JP2001304083A - Igniter for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an igniter for an internal combustion engine capable of preventing the occurrence of a large loss in a primary winding of an ignition coil and a primary current control switch and the occurrence of excessiveness of secondary induced voltage of the ignition coil. SOLUTION: High voltage is induced to a secondary winding W2 of the ignition coil 1 by cutting off a primary current of the ignition coil l by controlling a transistor TRI by an ignition control device 6. A source voltage detecting circuit 12 is arranged for detecting output voltage of a battery 4. The ignition control device 6 is constituted so as to decide the current-carrying starting timing of the primary current according to the voltage detected by the source voltage detecting circuit 12 for restraining a cutoff value of the primary current of the ignition coil 1 in a prescribed range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current interruption type ignition device for an internal combustion engine.

[0002]

2. Description of the Related Art A current interrupt type ignition device for an internal combustion engine supplies an ignition coil having a secondary winding connected to an ignition plug attached to a cylinder of the internal combustion engine and a primary current to a primary winding of the ignition coil. A DC power source such as a battery to be turned on, a primary current control switch that turns on and off a primary current of an ignition coil in response to a control signal, and a start time of energization of the primary current of the ignition coil and an ignition timing of the internal combustion engine. An ignition control device that starts energizing the primary current to the ignition coil when the determined energization start timing is detected, and provides a control signal to a primary current control switch so as to cut off the primary current when the determined ignition timing is detected. It consists of.

In this type of ignition device, an ignition control device supplies a drive signal to a primary current control switch at an energization start timing set before an ignition timing of an engine. As a result, the primary current control switch is turned on, and a primary current flows from the DC power supply through the primary winding of the ignition coil and the primary current control switch. The ignition control device turns off the drive signal supplied to the primary current control switch when the ignition timing of the internal combustion engine is detected, thereby turning off the switch. As a result, the primary current flowing through the ignition coil is cut off, and a high voltage for ignition is induced in the secondary winding of the ignition coil.

FIG. 8 schematically shows the structure of a conventional ignition device of this type. In FIG. 8, reference numeral 1 denotes an ignition coil having a primary winding W1 and a secondary winding W2 having one end commonly connected. It is. The other end of the secondary winding W2 of the ignition coil 1 is connected through a high-voltage cord to a non-ground terminal of an ignition plug 2 attached to a cylinder of an internal combustion engine (not shown). In this example, it is assumed that a single-cylinder internal combustion engine is ignited.

[0005] Reference numeral 3 denotes a primary current control switch. In the illustrated example, this switch is constituted by an NPN transistor TR1. The emitter of the transistor TR1 is grounded, and its collector is connected to the other end of the primary winding W1 of the ignition coil.

Reference numeral 4 denotes a battery for supplying a primary current to the ignition coil 1. A negative terminal of the battery 4 is grounded, and a positive terminal is connected to one end of a primary winding W1 through a switch 5 which is closed when the internal combustion engine is started. It is connected to a common connection point with one end of the winding W2. The battery 4 is charged through the charging circuit by the output of a magnet generator (not shown) driven by the internal combustion engine.

Reference numeral 6 denotes an ignition control device for providing a control signal to the primary current control switch 3. This control device is provided in a microcomputer 7 and a signal generator attached to the internal combustion engine to specify the internal combustion engine. A pulser coil 8 for generating a pulse signal at the rotation angle position of the above, a waveform shaping circuit 9 for shaping the waveform of the output of the pulser coil 8 and applying it to a microcomputer 7, and a base current ( And an ignition drive circuit 10 for giving an ignition control signal).

Reference numeral 11 denotes a power supply circuit for outputting a constant DC voltage with the output of the battery 4 as an input. The output voltage of this power supply circuit is supplied to the microcomputer 7 as a power supply voltage.

In the ignition device shown in FIG.
As shown in FIG. 9A, the rotation angle position of the engine is
A first pulse signal Vs1 is generated at a first timing t1 at which the state coincides with a first rotation angle position set at a position advanced sufficiently from the top dead center TDC of the engine, and the rotation of the engine is started. The second angular position is set near the top dead center TDC.
A second pulse signal having a polarity different from that of the first pulse signal is generated at a second timing t2 at which the state coincides with the rotational angle position. These pulse signals are converted into signals having waveforms recognizable by the microcomputer by the waveform shaping circuit 9 and input to the microcomputer 7.

In the illustrated example, the first pulse signal is composed of a positive pulse and the second pulse signal is composed of a negative pulse.
The first pulse signal may be a negative pulse and the second pulse signal may be a positive pulse.

The microcomputer 7 measures a rotation speed calculation time Tn from the first timing t1 at which the first pulse signal Vs1 is generated to the next first timing t1 after the engine makes one rotation. The engine speed N [rpm] is calculated from the time Tn. The microcomputer 7 uses this rotation speed N as one of the control conditions and
From the timing t2 to the ignition timing ti of the engine at each rotation speed N (ignition timing measurement time), and the energization time of the primary current i1 (the time during which the primary current flows through the ignition coil) Ton. Generates the pulse signal Vs2 at the second timing t2, the time (Ti -T) from the second timing t2 to the energization start timing ton
On) (power supply start time measurement time) is set in a timer in the microcomputer 7 to start the measurement.

The microcomputer 7 gives an ignition start command to the ignition drive circuit 10 when the timer measures the energization start timing measurement time (Ti-Ton), and the microcomputer 10 supplies a base current (ignition control signal) to the transistor TR1. Supply). As a result, the transistor TR1 is turned on, and the primary current i1 flows from the battery 4 to the ignition coil 1 as shown in FIG. In FIG. 9B, a curve a indicates the primary current i1 flowing when the output voltage of the battery 4 is Ea [V], and a curve b indicates the primary current i1 when the output voltage of the battery 4 is Eb (> Ea) [V]. This shows the flowing primary current i1.

When the timer measures (Ti-Ton), the microcomputer 7 sets a new energizing time Ton in the timer and starts the measurement. When the energizing time Ton is measured (ignition When the timing ti is detected), a shut-off command is given to the ignition drive circuit 10 so that the transistor T
The supply of the base current to R1 is stopped. As a result, the transistor TR1 is turned off, the primary current i1 of the ignition coil is cut off, and a high voltage for ignition is induced in the secondary winding W2 of the ignition coil. Since this high voltage is applied to the spark plug 2, a spark is generated in the spark plug and the engine is ignited.

[0014]

In the above-described current cutoff type ignition device for an internal combustion engine, the cutoff value of the primary current of the ignition coil (current value at the time of cutoff) is applied to the secondary winding of the ignition coil. The peak value of the induced high voltage is determined, and the higher the cutoff value of the primary current, the higher the secondary induced voltage.

FIG. 4 shows a primary current i flowing when a DC voltage E of various magnitudes is applied to the primary coil of the ignition coil.
1 is a graph showing the change of the time t with respect to time t. In FIG. 4, curves a, b, and c show characteristics when the DC voltage applied to the primary winding is Ea, Eb, and Ec, respectively.
Isa, Isb and Isc indicate the saturation current values of the primary current flowing when the power supply voltages are Ea, Eb and Ec, respectively. That is, Isa, Isb and Isc indicate the maximum values of the primary current flowing when the power supply voltage E is Ea, Eb and Ec, respectively. When the power supply voltage E is Ea, Eb, and Ec, the time required for the primary current to reach the maximum value is Ta, Tb, and Tc, respectively. The lower the power supply voltage E is, the more the primary current reaches the maximum value. It takes longer time.

Now, it is assumed that the voltage applied from the DC power supply 4 to the primary winding of the ignition coil at the start of the engine when the battery voltage drops is Ea shown in FIG. If it is necessary to set the cutoff value of the primary current to Isa in order to obtain a high voltage, it is necessary to set the conduction time of the primary current to at least Ta. However, when the battery voltage recovers as the engine speed increases and rises to Eb, the cutoff value of the primary current rises to Isb, and the voltage induced in the secondary winding of the ignition coil becomes excessive. turn into. If the secondary voltage of the ignition coil becomes excessive, the consumption of the ignition plug becomes severe, and the life thereof is shortened, which is not preferable.

In order to set the cutoff value of the primary current to the required value Isa when the power supply voltage is Eb, the energizing time is set to Td.
(<Tb), and when the power supply voltage is Ec, the energization time can be reduced to Te (<< Tb). In this case, if the energizing time is kept at Ta, the primary current flows for an unnecessarily long time,
Heat generation in the ignition coil 1 and the transistor TR1 increases, which is not preferable.

An object of the present invention is to control an energizing time of a primary current of an ignition coil in accordance with an output voltage of a DC power supply, so that an unnecessarily large secondary induced voltage is generated in the ignition coil, It is an object of the present invention to provide a current interruption type ignition device for an internal combustion engine which can prevent a large loss from occurring in a primary winding and a primary current control switch.

[0019]

SUMMARY OF THE INVENTION The present invention relates to an ignition coil having a secondary winding connected to an ignition plug attached to a cylinder of an internal combustion engine, and a direct current supplying a primary current to a primary winding of the ignition coil. A power supply, a primary current control switch that controls on / off of a primary current of the ignition coil in response to a control signal,
The primary current supply to the ignition coil is started when the current supply start time determined by determining the current supply start time of the primary current of the ignition coil and the ignition timing of the internal combustion engine is detected, and the primary current is supplied when the determined ignition timing is detected. And an ignition control device for supplying a control signal to a primary current control switch so as to cut off the current.

In the present invention, a power supply voltage detection circuit for detecting an output voltage of the DC power supply is provided, and the voltage detected by the power supply voltage detection circuit is adjusted to keep the cutoff value of the primary current of the ignition coil within a predetermined range. The ignition control device is configured to determine the timing for starting the supply of the primary current accordingly.

As described above, when the start of energization of the primary current of the ignition coil is controlled in accordance with the output voltage of the DC power supply so that the cutoff value of the primary current falls within a predetermined range, the power supply voltage increases. Sometimes, it is possible to prevent the cutoff value of the primary current from becoming excessive and the secondary induced voltage of the ignition coil from becoming excessive.

Further, as described above, when the energization start timing is controlled in accordance with the power supply voltage so that the cutoff value of the primary current falls within a predetermined range, when the power supply voltage rises, the energization time of the primary current becomes longer than necessary. To prevent it from becoming longer,
It is possible to prevent a large amount of energy from being consumed by the primary winding and the primary current control switch of the ignition coil, thereby preventing heat generation in these portions from increasing.

In the present invention, at least one sensor for detecting a control condition used for determining a cutoff value of the primary current of the ignition coil is provided in addition to the power supply voltage detecting circuit for detecting the output voltage of the DC power supply. In order to set the cutoff value of the primary current of the ignition coil to a value determined according to the control condition detected by the sensor, the primary current is controlled according to the control condition detected by the sensor and the voltage detected by the power supply voltage detection circuit. The ignition control device may be configured to determine the power supply start timing of the ignition.

For example, a throttle sensor for detecting a throttle valve opening is provided as the sensor, and a time change rate of the throttle valve opening detected by the throttle sensor is calculated, and the calculated time change of the valve opening is calculated. When the rate exceeds the set value, it is determined that an operation of rapidly accelerating the internal combustion engine has been performed, and the cutoff value of the primary current of the ignition coil can be increased.

When the internal combustion engine is rapidly accelerated, it is preferable to increase the secondary induction voltage of the ignition coil to increase the ignition energy. Therefore, when the rapid acceleration operation is performed, the primary When the control for increasing the cutoff value of the winding is performed, rapid acceleration of the engine can be performed smoothly.

In the present invention, there is further provided an external command switch for indicating a cutoff value of a primary current of the ignition coil or a magnitude of a voltage induced in a secondary winding of the ignition coil when the primary current of the ignition coil is cut off. The external value is set so that the cutoff value of the primary current of the ignition coil or the magnitude of the voltage induced in the secondary winding of the ignition coil when the primary current of the ignition coil is cut off has the magnitude indicated by the external command switch. It is also possible to control the timing of starting the supply of the primary current according to the instruction given by the command switch and the voltage detected by the power supply voltage detection circuit.

With this configuration, the cutoff value of the primary current is switched according to the winding specification of the ignition coil so that ignition coils having various winding specifications can be used, or the ignition coil can be used according to the purpose of use of the engine. The cutoff value of the primary current can be switched.

In the above description, the start timing of the primary current is determined so that the cutoff value of the primary current falls within the predetermined range. However, the high voltage induced in the secondary winding of the ignition coil is set within the predetermined range. The same effect can be obtained even if the timing of starting the supply of the primary current is determined so as to fall within the range.

[0029]

FIG. 1 schematically shows a hardware configuration of an ignition device for an internal combustion engine according to the present invention. In FIG. 1, reference numeral 1 denotes a primary winding W1 and a secondary winding W2.
2, an ignition plug attached to a cylinder of the internal combustion engine, 3 a primary current control switch composed of an NPN transistor TR1, and 4 an electric charge of a magnet generator driven by the internal combustion engine through a charging circuit. A battery as a DC power source, 5 a switch closed when starting the internal combustion engine, 6 a microcomputer 7
An ignition control device including a pulsar coil 8 and an ignition drive circuit 10 is a power supply circuit for applying a power supply voltage to the microcomputer 7.
This is the same as the ignition device shown in FIG.

In the present invention, a resistor voltage dividing circuit composed of a series circuit of resistors R1 and R2 is connected between one end of the primary winding W1 of the ignition coil 1 and the ground, and provided on the ground side of the voltage dividing circuit. A Zener diode ZD1 for limiting the divided output is connected to both ends of the resistor R2 with its anode facing the ground. The power supply voltage detecting circuit 12 for detecting the output voltage of the battery 4 is constituted by the resistors R1 and R2 and the Zener diode ZD1. The output voltage of the power supply voltage detection circuit 12 is input to the CPU of the microcomputer 7 through an A / D converter 7a provided in the microcomputer 7.

In the ignition device for an internal combustion engine shown in FIG. 1, the power supply voltage detection circuit 12 outputs a detection voltage proportional to the output voltage of the battery 4. The detection voltage data PA is supplied to an A / D converter 7a of the microcomputer 7 and converted into a digital signal. The pulsar coil 8 is shown in FIG.
As shown in (A), the first rotation angle position of the rotation shaft of the engine coincides with the first position set at a position advanced enough from the position corresponding to the top dead center of the piston of the engine. A first pulse signal Vs1 is generated at a timing t1, and a second pulse signal Vs2 is generated at a second timing t2 at which the rotation angle position of the rotating shaft of the engine coincides with a second position set near top dead center. appear. These pulse signals are supplied to a waveform shaping circuit 9.
Through the microcomputer 7.

The microcomputer 7 executes the program stored in the ROM to control the time for supplying the primary current of the ignition coil and to control the ignition timing. In the microcomputer, the pulsar coil 8 is the first
By reading the count value of the counter that counts the clock pulse in the internal interrupt processing executed every time the pulse signal Vs1 is generated, the same internal interrupt processing was performed last time (when the pulse signal Vs1 was generated last time). The time (time required for the engine to make one revolution) from this time to the execution of the current internal interrupt processing is measured as a rotation speed measurement time Tn, and the rotation speed N of the engine is calculated from this time Tn.

In the main routine of the program, the microcomputer 7 calculates the ignition timing for the rotation speed N calculated in the internal interrupt processing by using a map. The ignition timing is changed, for example, with respect to the rotation speed N as shown in FIG. In FIG. 5, the ignition timing is indicated by an angle θi measured from the top dead center of the engine to the advanced side. In this example, the rotation speed N of the engine is changed from N1 to N2.
The ignition timing .theta.i is advanced from .theta.1 to .theta.2.

The ignition timing is calculated in the form of a time (ignition timing measurement time) Ti (see FIG. 2) from the second timing t2 when the pulser coil 8 generates the second pulse signal Vs2 to the ignition timing ti. In the main routine, the energization start time measurement time Ti-Ton is calculated by subtracting the energization time Ton from the ignition timing measurement time Ti. In the main routine, the calculation of the ignition timing and the calculation of the energization start timing measurement time are repeated.

The main routine implements power supply start timing / ignition timing determining means for determining the power supply start timing of the primary current of the ignition coil and the ignition timing of the internal combustion engine.

The microcomputer 7 executes an interrupt routine shown in FIG. 6 by interrupting each time an interval timer provided therein measures a predetermined time. In this interrupt routine, first, the detected voltage data PA is read in step 1, and then in step 2, the magnitude relationship between the detected voltage data PA and the data indicating the voltage Ea shown in FIG. 4 is determined. As a result, if PA ≦ Ea, the routine proceeds to step 3, sets the energizing time Ton to Ta, and returns to the main routine.

When it is determined in step 2 that PA> Ea, the process proceeds to step 4 where the detected voltage data PA is compared with the data indicating the voltage Eb in FIG. Proceeding to 5, the energization time Ton is set to Td and the process returns to the main routine. In step 4, P
If it is determined that A> Eb, the routine proceeds to step 6, where the energizing time Ton is set to Te (<Td), and the process returns to the main routine.

The microcomputer has a pulsar coil 8.
Interrupts when the second signal Vs2 is generated, sets the energization start timing measurement time Ti-Ton in the timer, and starts the measurement of the measurement time Ti-Ton.

The microcomputer also resets the timer by interrupting when the timer measures the power supply start timing measurement time Ti-Ton, and sets the power supply time Ton to the timer to start the measurement. At this time, a current supply start command is given to the ignition drive circuit 10, and a base current (ignition control signal) is given from the ignition drive circuit 10 to the transistor TR1. As a result, the transistor TR1 is turned on, and a primary current flows through the ignition coil.

When the timer measures the energization time Ton (when the ignition timing ti is measured), the microcomputer resets the timer again by interrupting the timer and gives a shutoff command to the ignition drive circuit 10. Then, the base current supplied from the ignition drive circuit 10 to the transistor TR1 is reduced to zero. Thereby, the transistor TR
Turn off 1 and cut off the primary current of the ignition coil.
The interruption of the primary current causes the secondary winding W2 of the ignition coil 1 to move.
Generates a high voltage for ignition to perform an ignition operation.

In this example, according to the voltage detected by the power supply voltage detection circuit 12, the start timing of the supply of the primary current is controlled by the interrupt routine of FIG. 6 so that the cutoff value of the primary current of the ignition coil falls within a predetermined range. Is determined.

Since the energizing time Ton is switched according to the DC power supply voltage by the interrupt routine shown in FIG. 6, it is possible to prevent the cutoff value of the primary current of the ignition coil from becoming excessive. In the above example, when the power supply voltage is equal to or lower than Ea, the primary current i1 is represented by a curve a shown by a broken line in FIG.
The energizing time of Ta becomes Ta, but the power supply voltage exceeds Ea and E
When the temperature rises to a range below b, the energization time of the primary current i1 is shortened to Td as shown by a curve b shown by a solid line in FIG.

In the above-described example, the time for energizing the primary current of the ignition coil is switched only by the power supply voltage of the DC power supply. However, the time for energizing the primary current of the ignition coil may be switched according to other conditions. it can. For example, the time rate of change dθth /
When dt exceeds the set value α (when an operation of rapidly accelerating the engine is performed), the energizing time of the primary current of the ignition coil is lengthened to increase the cutoff value in order to enhance the ignition performance. be able to. Further, the cutoff value of the primary current of the ignition coil can be switched by an external command according to the purpose of use of the engine, the use of the winding of the ignition coil, and the like. When the ignition performance is required to be increased depending on the purpose of use of the engine, for example, when switching a vehicle such as a motorcycle from a normal driving specification to a racing specification, or increasing the output of the engine for overtaking or climbing a hill. Is required.

FIG. 3 shows a hardware configuration for switching the cutoff value of the primary current of the ignition coil in accordance with the opening degree of the throttle valve and the external command as described above. The output of the throttle sensor 13 for detecting the opening of the throttle valve is converted into a digital signal by an A / D converter 7b provided in the microcomputer 7 and input to the CPU of the microcomputer. A command signal generated by an external command switch SW1 that is closed when it is necessary to extend the primary coil current for the ignition coil is input to the microcomputer 7.

FIG. 7 shows an example of an algorithm of an interrupt routine executed by the microcomputer 7 at regular intervals in accordance with a command given from the interval timer in the ignition device shown in FIG.

When the interrupt routine of FIG. 7 is started, the state of the external command switch SW1 is read in step 1 and the data PA of the detection voltage of the power supply voltage detection circuit 12 is read in step 2. Next, in step 3, the detection data of the throttle valve opening θth is read, and in step 4, the temporal change rate d of the throttle valve opening is
Calculate θth / dt. This temporal change rate is calculated by calculating a difference Δθth between the data of θth read in the interrupt routine of FIG. 7 executed last time and the data of θth read this time, and executing the difference in the interrupt routine of FIG. Calculate by dividing by the time interval. Throttle valve opening θ
If th is expressed as a percentage of the opening at full throttle and the interrupt routine of FIG. 7 is executed at intervals of, for example, 30 msec, dθth / dt = Δθth / 30
[% / Msec].

Next, at step 5, it is determined whether or not the external command switch SW1 is on. As a result, when it is determined that the external command switch SW1 is in the ON state (the state in which the command for maximizing the cutoff value of the primary current is issued), the routine proceeds to step 6, where the energizing time Ton is set.
Is set to the maximum value Ta and the process returns to the main routine.

In step 5, the external command switch SW
1 is determined to be in the off state, then in step 7 the rate of change of the throttle valve opening with time d
θth / dt is compared with the set value α, and when it is determined that dθth / dt is equal to or greater than the set value α, the routine proceeds to step 6, where the energizing time Ton of the primary current of the ignition coil is set to the maximum value Ta and the routine returns. The value of α is, for example, +50/30 [%
/ Msec]. That is, the throttle valve is 30ms
When 以上 or more of the full throttle is opened during ec, it is determined that the rapid acceleration operation has been performed, and the cutoff value of the primary current is set to the maximum value.

If it is determined in step 7 that the temporal change rate of the throttle valve opening is smaller than the set value, the process proceeds to step 8 where the detected voltage data PA and the voltage E are detected.
If PA <Ea, the routine proceeds to step 6, where the energizing time Ton is set to Ta, and the process returns to the main routine.

If it is determined in step 8 that PA ≧ Ea, then in step 9 PA and E
b, and when it is determined that PA ≦ Eb, the routine proceeds to step 10, where the energization time Ton is set to Td (<Ta), and the process returns to the main routine. In step 9, PA>
When it is determined to be Eb, the energization time Ton is set to Te in step 11 and the process returns to the main routine.

The algorithm for controlling the timing of starting the application of the primary current of the ignition coil according to the output of the throttle sensor and the state of the external command switch is not limited to the above example. For example, in the example shown in FIG. 7, when the external command switch SW1 is in the ON state, the energization time is controlled to be maximum. However, the temporal change rate of the throttle valve opening is equal to or more than the set value α. The primary current conduction time at
It is also possible to control so that the energizing time of the primary current when the temporal change rate of the opening degree of the throttle valve is less than the set value α differs between when the external command switch is on and when it is off. . Further, the primary current energizing time may be switched only in accordance with the state of the external command switch without providing a throttle sensor, and the primary current energizing time is switched only in accordance with the temporal change rate of the throttle sensor output. You may do so.

In the above description, the energizing time of the primary current is switched in a stepwise manner. However, the energizing time Ton is continuously changed for various control conditions by performing an interpolation calculation using a map for calculating the energizing time. It can also be made to change dynamically.

[0053]

As described above, according to the present invention, the start time of the primary current supply of the ignition coil is controlled in accordance with the output voltage of the DC power supply, so that the cutoff value of the primary current falls within a predetermined range. With this configuration, it is possible to prevent the cutoff value of the primary current from becoming excessive when the power supply voltage rises, thereby preventing the secondary induced voltage of the ignition coil from becoming excessive.

Also, according to the present invention, since the energization start timing is controlled in accordance with the power supply voltage so that the cutoff value of the primary current falls within a predetermined range, the time for energizing the primary current is required when the power supply voltage rises. It is possible to prevent the heat generation from becoming longer as described above, reduce the loss that occurs in the primary winding of the ignition coil and the primary current control switch, and prevent generation of a large amount of heat in these portions.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration example of hardware of an ignition device for an internal combustion engine according to the present invention.

FIG. 2 is a diagram showing an example of a waveform of an output signal of a pulsar coil used in the ignition device of FIG. 1 and a waveform of a primary current of the ignition coil.

FIG. 3 is a circuit diagram showing another example of the configuration of the ignition device for an internal combustion engine according to the present invention.

FIG. 4 is a diagram showing a temporal change of a primary current of an ignition coil with an applied voltage as a parameter.

FIG. 5 is a diagram showing an example of an ignition characteristic obtained by an internal combustion engine ignition device according to a modified invention.

FIG. 6 is a flowchart showing an example of an algorithm of a program executed by the microcomputer of the ignition device of FIG. 1 at regular time intervals.

7 is a flowchart showing another example of the algorithm of the program executed by the microcomputer of the ignition device of FIG. 3 at regular time intervals.

FIG. 8 is a circuit diagram showing a configuration of a conventional ignition device for an internal combustion engine.

9 is a diagram showing waveforms of an output signal of a pulsar coil used in the ignition device of FIG. 8 and a primary current of the ignition coil.

[Explanation of symbols]

1: ignition coil, W1: primary winding, W2: secondary winding, 2
... Ignition plug, 3 ... Primary current control switch, 4 ... Battery, 5 ... Switch, 6 ... Ignition control device, 7 ... Microcomputer, 8 ... Pulsar coil, 10 ... Ignition drive circuit, 12 ... Power supply voltage detection circuit, 13 ... Throttle sensor, SW1 ... external command switch.

Claims (4)

[Claims] An ignition coil having a secondary winding connected to an ignition plug attached to a cylinder of an internal combustion engine; a DC power supply for supplying a primary current to a primary winding of the ignition coil; A primary current control switch for controlling the primary current of the ignition coil to be turned on and off, and a power supply start timing determined by determining a power supply start time of the primary current of the ignition coil and an ignition timing of the internal combustion engine. An ignition control device that starts supplying a primary current to an ignition coil and that supplies the control signal to the primary current control switch so as to cut off the primary current when the determined ignition timing is detected. In the ignition device, a power supply voltage detection circuit for detecting an output voltage of the DC power supply is provided, and the ignition control device includes a cutoff value of a primary current of the ignition coil or the primary current. To keep the voltage induced in the secondary winding of the ignition coil to a predetermined range when blocked,
An ignition device for an internal combustion engine, which is configured to determine an energization start time of the primary current according to a voltage detected by the power supply voltage detection circuit. 2. An ignition coil having a secondary winding connected to an ignition plug mounted on a cylinder of an internal combustion engine; a DC power supply for supplying a primary current to a primary winding of the ignition coil; A primary current control switch for controlling the primary current of the ignition coil to be turned on and off, and a power supply start timing determined by determining a power supply start time of the primary current of the ignition coil and an ignition timing of the internal combustion engine. An ignition control device that starts supplying a primary current to an ignition coil and that supplies the control signal to the primary current control switch so as to cut off the primary current when the determined ignition timing is detected. In the ignition device, a power supply voltage detection circuit for detecting an output voltage of the DC power supply, and a cutoff value of a primary current of the ignition coil or the ignition coil when the primary current is cut off. At least one sensor for detecting a control condition used for determining a magnitude of a voltage induced in the secondary winding; and the ignition control device includes a cutoff value of a primary current of the ignition coil or the primary current. The control condition detected by the sensor and the power supply voltage detection circuit are set so that the voltage induced in the secondary winding of the ignition coil when the power supply is cut off has a value determined according to the control condition detected by the sensor. An ignition device for an internal combustion engine, which is configured to determine an energization start timing of the primary current in accordance with a voltage detected by the ignition device. 3. An ignition coil having a secondary winding connected to an ignition plug mounted on a cylinder of an internal combustion engine, a DC power supply for supplying a primary current to a primary winding of the ignition coil, and a control signal responsive to a control signal. A primary current control switch for controlling the primary current of the ignition coil to be turned on and off, and a power supply start timing determined by determining a power supply start time of the primary current of the ignition coil and an ignition timing of the internal combustion engine. An ignition control device that starts supplying a primary current to an ignition coil and that supplies the control signal to the primary current control switch so as to cut off the primary current when the determined ignition timing is detected. In the ignition device, a power supply voltage detection circuit for detecting an output voltage of the DC power supply, and a cutoff value of a primary current of the ignition coil or the ignition coil when the primary current is cut off. At least one external command switch for instructing the magnitude of the voltage induced in the secondary winding, wherein the ignition control device is configured to interrupt the primary current of the ignition coil or the primary current when the primary current is interrupted. In order to set the voltage induced in the secondary winding of the ignition coil to the magnitude specified by the external command switch, the primary current is changed according to the state of the external command switch and the voltage detected by the power supply voltage detection circuit. An ignition device for an internal combustion engine configured to determine an energization start timing. 4. An ignition coil having a secondary winding connected to an ignition plug attached to a cylinder of an internal combustion engine, a DC power supply for supplying a primary current to a primary winding of the ignition coil, and a control signal responsive to a control signal. A primary current control switch for controlling the primary current of the ignition coil to be turned on and off, and a power supply start timing determined by determining a power supply start time of the primary current of the ignition coil and an ignition timing of the internal combustion engine. An ignition control device that starts supplying a primary current to an ignition coil and that supplies the control signal to the primary current control switch so as to cut off the primary current when the determined ignition timing is detected. In the ignition device, a power supply voltage detection circuit for detecting an output voltage of the DC power supply, and a cutoff value of a primary current of the ignition coil or the ignition coil when the primary current is cut off. At least one sensor for detecting a control condition used to determine the magnitude of a voltage induced in the secondary winding; and a cutoff value of a primary current of the ignition coil or an induced voltage of a secondary winding of the ignition coil. At least one external command switch for indicating a magnitude is provided, wherein the ignition control device is configured to generate a cut-off value of a primary current of the ignition coil or a secondary winding of the ignition coil when the primary current is cut off. The control condition detected by the sensor, the state of the external command switch, the power supply voltage detection circuit, and the control signal detected by the sensor are set to a magnitude determined by the control condition detected by the sensor and an instruction given by the external command switch. An ignition device for an internal combustion engine, which is configured to determine an energization start timing of the primary current in accordance with a voltage detected by the ignition device.