| 摘要 |
The present invention is provided with: a first and a second turbocharger (16A, 16B) that perform supercharging respectively for a first cylinder group and a second cylinder group, the operations of which are continued or stopped by means of a cylinder-reduction-use valve-stopping mechanism (21); and a third turbocharger (26) that supplies the air (A) from these two turbochargers (16A, 16B) to the first and second cylinder groups through separate intake passages (12A, 12B), and that performs supercharging of the two turbochargers (16A, 16B). Thus, when a reduced-cylinder operation system, which is equipped with a valve-stopping mechanism that temporarily stops the intake/exhaust valves, is provided in addition to a turbocharging system, a decrease in the supercharging amount can be prevented during reduced-cylinder operation and a sufficient amount of air can be supplied to the operating cylinders, so that deterioration of combustion in the operating cylinders and deterioration of the exhaust gas conditions, which occur easily during reduced-cylinder operation, can be prevented, and fuel efficiency can be effectively improved. |
