| 摘要 |
PURPOSE:To enhance output power through an intake device in which the length of an intake pipe downstream to a surge tank is variable, by altering the length of the intake pipe to maximize the intake pressure immediately before the end of intake stroke in a cylinder. 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 connectes 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. Expansible and compressible pipes 11 provided with racks 11a are fitted in the branch intake pipes 5 so that the pipes 11 can be moved back and forth by the rotation of a pulse motor 12 through gears 12b engaged with the racks 11a. The pulse motor 12 is regulated by a control means 13 depending on the output signal of a pressure detection means 14 for detecting the fluctuation of pressure in the intake pipe and that of an intake detection means 15 for detecting the intake stroke in the cylinder 2, to set the intake pipe at such a length as to maximize the intake pressure immediately before the end of the intake stroke. |
