me.2035 ( ice and automobile)

7/27/2019 ME.2035 ( ICE and Automobile)

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TU(Hmawbi) [email protected] 01-620072,620454, 09-5030287

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1. The vehicle all main operating components are

(a) Frame or body shell-farms the skeleton of the vehicle.

(b) Engine-acts as the power unit.

(c) Transmission conveys the drive to the wheels.

(d) Suspension absorbs road shocks.

(e) Steering controls the direction of movement.

(f) Brakes slow down the vehicle.

(g) Electrical equipment provides.

2. The transmission system applies to the components needed to transfer the drive from

the engine to the road wheels the main components are .

(a) cloth - to disengage the drive

- to provide a smooth take-up of the drive.

(b) Gear box - to increase the turn effort applied to the driving road wheels.

- to enable the engine to operate within a given range of speed

irrespective of the vehicle speed.

- to give the reverse motion of the vehicle.

- to provide a neutral position so that the engine can run without moving

the vehicle.

(c) Final drive - to turn the drive through 90

- to reduce the speed of the drive by set amount to match the engine to

the vehicle.

(d) Differential - to allow the inner driving road wheel to rotate slower than the outer

wheel when the vehicle is cornering, whilst at the same time it ensures

that a drive is applied equally to both wheels.

(20 marks)

Cha: 1 Q-4

3. (a) B-chassis

(b) B-suspension

(c) A-diesel

(d) A-clutch

(e) Differential (10 marks)

Cha: 1 Q-4


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4. (a) Very thin, soft, steel sheet which is pressed in to various shapes and welded together

to form a very rigid

(b) Transmission

(c) Suspension

(d) brake

(e) Steering (15 marks)

Cha: 1 Q-2

5. The purpose of a clutch on cars with manual transmission that are shifted by hand. It

allows the driver to couple the engine to or uncouple the engine from the transmission. The

clutch is linked to the clutch pedal in the passenger compartment. When the driver presses

down on the clutch pedal, the linkage causes the clutch to disengage. This uncouples the

engine from the transmission. When the driver release the clutch pedal, spring in the clutch

cause it to engage again. Now power can flow from the engine, through the clutch, to the

transmission and power train.

(20 marks)

Cha: 1 Q-4

6.

The construction of the clutch, shown in Figure. Basically the clutch consists of three

parts. These are the engine flywheel, a friction disk, and a pressure plate.

The coil spring clutch has a series of coil springs set in the circle as shown in figure.

The first disk, or driven plate, is shown in figure. It consists of a hub and a plate, with facing

attached to the plate. The friction disk has cushion springs and dampening springs. The


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cushion springs are slightly waved, or curled. The cushion springs are attached to the plate,

and the friction facing is attached to the springs.

(20 marks)

Cha: 1 Q-4

7.

Operation of a typical clutch

When the engine is running, the flywheel is rotating. The pressure plate is attached to

the flywheel so the pressure plate also rotates. The friction disk is located between two. When

the clutch is released show in Figure 1 engage.

The driver has pushed down on the clutch pedal. This action forces the pressure plate

to move away from the friction disk. There are now air gaps between the flywheel and the

friction disk, and between the friction disk and the pressure plate. No power can be

transmitted through the clutch. When show is Figure 2 disengage.

When the driver release the clutch pedal, power can flow through the clutch. Spring in

the clutch force the pressure plate against the friction disk. This action clamps the friction

disk. This action clamps the friction disk lightly between the flywheel and the pressure plate.

Now the pressure plate and friction disk rotate with the flywheel. The friction disk is

assembled on a spindle shaft that carries the rotary motion to the transmission.

(20 marks)

Cha: 3 Q-5

8. The hydraulically operated clutch linkage is used when the clutch is located so that it

would be difficult to run rod or cable from the foot pedal to the clutch. This type if the


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linkage is also used on high out put engine which require heavy pressure plate springs. When

a clutch is designed to transmit high torque, strong springs are used to provide sufficient force

on the friction disk. With insufficient force, the pressure plate and flywheel would slip on the

friction disk.

However, heavy spring force increases the force that must be applied to the clutch

fork. This is turn, increases the force at the driven must apply to the clutch pedal. To reduce

the force required to operate the clutch pedal. To reduce the force required to operate the

clutch pedal, the hydraulic system is used.

(20 marks)

Cha: 3 Q-9

9. The purpose of the over drives in the transmission at intermediate and high car speed.

Because in the transmission system the high gear position produces 1:1 ration between the

clutch gear and the transmission output shaft. This is direct drive. There is neither gear

reduction nor gear increase through the transmission.

At intermediate and high car speeds, it have the transmission output shaft turn faster

than the clutch gear and engine output shaft. So transmission is in over drive when the

transmission output shaft is turning faster than the transmission in put shaft or clutch gear.

(15 marks)

Cha: 4 Q-3

10.

The operation of the three speed transmission shown in figure first gear position. The

clutch is depressed thus releasing the clutch disk. The input shaft and cluster gear will stop

turning. The out put sliding low gear is shift forward and meshed with the cluster gear. The

clutch engage. Input shaft will turn the cluster gear. The cluster gear will revolve at a slower

speed.


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Second gear position shown in figure. When ready for second gear. The clutch is

depressed thus breaking the flow of power from the engine. The low sliding gear is moved to

the neutral position and the sliding gear is meshed with the cluster second gear. The clutch is

then released and the power flows to the out-put shaft.

Third gear position shown in figure. When the car attains sufficient speed, the clutch

is depressed. The sliding second gear is moved forward until the spine recess has slipped over

the spline stub on the put shaft. The input and output shaft are locked together the spline slub.

This gives direct drive through the transmission.

Reverse gear position shown in figure. The sliding third gear is placed in the neutral position.

The low reverse sliding gear is move back until it engages the reverse idler gear. As the


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reverse idler is revolving in the same direction as the in put shaft, it will impart a reverse

rotation to the output shaft.

(20 marks)

Cha: 4 Q-4

11. Synchronizer is a device in the transmission, that synchronizer gear about to be

meshed. So that no gear clash will occur.

(5 marks)

Cha: 4 Q-5

12. The gear oil has five jobs to do in the gear box.

These are

(a)To lubricate all moving parts and prevent wear.

(b)

To reduce friction and power loss.

(c)To protect against rust and corrosion.

(d)

To keep the interior clean.

(e)To cool the gear box.

13. The basic difference between the drive lines for rear wheel drive and front wheel

drive vehicle.

First position is rear wheel drive vehicles, it have a long drive line or shaft extending from the

transmission at the front to the differential at the rear show in Figure.


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Second position is front wheel drive shown in figure. Front wheel drive vehicle usually have

the engine transaxle assembly mounted side ways. Thy have short drive shaft extending from

the transaxle to the front wheel.

(20 marks)

Cha: 6 Q-3

14.

The purpose of the drive line are used for rear wheel forward are reverse driving.

Engine is running, when the rotary motion of the transmission out put shaft is carried

to the differential and from there to the wheels. First, the engine are transmission are more or

transmission out put shaft is carried to the differential and from to the wheels. First, the

engine and transmission are more or less rigidly connected to the car body. Second, the rear

arcle housing is attached to the car body or frame through springs. This means two things:

1.

The drive line must change in length as the wheels move up and down.

2. The angle of drive must change as the wheels move up and down.

To allow for these variations, two different kinds of joints are necessary. The drive

must include two or more universal joints and a slip joint. The universal joints take care of

the change in drive angle. The slip joint takes care of the change in length. The propeller

shaft is transmits full engine power from the gear box to the differential. One end of the shaft

is connected to the gearbox while the other is connected to the differential in the rear axle

assembly in the front engine rear wheel drive.

(20 marks)

Cha: 6 Q-4


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15. Drive shaft

The universal joint allows driving power to be carried through two shafts that are at a

varying angle. The sample diagram is as shown in figure. It is a double hinged joint

consisting of two Y. shape yokes and a cross shape member called the spider. One of the

yoke is on driving shaft. The four arms of the spider connect there drive shaft yoke and. The

driving shaft and yoke case the spider to rotated. The other two turnings of the spider cause

the driven shaft to route. When the two shafts are as an angle to each other the bearing in the

yokes permit the yokes to swing around on the turning with each revolution.

(20. marks)

Cha. 6.Q.3

16.

The construction and purpose of the slip joint is as shown in figure. The slip joint has

outside splines on one shaft and matching internal splines on a matching hollow shaft. The

splines cause the two shafts to rotate together but permit the two to move endwise in relation

to each other. This allows changes in length of the drive shaft as the rear axle moves toward

or away from the car body or frame.

(20 marks)

Cha.6. Q.6


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17.

The construction and operation of a differential are as shown in figure. The

differential main parts of include.

1.

drive pinion

2. Ring gear

3.

differential case

4. differential side gear

5.

differential bevel gears

One the inner end of each axle is a small bevel gear called a differential side gears.

When any two bevel gear are put together so that their teeth mesh. The driving and driven

daft can be at a 90angle. The driving pinion is on the propel as shaft. It transmits engine

power to the ring gear. When the car, differential pinion gear and two differential side gears

all turn as unit. The two differential pinion gears do not rotate on the pinion shaft. This is

because they exert equal force on the two differential side gears. As a result the side gear turn

at the same speed as the ring gear which causes both drive wheels to turn as the same speed

also. However, when the car beings to round a curve, the differential pinion gears rotate on

the pinion shaft. This permits the outer wheel to turn faster than the inner wheel. (20. marks)

18.


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Limited slip differential operation at shown in Figure. The standard differential

delivers the same amount of the torque to each rear wheel. When both wheels have equal

traction. When one wheel have less traction than the other. For example, when one wheel

slips on ice the other wheel cannot deliver torque. All turning effort goes to the slipping

wheel. To provide good traction even through one wheel is slipping, a limited-slip differential

is used in many. It has some of preventing wheel spin and loss of traction. The standard

differential delivers the maximum torque to the wheel with maximum traction. The limiting

slip differential delivers the maximum torque to the wheel with maximum traction.

(20 marks)

Ch. 7. Q. 4

19.

Three types of hubs are used on the front wheels of four-wheel drive vehicles. These

are.

1. manual locking hub

2. automatic looking hub with manual over drive

3. the hub used with full time four wheel drive (6 marks)

Ch. 7. Q. 5

20.

(a) The differential

(b) The inner rear wheel during a town

(c) The limited slip differential

(d) Locking hubs

(e) The manual locking hub, the automatic locking hub with manual over-drive and the

hub used with full time pour wheel drive.

(15 marks)

Cha: 7, Q. 2

21. The basic type of spring used in automobiles in three types. These are leaf, coil and

torsion bar. In additional, air suspension system is used in some cars and buses.

Spring are used in various ways to achieve satisfactory ride quality and control. For

example, torsion bars are used in two ways. Coil springs are used in four ways the greatest

variety of spring arrangements is fount suspension system. (10 marks)

Cha: 8, Q- 3


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22. Several types of front suspension systems are ..

(a) Coil spring between lower control arm and a seat in the car frame.

(b) Coil spring between a seat on a street rood which is attached to the lower control arm

and a seat in the car spring

(c) Coil spring between an I-beam axle and a seat in the frame.

(d)

Coil spring between a seat on a strut rod which is attached to the lower control arm

and a seat in the car-body.

(e)

Torsion bar connected longitudinally between the lower control arm the car frame.

(f)

Torsion bar connected transversely between the lower control arm and the car body.

(g)

Leaf spring between an I- beam axle and a seat in the frame.

(20 marks)

Cha:8, Q.4

23.

The purpose of the shock absorber are necessary because spring do not settle down

fast enough. After a spring has been compressed and released it continues to shorten and

lengthen, or oscillate, for a time. the shock absorber absorbs the shock of the wheel meeting a

bump or hole. As soon as the wheel passes the hole or bump, the shock absorber returns the

wheel to contact with the road. This prevents the wheel from bouncing.

The shock absorbed construction and operation of shown in figure.

The shock absorber is the direct-action tubular or telescope type. In operation, the

shock absorbers lengths and shorten as the wheels meet irregularity in the road. As they do

this, a piston inside the shock absorber moves in a cylinder filled with fluid. Therefore the


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fluid is put under high pressure and forced to flow through small opening. The fluid can only

pass through the opening slowly. This slows the piston motion and restrains the spring action.

(20 marks)

Cha: 8 Q-5

24. The operation of automatic level control system is shown in figure.

The operation of automatic level control system takes care of changes in the load at

the rear of the car. In a car with out automatic level control, adding weight at the rear will

make the rear end of the car squat. This changes the handling characteristics of the car. It also

causes the headlights to point upward. The automatic level control prevents this automatically

raising the rear end of the car to level when a load is added. The system also automatically

lowers the rear end of the car to level when the load is removed.

The automatic level control system includes a compressor, an air reserve tank, a

height control valve, and two special shock absorbers with built-in air chamber.

(20 marks)

Cha: 8 Q-6

25. The purpose of the steering system is allows the driven to guide the car along the road

and turn left or rights as desired.

The steering system construction and operation of shown in figure. The system

include the steering wheel, which the driver controls, the steering gear, which changes the

rotary motion of the wheel into straight line motion and the steering linkages. Steering

knuckle attached to tie rods. Relay rod is straight line motion by pitman arm and steering gear.


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The tie rod joint at each wheel permit the steering knuckle to swing from side to side. This

movement turns the front wheels left or right so that the car can be steered.

(20 marks)

Cha: 9 Q-3

26. The various factors that enter into front end geometry are.

(a) Front suspension height

(b) Camber

(c) Steering axis inclination (S.A.I)

(d) Caster

(e) Toe

(f) Turning radius

(a) Front suspension height is the distance measured from some specific point on the

body, fame of suspension to the ground.

(b) Camber is the tithing in or out of the front wheels from the vertical when viewed

from the front of the vehicle.

(c) Steering axis inclination,

The steering knuckle is supported through ball joints by upper and lower control

arms. A line drawn through the centre of the ball joints is called the steering axis

inclination.

(d) Cast is the angle formed by the forward or rearward till of the steering axis from

the vertical when viewed from the side of the wheel.

(e) Joe is the amount in inches, millimeters or degrees by which the front wheels point

inward or outward.

(f) Turning radius is the difference between the two angles formed by the front wheels

the car frame during town than the inner wheel is following the radius of a smaller

circle than the outer wheel.

(20 marks)

Cha: 9 Q-4


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27.

The rack and pinion manual steering gear construction of shown in figure. It is

simpler, more direct action and may be straight mechanical operation. Set apart from the rest

of the car. As the steering wheel and shaft are turned, the rack moves from one side to the

other. This pushes or pulls on the tie rods, forcing the wheel spindles to pivot on their ball

joints. This turns the wheels to one side or the other so that the car is steered.

(20 marks)

Cha: 9 Q-5

28. The purpose of power steering is to reduce the driver effort at the steering wheel turn

on left or right, vary easy.

Power steering system construction of shown in figure. The hydraulic power steering

comprises of


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(i) A fluid reservoir

(ii) Hydraulic pump

(iii) Hydraulic ram with a fixed length piston rod

(iv) Hydraulic control valve

(v) Steering shaft

(vi) Steering box

(vii) Steering wheel

In the basic system of power assisted steering, the booster is set into operation when

the steering shaft is turned. Then after the steering effort exceeds a cartain force, the booster

takes over and provides most of the force required for steering.

(20 marks)

Cha: 9 Q-7

29. The construction of a dual brake system uses a two-piston master cylinder as shown in

figure.

One brake line from the master cylinder goes to one set of wheel brakes. The other

brake line from the master cylinder goes to the other set of wheel brakes.

The dual braking system includes a pressure-differential valve. The value has switch

contacts that are held open by equal pressure in both sections of the hydraulic system. If one

section begins to leak, the pressure in that section will drop. Than the pressure differential

valve will connect the instrument panel warning light to driver of brake trouble, and that the

brake system should be service at one. although the other section of the dual braking system

can provide emergency braking. The car is not safe to drive.

(20 marks)

Cha: 10 Q-3

30. The operation of drum brakes shown in figure. When the driven pushed the brake

pedal down. Brake fluid is forced from the master cylinder.


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32. The purpose of the parking brake holds the car stationary while it is parked. Since the

parking brake is independent of the service brakes, it can be used as an emergency brake if

the service brake fail. When the parking brake is operate by a hand lever, some manufactures

call it the hand brake. (20 marks)

Cha: 10 Q-6

me.2035 ( ice and automobile)

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