JP2013108383A - Method of controlling ignition timing of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems in a structure for suppressing occurrence of knocking, if knocking is detected, by correcting ignition timing of a cylinder where the knocking occurs to a retarding side: that since an interval between cycles gets narrower if engine speed rises, the correction to the retarding side is too late for the time to start supplying power to a cylinder to be ignited next and the retard control cannot be reflected; that when the engine is rotating at high speed, the temperature rises if the knocking occurs during high speed rotation because combustion takes place with a thin fuel-to-air mixture, resulting in melt of a piston or the like; and that, thus the knocking which occurs during the high-speed rotation of the engine has higher risks of overheat or damage of the engine than the knocking occurring at low-speed rotation.SOLUTION: When a knocking detecting means detects the knocking of a first cylinder, and it is determined that an ignition signal for inhibiting the occurrence of the knocking cannot be reflected from an ECU for a second cylinder, timing of an ignition coil for terminating the power supply to the second cylinder is delayed to extend ON-time of the ignition signal.

Description

The present invention relates to an ignition timing control method for a combustion state of an internal combustion engine such as an automobile engine, and more particularly to an ignition control method for knocking.

Conventionally, metallic noises and vibrations generated by internal combustion engines are called knocking (hereinafter referred to as “knock”). The cause of knocking is that the ignition timing is too early, the compression ratio is too high, or an extremely thin air-fuel mixture. There is a risk that combustion by the engine will be increased, leading to engine blow. As a countermeasure against knocking, it is known that when the occurrence of knocking is detected, the ignition timing of the cylinder in which knocking has occurred is corrected to the retard side to suppress the occurrence of knocking. There has been proposed a system in which the ignition timing of all cylinders is uniformly retarded when knocking occurs in any of the cylinders. For example, Japanese Patent Laid-Open No. 58-165574 (hereinafter referred to as “Patent Document 1”) is known. It has been.

In Patent Document 1, a knocking detection circuit that detects a knocking state from a signal representing engine vibration, a crank angle sensor that generates a signal corresponding to the crank angle of the engine, and various operating state control devices that govern the operating state of the engine; The cylinder in which knocking has occurred is discriminated based on the output of the crank angle sensor and the output of the knocking detection circuit, and when the output of the knocking detection circuit is below a predetermined value, the cylinder in which knocking has been controlled by the operating state control device A control apparatus for a multi-cylinder engine has been proposed that includes a cylinder control correction circuit that corrects only the control and corrects the control for all cylinders when the output is greater than or equal to a predetermined value.

JP 58-165574 A

However, the above-described conventional control device for an internal combustion engine has the following problems. That is, in Patent Document 1, when knocking occurs in any of a plurality of cylinders, the ignition timing of all the cylinders is uniformly retarded to suppress knocking, but the engine speed increases. Accordingly, the interval between each cycle becomes fast, so that it is not in time for the energization start time of the cylinder to be ignited next, and the retard control cannot be reflected. In addition, when the engine is rotating at high speed, combustion is performed with a thin fuel mixture, so that when the engine knocks at high speed, the temperature rises and the piston melts. As described above, the knock that occurs when the engine rotates at a high speed is often a dangerous knock that causes the engine to overheat or break as compared with the knock that occurs at a low speed.

The present invention has been made in view of the above problems, and aims to provide an ignition timing control method for an internal combustion engine that can suppress the occurrence of knocking from a cylinder to be ignited next even if the engine speed increases. To do.

In order to solve the above problems, the present invention is configured as follows. That is, an internal combustion engine having a plurality of cylinders, an ECU that performs electrical control of the internal combustion engine, an ignition coil that includes a primary coil and a secondary coil that ignite the internal combustion engine, and a knock of the internal combustion engine Knock detection means for detecting occurrence, and when the knock detection means detects knocking from any cylinder of the internal combustion engine, the ignition signal of the ignition coil from the ECU is retarded to knock. In the internal combustion engine ignition timing control method for suppressing the generation, the knock detection means detects the knocking of the first cylinder, and the ignition signal for suppressing the knocking from the ECU for the second cylinder cannot be reflected. When it is determined, the internal combustion engine characterized in that the energization end time for the second cylinder of the ignition coil is retarded and the on-time of the ignition signal is extended. And the ignition timing control method.

In the above configuration, the knock detection means may be a knock sensor that detects vibrations of the internal combustion engine or an ion current detection device that detects an ionic current generated during combustion of the internal combustion engine. Further, the delay of the energization end time of the ignition coil may be performed in a range that does not cause a problem in the output of the internal combustion engine, and the delay of the energization end time of the ignition coil is the discharge performance of the ignition coil. You may carry out in the range within the limits. Further, the internal combustion engine may be a three-cylinder engine.

As described above, when the knock detection unit detects knocking of the first cylinder and determines that the ignition signal for suppressing the occurrence of knocking from the ECU for the second cylinder cannot be reflected, the 2 of the ignition coil By delaying the energization end time for the second cylinder and extending the on time of the ignition signal, even if the engine speed increases, the occurrence of knocking from the next cylinder to be ignited is suppressed and the engine is protected. An ignition timing control method for an internal combustion engine that can prevent loss of output torque can be realized.

Further, the knock generated when the internal combustion engine rotates at a high speed is more dangerous than the knock generated when the internal combustion engine rotates at a low speed.

1 is a diagram showing a configuration of an internal combustion engine according to a first embodiment of the present invention. 1 is a circuit diagram of an ignition device for an internal combustion engine according to a first embodiment. It is a time chart which shows the combustion period and ignition signal of each cylinder of the internal combustion engine which is a 1st Example. 3 is a time chart showing knock determination control for combustion of cylinder # 1 of the internal combustion engine according to the first embodiment. 3 is a time chart showing ignition timing control performed on an ignition signal of a cylinder # 2 with respect to combustion of a cylinder # 1 of the internal combustion engine according to the first embodiment. It is a flowchart showing the ignition timing control with respect to knock of the internal combustion engine which is a 1st Example. It is a figure which shows the structure of the internal combustion engine which is the 2nd Example of this invention. It is a circuit diagram of the ignition device of the internal combustion engine which becomes a 2nd Example. It is a time chart which shows the knock determination control with respect to combustion of cylinder # 1 of the internal combustion engine which is a 2nd Example. It is a time chart which shows the ignition timing control performed to the ignition signal of cylinder # 2 with respect to combustion of cylinder # 1 of the internal combustion engine which is a 2nd Example. It is a flowchart showing the ignition timing control with respect to knock of the internal combustion engine which is a 2nd Example.

An example showing an embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a diagram showing a configuration of an internal combustion engine according to a first embodiment of the present invention, FIG. 2 is a circuit diagram of an ignition device of the internal combustion engine, and a time chart showing a combustion period and an ignition signal of each cylinder of the internal combustion engine FIG. 3 is a time chart showing knock determination control for combustion of cylinder # 1 of the internal combustion engine. FIG. 4 is a time chart showing ignition timing control performed on the ignition signal of cylinder 2 for combustion of cylinder 1 of the internal combustion engine. FIG. 5 is a flow chart showing ignition timing control for knocking of the internal combustion engine, and FIG.

1 and 2, the internal combustion engine is a three-cylinder engine including three cylinders 30, and an intake for supplying a mixture of fuel and air into a cylinder 32 formed for each cylinder 30. A manifold 36 is provided, an injection 50 for injecting fuel into the intake manifold 36, and an exhaust manifold 42 for discharging exhaust gas from the cylinder 32 are provided. Further, the intake manifold 36 is provided with an intake valve 38 for adjusting the intake amount into the cylinder 32, and the exhaust manifold 42 is provided with an exhaust valve 44 for adjusting the exhaust amount from the cylinder 32. Further, in order to open and close the intake valve 38 and the exhaust valve 44, an intake cam 40 is provided on the intake valve 38 side, and an exhaust cam 46 is provided on the exhaust valve 44 side.

The internal combustion engine includes a piston 34 for compressing the air-fuel mixture in the cylinder 32, and a crank 48 for converting the vertical motion caused by the combustion in the cylinder 32 transmitted to the piston 34 into a rotational motion. Further, the crank 48, the intake cam 40, and the exhaust cam 46 are driven in conjunction with a timing belt.

The internal combustion engine includes an ignition coil 10 for boosting the voltage of a battery 22 provided in the engine room and an ignition plug 20 for igniting an air-fuel mixture in the cylinder 32. The ignition coil 10 has a primary winding. A primary coil 12 wound with a wire, a secondary coil 14 wound with a secondary winding, an iron core 16, and an igniter comprising an FET 18 for supplying an ignition signal to the ignition coil 10. Further, the engine room is provided with an ECU 54 that performs electrical control of the internal combustion engine, the ECU 54 controls the amount of fuel injected from the injection 50, and the ECU 54 is connected to the ignition coil 10, An ignition signal is supplied from the ECU 54 to the ignition coil 10 in accordance with the combustion cycle of the internal combustion engine.

In addition, when the ignition from the ignition coil 10 is too early in the internal combustion engine, the compression ratio in the cylinder 32 is too high, or the metallic sound generated by the internal combustion engine during the operation in the case of lean combustion, etc. Further, a knock sensor 52 for detecting knocking that vibrates (hereinafter referred to as “knock”) is provided, and the knock sensor 52 is connected to the ECU 54. Further, the knock sensor 52 is directly attached to the engine block of the internal combustion engine, and when a knock occurs, a piezoelectric element in the knock sensor 52 detects vibration and transmits a sensor signal to the ECU 54.

Next, in FIG. 3, the combustion period of cylinder # 1, cylinder # 2, and cylinder # 3 constituting the internal combustion engine, the ignition signal for cylinder # 1, the ignition signal for cylinder # 2, and the ignition for cylinder # 3 The signal has a waveform as shown by the solid line in FIG. 3, and combustion in the cylinder 32 of the cylinder # 1 and cylinder # 2 of the internal combustion engine and the cylinder # 3 is performed at equal intervals. the cylinder # 2, the TDC the ♯1 ignition signal and the # 2 ignition signal to combustion (top dead center) and later is started, the ♯3 ignition signal T _oN time the ignition coil of the cylinder ♯3 Supplying to 10. Further, when the rotational speed of the internal combustion engine increases, the cycle of the cylinder # 1, the cylinder # 2, and the cylinder # 3 is advanced, and the combustion period of the cylinder # 1, the cylinder # 2, and the cylinder # 3 is also increased. Therefore, the # 1 ignition signal, the # 2 ignition signal, and the # 3 ignition signal are also advanced, and the energization time T _{ON of the} # 1 ignition signal, the # 2 ignition signal, and the # 3 ignition signal is advanced. Will also be shorter.

Further, when combustion of the cylinder # 1 is started before the TDC of the cylinder # 1 and knocking occurs in the cylinder # 1, the # 2 ignition signal T _ON is indicated as indicated by a broken line of the # 2 ignition signal. Is set to the # 2 ignition signal T _ON in the hatched portion that is retarded in the direction of the arrow A to suppress the occurrence of knock. Further, if the occurrence of knocking is suppressed after retarding the # 2 ignition signal T _ON in the direction of arrow A, the hatched # 2 ignition signal T _ON is advanced to the initial ignition signal indicated by the solid line. ing.

FIG. 4 also shows the time taken to detect the vibration of the internal combustion engine by the knock sensor 52 and to transmit a sensor signal from the knock sensor 52 to the ECU 54 with respect to the combustion of the internal combustion engine. As the operation of knock determination control, the knock sensor 52 detects the vibration of the internal combustion engine that is generated when combustion is started before the TDC of the cylinder # 1, and the knock sensor 52 detects the vibration of the internal combustion engine. Is detected, the sensor signal is transmitted from the knock sensor 52 to the ECU 54.

The # 1 ignition signal, the # 2 ignition signal, and the # 3 ignition signal are advanced when the rotational speed of the internal combustion engine increases, and the # 1 ignition signal, the # 2 ignition signal, and the # 3 ignition signal are advanced. of it energization is shortened time T _oN, the order from the knock sensor 52 the internal combustion engine vibration detection and the knock sensor 52 according to a predetermined time required to transmit a sensor signal to the ECU 54, the rotational speed of the internal combustion engine is increased Then, as shown in FIG. 3, the ECU 54 starts supplying the # 2 ignition signal. In such a state, even if the knock sensor 52 detects a knock generated in the internal combustion engine, the # 2 ignition signal T _ON cannot be retarded, and the ignition control for suppressing the occurrence of the knock is performed. Reflected after the # 3 ignition signal.

FIG. 5 shows the time taken to detect the vibration of the internal combustion engine by the knock sensor 52 and to transmit a sensor signal from the knock sensor 52 to the ECU 54 with respect to the combustion of the cylinder # 1 of the internal combustion engine. . As the operation of the ignition timing control, when the ECU 54 starts supplying the # 2 ignition signal as shown in FIG. 3 when the rotational speed of the internal combustion engine increases, only the energization end time of the # 2 ignition signal is displayed. Is retarded in the direction of arrow B so that the # 2 ignition signal T _ON is made the # 2 ignition signal T _ON ′ with the hatched portion extended, thereby suppressing the occurrence of knocking. Further, when the occurrence of knocking is suppressed after retarding only the energization end time of the # 2 ignition signal in the direction of arrow B, the initial # 2 ignition signal T _ON ′ indicated by a solid line is shown by the solid line. It is advanced to # 2 ignition signal T _ON .

Further, the ECU 54 retards only the energization end time of the ignition signal within the limit range of the discharge energy from the ignition coil 10 that is the minimum necessary for ignition of the internal combustion engine, and extends the ignition signal T _ON. T _ON ' Further, as the first cylinder, the second cylinder, and the third cylinder in the order in which the cylinder 30 of the internal combustion engine burns, the first cylinder in which knocking is detected is the first cylinder, and the ignition signal energization end time only The cylinder that retards the angle is implemented as the second cylinder.

Next, the operation of the ignition timing control method for the internal combustion engine will be described with reference to FIG. In FIG. 6, the knock sensor 52 detects vibration generated in the internal combustion engine (S1), determines whether the knock sensor 52 has detected vibration (S2), and the knock sensor 52 vibrates in (S2). Is detected, the knock sensor 52 transmits the sensor signal to the ECU 54 (S3), and the ECU 54 is based on the sensor signal from the knock sensor 52. wherein the ignition signal supplied to the second cylinder of the internal combustion engine calculates the amount to be retarded of the internal combustion engine knock suppressing ignition signal T _ON generation of the ignition signal T _ON is the first Te It is calculated from the time difference between the energization end time of the ignition signal for the cylinder and the energization end time of the ignition signal for the second cylinder (S4).

Further, the ECU 54 determines whether or not the retard angle of the ignition signal T _ON calculated in (S4) can be actually reflected on the next cylinder to be burned, that is, ignites the cylinder to be burned next. It is determined whether or not the signal supply has started (S5). In (S5), the ECU 54 determines the retard angle of the ignition signal T _ON calculated in (S4) for the cylinder that is actually to be burned next. When it is determined that the ignition signal can be reflected, that is, when it is determined that the supply of the ignition signal to the cylinder where combustion is performed next is not started, the ECU 54 reflects the ignition signal T _ON calculated in (S4). (S6).

Further, when it is determined in (S5) that the ECU 54 cannot reflect the retard angle of the ignition signal T _ON calculated in (S4) to the cylinder where the next combustion is actually performed, that is, the next combustion is performed. When it is determined that the supply of the ignition signal to the cylinder is started, the ECU 54 reflects the ignition signal T _ON ′ obtained by extending only the energization end time of the ignition signal T _ON calculated in (S4) ( S11).

With the above configuration, when the ECU 54 can reflect the calculated retard angle of the ignition signal T _ON to the cylinder in which combustion is actually performed next, the ECU 54 sets the ignition signal T _ON by retarding the ignition signal T _ON , When the ECU 54 cannot reflect the calculated retard angle of the ignition signal T _ON to the cylinder where the combustion is actually performed next, the ECU 54 delays only the energization end time of the ignition signal and extends the ignition signal T _ON. By setting the ignition signal T _ON ′, it is possible to suppress the occurrence of knocking as the rotational speed of the internal combustion engine increases, thereby protecting the internal combustion engine and preventing loss of output torque. In addition, knocks that occur when the internal combustion engine is rotating at high speeds are often more dangerous knocks that cause the internal combustion engine to be overheated or damaged compared to knocks that are generated when the internal combustion engine is rotating at low speeds. .

As a modification of the first embodiment, the internal combustion engine is a three-cylinder engine including three cylinders 30. However, the internal combustion engine may be implemented as long as it has a plurality of cylinders. Further, the number of knock sensors 52 attached to the engine block of the internal combustion engine may be changed to an arbitrary number depending on design circumstances. Further, the knock sensor 52 may be either a resonance type knock sensor constituted by a diaphragm and a piezoelectric element or a non-resonance type knock sensor constituted by an acceleration sensor.

The discharge performance of the ignition coil 10 is determined by the number of turns of the primary coil 12 and the secondary coil 14, and the discharge performance of the ignition coil 10 can be arbitrarily changed according to the design circumstances such as the specifications of the internal combustion engine. Also good. Further, the ECU 54 determines the retard amount of the energization end time of the ignition coil 10 when the calculated retard angle of the ignition signal T _ON cannot be reflected to the cylinder where the combustion is actually performed next. As long as there is no problem, the retard amount may be set to an arbitrary amount, and the ECU 54 does not reflect the calculated retard angle of the ignition signal T _ON to the cylinder that is actually burned next. The retard amount of the energization end time of the coil 10 may be any retard amount as long as it is within the limit range of the discharge energy of the ignition coil 10.

Next, FIG. 6 is a diagram showing a configuration of an internal combustion engine according to a second embodiment of the present invention, FIG. 8 is a circuit diagram of a combustion control device for the internal combustion engine, and combustion control for combustion of cylinder # 1 of the internal combustion engine is shown. FIG. 9 is a time chart showing, FIG. 10 is a time chart showing combustion control performed on the ignition signal of the cylinder # 2 for combustion of the cylinder # 1 of the internal combustion engine, and FIG. 10 is a flowchart showing combustion control for knocking of the internal combustion engine. 11 respectively.

In the second embodiment, when ignition from the ignition coil 10 described in the first embodiment is too early, when the compression ratio in the cylinder 32 is too high, in the case of lean combustion, etc. The rest of the structure is the same as that of the first embodiment except that the piston 34 is provided with a knock sensor 52 that detects a knock that emits metallic sound or vibration.

7 and 8, the internal combustion engine is provided with an ionic current output device 56 that detects an ionic current generated in the spark plug 20 by the combustion of the cylinder 30, and the ionic current detection device 56 includes the ignition coil. The ten secondary coils 14 are connected to the low pressure side and the ECU 54. Further, the ion current detection device 56 calculates whether knock has occurred in the internal combustion engine from the detected ion current waveform, and transmits it to the ECU 54 by CAN communication.

Next, in FIG. 9, detection of ion current generated in the spark plug 20 by the ion current detection device 56 with respect to combustion of the internal combustion engine, and determination of knock generated in the internal combustion engine from the detected ion current waveform. The time taken for the CAN communication from the ion current detection device 56 to the ECU 54 is shown. As an operation of knock determination control, the ion current detection device 56 detects an ion current generated in the spark plug 20 when combustion starts before the TDC of the cylinder # 1, and the ion current detection device 56 Is communicated from the ion current detector 56 to the ECU 54 after calculating whether the internal combustion engine is knocked from the detected ion current waveform.

The # 1 ignition signal, the # 2 ignition signal, and the # 3 ignition signal are advanced when the rotational speed of the internal combustion engine increases, and the # 1 ignition signal, the # 2 ignition signal, and the # 3 ignition signal are advanced. Although also shortened the energization time T _oN, generated in the detection and the internal combustion engine from the detected ion current waveform of the ion current generated in the spark plug 20 by the ion current detection device 56 with respect to the combustion of the internal combustion engine The knock determination is calculated and the time taken for the CAN communication from the ion current detection device 56 to the ECU 54 is constant. Therefore, even if the knock generated in the internal combustion engine is detected from the ion current, the # 2 ignition signal T _ON Cannot be retarded, and the ignition control that suppresses the occurrence of knocking is reflected after the # 3 ignition signal.

In FIG. 10, the detection of ion current generated in the spark plug 20 by the ion current detection device 56 with respect to the combustion of the cylinder # 1 of the internal combustion engine and the knock generated in the internal combustion engine from the detected ion current waveform. The time taken for the CAN communication from the ion current detection device 56 to the ECU 54 is shown. As the operation of the ignition timing control, when the ECU 54 starts supplying the # 2 ignition signal as shown in FIG. 9 when the rotation speed of the internal combustion engine increases, only the energization end time of the # 2 ignition signal is displayed. the arrow C direction is retarded by the ♯2 ignition signal T _oN in the hatched portion extended ♯2 ignition signal T _oN ', thereby suppressing the occurrence of knocking. Further, when the occurrence of knocking is suppressed after retarding only the energization end time of the # 2 ignition signal in the direction of arrow B, the initial # 2 ignition signal T _ON ′ indicated by a solid line is shown by the solid line. It is advanced to # 2 ignition signal T _ON .

Further, the ECU 54 retards only the energization end time of the ignition signal within the limit range of the discharge energy from the ignition coil 10 that is the minimum necessary for ignition of the internal combustion engine, and extends the ignition signal T _ON. T _ON ' Further, as the first cylinder, the second cylinder, and the third cylinder in the order in which the cylinder 30 of the internal combustion engine burns, the first cylinder in which knocking is detected is the first cylinder, and the ignition signal energization end time only The cylinder that retards the angle is implemented as the second cylinder.

Next, the operation of the ignition timing control method for the internal combustion engine will be described with reference to FIG. In FIG. 11, the ion current detection device 56 detects an ion current generated in the spark plug 20 due to combustion of the internal combustion engine (S1), and the ion current detection device 56 detects the ion current waveform from the detected ion current waveform to the internal combustion engine. The determination whether knock has occurred is calculated (S2), and the ion current detection device 56 determines whether knock has occurred in the internal combustion engine from the calculation result in (S2) (S3), (S3). When it is determined that knock has occurred in the internal combustion engine, the first cylinder 30 is detected as the first cylinder, and CAN communication is performed from the ion current detector 56 to the ECU 54 (S4). Is an ignition signal T that suppresses the occurrence of knocking in the internal combustion engine with an ignition signal supplied to the second cylinder of the internal combustion engine based on CAN communication from the ion current detection device 56 _The amount of _ON delay is calculated, and the ignition signal T _ON is calculated from the time difference between the ignition signal energization end time for the first cylinder and the ignition signal energization end time for the second cylinder ( S5).

Further, the ECU 54 determines whether or not the retard angle of the ignition signal T _ON calculated in (S5) can be actually reflected on the next cylinder to be burned, that is, ignites the cylinder to be burned next. It is determined whether or not the signal supply has started (S6). In (S6), the ECU 54 determines the retard angle of the ignition signal T _ON calculated in (S5) for the cylinder in which combustion is actually performed next. When it is determined that the ignition signal can be reflected, that is, when it is determined that the supply of the ignition signal to the cylinder where combustion is performed next is not started, the ECU 54 reflects the ignition signal T _ON calculated in (S5). (S7).

Further, when it is determined in (S6) that the ECU 54 cannot reflect the retard angle of the ignition signal T _ON calculated in (S5) to the cylinder where the next combustion is actually performed, that is, the next combustion is performed. When it is determined that the supply of the ignition signal to the cylinder is started, the ECU 54 reflects the ignition signal T _ON ′ obtained by extending only the energization end time of the ignition signal T _ON calculated in (S5) ( S11).

With the above configuration, when the ECU 54 can reflect the calculated retard angle of the ignition signal T _ON to the cylinder in which combustion is actually performed next, the ECU 54 sets the ignition signal T _ON by retarding the ignition signal T _ON , When the ECU 54 cannot reflect the calculated retard angle of the ignition signal T _ON to the cylinder where the combustion is actually performed next, the ECU 54 delays only the energization end time of the ignition signal and extends the ignition signal T _ON. By setting the ignition signal T _ON ′, it is possible to suppress the occurrence of knocking as the rotational speed of the internal combustion engine increases, thereby protecting the internal combustion engine and preventing loss of output torque. In addition, knocks that occur when the internal combustion engine is rotating at high speeds are often more dangerous knocks that cause the internal combustion engine to be overheated or damaged compared to knocks that are generated when the internal combustion engine is rotating at low speeds. .

As a modification of the second embodiment, the internal combustion engine is a three-cylinder engine including the three cylinders 30, but may be implemented as long as the internal combustion engine has a plurality of cylinders. Further, the configuration of the ion current detection device 56 may be changed to an arbitrary configuration depending on design circumstances. Further, the discharge performance of the ignition coil 10 is determined by the number of turns of the primary coil 12 and the secondary coil 14, and the discharge performance of the ignition coil 10 is arbitrarily changed according to the design circumstances such as the specifications of the internal combustion engine. Also good.

Further, the ECU 54 determines the retard amount of the energization end time of the ignition coil 10 for the case where the calculated retard angle of the ignition signal T _ON cannot be reflected to the cylinder where the next combustion is actually performed. As long as there is no problem, the retard amount may be set to an arbitrary amount, and the ECU 54 does not reflect the calculated retard angle of the ignition signal T _ON to the cylinder that is actually burned next. The retard amount of the energization end time of the coil 10 may be any retard amount as long as it is within the limit range of the discharge energy of the ignition coil 10.

10: Ignition coil
12: Primary coil
14: Secondary coil
16: Iron core
18: FET (switching element)
20: Spark plug
22: Battery
30: Cylinder
32: Cylinder
34: Piston
36: Intake manifold
38: Intake valve
40: Intake cam
42: Exhaust manifold
44: Exhaust valve
46: Exhaust cam
48: Crank
50: Injection
52: Knock sensor
54: ECU
56: Ion current detector

Claims (5)

An internal combustion engine having a plurality of cylinders;
An ECU for electrical control of the internal combustion engine;
An ignition coil comprising a primary coil and a secondary coil for igniting the internal combustion engine;
A knock detection means for detecting the occurrence of knock in the internal combustion engine,
In the internal combustion engine ignition timing control method for suppressing the occurrence of knocking by retarding the ignition signal of the ignition coil from the ECU when the knock detection means detects knocking from any cylinder of the internal combustion engine. ,
When the knock detection means detects knocking of the first cylinder and determines that the ignition signal for suppressing the occurrence of knocking from the ECU for the second cylinder cannot be reflected, the second of the ignition coil An ignition timing control method for an internal combustion engine characterized in that the energization end time for each cylinder is retarded and the on-time of the ignition signal is extended. 2. The ignition of an internal combustion engine according to claim 1, wherein the knock detection means is a knock sensor for detecting vibration of the internal combustion engine or an ion current detection device for detecting an ion current generated during combustion of the internal combustion engine. Timing control method. The ignition timing control method for an internal combustion engine according to claim 1 or 2, wherein the delay of the energization end time of the ignition coil is performed within a range in which no problem occurs in the output of the internal combustion engine. The ignition timing control method for an internal combustion engine according to any one of claims 1 to 3, wherein the delay of the energization end time of the ignition coil is performed within a range within a limit of discharge performance of the ignition coil. 5. The ignition timing control method for an internal combustion engine according to claim 1, wherein the internal combustion engine is a three-cylinder engine.

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