DE2059346A1 - Ignition system for spark-ignited internal combustion engines - Google Patents

Description

PA TBN TA N M / AL TS

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TEL. 03.1. 762907. TELEGR. PROP ₁ NDUS. TELEX 0.84057 _TE L SS

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22 338/22 348 Berlin, November 24, 1970

RE. Phelon Company, Inc.,

East Longmeadow, Mass. (V.St.A.)

Ignition system for spark-ignited internal combustion engines

The invention relates to an ignition system for spark-ignited internal combustion engines and, in particular, deals with a trigger magnet and coil assembly for use in an interrupterless ignition system employing a permanent magnet alternator includes.

Several different types of breakerless ignition systems are known in the art. They will be the usual ones Breaker contacts replaced by a transistor, a controlled silicon rectifier, a thyratron or another electronic, somehow controlled by a trigger signal Counter. These systems are generally more reliable than the corresponding mechanical breaker systems and usually have a longer service life because they are less subject to mechanical wear and tear and destruction. One such The system is described in U.S. Patent 3,465,739.

In the system disclosed there is a trigger magnet and - Coil unit arranged adjacent to a rotating part of the motor. A series of tenons, ribs, or other irregular

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on the rotating part work with the coil and magnet assembly together to provide a magnetic flux circuit through the coils, the reluctance of which changes in such a way that if the pegs, ribs or other irregularities pass the coil and magnet unit, a trip signal is induced in the coil. The trigger signal of the coil is the control electrode of a controlled ^ zium rectifier supplied in order to switch it on at the right time within the engine work cycle. When the controlled silicon rectifier is switched on, a high voltage is applied to the spark plug or other spark gap ignition device fed to generate a spark in the spark gap. Two or more of these irregularities are generated a pre-ignition used. As shown in this patent specification, the rotating part of the motor to which the trip magnet and coil unit is disposed adjacent to be the rim of the rotor of a permanent magnet alternator, the contains a turn for supplying energy to the ignition system.

The trip magnet and coil unit according to the invention is a modification of that in the above-mentioned patent specification disclosed magnet and coil unit. If the magnet and coil unit adjacent to the cited patent the rim of the rotor of a permanent magnet alternator is used, the rim of the rotor must be made of iron or made of a different magnetic material so that the stray field generated by the alternating current magnets on is limited to the extent that it has no effect on the trip coil. That is, if the stray field is too large it can induce sufficiently high voltages in the trip coil to cause the trip coil to trip at incorrect times Engine work cycle - to be initiated in particular at higher engine speeds. The trigger magnet and coil unit after

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of the invention can be used with a permanent alternator in which the rotor, with the exception of those carried by it Permanent magnet unit, made of aluminum or other non-magnetic material, and the stray field the AC generator magnets have little effect on the output voltage generated by the trip coils.

The general object of the invention is therefore to provide an improved one To provide a trip magnet-coil unit for use in an interrupterless ignition system which has a permanent magnet alternator includes

The invention consists in a trip magnet and coil unit for generating a trigger voltage for an electronic switching device, such as a controlled silicon rectifier, in the case of an uninterruptible ignition system that uses a permanent magnet alternating current generator with a Includes rotor carrying permanent magnets. The trigger magnet and coil unit is located near the rotor, and protruding irregularities on this, its hub or any other part rotating with it past the release magnet and coil unit and induce a voltage in two separate coils of the unit. Two or more irregularities or protrusions are used to provide pre-ignition. The induced voltage is sent to the electronic switch of the trip system supplied, whereby a voltage is provided on the spark plug or other spark gap device used c The trip magnet and coil assembly is included a permanent release magnet, a laminated one, to which Trigger magnets are attached to the iron core and the two aforementioned coils that are wound onto this core. The spools and the core are in the manner of the stray field of the alternating current generator magnets arranged that each essentially

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receives the same instantaneous voltage induced by such leakage flux, and they are electrically connected in series with one another, in such a way that the voltages induced in the two coils by the leakage flux are mutually exclusive compensating cascading relationship, while the induced therein by the field of the release magnet Voltage in mutually supporting series connection to one another. Accordingly stand out the voltages induced by the leakage flux are mutually exclusive and they have little effect on the output voltage appears on the two coils.

In the drawing show:

Fig. 1 is a perspective, partially sectioned illustration of the spark ignited Internal combustion engine equipped with a permanent magnet alternating current generator and an ignition system is that a trip magnet and coil unit used according to the invention;

2 shows a vertical section through the alternating current generator rotor 1 along a plane directed perpendicular to its axis, the turns of the alternating current generator stator are shown schematically.

3 shows a vertical partial section through the rotor according to FIG. 1 along a plane which contains the rotor axis and illustrates the trip magnet and coil assembly in side view;

FIG. 4 is a circuit diagram of the ignition system of the internal combustion engine according to FIG. 1;

Fig. 5 is a schematic view to illustrate the The way in which the two coils of the release

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Magnet and coil unit according to Fig. 1 are electrically connected to one another, the direction of the Turns opposite to the path of the triggering magnetic flux and the path of the leakage flux of the alternating current generator magnets is illustrated;

6 shows a vertical section along a plane containing the rotor axis, with an alternating current generator is illustrated in which a second embodiment of the trip magnet and coil unit according to of the invention illustrated in side view, and

FIG. 7 shows a partial section along the line 7-7 according to FIG. 6

Looking at FIGS. 1, 2 and J, and first FIG. 1, this shows a fragmentary spark-ignited internal combustion engine 1 which includes a permanent magnet alternating current generator, indicated generally at 17. the ignition system for the internal combustion engine 1 includes a trip magnet and coil unit 2 mounted outside and adjacent to the rim 31 of the alternator 18. This tripping magnet and coil unit can be part of a larger unit, which is indicated by the dashed lines 4 in Fig. 1, and other parts of the ignition system which are suitably attached to the adjacent stationary part of the machine, includes. The unit 4 can for example consist of a body made of plastic in which the trigger magnet and coil unit and other parts of the ignition system are inserted, but the unit 4 comprises apart from the trigger magnet and coil unit 2, does not specifically form part of the invention, and it can vary widely in construction and shape.

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The trigger magnet and coil unit 2, as best from Fig. 3 can be seen, comprises a cylindrical magnet 3 and a core, which consists of laminated iron legs 5 and 7, which by a bolt or other fastening means passing through the legs and the magnet are attached to the ends of the magnet 3. Two separate trip coils belong to this unit and consist of one first coil 9, which is wound around the leg 5, and a second coil 11, which is wound around the leg 7. The two Coils 9 and 11 are coincident or substantially coincident with each other so that they receive substantially equal voltages induced therein, and how explained in detail later, they are electrically connected to one another in series.

The illustrated alternating current generator 17 is or can be a permanent magnet alternating current generator of generally conventional design of the type used in spark-ignited internal combustion engines, and * he contains a stator 25 which is attached to a stationary part of the machine is attached, as well as the rotor 18, which is seated on a shaft 29. The shaft 29 runs in synchronism with the internal combustion engine around and the crankshaft and camshaft can be the same · In any case, the shaft 29 is one that with a speed which is directly related to the speed of the engine crankshaft, so that a given angular displacement of the crankshaft leads to a corresponding angular adjustment of the alternating current generator rotor. The rotor has one central hub 35tund ring 31 is with this hub by a radially directed disc connected. The stator 25 is inside the rotor in the space between the hub 35 and the rim 31 and comprises a core 24 of laminated magnetic material, the twelve equally angularly spaced apart.

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dial has outwardly extending poles 21. Eleven of Poles 21 take associated windings 23, each of which is relatively one has a small number of turns of relatively thick wire, and these windings are connected in series, to provide a source of alternating current power to a load 41 as shown in FIG. The load 41 can, for example, represent a charging circuit for a battery, which is used to start the internal combustion engine, and / or a lighting or other electrically operated Auxiliary circuit. The twelfth pole 21 accommodates a winding 39 consisting of a large number of turns, e.g. 4000 turns, made of relatively thin wire. This winding is used to provide a high voltage source for the Provide ignition system 40 according to FIG.

To create a magnetic flux field for inducing voltages in To provide the stator windings 23 and 39 of the alternator, six magnet units are embedded in the rotor ring 31. Each of these magnet units consists of two pole pieces 19 and one polarized in the tangential direction Permanent magnets 20. The two pole pieces 19 see one Row of twelve alternately magnetically polarized pole faces on the inner surface of the rotor ring. It is therefore It can be seen that alternating voltages are induced in the various stator coils 23 and 39 as the rotor 18 rotates. The voltage induced in coil 39 is, of course, relatively high compared to that in each of the others Coils 23 is generated. During normal operation, the rotor 18 is driven by the internal combustion engine in the direction of Arrow 22 kept in circulation.

Apart from the magnet units, the rotor 18 can be made from

a non-magnetic diecast material such as aluminum or an aluminum alloy | exist. If such non-magnetic material is used for the rotor, it is limited the flux of the magnets 20 does not, and a considerable stray

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field emanating from the magnets 20 is generated around the rotor and in its vicinity. The general nature this stray field in the area surrounding the outer circumference of the rotor is generally determined by the flux lines of force 33 illustrated in FIG.

Fig. 4 shows the ignition system of the internal combustion engine 1 of Fig. 1. This system uses the trip magnet and coil assembly 2 and is otherwise generally similar to that illustrated and described in U.S. Patent 3,465,739. As can be seen from FIG. 4, the ignition system is generally designated 40 and comprises the coil 39, a diode 45 connected to the coil, a diode 47, a capacitor 43, a controlled silicon rectifier 49, the coils 9 connected in series and 11 of the trip magnet and coil unit, a step-up transformer 50 and a spark plug ^. The transformer 50 has a primary winding 51 and a secondary winding 53. The capacitor 43 is charged via the diode 45 during the positive half-cycles of the voltage induced in the coil 39. Diode 47 is used as a blocking diode to block the discharge of capacitor 43 back through coil 39. When the silicon controlled rectifier is turned off, the capacitor 43 is charged and remains charged until the silicon controlled rectifier is switched to an on or conductive state. When the silicon controlled rectifier 49 is switched on, the capacitor 43 is discharged through the primary winding 51 of the transformer 50, and a high voltage is again generated in the secondary winding 53, so that the spark plug 55 generates a spark.

The triggering of the controlled silicon rectifier 49 is controlled by the trigger coils 9 and 11, which are between his Control electrode and cathode are connected in series.

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As explained in detail later in connection with FIG. 5, the two coils 9 and 11 are connected to one another in such a way that they are generated in them by the flux of the trip magnet 3 Tensions are in a series-connected, mutually supportive relationship, so that they are related to one another add and between their opposite ends, i.e. between the control and cathode terminals of the controlled silicon rectifier, produce a voltage equal to approximately twice that induced in each of the coils Tension is.

The trigger magnet 3 and the magnet core legs 5 and 7 can be seen a magnetic flux field that passes through the coils 8 and 11 and illustrated by dashed lines 12 in FIGS. 3 and 5. The size of this magnetic flux that flows through the Coils 9 and 11 flowing depends, among other things, on the reluctance of the magnetic circuit between the inner ends of the core legs 5 and 7, and irregularities are provided on the rotor rim 31, so that this reluctance substantially at different Rotor positions is different. In the embodiment of the invention illustrated in FIGS. 1, 2 and 3 exist the irregularities on the rotor ring to change the reluctance of the flux circuit between the ends of the release magnet core legs 5 and 7 from rectangular rods 13 and 15 made of magnetic material, which on the rotor ring 31 are attached. The two bars 13 and 15 extend in the axial direction of the rotor ring and are arranged so that they bridge the space between the core legs 5 and 7 in the axial direction, and each rod protrudes from the surface of the rotor ring radially outwards. The rods 13 and 15 have essentially the same axial length and in the circumferential direction extending width, but the foremost bar 13 is substantially radially shorter than the rear bar 15.

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In the illustrated case, the rods 13 and 15 are in Umf ι

far away.

in the circumferential direction of the rotor rim about 20 ° apart

The direction of rotation of the rotor 18 is indicated by the arrow 22 in Fig. 2 illustrates. Therefore, with each revolution of the rotor, the shorter, front rod 13 goes first under the release magnet core legs 5 and 7 and then 20 ° later the larger, rear rod 15. When the shorter rod 13 under the Core legs, the reluctance of the flux circuit between their inner ends is reduced by a certain amount, and a small voltage wave is induced in the coils 9 and 11. When the larger rod 15 later under the core legs passes, the reluctance of the flux circuit between their inner ends is further decreased, and a larger tension wave is induced in coils 9 and 11.

The peak voltage induced in coils 9 and 11 Stress waves when the rods 13 and 15 are under the trigger magnet and - Coil unit 2 go through depends on the rate of change of the reluctance of the tripping magnetic flux circuit and thus on the speed of the rotor. The height of the rod 15 and other parameters are chosen so that even at low engine speeds in the coils 9 and 11 at the moment of the passing of the Rod 15-- voltages induced under unit 2 are sufficient to switch on the controlled silicon rectifier 49 and thereby causing a spark to jump over the spark gap of spark plug 55. The rod 15 in turn is on the Ring 31 of the rotor so arranged that when it is under the unit 2, the crankshaft of the internal combustion engine is at or is close to their top dead center position. At higher rotor and machine speeds, there is a larger voltage wave induced in coils 9 and 11 by the shorter rod when it passes under unit 2, and

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the height of the rod 13 and other parameters of the system again chosen so that at or near a predetermined machine speed the in the coils 9 and 11 through the passage of the shorter rod 13 induced voltage is sufficient to trigger and switch on the controlled silicon rectifier 49, When the shorter rod 13 is approximately 20 ° in front of the larger rod 15, the ignition of the spark plug occurs This higher rotor speed corresponds to approximately 20 ° before the position in which the ignition occurs at low engine speeds entry. A 20 pre-ignition was of course only given here as an example, and different ones can be used Advance angles can easily be obtained by changing the distance between the two rods 13 and 15. It is can also be seen that, while the irregularities as axially extending rods made of magnetic Other shapes and configurations of the irregularities can be used to reduce the reluctance of the material Change the triggering magnet flux circuit if these irregularities pass the release magnet and coil unit. There can also be a large number of circumferentially spaced apart Irregularities can be used, if desired, to set different pre-ignition angles at different Provide speeds, as described in detail in the aforementioned US Pat. No. 3,465,739.

The construction of the release magnet and coil unit 2, such as described above has the additional important advantage that it uses the action of the flux field of the alternating current generator magnets 20 reduced, so that the rotor are mainly made of a non-magnetic material and / or the The need for magnetic shielding between the rotor and the trip magnet and coil unit can be avoided can. The manner in which this benefit is achieved can best be appreciated by considering FIG schematically the physical arrangement / direction of the winding

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ment of the two coils 9 and 11 compared to that of the trigger magnets generated flux field and the leakage flux field generated by the alternator magnets 20 illustrated.

5 is the flux field generated by the trigger magnet indicated by the dashed line 12 and the stray fluid field generated by the alternating current generator ^ magnets 20, as occurs with a position of the rotor by the coils 9 and, by the lines 33. The arrows on these lines indicate the directions of the field at the instant illustrated. As can be seen, the flow of the moves through the Trigger magnet generated field 12 downwards opposite the coil 9 and upwards opposite the coil 11, and these two coils are in turn wound on the corresponding cores 5 and 7 in this way and interconnected that they are interconnected with respect to the field 12 in series and in a reinforcing manner are. On the other hand, it should be noted with regard to the stray field 33 that the flux of this field with respect to the two coils 9 and 11 moves downwards, and that therefore with regard to this field the two coils 9 and 11 in relation to one another Series and mutually canceling relationship are connected. It is particularly important to note that with regard to the a trigger coil (coil 9) the fluxes of the two fields move in the same direction, and with respect to the other coil the fluxes of the two fields in opposite directions, and that as long as the coils are so arranged that such a condition is obtained, they are so wound and that can be connected to an addition of the triggering magnetic flux generated voltages and a cancellation of the alternator magnet leakage flux voltages achieved will.

Accordingly, those in coils 9 and 11 from the triggering magnetic field add up 12 induced voltages to each other and generate at the opposite ends of the coils a tension that is approximately twice that of each

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the voltage generated by the individual coil is, however, strive the voltages generated by the leakage flux field in the coils 9 and 11 thereafter cancel each other out and therefore none notable - to generate output voltage at the two opposite ends of the coils. The possibility of induction sufficiently high voltages in the trip coils due to the leakage flux field to trip the controlled silicon rectifier at an incorrect time, it is drastically reduced, if not completely eliminated. Around a cancellation of those in the coils 9 and 11 from the leakage flux of the magnets 20 induced voltages, the coils 9 and 11 should be arranged so that the through this leakage flux passing through both coils is substantially in the same direction and from substantially the same Size is as indicated in FIG. 5. This can be achieved by such an arrangement of the coils, if these with a rotor, as shown, can be used so that their axes are spaced apart and parallel to each other and lie essentially in a plane passing through the rotor axis.

In Figs. 1, 2 and 3 is the trip magnet and coil unit 2 illustrates arranged outside the alternator rotor near its rim. However, this arrangement is is not essential to the invention and other arrangements of the trip magnet and coil assembly can be used if desired be used. For example, Figures 6 and 7 show the trip magnet and coil assembly near the hub of the alternator rotor. The apparatus illustrated in these figures is the alternator and the trip coil and magnet assembly essentially identical to those of FIGS. 1, 2 and 3, and its various parts have the same reference numerals as

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used in the latter figures, and need not to be described again. An exception to this, however, is the fact that the alternator rotor after Fig. 6 comprises an axially elongated hub 34a, which extends in the axial direction, radially projecting Magnet bars 13 and 15 carries. The trigger magnet and -Scoil unit 2 is in turn arranged near the hub 35a in the vicinity of the rods 13 and 15, so that this pass under the ends of the core legs 5 and 7 with each revolution of the rotor to release tension in the trip coils 9 and 11 to be generated in the same way as already described above in connection with the device according to FIGS. 1, 2 and 3 became. In this case, the unit 2 is arranged in that part of the stray flux field of the alternating current magnets, which is extends radially inward, somewhat to one side of the rotor ring 31, but the effect is the same as in accordance with FIG. 5. That is, the leakage flux tends to flow in the same direction through the two coils 9 and 11 and thereby in These coils induce voltages which cancel each other out, since the coils are in series and in an opposing relationship for such voltages are connected.

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Claims (10)

Patent claims: Interrupterless ignition system for spark-ignited internal combustion engines, characterized by a permanent magnet alternating current generator (17) with a rotating in synchronism with the internal combustion engine (1) Rotor (18), the at least one permanent magnet generating a stray field (33) in the vicinity of the rotor (18) (3) Contains, a spark gap ignition device (55), means which an electronic switching device (49) to cause a spark to occur at the spark gap igniter (55) when the Switching device (49) is switched from a first to a second state, a release magnet (3), two Tripping coils (9, 11) which are arranged near the rotor (18) so that they are within the stray field, Means for generating a circuit for the flux of the tripping magnet (3), which flows through the two tripping coils (9, 11) goes and has a reluctance that changes during the rotation of the rotor (18) that different voltages in the Trip coils (9 »11) induced at different angular positions of the rotor by the flux of the trip magnet (3) with the two tripping coils (9, 11) facing the stray field (33) and the field of the tripping magnet (9, 11) are arranged so that the flux of the stray field (33) and the flux of the trip magnet in one of the trip coils (3) move in the same direction with respect to the axis of this coil and the flux of the stray field in the other trip coil (33) and the flux of the trip magnet (3) with respect to the axis of this coil in opposite directions wander, and the two trip coils are connected in series so that the - 16 - 109823 / 13U Flux field induced voltages in series-connected, weakening relationship to each other, while the voltages induced therein by the tripping magnetic flux in one behind the other, more supportive Are related to each other, with means for connecting the trip coils (9, 11) to the electronic switching device (49) are provided in such a way that the latter trigger signals for their switching between the first and the second state. 2. Ignition system according to claim 1, characterized in that that the two trip coils (9, 11) with their axes in one through the axis (29) of the rotor (18) horizontal plane. 3. Ignition system according to claim 1, characterized in that the release magnet (3) and the two tripping coils (9, 11) form parts of a tripping magnet and coil unit (4) which are attached to the stationary part the internal combustion engine (1) is attached. 4. Ignition system according to claim 3, characterized in that the tripping magnet and coil unit (4) a core consisting of magnetic material and comprising two legs (5, 7) lying apart contains, whose legs (5, 7) lie essentially in a plane passing through the axis of the rotor (18) and each of which receives one of the trip coils (9, 11). 5. Ignition system according to claim 4, characterized in that the one flux circuit for the trigger magnet (3) the means providing at least one elongated magnetic irregularity (13, 15), which in - 17 - 109823 / UU essentially in one through the axis of the rotor (18_ going level is arranged, the release magnet (3) and the two release coils (9, 11) as parts of the Trip magnet and coil unit (4) near the circuit away the irregularity (13, 15) are arranged, and the legs (5, 7) of the core of the release magnet (3) to extend to the orbit of the irregularity (13, 15) in such a way that in the passage of the latter at the legs (5, 7) the reluctance of the flux path between the ends of the legs is momentarily changed. 6. Ignition system according to claim 5, characterized in that that the elongated, magnetic irregularities (13, 15) protrude radially outward and axially extending strips of magnetic material. 7. ignition system according to claim 5, characterized in that that the rotor (18) has a longitudinally extending hub in the axial direction? (35) includes, and that the elongated, magnetic irregularity (13, 15), which protrudes radially outward and is in comprises axially extending strips of magnetic material, arranged on the hub (35) of the rotor (18) is. 8. Ignition system according to claim 5, characterized by at least one permanent magnet (20) a plurality of a circumferential row of magnets attached to the rim of the rotor (18), which are spaced apart in the circumferential direction and magnetized in the tangential direction. 9. Ignition system according to claim 1 to 8, characterized in that - - 18 - 109823 / 13U indicates that the rotor (18) has a ring made of non-magnetic material. 10. Ignition system according to claim 1, characterized in that the rotor (18) has a at least one ring that carries permanent magnets (20) and one that extends longitudinally in the axial direction Has hub (35), the means for generating a circuit for the flux of the tripping magnet (3) at least a strip (13, 15) of magnetic material, which at a point along the circumference of the hub (35) is attached, and the two trip coils (9, 11) are parts of a trip magnet and coil unit (4), which is disposed adjacent the hub (35) and includes a core of magnetic material close to two the path of the strip (13, 15) axially spaced apart, radially inwardly extending legs (5, 7) each carrying one of the trip coils (9, 11), in the Way includes that when the strip (13i 15) passes under the legs (5, 7) the reluctance of the flux circuit is changed between these. Wb / Pe - 22 338 109823 / 13U