JPH0676789B2 - Ignition device for internal heat engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ignition device for an internal combustion engine used in an internal combustion engine of an automobile or the like.

[Conventional technology]

BACKGROUND ART Engines used in automobiles often include internal combustion engines that generate power by burning fuel inside the engine. Among them, in a gasoline engine that uses gasoline as fuel, the compressed gas is ignited by a high-voltage discharge spark in the cylinder, and combustion is performed. The high voltage uses a storage battery as a power source. The most basic engine system is shown in FIG. A current of 6 to 12 volts from the storage battery is made to flow through the primary winding of the ignition coil in the ignition circuit 14 to generate a magnetic field, and the current in the primary winding is rapidly cut off by the interrupter 19 (circuit breaker). Then, due to the electromagnetic induction action, 15000 to 20000 on the secondary winding side.
Generates a high voltage of Volt. This high voltage is distributed by a distributor (distributor) 15 and is passed through a high voltage cable 17 to a spark plug attached to each cylinder.
Power is supplied to 16 to discharge sparks between the electrodes of the spark plug to ignite the compressed mixed gas (mixed gas of gasoline mist and air) in the engine cylinder to drive the engine.

As the elements for driving the above engine system most efficiently, (1) the mixing ratio of the mixed gas.

(2) Compression ratio of mixed gas.

(3) Ignition voltage and ignition timing.

Can be given.

In recent years, there have been many ideas for improving the above elements from the viewpoint of improving engine performance. In particular, regarding the ignition system, the semitransistor system shown in FIG. 3 is used for the purpose of reducing the current flowing through the point part of the circuit breaker, preventing burnout of the point part, and generating a stable secondary high voltage. is there. The fourth application of Japanese Patent Application No. 57-76777
As shown in the figure, there is a full-transistor ignition system in which the ignition timing is controlled by detecting the engine crank angle by a combination of a non-contact type magnet and a pick-up coil 3 at the point portion. FIG. 5 shows the structure of a contactless igniter. There is a reluctor 1 having four blades in a shaft 5 that rotates in conjunction with the engine crank (in the case of a 4-cylinder engine, it has 4 blades and in the case of a 6-cylinder blade) a stator 2 is provided in the vicinity of the protrusions of the blades. A permanent magnet 6 is incorporated in the lower portion of the stator 2. Therefore, the permanent magnet 6,
A magnetic circuit 7 including a stator 2, a reluctor 1, and a shaft 5 is formed. The pick-up coil 3 is provided in the area of the magnetic circuit 7. Specifically, a solenoid coil having the shaft 5 as an axis is used.

When the reluctor 1 rotates, the gap between the reluctor 1 and the stator 2 changes at the blades and valleys, which appears as a change in magnetic flux density. Therefore, an alternating voltage corresponding to the change in magnetic flux density is induced in the pick-up coil 3.

[Problems to be solved by the invention]

As described above, for the purpose of high-performance engine orientation, the conventional mechanical element method is shifting to the electronic control method. However, since the engine room is filled with a lot of electromagnetic noise generated from the high voltage system, the generator, the starter, etc., electromagnetic noise is newly mixed in the electronic control circuit,
There is a problem that causes engine malfunction. As one of the problems, there is a problem that the engine lock is caused by the noise accompanying the starter ON / OFF that is operated when starting the engine. The cause will be described with reference to FIG. The engine is started by mechanically rotating the engine crankshaft with external force. The starter provides this rotational force and requires a strong torque, so that it is equipped with a high-power electric motor. Normally, a current of about 400A flows when the starter is NO. Therefore, electromagnetic noise due to magnetic induction is generated around the starter cable.
In the non-contact type igniter, there is a pickup coil 3 sensitive to magnetism. The pickup coil 3 is a coil originally provided for the purpose of detecting an ignition timing signal, but for some reason, noise is generated in the pickup coil 3. May invade.

The condition of whether or not noise enters the coil in the electromagnetic noise environment is complicated, and it may be influenced by the characteristics (frequency, directivity, etc.) of the detection side. It changes with (static electricity, radio wave static electricity, etc.). In any case, the noise intrusion frequency is probabilistic, and there is a possibility that noise will sufficiently intrude into the sensor in the noise environment.

The noise signal component that has entered the pickup coil 3 is combined with the normal ignition timing signal, and the signal discrimination circuit 12 judges all signals as ignition signals and sends them to the amplification circuit 13, the ignition circuit 14, and the distributor 15, and the ignition plug 1
At 6, the misfire of the noise component occurs in addition to the normal timing ignition.

Since the entire igniter is covered with an aluminum die cast housing, the electromagnetic wave shielding effect is effective, but judging from the fact that noise trouble actually occurs, it seems that the noise inside the igniter is invading. .

As described above, the entire igniter 10 is covered with the metal housing 8 such as aluminum die cast,
Although some measures have been taken to prevent electromagnetic noise from entering, electromagnetic noise may be introduced from the shafts that penetrate and the gaps in the rotating parts. As shown in the conventional column in FIG. 9, let us consider a case where a change in the starter current causes electromagnetic noise to enter the igniter 10 in the conventional system.

The electromagnetic noise appears as a voltage change in the pick-up coil and detects a signal having the waveform shown in the figure. When this signal enters the signal discrimination circuit, the signal level existing within the reference value is extracted and a rectangular wave as shown in the figure is output. In this signal, noise components are mixed in addition to the normal ignition signal, but they are all sent to the power transistor circuit 13 and are output to the secondary voltage of the ignition coil 13 outside the normal ignition signal. An erroneous ignition signal is also generated due to the noise component. If ignition occurs in the engine cylinder at a timing other than the ignition timing, misfire may occur and the engine may malfunction. In some cases, engine lock will occur.

As a measure against noise, it is known from JP-A-57-68561 that uses a bandpass filter such as an L, c resonance circuit or the like, but these filters are effective against specific frequency noise. However, in a place such as an automobile where the frequency of noise cannot be specified, it is necessary to remove a noise component in a wide frequency band, so that the known method has a problem that its effect is not sufficient.

An object of the present invention is to provide an ignition device for an internal combustion engine that can remove noise that has entered the pickup coil and the signal transmission line and that prevents erroneous ignition due to noise.

[Means for Solving the Problems] A feature of the present invention that achieves the above object is that a pickup that detects a change in magnetic flux in a closed-circuit magnetic circuit including a stator and a reluctor through which magnetic field lines pass and outputs a voltage signal. A coil, a compensation coil provided outside the magnetic circuit for detecting a change in magnetic flux in the reluctor and outputting a voltage signal, and a signal indicating a difference between the output signal of the pickup coil and the output signal of the compensation coil. The first signal transmission line connected to the pickup coil and the second signal transmission line connected to the compensation coil are connected to the compensation unit by coaxial wiring or twisted wiring.

[Operation] The pickup coil outputs a voltage signal corresponding to the change in the magnetic flux in the magnetic circuit caused by the rotation of the reluctor. However, when noise enters the pickup coil via the reluctor, the output signal of the pickup coil contains the noise component. The change in the magnetic flux inside the reluctor due to the noise is detected by the compensation coil provided outside the magnetic circuit. Since the compensation means outputs a signal indicating the difference between the output signal of the pickup coil and the output signal of the compensation coil, the noise component contained in the output signal of the pickup coil is removed. Therefore, the compensating means outputs a signal corresponding to the change of the magnetic flux generated by the rotation of the reluctor, so that erroneous ignition due to noise entering the pickup coil can be avoided. Also, the first
Since the second signal transmission line and the second signal transmission line are coaxial wirings or wirings twisted with each other, the first signal transmission line and the second signal transmission line are located close to each other. Therefore, when noise invades the signal transmission line from the outside, the noise invading the first and second signal transmission lines becomes the same and can be removed by the compensating means. Therefore, even if noise enters the signal transmission line, erroneous ignition of the internal combustion engine due to the noise can be avoided.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 7 to 10. FIG. 1 shows a block diagram of the ignition system of the present invention. As shown in FIG. 7, an igniter 10 composed of a reluctor 1 fixed to a rotary shaft 1, a stator 2 supported by a housing 8, a pick-up coil 3, a compensation coil 4 and the like.
The compensating circuit 11, the signal discriminating circuit 12, the power transistor circuit 13, the ignition circuit 14, the distributor 15, the spark plug 16 and the like in FIG. Figure 7 shows
A specific structure within the igniter 10 implemented in the present invention is shown. FIG. 8 is a sectional view taken along the line II-II in FIG. 7 and shows the positional relationship between the reluctor 1 and the stator 2.

The reluctor 1 has a number of blades corresponding to the number of cylinders of the engine, and a stator 2 having two claws at a position of 180 degrees on the blades.
Are provided close to each other. A permanent magnet 6 is provided at the seat of the stator 2, and a magnetic circuit 7 is formed by the shaft 5, the reluctor 1 and the stator 2. The components such as the shaft 5, the reluctor 1, and the stator 2 that form the magnetic circuit 7 in a closed circuit are made of a magnetic material such as iron. A pick-up coil 3 is provided on the outer periphery of the shaft 5 in the inner area of the magnetic circuit 7. The compensation coil 4 is provided outside the area of the magnetic circuit 7 and on the outer periphery of the shaft 5 coaxial with the pickup coil 3. These are installed by being supported from the housing 8 in the housing 8 made of aluminum die cast. The shaft 5 penetrating the housing 8 has a structure in which the lower part is connected to the engine crank and the upper part is connected to the distributor so as to rotate.

A concrete circuit configuration diagram of the compensation circuit 11 is as shown in FIG.
2 is a concrete circuit configuration diagram of the compensation circuit 11 of FIG.

The compensation circuit 11 is composed of a pick-up coil operational amplifier 20, a compensation coil operational amplifier 21, and a differential amplifier 22.

The pick-up coil signal 23 is input to the operational amplifier 20, and the compensation coil signal 24 is input to the operational amplifier 21, and the amplification factors of the operational amplifiers 20 and 21 are adjusted so that the signal strengths of both signals become the same level. Both matched signals are input to the differential amplifier 22. The differential amplifier 22 handles the signal as the difference between the two signals, amplifies the signal, and then outputs the ignition signal 25.

Therefore, when the pickup coil signal 23 and the compensation coil signal 24 containing noise are input, the compensation circuit 11 subtracts the compensation coil 24 from the pickup coil signal 23, so that the compensation coil 11 enters the pickup coil 3 through the reluctor to a wide frequency range. Removes noise from the normal ignition signal
It can output 25.

The operation of this embodiment will be described below with reference to the drawings. FIG. 9 shows signal waveforms at each stage of the ignition system. First, the case of normal operation will be described.

When starting the engine, turn on the starter key, and when the engine starts, turn off the starter key. The starter forcibly rotates the engine crank and is driven by a high-power electric motor. When the engine crank rotates, the shaft 5 of the igniter 10 also rotates together. In the case of a 4-cylinder, 4-cycle (intake, compression, explosion, exhaust) engine, the shaft 5 of the igniter 10 makes one revolution while the engine crank makes two revolutions (two piston reciprocations). At this time, a starter current waveform as shown in FIG. 9 flows through the starter cable. Under normal conditions, this starter current has no effect on the outside. On the other hand, the reluctor 1 that rotates in conjunction with the shaft 5 appears as a change in the magnetic flux of the magnetic circuit 7 due to the rotation of the blade portion, and an alternating voltage is induced in the pick-up coil 3. Input the alternating voltage to the signal discriminating circuit, compare and discriminate against the negative reference voltage of the alternating voltage wave, rectangular waveform (pulse shape)
Generates the ignition signal of. The power transistor circuit 13 is
This ignition signal is amplified and power is supplied to the primary side of the ignition coil in the ignition circuit 14 based on the ignition signal. On the secondary side of the ignition coil, a negative pulse voltage is generated at the falling edge of the primary side rectangular wave. The high voltage is guided to the distributor 15 by a high voltage cable 17. The distributor 15 distributes electricity to each spark plug 16 by the rotation of the shaft 5 coaxial with the reluctor 1 described above. The spark plug 16 ignites in a predetermined ignition order of each engine cylinder. The above is an example of the operation when normal, but next, an example of the operation when noise occurs will be described.

The electromagnetic noise in the engine room is due to the starter ON, O
There are various types other than those that occur during FF, and they are distributed in a complicated manner, and the characteristics (frequency, waveform, level) and directionality (directivity) of intrusion noise are not fixed. In this embodiment, as shown in FIG. 7, since the compensation coil 4 is arranged coaxially with the pickup coil 3, the same noise component of the electromagnetic wave noise that is distributed in a complicated manner is distributed to both coils 3 and 4. invade. Therefore, the noise component detected by the compensation coil 4 shown in FIG. 9 is also included in the output signal of the pickup coil 3. The compensation circuit 11 inputs both output signals of the pickup coil 3 and the compensation coil 4. The compensation circuit 11 subtracts the output signal of the compensation coil 4 from the output signal of the pickup coil 3 and outputs a signal from which noise components have been removed. The signal discrimination circuit 12 outputs the ignition signal equivalent to that during normal operation by inputting the output signal of the compensation circuit 11. Therefore, this embodiment can prevent erroneous ignition at the ignition plug when noise enters the pickup coil 3.

Although the case where the noise is generated at the start-up of the starter has been described above, the present embodiment can remove the noise other than the noise generated at the start-up of the starter coil 3 by the compensation circuit 11.

Next, a case where noise enters the portion other than the pickup coil 3, for example, the lead wire portion of the pickup coil 3, will be examined. In the present embodiment, the lead wire of the pickup coil 3 and the lead wire of the compensation coil 4 are coaxial wiring or twisted wiring with each other.
Since the lead wires are arranged close to each other, it can be said that they are in the same noise environment field. Therefore, when noise enters the lead wires from the outside, the same noise enters the lead wires. The noise that has entered each lead wire is input to the compensation circuit 11 together with the output signal of each coil, and is subtracted from each other in the compensation circuit 11 to be removed. Therefore, in the present embodiment, even when noise enters the lead wires connected to the pickup coil 3 and the compensation coil 4, it is possible to obtain the same ignition signal as in normal operation and prevent erroneous ignition of the ignition plug. it can.

According to the present invention, since the pickup coil and the compensating coil are connected to the compensating means, it is possible to remove the noise from the output signal of the pickup coil when the noise enters the pickup coil. Accidental ignition can be prevented. Further, even when noise enters the first and second signal transmission lines, the noise can be removed by the compensating means, so that misfire can be avoided.

[Brief description of drawings]

FIG. 1 is a block diagram of an ignition system for an internal combustion engine of the present invention, FIG. 2 is a perspective view of a basic engine system, FIG. 3 is a conventional semitransistor type ignition system circuit diagram, and FIG. Full transistor type ignition system circuit diagram, FIG. 5 is a longitudinal sectional view of a structure of a conventional non-contact igniter, FIG. 6 is a block diagram of an ignition system of a conventional internal combustion engine, and FIG. 7 is a longitudinal sectional view of an igniter of the present invention. FIG. 8 is a plan view, and FIG. 8 is a view taken along the line II of FIG.
FIG. 9 is an ignition signal processing waveform diagram of the present invention and a conventional one, and FIG. 10 is a circuit diagram of the compensation circuit in FIG. 1 ... Reactor, 2 ... Stator, 3 ... Pickup coil, 4 ... Compensation coil, 5 ... Shaft, 6 ... Magnet, 7 ... Magnetic circuit, 8 ... Housing, 10 ... Igniter, 11 ... … Compensation circuit, 12 …… Signal discrimination circuit, 13 …… Power transistor circuit, 14 …… Ignition circuit,
15 …… Distributor, 16 …… Spark plug.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shin Onizawa 1168 Moriyama-cho, Hitachi City, Ibaraki Pref., Energy Research Institute, Inc. Energy Research Laboratory (72) Inventor Hideyuki Hashimoto 2520 Takaba, Katsuta City, Ibaraki Prefecture Sawa Factory, Hitachi, Ltd. (56) , Y1)

Claims (1)

[Claims] 1. A reluctor attached to a rotating shaft, a stator arranged with a gap from the reluctor, a closed circuit magnetic circuit including the reluctor and the stator through which magnetic field lines pass, and a magnetic flux in the magnetic circuit. A pickup coil that detects a change and outputs a voltage signal, a compensation coil that is provided outside the magnetic circuit and that detects a change in magnetic flux in the reluctor to output a voltage signal, an output signal of the pickup coil and the Compensating means for outputting a signal indicating the difference from the output signal of the compensating coil, means for periodically outputting a pulsed ignition signal based on the output signal of the compensating means, and a secondary side according to the ignition signal. Ignition means for generating a voltage higher than the voltage of the primary coil in the coil, and the voltage generated in the secondary coil attached to the rotary shaft. A first signal transmission line connecting the pickup coil and the compensating means, and a second signal transmission line connecting the compensating coil and the compensating means, coaxial wiring or twisted together. An ignition device for an internal combustion engine, characterized in that the wiring is different.