INTAKE/EXHAUST SYSTEM FOR ENGINE

To provide an intake/exhaust system for an engine that largely increases filling efficiency to increase output through setting to enable an impulse valve to be appropriately opened.SOLUTION: In an intake/exhaust system for an engine 1 including an impulse valve 25 for opening/closing an intake passage upstream of an intake valve 50, a valve opening period of the impulse valve 25 is set to be shorter than a valve opening period of the intake valve 50 and within the valve opening period of the intake valve 50. Opening amount that is an integrated value of lift amount of the impulse valve 25 per one cycle of the engine 1 is set to be smaller than opening amount of an exhaust valve 66, and opening amount of the exhaust valve 66 is set to be smaller than the opening amount of the intake valve 50.SELECTED DRAWING: Figure 1 【課題】インパルスバルブを適切に開弁させるように設定して、充填効率を大きく上昇させて出力を増加させるエンジンの吸排気装置を提供する。【解決手段】吸気バルブ５０の上流側の吸気通路を開閉するインパルスバルブ２５を備えたエンジン１の吸排気装置であって、インパルスバルブ２５の開弁期間を、吸気バルブ５０の開弁期間より短く、かつ吸気バルブ５０の開弁期間内に設定するとともに、エンジン１の１サイクル当たりの、インパルスバルブ２５のリフト量の積分値である開口量を、排気バルブ６６の開口量より小さく、かつ排気バルブ６６の開口量を吸気バルブ５０の開口量より小さく設定する。【選択図】図１