Internal-combustion engines – Charge forming device – Including exhaust gas condition responsive means
Patent
1991-09-26
1993-11-23
Wolfe, Willis R.
Internal-combustion engines
Charge forming device
Including exhaust gas condition responsive means
123696, 123494, F02D 1908, F02D 4114, F02D 4500
Patent
active
052634647
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a fuel blending ratio detecting method for detecting the blending ratio of a mixed fuel supplied to an internal combustion engine.
BACKGROUND ART
Methanol is now noted as fuel giving rise to less environmental pollution, and methanol engines are also being developed now. However, immediate change-over of fuel used in all kinds of automotive vehicles from gasoline to methanol is almost impossible, and, at the time of change-over, a situation will occur where at least temporarily both the methanol fuel and the gasoline fuel are used.
With a view to deal with such a situation, introduction of a vehicle is proposed in which both the gasoline fuel and the methanol fuel can be used, that is, a vehicle which has the degree of freedom with respect to fuel to be used. (Such a vehicle will be referred to hereinafter simply as an FFV.)
In order that the engine of such an FFV can be accurately controlled, the blending ratio which is the mixing ratio of fuel between the gasoline and the methanol is to be continuously detected so as to execute various required controls on the engine. A blending ratio detecting device or sensor for use in such a purpose has been developed and is now in use and can be directly associated with the fuel supply system of the engine so as to directly detect the blending ratio of the fuel.
There is also a method for detecting the blending ratio by the use of an O.sub.2 sensor which generates the information of oxygen concentration in the exhaust gases of an engine, that is, the air/fuel ratio.
However, the practical use of the blending ratio sensor using a conventional photoelectric transducer is delayed due to the difficulty of temperature compensation that is frequently required due to frequent error and durability problems attributable to dirt progressively accumulating on the optical system.
On the other hand, in the case of the method using the O.sub.2 sensor, the blending ratio is computed by learning on the basis of the feedback from the O.sub.2 sensor. However, the blending ratio may not be detected as desired since this feedback learning control is not successfully attained until the driving conditions of the vehicle are more or less stabilized.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a fuel blending ratio detecting method capable of accurately detecting the blending ratio according to the operating conditions of an engine.
To attain the above object, the present invention provides a fuel blending ratio detecting method for an internal combustion engine having a blending ratio sensor disposed in a fuel feed path feeding fuel to the internal combustion engine so as to detect a first blending ratio of methanol, an O.sub.2 sensor generating information of an air/fuel ratio in exhaust gases from the internal combustion engine, the sensor output being increased or decreased with time relative to a rich/lean decision voltage, and fuel control means computing an air/fuel ratio feedback compensation coefficient by a method including at least an integral control of the output of said O.sub.2 sensor thereby regulating the quantity of supplied fuel so that an air/fuel ratio of the fuel mixture supplied to the internal combustion engine corresponds to a predetermined target value, comprising the steps of:
computing at intervals of a first predetermined period, a feedback learned value obtained as a result of said integral control on the basis of the factor of the feedback compensation coefficient, and multiplying the current blending ratio compensation coefficient by said feedback learned value to compute the next blending ratio compensation coefficient so as to compute a second blending ratio on the basis of said next blending ratio compensation coefficient;
computing a peak mean value of the current and preceding peak values of the feedback compensation coefficient each time peak values appear, and multiplying the current blending ratio compensation coefficient by said peak mean value to compute the next blend
REFERENCES:
patent: 4706629 (1987-11-01), Windland et al.
patent: 4909225 (1990-03-01), Gonze et al.
patent: 4945880 (1990-08-01), Gonze et al.
patent: 4986241 (1991-01-01), Inoue et al.
patent: 5163407 (1992-11-01), Yoshida et al.
patent: 5170763 (1992-12-01), Kitajima et al.
patent: 5178121 (1993-01-01), Kitajima et al.
patent: 5195497 (1993-03-01), Yoshida et al.
patent: 5197450 (1993-03-01), Kitajima et al.
patent: 5197451 (1993-03-01), Yoshida et al.
Iida Kazumasa
Kato Yoshihiko
Miyamoto Katsuhiko
Nanba Muneyoshi
Yokoyama Takanao
Mitsubishi Jidosha Kogyo Kabushiki Kaisha
Wolfe Willis R.
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