| 摘要 |
PURPOSE:To enable a hot wire sensor in an air by-pass at the Venturi part of an intake passage to always exactly detect the flow rate of intake air, by providing a diaphragm unit upstream to the hot wire sensor. CONSTITUTION:A hot wire sensor 6 is provided halfway in an air by-pass 5 which connects the part of an intake passage 2 upstream to its Venturi part 4, to the narrowest section of the Venturi part. A fuel injector is controlled depending on the flow rate of air which is determined from the output of the sensor 6. The diaphragm chamber 29 of a diaphragm unit 30 is provided as a surge tank in the air by-pass 5 upstream to the hot wire sensor 6. An atmospheric pressure chamber 27 is defined on one side of a diaphragm 26, on the other side of which the diaphragm chamber 29 is defined. The atmospheric pressure chamber 27 is open to the atmosphere through an atmosphere hole 28. The diaphragm unit 30 functions to absorb the pulsation, if any, of intake pressure at the time of full opening of a throttle valve 3 to enable the exact detection of the flow rate of air. |
