1.
controller
2.
electromagnetic valve EPHH
3. screw
sensor
4. coolant
temperature sensor
5, 6.
inductive reference and angular pulse sensors
7.
ignition coils
8. spark
plugs
9.
ignition switch
10.
battery
11. fuse
and relay block
In the electronic ignition system, which is
one of the most important components of a modern car, high voltage current is
created and distributed thanks to electronic devices. The electronic system has
many clear advantages and also makes it easier to start the engine in winter.
An electronic ignition system is a system in
which high voltage current is generated and distributed by electronic devices.
The electronic ignition system of modern cars, which controls the injection and
ignition systems, is an important component of the engine management system. On
cars of the latest models, the same system is responsible for the operation of
the intake and exhaust systems, as well as the operation of the cooling system.
Today, the market offers such ignition systems
as Bosch, Simos, Motronic, Magneti-Marelli, each of which is structurally
different from the others. In general, we can say that electronic ignition
systems are divided into direct ignition systems and distributor systems. The
latter operate from a mechanical distributor , which supplies high voltage
current to a specific spark plug. If we are talking about direct ignition
systems, then the current is supplied to them directly from the ignition coil.
Electronic ignition system device
Any electronic ignition
system includes components such as a power supply, input sensors and ignition switch , electronic control
unit, igniter, coil and spark plugs . Some systems also
have high voltage wires .
Input sensors are
responsible for recording the current engine operating parameters, converting
them into electrical signals. The range of sensors may vary slightly depending
on the car model.
The electronic control
unit processes the signals coming from the input sensors, influencing, in turn,
the igniter. The igniter, which is based on a transistor, is a kind of
electronic board that turns the ignition on/off. When the transistor is open,
current flows through the primary winding of the coil. If the transistor is
closed, it is cut off, and the current is induced through the secondary winding
of the coil.
The electronic ignition
system can have different coils: one common, individual or dual. Common coils
are used in systems that have a distributor. Individual coils are installed directly
on the spark plug, so high-voltage wires are not used in such a system.
Twin coils are used in
direct ignition systems. If the engine has four cylinders, one coil is
installed on the 1st and 4th, as well as on the 2nd and 3rd cylinders, each of
which is responsible for creating current at two terminals, which is why
ignition sparks appear simultaneously in two cylinders In one, the fuel-air
mixture ignites, in the other, ignition occurs idle.
Principle of operation
The electronic control
unit responds to sensor signals, calculating the optimal parameters for the
operation of the system. First of all, the control unit acts on the igniter,
which supplies voltage to the ignition coil , in the primary winding of which
current begins to flow.
When the voltage is
interrupted, a current is induced in the secondary winding of the coil.
Directly from the coil or through high-voltage wires, the current is sent to a
specific spark plug, in which a spark is formed that ignites the fuel-air
mixture.
If the speed of rotation
of the crankshaft changes, the sensor responsible for its rotation frequency,
as well as the sensor that regulates the position of the camshaft, send signals
directly to the electronic control unit, which changes the ignition timing.
If the engine load
increases, the ignition timing is controlled by an air flow sensor . The knock sensor provides important
additional information about the ignition and combustion of the fuel-air
mixture.
Advantages of electronic ignition systems
Electronic ignition systems have many advantages:
- possibility of use on any type of carburetor engines.
- increase in secondary voltage by 1.3-1.5 times, which can be 20-30 kV in any engine operating mode.
- long service life of the breaker contacts, which can reach 150 thousand km or more.
- an increased gap is observed between the electrodes of the spark plugs , reaching 1-1.2 mm.
- in winter, the engine starts easier.
- saving time when carrying out preventive and adjustment work.
Among the
disadvantages of electronic ignition systems, the complexity and high cost of
the system primarily stand out, but all the disadvantages are compensated by
the above advantages.