An Introduction to Automobile

An Introduction to Automobile

1. AIM

   • Make a brief introduction on each one of the systems and general vehicle information in regard to maintenance and manufacturing design

2. Steps in Automobile History

   • innovations and Inventions
     • Steam engine used till late 1940's
       • Always tried to find new ways for the realization of the combustion and the best use of the mechanical energy within the engine without a lot of wear and tear of those fuels either steam or oil with all its derivatives
   • Mass Production
     • Hand-built cars to interchangeable parts
     • Cars were developed from horse carriages
     • Concept from rifle manufacture of civil war
     • Model T first car with design for manufacture
     • Toyota's contribution was Flexible Production
   • Development of World Motor Industry
     • Windscreen was invented in 1920s with increasing speed of vehicle
     • By end of Second World War only few specialized manufacturers remain Rolls Royce
     • Late 1930s onwards pressed steel plates for skin
     • Powered versions of horse carriages
     • Till '50s “open top” was preferred as inspired from horse carriages
   • Streamlining
     • Americans did not like the air streamlined design
     • Americans did not like the air-streamlined design
     • Aerodynamics was considered impediment to styles due to angles
   • Commercial Vehicles
     • Threats of world wars led to increase in roads, commercial vehicle sales and haulage in Europe
     • Buses replaced electric trams, challenged railways in USA, Britain
     • IC engine led to the development of motor bus
     • Autobahns in 1930s Germany led to development of good road transport along with railways
     • End of 19 th century first lorry and trucks were steam powered – challenged by petrol vehicles

3. Construction Configuration and styling

   • Engine Development
     • Diamler and Benz invented IC engine automóviles in 1895
     • Improvements in materials led to other developments
     • Diesel Engine
       • Main competitor to petrol engine spontaneous combustion unlike petrol ignition
       • It eliminated two weak points carburettor and spark plugs hence more reliable
       • With turbo-charging and refinement performance de refinement performance charging and at par with petrol engines with cleaner emissions and higher efficiency
     • Super charging and Turbocharging
       • When air is compressed at inlet, power to weight ratio of engine improve
       • Compression with power from exhaust using turbine is turbochargin
     • Two Strokes and Unconventional petrol engines
       • Two stroke diesel is still preferred in large marine and railway engines
       • Gas turbines had good efficiency and thrust to weight ratio but not efficient in low speeds
     • Electric and Hybrid Propulsion
       • Initial cars restricted to Initial cars restricted to short distances but has considerably increased in recent times
       • 1899 first vehicle cross 100kmph
       • Limitations in battery led hybrid vehicles of present day
         • Ultracapacitors or flywheel used
         • Small petrol engine used
         • Regenarative Breaking
       • Different from petrol-electric by pure electric operation
   • Transmission and System Layout
     • Some of the drawbacks of petrol engines over steam engines were
       • Non-availability of full power at the start
       • Noisy operation
     • Clutches have evolved from belts and settled pre from belts and settled pre dominantly with plate clutch.
     • F W. Lanchester and British Daimler created epicyclic gear box with bands and planetary rings
     • Ferdinan Porshe had first patent in 1908 for a electric transmission system (890299) first step towards CVT
     • Semi-stepless was achieved using fluid-torque converters in 1940's
     • Earlier cars borrowed axles similar to horse carriages with unstable pivoting axles as horse is not present to stabilize the vehicle
   • Steering
     • Ackerman's arrangement of pivoting wheels about individual axes allowed rotation at varied angles /speed during turn
     • Tiller was replaced with steering and linkages and major development came after power steering.
   • Suspension
     • Elliptic springs adopted from carts problems during braking and starting -need to be restricted
     • Springing developed by torsion bars and further by pneumatic variable height suspensions
     • Tires
       • Wooden spoked wheel with metal outer was unsuitable for higher speed
       • 1895 Michelin brothers 1895, Michelin brother fitted Dunlop tires on peugeot cars for racing and it started
       • Pneumatic tires had problems of puncture
       • Tubeless tires Tubeless tires were intro were introduced after WWII
       • Radial ply was introduced
       • “Low profile” tires – ratio of outer to inner diameter increased
       • Tubeless Tires
         • An air-tight layer to inner layer of carcass
         • Soft inner layer of highly viscous material to fill in punctures
       • Radial Tires
         • Since there is no cross ply, lesser heat generated hence more life
         • Stiffer in resisting lateral loading hence reduces under/over steer
       • Low profile tires
         • Wider tires for same diameter
         • Improvement of radial tires
         • Increased traction by more area in contact
   • Brakes
     • Horse carriages were essenty stopped by horses
     • Drum brakes with pair of internal shoes emerged as dominant
     • Until 1920s brakes only in rear wheels
     • With drum brake problem of fading due to overheat, emerged disc brakes in 1952
     • Brakes operated by mechanical rods and cables required skilled adjustment or cars would “swing”
     • 1930s hydraulic power assisted brakes introduced
     • 1960s, Dual hydraulic Dual hydraulic circuit introduced to overcome leaks
     • Heavy vehicles required servo arrangement Vacuum assist breaking
     • Anti Lock Braking introduced from aircrafts. British Jensen FF,1960 was first passenger car to have it
     • Dual hydraulic braking
       • Dual master cylinder
       • Both actuating different circuits
       • Failure of one is not affecting another
       • At least one circuit operational
   • Interior Design
     • Modern family cars not superior to high performance cars of 1930s
     • Essential dynamic analysis and design to improve quieteness
       • Direct belt between engine and cooling fan replaced by intermediate electrical
       • Vibration isolation
       • Mathematical analysis of the design
     • Air conditioning, power windows, Windows demisting added
   • Safety
     • Invention of motor cars produced more deaths than any other invention
     • 1930s “unitary” Chevrolet airflow body construction was more resistant to impact with another car
     • No significant work till 1950s and 60s as it was not a selling point
     • Pre-war cars had steering columns like spears to the heart of drivers in case of frontal impact
     • Seat belts appeared around 1950s for front seat occupants and slowly spread to rear
     • Collapsible steering introduced by 1960s'
     • Airbags came later
     • Vehicle is now designed with energy absorbers in front, rear and sides
   • Too much Innovation
     • Innovation not always a key to financial sucess
       • Wankel Engine
     • Important to choose winners at right time
       • Disc brakes
       • Power Steering