PROJECT REPORT

ON

AUTOMATIC INFLATION

OF TIRES SUBMITTED BY: SUBMITTED TO:

Gursharan singh (100441130706) Prof. Sandeep Devgan

Jagmohan Manes (100441130714) Mechanical Engg.Deptt.

Anuj Khattri (100441121465)

Shukhjinder Singh (100441130776)

K.C.E.T AMRITSAR

2013

K.C.E.T AMRITSAR

BONAFIDE CERTIFICATE

Certified that this project report “Automatic inflation of tires” is the bonafide

work of “Gursharan singh, Jagmohan Manes, Anuj Khattri, Shukhjinder Singh ”

they carried out the project work under my supervision and guidance.

Project Guide:-

Er. Jasjevan Singh

Lec. Mechanical Engg. Deptt

SIGNATURE

CONTENTS

1. INTRODUCTION

2. TIRE INFLATION BASICS

3. SELF INFLATING SYSTEMS

4. CENTRAL TIRE INFLATING SYSTEM

5. DESIGN OF MODEL

6. AIR COMPRESSOR

7. PRESSURE SWITCH

8. NON RETURN VALVE

9. AIR SEAL

10. WORKING OF MODEL

11. COST REPORT

12. ADVANTAGES

13. CONCLUSION

14. REFRENCES

ACKNOWLEDGEMENT

First of all we thank to avail this opportunity to express my sincere

gratitude towards Mr. R.S Mahal , Head of Mechanical Engineering Department,

for permitting us to make this project. We also want to express our profound

gratitude towards our project guide Mr. Jasjevan Singh, for his inspiring

assistance, encouragement and useful guidance.

We are also indebted to all the teaching and non- teaching staff of the

department of mechanical engineering for their cooperation and suggestions, which

is the spirit behind this project. Last but not the least, we wish to express our

sincere thanks to all my friends for their goodwill and constructive ideas.

Introduction

This project work titled automatic tire inflation system deals with the difficulty in

driving the vehicles with low and high tyre pressure. The irregular and uneven tyre

pressures causes difficulty in driving and even leads to the accidents. This can be

implemented on the vehicles which have air braking system .The project automatic

tyre inflation system is concentrated in maintaining the tyre pressures and thereby

reducing the driving difficulties. This is done by mechanical means and not by

using any sensors and other electronics. The air can be inflated into the tyres

without stopping the vehicle. The air from the air tank is used for inflating the

tyres. The air from the tank is sent to the tyres through a one way valve. The twist

made in the air hose is prevented by a joint. The design of the system is very

simple and also very economical. Therefore it can be implemented easily in the

vehicles. The space requirement for the installation is also very less.

Automatic tire inflation systems can save tire maintenance costs and improve

fuel economy by nearly 1 percent, saving 100 gallons of fuel and eliminating 1

metric ton of greenhouse gas emissions per year. Properly inflated tires also

have fewer punctures and a longer life expectancy.

What is the challenge? When not properly inflated, tires flex more under load. This produces heat and

increases rolling resistance, which wastes fuel. Truck tires inflated 10 pounds per

square inch (psi) below recommended air pressure levels can reduce truck fuel

economy between 0.5 percent and 1 percent. Since the bulk of the load is carried in

the trailer, a 10-psi underinflation in a trailer tire may have nearly twice the impact

on truck fuel economy as the same amount of underinflation in a drive tire.

Heat and stress from improper inflation softens and deflects tire components,

causing faster and more uneven wear, which shortens the life of the tire.

Underinflated tires have more frequent punctures, increasing the risk of tire

failures that could lead to costly road service and loss of revenue.Despite the

importance, a recent survey of combination trucks found that less than half the

tires surveyed were within 5 percent of the recommended inflation pressure.

Another industry survey indicates only 8 percent of truck drivers check tire

pressure with a tire gage before each trip. One reason fleets may find it difficult to

keep tires properly inflated is because truck tires can lose up to 2 psi each month,

even if the rim seal and valve stems are tight. A fleet may not be able to inspect or

monitor its’ trailer tires regularly due to the fact that extended periods of time are

spent away from service yards and because trailers are interchangeable. This places

greater responsibility for checking tire pressure onto drivers.

What is the solution? Automatic tire inflation (ATI) systems monitor and continually adjust the level of

pressurized air in tires, maintaining proper tire inflation automatically even while

the truck is in motion. One ATI system uses the vehicle’s own air-brake

compressor to supply air to all the tires. Once an ATI system is installed, it should

not require any special attention from the drivers. This eliminates the need to check

tire pressure manually, which saves time and labor while ensuring consistent and

proper tire inflation.

Automatic Air Inflation System

Tire-Inflation Basics

According to AAA, about 80 percent of the cars on the road are driving with one or

more tires underinflated. Tires lose air through normal driving (especially after

hitting pot holes or curbs), permeation and seasonal changes in temperature. They

can lose one or two psi (pounds per square inch) each month in the winter and even

more in the summer. And, you can't tell if they're properly inflated just by looking

at them. You have to use a tire-pressure gauge. Not only is underinflation bad for

your tires, but it's also bad for your gas mileage, affects the way your car handles

and is generally unsafe.

When tires are underinflated, the tread wears more quickly. According to

Goodyear, this equates to 15 percent fewer miles you can drive on them for every

20 percent that they're underinflated. Underinflated tires also overheat more

quickly than properly inflated tires, which causes more tire damage. The faded

areas below indicate areas of excessive tread wear.

Because tires are flexible, they flatten at the bottom when they roll. This contact

patch rebounds to its original shape once it is no longer in contact with the ground.

This rebound creates a wave of motion along with some friction. When there is less

air in the tire, that wave is larger and the friction created is greater -- and friction

creates heat. If enough heat is generated, the rubber that holds the tire's cords

together begin to melt and the tire fails. See How Tires Work to learn more.

Because of the extra resistance an underinflated tire has when it rolls, your car's

engine has to work harder. AAA statistics show that tires that are underinflated by

as little as 2 psi reduce fuel efficiency by 10 percent. Over a year of driving, that

can amount to several hundred dollars in extra gas purchases.

How Tires Fails:-

Tires flatten at the bottom when they roll.

Rebounds to its original shape once it is no longer in contact with the

ground.

Creates a wave of motion along with some friction.

Under inflated tires, waves are larger and the friction created is greater

Friction creates heat.

If enough heat is generated, the rubber that holds the tire's cords together

begin to melt

And the tire fails

Disadvantages of improper inflation:-

Hence the friction created is greater.

Friction creates heat and if enough heat is generated the rubber that holds the

tire cords melts and tire trails.

Because of the extra resistance an under inflated tire has when it rolls,the

cars engine has to work harder.

As it effects mileage it can cause severe loss in the cost considerations.

Self-inflating Systems:-

Tire-inflation systems general goals:

Detect when the air pressure in a particular tire has dropped - This

means they have to constantly (or intermittently) monitor the air

pressure in each tire.

Notify the driver of the problem

Inflate that tire back to the proper level - This means there has to be an air

supply as well as a check valve that opens only when needed.

Parts of A Self-inflating System

Valve to isolate individual tires

Central sensors for sensing the tire pressures.these

Air source, which is usually an existing onboard source

Get the air from the air source to the tires, which is usually through

the axle Systems either use a sealed-hub axle with a hose from the hub

to the tire valve or else they run tubes through the axle with the axle

acting as a conduit.

A pressure relief vent to vent air from the tire without risking damage

to the hub or rear-axle seals.

Central Tire Inflation System (CTIS):-

The idea behind the CTIS is to provide control over the air pressure in each

tire.

As a way to improve performance on different surfaces.

Driver can give direct control over the air pressure in each tire

To maintain pressure in the tires if there is a slow leak or puncture.

System controls inflation automatically based on the selected pressure the

driver has set.

CTIS: Inside:-

Parts are:

A wheel valve

Electronic control unit

Pneumatic control unit

Operator control panel

Speed sensor

Pressure switch

Wheel valve:-

A wheel valve is located at each wheel end.

Part of the wheel valve's job is to isolate the tire from the system when it's

not in use in order to let the pressure off of the seal and extend its life.

The wheel valve also enables on-demand inflation and deflation of the tires.

Operator control panel:-

An operator control panel allows the driver to select tire-pressure modes to

match current conditions.

This dash-mounted panel displays current tire pressures, selected modes and

system status.

When the driver selects a tire-pressure setting, signals from the control panel

travel to the electronic control unit to the pneumatic control unit to the wheel

valves.

Pressure Switch:-

This type of system uses air from the same compressor that supplies air to

the brakes.

A pressure switch makes sure the brake system gets priority, preventing the

CTIS from taking air from the supply tank until the brake system is fully

charged.

Future of self inflating tyres:-

one of the major systems in the developmental stages is the entire system.

This system uses a valve that pulls in air from the atmosphere.it then pumps

the air into the underinflated tire using a peristaltic pump action. The goal is

to maintain a specific pressure.

Model:-

This is the general layout of our model of the automatic inflation of tires . It

shows all the parts of the model and gives a general idea of it’s working.

Air Compressor

An air compressor is a device that converts power (usually from an electric motor,

a diesel engine or a gasoline engine) into kinetic energy by compressing and

pressurizing air, which, on command, can be released in quick bursts.

In fact, nowadays it is used for such purposes which you would not have imagined

in till the recent past. Basically, a modern air compressor amplifies the damaging

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compressor’ s tank lays. Most of these have oil free target pumps which make them

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names that would seem more comfortable in the use of a nail gun or jack hammer.

Installing and maintenance takes working knowledge of the application and the

vehicle where it is being installed. The compression that occurs in the air tanks of

your compressors compressor causes moisture to accumulate inside those tanks.

Poly Vinyl Chloride ( PVC) is another synthetic sewing laundry material

composed of thermoplastic lowest polymers which is used to make hose for air

compressors lowest prices special online applications. Everything seemed just fine.

These purchases often entail very few, if any, guarantees. Owning this kind of

compressor sounds fun and helpful but it shop is first important to consider the

things before buying it. This is the volume of the air that the gas compressor

delivers. It is recommended that you purchase an air compressor with a CFM

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Pressure switch

A pressure switch is a form of switch that makes electrical contact when a certain

set pressure has been reached on its input. This is used to provide on/off switching

from a pneumatic or hydraulic source. The switch may be designed to make

contact either on pressure rise or on pressure fall.

Uses of pressure switches include:

Switching off an electrically driven gas compressor when a set pressure is achieved in the reservoir.

Switching off a gas compressor, whenever there is no feed in the suction stage.

in-cell charge control in a battery Switching on/off an alarm light in the cockpit of an aircraft if cabin pressure

(based on altitude) is critically low.

Non return valve

A non-return valve or one-way valve is a mechanical

device, a valve, which normally allows fluid (liquid or gas) to flow through it in

only one direction.

Non-return valve are two-port valves, meaning they have two openings in

the body, one for fluid to enter and the other for fluid to leave. There are various

types of check valves used in a wide variety of applications. non-return valve are

often part of common household items. Although they are available in a wide

range of sizes and costs, non-return valve generally are very small, simple, and/or

inexpensive. non-return valve work automatically and most are not controlled by a

person or any external control; accordingly, most do not have any valve handle or

stem. The bodies (external shells) of most non-return valve are made of plastic or

metal.

An important concept in non-return valve is the

cracking pressure which is the minimum upstream pressure at which the valve will

operate. Typically the non-return valve is designed for and can therefore be

specified for a specific cracking pressure.

Air seal

Air seal is used to prevent the leakage of air from the pipes specially at joints and

bends. It can connect two pipes rigidly so that there is no leakage from them. It

can also makes pipes flexible so that they can be bent. These air seals are of many

materials but we use Teflon for our model.

Working of Our Model

The model mainly shows the automatic inflation of tires. In this model we use

components such as air compressor, non return valve, pressure switch, air seal

Pressure gauges, tire and pipes.

When the pressure of the tire decreases that reading is also shown on the

gauges of the pressure switch then the pressure switch starts the compressor

automatically start compressor and the tire gets inflated automatically to the point

which is preset. That presetting of the pressure value is the function of pressure

switch which can be adjusted to any value. When the compressor starts the

compressed air generated in it goes to the non return valve then to air seal through

the pressure switch which regulates it. This pressure switch is the important part of

our model fitted between non return valve and air seal it has two gauges which

shows the reading of pressure in tire. Then the air goes to the tire when it gets

inflated up to set point then the compressor automatically stops and the air supply

also stops.

We also use some safety concerns for proper and safe working of our

project such as an aluminium pipe is fitted between compressor and pressure

switch. If there is any blockage in the system so that the air cant go further in that

case our compressor can burst which leads to a serious accident. In that case the

aluminium pipe will burst and releases the air and there is no harm to our

compressor. The two gauges are used in the system because in case if any of the

gauge stops working so we get reading from the other gauge.

Cost report

Air Compressor : - Rs. 9500

Pressure Switch : - Rs. 1500

Non Return Valve : - Rs. 400

Air Seal : - Rs. 400

Tire : - Rs. 1000

Supports , Pipes & Board : - Rs. 800

Fitting & Transportation : - Rs.1500

TOTAL : - Rs. 15,100

Automatic Tire Inflation Systems Savings and Benefits Hence the friction created is greater.

Friction creates heat and if enough heat is generated the rubber that holds the tire

cords melts and tire trails. Because of the extra resistance an under inflated tire has when it rolls,the cars

engine has to work harder.

As it effects mileage it can cause severe loss in the cost considerations.

ATI systems can not only extend tire life but truck fleets can also see additional savings from reducing the risk of expensive tire failure caused by underinflation.

Installing an ATI system on a truck’s drive axles and trailer costs up to

$800. For a typical long-haul combination truck, annual fuel savings could reach 100 gallons, saving $380 in fuel cost and eliminating 1 metric ton of greenhouse

gas emissions. Annual tire maintenance costs can also decrease.

The cost of installing an ATI system in a long-haul truck is generally recouped in

just over 2 years through fuel and maintenance cost savings.

CONCLUSION

Thus self inflating tyres help us in attaining certain helpful criterions.

1. It helps in the monitoring of tyre pressure constantly

2. Thus it provides inflation or deflation of the tyre

3. It helps in attaining better mileage

4. It also helps in providing comfortable driving.

5.To control tire pressure according to driving conditions

REFERENCES

1. Crouse.Anglin,” Automotive Mechanics”, Tata McGraw Hills.

2. www.howstuffswork.com

3. www.cycloid.com

4. www.goodyeartyres.com

5. Wikipedia