JP2020094563A - Driving device for ignition coil, and ignition system including the same - Google Patents

Abstract

To provide a driving device for an ignition coil, and an ignition system including the same capable of reducing power consumption and a heating value, so that breakage of a transistor as a switch element can be prevented.SOLUTION: A driving device for an ignition coil includes a switching element connected to a primary coil of the ignition coil, a pulse generating portion outputting a pulse signal having a prescribed pulse width as an ignition command signal, a driving portion for controlling energization or blockage of the switching element on the basis of the ignition command signal, and a timing correction circuit calculating a time period when a detection voltage according to primary current flowing to the primary coil is a reference voltage or more, and generating a timing control signal for correcting a rise timing of the ignition command signal by a value of the time period. The pulse generating portion delays a rise timing of the ignition command signal on the basis of the timing control signal.SELECTED DRAWING: Figure 3

Description

The present invention relates to a drive device (igniter) for an engine ignition coil and an ignition system including the same, and more particularly, to an ignition coil drive device using an overcurrent protection circuit and an ignition system including the same.

The ignition coil drive device is provided with various protection circuits for protecting a switching element that generates a high voltage on the secondary side of the ignition coil by turning on and off a primary current flowing through the ignition coil. This ignition coil drive device can be applied to, for example, a four-cylinder engine. Here, the ECU outputs an ignition command signal according to the operating state of the engine, and the ignition coil is driven by receiving the input of the ignition command signal. An igniter including a switching element that switches energization or interruption of the primary current based on an ignition command signal and a control unit that controls switching of energization or interruption of the switching element is connected to the ignition coil. An overcurrent protection circuit for protecting the switching element is provided in the igniter (see Patent Document 1).

Japanese Patent No. 3513063

However, even if the above-mentioned overcurrent protection circuit is used to control the switching element so that a current of a predetermined value or more does not flow, the current flowing in the switching element is limited. The potential difference becomes larger than the collector-emitter potential difference at the time of saturation, the voltage applied to the switching element becomes large, and the power consumption at the time of current limitation becomes enormous. Further, since the heat generation of the transistor, which is a switching element, depends on the power consumption, the heat generation amount of the transistor becomes enormous within the time period during which the current limitation is applied, and the transistor is destroyed in a few seconds.

An object of the present invention is to provide an ignition coil drive device that can reduce power consumption and heat generation amount and can prevent destruction of a transistor, which is a switch element, and an ignition system including the ignition coil drive device.

An ignition system according to the present invention includes a switching element connected to a primary coil of an ignition coil, a pulse generator that outputs a pulse signal having a predetermined pulse width as an ignition command signal, and the ignition command signal based on the ignition command signal. A drive unit for controlling energization or interruption energization of the switching element, and a time period during which the detected voltage corresponding to the primary current flowing through the primary coil is equal to or higher than a reference voltage is calculated, and the ignition command signal is output for the value of the time period And a timing correction circuit that generates a timing control signal that corrects the rising timing of the ignition command signal. The pulse generation unit delays the rising timing of the ignition command signal based on the timing control signal.

According to the ignition system of the present invention, the primary current exceeds the predetermined threshold value by delaying the rising timing of the ignition command signal that controls the energization and interruption of the primary current flowing through the primary coil after the second time. There is no. Therefore, since the time period during which the overcurrent protection function is working becomes zero, the power consumption and the heat generation amount can be reduced, and it is possible to prevent the transistor, which is a switch element, from being destroyed.

1 is a perspective view showing an external appearance of an internal combustion engine ignition device 1 according to a first embodiment of the present invention. It is a block diagram which shows the component of the ignition system 10 provided with the ignition device 1 of FIG. 3 is a timing chart of each signal showing the operation of the ignition system 10 of FIG. 2. It is a block diagram which shows the component of the ignition system 10A which concerns on Embodiment 2 of this invention. 9 is a timing chart for explaining the operation of the three-cylinder engine according to the third embodiment of the present invention.

Embodiments according to the present invention will be described below with reference to the drawings.

Embodiment 1.
FIG. 1 is a perspective view showing an external appearance of an internal combustion engine ignition device 1 according to a first embodiment of the present invention. The ignition device 1 for an internal combustion engine of FIG. 1 includes a connector portion 12, a coil housing portion 14, a fixed flange 15, and a high pressure output portion 16. Here, the connector portion 12, the coil accommodating portion 14, the fixed flange 15, and the high voltage output portion 16 are integrally formed of thermoplastic resin (insulating resin). Here, the internal combustion engine ignition device 1 of FIG. 1 ignites (sparks) a spark plug 6 (see FIG. 2) arranged in a cylinder (not shown) to start and rotate the engine.

A plurality of connector terminals are provided inside the shell-like body in the connector section 12 of FIG. 1 and are connected to an in-vehicle electronic device such as an ECU (Engine Control Unit) 4 (see FIG. 2) via a harness (not shown). .. As a result, the connector section 12 is wired to the in-vehicle electronic device, and an ignition command signal, power source power, etc. are applied.

Further, in the ignition device 1 of FIG. 1, the housing for housing the coil assembly 11 is arranged so as to close the open end of the plug hole. Therefore, the connector portion 12 provided in this housing is provided at a height that secures a work space so that the attachment/detachment work with the harness of the connection partner can be easily performed. Here, the engine is provided with a plug hole for each cylinder, and the spark plug 6 (see FIG. 2) is inserted into this plug hole. A mixed gas of air and a fuel such as gasoline is supplied to each cylinder of the engine through an air cleaner and an intake manifold, and the engine is started by igniting a spark plug 6 (see FIG. 2) at an appropriate timing. Rotate.

The high-voltage output unit 16 has a high-voltage terminal (not shown) built therein and is covered with a thermoplastic resin so as to insulate the high-voltage terminal from the surroundings. However, an electric path with a high-voltage terminal is secured below the high-voltage output unit 16 and is electrically connected to the spark plug 6 (see FIG. 2) via this high-voltage terminal.

The coil housing portion 14 is formed with a thermosetting resin (for example, an epoxy resin) so as to cover the entire surface of the coil assembly (mainly the primary coil, the secondary coil, and the coil iron core). The coil assembly is insulated from each other, and the wire wire for the primary coil and the wire wire for the secondary coil are wound around the axis of the coil iron core as a reference axis. The coil housing portion 14 is kept electrically insulating by the thermosetting resin even when a high voltage is generated from the coil assembly.

In the coil housing portion 14 of FIG. 1, the built-in substrate of the ignition coil driving device (igniter) 2 is vertically arranged. The ignition coil driving device 2 has a plurality of terminals, and the terminals are wired to connector terminals and the like.

The fixed flange 15 is integrally formed with the coil housing portion 14 at a position adjacent to the coil housing portion 14. The fixing flange 15 has a tongue-like shape, and a metal bush 15a made of aluminum or the like is embedded at a predetermined position. The metal bush 15a is a hollow tube into which a fixing bolt can be inserted, and is fixed to an engine block (not shown) by the fixing bolt.

FIG. 2 is a block diagram showing the components of an ignition system 10 including the ignition device 1 of FIG. The ignition system 10 of FIG. 2 includes an ignition device 1, an ECU 4 that generates an ignition command signal DS that controls the ignition device 1, and an ignition plug 6.

The ECU 4 of FIG. 2 includes a pulse generation unit 40 and a timing correction circuit 41 that generates a timing control signal TCS that corrects the rising timing of the ignition command signal DS. Here, the timing correction circuit 41 includes a delay signal generation unit 41b and a counter 41a. The pulse generation unit 40 uses a predetermined pulse corresponding to an engine parameter based on various signals from each sensor that detects a parameter indicating the engine operating state (warm-up state, engine load, engine rotation speed, etc.). A pulse signal having a width is output as the ignition command signal DS. Here, the ECU 4 includes a CPU that performs control processing and arithmetic processing related to engine control, various memories that store and retain data and programs necessary for engine control, and the pulse generation unit 40 uses the CPU processing result. Based on the above, a pulse signal having a predetermined pulse width according to the engine parameter is generated and output as the ignition command signal DS.

The ignition device 1 of FIG. 2 is configured to include an ignition coil drive device (igniter) 2, an ignition coil 5, and a power supply unit 7 whose negative (−) side terminal is grounded. Here, the ignition coil drive device 2 has four connector terminals: a primary current input terminal B, a ground terminal G, a signal input terminal S, and a signal output terminal R. The ignition coil 5 includes a primary coil L1, a secondary coil L2, and an iron core. One end of the primary coil L1 is connected to one end of the secondary coil L2 and the positive (+) side terminal of the power supply unit 7, and the other end of the primary coil L1 is isolated via a primary current input terminal as described later. It is connected to the collector terminal of a gate bipolar transistor (hereinafter, simply referred to as “IGBT”) 20. The other end of the secondary coil L2 is connected to the spark plug 6.

The ignition coil drive device 2 includes a current detection circuit 3 that detects a voltage corresponding to the primary current I1 flowing through the primary coil L1, an IGBT 20, and a drive unit 21 that controls a switching operation of the IGBT 20. .. Further, the current detection circuit 3 includes a power supply 31 having the reference voltage Vref, a comparator 30, and a resistor 32 that detects a current flowing through the IGBT 20. Here, one end of the resistor 32 is connected to the emitter terminal E of the IGBT 20, and the other end of the resistor 32 is grounded via the ground terminal G of the ignition coil driving device 2.

The comparator 30 inputs the value of the voltage difference across the resistor 32 (detection voltage corresponding to the primary current I1 flowing through the primary coil L1) corresponding to the current I1 flowing through the IGBT 20 to the non-inverting input terminal, and the value of the reference voltage Vref. Is input to the inverting input terminal. Here, the comparator 30 compares the voltage difference between both ends of the resistor 32 and the value of the reference voltage Vref to generate the comparison result signal CO, and the comparison result signal CO is countered via the signal output terminal R. 41a. That is, the comparator 30 outputs a high level signal (H) as the comparison result signal CO when the voltage difference across the resistor 32 is larger than the reference voltage Vref, and the voltage difference across the resistor 32 is less than or equal to the reference voltage Vref. At this time, a low level signal (L) is output as the comparison result signal CO. Further, at least one of the plurality of connector terminals described in FIG. 1 is a connector terminal that outputs the comparison result signal CO.

The drive unit 21 inputs the ignition command signal DS from the pulse generation unit 40 via the signal input terminal S, and controls energization or interruption of the IGBT 20 based on the ignition command signal DS.

The counter 41a included in the timing correction circuit 41 counts up in a predetermined cycle, starts counting when the detected voltage becomes equal to or higher than the reference voltage Vref, and ends counting when the ignition command signal DS that is a pulse signal becomes a low level signal. Then, the count value is generated, and the count value is output to the delay signal generation unit 41b. Here, the counter 41a starts counting and generates a count value based on the comparison result signal CO. Further, the delay signal generation unit 41b included in the timing correction circuit 41 calculates the time period T based on the input count value, generates the timing control signal TCS indicating the time period T, and outputs the timing control signal TCS. The TCS is output to the pulse generator 40. Here, the timing correction circuit 41 calculates the time period T in which the detected voltage corresponding to the primary current I1 flowing through the primary coil L1 is equal to or higher than the reference voltage Vref, and the ignition command signal DS is output by the value of the time period T. The timing control signal TCS that delays the rising timing is generated, and the timing control signal TCS is output to the pulse generation unit 40.

A storage unit may be provided in the ignition system 10 and configured to store the value of the time period T. In this case, the delay time generation unit 41b takes in the value of the time period T stored in the storage unit as necessary, and generates and outputs the timing control signal TCS based on the value of the taken time period T. May be configured to do so. Here, the storage unit includes a hard disk (HDD), a flash memory, a non-volatile recording medium such as a solid state drive (SSD), and the like.

The pulse generator 40 delays the rising timing of the ignition command signal DS by the value of the time period T based on the timing control signal TCS.

The drive unit 21 controls the voltage of the control terminal of the IGBT 20 based on the comparison result signal CO so that the primary current I1 does not exceed a predetermined threshold value. That is, the drive unit 21 functions as an overcurrent protection circuit.

The operation of the ignition system 10 configured as above will be described below.

FIG. 3 is a timing chart of each signal showing the operation of the ignition system 10 of FIG. Here, FIG. 3A is a timing chart illustrating the operation of the ignition system 10 when the engine is started and the ignition command signal DS that is the first (first) pulse signal is input to the drive unit 21. 3B is a timing chart illustrating the operation of the ignition system 10 when the ignition command signal DS, which is a pulse signal for the second time and thereafter, is input to the drive unit 21 after the engine is started.

3A and 3B are a time axis waveform diagram showing a change in the amplitude level (high level or low level) of the ignition command signal DS with respect to time t, and a time axis waveform diagram of the ignition command signal DS, respectively. And a time axis waveform diagram showing a change in the amplitude level of the primary current I1 flowing through the primary coil L1 with respect to time t, and a time axis waveform diagram of the ignition command signal DS and an elapsed time axis in common. A time axis waveform diagram showing a change in the amplitude level of the secondary voltage V2 induced in the next coil L2 with respect to time t is shown.

As shown in FIG. 3A, in the first one-pulse signal, the ignition command signal DS input to the drive unit 21 that controls energization and interruption of the primary current I1 flowing through the primary coil L1 is from the time t0 to the time t2. Is a high level signal. Here, at time t0, the IGBT 20 is turned on, the energization of the primary current I1 flowing through the primary coil L1 is started, and the primary current I1 gradually increases. Next, at time t1, the primary current I1 reaches a predetermined threshold value, and the overcurrent protection function works so that the primary current I1 exceeding the threshold value does not flow. At this time, the timing correction circuit 41 calculates the time period T during which this protection function has worked.

Next, at time t2, the ignition command signal DS becomes low level, the IGBT 20 is turned off, and the primary current I1 becomes zero. When the primary current I1 suddenly changes, the secondary coil L2 is correspondingly excited and a high voltage of several hundred V is generated. Upon receiving this high voltage, spark discharge is generated in the spark plug 6. Next, the operation when the second and subsequent pulse signals are input will be described with reference to FIG.

As shown in FIG. 3B, the rising timing of the ignition command signal DS after the second time is delayed by the value of the time period T calculated by the first one pulse signal, and the IGBT 20 is turned on at the time t3. Energization of the primary current I1 is started. Then, at the time t2, the IGBT 20 is turned off and the primary current I1 is cut off to become zero. When the primary current I1 suddenly changes, the secondary coil L2 is correspondingly excited and a high voltage of several hundred V is generated. Upon receiving this high voltage, spark discharge is generated in the spark plug 6.

According to the ignition system 10 according to the above-described embodiment, the time period T in which the overcurrent protection function is actually operated by the first pulse signal is calculated, and the calculated time period (the time period that is not actually required) is calculated. The rising timing of the ignition command signal DS for controlling energization and interruption of the primary current I1 flowing through the primary coil L1 for the second time and thereafter is delayed by the amount of time. Therefore, since the primary current I1 does not exceed the predetermined threshold value without the overcurrent protection function working for the second and subsequent pulse signals, it is possible to reduce the power consumption and the heat generation amount, and to force the switch. It is possible to prevent the transistor, which is an element, from being destroyed.

Further, the time period during which the overcurrent protection function actually operates with the first pulse signal is calculated, and the value (measured value) of the calculated time period is used to determine the rise timing of the pulse signal for the second time and thereafter. Since the delay time is determined, the time period T in which the overcurrent protection function operates after the second time can be more surely set to zero. Therefore, the power consumption can be more reliably compared with the technique of predetermining the delay time of the rise timing of the pulse signal without using the actual measurement value (for example, using the prediction value calculated in advance by the circuit time constant or the like). In addition, the amount of heat generated can be reduced, and it is possible to prevent the transistor, which is a switch element, from being destroyed.

Embodiment 2.
In the above-described embodiment, the timing correction circuit that delays the rising timing of the ignition command signal TCS by a predetermined time period is provided outside the ignition device (in the ECU 4 in the first embodiment). On the other hand, the present embodiment is characterized in that the timing correction circuit is provided in the ignition coil driving device (igniter) in the ignition device.

FIG. 4 is a block diagram showing components of the ignition system 10A according to the second embodiment of the present invention. The ignition system 10A of FIG. 4 is different from the ignition system 10 of FIG. 2 in that an ECU 4A is provided instead of the ECU 4 and an ignition device 1A is provided instead of the ignition device 1. Here, the ECU 4A differs from the ECU 4 of FIG. 2 in that the timing correction circuit 41 is omitted. Further, the ignition device 1A of FIG. 4 is different from the ignition device 1 of FIG. 2 in that an ignition coil drive device 2A is provided instead of the ignition coil drive device 2. Further, the ignition coil drive device 2A of FIG. 4 is different from the ignition coil drive device 2 of FIG. 2 in that a timing correction circuit 41A is further provided between the current detection circuit 3 and the ECU 4.

The timing correction circuit 41A of FIG. 4 is configured to include a counter 41Aa and a delay signal generation unit 41Ab.

The counter 41Aa counts up in a predetermined cycle, starts counting when the detected voltage becomes equal to or higher than the reference voltage Vref, and ends counting when the ignition command signal DS that is a pulse signal becomes a low level signal to generate a count value. , And outputs the count value to the delay signal generation unit 41Ab. Here, the counter 41Aa starts counting and generates a count value based on the comparison result signal CO.

The delay signal generation unit 41Ab calculates the time period T based on the input count value, generates the timing control signal TCS indicating the time period T, and outputs the timing control signal TCS via the signal output terminal R. And outputs it to the pulse generator 40. Here, the timing correction circuit 41A calculates the time period T in which the detected voltage corresponding to the primary current I1 flowing through the primary coil L1 is equal to or higher than the reference voltage Vref, and the ignition command signal DS is output by the value of the time period T. The timing control signal TCS that delays the rising timing is generated, and the timing control signal TCS is output to the pulse generation unit 40.

The ignition system 10A according to the present embodiment performs the same operation as the ignition system 10 according to the above-described first embodiment, and can obtain the same operational effect.

Embodiment 3.
In a multi-cylinder engine having a plurality of cylinders, the current increase rate of the primary current may vary due to manufacturing variations of the ignition coil connected to each cylinder. As described below, according to the present embodiment, it is possible to make the magnitude of the primary current I1 constant even if there is a variation in the current increase rate due to this manufacturing variation.

In the present embodiment, a multi-cylinder engine having three cylinders (first cylinder, second cylinder, and third cylinder) will be described as an example, but the present invention is not limited to this, and a multi-cylinder engine having a plurality of cylinders. It can be applied to a cylinder engine. Here, the ignition plug of each cylinder is ignited using the ignition system 10 or the ignition system 10A described above.

FIG. 5 is a timing chart for explaining the operation of the three-cylinder engine according to the third embodiment of the present invention. In FIG. 5, the primary current flowing through the primary coil L1 when the ignition command signal DS, which is the first (first) pulse signal for igniting the ignition plug for each cylinder of the three-cylinder engine, is input to the drive unit 21. The change in the amplitude level of I1 over time t is shown. Here, changes in the primary current I1 flowing through the primary coil L1 in the first to third cylinders are shown as reference numerals #1, #2, and #3, respectively. As in the first and second embodiments described above, in the first one-pulse signal, the ignition command signal DS input to the drive unit 21 that controls the energization and interruption of the primary current I1 flowing in the primary coil L1 is It is a high level signal from time t0 to time t2.

The change in the primary current I1 in the first cylinder is indicated by reference numeral #1. Here, at time t0, the IGBT 20 is turned on, the energization of the primary current I1 flowing through the primary coil L1 is started, and the primary current I1 gradually increases. Next, at time t1a, the primary current I1 reaches the predetermined threshold value Ith, and the overcurrent protection function works so that the primary current I1 that exceeds the threshold value Ith does not flow. At this time, the timing correction circuit 41 calculates the time period T1 during which this protection function has worked.

Further, the change in the primary current I1 in the second cylinder is indicated by reference numeral #2. Here, at time t0, the IGBT 20 is turned on, the energization of the primary current I1 flowing through the primary coil L1 is started, and the primary current I1 gradually increases. Next, at time t1b, the primary current I1 reaches the predetermined threshold value Ith, and the overcurrent protection function works so that the primary current I1 that exceeds the threshold value Ith does not flow. At this time, the timing correction circuit 41 calculates the time period T2 during which this protection function has worked.

Further, the change in the primary current I1 in the third cylinder is indicated by reference numeral #3. Here, at time t0, the IGBT 20 is turned on, the energization of the primary current I1 flowing through the primary coil L1 is started, and the primary current I1 gradually increases. Next, at time t2, the primary current I1 reaches the predetermined threshold value Ith, so that the overcurrent protection function does not work so that the primary current I1 that exceeds the threshold value Ith does not flow. Therefore, the timing correction circuit 41 calculates the time period during which this protection function has worked as zero.

Next, at time t2, the ignition command signal DS becomes low level, the IGBT 20 is turned off, and the primary current I1 becomes zero. When the primary current I1 suddenly changes, the secondary coil L2 is correspondingly excited and a high voltage of several hundred V is generated. Upon receiving this high voltage, spark discharge is generated in the spark plug 6. Hereinafter, the operation when the pulse signal from the second time onward is input will be described for each of the first cylinder, the second cylinder, and the third cylinder.

In the first cylinder, the rising timing of the ignition command signal DS after the second time is delayed by the value of the time period T1 calculated by the first one-pulse signal, and the time when the IGBT 20 is turned on and the energization of the primary current I1 is started. Are delayed by the time period T1. Then, at the time t2, the IGBT 20 is turned off and the primary current I1 is cut off to become zero. When the primary current I1 suddenly changes, the secondary coil L2 is correspondingly excited and a high voltage of several hundred V is generated. Upon receiving this high voltage, spark discharge is generated in the spark plug 6.

In the second cylinder, the rising timing of the ignition command signal DS after the second time is delayed by the value of the time period T2 calculated by the first one-pulse signal, and the time when the IGBT 20 is turned on and the energization of the primary current I1 is started. Is delayed by the time period T2. Then, at the time t2, the IGBT 20 is turned off and the primary current I1 is cut off to become zero. When the primary current I1 suddenly changes, the secondary coil L2 is correspondingly excited and a high voltage of several hundred V is generated. Upon receiving this high voltage, spark discharge is generated in the spark plug 6.

In the third cylinder, the rising timing of the ignition command signal DS after the second time is the same as the rising timing of the first pulse. Therefore, the time when the IGBT 20 is turned on and the conduction of the primary current I1 is started is not delayed. Then, at the time t2, the IGBT 20 is turned off and the primary current I1 is cut off to become zero. When the primary current I1 suddenly changes, the secondary coil L2 is correspondingly excited and a high voltage of several hundred V is generated. Upon receiving this high voltage, spark discharge is generated in the spark plug 6.

According to the multi-cylinder engine according to the above-described embodiment, the primary current I1 is predetermined even if the overcurrent protection function that prevents the overcurrent from flowing in the transistor that controls the current flowing in the primary current I1 of each cylinder does not work. Does not exceed the threshold value Vth. Therefore, since the overcurrent protection function does not work for the current flowing through the primary coil L1 for each cylinder, the power consumption of the engine as a whole can be reduced.

Further, even if there is a variation in the current increase rate of the primary current I1 due to a variation in the manufacturing of the coil for each cylinder, the magnitude of the primary current I1 for each cylinder can be made constant. Therefore, the variation in the combustion state of each cylinder is suppressed, and the exhaust gas performance can be improved.

Further, since the primary current I1 for each cylinder does not exceed the predetermined threshold value Vth, it is possible to suppress deterioration of the spark plug due to application of a high voltage to the spark plug for each cylinder. Becomes Further, since the primary current I1 for each cylinder does not exceed the predetermined threshold value Vth, it is possible to suppress thermal deterioration of the primary coil L1 for each cylinder.

The above-described embodiment is merely an example, and various modifications can be made without departing from the scope of the present invention.

1, 1A Ignition device 2, 2A Ignition coil drive device 3 Current detection circuit 4 ECU
5 Ignition coil 6 Spark plug 7 Power supply part 11 Coil assembly 12 Connector part 14 Coil housing part 15 Fixed flange 16 High voltage output part 20 Insulated gate bipolar transistor (IGBT)
21 Drive Unit 30 Comparator 31 Power Supply 32 Resistor 40 Pulse Generation Units 41, 41A Timing Correction Circuits 41a, 41Aa Counters 41b, 41Ab Delay Signal Generation Unit

Claims (13)

A switching element connected to the primary coil of the ignition coil,
A pulse generator that outputs a pulse signal having a predetermined pulse width as an ignition command signal,
A drive unit that controls energization or interruption of the switching element based on the ignition command signal,
Timing correction for calculating a time period in which the detected voltage corresponding to the primary current flowing through the primary coil is equal to or higher than a reference voltage, and generating a timing control signal for correcting the rising timing of the ignition command signal by the value of the time period. With a circuit,
The said pulse generation part is an ignition system which delays the rising timing of the said ignition command signal based on the said timing control signal. The timing correction circuit,
A counter that counts up in a predetermined cycle, starts counting when the detected voltage becomes equal to or higher than a reference voltage, and ends counting when the pulse signal becomes a low level signal to generate a count value,
The ignition system according to claim 1, further comprising: a delay signal generation unit that calculates the time period based on the count value and generates the timing control signal indicating the time period. Further comprising a comparator for comparing the detection voltage and the reference voltage,
The comparator generates a comparison result signal by comparing the detection voltage and the reference voltage,
The ignition system according to claim 2, wherein the counter starts counting and generates the count value based on the comparison result signal. The ignition system according to claim 3, wherein the drive unit is configured as an overcurrent protection function based on the comparison result signal so that the primary current does not exceed a predetermined threshold value. Further provided with a connector section in which a plurality of connector terminals are provided,
The ignition system according to claim 3, wherein at least one of the plurality of connector terminals is a connector terminal that outputs the comparison result signal. The ignition system according to claim 1, further comprising a storage unit that stores the value of the time period. A drive device for an ignition coil of an ignition system, which delays a rising timing of an ignition command signal which is a pulse signal having a predetermined pulse width,
A switching element connected to the primary coil of the ignition coil,
Based on the ignition command signal is a pulse signal having a predetermined pulse width, a drive unit for controlling the energization or interruption energization of the switching element,
Timing correction for calculating a time period in which the detected voltage corresponding to the primary current flowing through the primary coil is equal to or higher than a reference voltage, and generating a timing control signal for correcting the rising timing of the ignition command signal by the value of the time period. And a drive device for an ignition coil including a circuit. The timing correction circuit,
A counter that counts up in a predetermined cycle, starts counting when the detected voltage is equal to or higher than a reference voltage, and ends counting when the pulse signal becomes a low level signal to generate a count value,
The ignition system according to claim 7, further comprising: a delay signal generation unit that calculates the time period based on the count value and generates the timing control signal indicating the time period. Further comprising a comparator for comparing the detection voltage and the reference voltage,
The comparator generates a comparison result signal by comparing the detection voltage and the reference voltage,
9. The ignition coil drive device according to claim 8, wherein the counter starts counting based on the comparison result signal to generate the count value. The drive device for an ignition coil according to claim 9, wherein the drive unit is configured as an overcurrent protection function based on the comparison result signal so that the primary current does not exceed a predetermined threshold value. Further provided with a connector section in which a plurality of connector terminals are provided,
The ignition coil drive device according to any one of claims 7 to 10, wherein at least one of the plurality of connector terminals is a connector terminal that outputs the timing control signal. The drive device for an ignition coil according to claim 7, further comprising a storage unit that stores the value of the time period. An ignition device comprising the ignition coil drive device according to any one of claims 7 to 12, and an ignition coil.

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