| 摘要 |
PROBLEM TO BE SOLVED: To provide a device capable of flow rate control of a fuel pump similarly to a mechanical returnless fuel system, requiring no cross-coordination with a vehicle ECU, requiring no communication with the vehicle ECU, reducing consumption of electrical energy and reducing noise, vibration and harshness. SOLUTION: The returnless fuel system has a fuel pump 20 whose flow rate is varied by varying the applied voltage. Flow rate control of the fuel pump entails sensing the back pressure with a pressure sensor 92 that lies between a jet pump supply orifice 70 and a pressure regulator 62. A trigger circuit routine 100 calculates the absolute value of a difference between the sensed back pressure and an average pressure and compares it to a predetermined back pressure. When the absolute value is greater than the predetermined back pressure, the sensed pressure is compared to a high threshold pressure and a low threshold pressure by a control circuit routine 108, and based on the comparison result, the flow rate of the fuel pump 20 is varied or maintained such that the mean fuel pressure is targeted under fuel consumption conditions. COPYRIGHT: (C)2008,JPO&INPIT
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