DE102021206895A1 - Bottom assembly for an inductive charging device - Google Patents

Abstract

The present invention relates to a base assembly (1) for an inductive charging device (2) for inductively charging a motor vehicle (3), which has a coil (5) and a magnetic flux guiding unit (7). Increased efficiency and simple implementation of the base assembly (1 ) are achieved in that the floor assembly (1) has a concrete block (9) in which the coil (5) and/or the magnetic flux guiding unit (7) are accommodated, the coil (5) being on the one upper side (10) of the concrete blocks (9) facing side of the magnetic flux guiding unit (7) and spaced apart from the magnetic flux guiding unit (7). The invention further relates to an arrangement (13) with a track (6) and such a floor assembly (1).

Description

The present invention relates to a base assembly for an inductive charging device for inductive charging of a motor vehicle located above the base assembly, which has a coil and a magnetic flux guiding unit. The invention also relates to an arrangement with a roadway and such a floor assembly.

In the case of at least partially electrically driven motor vehicles, regular charging of an electrical energy store in the motor vehicle is necessary. For this purpose, in principle, a direct electrical connection can be established between the motor vehicle and an external electrical energy source, for example a mains connection. However, this requires manual action by a user.

It is also known to inductively charge the electrical energy store of the motor vehicle, which can be an accumulator, for example. Corresponding charging devices each have an assembly in the motor vehicle and outside of the motor vehicle. In the assembly outside the motor vehicle there is a primary coil which interacts inductively with a secondary coil of the assembly in the motor vehicle in order to charge the motor vehicle. The assembly in the motor vehicle is also referred to as a motor vehicle assembly or "vehicle assembly". The subassembly outside the motor vehicle is usually located below the motor vehicle during operation and is also referred to as the base subassembly or “ground assembly”.

From the EP 3 360 143 A1 a base assembly for an inductive charging device is known, which is arranged below a roadway and covered by the roadway. The floor assembly comprises magnetizable concrete in which a coil is housed. The magnetizable concrete serves to guide the electromagnetic fields generated by the coil to the coil provided on the motor vehicle to be charged.

The present invention is concerned with the task of specifying improved or at least different embodiments for a base assembly for an inductive charging device for inductively charging a motor vehicle located above the base assembly and for an arrangement with such a base assembly and a roadway, which are characterized in particular by a simplified Award implementation and / or increased efficiency.

According to the invention, this object is achieved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

The present invention is based on the general idea of equipping a base assembly for an inductive charging device for inductive charging of a motor vehicle located above the base assembly with a coil and a magnetic flux guidance unit comprising at least one magnetic flux guiding element and accommodating the coil and/or the magnetic flux guidance unit in a concrete block of the base assembly , wherein the coil is arranged on the side of the magnetic flux guiding unit facing the motor vehicle to be charged and spaced in the direction of the motor vehicle to be charged from the magnetic flux guiding unit. The magnetic flux guiding unit serves to guide the electromagnetic alternating field generated by the coil during operation in the direction of the motor vehicle to be charged and thus towards the side of the floor assembly facing away from the magnetic flux guiding unit. The arrangement of the coil at a distance from the magnetic flux guiding unit in this direction leads to a targeted guidance of the alternating electromagnetic field in the direction of the motor vehicle to be charged, with at the same time a weakening of the alternating field being avoided or at least reduced by the arrangement of the coil at a distance from the magnetic flux guiding unit. This results in improved efficiency of the floor assembly and consequently of the inductive charging device. The arrangement of the coil at a distance from the magnetic flux guiding unit also results in a possible separate accommodation and arrangement of the coil and the magnetic flux guiding unit in the base assembly and consequently leads to simplified manufacture and implementation of the base assembly. With the concrete block, it is also possible for a motor vehicle to be able to drive over the floor assembly without any problems, without the floor assembly being damaged and/or destroyed as a result, in particular the coil and the magnetic flux guiding unit. Thus, when the floor assembly and a roadway are arranged, the floor assembly can also be integrated into the roadway at ground level. The ground-level arrangement of the floor assembly in the road leads to a reduced distance between the coil and the motor vehicle to be charged and thus to a further increase in the efficiency of the inductive charging device.

According to the idea of the invention, the base assembly includes the concrete block, the coil and the magnetic flux guiding unit. During operation, the concrete block has a side facing the motor vehicle to be loaded, which is also referred to below as the upper side. The sink is arranged on the side of the magnetic flux guide unit facing the upper side, the coil and the magnetic flux guide unit being arranged at a distance from the upper side. The coil and/or the magnetic flux guiding unit, preferably the coil and the magnetic flux guiding unit, are accommodated in the concrete block, the coil being spaced apart in the distance direction of the magnetic flux guiding unit towards the top of the magnetic flux guiding unit.

During operation, the coil generates an electromagnetic alternating field, which is used in the motor vehicle to be charged for charging the motor vehicle, ie an electrical energy store of the motor vehicle. For this purpose, the coil has at least one coil winding, advantageously a plurality of coil windings. In this case, the coil is advantageously designed as a flat coil. This enables a compact construction of the floor assembly and leads to an increase in the energy density transmitted from the floor assembly to the motor vehicle.

The concrete block is expediently electromagnetically neutral at least in the area between the coil and the upper side, ie it is essentially transparent to the alternating field generated by the coil. In particular, it is ensured that the concrete, with the exception of the coil and the magnetic flux guiding unit contained therein, does not contain any components made of materials that could influence a magnetic field penetrating the concrete, in particular no metals, metal compounds or other electrically conductive substances, e.g. graphite. Thus, due to the electromagnetic neutrality, there is no change or the smallest possible change in the alternating field generated by the coil. It is preferred if the concrete block is completely electromagnetically neutral.

The concrete of the concrete block is expediently produced at least partially, preferably entirely, as so-called water-impermeable concrete, also known as "WU concrete" for short. Such concrete is characterized by the fact that due to a very dense grain structure it can absorb little or no water. As a result, the concrete block remains largely electromagnetically neutral even in a damp or wet environment. The concrete block thus has properties that remain essentially the same and are largely electromagnetically neutral, regardless of the environment.

Alternatively or additionally, the concrete block can be enclosed, preferably completely, by a water-impermeable, electromagnetically neutral coating, which also prevents or at least reduces the absorption of water and other media. The coating is preferably formed from a paint or a hardening filler, which can contain components made of plastic and/or bitumen. The thickness of the coating is advantageously less than 10mm, preferably less than 5mm.

In principle, the coil and/or the magnetic flux guiding unit can be accommodated in the concrete block in any desired manner.

Preferred are embodiments in which the coil and/or the magnetic flux guiding unit are cast in the concrete block. To produce the floor assembly, the coil and/or the magnetic flux guiding unit are placed in a mold and the concrete mass of the concrete block is cast around them. This enables a simple and compact construction of the floor assembly.

As explained, the purpose of the magnetic flux guiding unit is to emit the alternating electromagnetic field generated by the coil from the base assembly in a targeted manner via the upper side. For this purpose, the magnetic flux guiding unit has at least one magnetic flux guiding element, which at least reduces the propagation of the generated electromagnetic fields in the direction of the lower housing part. For this purpose, the at least one magnetic flux guiding element advantageously has a relative magnetic permeability μ _r of at least 2. For this purpose, the respective at least one magnetic flux guiding element can be configured as desired.

Embodiments are advantageous in which at least one of the at least one magnetic flux guiding element, advantageously the respective magnetic flux guiding element, is a ferrite body. This enables an effective, desired guidance of the alternating field generated by the coil during operation.

At the same time, the floor assembly can be manufactured with a reduced weight in this way.

It is also conceivable that at least one of the at least one magnetic flux guiding element is a magnetizable concrete body. The magnetizable concrete body expediently differs from the concrete block.

In preferred embodiments, to protect at least one of the at least one magnetic flux guiding element, advantageously the respective magnetic flux guiding element, a protective jacket is arranged at least in the distance direction between the concrete block and the magnetic flux guiding element, which is mechanically softer than the concrete block and as the magnetic flux guide element. This means that at least one of the at least one magnetic flux guide elements is accommodated in the concrete block, with at least one of the at least one magnetic flux guide elements accommodated in the concrete block, advantageously the respective magnetic flux guide element, being accommodated in a protective casing arranged between the magnetic flux guide element and the concrete block. The protective casing is arranged at least on the side of the magnetic flux guiding element facing the coil and on the side facing away from the coil and is softer than the magnetic flux guiding element. The protective casing thus has both a mechanically damping effect and a decoupling effect with regard to the deformations and thus leads to mechanical protection of the at least one associated magnetic flux guiding element.

The protective casing is expediently electromagnetically neutral at least on the side facing the coil.

The protective casing advantageously has a thickness of at least 2 mm running in the spacing direction on at least one side of the at least one associated magnetic flux guiding element, advantageously on both sides of the at least one associated magnetic flux guiding element. Improved protection of the at least one associated magnetic flux guiding element is thus achieved.

Embodiments are preferred in which at least one of the at least one protective jacket completely encapsulates the at least one associated magnetic flux guiding element. This leads to improved mechanical protection of the at least one associated magnetic flux guiding element. In addition, the unit consisting of the protective casing and at least one magnetic flux guiding element can be integrated in the base assembly in a simplified manner. In particular, this unit can be encased in concrete in a simple manner. The at least one associated magnetic flux guiding element is a ferrite body.

If at least one of the magnetic flux guiding elements is a ferrite concrete body, an associated protective jacket is advantageously and expediently omitted.

Embodiments are preferred in which at least one of the at least one protective jacket is made of a soft plastic. In particular, the protective casing can be a plastic compound enclosing the at least one associated magnetic flux guiding element. In this way, a simplified production of the base assembly is achieved with at the same time increased mechanical protection of the at least one associated magnetic flux guiding element.

Alternatively, the protective jacket can also be designed as a loose, unbound grain structure, which is introduced in a compacted form so that it cannot be further compacted, or only minimally, and thus permanently fills the cavity between the concrete block and the magnetic flux guiding element in a volume-neutral manner.

In preferred embodiments, the grain framework comprises grains of a solid material, preferably consists of such grains. The material is advantageously stone, glass, ceramics and the like.

Most preferably, the grains are largely spherical. The grain size is advantageously small in relation to the minimum thickness of the associated cavity. In particular, the grain size is at most 0.2 times the minimum thickness of the cavity, the grain sizes preferably being largely constant, ie the grain structure being largely equigranular.

It is also preferred if the grain structure has a low to very low flow index, in particular with an ff _c value of less than 15, preferably less than 12, particularly preferably less than <10, so that the volume changes with uneven deformation of the concrete block compared to the Magnetic flux guiding element can simply redistribute in the cavity and thus mechanically protects the magnetic flux guiding element. The magnetic flux element is thus “floating” in this grain structure.

Improved mechanical stability and/or increased resilience of the base assembly and improved mechanical protection of the coil and the magnetic flux guiding unit can be achieved by embedding at least one reinforcement in the concrete block.

Embodiments are considered to be preferred in which a textile reinforcement is embedded in the concrete block between the coil and the upper side. The textile test is advantageously one that is electromagnetically neutral. The textile reinforcement preferably extends transversely to the spacing direction.

It goes without saying that, in addition to the floor assembly, the arrangement with the floor assembly and the roadway also belongs to the scope of this invention.

The floor assembly is advantageously embedded in the roadway. So the road shows for the base assembly has a recess in which the base assembly is located.

In this case, the floor assembly preferably closes flush with the roadway. Thus, the floor assembly can be run over by a motor vehicle without any noticeable resistance from a vehicle driver. In addition, as explained above, there is increased efficiency when inductively charging a motor vehicle to be charged.

The floor assembly is expediently designed to be abrasion-resistant and weather-resistant on its side facing the motor vehicle.

For this purpose, the top of the concrete block can be provided with an additional weather-resistant protective layer. This means that a weather-resistant protective layer can be applied to the top of the concrete block. The protective layer is expediently electromagnetically neutral. In this case, a thickness of the protective layer running in the spacing direction can be between 3 mm and 10 mm.

The protective layer is preferably asphalt or bitumen. Thus, the weather resistance and abrasion resistance is achieved in a simple and effective way.

Further important features and advantages of the invention result from the dependent claims, from the drawings and from the associated description of the figures with reference to the drawings.

It goes without saying that the features mentioned above and those still to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

Preferred exemplary embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, with the same reference numbers referring to identical or similar or functionally identical components.

• 1 eine stark vereinfachte Darstellung einer induktiven Ladevorrichtung,
• 2 einen Schnitt durch eine Anordnung mit einer Bodenbaugruppe der Ladevorrichtung,
• 3 den Schnitt aus 2 bei einem anderen Ausführungsbeispiel.

Show it, each schematically

• 1 a highly simplified representation of an inductive charging device,
• 2 a section through an arrangement with a base assembly of the loading device,
• 3 the cut out 2 in another embodiment.

A floor assembly 1, as for example in the 1 until 3 is shown comes in a in 1 charging device 2 shown as an example and greatly simplified for inductive charging of a motor vehicle 3 is used. For this purpose, the floor assembly 1 interacts with an associated assembly 4 of the motor vehicle 3 . The interaction takes place in particular through a coil 5 of the base assembly 1, which serves as the primary coil 5 of the charging device 2, and a secondary coil, not shown, of the assembly 4 of the motor vehicle 3. The motor vehicle 3 is located on a roadway 6 for inductive charging by means of the charging device 2. During operation, the coil 5 generates an electromagnetic alternating field (not shown), which is used in the assembly 4 for charging the motor vehicle 3 . The base assembly 1 also has a magnetic flux guiding unit 7 with at least one magnetic flux guiding element 8 . The magnetic flux guiding unit 7 guides the alternating field generated by the coil 5 in the direction of the motor vehicle 3 . In particular, the magnetic flux guiding unit 7 prevents the alternating field from being radiated into the side facing away from the motor vehicle 3 .

The floor assembly 1 also includes a concrete block 9. The concrete block 9 has an upper side 10 facing the motor vehicle 3 to be loaded and an underside 11 facing away from the upper side 10 and consequently the motor vehicle 3. In the exemplary embodiments shown, the concrete block 9 is cuboid, purely by way of example. In this case, the coil 5 and/or the magnetic flux guiding unit 7 are accommodated in the concrete block 9 . The magnetic flux guiding unit 7 and the coil 5 are spaced apart from the upper side 10 . In the exemplary embodiments shown and preferably, the coil 5 and the magnetic flux guiding unit 7 are accommodated in the concrete block 9 . In this case, the coil 5 is arranged in a distance direction 12 from the underside 11 to the upper side 10 on the side of the magnetic flux guiding unit 7 facing the upper side 10 . Thus, the spacing direction 12 also corresponds to the spacing direction 12 of the magnetic flux guiding unit 7 from the upper side 10 . The coil 5 is spaced apart from the magnetic flux guiding unit 7 in the spacing direction 12 . In the exemplary embodiments shown, the coil 5 and the magnetic flux guiding unit 7 are cast in the concrete block 9 or cast around by the concrete block 9 . The concrete block 9 is expediently electromagnetically neutral. The concrete block 9 is preferably made or formed from water-impermeable concrete 25, also called “WU concrete” 25 for short.

The floor assembly 1 and the roadway 6 are components of an arrangement 13. In the exemplary embodiments shown, the floor assembly 1 is embedded in the roadway 6. A recess 14 is provided in the roadway 6 for the floor assembly 1 to let the floor assembly 1 into the roadway 6 educated. The floor assembly 1, in particular the underside 11 of the concrete block 9, lies on a base 15 of the recess 14. In addition, in the exemplary embodiments shown and preferably, the floor assembly 1, in particular the upper side 10 of the concrete block 9, is flush with the roadway 6.

At the in the 1 and 2 Embodiments shown, the magnetic flux guide unit 7 includes a plurality of magnetic flux guide elements 8, wherein in the views of 1 and 2 Purely by way of example, four magnetic flux guiding elements 8 can be seen. The magnetic flux guiding elements 8 are here arranged in pairs at a distance from one another transversely to the spacing direction 12 . In the embodiments of 1 and 2 the respective magnetic flux guiding element 8 is designed as a ferrite body 16 purely by way of example.

This in 2 shown embodiment differs from that in 1 shown embodiment of the base assembly 1 characterized in that for at least one of the magnetic flux guiding elements 8 a protective jacket 17 for mechanical protection of the at least one associated magnetic flux guiding element 8 is provided. at in 2 A common protective jacket 17 is provided for each two of the magnetic flux guiding elements 8 shown. in the in 2 shown embodiment, the respective protective jacket 17 encapsulates the at least one associated magnetic flux guiding element 8 entirely. At the in 2 In the exemplary embodiments shown, the two associated magnetic flux guiding elements 8 are completely encapsulated by the common associated protective jacket 17 . To protect the at least one associated magnetic flux guiding element 8, the protective casing 17 is mechanically softer than the magnetic flux guiding element 8. In particular, at least one of the protective casing 17, advantageously the respective protective casing 17, is a soft plastic body 18. Alternatively, the protective casing 17 can also be used as a be formed loose grain structure 26, which is introduced in a compact form around the at least one associated magnetic flux guiding element 8. A thickness 24 of the protective casing 17 running in the spacing direction 12 is advantageously at least 2 mm on at least one side of the at least one associated magnetic flux guiding element 8 . In the exemplary embodiments shown and preferably, the thickness 24 of the respective protective jacket 17 is at least 2 mm both on the side facing away from the top side 10 and on the side facing away from the top side 10 and thus the bottom side 11 .

This in 2 shown embodiment differs from that in 1 shown embodiment further characterized in that a reinforcement 19 is embedded in the concrete block 9 between the top 10 of the concrete block 9 and the coil 5. The reinforcement 19 provides additional mechanical stabilization and thus an increased mechanical resilience of the floor assembly 1. The reinforcement 19 is expediently electromagnetically neutral. In particular, the reinforcement 19 is a textile reinforcement 20. In the exemplary embodiment shown, the reinforcement 19 extends flatly and advantageously transversely to the spacing direction 12.

This in 3 shown embodiment differs from that in 2 shown embodiment in that the magnetic flux guiding unit 7 has a single magnetic flux guiding element 8 . The magnetic flux guiding element 8 extends transversely to the spacing direction 12 , so to speak, over the entire extent of the coil 5 . at in 3 shown embodiment, the magnetic flux guiding element 8 is also a magnetizable concrete body 21. The in 3 shown embodiment differs from that in 2 shown embodiment further characterized in that no protective jacket 17 is provided for the magnet guide unit 7.

As in 2 and 3 shown, a waterproof and electromagnetically neutral coating 27 can completely enclose the concrete block 9 . The coating 27 can be formed, for example, from a paint or a hardening filler, which contains components made of plastic and/or bitumen. The thickness of the coating 27 is advantageously less than 10 mm, preferably less than 5 mm.

In order to improve resistance of the concrete block 9 and thus of the floor assembly to weathering and abrasion, as in 3 indicated, alternatively or additionally, a protective layer 22, preferably made of asphalt and/or bitumen, can be applied to the upper side 10 of the concrete block 9. The protective layer 22 advantageously has a small thickness 23 of a few millimeters, for example between 5 mm and 20 mm, running in the spacing direction 12 . Here the protective layer is 22 in 3 enlarged for better illustration. The protective layer 22 can, as in 3 shown in addition to the coating 27 applied in order to achieve improved mechanical protection of the concrete block 9 and in particular protection of the coating 27.

The base assembly 1 is able to absorb loads acting on the base assembly 1 by motor vehicles 3 and pass them on to the base 15 without damaging the coil 5 and the magnetic flux guiding unit 7 . Furthermore, the coil 5 is arranged closer to the charging motor vehicle 3, so that the motor vehicle 3 is charged with increased efficiency. Also the relative positioning of the coil 5 to the magnetic flux guiding unit 7 leads to an increased efficiency of the base assembly 1 and consequently of the loading device 2.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was 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.

Patent Literature Cited

• EP 3360143 A1 [0004]

Claims (14)

Base assembly (1) for an inductive charging device (2) for inductive charging of a motor vehicle (3) located above the base assembly (1), - with a concrete block (9), which has an upper side (10) facing the motor vehicle (3) to be loaded, - with a coil (5) and with a magnetic flux guiding unit (7) comprising at least one magnetic flux guiding element (8), - wherein the coil (5) and/or the magnetic flux guiding unit (7) are accommodated in the concrete block (9), - the coil (5) being arranged on the side of the magnetic flux guiding unit (7) facing the upper side (10), - wherein the coil (5) and the magnetic flux guiding unit (7) are arranged at a distance from the upper side (10), - wherein the coil (5) is spaced in a spacing direction (12) of the magnetic flux guiding unit (7) to the upper side (10) for the magnetic flux guiding unit (7). bottom assembly claim 1 , characterized in that the coil (5) and/or the magnetic flux guiding unit (7) are encapsulated by the concrete block (9). bottom assembly claim 1 or 2 , characterized in that at least one of the at least one magnetic flux guiding element (9) is a ferrite body (16). Floor assembly according to one of Claims 1 until 3 , characterized in that at least one of the at least one magnetic flux guiding element (8) is a magnetizable concrete body (21). Floor assembly according to one of Claims 1 until 4 , characterized in that - that at least one of the at least one magnetic flux guide elements (8) is accommodated in the concrete block (9), - that at least one of the at least one magnetic flux guide elements (8) accommodated in the concrete block (9) in a space between the magnetic flux guide element (8) and the Concrete block (9) arranged protective jacket (17) is added, - that the protective jacket (17) is mechanically softer than the magnetic flux guiding element (8). bottom assembly claim 5 , characterized in that at least one of the at least one protective jacket (17) is made of a soft plastic. bottom assembly claim 5 or 6 , characterized in that at least one of the at least one protective jacket (17) is designed as a loose, unbound grain framework (26). bottom assembly claim 7 , characterized in that the grain structure (26) is designed in such a way that it supports the at least one associated magnetic flux guiding element (8) in the concrete block (9) in a floating manner. Floor assembly according to one of Claims 5 until 8th , characterized in that at least one of the at least one magnetic flux guiding elements (8) is completely encapsulated in the protective casing (17). Floor assembly according to one of Claims 1 until 9 , characterized in that the concrete block (9) is at least partly made as a so-called water-impermeable concrete (25). Floor assembly according to one of Claims 1 until 10 , characterized in that a reinforcement (19) is embedded in the concrete block (9) between the coil (5) and the top (10). Floor assembly according to one of Claims 1 until 11 , characterized in that the floor assembly (1) has a water-impermeable, electromagnetically neutral coating (27) which completely encloses the concrete block (9). Floor assembly according to one of Claims 1 until 12 , characterized in that on the top (10) of the concrete block (9) a weather-resistant protective layer (22) is applied. Arrangement (13) with a roadway (6) for motor vehicles (3) and a floor assembly (1) according to one of Claims 1 until 13 , wherein a depression (14) is formed in the roadway (6), in which the floor assembly (1) is arranged, so that the floor assembly (1) is flush with the roadway (6).

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