Apparatus for learning control of air-fuel ratio of air-fuel mix

Internal-combustion engines – Charge forming device – Fuel injection system

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

123480, F02M 5100

Patent

active

046551883

DESCRIPTION:

BRIEF SUMMARY
TECHNICAL FIELD

The present invention relates to an apparatus for controlling the air-fuel ratio of an air-fuel mixture in an internal combustion engine provided with fuel injection means opened and closed in an on-off manner by a driving pulse signal given by electronic control means. More particularly, the present invention relates to an air-fuel ratio controlling apparatus in which the variable of the air-fuel ratio controlled by the apparatus is learned and the respondency of the control of the air-fuel ratio in the same engine-driving state is improved and in which the learned value of an engine-driving state area of a lower degree of the advance of learning is estimated from other engine-driving state areas and the smoothness of the air-fuel ratio in the boundary between a plurality of engine-driving state areas the degree of the advance of learning is improved.


BACKGROUND TECHNIQUES

An electronically controlled fuel injection valve is opened by a driving pulse signal (injection pulse) given synchronously with the rotation of an engine and while the valve is opened, a fuel is injected under a predetermined pressure.
Accordingly, the injection quantity of the fuel depends on the period of opening of the valve, that is, the injection pulse width. Assuming that this pulse width is expressed as Ti and is a control signal corresponding to the injection quantity of the fuel, Ti is expressed by the following equations: injection quantity of the fuel, which is called "basic fuel injection quantity" for convenience, K stands for a constant, Q stands for the flow quantity of air sucked in the engine, N stands for the rotation speed of the engine, COEF stands for various correction coefficients for correcting the quantity of the fuel, which is expressed by the following formula: fuel as the water temperature is lower, Kas stands for a correction coefficient for increasing the quantity of the fuel at and after the start of the engine, Kai stands for a correction coefficient for increasing the quantity of the engine after a throttle valve arranged in an intake passage of the engine is opened, Kmr stands for a coefficient for correcting the air fuel mixture, and Ketc stands for other correction coefficient for increasing the quantity of the fuel, .alpha. stands for an air-fuel ratio feedback correction coefficient for the feedback control (.lambda. control), described hereinafter, of the air-fuel ratio of the air-fuel mixture, and Ts stands for the quantity of the voltage correction for correcting the change of the flow quantity of the fuel injected by the fuel injection valve, which is caused by the change of the voltage of a battery.
In short, the desired injection quantity of the fuel is obtained by multiplying the basic fuel injection quantity Tp by various correction coefficients COEF, and when a difference is brought about between the aimed value to be attained by the control and the actual controlled value, this difference is multiplied by .alpha. to effect the feedback control and the correction for the power source voltage is added to the feedback control.
The feedback control of the air-fuel ratio will now be described. An exhaust component concentration detecting member, for example, an O.sub.2 sensor for detecting the oxygen component in the exhaust gas, is attached to an exhaust passage to detect the actual air-fuel ratio .lambda. of the air-fuel mixture sucked in the engine, and by comparing with a slice level, it is judged whether the actual air-fuel ratio .lambda. is richer or leaner than the aimed air-fuel ratio .lambda.t. When a known ternary catalyst for efficiently converting CO, HC and NO.sub.x, the main three exhaust gas components, at the theoretical air-fuel ratio is arranged in the exhaust system, the above-mentioned aimed air-fuel ratio .lambda.t is equal to the theoretical air-fuel ratio. Accordingly, in this case, by the slice level, it is judged whether the actual air-fuel ratio is richer or leaner than the theoretical air-fuel ratio, and the injection fuel quantity expressed by Tp

REFERENCES:
patent: 4466410 (1984-08-01), Sakakibara et al.
patent: 4467770 (1984-08-01), Arimura et al.
patent: 4539958 (1985-09-01), Ito et al.
patent: 4561400 (1985-12-01), Hattori
patent: 4566420 (1986-01-01), Sakamoto et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Apparatus for learning control of air-fuel ratio of air-fuel mix does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Apparatus for learning control of air-fuel ratio of air-fuel mix, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for learning control of air-fuel ratio of air-fuel mix will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1079943

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.