Imperial International Journal of Eco-friendly ...

Imperial International Journal of Eco-friendly TechnologiesVol. - 1, Issue-2 (2017), pp.61-73

IIJET

RESEARCH REPORT ON ECOFRIENDLYVEHICLES

V.ANIL KUMAR*, CH.RAMA KRISHNA**, CH.AMARNATH***,HARSHAVARDHAN REDDY M****, V.S.V.V.RAJ AKHIL*****

* [email protected], **[email protected],***[email protected],****[email protected],*****[email protected]

The fuel consumption for the human need has increasedenormously from last 2-3 decades and due to this, there is amassive increase in pollution. And also, the increase in fuelprices will ultimately affect the livelihood of human race.To overcome this problem and also to give humanconveniences, hybrid systems have been developed, whichwill not only decrease the fuel consumption but also Eco-friendly.In our project while manufacturing a hybrid vehicle whichwill run simultaneously on IC engine as well as the electricmotor, Power will be regenerated by using a dynamo whenthe vehicle is in operation.

We have designed the chassis on CATIA, as it was userfriendly and also we have done analysis by taking thematerial AISI 1018 as it has yield strength 320 MPA andultimate strength 450 MPA which has a high strength whilecomparing with other materials

YOUNG’S MODULUS 210 GPA

STRENGTH TO WEIGHT55-60 Kn-m/kg

RATIOThermal expansion 11.9 um/m-k

DENSITY 7.8 g/cm^3

Abstract

In general, there are three types of hybrid systems(based on engine motor shaft alignment) available inour market. Series hybrid, Parallel hybrid and Series-Parallel hybrid systems. We have preferred parallelhybrid system and made few modifications to it , Toovercome the drawbacks. One such major modificationis usage of dynamo along with regenerative braking forincreasing alternate energy production. The mainreason for making such change is the more efficientproduction of energy by dynamo in long run whencompared to that of regenerative braking which isrestricted to city life. This makes our vehicle moreefficient when compared to that of vehicles usingParallel hybrids and other types, since it adds the extraalternate energy produced by that of dynamo inrunning condition.

I. Manufacturing process

In the process of manufacturing a hybrid vehicle, the processes involved are:

Designing

Manufacturing

Simulation

A. Designing & Manufacturing

The chassis design is

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Imperial International Journal of Eco-friendly TechnologiesVol. - 1, Issue-2 (2017), pp.61-73

IIJET

Fig. 1: actual chassis we have developed

II. Results

By doing analysis to the designed vehicle on CATIA of front impact and rear impact, the results are:

A. Front impact

Front impact test is to check the survivability of the chassis during a frontal impact.

The actual chassis we have developed is shown below:Deflection=1.00224mm, Maximum stress: 165.032 MPA

B. Real impactRear impact test is very similar to the front impact but inthis case vehicle is considered to be movable so during

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impact the vehicle experience less G-Force than frontimpact test.

Deflection: 6.86038 mm; Maximum stress: 294.22 MPA.

C. Side test

During a side impact the vehicle experiences approximatelyhalf of the force that it experience during front impact.

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Deflection: 9.40154 mm; Maximum stress: 281.46 MPA

D. Torison testIn torsion test the back member where the arms are placed are fixed and torsion is applied on it.

Deflection: 8.08424 mm; Maximum stress: 194.244 MPA

BI. TransmissionIn the part of transmission of the vehicle while fulfillingthe requirement of vehicle have to be run on both ICengine and motor we have decided to use the parallelhybrid system as it was most efficient and also the engineshaft engages with clutch, gear box and differential setupused in Bajaj auto which has four variable speeds of gearreductions. And the motor is directly mounted on the shaftby using a free wheel which is based on the mechanismRatchet-Pawl. Which will transfer power only on onedirection and reverse direction of power transmission isrestricted by using this type of free wheels.The engine and motor that we have used the specificationsare:

1. Engine

2. Motor

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A. Engine mounting

Engine is directly mounted to the clutch shaft in whichboth the gear box and differential had in a single setup.

FIG. 2: -actual engine mounting we have made

B. Motor mounting

Motor is directly mounted on the output of differential shaftby a free wheel connected through chain sprocket. Themotor speed is controlled with motor controller by using afoot pedal.

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Suspension is the term given to the system ofsprings, shock absorbers and linkages thatconnects vehicle to its wheels.

Introduction to suspension system:

o To maintain good contact between wheels and road surface.

o To maintain good ride height.o To increase the stability of car during ride.

o To provide good comfort to the passengers.

As per our requirements we chosenFront double wishbone suspension (damper to

rocker arm)

Rear double wishbone suspension (damper to upper arm)

A. Front suspension1. Double wishbone suspension

In automobiles, a double wishbone (or upper and lower A-arm) suspension is an independent suspension design usingtwo wishbone-shaped arms to locate the wheel.

B. Design and analysis of suspension parts1. A arms

In automotive suspension, a control arm, also known asan A-arm, is a hinged suspension link between the chassisand the suspension upright or hub that carries the wheel.Wishbones are triangular and have two widely spacedinboard bearings. These constrain the outboard end of thewishbone from moving back and forth, controlling twodegrees of freedom, and without requiring additional links.

2. Front A armsUpper A ARM (designed by using CATIA software)

Length of the A arm = 307 mm

III. Suspension

64Lower A arm (designed by using CATIA software)Length of the A arm =311mm

Rear A arms: Length of a arm =319 mm

3. Suspension knuckle

A suspension knuckle attaches the upper and lowersuspension components to the wheel support assembly andis the mounting point for the wheel spindle or hub. It iscalled a “steering knuckle” if it is used in a locationrequiring the wheel to turn, where the knuckle rotates onthe lower ball joint, allowing the wheels to turn left orright.

Front knuckle (designed by using CATIA software)

Imperial International Journal of Eco-friendlyTechnologies Vol. - 1, Issue-2 (2017), pp.61-73

IIJETRear knuckle (designed by using CATIA software)

Springs and dampers

Springs: It absorbs road shocks or impacts due to bump in road by oscillating.Tires also provides spring effect, but to a smaller extent. Dampers: They reduce the tendency of the carriage unit to continue to “bounce” up and down on its springs.Oscillation due to road shocks are restricted to a reasonable level by damper.

Design of helical compression spring for shock absorber:

Material: Music Wire (ASTM A228)

Mean diameter of a coil D=64 mm

Diameter of wire d = 8 mm

Total no of coils n = 12

Outer diameter of spring coil D0 = D + d = 72 mm

Inner diameter of spring coil Di = D - d = 56 mm

No of active turns n= 10.5

Weight of vehicle = 150 Kg (spring weight)

Let weight of 1 person = 70 Kg

Total Weight (Wt.) = Weight of vehicle + Weight of 1 persons

= 150+70 = 220 Kg

Weight distribution bias Front/Rear= 40/60 %

40/60 % of 220 = 88/132 Kg

Considering dynamic loads (Rear) it will be doubleWt = 264Kgs = 2413 N

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For single shock absorber weight (W) =Wt/2=2413/2 =1206.5 N

Spring Index = D/d = 8

Solid length Ls = n*d= 12*8 = 96 mm

Free length of spring, Lf = solid length + maximum compression + clearance betweenadjustable coils = 250 mm

Pitch of coil, P = 10.42

Damper eye to eye = 330 mm

By using these static values, we obtained:

1. Spring constant, K = 14.7 N/mm

2. Maximum displacement possible = 150 mm

3. Maximum load possible = 2200 N

4. Maximum shear stress possible = 8.31*10^8 Pa

5. Length of the wire required to make spring = 2530 mm

6. Solid height = 100 mm

7. Distance between coils in free spring = 23.8 mm

8. Rise angle of coils = 6.75 deg

9. Mass of spring = 0.999 Kg

10. Lowest spring resonant frequency = 60.6 Hz

11. Shear modulus of material ,G = 79 G Pa

Other parameters in suspension:

A. Track width

The Track width is the measurement from tire centre to tirecentre. With Twin tires, measurement is made from thecentre of the twin tire to the centre of the twin tire. This hasa significant influence on the cornering behavior of avehicle.As per the requirements track width of vehicle = 1099 mm

B. Wheel base

The WHEELBASE of a vehicle equals the distancebetween its front and rear wheels. At equilibrium, the totaltorque of the forces acting on a vehicle is zero. As per therequirements wheelbase of vehicle = 1465 mm

C. Roll center

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The roll centre is the point about which the body can rollwithout any lateral movement at either of the wheel contactareas.

Front Roll centre = 8.242 mm

D. Motion ratio

Motion ratio in suspension of a vehicle describes theamount of shock travel for a given amount of wheel travel.Mathematically it is the ratio of shock travel and wheeltravel. The amount of force transmitted to the vehiclechassis reduces with increase in motion ratio. A motionratio close to one is desired in vehicle for better ride andcomfort. One should know the desired wheel travel of thevehicle before calculating motion ratio which dependsmuch on the type of track the vehicle will run upon.

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Motion ratio = d1/d2

= 263/330

= 0.797.

E. Anti - dive & anti – squat

Anti-dive and Anti-squat are expressed in terms ofpercentage and refer to the front diving under braking andthe rear squatting under acceleration. They can be thoughtof as the counterparts for braking and acceleration as RollCenter Height is to cornering. The main reason for thedifference is due to the different design goals between frontand rear suspension, whereas suspension is usuallysymmetrical between the left and right of the vehicle.

ANTI- SQUAT = 63%

F. Ride height

Ride height (also called ground clearance orimply clearance) is the amount of space between the baseof an automobile tire and the underside of the chassis; or,more properly, to the shortest distance between a flat, levelsurface, and any part of a vehicle other than those partsdesigned to contact the ground (such as tires, tracks, skis,etc.). Ground clearance is measured with standard vehicleequipment, and for cars, is usually given with no cargo orpassengers.Ground clearance of vehicle = 8 cm

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Bump Steer is when your wheels steer themselves withoutinput from the steering wheel. The undesirable steering iscaused by bumps in the track interacting with improperlength or angle of your suspension and steering linkages.Most car builders design their cars so that the effects ofbump steer are minimal.

H. Weight distribution

Weight transfer customarily refers to the change in loadborne by different wheels during acceleration. This is moreproperly referred to as load transfer.

Kerb weight on front axle = 40%

Kerb weight on rear axle = 60%

3. Suspension parametersA. Camber

Camber angle is the angle made by the wheels of a vehicle;specifically, it is the angle between the vertical axis of thewheels used for steering and the vertical axis of the vehiclewhen viewed from the front or rear. It is used in the designof steering and suspension.As per our requirements camber angle = 3 deg (negative)

B. Caster

The caster angle or castor angle is the angular displacementfrom the vertical axis of the suspension of a steered wheelin a car, motorcycle, bicycle or other vehicle, measured inthe longitudinal direction.As per our requirements caster angle = 5 deg (positive)

G. Bump steer

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C. Toe-in:

In automotive engineering, toe, also known as tracking, isthe symmetric angle that each wheel makes with thelongitudinal axis of the vehicle, as a function of staticgeometry, and kinematic and compliant effects. Positivetoe, or toe in, is the front of the wheel pointing in towardsthe centre line of the vehicle

As per our requirement toe-in = 10 mm

Fig. 1: actual wishbone suspension we have developed

Steering

A. Introduction

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IIJET

The controlling behavior of a vehicle is influenced by theperformance of its steering system. The steering systemconsists of steering wheel, steering column, rack andpinion steering box, tie rods, and universal joint. Ourvehicle is controlled by movement of pinion over rack andthis motion is transmitted through tie rods into the steeringknuckles.

We have chosen to incorporate Ackermann mechanism as itwas universally due to its simplicity

Ackerman is the difference in turn radius between the fronttires. The Ackerman can help the car turn better through thecenter of turn.

The relationship between inner wheel angle and outerwheel angle

Cotα – cotβ =w/l

Where α= outer wheel angle,

β=inner wheel angle,

w=track width,

l=wheel base.

MECHANISM OF RACK AND PINION STEERINGSYSTEM

As a steering wheel is turned, it spins the pinionover the rack, centrifugal force slides rack backand forth. Tie rods are connected to each end ofrack, which activate the steering arms. Steeringarms are connected to each wheel, and cause themto turn.

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For our convenience we take steering ratio as 10:1.

ACCORDING TO ACKERMAN GEOMETRY,

Ackerman geometry is closely approximated by atrapezoidal arrangement the asymmetry in geometry causesinner wheel steer to greater angle than the outer wheel.

From the above

Inner wheel angle, β=38.5 deg

Imperial International Journal of Eco-friendlyTechnologies Vol. - 1, Issue-2 (2017), pp.61-73

IIJETCot α-cot β=w/l

Cotα-cot 38.5=1099.05/1465.4

Outer wheel angle, α =26.48 de

KINGPIN INCLINATIONThe kingpin is set at an angle relative to the true verticalline, as viewed from the front or back of the vehicle. Thisis the kingpin inclination or KPI (also called steering axisinclination, or SAI).SAI is non-adjustable.

SCRUB RADIUSThe scrub radius is the distance in front view between theking pin axis and the center of the contact patch of thewheel, where both would theoretically touch the road.

SPECIFICATIONS

Track width 1099.05 mm

Wheel base 1465.4 mm

Steering arm length 100 mm

Steering arm angle 20.6 deg

Steering ratio 10:1

Inner wheel lock 38.5 deg

Outer wheel lock 26.48 deg

Kerb weight 170 kg

Rack length 300 mm

Rack travel 130 mm

No. of turns 1.41

Weight of driver 70 kg

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Force required on37.67 N

steering wheel

Turning radius 2457.65 mm

Tie rods lengths 364.4 mm

Tie rod inclination 15.5 deg

Steering column length 700 mm

Steering wheel250 mm

diameter

King pin inclination 10 deg

Fig. 2: actual steering we have developed with rack andpinion mechanism using ackermann geometry

We have used bearing at the wheel arrangement to the chassis.

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IIJETBraking system

A. Objective

A brake is a device by means of which artificial frictionalresistance is applied to a moving machine member, in orderto retard or stop the motion of a vehicle .Most brakescommonly use friction between two surfaces pressedtogether to convert the kinetic energy of the moving objectinto heat. The vehicle has two independent hydraulicsystems and it is actuated by a single brake pedal. Thepedal directly actuates the master cylinder. Here no Cablesare used for this purpose. All rigid brake pipes are mountedsecurely along the roll cage or along other members.

B. Components

Brake pedal, Tandem master cylinder, brake linings,caliper, rotor areSuitable components of disc brake system.

C. Rotors

The disc of brakes are made of grey cast iron andis of solid disc, as in ventilated type disc poor heattransfer due to blocking of holes.

We use casted disc of thickness 8mm and outer diameter of 155mm in accordance to our design.

D. Calliper

We have used a fixed type Caliper in our design.Fixed type caliper doesn't move but has piston(s)arranged on opposing sides of the rotor.

We have selected pulsar 220 rear calipers as it issmall enough to fit in wheel assembly & hasmaximum piston diameter of 30mm.

E. Master cylinder We have selected master cylinder of Maruti 800

which has a bore of diameter of 19.05mm.

F. Brake circuits A brake circuit of diagonal split system is used as

in case of a failed hydraulic circuit, there are still two brakes that provide equal braking forces. For this reason, the vehicle won’t turn or pull in either direction under failed-circuit braking.

G. Brake fluid We have decided to use DOT3 brake fluid as it is

inexpensive & compatible with one another.

Design considerationso Brake disc thickness:8mmo Brake disc type :fullo Brake disc diameter:155mm

70Technical specifications:

o Net vertical force onvehicle(static):2354N

o Vertical force on front(static):975N o Vertical force on rear(static) :1379N o% of front weight(static):41.4%

o CG height : 266mm(10.47in)o Wheel base : 1465mm(57.67in) oEffective disc radius=67.5mm

H. Calculations

Brake pedal:Brake pedal is mainly intended to multiply the forceexerted by driver. Brake pedal ratio may be taken as7:1.By lever ratio of brake pedal assembly Fbp = Fdx L1/L2Where Fbp=Force output of brake pedal assembly Fd=Force applied to the pedal pad by driver=85lb L1=the distance from the brake pedal arm pivot to the output rod clevis=7L2=the distance from the brake pedal arm pivot to the brake pedal pad=1.

Fbp = (85x9.81x7) / (2.20462x1) =2648N

Pressure in master cylinder:As fluids are incompressible and infinitely rigidhydraulic vessels, the pressure generated by mastercylinder will be

Pmc=Fbp / Amc= 2648/ (2.85x10^-4)=9.28x10^6 N/m^2Where Pmc=Hydraulic pressure generated by mastercylinderAmc=Area of master cylinder piston.

Forces on calliper:

o Considering no losses in brake lines thepressure transmitted to the brake lines will be equal.

Pcal=Pmc=9.28x10^6 N/m^2.o Forces in caliper is

Fcal=Pcal * Acal= (9.28x10^6)*(7.0685x10^-4)

=6566NWhere Fcal=Force generated by

caliper.Acal=Area of caliper hydraulic pistonfound one half side of the body.

o As each caliper has two clamps i.e, two pistons in fixed type caliper , so Fclamp=Fcal x2

=13132NWhere Fclamp=clamp force generated by caliper.

Imperial International Journal of Eco-friendlyTechnologies Vol. - 1, Issue-2 (2017), pp.61-73

IIJETo The clamping force causes friction which

acts normal to this force and tangential tothe plane of the rotor. The friction force isgiven by:Ffric=Fclamp * ubp =13132x0.35

=4596.2N

o The braking torque is related to force on brake pads friction force.

Tr=Ffric x Reff=4596.2 x 0.0675

=310.2435 Nm.o As brake disc is connected to hub of the tire

so, effective torque is same considering nolosses.Tt=Tr=310.2435 Nm.Where Tt=Torque on tire.

o Force on tire is Ft=Tt/Rt =310.2435/.217=1429.7N

Where Ft= Force acting on a tire.o Total force acting on all tires is Ftotal=4xFt

x utr=4x1429.7x.7=4003.14NWhere Ftotal=Total force acting on all tires of vehicle.

o The deceleration of the vehicle will be equal toav=Ftotal / mv =4003.14/240=16.68

m/s^2Where av=deceleration of vehiclemv=mass of vehicle.

o For a vehicle experiencing a lineardeceleration, the theoretical stoppingdistance of a vehicle in motion can becalculated as follows:

SD=v^2 / (2xav)= (12.5^2)/(2x16.68)=4.68m

I. Weight distribution

In the side view, the sum of the left front and right frontweights will equal the front axle weight and the sum of theleft rear and right rear weights will equal the rear axle weight.If these values are known, then the static weight distributioncan be calculated as follows:Percentage front weight : Wf/Wt x 100

=981/2354.4 x100=41.66%

Percentage rear weight: Wr/Wt * 100

=1373.4/2354.4 x100

=58.34%

71Where Wt=Total vertical force (weight)

Wf=Front axle vertical force (weight)

Wr=Rear axle vertical force (weight)J. Weight transfer

Whenever a vehicle experiences a deceleration, the frontaxle normal force during a deceleration event will increasewhile the rear axle normal force will decrease by the sameamount. The magnitude of weight transferred from the rearto the front is a function of deceleration and vehiclegeometry:

WT=(av/g)x(hcg/WB)xWt

=(16.68/9.81)x(0.266/1.465)x2354.4

=726.8N

Where hcg= the vertical distance from the CG to groundWB=Wheel base of vehicle.

The dynamic weight transferred from the rear to the frontmust be added to the front axle static weight and subtractedfrom the rear axle static weight as follows:

Wfd=Wf+WT

=981+726.8=1707.8N

Wrd=Wr-WT=1373.4-

726.8=646.6N

Where Wfd=the front axle dynamic vertical force for a given deceleration.

Wrd=the rear axle dynamic vertical force for a given deceleration.

% of Weight Front axle Rear axle

Static 41.66% 58.34%

Dynamic 72.5% 27.5%

Pedal Force 378.228 N

Brake Force 2647.6 N

Fluid Pressure 9.28 x 10^6 N/m^2

Braking Torque 310.24 N-m

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Deceleration 16.68 m/s^2

Stopping Distance 4.68m

K. Driver safety

We have made the seat and drivers compartment with a fireresistant material, we have the seat belt of four harness ,and fire extinguisher of 1 kg with the vehicle and 2 killswitches –one is in front of the driver and other behinddriver sear. We have rigidly mounted the engine and motorto the chassis and also taken proper care to avoid any trackto power supply to the chassis. We have also placed a firewall which will separate the driver from the power systemsand tractive systems which is made of fire resistantmaterials.

Advantages

We have used a 12V dynamo which is directlyconnected to the rear shaft(for which the totalpower is transmitted) when the vehicle is running

72on either engine or on motor in both cases the poweris generated from the dynamo whose output wasagain connected to batteries using a cutoff circuit.

By using this cutoff circuit when the battery isfully charged, this circuit will automatically opens

Because of this regenerative system more power isgenerated than by using the regenerative brakingthat is usually used in the hybrid vehicles.

Because of this the mileage of the vehicle will increase significantly.

Ecofriendly and fuel economic.

Practically used parts & materials

tires,

hubs,

brake calipers,

tmc ,

tie rods and rear axle of maruti 800, steering rackwe have machined. For suspension we have usedunicorn mono suspension dampers. We have madethe steering column by our own. For tractivesystem we have used 48V and 15A supply(4batteries each of 12V and 15A) and to recharge thebattery while the vehicle is moving on either ofthe engine or motor we have used a 12V dynamoi.e, easily available in the automobile in marketconnected to sprocket with maintaining a ratio of1:3. For paneling the drivers compartment and firewall purpose we have used G.I sheet of 0.4 mmthickness and engine and motor are rigidlymounted. Drivers compartment is covered totallywith fire resistant material , and also placed twokill switches for pull and push tires in front ofdriver and beside the shoulder of the driverscompartment.

IV. CONCLUSION

We have tested the kart for its fuel economy under threeconditions running fully on IC engine, running fully onelectric motor, & running on combination of both electricand ic-engine(hybrid). In our project we have used an oldDC starter motor of a car which has very high currentconsumption at start-up because of high torquerequirements during start up,by gaining speed gradually thecurrent consumption decreases so the battery drains outquickly reducing the overall efficiency.insead of this toimprove the performance high efficiency DC brushlessmotor can be used which has low current consumption.incities cars have speed around 40 to 45 kmph and powerfulmotor is capable to drive car at this speed due to thisexhaust gases emissions can be reduced in cities and this ishelpful for health and global warming. Currently hybrid

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vehicles utilize NI-MH battery technology which needsreplacement after sometime some period. But instead ofthis lithium ion batteries which are very reliable can beutilized.however the intial cost increases this is a newtechnology. Nowadays new bio fuels are also made toreduce the atmospheric pollutionand cut down the fuelpressures. Also use of CVT in hybrids has proven that theyare having better transmission efficiency than the normalones combining CVTs with the smart computer integratedcircuits and smart sensors the efficiency can be greatlyimproved. New inventions are lighter but strongermaterials like carbon fibers,HSP are helpful in reducingoverall weight of the car and the small sized highefficiency engines can be used.

www.wikipedia,orgwww.kartbuilding.netwww.howstuffworks.com

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