JP2001115876A - Throttle control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rapidly adjust actual engine torque to a value approximately equal to a demand engine torque by accurately estimating and calculating actual engine torque. SOLUTION: This throttle control device comprises an electronic throttle 3 to control an opening regardless of an accelerator pedal 1; and a variable valve timing device 6. When a throttle opening correction amount Δθ is varied based on a deviation ΔT between the actual engine torque T2 and a demand engine torque T1, the actual engine torque T2 is calculated based on the lead angle of the variable valve timing device 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a throttle control device for an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, an internal combustion engine provided with an electronic throttle whose opening can be controlled independently of an accelerator pedal, and which changes a throttle opening correction amount based on a deviation between an actual engine torque and a required engine torque. Is known. An example of this type of throttle control device for an internal combustion engine is disclosed in, for example, JP-A-8-128344.
Is described in Japanese Patent Application Publication No. JP-A-8-12834
In the throttle control device for an internal combustion engine described in Japanese Patent Application Laid-Open No. 4 (1999) -1995, the actual engine torque can be made closer to the required engine torque by correcting the throttle opening.

[0003]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No. 8-
In the throttle control device for an internal combustion engine described in Japanese Patent No. 128344, the advance amount of the variable valve timing device is not considered when estimating and calculating the actual engine torque. That is, even if the advance amount of the variable valve timing device changes, the actual engine torque estimated and calculated does not change. On the other hand, in reality, when the advance amount of the variable valve timing device changes, the actual engine torque also changes. Therefore, in the throttle control device for an internal combustion engine described in Japanese Patent Application Laid-Open No. 8-128344, the actual engine torque is estimated and calculated as a uniform value even when the advance amount of the variable valve timing device is changed. Therefore, when the advance amount of the variable valve timing device is changed, the actual engine torque cannot be accurately estimated and calculated. As a result, the deviation between the actual engine torque and the required engine torque is incorrectly calculated, and therefore, the actual engine torque cannot be brought close to the required engine torque.

[0004] In view of the above problems, the present invention provides a throttle control device for an internal combustion engine, which can accurately estimate and calculate the actual engine torque so that the actual engine torque can quickly approach the required engine torque. With the goal.

[0005]

According to the first aspect of the present invention, there is provided an electronic throttle capable of controlling the opening degree independently of the accelerator pedal, and a deviation between the actual engine torque and the required engine torque. In a throttle control device for an internal combustion engine that changes a throttle opening correction amount based on a variable valve timing device, an internal combustion engine is configured to calculate an actual engine torque based on an advance amount of the variable valve timing device. Is provided.

According to the first aspect of the present invention, the actual engine torque is estimated and calculated based on the advance amount of the variable valve timing device. That is,
When the advance amount of the variable valve timing device changes, the estimated and calculated actual engine torque changes according to the change of the advance amount of the variable valve timing device. Therefore, the actual engine torque can be accurately estimated and calculated according to the advance amount of the variable valve timing device. Therefore, the deviation between the actual engine torque and the required engine torque can be accurately calculated, and as a result,
The actual engine torque can be quickly brought close to the required engine torque.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a first embodiment of a throttle control device for an internal combustion engine according to the present invention. In FIG. 1, 1 is an accelerator pedal, 2 is an intake passage, 3 is an electronic throttle whose opening can be controlled independently of the depression amount of the accelerator pedal 1, 4 is an internal combustion engine main body, and 5 is an exhaust passage. 6 is a variable valve timing device (VVT) for changing the valve timing and valve lift of intake and exhaust valves in the internal combustion engine body 4, 7 is a vehicle speed sensor, 8 is an accelerator opening sensor, and 9 is an engine speed sensor. 10 is E
CU (electronic control unit).

FIG. 2 is a flowchart showing the throttle opening correction at the time of acceleration by the throttle control device for an internal combustion engine according to the present embodiment. This throttle opening correction during acceleration is
It is executed at predetermined time intervals during the engine acceleration operation. When this routine is started, first, in step 201, the vehicle speed detected by the vehicle speed sensor 7 is read. Next, at step 202, the accelerator opening detected by the accelerator opening sensor 8 is read. Then step 20
In step 3, the required engine torque T1 is calculated from the vehicle speed read in step 201, the accelerator opening read in step 202, and a map showing the relationship between the accelerator opening and the required engine torque T1. FIG.
FIG. 4 is a diagram showing a relationship between a vehicle speed, an accelerator opening, and a required engine torque T1 recorded in a map used in FIG. More specifically, FIG. 3A is a diagram illustrating a relationship between the vehicle speed and the required engine torque T1 ′, and FIG. 3B is a diagram illustrating a relationship between the accelerator opening and the required engine torque T1 ″. As shown in (1), the required engine torque T1 increases as the vehicle speed increases, and also increases as the accelerator opening increases.
Is obtained by T1 = T1 ′ + T1 ″. Alternatively, a two-dimensional map of vehicle speed and accelerator opening may be used.

Returning to FIG. 2, in step 204, the engine speed detected by the engine speed sensor 9 is read. Next, at step 205, the VVT advance amount is read. Next, in step 206, step 203
Required engine torque T1 calculated in step 20 and step 20
4, the VVT advance amount read in step 205, and a map showing the relationship between these values and the basic throttle opening θ1.
1 is calculated. FIG. 4 is a diagram showing the relationship among the required engine torque T1, the engine speed, the VVT advance amount, and the basic throttle opening θ1 recorded in the map used in step 206. 4A shows a relationship between the required engine torque T1 and the basic throttle opening θ1, and FIG. 4B shows a relationship between the engine speed and the basic throttle opening θ1. FIG. 4C is a diagram showing the relationship between the VVT advance amount and the basic throttle opening θ1. As shown in FIG. 4, the basic throttle opening θ1 is different from the required engine torque T
1 increases as the engine speed increases, decreases as the engine speed increases, and decreases as the VVT advance amount increases.

Returning to FIG. 2, in step 207, the engine load calculated from the accelerator opening detected by the accelerator opening sensor 8 is read. Next, at step 208, the fuel injection timing is read. Next, in step 209, the VVT read in step 205
Map showing the relationship between the advance amount, the engine load read in step 207, the engine speed read in step 204, the fuel injection timing read in step 208, and the actual engine torque T2. From this, the actual engine torque T2 is calculated. FIG. 5 is a view showing the relationship among the VVT advance amount, the engine load, the engine speed, the fuel injection timing, and the actual engine torque T2 recorded in the map used in step 209. 5A shows a relationship between the VVT advance amount and the actual engine torque T2, FIG. 5B shows a relationship between the engine load and the actual engine torque T2, and FIG. (C) is a diagram showing the relationship between the engine speed and the actual engine torque T2,
FIG. 5D shows the fuel injection timing and the actual engine torque T2.
FIG. As shown in FIG. 5, the actual engine torque T2 increases as the VVT advance amount increases, and increases as the engine load increases. The actual engine torque T2 shows a maximum value at a predetermined engine speed and a predetermined fuel injection timing.

Returning to FIG. 2, in step 210, a deviation ΔT is calculated from the required engine torque T1 and the actual engine torque T2 (ΔT ← T1-T2). Next, at step 211, it is determined whether the deviation ΔT is greater than zero. If YES, that is, if the actual engine torque T2 is insufficient for the required engine torque T1, the process proceeds to step 212, and if NO, that is, if
When the actual engine torque T2 is not short of the required engine torque T1, the routine proceeds to step 213. In step 212, the deviation Δ calculated in step 210
From T and the map shown in FIG. 6, the throttle opening correction amount Δ
Calculate θ. On the other hand, in step 213, the throttle opening correction amount Δθ is made zero (Δθ ← 0). FIG. 6 shows the deviation Δ
4 is a map in which a relationship between T and a throttle opening correction amount Δθ is recorded. As shown in FIG. 6, the throttle opening correction amount Δ
θ increases as the deviation ΔT increases.

Referring back to FIG. 2, in step 214,
The throttle opening θ is corrected so as to be the sum of the basic throttle opening θ1 and the throttle opening correction amount Δθ (θ ← θ
1 + Δθ), and terminates this routine.

According to this embodiment, in step 209, the actual engine torque T2 is calculated based on the VVT advance amount.
Is estimated and calculated. That is, when the VVT advance amount changes, as shown in FIG. 5A, the estimated engine torque T2 changes with the change in the VVT advance amount. Therefore, in step 209, the actual engine torque T2 can be accurately estimated and calculated according to the VVT advance amount. Therefore, in step 210, the actual engine torque T2 and the required engine torque T1
Can be accurately calculated, and as a result,
The actual engine torque can be quickly brought close to the required engine torque. In other words, comfortable acceleration performance without delay during acceleration can be obtained.

Hereinafter, a second embodiment of the throttle control device for an internal combustion engine according to the present invention will be described. The configuration of the second embodiment is almost the same as that of the first embodiment shown in FIG. The throttle opening correction during acceleration by the throttle control device for the internal combustion engine of the present embodiment is substantially the same as that of the first embodiment shown in FIG. 2, but shown in FIG. 7 instead of step 209 in FIG. The routine is executed. FIG. 7 is a flowchart showing an actual engine torque T2 calculation routine of the present embodiment. As shown in FIG.
When this routine is started, first, in step 701, the ignition retard amount is read. Then step 702
Then, it is determined whether or not the VVT advance amount read in step 205 is equal to or greater than a predetermined threshold value VT1. If YES, proceed to step 703, NO
If so, the process proceeds to step 707. In step 703, it is determined whether the VVT advance amount read in step 205 is equal to or greater than a predetermined threshold value VT2. If YES, the process proceeds to step 704, and if NO, the process proceeds to step 710.

FIG. 8 is a diagram showing the relationship among the VVT advance amount, the engine torque, the ignition retard amount, and the ignition retard correction coefficient k. More specifically, FIG. 8A is a diagram showing a relationship between the VVT advance amount and the engine torque, and FIG. 8B is a diagram showing a relationship between the ignition retard amount and the ignition retard correction coefficient k. is there. FIG.
As shown in (a), in the present embodiment, engine torques corresponding to predetermined VVT advance amounts VT0, VT1, VT2, and VT3 are stored in the ECU in advance.

Returning to the description of FIG. 7, in step 704,
The coefficient mapINDEX used to calculate the actual engine torque T2 is set to 2 (mapINDEX ←
2). Next, at step 705, the threshold VT3 and the threshold V
The difference Xvt from T2 is calculated (Xvt ← VT3-V
T2). Next, at step 706, a difference ΔVT between the VVT advance amount and the threshold value VT2 is calculated (ΔVT ← VVT).
Advance amount-VT2).

On the other hand, at step 707, a coefficient mapIN used for calculating the actual engine torque T2 is set.
DEX is set to zero (mapINDEX ← 0). Next, at step 708, the difference Xvt between the threshold VT1 and the threshold VT0 is calculated (Xvt ← VT1-VT0). Next, at step 709, the difference ΔVT between the VVT advance amount and the threshold value VT0 is calculated (ΔVT ← VVT advance amount−VT
0).

In step 710, a coefficient mapIN used for calculating the actual engine torque T2 is set.
DEX is set to 1 (mapINDEX ← 1). Next, at step 711, a difference Xvt between the threshold value VT2 and the threshold value VT1 is calculated (Xvt ← VT2-VT1). Next, at step 712, a difference ΔVT between the VVT advance amount and the threshold value VT1 is calculated (ΔVT ← VVT advance amount−VT).
1).

Next, in step 713, step 70
4. Tlo is calculated from the coefficient mapINDEX set in step 707 or step 710 and the engine torque corresponding to the predetermined VVT advance amounts VT0, VT1, VT2, and VT3 stored in the ECU in advance, and then step 714 In the same manner, Thi is calculated. For example, in the example shown in FIG. 8A, the coefficient mapINDEX is set to 1 in Step 710 based on the VVT advance amount read in Step 205, and Xvt is calculated from VT1 and VT2 in Step 711, and Step 71
In step 2, ΔVT is calculated from the VVT advance amount read in step 205 and VT1. Step 7
In step 13, Tlo corresponding to VT1 is calculated, and in step 714, Thi corresponding to VT2 is calculated.

Returning to the description of FIG.
Then, Tlo calculated in step 713, Thi calculated in step 714, and
06, the actual engine torque T2 is calculated based on ΔVT calculated in step 709 or step 712 and Xvt calculated in step 705, step 708 or step 711 (T2 ← Tlo
+ (Thi-Tlo) * [Delta] VT / Xvt). Next, at step 716, the actual engine torque T2 calculated at step 715 is corrected based on the ignition retard correction coefficient k (T2 ← T2 × k). The ignition retard correction coefficient k is not shown based on the ignition retard amount read in step 701 and a map (FIG. 8B) showing the relationship between the ignition retard amount and the ignition retard correction coefficient k. Are calculated in the step.

In the above-described embodiment, the torque calculated in step 203 based on the vehicle speed and the accelerator opening is the required engine torque T1, but in other embodiments, the torque calculated in step 203 is In addition to the shaft torque, it is also possible to obtain the required engine torque T1 by correcting the propeller shaft torque on the basis of the drive motor torque, the power generation load, and the gear ratio (required engine torque T1 ← (propeller shaft torque). -Drive motor torque + load for power generation) / gear ratio).

In the above-described embodiment, not only when the deviation ΔT becomes zero but also when the deviation ΔT becomes negative, the throttle opening correction amount Δθ is uniformly set to zero at step 213. In the embodiment, when the deviation ΔT becomes negative, the throttle opening correction amount Δθ is set to a negative value, and a correction is performed to reduce the throttle opening. Can be prevented from becoming worse. Further, by executing such control not only at the time of engine acceleration operation but also at the time of engine steady operation, deterioration of fuel efficiency at the time of engine steady operation can be prevented.

[0024]

According to the first aspect of the present invention, the actual engine torque can be accurately estimated and calculated according to the advance amount of the variable valve timing device. Therefore, the deviation between the actual engine torque and the required engine torque can be accurately calculated, and as a result, the actual engine torque can be quickly brought closer to the required engine torque.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing a throttle opening correction at the time of acceleration by a throttle control device for an internal combustion engine according to the first embodiment.

FIG. 3 is a diagram showing a relationship between a vehicle speed, an accelerator opening, and a required engine torque T1 recorded in a map used in step 203;

FIG. 4 is a diagram showing a relationship among a required engine torque T1, an engine speed, a VVT advance amount, and a basic throttle opening θ1 recorded in a map used in step 206.

FIG. 5 is a diagram illustrating a relationship among a VVT advance amount, an engine load, an engine speed, a fuel injection timing, and an actual engine torque T2 recorded in a map used in step 209.

FIG. 6 is a map in which a relationship between a deviation ΔT and a throttle opening correction amount Δθ is recorded.

FIG. 7 is a flowchart illustrating an actual engine torque T2 calculation routine according to the second embodiment.

FIG. 8 is a diagram showing a relationship among a VVT advance amount, an engine torque, an ignition retard amount, and an ignition retard correction coefficient k.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Accelerator pedal 3 ... Electronic throttle 4 ... Internal combustion engine main body 6 ... Variable valve timing device T1 ... Required engine torque T2 ... Actual engine torque ΔT… Deviation Δθ… Throttle opening correction amount

Claims (1)

[Claims] 1. A throttle for an internal combustion engine, comprising: an electronic throttle capable of controlling an opening thereof independently of an accelerator pedal, wherein a throttle opening correction amount is changed based on a deviation between an actual engine torque and a required engine torque. A throttle control device for an internal combustion engine, wherein the control device includes a variable valve timing device, and calculates an actual engine torque based on an advance amount of the variable valve timing device.