JPH09126036A - Throttle opening learning device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To grasp the correct throttle opening by appropriately modifying the characteristics of a throttle sensor. SOLUTION: A throttle valve 19 is provided in an air intake tube 11, and a throttle sensor 31 to detect the opening of the valve 19 is provided in the vicinity thereof. An air flow meter 32 to detect the sucked air volume is provided on the downstream side of an air cleaner 15. An electronic control unit(ECU) 51 divides the throttle opening for each moment into ranges, and the reference sucked air volume is calculated for each range based on the throttle opening after learning and the engine rotational speed, and the reference sucked air volume is compared with the actual sucked air volume. The correction value is calculated based on the comparative results, etc., and the throttle opening after learning is recognized based on the correction value, and the opening of the throttle valve to be detected is learned. The throttle opening after learning is close to the actual value by the calculation of the correction value and the learning whether the opening is in the intermediate opening range, or in the vicinity of the full opening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle opening learning device for an internal combustion engine, and more specifically, it accurately grasps an accurate throttle opening for proper control by appropriately correcting a detection value from a throttle sensor. The present invention relates to a throttle opening learning device for an internal combustion engine for performing the above.

[0002]

2. Description of the Related Art Conventionally, there has been generally known a technique for accurately detecting a fully closed state of a throttle valve during engine operation. For example, at the beginning of the engine, the opening of the throttle valve (throttle opening) is the minimum value (the maximum value of the output voltage when the output voltage of the opening sensor increases as the throttle valve opening decreases). Is stored as Thereafter, every time a signal indicating that the opening is smaller than this is input, the correction value is stored as a new fully closed position based on the voltage value, and the stored value is compared. In other words, if an affirmative determination is made as to whether the current signal value is within a predetermined allowable range with respect to the stored value, or if both signal values match, the throttle valve is fully closed. It is judged that there is.

Therefore, according to the above-mentioned technique, the minimum opening of the idle switch is widened by the action of the fast idle mechanism, or the fully closed position of the throttle valve becomes large due to the change over time. Even in this case, the fully closed state is accurately detected. As a result, the detection accuracy of the fully closed state can be improved.

However, in the above-mentioned prior art, although it is possible to accurately detect the fully closed state of the throttle valve by the above control, it is difficult to accurately grasp the middle opening degree or the fully opened state of the throttle valve. there were. That is, the throttle sensor is prone to wear over time, and therefore its output value may also change over time. Therefore, it is very difficult to accurately grasp the opening degree of the throttle valve in all the regions only by accurately grasping the fully closed state.

On the other hand, for example, Japanese Patent Laid-Open No. 63-1433.
In Japanese Patent No. 48, the intake air amount of the engine is estimated from the opening of the throttle valve and the engine speed, and
The actual intake air amount is detected. Then, when the operating state of the engine is in a steady state, the estimated intake air amount and the actual intake air amount are compared, and the estimated specification is learned and changed based on the comparison result. According to such a technique, even if the output value of the throttle sensor fluctuates over time, the fluctuation can be followed to some extent, and controllability in fuel injection control can be improved.

[0006]

However, the variation characteristic of the output value from the throttle sensor is not a linear one corresponding to the magnitude of the throttle opening. For example, in a relatively small opening state, even if the output value error is small,
The error may increase in a large opening state. Therefore, it is not always possible to accurately grasp the throttle opening simply by learning and changing the estimated specifications by the technique described in the above publication. As a result, for example, when the open loop control is performed based on the opening of the throttle valve, the control may be performed based on an inaccurate detection value. There was a risk that it would not be possible to make an appropriate correction to the above, and the controllability would be deteriorated.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a throttle opening learning device for an internal combustion engine without separately providing a stopper, a reference position sensor, or the like. It is an object of the present invention to provide a throttle opening degree learning device for an internal combustion engine, which is capable of appropriately correcting the characteristics of the throttle sensor even if there is a difference in characteristics depending on the opening degree and grasping an accurate throttle opening degree.

[0008]

In order to achieve the above object, in the present invention, as shown in FIG.
A throttle sensor M4 for detecting the opening degree of a throttle valve M3 provided in the middle of the intake passage M2, and an actual throttle sensor M4 provided in the middle of the intake passage M2 of the internal combustion engine M1 and introduced into the internal combustion engine M1. An intake air amount sensor M5 for detecting an intake air amount, an operating state detecting means M6 for detecting an operating state of the internal combustion engine M1 excluding the opening degree of the throttle valve M3 and the intake air amount, and the operating state detection Based on the detection result of the means M6, a reference intake air amount calculating means M7 for calculating a reference intake air amount, an output value from the intake air amount sensor M5, and a calculation calculated by the reference intake air amount calculating means M7. And the throttle sensor M4 based on the comparison result.
Correction value calculating means M8 for calculating the correction value of the output value from
And an opening degree learning means M for learning the opening degree of the throttle valve M3 based on the correction value calculated by the correction value calculation means M8 and the calculated value from the throttle sensor M4.
9 is a throttle opening learning device for an internal combustion engine, wherein the output value from the throttle sensor M4 is divided into regions, and the comparison and the correction value are calculated by the correction value calculating means M8. The gist is that learning of the throttle valve opening M9 by the opening learning means M9 is performed for each of the divided areas.

According to the above configuration, as shown in FIG.
The opening of a throttle valve M3 provided in the intake passage M2 of the internal combustion engine M1 is detected by a throttle sensor M4. An actual intake air amount introduced into the internal combustion engine M1 is detected by an intake air amount sensor M5 provided in the middle of the intake passage M2. Further, the operating state detecting means M6 detects the operating state of the internal combustion engine M1 excluding the opening degree of the throttle valve M3 and the intake air amount.

Then, the reference intake air amount calculating means M7 calculates the reference intake air amount based on the detection result of the operating state detecting means M6. Further, the correction value calculation means M
8 compares the output value from the intake air amount sensor M5 with the calculated value calculated by the reference intake air amount calculating means M7. At the same time, the correction value of the output value from the throttle sensor M4 is calculated based on the comparison result.
Then, based on the correction value calculated by the correction value calculating means M8 and the calculated value from the throttle sensor M4,
The opening degree of the throttle valve M3 is learned by the opening degree learning means M9.

Therefore, the throttle valve M after learning is performed.
Regardless of whether it is in the middle opening range or in the vicinity of full opening, the opening of 3 is closer to the actual value by calculating the correction value based on the intake air amount and learning by the correction value. Become. Therefore, the output value from the throttle sensor M4 is
Even if a change occurs over time, it is possible to accurately grasp the opening degree of the throttle valve M3.

Further, in the present invention, the throttle sensor M4
The output value from the area is divided into regions, and the comparison and the correction value are calculated by the correction value calculating means M8.
In addition, the learning of the throttle valve opening M9 by the opening learning means M9 is performed for each of the divided areas.
Therefore, even if the characteristics of the throttle sensor M4 are different (not in a linear relationship) for each opening area of the throttle valve M3, the characteristics can be appropriately corrected for each divided area.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which a throttle opening learning device for an internal combustion engine according to the present invention is embodied in a gasoline engine will now be described in detail with reference to the drawings.

FIG. 2 is a schematic configuration diagram showing a throttle opening learning device for the engine 1 as an internal combustion engine in the present embodiment. An engine 1 mounted on an automobile has a plurality of cylinders, and a cylinder block 2 constituting the engine 1 has cylinder bores 3 for the number of cylinders. A cylinder head 4 is mounted on the upper side of the cylinder block 2 so as to close each cylinder bore 3. A piston 5 is provided in each cylinder bore 3 so as to be vertically movable,
The piston 5 is connected to a crankshaft (not shown) via a connecting rod 6. Further, inside the cylinder bore 3, a space surrounded by the piston 5 and the cylinder head 4 is a combustion chamber 7. Further, lubricating oil in an oil pan (not shown) is supplied to the respective parts such as the cylinder bore 3 and the connecting rod 6 during operation of the engine 1.

The cylinder head 4 is provided with spark plugs 8 corresponding to the respective combustion chambers 7. Also,
The cylinder head 4 is provided with an intake port 9 and an exhaust port 10 communicating with each combustion chamber 7, and an intake pipe (constituting an intake passage) 11 is provided in each of these ports 9 and 10.
And the exhaust pipe 12 communicate with each other and are connected. Furthermore, an opening / closing intake valve 13 and an exhaust valve 14 are provided at each open end of the intake port 9 and the exhaust port 10 communicating with the combustion chamber 7. The intake valve 13 and the exhaust valve 14 are opened and closed in conjunction with the rotation of a crankshaft by a valve train including a camshaft (not shown). The opening / closing timing of each of the valves 13 and 14 is synchronized with the rotation of the crankshaft. That is, each of the valves 13 and 14 is adapted to be opened and closed at a predetermined timing in synchronization with a series of strokes of an intake stroke, a compression stroke, an explosion / expansion stroke and an exhaust stroke.

An air cleaner 15 is provided on the inlet side of the intake pipe 11.
Is provided. A surge tank 16 for smoothing the pulsation of the air passing through the passage 11 is provided in the middle of the intake pipe 11. Further, on the downstream side of the surge tank 16, near the intake port 9 for each cylinder, an injector 17 for fuel injection is provided. Fuel of a predetermined pressure is supplied to these injectors 17 from a fuel tank (not shown) by a fuel pump. On the other hand, on the outlet side of the exhaust pipe 12, a catalytic converter 18 having a built-in three-way catalyst for purifying exhaust gas is provided.

The engine 1 has an air cleaner 15
Is taken in through the intake pipe 11 including the surge tank 16. Further, when fuel is injected from each injector 17 simultaneously with the introduction of the outside air, a mixture of the outside air and the fuel is taken into the combustion chamber 7 in synchronization with the opening of the intake valve 13 in the intake stroke.
Further, the air-fuel mixture taken into the combustion chamber 7 is
As a result, the air-fuel mixture explodes and burns, and a driving force is obtained in the engine 1. And the explosion
The exhaust gas after combustion is supplied to the exhaust valve 14 during the exhaust stroke.
The exhaust pipe 1 in synchronization with the opening of the exhaust pipe 1
2 is discharged outside through the catalytic converter 18 and the like.

On the upstream side of the surge tank 16, there is provided a throttle valve 19 which opens and closes in conjunction with the operation of an accelerator pedal (not shown). By opening and closing the throttle valve 19, the amount of outside air taken into the intake pipe 11, that is, the intake air amount Q is adjusted.

In the vicinity of the throttle valve 19, the valve 1
A throttle sensor 31 for detecting the opening of 9, that is, the detected throttle opening ADTA is provided. This throttle sensor 31 detects the detected throttle opening ADT.
The A signal (A / D converted by the ECU 51 described later) is output, and the idle signal is output by the idle contact that is turned on only when the throttle valve 19 is at the fully closed position.

An air flow meter 32 as an intake air amount sensor for detecting the intake air amount Q into the intake pipe 11 is provided downstream of the air cleaner 15. In addition, an intake air temperature sensor 33 that detects the temperature of the air taken into the intake pipe 11, that is, the intake air temperature THA is provided between the air cleaner 15 and the air flow meter 32.

Further, in the middle of the exhaust pipe 12, an oxygen sensor 34 for detecting the oxygen concentration OX in the exhaust, that is, for detecting the exhaust air-fuel ratio in the exhaust pipe 12 is provided. Further, the cylinder block 2 is provided with a water temperature sensor 35 that detects the temperature of the cooling water of the engine 1, that is, the cooling water temperature THW.

The ignition signal distributed by the distributor 20 is applied to the ignition plug 8 for each cylinder. The distributor 20 distributes the high voltage output from the igniter 21 to each ignition plug 8 in synchronization with the rotation of the crankshaft, that is, the crank angle. The ignition timing of each ignition plug 8 is determined by the high voltage output timing from the igniter 21.

The distributor 20 incorporates a rotor (not shown) that rotates in association with the rotation of the crankshaft. And the distributor 20
A rotation speed sensor 36 for detecting the rotation speed of the engine 1, that is, the engine rotation speed NE from the rotation of the rotor is provided. Similarly, the distributor 20 is provided with a cylinder discrimination sensor 37 that detects a crank angle reference signal of the engine 1 at a predetermined rate according to the rotation of the rotor. In this embodiment, the crankshaft makes two rotations for a series of strokes in the engine 1,
The rotation speed sensor 36 detects the crank angle at a rate of 30 ° CA per pulse. The cylinder discrimination sensor 37 is 1
The crank angle is detected at a rate of 360 ° CA per pulse. Further, an automatic transmission 2 drivingly connected to the engine 1
5 is provided with a vehicle speed sensor 38 for detecting the speed of the vehicle, that is, the vehicle speed SP.

In addition, the intake pipe 11 of this embodiment is provided with a bypass passage 22 that bypasses the throttle valve 19 and connects the upstream side and the downstream side of the valve 19 to each other. In the middle of the bypass passage 22, a well-known linear solenoid type idle speed control valve (ISCV) 23 is provided. And IS
The bypass passage 22 is opened and closed by driving and controlling the CV 23 based on a predetermined control signal. The ISCV 23 is operated to stabilize the idling state of the engine 1 when the engine 1 is idling when the throttle valve 19 is fully closed, and feedback control of the actual rotational speed is performed so as to reach the target rotational speed during idling. Is. Therefore, when the engine 1 is idling, the amount of air flowing through the bypass passage 22 is adjusted by controlling the opening degree of the ISCV 23 and the valve opening time thereof, that is, by performing the ISC control, and intake air to the combustion chamber 7 is adjusted. The quantity Q is adjusted.

In addition, the engine 1 is provided with a starter 24 for imparting a rotational force to the engine 1 by cranking at the time of starting the engine 1. Further, the starter 24 is provided with a starter switch 39 for detecting the operation / non-operation of the starter 24. As is well known, the starter switch 39 is turned on and off by the operation of an ignition switch (not shown). Since the starter 24 is operated while the ignition switch is being operated, the starter switch 39 outputs “ An “ON” starter signal STS is output.

The automatic transmission 25 constitutes a part of an external load together with, for example, an air conditioner (air conditioner) which is not shown. In addition, a neutral start switch 40 is provided inside the automatic transmission 25. The neutral start switch 40 detects that the current shift position ShP is in a neutral range [N range (including P range)]. That is, it is possible to detect whether the current shift position ShP is in the N range or the drive range (D range).

The injector 17, the igniter 21, and the ISCV 23 are electronic control units (hereinafter simply referred to as "EC
U ”) 51, and their drive timing is controlled by the operation of the ECU 51. The ECU 51 constitutes a reference intake air amount calculation means, a correction value calculation means, and an opening degree learning means. This ECU 51
The throttle sensor 31, the air flow meter 32, the intake air temperature sensor 33, the oxygen sensor 34, the water temperature sensor 35, the rotation speed sensor 36, the cylinder discrimination sensor 37, the vehicle speed sensor 38, the starter switch 39, and the neutral start switch 40 (these are described above). Of which, throttle sensor 3
1 and an air flow meter 32 are all connected to each other, which constitutes an operating condition detecting means). And
The ECU 51 controls the ignition timing of the engine 1, the fuel injection amount control, the ISC control, and the like in order to control the sensors 31 to 31.
8, each injector 1 based on the output signals from the starter switch 39 and the neutral start switch 40.
7, the igniter 21, the ISCV 23, etc. are suitably driven and controlled.

Here, the electrical configuration of the ECU 51 will be described with reference to the block diagram of FIG. The ECU 51 includes a central processing unit (CPU) 52, a read-only memory (ROM) 53 that stores a predetermined control program and the like in advance, and a random access memory (R
AM) 54, a backup RAM 55 for storing the stored data, a timer counter 56, etc., and these units, an external input circuit 57, an external output circuit 58, etc. are connected by a bus 59 as a theoretical operation circuit. . In the present embodiment, the ROM 53 has a program related to learning and recognizing the throttle opening TA such as a “throttle opening correction value calculation and learning routine” described later,
Other programs regarding fuel injection control, ignition timing control, and the like, or a predetermined map and the like are stored in advance.
In addition, in the present embodiment, the timer counter 56 can output an interrupt signal at every predetermined time and simultaneously perform a plurality of counting operations.

The external input circuit 57 includes the throttle sensor 31, the air flow meter 32, and the intake air temperature sensor 3 described above.
3, oxygen sensor 34, water temperature sensor 35, rotation speed sensor 3
6, a cylinder discrimination sensor 37, a vehicle speed sensor 38, a starter switch 39, a neutral start switch 40, etc. are connected. In addition, the external output circuit 58 includes the injectors 17, the igniter 21, and the ISCV.
23 are connected to each other.

Then, the CPU 52 (ECU 51) inputs the sensors 31 to 38, which are input via the external input circuit 57,
Each signal from the starter switch 39 and the neutral start switch 40 is read as an input value. Also, C
The PU 51 (ECU 51) uses the read input values to inject each injector 17, igniter 21, and ISC.
V23 and the like are preferably driven and controlled.

Next, the processing operation for the throttle opening degree learning in the engine throttle opening degree learning device configured as described above will be described with reference to FIGS.
4 and 5 are flow charts for explaining the "throttle opening correction value calculation and learning routine" executed by the ECU 51, and this routine is executed by a regular interruption every predetermined time.

When the processing shifts to this routine, first in step 101, the ECU 51 determines the intake air amount Q, based on the signals from the air flow meter 32, the throttle sensor 31, the rotation speed sensor 36, the vehicle speed sensor 38 and the like.
Detection signals indicating various operating states such as the detected throttle opening ADTA, the engine speed NE, and the vehicle speed SPD are read.

Next, at step 102, the ECU 5
1 determines whether or not the current operating state is a steady state suitable for learning the throttle opening based on the detection signals indicating the various operating states read this time. Here, as a condition for being in a steady state, for example, the deviation of the vehicle speed SPD this time compared with the previous routine is “± 3 km /
less than “h”, the deviation of the intake air amount Q this time compared to the previous routine is less than “± 0.1 m ³ / h”, and the detected throttle opening ADTA of this time compared to the previous routine The deviation is less than “± 1 °”, the deviation of the engine speed NE this time compared to the previous routine is less than “± 10 rpm”, and the like. Then, if the current operating state is not in a steady state, the operating state is considered to be unstable in order to learn the throttle opening, and the subsequent processing is temporarily terminated.

If the current operating state is in a steady state, then in step 103, the reference intake air amount QCAL is calculated based on the learned throttle opening TA and the engine speed NE read this time. Here, the post-learning throttle opening TA means the detected throttle opening ADTA read from the throttle sensor 38.
This is a value obtained by adding a correction value GTA described later. The reference intake air amount QCAL is calculated based on the post-learning throttle opening TA and the engine speed NE by referring to a map as shown in FIG. 6, for example. That is,
When the engine speed NE at that time is high, the reference intake air amount QCAL becomes a large value as the post-learn throttle opening TA increases. On the other hand, when the engine speed NE at that time is relatively low, the reference intake air amount Q
The CAL does not become a large value even if the throttle opening TA increases after learning.

Next, the ECU 51 sets the throttle zone i in step 104 (subroutine). This is because the correction value GTA to be learned for any region of the throttle opening in the subsequent processing,
As a result, this is a process for determining whether to calculate the throttle opening TA after learning. Here, the description of this routine will be temporarily interrupted, and the processing operation when setting the throttle zone i will be described with reference to the flowchart of FIG. 7. In the present embodiment, the throttle zone i is the detected throttle opening A at that time.
Depending on DTA etc., "0", "1", "2", "3",
It is set in any area of ("4").

FIG. 7 is a flow chart showing a "throttle zone setting routine" for setting the throttle zone i executed by the ECU 51, which is executed as a subroutine of the above step 104.

At step 201, the ECU 51
First, the throttle zone i is set to "1". Next, at step 202, it is judged if the detected throttle opening ADTA is equal to or larger than the throttle zone value TAi at that time. Here, as shown in FIG. 8, the throttle zone value TAi is a value that represents the throttle opening degree in the throttle zone i at that time by an angle. For example, when the throttle zone i is “1”, The throttle zone value TAi becomes “20 °”. Then, the detected throttle opening degree ADTA is equal to the throttle zone value TAi.
If it is less than TAi = “20 °” since i = “1” at the beginning, the process proceeds to step 203, and the value obtained by subtracting “1” from the throttle zone i up to then is set as the final throttle zone i. Set. Therefore, for example, when the detected throttle opening ADTA is less than “20 °”, the throttle zone i is set to “0”. And the ECU
51 temporarily ends the subsequent processing.

If the detected throttle opening ADTA is greater than the throttle zone value TAi, step 204
Move to. In step 204, a value obtained by adding "1" to the throttle zone i up to then is temporarily set as the throttle zone i (if i = "1" at the beginning, i = "2" is temporarily set. Is set to).

Further, in step 205, the currently set throttle zone i is the maximum zone im.
It is determined whether or not ax (imax = “4” in the present embodiment) or more. And throttle zone i
If is greater than or equal to the maximum zone imax, the process proceeds to step 203, and a value obtained by subtracting “1” from the throttle zone i up to that point is set as the final throttle zone i. If the throttle zone i is not equal to or larger than the maximum zone imax, step 202
And executes the above processing.

As described above, in this routine, the throttle zone i is set to any of "0", "1", "2", and "3" according to the detected throttle opening degree ADTA at that time. That is, the detected throttle opening AD
When TA is less than “20 °”, the throttle zone i is “0”, and when the detected throttle opening ADTA is “20 °” or more and less than “40 °”, the throttle zone i is “1”. When the detected throttle opening ADTA is equal to or more than "40 °" and less than "60 °", the throttle zone i is "2", and when the detected throttle opening ADTA is "60 °" or more, the throttle zone i is " 3 ”, respectively.

Now, returning to the "throttle opening correction value calculation and learning routine", the continuation of the processing will be described. After the throttle zone i is set in the subroutine of step 104 as described above, step 105
At, the count value N of the counter is cleared to "0".

Next, at step 106, the difference between the intake air amount Q read this time and the reference intake air amount QCAL calculated this time is a predetermined value α (α> 0).
Is greater than or equal to. Step 107
At, it is determined whether or not the difference between the intake air amount Q and the reference intake air amount QCAL is larger than the predetermined value -β (β> 0) set in the negative direction. And step 1
When negative determination is made in both step 06 and step 107, there is almost no difference between the intake air amount Q and the reference intake air amount QCAL, and the correction value GTA is used for the calculation of the post-learn throttle opening TA. It is determined that there is no need, and the subsequent processing is temporarily terminated.

On the other hand, in step 106, the difference between the intake air amount Q and the reference intake air amount QCAL is the predetermined value α.
If it is larger than the above, it is determined that the actual opening of the throttle valve 19 is larger than the detected throttle opening ADTA, and the processes of steps 108 to 116 are executed. In step 107, if the difference between the intake air amount Q and the reference intake air amount QCAL is larger than the predetermined value −β in the minus side, the actual throttle valve 19
It is determined that the opening degree of is smaller than the detected throttle opening degree ADTA, and the processes of steps 117 to 125 are executed.

First, when it is determined in step 106 that the difference between the intake air amount Q and the reference intake air amount QCAL is larger than the predetermined value α, in step 108, the throttle set by the subroutine of step 104 is set. It is determined whether the zone i is "0". When the throttle zone i is "0", the process proceeds to step 109.

In step 109, a value obtained by adding "1" to the throttle zone i thus far is set as a new throttle zone i. Also, the following step 11
At 0, the count value N of the counter is incremented by "1".

Further, in step 111, the count value N of the counter is incremented by "1".
Then, in the subsequent step 112, a value obtained by adding a predetermined value γ (for example, “0.5 °”) to the previous correction value GTA _i−1 is set as the current correction value GTA _i .

Further, in step 113, it is determined whether or not the correction value GTA set this time exceeds the maximum allowable correction value GTAMAX. This allowable maximum correction value GT
AMAX may be a predetermined value or may be the detected throttle opening ADTA at that time.
May be about 20%. Then, the correction value GT
If A does not exceed the maximum allowable correction value GTAMAX, the process directly proceeds to step 115. Also,
If the correction value GTA exceeds the maximum allowable correction value GTAMAX, in step 114, the maximum allowable correction value GTAMAX is set as the correction value GTA in order to guard the upper limit of the correction.

Further, in step 115, it is determined whether the count value N of the counter is "2" or more. Then, if the count value N is not equal to or greater than “2”, the process proceeds to step 109 described above. If the count value N is equal to or greater than “2”, the subsequent process is once ended to end the calculation of the correction value GTA.

On the other hand, when the throttle zone i is not "0" at step 108, the routine proceeds to step 116. In step 116, it is determined whether the throttle zone i is "3". If the throttle zone i is not "3", step 1
The processing shifts to 11. If the throttle zone i is “3”, the process proceeds to step 110.

Therefore, for example, when the throttle zone i set in the subroutine of step 104 is "0", an affirmative decision is made in step 108, and step 1
At 09, the throttle zone i is once set to "1". Then, the count value N becomes "2" through steps 110 and 111, and the correction value GTA in the throttle zone i = "1" is additionally calculated in step 112. Then, after passing through steps 113 and (114), an affirmative decision is made in step 115, and the subsequent processing is once terminated. That is, the throttle zone i is "0".
In the case of, the correction value GTA in the throttle zone i = “1” is additionally calculated.

Further, for example, the throttle zone i is "1".
In the case of, a negative determination is made in step 108 and a negative determination is made in step 116. Then, the count value becomes "1" in step 111, and the correction value GTA in the throttle zone i = "1" is added and calculated in step 112. Then, after passing through steps 113 and (114), a negative determination is made in step 115, and the throttle zone i is set to "2" this time in step 109. Then, in steps 110 and 111, the count value N is "3".
Then, in step 112, the throttle zone i = “2”
The correction value GTA is calculated by addition. Then, after passing through steps 113 and (114), an affirmative decision is made in step 115, and the subsequent processing is once terminated. That is, when the throttle zone i is “1”, the correction values GTA in the throttle zones i = “1” and “2” are additionally calculated.

Further, for example, when the throttle zone i is "2", a negative determination is made in step 108 and a negative determination is made in step 116. And step 1
At 11, the count value becomes “1”, and at step 112, the correction value GTA in the throttle zone i = “2” is added and calculated. Then, after passing through steps 113 and (114), a negative determination is made in step 115, and step 10
At 9, the throttle zone i is set to "3" this time.
Then, the count value N becomes “3” in steps 110 and 111, and the throttle zone i =
The correction value GTA for “3” is additionally calculated. Then, after going through steps 113 and (114), step 1
An affirmative decision is made in 15, and the subsequent processing is once terminated.
That is, when the throttle zone i is “2”, the correction value G in the throttle zone i = “2” and “3”
TA is added and calculated.

At the same time, for example, when the throttle zone i is "3", a negative determination is made in step 108 and an affirmative determination is made in step 116. And step 1
At 10 and 111, the count value becomes “2”, and at step 112, the correction value G in the throttle zone i = “3”
TA is added and calculated. Then, step 113, (1
After 14), an affirmative decision is made in step 115, and the subsequent processing is once terminated. That is, when the throttle zone i is “3”, the throttle zone i = “3”
The correction value GTA is calculated by addition.

Further, as described above, in step 107, when the difference between the intake air amount Q and the reference intake air amount QCAL is larger than the predetermined value -β on the minus side, the actual opening degree of the throttle valve 19 is Detection throttle opening ADT
Step 117 is judged to be unexpectedly smaller than A
-The process of step 125 is performed.

First, at step 117, the throttle zone i set by the subroutine at step 104 is set.
Is "0", and if "0", the process proceeds to step 118.

At step 118, a value obtained by adding "1" to the throttle zone i up to then is set as a new throttle zone i. Also, the following step 11
In 9 and 120, the count value N of the counter is incremented by "1".

Then, in the following step 121,
Predetermined value from the previous correction value GTA _i-1 δ (for example, "0.5
The value obtained by subtracting “°”) is set as the current correction value GTA _i .

Further, in step 122, it is judged whether or not the correction value GTA set this time is lower than the allowable minimum correction value GTAMIN. This allowable minimum correction value GTAMIN may be a predetermined value that is set in advance, or may be a value that is about 20% of the detected throttle opening degree ADTA at that time. If the correction value GTA is not lower than the allowable minimum correction value GTAMIN, the step 1 is directly executed.
The processing shifts to 24. If the correction value GTA is lower than the allowable minimum correction value GTAMIN, step 1
23, the minimum allowable correction value GTAMIN is set to the correction value G
Set as TA.

Further, in step 124, it is judged whether or not the count value N of the counter is "2" or more. Then, if the count value N is not equal to or greater than "2", the process proceeds to step 118 described above. If the count value N is equal to or greater than “2”, the subsequent process is once ended to end the calculation of the correction value GTA.

On the other hand, if the throttle zone i is not "0" at step 117, the routine proceeds to step 125. In step 125, it is determined whether the throttle zone i is "3". If the throttle zone i is not "3", step 1
The processing shifts to 20. If the throttle zone i is "3", the process proceeds to step 119.

Therefore, steps 108 to 11
As already described in the process of 6, for example, the throttle zone i
Is 0, the correction value GTA in the throttle zone i = “1” is additionally calculated. When the throttle zone i is “1”, the throttle zone i =
The correction values GTA for “1” and “2” are added and calculated. Furthermore, when the throttle zone i is “2”,
The correction values GTA in the throttle zones i = “2” and “3” are additionally calculated. In addition, the throttle zone i
Is 3, the correction value GTA in the throttle zone i = “3” is additionally calculated.

As described above, in the present embodiment, the post-learn throttle opening TA (ADTA + GTA)
And the reference intake air amount QC based on the engine speed NE
AL is calculated and the reference intake air amount QCAL is calculated.
And the actual intake air amount Q are compared. Also,
Based on the comparison result, the detected throttle opening degree ADTA from the throttle sensor 31 is set to the actual throttle valve 19
It is determined whether the opening degree is larger or smaller than the opening degree. Then, the correction value GTA is calculated based on the determination result. Further, the post-learning throttle opening degree TA (ADTA + GTA) is recognized based on the correction value GTA, and the opening degree of the throttle valve 19 to be detected is learned.

Therefore, the post-learning throttle opening degree TA after learning, whether it is in the middle opening degree area or in the vicinity of full opening, has the above-mentioned correction value GT based on the intake air amount Q.
By calculating A and learning with the correction value, the value becomes closer to the actual value. Therefore, even if the detected throttle opening ADTA, which is the output value from the throttle sensor 31, changes with time due to the wear of the throttle sensor 31, it is possible to accurately grasp the opening of the throttle valve 19. It becomes possible to do.

Therefore, when open loop control such as asynchronous injection control or FOTP control is performed based on the opening of the throttle valve 19, the control is performed based on an incorrect opening detection value. That situation can be avoided. As a result, it is possible to make appropriate corrections to the control content, and thus improve controllability.

Further, in the present embodiment, the characteristics of the throttle sensor 31 can be properly corrected and the correct opening of the throttle valve 19 can be grasped without newly providing a stopper or a reference position sensor. . Therefore, it is possible to achieve the above-described effects without increasing the cost.

Further, in the present embodiment, the throttle zone i (area) is set based on the output value (detected throttle opening ADTA) from the throttle sensor, and the correction value GTA is calculated and calculated for each throttle zone i. The opening degree of the throttle valve 19 is learned. Therefore, the characteristics of the throttle sensor 31 are different for each opening area of the throttle valve 19 (not in a linear relationship).
Even in that case, the characteristic can be appropriately corrected. For example, as shown in FIG. 9, in the small / medium opening area,
The detection throttle opening ADTA is shifted to the plus side,
In the large opening area, even if the detected throttle opening ADTA is deviated to the negative side, the deviation can be properly corrected. As a result, the above-described effects can be more reliably achieved.

The present invention is not limited to the above embodiment, but may be configured as follows, for example. (1) In the above-described embodiment, the throttle zone i is set according to the detected throttle opening degree ADTA at that time, and the throttle zone i is set to "0"-
It was decided to adopt the four categories of "3". On the other hand, three or less divisions and five or more divisions may be adopted. (2) In the above embodiment, the intake air amount Q is detected by the air flow meter 32, but a value calculated based on the pressure in the intake pipe 11, the engine speed NE, etc. is adopted as the detection value. Good.

(3) In determining whether or not it is in a steady state, conditions other than the conditions described in the above embodiment may be adopted. (4) In the above-described embodiment, the case where the opening degree of the throttle valve 19 mounted on the gasoline engine 1 is learned is described, but it may be realized as that of a diesel engine.

(5) In the above embodiment, the throttle zone i is set according to the detected throttle opening degree ADTA at that time, and four zones of "0" to "3" are adopted as the throttle zone i. I decided.
On the other hand, a continuous (linear) value may be adopted as the throttle zone i, and complementary calculation may be performed when the learning value GTA is calculated.

The technical idea which is not described in the claims and can be grasped from the above-described embodiment will be described below together with its effect. (A) A control device for an internal combustion engine, wherein control is performed based on the throttle opening learned by the throttle opening learning device for the internal combustion engine according to claim 1.

(B) In the control device for the internal combustion engine according to the above-mentioned appendix (a), the control is open loop control.

[0072]

As described in detail above, according to the present invention,
In the throttle opening learning device for an internal combustion engine, it is not necessary to newly install a stopper or a reference position sensor, etc., and even if there is a difference in the characteristics depending on the opening, the characteristics of the throttle sensor are properly corrected and The excellent effect of being able to grasp a wide throttle opening is achieved.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram illustrating a basic conceptual configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing a throttle opening degree learning device for an engine according to an embodiment.

FIG. 3 is a block diagram illustrating an electrical configuration of an ECU.

FIG. 4 is a flowchart showing a “throttle opening correction value calculation and learning routine” executed by the ECU.

FIG. 5 is a flowchart showing a continuation of FIG. 4;

FIG. 6 is a map showing a relationship of a reference intake air amount with respect to a throttle opening after learning and an engine speed.

FIG. 7 is a flowchart showing a “throttle zone setting routine” which is a subroutine.

FIG. 8 is a chart showing the relationship between throttle zones and throttle zone values.

FIG. 9 is a graph showing an example of a correction value for each throttle zone.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as an internal combustion engine, 11 ... Intake pipe as an intake passage, 19 ... Throttle valve, 31 ... Throttle sensor, 32 ... Air flow meter as an intake air amount sensor, 33 ... Intake temperature sensor which constitutes an operating state detection means ,
34 ... Oxygen sensor constituting operating state detecting means, 35 ...
A water temperature sensor that constitutes the operating state detecting means, 36 ... a rotation speed sensor that constitutes the operating state detecting means, 37 ... a cylinder discrimination sensor that constitutes the operating state detecting means, 38 ... a vehicle speed sensor that constitutes the operating state detecting means, 39 ... A starter switch that constitutes the operating state detecting means, 40 ... A neutral start switch that constitutes the operating state detecting means, 51 ... An ECU as a reference intake air amount calculating means, a correction value calculating means, and an opening degree learning means.

Claims (1)

[Claims] 1. A throttle sensor for detecting the opening of a throttle valve provided in the intake passage of an internal combustion engine, and an actual throttle sensor provided in the intake passage of the internal combustion engine and introduced into the internal combustion engine. An intake air amount sensor for detecting the intake air amount, operating state detection means for detecting the operating state of the internal combustion engine excluding the opening of the throttle valve and the intake air amount, and the operating state detection means Based on the result, while comparing the reference intake air amount calculation means for calculating the reference intake air amount, the output value from the intake air amount sensor and the calculated value calculated by the reference intake air amount calculation means, A correction value calculating means for calculating a correction value of the output value from the throttle sensor based on the comparison result; a correction value calculated by the correction value calculating means; A throttle opening learning device for an internal combustion engine, comprising: an opening degree learning means for learning an opening degree of a throttle valve based on a calculated value from a sensor, wherein an output value from the throttle sensor is divided into regions. In addition, the comparison and the correction value calculation by the correction value calculation means, and the throttle valve opening degree learning by the opening degree learning means are performed for each of the divided areas. A throttle opening learning device for an internal combustion engine.