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 using SI combustion and SPCCI combustion in combination for maintaining both a tumble flow and a swirl flow until a late period for a compression stroke.SOLUTION: A combustion chamber of the engine has a geometric compression ratio set to be 15 or over to enable the SPCCI combustion. A crown surface 50 of a piston 5 includes a cavity 51 recessed in a bowl shape, and an F side protruded part 52F and an R side protruded part 52R protruded in an outer periphery region of the cavity 51 in a cylinder axial direction and having a mountain shape along the pent roof shape of the ceiling surface of the combustion chamber. B/L is set in a range of being greater than 1.0 and equal to or smaller than 1.52, where L is a space between both the protruded parts 52F, 52R and B is the diameter of the piston 5.SELECTED DRAWING: Figure 12 【課題】ＳＩ燃焼とＳＰＣＣＩ燃焼とを併用する同エンジンにおいて、タンブル流及びスワール流の双方を圧縮行程後期まで維持する。【解決手段】エンジンの燃焼室は、幾何学的圧縮比が１５以上に設定され、ＳＰＣＣＩ燃焼が可能とされている。ピストン５の冠面５０には、椀状に凹設されてなるキャビティ５１と、キャビティ５１の外周領域において気筒軸方向に突設され、燃焼室天井面のペントルーフ形状に沿った山型形状を有するＦ側凸部５２Ｆ及びＲ側凸部５２Ｒが備えられている。両凸部５２Ｆ、５２Ｒの間隔をＬ、ピストン５の直径をＢとするとき、Ｂ／Ｌが１．０より大きく１．５２以下の範囲に設定されている。【選択図】図１２