JPS60249669A - Igniter for internal-combustion engine - Google Patents

Abstract

PURPOSE:To secure an accurate timing advance motion all the time, by comparing a chopping wave voltage to be secured at both ends of an integrating capactor with a triangular wave voltage to be secured at both ends of a pumping-up capacitor and thereby generating an ignition signal. CONSTITUTION:An ignition circuit 10 makes an exciter coil 6 an ignition power source and secures the ignition motion in controlling a primary current of an ignition coil 1 through a discharge controlling thyristor 4. In this case, when an ignition signal is fed to the thyristor 4 and the ignition timing is set, an integrating capacitor 28 being charged in a range from a generating position of a signal VS2 to be generated later in two signals VS1 and VS2 out of a signal coil 12 to the next generating position of the signal VS2 and a pumping-up capacitor 40 being charged for constant voltage in a moment both are installed. And, according to the result of comparison between a triangular wave voltage and a square wave voltage secured at both ends of each of these capacitors 28 and 40, an igniter is so constituted to generate the ignition signal at the generating position of the signal VS1 or VS2.

Description

Detailed Description of the Invention [Industrial Application Field 1] The present invention uses an exciter coil that induces an alternating current voltage in synchronization with the rotation of an internal combustion engine as a power source, and a signal that induces a signal in synchronization with the rotation of the engine. The present invention relates to an ignition device for an internal combustion engine that uses a coil as a signal source and generates a high voltage to be applied to a spark plug for engine ignition at the ignition timing of the engine by controlling the primary current of the ignition coil.

[Prior Art] In an ignition system for an internal combustion engine, it is necessary to control the ignition timing of the engine according to the engine speed (rpm), and it is necessary to have an ignition characteristic that meets the requirements of the engine. An igniter must be provided. One of the ignition characteristics often requested by engines is the characteristic of advancing the ignition timing in steps when the engine speed reaches a set value. Conventional ignition systems that achieve this type of ignition characteristic detect the engine speed and advance the ignition timing by a predetermined angle when the engine speed reaches a set value. Since the rotation speed was detected by the output of the exciter coil that supplies energy or the output of the signal coil that obtains the ignition signal, the gear between the rotor and stator of the generator equipped with the exciter coil or signal coil is It is unavoidable that errors occur in the detected value of the rotational speed due to waveform variations due to fluctuations of 17 times, etc., and attempts to avoid this have the drawback of complicating the circuit and making the device expensive.

[Object of the Invention] An object of the present invention is to provide an ignition device for an internal combustion engine that has a simple configuration and can perform an accurate step advance operation without being affected by the waveform of a generator. There is a particular thing.

[Structure of the Invention] The ignition device for an internal combustion engine to which the present invention is directed uses an exciter coil that induces an alternating current voltage in synchronization with the rotation of the internal combustion engine as an ignition power source, and operates when an ignition signal is applied to a control signal input terminal. an ignition circuit that controls the primary current of an ignition coil to perform an ignition operation using a semiconductor switch; and an ignition timing determination circuit that determines the ignition timing by supplying the ignition signal to the primary current control semiconductor switch with the output of the signal coil induced at angular intervals as input, and the configuration of the present invention is as follows. It is as shown below.

(a) The ignition timing determining circuit includes: (b) a first circuit that supplies the ignition signal to the primary current control semiconductor switch with a signal of the second polarity generated after the signal generated from the signal coil; (b) a second signal supply circuit that supplies the ignition signal to the primary current control semiconductor switch when a signal of the first polarity whose phase leads that of the second signal is generated; (, b,) The second signal supply circuit includes (a) an integrating capacitor and a capacitor that charges the integrating capacitor to one of the 1i characteristics with a constant time constant using the output of the cylindrical coil. (b) a pump power supply capacitor that is charged to one polarity by the output of the exciter coil; and a pump-up switch circuit that conducts when triggered by a signal from the first pole layer 1; (c) a pump circuit that controls a pump-up capacitor that is charged through the pump-up switch circuit with the charge of the pump power supply capacitor; and (d) a comparison circuit that compares a triangular wave voltage obtained across the integrating capacitor with a rectangular wave voltage obtained across the pump up capacitor; a trigger circuit that is controlled by the output of the comparison circuit and supplies the ignition signal to the primary current control semiconductor switch when the rectangular wave voltage exceeds the triangular wave voltage at the time of rising; The charging time constant of the integrating capacitor is set so that the rectangular wave voltage exceeds the triangular wave voltage at the time of rise when the engine rotational speed exceeds a set value.

[Operation of the invention] In the above configuration, the basic operation of the ignition device is the same as that of the conventional device, and an ignition signal is sent from the ignition timing determining circuit to the semiconductor switch for primary current control of the ignition circuit at the ignition timing of the engine. When supplied, the primary current control semiconductor switch operates to control the primary current of the ignition coil and induce a high voltage for ignition in the secondary coil of the ignition coil. This generates a spark in the spark plug attached to the cylinder of the engine, igniting the engine.

In the ignition system of the present invention, when a voltage is generated in the exciter coil in synchronization with the rotation of the engine, the integrating capacitor of the integrating circuit is charged to one polarity in one half cycle of the voltage, and the terminal voltage of the integrating capacitor is It rises at a constant slope. The charge in this integrating capacitor is instantly discharged by the reset circuit when a signal of the second polarity is generated from the signal coil, so the terminal voltage of the integrating capacitor is the same as that of the next signal after the signal of the second polarity is generated. A triangular wave voltage rises at a constant slope until a signal of polarity 2 is generated.

On the other hand, in the pump circuit, the pump power supply capacitor is charged to one polarity by the output of the exciter coil. When the signal coil generates a signal of a first polarity, the pump up switch circuit conducts and charges the pump power capacitor with the charge on the pump power capacitor. When a signal of the second polarity is generated from the signal coil, the reset circuit instantly discharges the charge in the pump-up capacitor, so that the terminal voltage of the pump-up capacitor rises at the position where the signal of the first polarity is generated, and then the voltage of the second polarity increases. It becomes a rectangular wave voltage that falls at the position where the signal is generated.

The rectangular wave voltage and triangular wave voltage are supplied to a comparison circuit. When the engine speed is less than the set value, the rectangular wave voltage cannot exceed the triangular wave voltage at its rising edge, so the trigger circuit does not supply the ignition signal to the primary current control semiconductor switch.

Therefore, in the low speed region where the engine speed is less than the set value,
An ignition signal is given to the primary current control semiconductor switch by a signal of the second polarity from the first signal supply circuit, and the second
Ignition occurs at the location where a signal of polarity is generated.

When the engine speed exceeds the set 1iU, the rectangular wave voltage exceeds the triangular wave voltage at the rise of the rectangular wave voltage. is supplied to the primary current control semiconductor switch. Therefore, in the rotation range where the engine speed exceeds the set value, ignition is performed at the position where the first polarity signal is generated (when the square wave voltage rises or falls).
The engine's ignition timing is advanced in steps at the set rotation speed.

[Example] The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention. In the figure, 1 is an ignition coil having a primary coil 1a and a secondary coil 1b, and 2 is an ignition coil attached to a cylinder of an engine (not shown) to ignite. ] This is a spark plug connected to the secondary coil of coil 1. One ends of the primary coil 1a and the secondary coil 1b are grounded, and one end of an ignition energy storage capacitor 3 is connected to the non-grounded terminal of the primary coil 1a. A discharge control thyristor 4 is connected between the other end of the capacitor 3 and the ground, with its cathode facing the ground, and the cathode of a diode 5'' is connected to the connection point between the anode of the thyristor 4 and the capacitor 3. One end of the exciter coil 6 is connected to the anode.
The other end is connected to the cathode of thyristor 4, and the die sub-
A diode 7 with its anode facing the ground side is connected between the cathode of the node 5 and the ground. A resistor 8 and a capacitor -9 are connected between the gate and cathode of the thyristor 4 in a series. The exciter coil 6 is installed in a magnet generator that rotates in synchronization with the engine, and generates an alternating current voltage vX in synchronization with the rotation of the engine as shown in FIG. It is configured.

In the ignition circuit 10, the exciter coil 6, the diode 5, and the capacitor 3 constitute a power supply circuit that causes the primary current to flow through the ignition coil 1, and the discharge control thyristor 4 causes the primary current to suddenly change at the ignition timing. A semiconductor switch for controlling the primary current is configured. This ignition circuit is well known as a capacitor discharge type ignition circuit, and in this ignition circuit, the capacitor 3 is charged to the polarity shown by the half-cycle output of the exciter coil 6 in the direction of the arrow shown in the drawing. FIG. 2B shows the change in the terminal voltage v3 of the rotation angle θ with respect to the rotation angle θ. Next, it's time to ignite, which will be described later! ! 11 decision circuit to luxury lister 4
Ignition (No. 8 (15 to determine the ignition low 1 light)
When the thyristor 4 is supplied, the thyristor 4 becomes conductive, and the charge of the capacitor 3 is discharged through the thyristor 4 and the primary coil 1a of the ignition coil 1. Since this discharge occurs instantaneously, a large magnetic flux change occurs in the iron core of the ignition coil 1, and a high voltage for ignition is induced in the secondary coil 1b. Since this high voltage is applied to the ignition plug 2, a spark is generated in the ignition plug and the engine is ignited.

A cathode of a diode 11 is connected to the thyristor 40 gate 1 of the ignition circuit 10, and an anode of the diode 11 is connected to one end of a signal coil 12. The other end of the signal coil 12 is connected to the cathode (ground) of the four-noirister 4. The signal coil 12 is provided in a signal generator that rotates in synchronization with the rotation of the engine, and is shown in FIG.
As shown in FIG. 2, a first polarity signal VSI and a second polarity signal VS2 are sequentially generated. Here, the signal generator generates a signal VS1 of a first polarity at an ignition timing θ11 in a medium-high speed region of the engine (region above the set rotation speed), and generates a signal VS2 of a second polarity at a low speed of the engine. Ignition timing θ12 (θ11
It is configured so that it occurs at an angle closer to the top dead center of the engine. This signal valve ff1ll may be provided separately from the magnet generator provided with the exciter coil, or may be configured using a part of the rotor 11 poles of the magnet generator. In this example, the signal coil 12 and the diode 11 constitute a first signal supply circuit that supplies an ignition signal to the thyristor 4 using a second signal obtained from the signal coil 12.

A diode 2 is connected to the non-grounded terminal of the exciter coil 6.
The anode of the diode 20 is connected to the diode 20, and the cathode of the diode 20 is connected to one end of a power supply capacitor 22 via a resistor 21. The other end of the power supply capacitor 22 is grounded, and Zener diodes 23 with their anodes facing the ground are connected in parallel to both ends of the power supply capacitor 22. A voltage dividing circuit consisting of a series circuit of resistors 24 and 25 is connected in parallel to both ends of the Zener diode 230, and the base of the transistor 26 is connected to the voltage dividing point of the voltage dividing circuit. The emitter of the transistor 26 is connected to the cathode of a Zener diode 23 via a resistor 27, and an integrating capacitor 28 is connected between the collectors of the transistors 1 to 1 and ground. The components from the diode 20 to the integrating capacitor 28 constitute an integrating circuit 3o. In this integration circuit, a diode 20, a resistor 21, a diode 20, a resistor 21,
2 and the Zener diode 23 constitute a power circuit that uses the exciter coil 6 as a power source, and this power circuit and the
- A capacitor charging circuit that charges the integrating capacitor at a constant time constant is configured by the transistor 26 and a constant current circuit consisting of resistors 24, 25 and 28. The waveform of the voltage V22 across the capacitor 22 changes as shown in FIG. 2G with respect to the rotation angle θ of the engine. This voltage causes 1
An integral capacitor 28 is charged with a constant current through the resistor 26, and the voltage across the capacitor 28 increases with a constant slope as shown in FIG. 2B.

One end of a resistor 31 is connected to the cathode of the diode 20, and the other end of the resistor 31 is connected to one end of a pump power supply capacitor 32. The other end of the capacitor 32 is grounded, and a Zener diode 3 is connected to both ends of the capacitor 32.
The collector of a transistor 34 is connected to the non-grounded terminal of the parallel capacitor 32 with the anode 3 facing the ground side, and the base of the transistor 34 is connected to the cathode of a diode 35 whose anode is grounded. One end of a capacitor 36 is also connected to the base of the transistor 34, and the other end of the capacitor 36 is connected to one end of the signal coil 12 via a resistor 37 and a diode 38. The emitter of the transistor 34 is connected to the anode of a diode 39, and a pump-up capacitor 40 is connected between the cathode of the diode 39 and ground. resistance 3
A pump circuit 41 is constituted by each of the components 1 to 40, and in this pump circuit, the transistor 3
4, a diode 35, a capacitor 36, a resistor 37, and a diode 38 constitute a pump-up switch circuit. A signal VS1 of the first polarity is applied to the signal coil 12.
When this occurs, current flows from the signal coil 12 through the diode 35, capacitor 36, resistor 37, and diode 38, and the capacitor 36 is charged. When the charging voltage of this capacitor "38" reaches a predetermined value, the transistor "38"
4 conducts and transfers the charge of capacitor 32 to capacitor 40. As a result] capacitor 0 instantly changes to capacitor 3
The battery is charged to a charging voltage of 2 (constant regardless of the rotation speed).

One end of the non-grounded side of the integrating capacitor 28 of the integrating circuit 30 and the pump-up capacitor 4 of the pump circuit 41
One end of the non-grounded side of 0 is connected to a diode 60 and 61, respectively.
The cathodes of both diodes are commonly connected and connected to the collectors of transistors 1 to 2 whose emitters are grounded. The bases of 1 to 2 are resistors 6 connected in parallel to both ends of the signal coil 12.
A diode 60;
, and resistors 63 and 64 constitute a reset circuit 65. In this reset circuit, as soon as the signal VS2 of the second polarity is generated in the signal coil 12, the transistor 62 becomes conductive, and the transistor 62 becomes conductive.
and 40 are instantly discharged.

In this way, the integrating capacitor 28 receives the signal V of the second polarity.
Integrating capacitor 28 is reset by S2.
As shown in FIG. 2B, the voltage V28 obtained at both ends of
The voltage becomes a triangular wave voltage that rises at a constant slope (during 360 degrees) up to the generation position θ12 of the signal VS2 of polarity. The waveform of the triangular wave voltage V28 with respect to the rotation angle when the engine speed (rpm) is N1°N2 (>Nl) is as shown by the chain line in Fig. 2C, and the slope of the triangular wave voltage changes as the engine speed increases. It becomes smaller as a result. Furthermore, since the pump-up capacitor 40 is also instantaneously discharged through the reset circuit by the second polarity signal VS2, the waveform of the terminal voltage V40 of the capacitor 40 has a peak value as shown by the solid line in FIG. 2C. It becomes a constant square wave voltage regardless of the rotation speed.

Terminal voltages V28 and V2 of the capacitors 28 and 40
O is input to the comparison circuit 70 and compared.

The comparator circuit 70 of this embodiment includes a transistor 71, a capacitor 72 and a resistor 73 connected in parallel between the collector of the transistor 71 and the ground, and the collector of the transistor 71 is connected to the non-ground terminal of the capacitor 40. ,
Further, the bases are connected to the non-ground terminals of the capacitor 28, respectively.

In this comparison circuit 70, when the rectangular wave voltage V40 obtained across the capacitor 40 is less than the triangular wave voltage V28 obtained across the capacitor 28, the transistor 71 is in a cutoff state, and the rectangular wave voltage V40 exceeds the triangular wave voltage V28. Then, the transistor 71 becomes conductive and discharges the charge in the capacitor 40. Therefore, as shown in FIG. 2C, when the engine rotational speed reaches N2 and the rectangular wave voltage V40 exceeds the triangular wave voltage V28, the resistor 73 connected to the emitter of 1 to Rangistaph 1 is connected to both ends of the resistor 73 as shown in the second diagram. A pulsed signal voltage V73 is obtained.

The non-grounded terminal (output terminal of the comparison circuit) of the resistor 73 of the comparison circuit 70 is connected to the base of the transistor 80,
The collector of the transistor 80 is connected to the cathode of the Zener diode 23. Further, the emitter of the transistor 80 is connected to the seventh node of a diode 81, and the cathode of the diode 81 is connected to the gate of the thyristor 4. A trigger circuit 82 is constituted by a 1H transistor 80 and a diode 81. In this trigger circuit, a pulse signal V73 is sent from the comparator circuit 70.
When is applied, the transistor 80 becomes conductive, and an ignition signal is applied from the capacitor 22 side to the thyristor 4, thereby making the thyristor conductive and performing an ignition operation.

In this embodiment, a second signal supply circuit is constituted by the integration circuit 30, the pump circuit 41, the reset 1 circuit 65, the comparison circuit 70, and the trigger circuit 82, and the second signal supply circuit An ignition timing determining circuit is constituted by this circuit and a first signal supply circuit consisting of the signal coil 12 and diode 11.

In the above embodiment, when the engine rotation speed N is less than the set rotation speed, for example, when N=N1, when the rectangular wave voltage V40 is generated across the capacitor 40 in FIG. Since the triangular wave voltage V28 obtained at 1 is higher than the rectangular wave voltage V40, the transistor 71 of the comparator circuit 71 is not conductive, and the pulse signal voltage V73 is not generated across the resistor 73. At this time, the signal coil 12
An ignition signal is supplied to the thyristor 4 through the diode 11 by the second polarity signal Vs2 obtained from the second polarity signal Vs2, and ignition is performed at the generation position θ12 of the second polarity signal. On the other hand, when the engine speed reaches the set value N2, the second
As shown in FIG.
3 occurs, and the pulse signal causes the trigger circuit 82 to
A base current is supplied to transistor 80. As a result, an ignition signal is supplied to the thyristor 4, and an ignition operation is performed. Therefore, when the engine speed reaches the set value, the ignition operation is performed at the rising edge of the square wave voltage V40 (the position where the first polarity signal is generated), as shown in Figure 3. In addition, the ignition timing θi is advanced in steps from θ12 to θ11.

Note that FIG. 2H shows the high voltage vh for ignition generated in the secondary coil of the ignition coil 1 at angles θ11 and θ12, respectively.

In the above embodiment, a capacitor discharge type circuit is used as the ignition circuit, but the ignition circuit used in the present invention is a primary current control semiconductor whose operation timing is determined by giving an ignition signal by the output of a signal coil. Any circuit that uses a switch to control the primary current of the ignition coil to obtain high voltage for ignition is sufficient, and the primary current is supplied to the primary circuit of the ignition coil by the operation of the semiconductor switch for controlling the primary current at the engine ignition timing. Of course, the present invention can also be applied to the case where a well-known current interrupting type ignition circuit is used, in which the primary current of the ignition coil is abruptly changed by interrupting the applied current to perform the ignition operation. .

In the above embodiment, a constant current circuit consisting of the transistor 26 and the resistors 24, 25, and 27 was provided in the integrating circuit 30 to charge the capacitor +f2B with a constant current, but as shown in FIG. It is also possible to simply charge the integrating capacitor 28 with the voltage across the Zener diode 23 through the resistor 27. In this case, the waveform of the voltage 28 across the integrating capacitor 28 becomes a slightly curved triangular waveform as shown in FIG. 4C. The triangular waveform referred to in the present invention also includes the waveform shown in FIG. 4C.

In the embodiment shown in FIG. 1, the pump power supply capacitor 32 is charged by the output of the exciter coil 6 through the resistor 31, but as shown in FIG. The voltage obtained by dividing the voltage with a voltage dividing circuit consisting of a series circuit causes the capacitor 32 to
You may also charge the battery. In this way, the withstand voltage of the capacitor 32 and the parts of the pump circuit connected to the capacitor can be lowered.

[Effects of the Invention] As described above, in the present invention, among the first and second polarity signals generated from the signal coil, the next second polarity signal is detected from the generation position of the second polarity signal generated later. An integrating capacitor that is charged at a constant time constant until the position where a signal of the first polarity is generated is provided, and a pump-up capacitor that is instantly charged with a constant voltage at the position where a signal of the first polarity is generated. The triangular wave voltage obtained at both ends of the pump-up capacitor is compared with the rectangular wave voltage obtained across the pump-up capacitor, and when the rectangular wave voltage is less than the triangular wave voltage, an ignition signal is given by the second polarity signal, and when the rectangular wave voltage rises, the ignition signal is applied. Since the ignition signal is given at the position where the first polarity signal is generated when the triangular wave voltage is exceeded, the set rotation speed is accurately detected and advanced without being affected by the output waveform of the exciter coil. can be made to perform an action. In addition, the power for the integrating circuit and pump circuit is supplied from the exciter coil, and the output of the signal coil is used only for signals, so even if the output of the signal coil is small, it can operate sufficiently, and the signal generator used Miniaturization can be achieved. Further, the set rotational speed at which the advance angle operation is performed can be easily set to an appropriate value by appropriately setting the charging time constant of the integrating capacitor, and the circuit setup 51 can be facilitated. .

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing one embodiment of the present invention, Fig. 2 is a waveform diagram showing the operating waveforms of each part of Fig. 1 with respect to the rotation angle of the engine, and Fig. 3 is a waveform diagram showing the operating waveforms of each part in Fig. 1 with respect to the rotation angle of the engine. FIG. 4A is a connection diagram showing a modified example of the integrating circuit used in the present invention, and FIGS. 4B and C are graphs showing the signal voltage obtained in the signal coil and A waveform diagram showing the triangular wave voltage obtained in the circuit, and FIG. 5 is a connection diagram showing the main parts of a modified example of the pump circuit used in the present invention. DESCRIPTION OF SYMBOLS 1... Ignition coil, 2... Spark plug, 3... Capacitor, 4... Thyristor (semiconductor switch for primary current control), 5... Diode, 6... Exciter coil, 10... ...Ignition circuit, 12...Signal coil,
20...Diode, 21...Resistor, 22...Power supply capacitor 24.25.27...Resistor, 26...
Transistor, 28... Integrating capacitor, 30...
Integrating circuit, 31...Resistor, 32...Pump power supply capacitor, 33...Zener diode, 34...1
~Ran resistor, 40...Pump up capacitor, 6
2...Transistor, 65...Reset circuit, 70
...comparison circuit, 71...what transistor, 73...
Resistor, 80...Transistor, 81...Diode, 82...Trigger circuit. Figure 3 Figure 4

Claims (1)

[Claims] The ignition power source is an exciter coil that induces an alternating current voltage in synchronization with the rotation of the internal combustion engine, and the primary current of the ignition coil is generated by a semiconductor switch that operates when an ignition signal is applied to the control signal input terminal J. an ignition circuit that controls the internal combustion engine to perform an ignition operation; and an output of a signal coil that sequentially induces a first polarity signal and a second polarity signal at predetermined angular intervals in synchronization with the rotation of the internal combustion engine. An ignition device for an internal combustion engine, comprising: an ignition timing determination circuit that supplies the ignition signal to the primary current control semiconductor switch as an input to determine the ignition timing, wherein the ignition timing determination circuit includes a signal generated from the signal coil; a first signal supply circuit that supplies the ignition signal to the primary current control semiconductor switch with a signal of the second polarity generated from the direction of the signal; a second signal supply circuit that supplies the ignition signal to the primary current control semiconductor switch when a signal of 10 polarities is generated, the second signal supply circuit comprising: an integrating capacitor and an output of the exciter coil; a capacitor charging circuit that charges the integrating capacitor to one polarity with a constant time constant; a pump power supply capacitor that is charged with a constant voltage to one polarity by the output of the exciter coil; and the first polarity. a pump circuit including a pump-up switch circuit that conducts when triggered by the signal, and a pump-up capacitor that is charged through the pump-up switch circuit with the charge of the pump power supply capacitor; and the signal of the second polarity is generated. a reset circuit that instantaneously discharges the integrating capacitor and the pump-up capacitor when the integration capacitor and the pump-up capacitor are in contact with each other; a trigger circuit that is controlled by the output of the comparator circuit and supplies the ignition signal to the primary current control semiconductor switch when the rectangular wave voltage exceeds the triangular wave voltage at the time of rising; the integral so that the rectangular wave voltage exceeds the triangular wave voltage at the rising edge when the voltage exceeds the set value]
An ignition device for an internal combustion engine, characterized in that a constant charging time constant is set.