JPH0422065Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to an ignition device for an internal combustion engine, and is particularly intended to prevent malfunctions that occur when the engine is reversed.

[Conventional technology]

Figures 5 and 6 show a conventional ignition system as shown in, for example, Japanese Utility Model Publication No. 58-25054. In Figure 5, 1 is a flywheel that rotates in synchronization with the engine, and 1a is a flywheel that rotates in synchronization with the engine. A protrusion 2 provided on the flywheel 1 is a pickup comprised of a magnet and a coil (both not shown) that generate advance angle signals and retard angle signals in response to changes in the magnetic field caused by the protrusion 1a. In addition, in FIG. 6, 3 is a generator coil housed in a magnet generator that generates an electromotive force according to the rotation of the engine, 5 is a capacitor that charges the ignition voltage from the generator coil 3 through a diode 4 and an ignition coil 12. , 7, 8, 9, and 10 are diodes for rectifying the AC voltage generated in the pickup 2, and 11 is a resistor connected to the diode 7.
6 is a thyristor that discharges the charge of the capacitor 5 to the ignition coil 12, and the gate has a resistor 1.
1. Diode 9 is connected.

Next, the operation will be explained. First, when the flywheel 1 is rotating clockwise as shown in Fig. 5, positive and negative voltages as shown in Fig. 7a are generated at the positions shown in Fig. 5A and Fig. 5B, respectively. do. The positive voltage that is the advance angle signal is applied to the thyristor 6 through the diode 10, diode 7, and resistor 11.
The negative voltage that is the retard signal is applied to the gate of the thyristor 6 through the diode 8 and the diode 9.
is applied to the gate of By the way, when the engine is started, the rotation of the flywheel 1 is low, so the output voltage of the pickup 2 is also low, and the positive voltage that is the advance signal of the pickup 2 is lowered by the resistor 11, as shown in FIG. 7b. On the other hand, the negative voltage, which is the _retard signal, is directly applied to the thyristor 6 through the diode 9.
Since the trigger voltage V _T is applied to the gate of
The above voltage is supplied, triggering the thyristor 6 and making it conductive. Therefore, in the retard position, the charge in the capacitor 5 is discharged, and the ignition coil 12 generates an ignition voltage to start the engine. Next, after the engine starts, the positive voltage that is the advance angle signal increases as the rotation increases, and when it reaches the trigger voltage V _T of the thyristor 6, the thyristor 6 is triggered by the advance angle signal. Since the ignition voltage is generated at the advanced angle position, the engine rotates more stably.

[Problem that the invention attempts to solve]

Since the conventional ignition device is constructed as described above, it has the following drawbacks. Generally, the retard signal is set near the top dead center of the engine in consideration of startability, and when starting, the retard signal is set at the position shown in Figure 5A to the position where the retard signal is generated as shown in Figure 5B. If the rotation is reversed again to the position shown in FIG. 5A due to the compression pressure of the engine, a reversal retard signal is generated at the advanced angle position during normal rotation, as shown in FIG. 7c. Since this signal is in the same direction as the retard signal during normal rotation, it becomes a voltage higher than the trigger voltage V _T as shown in FIG. 7d, and the thyristor 6 is triggered to generate an ignition voltage. At this time, in the reverse direction, the engine would be after top dead center, resulting in an incorrect explosion, and the engine would explode. There was a problem that caused problems such as backfire.

This idea was made to solve the above-mentioned problems. An object of the present invention is to obtain an ignition device for an internal combustion engine that can prevent improper ignition that causes backfire.

[Means for solving problems]

The ignition device according to this invention includes a first signal generating means that generates an advance angle signal and a retard signal, and a pair of signals that generates a pair of signals at times before and after the retard signal when the engine rotates in the forward direction, and a first signal generating means when the engine rotates in the forward direction. A second signal generating means is provided which generates a pair of signals at an early stage in response to the retarded signal generated by the signal generating means, and based on the signal from the second signal generating means, when the engine is reversed, the retarded signal is invalidated and ignition is started. It is constructed to prevent the generation of voltage.

[Effect]

The ignition device according to this invention is characterized in that the first signal is generated within the period in which the second signal generating means generates the pair of signals.
When a retard signal is generated in the signal generating means,
Ignition voltage is generated by this signal, and if a retard signal is generated at a time that is different from the pair of signal generation periods, the retard signal is invalidated to prevent the generation of ignition voltage and prevent unauthorized explosion of the internal combustion engine. It becomes possible to do so.

[Example of idea]

An embodiment of this invention will be described below with reference to the drawings. In FIG. 1, 1a and 1b are a first protrusion and a second protrusion formed on the outer periphery of the flywheel 1, respectively, and 2 is a first pick-up disposed corresponding to the first protrusion 1a. This forms a first signal generating means that generates an advance angle signal and a retard angle signal by passage of the first protrusion 1a. Reference numeral 13 denotes a second pick-up disposed corresponding to the second protrusion 1b, which generates a pair of positive and negative voltages at times before and after the retard signal generated by the first pick-up 2 during forward rotation. At the same time, a second signal generating means is formed which generates a pair of voltages earlier than the retard signal during reverse rotation. Note that the protrusions 1a, 1b and the pick-ups 2, 13 are arranged offset in the axial direction so as not to interfere with each other, as shown in FIG. 1B. Also, in FIG. 2, the same reference numerals as in FIG. 6 indicate the same configurations, 14 and 15 are diodes for detecting positive and negative signals from the second pickup 13, and 16 is a diode for detecting the positive and negative signals from the second pickup 13. RS where the input signal is supplied
A flip-flop, 17, is a transistor that becomes conductive in response to the output Q of the RS flip-flop 16.
A resistor 19 connected to the collector of the transistor 17 is a transistor connected between the diode 9 and the gate of the thyristor 6, and is configured such that current flows through the resistor 18 when the transistor 17 is turned on.

Next, the operation will be explained based on FIGS. 3 and 4. When the flywheel 1 is rotating forward (clockwise), the first pickup 2 generates a positive advance angle signal as shown in FIG. 4a at the positions shown in FIGS. 3A and 3c. Generates a negative voltage that is a voltage and a retard signal. This advance angle signal is transmitted through diode 7,
10, is supplied to the gate of the thyristor 6 through the resistor 11, but at the time of starting, this voltage is not high enough and a voltage drop occurs due to the resistor 11, so the trigger voltage is reduced as shown in Figure 4d. V _T is not reached and thyristor 6 does not conduct.

On the other hand, the second pickup 13 generates a positive voltage and a negative voltage as shown in FIG. 4b at the positions shown in FIGS. 3B and 3D, and the positive voltage is
The negative voltage resets the RS flip-flop 14 to produce an output Q while setting the RS flip-flop 14 to produce a square wave as shown in FIG. 4c. This rectangular wave makes the transistor 17 conductive, and in this conductive state, the retard signal from the first pickup 2 is supplied to the transistor 19, so the transistor 19 becomes conductive and the trigger voltage increases as shown in FIG. 4d. A voltage equal to or higher than V _T is applied to the thyristor 6 to make the thyristor 6 conductive, thereby generating an ignition voltage as in the conventional case.

Next, a case will be described in which the engine is unable to overcome compression top dead center during startup and is reversed. That is,
When the flywheel 1 rotates counterclockwise from the position shown in FIG. 3D to the position shown in FIG. 3A, a positive voltage is first generated in the second pickup 13, as shown in FIGS. A positive voltage, which is an advance angle signal, is generated at the pickup 2. Furthermore, the negative voltage at the second pickup 13 is applied to the first pickup 2.
A negative voltage, which is a retard signal, is generated. That is, positive and negative voltages are generated by the second pickup 13 at an earlier stage with respect to the retarded signal formed by the first pickup 2, as shown in FIGS. 4e and 4g. When the first pick step 2 generates a retard signal, the RS flip-flop 16 does not generate the output Q, and therefore the transistor 17 is made non-conductive, so that the output of the diode 9 is not supplied to the thyristor 6, and the thyristor 6 is triggered. Never. Note that since the advance angle signal is limited by the register 11, it does not similarly trigger the thyristor 6.

In this way, by limiting the retard signal generated when the engine is reversed by the signal from the second pickup 13, generation of ignition voltage can be prevented and unauthorized explosion can be prevented.

In the above embodiment, the second protrusion 1b was formed to have approximately the same size as the first protrusion 1a, but a pair of protrusions were formed corresponding to the front and rear edges of the second protrusion 1b. It may be arranged such that a protrusion is provided and the RS flip-flop 16 is controlled by a pair of positive voltages generated by the protrusion.

In the above embodiment, the ignition device performs jump advance by applying the advance angle signal and the retard angle signal to the gate of the thyristor 6. The same can be applied to advance ignition devices.

[Effect of idea]

As described above, according to this invention, a second signal generation means is provided, and a pair of signals are generated at positions before and after the retard signal when the engine rotates in the normal direction, and at a position earlier than the retard signal when the engine rotates in reverse. By generating a pair of signals, it is possible to prevent unauthorized explosions during reverse rotation.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an ignition system according to an embodiment of this invention, Fig. 2 is a circuit diagram showing an ignition system according to an embodiment of this invention, and Figs. 3 and 4 are an embodiment of this invention. FIG. 5 is a configuration diagram showing a conventional ignition device; FIG. 6 is a circuit diagram showing a conventional ignition device; FIG.
The figure is a waveform diagram illustrating the operation of a conventional ignition device. 1 is a flywheel, 1a is a first protrusion, 1b
2 is the second protrusion, 2 is the first pickup, 3 is the generator coil, 4, 7, 8, 9, 10, 14, 15
is a diode, 5 is a capacitor, 6 is a thyristor, 13 is a second pickup, 16 is an RS flip-flop, 17 and 19 are transistors, 1
1 and 18 are registers, and 12 is an ignition coil.
Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of utility model registration request] A first signal generating means that generates an advance angle signal and a retard angle signal for the engine in response to a magnetic change caused by a first protrusion provided at a predetermined position of a flywheel that rotates in synchronization with the rotation of the engine, and engine starting. An ignition means that sometimes generates an ignition voltage by a retard signal to start the ignition, and receives a magnetic change due to a second protrusion provided at a position that does not magnetically interfere with the first protrusion of the flywheel. When the engine rotates normally, the first
A pair of signals are generated before and after the retard signal outputted by the first signal generating means, and when the engine is reversed, a pair of signals are generated earlier than the retard signal outputted from the first signal generating means. The second to generate
a signal generating means, a control means for generating a control signal of a predetermined rotation angle width in response to the pair of signals outputted by the second signal generating means, a control means inserted into the output circuit of the retard signal, In response to an output signal from the means, the output circuit is closed when the engine rotates in the normal direction;
passing the retard signal to generate an ignition voltage and opening the output circuit when the engine is reversed;
An internal combustion engine ignition device comprising a switch element that prevents the passage of the retard signal to prevent generation of an ignition voltage.