To provide a control device for a variable compression ratio internal combustion engine for accelerating activation of a catalyst and reducing quantity of hydrocarbon emitted to atmosphere from the engine during a period until the catalyst is activated after start of the engine or the like.
This control device is applied to the engine provided with a mechanical compression ratio change mechanism, and "an upstream catalyst 33 and a hydrocarbon adsorption device 34" disposed in the exhaust gas passage. The control device emits exhaust gas from the engine to atmosphere after making the same pass through the upstream catalyst and the hydrocarbon adsorption device if temperature of the upstream catalyst is lower than a prescribed temperature. Consequently, hydrocarbon is adsorbed by the hydrocarbon adsorption device. The control device drops mechanical compression ratio then. Accordingly, temperature of the upstream catalyst immediately rises. When temperature of the upstream catalyst reaches the prescribed temperature, the control device returns the mechanical compression ratio to a normal value with exhaust gas from the engine passing through the upstream catalyst and not passing through the hydrocarbon adsorption device.
CHIBA FUMITO
NAKASAKA YUKIHIRO
KUROKI RENTARO
