's hub.

AdvantagesDrum brakes are used in most heavy duty trucks, some medium and light duty trucks, and few cars, dirtbikes, and ATVs. Drum brakes are often applied to the rear wheels since most of the stopping force isgenerated 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.

Drum brakes 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 use a parking brake in whichthe piston in the caliper is actuated by a cam or screw. This compresses the pads against the rotor.However, this type of system becomes much more complicated when the rear disc brakes use fixed,

Multipistoncalipers. In this situation, a small drum is usually fitted within or as part of the brake disc.This type of brake is also known as a banksia brake.

In hybrid vehicle applications, wear on braking systems is greatly reduced by energy recovering motorgenerators(see regenerative braking), so some hybrid vehicles such as the GMC Yukon Hybrid andToyota Prius (except the third generation) use drum brakes.

Disc brakes rely on pliability of caliper seals and slight runout to release pads, leading to drag, fuelmileage loss, and disc scoring. Drum brake return springs give more positive action and, adjustedcorrectly, often have less drag when released. It is however possible to 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 somewhat simpler to recondition compared to calipers.

* minor weight savings, primarily from much smaller and lighter hydraulic cylinders vs. calipers.

Disadvantages

Drum brakes, like most other brakes, convert kinetic energy into heat by friction.[4] This heat shoulddissipate into the surrounding air, but can just as easily transfer to other braking system components.Brake drums must be large to cope with the massive forces involved, and must be able to absorb anddissipate a lot of heat. Heat transfer to air can be aided by incorporating cooling fins onto the drum.However, excessive heating 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 brake fade.[4] This is due to one of several processes or moreusually an accumulation of all of them.1. When the drums are heated by hard braking, the diameter of the drum increases slightly due tothermal expansion, so the shoes must move farther and the driver must press the brake pedalfarther.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, since the shoes are inside the drum andnot exposed to cooling ambient air. The loss of friction is usually only temporary and the materialregains its efficiency when cooled,[4] but if the surface overheats to the point where it becomes glazed the reduction in braking efficiency is more permanent. Surface glazing can be worn awaywith further use of the brakes, but that takes time.3. Excessive brake drum heating can cause the brake fluid to vaporize, which reduces the hydraulicpressure applied to the brake shoes.[4] Therefore, the brakes provide less deceleration for a givenamount of pressure on the pedal. The effect is worsened by poor maintenance. Brake fluid that isold and has absorbed moisture has a lower boiling point, so brake fade occurs sooner.[4]Brake fade is not always due to overheating. Water between the friction surfaces and the drum can 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 have a maximum theoretical rateof energy conversion. Once that rate is reached, applying greater pedal pressure doesn't change it—infact, the effects mentioned can substantially reduce it. Ultimately, this is what brake fade is, regardlessof the mechanisms of its causes. Disc brakes are not immune to any of these processes, but they dealwith heat and water more effectively than drums.Drum brakes can be grabby if the drum surface gets light rust or if the brake is cold and damp, giving the

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?