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The piston, while reciprocating inside the cylinder, can occupy two extreme positions. The uppermost position of the piston is termed the top dead center (TDC), while the lowermost position is referred to as the bottom dead center (BDC). The total volume between the cylinder head and the piston face when the piston is at the bottom dead center is called the air volume. The volume at the top dead center (TDC) is that volume occupied when the piston is closest to the cylinder head; the space between the piston face and cylinder head at TDC is called the clearance or the volume of the combustion chamber. The distance traveled by the piston between its TDC and BDC locations is the stroke. During one piston stroke the crankshaft rotates half a turn. The volume displaced by the piston as it moves from the bottom dead center to the top dead center is termed the displacement, also known as the swept, or stroke, volume. The displacement of all the cylinders of an engine is termed the engine displacement, or capacity. It is measured in cubic centimeters or liters. The displacement is related to the horsepower rating of an engine. Closely associated with the displacement is a characteristic known as the compression ratio. The compression ratio of a reciprocating engine is the ratio of the total (air) volume, i.e., the clearance volume plus swept volume, to the clearance. The actual compression ratio in practice is somewhat less. Higher compression ratios usually provide better engine performance, but they require a fuel with better antiknock characteristics. 1) дайте определения понятиям: ВМТ, НМТ, полный объем цилиндра, такт, рабочий объём, объем камеры сгорания, литраж двигателя, степень сжатия. 2) определите, какие показатели влияют на мощность двигателя 3) найдите информацию о том, за сколько оборотов коленчатого вала совершается один такт поршня.
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5. Сопоставьте обозначения на рисунке 1, 2, 3, 4, 5, 6 Va, Vh, Vc, ВМТ, НМТ
