JP2001304085A - Igniter for internal combution engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an igniter for an internal combustion engine capable of almost regularly maintaining magnetic flux energy accumulated in an ignition coil without depending on an individual difference in wire wound resistance of a primary winding in the ignition coil. SOLUTION: This igniter 1 for the internal combustion engine has a microcomputer 21 for maintaining a main control transistor 15 in an OFF state separately from an ECU 31. Even if the ECU 31 puts an ignition command signal IG on a high level, while the microcomputer 21 puts a current-carrying start delaying signal Sb on a high level, the main control transistor 15 is maintained in an OFF state so that a primary current i1 does not flow. The microcomputer 21 sets current-carrying time by delaying the current-carrying starting timing of the primary current i1 by a current-carrying start delaying time Ts calculated according to the detected primary current and a source voltage value, and regularly controls the magnetic flux energy accumulated in the ignition coil 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to generating a high ignition voltage in a secondary coil by interrupting a primary current flowing through a primary winding of an ignition coil, and applying the generated high ignition voltage to an ignition plug. The present invention relates to an ignition device for an internal combustion engine that generates a spark discharge between electrodes of a spark plug.

[0002]

2. Description of the Related Art Conventionally, a power supply voltage from a power supply device is applied (supplied) to a primary winding of an ignition coil, and a primary current flowing at this time is cut off after a certain period of time, so that the secondary winding of the ignition coil is turned off. 2. Description of the Related Art There is known a current cutoff type ignition device for an internal combustion engine that induces a high voltage for ignition to generate spark discharge in a spark plug.

In such a current interruption type ignition device for an internal combustion engine, the magnitude of the ignition high voltage generated in the secondary winding depends on the turns ratio of the primary / secondary winding of the ignition coil,
And the magnitude of the magnetic flux energy accumulated in the ignition coil by the current flowing through the primary winding.

[0004] Therefore, if the specifications (turn ratio) of the ignition coil are the same, the high voltage for ignition is determined by the magnetic flux energy W1 accumulated in the ignition coil. 1].
Here, L1 is the inductance of the primary winding, and I1 is the current value of the primary current when the primary current is cut off.

[0005]

(Equation 1)

[0006] The spark discharge energy W2 consumed by the spark discharge of the spark plug can be represented by [Equation 2]. Note that _CF is the stray capacitance of the circuit to which the secondary winding is connected, V2 is the ignition high voltage generated at both ends of the secondary winding, and k is a coefficient. C _F is substantially equal to the stray capacitance between the electrodes of the spark plug, and the ignition high voltage V2 has a value substantially equal to the inter-electrode voltage of the spark plug.

[0007]

(Equation 2)

Next, the spark discharge energy W2 is supplied from the magnetic flux energy W1 stored in the ignition coil.
When all of the magnetic flux energy W1 is consumed as the spark discharge energy W2, the inter-electrode voltage (ignition high voltage V2) generated between the electrodes of the spark plug has a maximum value. At this time, W1 in [Equation 1] and [Equation 2]
W2 are equal to each other, and L1, C _F ,
When k2 is a constant value and rearranged for V2, it becomes as shown in [Equation 3], and it can be seen that the ignition high voltage V2 is proportional to the primary current I1 at the time of interrupting the primary current.

[0009]

(Equation 3)

On the other hand, the primary current I1 flowing through the primary winding forming a closed loop together with the power supply device can be expressed as in [Equation 4].

[0011]

(Equation 4)

Here, E is a power supply voltage output from the power supply device, t is a primary current conduction time, R1 is a winding resistance of the primary winding, and τ is a time constant determined by L1 and R1 of the closed loop circuit. (= L1 / R1). At this time, if L1 and R1 are constant, the ignition high voltage V2 is determined by the power supply voltage E and the primary current energization time t according to [Equation 3] and [Equation 4].
Will be determined by

[0013] The conventional current interrupt type ignition device for an internal combustion engine generally uses a power supply device that outputs a constant voltage (for example, 12 (v)) as a power supply voltage as a power supply voltage. The power supply voltage E can be considered to be constant, and the magnetic flux energy accumulated in the ignition coil can be changed by changing the primary current supply time t. For this reason, in the conventional ignition device for an internal combustion engine, in order to secure a high ignition voltage at which a spark discharge can be generated, the primary current energization time t is set to be sufficiently long so that the spark discharge required for the generation of the spark discharge is made. The magnetic flux energy is configured to be stored in the ignition coil.

[0014]

However, since there is a tolerance in the winding resistance of the primary winding of the ignition coil, there is an individual difference in the winding resistance of the primary winding for each ignition coil, so that the accumulation in the ignition coil is caused. There is a possibility that the magnetic flux energy changes and the voltage value of the ignition high voltage generated when the primary current is cut off varies. That is, the tolerance of the winding resistance of the primary winding is defined as ± 10% according to JIS-D5121, and when the winding resistance R1 is changed by ± 10% with the primary current conduction time and the power supply voltage kept constant. The primary current at the time of energization cutoff varies from + 11% to -9%. This is because the current target value at the time of primary current energization cutoff is, for example, 6
In the case of [A], the fluctuation range of the current is from 6.66 to 5.
Since it is 46 [A], a difference of 1 [A] or more is generated, which greatly affects the performance (maximum secondary voltage generation ability) of the ignition coil.

If the primary current at the time of primary current supply interruption is reduced, sufficient magnetic flux energy cannot be stored in the ignition coil, and the voltage value of the ignition high voltage decreases.
There is a risk of causing a misfire that can generate a spark discharge. Also, if the primary current at the time of primary current energization cutoff increases, an excessive current will flow through the switching element connected to the primary winding to control the energization / interruption of the primary current, and the amount of heat generated by the switching element will decrease. There is a possibility that the load will increase and the life will be shortened, or the switching element will be destroyed.

The present invention has been made in view of such a problem, and the magnetic flux energy accumulated in the ignition coil can be maintained substantially constant regardless of the individual difference in the winding resistance of the primary winding in the ignition coil. An object of the present invention is to provide an ignition device for an internal combustion engine.

[0017]

SUMMARY OF THE INVENTION In order to achieve the above object, the invention according to claim 1 is directed to a primary winding in which a primary current flows when a power supply voltage is applied from a power supply device, and to an internal combustion engine. An ignition coil having a mounted ignition plug and a secondary winding forming a closed loop, and a switching means for forming a closed loop together with the primary winding and a power supply device, energizing and interrupting a primary current flowing through the primary winding, and Ignition control means for outputting an ignition command signal according to the operating state of the internal combustion engine to the switching means, and turning on and off the switching means to supply and cut off the primary current and to ignite the secondary winding. An ignition device for an internal combustion engine for generating a high voltage, comprising: a primary current detecting means for detecting a primary current flowing through a primary winding; and a primary current detecting means for detecting a primary current detected by the primary current detecting means. Based on the values, characterized in that and a current supply time control means for controlling the primary current supply time to the primary winding.

The most characteristic of the ignition device for an internal combustion engine of the present invention is that the primary current flowing through the primary winding is detected, and the primary current supply time is controlled based on the maximum value of the primary current. As described above, the energization time control means controls the primary current energization time based on the maximum value of the primary current, so that the magnetic flux energy accumulated in the ignition coil can be controlled. In other words, the energization time control means controls the primary current energization time such that, for example, when a spark discharge occurs, that is, when the primary current energization is interrupted, so that the maximum value of the primary current is constant. Even when there is variation among the individual ignition coils due to variation in inductance, the magnetic flux energy accumulated in the ignition coil can be maintained substantially constant.

Therefore, according to the ignition device for an internal combustion engine of the present invention (claim 1), it is possible to control the magnetic flux energy accumulated in the ignition coil to be substantially constant, thereby causing a misfire or an increase in the amount of heat generated in the switching element. Thus, it is possible to realize an ignition device for an internal combustion engine capable of suppressing the occurrence of the ignition.

Next, the energization time control means performs control so as to shorten the primary current energization time when the maximum value of the detected primary current is larger than a predetermined target value. If the maximum value of the detected primary current is equal to or less than the target value, the control may be performed so that the primary current conduction time is increased. That is, the target value of the maximum value of the primary current at which the magnetic flux energy stored in the ignition coil is optimal is determined in advance, and the target value is stored by comparing the detected maximum value of the primary current with the target value. It is determined whether the magnetic flux energy is excessive or insufficient.

When the detected maximum value of the primary current is larger than the target value, the magnetic flux energy accumulated in the ignition coil is excessive. The primary current value at the time of the interruption of the primary current supply is reduced, and the magnetic flux energy is reduced to approach an optimum value. At this time, for example, when a transistor including a semiconductor element is used as the switching means, the primary current is reduced, so that unnecessary heat generation of the transistor can be suppressed.

Conversely, when the detected maximum value of the primary current is equal to or less than the target value, the magnetic flux energy accumulated in the ignition coil is insufficient. The primary current value at the time of current supply interruption is increased, and the magnetic flux energy is increased to approach an optimum value. As a result, shortage of magnetic flux energy can be prevented, and occurrence of misfire can be suppressed under all operating conditions of the internal combustion engine.

By the way, in controlling the primary current energizing time, if the range (variable range) that can be set as the primary current energizing time is unlimited, if the primary current or the power supply voltage is erroneously detected due to noise or the like, this Due to the control based on the incorrect detection result, the value of the primary current supply time may diverge, and the internal combustion engine may not be able to operate normally.

Therefore, in controlling the primary current energizing time, the energizing time control means preferably controls the primary current energizing time within a range where spark discharge can be generated by the spark plug. Good. In this way, by setting the range in which the primary current energizing time is controlled to be in a range in which spark discharge can be generated by the spark plug, an inappropriate value is set for the primary current energizing time for some reason. Can be prevented. When a value outside the range in which spark discharge can be generated is set as the primary current energizing time, the spark plug is normally changed to a value within the range in which spark discharge can be generated. Should be generated.

Here, the magnitude of the primary current flowing through the primary winding is greatly affected by fluctuations in the power supply voltage (fluctuations in the power supply voltage at the time of starting the internal combustion engine and troubles of the generator). The ignition device for an internal combustion engine described above (claims 1 to 3) includes a power supply voltage detection means for detecting a power supply voltage value output from the power supply device, as described in claim 4, and includes a power supply time. The control means may control the primary current conduction time based on the maximum value of the primary current and the power supply voltage value detected by the power supply voltage detection means.

That is, by detecting not only the primary current but also the power supply voltage, the magnitude of the primary current when the primary current is cut off can be more accurately grasped, and the control of the primary current supply time can be performed accurately. Becomes possible. Incidentally, in order to control the primary current energizing time based on the detected maximum value of the primary current, it is optimal to perform the primary current detection when the primary current energization is interrupted (normally, the primary current value when the primary current energization is interrupted). However, since the primary current at the time of the interruption of the primary current is greatly fluctuated, the current may not be detected accurately. Therefore, considering that the primary current after the start of energization increases at a substantially constant rate, first,
By detecting the primary current at a predetermined time before the primary current energization cutoff time, adding the current value expected to increase during the predetermined time thereafter, and predicting the current value at the time of the primary current energization cutoff, It is preferable to detect a primary current at the time of current supply interruption.

However, the rate of increase of the primary current after the start of energization depends on the characteristics of the ignition coil (winding resistance, reactance, etc.) as well as the power supply voltage. When the power supply voltage is high, the primary current increases. And primary current rises slowly when the power supply voltage is low. For this reason, an error may occur in the value of the predicted primary current due to the fluctuation of the power supply voltage.

Therefore, in order to control the primary current supply time based on the detected primary current and the power supply voltage, the primary current detection means may supply the primary current with the OFF control of the switching means. The primary current value at which the primary current is interrupted is detected a predetermined time before the primary current energization interruption timing, and the energization time control means corrects the primary current value based on the power supply voltage value detected by the power supply voltage detection means to correct the primary current value. Is preferably calculated.

That is, the rise rate of the primary current can be accurately grasped by using the power supply voltage value, and the primary current detected at a predetermined time before the primary current energization cut-off time is calculated from the primary current at the primary current energization cut-off. It is possible to accurately predict the current. Therefore, according to the ignition device for an internal combustion engine according to claim 5, it is possible to accurately predict the maximum value of the primary current while suppressing the detection error of the primary current,
It is possible to precisely and constantly control the magnetic flux energy accumulated in the ignition coil.

By the way, the above-mentioned ignition control means comprises a CP
It is generally realized by internal processing of an electronic control unit for controlling an internal combustion engine, which is composed of a microcomputer (hereinafter, also referred to as a microcomputer) having U, RAM, ROM, input / output ports and the like as main components. In recent electronic control devices, not only ignition control but also many other parameters such as a fuel injection amount, an air-fuel ratio, and a fuel injection timing, based on an input from a sensor (for example, a crank angle sensor) provided in each part of the internal combustion engine. The control processing is being executed, and the load of the internal processing in the electronic control unit is considerably high. For this reason, when the above-described power supply start timing delay means is realized by internal processing in the electronic control device, the processing load increases and exceeds the allowable range of the device itself, and each control process can be executed normally. There is a risk of disappearing.

Therefore, it is preferable that the power supply time control means is provided in a form independent of the ignition control means for outputting an ignition command signal. In other words, by providing a control device for executing the processing as the energization time control means in a form independent of the ignition control means (generally, an electronic control device for controlling the internal combustion engine), the ignition control means There is no need to execute the processing as the time control means, and the processing load on the ignition control means (electronic control device) does not increase. The control device can be configured using a microcomputer or an electric circuit including a resistance element, a capacitance element, and the like.

On the other hand, if a microcomputer having a high processing capability is used as the ignition control means (electronic control device) for outputting the ignition command signal, the energization time control means can be processed by one microcomputer together with other control processing. Become. However, since the microcomputer constituting the ignition control means (electronic control device) selects one having a necessary and sufficient capacity and the number of ports (the number of terminals) at the time of design, when the control function is added to the existing one, Requires not only the addition of software processing but also the design of the microcomputer itself from the basic part, including the capacity and the number of ports. In this case, a large development cost will be spent.

Therefore, if the ignition device for an internal combustion engine is configured so that the power supply time control means is executed by a control device independent of the ignition control means, the existing internal combustion engine that is currently being produced is provided. By adding a control device as an energization time control unit to the engine ignition device, an ignition device for an internal combustion engine having a function of controlling the primary current energization time can be realized.

Therefore, the present ignition device for an internal combustion engine can be realized inexpensively and simply without changing the design of the existing ignition control means (electronic control device). Also,
Because most of the components of the ignition device can be used,
In particular, when the configuration of the ignition device for an internal combustion engine is applied to a mass-produced internal combustion engine, the cost that can be saved as a whole of the production amount is larger than when applied to a small-production internal combustion engine. The effect is further enhanced.

The microcomputer for executing the processing as the power-on time control means has an arithmetic capacity of 4 to 8 [bi
t], an A / D converter of at least about 8 [bit] and 2
This function can be realized by a microcomputer having one input port and one output port. Since the microcomputer of such a level is inexpensive as compared with a large-capacity transistor, the internal combustion engine ignition device can be realized at low cost.

Incidentally, when noise is generated for some reason when detecting the primary current, the primary current may be erroneously detected due to the influence of the noise. May not be controlled accurately. Therefore, in the internal combustion engine ignition device described above (claims 1 to 6), as described in claim 7, the primary current detecting means detects noise generated when detecting a primary current flowing through the primary winding. It is preferable to provide a noise removing means for preventing intrusion.

By providing the noise removing means in this way, it is possible to prevent erroneous detection of the primary current due to the influence of noise, and to accurately detect the primary current. As a result, the primary current supply time can be accurately controlled, and the magnetic flux energy accumulated in the ignition coil can be controlled within a predetermined range in which the internal combustion engine can operate normally.

When setting the primary current energizing time, the energizing time control means may control the primary current energizing time in a stepwise manner. That is, in setting the primary current energizing time based on the detected maximum value of the primary current, for example, a predetermined correction value (fixed value) is set for the finally set current primary current energizing time. By adding or subtracting, the primary current conduction time is set stepwise.

As described above, when the primary current supply time is set with the correction value as a fixed value, the processing for calculating the correction value is different from the case where the correction amount according to the primary current detected for each combustion cycle is calculated. Can be reduced. In addition, in the two consecutive combustion cycles, the primary current at the time of the interruption of the primary current energization does not greatly change. Therefore, the primary current energization time is set for each combustion cycle using a relatively small correction value (fixed value). Is set in stages, it is also possible to make the magnetic flux energy accumulated in the ignition coil close to the optimum value.

Therefore, according to the ignition device for an internal combustion engine according to the eighth aspect, since the processing for calculating the correction value can be reduced, the processing load for setting the primary current supply time can be reduced. Further, it is possible to suppress an increase in processing load when a function of setting a primary current conduction time based on the maximum value of the primary current is added to a conventionally used internal combustion engine ignition device.

The ignition device for an internal combustion engine described above is
As described in the ninth aspect, the present invention is more effective when used in a gas engine using gaseous fuel as fuel. That is, gaseous fuel is liquid fuel (for example, gasoline)
In order to reliably ignite fuel in a gas engine, it is necessary to apply a relatively high ignition voltage to a spark plug compared to a gasoline engine to generate spark discharge in comparison with a gasoline engine because of its high insulation properties. There is. Therefore, the maximum secondary voltage (ignition high voltage) generation capability as an ignition coil for a gas engine using gaseous fuel needs to be set higher than that for a gasoline engine (for example,
If the maximum secondary voltage as an ignition coil for a gasoline engine is 30 [kV] or more, that for a gas engine is set to 40 [kV] or more.) Therefore, in a gas engine, the current value when energizing / cutting off the primary winding is set to be relatively large so that the fuel can be ignited reliably.

In such a gas engine, since the maximum secondary voltage is high, the electrodes of the spark plug tend to be worn out with the lapse of time, and spark discharge occurs when the spark gap becomes large due to electrode wear. The maximum secondary voltage required for this further increases.

For this reason, in such a gas engine, for example, when the maximum value of the primary current flowing through the primary winding fluctuates in a direction to decrease due to the variation between the individual ignition coils, the magnetic flux energy accumulated in the ignition coil Shortage and the possibility of a misfire increases.

For this reason, a gas engine is provided with the ignition device for an internal combustion engine according to the present invention, and the primary current energizing time is controlled so that the maximum value of the primary current is constant. The magnetic flux energy required for generation can be stored in the ignition coil, and the occurrence of misfire can be suppressed.

Therefore, the present invention provides a gas engine using a gaseous fuel.
If the ignition device for an internal combustion engine according to any of the above is applied,
The effect of preventing the occurrence of misfire due to variation between ignition coils can be further exhibited.

Among the gas engines, an ignition device for an internal combustion engine provided in a stationary gas engine includes, for example,
An AC voltage (for example, 100 [V] or 200 [V]) supplied from a power company such as a commercial power supply is supplied to a transformer,
Convert to DC voltage using rectifier and smoothing circuit, etc.
In some cases, a DC current obtained in this way is used to generate an energizing current to the primary winding to generate a high ignition voltage.

In the ignition device for an internal combustion engine of a stationary gas engine using such a commercial power supply, the voltage applied to the primary winding tends to fluctuate, and a misfire due to a decrease in the primary current tends to occur. That is, the power demand for the power supplied from the power company changes every season, and the change in the power demand causes the AC voltage value of the commercial power supply to change every season (for example, summer and winter). It shows the value. Note that the AC voltage value of the commercial power supply fluctuates within a predetermined allowable range.

Thus, although within the allowable range,
As the AC voltage of the commercial power supplied from the power company fluctuates, the DC voltage after conversion also shows a different value for each season, and in the stationary gas engine, the primary coil is energized. The power supply voltage for generating the current changes every season.

Therefore, by applying the internal combustion engine ignition device to a stationary gas engine and controlling the primary current supply time, magnetic flux energy capable of generating spark discharge is accumulated in the ignition coil. The effect of suppressing the occurrence of misfire can be further exhibited.

[0050]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 is a configuration diagram showing a schematic configuration of an ignition device for an internal combustion engine according to an embodiment. The ignition device for an internal combustion engine according to the present embodiment is an ignition device for an internal combustion engine provided in a stationary gas engine using gaseous fuel as fuel.

As shown in FIG. 1, an ignition device 1 for an internal combustion engine according to the embodiment converts a AC voltage of a commercial power supply and outputs a DC voltage for discharge (for example, a power supply voltage of 12 [V]). 11, an ignition coil 13 having a primary winding L1 and a secondary winding L2, and an np connected in series with the primary winding L1.
Main control transistor 15 composed of an n-type transistor
A spark plug 17 that forms a closed loop with the secondary winding L2 and is provided in a cylinder of the internal combustion engine;
In order to generate a spark discharge between the electrodes 17a and 17b of the internal combustion engine 7, an electronic control unit for controlling the internal combustion engine (hereinafter, referred to as an output) that outputs an ignition command signal IG corresponding to the operating state of the internal combustion engine to the main control transistor 15 ECU 31).

Further, the ignition device 1 for an internal combustion engine transforms a power supply voltage output from the DC power supply device 11 with a microcomputer (hereinafter also referred to as a microcomputer) 21 for delaying the start of energization of the primary winding. A voltage conversion circuit 23 for generating a drive voltage (for example, 5 [V]) for driving the microcomputer 21 and a main control transistor 15 for maintaining the main control transistor 15 in an off state based on the energization start delay signal Sb from the microcomputer 21. An energization delay transistor 25 composed of an npn transistor, a power supply voltage detection circuit 27 for detecting a power supply voltage supplied from the DC power supply 11 to the primary winding L1, and a primary current i1 flowing through the primary winding L1. And a primary current detection circuit 33 for performing the operation.

Of these, the main control transistor 15
Is a switching element composed of the above-described semiconductor element for switching between energization (on state) and non-energization (off state) of the primary winding L1 of the ignition coil 13. The ignition device 1 for an internal combustion engine of the present embodiment is a full transistor. Type ignition device.

The DC power supply 11 includes a transformer, a rectifier, a smoothing circuit, etc., and converts an AC voltage (for example, AC 100 [V]) from a commercial power supply (not shown).
By rectifying and smoothing, it is converted to a DC voltage (for example, a power supply voltage of 12 [V]).

The ECU 31 is provided for comprehensively controlling the spark discharge timing, fuel injection amount, engine speed, etc. of the internal combustion engine based on the operating state of the internal combustion engine. It is mainly composed of a microcomputer having a ROM and an input / output unit as main components.

Although components other than the ECU 31 are provided for each cylinder in an internal combustion engine having a plurality of cylinders, only one cylinder is shown in FIG. I have. One end of the primary winding L1 of the ignition coil 13 is connected to the positive electrode of the DC power supply 11, and the other end is connected to the collector of the main control transistor 15. One end of the secondary winding L2 is connected to one end of the primary winding L1 connected to the positive electrode of the DC power supply 11 via the rectifying element D1, and the other end is connected to the center electrode 17a of the ignition plug 17. Connected (electrical connection). Further, the ground electrode 17b of the ignition plug 17 is connected (grounded) to the ground having the same potential as the negative electrode of the DC power supply 11, and the base of the main control transistor 15 is connected to the ground through a resistor R3.
The output terminal of the ignition command signal IG of the CU 31 is connected, and the emitter of the main control transistor 15 is connected (grounded) to the ground of the same potential as the negative electrode of the DC power supply 11 via the primary current detection circuit 33. .

For this reason, when a post-machining ignition command signal Sa to be described later input to the base of the main control transistor 15 is at a low level (generally a ground potential), no base current flows through the main control transistor 15. The main control transistor 15 is turned off, and no current flows through the primary winding L1 through the main control transistor 15. When the post-machining ignition command signal Sa is at a high level (for example, a supply voltage of 5 [V] from a constant voltage power supply), the main control transistor 15 is turned on, and the main control transistor 15 is turned on from the positive electrode side of the DC power supply 11. Primary winding L of ignition coil 13
1, main control transistor 15, primary current detection circuit 33
Primary winding L1 passing through the DC power supply 11 to the negative electrode side
Is formed, and a primary current i1 flows through the primary winding L1.

Here, the main control transistor 15
The ON state indicates a state where the collector and the emitter of the main control transistor 15 are conductive (short-circuited state), and the OFF state indicates a state where the collector and the emitter of the main control transistor 15 are not conductive. (Open state).

Therefore, when the post-machining ignition command signal Sa switches to low level while the post-machining ignition command signal Sa is at the high level and the primary current i1 is flowing through the primary winding L1, the main control transistor 15 turns off, and the supply of the primary current i1 to the primary winding L1 is stopped (cut off). Then, the magnetic flux density of the ignition coil 13 suddenly changes, and a high voltage for ignition is generated in the secondary winding L2. This high voltage for ignition is applied to the ignition plug 17, so that the electrode 17a of the ignition plug 17 Spark discharge occurs between -17b.

The ignition coil 13 applies a negative high ignition voltage lower than the ground potential to the center electrode 17a of the ignition plug 17 by interrupting the primary current i1 in the primary winding L1 by the main control transistor 15. The secondary current i2 flowing through the secondary winding L2 due to the spark discharge at the ignition plug 17 is generated by the ignition plug 1
7 through the secondary winding L2 from the center electrode 17a to the primary winding L1 side. The secondary winding L2 and the primary winding L1
A rectifying element D1 composed of a diode or the like is provided at a connection portion between the secondary winding L1 and the secondary winding L2 to allow a current to flow from the secondary winding L2 to the primary winding L1 side and to prevent a current from flowing in the reverse direction. ing. In the present embodiment, a diode whose anode is connected to the secondary winding L2 and whose cathode is connected to the primary winding L1 is provided as the rectifier element D1, and the operation of the rectifier element D1 causes the main control transistor 15 to turn on. The current is prevented from flowing through the secondary winding L2 (at the start of energization of the primary winding L1).

The voltage conversion circuit 23 has a voltage reference terminal connected to ground (ground), an input terminal connected to the positive electrode of the DC power supply 11, an output terminal connected to the microcomputer 21, and an input terminal connected to the microcomputer 21. The input voltage is transformed and output from the output terminal. That is, the DC power supply 11
The microcomputer 21 transforms a power supply voltage (for example, 12 [V]) output from the microcomputer 21 and supplies a driving voltage (for example, 5 [V]) to the microcomputer 21. The voltage conversion circuit 23 can be configured using, for example, a so-called three-terminal regulator.

The power supply voltage detecting circuit 27 includes a resistor R1
And the resistor R2 are connected in series. In the power supply voltage detecting circuit 27, the end on the side of the resistor R1 is connected to the positive electrode of the DC power supply device 11, and the end on the side of the resistor R2 is connected to the DC power supply. It is connected to the negative electrode of the device 11 (in other words, the ground). Further, a connection point between the resistors R1 and R2 is connected to the microcomputer 21, and the divided voltage Vs of the power supply voltage by the resistors R1 and R2 is input to the microcomputer 21.

At this time, the resistance value of each of the resistors R 1 and R 2 is determined based on the variation range of the divided voltage Vs corresponding to the variation range of the power supply voltage value output from the DC power supply 11. It is determined to be within the allowable range. Then, the divided voltage value Vs varies according to the voltage value of the power supply voltage output from the DC power supply device 11, and the microcomputer 21 determines that the voltage value falls within a range from a lower limit value to an upper limit value (for example, 0 to 5 [V]), the power supply voltage value can be detected by inputting the divided voltage value Vs.

Next, the energization delay transistor 25 has a collector connected to the base of the main control transistor 15, an emitter connected to ground (grounded), and a base for outputting an energization start delay signal Sb in the microcomputer 21. Connected to terminal. When the energization start delay signal Sb input to the base of the energization delay transistor 25 is at a low level (generally, ground potential), no base current flows through the energization delay transistor 25 and the energization delay transistor 25 It turns off. At this time,
The state of the post-machining ignition command signal Sa input to the base of the main control transistor 15 is determined based on the state of the ignition command signal IG output by the ECU 31. That is, when the energization delay transistor 25 is in the off state,
The main control transistor 15 is controlled to an on state or an off state by a command from the ECU 31.

When the energization start delay signal Sb is at a high level (for example, a supply voltage of 5 [V] from a constant voltage power supply), a base current flows through the energization delay transistor 25 and the energization delay transistor 25 Is turned on.
At this time, the post-processing ignition command signal Sa is forcibly maintained at a low level, and the post-processing ignition command signal Sa is output based on the state of the ignition command signal IG output by the ECU 31.
Is not determined. That is, when the energization delay transistor 25 is in the ON state, the main control transistor 15 operates regardless of a command from the ECU 31.
The off state will be maintained.

Next, the primary current detection circuit 33 has one end connected to the emitter of the main control transistor 15 and the other end connected to the ground (ground), and removes the influence of noise and the like. , And outputs the voltage Vr across the detection resistor 35 to the microcomputer 21 through the filter circuit 37 as a primary current detection signal S1.

The filter circuit 37 has one end connected to the connection point between the detection resistor 35 and the main control transistor 15, and the other end connected to the input terminal of the primary current detection signal S 1 in the microcomputer 21. R4 and microcomputer 21
A capacitor C1 provided between the end of a resistor R4 connected to the ground and a ground; a diode D2 provided between a connection point between the resistor R4 and the capacitor C1 and an output terminal of the voltage conversion circuit 23; And D3 connected in parallel to the capacitor C1.

The diode D2 has a cathode connected to the output terminal of the voltage conversion circuit 23, and an anode connected to the resistor R2.
4 and the capacitor C1. The diode D3 has a cathode connected to a connection point between the resistor R4 and the capacitor C1, and an anode connected (grounded) to the same potential as the negative electrode of the DC power supply device 11.

At this time, in the filter circuit 37, the resistance R
4 and the capacitor C1 function as a low-pass filter to suppress the influence of noise on the primary current detection signal S1, and the diodes D2 and D3 drive the microcomputer 21 to drive the potential of the primary current detection signal S1. The voltage is limited to the voltage (5 [V]) or less to prevent the microcomputer 21 from being destroyed by a high-potential signal output.

Incidentally, the high-level potential Vh of the ignition command signal IG output by the ECU 31, the voltage Vr across the detection resistor 35, and the base-emitter voltage Vbe of the main control transistor 15 have the following relationship: Vh = Vbe + Vr. There is. From this, the voltage V across the detection resistor 35 is obtained.
r increases, the main control transistor 15
, The base-emitter voltage Vbe of the main control transistor 1
5, the main control transistor 1
5 cannot be driven.

Therefore, the voltage Vr across the detection resistor 35 is obtained.
It is desirable that the resistance value of the detection resistor 35 be set to a small value so as not to hinder the driving of the main control transistor 15. Although the maximum value of the primary current naturally changes depending on the number of turns of the primary winding, it is usually 4 [A] to 8 [A].
(Power supply voltage 12 [V]).
5 so that the maximum power W (= I ² R) consumed at 5 becomes a reasonable cost (power consumption).
In order to make the allowable power of 3 [W] to 5 [W], the resistance value of the detection resistor 35 is, for example, 0.1 [Ω] to 0.3 [Ω].
[Ω] should be set.

Next, the microcomputer 21 includes a voltage conversion circuit 23
Are driven by supplying a driving voltage from the power supply voltage detection circuit 27, the divided voltage value Vs is input from the power supply voltage detection circuit 27, the primary current detection signal S1 is input from the primary current detection circuit 33, and E
The ignition command signal IG is input from the CU 31. Then, the microcomputer 21 sets an energization start delay time based on the divided voltage value Vs and the primary current detection signal S1, and synchronizes with the state change of the ignition command signal IG from the low level to the high level. Is output at a high level. The details of the processing in the microcomputer 21 will be described later.

Next, FIG. 2 shows the ignition command signal IG, the post-machining ignition command signal Sa,
Energization start delay signal Sb, primary current i1, spark plug 17
3 shows a time chart showing each state of the potential Vp of the center electrode 17a. First, at time t1 in FIG. 2, when the ignition command signal IG switches from low to high level, the energization start delay signal Sb switches from low to high level in synchronization with this. Thereby, the main control transistor 15
Is maintained at a low level, so that the primary current i1 does not flow through the primary winding L1. After that, the divided value Vs of the power supply voltage detected by the power supply voltage detection circuit 27 and the primary current detection circuit 33
At time t2 when the energization start delay time set based on the primary current detection signal S1 detected at the time t2 has elapsed, the energization start delay signal Sb switches to a low level and the post-machining ignition command signal Sa changes from low to high. Switch to level,
The main control transistor 15 is turned on, and the primary current i1 starts to flow.

At time t3, which is the ignition timing (primary current energization cutoff timing) after a lapse of further time, the ignition command signal IG switches from high to low level, and the main control transistor 15 is turned off. As a result, the supply of the primary current i1 to the primary winding L1 is interrupted, and the ignition plug 1
A high voltage for ignition of negative polarity is applied to the center electrode 17a of the No. 7 and its potential Vp drops sharply, and spark discharge occurs between the electrodes 17a and 17b of the spark plug 17. Then, the magnetic flux energy accumulated in the ignition coil 13 is consumed for generation of spark discharge, and the spark discharge ends naturally at time t4 when the magnetic flux energy is consumed until the spark discharge cannot be maintained. I do.

As described above, even when the ignition command signal IG is at the high level, the primary current i1 does not flow when the energization start delay signal Sb is at the high level. Therefore, the primary current i1 is determined by the energization start delay signal Sb. It can be seen that the power supply start timing can be delayed. As a result, the primary current energizing time in the internal combustion engine ignition device is controlled by the ECU 31
It can be seen that the time (time t2 to time t3) is shorter than the primary current energization time (time t1 to time t3) set by the above.

Next, the ignition control process executed by the ECU 31 will be described. As described above, the ECU 31 calculates the spark discharge timing of the internal combustion engine, the fuel injection amount,
This is for comprehensively controlling the idling speed and the like. In addition to the ignition control process described below, the intake air amount (intake pipe pressure), rotation speed, throttle opening, and throttle opening of the internal combustion engine are controlled.
An operation state detection process for detecting an operation state of each part of the engine such as a cooling water temperature and an intake air temperature, a fuel control process for supplying fuel into the intake pipe at a fuel injection timing, and the like are performed.

In the ignition control process, after the start of the internal combustion engine, the internal combustion engine performs intake, compression, combustion, and exhaust based on a signal from a crank angle sensor for detecting a rotation angle (crank angle) of the internal combustion engine, for example. 1 in one combustion cycle
Executed at the rate of times. When the ignition control process is started, first, the operation state of the internal combustion engine detected in the operation state detection process executed separately is read, and a map or a calculation formula set in advance based on the read operation state is read. In addition, the ignition timing suitable for the operating state of the internal combustion engine is set, and the ignition timing in the current combustion cycle is set.
Note that the map or calculation formula for setting the ignition timing is such that, for example, the operation state such as the engine rotation speed or the engine load of the internal combustion engine is used as a parameter to set the ignition timing according to the operation state of the internal combustion engine. Constitute.

Subsequently, the ignition command signal IG is changed to a high level at a time earlier than the ignition timing by a predetermined time with reference to the set ignition timing. The predetermined time here is a primary current energizing time before spark discharge,
Sufficient magnetic flux energy can be accumulated in the ignition coil during the primary current supply time in order to generate a spark discharge that can reliably ignite fuel even under operating conditions with poor ignitability, that is, to generate a high ignition high voltage. The time (fixed value) is set in advance. As a result, the spark discharge duration from the occurrence of the spark discharge to the end thereof becomes sufficiently long,
For example, even in an operation state having poor ignitability such as at a low rotation speed and a low load, the fuel can be surely burned by assisting the growth of the flame kernel.

When the ignition start signal IG is changed to a high level and the energization start delay signal Sb output from the microcomputer 21 becomes a high level, the main control transistor 15 is maintained in an off state. You. Thereafter, when the energization start delay signal Sb changes to a low level, the main control transistor 15 is turned on, and the primary winding L
1 is started.

In the ignition control process, the ignition command signal IG is changed to low level at the ignition timing (primary current energization cutoff time) after the primary current energization time has elapsed since the ignition command signal IG was changed to high level. Thus, the main control transistor 15 is turned off. Thus, the primary current i1
Is rapidly cut off, and a high voltage for ignition, which is an induced electromotive force, is generated in the secondary winding L2, and spark discharge is generated in the spark plug 17.

FIG. 3 shows the waveform of the primary current i1 when the power supply voltage is different. In FIG. 3, a solid line indicates a waveform when the power supply voltage is low, and a broken line indicates a waveform when the power supply voltage is high. Then, time t11 in FIG. 3 is an energization start time when the power supply voltage is low, and time t12 is an energization start time when the power supply voltage is high, and corresponds to time t2 in FIG. The time t14 in FIG. 3 is the ignition timing,
This corresponds to time t3 in FIG.

As can be seen from FIG. 3, when the power supply voltage is different, the waveform of the primary current i1 (current increase rate) with the passage of time after the start of energization is different, and when the power supply voltage is low, the primary current increases. It can be seen that the ratio (increase rate) is small, and the increase rate (increase rate) of the primary current is large when the power supply voltage is high.

Incidentally, the primary current i1 is detected by the primary current detection circuit 33, and the ignition timing (when the primary current is cut off; time t3 in FIG. 2, time t14 in FIG. 3).
In order to perform control for keeping the maximum value of the primary current i1 constant in the above, it is desirable to detect the primary current i1 at the primary current energization cutoff time. However, it is difficult to accurately detect the primary current i1 when the primary current is cut off because the primary current i1 greatly changes instantaneously. For this reason, the ignition device for an internal combustion engine detects the primary current i1 at the time of the interruption of the primary current by predicting an increase over time based on the primary current i1 detected a predetermined time before the interruption of the primary current. Take the method.

However, the current value of the primary current i1 at time t13 shown in FIG. 3 is equal when the power supply voltage is low and when the power supply voltage is high, but when the primary current is cut off (time t14 in FIG. 3). Have different values for the primary current i1. In other words, even if the value of the primary current i1 is equal to or less than a predetermined time before the primary current is cut off, the primary current i1 at the time of the primary current cutoff may be different. This occurs because the power supply voltage is different. When predicting the primary current i1 at the time of the interruption of the primary current supply, the prediction is made in consideration of the magnitude of the power supply voltage. It can be predicted. Note that the primary current i
The process of predicting 1 is executed by the microcomputer 21 and will be described later.

Next, the energization time control process executed by the microcomputer 21 will be described with reference to the flowchart shown in FIG. Note that the energization time control process is started and started when the internal combustion engine is started. Then, when the energization time control process is started, first, in S110,
The counter N is reset by substituting 0 into the counter N. The counter N is a counter used to determine the timing for detecting the power supply voltage.

Next, in S120, the energization start delay time T
Initial values are set to s and variables A, B, C, D, E, and F.
At this time, it is desirable to set the energization start delay time Ts to a value suitable for the operating state immediately after the start of the internal combustion engine, and the temperature of the internal combustion engine is low immediately after the start of the internal combustion engine, and the ignitability to fuel is poor. Because of the operating state, a value that increases the primary current energization time or the energization start delay time T
An initial value is set so that s becomes 0 [sec]. Also,
The variables A, B, C, D, E, and F are variables used when calculating the average value of the detected power supply voltage and the primary current i1, and all the variables are set to 0 in S120.

At S130, it is determined whether or not a state change in the rising direction (low level to high level) of the ignition command signal IG output from the ECU 31 has occurred. If the determination is affirmative, the process proceeds to S140. If a negative determination is made, the same step is repeatedly executed to wait until the ignition command signal IG changes state. That is, S13
At 0, it is determined whether or not it is time to start energizing the primary winding L1 by the ignition control process performed by the ECU 31.

Then, if a positive determination is made in S130, S1
In S140, the energization start delay signal Sb is set to the high level state, and output to the energization delay transistor 25 is started (time t1 in FIG. 2). As a result, the post-machining ignition command signal Sa input to the base of the main control transistor 15 is forcibly maintained at the low level.

Next, in S150, a timer count for measuring the elapsed time from the occurrence of a change in the state of the ignition command signal IG (after an affirmative determination in S130) is started. In subsequent S160, it is determined whether or not the timer value started counting in S150 is equal to or longer than the energization start delay time Ts. If the determination is affirmative, the process proceeds to S170, and if the determination is negative, the same steps are repeated. By executing, the process waits until the timer value becomes equal to or longer than the energization start delay time Ts. That is, in S160, the ignition command signal IG
It is determined whether or not the energization start delay time Ts has elapsed after the occurrence of the state change (after the affirmative determination in S130).

Then, if an affirmative determination is made in S160, S1
In S170, the output of the high-level energization start delay signal Sb is terminated (at time t in FIG. 2).
2). As a result, the energization delay transistor 25 is turned off, the post-machining ignition command signal Sa is input to the base of the main control transistor 15, the main control transistor 15 is turned on, and the primary current i1 flows through the primary winding L1. Begins to flow.

After the process of S170 is executed and the process proceeds to S180, the ECU 3 sets the detection time of the primary current i1 based on the detected power supply voltage in order to set the detection time of the primary current i1.
A primary current detection time Tm is set from the state change timing of the ignition command signal IG due to 1 (the timing at which the determination is affirmative in S130) to the timing at which the primary current i1 is detected. As described above, the primary current supply time by the ECU 31, that is, the high level output time of the ignition command signal IG is a fixed value, and the primary current supply cutoff time (in other words, the primary time) before the primary current supply cutoff time (in other words, the ignition timing). The timing for detecting the current i1 can be determined based on the timing determined to be affirmative in S130. Specifically, the primary current detection time Tm is set so that the time when the primary current detection time Tm has elapsed from the primary current supply time by the ECU 31 is the detection time of the primary current i1 a predetermined time before the primary current supply cutoff time. Set. When the power supply voltage is not detected immediately after the start of the internal combustion engine (immediately after the start of the energization time control process), the primary current detection time Tm according to the rated voltage is set.

At S190, it is determined whether or not the timer value counted at S150 is equal to or longer than the primary current detection time Tm set at S180. If the determination is affirmative, the process proceeds to S200, and the determination is negative. Then, by repeatedly executing the same step, the apparatus stands by until the timer value becomes equal to or longer than the primary current detection time Tm. That is, S190
Then, after the state change of the ignition command signal IG from low to high occurs (after an affirmative determination is made in S130), it is determined whether or not the primary current detection time Tm has elapsed. The detection time is determined.

Then, if a positive determination is made in S190, S2
Then, in S200, a primary current detection routine is executed. Here, the processing content of the primary current detection routine will be described below with reference to the flowchart shown in FIG. As shown in FIG. 5, first, when the primary current detection routine is started, in S410, the primary current detection circuit 33 is started.
Current detection signal S1 (specifically, the potential V
r) and the resistance value of the detection resistor 35, the primary current i1
Is detected (sampled).

In the next S420, the value of the variable E is substituted for the variable D. In the following S430, the value of the variable F is substituted for the variable E. In the next S440, the value of the primary current i1 detected in S410 is substituted. Substitute in variable F. In the following S450,
It is determined whether or not the value of the variable D is 0. If the determination is affirmative, the process proceeds to S460. If the determination is negative, the primary current detection routine is terminated, and the energization time control is performed again. Move on to processing. If the primary current i1 is detected three or more times after the operation of the internal combustion engine is started, the value of the detected primary current i1 is substituted for the variable D, and the variable D becomes a value other than 0. That is, in S450, it is determined whether or not the primary current i1 has been detected at least three times since the operation of the internal combustion engine was started. If the primary current i1 has been detected three or more times, the energization start delay time Ts is set. In order to do
The process moves to 460.

Then, if an affirmative determination is made in S450, S4
In S460, the average value of the variables D, E, and F is calculated, and the average primary current value Iav is calculated. The following S
In 470, the primary current average value Iav calculated in S460 is calculated.
, A primary current i1 when the primary current is cut off is predicted, and a correction value for correcting the predicted value is calculated based on the power supply voltage. As described above with reference to FIG. 3, since the increase rate of the primary current i1 changes according to the magnitude of the power supply voltage, in S470, a preset map using the power supply voltage value as a parameter is used. Alternatively, an optimal correction value is calculated according to the power supply voltage using a calculation formula. That is, a correction value is calculated such that the predicted value is higher as the power supply voltage is higher, and a correction value is calculated as the predicted value is lower as the power supply voltage is lower.

In the next S480, the value corrected by the correction value calculated in S470 is used as the primary current average correction value Iavc.
Set as In subsequent S490, it is determined whether or not the primary current average correction value Iavc set in S480 is equal to or less than a preset primary current target value It. If the determination is affirmative, the process proceeds to S500, and the determination is negative. Then S5
Move to 10. Here, the primary current target value It can induce a minimum high voltage for ignition required for generating spark discharge with the spark plug to the ignition coil (secondary winding) under all operating conditions of the internal combustion engine. A target value larger than the primary current value is set in advance.

Then, if an affirmative determination is made in S490, S5
In S500, the energization start delay time Ts is corrected to a value smaller by the time correction value α. That is, S49
An affirmative determination of 0 indicates that the energy stored in the ignition coil is slightly insufficient, and the energization start delay time Ts
Is reduced, the primary current energization time in the next combustion cycle is lengthened, and the stored energy is increased to approach an appropriate value. The time correction value α is
It is a predetermined fixed value, and a value suitable for correcting the power supply start delay time Ts for each combustion cycle is set.

On the other hand, if a negative determination is made in S490, S51 is reached.
In S510, the power supply start delay time Ts is corrected to a value larger by the time correction value α. That is, S490
A negative determination in indicates that the energy stored in the ignition coil is excessive, and the energization start delay time Ts is increased to shorten the primary current energization time in the next combustion cycle, thereby reducing the stored energy. Decrease it to get closer to the appropriate value.

After the processing in S500 or S510 is performed, the flow shifts to S520, where it is determined whether or not the finally set energization start delay time Ts is within a predetermined allowable range. If the determination is affirmative, the primary current detection routine ends, and if the determination is negative, the process proceeds to S530. Here, the allowable range in S520 is set to a range of the power supply start delay time Ts corresponding to the range of the primary current power supply time in which spark discharge can occur at the spark plug. That is, the ranges determined by the respective values obtained by subtracting the maximum value and the minimum value of the primary current energization time during which spark discharge can occur from the primary current energization time by the ECU 31 are set as the energization start delay time Ts. This is a possible tolerance.

If a negative determination is made in S520, the process proceeds to S53.
Then, in S530, the energization start delay time Ts is corrected by setting a value within the allowable range to the energization start delay time Ts deviating from the allowable range. Specifically, when the energization start delay time Ts falls below the lower limit of the allowable range,
When the lower limit of the allowable range is set to the energization start delay time Ts, and when the upper limit of the allowable range is exceeded, the upper limit of the allowable range is set to the energization start delay time Ts, thereby correcting the energization start delay time Ts. I do.

Then, when the processing in S530 is completed or when an affirmative determination is made in S520, the primary current detection routine is terminated, and the process returns to the energization time control processing.
As described above, the primary current detection routine performs the primary current average value Iav that is the average value (moving average value) of the past three times of the primary current i1 detected a predetermined time before the primary current energization cutoff time.
The primary current average correction value Iavc is set by predicting the primary current i1 when the primary current is cut off from the primary current average value Iav, and correcting the primary current i1 with a correction value calculated based on the power supply voltage. Then, the primary current average correction value I
Based on the result of comparing avc with the primary current target value It, the energization start delay time Ts is set by adding or subtracting the time correction value α to or from the energization start delay time Ts.

Thereafter, the process returns to the energization time control process again, and when the process of S200 ends, the timer count started in S150 is stopped in S210, and 0 is substituted for the timer value in S220. , Reset the timer. In the next S230, by adding 1 to the counter N (incrementing the counter N),
The counter N is being updated.

In the following S240, it is determined whether or not the counter N is 5 or more.
The process proceeds to S130 if a negative determination is made. In this energization time control process, the power supply voltage is detected once every five combustion cycles, and in S240, it is determined whether or not the combustion cycle (timing) for detecting the power supply voltage. I have.

If a negative determination is made in S240, S1 is reached.
The program proceeds to S130, in which the energization start timing in the next combustion cycle is detected. After that, until the counter N becomes 5 or more, that is, until the affirmative determination is made in S240, the processes from S130 to S240 are repeatedly executed to use the energization start delay time Ts corrected based on the primary current i1. Thus, a delay process of the power supply start timing in each combustion cycle is performed.

In this way, the processing from S130 to S240 is repeated, and when the counter N becomes 5 or more, an affirmative determination is made in S240 and the process proceeds to S250. Then, in S250, the power supply voltage detection routine is started.
Here, the processing content of the power supply voltage detection routine will be described below with reference to the flowchart shown in FIG.

First, when the power supply voltage detection routine is started, in step S710, the divided voltage value Vs input from the power supply voltage detection circuit 27 is detected (sampled) as the power supply voltage Vs1, and in step S720, the power supply voltage Vs1 is detected. Assign to variable A. In the next S730, the divided voltage value Vs input from the power supply voltage detection circuit 27 is detected (sampled) as the power supply voltage Vs2, and in the next S740, the power supply voltage Vs2 is substituted into a variable B.

Further, in S750, the power supply voltage detecting circuit 2
7 is detected (sampled) as the power supply voltage Vs3, and the power supply voltage Vs is detected in next S760.
3 is assigned to a variable C. That is, the power supply voltage detection circuit 27
Is detected (sampled) three times. The reason why the partial pressure value Vs is performed three times is to improve the detection accuracy.

Then, in the next S770, the variables A, B,
The average value of C is calculated, and the calculated average value is multiplied by the ratio of the power supply voltage to the divided voltage value Vs determined by the respective resistance values of the resistors R1 and R2, thereby obtaining S710 and S73.
0, the respective power supply voltage values detected in S750 are calculated.

At S780, the power supply start delay time is calculated based on the power supply voltage value calculated at S770, using a preset map or calculation formula using the power supply voltage value as a parameter. The map or the calculation formula used in the calculation process is configured such that the power supply start delay time increases as the power supply voltage value increases, and the power supply start delay time decreases as the power supply voltage value decreases. I have.

In the next step S790, the power supply start delay time Ts is updated by substituting the power supply start delay time calculated in S780 for the power supply start delay time Ts used in the power supply time control processing. In S800, the counter N is reset by substituting 0 into the counter N used in the power-on time control process.

Then, the power supply voltage detection routine ends at the same time as the processing at S800 ends, and the processing shifts to the power-on time control processing again. Note that the power supply voltage detection routine is started by the process of S250 in the energization time control process and then performed in the above-described processes from S710 to S800 until the ignition command signal IG is output from the ECU 31 in the next combustion cycle. To end.

When the power supply voltage detection routine is completed and the process proceeds to S250 of the energization time control process,
The process in S250 ends, and the process moves to S130. In the energization time control process thereafter, the energization start delay time Ts calculated in the primary current detection routine for each combustion cycle is used based on the energization start delay time Ts updated in the power supply voltage detection routine. Make the correction,
The delay control (power-on time setting control) of the power-on start timing of the primary current i1 is executed. After that, the processes from S130 to S240 are repeatedly executed, and the delay process of the energization start timing in the five combustion cycles is performed. When the determination is affirmative in S240, the power supply voltage detection routine is executed again, and The energization start delay time Ts is updated.

In the ignition device for an internal combustion engine of this embodiment, the main control transistor 15 corresponds to the switching means described in the claims, and the ECU 31 for executing the ignition control processing corresponds to the ignition control means. The power supply voltage detection circuit 27 and the microcomputer 21 for detecting the power supply voltage value correspond to the power supply voltage detection means, and the primary current detection circuit 33 and the microcomputer 21 for detecting (calculating) the maximum value of the primary current serve as the primary current detection means. That is, the filter circuit 37 corresponds to a noise removing unit, and the microcomputer 21 and the conduction delaying transistor 25 correspond to a conduction time control unit.

As described above, in the ignition device for an internal combustion engine of the present embodiment, the ignition control process executed by the ECU 31 changes the ignition command signal IG to the high level in order to start energizing the primary winding L1. Even if the state is output, the energization to the primary winding is not necessarily started at the timing when the ignition command signal IG is output. That is, the microcomputer 21
While the energization time control process executed in step (1) keeps the energization start delay signal Sb at the high level, the main control transistor 15 is maintained in the off state regardless of the state of the ignition command signal IG. No current is supplied to the winding L1.

After the ignition command signal IG changes to the high level, when the energization start delay time Ts set according to the detected primary current and the power supply voltage value elapses, the energization start delay signal Sb changes to the low level. The state changes, and the power supply to the primary winding L1 is started at this timing.

That is, in the ignition device for an internal combustion engine, the microcomputer 21 for executing the energization time control processing is provided to delay the energization timing to the primary winding L1 according to the detected maximum value of the primary current and the power supply voltage value. By controlling the primary current conduction time in this way, the maximum value of the primary current i1 flowing through the primary winding L1 is controlled to be constant. As a result, the magnetic flux energy stored in the ignition coil 13 is kept substantially constant even when there is variation between the individual ignition coils due to variations in the winding resistance and inductance of the ignition coil 13 and when the power supply voltage fluctuates. You can do it.

Note that the microcomputer 21 and the power supply delay transistor 25 control only the power supply start time to the primary winding L1, and do not change the cutoff time of the primary current i1, that is, the ignition timing. Timing is ECU31
Is determined by Thus, the provision of the microcomputer 21 and the energization delay transistor 25 does not affect the ignition timing. Further, for some reason, the maximum value of the primary current cannot be detected by the microcomputer 21.
Even if the power supply start delay signal Sb cannot be output, the power supply delay transistor 25 is turned off, so that the main control transistor 15 is controlled by the ECU 31 to control the supply and cutoff of the primary current i1. Therefore, it is possible to at least continue the operation of the internal combustion engine.

Further, in this embodiment, the maximum value of the primary current is detected independently of the ECU 31 which executes many control processes such as ignition control, fuel injection amount, air-fuel ratio, fuel injection timing, and the like. A microcomputer 21 for performing a control process for setting an energization time to the primary winding and an energization delay transistor 25 (that is, energization time control means) are provided. For this reason, according to the ignition device for an internal combustion engine of the present embodiment, each control process such as the ignition control process in the ECU 31 is performed without increasing the processing load of the ECU 31 in performing the energization time control process for the primary winding. It can be executed normally.

Further, in setting the energization start delay time Ts, when the primary current average correction value Iavc is equal to or less than the primary current target value It, the energization start delay time Ts is set short to increase the primary current energization time. , And conversely, the primary current average correction value Iavc is the primary current target value It
If it is larger, the energization start delay time Ts is set longer. As described above, by changing the primary current conduction time based on the comparison result between the detected primary current i1 and the primary current target value It, the magnetic flux energy accumulated in the ignition coil can be made closer to the optimum value. Therefore, according to the ignition device for an internal combustion engine of the present embodiment, heat generation in the main control transistor 15 does not become excessive, and magnetic flux energy for generating spark discharge is reliably stored in the ignition coil. Can be.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and can take various forms. Next, as a second embodiment, the primary current detection signal S1 from the detection resistor 35 (primary current detection circuit 33) is input, and the post-machining ignition command signal Sa of the above embodiment (hereinafter, referred to as the first embodiment). FIG. 7 shows an internal combustion engine ignition device 1 provided with an ECU 31 for performing a control process of outputting an ignition command signal IG indicating the same state change as in FIG.
Shown in

As shown in FIG. 7, an ignition device 1 for an internal combustion engine according to the second embodiment converts an AC voltage of a commercial power supply and outputs a DC voltage for discharge (for example, a power supply voltage of 12 [V]). A power supply device 11, an ignition coil 13 having a primary winding L1 and a secondary winding L2, and a main control transistor 1 composed of an npn-type transistor connected in series with the primary winding L1
5, a main control transistor 15 for forming a closed loop with the secondary winding L2 and for generating a spark discharge between the spark plug 17 provided in the cylinder of the internal combustion engine and the electrodes 17a-17b of the spark plug 17. And an electronic control unit (hereinafter referred to as ECU) 31 for controlling the internal combustion engine, which outputs an ignition command signal IG according to the operating state of the internal combustion engine, and a primary current i1 flowing through the primary winding L1. And a detection resistor 35.

Note that, of the components of the ignition device for an internal combustion engine of the second embodiment, the same components as those of the first embodiment are denoted by the same reference numerals. However, the same reference numerals are given to the ECU 31, but the contents of the internal processing are partially different. The detection resistor 35 also corresponds to the primary current detection circuit 33.

In the ECU 31 of the second embodiment, in addition to the control process executed by the ECU 31 of the first embodiment, a control process corresponding to a primary current detection routine executed by the microcomputer 21 of the first embodiment is performed. Is performed for each combustion cycle, and the power supply start delay time Ts is set based on the detected primary current i1 (that is, in the second embodiment, the ECU 31
Corresponds to ignition control means, primary current detection means, and conduction time control means). Also, there is a difference in the processing content of the ignition control processing, and the output timing of the ignition command signal IG is determined according to the energization start delay time Ts set in the primary current detection routine. That is, the high-level output of the ignition command signal IG is executed at the end of the high-level output of the energization start delay signal Sb in the energization time control process of the first embodiment. Accordingly, the ignition command signal IG shows the same state change as the post-machining ignition command signal Sa of the first embodiment.

In the ECU 31 of the second embodiment, the detection of the primary current detection signal S1 is executed a plurality of times at regular intervals during the period from the start of energization to after the energization is cut off, and the maximum value in one combustion cycle is determined by the primary current Detected as the primary current value at the time of energization interruption. Specifically, at time t2 in FIG.
The primary current detected at regular intervals is stored during a period from the time t3 to several μs after the time t3, and the maximum value of the stored primary current value is detected as the primary current when the primary current is cut off. Then, by controlling the primary current supply time based on the maximum value of the primary current detected in this way, the maximum value of the primary current is controlled to be constant.

Therefore, in the internal combustion engine ignition device of the second embodiment, the ECU 31 sets the primary current energizing time based on the detected primary current, and outputs the ignition command signal IG in accordance with the primary current energizing time. Controls the magnetic flux energy accumulated in the ignition coil to be substantially constant.

Next, as a third embodiment, the primary current conduction time is set based on the detected primary current except for the power supply voltage detection circuit 27 and the filter circuit 37 from the internal combustion engine ignition device of the first embodiment. FIG. 8 shows an ignition device for an internal combustion engine. As shown in FIG. 8, an ignition device 1 for an internal combustion engine according to a third embodiment converts an AC voltage of a commercial power supply and outputs a DC voltage for discharge (for example, a power supply voltage 12 [V]). An ignition coil 13 having a primary winding L1 and a secondary winding L2, a main control transistor 15 composed of an npn-type transistor connected in series with the primary winding L1, and a secondary winding L2 and a closed loop. In order to generate spark discharge between the spark plug 17 provided in the cylinder of the internal combustion engine and the electrodes 17 a-17 b of the spark plug 17, the main control transistor 15 is controlled according to the operating state of the internal combustion engine. An electronic control unit (hereinafter referred to as an ECU) 31 for controlling the internal combustion engine which outputs an ignition command signal IG, a microcomputer 21 for delaying the start of energization to the primary winding, and a DC power supply 11 Driving voltage for driving the microcomputer 21 transforms the power supply voltage (e.g., 5 [V])
And a main control transistor 15 based on an energization start delay signal Sb from the microcomputer 21.
And a detection resistor 35 for detecting a primary current i1 flowing through the primary winding L1;
It has.

[0127] Of the components of the ignition device for an internal combustion engine of the third embodiment, the same reference numerals are given to the same components as those of the first embodiment. However, the same reference numerals are given to the microcomputer 21, but the contents of the internal processing are partially different. Also,
The detection resistor 35 also corresponds to the primary current detection circuit 33.

In the internal combustion engine ignition device 1 of the third embodiment, the ECU 31 executes the same control processing as the ECU 31 of the first embodiment, and outputs an ignition command signal IG. Further, the microcomputer 21 receives the primary current detection signal S1 and performs the energization time control processing as S110, S230, S240, S25 in the flowchart shown in FIG.
0 is deleted, and the process is executed according to the changed flowchart so that the process proceeds to S130 after the process of S220. Thus, the energization start delay time Ts is set based on the primary current detected in the primary current detection routine, and the energization start delay signal Sb is output to set the primary current energization time to the primary winding. .

Therefore, in the internal combustion engine ignition device according to the third embodiment, the microcomputer 21 executes the control processing of the primary current energizing time based on the detected maximum value of the primary current, so that the magnetic flux energy accumulated in the ignition coil is controlled. Is controlled almost constant. Next, as a fourth embodiment, an internal combustion engine in which a filter circuit 37 as a low-pass filter including a resistor R4 and a capacitor C1 is added to the signal path of the primary current detection signal S1 in the internal combustion engine ignition device of the third embodiment. FIG. 9 shows an ignition device for a vehicle.

As shown in FIG. 9, one end of the filter circuit 37 of the ignition device 1 for an internal combustion engine according to the fourth embodiment is connected to the connection point between the detection resistor 35 and the main control transistor 15, and the other end is connected. A resistor R4 connected to the input terminal of the primary current detection signal S1 in the microcomputer 21;
And a capacitor C1 provided between the end of the resistor R4 connected to the ground and the ground. The detection resistor 35 and the filter circuit 37 are connected to the primary current detection circuit 3.
3. Therefore, according to the ignition device for an internal combustion engine of the fourth embodiment, the influence of noise when detecting the primary current detection signal S1 can be suppressed as compared with the third embodiment, and the primary current can be detected with high accuracy. be able to.

[0131] Of the components in the ignition device for an internal combustion engine according to the fourth embodiment, the same reference numerals are given to the same components as those in the third embodiment. Next, as a fifth embodiment, an ignition device for an internal combustion engine provided with a peak hold circuit 41 which holds a peak value (maximum value) of a voltage between both ends of a detection resistor 35 and outputs the same as a primary current detection signal S1 is shown in FIG. Shown in

As shown in FIG. 10, the internal combustion engine igniter of the fifth embodiment has a configuration in which a peak hold circuit 41 is added to the internal combustion engine igniter of the second embodiment shown in FIG. The hold circuit 41 is provided in a signal path from a connection point between the main control transistor 15 and the detection resistor 35 to an input terminal of the primary current detection signal S1 in the ECU 31. The detection resistor 35 and the peak hold circuit 41 constitute the primary current detection circuit 33.

Note that, of the components in the ignition device for an internal combustion engine of the fifth embodiment, the same components as those of the second embodiment are denoted by the same reference numerals. The peak hold circuit 41 includes a diode D4 having an anode connected to a connection point between the main control transistor 15 and the detection resistor 35, one end connected to the cathode of the diode D4, and the other end connected to ground (ground). ), And a reset transistor 43 composed of an npn-type transistor whose collector is connected to the cathode of the diode D4 via a resistor R5. The cathode of the diode D4 is connected to the ECU 3
1 is connected to the input terminal of the primary current detection signal S1. The reset transistor 43 has a base E
The CU 31 is connected to the output terminal of the reset signal Sc, and the emitter is connected to the ground (ground).

In the thus configured peak hold circuit 41, the capacitor C2 is charged so as to have a potential difference equal to the voltage Vr across the detection resistor 35, and the discharge of the capacitor C2 is limited by the diode D4. Therefore, the voltage across the capacitor C2 holds the maximum value of the voltage Vr across the detection resistor 35. Note that the voltage across the capacitor C2 is held while the reset transistor 43 is in the off state, and when the reset transistor 43 is turned on, the electric charge accumulated in the capacitor C2 causes the resistance R5 and the reset Discharged through the transistor 43.

The reset signal Sc for driving and controlling the reset transistor 43 is output from the ECU 31 and is output as a pulse signal having a constant pulse width simultaneously with the high-level output timing of the ignition command signal IG. Note that the pulse width of the reset signal Sc is set in advance according to the time required for discharging the capacitor C2, and the capacitor C2 is used as the time during which the ignition command signal IG continues to be at a high level (in other words, the primary winding). (E.g., the time required to energize the wire).

Here, FIG. 12 shows the ignition command signal IG and the primary current i in the ignition device for an internal combustion engine shown in FIG.
1 is a time chart showing respective states of a primary current detection signal S1 and a reset signal Sc. First, when the ignition command signal IG switches from low to high at time t11 in FIG. 12, the main control transistor 15 is turned on and the primary current i1 starts flowing.

Thereafter, the primary current supply cutoff timing (time t
At 12), when the ignition command signal IG goes low and the main control transistor 15 is turned off, the primary current i
1 stops flowing. However, since the voltage across the capacitor C2 maintains the voltage across the detection resistor 35 when the primary current i1 is maximized, the primary current detection signal S1 is held at a value representing the maximum value of the primary current i1. You.

Thereafter, when the primary current supply cutoff timing (time t13) in the next combustion cycle comes, the ECU 31
Outputs the reset signal Sc at the high level together with the ignition command signal IG, so that the reset transistor 43 is turned on, the capacitor C2 is discharged, and the primary current detection signal S1 is reset.

Therefore, the ECU 31 only needs to detect the primary current i1 at one point during the period from time t12 to time t13 in FIG. Then, similarly to the second embodiment, the ECU 31 of the fifth embodiment executes a control process corresponding to a primary current detection routine for each combustion cycle, and determines an energization start delay time Ts based on the detected primary current i1. The detection timing of the primary current i1 is set to the time when the processing load is the lowest during the period from time t12 to time t13 in FIG. Further, as the ignition control process, the same process as that of the second embodiment is executed, and the ignition command signal IG shows the same state change as the post-machining ignition command signal Sa of the first embodiment.

In the ignition device for an internal combustion engine according to the fifth embodiment having the above-described structure, the ECU 31 executes the control process of the primary current energizing time based on the detected maximum value of the primary current, so that the ignition coil is controlled. The accumulated magnetic flux energy is controlled to be substantially constant. Further, as a sixth embodiment, FIG.
An ignition device for an internal combustion engine in which a peak hold circuit 41 is added to the ignition device for an internal combustion engine of the third embodiment shown in FIG.
Shown in

As shown in FIG. 11, the internal combustion engine igniter of the sixth embodiment has a configuration in which a peak hold circuit 41 is added to the internal combustion engine igniter of the third embodiment shown in FIG. The hold circuit 41 is provided in a signal path from a connection point between the main control transistor 15 and the detection resistor 35 to an input terminal of the primary current detection signal S1 in the microcomputer 21. The detection resistor 35 and the peak hold circuit 41 constitute the primary current detection circuit 33.

Note that, of the components in the ignition device for an internal combustion engine according to the sixth embodiment, the same components as those in the third embodiment are denoted by the same reference numerals. The peak hold circuit 41 includes a diode D4 having an anode connected to a connection point between the main control transistor 15 and the detection resistor 35, one end connected to the cathode of the diode D4, and the other end connected to ground (ground). ), And a reset transistor 43 composed of an npn-type transistor whose collector is connected to the cathode of the diode D4 via a resistor R5. The cathode of the diode D4 is connected to the input terminal of the primary current detection signal S1 of the microcomputer 21. The reset transistor 43 has a base connected to the output terminal of the microcomputer 21 for the reset signal Sc,
The emitter is connected (grounded) to ground.

In the peak hold circuit 41 thus configured, the capacitor C2 is charged so as to have a potential difference equal to the voltage Vr across the detection resistor 35, and the discharge of the capacitor C2 is limited by the diode D4. Therefore, the voltage across the capacitor C2 holds the maximum value of the voltage Vr across the detection resistor 35. Note that the voltage across the capacitor C2 is held while the reset transistor 43 is in the off state, and when the reset transistor 43 is turned on, the electric charge accumulated in the capacitor C2 causes the resistance R5 and the reset Discharged through the transistor 43.

The reset signal Sc for controlling the drive of the reset transistor 43 is output from the microcomputer 21 and is output as a pulse signal having a constant pulse width simultaneously with the high-level output timing of the ignition command signal IG. Note that the pulse width of the reset signal Sc is set in advance according to the time required for discharging the capacitor C2, and the capacitor C2 is used as the time during which the ignition command signal IG continues to be at a high level (in other words, the primary winding). (E.g., the time required to energize the wire).

FIG. 12 is a time chart showing the states of the post-machining ignition command signal Sa, the primary current i1, the primary current detection signal S1, and the reset signal Sc in the ignition device for an internal combustion engine shown in FIG. Command signal IG
Is the same as the time chart when the post-processing ignition command signal Sa is replaced.

For this reason, the microcomputer 21 outputs the primary current i1
May be detected at one point during the period from time t12 to time t13 in FIG. And
The microcomputer 21 according to the sixth embodiment receives the primary current detection signal S1 and performs the energization time control processing as S110, S230, S24 in the flowchart shown in FIG.
0, the process of S250 is deleted, and after the process of S220, S
The processing is changed to shift to 130, and the processing in S180 is changed. In S180, the primary current detection time Tm is set so that the primary current i1 is detected at the time when the processing load is the lowest during the period from time t12 to time t13 in FIG.

As a primary current detection routine, FIG.
The processing from S420 to S470 in the flowchart shown in (1) is deleted, and the processing in S480 is executed according to the flowchart changed to the processing for setting the primary current i1 detected in S410 to the primary current average correction value Iavc. The energization start delay time Ts is set based on the primary current detected in the primary current detection routine in this way, and the energization time to the primary winding is set by outputting the energization start delay signal Sb.

In the ignition device for an internal combustion engine according to the sixth embodiment having the above-described structure, the microcomputer 21 executes the control process of the primary current energizing time based on the detected maximum value of the primary current, so that the ignition coil is controlled. Is controlled to be substantially constant. As mentioned above, although the several Example of this invention was described, this invention is not limited to the said Example, For example, as a power supply device, it changes the AC voltage from a commercial power supply, and outputs a DC voltage. The ignition device for an internal combustion engine of the present invention can also be realized in a configuration using a battery that outputs charged electric energy as a DC voltage instead of a power supply device.

Further, for example, a change in the primary current in a period from the start of energization to a predetermined time before the cutoff of current is detected, and the current value (maximum value) of the primary current at the time of cutoff of the primary current is detected from the change. Prediction may be made to set the primary current supply time.

Further, in the energization time control process described in the above embodiment, the maximum value of the primary current and the power supply voltage value are detected for each cylinder, and the primary current energization time in the next combustion cycle of the cylinder is controlled. However, in the case of an internal combustion engine having a plurality of cylinders, the primary current energizing time in the cylinder next to the cylinder in which the primary current and the power supply voltage value are detected may be controlled. Further, in an internal combustion engine having a plurality of cylinders, for example, a moving average value is calculated by using a maximum value of a plurality of primary currents detected in each of the plurality of cylinders, so that a primary current energizing time of one cylinder is calculated. May be controlled.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a schematic configuration of an internal combustion engine ignition device according to a first embodiment.

FIG. 2 is a time chart showing the state of each part of the internal combustion engine ignition device of the first embodiment.

FIG. 3 is an explanatory diagram illustrating waveforms of primary currents when a power supply voltage is high and when a power supply voltage is low.

FIG. 4 is a flowchart showing processing contents of an energization time control processing.

FIG. 5 is a flowchart illustrating processing contents of a primary current detection routine.

FIG. 6 is a flowchart illustrating processing contents of a power supply voltage detection routine.

FIG. 7 is a configuration diagram illustrating a schematic configuration of an ignition device for an internal combustion engine according to a second embodiment.

FIG. 8 is a configuration diagram illustrating a schematic configuration of an ignition device for an internal combustion engine according to a third embodiment.

FIG. 9 is a configuration diagram illustrating a schematic configuration of an internal combustion engine ignition device according to a fourth embodiment.

FIG. 10 is a configuration diagram illustrating a schematic configuration of an internal combustion engine ignition device according to a fifth embodiment.

FIG. 11 is a configuration diagram illustrating a schematic configuration of an ignition device for an internal combustion engine according to a sixth embodiment.

FIG. 12 is a time chart showing the state of each part of the internal combustion engine ignition device according to the fifth embodiment and the sixth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ignition device for internal combustion engine, 11 ... DC power supply device, 13 ...
Ignition coil, 15: Main control transistor, 17: Spark plug, 21: Microcomputer, 2
3 ... voltage conversion circuit, 25 ... transistor delay transistor, 2
7: power supply voltage detection circuit, 31: electronic control unit (ECU)
33: primary current detection circuit, 35: detection resistor, 37: filter circuit, 41: peak hold circuit, 43: reset transistor, C1: capacitor, C2: capacitor, L1: primary winding, L2: secondary winding .

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G019 AA00 BA01 BA05 CC03 CC15 DA04 DA05 DA07 DB02 DB07 DB16 DC07 EA13 EA15 EA16 FA04 FA14 FA23 GA07 3G092 AB06 AC08 BA08 DF05 EA16 EA17 EB01 FA38 FA50 HA11Z HE01Z

Claims (9)

[Claims] An ignition coil having a primary winding through which a primary current flows when a power supply voltage is applied from a power supply device, a secondary winding forming a closed loop with an ignition plug mounted on the internal combustion engine, A switching means for forming a closed loop together with the primary winding and the power supply device, supplying and interrupting the primary current flowing through the primary winding, and an ignition command signal corresponding to an operation state of the internal combustion engine to the switching means. An ignition control means for outputting an output, wherein the primary current is supplied and interrupted by on / off control of the switching means to generate a high voltage for ignition in the secondary winding. A primary current detecting means for detecting a primary current flowing through the primary winding; and a primary current detecting means for detecting a primary current flowing through the primary winding based on a maximum value of the primary current detected by the primary current detecting means. Ignition device for an internal combustion engine characterized by comprising energizing time control means for controlling the current supply time, the. 2. The current supply time control means controls the primary current supply time to be shorter when the detected maximum value of the primary current is larger than a predetermined target value. 2. The ignition device for an internal combustion engine according to claim 1, wherein when the maximum value is equal to or less than the target value, the primary current supply time is controlled to be long. 3. The power supply time control means according to claim 1, wherein the power supply time control means controls the primary current supply time within a range in which spark discharge can be generated in the spark plug. An ignition device for an internal combustion engine. 4. The ignition device for an internal combustion engine according to claim 1, further comprising: a power supply voltage detection unit configured to detect a power supply voltage value output from the power supply device. The ignition device for an internal combustion engine, wherein the energization time control means controls the primary current energization time based on a maximum value of the primary current and a power supply voltage value detected by the power supply voltage detection means. 5. The energization time control means detects a primary current value a predetermined time before a primary current energization cutoff time at which the energization of the primary current is interrupted by the OFF control of the switching means. The ignition device for an internal combustion engine according to claim 4, wherein, based on a power supply voltage value detected by the power supply voltage detection means, the primary current value is corrected to calculate a maximum value of the primary current. . 6. The apparatus according to claim 1, wherein the power supply time control means is provided in a form independent of an ignition control means for outputting the ignition command signal. Ignition device for internal combustion engines. 7. The primary current detecting means includes a noise removing means for preventing intrusion of noise when detecting a primary current flowing through the primary winding. The ignition device for an internal combustion engine according to any one of the above. 8. The ignition device for an internal combustion engine according to claim 1, wherein the energization time control means controls the primary current energization time in a stepwise manner. 9. The engine according to claim 1, wherein the internal combustion engine is a gas engine using gaseous fuel as fuel.
An ignition device for an internal combustion engine according to any one of claims 1 to 8.