JPH08135548A - Capacity discharge type ignition device for internal combustion engine - Google Patents

Abstract

PURPOSE: To prevent wasteful power consumption and generation of heat by stopping the pressure rising operation to an ignition condenser in the case where the charging voltage of the ignition condenser can not be increased normally. CONSTITUTION: Even if the boosting operation of a boosting circuit 300 is allowed by a boosting control circuit 500, a charging monitoring circuit 700 monitors the charging voltage of a condenser 7. In the case where the voltage of the ignition condenser 7 is not increased normally, the boosting operation of the boosting circuit 300 is stopped by an oscillation stopping circuit 600.

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, and more particularly to a capacity discharge ignition device for an internal combustion engine which uses a DC power source such as a battery as a power source.

[0002]

2. Description of the Related Art Conventionally, for example, JP-A-51-89942.
In the capacity discharge type internal combustion engine ignition device described in the publication, the ignition capacitor is charged by applying the boosted voltage of the booster transformer to the ignition capacitor through the rectifying diode. Then, when the charging voltage of the ignition capacitor reaches a constant value, the boosting operation for this capacitor is stopped so that the charging voltage of the capacitor is maintained at a constant value, so that the internal combustion engine has a wide range from low speed to high speed. There is an ignition device that maintains reliability as an ignition device.

Further, like the capacitor charging / discharging type ignition device described in Japanese Patent Publication No. 6-31601, the ignition capacitor is charged by applying the boosted voltage of the boosting transformer to the ignition capacitor through a rectifying diode. To do. Then, when it is detected that the ignition SCR connected in series to the ignition capacitor is erroneously ignited due to deterioration in withstand voltage or the like while the charging voltage of the ignition capacitor is increasing, the boosting operation for the ignition capacitor is stopped. Some have been done.

[0004]

By the way, in these devices, for example, a current leaks from the ignition capacitor due to an increase in the reverse recovery time of the rectifying diode when the ambient temperature rises abnormally, or an internal leak of the ignition capacitor occurs. May occur. In these cases, the charging voltage of the ignition capacitor does not reach a fixed value, and the ignition of the ignition SCR is not detected. As a result, the boosting operation for the ignition capacitor cannot be stopped.

Therefore, in such a case, the charging voltage of the ignition capacitor does not rise normally, and although the normal ignition operation cannot be performed, the boosting operation of the ignition capacitor is continued. For this reason, there is a problem that battery power consumption and heat generation of the device are wastefully generated. Therefore, in order to cope with such a situation, the present invention stops the boosting operation for the ignition capacitor in the internal combustion engine capacitive discharge ignition device when the charging voltage of the ignition capacitor cannot be normally increased. Therefore, it is intended to prevent wasteful power consumption and heat generation.

[0006]

In order to solve the above problems, in the invention described in claim 1, a DC power source (1)
A boosting means (300) for boosting the DC voltage from the ignition capacitor, and an ignition capacitor (7) charged by the boosting means,
Ignition means (9, 10) for igniting the internal combustion engine by the charging voltage of the capacitor, and boosting state monitoring means (700) for monitoring the boosting state of the charging voltage to a desired voltage, and this boosting state monitoring A capacity discharge ignition device for an internal combustion engine, comprising: boosting stop means (600) for stopping the boosting operation of the boosting means (300) when the result of monitoring by the means is that the charging voltage does not rise to the desired voltage. Will be provided.

According to a second aspect of the present invention, in the internal combustion engine capacitive discharge ignition device according to the first aspect, the boosting state monitoring means (700) delays a predetermined time after the charging of the capacitor (7) is started. Therefore, a comparison means (70) for comparing the charging voltage with a set voltage is provided, and when the comparison by the comparison means results in that the charging voltage is lower than the set voltage, the boost stop means (600) boosts the voltage. It is characterized in that the boosting operation of the means (300) is stopped.

The reference numerals in parentheses of the above-mentioned respective constituent elements and means indicate the corresponding relationship with the concrete constituent elements and means described in the embodiments described later.

[0009]

As described above, according to the invention as set forth in claim 1, the result that the charging voltage of the capacitor (7) does not rise to the desired voltage by the monitoring by the boosting state monitoring means (700). When this happens, the boosting stop means (600) stops the boosting operation of the boosting means (300).

As a result, useless boosting operation of the boosting means (300) is stopped. Therefore, needless to say, unnecessary heat generation in the booster unit (300) can be suppressed, and useless power consumption of the DC power supply (1) can be prevented. According to the second aspect of the invention, when the comparison by the comparison means (70) results in that the charging voltage is lower than the set voltage, the step-up stop means (600) causes the step-up means (3).
00) stop the boosting operation.

As a result, the same effect as that of the invention described in claim 1 can be achieved with a simple structure.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a capacity discharge ignition device for an internal combustion engine for a motorcycle. This ignition device includes an ignition thyristor 6, an ignition capacitor 7, an ignition coil 9, and an ignition plug 10.
It is equipped with a capacitive discharge ignition circuit. The diode 8 is a known DC arc diode. The resistor 5 is a gate protection resistor for the thyristor 6.

The ignition device is provided with a constant voltage power supply 100, which is supplied with a DC voltage from a battery 1 through an ignition switch 2 and a diode 3 to generate a constant voltage. The diode 3 is a circuit protection diode when the polarity of the battery 1 is reversely connected. When the overvoltage detection circuit 200 detects that the DC voltage of the battery 1 is excessive due to the Zener diode 20 and the resistor 21, the overvoltage detection circuit 200 causes the oscillation stop circuit 600 of the boost control circuit 500 to stop the boost operation of the boost circuit 300. A high-level detection signal (B) (see FIG. 2) is sent. Further, the overvoltage detection circuit 200 stops the boosting operation of the booster circuit 300 when it detects that the charging voltage of the ignition capacitor 7 is excessively high due to the Zener diode 22 and the resistor 23 via the voltage dividing resistors 73 and 74. In order to cause the oscillation stop circuit 600 to detect the high level detection signal (B)
(See FIG. 2).

The structure of the booster circuit 300 is disclosed in Japanese Patent Laid-Open No. 3-85.
It is disclosed in Japanese Patent No. 370. That is, the current of the primary coil 38a of the transformer 38 flowing from the battery 1 is turned on / off by the transistor 33, and the ignition capacitor 7 is charged with the current of the secondary coil 38b, which responds to the current of the primary coil 38a. It is a DC-DC converter that self-oscillates by positive feedback of the tertiary coil 38c.

Reference numeral 30 is a diode for protecting the circuit, reference numeral 31 is a resistor for supplying a current to the base of the transistor 33, reference numeral 32 is a zener diode for detecting a surge and absorbing it in the transistor 33, and reference numeral 34.
Is a resistance for flowing a positive feedback current of the tertiary coil 38c, and 37 is a resistance for detecting the current of the primary coil 38a.

When a predetermined current flows through the resistor 37, a predetermined voltage is generated due to a voltage drop, a base current flows through the transistor 35 through the resistor 36, the transistor 35 is turned on, and the base current of the transistor 33 is shunted. Turn off 33. At this time, the secondary coil 38b charges the ignition capacitor 7 through the diode 39. The tertiary coil 38c bypasses the base current of the transistor 33 via the resistor 34 and holds the transistor 33 in the off state. When the current of the secondary coil 38b ends, a base current starts to flow from the battery 1 to the transistor 33 via the resistor 31, and in response to this, a positive feedback current flows from the tertiary coil 38c to keep the transistor 33 in the ON state. . In this way, the oscillation is repeated and the ignition capacitor 7 is boosted.

In the case of the booster circuit 300, to stop the boosting operation, the on / off operation of the transistor 33 may be stopped. That is, the base current may be kept flowing to the transistor 33 to keep the ON state, or the base current may be bypassed and kept in the OFF state. In the former case, the current continues to flow from the battery 1, which does not meet the purpose of preventing wasteful power consumption. Therefore, the latter method of keeping the off state is adopted.

The ignition signal generating circuit 400 receives a timing signal from the timing sensor 11 and generates an ignition signal (A) (see FIG. 2) at a desired ignition timing based on the timing signal. Thyristor 6 through 5
Is fired. The timing sensor 11 detects a reference crank angle of the internal combustion engine and generates a timing signal.

Next, the configuration of the boost control circuit 500 will be described in detail with reference to FIGS. This boost control circuit 5
Reference numeral 00 includes an oscillation stop circuit 600 for stopping the boosting operation of the booster circuit 300, and a charge monitoring circuit 700 for monitoring the charging voltage of the ignition capacitor 7. The oscillation stop circuit 600 includes a transistor 62, which is turned on by receiving an ignition signal (A) from the ignition signal generation circuit 400 through the diode 60 and the resistor 61. When the ignition signal (A) falls, the transistor 62 turns off. Further, the transistor 62 receives the high-level detection signal (B) from the overvoltage detection circuit 200 and turns on.

When the transistor 62 is turned off, the capacitor 64 is charged through the resistor 63 with a constant time constant to generate a charging voltage (C). Also, this capacitor 6
Reference numeral 4 instantly discharges the transistor 62 when it is turned on to reduce the charging voltage (C). The comparator 65 compares the charging voltage (C) with the set voltage VR1 and generates a comparison output (D). In this case, when the charging voltage (C) is lower than the set voltage VR1, the comparison output (D) becomes high level (hereinafter referred to as Hi). On the other hand, when the charging voltage (C) is higher than the set voltage VR1, the comparison output (D) is at a low level (hereinafter, Lo).
That is).

The OR gate 66 takes the logical sum of the comparison output (D) and the gate output (H) from the AND gate 72, which will be described later, and generates a gate output (I). The transistor 69 is Hi from the OR gate 66 through the resistors 67 and 68.
Is turned on to stop the boosting operation of the booster circuit 300. On the other hand, when the gate output (I) is Lo, the transistor 69 is turned off to start the boosting operation of the booster circuit 300.

The charge monitoring circuit 700 constitutes an essential part of the present invention, and the charge monitoring circuit 700 has a comparator 70. The comparator 70 compares the charging voltage (C) with the set voltage VR2 and generates a comparison output (E). Here, when the charging voltage (C) is higher than the set voltage VR2, the comparison output (E) becomes Hi. On the other hand, when the charging voltage (C) is lower than the set voltage VR2, the comparison output (E) becomes Lo. Further, in order to delay the rising position of the comparison output (E) from the falling position of the comparison output (D) from the comparator 65 in time, the following setting is made.

VR2> VR1 The comparator 71 divides the charging voltage (J) of the ignition capacitor 7 by the voltage dividing resistors 73 and 74 to generate a divided voltage (F).
Is compared with a set voltage VR3 to generate a comparison output (G). In this case, the comparison output (G) becomes Hi when the divided voltage (F) is lower than the set voltage VR3. On the other hand, when the divided voltage (F) is higher than the set voltage VR3, the comparison output (G) becomes Lo. The reason why the voltage of the capacitor 7 is not directly compared but the divided voltage (F) is compared is to protect the withstand voltage of the comparator 71.

As a result, during the time difference specified by VR2> VR1 mentioned above, that is, even with a time delay,
When the ignition capacitor 7 is not charged to the set voltage indicated by the set voltage VR3, it is considered as an abnormality and the booster circuit 3
00 boosting operation is stopped. In the present embodiment, the set voltage corresponds to the minimum value that is acceptable as the normal charging voltage of the ignition capacitor 7 when the comparison output (E) of the comparator 70 rises. The minimum charging voltage of the ignition capacitor 7 which is smaller than the value set for protection against the withstand voltage of the circuit elements such as the ignition capacitor 7 and required for performing the minimum ignition operation is set as the desired voltage. The voltage is set lower than the desired voltage, and is set to a value that can suppress wasteful power consumption of the battery 1 as much as possible.

The AND gate 72 outputs both comparison outputs (E),
The logical product of (G) is taken and generated as a gate output (H). The diode 60 is an element that prevents the detection signal from the overvoltage detection circuit 200 from being input to the ignition thyristor 6. The operation of this embodiment configured as described above will be described. (1) Normal operation mode At time t1 in FIG. 2, when the transistor 62 is turned off by the fall of the ignition signal (A) from the ignition signal generation circuit 400, the charging of the capacitor 64 starts.

Then, at time t2, the capacitor 6
When the charging voltage (C) of No. 4 reaches the set value VR1, the comparison output (D) of the comparator 65 falls to Lo. At this time, since the set value VR2 is larger than the set value VR1, the comparison output (E) of the comparator 70 is Lo. At this time, since the divided voltage of the voltage dividing resistors 73 and 74 is 0, the comparison output (G) of the comparator 71 remains Hi.

Therefore, the logical product of the comparison output (E) and the comparison output (G) of the comparator 71, that is, the AND gate 7
The gate output (H) of 2 becomes Lo. Therefore, the logical sum of this gate output (H) and the comparison output (D) of the comparator 65, that is, the gate output (I) of the OR gate 66 is Lo.
Becomes As a result, the transistor 69 is turned off, and the booster circuit 300 starts the boosting operation based on the constant voltage from the constant voltage power supply 100. At this time, the ignition thyristor 6 is extinguished when the ignition signal (A) falls. Depending on the operating conditions, the arc may not be extinguished at the falling edge (time t1), but if VR1 etc. is set in anticipation of this turn-off delay, the arc can be extinguished by time t2.

Therefore, the ignition capacitor 7 is changed from the step-up transformer 38 of the step-up circuit 300 to the rectifying diode 39.
A boosted voltage is received via the battery to be normally charged and a charging voltage (J) is generated. Along with this, the divided voltage (F) by the voltage dividing resistors 73 and 74 also gradually rises. When the divided voltage (F) reaches the set value VR3 at time t3, the comparison output (G) of the comparator 71 falls to Lo (see FIG. 3). However, at this time, since the comparison output (E) of the comparator 70 is Lo as described above, the logical product of both comparison outputs (E) and (G), that is, the gate output (H) of the AND gate 72 becomes Lo. There is no change (see Fig. 3).

At time t4, when the charging voltage (C) of the capacitor 64 reaches the set value VR2, the comparator 70
The comparison output (E) of (5) rises to Hi (see FIG. 2). However, the comparison output (G) of the comparator 71 has already become Lo at time t3. Therefore, the logical product of both comparison outputs ((E) and (G)), that is, the gate output (H) of the AND gate 72 remains Lo, and the transistor 6
9 continues to be off. Therefore, the booster circuit 300 continues the boosting operation.

At time t5, when the charging voltage (J) of the ignition capacitor 7 reaches the set value Vth, the overvoltage detection circuit responds to the increase in the divided voltage (F) of the voltage dividing resistors 73 and 74 accompanying this. The detection signal (B) of 200 becomes Hi,
The transistor 62 is turned on. Therefore, the capacitor 6
4 is instantly discharged, and its charging voltage (C) becomes Lo.

Therefore, the comparison output (D) of the comparator 65 rises to Hi, and the logical sum of this comparison output (D) and the gate output (H), that is, the gate output (I) of the OR gate 66 becomes Hi. As a result, the transistor 69
Turns on to stop the boosting operation of the booster circuit 300. As a result, the charging voltage (J) of the capacitor 7 becomes constant (strictly, a slight amount is discharged through the voltage dividing resistors 73 and 74), and the divided voltage (F) also becomes constant.

In such a state, at time t6,
When the ignition signal generation circuit 400 generates the ignition signal (A), the ignition thyristor 6 is turned on and the ignition capacitor 7
Are discharged through the primary coil 9a of the ignition coil 9.
Therefore, a high voltage is generated in the secondary coil 9b of the ignition coil 9 to ignite the spark plug 10. Since the time t6 corresponds to the time t0 one cycle before, the operation after the time t0 described above is repeated after the time t6.

Since the time interval from the time t1 to the time t5 is constant, depending on the model, when the engine speed becomes high, the ignition signal (A) is input before the time t5. The ignition operation is performed. Therefore, there may be a case where the charging voltage (F) is not maintained at a constant value. In this case, the charging voltage (J) of the ignition capacitor 7
Becomes lower than the set value Vth on which the overvoltage detection circuit 200 operates, but since the set value Vth is a value for preventing the adverse effect due to the high voltage, the required ignition energy can be supplied even if the set value Vth falls below the set value Vth. .

The time interval from time t0 to time t1 (the time width of the ignition signal (A)) does not always have to be constant, and may change depending on the rotational speed of the internal combustion engine. (2) Operation mode at the time of abnormality When there is a leakage current from the ignition capacitor 7 From time t1 to time t2, the operation mode is the same as the above-mentioned normal operation mode.

At time t2, charging of the ignition capacitor 7 is started in the same manner as described above, but at time t3,
Due to the leakage current of the capacitor 7, the charging voltage (J1) is lower than the charging voltage (J) (see FIG. 3). Therefore, the divided voltage (F1) by the voltage dividing resistors 73 and 74 is the set value VR3.
Output from the comparator 71 (G1)
Remains Hi.

Even at time t4, the divided voltage (F1) does not reach the set value VR3, and the comparison output (G
1) remains Hi (see FIGS. 2 and 3). However, at time t4, the comparison output (E1) of the comparator 70 rises to Hi due to the rise of the charging voltage (C) of the capacitor 64 to the set value VR2, like the comparison output (E) in the normal operation mode. Therefore, the logical product of both comparison outputs (E1) and (G1), that is, the gate output (H1) of the AND gate 72 becomes Hi.

Therefore, the logical sum of this gate output (H1) and the comparison output (D1) of the comparator 65, that is, the gate output (I1) of the OR gate 66 rises to Hi. Therefore, the transistor 69 is turned on to stop the boosting operation of the booster circuit 300. For this reason, the charging voltage (J1) of the ignition capacitor 7 remains constant with insufficient boosting, and the divided voltage (F1) also remains constant with insufficient rising.

Strictly speaking, although there is a slight time delay from time t4 to here, the divided voltage (F1) still has the set value VR3 for a short time (about several tens of μs) from time t4. Does not reach. Therefore, the comparison output (G1) of the comparator 71 remains Hi. At time t5 as well, the charging voltage (J1) of the ignition capacitor 7 remains constant while the boosting is insufficient as described above, and similarly, the divided voltage (F1) also remains constant while insufficiently increasing. For this reason,
The detection signal (B1) from the overvoltage detection circuit 200 remains Lo.

Therefore, the capacitor 64 continues to increase its charging voltage (C1) without being reset and discharged. Therefore, the comparison output (D
1) and (E1) remain Lo and Hi, respectively. Therefore, the logical sum (I1) of the logical products (H1) and (D1) of both comparison outputs (E1) and (G1) remains Hi. As a result, the boosting operation of the booster circuit 300 remains stopped.

At time t6, the ignition signal generation circuit 40
0 generates an ignition signal (A), the overvoltage detection circuit 2
The detection signal (B1) of 00 remains Lo (see FIG. 2). Therefore, the transistor 62 receives the ignition signal (A) from the ignition signal generation circuit 400 via the diode 60 and the resistor 61, is turned on at the rising of this ignition signal (A), and instantly discharges the capacitor 64. As a result, the comparison output (D1) from the comparator 65 rises to Hi, and the comparison output (E1) from the comparator 70 becomes L.
fall to o.

Further, the ignition thyristor 6 is turned on in response to the ignition signal (A). Therefore, the ignition capacitor 7 is discharged, but the discharge voltage is not large enough to ignite the spark plug 10. Therefore, the operation from the time t6, that is, the time t0 is repeated without ignition of the spark plug 10, and the rotational speed of the internal combustion engine decreases. When the rotation speed drops in this way, the time width of one cycle (from time t0 to time t
(Up to 6) becomes longer, the ratio of the time width (time t2 to time t4) in which the booster circuit 300 is operating in one cycle becomes smaller.

If the cause of the leakage current of the ignition capacitor 7 is the reverse recovery delay of the rectifying diode 39 of the booster circuit 300, the higher the temperature, the longer the reverse recovery time. Therefore, if the ratio of the operating time of the booster circuit 300 is lowered as described above, the heat generation of the booster circuit is reduced.
Along with this, the temperature is lowered and the reverse recovery time of the rectifying diode 39 is shortened. Therefore, this rectifying diode 3
The leakage current from 9 is reduced. As a result, the voltage of the ignition capacitor 7 charged within the time from time t2 to time t4 gradually rises.

Thus, at time t10 (time before the time corresponding to time t4), the divided voltage (F1) by the voltage dividing resistors 73 and 74 reaches the set value VR3. Therefore, the comparison output (G1) of the comparator 71, which has been kept Hi for many cycles until this point, falls to Lo here. However, the comparison output (E1) of the comparator 70
Is Lo, this comparison output (E1) and the comparator 7
AND of the comparison output (G1) of 1, that is, the AND gate 72
, Its gate output (H1) remains Lo. Further, the comparison output (D1) of the comparator 65 has already dropped to Lo at time t8 due to the increase in the charging voltage of the capacitor 64.

Therefore, the logical sum of the comparison output (D1) and the gate output (H1), that is, the gate output (I1) of the OR gate 66 remains Lo and the transistor 69 is kept off. As a result, the booster circuit 300 continues its boosting operation. At time t11 (corresponding to time t4), the comparison output (E1) of the comparator 70 rises to Hi, but the comparison output (G1) of the comparator 71 becomes Lo because the divided voltage (F1) rises. Therefore, the gate output (H1) remains Lo, and the booster circuit 300 continues its boosting operation.

At time t12 (corresponding to time t5),
The charging voltage (J1) of the ignition capacitor 7 is the set value Vth.
Does not reach Therefore, the booster circuit 300 continues boosting as it is. Therefore, when the charging voltage (J1) reaches the set value Vth at time t13, the spark plug 10 is ignited. next,
The effectiveness of the present invention will be verified by examining the operation without the charge monitoring circuit 700.

From time t1 to time t3, it is the same as when the charge monitoring circuit 700 is provided. Since there is no comparator 70, there is no comparison output (E) at time t4, and the comparison output (D) of the comparator 65 is L.
It is o. Therefore, the transistor 69 remains off. Therefore, the booster circuit 300 continues its boosting operation.

At time t5, the ignition capacitor 7
Charging voltage (J2) is still lower than the set value Vth.
Therefore, the booster circuit 300 cannot stop its boosting operation and continues. At time t6, the ignition thyristor 6
When is turned on in response to the ignition signal (A) from the ignition signal generation circuit 400, the ignition capacitor 7 is discharged, but its voltage is insufficient to ignite the spark plug 10. Therefore, the spark plug 10 cannot be ignited.

On the other hand, in the boosting operation range of the boosting circuit 300 in this case, compared to the boosting operation range of the boosting circuit 300 in the normal time range from the time t2 to the time t5, the charging voltage (J) is insufficiently increased. Therefore, it increases until time t6. If the cause of the leakage current of the ignition capacitor 7 is the reverse recovery delay of the rectifying diode 39 of the booster circuit 300, the reverse recovery time of the rectifying diode 39 of the booster circuit 300 is longer as the temperature is higher. .

Therefore, the ratio of the boosting operation time of the booster circuit 300 increases, the heat generation of the booster circuit increases, and the temperature rises. As a result, the reverse recovery time of the rectifying diode 39 becomes longer and the leakage current from this diode increases. Therefore, the voltage charged in the ignition capacitor 7 further decreases. As a result, the spark plug 10 cannot be ignited, the rotational speed of the internal combustion engine decreases, and eventually the internal combustion engine is stopped.

In such a state, the ignition signal generating circuit 4
Since the ignition signal (A) is not generated from 00, there is no timing to stop the boosting operation of the booster circuit 300. Therefore, the booster circuit 300 continues to perform the boosting operation. As a result, useless power consumption of the battery 1 is caused. When the rotation of the internal combustion engine is stopped as described above, the rotation of the generator (not shown) that charges the battery 1 is also stopped. Therefore, the battery 1 may continue to be discharged until the ignition switch 2 is turned off, and the battery may eventually run out.

As described above, the charge monitoring circuit 700
If there is not, the voltage of the ignition capacitor 7 is set to the set value Vt.
By reaching h, even if the boosting operation of the booster circuit 300 can be stopped, the boosting operation duration is longer than usual. Therefore, the power consumption of the battery 1 and the booster circuit 3
The heat generation at 00 is large. On the other hand, in the present invention,
Even if the boosting operation of the boosting circuit 300 is permitted by the boosting control circuit 500, if the voltage of the ignition capacitor 7 does not rise normally, the boosting operation of the boosting circuit 300 is based on the above monitoring by the charging monitoring circuit 700. Oscillation stop circuit 600
Will be stopped by. Therefore, the power consumption of the battery 1 is not wasted. Therefore, since the battery of the battery 1 does not run out, when the ambient temperature decreases thereafter,
Normal operation is possible.

Even when the charging voltage of the ignition capacitor 7 does not rise due to the internal leakage of the ignition capacitor 7, the same function and effect as described above can be achieved. When the ignition thyristor erroneously ignites Even when the ignition thyristor 6 erroneously ignites, the divided voltage of the charging voltage of the ignition capacitor 7 falls below the set value VR3. Therefore, the boosting operation of the booster circuit 300 can be stopped. Therefore, the same effect as the above can be achieved. Next, in carrying out the present invention, the same effects as those of the above embodiment can be achieved not only by the above embodiment but also by various modifications as described below.

In the above embodiment, the charge monitoring circuit 700 is
Although the comparators 70 and 71 are used for the configuration, the present invention is not limited to this, and the charge monitoring circuit 700 may be configured using, for example, a microcomputer. Also, the oscillation stop circuit 60
0 may also be configured by, for example, a transistor without using a comparator.

Furthermore, the booster circuit 300 is a self-oscillation type D
The C-DC converter does not have to be a C-DC converter and may be, for example, a separately excited oscillation type. Furthermore, the booster circuit 300 may be configured by a combination of a choke coil and switching means without using a transformer. Further, in the above embodiment, an example in which the present invention is applied to a two-wheeled vehicle has been described, but instead of this, the present invention may be applied to various vehicles such as an automobile and a ship.

Further, in carrying out the present invention, the present invention is not limited to the battery 1, and the present invention may be applied to a capacitive discharge ignition device using an appropriate DC power source as a power source. Each hardware logic configuration of the above embodiment may be realized by each step of the flowchart by the microcomputer.

[Brief description of drawings]

FIG. 1 is an electronic circuit diagram showing an embodiment of the present invention.

FIG. 2 is a time chart showing output waveforms of some of the main components of FIG.

FIG. 3 is a time chart showing output waveforms of the remaining part of the main components of FIG.

[Explanation of symbols]

1 ... Battery, 7 ... Ignition capacitor, 9 ...
-Ignition coil, 10 ... Spark plug, 70 ... Comparator, 300 ... Booster circuit, 600 ... Oscillation stop circuit, 700 ... Charge monitoring circuit.

Claims (2)

[Claims] 1. A boosting means for boosting a DC voltage from a DC power supply, an ignition capacitor charged by the boosting means, and an ignition means for igniting an internal combustion engine by the charging voltage of the capacitor, and Step-up state monitoring means for monitoring the step-up state of the charging voltage to a desired voltage, and step-up operation of the step-up means when the result of monitoring by the step-up state monitoring means is that the charging voltage does not rise to the desired voltage Capacity discharge type ignition device for an internal combustion engine, comprising: a boosting stop means for stopping the engine. 2. The boosting state monitoring means comprises a comparing means for comparing the charging voltage with a set voltage with a predetermined time delay after the charging of the capacitor is started, and the charging voltage is set by the comparing means by the comparing means. 2. The capacity discharge ignition device for an internal combustion engine according to claim 1, wherein the boosting stopping means stops the boosting operation of the boosting means when the voltage is lower than the voltage.