| 摘要 |
A piston (4) is designed for use in an internal combustion engine (1) provided with at least a cylinder (2) adapted to receive said piston with a possibility of bi-directional translation (A1). The piston comprises a base portion, adapted to be connected to a crankshaft (5), and a front wall (44), adapted to define a part of a combustion chamber within the cylinder of an engine. The front wall (44) is made of a metallic material and has a first predetermined configuration, when its temperature is within a first range, and a second predetermined configuration, when its temperature is within a second range. The overall shape of the front wall (44) is substantially different in these two configurations, so that the compression ratio of the engine changes according to the temperature of the front wall (44). The front wall (44) can be made of a shape memory alloy or a bi-metallic strip. |
