JP2002250263A - Ignition device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition device for an internal combustion engine for easily securing the performance of a capacity discharging capacitor even if the capacitor is short-circuited. SOLUTION: The energy accumulated in the capacitors 12 and 32 at the previous ignition timing and the energy accumulated in an energy accumulating coil 11 are fed to the primary coil 14 of the ignition coil, and the high voltage for ignition is applied to the secondary coil 15, then, during a prescribed discharge period after that, transistors Q1 and Q11 are alternately connected/ disconnected to be multiply discharged. Since the capacitor 32 is connected to the capacitor 12 in series, even if one of the capacitors 12 or 32 is short- circuited, the other normal capacitor is charged with the energy accumulated in the energy accumulating coil 11 to secure the performance. In addition, as the withstand pressure of the capacitors 12 and 32 can be relatively small, the cost of the parts affected by the withstand pressure can be reduced and the manufacturing cost 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. An example of this type of ignition device is disclosed in
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.

[0003]

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, it is conceivable that a bypass path from the 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 the multiple discharge method to the single discharge method at the time of the failure. .

However, in the engine igniter provided with the above bypass path, even if the short-circuit of the capacitive discharge capacitor is detected and the system is switched to the single discharge method, for example, as long as the capacitive discharge capacitor is short-circuited, Since the current from the DC power supply flows to the ground through the capacitor for capacitive discharge, there is a problem that energy cannot be supplied to the primary coil of the ignition coil.

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 which can easily ensure performance even when a capacitor for capacitance discharge is short-circuited. I do. Another object of the present invention is to provide an ignition device for an engine that can reliably perform limp-home running during a failure.

It is still another object of the present invention to provide an ignition device for an engine which ensures fail-safe performance and ensures performance during a failure. Still another object of the present invention is to provide an ignition device for an engine which has a simple structure and reduces the cost of parts.

[0007]

According to the ignition device for an engine of the present invention, the first switching element is turned on / off and the first and second capacitors are operated by the energy stored in the energy storage coil. The discharge capacitor is charged, and the second switching element is turned on / off at the ignition timing, so that the energy charged in the first and second capacitive discharge capacitors 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 energy is stored in the secondary coil. A high voltage for ignition is applied, 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, since the second capacitance discharging capacitor is connected in series to the first capacitance discharging capacitor, one of the first capacitance discharging capacitor and the second capacitance discharging capacitor is short-circuited. Even if it reaches
As long as one of the first capacitor discharging capacitor and the second capacitor discharging capacitor is normal, the normal capacitor discharging capacitor is charged by the energy stored in the energy storage coil, and the energy is stored at the ignition timing. Since the power is supplied to the primary coil of the ignition coil, the performance can be easily secured. Furthermore, the withstand voltage of the first and second capacitors for capacitive discharge can be made relatively small, so that the cost of components affected by the withstand voltage can be reduced, and the manufacturing cost can be reduced with a simple configuration. it can.

According to the engine ignition device of the second aspect of the present invention, 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 reduced to the second power. Since it is supplied to the primary coil of the ignition coil via the second backflow prevention means, it is possible to perform limp-home 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. In addition, the second backflow prevention means prevents the energy charged in the first and second capacitors for discharging capacity from flowing back to the DC power supply side in a normal state other than the time of a failure.

Further, since the second capacitance discharging capacitor is connected in series to the first capacitance discharging capacitor, one of the first capacitance discharging capacitor and the second capacitance discharging capacitor is short-circuited. And when the short-circuit of the capacitor for capacitance discharge is detected and the system is switched to the single discharge method, the DC power supply is used as long as the other of the first capacitor for capacitance discharge or the second capacitor for capacitance discharge is normal. Does not flow to the ground through the capacitive discharging capacitor, and energy can be supplied to the primary coil of the ignition coil. Therefore, fail-safe performance can be ensured and fail-safe performance can be ensured. Furthermore, the withstand voltage of the first and second capacitors for capacitive discharge can be made relatively small, so that the cost of components affected by the withstand voltage can be reduced, and the manufacturing cost can be reduced with a simple configuration. it can.

According to the engine ignition device of the third aspect of the present invention, in the event 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 reduced to the second power. Since it is supplied to the primary coil of the ignition coil via the first and second backflow prevention means, it is possible to perform limp-home traveling. Therefore, it is possible to perform ignition using one DC power supply at the time of failure and other normal times,
An engine ignition device having a fail-safe function can be easily provided. In addition, the first and second backflow preventing means can be used to set the first and second currents in a normal state other than a failure state.
Is prevented from flowing back to the DC power supply side.

Further, since the second capacitor for discharging capacitance is connected in series to the first capacitor for discharging capacitance, either one of the first capacitor for discharging capacitance or the second capacitor for discharging capacitance is short-circuited. And when the short-circuit of the capacitor for capacitance discharge is detected and the system is switched to the single discharge method, the DC power supply is used as long as the other of the first capacitor for capacitance discharge or the second capacitor for capacitance discharge is normal. Does not flow to the ground through the capacitive discharging capacitor, and energy can be supplied to the primary coil of the ignition coil. Therefore, fail-safe performance can be ensured and fail-safe performance can be ensured. Furthermore, the withstand voltage of the first and second capacitors for capacitive discharge can be made relatively small, so that the cost of components affected by the withstand voltage can be reduced, and the manufacturing cost can be reduced with a simple configuration. it can.

According to the ignition device for an engine according to the present invention, in the event of a failure, the second switching element is turned on / off at the ignition timing by the second switching element control means, so that the energy of the DC power supply is reduced. Since it is supplied to the primary coil of the ignition coil via the second backflow prevention means, it is possible to perform limp-home 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. In addition, the second backflow prevention means prevents the energy charged in the capacitor for capacitance discharge from flowing back to the DC power supply side in a normal state other than the time of a failure.

Further, since the wiring portion which is blown when the capacitor for discharging capacity is short-circuited is connected in series to the capacitor for discharging capacity, the wiring portion is blown by a large current when the capacitor for discharging capacity is short-circuited, When the short-circuit of the capacitor for capacitance discharge is detected and the system is switched to the single discharge method, the current from the DC power supply does not flow to the ground through the capacitor for capacitance discharge, and energy can be supplied to the primary coil of the ignition coil. it can. Therefore, fail-safe performance can be ensured and fail-safe performance can be ensured. Furthermore, the wiring portion can prevent a large current from flowing to the second backflow prevention means, and can protect the second backflow prevention means.

According to the ignition device for an engine of the present invention, 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 reduced to the second power. Since it is supplied to the primary coil of the ignition coil via the first and second backflow prevention means, it is possible to perform limp-home traveling. Therefore, it is possible to perform ignition using one DC power supply at the time of failure and other normal times,
An engine ignition device having a fail-safe function can be easily provided. In addition, the second backflow prevention means prevents the energy charged in the capacitor for capacitance discharge from flowing back to the DC power supply side in a normal state other than the time of a failure.

Further, since the wiring portion which is blown when the capacitor for discharging the capacitance is short-circuited is connected in series to the capacitor for discharging the capacitance, the wiring portion is blown by a large current when the capacitor for discharging the capacitance is short-circuited, When the short-circuit of the capacitor for capacitance discharge is detected and the system is switched to the single discharge method, the current from the DC power supply does not flow to the ground through the capacitor for capacitance discharge, and energy can be supplied to the primary coil of the ignition coil. it can. Therefore, fail-safe performance can be ensured and fail-safe performance can be ensured. Furthermore, the wiring portion can prevent a large current from flowing to the second backflow prevention means, and can protect the second backflow prevention means.

[0018]

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 positive 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 first capacitor for discharging capacity. The capacitor 12 is connected in series with a capacitor 32 as a second capacitor for discharging capacity. Capacitors 12 and 32 are charged by the energy stored in energy storage coil 11.

A first cylinder ignition coil 1 is connected 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 transistor Q11 is turned on / off, and the capacitors 12 and 32 are turned on.
The energy charged to the primary coil 1 of the ignition coil 13
4 can be supplied. At this time, the current (primary current) flowing through the primary coil 14 is defined as i ₁ . A secondary cylinder 15 of the ignition coil 13 is connected to a first cylinder ignition plug (not shown). 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 and the transistor Q
Although 12 and the current detection resistor 20 are shown, ignition coils, transistors, and resistors for the number of engine cylinders are prepared.

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.). And ECU
21 determines an optimal ignition timing according to the engine state at that time. A drive circuit 22 is connected to the ECU 21, and the ECU 21 sends a cylinder discrimination signal I to the drive circuit 22.
Gt and a discharge section signal IGw are output. The above-described transistors Q1, Q11 and Q12 are connected to the drive circuit 22 as switching element control means, and the drive signal A is output to the transistor Q1 and the first cylinder drive signal B # 1 is output to the transistor Q11. Transistor Q12
Output the second cylinder drive signal B # 2.

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
_{According to 1} .

As described above, the battery 1 as a DC power supply
0, an energy storage coil 11, and a transistor Q1 as a first switching element, a first series circuit is formed, and a capacitor 1 is connected to the energy storage coil 11 via a diode D1 as backflow prevention means.
2 and 32 are connected. Further, capacitors 12 and 32, a primary coil 14 (18) of an ignition coil, and a transistor Q11 (Q
12) is formed.

Next, the operation of the ignition device configured as described above will be described with reference to FIG. Discharge section signal IGw
The cylinder discrimination signal IGt, the drive signal A of the transistor Q1, the drive signal B # 1 of the transistor Q11, the current i ₀ flowing through the energy storage coil 11, and the ignition coil 1
FIG. 2 shows signal waveforms and current waveforms of the primary current i ₁ and the secondary current i ₂ of FIG.

A cylinder discrimination signal IGt is output from the ECU 21 to the drive circuit 22.
It is at the H level during the period of t2. The drive circuit 22 outputs a drive signal A having a waveform synchronized with the signal IGt to the transistor Q1. The signal A causes the transistor Q1
Is turned on, the current i ₀ gradually increases, and the high voltage energy generated in the energy storage coil 11 when the transistor Q1 is turned off is supplied to the primary coil 14 of the ignition coil via the diode D1.

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 (inverted at timings t11, t12,...) Inverted every predetermined time as a drive signal A to the transistor Q1, and outputs the high-voltage energy generated in the energy storage coil 11 when the transistor Q1 is turned off. Are connected to the capacitors 12 and 3 through the diode D1.
2 (so-called multiple charging). During this repetitive operation, the drive circuit 22 outputs the signals (t2, t11, t11) complementary to the drive signal A as the drive signal B # 1.
, 12) are output to the transistor Q11. The signal B # 1, the energy of the capacitor 12 and 32 are supplied to the primary coil 14 of the ignition coil 13, when interruption of the primary current i ₁ (in FIG. 2 t1
2, which are large at the timings of 1, t13, t15, and t17)
A secondary current i ₂ (high voltage) is generated and multiple ignition is performed.
Then, for the next ignition, the transistor Q1 is set at t17.
And the off state at the timing t18. The energy generated in the energy storage coil 11 during the period from t17 to t18 is stored in the capacitors 12 and 32. That is, when the transistor Q11 is turned on during the period from t2 to t11 in the operation for the current ignition, the energy accumulated in the capacitors 12 and 32 and t1 to t2 during the period from t17 to t18 (the operation for the previous ignition). And the energy generated in the energy storage coil 11 during the period is supplied to the primary coil 14 of the ignition coil 13. That is, in the primary current i ₁ in the period t2~t11 in Figure 2, the projecting current portion e1
Is stored in the capacitors 12 and 32, and the energy generated in the energy storage coil 11 during the period from t1 to t2 covers the subsequent gentle current portion e2.

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 sets the transistor Q1 to the on / off (conducting / cutoff) state, thereby setting the energy storage coil 1
The capacitors 12 and 3
2 and the transistors (Q11 and the like) are turned on / off at the ignition timing to supply the energy charged in the capacitors 12 and 32 to the primary coil (14 and the like) of the ignition coil. Is performed. More specifically, the drive circuit 22 receives the cylinder discrimination signal IGt and the discharge interval signal IGw, and continuously turns on / off the transistor Q1 in a predetermined discharge interval for the target cylinder to multiply charge the capacitors 12 and 32. And the transistor (Q11 etc.)
1 is operated complementarily to perform multiple ignition.

In the first embodiment described above, the energy stored in the capacitors 12 and 32 and the energy stored in the energy storage coil 11 at the previous ignition timing are stored in the primary coil (14 or the like) of the ignition coil. While being supplied, a high voltage for ignition is applied to the secondary coil (15 or the like), and the spark plug generates a spark. Further, the transistors (Q1 and Q11)
) Are alternately intermittently performed and multiple discharges are performed, whereby ignition energy is supplied periodically during the discharge period, and the spark of the spark plug is maintained.

Further, the capacitor 32 is
Are connected in series, even if either the capacitor 12 or the capacitor 32 is short-circuited,
As long as the other one of the capacitor 12 and the capacitor 32 is normal, the normal capacitor is charged by the energy stored in the energy storage coil 11, and at the ignition timing, the energy is stored in the primary coil (14) of the ignition coil.
Etc.), the performance can be easily ensured. Furthermore, since the withstand voltage of the capacitors 12 and 32 can be made relatively small, the cost of components affected by the withstand voltage can be reduced, and the manufacturing cost can be reduced with a simple configuration.

(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 transistor Q21 and a diode D2 are connected in series between points c and b between the battery 10 and the energy storage coil 11. The drive circuit 22 includes a transistor Q
21 is connected, and outputs the switching drive signal SG1 to the transistor Q21. The ECU 21 determines that a failure has occurred when 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 energy storage coil 11 and the diode D1 in the series circuit including the battery 10, the energy storage coil 11, the diode D1, the primary coil 14 (18) of the ignition coil, and the transistor Q11 (Q12). Diode D2 as backflow prevention means
Are connected in parallel.

Next, the operation of the ignition device configured as described above will be described with reference to FIG. The normal operation other than the failure is the same as that of the first embodiment shown in FIG. FIG. 4 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, E
The CU 21 outputs the drive signal S at the timing of t20 in FIG.
G1 is set to the H level to turn on the transistor Q21, and as a signal to the drive circuit 22, the output level of the discharge section signal IGw is switched from the maximum of 5 volts so far to 12 volts. The drive circuit 22 monitors the voltage of the input port (indicated by P1 in FIG. 3) of the discharge interval signal IGw, and when the voltage is switched to 12 volts, the drive circuit 22 determines that the mode is the fail-safe mode and outputs the cylinder determination signal IGt for each cylinder The signals are distributed and output as signals B # 1 and B # 2. The signals B # 1 and B # 2 cause the transistor Q1
1 and Q12 are turned on / off. That is, in the first cylinder, the transistor Q11 is turned on at the timing of t21 in FIG. 4, and is turned off at the timing of t22. When the transistor Q11 is turned on, energy is supplied from the battery 10 to the primary coil 14 of the ignition coil via the diode D2.
When the primary current i ₁ is cut off (timing at t22 in FIG. 4)
, A large secondary current i ₂ (high voltage) is generated and used for ignition. Similarly, for the second cylinder, for example, the transistor Q12 is turned on at the timing of t23 in FIG. 4 and turned off at the timing of t24, and ignition is performed.

As described above, when a failure such as failure of the energy storage coil 11, the transistor Q1, the diode D1, the capacitors 12 and 32, or the occurrence of an abnormality in the wiring of these components occurs, the second switching element control means is used. Drive circuit 22 turns on / off (conducts / cuts off) the transistor Q11 (Q12) at the ignition timing to transfer the energy of the battery 10 through the diode D2 to the primary coil 14 (18) of the ignition coil.
To supply. Thereby, it is possible to perform the limp-home running. In addition, the diode D2 prevents the energy charged in the capacitors 12 and 32 from flowing back to the battery 10 in a normal state other than the time of a failure.

In this way, the limp-home running can be performed by operating the ignition coil 13 (17) with the energy of the battery 10 using the bypass path for the ignition energizing path that leads to the engine stop at the time of failure. As a result, one battery 1 at the time of a failure and other normal times
0 can be performed, and an engine 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 cut-off state to the conductive state at the time of a failure.
The energy supply path to the next coil 14 (18) can be reliably shut off.

Further, the capacitor 32 is connected to the capacitor 12
Connected in series, one of the capacitor 12 and the capacitor 32 is short-circuited. When the short-circuit of the capacitor for capacitance discharge is detected and the system is switched to the one-time discharge method, either of the capacitor 12 or the capacitor 32 is short-circuited. As long as the other is normal, current from the battery 10 does not flow to the ground through the capacitor for capacitive discharge, and energy can be supplied to the primary coil 14 (18) of the ignition coil. Therefore, fail-safe performance can be ensured and fail-safe performance can be ensured.

Furthermore, since the withstand voltage of the capacitors 12 and 32 can be made relatively small, the cost of components affected by the withstand voltage can be reduced, and the manufacturing cost can be reduced with a simple configuration. Further, the drive circuit 22 inputs 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. The transistor Q11 (Q12) can be easily controlled without generating a signal.

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 used. Mode switching information can be transmitted. Although the transistor Q21 and the diode D2 are provided on the bypass path in the second embodiment shown in FIG. 3, in the present invention, only the diode D2 may be provided.

(Third Embodiment) A third embodiment is shown in FIG.
The same components as those in the first embodiment shown in FIG. In the third 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.

Also in the third embodiment, the same effects as in the second embodiment shown in FIG. 3 can be obtained. The third
In the embodiment, when the diode D1 breaks down as compared with the second embodiment shown in FIG. 3, the failure cannot be dealt with. Therefore, the diode D1 of the third 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 third 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 makes it possible to reliably shut off the energy supply path from the battery 10 to the primary coil 14 (18) of the ignition coil via the diodes D1 and D20 at the normal time, not when a failure occurs. In the third embodiment, the transistor Q210 and the diode D20 are provided in the bypass path. However, in the present invention, only the diode D20 may be provided.

(Fourth Embodiment) FIG. 6 shows a fourth embodiment.
Components that are substantially the same as those of the second embodiment shown in FIG. In the fourth embodiment, as shown in FIG.
A bonding wire 42 serving as a wiring portion that is blown when the capacitor 12 is short-circuited is connected in series to the capacitor 12 instead of the capacitor 32 of the second embodiment shown in FIG. As shown in FIG. 7, the bonding wire 42 does not blow when the current value is relatively small in a normal state other than the time of failure, and blows when the current value is relatively large in a failure time when the capacitor 12 is short-circuited. Wire diameter is selected.

In the fourth embodiment, the capacitor 1
When the short circuit 2 occurs, the bonding wire 42 blows due to the large current, and when the short circuit of the capacitor 12 is detected and the system is switched to the single discharge mode, the current from the battery 10 does not flow to the ground through the capacitor 12. ,
Energy can be supplied to the primary coil 14 (18) of the ignition coil. Therefore, fail-safe performance can be ensured and fail-safe performance can be ensured.

Further, the bonding wire 42 prevents a large current from flowing through the transistor Q21 and the diode D2.
Can be protected. In the fourth embodiment, the bonding wire 42 is connected in series to the capacitor 12 instead of the capacitor 32 of the second embodiment shown in FIG. 3, but in the present invention, the bonding wire 42 of the third embodiment shown in FIG. Bonding wire is replaced with capacitor 1 instead of capacitor 32
2 may be connected in series. In the present invention,
Instead of the bonding wire 42 of the fourth embodiment shown in FIG. 6, a thin wire which is blown when the capacitor 12 is short-circuited may be connected in series to the capacitor for discharging capacitance.

Further, as the transistors Q1, Q11, Q12, Q21 and Q210 in the first, second, third and fourth embodiments, bipolar transistors and FETs are used.
(Preferably a P-channel MOSFET) or IGBT may be used, and any switching element may be used. Further, in the first, second, third and fourth embodiments, the case where the failure is detected by monitoring the primary current i ₁ using the resistors 16 and 20 has been described. Needless to say, for example, a method of monitoring an ion current 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 a signal waveform and a current waveform of the engine ignition device according to the first embodiment of the present invention.

FIG. 3 is an electrical configuration diagram showing an engine ignition device according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a signal waveform and a current waveform when an engine ignition device according to a second embodiment of the present invention fails.

FIG. 5 is an electrical configuration diagram showing an engine ignition device according to a third embodiment of the present invention.

FIG. 6 is an electrical configuration diagram showing an engine ignition device according to a fourth embodiment of the present invention.

FIG. 7 is a diagram for explaining conditions for selecting a wire diameter of a bonding wire of an engine ignition device according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Battery (DC power supply) 11 Energy storage coil 12 Capacitor (first capacitor for discharging capacity) 13, 17 Ignition coil 14, 17 Primary coil 16, 20 Current detecting resistor 21 ECU 22 Drive circuit (first switching element) Control means,
(Second switching element control means) 32 capacitor (second capacitor for discharging capacity) 42 bonding wire (wiring portion) Q1 transistor (first switching element) Q11, Q12 transistor (second switching element) Q21, Q210 transistor D1 diode (first backflow prevention means) D2, D20 diode (second backflow prevention means) IGt cylinder discrimination signal IGW discharge section signal

Claims (5)

[Claims] A first series circuit including a DC power supply, an energy storage coil, and a first switching element; a first capacitor for discharging a capacitive discharge connected to the energy storage coil via a backflow prevention unit; A second series circuit including a second capacitor for discharging capacity, a primary coil of an ignition coil, and a second switching element connected in series to the first capacitor for discharging capacity, and conducting the first switching element / Interrupted by the energy stored in the energy storage coil.
And charging and discharging the second switching element at ignition timing to supply the energy charged in the first and second capacitance discharging capacitors to the primary coil. And a switching element control means for controlling the ignition of the internal combustion engine. 2. A first series circuit including a DC power supply, an energy storage coil, and a first switching element, and a first capacitive discharge capacitor connected to the energy storage coil via first backflow prevention means. A second discharge capacitor connected in series with the first discharge capacitor, a primary coil of an ignition coil, and a second discharge capacitor.
A second series circuit including the switching element of (a), and charging / ignition of the first and second capacitors for discharging the first and second switching elements by energy stored in the energy storage coil by turning on / off the first switching element. A first switch for turning on / off the second switching element at a time to supply the energy charged in the first and second capacitance discharging capacitors to the primary coil;
Switching element control means; the DC power supply, the energy storage coil, the first backflow prevention means, the energy storage coil and the first backflow in a series circuit including the primary coil and the second switching element. A second backflow prevention means connected in parallel to the prevention means; and a second switching element which is turned on / off at an ignition timing at the time of a failure to transfer the energy of the DC power supply through the second backflow prevention means. An ignition device for an internal combustion engine, comprising: second switching element control means for supplying the primary coil. 3. A first series circuit including a DC power supply, an energy storage coil, and a first switching element, and a first capacitive discharge capacitor connected to the energy storage coil via first backflow prevention means. A second discharge capacitor connected in series with the first discharge capacitor, a primary coil of an ignition coil, and a second discharge capacitor.
A second series circuit including the first switching element, and the first switching element which is turned on / off by the energy stored in the energy storage coil.
And charging and discharging the second switching element at ignition timing to supply the energy charged in the first and second capacitance discharging capacitors to the primary coil. First switching element control means for performing the operation, second backflow prevention means connected in parallel with the energy storage coil, and conducting / cutting off the second switching element at the ignition timing at the time of a failure, so that the DC An ignition device for an internal combustion engine, comprising: second switching element control means for supplying energy of a power supply to the primary coil via the first and second backflow prevention means. 4. A first series circuit including a DC power supply, an energy storage coil, and a first switching element; a capacitor for capacitance discharge connected to the energy storage coil via first backflow prevention means; A second series circuit that is connected in series to the discharging capacitor and blows when the capacitive discharging capacitor is short-circuited, a primary coil of an ignition coil, and a second switching element; and the first switching element. The capacitor for discharging capacity is charged by the energy stored in the energy storage coil by conducting / cutting off, and the second capacitor is charged at the ignition timing.
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; An ignition device for an internal combustion engine, comprising: 5. A first series circuit including a DC power supply, an energy storage coil, and a first switching element; a capacitor for capacitance discharge connected to the energy storage coil via first backflow prevention means; A second series circuit that is connected in series to the discharging capacitor and blows when the capacitive discharging capacitor is short-circuited, a primary coil of an ignition coil, and a second switching element; and the first switching element. The capacitor for discharging capacity is charged by the energy stored in the energy storage coil by conducting / cutting off, and the second capacitor is charged at the ignition timing.
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. An ignition device for an internal combustion engine, comprising: