Page 254 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

The distributor camp is mounted on top of the distributor housing with the help of a cap holder. The cap remains
fixed on the housing as the locating knob on the underside of the cap sits in the groove of the housing. The top
surface of the distributor cap has sockets or lumps, one in the middle and one on each side for the number of
spark plugs on the engine. H fitted in the center socket of the ignition coil. T. The other end of the wire fits into the
center socket of the distributor cap. While the H installed in the side socket of the cap. T. The wires are attached
to the spark plug terminals with clips. The socket on the distributor cap is fitted with a fiber or rubber cap to
prevent dust, water or other dirt from entering. On the inner surface of the distributor cap, a round carbon brush
is mounted with the help of a spring in the central groove below the center socket. Also brass or aluminum nails
are fitted below the side socket of the cap. These nails are called segments. A brass strip on the top surface of
the rotor connects the carbon brush to the segment.
To start the engine when the engine is cranked by the starter motor, the drive gear on the distributor shaft is
rotated from the gear on the cam shaft. C in the distributor. B. Primary when the point is in the erased state
Components of Distributor
1 Distributor cap
A distributor cap is a component in the ignition system of an engine. Its main function is to distribute the high-
voltage electricity from the ignition coil to the spark plugs in the correct firing order. The distributor cap contains
a rotor that spins inside it, passing by the contacts for each spark plug wire. As the rotor passes each contact, it
sends a high-voltage pulse to the corresponding spark plug, igniting the fuel-air mixture in the engine’s cylinders.
2 C.B. point
C.B. points refer to the concept of a limited amount of carbon dioxide (CO2) emissions that can be released into
the atmosphere to limit global warming to a certain level, typically 1.5 or 2 degrees Celsius above pre-industrial
levels.
This concept is based on the idea that there is a finite amount of CO² that can be emitted before surpassing the
threshold where the Earth’s climate would experience dangerous and irreversible changes. Once this budget is
exhausted, further emissions would lead to exceeding the desired temperature targets.
3 Rotor
It is a part of a mechanical device, such as an electric motor, that is responsible for producing or transmitting
motion. In an electric motor.
4 Distributor shaft
It is a rotating shaft driven by the engine’s camshaft or, in older designs, by a gear on the engine’s crankshaft.
The distributor shaft’s main function is to distribute high-voltage electricity from the ignition coil to the spark plugs
in the correct firing order and at the right time.
The distributor shaft has a rotor, which rotates with the shaft. The rotor is connected to the high-voltage terminal of
the ignition coil through a central carbon brush or metal contact. As the rotor spins, it passes close to a series of
contacts inside the distributor cap, each of which is connected to a spark plug wire leading to a specific cylinder.
When the rotor aligns with a contact, high voltage is transferred from the ignition coil through the rotor and into the
spark plug wire, reaching the spark plug and igniting the air-fuel mixture in the corresponding cylinder.
5 Centrifugal advance mechanism
It is a component found in some internal combustion engines, particularly in older vehicles with mechanical ignition
systems. Its purpose is to advance the ignition timing as engine speed increases, improving engine performance.
6 Distributor body or housing
In summary, the distributor body or housing is a crucial part of the ignition system in old vehicle with traditional
distributor-based ignition systems. It houses the distributor shaft, distributor cap, and rotor, which work together
to ensure that the engine’s spark plugs fire at the right time.
7 C.B. Point mounting plate or breaker plate
A breaker plate, is a component used in electrical panels or distribution boards to mount circuit breakers. It
serves as a mounting platform for the circuit breakers, providing a stable and secure location for installation.
The mounting plate typically has slots to utilize different types of circuit breakers, allowing for flexibility in the
configuration of the electrical panel. The breaker plate is essential for ensuring that circuit breakers are properly
installed and secured, maintaining the functionality of the electrical system.

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CITS : Automotive - Mechanic Diesel - Lesson 76 - 79