JPH0777440A - Intake air quantity detecting device for internal combustion engine - Google Patents

Abstract

PURPOSE:To provide an intake air quantity detecting device of an internal combustion engine capable of accurately detecting the intake air quantity. CONSTITUTION:This intake air quantity detecting device of an internal combustion engine is provided with a pressure detecting means M6 communicating the upstream side and the downstream side of throttle valves M3 provided on intake branch pipes M2 of an intake manifold M1 and detecting the intake pressure in an intake communication path M4 on the downstream side of a control valve M5 on an intake communication path M4 connected with the control valve M5, a correcting means M7 correcting the pressure value detected by the pressure detecting means M6 in response to the opening of the control valve M5, and a calculating means M8 calculating the intake air quantity based on the pressure value corrected by the correcting means M7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake air amount detecting device for an internal combustion engine, and more particularly to a throttle valve provided in each intake branch pipe of an intake manifold, and an upstream side and a downstream side of the throttle valve. The present invention relates to an intake air amount detection device for an internal combustion engine, which includes an intake communication passage that communicates with the intake communication passage and a control valve that is interposed and connected to the intake communication passage.

[0002]

2. Description of the Related Art A throttle valve provided in each intake branch pipe of an intake manifold, an intake communication passage that connects the upstream side and the downstream side of the throttle valve, and an intake communication passage connected to the intake manifold. An internal combustion engine provided with a control valve for idle speed control has been conventionally disclosed (Japanese Patent Laid-Open No. 63-154827).

In the case of detecting the intake air amount of the internal combustion engine described in the above publication, one pressure sensor for detecting the average intake pressure of all cylinders is used as the control valve in order to ensure low cost and mountability. It can be considered that the intake air amount is detected based on the pressure value detected by the pressure sensor provided in the intake communication passage on the downstream side.

[0004]

However, when the pressure sensor is provided in the intake communication passage on the downstream side of the control valve as described above, the amount of air passing through the control valve and the air passing through the throttle valve are increased. Even if the total amount is the same, the pressure value detected by the pressure sensor differs depending on the amount of air passing through the control valve, that is, the opening of the control valve.

Because the intake air on the upstream side of the control valve is at atmospheric pressure, the pressure sensor is easily affected by this atmospheric pressure due to the piping structure, and the atmospheric pressure increases as the opening of the control valve increases. This is because the influence becomes large and the pressure value detected by the pressure sensor shifts to the high pressure side (atmospheric pressure side). Therefore, if the intake air amount is calculated by using the pressure value detected by the pressure sensor as it is, there is a problem that the accurate intake air amount cannot be detected.

The present invention has been made in view of the above points. The pressure value detected by the pressure detecting means is corrected according to the opening of the control valve, and the intake air amount is corrected based on the corrected pressure value. It is an object of the present invention to provide an intake air amount detection device for an internal combustion engine, which is capable of accurately detecting the intake air amount by calculating

[0007]

FIG. 1 and FIG. 2 are diagrams showing the principle of the present invention. That is, as shown in FIG. 1, the above-described object is to provide an intake communication passage M4 that connects the upstream side and the downstream side of a throttle valve M3 provided in each intake branch pipe M2 of the intake manifold M1, and the intake communication passage M4. An intake air amount detection device for an internal combustion engine, comprising: a control valve M5 connected to a passage M4; and a control valve M5.
5, pressure detection means M6 for detecting the intake pressure in the intake communication passage M4 downstream side, and correction means M7 for correcting the pressure value detected by the pressure detection means M6 according to the opening degree of the control valve M5. A calculating means M8 for calculating the intake air amount based on the pressure value corrected by the correcting means M7.
And an intake air amount detection device for an internal combustion engine including:

Further, as shown in FIG. 2 (A), in the intake air amount detecting device for an internal combustion engine having the above-mentioned structure, the correcting means M7 has a detection value of the pressure detecting means M6 and an opening degree of the control valve M5. And a pressure value correction means for correcting the pressure value detected by the pressure detection means M6 by using the calculation result of the pressure correction value calculation means M7A. An intake air amount detecting device for an internal combustion engine including M7B is also effective.

Further, as shown in FIG. 2 (B), in the intake air amount detecting device for the internal combustion engine having the above-mentioned structure, the pressure correction value calculating means M7A is operated with respect to the opening degree formed in the control valve M5. Convergence pressure value predicting means M7 for predicting a convergence pressure value detected by the pressure detecting means M6 as a convergence value.
Aa, a convergence correction value calculation means M7Ab that calculates a pressure correction value for the convergence pressure value as a convergence correction value, and a transient correction value that gradually changes toward the convergence correction value in a predetermined step to calculate the pressure correction value. An intake air amount detection device for an internal combustion engine, which is composed of a transient correction value calculation means M7Ac that outputs a value, is also effective.

Further, as shown in FIG. 2 (A), the above object is to provide an intake air amount detecting device for an internal combustion engine having the above-mentioned structure, which is provided with an atmospheric pressure detecting means M9 for detecting the atmospheric pressure, and is provided with the pressure correction value. The calculating means M7A is the atmospheric pressure detecting means M9.
According to the intake air amount detecting device for the internal combustion engine, which calculates the pressure correction value based on the deviation between the atmospheric pressure detected by the pressure detecting means M6 and the pressure value detected by the pressure detecting means M6, and the opening degree of the control valve M5. To be achieved.

[0011]

In the intake manifold, each of the intake branch pipes is connected to the upstream side and the downstream side of a throttle valve respectively provided in the intake manifold, and the intake valve is connected to the downstream side of the control valve in the intake communication pipe. The intake pressure is detected by the pressure detecting means M6.

The pressure value detected by the pressure detecting means M6 is corrected by the correcting means M7 according to the opening degree of the control valve M5.

Then, the intake air amount is calculated by the calculating means M8 based on the pressure value corrected by the correcting means M7.

Therefore, since the pressure value detected by the pressure detecting means M6 is corrected and the intake air amount is calculated based on the corrected pressure value, the intake air amount can be detected with high accuracy. .

Further, in the second aspect of the present invention, the pressure correction value calculation means M7A constituting the correction means M7 is
The pressure correction value is calculated based on the opening degree of the control valve M5 and the pressure downstream of the control valve M5.

In this case, the change in the internal pressure of the intake communication passage M4 due to the opening of the control valve M5 is
5 corresponds to the opening degree of the control valve M5 and the pressure difference acting between the upstream side and the downstream side of the control valve M5. Therefore, the pressure correction value is set in the intake communication passage M4 accompanying the opening of the control valve M5. The pressure change of is accurately displayed instead. Therefore, in the pressure correction means M7B that corrects the detection value of the pressure detection means M6 based on the pressure correction value, the correction can be realized accurately and according to the actual situation.

In the third aspect of the present invention, the convergent pressure value judging means M7Aa constituting the pressure correction value calculating means M7A is set to a final value when the opening of the control valve M5 changes. Specifically, the pressure value formed in the intake communication passage M4 is predicted.

Then, the convergence correction value calculation means M7Ab
Calculates a convergence correction value corresponding to the predicted convergence pressure value, and the transient correction value calculation means M7Ac calculates a value that gradually changes toward the convergence correction value as a transient correction value, and at the same time, calculates the value. Is output as the pressure correction value.

By the way, after the opening of the control valve M5 suddenly changes and before the detected value of the pressure detecting means M6 follows the change, the opening of the control valve M5 and the pressure detecting means are temporarily changed. The correlation with the detected value of M6 is broken.
Therefore, when the pressure correction value is calculated by capturing the instantaneous value, a large error is superimposed on the pressure correction value.

On the other hand, the transient correction value calculation means M7
The calculation result of Ac is always the convergent pressure value prediction means M7A.
The transient correction value is calculated based on the convergent pressure value of the intake communication passage M4 predicted by a. Therefore, the error due to the responsiveness of the pressure detecting means M6 does not overlap, and the pressure correction value according to the actual situation is calculated during the transition.

Further, in the fourth aspect of the present invention, the pressure correction value calculation means M7A is the atmospheric pressure detection means M9.
The pressure correction value is calculated based on the deviation between the detection value of 1 and the detection value of the pressure detecting means M6. In this case, even if the atmospheric pressure which is the upstream pressure of the control valve M5 fluctuates, the fluctuation is reflected in the calculation of the pressure correction value, and the calculation accuracy of the pressure correction value is improved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 3 is a schematic diagram showing an outline of the overall configuration of a four-cylinder internal combustion engine equipped with the intake air amount detection device according to the present invention. The internal combustion engine shown in FIG. It is a multiple throttle type internal combustion engine used.

As shown in FIG. 3, the intake manifold 2 of the internal combustion engine 1 of this embodiment has four intake branch pipes 3. An air cleaner 21 is provided on the upstream side of the intake manifold 2, and a throttle valve 4 is provided on each of the intake branch pipes 3. The throttle valve 4 is
A throttle opening sensor (not shown) for detecting the opening of is attached.

In FIG. 3, reference numeral 5 denotes an idle adjustment passage corresponding to the intake communication passage M4. The idle adjustment passage 5 has a collecting pipe portion 51 and four branch pipe portions 52 branched from the collecting pipe portion 51. And have. In the collecting pipe portion 51, one end of the collecting pipe portion 51 communicates with the intake manifold 2, and each branch pipe portion 52 communicates with each intake branch pipe 3 downstream of the throttle valve 4. .

Further, in the collecting pipe portion 51 of the idle adjusting passage 5, an idle speed control valve (I) corresponding to the control valve composed of, for example, a solenoid valve is provided.
(SCV) 6 is interposed and connected, and the collecting pipe section 51 on the downstream side of this ISCV 6 is provided with a pressure sensor 7 corresponding to the above-mentioned pressure detecting means M6.

The throttle opening sensor, the ISCV 6 and the pressure sensor 7, which are not shown, are connected to an electronic control unit (ECU) 8, and the ISCV 6 is an ECU.
It is configured to be opened and closed by a control signal from 8.

The intake branch pipes 3 are respectively provided with intake valves 9
1 is connected to the combustion chamber 92 of each cylinder, and each intake branch pipe 3 is provided with a fuel injection valve 93 corresponding to each cylinder. And the combustion chamber 9
2 is a three-way catalyst 96 via an exhaust valve 94, an exhaust pipe 95, etc.
Is in communication with.

The ECU 8 is, for example, a microcomputer, is a control device for realizing the above-mentioned correction means M7 and calculation means M8 by software processing, and has a known hardware configuration as shown in FIG. In FIG. 4, the same components as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 4, a microcomputer 8 includes a central processing unit (CPU) 80, a read only memory (ROM) 81 storing a processing program, and a random access memory (RAM) used as a work area.
82, a back-up RAM 83 that holds data even after the internal combustion engine is stopped, an input interface circuit 84 with a multiplexer, an A / D converter 86, an input / output circuit 85, etc., which are connected via a bus 87.

The input interface circuit 84 sequentially switches the detection signals from the ISCV opening sensor and the throttle opening sensor (not shown), the pressure detection signal from the pressure sensor 7 and the like into a serial signal which is time-sequentially combined. Is supplied to a single A / D converter 86 for analog-to-digital conversion and then sequentially sent to the bus 87.

The input / output interface circuit 85 receives a detection signal from a throttle opening sensor (not shown) and inputs it to the CPU 80 via the bus 87. On the other hand, each signal input from the bus 87 receives the ISCV6 and the fuel injection valve. 9
3 and the like to selectively send them to control them.

C of the microcomputer 8 having the above configuration
The PU 80 executes the processing of the flowchart described below according to the program stored in the ROM 81. FIG. 5 is a flow chart for explaining the operation of the embodiment of the main part of the present invention.

In FIG. 5, first, in step 402, the current pressure value detected by the pressure sensor 7 is read, and this pressure value is stored as the measured pressure value pm. Next, at step 404, it is determined whether the ISCV6 is open, and I
If it is determined that SCV6 is closed, step 4
At 06, the measured pressure value pm is stored as the true pressure value PM,
In step 420, the intake air amount is calculated based on this true pressure value PM, and the process ends.

On the other hand, if it is determined in step 404 that ISCV6 is open, then in step 408 ISCV6 is opened.
The opening isc of 6 is read. And step 410
Then, the measured pressure value pm read in step 402 above
And R from the isc read in step 408 in advance.
The correction constant KPM is read from the KPM map shown in FIG. 5 stored in the OM 81.

Here, the KPM map will be specifically described. As shown in FIG. 7 (A), when the intake air amount supplied to the internal combustion engine 1 is constant, that is, when the average pressure in the intake branch pipe 3 is constant, the throttle valve shown in FIG. The smaller the opening of the valve 3, the larger isc.
Then, the measured pressure value p detected by the pressure sensor 7
As shown in FIG. 7C, m becomes closer to the atmospheric pressure as the opening degree isc of the ISCV 6 increases.

That is, the measured pressure value p by the pressure sensor 7
An error corresponding to isc with respect to the true pressure in the intake branch pipe 3 is superimposed on m, and the inside of the intake branch pipe 3 is grasped as a substitute characteristic value of the intake air amount supplied to the internal combustion engine 1. In order to detect the true pressure value of pm, it is necessary to correct pm according to isc.

Therefore, in this embodiment, ISCV6
Fig. 7 shows the amount of deviation of the intake pressure that occurs according to the opening degree isc of
As shown in (C), the pressure correction value KPM is defined, and the KPM is used to correct the pressure value pm actually measured by the pressure sensor 7.

Here, in FIG. 6 described above, in the internal combustion engine 1, KP is used with the intake air amount, engine speed, etc. as parameters.
It is a map showing the relationship between isc and KPM by measuring M in advance and arranging the results for each pm.

Incidentally, in FIG. 6, pm = 681 mmHg, 447 mm
This is an example of Hg and 134 mmHg. In this case, the larger isc is, the smaller KPM is.
Is larger, the pressure sensor 7 has a pressure on the upstream side of the ISCV6,
This is because it is considered that the pressure value of the pressure sensor 7 is greatly affected by the atmospheric pressure, and as a result, the pressure value of the pressure sensor 7 largely deviates to the high pressure value (atmospheric pressure side), and the intake pressure deviation amount increases.

The smaller the pm, the smaller the KPM is that the smaller the Pm, the pressure difference between the upstream and the downstream of the ISCV 6, that is, the pressure between the atmospheric pressure and the true pressure in the intake branch pipe 3. It is estimated that the difference is large, and therefore ISCV6
This is because the fact that it can be predicted that the opening of the valve has a large effect on pm is considered.

Returning to the explanation of FIG. 5 again, step 412
Then, the measured pressure value pm read in step 402 above
And the correction constant KPM read in step 410 are multiplied, and the result is stored as the true pressure value PM.

Then, in step 420, the intake air amount is calculated based on the true pressure value PM obtained in step 412, and the process ends.

In the present embodiment, the above step 40
8 to step 412 correspond to the correction means M7 described above, more specifically, the steps 408 and 410 correspond to the pressure correction value calculation means M7A described above, and the step 412 corresponds to the pressure value correction means M7B described above. The above step 420 corresponds to the calculating means M8 described above.

Further, the pressure sensor 7 and the above step 4
02 to step 412 and step 420 constitute the intake air amount detection device according to the present invention.

According to the above-described embodiment, the pressure value detected by the pressure sensor 7 is corrected according to isc, and the intake air amount is calculated based on the corrected pressure value. The amount of air can be detected accurately.

Further, according to the present embodiment, since the idle adjusting passage 5 and the passage for the pressure sensor 7 can be shared, the pipe can be simplified.

The application of the present invention is not limited to the above-mentioned embodiment.
It is not limited to application to a cylinder type internal combustion engine.

By the way, when isc suddenly changes as shown in FIG. 8 (A) (time t ₁ in FIG. 8), its influence is as shown in FIG.
As shown in (B), after a proper delay time, the pressure sensor 7
Up to. This is because there is a distribution time due to the distance from the ISCV 6 to the pressure sensor 7.

Therefore, for example, isc as shown in FIG.
In the transitional period (the period immediately after time t _{1 in} FIG. 8), the measured pressure value pm is low and isc is large.

In this case, as shown in the above-mentioned embodiment, when the map shown in FIG. 6 is simply searched by using isc and pm to calculate KPM, it is immediately after the change of isc and in practice pm is almost Although it is equal to the true pressure value PM, the pressure correction value KPM is temporarily set to an excessively small value as shown in FIG. 8C. If KPM becomes an abnormal value in this way, a large error will occur in the calculation accuracy of the intake air amount.

On the other hand, when the opening degree of the ISCV 6 changes as shown at time t ₁ in FIG. 8, the converged pressure value of pm at time t ₂ after the elapse of a predetermined time is predicted, and the converged pressure value in the transition period If the KPM is gradually changed toward the pressure correction value Kd with respect to the pressure value, it is possible to calculate the pressure correction value according to the actual situation of the true pressure fluctuation in the intake branch pipe 3.

FIG. 9 shows the ECU 8 for realizing such a function.
5 is a flowchart of a second example of an intake air amount detection routine executed by the. In the figure, the same processing steps as those in the routine shown in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted or simplified.

In the routine shown in FIG. 9, after reading the pressure value pm from the pressure sensor 7 in step 402,
When it is determined in step 404 that the ISCV6 is open, the routine proceeds to step 500, where it is determined whether isc has changed from the previous processing.

Here, if it is determined that isc has not changed, it is not necessary to consider the transient characteristic in the calculation of the pressure correction value KPM, so that steps 408 and 410 are performed as in the embodiment shown in FIG. , 412, and 420 are sequentially executed, and the process ends.

On the other hand, if it is determined in step 500 that isc has changed, the routine proceeds to step 502, where TAisc = isc * K is calculated in order to convert the changed amount of isc into the changed amount of the throttle valve 4. To do.

Then, in step 504, as shown in FIG.
As shown in, the map set in advance as a function of the throttle valve opening TA is referred to, and pm (= p
The converged pressure value pd in the state after ISCV6 change is calculated from a) and the calculated TAisc.

The ECU 8 stores a plurality of maps representing the relationship between TA and pm with the engine speed NE as a parameter, and when executing the above step 504, a map is appropriately created based on the engine speed NE. We are making a selection.

When the convergent pressure value pd is calculated in this way, the routine proceeds to step 506, where the pressure correction values Ka and Kd for pa and pd are read from the map shown in FIG.
This is for setting the start value and target value of the transient correction value after the change of ICSV6.

The following step 508 is a step of changing the Ka obtained as described above by a predetermined width.
When the opening degree isc of 6 is increasing, Ka-α is performed, and when the opening degree isc is decreasing, Ka + β is changed to a new Ka.

In this case, α and β are change widths set to realize the gradual change of KPM shown in time t _{1 to} t ₂ in FIG. 8 (C), and in the case of increase of isc, pm and Considering that the amount of intake pressure deviation from PM gradually increases, while isc
In the case of decrease, considering that the intake pressure deviation amount between pm and PM is gradually decreased, α is subtracted from KPM or β is added to KPM.

It should be noted that α and β must be set in such a range that the KPM is gradually changed so as to match the manner in which pm changes toward pd after the change in opening of ISCV6. In the embodiment, as shown in FIG. 11, α (the relationship shown by the solid line in the figure) and β (the relationship shown by the broken line in the figure) are set as the functions of NE.

In this case, the higher the NE, the larger α and β are because the higher the NE, the larger the number of intake stroke executions per unit time. Therefore, as shown in FIGS. 12 (A) and 12 (B). This is because the convergence of pm after ISCV6 change is good. Further, β is set to be smaller than α in consideration of the fact that the pm decompression is performed more gently than the pm pressure increasing as shown in FIG. 12 (B).

When the transient correction value Ka is obtained in this way,
In step 510, the calculation PM = pm * Ka is performed to calculate the true pressure PM in the intake branch pipe 3 during the transition period. Then, the process proceeds to step 512 which performs substantially the same process as step 420, calculates the intake air amount based on the obtained PM, and then proceeds to step 514.

In step 514, the above step 508 is executed.
This is a step of determining whether the transient correction value Ka set in step 1 has reached the convergent pressure value Kd. In this case, K
If a = Kd does not hold, the above step 508 is performed again.
The subsequent processing is executed, and the current processing is ended as soon as Ka = Kd is established.

As described above, when the ECU 8 executes the above process, the opening degree isc of the ISCV 6 is in a stable state,
When the relationship between c, pm, and PM satisfies a predetermined relationship known for the internal combustion engine 1, pm correction is performed with an appropriate pressure correction value KPM according to the isc. On the other hand, isc
When the relationship between isc, pm and PM does not satisfy the known relationship, the transient correction value Ka that gradually changes with the convergence correction value Kd set for the convergence pressure value pd satisfying the relationship as the target value. Corrects pm.

Therefore, according to the present embodiment, even after the change of ISCV6, even if the pm changes transiently, it is possible to realize an appropriate pm correction adapted to the change, and the internal combustion engine It is possible to realize highly accurate intake air amount detection irrespective of the change in the operating state of No. 1.

In the above embodiment, step 504 corresponds to the convergent pressure value predicting means M7Aa, and step 506 corresponds to the convergent correction value calculating means M7Ab.
And the step 508 corresponds to the transient correction value computing means M7Ac described above.

By the way, in the above embodiment, the pressure correction is executed by approximating the differential pressure between the upstream and the downstream of the ISCV6 as a function of pm only. The pressure correction accuracy may be deteriorated due to a certain atmospheric pressure fluctuation.

In this case, an atmospheric pressure sensor is provided separately from the pressure sensor 7, and the atmospheric pressure PA and the actually measured pressure value p of the pressure sensor 7 are set.
If the pressure difference PB with respect to m is obtained and the pressure correction is performed based on this PB, the pressure correction accuracy can be prevented from being influenced by the atmospheric pressure PA fluctuation.

13 and 14 show an example of a flowchart of a third embodiment of the intake air amount detection routine executed by the ECU 8 to realize such a function, and an example of a map used for executing the routine. Is. Incidentally, FIG.
Among the steps, the same steps as those in the routine shown in FIG. 5 are designated by the same reference numerals and the description thereof will be omitted.

That is, in the routine shown in FIG. 13, when it is determined in step 404 that the ISCV valve is opened,
After execution of step 408, the atmospheric pressure sensor detects the atmospheric pressure PA.
Execute step 600 to read, then read P
It is characterized in that step 602 of calculating the differential pressure PB between A and pm is executed, and further step 604 of reading out the pressure correction value KPM based on PB is executed.

Here, the ECU 8 uses the KP shown in FIG.
As shown in FIG. 14, the M map is previously set to PB (= PA-p
m) is converted into a KPM map using the parameter as a parameter and stored, and in step 604, the KPM considering the influence of atmospheric pressure is calculated by referring to the map of FIG. 14 for isc and PB. be able to. Then, by performing steps 412 and 420 thereafter, highly accurate intake air amount detection that is not affected by atmospheric pressure fluctuation can be realized.

In this embodiment, the above step 6
00 to the atmospheric pressure detecting means M9 described above,
02, 604 to the pressure correction value calculation means M7A described above,
Further, the above step 412 is the pressure value correction means M7 described above.
It corresponds to B.

[0074]

As described above, according to the first aspect of the present invention, the pressure detection for detecting the intake pressure in the intake communication passage downstream of the control valve of the intake communication passage to which the control valve is interposed and connected. Since the pressure value detected by the means is corrected according to the opening degree of the control valve and the intake air amount is calculated based on the corrected pressure value, the intake air amount can be accurately detected. .

Further, according to the second aspect of the invention, the pressure fluctuation in the intake communication passage due to the opening of the control valve can be accurately displayed as a substitute by the pressure correction value, and based on this value. Since the correction is performed, the intake air amount can be detected with higher accuracy.

Further, according to the third aspect of the invention, the opening of the control valve suddenly changes, and as a result, the opening of the control valve, the detected value of the pressure detecting means M6 and the true pressure in the intake communication passage are changed. Even if the relationship temporarily becomes abnormal, the abnormal state is not reflected in the calculation result of the pressure correction value calculation means, and it is possible to always realize highly accurate intake air amount detection according to the actual situation.

According to the fourth aspect of the invention, when the atmospheric pressure, which is the upstream pressure of the control valve, fluctuates, the fluctuation is reflected and is always based on the pressure difference between the upstream side and the downstream side of the control valve. The calculation of the pressure correction value is realized. Therefore, the intake air amount detection device for an internal combustion engine according to the present invention can detect the intake air amount with high accuracy without being affected by atmospheric pressure fluctuations.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram of a first aspect of the present invention.

FIG. 2 is a principle configuration diagram of second to fourth aspects of the present invention.

FIG. 3 is a schematic diagram showing an outline of the overall configuration of a four-cylinder internal combustion engine equipped with the intake air amount detection device according to the present invention.

FIG. 4 is a diagram showing a hardware configuration of a microcomputer forming the ECU in FIG.

FIG. 5 is a flowchart of an example of an intake air amount detection routine executed by the ECU of the present embodiment.

FIG. 6 is a diagram showing an example of a KPM map.

FIG. 7 is a characteristic diagram showing the relationship between the opening of ISCV and the amount of deviation of intake pressure.

FIG. 8 is a time chart for explaining a transitional situation after a change in ISCV opening.

FIG. 9 is a flowchart of another example of an intake air amount detection routine executed by the ECU of this embodiment.

FIG. 10 is a diagram showing a relationship between a throttle opening TA and a measured pressure value pm.

FIG. 11 is an example of a map used for calculating a transient correction value.

FIG. 12 is a diagram for explaining the followability of pm with respect to changes in the opening of ISCV.

FIG. 13 is a flowchart of another example of an intake air amount detection routine executed by the ECU of this embodiment.

FIG. 14 is a diagram showing another example of a KPM map.

[Explanation of symbols] [Explanation of symbols]

 M1,2 Intake manifold M2,3 Intake branch pipe M3,4 Throttle valve M4 Intake communication passage M5 Control valve M6 Pressure detection means M7 correction means M7A Pressure correction value calculation means M7Aa Convergence pressure value prediction means M7Ab Convergence correction value calculation means M7Ac Transient correction value calculation means M7B Pressure correction value calculation means M8 Calculation means 1 Internal combustion engine 5 Idle adjust passage 6 Idle speed control valve (ISCV) 7 Pressure sensor 8 ECU (microcomputer) 51 Collecting pipe part 52 Branch pipe part

Claims (4)

[Claims] 1. A throttle valve provided in each intake branch pipe of an intake manifold, an intake communication passage that communicates an upstream side and a downstream side of the throttle valve, and an intake communication passage connected to the intake communication passage. An intake air amount detection device for an internal combustion engine for detecting an intake air amount of an internal combustion engine, comprising: a control valve; pressure detection means for detecting an intake pressure in an intake communication passage downstream of the control valve; Compensating means for compensating the pressure value detected by the pressure detecting means according to the opening degree of the control valve, and computing means for computing the intake air amount based on the pressure value corrected by the compensating means. An intake air amount detection device for an internal combustion engine, comprising: 2. The intake air amount detection device for an internal combustion engine according to claim 1, wherein the correction means calculates a pressure correction value based on a detection value of the pressure detection means and an opening degree of the control valve. An intake air amount of an internal combustion engine, comprising: a correction value calculation means and a pressure value correction means for correcting a pressure value detected by the pressure detection means by using a calculation result of the pressure correction value calculation means. Detection device. 3. The intake air amount detection device for an internal combustion engine according to claim 2, wherein the pressure correction value calculation means detects the pressure correction value as a convergence value with respect to an opening formed in the control valve. Convergence pressure value predicting means for predicting a convergence pressure value, convergence correction value calculating means for calculating a pressure correction value for the convergence pressure value as a convergence correction value, and a transient that gradually changes toward the convergence correction value in predetermined steps. An intake air amount detection device for an internal combustion engine, comprising: a transient correction value calculation means for calculating a correction value and outputting it as the pressure correction value. 4. The intake air amount detecting device for an internal combustion engine according to claim 2, further comprising atmospheric pressure detecting means for detecting atmospheric pressure, wherein the pressure correction value calculating means is detected by the atmospheric pressure detecting means. An intake air amount detection device for an internal combustion engine, wherein the pressure correction value is calculated based on a deviation between an atmospheric pressure and a pressure value detected by the pressure detection means, and an opening degree of the control valve.