JPH0315665A - Ignition detection device of ignition device - Google Patents

Abstract

PURPOSE:To detect the existence of an ignition spark securely by detecting an ignition surge current produced in the primary circuit of an ignition coil by the capacity discharge of the ignition coil and detecting that the ignition surge current over a specified limit is produced in the primary circuit. CONSTITUTION:When an output transistor 2 is energized by an ignition signal through an amplifier circuit 1 and then de-energized, high-voltage is generated in the secondary coil of an ignition coil 3 and an ignition spark is produced at each ignition plug 4a through a distributor 4. In this case, when the ignition is normal, an ignition surge current produced by the capacity discharge of the ignition coil 3 is flown into a condenser 11, diode 14, and condenser 12 through the secondary coil of the ignition coil 3, and charged in the condenser 12. Then the charged voltage is compared by a comparator 18 with a comparative voltage determined by the voltage division ratio of a resistance 16 to a resistance 17, an output pulse is generated when the charged voltage exceeds the comparative voltage, and the existence of the output pulse is searched to detect mis-firing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ignition detection device for detecting the presence or absence of an ignition spark in an ignition device for an internal combustion engine mainly used in automobiles.

[Conventional technology]

In recent years, with the progress of computerization of fuel injection devices, ignition devices, exhaust control devices, and the like, there is a growing concern about the negative impact on exhaust gas when these devices fail.

The function of this type of device is to determine whether or not the ignition spark in the combustion chamber of the internal combustion engine has occurred normally. Analyze the waveform to determine whether the ignition spark was generated or not.
(e.g., U.S. Pat. No. 394,210)
2), and one that detects the flybank voltage generated at the collector of an output transistor that intermittents the primary winding current of the ignition coil (for example, Japanese Patent Laid-Open No. 143326/1983) has been proposed.

(Problem to be Solved by the Invention) However, although the former method described above can accurately detect the presence or absence of an ignition spark, it detects the high voltage output waveform on the secondary side of the ignition coil. ,2
In the process of introducing the next-side high voltage into the electronic circuit, it was necessary to take fairly sufficient insulation measures, and there was a problem that it could not be used as an in-vehicle device due to its structure and cost. .

In addition, in the latter conventional method described above, one of the ignition coils
Since the flyback voltage generated at the collector of the output transistor that intermittents the next-winding wA current is detected, there is no need to incorporate the secondary side high voltage into the electronic circuit, but even if a high voltage occurs on the secondary side of the ignition coil. Then, even if no ignition spark is generated, flyback voltage will occur, so the required voltage of the ignition plug may become higher than the secondary generated voltage of the ignition coil, or the high voltage cord may be disconnected, causing the ignition spark to be generated at the ignition plug. Even if no ignition spark occurs, there is a problem in that the ignition spark is erroneously detected as having occurred normally.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems and to satisfactorily detect the presence or absence of an ignition spark.

[Means to solve the problem]

Therefore, the present invention provides an ignition coil that has a primary winding connected to a primary circuit and a secondary winding connected to a secondary circuit. An ignition detection device that detects the presence or absence of an ignition spark in an ignition device that generates a high voltage for an ignition spark in a line,
of this ignition coil due to capacitive discharge of the ignition coil. 1
ignition surge current detection means for detecting ignition surge current occurring in the next circuit; and ignition surge current detecting means for detecting ignition surge current exceeding a predetermined value in the primary circuit of the ignition coil according to the output of the ignition surge current detection means; The present invention provides an ignition detection device for an ignition device, comprising a comparison means for detecting the ignition.

Here, the primary side circuit has one pole connected to one end of the primary winding, the other pole connected to a grounded DC power source, and one end connected to the other end of the primary winding, and the other end connected to a grounded DC power source. the secondary winding, and the secondary circuit includes a spark plug having one end connected to one end of the secondary winding and the other end grounded; The other end of the wire is connected to one end of the primary winding, and the ignition surge current detecting means is a wire connected between the ground and a connection point between the primary winding and the secondary winding. a series circuit of a first diode and a first capacitor charged by an ignition surge current of one polarity generated in the primary circuit through the first diode; a second diode connected between the connection point and the ground, and a second capacitor charged by the ignition surge current of the other polarity generated in the primary circuit through the second diode. The comparison means may compare the voltage of the second capacitor with a predetermined value.

The ignition surge current detection means includes a detection coil that is wound around the power line of the primary circuit and detects the ignition surge current generated by the power line C, and rectifies and integrates the voltage induced in the detection coil. The configuration may also include an integrating means.

Here, the detection coil may be wound around a power line connecting a connection point between the primary winding and the secondary winding and the DC power supply.

Further, the detection coil can also be wound around a power supply line of an amplifier circuit that amplifies the ignition signal.

Furthermore, the detection coil can be wound around the capacitor a4a of the Hirashigawa built in the amplifier circuit.

The ignition surge current detection means includes a diode connected in parallel with the grounding line of the primary circuit, and a capacitor charged by the ignition surge current of one polarity generated in the primary circuit via the diode. The voltage of the capacitor may be compared with a predetermined value by the comparing means.

Furthermore, the ignition device is inside t! ! ! ．． An ignition device for an internal combustion engine has a plurality of the ignition coils corresponding to the number of the ignition coils of the engine, and a plurality of the ignition surge T flow detection means and the comparison means are provided corresponding to each of the ignition coils, and It is also possible to provide means for validating only the output detected at the normal ignition timing by the comparison means.

Further, a grounding line in the grounding path of the comparison means is provided in a different path from the grounding path of the igniter, which includes an amplifier circuit that amplifies the ignition signal and an output transistor that connects and disconnects the primary winding current by the output of the amplifier circuit. An AC coupling capacitor is connected between the ignition coil and the anti-ground side of the DC power source, so that the ignition surge current of the ignition coil is passed through the AC coupling capacitor to the grounding wire, and the ignition surge current detection means and the comparison means are connected. It may be provided separately from the igniter to monitor the ignition sensor.

Here, an AC impedance element may be included in the ground line.

Furthermore, a single ignition sensor is commonly provided for each ignition coil provided for each cylinder, and the output signal of the ignition sensor and the ignition signal of each cylinder are logically connected to each cylinder. It is also possible to provide a separate ignition discrimination means for detecting each ignition.

(Function) As a result, the ignition surge current generated in the primary circuit of the ignition coil due to capacitive discharge of the ignition coil is detected by the ignition surge current detection means, and the ignition surge current is detected by the ignition surge current detection means. When an ignition surge current of a predetermined value or more occurs in the next circuit, the comparison means detects it, thereby detecting the presence or absence of an ignition spark.

Here, as the ignition surge current detection means, the surge current generated in the primary circuit via the first diode connected between the ground and the connection point between the primary winding and the secondary winding of the ignition coil is used. The first capacitor is charged by the ignition surge current with the polarity of It is also possible for the second capacitor to be charged by the resulting ignition surge current of the other polarity. The presence or absence of an ignition spark may be detected by comparing the voltage of this second capacitor with a predetermined value using a comparison means.

The ignition surge current detection means detects the ignition surge current generated in the power supply line by a detection coil wound around the power supply line of the primary side circuit, and rectifies and integrates the voltage induced in the detection coil by an integration means. You can also. Then, the voltage of this second capacitor and a predetermined value may be compared by a comparing means to detect the presence or absence of an ignition spark.

The ignition surge current detection means is configured to charge a capacitor with the ignition surge current of one polarity generated in the primary circuit via a diode connected in parallel with the grounding line of the primary circuit. The voltage of this capacitor may be compared with a predetermined value by a comparing means to detect the presence or absence of an ignition spark.

Furthermore, when the present invention is applied to an ignition device for an internal combustion engine that has a plurality of ignition coils corresponding to the number of ignition coils of the internal combustion engine,
A plurality of ignition surge current detection means and comparison means are provided corresponding to each ignition coil to detect the ignition surge current due to capacitive discharge of each ignition coil, and furthermore, each comparison means detects only the output detected at the regular ignition timing. If the ignition coils of other cylinders are enabled, 1
It can also prevent erroneous detection of noise occurring in the next-side circuit. In addition, the grounding wire in the grounding path of the comparison means, which is provided in a different path from the grounding path of the igniter, and the anti-grounding side of the DC power source are connected by an AC coupling capacitor, so that the ignition surge current of the ignition coil is It is also possible to detect the ignition surge current flowing in the grounding wire by using an ignition sensor configured by supplying the ignition surge current to the grounding wire via an AC coupling capacitor, and providing an ignition surge current detection means and a comparison means separately from the igniter. .

Here, it is also possible to insert an AC impedance element into the ground wire to add it to the AC impedance of the ground wire itself.

Furthermore, a single ignition sensor is commonly provided for each ignition coil provided for each cylinder, and the ignition is determined by each cylinder by logic between the output signal of the ignition sensor and the ignition signal of each cylinder. It is also possible to perform ignition detection for each cylinder by the means.

〔Example〕

A first embodiment of the present invention will be described with reference to the electric circuit diagram shown in FIG. 1 and the operational waveform diagram shown in FIG.

In FIG. 1, ``■'' is an amplifier circuit that amplifies the ignition signal from the input terminal 1a, and 2 is an output transistor that is turned on and off by the output of the amplifier circuit 1.

3 is an ignition coil in which the primary winding current is intermittent by the output transistor 2; one end of the secondary winding is connected to the primary winding positive terminal 3b, and the other end 3a is connected to the ignition distributor 4;
This ignition distributor 4 distributes high voltage to a plurality of spark plugs 4a. 5 is a key switch, and 6 is a battery, the positive terminal of which is connected to the primary winding positive terminal 3b via the key switch 5, and the negative terminal thereof is grounded.

Reference numerals 10a and 10b are ignition surge current detection means and comparison means that constitute the ignition detection device, and their structure is as follows. 11.12 are the first and second capacitors, 13.14 are the first and second diodes, 15, 16
．． 17 is a resistor, and 18 is a comparator.

Next, the operation of the first embodiment of the present invention shown above will be explained.

First, by the ignition signal shown in FIG. 2(a), the amplifier circuit l
After the output transistor 2 is turned on through the ignition coil 3, a high voltage is generated in the secondary winding of the ignition coil 3.

When each ignition plug 4a ignites normally due to this high voltage via the ignition distributor 4, the ignition surge current generated by the capacitive discharge of the ignition coil 3 is transmitted from the ignition plug 4a to the secondary winding of the ignition coil 3. and the second capacitor
, second diode l4, and second capacitor l
2 and charges the capacitor 12 to the polarity shown. As shown in Fig. 2(b), this ignition surge current is a high frequency current with a peak value of approximately 1 (approximately 10 MHz) reaching several amperes to several tens of thousands of amps. Therefore, when the ignition surge current flows in the opposite direction, flows from the spark plug 4a through the ground (GND) and further through the first diode l3 in the direction of discharging the charge in the first capacitor 11. Therefore, the high frequency ignition surge current causes the capacitors 11 and 12 to , full-wave rectification is performed by the structure of diodes 13 and 14 as shown in Fig. 2 (
As shown in C), the capacitor l2 is charged. Next, by comparing this charging voltage with a comparison voltage Vref determined by the voltage division ratio of the resistors 16 and 17 using the comparator 18, an output pulse as shown in FIG. 2(d) can be obtained. Therefore, if ignition is not performed for some reason, this high-frequency ignition surge current will not flow, and no output pulse will be generated. By checking the presence or absence of this output pulse using various methods, misfire can be detected.

Next, a second embodiment shown in FIG. 3 will be described. Second
In this embodiment, an ignition coil 3 is provided for each spark plug. The difference between this second embodiment and the first embodiment is that, in addition to the ignition detection devices 10a and 1(lb), a delay pulse of a certain time width is generated based on the ignition signal in synchronization with the fall of the ignition signal. , for example, a delay circuit 20 consisting of a falling trigger monostable circuit and an AND circuit 30 are added to each cylinder.
When using this, the purpose is to eliminate the influence of noise from ignition sparks of adjacent cylinders, and the operation will be explained below. Fourth
As shown in the waveform of FIG. 4(b), in addition to the normal ignition surge current b1 corresponding to the ignition signal of the specific cylinder shown in FIG. The voltage charged to the capacitor 12 is shown in Figure 4 (C
).

As shown in FIG. 4(d), the output pulses of the detection device 10a and fob are also different from the normal pulse d1 to the pulse d. , d3 occurs.

However, if these pulses d l-d 3 and the output delay pulse of the delay circuit 20 shown in FIG. 4(e) are ANDed,
By performing AND logic in the circuit 30, as shown in FIG.
As shown in Figure 2, the negative effects of noise can be eliminated.

In the first embodiment described above, the output of the comparator 18 is used as it is, but it goes without saying that the same effect can be obtained by combining monostable circuits.

Further, although in the second embodiment described above, the logic is based on the delay pulse caused by the ignition signal, the masking of the capacitor I2 may be performed directly using the delay pulse signal. In other words, it goes without saying that the same effect can be expected by short-circuiting the potential of the capacitor 12 at times other than when the regular ignition surge current occurs.

Next, a third embodiment of the present invention will be described.

In the third embodiment shown in FIG. 5, a detection coil 50 for detecting spark surge current connects one side of the secondary winding to the primary winding power supply positive electrode 3a.
It is wrapped around the power supply positive electrode wire of the ignition coil 3 connected to the side. Then, upon ignition, the detection coil 50 detects that the spark surge current generated by the capacitive discharge of the ignition coil 3 flows from the ignition plug 4a, through the ignition distributor 4, the ignition coil secondary winding, and into the power supply positive electrode line 3a, This detected high frequency current is rectified by the diode 4l, and the capacitor 42 is charged via the resistor 43. Here, Daioto 4
1,000 stages of integration by L resistors 43, 47 and capacitor 42
The 1,000-stage integration stage 40a and the detection coil 50 constitute an ignition surge current detection means. An output is obtained by comparing the charging voltage of this capacitor 42 with a comparison voltage determined by resistors 44 and 45 using a comparator 46. Here, the resistors 44, 45 and the comparator 46 constitute a comparing means 40b. In this way, in the first and second embodiments, the spark surge current was detected inside the detection circuit 40, but as in the third embodiment, the detection coil 5
It goes without saying that the same effect can be expected even if 0 is provided in the spark surge current path on the primary side of the ignition coil.

Further, as in the fourth embodiment shown in FIG.
0 may be wound around the power line of the ignition amplifier 1, or, as in the fifth embodiment shown in FIG. However, it goes without saying that similar effects can be expected.

FIG. 8 shows a sixth embodiment of the present invention, in which the amplifier circuit 1
, the ignition surge current detection means 10 is connected in parallel with the resistor 17 and the grounding line l9 connecting between the output transistor 2 and the ground.
A series circuit of a diode 13 and a capacitor 12, which constitute a circuit a, is connected, and a smoothing capacitor 1b is connected between the grounding line 19 and the primary winding positive terminal 3b. According to this sixth embodiment, due to the inductance included in the wiring of the grounding wire 19, the diode 1
Sufficient impedance (voltage drop) occurs in the ground line 19 to make it conductive. Therefore, the ignition surge current generated by the capacitive discharge of the ignition coil 3 flows from the ignition plug 4a through the ground, through the diode l3, the capacitor 12, and the smoothing capacitor 1b to the primary winding positive terminal 3b. Charge to the polarity shown. and,
The charging voltage of the capacitor l2 is compared with a predetermined value using a comparison lob to detect the presence or absence of ignition.

Here, as shown in FIG. 9, the amplifier circuit 1, the ignition surge current detection stage 10a, the comparison stage 10b, etc. are mounted on a thick film board 6l.
It is controlled above. A chimp capacitor l2 and a free-chip type diode l3 are connected to a conductor printed on the thick film substrate 61. and,
A conductor constituting the ground line l9 is grounded to the metal case 63 via an aluminum wire bond 62. Therefore, by changing the length of the grounding wire l9, the diode 13 and capacitor 1
Wiring length Ll of the series circuit with 2 and wiring length L2 of the grounding wire l9
Ratio: L2/LL and capacitor 12 during normal ignition
The terminal voltage of and . When we examine the relationship between
A characteristic was obtained in which the terminal voltage of the capacitor l2 became higher as L2/L became larger. Therefore, from the relationship between the above-mentioned wiring length ratio and the terminal voltage of capacitor I2 during normal ignition, the set voltage of comparison means tab is set to capacitor 1.
By setting the voltage to a value slightly lower than the terminal voltage of No. 2, it is possible to accurately detect whether or not the ignition spark is generated normally. In particular, as in this sixth embodiment, the grounding wire 19
By utilizing the impedance of It has the advantage of being less susceptible.

In the sixth embodiment, where the amplifier circuit l includes the smoothing capacitor lb, it goes without saying that the smoothing capacitor ib does not need to be provided in the ignition surge current detection means 10a.

In addition, in the sixth embodiment, the grounding line l9 is shared by the amplifier circuit 1, the output transistor 2, and the comparison stage 10b, but it is not necessary to share it with all of them, and it is parallel to at least one part of the grounding line. diode 13 and capacitor l
It is only necessary to connect a series circuit with 2.

Furthermore, in the sixth embodiment, the connection arrangement between the diode 13 and the capacitor 12 is changed so that the capacitor 12
The negative electrode side voltage may be detected by the comparison stage 10b.

FIG. 11 shows a seventh embodiment of the present invention.
In contrast to the embodiment, the grounding line l9 in the grounding path of the comparing means lob, which is provided in a separate path from the grounding path of the igniter lA including the amplifier circuit l and the output transistor, and the commonly connected l of each ignition coil 3. An AC coupling capacitor 1c is connected between the next winding positive terminal 3b, and each ignition coil 3
The ignition surge current is passed through the AC coupling capacitor lc to the grounding wire l9, and the ignition surge current detection stage lOa and comparison means 10b are provided separately from the igniter IA to constitute an ignition sensor. A single sensor is used in common for each ignition coil 3 provided corresponding to each cylinder, and ignition detection for each cylinder is performed by logic between the output signal of the ignition sensor and each simple ignition signal. It is equipped with 1,000 steps of 2 (10 steps) for each ignition to be performed.

In FIG. 11, IB is a well-known electronic control unit including a microcomputer, which calculates and outputs ignition signals T1 to T4 for each cylinder by manually inputting various engine parameters such as engine speed and engine load condition. Reference numeral 60 denotes an ignition detection pulse generation circuit which generates an ignition detection pulse by inputting a signal obtained by differentiating the falling edge of each ignition signal T1 to T4 from each ignition discrimination means 2 (10) and an output signal from the comparison means 10b. , transistors 61-64, resistors 65-6
9 and the delay circuit 70. 80 is a constant voltage circuit that receives the output of the battery 6 as an input and generates a constant voltage output. In addition, ignition discrimination means 2 (10) are provided as many as the number of ignition discrimination means 2 (10).
are transistors 201 to 206, resistors 207 to 216,
Capacitor 217, diode 218, logic element 219
, 220, respectively. 3 (10) is each display device connected to the output of each ignition discrimination circuit 2 (10), which displays the ignition status of each light using a light emitting diode.

Next, the operation of the seventh embodiment will be explained, including the operation waveform diagram shown in FIG. 12. Figure 12 (T, ~ (T4) is EC
It is assumed that the ignition signal is an ignition signal outputted from tJ IB corresponding to each cylinder, and each spark plug 4a ignites at the falling edge of the ignition signal.

Therefore, under normal conditions, the output of the comparison stage 10b generates a positive pulse shown in FIG. 12(A) in the comparison means 10b immediately after ignition. Separately, each ignition signal T I"" T 4 inputted to the igniter IA is branched and inputted to each ignition determination means 2 (10).

Each ignition signal input to this ignition discrimination means 2 (10) is
The ignition signals T, -T. At the falling edge of , a differential pulse shown in FIG. 12(B) is generated. Then,
During normal operation, the ignition detection pulse generation circuit 60 detects the falling edge of each of the ignition signals T1 to T4 to determine the comparison stage 10b.
An ignition detection pulse is generated at the collector of the transistor 64 for a short period of time until the ignition detection pulse shown in FIG. 12(A) is generated (see FIG. 12(C)). However, for example, if the ignition corresponding to one ignition signal T4 among the ignition signals T I - T < is not performed at time 1 and a misfire occurs, the next A long-time ignition detection pulse is generated in the transistor 64 of the ignition detection pulse generation circuit 60 until time t2 when ignition corresponding to the ignition signal T1 is performed. By delaying these ignition detection pulses by the delay circuit 70, the waveform shown in FIG. 12(D) is obtained as the output of the ignition detection pulse generation circuit 60. Then, when determining the ignition state of a certain cylinder based on this waveform (D), the delayed ignition detection pulse signal (D) is detected by timing the falling edge of the ignition signal of the next cylinder. It can be seen that this is possible by determining whether the waveform of is high level or low level. In other words, in FIG. 12, if a misfire occurs easily at time t corresponding to ignition signal T4,
In synchronization with the next falling edge of the ignition signal T1, the ignition signal T. The ignition determination circuit 2 corresponding to
The logic between the pulse signal waveform shown in FIG. 2(E) and the delayed ignition pulse signal (D) waveform corresponding to the ignition signal T4 is determined by each logic element 219 . 220.

FIG. 12 (
By each output shown as F) and (G), transistor 2
04 and 205 and the resistors 213 to 216, the 12th
The ignition determination signal as shown in the waveform of FIG. 14 can be obtained at any time.

Then, by operating the display device 3 (10) of the corresponding cylinder based on this ignition discrimination signal, and by causing a light emitting diode, for example, to emit light from the display device 3 (10), the misfiring cylinder can be visually recognized by the user.

FIG. 13 shows an eighth embodiment of the present invention.
In contrast to the embodiment, a cylinder-specific ignition discrimination stage 2 (10) is configured by software of a microcomputer in the electronic control unit 1B, and is configured to stop fuel injection in the event of a misfire in the spark plug 4a. It is.

In FIG. 13, 19a is an alternating current impedance element such as a resistor or inductance, which is inserted and connected into the grounding wire 19 in order to adjust the alternating current impedance contained in the grounding wire 19 when it is small. Further, the comparison means 10b is composed of a resistor 18a and a transistor 18b. 3 (10 is a monostable multi-by-break that is triggered by the output of the comparison stage 10b and generates an output pulse of a predetermined time width (for example, 1, 5 tatami), 4 (
10 is an output circuit for supplying the output of the monostable multiviprator 3 (10) to the electronic control unit 1B;
Ignition sensor 5 (igniter IA as 10)
(Fig. 11) and the electronic control unit}IB.

By providing the ignition sensor 5 (10) separately in this way, the ignition sensor 5 (10) can be attached separately without changing the internal configuration of the igniter IA or the electronic control unit IB, which increases the degree of design freedom. improves.

〔Effect of the invention〕

As described above, in the present invention, the ignition surge current generated in the primary circuit of the ignition coil due to capacitive discharge of the ignition coil is detected by the ignition surge current detection means, and the ignition surge current is detected according to the output of the ignition surge current detection means. ignition coil 1
When an ignition surge current that exceeds a predetermined value occurs in the next circuit, it is detected by the comparison means, so it can be determined whether or not an ignition spark is generated based on the ignition surge current that occurs in the primary circuit of the ignition coil due to capacitive discharge of the ignition coil. In addition, since there is no need to incorporate the secondary high voltage of the ignition coil into the electronic circuit, the insulation method can be simplified, and it has the excellent effect of being able to be installed at low cost with a small body. be.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram showing a first embodiment of the device of the present invention, and FIG. 2 is a waveform diagram of various parts for explaining the operation of the device shown in FIG. 1.
FIG. 3 is an electric circuit diagram showing a second embodiment of the device of the present invention, and FIG. 4 is a waveform diagram of various parts for explaining the operation of the device shown in FIG.
5 to 8 are electric circuit diagrams respectively showing the third to sixth embodiments of the device of the present invention, FIG. 9 is a perspective view showing the main structure of the sixth embodiment, and FIG. Characteristic diagram showing the relationship between wiring length ratio and capacitor terminal voltage in Example 6, No. 11
13 are electrical circuit diagrams showing seventh and eighth embodiments of the present invention, and FIG. 12 is a waveform diagram of various parts for explaining the operation of the apparatus shown in FIG. l...Amplification circuit, lb...Smoothing capacitor. 1
C... AC coupling capacitor, IA... igniter 5
2... Output transistor, 3... Ignition coil, 4...
...Ignition distributor, 4a...Spark plug. 6... Hatter, 10a... Ignition surge current detection means, 10b.
... Comparison means, 11... First capacitor, 12...
・Second capacitor, 13...lth diode, 1
4...Second diode, l9...Grounding wire, 19a
...AC impedance. 20...delay circuit, 30
...A'ND circuit. 40a, 50... Integrating circuit and detection coil constituting surge current detection means, 40b...
Comparison means, means for differentiating ignition. 5 (10...Ignition sensor.

Claims (11)

[Claims] (1) By interrupting the primary winding current of an ignition coil having a primary winding connected to a primary circuit and a secondary winding connected to a secondary circuit, An ignition detection device that detects the presence or absence of an ignition spark in an ignition device that generates a high voltage for an ignition spark, the ignition detection device detecting an ignition surge current that occurs in the primary circuit of the ignition coil due to capacitive discharge of the ignition coil. Ignition detection of an ignition device comprising a surge current detection means and a comparison means for detecting when an ignition surge current of a predetermined value or more occurs in the primary circuit of the ignition coil according to the output of the ignition surge current detection means. Device. (2) The primary side circuit has one pole connected to one end of the primary winding, the other pole connected to a DC power source that is grounded, and one end connected to the other end of the primary winding, and the other pole connected to the other end of the primary winding. the secondary circuit includes a spark plug having one end connected to one end of the secondary winding and the other end being grounded; The other end of the secondary winding is connected to one end of the primary winding, and the ignition surge current detection means is connected between the ground and the connection point between the primary winding and the secondary winding. a first diode connected to
a series circuit with a capacitor, a second diode connected between the connection point of the first diode and the first capacitor and the ground, and the second diode and the first capacitor. a second polarity charged by the ignition surge current of the other polarity generated in the primary circuit through the
2. The ignition detection device for an ignition device according to claim 1, further comprising a series circuit with a capacitor, wherein said comparison means compares the voltage of said second capacitor with a predetermined value. (3) The ignition surge current detection means includes a detection coil that is wound around the power line of the primary side circuit and detects the ignition surge current generated in the power line, and rectifies and integrates the voltage induced in the detection coil. 2. The ignition detection device for an ignition device according to claim 1, further comprising an integrating means for comparing the output value of the integrating means with a predetermined value. (4) The primary side circuit has one pole connected to one end of the primary winding, the other pole connected to a DC power source that is grounded, and one end connected to the other end of the primary winding, and the other pole connected to the other end of the primary winding. the secondary circuit includes a spark plug having one end connected to one end of the secondary winding and the other end being grounded; The other end of the secondary winding is connected to one end of the primary winding, and the detection coil connects between the connection point between the primary winding and the secondary winding and the DC power source. 4. The ignition detection device for an ignition device according to claim 3, wherein the ignition detection device is wound around a power supply line. (5) The primary side circuit includes an amplifier circuit that amplifies the ignition signal and an output transistor that cuts the primary winding current on and off using the output of the amplifier circuit, and the detection coil is connected to the power supply line of the amplifier circuit. 4. The ignition detection device for an ignition device according to claim 3, wherein the ignition detection device is wrapped around the ignition device. (6) The primary side circuit includes an amplifier circuit that amplifies the ignition signal and an output transistor that connects the primary winding current with the output of the amplifier circuit, and the amplifier circuit has a built-in smoothing capacitor. 4. The ignition detection device for an ignition device according to claim 3, wherein the detection coil is wound around the power supply line of the smoothing capacitor. (7) The primary side circuit has one pole connected to one end of the primary winding, the other pole connected to a DC power source that is grounded, and one end connected to the other end of the primary winding, and the other pole connected to the other end of the primary winding. the secondary circuit includes a spark plug having one end connected to one end of the secondary winding and the other end being grounded; The other end of the secondary winding is connected to one end of the primary winding, and the ignition surge current detecting means connects the ignition surge current to a diode connected in parallel with the grounding wire of the primary circuit, and The ignition device according to claim 1, comprising a series circuit with a capacitor charged by an ignition surge current of one polarity occurring in the primary side circuit, and wherein the comparing means compares the voltage of the capacitor with a predetermined value. ignition detection device. (8) The ignition device is an ignition device for an internal combustion engine having a plurality of ignition coils corresponding to the number of cylinders of the internal combustion engine, and the ignition surge current detection means and the comparison means correspond to each of the ignition coils. The ignition detection device for an ignition device according to any one of claims 1 to 7, further comprising means for validating only the output detected at the regular ignition timing by each of the comparison means. . (9) The switching means is composed of an igniter including an amplifier circuit that amplifies the ignition signal and an output transistor that switches the primary winding current on and off using the output of the amplifier circuit, and the ground wire is not connected to the ground path of the igniter. provided as a separate route and constituting a grounding route for the comparison means;
Furthermore, an AC coupling capacitor is connected between this grounding wire and the anti-grounding side of the DC power supply, so that the ignition surge current of the ignition coil is caused to flow through the AC coupling capacitor to the grounding wire, and the ignition surge current is caused to flow through the grounding wire through the AC coupling capacitor. 8. The ignition detection device for an ignition device according to claim 7, wherein the current detection means and the comparison means are provided separately from the igniter to constitute an ignition sensor. (10) The ignition detection device for an ignition device according to claim 7 or 9, wherein the grounding wire includes an AC impedance element. (11) The ignition device is an ignition device for an internal combustion engine having a plurality of ignition coils corresponding to the cylinders of the internal combustion engine, and the ignition sensor is provided with a single one for each of the ignition coils. 10. The ignition detection device for an ignition system according to claim 9, further comprising cylinder-by-cylinder ignition discrimination means for performing ignition detection for each cylinder by performing logic between the output signal of the ignition sensor and the ignition signal of each cylinder.