| 摘要 |
PURPOSE:To accurately measure intake air amount without being affected by the pulsation of negative pressure, by detecting the negative pressure in the completion of intake stroke when intake air amount in a multiple cylinder engine having a variable length intake path is detected on the basis of intake negative pressure. CONSTITUTION:Independent intake pipes 2-7 of respective cylinders join in surge tanks 10, 12, and intake paths 20, 22 divided into 2 groups join in an intake path having a throttle valve 24 upstream of said paths 20, 22. Switch valves 14, 18 are interposed respectively between surge tanks 10, 12 and paths 20, 22 to be opened and closed by a control unit 40 according to the rotational frequency of an engine. To measure intake air amount for fuel injection quantity control or the like, negative pressure in the surge tanks 10, 12 is detected by pressure sensors 36, 38 to measure said intake air amount in the control device 40 according to the rotational frequency, while intake negative pressure is selected to reach a value near the completion of intake stroke in each cylinder to provide detected negative pressure by a tachometer of a crankshaft 28. |
