chassis & vehicle dynamic

8/13/2019 Chassis & Vehicle Dynamic

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Universiti Kuala lumpur

Malaysian Spanish InstituteSCB23503 CHASSIS & VEHICLE DYNAMICS

Brake System Lab

Prepared by:Mohd Shahrizal Bin Shamsudin (54270212081)

Mohamad Zaim Bin Anuar (54270113074)Ganes A/L Raja (54270113110 )

Muhammad Addham Bin Mohd Aini (54270212011)Muhammad Zaki Bin Abdul Rahim (54270212065)

Muhammad Aiman Bin Mohd Radzi (54268113091)

Checked by:En. Mior Firdaus Bin Mior Abd Majid


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OBJECTIVES

To describe basic wheels and hub design Explain the differences between the two types of tires constructionsin use today. Describe the operation, diagnosis and service for a tire pressuremonitor. Describe the differences between static balance and dynamicsbalance. Describe the technology of Tire Pressure Monitoring System (TPMS).


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Two types of tires constructions in use today:Diagonal ply/Cross-ply tires

commonly used tires designs are bias, belted bias, and beltedradial and the cords crisscross each other.

Its usually at an angle of 25 to 45 to the centre line. The bead of a cross-ply tyre consists of bundles of bronze

coated high tensile strength steel wire strands which areinsulated with rubber.

Cross ply use a tyre carcass that called cord body that consist oflayer of nylon plies that act to confine the pressure whichsupport the tyre load and absorb shock encountered duringdriving.


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Figure 1: Sample of Crossply

construction


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Radial Ply-tires

In radial ply-tires the ply cords are arranged radially at a rightangle to the tire centre line.Steel belts are commonly used in radial tires, but other beltsmaterial such as fiber glass, nylon and rayon have also beenused.It are crisscrossed at an angle of 10 to 30 in relation to the tirecentreline.

The tyre carcass of the radial ply is called body ply whichmade by single layer of steel cord wires that run from bead tobead laterally to the direction of motion.

It act to carries the heavy load and transmit the force from

the bolts to the bead.


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The chafer for the radial ply act as a reinforcement byincrease overall stiffness of the bead tyres.

Radial tires provide less rolling resistance, better steering

characteristics and longer tread life than bias ply tires.


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Figure 2 : Sample radialconstruction


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Diagonal ply/Cross-ply tires Radial Ply-tires

Constructed of 2 or more plies or layersof textile casing cords, positioneddiagonally from bead to bead.

Provides a strong, stable casing, withrelatively stiff sidewalls and offer good

traction on poorly surfaced ground.feature a very high resistance tosidewall damage, good mileage

provide high lateral stabilitygreat rigidity of tyre structureprotect the bead and body from chafing

Wide tread lugs that serves hightraction capability and good self cleaningproperties and performance.

Better heat resistance and good wearresistance

Have a far greater rigidity for when carsare cornering and the tyres aredeforming.

All radial tires are belted.higher cut resistance in treadFull bite traction on stone and soft oil

traction that give more perfect totraction.

provide better fuel economy

Greater vertical flexibility while ensuringthere still much surface that contact withthe road.

Comparison between Cross-Ply Construction and Radial Constructions


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Feathered Edges. Represent a "toe-in/out" problem butdepending on the direction of the "feathering", may representother problems like rear tandem alignment. Also this pattern

may represent severely out of align tandem or a bent axle. Cupping. Mostly due to out of balance wheel assembly. Rear

wheels are not as susceptible to this type of wear due to theextreme amount of weight on the axle. Although shocks on

modern commercial trucks are more important now than inthe past.


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Cupped Edges. a tire is cupped on both the inside andoutside is typical wear from improper (too light) tireloading, improper inflation or a tire that is not designedwith a small rib that is molded on the very outer edge.Tire surface where it meets the road is not a flat butslightly rounded. Tire wear like this may result from theouter edges turning slightly slower than the center of thetire.

Excessive Wear One Side. The fourth image is fromimproper camber. Camber is the angle of the wheeltipping (or leaning) in or out from the centerline of thevehicle. Some commercial trucks manufactured todayuse a fabricated (made of welded steel) axle. Though

camber corrections on this type of axle using specialtooling is possible, it is not a recommended practice. Diagonal Wipe. This type of wear in the fifth image is not

typical wear on any commercial truck. Where this is seenis on commercial trailers that turn in a very tight radius

scuffing the tires in a sideways fashion.


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Tyre Pressure Monitoring System (TPMS)

Maintaining proper tyre pressure is essential for the safetyand performance of a vehicle.

It also plays a significant role in decreasing fuel consumptionand extending tyre life.In addition to increased fuel consumption and tyre wear, longperiods of driving with low tyre pressures can cause

additional stress on the tyre sidewalls.This results in increased operating temperatures that can leadto premature tyre failure. Tyres operating with low pressurescan also affect the vehicles handling and performance.


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In a worst-case scenario, under-inflation can lead to a tyre blow-out ortread separation. Automated Tyre Pressure Monitoring Systems or TPMS provide a means of reliable and continuous monitoring of the vehicle tyrepressure and are designed to increase safety, decrease fuel consumptionand improve vehicle performance.

There are two types of tyre pressure monitoring; direct and indirect. Thedirect monitoring system uses a pressure sensor mounted inside eachwheel and uses a wireless transmitter to give direct tyre pressurereadings. The indirect system uses the vehicles wheel speed sensors todetermine if a tyre is under inflated when compared to each of the othertyres.

TPMS can be fitted to all vehicle types using conventional and run flattyres. With a Tyre Pressure Monitoring System installed on a vehicle,drivers can monitor the tyre pressures and temperatures from the driversseat to ensure that their tyres are properly inflated under all operatingconditions.


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The interactive display inside the vehicle shows:

i. The required tyre pressure.ii. The actual tyre pressure.

iii. The tyre pressure status.iv. The temperature of the tyre.

v. The driver can use the display control buttons to check the

status of each tyre.


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Figure 3 : Example of Tyre Pressure Monitoring System(TPMS) which attach in wheel.

chassis & vehicle dynamic

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