JP3481695B2 - Start control circuit for contactless ignition system for internal combustion engine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting control circuit in a non-contact ignition device for an internal combustion engine for ensuring safety at the time of starting a vehicle equipped with the internal combustion engine.

[0002]

2. Description of the Related Art As typical examples of conventional techniques for ensuring safety at the time of starting a vehicle equipped with an internal combustion engine, Japanese Utility Model Publication No. 58-173531 and Japanese Utility Model Publication No. 4-302 are known.
There is a technique disclosed in Japanese Patent Publication No. 69.

The prior art of Japanese Utility Model Laid-Open No. 58-173531 is provided with a switch which is turned on at the connection position of the work clutch, and the start contact of the main switch and the relay are connected through this switch to establish the connection position of the work clutch. When the main switch is set to the start position, the relay is activated to activate the engine stop unit, so that the engine cannot be started unless the clutch is disengaged to ensure safety. The clutch can be operated as usual.

The prior art of Japanese Utility Model Laid-Open No. 4-30269 has a centrifugal clutch for intermittently transmitting power according to the engine speed, and the engine speed is equal to or higher than the speed at which the centrifugal clutch is connected. The coil is connected to the power generation section of the engine, and the detection switch that turns on when the throttle moves and turns off when the throttle moves to a position where the engine speed is below the speed that disconnects the centrifugal clutch. The relay switch is connected in series to ensure safety by preventing the engine from starting unless the throttle is in the position to disconnect the centrifugal clutch, and operate the throttle normally after the engine starts. You can

As described above, in the above-mentioned prior art, since the engine can be started on condition that the clutch is in the disengaged state, there is a danger that the vehicle suddenly starts or the work function part suddenly operates. Can be prevented and high safety can be demonstrated.

[0006]

However, in the former case of the above-mentioned prior art, a relay and an engine stop unit are required in addition to the clutch switch that is disengaged due to the disengagement of the clutch, and the clutch switch is used for the engine. It is necessary to connect to the main switch, and for connecting and assembling the clutch switch, it is necessary to provide a dedicated circuit component part in a part of the engine stop unit,
There is a problem that the whole structure becomes complicated and the mounting becomes troublesome.

Further, in the latter of the above-mentioned prior arts, in addition to the detection switch connected to the throttle, a relay coil connected to the power generation part of the engine is required, and the application target is provided with a centrifugal clutch. However, there is a problem in that the connection structure is complicated and it cannot be applied to a general clutch having a general clutch which is intermittently operated when necessary.

Further, in the above-mentioned prior art, since a relay switch is required as one of the constituent parts,
There has been a problem that the miniaturization of the whole is greatly restricted and a dedicated portion for mounting the relay switch is required, so that the space and location for mounting are severely restricted.

Therefore, the present invention was devised to solve the above-mentioned problems in the prior art, and adapts the action of the clutch switch on / off to the operation of the internal combustion engine to the operating conditions of the internal combustion engine. It is an object of the present invention to secure the safety at the time of starting and secure the smooth and favorable operation of the internal combustion engine, and to simplify the structure and facilitate the production.

[0010]

The means of the present invention for solving the above technical problems is to supply a primary short-circuit current through an ignition circuit to a primary winding of an ignition coil in which an ignition plug is connected to a secondary winding, A non-contact ignition device for an internal combustion engine that abruptly interrupts this primary short-circuit current by an ignition circuit to induce a high voltage in the secondary winding of the ignition coil to generate a spark discharge in an ignition plug and perform an ignition operation. The first charging capacitor for charging the reverse voltage induced in the primary winding of the ignition coil, the diode, and the "continuation" of the vehicle clutch to turn on and disconnect. By having a first charging circuit connected in series with a clutch switch that is turned off by, it is possible to trigger by charging the first capacitor in the discharging circuit connected to the first capacitor of the first charging circuit. Condition And having a first switching element that disables the ignition circuit to perform an ignition operation by a trigger, and a second charging capacitor and a diode for charging a reverse voltage induced in the primary winding of the ignition coil. Having a second charging circuit connected in series, in the discharging circuit connected to the second capacitor of this second charging circuit,
The second switching element has a second switching element which is in a triggerable state when the second capacitor is charged to a predetermined value or more and which is turned off by the trigger.

A first switching element is connected in parallel with the primary winding of the ignition coil, or an ignition circuit is connected in parallel with the primary winding of the ignition coil for passing a primary short-circuit current. , A thyristor connected to the base of the transistor circuit to cut off the transistor circuit when turned on,
It is better to connect the switching element of No. 2 between the gate and cathode of the thyristor of the ignition circuit.

It is advisable to set the constant value of the reverse voltage charge value of the second capacitor, which enables the second switching element to be triggered, to a value corresponding to idling of the internal combustion engine.

When the first switching element is connected in parallel with the primary winding of the ignition coil, it is preferable to use a thyristor, and when it is connected between the gate and cathode of the thyristor of the ignition circuit, a transistor is used. Good to do.

[0014]

When the clutch of the vehicle is in the "disengaged" state, the clutch switch is in the off state, so that the first charging circuit is in the "open" state. The reverse voltage induced in the primary winding is not charged and the first switching element is not triggered.

In the state where the first switching element is not triggered, the ignition circuit maintains the ignition operable state, so that in this state the start of the internal combustion engine is achieved without any trouble and the primary winding of the ignition coil is induced. A part of the reverse voltage thus generated flows through the second charging circuit and charges the second capacitor.

When the charging voltage of the reverse voltage of the second capacitor becomes equal to or higher than a predetermined value that corresponds to the speed of the internal combustion engine, the second switching element becomes the trigger state, which is the second state. It is held as long as the charging voltage of the capacitor is equal to or higher than the set constant value.

When the clutch is switched to the "continuous" state when the speed of the internal combustion engine is equal to or higher than a preset constant value, that is, the charging voltage of the second capacitor is equal to or higher than the preset constant value, the clutch switch operates. When turned on, the first charging circuit is closed, and the first capacitor is charged with a part of the reverse voltage induced in the primary winding of the ignition coil, but the second switching element is in the trigger state. So
The triggering of the first switching element by the charging voltage of the first capacitor is not achieved, and the ignition circuit continues the ignition operation without trouble.

On the other hand, when the internal combustion engine is started with the clutch "on", the clutch switch is on, so the first charging circuit is "closed". Therefore, the first capacitor is charged with a part of the reverse voltage induced in the primary winding of the ignition coil,
The switching element of becomes a trigger state.

When the first switching element is triggered, the ignition circuit is in the ignition disabled state and the internal combustion engine does not operate. Therefore, it is not possible to start the internal combustion engine with the clutch in the "continuous" state. It will be possible.

At the time of starting the internal combustion engine, the speed of the internal combustion engine is, of course, low and a part of the reverse voltage induced in the primary winding of the ignition coil charged in the second capacitor. The value of the charging voltage of does not reach the set constant value, so that the second switching element cannot trigger and the triggering state of the first switching element is maintained.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. 1 shows the basic configuration of the present invention and the circuit configuration of an ignition circuit TC most suitable for implementing the present invention, which is shown in FIG. 1 prior to the description of the embodiment of the present invention. The ignition circuit TC will be briefly described.

The ignition circuit TC is of the induction discharge type, and a transistor circuit 23 (in the case of the illustrated embodiment) is provided between both terminals of a primary winding T1 of an ignition coil T in which an ignition plug P is connected to a secondary winding T2. , A Darlington circuit is used, but in some cases, one power transistor may be connected) with a collector and an emitter. In parallel with this transistor circuit 23, a resistor 25 and an anode are connected to the base of the transistor circuit 23. A series circuit with the thyristor 24 is connected, and the collector of the transistor circuit 23 and the thyristor 24 are connected.
A series circuit of the variable resistance 26 and the resistance 27 is connected between the gate of the thyristor 24 and the gate of the thyristor 24.
It is configured by connecting a series circuit of a resistor 28 and a diode 30 for temperature compensation of the gate voltage of the thyristor 24.

The emitter of the transistor circuit 23
Reversed diode 31 and resistor 2 connected between bases
A series circuit with 9 is an premature ignition prevention circuit in the ignition circuit TC. When this premature ignition prevention circuit is provided, the transistor circuit 23 needs to be a Darlington circuit, and both of the circuits that form this Darlington circuit. It is good to connect a resistor between the base and emitter of the transistor.

In this ignition circuit TC, when the forward voltage starts to rise in the primary winding T1, the resistance 2 is applied in accordance with this voltage.
A current flows into the base of the transistor circuit 23 through 5 to make the transistor circuit 23 conductive, and a primary short-circuit current flows through the primary winding T1 through the transistor circuit 23.

When the induced voltage in the primary winding T1 rises and the primary short-circuit current increases to a value set by the resistors 26 and 27, the thyristor 2 passes through the resistors 26 and 27.
The gate potential of the thyristor 24 reaches the trigger gate potential by the component current flowing through the resistor 28 and the diode 30, which is the gate circuit of No. 4, and triggers the thyristor 24.

When the thyristor 24 triggers, the potential of the base of the transistor circuit 23 decreases to the potential of the emitter to a value at which the conductive state of the transistor circuit 23 cannot be maintained, so that the transistor circuit 23 and the transistor circuit 23 are cut off. The primary short-circuit current that has been flowing through the secondary winding T1 is suddenly interrupted, and by the interruption of this primary short-circuit current,
A high voltage is induced in the secondary winding T2, a spark discharge is generated in the spark plug P, and an ignition operation is performed.

The control circuit 1 according to the present invention is connected to the ignition circuit TC, and has a structure in which the ignition operation of the ignition circuit TC is disabled by short-circuiting both terminals of the primary winding T1. There is a configuration in which the ignition operation of the ignition circuit TC is disabled by disabling the trigger of the thyristor 24 of the ignition circuit TC.

FIG. 2 shows an embodiment configured to disable the ignition operation of the ignition circuit TC by short-circuiting both terminals of the primary winding T1. The plus side terminal of the primary winding T1 is shown in FIG. And a terminal D connected to the terminal A of the ignition circuit TC,
The primary winding T1 is connected between the negative terminal of the primary winding T1 and the terminal E connected to the terminal B of the ignition circuit TC.

The first charging circuit 2 is a clutch switch KS which is turned on by "continuation" of the vehicle clutch and turned off by "disconnection", a diode 7b in an opposite posture, and a resistor 10.
, A first charging capacitor 6 and a diode 7a having an opposite posture are connected in series between terminal D and E, and the first switching element 3 is a thyristor between terminal D and E. The second charging circuit 4 connected to the second charging circuit 4 is a series circuit including a diode 9b having an opposite posture, a resistor 11, a second charging capacitor 8 and a diode 9a having an opposite posture. The second switching element 5 is a transistor, and is connected between the collector and the emitter of the thyristor, which is the first switching element, between the gate and the cathode of the thyristor.

The thyristor, which is the first switching element 3, has its gate connected to the positive electrode of the first charging capacitor 6 via the resistors 12 and 13,
Triggering is possible by the charging voltage of the first charging capacitor 6, and the transistor, which is the second switching element 5, has its base connected to the second charging capacitor 8 via the resistors 16 and 15 and the diode 19. By connecting to the positive side electrode, it can be turned on by the charging voltage of the second charging capacitor 8.

A resistor 14 forming a discharging circuit of the first charging capacitor 6 is connected between the negative side electrode of the first charging capacitor 6 and the terminal E, and similarly the second switching circuit is connected. Base of transistor, which is element 5
The adjusting resistor 17 connected between the emitters and the resistor 18 connected between the negative side electrode of the second charging capacitor 8 and the terminal E form a discharging circuit of the second charging capacitor 8. ing.

The capacitor 21 connected between the anode and cathode of the thyristor which is the first switching element 3 and the capacitor 22 connected between the gate and cathode are for protecting the thyristor from surge voltage. Yes, the capacitor 2 connected between the base and emitter of the transistor that is the second switching element 5.
0 is for establishing turn-on of the transistor.

FIG. 3 shows an embodiment in which the ignition operation of the ignition circuit TC is disabled by disabling the thyristor 24 of the ignition circuit TC.
Of the thyristor 24, the terminal D connected to the terminal A of the ignition circuit TC which is the positive side terminal of 1, the terminal E connected to the terminal B of the ignition circuit TC which is the negative side terminal of the primary winding T1. A terminal connected to the terminal C of the ignition circuit TC which is a gate.

In the case of the embodiment shown in FIG. 3, except that the first switching element 3 is composed of a transistor, and the collector of this transistor is connected to the terminal connected to the terminal C, other The circuit configuration of is the same as that of the embodiment of FIG.

When the internal combustion engine is started with the clutch of the vehicle in the "disengaged" state, the first charging circuit 2 is in the open circuit state because the clutch switch KS is off, so that the first charging is performed. Since the reverse voltage generated in the primary winding T1 is not charged in the capacitor 6 for use and the first switching element 3 is not triggered, the ignition circuit TC performs the ignition operation without any trouble.

At the time of starting the internal combustion engine, since the second charging circuit 4 is closed, the second charging capacitor 8 is charged with the reverse voltage of the primary winding T1. Since the speed is low, the charging voltage is small, and the diode 19 whose discharge time constant is adjusted and set in advance by the resistor 17 is used.
Through the discharge circuit composed of the resistors 15, 16, 17, and 18, the primary winding T1 is discharged before the forward voltage rises.

When the rotation speed of the internal combustion engine rises and enters the idling state, the charging voltage of the reverse voltage of the second charging capacitor 8 becomes sufficient, and the second switching element 5 is always in the trigger state.

Therefore, after the internal combustion engine is in the idling state, the clutch switch KS is turned "on" by operating the clutch to bring the vehicle into operation to put it in the "continuous" state, and the first charging circuit is activated. Even when 2 is closed and the reverse voltage is charged in the first charging capacitor 6, the reverse voltage charged in the first charging capacitor 6 is bypassed by the second switching element 5 in the trigger state. Since the first switching element 3 cannot be triggered by this, the ignition circuit TC continues its operation.

When the internal combustion engine is started with the clutch of the vehicle in the "continuous" state, the clutch switch KS is in the "on" state, so that the first charging circuit 2 is closed and the first charging circuit 2 is closed.
The charging capacitor 6 is charged with the reverse voltage generated in the primary winding T1, and the first switching element 3 is triggered.

Since the ignition circuit TC cannot perform the ignition operation due to the trigger of the first switching element 3, the internal combustion engine cannot be driven.

At this time, since the second charging circuit 4 is always closed, the second winding capacitor 8 also has the primary winding T.
The reverse voltage of 1 is charged, but as described above,
Since the reverse voltage of the primary winding T1 until the idling time including the start of the internal combustion engine is insufficient to trigger the second switching element 5, the first switching element 3
Does not disable the triggering by the second switching element 5, but reliably triggers and holds the ignition circuit TC reliably in an inoperable state.

When the first switching element 3 is directly connected in parallel with the primary winding T1, the control circuit 1 has only two terminals, terminals D and E, so that the structure thereof is simplified. While the connection work for the ignition circuit TC is facilitated, the induced voltage of the primary winding T1 directly acts, so it is necessary to use a thyristor having a high withstand voltage. When an inexpensive transistor is used as the first switching element 3, since the withstand voltage capability of the transistor is low, the direct primary winding T1
Since it cannot be connected in parallel with the control circuit 1 and it is necessary to provide the control circuit 1 with a dedicated terminal, the structure of the control circuit 1 becomes complicated and the work of connecting and mounting the ignition circuit TC becomes troublesome.

[0043]

Since the present invention has the above-mentioned structure, it has the following effects. Except for the clutch switch that is controlled by the clutch of the vehicle, the structure is such that it is connected only to the ignition circuit of the internal combustion engine, and it is a combination structure of a charging circuit for the reverse voltage of the ignition coil and its discharging circuit. Is extremely simple and easy to handle.

Since the operation adjustment only needs to adjust the resistance value for setting the discharge time constant of the second charging circuit, the adjustment after mounting on the internal combustion engine can be made extremely simple and accurate, Therefore, reliable and stable operation can be easily obtained.

Since the components other than the clutch switch are made up of pure electronic components, the entire device can be manufactured in an extremely small size, so that it is easy to install the device adjacent to the ignition circuit or integrally with the ignition circuit. Therefore, the mounting space is not limited, and the mounting can be easily performed at a desired position.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing a basic configuration of the present invention and a configuration example of an ignition circuit suitable for connecting the circuit of the present invention.

FIG. 2 is an electric circuit diagram showing an embodiment of the present invention.

FIG. 3 is an electric circuit diagram showing another embodiment of the present invention.

[Explanation of symbols]

1; control circuit 2; first charging circuit 3; first switching element 4; second charging circuit 5; second switching element 6; first charging capacitors 7, 7a, 7b; diode 8; 2 charging capacitors 9, 9a, 9b; diodes 10, 11, 12, 13, 14, 15, 16, 17, 1
8, 25, 26, 27, 28, 29; resistors 19, 30, 31; diodes 20, 21, 22; capacitor 23; transistor circuit 24; thyristor KS; clutch switch TC; ignition circuit T; ignition coil T1; primary coil Winding T2; Secondary winding P; Plug

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yu Mochizuki 1-5-14 Shimo-Meguro, Meguro-ku, Tokyo Iida Denki Kogyo Co., Ltd. (56) Reference JP-A-53-70227 (JP, A) Kai 54-103927 (JP, A) Actual Kaihei 5-58876 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02P 11/04 F02P 3/04

Claims (6)

(57) [Claims] 1. A primary short-circuit current is passed through an ignition circuit (TC) to a primary winding (T1) of an ignition coil (T) in which an ignition plug (P) is connected to a secondary winding (T2), By rapidly shutting off the short circuit current in the ignition circuit (TC), the secondary winding (T2)
In a non-contact ignition device for an internal combustion engine, which induces a high voltage to the spark plug (P) to generate a spark discharge and performs an ignition operation, the reverse voltage induced in the primary winding (T1) is charged. The first charging capacitor (6), the diode (7),
A first charging circuit (2) is connected in series with a clutch switch (KS) that is turned on when the vehicle clutch is "continued" and turned off when it is "disengaged", and is connected to the first capacitor (6). In the discharge circuit, a first switching element (3) is provided, which becomes a triggerable state by charging the first capacitor (6) and disables the ignition operation of the ignition circuit (TC) by the trigger, A second charging capacitor (8) and a diode for charging the reverse voltage induced in the primary winding (T1)
A second charging circuit (4) in which (9) and (9) are connected in series is formed, and a predetermined constant of the second capacitor (8) is set in the discharging circuit connected to the second capacitor (8). A second state in which the first switching element (3) is disabled from being turned on by the trigger when the charging is performed at a value or more
A starting control circuit in a non-contact ignition device for an internal combustion engine, which is provided with the switching element (5). 2. A starting control circuit for a non-contact ignition device for an internal combustion engine according to claim 1, wherein the first switching element (3) is connected in parallel with the primary winding (T1) of the ignition coil (T). . 3. A transistor circuit (23) in which an ignition circuit (TC) is connected in parallel with a primary winding (T1) of an ignition coil (T) so as to flow a primary short-circuit current, and the transistor circuit (23). To turn off the transistor circuit (23)
A thyristor (24) connected to the base of the thyristor (2).
The start control circuit in the non-contact ignition device for an internal combustion engine according to claim 1, which is connected between the gate and the cathode of 4). 4. The constant value of the reverse voltage charge value of the second capacitor (8) which enables the second switching element (5) to be triggered is set to a value corresponding to the idling of the internal combustion engine. The starting control circuit in the non-contact ignition device for an internal combustion engine according to 2 or 3. 5. The start control circuit for a non-contact ignition device for an internal combustion engine according to claim 1, 2 or 4, wherein the first switching element (3) is a thyristor. 6. The start control circuit for a non-contact ignition device for an internal combustion engine according to claim 1, 3 or 4, wherein the first switching element (3) is a transistor.