CPC F02B 59/00 (2013.01) [F02F 1/20 (2013.01)] | 4 Claims |
1. An internal combustion engine, comprising:
a cylinder block that includes a cylinder; and
a piston that is stored in the cylinder in a manner capable of reciprocating along an axis line of the cylinder,
wherein
the cylinder includes a multi-bulging inner circumference portion in which a diameter in a thrust-anti thrust direction is a minimal diameter, the multi-bulging inner circumference portion including multiple bulging portions that bulge outward relative to an outer diameter of a virtual cylinder having a perfect circular shape through which the piston passes;
the multi-bulging inner circumference portion is positioned below a position at which a maximal side thrust is received in the cylinder during combustion and expansion strokes; and
the bulging portions are parts having major diameters longer than the minimal diameter and gradually increase downward from the position.
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