JP3101124B2 - Magneto ignition device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto ignition device using a high-pressure magneto system as an engine ignition system, and more particularly to a DC power supply for converting an induced current flowing through a primary coil into a DC current.

[0002]

2. Description of the Related Art In general, a general-purpose, small-sized engine employs a high-pressure magneto system excellent in high-speed rotation performance as an ignition system. This high-pressure magneto system
A magnet type alternator integrated with an ignition coil and an interrupter. The contacts are closed and a short-circuit current flows through the primary coil. A high-voltage is generated on the flywheel side, and the most typical one is a flywheel magneto type using a rotor as a flywheel, an example of which is shown in FIG. Here, FIG. 5 is a waveform diagram of the voltage induced in the primary coil of the flywheel magneto ignition device shown in FIG. 4, and FIG. 6 is an explanatory diagram showing operation waveforms of the flywheel magneto ignition device shown in FIG. The operation will be described below with reference to these drawings.

In these figures, a flywheel magneto ignition device (hereinafter referred to as a magneto ignition device) 60
Has a primary coil (lighting coil) 61 and a secondary coil (ignition coil) 62 both of which are ignition coils. The high-voltage current induced in the secondary coil 62 is sent to an ignition plug 73. Causing a spark discharge in the spark gap,
Ignition of the mixture in the combustion chamber of the engine. The magneto ignition device 60 includes a voltage generator 60a having primary and secondary coils 61 and 62, and a controller 60b for controlling the voltage generator 60a. Voltage generator 60a
The semiconductor switch 63 is an npn-type transistor which is installed in parallel with the primary coil 61 together with the primary and secondary coils 61 and 62 and to which a voltage induced in the primary coil 61 is applied. 1 connected to the base
It has a base resistor 64 to which the voltage induced in the next coil 61 is applied, and a switching element 65 such as a thyristor connected in series with the base resistor 64. In the voltage generating unit 60a, 1 primary coil 61 is influenced by the rotating magnetic field of the magnet 72 of the flywheel 71 which rotates in conjunction with the crankshaft, the forward voltage V _F and the reverse direction of the forward direction with respect to the semiconductor switch 63 And the reverse voltage V _R is generated in an alternating manner. Forward voltage V generated in primary coil 61
_F is applied to the semiconductor switch 63 and the base resistor 64 to reversely bias the collector and the emitter of the semiconductor switch 63. When the switching element 65 is in an open state, a high potential is applied to the base of the semiconductor switch 63 as compared with the emitter side, so that a forward bias is applied between the base and the emitter, and the semiconductor switch 63 becomes conductive. Therefore, a large collector current I _C flows between the collector and the emitter of the semiconductor switch 63. Further, the forward voltage V _F which is generated in the primary coil 61 is also applied to the control unit 60b, at time t _10, when the forward voltage V _F is the maximum value, the control unit 60b will detect this voltage The switching element 65 is turned on. Thereby, the base resistance 6
4 current flows, because the base voltage of the semiconductor switch 63 is reduced, the semiconductor switch 63 is turned off, the collector current I _C is interrupted. Due to this sudden current interruption, a high voltage is generated on the secondary coil 62 side, and the high voltage is applied to the spark plug 73 to perform discharge ignition.

The reverse voltage V generated in the primary coil 61
_R is consumed as heat in the process of flowing from the emitter side to the collector side of the semiconductor switch 63.

[0005] In recent years, magneto-ignition devices 60 having various characteristics have been developed in response to demands from the market of small engines.

For example, a high output can be obtained by the electronic advance and retard of the ignition timing.

[0007] Prevention of overspeeding: When the number of rotations of the engine becomes equal to or more than a predetermined number of rotations, a warning is issued to prevent overrunning of the engine.

[0008] In addition to the control of the ignition timing, a device that controls a mechanism such as a throttle valve of a carburetor by a microcomputer to achieve high efficiency operation of the engine with higher output and higher fuel efficiency. Is desired.

[0009]

However, the magneto ignition device 60 is an AC power supply circuit based on a magnetic flux change between a magnet 72 and a primary coil 61 installed on a flywheel 71 which rotates in association with the crankshaft of the engine. There is a problem that there is no DC power supply necessary for controlling the ignition timing and the throttle valve of the carburetor. Therefore, in the magneto igniter 60, the development of a DC current supply from an external DC power supply or a DC power supply circuit incorporated in the device to form a DC current from an AC voltage has been developed. Are not provided that meet the requirements of

[0010] In view of the above problems, the problem to be solved by the present invention is to make the most of the circuit elements of a conventional magneto igniter, to be easily incorporated into the magneto igniter, and to achieve high efficiency. An object of the present invention is to realize a magneto ignition device including a DC current supply unit capable of outputting a DC current.

[0011]

Means for Solving the Problems In order to solve the above-mentioned problems, a first means adopted in the present invention is a magneto-ignition device comprising a primary coil that generates an induced voltage by rotation of a magnet, A first semiconductor switch that interrupts a forward current flowing through a secondary coil, a secondary coil that generates a high voltage by interrupting the forward current, a control input of the first semiconductor switch, and a high reverse current that flows through the primary coil. A direct current which is provided between the first semiconductor switch and a charge path via a pn junction of the first semiconductor switch when a reverse current is generated, and is capable of discharging the stored charge when a reverse current is not generated. And a current supply unit. Here, the DC current supply unit includes a first capacitor for storing charge when a reverse current is generated, and a first capacitor for storing a charge when a reverse current is not generated.
A second capacitance into which accumulated charge of the capacitance of
It is preferable to have a second semiconductor switch that is switched at the time of discharging the first capacitance and reduces the resistance of the discharge path.

A second means adopted in the present invention is a primary coil which generates an induced voltage by rotation of a magnet;
A first semiconductor switch that interrupts a forward current flowing through the primary coil, a secondary coil that generates a high voltage by interrupting the forward current, and a high potential side and a low potential side of a reverse current flowing through the primary coil. A first capacitor for storing charge when a reverse current is generated, a second capacitor for storing charge stored in the first capacitor by discharge when no reverse current is generated, and a first capacitor. And a second semiconductor switch which is switched at the time of discharging to lower the resistance of the discharge path.

[0013]

In the magneto-ignition device according to the present invention employing the first means, a forward voltage (forward voltage) and a reverse voltage (reverse voltage) are induced in the primary coil by rotation of the magnet. At the time of occurrence, a forward current or a reverse current flows. When the first semiconductor switch suddenly cuts off the forward current when the forward current occurs, a high voltage for the ignition plug is induced on the side of the secondary coil triggered by the cutoff of the forward current. When a reverse current is generated, a DC current supply unit provided between the control input of the first semiconductor switch and the high potential side of the reverse current accumulates the charge due to the reverse current, while the reverse current flows. Disappears, the accumulated charge is discharged to generate a DC current. Here, the direct current supply unit uses the pn junction of the first semiconductor switch as a charging path for accumulating the electric charge of the reverse current. When a forward current occurs, the pn junction of the first semiconductor switch is connected to the forward current. To prevent the forward current from flowing into the DC current supply unit. Therefore, a dedicated rectifying element such as a diode for preventing the current from being mixed with the forward current and the reverse current in the DC current supply unit is not required, and the configuration can be simplified. Here, the DC current supply unit accumulates a charge when a reverse current occurs, a second capacitance into which the accumulated charge of the first capacitance flows by discharge when the reverse current does not occur, and a first capacitance. A second semiconductor switch that is switched during discharging of the capacitance to reduce the resistance of the discharge path thereof, the charge loss during the commutation of the charge from the first capacitance to the second capacitance is reduced. Since the charge can be reduced, the charge amount of the second capacity can be increased, and the power supply capacity can be increased. For example, in order to charge the first capacitor with the reverse current generated in the primary coil, it is necessary to connect a resistor to one side and set the potential of the first capacitor by this voltage drop. However, since this resistor is provided on the discharge path of the first capacity, a large power loss is caused when the first capacity is discharged. Therefore, the resistance is changed from the first capacity to the second capacity. It is desirable to be bypassed during the commutation of the electric charge. Thus, the first
A second semiconductor switch is provided in a discharge path having a capacity of
Since the resistance between the first capacitor and the second capacitor can be reduced,
And the amount of DC current that can be supplied can be increased. Therefore, for example, in the case where the DC current generated in the second capacitor is supplied to a microcomputer used as a control unit, the power consumption of the microcomputer can be increased. It is possible to control various mechanisms such as ignition timing and a carburetor throttle valve.

Further, in the magneto ignition device according to the present invention in which the above-mentioned second means is employed, when the reverse current is generated, the first capacitor for storing the charge of the reverse current is used as the control input of the first semiconductor switch. It is provided not only between the high voltage side and the high voltage side of the reverse current but also between the high voltage side and the low voltage side of the reverse current, so that the power supply capacity can be increased similarly to the first means.

[0015]

Next, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows the configuration of a magneto ignition device according to a first embodiment of the present invention. In the figure, a magneto ignition device 10 of the present embodiment controls a voltage generation unit 10a that generates an induced voltage associated with a rotation operation of a magnet 32 of a flywheel 31 that rotates in association with a crankshaft, and controls the voltage generation unit 10a. And a control unit 10b that performs
It has a DC current supply unit 20 that forms a DC current from an AC voltage generated in the voltage generation unit 10a and supplies the DC current to the control unit 10b.

In the magneto ignition device 10 of the present embodiment, the configuration of the voltage generator 10a is the same as that of the conventional magneto ignition device 60 shown in FIG. It has a primary coil 11 for generating a reverse current in a direction opposite to the forward current, and a secondary coil 12 for inducing an ignition voltage for the ignition plug 33 by interrupting the forward current generated in the primary coil 11. doing. Also, a first semiconductor switch 13 which is an npn-type transistor connected in parallel with the primary coil 11 and capable of conducting a forward current, and a voltage connected to the base of the first semiconductor switch 13 and induced in the primary coil 11 And a switching element 15 as a thyristor connected in series with the base resistor 14.

Here, the primary coil 11 and the secondary coil 12
Are both formed as ignition coils.

The control section 10b gives a potential to the gate of the switching element 15 so that the first semiconductor switch 13 can be controlled. That is,
Since the base resistor 14 is connected to the base of the first semiconductor switch 13, when the switching element 15 is in an open state, a forward voltage (forward voltage) generated in the primary coil 11 is applied to the base resistor 14. And the base voltage is the first
Exceeds the threshold voltage of the semiconductor switch 13 of FIG.
Are turned on. Here, when the forward voltage generated in the primary coil 11 increases and takes the maximum value, the switching element 15 becomes conductive. Thereby , the first
Since the base voltage of the semiconductor switch 13 decreases, the first semiconductor switch 13 is turned off, and the forward current flowing through the primary coil 11 is cut off. Therefore, a high voltage is generated on the secondary coil 12 side, and this high voltage is
3 is applied to ignite.

Further, the magneto ignition device 10 of the present embodiment includes:
Further, a charge of a reverse current due to a reverse voltage (reverse voltage) generated in the primary coil 11 of the voltage generating unit 10a is accumulated,
A DC current supply unit 20 that supplies a DC current to the control unit 10b is provided. This DC current supply unit 20 is connected to the base- emitter of the first semiconductor switch 13 of the voltage generation unit 10a.
A jitter installed resistance between 23 and connected to the the resistor 23 in series, a first capacitor 21 that is placed between the emitter side and base side of the first semiconductor switch 13, a resistor 23 in parallel , A diode 25 that controls the current to the first capacitor 21, a second capacitor 22 that is installed in parallel with the first capacitor 21, and a diode that controls the current to the second capacitor 22. 26.

The DC current supply unit 20 includes a voltage generation unit 1
The charge of the reverse current due to the reverse voltage generated in the primary coil 11a is stored in the first and second capacitors 21 and 22. That is, the reverse current due to the reverse voltage generated in the primary coil 11 is caused by the one end 11a of the primary coil 11, the diode 25, the first capacitor 21, the base-collector junction of the first semiconductor switch 13, and the primary coil. 11 through the charging path composed of the other end 11 b of the first capacitor 21.
Charge. Here, the voltage drop of the resistor 23 connected in series to the first capacitor 21 causes the resistance 23 of the first capacitor 21 to change.
Is set to a low potential. And 1
When the voltage generated in the next coil 11 changes from the reverse direction to the forward direction or becomes zero and the reverse current disappears, the discharge of the first capacitor 21 is started, and the first capacitor 21, the diode 26, and the second capacitor 21 are discharged. Capacitor 22, resistor 23 and first capacitor 21
The second capacitor 22 is charged through a charging path consisting of:
The second capacitor 22 is connected to the control unit 10b so that the charge of the first capacitor 21 accumulated by the reverse voltage generated in the primary coil 11 is commutated and supplied to the control unit 10b. Has become. The forward current generated by the forward voltage generated in the primary coil 11 flows from the collector side to the emitter side as the collector current of the first semiconductor switch 13 and does not flow to the first capacitor 21. Capacity 2
The first capacitor 21 can stably transfer the charge to the second capacitor 22 without providing a rectifying element such as a diode for preventing the forward current from flowing into the first capacitor 21.

As described above, the magneto ignition device 10 of the present embodiment
In, the charge of the reverse current due to the reverse voltage generated in the primary coil 11 can be stored in the first and second capacitors 21 and 22 and supplied to the control unit 10b as a DC current. Therefore, the control unit 10b can control the ignition timing and the throttle valve of the carburetor by incorporating a microcomputer or the like in addition to the gate control of the switching element 15.

Embodiment 2 FIG. 2 shows the configuration of a magneto ignition device according to Embodiment 2 of the present invention. The configuration and operation of the magneto igniter of the present embodiment are substantially the same as those of the magneto igniter 10 of the first embodiment, and common parts are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 2, the magneto ignition device 4 of this embodiment
0 is that the DC current supply unit 20
In the configuration of the discharge path of the electric charge from the first capacitor 21 to the second capacitor 22. That is, the low-potential side of the first and second capacitors 21 and 22 is connected to the magneto ignition device 40 of the present embodiment, and the second semiconductor switch 28 as an npn-type transistor provided in parallel with the resistor 23. And a base resistor 24 for supplying a base current of the second semiconductor switch 28.
have.

In the DC current supply section 20 having such a configuration, the DC current supply section 20 is provided on the discharge path of the first capacitor 21 and is connected to the first capacitor 21.
The resistor 23 required for charging the first capacitor 21 can be bypassed during the commutation of the electric charge from the first capacitor 21 to the second capacitor 22. Since the resistance can be reduced, the power loss of the commutated charges can be reduced. That is, when the reverse current disappears and the first capacitor 21 starts discharging, the first capacitor 21
Causes a forward bias between the base and the emitter of the second semiconductor switch 28, so that the second semiconductor switch 28 is turned on. Accordingly, the charge discharged from the first capacitor 21 is diverted to the second capacitor 22 by bypassing the resistor 23 through a discharge path including the diode 26, the second capacitor 22, and the second semiconductor switch 28. . As described above, in the DC current supply unit 20 of the magneto ignition device 40 of the present embodiment, the second semiconductor switch 28 provided in parallel with the resistor 23 is turned on when the first capacitor 21 is discharged, and the first semiconductor switch 28 is turned on. Since the resistance of the discharge path from the capacitor 21 to the second capacitor 22 is reduced, power is not consumed in the resistor 23, so that the transfer of charge from the first capacitor 21 to the second capacitor 22 is prevented. It can be done effectively.

Third Embodiment FIG. 3 shows the configuration of a magneto ignition device according to a third embodiment of the present invention. This embodiment is a modification of the second embodiment, and the configuration and operation thereof are substantially the same as those of the magneto ignition device 40 of the second embodiment. Is omitted.

In FIG. 3, the magneto ignition device 5 of this embodiment
Reference numeral 0 indicates that the low potential side of the first capacitor 21 is connected to the collector side of the first semiconductor switch 13, and a diode 27 for preventing a forward current from flowing into the first capacitor 21 is provided between the low potential side and the first capacitor 21. Have been. As described above, in the magneto ignition device 50 of the present embodiment, when the reverse current is generated, the first capacitor 21 that stores the charge is connected to the high potential side and the low potential side of the reverse current, that is, the first semiconductor switch 13. Even if it is installed between the emitter side and the collector side, the DC current can be generated with high efficiency with a simple configuration by providing the diode 27.

[0028]

As described above, in the magneto ignition device according to the present invention, the DC current supply for storing the reverse current charge generated in the primary coil by the rotation of the magnet and discharging the stored charge as a DC current. It has a unit. The DC current supply unit is provided between the control input of the first semiconductor switch and the high potential side of the reverse current, and serves as a charging path for accumulating the reverse current charge.
By using the junction, when a forward current is generated, it is possible to prevent the forward current from flowing into the DC current supply unit, so that a dedicated rectifying element or the like is not required, and the configuration can be simplified. Therefore, according to the present invention, it is possible to generate a direct current necessary for controlling the ignition timing of the engine, the throttle valve of the carburetor, etc. from the reverse current which is not involved in the supply of the ignition voltage for the spark plug, DC power supply unit (DC current supply unit) with a simple configuration built into the device
It can be.

In the DC current supply section, a first capacitor for storing a charge of a reverse current and a second capacitor capable of supplying a charge diverted from the first capacitor as a DC current are provided. In the case where the second semiconductor switch having a low resistance is provided, the loss of charge at the time of transfer of charge from the first capacitor to the second capacitor can be reduced. For example, a resistor provided on the charge path of the first capacitor required to charge the first capacitor with the reverse current charge generated in the primary coil causes a large power loss when the first capacitor is discharged. Invite you. Here, at the time of discharging the first capacitance, the second semiconductor switch is used to switch the discharging path of the first capacitance and to bypass the resistor, thereby reducing the loss of charge to the second capacitance. Therefore, the charge amount of the second capacity can be increased, and the power supply capacity can be increased. Therefore,
Since the power consumption of the microcomputer that can be incorporated in the control unit can be increased, it is possible to control various mechanisms such as an ignition timing and a carburetor throttle valve in a general-purpose engine without an external power supply.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of a magneto ignition device according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration of a magneto ignition device according to a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a configuration of a magneto ignition device according to a third embodiment of the present invention.

FIG. 4 is a circuit diagram showing an example of a configuration of a conventional magneto ignition device.

5 is a waveform diagram showing a voltage waveform induced in a primary coil of the magneto ignition device shown in FIG.

6 is an explanatory diagram showing operation waveforms of the magneto ignition device shown in FIG.

[Explanation of symbols]

 10, 40, 50 ... magneto ignition device 10a ... voltage generation unit 10b ... control unit 11 ... primary coil 12 ... secondary coil 13 ... first semiconductor switch 14 ... Base resistor 15 Switching element 20 DC current supply unit 21 First capacitor 22 Second capacitor 23 Resistor 24 Base resistor 25, 26, 27 ..Diode 28 ... second semiconductor switch 31 ... flywheel 32 ... magnet 33 ... spark plug

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F02P 1/08

Claims (3)

(57) [Claims] 1. A primary coil for generating an induced voltage by rotation of a magnet, a first semiconductor switch for interrupting a forward current flowing through the primary coil, and a secondary coil for generating a high voltage by interrupting the forward current Between the control input of the first semiconductor switch and the high potential side of the reverse current flowing through the primary coil, and when the reverse current occurs, charging the first semiconductor switch via a pn junction. A magnet current igniter, comprising: a DC current supply unit that accumulates electric charges by a path and discharges the accumulated electric charges when the reverse current is not generated. 2. The first DC current supply unit according to claim 1, wherein the DC current supply unit stores the charge when the reverse current occurs.
And a second capacitor into which the stored charge of the first capacitor flows by discharging when the reverse current is not generated; and
A second semiconductor switch which is switched during the discharging of the capacity of the second semiconductor to reduce the resistance of the discharge path. 3. A primary coil for generating an induced voltage by rotation of a magnet, a first semiconductor switch for interrupting a forward current flowing through the primary coil, and a secondary coil for generating a high voltage by interrupting the forward current. A first capacitor that is provided between a high potential side and a low potential side of a reverse current flowing through the primary coil, and stores a charge when the reverse current is generated; A second capacitor into which the accumulated charge of the first capacitance flows by the discharge, and a second semiconductor switch which is switched at the time of the discharge of the first capacitance to reduce the resistance of the discharge path. Magneto ignition device.