Patent attributes
An engine includes an electric supercharger as a first supercharger, a turbocharger as a second supercharger, a secondary air supply passage, a secondary air valve and a catalyst. The electric supercharger is provided in an intake passage which is in communication with a combustion chamber, and supercharges intake air into the combustion chamber. The turbocharger is provided in the intake passage in series with respect to the electric supercharger, and supercharges intake air to the combustion chamber. The secondary air supply passage and the secondary air valve supply air compressed by the electric supercharger to a discharge passage which is in communication with the combustion chamber. The catalyst is provided in the discharge passage to purify exhaust gas.
