| 摘要 |
<p>PURPOSE:To effectively prevent the excessive rise of the exhaust gas temperature by installing an intake valve opening/closing timing control means which controls an intake valve opening/closing timing changing means so that the intake valve opening timing is delayed by a prescribed time, when the exhaust gas temperature detected by an exhaust gas temperature detecting means exceeds a prescribed value. CONSTITUTION:A control unit 55 reads the exhaust gas temperature T by an exhaust gas temperature sensor 54, and when this temperature T is higher than a prescribed value, a relief valve 53 is opened. The hydraulic pressure in an oil pressure feeding passage 51 is relieved, and the interlocking between an intake valve locker arm 28 for low temperature and the first and second exhaust valve locker arms 23 and 26 for high temperature is released. At this time, the first and second intake valves 1 and 2 are opened and closed by the first and second intake valve cams 18 and 19 for high temperature through the first and second intake valve locker arms 23 and 26 for high temperature, and the opening/closing timing is controlled according to the crack angle delayed by a prescribed timing in comparison with that in the ordinary case. Therefore, the heat generation quantity can be reduced by the reduction of the charging quantity, reduction of the intake/exhaust overlap, etc.</p> |
