JP2002250264A - Ignition device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition device for an internal combustion engine capable of using a common current-carrying map at the time of failure and at other normal times. SOLUTION: The ignition device has a fail-safe function and can be retracted by operating an ignition coil 12 with the energy of a battery 10 through a bypass for the ignition current carrying passage leading to the engine stop at the time of failure. The coil constant of an energy accumulating coil 11 and the primary coil 14 is set so that the value of the carried current in the energy accumulating coil 11 and the primary coil 14 is a prescribed constant value in a prescribed period of time elapsed after transistors Q1 and Q2 are on. Therefore, by relating the coil constant of the resistance and inductance of the energy accumulating coil 11 and the primary coil 14 with each other, the current-carrying map can be used in common at the time of failure and at other normal times, and the scale of operation can be reduced with a simple structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device for an internal combustion engine (hereinafter, an "internal combustion engine" is referred to as an engine).

[0002]

2. Description of the Related Art Hitherto, there has been known a multiple discharge type engine ignition device in which a capacity discharge type ignition device and an induction discharge type ignition device are combined to perform a multiple discharge at an ignition discharge timing.

As this type of ignition device, for example, Japanese Patent Laid-Open
In the ignition device disclosed in JP-A-15659, at the ignition timing, the energy stored in the energy storage coil and the energy charged in the capacitor for capacitive discharge are supplied to the ignition coil, and the spark plug generates a spark. .
Further, energy is periodically supplied to the ignition plug by the energy storage coil in a predetermined discharge section from the timing at which ignition is started, so that multiple discharges are performed and the spark is maintained. In such a multiple discharge type engine ignition device,
Discharge interruption is less likely to occur than a single discharge type ignition device.

[0004]

By the way, it is required that ignition be performed even in the event of a failure such as a component failure or an abnormality in wiring to enable limp-home travel. It is conceivable to supply energy from the DC power supply to the primary coil of the ignition coil. However, in this case, it is necessary to newly prepare a DC power supply, and there is a need for improvement in terms of parts cost, installation space, and maintenance.

Therefore, a bypass path from a DC power supply is provided in parallel with the ignition coil energizing path leading to the engine stop at the time of a failure, and the evacuation traveling is enabled by switching from the multiple discharge method to the single discharge method at the time of the failure. (Japanese Patent Application No. 2000-324393).

Here, in the ignition device for an engine provided with the above-mentioned bypass path, an ignition signal which rises to a high level at a predetermined angle (for example, 30 ° CA) before the ignition timing and falls at the ignition timing at normal times other than the time of a failure. It is conceivable that the energizing time of the energy storage coil is determined during the high level period, and the primary coil of the ignition coil is energized using the same ignition signal even in the event of a failure.

However, if the same ignition signal is used at the time of a failure and at the time of the other normal times, as long as the energy storage coil and the primary coil are designed independently, the rise time at the time of energization of both the energy storage coil and the primary coil is Therefore, it is necessary to have an energization map separately from the normal time other than the time of the failure so that a predetermined current can flow through the primary coil at the time of the failure. For this reason, there has been a problem that the logic configuration of the electronic control unit is complicated and the operation scale is increased.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an ignition device for an engine that enables a common use of an energization map at the time of a failure and at other times. I do. Another object of the present invention is to provide an ignition device for an engine, which can reduce the operation scale with a simple logic configuration.

[0009]

According to the ignition device for an engine of the present invention, the first switching element is turned on / off by the first switching element control means and stored in the energy storage coil. The capacitor for discharging the capacity is charged by the energy, and the second switching element is turned on / off at the ignition timing, and the energy charged in the capacitor for discharging the capacity is charged to the ignition coil.
It is supplied to the next coil. For this reason, the energy stored in the first and second capacitors for capacitive discharge at the previous ignition timing and the energy stored in the energy storage coil are supplied to the primary coil of the ignition coil,
A high voltage for ignition is applied to the secondary coil, and the spark plug generates a spark.

[0010] Further, the first and second switching elements are alternately turned on and off in a predetermined discharge period thereafter to perform multiple discharges, so that ignition energy is supplied periodically during the discharge period and the spark of the spark plug is maintained. I do. Further, at the time of a failure, the second switching element is turned on / off by the second switching element control means at the ignition timing, and the energy of the DC power supply is supplied to the primary coil of the ignition coil via the second backflow prevention means. Since it is supplied, it is possible to perform evacuation traveling. Therefore, it is possible to perform ignition using one DC power supply at the time of a failure and at other normal times, and it is possible to easily provide an engine ignition device having a fail-safe function.

Furthermore, the second backflow prevention means
The energy charged in the capacitance discharging capacitor is prevented from flowing back to the DC power supply side in a normal time other than the time of a failure. Furthermore, the conduction of the energy storage coil by the first switching element and the conduction of the primary coil by the second switching element via the second backflow prevention means at the time of a failure are the same as those of the target after a predetermined period. Since the coil constants are set so as to be the energizing current values, the energizing maps during the failure and other normal times are shared by relating the coil constants of the resistance and inductance of the energy storage coil and the primary coil. It can be used, and the operation scale can be reduced with a simple logic configuration.

[0012] According to the engine ignition device of the second aspect of the present invention, the first switching element control means provides:
The first switching element is turned on / off to charge the capacitor for discharging capacity with the energy stored in the energy storage coil, and the second switching element is turned on / off for charging the capacitor for discharging capacity at the ignition timing. Energy is supplied to the primary coil of the ignition coil. Therefore, the energy stored in the first and second capacitors for capacitive discharge at the previous ignition timing and the energy stored in the energy storage coil are supplied to the primary coil of the ignition coil and the secondary coil Is applied with a high voltage for ignition, and the spark plug generates a spark.

Further, the first and second switching elements are alternately turned on and off in a predetermined discharge period thereafter to perform multiple discharges, so that ignition energy is supplied periodically during the discharge period and the spark of the spark plug is maintained. I do. Further, at the time of a failure, the second switching element is turned on / off by the second switching element control means at the ignition timing, and the energy of the DC power supply is supplied to the primary coil of the ignition coil via the second backflow prevention means. Since it is supplied, it is possible to perform evacuation traveling. Therefore, it is possible to perform ignition using one DC power supply at the time of a failure and at other normal times, and it is possible to easily provide an engine ignition device having a fail-safe function.

Further, the second backflow prevention means
The energy charged in the capacitance discharging capacitor is prevented from flowing back to the DC power supply side in a normal time other than the time of a failure. Furthermore, the voltage setting means allows conduction of the energy storage coil by the first switching element and the secondary coil of the primary coil via the second backflow prevention means at the time of failure.
The voltage of the DC power supply is set so that the conduction by the switching element becomes the respective target energized current value after the lapse of the same predetermined period, so that the resistance and inductance of the energy storage coil and the primary coil are adjusted to the respective coil constants. By lowering the voltage of the DC power supply at the time of the failure or at the time of the other normal times by the voltage setting means, it is possible to commonly use the energization map at the time of the failure and at the time of the other normal times. With the configuration, the operation scale can be reduced.

According to the ignition device for an engine according to the third aspect of the present invention, the first switching element control means provides:
The first switching element is turned on / off to charge the capacitor for discharging capacity with the energy stored in the energy storage coil, and the second switching element is turned on / off for charging the capacitor for discharging capacity at the ignition timing. Energy is supplied to the primary coil of the ignition coil. Therefore, the energy stored in the first and second capacitors for capacitive discharge at the previous ignition timing and the energy stored in the energy storage coil are supplied to the primary coil of the ignition coil and the secondary coil Is applied with a high voltage for ignition, and the spark plug generates a spark.

Further, during the predetermined discharge period, the first and second switching elements are alternately turned on and off to perform multiple discharges, so that ignition energy is supplied periodically during the discharge period and the spark of the spark plug is maintained. I do. Further, at the time of a failure, the second switching element is turned on / off at the ignition timing by the second switching element control means, and the energy of the DC power supply is transferred to the ignition coil through the first and second backflow prevention means. Since it is supplied to the next coil, it is possible to perform a limp-home run. Therefore,
It is possible to perform ignition using one DC power supply at the time of a failure and at other normal times, and it is possible to easily provide an engine ignition device having a fail-safe function.

Furthermore, the second backflow prevention means
The energy charged in the capacitance discharging capacitor is prevented from flowing back to the DC power supply side in a normal time other than the time of a failure. Furthermore, the conduction of the energy storage coil by the first switching element and the conduction of the primary coil by the second switching element via the second backflow prevention means at the time of a failure are the same as those of the target after a predetermined period. Since the coil constants are set so as to be the energizing current values, the energizing maps during the failure and other normal times are shared by relating the coil constants of the resistance and inductance of the energy storage coil and the primary coil. It can be used, and the operation scale can be reduced with a simple logic configuration.

According to the ignition device for an engine according to the fourth aspect of the present invention, the first switching element control means provides:
The first switching element is turned on / off to charge the capacitor for discharging capacity with the energy stored in the energy storage coil, and the second switching element is turned on / off for charging the capacitor for discharging capacity at the ignition timing. Energy is supplied to the primary coil of the ignition coil. Therefore, the energy stored in the first and second capacitors for capacitive discharge at the previous ignition timing and the energy stored in the energy storage coil are supplied to the primary coil of the ignition coil and the secondary coil Is applied with a high voltage for ignition, and the spark plug generates a spark.

Further, the first and second switching elements are alternately intermittently turned on and off in a predetermined discharge period to perform multiple discharges, so that ignition energy is supplied periodically during the discharge period and the spark of the spark plug is maintained. I do. Further, at the time of a failure, the second switching element is turned on / off at the ignition timing by the second switching element control means, and the energy of the DC power supply is transferred to the ignition coil through the first and second backflow prevention means. Since it is supplied to the next coil, it is possible to perform a limp-home run. Therefore,
It is possible to perform ignition using one DC power supply at the time of a failure and at other normal times, and it is possible to easily provide an engine ignition device having a fail-safe function.

Further, the second backflow prevention means
The energy charged in the capacitance discharging capacitor is prevented from flowing back to the DC power supply side in a normal time other than the time of a failure. Furthermore, the voltage setting means allows conduction of the energy storage coil by the first switching element and the secondary coil of the primary coil via the second backflow prevention means at the time of failure.
The voltage of the DC power supply is set so that the conduction by the switching element becomes the respective target energized current value after the lapse of the same predetermined period, so that the resistance and inductance of the energy storage coil and the primary coil are adjusted to the respective coil constants. By lowering the voltage of the DC power supply at the time of the failure or at the time of the other normal times by the voltage setting means, it is possible to commonly use the energization map at the time of the failure and at the time of the other normal times. With the configuration, the operation scale can be reduced.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; (First Embodiment) FIG. 1 shows an electrical configuration of an engine ignition device according to a first embodiment of the present invention. The ignition device of the first embodiment is mounted on a vehicle, and is provided with a DLI (Distribution).
This is a tor less ignition system.

In FIG. 1, an energy storage coil 11 and a transistor Q1 are connected in series between a plus terminal of a battery 10 and a ground. Battery 10 is 1
It is a 2-volt specification. Energy is stored in the energy storage coil 11 by energization when the transistor Q1 is turned on. At this time, the current flowing through the energy storage coil 11 and i _0. The point a between the energy storage coil 11 and the transistor Q1 is connected via a diode D1 to a capacitor 12 as a capacitor for discharging capacity.
The capacitor 12 is charged by the energy stored in the energy storage coil 11.

A first cylinder ignition coil 1 is provided between point b between the diode D1 and the capacitor 12 and the ground.
3, a primary coil 14, a transistor Q11, and a current detection resistor 16 are connected in series. Then, the energy charged in the capacitor 12 by turning on / off the transistor Q11 can be supplied to the primary coil 14 of the ignition coil 13. At this time, the current (primary current) flowing through the primary coil 14 is defined as i ₁ . Ignition coil 13-2
A first cylinder ignition plug (not shown) is connected to the next coil 15. A current (secondary current) i ₂ flows through the secondary coil 15 with the energization of the primary coil 14.

Similarly, the primary coil 18 of the second cylinder ignition coil 17, the transistor Q12, and the current detecting resistor 20 are connected in series between the point b and the ground. A secondary cylinder spark plug (not shown) is connected to the secondary coil 19 of the ignition coil 17.

In FIG. 1, the ignition coil 17 for the second cylinder, the transistor Q12 and the current detecting resistor 20 are used.
However, ignition coils, transistors, and resistors for the number of engine cylinders are provided. Further, a reflux diode Dfh is connected in parallel to the above-mentioned capacitor 12, and the current flowing through the primary coil 14 (18) when the transistor Q11 (Q12) is off is returned via the diode Dfh. Further, a transistor Q21 and a diode D2 are connected in series between the point c between the battery 10 and the energy storage coil 11 and the point b.

On the other hand, an electronic control unit (ECU;
The onic control unit (21) can receive signals from various sensors and detect the state of the engine (intake air amount, rotation speed, cooling water temperature, etc.). Then, the ECU 21 determines an optimum ignition timing according to the engine state at that time. Further, a drive circuit 22 is connected to the ECU 21, and the ECU 21 outputs a cylinder discrimination signal IGt and a discharge section signal IGw to the drive circuit 22. The driving circuit 22 includes the transistors Q1, Q11, Q
12 and Q21 are connected, a drive signal A is output to the transistor Q1, a first cylinder drive signal B # 1 is output to the transistor Q11, and a second cylinder drive signal B # 2 is output to the transistor Q12. The switching drive signal SG1 is output to Q21.

The ECU 21 also includes a resistor 16 for detecting current.
And the applied voltage between both terminals (voltage at the α1 point) is monitored. Similarly, the ECU 21 monitors the applied voltage (the voltage at the point α2) between the two terminals of the current detection resistor 20 corresponding to the cylinders other than the first cylinder. The voltage applied between both terminals of the current detection resistors 16 and 20 is the primary current i
_The ECU 21 determines that a failure has occurred if a situation in which the monitor voltage (primary current i ₁ ) does not reach the predetermined value during the ignition operation occurs continuously for a predetermined number of times.

As described above, the battery 1 as a DC power supply
0, an energy storage coil 11, and a first series circuit including a transistor Q1 as a first switching element.
The capacitor 12 is connected via a diode D1 as a backflow preventing means, and the capacitor 12, the primary coil 14 (18) of the ignition coil 13 (17), and the transistor Q11 (Q12) as a second switching element.
And a series circuit including the battery 10, the energy storage coil 11, the diode D1, the primary coil 14 (18) of the ignition coil 13 (17), and the transistor Q11 (Q12). A diode D2 as a second backflow prevention means is connected in parallel to the energy storage coil 11 and the diode D1 in the circuit. A transistor Q21 is provided in the middle of the parallel circuit including the diode D2.

Next, the operation of the ignition device configured as described above will be described with reference to FIGS. FIG. 2 shows each signal waveform and current waveform in a normal state other than the time of a failure. That is, the drive signal SG1 of the transistor Q21, the discharge section signal IGw, and the cylinder discrimination signal IGt
And the drive signal A of the transistor Q1 and the transistor Q1
11 shows a drive signal B # 1, a current i ₀ flowing through the energy storage coil 11, a primary current i ₁ of the ignition coil 13, and a secondary current i ₂ .

At a normal time other than the time of a failure, the drive circuit 22 sets the signal SG1 to L level and sets the transistor Q21
Is turned off. Further, a cylinder discrimination signal IGt is output from the ECU 21 to the drive circuit 22, and the signal IGt is outputted.
t is at the H level during the period from t1 to t2 in FIG.
The drive circuit 22 outputs a drive signal A having a waveform synchronized with the signal IGt to the transistor Q1. The signal A turns on the transistor Q1 to gradually increase the current i ₀ , and the high voltage energy generated in the energy storage coil 11 when the transistor Q1 is off turns off the diode D1.
To the primary coil 14 of the ignition coil 13. This period is defined as a.

On the other hand, the discharge interval signal IGw corresponds to t2 to t2 in FIG.
It is at the H level during the period of t3, and discharge is performed during this period. Specifically, the drive circuit 22 outputs a signal (a signal inverted at the timing of t11, t12,...) Inverted every predetermined time as the drive signal A to the transistor Q1, and outputs the high-voltage energy generated in the energy storage coil 11 when the transistor is turned off. Is stored in the capacitor 12 via the diode D1 (so-called multiple charging). During this repetitive operation, the drive circuit 22 outputs a signal complementary to the drive signal A (a signal inverted at the timing of t2, t11, t12,...) To the transistor Q11 as the drive signal B # 1. The signal B # 1, the energy of the capacitor 12 is supplied to the primary coil 14 of the ignition coil 13, when interruption of the primary current i ₁ (t11 in FIG. 2, t13, t15, t
17), a large secondary current i ₂ (high voltage) is generated, and multiple ignition is performed. Then, for the next ignition, the transistor Q1 turns on at the timing t17 and turns off at the timing t18,
The energy generated in the energy storage coil 11 during the period from t17 to t18 is stored in the capacitor 12. That is, when the transistor Q11 is turned on during the period from t2 to t11 in the operation for the current ignition, t17 to t17
Capacitor 1 during period 18 (operation for previous ignition)
2 and the energy generated in the energy storage coil 11 during the period from t1 to t2 are supplied to the primary coil 14. That is, in the primary current i ₁ in the period t2~t11 in Figure 2, the projecting current portion e1 of charge is energy stored in the capacitor 12, then the energy gentle current portion e2 during the t1~t2 storage coil 11 Energy generated by

The same operation is performed in other cylinders than the first cylinder. That is, in the drive circuit 22, the cylinder is determined by the cylinder determination signal IGt, and the transistor Q11
The drive signal B # 2 and the like are output to the transistor Q12 and the like in place of, and multiple charging and multiple ignition are performed.

As described above, the drive circuit 22 as the first switching element control means turns on / off (conducts / cuts off) the transistor Q1 and charges the capacitor 12 with the energy stored in the energy storage coil 11. At the ignition timing, the transistor (Q11 and the like) is turned on / off to supply the energy charged in the capacitor 12 to the primary coil (14 and the like) of the ignition coil (13 and the like), whereby the ignition operation is performed. Specifically, the drive circuit 22 includes a cylinder discrimination signal IGt and a discharge section signal IGw.
, The transistor Q1 is continuously turned on / off in a predetermined discharge section with respect to the target cylinder to multiply charge the capacitor 12, and the transistor (Q11
) Is operated in a complementary manner to the transistor Q1 to perform multiple ignition.

FIG. 3 shows each signal waveform and current waveform at the time of a failure. When the ECU 21 detects that a failure has occurred in the voltage monitor using the current detection resistors 16 and 20, the ECU 21 switches from the normal mode to the fail-safe mode. In the fail-safe mode, first, the ECU 21 sets the drive signal SG1 to the H level at the timing of t20 in FIG.
1 is turned on, and as a signal to the drive circuit 22, the output level of the discharge section signal IGw is switched from the maximum 5 volts to 12 volts. Drive circuit 22
Monitors the voltage of the input port (indicated by P1 in FIG. 1) of the discharge section signal IGw, and when the voltage is switched to 12 volts, it is determined that the mode is the fail-safe mode, and the cylinder discrimination signal IGt is distributed to each cylinder. B # 1 and B # 2
Output as The transistors Q11 and Q12 are turned on / off by the signals B # 1 and B # 2.
That is, in the first cylinder, the transistor Q11 is turned on at the timing of t21 in FIG. 3, and is turned off at the timing of t22. During on of the transistors Q11, to the primary coil 14 of the ignition coil 13 from a battery 10 is supplied energy via the diode D2, when interruption of the primary current i ₁ of the ignition coil 13 (t in Fig. 3
At timing 22), a large secondary current i ₂ (high voltage) is generated and used for ignition. This period is defined as b. Similarly, for the second cylinder, for example, the transistor Q12 is turned on at the timing of t23 in FIG. 3 and turned off at the timing of t24, and ignition is performed.

As described above, when a failure such as a failure of the energy storage coil 11, the transistor Q1, the diode D1, or the capacitor 12 or an abnormality in the wiring of these components occurs, the drive as the second switching element control means is performed. The circuit 22 turns on / off (conducts / cuts off) the transistor Q11 (Q12) at the ignition timing.
The energy of the battery 10 is transferred to the primary coil 14 (18) of the ignition coil 13 (17) via the diode D2.
To supply. Thereby, it is possible to perform the limp-home running. At this time, since the coil constants of the resistance and the inductance of the energy storage coil 11 and the primary coil 14 (18) are associated with each other, the same energization map as in the normal state can be used at the time of a failure. In addition, the diode D2 prevents the energy charged in the capacitor 12 from flowing back to the battery 10 during normal times other than the time of failure.

In the first embodiment described above, the ignition coil 1 is turned on by the energy of the battery 10 by using the bypass path for the ignition energizing path leading to the engine stop at the time of failure.
By activating 3 (17), limp-home traveling can be performed. As a result, the ignition using one battery 10 can be performed at the time of the failure and at the time of the other normal times, and an ignition device having a fail-safe function with a simpler configuration can be provided.

In particular, the drive circuit 22 switches the transistor Q21 from the previously cut-off state to the conductive state at the time of a failure.
(17) The energy supply path to the primary coil 14 (18) can be reliably shut off. Further, the normal period a of the energy storage coil 11 and the primary coil 14
The currents i _0a and i _1b flowing in the period b in the fail-safe mode can be expressed by the following equations.

I _0a = V ₀ / R ₀ [1-exp (−R ₀ / L ₀ × t)] (1) i _1b = V ₁ / R ₁ [1-exp (−R ₁ / L ₁ × t)] (2) where V ₀ , R ₀ and L ₀ are the energy storage coils 11
Voltage applied to a resistance and inductance of the energy storage coil 11, V _1, R ₁ and L ₁ is a voltage applied to the primary coil 14, the resistance and inductance of the primary coil 14. Also, t is the energization time of the energy storage coil 11 and the primary coil 14. In the first embodiment, as shown in Expressions (1) and (2), since the rising time of the energy storage coil 11 and the primary coil 14 when the current is applied is different, the energization of each coil (11 and 14) is performed. When the same time elapses from the time, the resistances (R ₀ , R ₁ ) and the inductances (L ₀ , L ₀ ,
L ₁ ) is set. Therefore, by relating each coil constant of the resistance and the inductance of the energy storage coil 11 and the primary coil (14 etc.),
The energization maps at the time of failure and at other times can be commonly used, and the calculation scale can be reduced with a simple logic configuration.

Further, the drive circuit 22 receives the cylinder discrimination signal IGt at the time of a failure and turns on / off the transistor Q11 (Q12) in synchronization with the cylinder discrimination signal IGt. Transistor Q11 (Q
12) can be controlled.

Furthermore, since the mode switching coasting information is transmitted by switching the signal level of the discharge section signal IGw which is not used in the fail-safe mode, the signal which is not used in the fail-safe mode is effectively utilized. Mode switching information can be transmitted.

In the first embodiment, the current supplied to the energy storage coil 11 and the primary coil (14 and the like) after a lapse of a predetermined period from the conduction of the transistor Q1 and the transistor (Q11 and the like) becomes equal to the predetermined constant value. In the present invention, the coil constant is set so as to satisfy the resistance or inductance of the energy storage coil 11 and the primary coil (14 or the like) at the time of a failure or any other normal time. Battery 1
The voltage of 0 can be reduced by voltage setting means such as a diode and a transistor. As a result, the energization maps at the time of failure and at other times can be commonly used, and the circuit scale can be reduced with a simple configuration. Although the transistor Q21 and the diode D2 are provided on the bypass path in the first embodiment shown in FIG. 1, only the diode D2 may be provided in the present invention.

(Second Embodiment) A second embodiment is shown in FIG.
The same components as those in the first embodiment shown in FIG. In the second embodiment, as shown in FIG.
A diode D20 as a second backflow prevention means and a transistor Q210 are connected in parallel to the energy storage coil 11, and the drive circuit 22 turns on / off the transistor Q11 at the ignition timing at the time of a failure, thereby enabling the energy of the battery 10 to be discharged. D1 and D20
To the primary coil 14 (18) of the ignition coil. In this case, the energy storage coil 1 is not operated by the diode D20 at the time of normal operation other than failure.
1 is prevented from flowing back to the battery 10 side.

In the second embodiment, the same effects as in the first embodiment shown in FIG. 1 can be obtained. The second
In the embodiment, when the diode D1 fails, the failure cannot be dealt with as compared with the first embodiment shown in FIG. 1. Therefore, a countermeasure such as increasing the withstand voltage as the diode D1 of the second embodiment shown in FIG. It is desirable to take this.

The transistor Q2 provided in the middle of the parallel circuit including the diode D20 of the second embodiment shown in FIG.
In the event of a failure, the drive circuit 10 switches from the previously cut off state to the conducting state. This allows the ignition coil 13 (1) from the battery 10 via the diodes D1 and D20 during normal times other than a failure.
7) The energy supply path to the primary coil 14 (18) can be reliably shut off.

In the second embodiment, as in the first embodiment, the energy storage coil 11 and the primary coil (1
The voltage of the battery 10 at the time of a failure or at other normal times can be reduced by voltage setting means such as a diode in accordance with the coil constants of the resistance and the inductance of 4). As a result, the energization maps at the time of failure and at other times can be commonly used, and the circuit scale can be reduced with a simple configuration. In the second embodiment, the transistor Q210 and the diode D20 are connected to the bypass path.
However, in the present invention, only the diode D20 may be provided.

The transistors Q1, Q11, Q12, Q21 and Q21 in the plural embodiments of the present invention described above.
As 0, any of a bipolar transistor, an FET (preferably a P-channel MOSFET), and an IGBT may be used, and any switching element may be used. Further, in the first and second embodiments, the case where the failure is detected by monitoring the primary current i ₁ using the resistors 16 and 20 has been described. It is needless to say that a method for performing such operations may be used.

[Brief description of the drawings]

FIG. 1 is an electrical configuration diagram showing an engine ignition device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing signal waveforms and current waveforms of the engine ignition device according to the first embodiment of the present invention in a normal state.

FIG. 3 is a diagram showing signal waveforms and current waveforms when the engine ignition device according to the first embodiment of the present invention fails.

FIG. 4 is an electrical configuration diagram showing an engine ignition device according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Battery (DC power supply) 11 Energy storage coil 12 Capacitor (capacitor for capacity discharge) 13, 17 Ignition coil 14, 18 Primary coil 15, 19 Secondary coil 16, 20 Current detection resistor 21 ECU 22 Drive circuit (1st Switching element control means,
Second switching element control means) Q1 transistor (first switching element) Q11, Q12 transistor (second switching element) Q21, Q210 transistor D1 diode (first backflow prevention means) D2, D20 diode (second switching element) Backflow prevention means) IGt cylinder discrimination signal IGW discharge interrogation signal

Claims (4)

[Claims] 1. A first series circuit including a DC power supply, an energy storage coil, and a first switching element; a capacitor for capacitive discharge connected to the energy storage coil via first backflow prevention means; and an ignition coil. A second series circuit including a primary coil and a second switching element, and conducting / cutting off the first switching element to charge the capacitor for discharging capacitance with the energy stored in the energy storage coil. The second
First switching element control means for conducting / blocking the switching element to supply the energy charged in the capacitor for capacitor discharge to the primary coil; the DC power supply; the energy storage coil; Backflow prevention means, a second backflow prevention means connected in parallel to the energy storage coil and the first backflow prevention means in a series circuit including the primary coil and the second switching element, Second switching element control means for conducting / interrupting the second switching element at ignition timing to supply the energy of the DC power supply to the primary coil via the second backflow prevention means. Means for conducting the energy storage coil by the first switching element and the second backflow prevention means at the time of a failure; Wherein the coil constant is set so that the conduction of the primary coil through the second switching element becomes the target current value after a lapse of the same predetermined period. apparatus. 2. A first series circuit including a DC power supply, an energy storage coil, and a first switching element; a capacitor for capacitive discharge connected to the energy storage coil via first backflow prevention means; and an ignition coil. A second series circuit including a primary coil and a second switching element, and conducting / cutting off the first switching element to charge the capacitor for discharging capacitance with the energy stored in the energy storage coil. The second
First switching element control means for conducting / blocking the switching element to supply the energy charged in the capacitor for capacitor discharge to the primary coil; the DC power supply; the energy storage coil; Backflow prevention means, a second backflow prevention means connected in parallel to the energy storage coil and the first backflow prevention means in a series circuit including the primary coil and the second switching element, A second switching element control means for conducting / interrupting the second switching element at ignition timing to supply energy of the DC power supply to the primary coil via the second backflow prevention means; The conduction of the energy storage coil by the first switching element and the failure of the energy storage coil via the second backflow prevention means during a failure. Voltage setting means for setting a voltage of the DC power supply such that conduction of the primary coil by the second switching element becomes each target energized current value after a lapse of a predetermined period. Ignition device for an internal combustion engine. 3. A first series circuit including a DC power supply, an energy storage coil, and a first switching element; a capacitor for capacitive discharge connected to the energy storage coil via first backflow prevention means; and an ignition coil. A second series circuit including a primary coil and a second switching element, and conducting / cutting off the first switching element to charge the capacitor for discharging capacitance with the energy stored in the energy storage coil. The second
First switching element control means for conducting / blocking the switching element to supply the energy charged in the capacitor for capacitor discharge to the primary coil; and a first switching element control means connected in parallel to the energy storage coil. Backflow prevention means, and the second switching element is turned on / off at an ignition timing at the time of a failure to supply the energy of the DC power supply to the primary coil via the first and second backflow prevention means. Switching means for controlling the conduction of the energy storage coil by the first switching element and the second switching of the primary coil via the second backflow prevention means in the event of a failure. The coil constant is set so that conduction by the element becomes each target energized current value after the same predetermined fixed period elapses. Preparative ignition apparatus according to claim. 4. A first series circuit including a DC power supply, an energy storage coil, and a first switching element; a capacitor for capacitive discharge connected to the energy storage coil via first backflow prevention means; and an ignition coil. A second series circuit including a primary coil and a second switching element, and conducting / cutting off the first switching element to charge the capacitor for discharging capacitance with the energy stored in the energy storage coil. The second
First switching element control means for conducting / blocking the switching element to supply the energy charged in the capacitor for capacitor discharge to the primary coil; and a first switching element control means connected in parallel to the energy storage coil. Backflow prevention means, and the second switching element is turned on / off at an ignition timing at the time of a failure to supply the energy of the DC power supply to the primary coil via the first and second backflow prevention means. Switching element control means, for conducting the energy storage coil by the first switching element, and by the second switching element of the primary coil via the second backflow prevention means at the time of a failure. A voltage that sets the voltage of the DC power supply so that conduction becomes the respective target energized current value after the same predetermined period has elapsed. Ignition system for an internal combustion engine, characterized in that it comprises a constant means.