The cleaning of engine cylinder which in turn maintain the quality of combustion and decreases wear and tear inside the cylinder.A high compression ratio required to combust the fuel especially in case of diesel engine by overlapping the closing of the valve. Ideal timing for the opening and closing of the inlet and outlet valve which in turn protect the engine from defects like knocking or detonation.Provide the exit for the combustion residual so that the next cycle of the engine can take place.Provide engine with a mixed air and fuel or air in case of diesel engine when required ( at the time of suction) which is the necessity of the engine.Complete seizure of the combustion chamber at the instant at which the combustion of air-fuel mixture takes place as the leakage can cause damage to the engine and can be hazardous.Synchronisation between the steps of a cycle of the engine from intake of air-fuel ratio to the exhaust of combustion residual.The normal engine completes around 100000 cycles per minute, as we know there are number of processes involve in a single cycle (from the intake of the air-fuel mixture to the exhaust of the combustion residual) of a internal which makes it necessary to be equipped with an effective system that can enable The correct timings are of fundamental importance for the efficient and successful running of the I.C. The timing of these events, referred in terms of crank angles from dead center positions, is represented on a valve timing diagram. The ignition is also timed to occur in advance of the completion of compression stroke. The opening occurs earlier and the exhaust continues even at later crank angles. However, in actual operation, the valves do not operate at dead center positions but operate some degree on either side of the dead centers. Theoretically it may be assumed that the valves open and close and the spark occurs at the engine dead centers. The position of the piston at the top of the cylinder is called “Top Dead Centre”. The extreme position of the bottom of the cylinder is called “Bottom Dead Centre”. A valve timing diagram is a representation of the positions of the crank when the various operations as inlet valve opening, closing, exhaust valve opening and closing and also the beginning and end of various strokes.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |