JPH04330378A - Non-contact ignition device for internal combustion engine - Google Patents

Abstract

PURPOSE:To perform excellent multiple charge of a capacitor by using a capacitor charging coil having a large wire size and the reduced number of windings. CONSTITUTION:A generating output from a capacitor charge coil 1 of a multipole magnet generator is short-circuited by a transistor 8. When a short- circuit current is increased to a value higher than a given value, the transistor 8 is disconnected to effect multiple charge of a capacitor 13 by means of a high voltage induced by the charge coil 1. A thyrister 18 is energized by means of an ignition signal generated from an ignition signal generating circuit 14 at an ignition timing, and the charged electric charge of the capacitor 13 is discharged through a primary coil 16a of an ignition coil 16.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor discharge type non-contact ignition device for internal combustion engines.

0002

[Prior Art] Conventionally, in this type of device, in order to make the charging voltage of the capacitor almost uniform from low to high engine speeds, the charging source for the capacitor was a thin wire with a large number of turns, mainly during low speed rotation. It consisted of a low-speed coil that charged the capacitor, and a high-speed coil with a thick wire diameter and a small number of turns that charged the capacitor mainly during high-speed rotation, and the capacitor was directly charged by the output of these two coils.

0003

However, the above-mentioned conventional method requires (1) two coils with different specifications for low-speed and high-speed use as the capacitor charging coil, resulting in a complicated structure; Become. Moreover, the dimensions become larger, and the physique of the magnet generator becomes larger.

(2) The charging coil for low speed is a thin wire (wire diameter 0.
13~0.16mm) (number of turns 3000~70
00 times), the workability is poor and quality problems are likely to occur.

(3) If an attempt is made to increase the secondary voltage at low speeds, that is, the capacitor voltage, the secondary voltage at medium and high speeds, that is, the capacitor voltage will increase, resulting in insufficient heat resistance of the ignition coil or semiconductor element, etc. There's a problem.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a non-contact ignition device for an internal combustion engine that can efficiently charge a capacitor multiple times using a capacitor charging coil having a large wire diameter and a small number of turns.

[0007]

[Means for Solving the Problems] Therefore, the present invention provides a capacitor charging coil of a magnet generator that is driven by an internal combustion engine and generates a plurality of cycles of alternating current output per revolution of the internal combustion engine, and a capacitor charging coil that is connected in parallel with the charging coil. a short-circuiting semiconductor switching element for substantially short-circuiting one half-wave output of the charging coil; and a short-circuiting semiconductor switching element for cutting off the short-circuiting semiconductor switching element when a sufficient short-circuit current is flowing through the shorting semiconductor switching element. A cutoff control circuit;
A capacitor that is charged by a high voltage induced in the charging coil when the shorting semiconductor switching element is cut off, an ignition coil having a primary coil and a secondary coil, and the charging coil and the shorting semiconductor switching element are connected to each other. a discharge blocking diode inserted between the parallel circuit and the capacitor to prevent the charge charged in the capacitor from being discharged via the charging coil or the shorting semiconductor switching element; and an AC output of the charging coil. a timing sensor that generates an output signal at a reference position every time the AC output of the charging coil occurs for multiple cycles; and a timing sensor that generates an ignition signal at the ignition timing every time the AC output of the charging coil occurs for multiple cycles using the output signal of this timing sensor as input. an ignition signal generation circuit, an ignition semiconductor switching element that is electrically connected by an ignition signal from the ignition signal generation circuit to supply the charge charged in the capacitor to the primary coil of the ignition coil; The present invention provides a non-contact ignition device for an internal combustion engine, which includes a spark plug connected to a secondary coil.

[0008]

[Example] First, in Fig. 1, reference numeral 1 denotes a capacitor charging coil of a magnet generator, for example, a wire diameter of 0.3 to 1.0 and a number of turns of 200 to 600 is used. In this machine, the wire diameter is about 4 times thicker and the number of turns is about 1/10th that of the conventional one. 2 is a timing sensor that generates an output signal at the reference position, 3 is a shorting diode that shorts the reverse output of charging coil 1, and 4 and 5 are voltage dividing resistors connected in series between the terminals of capacitor charging coil 1. , its voltage dividing point a is connected to the gate of the thyristor 6. This thyristor 6 is connected between the base and emitter of a transistor 8. 7 is a base resistor of the transistor 8, and this resistor 7, the thyristor 6, and the resistors 4 and 5 constitute a cut-off control circuit. Further, the transistor 8 serves as a short-circuiting semiconductor switching element that short-circuits the forward output of the coil 1. 9 and 10 are voltage dividing resistors connected in series between the terminals of the coil 1, whose voltage dividing point b is connected to the gate of the thyristor 11, so that the voltage generated in the coil 1 after the transistor 8 is turned off exceeds the set value. If this happens, it will be short-circuited. This thyristor 11 and resistors 9 and 10
A high voltage responsive short circuit is constructed. 12 is a discharge blocking diode, 13 is an ignition capacitor, and 14 uses the positive output of the charging coil 1 as a power source, and uses the output signal of the timing sensor 2 as input to electronically determine the ignition timing and generate an ignition signal. This is a known electronic ignition signal generation circuit. 15 is a DC arc diode, 16 is an ignition coil, 16a is its primary coil, and 16b is its secondary coil. 17 is an ignition plug; 18 is an ignition thyristor which is a semiconductor switching element for ignition; when the ignition signal from the ignition signal generation circuit 14 is applied to the gate, conduction occurs, and the charge in the capacitor 13 is transferred to the ignition coil 16;
It is supplied to the primary coil 16a of. 19 is a resistance.

Next, the structure of the magnet generator used in this embodiment will be explained. In FIG. 2, 30 is a bowl-shaped rotor, and 31 is a ring-shaped main magnet fixed to the inner peripheral surface of the rotor 30, which is magnetized with 12 N and S poles alternately arranged at equal intervals as shown in the figure. Reference numeral 32 designates a ring-shaped stator core fixed to the side wall of the internal combustion engine, and has 12 protrusions 32a to 32a on its outer periphery.
32l are formed at equal intervals. Reference numeral 33 denotes a lamp load coil which is wound around each of the ten protrusions 32c to 32l and connected in series with each other, and serves as a power source for a load such as a lamp. 34 is a boss fixed to the crankshaft of the internal combustion engine by a bolt (not shown), and the rotor 30 is fixed to the boss 34 via a rivet (not shown). 35 is an ignition signal timing sensor fixed to the side wall of the internal combustion engine on the outer periphery of the rotor 30, and includes a permanent magnet 35a magnetized in the radial direction, a core 35b fixed to the permanent magnet 35a, and a sensor wound around the core 35b. It consists of coil 2. Reference numeral 36 denotes a projection made of a magnetic material provided on the outer circumference of the rotor 30. A core 35b is provided at a position facing this projection 36, and a change in magnetic flux caused by the core 35b and projection 36 facing each other causes the sensor coil to Figure 3 (f
), a narrow output voltage of one cycle is generated per one revolution of the rotor 30. Capacitor charging coil 1
are wound around the two protrusions 32a and 32b and connected in series with each other, and due to the rotation of the main magnet 31, the capacitor charging coil 1 receives 6 cycles of no-load per rotation of the rotor of the magnet generator, as shown in FIG. 3(a). AC voltage is generated.

Now, the charging coil 1 is placed in the direction of the solid arrow in FIG.
When a half-wave output (in the positive direction) starts to be generated, base current flows to transistor 8 in the circuit of coil 1 → resistor 7 → base-emitter of transistor 8 → ground, and conduction occurs between the collector and emitter of transistor 8, and the coil The output of 1 is shorted. At this time, as the short-circuit current of transistor 8 increases as shown in FIG. Rise. When this voltage reaches a set value (for example, a voltage value corresponding to a short circuit current of 0.5 to 4 A), the thyristor 6 becomes conductive, shorting the base and emitter of the transistor 8, so that the collector and emitter of the transistor 8 are turned off. , the short circuit current is suddenly cut off. At this time, a large induced voltage is generated in the coil 1, as shown by the solid line in Fig. 3(b), and this high voltage causes the capacitor 13 to be connected in the circuit of the coil 1 → diode 12 → capacitor 13 → diode 15 → ground. 3(c)
Charge the battery sufficiently as shown by the solid line. Furthermore, when the induced voltage exceeds a set value (for example, 100 to 300 V), the voltage at the connection point b of the voltage divider circuit made up of resistors 9 and 10 increases,
Thyristor 11 conducts, shorting the terminals of coil 1,
This prevents overvoltage and prevents heat generation in the resistors 4 and 7 due to the current flowing due to the no-load generated voltage generated after the induced voltage, and further suppresses the current value of the diode 3 in the opposite direction to a small value due to the armature reaction. On the other hand, the reverse direction output of coil 1 (
The broken line arrow in Fig. 1) is short-circuited by diode 3 to prevent excessive reverse voltage from being applied to thyristors 6, 11 and transistor 8, and also causes a reverse current to flow through coil 1, so that the armature reaction causes the following The magnitude of the positive direction output that occurs subsequently is suppressed, and the current in the coil 1 (solid line in FIG. 3(e)) and the current in the thyristor 6 are reduced. This makes it possible to prevent the coil 1 from generating heat and to downsize the thyristor 6, diode 3, and resistors 4, 5, and 7.

Furthermore, when the ignition timing is reached, the output of the timing sensor 2 shown in FIG. 3(f) causes the ignition signal generation circuit 1 to
The electronically determined ignition signal of thyristor 1
8 becomes conductive, and transfers the charge in capacitor 13 to capacitor 1.
3 -> Thyristor 18 -> Earth -> Rapid discharge is caused in the circuit of the primary coil 16a of the ignition coil 16, a high voltage is obtained in the secondary coil 16b of the ignition coil 16, and an ignition spark is generated at the ignition plug 17. Here, the broken lines in FIGS. 3(b), (c), and (e) are for the case without the resistors 9 and 10 and the thyristor 11, and the broken lines in FIGS. 3(b), (c), and (
3(e), the coil current increases as the induced voltage of the coil 1 and the charging voltage of the capacitor 13 increase, and the two-dot chain line in FIG.
0, without thyristor 11 and diode 3,
The positive voltage after the induced voltage in the coil 1 disappears is about twice as high as when the diode 3 is present, and this leads to an increase in the current capacity of the resistors 4, 5, and 7 and the thyristor 6.

FIG. 4 is an electric circuit diagram showing another embodiment of the present invention. In contrast to the embodiment shown in FIG. The output charges the capacitor 25 of the constant voltage power supply for the ignition signal generation circuit via the diodes 24 and 3. Here, the voltage of the capacitor 25 is controlled to a set value by a constant voltage circuit including a Zener diode 21, a resistor 22, and a thyristor 23.

In each of the embodiments described above, an electronic ignition signal generation circuit 14 was used which electronically determines the ignition timing by inputting the output signal of the timing sensor 2.
An ignition signal generation circuit that directly applies the output signal of the timing sensor 2 as a control signal to the thyristor 18 may be used.

[0014]

As described above, in the present invention, one half-wave output of the capacitor charging coil, which is driven by the internal combustion engine and generates multiple cycles of AC output per revolution of the internal combustion engine, is substantially short-circuited. a short-circuit semiconductor switching element; and a cutoff control circuit for cutting off the short-circuit semiconductor switching element when a short-circuit current due to a half-wave output on the capacitor charging side of the charging coil is sufficiently flowing through the short-circuit semiconductor switching element. It prevents the charge in the capacitor from being discharged through the capacitor charging coil and the short-circuiting semiconductor switching element, and charges the capacitor when the short-circuiting semiconductor switching element is cut off. Since it includes an ignition signal generation circuit that generates an ignition signal at the ignition timing every time the AC output of the capacitor charging coil is generated a plurality of times, there are excellent effects as described below.

(1) Conventionally, a capacitor charging coil required two coils with different specifications: a thin wire coil with a large number of turns and a thick wire coil with a small number of turns, but now only a thick wire coil with a small number of turns is used. The structure is simple and the body size can be reduced.

(2) The degree of freedom in setting the capacitor voltage and secondary voltage is large, sufficient ignition performance can be obtained from low speeds, and starting performance can be improved. (3) Since there is no need to use thin wire as a capacitor charging coil, quality problems can be resolved.

(4) Before the ignition signal is generated at the ignition timing, the short-circuiting semiconductor switching element is turned on and off multiple times by multiple cycles of AC output generated in the capacitor charging coil, so that high voltage is applied to the capacitor charging coil multiple times. is induced, and the discharge of the capacitor's charge is blocked by the discharge blocking diode until the ignition semiconductor switching element is made conductive by the ignition signal. Therefore, the capacitor is multi-charged by the high voltage induced in the capacitor charging coil. As a result, ignition performance can be further improved.

[Brief explanation of drawings]

FIG. 1 is an electrical circuit diagram showing an embodiment of the device of the present invention.

FIG. 2 is a bottom view showing a magnet generator applied to the device shown in FIG. 1;

FIG. 3 is a waveform chart of various parts for explaining the operation of the device shown in FIG. 1;

FIG. 4 is an electrical circuit diagram showing another embodiment of the device of the present invention.

[Explanation of symbols]

1 Capacitor charging coil 2 Timing sensor 3 Shorting diodes 4, 5, 6, 7 Voltage dividing resistor that constitutes the cutoff control circuit,
Thyristor, base resistor 8 Thyristor 9, 10, 11 forming a short circuit semiconductor switching element Voltage dividing resistor and thyristor 12 forming a high voltage response short circuit Discharge blocking diode 13 Capacitor 14 Electronic ignition signal generation circuit 16 Ignition coil 16a 1 Secondary coil 16b Secondary coil 17 Spark plug 18 Ignition thyristor forming a semiconductor switching element for ignition

Claims (1)

[Claims] A capacitor charging coil of a magnet generator that is driven by an internal combustion engine and generates multiple cycles of alternating current output per revolution of the internal combustion engine is connected in parallel with this charging coil, and the half-wave output of one of the charging coils is substantially a short-circuiting semiconductor switching element that short-circuits the short-circuiting semiconductor switching element; a cutoff control circuit that interrupts the short-circuiting semiconductor switching element when a sufficient short-circuit current flows through the short-circuiting semiconductor switching element; between a capacitor charged by a high voltage induced in the charging coil, an ignition coil having a primary coil and a secondary coil, a parallel circuit of the charging coil and the shorting semiconductor switching element, and the capacitor; A discharge blocking diode is inserted to prevent the charge of the capacitor from being discharged through the charging coil and the shorting semiconductor switching element, and a reference position is inserted every time the AC output of the charging coil occurs for multiple cycles. a timing sensor that generates an output signal at the ignition timing; an ignition signal generation circuit that receives the output signal of the timing sensor as an input and generates an ignition signal at the ignition timing every time the AC output of the charging coil is generated for a plurality of cycles; an ignition semiconductor switching element that is made conductive by an ignition signal from a signal generation circuit to supply the charged charge of the capacitor to the primary coil of the ignition coil; and an ignition plug connected to the secondary coil of the ignition coil. A non-contact ignition device for internal combustion engines.