JP2839404B2 - Internal combustion engine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine control apparatus which determines timing control timings (ignition timings, etc.) of a plurality of cylinders based on a reference position signal corresponding to a predetermined crank angle, and more particularly to an internal combustion engine control system. The present invention relates to an internal combustion engine control device that realizes stabilization and efficiency of a combustion state by absorbing variations in timing control timing due to the above.

[0002]

2. Description of the Related Art In general, in an internal combustion engine having a crankshaft driven by a plurality of cylinders and a camshaft linked to the crankshaft, a timing control timing such as an ignition timing and a fuel injection timing of each cylinder is determined. The reference position signal synchronized with the engine rotation is used, and the angle detecting means for generating the reference position signal indicates that the reference position signal indicates a predetermined reference position corresponding to the crank angle (rotation angle of the crankshaft). Are provided on a crankshaft or a camshaft.

FIG. 4 is a functional block diagram showing a conventional internal combustion engine control device. In the figure, reference numeral 1 denotes an angle detecting means formed of a rotary plate provided on a cam shaft of an engine, for example, and a pulse-like reference position signal Tθ corresponding to a predetermined crank angle (reference position) of each cylinder in synchronization with engine rotation. Generate Usually, the reference position is set to, for example, B75 ° (75 ° before the top dead center) or B5 °.

[0004] Reference numeral 2 denotes various sensors for detecting operating conditions D such as an inflow air amount (throttle opening) indicating the engine load, rotation speed and intake air temperature, and 20 denotes a detected value I of ion current generated immediately after combustion of each cylinder. It is an ion current detecting means for feeding back. The ion current detection means 20 is provided in all cylinders or an arbitrary cylinder as needed.

A control unit 3 includes a microcomputer, and includes an ignition timing setting means 31 for calculating an ignition timing (timing control timing) for each cylinder based on the reference position signal Tθ and the operating condition D. Ignition timing setting means 31
Generates the control time Ta corresponding to the ignition timing, and when the ion current detection value I indicates the misfire level,
Take measures such as re-ignition control for the misfiring cylinder.

FIG. 5 is a circuit diagram showing the configuration of the ionic current detecting means 20. Reference numeral 21 denotes an ignition coil having a primary winding 21a and a secondary winding 21b. Reference numeral 22 denotes a primary coil based on an ignition pulse P corresponding to a control time Ta. a power transistor for cutting off the energizing current i ₁ of the windings 21a, the spark plug 23 is discharged by a high voltage generated in the secondary winding 21b, 24 ion ionic current i generated by the discharge explosion in the ignition plug 23 Is a DC power supply for discharging, 25 is a resistor connected in series to the DC power supply 24 to convert the ion current i into a voltage signal, and 26 is an output terminal for outputting an ion current detection value I consisting of a voltage signal. .

FIG. 6 is a waveform diagram showing the ion current i.
The primary current i _{1 is determined} by the ignition pulse P output at the ignition timing.
Is cut off and a discharge explosion occurs in the spark plug 23, the current value reaches the maximum level as shown in the figure.

Next, referring to FIGS. 5 and 6, FIG.
The operation of the conventional internal combustion engine control device shown in FIG. The ignition timing setting means 31 in the control device 3 uses the rising and falling timings of the reference position signal Tθ as the reference position, determines the ignition timing by referring to the map based on the operating condition D, and calculates the ignition timing from the reference position to the ignition timing. Is calculated.

The ignition timing setting means 31 confirms the fuel state of the cylinder in each ignition cycle based on the ion current detection value I from the ion current detection means 20, and the ion current detection value I is smaller than the reference level. In this case, the misfire of the corresponding cylinder is determined. If misfire is determined, the ignition control is performed again on the misfired cylinder, or
Take measures such as stopping fuel injection to prevent exhaust of unburned gas.

That is, in the cylinder of the ignition cycle, when the power transistor 22 is cut off by the ignition pulse P, a high negative voltage is applied to the ignition plug 23 connected to the secondary winding 21b, and the ignition plug 23 A discharge is generated between the electrodes and the mixture is ignited. Due to the explosive combustion at this time, ions due to ionization are generated in the explosive cylinder. Further, since a bias voltage is applied to the ignition plug 23 by the DC power supply 24, the electrode of the ignition plug 23 functions as an electrode for detecting the ion current i after discharging. Accordingly, electron transfer occurs due to the positive polarity bias of the DC power supply 24, an ion current i flows, and is converted into a detection value I by the resistor 25 and output.

However, the detected ion current value I is used only for misfire determination, and is not considered for use in feedback of ignition timing. For this reason, when the reference map of the ignition timing is not optimal due to variations in the engines, etc., optimal combustion is not always performed for each cylinder, and knocking occurs due to inappropriate ignition timing control. As a result, the ride comfort is reduced and the fuel efficiency is reduced.

[0012]

As described above, in the conventional internal combustion engine control apparatus, since the timing control timings such as the fuel injection and the ignition timing are determined based on the open loop control, the individual differences between the engines are determined. There has been a problem that it is not possible to absorb it and it is not possible to realize optimal timing control.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an internal combustion engine capable of absorbing variations in timing control timing due to individual differences between engines and realizing a stable and efficient combustion state. The aim is to obtain a control device.

[0014]

According to a first aspect of the present invention, there is provided an internal combustion engine control apparatus for controlling the operation of each cylinder in synchronization with the rotation of the engine.
An angle at which a reference position signal corresponding to a predetermined crank angle is generated
Detecting means, various sensors for detecting operating conditions of the engine,
Ion current for at least one of the cylinders
Current detection means for detecting the
Ignition timing and fuel injection timing for each cylinder based on the
Corresponding to the timing control timing including at least one of
Internal-combustion comprising timing setting means for setting a control time
In the engine control device, the detection value of the ion current detection means
Deviation calculating means for calculating a deviation related to the current value and the previous value; and correcting means for generating a correction signal when the deviation during steady operation of the engine exceeds a predetermined value. Thus, the control time is corrected.

According to a second aspect of the present invention, there is provided the internal combustion engine control device, wherein the deviation calculating means includes a current detection value holding means and a previous detection value holding means for holding current and previous detection values of the ion current; It includes a subtractor for calculating a deviation between the current detection value and the previous detection value.

According to a third aspect of the present invention, there is provided the internal combustion engine control device, wherein the deviation calculation means includes a current detection value holding means for holding the current detection value of the ion current, and an averaging process of the detection values up to this time. And a subtracter for calculating a deviation between the current detection value and the threshold. In addition, this departure
An internal combustion engine control device according to claim 4, wherein the deviation calculation means
Detects the ion current at a predetermined crank angle of the internal combustion engine.
It holds the output value. According to claim 5 of the present invention,
In such an internal combustion engine control device, the deviation calculation means may include an ion current
Holds the peak value of the detection value. In addition, this departure
An internal combustion engine control device according to claim 6, wherein the deviation calculation means
Holds the integrated value of the ion current detection value.
You.

[0017]

According to the first aspect of the present invention, in view of the fact that the detected value of the ion current corresponds to the combustion state, when the detected value of the ion current during steady operation fluctuates by a predetermined value or more, the fluctuation of the detected value is reduced. Combustion is stabilized so that the amount is within a predetermined range.

According to a second aspect of the present invention, the configuration is simplified by using the previous detected value as a reference for the detected value.

Further, in claim 3 of the present invention,
The threshold at which the lumber was absorbed was used as the reference for the detection value.
The use improves the reliability of the correction control.
According to a fourth aspect of the present invention, a predetermined crank angle is set.
By holding the detected value of the ion current in
Improve control of combustion efficiency. Claims of the present invention
In 5, the peak value of the detected value of the ion current is held.
By doing so, the control of combustion stabilization is particularly improved.
According to a sixth aspect of the present invention, there is provided a method for detecting an ion current.
Maintaining the integral of the value, especially for controlling the combustion limit
To be good.

[0020]

[Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. FIG.
FIG. 1 is a functional block diagram showing one embodiment of the present invention;
1, 2 and 20 are the same as described above. 3A and 31
A corresponds to the control device 3 and the ignition timing setting means 31, respectively.

The control device 3A includes a current detection value holding means 32 and a previous detection value holding means 33 for holding the current and previous detection values In and In _-1 of the current and previous ion currents, respectively. _The ignition timing setting means 31A includes a subtractor 34 for calculating a deviation ΔI from _-1 and a correction means 35 for generating a correction signal C when the deviation ΔI during a steady operation of the engine exceeds a predetermined value. The control time Ta is corrected based on the correction signal C.

The current detection value holding means 32, the previous detection value holding means 33, and the subtractor 34 constitute a deviation calculating means for obtaining a deviation ΔI of the ion current detection value I. Also, in this case, the present detection value holding means 32 takes in the reference position signal Tθ and the operating condition D, and when the operating condition D indicates a steady operation state,
The detected value I at the predetermined crank angle (A10 °) is now the detected value In.
And at the time of reading the next detection value I, it is input to the previous detection value holding means 33 as the previous detection value In _-1 .

FIG. 2 shows the detected values In and I of the ion current i.
It is a waveform diagram which shows n- ₁ . The detection value holding means 32 this time includes
As shown, the crank angle θp corresponding to the peak of the ion current i is set in advance, and the ion current i at the crank angle θp is determined by the current detection value In and the previous detection value I
It will be sequentially detected as n- ₁ .

Next, the operation of the embodiment of the present invention shown in FIG. 1 will be described with reference to FIG. Normally, the ignition timing setting means 31A in the control device 3A
The control time T based on the reference position signal Tθ and the operating condition D
a is calculated.

On the other hand, the current detection value holding means 32 having a steady operation determination function determines whether or not the vehicle is in a steady operation based on an air flow sensor signal, a cranking signal, and the like included in the operating condition D. If it is determined that the vehicle is in a steady operation, the detection value I at the predetermined crank angle θp is held as the current detection value In, and when the next detection value I is held, the previous detection value In- _{1 is used} as the previous detection value In- _1. The value is held by the value holding means 33.

Subsequently, the subtractor 34 calculates the detected values In and I
The deviation ΔI of n _-1

ΔI = | In−In ₋₁ |

And input to the correction means 35. When the operating condition D indicates the steady operation, the correction means 25 having the steady operation determining function generates the correction signal C based on the deviation ΔI. That is, the deviation ΔI is compared with a predetermined value α, and ΔI>
In the case of α, the combustion is considered to be in an unstable state, and the correction signal C is input to the ignition timing setting means 31A.

When the correction signal C is input, the ignition timing setting means 31A corrects, for example, the next ignition timing of the corresponding cylinder by a predetermined amount on the advance side of the map value. If the correction signal C is also generated in the next ignition cycle, the next ignition timing is further corrected to a more retarded side than the map value by a predetermined amount. Hereinafter, the process is repeated by trial and error until the correction signal C is no longer generated while increasing the correction amount of the ignition timing alternately on the advance side and the retard side.

As a result, the deviation ΔI finally falls within the range of the predetermined value α or less, and optimal control becomes possible, and the combustion state of the engine is stabilized. At this time, since the deviation calculation means 32 to 34 and the correction means 35 in the control device 3A can be configured by software, the combustion state can be detected with a simple configuration without particularly complicating the configuration. Further, since the previous detection value holding means 33 can be constituted by a simple register function, the structure is further simplified.

On the other hand, in the case of a transient operation that is not a steady operation, the deviation ΔI increases regardless of the presence or absence of abnormal combustion. Therefore, it is desirable that the detection value holding means 32 and 33 and the correction means 35 do not operate. In the case of FIG. 1, during the transient operation, the operation of the current detection value holding unit 32 and the correction unit 35 is prohibited based on the operation condition D, so that the correction signal C is not generated.

In the above embodiment, the present detection value holding means is used.
32 is a detection value I at a predetermined crank angle θp to read useless, which is a detection value I and cylinder pressure of the ion current
In consideration of the similarity of the waveform outputs. For example, in
The value of the predetermined crank angle θp for extracting the output of the fuel engine
Is optimal around A20 °, which is on the retard side from top dead center TDC.
The detected value of the ion current obtained at this crank angle position
It is easily understood experimentally that the variation of I is minimal.
ing. This is particularly effective for controlling combustion efficiency.
is there. Also, the peak value of the detected value I of the ion current is read and
May be retained. In this case, between the burning rate and the peak value
It is a known fact that a strong correlation between
Is suitable for detecting the combustion speed,
It is effective for stabilization control. Also, instead of the peak value,
Alternatively, the integrated value of the detected value I of the current may be read and held.
In this case, a strong correlation between the success or failure of the combustion and the integrated value was found.
It is a well-known fact that, in particular,
Suitable for controlling combustion limits.
You. Further, the ion current detection means 20 may be provided for each cylinder or may be provided only for a representative specific cylinder.

Although the case where the timing control timing is the ignition timing has been described as an example, it is needless to say that the present invention can be applied to other timing control timings, for example, the fuel injection timing, and the same operation and effect can be obtained. Also, although the case has been shown where both the detection value holding means 32 and the correction means 35 have a steady operation determination function this time, the steady operation determination function is provided in at least one of the deviation calculation means 32 to 34 or the correction means 35. It should just be.

Embodiment 2 FIG. Further, in the above-described embodiment, the previous detection value holding means 33 is provided in the deviation calculation means, and the previous detection value In _-1 is used as the reference value for determining the fluctuation of the current detection value In, but as shown in FIG. May be used as a threshold Ir obtained by averaging the detected values of the above. In FIG. 3, reference numeral 36 denotes a threshold calculating means for calculating a threshold Ir based on the averaging process of the detected values I up to this time.

In this case, the threshold calculating means 36
A threshold Ir is calculated by averaging the detected values I within a predetermined period during steady operation, and the threshold Ir is input to the subtractor 34 as a reference value. Therefore, highly reliable ignition timing correction can be performed based on the highly reliable threshold Ir in which the variation of the detected value I for each ignition cycle has been absorbed.

[0036]

As described above, according to the first aspect of the present invention, the current value and the previous value of the detected value of the ion current detecting means are changed.
A deviation calculating means for obtaining a related deviation; and a correcting means for generating a correction signal when the deviation during a steady operation of the engine exceeds a predetermined value, wherein the timing setting means corrects the control time based on the correction signal. Thus, there is an effect that a variation in timing control timing due to individual differences between the engines is absorbed, and an internal combustion engine control device that realizes a stable and efficient combustion state is obtained.

According to a second aspect of the present invention, the deviation calculation means includes a current detection value holding means and a previous detection value holding means for holding current and previous detection values of the ion current; A subtractor for calculating a deviation from the previous detection value, and the previous detection value is used as a reference for the detection value. There is an effect that the device can be obtained.

According to a third aspect of the present invention, the deviation calculation means includes a current detection value holding means for holding the current detection value of the ion current, and a threshold value based on an averaging process of the detection values up to this time. And a subtractor for calculating a deviation between the current detection value and the threshold, and the threshold in which the variation has been absorbed is used as a reference for the detection value. Thus, there is an effect that an internal combustion engine control device which realizes the internal combustion engine and improves the reliability of the correction control can be obtained.

Further , according to the fourth aspect of the present invention, the deviation performance
Calculating means for calculating the ion voltage at a predetermined crank angle of the internal combustion engine.
Since the flow detection value is retained, especially for improved combustion efficiency
The effect of obtaining an internal combustion engine control device with good control of
is there.

Further , according to the fifth aspect of the present invention, the deviation performance
Calculation means holds the peak value of the ion current detection value.
Internal combustion with particularly good control of combustion stabilization
There is an effect that an engine control device can be obtained.

Further , according to the sixth aspect of the present invention, the deviation performance
Calculation means, to hold the product fraction value of the detection value of the ion current
Internal combustion engine with particularly good control of combustion limits
There is an effect that a control device can be obtained.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a first embodiment of the present invention.

FIG. 2 is a waveform diagram showing an ion current for explaining the operation of the deviation calculating means in FIG.

FIG. 3 is a functional block diagram showing a second embodiment of the present invention.

FIG. 4 is a functional block diagram showing a conventional internal combustion engine control device.

FIG. 5 is a circuit diagram showing a general ion current detecting means.

FIG. 6 is a waveform diagram showing a general ion current.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Angle detection means, 2 various sensors, 20 ion current detection means, 31A ignition timing setting means (timing setting means), 32 current detection value holding means, 33 previous detection value holding means, 34 subtractor, 35 correction means, 36 threshold Calculation means, C correction signal, D operating condition, i
Ion current, I ion current detection value, In current detection value, In _-1 previous detection value, Ir threshold, ΔI
Deviation, Tθ Reference position signal, Ta control time.

Claims (6)

(57) [Claims] 1. An angle detecting means for generating a reference position signal corresponding to a predetermined crank angle of each cylinder in synchronization with rotation of an engine, various sensors for detecting operating conditions of the engine, and at least one of the cylinders containing an ion current detecting means for detecting an ion current for one cylinder, on the basis of the reference position signal and the operating conditions, at least one of ignition timing and fuel injection timing of each of the cylinders
The internal combustion engine controller that includes a timing setting means, the setting the control time corresponding to the non-timing control time, the current value and the previous value of the detected value of the ion current detecting means
Deviation calculation means for obtaining a related deviation; and correction means for generating a correction signal when the deviation exceeds a predetermined value during steady operation of the engine, wherein the timing setting means is based on the correction signal. An internal combustion engine control device, wherein the control time is corrected. 2. The apparatus according to claim 1, wherein said deviation calculating means includes a current detection value holding means and a previous detection value holding means for holding current and previous detection values of said ion current, and a deviation between said current detection value and said previous detection value. 2. The internal combustion engine control device according to claim 1, further comprising a subtractor that calculates 3. The deviation calculation means includes a current detection value holding means for holding a current detection value of the ion current, a threshold calculation means for calculating a threshold based on an averaging process of the detection values up to this time, 2. The internal combustion engine control device according to claim 1, further comprising a subtractor for calculating a deviation between the present detection value and the threshold. 4. The internal combustion engine control device according to claim 2, wherein said deviation calculating means holds a detected value of an ion current at a predetermined crank angle of said internal combustion engine. 5. The apparatus according to claim 2, wherein the deviation calculating means holds a peak value of the detected value of the ion current.
Or the internal combustion engine control device according to claim 3. 6. The internal combustion engine control device according to claim 2, wherein said deviation calculating means holds an integrated value of the detected value of said ion current.