DE102012103302A1 - Coil unit and device for inductive transmission of electrical energy - Google Patents

Abstract

The invention relates to 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 movable electrical load, in particular an electric vehicle , And a device 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. The invention solves the problem of improving the operational safety of an inductive energy transmission system with respect to objects arriving at or on the coil unit, with a coil unit, in which the housing (2) has at least one vertex (12, 24) on a visible side (3), falling from the inclined flanks (13; 25, 26) towards a housing bottom (4), and by a 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, in which the primary coil unit is formed as such a coil unit (1; 14; 15; 23; 28; 30; 34).

Description

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 14.

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 assembly having a sunken primary coil in which the above problem may occur is disclosed in US Pat DE 10 2009 033 236 A1 , There, the housing of the primary coil is flat and flat, so that in an electrically conductive object lying on it, for. As a can, screws, rings, etc., the danger described above is that the object is heated very much. 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. If the vehicle leaves the primary coil after loading, the object, which is still very hot, is lying 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 or mounted in 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 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 14. Advantageous embodiments and expedient developments of the invention are specified in the dependent claims.

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

In an alternative advantageous embodiment, the inclination of the flanks from the vertex to Housing back 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 flanks 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 outer flanks and the inner flanks can be inclined and / or curved at different degrees. 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 in the embodiments in 4 to 7 shown.

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 recess, for. As 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.

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

1 a cross section through a first embodiment of a coil unit according to the invention;

2 a cross section through a second embodiment of a coil unit according to the invention;

3 a cross section through a third embodiment of a coil unit according to the invention;

4 a cross section through a fourth embodiment of a coil unit according to the invention;

5 a cross-section through a fifth embodiment of a coil unit according to the invention;

6 a cross section through a sixth embodiment of a coil unit according to the invention;

7 a cross section through a seventh embodiment of a coil unit according to the invention;

8th a schematic diagram of the magnetic field characteristic 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 according to the invention 1 with a housing 2 on, which with one of his visible side 3 opposite housing bottom 4 stationary on the roadway floor 5 is installed. In the case 3 is a coil 6 integrated, whose coil windings 7 seen from above spiral in a lying substantially parallel to the housing bottom winding plane 8th lie. Also, the coil unit 1 in 1 not shown field guide 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 electrical Energy on an electric vehicle becomes the coil 6 usually referred to as a primary coil, which transmits inductive energy to a mounted on the electric vehicle secondary coil.

8th schematically shows a diagram of the magnetic field course of in 2 illustrated coil unit according to the invention 1 , which, however, according to the coil units according to the invention in 2 to 7 applies. Here is the winding plane 6 perpendicular to the horizontal, parallel to the road bottom X-axis of 8th , The through the coil windings 7 flowing current generates one by several magnetic field lines 9 qualitatively indicated magnetic field course 10 , where the current through the in 1 right coil windings 7 into the paper plane and through the in 1 left coil windings 7 tucked out of the paper plane.

Since the magnetic field is an alternating field, are in an electrically conductive object 11 ( 1 ) generates eddy currents in the region of the magnetic field corresponding to the magnetic field strength existing at this location. This will be the object 11 heated so that the magnetic field 10 in about the warming potential for such an object 11 equivalent. Is the object located? 11 next to the coil angles 7 We heated it the most while in the area between the coil windings 7 the heating is lower. At the edge of the coil unit 1 then the heating potential drops relatively quickly, so that at a certain distance from the coil unit 1 hardly any more warming is to be expected.

Is the object located? 11 but very close to the coil windings 7 , he lies for example on the visible side 3 the coil unit 1 so can the object 11 be heated very strong, which on the one hand represents a threat to persons who want to reach for him, and may also damage the coil unit result. Especially if the object 11 is a piece of jewelery with a high gold or silver content, it will heat up very much due to the good electrical conductivity of these materials.

To reduce this risk is not present here as in the above DE 10 2009 033 236 A1 Attempts to detect an object located in the magnetic field region of the coil unit, and then possibly to reduce the power of the coil or turn off completely, as this reduces the operational reliability. 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.

This is what the in 1 shown first embodiment of the coil unit according to the invention before that the visible side 3 of the housing 2 has no flat surface, but the shape of a dome with an in 1 shown convex cross section, a highest vertex 12 and from this to the case back 4 and thus to the roadway 5 sloping side edges 13 , This can, as in 1 indicated, one on the visible side 3 passing object 11 to the edge of the case 2 Rolling and thus comes from the warming endangered area of the coil unit 1 ,

Advantageously fall in the present embodiment, the side edges 13 from the vertex 12 starting with increasing slope to the housing bottom 4 out so that especially in the particular warming endangered area near the coil windings 5 rolling out or sliding objects from this area of the visible side of increasing speed.

In the following are in the other versions of the 2 to 7 corresponding parts named with corresponding designations and designated by corresponding reference numerals.

An in 2 illustrated second embodiment of a coil unit according to the invention 14 has a conical housing 2 with triangular cross section. Unlike the in 1 illustrated embodiment, this has the advantage that the slope of the side edges 13 in the area of the vertex 12 steeper. That's why the vertex is 12 sharpener, making items easier on the side flanks 13 can roll off or slide off. Opposite the in 1 shown embodiment is disadvantageous in the 2 shown embodiment, however, that the coil unit 14 builds higher at the same horizontal extent. As the height of the coil unit 14 determined by the ground clearance of the vehicles, depending on the horizontal extent of the coil unit 14 only certain inclinations of the side flanks 13 be achieved.

Instead of in the embodiments according to 2 and 3 shown, in plan view circular coil unit 1 respectively. 14 can be selected other shapes, for example, the coil unit in plan view triangular, square, pentagonal, hexagonal, octagonal or polygonal, which on the one hand has the advantage that remain on the then existing edges between adjacent side edges objects. The disadvantage is that on the surface areas located between the edges, a flat surface is created, lie on the flat objects easier.

An in 3 illustrated third embodiment of a coil unit according to the invention 15 corresponds to the in 1 shown embodiment, where there in addition in the roadway 5 around the case 2 encircling a depression in the form of a trench 16 is arranged. The ditch 16 is lined with a heat-resistant material, leaving one from the visible side 3 of the housing 2 rolling object 11 in the ditch 16 falls. Even if the object 11 was already warmed or still in the ditch 16 existing magnetic field is heated, this is done without risk of damage to the coil unit 15 or the roadway 5 ,

In an advantageous embodiment of in 3 shown coil unit 1 can, as in 3 indicated on the right, the trench side open at the top 17 of the trench 16 be closed by a retaining device so that an object from the top of the ditch 16 can fall, but then can not be taken out easily from above. An example of this may be comb-like interlocking bristles 18 or narrow strips of hard plastic, which at the upper ends of side walls of the trench 16 are attached. Rolls an object 11 from the visible side 3 of the housing 2 it falls due to its own weight and its kinetic energy through the bristles 18 in the ditch 16 but it can not be easily taken out and 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, at the edge of the trench 16 arranged flaps are provided which the open trench side 17 Cover and held by spring force in this position.

Another embodiment of a restraint device may be in the trench 16 , as in 3 indicated on the right, an inlet channel 19 so that objects on a guide wall 20 against one against the inclination of the guide wall 20 inclined baffle 21 be conducted on the outside trench floor. A rolling or sliding object then bounces off the baffle 21 from and into the under the guide wall 20 located room of the trench 16 , Since the ditch 16 on its outer side with a handle protection element 22 equipped in the ditch can 16 disappeared object by hand no longer or only with great difficulty be removed.

An in 4 shown fourth embodiment of a coil unit according to the invention 23 has a cup-like shape with a circular cross-section above, so has a circular circumferential highest apex line 24 with sloping outer edges 25 and inside flanks 26 , An object that is in the area of the crest line 24 on the case 2 falls, can either slide off to the outside or rolling or in through the inner edges 26 formed central funnel-shaped interior area 27 slide. This has the advantage that the flanks 26 . 27 can be kept significantly steeper than in the following 1 to 3 so that the lying of an object on the visible side 3 of the housing 2 can be prevented well. If an object falls into the interior 27 between the coil windings 7 , so there is still a relatively high magnetic field, which causes a stronger warming than an object falling outwards. Nevertheless, this advantageously ensures that an object is not on the housing 2 comes to rest and can damage this.

To be at the in 4 shown embodiment to achieve additional security and access to one of the housing 2 in the interior 27 To make it difficult to roll off the article, has an in 5 shown fifth embodiment of a coil unit according to the invention 28 According to the invention in the roadway 5 sunken cup-shaped collecting container 29 in which one is in the interior 27 derivative or rolling object falls. The collection container 29 is in turn lined with or made of a heat-insensitive material, so that heating of the article by the between the coil windings 7 existing magnetic field is harmless.

An in 6 illustrated sixth embodiment of a coil unit according to the invention 30 is essentially the same as in 5 shown embodiment, wherein in the in 6 shown embodiment, the flanks 25 . 26 are not convexly curved with increasing inclination, but according to the in 2 embodiment shown have a triangular cross-section. This results in principle the same advantages and disadvantages compared to in 5 shown embodiment as between the embodiments 1 and 2 , In the 6 shown coil unit 30 However, it also has the advantage of being in 5 shown coil unit 28 opposite the in 1 and 2 shown embodiments, namely that the same height the flanks 25 . 26 can be significantly more inclined, so that an object even more easily slides off or rolls off.

Also at the in 5 and 6 shown coil unit 28 respectively. 30 can the collection container 29 with a retaining device, for example in the form of interlocking Hard rubber bristles are provided, which prevents intervention and possibly removing the object. Also, an in 6 indicated restraint device be designed so that the inner edge 26 through a funnel-shaped guide wall 31 at the top of the collection container 29 be extended so that an incidental object preferably in an off-center area of a floor 32 of the collection container 29 falls. Removal of the article is then due to the relatively small opening of this retainer and the funnel-shaped downwardly facing guide wall 31 only more difficult.

That the object is possible in an off-center area of the ground 32 can be reinforced by the fact that in the center of the soil 32 an advantageous hemispherical, conical or pyramidal impact body 33 is provided, the an incidental object in an under the guide wall 31 lying area of the collecting container 29 derives.

An in 7 shown seventh embodiment of a coil unit according to the invention 34 combines the in 3 shown ditch 16 with the coil unit 28 to 5 with the advantages described in each case for these embodiments.

Preferably, the above-described material of the trench 16 , the collection container 29 and / or the retention devices described above consist partly or wholly of heat-insensitive and / or non-electrically conductive and / or non-magnetically conductive materials.

LIST OF REFERENCE NUMBERS

1

coil unit 1

2

casing

3

Main page

4

caseback

5

roadway

6

(Primary) coil

7

coil windings

8th

the winding plane

9

magnetic field lines

10

magnetic field course

11

object

12

vertex

13

side flanks

14

coil unit 2

15

coil unit 3

16

dig

17

open trench side

18

bristles

19

inlet channel

20

guide wall

21

baffle wall

22

Handle protection element

23

coil unit 4

24

crest line

25

outer flanks

26

inner flanks

27

interior

28

coil unit 5

29

receptacle

30

coil unit 6

31

funnel-shaped guide wall

32

Bottom of the collection container

33

baffle

34

coil unit 7

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely 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.

Cited patent literature

• DE 102009033236 A1 [0004, 0031]

Claims (14)

Coil unit ( 1 ; 14 ; 15 ; 23 ; 28 ; 30 ; 34 ) with a housing ( 2 ) and a coil integrated therein ( 6 ) for the inductive transmission of electrical energy to a secondary coil of a movable electrical load, in particular an electric vehicle, characterized in that the housing ( 2 ) on a visible side ( 3 ) at least one vertex ( 12 ; 24 ), from which inclined flanks ( 13 ; 25 . 26 ) to a housing bottom ( 4 ) fall off. Coil unit ( 1 ; 15 ; 23 ; 28 ; 34 ) 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 ) increases at least in sections. 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. Coil unit ( 1 ; 14 ; 15 ; 23 ; 28 ; 30 ; 34 ) according to one of claims 1 to 3, characterized in that the vertex is defined by a vertex ( 12 ) and the flanks through from the vertex ( 12 ) sloping side edges ( 13 ) are formed. Coil unit ( 1 ; 14 ; 15 ; 23 ; 28 ; 30 ; 34 ) according to one of claims 1 to 4, characterized in that the housing ( 2 ) 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. Coil unit ( 23 ; 28 ; 30 ; 34 ) according to one of claims 1 to 3, characterized in that the vertex is a closed apex line ( 24 ) and the flanks through from the crest line ( 24 ) outside sloping outer edges ( 25 ) and to an interior area ( 27 ) of the housing ( 2 ) inwardly sloping inner flanks ( 26 ) are formed. Coil unit ( 23 ; 28 ; 34 ) according to claim 6, characterized in that the outer flanks ( 25 ) and the inner flanks ( 26 ) are differently inclined and / or curved. Coil unit ( 23 ; 28 ; 30 ; 34 ) according to claim 6 or 7, characterized in that the housing ( 2 ) an annular plan and a convex cross section ( 23 ; 28 ; 34 ) or triangular cross-section ( 30 ) having. Coil unit ( 23 ; 28 ; 34 ) according to one of claims 6 to 8, characterized in that the crest line ( 24 ) above coil windings ( 7 ) of the coil ( 6 ) runs. Coil unit ( 23 ; 28 ; 34 ) according to one of claims 6 to 9, characterized in that the crest line ( 24 ) is partially interrupted. Coil unit ( 23 ; 28 ; 30 ; 34 ) according to one of claims 5 to 10, characterized in that in the interior ( 27 ) under the caseback ( 4 ) reaching collecting container ( 29 ), in particular of a heat-insensitive material, is provided. Coil unit ( 15 ; 34 ) according to one of the preceding claims, characterized in that around the housing ( 2 ) a circumferential depression ( 16 ), in particular of a heat-insensitive material, is provided. 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 retention device ( 18 ; 19 - 22 ; 31 . 33 ) are provided. Device 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 as a coil unit ( 1 ; 14 ; 15 ; 23 ; 28 ; 30 ; 34 ) is designed according to one of claims 1 to 13.

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