Air supply and exhaust control systems for internal combustion engines.

摘要

An air supply and exhaust control system for an internal combustion engine (B9) comprises at least first and second turbosuperchargers (B6, B7), an operation prohibiting portion for prohibiting the second turbosupercharger (B7) from working as occasion demands, an exhaust gas flow detecting portion (B1), an air supply control portion (B2) for causing the operation prohibiting portion to prohibit the second turbosupercharger (B7) from working when a detection output from the exhaust gas flow detecting portion (B1) indicates that the exhaust gas flow is less than a first predetermined value, an exhaust gas discharging device (B8) connected to an exhaust passage in possession of variable exhaust resistacne for discharging the exhaust gas, an exhaust resistance changing portion for changing the variable exhaust resistance, and an exhaust control portion (B3) for controlling the exhaust resistance changing portion to set the variable exhaust resistance to be relatively small when the detection output from the exhaust gas flow detecting portion (B1) indicates that the exhaust gas flow is more than a second predetermined value which is smaller than the first predetermined value and to be relatively large when the detection output from the exhaust gas flow detecting portion (B1) indicates that the exhaust gas flow is equal to or less than the second predetermined value.