JPS6130150B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an internal combustion engine ignition system, and particularly to an internal combustion engine ignition system that increases the SN ratio of an ignition signal in a non-contact type ignition system.

[Conventional technology]

Conventionally, there have been devices of this type as shown in FIGS. 1 to 3. In the figure, 1 is a rotating shaft driven by an internal combustion engine (not shown), and 2 is this rotating shaft 1.
The rotor is attached to the rotor and is formed as shown in FIG. A stator 3 faces the rotor 2 with an air gap as shown in FIG. 2, and is assembled integrally with a permanent magnet 4 and a magnetically conductive plate 5.
It is supported by a housing 6. Reference numeral 7 denotes a signal coil that generates an ignition signal in response to changes in magnetic flux caused by the rotation of the rotor.

Next, the operation of such a conventional device will be explained. The magnetic flux ΦΣ shown in FIG. 4a caused by the permanent magnet 4 passes through a magnetic path formed by the stator 3, rotor 2, rotating shaft 1, and magnetically conductive plate 5, and is wound around the rotor 2 and rotating shaft 1. It interlinks with the signal coil 7.

As the rotor 2 rotates together with the rotating shaft 1, the opposing magnetic pole portions 2 provided on the rotor 2 and the stator 3
The magnetic flux ΦΣ changes depending on the relative positional relationship between a and 3a, and in response to this change, an ignition signal shown in FIG. 4b is generated in the signal coil 7.

Since this type of conventional device is constructed as described above, as shown in FIGS. 1 and 4, the magnetic flux Φ generated by the permanent magnet 4 and effective for causing the signal coil 7 to generate a predetermined ignition signal ₁ , a magnetic flux Φ ₂ which is also generated by the permanent magnet 4 but is disadvantageous to the generation of the signal, and a disturbance magnetic flux Φ ₃ generated by a generator, electric motor, primary lead wire of an ignition coil, etc. (not shown). Linked to signal coil 7. Such an ignition system includes an ignition timing advance device (not shown), etc.
Since steel is used in the vicinity of the ignition signal generation part, the relative ratio of the unfavorable magnetic flux Φ ₂ to the effective magnetic flux Φ ₁ among the magnetic flux generated by the permanent magnet 4 is large, so that the predetermined ignition signal output cannot be achieved. There were drawbacks that were difficult to obtain. In addition, as an example of Φ ₃ shown in Fig. 4, there is a case where the rotating shaft 1 picks up magnetic flux due to magnetic disturbance caused by the starting current of the starting motor, and this has the disadvantage that the ignition system malfunctions due to the disturbance of the ignition signal. Ta.

To improve these drawbacks, for example, there is a method described in Japanese Utility Model Application Publication No. 141434/1983. The device described in this Japanese Utility Model Publication No. 53-141434 connects another signal coil in series with the original signal coil with the winding direction reversed, and the other signal coil is used to generate ignition signals such as disturbance magnetic flux. It is constructed to cancel out noise signals generated by unfavorable magnetic flux.

[Problem that the invention seeks to solve]

By the way, what is shown in Utility Model Application Publication No. 53-141434 is a system in which a signal coil for generating an ignition signal is connected in series with another signal coil that interlinks with unfavorable magnetic flux such as the disturbance magnetic flux mentioned above. This method is characterized by canceling out signals caused by unfavorable magnetic flux such as disturbance magnetic flux, and can prevent malfunctions due to unfavorable magnetic flux such as any disturbance magnetic flux mentioned above, but on the other hand, it requires two signal coils, and Since these electrical connections are required, the device is complicated and expensive. Furthermore, when there is a disturbance magnetic flux, the voltage generated in the coil effectively cancels out the change due to the disturbance magnetic flux, but when there is no disturbance magnetic flux, the regular signal coil output decreases by the amount of the other signal coil. There is.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and by simply providing an independent short-circuit coil that does not require any connection with the signal coil, it cancels the noise signal caused by the disturbance magnetic flux and ignites. An internal combustion engine ignition system that can increase the signal S/N ratio and does not have the problem of reducing the normal output when there is no disadvantageous magnetic flux such as disturbance magnetic flux, as in the above-mentioned Utility Model Application Publication No. 53-141434. The purpose is to obtain.

[Means for solving problems]

An internal combustion engine ignition device according to the present invention includes a rotating shaft that is driven and rotated by an internal combustion engine, a rotor attached to the rotating shaft, and a stator that is disposed opposite to the rotor with a gap therebetween. In the magnetic circuit,
A signal coil is arranged to generate an ignition signal in response to changes in magnetic flux due to rotation of the rotor, and a short-circuit coil is provided independently of the ignition signal coil so as to surround the rotation axis, and furthermore, this short-circuit coil is connected to the above-mentioned The signal coil is placed in such a position that it does not interlink with magnetic flux that is effective for generating a predetermined ignition signal, but on the contrary, it interlinks with magnetic flux that is disadvantageous for generating an ignition signal.

[Effect]

In this invention, the short-circuit coil is provided independently of the ignition signal, and the signal coil is arranged so as not to interlink with the magnetic flux effective for generating a predetermined ignition signal, so that ignition signals such as disturbance magnetic flux are generated. If there is no unfavorable magnetic flux, the normal signal coil output can be fully demonstrated, and
Because the short-circuit coil is arranged so as to interlink with the magnetic flux that is unfavorable to generating the ignition signal, unfavorable magnetic flux such as disturbance magnetic flux is generated, and even if this magnetic flux tries to cause the ignition signal to become intertwined, the short-circuit coil will not ignite the ignition signal. The short-circuit current induced by the magnetic flux unfavorable to signal generation produces a magnetic flux in the opposite direction to the unfavorable magnetic flux, thereby suppressing the influence of the unfavorable magnetic flux to generate the ignition signal.

〔Example〕

An embodiment of the present invention will be described below.
In FIG. 5, the rotating shaft 1, rotor 2, stator 3, permanent magnet 4, magnetically conductive plate 5, casing 6, and signal coil 7 have the same configuration as the conventional device shown in FIG. 8 is a short circuit coil, which is connected to the stator 3 above.
and is provided surrounding the rotating shaft 1 at a position that is not included in the magnetic circuit composed of the rotor 2, a part of the rotating shaft 1, and the magnetically conductive plate 5. .

Next, the operation will be explained. When the rotor 2 rotates as the rotating shaft 1 rotates, the magnetic flux generated in the permanent magnet 4 changes depending on the relative positional relationship between the rotor 2 and the stator 3. First, the effective magnetic flux Φ ₁ for generating a predetermined ignition signal from the signal coil 7 is shown in Fig. 6a.
Changes as shown in . Next, since the magnetomotive force of the permanent magnet 4 is constant and finite, the magnetic flux Φ ₂ which is disadvantageous for generating a predetermined ignition signal is affected by the effective magnetic flux Φ ₁ as shown in Figure 6a. Change as shown. This unfavorable magnetic flux Φ ₂ interlinks with the short-circuit coil 8, as shown in FIG. 5, and causes a short-circuit current i ₁ in the short-circuit coil 8, as shown in FIG. 6b. Since this current i ₁ flows around the rotating shaft 1, a magnetic flux Φ ₁₁ in the opposite direction to the magnetic flux Φ ₂ is induced in the rotating shaft 1 as shown in FIG. 6b. This magnetic flux Φ ₁₁ does not occur in the conventional device, and can be considered by providing the short-circuit coil 8 in the device of the present invention, and this new magnetic flux Φ ₁₁ is required to generate the above-mentioned ignition signal. Since it acts in addition to the effective magnetic flux Φ ₁ , the change in the magnetic flux that causes the signal coil 7 to generate an ignition signal is due to the addition of the magnetic flux Φ ₁₁ to ΦΣ in Figure 6a, as shown in Figure 6a. It is increased as shown in ₁₁ . Therefore, the ignition signal output also increases.

Next, when the disturbance magnetic flux Φ ₃ is induced in the rotating shaft as shown in Fig. 7a, the ignition signal generated in the signal coil 7 will generally be disturbed as shown in Fig. 7b. However, in the device of the present invention equipped with the short-circuit coil ₈ , a short-circuit current _{i 3} as shown in _FIG . In order to cause
In the end, even if a disturbance magnetic flux is received by the action of the short-circuit coil 8, the influence on the magnetic flux ΦΣ shown in FIG. 7a is suppressed,
Disturbances in the ignition signal are also suppressed to a level that does not cause malfunction of the ignition device.

In order to facilitate understanding of the above description, FIG. 8 shows the relationship between the ignition signal and the opening/closing control of the primary circuit of the ignition coil in the embodiment device. That is, a positive minute voltage _e1 of the ignition signal is detected from L to H, the primary circuit of the ignition coil is closed and energized, and a positive minute voltage _e2 lower than the ignition signal _e1 is detected from H to L. The circuit is opened to generate a high voltage for ignition in the secondary circuit of the ignition coil.
The malfunction explained above is, for example, the disturbance magnetic flux Φ ₃
This means that when a disturbance in the ignition signal occurs, the minute voltages e ₁ and e ₂ that are not based on the predetermined ignition signal are detected and an ignition spark is generated at a time other than the normal ignition timing.

In the above embodiment, the short circuit coil 8 is replaced by the signal coil 7.
In contrast, although one unit is installed on one rotation axis, the operation and effect will be the same if the unit is installed on the other side, or both sides, or multiple units are installed. It is.

Furthermore, although the short-circuit coil 8 has been described as an example of a one-turn coil, various winding shapes can be considered, such as a coil with multiple turns short-circuited at both ends, or a washer-like or sleeve-like one made of a copper plate, for example. However, in order to obtain the effects of the present invention, the present invention is not limited to any one of them.

〔Effect of the invention〕

As described above, the present invention provides a short circuit coil independent of the ignition signal coil so as to surround the rotating shaft, and this short circuit coil is connected to the signal coil.
Since it is installed in a position where it does not interlink with the magnetic flux that is effective for generating a predetermined ignition signal, but on the contrary, it interlinks with a magnetic flux that is disadvantageous, it is possible to prevent magnetic flux that is disadvantageous in generating an ignition signal, such as disturbance magnetic flux. Disturbances in the ignition signal can be suppressed, and if there is no magnetic flux such as disturbance magnetic flux that is disadvantageous to the generation of the ignition signal, the normal signal coil output can be sufficiently exerted.

Furthermore, since the short-circuiting coil is provided independently of the ignition signal coil, which is a simple structure, an inexpensive device with high reliability can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional internal combustion engine ignition system, Fig. 2 is a partial plan view of the ignition system shown in Fig. 1, and Fig. 3 is a perspective view of the ignition signal rotor shown in Fig. 1; 4 is a magnetic flux change and ignition signal waveform diagram of the ignition device shown in FIG. 1, FIG. 5 is a sectional view showing an embodiment of the internal combustion engine ignition device according to the present invention, and FIG. 6 is a diagram of the ignition device shown in FIG. 5. Fig. 7 shows the influence of disturbance magnetic flux on the ignition device shown in Fig. 5. Fig. 8 shows the ignition signal and the primary circuit of the ignition coil. It is an explanatory diagram of the relationship between opening and closing. In the figure, 1...Rotating shaft, 2...Rotor, 3
...Stator, 4...Permanent magnet, 6...Casing, 7...
...Signal coil, 8...Short-circuit coil. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1 A rotating shaft driven by an internal combustion engine and supported by a housing, a rotor attached to this rotating shaft,
A stator that faces the rotor with an air gap and is supported on the housing side, a magnet that provides magnetic flux to a magnetic circuit that includes the stator, the rotor, and a part of the rotating shaft; A signal coil that generates an ignition signal in response to changes in magnetic flux due to rotation of the rotor, and a short-circuit coil that is provided independently of the signal coil so as to surround the rotation axis, and the short-circuit coil is connected to the For the signal coil,
An internal combustion engine ignition device characterized in that it is provided at a position such that it does not interlink with magnetic flux that is effective in generating a predetermined ignition signal, but conversely interlinks with magnetic flux that is disadvantageous in generating an ignition signal.