PURPOSE: To reduce rate of fuel consumption by providing a bypass valve in a bypass line formed to bypass a mechanical supercharger in an intake line and controlling the valve so that negative pressure in an intake line between a throttle valve and the supercharger equals to the predetermined pressure during idling operation.
CONSTITUTION: An intake duct 10 is connected to an intake port 7 and to the delivery side of a mechanical supercharger 12 driven by an engine through an intercooler 11. An intake duct 13 is connected to the intake side of the supercharger 12 and to an air cleaner 15 through an air flow meter 14. Throttle valve 16 is located in the intake duct 13, and also a bypass valve 20 is located in the bypass line 19 provided to bypass the supercharger 12. These valves 16, 20 are controlled by an electronic control unit 30. The bypass valve 20 is so controlled that the detected negative pressure equals to the predetermined negative pressure according to the output of a pressure (negative) sensor 27 in the intake duct 13 located between the throttle valve and the supercharger 12.
NOGUCHI HIROSHI
HIROSE KATSUHIKO
KATO YOSHIRO
KAWAGOE MICHIO
NAKAMURA NORIHIKO
| JP63130631B |