JPH0326303Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is capable of applying high voltage generated from an ignition coil directly to the spark plug of each cylinder via a high tension cord without using a power distribution mechanism. This invention relates to a direct distribution type ignition system.

[Conventional technology]

Generally, the ignition system of a multi-cylinder internal combustion engine is
As shown in the figure, the transistor 2 is turned on by the AC voltage signal obtained from the ignition signal generator 1.
By turning off, the current flowing through the primary winding 4 of the ignition coil 3 is turned on and off. The current flowing through the primary winding 4 is
When turned off, a high voltage is generated in the secondary winding 5, and this high voltage is connected to the side electrodes 7, 8, 9, and 10 through the rotor electrode 6, which rotates in the direction of arrow R. No.1 cylinder, No.3 cylinder, No.4
Power is distributed to the spark plug 11 of the No. 2 cylinder (in the case of a 4-cylinder internal combustion engine). Note that the B terminal of the primary winding 4 is connected to a battery power source.

In this way, the rotor electrode 6 and the side electrodes 7 to 1
Since a power distribution mechanism consisting of 0 is used, the spark discharge generated between the rotor electrode 6 and the side electrodes 7 to 10 may generate radio noise and cause radio wave interference, or the arrangement of the side electrodes 7 to 10 may be affected. Since a certain interval must be maintained to prevent spark discharge between adjacent electrodes, there are problems such as the inability to downsize the power distribution mechanism.

For this reason, recently, high voltage generated from the secondary winding 5 of the ignition coil 3 is transferred to a high tension cord without using the power distribution mechanism composed of the rotor electrode 6 and the side electrodes 7 to 10. As a result, devices such as those shown in FIGS. 5 and 6 have come into practical use, which apply power directly to the spark plugs of each cylinder.

FIG. 5 shows a direct distribution type ignition system using two ignition coils, which uses four ignition coils.
This shows an example of application to a cylinder internal combustion engine.
The firing order is No. 1 cylinder 100, No. 3 cylinder 10
1, No. 4 cylinder 102, and No. 2 cylinder 103.

The crank angle signal generator 32 is connected to a G timing rotor fixed to the distributor shaft.
Using the Ne timing rotor, the G timing rotor detects the reference position of the crank angle, and the Ne timing rotor extracts the crank angle as an electric signal every 15 degrees to 30 degrees, for example.

The No. 1 and No. 4 cylinder ignition signal generation circuit 33 is
Generates an electric signal when the optimum ignition timing is reached within the crank angle range of 310° to 360° (for No. 1 cylinder 100) and 670° to 720° (for No. 4 cylinder 102). It is a circuit. The No. 3 and No. 2 cylinder ignition signal generation circuits 34 have crank angles of 490° to 540° (No.
3 cylinder 101), 130° to 180° (No. 2 cylinder 10
This circuit generates an electric signal when the optimum ignition timing is reached within the range of case 3).

Transistors 35 and 36 are No. 1 and No.
4-cylinder ignition signal generation circuit 33 and No. 3 and
This is to turn on and off the current flowing through the primary windings 30a and 31a of the ignition coils 30 and 31 using the electric signal output from the No. 2 cylinder ignition signal generation circuit 34. 30
A high voltage is generated in the secondary windings 30b and 31b every time the current flowing through a and 31a is turned off. In addition, B of the primary windings 30a and 31a
The terminals are connected to battery power.

The high voltage generated in the secondary windings 30b and 31b is applied to high tension cords 150, 152 and 151, 15 connected to the winding start terminal S and the winding end terminal E of the secondary windings 30b and 31b.
3, spark plug 20 of No. 1 cylinder 100
0, No. 4 cylinder 102 spark plug 202 and
Spark plug 201 for No. 3 cylinder 101, No. 2 cylinder 1
The power is applied directly to each spark plug 203 of No. 03.

On the other hand, by transistors 35 and 36,
When turning on and off the primary windings 30a and 31a of the ignition coils 30 and 31,
A voltage waveform as shown in FIG. 4 is generated in the secondary windings 30b and 31b. That is, Figure 4a
The waveform shown in is the waveform of transistors 35 and 36.
Primary windings 30a and 31 depending on ON and OFF
The waveform shown in FIG. _4b shows the voltage waveform _V2 generated in the secondary windings 30b and 31b by the current _I1 . be. Note that time t is plotted on the horizontal axis.

As can be seen from FIG. 4, transistors 35 and 36 are turned on and primary windings 30a and 31
When the current _I1 starts to flow through a, a high voltage (hereinafter referred to as ON voltage) as shown by arrow P in FIG. 4b is generated. At the moment when the current _I1 is cut off, a high voltage (hereinafter referred to as ignition voltage) is generated for generating ignition sparks at the ignition plugs 200 to 203 as shown by arrow Q in FIG. 4b.

Such an ON voltage may be, for example, about 1Kv to 2Kv, and directly connects the spark plug to 200 to 20
3, so depending on the engine operating condition, this ON voltage will cause a spark discharge, and before the ignition voltage (for example, 10 Kv to 30 Kv) is generated (before the crank angle is 20° to 100°). There is a risk of ignition combustion and engine malfunction.

Therefore, the ON voltage indicated by the arrow P in FIG. 4b is not applied to the spark plugs 200 to 203 at both ends of the secondary windings 30b and 31b.
Diodes 37 and 38 are connected forward in the direction of the ignition voltage.

In addition, in the power distribution mechanism using the rotor electrode 6 and side electrodes 7 to 10 shown in FIG. 7, the ON voltage shown by arrow P in FIG. 4b is always θ hours before the ignition voltage shown by arrow Q. Therefore, the position of the rotor electrode 6 is also earlier by θ time, as shown by the dotted line in FIG. Therefore, even if the gap between the rotor electrode 6 and each of the side electrodes 7 to 10 is narrow when facing each other, since they are at the earlier position by θ time, there is a sufficient gap, so spark discharge due to the ON voltage will not occur. There is no need to take measures against ON voltage.

FIG. 6 shows an example in which a diode distribution direct distribution type ignition system using one ignition coil is applied to a four-cylinder internal combustion engine. In FIG. 6, parts corresponding to those in FIG. 5 are designated by the same reference numerals as in FIG. 5.

A B terminal for connecting to a battery power source is provided at the center of the primary winding 40a of the ignition coil 40, and the beginning of the primary winding 40a is connected to the collector of the transistor 35 via a diode 41. , the ends of the windings are connected to the collector of the transistor 36 via the diode 42, respectively. When the transistor 35 is turned on, a current flows in the direction of the arrow X in the primary winding 40a, and when the transistor 36 is turned on, a current flows in the direction of the arrow Y.

Therefore, the high voltage generated across the secondary winding 40b is generated when the transistor 35 is activated and when the transistor 35 is activated.
6 is activated, the polarity is reversed. Therefore, when applying the ignition voltage to the No. 1 cylinder 100 and the No. 4 cylinder 102, the winding start terminal S side is set to a positive potential and the winding end terminal E side is set to a negative potential. Cylinder 100 and No. 4 cylinder 102
An ignition voltage is applied to the spark plugs 200 and 202 via diodes 43 and 46. Furthermore, when applying the ignition voltage to the No. 3 cylinder 101 and the No. 2 cylinder 103, the winding start terminal S side is set to a negative potential and the winding end terminal E side is set to a positive potential.
The ignition voltage is applied to 1 and 203 via diodes 45 and 44.

In this case, the potentials of the winding start terminal S and the winding end terminal E of the secondary winding 40b alternately change to a positive potential and a negative potential, so that the potentials as shown in FIG.
Diodes 37 and 38 to suppress ON voltage
cannot be used.

[Problem that the invention attempts to solve]

However, when using such a direct distribution type ignition system, the diodes 37 and 38 for suppressing ON voltage are required to have high withstand voltage and heat resistance in the coil distribution system shown in FIG. In the diode distribution method shown in Figure 6, which significantly increases costs and increases the size of the diodes, no diode is used to suppress the ON voltage, so there is no practical method for suppressing the ON voltage.
There are problems such as not being able to take sufficient measures to deal with institutional problems, and these problems need to be resolved.

Therefore, the purpose of the present invention is to suppress the ON voltage without using a diode, to significantly reduce costs and downsize, and to reliably resolve engine malfunctions.

[Means for solving problems]

Therefore, the present invention is characterized in that a part of the high voltage wiring circuit connected to the secondary winding of the ignition coil is physically interrupted.

Specifically, the high-voltage wiring circuit applies high voltage to the spark plug connected between the winding start terminal and winding end terminal of the secondary winding of the ignition coil.
A gap is provided to prevent spark discharge from occurring in response to the high voltage required to generate an ignition spark in the ignition plug, but not to produce spark discharge in response to the high voltage generated when the primary winding of the ignition coil is energized. The discharge gap parts are connected in series.

[Effect]

In the high-voltage wiring circuit that can apply high voltage to the spark plug connected to the winding start terminal and winding end terminal of the secondary winding of the ignition coil, spark discharge occurs in response to the ignition voltage, and the ignition voltage 1/5~1/1 of
When the ON voltage is at a level of approximately 0, a discharge gap portion having a gap that does not cause spark discharge is connected in series. Therefore, although the ignition voltage is applied to the ignition plug by the discharge gap section, the ON voltage is cut off and not applied to the ignition plug.

〔Example〕

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

FIG. 1 shows a first embodiment of the present invention, and is an electrical circuit configuration diagram in which the present invention is applied to the coil distribution type direct distribution type ignition device shown in FIG.

Therefore, since parts corresponding to those in FIG. 5 are indicated by the same reference numerals as in FIG. 5, the configuration of the electric circuit connected to the secondary winding 30b side of the ignition coil 30 will be described.

One end of the high tension cord 50 is connected to the winding start terminal S of the secondary winding 30b of the ignition coil 30, and the other end of the high tension cord is connected to the input side terminal of the discharge gap section 80. One end of the high tension cord 51 is connected to the output side terminal of the discharge gap section 80, and the other end of the high tension cord 51 is connected to the positive electrode of the spark plug 200 of the No. 1 cylinder 100.

On the other hand, one end of the high tension cord 152 is connected to the winding end terminal E, and the other end of the high tension cord 152 is connected to the positive electrode of the spark plug 202 of the No. 4 cylinder 102.

Further, the negative electrodes of the spark plugs 200 and 202 are attached to the engine body and are at ground potential.

One end of a high tension cord 60 is connected to the winding start terminal S of the secondary winding 31b of the ignition coil 31, and the other end of the high tension cord 60 is connected to the input side terminal of the discharge gap section 80. There is. One end of the high tension cord 61 is connected to the output side terminal of the discharge gap part 80, and the other end of the high tension cord 61 is connected to the No. 3 cylinder 10.
It is connected to the positive electrode of the spark plug 201 of No. 1. On the other hand, one end of the high tension cord 153 is connected to the winding end terminal E, and the other end of the high tension cord 153 is connected to the positive electrode of the spark plug 203 of the No. 2 cylinder 103.

Further, the negative electrodes of the spark plugs 201 and 203 are attached to the engine body and are at ground potential.

In this case, a discharge gap portion 80 is connected in series to the winding start terminal S side of each of the secondary windings 30b and 31b, but the discharge gap 80 may be connected in series to the winding end terminal E side.

FIG. 3 shows an example of the discharge gap part 80, and its cross-sectional view is shown. A metal cap 82 is attached to one opening side of a hollow cylindrical member 81 made of a transparent resin material with high electrical insulation. A metal cap 83 is fitted onto the other opening side, respectively. A terminal portion connected to a conductor of a high tension cord is fitted into these metal caps 82, 83. Discharge electrodes 86 and 87 are screwed into the bottoms 84 and 85 of the metal caps 82 and 83, and since the hollow cylindrical member 81 is transparent, the gap g can be finely adjusted from the outside with a screw. There is.

The gap g of the discharge gap portion 80 must be set to ensure that no spark discharge occurs due to the ON voltage.

In order to prevent the discharge electrodes 86 and 87 of the discharge gap 80 from oxidizing, the gap 88 may be filled with an inert gas (for example, N ₂ ).

This discharge gap part 80 can be connected between high tension cords as shown in FIG.
It can also be connected between the high tension cord and the positive electrode of the ignition plug, and between the high tension cord and the secondary winding terminals S and E of the ignition coil.
In addition, if it is necessary to prevent radio wave noise in the discharge gap portion 80, this can be easily done by covering the outer periphery of the hollow cylindrical member 81 with a conductive braid or the like.

Next, the operation of the first embodiment will be explained.
When an electric signal is generated from the No. 1 and No. 4 cylinder ignition signal generation circuits 33 and the transistor 35 is turned on, the primary winding 30a of the ignition coil 30 has a signal as shown in FIG. 4a. A current _I1 flows, and an ON voltage as shown by the arrow P in FIG. 3B is generated in the secondary winding 30b. However, this
The ON voltage is ON when the gap g of the discharge gap part 80 is ON.
Since the voltage level (for example, 1Kv to 2Kv) is set so as not to cause spark discharge, no voltage is applied to the spark plugs 200 and 202.

Furthermore, when the transistor 35 is turned off,
An ignition voltage as shown by arrow Q in FIG. 4b is generated in the secondary winding 30b. When this ignition voltage is generated between the winding start terminal S and the winding end terminal E of the secondary winding 30b, the discharge gap portion 80 generates a spark discharge and the ignition voltage is applied to the spark plugs 200, 202. The spark plugs 200, 202 discharge and generate an ignition spark. In this case, No. 1 cylinder 1
Since cylinder No. 00 is in the compression stroke, it ignites and enters the explosion stroke, but cylinder No. 4 is in the exhaust stroke, so it enters the intake stroke without igniting. Therefore, spark plug 2
Even if 00 and 202 cause spark discharge at the same time,
Only the No. 1 cylinder 100 is ignited, and the No. 4 cylinder 102 is not ignited.

Next, when the transistor 36 turns on,
As described above, an ON voltage is generated in the secondary winding 31b. This ON voltage is the discharge gap 80
, so that no voltage is applied to spark plugs 201 and 203.

Furthermore, when the transistor 36 is turned off,
An ignition voltage is generated in the secondary winding 31b. When this ignition voltage is generated in the secondary winding 31b, a spark discharge is generated in the discharge gap portion 80, and the ignition voltage is applied to the ignition plugs 201 and 203, so that each discharges and generates an ignition spark. In this case, the No. 3 cylinder 101 is in the compression stroke, so it ignites and enters the explosion stroke, but the No. 2 cylinder 103 is in the exhaust stroke, so it does not ignite and enters the intake stroke. Therefore, even if spark plugs 201 and 203 simultaneously generate spark discharge, only No. 3 cylinder 101 will ignite, and No. 3 cylinder 101 will ignite.
The second cylinder 103 is designed not to ignite. From now on, repeat the same operation and install No. 4 cylinder 10.
2, No. 2 cylinder 103 is ignited in this order.

In the case of this embodiment, a discharge gap part 80 having a simple structure as shown in FIG. Since they are connected in series to prevent ON voltage from being applied to the spark plugs 200, 202 and 201, 203, expensive components that require high withstand voltage and heat resistance can be replaced with inexpensive components with a simple structure. Not only can it be used as a substitute, but it can also reliably prevent ignition before the optimal ignition timing caused by ON voltage, making it possible to significantly reduce costs and downsize, as well as eliminate engine malfunctions.

FIG. 2 shows a second embodiment of the present invention, and is an electrical circuit configuration diagram in which the present invention is applied to the diode distribution type direct distribution type ignition device shown in FIG. 6.

Therefore, since parts corresponding to those in FIG. 6 are indicated by the same reference numerals as in FIG. 6, the circuit configuration connected to the secondary winding 40b side of the ignition coil 40 will be described.

One end of a high tension cord 70 is connected to the winding start terminal S of the secondary winding 40b of the ignition coil 40, and the other end of the high tension cord 70 is connected to the input side terminal of the discharge gap section 80. . One end of a high tension cord 71 is connected to the output side terminal of the discharge gap section 80, and the other end of the high tension cord 71 is connected to the branch terminal 7.
3, the high tension code 71a is connected to the spark plug 200 of the No. 1 cylinder 100 via the diode 43, and the high tension code 71b is connected to the No. 3 cylinder 1 via the diode 44.
01 spark plugs 201, respectively.

On the other hand, at the winding end terminal E of the secondary winding 40b,
One end of the high tension cord 74 is connected, the other end of the high tension cord 74 is branched into 74a and 74b at a branch terminal 75, and the high tension cord 74a is connected to the spark plug 203 of the No. 2 cylinder 103 via the diode 45. The high tension cords 74b are connected to the spark plugs 202 of the No. 4 cylinder 102 via the diodes 46, respectively. Further, the negative electrode sides of the spark plugs 200 to 203 are attached to the engine body and have a ground potential.

In this case, the discharge gap part 80 is connected in series to the winding start terminal S side of the secondary winding 40b, but the discharge gap part 80 may be connected in series to the winding end terminal E side.

Next, the operation of the second embodiment will be explained.
The polarity of the high voltage generated in the secondary winding 40b is reversed when the transistors 35 and 36 are in the ON and OFF states, so the high voltage generated in the No. 1 cylinder 100 and the No.
When applying the ignition voltage to the 4th cylinder 102, the winding start terminal S is at a positive potential, the winding end terminal E is at a negative potential, the No. 3 cylinder 101 and the No. 2 cylinder 103.
When applying the ignition voltage to the winding terminal S, the winding start terminal S is set to a negative potential and the winding end terminal E is set to a positive potential.

On the other hand, since the polarity of the ON voltage generated in the secondary winding 40b when the transistors 35 and 36 are in the ON state is opposite to the polarity of the ignition voltage, No. 1
When the ignition voltage is applied to the No. 4 cylinders 100 and 102, the ON voltage has the polarity as applied to the No. 3 and No. 2 cylinders 101 and 103, and
When the ignition voltage is applied to the No. 3 and No. 2 cylinders 101, 103, the ON voltage is applied to the No. 1 and No. 4 cylinders.
The polarity is such that it is applied to the cylinders 100 and 102. With such timing and polarity, the secondary winding 4
The ON voltage generated at 0b is the discharge gap part 80.
spark plugs 200-2.
03 is not applied. However, if the discharge gap part 80 is not provided, for example, before the No. 1 cylinder 100 in the compression stroke is ignited by the ignition voltage, the No. 3 cylinder 101 at the end of the intake stroke is turned on. There is a risk of ignition due to the voltage, causing engine malfunction.

On the other hand, the gap g of the discharge gap part 80 is set so as to generate a spark discharge in response to the ignition voltage generated in the secondary winding 40b, so that the spark plugs 200 to 203 have the required ignition timing. The ignition voltage is reliably applied to the

[Effect of idea]

According to the present invention, the discharge gap section is connected in series with the high voltage wiring circuit for applying high voltage to the spark plug connected between the winding start terminal and the winding end terminal of the secondary winding of the ignition coil. Since the ON voltage is not applied to the spark plug by connecting it, expensive parts that require high withstand voltage and heat resistance can be replaced with inexpensive parts with a simple structure, and the ignition phenomenon caused by the ON voltage can be replaced. Since this can be reliably prevented, it is possible to significantly reduce costs and downsize, and also to eliminate engine malfunctions.

[Brief explanation of drawings]

FIG. 1 is an electric circuit configuration diagram showing a first embodiment of the present invention, FIG. 2 is an electric circuit configuration diagram showing a second embodiment of the present invention, and FIG. FIG. 4, which is a sectional view of the discharge gap used in the illustrated embodiment, is an explanatory diagram of current and voltage waveforms in the primary winding and secondary winding of the ignition coil. 5 to 7 show conventional examples of the present invention, FIG. 5 is an electrical circuit diagram of a direct distribution type ignition device using a coil distribution method, and FIG. 6 is a diagram of a direct distribution type ignition device using a diode distribution method. FIG. 7 is an electrical circuit diagram of an ignition device using a power distribution mechanism. 30, 31, 40...Ignition coil, 3
0a, 31a, 40a...Primary winding, 30b,
31b, 40b... Secondary winding, S... Winding start terminal, E... Winding end terminal, 35, 36... Transistor, 43, 44, 45, 46... Diode,
50, 51, 60, 61, 70, 71, 71a,
71b, 74, 74a, 74b...high tension cord, 80...discharge gap section, 100...
No.1 cylinder, 101...No.3 cylinder, 102...No.4
Cylinder, 103...No.2 cylinder, 152,153...
High tension cord, 200, 202, 20
1,203...Spark plug.

Claims (1)

[Scope of utility model registration request] In an ignition system for a multi-cylinder internal combustion engine, the high voltage generated from the secondary winding of the ignition coil is directly distributed to the spark plugs of each cylinder by means of a high tension cord. In the high voltage wiring circuit for applying high voltage to the spark plug connected between the winding start terminal and the winding end terminal of the next winding, a spark discharge is generated for the high voltage that generates the ignition spark in the spark plug. arises,
A direct distribution type ignition device characterized in that discharge gap portions are connected in series and are spaced apart so that no spark discharge occurs in response to high voltage generated when the primary winding of an ignition coil is energized.