Shock absorbers at the face of automobile vehicle for

the safety during sudden collision

ABSTRACT

An automobile vehicle safety may have become an issue almost from the beginning of

mechanized road vehicle development. Automobile safety and the avoidance of

automobile accidents or the minimization of harmful effects of accidents, in particular as

pertaining to human life and health, this project has been carried out. Numerous safety

features have been built into cars for years, some for the safety of car's occupants only,

and some for the safety of others.

Two hydraulic springs (shock absorbers) are attached to the front face of automobile

vehicle to absorb the impact load during accidents. This type of system can be easily

attached to all currently manufacture automobiles.

This project will also help to save the life of driver during accidents and collisions, since

suggestion for modifying the design of an automobile vehicle are presented. The design

of driver’s seat is also modified to save his/her life during accident.

The Major Project entitled “Shock absorbers at the face of automobile vehicle for the

safety during sudden collision” Worked on the principal of shock absorbing during

impact loading and operated by two compression springs.

This work, if implemented, would definitely help to saving the life of drivers during car

accident.

CHAPTER 1

INTRODUCTION

1.1 What is an automobile?

An automobile or motor car is a wheeled motor vehicle for transporting passengers,

which also carries its own engine or motor. Most definitions of the term specify that

automobiles are designed to run primarily on roads, to have seating for one to eight

people, to typically have four wheels, and to be constructed principally for the transport

of people rather than goods. However, the term is far from precise because there are

many types of vehicles that do similar tasks.

Automobile comes via the French language, from the Greek language by combining auto

[self] with mobiles [moving]; meaning a vehicle that moves itself, rather than being

pulled or pushed by a separate animal or another vehicle.

Most automobiles in use today are propelled by gasoline (also known as petrol) or diesel

internal combustion engines, which are known to cause air pollution and are also blamed

for contributing to climate change and global warming. Increasing costs of oil-based

fuels, tightening environmental laws and restrictions on greenhouse gas emissions are

propelling work on alternative power systems for automobiles. Efforts to improve or

replace existing technologies include the development of hybrid vehicles, and electric and

hydrogen vehicles which do not release pollution into the air.

1.2 Fuel and propulsion technologies

1.2.1 Diesel

Diesel-engine cars have long been popular in Europe with the first models being

introduced in the 1930s by Mercedes Benz and Citroen. The main benefit of diesel

engines is a 50% fuel burn efficiency compared with 27% in the best gasoline engines. A

down-side of the diesel is the presence in the exhaust gases of fine soot particulates and

manufacturers are now starting to fit filters to remove these. Many diesel-powered cars

can also run with little or no modifications on 100% bio-diesel.

1.2.2 Gasoline

Gasoline engines have the advantage over diesel in being lighter and able to work at

higher rotational speeds and they are the usual choice for fitting in high-performance

sports cars. Continuous development of gasoline engines for over a hundred years has

produced improvements in efficiency and reduced pollution. The carburetor was used on

nearly all road car engines until the 1980s but it was long realised better control of the

fuel/air mixture could be achieved with fuel injection. Indirect fuel injection was first

used in aircraft engines from 1909, in racing car engines from the 1930s, and road cars

from the late 1950s.[14] Gasoline Direct Injection (GDI) is now starting to appear in

production vehicles such as the 2007 (Mark II) BMW Mini. Exhaust gases are also

cleaned up by fitting a catalytic converter into the exhaust system. Clean air legislation in

many of the car industries most important markets have made both catalysts and fuel

injection virtually universal fittings. Most modern gasoline engines also are capable of

running with up to 15% ethanol mixed into the gasoline - older vehicles may have seals

and hoses that can be harmed by ethanol. With a small amount of redesign, gasoline-

powered vehicles can run on ethanol concentrations as high as 85%. 100% ethanol is

used in some parts of the world (such as Brazil), but vehicles must be started on pure

gasoline and switched over to ethanol once the engine is running. Most gasoline engine

cars can also run on LPG with the addition of an LPG tank for fuel storage and

carburetion modifications to add an LPG mixer. LPG produces fewer toxic emissions and

is a popular fuel for fork lift trucks that have to operate inside buildings.

1.2.3 Bio-Fuels

Ethanol, other alcohol fuels (bio-butane) and bio-gasoline have widespread use an

automotive fuel. Most alcohols have less energy per liter than gasoline and are usually

blended with gasoline. Alcohols are used for a variety of reasons - to increase octane, to

improve emissions, and as an alternative to petroleum based fuel, since they can be made

from agricultural crops. Brazil's ethanol program provides about 20% of the nation's

automotive fuel needs, as a result of the mandatory use of E25 blend of gasoline

throughout the country, 3 million cars that operate on pure ethanol, and 6 million dual or

flexible-fuel vehicles sold since 2003 that run on any mix of ethanol and gasoline. The

commercial success of "flex" vehicles, as they are popularly known, have allowed

sugarcane based ethanol fuel to achieve a 50% market share of the gasoline market by

April 2008.

1.2.4 Electric

The first electric cars were built around 1832, well before internal combustion powered

cars appeared. For a period of time electrics were considered superior due to the silent

nature of electric motors compared to the very loud noise of the gasoline engine. This

advantage was removed with Hiram Percy Maxim's invention of the muffler in 1897.

Thereafter internal combustion powered cars had two critical advantages: 1) long range

and 2) high specific energy (far lower weight of petrol fuel versus weight of batteries).

The building of battery electric vehicles that could rival internal combustion models had

to wait for the introduction of modern semiconductor controls and improved batteries.

Because they can deliver a high torque at low revolutions electric cars do not require such

a complex drive train and transmission as internal combustion powered cars. Some post-

2000 electric car designs such as the Venturi Fétish are able to accelerate from 0-60 mph

(96 km/h) in 4.0 seconds with a top speed around 130 mph (210 km/h). Others have a

range of 250 miles (400 km) on the EPA highway cycle requiring 3-1/2 hours to

completely charge. Equivalent fuel efficiency to internal combustion is not well defined

but some press reports give it at around 135 mpg–U.S. (1.74 L/100   km  / 162.1 mpg–imp).

1.2.5 Steam

Steam power, usually using an oil- or gas-heated boiler, was also in use until the 1930s

but had the major disadvantage of being unable to power the car until boiler pressure was

available (although the newer models could achieve this in well under a minute). It has

the advantage of being able to produce very low emissions as the combustion process can

be carefully controlled. Its disadvantages include poor heat efficiency and extensive

requirements for electric auxiliaries.

1.2.6 Air

A compressed air car is an alternative fuel car that uses a motor powered by compressed

air. The car can be powered solely by air, or by air combined (as in a hybrid electric

vehicle) with gasoline/diesel/ethanol or electric plant and regenerative braking. Instead of

mixing fuel with air and burning it to drive pistons with hot expanding gases; compressed

air cars use the expansion of compressed air to drive their pistons. Several prototypes are

available already and scheduled for worldwide sale by the end of 2008. Companies

releasing this type of car include Tata Motors and Motor Development International

(MDI).

1.2.7 Gas turbine

In the 1950s there was a brief interest in using gas turbine engines and several makers

including Rover and Chrysler produced prototypes. In spite of the power units being very

compact, high fuel consumption, severe delay in throttle response, and lack of engine

braking meant no cars reached production.

1.3 Automobiles Type

1.3.1 Car

A car is generally four wheeled motor vehicle for transporting passengers. Most

definitions of the term specify that cars are designed to run primarily on roads, to have

seating for one to eight people, to typically have four wheels, and to be constructed

principally for the transport of people rather than goods.

1.3.2 Truck

A truck is a vehicle for carrying goods and materials. The word "truck" possibly derives

from the Greek "trochos", meaning "wheel." In North America, the big wheels of wagons

were called trucks. When the gasoline-engine driven trucks came into fashion, these were

called "motor trucks." Lorry is a term from the United Kingdom and the Republic of

Ireland, but is only used for the medium and heavy types, i.e. a van, a pickup or a Jeep

would never be regarded as a lorry. Other languages have loanwords based on these

terms, such as the Malay language and the Spanish language in northern Mexico.

Figure 1.1 An Australian prime mover Kenworth and B double trailer combination

1.3.3 Bus

A bus is a large road vehicle designed to carry numerous passengers in addition to the

driver and sometimes a conductor. The name is a neologic version of the Latin omnibus,

which means 'for all'. The full name for a bus is an 'Omnibus Vehicle' - meaning a

'vehicle for all'.

Figure 1.2 A local transit bus

Early bus manufacturing grew out of carriage coachwork builders, and later out of

automobile or truck manufacturing enterprises. Early buses were merely a bus body fitted

to a truck chassis. This body plus chassis approach has continued into modern specialist

manufacturers, although there also exists integral manufacturers of complete bus or coach

products. Specialist builders also build buses for special uses, or modify standard

products. Modern day bus manufacturing combines a number of advanced technologies,

including GPS location, passenger information systems and electronic control, and

increasingly features technology to aid accessibility. Manufacturers are also investigating

alternatives to the traditional combustion engine powered approach, with electric, fuel

cell and hybrid bus technologies. As with the auto-industry, bus manufacturing is

developing from a localized enterprise to increasingly becoming a globalize industry,

with groups of manufacturers forming consortia. As with the car industry, new models

are often exhibited at industry motor shows.

CHAPTER 2

Automobile Engine

2.1 Introduction

All the automobile engines work on the principal of internal combustion engine i.e. an

automobile engine is an internal combustion engine.

2.2 Internal combustion engine

The internal combustion engine is an engine in which the combustion of fuel and an

oxidizer (typically air) occurs in a confined space called a combustion chamber. This

exothermic reaction creates gases at high temperature and pressure, which are permitted

to expand. Internal combustion engines are defined by the useful work that is performed

by the expanding hot gases acting directly to cause the movement of solid parts of the

engine.

Figure 2.1 A colored automobile engine

The term Internal Combustion Engine (ICE) is often used to refer to an engine in which

combustion is intermittent, such as a Wankel engine or a reciprocating piston engine in

which there is controlled movement of pistons, cranks, cams, or rods. However,

continuous combustion engines such as jet engines, most rockets, and many gas turbines

are also classified as types of internal combustion engines. This contrasts with external

combustion engines such as steam engines and Stirling engines that use a separate

combustion chamber to heat a separate working fluid—which then in turn does work, for

example, by moving a piston or a turbine.

2.2.1 Applications

The motion of internal combustion engines is usually performed by the controlled

movement of pistons, cranks, rods, rotors, or even the entire engine itself.

Internal combustion engines are most commonly used for mobile propulsion in vehicles

and portable machinery. In mobile equipment, internal combustion is advantageous since

it can provide high power-to-weight ratios together with excellent fuel energy-density.

Generally using a petroleum called All-Petroleum Internal Combustion Engine Vehicles

or APICEVs, these engines have appeared in transport in almost all automobiles, trucks,

motorcycles, boats, and in a wide variety of aircraft and locomotives.

Internal combustion engines appear in the form of gas turbines as well where a very high

power is required, such as in jet aircraft, helicopters, and large ships. They are also

frequently used for electric generators and by industry.

2.2.2 Operation

Internal combustion engines have 4 basic steps:

Intake :Combustible mixtures are emplaced in the combustion chamber

Compression :The mixtures are placed under pressure

Combustion/Expansion :The mixture is burnt, almost invariably a deflagration,

although a few systems involve detonation. The hot mixture is expanded, pressing

on and moving parts of the engine and performing useful work.

Exhaust :The cooled combustion products are exhausted

Many engines overlap these steps in time; jet engines do all steps simultaneously at

different parts of the engines. Some internal combustion engines have extra steps.

Figure 2.2 A four-stroke cycle (or Otto cycle)

2.2.3 Combustion

All internal combustion engines depend on the exothermic chemical process of

combustion: the reaction of a fuel, typically with oxygen from the air—although other

oxidizers such as nitrous oxide may be employed. The combustion process typically

results in the production of a great quantity of heat, as well as the production of steam

and carbon dioxide and other chemicals at very high temperature; the temperature

reached is determined by the chemical make up of the fuel and oxidizers.

The most common modern fuels are made up of hydrocarbons and are derived mostly

from petroleum. These include the fuels known as diesel fuel, gasoline and petroleum

gas, and the rarer use of propane. Except for the fuel delivery components, most internal

combustion engines that are designed for gasoline use can run on natural gas or liquefied

petroleum gases without major modifications. Liquid and gaseous biofuels, such as

ethanol and bio-diesel (a form of diesel fuel that is produced from crops that yield

triglycerides such as soybean oil), can also be used. Some engines with appropriate

modifications can also run on hydrogen gas.

All internal combustion engines must achieve ignition in their cylinders to create

combustion. Typically engines use either a spark ignition (SI) method or a compression

ignition (CI) system. In the past, other methods using hot tubes or flames have been used.

(a) Gasoline Ignition Process

Gasoline engine ignition systems generally rely on a combination of a lead-acid battery

and an induction coil to provide a high-voltage electrical spark to ignite the air-fuel mix

in the engine's cylinders. This battery is recharged during operation using an electricity-

generating device such as an alternator or generator driven by the engine. Gasoline

engines take in a mixture of air and gasoline and compress to less than 185 psi, then use a

spark plug to ignite the mixture when it is compressed by the piston head in each

cylinder.

(b) Diesel Ignition Process

Diesel engines and HCCI engines rely solely on heat and pressure created by the engine

in its compression process for ignition. The compression level that occurs is usually twice

or more than a gasoline engine. Diesel engines will take in air only, and shortly before

peak compression, a small quantity of diesel fuel is sprayed into the cylinder via a fuel

injector that allows the fuel to instantly ignite. HCCI type engines will take in both air

and fuel but continue to rely on an unaided auto-combustion process, due to higher

pressures and heat. This is also why diesel and HCCI engines are more susceptible to

cold-starting issues, although they will run just as well in cold weather once started. Light

duty diesel engines in automobiles and light trucks employ glow plugs that pre-heat the

combustion chamber just before starting to reduce no-start conditions in cold weather.

Most diesels also have a battery and charging system; nevertheless, this system is

secondary and is added by manufacturers as a luxury for the ease of starting, turning fuel

on and off (which can also be done via a switch or mechanical apparatus), and for

running auxiliary electrical components and accessories. Most new engines rely on

electrical and electronic control systems that also control the combustion process to

increase efficiency and reduce emissions.

2.2.4 Measures of engine performance

Engine types vary greatly in a number of different ways:

Energy efficiency

Fuel/propellant consumption (brake specific fuel consumption for shaft engines,

thrust specific fuel consumption for jet engines)

Power to weight ratio

Thrust to weight ratio

Torque curves (for shaft engines)

(a) Energy Efficiency

Once ignited and burnt, the combustion products—hot gases—have more available

thermal energy than the original compressed fuel-air mixture (which had higher chemical

energy). The available energy is manifested as high temperature and pressure that can be

translated into work by the engine. In a reciprocating engine, the high-pressure gases

inside the cylinders drive the engine's pistons.

Once the available energy has been removed, the remaining hot gases are vented (often

by opening a valve or exposing the exhaust outlet) and this allows the piston to return to

its previous position (top dead center, or TDC). The piston can then proceed to the next

phase of its cycle, which varies between engines. Any heat that isn't translated into work

is normally considered a waste product and is removed from the engine either by an air or

liquid cooling system.

Engine efficiency can be discussed in a number of ways but it usually involves a

comparison of the total chemical energy in the fuels, and the useful energy abstracted

from the fuels in the form of kinetic energy. The most fundamental and abstract

discussion of engine efficiency is the thermodynamic limit for abstracting energy from

the fuel defined by a thermodynamic cycle. The most comprehensive is the empirical fuel

economy of the total engine system for accomplishing a desired task; for example, the

miles per gallon accumulated.

Internal combustion engines are primarily heat engines and as such the phenomenon that

limits their efficiency is described by thermodynamic cycles. None of these cycles exceed

the limit defined by the Carnot cycle which states that the overall efficiency is dictated by

the difference between the lower and upper operating temperatures of the engine. A

terrestrial engine is usually and fundamentally limited by the upper thermal stability

derived from the material used to make up the engine. All metals and alloys eventually

melt or decompose and there is significant researching into ceramic materials that can be

made with higher thermal stabilities and desirable structural properties. Higher thermal

stability allows for greater temperature difference between the lower and upper operating

temperatures—thus greater thermodynamic efficiency.

The thermodynamic limits assume that the engine is operating in ideal conditions.

Frictionless world ideal gases are perfect insulators and operation at infinite time. The

real world is substantially more complex and all the complexities reduce the efficiency.

In addition, real engines run best at specific loads and rates as described by their power

curve. For example, a car cruising on a highway is usually operating significantly below

its ideal load, because the engine is designed for the higher loads desired for rapid

acceleration. The applications of engines are used as contributed drag on the total system

reducing overall efficiency, such as wind resistance designs for vehicles. These and many

other losses result in an engines' real-world fuel economy that is usually measured in the

units of miles per gallon (or kilometers per liter) for automobiles. The miles in, "MPG"

represents a meaningful amount of work and the volume of hydrocarbon implies standard

energy content.

Most steel engines have a thermodynamic limit of 37%. Even when aided with

turbochargers and stock efficiency aids, most engines retain an average efficiency of

about 18%-20%.

(b) Measures of fuel/propellant efficiency

For stationary and shaft engines including propeller engines, fuel consumption is

measured by calculating the brake specific fuel consumption which measures the number

of pounds of fuel that is needed to generate an hours' worth of horsepower-energy. In

metric units, the number of grams of fuel needed to generate a kWh of energy is

calculated.

For internal combustion engines in the form of jet engines, the power output varies

drastically with airspeed and a less variable measure is used: thrust specific fuel

consumption (TSFC), which is the number of pounds of propellant that is needed to

generate impulses that measure a pound an hour. In metric units, the number of grams of

propellant needed to generate an impulse that measures one kilo Newton per second.

2.2.5 Air and noise pollution

Internal combustion engines such as reciprocating internal combustion engines produce

air pollution emissions, due to incomplete combustion of carbonaceous fuel. The main

derivatives of the process are carbon dioxide CO2, water and some soot—also called

particulate matter (PM). The effects of inhaling particulate matter have been studied in

humans and animals and include asthma, lung cancer, cardiovascular issues, and

premature death. There are however some additional products of the combustion process

that includes nitrogen oxides and sulfur and some un-combusted hydrocarbons,

depending on the operating conditions and the fuel-air ratio.

Not all of the fuel will be completely consumed by the combustion process; a small

amount of fuel will be present after combustion, some of which can react to form

oxygenates, such as formaldehyde or acetaldehyde, or hydrocarbons not initially present

in the fuel mixture. The primary causes of this is the need to operate near the

stoichiometric ratio for gasoline engines in order to achieve combustion and the resulting

"quench" of the flame by the relatively cool cylinder walls, otherwise the fuel would burn

more completely in excess air. When running at lower speeds, quenching is commonly

observed in diesel (compression ignition) engines that run on natural gas. It reduces the

efficiency and increases knocking, sometimes causing the engine to stall. Increasing the

amount of air in the engine reduces the amount of the first two pollutants, but tends to

encourage the oxygen and nitrogen in the air to combine to produce Nitrogen Oxides

(NOx) that has been demonstrated to be hazardous to both plant and animal health.

Further chemicals released are Benzene and 1,3-Butadiene that are also particularly

harmful; and not all of the fuel burns up completely, so Carbon Monoxide (CO) is also

produced.

Finally, significant contributions to noise pollution are made by internal combustion

engines. Automobile and truck traffic operating on highways and street systems produce

noise, as do aircraft flights due to jet noise, particularly supersonic-capable aircraft.

Rocket engines create the most intense noise.

2.2.6 Parts

For a four-stroke engine, key parts of the engine include the crankshaft (purple),

connecting rod (orange), one or more camshafts (red and blue), and valves. For a two-

stroke engine, there may simply be an exhaust outlet and fuel inlet instead of a valve

system. In both types of engines there are one or more cylinders (grey and green), and for

each cylinder there is a spark plug (darker-grey, gasoline engines only), a piston (yellow),

and a crankpin (purple). A single sweep of the cylinder by the piston in an upward or

downward motion is known as a stroke. The downward stroke that occurs directly after

the air-fuel mix passes from the carburetor or fuel injector to the cylinder, where it is

ignited. This is also known as a power stroke.

Figure 2.3 An illustration of several key components in a typical four-stroke engine

A Wankel engine has a triangular rotor that orbits in an epitrochoidal chamber around an

eccentric shaft. The four phases of operation (intake, compression, power, and exhaust)

take place in what is effectively a moving, variable-volume chamber.

A Bourke Engine uses a pair of pistons integrated to a Scotch Yoke that transmits

reciprocating force through a specially designed bearing assembly to turn a crank

mechanism. The intake, compression, power, and exhaust occur in each stroke.

2.2.7 Engine cycle

(a) Two-stroke

Engines based on the two-stroke cycle use two strokes (one up, one down) for every

power stroke. Since there are no dedicated intake or exhaust strokes, alternative methods

must be used to scavenge the cylinders. The most common method in spark-ignition two-

strokes is to use the downward motion of the piston to pressurize fresh charge in the

crankcase, which is then blown through the cylinder through ports in the cylinder walls.

Spark-ignition two-strokes are small and light for their power output and mechanically

very simple; however, they are also generally less efficient and more polluting than their

four-stroke counterparts. In terms of power per cubic centimetre, a single-cylinder small

motor application like a two-stroke engine produces much more power than an equivalent

four-stroke engine due to the enormous advantage of having one power stroke for every

360 degrees of crankshaft rotation (compared to 720 degrees in a 4 stroke motor).

Small displacement, crankcase-scavenged two-stroke engines have been less fuel-

efficient than other types of engines when the fuel is mixed with the air prior to

scavenging allowing some of it to escape out of the exhaust port. Modern designs (Sarich

and Paggio) use air-assisted fuel injection which avoids this loss, and are more efficient

than comparably sized four-stroke engines. Fuel injection is essential for a modern two-

stroke engine in order to meet ever more stringent emission standards.

Research continues into improving many aspects of two-stroke motors including direct

fuel injection, amongst other things. The initial results have produced motors that are

much cleaner burning than their traditional counterparts. Two-stroke engines are widely

used in snowmobiles, lawnmowers, weed-whackers, chain saws, jet skis, mopeds,

outboard motors, and many motorcycles.

The largest compression-ignition engines are two-strokes and are used in some

locomotives and large ships. These particular engines use forced induction to scavenge

the cylinders; an example of this type of motor is the Wartsila-Sulzer turbocharged two-

stroke diesel as used in large container ships. It is the most efficient and powerful engine

in the world with over 50% thermal efficiency. For comparison, the most efficient small

four-stroke motors are around 43% thermal efficiency (SAE 900648); size is an

advantage for efficiency due to the increase in the ratio of volume to area.

(b) Four-stroke

Engines based on the four-stroke or Otto cycle have one power stroke for every four

strokes (up-down-up-down) and are used in cars, larger boats, some motorcycles, and

many light aircraft. They are generally quieter, more efficient, and larger than their two-

stroke counterparts. There are a number of variations of these cycles, most notably the

Atkinson and Miller cycles. Most truck and automotive diesel engines use a four-stroke

cycle, but with a compression heating ignition system. This variation is called the diesel

cycle. The steps involved here are:

1. Intake stroke: Air and vaporized fuel are drawn in.

2. Compression stroke: Fuel vapor and air are compressed and ignited.

3. Combustion stroke: Fuel combusts and piston is pushed downwards.

4. Exhaust stroke: Exhaust is driven out. During the 1st, 2nd, and 4th stroke the

piston is relying on power and the momentum generated by the other pistons. In

that case, a four cylinder engine would be less powerful than a six or eight

cylinder engine.

(c) IRIS Engine

The IRIS design replaces the piston and cylinder architecture of conventional engines

with a mechanism called the Internally Radiating Impulse Structure or "IRIS". In an IRIS

combustion chamber, a number of inverted segments of a circle or "chordons" interact to

create a continuously sealed chamber of variable volume. Instead of elongating during

combustion—as a traditional engine does—the IRIS engines' chamber expands in

diameter. This innovation may significantly enhance fuel efficiency by reducing waste

heat and increasing the amount of surface area the engine has available to produce torque.

The IRIS design was recently patented and may eventually yield engines that are smaller,

lighter, and more efficient than traditional piston-based systems.

(d) Bourke engine

In this engine, two opposed cylinders are linked to the crank by a Scotch yoke. The

Scotch yoke mechanism prevents side thrust which in turn prevents any piston slap

allowing the operation as a detonation or "explosion" engine. This also greatly reduces

friction between pistons and cylinder walls. The Bourke engine uses fewer moving parts

and has to overcome less friction than conventional crank and slider engines with poppet

valves, however no independent testing of this engine has ever expanded any of these

claims.

(e) Controlled Combustion Engine

These are also cylinder-based engines, which may be one or two-stroke but instead of a

crankshaft and piston rods, use two gear-connected, counterrotating concentric cams to

convert reciprocating motion into rotary movement. These cams practically cancel out

sideward forces that would otherwise be exerted on the cylinders by the pistons greatly

improving mechanical efficiency. The number of lobes of the cams (always an odd

number not less than 3) determines the piston travel versus the torque delivered. In this

engine, there are two cylinders that are 180 degrees apart for each pair of counterrotating

cams. For single-stroke versions, there are as many cycles per cylinder pair as there are

lobes on each cam and twice as many for two-stroke engines.

(f) Wankel

The Wankel engine (rotary engine) does not have piston strokes so it is more properly

called a, "four-phase"—rather than a four-stroke engine. It operates with the same

separation of phases as the four-stroke engine with the phases taking place in separate

locations in the engine. While it is true that three power strokes typically occur per rotor

revolution due to the 3/1 revolution ratio of the rotor to the eccentric shaft, only one

power stroke per shaft revolution actually occurs; this engine provides three power

'strokes' per revolution per rotor giving it a greater power-to-weight ratio than piston

engines. This type of engine is most notably used in the current Mazda RX-8, the earlier

RX-7, and other models.

(g) Gas turbine

Gas turbine cycle engines employ a continuous combustion system where compression,

combustion, and expansion occur simultaneously at different places in the engine—

giving continuous power.

A gas turbine is a rotary machine similar in principle to a steam turbine and it consists of

three main components: a compressor, a combustion chamber, and a turbine. The air after

being compressed in the compressor is heated by burning fuel in it. About two-thirds of

the heated air combined with the products of combustion is expanded in a turbine

resulting in work output which is used to drive the compressor. The rest (about one-third)

is available as useful work output.

(h) Jet engine

Jet engines take a large volume of hot gas from a combustion process (typically a gas

turbine, but rocket forms of jet propulsion often use solid or liquid propellants) and feed

it through a nozzle which accelerates the jet to high speed. As the jet accelerates through

the nozzle, this creates thrust and in turn does useful work.

(I) Disused methods

In some old noncom pressing internal combustion engines; in the first part of the piston

down stroke, a fuel-air mixture was sucked or blown in, and in the rest of the piston down

stroke, the inlet valve closed and the fuel-air mixture fired. In the piston upstroke, the

exhaust valve was open. This was an attempt at imitating the way a piston steam engine

works, and since the explosive mixture was not compressed, the heat and pressure

generated by combustion was much less causing lower overall efficiency.

2.2.8 Engine configuration

Internal combustion engines can be classified by their configuration which affects their

physical size and smoothness, with smoother engines producing less vibration. Common

configurations include the straight or inline configuration, the more compact V

configuration, and the wider but smoother flat or boxer configuration. Aircraft engines

can also adopt a radial configuration which allows more effective cooling. More unusual

configurations such as the H, U, X, and W have also been used.

Multiple crankshaft configurations do not necessarily need a cylinder head at all because

it can instead have a piston at each end of the cylinder called an opposed piston design.

This design was used in the Junkers Jumo 205 diesel aircraft engine, using at either end

of a single bank of cylinders with two crankshafts, and most remarkably in the Napier

Deltic diesel engines. These used three crankshafts to serve three banks of double-ended

cylinders arranged in an equilateral triangle with the crankshafts at the corners. It was

also used in single-bank locomotive engines, and continues to be used for marine

engines, both for propulsion and for auxiliary generators. The Gnome Rotary engine,

used in several early aircraft, had a stationary crankshaft and a bank of radially arranged

cylinders rotating around it.

2.2.9 Engine capacity

An engines' capacity is the displacement or swept volume by the pistons of the engine. It

is generally measured in liters (L) or cubic inches (c.i.d. or cu in or in³) for larger engines,

and cubic centimeters (abbreviated cc) for smaller engines. Engines with greater

capacities are usually more powerful and provide greater torque at lower rpm, but also

consume more fuel. Apart from designing an engine with more cylinders, there are two

ways to increase an engines' capacity. The first is to lengthen the stroke: the second is to

increase the pistons' diameter (See also: Stroke ratio). In either case, it may be necessary

to make further adjustments to the fuel intake of the engine to ensure optimal

performance.

2.2.10 Common components

(a) Combustion chambers

Internal combustion engines can contain any number of combustion chambers

(cylinders), with numbers between one and twelve being common, though as many as 36

(Lycoming R-7755) have been used. Having more cylinders in an engine yields two

potential benefits: first, the engine can have a larger displacement with smaller individual

reciprocating masses, that is, the mass of each piston can be less thus making a smoother-

running engine since the engine tends to vibrate as a result of the pistons moving up and

down: secondly, with a greater displacement and more pistons, more fuel can be

combusted and there can be more combustion events (more power strokes) in a given

period of time. This means that such an engine can generate more torque than a similar

engine with fewer cylinders.

The downside to having more pistons is that the engine will tend to weigh more and

generate more internal friction as the greater number of pistons rub against the inside of

their cylinders. This tends to decrease fuel efficiency and robs the engine of some of its

power. For high-performance gasoline engines using current materials and technology—

such as the engines found in modern automobiles, there seems to be a break-point around

10 or 12 cylinders after which the addition of cylinders becomes an overall detriment to

performance and efficiency. Although, exceptions such as the W16 engine from

Volkswagen exist.

Most car engines have four to eight cylinders with some high performance cars

having ten, twelve—or even sixteen, and some very small cars and trucks having

two or three. In previous years, some quite large cars such as the DKW and Saab

92, had two-cylinder or two-stroke engines.

Radial aircraft engines (now obsolete) had from three to 28 cylinders; an example

is the Pratt & Whitney R-4360. A row contains an odd number of cylinders so an

even number indicates a two- or four-row engine. The largest of these was the

Lycoming R-7755 with 36 cylinders (four rows of nine cylinders), but it did not

enter production.

Motorcycles commonly have from one to four cylinders, with a few high

performance models having six; although, some 'novelties' exist with 8, 10, or 12.

Snowmobiles usually have two cylinders. Some larger but not necessarily high-

performance touring machines, have four.

Small portable appliances such as chainsaws, generators, and domestic lawn

mowers most commonly have one cylinder, but two-cylinder chainsaws exist.

(b) Ignition system

An internal combustion engine can be classified by its ignition system. Today most

engines use an electrical or compression heating system for ignition.

(1) Spark: The mixture is ignited by an electrical spark from a spark plug—the

timing of which is very precisely controlled. Almost all gasoline engines are of this type,

but not diesel engines.

(2) Compression: Ignition comes from the heat derived from oxidation and the

mechanical compression of the air or mixture. The vast majority of compression ignition

engines are diesels in which the fuel is mixed with the air after the air has reached

ignition temperature. In this case, the timing comes from the fuel injection system. Very

small model engines for which simplicity is more important than fuel costs, use special

fuels to control ignition timing.

(3) Ignition Timing: For reciprocating engines, the point in the cycle at which the

fuel-oxidizer mixture is ignited has a direct effect on the efficiency and output of the ICE.

The thermodynamics of the idealized Carnot heat engine tells us that an ICE is most

efficient if most of the burning takes place at a high temperature, resulting from

compression—near top dead center. The speed of the flame front is directly affected by

the compression ratio, fuel mixture temperature, and octane or cetane rating of the

fuel. Leaner mixtures and lower mixture pressures burn more slowly requiring more

advanced ignition timing. It is important to have combustion spread by a thermal flame

front (deflagration), not by a shock wave. Combustion propagation by a shock wave is

called detonation and, in engines, is also known as pinging or knocking.

So at least in gasoline-burning engines, ignition timing is largely a compromise between

an earlier "advanced" spark—which gives greater efficiency with high octane fuel—and a

later "retarded" spark that avoids detonation with the fuel used. For this reason, high-

performance diesel automobile proponents such as, Gale Banks, believe that

© Fuel systems

A device used to deliver fuel to the internal combustion engine. Fuels burn faster and

more completely when they have lots of surface area in contact with oxygen. In order for

an engine to work efficiently the fuel must be vaporized into the incoming air in what is

commonly referred to as a fuel-air mixture. There are two commonly used methods of

vaporizing fuel into the air: one is the carburetor: the other is fuel injection.

(1) Carburetor: Often for simpler reciprocating engines, a carburetor is used to supply

fuel into the cylinder. However, exact control of the correct amount of fuel supplied to

the engine is impossible. Carburetors are the current most widespread fuel mixing device

used in lawn mowers and other small engine applications. Prior to the mid-1980s,

carburetors were also common in automobiles.

(2) Fuel injection: Larger gasoline engines used in automobiles have mostly moved to

fuel injection systems (see Gasoline Direct Injection). Diesel engines always use fuel

injection because it is the fuel system that controls the ignition timing. Other internal

combustion engines like jet engines use burners and rocket engines use various different

ideas including impinging jets, gas/liquid shear, preburners, and many other ideas.

(d) Oxidizer-Air inlet system

Some engines such as solid rockets have oxidisers already within the combustion

chamber but in most cases for combustion to occur, a continuous supply of oxidiser must

be supplied to the combustion chamber.

(1) Natural aspirated engines: When air is used with piston engines it can simply suck

it in as the piston increases the volume of the chamber. However, this gives a maximum

of 1 atmosphere of pressure difference across the inlet valves, and at high engine speeds

the resulting airflow can limit potential power output.

(2) Superchargers: A supercharger is a "forced induction" system which uses a

compressor powered by the shaft of the engine which forces air through the valves of the

engine to achieve higher flow. When these systems are employed the maximum absolute

pressure at the inlet valve is typically around 2 times atmospheric pressure or more.

(e) Piston engine valves

In piston engines, the valves are grouped into 'inlet valves' which admit the entrance of

fuel and air and 'outlet valves' which allow the exhaust gases to escape. Each valve opens

once per cycle and the ones that are subject to extreme accelerations are held closed by

springs that are typically opened by rods running on a camshaft rotating with the engines'

crankshaft.

(f) Control valves

Continuous combustion engines—as well as piston engines—usually have valves that

open and close to admit the fuel and/or air at the startup and shutdown. Some valves

feather to adjust the flow to control power or engine speed as well.

(g) Exhaust systems

Internal combustion engines have to manage the exhaust of the cooled combustion gas

from the engine. The exhaust system frequently contains devices to control pollution,

both chemical and noise pollution. In addition, for cyclic combustion engines the exhaust

system is frequently tuned to improve emptying of the combustion chamber.

For jet propulsion internal combustion engines, the 'exhaust system' takes the form of a

high velocity nozzle, which generates thrust for the engine and forms a colimated jet of

gas that gives the engine its name.

(h) Cooling systems

Combustion generates a great deal of heat, and some of this transfers to the walls of the

engine. Failure will occur if the body of the engine is allowed to reach too high a

temperature, either the engine will physically fail, or any lubricants used will degrade to

the point that they no longer protect the engine.

Cooling systems usually employ air or liquid cooling while some very hot engines using

radiative cooling (especially some Rocket engines). Some high altitude rocket engines

use ablative cooling where the walls gradually erode in a controlled fashion.

(i) Piston

A piston is a component of reciprocating engines. It is located in a cylinder and is made

gas-tight by piston rings. Its purpose is to transfer force from expanding gas in the

cylinder to the crankshaft via a piston rod and/or connecting rod. In some engines, the

piston also acts as a valve by covering and uncovering ports in the cylinder wall.

(f) Crankshafts

Very many reciprocating internal combustion engines end up turning a shaft. This means

that the linear motion of a piston must be turned into a rotation. This is typically achieved

by a crankshaft.

Figure 2.4 A crankshaft for a 4 cylinder engine

(g) Flywheels

Flywheels are found in most reciprocating engines as a way to smooth out the power

delivery over each rotation of the crank. Without it, many engines would stall at low

engine speeds.

(h) Starter systems

Internal combustion engines require systems to put them into a operational mode that can

be sustained. For piston engines this can involve a starter motor; small portable engines

can be started with a manual crank or even pull cords.

(i) Lubrication Systems

Internal combustions engines require lubrication in operation to allow moving parts to

slide smoothly over each other. Insufficient lubrication will subject the engine to rapid

wear and ultimately, it may even seize up entirely.

Several different types of lubrication systems are used. Simple two-stroke engines are

lubricated by oil mixed into the fuel or injected into the induction stream as a spray. Early

slow-speed stationary and marine engines were lubricated by gravity from small

chambers similar to those used on steam engines at the time—with an engine tender

refilling these as needed. As engines were adapted for automotive and aircraft use, the

need for a high power-to-weight ratio led to increased speeds, higher temperatures, and

greater pressure on bearings which in turn required pressure-lubrication for crank

bearings and connecting-rod journals. This was provided either by a direct lubrication

from a pump, or indirectly by a jet of oil directed at pickup cups on the connecting rod

ends which had the advantage of providing higher pressures as the engine speed

increased

CHAPTER 3

A Mechanical Spring

3.1 Introduction to a spring

A spring is a flexible elastic object used to store mechanical energy. Springs are usually

made out of hardened steel. Small springs can be wound from pre-hardened stock, while

larger ones are made from annealed steel and hardened after fabrication. Some non-

ferrous metals are also used including phosphor bronze and titanium for parts requiring

corrosion resistance and beryllium copper for springs carrying electrical current (because

of its low electrical resistance).

Figure 3.1 Helical or coil springs designed for tension

The rate of a spring is the change in the force it exerts, divided by the change in

deflection of the spring. That is, it is the gradient of the force versus deflection curve. An

extension or compression spring has units of force divided by distance, for example lbf/in

or N/m. Torsion springs have units of force multiplied by distance divided by angle, such

as Nm/rad or ft lbf/degree. The inverse of spring rate is compliance that is if a spring has

a rate of 10 N/mm; it has a compliance of 0.1 mm/N. The stiffness (or rate) of springs in

parallel is additive, as is the compliance of springs in series.

3.2 Types of spring

(a) Depending on load they may be classified as:

Tension/Extension spring

Compression spring

Torsional spring

In tension/extension and compression there is axial load. On the other hand in the

torsional spring there is torsional force.

Figure 3.2 A spiral hair spring

(b) Depending on spring material it can be classified as:

Wire/Coil spring

Flat spring

(c) The most common types of spring are:

Cantilever spring - a spring which is fixed only at one end.

Coil spring or helical spring - a spring (made by winding a wire around a

cylinder) and the conical spring - these are types of torsion spring, because the

wire itself is twisted when the spring is compressed or stretched.

Compression springs are designed to become shorter when loaded. Their turns are

not touching in the unloaded position, and they need no attachment points.

A volute spring is a compression spring in the form of a cone, designed so that

under compression the coils are not forced against each other, thus permitting

longer travel.

Tension springs are designed to become longer under load. Their turns are

normally touching in the unloaded position, and they have a hook, eye or some

other means of attachment at each end.

Figure 3.3 Vertical volute springs of Stuart tank

Hairspring or balance spring - a delicate spiral torsion spring used in watches,

galvanometers, and places where electricity must be carried to partially-rotating

devices such as steering wheels without hindering the rotation.

Leaf spring - a flat springy seat, used in vehicle suspensions, electrical switches,

bows.

Figure 3.4 Leaf spring on a truck

V-spring - used in antique firearm mechanisms such as the wheellock, flintlock

and percussion cap locks.

Belleville washer or Belleville spring - a disc shaped spring commonly used to

apply tension to a bolt (and also in the initiation mechanism of pressure-activated

landmines).

Gas spring - a volume of gas which is compressed.

Ideal Spring - the notional spring used in physics: it has no weight, mass, or

damping losses.

Mainspring - a spiral ribbon shaped spring used as a power source in watches,

clocks, music boxes, windup toys, and mechanically powered flashlights.

Torsion spring - any spring designed to be twisted rather than compressed or

extended. It used in torsion bar vehicle suspension systems.

Negator spring - a thin flat metal band that is coiled similar to a tape rule. This

type of spring produces a constant force throughout a long displacement.

Wave spring - a high stiffness spring

3.3 Torsion spring

A torsion spring is a spring that works by torsion or twisting; that is, a flexible elastic

object that stores mechanical energy when it is twisted. The amount of force (actually

torque) it exerts is proportional to the amount it is twisted. A torsion spring is often made

from a wire, ribbon, or bar of metal or rubber, while more delicate ones are made of silk,

glass, or quartz fibers.

(a) Torsion coefficient

As long as they are not twisted beyond their elastic limit, torsion springs obey an angular

form of Hooke's law. It is analogous to the spring constant of a linear spring.

(b) Uses

Torsion bars (or sway bars) are heavy torsion springs used to support automobile

suspension components, allowing those components (which indirectly support the

wheels) to move in response to rough roads while allowing a smooth ride in the

vehicle.

The torsion pendulum used in torsion pendulum clocks is a wheel-shaped weight

suspended from its center by a wire torsion spring. The weight rotates about the

axis of the spring, twisting it, instead of swinging like an ordinary pendulum. The

force of the spring reverses the direction of rotation, so the wheel oscillates back

and forth, driven at the top by the clock's gears.

The torsion catapult is a medieval siege engine invented by the ancient Greeks. It

uses a torsion spring consisting of twisted ropes to swing an arm that throws a

heavy missile at the enemy with great force.

The balance spring or hairspring in mechanical watches is a fine spiral-shaped

torsion spring that pushes the balance wheel back toward its center position as it

rotates back and forth. The balance wheel and spring function similarly to the

torsion pendulum above in keeping time for the watch.

3.4 Leaf spring

It is originally called laminated or carriage spring, a leaf spring is a simple form of

spring, commonly used for the suspension in wheeled vehicles. It is also one of the oldest

forms of springing, dating back to medieval times.

Sometimes referred to as a semi-elliptical spring or cart spring, it takes the form of a

slender arc-shaped length of spring steel of rectangular cross-section. The center of the

arc provides location for the axle, while tie holes are provided at either end for attaching

to the vehicle body. For very heavy vehicles, a leaf spring can be made from several

leaves stacked on top of each other in several layers, often with progressively shorter

leaves. Leaf springs can serve locating and to some extent damping as well as springing

functions.

Figure 3.6 A leaf spring is connected to the frame through a shackle

A leaf spring can either be attached directly to the frame at both ends or attached directly

at one end, usually the front, with the other end attached through a shackle, a short

swinging arm. The shackle takes up the tendency of the leaf spring to elongate when

compressed and thus makes for softer springiness.

3.5 Coil spring

A Coil spring, also known as a helical spring, is a mechanical device, which is typically

used to store energy and subsequently release it, to absorb shock, or to maintain a force

between contacting surfaces. They are made of an elastic material formed into the shape

of a helix which returns to its natural length when unloaded.

Figure 3.7 A compression coil spring

Figure 3.8 A tension coil spring

Coil springs are a special type of torsion spring, the material of the spring acts in torsion

when the spring is compressed or extended. The two usual types of coil spring are:

Tension coil springs which are designed to resist stretching. They usually have a

hook or eye form at each end for attachment.

Compression coil springs are designed to resist being compressed. A typical use

for compression coil springs is in car suspension systems.

3.6 Hooke's law

Most springs (not stretched or compressed beyond the elastic limit) obey Hooke's law,

which states that the force with which the spring pushes back is linearly proportional to

the distance from its equilibrium length.

Coil springs and other common springs typically obey Hooke's law. There are useful

springs that don't: springs based on beam bending can for example produce forces that

vary nonlinearly with displacement.

There are also linear springs which don't follow Hooke's law: a Negator spring (the

spring that a self retracting tape measure uses) provides a constant force.

3.7 Theory

In classical physics, a spring can be seen as a device that stores potential energy by

straining the bonds between the atoms of an elastic material. Hooke's law of elasticity

states that the extension of an elastic rod (its distended length minus its relaxed length) is

linearly proportional to its tension, the force used to stretch it. Similarly, the contraction

(negative extension) is proportional to the compression (negative tension). This law

actually holds only approximately, and only when the deformation (extension or

contraction) is small compared to the rod's overall length. For deformations beyond the

elastic limit, atomic bonds get broken or rearranged, and a spring may snap, buckle, or

permanently deform. Many materials have no clearly defined elastic limit, and Hooke's

law can not be meaningfully applied to these materials. Hooke's law is a mathematical

consequence of the fact that the potential energy of the rod is a minimum when it has its

relaxed length. Any smooth function of one variable approximates a quadratic function

when examined near enough to its minimum point; and therefore the force, which is the

derivative of energy with respect to displacement, will approximate a linear function.

3.8 Uses

Vehicle suspension

Slinky

Pogo Stick

Dashpot

CHAPTER 4

Designing of Shock Absorber

4.1 Design of Shock Absorber for automobile

The research project is carried out for Maruti-Van car, where two shock absorbers are

fixed on the front face of vehicle. Figure 4.1 shows the model of project in details. Shock

absorbers work on the principle of spring energy power and simply classified as

hydraulic compression close coil spring. The project model is designed for Maruti-Van

car.

4.1 Specification of components used

Shock absorbers:

No.: Two

Capacity: Depends on the vehicle type (for Maruti-Van, 500 Kg each)

Type: Hydraulic

Principle of operation: Spring energy

Weight:

Depend on vehicle type (for Maruti-Van, 30 Kg)

Cost:

30,000/- for Maruti-Van

4.2 Principle of operation

Both hydraulic springs are fixed on the front face of the vehicle as shown in figure 4.1. A

frame is also fixed on the shock absorbers. When vehicle will get collision with another

vehicle, an impact loading will apply to the frame and transfer to shock absorbers and

damage will be defiantly very less to the vehicle and also to the passengers.

The system works on the principal of momentum transfer ( Newton's laws of motion).

Newton's laws of motion describe the acceleration of massive particles. In modern

language, the laws may be stated as:

First law:

It is possible to select a set of reference frames, called inertial reference frames,

observed from which a particle moves without any change in velocity if no net

force acts on it. This law is often simplified into the sentence "A particle will stay

at rest or continue at a constant velocity unless acted upon by an external

unbalanced net force."

Second law:

Observed from an inertial reference frame, the net force on a particle is

proportional to the time rate of change of its linear momentum: F = d (mv) / dt.

Momentum mv is the product of mass and velocity. Force and momentum are

vector quantities and the resultant force is found from all the forces present by

vector addition. This law is often stated as "F = ma: the net force on an object is

equal to the mass of the object multiplied by its acceleration."

Third law:

Whenever a particle A exerts a force on another particle B, B simultaneously

exerts a force on A with the same magnitude in the opposite direction. The strong

form of the law further postulates that these two forces act along the same line.

This law is often simplified into the sentence "Every action has an equal and

opposite reaction."

4.3 Spring design

Two open coil helical spring of high stiffness is used in model to absorb the impact force

on the face of vehicle.

We know that:δ= (64 WR3n) / (Cd4)

Where:δ= Deflection of spring (30 cm in present case)W= Axial Load i.e. force required to compress the spring

R= Mean radius of spring coil (25 cm)

n= No. of turns (10)

C= Modulus of rigidity (1000 GPa) i.e. material has very high stiffness

d= Diameter of spring wire (5 cm)

By using the above data for the spring and above equation, W will be:

W=187500 N

Energy stored by one spring = W X δ /2

=28125 N-m

i.e. during the collision one spring can store the 28125 N-m energy or energy stored by

two spring will be 56250 N-m energy.

Now suppose during the collision the mass of two vehicles is 1000 Kg, and the relative

velocity is V m/s then kinetic energy will be generated:

K.E. = M X V2/2

Where:

M is mass of vehicles in Kg

V is relative velocity of vehicle

If whole kinetic energy is stored as spring energy then:

M X V2/2=56250 N-m

Since M=1000 Kg

i.e. V=10.61 m/s or 38.183 Km/hr

Hence we can say if two small vehicles are moving with a relative velocity of 38.18

Km/hr, then during collision whole kinetic energy will store as spring energy by this

arrangement and there will be no loss to the passengers and vehicle.

If both vehicles have this system of shock absorber then there will be no loss during the

collision even they have the relative velocity of 76.36 km/hr.

Vehicle can be made more safer by using more springs or shock absorber.

4.4 Designing of the driver’s seat

The design of the driver’s seat is also modified. When vehicle will get collision with

another vehicle, an impact loading will apply to the shock absorbers and driver’s seat will

move to down direction by the amount of deflection in spring. This arrangement is made

by leavers in model.

The linkage mechanism is used to get this arrangement.

This will help to driver with front loading and glass. The steering effect at this moment

will also be negligible, since driver will move to downwards direction. This arrangement

will helpful to save the life of driver during the collision of small vehicle with heavy

vehicles.

CHAPTER 5

Application, Advantages & Disadvantages

5.1 Applications

The system can be incorporate in any type of motor vehicle such as:

In small cars

In heavy loading vehicle like trucks and buses

The system can be useful for following type of car crash also.

.

Figure 5.1 A car crash

5.2 Advantages

1. Passenger safety will increase.

2. Pregnant women can continue journey.

3. As car safety is generally designed for normal sized adults. Safety features that

could save an adult can actually cause more damage to a child than if the feature

was not there.

4. Toddlers over 1 year old and between 10 and 20 kg (20 and 40 pounds) can make

journey.

5. Design is safe for young children also.

6. Teenage drivers will drive the vehicle very safely.

7. This system can wear up to 1000 Kg of impact loading. The capacity can be

increase by using more powerful shock absorbers.

8. Driver will be safe during the sudden crash or collision by modifying the seat

design.

9. The leaver of seat is connected to shock absorbers; movement of seat will also

depend on the displacement of frame (shock absorbers).

10. This system will turn out highly safe driving for single person, who drives the

vehicle.

11. Car safety will also increase, since there will be less damage after crashing.

5.2 Disadvantages

1. Cost will increase slightly.

2. Weight of vehicle will increase slightly.

3. System required maintenance also.

4. Looks of vehicle will change.

CHAPTER 6

Future scope and conclusion

6.1 Future scope

The arrangement is designed for small car in this project work, but this arrangement can

be widely use in future for heavy vehicles also by making some small modifications in

current project.

6.2 Conclusion

A car accident is a road traffic incident which usually involves one road vehicle colliding

with, another vehicle, another road user, or a stationary roadside object, and which may

result in injury or property damage.

Frontal impacts are most common accidents in the world of automobile, and this system

will be very useful and helpful to mange these type of accidents, since, an inbuilt shock

absorber system on front face of a car can be easily attached to all currently manufacture

automobile companies.

The system works on the principal of spring energy and design with the help of two

hydraulic open coil compression springs.

This arrangement has many advantages such as saving of life and vehicle saving. With

the help of this system the driving of vehicles will be easy especially for ladies.

Arrangement is also very useful for heavy loading vehicles and a single person can go on

a fearless long drive. Single and both shock absorbers can work simultaneously at a

single time also i.e. arrangement will be useful to frontal and as well side collision also.

References:

1. www.howstuffworks.com .

2. www.google.com .

3. www.bharatwirerope.com .

4. www.wikipedia.com.

5. www.rope-making.com.

6. www.vikrantropes.com.

7. www.finolex.com.

8. www.techsourcer.com.

9. www.engineering.com.

10. www.globalspec.com.

11. www.irational.org.

12. www.safetysling.com.

13. www.aboutconstruction.org.

14. www.encarta.com.

15. www.britannica.com .

16. A Textbook of Machine Design by R.S.Khurmi & J.K.Gupta.

17. A Textbook of Automobile Engineering by Dr. Kirpal Singh.