JPS6318779Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a current interrupting type ignition device for an internal combustion engine.

[Prior Art] In a current interrupting type ignition device for an internal combustion engine,
A current control switch and a primary coil of the ignition coil are connected in parallel to an ignition power supply coil provided in a magnetic alternating current generator driven by the engine. In this ignition system, by changing the current control switch from a conductive state to a cutoff state at the ignition position of the engine, the current flowing from the ignition power supply coil through the current control switch is interrupted, and a high voltage is applied to the ignition power supply coil. This voltage is further boosted by the ignition coil to obtain the high voltage necessary to generate the ignition spark.

In this type of ignition system, the ignition operation is performed when the current flowing from the ignition power supply coil through the control switch reaches a sufficient level during the positive half cycle of the ignition power supply coil, so the engine rotational speed increases. If the ignition position is to be advanced in accordance with the ignition position, the angular width (mechanical angle) of the half cycle of the output of the ignition power supply coil must be made large enough to correspond to the advance angle width. Generally, magnet generators have built-in generator coils for ignition and battery charging in addition to the ignition power supply coil, and it is necessary to make the output of these generator coils sufficiently high.
It is often configured with multiple poles such as 4 poles or 6 poles. Therefore, when the ignition power supply coil is configured with a single power generation coil, it is unavoidable that the width of the half cycle of the output becomes narrow, and if a single power generation coil is used as the ignition power supply coil, the advance angle will not be sufficient. I can't take the width. Therefore, there is a low-speed generator coil with a relatively large inductance that generates the output necessary for ignition operation in the low-to-medium speed range of the engine, and a high-speed generator coil with a lower inductance than the low-speed generator coil that generates the necessary output in the mid-to-high speed range of the engine. An ignition device has been proposed in which a predetermined advance angle width is obtained by providing a power generating coil and a power generating coil with a phase shift and connecting these generating coils in series to form an ignition power source coil.

Figure 1 shows the configuration of this already proposed ignition system, in which 1 is the primary coil 1a.
and an ignition coil having a secondary coil 1b, 2 is 2
A spark plug connected to the secondary coil 1b; 3 an ignition power supply coil configured by connecting low-speed power generation coils 31a, 31b and a high-speed power generation coil 32 in series; 4 a spark plug connected to the primary coil 1a and the ignition power supply coil 3; This is a current control switch connected in parallel. Here, the low-speed generating coil 31a and the high-speed generating coil 31b are connected to the output voltage of the low-speed generating coil.
Section where V ₁ is in negative half cycle (rotation angle range)
The respective phase relationships are set so that there is an overlapping portion between V 2 and the section where the output voltage V ₂ of the high-speed generator coil is in the positive half cycle.

The generating coils 31a, 31b and 32 are provided, for example, in a multi-polar magnetic AC generator as shown in FIG. In the figure, 5 is an 8-pole flywheel magnet rotor in which 8 permanent magnets 7a to 7h are fixed to the inner periphery of a cup-shaped flywheel 6, and 8 is a 12 salient pole part from an annular yoke part 81. 82a-82l
The low-speed generating coils 31a and 31b each have salient pole portions 82 in the same phase.
d and 82a, the high-speed generating coil 32
is wound around the salient pole portion 82b which is 120 degrees ahead of the salient pole portions 82a and 82d in phase. A power generating coil for lighting, battery charging, etc. is wound around the other salient poles of the iron core 8. The iron core 8 is fixed to a base plate provided on the case or cover of the engine, and the magnet rotor 5 is attached to the output shaft of the engine and driven to rotate in the direction of the arrow shown.

Low-speed power generation coils 31a, 31 connected in series
The waveforms of the output voltage V ₁ obtained from b and the output voltage V ₂ of the high-speed generator coil 32 are shown in FIG. 4A with respect to the rotation angle θ of the engine, and the voltage V _{2 is} The predetermined angular phase is advanced.

The current control switch 4 is a well-known switch that is controlled to be conductive when the output voltage of the positive half cycle of the ignition power supply coil rises, and then to be in a cut-off state at the ignition position. As this switch, a circuit breaker controlled by a cam may be used.
No. 11341, JP-A-54-16032, etc., a transistor whose collector-emitter circuit is connected in parallel to the ignition power supply coil, and a positive half-cycle output of the ignition power supply coil are used to connect the transistor to the ignition power supply coil. In some cases, a transistor switch is used, which is comprised of a circuit that allows a base current to flow through the transistor, and a circuit that turns off the transistor when a signal indicating the ignition position of the internal combustion engine is applied. In the illustrated example, a transistor switch is used as the current control switch 4.

The current control switch 4 becomes conductive when the voltage across the ignition power supply coil 3 becomes a positive half cycle (the half cycle in which the non-grounded terminal becomes positive in Fig. 1), and becomes a cutoff state at the ignition position. controlled so that Therefore, when voltages V ₁ and V ₂ with waveforms as shown in FIG. 4A are generated, |V ₂ |>|
The switch 4 becomes conductive at the angle θ _a where V ₁ |
A short circuit current I _1a as shown in Figure B flows, and this current is interrupted at the ignition position to perform the ignition operation.
In this case, the cut-off value of the current I _1a is not arbitrary; in order to obtain the specified ignition performance, the current _{I 1a} must be shut off, and in the illustrated case, the ignition operation cannot be performed at a position where the phase is more advanced than the angle θ ₁ ' where l _1a is equal to the set value _inio . On the other hand, in order to improve the ignition performance at low speeds of the engine, it is necessary to perform the ignition operation at an angle θ ₂ that maximizes I _1a at low speeds. Therefore, in this case, the range of angles at which ignition can be performed is between θ ₁ ′ and _{θ 2} , and when the engine rotational speed (rpm) is from N _{1 to}
Assuming that the cut-off position of the current control switch 4 is controlled so that the ignition position advances linearly while changing to N ₂ (>N ₁ ), the change in the ignition position θi with respect to the rotational speed N is as shown by the broken line in Fig. 5. As shown in a,
The advance angle width is α. In addition, TDC in the figure is the top dead center of the engine.

[Problems to be solved by the invention] According to the ignition system shown in FIG. Even this advance angle α was sometimes insufficient, and the engine's demands could not be fully met.

The object of the present invention is to provide an ignition device for an internal combustion engine which has a wider rotation angle range in which a predetermined cut-off current value can be obtained than in previously proposed ignition devices, thereby enabling a wider advance angle range.

[Means for Solving the Problems] The present invention includes an ignition power supply coil configured by connecting a high-speed power generation coil and a low-speed power generation coil in series, and an internal combustion power supply coil provided in parallel to the ignition power supply coil. A low-speed engine is equipped with a current control switch that is controlled from a conductive state to a cutoff state at the ignition position of the engine, and an ignition coil that boosts the voltage induced in the ignition power supply coil when the current control switch is cut off. The phases of the high-speed power generation coil and the low-speed power generation coil are adjusted such that a section in which the output voltage of the power generation coil is in a negative half cycle and a section in which the output voltage of the high speed power generation coil is in a positive half cycle overlap. The relationship is set, and the ignition position is set in an area where the current flowing from the ignition power supply coil through the current control switch is equal to or higher than the set position due to the positive half-cycle output of the high-speed generator coil and the low-speed generator coil. In an ignition system for an internal combustion engine, the advance angle width can be set wider than that of previously proposed ignition systems.

Therefore, in the present invention, a diode is provided which is connected in parallel to the low-speed generating coil and short-circuits the output of the negative half cycle of the low-speed generating coil.

The high-speed power generation coil and the low-speed power generation coil may each be composed of a single power generation coil or a plurality of power generation coils.

[Operation of the invention] With the above configuration, the position at which the output voltage rises in the positive half cycle of the ignition power supply coil (the half cycle in which current flows through the current control switch) can be advanced. The phase at which the flowing current reaches the set value can be advanced, and the range (rotation angle range) in which a predetermined current cutoff value can be secured can be made wider than before, making it possible to widen the advance angle width.

[Example] The present invention will be explained in detail below with reference to the illustrated example.

FIG. 3 shows an embodiment of the present invention, and the difference from FIG. 1 in this figure is that the negative half cycle ( This is the point where the diode 10 is connected in a direction that short-circuits the output of the half cycle in which the ground side terminal of the generating coil 31b becomes positive. The embodiment shown in FIG. 3 is configured in exactly the same way as the circuit shown in FIG. 1 except for the above points, and the generating coil 31
a, 31b and 32 are provided in a multi-pole magnet generator as shown in FIG.

With the above configuration, low speed generator coil 1
3a, 13b in the negative half cycle becomes low as shown by the broken line in Fig. 4, the non-grounded terminal of the ignition power supply coil ₃ becomes a positive potential with respect to the ground. The position where the cycle starts (｜V ₂ ｜
>|V ₃ |) is a position at an angle θ _b that is more advanced than the angle θ _a in FIG. 4, and at this angle θ _b the current control switch 4 becomes conductive and the current I _1b begins to flow.
Therefore, the current I _1b flowing from the ignition power supply coil 3 through the switch reaches the set value at the angle θ ₁ earlier than the current I _1a when the diode 10 is not provided.
i _nio is reached, and the ignition operation becomes possible even at an angle θ ₁ that is further advanced than the angle θ ₁ ′. Therefore, in this case, the advance angle width is β (>α), and the advance angle characteristic becomes as shown by the broken line b in FIG.

In the above embodiment, the current control switch 4 may be controlled to conduct when one half cycle of the output of the ignition power supply coil 3 rises, and then to be shut off by a signal that determines the ignition position. , its configuration is arbitrary. Further, a cam-controlled interrupter may be used as the current control switch 4.

[Effects of the invention] As described above, according to the invention, the low-speed generator coil is connected in parallel to the low-speed generator coil whose output phase is delayed, and the output of the negative half cycle of the low-speed generator coil is short-circuited. Since a diode is provided to reduce the negative half-cycle output voltage of the low-speed generator coil, it is possible to advance the position at which the current flowing from the ignition power supply coil through the current control switch reaches the set value and widen the advance angle width. It has the advantage of being able to fully meet the needs of institutions.

[Brief explanation of the drawing]

Fig. 1 is a connection diagram showing an example of the configuration of an ignition device that has already been proposed, Fig. 2 is a schematic configuration diagram showing an example of a generator used in the ignition device and the ignition device of the present invention, and Fig. 3 is a connection diagram showing an example of the configuration of the ignition device of the present invention. A connection diagram showing an example of the invention,
Figures 4A and B are waveform diagrams showing the voltage and current of each part of the devices in Figures 1 and 3, and Figure 5 compares an example of the advance angle characteristics obtained by the devices in Figures 1 and 3. FIG. 1...Ignition coil, 2...Spark plug, 3...
Ignition power supply coil, 31a, 31b...Low speed generator coil, 32...High speed generator coil, 4...Current control switch, 10...Diode.

Claims (1)

[Claims for Utility Model Registration] An ignition power supply coil configured by connecting a high-speed power generation coil and a low-speed power generation coil in series, and an ignition power supply coil that is provided in parallel to the ignition power supply coil and is electrically connected at the ignition position of the internal combustion engine. a current control switch that is controlled from a state to a cutoff state, and an ignition coil that boosts a voltage induced in the ignition power supply coil when the current control switch is cut off, and the output voltage of the low speed generator coil is increased. The phase relationship between the high-speed power generation coil and the low-speed power generation coil is set such that a section where the output voltage of the high-speed power generation coil is in a negative half cycle overlaps a section where the output voltage of the high speed power generation coil is in a positive half cycle. , the ignition position is such that the positive half-cycle current flowing from the ignition power source coil through the current control switch is equal to or higher than the set position due to the positive half-cycle output of the high-speed generating coil and the low-speed generating coil. An ignition device for an internal combustion engine set in a section, comprising: a diode connected in parallel to the low-speed generating coil to short-circuit the output of the negative half cycle of the low-speed generating coil. Engine ignition system.