JPS5934867B2 - Ignition method and device that does not require a distribution board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for periodic ignition, in particular for igniting an internal combustion engine without the need for a distributor.

"Switchboard-free ignition" means that the voltage impulse generated, for example for igniting a spark plug, can be transferred to individual ignition points, e.g. without the aid of an ignition switchboard located in the transmission path of the impulse. This is a method of igniting by sequentially distributing it to the spark plugs.

In other words, this type of ignition switchboard is extremely sensitive to moisture, dirt, etc., and has the disadvantages that the contacts on the switchboard wear out due to wear, and the longer it is used, the more inaccurate it becomes and the reliability decreases. This prohibits its use due to the fact that it is

There are also ignition systems in which the voltage or current forming the high-voltage impulse is distributed by means of a number of interrupters on the primary side of the ignition coil, for up to two spark plugs to be ignited at the same time. A separate ignition coil is required for each.

That is, two ignition coils are required for a four-cylinder engine, which results in a relatively high cost and a considerable space requirement for the ignition system.

The purpose of the present invention is to be relatively inexpensive compared to conventional igniters;
Another object of the present invention is to provide an ignition device that requires little space for the ignition device and does not require a switchboard.

This object is achieved according to the invention as follows.

That is, the ignition transformer 2, 25 has a low voltage primary winding 1.24°38 and a high voltage primary winding 7.28, 49.
, 35, which is connected to the circuit of the primary winding and interrupts the current flowing through the primary winding between a period when the current flows in one direction and a period when the current flows in the other direction, thereby alternating polarity. The first switching means 4, 22 generates a voltage in the secondary winding.
．． 36, and a first spark discharge means 10°31. connected to the secondary winding.
52.59, first unidirectional conducting means 9, 29, 51, 58 which prevent current from flowing through the first spark discharge means only when the voltage in the secondary winding has one polarity; a second spark discharge means 12゜32.54, 57 connected to the secondary winding, preventing current from flowing through the second spark discharge means only when the voltage in the secondary winding has the other polarity; a second unidirectional conductive means 11, 30, 53, 56,
A current is caused to alternately flow through the spark discharge means of the spark discharge means 5, 2 connected to the primary winding circuit.
3.37, the current in the primary winding flowing in one direction through the first current path and in the opposite direction through the second current path is supplied from at least one DC power source Ul)+Un, ,
The current flowing through the primary winding in one direction is intermittently interrupted by a first opening/closing hand chain that is provided in the first current path and opens and closes in synchronization with the rotation of the internal combustion engine, and the current flowing through the primary winding in the other direction. is provided in the second current path and opens and closes complementary to the opening and closing operation of the first opening and closing means in synchronization with the rotation of the internal combustion engine.
The present invention provides an ignition device for an internal combustion engine that is intermittently shut off by an opening/closing means.

To this end, the present invention provides a device having the following features.

That is, one switching device is provided on the primary side of one high voltage transformer forming and/or charging at least one energy source, and the switching device is provided on the primary side of one high voltage transformer forming and/or charging at least one energy source. The energy source is controlled such that the current flows alternately in one direction and the opposite direction, and each current is interrupted while the direction of the current changes, and further has at least two spark gaps. in the discharge circuit at least one blocking or shorting device for blocking or short-circuiting the discharge current to the first spark gap during the discharge of the energy source in at least one direction; or both, so that only the second spark gap ignites, and at least during discharge by the energy source in the opposite direction, blocks the discharge current to the second spark gap; The device is characterized in that it comprises at least one blocking device and/or a shorting device in the discharge circuit such that a short circuit occurs in the second spark gap, so that only the first spark gap ignites.

The invention thus uses a unique device for forming the ignition impulse, in particular a unique ignition coil, and
Nevertheless, it is possible to have the advantages of an ignition system that does not require a switchboard, which eliminates the above-mentioned conventional disadvantages, especially of the ignition switchboard on the high voltage side.

Next, the features and effects of the present invention will be explained in detail with reference to the accompanying drawings.

First, the embodiment of FIG. 1 based on the principle of the present invention shown in FIG. 1 will be described.

Here, the primary coil 1 of the ignition transformer or ignition coil 2 is connected at one end 3 to the positive supply voltage terminal Up on the one hand and to the negative supply voltage terminal Up on the other hand through two switches 4, 5 connected in parallel. is connected to the power supply voltage terminal Un of
Further, the other end 6 is grounded.

The secondary coil 1 of said ignition transformer 2 is connected at one end 8 through a first diode 9 to the high voltage contact of a first spark gap 10 which is grounded and at the same time connected to said first diode 9. It is connected through a second diode 11 connected in antiparallel to the high-voltage contact of the second spark gap 12, which is grounded.

In that case, the other end 13 of the secondary coil 7 is also grounded to complete a secondary current circuit.

The device according to the invention is constructed as follows.

That is, the current flowing through the primary coil 1 of the ignition transformer 2 is intermittently interrupted and alternately flows in the opposite direction each time.

That is, at the first point in time, a current is passed through the primary coil 1 from the terminal 3 to the terminal 6, then this current is cut off at the second point in time, and at the third point in time, the current is caused to flow. The current is passed through the primary coil 1 in the opposite direction from terminal 6 to terminal 3, and the current is cut off at the fourth point in time.

At the fifth point in time, the current again flows from contact 3 to contact 6 in the same way as at the first point.

The induced current in the secondary coil 7 flows only in a predetermined direction toward one spark gap 10 when one switch is opened, and flows through the other spark gap 12 when the other switch is opened. Flows only in the opposite direction.

In this way, when the switch 4 is closed, the primary coil 1
The potential of the terminal 3 becomes a positive potential Up with respect to the ground, and as a result, a current flows from the terminal 3 to the terminal 6 through the primary coil 1.

When the switch 4 is opened, there is one negative high-voltage impulse at the terminal 8 which passes through the diode 11 but not through the diode 9, so that a spark discharge takes place only in the spark gap 12.

When the switch 5 is subsequently closed, the potential at the terminal 3 becomes a negative potential Un with respect to ground, so that the current in the primary coil 1 flows in the opposite direction from the terminal 6 to the terminal 3.

When switch 5 opens, a positive high voltage pulse is thereby applied from terminal 8 through diode 9 to spark gap 10 to create a spark discharge.

Due to the blocking effect of the diode 11, no spark discharge can occur in the spark gap 12.

It is clear here that in order to intermittently cut off the current in the primary coil 1 and allow it to flow alternately in one direction and in the opposite direction each time, separate positive and negative power supplies must be provided. is not necessarily necessary.

An example would be two bipolar changeover switches and a positive or negative voltage source, with one switch connected between one end of the primary coil and ground, and the other switch connected between the other end of the primary coil and ground. Alternatively, an alternating current may be caused to flow through the primary coil by connecting one voltage source to the primary coil and alternately opening and closing two switches.

FIGS. 2 and 3 are examples in which one DC power source is used in this manner.

In these embodiments, the primary coil of the ignition transformer is provided with one center tap (14 or 15) connected to the pole of the DC voltage source, e.g. It is connected to ground via the first and second changeover switches.

FIG. 2 shows a second embodiment of the invention.

In FIG. 2, a cam 17 installed on a rotating shaft 16 that rotates in synchronization with the rotation of the engine controls double-pole single-throw switches 18 and 19 that are arranged with a 180° offset.

The switch 18.19 connects the resistor 20.21 and the resistor 20.21 so that the transistor 22.23 is alternately conductive and both transistors are non-conductive during the switching of conduction from one transistor to the other. The transistors 22 and 23 are connected to each other.

The primary coil 24 of the ignition transformer 25 is formed by one push-pull coil, and the potential of its center tap 14 is set to the output potential UB of the DC power supply.

One transistor 22 connects one end 26 of the primary coil 24, and the other transistor 23 connects the other end 27 to ground when they are made conductive, so that when both transistors are made alternately conductive, current is alternately drawn. The current flows in the primary coil 24 in one direction and the other, and both transistors are non-conducting while the current changes direction.

As a result, a voltage impulse is formed in the secondary coil 28 when the primary current is switched off, since a magnetic field of a different direction is generated in the ignition transformer 25 according to the conduction of the transistor 22 or 23.

The polarity of this impulse depends on which transistor created the magnetic field.

Between the ground and each end of the secondary coil 28 of the ignition transformer 25, that is, between each end of the secondary coil 28 and the ground, high voltage diodes 29, 30 are provided in parallel with the spark gap 31, 32. and they are connected in such a way that only one of the spark caps 31, 32 can be ignited according to the direction of the current flowing through the secondary coil.

A diode 33.34 is connected between each end 26.27 of the primary coil and the corresponding transistor 22.23.

The polarity of these diodes is such that when the magnetic field in the ignition transformer 25 disappears due to transistors 22 or 23 becoming non-conducting, a large peak voltage is created in the primary coil 24, which causes the l. It is set to prevent conduction.

FIG. 3 shows another embodiment of the invention for a four-cylinder engine.

Similar to the embodiment shown in FIG.
A magnetic field is generated in one direction and the other direction through the secondary coil 38, but a more detailed explanation thereof will be omitted.

Diode 39.40 is diode 33 in FIG.
゜34, respectively.

However, the control of transistors 36 and 37 is different from FIG.

Transistors 36,37 are provided with a control voltage through control inputs 41-42.

Zener diode 43.4 located in parallel with the control input
By using 4, the resistance 45.4 is connected to the input 41°42.
switching transistor 36.6 connected via switching transistor 36.6;
The control voltage for 37 is kept constant.

The current flowing through the primary coil 38 of the ignition transformer 35 therefore has a value independent of the drive voltage, depending on the bias resistor 47.48 located in the emitter circuit of each transistor.

When the control voltage to the transistor is interrupted, a voltage impulse is formed in the secondary coil 49, the polarity of which depends on which of the transistors 36, 37 is turned on.

One end 50 of the secondary coil 49 of the ignition transformer 35 is connected to the first
is connected to a first spark gap 52 through a diode 51 , and to a second spark gap 54 through a second diode 53 connected antiparallel to the first diode 51 .

The other end 55 of the secondary coil 49 is connected to a third spark gap 57 through a third diode 56 arranged similarly to the first diode 51 and to a third spark gap 57 .
is connected to a fourth spark gap 59 through a fourth diode 58 arranged similarly.

The other end of the spark gap is grounded in conventional manner.

When a positive peak voltage appears at one end 50 of the secondary coil 49, a diode 53 and a diode 56 at the other end
is actuated thereby igniting the spark gap 54,57.

High-energy spark discharge can be generated even in the low engine speed range.

This is because the opening/closing speeds of the two switches are independent of the engine rotational speed, so the voltage generated by the ignition coil is independent of the engine rotational speed.

High-energy spark discharges can be generated even at high engine speeds.

This is because each of the two switches can close as soon as the other opens.

Therefore, since the connection of the primary winding is not interrupted for more than a certain period of time, the magnetic field of the ignition transformer can be sufficiently saturated even during high speed rotation.

In this way, the ignition transformer can be used efficiently.

Furthermore, when one switch opens, the other switch closes immediately, so the reversal of the magnetic field generated by opening one switch is maintained by closing the other switch, so the induced voltage in the secondary winding increases. Ru.

As described above, the ignition device of the present invention has a significant magnetic field.

A damping element 60 connected between terminals 61 and 62 of the primary coil 38 damps undesired oscillations.

Examples of damping elements are presented in figures 48-4f.

It is important to prevent such undesired oscillations, as such oscillations, i.e. changes in the direction of the current in the primary coil, can generate voltage changes in the secondary coil, which can ignite the spark gap. It is.

Braking element 60 shown in FIGS. 3 and 4a to 4f
would not be necessary if the switches 4, 5; 22, 23; 36, 37 were operated continuously, ie if one switch were opened immediately after the other one was closed.

In this case, 76, 77, 78 in Figure 5 and 65 in Figure 6.
．． Any possible oscillations shown at 66.67 are suppressed by the low internal resistance of the power supply, which is normally connected to the primary winding of the ignition transformer.

However, at low and medium speeds of the engine, the magnetic field of the ignition transformer quickly saturates, so it is not necessary to operate the two switches continuously, i.e., immediately after opening one switch, the other switch is activated. It is not necessary to close the magnetic field, and it is not preferable to do so because power will be supplied even when the magnetic field reaches a saturated state.

Therefore, one switch can be opened before the other switch is closed.

In this way, when the magnetic field reaches saturation, both switches are opened, resulting in a significant reduction in power consumption.

However, in this way the above-mentioned oscillations can occur while both switches are in the open state.

Therefore, a braking element is provided to suppress such oscillations in the middle and low speed range of the engine and prevent ignition errors.

That is, the above oscillation can be suppressed by connecting a braking element that can cause eddy current loss or a braking element that short-circuits the primary coil to the primary winding of the ignition transformer.

All braking elements shown in FIGS. 4a to 4f are connected in parallel to the primary coil 1, 24 or 38 or to a portion thereof.

It is also possible to install a separate braking coil on the ignition transformer, which cooperates with the braking element 60.

FIG. 4a shows an ohmic resistor, which can also be formed by a damping or energy-consuming phase included in the core of the ignition transformer.

Also, an ignition transformer having a core consisting of a single transformer plate or a plurality of transformer plates having a relatively high eddy current product may be used instead of FIG. 4a.

FIG. 4b shows the voltage dependent resistance (VDR), FIG. 4c shows the capacitor, and FIG. 4d shows the control electrode 63 at the leading edge of the second current half-wave after the extinction of the magnetic field in the ignition transformer. The triac is shown energized by an auxiliary pulse at .

When a triac conducts, it short-circuits subsequent vibration waves.

This will be explained later in connection with FIG.

In FIG. 6, the control current of transistor 36 is I36
On the other hand, the control current of the transistor 37 is expressed as ■3
It is □.

U3O is an oscillating voltage induced in the secondary coil 49 when the braking element 60 in FIG. 3 is not provided.

(2) J63 is a control voltage to the triac shown in FIG. 4d, which is provided as the braking element 60 in FIG.

U49 is the induced voltage to the secondary coil 49 when a triac as a braking element is present.

Finally, U54 57 is the voltage at the spark gap 54,57 and U345□ is the voltage at the spark gap 52,59.

The transistor 36 is made conductive by the control current 36 at time 11 and cut off at time t2.

When the transistor 36 is switched off, several peak voltages 64 to 67 of different peak values and polarities appear in the secondary coil 49, starting with a positive peak voltage in the absence of a damping element.

When a braking voltage U63 is applied to the control electrode 63 of the triac at time t3 when the first peak voltage 64 disappears, the triac becomes conductive, so that only one positive peak voltage 64 appears in the secondary coil 49.

The duration of the control voltage pulse 93 is set so that all unnecessary peak voltages 65, 66, and 67 are suppressed.

In this way, one positive ignition voltage pulse 68 is obtained at the spark gap 54.degree. 57.

Similarly, a negative ignition voltage pulse 69 is formed in the spark gap 52,59, which will not be described in detail.

In this way, the braking element 60 shown in FIG. d imme
r) The triac in the circuit is ignited after a predetermined time determined by resistor 71, capacitor 72 and guiac 73 and short-circuits the resonant voltage from this point on.

Figure 4f shows a circuit that shorts out the resonance when the voltage of the main ignition impulse 74 decays to a small voltage value.

This is accomplished through a bridge circuit 75 that rectifies the alternating pulsed voltages 74, 76° γ7, 78, etc.

These rectified pulses 79°80.81.82 etc. (5th
U3384) in the figure is composed of a resistor 85 and a capacitor 86 connected in series with it, and is integrated in the capacitor 86 of the CR circuit located in parallel with the output point 83.84, indicating one integrated voltage U1 (5) 86 in the voltage waveform use).

When the output voltage uaa 84 of the bridge rectifier drops to approximately the above integrated voltage value (at time t4 in Fig. 5),
A unijunction transistor connected in series with the resistor 89.90 and in parallel with the output point 83.84 of the bridge circuit 15, like the cyrisk 87, and whose control electrode 91 is connected between the capacitor 86 and the resistor 85. 8
8 ignites.

The UJT 88 is further connected to the thyristor 87 so as to ignite the thyristor 87 upon its ignition, thereby generating a resonant pulse 76°7 following the main impulse 74.
7.78 mag will be suppressed.

The ignition of the Cylisk 87 is caused by the voltage U9o generated across the resistor 90.
This is done by a voltage pulse 92 of .

The pulse width of this voltage pulse 92 is set to be long enough (up to t in FIG. 5) to suppress all resonant waves by means of a properly sized resistor 85 and capacitor 86.

[Brief explanation of the drawing]

FIG. 1 is a principle circuit diagram showing a first embodiment of the present invention and for explaining the basic principle of the present invention, FIG. 2 is a circuit diagram showing a second embodiment of the present invention, and FIG. The figure shows the third aspect of the present invention.
The circuit diagrams, FIGS. 4a to 4f, showing the second embodiment are as follows:
FIG. 3 shows a modification of the braking element located in parallel on the primary side of the ignition coil or ignition transformer, and FIG.
A voltage waveform diagram for explaining the action of the braking element shown in the figure,
FIG. 6 shows a current and voltage waveform diagram for explaining the operation of the circuit shown in FIG. 3 when the braking elements shown in FIGS. 4a to 4f are connected. Explanation of symbols, 1...Primary coil, 2...
・Ignition coil, 7...Secondary coil, 9, 11・
...Diode, 14,15...Center tap, 18,19...Double-pole single-throw switch, 20
, 21...Resistor, 22゜23...Transistor, 25...Ignition transformer, 29, 30
...High voltage diode, 38...Push-pull primary coil, 43,44...Zener diode, 45,46...Series resistance, 60...
... Working element, 72 ... Capacitor, 13
...Diac, 75...Bridge circuit, 87...Sirisk.

Claims (1)

[Claims] 1. Ignition transformer 2° 25.35 having a low voltage primary winding 1, 24.38 and a high voltage primary winding 7, 28.49
and, connected to the circuit of the secondary winding, interrupting the current flowing through the secondary winding between a period in which the current flows in one direction and a period in which the current flows in the other direction, thereby first switching means 4,22.36 for generating voltages with alternating polarities in said secondary winding; and first spark discharge means 10.3 connected to said secondary winding.
1, 52, 59, and first unidirectional conductive means 9, 29, 51 which prevent current from flowing through said first spark discharge means only when the voltage in said secondary winding has one polarity. 58, and second spark discharge means 12.3 connected to said secondary winding.
2,54.57, and second unidirectional conductive means 11,30°53 for preventing current from flowing through said second spark discharge means only when the voltage in said secondary winding has the other polarity. .56, the ignition device for an internal combustion engine is configured to alternately flow current through the first and second spark discharge means, further comprising: a second opening/closing means 5 connected to the secondary winding circuit;
, 23.37, through the first current path in one direction,
The current flowing through the secondary winding in the opposite direction through the second current path is supplied from at least one DC power supply Up, Un, and the current flowing in the secondary winding in one direction is supplied from the first The current path is intermittently cut off by the first opening/closing means, which is provided in the current path of the internal combustion engine and opens and closes in synchronization with the rotation of the internal combustion engine.
The current flowing in the other direction through the next winding is intermittently interrupted by the second opening/closing means, which is provided in the second current path and opens and closes in synchronization with the rotation of the internal combustion engine in a complementary manner to the first opening/closing operation. The ignition device for an internal combustion engine as described above. 2. The ignition device for an internal combustion engine according to claim 1, characterized in that braking means 60, 70 to 90 are connected to both ends of the secondary winding.