JPH0530989B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a capacitor discharge type non-contact ignition device for an internal combustion engine.

[Conventional technology]

Conventionally, as described in Japanese Unexamined Patent Publication No. 57-131864, the generated output of a capacitor charging coil of a magnet generator is short-circuited by a short-circuiting semiconductor switching element, and when this switching element is cut off, the generated output of a capacitor charging coil is short-circuited. It is known that the capacitor is charged by a charging coil having a large wire diameter and a small number of turns by charging the capacitor with a high voltage.

[Problem to be solved by the invention]

However, when the above-mentioned conventional method is applied to a multi-pole magnet generator with four or more poles, for example, a high voltage is induced every time a half-wave output on the capacitor charging side is generated in the capacitor charging coil, and the capacitor As a result, the charging voltage of the capacitor becomes too high, which poses a problem in terms of the withstand voltage of each element.

Therefore, in order to solve the above problems, the present invention
When the charging voltage of the capacitor exceeds a predetermined value, the semiconductor switching element for cutoff control which short-circuits the control signal of the short-circuiting semiconductor switching element is made conductive, thereby reducing the induced high voltage after the capacitor charging voltage exceeds the predetermined value. The purpose is to prevent overcharging of a capacitor with a simple configuration.

[Means to solve the problem]

Therefore, in the present invention, the capacitor charging coil of the magnet generator is electrically connected to the half-wave output of one of the charging coils by applying it as a control signal.
A sufficient short-circuit current flows through the short-circuit semiconductor switching element that substantially shorts this half-wave output, the cut-off control semiconductor switching element that short-circuits the control signal of this short-circuit semiconductor switching element, and the short-circuit semiconductor switching element. a first detection circuit for making the cut-off control semiconductor switching element conductive when the short-circuiting semiconductor switching element is turned off; a capacitor that is charged by a high voltage induced in the charging coil when the short-circuiting semiconductor switching element is cut off; an ignition coil having a primary coil and a secondary coil;
The charging voltage of the capacitor is detected, and when this voltage exceeds a predetermined value, the cutoff control semiconductor switching element is made conductive to prevent a short circuit of one half-wave output of the charging coil due to the conduction of the short circuit semiconductor switching element. a second detection circuit for blocking the ignition, an ignition signal generation circuit that generates an ignition signal at the ignition timing, and an ignition signal from the ignition signal generation circuit to conduct the electric charge in the capacitor to one of the ignition coils. A non-contact ignition device for an internal combustion engine is provided, which includes an ignition semiconductor switching element for supplying ignition to a secondary coil, and an ignition plug connected to a secondary coil of the ignition coil.

[Effect]

As a result, when the charging voltage of the capacitor exceeds a predetermined value, it is detected by the second detection circuit and the semiconductor switching element for cut-off control is made conductive. This prevents short-circuiting of the wave output and stops the operation of the inductive booster circuit.

〔Effect of the invention〕

As described above, according to the present invention, generation of induced high voltage after the charging voltage of the capacitor exceeds a predetermined value can be prevented without short-circuiting the induced output of the capacitor charging coil. It is possible to prevent overcharging of a capacitor with a simple configuration, by effectively utilizing the element to stop the operation of the inductive booster circuit, and without causing excessive heat generation of the short-circuit semiconductor switching element or the capacitor charging coil. There is an excellent effect that can be done.

The present invention will be described below with reference to embodiments shown in the drawings.

First, in Fig. 1, 1 is a capacitor charging coil of a multi-pole magnet generator, for example, the wire diameter is 0.3 to 1.0.
mm, and the number of turns is 200 to 600 times. 2 is a timing sensor that generates an output signal at a reference position, 4 and 5 are voltage dividing resistors connected in series between the terminals of capacitor charging coil 1, and the voltage dividing point a is connected to the base of transistor 6. . This transistor 6 is connected between the base and emitter of a transistor 8. 7 is the base resistance of transistor 8, 19 is a capacitor connected in parallel with resistor 5, and this capacitor 19 and resistors 4 and 5
configuring the detection circuit. Further, the transistor 6 constitutes a semiconductor switching element for cutoff control that short-circuits the base of the transistor 8, and the transistor 8 constitutes a semiconductor switching element for short-circuiting that short-circuits the forward output of the coil 1. 13 is an ignition capacitor, 9 and 10 are voltage dividing resistors connected to the capacitor 13, and the voltage dividing point b is connected to the base of the transistor 6 via a diode 11. 12 is a discharge blocking diode, 14 is a timing sensor 2
15 is a diode for DC arcing, 16 is an ignition coil, 16a
is its primary coil, and 16b is its secondary coil. Reference numeral 17 denotes an ignition plug, and 18 an ignition thyristor which serves as a semiconductor switching element for ignition.When an ignition signal from the timing sensor 2 is applied to the gate, the ignition thyristor becomes conductive and transfers the charge in the capacitor 13 to the primary of the ignition coil 16. It is supplied to the coil 16a. 20 is a diode for blocking backflow.

Next, the structure of the magnet generator used in this example 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 denotes a ring-shaped stator core fixed to the side wall of the internal combustion engine, and twelve protrusions 32a to 32 are formed at equal intervals on the outer periphery of the stator core. Reference numeral 33 denotes a lamp load coil which is wound around each of the ten protrusions 32c to 32 and connected in series with each other, and serves as a power source for a load such as a lamp. A boss 34 is fixed to the crankshaft of the internal combustion engine by a bottle (not shown), and the rotor 30 is fixed to the boss 34 via a rivet (not shown). 35 is at the outer periphery of the rotor 30,
An ignition signal timing sensor fixed to the side wall of the internal combustion engine includes a permanent magnet 35a magnetized in the radial direction;
It consists of a core 35b fixed to this permanent magnet 35a and a sensor coil 2 wound around the core 35b. 3
6 is a protrusion made of a magnetic material provided on the outer periphery of the rotor 30, and a core 35 is located at a position facing this protrusion 36.
b is provided, and an output voltage shown in FIG. 3e is generated in the sensor coil 2 due to a change in magnetic flux due to the core 35b and the protrusion 36 facing each other. The capacitor charging coil 1 has two protrusions 32a, 3
2b and are connected in series with each other, and by the rotation of the main magnet 31, a no-load AC voltage of 6 cycles is generated in the capacitor charging coil 1 as shown in FIG. 3a for each rotation of the rotor of the magnet generator.

Now, when charging coil 1 begins to generate half-wave output in the direction of the arrow (positive direction) in Figure 1, base current flows to transistor 8 in the circuit from coil 1 to resistor 7 to base/emitter of transistor 8 to ground. ,
The collector and emitter of this transistor 8 are electrically connected, and the output of the coil 1 is short-circuited. 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), transistor 6 becomes conductive and short-circuits between the base and emitter of transistor 8.
OFF, and the short circuit current is abruptly cut off. At this time, a large induced voltage is generated in the coil 1 as shown by the solid line in FIG. 3b, and this high voltage causes the capacitor 13 to be
The circuit from capacitor 13 to diode 15 to ground charges the battery sufficiently as shown by the solid or broken lines in Figure 3c.

Here, if the high voltage induced in the charging coil 1 is relatively low, such as when the engine speed is low, the voltage charged to the capacitor 13 will not exceed the set value, so the solid line in FIG. As shown by the solid line in FIG. 3c, the capacitor 13 is charged multiple times by the high voltage of the charging coil 1 which is generated six times per rotation of the magnet generator.

On the other hand, when the engine rotates at medium to high speeds, the high voltage induced in the charging coil 1 becomes relatively high, and as shown by the broken line in FIG. When the charging voltage of the capacitor 13 exceeds the set value due to high voltage, the potential at the voltage dividing point of the voltage dividing resistors 9 and 10 becomes a value sufficient to make the transistor 6 conductive. and short-circuit the base of transistor 8. As a result, even if the third and subsequent positive half-wave outputs occur in the charging coil 1, the transistor 8 will not conduct, and a high voltage will not be induced in the charging coil 1. Therefore, the capacitor 13 will not be charged from then on. This prevents overcharging of the capacitor 13. At this time, the output voltage of the charging coil 1, the charging voltage of the capacitor 13, the transistor 8
The short-circuit currents are shown by the dashed lines in Fig. 3b, c, and d, respectively.

Furthermore, by reducing the number of ON/OFF operations of the transistor 8 when the high voltage induced in the charging coil 1 is relatively high, such as when the engine is running at high speed, the heat generation of the transistor 8 can be suppressed. Thermal runaway can be prevented.

When the ignition timing comes, the thyristor 18 is activated by the ignition signal shown in FIG. 3e from the timing sensor 2.
conducts, and transfers the charge in the capacitor 13 to the capacitor 13 → thyristor 18 → ground → ignition coil 1
A sudden discharge is caused by the circuit of the primary coil 16a of No. 6,
A high voltage is applied to the secondary coil 16b of the ignition coil 16, and an ignition spark is generated at the ignition plug 17.

In addition, with respect to the embodiment shown in FIG. 1, resistors 9, 10,
Instead of the diode 11, a second detection circuit consisting of a series circuit of a Zener diode and a resistor is directly connected.
It may be inserted between the charging side terminal of the capacitor 13 and point a in FIG. In this way, leakage of the capacitor charging charge to the resistor 9 side at low speeds can be eliminated, and a drop in the charging voltage of the capacitor 13 can be prevented.

FIG. 4 shows another embodiment of the device of the present invention, in which the diode 14 is different from the embodiment shown in FIG.
is connected in series with the timing coil 2, a transistor 22 is connected in parallel with the gate and cathode of the thyristor 18, and a resistor 2 is connected between the base of the transistor 22 and the charging side terminal of the capacitor 13.
6 and a diode 21 are connected, and a series circuit of each diode 23a to 23c and each switch 24a to 24c is connected between the connection point of this diode 21 and a resistor 26 and the ground. . For example, in a two-wheeled vehicle, these switches 24a to 24c include one that turns on when the side stand is retracted, one that turns on when the transmission is in the neutral position, and one that turns on when the clutch is disengaged. It is used.

According to this embodiment, each switch 24a-24
If any of c is ON, transistor 2
Since the base current of timing coil 2 is bypassed through each of the diodes 23a to 23c and each switch 24a to 24c, the transistor 22 remains OFF, and the ignition signal of the timing coil 2 is passed through the diode 14 to the thyristor 18. The voltage is applied to the gate, and the ignition operation is performed in the same manner as in the embodiment shown in FIG.

Here, all of the switches 24a to 24c are
If it is OFF, the charge in the capacitor 13 is applied to the base of the transistor 22 via the resistor 26 and the diode 21, making the transistor 22 conductive and bypassing the gate signal of the thyristor 18. As a result, the ignition signal is no longer applied to the thyristor 18, the ignition operation is stopped, and the engine is stopped. At this time, several half-wave outputs on the capacitor charging side are generated in the capacitor charging coil 1 until the engine stops, but when the charging voltage of the capacitor 13 exceeds a predetermined value, the transistor 8 turns on.
Since it is no longer turned off, the capacitor 13 will not be overcharged.

In this embodiment of FIG.
Instead of connecting the transistor 25 in parallel with the gate circuit of the thyristor 18, the transistor 25 can also be connected in series with the gate circuit of the thyristor 18, as shown by the broken line. In this case, the resistor 26 and diode 21 can be omitted.

In addition, in FIG. 4, the timing coil 27
On the other hand, as shown by the broken line, the engine stop manual switch 27 may be connected in parallel.

As shown in FIG. 4, in a device that blocks the application of the ignition signal to the gate of the thyristor 18 to disable ignition and stop the engine, or in a device that prevents the engine from running, there are two poles. Even when a magnet generator is used, overvoltage of the capacitor 13 can be prevented when the engine is stopped.

[Brief explanation of the drawing]

Fig. 1 is an electric circuit diagram showing one 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, and Fig. 3 is an explanation of the operation of the device shown in Fig. 1. FIG. 4 is an electric circuit diagram showing another embodiment of the device of the present invention. 1... Capacitor charging coil, 2... Timing sensor forming the ignition signal generation circuit, 4, 5,
19...Voltage dividing resistor and capacitor constituting the first detection circuit, 6...Transistor constituting the semiconductor switching element for cut-off control, 8...Thyristor forming the semiconductor switching element for short circuiting, 9,1
0, 11... Voltage dividing resistor and diode constituting the second detection circuit, 13... Capacitor, 16... Ignition coil, 16a... Primary coil, 16b... 2
Next coil, 17... Ignition plug, 18... Ignition thyristor forming a semiconductor switching element for ignition.

Claims (1)

[Claims] 1. A short-circuit device that conducts the capacitor charging coil of the magnet generator and the half-wave output of one of the charging coils by applying it as a control signal, thereby substantially short-circuiting the half-wave output. A semiconductor switching element, a semiconductor switching element for cutoff control that shorts the control signal of the semiconductor switching element for shorting, and a semiconductor switching element for cutoff control that conducts when a short circuit current is sufficiently flowing through the semiconductor switching element for shorting. a first detection circuit for detecting a short-circuit, a capacitor charged by a high voltage induced in the charging coil when the shorting semiconductor switching element is cut off, a primary coil and a second detection circuit;
The charging voltage of the ignition coil having a secondary coil and the capacitor is detected, and when this voltage exceeds a predetermined value, the cutoff control semiconductor switching element is made conductive, and the charging coil is turned on by the conduction of the short circuit semiconductor switching element. A second detection circuit for preventing a short circuit of one of the half-wave outputs, an ignition signal generation circuit that generates an ignition signal at the ignition timing, and an ignition signal from this ignition signal generation circuit conducts the capacitor. A non-contact ignition device for an internal combustion engine, comprising an ignition semiconductor switching element for supplying charging charge to a primary coil of the ignition coil, and an ignition plug connected to a secondary coil of the ignition coil. 2. The non-contact ignition device for an internal combustion engine according to claim 1, wherein the magnet generator is a multi-pole magnet generator with four or more poles.