COMBUSTION CHAMBER STRUCTURE FOR ENGINE
To provide a combustion chamber structure for an engine capable of actualizing high combustion efficiency by maintaining a swirl flow in SPCCI combustion until the late period for a compression stroke.SOLUTION: A combustion chamber of an engine body is divided by a crown surface 50 of a piston 5, th...
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Main Authors | , , , , , , , |
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Format | Patent |
Language | English Japanese |
Published |
04.06.2020
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Subjects | |
Online Access | Get full text |
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Summary: | To provide a combustion chamber structure for an engine capable of actualizing high combustion efficiency by maintaining a swirl flow in SPCCI combustion until the late period for a compression stroke.SOLUTION: A combustion chamber of an engine body is divided by a crown surface 50 of a piston 5, the inner wall face of a cylinder, and a pent-roof-shaped ceiling surface. The crown surface 50 of the piston 5 includes a cavity 51 recessed in a bowl shape. The bottom face of the cavity 51 has a bottom 511 including a deepest portion 51B of the cavity 51 and its vicinity, an F side peripheral wall 512F arranged +x side with respect to the bottom 511, and an R side peripheral wall 512R arranged on a -x side with respect to the bottom 511. Both relationship of 1.0<R/Rf≤64.0 and 1.0<R/Rr≤64.0 are satisfied where R is the curvature radius of the curved surface of the bottom 511, Rf is the curvature radius of the curved surface of the F side peripheral wall 512, and Rr is the curvature radius of the curved surface of the R side peripheral wall 512R.SELECTED DRAWING: Figure 10
【課題】SPCCI燃焼におけるスワール流を圧縮行程の後期まで維持することで、高い燃焼効率を実現することができるエンジンの燃焼室構造を提供する。【解決手段】エンジン本体の燃焼室は、ピストン5の冠面50と、気筒の内壁面と、ペントルーフ形の天井面とによって区画されている。ピストン5の冠面50は、椀状に凹設されてなるキャビティ51を備える。キャビティ51の底面は、該キャビティ51の最深部51Bとその周辺を含む底部511と、底部511に対して+X側に配置されたF側周壁512Fと、底部511に対して−X側の配置されたR側周壁512Rと、を有する。底部511の曲面の曲率半径Rと、F側周壁512Fの曲面の曲率半径Rfと、R側周壁512Rの曲面の曲率半径Rrとは、1.0<R/Rf≦64.0および1.0<R/Rr≦64.0の両関係を満たす。【選択図】図10 |
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Bibliography: | Application Number: JP20180215599 |