BE (Seventh Semester) – Mechanical Engineering
Automobile Engineering – 337711(37) – Summer Session – 2011
UNIT – I
1. Name the major components of an automobile? 2 marks
2. Draw the layout of chassis of a four wheel driven automobile and explain briefly? 7 marks
3. What are the functions of suspension in a motor vehicle? With the help of neat sketches explain the function and working of : 7 marks
Leaf springs
Torsion bar
4. Explain briefly the purpose of a shock absorber? Write the working of telescopic shock absorber giving suitable sketch? 7 marks
UNIT – II
1. What is the functions of a clutch? 2 marks
2. Derive expressions for effective mean radius and torque transmitted in case of a single plate clutch assuming : 7 marks
Uniform pressure
Uniform wear
3.Explain by means of a neat sketch the construction of a fluid flywheel and write the principle of torque transmission in the same. 7 marks
4. A truck employs a single plate dry friction type clutch and develops maximum engine output of 88.3 KW at 2800 rpm. The ratio of inside diameter of the clutch plate to outside diameter is 0.6. The intensity of pressure on the clutch facing, of coefficient of friction 0.35, is not to exceed 230 kPa. Assuming that the clutch does not slip even after a loss of 25% of engine torque due to wear of clutch facing, determine : 7 marks
The size of the clutch plate
Mean effective radius of the clutch
Frictional area
UNIT III
1. What do you mean by gear ratio? What is the significance of low and high gear ratios? 2 marks
2. Sketch and explain the construction of a sliding mesh gear box. Show power flow path in top gear, second gear and reverse gear? 7 marks
3. Draw the schematic of torque converter? State the principle, advantages & disadvantages? 7 marks
4. A truck of weight 48 KN is to travel on an upward road grade of 17% at 45 km/hr in second gear. Its frontal cross sectional area is 5.1 m² and effective radius of the wheels is 420 mm. If transmission efficiency in second gear is 83%, coefficient of rolling resistance and sir resistance are 0.017 and 0.044 respectively, then calculate : 7 marks
Minimum power required in the engine at 2500 rpm
The gear into in second gear
Maximum speed of the vehicle in top gear on level road at the same engine speed
Gear ratio in top gear
The reduction ratio at final drive (differential) is 4.2 and transmission efficiency in top gear is 92%. Neglect road friction resistance.
UNIT IV
1. Write the function of differential? 2 marks
2. What are the different types of real axle drive? Write any one with neat sketch? 7 marks
3. Mention desirable tyre properties. State the advantages of tubeless tyre over conventional tubed tyre? 7 marks
4. A motor car has a wheel base of 264 cm, the height of its CG above the ground is 0.61 m and it is 112 cm in front of the rear axle. If the car is travelling at 40 km/hr on a level track, determine the minimum distance in which the car may be stopped, When: 7 marks
The rear wheels are braked
The front wheels are braked
All wheels are braked
The coefficient of friction between tyre and road may be taken as 0.6.
UNIT V
1. Differentiate between under steer and over steer? 2 marks
2. Give the definition, effect and amount of the following steering geometry : 7 marks
Camber
King pin inclination
Caster
Toe in and toe out