JPH01359A - engine ignition system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a self-trigger type engine ignition device using a transistor magneto type.

BACKGROUND ART In general, this type of engine ignition system is installed in a general-purpose small engine, and as shown in FIG. When the main transistor Tr1 is turned on, the switching is controlled according to the change in the voltage induced in the primary side P of a type of magnet generator with the primary side P of the ignition coil IOC as the armature. A low-voltage alternating current is passed through the primary circuit, and when it is turned off, the primary current is abruptly cut off to generate a high voltage on the secondary side S of the ignition coil IOC by electromagnetic induction, which causes a spark to fly to the spark plug G. It is configured. In addition, as a control circuit for the main transistor Tr in such an engine ignition system, as shown in the figure, the main transistor Tr whose collector and emitter are connected in series to the primary circuit of the ignition coil IOC is used.
In addition to connecting a resistor R between the base and collector of 1.

A control transistor Tr is connected in R-connection to the base side of the control transistor Tr2, and the base of the control transistor Tr2 is controlled by a voltage dividing resistor R2, R connected in parallel to the primary side of the ignition coil IOC. ing.

In the engine ignition system configured in this way, the rotor R
When the main transistor Tr rotates and an alternating voltage is induced on the primary side P of the ignition coil IOC, first, when the collector side of the main transistor Tr becomes positive, a position, the base current flows through the resistor R and its main Transistor Tr1 turns on, thereby causing a primary current to flow through the ignition coil IGC.Next, the collector-emitter voltage of main transistor Tr1 rises,
When the potential at point a divided by the resistor R2°R1 reaches the trigger level (set to about 0.6V) of the control transistor Tr2, the control transistor Tr2.

is turned on, which short-circuits the base side of the main transistor Tr1, turning it off, and the ignition coil IOC
The primary current of the spark plug G is abruptly cut off, and a high voltage pulse is induced in the secondary side S of the spark plug G, causing the spark plug G to emit a spark.

Conventionally, in such a transistor/magnet type engine ignition system, in order to provide it with an advance function, the magnet generator part is made of wax as shown in Fig. 9 (Japanese Patent Laid-Open No. 61-40463 (see publication).

That is, the permanent magnet MG is attached to the cutout part of the disc 2 made of a non-magnetic material with the polarity shown in the figure through the magnetic pole piece 1 so that the magnetic poles of the permanent magnet MG on the rotor R side become three poles. . In addition, so that the armature side has a two-pole structure, the ignition coil L0C (
A core 3 (with a secondary coil wound concentrically on the inside and a primary coil wound concentrically on the outside) is formed into a U-shape as shown in the figure, and both ends of the core 3 are wound with a predetermined gap between them. The rotor R is disposed so as to face the rotor R.

However, in such a device, as the rotor R rotates, the magnetic flux Φ passing through the core 3 changes as shown in FIG. A voltage with a wide range ■ is generated. Therefore, when turning on the control transistor Tr2 in the ignition control circuit shown in FIG. 2 using a negative voltage with a large peak voltage among the -next main voltage V,
The point in time when the potential at point a reaches the trigger level of control transistor Tr2 differs depending on the engine speed.

Figure 11 shows the ignition coil IOC according to the engine speed.
The characteristics of the primary oscillating voltage V are shown.

In the figure, when the engine speed is low, a voltage waveform V with a relatively slow change and a low peak voltage is obtained, which reaches the trigger level L at time t1, and the engine is ignited as described above. become. As the engine speed increases, as shown in the figure, a voltage waveform 2 with a relatively steep peak voltage and a high peak voltage is obtained. The engine is ignited when it reaches .

However, in such a conventional engine ignition system, by adopting a magnet generator structure as shown in Fig. 9, the primary ignition main voltage V at the ignition coil IOC is made to have a time width and advance angle adjustment is performed. Therefore, due to its structure, there is a limit to the advance angle adjustment range, and the range is relatively narrow.

In addition, in the conventional engine ignition system, its advance angle characteristic is 8th.
As shown in the figure, the only characteristic is that the ignition position changes gradually depending on the engine speed.

In this regard, when the engine speed rises above a certain level, an advance angle characteristic in which the ignition position changes in steps as shown in Fig. 7 may be required, but conventional engine ignition systems do not allow this. cannot meet such demands.

1. The present invention has been made in consideration of the above points, and uses a transistor magneto system that allows for a wide range of lead angle adjustment and also allows for stepwise changing lead angle characteristics. The present invention provides an engine ignition system based on the following.

1. In order to achieve the object, the present invention uses a rotor with magnetic poles around the periphery that rotates in synchronization with the engine as a field, and a generator with an armature as the primary side of the ignition coil as a power source. The switching transistor installed in the primary circuit is turned on and off according to the magnitude of the primary generated voltage of the ignition coil. Three magnetic pole parts are formed continuously in the rotational direction of the rotor, and the core is provided around the rotor with three leg parts facing each other through a predetermined gap,
The primary coil of the ignition coil is wound in sections so that voltages of different phases are induced by the rotation of the rotor,
The induced voltages of the respective primary coils are superimposed to obtain the primary generated voltage.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The engine ignition system according to the present invention employs a transistor magneto system as shown in FIG. 2, and its magnet generator portion is constructed as shown in FIG.

That is, a magnetic pole piece having magnetic pole parts 11 and 13 at both ends is fitted and bonded into a cutout part of a disc 2 made of a non-magnetic material so that the magnetic poles formed around the rotor R side have a three-pole structure. Attach a permanent magnet MG to the central part of 1 with the polarity shown in the figure, and attach the permanent magnet MG so that the magnetic pole part 12 at the center becomes the north pole and the magnetic pole parts 11 and 13 on both sides become the south pole.
The two magnetic pole portions 11, 12, and 13 are continuously provided in the rotational direction of the rotor R shown by the arrow in the figure.

Here, the permanent magnet MG is placed in a chamber formed in a concave shape in the center of the magnetic pole piece 1, and the upper part of the permanent magnet MG is inserted into the magnetic pole piece 12.
A permanent magnet M by being occluded by a lid forming a
G is attached to the magnetic pole piece 1.

Note that three magnetic pole pieces are provided on the disk 2 so that three magnetic pole parts are similarly formed around the rotor R without using any magnetic pole piece 1.
Two permanent magnets may be attached.

Further, a core 4 formed in a substantially E-shape having three leg portions 41, 42, 43, each end facing the rotor R through a predetermined gap, so that the armature side has a three-pole structure. is provided, and the primary coils 51 and 52 of the ignition coil IOC are separately wound around the legs 41 and 43 on both sides of the core 4, respectively. In reality, the leg portion 41 of the core 4 is wound with the secondary coil of the ignition coil IOC on the inside, and the primary coil 51 is wound concentrically on the outside (or vice versa). There is a primary coil 51 inside,
A secondary coil is wound around the outside of the coil.)

Further, each of the primary coils 51 and 52 receives a voltage V1. They are connected in series so that V2 is superimposed.

However, in a lever configured in this way, when the rotor R rotates in the direction shown by the arrow in the figure in synchronization with the rotation of the engine, each primary coil 51, 52 has a
As shown in the figure, magnetic fluxes Φ4. Φ2 passes through each and the voltage ■1□.

V x z is induced, and a superimposed one-water generation voltage V is obtained as shown in FIG. At this time, the number of turns of the other primary coil 52 is made larger than that of the one primary coil 51, so that the peak voltage of V□2 is larger than that of V□1.

In this case, instead of changing the number of turns of each primary coil 51, 52, the cross-sectional area of the core portion around which the primary coil 52 is wound may be made larger than that of the primary coil 51 side.

Therefore, when the engine speed is low, as shown in FIG. 6, a primary generator voltage V with a relatively gradual change and a low peak voltage is obtained, and this is applied to the ignition control circuit of the second motor at time t1. When the trigger level L of the control transistor Tr is reached, the engine is ignited as described above. As the engine speed increases, as shown in the figure, the primary generated voltage v has a relatively steep peak voltage.
2 is obtained, the angle is advanced, and at the time point 2, the control transistor Tr reaches the trigger level L, and the engine is ignited.

In this case, in the present invention, since the negative voltage waveform contributing to engine ignition at the primary generator main voltage V is set to have a valley, as shown in FIG. An advance characteristic is obtained in which the ignition position of the engine changes greatly in a stepwise manner due to minute changes in the engine speed at the boundary.

In this case, the spacing between the leg portions 41, 42° 43 in the core 4 and the spacing between the magnetic pole portions 11°, 12.13 on the rotor R may be changed as appropriate.

It becomes possible to adjust the ignition position of the engine and, in turn, adjust the advance angle width in steps.

In addition, as shown by the dotted line in FIG. 5, the spacing between the leg portions 41, 42, 43 in the core 4 and the magnetic pole portions 11, 12 in the rotor R are determined so that a valley does not occur in the superimposed one large generated voltage V'. By setting an interval of .13, it becomes possible to provide a characteristic in which the ignition position gradually changes in accordance with changes in the engine speed, as shown in FIG.

In this way, in the present invention, the two primary coils 51.
Since the primary generator voltage V is obtained by superimposing the two induced voltages V□□ and the V generator 2 with different phases, compared to the case where the primary generated voltage is obtained by one primary coil. This makes it possible to obtain a wide voltage waveform. Therefore, by triggering the control transistor Tr2 in the ignition control circuit of FIG. 2 by the primary main voltage V having the superimposed wide voltage waveform, the engine ignition control is performed. Significant advance angle characteristics can be obtained.

In addition, in this case, in particular, in the present invention, since the negative voltage with a large peak voltage of the primary generator main voltage V is used to control the ignition of the engine, highly responsive advance angle adjustment is possible. You will be able to do it more efficiently.

In the engine ignition system according to the present invention, the magnetic poles of the rotor in the magnet generator part have a three-pole structure, and the core on the armature side also has a three-pole structure. The structure is such that the primary coils are wound separately at different locations, and the induced voltages of each primary coil with different phases are superimposed to obtain the primary generated voltage. The width of the voltage waveform becomes larger, making it possible to cover a wider range, and the ignition position changes in steps according to the engine speed, making it easy to realize advance angle characteristics. It has advantages.

[Brief explanation of drawings]

Fig. 1 is a simplified configuration diagram showing an example of the configuration of the magnet generator part in the engine ignition system of the present invention, Fig. 2 is an electric circuit diagram showing an engine ignition system using a general transistor magneto type, and Figs. Fig. 4 is a characteristic diagram showing the magnetic flux waveform and induced voltage waveform of the two primary coils in the configuration shown in Fig. 1, and Fig. 5 shows the waveform of the primary generated voltage obtained by superimposing the induced voltages of the two primary coils. Characteristic diagram, 6th
The figure is a characteristic diagram showing how the primary generated voltage changes depending on the engine speed, Figures 7 and 8 are diagrams each showing an example of advance angle characteristics, and Figure 9 is a simplified configuration of the conventional magnet generator part. 10 are characteristic diagrams showing the magnetic flux waveform and induced voltage waveform of the primary coil. FIG. 11 is a characteristic diagram showing how the primary generated voltage changes depending on the engine speed in the engine ignition system having the magnet generator structure shown in FIG. 1...Magnetic pole piece 2...Disk 3, 4...Core 5
1゜52...Primary coil R...Rotor IGC・
・Ignition coil

Claims (1)

[Claims] A rotor with magnetic poles around the periphery that rotates in synchronization with the engine is used as a field, and a generator with the primary side of the ignition coil as an armature is used as a power source.The switching transistor installed in the primary circuit of the ignition coil is In a device that turns on and off according to the magnitude of the primary generated voltage of the ignition coil, the three magnetic pole parts are arranged in the rotational direction of the rotor so that the central part has different poles and the opposite poles have the same pole. The core is continuously formed and provided around the rotor with three legs facing each other through a predetermined gap, so that voltages of different phases are induced by the rotation of the rotor. An engine ignition device characterized in that a primary coil of an ignition coil is wound in sections and the induced voltages of the respective primary coils are superimposed to obtain the primary generated voltage.