WO2013156168A2

WO2013156168A2 - Coil unit and device for the inductive transfer of electrical energy

Info

Publication number: WO2013156168A2
Application number: PCT/EP2013/052014
Authority: WO
Inventors: Mathias Wechlin; Pascal Asselin; Andrew Green; Niklas Endler
Original assignee: Conductix-Wampfler Gmbh
Priority date: 2012-04-17
Filing date: 2013-02-01
Publication date: 2013-10-24
Also published as: WO2013156168A3; DE102012103302A1; DE112013002071A5; DE102012103302B4

Abstract

The invention relates to a coil unit (1; 14; 15; 23; 28; 30; 34) with a housing (2) and a coil (6) integrated therein for the inductive transfer of electrical energy to a secondary coil of a movable electric consumer, in particular of an electric vehicle, and to a device for the inductive transfer of electrical energy between a primary coil of a stationary primary coil unit and a secondary coil of a movable consumer, in particular of an electric vehicle. The invention solves the problem of improving the operational reliability of an inductive energy transfer system regarding objects reaching the coil unit by proposing a coil unit in which the housing (2) has at least one apex (12; 24) on a visible side (3), from which inclined flanks (13; 25, 26) slope towards a housing base (4), and a device for the inductive transfer of electrical energy between a primary coil of a stationary primary coil unit and a secondary coil of a movable consumer, in particular of an electric vehicle, the primary coil unit being configured as such a coil unit (1; 14; 15; 23; 28; 30; 34).

Description

Coil unit and device for

inductive transmission of electrical energy

The invention relates to a coil unit according to the preamble of claim 1 and a device for inductive transmission of electrical energy according to the preamble of claim 17.

In the field of inductive energy transmission to mobile consumers, such as electric vehicles such as automobiles or trucks, it is known to load their vehicle battery via a stationary installed primary coil of a charging station and arranged on the vehicle floor secondary coil. In this case, the primary coil is usually arranged on or in the roadway, even on public parking lots, charging areas of gas stations or in the garage of the vehicle owner. For charging, the vehicle is driven over the primary coil, that the arranged in the vehicle secondary coil is aligned as well as possible on the primary coil.

Due to the high power to be transmitted between the primary and secondary coil occur in a spatial area around the primary coil or its housing magnetic alternating fields high field strength and flux density. If electrically conductive objects lie in this area on the housing of the primary coil, eddy currents are induced in these objects, which are heated depending on the material, duration of the introduction into the magnetic field, alignment with the field and the magnitude of the field strength. In this case, the objects can become so hot that damage to the housing of the primary coil and at worst also the primary coil itself is to be feared. There is also a risk of injury when people reach for such a heated object.

An example of a coil arrangement with recessed into the ground primary coil, in which the above problem may occur, disclosed in DE 10 2009 033 236 AI. There, the housing of the primary coil is flat and flat, so that when there is an electrically conductive object, such as a can, screws, rings, etc., there is the danger described above that the object is very heated. While charging the vehicle, this usually covers the primary coil, so that at most the housing of the primary coil can be damaged, but no one can reach for the object immediately. Drives the vehicle after loading away from the primary spool, the then still very hot object is lying there open so that anyone can grab it.

The device thereover attempts to solve the above problem by providing that the stationary unit of the device for inductive transmission of electrical energy from the stationary unit to a vehicle adjacent thereto has means for detecting the presence of an object within a predetermined space at least equal to that during the Energy transfer between the primary inductance and the secondary inductance lying space comprises comprises. In this case, the detection device comprises at least one non-contact sensor and an evaluation device connected to the sensor, wherein at least the sensor of the detection device is installed in or attached to the same housing as the primary coil of the energy transmission device and an ultrasonic, radar or infrared sensor or an electronic Image sensor can be. If an object is detected, a warning signal can be output there as a sensible reaction, the power supply of the primary inductance deactivated and the current supply reactivated when the foreign object re-emerges from the field region.

This solution is associated with a high and thus expensive metrological effort, wherein the presence of an object, if necessary, the energy transfer can not be performed or only with reduced power.

The subsequently published DE 10 2010 063 665 AI discloses a method for radar-based guidance of an electric car to a charging position with at least one feed coil and radar sensors. The stationary feed coil and the radar sensors are arranged under a loading mat incorporated in the road surface. The antennas of the radar sensors stand out over the loading mat and are surrounded by a raised potting compound, so that they can be run over by a car without damage.

The object of the present invention is to overcome the abovementioned disadvantages and to provide an initially mentioned coil unit and device for the inductive transmission of electrical energy, which improve the operational safety of an inductive energy transmission system with respect to objects arriving at or on the coil unit. This object is achieved by the invention with a coil unit having the features of claim 1 and a device for inductive transmission of electrical energy with the features of claim 17. Advantageous embodiments and expedient developments of the invention are specified in the subclaims.

According to the invention, the coil unit mentioned in the introduction is characterized in that the housing has at least one vertex on a visible side, from which inclined flanks drop toward a housing bottom.

In an advantageous embodiment, the inclination of the flanks may increase from the vertex to the housing bottom at least in sections, so that a rolling object increasingly accelerates or slides off, wherein in a preferred development, the inclination may increase continuously.

In an alternative advantageous embodiment, the inclination of the flanks from the apex to the housing bottom remain unchanged, so that even from the apex, a relatively strong inclination can be provided. Preferably, the housing may have the shape of a dome or a pyramid, wherein a floor plan of the dome or pyramid is round, quadrangular, pentagonal, hexagonal, octagonal or polygonal. Advantageously, the side skirts can form edges from the apex to the housing bottom. In an alternative embodiment, the apex may be a closed apex line and the flanks may be formed by outer flanks sloping outwards from the apex line and inner flanks sloping inwards towards an inner region of the housing. Preferably, the Außenfianken and the inner edges can be inclined and / or curved differently strong. As a result, a preferred direction can be specified for objects reaching directly on the crest line, whether they roll on the outer flanks or the inner flanks or slide off. Preferably, the housing may have an annular plan and a convex cross-section or triangular cross-section, as shown in the embodiments in FIGS. 4 to 7. To be able to prevent even better an object in the region of the highest field strengths remaining above the coil windings of the coil, the apex line can advantageously extend above the coil windings. In this case, the crest line can preferably simulate the form of the coil seen from above. For example, the apex line may be annular in a toroidally or helically wound coil, or hexagonal in a hexagonal shaped coil.

In an advantageous development, the apex line can be partially interrupted, so that it forms a chain of apex line sections. In this way, it may possibly be prevented that especially small flat objects remain lying on the crest line, since the objects not only tilt in the direction of the outer or inner flanks, but additionally also in the direction of the crest line.

Advantageously, in the interior region of such a coil unit, a collecting container extending under the housing bottom, in particular made of a heat-insensitive material, can be provided. In a favorable development, a circumferential depression, e.g. a trench, in particular of a heat-insensitive material, are provided. In the collecting container and / or the depression can then fall from the flanks rolling or sliding objects. Preferably, the circumferential recess and / or the collecting container can be provided with one or more retaining devices, which prevent a picked-up object can be easily removed again.

In an advantageous embodiment, the vertex can be arranged directly above the coil. This means that the vertex is spatially located in an area that is located above the coil, and not in large lateral distance. Preferably, the apex may be concentric with the coil so that an article may slide away from a central region above the coil. More preferably, the housing completely surround the coil, the coil is thus integrated between the housing bottom and the visible side of the housing.

According to the invention, the device mentioned above for the inductive transmission of electrical energy between a primary coil of a stationary primary coil unit and a secondary coil of a mobile consumer, in particular an electric vehicle, characterized in that the primary coil unit is formed as a coil unit above and below described coil unit.

Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings. These show

Fig. 1 shows a cross section through a first embodiment of an inventive

Coil unit;

2 shows a cross section through a second embodiment of an inventive

Coil unit;

Fig. 3 shows a cross section through a third embodiment of an inventive

Coil unit;

4 shows a cross section through a fourth embodiment of an inventive

Coil unit;

Fig. 5 shows a cross section through a fifth embodiment of an inventive

Coil unit;

Fig. 6 shows a cross section through a sixth embodiment of an inventive

Coil unit;

Fig. 7 shows a cross section through a seventh embodiment of an inventive

Coil unit;

8 shows a schematic diagram of the magnetic field course of the coil units according to the invention.

A device according to the invention for the inductive transmission of electrical energy to an electric vehicle has a coil unit 1 according to the invention with a housing 2, which is installed with a housing bottom 4 facing away from its visible side 3 stationary on the roadway floor 5. In the housing 3, a coil 6 is integrated, whose Coil windings 7 seen from above spiral in a lying substantially parallel to the housing bottom winding plane 8 lie. Also, the coil unit 1 in Fig. 1, not shown field guiding elements for guiding the magnetic field. The configuration of the coil unit just described is known per se and can be modified in many ways. In the present device for inductive transmission of electrical energy to an electric vehicle, the coil 6 is generally referred to as a primary coil which transmits inductive energy to a mounted on the electric vehicle secondary coil. FIG. 8 shows schematically a diagram of the magnetic field profile of the coil unit 1 according to the invention shown in FIG. 2, which however also applies correspondingly to the coil units according to the invention in FIGS. 2 to 7. In this case, the winding plane 6 is perpendicular to the horizontal, parallel to the roadway bottom X-axis of Fig. 8. The flowing through the coil windings 7 generates a current through a plurality of magnetic field lines 9 qualitatively indicated magnetic field profile 10, wherein the current through the in Fig. 1 right coil windings 7 in the plane of the paper and out through the left in Fig. 1 coil windings 7 from the paper plane.

Since the magnetic field is an alternating field, eddy currents corresponding to the magnetic field strength existing at this location are generated in an electrically conductive article 11 (FIG. As a result, the object 11 is heated, so that the magnetic field profile 10 corresponds approximately to the heating potential for such an object 11. If the object 11 is close to the coil angles 7, it is heated the most, while in the area between the coil windings 7 the heating is lower. At the edge of the coil unit 1, the heating potential drops sharply relatively quickly, so that starting at a certain distance from the coil unit 1, heating is scarcely to be expected any more.

However, if the object 11 is located very close to the coil windings 7, for example if it lies on the visible side 3 of the coil unit 1, the object 11 can be heated very strongly, which on the one hand poses a danger to persons who want to reach for it, and also may cause damage to the coil unit. Just when the article 11 is a piece of jewelry with high gold or silver content, it will heat up very much due to the good electrical conductivity of these materials. In order to reduce this risk, it is not attempted in the present case, as in the abovementioned DE 10 2009 033 236 A1, to detect an object located in the magnetic field region of the coil unit, in order then to reduce or completely switch off the power of the coil, if this is the case Operational reliability reduced. Rather, should be prevented in the present invention that an object at all in the warming endangered area remains on the coil unit and is easily accessible.

For this purpose, the first embodiment of the coil unit according to the invention shown in Fig. 1 provides that the visible side 3 of the housing 2 has no planar surface, but the shape of a dome with a convex cross section shown in Fig. 1, a highest vertex 12 and from this to As a result, as indicated in FIG. 1, an object 11 reaching the visible side 3 can roll toward the edge of the housing 2 and thus comes out of the region of the coil unit 1 prone to overheating.

Advantageously, in the present embodiment, the side skirts 13 descend from the apex 12 with increasing slope towards the housing bottom 4, so that articles coming from this region of the visible side of increasing speed can roll out or slide, particularly into the region which is particularly prone to warming near the coil windings 5.

In the following, in the other embodiments according to FIGS. 2 to 7 corresponding parts are labeled with corresponding designations and designated by corresponding reference numerals.

A second embodiment of a coil unit 14 according to the invention shown in FIG. 2 has a conical housing 2 with a triangular cross-section. In contrast to the embodiment shown in Fig. 1, this has the advantage that the slope of the Seitenfianken 13 in the region of the apex 12 is steeper. Therefore, the apex 12 is sharpened, so that objects can easily roll on the Seitenfianken 13 or slide off. Compared with the embodiment shown in FIG. 1, however, it is disadvantageous in the embodiment shown in FIG. 2 that the coil unit 14 builds higher with the same horizontal extent. Since the height of the coil unit 14 by the ground clearance of Vehicles is determined, depending on the horizontal extent of the coil unit 14 only certain inclinations of the side edges 13 can be achieved.

Instead of those shown in the embodiments of FIGS. 2 and 3, in plan view circular coil unit 1 and 14, other shapes can be selected, for example, the coil unit in plan view be triangular, square, pentagonal, hexagonal, octagonal or polygonal, on the one hand has the advantage that objects do not remain lying on the then existing edges between adjacent side edges. The disadvantage is that on the surface areas located between the edges, a flat surface is created, lie on the flat objects easier.

A third embodiment of a coil unit 15 according to the invention, shown in FIG. 3, corresponds to the embodiment shown in FIG. 1, wherein a recess in the form of a trench 16 is additionally arranged circumferentially around the housing 2 in the lane 5. The trench 16 is lined with a heat-insensitive material, so that an object 11 rolling from the visible side 3 of the housing 2 falls into the trench 16. Even if the object 11 has already been heated or the magnetic field still present in the trench 16 is heated, this is done without risk of damaging the coil unit 15 or the roadway 5.

In an advantageous development of the coil unit 1 shown in FIG. 3, as indicated in FIG. 3 on the right, the upwardly open trench side 17 of the trench 16 can be closed by a retaining device so that an object can fall from above into the trench 16 , but then it can not easily be removed from above. An example of this may be comb-like interlocking bristles 18 or narrow strips of hard plastic attached to the upper ends of sidewalls of the trench 16. Rolls an object 11 from the visible side 3 of the housing 2, it falls because of its own weight and its kinetic energy through the bristles 18 in the trench 16, but can not be easily removed and also is not visible from above.

Alternatively or additionally, as a retaining device and bars are provided between which at least narrow objects such as coins, rings, etc. can fall through. Likewise, alternatively or additionally arranged on the edge of the trench 16 flaps are provided which cover the open trench side 17 and are held by spring force in this position.

Another embodiment of a retaining device can have an inlet channel 19 in the trench 16, as indicated on the right in FIG. 3, so that objects are guided on a guide wall 20 against a baffle 21 inclined against the inclination of the guide wall 20 on the outside trench bottom. A rolling or slipping object then bounces off the baffle 21 and into the space of the trench 16 below the guide wall 20. Since the trench 16 is equipped with a handle protection element 22 on its outer side, the object that has disappeared in the trench 16 can be manually removed no longer be removed or only with great difficulty. A fourth embodiment of a coil unit 23 according to the invention shown in FIG. 4 has a cup-like shape with an annular cross-section, thus having a circular circumferential top crest line 24 with outer flanks 25 and inner flanks 26 sloping down therefrom. An object located in the region of the apex line 24 the housing 2 falls, can thus either slide off to the outside or roll or slide into a formed by the inner edges 26 central funnel-shaped inner region 27. This has the advantage that the flanks 26, 27 can be kept significantly steeper than in the embodiments according to FIGS. 1 to 3, so that the remaining of an object on the visible side 3 of the housing 2 can be well prevented. If an object falls into the inner region 27 between the coil windings 7, then there still prevails a relatively high magnetic field, which causes greater heating than in the case of an object sloping outwards. Nevertheless, this advantageously ensures that an object does not come to rest on the housing 2 and can damage it.

In order to achieve an additional security in the embodiment shown in FIG. 4 and to make it difficult to access an object rolled off from the housing 2 into the inner region 27, a fifth embodiment of a coil unit 28 according to the invention shown in FIG. 5 has one in the roadway 5 let in, cup-shaped collecting container 29, in which a falling into the interior region 27 or rolling object falls. The collecting container 29 is again heat-insensitive Material lined or consists entirely of this, so that heating of the object by the existing between the coil windings 7 magnetic field is harmless.

A sixth embodiment of a coil unit 30 according to the invention shown in FIG. 6 essentially corresponds to the embodiment shown in FIG. 5, wherein in the embodiment shown in FIG. 6, the flanks 25, 26 are not curved convexly with increasing inclination, but according to the embodiment shown in FIG 2 have a triangular cross section. This results in principle in the same advantages and disadvantages compared to the embodiment shown in Fig. 5 as between the embodiments of FIGS. 1 and 2. However, the coil unit 30 shown in Fig. 6 also has the advantage as the coil unit shown in Fig. 5 28 compared to the embodiments shown in FIGS. 1 and 2, namely that at the same height, the flanks 25, 26 can be significantly more inclined, so that an object even more easily slides off or unrolls. 5 and 6, the collecting container 29 can be provided with a retaining device, for example in the form of intermeshing hard rubber bristles, which prevents engagement and possibly removal of the object. Also, a retaining device indicated in Fig. 6 may be formed so that the inner edge 26 are extended by a funnel-shaped guide wall 31 at the upper edge of the collecting container 29, so that an incident object preferably falls into an off-center region of a bottom 32 of the collecting container 29. Removal of the object is then only with difficulty possible due to the relatively small opening of this retaining device and the funnel-shaped downwardly facing guide wall 31.

The fact that the object comes to rest as possible in an off-center region of the bottom 32, can be further enhanced by the fact that in the center of the bottom 32 an advantageously hemispherical, conical or pyramidal impact body 33 is provided, the an incidental object in a below the guide wall 31 lying region of the collecting container 29 derived.

A seventh embodiment of a coil unit 34 according to the invention shown in FIG. 7 combines the trench 16 shown in FIG. 3 with the coil unit 28 according to FIG. 5 with the respective advantages described for these exemplary embodiments. Preferably, the above-described material of the trench 16, the collecting container 29 and / or the retaining devices described above may consist partly or entirely of heat-insensitive and / or non-electrically conductive and / or non-magnetically conductive materials.

reference numeral

1 coil unit Fig. 1

2 housings

3 visible side

4 caseback

5 lane

6 (primary) coil

7 coil windings

8 winding level

9 magnetic field lines

10 magnetic field course

1 1 item

12 vertex

13 side flanks

14 coil unit Fig. 2

15 coil unit Fig. 3

16 ditch

17 open ditch side

18 bristles

19 inlet channel

20 guide wall

21 baffle

22 handle protection element

23 coil unit Fig. 4

24 crest line

25 outer edges

26 inner flanks

27 indoor area

28 coil unit Fig. 5

29 collection container

30 coil unit Fig. 6

31 funnel-shaped guide wall

32 Bottom of the collection container

33 baffles

34 coil unit Fig. 7

Claims

claims

A coil unit (1; 14; 15; 23; 28; 30; 34) comprising a housing (2) and a coil (6) integrated therein for inductive transmission of electrical energy to a secondary coil of a mobile electrical load, in particular an electric vehicle in that the housing (2) has on a visible side (3) at least one apex (12; 24), from which inclined flanks (13; 25, 26) drop towards a housing bottom (4).

2. coil unit (1; 15; 23; 28; 34) according to claim 1, characterized in that the inclination of the flanks (13; 25, 26) from the apex (12; 24) to the housing bottom (4) increases at least in sections.

3. coil unit (14; 30) according to claim 1, characterized in that the inclination of the flanks (13; 25, 26) from the vertex (12; 24) to the housing bottom (4) remains unchanged.

4. Coil unit (1; 14; 15; 23; 28; 30; 34) according to one of claims 1 to 3, characterized in that the apex is delimited by a vertex (12) and the flanks by side flanks (12) falling from the apex (12). 13) are formed.

5. coil unit (1; 14; 15; 23; 28; 30; 34) according to one of claims 1 to 4, characterized in that the housing (2) has the shape of a dome (1; 15) or a pyramid (14) wherein a floor plan of the dome (1; 15) or the pyramid (14) is round, quadrangular, pentagonal, hexagonal, octagonal or polygonal.

6. coil unit (23; 28; 30; 34) according to one of claims 1 to 3, characterized in that the apex is a closed apex line (24) and the flanks by from the apex line (24) outwardly sloping outer edges (25) and an inner region (27) of the housing (2) inwardly sloping inner edges (26) are formed.

7. coil unit (23; 28; 34) according to claim 6, characterized in that the Außenfianken (25) and the inner edges (26) are inclined and / or curved different degrees.

The coil unit (23; 28; 30; 34) according to claim 6 or 7, characterized in that the housing (2) has an annular plan view and a convex cross section (23; 28; 34) or triangular cross section (30).

9. coil unit (23, 28, 34) according to one of claims 6 to 8, characterized in that the apex line (24) above coil windings (7) of the coil (6).

10. coil unit (23; 28; 34) according to one of claims 6 to 9, characterized in that the apex line (24) is partially interrupted.

11. Coil unit (23; 28; 30; 34) according to one of claims 5 to 10, characterized in that in the inner region (27) under the housing bottom (4) reaching collecting container (29), in particular of a heat-insensitive material is provided ,

12. coil unit (15; 34) according to any one of the preceding claims, characterized in that around the housing (2) is provided a circumferential recess (16), in particular of a heat-insensitive material.

13. Coil unit (15; 34) according to claim 11 or 12, characterized in that the circumferential recess (16) and / or the collecting container (29) with a retaining device (18; 19-22; 31, 33) are provided.

14. coil unit (15; 34) according to any one of the preceding claims, characterized in that the apex (12; 24) is arranged directly above the coil (6).

15. coil unit (15; 34) according to one of the preceding claims, characterized in that the apex (12; 24) is arranged concentrically to the coil (6).

16. coil unit (15; 34) according to one of the preceding claims, characterized in that the housing (2) completely surrounds the coil (6).

17. Device for inductive transmission of electrical energy between a primary coil of a stationary primary coil unit and a secondary coil of a mobile consumer, in particular an electric vehicle, characterized in that the primary coil unit as a coil unit (1; 14; 15; 23; 28; 30; one of claims 1 to 16 is formed.