JP3322006B2 - Full throttle valve detection device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle valve full-close detector for an internal combustion engine, and more particularly to a throttle valve full-close detector having a learning function for learning a throttle opening.

[0002]

2. Description of the Related Art Generally, an internal combustion engine that performs fuel injection control using a computer is provided with a throttle opening sensor that detects the opening of a throttle valve for the purpose of detecting a deceleration or an idle state. Based on the output of the throttle opening sensor, for example, a fuel cut is performed when the throttle valve is fully closed to control fuel consumption to be improved.

[0003] As a throttle valve fully closed detection device for detecting that the throttle valve is fully closed, for example, a device disclosed in Japanese Patent Publication No. Sho 63-15467 is known. The throttle valve fully-closed detecting device disclosed in the publication has a function of sequentially learning a throttle opening signal output from a throttle opening sensor. When the learning value is smaller than the learning value, the learning value stored in the storage means is updated, and the full closing of the throttle valve is detected based on the updated learning value. When it is determined that the throttle valve is fully closed, the throttle valve fully closed detection device outputs a fully closed signal to an engine control computer or the like.

[0004] According to the throttle valve fully closed detecting device having this configuration, for example, when the minimum valve opening of the throttle valve is widening at the time of first idling, the minimum valve opening of the throttle valve is widened due to aging. Even in such a case, it is possible to detect a state in which the throttle valve is closed to the minimum achievable valve opening.

[0005]

As described above, the throttle valve fully closed detecting device having a learning function is provided with a learning value stored in a storage means which is appropriately updated under a predetermined condition;
By comparing the throttle opening signal output from the throttle opening sensor with the throttle opening signal, the throttle valve is fully closed.

Therefore, for example, when the power supply to the storage means is stopped by replacing the battery, or when the storage means storing the learning value is affected by disturbance, the learning value is initialized. Will be done. As described above, the initial value set by the initialization is set in consideration of the output variation of the throttle opening sensor, the assembly error, and the like. The opening degree is set to be larger than the maximum opening degree of the throttle valve generated by the above.

Accordingly, there is a large gap between the initial value set by the initialization and the opening of the throttle valve in a state where the valve is closed to the minimum achievable valve opening (hereinafter referred to as the actual fully closed valve opening). There is. The difference between the initialized learning value and the actual fully closed valve opening is corrected by performing the above-described learning processing.

However, if the difference between the initial value and the actual fully closed valve opening is large, the learning time required for the learning value to become equal to the actual fully closed valve opening becomes longer. Further, in the throttle valve full-close detection device having the above-described conventional configuration, even when the difference between the learning value and the actual full-closed valve opening is large, detection of the full-close of the throttle valve is performed without stopping. If the learning value is large relative to the valve opening, the throttle valve opening calculated based on the learning value is calculated to be small even if the throttle valve is not fully closed, and it is erroneously determined that the throttle valve is fully closed. It happens.

As described above, when the throttle valve fully closed detecting device erroneously determines that the throttle valve is fully closed, various control processes (for example, a fuel cut process at the time of deceleration) performed based on the fully closed signal are performed. There has been a problem that the engine control is not performed accurately and the engine control cannot be properly performed.

The present invention has been made in view of the above points, and inhibits the process of determining whether the throttle is fully closed when the learning value is initialized, and sets the throttle valve based on the engine state of the internal combustion engine. The throttle valve full-closed detection of the internal combustion engine with improved accuracy of the throttle valve fully-closed determination process by canceling the prohibition of the full-closed determination process when it is detected that the state is equivalent to the fully closed state. It is intended to provide a device.

[0011]

FIG. 1 is a diagram illustrating the principle of the present invention.

[0012] As shown in the figure, the calling of claim 1, wherein
In other words, by learning a throttle opening sensor (A2) that outputs a throttle opening signal (TA) corresponding to the opening of the throttle valve (A1) of the internal combustion engine, and learning the throttle opening signal (TA). A learning means (A3) for sequentially updating a learning value (GTA) indicating the minimum valve opening of the throttle valve (A1) and storing the learning value; a throttle opening signal (TA) and a learning value (GT
Judging means for judging the throttle fully closed state based on A)
(A4) , the throttle valve full-close detection device for an internal combustion engine, the initialization detection means (A5) for detecting that the learning value (GTA) is initialized, this initialization detection means (A5) When it is detected that the learning value (GTA) has been initialized, a determination prohibition unit (A6) for prohibiting the process of determining the fully closed state of the throttle performed by the determination unit (A4); and Based on the state of the engine, when it is detected that the throttle valve (A1) has reached a fully closed state, the determination prohibiting means (A6)
And a judgment prohibition canceling means (A7) for canceling the judgment prohibition due to. Claim 2
According to the invention, the throttle valve of the internal combustion engine is fully closed.
In the detection device, the determination prohibition canceling means (A6) is an internal combustion engine.
If the engine is in the engine state, the driver is depressing the accelerator pedal.
The throttle valve is fully closed
It is determined that this state has been reached.
You. The invention according to claim 3 provides the internal combustion engine according to claim 2.
In the engine throttle valve full-close detector,
When the vehicle is stopped,
Medium and the engine speed is less than the predetermined value.
It is characterized by being in a state. Claim 4
The invention described in claim 1 is a throttle valve for an internal combustion engine according to claim 1.
In the fully-closed detection device, the determination prohibition canceling means (A6) includes:
Engine state of internal combustion engine, learning value converges to minimum valve opening
When enough time has passed for the
It is determined that the torque valve is in a fully closed state.
Is what you do. The invention according to claim 5 provides an internal combustion engine
A throttle opening signal corresponding to the opening of the Seki throttle valve
Output throttle opening sensor and this throttle opening
By learning the signal, the minimum valve of the throttle valve
The learning value indicating the opening degree is sequentially updated, and this learning value is stored.
Learning means, based on the throttle opening signal and the learning value
Determination means for determining whether the throttle is fully closed
In the internal combustion engine throttle valve fully closed detection device,
Initialization detection means for detecting that the learning value has been initialized;
This initialization detecting means detects that the learning value has been initialized.
When notified, the fuel tank that stops injection of fuel to the internal combustion engine
Fuel cut prohibition means for prohibiting the execution of cuts, and an internal combustion engine
The throttle valve is fully closed based on the engine status
The fuel cut prohibition means when it is detected that
Prohibition of fuel cut by fuel cut prohibition
A release means is provided.

[0013]

According to the throttle valve full-close detecting device for an internal combustion engine having the above-mentioned structure, the learning value (GTA) is obtained by the initialization detecting means (A5).
Is detected, the determination prohibiting means (A6) prohibits the processing for determining the throttle fully closed state performed by the determining means (A4) (hereinafter referred to as the fully closed determination processing).

On the other hand, the learning means (A3) continues the learning processing even in a state where the full-close judgment processing is prohibited by the judgment prohibiting means (A6), and sequentially updates the learning value (GTA). However, the learning value (GTA) immediately after initialization has a large gap from the opening of the throttle valve (A1) when the valve is closed to the minimum achievable valve opening (actual fully closed valve opening). (GTA)
When the fully closed judgment process is performed based on
As described above, the fully closed judgment of (A1) cannot be performed.

However, when the learning value (GTA) is initialized as described above, the judgment prohibition means (A6) sets the judgment means (A4).
By prohibiting the fully-closed determination process performed by the device, erroneous determination can be prevented.

The prohibition of the full-close determination processing by the determination prohibiting means (A6) is released by the processing of the determination prohibition releasing means (A7). At this time, the determination prohibition canceling means (A7) is based on the engine state of the internal combustion engine, not the throttle opening signal (TA) output from the throttle opening degree sensor (A2), and the throttle valve (A1) is in a fully closed state. Release of the prohibition of judgment when it is detected that That is, the determination prohibition canceling means (A7) uses the learning value (GTA)
The throttle valve (A1) is in the fully-closed equivalent state because it is configured to detect that the throttle valve (A1) is in the fully-closed equivalent state based on the determination factor (engine state of the internal combustion engine) that is not affected by the Can be accurately detected.

Therefore, after the learning value (GTA) is initialized,
Until the learning value (GTA) obtained by the learning means (A3) becomes equivalent to the actual fully closed valve opening, the fully closed determination processing by the determination means (A4) is prohibited. Erroneous determination can be prevented. Therefore, various control processes (for example, a fuel cut process at the time of deceleration) performed at the time of full closing detection can be accurately performed, and engine control can be appropriately performed.

[0018]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is an overall configuration diagram of a fuel injection amount control device according to one embodiment of the present invention. In the figure, 1 is an engine body of an internal combustion engine, 2 is a piston, 3 is a cylinder head,
Reference numeral 4 denotes a combustion chamber formed between the piston 2 and the cylinder head 3, 5 denotes a spark plug, 6 denotes an intake valve, 7 denotes an intake port, 8 denotes an exhaust valve, and 9 denotes an exhaust port.

Each intake port 7 is connected to a surge tank 11 via a corresponding branch pipe 10, and each branch pipe 10 has a fuel injection valve 1 for injecting fuel into the corresponding intake port 7.
2 are installed. Fuel injection from each fuel injection valve 12 is controlled based on an output signal of the electronic control unit 30.

The surge tank 11 is connected to an air cleaner 14 via an intake duct 13, and a throttle valve 15 is provided in the intake duct 13. The bypass passage 16 is formed to bypass the throttle valve 15, and an idle speed control valve (ISCV) 17 is provided in the bypass passage 16. Each exhaust port 9 is connected to an exhaust manifold 18, and an oxygen sensor (O ₂ sensor) 19 having a built-in heater is mounted in the exhaust manifold 18.

The electronic control unit 30 is composed of a digital computer, and is connected to a ROM (Read Only Memory) 32, a RAM (Random Access Memory) 33, a CPU (Microprocessor) 34, and an input port 35 mutually connected by a bidirectional bus 31. And an output port 36. The backup RAM 33a is connected to the CPU 34 via the bus 31a.

The engine body 1 is provided with a water temperature sensor 20 for generating an output voltage proportional to the engine cooling water temperature. The output voltage of the water temperature sensor 20 is inputted to an input port 35 via an A / D converter 37. . The output voltage of the O ₂ sensor 19 is input to the input port 35 via the A / D converter 38.

The surge tank 11 has an absolute pressure sensor 2 for generating an output voltage proportional to the absolute pressure in the surge tank 11.
The output voltage of the absolute pressure sensor 21 is input to the input port 35 via the A / D converter 39.

The throttle valve 15 includes a throttle valve 15
The throttle opening sensor 22 for detecting the opening of the valve is mounted. The throttle opening sensor 22 is configured by a sliding resistance or the like interlocked with the throttle valve 15,
It is configured to output a voltage signal (throttle opening signal) proportional to the opening of the throttle valve 15. The throttle opening signal generated by the throttle opening sensor 22 is input to the input port 35 via the A / D converter 42.

The rotation speed sensor 23 is configured to generate an output pulse each time the crankshaft rotates a predetermined crank angle. The output pulse of the rotation speed sensor 23 is input to an input port 35. From this output pulse, CP
In U34, the engine speed is calculated.

The vehicle speed sensor 24 is a sensor for detecting the speed of the vehicle. For example, by detecting rotation of a speedometer cable or a gear of a transmission,
The speed of the vehicle is detected. Vehicle speed sensor 2
4 is also input to the input port 35. Further, the ignition switch 25 is a switch for detecting start / stop of the engine, and a start / stop signal generated by the ignition switch 25 is also input to the input port 35.

On the other hand, the output port 36 is connected to the fuel injector 12 and the ISCV 17 via the corresponding drive circuits 40 and 41 (only the fuel injector 12 and the ISCV 17 are shown in the figure). The ISCV 17 is provided for controlling the engine idling speed. The amount of bypass air flowing through the bypass passage 16 is controlled by the ISCV 17 so that the engine idling speed becomes the target speed during the engine idling operation. You.

Next, a control operation executed by the electronic control unit 30 in the internal combustion engine having the above hardware configuration will be described. Incidentally, the learning means (A1) described above, the determination means
(A4), initialization detection means (A5), judgment prohibition means (A6), and judgment prohibition canceling means (A7) are configured as software programs executed by the electronic control unit 30. Further, the throttle valve fully closed detection device includes the throttle valve 15,
It comprises a throttle opening sensor 22, a rotation speed sensor 23, a vehicle speed sensor 24, an ignition switch 25, an electronic control unit 30, and the like.

FIGS. 3 to 5 are flowcharts showing the operation of the throttle valve fully closed detecting device according to the first embodiment of the present invention.

First, a learning value (GTA) learning process executed by the throttle valve fully closed detection device will be described with reference to FIG. The learning processing shown in FIG. 3 corresponds to the processing of the learning means (A1).

When the learning process shown in the figure is started, first, in step 100, the CPU 34 reads the throttle opening (TA) output from the throttle opening sensor 22. In the subsequent step 102, the fully closed learning value (GTA) obtained in the previous learning process and stored in the backup RAM 33a is compared with the current throttle opening (TA) read in step 100.

If an affirmative determination is made in step 102, that is, if it is determined that the current throttle opening (TA) is smaller than the fully closed learning value (GTA),
In step 104, the value of the fully closed learning value (GTA) is replaced with the current throttle opening (TA), and a new RA value is set.
It is stored in M33.

The operation of the above process will be described with reference to FIG.

In the figure, the thin solid line indicates the throttle opening (TA), and the thick solid line indicates the fully closed learning value (GTA). As shown in the drawing, the fully closed learning value (GTA) is updated every time the throttle opening (TA) becomes smaller than the previously learned fully closed learning value (GTA). It has become. Finally, the fully closed learning value (GTA) converges to a value indicating the minimum valve opening of the throttle valve 15 (a value indicating a state equivalent to the fully closed state of the throttle valve 15 is referred to as a minimum valve opening MINTA). Becomes

Therefore, by comparing the minimum valve opening MINTA obtained by the learning process with the throttle opening (TA), it is determined whether or not the throttle opening (TA) is the minimum valve opening, that is, in the fully closed state. It can be determined whether there is.

Next, the initialization process will be described. FIG. 4 is a flowchart showing an initialization process performed when the fully closed learning value (GTA) is initialized. This initialization process is performed by the initialization detecting means (A5) and the determination prohibiting means (A6). Corresponding to

When the initialization process shown in the figure is started, first, at step 200, it is determined whether or not the initialization condition is satisfied. Here, the initialization condition is an engine condition such that the learned fully closed learning value (GTA) is erased, and more specifically, the storage content of the backup RAM 33a is erased by battery connection / replacement or the like. This is a case where an abnormality occurs in the storage contents of the backup RAM 33a due to an electric trouble or intrusion of large disturbance noise.

The electronic control unit 30 has a self-diagnosis function for detecting, when the battery power is stopped or an abnormality has occurred in the contents stored in the RAM 33 as described above. Therefore, the determination as to whether or not the initialization condition performed in step 200 is satisfied is made using this self-diagnosis function.

In step 200, when it is determined that the initialization condition is satisfied, specifically, when it is determined that the fully closed learning value (GTA) learned has been destroyed, the process proceeds to step 200. Proceeding to step 202, the fully closed learning value (G
TA) is performed.

In this step 202, the fully closed learning value (G
TA) as an initial value (G
TA0) is set. This initial value (GTA0) is set in consideration of the output variation of the throttle opening sensor 22, the assembly error, and the like . Therefore, the value is set to the actual minimum valve opening (MINTA) as shown in FIG. On the other hand, it is set to a considerably large value. In addition, this initial value (G
TA0) is stored in the ROM 32 of the electronic control unit 30, so that even if the battery is removed, its data will not be lost.

In step 202, an initial value (GTA0)
Is set, in the learning process described with reference to FIG.
In step 102, a new fully closed learning value is updated based on the initial value (GTA0) instead of the fully closed learning value (GTA).

Then, as the learning process proceeds, the fully closed learning value (GTA) finally reaches the minimum valve opening (MINT).
A), but the initial value (GT
Since A0) is a considerably large value with respect to the actual minimum valve opening (MINTA), it takes a long time for the fully closed learning value (GTA) to converge on the minimum valve opening (MINTA). In the example shown in FIG. 10A, the fully closed learning value (GT
Time A until A) converges to the minimum valve opening (MINTA)
I need one.

Therefore, until the time T1 elapses, if the fully closed determination is made based on the fully closed learning value (GTA), an erroneous determination may be made. Therefore, when the initialization of the fully closed learning value (GTA) is performed in step 202, step 204
, A full closing determination prohibition flag XGTAI for prohibiting the full closing determination is set (XGTAI = 1). If it is determined in step 200 that the initialization condition is not satisfied, it is not necessary to initialize the fully closed learning value (GTA), so that the initialization process is immediately terminated.

Next, the fully closed determination process will be described. FIG. 5 is a flowchart showing the fully closed determination processing, which corresponds to the processing of the determination means (A4) and the determination prohibition means (A6).

When the fully closed determination process shown in the figure is started, it is first determined in step 300 whether or not the execution of the fully closed determination process is permitted. More specifically, it is determined in step 204 of the initialization process described with reference to FIG. 4 whether the completely closed determination prohibition flag XGTAI is set.

If it is determined in step 300 that the execution of the fully closed determination process is not permitted, that is, if it is determined that the completely closed determination inhibition flag (XGTAI) is set (XGTAI = 1). Is that the fully closed learning value (GTA) is the minimum valve opening (MINTA) as described above.
Is not converged, and there is a possibility that an erroneous determination may be made in the fully closed determination, so that the fully closed determination after step 304 is not performed. Specifically, if a negative determination is made in step 300, the process proceeds to step 302, where the CPU 34 determines that the throttle valve 15 is not in the fully closed state (non-fully closed), and resets the fully closed flag (WIDL). (WIDL = 0).

On the other hand, in step 300, the totally closed judgment prohibition flag XGTAI is reset (XGTAI).
= 0), the fully closed determination after step 304 is performed.

In the fully closed determination processing, first, at step 304, the throttle opening (TA) read this time is compared with a fully closed determination value. Here, the fully closed determination value is a value obtained by adding a dead zone (DELTA) set in consideration of a sensor error or the like to a fully closed learning value (GTA). If it is determined in step 304 that the currently read throttle opening (TA) is larger than the fully closed determination value (GTA + DELTA), the currently read throttle opening (TA) is set to the minimum valve opening. Since it is not MINTA, the process proceeds to step 302, where the CPU 34 determines that the throttle valve 15 is not in the fully closed state (non-fully closed) and resets the fully closed flag (WIDL) (WIDL = 0).

On the other hand, in step 304, the throttle opening (TA) read this time is set to the fully closed judgment value (GTA).
When it is determined that the throttle opening is equal to or smaller than (+ DELTA), the throttle opening (TA) read this time is the minimum valve opening (MINTA) or a smaller valve opening. Therefore, if an affirmative determination is made in step 304, the process proceeds to step 306, in which the CPU 34 determines that the throttle valve 15 is in the fully closed state, and sets a fully closed flag (WIDL) (WIDL = 1). Therefore,
Various control processes (for example, fuel cut process) executed when the throttle valve 15 is fully closed can be executed based on the set state of the fully closed flag (WIDL).

Next, the resetting process of prohibiting the determination of the fully closed state will be described. FIG. 6 is a flowchart showing the reset processing of the totally closed judgment prohibition, which corresponds to the processing of the judgment prohibition canceling means (A7).

When the reset processing shown in the figure is started, it is determined in step 400 whether or not the reset condition is satisfied. The process of step 400 is a process of determining whether or not a condition sufficient to cancel the completely closed state prohibition state executed in step 300 (see FIG. 5) of the completely closed determination process is satisfied.

In this embodiment, the reset condition is satisfied when (1) the vehicle is stopped, (2) the engine speed is less than a predetermined value, and (3) a predetermined time has elapsed after the start. Is established, in other words, it is determined that the state is such that the full closure prohibition can be released. Here, the state in which the above conditions (1) and (2) are satisfied is a stable state in which the driver does not depress the accelerator pedal, and
When the condition (3) is satisfied, the fully closed learning value (GTA)
Is in a state in which a sufficient time (time T1 in the example of FIG. 10A) has passed for the value of to converge to the minimum valve opening (MINTA).

Accordingly, under the condition where the above conditions (1) to (3) are satisfied, the value of the fully closed learning value (GTA) converges to the minimum valve opening (MINTA), Even if the throttle valve 15 is fully closed based on the fully closed learning value (GTA), a highly accurate determination can be made. Therefore, if it is determined in step 400 that the above conditions (1) to (3) are satisfied, the process proceeds to step 402, and the totally closed determination prohibition flag (XGTAI) is reset (XGTAI = 0).

The condition (1) can be detected by the vehicle speed sensor 24, the condition (2) can be detected by the rotation speed sensor 23, and the condition (3) can be detected by an ignition switch. 25 and a timer device (not shown) built in the electronic control unit 30.

When the totally closed determination prohibition flag (XGTAI) is reset by the reset process shown in FIG. 6, an affirmative determination is made in step 300 of the fully closed determination process shown in FIG. The close determination will be performed.

Next, the effect of the throttle valve fully closed detection device according to the present embodiment will be described with reference to FIG.

In the throttle valve fully closed detection device according to this embodiment, when it is detected in step 200 of the initialization process that the fully closed learning value (GTA) has been initialized, the process proceeds to step 300 of the fully closed determination process. Fully closed learning value (GTA)
Is completely prohibited based on the above.

The fully closed learning value (GTA) is set to the initial value (GTA
0) and then the time (T1) until this initial value (GTA0) converges to the minimum valve opening (MINTA)
, The fully closed learning value (GTA) and the throttle valve 15
Is in the fully closed state (ie, the minimum valve opening MIN).
TA) is large. For this reason, when the fully closed determination is performed based on the fully closed learning value (GTA) while the initial value (GTA0) does not converge to the minimum valve opening (MINTA) as in the related art, as shown in FIG. However, even if the throttle valve 15 is not in the fully closed state, there is a possibility that the fully closed state may be determined.

In the present embodiment, as shown in FIGS. 10D and 10E, when the fully closed learning value (GTA) is initialized, the fully closed determination is prohibited, and the throttle valve Since the configuration is such that the throttle valve 15 is not in the fully closed state, it is possible to reliably prevent the erroneous determination that the fully closed determination is performed even though the throttle valve 15 is not in the fully closed state. Can be.

The prohibition of the fully-closed determination process is based on the minimum valve opening (MINT) indicating that the fully-closed learning value (GTA) indicates a fully closed state.
It is released after convergence to A). At this time, the release of the full-close determination prohibition is determined not based on the throttle opening signal (TA) output by the throttle opening sensor 22 but based on the engine state (vehicle speed, engine speed, time) of the internal combustion engine. Therefore, it is possible to accurately detect that the throttle valve 15 is in a fully closed state.

Therefore, after the learning value (GTA) is initialized, the fully closed determination process is prohibited until learning proceeds until the learning value (GTA) becomes equivalent to the actual fully closed valve opening. The erroneous determination of the closed state can be reliably prevented, so that various control processes performed when fully closed is detected can be accurately performed.

Next, a second embodiment of the present invention will be described. In the present embodiment, the throttle valve fully closed detection device according to the first embodiment is adapted to a fuel cut process performed during an idling operation. Hereinafter, the fuel cut process according to the second embodiment will be described with reference to FIGS.
Note that the hardware configuration of the throttle valve fully closed detection device according to the second embodiment is the same as the throttle valve fully closed detection device according to the first embodiment described with reference to FIG. Only the control operation performed by the electronic control unit 30 will be described.

The fuel cut performed during the idling operation is, for example, a process of temporarily stopping the fuel injection for the purpose of reducing fuel consumption when the accelerator pedal is released to decelerate at the time of high speed operation and the engine enters an idling state. Say.

This fuel cut is based on the throttle opening sensor output (TA) from the throttle opening sensor 22 and the engine state is under a predetermined state (this will be described later).
And when the throttle valve 15 is fully closed. Therefore, if the full closing of the throttle valve 15 is not accurately determined, the fuel cut is not properly performed, and the drivability is greatly reduced. Therefore, in the present embodiment, it is intended to optimize the fuel cut by accurately determining whether the throttle valve 15 is fully closed, thereby improving the drivability.

First, the initialization process will be described.

FIG. 7 is a flowchart showing the initialization processing. When the initialization processing shown in the figure is started, first, in step 500, it is determined whether or not an initialization condition is satisfied. Here, the initialization condition is an engine condition such that the learned fully closed learning value (GTA) is erased, and is the same as the condition described in step 200 of FIG. 4 in the first embodiment.

In step 500 , when it is determined that the initialization condition is satisfied, specifically, when it is determined that the fully closed learning value (GTA) that has been learned has been destroyed, the process proceeds to step 500 . Proceeding to step 502, the fully closed learning value (G
TA) is initialized, and an initial value (GTA0) is set as a fully closed learning value (GTA).

After the initialization of the fully closed learning value (GTA) is performed in step 502, in the following step 504, a fuel cut performed when the throttle valve 15 is fully closed (hereinafter referred to as a fully closed fuel cut). ). Specifically, a fully-closed fuel cut flag (XGTAFC) for instructing execution and stop of fuel cut is set (XGTAFC).
TAFC = 1). This fully closed fuel cut flag (XGTA
When FC) is set, execution of the fully-closed fuel cut is prohibited even if the engine state becomes the fuel cut execution condition.

As described above, when the affirmative determination is made in step 500, the execution of the fully closed fuel cut in step 504 is stopped because the fully closed learning value (GTA) is initialized as described above. After that, the fully closed learning value (GT
The accuracy of the fully closed determination performed on the basis of A) is reduced, and if the fully closed fuel cut is performed based on the result of the reduced fully closed determination, the fully closed fuel cut is not properly performed and the drivability is reduced. It is because it falls.

If a negative determination is made in step 500, the accuracy of the fully closed determination performed based on the fully closed learning value (GTA) is maintained at a high level. Since there is no problem even if the closed fuel cut is executed, the initialization processing is ended without executing the processing of steps 502 and 504.

Next, the fully closed fuel cut process will be described.

FIG. 8 is a flowchart showing the fully-closed fuel cut process. When the fully-closed fuel cut process shown in the figure is started, first, in step 600, it is determined whether or not the execution condition of the fully-closed fuel cut (shown as F / C in the figure) is satisfied. The execution condition of the fully-closed fuel cut determined in step 600 is not a condition specific to the present embodiment, but is generally determined when the fully-closed fuel cut is performed. Specifically, in step 600, it is determined (1) that the fully-closed state has been determined, (2) that the engine speed is equal to or higher than a predetermined value, and (3) that the dashpot control is not being performed. .

If an affirmative determination is made in step 600, that is, if it is determined that all of the above conditions (1) to (3) are satisfied, the process proceeds to step 602, where the fully closed fuel cut is performed. It is determined whether execution of the process is permitted. Specifically, in step 504 of the initialization process described with reference to FIG.
FC) is set.

When it is determined in step 602 that the execution of the fully-closed fuel cut is permitted, that is, when it is determined that the fully-closed fuel cut flag (XGTAFC) is reset (XGTAI = 0). The process proceeds to step 604 to set a fully closed fuel cut execution flag (XFCIDL) (XFCIDL = 1).

On the other hand, when it is determined in step 602 that the execution of the fully closed fuel cut is not permitted, that is, the fully closed determination prohibition flag XGTAI is set (X
If it is determined that GTAI = 1), the fully closed learning value (GTA) does not converge to the minimum valve opening (MINTA) as described above, and there is a possibility that an erroneous determination is made in the fully closed determination. Therefore, when the fully closed fuel cut is performed, drivability may be reduced. Therefore, when the negative determination is made in step 602, the fully-closed fuel cut processing is ended without executing the processing in step 604.

On the other hand, if a negative determination is made in step 600, that is, (1)
If it is determined that all or any of the conditions (3) to (3) are not satisfied, the process proceeds to step 606, and it is determined whether the fuel cut return condition is satisfied.

The process of step 606 is a process for judging whether or not the engine has become in a state that does not require the fully-closed fuel cut. Specifically, when the throttle valve 15 is in the open state (that is, when the fully closed determination is canceled) or when the engine speed is equal to or higher than a predetermined value, the CPU 34 determines that the engine state is fully closed. It is determined that the fuel cut is not required.

If an affirmative determination is made in step 606, the process proceeds to step 608 to reset the fully-closed fuel cut execution flag (XFCIDL) because the engine state does not require the fully-closed fuel cut. (X
FCIDL = 0). On the other hand, if a negative determination is made in step 606, the engine state is still a state in which the fully-closed fuel cut is required, so that the fully-closed fuel cut processing is terminated without executing the processing in step 608. .

The execution of the fully-closed fuel cut is performed in step 6
04 or step 608, the operation is executed based on the set state of the fully closed fuel cut execution flag (XFCIDL).

Subsequently, the fully closed fuel cut flag (XGTA
FC) reset processing will be described.

FIG. 9 shows a fully closed fuel cut flag (XGTAF).
It is a flowchart which shows the reset process of C). When the process shown in the figure starts, it is first determined in step 700 whether or not the execution of the fully closed determination process is permitted. The processing in step 700 is the same as step 300 in the fully closed determination processing described with reference to FIG. 5 in the first embodiment.
Specifically, it is determined whether or not the fully closed determination prohibition flag XGTAI (see step 204 in FIG. 4) is set.

If it is determined in step 700 that the execution of the fully closed determination process is permitted, the process proceeds to step 702, and the prohibition of the fully closed fuel cut is released (reset).
It is determined whether or not the reset condition to be satisfied is satisfied.
More specifically, the process of step 702 is a process of determining whether or not a condition sufficient to cancel the fully closed fuel cut prohibition state executed in step 602 (see FIG. 8) of the fully closed fuel cut process is satisfied. It is.

In this embodiment, the reset conditions are (1) that the vehicle is stopped, and (2) that the vehicle speed has become 15 km / h or more. If it is determined in step 702 that the conditions (1) and (2) are both satisfied, the process proceeds to step 704,
The fully closed fuel cut flag (X
GTAFC) (XGTAFC = 0). Accordingly, the prohibition of the fully-closed fuel cut is released, and the fully-closed fuel cut is performed based on the fully-closed determination result determined based on the fully-closed learning value (GTA).

Next, the effect of the above-described fully closed fuel cut processing according to the present embodiment will be described with reference to FIG.

In the throttle valve fully closed detection device according to this embodiment, when it is detected in step 500 of the initialization process that the fully closed learning value (GTA) has been initialized, step 602 of the fully closed fuel cut process is performed. , The execution of the fully closed fuel cut is prohibited.

As described above, during the time (T1) until the fully closed learning value (GTA) is initialized to the initial value (GTA0) and thereafter converges to the minimum valve opening (MINTA), an appropriate fully closed learning value (GTA) is obtained. The determination cannot be performed, and accordingly, the fully-closed fuel cut performed based on the fully-closed determination process cannot be properly performed. That is, as shown in FIG. 5C, there is a possibility that the fully-closed fuel cut may be performed even though the throttle valve 15 is not in the fully closed state.

In this embodiment, as shown in FIGS. 5F and 5G, the configuration is such that the fully closed fuel cut is inhibited when the fully closed learning value (GTA) is initialized. Therefore, it is possible to reliably prevent the full-closed fuel cut from being performed based on the erroneously determined full-closed determination, thereby improving drivability. The prohibition of the fully-closed fuel cut means that the fully-closed learning value (GTA) converges to the minimum valve opening (MINTA) indicating the fully-closed state, and the engine state becomes a state in which the fully-closed fuel cut should be performed. Will be released after Therefore, after the prohibition of the fully-closed fuel cut is released, the fully-closed fuel cut can be performed at an appropriate timing, and the fuel consumption reduction, which is an essential function of the fully-closed fuel cut, can be surely achieved.

[0089]

As described above, according to the present invention, after the learning value is initialized, the learning means determines the learning value until the learning value obtained by the learning means becomes equivalent to the actual fully closed valve opening. Since the fully closed determination process is prohibited, it is possible to prevent erroneous determination of the fully closed state of the throttle, and thus it is possible to accurately perform various control processes performed when the fully closed state is detected, and to appropriately perform engine control. Features such as

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is an overall configuration diagram of a fuel injection amount control device according to one embodiment of the present invention.

FIG. 3 is a flowchart showing a learning process executed in the first embodiment of the present invention.

FIG. 4 is a flowchart illustrating an initialization process performed in the first embodiment of the present invention.

FIG. 5 is a flowchart illustrating a fully closed determination process performed in the first embodiment of the present invention.

FIG. 6 is a flowchart illustrating a reset process executed in the first embodiment of the present invention.

FIG. 7 is a flowchart showing an initialization process executed in a second embodiment of the present invention.

FIG. 8 is a flowchart showing a fully-closed fuel cut process executed in a second embodiment of the present invention.

FIG. 9 is a flowchart illustrating a reset process executed in a second embodiment of the present invention.

FIG. 10 is a diagram for explaining the effects of the first embodiment and the second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine main body 12 Fuel injection valve 15 Throttle valve 22 Throttle opening sensor 23 Revolution speed sensor 24 Vehicle speed sensor 25 Ignition switch 30 Electronic control unit 32 ROM 33 RAM 34 CPU

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F02D 45/00 364 F02D 45/00 340 F02D 9/00

Claims (5)

(57) [Claims] A throttle opening sensor for outputting a throttle opening signal corresponding to the opening of the throttle valve of the internal combustion engine; and learning the throttle opening signal to indicate a minimum valve opening of the throttle valve. Throttle valve full-close detection of an internal combustion engine, comprising: learning means for sequentially updating a learning value and storing the learning value; and determination means for determining a throttle fully closed state based on the throttle opening signal and the learning value. In the device, initialization detecting means for detecting that the learning value has been initialized, and a throttle control executed by the determining means when the initialization detecting means detects that the learning value has been initialized. A determination prohibition unit that prohibits a process of determining a closed state; and a determination prohibition unit that prohibits the determination by the determination prohibition unit based on an engine state of the internal combustion engine when it detects that the throttle valve is in a fully closed state. A throttle valve full-close detection device for an internal combustion engine, comprising: a determination prohibition canceling means for canceling a stop. 2. A throttle valve for an internal combustion engine according to claim 1.
In the fully closed detection device, the determination prohibition canceling means is configured to determine whether the engine state of the internal combustion engine is such that the driver depresses an accelerator pedal.
The throttle valve
Is determined to be in the fully closed state.
A throttle valve fully closed detection device for an internal combustion engine. 3. A throttle valve for an internal combustion engine according to claim 2.
In the fully-closed detecting device, the stable state in which the accelerator pedal is not depressed means that the vehicle is stopped and the engine speed does not reach a predetermined value.
A slot of the internal combustion engine characterized by being full
Torle valve fully closed detector. 4. A throttle valve for an internal combustion engine according to claim 1.
In the fully- closed detection device, the determination prohibition canceling means is configured to determine whether the engine state of the internal combustion engine is equal to or smaller than the learning value within the minimum valve opening.
When it became a state in which between has passed when sufficient enough to bundle,
It is determined that the throttle valve has reached the fully closed state.
And a throttle valve fully closed detection device for an internal combustion engine. 5. A method according to claim 1 , wherein said throttle valve of said internal combustion engine has an opening degree.
Throttle opening sensor that outputs throttle opening signal
When, by learning the throttle opening signal, the slot
The learning value indicating the minimum valve opening of the torque valve is sequentially updated, and
A learning means for storing a value, a throttle opening signal based on the throttle opening signal and the learning value.
And a determination means for determining a fully closed state.
Initialization detection means for detecting that the learning value has been initialized in the rottle valve fully closed detection device
And that the learning value has been initialized by the initialization detecting means.
A fuel that, when known, stops injection of fuel into the internal combustion engine
The throttle valve is fully closed based on fuel cut prohibiting means for prohibiting the execution of the cut and the engine state of the internal combustion engine.
When it is detected that a substantial state has occurred, the fuel cut is prohibited.
A fuel tank for canceling the prohibition of the execution of the fuel cut by the stopping means.
Internal combustion engine provided with cut-out prohibition canceling means
Throttle valve fully closed detection device.