JP4666628B2 - Non-contact ignition device for internal combustion engine - Google Patents

Description

  The present invention relates to a non-contact ignition device for an internal combustion engine of a capacitor charge / discharge type that makes it possible to adjust the ignition timing of the internal combustion engine.

  As a conventional contactless ignition device for an internal combustion engine, for example, when a rotor having a magnetic pole rotates, the voltage induced by the exciter coil is charged to the charge / discharge capacitor for ignition, and the charge charged to the charge / discharge capacitor for ignition is Some supply to the ignition coil through a switching element that is switched by a voltage induced by the trigger coil.

  In this contactless ignition device for an internal combustion engine, when the rotational speed of the internal combustion engine, that is, the rotational speed of the rotor is increased, the charging / discharging timing of the charging / discharging capacitor for ignition is accelerated, and finally the rotational speed of the internal combustion engine is increased. There is a case where the engine speed increases beyond the set rotational speed and the internal combustion engine is seized.

  On the other hand, by using a plurality of switching elements and impedance elements that monitor the rotational speed of the internal combustion engine, when the internal combustion engine reaches a set rotational speed, the ignition timing of the ignition charge / discharge capacitor is delayed. There is provided a non-contact ignition device for an internal combustion engine that can prevent over-rotation of the internal combustion engine by electrical control.

  However, the conventional contactless ignition device for an internal combustion engine based on such electrical control uses two or more switching elements and impedance elements, so that it occupies a large space for mounting and has a circuit configuration. It becomes complicated and the cost of the whole apparatus becomes high.

  On the other hand, by adding a time constant circuit for setting the charging / discharging timing of the ignition charging / discharging capacitor to the non-contact ignition device of the internal combustion engine, it is possible to reduce the cost of the internal combustion engine at low cost without complicating the circuit configuration. A non-contact ignition device for an internal combustion engine that prevents rotation is provided.

  In this non-contact ignition device for an internal combustion engine, a rotor having a magnetic pole disposed with a magnet interposed therebetween, a core disposed opposite to the rotor and wound with an exciter coil and a trigger coil, and a positive induced voltage of the exciter coil And an ignition charge / discharge capacitor for charging the ignition coil, and when the positive induced voltage of the trigger coil reaches a predetermined trigger level, the switching element is triggered to supply the charge of the charge / discharge capacitor for ignition to the ignition coil. (For example, refer to Patent Document 1).

Therefore, in this non-contact ignition device for an internal combustion engine, for example, a charge / discharge circuit that charges the positive induced voltage of the trigger coil is provided, and when the internal combustion engine exceeds a set rotational speed, the discharge time constant of the charge / discharge circuit The charging / discharging capacitor for ignition can be prohibited by turning on the switching element based on the switching element. Therefore, the internal combustion engine is in a misfire state, and an increase (overspeed) in the rotational speed of the internal combustion engine can be suppressed.
JP 2001-193618 A

  However, in such a conventional contactless ignition device for an internal combustion engine, the switching element is driven and controlled using an induced voltage of a trigger coil that changes in an analog manner, and therefore the ignition timing of the internal combustion engine is advanced. There was an inconvenience that each control response of the advance angle, retard angle and misfire was delayed.

  In addition, there is a problem in that the controlled ignition timing and misfire timing vary due to variations in the mounting (mainly gap) accuracy between a rotor having a magnet or magnetic pole and a core having an exciter coil or trigger coil.

  The present invention solves such a conventional problem, and the digital response of the pulse obtained from the induced voltage of the trigger coil provides a good control response and is set without being affected by the mounting accuracy between the rotor and the core. Another object of the present invention is to provide a non-contact ignition device for an internal combustion engine that can stably control the operation of the internal combustion engine at the ignition timing, and can reliably prevent the occurrence or reverse rotation of kettin when starting the internal combustion engine.

In order to achieve the above object, a contactless ignition device for an internal combustion engine according to the present invention includes a rotor having two magnetic poles arranged with a magnet interposed therebetween, and an exciter coil and a trigger coil wound around the rotor. And a charge / discharge capacitor for ignition that charges a positive induced voltage of the exciter coil, and is triggered to conduct based on the induced voltage of the trigger coil, and supplies the charge of the charge / discharge capacitor for ignition to the ignition coil. A non-contact ignition device for an internal combustion engine having a switching element that performs first and second positive induced voltages obtained at the trigger coil by rotation of the rotor at the start of the internal combustion engine, and these of the negative induced voltage continuously between the two induced voltages, immediately after the induced voltage of the negative, resulting et on the basis of the second positive induced voltage The drive pulse that, characterized by comprising a control means for driving the switching element.

  With this configuration, the second positive induced voltage obtained immediately after the negative induced voltage obtained in the trigger coil can be specified without misreading, so that it can be obtained from the specified positive induced voltage. When the switching element is driven by the drive pulse, it is possible to avoid the occurrence of ketchin or reverse rotation in the internal combustion engine.

  In the non-contact ignition device for an internal combustion engine according to the present invention, the control means causes the drive pulse to advance or delay the ignition timing of the internal combustion engine with respect to the generation timing of the first positive induced voltage. It is a microcomputer to be controlled.

  With this configuration, under the control of the microcomputer, control of the rotational speed of the internal combustion engine, control of preventing overspeed, control of misfire, and the like can be executed with high accuracy and speed.

  In the non-contact ignition device for an internal combustion engine according to the present invention, the control means starts from the rising timing of the first input pulse obtained based on the first positive induced voltage and the second positive induced voltage. The time until the rise timing of the second input pulse is compared with the rise timing of the second positive input pulse and the time until the rise timing of the first positive input pulse in the next cycle. As the acceleration / deceleration information of the rotational speed of the internal combustion engine, the drive pulse is controlled in a direction to advance or delay the ignition timing of the internal combustion engine according to a control program.

  With this configuration, it is possible to quickly stabilize the idling of the internal combustion engine by digitally correcting the presence / absence of the drive pulse and the time until the output with high accuracy based on the obtained acceleration / deceleration information.

  The present invention has a control means, and the control means obtains the trigger coil of the first and second positive induced voltages obtained by the rotation of the rotor at the start of the internal combustion engine. A drive pulse obtained based on the second positive induced voltage immediately after the negative induced voltage is obtained, and the switching element is driven by the drive pulse, thereby misreading the second positive induced voltage. It is possible to avoid the occurrence of ketchin and reverse rotation in the internal combustion engine when the switching element is driven by the drive pulse.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a partially cutaway front view of a main part configuration of a contactless ignition device for an internal combustion engine according to an embodiment of the present invention. FIG. 2 shows a contactless ignition device for an internal combustion engine according to an embodiment of the present invention. It is a circuit diagram.

In FIG. 1, an exciter coil 1 and a trigger coil 2 constituting a contactless ignition device are wound around both leg portions 8 a and 8 b of a U-shaped core 8. Here, the rotational direction 4 of the rotor 3 to be described later exciter coil 1 is wound around the legs 8a of the opposite, the trigger coil 2 is wound around the leg 8b in the direction of rotation 4.

  Further, the rotor 3 is arranged at a position facing the core 8 so as to be capable of high-speed rotation. The rotor 3 is made of a non-magnetic columnar block such as aluminum, and a pair of magnetic poles 6 and 7 are embedded in the columnar block with a magnet 5 interposed therebetween.

  A part of the magnetic poles 6 and 7 is exposed on the outer periphery of the rotor 3, and can pass through the end surfaces of both the leg portions 8 a and 8 b of the core 8 while the rotor 3 is rotating. Further, the end surfaces of both the leg portions 8 a and 8 b of the core 8 are formed in an arc shape so that a gap (distance) having a constant width can be held with respect to the outer peripheral surface of the rotor 3.

  The size and installation interval of the magnetic poles 6 and 7 and the size and interval of both legs 8a and 8b of the core 8 are set according to the charge / discharge timing and trigger timing of the ignition charge / discharge capacitor described later.

FIG. 2 is a circuit diagram showing a contactless ignition device for the internal combustion engine. In the figure,
The exciter coil 1 is connected in series with a diode 9, an ignition charging / discharging capacitor 10 and a primary coil 11 a of an ignition coil 11, which charge the ignition charging / discharging capacitor 10 with a positive voltage induced by the exciter coil 1. The circuit is configured.

  The ignition charge / discharge capacitor 10 is connected in series with the anode / cathode of the thyristor 12 as a switching element and the primary coil 11a of the ignition coil 11.

  The thyristor 12 and the ignition coil 11 constitute a discharge circuit that discharges the charge of the ignition charge / discharge capacitor 10 to the primary coil 11 a of the ignition coil 11.

  According to this, when the thyristor 12 is triggered and becomes conductive, the charge of the ignition charge / discharge capacitor 10 is discharged to the ignition coil 11. The thyristor 12 also functions to prevent charging of the ignition charge / discharge capacitor 11 by shunting the exciter coil 1 by a trigger.

  Further, a spark plug 13 is connected to the secondary coil 11 b of the ignition coil 11. Further, between the anode and the cathode of the thyristor 12, a backflow prevention diode 14 that also serves to charge a voltage to the ignition charge / discharge capacitor 10 is connected.

  On the other hand, both terminals of the trigger coil 2 are connected to a microcomputer 15 as control means for outputting drive pulses. The output terminal of the microcomputer 15 is connected to the gate of the thyristor 12 for inputting the drive pulse.

  The microcomputer 15 functions to shape the voltage induced by the trigger coil 2, perform digital processing according to a predetermined program, and input the obtained drive pulse to the gate of the thyristor 12.

  Next, the operation of the non-contact ignition device for the internal combustion engine will be described with reference to timing charts of signals at various parts of the circuit shown in FIGS.

  First, when the internal combustion engine operates and the rotor 3 rotates in the direction of arrow 4 in FIG. 1, the trigger coil 2 and the exciter coil 1 on the core 8 facing the rotor 3 induce voltages.

  Among these, the exciter coil 1 applies a positive induced voltage to the charging / discharging capacitor 10 for ignition via the diode 9 and the primary coil 11a of the ignition coil 11. For this reason, the charge / discharge capacitor 10 for ignition is charged. This charged charge is held until the discharge timing described later.

  On the other hand, the trigger coil 2 induces a voltage as shown in FIG. 3A, and the input portion of the computer 15 detects the level of the induced voltage and performs waveform shaping processing, as shown in FIG. 3B. Two positive input pulses p1 and p2 and one positive input pulse p3 as shown in FIG. 3C are respectively extracted and recognized. Here, the input pulse p3 is located between the input pulses p1 and p2.

  First, when starting the internal combustion engine, the microcomputer 15 recognizes positive input pulses p1 and p2 as shown in FIG. 4 (a) (input pulses p1 and p2 shown in FIG. The positive drive pulse p4 as shown in FIG. 4B is generated at the rising timing of the positive input pulse p2.

  This drive pulse p4 is obtained for each period of rotation of the internal combustion engine, that is, rotation of the rotor 3. Further, the drive pulse p4 is applied to the thyristor 12 in order to supply the charge stored in the ignition charge / discharge capacitor 10 to the ignition coil 11 by the positive induced voltage of the exciter coil 1. .

  Accordingly, the thyristor 12 is triggered by the drive pulse p4, and the charged charge accumulated in the ignition charge / discharge capacitor 10 due to the positive induced voltage of the exciter coil 1 passes through the anode and cathode of the thyristor 12 to the ignition coil 11. The primary coil 11a is discharged. Therefore, a high voltage is instantly induced in the secondary coil 11b, sparks are generated in the spark plug 13, and the air-fuel mixture in the cylinder of the internal combustion engine is ignited.

  At the start of the internal combustion engine, the ignition of the air-fuel mixture by the drive pulse p4 is performed for n rotations (for example, 2 to 6 rotations) after the start of the internal combustion engine. As a result, the rotation of the internal combustion engine rises smoothly and gradually increases to the rotation speed of the normal operation mode (main mode).

  Further, the microcomputer 15 regulates the control of the drive pulse p4 in the advance direction or the retard direction, which will be described later, in the start mode of the internal combustion engine.

By the way, at the beginning of such an internal combustion engine, a positive induced voltage in the first cycle (voltage corresponding to the input pulse P2) by the trigger coil 2 is determined depending on the positional relationship between the magnetic poles 6 and 7 and the leg portion 8b immediately before starting. May not be obtained. In this case, the drive pulse P4 is not recognized.

In this case, the microcomputer 15 erroneously recognizes the first input pulse P1 of the next period (second period) as a second input pulse.

  At this time, the second input pulse that has been erroneously recognized triggers the thyristor 12 to erroneously supply the charge of the ignition charge / discharge capacitor 10 to the ignition coil 11. It will cause reverse rotation.

  In the present invention, the input pulse p3 as shown in FIGS. 3 (c) and 5 (b) is between the input pulses p1 and p2 as shown in FIGS. 3 (b) and 5 (a). The microcomputer 15 can recognize the input pulse p2 obtained immediately after the input pulse p3 as a regular pulse.

  Thereby, the microcomputer 15 correctly triggers the thyristor 12 by the drive pulse p4 as shown in FIG. 4B generated based on the recognized input pulse p2, and does not cause the internal combustion engine to generate kettin or reverse rotation. Can be started.

  Therefore, in a mower or the like that houses the internal combustion engine, it is possible to prevent the human body from receiving a large impact by the ketchin immediately after the start of the internal combustion engine.

  Moreover, the microcomputer 15 can grasp | ascertain the rotation speed of an internal combustion engine by measuring the period T of the input pulse p1 as shown to Fig.6 (a). Further, the microcomputer 15 outputs a drive pulse p4 as shown in FIG. 6B based on an external input operation or at an ignition timing predetermined by a program.

The drive pulse p4 is output by signal processing by the microcomputer 15 so as to be located within a time t2 from when the input pulse p1 rises to when the next input pulse P2 is input.

  The drive pulse p4 is input to the gate of the thyristor 12 to trigger it, and becomes a control signal for determining the discharge timing of the ignition charge / discharge capacitor 10, that is, the ignition timing of the internal combustion engine.

  By moving this drive pulse p4 in the advance direction <arrow S direction) or retard direction (arrow R direction) by digital processing by the microcomputer 15 with respect to the input pulse p1, the ignition timing of the internal combustion engine is The user can freely set according to the characteristics of the internal combustion engine.

  The microcomputer 15 obtains the current internal combustion engine speed by measuring the time T, and the ignition is performed at an arbitrarily set time t2 with reference to the first pulse p1 waveform obtained from the trigger coil 2. The charge of the charge / discharge capacitor 10 is discharged.

  Thereby, the ignition timing of the internal combustion engine is controlled. This time t2 (ignition timing) can be arbitrarily set for each engine speed by digital signal processing by a program.

  Therefore, when the computer 15 switches the position of the drive pulse p4 by a program and the speed of the internal combustion engine rises sufficiently and then recognizes a deceleration operation, the speed of the internal combustion engine is preset according to the program. It can be held stably at idling speed. In addition, after that, it is possible to quickly start up to the target rotational speed in a timely manner according to the program.

  In this way, the rotational speed of the internal combustion engine can be set and changed by setting the time t2 in advance fixedly or arbitrarily on the program. As a result, the supply timing of the ignition voltage to the spark plug can be adjusted, and for example, overspeed prevention of the internal combustion engine and rapid response control of the internal combustion engine rotation from the high speed region to the idling region can be easily performed.

  Further, since the rotational speed of the internal combustion engine can be confirmed at time T in FIG. 6A, the rotational speed of the internal combustion engine to be misfired can be set in advance by a program. As a result, when the rotational speed to be misfired is reached, a drive pulse p4 as shown in FIG. 6 (b) is output for one period and is promptly input to the gate of the thyristor 12, whereby the ignition The charging / discharging capacitor 10 can be prevented from being charged, and misfire can be easily and reliably realized.

  In this case, it is possible to restart the internal combustion engine by restarting the ignition after the misfire by setting the return rotation speed from the misfire.

  As described above, in the digital control using the microcomputer, the advance control and retard control of the ignition timing of the internal combustion engine can be easily performed by setting the program, and the ignition is controlled by the variation in the gap between the core 8 and the rotor 3. It is possible to prevent the timing and misfire rotation speed from varying.

Also, as shown in FIG. 7, the time t1 between the rising timings of the input pulses p1 and p2 and the time between the rising timings of the input pulse p2 and the input pulse p1 of the next cycle are measured, and the measurement time difference Acceleration / deceleration is judged from

  Thereby, the presence or absence of the drive pulse and the time t2 until the output are corrected according to the determination result, and measures against Ketchin can be taken.

  This countermeasure against Ketchin is performed based on the determination result of acceleration / deceleration based on the generation timing of the input pulses p1 and p2 within one cycle of the trigger coil output. Can be implemented.

  Thereby, it is possible to avoid a large impact being input to the human body at the time of starting a mower or the like equipped with the internal combustion engine.

  As described above, according to the present embodiment, the control unit 15 is provided, and the first and second positive gains obtained in the trigger coil 1 by the rotation of the rotor 3 when the start of the internal combustion engine is started. Since the switching element 12 is driven by a drive pulse obtained based on the second positive induced voltage immediately after the negative induced voltage obtained in the trigger coil 1 among the induced voltages of With reference to the negative induced voltage obtained in the coil 1, the second positive induced voltage obtained immediately after that can be specified without misreading. For this reason, the drive pulse obtained from the specified positive induced voltage can be specified. Thus, when the switching element 12 is driven, it is possible to avoid the occurrence of ketting or reverse rotation in the internal combustion engine.

  The contactless ignition device for an internal combustion engine according to the present invention has a good control response by digital processing of a pulse obtained from an induced voltage of a trigger coil, and a set ignition timing without being affected by the mounting accuracy between the rotor and the core. Capacitor charge / discharge type that has the effect of stably controlling the internal combustion engine at the same time, and also reliably preventing the occurrence or reverse rotation of kettin at the start of the internal combustion engine, and making it possible to adjust the ignition timing of the internal combustion engine This is useful for a non-contact ignition device for an internal combustion engine.

1 is a partially cutaway front view of a main part configuration of a contactless ignition device for an internal combustion engine according to an embodiment of the present invention. 1 is a circuit diagram showing a contactless ignition device for an internal combustion engine according to an embodiment of the present invention. It is a timing chart which shows the induced voltage and input pulse of the trigger coil in FIG. 2 is a timing chart showing an input pulse and a drive pulse when starting the internal combustion engine in FIG. 1. 2 is a timing chart of input pulses for explaining a method of preventing misreading of input pulses when starting the internal combustion engine in FIG. 1. 4 is a timing chart showing an input pulse and a drive pulse at the time of advance and retard control in the present invention. 3 is a timing chart showing an input pulse and a drive pulse when taking measures against Ketchin in an internal combustion engine according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exciter coil 2 Trigger coil 3 Rotor 5 Magnet 6, 7 Magnetic pole 8 Core 8a, 8b Magnetic pole 10 Ignition charge / discharge capacitor 11 Ignition coil 12 Thyristor (switching element)
13 Spark plug 15 Microcomputer (control means)
17 Misfire switch

Claims (3)

A rotor having two magnetic poles arranged with a magnet interposed therebetween, a core arranged opposite to the rotor and wound with an exciter coil and a trigger coil, and charging / discharging for ignition charging a positive induced voltage of the exciter coil A non-contact ignition device for an internal combustion engine, comprising: a capacitor; and a switching element that is triggered to conduct based on an induced voltage of the trigger coil and supplies a charge of the ignition charge / discharge capacitor to an ignition coil. Of the first and second positive induced voltages obtained in the trigger coil by the rotation of the rotor and the negative induced voltage continuous between these two induced voltages at the start of engine startup, the negative induced voltage Control means for driving the switching element by a driving pulse obtained immediately after the second positive induced voltage is provided. Contactless ignition system for an internal combustion engine, characterized in that the.     2. The microcomputer according to claim 1, wherein the control means is a microcomputer that controls the drive pulse in a direction to advance or delay the ignition timing of the internal combustion engine with respect to the generation timing of the first positive induced voltage. A contactless ignition device for an internal combustion engine as described.   The control means includes a time from the rising timing of the first input pulse to the rising timing of the second input pulse obtained based on the first positive induced voltage and the second positive induced voltage, and the second The positive input pulse rising timing and the time until the first positive input pulse rising timing of the next cycle are compared, and the comparison result is used as acceleration / deceleration information of the rotational speed of the internal combustion engine according to the control program. 2. The contactless ignition device for an internal combustion engine according to claim 1, wherein the drive pulse is controlled in a direction in which the ignition timing of the internal combustion engine is advanced or delayed.

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