| 摘要 |
PURPOSE:To enhance the output power of an engine equipped with an intake pipe length control means, by providing a fluctuation factor detection means for detecting a sound speed fluctuation factor, and by performing the compensatory control of the length of an intake pipe depending on the output signal of the fluctuation factor detection means, to heighten the efficiency of inertial supercharging. CONSTITUTION:In a four-cylinder engine 1, an intake passage 3 is provided in such a manner that the upstream ends of branch intake pipes 5 connected to cylinders 2 are coupled to a common surge tank 6, and a throttle valve 8 is furnished in an intake pipe 7 at an introducing portion upstream to the surge tank. An expansible and compressible pipe 11 provided with a rack 11a is fitted movably back and forth in the intake pipe 7 to constitute an intake pipe length control means 10. The upstream end of the expansible and compressible pipe 11 is opened into an air cleaner 9. A pulse motor 12 for rotating a gear 12b engaged with the rack 11a is regulated by a control unit 13 to control the length of the intake pipe depending on the output of a rotational frequency sensor 17. The length of the intake pipe is controlled in a compensatory manner depending on the output of a sound speed fluctuation factor detection means 16 consisting of an intake air temperature sensor 14 and an atmospheric pressure sensor 15. |
