JP3443922B2 - Ignition device for two-cylinder internal combustion engine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device for a two-cylinder internal combustion engine mounted on a two-wheeled vehicle or the like, and more particularly to an improvement in the device configuration for improving the ignition characteristics at the time of starting the engine.

[0002]

2. Description of the Related Art As is well known in such an ignition device for a two-cylinder internal combustion engine, a plurality of objects to be detected (projections) are provided on the circumference of a rotating body that rotates in synchronization with the crankshaft of the engine.
By detecting this with an electromagnetic pickup sensor or the like, rotation angle information is obtained, and by extension, an ignition signal according to the rotation output of the engine is generated.

Further, in order to generate such an ignition signal, it is usually necessary to take out a specific angular position of the rotating body as a reference position at the same time as the angle information of the rotating body. And
In order to extract this reference position, (A) All but one of the plurality of objects to be detected are arranged at equal intervals, and the pulse time series output from the electromagnetic pickup sensor or the like is not at equal intervals to the other. Form a singularity. (B) The plurality of objects to be detected are arranged at equal intervals, and the width of one of them is made larger than the widths of the other objects to be detected so that the pulse time series output from the electromagnetic pickup sensor or the like is changed. , A singular point having a pulse width different from the others is formed. It is also well known that the method of etc. is used.

Incidentally, even if the rotational speed of the engine changes, normally, for example, in order to accurately detect the singular point, that is, the reference position, from the front-back relation of the pulse time series, it is usually continuous. Pulse time interval Ti of three pulses generated by
Discriminant function f1 having -2, Ti-1, and Ti as variables, that is, f1 = (Ti-1) ^ 2 / (Ti-2 * Ti), where "^" indicates exponentiation. Is calculated, and the point where the discriminant function f1 is equal to or greater than a predetermined value is set as the reference position (in the case of (A) above).・ Pulse width TWi-2 of three pulses that are generated continuously,
Discrimination function f2 having TWi-1 and TWi as variables, that is, f2 = (TWi-1) ^ 2 / (TWi-2 * TWi), where "^" indicates exponentiation. Is calculated, and the point where the discriminant function f2 is equal to or larger than a predetermined value is set as the reference position (in the case of (B) above). Etc., the reference position detection method is adopted.

By the way, in such a two-cylinder internal combustion engine, at the time of starting the compression stroke, a spontaneous ignition occurs in the compression stroke even if there is no sparking by the ignition plug for ignition, so that the so-called compression ignition causes a sudden change. It may cause an increase in rotation. When such a rapid rotation fluctuation occurs, the reference position is erroneously detected unless the sampling period and the calculation period are set to a high density by increasing the number of the detected objects. There is a risk that

Therefore, in the prior art, for example, Japanese Patent Laid-Open No. 63-309.
As described in Japanese Laid-Open Patent Publication No. 750, the relation between the discriminant function used for detecting the reference position and the arrangement of the detected object detected corresponding to the top dead center of the cylinder forming the internal combustion engine is preferable. To select. That is, a suitable ignition reference is set for each cylinder. Specifically, for example: -First to fourth objects to be detected are arranged on the rotating body at equal intervals of 90 °, and the second object to be detected out of the first to fourth objects to form the singular point more than others. In a large-sized V-type 2-cylinder 90 ° crank ignition internal combustion engine, when the discriminant function f2 is used, two of the first, second and third objects to be detected are Is made to correspond to the top dead center of the two cylinders constituting the. That is, the singular point forming pulse and the pulse immediately before it, or the singular point forming pulse and the pulse immediately after that, which have a phase difference of 90 ° from each other, are used as the ignition reference for each cylinder. This prevents erroneous detection of the reference position when a sudden rotation fluctuation occurs due to such compression ignition.

[0007]

Thus, in view of the characteristics of the discriminant function and the characteristics of the internal combustion engine itself, the arrangement of the object to be detected in which they cooperate to emphasize the electrical behavior at the singular point. By selecting the relationship, it is possible to prevent erroneous detection of the reference position.

By the way, in recent years, in order to improve the startability of the two-cylinder internal combustion engine, at the time of starting, a step advance according to the rotational speed of the engine is executed to shorten the time required for the initial explosion. Ignition timing control methods are being adopted generally.

Incidentally, the step advance angle means the front end and the rear end of the pulse output in accordance with the detection of the object to be detected from the electromagnetic pickup sensor or the like.
This is a method in which the ignition timing is set to the retard side (pulse rear end) and the ignition timing is set to the advance side (pulse front end) after the first explosion of the engine. By adopting such a step advance angle, a smooth startability of the engine can be obtained.

However, if the conventional reference position detecting method and the erroneous detection preventing method thereof are adopted for the V-type two-cylinder internal combustion engine to control the ignition timing by the step advance angle, as will be described below. Such inconvenience has become a new surface.

For example, in the V-type 2-cylinder 90 ° crank ignition internal combustion engine, as described above, in order to detect the reference position without error, a singular point forming pulse and a pulse immediately before it, or a singular point forming pulse are used. The pulse immediately after that is used as the ignition reference for each cylinder. Therefore, the ignition position including the initial explosion always reaches the singular point in any cylinder.

In order to realize the above step advance angle in such a situation, at the time of the initial explosion, it corresponds to the pulse width of another pulse that does not form a singular point from the front end of the singular point forming pulse that serves as the ignition reference. It is necessary to calculate the time to be used and delay (retard) the actual ignition timing by the calculated time.

However, when the initial explosion timing is set by such so-called arithmetic output control, the inconvenience as shown in FIG. 10 newly occurs due to the rotation fluctuation at the engine start.

That is, in FIG. 10, FIG. 10 (a) shows a cylinder cycle of a cylinder whose ignition reference is in the singular point portion, and FIG. 10 (b) shows a singular point setting method exemplified as the method of (B). FIG. 10 (c) shows the sensor output when adopted, and FIG. 10 (c) shows the waveform shaping output. When the engine is started, (1) In the compression stroke of the cylinder,
As it approaches the top dead center TDC shown in (a), its rising speed becomes weaker. (2) The manner in which the ascending speed (instantaneous rotation speed) of the piston drops depends on whether the battery is sufficiently charged or when the battery is in a state of being discharged to some extent. Differences such as those shown as characteristic lines L1 and L2 are produced. Such rotation fluctuations occur, and the ignition output controlled by the arithmetic output also changes in the manners shown in FIGS. 10E and 10F, respectively, according to the rotation fluctuations.

That is, the above calculated time is usually calculated as TSPK = (θSTEP / 90 °) × T90, where θSTEP: step advance value T90: pulse interval time. When this calculated value TSPK is output by the timer set, the angle of the timer value is
θspk = 6 × Ne × TSPK as spk, where Ne: rotational speed (rpm) TSPK: timer value (sec), and this angle θspk becomes smaller as the rotational speed Ne becomes lower. Whether the battery is fully charged or not,
As the rotation rapidly drops toward the top dead center, θSTEP '<θSTEP as shown in Fig. 10 (f) in comparison with Fig. 10 (e), and the value on the more advanced side should be taken. Become.

For this reason, when the battery is sufficiently charged, even if the timing of the initial explosion can be set to the retard side of the above-mentioned top dead center TDC, but the battery is in the discharged state. , As the discharge progresses, the same initial explosion timing moves to the advance side.

Then, as shown in FIG. 10 (f), when the discharge of such a battery progresses and the timing of this initial explosion is set to the advance side from the top dead center TDC, the piston of the cylinder concerned Before the engine has fully risen, an explosion occurs, causing the engine to reverse, making it impossible to generate effective torque. Incidentally, such a phenomenon is generally known as Ketchin.

The present invention has been made in view of the above circumstances, and it is effective not only to detect the reference position without error but also to generate such a ketching due to the execution of the step advance regardless of the state of the battery. It is an object of the present invention to provide an ignition device for a two-cylinder internal combustion engine, which can prevent the above-mentioned problems and improve its starting performance.

[0019]

In order to achieve such an object, according to the present invention, a rotating body that rotates in synchronization with a crankshaft of a two-cylinder internal combustion engine and an inter-cylinder cylinder that constitutes the engine with respect to this rotating body. A plurality of detected objects provided at an angular interval equal to the crank interval of the top dead center, sensor means for detecting passage of these detected objects and outputting angle information consisting of pulse time series, and the output angle An ignition device for a two-cylinder internal combustion engine, comprising: ignition signal generating means for generating an ignition signal to be applied to the engine ignition coil on the basis of information.
The plurality of detection objects include one singularity pulse forming body having a shape different from that of all other detection objects and forming a singularity pulse in a pulse time series output from the sensor means, The sensor means and the plurality of detected objects, when the piston of one cylinder of the engine is in the ascending process and the piston of the other cylinder is near the top dead center,
The sensor means and the singularity pulse forming body are arranged so as to face each other, and the ignition signal generating means detects a rear end of the singularity pulse from the angle information. A second reference position setting means for setting a first reference position based on the second reference function and a second reference function based on a second discriminant function for detecting the rear end of the pulse immediately after the singularity pulse from the same angle information. A second reference position setting means for setting a position, and when starting the engine, starts energization to the ignition coil based on the set first reference position as the ignition signal, and It is assumed that a signal for interrupting the energization of the ignition coil that has started is generated based on the second reference position that has been set.

[0020]

According to the above-mentioned arrangement relationship between the sensor means and the plurality of objects to be detected, the electrical behavior regarding the singular point is emphasized as in the case of the above-mentioned conventional method for preventing erroneous detection of the reference position. The detection accuracy of the first and second reference positions can be guaranteed. That is, even if the engine suddenly changes in rotation due to the compression ignition or the like as described above, it is extremely unlikely that an error will occur in the detection of those reference positions based on the discriminant function.

On the other hand, in the ignition signal generating means, when the engine is started, the ignition signal is directly sent to the ignition coil based on the first and second reference positions set corresponding to the rear ends of the two pulses. An ignition signal for starting and stopping the energization is generated.

Incidentally, in a four-cycle two-cylinder internal combustion engine, its ignition output includes normal sparks in the compression stroke and useless sparks in the exhaust stroke. But in this way the first
Further, the direct ignition output is generated corresponding to the second reference position, so that the starting time of the engine is naturally shortened under the starting condition in which the regular spark is first generated in at least one of the cylinders. Become so.

Moreover, according to the above-mentioned configuration of the ignition signal generating means, the angle at which such an initial explosion occurs is limited to the second reference position, that is, the rear end of the pulse immediately after the singular point pulse. Therefore, when the engine is started, it is possible to realize a stable step advance angle that does not require the above-described calculation output control and the like, and it is possible to obtain a stable ignition characteristic without the occurrence of ketching.

In such an arrangement as an ignition device for a two-cylinder internal combustion engine, the front end of the singularity pulse and the front end of the pulse immediately after the singularity pulse are set as the ignition reference for each cylinder of the engine, and the ignition signal is set. Further, as the generating means, (a) each time the front end of each pulse is detected from the angle information, energization to the ignition coil is started on condition that the pulse is a pulse immediately before the pulse corresponding to the ignition reference. Each time the front end of each pulse is detected from the energization starting means and (b) the same angle information, the rotation speed of the engine is higher than a predetermined speed and the pulse corresponds to the ignition reference, The energization cutoff means for cutting off the energization to the ignition coil, and (c) the front end of each pulse is detected from the same angle information with respect to the cylinder in which the front end of the singularity pulse is set as the ignition reference. Degree, the operation control means for calculating the time until power interruption and setting the timer on the condition that the rotation speed of the engine is smaller than the predetermined speed and the pulse corresponds to the ignition reference. d) If the ignition coil is energized at the set second reference position, ignition guard means for forcibly cutting off the energization may be provided. Even if the spark is generated first, the angle at which the initial explosion is caused by the subsequent regular spark is set to the second angle through the coordinated operation of the energization starting means of (a) above and the ignition guard means of (d) above. Of the reference point, that is, the trailing edge of the pulse immediately after the singularity pulse. That is, the condition for realizing a stable step advance angle is well satisfied in this case as well. In addition, under any of the above starting conditions, after the initial explosion of the engine, that is, after executing the step advance, these (a)
Through the cooperative operation of each means of (d) to (d), stable and highly accurate ignition operation can be repeated. And so on, the effect of can be played together. Here, the predetermined rotation speed of the engine referred to by the energization interruption means of (b) and the arithmetic control means of (c) means the threshold speed at which the step advance is performed.

Further, in addition to the means (a) to (d), (e) each time the rear end of each pulse is detected from the angle information, the set first and second reference values are detected. Reference position inspection means for inspecting the suitability of the position based on the first and second discriminant functions, respectively, and (f) it is judged through the reference position inspection means that either one of the first and second reference positions is not acceptable. At the same time, the ignition signal generating means may be provided with a protection means for canceling the setting of the first and second reference positions and restarting the first and second reference position setting means. According to the following, the detection accuracy of the first and second reference positions is assured by the above-described arrangement relationship between the sensor means and the plurality of detection objects. In addition to the above: -In the ignition operation after the initial explosion, the followability to the engine rotation is improved based on the inspection of the reference positions or the release / resetting of the reference positions. Like That is, no matter how the engine speed changes, an accurate ignition timing is always ensured.

The first and second reference position setting means constituting the ignition signal generating means, based on the first and second discriminant functions, for example, in the following manner, determine the target reference positions. It shall be detected and set.

That is, the first reference position setting means is: TW the pulse width of the current pulse of the pulse time series.
i, when the pulse width of the immediately preceding pulse is TWi−1, the operation F (t1) = TWi / TWi−1 is executed as the first discriminant function, and the resulting function value F (t1 ) Is a constant K
The first reference position is set on condition that it is 1 or more.
Or, the pulse width of the current pulse of the same pulse time series is TWi,
The pulse interval time between the same pulse and the preceding pulse is T
When Pi-1 is set, the same first discriminant function as
The operation F (t2) = TPi-1 / TWi is executed, and the resulting function value F (t2) is a constant K.
The first reference position is set on condition that it is 2 or less.
The second reference position setting means is: TW the pulse width of the current pulse of the pulse time series.
i, where the pulse width of the pulse immediately before that is TWi-1, and the pulse width of the pulse immediately before that is TWi-2, the calculation F (t3) = (TWi-1) as the second discriminant function. ^ 2 / (TWi-2 x TWi) However, "^" indicates exponentiation. And the resulting function value F (t3) is a constant K
The second reference position is set on condition that it is 3 or more.
I shall.

By detecting and setting the target reference position based on such a discriminant function, the influence of the engine rotation fluctuation can be minimized, and the reference position can be detected with higher accuracy. , Settings will be made.

[0029]

FIG. 1 shows an embodiment of an ignition device for a two-cylinder internal combustion engine according to the present invention.

The device of this embodiment is intended for a V-type 2-cylinder 90 ° crank ignition 4-cycle internal combustion engine for a motorcycle.
The device is configured as a device that realizes a smooth start from the initial explosion by step advancing and also maintains the ignition timing thereafter appropriately.

First, the configuration of the apparatus of this embodiment will be described with reference to FIG. In the apparatus of the embodiment, the internal combustion engine 10 is the above-mentioned V-type 2-cylinder 90 ° crank ignition 4-cycle internal combustion engine for motorcycles. In FIG. 1, for convenience, the first cylinder (# 1) 11 and the second cylinder (# 1)
2) Only the part 12 is shown.

An angle information generator 20 is provided near the crankshaft (not shown) of the internal combustion engine 10. The angle information generator 20 is used to extract the rotation angle information of the internal combustion engine 10. Has become.

That is, in the angle information generating section 20, the rotating body 21 is, for example, a disk-shaped member that rotates in synchronization with the crankshaft of the internal combustion engine 10, and a magnetic material is formed on the circumference of the rotating body 21. Four objects 1 to 4 to be detected, which are bodies, are provided. Then, the rotation passage of these detected objects 1 to 4 is detected by an electromagnetic pickup sensor (angle sensor) 22 fixedly provided in the vicinity thereof. Therefore, the sensor 22 outputs a pulse time series synchronized with the rotation angle of the internal combustion engine 10.

However, in the ignition device, as described above, it is necessary to take out a specific angular position of the rotary body 21 as a reference position at the same time as the angle information of the internal combustion engine 10, that is, the rotary body 21. Therefore, in the apparatus of this embodiment, the arrangement structure of the detected bodies 1 to 4 with respect to the rotating body 21 is the one shown in FIG.

That is, as shown in FIG. 2, the detected objects 1 to 4 are arranged at equal angular intervals of θ1 = θ2 = θ3 = θ4 = 90 ° with respect to the rotating body 21, and among them, The detected objects 1, 3 and 4 are formed at equal angles such that the projection width is, for example, θW1 = θW3 = θW4 = 10 °, and only the detected object 2 is formed as a singularity pulse forming body. However, it is formed at an angle different from that of the objects to be detected 1, 3 and 4, for example, θW2 = 50 °.

Therefore, the pulse time series output from the sensor 22 is also the interval θ between the detected objects 1 to 4.
Depending on 1 to θ4 and the projection widths θW1 to θW4, a singular point (singular point pulse) having a wider pulse width than the others occurs at a ratio of one pulse to four pulses. The pulse time series output from the angle information generator 20 in this manner is used as the angle information SiG of the internal combustion engine 10 by the control device 3
Given to 0.

The controller 30, as shown in FIG.
It comprises a waveform shaping circuit 31, a microcomputer 32, and ignition circuits 33 and 34. Here, the waveform shaping circuit 31 is a circuit that shapes the pulse time series output as the angle information SiG from the angle information generation unit 20 and converts the waveform into a binary pulse train NSiG. This pulse-shaped pulse train NSiG is input to the microcomputer 32 as an interrupt signal.

The microcomputer 32 is the ignition signal generating means of the apparatus of this embodiment, and here, based on the pulse train NSiG input as the interrupt signal,
The ignition signal is generated for the internal combustion engine 10 as described above: • A smooth start from the initial explosion due to the step advance angle; and an appropriate maintenance of the ignition timing after the initial explosion. The procedure for generating such an ignition signal by the microcomputer 32 will be described later in detail with reference to FIGS.

The ignition circuits 33 and 34 are circuits for controlling the energization / interruption of the ignition coils 40 and 50, respectively, based on the ignition signal generated by the microcomputer 32.

Incidentally, in each of the ignition coils 40 and 50, when the corresponding ignition circuit energizes and then the energization is cut off, a high voltage is generated in the secondary coil. Then, the generated high voltage drives (sparks) the corresponding sides of the spark plugs 60 and 70. The spark plugs 60 and 70 are the first and second cylinders 1 of the internal combustion engine 10 described above.
It goes without saying that they are arranged corresponding to 1 and 12.

The ignition timing of each of the cylinders 11 and 12 through the spark plugs 60 and 70 is normally adjusted according to the timing when the pistons of the cylinders reach the top dead center. Especially in the device: When the piston of one cylinder is in the ascending process and the piston of the other cylinder is near top dead center, the sensor 2
2 and the detected body 2 as the singularity pulse forming body face each other. The arrangement relationship between the sensors 22 and the detected objects 1 to 4, that is, the ignition reference is set so as to have the above relationship.

Now, FIG. 3 shows the processing principle of the above-mentioned step advance angle. Prior to the explanation of the ignition signal generation procedure as the apparatus of the embodiment through the microcomputer 32, first, A brief description of this step advance angle will be added.

As shown in FIG. 3, the step advance angle is as follows: The front and rear ends of the pulse output from the sensor 22 in accordance with the detection of the detection objects 1 to 4, that is, the binarization. By using the fall and rise of the waveform shaping signal NSiG, when the internal combustion engine 10 is started, its ignition timing is retarded (signal N
After the first explosion of the engine 10, the ignition timing is set to the advance side (fall of the signal NSiG). It is a starting method such as. As described above, by adopting such a step advance angle, a smooth start of the engine 10 can be obtained.

In FIG. 3, the arrow added as P1 indicates the top dead center position when the internal combustion engine 10 is started.
If the initial explosion occurs at the rising timing of the signal NSiG that is on the retard side of the position P1, there is no concern that the above-mentioned ketchin or the like will occur.

Further, in FIG. 3, "Nstp" is
The threshold rotation speed of the internal combustion engine 10 for executing the step advance is shown, “idling” shows the idling rotation speed of the engine 10, and “θSTEP” shows the advance value at the step advance. . Further, the graph itself in FIG. 3 shows the required ignition timing characteristic.

In the apparatus of this embodiment, the internal combustion engine 10 is processed through the procedure described below by the microcomputer 32 so as to realize such step advancement without using arithmetic output control or the like under any circumstances. Generates an ignition signal of.

First, the processing executed by the microcomputer 32 for detecting and setting the reference position based on the above-mentioned singular point will be described with reference to FIG. In FIG. 4, FIG. 4A shows angle information (pulse time series) SiG output from the angle information generator 20 (sensor 22).
4B shows the waveform shaping signal NSiG output from the waveform shaping circuit 31 corresponding to the angle information SiG.
Indicates. The microcomputer 32 is interrupted by the falling edge and the rising edge of the waveform shaping signal NSiG, and the pulse width TW and the pulse interval time TP of the signal NSiG are shown in FIG.
And (d).

In FIG. 4, FIG. 4 (e) shows the sampling number i of the signal NSiG by the microcomputer 32, and FIG. 4 (f) shows a singular point pulse (width θ).
The angular position information Npos of the first cylinder 11 is shown with the pulse immediately after (W2 pulse) as the ignition reference. In the microcomputer 32, the angular position information Npos corresponding to the ignition reference is set to "0", and the angular position of each cylinder at each time is grasped.

When the pulse width TW is measured as the time from the falling edge to the rising edge of the waveform shaping signal NSiG, the existence of the singular point pulse causes
The content of the measurement is in the form shown in FIG.

Therefore, the microcomputer 32 measures the current pulse so that the existence of such a singularity pulse, more accurately, the rising edge of the singularity pulse can be recognized even if the internal combustion engine 10 changes in rotation. The calculation F (t1) = TWi / TWi-1 (1) is executed, where TWi is the pulse width and TWi-1 is the pulse width measured for the immediately preceding pulse, and the resulting function value F (t1 ) Is a constant K
The rising edge of the singularity pulse is recognized on condition that it is 1 or more. Hereinafter, the rising edge of the singularity pulse recognized in this way is referred to as a first reference position. The relationship between the discriminant function F (t1) and the constant K1 is shown in FIG.

For the first reference position which is the rising edge of the singularity pulse, the pulse width measured for the current pulse is also measured based on TWi, the pulse and the pulse immediately before it. The pulse interval time
As i-1, the operation F (t2) = TPi-1 / TWi (2) is executed, and the resulting function value F (t2) is a constant K.
It can be recognized on the condition that it is 2 or less. In the interrupt processing described later in detail with reference to FIG.
The discriminant function F (t2) and the constant K2 are used to set the first reference position. The relationship between the discriminant function F (t2) and the constant K2 is shown in FIG. 4 (i).

On the other hand, in the microcomputer 32, the rising edge of the pulse immediately after the singularity pulse is separately added in order to improve the determination accuracy of the reference position and stably realize the step advance angle described above. recognize.

That is, in the microcomputer 32, the pulse width measured for the current pulse is TWi,
The pulse width measured for the immediately preceding pulse is TWi
-1, the pulse width measured for the two previous pulses is TWi
As -2, calculation F (t3) = (TWi-1) ^ 2 / (TWi-2 * TWi) (3) where "^" indicates exponentiation. And the resulting function value F (t3) is a constant K
On the condition that the number is 3 or more, the rising edge of the pulse immediately after the singularity pulse is recognized. Hereinafter, the rising edge of the pulse immediately after the singularity pulse thus recognized is referred to as a second reference position. The relationship between the discriminant function F (t3) and the constant K3 is shown in FIG. 4 (j).

5 and 6 show the processing procedure of the angle sensor interrupt processing of the microcomputer 32 and the ignition output control processing which are executed based on the recognition of the reference position or the grasp of the angular position Npos. The procedure for generating the ignition signal by the microcomputer 32 will be described in detail below with reference to FIGS. 5 and 6 together.

When the internal combustion engine 10 is started by a starter or the like not shown in FIG. 1, the angle information generator 20 (sensor 22) outputs the angle information SiG as shown in FIG. 4 (a). In addition, the waveform shaping circuit 31 outputs the waveform shaping signal N as shown in FIG.
SiG is output. Then, in this way, the waveform shaping signal N
The output of SiG causes the microcomputer 32 to make an interrupt (interruption of the angle sensor) by its falling edge and rising edge, and each time, the interrupt process based on the procedure shown in FIG. 5 is repeatedly executed.

That is, if this interrupt occurs now, the microcomputer 32 proceeds to step 100.
As a result, the interrupt generation time is latched and the value (timer value) is stored in the internal memory.

Then, in step 101, the microcomputer 32 determines whether the interrupt is caused by a rising edge or a falling edge. If the interrupt is due to the rising edge, the pulse width TWi is measured in step 200, and if it is due to the falling edge, step 300.
Then, the pulse interval time TPi is measured.

If the interrupt is due to a rising edge, the microcomputer 32 then proceeds to step 2
As 10, it is determined whether or not the flag FLAG1 indicating that the first reference position has been set is set. Initially, this flag FLAG1 is cleared.

Therefore, in this case, the microcomputer 32 executes (1) the calculation of the above equation (2) based on the pulse width TWi and the pulse interval time TPi-1 obtained at that time, and The value of the discriminant function F (t2) is obtained (step 211). (2) The value of the discriminant function F (t2) thus obtained is the above constant K.
On condition that the number is 2 or less (step 212), the ignition circuit (ignition circuit 33) corresponding to the first cylinder (# 1) 11 is driven, and the corresponding ignition coil (ignition coil 40).
Energization is started (step 213). In addition, this first
Regarding the ignition signal for the cylinder (# 1) 11,
Notated as G1. (3) The flag FLAG1 is set, and the detection and setting of the first reference position is completed (step 214). A series of processing such as is executed.

The processing procedure in steps 211 to 214 is the first in the apparatus of this embodiment.
Of the reference position setting means. Also, in step 21 above.
If it is determined in step 2 that the value of the determined discriminant function F (t2) is not equal to or less than the constant K2, it is determined that the pulse related to the interrupt does not correspond to the first reference position, and the interrupt is interrupted. Exit the process once.

On the other hand, if the interrupt is due to a rising edge and the flag FLAG1 has already been set, or if the setting of the flag FLAG1 is finished in step 214, the microcomputer 32 Further, as step 220, it is determined whether or not the flag FLAG2 indicating that the second reference position has been set is set.
This flag FLAG2 is also initially cleared.

Therefore, in this case, the microcomputer 32 (1) based on the three consecutive pulse widths TWi, TWi-1, and TWi-2 obtained at that time, the above (3)
The value of the discriminant function F (t3) is obtained by executing the equation calculation (step 221). (2) The value of the discriminant function F (t3) thus obtained is the above constant K.
On condition that the number is 3 or more (step 222), the ignition circuit corresponding to the first cylinder (# 1) 11 (ignition circuit 3
The driving of 3) is stopped, and the energization of the corresponding ignition coil (ignition coil 40) is cut off (step 223).
As described above, the interruption of the energization causes a high voltage to be generated in the secondary coil of the secondary coil to drive (spark) the corresponding spark plug (spark 60). That is, the interruption of the power supply causes a spark in the corresponding cylinder. (3) The flag FLAG2 is set, and the detection and setting of the second reference position is completed (step 224). A series of processing such as is executed.

The processing procedure in steps 221 to 224 is the same as the second one in the apparatus of this embodiment.
Of the reference position setting means. Also, the above step 2
Also in 22, when it is determined that the value of the determined discriminant function F (t3) is not the constant K3 or more, it is determined that the pulse related to the interrupt does not correspond to the second reference position, and Exit interrupt processing once.

Even when the setting of the flag FLAG2 is completed in step 224, the interrupt processing is once completed. On the other hand, when the interrupt is due to a rising edge and both the flags FLAG1 and FLAG2 have already been set, that is, the first spark is generated in accordance with the setting of the first and second reference positions. After the generation, the microcomputer 32
In step 230, confirmation processing is performed on the set reference position.

In the reference position confirmation processing, the microcomputer 32 determines the discriminant functions F (t2) and F (t2).
Based on (t3) and the corresponding constants K2 and K3, it is confirmed whether or not the settings for the first and second reference positions are correct.

Then, as a result of this reference position confirmation (step 231), if it is determined to be abnormal, the flag F is set.
Abnormality processing such as clearing both LAG1 and FLAG2 is executed, and the interrupt processing is temporarily ended (step 232). In this case, the first reference position setting process (steps 211 to 214) and the second reference position setting process (steps 221 to 224) described above are repeated again based on the rising edge interrupt from the next time. It will be.

As a result of the reference position confirmation (step 231), if it is determined to be normal, the rise of the pulse (pulse of angular position information Npos = 0) set as the ignition reference of each cylinder is interrupted. On the condition that it is an edge, if it is currently energized, a so-called ignition card process for immediately turning off the energization is executed (step 233).

Incidentally, the above steps 230 to 23
The processing procedure according to No. 1 constitutes the reference position inspection means in the apparatus of this embodiment, the processing procedure according to the above step 232 constitutes the protection means in the apparatus of the same embodiment, and the processing procedure according to the above step 233 is The ignition guard means is configured in the apparatus of the embodiment.

Next, in the interrupt (angle sensor interrupt) process, the process of the microcomputer 32 when the interrupt is caused by the falling edge will be described.

If the interrupt is due to the falling edge, the microcomputer 32 executes the above step 3
After measuring the pulse interval time TPi as 00, it is determined at step 310 whether or not the flag FLAG2 is set.

Then, while the flag FLAG2 is cleared, the interrupt process is left as it is. If the flag FLAG2 is set, then the microcomputer 32 executes the ignition output control process in step 320. Run. Details of this ignition output control process are shown in FIG.

That is, in the ignition output control process,
The microcomputer 32 first updates the contents of the recognized angular position information Npos (step 320).
1) Then, the current operation mode of the internal combustion engine 10 is determined (step 3202). In this operation mode determination, a rotation speed slightly higher than the idling rotation speed shown in FIG. 3 is set as a threshold value, and if the rotation speed of the engine 10 at that time is lower than this threshold rotation speed, the “waveform synchronization mode” is set.
If it is higher than the threshold rotational speed, it is determined that the “arithmetic control mode” is set.

In the microcomputer 32 which has thus judged the mode, the judged mode is the "arithmetic control mode".
If so (step 3203), a well-known arithmetic control process for the same ignition timing is executed so that the required ignition timing characteristics shown in the region of the idling speed or more in FIG. 3 are satisfied (step 3220). .

On the other hand, if the determined mode is the "waveform synchronization mode" (step 3203), the microcomputer 32 executes the above step advance angle.
Perform the processes listed below. (1) Based on the measured pulse interval time TPi,
The engine speed at that time of the engine 10 is determined (step 3210). (2) If the determined rotation speed is smaller than the threshold rotation speed Nstp for the step advance angle (step 3211),
On condition that the updated angular position information Npos is "3" (step 3214), energization to the corresponding ignition coil is started (step 3215). Even if the determined rotational speed is smaller than the threshold rotational speed Nstp, if the updated angular position information Npos is not "3", the ignition output control process is ended. (3) If the determined rotation speed is larger than the threshold rotation speed Nstp of the step advance angle (step 3211),
On condition that the updated angular position information Npos is "0" (step 3212), the energization to the corresponding ignition coil is cut off (step 3213). (4) When the determined rotation speed is larger than the threshold rotation speed Nstp of the step advance angle (step 321)
1) If the updated angular position information Npos is "3" (step 3214), energization of the corresponding ignition coil is started (step 3215). Also in this case, if the updated angular position information Npos is not "3", the ignition output control process is terminated.

In the "waveform synchronization mode", the processes (1) to (4) are repeatedly executed each time an interrupt is generated by the falling edge of the waveform shaping signal NSiG.

However, the cylinder for which the ignition reference (angular position information Npos = 0) is set at the trailing edge of the singularity pulse,
That is, the second cylinder (# 2) 1 in the apparatus of this embodiment
Regarding No. 2, when it is determined in step 3211 that the rotation speed of the internal combustion engine 10 is smaller than the threshold rotation speed Nstp of the step advance angle, (5) the updated angular position information Npos is “0”. Under the condition (step 3231), the time TSPK until the above-mentioned power interruption is calculated (step 323).
2) Set this in an internal timer (step 32)
33). The arithmetic control process 3 shown by the broken line in FIG.
230 is executed through the microcomputer 32.

Here, the processing procedure relating to the arithmetic control processing 3230 (steps 3231 to 3233) constitutes the arithmetic control means in the apparatus of this embodiment. Similarly, the above steps 3214 to 32
The processing procedure according to 15 constitutes the energization starting means in the apparatus of the embodiment, and the processing procedure according to the above steps 3212 to 3213 constitutes the energization cutoff means in the apparatus of the embodiment.

By repeatedly executing the angle sensor interrupt process shown in FIG. 5 and the ignition output control process shown in FIG. 6 through the apparatus of this embodiment, when the internal combustion engine 10 is started, as shown in FIG. In the manner shown, the ignition signals IG1 and IG2 will be generated.

Next, with reference also to FIG. 7, an ignition operation mode at the time of engine starting by the apparatus of the embodiment will be described. In FIG. 7, FIG. 7A shows the first cylinder (#
1) 11 shows each cylinder cycle of the second cylinder (# 2) 12 and FIG. 7B shows the waveform shaping signal NSiG.
Further, FIG. 7C shows the angular position information Np of each cylinder.
indicates os.

Further, "B # 1" additionally described in correspondence with FIGS. 7 (a) to 7 (c) indicates the ignition reference of the first cylinder 11,
“B # 2” indicates the ignition reference of the second cylinder 12, respectively.
As described above, the ignition reference for the first cylinder 11 is set to the trailing edge (front end) of the pulse immediately after the singularity pulse, and the ignition reference for the second cylinder is set to the trailing edge (front end) of the singularity pulse. Is.

Now, the internal combustion engine 10 is shown in FIG.
As shown in FIG. 5, if it is assumed that the first cylinder 11 is started at time t10, which is before the start of the compression stroke, the first reference position is detected at time t11 through the angle sensor interrupt process of FIG. When the ignition coil 40 is set and energized, the second reference position is detected and set at time t12 thereafter, and the energization of the ignition coil 40 is cut off. This state is shown as a change in the ignition signal IG1 in FIG.

Then, by interrupting the power supply to the ignition coil 40 in this way, the first ignition is performed through the ignition plug 60.
A spark (regular spark) is generated in the cylinder, and at the same time t12, an initial explosion occurs in the engine 10. The timing of this initial explosion is shown by the mark "○" in FIG. 7 (d). Further, this initial explosion occurs at the rising (rear end) portion of the pulse immediately after the singularity pulse, as shown in FIG. 7 (b). That is, referring to FIG. 3 described above, it occurs on the retard side with respect to the top dead center position P1.

On the other hand, since the first explosion occurs in this way,
The rotation speed (speed) Ne of the internal combustion engine 10 begins to rise in the manner shown in FIG. Then, after the same rotation speed Ne exceeds the threshold rotation speed Nstp, the above-described FIG.
Through the ignition output control process of FIG. 7, for the first cylinder, for example, as shown at time t15 or time t18 in FIGS. Sparks will be generated in the part. That is, it can be seen that the step advance angle is realized in the mode shown in FIG. The spark generated at the time t15 is a spark generated in the exhaust stroke of the first cylinder and is a so-called useless spark.

Corresponding to such an ignition operation in the first cylinder 11, the ignition operation (generation operation of the ignition signal IG2) is performed in the second cylinder 12 in the manner shown in FIG. 7 (g). Be seen.

Incidentally, in the second cylinder 12, as shown in FIG.
Through the ignition output control process of the
At time t13 or time t16 when s becomes “3”, energization of the ignition coil 50 is started, and the same angular position information Npos is obtained.
At time t14 or time t17 when is 0, the power supply to the ignition coil 50 is cut off.

On the other hand, the internal combustion engine 10 is shown in FIG.
As shown in, the engine may be started from time t20, which is before the start of the compression stroke of the second cylinder 12. In this case, through the angle sensor interrupt process of FIG. 5, at time t21,
The first reference position is detected and set, and the energization of the ignition coil 40 is started. At a subsequent time t22, the second reference position is detected and set, and the energization of the ignition coil 40 is cut off. . This state is shown in FIG.
Shown as a change of 1.

However, in this case, the sparks generated through the ignition signal IG1 become useless sparks, and the actual initial explosion of the engine 10 will occur at the subsequent time t26. Further, in this case, the interruption of power supply at the initial explosion time t26 is performed through the ignition guard process (step 233 in FIG. 5).

As shown in FIG. 7 (b), the initial explosion is again caused by the rising (rear end) portion of the pulse immediately after the singularity pulse, that is, at the top dead center in FIG. It occurs on the retard side from the position P1.

FIG. 7 (i) shows the transition of the rotation speed (speed) Ne of the internal combustion engine 10 in such a case. Further, in this case, in response to such an ignition operation in the first cylinder 11, the ignition operation is performed in the second cylinder 12 in the mode shown in FIG. 7 (k).

That is, in this case, in the second cylinder 12, energization is started at time t23 when the angular position information Npos becomes "3" through the ignition output control process of FIG. Is the same angular position information N
From time t24 when pos becomes "0", the above calculation time TSP
It is executed at time t25 when only K21 has elapsed. Such arithmetic output control is performed by the arithmetic control processing 3230 indicated by the broken line in FIG.
(Steps 3231 to 3233). However, in the case of the device of this embodiment, such arithmetic output control is not performed at the first explosion.

For reference, FIGS. 8 and 9 show the ignition operation by the conventional apparatus as described in, for example, Japanese Unexamined Patent Publication (Kokai) No. 63-309750, and the ignition operation by the apparatus of the embodiment. It is shown in comparison.

Incidentally, even in the above-mentioned conventional apparatus, the output of the waveform shaping signal NSiG causes an interrupt (angle sensor interrupt) due to its falling edge and rising edge. It is assumed that the interrupt processing based on the procedure as shown is repeatedly executed.

However, in the conventional apparatus, the first
The processing of steps 210 to 214 regarding the detection, setting and energization processing of the reference position of No., and the interruption processing of step 223 are not performed. That is, at the time of interruption by the rising edge of the signal NSiG, for example, only the setting of the reference position based on the discriminant function F (t3) and its check processing are performed.

On the other hand, the ignition output control process upon interruption at the falling edge of the signal NSiG (step 32)
In 0), the processing as shown in FIG. 6 is similarly executed.

In the example of FIG. 8, the ignition reference B # 1 of the first cylinder is set to the trailing edge (front end) of the pulse immediately after the singularity pulse, and the ignition of the second cylinder is set similarly to the apparatus of the above-described embodiment. The reference B # 2 is set to the trailing edge (front end) of the singularity pulse, and in this case, as shown in FIG. 8D, the engine starts from time t30, which is before the start of the compression stroke of the first cylinder. Assuming that the engine is started: First, at time t31, the reference position is detected and set based on the discriminant function F (t3). -Time t32 based on the ignition output control process shown in FIG.
Then, the second cylinder (more precisely, its corresponding ignition coil) is energized (see FIG. 8 (g)). Next, at the time t33, the ignition reference of the second cylinder is reached, but at this time the engine speed (speed) Ne has not reached the threshold value Nstp of the step advance angle, so the ignition output also shown in FIG. Time through control processing TSPK31
Is calculated, and the same calculation time TSPK31 is set by a timer (see FIGS. 8 (e) and 8 (g)). -At time t34 when the timer time elapses, the second cylinder is de-energized, and the initial explosion occurs at time t34 (see FIGS. 8 (g) and 8 (d)). In this manner, the ignition operation is executed. It should be noted that, except that the inspection of the reference position is performed by only one discriminant function described above, the ignition operation after the first explosion (from time t35) is based on the apparatus of the above embodiment.

On the other hand, in the example of FIG. 8, as shown in FIG. 8 (h), if it is assumed that the engine is started from time t40, which is before the start of the compression stroke of the second cylinder: First, at time t41, The reference position is detected and set based on the discriminant function F (t3). -From time t42 to time t44, a spark is generated in the second cylinder in a manner similar to the behavior in the second cylinder at the time t32 to time t34, but this is a spark in the exhaust stroke and a useless spark. (See FIG. 8 (k)). -Next, at time t45, a spark is generated in the first cylinder based on the above-mentioned ignition guard process, and this will lead to the initial explosion of the engine (see FIG. 8 (j)). With such a mode,
The ignition operation is executed.

Thus, according to the example of FIG. 8, the engine is the second
When starting from time t40, which is before the start of the compression stroke of the cylinder, the initial explosion occurs in synchronization with the waveform of the waveform shaping signal NSiG, but at time t before the start of the compression stroke of the first cylinder.
If it is started from 30, the arithmetic power control will cause the initial explosion.

In the example of FIG. 9, the ignition reference B # 1 for the first cylinder is set to the trailing edge (front end) of the singularity pulse, and the ignition reference B # 2 for the second cylinder is set differently, unlike the above. It is set to the trailing edge (front end) of the pulse immediately before the point pulse. In this case, as shown in FIG. 9 (d), if the engine is started at time t50, which is before the start of the compression stroke of the first cylinder, first, at time t51, the discriminant function F (t3) is set. The reference position is detected and set based on. -Time t52 based on the ignition output control process shown in FIG.
Then, energization of the second cylinder (to be exact, to its corresponding ignition coil) is started (see FIG. 9 (g)). Next, at time t53, the ignition reference of the second cylinder is reached, but at this time the engine speed (speed) Ne has not reached the threshold value Nstp of the step advance angle, so the ignition output control process is temporarily exited ( 9 (e) and (g)). -And the next time t synchronized with the rising edge of the pulse
At 54, the second guard cylinder is de-energized through the ignition guard process, and the first explosion occurs at the same time t54 (Fig. 9).
(See (g) and (d)). In this manner, the ignition operation is executed. Also in this case, the ignition operation (from time t55) after the initial explosion is basically in accordance with the apparatus of the above embodiment except that the reference position is inspected by only one discriminant function.

On the other hand, in the example of FIG. 9, as shown in FIG. 9 (h), if it is assumed that the engine is started from time t60, which is before the start of the compression stroke of the second cylinder: First, at time t61, The reference position is detected and set based on the discriminant function F (t3). -From time t62 to time t64, a spark is generated in the second cylinder in a manner similar to the behavior of the second cylinder at the time t52 to time t54, but this is a spark in the exhaust stroke and a useless spark. (See FIG. 9 (k)). During this time, at time t63, the first cylinder is energized based on the ignition output control process shown in FIG. 6 (see FIG. 9).
(See (j)). Next, at time t65, the ignition reference of the first cylinder is reached, but at this time, the engine speed (speed) Ne has not reached the threshold value Nstp of the step advance angle, so the ignition output also shown in FIG. Through control processing time TSPK61
Is calculated, and the same calculation time TSPK61 is set by a timer (see FIGS. 8 (i) and 8 (j)). -At time t66 when the timer time elapses, the power supply to the first cylinder is cut off, and the initial explosion occurs at the time t66 (see FIGS. 9 (k) and 9 (h)). In this manner, the ignition operation is executed.

Thus, according to the example of FIG. 9, the engine is the first
When starting at time t50, which is before the start of the compression stroke of the cylinder, the initial explosion occurs in synchronization with the waveform of the waveform shaping signal NSiG, but at time t before the start of the compression stroke of the second cylinder.
When starting from 60, the initial explosion will occur due to the arithmetic output control.

As is apparent from the comparison with the ignition operation by the conventional device, according to the device of this embodiment, (a) the engine is started before the compression stroke of the first cylinder (# 1) 11 is started. In the case (see FIGS. 7D to 7G), the ignition output (IG1) immediately after the position detection by the discriminant functions F (t2) and F (t3) becomes a regular spark, and the startability until the first explosion is reached. Is greatly improved to a crank angle of 180 + α degrees. Incidentally, in the conventional device illustrated in FIGS. 8 and 9, the startability from the start to the initial explosion is 4 crank angle.
50 + α degrees, which is never good. Further, even when it is started in a short period of time in this way, the initial explosion position is a position where the waveform advance signal NSiG falls and rises, that is, the step advance angle using the front and rear end pulses of the sensor output can be implemented (singular). It is the trailing edge of the pulse immediately after the point pulse). (B) On the other hand, when the engine is started before the compression stroke of the second cylinder (# 2) 12 is started (see FIGS. 7 (h) to 7 (k)), the discriminant functions F (t2) and F (t3) are obtained. The ignition output (IG1) immediately after the position detection by () becomes a useless spark. For this reason,
Crank angle of 6
The degree is 30 + α degrees, which is almost the same as that of the conventional apparatus. However, even in this case, the initial explosion position is a position where the step advance angle using the front and rear end pulses of the sensor output can be realized (in this case also, the rear end of the pulse immediately after the singularity pulse). (C) Further, two different discriminant functions are used to detect and set the reference position, and the ignition output control is executed only when the conditions based on these discriminant functions are both satisfied. There is no possibility of erroneous ignition control due to fluctuations in rotation at the time of start-up or rapid rotation increase due to compression ignition. Of course, even after the first explosion, accurate ignition timing is always secured, and many excellent effects can be obtained.

For this reason, stable ignition characteristics can be obtained without causing the above-mentioned ketchin or the like. In the apparatus of this embodiment, in order to detect and set the first reference position, the discriminant function F shown in the above equation (2) is used.
Although (t2) was used, as shown in FIG.
The first reference position can be similarly detected and set by using the discriminant function F (t1) shown in the equation.

Even in this case, substantially the same effect as described above can be obtained. However, as a discriminant function for detecting and setting the first reference position, it is only necessary to be able to detect the rear end of the singular point pulse from the waveform shaping signal NSiG (angle information), and these discriminant functions are not always required. Any function that is not limited to the functions F (t1) and F (t2) can be adopted.

Similarly, as the discriminant function for detecting and setting the second reference position, the waveform shaping signal NSiG is also used.
It suffices that the trailing edge of the pulse immediately after the singularity pulse can be detected from (angle information).
Any function that is not limited to (t3) can be adopted.

Further, in the apparatus of the embodiment, the ignition signal generating means (microcomputer 32) is the first
In addition to the first and second reference position setting means for setting the second and second reference positions, respectively, (a) energization starting means for starting energization of the ignition coil, and (b) energization interruption for interrupting energization of the ignition coil. Means (c) Computation of time until energization cutoff and timer setting for this arithmetic control means (d) Ignition guard means for forced interruption of energization (e) Checking suitability of the set first and second reference positions Reference position inspecting means (f) is provided with all the protection means for canceling the setting when the reference positions are judged to be no. However, the ignition signal generating means includes at least the first and second reference position setting means, and when the engine is started, as an ignition signal thereof, the ignition coil is based on the set first reference position. It suffices as long as it is possible to start the energization of the ignition coil and generate a signal that interrupts the energization of the ignition coil that has started based on the second reference position set above.

As described above, the direct ignition output is generated corresponding to the first and second reference positions, so that at least one of the cylinders has a starting condition in which a normal spark occurs first. The time required will naturally be shortened.

Moreover, with this configuration of the ignition signal generating means, the angle at which the initial explosion occurs is limited to the second reference position, that is, the trailing end of the pulse immediately after the singularity pulse. Therefore, when the engine is started, it is possible to realize a stable step advance angle that does not require the above-described calculation output control and the like, and it is possible to obtain a stable ignition characteristic without the occurrence of ketching.

Further, by additionally using the means of (a) to (d), even if a waste spark is generated first due to the starting condition of the engine, the angle at which the initial explosion is caused by the subsequent regular spark. Can be limited to the trailing edge of the pulse immediately after the singularity pulse. That is, the condition for realizing a stable step advance angle is well satisfied in this case as well.

Therefore, as the ignition device according to the present invention, in addition to the first and second reference position setting means,
A configuration may be provided in which only these means (a) to (d) are combined.

Further, like the apparatus of the above-mentioned embodiment, by further including the reference position inspection means (e) and the protection means (f), an accurate ignition timing is always ensured even after the initial explosion. This is as described above.

In the above-mentioned embodiment, for the sake of convenience, the case where the ignition device according to the present invention is applied to the V-type two-cylinder 90 ° crank ignition internal combustion engine has been described. , V type 2 cylinder 60 ° crank ignition internal combustion engine and the like can be similarly applied.

The point is that, with respect to the rotating body that rotates in synchronization with the crankshaft of the internal combustion engine, at an angular interval equal to the top dead center crank interval between the cylinders forming the same engine (for example, a V-type 2-cylinder 6 cylinder).
(In the case of a 0 ° crank ignition internal combustion engine, at 60 ° intervals),
The plurality of detection objects may be provided.

However, even in this case, one of the plurality of objects to be detected constitutes a singularity pulse former. The sensor means (sensor 22) and the plurality of objects to be detected are the sensor means and the sensor means when the piston of one cylinder of the engine is in the ascending process and the piston of the other cylinder is near the top dead center. The singularity pulse forming body should be arranged in a position so as to face it. The conditions do not change. Under such conditions,
If the above-mentioned configuration is adopted as the ignition signal generating means, it is possible to obtain the same effect as the above for any two-cylinder internal combustion engine.

[0114]

As described above, according to the present invention, two reference positions for the rotation angle of the two-cylinder internal combustion engine, that is, the rear end of the singular point pulse and the same singular point are based on the two kinds of discriminant functions. The trailing edge of the pulse immediately after the point pulse can be detected without error.

According to the invention, when the engine is started,
Since the start and stop of energization of the ignition coil are directly performed based on these two reference positions, the time required for the initial explosion of the engine is naturally shortened.

Further, according to the present invention, the angle at which such an initial explosion occurs is limited to the trailing end of the pulse immediately after the singularity pulse. Therefore, when the engine is started, it is possible to realize a stable step advance angle that does not require calculation output control and the like, and eventually it is possible to obtain stable ignition characteristics without the occurrence of ketching or the like.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of an ignition device for a two-cylinder internal combustion engine according to the present invention.

FIG. 2 is a front view showing a specific configuration of a rotating body and a detected body forming the angle information generating section of the apparatus of the embodiment.

FIG. 3 is a diagram showing a processing principle of a step advance angle.

FIG. 4 is a timing chart showing pulse time series extracted by the apparatus of the embodiment and a function waveform of a discriminant function used by the apparatus of the embodiment to detect a reference position of an engine rotation angle.

FIG. 5 is a flowchart showing a processing procedure of angle sensor interrupt processing by the apparatus of the embodiment.

FIG. 6 is a flowchart showing a processing procedure of ignition output control processing by the apparatus of the embodiment.

FIG. 7 is a timing chart showing an ignition operation mode when the engine is started by the apparatus of the embodiment.

FIG. 8 is a timing chart showing an ignition operation mode when the engine is started by the conventional ignition device, in comparison with FIG. 7.

9 is a timing chart showing an ignition operation mode at the time of starting the engine by the conventional ignition device, in comparison with FIG. 7.

FIG. 10 is a timing chart showing that a problem occurs due to a rotational fluctuation of the engine when a step advance is performed by calculation output control.

[Explanation of symbols]

1, 3, 4 ... Object to be detected, 2 ... Object to be detected as singular point pulse former, 10 ... V-type 2-cylinder internal combustion engine, 11 ... First cylinder, 12 ... Second cylinder, 20 ... Angle information generator , 21 ... Rotating body, 22 ... Electromagnetic pickup sensor as an angle sensor, 30 ... Control device, 31 ... Waveform shaping circuit, 32 ... Microcomputer, 33, 34 ... Ignition circuit, 40, 50
... ignition coil, 60, 70 ... spark plug.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F02P 3/04 F02D 45/00 F02P 7/067

Claims (5)

(57) [Claims] 1. A rotating body that rotates in synchronism with a crankshaft of a two-cylinder internal combustion engine, and a plurality of rotating bodies provided at an angular interval equal to the top dead center crank interval between the cylinders forming the engine. Detection objects, sensor means for detecting passage of these detection objects and outputting angle information in pulse time series, and an ignition signal applied to the engine ignition coil based on the output angle information. In the ignition device for a two-cylinder internal combustion engine, the pulse time series output from the sensor means has a shape different from that of all other detected bodies. One of the singularity pulse forming bodies that forms a singularity pulse is included in the sensor means and the plurality of detection objects, and the piston of one cylinder of the engine is in the ascending process and the piston of the other cylinder Is above When located near the point, the sensor means and the singularity pulse forming body are arranged so as to face each other, and the ignition signal generating means detects the rear end of the singularity pulse from the angle information. To set a first reference position based on the discriminant function of
And a second reference position setting means for setting a second reference position based on a second discriminant function for detecting the trailing end of the pulse immediately after the singularity pulse from the same angle information. When the engine is started, energization to the ignition coil is started based on the set first reference position as the ignition signal, and based on the set second reference position. An ignition device for a two-cylinder internal combustion engine, which generates a signal for interrupting the energization of the started ignition coil. 2. The ignition system for a two-cylinder internal combustion engine according to claim 1, wherein a front end of the singularity pulse and a front end of a pulse immediately after the singularity pulse are defined as ignition references for the cylinders of the engine, respectively. The ignition signal generating means, each time the front end of each pulse is detected from the angle information, energization starting means for starting energization to the ignition coil on condition that it is a pulse immediately before the pulse corresponding to the ignition reference. And each time the front end of each pulse is detected from the same angle information, the ignition coil is energized on condition that the rotation speed of the internal combustion engine is higher than a predetermined speed and the pulse corresponds to the ignition reference. With respect to the cylinder for which the leading end of the singularity pulse is set as the ignition reference, the leading end of each pulse is detected from the same angle information,
Calculation control means for calculating the time until power interruption and setting a timer for this, provided that the rotation speed of the internal combustion engine is lower than the predetermined speed and is a pulse corresponding to the ignition reference, An ignition device for a two-cylinder internal combustion engine, further comprising: an ignition guard means for forcibly interrupting the energization of the ignition coil when the ignition coil is energized at the second reference position. 3. The ignition device for a two-cylinder internal combustion engine according to claim 1 or 2, wherein the ignition signal generating means sets the first and the set values each time a trailing end of each pulse is detected from the angle information. Reference position inspection means for inspecting the adequacy of the second reference position based on the first and second discriminant functions, respectively, and whether or not either one of the first and second reference positions is passed through the reference position inspection means. When the determination is made, it further comprises a protection means for canceling the setting for the first and second reference positions and restarting the first and second reference position setting means. Ignition device for cylinder internal combustion engine. 4. The first reference position setting means sets a pulse width of a current pulse of a pulse time series which is the angle information to T.
Wi, where Twi-1 is the pulse width of the immediately preceding pulse, the operation F (t1) = TWi / TWi-1 is executed as the first discriminant function, and the resulting function value F ( t1) is a constant K
The first reference position is set on condition that it is 1 or more, and the second reference position setting means sets the pulse width of the current pulse of the same pulse time series to TWi, which is one pulse before it. The pulse width of the pulse is TWi-1, the pulse width of the immediately preceding pulse is TWi-1,
When it is set to -2, as the second discriminant function, the calculation f (t3) = (TWi-1) ^ 2 / (TWi-2 * TWi), where "^" indicates exponentiation. And the resulting function value F (t3) is a constant K
The ignition device for a two-cylinder internal combustion engine according to claim 1, 2 or 3, wherein the second reference position is set on condition that the number is 3 or more. 5. The first reference position setting means sets a pulse width of a current pulse in a pulse time series which is the angle information to T.
Wi, when the pulse interval time between the same pulse and the pulse immediately before it is TPi−1, as the first discriminant function,
The operation F (t2) = TPi-1 / TWi is executed, and the resulting function value F (t2) is a constant K.
The first reference position is set on condition that the pulse width is 2 or less, and the second reference position setting means sets the pulse width of the current pulse of the same pulse time series to TWi, which is one pulse before it. The pulse width of the pulse is TWi-1, the pulse width of the immediately preceding pulse is TWi-1,
When it is set to -2, as the second discriminant function, the calculation f (t3) = (TWi-1) ^ 2 / (TWi-2 * TWi), where "^" indicates exponentiation. And the resulting function value F (t3) is a constant K
The ignition device for a two-cylinder internal combustion engine according to claim 1, 2 or 3, wherein the second reference position is set on condition that the number is 3 or more.