| 摘要 |
PURPOSE:To improve intake efficiency by making independent intake tubes of respective cylinders to meet those tubes in which ignition timings are not adjacent to those of counterpart cylinders, providing an open-and-close valve on the meeting part in order to give mutual communication among the respective groups and further communicating intake tubes of the respective groups with the inside of intake tubes located upstream therefrom, through an open-and-close valve. CONSTITUTION:Independent intake tubes 81-84 of respective cylinders 71-74 are respectively made to meet the cylinder groups in which ignition timings are not adjacent to those of counterpart cylinders, and an open-and-close valve is mounted on a through tube 10 on the meeting part so as to give free communication. Said through part is made to have free communication to intake tubes 61, 62 of the respective groups through a through tube 9 and an open-and-close valve 11 provided on the respective tubes as well as to meet them upstream therefrom. A control unit 16 drives the respective open-and-close valves 11, 12 in response to the engine speed 15, and also uses intake pulse pressure of other cylinder groups if necessary as well as freely switches the practical length of the intake tubes to three kinds of L, l1, l2, so that intake efficiency may be improved. |
