JP3936090B2 - Throttle control device for vehicle engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a throttle control device for a vehicle engine that controls the opening of a throttle valve in accordance with an operation amount of an accelerator pedal.
[0002]
[Related background]
As is well known, gasoline used in vehicle engines can be broadly classified into premium gasoline and regular gasoline according to octane number. In premium gasoline-designated vehicles, the engine is designed to maximize the knock resistance of the gasoline. High output is achieved by setting the compression ratio, ignition timing, etc. However, regular gasoline may be replenished even if it is a premium gasoline-designated car, so in such a case, the premium gasoline-designated car determines the presence or absence of knocking based on the detection information of the knock sensor, When knock determination is made, the ignition timing is retarded to suppress knocking.
[0003]
[Problems to be solved by the invention]
However, since the retard of the ignition timing causes a decrease in engine output, in order to obtain the same acceleration performance as when using premium gasoline, the driver needs to depress the accelerator more greatly. In other words, when the driver performs the same accelerator operation when using premium gasoline and when using regular gasoline, the acceleration performance of the vehicle when using regular gasoline (large retard) compared to when using premium gasoline (small retard) As a result, there is a problem that the accelerator operation is uncomfortable.
[0004]
An object of the present invention is to realize a throttle control of a vehicle engine capable of realizing almost the same acceleration of a vehicle with respect to an accelerator operation amount regardless of the type of fuel used, thereby improving the driver's accelerator operation feeling. To provide an apparatus.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the accelerator operation amount detecting means for detecting the accelerator operation amount, the throttle adjusting means for adjusting the throttle opening, and the throttle opening characteristic with respect to a preset accelerator operation amount The throttle control means for controlling the operation of the throttle adjustment means based on the accelerator operation amount detected by the accelerator operation amount detection means, and the ignition timing control means to learn from the engine knock occurrence state to suppress knocking. the more the learning value is the retard side to be applied to retard control Te, in which a throttle opening degree correction means for correcting the throttle opening by the throttle control means to the open side. For example, the lower the octane number of gasoline in use and the more likely knocking occurs, the more retarded learning value is learned by the ignition timing control means, and the ignition timing is retarded based on this learned value. Since the throttle opening is corrected to the open side in accordance with the learning value at this time, the decrease in engine output due to the retarded angle is compensated, and the engine output is maintained substantially equal even with the same accelerator operation amount. .
Further, the invention of claim 2 has a regular ignition timing map and a high-octane ignition timing map whose characteristics are set in advance corresponding to the type of gasoline used, and the basic ignition timing is determined by interpolating both ignition timing maps. The ignition timing control means for controlling the ignition timing of the engine based on the calculated basic ignition timing and the knock retard amount obtained from the engine knock occurrence state, and the interpolation coefficient applied to the interpolation processing of the ignition timing control means are knocked Learning means for learning based on the retard amount, accelerator operation amount detecting means for detecting the accelerator operation amount by the driver, throttle adjusting means for adjusting the throttle opening of the engine, regular ignition timing map, and high-octane ignition timing In order to compensate for the engine output disparity due to ignition timing control based on the map, A regular throttle opening map and a high-octane throttle opening map with the throttle opening characteristics set, and the target throttle opening is calculated by interpolating both throttle opening maps using an interpolation coefficient. And throttle control / correction means for controlling the operation of the throttle adjustment means based on the degree.
Therefore, the basic ignition timing is calculated by interpolating the regular ignition timing map and the high-octane ignition timing map, and the engine ignition timing is controlled based on the basic ignition timing and the amount of knock retard determined from the occurrence of knocking. In addition to being controlled by the means, the interpolation coefficient applied to the interpolation processing is learned by the learning means based on the knock retard amount. On the other hand, the regular throttle opening map and the high-oct throttle opening map are set so that the difference in engine output by the ignition timing control based on the regular ignition timing map and the high-octane ignition timing map can be compensated. The opening map is interpolated based on the interpolation coefficient to calculate the target throttle opening, and the operation of the throttle adjusting means is controlled by the throttle control / correction means based on the target throttle opening.
That is, the target throttle opening interpolation process is performed by applying the same interpolation coefficient as in the case of the basic ignition timing, and the regular throttle opening map and the high-octane throttle opening map used at this time are the regular ignition timing. The engine output difference is compensated for by the ignition timing control based on the timing map and ignition timing map for high-octane, so the engine output difference is compensated, and the engine is almost the same even with the same accelerator operation amount. Output is maintained.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is embodied in a throttle control device for a direct injection gasoline engine will be described.
In the overall configuration diagram of FIG. 1, reference numeral 1 denotes an in-cylinder injection gasoline engine for an automobile, and the combustion chamber 2 and the intake system are designed exclusively for in-cylinder injection. Since the engine 1 has a compression ratio and the like set on the premise of premium gasoline, use of premium gasoline is designated for a vehicle equipped with the engine 1. The cylinder head 3 of the engine 1 is provided with an electromagnetic fuel injection valve 5 together with a spark plug 4 for each cylinder, and high-pressure fuel supplied from a fuel pump (not shown) is supplied from the fuel injection valve 5 to the combustion chamber 2. It is designed to be injected directly into the inside.
[0007]
An intake port 6 is formed in the cylinder head 3 in a substantially upright direction, and an intake passage 7 is connected to the intake port 6. The intake passage 7 is provided with a throttle valve 8 for adjusting the amount of intake air, and the throttle valve 8 is driven to open and close by a motor 9. The intake air taken in from the intake passage 7 is introduced into the combustion chamber 2 from the intake port 6 through the throttle valve 8 as the intake valve 10 is opened, and fuel is injected from the fuel injection valve 5 into the intake air. Then, it burns by ignition of the spark plug 4.
[0008]
An exhaust port 15 is formed in the cylinder head 3 in a substantially horizontal direction, and an exhaust passage 16 is connected to the exhaust port 15. The exhaust gas after combustion is discharged into the atmosphere from the combustion chamber 2 through the exhaust port 15, the exhaust passage 16, a catalyst and a silencer (not shown) when the exhaust valve 17 is opened.
In the vehicle compartment, an input / output device (not shown), a storage device (ROM, RAM, BURAM, etc.) used for storing control programs and control maps, an ECU (engine) equipped with a central processing unit (CPU), a timer counter, etc. Control unit) 21 is installed and performs overall control of the engine 1. On the input side of the ECU 21 are an accelerator sensor 22 as an accelerator operation amount detection means for detecting an operation amount Acc of the accelerator pedal by the driver, a crank angle sensor 23 for outputting a crank angle signal at every predetermined crank angle, and fuel combustion. Along with this, various sensors such as a knock sensor 24 that detects vibration when knocking occurs are connected, and their detection information is input.
[0009]
The ignition plug 4 described above is connected to the output side of the ECU 21 via an igniter 25 and an ignition coil 26, and a fuel injection valve 5 is connected. Further, an ETV-CU (electronic throttle valve control unit) 27 is connected to the output side of the ECU 21, and a throttle position sensor 28 for detecting the opening θth of the throttle valve 8 is connected to the input side of the ETV-CU 27. The motor 9 is connected to the output side. In this embodiment, the ETV-CU 27 and the motor 9 function as throttle adjusting means.
[0010]
The ECU 21 controls the fuel injection valve 5 by determining a fuel injection mode (representing a process of performing fuel injection as described later) and a fuel injection time based on detection information from each sensor. Further, the basic ignition timing θB is determined based on the detection information from each sensor, and the ignition timing Tig is determined from the basic ignition timing θB, the knock retard amount θk corresponding to the occurrence of knocking, etc., and the igniter 25 is driven. Control. Further, the target average effective pressure Pe is determined based on the detection information from each sensor, and the target throttle opening degree Tθth is determined from the target average effective pressure Pe and the engine speed Ne and output to the ETV-CU27 side. The ETV-CU 27 controls the drive of the motor 9 based on the information.
[0011]
A map for determining various parameters used for the above-described fuel injection control, ignition timing control, and throttle opening control is stored in the storage device of the ECU 21. Here, the maps correlated with the gist of the present invention include maps used for ignition timing control and throttle opening control, so the setting status of these maps will be described below.
[0012]
FIG. 2 is a block diagram schematically showing functions of the throttle opening control and ignition timing control of the ECU 21. As shown in this figure, regarding ignition timing control, two types of maps MAP-θBP and MAP-θBR are stored to determine the basic ignition timing θB. These maps MAP-θBP and MAP-θBR are set according to the type of gasoline (premium gasoline and regular gasoline), not shown, but in the regular map MAP-θBR compared to the premium map MAP-θBP In order to suppress knocking, the basic ignition timing θBR on the more retarded angle side is determined.
[0013]
Regarding throttle opening control, one type of map MAP-Pe for determining the target average effective pressure Pe and two types of maps MAP for determining the target throttle opening Tθth using the target average effective pressure Pe. -θthP and MAP-θthR are stored. Similar to the maps MAP-θBP and MAP-θBR of the basic ignition timing θB described above, the maps MAP-θthP and MAP-θthR of the target throttle opening Tθth are set corresponding to the type of gasoline.
[0014]
Although not shown, the regular map MAP-θthR is set so as to determine a larger target throttle opening Tθth compared to the premium map MAP-θthP. It is set so as to be able to compensate for the decrease in engine output due to the retarded ignition timing in the maps MAP-θBP and MAP-θBR that determine the ignition timing θB.
[0015]
Next, the execution situation of throttle opening control executed by the throttle control device configured as described above will be described.
The knock interpolation coefficient Kk used during the previous operation is backed up in the storage device of the ECU 21, and when the engine 1 is started, the ignition timing control unit of the ECU 21 reads the knock interpolation coefficient Kk from the storage device. Then, an interpolation process between the maps MAP-θBP and MAP-θBR is executed according to the following equation (1) to obtain the basic ignition timing θB.
[0016]
θB = KkθBP + (1−Kk) θBR (1)
Here, θBP is the basic ignition timing obtained from the premium map MAP-θBP, and θBR is the basic ignition timing obtained from the regular map MAP-θBR. In each of the maps MAP-θBP and MAP-θBR, the basic ignition timings θBP and θBR are determined based on the engine speed Ne and the volumetric efficiency EV. Then, the ECU 21 calculates the ignition timing Tig by adding various correction amounts to the obtained basic ignition timing θB, and drives and controls the igniter 25 based on the ignition timing Tig.
[0017]
In parallel with this processing, the ECU 21 determines whether or not knocking has occurred based on the output signal of the knock sensor 24, and calculates the ignition timing Tig based on the knock retard amount θk set according to the determination result. Used for. That is, as is well known, when the output signal of the knock sensor 24 exceeds a predetermined threshold within the determination period determined immediately after ignition, it is considered that knocking has occurred, the knock retard amount θk is increased and the ignition timing Tig is delayed. Correct to the corner. By repeating this control, knocking is suppressed and the ignition timing Tig is held at a value immediately before the occurrence of knocking. In the present embodiment, the ECU 21 when executing the above retard processing functions as an ignition timing control means.
[0018]
Based on the setting state of the knock retard amount θk at this time, the ECU 21 executes the learning process for the knock interpolation coefficient Kk. The execution condition is set according to the fuel injection mode of the engine 1. Although not described in detail, in the cylinder injection type engine 1, in addition to the normal intake stroke injection mode, a compression stroke injection mode in which combustion at an extremely lean air-fuel ratio of about 40 (stratified combustion) can be executed, These fuel injection modes are switched based on the target average effective pressure Pe (representing a load) of the engine 1 and the engine speed Ne. Specifically, the compression stroke injection mode is executed in order to reduce fuel consumption in the low load / low rotation range, and the intake stroke injection mode is switched in the higher range, and the air-fuel ratio is made lean as the load and rotation speed increase. (Lean mode), theoretical air-fuel ratio (SF / B mode), and rich (O / L mode) are sequentially changed.
[0019]
The learning process of the knock interpolation coefficient Kk described above is executed in the intake stroke injection mode while avoiding the compression stroke injection mode with low load and low knock frequency. As shown in FIG. 3, a different knock learning determination value EV0 is set in advance as a function of the engine speed Ne according to the combination of each mode in the intake stroke injection mode and the correction direction of the ignition timing Tig based on the knock retard amount θk. Has been. At the time of execution of the intake stroke injection mode, the volumetric efficiency EV at that time is calculated in the ECU 21 based on the engine speed Ne and the output of an air flow sensor (air amount sensor) (not shown), and the calculated volumetric efficiency EV is knock learning determination. When the value is EV0 or more (EV ≧ EV0), it is determined that the learning condition is satisfied.
[0020]
When the learning condition is satisfied, the ECU 21 compares the knock retard amount θk at that time with a preset threshold value θ0, and when the knock retard amount θk is equal to or greater than the threshold value θ0 (θk ≧ θ0), the ECU 21 decreases the knock interpolation coefficient Kk. The basic ignition timing θB is corrected to the retarded angle side, and when the threshold is less than θ0 (θk ≦ θ0), the knock interpolation coefficient Kk is increased to correct the basic ignition timing θB to the advanced angle side. The calculated basic ignition timing θB is optimized. Therefore, the lower the octane number of gasoline in use and the more likely knocking occurs, the smaller the knock interpolation coefficient Kk is learned and the basic ignition timing θB on the retard side is determined, so the engine output decreases. become. Thus, the knock interpolation coefficient Kk can be regarded as an index indicating the type of gasoline used.
In the present embodiment, the ECU 21 for learning the knock interpolation coefficient K k based on the above knock retard amount θ k functions as a learning means.
[0021]
On the other hand, in the throttle opening control unit of the ECU 21, the target average is calculated according to the map MAP-Pe based on the accelerator operation amount Acc detected by the accelerator sensor 12 and the engine speed Ne calculated from the crank angle signal of the crank angle sensor 23. The effective pressure Pe is determined. Further, using the knock interpolation coefficient Kk, interpolation processing between the maps MAP-θthP and MAP-θthR is executed according to the following equation (2) to obtain the target throttle opening Tθth.
[0022]
Tθth = KkTθthP + (1-Kk) TθthR (2)
Here, TθthP is a target throttle opening degree obtained from the premium map MAP-θthP, and TθthR is a target throttle opening degree obtained from the regular map MAP-θthR. In each of the maps MAP-θthP and MAP-θthR, the target throttle opening Tθth is determined based on the engine speed Ne and the target average effective pressure Pe. The ECU 21 inputs the obtained target throttle opening Tθth to the ETV-CU 27, and the ETV-CU 27 performs feedback control based on the target throttle opening Tθth and the throttle opening θth detected by the throttle position sensor 28. Thus, the actual throttle opening degree θth is adjusted to the target throttle opening degree Tθth.
[0023]
As described above, the interpolation processing of the target throttle opening Tθth is performed by applying the knock interpolation coefficient Kk common to the case of the basic ignition timing θB. The maps MAP-θthP and MAP-θthR used at this time are the basic The characteristic is set so as to calculate a target throttle opening Tθth that is large by a considerable amount corresponding to the output decrease due to the retarded ignition timing θB.
[0024]
Therefore, for example, when using regular gasoline, the basic ignition timing θB is set to be considerably retarded in order to suppress knocking, but a large target throttle opening Tθth is set accordingly and the actual throttle opening θth is opened. Therefore, even if the accelerator operation amount Acc is the same, almost the same engine output is maintained. As a result, the same acceleration is realized by the same accelerator operation as when using premium gasoline, and the driver can operate the accelerator with the same feeling without feeling uncomfortable, and the accelerator operation feeling can be greatly improved.
[0025]
In this example, functions as ECU21 is, the throttle control means or throttle control and correction means when calculating the target throttle opening degree T.theta th based on the target average effective pressure P e obtained from the accelerator operation amount A cc or more, The ECU 21 when executing the interpolation processing between the maps MAP- θ thP and MAP- θ thR with the knock interpolation coefficient K k functions as throttle opening correction means or throttle control / correction means.
This is the end of the description of the embodiment. However, the embodiment of the present invention is not limited to this embodiment. For example, in the above-described embodiment, the throttle control device of the direct injection gasoline engine 1 is embodied. However, the present invention may be embodied in a throttle control device applied to a normal engine that injects fuel into the intake port.
[0026]
In the above embodiment, the target throttle opening Tθth is obtained by interpolating between the maps MAP-θthP and MAP-θthR using the knock interpolation coefficient Kk learned from the knock retard amount θk. The processing content is not limited as long as the target throttle opening Tθth that can compensate for the decrease in engine output due to the retarded ignition timing Tig generated by changing the fuel can be determined. Therefore, for example, the target throttle opening TθthP obtained from the premium map MAP-θthP is corrected to the open side by the correction coefficient set according to the knock retard amount θk without using the knock interpolation coefficient Kk. May be.
[0027]
【The invention's effect】
As described above, according to the throttle control device for a vehicle engine of the present invention, the acceleration performance of the vehicle is substantially equal to the accelerator operation amount regardless of the type of fuel used, and thus the driver's accelerator operation is achieved. A feeling can be improved.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing a throttle control device for a vehicle engine according to an embodiment.
FIG. 2 is a block diagram schematically showing functions of an ECU for throttle opening control and ignition timing control.
FIG. 3 is an explanatory diagram showing conditions for setting a knock learning determination value.
[Explanation of symbols]
1 Engine 9 Motor (Throttle adjusting means)
21 ECU (throttle opening correction means, ignition timing control means ,
(Throttle control means, throttle control / correction means )
22 Accelerator sensor (Accelerator operation amount detection means)
27 ETV-CU (throttle adjusting means)
Kk knock correction factor (control amount)

Claims (2)

An accelerator operation amount detection means for detecting an accelerator operation amount by the driver;
Throttle adjusting means for adjusting the throttle opening of the engine;
Throttle control means for controlling the operation of the throttle adjusting means based on the accelerator operation amount detected by the accelerator operation amount detecting means according to a throttle opening characteristic with respect to a preset accelerator operation amount;
In order to suppress knocking, the throttle opening by the throttle control means is corrected to the open side as the learning value applied to the retard control is learned from the engine knock occurrence state by the ignition timing control means and is retarded. A throttle control device for a vehicle engine, comprising: a throttle opening correction means that It has a regular ignition timing map and a high-octane ignition timing map whose characteristics are set in advance according to the type of gasoline used. The basic ignition timing and engine are calculated by interpolating both ignition timing maps. Ignition timing control means for controlling the ignition timing of the engine based on the amount of knock retard obtained from the knocking occurrence state of
Learning means for learning an interpolation coefficient applied to the interpolation processing of the ignition timing control means based on the knock retard amount;
An accelerator operation amount detection means for detecting an accelerator operation amount by the driver;
Throttle adjusting means for adjusting the throttle opening of the engine;
Regular throttle opening map and high octet with throttle opening characteristic with respect to accelerator operation amount set in advance so as to compensate for the difference in engine output due to ignition timing control based on the above regular ignition timing map and high-octane ignition timing map A throttle control map for controlling the operation of the throttle adjusting means based on the target throttle opening degree by calculating the target throttle opening degree by interpolating both throttle opening degree maps using the interpolation coefficient. Correction means
A vehicle engine throttle control apparatus comprising:

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