INTERNAL COMBUSTION ENGINE CONTROL DEVICE

• Main Author: HIRAOKA SHINICHI
• Format: Patent
• Language: English; Japanese
• Published: 27.04.2015
• Subjects: BLASTING; COMBUSTION ENGINES; COMBUSTION ENGINES IN GENERAL; CONTROLLING COMBUSTION ENGINES; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; INTERNAL-COMBUSTION PISTON ENGINES; LIGHTING; MECHANICAL ENGINEERING; SUPPLYING COMBUSTION ENGINES IN GENERAL, WITH COMBUSTIBLEMIXTURES OR CONSTITUENTS THEREOF; WEAPONS

PROBLEM TO BE SOLVED: To enable suppressing a reduction in a fuel economy improvement effect due to shortage of an external EGR introduction quantity during acceleration in an engine with a supercharger and with an EGR system.SOLUTION: An internal combustion engine control device calculates an external EGR introduction quantity (flow of an EGR gas introduced into an engine 11), and calculates a deviation between a target EGR quantity and the external EGR quantity as a shortage of the external EGR introduction quantity. If this shortage of the external EGR introduction quantity exceeds a predetermined value, the internal combustion engine control device executes a WGV opening control to control a WGV (wastegate valve) 27 to be opened. As a result, if the target EGR quantity increases at a time of accelerating the engine 11 and a delay in response of the external EGR introduction quantity to the target EGR quantity causes the shortage of the external EGR introduction quantity, the internal combustion engine control device executes the WGV opening control to control the WGV 27 to be opened so as to reduce an exhaust pressure upstream of an exhaust turbine 18. The reduction in the exhaust pressure can lead to a reduction in pump loss of the engine 11 and a reduction in an internal EGR quantity to decrease an internal temperature of each cylinder. 【課題】ＥＧＲ装置を備えた過給機付きエンジンにおいて、加速時の外部ＥＧＲ導入量の不足による燃費改善効果の低減を抑制できるようにする。【解決手段】外部ＥＧＲ導入量（エンジン１１に導入されるＥＧＲガス流量）を算出し、目標ＥＧＲ量と外部ＥＧＲ導入量との偏差を外部ＥＧＲ導入不足量として算出する。この外部ＥＧＲ導入不足量が所定値を越えたときに、ＷＧＶ（ウェイストゲートバルブ）２７を開き側に制御するＷＧＶ開制御を実行する。これにより、エンジン１１の加速時に目標ＥＧＲ量が増加して、目標ＥＧＲ量に対する外部ＥＧＲ導入量の応答遅れによって外部ＥＧＲ導入量に不足が生じたときに、ＷＧＶ２７を開き側に制御するＷＧＶ開制御を実行して排気タービン１８上流の排気圧を低減する。この排気圧の低減によりエンジン１１のポンプ損失を低減すると共に内部ＥＧＲ量を低減して筒内温度を低下させる。【選択図】図１