CONTROLLER FOR ENGINE WITH SUPERCHARGER

摘要

PURPOSE:To reduce a torque shock caused when the operation of only a main supercharger (single supercharging stage) is changed over to the operations of both main and sub-supercharger (double supercharging stage). CONSTITUTION:An exhaust bypass valve 32 and waste gate valve(WGV) 42 are provided for equalinzing the supercharging pressure of both supercharging stages to each other. A CPU controls the WGV 42 when an exhaust change-over valve 23 is opened to change over 'single' 'double' so that the supercharging pressure is reduced a fixed amount lower than intake pipe pressure PMBO right before the opening of the exhaust change-over valve 23 and gradually reqained. That is, while the CPU stores the intake pipe pressure PMBO right before the change-over of stage by an intake pressure sensor 62, the CPU obtains a drop rate B of supercharging pressure on the basis of a map specifying the drop rate B of the supercharging pressure for a passage time after the change-over of stage. Desired supercharging pressure PMW is figured out by multplaying the intake pipe pressure PMBO by drop rate B of supercharging pressure to adjust the opening of the WGV 42 so that then intake pipe pressure PM is PMW.