To provide a piston capable of suppressing the generation of hammering sound and reducing an oil consumption.
The piston 1 receives a combustion pressure and slides in the cylinder of an internal combustion engine. The piston 1 is provided with a shape memory alloy 50 serving as a regulation part to regulate the center of gravity position of the piston 1 according to the temperature of the piston 1. The shape memory alloy 50 regulates the position of the center of gravity such that the center of gravity of the piston 1 is positioned on the anti-thrust side at the time of a low temperature, and the center of gravity is regulated such that the center of gravity of the piston 1 is positioned on a central line 19 at the time of a high temperature.
Toshio Morita
Takao Matsuyama
Tadashi Muto