עבודה על מכוניות

Motorized vehicles
--------------------

..History

,Motorized vehicles were an old dream of mankind. But only a French
Nicole Kinio managed to implement the idea on 1769, and built a
tri-cycle with steam-operated motor, that could take two people and
.drive at a speed of 7Km/h
An Englishman, Richard Treyvitik also built on 1801 a steam-operated
carriage, and after 30 years, motorized carriages line established
between two towns in England. The distance between them was 15Km, and
the vehicle made the way in 45Minutes, which means that it's speed was
.an average of 20Km/h
The owners of train companys made many efforts to stop the developing of
the new motorized vehicle, and on 1865, the English parliament
legislated a law that prohibited the use of any motorized vehicle on the
roads without a man walking in front of it, with a red flag, or red
.light in the nights. This legislation stayed in force until 1896
In contrast to, in Europe, there where no limitation such as the one on
England. On the contrary, scientists and engineers were encouraged, and
bright engineers like Auto, Benz and few others developed
gasoline-operated engines, in explicit goal of adapting them to operate
a vehicle. The first "car"s were more like normal carriages without the
.horses in front of them, but with an engine on the back
,At the beginning of the 20th century, Cars got the shape of todays cars
but they weren't common until World War I, and the few cars that moved
belonged to rich people. After the war, many factories had time to mass
product cars, and consequently, drastically lowering the price, and a
.car was many peoples' property

..Technical

The most important parts of a car is rge engine, the transmission, thar
connects and disconnects the engine from the wheels, and the chasis
.which holds all the parts, and the body
.Most of the cars today are operated by an Auto engine, and 4 or 5 gears
.There are also "miniaturized" cars, that have tranmission with 2 gears
,Some cars are Diesel engine operated, most of them are Taxis. However
they are less common, since this motor heavier and noisier than Auto
.engine, and is mostly used on trucks and big vans
On a private car, there's an engine of 4 to 6 cylinders. Some small cars
have 2 cylinders, but not less. On the contrary, many american and
luxury cars have an engine with big volumes, and naturally, more
.cylinders
Most of the engines are water-cooled, with air-cooling system. Engine
.oil also helps cooling the engine
Every car has an electornic system. The electronic system makes the
spark that is needed to light the fire in the cylinder, thus making the
piston go up-and-down. Electronic system is also needed for the
,headlights, the horn, and many others, like washers, an air-conditioner
radio etc. Another important service that the electoronic system
provides is starting the engine, by an electronic starter, until the
.engine can go by its own
The Battery is the heart of the Electornic System, but as everything
else, it can't do all by it's own. A dynamo is installed on the car, so
the battery won't get empty. The dynamo charges the battery as long as
.the engine is on
The battery supplies electricity to the coil, that turns the low voltage
(12 volts normally, 6V on old cars) to very high voltage, about
.)!(20,000V
The coil devides the voltage to the "plug"s that makes the sparks on
.every cylinder
Some cars doesn't have this coil system, and have an electronic sparking
system, that some say that is more effecient and reliable, but some
.prefer the "older", more common way

Until the '20's, there were no electric starters, and you had to start
it manually, with a shaft. Some say that this was the reason that not
.many women drove the old cars

..The Transmission

The purpose of the transmission is the connect the engine and the
wheels. (Most cars are 2x4, which means that only 2 wheels are operated
)by the engine
The basic parts of the transmission are the Clutch, the Gearbox and the
.Diffrential
The Clutch is located between the fly-wheel, (that is next to the
engine's Crank) and the gearbox, and is needed to start driving from
.park position to driving position
The Gearbox is a set of shafts and cogwheels of many sizes, that can be
linked together in few combinations. Two shafts are connected to the
Gearbox. One is connected to the clutch, and the other is connected to
the driving shaft and the wheels. The purpose of the gearbox is to
change the rotation ratio of the two shafts. The Gearbox "offers" a
...reverse gear, which naturally, drives the car back
There is a manual Gearbox, that the driver must shift as required by the
driving needs, and an automatic Gearbox, which shifts gears by a special
.electronic/mechanical system
.The gas pedal is in the right of the clutch pedal, and is smaller
Pushing this pedal delivers more benzine to the engine, thus increasing
.the speed
The steering wheel is connected to a pole, and a system of few poles and
joints, that "translates" the movment of the steering wheel to the
.movement of the front wheels
.The Brakes are either used to slow down the car, or completely stop it
.There is also an handbrake to stop the car while parking
,On old cars, the brake system was operated by many poles and wires
which made it unreliable. Today's braking system is hydraulic, which is
.more reliable

...That's it