Vehicle structure - csvtu Mech 7th- Automobile Engg.
- 1. Part 1 Manish RK Sahu Asst. Professor Department of Mechanical Engg. 27/08/2020 1
- 2. Contents Introduction Type Of Automotive Vehicles General Layout Vehicle Construction-chassis, Frame And Body Types Of Chassis 27/08/2020 2
- 3. Introduction What is an ‘Automobile’?? • A self propelled vehicle used for transportation of goods & passengers on the ground is called an Automobile. • Different from Aeronautical vehicles (planes, helicopters, rockets) & marine vehicles (ships, boats, submarines) 27/08/2020 3
- 4. Classification of Automobiles • 1 . Purpose • Passenger Carriers – Car, Bus • Goods Carriers - Trucks • 2 . Fuel Used • Petrol • Diesel/ Gas • Electric • Steam – not in use • 3 . Capacity • HMV – Trucks, Buses • LMV – Tempo, Jeeps • • • 27/08/2020 4
- 5. Classification of Automobiles 4. Construction • Single unit • Articulated – Eg. Trailers, Tractors 5. Drive (Steering) • Left hand • Right Hand 6. Number of Wheels • Two Wheeler • Three Wheeler • Four Wheeler • • • 27/08/2020 5
- 6. Classification of Automobiles • • • 7. Body • Hatchback • Sedan • Convertibles • Station Wagons – Vans • Special Purpose Vehicles – Ambulance, Fire Brigade vehicle, SUV 8. Drive • FWD • RWD • AWD 27/08/2020 6
- 7. Vehicle Layout Engine Transmission Drive Shaft Final Drive 27/08/2020 7
- 8. Main Components of Automobiles • • • 1. Engine or Power Plant 2. The Chassis and Frame 3. The Transmission 4. The Body and Controls. 5. Accessories 27/08/2020 8
- 10. • • • Engine SI – Spark Ignition CI – Compression Ignition Two Stroke Four Stroke 27/08/2020 10
- 13. • • • Types of Chassis A. According to layout • Conventional • Forward • Semi forward B. According to mounting of engine and transmission • Engine at front • Engine fitted at the center of the chassis • Engine fitted at the back 27/08/2020 13
- 14. • • Types of Chassis C. According to mounting of components of Chassis • Front Engine Rear Wheel Drive • Front Engine Front Wheel Drive • Rear Engine Rear Wheel Drive • All Wheel Drive 27/08/2020 14
- 15. • • 1.Conventional Chassis • Engine is fitted in front of the driver cabin or driver seat such as in cars. • Chassis portion can not be utilized for carrying passengers and goods • Heavy Engine can be fitted, which can be used to give more power. 27/08/2020 15
- 16. • • 2. Semi Forward Chassis • Half portion of the engine is in the driver cabin half is outside the cabin such as in Tata trucks / & and remaining Tempos • In this arrangement a part of the chassis is utilized for carrying extra passengers 27/08/2020 16
- 17. • • 3. Forward Chassis • Complete engine is mounted inside the driver cabin, Driver seat is just above the front wheel. • More Boot Space Available as full utilization of chassis 27/08/2020 17
- 18. • • 4. Engine at front Conventionally the engines are fitted at front and drive is given to the wheels from the rear. Advantages • Enough space is available for luggage behind the rear seat • The weight of vehicles is well balanced. • Increased cooling efficiency. 27/08/2020 18
- 19. • • 4. Engine fitted at the Centre 27/08/2020 19
- 21. • • 6. Engine fitted at Back • Flat floor is available since long propeller shaft is eliminated. • The centre of gravity is lowered giving stable driving. • Better adhesion on road when climbing hill. 27/08/2020 21
- 22. 27/08/2020 22
- 24. Front Engine Rear Wheel Drive 27/08/2020 24
- 25. Front Engine Rear Wheel Drive • Most common type of layout. • Engine Located at front and driving power is Given to rear wheels. • Driving Power flows from engine to rear wheel through various mechanical linkages. 27/08/2020 25
- 27. Even weight distribution • The division of weight between the front and rear wheels has a significant impact on a car's handling, and it is much easier to get a 50/50 weight distribution in a rear wheel drive car. Steering radius • As no complicated drive shaft joints are required at the front wheels, it is possible to turn them further that would be possible using front wheel drive, resulting in a smaller steering radius. 27/08/2020 27
- 28. Less load at front axle • The driving force is given at rear axle hence there is no need to provide complex design on front axle. Effective Cooling of the engine due to exposure of cooling system to flowing air 27/08/2020 28
- 29. Disadvantages Decreased interior space – This isn't an issue in a vehicle with a ladder frame like a pickup truck, where the space used by the drive line is unusable for passengers or cargo. But in a passenger car, rear wheel drive means: Less front leg room (the transmission tunnel takes up a lot of space between the driver and front passenger), less leg room for center rear passengers (due to the tunnel needed for the drive shaft), and sometimes less trunk space (since there is also more hardware that must be placed underneath the trunk). 27/08/2020 29
- 30. Less Inner space 27/08/2020 30
- 31. Increased weight • The drive shaft, which connects the engine at the front to the drive axle in the back, adds weight. There is extra sheet metal to form the transmission tunnel. A rear wheel drive car will weigh slightly more than a comparable front wheel drive car, but less than four wheel drive. 27/08/2020 31
- 32. Higher purchase price • Due to the added cost of materials, rear wheel drive is typically slightly more expensive to purchase vehicle. . than a comparable front wheel drive 27/08/2020 32
- 33. Front Engine Front Wheel Drive Engine Transmission Final Drive 27/08/2020 33
- 34. Front Engine Front Wheel Drive • In this type the engine is mounted on the front side of the vehicle and the driving power is given to the front wheels only. The power flows from engine to front axle. • • 27/08/2020 34
- 35. Advantages • Interior space: • Since the powertrain engine compartment is a single unit contained in the of the vehicle, there is no need to devote interior space for a driveshaft tunnel or forrear differential, increasing the volume available passengers and cargo. Inner SPACE Engine 27/08/2020 35
- 36. Better handling on slippery surface • Slippery-surface traction: placing the mass of the drivetrain over the driven wheels improves traction on wet, snowy, or icy surfaces. Improved drive train efficiency • The direct connection between engine and transaxle reduce the mass and of the drivetrain compared to mechanical inertia a rear-wheel drive vehicle with a similar engine and transmission, allowing greater fuel economy. 27/08/2020 36
- 37. Disadvantages • Less Turning Radius • The drive shafts may limit the amount by which the front wheels can turn. • More Weight on front results in rapid wear of front tires. • Front-wheel drive has worse acceleration than rear- wheel drive, which is why most sporty and race cars use rear-wheel drive. 27/08/2020 37
- 38. Steering AWD FWD VS RWD VS 27/08/2020 38
- 39. FWD VS RWD 27/08/2020 39
- 40. Rear Engine Rear Wheel Drive 27/08/2020 40
- 41. 54 27/08/2020 41
- 42. Advantages • Weight over rear wheels, increased traction while accelerating. • Front axle construction is simplified. • Absence of propeller shaft results in decrease of floor height. • Engine components mounted at rear of rear axle hence more space is available. 27/08/2020 42
- 43. Disadvantages • Separate cooling mechanism is needed for effective cooling mounted at rear. of the engine as the engine is • More load on rear side may result in overturning (Over steer) of the vehicle. • Longer linkages are required to operate clutch, gears from driver. 27/08/2020 43
- 44. All wheel Drive 27/08/2020 44
- 45. AWD or 4WD All wheelsAlways engaged. Safe and advantageous over 4WD 4 wheels can be engaged only in difficult terrain. In normal condition power is given to rear wheels only. 27/08/2020 45
- 46. Advantages • 4WD improves traction in dangerous driving conditions, such as snow, make ice, rocks, and other scenarios that can control difficult. By engaging both sets of wheels, traction and control improves. • Additional weight contributes to better grip on the road. • 4WD is great for those who like off-roading. 27/08/2020 46
- 47. Disadvantages • The main disadvantage of 4WD is added cost for purchase, maintenance, and fuel. The extra equipment (differentials, transfer case, etc.) adds complexity and weight to the vehicle, increasing initial market value, tire wear, and the cost of repairs and maintenance. The added power and weight of 4WD and AWD systems requires more fuel, making them less efficient than their 2WD counterparts. Added weight improves traction and control, but it also increases the braking distance required to make a complete stop. Lighter vehicles can avoid collision easier than heavier vehicles. • • 27/08/2020 47
- 48. Key component of Chassis is Frame Frame Have 3 different types 1. 2. 3. Conventional frame Integral Frame Semi Integral Frame Functions of Frame - • To support chassis components & body • T o Withstand the static & dynamic load of different components of chassis • To withstand load of the body • To carry load (External) • To withstand stresses caused due to uneven road conditions. • To withstand force caused due to turning of the vehicles & sudden braking or acceleration. Frame
- 49. Conventional Frame (Ladder Frame)
- 51. Channel Section – Good Resistance to bending Box Section – Good Resistance to both bending and torsion Tubular Section – Good Resistance to torsion. Frame Cross Sections
- 52. Integral Frame • In this type of construction, there is no frame. It is also called unitized frame-body construction. • All the assembly units are attached to the body and all the functions of the frame carried out by the body itself. • Here the body shell and underbody are welded into single unit. The underbody is made of floor plates and channel and box sections welded into single unit. This assembly replaces the frame. • This frame is used now a days in most of the cars. Due to elimination of long frame it is cheaper and due to less weight most economical also. • Only disadvantage is repairing is difficult.
- 53. Integral Frame
- 54. Semi Integral Frame • In some vehicles half frame is fixed in the front end on which engine gear box and front suspension is mounted. • In this case the rubber mountings used in conventional frame between frame and suspension are replaced by more stiff mountings. • Because of this some of the vehicle load is shared by the frame also. This type of frame is heavier in construction. • It has the advantage when the vehicle is met with accident the front frame can be taken easily to replace the damaged chassis frame. • This type of frame is used in some of the European and American cars.
- 57. l Tubular Frame It is a 3 D Design. Tubular space frame chassis employs dozens of circular section tube, positions in different directions to provide mechanical strength These tubes are welded and forms very complex structure.
- 58. l Monocoque • Monocoque is a one-piece structure which defines overall shape of the car. while ladder, tabular & backbone provide only stress members. • Today 99% car produced in this planet are made of steel Monocoque chassis. • Chassis are made by welding of Several pieces. (Spot Welding ) • Monocoque is made of steel.
- 59. l Back Bone Frame Similar to Body Frame Structure It consists of strong tubular backbone (Usually Rectangular in cross section) A body is placed on the structure. Used in numerous sports cars.