JPS60104737A - Contrtoller for air/fuel ratio measuring and adjusting apparatus of internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a control device for an air/fuel ratio regulating device for an internal combustion engine.

[Background of the invention]

The determination of the air/fuel ratio during operation of an internal combustion engine by detecting and measuring combustible or combustion-supporting components in the exhaust gas of the engine has been proposed, for example, in our pending UK patent application 8216444. has been done. The measurements obtained are used to make adjustments to bring the air/fuel ratio to the desired level. In this method of detecting combustion supporting components, an auxiliary fuel such as butane is used. In order to avoid frequent replacement of the small container in which the auxiliary fuel is contained, it is desirable to keep the consumption of the auxiliary fuel to a minimum when there is a reasonable tendency to require adjustment. air/fuel ratio measurement and adjustment equipment.
It is desirable to control the operation of the fuel ratio measurement and adjustment device. As a general rule, the IEI operates its measuring and adjusting device once when using an internal combustion engine, and when the altitude of the land on which the vehicle equipped with the internal combustion engine is located changes significantly. It is desirable to operate The air/fuel ratio changes due to changes in air pressure with changes in altitude and thus requires adjustment.

[Summary of the invention]

The object of the invention is to provide a control device for an air/fuel ratio measuring and regulating device of an internal combustion engine that operates on a nearly daily basis.

The pending UK patent application No. 8321175, filed by Honmaru IQ applicant on the same day as the pending UK patent application which forms the basis of the priority claim of this application, corresponds according to the change in altitude. It is about movement.

According to the present invention, an ambient temperature sensor, an engine coolant temperature sensor, and means for initiating air/fuel measurement in response to an engine coolant temperature that does not exceed the ambient temperature by more than a predetermined value are provided. A control device for an air/fuel ratio measuring and regulating device of an internal combustion engine is provided. During normal vehicle use, the coolant temperature gradually decreases toward ambient temperature several times a day while the engine is not running, but it takes several hours to reach within 5°C of ambient temperature. It takes. Therefore, if the vehicle is used several times a day, the coolant temperature will not approach ambient temperature during the day. In contrast, if the vehicle is left overnight, the coolant temperature will drop to near ambient temperature, and as the air temperature rises in the morning, the coolant temperature may drop to below ambient temperature. .

Therefore, by performing air/fuel ratio measurements only when the cooling water temperature is close to ambient temperature or when the cooling water temperature is lower than ambient temperature, measurements will be performed approximately once a day. .

The controller includes means for measuring engine intake throttle opening, engine speed, and absolute intake manifold pressure, and a means for measuring engine intake throttle opening, engine speed, and absolute intake manifold pressure, and the measured throttle opening by extracting predicted intake manifold pressure from stored information. and means for obtaining and storing the ratio of the predicted manifold pressure to the actual measured manifold pressure, and thereafter obtaining the predicted manifold pressure. and means for comparing the ratio of the actual measured manifold pressure to a previously determined ratio; and means for initiating the air/fuel measurement in response to a predetermined degree of change in said pressure ratio. Be prepared. In this way, the pressure above to measure the intake manifold pressure? (This pressure sensor is also needed for other purposes) serves as the basis for providing a measurement of barometric pressure, thus avoiding the need for a separate barometric pressure sensor.

This control device includes means for detecting engine operating parameters to direct vehicle operation in normal cruise mode, and for air/fuel ratio measurements except when the vehicle is operating in normal cruise mode. As much as possible, it should also include means to prevent the start of the process.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, a central processing unit 1 constituted by a digital microgross processor is connected to receive signals from the following signal sources.

(,)Engine coolant temperature sensor 2oThis engine coolant temperature sensor 2 can be the same sensor as the sensor used to instruct the driver about the coolant temperature, but it can handle temperature changes in the 2°C range. (b) Ambient temperature sensor 3 The measurement accuracy of this ambient temperature sensor 3 must be the same as that of the cooling water temperature sensor, and the measurement accuracy of the ambient temperature sensor 3 must be the same as that of the cooling water temperature sensor. The ambient temperature sensor 3 must be located away from local heat sources such as the brakes and the engine itself, and where it cannot be overheated by solar heat above normal ambient temperature. ,) Throttle angle sensor 4° This throttle angle sensor 4 is required to measure the throttle opening. However, in the case of a sliding throttle, this throttle angle sensor is Do not measure degrees.

(d) Engine speed sensor 5° (e) Absolute intake manifold pressure sensor 60 In a precisely controlled fuel metering device of an internal combustion engine, the amount of fuel supplied is controlled according to the absolute intake manifold pressure, so that the absolute intake manifold pressure Sensors are a normal part of the fuel system.The central processing unit 1 relates the expected manifold pressure to engine speed and throttle opening when operating at sea level, which is normal atmospheric pressure. , also receives stored data. That data can be determined, for example, by calibrating the test engine. Only a limited amount of data needs to be stored in order to provide a rough measurement of barometric pressure changes, since recalibration is required only if there is a large change in altitude, for example 300 m. When a given value of the engine speed and a given value of the throttle opening are supplied from the central processing unit 1,
The controller provides predicted values of manifold pressure to the central processing unit 1 in response to those values.

The central processing unit 1 provides its output to the air/fuel ratio sensor 7. As the air/fuel ratio sensor T, a sensor that measures the leanness of the air-fuel mixture by burning auxiliary fuel in the exhaust gas and measuring the exothermic effect of the combustion can be used. The output provided from the central processing unit 1 to the air/fuel ratio sensor 7 only initiates the operation of the air/fuel ratio sensor 7.

The detected air/fuel ratio value is provided to the central processing unit 1. If the air/fuel ratio is appropriate, the central processing unit 1 provides a signal to the air/fuel ratio controller 8 to adjust the air/fuel ratio to the desired level.

Next, the basic operations performed inside the central processing unit 1 will be explained with reference to FIG. When the engine is started, the coolant temperature is compared to the ambient temperature, and if the coolant temperature is not greater than t°C higher than the ambient temperature (block 10), operation proceeds to point A. As will be explained later, air/fuel ratio measurement is started at point A.

If the cooling water temperature is more than t° C. higher than the ambient temperature, operation proceeds to altitude detection mode (block 11).

In this altitude detection mode, throttle opening, engine speed, and manifold pressure are measured and a calibrated manifold pressure is determined for the measured engine speed and throttle opening. Then, in block 12, the ratio of the measured manifold pressure to the stored calibration value is obtained as 0 to give the current barometric pressure measurement. The ratio of the value to 9 is calculated as the value of 9 to give the current atmospheric pressure measurement. This chi value is compared to a value previously recorded and stored for that chi ratio, representing the barometric pressure at which the last calibration was performed (block 12).

There is an inherent delay in this comparison of approximately 200 seconds. If this change exceeds a given pressure difference ΔP, the operation proceeds again to point A (block 13).

If there is no large pressure change, the initial monitoring operation is repeated at 200 second intervals until a large pressure change is measured, indicating a change in altitude. (1) Has the cooling water temperature reached a normal temperature, especially t2°C or higher (block 14)?

01) Is the intake manifold pressure within a range indicative of normal cruise-e-mode vehicle operation (block 15)?

(lit) Is the engine speed within a range indicating operation of the vehicle in normal cruise mode (block 16)?

(1v) Is the throttle opening within a range that indicates operation of the vehicle in normal cruise mode (block 17)?

(,) Is the rate of change in throttle opening less than a predetermined level (block 18)? In order to measure such a rate of change, the throttle opening is detected at regular predetermined frequency intervals,
It is more convenient to compare the current indicated value with the previous indicated value and take a low rate of change when the difference between these two indicated values is less than or equal to a predetermined value.

If all the results of the above five types of inspections are positive,
Calibration is initiated (block 19), in which the air/fuel ratio sensor is activated and, if the measured ratio differs significantly from the desired stored value, the air/fuel ratio controller is activated. Change the Air/Fuel Ratio 0 If the result of class 1s of the five types of inspections (1) to (v) is negative and no calibration has been performed since the vehicle was started, the operation will be at point A. From there, the action is reversed.

Immediately after a calibration has been performed, or if the various sensors indicate that the vehicle is not in normal cruise mode and remains at the previously performed calibration (block 20), operation returns to the starting point. .

It can be seen that whenever the engine coolant temperature is low when the engine is started, engine calibration occurs immediately upon reaching normal cruise conditions. Engine calibration is not performed until the coolant temperature reaches normal operating levels. Assuming the coolant temperature is 1° C. above the low level (i.e. above the temperature representing the first start of the day), a comparison is made between the current pressure and the previous pressure when starting the engine, and Subsequent calibrations are only performed if there has been a significant change in air pressure since the last calibration was performed. In this way, calibration is performed only when necessary, but the auxiliary fuel used during calibration lasts for a long time as a result of the very limited number of calibrations.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic components used in the present invention, including the central processing unit, and FIG. 2 is a flowchart showing the characteristics of the operations performed in the central processing unit. 1...Central processing unit, 2.轡・Φ Cooling water temperature sensor, 3...φ ambient temperature sensor, 4... Throttle angle sensor, 5. Fist/ψ engine speed sensor, 6. e@ Φ
Absolute intake manifold pressure sensor, T...Φ air/fuel ratio sensor, 8... air/fuel ratio controller. Patent Applicant: Austin Lawvaer Group Limited Agent Masaki Yamakawa (and 2 others) Cleaning of drawings (no change in content) Procedural amendment (with lambda) To the Commissioner of the Japan Patent Office 59.12.20 1. Regarding the case Indication 1989 48 Patent Application No. 1 gz'l' (Relationship with Case No.
D. Sof. 7F “ヮ, □ Eye 1” 1939 1
January 2] Nissho Ushitoi Yuzu Yozokan ・6. Engraving of drawings subject to amendment (no change in content)

Claims (1)

[Claims] (11) An ambient temperature sensor, an engine coolant temperature sensor, and means for starting air/fuel measurement in response to an engine coolant temperature that does not exceed the ambient temperature by a predetermined value. A control device for an air/fuel ratio measurement and adjustment device for an internal combustion engine, characterized in that it comprises: (2. The control device according to claim 1,
Means for measuring engine intake throttle opening engine speed and absolute intake manifold pressure and corresponding to measured throttle opening and engine speed by extracting predicted intake manifold pressure from stored information. and means for obtaining and storing the ratio of the predicted manifold pressure to the actual measured manifold pressure; and means for initiating an air/fuel measurement in response to a predetermined degree of change in the pressure ratio. control device. (3) The control device according to claim 1 or 2, wherein the vehicle is running in a normal cruising mode before starting air/fuel measurement, and such normal cruising mode is provided. A control device characterized in that a check is performed to confirm that measurements are started only during cruise mode. (4) The control device according to claim 3,
A control device characterized in that elements measured to confirm running in normal cruise mode include engine speed, manifold pressure, and throttle opening. (5) The control device according to claim 4,
A control device characterized in that said elements also include engine cooling water temperature. (6) The control device according to claim 4 or 5, wherein the element also includes a rate of change in throttle opening.