JPH0327760B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an internal combustion engine ignition system, and more particularly to an internal combustion engine ignition system that prevents the generation of ignition sparks when the engine is reversed.

[Conventional technology]

A conventional device of this type is shown in FIG. In the figure, 1 is a rotor driven in the direction of arrow 2 by an engine (not shown), and has a predetermined protrusion between AB. 3 is a pick-up which is installed facing the rotor 1 and is a first sensor for detecting the first and second crank angle positions of the engine, and as shown in FIG. When the rear end B of the protrusion passes through the pick-up 3, it outputs a positive voltage as a first angle signal, and when the rear end B of the protrusion passes through the pick-up 3, it outputs a negative voltage as a second angle signal. Reference numerals 4 and 5 denote first and second diodes, which are connected to the coil of the pickup 3 and function to discriminate between the positive and negative voltages mentioned above. That is, the anode of the first diode 4 is connected to the coil end of the pickup 3, and its cathode is connected to the set input terminal of the flip-flop 6. second diode 5
Its cathode is connected to the coil end of the pick-up 3, and its anode is connected to the flip-flop 6.
connected to the reset input terminal. Therefore, the positive wave of the output voltage of the pickup 3 passes through the first diode 4 and enters the set input terminal of the flip-flop 6, setting the flip-flop 6 in the set state, and the negative wave passes through the second diode 4 and enters the set input terminal of the flip-flop 6. It passes through diode 5 and enters the reset input terminal of flip-flop 6, putting flip-flop 6 in the reset state. 7 is a transistor, which is used as a grounded emitter.

The base terminal of this transistor 7 is connected to the Q output terminal of the flip-flop 6, and the collector terminal is connected to the Q output terminal of the flip-flop 6.
They are connected to the primary windings of the ignition coil 8, respectively. The other end of the primary winding of the ignition coil 8 is connected to a key switch 9.
After that, it reaches Batsuteri 10.

Further, the secondary high voltage line of the ignition coil 8 is connected to the ignition plug 11.

FIG. 8 is an operation waveform diagram for explaining the operation of the one shown in FIG. 6, where a is the output voltage of the pickup 3, b is the set input voltage of the flip-flop 6,
c is the reset input voltage of flip-flop 6, d
is the Q output voltage of the flip-flop 6, e is the primary current of the ignition coil 8, and f is the waveform of the secondary voltage of the ignition coil 8.

Next, the operation will be explained. As the rotor 1 rotates, when the A end of the protrusion faces the pick-up 3, a positive voltage is generated in the pick-up coil, which passes through the first diode 4 and sets the flip-flop 6, resulting in its Q output. The terminal becomes high level (hereinafter abbreviated as "1"). Since the transistor 7 is turned on in response to the "1" signal at the Q terminal, the primary current of the ignition coil 8 begins to flow from this point on. As the rotor 1 continues to rotate further, the B end of the projection eventually faces the pickup 3. Here, a negative voltage is generated in the pickup coil, which resets the flip-flop 6 through the second diode 5, so that its Q output terminal becomes a low level (hereinafter abbreviated as "0"). Transistor 7 receives the “0” signal from the Q terminal.
is turned off, the primary current of the ignition coil 8 is cut off, and at that point a high voltage is generated on the secondary side of the ignition coil 8, and an ignition spark is produced at the ignition plug 11. 8th below
As shown in the figure, ignition sparks are periodically obtained as the rotor 1 rotates. There is nothing wrong with the above explanation, but when the engine starts, it differs greatly from when it is running normally, such as when the engine's rotational fluctuations are large or when it cannot overcome the reaction torque of the engine and reverses. Due to the conditions, the following problems occurred.

For example, the A end of rotor 1 is
Assume that the B end is configured to detect BTDC5°. (For example, BTDC5° indicates the initial ignition timing, and BTDC35° indicates the calculation start time of the electronic advance type ignition timing calculation circuit, both of which can be said to be highly general values). Assume that the rotor 1 is in the position shown in Fig. 6 before starting, and that the starting operation is started from there.
First, an external force such as a starter motor (not shown) is applied, and the rotor 1 gradually begins to rotate in the direction of arrow 2 (hereinafter referred to as a positive direction or normal rotation), and when the A end faces the pickup 3. At the same time, a positive voltage is generated in the pickup coil and the flip-flop 6 is set, so that the primary current of the ignition coil 8 begins to flow. After that, if the engine continues to rotate forward, it will move further towards compression top dead center.
As the reaction torque increases, under adverse conditions such as high battery or low outside temperature, the engine may not be able to overcome compression top dead center and may reverse midway through. In other cases, the starting operation may be stopped (the starter switch is turned off) before the engine starts, and in this case, the driving force of the engine will be zero, so the reverse rotation due to countershaft torque may occur. becomes even more miserly.
Regardless of the factor, the rotor 1, which has been able to rotate forward to around 15 degrees BTDC, begins to rotate in reverse at that point. The change in the magnetic field when the A end passes through the pick-up 3 in reverse rotation is the same as when the B end passes through the pick-up 3 in the forward rotation.
The voltage generated in the search coil when the A terminal passes through the pickup 3 in reverse rotation is a negative voltage. Therefore, upon receiving this negative voltage, the flip-flop 6 is reset, and the primary current of the ignition coil 8 is immediately cut off, so that an ignition spark is emitted at this timing. In other words, in terms of engine angle, the ignition spark occurs at 35 degrees BTDC, so this adds further reverse torque to the engine, which was already rotating in reverse when it ignited.
(Please also refer to Fig. 9, which shows the operating waveform diagram at the time of the above-mentioned malfunction.) Therefore, this encouraged the engine to reverse rotation, which could even lead to the destruction of the engine.

[Problem that the invention seeks to solve]

Since the conventional device is constructed as described above, it has had problems such as generating ignition sparks when the engine is reversed, destroying the engine.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an internal combustion engine ignition system that does not cause erroneous ignition when the engine is at a reverse point.

[Means for solving problems]

The internal combustion engine ignition device according to the present invention includes a first sensor that generates a second angle signal corresponding to a second crank angle of the internal combustion engine, and a second sensor that generates a third angle signal. The ignition control means is configured to perform the ignition operation based on the generation of both the second and third angle signals.

[Effect]

The ignition control means in this invention includes the second and third
By generating both of the angle signals, it is detected that the internal combustion engine is at the second crank angle and in a normal rotation state, and an ignition operation is performed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a second pickup 20 is a second sensor installed together with the first pickup 3 described above, and is installed on the retard side of the rotation angle of the rotor 1 by θ ₂ . Therefore, as the rotor 1 rotates in the normal direction, an output signal delayed in phase by θ ₂ from the output signal of the first pickup 3 is obtained from the second pickup 20. 21 is a third diode, the anode of which is connected to the second pickup 2.
Connected to 0. 22 is a gate circuit which constitutes ignition control means together with the flip-flop 6 and the transistor 7; its first input terminal is connected to the cathode of the third diode, and its second input terminal is connected to the anode of the second diode 5; , whose output terminals are respectively connected to the reset input terminals of the flip-flop 6 described above, and output "0" only when the first input terminal is "1" and the second input terminal is "0"; When the input condition is met, a "1" output is generated. FIG. 2 shows the output voltage waveform of the pickup. From the first pick-up 3, the rotor 1
A positive _wave and a negative wave are output with an angular interval of θ ₁ corresponding to the protrusion width of Since positive waves and negative waves, which are signals, are output, the second waveform is set so that θ ₁ and θ ₂ are equal.
By installing the pickup 20, it is possible to synchronize the negative wave, which is the second angle signal of the first pickup 3, and the positive wave, which is the third angle signal, of the second pickup 20 at substantially the same timing.

FIG. 3 is an operational waveform diagram for explaining the operation of the device shown in FIG. 1, in which x indicates the output voltage waveform of the second pickup 20, and y indicates the output voltage waveform of the gate circuit 22. That is, when the front end A of the protrusion of the rotor 1 faces the first pick-up 3,
A positive wave is emitted from the first pickup 3, the flip-flop 6 enters the set state, and the primary current to the ignition coil 8 begins to flow. than that θ ₂
When the rotor 1 rotates in the normal direction, the front end A of the rotor 1 becomes
facing the second pickup 20 and rotor 1
Since the rear end B is configured to face the first pickup 3, a negative wave is transmitted from the first pickup 3 to the second pickup 20 at almost the same time.
A positive wave is output from each. The gate circuit 22 receiving both outputs has its first input terminal at "1" and its second input terminal at "0".
The output of the gate circuit 22 becomes "0" and the flip-flop 6 is reset. Ignition coil 8-1
Next, the current is cut off and an ignition spark is emitted from the ignition plug 11.

Next, the operation at the time of reverse rotation, which was a problem with the conventional device, will be described with reference to the operation waveform diagram in FIG. After starting, the rotor 1 rotates forward, and the A end faces the first pickup 3, and the ignition coil 8
The primary current begins to flow. If end A then begins to reverse before reaching the second pick-up 20, when the rotor 1 reverses and end A passes through the first pick-up 3, a negative wave will be emitted from the first pick-up 3. It will be done. However, during the above-mentioned series of rotations of the rotor 1 from normal rotation to reverse rotation after the start of the engine, the second pickup 20 does not have any protrusions facing the second pickup 20, so no output is generated from the second pickup 20. Therefore, when the second input terminal of the gate circuit 22 is "0", the first input terminal is also "0", so the output of the gate circuit 22 remains "1". Therefore, the Q output of the flip-flop 6 is not inverted and remains at "1", so the transistor 7 is not turned off and the primary current of the ignition coil is not cut off, so no high voltage is generated on the secondary side. , no ignition takes place.

Note that in the above embodiment, the first pickup 3
and a common rotor 1 for the second pickup 20.
However, the first and second rotors may be provided and combined with the first and second pickups, respectively, and the same effects as in the above embodiment can be obtained.

Further, the output polarities of the first and second pickups are not limited to those in the embodiment, and may be modified as shown in FIG. 5, for example. In this case, it is obvious that the same effect can be achieved if the operating polarity of the gate circuit 22 is changed accordingly.

Although the gate circuit 22 is also described as a logic gate in the above embodiment, it can also be configured with a transistor thyristor or the like. For example, when outputting a pick-up as shown in FIG. 3, the second pick-up 20
Turns on the transistor or thyristor with a positive wave of
It is sufficient to pass the negative wave of .

Furthermore, the output waveform of the pickup is not limited to the output waveform of a magnetic pickup as in the above embodiment, but also the output waveform of a proximity switch or a hall.
It is also effective for square wave type devices such as those found in ICs and optical sensors. The point is to detect that the output of the first pickup and the output of the second pickup are generated simultaneously, and to perform the ignition operation based on this.

Furthermore, a CDI type other than the current ignition type or intermittent ignition type as in the embodiment may be used.

〔Effect of the invention〕

As described above, according to the present invention, since the structure is such that no ignition spark is emitted when the engine is reversed,
This has the effect of providing a safe device that does not destroy the engine.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention, FIGS. 2, 3, and 4 are operation waveform diagrams for explaining the operation of the device shown in FIG. 1, and FIG. 5 is another embodiment. Figure 6 is the circuit diagram of the conventional device.
7, 8, and 9 are operational waveform diagrams for explaining the operation of the device shown in FIG. 6. 1 is a rotor, 3 and 20 are first and second pickups, 4, 5 and 21 are diodes, 22 is a gate circuit, 6 is a flip-flop, 7 is a transistor, 8 is an ignition coil, and 11 is a spark plug.
In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1 A first sensor that generates first and second angle signals corresponding to first and second crank angles of the internal combustion engine, and a third angle signal that generates a third angle signal that corresponds to the second crank angle of the internal combustion engine. a second sensor that generates
and controlling the primary current of the ignition coil based on the first, second and third angle signals, and controlling the primary current of the ignition coil based on the first, second and third angle signals;
An internal combustion engine ignition device comprising an ignition control means that performs an ignition operation based on the generation of both angle signals.