POWER TRAIN SYSTEM

To suppress the intrusion of oxygen into a catalyst at a start of an engine under a condition that a temperature of an exhaust emission purification catalyst is high.SOLUTION: A power train system comprises a port injection type internal combustion engine. Processing for confining fuel in a compression stroke cylinder at a stop of the engine, and performing ignition at a first cycle of the compression stroke cylinder at the start on the basis of a stored crank stop position is called as first start processing. Processing for performing fuel injection for, for example, an intake stroke cylinder during a stop of the engine on the basis of the stored crank stop position, and performing ignition at a first cycle of the intake stroke cylinder at the start is called as second start processing. When a catalyst temperature when an engine start requirement is issued is equal to a first threshold or higher, a control device starts the internal combustion engine accompanied by at least either of the first start processing and the second start processing, and when the catalyst temperature is lower than the first threshold, the control device starts the internal combustion engine without being accompanied by any of the first start processing and the second start processing.SELECTED DRAWING: Figure 10 【課題】排気浄化触媒の温度が高い条件下でのエンジン始動時に触媒への酸素流入を抑制可能とする。【解決手段】パワートレーンシステムはポート噴射式の内燃機関を備える。エンジン停止時に圧縮行程気筒に燃料を閉じ込めておき、記憶されたクランク停止位置に基づいて始動時の圧縮行程気筒の最初のサイクルにおいて点火を実行する処理を第１始動処理と称する。記憶されたクランク停止位置に基づき、例えばエンジン停止中に吸気行程気筒のために燃料噴射を実行し、記憶されたクランク停止位置に基づいて始動時の吸気行程気筒の最初のサイクルにおいて点火を実行する処理を第２始動処理と称する。制御装置は、エンジン始動要求が出された時の触媒温度が第１閾値以上の場合には第１始動処理及び第２始動処理の少なくとも一方を伴って内燃機関を始動させ、当該触媒温度が第１閾値未満の場合には第１始動処理及び第２始動処理の何れも伴わずに内燃機関を始動させる。【選択図】図１０