Sunday, 29 November 2015

What is meant by Full elliptic leaf springs?


                        The advantage of this type is the elimination of shackle and spring. The lubrication and wear frequently which are on of the main draw back of this type of springs.

Types of Leaf Springs?

Types of suspension springs?


1. Steel Springs : 
                         a. Leaf Springs
                         b. Coil Springs
                         c. Torsion bar Springs
 2. Rubber Springs: 
                         a. Compression Springs
                         b. Progressive Springs
 3. Plastic Springs
 4. Air Springs:
                       a. Bellow Type
                       b. Pestoon Type
 5. Hydraulic Type

Types of front Independent suspension system?

What are the basic suspension movements?

1. Bouncing:
                   The vertical movement of the complete body.

2. Pitching: 
                 The rotating movement of all the parts between the spring and road and the portion of spring weight itself.

3. Rolling: 
                The movement about longitudinal axis produced by the centrifugal force during cornering.

What is meant by Sprung Weight and un Sprung Weight?


Sprung Weight:
                             It is weight of all the parts supported by the spring including weight of the spring.

Un sprung weight:
                             It is the weight of all the parts between the spring and rod and the portion of spring weight it self.

Advantages of Suspension system?


1. It provides softer suspension.

2. It reduces wheel wobbling.

3. It reduces the tendency of fitting of the wheel on one side due to road vibration.

4. It provides more space for engine accommodation.

5. It promotes under steer which results low un sprung weight.

6. The movement of the spring on one wheel is not transmitted to the other wheel.

What is meant by Independent suspension system?




                        The independent suspension system means any arrangement that connects road wheels to the frame in which raise or fall of the wheel has no direct effect on the other wheel. It eliminates wheel wobbling

What are the main Components of Suspension system?

               




    That are the very main components of suspension system.


Thursday, 26 November 2015

What are the Functions of suspension system?

1. It prevents the vehicle body and frame from road shocks.

2. It gives stability of the vehicle.

3. It safeguards the passengers and goods from road shocks.

4. It gives the good road holding while driving, cornering and braking.

5. It gives cushioning effect.

6. It provides comfort.

Advantages of air brake?



1. This system used in heavy vehicles because they are more powerful than hydraulic or mechanical brakes.
2. It simplifies the chassis design
3. The compressed air is used for purposes like tyre inflation; for horn, windscreen wiper etc.

What is meant by Air Brake System?





              The air brake system consists of two-stage air-compressor driven by the crankshaft or gearbox shaft. It takes air from atmosphere, compresses it and delivers to the air reservoir through un-loader valve. Where the pressure of the reservoir reaches the maximum degree, the un- loader valve opens to the atmosphere. Then the compressed air is directed in to the atmosphere directly.

What is meant by WHEEL CYLINDER?

                   Wheel cylinder is the second important hydraulic brake system. It consists of two pistons which can move in opposite directions by the fluid pressure. It is rigidly mounted on the brake shield or backing plate. The boots protect the cylinders from foreign substances. Bleeder valves are provided in the cylinder to permit air and liquid to be pumped out of the system during of the bleeding operation . Piston cup fits tightly in the cylinder against each piston and seal themechanism against leakage of the brake fluid. A Spring serves to hold the cups against the piston when the pressure is decreased. When the brakes are applied the brake fluid enters the cylinder from a brake line connection inlet between the two pistons. It causes to force out the two pistons in opposite directions. This motion is transmitted to the brake shoe. Directly or through links force them against the brake drum, thus applying the brake.

Wednesday, 25 November 2015

What is meant by master cylinder in braking system?

Master Cylinder:

                         The Master Cylinder is the heart of the hydraulic brake system. It consists of two main chambers. The fluid reservoir which contains the fluid to supply to the brake system, and the compression chamber in which the piston operates. The reservoir supplies fluid to the brake system through two ports.

Main components of drum brakes?


1. Brake drum

2. Back plate

3. Brake shoes 

4. Brake Liners

5. Retaining Springs

6. Cam

7. Brake Linkages

What are the Types of Mechanical Brakes?


a. Drum Brakes (Internal Expanding or External Contracting)

b. Disc Brakes (Single or Two caliper)

What are the Classification of Brakes?

1.By method of power
a) Mechanical brakes
b) Hydraulic brakes
c) Vacuum brakes
d) Air brakes
e) Electrical brakes
f) Magnetic brakes
g) Air assisted hydraulic brakes

2.By method of application:
 a) Service or foot brakes
 b)Parking or hand brakes

3.By method of operation: 
a) Manual
b) Servo
c) Power operation

4. By method of Braking contact 
 a. Internal Expanding Brakes
b. External Contracting Brakes.

5. By Method of Applying Brake force:
a. Single Acting Brakes.
b. Double Acting Brakes.

What are the Requirements of Automobile Brakes?


1.It should work efficiently irrespective of road condition and quality.

2.The retardation must be uniform throughout its application.

3.The pedal effort must be within the convenient capacity of the driver.

4.It must be reliable and should not be effected by heat water and dust.

5.It should be in minimum weight.

6.It should have long life.

7.It should be easy to maintain and adjust.

8.Noise and vibrations are to be minimum.

9.There should be provision for secondary brake or parking brake.

What are the function of brake?


1.It is used to stop the vehicle.

2.It is used to control the speed where and when required.

3.It is used to control the vehicle while descending along the slope.

4.To park the vehicle and held it in stationary position without the presence of Driver.

what are the steering defect occurs?

What is meant by Irreversible steering?


                          If the front road wheels does not transfer any deflection to the steering which is called irreversible steering. After negotiating a curve and the steering wheel not returned easily, there causes the production of undue stresses on the steering mechanism, therefore some degree of irreversible also desired.

What is meant by Toe in and Toe out?

Toe-in:
            It is the amount in minimum at the front part of the wheel points inwards approximately 3 to 5 mm. It prevents side slipping excessive tyre wear, proper rolling of front wheels and steering stability.


Toe-out:
             It is the difference in angles between two front wheels and vehicle frame during turning. It is used to prevent dragging of tyre during turn.

what is meant by King-pin inclination?

                       It is the angle between vertical line to the king pin axis. The inclination tends to keep wheels straight ahead and make the wheels to get return to the straight position after completion of a turn. The inclination is normally kept 7º to 8º.

what is meant by camber?


The angle between wheel axis to the vertical line at the top is called camber angle. It is approximately ½Âº to 2º.

What is meant by Caster Angle?



                    This is the angle between backward or forward tilting of the king pin from the vertical axis at the top. This is about 2º to 4º. The backward tilt is called as positive caster. The forward tilt is called negative caster.

what are the Factors effects the wheel alignment?


1. Factors pertaining to wheel:-

         a. Balance of wheels(Static and Dynamic)

         b. Inflation of tyre.

         c. Brake adjustments.

2. Steering Linkages.

3. Suspension System 

4. Steering Geometry –a. caster b. camber c. king pin inclination d. toe-in and toe-out etc., Steering Geometry: It refers to the angular relationship between the front wheels and parts attached to it and car frame. The steering Geometry includes

       a. Caster angle

       b. Camber angle

       c. King-pin inclination

       d. toe-in 5. toe-out etc.,

What are the Types of steering Linkages?


1. Conventional steering Linkage.

2. Direct cross type steering linkage

3. Three piece steering linkage

4. center arm steering linkage

5. Relay type steering linkage

What are the Functions of Steering Gear Box?



1. It converts the Rotary movement of the steering wheel in to the angular turning of the front wheels.

2. It also multiplies drivers efforts and give MECHANICAL ADVANTAGE

Types of Steering Gear Boxes?


1. Worm and Wheel Steering Gear.

2. Worm and Roller Steering Gear.

3. Re-circulating Ball type Steering Gear.

4. Rack and Pinion type Steering Gear.

5. Cam and Roller Gear type Steering Gear.

6. Cam and Peg Steering Gear.

7. Cam and Double lever Steering Gear.

8. Worm and Sector Type Steering Gear.

What are the main components of steering system?

1. Steering Wheel

2. Steering column or shaft

3. Steering Gear

4. Drop Arm or Pitman Arm

5. Drag Link

6. Steering Arm

7. Track-Arms

8. Track Rod or Tie-Rod

9. Adjusting Screws

Functions of Steering System?

1. It helps in swinging the wheels to the left or right.

2. It helps in turning the vehicle at the will of the driver.

3. It provides directional stability.

4. It is used to minimize the tyre wear and tear.

5. It helps in achieving self-centering efforts.

6. It absorbs major part of the road shocks.

REQUIREMENTS OF BODIES FOR VARIOUS TYPES OF VEHICLE?

The body of the most vehicle should fulfill the following requirements:

1. The body should be light.

2. It should have minimum number of components.

3. It should provide sufficient space for passengers and luggage.

4. It should withstand vibrations while in motion.

5. It should offer minimum resistance to air.

6. It should be cheap and easy in manufacturing.

7. It should be attractive in shape and colour.

8. It should have uniformly distributed load.

9. It should have long fatigue life.

10.It should provide good vision and ventilation.

Different type of vehicle?

what are the loads acting on frame in automobile?

Various loads acting on the frame are,


1. Short duration Load - While crossing a broken patch.

2. Momentary duration Load - While taking a curve.

3. Impact Loads - Due to the collision of the vehicle.

4. Inertia Load - While applying brakes.

5. Static Loads - Loads due to chassis parts.

6. Over Loads - Beyond Design capacity.


TYPES OF CHASSIS FRAMES?

FUNCTIONS OF THE CHASSIS FRAME?

1. To carry load of the passengers or goods carried in the body.

2. To support the load of the body, engine, gear box etc.,

3. To withstand the forces caused due to the sudden braking or acceleration

4. To withstand the stresses caused due to the bad road condition.

5. To withstand centrifugal force while cornering

Main components of the Chassis?

1. Frame: it is made up of long two members called side members riveted together with the help of number of cross members.

2. Engine or Power plant: It provides the source of power.

3. Clutch: It connects and disconnects the power from the engine fly wheel to the transmission system.

4. Gear Box

6. Propeller Shaft

7. Differential 

Sunday, 22 November 2015

What is mean by Suspension System in automobile?



                      Suspension system of an automobile separates the wheel and axle assembly of the automobile from its body. Main function of the suspension system is to isolate the body of the vehicle from shocks and vibrations generated due to irregularities on the surface of roads. Shock absorbers are provided in the vehicles for this purpose. It is in the form of spring and damper. The suspension system is provided both on front end and rear end of the vehicle. A suspension system also maintains the stability of the vehicle in pitching or rolling when vehicle is in motion.

What is Steering System in automobile?


                            In front wheels can be turned to left and right by steering system so that the vehicle can be steered. The steering wheel is placed in front of driver. It is mechanically linked to the wheels to provide the steering control. The primary function of the steering system is to provide angular motion to front wheels so that vehicle can negotiate a turn. It also provides directional stability to vehicle when the vehicle moves ahead in straight line. Now-a-days, many vehicles are equipped with power steering which uses pressure of a fluid to reduce steering effort. When driver turns the steering wheel, a hydraulic mechanism comes into play to provide most of the effort needed to turn the wheel.

What is Braking System in automobile?


                         Brakes are used to slow down or stop the vehicle. Hydraulic brakes are generally used in automobiles, where brakes are applied by pressure on a fluid. Mechanical brakes are also used in some vehicles. These brakes are operated by means of 9 Introduction to Automobile Engineering leavers, linkages, pedals, cams, etc. Hand brake or parking brake is usually a mechanical brake. These are used for parking the vehicles on sloppy surfaces and also in case of emergency.

What is meant by Final Drive or Differential?


                         Final drive is the last stage in transferring power from engine to wheels. It reduces the speed of the propeller shaft (drive shaft) to that of wheels. It also turns the drive of the propeller shaft by an angle of 90o to drive the wheels.The crown wheel gives rotary motion to rear axles. The size of crown wheel in bigger than that of bevel pinion, therefore, the speed of rear axles (or crown wheel) in lower than the speed of pinion. Final drive is of two types, i.e. chain type and gear type.

What is clutch in automobile?


                    The purpose of the clutch is to allow the driver to couple or decouple the engine and transmission. When clutch is in engaged position, the engine power flows to the transmission through it (clutch). When gears are to be changed while vehicle is running, the clutch permits temporary decoupling of engine and wheels so that gears can be shifted. In a scooter, the clutch is operated by hand where as in a car the clutch is operated by foot. It is necessary to interrupt the flow of power before gears are changed. Without a clutch, it will by very difficult.

What is Transmission System (Clutch and Gear Box) in automobile?

           

             
                  The power developed by the engine is transferred to the wheels by transmission system. Transmission system must do three jobs :

(a) It must provide varying gear ratios. Number of gear ratios are equal to number of gears in a vehicle. 

(b) It must provide a reverse gear for moving vehicle in reverse direction. 

(c) It must provide a neutral or disconnecting arrangement so that the engine can be uncoupled from the wheels of the vehicle. In a conventional transmission system, there is a clutch, a manually operated transmission (gear box), a propeller shaft and a differential or final drive.

What is Chasis and Frame in automobile?


                 The chasis is formed by the frame with the frame side members and cross members. The frame is usually made of box, tubular and channel members that are welded or riveted together. In addition to this, it comprises of the springs with the axles and wheels, the steering system and the brakes, the fuel tank, the exhaust system, the radiator, the battery and other accessories. Along with this the frame supports the body.

MAIN COMPONENTS OF THE AUTOMOBILE?



1) The Engine or Power Plant : It is source of power.

2) The Frame and Chasis : It supports the engine, wheels, body, braking system, steering, etc.

3) The transmission which transmits power from the engine to the car wheels. It consists of clutch, transmission, shaft, axles and differential.

4) The body.

5) Accessories including light, air conditioner/hearer, stereo, wiper, etc. 

CLASSIFICATION OF VEHICLES BASED ON?

Engine in Front:


Most of the vehicles have engine in the front. Example : most of the cars, buses, trucks in India.

Engine in the Rear Side:



 Very few vehicles have engine located in the rear. Example : Nano car

CLASSIFICATION OF VEHICLES BASED ON TRANSMISSION?


1) Conventional vehicles with manual transmission, e.g. car with 5 gears.

2) Semi-automatic

3) Automatic : In automatic transmission, gears are not required to be changed manually. It is automatically changes as per speed of the automobile

CLASSIFICATION OF VEHICLES BASED ON BODY?


1) Sedan with two doors

2) Sedan with four doors

3) Station wagon

4) Convertible, e.g. jeep, etc.

5) Van

6) Special purpose vehicle, e.g. ambulance, milk van, etc

CLASSIFICATION OF VEHICLES BASED ON FUEL USED?


1) Petrol vehicle, e.g. motorcycle, scooter, cars, etc.

2) Diesel vehicle, e.g. trucks, buses, etc.

3) Electric vehicle which use battery to drive.

4) Steam vehicle, e.g. an engine which uses steam engine. These engines are now obsolete.

5) Gas vehicle, e.g. LPG and CNG vehicles, where LPG is liquefied petroleumgas and CNG is compressed natural gas.

CLASSIFICATION OF VEHICLES BASED ON WHEELS?


1) Two wheeler vehicle, for example : Scooter, motorcycle, scooty, etc.

2) Three wheeler vehicle, for example : Autorickshaw, three wheeler scooter for handicaps and tempo, etc.

3) Four wheeler vehicle, for example : Car, jeep, trucks, buses, etc.

4) Six wheeler vehicle, for example : Big trucks with two gear axles each having four wheels.