JPH1182102A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a correct air-fuel ratio at all times in a control device for an internal combustion engine of an air quantity precedent fuel supply quantity follow-up control system provided with an electronically controlled throttle valve device. SOLUTION: This control device for an internal combustion engine of an air quantity precedent fuel follow-up control system controls throttle valve opening and fuel supply quantity according to the operating position of an accelerator pedal, estimates throttle valve opening TA' after the intake time of fuel into a cylinder at the time of computing the fuel injection quantity, computes the estimated intake air quantity GNVLV at this time from the estimated throttle valve opening TA' and the present engine speed Ne, and determines the fuel injection quantity on the basis of the computed estimated intake air quantity GNVLV. At the time of computing the fuel injection quantity, the engine speed NE at this time is estimated from the past transition of engine speed Ne simultaneously with the estimation of the throttle valve opening TA', and the estimated intake air quantity GNVLV at this time is computed from the estimated throttle valve opening TA' and the estimated engine speed NE. The fuel injection quantity is determined on the basis of the estimated intake air quantity GNVLV.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an internal combustion engine, and more particularly to an internal combustion engine equipped with an electronically controlled throttle valve for controlling an air-fuel ratio by leading an intake air amount and following a fuel supply amount. The present invention relates to a control device for an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, in an internal combustion engine of an electronically controlled fuel injection control system, an air-fuel ratio is adjusted by measuring an intake air amount and calculating a corresponding fuel injection amount. This air-fuel ratio adjustment method is based on the idea that the amount of intake air is determined according to the amount of depression of the accelerator pedal. For this reason, when the change of the intake air amount is large, such as when the engine is accelerating or decelerating, there is a problem that a measurement error of the intake air amount occurs in the computer that controls the engine.

Therefore, an electronically controlled throttle valve that controls the throttle valve using an electric actuator in accordance with the amount of depression of an accelerator pedal is used to determine the amount of fuel to be injected first, and to follow the amount of intake air later. There is an engine control device of a fuel supply advance and air amount follow-up control system (see Japanese Patent Publication No. 7-33781). Tokuhei 7-3378
In the engine control device described in Japanese Patent Application Publication No. 1-2003, a fuel supply amount advance and air amount follow-up control type engine in which a fuel supply amount and a throttle valve opening are adjusted in accordance with an operation position of an accelerator pedal is provided. For the control of the amount, the time until fuel is actually sucked into the cylinder is set as a predetermined delay time in accordance with the operation position of the accelerator pedal and the rotation speed of the engine, and the predetermined time is A technique for setting a delay time is disclosed.

[0004] By setting the delay time, the time until the injected fuel is actually sucked into the cylinder is taken into consideration, and the fuel amount and the intake air amount in the cylinder are precisely controlled.

[0005]

However, in the engine control device described in Japanese Patent Publication No. 7-33781, since the operating conditions of the engine frequently change in practice, the delay calculated as described above is used. The time is a time that fluctuates due to changes in the engine speed and the fuel injection amount, and particularly when the accelerator pedal is rapidly operated, the amount of the fluctuation is excessive, so that the throttle valve may not be able to respond.
It is difficult to control the throttle valve opening to a target value by applying the throttle valve opening control every time, and there has been a problem that an accurate air-fuel ratio cannot always be obtained.

Accordingly, the present invention provides an electronically controlled throttle valve device which employs an air amount advance and fuel supply amount follow-up control system in which an intake air amount is determined in advance and a fuel supply amount is made to follow this to control an air-fuel ratio. In an internal combustion engine equipped with a throttle valve, by accurately grasping the influence of the change in the throttle valve opening on the change in the intake air amount, and also considering the influence on the intake air amount due to the change in the engine speed, an accurate An object of the present invention is to provide a control device for an internal combustion engine that can obtain an air-fuel ratio.

[0007]

According to a first aspect of the present invention, which achieves the above object, there is provided an air-advanced fuel follow-up which controls a throttle valve opening and a fuel supply amount in accordance with an operation position of an accelerator pedal. A control device for an internal combustion engine of a control system, which estimates a throttle valve opening corresponding to a time after fuel is actually sucked into a cylinder when calculating a fuel injection amount, and estimates the estimated throttle valve opening and a current engine rotation. The control device for the internal combustion engine calculates the estimated intake air amount at this time from the number and determines the fuel injection amount based on the calculated estimated intake air amount. The engine speed at this time is estimated from the past change in the engine speed, the estimated intake air amount at this time is calculated based on the estimated throttle valve opening and the estimated engine speed, and fuel is calculated based on the calculated estimated intake air amount. It is characterized in that so as to determine the injection quantity.

FIG. 1 shows the basic configuration of the first invention. A control device for an internal combustion engine according to a first aspect of the present invention is a control device for an internal combustion engine of an air amount advanced fuel follow-up control system which controls a throttle valve opening and a fuel supply amount according to an operation position of an accelerator pedal. A throttle valve opening target value calculating means for calculating a throttle valve opening target value corresponding to an operation position of an accelerator pedal; and a throttle valve opening target value for storing the throttle valve opening target value for a predetermined time. A throttle valve opening for calculating a throttle valve opening estimated value from the calculated throttle valve opening target value in consideration of a throttle valve response delay and a change in the stored throttle valve opening target value. Means for calculating an estimated value, means for storing the estimated value of the throttle valve opening for storing the estimated value of the throttle valve opening for a predetermined time, and means for storing the stored target value of the throttle valve opening after a predetermined time Means for outputting a throttle valve opening control value which is output as a rottle valve opening control value, means for driving a throttle valve for opening and closing the throttle valve in accordance with the throttle valve opening control value, and detecting and storing the engine speed; From the detected engine speed, storage means, the intake valve closing time calculating means for calculating the intake valve closing time of the fuel injection cylinder according to the operating state of the engine, and from the transition of the stored engine speed, Means for estimating the engine speed at the time of closing the intake valve for estimating the engine speed at the time of closing the intake valve of the fuel injection cylinder, the stored estimated value of the throttle valve opening, and the closing time of the intake valve of the fuel injection cylinder Means for calculating the estimated intake air amount at the intake valve closing time at the current time from the estimated engine speed, and the estimated intake air amount at the current time; A calculation unit of the current intake air amount to calculate the definitive amount of intake air,
An intake air amount detecting means provided in an intake passage of the internal combustion engine for detecting an actual intake air amount, and a deviation obtained by subtracting an intake air amount at a current time from an estimated intake air amount at an intake valve closing time. An estimated intake air amount correction means for calculating a correction value of the estimated intake air amount at the intake valve closing time of the fuel injection cylinder by adding to the actual intake air amount at the current time; and a corrected future estimation The fuel supply system further includes a fuel supply amount calculating unit that calculates a fuel supply amount from the intake air amount and the target air-fuel ratio, and a fuel supply unit that supplies the calculated fuel supply amount.

A second aspect of the present invention that achieves the above object is an internal combustion engine of an air amount advanced fuel follow-up control system which controls a throttle valve opening and a fuel supply amount in accordance with an operation position of an accelerator pedal. A control device for an engine, which estimates a throttle valve opening corresponding to a time after fuel is actually sucked into a cylinder at the time of calculating a fuel injection amount, and calculates the throttle valve opening from the estimated throttle valve opening and the current engine speed. The estimated intake air amount at the time is calculated, and the calculated estimated intake air amount is corrected by the current intake air amount and the current estimated intake air amount to calculate a correction value of the estimated intake air amount, and the corrected estimated intake air amount is corrected. In the control device for the internal combustion engine, which determines the fuel injection amount according to, the estimated intake air amount is stored and used as the current estimated intake air amount used when calculating the correction value of the estimated intake air amount. Is characterized in that out fuel actually uses the estimated intake air amount calculated before the same time as the time that is taken into the cylinder.

FIG. 2 shows the basic configuration of the second invention. A control device for an internal combustion engine according to a second aspect of the present invention is a control device for an internal combustion engine of an air amount leading fuel follow-up control system which controls a throttle valve opening and a fuel supply amount according to an operation position of an accelerator pedal. A throttle valve opening target value calculating means for calculating a throttle valve opening target value corresponding to an operation position of an accelerator pedal; and a throttle valve opening target value for storing the throttle valve opening target value for a predetermined time. A throttle valve opening for calculating a throttle valve opening estimated value from the calculated throttle valve opening target value in consideration of a throttle valve response delay and a change in the stored throttle valve opening target value. Means for calculating an estimated value, means for storing the estimated value of the throttle valve opening for storing the estimated value of the throttle valve opening for a predetermined time, and means for storing the stored target value of the throttle valve opening after a predetermined time Means for outputting a throttle valve opening control value which is output as a throttle valve opening control value; driving means for a throttle valve which opens and closes a throttle valve according to the throttle valve opening control value; and fuel injection according to the operating state of the engine Calculating means for calculating the closing time of the intake valve of the cylinder, calculating means for calculating the estimated closing air amount in the future from the estimated value of the throttle valve opening, and calculating the calculated estimated intake air Means for storing an estimated amount of intake air for storing the amount of air; means for detecting the amount of intake air provided in the intake passage of the internal combustion engine for detecting the actual amount of intake air; The current estimated intake air amount reading means for reading out the estimated intake air amount corresponding to the current time as the intake air amount at the current time, and when the intake valve is closed among the stored estimated intake air amounts. The estimated intake air amount at the time of closing the intake valve of the fuel injection cylinder is calculated by adding the deviation obtained by subtracting the intake air amount at the current time from the estimated intake air amount at the current time to the actual intake air amount at the current time. Means for correcting the estimated intake air amount to be calculated, means for calculating the fuel supply amount from the corrected future estimated intake air amount and the target air-fuel ratio, and supplying the fuel of the calculated fuel supply amount And a fuel supply means.

According to the control device for an internal combustion engine of the present invention, the future change in the throttle opening is estimated and stored, and when calculating the fuel injection amount at the present time, after the time when the fuel is actually supplied to the cylinder, A corresponding estimated throttle opening value is calculated, an estimated intake air amount corresponding to the estimated throttle opening value is calculated, and when the fuel amount is injected according to the change in the intake air amount, the throttle valve opening value is calculated. Is calculated in consideration of a future change in the engine speed, so that a more accurate required injection amount can be calculated.

[0012]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 3 schematically shows an electronically controlled fuel injection type multi-cylinder internal combustion engine 1 including a control device according to an embodiment of the present invention. In FIG. 3, an air flow meter 16 and a throttle valve 3 are provided in this order downstream of an air cleaner (not shown) in an intake passage 2 of the internal combustion engine 1.

The air flow meter 16 has a measuring plate 17, and intake air is supplied to the measuring plate 1.
7 is pushed open and flows into the throttle valve 3 side. The opening of the measuring plate 17 is determined by the amount of intake air.
A potentiometer (not shown) is connected to the measuring plate 17, and the opening of the measuring plate 17, that is, the amount of intake air is converted into a voltage value by the potentiometer and output from the air flow meter 16.

An actuator 4 for driving the throttle valve 3 is provided at one end of a shaft of the throttle valve 3, and a throttle opening sensor 5 for detecting the opening of the throttle valve 3 is provided at the other end. ing. That is, the throttle valve 3 of this embodiment is an electronically controlled throttle that is opened and closed by the actuator 4. A surge tank 6 is provided in the intake passage 2 on the downstream side of the throttle valve 3, and a pressure sensor 7 for detecting intake pressure is provided in the surge tank 6.
Is provided. Further, on the downstream side of the surge tank 6, a fuel injection valve 8 for supplying pressurized fuel from a fuel supply system to an intake port is provided for each cylinder. The output from the air flow meter 16, the output from the throttle opening sensor 5, and the output from the pressure sensor 7 are input to an ECU (engine control unit) 10 incorporating a microcomputer.

In the cooling water passage 9 of the cylinder block of the internal combustion engine 1, a water temperature sensor 11 for detecting the temperature of the cooling water is provided. The water temperature sensor 11 generates an analog voltage electric signal according to the temperature of the cooling water. The exhaust passage 12 contains three harmful components HC and C in the exhaust gas.
A three-way catalytic converter (not shown) for purifying O and NOx at the same time is provided. An O ₂ sensor 13 which is a kind of air-fuel ratio sensor is provided in an exhaust passage 12 on the upstream side of the catalytic converter. I have. The O ₂ sensor 13 generates an electric signal according to the concentration of the oxygen component in the exhaust gas. The outputs of the water temperature sensor 11 and the O ₂ sensor 13 are
Is input to

The ECU 10 further includes an accelerator depression amount signal from an accelerator depression amount sensor 15 attached to the accelerator pedal 14 and an engine speed N from a crank angle sensor attached to a distributor (not shown).
e is input. In the above configuration, when a key switch (not shown) is turned on, the ECU 10 is energized to start a program, an output from each sensor is taken in, an actuator 4 for opening and closing the throttle valve 3, a fuel injection valve 8, Alternatively, control of other actuators is started. The ECU 10 includes an A / D converter that converts analog signals from various sensors into digital signals.
Input / output interface 1 for input / output of digital signals from various sensors and signals for driving each actuator
01, CPU 102 for performing arithmetic processing, ROM 103 and R
A memory such as an AM 104, a clock 105, and the like are provided, and these are interconnected by a bus 106.
Since the configuration of the ECU 10 is publicly known, further description is omitted.

Here, an example of the control of the present invention in the control device for an internal combustion engine configured as shown in FIG. 3 will be described. In this embodiment, a target opening degree (opening target value) of the throttle valve in the electronically controlled throttle with respect to the operation amount of the accelerator pedal is stored for a predetermined time with respect to the current operation amount of the accelerator pedal by the driver. The output is suspended, and after a predetermined time, this opening target value is output to the actuator of the electronic control throttle as the opening control value of the throttle valve. Therefore, the current operation amount of the accelerator pedal is intentionally delayed by a very short predetermined time and transmitted to the actuator of the electronic control throttle,
The throttle valve follows the operation amount of the accelerator pedal with a delay of the predetermined time.

On the other hand, the actuator 4 for driving the throttle valve 3 has a response delay with respect to the control value of the throttle valve opening. That is, even if the depression amount of the accelerator pedal (the target value of the throttle valve opening) changes linearly, the estimated opening of the throttle valve follows the delay. This will be described with reference to FIG. In FIG. 4, the time when the fuel injection amount of the first cylinder # 1 of the engine is calculated is the current time to, the time for delaying the target value of the throttle valve opening is D, and the intake valve of the first cylinder # 1 of the engine is D. Is T. At the current time to, operating state parameters such as the intake air amount GN from the air flow meter 16, the engine speed Ne of the internal combustion engine 1, the intake pressure P, and the accelerator pedal depression amount (operating position) are taken into the ECU 10 from various sensors. The target value TA of the throttle valve opening and the estimated throttle valve opening (estimated value of the throttle valve opening) TA 'according to the current operation position of the accelerator pedal are calculated, and the operating state of the engine is calculated. From this, the end point of the intake stroke of the first cylinder # 1, that is, the closing time T of the intake valve is calculated. The calculated throttle valve opening target value TA and estimated opening TA ′ are stored in the RAM 1 of the ECU 10.
04 is stored.

Further, at the current time to, the valve closing time T
Is calculated, a time tn that is a predetermined delay time D before the time T is calculated, and the estimated opening TA ′ of the throttle valve at the time tn is calculated. The estimated opening TA ′ of the throttle valve at time tn is the estimated opening of the throttle valve at time T. Then, when the estimated opening degree TA 'of the throttle valve at the closing time T of the intake valve is known, the fuel injection amount can be calculated from the intake air amount corresponding thereto. The second cylinder # 2 at time t1 also
The fuel injection amount at the closing time T1 of the intake valve of the second cylinder # 2 can be calculated in the same manner as the cylinder # 1.

On the other hand, while the target value TA of the throttle valve opening linearly changes in accordance with the amount of depression of the accelerator pedal, the throttle valve follows with a delay with respect to the target value TA. Needs to be estimated to be smaller than the target value TA of the throttle valve opening. Accordingly, the estimated opening degree TA 'of the throttle valve at the intake valve closing time T of the fuel injection cylinder (first cylinder # 1 in FIG. 4) is also smaller than the target value TA of the throttle valve opening degree. Then, the actuator 4 drives the throttle valve so that the opening degree of the throttle valve follows the estimated opening degree TA 'given to the actuator 4 at time T without delay.

By the way, in the air-fuel ratio control method of the air amount advance and fuel follow-up method, how the throttle valve 3 moves from now on by the amount that the follow-up of the throttle valve 3 with respect to the operation amount of the accelerator pedal is intentionally delayed. Can be grasped, and how the intake air amount changes accordingly can be obtained by calculation. As a result, the intake air amount can be determined from the opening degree of the throttle valve 3 at the closing time of the intake valve of the next fuel injection cylinder, and the fuel injection amount corresponding to this intake air amount is changed to the intake valve of the next fuel injection cylinder. It can be calculated at the time when the closing time of the intake valve is obtained, and the calculated fuel injection amount is detected at a predetermined timing before the closing time of the intake valve, that is, at a predetermined crank angle position. You can inject.

In this case, the intentional delay time is set longer than the time from the present to the time when the intake valve of the next fuel injection cylinder closes. This intentional delay time is
According to the rotational speed Ne of the internal combustion engine 1, a value that is longer than the time from the time when the fuel injection amount is calculated to the time when the intake valve of the next fuel injection cylinder closes is calculated in advance, and the map is calculated. May be stored in the memory of the ECU 10 and read out according to the engine speed Ne.

Here, the intake air amount calculated from the opening degree of the throttle valve 3 at the closing time of the intake valve of the next fuel injection cylinder will be described. First, the calculation procedure of the intake air amount at the closing time of the intake valve of the fuel injection cylinder devised so far by the present inventors was as follows. (1) First, a change in the throttle valve opening in the future within a certain period of time is estimated, and this is stored in a storage device as an estimated value TA ′ of the throttle valve opening, and at the current time when the fuel injection amount is calculated. An estimated value TA 'of the throttle valve opening corresponding to a time after the fuel is actually sucked into the cylinder is read from the storage device, and the estimated intake air is obtained from the estimated value TA' of the throttle valve opening and the current engine speed Ne. Quantity GNVLV
[GNVLV = f (TA ', Ne)].

(2) Next, in order to cancel a deviation that constantly exists between the estimated intake air amount GNVLV and the actual intake air amount GN (measured by an air flow meter),
Current actual throttle opening TA and current engine speed N
e to estimate the current intake air amount GNBSE [GN
BSE = f (TA, Ne)]. (3) Then, the estimated intake air amount GNVLV calculated in (1)
Is subtracted from the current intake air amount GNBSE to obtain the intake air amount GNFW at the closing time of the intake valve of the fuel injection cylinder.
D from the current intake air amount GNBSE (GNVLV
-GNBSE).

(4) This difference (GNVLV-GNBSE)
Is added to the current actual intake air amount GN. Than this,
Intake air amount GNF at the closing time of the intake valve of the fuel injection cylinder
The equation for estimating WD is as follows. GNFWD = (GNVLV−GNBSE) + GN However, in this calculation procedure, when calculating the estimated intake air amount GNVLV in (1), the current engine speed Ne is used.
Since the intake air amount is greatly affected by the engine speed, the estimated intake air amount GNVLV calculated in (1) is calculated based on the current engine speed Ne and the engine speed at the intake valve closing time. Due to the error with the number NE, it was not always accurate.

Therefore, in the first embodiment of the present invention, (1)
Intake air amount GNVLV at the closing time of the intake valve at
The current value is not used as the engine speed used to calculate the engine speed, but the estimated engine speed at the closing time of the intake valve is used. There are the following two methods for calculating the estimated value of the engine speed at the closing time of the intake valve. (1-A) First, every time the engine speed Ne is detected, its value is stored in a storage device, the transition of the engine speed Ne up to the present is grasped, and it is assumed that this transition continues. A change in the engine speed Ne from the current time to the closing time of the intake valve is calculated.

(1-B) Calculate the torque generated in the engine from the amount of air already inhaled, and calculate the engine speed Ne from the vehicle operating state information such as the engine cooling water temperature, transmission gear shift position, and vehicle speed. Is calculated, and a change in the engine speed Ne from the present time to the intake valve closing time is calculated based on the change amount. In the first embodiment, the estimated intake air amount GNVLV is obtained from the engine speed NE at the intake valve closing time estimated in this manner and the estimated value TA 'of the throttle valve opening.
[GNVLV = f (TA ', NE)]. (2)
The steps (3) to (3) are the same as the procedure for calculating the intake air amount at the closing time of the intake valve of the fuel injection cylinder devised by the present inventors.

As in the first embodiment, when calculating the estimated intake air amount GNVLV at the closing time of the intake valve, the estimated engine speed N obtained from the transition of the engine speed Ne so far is used.
By using E, the value of the estimated intake air amount GNFWD corrected at the closing time of the intake valve of the fuel injection cylinder becomes more accurate, and an accurate required injection amount can be calculated.

In the second embodiment of the present invention, the aforementioned
The current intake air amount GNBSE in (3) is estimated in the following procedure. (1-2) First, a change in the throttle valve opening in the future within a certain time is estimated, and this is stored in a storage device as an estimated value TA 'of the throttle valve opening, and the estimated value TA of the throttle valve opening is stored. ′, The future estimated intake air amount GNVLV is calculated and stored in the storage device.

(2-2) Stored past estimated intake air amount G
Estimated intake air amount GN corresponding to the current time in NVLV
VLVP is read, and the read value is set as the intake air amount GNBSE at the current time. (3-2) And the estimated intake air amount GNV stored in (1-2)
Among the LVs, the one corresponding to the intake valve closing time is read out, and the estimated intake air amount GN corresponding to the intake valve closing time is read out.
Current intake air amount GNBS calculated from VLV in (2-2)
E is subtracted to calculate a difference (GNVLV-GNBSE) between the intake air amount GNFWD at the closing time of the intake valve of the fuel injection cylinder and the current intake air amount GNBSE.

(4-2) This difference (GNVLV-GNBS)
E) is added to the current actual intake air amount GN to obtain a corrected estimated intake air amount GNFWD at the closing time of the intake valve of the fuel injection cylinder. In the second embodiment, the procedures (1-2) to (3-2) are different from the procedure proposed by the present inventor. As a result, the future estimated intake air amount GNVLV in (3-2) is calculated based on the current engine speed (equivalent to NE), and the intake air amount GN at the current time is calculated.
The BSE is calculated on the basis of the estimated future intake air amount GNVLV (corresponding to the present in the past future) calculated based on the engine speed Ne at that time in the past, so the estimated future intake air in the present is estimated. That is, the amount GNVLV is calculated in consideration of the transition of the engine speed Ne.

An example of the control procedure according to the first embodiment of the present invention will be described with reference to the flowcharts shown in FIGS. 5 and 6 are executed at predetermined time intervals, for example, at every 8 ms. In step 501 of FIG. 5, first, the operation state of the internal combustion engine 1 is detected. The detection of the operating state can be performed by inputting operating state parameters such as the engine speed Ne, the intake pressure P, and the amount of depression of the accelerator pedal (operating position) into the ECU 10 from various sensors. In this step 501, at least the detected engine speed Ne is stored in the RAM 104 of the ECU 10. In the following step 502, the operation position of the accelerator pedal is read, and in the next step 503, the target value TA of the throttle valve opening corresponding to the operation position of the accelerator pedal is calculated.
4 is stored.

In the following step 504, the delay of the throttle valve and R
The estimated opening degree TA 'is calculated in consideration of the transition of the target value TA of the throttle valve opening degree in the past predetermined period stored in the AM 104, and is stored in the RAM 104 of the ECU 10. Then, in step 505, the intake air amount GNBSE at the current time when the fuel injection amount is calculated from the target opening TA of the throttle valve is calculated. Next step 50
In step 6, the intake valve closing time T of the next fuel injection cylinder is calculated from the operating state of the engine including the engine speed Ne detected in step 501.

Then, in the following step 507, an estimation at the time of closing the intake valve of the fuel injection cylinder is made from the transition of the engine speed Ne stored in step 501 and the intake valve closing time T calculated in step 506. The engine speed NE is calculated. Thereafter, in step 508, the estimated intake air amount GNVLV at the intake valve closing time T is calculated from the stored estimated opening degree TA 'of the throttle valve and the estimated engine speed NE.

In the next step 509, the current intake air amount GN is read from the air flow meter 16, and in step 510, the current intake air amount GNBSE calculated in step 505, and the intake valve closing calculated in step 508. The estimated intake air amount GNVLV at the valve time T and the current intake air amount G read at step 509
N, the correction value GNF of the estimated intake air amount GNVLV
WD is calculated from the following equation.

GNFWD = (GNVLV−GNBSE) + GN When the estimated intake air amount GNFWD corrected in this way is calculated, in step 511, the fuel injection amount according to the estimated intake air amount GNFWD is calculated. Although not described, the fuel injection amount is calculated based on the intake air amount obtained from the throttle valve opening so that the target air-fuel ratio is obtained in another routine according to the operating state of the engine.

In the next step 512, the calculated intake valve closing time T and the fuel injection amount corresponding to the intake valve closing time T are stored in the RAM 104 in the ECU 10, and this routine ends. On the other hand, in the injection control routine shown in FIG. 6, in step 601, it is determined at predetermined time intervals whether or not the engine is at a predetermined crank angle position representing a predetermined timing before the closing time of the intake valve. When it is at the predetermined crank angle position, the routine proceeds to step 602, where the fuel injection amount corresponding to the predetermined crank angle position is determined by the RA10 of the ECU 10.
The fuel injection amount is read from M104, and the fuel injection amount is injected from the injection valve 8, and the routine proceeds to step 603. Step 6
If it is not 01 and it is not the predetermined crank angle position, the routine proceeds to step 603 as it is.

In step 603, the throttle valve opening target value TA stored in the RAM 104 of the ECU 10 is read out a predetermined time D before the current time, and this is output to the actuator 4 as a throttle valve opening control value. Is done. The throttle valve 3 is opened and closed by the actuator 4 based on the control value of the throttle valve opening.
Next, an example of a control procedure according to the second embodiment of the present invention will be described with reference to a flowchart shown in FIG. The routine of FIG. 7 is also executed at predetermined time intervals, for example, at every 8 ms. In the control procedure of the second embodiment, the same control procedures as in the first embodiment will be described with the same step numbers.

In step 501 'of FIG. 7, the operation state of the internal combustion engine 1 is detected. The detection of the operating state can be performed by inputting operating state parameters such as the engine speed Ne, the intake pressure P, and the amount of depression of the accelerator pedal (operating position) into the ECU 10 from various sensors.
In the following step 502, the operation position of the accelerator pedal is read. In the next step 503, the target value TA of the throttle valve opening corresponding to the operation position of the accelerator pedal is calculated and stored in the RAM 104 of the ECU 10.

In the following step 504, the delay of the throttle valve and R
The estimated opening degree TA 'is calculated in consideration of the transition of the target value TA of the throttle valve opening degree in the past predetermined period stored in the AM 104, and is stored in the RAM 104 of the ECU 10. Second
In this embodiment, step 505 of the first embodiment is omitted, and the process proceeds to step 506. In step 506, the intake valve closing time T of the next fuel injection cylinder is calculated from the operating state of the engine including the engine speed Ne detected in step 501. When step 506 ends, the process proceeds to step 701.

In the second embodiment, in step 701, the engine speed Ne detected in step 501 'and the estimated throttle valve opening T stored in step 504 are stored.
A ′, and the intake valve closing time T calculated in step 506, the estimated intake air amount GNVLV at the intake valve closing time T is calculated, and the calculated estimated intake air amount G
NVLV determines in step 702 that the RAM of the ECU 10
104.

In the following step 703, the R
Of the estimated intake air amount GNVLV calculated in the past stored in the AM 104, the estimated intake air preceding the time (T-to) from the current time to to the closing time T of the intake valve of the injection cylinder by the same time. The air amount GNVLVP is read, and the estimated intake air amount GNVLVP is used as the current estimated intake air amount GNBSE.

In the first embodiment, the estimated intake air amount GNBSE at the current time to is calculated based on the current engine speed Ne, and the estimated intake air amount GNVLV at the intake valve closing time T is calculated based on the intake valve closing time T. The engine speed NE at T was calculated by estimating from the past changes in the engine speed, and the correction value GNFWD of the estimated intake air amount was calculated. On the other hand, in the second embodiment, the estimated intake air amount GNVLV at the intake valve closing time T is calculated based on the current engine speed Ne, but the estimated intake air amount GNBSE at the current time to includes the current time The estimated intake air amount GNVLV calculated in the past for a time corresponding to the time from to to the intake valve closing time T is used. Therefore,
In the second embodiment, as in the first embodiment, the estimated intake air amount GNVLV at the intake valve closing time T is the same as that calculated based on the estimated engine speed NE at the intake valve closing time T. Will be.

At step 509, the current intake air amount GN is read from the air flow meter 16. At step 510, the current intake air amount GNBSE calculated at step 703 and the intake valve closing calculated at step 701 are performed. The estimated intake air amount GNVLV at time T, and
Using the current intake air amount GN read in step 509, the correction value GNFWD of the estimated intake air amount GNVLV is used.
Is calculated from the following equation.

GNFWD = (GNVLV−GNBSE) + GN When the estimated intake air amount GNFWD corrected in this way is calculated, the fuel injection amount corresponding to the estimated intake air amount GNFWD is calculated in step 511, and step 512 Then, the calculated intake valve closing time T and the fuel injection amount corresponding to the intake valve closing time T are calculated by the ECU 10.
Then, this routine ends.

The injection control routine executed thereafter is as follows:
This is exactly the same as the injection control routine described with reference to FIG. As described above, in the control devices for the internal combustion engines of the first and second embodiments described above, the air amount advance and fuel supply amount follow-up control methods are adopted, and the internal control in which the intake air amount is controlled by the electronically controlled throttle valve device. In the engine, the estimated intake air amount when the intake valve is closed is taken into account in calculating the estimated intake air amount when the intake valve is closed, so that the value of the estimated intake air amount when the intake valve is closed is more accurate. Become.

[0047]

As described above, according to the internal combustion engine control devices of the first and second aspects of the present invention, the transition of the throttle opening in the future is estimated and stored, and the future change of the throttle opening at the current time is estimated. When calculating the fuel injection amount, an estimated throttle opening value corresponding to a time after fuel is actually supplied to the cylinder is calculated, an estimated intake air amount corresponding to the estimated throttle opening value is calculated, and the intake air amount is calculated. When the injection of the fuel amount is executed according to the change, the future estimated intake air amount estimated according to the throttle valve opening value is calculated in consideration of the change in the future engine speed, so that a more accurate There is an effect that the required injection amount can be calculated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a configuration of a control device for an internal combustion engine according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a configuration of a control device for an internal combustion engine according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing an entire configuration of an embodiment of a control device for an internal combustion engine of the present invention.

FIG. 4 is an explanatory diagram showing the relationship between the accelerator opening, the throttle valve opening, and the closing time of the intake valve with the passage of time in the control of the present invention.

FIG. 5 is a flowchart illustrating an example of a control procedure of the first embodiment in the control device for the internal combustion engine of the present invention.

FIG. 6 is a flowchart showing an injection control procedure.

FIG. 7 is a flowchart showing an example of a control procedure of a second embodiment in the control device for an internal combustion engine of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Intake passage 3 ... Throttle valve 4 ... Actuator 5 ... Throttle opening sensor 7 ... Pressure sensor 8 ... Fuel injection valve 10 ... ECU (Engine control unit) 11 ... Water temperature sensor 12 ... Exhaust passage 13 ... O ₂ sensor 14 ... Accelerator pedal 15 ... Accelerator depression amount sensor 16 ... Air flow meter

Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 45/00376 F02D 45 / 00376B

Claims (4)

[Claims] 1. A control device for an internal combustion engine of an air amount preceding fuel follow-up control system, wherein a throttle valve opening and a fuel supply amount are controlled according to an operation position of an accelerator pedal,
When calculating the fuel injection amount, the throttle valve opening corresponding to the time after the fuel is actually sucked into the cylinder is estimated, and the estimated intake air amount at this time is calculated from the estimated throttle valve opening and the current engine speed. In the control device for an internal combustion engine that determines the fuel injection amount based on the calculated estimated intake air amount, at the time of the calculation of the fuel injection amount, the estimation of the throttle valve opening and the past change in the engine speed are performed at the same time. The engine speed is estimated, the estimated intake air amount at this time is calculated based on the estimated throttle valve opening and the estimated engine speed, and the fuel injection amount is determined based on the calculated estimated intake air amount. Control device for an internal combustion engine. 2. The control device for an internal combustion engine according to claim 1, wherein: a throttle valve opening target value calculating means for calculating a throttle valve opening target value according to an operation position of an accelerator pedal; Storage means for storing a target throttle valve opening value for a predetermined period of time; and a change in throttle valve response delay and a stored throttle valve target target value from the calculated throttle valve target target value. A throttle valve opening estimated value calculating means for calculating a throttle valve opening estimated value in consideration of: a throttle valve opening target value storing means for storing the throttle valve opening estimated value for a predetermined time; A throttle valve opening control value output means for outputting the throttle valve opening target value thus set as a throttle valve opening control value after the lapse of the predetermined time; and a throttle valve according to the throttle valve opening control value. A throttle valve driving means for opening and closing the throttle valve; an engine speed detection and storage means for detecting and storing the engine speed; and an intake valve closing time of the fuel injection cylinder in accordance with the operating state of the engine. Means for calculating the intake valve closing time to be calculated; and means for estimating the engine speed at the time of closing the intake valve for estimating the engine speed at the intake valve closing time of the fuel injection cylinder from the stored change in the engine speed. An estimated intake air amount for calculating an estimated intake air amount at the intake valve closing time at the current time from the stored throttle valve opening estimation value, the intake valve closing time of the fuel injection cylinder, and the estimated engine speed. Means for calculating the amount of air; means for calculating the current amount of intake air at the current time from the target value of the throttle valve opening at the current time; and actual intake air provided in the intake passage of the internal combustion engine. Detecting the intake air amount at the current time from the estimated intake air amount at the intake valve closing time, and adding a deviation obtained by subtracting the intake air amount at the current time from the actual intake air amount at the current time. By
A means for correcting an estimated intake air amount for calculating a correction value for the estimated intake air amount at the intake valve closing time of the fuel injection cylinder; anda fuel supply amount based on the corrected future estimated intake air amount and the target air-fuel ratio. A control device for an internal combustion engine, comprising: means for calculating a fuel supply amount to be calculated; and fuel supply means for supplying fuel at the calculated fuel supply amount. 3. A control device for an internal combustion engine of an air amount advanced fuel follow-up control system wherein an opening degree of a throttle valve and a fuel supply amount are controlled according to an operation position of an accelerator pedal,
When calculating the fuel injection amount, the throttle valve opening corresponding to the time after the fuel is actually sucked into the cylinder is estimated, and the estimated intake air amount at this time is calculated from the estimated throttle valve opening and the current engine speed. And correcting the calculated estimated intake air amount with the current intake air amount and the current estimated intake air amount to calculate a correction value of the estimated intake air amount, and determining the fuel injection amount based on the corrected estimated intake air amount. In the engine control device, the estimated intake air amount is stored, and the fuel calculated at the time of calculating the fuel injection amount is used as a current estimated intake air amount used at the time of calculating the correction value of the estimated intake air amount. A control device for an internal combustion engine, characterized in that an estimated intake air amount calculated before the same time as the time taken into the cylinder is used. 4. A control device for an internal combustion engine according to claim 3, wherein: a throttle valve opening target value calculating means for calculating a throttle valve opening target value according to an operation position of an accelerator pedal; Storage means for storing a target throttle valve opening value for a predetermined period of time; and a change in throttle valve response delay and a stored throttle valve target target value from the calculated throttle valve target target value. In consideration of the above, a throttle valve opening estimated value calculating means for calculating the throttle valve opening estimated value, and the stored throttle valve opening target value is output as the throttle valve opening control value after the lapse of the predetermined time. A throttle valve opening control value output means, a throttle valve driving means for opening and closing the throttle valve in accordance with the throttle valve opening control value, and a fuel injection valve according to an engine operating state. Means for calculating the closing time of the intake valve for calculating the closing time of the intake valve of the cylinder; estimated intake air for calculating the estimated future intake air amount from the stored estimated value of the throttle valve opening and the current engine speed. Calculating means for calculating the amount of air; storing means for storing the calculated amount of estimated intake air; storing means for detecting the amount of intake air provided in the intake passage of the internal combustion engine; Reading means for reading out the estimated intake air amount corresponding to the current time as the intake air amount at the current time among the estimated intake air amounts stored so far; and the stored estimated intake air amount. By adding a deviation obtained by subtracting the intake air amount at the current time from the estimated intake air amount at the intake valve closing time to the actual intake air amount at the current time, the fuel injection Means for calculating a correction value of the estimated intake air amount at the intake valve closing time of the cylinder, and a fuel for calculating a fuel supply amount from the corrected estimated future intake air amount and the target air-fuel ratio A control device for an internal combustion engine, comprising: a supply amount calculation unit; and a fuel supply unit configured to supply the calculated fuel supply amount of fuel.