FUEL PRESSURE CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a fuel pressure control device for an internal combustion engine capable of suppressing an excessive rise in actual fuel pressure beyond a target value according to erroneously excessive increase in an integration term when the fuel discharge amount of a fuel pump is a value in the vicinity of a maximum value. SOLUTION: Fuel pressure within a delivery pipe 53 is controlled by controlling fuel discharge amount of a high pressure fuel pump 47 based on a duty ratio DT calculated from an integration item DTi. The integration item DTi is updated based on a difference of actual fuel pressure P and target fuel pressure P0. The integration item DTi is gradually updated toward a side (increase side) in which the integration item DTi increases fuel discharge amount of the high pressure fuel pump 47 under the circumstances that it takes time to raise actual fuel pressure P up to the target fuel pressure P0. But when fuel discharge amount of the high pressure fuel pump 47 becomes a value in the vicinity of the maximum value, the update of the integration item DTi is inhibited and excessively increasing side value of the integration item DTi is avoided.