Automotive%20Systems

1
Chapter 3

• Automotive Systems

2
Automotive History

• Early vehicles were powered by electricity or
  steam.
• Most bodies were open carriage designs.
• Few major changes from the 1930s until the 1960s.
• Improved safety and pollution controls in the
  1960s.

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1970s

• OPEC oil embargo created fuel shortages and the
  demand for smaller, more efficient vehicles.
• The Corporate Average Fuel Economy (CAFE)
  standard set in 1975 .
• Leaded fuel phased out.
• Catalytic converters introduced.

4
1980s

• Mechanical systems replaced by electronic
  components.
• First use of electronic engine controls.
• Anti-Lock brakes introduced.
• Passive restraint systems and air bags installed.
• Fuel injection replacing carburetion.

5
1990s

• Fuel injection standard on all engines.
• Increasing use of electronics and computers.
• Passive restraints and ABS standard equipment on
  new cars.
• First hybrid vehicles appear.

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2000s

• Electronics and computer systems manage most
  on-board vehicle functions.
• GPS, navigation, adaptive cruise control, and
  dynamic vehicle control systems standard
  equipment.
• Hybrids available from several manufacturers.

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Typical Body Over Frame
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A Unibody Design
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The Basic Engine

• Diesel engines most common in heavy duty
  applications.
• Uses compression pressure for ignition.
• Newer diesels much cleaner and quieter.

• Gasoline engines most common in passenger cars.
• Uses a spark ignition system.
• Combined with electric motors in hybrid vehicles.

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Cylinder Block

• Made from cast iron or aluminum.
• Contains the crankshaft, pistons, and connecting
  rods.
• Forms the lower half of the engine.

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Cylinder Head

• Mounts on top of engine block.
• Made of cast iron or aluminum.
• Contains camshaft and valves.
• Has intake and exhaust manifolds attached.

12
Engine Systems

• Lubrication system
• Cooling system
• Fuel and air system
• Emission control system
• Exhaust system

• Ignition system
• Starting and charging system
• Electronic engine control system
• On-board diagnostics

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Lubrication System

• Supplies clean oil to various parts of the
  engine.
• Removes heat from combustion.
• Removes combustion by-products.
• Filters oil.

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Cooling System

• Removes heat from combustion.
• Maintains proper engine operating temperature.
• Supplies heat for passenger compartment.

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Fuel and Air Systems

• Fuel system stores and supplies fuel to the
  engine.
• Contains fuel tank, pump, and filter.
• Fuel is injected into engine by fuel injectors.

• Air intake system supplies filtered air to the
  engine .
• Air is drawn into the cylinder and mixed with
  fuel for combustion.

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Ignition System

• Must ignite the air/fuel mixture a precisely the
  correct time.
• Boosts battery voltage to 20,000 40,000 volts.
• Changes spark timing based on engine load, speed,
  and other factors.

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Starting and Charging Systems

• Electric motor converts stored energy into
  motion.
• Generator converts movement into electrical
  energy.
• Starter motors and generators can be conventional
  12v or part of hybrid motor/generator assembly.

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Heating System

• Uses coolant heated by the engine to warm the
  passenger compartment.
• Thermostat maintains minimum system temperature.

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Air Conditioning

• The A/C system removes heat and moisture from the
  passenger compartment.
• The A/C compressor can be belt driven or electric
  on a hybrid vehicle.

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Hybrid Electric Vehicles (HEVs)

• HEVs use one or more electric motors and an
  internal combustion engine (ICE) to propel the
  vehicle.
• HEVs recapture braking energy to recharge the
  high-voltage batteries.
• The high-voltage batteries pose a significant
  safety hazard if proper precautions are not
  followed.