JPS6143975Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition device for an internal combustion engine that is driven by the output of a magnetic alternator.

In the conventionally widely used ignition system for internal combustion engines, the ignition power source was an exciter coil installed in a magnetic alternator driven by the engine, but the exciter coil had a large number of turns and required a lot of installation space. It was proposed to eliminate this exciter coil and use the output of the armature coil, which supplies power to loads such as battery charging circuits and lamps, as the ignition power source. Figure 1 shows the configuration of this type of ignition system that has been proposed in the past. In the figure, 1a to 1c are three-phase armature coils installed in a magnetic alternator 1 driven by the engine. These armature coils are connected in a star pattern. 2 is the line voltage of armature coils 1b and 1c
3 is an ignition circuit such as a capacitor discharge type that uses the step-up transformer 2 as an ignition power source, and the ignition circuit 3 is connected to an ignition coil 4 and a primary current control circuit that controls the primary current of the ignition coil. 5 and
The spark plug 6 is connected to the secondary coil of the ignition coil 4. Also, 7 is armature coil 1
A voltage regulator 8 is a load connected to the output end of the voltage regulator 7 for keeping the output voltages of a to 1b approximately within a set range. The voltage regulator 7 is equipped with a switching element such as a thyristor, and when the output voltage exceeds a set value, the switching element is made conductive to short-circuit the phases of the armature coil, thereby adjusting the output voltage. ing. In this type of ignition system, if the output of the armature coil is used as the ignition power source, the power supply voltage at low speeds will be insufficient,
Since the engine cannot be started at low speeds, the phase-to-phase voltage _V1 of the armature coil is boosted by a step-up transformer 2 as shown in the figure, and the output of the step-up transformer 2 drives the ignition circuit 3. According to such a configuration, it is possible to start the engine at low speed, but when the voltage regulator 7 starts adjustment, the phases of the armature coil are short-circuited, so the voltage Vbc applied to the step-up transformer 2 decreases. However, it had the disadvantage that ignition performance was significantly impaired.

An object of the present invention is to provide an ignition device for an internal combustion engine that uses a magnet generator connected to a voltage regulator as an ignition power source and does not impair ignition performance.

The present invention provides a magnetic AC generator connected to a voltage regulator that adjusts the output voltage by short-circuiting at least a part of the output when the output voltage exceeds a set value, and In an ignition system for an internal combustion engine, the ignition device includes a step-up transformer that steps up a voltage applied to the internal combustion engine, and an ignition circuit that uses the step-up transformer as an ignition power source, wherein: (a) the magnetic alternator has a main armature coil and an auxiliary armature coil; (b) the sum of the output of at least a portion of the main armature coil and the output of the auxiliary armature coil is input to the step-up transformer; and (c) the voltage The regulator is connected to the main armature coil.

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

FIG. 2 shows the basic configuration of an embodiment of the present invention. In this embodiment, a magnetic alternator 1 driven by an engine has main armature coils 1a to 1c of phases a to c. 1c and auxiliary armature coil 1'b
It has The main armature coils 1a to 1c are provided so as to induce three-phase voltages having a phase difference of 120 degrees from each other, and are star-connected. The auxiliary armature coil 1'b is provided so as to induce a voltage in the same phase as the b-phase main armature coil 1b, and the auxiliary armature coil 1'b is connected in series to the main armature coil 1b. . Then, _the sum V 3 of the line voltage V ₁ of the b-phase and c-phase main armature coils 1b, 1c and the induced voltage V ₂ of the auxiliary armature coil 1'b is applied to the primary winding 2a of the step-up transformer 2. A voltage regulator 7 is connected to the main armature coils 1a to 1c. The other configurations are the same as the example shown in FIG.

Fig. 3 shows an embodiment that embodies the configuration of Fig. 2, and in this example, the primary current control circuit 5 is a capacitor discharge type circuit. That is, this control circuit has a capacitor _C1 connected in series to the primary coil of the ignition coil 4, and a thyristor S1 is connected in parallel to the series circuit of the capacitor _C1 and the primary coil of the ignition coil. _A resistor is connected between the gate and cathode of the thyristor _S1 .
The resistor _R1 is connected in parallel, and the output of the signal coil 9 is applied to both ends of the resistor _R1 via a diode _D1 . The cathode of a diode _D2 is connected to the connection point between the capacitor _C1 and the thyristor _S1 , and the anode of the diode _D2 is connected to one end of the secondary coil 2b of the step-up transformer 2.
A thyristor _S2 is connected in parallel across both ends of the secondary coil 2b, and a resistor _R2 is connected in parallel between the gate and cathode of this thyristor. A voltage divider circuit consisting of a series circuit of resistors R3 and _R4 is connected in parallel across both ends of the secondary coil _2b via a diode _D3 , and the cathode and anode of a Zener diode _Z1 are connected to the junction of the resistors _R3 and _R4 and the gate of the thyristor _S2 , respectively.

In the control circuit 5, the capacitor C ₁ ,
The thyristor S ₁ , the resistor R ₁ and the diode D ₁ constitute a capacitor charge/discharge control circuit 5a, and the thyristor S ₂ , the resistors R ₂ to R ₄ , the diode D ₃ and the Zener diode Z ₁ constitute a voltage regulator 5b. There is. The signal coil 9 is placed in a signal generator (not shown) and is activated by a thyristor at the engine ignition position.
Induce a signal voltage that triggers _S1 .

_The voltage regulator 7 includes a three-phase full-wave rectifier circuit consisting of diodes D ₁₁ to _{D 16} and thyristors S ₁₁ to _{S 13} whose anodes are connected to the positive output terminals of this rectifier circuit. The _thirteen cathodes are connected to different AC input terminals of the full-wave rectifier circuit. The cathode of a Zener diode Z 10 is connected to the common connection point of the anodes of the thyristors S ₁₁ to _{S 13} , and the anodes of the Zener diode _{Z 10 are} connected to the gates of the thyristors S ₁₁ to _{S 13} through diodes D ₁₇ to D ₁₉ , respectively. There is. The output ends of the main armature coils 1a to 1c of the generator 1 are connected to the above diodes.
It is connected to the AC input terminal of a full-wave rectifier circuit consisting of _D11 to _D16 , and a battery B is connected as a load 8 between the DC output terminals of the full-wave rectifier circuit.

In the above embodiment, the generator 1 is generated by the rotation of the engine.
When induces an alternating voltage, the output rectified by the full-wave rectifier circuit consisting of diodes D ₁₁ to _{D 16} is supplied to battery B, thereby charging battery B. When the engine speed (rpm) increases and the output voltage of the generator exceeds the set value, Zener diode Z ₁₀ becomes conductive and an ignition signal is input to thyristors S ₁₁ to _{S 13} , so these thyristors It is conductive during the period when the anode has a positive potential with respect to the cathode, and short-circuits the phases of the main armature coils 1a to 1c. This suppresses the output voltage of the generator and prevents overvoltage from being applied to the load 8.

On the other hand, the step-up transformer 2 steps up the voltage V 3 which is the sum of the line voltage V ₁ of the b-phase and _c -phase of the main armature winding and the output voltage V ₂ of the auxiliary armature coil 1'b.
Charge the capacitor C ₁ through D ₂ and the primary coil of the ignition coil 4 to the polarity shown. Then, when the signal coil 9 induces a signal voltage at the ignition position, the thyristor S ₁ becomes conductive and discharges the charge in the capacitor C ₁ to the primary coil of the ignition coil 4 . As a result, a high voltage is induced in the secondary coil of the ignition coil 4, and a spark is generated in the ignition plug 6 to ignite the engine. When the engine speed increases and the output voltage of the step-up transformer 2 exceeds a set value, the Zener diode _Z1 becomes conductive and provides an ignition signal to the thyristor _S2 . Therefore, thyristor S ₂ becomes conductive, shorting the portion of the output of step-up transformer 2 that exceeds the set value. This limits the voltage applied to capacitor C ₁ to below the set value, and prevents overvoltage from being applied to capacitor C ₁ .

In the above embodiment, in order to enable the ignition operation, the charging voltage V _c1 of the capacitor C ₁ is required to be 80 V or more. Therefore, the step-up ratio of step-up transformer 2 is
It is set so that the voltage _V3 at the engine starting speed can be increased to 80V or higher. Normally, when starting an engine with a starter motor, the starting rotation speed is 100
~200 rpm, and at 200 rpm, the two-phase line voltage including the auxiliary armature coil is about 5 V.

The output voltage of the auxiliary armature coil 1'b does not reach a value sufficient to operate the ignition circuit when the engine is running at low speed, but it does not reach a value sufficient to operate the ignition circuit when the engine is running at low speed, but it does not reach a value sufficient to operate the ignition circuit when the engine is running at low speed. At a rotation speed of , the setting is such that ignition operation can be performed using only the output voltage of this auxiliary armature coil 1'b.
Therefore, the voltage regulator 7 causes the main armature coil 1 to
Even if the phases a to 1c are short-circuited, the step-up transformer 2
Since a voltage of sufficient magnitude to cause the ignition operation is applied from the auxiliary armature coil 1'b to the auxiliary armature coil 1'b, the ignition operation is performed without any trouble.

FIG. 4 shows the voltages V ₁ to _{V 3} in the above embodiment.
This figure shows an example of the change in engine rotation speed N. In the figure, N ₁ indicates the engine starting rotation speed,
N ₂ indicates the rotational speed at which voltage regulation begins. Further, Vmm indicates the minimum voltage required to perform the ignition operation. Also, Figure 5 shows the capacitor
This shows the change in the terminal voltage V _c1 of C ₁ with respect to the rotation speed N. In the figure, curve a is the main armature winding 1.
Curve b shows the change in terminal voltage V _c1 when using auxiliary armature winding 1'b and auxiliary armature winding 1'b. It shows the change in terminal voltage V _c1 . Further, V _c mm indicates the minimum value of the voltage V _c1 required to perform the ignition operation. flat part of curve a
a ₁ is the voltage V _c1 due to the adjustment operation of the voltage adjustment circuit 5b
A portion a ₁ ' indicated by a broken line indicates a change in the voltage V _c1 when the voltage adjustment circuit 5b is not provided. By providing the voltage adjustment circuit 5b in this way, when the voltage regulator 7 does not perform an adjustment operation in the rotation range until the voltage regulator 7 starts adjustment operation or in the high speed range due to load conditions, Capacitor C ₁
It is possible to prevent overvoltage from being applied to the Note that the output voltage of the step-up transformer is the capacitor C ₁
Of course, the voltage adjustment circuit 5b can be omitted when there is no risk of exceeding the withstand voltage.

The voltage adjustment circuit 5b is not limited to the example shown in FIG _{. 2} , and for example, as _shown in FIG. A circuit may be used in which the diode _D3 is omitted. Also, as shown in Figure 7, the collector is connected to one end of the secondary coil 2b of the transformer 2, and the emitter is connected to a capacitor through a diode _D2 .
A Zener diode _Z1 whose cathode is connected to the base of the transistor Tr connected to _C1 , a diode _D4 whose anode is connected to the anode of the Zener diode _Z1 and whose cathode is connected to the other end of the secondary coil 2b, and a transistor Tr. It can also be configured with a resistor _R5 connected in parallel between the base and collector of the resistor R5. In the circuit of Fig. 7, the secondary coil 2
Transistor Tr through resistor _R5 with induced voltage of b
A base current flows through the transistor, which causes the transistor to
Tr conducts and charges current flows through capacitor _C1 .
When the secondary coil 2b induced voltage exceeds a certain value, the Zener diode _Z1 becomes conductive, and the base potential of the transistor Tr drops to approximately ground potential.
Transistor Tr soon turns off. This prevents overvoltage from being applied to capacitor _C1 .

In the above embodiment, the magnetic alternator 1 has a three-phase main armature winding, but it may have a multi-phase main armature winding of three or more phases, or the main The child winding may be single-phase. FIG. 8 shows an embodiment in which the main armature winding is single-phase. In the figure, 1a is the main armature winding, and 1'b is the auxiliary armature winding. Voltage regulator 7 is diode D ₁₁
A single-phase full-wave rectifier circuit consisting of ~D ₁₄ , thyristors S ₁₁ and S ₁₂ whose anodes are connected to the positive DC output terminal of this rectifier circuit, and whose cathodes are connected to different AC input terminals of the rectifier circuit, and thyristors S ₁₁ , _S12
diodes D ₁₇ and D ₁₈ whose cathodes are connected to the gates of and whose anodes are commonly connected;
Common connection point of anodes of D ₁₇ and D ₁₈ and thyristor
It consists of a Zener diode _Z10 whose anode and cathode are respectively connected to the common connection point of the anodes of _S11 and _S12 . The output of the secondary coil 2b of the transformer 2 is supplied to the ignition circuit 3. The main armature coil 1a is connected between the AC input terminals of the full-wave rectifier circuit of the voltage regulator 7, and the primary coil 2a of the step-up transformer 2 is connected in series with the main armature coil 1a and the auxiliary armature coil 1'b. connected in parallel to both ends of the circuit. The operation of this embodiment is as described above.
This is similar to the embodiment shown in the figure.

As described above, according to the present invention, a magnetic AC generator is provided with a main armature coil and an auxiliary armature coil, and the sum of the output of at least a part of the main armature coil and the output of the auxiliary armature coil is generated. is supplied to the step-up transformer for the ignition power supply, and the voltage regulator is connected only to the main armature coil, so when adjusting the voltage, the ignition operation can be performed without any problem with the output of the auxiliary armature coil, and the ignition performance at high speeds is improved. can be prevented from decreasing.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing a conventional example, Figure 2 is a block diagram showing the basic configuration of an embodiment of the present invention, and Figure 3 is a block diagram showing the basic configuration of an embodiment of the present invention.
The figure is a connection diagram showing an embodiment embodying each part of Fig. 2, and Fig. 4 is a diagram showing an example of the characteristics of the voltage obtained from the magnetic AC generator with respect to the rotation speed in the embodiment of Fig. 3. Fig. 5 is a diagram showing the characteristics of the terminal voltage of capacitor _C1 with respect to the rotation speed of the ignition circuit of the embodiment shown in Fig. 3, and Figs. 6 and 7 are used for the ignition circuit of the embodiment shown in Fig. 3, respectively. FIG. 8 is a connection diagram showing different modifications of the voltage regulating circuit. FIG. 8 is a connection diagram showing another embodiment of the present invention. 1... Magnetic AC generator, 1a to 1c... Main armature coil, 1'b... Auxiliary armature coil, 2...
...Step-up transformer, 3... Ignition circuit, 4... Ignition coil, 5... Primary current control circuit, 6... Spark plug, 7... Voltage regulator, 8... Load, 9... Signal coil, D ₁ , _D11 to _D19 ...Diode, _S1 ,
S ₁₁ , ~S ₁₃ ... Thyristor, Z ₁₀ ... Zener diode, C ₁ ... Capacitor.

Claims (1)

[Scope of utility model registration request] A magnetic AC generator connected to a voltage regulator that adjusts the output voltage by short-circuiting at least a part of the output when the output voltage exceeds a set value, and boosting the voltage obtained from the generator. In the ignition system for an internal combustion engine, the magnetic alternator includes a step-up transformer, and an ignition circuit that uses the step-up transformer as an ignition power source. An ignition for an internal combustion engine, characterized in that the sum of the output of at least a portion of the coil and the output of the auxiliary armature coil is input to the step-up transformer, and the voltage regulator is connected to the main armature coil. Device.