JPS60219465A - Engine speed controller for internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve starting performance through improving ignitability at cold start by sensing the engine speed to switch, by means of a neutral signal, the control circuit which controls generation of high voltage for spark plugs. CONSTITUTION:A charge coil 1 supplies an ignition circuit B with energy for spark dischanging, while a pulser coil 2 generates plus and minus pulses for ignition signal to be transmitted to a signal supply circuit C. The ignition unit A has a control circuit D which detects the engine speed to control high voltage generation at the ignition circuit B. This control circuit D opens and closes getting an assigned voltage from the charge coil 1 through a power supply circuit E and a nutral signal actuated by nutral switch F. Thus the ignitability at cold start can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotational speed control device for an internal combustion engine that controls the rotational speed at a neutral shift position.

(Prior Art) As is well known, in internal combustion engines such as the outboard 41, when the shift position is neutral, the throttle disposed in the carburetor interposed in the intake passage is regulated so as not to open by a link mechanism, etc. There is a method that restricts the fuel supplied to the combustion chamber, thereby preventing the rotational speed from increasing to a predetermined value, thereby preventing abnormal combustion and fogging of the spark plug.

By the way, in this configuration where the throttle opening is regulated during neutral, thereby reducing the air-fuel mixture and lowering the rotational speed, even if fuel is supplied from the choke mechanism during a cold engine start, the throttle opening will not reach the predetermined level. limited to the range of For this reason, there is a problem in that a rich mixture cannot be sufficiently supplied to the combustion chamber, and starting performance cannot be improved.

In addition, when in neutral with mechanical means such as a link mechanism,
In a structure that restricts the throttle opening to prevent an excessive increase in rotational speed, it may be difficult to secure enough space for installation near the engine.

(Purpose of the invention) This invention was made in view of these circumstances.

The rotational speed in neutral is controlled by electronically misfiring the ignition circuit instead of using a mechanical link mechanism to regulate the throttle opening, making it possible to supply a rich air-fuel mixture at startup. It is an object of the present invention to provide a rotational speed control device for an internal combustion engine that improves startability, has a simple structure, and facilitates the layout of the vicinity of the engine.

(Structure of the Invention) In order to achieve the above object, the present invention includes an ignition circuit that obtains a high voltage for ignition to an ignition coil, and a signal supply circuit that supplies an ignition signal to the ignition circuit in synchronization with the rotation of the engine. The internal combustion engine is characterized in that it includes a control circuit that detects the rotational speed of the engine and regulates the generation of the high voltage, and that the control circuit is opened and closed in response to a neutral signal.

(Example) Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a schematic diagram of a rotational speed control device for an internal combustion engine, and FIG. 2 is a specific circuit diagram thereof.

In this embodiment, the present invention is applied to a capacitor discharge type ignition device A.

The charging coil 1 and the pulsar coil 2 are provided on a flywheel magneto (not shown), and the charging coil 1 supplies energy for ignition and discharge to the ignition circuit B, and the pulsar coil 2 generates positive and negative pulses as ignition signals to the signal supply circuit C. supply

As shown in Fig. 2, the ignition circuit B generates a high voltage for ignition in the ignition coil 3, and includes a series circuit of a diode 4 and a discharge capacitor 5 forming a rectifier circuit, and a connection between the two. It consists of a thyristor 6 as a semiconductor switching element and a diode 7.8, which can be short-circuited and inserted between a point and ground.

That is, one end of the charging coil l is connected to the diode 4, and the output of the charging coil l is charged to the capacitor 5 via the diode 4. The ignition coil 3 is a part of the coil 3
The connection point between a and the secondary coil 3b is connected to the capacitor 5, the other end of the secondary coil 3a is grounded, and the secondary coil 3a is connected to the capacitor 5.
The other end of b is grounded via a spark plug 9.

The iristor 6 indicated by H:f is ignited when the ignition signal IJ is received from the signal supply circuit C at its gate, and the charge in the capacitor 5 is discharged through the thyristor 6 and a part of the coil 3a of the ignition coil 3, and the secondary The spark plug 7 is configured to generate an ignition spark using the high voltage generated in the coil 3b.

Furthermore, the tie 7 of No. 111 is installed between the charging coil 1 and the diode 1' 4 with the 7 no F side grounded, so that the negative half wave of the alternating current generated in the coil 1 is released. It has become. Further, a diode 8 is provided between the capacitor 5 and the ignition coil 3 with its cathode side grounded, and this diode 8 is used to release the current that charges the capacitor 5 to the opposite polarity when the capacitor 5 is discharged. It is something.

1. As shown in FIG. 2, the signal supply circuit C has a rectifying diode IO connected to the pulser coil 2, and a waveform shaping circuit 11 connected in series to the diode 10. The waveform shaping circuit 11 is a capacitor 12
and a resistor 13 connected in parallel to this, improving the X-integrity of the pulse waveform and ensuring the operation of the thyristor 6.

As shown in Fig. 181, the ignition device WA has an engine circuit.
The ignition circuit B is equipped with a control circuit that detects the rotation speed and regulates the generation of high voltage, and this control circuit is supplied with a predetermined voltage by the 11 source circuit E from the charging coil 1, and is connected to the neutral switch F. It opens and closes in response to the neutral signal generated by the operation of the

As shown in FIG. 2, the control circuit is connected to the ignition circuit B, and detects the rotational speed of the engine when the engine is in neutral and short-circuits the ignition circuit B. When this control circuit is used, for example, in an outboard motor, each constituent electronic ice f- provided on a wiring board is partially molded with synthetic resin or the like to avoid salt damage.

The misfire thyristor 14, which is a semiconductor switching element that constitutes a part of this control circuit, is inserted between one output end of the charging coil 1 and the connection point between the TIO 1ζ7 and the ground so that it can be short-circuited. ing.

Further, the FV conversion circuit 15 and the waveform shaping circuit 16, which form part of the control circuit, detect the rotational speed of the engine and apply a gate trigger voltage to the misfire thyristor 14.

This waveform shaping circuit 16 is connected to one output end of the balsa coil 2, and shapes the output waveform of the pulse voltage generated by the pulsar coil 2 to ensure that the FV conversion circuit 15 operates reliably. I try to do that. and,
This FV conversion circuit 15 converts the frequency of pulses input during a predetermined time into voltage under the manual condition of the neutral number from the neutral switch F or the timer signal from the timer circuit 17, and converts the frequency of pulses inputted during a predetermined time into voltage. The misfire thyristor 14 is configured to be ignited by outputting a cathode pressure to the gate of the thyristor 14.

The timer circuit 17 is connected to an oil amount detection circuit that includes a thermoswitch 18 that detects the temperature of the engine, and a warning lamp 19 and warning buzzer 20 that detects the low level of oil in the tank. Therefore, type circuit 17
When the thermo switch 18 is closed when O7<Heat, or when the oil amount detection circuit is activated, the FV adjustment circuit 15 is activated only for a set time.

The power supply circuit E is connected to the other output terminal of the charging coil l, and the waveform shaping circuit 16 and the F conversion circuit 15
A predetermined direct current is supplied to the timer circuit 17. Furthermore, a guide 21 is connected between this charging coil 1 and the power supply circuit E with its anode grounded, so that the negative half wave of the alternating current generated in the charging coil 1 is released. There is.

The neutral switch F has a neutral contact fl that supplies a neutral signal to the FV conversion circuit 15 when in neutral, and a starter contact f2 that connects the main switch G and a starter relay 23 that operates the starter motor 22 when starting. .

The main switch G also has an off contact gl, an on contact g2 that operates the oil amount detection circuit, and a starting contact g3 that operates the starter motor 22. When the starting contact g3 of the main switch G is connected to operate the neutral switch F, and the starter contact f2 is connected, the starter relay 23 is energized. This causes starter motor 2
2 is connected to a battery 24 via a contact point of a starter relay 23 and is driven to start the engine.

Next, the operation of this embodiment will be explained.

The main switch G is connected to the starting contact g3, and under this condition, the neutral switch F is operated to close the starter contact f2 and the neutral contact fl. As a result, a neutral signal is input to the FV conversion circuit 15 of the control circuit,
When the starter relay 23 is activated, the contacts are closed, and the starter motor 22 is driven to rotate the crankshaft.

When starting the engine, if the engine is cold, the throttle of the carburetor (not shown) is opened and a choke mechanism is activated to supply a rich air-fuel mixture to the combustion chamber of the engine to improve ignitability.

As a result, alternating current is generated from charging coil L, and ignition circuit B
The capacitor 5 is charged through the diode 4. At the same time, the balsa coil 2 periodically generates a noggle, and the diode 10 of the signal supply circuit C and the waveform shaping circuit 1
1, the ignition signal is sent to the gate of thyristor 6.

Therefore, the thyristor 6 is fired, and the charge in the capacitor 5 is discharged through the thyristor 6 and the secondary coil 3a of the ignition coil 3, and at this time, a primary current flows through the secondary coil 3a. Therefore, a high voltage is induced in the secondary coil 3b,
The spark plug 9 generates an ignition spark to ignite.

If the rotational speed of the engine is below the set value, the balsa coil 2 passes through the waveform shaping circuit 16 to the FV adjusting circuit 1.
5, the frequency of the pulser voltage input during a predetermined period of time is low. Therefore, no trigger voltage is generated from the FV conversion circuit 15, and the misfire thyristor 14 does not fire, so the ignition circuit B is not short-circuited by the control circuit.

On the other hand, when this engine is started, it is in neutral, and the cycle interval of the pulse voltage generated by the pulser coil 2 becomes faster, the frequency of pulses input during a predetermined time increases, and the FV conversion circuit 15 voltage is reached. Then, a gate trigger voltage is output to the gate of the misfire thyristor 14, and the misfire thyristor 14 is ignited to cause the ignition circuit B to fire.
By short-circuiting the capacitor 5, the output of the charging coil 1 is prevented from being charged to the capacitor 5, thereby regulating the generation of high voltage.

Therefore, the spark plug 9 misfires and the rotational speed decreases.

When the rotation speed decreases to a predetermined rotation speed, the gate trigger voltage is applied to the misfire thyristor 14 from the FV conversion circuit 15.
Since the misfire thyristor 14 is turned off and the output of the charging coil 1 is charged to the capacitor 5, a high voltage is induced in the secondary coil 3b as before, and the spark plug 1 spark plug 9 is not output.
generates an ignition spark to ignite and maintain a predetermined rotational speed.

In addition, in normal operating conditions, when the main switch G is connected to the ON contact g2 that activates the oil amount detection circuit, the alarm lamp 19 and alarm buzzer 20 are activated if the oil in the tank is below a predetermined value. At the same time, the timer circuit 17 is activated. Furthermore, this timer circuit 17
When the engine heats up/down, the thermo switch 18
is activated and outputs a timer signal to the FV conversion circuit 15, and the FV conversion circuit 15 is activated to output a gate trigger voltage to reduce the rotation speed of the engine for the time set by the timer circuit 17. .

FIG. 2 is a circuit diagram showing another embodiment, in which a misfire thyristor 14 as a semiconductor switching element constituting a part of the control circuit is connected to the output end of the pulsar coil 2 and the signal supply circuit C. A short-circuit is inserted between the connection point of the diode 19 forming a part and the ground. and,
The output end of the pulsar coil 2 is connected to the waveform shaping circuit 11 via a diode 25, so that the negative pulsar voltage generated from the pulsar coil 2 is input to the waveform shaping circuit 16.

Therefore, the positive pulser voltage generated from the pulser coil 2 provides the gate trigger voltage to the thyristor 6 from the signal supply circuit C. When the rotational speed exceeds a predetermined value under the condition that the neutral signal or the timer signal is input, the FV variable power circuit 15 operates to ignite the gate trigger voltage to the misfire thyristor 14. As a result, the signal supply circuit C is short-circuited, and the supply of the gate trigger voltage to the thyristor 6 of the first ignition circuit B is stopped, so that the thyristor 6 no longer fires, and since the charge charged in the capacitor 5 is not discharged, the ignition coil 9, the generation of high voltage is regulated. Therefore, one spark plug 9 misfires and the rotational speed is controlled.

In an internal combustion engine, if the throttle is suddenly opened, the air-fuel mixture becomes lean, so even in engines that supply fuel with an accelerator pump installed in the carburetor, if the rotational speed reaches 1, the control circuit will cause the spark plug to misfire. It may also be controlled by causing the

(Effects of the Invention) As described above, the present invention includes a control circuit for detecting one revolution speed in the ignition circuit of an internal combustion engine such as an outboard motor and regulating the high voltage generated in the ignition circuit. Since it is opened and closed by the neutral signal, the throttle opening is increased in the neutral position when starting a cold engine, and a rich air-fuel mixture is supplied, improving ignition performance. When the set rotation speed is reached, a misfire occurs and the rotation speed is maintained at the set value.
No abnormal combustion or fogging of spark plugs will occur.

Generally speaking, compared to a system that mechanically regulates the opening of the throttle, since it is controlled by electronic means, the structure is simple and the layout near the engine is easy.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention, FIG. 2 is a specific circuit diagram of this embodiment, and FIG. 3 is a specific circuit diagram showing still another embodiment. A... Ignition device B... Ignition circuit C... Signal supply circuit D... Control circuit E... Parameter source circuit F... Neutral switch 6... Thyristor 14... For ignition Thyristor 15
...FV irregular circuit 16...Waveform shaping circuit 17.
...Timer circuit diagram 1

Claims (1)

[Claims] (1) Detecting the rotational speed of one engine in an internal combustion engine equipped with an ignition circuit that obtains a high voltage for ignition to the ignition coil, and a signal supply circuit that supplies ignition signal to the ignition circuit in synchronization with the rotation of the engine. A rotational speed control device for an internal combustion engine, comprising a control circuit for regulating the generation of the high voltage, and the control circuit is opened and closed by a neutral signal.