| 摘要 |
<p>PURPOSE:To improve the fuel expense efficiency while preventing the generation of knocking by converting the compression ratio of the combustion chamber from a high compression ratio to a low compression ratio when it becomes a high load, at least in the high rotation area of the engine, when a low supercharging pressure is set. CONSTITUTION:In a piston 44 installed in a cylinder 42, the upper end 58a of a connecting rod 58 is connected to a piston pin 56 in which a projection 56a to compose a compression ratio converting device 60 is formed at the middle part, and the volume of the combustion chamber 12 (the compression ratio) is different when the projection 56a is positioned at the upper side and when it is positioned at the lower side, And, by gearing a lock pin 59 to the gearing hole 56b of the piston pin 56 or to the gearing hole 56c, the position of the projection 56a is converted. In this case, when a turbo-supercharger 18 is set at a low supercharging pressure, the compression ratio is controlled to convert from a high ratio to a low ratio when the load becomes a high load, at least in a high rotation area, compared to the case when the supercharger 18 is set at a high supercharging pressure.</p> |
