Patent ID: 7438051
Filing Date: 2008-10-21
Classification: F02D

Abstract:
1. A method for supplying fuel to an internal combustion engine, comprising the steps of: delivering fuel by a low-pressure pump and a high-pressure pump to the internal combustion engine, wherein the low-pressure pump provides a delivery volume of fuel for the high-pressure pump and generates a preliminary pressure, which is applied to the high-pressure pump and the high-pressure pump provides the delivery volume with an injection pressure into an injection system of the internal combustion engine; adjusting the preliminary pressure to a variable desired preliminary pressure that is determined using the vapor pressure curve of a fuel, regulating the injection pressure using a high-pressure regulator, and correcting a control value of the low-pressure pump, which control value corresponds to the desired preliminary pressure, using an adaptation value, determining the adaptation value in an adaptation mode, in which the preliminary pressure is changed until vapor bubbles are formed in front of the high-pressure pump, the formation of vapor bubbles is detected by means of the change in the regulator response of the high-pressure regulator, and upon the detection of vapor bubbles, current process parameters are determined, from which the adaptation value is derived, wherein a desired preliminary pressure is adjusted, which is higher than the vapor pressure of the fuel, and wherein the preliminary pressure is changed in the adaptation mode by impressing an oscillation upon that control value of the low-pressure pump that corresponds to the desired preliminary pressure.