| 摘要 |
PURPOSE:To accurately switch compression ratio of each cylinder in good timing, by providing hydraulic cylinders, which capture a piston pin to be secured to its compression ratio position, and independently communicating supply oil paths of each cylinder group respectively with distribution oil paths in two systems. CONSTITUTION:Right and left journal parts 7, 8 are rotatably supported to right and left pin bosses 3, 4 in a piston 2. The first and the second hydraulic cylinders cy1, cy2, for arresting a piston pin P to be secured to high and low two compression ratio positions, are provided. Supply oil paths p1, p2 of the first and the second cylinder groups are respectively and independently communicated with distribution oil paths 241, 242 in two systems provided in a crankshaft 15. The distribution oil paths 241, 242 are collectively communicated to main supply oil paths 251, 252 at an end of the crankshaft 15 and to an oil pump Pu through a selector valve V. In such way, compression ratio of each cylinder can be accurately switched in good timing. |
