JPS5941340Y2 - internal combustion engine ignition system - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement in an internal combustion engine ignition system, particularly in an internal combustion engine ignition system in which the generating coil of a magnet generator is used as an electrode.

First, the conventional example shown in FIGS. 1 and 2 will be explained.
In the figure, 1 is a magnet generator, 1a is a flywheel rotated by the engine, and 1b and 1c are flywheels 1.
Permanent magnet 1b is magnetized in the radial direction by two permanent magnets and a pole each installed at equal intervals inside a.
Also, pole 1° is not magnetized.

1d is a generator iron core installed on the base of the magnet generator 10 (not shown), and its pair of pole faces face the permanent magnet 1b and the pole 1e through a gap.

1e is a power generation coil that also serves as the primary coil of the ignition coil wound around this iron core 1d, and outputs AC output, that is, output in one direction (a shown by a solid line) and the other direction (b shown by a broken line) with mutually different polarities. occurs.

1f is a secondary coil of the ignition coil similarly wound around the iron core 1d, and 2 is a switching element that is connected to both ends of the generator coil 1e and generates a high voltage by intermittent current flow in the direction a. transistor 1, 3 a second transistor that controls on/off the first transistor 2; 4 a first transistor;
a resistor for flowing base current to transistor 2,
5 and 6 are voltage dividing resistors for determining the operating point of the second transistor 3; 7 and 8 are resistors and diodes connected in series across the generator coil 1e; the generator coil is not energized by the first transistor 2; A series circuit is configured to bypass the b-direction current of 1e.

Next, the operation of this conventional example will be explained using a two-cycle engine as an example.

When the flywheel 1a is rotated by the engine, two cycles of output are generated in the generator coil 1e for one rotation of the engine, as shown by the dashed line in FIG. As shown in the figure, the voltage of the output in the a and b directions shown at port 41 is higher than the voltage 'of the output in the a and b directions shown at ports c and 2.

Now, at the ignition timing of the engine, the generator coil 1e is
When the a-direction voltage shown in a is generated, the base current flows through the resistor 4 to the first transistor 2, turning it on, and the energizing current in the a-direction of the generator coil 1e changes to the first transistor 2.
is short-circuited through transistor 2.

Then, when the ignition timing of the engine occurs and the terminal voltage of the resistor 6 divided by the voltage dividing registers 5 and 6 rises to a predetermined value, the base current flows through the second transistor 3 and the second transistor 3 is reversed from OFF to ON state. The base current of the first transistor 20 that had been flowing through the resistor 4 is bypassed through the second transistor 3, so that the first transistor 2 suddenly turns to the off state and cuts off the current flowing through the generating coil 1e. do.

This sudden change in current generates a high voltage in the secondary coil 1f, and the spark plug that is not rotated in response to this high voltage causes a spark discharge.

Next, when the generator coil 1e is used for ignition and a b-direction output is generated, this b-direction current is bypassed by a series circuit consisting of a resistor I and a diode 8 connected in parallel to both ends of the generator coil 1e. The b-direction voltage shown at 2 is suppressed by the resistor 7 to a small value shown from the dashed line to the solid line in FIG. 3I.

Here, a occurs at both ends of the generating coil 1e.

Considering the output in the b direction, as mentioned above, two cycles of AC output are generated in the generator coil 1e for one rotation of the engine, and a large portion of the output in the a direction that is used for ignition corresponds to the engine ignition timing. A high voltage is generated in the secondary coil 1f at voltage A, and no high voltage is generated at other small voltages.

Further, the b-direction output that is not used for ignition is bypassed by a series circuit consisting of a resistor 7 and a diode 8, and is eventually suppressed from the voltage port indicated by a dashed dot line, from a binary value to a voltage value indicated by a solid line.

By the way, when the series circuit consisting of the resistor 7 and the diode 8, that is, the load is not connected to the generating coil 1e,
A large voltage shown by the dashed line is generated in the generator coil 1e, and therefore, a high voltage is induced in the secondary coil 1f according to the change in the dog voltage (dotted chain line) of the generator coil 1e. In addition to the ignition timing, that is, before and after one ignition timing,
Unnecessary sparks will fly to the spark plug.

In particular, if an unnecessary spark occurs before the engine ignition timing, that is, during the engine intake and compression process, the gas inside the cylinder will
This, combined with low compression, causes combustion, which not only adversely affects the engine, but also causes the engine to become inoperable.

Therefore, by connecting a series circuit consisting of a resistor 7 and a diode 8 to both ends of the generator coil 1e, the b-direction voltage 2 generated before the normal ignition timing is suppressed to a small voltage that does not harden the spark plug. We try not to have a negative impact on the institution.

However, in this case, the b-direction voltage port 2 of the generator coil 18 is suppressed to the solid line voltage due to the heat consumption of the resistor 7, so the heat generation of the resistor 7 becomes extremely large. Due to the large size, the unit that is housed together with the transistors 2, 3 and other elements that constitute the ignition circuit becomes extremely large.

Furthermore, there is a risk that other elements may be destroyed by the heat generated by the resistor 7, and to solve this problem, new problems arise such as selecting a mounting position for the resistor 7 that has good heat dissipation, or making the unit a heat dissipation structure. do.

This invention was made to eliminate the above problems, and the output of the other polarity of the generator coil, which is generated before the engine's ignition timing, is bypassed and consumed by a resistor, suppressing it to a small value. The output of the other direction polarity generated after the ignition timing is bypassed by the semiconductor switching element without bypassing the resistor, and is configured to prevent consumption by the resistor, thereby preventing the generation of unnecessary sparks before the ignition timing. This is an internal combustion engine ignition device that can reduce the amount of heat generated by the register.

An embodiment of this invention will be described below with reference to FIG.

In FIG. 4, reference numeral 9 denotes a thyristor, which is a semiconductor switching element, connected in parallel to the series circuit of the resistor 7 and diode 8 in the generator coil 1e, and 11.12 the generator coil 1.
A voltage dividing register is connected to both ends of the power generating coil 1e through a diode 10 to detect the output in the other direction of the generating coil 1e, and together with the diode 10, a control circuit is configured.

The voltage dividing points of the voltage dividing registers 11 and 12 are connected to the gate of the thyristor 9.

The above thyristor 9, diode 10, and voltage dividing registers 11 and 12 constitute a bypass circuit 13.

Next, in explaining the operation, since the ignition operation is the same as in the conventional example, the explanation will be omitted, and the control operation of the output in the other direction which is not used for ignition of the generating coil 1e will be described in detail.

First, before the ignition timing of the engine, the b-direction voltage 2 generated starting from point A in Figure 8 (■) is caused to rise to a high level in the secondary coil 1f by the resistor 7 and diode 8 connected to the generator coil 1e, as shown by the solid line. The voltage is suppressed to a level so low that no voltage is generated.

In addition, the b-direction voltage generated starting from point B after the ignition timing is larger than voltage 2 due to the unequal magnetic pole structure of the magnet generator 1 as described above, and is shunted by the resistor 7 and diode 8. Then, as shown by the solid line, the voltage port' becomes larger than the voltage 2'.

Here, the trigger voltage H, which is sufficient to turn on the thyristor 9, is set to a value larger than the voltage 2', and the voltage dividing point voltage of the voltage dividing register 1L12 is set to obtain this trigger voltage.

When the b-direction voltage port is generated, it is initially bypassed by the resistor I and the diode 8, but the first partial voltage resistor 11.
When the voltage dividing point 12 increases and reaches the trigger voltage, the thyristor 9 is turned on, so that the current flowing through the resistor 7 and the diode 8 is bypassed by the thyristor 9 and flows.

Therefore, the current flowing through the resistor 7 decreases from the solid line area shown in FIG. 8 to the hatched area, and the heat generated by the resistor 7 due to power consumption is significantly reduced.

As a result, the heat generated by the register 7 can be made extremely small without generating unnecessary sparks, the unit can be made compact, and measures for heat resistance, heat radiation, etc. are not required.

In the above embodiment, since the thyristor 9 short-circuits the b-direction output of the generator coil 1e, the output of the generator coil 1e is short-circuited.
If the short-circuit current in the b direction affects the output in the a direction, which is used for ignition, due to the armature reaction in e, connect a resistor 14 shown by a dotted line in series with the thyristor 9 to the extent that it does not affect the output in the a direction. It is also possible to adjust.

Further, in this embodiment, a transistor is used to interrupt the current flow of the generator coil 1e, but a mechanical interrupter may also be used, and the generator coil 1e is an independent coil that does not also serve as the primary coil of the ignition coil. It is also possible to use

Further, the thyristor 9 may be replaced with another semiconductor switching element such as a transistor, and although the description has been made for a two-cycle engine, the same effect can be obtained even when applied to a four-cycle engine.

As described above, according to this invention, the generator coil is configured to generate alternating current outputs with different polarities and different magnitudes for one cycle or more, and the generator coil is used for ignition of the generator coil.
Energize the resistor to suppress the output of the polarity in the other direction,
Since the configuration is such that the ignition is performed before the ignition timing, and the bypass circuit is used to bypass the ignition after the ignition timing, it is possible to reliably prevent unnecessary sparks from occurring before the ignition timing, allowing the engine to ignite properly, and significantly reducing the heat generated by the register. A remarkable effect in practical use can be obtained by reducing the amount of water.

[Brief explanation of the drawing]

Figure 1 is the constituent countries of the magnet generator, Figure 2 is an ignition circuit diagram showing a conventional example, Figure 3 is a voltage waveform diagram of the generator coil 1e, and ■
4 is a current waveform diagram of the generating coil 1e, and FIG. 4 is an ignition circuit diagram showing an embodiment of this invention. In the figure, 1e is a power generation coil, 1f is a secondary coil, 2
,3 is a transistor,4,5,6,7゜11.12,1
4 is a resistor, 8.10 is a diode, 9 is a thyristor, and 13 is a bypass circuit. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A power generating coil that generates alternating current outputs of different magnitudes for one cycle or more with different polarities in synchronization with the rotation of an engine, and controlling the output of one polarity of the alternating current output of this power generating coil to the ignition timing of the engine. a switching element that generates a high voltage in the secondary coil of the ignition coil; a resistor that bypasses and suppresses the output of the other polarity of the AC output generated in the generator coil before the ignition timing; It has a detection means for detecting that the output of the other polarity among the AC outputs generated in the generator coil after the ignition timing has reached a set value or more, and a circuit closing means for closing the circuit by detecting this, An internal combustion engine ignition device comprising a bypass circuit that bypasses the current flowing through the resistor when the output of the polarity in the other direction reaches a set value or more.