EP3834216B1 - Arrangement for the integration of an ignition coil and a band-pass filter - Google Patents

Description

FIELD OF THE INVENTION

The present invention relates to an arrangement for integrating an ignition coil and a bandpass filter.

The present invention also relates to an arrangement for feeding a high-frequency voltage into an ignition coil.

TECHNICAL BACKGROUND

Devices for igniting a fuel mixture, in particular a fuel-air mixture, are used in automobiles. The prior art teaches a variety of designs for such devices. Here, the combustion process in the combustion chamber of the engine, in particular an internal combustion engine with spark ignition by means of spark plugs, also known as an Otto engine, needs to be further improved.

An ignition system or an ignition coil transforms the battery voltage of a vehicle to the desired ignition voltage in order to provide an ignition signal or an ignition voltage, in particular a high-voltage ignition voltage.

The U.S. 2015/0200051 A1 discloses several variants of a transformer in which an ignition pulse generated on the primary side is transformed into a high-voltage ignition pulse on the secondary side of the transformer.

It is also known from the prior art to ignite a fuel-air mixture, as an alternative to generating a pure high-voltage ignition voltage, to use a high-frequency plasma ignition device which generates a high-voltage ignition voltage with a superimposed high-frequency voltage.

The DE 10 2015 210 376 A1 and alternatively the DE 10 2013 207 909 A1 each disclose, for example, such a high-frequency plasma ignition device. Herein, a high-voltage pulse generated in an ignition coil is electrically coupled with a high-frequency voltage generated in a high-frequency power source.

A bandpass filter is connected between the coupling point and the high-frequency voltage source. This bandpass filter is implemented as a series resonant circuit consisting of a coil and a capacitor. The capacitor blocks the DC component of the high-voltage pulse from the high-frequency voltage source. The series resonant circuit is dimensioned in such a way that, on the one hand, it is permeable to the high-frequency voltage and, on the other hand, it blocks harmonic components of the high-voltage pulse and the ignition noise.

Coils and in particular high-frequency coils, such as those used in bandpass filters, represent components that require a comparatively large amount of space. The space in the engine compartment, especially in the area above the cylinder bank, is typically not sufficient for this. A spatial separation of the ignition coil and the bandpass filter in two separate housings also requires considerable effort in the design Insulation in the connection line between the two housings and in the required housing connectors with regard to high-voltage strength.

This is a condition that needs to be improved.

SUMMARY OF THE INVENTION

Against this background, the object of the present invention is to create an ignition coil that is as compact as possible, in which a high-voltage pulse with a superimposed high-frequency voltage is generated.

According to the invention, this object is achieved by an arrangement for integrating an ignition coil and a bandpass filter with the features of claim 1.

The finding/idea on which the present invention is based is to integrate the coil of the bandpass filter into the ignition coil in the most space-saving manner possible.

For this purpose, the coil of the ignition coil arranged on the secondary side, which is referred to below as the second coil, is electrically connected to a further coil, which is referred to below as the third coil and represents the coil of the bandpass filter. In addition, a high-frequency terminal that receives a high-frequency voltage is electrically connected to the second coil and the third coil. The high-frequency connection receives a high-frequency voltage from outside the sink, in particular from a high-frequency voltage source connected to the high-frequency connection, and feeds the high-frequency voltage into the ignition coil.

The coils of the ignition coil and the bandpass filter can thus be positioned spatially close to one another, and an ignition coil with an integrated coil of a bandpass filter can thus be realized with a reduced space requirement. In addition, this creates an ignition coil in which an electrical coupling of a high-voltage pulse generated in the ignition coil on the secondary side with a superimposed high-frequency voltage is realized. The thus in the ignition coil The high-voltage pulse generated with superimposed high-frequency voltage is electrically decoupled from the ignition coil at a connection of the third coil. This terminal of the third coil is opposite the terminal of the third coil connected to the second coil.

Here and in the following, high-frequency voltage is understood as meaning an AC voltage with a frequency from 100 kHz to 1 GHz, preferably between 1 MHz and 20 MHz. Alternatively, instead of a high-frequency voltage, a high-frequency current can also be fed in at the high-frequency connection between the second and the third coil. In the following, the abbreviation "HF-" stands for "high-frequency-".

If a capacitor is connected and arranged between the HF connection and the electrical connection between the second coil and the third coil, an arrangement is created in which both the function of the ignition coil and the function of bandpass filtering are implemented and integrated:
The capacitor and the third coil, which form a series resonant circuit acting as a bandpass filter, are dimensioned in such a way that the frequency of an HF voltage generated in an HF generator connected to the HF connection lies in the passband of the bandpass filter. In this way, the HF voltage from the HF generator is additively coupled into the ignition coil.

In addition, the capacitor and the third coil of the bandpass filter are additionally dimensioned in such a way that ignition noise in the combustion chamber of the combustion engine in the higher-frequency spectral range of the bandpass filter, i.e. in the Stop band of the bandpass filter comes to rest. The ignition noise is blocked by an appropriately dimensioned bandpass filter and thus does not get from the combustion chamber to the HF generator. The functioning of the HF generator is therefore not disturbed by ignition noise.

Harmonic components of the high-voltage pulse, which are generated in the second coil and are below the cut-off frequency of a high-pass filter, are damped by suitably dimensioning the capacitor, which acts as a high-pass filter for the harmonic components of the high-voltage pulse. Thus, the harmonic components of the high-voltage pulse do not get from the second coil to the HF generator and do not disturb the functioning of the HF generator.

The DC component of the high-voltage pulse is blocked by the capacitor from the HF generator.

The magnet core is made of a soft magnetic material with a sufficient magnetic saturation flux density and a sufficient permeability. As a result, the magnetic flux that arises when a current flows through the electrical conductor of the coil, preferably the coil arranged on the primary side, is bundled and guided with low losses. The coil arranged on the primary side is referred to below as the first coil. In addition, the inductance of the first coil and the second coil is increased by the magnetic core. Due to the high permeability of the coils, the size of all coils that are wound around the magnetic core on the primary and secondary sides can be reduced compared to an air coil. The space requirement of an ignition coil can thus be reduced.

The materials used for magnetic cores are ferromagnetic metal alloys, usually in the form of sheet metal or foil or bonded powder, or ferrimagnetic oxide-ceramic materials (ferrites). In order to reduce eddy currents, which are generated in the magnet core by harmonic components of the high-voltage pulse and by the HF voltage, the magnet core is preferably composed of stacked metal sheets, between which dielectric layers, preferably made of paper or plastic, are arranged.

The first coil and the second coil are designed in relation to one another in such a way that a sufficient voltage transformation ratio is realized between the primary circuit and the secondary circuit of the ignition coil. In order to transform a secondary-side high-voltage pulse of typically several 10 kV from a primary-side voltage pulse of typically several 100 V, the number of turns on the secondary side is typically higher by a factor of 10 to 1000 than the number of turns on the primary side. In order to make the volume of the secondary-side coil approximately of the same order of magnitude as the volume of the primary-side coil, the diameter of the electrical conductor of the secondary-side coil is typically smaller by a factor of 10 to 1000 than the diameter of the electrical conductor associated with the primary-side coil.

Advantageous refinements and developments result from the further dependent claims and from the description with reference to the figures of the drawing.

It goes without saying that the features mentioned above and those to be explained below not only in the combination specified in each case, but also in others Combinations or alone can be used within the framework defined by the claims.

In order to position and orientate the first coil, the second coil, the third coil and the magnetic core within the ignition coil relative to each other, the first coil, the second coil, the third coil and the magnetic core are each preferably made of an electrically insulating material via a spacer element material connected to each other.

A spacer, a plastic film or a coil former around which the coil is wound can serve as a spacer element, for example. The individual spacer elements between the first coil, the second coil, the third coil and the magnetic core are each designed in such a way that the ignition coil has the most compact possible design and at the same time there is as little interference as possible between the first coil, the second coil, the third coil and present in the magnetic core.

Between the first coil, the second coil, the third coil and the magnetic core as well as the spacer elements arranged between them, there is typically a hardened casting compound made of a dielectric material, for example synthetic resin, preferably a casting resin. The potting compound serves not only to fix the individual coils and the magnetic core to one another, but also to provide electrical insulation, in particular to increase the high-voltage strength, between the individual coils.

In a first embodiment of an arrangement according to the invention, the third coil with its individual windings wound around the magnetic core on the secondary side. The secondary side of the ignition coil is thus formed by connecting the second and third coils in series. The high voltage pulse is thus generated both in the second coil and in the third coil. The serial connection of the second and the third coil can also be regarded as a single coil with two coil areas. In the transition between the two coil areas of such a single coil, an electrical contact connection, a so-called center connection, is therefore provided, which is electrically connected to the HF connection.

The advantage of the first version can be seen in the compact design of the ignition coil, since no additional space is required to place the third coil next to the ignition coil. In the first embodiment, the third coil thus fulfills a dual technical function. It is used for bandpass filtering and for generating the high-voltage pulse.

In a preferred form of the first embodiment, the third coil is optimized in terms of its HF transmission characteristic as part of the bandpass filter within the HF path by increasing the distances between successive turns of the third coil compared to successive turns of the second coil. Thus, the parasitic capacitances within the third coil are reduced compared to the usual parasitic capacitances of the second coil. Another technical measure to reduce the parasitic capacitances within the third coil and thus the It is possible to improve the HF transmission behavior of the third coil by using a winding of the third coil that is optimized for HF transmission.

Alternatively or in addition to reducing the parasitic capacitances, as a further technical measure to improve the HF transmission characteristics in the third coil, the wire diameter of the third coil is designed to be larger than the wire diameter of the second coil. An HF current, which is impressed by the HF voltage, only flows on the surface of the coil. For a given frequency-dependent penetration depth of the HF current, there is a larger cross-sectional area in the third coil than in the second coil. This reduces the ohmic resistance relevant to the HF current in the surface area of the conductor of the third coil compared to the conductor of the second coil. This effect improves the quality of the third coil designed as an HF coil and thus the HF transmission characteristics of the third coil. Thus, the HF current will flow more through the third coil and less through the second coil. Undesirable electrical coupling of the HF voltage or the HF current into the second coil is reduced in this way.

An inductive coupling of the HF voltage or the HF current from the secondary to the primary side of the ignition coil thus takes place, mainly from the third coil to the first coil. In the case of a greater distance between the individual turns of the third coil, a smaller number of turns in the third coil and thus a lower inductance for the third coil can be implemented, which causes less inductive coupling between the third and the first coil.

According to a preferred development of the invention, the third coil is coated, with its impedance being lower than the impedance of the base material. Since the HF current driven by the HF voltage flows on the surface of the third coil and thus primarily in the area of the coating of the third coil, the HF current will essentially flow through the third coil and not through the second coil, which does not Coating having a lower impedance. Silver, copper, gold, tin, aluminum, tungsten, molybdenum, titanium, zirconium, niobium, tantalum, bismuth, palladium and lead are suitable as coating materials. Alloys or composite materials made from one or more of these materials are also suitable.

In an ignition coil, the primary-side coil and the secondary-side coil(s) are wound together around a main leg of a magnetic core. In order to implement a closed iron path for the magnetic flux, the magnetic core has at least one yoke and two yokes, which each connect the main limb and the yoke. The magnetic core composed of the main leg, the return leg and the two yokes together encloses the primary and secondary coil(s). In a preferred embodiment of the ignition coil as a shell transformer, the magnetic core has a main leg, two yoke legs and two yokes, which connect the main limb and the two yoke legs to one another. A partial magnetic flux is thus guided in each case via the main leg, a return leg and two partial areas of the two yokes.

The primary side coil and the secondary side coil(s) are wound around the main leg concentrically with each other. The second and third coils preferably enclose the first coil. Alternatively, however, it is also possible for the first coil to enclose the second and third coils. Spacer elements are provided between the magnetic core, the first coil and the second and third coils for electrical insulation.

In a particular arrangement of the first embodiment of the invention, the third coil encloses the second coil and the first coil. The second coil preferably encloses the first coil. Alternatively, the first coil can also enclose the second coil.

In order to reduce the magnetic coupling between the third coil and the first coil as well as the second coil, a foil made of an easily magnetizable material, preferably made of a mu-metal, can be arranged between the third coil and the second coil. Alternatively, a copper foil can also be provided in which eddy currents are excited by the HF current flowing in the third coil and the electromagnetic field between the third coil and the second coil or the first coil is thus damped. For electrical insulation, a foil made of a dielectric material is arranged between the foil made of magnetizable material or the copper foil and the third coil and the second coil.

In a second embodiment of the ignition coil, which is not part of the present invention, the third coil is designed as an HF coil. According to the prior art, HF coils are wound around a magnetic core made of ferrite. Since ferrites typically do not have high heat resistance have, they are not very suitable for use in the vicinity of a motor with temperatures around 100 °C. For this reason, the third coil, which is to be designed as an HF coil, is preferably designed as a so-called air-core coil, ie as a coil without a magnetic core.

In the second embodiment of the ignition coil, the third coil is consequently positioned and oriented within the ignition coil in such a way that it does not enclose the magnetic core and the entire ignition coil thereby remains as compact as possible. In addition, when arranging the third coil in the second embodiment of the ignition coil, it must be taken into account that the lowest possible magnetic coupling between the third coil and the first and second coil is possible. In addition, as low as possible HF losses, in particular eddy current losses in the adjoining magnetic core, are to be aimed for through the HF feed into the third coil.

It is expedient here to position the individual windings of the third coil, which is realized as an air-core coil, at a lateral distance from an end face of the magnet core. The end face of the magnet core is understood to mean the side face of the magnet core whose area vector runs parallel to the longitudinal direction of the magnet core, ie to the longitudinal direction of the passage(s) of the magnet core. In addition, the cross-sectional area of the third coil is oriented parallel to the end face of the magnetic core. The cross-sectional area of the third coil is understood to mean the cross-sectional area of the third coil whose area vector runs parallel to the longitudinal direction of the third coil, ie to the longitudinal direction of the passage of the third coil.

Finally, the turns of the third coil enclose at least one area of the first coil and/or the second coil.

The third coil with its windings encloses at least one area of the first coil and/or the second coil, namely the area of the first coil and/or the second coil that protrudes from the magnet core, and at the same time is positioned at a lateral distance from the end face of the magnet core , the third coil with its turns takes up the free space on the side of the magnetic core that is not occupied by the first coil and/or the second coil. A space-saving integration of the third coil into the ignition coil is thus realized with the first sub-variant of the second embodiment of the ignition coil.

Since the cross-sectional area of the third coil is oriented parallel to the end face of the magnetic core, the magnetic fields of a third coil are largely orthogonal to the magnetic fields of the first and second coils, which are concentrated and guided as magnetic flux in the magnetic core. In this way, as a further advantage, the magnetic coupling between the third coil and the first or second coil is minimized.

The total inductance of the third coil can be doubled if a third coil is positioned on each side of the two end faces of the magnetic core and is connected to one another in series. The serial connection of a plurality of third coils thus offers a possibility of increasing the inductance of the bandpass filter and thus reducing the capacitance of the bandpass filter. With a lower capacity of the capacitor, a Realize high damping for the harmonic components of the high-voltage pulse through the capacitor, which also acts as a high-pass filter.

In a second sub-variant of the second embodiment of the ignition coil, the individual windings of the third coil, which is realized as an air-core coil, are each positioned at a lateral distance from an end face of the magnet core. The turns of the third coil are laterally spaced from one of the two yokes or from one of the two yokes. In addition, the cross-sectional area of the third coil is oriented perpendicularly to the end face of the magnetic core.

By positioning the third coil at a lateral distance from an end face of the magnet core, in particular at a lateral distance from one of the two yokes or from one of the two yokes, the third coil occupies the free space on the side of the magnet core that is occupied by the first coil and /or the second coil is not occupied. A compact design is thus realized.

Magnetic coupling between the third coil and the first and second coils is reduced because, with the exception of the transition area between the main leg and the two yokes, the magnetic field of the third coil is oriented orthogonally to the magnetic fields of the first and second coils. Since the transition area between the main leg and the two yokes is comparatively small and does not lie at the maximum of the magnetic field lines of the third coil, the magnetic coupling between the third coil and the first and second coils is low.

In this case, it is particularly expedient if a plurality of third coils connected to one another in series are positioned at a lateral distance from an end face of the magnet core. The cross-sectional areas of all third coils connected in series are each oriented perpendicularly to the end face of the magnet core.

Since a third coil can be positioned laterally spaced from each of the two yokes and from each of the two yokes of the magnetic core and from each of the two end faces of the magnetic core, up to eight third coils can be connected in series. Compared to a single third coil, the series connection of a plurality of third coils results in an increase in the total inductance. Since the third coil of the second sub-variant has a lower inductance than the third coil of the first sub-variant, primarily because of its smaller cross-sectional area and its lower number of turns, this disadvantage can be compensated for and possibly even even further by connecting several third coils in the second sub-variant in series be improved compared to the first sub-variant.

In a third sub-variant of the second embodiment of the ignition coil, the third coil is positioned at a lateral distance from the lateral surface of the first and/or the second coil. In addition, the cross-sectional area of the third coil is oriented perpendicularly to the end face of the magnetic core. The ignition coil is therefore less compact, but due to the greater distance between the third coil and the magnetic core it causes lower eddy current losses in the magnetic core, ie lower HF losses. Also the magnetic one Coupling between the third coil and the first and second coils is reduced because the distance between the third coil and the magnetic core is comparatively larger.

It has proven to be particularly advantageous if a further coil, which is designed as an HF coil, preferably as a choke coil, is connected between the HF connection and the second coil. This additional coil is referred to below as the fourth coil.

An HF coil, in particular a choke coil, dampens an HF voltage as best as possible and at the same time minimizes the eddy currents in the magnet core generated by the HF voltage.

To dampen the HF voltage, a choke coil has an inductive resistance, i.e. an impedance with a significantly higher inductive component than the capacitive component. The damping within the choke coil depends on the cross-sectional area, the number of turns and the coil length of the choke coil. In order to reduce HF losses, the choke coil is preferably designed as an air coil. The attenuation of the HF voltage reduces electrical coupling of the HF voltage impressed at the HF connection into the second coil. This advantageous effect occurs more clearly in the presence of parasitic capacitances between the secondary side of the ignition coil and the ignition coil housing, which is typically made of an electrically conductive material.

Like the third coil, the fourth coil can be positioned at a lateral distance from an end face of the magnet core. The cross-sectional area of the fourth coil, like the third coil, can be parallel or perpendicular to the end face of the Be oriented magnetic core. A series connection of several fourth coils to increase the inductance is also conceivable.

By wiring an ohmic resistance between the second coil and the HF connection, the coupling of the HF voltage into the ignition coil can be reduced. If suitably dimensioned, this ohmic resistance dampens the HF voltage in the direction of the ignition coil. The ohmic resistance also dampens the spark plug current driven by the HF pulse. This spark plug current, which causes the fuel-air mixture in the combustion chamber to ignite, is overlaid with a higher-frequency interference current caused by the ignition process. The higher-frequency interference current superimposed on the spark plug current is decoupled from the spark plug as EMC interference and emitted via the spark plug cable. Since the level of the higher-frequency interference current depends on the level of the spark plug current, the EMC emissions can be effectively reduced by damping the spark plug current using the ohmic resistor. Finally, there is a third embodiment of an ignition coil not forming part of the present invention, in which the third coil is laterally spaced from the first and second coils and the cross-sectional area of the third coil is preferably oriented perpendicular to an end face of the magnetic core. In addition, the third coil is arranged in a connection shaft within an engine block. In this way, the structural volume of the ignition coil outside the engine block is limited to the first coil, the second coil and the magnetic core, and the space required for the ignition coil is thus reduced considerably.

A connection shaft within an engine block is understood to mean a recess running from the outer surface of the engine block into the interior area of the engine block. This recess has a suitable cross-sectional profile, for example a round cross-sectional profile, and a specific length. The longitudinal extent of the connection shaft can be straight, curved or angled. The connection duct enables an electrical connection element to be routed between a spark plug mounted in the interior of the engine block and an ignition coil which is typically positioned outside the engine block or immediately adjacent to the outer surface of the engine block within the engine block.

Due to the preferably perpendicular orientation of the cross-sectional area of the third coil to an end face of the magnetic core, the magnetic field of the third coil runs orthogonally to the magnetic fields of the first and second coils belonging to the ignition coil. Thus, the magnetic coupling between the third coil and the first or second coil is reduced.

Since a third coil with a large number of windings can be positioned within the connecting shaft, a third coil with a high inductance can be implemented using the third embodiment of the ignition coil.

CONTENTS OF THE DRAWING

Fig. 1A

ein Schaltungsdiagramm einer ersten Ausführungsform der Anordnung, gemäß der Erfindung,

Fig. 1B

ein Schaltungsdiagramm einer zweiten Ausführungsform einer Anordnung, die nicht Teil der vorliegenden Erfindung ist,

Fig. 2A

eine dreidimensionale Darstellung der Zündspule der ersten Ausführungsform der Anordnung der Erfindung,

Fig. 2B

eine dreidimensionale Darstellung einer weiteren Ausprägung der Zündspule der ersten Ausführungsform der Anordnung,

Fig. 2C

eine dreidimensionale Darstellung einer in einem Gehäuse integrierten Anordnung aus Zündspule und Bandpassfilter,

Fig. 3A

eine dreidimensionale Darstellung einer Zündspule einer ersten Untervariante der zweiten Ausführungsform der Anordnung,

Fig. 3B

eine dreidimensionale Darstellung einer Zündspule einer zweiten Untervariante der zweiten Ausführungsform der Anordnung,

Fig. 3C

eine dreidimensionale Darstellung einer Zündspule einer Erweiterung der zweiten Untervariante der zweiten Ausführungsform der Anordnung,

Fig. 3D

eine dreidimensionale Darstellung einer dritten Untervariante der zweiten Ausführungsform,

Fig. 4A

eine dreidimensionale Darstellung einer Zündspule, die nicht Teil der vorliegenden Erfindung ist, mit einer ersten Ausprägung zur Minimierung des elektrischen Einkoppelns der HF-Spannung in die Primärseite der Zündspule,

Fig. 4B

eine dreidimensionale Darstellung Zündspule, die nicht Teil der vorliegenden Erfindung ist, mit einer zweiten Ausprägung zur Minimierung des elektrischen Einkoppelns der HF-Spannung in die Primärseite der Zündspule,

Fig. 4C

eine dreidimensionale Darstellung einer Zündspule, die nicht Teil der vorliegenden Erfindung ist, mit einer dritten Ausprägung zur Minimierung des elektrischen Einkoppelns der HF-Spannung in die Primärseite der Zündspule und

Fig. 5

eine Querschnittsdarstellung eines Motorblockes mit einer integrierten Zündspule, die nicht Teil der vorliegenden Erfindung ist.

The present invention is explained in more detail below with reference to the exemplary embodiments given in the schematic figures of the drawing. They show:

Figure 1A

a circuit diagram of a first embodiment of the arrangement according to the invention,

Figure 1B

a circuit diagram of a second embodiment of an arrangement which is not part of the present invention,

Figure 2A

a three-dimensional representation of the ignition coil of the first embodiment of the arrangement of the invention,

Figure 2B

a three-dimensional representation of a further form of the ignition coil of the first embodiment of the arrangement,

Figure 2C

a three-dimensional representation of an arrangement of ignition coil and bandpass filter integrated in a housing,

Figure 3A

a three-dimensional representation of an ignition coil of a first sub-variant of the second embodiment of the arrangement,

Figure 3B

a three-dimensional representation of an ignition coil of a second sub-variant of the second embodiment of the arrangement,

Figure 3C

a three-dimensional representation of an ignition coil of an extension of the second sub-variant of the second embodiment of the arrangement,

3D

a three-dimensional representation of a third sub-variant of the second embodiment,

Figure 4A

a three-dimensional representation of an ignition coil, which is not part of the present invention, with a first embodiment for minimizing the electrical coupling of the HF voltage into the primary side of the ignition coil,

Figure 4B

a three-dimensional representation of the ignition coil, which is not part of the present invention, with a second embodiment for minimizing the electrical coupling of the HF voltage into the primary side of the ignition coil,

Figure 4C

a three-dimensional representation of an ignition coil, which is not part of the present invention, with a third embodiment for minimizing the electrical coupling of the HF voltage into the primary side of the ignition coil and

figure 5

a cross-sectional view of an engine block an integrated ignition coil not forming part of the present invention.

The accompanying drawing figures are intended to provide a further understanding of embodiments of the invention. They illustrate embodiments and are used in context with the description explaining principles and concepts of the invention. Other embodiments and many of the foregoing advantages will become apparent by reference to the drawings. The elements of the drawings are not necessarily shown to scale with respect to one another.

In the figures of the drawing, elements, features and components that are the same, have the same function and have the same effect--unless stated otherwise--are each provided with the same reference symbols.

The figures are described in a coherent and comprehensive manner below.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Before the geometric arrangement of the individual components in an ignition coil of an arrangement according to the invention based on Figures 2A, 2B , 2C and in an ignition coil of an arrangement which is not part of the present invention, with reference to FIG Figures 3A , 3B , 3C , 3D , 4A , 4B , 4C and 5 are explained in detail, the electrical wiring of the individual components of an ignition coil or an arrangement for integrating an ignition coil and a bandpass filter of the invention is explained below using the circuit diagrams in Figure 1A (according to the invention) and 1B (not part of the present invention):
In the circuit diagram of Figure 1A an arrangement for the integration of a first embodiment of an arrangement with ignition coil and bandpass filter according to the invention is shown:
The first coil 1 is connected at one end via a DC voltage connection 2 of the ignition coil, a switch 3 to the electrode of a DC voltage source 4, preferably a battery. The other electrode of the DC voltage source 3 is connected to a ground potential. The further electrode of the first coil 1 is also connected to a ground potential via a ground connection 5 of the ignition coil. In the phase before ignition of the spark plug 6 connected to the ignition coil, the switch 3 is closed. A direct current which is driven by the direct voltage of the direct voltage source 5 flows through the first coil 1 of the ignition coil.

To ignite the spark plug 5, the switch 3 is opened and the flow of current through the first coil 1 is thus interrupted. This interruption of the current flow induces a voltage pulse in the first coil 1 . The voltage level of the voltage pulse depends on the inductance of the first coil 1 and the change in current in the first coil 1 and thus indirectly on the voltage level of the DC voltage source 4 . The voltage level of the voltage pulse is therefore on the order of several 100 V and is therefore not sufficient for the ignition of the fuel-air mixture inside the combustion chamber by the spark plug 6 . To amplify the voltage pulse induced in the first coil 1, a transformer or transmitter with a magnetic core 7 is provided in the ignition coil, around which the turns of the first coil 1 are wound on the primary side and the turns of a second coil 8 and one and a third coil 9 on the secondary side are.

If the number of turns in the two coils arranged on the secondary side is a multiple of the number of turns in the coil arranged on the primary side, the voltage pulse induced in the first coil 1 is transformed into a high-voltage pulse in the two coils arranged on the secondary side. To get out of the primary-side voltage pulse in To generate a secondary-side high-voltage pulse of several 10 kV at a height of several 100 V, a ratio between the turns of the first coil 1 and the turns of the second coil 8 and the third coil 9 of between 10 turns and several 100 turns is typically to be provided.

The design of the magnetic core 7 and the arrangement of the first coil 1, the second coil 8 and the third coil 9 will be explained in detail further below.

One end of the second coil 8 and one end of the third coil 9 are electrically connected to each other. The other end of the second coil 8 is connected to a ground potential via a further ground connection 10 of the ignition coil.

The other end of the third coil 9 is electrically connected to an electrode of the spark plug 6 via a high voltage terminal 11 of the ignition coil. The other electrode of the spark plug 6 is connected to ground potential.

To generate a high-voltage pulse with a superimposed HF voltage, an HF connection 12 belonging to the ignition coil is electrically connected to the second coil 8 and the third coil 9 for feeding in an HF voltage. This HF voltage is additively superimposed on the high-voltage pulse transformed into the second coil 8 and into the third coil 9 . Instead of an HF voltage, an HF current can also be impressed or fed in at the HF connection 12 . The HF voltage is generated in an HF voltage source 13 .

A capacitor 15 is connected between the HF source 13 and the HF connection 12 in order to form a bandpass filter 14 , which is implemented as a series resonant circuit made up of a coil and a capacitor. The third coil 9 serves as the coil of the series resonant circuit or the bandpass filter 15.

The capacitor 15 also serves as a high-pass filter. Its capacitance is dimensioned in such a way that the harmonic components of the high-voltage pulse generated in the second coil 8 come to lie in the low-frequency blocking range of the high-pass filter and are thus blocked in front of the HF voltage source 13 . Finally, the capacitor 15 is also blocking for the DC component of the high-voltage pulse generated in the second coil 8 . In the second parameterization step, the inductance of the third coil 9 is designed in such a way that, in combination with the capacitance of the capacitor 15 defined in the first parameterization step, there is a resonant frequency of the series resonant circuit and thus a center frequency of the bandpass filter 14 in which the frequency of the generated HF voltage lies comes. In this way, the bandpass filter 14 is transparent to the HF voltage generated, while it has a blocking effect on the higher-frequency ignition noise.

With the ignition coil according to Figure 1A an ignition coil is thus created that generates a high-voltage pulse with a superimposed HF voltage and at the same time integrates the coil of the bandpass filter with little effort. in the in Figure 1A In the illustrated first embodiment of an ignition coil of the invention, the coil of the bandpass filter is implemented as part of the secondary-side winding of an ignition coil. The secondary winding of the ignition coil is thus composed of the serial connection of the second coil 8 and the third coil 9 together. The invention also covers the alternative case in which the secondary-side winding of the ignition coil is realized as a single coil arranged on the secondary side, comprising two coil regions connected to one another in series. A so-called center contact or center connection for feeding in the HF voltage is provided in the connection area between the two coil areas. The integration of the coil of the band-pass filter in the secondary-side winding of the ignition coil also advantageously reduces the structural volume of the arrangement of the ignition coil and band-pass filter.

In a second embodiment not forming part of the present invention, the third coil 9 is located outside the magnetic core 7 of the ignition coil. Only the windings of the first coil 1 and the second coil 8 are wound around the magnetic core 7 . The magnetic flux is guided and concentrated in the magnetic core 7 between the first coil 1 arranged on the primary side and the second coil 8 arranged on the secondary side. A large part of the inductive coupling is thus only realized between the first coil 1 and the second coil 8 . Rather, in the second embodiment of the ignition coil, the third coil 9 is arranged in the immediate vicinity of the magnetic core 7 and the first and second coils 1 and 8 . The inductive coupling between the first coil 1 and the third coil 9 is thus significantly reduced compared to the first embodiment. The inductive coupling between the first coil 1 and the third coil 9 takes place here only via the leakage flux.

The second embodiment of the ignition coil does not differ from the first embodiment in the remaining details.

A repeated description of the features and components that are identical to the first embodiment is therefore omitted at this point.

Out of Figure 2A shows an arrangement of an ignition coil of a first embodiment of the arrangement:
The magnetic core 7 is made up of layered metal sheets between which layers of electrically insulating material are arranged. The laminated sheets are made of a soft magnetic material, preferably iron. The layering of the sheets prevents eddy currents in the longitudinal direction of the magnet core 7 .

The magnet core 7 is composed of a main leg 16 , two return legs 17 ₁ and 17 ₂ and two yokes 18 ₁ and 18 ₂ which connect the two return legs 17 ₁ and 17 ₂ to the main leg 16 . Around the main leg 16, the turns of the first coil 1, the second coil 8 and the third coil 9 are wound. The windings of the first coil 1, the second coil 8 and the third coil 9 are each passed through two bushings in the magnetic core 7, each between the main leg 16, one of the two return legs 17 ₁ and 17 ₂ and one area of the two yokes 18 ₁ and 18 ₂ are arranged in the longitudinal direction of the magnetic core 7 .

In addition to this preferred design of the ignition coil, which is also referred to as a sheathed transformer, a design of the ignition coil is also conceivable in which the magnetic core 7 has only a single yoke leg. A higher compactness of the ignition coil is realized in this design, however, at the expense of a higher leakage flux. The Realization of the ignition coil as a core transformer with two main legs and two yokes connecting the two main legs to one another is also conceivable. The turns of the first coil 1 are wound around one main leg and the turns of the second and third coils 8 and 9 are wound around the other main leg. A more compact winding of the windings arranged on the primary side and the windings arranged on the secondary side around the associated main leg and thus a smaller longitudinal extension of the ignition coil requires a larger transverse extension of the ignition coil due to the provision of two main legs.

The turns of the first coil 1 preferably enclose, as in Figure 2A is indicated, next to the main leg 16 is the main leg 16, while the turns of the second and third coils 8 and 9 enclose the turns of the first coil 1. The turns of the second and third coils 8 and 9 are in Figure 2A illustrated first expression arranged adjacent to each other in their direction of longitudinal extension. The transverse extent of the second and the third coil 8 and 9 and thus also the transverse extent of the ignition coil is minimized in this embodiment.

The first coil 1, the second coil 8 and the third coil 9 are each wound around a winding body made of an electrically insulating material, which is Figure 2A is not shown for reasons of clarity. Each of these winding bodies serves as a spacer element between the magnetic core 7, the first coil 1, the second coil 8 and the third coil 9. The individual winding bodies are preferably connected to one another. In this way, the magnetic core 7, the first coil 1, the second coil 8 and the third coil 9 can be positioned relative to one another and oriented toward one another. In particular, an arrangement with a minimized distance and thus a minimized installation space is possible with such winding bodies or spacer elements.

Out of Figure 2A the electrical connection between the second coil 8 and the third coil 9, which is connected to the HF connection 12, can be seen. The two ground connections 5 and 10 of the first coil 1 and the second coil 8, the DC voltage connection 2 connected to the first coil 1 and the high-voltage connection 11 connected to the output of the third coil 9 are in Figure 2A to recognize.

The ignition coil is preferably according to Figure 2C arranged in a housing 19. This housing 19, which is in Figure 2C is indicated by dashed lines is preferably made of an electrically conductive material, for example aluminum, in order to achieve a good electromagnetic shielding effect. In this way, the HF voltage coupled into the ignition coil does not penetrate into the exterior of the housing 19 and thus does not have a negative effect on or destroy electronics arranged in the engine compartment of a vehicle. On the other hand, due to the shielding housing, HF electronics located in the engine compartment of a vehicle have no negative effects on the high-voltage pulse generated in the ignition coil and on the Figure 2C not shown control electronics of the ignition coil.

The capacitor 15 and thus the bandpass filter 14 are completely integrated into the housing 19 of the ignition coil. This leads to a compact design of an arrangement for integrating the ignition coil and bandpass filter. For special space-saving positioning within the housing 19 is the capacitor 15, as in Figure 2C is indicated, in a space not yet occupied within the housing 19 laterally spaced from an end face of the magnetic core 7 arranged. Alternatively, however, the capacitor 15 can also be arranged outside of the housing 19 .

All ignition coil connections are as in Figure 2C is indicated, led out of the housing 19. Suitable plug connectors, preferably housing plug connectors, can preferably be designed for the individual connections of the ignition coil. In this connection it should be mentioned that the HF terminal 12 of the ignition coil, which is electrically connected to the second coil 8 and the third coil 9, is offset to the other terminal of the capacitor 15 due to the integration of the capacitor 15 in the housing 19 and thus is led out of the housing 19 as an HF connection 12'.

When the ignition coil is installed in the housing 19, a liquid casting compound 20 made of an electrically insulating material, preferably a casting resin 20, particularly preferably polyurethane, is introduced between the housing 19 and the ignition coil and the spaces between them. After the casting compound 20 has hardened, the intermediate space between the housing 19 and the ignition coil is completely filled with the hardened casting compound 20 . In this way, the high-voltage strength of the ignition coil between its individual components - magnetic core 7, first coil 1, second coil 8 and third coil 9 - and also between the individual components of the ignition coil and the electrically conductive housing 19 is additionally increased. In addition, the spacing between the third coil 9 designed as an HF coil and the electrically conductive housing 19 and between the third coil 9 and the typically grounded magnet core 7 should be interpreted by the potting compound 20 in such a way that the parasitic capacitances of the third coil 9 are at a low level. The high-voltage strength of the third coil 9 embodied as an HF coil can be additionally improved in addition to the insulation by the casting compound 20 by an insulated HF coil, for example by an HF coil made with an enamelled copper wire. The first coil 1 and the second coil 8 can also be wound with an enamelled copper wire to increase the high-voltage strength.

In a second form of the ignition coil according to the first embodiment Figure 2B the third coil 9 is not arranged adjacent to the second coil 8 in the direction of longitudinal extent, but encloses the second coil 8. The third coil 9 is therefore arranged adjacent to the second coil 8 in the direction of transverse extent. In this case, the third coil 9 can be wound on a winding body. In order to reduce the magnetic coupling between the third coil 9 and the first coil 1 and the second coil 8, a foil 26 made of an easily magnetizable material, preferably a mu-metal, is arranged between the third coil 9 and the second coil 8 . Alternatively, a copper foil can also be arranged in which eddy currents are excited by the HF current flowing in the third coil 9 and the electromagnetic field between the third coil 9 and the second coil 8 or the first coil 1 is thus damped. For electrical insulation, a foil made of a dielectric material, preferably made of a plastic, in particular polyurethane, is arranged between the foil 26 made of magnetizable material or the copper foil and the third coil 9 and the second coil 8 .

Also in the first form of the ignition coil according to the first embodiment Figure 2A With regard to a more compact design, a dielectric plastic film can be arranged between the first coil 1 and the second coil 8 or the third coil 9 instead of winding bodies.

In both forms of the first embodiment according to the Figures 2A and 2B the third coil 9 can be designed like the second coil 8 with regard to its transmission characteristic, in particular its HF transmission characteristic. However, since an HF current driven by the applied HF voltage should flow through the third coil 9 as optimally as possible, while electrical coupling of the HF current into the second coil 8 should be minimized as far as possible, a high-frequency optimization of the third coil 9 to strive for, as shown below:
In a first technical measure, the distances between successive turns of the third coil 9 are designed to be greater than the distances between successive turns of the second coil 8 . The parasitic capacitances, which occur in particular between two consecutive turns, are thus minimized in the third coil 9 compared to the second coil 8 and the HF transmission characteristic of the third coil 9 compared to the second coil 8 is thus optimized.

In a second technical measure, the parasitic capacitances in the third coil 9 are minimized by a special winding of the electrical conductor. The third coil 9 is, for example, a honeycomb, basket bottom, star or flat coil wound. The HF transmission behavior of the third coil 9 compared to the second coil 8 can be optimized in this way. An additional improvement in the HF transmission behavior for the third coil 9 is achieved by winding an HF stranded wire as an electrical conductor for the third coil 9 .

In a third technical measure, the wire diameter, i.e. the diameter of the electrical conductor, of the third coil 9 is designed to be larger than the wire diameter of the second coil 8. Due to the skin effect, the HF current only flows on the surface of the electrical conductor of a coil and, starting from the surface of the electrical conductor, penetrates only up to a certain penetration depth, which depends, among other things, on the frequency of the HF current and the material parameters of the electrical conductor depends, in the electrical conductor of the coil. In the case of an electrical conductor with a larger diameter and the same penetration depth, the cross-sectional area of the electrical conductor of the coil in which the HF current flows is larger than in the case of an electrical conductor with a smaller diameter due to the larger circumference. The electrical impedance of the third coil 9, which acts on the HF current, is therefore smaller than in the second coil 8 due to the second technical measure. The HF transmission characteristic is thus improved in the third coil 9 compared to the second coil 8.

In a fourth technical measure, the third coil 9 is coated, while the second coil 8 remains uncoated. The coating of the third coil 9 has a lower electrical impedance than the base material of the third coil 9 . Thus, the coating becomes a coating material manufactured, which has a higher electrical conductivity and / or lower permeability than the base material. The HF current, which flows due to the skin effect in the surface area of the electrical conductor of the coil, consequently encounters better HF transmission characteristics in the third coil 9 than in the second coil 8.

At this point it should be mentioned that the inductance of the base material of the second coil 2 is many times greater than the total inductance of the base and coating material of the third coil 9, so that the HF current preferentially flows through the second coil 8 because of the significantly higher impedance the third coil 9 flows.

In the ignition coil of the second embodiment of the arrangement which is not part of the present invention, which is described below with reference to FIG Figures 3A , 3B , 3C and 3D is presented, the third coil 9 has no magnetic core and is thus realized as an air-core coil. With a suitably selected orientation of the third coil 9 to the magnetic core 7, it is possible to significantly minimize the magnetic and inductive coupling between the third coil 9 and the first coil 1 via the magnetic flux conducted and concentrated in the magnetic core 7. A magnetic and inductive coupling with the first coil 1 only exists via the much weaker leakage flux. In contrast to the first embodiment of an ignition coil, the magnetic and inductive coupling of the HF voltage from the secondary side into the primary side of the ignition coil is significantly minimized.

In the ignition coil according to the first sub-variant of the second embodiment Figure 3A the third coil 9 realized as an air-core coil is laterally spaced from an end face 21 of the magnetic core 7 positioned. In addition, the turns of the third coil 9 enclose at least one area of the first coil 1 and the third coil 8 which corresponds to the area of the first coil 1 and the third coil 8 protruding from the magnet core 7 .

The third coil 9 thus occupies the still unused space on the side of the magnetic core 7 which is not used by the first coil 1 and the second coil 8 . However, the third coil 9 is positioned close to the magnetic core 7 and the first and second coils 1 and 8 in order to make the ignition coil compact. In this way, a compact design for the ignition coil is realized. Of course, the third coil 9 in the Figure 3A illustrated arrangement of an ignition coil may be arranged not only above the magnetic core 7, but also below the magnetic core 7.

Finally, the cross-sectional area of the third coil 9 is oriented parallel to the end face 21 of the magnet core 7 . Due to this orientation of the third coil 9 to the magnetic core 7, the magnetic field of the third coil 9 runs orthogonally to the direction of the magnetic flux of the first and second coils 1 and 8 within the magnetic core 7. Only in the transition area between the main leg and the two yokes of the magnetic core 7 the orthogonality in the orientation of the magnetic field of the third coil 9 to the magnetic flux within the magnetic core 7 is slightly absent. However, since this transition area is very small and does not lie at the maximum of the magnetic field strength of the third coil, magnetic and inductive coupling between the third coil 9 and the two other coils of the ignition coil, in particular the first coil 1, is minimized as far as possible.

In the ignition coil of a second sub-variant of the second embodiment, the third coil 9 is also positioned at a lateral distance from an end face 21 of the magnet core 7 . The third coil 9 is arranged laterally adjacent either to one of the two yokes or to one of the two yokes of the magnet core 7 . Thus, in the second sub-variant as well, the third coil 9 occupies the still unused space on the side of the magnet core 7 that is not used by the first coil 1 and the second coil 8 . A compact design for the ignition coil is also achieved in this case.

In the second sub-variant, the cross-sectional area of the third coil 9 is positioned perpendicular to an end face 21 of the magnet core 7 . In the second sub-variant as well, the magnetic field of the third coil 9 within the magnetic core 7 is oriented orthogonally to the direction of the magnetic flux of the first and second coils 1 and 8 guided in the magnetic core 7 . Only in the transition area between the main leg and the two yokes of the magnetic core 7 is there slightly no orthogonality between the magnetic field of the third coil 9 and the magnetic flux of the first and second coils 1 and 8 guided in the magnetic core. Since the coil length is typically greater than the wire diameter of the third coil 9, the orthogonality between the magnetic field of the third coil 9 and the magnetic flux of the first and second coils 1 and 8 guided in the magnetic core is in the transition area between the main leg and the two yokes of the magnetic core 7 slightly less pronounced in the second sub-variant than in the first sub-variant. But since the transition area is comparatively very small here and is not at the maximum of the magnetic field strength of the third coil 9, is also in the second sub-variant of the second embodiment, the magnetic coupling between the third coil 9 and the first and the second coil 1 and 8 is reduced.

In the second sub-variant, the third coil 9 has a smaller cross-sectional area than in the first sub-variant and thus has a lower inductance. As already mentioned above, the design of the bandpass filter 14 requires a comparatively high inductance for the third coil 9 for a given frequency of the HF voltage and for a comparatively low capacitance of the capacitor 15 .

For this purpose, according to an extension of the second sub-variant of the second embodiment Figure 3C several third coils 9 ₁ , 9 ₂ , 9 ₃ and 9 ₄ connected in series. With each additional third coil connected in series, the total inductance of such a series connection of third coils increases by the inductance of a single third coil.

Since a third coil 9 can be positioned laterally spaced on each yoke and on each yoke leg of the magnetic core 7 and on each of the two end faces 21 of the magnetic core 7, up to eight third coils can be positioned and connected in the ignition coil. In this way, the total inductance of such a series connection of third coils can be multiplied by a factor of eight compared to the inductance of a single third coil.

In the first sub-variant as well, the inductance of the third coil 9 can be doubled if it is spaced apart laterally a third coil is positioned on each of the two end faces 21 of the magnetic core 7 and the two third coils are connected in series with one another.

In the ignition coil according to a third sub-variant of the second embodiment 3D the third coil 9 is positioned laterally to the lateral surface of the first coil 1 and the second coil 8, preferably laterally to the lateral surface of the second coil 8 arranged on the outside. Due to the lateral positioning of the third coil 9 in relation to the first and second coils 1 and 8, the design of the ignition coil in the third sub-variant of the second embodiment is slightly worse than all sub-variants and embodiments previously presented. At the expense of the less compactness of the ignition coil, lower eddy current losses in the magnet core 7, ie lower HF losses of the third coil 9 through which an HF current flows, can be realized in the third sub-variant due to the greater distance between the third coil 9 and the magnet core 7. The magnetic and inductive coupling between the third coil 9 and the two coils of the ignition coil, in particular the first coil 1, is reduced due to the greater distance between the third coil 9 and the magnetic core 7. Finally, in the third sub-variant, a higher inductance for the third coil 9 can be realized since there is free space for lengthening the third coil 9 and for increasing the cross-sectional area of the third coil 9 .

In addition to minimizing the magnetic coupling between the third coil 9 and the other two coils of the ignition coil, in particular the first coil 1, the electrical coupling of the HF voltage from the HF connection 12 into the second coil 8 must also be minimized. Minimizing the electric The coupling of the HF voltage from the HF connection 12 into the second coil 8 is described below with reference to FIG Figures 4A to 4C explained in detail:
In a first variant for minimizing the electrical coupling of the HF voltage from the HF connection 12 into the second coil 8 according to FIG Figure 4A an ohmic resistor 22 is connected between the HF connection 12 and the second coil 8 . In order to achieve the most compact design possible for the ignition coil, the ohmic resistor 22 should preferably be positioned in a space not yet used by the first coil 1, the second coil 8 and the third coil 9, to the side of one of the two end faces 21 of the magnet core 7 .

The ohmic resistor 22 is dimensioned in such a way that an HF current driven by the HF voltage at the HF connection 12 is damped in such a way that only a comparatively small HF current flows through the second coil 8 . The ohmic resistance 22 is also to be dimensioned in relation to the ohmic resistance within the second coil 8 such that the HF voltage level at the transition between the second coil 8 and the ohmic resistance 22 is significantly lower than at the HF connection 12 .

As an additional positive effect, the ohmic resistor 22 also dampens the spark plug current driven by the high-voltage pulse. This spark plug current, which causes the fuel-air mixture in the combustion chamber to ignite, is overlaid with a higher-frequency interference current caused by the ignition process. The higher-frequency interference current superimposed on the spark plug current is disadvantageously decoupled from the spark plug as EMC interference and radiated in the spark plug supply line. Because the level of the higher frequency Interference current is dependent on the level of the spark plug current, the EMC emissions can be effectively reduced by damping the spark plug current by means of the ohmic resistor 22 .

In a second variant for minimizing the electrical coupling of the HF voltage from the HF connection 12 into the second coil 8 according to FIG Figure 4B Another coil 23, which is referred to below as the fourth coil 23, is connected between the HF connection 12 and the second coil 8. This fourth coil 23 is in the form of an HF coil and is therefore implemented as an air-core coil with a view to minimizing the HF losses. The fourth coil 23 is preferably designed as a choke coil and dampens the HF voltage fed in at the HF connection 12 with its inductive impedance. Consequently, at the transition between the fourth coil 23 and the second coil 8 there is an HF voltage level which is reduced compared to the voltage level of the HF voltage at the HF connection 12 .

With regard to a compact design of the ignition coil, the fourth coil 23, realized as an air-core coil, is positioned at a lateral distance from an end face 21 of the magnetic core 7 in analogy to the third coil 9 in the first subvariant of the second embodiment of an ignition coil and encloses the area protruding from the magnetic core 7 the first coil 1 and the second coil 8. According to Figure 4B the third coil 9 and the fourth coil 23 are each positioned laterally spaced from two different end faces 21 of the magnet core 7, so that an ignition coil with the highest compactness is realized.

The cross-sectional area of the fourth coil 23 is parallel to one in analogy to the cross-sectional area of the third coil 9 Face 21 of the magnetic core 7 oriented. In this way, the magnetic fields of both the third coil 9 and the fourth coil 23 are each oriented orthogonally to the direction of the magnetic flux of the first coil 1 and the second coil 8 within the magnetic core 7 . Thus, the magnetic and inductive coupling of the third coil 9 and also the fourth coil 23 to the first coil 1 and the second coil 8 is reduced.

According to Figure 4C In analogy to the third coil in the second sub-variant of the second embodiment, the fourth coil 23 can be positioned laterally spaced from an end face 21 of the magnet core 7 and at the same time be oriented with its cross-sectional area perpendicular to an end face 21 of the magnet core 7. The third coil 9 and the fourth coil 23 can according to Figure 4C be positioned laterally spaced from two different end faces 21 of the magnet core 7 .

In analogy to the expansion of the second sub-variant of the second specific embodiment, with regard to an increase in the inductance of the fourth coil 23, a plurality of fourth coils 23 can be connected in series and arranged in a space-optimized manner within the ignition coil.

In a third embodiment of an arrangement which is not part of the present invention and which is shown in figure 5 is shown, the third coil 9 is arranged in the connection shaft 24 of an engine block 25 with regard to a compact design. The third coil 9 is positioned laterally to the lateral surface of the first coil 1 and the second coil 8, preferably laterally to the lateral surface of the second coil 8 arranged on the outside.

The cross-sectional area of the third coil 9 is oriented parallel to an end face 21 of the magnet core 7 . In this way, the magnetic field of the third coil 9 is oriented orthogonally to the magnetic flux of the first coil 1 and the second coil 8 that is guided in the magnetic core 7 . Thus, the magnetic and inductive coupling between the third coil 9 and the first coil 1 is minimized with the exception of the coupling due to the leakage flux.

The housing 19 of the ignition coil, which is in figure 5 is indicated by dashed lines is designed in such a way that it contains all the components of the ignition coil and can be inserted into the connection shaft 24 of the engine block 25 .

Although the present invention has been fully described above with reference to preferred exemplary embodiments, it is not limited thereto but can be modified in a variety of ways within the scope of protection defined by the claims.

Reference List

1

first coil

2

DC connection

3

Switch

4

DC voltage source

5

ground connection

6

spark plug

7

magnetic core

8th

second coil

9

third coil

91, 92, 93, 94

third coil

10

ground connection

11

high voltage connection

12, 12'

high frequency connector

13

high-frequency voltage source

14

bandpass filter

15

capacitor

16

main thigh

171, 172

conclusion leg

181, 182

yoke

19

Housing

20

potting compound

21

face

22

ohmic resistance

23

fourth coil

24

connection shaft

25

engine block

26

foil

Claims (5)

1. An arrangement for the integration of an ignition coil and a bandpass filter (14) comprising a capacitor(15) and an ignition coil for generating a high voltage pulse with a superimposed high voltage frequency, wherein the ignition coil has

   a first coil (1) arranged on the primary side,

   a second coil (8) arranged on the secondary side,

   a third coil (9) arranged on the secondary side

   and a magnetic coil (7),

   wherein windings of the first coil (1), the second coil (8) and the third coil (9) are wound around the magnetic core (7),

   wherein a connection of the second coil (8), a connection of the third coil (9) and a connection (12) of the capacitor (15) are electrically conductively connected to each other, wherein the connection (12) is a high frequency connection (12) of the ignition coil,

   wherein a further connection of the capacitor (15) is set up on the capacitor side opposite said connection (12) of the capacitor, in order to receive a high frequency voltage,

   wherein a further high voltage connection (11) of the third coil (9), is set up on an end of the third coil (9) opposite said connection of the third coil (9), to be electrically conductively connectable to an ignition plug (6),

   wherein the bandpass filter (14) has the capacitor (15) and the third coil (9) of the ignition coil.
2. The arrangement according to patent claim 1,
   wherein between the first coil (1), the second coil (8), the third coil (9) and the magnetic core (7) in each case a spacer element made of electrically insulating material is arranged, by means of which the first coil (1), the second coil (8), the third coil (9) and the magnetic core (7) are each positioned and oriented in respect to each other.
3. The arrangement according to patent claim 1 or 2,
   wherein successive windings of the third coil (9) each have a greater spacing and/or a greater wire diameter than each of the successive windings of the second coil (8).
4. The arrangement according to claims 1 to 3,
   wherein the third coil (9) encloses the first coil (1) and the second coil (8) and is positioned separated from the second coil (8) by a film (26) made of a magnetizable material.
5. An arrangement for feeding a high frequency voltage into an ignition coil comprising the arrangement according to any one of claim 1 to 4 and a high frequency voltage source (13), wherein a connection of the high frequency voltage source (13) is connected to the further connection of the capacitor (15).

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