JPH0794814B2 - Engine ignition control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an engine ignition control device.

[Conventional technology]

2. Description of the Related Art Conventionally, with the progress of engine electronic control technology, an engine speed and an engine load are detected, and a control amount related to ignition corresponding to the detected values (for example, ignition required for combustion per stroke is performed a plurality of times, so-called In the case of multiple ignition, an engine ignition control device is known in which the number of times of ignition and the ignition interval thereof are searched and determined from a previously stored ignition control amount map. As a conventional technique relating to this type of ignition control, there is, for example, the one described in Japanese Patent Laid-Open No. 60-204968.

[Problems to be Solved by the Invention]

It is an object of the present invention to provide an ignition control device for an engine, which employs an ignition control system which is an alternative to the conventional one, and can always perform optimal ignition efficiently with a minimum required energy in all operating conditions.

[Means for Solving the Problems]

A first invention is a capacitor charging circuit for charging a capacitor connected to a primary coil of an ignition coil, and a capacitor discharging circuit for discharging an electric charge charged in the capacitor to supply a primary current to the primary coil. An engine ignition control device of a capacitor discharge type for inducing a secondary current accompanied by spark discharge of an ignition plug in a secondary coil of an ignition coil by a current flowing through the primary coil, detecting an engine speed and an engine load. However, the optimum charge amount of the capacitor corresponding to the detected value is searched from a previously stored map to control the secondary current, and the required charge amount of the capacitor changes with time. Set the interrupt mode to know whether the engine is running or not, and set the engine speed and engine load during the interrupt mode. Means for detecting a parameter resulting from combustion of the engine, a means for determining whether the parameter is proper, and a minimum necessary capacitor charge amount for which the parameter is proper, the current corresponding value stored in the map. The capacitor charge amount to be obtained is increased or decreased by a predetermined minute unit, and the increased or decreased capacitor charge amount is set to the address corresponding to the corresponding engine speed and engine load in the map as the current capacitor charge amount. In addition, a writing means is provided, and the charging amount of the capacitor is set to be learned and controlled.

A second invention is an ignition control device for an engine, which controls a primary coil of an ignition coil to be turned on and off by a switching element to generate a high voltage for inducing spark discharge of an ignition plug in the secondary coil. A low voltage application device for applying a low voltage for sustaining a spark discharge is connected to the coil only while the primary coil is turned on, and the duration of this spark discharge is stored in a map in advance according to the engine speed and the engine load. A controller for controlling the on time of the primary coil and the low voltage application time according to the required spark discharge duration, and whether the required spark discharge duration changes with time. Set the interrupt mode to know whether the engine is running or not, and it is caused by engine combustion in the interrupt mode and engine combustion under engine load. A means for detecting a parameter, a means for judging whether the parameter is proper, a minimum necessary spark discharge duration for which the parameter is proper, and a current relevant spark discharge duration stored in the map. The spark discharge duration is increased or decreased by a predetermined minute unit by increasing or decreasing the ON time of the primary coil and the low voltage application time, and the increased or decreased spark discharge duration is the engine speed corresponding to the map. And a means for writing to the address corresponding to the engine load in place of the spark discharge duration up to now so that the spark discharge duration is set to be learned and controlled.

[Action]

Action of the first invention: In the capacitor discharge type ignition control device, the capacitor connected to the primary coil is charged, and the discharge control is performed at the ignition timing. Due to this discharge, a current (primary current) flows in the primary coil. ) Flows, whereby a high voltage is induced in the secondary coil, and a secondary current with spark discharge (ignition) flows between the electrodes of the spark plug, exceeding the dielectric breakdown voltage. This secondary current (ignition energy) changes by changing the charging potential (charging amount) of the capacitor.

In the present invention, the optimum ignition energy (here, the secondary current capable of achieving good combustion with the minimum necessary ignition energy) corresponding to the engine speed and the engine load is previously obtained from the viewpoint of combustion efficiency, and the optimum The minimum necessary optimum capacitor charge amount corresponding to the ignition energy is stored in the map for ignition control. Then, the engine speed and the engine load are detected, the optimum charge amount of the capacitor corresponding to the detected values is searched from the map, and the secondary current on the spark plug (secondary coil) side is controlled.

This secondary current (ignition energy), and hence the optimum amount of charge of the capacitor, may change as the engine performance changes over time. Therefore, an interrupt mode is set in the control program to know whether or not the optimum charge amount of the capacitor required during the operation of the engine is changing with time.

When this interrupt mode is entered, the engine speed in that mode and the parameters resulting from engine combustion under engine load are detected. The parameter resulting from this combustion (combustion parameter) serves as a guide for knowing that the secondary current, which is the basis of the ignition energy, and thus the capacitor charge amount changes over time and deviates from the optimum state, and an example is given. For example, there is an ignition delay time detected from the combustion light of the engine.

If the detected combustion parameter is not appropriate, it is assumed that the ignition control amount has changed over time, and the minimum necessary charge amount of the capacitor that can make the combustion parameter appropriate is set to the capacitor charge of the current corresponding map. It is calculated by increasing or decreasing the amount by a predetermined minute unit. As a result, the optimum capacitor charge amount that makes the combustion parameter appropriate is newly found, and this new capacitor charge amount is written to the address corresponding to the corresponding engine speed and engine load in the map, replacing the existing value. After that, the learning control related to ignition is performed by the new charge amount of the capacitor. Operation of the second invention: When the primary coil of the ignition coil is turned on by the switching element at the ignition timing, a high voltage that induces spark discharge of the ignition plug in the secondary coil when the primary coil is on (when the primary coil is energized). Occurs and a secondary current flows.

In this case, spark discharge (dielectric breakdown voltage) once to the spark plug
Then, if a low voltage is applied to the secondary coil while the primary coil is on, the spark discharge of the spark plug is continued. The duration of this spark discharge also affects combustion efficiency. Therefore, in the present invention, the minimum required optimum spark discharge duration corresponding to the engine speed and the engine load is obtained in advance in terms of combustion efficiency and stored in the ignition control map. Then, the engine speed and the engine load are detected, the spark discharge duration corresponding to the detected values is searched from the map, and the on time of the primary coil and the low voltage application time on the secondary coil side are controlled.

This spark discharge duration may change with changes in engine performance over time. Therefore, an interrupt mode for setting whether or not the optimum value of the spark discharge duration required during the operation of the engine is changing with time is set in the control program.

When this interrupt mode is entered, the engine speed in that mode and the parameters resulting from engine combustion under engine load are detected. The parameter resulting from this combustion (combustion parameter) serves as a guide for knowing that the spark discharge duration changes with time and deviates from the optimum state. For example, it is detected from the combustion light of the engine. There is an ignition delay time.

Then, when the detected combustion parameter is not appropriate, the current relevant spark discharge duration stored in the map is increased in increments of the primary coil on-time and the low-voltage application time in predetermined minute units. Increase or decrease and seek. As a result, the optimum spark discharge duration for which the combustion parameters are appropriate is newly found, and this new spark discharge duration is changed to the address corresponding to the corresponding engine speed and engine load in the map to the previous value. After that, the learning control regarding ignition is performed by the new spark discharge duration.

〔Example〕

 An embodiment of the present invention will be described with reference to FIGS.

Reference numeral 1 denotes a spark plug arranged in each cylinder of the engine, which is a microcomputer (ignition control unit; controller).
When an ignition signal of 2 is sent to the ignition circuit 3, a discharge for ignition occurs.

The ignition plug 1 has a built-in sensor for detecting combustion light, and the detected value is input to the microcomputer 2 via the detection circuit 4. The signal from the engine speed sensor 5 is also input to the microcomputer 2. In this embodiment, the control amount for ignition is optimized based on the detection value of the combustion light sensor.

FIG. 2 shows a specific example of the ignition circuit 3. Ignition circuit 3
Is a capacitor discharge type circuit. DC-DC converter
The potential from 10 charges the capacitor 11. And
When the ignition timing comes, a pulse as an ignition control signal is sent from the microcomputer 2 to the gate circuit 12. In the gate circuit 12, the discharge time is determined, a pulse is sent to the thyristor 13, the thyristor 13 is made conductive, and the electric charge of the capacitor 11 is discharged. Along with this discharge, a current flows in the primary coil 14 and a high voltage is generated in the secondary coil 15. When this high voltage exceeds the breakdown voltage of the spark plug 1, spark discharge is generated between the plug electrodes.

In this circuit, the capacitor 11
Targeting the charging potential (charging amount) of the capacitor 11 and controlling the charging amount of the capacitor 11 according to the engine speed and the engine load to finally control the secondary current (ignition energy) of the ignition coil. Thus, as will be described later, optimum ignition (in other words, ignition with good combustion efficiency) can always be efficiently performed with the minimum required energy.

When controlling the secondary current, the microcomputer 2
Values from given to the DC-DC converter 10 through a D / A converter 16, by changing the potential generated can be controlled by varying the charge amount C _E to the capacitor 11.

The ignition operation by the ignition circuit 3 will be described with reference to FIG. (A) in FIG. 3 (a) shows the micro computer 2.
(B) is a pressure waveform in the engine cylinder. In this embodiment, the thyristor 13
Is turned on at high speed based on the plurality of pulses shown in FIG.
By turning it off, the ignition can be performed multiple times in one stroke. FIG. 3 (b) shows the state of ignition a plurality of times. (A) in FIG. 3 (b) is a signal from the microcomputer 2 and corresponds to (a) in FIG. 3 (a). (B) of (b) is a pulse signal from the gate circuit 12.

(C) shows the potential of the capacitor 11. When the pulse of (b) is given to the thyristor 13, the potential of the capacitor 11 is lowered by discharging. At this time, the secondary coil 15
Then, the secondary current flows as shown in (d) and discharge occurs. The value of the secondary current, that is, the ignition energy can be changed as shown by the dotted line in (d) by changing the charging potential (charge amount) of the capacitor 11 as shown by the dotted line in (c).

FIG. 4 shows the construction of the combustion parameter detecting means used in the above-mentioned embodiment, that is, the sensor for detecting the combustion light. A quartz fiber 21 is provided at the center of the center electrode 20 of the spark plug 1 to guide combustion light to a photoelectric conversion circuit (detection circuit) 4 outside the plug. Further, the high voltage from the ignition circuit 3 is sent to the center electrode 20 via the lead portion 22.

FIG. 5 shows the detection values of the combustion light sensor when a plurality of ignition pulses are used in one combustion stroke, and the waveform of the combustion light when the ignition pulse as shown in (a) is given is It becomes like (a) 'in Figure (b). Further, the waveform of the combustion light when the engine performance deteriorates with time is as shown in FIG. 5B, (a) ″. Here, the waveforms of (a) ′ and (a) ″ are compared. Then, the waveform of (a) ′ is the ignition delay time.
t _d is small. t _d is the period from the beginning of the ignition pulse to the output rises ignition timing of the combustion light sensor. It is generally known that the smaller the t _{d, the} better the combustion. In other words, in this case, it can be said that (a) 'is better combustion than (a) ", because the growth of the flame kernel formed by the discharge is good.

When the number and interval of ignition pulses are the same, as shown in FIG. 6 (a), the operating point (capacitor charging potential C _EOPtt ) at which t _d can be minimized by the minimum required secondary current (ignition energy) of the ignition coil. ) Exists. This C _E, which is C _EOPt, is _stored in the engine ignition control map in relation to the engine speed and engine load. FIG. 6B shows this ignition control map, and C _E is retrieved from the memory of this map to perform ignition control.

FIG. 7 shows a flow chart for ignition control of this embodiment.
In the control example of FIG. 7, the rotation speed N is read and the ratio Qa / N with the air amount Qa is read as the load. And FIG. 6 (b)
From a map like this, search for C _E that matches the engine speed and engine load, and the microcomputer 2 outputs the corresponding C _E potential command to the DC-DC converter 10 via the D / A converter 16. Then, the DC-DC converter 10 changes the potential of the capacitor 11
C _E controlled. The ignition timing is determined by another flow.

FIG. 8 and FIG. 9 are interrupt modes for knowing whether or not the optimum minimum required capacitor charging potential C _E required during engine operation has changed over time. 8th
The figure shows the flow for obtaining the average value of 10 times of the engine speed in the interrupt mode and the parameter (here, ignition delay time t _d ) caused by the combustion of the engine under the engine load. _{Divide d} by 10 and average m _d
Ask for. The ignition delay time t _d is an average value because there is some cycle variation. Next, the C _E correction program is started by the flow chart in FIG. Leading the engine speed N and load Qa / N, the actual m _{d at} that time
To check whether m _d is within the proper range m ₁ <md <m ₂ . FIG. 10 (a) shows the C _E correction program following FIG.

First, make C _{E a} little smaller than C _E −α. The ignition delay time average value m _{d at} that time is read, and compared with the previous m _d old m
If there is no change in _d , the C _E decrease program is started, and if m _d is large, the C _E increase program is started.

Figure 10 (b) shows the C _E reduction program. Slightly smaller C _E and C _E-.alpha., compared to previous m _d old. Aruitoki the convergence state (Min) to m _d is not changed, yet, also reduced the C _E, to see if they can maintain a minimum m _d, C _E-.alpha.
And make it smaller. Eventually, when m _d is increased, As before C _E + alpha is the minimum necessary minimum ignition energy of the ignition delay time t _d (most combustion efficient state) ones, the C _E + alpha, the Engine condition N, Qa obtained from Fig. 9
The optimum C _E for / N is written in the corresponding storage unit of the ignition control map in place of the previous C _E.

Figure 10 (c) shows the C _E increase program. In this case the tenth
Since C _E is decreased and m _d is increased in the figure (a), the current C _E is increased to C _E + α here. If m _d is smaller than m _d old as a result of making it larger, it is further increased by α in order to confirm whether m _d becomes smaller even if C _E is increased. When m _d does not change to m _d old and enters the convergent state, it is useless to increase C _E any more. Therefore, the previous C _E is obtained by C _E −α, and this is obtained. The optimum C _E is written in the corresponding storage section of the map in place of the existing C _E. In this way, the required minimum ignition energy (capacitor charge amount) C _E that minimizes t _d is always obtained.

As described above, in the present embodiment, the ignition delay time is set as the combustion parameter by the change with time of the required ignition energy.
When t _d (average value m _d ) becomes incorrect, the ignition energy C _E is rewritten by learning, and a means for determining whether the combustion parameter necessary for this learning is appropriate,
The rewriting means of C _E is configured by the microcomputer 2.

FIG. 11 shows a learning control method for each cylinder. FIG. 11A shows the reference signal ref of the crank angle sensor 5.
Then, a pulse having a different length for each cylinder is output. This is shown in the figure below.
It is converted to a digital value such as R _{1 to} R ₄ and used for cylinder discrimination. The values of R _{1 to} R ₄ are automatically and time-sequentially input into the memory of the I / O address in the microcomputer 2 as shown in FIG. 11 (b). The C _E map of the corresponding cylinder is stored in the area of the address corresponding to the values of R _{1 to} R ₄ .

Figure 12 shows the C _E search method for each cylinder.

_First , read the memory contents (R _{1 to} R ₄ ) in the I / O address. Next, the parameters such as N and Qa / N are read. Next, the map of the address corresponding to the R value is searched, and the obtained C _E corresponding to N and Qa / N is output to the ignition circuit as a command signal. This makes it possible to perform optimum C _E control for each cylinder. In the case where the C _{E for} each cylinder deviates from the actual optimum C _E due to the change with time, FIG.
Map of the corresponding cylinder according to the flowchart shown in Fig. 10.
C _E is rewritten and C _E is learned for each cylinder.

Next, in place of the learning control method of C _{E in} the above embodiment, the fifth
The capacitor charge C _E such that the peak position Δθ _P of the detection value of the combustion light sensor shown in FIGS.
Learning (correction program) will be described. Δθ
_P is the crank angle from TDC (top dead center), and normally Δθ _P is about 15 °, which is the best combustion state.

FIG. 13 shows a flow chart for obtaining the optimum C _E based on Δθ _P. As in (a), the output value of the combustion light sensor is read by the ref interrupt. Next, the peak value is detected to obtain the peak position Δθ _P. This Δθ _P is temporarily stored. FIG. 13 (b) shows a flow of activating the _CE correction program by the timer interrupt.

If Δθ _P is within a certain range, for example, 12 <Δθ _P <16, C _E is not corrected. If it is out of the range, the _CE correction program is started. In this C _E correction program, incremental correction is performed in small units until C _E enters the proper range, and when it enters the proper range, the correction program is terminated and C _E is rewritten.
FIG. 14 (a) shows a C _E increase program in this case.

As described above, the value of C _E that makes Δθ _P optimal is learned.

The peak position of the combustion light as described above is the same as the peak position of the output value of the in-cylinder pressure sensor. Therefore, the value detected by the in-cylinder pressure sensor may be used as a parameter related to combustion. The parameter at this time is similarly the peak position Δθ _P of the in-cylinder pressure, and the control flow is the same as the above method based on the peak position of the combustion light. Further, a method of learning C _E may be adopted so that the pressure increase rate of the in-cylinder pressure becomes an appropriate value.

15 to 17 show an embodiment in which C _E is learned based on the detection value of the rotation speed sensor 5. FIG. 15 (a) shows the ref signal and the detection value of the rotation speed sensor. If the signal of the rotation speed sensor is processed at every 1 ° of crank angle to calculate the rotation speed, a fine output as shown in (a) can be obtained. Looking at this detected value, the value of the portion corresponding to the cylinder in which combustion is poor is decreasing. In the present embodiment, the C _E of the cylinder with poor combustion is improved and learned.

In FIG. 15 (b), the ref interrupt is used to store the cylinder discrimination signal R, obtain the average value N _m of the engine speed N between ref,
Store with R.

Next, as shown in FIG. 16 (a), N _m
Discriminates a cylinder that is lower than other cylinders, stores the corresponding cylinder number, and starts the _CE correction program.

In the C _E correction program of Fig. 16 (b),
Decrease C _E and determine if its N _m increases. If N _m is the same as before, the C _E decrease program is started, and if N _m is decreased, the C _E increase program is started.

The C _E loss program of FIG. 17 (a), while the N _m is maintaining the value of the same extent as the other cylinders continue to reduce C _E by microunits alpha. If N _m decreases, C _E + α before that is optimal
Written in place of the corresponding storage section of the map to C _E of until now as C _E.

The C _E increase programs FIG. 17 (b), the C _E increased by small units α until N _m is the same as the value of other cylinders, Tara same as summer stores C _E at that time. As described above, the learning control of C _E can be performed based on the signal of the rotation speed sensor 5.

18 and 19 show an example of the case where the combustion state is detected by the generated torque for each cylinder and C _E is learned and controlled. First
FIG. 18 (a) shows a torque detection method. A rotation detector 30 made of gears is provided at the front of the engine crankshaft 29, and a similar detector 31 is provided at the rear. The torque T is obtained from the phase difference Δθ between the outputs θ ₁ and θ ₂ of the rotation detector at this time.

FIG. 18 (b) shows the ref signal and the detected value of the torque T. Similar to the above example, the torque of the cylinder with poor combustion is lower than that of the other cylinders. By discriminating this cylinder, C _E is learned. The control method in this case is the same as the case of the rotational speeds shown in FIGS. 15 to 17, and N may be replaced with T.

In the example shown above, the combustion charge, the in-cylinder pressure, the rotation speed, the torque, etc. are used as parameters due to combustion, and the capacitor charge amount C _E of the capacitor discharge multiple ignition device is learned and controlled. _In addition to _E , the following control method may be used.

FIG. 19 shows an example of controlling the duration of spark discharge of the spark plug. FIG. 19 (a) shows the hardware configuration. A transistor (switching element) 43 is connected to the primary coil 41, and the transistor 43 is turned on and off according to a command from the microcomputer 2. When turned on, current flows through the primary coil (primary coil is on), 2
High voltage is generated in the secondary coil. DC-DC converter 40,
It is a low voltage application device that applies a low voltage for sustaining spark discharge only while the primary coil is on, and is connected to the secondary coil.

That is, once the voltage breakdown occurs in the plug 1, DC-DC
The spark discharge continues even at low voltage from converter 40.
If the DC-DC converter 40 is operated while the transistor 43 is on, that is, while the primary coil is on, the spark discharge is maintained for the on time. In this embodiment, the spark discharge duration t _S is stored in a map in advance according to the engine speed and the engine load, and the controller (microcomputer) 2 adjusts the primary discharge according to the required discharge duration t _S. It is set to control the coil control time and the low voltage application time on the secondary coil side.

This situation is shown in FIG. 19 (b).

FIG. 19 (a) shows an ignition timing command pulse, and this signal produces a pulse (b) which is turned on only for t _S and supplies it to the transistor 43. (C) shows the secondary current, and after the capacitive discharge (I), the dielectric discharge (II) occurs only for t _S.

The relationship between this t _S and the ignition delay time t _d is shown in FIG. When t _S increases, t _d decreases, and when t _S exceeds a certain value, it converges to a constant value. t _S when t _d starts to converge is the required minimum energy and maximum efficiency t _SOPt . Where t _S
Based on, learning control is performed so that t _SOPt is always t _S.

FIG. 20 shows a correction flow by learning t _S.

As can be seen from the characteristics of FIG. 20, it can be judged whether or not t _S is at t _SOPt by once reducing t _S as shown in FIG. 20 (a). At this time, if the ignition delay time t _d, which is a combustion parameter, increases, it is judged that the ignition delay time t _d is in the region shown in A of FIG. 20, and the t _S increasing program is started.
If t _d does not increase, it is judged that it is in the area B in FIG. 20, and the t _S decrease program is started.

The t _S increased program FIG. 21 (b), while t _d continues to decrease, increasing the t _S in minute units alpha. When t _S does not decrease, t _S at that time is stored as the optimum t _S.

The t _S reduction programs FIG. 21 (c), to reduce the t _S until t _d is increased, the corresponding memory section of the map the previous t _S-.alpha. as the optimal t _S when t _d is increased Write in place of the existing t _S.

This embodiment also can maintain a good combustion efficiency in each embodiment likewise minimum ignition energy described above, moreover, the actual shift in the optimum t _S and t _S until now aging occurs in t _S Even if it occurs, it is corrected by learning, so that good combustion efficiency can always be maintained with the minimum ignition energy.

FIG. 22 shows a method of restoration when soot is attached to the tip of the combustion light sensor and the output is reduced. 22 (a) shows the ignition pulse signal, and FIG. 22 (b) shows the output of the combustion light sensor. 22 (a)-(b), (i) shows the case where there is no change with time due to soot, and (ii) shows the case where soot adheres. In (ii), the output is reduced. here,
This soot is removed by a large amount of discharge.

The method is shown in FIG. 22 (b). Normal ignition is
Although it ends in the range of A of (a) (the latter half of the compression stroke), if a change with time is detected, ignition is continued for a longer time than that, for example, over the explosion stroke. 22 (b)-(b),
In the stroke (exhaust stroke) other than the compression stroke, multiple pulses for soot removal are output. In (b), soot removal pulse ignition has less influence on combustion.

FIG. 22 (c) shows how the spark plug is discharged. A discharge spark 51 is generated on the center electrode 20 from the cathode 50. At this time, since the quartz fiber 21 is located at the center of the center electrode 20, the spark passes through the fiber surface and the soot adhering to the surface is burned off. As a result, the change over time is
It is removed and the original output state is restored.

FIG. 23 shows a flow chart for performing pulse ignition for removing soot.

In FIG. 23 (a), it is determined whether or not the engine has been started, and when the warm-up operation is finished, the soot cleaning program is started each time.

FIG. 23 (b) shows a cleaning program. Here, it is judged whether it is the exhaust stroke, and if yes, the
Ignition is performed by outputting a multi-pulse like B in FIGS. 22 (b)-(b).

FIG. 23 (C) shows an example of another cleaning program. Judge whether it is ignition timing, and if yes,
22. Multi-pulses are output as shown in (b)-(a) of FIG. Soot is removed by the above flow.

FIG. 24 shows another method of activating a cleaning program. It is judged whether or not the engine is idling, and when the answer is YES, the ignition light intensity V _P as indicated by A in FIG. 22 (a)-(b) is detected. When this V _P is smaller than the reference value V ref, it is determined that soot has adhered and the cleaning program is activated. The cleaning program uses (b) or (c) in FIG.

FIG. 25 shows an example of the cleaning program in the ignition circuit shown in FIG.

When the cleaning program is started, at the ignition timing,
Set the discharge duration t _S to the maximum allowable value, Max · t _S ,
This is given to the transistor 43 of FIG. 19 (a), and discharge longer than usual is performed. This long discharge removes soot.

〔The invention's effect〕

According to the present invention, it is possible to always ignite with the optimum and minimum required energy in response to the change over time, and thus it is possible to realize both the demand for low fuel consumption and the improvement of drivability.

[Brief description of drawings]

FIG. 1 is a system diagram of engine ignition control according to an embodiment of the present invention, FIG. 2 is a configuration diagram of an ignition circuit used in the engine ignition control system, and FIG. 3 is an explanatory diagram showing its ignition operation.
FIG. 5 is a diagram showing a combination of an ignition plug and a combustion light sensor used in the above embodiment, and FIG. 5 is a relation between an ignition signal and a combustion light sensor and a relation between ignition energy (capacitor charge amount) C _E and ignition delay time t _d. 6 is an explanatory view of a map showing the characteristic showing the relationship between the engine load and the optimum C _E and the storing method thereof, FIG. 7 is a flowchart of the ignition control of the above-mentioned embodiment, and FIG. 8 is ignition. flowchart illustrating a method of obtaining the average value of the ignition delay, the flow chart Figure 9 is showing the activation of the C _E correction program, FIG. 10 is a flowchart showing a C _E correction program, the FIG. 11 of the cylinder C _E control method Fig. 12 is a flow chart showing the C _E search method for each cylinder.
FIG. 13 is a flow chart for performing C _E correction from the ignition peak position Δθ _P , FIG. 14 is a flow chart showing a C _E increasing program in C _E correction in FIG. 13, and FIGS. 15 to 17 are engine speed detections. Explanatory diagram showing an embodiment for learning C _E based on the value, FIG. 18 is an explanatory diagram showing an operation example in the case of performing combustion control by detecting the combustion state by the generated torque of each cylinder, FIG. 19 is FIG. 20 is a characteristic diagram showing the relationship between the dielectric discharge time t _S of the ignition coil and the ignition delay time, and FIG. 21 is t _{S in} the circuit configuration and operation waveform diagram of the ignition circuit in another embodiment of the present invention.
22 is a flow chart showing the correction program of FIG. 22, FIG. 22 is an explanatory view showing a cleaning method when soot adheres to the combustion light sensor, and FIGS. 23 to 25 are flow charts for executing the cleaning. 1 ... Ignition plug, 2 ... Microcomputer (ignition control controller), 3 ... Ignition circuit, 4 ... Combustion light sensor, 5 ... Crank angle sensor (engine speed sensor), 10 ... DC-DC Converter, 11 ... capacitor, 12
...... Gate circuit, 13 thyristor, 14 …… Primary coil, 15 …… Secondary coil, 16 …… D / A converter, 30,31 …… Torque detection sensor, 40 …… DC-DC converter ( Low voltage applicator), 41 ... primary coil, 42 ... secondary coil, 43 ... transistor (switching element).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F02P 15/10 301 D (56) Reference JP-A 64-35081 (JP, A) JP A 64-19174 (JP, A) JP-A-63-302163 (JP, A) JP-A-63-195363 (JP, A) Actually developed Shou 60-61481 (JP, U)

Claims (2)

[Claims] 1. A capacitor charging circuit for charging a capacitor connected to a primary coil of an ignition coil, and a capacitor charging circuit for discharging an electric charge charged in the capacitor to provide a primary coil to the primary coil.
A capacitor discharge circuit for supplying a secondary current, wherein the secondary coil of the ignition coil is induced by a current flowing through the primary coil to induce a secondary current accompanied by spark discharge of an ignition plug. An engine speed and an engine load are detected, an optimum charge amount of the capacitor corresponding to the detected values is searched from a map stored in advance to control the secondary current, and A means for setting an interrupt mode for knowing whether or not the charge amount has changed over time during engine operation, and detecting a parameter resulting from engine combustion in the interrupt mode and engine combustion under engine load; Means for determining whether or not the parameters are appropriate, and a minimum necessary capacitor charge required for the parameters to be appropriate. The amount of electricity is obtained by increasing or decreasing the current corresponding capacitor charge amount stored in the map by a predetermined minute unit, and the increased or decreased capacitor charge amount is applied to the corresponding engine speed, engine An ignition control device for an engine, comprising: means for writing to a load-corresponding address in place of the current charge amount of the capacitor, so that the charge amount of the capacitor is learned and controlled. 2. An ignition control device for an engine, wherein a primary coil of an ignition coil is turned on / off by a switching element to generate a high voltage that induces spark discharge of an ignition plug in the secondary coil. A low voltage applicator that applies a low voltage for sustaining spark discharge only while the primary coil is turned on is connected to the map, and the duration of this spark discharge is stored in a map in advance according to the engine speed and engine load. A controller for controlling the on time of the primary coil and the low voltage application time according to the required spark discharge duration, and whether the required spark discharge duration changes with time Set an interrupt mode for knowing whether the engine is operating or not, and check the engine speed during the interrupt mode and the parameters caused by engine combustion under engine load. A means for detecting a meter, a means for judging whether the parameter is proper, a minimum necessary spark discharge duration for which the parameter is proper, and a current relevant spark discharge duration stored in the map. The spark discharge duration is increased or decreased by a predetermined minute unit by increasing or decreasing the ON time of the primary coil and the low voltage application time, and the increased or decreased spark discharge duration is the engine speed corresponding to the map. An ignition control device for an engine, comprising: means for writing to an address corresponding to an engine load in place of the current spark discharge duration, and setting the spark discharge duration for learning control.