UEAUA36 TWO AND THREE WHEELERS. BY. B.HARISHBABU Asst.prof,VTU. UNIT I. FUEL. A I R. Ignition. Fuel/Air Mixture. Combustion Products. Intake Stroke. Power Stroke. Compression Stroke. Exhaust Stroke. Four Stroke SI Engine
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Four Stroke SI Engine
Stroke 1: Fuel-air mixture introduced into cylinder through intake valve
Stroke 2: Fuel-air mixture compressed
Stroke 3: Combustion (~constant volume) occurs and product gases expand doing work
Stroke 4: Product gases pushed out of the cylinder through the exhaust valve
Spark plug for SI engine
Fuel injector for CI engine
IVO - intake valve opens, IVC – intake valve closes
EVO – exhaust valve opens, EVC – exhaust valve opens
Xb – burned gas mole fraction
Cross Loop Uniflow
EPO – exhaust port open
EPC – exhaust port closed
IPO – intake port open
IPC – intake port closed
Pint < Patm
Power Regulation (Throttling)
An IC engine is basically an air engine, the more air you get into the
cylinder, the more fuel you can burn, the more power you get out.
The initial pressure in the cylinder is roughly equal to the pressurein the intake manifold.
Pressure in the intake manifold is varied by opening and closing the
throttle plate to change the pressure drop. Maximum air flow (andpower) achieved at wide-open-throttle (WOT). Minimum air flow at idle
Mixture to manifold
During start-up the components are cold so fuel evaporation is very slow, as a result
additional fuel is added through a second injecting valve
Superchargers are compressors that are mechanically driven by theengine crankshaft and thus represent a parasitic load.
Pint > Patm
Turbochargers couple a compressor with a turbine driven by the exhaust
gas.The compressor pressure is proportional to the engine speed
atmospheric – small DP across turbine.
In order to produce enough power to run compressor the turbine speed
must be very fast (100k-200k rev/min). It takes time for the turbine toget up to speed so when the throttle is opened suddenly there is a delayin achieving peak power - Turbo lag.
Waste gate valve controls the exhaust gas flow rate to the turbine.
It is controlled by the intake manifold pressure
Electronic ignition system greater than
A centrifugal clutch is a clutch that uses centrifugal force to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
Chassis to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
The two-wheeler chassis consists of the frame, suspension, wheels and brakes. The chassis is what truly sets the overall style of the two-wheeler. Automotive chassis is the main carriage systems of a vehicle. The type determines the gearing configuration, flex and the type of modifications that can be accommodated.
Frame: The frame serves as a skeleton upon which parts like gearbox and engine are mounted. It can be made of steel, aluminum or an alloy. It keeps the wheels in line to maintain the handling of the two-wheeler.
Suspension: It is a collection of springs and shock absorbers. It can be of two types: front suspension and rear suspension. It insulates both the rider and the bulk of the machine from road shocks and also keeps the wheels in the closest possible contact with the ground and gives control of the vehicle to the rider. The front suspension helps to guide the front wheel, to steer, to spring, to dampen, and to provide support under braking.
Types of Frames: to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
Motor cycles / Mopeds use three basic frame designs:
1.Cradle Frame, (2) Back Bone Frame, (3) Stamped Frame
The cradle frame is one of the most enduring type and is shown in figure
Stamped underbone frame to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
Details of shock absorber
Wheels: to connect two concentric shafts, with the driving shaft nested inside the driven shaft. A wheel is a circular object which with an axle, allows low friction in motion by rolling. A wheel is made up of the rim and spokes or disc plate. Wheels should be aligned properly because it directly influences driving. Two-wheeler wheels are generally of aluminum or steel rims with spokes.
Brakes: Generally, there are two independent brakes on a two-wheeler: one set on the front wheel and one on the rear, however, there are many models which have 'linked brakes' and apply both at the same time. The front brake is generally much more powerful than the rear brake. Brakes can either be drum or disc based. When the rider operates one of the brakes, a fluid element known as hydraulics is pressurized to provide the required forces to squeeze the brake pad material onto the rotor and slow down or stop the vehicle.
Gear Box: to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
The motorcycle gear box contains a number of gears in different sizes. In the process of gear switching, different pairs of gearwheels lock together. A large and small wheel lock together in the lowest or slowest gear. Similar size wheels lock together in the highest or fastest gear.
The motorcycle gear box is the component that makes the actual ratio between the engine and the driving wheels. It is also referred to as transmission gear.
Types of Motorcyle Gear Box:
In a general manner, the motorcycle gear box can be of three types, they are:
Horizontally Split: It has a seam on the horizontal plane.
Vertically Split: It has a seam on the vertical plane.
Cassette Type: The gears are loaded in from one side.
Characteristics of Gear Box: to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
The gears are constantly meshed with one another and they are always spinning.
Uses of Gear Box:
It controls gear and shaft alignment.
It controls the engine RPM.
It protects the gears and lubricants from water, dust and other environmental contaminants.
Functions of Two Wheeler Shock Absorbers: to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
They absorb the shock from bumps on the road and helps to 1.make riding safe and smooth.
2.they allow the use of soft springs while controlling the rate of 3.suspension movement in response to bumps.
4.They also, along with hysteresis in the tire itself, damp the motion of the unsprung weight up and down on the springiness of the tire.
5.Shock Absorber system make the vehicle manageable.
Materials used for making Shock absorbers:The most commonly used materials for making these absorbers are:
Maintenance of Shock Absorbers:
It should be checked regularly.
Oils should be changed according to the recommended time.
Suspension system to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
A Motorcycle Suspension System consists of a spring coupled to a viscous damping element, a piston, in a cylinder filled with oil. The piston smooths out vibrations induced by the vehicle while moving as it moves through the oil. The flow of oil through the piston is regulated by an adjustable elastic deformable flap called a shim.
Types of Motorcycle Suspension:
Front Suspension: The predominant type of front suspension is the suspension fork. The bottom part of the fork is fitted over the tubes that connect the fork to the frame. When the vehicle hits a bump, the spring gets compressed and the piston forces fluid through the orifice.
Rear Suspension: Most of the time the rear suspension are used as a shock absorber
Functions of Motorcycle Suspension: to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
The main functions of the motorcycle suspensions are:
To insulate both the rider and the bulk of the machine from road shocks. It makes a much safer and comfortable ride and is important for proper mechanical reliability and longevity.
To keep the wheels in the closest possible contact with the ground and gives control of the vehicle to the rider.
The front suspension helps to guides the front wheel, to steer, to spring, to dampen, and to provide support under braking.
Materials used for making Suspensions:
The materials most commonly used for making suspensions are:
Maintenance of Suspensions:
The suspensions should be checked for loose nuts and bolts and leaks.
The swing arm bearings should be lubricated monthly.
UNIT III to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
Disk brake to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
Components of Disk brake:
Drum brake to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
Wheel parts: to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
A wheel is a circular object which with an axle, allows low friction in motion by rolling. A wheel is made up of the rim and spokes or disc plate. The standard size of wheels for two-wheelers is 17 inch. Wheels should be aligned properly because it directly influences driving.
Parts of a Wheel:
There are two basic parts of a Wheel:
Wheel Spoke or Compact Disc
Tire is also an important part of a wheel. It works as a wheel only after it is installed on the rim and is inflated.
Two types of spokes. to connect two concentric shafts, with the driving shaft nested inside the driven shaft.
Spoked wheel transmits driving torque and braking torque through different set of spokes.
Split disc wheel
Wheel hub details
Materials used for making Motorcycle Wheel Parts: through different set of spokes.Wheel for two-wheelers are usually made of aluminum. Magnesium is also used for making wheels, but they are meant for race bikes because they are very strong and light. Even carbon fibers are also used for making wheels.
Maintenance of Motorcycle Wheel Parts:Though a simple device, the wheel needs proper care and maintenance to keep it taut and free of damage and in perfect balance.
Regular inspection for loose or damaged spokes is a must.
They must be kept clean and free of rust.
The wheel should be aligned properly otherwise it can wear the tires, reduce tire mileage and impair steering and cornering.
Proper checking of the wheels to insure that they are in good condition is a must because cracked or bent wheel can lead to the loss of air and cause subsequent deflation of the tire.
Tyre through different set of spokes.
A Rubber Tire is a device covering the circumference of a wheel. It is an essential part of most ground vehicles. The combination of air with rubber tire supports the vehicle and its contents.
Part of a tyre through different set of spokes.
Figure: Simple tyre tread patterns
Tyre wear: (1) Skid depth. (2) Side wall. (3) Wear indicator
Tyre road contact for different extent of tyre inflation: (a) Correct inflation. (b) Under inflation, tyre cries “May side walls are heated due to bending. I need more air”. (c) Over inflation.
Parts of a Rubber Tire (a) Correct inflation. (b) Under inflation, tyre cries :
The Bead: fits inside the rim of the wheel and is held in place by tire pressure.
The Sidewall: protects the cord plies and has all the tire information printed on it.
The Tread: provides strength and stability and is the interface that provides traction to the road surface.
The Belt Plies and Body Plies: give the tire its stability and resistance to road damage.
An inner liner: combats permeability (keeping the air in the tire).
Sipes: are small slits in the tread that improve traction.
Functions of Rubber Tires:
Rubber Tire absorbs the shock of road roughness and can provide a smooth, safe ride.
They protect the wheel from wear and tear.
They provide a high-friction bond between the vehicle and the road to improve acceleration and handling.
They also provide other functions such as traction for moving, stopping and steering as well as providing a cushion for the vehicle
UNIT IV & V (a) Correct inflation. (b) Under inflation, tyre cries
Two wheelers (a) Correct inflation. (b) Under inflation, tyre cries
Case study to Two wheeler and three wheeler
Motor Cycle components (a) Correct inflation. (b) Under inflation, tyre cries
Unit 5: Three Wheelers (a) Correct inflation. (b) Under inflation, tyre cries
Case study of Autorickshaws, Pick up vans, delivery van and Trailer – servicing and Maintenance.
For details (a) Correct inflation. (b) Under inflation, tyre cries
Thank you (a) Correct inflation. (b) Under inflation, tyre cries