1 slide
2 slide
Engine internal combustion(abbreviated internal combustion engine) is a device in which the chemical energy of the fuel is converted into useful mechanical work. Internal combustion engines are classified: By purpose - they are divided into transport, stationary and special. According to the type of fuel used - light liquid (gasoline, gas), heavy liquid ( diesel fuel). By way of education combustible mixture- external (carburetor) and internal diesel internal combustion engine. According to the method of ignition (spark or compression). According to the number and arrangement of cylinders, in-line, vertical, boxer, V-shaped, VR-shaped and W-shaped engines are divided.
3 slide
Internal combustion engine elements: Cylinder Piston - moves inside the cylinder Fuel injection valve Spark plug - ignites the fuel inside the cylinder Gas release valve Crankshaft - is spun by the piston
4 slide
Operation cycles of piston internal combustion engines Reciprocating internal combustion engines are classified according to the number of strokes in the operating cycle into two-stroke and four-stroke. The working cycle in reciprocating internal combustion engines consists of five processes: intake, compression, combustion, expansion and exhaust.
5 slide
6 slide
1. In the intake process, the piston moves from top dead center (TDC) to bottom dead center (BDC), and the freed over-piston space of the cylinder is filled with a mixture of air and fuel. Due to the pressure difference in the intake manifold and inside the engine cylinder, when the intake valve is opened, the mixture enters (is sucked in) into the cylinder
7 slide
2. During the compression process, both valves are closed and the piston, moving from n.m.t. to w.m.t. and reducing the volume of the cavity above the piston, compresses the working mixture (in the general case, the working fluid). The compression of the working fluid accelerates the combustion process and thereby predetermines the possible completeness of the use of the heat released during the combustion of fuel in the cylinder.
8 slide
3. In the process of combustion, the fuel is oxidized by air oxygen, which is part of the working mixture, as a result of which the pressure in the over-piston cavity increases sharply.
9 slide
4. In the process of expansion, hot gases, seeking to expand, move the piston from the T.M.T. to n.m.t. The working stroke of the piston is made, which through the connecting rod transfers pressure to the crankpin crankshaft and turns it around.
10 slide
5. During the release process, the piston moves from n.m.t. to w.m.t. and through the second valve that opens by this time, pushes the exhaust gases out of the cylinder. The products of combustion remain only in the volume of the combustion chamber, from where they cannot be displaced by the piston. The continuity of the engine is ensured by the subsequent repetition of the work cycles.
11 slide
12 slide
The history of the car The history of the car began in 1768, along with the creation of steam-powered machines capable of transporting a person. In 1806, the first machines appeared, driven by internal combustion engines in English. combustible gas, which led to the introduction in 1885 of the gasoline or gasoline internal combustion engine commonly used today.
13 slide
Pioneer Inventors German engineer Karl Benz, the inventor of many automotive technologies, is credited with inventing the modern automobile.
14 slide
Karl Benz In 1871, together with August Ritter, he organized a mechanical workshop in Mannheim, received a patent for a two-stroke Gas engine, soon he patented the systems of the future car: an accelerator, an ignition system, a carburetor, a clutch, a gearbox and a cooling radiator.
The history of the creation of the first internal combustion engine The first truly
workable Internal Combustion Engine (ICE)
appeared in Germany in 1878. But the history of creation
ICE has its roots in France.
In 1860 the French inventor Ethven Lenoir
invented
the first internal combustion engine. But this unit
was imperfect, with low efficiency and could not be applied
on practice. Another Frenchman came to the rescue
inventor Beau de Rochas, who in 1862 proposed
use four strokes in this engine:
1.Inlet
2.Compression
3. Working stroke
4. Release stroke
The first four-stroke ICE car was
three-wheeled carriage by Karl Benz, built in 1885
year.
A year later (1886) Gottlieb Daimer's version appeared.
Both inventors worked independently of each other.
They merged in 1926 to form Deimler-Benz.
AG.
The principle of operation of the internal combustion engine
Modern car, most of all,driven by an internal motor
combustion. There are many such engines.
lots of. They differ in volume
number of cylinders, power, speed
rotation, fuel used (diesel,
gasoline and gas combustion engines). But, fundamentally,
internal combustion engine device
it seems. How does this device work and why?
called a four-stroke engine
internal combustion? About internal combustion
clear. Fuel burns inside the engine. BUT
why 4 stroke engine, what is it?
Indeed, there are two-stroke
engines. But on cars they are used
rarely. Four stroke engine
called because of the fact that his work can be
divided into four equal parts.
The piston will pass through the cylinder four times - two
up and down twice. The beat starts at
finding the piston in the extreme lower or
top point. For motorists-mechanics it is
called top dead center (TDC) and
bottom dead center (BDC).
First stroke - intake stroke
The first beat, he is the inlet,starts at TDC (top
dead point). moving down
piston sucks into cylinder
air-fuel mixture. Work
this beat occurs when
open intake valve. By the way,
there are many engines
multiple intake valves.
Their number, size, time
being in the open
can significantly affect
engine power. There is
engines in which
depending on the pressure on the pedal
gas, forced
increase in residence time
intake valves open
condition. It's made for
increasing the number
intake fuel, which
after ignition, increases
engine power. Automobile,
in this case, maybe much
accelerate faster.
The second stroke is the compression stroke
The next stroke of the engine iscompression stroke. After the piston
bottomed out, he starts
rise up, thereby squeezing
mixture that entered the cylinder on the beat
inlet. The fuel mixture is compressed to
combustion chamber volumes. What is this
such a camera? Free space
between the top of the piston and
top of the cylinder
piston at top dead
point is called the combustion chamber.
Valves, in this stroke of the engine
closed completely. The denser they
closed, the compression occurs
better. Great importance
has, in this case, the state
piston, cylinder, piston rings.
If there are large gaps, then
good compression will not work, but
accordingly, the power of such
engine will be much lower. Degree
compression - compression, you can check
special device. By size
compression, it can be concluded that
engine wear.
Third cycle - working stroke
The third measure is a working one, it starts withTDC. It's called a worker
not by chance. After all, it is in this
tact is an action,
forcing the car
move. In this tact to work
the ignition system comes on. Why
is this system called? Yes
because she is in charge
ignition fuel mixture, compressed
in the cylinder, in the combustion chamber.
It works very simply - a candle
system gives a spark. Justice
for the sake of it, it is worth noting that the spark
issued on the spark plug for
a few degrees before reaching
top piston. These
degrees, in a modern engine,
automatically adjusted
the brains of the car. After
as the fuel ignites, occurs
explosion - it increases sharply in
volume, forcing the piston
move down. Valves on this beat
engine operation, as in
previous, are in a closed
condition.
The fourth measure is the release measure
Fourth cycle of workengine, the last
high school graduation. Reaching
bottom point, after
working cycle, in the engine
starts to open
Exhaust valve. Such
valves, as well as inlet,
there may be several.
Moving up, the piston
removes through this valve
exhaust gases from
cylinder - ventilates
his. The better it works
exhaust valve,
more exhaust gases
removed from the cylinder
thereby freeing
place for a new portion
fuel-air mixture.
Varieties of the internal combustion engine
Diesel internal combustion engine
Diesel engine - pistoninternal combustion engine,
flammable
atomized fuel from
contact with compressed heated
air. Diesel engines work
on diesel fuel (colloquially -
"sunshine").
In 1890, Rudolf Diesel developed the theory
"economical thermal engine",
which, due to the strong compression in
cylinders significantly improves its
efficiency. He received a patent for his
engine February 23, 1893. First
a functioning example called the "Diesel Motor" was built by Diesel by early 1897
year, and on January 28 of the same year he was successfully
tested.
The principle of operation of the injection engine
In modern injectionengines for everyone
cylinder provided
individual nozzle.
All nozzles are connected to
fuel rail, where
fuel is under
pressure that creates
electric fuel pump.
Injected quantity
fuel depends on
opening duration
nozzles. Opening moment
regulates the electronic unit
control (controller) on
based on processed
them data from various
sensors.
creation..
History of creation
Etienne Lenoir (1822-1900)
Stages of ICE development:
1860 Étienne Lenoir invents the first light gas engine
1862 Alphonse Beau De Rochas proposed the idea of a four-stroke engine. However, he failed to implement his idea.
1876 Nikolaus August Otto creates four stroke engine by Roche.
1883 Daimler proposed an engine design that could run on both gas and gasoline
Karl Benz invented the self-propelled tricycle based on Daimler technology.
By 1920, internal combustion engines become leading. crews on steam and electric traction have become a rarity.
August Otto (1832-1891)
Karl Benz
History of creation
Tricycle, invented by Karl Benz
Operating principle
Four stroke engine
Duty cycle of a four-stroke carburetor engine internal combustion takes place in 4 strokes of the piston (stroke), i.e., in 2 revolutions of the crankshaft.
There are 4 cycles:
1 stroke - intake (the combustible mixture from the carburetor enters the cylinder)
2 stroke - compression (the valves are closed and the mixture is compressed, at the end of compression the mixture is ignited by an electric spark and fuel is burned)
3 stroke - working stroke (heat received from fuel combustion is converted into mechanical work)
4 stroke - release (exhaust gases are displaced by the piston)
Operating principle
Two stroke engine
There is also two stroke engine internal combustion. The working cycle of a two-stroke carburetor internal combustion engine is carried out in two strokes of the piston or in one revolution of the crankshaft.
1 measure 2 measure
Combustion |
|
In practice, the power of a two-stroke carburetor internal combustion engine often not only does not exceed the power of a four-stroke, but is even lower. This is due to the fact that a significant part of the stroke (20-35%) the piston makes with open valves
Engine efficiency
The efficiency of an internal combustion engine is low and is approximately 25% - 40%. The maximum effective efficiency of the most advanced internal combustion engines is about 44%. Therefore, many scientists are trying to increase the efficiency, as well as the very power of the engine.
Ways to increase engine power:
Use of multi-cylinder engines
Use of special fuel (correct mixture ratio and type of mixture)
Replacement of engine parts ( correct sizes constituent parts, depending on the type of engine)
Elimination of part of the heat loss by moving the place of fuel combustion and heating of the working fluid inside the cylinder
Engine efficiency
Compression ratio
One of the most important characteristics of an engine is its compression ratio, which is determined by the following:
eV2V1
where V2 and V1 are the volumes at the beginning and at the end of compression. With an increase in the compression ratio, the initial temperature of the combustible mixture at the end of the compression stroke increases, which contributes to its more complete combustion.
Varieties of internal combustion engines
Internal Combustion Engines
Main engine components
The structure of a bright representative of the internal combustion engine - a carburetor engine
Engine frame (crankcase, cylinder heads, crankshaft bearing caps, oil pan)
movement mechanism(pistons, connecting rods, crankshaft, flywheel)
Gas distribution mechanism(camshaft, pushrods, rods, rocker arms)
Lubrication system (oil, coarse filter, sump)
liquid (radiator, liquid, etc.)
Cooling system
air (blowing with air currents)
Power system (fuel tank, fuel filter, carburetor, pumps)
Main engine components
Ignition system(current source - generator and battery, breaker + capacitor)
Starting system (electric starter, current source - battery, remote controls)
Intake and exhaust system(pipelines, air filter, muffler)
Engine carburetor
slide 1
Physics lesson in grade 8
slide 2
Question 1:
What physical quantity shows how much energy is released when burning 1 kg of fuel? What letter is it? Specific heat of combustion of fuel. g
slide 3
Question 2:
Determine the amount of heat released during the combustion of 200 g of gasoline. g=4.6*10 7J/kg Q=9.2*10 6J
slide 4
Question 3:
The specific heat of combustion of coal is about 2 times greater than the specific heat of combustion of peat. What does it mean. This means that the combustion of coal will require 2 times more heat.
slide 5
Internal combustion engine
All bodies have internal energy - earth, bricks, clouds and so on. However, most often it is difficult to extract it, and sometimes impossible. The most easily used for human needs is the internal energy of only some, figuratively speaking, "combustible" and "hot" bodies. These include: oil, coal, warm springs near volcanoes, and so on. Consider one of the examples of using the internal energy of such bodies.
slide 6
Slide 7
Carburetor engine.
carburetor - a device for mixing gasoline with air in the right proportions.
Slide 8
Main main parts of an internal combustion engine parts of an internal combustion engine
1 - intake air filter, 2 - carburetor, 3 - gas tank, 4 - fuel line, 5 - spray gasoline, 6 - intake valve, 7 - glow plug, 8 - combustion chamber, 9 - exhaust valve, 10 - cylinder, 11 - piston.
:
The main parts of the internal combustion engine:
Slide 9
The operation of this engine consists of several stages repeating one after another, or, as they say, cycles. There are four in total. The stroke count starts from the moment when the piston is at its highest point, and both valves are closed.
Slide 10
The first stroke is called the inlet (Fig. "a"). The intake valve opens and the descending piston draws the gasoline-air mixture into the combustion chamber. The intake valve then closes.
slide 11
The second step is compression (Fig. "b"). The piston, rising up, compresses the gasoline-air mixture.
slide 12
The third stroke is the working stroke of the piston (Fig. "c"). An electric spark flashes at the end of the candle. The gasoline-air mixture burns almost instantly and there is a heat. This leads to a strong increase in pressure and the hot gas does useful work - it pushes the piston down.
slide 13
The fourth measure is the release (rice "d"). The exhaust valve opens and the piston, moving up, pushes the gases out of the combustion chamber into exhaust pipe. Then the valve closes.
Slide 14
physical education minute
slide 15
Diesel engine.
In 1892, the German engineer R. Diesel received a patent (a document confirming the invention) for an engine, later named after him.
slide 16
Principle of operation:
Only air enters the cylinders of a Diesel engine. The piston, compressing this air, does work on it and the internal energy of the air increases so much that the fuel injected there immediately ignites spontaneously. The resulting gases push the piston back, carrying out the working stroke.
Slide 17
Work cycles:
air intake; air compression; fuel injection and combustion - piston stroke; release of exhaust gases. A significant difference: the glow plug becomes unnecessary, and its place is taken by a nozzle - a device for injecting fuel; usually these are low-quality grades of gasoline.
Slide 18
Some information about engines Engine type Engine type
Some information about engines Carburetor Diesel
History of creation First patented in 1860 by the Frenchman Lenoir; in 1878 built by German. inventor Otto and engineer Langen Invented in 1893 by German engineer Diesel
Working fluid Air, sat. gasoline vapor Air
Fuel Gasoline Fuel oil, oil
Max. chamber pressure 6 × 105 Pa 1.5 × 106 - 3.5 × 106 Pa
T at compression of the working fluid 360-400 ºС 500-700 ºС
T of fuel combustion products 1800 ºС 1900 ºС
Efficiency: for serial machines for the best samples 20-25% 35% 30-38% 45%
Application In cars of relatively small power In heavier machines of high power (tractors, freight tractors, diesel locomotives).
Slide 19
Slide 20
Name the main parts of the engine:
slide 21
1. What are the main cycles of the internal combustion engine. 2. In what cycles are the valves closed? 3. In what cycles is valve 1 open? 4. In what cycles is valve 2 open? 5. What is the difference between an internal combustion engine and a diesel engine?
slide 22
Dead spots - extreme positions of the piston in the cylinder
Piston stroke - the distance traveled by the piston from one dead center to another
Four-stroke engine - one working cycle occurs in four piston strokes (4 cycles).
slide 23
Fill in the table
Bar name Piston movement 1 valve 2 valve What happens
Inlet
Compression
working stroke
release
way down
up
way down
up
open
open
closed
closed
closed
closed
closed
closed
Combustible mixture suction
Compression of the combustible mixture and ignition
The gases push the piston
Exhaust gas emission
slide 24
1. Type heat engine, in which steam rotates the engine shaft without the help of a piston, connecting rod and crankshaft. 2. Designation of specific heat of fusion. 3. One of the parts of the internal combustion engine. 4. Cycle cycle of an internal combustion engine. 5. The transition of a substance from a liquid to a solid state. 6. Vaporization occurring from the surface of the liquid.