DE102019200436A1 - Coil arrangement with a plurality of coil pairs arranged thereon in one plane and device with such a coil arrangement - Google Patents

Abstract

The invention relates to a coil arrangement with a plurality of coil pairs (1; 10; 20a, 20b) arranged in one plane, the individual coils of which are each formed and connected to one another in such a way that the currents (3, 4; 12, 13) are oppositely directed and of equal size, the coil pairs (1; 10; 20a, 20b) being point-symmetrical and oriented in relation to one another in such a way that a magnetically active object (22) which is located at the point of symmetry (14) of a coil pair ( 1; 10; 20a, 20b), the equality of the currents (3, 4; 12, 13) at least one adjacent pair of coils (1; 10; 20a, 20b) is canceled.

Description

The invention relates to a coil arrangement with a plurality of coil pairs arranged in one plane, the individual coils of which are each formed and connected to one another in such a way that the currents induced therein by a magnetic field are directed in opposite directions and are of equal size. The invention also relates to a device for the inductive transmission of energy with a primary and a secondary coil, between which such a coil arrangement is arranged.

Such a coil arrangement and such a device are from the US 2013/0169062 A1 known. There, on the one hand, a pair of coils consisting of two semicircular single coils made of a wire are described, in which the individual coils are rotated relative to one another, so that the currents caused by a magnetic field penetrating them are opposite and of equal magnitude, that is, they cancel each other out. A homogeneous, interference-free magnetic field, which is generated by a primary coil of a device for inductive energy transmission and which penetrates the individual coils, does not generate any voltage at their wire ends.

The US 2013/0169062 A1 on the other hand discloses a circular coil arrangement with pairs of coils, which is designed with individual coils formed from circular segments, which are also produced with only one wire.

The problem with these arrangements of the coil pairs is that there are points of symmetry and lines of symmetry, so that magnetically active objects which interfere with the magnetic field and are in principle to be detected by the coil arrangement are not recognized if they lie on or above these points of symmetry and lines of symmetry, because the disturbance of the magnetic field in the individual coils of the coil pairs also has a symmetrical effect and does not lead to any induced voltage or to any current caused thereby.

It is therefore the object of the invention to provide a coil arrangement and a device with such a coil arrangement, in which it is possible to recognize all magnetically active objects despite partial symmetries.

The object is achieved by a coil arrangement according to claim 1 and a device with such a coil arrangement according to claim 7. Advantageous further developments are specified in the subclaims.

Accordingly, in a coil arrangement with a plurality of coil pairs arranged in one plane, the individual coils of which are each formed and connected to one another in such a way that the currents induced therein by a magnetic field are oppositely directed and of the same size, the coil pairs are formed point-symmetrically and are arranged in such a way that they are oriented to one another are that a magnetically active object, which is located at the point of symmetry of a pair of coils, cancels the equality of the currents of at least one adjacent pair of coils.

Even if a pair of coils does not experience any change in the current flowing through its conductor, since the change in the magnetic field caused by the magnetically effective object has the same amount in both individual coils of the pair of coils, but in the opposite direction, the presence of this object is nevertheless detected in a coil arrangement according to the invention , because an adjacent pair of coils is oriented in such a way that different magnetic field changes and thus different currents occur in the individual coils of the object and thus different currents, which no longer cancel each other out. Whenever an object in such a coil arrangement comes to lie on a point of symmetry of a pair of coils, there will always be at least one further adjacent pair of coils by which the object is detected.

In the case of a spatially homogeneous magnetic field penetrating the coils of the coil arrangement, it is advantageous if, in an embodiment of the coil arrangement according to the invention, the individual coils all have the same shape and size. This ensures that in the event that there is no object in the area of the coil arrangement, no induced voltage arises at the connections of the coil pairs.

In an advantageous embodiment of the coil arrangement, the lines of the individual coils of a pair of coils are guided in the form of an eight.

This means only the basic relation of the two individual coils of a pair of coils to each other and not their shape. Although this can be approximately circular, it preferably has the shape of a square or a rhombus or any other shape in which pairs of coils can be arranged side by side without creating too many gaps in which a magnetic field is not detected.

In a particularly advantageous development of a coil arrangement according to the invention, the axes of the two adjacent pairs of coils, the loop connecting points of which are separated from one another by an eight-loop, go through the loops and the loop connection point of an eight, perpendicular to one another.

This means that the closest adjacent pairs of coils, almost touching each other without overlapping, are always aligned in such a way that their axes are at right angles to each other. The affected axis is the one that runs through the two eight loops and the loop connection point, i.e. usually the point of symmetry. This axis is usually also an axis of symmetry of a pair of coils.

This orientation towards one another ensures that an object which lies on the point of symmetry or the axis of symmetry of one pair of coils and therefore is not detected by this pair of coils is in any case recognized by the pair of coils closest to it.

In an advantageous embodiment, the coil arrangement is formed on a coil carrier. This can be a film or a circuit board, for example.

In a further development, the pair of coils can be printed on the coil carrier.

In a device according to the invention for the inductive transmission of energy with a primary and a secondary coil, a coil arrangement according to the invention is arranged between the primary and the secondary coil.

A coil arrangement according to the invention can thus advantageously be used in such a device for the inductive transmission of energy for the detection of magnetically active objects, for example metals such as e.g. Coins are used because they should switch off the energy transfer due to heating due to eddy currents and thus increased fire risk.

The coil arrangement can be arranged in a simple manner on the primary coil.

• 1 eine erste Ausführung eines Spulenpaars nach dem Stand der Technik,
• 2 eine zweite vorteilhafte Ausführung eines Spulenpaars,
• 3 eine erste erfindungsgemäße Spulenanordnung mit Spulenpaaren gemäß 2
• 4 eine zweite erfindungsgemäße Spulenanordnung mit Spulenpaaren gemäß 2 und
• 5 eine Vorrichtung zur induktiven Übertragung von Energie mit einer Primär- und einer Sekundärspule, zwischen denen eine erfindungsgemäße Spulenanordnung angeordnet ist.

The invention is described in more detail below on the basis of exemplary embodiments with the aid of figures. Show

• 1 a first embodiment of a pair of coils according to the prior art,
• 2nd a second advantageous embodiment of a pair of coils,
• 3rd a first coil arrangement according to the invention with pairs of coils 2nd
• 4th a second coil arrangement according to the invention with pairs of coils according to 2nd and
• 5 a device for inductive transmission of energy with a primary and a secondary coil, between which a coil arrangement according to the invention is arranged.

The 1 shows a pair of coils 1 that from a ladder 2nd is made. The leader 2nd can be a wire or a printed conductor printed on a foil or a printed circuit board or applied in some other way.

A first single coil is made by the conductor 2nd is first performed in a first section a. Thereafter, it is guided counterclockwise in a second section b in a semicircle, in order to then be guided almost parallel again to section a, but crossing it in a third section c. Finally, it is guided clockwise in a fourth section d in a semicircle. The result is an approximately elliptical or circular double coil which has two loops a, b and c, d, which are wound like an eight and lie next to one another in one plane.

If a homogeneous magnetic field in the coil plane of the 1 A voltage is induced in the individual coils, which leads to a current flow according to the arrows 3rd , 4th leads, so in the same conductor 2nd flow in opposite directions and cancel each other out due to the symmetry of the individual coils.

This has the advantage that there is no voltage at the wire ends in a homogeneous magnetic field without interference and therefore no heat-generating currents can flow.

Another embodiment of a pair of coils with the described properties is shown in 2nd shown. The pair of coils there 10th is with a leader 11 formed, which is here straight in a first lead section a, then to bend to the right at an angle of about 45 ° downward and then to be guided counterclockwise in a square b back to the first break point and form a first single coil. The conductor is at the kink 11 then just continued in order to then lead clockwise in a further square c back to the break point and to be guided therefrom parallel to the first supply section a in a second supply section d.

Here too, a planar pair of coils 10th formed, in the case of a homogeneous magnetic field that penetrates the individual coils, currents according to the arrows 12th and 13 train who cancel each other out. In the embodiment of the 2nd can have many pairs of coils 10th side by side be formed without leaving larger areas that are not covered by a coil.

The pair of coils 10th of the 2nd has a point of symmetry 14 that with the break point of the conductor 11 matches and there is an axis 15 by the eight loops and the point of symmetry 14 runs and forms an axis of symmetry.

If a magnetically effective object on the point of symmetry 14 or along the axis 15 comes to rest, the magnetic field in both individual coils is influenced in the same way, for example amplified, but as a result, however, the currents in both individual coils of the pair of coils 10th change in the same way and therefore no voltage or current change can be detected at the coil connections.

In the 1 and 2nd are symmetrical coil pairs 1 , 10th represents, since a homogeneous magnetic field is assumed. However, the coil pairs can be adapted to a non-uniform magnetic field by changing the size of one of the individual coils, by making them correspondingly larger in the case of a weaker magnetic field in the individual coil in order to achieve the same overall flux.

Instead of a square shape, as in the 2nd For a single coil, a rhombus can also be selected, as a result of which good surface coverage can also be achieved with a coil arrangement with a plurality of coil pairs.

In the 3rd is now a coil arrangement according to the invention using the example of coil pairs 20a , 20b according to the shape of the 2nd , an eight with square loops. There are a large number of such coil pairs 20a , 20b nested in one another, preferably on a bobbin 21 educated. The coil former 21 can be, for example, a film or a printed circuit board. The pairs of coils can be attached to it as wire coils, for example glued or printed on as paste.

In the coil arrangement of the 3rd are a first number of coil pairs 20a such on the bobbin 21 arranged that their axes are inclined 45 ° counterclockwise from the vertical and parallel rows with these pairs of coils 20a are formed, with coils lying in a row 20a with the coil vertices lying on one axis 23 , 24th adjoin each other and the coil pairs 20a the adjacent row are offset by a single coil and with their coil apexes furthest from their axis 25th , 26 border on each other.

This results in a field of individual coils of the first number of coil pairs 20a , between the individual coils of which the area of an individual coil remains free.

These free areas are with individual coils of the coil pairs of the second number of coil pairs 20b occupied, the axes of these coil pairs 20b the second number of coil pairs by 45 ° clockwise from the vertical, ie by 90 ° with respect to the axes of the coil pairs 20a the first number of coil pairs is inclined. The axes of the coil pairs 20a are therefore perpendicular to the axes of the coil pairs 20b .

In addition there is a point of symmetry 14 of a pair of coils 20a the first number of coil pairs from a point of symmetry 14 of a pair of coils 20b the second number of coil pairs spaced apart by a single coil and vice versa. So the symmetry points of the coil pairs never fall 20a the first number of coil pairs with that of the coil pairs 20b the second number of coil pairs together.

It is thus achieved in the manner according to the invention that an object 22 that is on a point of symmetry 14 of a pair of coils which is a number of pairs of coils and therefore cannot be detected by the latter, is in any case detected by the directly adjacent pair of coils the other number of pairs of coils, since its individual coils are at a different distance from the object due to this arrangement 22 have, resulting in different changes in the magnetic field penetrating its individual coils and therefore a voltage or a current can be detected.

The 4th shows a similar arrangement of the coil pairs as in the 3rd , where all coil pairs by 45 ° compared to the arrangement 3rd are rotated. The coil pairs are not specified because they match those of 3rd correspond.

In the 5 is a device for the inductive transmission of energy with a primary coil 31 on a base plate 30th and a secondary coil 34 on a vehicle plate 33 shown in the between the primary and secondary coils 31 m 34 a coil arrangement according to the invention with pairs of coils 20a , 20b on a bobbin 21 for example according to 3rd . or 4th is arranged. The coil pairs 20a , 20b are caused by a magnetic field 35 penetrated, for example by the primary coil 31 is produced. It would also be possible to use the magnetic field 35 by means of the secondary coil 34 to generate in order to recognize magnetically effective, in particular metallic, foreign objects.

With this device, an object can also be detected when positioned on a point of symmetry or a line of symmetry, although coil pairs are used in which, in the case of a homogeneous magnetic field generated by the primary coil, no voltage at its connections can be detected without interference from a foreign object.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 2013/0169062 A1 [0002, 0003]

Claims (8)

Coil arrangement with a plurality of coil pairs (1; 10; 20a, 20b) arranged in one plane, the individual coils of which are each designed and connected to one another such that the currents (3, 4; 12, 13) induced in them by a magnetic field are directed in opposite directions and are of the same size, characterized in that the coil pairs (1; 10; 20a, 20b) are of point symmetry and are arranged such that they are oriented relative to one another in such a way that a magnetically active object (22) located at the point of symmetry (14) of a pair of coils (1 ; 10; 20a, 20b), the equality of the currents (3, 4; 12, 13) at least one adjacent pair of coils (1; 10; 20a, 20b) is canceled. Coil arrangement after Claim 1 , characterized in that the individual coils all have the same shape and size. Coil arrangement according to one of the preceding claims, characterized in that the lines (2) of the individual coils of a pair of coils (1; 10; 20a, 20b) are guided in the form of an eight. Coil arrangement after Claim 3 , characterized in that the axes (15) of two adjacent pairs of coils (20a, 20b) passing through the loops and the loop connection point (14) of the eight, the loop connection points (14) of which are separated from one another by an eight loop, are perpendicular to one another. Coil arrangement according to one of the preceding claims, characterized in that it is formed on a coil carrier (21). Coil arrangement after Claim 5 , characterized in that the coil pairs (20a, 20b) are printed on the coil carrier (21). Device for the inductive transmission of energy with a primary and a secondary coil, between which a coil arrangement according to one of the Claims 1 to 6 is arranged. Device after Claim 7 that the coil arrangement is arranged on the primary coil.

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