JP3082142B2 - Engine ignition device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device for an engine, and more particularly, to a device for improving combustion efficiency by increasing the energy and duration of arc of a spark plug.

[Conventional technology]

In recent years, in automobiles, optimal control of ignition timing and fuel injection amount, as well as optimal ratios of air-fuel ratio and compression ratio, etc., have been performed from the viewpoint of improving flammability in the engine. Improvements have been made to ignition devices such as plugs and ignition coils.

7 shows a conventional general gasoline vehicle ignition device, FIG. 7 (a) is a circuit configuration diagram of the ignition device, and FIG. 7 (b) shows a closed magnetic circuit type iron core of an ignition coil. FIG. 7 (c) is a view showing an open magnetic circuit type iron core of the ignition coil, and FIG. 7 (d) is a view showing a sectional structure of the ignition plug. In the figure, reference numeral 10 denotes an ignition coil, which is configured by winding a primary coil 12 and a secondary coil 13 around a closed magnetic circuit type iron core 71, respectively. One end of the primary coil 12 is grounded via a drive transistor 14, and the base of the transistor 14 is connected to a control circuit 15. The control circuit 15 is configured to perform ignition control of the ignition coil 10 in synchronization with engine rotation. One end of the secondary coil 13 is connected to the center electrode 73 of the ignition 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 an 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 a starter connected between the ignition switch 30 and the ground, which rotates the engine at the time of starting,
A short circuit 31 is connected in parallel with the current limiting resistor 16 and short-circuits both ends of the resistor 16 by a signal from the control circuit 15 at the time of starting. This short circuit can increase the breaking current of the ignition coil. Reference numeral 17 denotes a stray capacitance existing on the secondary side of the ignition coil 10, which triggers an arc discharge in the ignition plug.

In addition to the closed magnetic circuit type iron core shown in FIG. 7 (b), the iron core also includes an open magnetic circuit type iron core 76 as shown in FIG. 7 (c). Core part 76a for winding
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.

 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. Further, when the starter 50 is driven by the ignition switch 30 to rotate the engine, the ignition coil 10 is controlled by the control circuit.
On / off control is performed by means of 15 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, and the high voltage is supplied to the ignition 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 has a peak level due to the action of the stray capacitance 17 during the initial minute period Y as shown by a dashed line S1 in FIGS. 2 (a) and 2 (b). until V ₁ rises sharply, it will immediately rapidly drops to a predetermined level V _2, slowly attenuated by subsequent decay time X (waveform flat portion). Note that a _p is the rise time.

FIG. 7 (e) shows a rotation configuration of another conventional engine fuel ignition device. In this configuration, ignition plugs 77 and 78 of two cylinders are connected in series with the ignition coil 10.
And a diode 79, and one ignition coil operates two spark plugs. Here, the above two cylinders are used in a four-cylinder engine.
Cylinder 1 or 3 or 180
2, the fourth cylinder.

Other configurations are the same as those shown in FIG. 7 (a).

In such a circuit configuration, the ignition plug sparks simultaneously in the cylinder in the exhaust process and the cylinder in the compression process.However, the cylinder in the exhaust process discharges without difficulty because the air pressure is small, and the resistance of the circuit is reduced. It can be ignored and does not explode because it is an exhaust process. On the other hand, the ignition plug of the cylinder in the compression process generates an arc from the spark plug on the exhaust side and forms a discharge circuit, so the arc is instantaneously delayed, but in the compression ignition process, an explosion occurs. Drives automatically.

[Problems to be solved by the invention]

However, in the above-described ignition device, the arc discharge due to the stray capacity is extremely short in the order of 10 ^-9 seconds, and the effective portion for actually igniting gasoline is the above-mentioned waveform flat portion X having small energy, In other words, the voltage of this part is 300-500V and the period is around 2/1000 seconds,
Gasoline ignition was not enough. For this reason, gasoline combustion efficiency is currently low at the 30% level, and less than 70% is exhausted due to incomplete combustion and pollutes air, and because of poor combustion efficiency, power is not enough for gasoline consumption. There was a problem.

Also, the iron core 71 of the ignition coil has an open magnetic circuit type in which the width Wc of the central leg 71a and the width Ws of the side legs 71b, 71c on both sides are substantially the same or extremely large, There is a large loss in the cross-sectional area and the magnetic path.Therefore, there is a problem that the magnetic flux is overcrowded in the center leg 71a, a loss occurs due to heat generation, and in this case, the number of turns of the coil must be increased. There was an irrationality to make it longer. Further, a gap is formed in a part of the center leg 71a to form a magnetic flux leakage type arc generator.

Further, in the spark plug 72, the tip 75 of the ground electrode 75 is provided.
Since a is located so as to cover the tip portion 73a of the center electrode 73, the ground electrode tip portion 75a blocks the spread of the spark F as shown in FIG. There was a problem that the ignition of the fuel in the part was delayed or insufficient. Here, E is the peripheral wall of the engine.

Further, in a configuration in which two ignition plugs are ignited by one ignition coil, the spark of the ignition plug in the exhaust process does not interfere with the ignition explosion in the compression process.
Since the useless arc is generated in the cylinder in the exhaust process, there is a disadvantage that the life of the spark plug is shortened.

The present invention has been made in view of the above problems, and can significantly improve the combustion efficiency from the conventional 30%, thereby increasing the engine output,
It is an object of the present invention to provide an engine ignition device that can improve fuel efficiency and reduce exhaust gas.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ignition device for an engine that can reduce a loss due to heat generation and leakage of a magnetic flux generated in an ignition coil.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ignition device for an engine having a spark plug capable of spreading a sparked arc uniformly in a cylinder and rapidly and sufficiently igniting fuel.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ignition device for an engine in which two ignition plugs can be operated by one ignition coil without shortening the life of the ignition plug.

[Means for solving the problem]

In the ignition device for an engine according to the present invention, a waveform processing circuit is connected between the secondary side of the ignition coil and the spark plug, and the waveform processing circuit converts the secondary-side high-voltage waveform of the ignition coil into a rising waveform. The peak is suppressed, and the energy corresponding to the suppressed peak is transferred to a smoothly attenuated waveform flat portion following the rising peak, so that the waveform flat portion has a longer waveform.

According to the present invention, in the ignition device for an engine, a completely closed magnetic path type iron core having no center gap and side legs on both sides thereof is used as an iron core of an ignition coil, and a cross-sectional area of the center leg of the iron core is used. It is set to be approximately twice the cross-sectional area of the side legs on both sides.

According to the present invention, in the ignition device for an engine, the ignition plug is provided such that a tip end of an electrode to which a secondary high voltage of an ignition coil is applied and a tip end of a ground electrode connected to the vehicle body are provided at a mounting position of the ignition plug. This is configured to be included in a plane perpendicular to the normal line of the cylinder inner wall surface.

According to the present invention, in the ignition device of the engine, the control circuit for the ignition coil is configured to generate a high voltage on the secondary side of the ignition coil by inverting its polarity at a predetermined timing. Two spark plugs are connected in parallel on the next side, and each spark plug is sparked by a high voltage of a predetermined polarity by a forward / reverse switching circuit.

[Action]

In the present invention, a waveform processing circuit is provided between the secondary side of the ignition coil and the ignition plug to suppress the rising peak of the secondary-side high voltage waveform, and convert the suppressed energy into the rising peak. Since the waveform is shifted to the following smoothly flattened waveform flat portion to make the waveform flat portion longer, the time required for the arc of the spark plug to contribute to the ignition of fuel increases, and the energy of the arc increases. It will be. As a result, the combustion in the engine is sufficiently and reliably performed, and the combustion efficiency in the engine is remarkably improved, thereby increasing the output of the engine and solving the problems of fuel consumption and measures for exhaust gas.

Also, in the present invention, the ignition coil includes:
A completely closed magnetic circuit type iron core with the cross-sectional area of the center leg set to almost twice the cross-sectional area of both side legs is used, so the magnetic flux does not become overcrowded at the center leg, and a high voltage is generated efficiently. Also, heat generation at the iron core can be prevented. Further, since the above-mentioned completely closed magnetic circuit type iron core has a structure without a gap, the number of turns can be greatly reduced in both primary and secondary, and there is no unnecessary leakage of magnetic flux. 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. In addition, since the number of windings is small, the impedance can be reduced, and the rise time is short, which is advantageous for speeding up. In addition, the energy of useless discharge for a short time of 10 ^-6 to 10 ^-9 seconds due to the stray capacity can be suppressed.

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

In the present invention, the high voltage is generated at the secondary side of the ignition coil by inverting the polarity of the high voltage at a predetermined timing, and the two spark plugs are sparked by the high voltage of the predetermined polarity. Spark plugs no longer spark at the same time, that is, sparks in the cylinders in the exhaust process due to sparks in the cylinders in the explosion process no longer spark, and sparks are fired only in the cylinders in the explosion process, thereby reducing the consumption of the spark plug. be able to.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First
FIG. 1 shows an overall configuration of an ignition device for a gasoline vehicle according to an embodiment of the present invention. FIG. 1 (a) is a circuit configuration diagram of the ignition device, and FIG. 1 (b) is an iron core of an ignition coil of the ignition device. FIG. 1 (c) is a view showing a sectional structure of a spark plug of the ignition device. In the figure, the sixth
The same reference numerals as those in the figure indicate the same or corresponding parts, and 60 suppresses the rising peak of the secondary high voltage of the ignition coil 10 and adds the suppressed energy to the waveform flat part where the waveform attenuates smoothly, A waveform processing circuit for extending the flat portion of the waveform is provided by the ignition coil.
It is connected between the secondary coil 13 of 10 and the center electrode 21 of the spark plug 20. Reference numeral 61 denotes a first series connection body constituting the circuit, which is formed by connecting a first resistor 61a and a first coil 61b in series. Reference numeral 62 denotes a second series connection body, which is formed by connecting a first capacitor 62a, a second resistor 62b, and a second coil 62c in series, and connected in parallel with the first series connection body 61. I have. Reference numeral 63 denotes a second capacitor connected in parallel with the first series-connected body 61 and having a considerably smaller capacity than the first capacitor 62a.

FIG. 1 (b) shows an iron core of the ignition coil 10, wherein the iron core 11 is of a closed magnetic circuit type, and the width Wco of the central leg 11a is the width Ws of the left and right side legs 11b and 11c. The center leg 11a has side legs 11b and 11c.
Has about twice the cross-sectional area of

FIG. 1 (c) shows a cross-sectional structure of the spark plug. Reference numeral 21 denotes a metal core material serving as a center electrode, which is covered with an insulating member 22 such as ceramic. Reference numeral 23 denotes a metal outer skin mounted on the insulating member 22, and one end of the outer skin is a pair of ground electrodes 23a arranged so as to sandwich the center electrode tip 21a from both sides. Here, the tip of the ground electrode 23a and the tip 21a of the center electrode 21 are configured to be located in a plane perpendicular to the axial direction of the center electrode 21.

 Next, the operation will be described.

The operation from the time when the ignition switch 30 is turned on until the engine is brought into the automatic operation state is the same as the conventional operation, and therefore the description is omitted. Here, the waveform processing circuit 60 for processing the high voltage waveform on the secondary side of the ignition coil 10 is used. The operation will be described.

First, when a high voltage is supplied from the ignition coil 10 to the waveform processing circuit 60, the second capacitor 63 is charged to a high voltage in a relatively short time, and supplies the voltage to the spark plug 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 second coil 61b supplies the secondary voltage to the ignition plug 20 while suppressing the sudden rising peak of the high voltage generated in the secondary coil 13 of the ignition coil.

By the operation of the waveform processing circuit 60, the shape at the rising portion of the secondary voltage is, as shown by the solid line S0 in FIGS. 2A and 2B, the peak level of the conventional V ₁ (20,000 or more thousands). Volts) to V ₀ (10,000 volts), the number of turns is small, and the efficiency is a complete magnetic path type.
Large energy rises more steeply,
Since the waveform has a drooping characteristic, the formation energy of the gasoline ignition nucleus becomes larger. Where a _I is the rise time is shorter than the conventional a _P.

To the extent that the waveform attenuates after the waveform rises, first, the large-capacity first capacitor 62a
Is discharged, and then the current supply at a certain level is extended by the action of the first and second coils 61b and 62c. For this reason, the waveform flat portion X _{0 where} the waveform attenuates smoothly, that is, the portion contributing to combustion, as shown in FIG. 2 (a), has larger energy and longer duration than the conventional X. As a result, an arc having such a waveform is generated in the cylinder.

As described above, in this embodiment, the waveform processing circuit 60 is provided between the secondary side of the ignition coil 10 and the spark plug 20,
The secondary high voltage waveform of the ignition coil 10 is suppressed in its peak, the energy is added to the smoothly attenuated waveform flat portion following the rising peak, and the duration of the waveform and the waveform flat portion. Because of the increased energy, the duration of the arc in the cylinder is increased, and the spark is stronger. Further, since the first and second series-connected bodies 61 and 62 of the waveform processing circuit 60 include coils, the arc can have a drooping characteristic, and the ignition time and the firing nucleus forming energy can be further increased. Thus, ignition at high engine speed can be ensured. As a result, regardless of the low-speed or high-speed rotation of the engine, the ignition of the fuel is reliably and sufficiently performed, thereby increasing the combustion efficiency and reducing the incompletely combusted gas.

In this embodiment, the iron core of the ignition coil 10 is
Since the center leg 11a has a cross-sectional area approximately twice that of the side legs 11b and 11c and has no gap, the ignition coil can be an efficient transformer. That is, the magnetic resistance of the transformer is significantly reduced, and the number of generated magnetic force lines increases. The saturation current is further increased, and the number of turns of the primary coil is reduced to 100 times, which is less than one-third of the conventional one,
The number of turns of the secondary coil can be reduced by almost 30% compared to the conventional coil, and the weight and size can be reduced, and an efficient large-capacity arc can be generated. Also, by reducing the number of turns in this way, the time constant L / R becomes smaller and becomes steeper from the rise, and the temporal current change becomes larger, so that the certainty of fuel ignition in a high-speed state can be increased.

Further, since the spark plug 20 is configured such that the tip 21a of the center electrode 21 and the tip 23a of the ground electrode 23 are included in a plane perpendicular to the axial direction of the center electrode 21, the ground electrode is used when the arc is generated.
The 23 does not block the spread of the arc and no spark shadows are created in the cylinder. This also improves the reliability of ignition.

In the above embodiment, 12 volts of the battery voltage is directly supplied to the primary side of the ignition coil. However, as shown in FIG. 3 (a), the ignition switch 30 and the battery 40 are connected to each other. A diode-rotor booster circuit 70 is provided between
The voltage may be raised to about volt and such a high voltage may be supplied to the primary coil. In this case, the load on the ignition coil is reduced, 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 configuration shown in FIG. 1 (a). In principle, as shown in FIG. 1 (d), a capacitance component 60a for delaying the secondary high voltage waveform is provided. Inductive component that suppresses the rising peak and has a drooping characteristic
Any circuit configuration may be used as long as 60b and the resistance components 60c and 60d for attenuating the current are connected in parallel or in series.

However, a circuit 65 having no inductive component as shown in FIG. 3B may be used in some cases. In this circuit, the second series-connected body 62 comprises a first capacitor 62a having a large capacity and a second resistor 62b, and the series-connected body 62 has a first capacitor 61 and a second capacitor having a small capacity, respectively. 63 is connected in parallel.

In this case, it is not expected that the arc has a drooping characteristic, but the rising peak of the high voltage generated on the secondary side of the ignition coil is suppressed to increase the energy in the flat portion of the waveform and extend the flat portion of the waveform. The effect that can be obtained is obtained.

In the first embodiment, an LC circuit formed by connecting a capacitor and a coil in parallel may be connected in parallel with the ignition plug. In this case, the duration of the arc may be reduced by using magnetostrictive resonance or a resonance phenomenon. It can be further increased.

FIG. 4 is a diagram for explaining an engine ignition device according to a second embodiment of the present invention. Here, in the circuit configuration of the first embodiment, an additional portion is provided between the waveform processing circuit 60 and the spark plug 20. The additional resistor 6 is connected in series, and the additional resistor 6 is incorporated in a part of the center electrode 21 of the ignition plug 20. Other configurations are the same as those of the first embodiment.

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

5 (a) to 5 (c) are diagrams for explaining an engine ignition device according to a third embodiment of the present invention. In the drawings, reference numerals 81 and 82 denote secondary coils 13 of the ignition coil 10, respectively. 83 is a third waveform processing circuit connected to the middle point of the secondary coil 13 of the ignition coil 10, and the configuration of each of the above-mentioned waveform processing circuits is the same as that of the first and second waveform processing circuits. 1 This is the same as the principle circuit configuration shown in FIG. Reference numeral 25 denotes a spark plug having a high-voltage side electrode 25a, a center electrode 25c, and a low-voltage side electrode 25b.Each of the above-mentioned electrodes is arranged in a straight line in this order.
Outputs of the third and second waveform processing circuits are sequentially connected.
Reference numeral 84 denotes an additional resistor inserted in series between the third waveform processing circuit 83 and the third electrode 25c. Here, the shape of the central electrode 25c on the low voltage side with respect to the high voltage side electrode 25a and the shape of the low voltage side electrode 25b on the lower voltage side with respect to the central electrode 25c are respectively higher voltage electrodes. And has a sharp protruding portion at a portion opposed to.

In the third embodiment having such a configuration, there are three electrodes, and there are three arcs, and even if it is difficult to generate one arc, the air is ionized and easily ignited, and electrons from the electrodes are ejected. Since the portion has a sharp shape, an arc is easily generated, and the generated arc is stable. A, B2
Arcs are generated at several places, whereby the reliability of ignition of the fuel can be further increased as compared with the first embodiment, and the combustion efficiency can be further improved. Also, since the waveform processing circuit is connected between the secondary coil and each electrode, arc discharge between the high-voltage side electrode 25a and the center electrode 25c, and the center electrode 25c and the low-voltage side electrode 2c
For each of the arc discharges between 5b and 5b, the drooping characteristics can be made to wait, and the rise can be made steep.

FIG. 5 (d) shows an engine ignition device according to a fourth embodiment of the present invention, which differs from the above embodiment only in the arrangement of the three electrodes of the ignition plug. That is, here, the center electrode 26c and the high-voltage and low-voltage side electrodes 26a and 26b of the ignition plug 26 are arranged at the vertices of a predetermined triangle so that an arc can be generated between the electrodes.

In this embodiment, the central electrode 26c and the two side electrodes 26a, 2
Since an arc is generated between the cylinder 6b and the two side electrodes 26a, 26b, the arc generated in the cylinder can be strong. Even if an arc does not occur between the two side electrodes 26a and 26b, a high voltage is applied between these electrodes, although momentarily, whereby the fuel is ionized and a firing nucleus is easily formed. An environment is created, which is advantageous for fuel ignition. Further, since a double voltage between the center electrode and the side electrodes is applied between the side electrodes 26a and 26b, the arc distance increases, and the ignition energy increases accordingly.

This shows that the three-electrode system has better ignition efficiency than the two-electrode system, but the arrangement on the vertices of the triangle is better than the linear arrangement.

In this embodiment, of course, as shown in FIG. 5 (d), the electrode of the spark plug has a sharply sharpened portion on the low potential side electrode facing the high potential side. Easy to occur.

FIG. 6 (a) shows an engine ignition device according to a fifth embodiment of the present invention, in which FIG. 5 (a) to FIG.
In the circuit configuration of the third embodiment shown in (c), a circuit configuration in which a capacitor and a coil are connected in parallel is used as the second waveform processing circuit 82, and the second waveform processing circuit 82 is used instead of the third waveform processing circuit 83. Are provided with first and second LC circuits 91 and 92 each having a capacitor C and a coil L connected in parallel. One end of each of the LC circuits is connected to the middle point of the secondary coil of the ignition coil 10, and The other ends of the first and second LC circuits 91 and 92 are connected to the outputs of the first and second waveform processing circuits 81 and 90, respectively, and the center electrode 25c is grounded.

In this embodiment, the first and second waveform processing circuits 81 and 82
The energy of arc generation is increased by the action of
Furthermore, the arc duration, that is, 300 to 5 at the waveform flat part
The voltage of 00V can be maintained for a long time, and the efficiency of gasoline ignition can be further improved.

FIG. 6 (b) shows an engine ignition device according to a sixth embodiment of the present invention. Here, in the fifth embodiment described above, instead of the circuit configuration on the primary side of the ignition coil 10, a high level is used. A voltage control circuit 100 capable of inverting the polarity of the voltage at a predetermined timing and outputting the inverted voltage to the secondary side of the ignition coil is used, and the first and second spark plugs 27,
28 are connected in parallel. That is, the first spark plug
In 27, the center electrode 27c and the side electrodes 27a, 27b are arranged at the vertices of a predetermined triangle, and the center electrode 27c is connected to the midpoint of the secondary coil 13 and grounded. The high-voltage side electrode 27a is connected to the coil via a forward diode 101.
The low-voltage side electrode 27b is connected to one end of the switch 13 and the other end.

In the second spark plug 28, the low-voltage side electrode 28
b is the anode of the diode 101, the high-voltage side electrode 28
a is connected to the other end of the coil 13 via the forward diode 102, and the center electrode 28c is grounded.

Further, a forward / reverse switching circuit 105 is connected in parallel with the diode 101. The forward / reverse switching circuit 105 applies a voltage only to the first spark plug when one end of the secondary coil 13 has a high voltage, that is, the electrodes 27a and 28b, and has a high voltage applied to the other end, that is, the electrodes 27b and 28a. When this happens, a voltage is applied only to the second spark plug 28, for example, a diode connected in anti-parallel with the diode 101. Here, the first and second spark plugs are applied to cylinders in which an explosion process and an exhaust process are separated by 180 degrees, such as the first and third cylinders or the second and fourth cylinders of a four-cycle engine. .

In this embodiment, the ignition plugs of the two cylinders can be driven by one ignition coil, and the voltage is applied to the ignition plugs only by the forward / reverse switching circuit 105 during the explosion process of each cylinder. Thus, the life of the spark plug can be extended as compared with the case where the voltage is supplied to the spark plug in both the explosion process and the exhaust process.

FIG. 6C shows a modification of the sixth embodiment. In FIG. 6B, the second waveform processing circuit 82 connected to the other end of the coil 13 in FIG. R, coil L and capacitor C are connected in parallel, and resistors 81a and 82a are inserted in series with the outputs of the first and second waveform processing circuits 81 and 82, respectively. Further, the first LC circuit 91 is connected between the midpoint of the coil 13 and one end, and the second LC circuit 92 is connected between the midpoint of the coil 13 and the other end.

FIG. 6 (d) is an explanatory view of an engine ignition device according to the embodiment of FIG. 7 of the present invention, and shows a five-electrode system. Here, in the fifth embodiment shown in FIG. 6 (a), two secondary coils 13a and 13b are wound around the secondary side of the ignition coil 10, and each secondary coil is shown in FIG. 6 (c). As described above, the first and second waveform processing circuits 81 and 82 and the LC circuit 91,
92, and as a spark plug, a center electrode 121e and four side electrodes 121a to 121d evenly arranged around the center electrode 121e.
Is used. Then, the outputs of the first and second waveform processing circuits 81 and 82 on the first secondary coil 13a side are
The center point P1 of the coil 13a is connected to the side electrodes 121a and 121b via the resistors 81a and 82b, respectively. Similarly, the second secondary coil 13b is also connected to the first and second waveform processing circuits 81 and 82.
Are connected to the side electrodes 121c and 121d via the resistors 81a and 82a, and the center point P2 of the coil 13b is connected to the center electrode 121e.

In the structure of this embodiment, as shown in FIG. 6 (f), arcs A1 to A4 are generated between the center electrode 121e and the four side electrodes 121a to 121d. The above arc Three times stronger arcs B1 to B4 are generated. As a result, the arc becomes strong and the ignition nucleus spreads quickly and greatly. Also, even if a misfire does not occur in the gap between any of the electrodes without causing an arc, an ignition nucleus force is generated, which is useful for forming an expanding atmosphere. From this, it is understood that it is better to connect two sets of secondary coils at the center point and to use this as a central electrode and arrange four electrodes around the center so as to be mutually positive and negative, rather than arranging electrodes on the vertices of the triangle.

FIG. 6 (e) is a diagram showing an engine ignition device according to an eighth embodiment of the present invention.
This is a combination of the configuration in which two ignition plugs are operated by one ignition coil and the five-electrode system of the seventh embodiment.

That is, in the circuit configuration shown in FIG. 6D, in addition to the ignition plug 121, the center electrode 122e and the four side electrodes 1
A spark plug 122 having 22a to 122d is provided, and FIG.
As shown in the figure, the electrodes at the corresponding position of each plug
That is, the center electrodes 121e, 121e, and the side electrodes 121a-121
d, 122a to 122d are connected to each other. Also, here, forward-connected diodes 101 are inserted into the feed lines of the side electrodes 121a and 121c of the first spark plug, respectively, and the forward-direction diodes are inserted into the feed lines of the side electrodes 121d and 122d.
102 are inserted in series, and a forward / reverse switching circuit 105 is connected in parallel with each of the diodes 101.

In this embodiment, the ignition arc can be made strong, and the two-electrode ignition plug can be implemented with a five-electrode system using two ignition coils.

In the above-described fifth to eighth embodiments, the spark plug has the LC
Circuits are connected in parallel, but the circuit connected in parallel to the spark plug is an RC circuit consisting of resistors and capacitors connected in parallel, or an LRC circuit consisting of resistors, capacitors and coils connected in parallel.
It may be a circuit.

〔The invention's effect〕

As described above, according to the engine ignition device of the present invention, a waveform processing circuit is provided between the secondary side of the ignition coil and the ignition plug to suppress the rising peak of the secondary high voltage waveform, The reduced energy is transferred to a smoothly attenuated waveform flat portion following the rising peak to make the waveform flat portion a long waveform, so that the arc of the spark plug contributes to fuel ignition. As time increases, the energy of the arc will increase. As a result, the combustion in the engine is sufficiently and reliably performed, and the combustion efficiency in the engine is remarkably improved, thereby increasing the output of the engine and solving the problems of fuel consumption and measures for exhaust gas.

In addition, since the ignition coil uses a closed magnetic circuit type iron core in which the cross-sectional area of the center leg is set to approximately twice the cross-sectional area of both side legs, the magnetic flux does not become overcrowded at the center leg, Heat generation at the iron core can be prevented. Further, since the closed magnetic circuit type iron core has a structure without a gap, no leakage of magnetic flux occurs. As a result, the magnetic flux generated in the iron core works effectively, and the energy loss in the iron core can be reduced.

In addition, since the center electrode and the ground electrode of the spark plug are configured so that the tips of the two electrodes are included in a plane perpendicular to the normal of the cylinder inner wall surface at the mounting position of the spark plug, a spark arc is generated in the cylinder. Thus, the fuel can be ignited quickly and sufficiently, and the combustion efficiency can be improved.

Furthermore, the polarity of the high voltage is inverted at a predetermined timing and is generated on the secondary side of the ignition coil, and the two spark plugs are sparked by the high voltage of the predetermined polarity. There is no spark, that is, there is no spark in the cylinder in the exhaust process following the spark in the cylinder in the explosion process,
The spark is generated only in the explosion process of each cylinder, thereby suppressing the consumption of the spark plug.

By improving the ignition coil and the spark plug, the engine output can be increased, and the fuel consumption can be improved and the exhaust gas can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing the overall configuration of an engine ignition device according to one embodiment of the present invention, FIG. 2 is a waveform diagram for explaining the operation thereof, and FIG. 3 is a modification of the first embodiment. Diagram,
FIG. 4 is a diagram showing a configuration of an ignition device according to a second embodiment of the present invention, FIG. 5 is a diagram showing ignition devices according to the third and fourth embodiments of the present invention, and FIG. FIG. 7 is a view showing an engine ignition device according to the fifth to eighth embodiments, FIG. 7 is a diagram for explaining a conventional engine ignition device, and FIG. 8 is a diagram for explaining a problem of a spark plug in the conventional ignition device. FIG. In the figure, 6,84 is an additional resistor, 10 is an ignition coil, 11 is a closed magnetic circuit type iron core, 12 is a primary coil, 13 is a secondary coil, 15 is a control circuit, 16 is a current adjusting resistor, and 20, 25 to 28,121,
122 is a spark plug, 21, 25c to 28c, 121e, 122e are central electrodes,
22 is a ground electrode, 25a to 28a, 25b to 28b, 121a to 121d, 122a to
122d is a side electrode, 30 is an ignition switch, 40 is a battery, 50 is a starter, 60 is a waveform processing circuit, and 61 is a first
Series connection body, 61a is a first resistor, 61b is a first coil,
62 is a second series connection body, 62a is a first capacitor, 62b is a second resistor, 62c is a second coil, 63 is a second capacitor, 70 is a booster circuit, and 81 to 83 are first to first. 3, a waveform processing circuit, 91 and 92 are LC circuits, 100 is a voltage control circuit, 101 and 102 are diodes, and 105 is a sequential switching circuit. In the drawings, the same reference numerals indicate the same or corresponding parts.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02P 3/00 F02P 15/00 302

Claims (12)

(57) [Claims] An ignition 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 ignition plug, and driving control of the ignition coil in synchronization with engine rotation An ignition device having a control circuit for controlling the secondary high voltage waveform,
A waveform processing circuit that transfers the suppressed energy to a smoothly attenuated waveform flat portion following the rising peak to make the waveform flat portion a longer waveform; An ignition device for an engine, comprising a series waveform processing circuit connected in series to a plug. 2. An ignition 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 ignition plug, and driving control of the ignition coil in synchronization with engine rotation. An ignition device having a control circuit for controlling the secondary high voltage waveform,
A waveform processing circuit that transfers the suppressed energy to a smoothly flattened waveform flat portion following the rising peak to make the waveform flat portion longer. An ignition device for an engine, comprising: a series waveform processing circuit connected in series to a plug; and a parallel waveform processing circuit connected in parallel to the ignition plug. 3. The ignition device for an engine according to claim 1, wherein the series waveform processing circuit includes: a capacitance element for delaying the secondary high voltage waveform; and an arc generation in the waveform by suppressing a rising peak thereof. An ignition device for an engine, wherein an induction element having a reasonable drooping characteristic and a resistance element are connected in parallel. 4. The ignition device for an engine according to claim 2, wherein the parallel waveform processing circuit is an LC circuit formed by connecting a coil and a capacitor in parallel, an RC circuit formed by connecting a resistor and a capacitor in parallel, or An engine ignition device characterized by an LRC circuit comprising a coil, a resistor, and a capacitor connected in parallel. 5. The engine ignition device according to claim 1, wherein the series waveform processing circuit includes: a series connection body formed by connecting a first capacitor and a first resistor in series; and each of the series connection bodies. An ignition device for an engine, comprising: a second resistor and a second capacitor connected in parallel to the ignition device. 6. The engine ignition device according to claim 1, wherein the series waveform processing circuit includes: a first series connection body formed by connecting a resistor and a coil in series;
A capacitor, a resistor, and a coil are connected in series, comprising a second series-connected body connected in parallel with the first series-connected body, and a capacitor connected in parallel with the first series-connected body. An ignition device for an engine, comprising: 7. The engine ignition device according to claim 1, wherein an additional resistor is inserted between the waveform processing circuit and a center electrode of the ignition plug. 8. An engine ignition device according to claim 7, wherein said additional resistor incorporates a resistor having a drooping characteristic and a resistor for preventing noise. 9. An ignition plug for generating an arc in a cylinder, an ignition coil for generating a high voltage on the secondary side and applying the same to the ignition plug, and ignition control in synchronization with the engine rotation of the ignition coil. And a control circuit, wherein the ignition plug has three electrodes arranged at equal intervals on a straight line or at the vertices of a triangle. First on both ends,
A second waveform processing circuit is connected to a third waveform processing circuit at a middle point of the secondary coil, and an output of the third waveform processing circuit is connected to a center electrode of the ignition plug, and the first and the second are processed. The output of the second waveform processing circuit is connected to the electrodes on both sides of the spark plug. Each of the waveform processing circuits suppresses the rising peak of the secondary high-voltage waveform and dissipates the energy corresponding to the suppressed peak. An ignition device for an engine, characterized in that the circuit configuration is such that the waveform is shifted to a smoothly attenuated waveform flat portion following the rising peak and the waveform flat portion is elongated. 10. An engine ignition device according to claim 9, wherein first and second LC circuits each having a capacitor and a coil connected in parallel are provided in place of said third waveform processing circuit. One end of the circuit is connected to the middle point of the secondary coil of the ignition coil, and the other ends of the first and second LC circuits are connected to the outputs of the first and second waveform processing circuits, respectively. An ignition device for an engine, comprising: 11. The ignition device for an engine according to claim 10, wherein two secondary coils are wound around a secondary side of the ignition coil, and a middle point of each of the secondary coils is made common. A structure having an electrode and four side electrodes arranged at equal intervals around the electrode, the midpoint of the secondary coil is connected to the center electrode, and both ends of each secondary coil are adjacent to the four electrodes. An ignition device for an engine, wherein matching electrodes are connected so as to have different polarities. 12. The ignition device for an engine according to claim 9, wherein said control circuit inverts a polarity of a high voltage at a predetermined timing to a secondary side of said ignition coil. And two ignition plugs are connected in parallel to the secondary side of the ignition coil, and each ignition plug is sparked by a high voltage of a predetermined polarity by a forward / reverse switching circuit. Engine ignition device.