Introduction-automobile-engineering

AUTOMOBILE ENGINEERING (MEO-546)

Instructor: Er. Rajiv, Asst. Professor - ME, Chandigarh University

Objectives

  • Develop understanding of various automobile components and systems.

  • Impart concepts of modern automotive controls and safety features, including electronic systems and driver assistance technologies.

Definition of Automobile

An automobile is a self-propelled vehicle that produces its own power for propulsion, primarily intended for the transportation of goods and passengers on land. This distinguishes it from aeronautical and marine vehicles.

Examples:

  • Moped

  • Scooter

  • Motorcycle

  • Car

  • Jeep

  • Truck

  • Tractor

  • Ships

  • Aircraft

  • Rockets.

History of Automobiles

  • 1768-70: Captain Nicholas Joseph Cugnot constructed the first self-propelled vehicle, marking the inception of automobile engineering.

  • Cugnot Steam Trolley: Launched in 1768, this vehicle was powered by a steam engine and showcased the potential of self-propulsion.

Key Innovators

  • Karl Benz: Credited with creating the first gasoline-powered automobile in 1886, which was a pivotal moment in automotive history.

  • Benz Patent Motorwagen: Regarded as the first production car that utilized an internal combustion engine, featuring 954 cc displacement and generating 2/3 hp or 0.5 kW.

  • Flocken Elektrowagen: Introduced in 1888, this was recognized as the world's first electric car, laying foundations for alternative fuel vehicles.

  • Henry Ford: As the founder of Ford Motor Company, he revolutionized automobile production by introducing assembly line techniques, which allowed mass production of affordable motor cars, such as the Model T.

Components of an Automobile

  • Basic Structure:

    • Frame: Provides structural integrity to the vehicle.

    • Suspension System: Enhances comfort and handling by absorbing road shocks.

    • Axles: Support the weight of the vehicle and facilitate wheel rotation.

    • Wheels and Tyres: Critical for traction and performance.

  • Engine: Supplies the motive power necessary for vehicle operations, primarily utilizing internal combustion engines (IC).

  • Transmission System: Comprising the clutch, gearbox, propeller shaft, and differential gear, it facilitates the transfer of power from the engine to the wheels while optimizing speed and torque.

  • Auxiliaries:

    • Electrical Systems: These systems are essential for vehicle operation and include:

      • Supply Systems: Battery and generator to power the electrical components.

      • Starter and Ignition Systems: Enable engine start and ignition.

    • Controls: Steering systems and braking mechanisms that ensure safe vehicle operation.

  • Superstructure: This is the body of the vehicle that houses passenger and luggage spaces, as well as the engine compartment.

Engine Systems

  • Key Systems: Essential for vehicle performance and longevity include: Cooling, Fuel, Lubrication, Ignition, and Electrical Systems.

Basic Engine Terminology

  • Bore: The diameter of the cylinder.

  • Stroke: The distance traveled by the piston.

  • TDC (Top Dead Center): The highest point of piston travel.

  • BDC (Bottom Dead Center): The lowest point of piston travel.

  • Clearance Volume: Volume above the piston at TDC, critical for compression calculations.

  • Swept Volume: Volume displaced by the piston as it moves from BDC to TDC.

  • Compression Ratio: A crucial indicator of engine performance that is the ratio of total cylinder volume to the clearance volume, typically ranges between 6:1 to 10:1 for petrol engines and 15:1 to 25:1 for diesel engines.

Classification of Automobiles

  • Based on Purpose:

    • Passenger Vehicles: Includes Cars, Buses, Motorcycles.

    • Goods Vehicles: Lorry, Truck, Pickup.

  • Based on Capacity:

    • Heavy Motor Vehicles (HMV): Large trucks, Buses, and Tractors.

    • Light Motor Vehicles (LMV): Cars, Jeeps, and Motorcycles.

    • Medium Vehicles: Small trucks and Minibuses.

  • Based on Fuel Source:

    • Petrol, Diesel, Gas, Solar, Hydrogen, Electric, Steam, Hybrid Vehicles.

  • Based on Transmission Type:

    • Automatic, Conventional, and Semi-Automatic transmission vehicles.

  • By Manufacturer:

    • Notable Brands: Maruti Suzuki, Tata Motors, Mahindra, Ford, Honda, Renault.

  • By Drive Type:

    • Left-Hand Drive, Right-Hand Drive, AWD (All-Wheel Drive), 4WD (Four-Wheel Drive).

  • By Suspension Type:

    • Conventional (Leaf Spring) and Independent (Coil, Torsion bar).

  • By Engine Type:

    • Reciprocating (Piston Engines), Rotary Engines, Turbines.

  • By Body Style:

    • Sedan, Hatchback, SUV (Sport Utility Vehicle), Convertible, etc.

Functions of Transmission System

  • Connect and disconnect the engine from the road wheels to facilitate vehicle operation.

  • Manage torque and speed to optimize performance based on driving conditions.

  • Enable differential wheel speeds during turns to enhance handling and stability.

Important Components of the Transmission System

  • Clutch: Device that disconnects the engine from the wheels as needed, allowing for smooth gear shifts.

  • Gearbox: Transforms the engine's output by providing leverage variations suitable for different driving conditions.

  • Differential: Facilitates the rotation of wheels at different speeds, critical when negotiating turns.

Engine and Engine Components

  • Cylinder Block: The main structure of the engine housing the cylinders for the pistons, which contains coolant passages and oil galleries.

  • Cylinder Head: Seals the top of the cylinder, accommodating valves, spark plugs, and cooling passages for efficient operation.

  • Piston: Converts the thermal energy from combustion into mechanical power, specifically designed to withstand high pressures and temperatures.

  • Piston Rings: Ensures a proper seal within the cylinder to prevent gas and oil leakage, critical for engine efficiency.

  • Connecting Rod: Transmits the motion of the piston to the crankshaft, converting linear motion into rotary motion.

  • Crankshaft: A pivotal engine component that transforms the reciprocating motion of the pistons into rotary motion for the drivetrain.

Automobile Chassis

The chassis serves as the foundation for the vehicle, supporting major components such as the engine, suspension, and transmission systems. It is engineered for strength, stability, and safety, ensuring the vehicle's operational integrity.

Desired Qualities of a Chassis

  • Strength

  • Safety

  • Durability

  • Ease of Control

  • Quietness

  • Speed

  • Low Center of Gravity

  • Economy of Operation

Electronic Engine Management System (EEMS)

Key Functions:

  • Optimizes fuel injection control, ignition timing, idle speed control, and emissions management.

Main Components:

  • ECU (Engine Control Unit): The central computer that processes input from various sensors and makes adjustments to optimize engine performance.

  • Sensors: Include oxygen sensors, temperature sensors, and pressure sensors that provide data for efficient engine management.

  • Actuators: Responsible for physically changing engine functions based on ECU commands, enabling precise control over various systems.

Additional Notes

  • The body style and function are crucial considerations in automobile design, impacting aerodynamic efficiency, aesthetics, and user experience.

  • Key components of the cooling system include the radiator, water pump, thermostat, and cooling fans, all of which work together to prevent engine overheating and ensure optimal performance.