JPH02107746U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is a complaint correspondence diagram of this invention, Fig. 2 is a system diagram of an embodiment of this invention, Fig. 3 is a block diagram of a control unit of this embodiment, and Fig. 4 shows the calculation contents of this embodiment. A flowchart for explanation and FIG. 5 is a waveform diagram of α for explaining the operation of this embodiment. FIG. 6 is a flowchart for explaining the calculation contents of the conventional example, FIG. 7 is a line diagram showing the integral characteristic of the conventional example, and FIG. 8 is a waveform diagram for explaining the action during transients of the conventional example. FIG. 9 is an area diagram for explaining the learning area. DESCRIPTION OF SYMBOLS 1... Engine load sensor, 2... Engine rotation speed sensor, 3... Basic injection amount calculation means, 4... Air-fuel ratio sensor, 5... Deviation measurement means, 6... Reversal determination means,
7... Elapsed parameter measuring means, 8... Judgment criterion setting means, 9... Small/medium/large determining means, 10... Integral constant setting means, 11... Air-fuel ratio feedback correction amount calculating means, 12... Learning value storage means, 13... Learning value Reading means, 14... Fuel injection amount determining means, 15... Learning condition determining means, 16... Learning value updating means, 17... Judging means, 18... Learning value updating means, 23... Throttle valve, 24... Air flow meter, 25... Crank Angle sensor, 26...Oxygen concentration sensor (air-fuel ratio sensor), 35...Fuel injection valve, 40...Control unit.

Claims (1)

[Scope of utility model registration request] A sensor that detects the load and rotational speed of the engine, a means for calculating the basic injection amount according to these detected values, a sensor that detects the actual air-fuel ratio, and a sensor that detects the detected air-fuel ratio and a predetermined target air-fuel ratio. A means for measuring the deviation from the fuel ratio, a means for determining whether the magnitude relationship between the two air-fuel ratios has been reversed, a means for measuring an integrated parameter after the reversal each time this is determined, and a means for comparing the integrated parameter with the measured value. means for presetting judgment criteria for the measurement; means for determining whether the measurement value is small, medium, or large by comparing the judgment criteria with the measured value; and when the judgment result is small, a small integral means for setting a large integral constant when the constant is medium, and a small integral constant when the constant is large, and calculating a feedback correction amount of the air-fuel ratio by including at least an integral calculated from these integral constants and the deviation. means for storing learning values for each area divided using engine load and rotational speed as parameters; means for reading learning values for the area to which the engine load and rotational speed belong at that time; means for determining the fuel injection amount to be output by correcting the basic injection amount using the learned value and the feedback correction amount, and the learning condition that the operating conditions are in the same area as the previous time and in a steady state are established. means for determining whether the learning condition is the same, means for updating the learned value for the area based on the feedback correction amount and the read learning value for the area when this is determined; means for determining whether the learning condition is satisfied and the determination result is medium or large; An air-fuel ratio control device for an engine, comprising means for updating a learned value separately from updating the learned value.