The Americana; a universal reference library, comprising the arts and sciences, literature, history, biography, geography, commerce, etc., of the world . ubstance of an engine heating at constantvolume—the explosive mixture being ignited When the crank revolves from k to /, the gasand air valves open, and the suction caused bythe outward motion of the piston fills the cylin-der with the explosive mixture. During thisoperation, the pressure of the indrawn charge isslightly diminished by expansion in a partialvacuum, so that the admission line e falls belowthe atmospheric line. Diagram B. repres
The Americana; a universal reference library, comprising the arts and sciences, literature, history, biography, geography, commerce, etc., of the world . ubstance of an engine heating at constantvolume—the explosive mixture being ignited When the crank revolves from k to /, the gasand air valves open, and the suction caused bythe outward motion of the piston fills the cylin-der with the explosive mixture. During thisoperation, the pressure of the indrawn charge isslightly diminished by expansion in a partialvacuum, so that the admission line e falls belowthe atmospheric line. Diagram B. represents the compressionstroke. When the crank continues its revolu-tion and passes from m to n, the gas and airvalves close, and the inward movement of thepiston on its first return stroke compresses thecharge into the compression space t, raising bothits temperature and pressure, the accession oftemperature being exactly sufficient to bringthe special mixture used to its point of ignitionor inflammation, as shown by the line /. 24 D220200180160MO12010080 eo 40200 InitialExpansion R j ccr — Final J7Q 5Compression P., •Admission P-— ? Final Expansion P; (Afmos;)f>er/c /./ne) -_ [ i^nitiai Compression^ Volumes in Cubic Inches Fig. 2. Indicator Diagram Four-Cycle Engine. during the slow movement of the crank over itsinner dead center so that the heat evolved bythe explosion, often as high as 3000° absolute,increases the pressure behind the piston up to250 or 300 pounds per square inch, before it canmove outward and relieve the pressure by in-creasing the volume. Cycles of Operation.—The practical work-ngcycles in use at present are the Beau de Rochasor Otto cycle, already partially defined, andmore commonly known as the four-part cycleand the two-part cycle—the former giving apower impulse for every two revolutions of thecrank, and the latter one power impulse forevery revolution of the crank Four-Cycle Engine.—The successive phasesof the four-par
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectencyclo, bookyear1908
