| 摘要 |
<p>A compression ratio changing device for an internal combustion engine using an eccentric bearing (24) interposed between a piston-pin (21) and a connecting rod (20). A lock hole (27) is formed in the eccentric bearing and a lock-pin hole (25) is formed in the connecting rod. A lock-pin (26) is slidably inserted in the lock-pin hole and can move into or out of the lock hole. When the lock-pin engages lock hole, the rotation of the eccentric bearing is locked. When the lock-pin moves apart from the lock hole, the rotation of the eccentric bearing becomes free. To obtain a smooth entry of the lock-pin into the lock hole, a guide groove (28) is formed in the outer portion of the eccentric bearing. A portion of the surface of the lock hole forms a colliding surface (33) for colliding with the lock-pin. A deformation absorbing groove (32, 34, 35, 36, 37, 38, 39, 40, 41 or 42) is formed at the outer portion of the colliding surface. The deformation absorbing groove absorbs a deformation of the eccentric bearing which may occur when the lock-pin is insufficiently driven toward the lock hole and the load of collision is large. Such a deformation absorbing groove increases the reliability of the operation of the compression ratio changing device. </p> |
