JPS58224573A - Plural spark ignition device - Google Patents

Abstract

PURPOSE:To obtain a large spark energy for ignition by connecting a plurality of thyristors in series with each other, simultaneously triggering the thyristors correspondingly in the independently isolated gate circuits of the same number as the thyristors to automatically oscillate them, thereby increasing the number of discharging repetition. CONSTITUTION:A plurality of spark ignition devices are respectively composed of power source units A and operation units B. The thyristor section of a serial inverter circuit is composed, for example, of two thyristors 6a, 6b in the operation unit B. The thyristors 6a, 6b are respectively simultaneously triggered by exclusive gate circuits 28a, 28b. Each thyristor may be of that having one total number-th of counter withstand voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a self-excited thyristor series inverter type multiple spark ignition device.

FIG. 1 shows a conventional example-3 of this type of ignition device. The details of the operation of each constructor with a symbol in this figure are the same as the constructor with the same symbol (the presence or absence of the suffixes α and b does not need to be considered) in FIG. 2 showing the embodiment of the present invention described later. Therefore, the explanation regarding this example will be referred to.

For this type of conventional device, the basic functional requirement is to increase the discharge energy obtained in the discharge gap g as much as possible, but in addition to this, there is one practical requirement. Therefore, the question is whether it is possible to create a device in which the potential system of the input AC power supply l in the power supply section A can be a low voltage system, for example, a 100V system, or a relatively high voltage system, for example, a 200V system. be.

However, in the conventional device shown in the first diagram, the electrical characteristics, physical dimensions, cost, etc. of each component in the actuating part B are such that it can be used reasonably and without waste for both voltage systems. This could not be provided due to practical constraints. This is due to the following reasons.

The discharge energy or ignition energy obtained in the discharge gap g is proportional to the stored energy E stored in the resonant capacitor r in the operating section B, and this stored energy E is expressed by the following equation.

E=Cψ/2 C: Capacitance ■: Potential between capacitor electrodes Therefore, in order to make the stored energy E1, and therefore the ignition energy, as small as possible, the method of increasing the capacitance, the method of making the applied voltage as small as possible, and, of course, There is a method that combines both.

However, it is impossible to increase the capacitance of the capacitor beyond the specified limit from the practical point of view of this type of ignition device as a commercial product. The discharge current per unit discharge increases, and the current capacity of the thyristor (as a switching element for discharge operation), the primary winding of the ignition coil, etc. must be increased, and of course, the capacitor (g) itself becomes larger. This is because, in the end, the overall size and cost of the device will increase significantly.

All of a sudden, it was decided that consideration should be given to the voltage, and moreover, it would naturally be possible to obtain greater ignition energy with a 200V drive than with a 100V drive. However, this time, the withstand voltage of each component in the operating section B, the recovery time of the switching element, etc. become problems.

Of course, the thyristor t needs to have a high breakdown voltage. For example, when considering a 200V system, a reverse withstand voltage of about 800V is required due to the resonance voltage, and an IKV class one is required for safety. High breakdown voltage products are not only expensive, but also have the disadvantage that recovery time due to carrier accumulation effect is generally several tens of microseconds.
Therefore, it becomes impossible to increase the number of discharges per unit discharge operation or unit time.

For this reason, even though we were able to increase the discharge energy during the first two strokes, the ignition energy, which is evaluated by the total amount of energy during a typical period of time, was ultimately not as high as 0. In fact, for these reasons, this glaze ignition device for the 200V system is hardly ever put into practical use.

On the other hand, let us assume that the operating part B is made for a 200V system using the conventional configuration shown in the first figure, although it has the above-mentioned drawbacks. Then, as it is, according to the previous request,
It can be seen that it would be extremely wasteful to simply change the power supply to 100V considering the application of the 100V system. In other words, from the above formula, to put it simply, there is an inconvenience that the ignition energy is reduced to 1/4, and the withstand voltage of thyristor B is the same as using one that is unnecessarily large. It is.

As described above, the present invention addresses the complicated drawbacks of existing ignition devices of this type, and satisfies the following requirements i) and ii).
It is an object of the present invention to provide a self-excited thyristor series inverter type multiple spark ignition device that satisfies the requirements.

1) Even if it is a relatively high voltage system such as an AC 200■ system, the advantage of increasing the capacitor storage energy due to the high voltage system can be completely achieved without reducing the number of discharges per unit operation. To be able to demonstrate -7-.

11) 100V as a relatively low voltage system as power supply part A
To make it possible to use an operating part B having a satisfactory function as a 200V system as described above without waste and without energy loss even when using a 200V system.

Also, considering the main objectives i) and ii), 2
If it is satisfactory for the 00V system and 100V driving is also acceptable, it is also possible to use it even when a 200V system is applied, that is, to be able to select and use different potential systems. It has as a purpose.

Embodiments of the present invention will be described below with reference to FIG.

First, in the actuating part BK, the thyristor part of the series inverter circuit is composed of a series circuit of a plurality of individual thyristors (in this embodiment, two 6α and j 6').
Each thyristor has a dedicated gate circuit (same (21a,
The two triggers (L and B) are triggered at the same time. In this way, each thyristor can have a reverse withstand voltage as low as the total number of thyristors, and since such a thyristor has a short recovery time, it is possible to maintain a large number of repeated spark discharges.

As will be explained in detail below, each of the dedicated gate circuits Ia and Rb itself may be the same as the conventional gate circuit 2g shown in FIG. 1, or any other existing circuit configuration may be used. The illustrated one is only one example.

In the case shown in the second diagram, the low voltage power supply 1L, which will be described later, is shown by a solid line.
In order to prove operation in a high voltage system such as a 0V system, the power input terminal 3 of the input section consisting of a choke coil 3 and a capacitor≠
The operation when the high-voltage power supply IH (virtual line) of 200 V or the like is connected to 1I and 32 will be explained.

First, during the positive half cycle of the power supply 1H, capacitors /≠α, l≠b are charged from the power supply line /α through resistors 7α and 7b, but the charging voltage is not appropriate. switching element/3α.

2- When the threshold voltage or breakover voltage of t3b is reached,
This switching element becomes conductive and the resistance is α.

The charged charge of the capacitor /pα, l≠b is discharged to the gate of the thyristor 6α, tb via the resistor b, and is used as a trigger current.

When the thyristors 2α, tb are thus conductive at the same time, the resonant inductor j1 becomes the corresponding thyristor 6α, 76.

The resonance capacitor r1 is charged through the path of the power supply line lb. This charging current is the resonant inductor j
When the charging current is reversed, the thyristors tα and tb are turned off in the opposite direction.

Then, the charge stored in the resonant capacitor r is discharged through the primary winding 2/ of the ignition coil, and a high voltage is generated in the secondary winding 3, causing a spark discharge in the discharge gap g. At the same time, a voltage is generated in the feedback winding or the tertiary winding Coco α and Coco B of the ignition coil with the polarity of + and - shown in the figure with respect to the − order winding, but at this time,
This voltage is applied to the Zener diode through the resistor /lα, iB.
70- Since it is short-circuited at /ga and /Ib, thyristor 6α
.

The shadow change does not reach gate 6b. Also, at this point, the previous capacitors lα, l≠b are reliably reset (charge discharged) by turning on the reset transistors /7α, /7b.

Next, due to the resonance between the resonant capacitor l and the primary winding 2/g, the resonant current is reversed and flows into the primary winding as shown in the figure (→,
If a voltage is generated with a polarity of 0, the secondary winding
While a high voltage is generated at the discharge electrode g and a spark discharge occurs, the tertiary winding 2λα and here b also have the polarity (G) and 0 as shown in the figure.
A voltage is generated at , and charges the capacitors /jα, /rb with the illustrated polarity (G) and 0 through the path of the diode l/α, //b, the capacitor /jα, irb, the resistor /2α, and lAb. When the voltage of the tertiary winding becomes zero, the charges accumulated in the capacitors /ra and trb flow into the gates of thyristors +a and H through resistors α and Rb, turning them on. let This operation is repeated thereafter.

In this embodiment, the first thyristor 6α is connected to a series circuit of a resistor 217 (L and a capacitor 2jα) and a resistor: ltα is connected in parallel, and the second thyristor tb is also connected to a resistor 21/Lb and a capacitor in series. Since the series circuit with 2jb and the resistor 2tb are held in parallel to form the surge absorption/balance circuit core α, 27b, even if there is a slight difference in characteristics between the two thyristors used (Aa, Al), The resonant voltage of the resonant capacitor and the resonant inductor j can be equally shared, and the inconvenience of applying a high reverse voltage to only one thyristor can be eliminated.

In this way, a plurality of thyristors (in the illustrated embodiment, two thyristors, but three or more thyristors may be used) are connected in series, and the same number of independently separated gate circuits Jla, 21b, . . .
by each corresponding thyristor lra.

If tb,... are triggered simultaneously to cause self-oscillation, each thyristor will be For example, 5o for tα and tb
The turn-off time is a few microns with low withstand voltage such as ovt+ pressure.
Since a high-speed thyristor of 8 or less can be used and a large number of discharge repetitions can be obtained, a large ignition energy can be obtained without the disadvantages of using a large capacity capacitor as in the conventional case.

Next, in accordance with the objective 11) of the present invention, if such an excellent device that can be used in a high voltage system and has no problem with recovery time can be provided, it is possible to effectively use this device in a low voltage system, such as an IOOV system. Take measures that you can use.

In short, a half-wave voltage doubler circuit 3j is provided at the front stage, and the low voltage power supply 1L is connected to the input terminals 3/ and 3.2 (terminal 32 may be shared with the ground line /b), and the output terminal 33
．． Connect 32 to the high voltage system input terminal string, 3. Similarly, since the three terminals may be ground buses, the connection between the terminals 33 and 3 is actually made via the connection line 36 shown as a virtual line.

In this embodiment, the voltage doubler number n of the half-wave voltage doubler circuit is -, and the half-wave voltage doubler circuit itself has an existing configuration including the capacitor 2 and the diode 30.

If the high voltage line is set to 200V in the above operation, the potential supplied to the actuating part B will be almost the same, so similar operation can be expected. Terminal 3/, 32
When a 100V AC is applied between the terminals 32 and diode 3 during the negative half cycle, especially during the 1/4 cycle,
0. The capacitor 2 is charged with a polarity of -20 in the figure on the path between the capacitor 2 and the terminal 3/, and when the power supply is reversed, this capacitor potential is superimposed on the power supply potential in the figure, and the power supply line /a, This is because approximately the same potential as the 200V system is generated between lb and lb.

After all, according to the present invention, even in a 1ooV system, 200
This means that the actuating part B, which can be assembled as a V system, can be operated without any waste. If the shown connecting line 3t is made removable, the user can selectively use the 100V system or the 200V system. That is, terminals 31-31. If you place t (middle, terminal 3.2 is a common terminal) in a position where the user can easily operate the device, when you want to use the 100V system, terminal -/4t
- After connecting 33, 3≠ with jumper 3t, connect terminal 3/.

It is sufficient to connect the power supply 1L between the lines, or if you want to use a 2ooV system, the terminal 33. Leave the string open and connect terminal 3.
It is only necessary to connect the power supply 1H between the terminals 1 and 32.

As described in detail above, according to the present invention, as this type of ignition device for high voltage systems such as 200 series, which had many problems in the past, the drawbacks have been eliminated and the advantages of high potential have been brought out. It is possible to provide an extremely useful and rational ignition device that can be driven even with a low voltage system such as a 100V system without waste, and it is also possible to select and use both voltage systems rationally. It can have significant effects.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an example of a conventional self-excited thyristor series inverter type multiple spark ignition device, and FIG. 2 is a schematic diagram of an embodiment of the present invention. In the figure, i, IL, and IH are AC power supplies, j is a resonant inductor, B, 6α, and zb are thyristors, and l is a resonant core/
21 is the ignition coil - next winding 1.2
3 is the same secondary winding 1.27α, 27b is a surge absorption/balance circuit, and 21. -"α, -zab are gate circuits for thyristor triggers, 3j is a half-wave voltage doubler circuit, and 37~3≠ are terminals. 3゜Patent applicant Hanshin Elec) IJ Tsuku Co., Ltd.
29 pieces

Claims (2)

[Claims] (1) A self-excited thyristor series inverter type multiple spark ignition device that causes a thyristor series inverter circuit to self-oscillate using an ignition coil as a load, and uses the high voltage generated on the secondary side of the ignition coil to fly multiple sparks between discharge electrodes. In the thyristor series inverter circuit described above, the thyristor is configured by connecting a plurality of individual thyristors in series, each thyristor is triggered simultaneously by a gate circuit dedicated to each thyristor to cause self-oscillation, and an AC power input terminal is connected to the thyristor. A half-wave voltage doubler circuit is provided in the preceding stage, an output terminal of the half-wave voltage doubler circuit is connected to the AC power input terminal, and a power source is connected to the input terminal of the half-wave voltage doubler circuit. One-coil multiple spark igniter. (2) A self-excited thyristor series inverter type multiple spark ignition device that causes a thyristor series inverter circuit to self-excite oscillation using an ignition coil as a load, and sends multiple sparks between discharge electrodes using the high voltage generated on the secondary side of the ignition coil. In this case, the thyristor in the thyristor series inverter circuit is configured by connecting a plurality of individual thyristors in series, and each thyristor is simultaneously triggered by a gate circuit dedicated to each thyristor to cause self-oscillation, and an AC power source is used. A multi-spark ignition device characterized in that a half-wave voltage doubler circuit is provided upstream of the input terminal, and an output terminal of the half-wave voltage doubler circuit is removably connected to the AC power input terminal.