JP2016205160A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce time length required until an actual air amount is converged into a target value while suppressing overshoot of the actual air amount when a target air amount is rapidly varied.SOLUTION: In a control device for an internal combustion engine having an intake passage 11 connected to an internal combustion engine body and a throttle valve 12 disposed in the intake passage 11, when a target air amount variation amount which is a difference between a current target air amount acquired by target air amount acquiring means and a previous target air amount is determined to be larger than a maximum variation amount Δmcalculated by maximum variation amount calculating means (S110), target air amount correcting means corrects a value of the current target air amount to be the sum of the previous target air amount acquired by the target air amount acquiring means and the maximum variation amount Δmcalculated by the maximum variation amount calculating means (S112).SELECTED DRAWING: Figure 13

Description

  The present invention relates to a control device for an internal combustion engine in which a throttle valve is disposed in an intake passage, and in particular, when the target air amount suddenly changes, the actual air amount reaches a target value while suppressing overshoot of the actual air amount. The present invention relates to a control device for an internal combustion engine that can shorten the time required for convergence.

  2. Description of the Related Art Conventionally, an intake air amount control device for an internal combustion engine in which a throttle valve (throttle valve) is disposed in an intake passage (intake pipe) is known. As an example of this type of intake air amount control device for an internal combustion engine, there is one described in Patent Document 1, for example. Japanese Patent Laid-Open No. 2004-26883 discloses that the change rate of the target throttle opening is guarded with a predetermined guard value, and that the required intake air amount is converted into a post-model required intake air amount by a reference model when the required intake air amount changes suddenly. It is described that the internal variable used at the time is corrected so that the change speed of the target throttle opening is hardly guarded by the guard value, and the overshoot of the actual intake air amount with respect to the required intake air amount is suppressed.

JP 2011-99354 A

By the way, the intake air amount control device for an internal combustion engine disclosed in Patent Document 1 can suppress overshoot of the actual intake air amount with respect to the required intake air amount, but corrects the internal variable when the required intake air amount changes suddenly. In addition, the responsiveness of the required post-model intake air amount temporarily decreases. That is, in the intake air amount control device for an internal combustion engine disclosed in Patent Document 1, when the target air amount suddenly changes, the time required for the actual air amount to converge to the target value is suppressed while suppressing the overshoot of the actual air amount. It cannot be shortened sufficiently.
Further, the relationship between the responsiveness of the throttle opening and the air amount changes according to the load. Specifically, responsiveness is worse when the load is low than when the load is high. For this reason, when the guard value is set according to the high load, for example, when the guard is set at the throttle opening during the transition from the high load to the low load, the actual air amount when the load changes to the low load is obtained. It may take time to converge to the target air amount, and controllability may deteriorate.

  In view of the above problems, the present invention can reduce the time required for the actual air amount to converge to the target value while suppressing the overshoot of the actual air amount when the target air amount suddenly changes. An object of the present invention is to provide an engine control device.

According to the present invention, an internal combustion engine body;
An intake passage connected to the internal combustion engine body;
In a control device applied to an internal combustion engine comprising a throttle valve disposed in the intake passage,
Target air quantity acquisition means;
Throttle front-rear data acquisition means for acquiring the pressure and temperature upstream of the throttle valve and the pressure downstream of the throttle valve;
Throttle effective opening area acquisition means for acquiring a throttle effective opening area that is an opening cross-sectional area of the intake passage at the position of the throttle valve;
An air amount acquisition means for acquiring the amount of air passing through the throttle valve;
A throttle effective opening area maximum change amount acquisition means for acquiring a throttle effective opening area maximum change amount which is a maximum change amount of the throttle effective opening area;
Maximum air for calculating the maximum amount of air passing through the throttle valve based on the pressure and temperature on the upstream side of the throttle valve, the pressure on the downstream side of the throttle valve, the throttle effective opening area, and the maximum change amount of the throttle effective opening area A quantity calculating means;
Maximum change amount calculating means for calculating a maximum change amount which is a difference between the maximum air amount calculated by the maximum air amount calculating means and the air amount acquired by the air amount acquiring means;
A target air amount correcting means is provided in the control device;
When the target air amount change amount, which is the difference between the current target air amount acquired by the target air amount acquisition means and the previous target air amount, is larger than the maximum change amount calculated by the maximum change amount calculating means. ,
The target air amount correction means calculates the value of the current target air amount as a sum of the previous target air amount acquired by the target air amount acquisition means and the maximum change amount calculated by the maximum change amount calculation means. A control device for an internal combustion engine is provided which is corrected to the value of.

That is, in the control device for an internal combustion engine of the present invention, when the target air amount change amount, which is the difference between the current target air amount and the previous target air amount, is larger than the maximum change amount of the air amount passing through the throttle valve. The current target air amount is corrected to the sum of the previous target air amount and the maximum change amount. Specifically, the maximum change amount is based on the pressure and temperature on the upstream side of the throttle valve, the pressure on the downstream side of the throttle valve, and the maximum change amount of the throttle effective opening area.
In other words, in the control apparatus for an internal combustion engine of the present invention, when the target air amount changes suddenly, the pressure and temperature on the upstream side of the throttle valve, the pressure on the downstream side of the throttle valve, and the maximum change amount of the throttle effective opening area Regardless of the air amount control, the air amount control is not executed based on the target air amount calculated according to, for example, the fuel injection amount, the engine rotation speed, the presence or absence of EGR, etc., but the pressure and temperature upstream of the throttle valve Then, the target air amount is corrected based on the pressure on the downstream side of the throttle valve and the maximum change amount of the throttle effective opening area, and precise air amount control is executed. Therefore, when the target air amount suddenly changes, the pressure and temperature upstream of the throttle valve, the pressure downstream of the throttle valve, and the case where the air amount control is executed regardless of the maximum amount of change in the effective throttle opening area. In addition, overshooting of the actual air amount when the target air amount suddenly changes can be suppressed.
Further, in the control device for an internal combustion engine of the present invention, the air amount control is performed without setting the guard value to the changing speed of the target throttle opening as in the intake air amount control device for the internal combustion engine described in Patent Document 1. Is executed. Therefore, the time required for the actual air amount to converge to the target value can be shortened as compared with the intake air amount control device for the internal combustion engine described in Patent Document 1.
That is, in the control device for an internal combustion engine of the present invention, when the target air amount changes suddenly, it is possible to reduce the time required for the actual air amount to converge to the target value while suppressing overshoot of the actual air amount. it can.

  According to the present invention, when the target air amount suddenly changes, the time required for the actual air amount to converge to the target value can be shortened while suppressing the overshoot of the actual air amount.

It is a figure for demonstrating the outline | summary of throttle control. It is the figure which showed the operating condition for DPF reproduction | regeneration. It is the figure which showed the target air quantity and the actual air quantity when it switches from the state with EGR to the state without EGR. 1 is a schematic configuration diagram illustrating a main part of an engine system to which a control device for an internal combustion engine according to a first embodiment is applied. It is the figure which showed the control apparatus 18 which comprises some engine systems with which the control apparatus of the internal combustion engine of 1st Embodiment is applied. It is a figure for demonstrating the sudden change of the target air amount at the time of EGR cut. It is a figure for demonstrating the outline | summary of the throttle control of the control apparatus of the internal combustion engine of 1st Embodiment. It is a figure for demonstrating the reason which must correct target air quantity like the example shown in FIG. Time for explaining an example in which the air amount control of the control device for the internal combustion engine of the first embodiment shown in FIG. 12 is applied and the current target air amount is corrected in step S112 of FIG. It is a chart. It is a figure for _{demonstrating} real air quantity (flow volume) m, throttle effective opening area microampere, pre-throttle pressure _Pus , pre-throttle temperature _Tus, and post-throttle pressure _Pds . FIG. 6 is a diagram illustrating a relationship between a ratio P _ds / P _us between a post-throttle pressure P _ds and a pre-throttle pressure P _us and the coefficient φ in the formulas 1 and 2. It is a figure for demonstrating the view which corrects the target air quantity in the control apparatus of the internal combustion engine of 1st Embodiment. It is the figure which showed the air quantity control flowchart in the control apparatus of the internal combustion engine of 1st Embodiment. It is the figure which showed the application example (primary delay system) of the delay element with respect to target air amount. It is a figure for demonstrating the view which corrects the target air quantity in embodiment of the invention relevant to this invention. It is the figure which showed the air quantity control flowchart in embodiment of the invention relevant to this invention.

Before describing the first embodiment of the control apparatus for an internal combustion engine of the present invention, an outline of throttle control will be described. FIG. 1 is a diagram for explaining an outline of throttle control. As a technique for controlling the amount of air using a throttle valve, the throttle control shown in FIG. 1 is known and generally used. In the example shown in FIG. 1, the throttle model 1 estimates the throttle opening after a predetermined period of time, for example, based on the target air amount acquired according to, for example, the fuel injection amount, the engine speed, the presence or absence of EGR, and the like ( In other words, feed-forward control is performed). Further, the actual air amount obtained as the plant (engine) response of the throttle opening is fed back to the throttle opening by the FB (feedback) control device 2.
What is described in FIG. 2 of Patent Document 1 is based on the throttle control of FIG. 1 described above, and is for suppressing air amount overshoot.

FIG. 2 is a diagram showing the operating conditions for DPF (Diesel Particle Filter) regeneration.
During DPF regeneration, at a low load, “no EGR” is set to increase the exhaust temperature. On the other hand, at a certain load or higher, “EGR present” is set to suppress NOx emission while raising the exhaust gas temperature. Although not shown, during normal operation other than during DPF regeneration, “EGR present” is set even at a low load.
FIG. 3 is a diagram showing the target air amount and the actual air amount when switching from the state with EGR to the state without EGR. When the state with EGR is switched to the state without EGR as shown in FIG. 2, the target air amount calculated based on the fuel injection amount, the engine speed, the presence or absence of EGR, etc., as shown by the broken line in FIG. Increases rapidly. When the general throttle control shown in FIG. 1 is executed when the target air amount increases abruptly as shown by a broken line in FIG. 3, the actual air amount becomes the target as shown by the solid line in FIG. It overshoots the air volume.
Since the engine control system described in FIG. 1 of Patent Document 1 does not include an EGR system, in the engine control system described in FIG. 1 of Patent Document 1, the engine control system described in FIG. Corresponding air volume control is performed using a throttle valve.
That is, since the target air amount may change suddenly regardless of the presence or absence of the EGR system, it can be said that it is necessary to improve the controllability of the air amount when the target air amount changes suddenly.

By the way, in a vehicle engine equipped with a DPF which is a catalyst for collecting and depositing soot discharged from the engine, both of them are shown in FIG. 2 in order to regenerate (oxidize and burn) PM (soot) deposited on the DPF. As indicated by a directional arrow, it is required to drive while switching between a state with EGR and a state without EGR.
When the target air amount suddenly increases as shown by the broken line in FIG. 3 in accordance with the switching from the state with EGR to the state without EGR, the actual air amount becomes the target as shown by the solid line in FIG. When overshooting the air amount, the exhaust temperature becomes low, and the PM regeneration performance deteriorates (fuel consumption deterioration, regeneration time extension).
Therefore, it can be said that in an engine of a vehicle equipped with a DPF, it is necessary to precisely execute air amount control using a throttle valve / EGR valve when switching from a state with EGR to a state without EGR.

  Hereinafter, a first embodiment of a control device for an internal combustion engine of the present invention will be described. FIG. 4 is a schematic configuration diagram showing a main part of an engine system to which the control device for an internal combustion engine of the first embodiment is applied. In the example shown in FIG. 4, the EGR passage 16 and the EGR valve 17 are provided. However, in another example, the present invention may be applied to an engine system in which the EGR passage 16 and the EGR valve 17 are not provided. it can. The control device for an internal combustion engine of the present invention is applied to, for example, a diesel engine. However, the control device for an internal combustion engine of the present invention may be applied to an engine other than a diesel engine, such as a gasoline engine. it can.

In the engine system to which the control device for an internal combustion engine of the first embodiment is applied, an intake passage 11 connected to the internal combustion engine body is provided as shown in FIG. A throttle valve 12 is disposed in the intake passage 11.
In the example shown in FIG. 4 in which the EGR passage 16 and the EGR valve 17 are provided, the throttle valve 12 is disposed upstream of the connection position of the intake passage 11 and the EGR passage 16 in the intake passage 11. .
In the example shown in FIG. 4, a pressure sensor 13 is provided for detecting a pre-throttle pressure _Pus that is a pressure upstream of the throttle valve 12. Further, a temperature sensor 14 is provided for detecting a pre-throttle temperature _Tus that is the temperature upstream of the throttle valve 12. Further, a pressure sensor 15 is provided for detecting a post-throttle pressure P _ds that is a pressure on the downstream side of the throttle valve 12.
In another example to which the control device for an internal combustion engine of the present invention is applied, the pre-throttle pressure P _us , the pre-throttle temperature _Tus or the post-throttle pressure P _ds may be estimated instead based on the operating conditions of the engine. .

In the engine system to which the control device for the internal combustion engine of the first embodiment is applied, the amount of air (actual air amount) m that passes through the throttle valve 12 (see FIG. 4) is calculated based on Equation 2 described later. .
In another example to which the control device for an internal combustion engine of the present invention is applied, a sensor for detecting the amount of air (actual air amount) m passing through the throttle valve 12 may be provided instead.

FIG. 5 is a view showing a control device (ECU) 18 constituting a part of an engine system to which the control device for an internal combustion engine of the first embodiment is applied.
In the control apparatus for an internal combustion engine according to the first embodiment, as shown in FIG. 5, the target air amount is, for example, a fuel injection amount, an engine rotation speed, and the like by a target air amount acquisition unit (not shown) of the control device 18. It is calculated and acquired based on the presence or absence of EGR. Further, an air amount (actual air amount) m that passes through the throttle valve 12 (see FIG. 4) is calculated by an air amount acquisition means (not shown) of the control device 18 based on, for example, Equation 2 described later, and acquired. Is done.
Moreover, a throttle pressure before _{P us} detected by the pressure sensor 13 (see FIG. 4), a throttle temperature before _{T us} detected by the temperature sensor 14 (see FIG. 4), detected by a pressure sensor 15 (see FIG. 4) The post-throttle pressure P _ds thus obtained is acquired by the throttle front / rear data acquisition means (not shown) of the control device 18 as throttle front / rear data which is upstream and downstream data of the throttle valve 12.
Further, the control device 18 outputs a signal for driving the throttle valve 12 (see FIG. 4) so as to reach a predetermined throttle opening based on the calculated and acquired values.
Further, in the example shown in FIG. 4, the control device 18 outputs a signal for driving the EGR valve 17 (see FIG. 4) so as to have a predetermined opening.

FIG. 6 is a diagram for explaining a sudden change in the target air amount at the time of EGR cut. In a general engine system having the same configuration as the example shown in FIG. 4 to which the present invention is not applied, the EGR valve 17 (see FIG. 4) is fully closed as shown in FIG. When the EGR cut is executed, the state is changed from “with EGR” to “without EGR” as shown by an arrow in FIG. 6A, and as a result, as shown by a solid line in FIG. 6B. In addition, for example, the target air amount calculated according to the fuel injection amount, the engine rotation speed, the presence or absence of EGR, and the like rapidly increases.
Further, as the target air amount increases rapidly, the throttle valve 12 is opened as shown in FIG. Further, since the influence of the high-pressure EGR gas is cut off along with the EGR cut, the post-throttle pressure (post-throttle pressure P _ds applied to the diesel engine) suddenly changes as indicated by an arrow in FIG. To do. That is, the target air amount and the downstream state of the throttle valve 12 change suddenly at the same time.
As a result, as shown by a broken line in FIG. 6B, the actual air amount m overshoots.

FIG. 7 is a diagram for explaining an outline of throttle control of the control apparatus for an internal combustion engine according to the first embodiment. Unlike the general throttle control shown in FIG. 1, in the control device for the internal combustion engine of the first embodiment, as shown in FIG. 7, the target correction device 3 that functions as target air amount correction means is a control device 18 ( (See FIG. 5).
That is, in the example shown in FIG. 7 to which the control device for the internal combustion engine of the first embodiment is applied, the target air amount is, for example, the fuel injection amount by the target air amount acquisition means (not shown) of the control device 18. It is calculated and acquired based on the engine speed, the presence or absence of EGR, and the like. Then, as will be described in detail later, the target air amount is corrected by the target correcting device 3, and based on the corrected target air amount, the throttle model 1 determines the throttle opening after a predetermined period of time, for example. Estimate (that is, feedforward control). Further, an actual air amount m obtained as a plant (engine) response of the throttle opening is fed back to the throttle opening by the FB (feedback) control device 2.

FIG. 8 is a diagram for explaining the reason why the target air amount must be corrected as in the example shown in FIG. In FIG. 8, the vertical axis indicates the load, the horizontal axis indicates the engine rotation speed, and the brackets in FIG. 8 indicate the throttle opening. As shown in FIG. 8, when the throttle opening changes from 70% to 90%, the change in the throttle opening is equivalent to 20%, and the change in the throttle opening is small. On the other hand, when the throttle opening changes from 50% to 90%, the change in the throttle opening is equivalent to 40%, and the change in the throttle opening increases.
When the change in the throttle opening is large, the actual air amount converges to the target value when the change speed of the target throttle opening is guarded by the upper limit speed guard value as in the example shown in FIG. It takes a long time.

In view of this problem, in the control device for the internal combustion engine of the first embodiment, the target correction device 3 (see FIG. 7) is used to reduce the time required for the actual air amount m to converge to the target value. Control for correcting the air amount is executed. FIG. 12 is a view for explaining the idea of correcting the target air amount in the control apparatus for an internal combustion engine according to the first embodiment.
As shown in FIG. 12, in the control apparatus for an internal combustion engine of the first embodiment, the time required for the response speed of the actual air amount m to be the fastest, that is, the actual air amount m converges to the target value. The target air amount is corrected by the target correction device 3 from the value “before target correction” in FIG. 12 to the value “present invention (target after correction)” in FIG. .

FIG. 13 is a view showing an air amount control flowchart in the control apparatus for the internal combustion engine of the first embodiment.
In the control apparatus for an internal combustion engine of the first embodiment, as shown in FIG. 13, when air amount control is started, in step S101, target air amount acquisition means (not shown) of the control device 18 (see FIG. 5). The current target air amount (current value) is calculated and acquired based on, for example, the fuel injection amount, the engine rotation speed, the presence or absence of EGR, and the like. Next, in step S102, the target air amount acquisition unit of the control device 18 calculates and stores the previous target air amount (target air amount previous value) calculated based on, for example, the fuel injection amount, the engine speed, the presence or absence of EGR, and the like. ) Is acquired. Next, in step S103, the target air that is the difference between the current target air amount (current value) acquired in step S101 by the control device 18 and the previous target air amount (previous value) acquired in step S102. A quantity change amount is calculated.
Next, at step S104, the pressure sensor 13 (see FIG. 4) is obtained as throttle front / rear data that is upstream and downstream of the throttle valve 12 (see FIG. 4) by a throttle front / rear data acquisition means (not shown) of the control device 18. a throttle pressure before P _us detected by 4 reference), the temperature sensor 14 (and the throttle before the temperature T _us detected by the reference 4), the pressure sensor 15 (after the throttle is detected by the reference 4) pressure P _ds And is acquired.

Next, at step S105, the opening of the intake passage 11 (see FIG. 4) at the position of the throttle valve 12 (see FIG. 4) is cut by the throttle effective opening area acquisition means (not shown) of the control device 18 (see FIG. 5). The effective throttle opening area μA, which is the area, is acquired. This throttle effective opening area μA is, for example, the throttle opening detected by a throttle opening sensor (not shown) (the opening of the throttle valve 12), for example, the throttle opening previously stored in the control device 18 and the throttle effective. It is calculated based on a map, a function, etc. showing the relationship with the opening area μA.
Next, in step S106, the air amount acquisition means of the control unit 18 (not shown), the throttle before the pressure _{P us} as obtained throttle longitudinal data in step S104, the throttle before the temperature _{T us,} the throttle after the pressure _{P ds} Based on the throttle effective opening area μA acquired in step S105, the relationship shown in FIG. 11, and the following formula 2, the actual air amount (current air amount value) m passing through the throttle valve 12 is calculated and acquired. Is done.

数式１および数式２において、Ｒは気体定数、κは比熱比を示している。

In Equations 1 and 2, R represents a gas constant, and κ represents a specific heat ratio.

FIG. 10 is a diagram for explaining the actual air amount (flow rate) m, the throttle effective opening area μA, the pre-throttle pressure _Pus , the pre-throttle temperature _Tus, and the post-throttle pressure _Pds . Figure 11 is a diagram showing the ratio _P ds _{/ P us} the throttle after the pressure _{P ds} and the throttle pressure before _{P us,} the relationship between the coefficients in Equations 1 and 2 phi.

Next, in step S107, the throttle effective opening area maximum change amount ΔμA, which is the maximum change amount of the throttle effective opening area μA, is obtained by the throttle effective opening area maximum change amount acquisition means (not shown) of the control device 18 (see FIG. 5). _max is obtained. The maximum effective opening area change amount ΔμA _max of the throttle is a value (change amount) that is preliminarily adapted by the control device 18 based on the response speed such as the throttle opening, the actual air amount m, the post-throttle pressure P _{ds, and the} like. .
Next, in step S108, the maximum air amount calculating means of the control unit 18 (not shown), the throttle before the pressure _{P us} as obtained throttle longitudinal data in step S104, the throttle before the temperature _{T us,} the throttle after the pressure _{P ds} And the throttle effective opening area μA acquired in step S105, the relationship shown in FIG. 11, the throttle effective opening area maximum change amount ΔμA _max acquired in step S107, and the above formula 1, The maximum amount of air passing through (assumed maximum amount of air) “m + Δm _max ” is calculated.

Next, in step S109, the maximum air amount (air amount) calculated by the maximum air amount calculating means (not shown) in step S108 by the maximum change amount calculating means (not shown) of the control device 18 (see FIG. 5). The maximum change amount Δm _max that is the difference between the (maximum assumed value) “m + Δm _max ” and the actual air amount (current air amount value) m calculated and acquired by the air amount acquisition means (not shown) in step S106 is calculated. Is done.
Next, in step S110, it is determined whether or not the target air amount change amount calculated in step S103 is equal to or less than the maximum change amount Δm _max calculated in step S109.
In the case of No, that is, by the target air amount acquisition means (not shown) of the control device 18, the current target air amount acquired in step S101 and the previous target air amount (target air amount) acquired in step S102. When the target air amount change amount calculated in step S103 as a difference from the previous value) is larger than the maximum change amount Δm _max calculated in step S109, the process proceeds to step S112. On the other hand, if Yes, that is, if the target air amount change amount calculated in step S103 is equal to or less than the maximum change amount Δm _max calculated in step S109, the process proceeds to step S111.

In step S112, the target correction device 3 as the target air amount correction means of the control device 18 (see FIG. 5) uses the current target air amount value acquired in step S101 as the target air amount acquisition means (not shown). ) To the sum of the previous target air amount (target air amount previous value) acquired in step S102 and the maximum change amount Δm _max calculated in step S109 by the maximum change amount calculating means (not shown). The air amount control shown in FIG. 13 is terminated, and the process from step S101 is resumed after a predetermined period.
In step S111, the value of the current target air amount acquired in step S101 by the target air amount acquisition means (not shown) of the control device 18 is maintained as it is without correction, and the air amount shown in FIG. The control is terminated, and the processing from step S101 is resumed after a predetermined period.

9 applies the air amount control of the control device for the internal combustion engine of the first embodiment shown in FIG. 12, and the target air amount this time is corrected by the target correcting device 3 (see FIG. 7) in step S112 of FIG. 6 is a time chart for explaining another example.
9 (A) shows the target air amount, FIG. 9 (B) shows the throttle closing degree, FIG. 9 (C) shows the actual air amount m, and FIG. 9 (D) shows D 9 shows the post-throttle pressure (post-throttle pressure) _Pds , FIG. 9 (E) shows the D pre-throttle pressure (pre-throttle pressure) _Pus , and FIG. 9 (F) shows the D pre-throttle temperature (pre-throttle). (Temperature) _Tus is shown, and FIG. 9G shows the opening of the EGR valve 17 (see FIG. 4).

  In the example shown in FIG. 9, as shown in FIG. 9G, the EGR valve 17 (see FIG. 4) is fully closed and the EGR cut is executed, so that the target air amount (see FIG. 9A) is obtained. ) Changes suddenly.

  When the air amount control of the control apparatus for an internal combustion engine according to the first embodiment of the present invention shown in FIG. 12 is not executed, the EGR cut is executed as shown in FIG. Along with EGR present → none), the target air amount increases rapidly. Along with this, as shown in FIG. 9B, “Before correction”, the throttle closing degree rapidly decreases (that is, the throttle opening increases rapidly). As a result, as indicated by “before correction” in FIG. 9C, the actual air amount m overshoots, and it takes a long time for the actual air amount m to converge to the target value.

  On the other hand, when the air amount control of the control device for the internal combustion engine according to the first embodiment of the present invention shown in FIG. 12 is executed, “the present invention (after correction)” is shown in FIG. In addition, although the target air amount temporarily increases suddenly with the execution of EGR cut (with EGR), the target air amount is moderated because the target air amount is corrected in step S112 in FIG. To increase. Accordingly, as shown in FIG. 9B as “present invention (after correction)”, the decrease in the throttle closing degree becomes more gradual than that before “before correction” (that is, the increase in the throttle opening becomes It will be more gradual than “Before revision”). As a result, as indicated by “present invention (after correction)” in FIG. 9C, the overshoot of the actual air amount m can be suppressed as compared with “before correction”, and the actual air amount m It is also possible to shorten the time required for the value to converge to the target value.

Further, in the example shown in FIG. 9, the influence of the high-pressure EGR gas is cut off by executing the EGR cut (EGR present → no), and as a result, as shown in FIG. Post pressure) _Pds changes suddenly. As shown in FIG. 9 (E), the change in D pre-throttle pressure (pre-throttle pressure) _Pus is small. Further, as shown in FIG. 9F, the pre-slot temperature (pre-throttle temperature) _Tus does not change.

As described above, in the control device for the internal combustion engine of the first embodiment, as shown in FIG. 12, the target air amount change amount, which is the difference between the current target air amount and the previous target air amount, is the throttle valve. 12 (see FIG. 4), when the amount of change m is greater than the maximum change amount Δm _max , the current target air amount is the sum of the previous target air amount and the maximum change amount Δm _max in step S112. Is corrected to the value of. Specifically, the maximum change amount Δm _max is based on the throttle front-rear data (pre-throttle pressure P _us , pre-throttle temperature T _us , post-throttle pressure P _ds ) and the throttle effective opening area maximum change amount ΔμA _max .
In other words, in the control apparatus for an internal combustion engine according to the first embodiment, when the target air amount changes suddenly, data before and after the throttle (pre-throttle pressure _Pus , pre-throttle temperature _Tus , post-throttle pressure _Pds ) and throttle Regardless of the maximum effective opening area change amount ΔμA _max , the air amount control is not executed based on the target air amount calculated according to, for example, the fuel injection amount, the engine rotation speed, the presence or absence of EGR, etc. in step S112 the 12 throttle longitudinal data (throttle pressure before _{P us,} throttle temperature before _{T us,} the throttle pressure after _{P ds)} target air amount based on the throttle effective opening area maximum variation Derutamyuei _max is corrected, precision Air amount control is executed. Therefore, the throttle longitudinal data when the target air amount is suddenly changed (throttle pressure before P _us, throttle temperature before T _us, the throttle pressure after P _ds) is independent air quantity control and and the throttle effective opening area maximum variation Derutamyuei _max The overshoot of the actual air amount m when the target air amount changes suddenly can be suppressed as compared with the case where it is executed.
Further, in the control device for the internal combustion engine of the first embodiment, the guard value is not set to the change speed of the target throttle opening as in the intake air amount control device for the internal combustion engine described in Patent Document 1, Air amount control is executed. Therefore, the time required for the actual air amount m to converge to the target value can be shortened as compared with the intake air amount control device for the internal combustion engine described in Patent Document 1.
That is, in the control apparatus for an internal combustion engine according to the first embodiment, when the target air amount suddenly changes, the time required for the actual air amount m to converge to the target value while suppressing the overshoot of the actual air amount m. Can be shortened.

Hereinafter, embodiments of the invention related to the present invention will be described. The embodiment of the invention related to the present invention can be applied to an engine system having the configuration shown in FIG. 4, for example.
FIG. 14 is a diagram showing an application example (first-order lag system) of a delay element with respect to the target air amount. In the embodiment of the invention related to the present invention, as shown in FIG. 14, a delay element is provided with respect to the target air amount. In the example shown in FIG. 14, the first-order lag element is applied, but in other examples, a second-order or higher-order lag element can also be applied.
FIG. 15 is a diagram for explaining the idea of correcting the target air amount in the embodiment of the invention related to the present invention. In the embodiment of the invention related to the present invention, as shown by “present invention (target after correction)” in FIG. 15, the target air amount is corrected on the assumption that there is a delay (inertia) in the air amount. .
FIG. 16 is a view showing an air amount control flowchart in the embodiment of the invention related to the present invention. Specifically, FIG. 16 shows an example in the case of a first-order lag system.
In the embodiment of the invention related to the present invention, as shown in FIG. 16, when the air amount control is started, the target air amount (see FIG. 14) is acquired in step S201. Next, in step S202, a time constant (delay element) (see FIG. 14) is acquired. Next, in step S203, the corrected target air amount (corrected target air amount) (see FIG. 14) is calculated according to the example shown in FIG.

  In the second embodiment, the above-described first embodiment and each example can be appropriately combined.

DESCRIPTION OF SYMBOLS 1 Throttle model 2 Feedback control device 3 Target correction device 11 Intake passage 12 Throttle valve 13 Pressure sensor 14 Temperature sensor 15 Pressure sensor 16 EGR passage 17 EGR valve 18 Control device

Claims (1)

An internal combustion engine body;
An intake passage connected to the internal combustion engine body;
In a control device applied to an internal combustion engine comprising a throttle valve disposed in the intake passage,
Target air quantity acquisition means;
Throttle front-rear data acquisition means for acquiring the pressure and temperature upstream of the throttle valve and the pressure downstream of the throttle valve;
Throttle effective opening area acquisition means for acquiring a throttle effective opening area that is an opening cross-sectional area of the intake passage at the position of the throttle valve;
An air amount acquisition means for acquiring the amount of air passing through the throttle valve;
A throttle effective opening area maximum change amount acquisition means for acquiring a throttle effective opening area maximum change amount which is a maximum change amount of the throttle effective opening area;
Maximum air for calculating the maximum amount of air passing through the throttle valve based on the pressure and temperature on the upstream side of the throttle valve, the pressure on the downstream side of the throttle valve, the throttle effective opening area, and the maximum change amount of the throttle effective opening area A quantity calculating means;
Maximum change amount calculating means for calculating a maximum change amount which is a difference between the maximum air amount calculated by the maximum air amount calculating means and the air amount acquired by the air amount acquiring means;
A target air amount correcting means is provided in the control device;
When the target air amount change amount, which is the difference between the current target air amount acquired by the target air amount acquisition means and the previous target air amount, is larger than the maximum change amount calculated by the maximum change amount calculating means. ,
The target air amount correction means calculates the value of the current target air amount as a sum of the previous target air amount acquired by the target air amount acquisition means and the maximum change amount calculated by the maximum change amount calculation means. A control apparatus for an internal combustion engine, wherein

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