CONTROL DEVICE FOR ENGINE

PROBLEM TO BE SOLVED: To provide a control device for an engine, capable of suppressing the occurrence of knocking even in deceleration and re-acceleration during constant speed travel.SOLUTION: The control device for the engine includes a supercharger (51), a compression ratio variable mechanism capable of varying the compression ratio of the engine, revolving speed detecting means (94) for detecting the revolving speed of the engine, load detecting means for detecting the load of the engine, target compression ratio setting means (91) for setting a target compression ratio to be lower in a region on the high revolving speed side than in a region on the low revolving speed side even under the same load, on the basis of the detected engine revolving speed and the detected engine load, and compression ratio control means (91) for controlling the compression ratio of the compression ratio variable mechanism to obtain the set target compression ratio.SELECTED DRAWING: Figure 1 【課題】定速走行中の減速再加速時であっても、ノックの発生を抑制し得る装置を提供する。【解決手段】過給機（５１）と、エンジンの圧縮比を変更し得る圧縮比可変機構と、エンジンの回転速度を検出する回転速度検出手段（９４）と、エンジンの負荷を検出する負荷検出手段と、前記検出されたエンジン回転速度および前記検出されたエンジン負荷に基づき、同じ負荷でも高回転速度側の領域で目標圧縮比を低回転速度側の領域より低い側に設定する目標圧縮比設定手段（９１）と、前記設定された目標圧縮比が得られるように前記圧縮比可変機構の圧縮比を制御する圧縮比制御手段（９１）と、を備える。【選択図】図１