DE2242326A1 - IGNITION SYSTEM FOR COMBUSTION MACHINES WITH A MAGNETIC IGNITER - Google Patents

Description

R. 1 O 54

2 * 1.8.1972 Ws / Mn

Attachment to
Patent application

ROBERT.BOSCH GM3H, Stuttgart

Ignition system for internal combustion engines with a magneto

The invention relates to an ignition system for internal combustion engines with an ignition armature, which is used to generate the ignition energy interacts with a rotating magnet system driven by the internal combustion engine and on its Winding a circuit is connected in which the switching path of a controllable electronic semiconductor element and which is also the primary circuit of an ignition coil forms, the secondary winding of which is connected to at least one spark plug via an ignition cable and where the half " terelenent with its control electrode * ah a control circuit is connected, the semiconductor element from the ignition point by a control signal from a control device current-conducting state reverses in the blocking state.

409812/0073

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BATH ORIGINAL

Robert Bosch GmbH R. 1 0 5- Λ V / s / Mn

Stuttgart

In so-called coil ignition systems, the previously closed primary circuit of the ignition system is activated at the point of ignition by the semiconductor element, preferably by one Ignition transistor open. The magnetic field of the ignition coil built up by the primary current collapses and induces A high-voltage pulse in the secondary winding, which causes an ignition spark on the spark plug.

To generate additional ignition sparks, the primary electrical current circuit must first be closed again. In the case of battery-powered ignition systems, the control voltage required to reverse the ignition transistor can be taken from the battery terminals. With so-called magneto igniters, however, the terminal voltage at the ignition armature is too low with a short-circuited prir circuit to keep the ignition transistor completely in the conductive state, which is necessary to build up a strong magnetic field in the ignition coil or in the ignition armature.

In a known, transistor-controlled magneto ignition system is the ignition transistor with a resistor in the primary circuit connected in series. When a positive voltage half-wave of the ignition armature occurs, the ignition transistor will through the voltage drop occurring at this resistor is switched to the current-conducting state or up to the point of ignition kept in the conductive state. At the point of ignition, the base-emitter path of the ignition transistor is bridged and in this way the ignition transistor is blocked. These or such solutions have the disadvantage that the resistance Primary circuit is loaded in an undesirable manner, especially at high speeds, by having a current limitation and thus only a limited structure of the magnetic field

409812/0073

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BATH ORIGINAL

Robert Bosch GmbH R, 1 0 5 ί Ws / Mn

Stuttgart '

of the ⁱ .vährend causes the positive voltage half-wave in the ignition armature. As a result, the high voltage triggered by the ignition transistor when the primary circuit is interrupted is greatly reduced in the secondary winding of the ignition armature. With regard to the starting and idling speed, the resistance must not be selected too small, otherwise the control voltage required for the ignition transistor will not be available.

The invention is based on the object of a transistor-controlled Build the magneto ignition system in such a way that the level of the primary current to be interrupted at the time of ignition passes through Control elements of the ignition transistor in the primary circuit and

is dependent. This is achieved according to the invention by that the control electrode dec semiconductor element in the primary circuit at least one resistor is connected to one end of a control winding, the other end of which is connected to the Primary circuit is connected and at least when the primary current increases with a changing magnetic flux is chained.

In the simplest case, the control winding with the revolving, driven by the internal combustion engine and designed as a magnet system linked in such a way that the in the ignition armature winding and voltages induced in the aforementioned control winding are in phase. As a semiconductor element a transistor is preferably used.

Details of the invention are at several in the drawing illustrated embodiments explained in more detail. Show it:

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409812/0073

BATH ORIGINAL

- it -

Robert Bosch GmbH R.J 0 5 4 VJs / Mn

Stuttgart? ? Λ? 3 2

1 shows the circuit diagram of an ignition system with a magneto and an ignition transistor in the primary circuit, the base of which is connected to a control winding arranged on the ignition armature.

Pig. 2 shows a simplified magneto, in which the control winding on a Additional anchor is arranged.

Fig. 3 shows the circuit diagram of an ignition system in which the control winding on a light armature of the magneto is arranged and in

Fig. 4 is the control winding part of a primary circuit arranged transformer.

The ignition system of a single-cylinder internal combustion engine shown in FIG. 1 is equipped with a magneto 10, the ignition armature 11 of which is designed as an ignition coil is in that it carries two windings on its iron core 12, one of which is the primary winding 12a and the other is designed as a secondary winding 12b. The attached to the housing of the internal combustion engine, not shown ZüncUanker 11 acts with one of the internal combustion engine Via the crankshaft driven in the direction of the arrow rotating pole wheel 13 together with permanent magnets li »is equipped. While the secondary winding 12b is connected to a spark plug 16 via an ignition cable 15, the primary winding 12a of the ignition armature 11 is connected to one v Primary circuit in which the collector-emitter connector

409812/0073 - 5 -

BATH ORIGINAL

^;: -;: Robert Bosch GmbH _ ■ '' · ..., .- R. ^ ·.? ⁵ ^ V / s / Mn

of a semiconductor element ^ · is arranged. The semi- '. terelemont is .'- as; "NPN Ip ι tender Ztindtransistor Removing 17 · formed, and its emitter terminal is .ebenso, v / ie the öine sin the Primärtiicklün'g '12a _Masäö>:... .'Däs other; ' ■ -EWde ^ de # \. Pri ^ ■ · ■ "'· -

Ignition transistor 47- 'verbunderi. ^ To the burden of the Züridankers "11 while ^ de * 'n' ^ gäi'ί, ν ^ η ^ Spap.nungshatb'wellen .will. ^^^^ Dl add _: -.; *. ■

in series-iiögentian · ^; Against ^ j; äja ^; ^; i ^

sis of the ignition transformer:. "i'f ^ fst're ^ n" vSte ^ ers ^ roinkreis ^ init ■: ■; ' a; SteueEtransistor -ZO attached ^,. its K'oll'ek- \ . gate-emitter path for. Base-emitter path of the ignition, transistor 17 is held in parallel. To trigger the ignition process, a magnetic pulse generator 21 is arranged parallel to the base-emitter path of the control transistor 20, the force line guide piece 2.1a of which is also driven in a rotating manner by the internal combustion engine in the direction of the arrow. The base of the control transistor 20 is also connected via a resistor 22 to the grounded end of the primary winding 12a and via a coupling resistor 23 to the other end of the primary winding 12a. .

On the iron core 12 of the ignition armature 11 there is also a \ _; Control winding 24 is applied, one end of which is connected to the base of the ignition transistor 17 via a resistor 25 'which limits the current at high speeds and the other end of which is connected to the end of the primary winding 12a which is not grounded. Both windings have the same winding sense, so that the voltages induced in them are in phase. ·. '. "' -. ■

- 6 -409812/0073

BATH ORIGINAL

Robert'Bodch GmbH R. ¹ 0 5 U ws / Ifci. .

Stuttgart

The V / irkungswedse this ignition system is such that the rotating magnet wheel 13 of the Masnotzünders jev Eils induced in starting the internal combustion engine or during operation of the machine 30 in the windings of the ignition armature ¹ I / AC voltage. In the primary current circuit, the negative voltage half-waves of the primary winding 1? A are loaded to such an extent via the diode 18 and the resistor 19 that the high voltage induced in the secondary winding 12b is insufficient at high speeds to generate an ignition spark at the spark plug 16. The ignition transistor 17 remains blocked, since its base also receives a negative potential from the control winding via the resistor 25.

At the beginning of each positive voltage half-wave of the primary winding 12a, the in-phase control voltage of the control winding 2k also becomes positive, a base current now begins to flow through the resistor 25, which completely switches the ignition transistor 17 through to the conductive state. This practically short-circuits the primary tronJ and the primary current rises to its peak value during the positive half ν / haste up to the ignition time, whereby a strong magnetic field is built up in the ignition armature 11: At the ignition time, the pulse generator 21 is triggered by the rotating force line guide 2la A voltage pulse is generated which raises the base of the control transistor 20 to a positive potential and thus switches it to the conductive state. As a result, the base-emitter path of the ignition transistor 17 is short-circuited and the current previously flowing to the base via the V / resistor 25 is diverted via the control transistor 20 to ground. By switching off the base current at the ignition transistor 17, its collector-emitter path is immediately blocked

409812/0073 " ⁷ "

BATH ORIGINAL

Robert Bosch GmbH Rj 0 5 4 Ws / Mn

Stuttgart

and thereby the primary current is interrupted. That from the stream The magnetic field built up in the ignition armature now collapses and the flux generated by the rotating permanent magnet and building up in the armature in the opposite direction is induced a high-voltage pulse in the secondary winding 12b, which generates an ignition spark on the spark plug 16.

Since during this process a voltage is also induced in the primary winding 12a and in the control winding 24, It must be ensured that the control transistor 20 also after the decay of the generated in the pulse generator 21 Voltage pulse remains in the conductive state. This is caused by the coupling resistor 23, which causes the primary voltage to rise to the base of the control transistor transmits and thus the control transistor 20 »'a rapid Overdrive continues to be conductive and therefore keeps ignition transistor 17 blocked. Only at the end of the positive The control transistor reaches half the primary voltage 20 again into the blocking range, since its base is connected to its emitter via resistor 22 The following negative voltage half-wave of the primary winding 12a and the control winding 24 is - as already mentioned above mentioned -on the ignition transistor 17 ineffective. Only the next positive voltage half-wave of the control winding 24 switches the ignition transistor 17 again in the current-conducting state. The ignition process is repeated with every full revolution of the force line guide piece 21a, which is attached to the pole wheel 13 the ■ magneto 10 is arranged.

The control winding of the ignition system can just as well be connected to an additional armature 30 spatially separated from the ignition armature 11 be arranged. Such a control winding 31 is in

408812/0073 "

BAD ORfGiNAU

Robert Bosch GmbH R. I 0 5 4 Ws / Mn

Stuttgart

Pig. 1 indicated by dashed lines. Your one end is over the resistor 25 is connected to the base of the ignition transistor 17 and its other end is connected to ground. The order of the additional armature 30 and the winding direction of its control winding 31 is to be selected so that the induced therein Voltage with which the primary winding 12a is approximately in phase. Such an additional anchor 30 acts with his Control winding 31 in the same way as ignition armature 11 with control winding 24.

FIG. 2 shows the greatly simplified structure of a magnetic generator 40 which can be used, for example, for an ignition system according to FIG. 1. Be circulating in the direction of arrow Il flywheel ¹ is mounted on the not visible crankshaft of the internal combustion engine and provided with 42 alternating polarity magnetic four radial permanent magnets, which are arranged distributed symmetrically on the Polradinnenseite over the circumference. An armature plate 43, which is fastened to the motor housing and carries an ignition armature 44, a light armature 45, an additional armature 46 and a magnetic pulse generator 47, is arranged inside the pole wheel 41. Ignition armature 44 and light armature 45 are opposite one another. The additional armature 46 is arranged between each pole piece of the ignition and light armature that it is spatially offset by 90 ° with respect to the ZUndanker 44. It carries a control winding 48, the winding direction of which is selected so that the voltage induced in it is in phase with the voltage induced in the windings of the ignition armature 44. The Imoulsgeber 47 interacts with a non-recognizable force line guide piece, which runs over the pole shoes of the pulse generator 47 once with each full revolution of the pole wheel 41 and

- 9 409812/0073

Robert Bosch GmbH Rj 0 5 4 Ws / Mn

Stuttgart

22A2326

in this way in an ignition system according to Pig. I one Ignition process triggers.

In Fig. 3 is an ignition system for the internal combustion engine of a motor vehicle, which corresponds essentially to the circuit structure of the ignition system according to FIG. The same components are therefore provided with the same reference numbers. In contrast to FIG. 1, the Z-anchor is here 11a of the magneto 10a executed without Steuerwieklung. This is arranged on a light anchor 50, which is also interacts with the pole wheel 13 and its Lichtv / icKlung via a light switch 52 to a lighting system 53 of the motor vehicle is connected. The control loop 53 is connected in series with the light winding 51, whose free end is on ground. The free end of the control winding 53 is through a capacitor 5 *}, a current limiting resistor 55 and a diode 56 connected to the base of the ignition transistor 17. Between the capacitor 5 * 1 and the resistor 55 is one Diode 58 connected to ground on the anode side. Furthermore, the end of the primary winding that is not connected to ground 12a of the ignition armature 11a via a current-limiting resistor 57 to the base of the ignition transistor 17 connected.

Correct spatial arrangement of the two anchors 11a and 50 of the igniter 10a or by the correct winding direction of the control winding 53 is achieved that the in the control winding 53 and light winding 51 during operation of the internal combustion engine induced voltage with the voltage the primary winding 12a is almost in phase. As

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409812/0073

BATHROOM QRiGiNAl

Robert Bosch GmbH Ws / Mnt 0 5 4r,

Stuttgart

already explained with reference to FIG. 1, the ignition transistor remains when a negative voltage half-wave occurs in the Primary winding 12a blocked. .The same time in the control winding 53 and light winding 51 occurring negative 3voltage half-wave however, charges the capacitor through diode 58- 5'J on. At the following positive voltage half-wave the control winding 53 is this with the voltage of the charged capacitor 5'4 connected in series and the total voltage drives a base current via the resistor 55 and the diode 56, which drives the ignition transistor 17 completely switched through into the current-conducting area. Since at the same time in the primary winding 12a If a positive voltage half-wave occurs, this drives one in the practically short-circuited primary circuit strong current, which is interrupted at the ignition point, in that a control pulse from the pulse generator 21 switches through the control transistor 20 and thus the base-emitter line of the ignition transistor 17 bridged, whereby this is blocked immediately. That in the ignition armature 11a from the primary hearing current strong magnetic field built up now collapses, so that in the secondary winding 12b to generate a Ignition spark at the spark plug 16 required high voltage pulse is induced. Since the capacitor is 5 * 1 now discharges via the control transistor 20, it is disconnected from the subsequent negative voltage half-wave of the control winding 53 recharged. The ignition process can therefore start with every full period of the voltages in the ignition and repeat the light anchor or with each full revolution of the pole wheel 13.

The control winding 53 is designed so that in the event of a defect at the capacitor 54 this can be bridged. the then at the base of the ignition transistor .17 only effective positive voltage half-wave of the control winding 53 and light

4098 12/0073 _ _la _

"....,. ._ BADtOBlGiNAL

Robert Bosch GmbH R. 1 0 5 4 Ws / Mn

Stuttgart

Winding 51 is sufficient to switch the ignition transistor 17 completely into the current-conducting state.

If the control winding 53 fails z. B. by Windunes conclusion - The line development 51 serves as a control winding. This is indicated by the connection 59 drawn in dashed lines. With this circuit however, the capacitor 54 'should be intact since it the positive voltage effective at the base of the ignition transistor 17 increases significantly.

The ignition system shown in Fig. 3 is designed so that even with total failure of the light armature 50 with reduced ignition voltage and slightly increased starting speed the internal combustion engine continues to work. In this case, the flow for reversing the ignition transistor 17 required base current via a second control path from the primary circuit via the resistor 57 to the base of the ignition transistor .17. The diode 56 prevents this a drainage of the control current into the lighting system.

Fig. -4 shows another simplified compared to FIG Embodiment of the ignition system according to the invention ;, at which the control winding is designed as a transformer 60. The same components are provided here with the same reference numbers. The transformer 60 is located with its primary winding 60a in the primary circuit of the ignition system and its secondary winding 60b is with one end over a current-limiting Resistor 6l connected to the base of the ignition transistor 17, while its other end is connected to the primary circuit connected.

-. 12th

409812/0073

BATH ORIGINAL

Robert Bosch GmbH R. t 0 5 4 Ws / Mn

Stuttgart

When operating the internal combustion engine are - as already to Fig. 1 explains in more detail - the negative voltage half-waves ineffective at ignition transistor 17. At the start of a positive The positive potential first reaches a voltage half-wave via the secondary winding 60b of the transformer 60 and via the resistor 6l on the basis of the blocked ignition transistor " stors 17. Since its emitter is firmly at ground potential, the "collector-emitter path of the ignition transistor 17 at first a little bit -stron; conductive. The current in the primary circuit the ignition system now begins to flow. This current then builds up a magnetic field in the transformer and the change in the magnetic flux (d // it) is generated in the secondary winding 60b of the transformer 60 a voltage. The transformer 60 is now connected so that when the primary current increases voltage induced in its secondary winding 60b with its positive potential via resistor 61 at the base of the ignition transistor 17 ■ becomes effective in that it increases the base current and thus the ignition transistor 17 continues to control the current-conducting state. The increase in the base current in turn requires an increase in the primary current, so that a positive feedback between the primary flow and the base flow is achieved. The resistor 6l is used to limit the base current at high speeds. Another advantage of this circuit is the effect of the secondary winding 60b when the primary current is interrupted at the ignition point, which is caused by the Pig. I further explained blocking of the ignition transistor 17 is triggered by the pulse generator 21. Then that is in secondary winding 60b of the transformer 6o generated voltage opposes the voltage peak occurring in the primary circuit and thus limits the Control current derived via the control transistor 20.

0 981 2/010 ^

BATH ORIGINAL

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Robert Bosch GmbH R.I. 0 5 4? "Ws / Mn

Stuttgart

The invention is not restricted to the exemplary embodiments shown, but also includes circuit arrangements in which individual components can be designed differently. But is substantially ₃ that the semiconductor element over the entire DrehζahIbereich is completely switched to the stronleitenden state upon the occurrence of the positive voltage half-waves in the primary circuit by the control voltage is provided to the semiconductor element by a Steuerwicklüng to the extent that even at low speeds of the internal combustion engine or of the magnet system 10 a sufficient reversal of the semiconductor element is achieved. Instead of the ignition transistor 17 can, for. B. the semiconductor element can also be constructed as a double transistor in a known Darlington circuit. The control transistor 20 can also be replaced by a thyristor, a thyristor ^ trode or a triac, the positive feedback via the resistors 22 and 23 possibly being omitted. A further change in the circuits according to FIGS. 1-4 is possible within the scope of the present invention in that the ignition coil is arranged separately from the ignition armature 11 at a different point in the primary circuit. Finally, the control winding can also be wound on a secondary armature arranged over the ignition armature or light armature.

409812/0073

Claims (16)

Robert Bosch GmbH R) 0 5 4 v / s / Mn claims 1.) Ignition system for threshing machines with an ignition armature, dor for generating the ignition gate, ie with one of the internal combustion engine driven, rotating magnet system acts together and a circuit is connected to the winding, in which the switching path of a controllable electronic semiconductor accelerator and which is at the same time the Priirrirstromkreio an ignition coil, the secondary winding of which is via an ignition cable is connected to at least one spark plug and wherein the semiconductor element with its control electrode to a Control current circuit is connected, which through the ignition point a control signal of a control device reverses the semiconductor element from the current-conducting state to the blocking state, thereby characterized in that the control electrode of the semiconductor element (17) via at least one resistor (25) with the one end of a control winding (24) is connected, the other end of which is connected to the primary circuit and the at least when the primary current rises a with a changing Magnetic flux is concatenated. 2. Ignition system according to claim 1, characterized in that the one end of the control winding (24) via at least one resistor (25) connected to the base of a semiconductor element designed as an ignition transistor (17). - 15 409812/0073 BATH ORIGINAL - 15 Robert Bosch GmbH R. 1 0 5 4 Ws / Mn stuttgart 22A23 3. ignition system according to claim 1 or. 2, characterized in that that one end of the control winding (53) about raihei. a diode (56) and a resistor (55) with the control electrode of the semiconductor element (17) -connected is. . .- ■ * i. Z undan la ~ e after ^; ei ne m der-address 1 - 3, characterized by - ........ -, d-aP> the one end-of the control winding, (53) via earth destc: ns · a capacitor (-54) a V / ider st and (55) ini ^: t is connected to the control electrode of the semiconductor element (17). . ... 5. 'Zün'danilage. = According to claim H, characterized in,. · '■ that between-the-V / resistance- (55) and the capacitor. -05 ^ f) a diode (58) connected to the anode at ground level. .-.---. ■■. . . .-. 6. Ignition system according to one of claims 1, ^ - 5, -durch- ge _; indicates that the other end of the control winding (31) - "'" * ■ miitödtJin at' ground 'end. the ignition armature winding. • - ^; "-"<l'2.a; 0 is connected '....;.; ■ = -. »-, (- .. ■ '. ■ -, ■ ■■ -. BATH ORIGINAL - 16 - Robert Bosch GmbH R. 10 5 4 ws / mn 7. Ignition system according to one of the claims, characterized in that that the end of the ignition armature winding (12a) not lying on Hasse via a resistor (57) with the Control electrode of the semiconductor element (17) connected is. 8. Ignition system according to one of claims i - 5, characterized characterized in that one end of the control winding (2'I) with the end of the ignition armature twisting that is not at ground level (12a) is connected. 9. Ignition system according to one of claims 1-8, characterized in that the control winding (21) with the rotating magnet system simulated as a pole wheel (13) is chained. 10. Ignition system according to claim 9, characterized in that the control winding (24) is applied to the iron core (12) of the ignition armature (11) and that the ignition armature winding (12a) and the control winding (2H) have the same winding direction . 11. Ignition system according to claim 9, characterized in that the Steuerv / icklung (Ί8) is arranged on an additional armature (i | 5). 4 0 98 12 / 007P - 17 - BATH ORIGINAL - 17 Robert Bosch GmbH R. 10 5 4 V / s / Mn 12. Ignition system according to claim 6, characterized in that the additional armature (46) is spatially offset by 90 ° in relation to the ignition armature (11). 13. Ignition system according to claim 9 or 11, characterized in that that the control winding (53) is arranged on a light armature (50). 14. Ignition system according to claim 13, characterized in that that the light winding (51) connected to a lighting system (53) forms the control winding. 15. Ignition system according to claim 13, characterized in that the light winding (51) with a light on the ker (50) additionally applied control winding (53) is connected in series. 16. Ignition system according to claim 1 or 2, characterized in that the control winding is designed as a transformer (60), the primary winding (60a) of which is in the primary atomic circuit and the secondary winding (60b) with one end via a resistor (6l) to the control electrode of the Semiconductor element it (17) and is connected at the other end to the primary circuit. A.0 9-11-2 / 0-0 7 3 - BASS ORIGINAL