JPH02185636A - Device for controlling fuel feeding of internal combustion engine - Google Patents

Abstract

PURPOSE:To get rid of delay in response caused by smoothing treatment by correctingly setting the smoothing treating value of an engine load parameter which is set based on an intake air condition quantity by an engine load parameter based on an intake air system opening area and engine speed. CONSTITUTION:An engine load parameter which is set based on an intake air condition quantity by a detecting means 1 is smoothed by a treating means 4 to remove the effect of intake air pulsation. A setting means 5 sets an engine load parameter based on an intake air system opening area and engine speed by detecting means 2, 3, thereby correcting the parameter which is smoothing treated by a correcting means 6 to set a fuel feeding quantity by a setting means 7. Also, when the correcting means 6 includes an equal characteristic smoothing treating means 9 and a correcting value setting means 10, the opening area dependent parameter is smoothing treated by a nearly equivalent smoothing characteristic and corrected by the engine load parameter and given to the correcting means 6. Thereby, the delay in response can be prevented while avoiding the effect of pulsation.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a fuel supply control device for an internal combustion engine, and more specifically, it detects state quantities of engine intake air such as intake air flow rate and intake pressure, and calculates the detected value. The present invention relates to a fuel supply control device configured to control a fuel supply amount based on.

<Prior art> Conventionally, internal combustion engine fuel supply control devices detect state quantities of engine intake air such as intake air flow rate and intake pressure, set a basic fuel supply amount based on the state quantities, and set the basic fuel supply amount based on the state quantities. Electronically controlled fuel injection devices configured to drive and control fuel injection valves based on a set basic fuel supply amount are widely used (see Japanese Patent Application Laid-Open No. 59-49334, etc.).

By the way, in an internal combustion engine, pressure pulsations occur in the intake passage due to the influence of intake and exhaust, so the detection signal of a sensor installed in the intake passage that detects the intake air flow rate and intake pressure does not correspond to the pressure pulsation. If you pick up and control the fuel supply amount according to the pulsation that is unrelated to the required fuel amount,
There was a problem in that it caused fluctuations in the air-fuel ratio. For this reason, conventionally, the pulsation is generally smoothed by taking a weighted average of the intake air flow rate and intake pressure detected by the sensor.

<Problems to be Solved by the Invention> However, when trying to smooth out pulsations by weighted averaging of detected values of intake air flow rate and intake pressure as described above,
If the degree of smoothing by weighted average calculation is set to a large value in an attempt to suppress the air-fuel ratio fluctuations affected by intake pulsation to a level that does not cause problems, this will cause problems during transient operation when the intake air flow rate and intake pressure corresponding to the required fuel amount of the engine increase or decrease. A problem arises in that the responsiveness of the weighted average calculated intake air flow rate and intake pressure deteriorates, making it impossible to obtain good fuel control performance during transient operation.

Therefore, it is necessary to determine from the throttle valve opening degree and engine speed whether the operating state is a steady state in which pulsation avoidance is required rather than responsiveness, or whether it is a transient operating state in which detection responsiveness is required more than pulsation avoidance. , weighting in the weighted average calculation is changed based on the stationary/transient discrimination of the engine. However, it is difficult to accurately distinguish between steady and transient operation of the engine in accordance with the above requirements, and for example, as shown in Figure 7, steady operation may be determined in the middle of slow acceleration operation. In this way, when steady operation is determined during acceleration, a weighted average calculation that emphasizes responsiveness should be performed, but a weighted average calculation that sacrifices responsiveness can better avoid the pulsation effect. This occurs during acceleration, causing a problem in that fuel controllability during transient operation varies.

The present invention has been made in view of the above problems, and is a fuel supply control device for an internal combustion engine that is capable of ensuring control responsiveness during transient operation while performing smoothing processing to avoid pressure pulsation effects. The purpose is to provide

<Means for Solving the Problem> Therefore, in the present invention, as shown in FIG. Smoothing processing means for smoothing a state quantity of intake air or an engine load parameter set based on this state quantity, an opening area detection means for detecting an opening area of an engine intake system that is variably controlled, and a detection means for detecting an engine rotation speed. an engine rotation speed detection means; an engine load parameter setting means for setting an engine load parameter based on the opening area and the engine rotation speed detected by each of the detection means; and an engine load parameter setting means for setting an engine load parameter based on the engine rotation speed and the opening area detected by each of the detection means; smoothing parameter correction means for correcting and setting the parameters smoothed by the smoothing processing means based on the parameters and smoothing characteristic values in the smoothing processing means; and based on the parameters corrected and set by the smoothing processing parameter correction means. a fuel supply amount setting means for setting the fuel supply amount; and a fuel supply control means for controlling the fuel supply to the engine based on the fuel supply amount set by the fuel supply amount setting means. The supply control device can now be configured.

Further, as shown by the dotted line in FIG. 1, the smoothing parameter correction means smoothes the engine load parameter set by the engine load parameter setting means using the smoothing characteristics of the smoothing processing means and the road gap, etc. a smoothing means, and a parameter smoothed by the smoothing means based on the difference between the engine load parameter smoothed by the characteristic smoothing means and the engine load parameter set by the engine load parameter setting means. It is preferable to include a correction value setting means for setting a correction value for setting the correction.

Further, the smoothing process in the smoothing processing means is performed by calculating a weighted average of the state quantity of the intake air detected by the intake air state quantity detection means or the engine load parameter set based on this state quantity, and The smoothing process in the same characteristic smoothing process unit may be configured to be performed by calculating a weighted average of the engine load parameters using the same weight as the weighted average calculation.

Further, the smoothing processing means is constituted by a filter circuit that smoothes and outputs the detection signal from the intake air state quantity detection means, and the smoothing processing in the characteristic smoothing processing means is performed using a time constant of the filter circuit. The calculation may be performed by calculating a weighted average of the engine load parameters using a weight corresponding to the weight.

<Operation> According to this configuration, the intake air state quantity detection means detects the intake air state quantities such as the intake air flow rate and intake pressure of the engine, and detects the intake air state quantity based on the detected intake air state quantity or this state quantity. Set engine load parameters (for example, basic fuel supply amount according to intake air amount or proportional value of the basic fuel supply amount)
is smoothed by the smoothing means. Therefore, the parameters after being smoothed by the smoothing processing means have smoother change characteristics than the detected state quantity of intake air,
As a result, even if intake pulsation is detected by the intake air state at detection means, it is possible to prevent its influence from appearing on the parameters after being processed by the smoothing processing means.

Further, the opening area detection means detects the opening area of the engine intake system which is variably controlled via the throttle valve opening degree, etc., and the engine rotational speed detection means detects the engine rotational speed. The engine load parameter setting means sets engine load parameters such as the basic fuel supply amount, volumetric efficiency, and intake air amount based on the opening area and engine rotational speed respectively detected by the detection means.

The smoothing processing parameter correction means uses the engine load parameter set from the opening area and the engine rotation speed as described above,
Based on the smoothing characteristic value in the smoothing process performed by the smoothing process unit, the parameters smoothed by the smoothing process unit are corrected and set.

After the smoothing process as described above, the parameters corrected based on the engine load parameters set without using the state quantity of the intake air and the characteristic values during the smoothing process are used in the fuel supply amount setting means to Used to set the amount. Once the fuel supply amount is set, the fuel supply control means controls the fuel supply to the engine based on this fuel supply amount.

That is, in the fuel supply device according to the present invention, the fuel supply amount is set and controlled based on the state quantity of the intake air, but the state quantity of the intake air detected by the intake air state quantity detection means is directly used. Instead of setting the final fuel supply amount based on the state quantity, first, the state quantity of the intake air or the engine load parameter set based on this state quantity (hereinafter referred to as the state quantity dependent parameter) is smoothed. On the other hand, the engine load parameter (hereinafter referred to as the opening area dependent parameter) is set based on the opening area and rotational speed of the intake system without using the state quantity of the intake air, and the smoothed state quantity dependent parameter is Correction is performed based on the aperture area dependent parameter that is not smoothed and responsiveness is ensured, and a smoothing characteristic value in the smoothing process of the state quantity dependent parameter, so that the response delay due to the smoothing process is improved by the correction. do.

Then, the fuel supply amount is set based on the state quantity dependent parameter after the response delay due to smoothing processing has been improved.

Further, when the smoothing processing parameter correction means includes a smoothing processing means with the same characteristics and a correction value setting means,
The opening area dependent parameter is smoothed by the smoothing processing means with the same characteristics as when the state quantity dependent parameter is smoothed. Further, the correction value setting means sets a correction value for the state quantity dependent parameter after the smoothing process based on the difference between the opening area dependent parameter smoothed as described above and the opening area dependent parameter before the smoothing process. , the state quantity dependent parameters after the smoothing process are corrected and set based on this correction value.

In other words, the aperture area dependent parameter with guaranteed responsiveness is
By performing smoothing processing in the same manner as the state quantity dependent parameters, a response delay similar to that of the state quantity dependent parameters after smoothing is generated, and the difference between the opening area dependent parameters after smoothing and before smoothing is state quantity dependent. It is assumed that this is a response delay due to parameter smoothing processing, and the smoothed state quantity dependent parameter is corrected to a characteristic corresponding to a true state quantity change.

Here, the smoothing process in the smoothing processing means for smoothing the state quantity dependent parameters may be performed by calculating a weighted average of the state quantity dependent parameters. The smoothing process by the smoothing process means is also weighted and averaged with the same weighting as when the state quantity dependent parameters are weighted and averaged.

Further, the smoothing process by the smoothing process means is not limited to software such as the above-mentioned weighted average calculation, but is implemented by a filter circuit that smoothes and outputs the detection signal from the intake air state quantity detecting means, that is, hardware. In this case, the smoothing process in the characteristic smoothing means may be performed by calculating a weighted average of the aperture area dependent parameters with a weight corresponding to the time constant of the filter circuit.

<Example> The present invention will be explained in detail below.

In FIG. 2 showing the system configuration of one embodiment, an internal combustion engine 1 includes an air cleaner 2. Air is taken in through the intake duct 3, the throttle chamber 4, and the intake manifold 5. The air cleaner 2 has an intake air (atmospheric) temperature TA (
An intake air temperature sensor 6 is provided to detect 'C). The throttle chamber 4 is provided with a throttle valve 7 that operates in conjunction with an accelerator pedal (not shown) to control the intake air flow rate Q. The throttle valve 7 has its opening degree T.
A throttle sensor 8 including an idle switch 8A that is turned on at its fully closed position (idle position) is attached along with a potentimeter as an opening area detection means for detecting VO.

The intake manifold 5 downstream of the throttle valve 7 is provided with an intake pressure sensor 9 as an intake air state quantity detection means for detecting intake pressure ('@inlet negative pressure) PB as a state quantity of the intake air, and is also provided with an intake pressure sensor 9 as an intake air state quantity detection means. 10 electromagnetic fuel injection valves for each
is provided. The fuel injection valve 10 includes a My, which will be described later.
Control unit 11 with built-in black computer
For example, the valve is driven to open by an injection pulse signal output in synchronization with the ignition timing, and fuel is injected into the intake manifold 5, which is pressure-fed from a fuel pump (not shown) and controlled to a predetermined pressure by a pressure regulator.

That is, the amount of fuel supplied by the fuel injection valve 10 is controlled by the valve opening driving time of the fuel injection valve 10.

Furthermore, a water temperature sensor 12 for detecting the cooling water temperature Tw in the cooling jacket of the engine 1 is provided, and the exhaust passage 1
An oxygen sensor l4 is provided within the engine 3 to detect the air-fuel ratio of the intake air-fuel mixture by detecting the oxygen concentration in the exhaust gas.

The control unit 11 counts the crank unit angle signal PO3 output from the crank angle sensor 15 as an engine rotation speed detection means in synchronization with the engine rotation for a part of the time or at a predetermined crank angle position (for example, ATDC 90°).
) The engine rotation speed N
Detect.

In addition, the transmission attached to the engine l is provided with a vehicle speed sensor 16 for detecting vehicle speed, a neutral sensor 17 for detecting a neutral position, and the like, and these signals are input to the control unit 11.

Additionally, an auxiliary air passage 18 bypassing the throttle valve 7
is provided with an electromagnetic idle control valve 19 that controls the idle rotation speed via the amount of auxiliary air.

The control unit 11 calculates the fuel injection amount Ti (fuel supply amount) based on the various detection signals detected as described above, and also calculates the fuel injection amount Ti (fuel supply amount) based on the injection pulse signal having a pulse width corresponding to the set fuel injection amount Ti. Fuel injection valve 1
0 to open drive control. Furthermore, the control unit 11
is idle switch 8A and neutral sensor 17
Idle control valve 1 during idle operation detected based on
By controlling the opening degree of 9, the idle rotation speed is feedback-controlled to the target idle rotation speed.

Next, various calculation processes for fuel supply control performed by the control unit 11 will be explained according to the routines shown in the flowcharts of FIGS. 3 and 4, respectively.

In this embodiment, smoothing processing means 1 includes engine load parameter setting means and smoothing processing parameter correction means.

The functions of the fuel supply amount setting means, the simultaneous smoothing processing means, and the correction value setting means are provided in the form of software as shown in the flowcharts of FIGS. 3 and 4.

Further, the fuel supply control means is constituted by a fuel injection valve 10 and a control unit 11.

The routine shown in the flowchart of FIG. 3 is executed every predetermined minute period of about 10 m5, and first, in step l (indicated as Sl in the figure, the same applies hereinafter),
Throttle valve 7 detected by throttle sensor 8
Enter the opening TVO.

In the next step 2, the value obtained by multiplying the intake pressure PB detected by the intake pressure sensor 9 by the engine rotation speed N calculated based on the output signal from the crank angle sensor 15 (=
PBXN), the basic volumetric efficiency QHφ is predicted and set based on the opening area A and the engine rotational speed N, which will be described later.
2 is searched from the map to find the correction coefficient for correcting it to follow the true engine load change.

In step 3, the opening area A of the engine 1 intake system is searched from the map and determined based on the throttle valve opening degree TVO input in step 1. Note that when determining the opening area A, if an auxiliary air passage 18 is provided that bypasses the throttle valve 7 as in this embodiment, the drive to the idle control valve 19 that controls the opening degree of the auxiliary air passage 18 is determined. The opening area of the intake system is controlled by the throttle valve 7 by determining the opening area of the auxiliary air passage 18 via a signal, etc., and adding this opening area to the opening area determined based on the throttle valve opening degree TVO. It is desirable to be able to ask for more than just things.

In the next step 4, the basic volumetric efficiency QHφ (engine load parameter) is searched and determined from the map based on the value (-Alx) obtained by dividing the opening area A obtained in step 3 by the engine rotational speed N. The basic volumetric efficiency QHφ is a value obtained by dividing the volume of intake fresh air by the stroke volume, and corresponds to the intake air amount.
After determining φ by experiment, control unit 1
Alx in the ROM of the microcomputer built into 1.
The settings can be stored as a map corresponding to the map.

In step 5, the basic volumetric efficiency QH obtained in step 4 is
φ, 2 for the correction coefficient obtained in step 2, and the volumetric efficiency Q obtained in step 5 during the previous execution of this routine.
The volumetric efficiency QCYL that follows the true engine load change is calculated using QCYLO which is CYL according to the following formula.

QCYL+ Q HφXK2+QCYLOX (1- to 2) The basic volumetric efficiency QHφ found by searching from the map based on the A/N in step 4 corresponds to approximately the true intake air amount during steady operation of the engine l. ,
During transient operation, there is a delay in the response of the actual intake air amount, so the previous value QCYLO and the latest basic volumetric efficiency QHφ are weighted by a correction factor of 2, and the change in the basic volumetric efficiency QHφ is calculated by searching from the map. Volumetric efficiency QC that slows down and follows the actual engine load change (intake air amount change)
This is how YL is set.

In the next step 6, the basic fuel injection amount (opening area dependent parameter) αN-Tp is calculated based on the opening area A and the engine rotational speed N according to the following equation.

a N -T p←KcONA X QCYL X K
TA2 Here, KCONA is a constant, QCYL is the volumetric efficiency obtained in step 5 above, and KTA2 is searched from the map based on the intake air temperature TA detected by the intake air temperature sensor 6 in the background job (BGJ") described later. This is the intake air temperature correction coefficient to be set.

In the next step 7, a weighted average value αN-Tpav of the basic fuel injection amount α'N-Tp calculated in step 6 is calculated according to the following calculation formula.

Here, αN− used in the above weighted average calculation (smoothing process)
TI)AV is the weighted average value αN-Tpav calculated in step 7 during the previous execution of this routine, and 2X is a constant indicating weighting with respect to the previous value.

Then, in step 8, the basic fuel injection amount αN-Tp that approximately follows the true engine load change calculated in step 6 is determined.
DαN-
Tp(←αN-Tp-αN-TPav) is calculated. The above DαN-Tp is the difference between the value before the weighted average and the value after the weighted average, and this DαN-Tp is the difference between the value before the weighted average (
This shows how much error occurs in αN -T p a v with respect to the basic fuel injection amount αN - T p which approximately corresponds to the true engine load due to smoothing processing.

In the next step 9, the basic volumetric efficiency KPB is searched from the map based on the intake pressure PB detected by the intake pressure sensor 9. Similar to the map of the basic volumetric efficiency QHφ in step 4, the map used here is based on the basic volumetric efficiency KPB corresponding to the intake pressure PB.
was determined and set through experiments.

In step 10, the basic volumetric efficiency KPB, which was found by searching from the map in step 9, is multiplied by the minute correction coefficient KFLAT, which is found by searching from the map based on the intake pressure PB and engine speed N in the background job described later. Then, the volumetric efficiency KQCYL is calculated.

Then, in the next step 11, a basic fuel injection amount Tp-PB (state quantity dependent parameter) based on the intake pressure PH is calculated according to the following equation.

'rp-P B +KCONDXKQCYLX P B
where KCOND is a constant, KQCYL is the volumetric efficiency obtained in step 10, PB is the intake pressure detected by the intake pressure sensor 9, and KTA is the intake air temperature detected by the intake air temperature sensor 6 in the background job described later. This is an intake air temperature correction coefficient set by searching from a map based on TA.

In step 12, the weighted average value TI)-PBAII of the basic fuel injection amount Tp-PB calculated in step 11 is calculated according to the following formula.

If the basic fuel injection amount Tp-PB set based on the intake pressure PB is calculated as a weighted average (smoothing process) as described above, even if pressure pulsation is detected by the intake pressure sensor 9,
The basic fuel injection amount Tp-P after the weighted average of this pressure pulsation
This can prevent the occurrence of a large fluctuation in the basic fuel injection amount Tp-PBav that does not correspond to changes in the engine-required fuel amount due to the influence on BAV.

In addition, in the above weighted average calculation formula, Tp-P B M
If V is replaced with αN-Tpav and Tp-PB is replaced with αN-Tp, it becomes the same as the weighted average calculation in step 7, and the basic fuel injection amount αN-Tp (opening area (dependent parameter) and the basic fuel injection amount Tp-PB (state quantity dependent parameter) based on the intake pressure PB are smoothed with similar characteristics by similar weighted average calculations.

In the next step 13, the difference Da between the aperture area dependent parameters calculated in step 8 before and after weighted averaging is calculated.
Whether or not N-Tp is approximately zero, in other words, αN-T
It is determined whether p and αN-TI)AV are substantially equal.

When the DαN-Tp is approximately zero, the opening area A
The basic fuel injection amount αN-, which is not affected by pressure pulsations and roughly follows the true engine load change, is calculated from the engine rotational speed N and
In other words, a state in which Tp and the weighted average value αN -T pav of the basic fuel injection amount αN - Tp are approximately equal, and no response delay to the true engine load occurs due to the weighted average calculation (smoothing process). , indicates that even if the weighted average calculation result is used, the basic fuel injection amount TP that substantially corresponds to the engine required amount is set.

On the other hand, when DctN-Tp is not approximately zero, it can be considered that a deviation occurs before and after the weighted average due to a delay in response to a true engine load change due to the weighted average calculation.

In addition, the basic fuel injection amount αN-Tp set based on the opening area A and the engine rotational speed N is calculated using the calculation formula used when weighted averaging the basic fuel injection amount Tp-PB set based on the intake pressure PB. Since the above-mentioned DαN-Tp is approximately zero, the presence or absence of a response delay is determined by determining the occurrence of a response delay in the basic fuel injection amount Tp-PB based on the intake pressure PB. It also means that you are making a judgment.

That is, since the basic fuel injection amount Tp-PB calculated in step 11 based on the intake pressure PB fluctuates due to the influence of pressure pulsations, a weighted average is applied in the next step 12 to attenuate the pulsations. , by performing a weighted average operation, we get
A response delay of the weighted average basic fuel injection amount Tp-PBAv occurs with respect to a change in the intake pressure PB. On the other hand, the basic fuel injection amount αN-Tp is set to follow the true engine load change based on the opening area A and the engine rotation speed N.
Although the accuracy of fuel setting is inferior, it is not affected by pressure pulsations and changes approximately following true engine load changes.

Therefore, if weighted averaging is performed in the same manner as this weighted average calculation of αN-Tpt-Tp-PB, αN-T after weighted averaging
pAy should show almost the same response delay as Tp-PB ay, and since αN-Tp has no response delay, the response delay due to smoothing of Tp-PBav is αN-
This can be considered to substantially match Tp-αN-Tpav (see FIG. 5).

Therefore, in the fuel supply control in this embodiment, the response delay occurrence situation based on the weighted average of the basic fuel injection amount Tp - PB based on the intake pressure PB is determined based on the basic fuel injection amount set based on the opening area A and the engine rotational speed N. A simulation is performed using αN-Tp, and the basic fuel injection amount Tp-PB is weighted and averaged so that the response delay that occurs to avoid the influence of pressure pulsation can be determined from the basic fuel injection amount αN-Tp. It can be said.

Therefore, when it is determined in step 13 that the DαN-Tp is not zero, the basic fuel injection amount Tp- based on the intake pressure PH is calculated using a weighted average to avoid pressure pulsation.
“There is a response delay in PBav, and in this case, the process advances to step 14 and the basic fuel injection amount T p-
Corrects the response delay of P B av.

In step 14, the basic fuel injection amount Tp-PBav with the response delay obtained by the weighted average in step 12 is added to the basic fuel injection amount Tp-PBav.
By adding αN-Tp, the basic fuel injection amount Tp
- Apply an increase/decrease correction to P B av corresponding to the response delay.

On the other hand, when it is determined in step 13 that the DαN-Tp is approximately zero, in the simulation based on the basic fuel injection amount αN-Tp, which is the opening area dependent engine load parameter, the weighting of the basic fuel injection amount Tp-PB is In this case, the response delay caused by the averaging calculation is not recognized, and in this case, the weighted average result also substantially meets the engine requirements, so the process jumps to step 15 without making any correction to compensate for the response delay.

In step 15, the volumetric efficiency QCYL calculated in step 5 this time is set to CYLO corresponding to the previous value in order to calculate the body bath movement rate QCYL in step 5 next time.

In the above embodiment, in step 8, αN-Tp to αN
-'rpA, is added to the basic fuel injection amount Tp-PBA in step 14 to correct the response delay, but instead of calculating the deviation, αN
-Tp/αN-TI)at is calculated, and based on the division result, it is determined whether or not a response delay has occurred, and the basic fuel injection amount Tp-PBAV is multiplied by the division result to respond to Tp-PBav. It may be configured so that delay correction is performed, in which case αN-Tp/αN-
The configuration may be such that whether or not a response delay occurs is determined based on whether Tp and By are approximately l.

As mentioned above, the basic fuel injection amount Tp-PB set based on the intake pressure PB is weighted averaged to suppress the influence of pressure pulsation, and the basic fuel injection amount Tp-PB set based on the opening area A and the engine speed N is further suppressed. The basic fuel injection amount Tp-PBa is calculated by compensating for the response delay due to the weighted average according to the injection amount αN-Tp.
When v is set, the final fuel injection amount Ti is set using this basic fuel injection amount Tp-PBmv according to the following formula.

T i ”Tp-P Bsv×COE F XLAMB
D^+Ts Here, the C0EF is various correction coefficients that are set according to the engine operating state based on the cooling water temperature Tw detected by the water temperature sensor 12, and the LAMBDA is the correction coefficient that is set based on the cooling water temperature Tw detected by the water temperature sensor 12. 14
The basic fuel injection amount Tp-PBav is adjusted so that the air-fuel ratio of the intake air-fuel mixture detected at
Further, Ts is a correction factor for correcting a change in the effective opening time of the fuel injection valve IO due to the battery voltage. As mentioned above, in calculating the final fuel injection amount Ti, the basic fuel injection amount αN based on the opening area A and the engine rotational speed N is used.
-TporαN-TpAv is not used, and is used only for correcting the response delay of the basic fuel injection amount Tp-PBav based on the intake pressure PB.

The fuel injection amount Ti is set according to the above equation.7 This fuel injection amount Ti is set in the output register. As a result, at a predetermined fuel injection timing, the latest fuel injection amount Ti set in this output register is read out, and an injection pulse signal with a pulse width equivalent to this fuel injection amount Ti is sent to the fuel injection valve lO. As a result, the fuel injection valve 10 is opened for a time corresponding to Ti, and fuel is intermittently injected and supplied to the engine 1.

In this way, in this embodiment, the basic fuel injection amount Tp-PBav set based on the intake pressure PB is weighted averaged to avoid fluctuations in the basic fuel injection amount Tp-PBav due to pressure pulsations, and The basic fuel injection amount αN-Tp obtained from the opening area A and the engine rotational speed N is calculated as a weighted average in the same manner as Tp-PB to determine the occurrence of response delay due to the weighted average (smoothing process), and the weighted average is calculated. The response delay of the basic fuel injection amount Tp - PB□ is the basic fuel injection amount α
The correction was made based on the comparison results before and after the weighted average of N-Tp.

Therefore, according to this embodiment, the air-fuel ratio (basic fuel injection amount Tp
-PB4v) can perform highly responsive fuel supply control that follows changes in the required fuel amount (true engine load changes) during transient operation of the engine 1 while avoiding fluctuations in the air-fuel ratio. This improves controllability and prevents deterioration of exhaust properties and output pulsation. In addition, instead of a configuration in which the steady state/transient state of the engine 1 is determined on and off, and the control is switched between control that can avoid the influence of pressure pulsation and control that ensures responsiveness, depending on the determination, a weighted average ( Since the correction commensurate with the amount of response delay caused by smoothing processing is continuously performed, there is no fear that control variations (control steps) will occur.

Next, a background job for setting coefficients used in each calculation in the routine shown in the flowchart of FIG. 3 will be explained according to the routine shown in the flowchart of FIG. 4.

The routine shown in the flowchart of FIG. 4 is executed as a background job, and first, in step 21, the intake air temperature used for calculating the basic fuel injection amount Tp in step 6 and step 11 in the flowchart of FIG. The correction coefficients KTA and KTA2 are searched and set based on the intake air temperature TA from each map.

In the next step 22, FLAT is searched from a map based on the intake pressure PB and the engine rotational speed N to obtain the minute correction coefficient used for setting the volumetric efficiency KQCYL in step 10 in the flowchart of FIG.

In the above embodiment, a configuration was described in which the influence of pressure pulsation was avoided by weighted averaging of the basic fuel injection amount Tp-PB set based on the detected intake pressure PB. Even in the case where the intake pressure, PB including pressure pulsations detected by the sensor 9 is weighted averaged and smoothed and then used for calculating the basic fuel injection amount Tp, the transient response is calculated in the same manner as in this embodiment. can be ensured.

A second embodiment configured to perform the weighted average calculation of the intake pressure PH and the response delay correction of the weighted average result as described above will be described in accordance with the routine shown in the flowchart of FIG.

The routine shown in the flowchart of FIG. 6 is executed at predetermined minute intervals of about 4s+s, and steps 31 to 35 of this routine are similar to steps 1 to 5 in the flowchart of FIG. 3 described above. Since this is a calculation, the explanation will be omitted and will be explained starting from step 36.

In step 36, the volumetric efficiency QCYL that follows the true engine load change obtained from the opening area A and the engine rotational speed N is determined.
The weighted average calculation of (opening area dependent engine load parameter) is performed according to the following formula.

z'' Here, QCYLav used in the weighted average calculation is the weighted average result calculated in step 36 during the previous execution of this routine, and 2x is a constant indicating weighting for this previous value.

Then, in the next step 37, the ratio QCYL (←QCYL/QC
YLav ) is calculated. In addition, the above QCYL and QCYL
AV is α in the flowchart of Figure 3, respectively.
This corresponds to N-Tp and αN-TPav.

In the next step 38, the intake pressure PB detected by the intake pressure sensor 9 is input, and in step 39, the intake pressure PB (state quantity dependent engine load parameter) input this time is input.
The weighted average calculation of PBav and the previous weighted average value PBav is performed according to the following formula.

2I'' Here, PBo in the above calculation formula is changed to QCYLAv,
Furthermore, if PB is replaced with QCYL, the calculation formula for the weighted average of the volumetric efficiency QCYL in step 36 described above becomes the same, and the intake pressure PB and the volumetric efficiency QCYL are weighted averaged (smoothed) using the same smoothing characteristics. Therefore, the response delay to the true engine load due to the weighted average of the intake pressure PB is expressed as the ratio DQCYL of the volumetric efficiency QCYL and the weighted average value QCYLAV.

Therefore, in step 40, the ratio DQC between the volumetric efficiency QCYL obtained in step 37 and the weighted average value QCYLAv is
Depending on whether YL is approximately 1 (whether the volumetric efficiency QCYL and the weighted average value QCYLAV of this volumetric efficiency QCYL are approximately equal or not), the intake pressure PB is calculated as a weighted average and smoothed, and as a result, the true intake pressure is calculated. It is determined whether a response delay has occurred with respect to pressure PB.

If it is determined in step 40 that the ratio DQCYL is not approximately 1, and as a result of the weighted average processing (smoothing processing), a response delay has occurred relative to the true intake pressure PB, the process proceeds to step 41, where the weighted average value PBAv Correct the response delay according to the following formula.

P B av"DQcYL X P B ayHere,
Since DQCYL←QCYL/QCYLav, for example, in the acceleration state of engine l, there is a delay in the increase in the weighted average value QCYLAV with respect to the true volumetric efficiency QCYL, and DQC
When YL>1, the above weighted average value PBA
By the correction calculation of v, the weighted average value PBAv corresponding to the response delay is corrected to increase and can be brought closer to the true intake pressure PB.

On the other hand, if it is determined in step 41 that the DQCYL is approximately l, the volumetric efficiency 111cYL that follows the true volumetric efficiency (engine load) change and the weighted average result of the volumetric efficiency QCYL are approximately equal; Since it is simulated that no response delay occurs due to weighted averaging (smoothing processing), there is almost no response delay for the weighted average value PBav of the intake pressure PB, and the approximately true intake pressure PB is detected. It can be considered that there is. Therefore, in this case, the response delay correction in step 41 is not performed, in other words, the DQCYL is approximately 1 and the result is the same even if the correction calculation is performed, so step 41 is skipped and step 41 is performed. Proceed to 42.

In step 42, the volumetric efficiency QCYL calculated in step 35 this time is
Set L to the previous value QCYLO.

In this way, the intake pressure PB detected by the intake pressure sensor 9
is sampled at minute intervals and a weighted average calculation is performed to attenuate the influence of pressure pulsations, while the volumetric efficiency QCYL, which is not affected by pressure pulsations and determined from the opening area A and the engine rotational speed N, is calculated as the intake pressure PB. Similarly, by weighted averaging, the occurrence of a response delay due to weighted averaging (smoothing processing) is simulated, and the weighted average value PBA of the intake pressure PB is corrected according to the response delay calculated from the simulation result. Therefore, according to the above embodiment, it is possible to avoid the influence of pressure pulsation by weighted averaging (smoothing processing) and suppress the occurrence of response delay due to weighted averaging, and to adjust the intake pressure PBav for setting the fuel injection amount to the required fuel of engine l. It can be set to a true value corresponding to the amount.

In the above embodiment, the pressure pulsation is attenuated by calculating the weighted average of the values detected by the intake pressure sensor 9, but the electrical detection signal from the intake pressure sensor 9 is inputted to the microcomputer via a filter circuit. In this case, the volumetric efficiency QCYL obtained from the opening area A and the engine rotational speed N may be set as the time constant of the filter circuit. The response delay may be simulated by performing a weighted average calculation using a weight corresponding to .

As described above, the weighted average value P of the intake pressure is finally set to avoid the influence of pressure pulsation and ensure responsiveness.
BAV is used to calculate the basic fuel injection amount Tp according to the calculation formula shown in step 11 of the flowchart in FIG. The final fuel injection amount TI is set.

In addition, in the above two embodiments, a fuel supply control device generally called the D-Jetro method in which fuel injection amount control is performed based on the intake pressure PB detected by the intake pressure sensor 9 has been described. In a fuel supply control device generally called the L-JETRO method, the fuel injection amount is controlled based on the intake air flow rate Q, which is the state quantity of the intake air detected by the air flow meter. Similarly to this embodiment, by smoothing the detected values and correcting the response delay based on the simulation results, it is possible to avoid the pulsation effect and ensure responsiveness.

That is, even when an air flow meter is provided, in order to avoid the influence of pulsation on the intake air flow rate Q detected by the air flow meter, the detected values may be subjected to a weighted average calculation or the detected signal may be inputted after passing through a filter circuit. In addition, a weighted average calculation is performed on the basic fuel injection amount Tp set based on the intake air flow rate Q including pulsation. On the other hand, the occurrence of the response delay due to the smoothing process as described above can be determined using the volumetric efficiency QCYL (intake air amount), the basic fuel injection amount Tp, etc., which are determined from the opening area A and the engine rotational speed N, as in the previous embodiment. The engine load parameter dependent on the opening area is simulated by smoothing (e.g., weighted average) using the smoothing process and characteristics such as road distance, and the intake air flow rate Q and It may be configured to correct the response delay of the smoothed value of the basic fuel injection amount Tp (state quantity dependent engine load parameter) based on the intake air flow rate Q.

<Effects of the Invention> As explained above, according to the present invention, the intake air fal
The engine load parameter set based on the l quantity or the state quantity is smoothed, while the engine load parameter set based on the opening area of the engine intake system and the engine rotational speed is smoothed based on the smoothing characteristic value in the smoothing process. Since the smoothed parameters are corrected and set, it is possible to avoid the influence of pressure pulsation through the smoothing process and eliminate the response delay caused by the smoothing process, thereby improving the response of the air-fuel ratio control during transient operation. This has the effect of ensuring stable performance and preventing air-fuel ratio fluctuations during steady operation.

In addition, the engine load parameters set based on the opening area of the engine intake system and the engine rotational speed are smoothed using parameters based on the intake air state quantity and the smoothing characteristics of road gaps, etc. The smoothing process is performed by assuming that the difference between the parameters before and after the smoothing process is the response delay due to the smoothing process, and applying corrections corresponding to the response delay to the parameters based on the intake air state quantity. It is possible to accurately capture the response delay due to this and perform optimal correction.

In addition, the smoothing process of the state quantity of intake air or the engine load parameter set based on the state quantity may be performed by weighted average calculation, and in this case, the engine load parameter based on the opening area is also given the same weighted weight. If the smoothing process is performed using a weighted average calculation, it is possible to detect a response delay due to a weighted average of parameters according to the state quantity of intake air via a weighted average of engine load parameters based on the opening area.

Furthermore, the detection signal of the state quantity of the intake air may be configured to be smoothed by a filter circuit, and in this case, the engine load parameter based on the opening area is averaged by weighting according to the time constant of the filter circuit. Then, the response delay caused by the filter circuit can be simulated using the weighted average.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a system schematic diagram showing an embodiment of the present invention, and FIGS. 3 and 4 are flowcharts showing a first embodiment of control according to the present invention, respectively. , FIG. 5 is a time chart showing the characteristics of the control shown in the flowchart of FIG. 3, FIG. 6 is a flowchart showing a second embodiment of the control according to the present invention, and FIG. 7 explains problems with conventional control. This is a time chart for 1...11 Seki 7...Throttle valve 8...
Throttle sensor 9... Intake pressure sensor 10.
・Fuel injection valve 11 ・Control unit 15 ・
...Crank angle sensor patent applicant Fujio Sasashima, agent of Japan Electronics Co., Ltd., patent attorney

Claims (4)

[Claims] (1) An intake air state quantity detection means for detecting the state quantity of the engine intake air, and a smoothing process for the intake air state quantity detected by the intake air state quantity detection means or the engine load parameter set based on the state quantity. an opening area detection means for detecting an opening area of an engine intake system that is variably controlled; an engine rotational speed detection means for detecting an engine rotational speed; an engine load parameter setting means for setting an engine load parameter based on the engine load parameter setting means; and a smoothing process performed by the smoothing processing means based on the engine load parameter set by the engine load parameter setting means and the smoothing characteristic value in the smoothing processing means. smoothing processing parameter correction means for correcting and setting parameters; fuel supply amount setting means for setting a fuel supply amount based on the parameters corrected and set by the smoothing processing parameter correction means; 1. A fuel supply control device for an internal combustion engine, comprising: fuel supply control means for controlling fuel supply to the engine based on a fuel supply amount. (2) The smoothing parameter correction means includes a smoothing processing means for smoothing the engine load parameter set by the engine load parameter setting means with a smoothing characteristic substantially equivalent to that of the smoothing processing means; Setting a correction value for correcting and setting the parameter smoothed by the smoothing processing means based on the difference between the engine load parameter smoothed by the processing means and the engine load parameter set by the engine load parameter setting means. correction value setting means for
2. The fuel supply control device for an internal combustion engine according to claim 1, wherein the fuel supply control device includes: (3) The smoothing process in the smoothing processing means is performed by calculating a weighted average of the intake air state quantity detected by the intake air state quantity detection means or the engine load parameter set based on the state quantity, and 3. The fuel for an internal combustion engine according to claim 2, wherein the smoothing process in the same characteristics smoothing process means is performed by calculating a weighted average of engine load parameters with the same weight as the weighted average calculation. Supply control device. (4) The smoothing processing means is constituted by a filter circuit that smoothes and outputs the detection signal from the intake air state quantity detection means, while the smoothing processing in the same characteristic smoothing processing means is performed by the filter circuit. 3. The fuel supply control device for an internal combustion engine according to claim 2, wherein the control is performed by calculating a weighted average of engine load parameters using a weighted weight according to a constant.