JPS606034A - Air-fuel ratio controller - Google Patents

Abstract

PURPOSE:To enable an air-fuel ratio to be controlled to an optimum value at all elevations when control of an air-fuel ratio is effected through feedback of an O2 sensor, by a method wherein a correction based on a detecting signal from an atmospheric pressure sensor is added to the value of a limit constant or a hold constant. CONSTITUTION:A control circuit 24 discriminates various conditions from the output signal of an O2 sensor 19, a water temperature, the number of revolutions of an engine, the negative pressure of a suction pipe, a time elapsing after the starting, etc., the condition of the O2 sensor 19 is decided from a feedback mode, in case it is in an active condition, a limit constant is determined, and in case it is in an inactive condition, a hold constant is determined. Thereafter, the digital value of an atmospheric pressure sensor 23 is read out, and each constant is corrected based on the digital value to determine a duty ratio. Correction of the constant is effected such that, in the case of properties in which a voltage value detected by the atmospheric pressure sensor 23 is high at a high elevation and low at a low elevation, a duty ratio to be controlled reverses, whereby the digital value is inverted, and a correction is calculated by computing a constant to the resultant value to add it to the correction. This permits an air-fuel ratio to be controlled to an optimum value at any elevation.

Description

Detailed Description of the Invention The present invention provides a three-way catalyst for exhaust gas purification in the viscous system.
- In engines that operate normally, the mixture air-fuel ratio is maintained near the stoichiometric air-fuel ratio at which the primary catalyst works most effectively, and in the condition fl, control is limited by a limit constant or the air-fuel ratio is fixed by a hold constant. Regarding air-fuel ratio control (II), in particular, setting constants such as limit constants and small-hold constants relative to altitude.

At high altitudes, the air density decreases as atmospheric pressure decreases, so if the constant for air-fuel ratio control is set the same as at 511 altitudes, the Sawaai air-fuel ratio will become over-enriched. This is unfavorable in terms of fuel efficiency, exhaust gas purification, etc. Therefore, the duty ratio of the duty signal that determines each constant is increased in steps at high altitudes to avoid excessive enrichment of the air-fuel ratio, which is limited or fixed. A method has been proposed to compensate for this, but since it is a stub-like correction, it is difficult to adequately cope with altitude changes.

Regarding the epidemic correction of the air-fuel ratio, conventionally, for example,
There is a prior art in G-29254, but this: I'
L 4; L Feedback control based on Q and ton I, which is a premise of the present invention, is not performed. In addition, this prior art is designed to control the negative pressure side of the suction pipe to the bowerage 1, which is frequently used at high altitudes, depending on the altitude, so it is difficult to correct the altitude under high loads such as when using the bowerage 1. limited to.

In view of these circumstances, the present invention linearly changes the constant set when controlling the air-fuel ratio using feedback control starting at 02 centigrade with respect to 8-stroke changes, and achieves the optimum air-fuel ratio in all 8 strokes. The purpose is to prompt the air-fuel ratio control device 5' to determine 1! (J4 t;

For this 1-1 objective, the present invention adds a correction value based on the detection signal from the atmospheric pressure sensor to the value of the limit (~ constant or Bold's constant) determined by various conditions, and calculates the value of each setting constant. The purpose of b is to determine the value.

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings.

To explain the outline of the apparatus of the present invention in FIG. An air correction passage 8 is connected to an air bleed 7 in the middle of a main fuel passage 6 leading to a nozzle 5 of a penbucolly 4. In addition, it branches from the main combustion 11'i1 passage 6 and has a thrower (hell valve 9).
An air correction passage 13 also communicates with the 1-abbreed 12 in the middle of the slow fuel passage 11 that opens near the 1-bows 1 to 10.

Each of these air correction passages 8 and 13 is provided with an opening/opening electromagnetic piece 14.15, and this ?h magnetic piece p14.
The suction side of 15 is connected to the main body through an air cleaner 16. Next, the bleed air on the downstream side of the engine body ↑117
A three-way converter 18 for converting the bleed gas to 61 is interposed, and 02t7 inverter 18 is installed on the engine body side.
9 is installed to detect the air-fuel ratio using oxygen in the IJI gas.
A 9-silicon sensor 20 is installed to detect the engine speed, a water temperature sensor 21 is installed on the engine body 2, and an engine rotation sensor 229 is installed. Each signal of the above 02 sentry 19 is controlled.
111 is input to the circuit 24, and a circuit is constructed to open and close the solenoid valves 14 and 15 at the dune 1-1 of the control circuit 24/t'l.

To explain the circuit of the human pressure sensor in Fig. 12, the popular 1i sensor 23 consists of a rose 23a and a potentiometer 231 for detecting atmospheric pressure, and it detects the voltage according to changes in atmospheric pressure. ” Outputs the log value.

Then, the signal of this atmospheric pressure sensor 23 is Δ-1)
△-1='' input to input 27 via river input 2511.

In addition, the issue number for the output of 1 set 27 is 1~
It is connected to the electromagnetic valve 14.15 via the circuit 28 that drives the right drive cylinder 28.

Here, in Microb [Colle → No. 27], the air-fuel ratio is χ with respect to the stoichiometric air-fuel ratio according to No.
Determine whether it is dry or not, and if it is strong, output a lean pressure signal with a large de-ray ratio and turn on the solenoid valve 14°1j.
J to I? i [i if increase the air force 1), make the air-fuel ratio leaner 4, or conversely, if Rv is low, output the Fj bow and increase the electromagnetic valve P14.15
By reducing the amount of air in the sleeve i1, the air-fuel ratio is made into a lip. In normal feedback control, each of the above credits is exchanged.
The main thing to do is to keep the air-fuel ratio near the stoichiometric air-fuel ratio, and limit it in the high load region!・Limit the Q2-T ratio by a constant.
Control the air-fuel ratio to 1]. On the other hand, in the inactive state of 02 sen 1 no 19, the bold constant is determined based on each value of water temperature, engine rotation, and suction pipe negative pressure, and the duer r ratio is fixed to maintain the air-fuel ratio at a specific value.

Next, the operation of the air-fuel ratio control device configured as described above will be explained using the flowchart shown in FIG.
, O> Sensor output 1'l J3 + Various conditions depending on water temperature, engine rotation, suction pipe negative F, time after startup, etc.
1 and d3 to F/+3 (feedback) t-do.
Then, judge the condition of 02 sen and activate it! The 1-state door determines the limit constant, and the inactive state door determines the Notold constant. Next, read the No' = r digital value of the popular 1i century, and based on this digital value - (multiply each constant - ("7" -) - - determine the di ratio. The correction is shown in Figure 4, 7 ("-Zatoichito,"
:Uni, the voltage value detected by the atmospheric pressure sensor is 11 (earth [
゛In the case of small characteristics at high altitudes, the D-L-Eye ratio that we try to control will be the opposite! Come, Digital 111■
is inverted, a constant is applied to that value to obtain a correction value, and the correction value is added to each preset value of the constant.

The constants of A: no eye ratio O%, 2()%, and 40%, which were determined under the conditions shown in Figure 5Q, are as shown in Figure 5(b). J, which increases in size with respect to the upper y1 of 8 melons, is changed linearly.

Incidentally, the change characteristics of each constant may be changed as shown by the broken line in FIG.
Of course, when the present invention is applied to air-fuel ratio control using 1JJ, t<J.

According to the present invention, J, sea urchin, which is clear from the above explanation, is 0
The air-fuel ratio is controlled by noise back control using
It changes linearly with the limit 1 to constant, hold constant, or high 1 change, so any 8
The air-fuel ratio can be optimally controlled even during rain, improving fuel efficiency and exhaust gas purification. In addition, since the signal from the popular Hshin I and L23 sends a 1 ri distance to the main station, the correction can be made to the FF Kaoru.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the apparatus according to the present invention, 8
r! Figure 2 (circuit diagram of the main part; Figures 3 and 4 are diagrams showing the operation; Figure 5 (c) is a diagram showing an example of the setting state of each constant; Figure (b) is a diagram showing an example of a constant change state. 14, 15...Air correction electromagnetic valve?, 19...02
Sensor, 2()... Negative pressure register 1, 21... Water temperature sensor, 22... Engine rotation sensor, 23... Atmospheric pressure Hinley, 24... Control circuit. Special feature 1 applicant Tomi (representative of T Heavy Industries Co., Ltd.) 11 people Benshinshi Ko (4 people) Ben 1!

Claims (1)

[Claims] ] - The air-fuel ratio is feedback-controlled by the 02 range set in the engine's I-I air system, or the air-fuel ratio is controlled by the limit constant and hold constant t211! In the control device, what is the atmospheric pressure sensor that outputs the signal according to the popularity?
! Limit constant, small-hold constant against altitude change-)
The air-fuel ratio control device is characterized by being developed in such a way that it changes to 1.