AUTOMATIC GEAR SHIFTING MECHANISM

FOR TWO WHEELER

A PROJECT REPORT

Submitted by

In partial fulfillment for the award of the degree

Of

IN

MECHANICAL ENGINEERING

ANNA UNIVERSITY: CHENNAI 600 025

NOV/DEC 2012

ANNA UNIVERSITY: CHENNAI 600 025

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BONAFIDE CERTIFICATE

Certified that this project report “AUTOMATIC GEAR SHIFTING

MECHANISM FOR TWO WHEELER”Is the bonafide work of “]

” Whocarried out the project work under my supervision.

SIGNATURE SIGNATURE

]

Submitted for the project viva-voce held at Tagore Institute of Engineering and Technology

on ……………..

………………………… ………………………..

Internal Examiner External Examiner

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ACKNOWLEDGEMENT

Weexpressour sincere thanks to our beloved philanthropic

MANAGEMENTofTagore institute of Engineering and Technology trust for having

provided with necessary resources to complete this project.

We extend our extreme gratitude alwaysto our beloved visionary Principal

and thank him for his motivation and moral support towards us to complete this

project.

We express our deep sense of gratitude and profound thanks to Head of

Mechanical Engineering Department,for her remarkable guidance which was an

inspiration to us.

We have immense pleasure to express our hearty thanks to our beloved

Project Co-, Assistant Professor of Mechanical Engineering Department, for her

unflinching support throughout our project .

We have privileged to thank our beloved supervisor

.,Assistant Professor of Mechanical Engineering Department, for her

enlightening thoughts and meticulous guidance that helped us in doing our project.

We also express our gratefulness to our parents, faculty members and friends

for their affectionate blessings and loving cooperation at all stages of this academic

venture.

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ABSTRACT

This project titled as “Automatic Gear Shifting Mechanism for Two wheelers”. This

is a fabrication and implementation project. The project provides solution for gear shifting for

the Bikes. The passenger bikes that now ply on the road have transmission of manual type of

gear changing. The manual type of transmission is preferred for the perfect performance

without a loss in power but a compromise for comfortless.

In this type manual system of power transmission there is easiness of gear shifting but

there is a definite loss of power and mileage. The main objective of this project is to create a

mechanism to reduce the inconvenience caused when changing gears in the bikes. The gear

shifting is achieved by a simple modification to the gear box. This is a versatile pack, simple

and can be fitted to any bikes. Moreover the whole set up is small and requires a very small

space. This can sure be a standard fitment if proper marketing strategy is carried out.

The main purpose of this project is used to automate the gear changing mechanism in

vehicles. In this project we are doing the gear changing mechanism using with the help of

sensors & actuators. This is very useful for the gear changing mechanism in automobile

vehicles.

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CHAPTER-I

INTRODUCTION

The paper deals with the real time project, “Automatic Gear Shifting Mechanism for

Two wheelers” which was done in the academic year 2012- 2013. This project is aimed at

giving driver the convenience for gear shifting& better performance. The bike with this

project will have a stepper motor, microcontroller &sensors.

The clutch operation may or may not be put in the bike depending on the user. The power for

gear shifting is got from stepper motor. The power for stepper motor is from the battery. So a

bike with a battery fitment can be easily adaptable to this project. The project has been started

as a concept and it requires a lot more work to be done to put in a bike.

PROBLEM DEFINITION:

Whenever a project is carried out there is a reason behind it. The existing cars now

pose some problems for the drivers. In the Manual Transmission cars the main problem for

the drivers is the gear shifting. But the engineering concept behind this type of transmission

paves way for higher power transmission efficiency. More over the mileage of the car and life

is also more. These cars do not give much of comfort ness for the drivers in the terms of

using the gear lever and the clutch. Also it occupies a major area in the cabin resulting in the

space congestion. These are the problems in the Manual Transmission cars.

In the Automatic Transmission type of cars, the gear shifting is easy. We just have to

select the drive band, which is already preset. This selection may be either of lever type or a

set of buttons. This is easy for the drivers as they don’t have to use clutch during gear shift.

But there is a compromise for power transmission and mileage. As the gear selection is by a

fluid, power is required to drive it, so the engine performance is reduced. So the problem

here is mileage drop, power loss and also it is costly.

The need of the hour, combining the position of both MT and AT a mechanism has to

be created for better mileage and comfortable gear shifting. This is the objective of the

project. So a car with this project provides ease of gear shift as in AT without a compromise

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in mileage as in MT. the cost of the project is less as it requires a minor alteration in the gear

box.

TRANSMISSION

Gearbox" redirects here. For the video game developer, see Gearbox Software.

Five-speed + reverse gearbox from the 1600 Volkswagen Golf (2009).

A machine consists of a power source and a power transmission system, which provides

controlled application of the power. Merriam-Webster defines transmission as an assembly of

parts including the speed-changing gears and the propeller shaft by which the power is

transmitted from an engine to a live axle.[1] Often transmission refers simply to

the gearbox that uses gears and gear trains to providespeed and torque conversions from a

rotating power source to another device.[2][3]

In British English, the term transmission refers to the whole drive train, including clutch,

gearbox, prop shaft (for rear-wheel drive), differential, and final drive shafts. In American

English, however, the distinction is made that a gearbox is any device which converts speed

and torque, whereas a transmission is a type of gearbox that can be “shifted” to dynamically

change the speed-torque ratio such as in a vehicle.

The most common use is in motor vehicles, where the transmission adapts the output of

the internal combustion engine to the drive wheels. Such engines need to operate at a

relatively high rotational speed, which is inappropriate for starting, stopping, and slower

travel. The transmission reduces the higher engine speed to the slower wheel speed,

increasing torque in the process. Transmissions are also used on pedal bicycles, fixed

machines, and anywhere else where rotational speed and torque needs to be adapted.

Often, a transmission will have multiple gear ratios (or simply “gears”), with the ability to

switch between them as speed varies. This switching may be done manually (by the

operator), or automatically. Directional (forward and reverse) control may also be provided.

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Single-ratio transmissions also exist, which simply change the speed and torque (and

sometimes direction) of motor output.

In motor vehicles, the transmission will generally be connected to the crankshaft of the

engine. The output of the transmission is transmitted via driveshaft to one or

more differentials, which in turn, drive the wheels. While a differential may also provide gear

reduction, its primary purpose is to permit the wheels at either end of an axle to rotate at

different speeds (essential to avoid wheel slippage on turns) as it changes the direction of

rotation.

Conventional gear/belt transmissions are not the only mechanism for speed/torque adaptation.

Alternative mechanisms include torque converters and power transformation (for

example, diesel-electric transmission and hydraulic drive system). Hybrid configurations also

exist.

EXPLANATION

Early transmissions included the right-angle drives and other gearing in windmills, horse-

powered devices, and steam engines, in support of pumping, milling, and hoisting.

Most modern gearboxes are used to increase torque while reducing the speed of a prime

mover output shaft (e.g. a motor crankshaft). This means that the output shaft of a gearbox

will rotate at a slower rate than the input shaft, and this reduction in speed will produce

a mechanical advantage, causing an increase in torque. A gearbox can be set up to do the

opposite and provide an increase in shaft speed with a reduction of torque. Some of the

simplest gearboxes merely change the physical direction in which power is transmitted.

Many typical automobile transmissions include the ability to select one of several

different gear ratios. In this case, most of the gear ratios (often simply called "gears") are

used to slow down the output speed of the engine and increase torque. However, the highest

gears may be "overdrive" types that increase the output speed.

Manual

Manual transmission come in two basic types:

a simple but rugged sliding-mesh or unsynchronized / non-synchronous system, where

straight-cut spur gear sets are spinning freely, and must be synchronized by the operator

matching engine revs to road speed, to avoid noisy and damaging "gear clash",

and the now common constant-mesh gearboxes which can include non-synchronised,

or synchronized / synchromesh systems, where typically diagonal cut helical (or

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sometimes either straight-cut, or double-helical) gear sets are constantly "meshed"

together, and a dog clutch is used for changing gears. On synchromesh boxes, friction

cones or "synchro-rings" are used in addition to the dog clutch to closely match the

rotational speeds of the two sides of the (declutched) transmission before making a full

mechanical engagement.

The former type was standard in many vintage cars (alongside e.g. epicyclic and multi-clutch

systems) before the development of constant-mesh manuals and hydraulic-epicyclic

automatics, older heavy-duty trucks, and can still be found in use in some agricultural

equipment. The latter is the modern standard for on- and off-road transport manual and semi-

automatic transmission, although it may be found in many forms; e.g., non-synchronised

straight-cut in racetrack or super-heavy-duty applications, non-synchro helical in the majority

of heavy trucks and motorcycles and in certain classic cars (e.g. the Fiat 500), and partly or

fully synchronised helical in almost all modern manual-shift passenger cars and light trucks.

Manual transmissions are the most common type outside North America and Australia. They

are cheaper, lighter, usually give better performance, and fuel efficiency (although automatic

transmissions with torque converter lockup and advanced electronic controls can provide

similar results). It is customary for new drivers to learn, and be tested, on a car with a manual

gear change. In Malaysia and Denmark all cars used for testing (and because of that, virtually

all those used for instruction as well) have a manual transmission. In Japan, the

Philippines, Germany,Poland, Italy, Israel, the Netherlands, Belgium, New

Zealand, Austria, Bulgaria, the UK,[6][7] Ireland,[7] Sweden, Norway, Estonia, France, Spain, Switzerland, the Australian states of Victoria,[8]Western Australia and Queensland, Finland, Lithuania and the Czech Republic, a test pass

using an automatic car does not entitle the driver to use a manual car on the public road; a test

with a manual car is required.[citation needed] Manual transmissions are much more common than

automatic transmissions in Asia, Africa, South America and Europe.

Manual transmissions can include both synchronized and unsynchronized gearing. For

example, reverse gear is usually unsynchronised, as the drive is only expected to engage it

when the vehicle is at a standstill. Many older (up to 1970s) cars also lacked syncro on first

gear (for various reasons - cost, typically "shorter" overall gearing, engines typically having

more low-end torque, the extreme wear which would be placed on a frequently used 1st gear

synchroniser...), meaning it also could only be used for moving away from a stop unless the

driver became adept at double-declutching and had a particular need to regularly downshift

into the lowest gear.

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Some manual transmissions have an extremely low ratio for first gear, which is referred to as

a "creeper gear" or "granny gear". Such gears are usually not synchronized. This feature is

common on pickup trucks tailored to trailer-towing, farming, or construction-site work.

During normal on-road use, the truck is usually driven without using the creeper gear at all,

and second gear is used from a standing start. Some off-road vehicles, most particularly the

Willys Jeep and its descendents, also had transmissions with "granny first"s either as standard

or an option, but this function is now more often provided for by a low-range transfer

gearbox attached to a normal fully synchronised transmission.

Non-synchronous

There are commercial applications engineered with designs taking into account that the gear

shifting will be done by an experienced operator. They are a manual transmission, but are

known as non-synchronized transmissions. Dependent on country of operation, many local,

regional, and national laws govern the operation of these types of vehicles (see Commercial

Driver's License). This class may include commercial, military, agricultural, or engineering

vehicles. Some of these may use combinations of types for multi-purpose functions. An

example would be a power take-off(PTO) gear. The non-synchronous transmission type

requires an understanding of gear range, torque, engine power, and multi-functional clutch

and shifter functions. Also see Double-clutching, and Clutch-brake sections of the main

article.

Automatic

Most modern North American and Australian and some European and Japanese cars have

an automatic transmission that will select an appropriate gear ratio without any operator

intervention. They primarily use hydraulics to select gears, depending on pressure exerted by

fluid within the transmission assembly. Rather than using a clutch to engage the transmission,

a fluid flywheel, or torque converter is placed in between the engine and transmission. It is

possible for the driver to control the number of gears in use or select reverse, though precise

control of which gear is in use may or may not be possible.

Automatic transmissions are easy to use. However, in the past, automatic transmissions of

this type have had a number of problems; they were complex and expensive, sometimes had

reliability problems (which sometimes caused more expenses in repair), have often been less

fuel-efficient than their manual counterparts (due to "slippage" in the torque converter), and

their shift time was slower than a manual making them uncompetitive for racing. With the

advancement of modern automatic transmissions this has changed.[citation needed]

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Attempts to improve the fuel efficiency of automatic transmissions include the use of torque

converters which lock up beyond a certain speed, or in the higher gear ratios, eliminating

power loss, and overdrive gears which automatically actuate above certain speeds; in older

transmissions both technologies could sometimes become intrusive, when conditions are such

that they repeatedly cut in and out as speed and such load factors as grade or wind vary

slightly. Current computerized transmissions possess very complex programming to both

maximize fuel efficiency and eliminate any intrusiveness. This is due mainly to electronic

advances rather than mechanical ones although improvements in CVT technology and the use

of automatic clutches have also helped. The 2012 model of the Honda Jazz sold in the UK

actually claims marginally better fuel consumption for the CVT version than the manual

version.

For certain applications, the slippage inherent in automatic transmissions can be

advantageous; for instance, in drag racing, the automatic transmission allows the car to be

stopped with the engine at a high rpm (the "stall speed") to allow for a very quick launch

when the brakes are released; in fact, a common modification is to increase the stall speed of

the transmission. This is even more advantageous for turbocharged engines, where the

turbocharger needs to be kept spinning at high rpm by a large flow of exhaust in order to keep

the boost pressure up and eliminate the turbo lag that occurs when the engine is idling and the

throttle is suddenly opened.

Semi-automatic

A hybrid form of transmission where the an integrated control system handles manipulation

of the clutch automatically, but the driver can still - and may be required to - take manual

control of gear selection. This is sometimes called a "clutchless manual," or "automated

manual" transmission. Many of these transmissions allow the driver to fully delegate gear

shifting choice to the control system, which then effectively acts as if it was a regular

automatic transmission. They are generally designed using manual transmission "internals",

and when used in passenger cars, have synchromesh operated helical constant mesh gear sets.

Early semi-automatic systems used a variety of mechanical and hydraulic systems - including

centrifugal clutches, torque converters, electro-mechanical (and even electrostatic) and

servo/solenoid controlled clutches - and control schemes - automatic declutching when

moving the gearstick, pre-selector controls, centrifugal clutches with drum-sequential shift

requiring the driver to lift the throttle for a successful shift, etc. - and some were little more

than regular lock-up torque converter automatics with manual gear selection.

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Most modern implementations, however, tend to be standard or slightly modified manual

transmissions (and very occasionally modified automatics, even including a few cases

of CVTs with "fake" fixed gear ratios), with servo-controlled clutching and shifting under

command of the central engine computer. These are intended to be a combined replacement

option both for more expensive and less efficient "normal" automatic systems, and for drivers

who prefer manual shift but are no longer able to operate a clutch, and users are encouraged

to leave the shift lever in fully automatic "Drive" most of the time, only engaging manual-

sequential mode for sporty driving or when otherwise strictly necessary.

Specific types of this transmission include: Easytronic, Tiptronic and Geartronic, as well as

the systems used as standard in all ICE-powered Smart-MCC vehicles, and on geared step-

through scooters such as the Honda Super Cub or Suzuki Address.

A dual-clutch transmission uses two sets of internals which are alternately used, each with its

own clutch, so that a "gearchange" actually only consists of one clutch engaging as the other

disengages, making for a supposedly "seamless" shift with no break in (or jarring reuptake

of) power transmission. Each clutch's attached shaft carries half of the total input gear

complement (with a shared output shaft), including synchronised dog clutch systems that pre-

select which of its set of ratios is most likely to be needed at the next shift, under command of

a computerised control system.

Specific types of this transmission include: Direct-Shift Gearbox.

There are also sequential transmissions which use the rotation of a drum to switch gears,

much like those of a typical fully manual motorcycle.[9] These can be designed with a manual

or automatic clutch system, and may be found both in automobiles (particularly track and

rally racing cars), motorcycles (typically light "step-thru" type city utility bikes, e.g. the

Honda Super Cub) and quadbikes (often with a separately engaged reversing gear), the latter

two normally using a scooter-style centrifugal clutch.

MOTOR CYCLE TRANSMISSION

A motorcycle transmission is a transmission created specifically for motorcycle applications.

They may also be found in use on other light vehicles such as motor tricycles and quadbikes,

offroad buggies, mowers and other utility vehicles, microcars, and even some superlight

sports cars.

CLUTCH

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The clutch in a manual-shift motorcycle transmission is typically an arrangement of

plates stacked in alternating fashion, one geared on the inside to the engine and the next

geared on the outside to the transmission input shaft. Whether wet (rotating in engine oil) or

dry, the plates are squeezed together by a spring, causing friction build up between the plates

until they rotate as a single unit, driving the transmission directly. A lever on the handlebar

exploits mechanical advantage through a cable or hydraulic arrangement to release the clutch

spring, allowing the engine to freewheel with respect to the transmission.

Automatic and semi-automatics typically use a centrifugal clutch which operates in a

different fashion. At idle, the engine is disconnected from the gearbox input shaft, allowing

both it and the bike to freewheel (unlike torque converter automatics, there is no "idle creep"

with a properly adjusted centrifugal clutch). As the throttle is opened and engine speed rises,

counterweights attached to movable inner friction surfaces (connected to the engine shaft)

within the clutch assembly are thrown gradually further outwards, until they start to make

contact with the inside of the outer housing (connected to the gearbox shaft) and transmit an

increasing amount of engine power. The effective "bite point" is found automatically by

equilibrium where the power being transmitted through the (still-slipping) clutch is equal to

what the engine can provide. This allows relatively fast full-throttle takeoffs (with the clutch

adjusted so the engine will be turning near its maximum-torque rpm) without the engine

slowing or bogging down, as well as more relaxed starts and low-speed manoeuvres at lower

throttle settings and rpms.

Above a certain engine speed - once the bike is properly in motion, so the gearbox input shaft

is also rotating quickly and so allowing the engine to accelerate further by way of clutch slip -

the outward pressure of the weighted friction plates is sufficient that the clutch will enter full

lock-up, the same as a conventional plate-clutch with a fully released lever or pedal. After

this, there is no clutch slip, and the engine is locked to and providing all of its available

power to the transmission; engine rpm is now dependent on the road speed and the current

gear ratio (under either user control in a semi-auto, or reliant on road speed (and sometimes

load/throttle position) in a CVT setup). In a typical CVT, the gear ratio will be chosen so the

engine can reach and maintain its maximum-power speed as soon as possible (or at least,

when at full throttle, in a partially load-dependent system), but in a semi-auto the rider is

responsible for this choice, and they can ride around all day in top gear (or first) if they so

prefer. Also, once the engine is turning fast enough to lock the clutch, it will stay fully

engaged until the RPMs fall below that critical point again, even if the throttle is fully

released. Below the lock-up point, partially or fully releasing the throttle can lead to the RPM

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falling off rapidly, thanks to the feedback loop of lower engine speed meaning less friction

pressure. This toggle-like mode of operation can lead to certain characteristic centrifugal-

clutch-automatic behaviour, such as being able to freewheel rapidly downhill from a

standstill, with engine braking only being triggered by turning the throttle briefly (and not

then cancellable without braking to quite a slow, gear-dependent pace), and lockup triggering

at a lower speed with full versus minimal throttle.

CONSRUCTION

Pre-unit construction, also called separate construction, is a motorcycle engine architecture

where the engine and gearbox are separate casings. In unit construction the engine and

gearbox share a single housing.

In many modern designs, the engine sits in front of the gearbox. From a sprocket on one side

of the crankshaft, a chain will drive the clutch, which can often be found behind a large

circular cover on one side of the gearbox. The clutch is connected to the gearbox input shaft.

For motorcycles with chain drive, the gearbox output shaft is typically connected to the

sprocket which drives the final drive chain.

Most manual motorcycle gearboxes have "constant mesh" gears which are always mated but

may rotate freely on a shaft until locked by a toothed sliding collar or "dog clutch". Since the

gears are always rotating and can only be accessed sequentially, synchromesh is not generally

needed. To save space, both shafts may contain a mixture of fixed and free-spinning gears,

with some gears built into the sliding parts.

Comparison to other automated transmissions

The automatic transmission is fully automatic and one does not need to change gears at all,

which happens at the discretion of the computer in the car whereas in the semi-automatic

transmission one can up-shift or down-shift without pressing the clutch. The gear can be

engaged in manual mode wherein one can move it up and down to change the gears or one

could operate the paddle shifters, just behind the steering wheel to perform the same

operation. Many modern automated transmissions can also operate in the same manner as a

conventional type of automatic transmission by allowing the transmission's computer to

automatically change gear if, for example, the driver were redlining the engine. The ability to

shift gears manually, often via paddle shifters, can also be found on certain automatic

transmissions (manumatics such as Tiptronic) and continuous variable transmissions (CVTs)

(such as Lineartronic).

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Despite superficial similarity to other automated transmissions, automated transmissions

differ significantly in internal operation and driver's "feel" from manumatics and CVTs. A

manumatic, like a standard automatic transmission, uses a torque converter instead

of clutch to manage the link between the transmission and the engine, while a CVT uses a

belt instead of a fixed number of gears. A semi-automatic transmission offers a more direct

connection between the engine and wheels than a manumatic and is preferred in high

performance driving applications, while a manumatic is often preferred for street use because

its fluid coupling makes it easier for the transmission to consistently perform smooth shifts,[1] and CVTs are generally found in gasoline-electric hybrid engine applications.

Typically semi-automatic transmissions are more expensive than manumatics and CVTs, for

instance BMW's 7-speed Double Clutch Transmission is a $3900 CAD upgrade to the

standard 6-speed manual, while the 6-speed Steptronic Automatic was only a $1600 CAD

option.[2] In a given market, very few models have two choices of automated transmission; for

instance the BMW 645Ci/650i (E63/64) (standard 6-speed manual) had an optional 6-speed

automatic "Steptronic" or 7-speed Getrag SMG III single-clutch semi-automatic transmission

until after the 2008 model year, when the SMG III was dropped. [3] Many sport luxury

manufacturers such as BMW offer the manumatic for their mainstream lineup (such as the

BMW 328i and BMW 535i) and the semi-automatic for their high-performance models (the

BMW M3 and BMW M5).[2]

The automated transmission may be derived from a conventional automatic; for

instance Mercedes-Benz's AMG Speedshift MCT automated transmission is based on the 7G-

Tronic manumatic, however the latter's torque converter has been replaced with a wet, multi-

plate launch clutch.[4] Other automated transmissions have their roots in a conventional

manual; the SMG II drivelogic (found in the BMW M3 (E46) is a Getrag 6-speed manual

transmission, but with an electrohydraulically actuated clutch pedal, similar to an Formula

One style transmission.[5][6][7] The most common type of semi-automatic transmission in

recent years has been the dual clutch type, since single-clutch types such as the SMG III have

been criticized for their general lack of smoothness in everyday driving (although being

responsive at the track)

OPERATION

In standard mass-production automobiles, the gear lever appears similar to manual shifts,

except that the gear stick only moves forward and backward to shift into higher and lower

gears, instead of the traditional H-pattern. The Bugatti Veyron uses this approach for its

seven-speed transmission. InFormula One, the system is adapted to fit onto the steering

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wheel in the form of two paddles; depressing the right paddle shifts into a higher gear, while

depressing the left paddle shifts into a lower one. Numerous road cars have inherited the

same mechanism.

Hall effect sensors sense the direction of requested shift, and this input, together with a sensor

in the gear box which senses the current speed and gear selected, feeds into a central

processing unit. This unit then determines the optimal timing and torque required for a

smooth clutch engagement, based on input from these two sensors as well as other factors,

such as engine rotation, the Electronic Stability Control, air

conditioner and dashboardinstruments.

The central processing unit powers a hydro-mechanical unit to either engage or disengage the

clutch, which is kept in close synchronization with the gear-shifting action the driver has

started. In some cases, the hydro-mechanical unit contains a servomotor coupled to a gear

arrangement for a linearactuator, which uses brake fluid from the braking system to impel a

hydraulic cylinder to move the main clutch actuator. In other cases, the clutch actuator may

be completely electric.

The power of the system lies in the fact that electronic equipment can react much faster and

more precisely than a human, and takes advantage of the precision of electronic signals to

allow a complete clutch operation without the intervention of the driver.

For the needs of parking, reversing and neutralizing the transmission, the driver must engage

both paddles at once; after this has been accomplished, the car will prompt for one of the

three options.

The clutch is really only needed to start the car. For a quicker upshift, the engine power can

be cut, and the collar disengaged until the engine drops to the correct speed for the next gear.

For the teeth of the collar to slide into the teeth of the rings, both the speed and position must

match. This needs sensors to measure not only the speed, but the positions of the teeth, and

the throttle may need to be opened softer or harder. The even-faster shifting techniques

like powershifting require a heavier gearbox or clutch or even a dual clutch transmission.

ELECTROHYDURALIC MANUAL TRANSMMISION

Electrohydraulic manual transmission is a type of semi-automatic transmission system, which

uses an automated clutch unlike conventional manual transmissions where the driver operates

the clutch. The clutch is controlled by electronic computers and hydraulics. To change gears,

the driver selects the desired gear with the transmission shift lever, and the system

automatically operates the clutch and throttle to match revs and engage the clutch again.

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Also, many such transmissions operate in sequential mode where the driver can only upshift

or downshift by one gear at a time.

Depending on the implementation, some computer-controlled electrohydraulic manual

transmissions will automatically shift gears at the right points (like an automatic

transmission), while others require the driver to manually select the gear even when the

engine is at the redline. Despite superficial similarity, clutchless manual transmission differ

significantly in internal operation and driver's 'feel' from manumatics, the latter of which is

an automatic transmission (automatics use a torque converter instead of clutch to manage the

link between the engine and the transmission) with ability to signal shifts manually.

DESIGN OF PROJECT:

The project is done as a table top on the FIAT car’s gear box. The project design

comprises of designing the following parts,

1. Hydraulic circuit

2. Electronic circuit

3. Mechanical components

HYDRAULIC CIRCUIT:

Hydraulic motion is selected for gear shifting owing to its large load acceptance and

ease of adaptability in the car. Also the gear shift should be quick. The basic components

design is explained in detail.

CYLINDER DESIGN:

Load required to move the selector rod or to change the gear F=30 Kg

Pressure built in the compressor unit P=10 bar

To find:

Cylinder dimensions D,L=?

1. Cylinder diameter D=? P=F/A

(10*105)*(/4)*D2 = 30*9.81

D=0.0194 m = 20 mm

2. Cylinder length L =? Cylinder length L= Stroke Length+ Piston thickness+ Clearance

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L= 30+10+7 = 47 mm L=47mm

Cylinder diameter= 20mm Cylinder length= 47mm

SELECTION OF PUMP:

Selection of pump is based on following characteristics:

1. Select the actuator that is appropriate based on loads encountered.

2. Determine the flow rate requirements. This involves the calculation of the flow rate

necessary to drive the actuator to move the load through a specified distance within the

given time.

3. Determine the pump speed and select the prime mover. This, together with the flow rate

calculation, determines the pump size

4. Select the pump based on application

5. Select the system pressure. These involves in with the actuator size and magnitude of the

resistive force produced by the external load on the system. Also involved here is the total

amount of power to be delivered by the pump.

6. Select the reservoir and associated plumping, including piping, valving, hydraulic

cylinders, motors and other miscellaneous components.

7. Calculate the overall cost of the system.

8. Consider factors such as noise levels, horse power loss, need for a heat exchanger due to

heat generated, pump wear, scheduled maintenance service to provide a desired life of the

total system.

The above characteristics are satisfied by the GEAR OIL PUMP and the following data are

obtained from measurement,

Do =75 mm Di =50 mm W= 25 mm N=1440 rpm

1. Flow rate Q= (/4)*(Do2-Di2)*W*N

= (/4)*(0.0752-0.0502)*0.050*1440

= 0.0883 m3/S = 0.00147 m3/min = 1.47 Ltrs/min

2. Power required = Pressure*Flow rate= (10*105)*0.0883 = 88.3 kw

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9

6

/

5

/

7

2 3 4

1 1

8

10

11

SELECTION OF RESERVIOR:

1. Reservoir Capacity= 2.5 to 3 Times of Pump flow

= 3*1.47

= 4.41 Ltrs

=4 Ltrs

2. Size of the copper tube =6 mm(for transmitting hydraulic fluid to valves)

HYDRAULIC CIRCUIT DIAGRAM:

Hydraulic circuit diagram of the project

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C

Sole1

B 1

12 V VVV

V

C

Sole1

LS2

12 V VVVV

1. Reservoir. 7. Cylinder piston assembly

2. Pump. 8. Limit Switch

3. Clutch 9. Gear Box

4. Engine 10. Gear selector rod

5. Inlet Solenoid Valve 11. Spring

6. Outlet Solenoid Valve

ELECTRONIC CIRCUIT:

The electronic circuit is used for governing the hydraulic operation. For this purpose

we have used two solenoid valves (inlet and outlet) for each gear to be shifted. The supply

voltage is from battery which is 12V. there will be six buttons 1, 2, 3, 4, R, N for gear

shifting. Each actuates the gear corresponding when pressed.

The diagram below shows the electronic circuit for various operation of the gear

shifter.

i. Engaging first gear

ii. Maintaining gear position

iii. Releasing gear-neutral position

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Sole2

B N

12 V VVVV

Sole1

12 V VVVVC

Sole2

iv. Gear changing

MECHANICAL COMPONENTS:

The main mechanical component for the project is the spring. The spring is used to

counter balance the force exerted by the piston. Moreover it is useful in the return motion of

the gear selector rod during gear disengagement. Presence of spring on the gear selector rod

helps in the quick action that is required during the gear shift.

DESIGN OF SPRINGS:

We have formula for deflection Y = 8PD3n/Gd4

Where,

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Y=deflection of spring=1.5 Cm

P=load acting on the spring=30 Kg

D=Diameter of spring=3.5 Cm

d= Diameter of spring coil=0.4 Cm

G=modulus of elasticity of spring material=2*105 N/mm2

N=no of coils in the spring=?

No of coils in the spring,

n=YGd4/8PD3

= 1.5*2*105*0.44*100/(8*30*9.81*3.53)

= 8 coils

WORKING PRINCIPLE:

The main driving force for the gear shifting is by the hydraulic fluid. The gear

shifting along with the clutch operation works with the pressing of buttons. On pressing the

button corresponding to the gear, three operations take place,

1. Engine rotation

2. Clutch engagement

3. Pump rotation

When the car is switched on the engine rotates, on pressing the button clutch

engages. Now electromagnetic clutch engages the pump. Due to the pump rotation the

hydraulic fluid is pumped from reservoir to the inlet solenoid valve. Through this valve the

fluid pushes the piston in the cylinder. This motion causes the gear shifter rod to engage the

gear which is fitted to the piston. In order to avoid slippage of gear a limit switch is used to

sense the position of selector rod and cut off the supply.

To bring the car to neutral position we press the N button. Now the outlet solenoid

valve energizes so the fluid in the cylinder rushes back to the sump with the aid of spring

tension. If the next higher gear has to be selected, the same operation takes place on pressing

the next button.

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CURRENT STATUS:

Presently we have done this project as a table top working model. This consists of

various parts which are listed below.

1) FIAT Gearbox

2) TOYOTA Power steering compressor

3) Motor for driving the compressor

4) Electro magnetic clutch

5) Tank or reservoir for storing the hydraulic fluid

6) Valves for controlling the flow of hydraulic fluid

7) Limit switch to cut off the supply

8) Hydraulic cylinder and piston assembly

9) Copper tubes for transportation of fluid

10)Fluid Hoses

11)Base structure for holding the gearbox and motor arrangement

The current model is a simple one which is actuated by a stick switch governing the

gear selection. This set up works good for two gears. In the future there are plans to

incorporate the clutch action in the set up by using the electronic clutch.

WORKING PRINCIPLE

A method of controlling a gear change of an automobile, said automobile comprising an internal combustion engine.

An automatic transmission connected to an output rotation shaft of said engine so as to transmit the rotational output of said engine to drive wheels of said automobile through any selected one of a plurality of gear ratios.

A load device selectively connectable to said output rotation shaft of said engine via selectively-connecting means for generating a gear change control signal for selecting one of said gear ratios of said

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automatic transmission in accordance with one of operational conditions of said automobile and said engine said method comprising the steps of controlling said selectively-connecting means when said gear change signal-generating means generates the control signal for shifting up the gear in said automatic transmission, in such a manner that said selectively-connecting means connects said load device to said output rotation shaft of said engine.

Battery is giving the microcontroller unit. The proximity sensor is used to detect the wheel speed and this signal is given to the microcontroller unit. The 1st gear is done by manually press the button and the succeeding gears all are down automatically by the microcontroller unit.

The two electro-magnetic coils are fixed to the gear shaft of the two ends. One is used to shift the gear in upward direction. Another one is used to shift the gear in downward direction. These two coil is operated depends upon the speed of the vehicle this is automatically done with the help of microcontroller unit c programming language.

fig. 1.1 MICRO-CONTROLLER BASED AUTOMATIC ELECTRO-MAGNETIC GEAR SHIFTING SYSTEM

LIST OF MATERIALS

Sl. No.PARTS

Qty. Material

i. Frame Stand 1 Mild Steel

ii. Battery 1 Lead Acid

iii. Electro magnetic coil 2 Coil

iv. Bearing with Bearing Cap 1 M.S

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v. Engine 1 75 Cc

vi Chain with Sprocket 1 M.S

viii. Connecting Tube 1 meter Plastic

ix. Bolt and Nut - M.S

x Wheel Arrangement 1 -

Xi Microcontroller Unit 1 Electronics

ELECTRO MAGNETIC COIL

fig.1.2 ELECTRO MAGNETIC COIL

The key to understanding the role of permanent magnet’s gear shifting lies in the general issue of biasing. Consider the simplest magnetic as shown in the figure, but omit the lower electromagnet. By omitting the finite permeability of the iron, the current in the coil controls the flux density.

fig.1.3 Proximity_Sensors

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MICROCONTROLLER UNITIn our project Atmega 16 Is the microcontroller unit.

Features

• High-performance, Low-power AVR® 8-bit Microcontroller

• Advanced RISC Architecture

– 131 Powerful Instructions – Most Single-clock Cycle Execution

– 32 x 8 General Purpose Working Registers

– Fully Static Operation

– Up to 16 MIPS Throughput at 16 MHz

– On-chip 2-cycle Multiplier

• Nonvolatile Program and Data Memories

– 16K Bytes of In-System Self-Programmable Flash

Endurance: 10,000 Write/Erase Cycles

– Optional Boot Code Section with Independent Lock Bits

In-System Programming by On-chip Boot Program

True Read-While-Write Operation

– 512 Bytes EEPROM

Endurance: 100,000 Write/Erase Cycles

– 1K Byte Internal SRAM

– Programming Lock for Software Security

• JTAG (IEEE std. 1149.1 Compliant) Interface

– Boundary-scan Capabilities According to the JTAG Standard

– Extensive On-chip Debug Support

– Programming of Flash, EEPROM, Fuses, and Lock Bits through the JTAG Interface

• Peripheral Features

– Two 8-bit Timer/Counters with Separate Prescalers and Compare Modes

– One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture

Mode

– Real Time Counter with Separate Oscillator

– Four PWM Channels

– 8-channel, 10-bit ADC

8 Single-ended Channels

7 Differential Channels in TQFP Package Only

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2 Differential Channels with Programmable Gain at 1x, 10x, or 200x

– Byte-oriented Two-wire Serial Interface

– Programmable Serial USART

– Master/Slave SPI Serial Interface

– Programmable Watchdog Timer with Separate On-chip Oscillator

– On-chip Analog Comparator

• Special Microcontroller Features

– Power-on Reset and Programmable Brown-out Detection

– Internal Calibrated RC Oscillator

– External and Internal Interrupt Sources

– Six Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, Standby

and Extended Standby

• I/O and Packages

– 32 Programmable I/O Lines

– 40-pin PDIP, 44-lead TQFP, and 44-pad MLF

• Operating Voltages

– 2.7 - 5.5V for ATmega16L

– 4.5 - 5.5V for ATmega16

• Speed Grades

– 0 - 8 MHz for ATmega16L

– 0 - 16 MHz for ATmega16

SPECIFICATION OF FOUR STROKE PETROL ENGINE:

Type : Four strokes

Cooling System : Air Cooled

Bore/Stroke : 50 x 50 mm

Piston Displacement : 98.2 cc

Compression Ratio : 6.6: 1

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Maximum Torque : 0.98 kg-m at 5,500RPM

fig.1.4 FOUR STROKES PETROL ENGINE

ADVANTAGES

It requires simple maintenance cares

The safety system for automobile.

Checking and cleaning are easy, because of the main parts are screwed.

Easy to Handle.

Low cost automation Project

Repairing is easy.

Replacement of parts is easy.

APPLICATIONS

It is very much useful for Car Owners & Auto-garages.

Thus it can be useful for the two wheeler application.

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CONCLUSION

This project work has provided us an excellent opportunity and experience, to use our

limited knowledge. We gained a lot of practical knowledge regarding, planning, purchasing,

assembling and machining while doing this project work. We feel that the project work is a

good solution to bridge the gates between institution and industries.

We are proud that we have completed the work with the limited time successfully.

The AUTOMATIC ELECTRO-MAGNETIC GEAR SHIFTING SYSTEM is working with

satisfactory conditions. We are able to understand the difficulties in maintaining the

tolerances and also quality. We have done to our ability and skill making maximum use of

available facilities.

In conclusion remarks of our project work, let us add a few more lines about our

impression project work. Thus we have developed a “AUTOMATIC ELECTRO-

MAGNETIC GEAR SHIFTING SYSTEM” which helps to know how to achieve low cost

automation. The application of electro-magnetic coil produces smooth operation. By using

more techniques, they can be modified and developed according to the applications.

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