JPS5826218A - Measuring method for quantity of intake air for electronically controlled engine - Google Patents

Abstract

PURPOSE:To measure the quantity of intake air of a controllable engine smoothly by operating the quantity of air in accordance with the quantity of air measured with an air flowmeter provided in an intake passage and the quantity of air measured from the pressure in an intake pipe and the number of revolutions of the engine. CONSTITUTION:An air flowmeter 14 and an intake pressure sensor 22 are provided to the intake passage 12 of an engine 10, and the output thereof is inputted to a digital electronic control circuit 56 which controls a fuel injection rate 30, an ignition timing 34, a recirculation rate 52 for exhaust gas, etc. of the engine. The output of a crank angle sensor 40 provided to a distributor 36 is inputted to a control circuit 56. The circuit 56 operates the fuel injection rate, the ignition timing and the recirculation rate of exhaust gas by taking the quantity Q1 of intake air from the air flowmeter 13 as quantity Q of intake air when the Q1 is below the prescribed value and by determining the quantity Q2 of intake air from the sensors 22 and 40 when the Q1 is above the prescribed value and taking the product of the average value of the ratio between the previously measured Q'1 and Q'2 as the quantity Q of intake air, thereby controlling the engine easily.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the amount of intake air in an electronically controlled engine, and more particularly, to a method for measuring the amount of intake air in an electronically controlled engine, particularly for use in automobiles that controls the amount of fuel injection, ignition timing, amount of exhaust gas recirculation, etc. according to the amount of intake air. Electronic control engineering/
The low intake air amount region suitable for use in engine/engine is the first intake air amount 'ft determined from the output of the air flow meter installed in the intake passage, and the high intake air amount region is the intake air amount of the engine. ,
0 Concerning an improvement in a method for measuring the intake air amount of an electronically controlled engine in which the second intake air amount determined from the intake pipe pressure downstream of the nine intake throttle valves and the engine speed is used as the engine intake air amount. In recent years, electronic control circuits have been used to control fuel injection amount, ignition timing,
Electronically controlled automobile engines that control the amount of exhaust gas recirculation and the like have been put into practical use.

There are various types of this electronic control engine/, but among them, the low intake air region is the #11 intake air amount t determined from the output of the air flow rate needle such as an air meter installed in the intake passage.
The amount of intake air is a The amount of fuel injection, ignition timing,
An electronically controlled engine has been proposed that controls the amount of exhaust gas reintroduction. -lower than when the first Q intake air amount is the engine intake air amount, or when the second intake air amount is the engine intake air amount over the entire intake air amount range. Intake air amount range, suitable for high intake air amount range.9 Using intake air amount, fuel injection amount, ignition timing,
It has the feature that the amount of exhaust gas recirculation, etc. can be controlled.

However, normally, the first intake air amount and the second intake air amount do not necessarily match even at the same time due to manufacturing tolerances of sensors such as an air flow meter or an intake pipe pressure gauge. When the 10th intake air amount, which is determined from the output of the 9th air flow rate needle disposed in the intake passage, exceeds a predetermined value, the intake pipe pressure downstream of the intake throttle valve and the engine speed increase. When switching to the second intake air amount calculated from
The measured intake air 1li-AX changes discontinuously. Therefore, the fuel injection amount calculated from the intake air amount,
Ignition timing, exhaust gas recirculation amount, etc. also change discontinuously, causing breathing, surging, etc., and deteriorating vehicle driving performance.

Additionally, in order to deal with differences in the amount of intake air for each individual engine due to engine manufacturing tolerances, the method of determining the amount of intake air from the output of an air flow meter installed in the intake passage generally eliminates the difference as described above. However, in the method of determining the amount of intake air from the intake pipe pressure on the downstream side (intake throttle valve) and the engine speed, the difference will occur. Therefore, in the high intake air amount range,
Problem 1: Differences occur in fuel injection amount, ignition timing, exhaust gas recirculation amount, etc. for each individual engine, resulting in an increase in the amount of harmful components released or an increase in fuel consumption. did.

The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional art, and it is possible to adjust the fuel injection amount, ignition timing, and exhaust gas amount over the entire intake air amount range from the low intake air amount area to the high intake air amount area. By controlling the engine speed accurately and smoothly, it is possible to absorb individual differences between engines.
Therefore, it is an object of the present invention to provide a method for measuring the intake air amount of an electronically controlled engine, which can suppress fuel consumption and the amount of harmful components released, and ensure good engine performance. The first intake air amount, which is located in the intake passage and determined from the direction of the nine air flow rate needles, is the intake air amount of the engine. In the method for measuring the intake air amount of an electronically controlled engine in which the second intake air amount obtained from the side intake pipe pressure and the man rotation number is used as the intake air amount of the engine, the low intake air amount region is The average value of the ratio of the intake air amount to the intake air amount of the irises 2 is determined and stored, and the first intake air amount is taken as the intake air amount of the engine, and the high intake air amount region is defined as the intake air amount of the 82 above. The value obtained by multiplying the air amount by the above average value tllllr
The above object has been achieved by reducing the upper air amount to the inlet air amount. ◎ Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1 and FIG. 2, this embodiment includes an air meter 14 that can be provided in the intake passage 12 of the engine 100 and outputs an electric signal 1 in response to the intake air temperature; It has an intake air temperature sensor 16, which is provided on the upstream side of the meter 14 and outputs an electric compensation J6 according to the intake air temperature, and a pressure sensitive part that communicates with the intake pipe 2o downstream of the intake throttle valve 18. and outputs electric signal f according to the pressure of v&ki f20 [! ! [By the pressure sensor 22 and the fuel pump 26 from the fuel tank 24] The fuel that has been pumped is pumped! The injector 3o that injects into the nitrogen holder 28 and the engine/combustion chamber 3
Spark plug 3 for igniting the air-fuel mixture introduced into 2
-4 and the secondary ignition generated by the ignition coil 38 in accordance with the rotation of the distributor shaft 36Jl driven by the engine crankshaft ([not shown)], the ignition plug disposed in each cylinder of the engine. The distributor 36 has a built-in crank angle sensor 40 that distributes and supplies the oil to the exhaust manifold 42 and listens to an electric signal corresponding to the machine rotation speed according to the rotation of the distributor shaft 36a+O1l, and the exhaust manifold 42. An oxygen concentration sensor 44 is provided on the side and outputs an electrical signal according to the residual oxygen concentration in the exhaust gas, and a cooling water temperature sensor is provided on the engine block 46 and outputs an electrical signal according to the engine cooling water temperature. 48 and an exhaust gas recirculation passage (hereinafter referred to as the FiGR3l passage) 50 that communicates the exhaust manifold 42 and the intake pipe 20, and controls the amount of exhaust gas recirculation (hereinafter referred to as the 113GR amount). The recirculation amount control valve (hereinafter referred to as BGR valve) 52, the battery 54, and the low intake air amount region where the intake air amount is less than a predetermined value are controlled by the first
The intake air amount is defined as the intake air amount Qltll, and the high intake air amount region where the intake air amount is equal to or higher than the predetermined value is determined by
22tH force intake pressure sensor and the crank angle sensor 4
(Second intake air amount Q2t found from the engine speed found from the 13 force - Calculate the fuel injection amount, ignition timing, exhaust gas recirculation amount, etc. as the engine intake air amount, and , the injector 30q ignition 'il 38
, ] [a In a well-electronically controlled engine equipped with a digital electronic control circuit s6 that controls the G R valve 52, etc., the digital electronic control circuit s6 controls a low intake air amount in which the first intake air amount Q1 is equal to or less than a predetermined value. is the first intake air amount Q
1 and the second intake air amount Q2 and store it, and also calculate the average value K of the ratio of the first intake air amount Q 1 tfl
lHe) Ilk human air volume, and the high intake air volume range is calculated by multiplying the second intake air volume Q2 by the average value K to obtain 900 million KXQ.
The fuel injection amount, ignition timing, exhaust gas recirculation amount, etc. are determined as the intake air amount of the 2'i engine, and the injector 30, ignition valve 38, EGR valve 52, etc. are controlled accordingly. In the figure, 58 is an exhaust pipe, and 60 is a grounding wire for grounding the digital electronic control circuit 56. The electronic control circuit 56 is an air flow meter, as shown in detail in Figure 1/PJ2. 14. The analog signals of the intake temperature sensor 16, intake pressure sensor 22, cooling water temperature sensor 48, and battery 54 are converted into digital signals suitable for calculation processing.
LF conversion, multiplexer function, 9 analog-to-digital conversion 1162, and the above 2 ink angle sensor +40 and! ! The digital signal output from the bulk concentration sensor 44 is taken into the digital electronic control circuit 56 at a timing suitable for arithmetic processing, and the calculation results calculated in the digital electronic control circuit 56 are taken in at a timing suitable for output. Said injector 3G, ignition: 2 i#8g and PSGBI valve 82
Equipped with an input/output interface 7 ace circuit 64 with a KH5 input/output buffer function and a crystal oscillator efJat!
A central processing unit 66 consisting of a microprocessor, a read-only memory 68, and a random access memory 7
0 and a path 72 connecting each component.
The function below 0 which is ll1 will be explained. Intake passage 12
The intake air taken in from the intake port 12 is guided to the intake pipe 20 after its amount is adjusted by the air intake throttle valve 18, which outputs an electric compensation J# according to the amount. - The intake pressure sensor 22 outputs a good electrical signal to the digital electronic control circuit 56 in accordance with the pressure of the intake pipe 20. The intake air mixed with fuel injected from the injector 30 on the downstream side of the intake pipe 20 is guided to the engine combustion chamber 32, and is ignited by the spark plug 34 within the engine combustion chamber 32. Burns and turns into exhaust gas.

The exhaust gas is released into the atmosphere via the exhaust manifold 42 and the exhaust pipe 58t. The intake temperature center t16 provided upstream of the air flow meter 14 outputs a good electrical signal to the digital electronic control circuit 56 in accordance with the intake air temperature. In addition, a cooling water temperature sensor 4 provided on the engine cylinder 46
8 outputs an electric signal according to the engine cooling water temperature to the digital electronic control circuit 56.In addition, the iron exhaust! Nifold 42
The oxygen concentration sensor 44 disposed in
Output to. Further, the crank angle sensor 40 is connected to the distributor shaft 3 driven by the carrot crankshaft.
From the 6th rotation, an electric signal tube corresponding to the engine rotational speed is output to the digital electronic control circuit 56. Also, the battery 5
The digital electronic control circuit 56, which also inputs the potential of 4 to the digital electronic control circuit s6, calculates the fuel injection amount using the outputs of the sensors and air 70-meter 14, the potential of the battery 54, etc. as calculation parameters, This result is converted into a fuel injection signal and output to the injector 30 ◎Also,
4] lK, EGRllt- from the above calculation parameters
The result is converted into an electrical signal and the EGR valve 5
Output to 2. Furthermore, in the same way, the ignition timing is calculated from the above-mentioned calculation parameters, and this result is converted into an electric signal and output to the ignition coil 38. In the digital electronic control circuit 56, during calculation processing, the ignition timing is calculated as shown in FIG. Therefore, the intake air amount tS is outputted and The intake pipe pressure signal output from the atmospheric pressure sensor 22 and the crank angle t4 (the second
Calculate the intake air amount Q2 of According to p1, calculate the average value Knt of the ratio of the first intake air amount Q1 and the second intake air amount Q2. Sometimes, it is set as a predetermined initial value〇Furthermore, the 1st 10e human air amount Ql is used as the intake air amount Q of the engine for calculating the fuel injection amount, ignition timing, exhaust gas recirculation amount, etc.〇1 On the other hand, when the first intake air amount Q1 is below the predetermined value t, the second intake air amount Q1 is increased as shown in the following equation.
2 multiplied by the above-mentioned average value Knt, Kn
(2) In the above embodiment, the magnitude relationship between the first intake air amount Q1 and the predetermined value is compared, and the difference between the low intake air amount region and the high intake air amount region is determined. However, it is of course possible to discriminate between the low intake air amount region and the high intake air amount region according to the second intake air amount Q2.

Further, in the above embodiment, in the low intake air amount region, the first intake air amount Q1 determined from air 70 - meter output
was used as is in the calculation, but this first intake air amount Q1 is used for air-fuel ratio feedback correction to feedback-correct the fuel injection amount according to the residual oxygen concentration in the exhaust gas output from the oxygen concentration sensor 44. I'll correct the learning using the coefficient.
It is also possible to obtain an accurate first intake air amount.

As explained above, the present invention covers the entire intake air amount range from the low intake air amount area to the high intake air amount area, including fuel injection amount, ignition timing, exhaust gas recirculation amount, etc. It is possible to control the engine accurately and smoothly, and also to adjust the individual differences between engines, which improves driving performance.
It has the excellent effect of reducing fuel consumption and the amount of harmful components released.

[Brief explanation of the drawing]

[Figure 1 is a sectional view, including a partial block diagram, showing an electronic control system/engine and its control device in which an embodiment of the intake air amount metering method according to the present invention is adopted; Figure 2 is a sectional view including a partial block diagram; FIG. 3 is a block diagram showing the circuit configuration of the digital electronic control circuit used in the control device, and FIG. 3 is a flowchart showing the intake air amount calculation (p-) in the digital electronic control circuit. 10... Internal combustion engine, 12... Intake passage, 14...
Air 70-meter, 18... Intake throttle valve, 20...
Intake pipe, 22... Intake pressure sensor, 30... Injector, 38... Ignition coil, 40... Crank angle control valve, 52... Exhaust gas recirculation amount control valve, 56... Digital electronic control circuit. Representative: Takaya Brass (1 person) Figure l

Claims (1)

[Claims] (1) In the low intake air amount region, the engine's intake air amount is the 1st og & human air amount determined from the output of the air flow needle installed in the V & air passage, and in the high intake air amount region, the intake throttle valve and The second
In the method for measuring the intake air amount of an electronically controlled engine in which the intake air amount is determined to be the intake air amount of the engine, the low intake air amount region is defined as the ratio of the first intake air amount to the second intake air amount. In addition to calculating and storing the average value, the first oW
It is characterized in that the amount of human air is taken as the intake air amount of the engine, and in the high intake air amount region, the second intake air amount is multiplied by the average value and the value is taken as the intake air amount of the engine. Method for measuring intake air volume for electronically controlled engines.