TH43022B - Fuel injection system of internal combustion engine - Google Patents

Abstract

DC60 (28/11/56) classifies variations in fuel injection correction amounts in internal combustion engines for all factors. The first learned correction factor and the second learned correction factor are read out and reflected in KBUR and KALT, which are feedback correction factors for feedback fuel injection control. The baseline fuel injection amount is calculated referencing Map 40. The feedback correction factor is corrected at a predetermined cycle based on O2 density. The baseline fuel injection amount is multiplied by the feedback correction factor, and the final fuel injection amount is determined to approximate the ideal air-fuel ratio when the KBUK variation is less than plus or minus 5%, and the difference between KBUK and KBUKOLD is more historical. When the KBUK variation is greater than a positive or negative 3%, KBUK is recorded as the first learned correction factor at a predetermined time (Step S8). When the KBUK variation is greater than a positive or negative 5% and greater than a positive or negative 3%, KBUK is recorded as the second learned correction factor (Step S12).

Claims (5)

OCR 08PV 1. The fuel injection system of an internal combustion engine comprises: a read path that reads the first learned correction factor and the second learned correction factor, which are sequentially recorded in a non-volatile memory unit and reflect their effects in the feedback correction factor for fuel injection control; a base injection quantity calculation path that calculates the base fuel injection quantity based on the throttle angle and engine speed, referencing the base fuel injection map provided in the intake system of the internal combustion engine and the engine speed of the internal combustion engine; a feedback correction factor calculation path that corrects the feedback correction amount at a predetermined cycle based on the output signal from the O2 sensor provided in the exhaust system; and a final fuel injection quantity calculation path that multiplies the base fuel injection quantity by the feedback correction factor and determines the final fuel injection quantity as close as possible to the final quantity. The target air-to-fuel ratio and the feedback-learning correction factor storage pathway store the feedback correction factor in non-volatile memory at a predetermined time as the first learned correction factor under a condition where the variation of the feedback correction factor is less than the first threshold, and store the feedback correction factor in non-volatile memory as the second learned correction factor under a condition where the variation of the feedback correction factor is greater than the second threshold. 2. The fuel injection system of an internal combustion engine under claim 1, which includes a historical data storage pathway that stores feedback correction factors, or the average of those factors including historical data prior to activation of the injection control system, in non-volatile memory at a predetermined historical time, where the feedback correction factor storage pathway stores the feedback correction factor in non-volatile memory as the first learned correction factor, when the variation of the feedback correction factor is less than the first threshold, and furthermore, the difference between the historical data prior to activation of the vehicle's injection control system and the feedback factor at that time is greater than the baseline threshold for comparison at a predetermined time. 3. The fuel injection system of an internal combustion engine under claim 2, which has been processed to store a feedback correction factor in volatile memory, is not a learned correction factor, the first, after the internal combustion engine water temperature exceeds a predetermined threshold. 4. The fuel injection system of an internal combustion engine under clause 1, where the feedback learning correction factor storage pathway stores the feedback correction factor in volatile memory as a second learned correction factor, when the variation of the feedback correction factor exceeds the second threshold, and furthermore, the variation of the feedback correction factor, or the average of those variations, exceeds the predetermined threshold for changes in the environment after activation of the vehicle's injection control system. 5. The fuel injection system of an internal combustion engine under claim 4, which has been processed to store a feedback correction factor in volatile memory as a second learned correction factor after the water temperature of the internal combustion engine exceeds a predetermined threshold value.