JPS6410666B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a non-contact ignition device for an internal combustion engine using a magnet generator, and particularly relates to a signal generation circuit for determining ignition timing.

Conventionally, when using a non-contact ignition system for internal combustion engines that uses a magnet generator, it is common to configure the ignition system with a built-in advance device. The advance angle is controlled by the output of the sensor, and the advance angle at the middle speed section can be controlled by using a transformer or the like to use a part of the output of the ignition capacitor charging coil as an advance signal, or at low speeds. A signal generating circuit was constructed by combining a sensor for fixing at high speeds and a sensor dedicated to advance angle at medium speeds.

However, in the former method mentioned above, which uses part of the output of the ignition capacitor charging coil to obtain the advance angle characteristics in the medium speed section, it is necessary to create circuit specifications according to the output of the ignition capacitor charging coil. Therefore, it is difficult to adapt to many types of magnet generators, and it is difficult to obtain sufficient advance angle characteristics. Furthermore, when a ferrite magnet is used in a magnet generator, there is a drawback that the ignition timing changes greatly with respect to changes in the ambient temperature of the magnet generator. On the other hand, the latter method in which a sensor for fixing the ignition timing at low speeds and high speeds is combined with a sensor dedicated to advancing the intermediate speed section requires two sensors, which has the drawback of high cost. In addition, since the lead angle characteristics are affected by the output waveform of the lead angle dedicated sensor,
If the required advance angle characteristic is changed, it cannot be handled without changing the magnetic pole shape, core shape, etc., and therefore there is a drawback that the degree of freedom in setting the advance angle characteristic is small.

The present invention uses the positive and negative outputs of one sensor and the positive output of the ignition capacitor charging coil of the magnet generator to control the advance angle characteristics consisting of a low-speed fixed section, a medium-speed advance section, and a high-speed fixed section. It's something you get. Its structure consists of a sensor that generates positive and negative pulse voltages with an angular interval θ corresponding to the advance width of the medium speed section, and the output of this sensor is used to respond to the rotation speed from the pulse generation position of one polarity. a reference voltage generation circuit that generates a rectangular wave having an angular interval width up to the ignition position or the pulse generation position of the other polarity; a constant voltage power supply circuit that obtains a constant voltage using the positive direction output of the ignition capacitor charging coil; The calculation capacitor is charged via a resistor from this constant voltage power supply circuit.
It is comprised of a discharge circuit that discharges the charge of the calculation capacitor during the interval of the above-mentioned angular interval θ, and a reset circuit that resets the charge of the calculation capacitor when a pulse of the other polarity is generated by the sensor. By determining the ignition timing by comparing the output voltage of the reference voltage generation circuit and the terminal voltage of the calculation capacitor, the low-speed fixed part,
The purpose is to realize advance angle characteristics consisting of a medium speed advance section and a high speed fixed section using the output of one sensor and a constant voltage power supply circuit obtained from the output of the ignition capacitor charging coil of the magnet generator. shall be.

The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 is an electrical circuit diagram showing a first embodiment of the device of the present invention, and 1000 is an ignition signal generating circuit. 1 is the capacitor charging coil of the magnet generator, 2
is an ignition coil consisting of a primary winding 2a and a secondary winding 2b, 3 is a spark plug, 4 to 7 are diodes,
8 is an ignition thyristor, 9 is an ignition capacitor,
10 is a sensor, 11-14 is a capacitor, 15-
18 is a transistor, 19 and 20 are Zener diodes, 21 to 26 are diodes, and 27 to 37 are resistors.

First, the operation of the entire ignition system will be explained. By the output of the capacitor charging coil 1 of the magnet generator,
When the ignition signal generation circuit 1000 applies an ignition signal to the gate of the thyristor 8 while the ignition capacitor 9 is charged via the diode 5, the thyristor 8 becomes conductive and the electric charge charged in the capacitor 9 becomes A sudden discharge occurs through the thyristor 8 and the primary winding 2a of the ignition coil 2, and at this time, an ignition spark is generated in the ignition plug 3 due to the high voltage generated in the secondary winding 2b of the ignition coil 2. Further, the diode 6 is provided for DC arc, but if omitted, it will be used for AC arc. Next, the signal generation circuit 10
The outline of the 00 will be explained based on the circuit diagram shown in FIG. 1 and FIG. 2 which shows a voltage waveform diagram of each part of the circuit during advance in the middle speed section. The sensor 10 includes a second
Positive and negative pulses shown in Figure a are generated. This positive,
The negative pulses are generated once per rotation of the magnet generator, and the interval θ corresponds to the advance angle width in the middle speed section. In Figure 1, resistor 27 and diode 2
6, a Zener diode 20, and a capacitor 14, the constant voltage power supply circuit 400 charges the calculation capacitor 13 via the resistor 34, but when the negative pulse of the sensor 10 (in the direction of the dashed arrow shown in FIG. 1) As shown in _FIG . 2a, when the output is applied to the base of the transistor 18 via the resistor 35, the transistor 18 becomes conductive and the charge stored in the calculation capacitor 13 is transferred to the reset circuit 500. It is instantaneously discharged through a portion of the diode 24 and the transistor 18. However, the calculation capacitor 13 is connected to the resistor 34
Since it is connected to the constant voltage power supply circuit 400 via the sensor 10, charging starts again when the negative pulse of the sensor 10 disappears, and its terminal voltage V _C13 gradually increases as shown in FIG. 2c.

Next, the sensor 10 in the direction of the solid arrow shown in FIG.
When a positive pulse occurs at position P _E as shown in FIG.
1 is charged, and the transistor 1 is charged through the resistor 29.
5 becomes conductive and the discharge circuit 100 operates to gradually discharge the charge stored in the calculation capacitor 13, so that the terminal voltage V _C13 of the capacitor 13 becomes as shown in Fig. 2c.
It begins to descend as shown in . This discharge is caused by sensor 1
The reset circuit 500 is operated by a negative pulse of 0, and terminates at the same time as the charge in the capacitor 11 is reset via the diode 23 and the transistor 18, so that the positive pulse generation position of the sensor 10 is
It lasts for the period from P _E to the negative pulse generation position P _S.
Therefore, the terminal voltage V _C13 of the calculation capacitor 13 has a triangular waveform as shown in FIG. 2c. Although the calculation capacitor 13 is always charged, since it is set so that (discharge current) > (charge current), only discharging apparently takes place in the section from P _E to P _S. It becomes like being.

On the other hand, the positive pulse from the sensor 10 charges the capacitor 12 with a constant voltage via the Zener diode 19 and the diode 22. The charge stored in the capacitor 12 is transferred to the thyristor 8 via the diode 7.
Since it is connected to the anode of the ignition position P, it is reset at the ignition position P. Furthermore, the terminal voltage of capacitor 12 is impedance-converted by an emitter follower made up of transistor 16 and resistor 31. That is, the positive pulse of the sensor 10 is converted by the reference voltage generation circuit 200 into a reference voltage V _STD having a rectangular waveform as shown in FIG. 2b.

This ignition device uses the calculation capacitor 13 described above.
The comparator 300 compares the difference between the terminal voltage V _C13 and the reference voltage V _STD , and when V _C13 becomes lower than V _STD by a certain potential (base-emitter voltage V _BE17 of transistor 17), It conducts and generates an ignition signal. below,
Based on the waveforms of V _STD and V _C13 , the low speed fixed part,
The operation in the medium speed advance part and the high speed fixed part is
This will be explained using the sensor output and calculation capacitor terminal voltage V _C13 waveforms shown in FIGS.

(1) Low-speed fixed part (see Figure 3) In this region, the charging time of the calculation capacitor 13 (the time required from P _S to P _E shown in Figure 2 c) is long, so the terminal voltage V _C13 is As shown in FIG. 3b, it is high and in a state of (V _STD - V _C13 < V _BE17 ). However, the moment V _C13 is reset by the negative pulse of sensor 10, the charge in calculation capacitor 13 is discharged and (V _STD −
V _C13 ) reaches V _BE17 and an ignition signal is generated. Therefore, the negative pulse generation position P _S becomes the ignition position.
In an extremely low rotational speed range near the starting rotational speed, the negative pulse from the sensor 10 is applied directly to the gate of the thyristor 8 via the resistor 36, thereby improving starting performance.

(2) Medium-speed advance part The charging time of the calculation capacitor 13 becomes shorter as the rotation speed increases, so its terminal voltage decreases.
V _C13 has a rotational speed of N _S → as shown in Figure 4b.
It gradually decreases as it increases as N ₁ →N ₂ →N _E (N _S <N ₁ <N ₂ <N _E ). On the other hand, the reference voltage V _STD
is constant, so the difference between the two (V _STD − V _C13 ) is
The position at which V _BE17 is reached, that is, the ignition position, advances from the low speed fixed position P _S to P ₁ and P ₂ as the rotational speed increases, and finally reaches the high speed fixed position _PE .
Furthermore, since V _STD is reset by conduction of the thyristor 8, the reset position also changes from P _S to P ₁ → P ₂ in the same way as the ignition position as the rotational speed increases.
→Move to P _E.

(3) High-speed fixed part (see Figure 5) As the rotation speed increases further, V _C13 decreases further, but since V _STD does not exist on the advance side of the positive pulse generation position P _E of the sensor, ( V _STD −V _C13 )
The position where V _BE17 is reached is the positive pulse generation position P _E
It becomes fixed at , and does not advance any further. Also,
Since V _STD is reset almost simultaneously with the generation of the positive pulse, the pulse waveform becomes as shown by the thick broken line in FIG. 5b.

Through the above operations, the ignition timing characteristics shown in FIG. 6 are obtained.

FIG. 7 shows a second embodiment of the present invention, which includes a bottom prevention circuit 600 and a reverse rotation prevention circuit 700. The asshole prevention circuit 600 forms a constant voltage power supply circuit for the reference voltage generation circuit 200, and when the calculation capacitor 13 is empty at startup, a positive pulse of the sensor 10 is generated, and even at low speeds. Regardless, it has a function to prevent the ignition position from advancing. Then, the charging time constant determined by the resistor 39 and capacitor 40 of the butt prevention circuit 600 is set to the constant voltage power supply circuit 400.
By setting the charging time constant of the capacitor 14 to be larger than the charging time constant of the capacitor 14, the operation of the transistor 16 is suppressed until the calculation capacitor 13 is charged, and the generation of the reference voltage V _STD is prevented.
Only the negative pulse of is passed through the resistor 36 to the thyristor 8
The voltage is applied to the gate of

On the other hand, the reverse rotation prevention circuit 700 prevents generation of an ignition signal and stops generation of reverse rotation driving force of the internal combustion engine when the internal combustion engine reverses for some reason. In this circuit, the phase relationship is set so that the polarity of the voltage generated by the ignition capacitor charging coil 1 of the magnet generator is negative during the period in which the positive and negative pulses of the sensor 10 are generated (another period corresponding to the advance width). By doing so, even if the ignition signal is applied to the gate of the thyristor 8 during reverse rotation, the polarity of the voltage generated by the ignition capacitor charging coil 1 will be positive, and this output will be applied to the transistor 4 via the resistor 41.
By making thyristor 2 conductive and short-circuiting between the gate and ground of thyristor 8, it is possible to prevent thyristor 8 from being conductive.

In each of the above-described embodiments, the diode 7 is connected between the capacitor 12 of the reference voltage generation circuit 200 and the anode of the ignition thyristor 8, and the ignition thyristor 8 is made conductive at the ignition timing. The reference voltage generated in the reference voltage generation circuit 200 is reset by instantaneously discharging the charge in the capacitor 12, but instead of the diode 7, a connection between the capacitor 12 and the collector of the transistor 18 of the reset circuit 500 By connecting a diode 7 as shown by the broken line in the figure, or by connecting a transistor that conducts synchronously with the transistor 18 in parallel between the terminals of the capacitor 12, the reset circuit 500 is set to the lowest advance position when it is in operation. The reference voltage generated in the reference voltage generation circuit 200 may be reset by instantly discharging the charge in the capacitor 12.

Furthermore, in each of the embodiments described above, other comparison switch elements such as a programmable union transistor (PUT) can be used in place of the transistor 17 constituting the comparator 300.

As described above, in the present invention, positive and negative polarity voltages are generated in the sensor at angular intervals corresponding to the ignition advance width, and a constant voltage is generated by the capacitor charging side half-wave output of the capacitor charging coil of the magnet generator. A calculation capacitor is gradually charged by a constant voltage obtained in the power supply circuit, and the charge in this calculation capacitor is gradually discharged by a discharge circuit at an angular interval corresponding to the ignition advance width, and is generated in the sensor. The charge in the calculation capacitor is instantaneously discharged at the lowest advance position by the voltage of the polarity of , and the voltage of the other polarity generated in the sensor is A reference voltage is generated from the maximum advance position by a reference voltage generation circuit using the voltage, and a comparison switch element is used to compare this reference voltage with the terminal voltage of the calculation capacitor whose peak voltage decreases as the engine speed increases. In comparison, when the terminal voltage of the calculation capacitor becomes lower than the reference voltage, the comparison switch element becomes conductive and applies a gate signal to the ignition thyristor.
And after this comparative switch element becomes conductive, the first
Since the reference voltage is reset by the second reset circuit until the second reset circuit operates, there are excellent effects as described below.

(1) Since the constant voltage of the constant voltage power supply circuit is obtained from the capacitor charging side half-wave output of the capacitor charging coil, a sufficient constant voltage can be obtained without using a battery, and the operation of each part is stabilized. One end of the charging coil can be grounded.

(2) Since the ignition timing is determined by comparing the charging/discharging waveform of the calculation capacitor with the reference voltage using a comparison switch element, there is a large degree of freedom in setting the advance angle characteristic. Moreover, the low-speed fixed part (lowest advance position) and high-speed fixed part (highest advance position) are matched with the negative and positive pulses of the sensor, respectively, so the stability of the ignition timing of the fixed part is very good. .

(3) The ignition timing characteristics consisting of the low-speed fixed part, medium-speed advance angle part, and high-speed fixed part are controlled by one sensor and a magnet generator that generate positive and negative pulses at angular intervals corresponding to the middle-speed advance width. Since it can be realized only from the output of the ignition capacitor charging coil, it is possible to provide an ignition device with a simple circuit configuration and low cost.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram showing a first embodiment of the device of the present invention, FIGS. 2 to 5 are waveform diagrams of various parts for explaining the operation of the device shown in FIG. 1, and FIG. The ignition timing characteristic diagram, FIG. 7, is an electric circuit diagram showing a second embodiment of the device of the present invention. DESCRIPTION OF SYMBOLS 1... Capacitor charging coil, 2... Ignition coil, 3... Spark plug, 7... Diode constituting the second reset circuit, 8... Thyristor for ignition, 9... Capacitor for ignition, 10... Sensor ,
13...Arithmetic capacitor, 17...Transistor as a comparison switch element, 100...Discharge circuit, 200...Reference voltage generation circuit, 400...
Constant voltage power supply circuit, 500...first reset circuit, 600...assistance prevention circuit as a constant voltage power supply circuit.

Claims (1)

[Scope of Claims] 1. A capacitor charging coil of a magnet generator, an ignition capacitor that is charged via a half-wave rectifier diode by the capacitor charging side half-wave output of this charging coil, and igniting the charged charge of this capacitor. an ignition thyristor for discharging through the primary winding of the coil, and a voltage of positive polarity at one of the maximum advance position and the minimum advance position with an angular interval corresponding to the ignition advance width; On the other hand, there is a sensor that generates a voltage of negative polarity, a constant voltage power supply circuit that obtains a constant voltage by the half-wave output on the capacitor charging side of the charging coil, and a calculation capacitor that is gradually charged by the constant voltage of this constant voltage power supply circuit. and a discharging circuit that gradually discharges the charge in the calculation capacitor in intervals of angular intervals corresponding to the ignition advance width; A first reset circuit that instantly discharges the charge in the calculation capacitor and a constant voltage from the constant voltage power supply circuit are used as power supplies, and the voltage of the other polarity generated in the sensor is used to set the reference voltage from the maximum advance angle position. The reference voltage generation circuit that generates the voltage is compared with the terminal voltage of the arithmetic capacitor whose peak voltage decreases as the engine speed increases, and the terminal voltage of the arithmetic capacitor is determined. A comparison switch element conducts when the voltage becomes lower than the reference voltage and applies a gate signal to the ignition thyristor, and after this comparison switch element becomes conductive, the first reset circuit operates to apply the gate signal to the ignition thyristor. A non-contact ignition device for a magnet generator type internal combustion engine, comprising a second reset circuit for resetting the reference voltage generated in the reference voltage generation circuit until the charge in the capacitor is instantaneously discharged. 2. The second reset circuit is connected between the reference voltage generation circuit and the anode of the ignition thyristor, and is configured to reset the reference voltage generated in the reference voltage generation circuit when the ignition thyristor is conductive. The ignition device according to claim 1, comprising a diode. 3. The second reset circuit is connected between the reference voltage generation circuit and the first reset circuit, and resets the reference voltage generated in the reference voltage generation circuit when the first reset circuit is turned on. The ignition device according to claim 1, comprising a diode for. 4. The constant voltage power supply circuit is configured independently for a power supply for the reference voltage generation circuit and a power supply for the calculation capacitor, and the smoothing time constant of the former power supply circuit is set larger than that of the latter. An ignition device according to any one of claims 1 to 3.