Stationary bottom assembly for inductive charging device

Abstract

The present invention relates to a stationary bottom assembly (1) for an inductive charging device (2), comprising: a housing (3) having a base plate (4) and a housing cover (5) covering the base plate (4); At least one flat coil (8) held by a litz wire support (7), the flat coil (8) being spaced apart in a spacing direction (6) relative to the base plate (4); A core assembly (10) having at least one core body (11) for guiding magnetic flux; Equipped with A hollow chamber (12) is formed between the at least one core body (11) and the base plate (4), At least one support (15) is provided between the flat coil (8) and the base plate (4) in the separation direction (6), the support (15) extending through the cavity (12); The litz wire support (7) has a pressure seat (16), A load distribution structure (17) is disposed between the housing cover (5) and the litz wire support (7), and the load distribution structure (17) is supported on a pressure base (16) and is supported via the pressure base (16) on a corresponding support (15). Regarding the stationary bottom assembly.

Description

[Technical field]

[0001] The present invention relates to a stationary bottom assembly for an inductive charging device for inductive charging of automobiles.

[0002] In at least partially electrically driven motor vehicles, regular charging of the motor vehicle's electrical energy storage device is necessary. For this purpose, in principle, a direct electrical connection between the motor vehicle and an external source of electrical energy, for example a current terminal, can be established. However, this requires manual action by the user.

[0003] It is further known to charge motor vehicles, and in particular electric energy storage devices, by induction: a primary coil is located in a stationary bottom assembly ("ground assembly") outside the vehicle, which cooperates by induction with a secondary coil ("vehicle assembly") inside the vehicle to charge the energy storage device.

[0004] During operation of the charging device, the vehicle being charged may pass above the bottom assembly, which may lead to damage to the bottom assembly, at least in the long term, if the load-bearing capacity is too low.

[0005] The present invention therefore addresses the problem of providing an improved or at least alternative embodiment of a stationary bottom assembly of the type mentioned at the beginning, which has in particular a relatively high load capacity.

[0006] The above object is achieved according to the invention by the subject matter of the independent claim 1. Advantageous embodiments are the subject matter of the respective dependent claims.

[0007] The invention is based on the general idea of ​​increasing the mechanical load-bearing capacity of a stationary bottom assembly (ground assembly) for an inductive charging device by means of a special pressure seat on the litz wire support, which holds the helically wound conductor of the flat coil. In this case, a stationary bottom assembly according to the invention for an inductive charging device for inductive charging of a motor vehicle parked on the ground comprises a housing with a base plate extending in a plate-like manner transverse to the separation direction and a housing cover covering said base plate. A mounting chamber is provided in the housing, in which at least one flat coil with the above-mentioned helically wound conductor is arranged, held by the litz wire support. In this case, the litz wire support and the flat coil are arranged in the separation direction between the base plate and the housing cover. Furthermore, a core assembly with at least one core body, for example a ferrite plate, for guiding the magnetic flux is provided, which is arranged in the separation direction between the base plate and the flat coil and extends in a plate-like manner transverse to the separation direction. In this case, a cavity is arranged between at least one core body, e.g. a ferrite plate, and a base plate, through which a support extends in the direction away from the core body, the support being supported on the base plate at its bottom side and supporting a flat coil with a wound conductor and a litz wire support, the litz wire support itself having a pressure seat, via which a load distribution structure, e.g. a load plate, arranged between the housing cover and the litz wire support, is supported directly or indirectly on a corresponding support.Due to the pressure pedestals, which are preferably arranged at least approximately, or in particular completely, flush in the direction of separation with respect to the planar cross-sectional dimensions relative to the respective underlying supports, the load pattern on the components at risk, the litz wire support or the flat coil and the core assembly, is approximately uniaxial pressure normal stress, so that an improved removal of the load of the vehicle traveling on the housing cover can be achieved, which also significantly reduces the risk of failure of the above-mentioned parts and other load-transmitting components. In this case, the load distribution structure is preferably designed in such a way that it allows support on the base plate exclusively via the pressure pedestals or other supports in all possible operating states. That is to say, even in the case of deflection of the load distribution structure, no contact occurs between the load distribution structure and the litz wire support outside the pressure pedestal or pressure pedestals, so that there is no risk of damage to the litz wire support or the flat coil or the core assembly arranged below it, even when the vehicle passes over the stationary bottom assembly. Here, the pressure pedestals face the load distribution structure. In this case, typically, a number of such pressure seats are provided, each corresponding to a support arranged below in the spacing direction, so that a tight support of the load distribution structure and thus a small deflection of the load distribution structure can be achieved.

[0008] In an advantageous development of the stationary bottom assembly according to the invention, the litz wire supports are supported directly on the corresponding supports via spacer plates. This offers the great advantage that the core assembly and its core body remain unloaded, independent of the respective load of the vehicle traveling above the stationary bottom assembly. In this case, the core body is located at a distance from each support in a transverse direction to the spacing direction, where the supports are arranged in the central region of the flat coil in a transverse direction to the spacing direction, so that they do not or only slightly disturb the magnetic field generated by the flat coil. Furthermore, in such an arrangement, it is also possible to form the respective supports at least partially from metal, which makes it possible to achieve a high support capacity and a high thermal conductivity and thus improved cooling of the flat coil.

[0009] Alternatively, of course, the litz wire support can also be supported on a corresponding support via a spacer plate and a core body, in which case the support can also be at least partially manufactured from metal in this embodiment, since the core body shields the support from the magnetic field.

[0010] In another advantageous embodiment, the litz wire support has a support base, via which the litz wire support is supported on the spacer plate. In this case, the litz wire support can be designed open from below and has a receiving section, into which the respective conductor of the flat coil is inserted, for example by clipping. In this case, a uniform support of the litz wire support on the spacer plate is possible via the supporting section, and as the number of supporting sections increases, a lower surface pressure can be achieved. In this case, the litz wire support can have a lattice structure, which allows it to be designed relatively rigid in itself.

[0011] Advantageously, at least one pressure seat is formed integrally with the litz wire support. This has the great advantage that the respective pressure seat and the litz wire support can be formed, for example, as an integral plastic injection-molded part, and thus can be manufactured at low cost and with high quality. Alternatively, of course, at least one pressure seat can be formed separately from the litz wire support and configured to be, for example, clipped or screwed to the litz wire support by a form connection and / or to be, for example, glued or welded to the litz wire support by a material connection. In this case, the pressure seat can therefore also be formed from a material different from the litz wire support. In this case, such a pressure seat formed separately from the litz wire support can be supported on the litz wire support or can be through-engaged with the litz wire support, which allows a direct support of the load distribution structure via the pressure seat and the spacer plate or, if appropriate, the core body on the support.

[0012] In another advantageous embodiment, the pressure seat is made of plastic, in particular of Shore A and / or E of ≧50. D It is made of an elastomer having an elastic modulus of ≦5000 MPa. Such a plastic allows a relatively uniform pressure distribution over the seating surface of the pressure seat and thus a relatively uniform load introduction either to the spacer plate or to the litz wire support. Alternatively, the pressure seat can of course also be made of ceramic. What is important here is only that the pressure seat or the litz wire support be made of a material that has no or only a very small effect on the power transfer of the alternating electromagnetic field generated by the flat coil or core assembly.

[0013] In a further advantageous embodiment of the solution according to the invention, the load distribution structure is made of plastic, in particular E LIt is formed as a plate having an elastic modulus of ≧10 GPa. As materials, in particular plastics come into consideration here, in particular polyamide (PA), polyoxymethylene (POM), polyphenylene sulfide (PPS), polyether ether ketone (PEEK).

[0014] Advantageously, the load distribution structure is formed as a plate made of fiber-reinforced plastic, in particular glass-fiber-reinforced plastic. Here, in particular glass-fiber-reinforced plastic has a significantly higher strength and a significantly higher modulus of elasticity. For example, short fibers, long fibers, but also endless fibers can be used here. Furthermore, glass fibers offer the great advantage of not affecting alternating electromagnetic fields.

[0015] In another advantageous embodiment of the solution according to the invention, an air channel passes through the cavity, so that, for example, electronic components arranged in the cavity can be cooled by air flow. The supports supporting the core assembly or the Litz wire support and the load distribution structure are also located in the cavity, so that cooling of the flat coil can also be achieved indirectly via cooling of the supports. Here, the core body of the core assembly is arranged in the cavity and in the air channel and can likewise be cooled, for example, by cooling air flowing therethrough. Such a cooling section increases the performance of the stationary bottom assembly. Further improvements are possible, for example, by providing cooling passages for the cooling medium in the base plate, so that the base plate and thus the cavity and supports located above it can be actively cooled.

[0016] In a particularly advantageous embodiment of the solution according to the invention, the housing cover is supported on the base plate via a housing support, which in this case encloses a cavity and can additionally be used for load relief, the main load relief when a vehicle passes over the stationary bottom assembly according to the invention being carried out via a load distribution structure, for example a pressure pedestal and a support.

[0017] The load distribution structure can be placed, for example, on a support of the housing support and can thus be held by the housing support by a form-fitting connection. Additionally or alternatively, the load distribution structure can be connected to the at least one housing support, for example by gluing, welding or screwing. This allows the load distribution structure to be relatively easily removed while simultaneously removing the housing cover from the base plate. Additionally, the load distribution structure can be, for example, welded, glued or screwed to the underside of the housing cover.

[0018] Advantageously, at least one further support is provided for supporting the load distribution structure directly on the base plate, thereby allowing support outside the pressure seat without loading the core assembly or flat coils.

[0019] Important further features and advantages of the invention are evident from the respective dependent claims, the drawings and the corresponding figure description based on the drawings.

[0020] It is understood that the features mentioned above and further described below can be used not only in the respective combinations described, but also in other combinations or alone, without departing from the scope of the invention. The above-mentioned and further described components of a higher-level unit, e.g. an apparatus, device or assembly, shown separately, may form separate parts or components of said unit, even if shown differently in the figures, or may be integrated regions or sections of said unit.

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention are illustrated in the drawings and explained in detail in the following description, where like reference numbers refer to identical or similar or functionally identical components. [Brief description of the drawings]

[0022] [Figure 1] FIG. 2 is a cross-sectional view showing a first possible embodiment of a stationary bottom assembly according to the present invention. [Diagram 2] FIG. 2 is a view similar to FIG. 1 but showing an alternative embodiment. [Diagram 3] FIG. 13 is a cross-sectional view showing details of a pressure platform formed integrally with a litz wire support. [Figure 4] FIG. 4 is a view similar to FIG. 3 but showing a separately formed pressure pedestal. [Diagram 5] FIG. 5 is a view similar to FIG. 4 but showing a continuous pressure pedestal. [Figure 6] FIG. 1 shows a view from below of the litz wire support with the inserted flat coil. [Figure 7] FIG. 1 is a top view of a portion of a litz wire support having a flat coil. [Figure 8] This is a view similar to FIG. 7 but seen obliquely from below.

[0023] 1 and 2, a stationary bottom assembly 1 according to the invention for an inductive charging device 2 for inductive charging of a motor vehicle, not shown in detail, comprises a housing 3 with a base plate 4 and a housing cover 5 covering said base plate 4. In this case, the base plate 4 extends transversely to a spacing direction 6 which generally corresponds substantially to the vertical direction. Furthermore, at least one flat coil 8 is provided, held by a Litz wire support 7, which has a helically wound conductor 9 and is spaced apart from the base plate 4 in the spacing direction 6, i.e. arranged so as to lie on the base plate 4. Furthermore, a core assembly 10 is provided with at least one core body 11 for guiding magnetic flux, e.g. a ferrite plate, which is spaced apart from the base plate 4 and the flat coil 8 in the spacing direction 6, i.e. arranged between the base plate 4 and the conductor 9 of the flat coil 8, and extends transversely to the spacing direction 6. In this case, a cavity 12 is formed between at least one core body 11, for example a ferrite body, and the base plate 4, through which an air channel 13, for example, through which cooling air 14 can flow, is led. In the cavity 12, at least one electronic component 20 can furthermore be arranged, which can be additionally cooled by the cooling air 14 flowing in the air channel 13.

[0024] In this case, at least one support 15 is provided between the flat coil 8 and the base plate 4, which extends through the cavity 12 in the spacing direction 6. The litz wire support 7 furthermore has at least one pressure seat 16, in which a load distribution structure 17, for example a load distribution plate, is arranged between the housing cover 5 and the litz wire support 7, which is supported on and via the at least one pressure seat 16 on a corresponding support 15 arranged below it in the spacing direction 6.

[0025] In this case, the stationary bottom assembly 1 according to the invention offers the great advantage that, when a load acts from above, for example by a car passing over the stationary bottom assembly 1, the load introduction takes place exclusively via the pressure pedestals 16 above the litz wire support 7 or the supports 15 arranged below it, and even if this flexes, a direct load introduction from the load distribution structure 17 to the flat coils 8 is reliably avoided, thus avoiding in particular damage. In this case, as can be seen from Figures 1 and 2, a number of such pressure pedestals 16 with supports 15 arranged below in the distance direction 6 are provided, which allows a relatively uniform support of the load distribution structure 17 and also allows for a slight bending of the load distribution structure 17.

[0026] 2, the load distribution structure 17 may be supported directly above the base plate 4 via a further support 18. When such an additional support 18 is used, the pressure pedestal 16 and the support 15 can generally be made relatively small and particularly slim.

[0027] Returning to figure 1, it can be seen that the litz wire supports 7 are supported on the corresponding supports 15 via the spacer plates 19 and the core body 11, whereas according to figure 2 the litz wire supports 7 are supported directly on the corresponding supports 15 via the spacer plates 19. The advantage of the embodiment shown in figure 2 is that in particular the core body 11 of the core assembly 10 is not loaded, in particular independently of loads acting from above.

[0028] The housing cover 5 has a lateral inclined portion 21 as well as a housing support 22, via which the housing cover 5 is supported on the base plate 4. Furthermore, the housing support 22 can have a support portion 23 (see FIG. 1 ), by means of which the load distribution structure 17, for example a load distribution plate, can be held in a form-locking manner between the housing cover 5 and the support portion 23. At least a small load support of the load distribution structure 17 is thus also possible on the base plate 4 via the support portion 23 and the housing support 22.

[0029] The load distribution structure 17 can in this case be firmly connected, for example by gluing, welding or screwing, to the at least one housing support 22, the support 23 and / or the housing cover 5. This allows, in particular, the removal of the load distribution structure 17 and the removal of the housing cover 5 to be carried out simultaneously and in a combined manner.

[0030] If we take a closer look at the pressure base 16 according to figures 3 to 5, various embodiments can be seen here. According to figure 3, for example, a litz wire support 7 is shown which is formed integrally with the pressure base 16, in which case the pressure base 16 and the litz wire support 7 are formed integrally.

[0031] 4, the pressure seat 16 is formed separately from the litz wire support 7 and is only positively held in the recess of the litz wire support 7. Of course, in addition to a purely positively held hold, a bonding of the pressure seat 16 to the litz wire support 7 is also possible here.

[0032] According to Fig. 5, the pressure seat 16 is likewise formed separately from the litz wire support 7, but passes completely through said litz wire support 7, so that a direct load transfer from the load distribution structure 17 takes place via the pressure seat 16 into the spacer plate 19 and from there to the core body 11 according to Fig. 1 and further into the support 15, or directly into the support 15 according to Fig. 2. In the embodiment shown in Fig. 5 too, the pressure seat 16 can be connected to the litz wire support 7 not only by a form-fitting connection, but also, for example, by a material connection, for example by gluing or screwing.

[0033] In this case, the pressure seat 16 or also the litz wire support 7 is preferably made of plastic, for example with a Shore A hardness of ≧50 and / or E D It is made of an elastomer having an elastic modulus of ≦5000 MPa. Plastics such as, for example, EPDM (Ethylene Propylene Diene (Monomer) Rubber) or polypropylene (PP) come into consideration as materials here. The load distribution structure 17 should furthermore be very stiff and have a high strength, so that even if an upward passage of the load distribution structure 17 between the two supports 15 takes place, the deflection of the load distribution structure 17 is limited and no contact occurs between the load distribution structure 17 and the litz wire support 7. To further increase the strength and stiffness of the load distribution structure 17, the load distribution structure 17 may be fiber-reinforced, in particular glass-fiber-reinforced. Purely theoretically, other fibers, for example aramid fibers, are of course also conceivable.

[0034] When observing the litz wire support 7 corresponding to Figures 6 to 8, it can be seen that the litz wire support 7 has a support base 24, and the litz wire support 7 is supported on the spacer plate 19 via the support base 24, and further on the core body 11 via the spacer plate 19, or directly on the support 15. At this time, the support base 24 has a housing portion 25 in which each conductor 9 of the flat coil 8 is guided, as seen from below. In the assembled state, as shown in, for example, Figure 8, the pressure base 16 (upper surface of Figure 8) supports the load distribution structure 17 and presses it downward (see Figure 6) against the spacer plate 19. The spacer plate 19 is bonded to the core body 11 (ferrite plate) located on the support 15.

[0035] In conclusion, the stationary bottom assembly 1 according to the invention allows a significant increase in the load-bearing capacity of the bottom assembly 1, whereby the load distribution structure 17 and the pressure pedestal 16 in particular ensure that direct loads on the flat coil 8 and thus possible damage to said coil 8 or to the core assembly 10 arranged below are avoided. A further advantage of such an arrangement is obtained by the fact that the pressure pedestal 16 and the support 15 are aligned substantially flush in the separation direction 6, which also concerns in particular the planar cross-sectional dimensions of the pressure pedestal 16 and the support 15 located below it. Furthermore, the pressure pedestal 16 and the corresponding support 15, which are flush with it in the axial direction in the separation direction 6, preferably have at least approximately, and preferably completely, identical cross-sections in terms of size, shape and orientation. This results in the loads in the components particularly at risk, i.e. the litz wire support 7 or the flat coil 8 and the core assembly 10 or core body 11, occurring approximately uniaxially as pressure normal stresses in the spacing direction 6, which significantly reduces the risk of failure in these and other load-transmitting components.

[0036] Due to the condition that both the litz wire support 7 and each pressure seat 16 and the load distribution structure 17 and the housing cover 5 are made from an electromagnetically neutral material, for example plastic or ceramic, the power transmission of the alternating electromagnetic field formed by the flat coil 8 and the corresponding core body 11 is not or only slightly impaired.

Claims

1. A stationary bottom assembly (1) for an inductive charging device (2) for inductive charging of a motor vehicle, comprising: a housing (3) having a base plate (4) extending like a plate in a direction transverse to the separation direction (6) and a housing cover (5) covering the base plate (4); at least one flat coil (8) held by a litz wire support (7), the flat coil (8) having a helically wound conductor (9) and spaced apart from the base plate (4) in a spacing direction (6); a core assembly (10) having at least one core body (11) for guiding magnetic flux, the core body (11) being disposed between the base plate (4) and the conductor (9) in the separation direction (6) and extending in a plate-like manner in a direction transverse to the separation direction (6); Equipped with A hollow space (12) is formed between the at least one core body (11) and the base plate (4), At least one support (15) is provided between the flat coil (8) and the base plate (4) and extends through the cavity (12) in the separation direction (6), The litz wire support (7) has a pressure seat (16), A load distribution structure (17) is disposed between the housing cover (5) and the litz wire support (7), and the load distribution structure (17) is supported on the pressure base (16) and is supported on the corresponding support (15) via the pressure base (16). Stationary bottom assembly (1).

2. the at least one pressure seat (16) is arranged so as to be at least approximately, preferably completely, flush with the corresponding support (15) in the axial direction in the separation direction (6); the pressure seat (16) and the corresponding support (15) which is coplanar with the pressure seat (16) in the axial direction in the separation direction (6) have at least approximately, preferably completely, identical cross sections in terms of size, shape and orientation; The stationary bottom assembly of claim 1 .

3. The litz wire supports (7) are supported directly on the corresponding supports (15) via spacer plates (19), or The litz wire support (7) is supported on a corresponding support (15) via a spacer plate (19) and a core body (11).

3. The stationary bottom assembly according to claim 1 or 2.

4. At least one further support (18) is provided to support the load distribution structure (17) directly on the base plate (4).

3. The stationary bottom assembly according to claim 1 or 2.

5. the pressure seat (16) is integrally formed with the litz wire support (7), or the pressure seat (16) is formed separately from the litz wire support (7) and is clipped or screwed to the litz wire support (7), in particular by a form-fitting connection, and / or is glued or welded to the litz wire support (7), in particular by a material-fitting connection; 3. The stationary bottom assembly according to claim 1 or 2.

6. 6. A stationary bottom assembly according to claim 5, wherein said pressure seat (16) is fully through-engaged with said litz wire support (7).

7. The pressure seat (16) is made of plastic, in particular of a Shore A hardness of ≥ 50 and / or E Ｄ 3. The stationary bottom assembly of claim 1, wherein the bottom assembly is made of an elastomer having a modulus of elasticity of ≦5000 MPa.

8. The load distribution structure (17) is particularly Ｌ 3. The stationary bottom assembly according to claim 1, wherein the bottom assembly is formed as a plate made of plastic having an elastic modulus of ≥ 10 GPa.

9. 3. Stationary bottom assembly according to claim 1 or 2, characterized in that the load distribution structure (17) is formed as a plate made of fiber-reinforced plastic, in particular glass-fiber-reinforced plastic.

10. an air flow path (13) for cooling air (14) is guided through said cavity (12); and / or At least one electronic component (20) is disposed within the cavity (12).

3. The stationary bottom assembly according to claim 1 or 2.

11. 3. The stationary bottom assembly according to claim 1, wherein the housing cover (5) is supported on the base plate (4) via a housing support (22).

12. 12. The stationary bottom assembly of claim 11, wherein the load distribution structure (17) rests on a support (23) of the housing support (22).

13. 12. Stationary bottom assembly according to claim 11, wherein the load distribution structure (17) is connected to at least one housing support (22), in particular by gluing, welding or screwing.

14. 3. Stationary bottom assembly according to claim 1 or 2, characterized in that the load distribution structure (17) is connected to the housing cover (5), in particular by gluing, welding or screwing.

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