COMBUSTION CHAMBER STRUCTURE FOR ENGINE

• Main Authors: NISHI FUTA, HONDA YUYA, INOUE ATSUSHI, KONO MICHIHARU, IMAMURA SATOSHI, NAKAHARA KOJI, MATSUMOTO KOTA, FUKUMA MASANARI
• Format: Patent
• Language: English; Japanese
• Published: 04.06.2020
• Subjects: ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES; BLASTING; COMBUSTION ENGINES; COMBUSTION ENGINES IN GENERAL; CYLINDERS; CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; INTERNAL-COMBUSTION PISTON ENGINES; LIGHTING; MECHANICAL ENGINEERING; PISTONS; SEALINGS; THERMAL INSULATION IN GENERAL; WEAPONS

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