DE2339784A1 - PROCEDURE AND ARRANGEMENT FOR DISTRIBUTORLESS DISTRIBUTION - Google Patents

Description

PATENT ADVOCATE DIPL.-PHYS. JOHN SPIES

8 MUNICH 22 WIDENMAYERSTRASSE 48 TELEPHONE: (0811) 2269 17 TELEGRAM SHORT ADDRESS: PATOMIC MUNICH

Dr. Gunter Hartig, Karlsruhe '

Method and arrangement for distributorless ignition

The invention relates to a method and an arrangement for the distributorless ignition of devices to be ignited cyclically, in particular of internal combustion engines.

"Distributorless ignition" is to be understood as such an ignition in which the high-voltage pulses generated for ignition, for example spark plugs, do not have a Distributor located in their transmission path to the individual ignition points, such as spark plugs, distributed will. Because such ignition distributors are extremely sensitive to moisture, dirt and the like., They are subject to wear and tear due to the burning of the distributor contacts and become more and more imprecise with increasing service life and less reliable.

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There are already "distributorless" ignition systems in the sense of the above definition, in which the distribution of the voltages or currents generating the high-voltage pulses on the primary side of the ignition coil by means of several breakers is carried out, but in each case for a maximum of two - namely to be ignited at the same time - spark plugs requires a separate ignition coil; so for a 4-cylinder engine two ignition coils are required, which is relative is expensive and has a relatively large space requirement for the ignition system.

The object of the invention is to provide a method and an arrangement for ignition without distribution is less expensive and in particular leads to a smaller space requirement for the ignition system.

in

This object is achieved / a method that is inventively characterized by the fact that on the primary side of a high-voltage transformer (ignition or charging transformer) which is the energy source and / or charges), alternating a current in one and a current in the can flow in the opposite direction, with the respective current flow between two periods of current flow interrupts and the energy source alternately in one and after the subsequent interruption of the current flow in the opposite direction at least partially discharged, and that one of at least two in the discharge circuit of the energy source lying spark gaps when discharging the energy source in one direction one of the two spark gaps for which blocks and / or short-circuits one direction of current, on the other hand when discharging the current source in the opposite direction

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the other of the two spark gaps for the opposite one Current direction blocks and / or short-circuits.

In order to carry out this method, the invention proposes an arrangement which is characterized thereby is that a switch arrangement on the primary of a at least one energy source forming and / or charging high-voltage transformer is provided and controllable in this way is that on the primary side a current flows alternately in one direction and a current in the opposite direction and that between two successive periods of current flow the respective current is interrupted; and that further in the discharge circuit having at least two spark gaps the energy source at least one blocking device and / or a short-circuit device is provided that the Discharge current at least during the discharge of the energy source in one direction for the first spark gap blocks or short-circuits at the first spark gap, so that then only the second spark gap ignites, and that continues at least one blocking device and / or a short-circuit device is provided in the discharge circuit, which controls the discharge current at least during the discharge of the energy source in the opposite direction for the second spark gap blocks or short-circuits at the second spark gap, so that then only the first spark gap ignites.

In this way, the invention makes it possible to use a single system for generating ignition pulses, in particular one get by with a single ignition coil, and still get the advantage of a "distributorless" ignition system, above all lies in the elimination of the disadvantages of high-voltage-side ignition distributors mentioned at the beginning.

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The above and other advantages and features of the invention, which are further detailed in the subclaims are disclosed below with reference to some, shown in principle in Figs. 1-6 of the drawing or explained embodiments described in more detail; show it:

Fig. 1 is a schematic diagram to explain the basic principle of the invention, the simultaneously represents a first embodiment of the invention;

Fig. 2 shows a second embodiment of the invention; 3 shows a third embodiment of the invention;

FIG. K shows several possible designs of the damping element lying parallel to the primary side of the ignition coil or the ignition transformer in FIG. 3; FIG.

5 shows a representation of voltage profiles over time to explain the mode of operation of the damping element according to FIG. 4f; and

6 shows a representation of current and voltage curves over time to explain the circuit arrangement according to FIG. 3 in connection with a damping element according to FIG. 4d. '·

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First, FIG. 1 will be discussed in more detail, from which the principle of the invention on the basis of a first, more schematic, Exemplary embodiment can be seen:

Here, the primary winding 1 of an ignition transformer or an ignition coil 2 is connected at one end 3 via two parallel switches k and 5 to a positive and a negative voltage U and U, respectively, while the other end 6 of the primary winding 1 is grounded is. The secondary winding 7 of the ignition transformer is connected at one end 8 via a first diode to the high-voltage connection of a first spark gap 10 which is connected to ground; In addition, the end 8 is simultaneously connected to the high-voltage connection of a second spark gap 12, which goes to ground, via a second diode 11, which is connected in the reverse direction in relation to the first diode ; the other end 13 of the secondary winding 7 is also connected ^to ground and the secondary circuit is thus closed.

The inventive method consists in that in the Primary winding 1 of the ignition transformer 2 a current flow alternately in one and the other - opposite direction, interrupted in each case by disconnections of the current flow in the primary winding 1, is caused. That means that at a first time in the primary coil 1 a Current from connection 3 to connection 6 is caused that this current is then switched off at a second time and at a third time allows a current to flow in the opposite direction across the primary coil 1, from terminal 6 to the Terminal 3, whereupon this current decreases at a fourth time.

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is switched. At a fifth time, the current is switched on again in the same direction as at the first time, etc. At the same time, the current in the secondary circuit - at least during the time in which the primary winding 1 is switched off is - to the one spark gap 10 only allowed through in a predetermined direction, while it is to the other Spark gap 12 is only allowed to pass in the opposite direction.

In this way, when the switch k is closed, the voltage U, which is positive to ground, is applied to the terminal 3 of the primary winding 1, so that a current flows from the terminal 3 to the terminal 6 via the latter. If the switch 4 is now opened, a negative high-voltage pulse arises at the terminal 8, which is allowed to pass by the diode 11, but is not allowed to pass by the diode 9, so that a spark discharge only occurs in the spark gap 12. If the switch 5 is then opened, the negative voltage U to ground is applied to the terminal 3, so that the current flow in the primary winding 1 takes place in the opposite direction from the terminal 6 to the terminal 3. When the switch 5 is opened, a positive high-voltage pulse is generated at the terminal 8, which is allowed through by the diode 9 and leads to a spark discharge in the spark gap 10, while no spark discharge can now occur in the spark gap 12 due to the blocking effect of the diode 11 .

Of course, it is not absolutely necessary at the same time provide a positive and a negative voltage source in order to interrupt the current in the primary winding

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Wells from their disconnection to flow alternately in one and in the opposite direction, but it can be provided, for example, two double-pole changeover switches in connection with only one voltage source, with which the one - not connected to ground - pole alternately to the one connection and the other terminal of the primary coil of the ignition transformer is placed, at the same time the other - preferably connected to ground - pole is connected to the open terminal of the primary coil. A particularly simple possibility, which is used in FIGS. 2 and 3, is to provide the primary coil of the ignition transformer with a center tap Ik or 15 and to connect it firmly to one pole, for example the positive pole, of the voltage source while the two ends of the primary winding are alternately connected to the other - preferably grounded - pole of the voltage source.

Fig. 2 shows the basic embodiment of an ignition system for a two-disc rotary piston engine. A cam 17 mounted on the eccentric shaft 16 controls the relocated switches 18 and 19 Transistor on the other both transistors are blocked for a certain time. The primary winding 2k of the ignition transformer 25 is formed by a push-pull winding, the center point Ik of which lies on the supply voltage U_. Since one transistor 22 has one end 26 and the other transistor 23 the other end 27 of the primary winding 2k each

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switched state with the other pole - connected to ground - which connects the voltage source delivering the supply voltage U_, it occurs, interrupted by periods, in which both transistors are blocked, alternately to a flow of current in one and in the other direction in the Primary winding 24. As a result, the magnetic field in the ignition transformer 25, depending on whether the transistor 22 or the Transistor 23 conducts, has different directions, when the primary current is switched off, a voltage pulse is generated in the Secondary winding 28 is generated, the polarity of which depends on which transistor has built up the magnetic field. The high voltage diodes 29 and 30, which are between mass and one each The end of the secondary winding 28 of the ignition transformer lie, that is, parallel to one between each end of the secondary winding 28 and ground provided spark gap 32 are switched in their forward direction so that according to the Magnetic field build-up or reduction can only ignite one of the two spark gaps 31 or 32.

A diode 33 or 34 is connected between each end 26 or 27 and the associated transistor 22 or 23. These diodes are polarized so that they operate the transistors 22 or 23 with reverse polarity prevent when the collapse of the magnetic field in the ignition transformer as a result of the respective transistor 22 being switched off or on the respective other part of the primary winding 24 a high negative Voltage peak arises.

Fig. 3 shows an embodiment of the invention for a four-cylinder engine. As in the exemplary embodiment 2 is here in the ignition transformer 35 on the Transistors 36 and 37 and push-pull primary winding 38

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Magnetic field generated in one and the other direction, so that a more detailed explanation is superfluous in this regard. The diodes 39 and 40 also correspond to the diodes 33 and 34 in Fig. 2.

In contrast to FIG. 2, however, the control of the transistors 36 and 37 is implemented. These get theirs Control voltage via control connections 4l or 42. By means of the Zener diodes 43, 44 in. parallel to the control voltage Connection to the intermediate series resistors 45, 46 is the control voltage for the switching transistors 36, kept constant, whereby the charging current in the primary winding 38 of the ignition transformer 35 due to the in the emitter circuit lying negative feedback resistors 47, 48 an operating voltage-independent End value owns. After switching off the control voltage, a voltage pulse is generated in the secondary winding 49, the polarity of which depends on which of the Transistors 36 or 37 was turned on.

One end 50 of the secondary winding 49 of the ignition transformer 35 is connected to a first spark gap 52 via a first diode 51 and to a second spark gap 54 via a second diode 53 with reverse polarity compared to the first diode 51. The other end 55 of the secondary winding 49 is connected via a third diode 56 with a third spark gap ^ 7, polarized in the same way as the first diode 51, and via a fourth diode 58 with a fourth polarized in the same way as the second diode 53 Spark gap 59 connected. The other ends of the spark gaps are connected to ground in the usual way.

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In the event of a positive voltage spike at point 50 of the Secondary winding 49 conduct the diodes 53 and 56, whereby the Spark gaps 54 and 57 are ignited. In the case of a negative Pulse spike at 50 conducts diodes 51 and 58, causing Spark gaps 52 and 59 are ignited.

The attenuator 60 according to FIG. 3 which lies with its connections 6l or 62 between the ends of the primary winding 38, dampens unwanted resonance vibrations. Embodiments of attenuators are shown in Fig. 4a to 4f. The reduction or suppression of resonance-related The ringing of the voltage is important because otherwise the polarity change associated with the ringing is important the complementary spark gap could ignite at an undesired time.

All of the damping elements according to FIGS. 4a to 4f described below are parallel to the primary winding 1, 24 or 38 or part of it. Of course, a separate damping winding can be provided on the ignition transformer that cooperates with the attenuator. Fig. 4a shows an ohmic resistance, this resistance can also be formed by damping or lossy material of the core of the ignition transformer.

Fig. 4b shows a voltage-dependent resistor (VDR), Fig. 4c shows a capacitor and Fig. 4d shows a triac whose control electrode 63 is triggered with an auxiliary pulse at the beginning of the second half-cycle after the collapse of the magnetic field in the ignition transformer, whereby the triac ignites and short-circuits the following resonance oscillations,

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■ which is explained in more detail below in connection with FIG. 6 will:

In detail, I_g here means the control current of the transistor 36, while I__ is the control current of the transistor 37. 0 '... Is the voltage occurring across the secondary winding 49 on the assumption that no attenuator 60 is provided in FIG. 3. U, - is the control voltage of a triac according to FIG. 4d, which is arranged as a damping element 60 in FIG. U. is the voltage across the secondary winding 49 in the presence of the above triac as an attenuator. Finally, U _., __ is the voltage across spark gaps 54 and 57 and U_ _O , _ _{Q is} the voltage across spark gaps 52 and

The transistor 36 is by a control current Ig at the time t. switched through and switched off _{at time t o.} As a result of the switch-off, several voltage peaks 64-67 successive in alternating polarity and decreasing in height, beginning with a positive voltage peak across the secondary winding 49, would occur without an attenuator. Now gives the damping triac at the control electrode 63 a control voltage U / -_, which - for example via a time and / or zero crossing detector - is controlled so that it ignites the triac at time t_, when the first voltage peak 64 ends, then only one positive voltage spike 64 is obtained across the secondary winding 49. The duration of the control voltage pulse 65 is chosen so that any disturbing voltage spikes 65, 66, 67 are suppressed. In this way, a clean positive ignition voltage pulse 68 is obtained at the spark gaps 54 and 57. The same applies to the generation of a clean negative ignition voltage impulse.

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pulses 69 at the spark gaps 52 and 59, so that there is no need for a more detailed explanation in this regard.

In Fig. 4e, a damping member 60 is shown in which a triac in a known dimmer circuit after a voi— certain time taken by the resistor 71 »the capacitor 72 and the diac 73 depends, ignites and from this point on short-circuits the resonance voltage.

4f shows a circuit which short-circuits the resonance oscillations when the voltage of the main ignition pulse lh. has decayed to a low voltage value again. This is achieved by a bridge circuit 75 »which rectifies the pulse voltages 7 ^, 76, 77, 78 etc. of different polarity. These rectified pulses 79, 80, 81, 82, etc., which appear at the output connections 83, 84 of the bridge circuit (Un, au in FIG and a capacitor 86 connected in series therewith, integrated to an integration _{voltage value U 1} at the capacitor 86 (see U- in the course of the voltage Ug ^ at the capacitor 86 in FIG. 5). As soon as the output voltage Ug ,, o /. of the bridge rectifier has dropped to about this integration voltage value (at time t. in Fig. 5), the UJT designated 88 ignites, which is in series with a resistor 89 or 90 as well as the thyristor 87 parallel to the output terminals of the bridge circuit 75 and the ignition electrode 91 of which is connected to the connection between the capacitor 86 and the resistor 85. The UJT is further connected to the thyristor 87 in such a way that it in turn ignites the thyristor 87 when it is ignited, whereby the resonance oscillations 76, 771, 78 etc. following the main pulse 7 ^ are suppressed.

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The thyristor is triggered by the voltage pulse 92 of the voltage U _Q appearing at the resistor 90. This voltage pulse is made by suitable dimensioning of the resistor 85 and the capacitor 86 of such a long duration that it covers the entire remaining resonance oscillation
(to t in Fig. 5) is detected.

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Claims (24)

Claims \ LJ Process for the distributorless ignition of devices to be ignited cyclically, in particular internal combustion engines, in which at least one energy source is discharged via at least one spark gap by a high-voltage pulse, characterized in that the energy source is located on the primary side of a high-voltage transformer (ignition or charging transformer) is and / or charges, alternately allows a current to flow in one direction and a current in the opposite direction, whereby the respective current flow is interrupted between two periods of current flow and the energy source alternately in one and after the subsequent interruption of the current flow in the opposite Direction at least partially discharges, and that one of the at least two spark gaps in the discharge circuit of the energy source when discharging the energy source in one direction blocks and / or short-circuits one of the two spark gaps for one current direction, on the other hand When the power source is discharged in the opposite direction, the other of the two spark gaps blocks and / or short-circuits for the opposite current direction. 2. The method according to claim 1, characterized in that one of the two spark gaps is permanently blocked and / or short-circuited for one current direction and the other of the two spark gaps is permanently blocked and / or short-circuited for the opposite current direction. 509809/0432 3. The method according to claim 1 or 2, characterized in that that one of the two spark gaps consists of a first and a second spark gap. 4. The method according to claim 1, 2 or 3, characterized ei chne t that one resonance vibrations attenuated in the high-voltage transformer. 5. The method according to claim 4, characterized in that that the resonance oscillations in the primary circuit of the high voltage transformer and / or damped by a special damping winding. 6. The method according to claim 5 »marked thereby, that you have the primary circuit of the high-voltage transformer and / or a special damping winding short-circuits during the occurrence of the undesired resonance oscillations. 7. Arrangement for performing the method of distributorless ignition according to one of claims 1 ^ 6, characterized characterized in that a switch arrangement (4, 5 »22, 23ί 36, 37) on the primary side of at least one an energy source forming and / or charging high-voltage transformer (2, 25, 35) is provided and such It is controllable that on the primary side (1, 24, 38) alternately a current in one and a current in the opposite Direction flows and that between two successive periods of the current flow the respective current is interrupted; and that furthermore in the at least two spark gaps (10, 11; 3I, 32; 52, 54, 57, 59) have- 509809/0432 the discharge circuit of the energy source at least one blocking device (9) and / or a Kurzschlussexnrichtung (29) is provided, which the discharge current at least during the discharging of the energy source in one direction for the first spark gap (10) blocks or in the first spark gap (31) short-circuits, so that then only the second spark gap (12 or 32) ignites, and that furthermore at least one blocking device (11) and / or a short-circuit device (30) are provided in the discharge circuit is that the discharge current at least during the discharge of the energy source in the opposite direction for the second spark gap (12) blocks or short-circuits at the second spark gap (32) so that only the first spark gap (10 or 3I) ignites. 8. The arrangement according to claim 7 _f, characterized geken, that each spark gap consists of two series-connected spark gaps (52, 59 and 54, 57). 9. An arrangement according to claim 8, characterized in that one of the two series-connected spark gaps is connected via a blocking device each to one end of the secondary winding (49) of the high-voltage transformer, the blocking devices (51, 58) and 53 or respectively . 36) are switched in such a way that when the energy source is discharged in one (first) direction at each end of the secondary winding a spark gap (52, 59 or 54, 57) is ignited and a spark gap (54, 57 or 52, 59) is blocked, uhd that when the energy source is discharged in the opposite direction, those spark gaps in the first direction 509809/0432 have ignited, are pecked and those spark gaps that were blocked in the first direction ignite. 10. The arrangement according to claim 7 »8 or 9» marked thereby ζ ei c h η e t that as locking devices (9, 11; 51 »53» 56, 58) and / or - as short-circuit devices (29 » 30) diodes are provided. 11. Arrangement according to one of claims 7-10, geken nzeich by a damping device (60) in an electrical and / or magnetic circuit of the high-voltage transformer (2, 25, 35) 12. The arrangement according to claim 11, characterized in that that for damping lossy core material in the high-voltage transformer (2, 25, 35) is provided. 13. Arrangement according to claim 11, characterized in that the damping device (60) is parallel to the primary winding (7 »28, 38) of the high voltage r transformer or to a part of this primary winding or via a separate winding (damping winding) of the high-voltage transformer is switched. l4. Arrangement according to Claim I3, characterized by an ohmic resistor as a damping device (60). 509809/0432 15 · Arrangement according to claim 13t characterized through a voltage-dependent resistor (VDR) as a damping device (60). 16. The arrangement according to claim 13, marked ze ichnet by a capacitor as a damping device (60). 17. Arrangement according to claim 13, characterized by a triac as damping device (60), the control electrode (63) of which is connected to a pulse generator is, which is preferably designed and connected that the triac at the beginning of the second, due to the Discharge of the energy source resulting half-wave (65) is ignited and at least those of the following resonance oscillations (66, 67) short-circuits, which could lead to undesired ignition of a spark gap. 18. Arrangement according to claim 13, characterized by a triac (70) in a dimmer circuit as Damping device (60). 19 · Arrangement according to claim 13, characterized in that that as a damping device (60) a bridge rectifier (75) in connection with a at the outputs (83, 84) connected circuit arrangement is provided which has a parallel to the Outputs (83, 84) lying series connection of a first Resistor (85) and a capacitor (86), as well as a series circuit of a second lying parallel thereto Resistor (89), a UJT (88) and a third resistor 509809/0432 stood (90), and finally comprises a thyristor (87) connected in parallel to both series circuits, ■ where the ignition electrode of the UJT is connected to the junction between the first resistor (85) and the capacitor (86) is connected, and the ignition electrode of the thyristor as the ignition voltage of the third resistor (90) occurring voltage drop is supplied. 20. Arrangement according to one of claims 7-19, characterized characterized in that the switch assembly in the primary circuit of the high-voltage transformer (2, 25 » 35) includes electronic switches. 21. Arrangement according to claim 20, characterized in that that the electronic switches are two transistors (22, 23; 36, 37). 22. Arrangement according to claim 21, dadur 9 hgeke η nz ei ch η et that the collector of one transistor (22, 36) with one end of the primary winding (24, 38) of the high-voltage transformer and the collector of the other transistor (23 _f 37) is connected to the other end of the primary winding, while the emitters of both transistors (22, 23); 33, 3 * 0 are connected to ground and the primary winding has a center tap (lk , 15) which is connected to the pole of the voltage source that is not connected to ground. 23. Arrangement according to claim 22, characterized in that that the base of each transistor (22, 23) has a respective resistor (20, 21) with a transistor 509809/0432 blocking voltage is connected, as well as via a switch (18, 19) each with a transistor switching through Potential, preferably ground, is connected. 24. Arrangement according to claim 22, characterized in that that one of the control inputs (4l, 42), via which the transistors (36, 37) are controlled, Via a series resistor (45, 46) with the base one each of the transistors and the latter each with a Zener diode (43, 44) that keeps the control voltage constant is connected, furthermore a negative feedback resistor between the emitter of each transistor and ground (47 j 48) is provided; so that the current in the primary winding of the high-voltage transformer is independent of the operating voltage Final value reached. 25 · Arrangement according to claim 22, 23 or 24, characterized marked show that the collector of each transistor (22, 23 »39, 40) has a blocking device, preferably a diode (33 »34; 39, 40), with the respective end of the primary winding of the high-voltage transformer is connected so that the blocking device an operation of the transistors in the intended Prevents switching direction opposite current direction. 509809/0432 Blank page