Unit 1: Session 1 Flashcards
What is the purpose of a chassis?
Chassis is used for fixing the auto body
Chassis provides structural support for the vehicle components.
What material is a chassis typically made of?
Chassis is made of metal
Metal provides the necessary strength and durability.
Define a 4 X 2 drive chassis vehicle
A 4 X 2 drive chassis vehicle consists of 4 wheels out of which 2 wheels are the driving wheels.
Define a 6 X 4 drive chassis vehicle
A 6 X 4 drive chassis vehicle consists of 4 wheels and all of them are the driving wheels.
What is a full forward chassis?
Full forward chassis is one in which the engine is fitted outside the driver cabin.
What is a semi-forward chassis?
In Semi-forward chassis, half portion of the engine is in the driver’s cabin and the remaining half is outside the cabin.
Define Chassis
It is frame on which the major components such as engine, Transmission system, suspension system, braking system etc are mounted on.
Classify the chassis according to the fitment of the engine
a. Full forward
b. Semi-forward
c. Bus chassis
d. Engine in front
e. Engine at centre
Define a 4 X 4 drive chassis vehicle
It is a vehicle which consists of 4 wheels and all of them are the driving wheels.
Define a 6 X 2 drive chassis vehicle
6 X 2 drive chassis vehicle – consists of 6 wheels out of which 2 wheels are the driving wheels.
What are the different types of chassis frames used in automobiles?
Conventional and integral chassis frames are the two types of chassis frames used in automobiles.
List the advantages of Integral Frame Chassis over conventional type Chassis frame
Advantages:
* Cost is less, as the body floor works as long and cross members.
* Deadweight of vehicle is less.
* Vehicle have better stability because the center of the gravity is lowered due to elimination of the frame.
List the disadvantages of Integral Frame Chassis over conventional type Chassis frame
Disadvantages:
* In case of an accident, it becomes difficult to repair.
Name the steel sections used for chassis frames
A) Channel section
B) Box section
C) Tubular section
List the different loads on the chassis frame
a. Weight of the vehicle and the passengers.
b. Vertical loads when the vehicle comes across a bump or hollow.
c. Engine torque.
d. Inertia loads due to brake application.
e. Sudden impact loads during a collision.
f. Loads for longer periods e.g., cornering force while taking a turn.
What is the body shell of an automobile?
The body structural assemblies are joined into an integral shell by electric spot welding.
How is the floor assembly of an automobile constructed?
The floor of the body is assembled first, followed by welding the pillars, rails, and panels to form the complete body.
What is the function of the check arm in automobile doors?
Each door is provided with a check arm that prevents the door from opening too far, secured by a rubber pad.
Why are the windshield and back window curved?
To improve visibility.
What are the purposes of body inner trimming in automobiles?
- To reduce mechanical components vibrations. 2. To improve car appearance and comfort.
What does the bench type front seat consist of?
It consists of a metal framing with a stuffed, cloth, and imitation leather upholstered seat back fixed on it.
How is the hood of an automobile designed?
The hood is made in a single piece, hinged at the rear to cover the engine compartment.
What mechanism is used to open and close the deck lid?
The deck lid is opened and closed with the help of a handle, and a catch engages in a striker to keep it closed.
What are the components of automobile bumpers?
The rear and front bumpers consist of a single bar with two ornaments, secured by screws and brackets.
What is the full form of TDC?
Top Dead Center
What is the full form of BDC?
Bottom Dead Center
What do internal combustion engines burn to create motion?
A fuel to create heat which is then used to create motion.
Where does engine torque go through?
The vehicle transmission system.
How can automobile engines be classified?
According to cycle of operation, number of strokes per cycle, fuel used, types of ignition, number of cylinders, arrangement of cylinders, valve arrangement, type of cooling, speed, method of fuel injection, method of governing, application, and special type engine.
What are the types of cycle of operation in automobile engines?
Otto Cycle Engine and Diesel Cycle Engine.
What are the types of strokes per cycle in automobile engines?
Two Stroke Engine and Four Stroke Engine.
What types of fuel are used in automobile engines?
Petrol Engine (or Gasoline Engine), Diesel Engine, and Gas Engine.
What are the types of ignition in automobile engines?
Spark Ignition (SI) Engine and Compression Ignition (CI) Engine.
What are the types of cylinders in automobile engines?
Single-cylinder Engine, Two-cylinder Engine, Three-cylinder Engine, Four-cylinder Engine, Six-cylinder Engine, Eight-cylinder Engine, Twelve-cylinder Engine, and Sixteen-cylinder Engine.
What are the arrangements of cylinders in automobile engines?
Inline Vertical Engine, Horizontal Engine, V-type Engine, Opposed cylinder Engine, and Radial Engine.
What are the types of valve arrangements in engines?
L-head Engine, I-head Engine, F-head Engine, and T-head Engine.
What are the types of cooling in engines?
Air-cooled Engine and Water-cooled Engine.
What are the speed classifications of engines?
Low Speed Engine, High Speed Engine, and Medium Speed Engine.
What are the methods of fuel injection in engines?
Carburettor Engine, Air Injection Engine, and Airless or Solid Injection Engine.
What are the methods of governing in engines?
Hit and miss governed Engine, Qualitatively governed Engine, and Quantitatively governed Engine.
What are the applications of engines?
Stationary Engine, Automotive Engine, Locomotive Engine, Marine Engine, and Aircraft Engine.
What are some special types of engines?
Wankel Engine and Automotive Gas Turbine.
What is the term ‘Bore’ in relation to engines?
The internal diameter of the engine.
What is the term ‘Stroke’ in relation to engines?
Distance travelled by piston in moving from TDC to BDC.
What is ‘Clearance Volume’?
The volume of cylinder above the piston when it is at TDC position.
What is ‘Piston Displacement’?
The volume swept by the piston in moving from TDC to BDC, also called ‘swept volume’.
What is ‘Engine Capacity’?
The total piston displacement or the swept volume of all the cylinders.
What is ‘Compression Ratio’?
The extent to which the charge in the engine is compressed, calculated as the ratio of the volume above the piston at BDC to the volume above the piston at TDC.
What is the term ‘Power’?
The work done in a given period of time.
What is ‘Indicated Horse Power’?
The power developed within the engine cylinders.
What is ‘Brake Horse Power’?
The actual power delivered at the crankshaft, obtained by deducting various power losses in the engine from the indicated horse power.
What is ‘Friction Horse Power’?
The power lost due to friction present between different matching components.
What is the term ‘Torque’?
The force of rotation acting about the crankshaft axis at any given instant of time, expressed in newton-metre (Nm).
What is the relative change in viscosity with temperature called?
Viscosity.
What type of lubricant are vegetable oils?
Liquid.
What type of lubricant is grease?
Semi-solid.
What is the oil filter part of?
Lubrication system.
Define pour point.
The minimum temperature at which the oil will pour is called its pour point.
Give two examples of multi-grade oils.
SAE 20W 40 & SAE 15W 40.
Give two examples of synthetic lubricants.
Grease and refined petroleum oils.
Define viscosity.
It may be considered as the resistance of the lubricating oil to flow.
What is one function of the lubrication system?
It delivers oil to the moving parts of the engine to reduce friction.
List the main parts of an automobile engine that require lubrication.
1) Main crankshaft bearing 2) Big end bearings 3) Gudgone Bearing 4) Piston rings & cylinder walls 5) Timing gear 6) Camshaft and Camshaft bearings.
What are two main functions of the lubrication system?
1) It delivers oil to the moving parts of the engine to reduce friction. 2) It assists in keeping parts cool.
List four properties of good lubricants.
1) Viscosity 2) Physical stability 3) Chemical stability 4) Pour point.
What is viscosity in relation to lubricants?
Viscosity is considered as resistance of the lubricating oil to flow.
What is physical stability in lubricants?
Oil must be stable physically at lowest & highest temperatures.
What is chemical stability in lubricants?
At highest temperature, oil should remain chemically stable.
What does resistance against corrosion mean for lubricants?
Oil should not have any tendency to corrode the pipelines, crankcase & other engine parts which it comes in contact.
Define flash point in relation to lubricants.
Flash point of oil should be high so as to avoid flashing of oil vapour at the temperature.
What does cleanliness mean for lubricants?
Oil should be sufficiently clean and stable itself so that the crankcase and oil lines are kept clean.
What are the types of lubricants based on their state?
1) Solid lubricants such as graphite, soapstone, talc, mica, molybdenum disulphide. 2) Semi-solid lubricants such as greases. 3) Liquid lubricants such as mineral oil, vegetable oils, animal oils. 4) Emulsions such as oil in water.
What are the types of lubricants based on their origin?
1) Natural lubricants such as mineral oils, vegetable oils, animal oils, graphite. 2) Synthetic lubricants such as refined petroleum oils, commercial grade oils, grease.
What are the types of lubricants based on variation in viscosity?
1) Mono-grade oils such as SAE 20, SAE 30, SAE 50. 2) Multi-grade oils such as SAE 20W 40, SAE 15W 40.
What are the types of lubricants based on special preparation?
1) Blended lubricants such as blended by castor oil, palmitic acid, oleic acid. 2) Compounded lubricants such as compounded with polyglycols, fluorocarbons.
What are blended lubricants?
Blended lubricants are made using substances such as castor oil, palmitic acid, and oleic acid.
What are compounded lubricants?
Compounded lubricants are made using substances such as polyglycols and fluorocarbons.
What is the optimum temperature range for engine performance?
The engine gives best performance at a temperature between 70 to 85 degrees.
What is placed between the engine and radiator?
The thermostat is placed between the engine and radiator.
What are the two types of water cooling systems?
1) Thermo-siphon System
2) Pump Circulation System
What is one function of the water pump in the cooling system?
The water pump helps to circulate the coolant through the engine passages, hoses, and the radiator.
What are two advantages of a pressure sealed cooling system?
1) There is no loss of coolant.
2) Cooling efficiency is not decreased at high altitudes.
What are the methods of cooling used in an automobile engine?
1) Air cooling
2) Water cooling
3) Liquid cooling
4) Pressure seal off cooling system
What are four factors for heat dissipation in an air cooling system?
1) Surface area of metal in contact with the air.
2) Flow rate of air.
3) Conductivity of metal used for the engine.
4) Temperature difference between heated surface and air.
What are the components of the cooling system?
1) Radiator
2) Radiator Fan
3) Pressure cap
4) Reserve Tank
5) Thermostat
6) Water Pump
7) Bypass System
8) Freeze Plug
9) Head Gasket
10) Intake Manifold Gasket
11) Hoses
How does the cooling system work?
It works by sending liquid through passages of the cylinder head and cylinder block, carrying heat from the engine.
What is the role of the thermostat in the cooling system?
A thermostat valve is used to keep the coolant at working temperature.
What is the gravity system in fuel supply?
In the gravity system, the fuel tank is mounted at the highest position in motor vehicles.
What is the pressure system in fuel supply?
In the pressure system, a hermetically sealed fuel is used.
What is the function of a fuel feed pump?
A fuel feed pump is used for feeding diesel from the diesel tank to the fuel injection pump.
What are the types of fuel supply systems?
The types of fuel supply systems are gravity feed, vacuum feed, and pump feed.
What are the main constituents of a fuel supply system for an automobile engine?
Fuel tank, fuel lines, fuel pump, fuel filter, air cleaner, carburettor, inlet manifold, and supply & return pipelines.
What are the various fuel supply systems?
Gravity system, Pressure system, Vacuum system, Pump system, Fuel Injection system.
What is a disadvantage of the gravity system of fuel supply?
The gravity system can be less efficient compared to other systems, especially in vehicles with varying terrain.
What is the MPFI system used in automobiles?
The MPFI is a system or method of injecting fuel into an internal combustion engine through multi ports situated on the intake valve of each cylinder.
How is fuel atomized in the MPFI system?
The fuel is atomized by means of an injector nozzle and then delivered into an air stream.
How are fuel injectors configured in the MPFI system?
Separate fuel injectors are used for each cylinder while the mixture under different load and speed conditions is controlled electronically.
What is the pump system used in automobiles?
In this system, a steel pipe carries petrol to the fuel pump which pumps it into the float chamber of the carburetor through a flexible pipe.
How is a mechanical fuel pump driven?
If the fuel pump is mechanical, it has to be driven from the engine camshaft and hence placed on the engine itself.
Where can an electrically operated fuel pump be placed?
An electrically operated fuel pump can be placed anywhere, with the rear location reducing the tendency of forming vapor lock.
What is the gravity system in automobiles?
In this system, the fuel tank is mounted at the highest position in the motor vehicle, allowing fuel to drop into the carburetor float chamber by gravity.
What is a disadvantage of the gravity system?
The rigidity of placing the fuel tank necessarily over the carburetor is a disadvantage.
What is the vacuum system in automobiles?
This system is based on the fact that engine suction can be used for sucking fuel from the main tank to an auxiliary fuel tank, from where it flows by gravity to the carburetor float chamber.
Why is the gravity feed system not used in modern vehicles?
Because we require big tanks for heavy vehicles and we do not find a proper place to fit the tank at a higher level.
What is the purpose of a clutch in a motor vehicle?
The clutch serves to connect or disconnect the engine from the transmission.
What are the different kinds of clutches used in motor vehicles?
- Cone clutch. 2. Single plate clutch or dry disc clutch. 3. Multiplate clutch. 4. Hydraulic clutch.
What is the function of a gear box in an automobile?
A gear box is needed to give an increase to the limited power of the engine in varying road and load conditions.
What are the resistances faced by an auto-vehicle during operation?
- Rolling resistances 2. Gradient resistances 3. Air resistances 4. Resistance due to driving requirements.
What factors affect rolling resistance?
- Material of the road surface: cemented, asphalted, etc. 2. Material and design of tyres tread.
What factors affect gradient resistance?
- Slope of the road: level, steep, down-a-hill, up-the-hill, etc. 2. Mass of the vehicle: light, medium, or heavy. 3. Quality of the road surface: smooth or rough, dry or wet, etc. 4. Inflation (pressure) in the tyre: over-inflated, under-inflated, or correctly inflated.
8) What are the factors that effect air resistance ?
a. speed of the vehicle : slow, medium or fast
b. speed and direction of the wind : in-favour, against the vehicle’s motion or cross-winds
c. body profile of the vehicle : streamlined, bluff body or otherwise
9) What are the factors that effect resistance due to driving requirements ?
a. need of idling, or constant speed
b. acceleration and its rate
c. driving habits
d. frictional resistance
What do you mean by manual transmission ?
The manual transmission i.e., the selective type gearboxes are the conventional means. They are widely
used in cars, buses and trucks. It is also known as standard or conventional type Gear box.
Name the different types of manual transmission .
1) Sliding mesh gear box
2) Constant mesh gearbox
3) Synchromesh gearbox without overdrive
4) Synchromesh gearbox with overdrive
What do you mean by semi- automatic transmission.
Semi-automatic transmission incorporates an intermediate arrangement which is combination of manual
and automatic systems.
Name the types of semi- automatic transmission.
a. Electric controlled with a fluid drive
b. Electric controlled with overdrive
c. Fluid-torque drive
14) What do you mean by Automatic Transmission ?
In automatic transmission, the different ratios between the engine crankshaft and the wheels are
achieved by automatic means.
The driver does not need to shift gears, such transmission make use of a fluid coupling or torque
converter, as well as mechanical, hydraulic or electrical controls.
Types of automatic transmission are
- hydromatic drive 2. Torque - converter drive
