JPH07103121A - Ignition device for engine - Google Patents

Abstract

PURPOSE:To ignite and burn fuel securely and increase combustion efficiency by providing a power unit to convert AC power into three-phase AC, an ignition plug with three-electrode, and an ignition coil for three-phase, and also using multiple arc ignition. CONSTITUTION:Since an induced electromotive force is produced in reactance circuits 422a to 422c when one of switch circuits 421a to 421c is switched over by a switch control circuit 403 at a specified timing, a sawtooth current with drooping characteristics at a specified cycle is induced at output terminals 406a to 406c of a transforming part relative to a neutral terminal 407. When the electromotive force for all three-phase is produced by the switch control circuit 403 with a phase difference of 1/3 for each cycle, a three-phase AC current is outputted to the output terminals 406a to 406c relative to the neutral terminal 407. Then the AC output of each phase is applied to the primary side of an ignition coil for each phase, and the secondary output is connected to each electrode of an ignition plug to generate ignition arc and ignite fuel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine ignition device, and more particularly to an ignition device for a multi-arc system, which greatly improves combustion efficiency.

[0002]

2. Description of the Related Art In recent years, in automobiles, optimal control of ignition timing and fuel injection amount, optimization of air-fuel ratio and compression ratio, etc. have been carried out from the viewpoint of improving the combustibility in the engine. From the same point of view, improvements have been made to ignition devices such as spark plugs and ignition coils.

FIG. 8 shows an ignition device for a conventional general gasoline vehicle. FIG. 8 (a) is a circuit configuration diagram of the ignition device, and FIG. 8 (b) shows a closed magnetic circuit type iron core of an ignition coil. Fig. 8 (c) is a diagram showing an open magnetic circuit type iron core of an ignition coil, and Fig. 8 (d) is a diagram showing a cross-sectional structure of an ignition plug. In the figure, 10 is an ignition coil, which is formed by winding a primary coil 12 and a secondary coil 13 around a closed magnetic circuit type iron core 71. 1 above
One end of the next coil 12 is grounded via the drive transistor 14, and the base of the transistor 14 is connected to the control circuit 15. The control circuit 15 is configured to control ignition of the ignition coil 10 in synchronization with engine rotation. In addition, the secondary coil 1
One end of 3 is connected to the central electrode 73 of the spark plug 72. The other ends of the primary coil 12 and the secondary coil 13 are commonly connected, and the common connection point is connected to the ignition switch 30 via a current adjusting resistor 16. Further, the other end of the ignition switch 30 is connected to the battery 40.

Here, 50 is an ignition switch 30.
A starter 31 for rotating the engine at the time of start-up, which is connected between the control circuit 15 and the ground, is connected in parallel with the current limiting resistor 16 and short-circuits both ends of the resistor 16 at the time of start-up by the signal from the control circuit 15. This is a circuit, and the short-circuit current of the ignition coil can be increased by this short circuit. Further, 17 is a stray capacitance existing on the secondary side of the ignition coil 10, which serves as a trigger for arc discharge in the spark plug.

In addition to the closed magnetic circuit type iron core shown in FIG. 8B, an open magnetic circuit type iron core 76 shown in FIG. 8C is used as the iron core.
This iron core is composed of an iron core portion 76a for winding a coil and an outer frame case 76b of the iron core portion 76a. Here, the outer frame case 76b is also used as a magnetic path. are doing.

Next, the operation will be described. When the ignition switch 30 is turned on, the ignition device is supplied with power from the battery 40, and when the ignition switch 30 drives the starter 50 to rotate the engine, the ignition coil 10 causes the control circuit 15 to operate.
ON / OFF control is performed in synchronization with the engine rotation. At this time, the stray capacitance 17 is charged by the high voltage generated in the secondary coil of the ignition coil 10,
These high voltages are supplied to the spark plug 72, and an arc is continuously generated in the cylinder.

At this time, the high voltage waveform on the secondary side of the ignition coil 10 is a stray capacitance 17 in the initial minute period Y as shown by the alternate long and short dash line S1 in FIGS. 1 (e) and 1 (f).
Due to the action of, the peak level rises sharply to V _{1 and} then immediately drops to a predetermined level V ₂ and then slowly decays in the decay period X (waveform flat portion). In addition,
a _p is the rise time.

FIG. 9 (a) shows a circuit configuration of another conventional ignition device for an engine. In this configuration, the ignition plugs 7 of two cylinders are connected in series to the ignition coil 10.
6, 77 and the diode 101 are connected, and two ignition plugs are operated by one ignition coil. Here, it is assumed that the two cylinders are the first, third, or second, and fourth cylinders whose strokes are offset by 180 ° in a four-cylinder engine. The other structure is the same as that shown in FIG.

In such a circuit configuration, the spark plugs are simultaneously sparked in the cylinder in the exhaust process and the cylinder in the compression process. However, since the cylinder in the exhaust process has a small air pressure, it is easily discharged and the circuit is formed. Resistance can be ignored, and it does not explode because it is an exhaust process. In the spark plug of the cylinder in one compression process, an arc is generated in the spark plug on the exhaust side to form a discharge circuit.Therefore, the arc is generated with a momentary delay, but it is in the process of compression ignition and an explosion occurs, causing an engine Operates automatically.

However, in the above-mentioned ignition device, the arc discharge due to the stray capacitance is in an extremely short time of the order of 10 ^-6 seconds, and the portion that is actually effective for igniting gasoline is the flat portion X of the waveform having a small energy. That is, the voltage of this part is 300-500V and the period is 2/10
Since it was around 00 seconds, the ignition of gasoline was not enough. For this reason, the combustion efficiency of gasoline is currently in the low 30% range, and less than 70% is incomplete combustion that pollutes the air as exhaust gas. Moreover, the combustion efficiency is poor, so there is not enough power for gasoline consumption. There was a problem.

The iron core 7 of the ignition coil is also
1 is the width W _C of the central leg 71a and the side legs 71b on both sides,
The width W _{S of the} 71c is of the same type or has a large loss, which is an open magnetic circuit type, that is, there is a large loss in the cross-sectional area and the magnetic path thereof. Therefore, there is a problem that a loss occurs due to the above reasons, and in this case, the number of turns of the coil must be increased, which causes an unreasonable increase in rising time. Further, a gap is formed in a part of the central leg 71a to form a magnetic flux leakage type arc generator.

Further, in the above-mentioned conventional spark plug 72, the tip portion 75a of the ground electrode 75 is located at the tip portion 73 of the central electrode 73.
Since it is located so as to cover over a, the ground electrode tip 75a blocks the spread of the sparked arc F as shown in Fig. 9 (b), and the ignition of the fuel in the shadowed part. There was a problem that was delayed or insufficient. Here, E is the peripheral wall of the engine.

Further, in the structure in which two ignition plugs are ignited by one ignition coil, sparks of the ignition plugs in the exhaust process may cause ignition explosion in the compression process, but useless arc generation in the cylinder in the exhaust process. Therefore, there is a drawback that the life of the spark plug is shortened.

In order to solve these problems, the inventor of the present application can dramatically improve the fuel efficiency of the engine from the conventional value of about 30%, improve the fuel efficiency and reduce the exhaust gas. Invented an engine ignition device that can be used, and has already filed an application (Japanese Patent Application No. 2-23811).
No. 8).

This is provided with a waveform processing circuit between the secondary side of the ignition coil and the spark plug, the rising peak of the secondary side high voltage waveform is suppressed, and the energy corresponding to the suppressed amount is described above. It is made to move to a smoothly decaying flat waveform portion following the rising peak so that this flat waveform portion has a long waveform, which increases the time during which the arc of the spark plug contributes to ignition of the fuel, and The energy of the arc will increase, and as a result, combustion in the engine will be sufficiently and reliably performed, which will dramatically improve the fuel efficiency in the engine, increase the engine output and reduce fuel consumption and exhaust gas. It can solve problems.

Further, the ignition coil uses a completely closed magnetic circuit type iron core in which the cross-sectional area of the central leg is set to be approximately twice the cross-sectional area of both side legs, whereby the magnetic flux is overcrowded in the central leg. It does not enter into a state, efficiently generates a high voltage, and can prevent heat generation in the iron core. Further, since the completely closed magnetic circuit type iron core has a structure with no gap, the number of turns of the primary and secondary windings can be greatly reduced, and magnetic flux leakage does not occur unnecessarily. As a result, the magnetic flux generated in the iron core effectively contributes to electromagnetic conversion, and energy loss in the iron core can be reduced. Moreover, since the number of turns is small, the impedance can be reduced, and the rise time is short, which is advantageous for speeding up. Further, it is possible to suppress the energy of wasteful discharge in a short time of 10 ⁻⁶ to 10 ⁻⁹ seconds due to the stray capacitance.

Further, the center electrode and the ground electrode of the spark plug are constructed such that the tips of both electrodes are included in a plane perpendicular to the normal to the inner wall surface of the cylinder at the mounting position of the spark plug. As described above, the sparked arc is evenly spread in the cylinder without disturbing the spread of the ignition core, and the fuel can be ignited quickly and sufficiently, thereby improving the combustion efficiency.

Further, a high voltage is generated at the secondary side of the ignition coil by inverting its polarity at a predetermined timing.
The two spark plugs are each sparked by a high voltage of a predetermined polarity, so that the two spark plugs do not spark at the same time, that is, in the cylinder in the exhaust process accompanying spark in the cylinder in the explosive process. The spark disappears, and sparks are generated only in the explosion process of each cylinder, which can suppress the consumption of the spark plug.

[0019]

The present invention is made by further developing the invention according to the above-mentioned prior application, and it is possible to ignite fuel in the engine quickly, reliably, and sufficiently, and to combust the engine. It is an object of the present invention to obtain an engine ignition device capable of dramatically improving the efficiency.

[0020]

An engine ignition device according to the present invention is a DC-3 phase conversion power supply device (Japanese Patent Application No. 2-288878) developed by the present inventor for converting DC into three phases.
No.), a spark plug device in which spark plugs of 3 electrodes or 6 electrodes are arranged at 120 ° intervals or 60 ° intervals with their tips close to each other, and an ignition circuit including ignition coils for 3 phases, Multi-arc ignition is performed by applying a three-phase voltage to the three electrodes or the six electrodes.

In the engine ignition device according to the present invention, the secondary high voltage waveform of the ignition coil is suppressed in its rising peak, and the suppressed energy is smoothly attenuated following the rising peak. The waveform is made to have a longer flat portion by shifting the waveform to.

Further, in the engine ignition device according to the present invention, the high voltage waveform on the secondary side of the ignition coil is
This is a superimposed voltage waveform of a rectangular low voltage and a steep pulse wave voltage having a very high peak voltage.

In the engine ignition device according to the present invention, the secondary-side high voltage waveform of the ignition coil has a low-voltage rectangular output waveform with a slight rising edge and a steep, peak-like rising edge slightly advanced from the waveform. It is a superposed wave with a pulse wave voltage having a very high voltage.

[0024]

According to the present invention, the spark plug has a three-electrode or six-electrode configuration, and a three-phase voltage is applied to the three-electrode or the six-electrode to generate a multi-arc between these electrodes so that ignition is performed. Therefore, an arc is blown between the three electrodes or the six electrodes, and a powerful multi-arc flame is generated in the engine, so that extremely efficient combustion is performed. In this case, as compared with the conventional ignition method, it is possible to rationally generate an arc, the arc time can be adjusted for both long and short, and because there is a rotating magnetic field, the power of the arc and the combustion efficiency are increased. is there.

Further, in the present invention, the high voltage waveform on the secondary side of the ignition coil is suppressed in its rising peak, and the suppressed energy is transferred to a flat portion of the waveform which smoothly attenuates following the rising peak. Since the flat portion of the waveform has a long waveform, the arc plug energy contributes to the ignition of the fuel, and the arc energy increases, so that the combustion efficiency can be dramatically increased.

In the present invention, the high voltage waveform on the secondary side of the ignition coil is a rectangular low voltage,
Since the superimposed voltage waveform with the steep pulse wave voltage with a very high peak voltage is used, a waveform similar to the one described above suitable for ignition can be obtained with a simple configuration, and combustion efficiency is also dramatically improved. Can increase.

Further, in the present invention, the secondary high voltage waveform of the ignition coil is a low voltage rectangular output waveform having a slight slope of rising and a steep rising peak voltage slightly advanced from the waveform and having a very high peak voltage. Since the wave is superimposed on the pulse wave voltage, the fuel can be ignited and burned more efficiently, and the combustion efficiency can be dramatically increased.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The configuration of the engine ignition device according to the embodiment of the present invention is roughly divided into the configuration of the engine ignition circuit system, the configuration of the power supply device that forms a three-phase power source from the DC power source, and the configuration of the ignition plug including three electrodes. And a multi-arc system configured to generate a multi-arc by applying a phase power supply.

(I) First, the structure of the ignition circuit system of the engine will be described. FIG. 1 shows the configuration of one phase of an ignition device for an engine of a gasoline automobile according to one embodiment of the present invention, and FIG. 1 (a) is a configuration diagram of an ignition circuit system for one phase, FIG. 1 (b).
Shows the iron core of the ignition coil, Fig. 1 (c),
(d) is a diagram showing a sectional structure and a planar arrangement of the spark plug, and FIGS. 1 (e) and 1 (f) are waveform diagrams for explaining the operation.

In FIG. 1 (a), the same reference numerals as those in FIG. 8 (a) indicate the same or corresponding portions, and 60 is the ignition coil 1
The ignition coil 10 is provided with a waveform processing circuit that suppresses the rising peak of the secondary high voltage of 0, adds the suppressed energy to the waveform flat portion where the waveform is smoothly attenuated, and extends the waveform flat portion. One end of the secondary coil 13 is connected to the electrode 21 of the spark plug 20 via the waveform processing circuit 60. Reference numeral 61 is a first series-connected body that constitutes the circuit 60, and includes a first resistor 61a and a first resistor 61a.
The coil 61b is connected in series. Reference numeral 62 is a second series connection body, which is formed by connecting the first capacitor 62a, the second resistor 62b, and the second coil 62c in series.
It is connected in parallel with the first series connection body 61. Reference numeral 63 is a second capacitor connected in parallel with the first series connection body 61 and having a considerably smaller capacity than the first capacitor 62a.

FIG. 1B shows the ignition coil 10 described above.
The core 11 is of a closed magnetic circuit type, and the width W _CO of the central leg 11a thereof is the left and right side legs 11.
b, than the width W _S of 11c has a nearly 2-fold, or central leg 11a has approximately twice the cross-sectional area of the side legs 11b, 11c.

FIG. 1 (c) shows a cross-sectional structure of the above-mentioned spark plug. Reference numerals 21a, 21b, and 21c are metal core materials serving as electrodes, each of which is covered with an insulating member 22 such as ceramic. Insulated from each other. These 3
The two electrode rods 21a, 21b, 21c are arranged so that their tips are close to each other so that an arc can be generated between them, and when viewed from a plane as shown in FIG. It is arranged so as to be located on the conical side surface at intervals. 23 is attached to the insulating member 22,
It is a metal member having a screw portion 24 for attaching to a cylinder.

First, the operation of the ignition circuit for one phase will be described. After turning on the ignition switch 30,
Since the operation until the engine is in the automatic operation state is the same as the conventional one, it is omitted. Here, the operation of the waveform processing circuit 60 for processing the high voltage waveform on the secondary side of the ignition coil 10 will be described.

First, when a high voltage is supplied from the secondary coil 13 of the ignition coil 10 to the waveform processing circuit 60, the second capacitor 63 is charged to the high voltage in a relatively short time and the voltage is ignited. 21. At this time, the first capacitor 62a having a larger capacity than the second capacitor 63 is gradually charged by the action of the second resistor 62b and the second coil 62c. Further, in the first series-connected body 61, the first coil 61b suppresses the sharp rising peak of the high voltage generated in the secondary coil 13 of the ignition coil to prevent the ignition plug 20 from being damaged.
Supply the next voltage.

Due to the operation of the waveform processing circuit 60, the shape of the rising portion of the secondary voltage has a peak level of V ₁ (20,000) as shown by the solid line S0 in FIGS. 1 (e) and 1 (f). From several thousand volts) to V ₀ (10,000 thousand volts), and the iron core of the ignition coil has a small number of turns,
Moreover, since it is a highly efficient completely closed magnetic circuit type, a large amount of energy rises more steeply, and since the waveform has a drooping characteristic, the energy for forming a gasoline ignition nucleus becomes larger. Here, a ₁ is the rise time, which is shorter than the conventional a _P.

In the process in which the waveform rises and then decays, the electric charge stored in the large-capacity first capacitor 62a is first discharged, and then the first and second coils 61b are discharged. , 62c, the current supply at a constant level is extended. Therefore, the waveform flat portion X ₀ where the waveform is smoothly attenuated, that is, the portion that contributes to combustion has a large energy and a long duration as compared with the conventional X, as shown in FIG. As a result, an arc having such a waveform is generated in the cylinder.

As described above, in this circuit, the waveform processing circuit 60 is provided between the secondary coil 13 of the ignition coil 10 and the ignition plug 20, and the waveform processing circuit 60 is provided.
Since the peak of the next-side high-voltage waveform is suppressed and the energy corresponding to that peak is added to the smoothly flattened waveform flat portion following the rising peak, the duration of the waveform and the energy at the flat waveform portion are increased. As the duration of the arc in the cylinder increases, the spark becomes stronger. Further, since the first and second series connection bodies 61 and 62 of the waveform processing circuit 60 include the coils, the arc can have a drooping characteristic, and the ignition time and the ignition nucleus forming energy can be increased. It is possible to ensure ignition at high engine speeds. As a result, the fuel is ignited reliably and sufficiently regardless of the low speed or high speed rotation state of the engine, which increases the combustion efficiency and reduces the gas of incomplete combustion. Although the waveform processing circuit has been described as the most easy-to-understand LC circuit, arc generation can be performed in a rational method that includes drooping characteristics in circuits that include other semiconductors, so that the ignition nucleus formation energy is increased. You can do this.

Also, in this circuit, the ignition coil 1
No. 0 iron core 11 with its central leg 11a having side legs 11b, 11
Since the structure has a cross-sectional area about twice that of c and no gap, the ignition coil can be an efficient transformer. That is, the magnetic resistance as a transformer is significantly reduced, and the number of lines of magnetic force generated is increased. Furthermore, the saturation current is increased, the number of turns of the primary coil is less than one-third that of the conventional type, and the number of turns of the secondary coil can be reduced by nearly 30% of the conventional type. Can be generated. Further, by reducing the number of turns in this way, the time constant L / R becomes smaller, the rise becomes steeper, and the change in current over time becomes larger, so that the certainty of fuel ignition in a high speed state can be increased.

The spark plug 20 is connected to the three electrodes 21.
Since the tips of a, 21b, and 21c are arranged close to each other, the ground electrode does not block the spread of the arc when an arc occurs as in the conventional case, and the shadow portion of the spark does not occur in the cylinder. . Therefore, the certainty of ignition can be improved also by this. The fact that a strong arc is generated by the multi-arc and reliable ignition and combustion are performed will be described later in detail.

In the above embodiment, the battery voltage of 12 V is supplied to the primary side of the ignition coil as it is, but this is as shown in FIG. It is also possible to provide a diode rotor type booster circuit 70 between the booster circuit 40 and 40 to boost a voltage of 12 volts to about 400 volts and supply such a high voltage to the primary coil. In this case, the load on the ignition coil is lightened, so that the number of turns of the coil can be reduced, and a lightweight, compact and high-performance ignition coil can be provided.

The waveform processing circuit is not limited to the one shown in FIG. 1 (a), but in principle, as shown in FIG. 2 (a), a capacitive component 60a for delaying the secondary side high voltage waveform is provided. When,
Any circuit configuration may be used in which an inductive component 60b that suppresses the rising peak and has a drooping characteristic and a resistance component 60c that attenuates the current are connected in parallel with each other.

However, a circuit 65 having no inductive component as shown in FIG. 2 (c) can also be used in some cases. In this circuit, the second series connection body 62 is composed of a first capacitor 62a having a large capacitance and a second resistor 62b, and the series resistor 62 has a first resistor 61 and a second capacitor 63 having a small capacitance. And are both connected in parallel.

In this case, it is not expected that the arc will have drooping characteristics, but the rising peak of the high voltage generated on the secondary side of the ignition coil can be suppressed to increase the energy in the waveform flattening portion and the waveform flattening portion. The effect that the part can be extended is obtained.

Further, in the first embodiment, the capacitor L and the coil are connected in parallel in parallel with the spark plug.
A C circuit may be connected, in which case the magnetostriction resonance or resonance phenomenon can be used to further increase the duration of the arc.

FIG. 2D is a diagram for explaining the engine ignition device according to the second embodiment of the present invention. Here, the waveform processing circuit 60 and the spark plug 20 in the circuit configuration of the first embodiment are used. And an additional resistor 6 connected in series between the electrode 2 and the electrode 2 of the spark plug 20.
It is incorporated in a part of 1. The other structure is the same as that of the first embodiment.

In this case, the additional resistor 6 has the effect of reducing electromagnetic noise and increasing the arc duration.

(II) Next, the configuration of the power supply device will be described. In order to obtain a three-phase alternating current from a battery such as a 12V mounted on an automobile, the power supply device described in Japanese Patent Application No. 2-288878 developed by the present inventor and already applied is used.

FIG. 4 (a) shows the configuration of this DC-to-three-phase AC conversion power supply device, and FIG. 4 (b) shows its output waveform. In the figure, 401 is a DC power supply, and 402 is DC power to AC power. A conversion unit for converting, having positive and negative contacts 424a to 424c connected to the positive and negative voltages of the DC power supply 401,
Switch circuits 421a to 421c capable of turning on and off the positive and negative contacts or switching between the positive and negative contacts.
And reactance circuits 422a to 422c connected to the switch circuit 421. Also 406a-40
6c is an output terminal of the conversion unit 402.

Reference numeral 403 is a control circuit for switching and controlling each switch circuit with a phase difference (1 / 3T ₀ ) of 1/3 of the switching cycle T ₀ of the switch circuit 421.

Next, the operation will be described. First consider only one phase. When the switching operation of one switch circuit 421 is performed by the control circuit 403 at a predetermined timing, an induced electromotive force is generated in the reactance circuit 422, which causes the output terminal 406 with respect to the neutral terminal 407 as shown in FIG. As shown in, a sawtooth current having a drooping characteristic of a predetermined period is induced. Then, this is controlled by the control circuit 403 for one cycle T ₀ for all three phases.
With a phase difference of 1/3 (1 / 3T ₀ ) of each of the output terminals 406a to 406c, the neutral electrode 407 is provided.
On the other hand, a three-phase alternating current as shown in Fig. 4 (b) is output. Here, the shape of the drooping characteristic of the three-phase output, that is, the degree of the slowing speed of the falling edge is determined by the reactance circuits 422a to 422c.
It can be changed by changing the value of the inductance of, and an output close to a rectangular wave can be obtained.

(III) Next, the structure of the multi-arc system will be described. Multi-arc is 3 or 6 etc.
N (N is an integer) electrodes are arranged on the side surface of the cone at equal intervals such as 120 ° intervals, 60 ° intervals, etc., with their tips close to each other. It is possible to generate multiple arc discharges between the electrode tips by applying each phase voltage, and to generate a very powerful multi-arc flame as a whole, which is very useful in the field of welding, etc. It has a powerful effect. This multi-arc is an invention of the present inventor.
3-32353, Japanese Patent Publication No. 53-39377, Japanese Patent Publication No. 54
-41551, Japanese Patent Publication No. 55-49950, Japanese Patent Publication No. 55-
51670, Japanese Patent Publication No. 56-18312, Japanese Patent Publication No. 56-3
0113, JP-B-56-31184, JP-B-56-31
186, Japanese Patent Publication No. 56-31188, Japanese Patent Publication No. 56-496
65, Japanese Patent Publication 57-5626, Japanese Patent Publication 57-5627,
It is disclosed in JP-B-57-52149, JP-B-60-13438, JP-B-52-65119, JP-A-63-130269, JP-A-64-2293, JP-A-64-73066 and the like.

The present invention uses this multi-arc to ignite a spark plug, and the configuration of the multi-arc system is shown in FIG. As shown in Fig. 3 (a), three-phase AC power supply 3
Outputs 300a, 300b, 300c of 00 are three electrodes 301 whose tips are arranged close to each other at 120 ° intervals,
When applied to each of 302 and 303, each adjacent electrode 3
Three arcs are generated between 01, 302 and 303, and a very powerful multi-arc flame is obtained as a whole.
As shown in FIG. 3 (b), six electrodes 301 to 306 are arranged at 60 ° intervals with their tips close to each other, and a pair of electrodes facing each other have three phases of each phase a. ，
When the outputs b and c are applied, a total of 6 arcs are generated between the electrodes, and a powerful multi-arc flame is obtained. See also FIG.
As shown in (c), the three-phase power source 300 may have a Y-connection structure, a neutral electrode 307 may be provided in addition to the above-mentioned six electrodes, and this may be connected to the Y-connection neutral. 6 arcs, and 6 arcs between each electrode and the neutral electrode, a total of 12 arcs can be obtained, and a more powerful arc flame can be obtained.

A six-phase power source may be constructed on the same principle as that of the three-phase power source, and each phase voltage may be applied to each of the six electrodes. In this case as well, six neutral electrodes are provided between each electrode. If provided, a total of 12 arcs can be obtained, and a very strong arc flame can be obtained.

In any of the above examples, the tips of the electrodes are arranged close to each other, so that the three, six, or twelve arcs are fused to form an integral arc atmosphere. Is. Further main features of this multi-arc are as follows.

(1) Since a rotating magnetic field is generated at the tip of the electrode, an electric stirring action on fuel can be expected. (2) It is possible to increase the number of phases and electrodes by a multiple of 3. (3) Multi-phase AC such as 3-phase and 6-phase is used, the total current of each phase is always 0, and the ground wire is not required. However, a stronger arc can be generated by providing the neutral electrode in the central portion of the plurality of electrodes as described above.

The present invention uses this multi-arc to ignite a spark plug in an engine, and its constitution is from a battery 401 mounted in an automobile to a three-phase AC output 406a to 406c (from a battery 401 shown in FIG. Figure 4
(a waveform shown in (b)), while the configuration of the ignition circuit of FIG. 1 (a) is provided for three phases except for the power source 40 and the ignition plug 20, and the AC outputs 406a to 406c of the above phases are provided for each phase. It is applied to the primary side of the ignition coil 10, and the secondary side output is applied to each electrode 21a of the spark plug 20 shown in FIGS. 1 (c) and 1 (d).
By connecting to 21b and 21c, an ignition arc is generated between each electrode of the spark plug and another electrode or a neutral electrode to ignite the fuel. This is a conventional single phase, direct current ignition method. In comparison with the above, the following effects can be obtained.

(1) Since the three-phase alternating current is used, the arc generation time can be tripled and the fuel can be ignited and burned sufficiently. (2) Since the power supply device used is one that obtains three-phase alternating current from the DC power supply using the inverter method, the arc time can be shortened or shortened by adjusting the output waveform (output time) of the power supply device. Can be adjusted. (3) Since a three-phase alternating current is applied to three or six electrodes arranged at 120 ° intervals and 60 ° intervals, a rotating magnetic field is generated near the tip of the electrode rod, stirring the surrounding fuel. Since it activates the fuel, there is an effect that the fuel can be ignited and burned more sufficiently.

Therefore, the engine ignition device of the embodiment of the present invention is equipped with a power supply device for converting DC power into three-phase AC, an ignition plug having three electrodes or six electrodes, and three-phase ignition coils. By using multi-arc ignition for ignition, the ignition time can be extended to about 3 times longer than in the case of single phase, ignition and combustion can be performed more reliably, and combustion efficiency is dramatically improved. In addition to being able to greatly improve fuel efficiency, it is also possible to greatly reduce harmful components of exhaust gas.

Further, since the secondary side high voltage waveform of the ignition coil has a waveform in which a pulse wave portion having a steep rising edge and a flat portion having a low voltage and a long duration are superposed, the sustaining time of combustion following ignition is sufficient. Therefore, there is an effect that the combustion efficiency can be greatly improved.

(I-2) Next, the ignition coil 2
On the next side, for the same purpose as the above-mentioned embodiment, a steep rise,
Another embodiment of the present invention will be described in which a superposed wave of a pulse voltage having a very high peak voltage and a low voltage rectangular output for sustaining discharge is generated.

FIG. 5 shows a waveform obtained on the secondary side of the ignition coil in another embodiment of the present invention, and a configuration for obtaining the waveform. In FIG. 5 (a), 500A,
500B is a transformer, 512A and 512B are primary coils of ignition coils of A transformer and B transformer, both of which have 100 turns, and an applied voltage is 4V.
513A and 513B are secondary coils of the ignition coil, which have 2000 turns and 600 turns, respectively.
The output voltage is a breakdown voltage of 10,000 V produced when the ignition circuit is turned off, and a sustain voltage of 60 V produced when a constant current is flowing. Here, the number of turns of the coil changes depending on the structure of the plug such as the gap between the electrodes. Reference numeral 501 is a phase advancing capacitor provided on the primary side of the A transformer side, and 502 is a delaying phase inductance provided on the primary side of the B transformer side. Reference numeral 503 is a delay phase inductance provided on the secondary side of the A transformer for imparting a drooping characteristic to the fall of the dielectric breakdown voltage. Reference numeral 504 is a delay phase inductance provided on the secondary side of the B transformer for providing a falling characteristic of the sustain voltage. 505 is a timer switch which is provided on the primary side of the A transformer side and turns off 1.5 / 1000 seconds after the reference time t ₀ , and 506 is provided on the primary side of the B transformer side, which is 6 from the reference time t _0. A timer switch that turns off after 1000 seconds. 514 is a spark gap of the spark plug, and both coils 513A and 513B are connected in parallel to this.

In FIG. 5 (c), reference numeral 520 is a pulse wave generated by the A transformer for breaking the air insulation having a peak value of 10,000 V, and its rising time is 1% from the reference time t ₀ by the phase advancing capacitor 501. / 1000 seconds before, the slope of the fall has a slight slope due to the inductance 503, and the pulse time after t ₀ is 1.5 / 1000 seconds by the timer switch 505, and the total pulse time is about
It is 2.5 / 1000 seconds. 521 is an arc maintaining voltage of a voltage value of 60 V generated by the B transformer, which is generated at time t ₀ , has a slight slope at the rising edge by the inductances 502 and 504, and has a total of about 6/1000 seconds by the timer switch 506. It is supposed to have a pulse time.

FIG. 5 (d) shows the ignition pulse waveforms for the entire three phases. In FIG. 5 (d), the frequency of the three-phase AC is 200
This is a cycle, and three waveforms shown in Fig. 5 (c) are generated every 1.67 / 1000 seconds.

FIG. 5 (e) shows an ignition pulse waveform in the case of a 6-phase 6-electrode. In the figure, the frequency of the 6-phase AC is 200 cycles, and the waveform of FIG. 5 (c) is 0.83 / 1000. Six are generated every second.

The other construction of the ignition circuit of the second embodiment is similar to that of the circuit of FIG. 1A except that the waveform processing circuit 60 of FIG. 1A is unnecessary. Further, in the present embodiment, the configurations of the spark plug and the power supply device are the same as those in the first embodiment.

In this embodiment, the capacitor 50 is provided on the secondary side of the ignition coil of the A transformer.
1, the phase is advanced by 1/1000 second, and when the primary coil of the ignition coil is turned off, it instantly rises to a peak value of 10,000 V, and its falling edge is slightly sloped by the inductance 503. After 1.5 / 1000 seconds, the timer switch Fifty
5, an arc 520 for breaking the air insulation which is completely disconnected by 5, and an inductance 502, which rises at t ₀ ,
504 has a slight slope, and the ignition coil turns ratio is 40 turns: 600 turns, and the peak value is 60.
Fig. 5 (c), which has V and is superposed with the arc maintaining voltage that is turned off after 6/1000 seconds by the timer switch 506.
The waveform shown in is obtained. Moreover, since this has a multi-arc ignition configuration, the waveform of the ignition pulse in the ignition plug is three continuous waveforms as shown in FIG. 5 (d). Further, in the case of the 6-phase 6-electrode configuration, it corresponds to a 6-phase power supply waveform (not shown), and as shown in FIG. Therefore, as in the case of the waveform processing circuit 60 of the first embodiment, the above-mentioned superposed waveform allows the combustion voltage after ignition to be reliably and sufficiently obtained by ensuring a sufficient sustaining voltage after arc generation. With the multi-arc ignition configuration, the effective arc power is further increased, and the effect of dramatically improving combustion efficiency can be obtained.

FIG. 5B shows a circuit configuration in which the primary side of FIG. 5A is common. In the figure, the same reference numerals indicate corresponding parts, and 507 corresponds to the control circuit 15 of FIG. 1A, and is an ignition control switch for controlling ignition of the ignition coil in synchronization with engine rotation. In addition, in FIG.
It suffices to provide only one of 01 and 502 and 503 and 504.

6A and 6B show a spark plug having a 6-electrode structure according to another embodiment of the present invention. FIG. 6A is a sectional view and FIG. 6B is a plan view. In the figure, 601 to 606 are electrodes, 608 is an insulating member such as ceramic, and 609 is the insulating member 6.
No. 08 is a metallic member having a threaded portion 610 for attaching to the cylinder, which is attached to No. 08.

FIG. 7 shows a spark plug having a 7-electrode structure in which a neutral electrode is added to the 6-electrode according to still another embodiment of the present invention, (a) is a sectional view and (b) is a plan view. In the figure, reference numeral 607 is a neutral electrode, and other reference numerals are exactly the same as those in FIG.

In the first embodiment, the waveform processing circuit is provided in the ignition circuit configuration, but this is not necessary in the configuration using the multi-arc ignition.

Further, as in the second embodiment,
The secondary high voltage waveform is a waveform having a rising peak portion and a flat waveform portion, or as in the second embodiment, the rising time is slightly shifted by using A and B transformers. In addition, the structure of itself can sufficiently improve the ignition and combustion, and the structure of multi-arc ignition does not necessarily have to be used at the same time.

[0072]

As described above, according to the present invention, the engine is provided with the power supply device for converting the DC power into the three-phase AC, the ignition plug having three electrodes or six electrodes, and the ignition coils for three phases. Since the multi-arc ignition is used for the ignition of the engine, the arc power for ignition can be increased about 12 times or more as compared with the case of the single phase, and the ignition and the combustion can be performed more reliably, and the combustion efficiency can be improved. The fuel efficiency can be dramatically improved and the fuel efficiency can be greatly improved, and the harmful components of the exhaust gas can be greatly reduced.

Further, according to the present invention, the secondary high voltage waveform of the ignition coil is formed by superimposing a pulse wave portion having a steep rising edge and a flat portion having a low voltage and a long duration, so that the ignition is continued. The combustion can be maintained for a sufficient time, and the combustion efficiency can be greatly improved.

[Brief description of drawings]

FIG. 1 (a) is a diagram showing a circuit configuration for one phase of an ignition device for an engine of a gasoline automobile according to one embodiment of the present invention,
(b) is a diagram showing the iron core of the ignition coil, (c)
Is a view showing the cross-sectional structure of the spark plug, (d) is a plan view thereof,
(e) and (f) are waveform diagrams for explaining the operation of the above-described embodiment and the conventional ignition device.

FIG. 2 (a) is a circuit configuration diagram showing an ignition device of another embodiment of the present invention including another example of the waveform processing circuit, (b), (c),
(d) is a block diagram of the circuit of another Example.

FIG. 3 (a) is a diagram showing a configuration of a multi-arc system between an electrode of an ignition plug of an engine ignition device according to an embodiment of the present invention and its power source, and FIG. 3 (b) corresponds to that of another embodiment. FIG. 6 (c) is a view showing a configuration of the above-mentioned structure, and FIG.

4A is a diagram showing a configuration of a power supply device for forming a three-phase alternating current used in the ignition device of the above embodiment, FIG. 4B is a diagram showing an output waveform thereof, and FIG. 4C is an output of one phase thereof. It is a figure which shows a waveform.

5A is a diagram showing a configuration for outputting a secondary side waveform of an ignition coil of an engine ignition device according to another embodiment of the present invention, and FIG. 5B is a circuit configuration of a modified example of this configuration. , (C) is an ignition pulse waveform diagram for one phase,
(d) is an ignition pulse waveform diagram for three phases, and (e) is an ignition pulse waveform diagram for a 6-phase 6-electrode configuration.

6A is a sectional view of a spark plug having a 6-electrode structure according to another embodiment of the present invention, and FIG. 6B is a plan view thereof.

7A is a sectional view of a spark plug having a seven-electrode structure according to the present invention, and FIG. 7B is a plan view thereof.

FIG. 8 is a diagram for explaining a conventional engine ignition device.

FIG. 9A is a diagram for explaining another conventional ignition device for an engine, and FIG. 9B is a diagram for explaining a problem of a spark plug in the conventional ignition device.

[Explanation of symbols]

10 Ignition coil 12 Primary coil 13 Secondary coil 20 Spark plug 21 Central electrode 60 Waveform processing circuit 61 First series connection body 62 Second series connection body 63 Second capacitor 11 Ignition coil iron core 21a, 21b, 21c Metal core material (electrode) 401 DC power source 402 Conversion unit 424a to 424c for converting DC power into AC power Positive contact 425a to 425c Negative contact 421a to 421c Switch circuit 422a to 422c Reactance circuit 406a to 406c Conversion Output terminal 403 Control circuit 300 Three-phase AC power supply 301, 302, 303 Three electrodes 500A, 500B Transformer 512A, 512B Primary coil of ignition coil 513A, 513B Secondary coil of ignition coil 520 Ignition pump Spark gap of lug 601 to 606 6 electrodes 607 Neutral electrode 307

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[Procedure amendment]

[Submission date] September 9, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 6]

[Figure 7]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 9]

[Figure 4]

[Figure 5]

[Figure 8]

Claims (6)

[Claims] 1. A positive side and a negative side contact connected to the positive and negative voltages of a DC power source, and turning on / off the positive side and the negative side contact.
Alternatively, it includes a switch circuit capable of switching between the positive side contact and the negative side contact, and a reactance circuit having a reactance component and connected to the switch circuit. A neutral terminal connected to an intermediate potential between positive and negative voltages and a control circuit for controlling ON / OFF or switching operation of the switch circuit are provided, and a single-phase AC is provided between the output terminal of the conversion unit and the neutral terminal. And a DC-to-3 phase conversion power supply device for outputting 3 electrodes or 6 electrodes with their tips close to each other.
The spark plugs arranged at intervals of 60 ° or 60 ° and the outputs of the respective phases of the power supply device are applied to the primary side to generate a high voltage on the secondary side, which is applied to each of the three electrodes or the six electrodes. An ignition circuit for applying to each of the electrode pairs facing each other, and an ignition circuit for three phases including a control circuit for driving and controlling the ignition coil in synchronization with engine rotation. An ignition system for an engine that applies a three-phase voltage to a spark plug to perform multi-arc ignition. 2. A high voltage waveform on the secondary side of the ignition coil is a superimposed voltage waveform of a rectangular low voltage and a steep rising pulse wave voltage having a very high peak voltage. The engine ignition device according to claim 1. 3. The secondary side high voltage waveform of the ignition coil is a low voltage rectangular output waveform having a slight rising edge and a very sharp rising peak voltage slightly advanced from the low voltage rectangular wave voltage. The engine ignition device according to claim 1, wherein a superposed wave with a high pulse wave voltage is used. 4. The secondary-side high-voltage waveform has its rising peak suppressed, and the suppressed energy is transferred to a waveform flat portion that smoothly attenuates following the rising peak, and this waveform flat portion is lengthened. The ignition device for an engine according to claim 1, further comprising a waveform processing circuit that generates the generated waveform. 5. A spark plug for generating an arc in a cylinder, an ignition coil for generating a high voltage on a secondary side and applying the high voltage to the spark plug, and drive control of the ignition coil in synchronization with engine rotation. In the engine ignition device equipped with the control circuit for controlling the high voltage waveform on the secondary side of the ignition coil, a superimposed voltage waveform of a rectangular low voltage and a steep pulse wave voltage with a very high peak voltage is generated. An engine ignition device characterized by the above. 6. A spark plug for generating an arc in a cylinder, an ignition coil for generating a high voltage on a secondary side and applying the high voltage to the spark plug, and drive control of the ignition coil in synchronization with engine rotation. In the ignition system of an engine equipped with a control circuit for controlling a low-voltage rectangular output waveform with a slight rising edge and a pulse wave voltage with a sharp rising edge that is slightly advanced from the low-voltage rectangular wave voltage described above, An engine ignition device that has a superimposed voltage waveform of