JPS5836188B2 - Ignition system for multi-cylinder internal combustion engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a current cut-off type ignition device for a multi-cylinder internal combustion engine that ignites a three-cylinder or six-cylinder internal combustion engine.

There is a current interrupt type non-contact ignition system for multi-cylinder internal combustion engines that does not use a distributor, which is equipped with an ignition coil for each cylinder and a circuit that controls the primary current of this ignition coil. This type of ignition system has the disadvantage of requiring a large-capacity power source because the constant current consumption is double the number of cylinders, and it cannot be applied to motorcycles etc. that do not have space to mount a large generator and battery. Ta.

In addition, in this type of ignition system, control signals are obtained from separate signal coils for low speed and high speed to obtain predetermined advance angle characteristics, but in a current cutoff type ignition system, the ignition position is In order to turn on the semiconductor switch for primary current control in front of the switch and then cut it off, a signal coil is required to generate a conduction signal and a cutoff signal at low speed and high speed, respectively. The disadvantage was that if only the number of cylinders were provided, the generator would be significantly larger.

An object of the present invention is to reduce current consumption, especially at low speeds, and to provide a multi-cylinder internal combustion engine that can perform predetermined ignition operations by simply providing one high-speed signal coil and one low-speed signal coil for each cylinder. The purpose of this invention is to provide an ignition device for

DESCRIPTION OF THE PREFERRED EMBODIMENTS The ignition device of the present invention will be explained in detail below with reference to the illustrated embodiments.

FIG. 1 generally shows the overall configuration of the present invention.
In the figure, lu, 1v and 1w are first, second and third ignition coils each having a primary coil 1p and a secondary coil 1s, and P1 to P3 are secondary coils of the first to third ignition coils, respectively. The first to third spark plugs are loaded for 1 s.

The first to third spark plugs are attached to the first to third cylinders of the engine, and in this example, ignition is performed in the order of first cylinder → second cylinder → third cylinder. .

2u, 2v and 2w are the first, second and third 1, respectively
Next current control semiconductor switches (hereinafter referred to as first to third semiconductor switches).

), these switches are connected in series with the primary coils 1p of the first to third ignition coils, respectively.

The series circuits of the primary coils of the first to third ignition coils 1u to 1w and the first to third semiconductor switches 2u to 2W are connected in parallel to each other, and a switch 3 is connected to both ends of each of these series circuits. DC ignition power supply 4 such as a battery via
The output of is applied.

5u, 5v and 5w are semiconductor switches 2u and 2, respectively.
The first to third control circuits control V and 2W, and each control circuit has an ON terminal and an OFF terminal to which a conduction command signal and a cutoff command signal, which will be described later, are respectively input. When each signal is applied, the corresponding semiconductor switch is controlled to be turned on and off.

6u to 6w and 7u to 7w are first to third low speed timing signals LU to Lw that determine the first to third ignition positions at low speed and high speed of the engine, respectively.
and first to third high-speed timing signals HU to HW.
The first to third low-speed signal coils and the first to third high-speed signal coils generate signals, and these signal coils are, for example, magnet field rotation type or inductor rotation type signal generators that rotate synchronously with the engine. placed inside the aircraft.

8u to 8w are first to third shutoff command OR circuits into which first to third low-speed timing signals LU to Lw and first to third high-speed timing signals HU to Hw are input, respectively; These OR circuits apply first to third cutoff command signals Ju to Jw to the OFF terminals of first to third control circuits 5u to 5w, respectively.

9u to 9w are the first to third conduction command signals Ku7 to the ON terminals of the first to third control circuits 5u to 5w, respectively.
The third low-speed timing signal Lw and the second high-speed timing signal Hv are input to the first to third conduction command OR circuits 9u that give Kw from '7 to Kw. has been done.

Further, the first low speed timing signal Lu and the third high speed timing signal Hw are input to the second conduction command OR circuit 9v, and the second low speed timing signal Hw is input to the third conduction command OR circuit 9w. A timing signal Lv and a first high-speed timing signal Hu are input.

In the above device, when the crankshaft of the engine rotates, low-speed timing signals Lu to Lw are generated in the first to third low-speed signal coils 6u to 6w, respectively, as shown in FIG. 2a, c, and e. , high-speed timing signals Hu, Hv, and Hw are generated in the first to third high-speed signal coils 7u to 7w, respectively, as shown in FIG. 2b, d, and f.

Here, the low speed timing signal Lu-Lw has a relatively narrow width and has a high peak value even at low speeds, and when these signals Lu-Lw occur at low speeds, the OR circuits 8u~
Shutoff command signal Ju- output from 8w and 9u to 9w
Jw and conduction command signal Ku-Kw are connected to control circuits 5u to 5w.
It has reached a level where it can operate.

On the other hand, the high-speed timing signal Hu-Hw has a relatively wide width and is ahead of the low-speed timing signal in phase, but its peak value is sufficiently low at low speeds, and these high-speed timing signals are generated at low speeds. OR circuit 8
Command signal JU- output from u~8w and 9u~9w
Jw and KU-KW are designed so that they do not reach a level that causes the control circuits 5u to 5w to operate.

In FIG. 2, the horizontal axis indicates the rotation angle of the engine crankshaft.

Further, in the following description, it is assumed that the positive half cycle of each signal waveform is used as a timing signal.

In the example shown in Fig. 2, when the engine is running at low speed, the first
The high-speed timing signal Hu (shown as a solid line in FIG. 2b).

) occurs, this signal is input to the OR circuits 8u and 9w, but as mentioned above, at low speeds, the level of this high speed timing signal Hu is low, so the cutoff command signal J
u and conduction command signal Kw do not reach a level that operates control circuits 5u and 5w.

Next, when the first low-speed timing signal LU is generated at the angle θ2, this signal is input to the first cutoff command OR circuit 8u and the second conduction command OR circuit 9v, and is output from these OR circuits. The cutoff command signal Ju and conduction command signal K■ are respectively set at an angle θ2' slightly delayed from the angle θ2.
reaches a level at which the control circuits 5u and 5v are operated.

Similarly, when the engine is at low speed, the angles θ and θ
6, the second and third low-speed timing signals L■ and Lw
When the command signal JV. occurs, the command signal JV. Kw and Jw
．． KU is the control circuit 5v, 5w and 5w, 5u, respectively.
reach a level where it works.

Therefore, when the engine is at low speed, the first conduction command signal Ku operates the control circuit 5u at the angle θ6', and the first conduction command signal Ku operates the control circuit 5u.
By making the semiconductor switch 2u conductive, WE, 2 Figure g
As shown by the solid line, the primary current ■ is applied from the power source 4 to the first ignition coil 1u.

flow. Next, at the angle θ2', the first cutoff command signal J
u operates the control circuit 5u and the first semiconductor switch 2
Cut off u and the primary current of ignition coil 1u ■.

to zero. This sudden change in current causes a large magnetic flux change in the iron core of the ignition coil 1u, inducing a high voltage in the secondary coil 1s, causing a spark to fly to the ignition plug P, causing the first ignition.

Also, at this angle θ2', the second conduction command signal K■ reaches the operating level of the control circuit 5v, so the second semiconductor switch 2v becomes conductive, and a primary current flows through the ignition coil 1v.

Next, at the angle θ,', the second cutoff command signal Jv operates the control circuit 5v to cut off the second semiconductor switch 2v, generates a high voltage in the secondary coil 1S of the ignition coil 1v, and switches the second Have them light the fire casually.

At this angle θ,', the third conduction command signal K
In order for w to operate the control circuit 5w, the third semiconductor switch 2W is made conductive and the primary current flows through the third ignition coil 1W.

Next, at an angle θ6', the third cutoff command signal Jw operates the control circuit 5W to cut off the third semiconductor switch 2W and cause the third simple ignition to occur.

Further, at this angle θ6', the first conduction command signal Ku operates the control circuit 5u and makes the first semiconductor switch 2u conductive.

Thereafter, similar operations are repeated, and the first to third cylinders of the engine are ignited in sequence.

Next, in the high-speed rotation region of the engine, the peak value of the high-speed timing signal increases, and each high-speed timing signal causes each command signal to reach a level that operates the control circuit, so the conduction position of each semiconductor switch and the cutoff position (ignition position) are determined by each high-speed timing signal.

That is, at the angle θ1, the first high-speed timing signal H
occurs, the first cutoff command signal Ju reaches a level that operates the control circuit 5u at an angle θ1' whose phase is slightly delayed from this angle θ1, and the first cutoff command signal Ju reaches a level that operates the control circuit 5u, cutting off the first semiconductor switch 2u and turning on the first ignition. A high voltage is generated in the secondary coil of coil 1u.

Also, at the angle θ1', the third conduction command signal Kw
In order to reach a level that operates the control circuit 5w, the third semiconductor switch 2W is made conductive, and the third ignition coil 1w is turned on.
A primary current is passed through.

Next, at the angle θ3, the second high-speed timing signal Hv
occurs, an angle θ3 slightly delayed from this angle θ3
', the second cutoff command signal Jv and the first conduction command signal Ku are applied to the second and first control circuits 5v and 5, respectively.
u reaches the level where it operates, and the second semiconductor switch 2
v is cut off, and the first semiconductor switch 2u becomes conductive.

As a result, a high voltage is generated in the secondary coil of the second ignition coil 1v, ignition is performed in the second cylinder, and a primary current ■ is generated in the first ignition coil 1u.

flows. Next, when the third high-speed timing signal Hw is generated at the angle θ, the third cutoff command signal Jw and the second conduction command signal K are generated at the slightly delayed angle θ,′.
v reaches a level that operates the third and second control circuits 5w and 5v, respectively, the third semiconductor switch 2w is cut off, and the second semiconductor switch 2v is turned on.

As a result, a high voltage is generated in the secondary coil of the third ignition coil 1w, and ignition is performed in the third cylinder.

Thereafter, similar operations are repeated, and the ignition position of each light is determined by the high-speed timing signal.

In this case, the high-speed timing signal has a wide width, and as the peak value increases as the rotational speed increases, the phase at which each cutoff command signal reaches the level that operates the control circuits 5u to 5w progresses, so the rotational speed increases. An advance characteristic is obtained in which the ignition position advances as the ignition position advances.

As is clear from FIG. 2, in the apparatus of the present invention,
Since the primary current always flows through one ignition coil at low speeds, power consumption can be reduced in the low speed range where the output of the generator is low.

Furthermore, in the high speed range, the primary current is passed through each ignition coil for a longer period of time than in the low speed range, so that sufficiently large energy can be given to the ignition coils, and sufficient ignition performance can be obtained.

Next, FIG. 3 shows a gate turn-off switch (hereinafter referred to as GTO) as the first to third semiconductor switches.

) shows a specific example of the present invention using.

In this figure, parts that are equivalent to those in FIG. 1 are given the same reference numerals.

The GTO constituting the first semiconductor switch 2u is connected in series with the primary coil of the ignition coil 1u, and a thyristor Th is connected in parallel between the gate and cathode of this GTO via a capacitor C1.

A pnph transistor Tr is connected via a diode D1 to the connection point between the capacitor C and the anode of the SIRISK Th.
The collector of the transistor Tr1 is connected to the transistor Tr1, and the emitter of the transistor Tr1 is connected to the DC power supply 4 via the switch 3.

The collector of the transistor Tr is also connected to G via the resistor fl.
When the transistor Tr1 becomes conductive, an ignition signal is applied from the power source 4 to the GTO via the transistor Tr and the resistor R1, and the capacitor CI is connected to the polarity shown in the figure via the diode D1. It is now being charged.

The base of the transistor Tr1 is connected to the np via the resistor R2.
It is connected to the collector of the n-transistor Tr2, and the emitter of the transistor Tr2 is connected to the cathode of the GTO2u.

Above capacitor C, thyristor Th, transistor T
A first control circuit 5u is constituted by r,,Tr2, diode D1, and resistors R,,R2.

The OFF terminals of this control circuit 5u are the gate and cathode of the thyristor Th, and a first low-speed signal coil 6u is connected between these OFF terminals via a first cutoff command OR circuit 8u consisting of diodes D2 and D3. and the output of the first high-speed signal coil 7u are applied.

The ON terminals of the control circuit 5u are the base and emitter of the transistor Tr2, and a third low-speed signal coil 6w is connected between these ON terminals via a first conduction command OR circuit 9u consisting of diodes D4 and D5. And the output of the second high-speed signal coil 7v is applied.

The respective control circuits and OR circuits corresponding to the other second and third ignition coils are similarly configured, and the output of the signal coil is input to each OR circuit in the same manner as shown in FIG.

In the embodiment of FIG. 3, for example, the transistor T' of the first control circuit 5u is passed through the first conduction command OR circuit 9u.
When a signal is applied between the pace emitters of the transistor Tr2 (between the ON terminals), the transistor Tr2 becomes conductive and the transistor Tr2 becomes conductive.
A base current flows through 1.

As a result, the transistor Tr1 becomes conductive, and the GTO is connected from the DC power supply 4 through the transistor Tr1 and the resistor R1.
An ignition signal is given to (first semiconductor switch) 2u.

Therefore, GTO 2u becomes conductive and primary current flows through ignition coil 1u.

At this time, a current flows through the transistor Tr1, the diode D1, the gates and cathodes of the capacitor CI and GTO2u, and the capacitor C1 is charged to the polarity shown.

Next, when a signal is applied between the gate cathode (between the OFF terminals) of the thyristor Th through the first cutoff command OR circuit 8u, the thyristor Th becomes conductive, and the voltage across the capacitor C1 is applied to the gate cathode of the GTO 2u through the thyristor Th. Applied in the opposite direction.

Therefore, the GTO 2u is cut off, the primary current of the ignition coil 1u is cut off, a high voltage is induced in the secondary coil of the ignition coil, and a spark is generated in the ignition plug P1.

The operation of the control circuits corresponding to the other ignition coils is exactly the same.

The related operations of each control circuit when the engine runs at low speeds and at high speeds are the same as those described with reference to FIG. 1, and therefore their explanations will be omitted.

FIG. 4 shows an embodiment in which transistors are used as the first to third semiconductor switches. In this embodiment, flip-flop circuits are used as the first to third control circuits 5u to 5w, and the set terminal S of each flip-flop circuit is is used as an ON terminal, and the reset terminal R is used as an OFF terminal.

In the embodiment shown in FIG. 4, when a conduction command signal is applied to the set terminal S of the flip-flop circuit controlling the control circuits 50 to 5w, the high level outputs obtained from these flip-flop circuits cause the transistors 2u to 2w to be activated. When the base current flows and these transistors conduct, and when a cutoff command signal is given to the reset terminal R, the output of the flip-flop circuit is inverted, causing the transistors 2u to 2w to be cut off and the secondary of the ignition coils 1u to 1w to be turned off. High voltage is generated on the side.

Other operations are similar to those described with reference to FIG.

In each of the above embodiments, one spark plug is connected to the secondary coil of each ignition coil, but as shown in FIG. 5, two spark plugs are connected to the secondary coil 1s of each ignition coil. It is also possible to ignite a six-cylinder internal combustion engine by adopting a so-called simultaneous ignition system that applies a load of .

In this case, the cylinder in which two spark plugs that generate sparks at the same time are installed must satisfy the condition that when one spark plug is at the ignition timing, the other is at the end of the exhaust stroke.

As described above, according to the present invention, when the engine is running at low speed, the primary current flows only through one of the three ignition coils, and even when the engine is running at high speed, the primary current always flows through only two ignition coils. Since no current flows, power consumption can be reduced.

Moreover, since the primary current is passed through each ignition coil for a longer period of time when the engine is running at high speed than when the engine is running at low speed, the ignition performance at high speeds can be sufficiently improved, which has the advantage of increasing the output of the engine.

In addition, there is no need to provide both a conduction signal coil and a cutoff signal coil for each ignition coil, and it is sufficient to provide one signal coil each for low speed and high speed, making it possible to increase the size of the generator. It can be prevented.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the general configuration of the present invention, FIGS. 2 a to i are diagrams showing examples of signal waveforms of each part in FIG. 1,
3 and 4 are connection diagrams showing different specific embodiments of the present invention, respectively, and FIG. 5 is a connection diagram illustrating the main parts of the simultaneous ignition system. 1u to 1w...first to third ignition coils,
2u to 2w...First to third semiconductor switches for primary current control, 4...DC ignition power supply, 5u
5w to 5w...first to third control circuits, 6u to 6w...first to third low speed signal coils,
7u to 7w...First to third high speed signal coils, 8u to 8w...First to third OR circuit for cutoff command, 9u to 9w... 1st to 3rd
OR circuit for continuity command.

Claims (1)

[Scope of Claims] 1. The first to third ignition coils each generate a high voltage for ignition in the first to third order, and the 3-cylinder or 6-cylinder
In an ignition device for a multi-cylinder internal combustion engine that ignites a cylinder of an internal combustion engine, an ignition power supply that supplies a primary current to the first to third ignition coils, and one of the first to third ignition coils.
First to third primary current control semiconductor switches provided to control on/off of the secondary currents, and ignition at a low speed that is ignited by the first to third ignition coils. a signal generator that generates first to third low speed timing signals and first to third high speed timing signals that respectively determine the ignition position and the ignition position at high speed; and the first to third low speed timing signals. and a high-speed timing signal, respectively, and output first to third cut-off command signals;
a first conduction command OR circuit that outputs a first conduction command signal by inputting the low-speed timing signal of the third
a second conduction command OR circuit which receives the high speed timing signal and the first low speed timing signal as input and outputs a second conduction command signal; and the first high speed timing signal and the second low speed timing signal. a third conduction command OR circuit which receives the timing signal as input and outputs a third conduction command signal; and a third conduction command OR circuit which inputs the first to third conduction command signals and the cutoff command signal; For use in a multi-cylinder internal combustion engine, comprising first to third control circuits that conduct and cut off the first to third primary current control semiconductor switches, respectively, when signals are input, respectively. Ignition device. 2. The ignition device for a multi-cylinder internal combustion engine according to claim 1, wherein the first to third primary current control semiconductor switches are gate turn-off switches. 3. The first to third control circuits each include a switch circuit that provides a conduction signal to the gate turn-off thyristor when the conduction command signal is input, a capacitor that is charged via the switch circuit, and a switch circuit that provides the conduction signal to the gate turn-off thyristor when the conduction command signal is input. Claim 2, further comprising: a semiconductor switch for cut-off control which conducts when a signal is input and applies the voltage across the capacitor in the opposite direction between the gate cathode and the gate turn-off switch. The ignition device for a multi-cylinder internal combustion engine as described. 4. The ignition device for a multi-cylinder internal combustion engine according to claim 1, wherein the first to third semiconductor switches for primary current control are transistors. 5. The first to third control circuits each include a flip-flop circuit to which the conduction command signal and the cutoff command signal are input to a set terminal and a reset terminal, respectively, and become high level when the signal is applied to the set terminal. 5. The ignition device for a multi-cylinder internal combustion engine according to claim 4, wherein a base current is caused to flow through the transistor at the output to make the transistor conductive.