Title:
SPARK IGNITION TYPE INTERNAL COMBUSTION ENGINE
Document Type and Number:
Japanese Patent JP2021179175
Kind Code:
A
Abstract:
To suppress lowering of moving speed of a flame on a crown surface of a piston when a mirror-finished region is formed on the crown surface.SOLUTION: A spark ignition type internal combustion engine includes a cylinder head and a piston. A crown surface of the piston includes a central part and first and second outer parts located on the outer side of the central part. The central part and the first outer part have the combustion chamber height higher than a predetermined value. The combustion chamber height indicates a distance between the crown surface and a lower surface of the cylinder head at a compression top dead center. The combustion chamber height of the second outer part is equal to or lower than the predetermined value. The crown surface is divided into a mirror surface region and a rough surface region. The mirror surface region has less than 0.05 μm of surface roughness. The rough surface region has 0.05 μm or more and 2.5 μm or less of surface roughness. All of the central part and the first outer part are included in the mirror surface region. At least a portion of the second outer part is included in the rough surface region.SELECTED DRAWING: Figure 6
Inventors:
TAKADA TOMOYUKI
Application Number:
JP2020083314A
Publication Date:
November 18, 2021
Filing Date:
May 11, 2020
Export Citation:
Assignee:
TOYOTA MOTOR CORP
International Classes:
F02B23/08; F02F3/26; F16J1/02
Attorney, Agent or Firm:
Hideki Takahashi
Mamoru Takada
Hidekazu Onishi
Mamoru Takada
Hidekazu Onishi