Electrical heating device, in particular for mobile applications

Abstract

The invention relates to an electrical heating device, in particular for mobile applications, comprising a substrate and a heating conductor layer (12) which is formed on the substrate, wherein the heating conductor layer (12) is interrupted by at least one first isolating interruption (13), wherein the first isolating interruption (13) isolates at least a first layer section (15) and a second layer section (16) of the heating conductor layer (12) from one another, wherein the first layer section (15), at a first end (28), is connected to a first connection (29), for example positive pole, and the second layer section (16), at a first end (34), is connected to a second connection (35), for example negative pole, wherein the first layer section (15), at a second end (31), is connected to the second layer section (16) and, via this second layer section (16), is connected to the second connection (35).

Description

[0001] The invention relates to an electric heating device for mobile applications according to claim 1 and to a vehicle, in particular a motor vehicle, comprising an electric heating device.

[0002] WO 2013 / 186106 A1 describes an electric heating device for a motor vehicle with a heating resistor formed as a conductor track on a substrate. The conductor track is bifilar in design, and a widened insulation region is provided in the area of a conductor track deflection in the opposite direction. The widened insulation region is intended to ensure that a current flow is established across the entire width of the conductor track, if possible, in order to prevent the formation of particularly well-permeable areas on the inside and poorly permeable areas on the outside edge of the conductor track. In this context, however, it has been found that a comparatively significantly elevated temperature can still occur in the area of the conductor track deflection. EP 2 779 784 A1 discloses an electric heating device in which a continuous heating conductor track made of a heating conductor material is thicker in deflection areas.WO 2008 / 011507 A1 discloses an electric heating device in which a continuous heating conductor track comprises an additional metal layer in the deflection area. US 2,878,357 A describes an electric window heater in which transparent heating conductor track sections are fitted between two glass substrate panes, the narrow end faces of which abut against metallic connecting or connection structures. DE 20 2018 102 013 U1 also discloses a generic electric heating device.

[0003] It is an object of the present invention to propose an electric heating device and a corresponding vehicle, in particular a motor vehicle, in which a comparatively homogeneous temperature distribution is achieved, wherein the electric heating device should be as compact and cost-effective as possible to manufacture.

[0004] This object is achieved by an electric heating device, in particular for mobile applications, according to claim 1.

[0005] In particular, the object is achieved by an electrical heating device having a substrate made of a metal and a heating conductor layer formed on the substrate, which is separated from the substrate by an intermediate electrically insulating intermediate layer, wherein the heating conductor layer is interrupted by at least one first separation interruption, wherein the first separation interruption separates at least a first and a second layer section of the heating conductor layer from one another, wherein the first layer section is connected to a first terminal at a first end and the second layer section is connected to a second terminal at a first end, wherein the first layer section is connected to the second layer section at a second end and is connected to the second terminal via this second layer section, wherein the first and second terminals are at least partially assigned a separate connection strip,wherein at least one connection break of the separate connection strip merges into the at least one break and / or is aligned with it and / or is arranged on the same line as it.

[0006] A core concept of the invention is to separate at least two layer sections of a heating conductor layer from one another by a (first) separation interruption and to interconnect or electrically connect (contact) them accordingly in such a way that a current flows through the at least two layer sections (in particular in series) and heating can take place. The manufacturing and, in particular, structuring expenditure can be comparatively low. The temperature (during operation) in the region of deflections can be comparatively moderate or not significantly higher (compared to other regions). Overall, an effective and reliable heating device is achieved in a simple manner.

[0007] A disconnection is understood, in particular, as an interruption that prevents or at least reduces the flow of current (directly or via the disconnection) between corresponding, mutually separated areas or sections. For this purpose, the disconnection is preferably designed to be insulating or has a correspondingly high resistance.

[0008] An electrical conductivity of the (respective) separation interruption is preferably less than 10 6< S·m -1< , more preferably less than 10 3< S·m -1< , more preferably less than 10 -1< S·m -1< , more preferably less than 10 -4< S·m -1< , more preferably less than 10 -6< S·m -1< (at 20 °C).

[0009] Alternatively or additionally, an electrical conductivity of the (respective) separation interruption is preferably lower than an electrical conductivity of the respective separated sections, in particular multiplied by a factor of 0.5; preferably multiplied by a factor of 0.1, further preferably multiplied by a factor of 0.05 (at 20 °C).

[0010] Alternatively or additionally, an electrical conductivity of the (respective) separation interruption is preferably lower than an electrical conductivity of a / the electrical connecting section, in particular connecting strip, e.g. copper strip, in particular multiplied by the factor 0.5; preferably multiplied by the factor 0.1, further preferably multiplied by the factor 0.05 (at 20 °C).

[0011] Preferably, the heating conductor layer is interrupted (in particular completely) by at least one second separation interruption, wherein the second separation interruption separates at least a third of at least one second layer section of the heating conductor layer. Further preferably, the third section is connected at a first end to the first terminal or pole, for example, the positive pole (electrically conductive). Overall, this allows for a particularly effective yet simple structuring.

[0012] The third layer section is preferably connected to the second terminal (only) via the second layer section.

[0013] Where connections are mentioned in this document, this always refers to electrically conductive connections, unless the context indicates otherwise.

[0014] In a specific embodiment, there are exactly two separation interruptions, but there may also be at least three or at least four separation interruptions. In this respect, the heating conductor layer can be divided into exactly two or three, but possibly also into more than three, in particular into more than four or more than five layer sections (by corresponding separation interruptions).

[0015] According to the embodiment, the first and second layer sections are (at least partially) (conductively) connected to one another by an additional or separate conductor, in particular a wire and / or a conductive (unstructured according to the embodiment) strip (metal or connecting strip), wherein the strip can alternatively also be structured. A separate conductor is to be understood in particular as a conductor which is structurally separated from the heating conductor layer, in particular is (additionally) attached on and / or to the heating conductor layer and / or has an increased (or reduced) thickness compared to the heating conductor layer. A metal strip is particularly preferred, more preferably a copper strip (i.e. a metal strip made of copper or a copper alloy). The separate conductor (in particular a strip) can extend over at least 50%, if necessary.extend over at least 80% or (at least almost) 100% of one side of the (entire) heating conductor layer (or even beyond this side). A width of the separate conductor (in particular strip) preferably corresponds to a maximum of 50%, more preferably a maximum of 10%, of an extension of the heating conductor layer in the direction of the width of the separate conductor (strip). In specific embodiments, the separate conductor (in particular strip) is at least 3 times, preferably at least 5 times as long as it is wide. The separate conductor (in particular strip) can have (at least substantially) a rectangular contour and / or two (in particular parallel) long sides that extend over at least 50% of the total length of the strip.

[0016] In embodiments, a (separate) connection strip, in particular a (second) wire and / or a (second) conductive strip, in particular a common strip and / or a strip divided into at least two separate strip sections by at least one connection separation interruption, is assigned (at least partially) to the first and second connection or pole.

[0017] In embodiments, the separate terminal strip may have a contour line like the separate connecting strip. Preferably, the separate terminal strip differs from the separate connecting strip (at least or even only) in that the separate terminal strip comprises at least one terminal separation break (dividing it into at least two electrically separated strip sections).

[0018] The separate connecting strip can (apart from the connection interruption(s)) have a geometry or structure as described with regard to the separate connecting strip (even if the separate connecting strip is not designed according to such a geometry or has an alternative geometry). Regarding the material selection, reference is also made to the separate connecting strip (even if it does not have the above, optionally suggested material selection). Overall, the separate connecting strip enables a simple connection for the individual layer sections.

[0019] In a preferred embodiment, the first and second terminals (poles) are arranged on the same side of the heating conductor layer. A side of the heating conductor layer is understood to mean, in particular, an edge side (i.e., not a top or bottom side, but rather an edge side in a top view). The edge side can be one (or possibly two) shorter sides (alternatively, one of possibly two longer sides).

[0020] In a specific embodiment, the separate terminal strips and connecting strips can be arranged on opposite sides (in the sense of the previous paragraph).

[0021] According to the embodiment, at least one separation interruption runs at least substantially straight. An at least substantially straight course is to be understood in particular as meaning that the separation interruption runs either in the same direction over its entire length or, if appropriate, in (at least slightly) different directions, although preferably a maximum deviation (among all pairs of local directions) is not greater than 45°, preferably not greater than 20°, and more preferably not greater than 10°. In particular, a direction of the separation interruption (with regard to its course) should not be 180° at any point compared to at least one other point (or the direction there). This allows for simple structuring.

[0022] In preferred embodiments, the heating conductor layer and / or the first and / or second and / or third layer sections are / are at least substantially rectangular. Alternative geometries are conceivable (e.g., circular, elliptical, or generally polygonal).

[0023] Preferably, the heating conductor layer covers at least 80% of a substrate surface, more preferably at least 85% of the substrate surface. In this case, a comparatively good utilization of the available substrate surface is achieved while still allowing sufficient separation of the individual track sections from one another. The heating conductor layer can, in particular, cover less than 95% of the substrate surface.

[0024] An electrically insulating material can be arranged in the isolating gaps. Alternatively or additionally, the isolating gaps can also be formed by (for example, gap-like) free spaces.

[0025] At least one further layer, in particular an insulating layer, can be formed on the heating conductor layer.

[0026] In embodiments, the second layer section is wider than the first and / or third layer section, preferably at least 1.2 times as wide, more preferably at least 1.5 times as wide. This is particularly advantageous when the second layer section is formed as a common conductive layer section for two heating circuits (e.g., separated from one another in a first layer section and a third layer section).

[0027] At least two of the present (in particular the first and the second), possibly all of the present (in particular the first, second, and third), layer sections can be arranged in one plane, in particular on a common planar surface. Alternatively or additionally, at least two of the present (in particular the first and the second), possibly all of the present (in particular the first, second, and third), layer sections can be arranged not in one plane, for example on a non-planar surface and / or in different planes (for example, if four or six layer sections are provided, of which two or three each are arranged on different planes, in particular on different substrates).

[0028] In general, two or more heating circuits are preferably formed. The individual heating circuits should preferably be distinguished in that they have at least one layer section (for example a first layer section) which is not assigned to at least one other heating circuit. However, this should not preclude the possibility of a further layer section (for example the second layer section) being contained jointly in two heating circuits. In a specific embodiment, the electrical heating device comprises at least two heating circuits, wherein the first layer section is assigned only to the first heating circuit, the third layer section is assigned only to the second heating circuit, and the second layer section is assigned to both heating circuits. A heating circuit is to be understood in particular as an electrical circuit which extends from a first connection (pole) to a second connection (pole).

[0029] At least one separation interruption preferably runs through the heating conductor layer from a first to a second side (edge side) thereof, in particular completely. The sides (edge sides) are preferably opposite (edge) sides.

[0030] In a specific embodiment, the electric heating device is a motor vehicle heating device.

[0031] The above-mentioned object is further achieved in particular by a vehicle, in particular a motor vehicle, comprising an electric heating device of the above type.

[0032] The above-mentioned object is further achieved in particular by a method for producing the above electric heating device.

[0033] Preferably, at least one separation interruption is created by laser structuring. Alternatively or additionally, at least one separation interruption can be created by masking at least one masking section (during the application of the heating layer).

[0034] In a specific embodiment of the method, at least one separation interruption can be produced alternatively or additionally by an elongated body, in particular wire, which is introduced during production (and later removed again).

[0035] In general, the heating layer can be applied by thermal spraying.

[0036] For electrical contacting, at least one contact pad, in particular comprising copper, can be provided, for example, one contact pad per layer section. A contact pad is preferably understood to be a contact section, for example, round and / or oval (in particular elliptical), which is preferably applied by application from the liquid state, for example, by dripping (soldering).

[0037] The terminal strip, preferably comprising copper, and / or the at least one connecting strip, preferably comprising copper, can be thermally sprayed.

[0038] The at least one terminal strip, preferably comprising copper, and / or the at least one connecting strip, preferably comprising copper, can be connected to at least one contact pad, preferably comprising copper.

[0039] Overall, an electric heating device is proposed that can effectively cover the growing demand in electrically powered vehicles (due to their increasing popularity). In the past, so-called PTC heating elements were predominantly used as electric heating devices for such mobile applications. These were operated with comparatively low supply voltages that are present in the on-board electrical system of a conventional motor vehicle with an internal combustion engine. Particularly in modern vehicles that are fully or partially electrically powered, there is a need to be able to operate the vehicles electrically with the supply voltages that are present in a high-voltage on-board electrical system implemented in these vehicles, such as a voltage in a range between 150 volts and 900 volts, possibly even up to over 1,000 volts.

[0040] In the present context, a heating device for mobile applications is understood to mean a heating device that is designed and adapted for use in mobile applications. This means, in particular, that it is transportable (possibly permanently installed in a vehicle or merely accommodated therein for transport) and not exclusively designed for permanent, stationary use, as is the case, for example, with the heating of a building. The weight of the heating device can be less than 500 kg, preferably less than 100 kg, and even more preferably less than 20 kg. The heating device can, if necessary, be permanently installed in a vehicle (land vehicle, ship, etc.), in particular in a land vehicle.In particular, it can be designed to heat a vehicle interior, such as a land vehicle, water vehicle, or aircraft, as well as a (partially) open space, such as that found on ships, especially yachts. The heating device can also be used (temporarily) stationary, for example, in large tents, containers (e.g., construction containers), etc. In particular, the electric heating device can be designed for mobile applications as a parking heater or auxiliary heater for a land vehicle, such as a caravan, mobile home, bus, car, etc.

[0041] The substrate may have a flat or non-flat (e.g., curved or arched) surface. The layer sections (which may run adjacent to one another) separated by separation interruptions are preferably arranged at an (at least substantially) uniform height relative to the substrate surface.

[0042] Preferably, an electrically insulating material is arranged in the isolating interruptions. The electrically insulating material can preferably cover not only the isolating interruptions but also the surface of the heating conductor track(s) facing away from the substrate. The electrically insulating material can particularly preferably be deposited as a layer after the formation of the heating conductor track(s). The electrically insulating material is preferably (relatively well) electrically insulating on the one hand, but (relatively well) thermally conductive on the other. The electrically insulating material allows the width of the isolating interruptions to be kept comparatively small, so that the available surface area of the substrate can be efficiently utilized for the heating conductor track(s).

[0043] According to a further development, at least one further layer is formed on the heating conductor layer. In particular, multiple layers can also be formed on the heating conductor layer. Preferably, an insulating layer can be formed on the heating conductor layer, which may also fill the separation gaps between the track sections of the heating conductor track. A sensor layer for monitoring the function of the electrical heating device can also preferably be formed on the insulating layer. The insulating layer can provide a high degree of safety by additionally insulating current-carrying areas.

[0044] In a specific embodiment, the electric heating device is a motor vehicle heating device. The electric heating device can be designed, in particular, to heat a fluid, such as air for a vehicle interior or a liquid in a vehicle's fluid circuit.

[0045] The above-mentioned object is further achieved in particular by the use of an electric heating device of the type described above for a vehicle, in particular a motor vehicle.

[0046] The design of the electric heating device generally also has the advantage that no (or only minimal) additional space is required on the substrate surface, thus enabling efficient use of the available space. Overall, a comparatively simple and cost-effective design is possible.

[0047] The heating conductor layer is preferably a layer that is deposited flat on the substrate and, if necessary, subsequently structured by material removal. This enables comparatively cost-effective production of the heating conductor track(s). The heating conductor layer can preferably be applied to the substrate by a thermal spraying process and then structured (e.g., by laser processing). In principle, however, other processes such as printing processes, casting processes or the like are also conceivable for forming the heating conductor layer. Other structuring processes are also possible, such as etching, mechanical removal, ultrasound or the like. The heating conductor layer is preferably made of an electrically conductive, in particular metallic, material. Furthermore, the heating conductor layer can have an intermediate, electrically insulating (and, if necessary,The heat conductor layer can be separated from the substrate material by a (highly thermally conductive) intermediate layer. In particular, the heat conductor layer can be formed, for example, from a nickel-chromium alloy and / or separated from the substrate material by an aluminum oxide layer. The substrate can preferably have comparatively good thermal conductivity, in particular, be made of a metal.

[0048] The heating conductor layer or the respective layer section can preferably have a thickness (in the direction perpendicular to the substrate) in the range from 5 µm to 30 µm, in particular in the range from 10 µm to 25 µm.

[0049] A width (or extension perpendicular to a direction of current flow) of a (respective) layer section may be at least 5 mm, preferably at least 25 mm and / or at most 500 mm, possibly at most 100 mm.

[0050] In a specific embodiment, the electric heating device is designed as a high-voltage heater for an operating voltage in the range of preferably between 150 volts and 900 volts, more preferably between 200 volts and 600 volts. However, a design up to over 1,000 volts is also possible. In this case, the electric heating device can be used particularly advantageously, for example, in an electric or hybrid vehicle (without the mandatory need for complex voltage converters).

[0051] Preferably, a HV+ and a HV- potential are separated by structuring (using a separation interruption(s). A thin layer of copper (particularly thermally sprayed) can be applied to the heating conductor layer. In principle, a heating device with, for example, two heating circuits is conceivable. However, the principle of the invention is also applicable to heating devices (or heating elements) with more than two heating circuits.

[0052] In general, structuring effort is comparatively low (e.g., two laser paths per heating device or heating element). Structuring may be possible with an identical parameter set for a laser system, both for a heating element and for a heating element with conductive strips (copper strips).

[0053] A temperature in possible deflection areas (for example twice) is not necessarily significantly increased.

[0054] An additional spraying process may not be necessary, as a metallic strip (copper strip) can be created from the same material as optional contact pads. Due to the comparatively short patterning length, the individual tracks (layer sections) can be masked themselves (for example, instead of subsequent laser patterning). This eliminates the need for a (potentially complex) laser process.

[0055] For example, several heating circuits can be separated from each other by a wire during production.

[0056] The invention is described below using an exemplary embodiment, which is explained in more detail with reference to the figures. Herein: Fig. 1 a schematic plan view of an electric heating device according to the invention.

[0057] In the following description, the same reference numbers are used for identical and equivalent parts.

[0058] Fig. 1 shows a schematic plan view of a heating device according to the invention.

[0059] This comprises a heating conductor layer 12, which can be arranged on a substrate (not shown). The heating conductor layer 12 is divided by separation interruptions 13, 14 into a first layer section 15, a second layer section 16, and a third layer section 17. The separation interruptions 13, 14 separate the corresponding layer sections 15, 16 and 16, 17 (completely) from one another. Overall, however, the layer sections 15 to 17 are not completely separated from one another, but are connected to one another (electrically conductively) via a metallic connecting strip 18 (copper strip).

[0060] Opposite the connecting strip 18, a connecting strip 19 is arranged (in particular metallic, preferably comprising copper). The connecting strip 19 has connection interruptions 20, 21, which continue the interruptions 13, 14 (respectively). This divides the connecting strip 19 into three strip sections 22, 23, 24. The strip sections 23, 24 are in turn connected to one another by a first pole (in particular, the positive pole). The strip section 23 is connected to a second pole (for example, the negative pole). Contact pads (e.g., comprising copper) 25, 26, 27 are also provided for electrical connection.

[0061] A first heating circuit 36 is formed by the first layer section 15 and the second layer section 16. A second heating circuit 37 is formed by the third layer section 17 and the second layer section (common layer section) 16.

[0062] The connecting strip 18 preferably has no interruptions (separation interruptions).

[0063] The connecting strip 18 and / or the connecting strip 19 preferably extend (at least substantially) perpendicular to the layer sections 15, 16, 17.

[0064] Specifically, a first end 28 of the first layer section 15 is connected to a first terminal 29 (or first pole 29, e.g., positive pole, in particular HV+). Similarly, a first end 30 of the third layer section 17 is connected to the first terminal (pole) 29. A second end 31 of the first section 15 and a second end 32 of the third layer section 17 are each connected (via the connecting strip 18) to a second end 33 of the second layer section 16. A first end 34 of the second layer section 16 is connected to a second terminal 35 (second pole, e.g., negative pole, in particular HV-).

[0065] In this sense, a respective connection (this applies in particular to connection 29) does not have to be designed as a single piece or as a continuous unit. Reference symbol

[0066] 12Heating conductor layer 13Isolation break 14Isolation break 15First layer section 16Second layer section 17Third layer section 18Connecting strip 19Connecting strip 20Connection interruption 21Connection interruption 22Strip section 23Strip section 24Strip section 25Contact pad 26Contact pad 27Contact pad 28First end of 15 29First connection 30First end of 17 31Second end of 15 32Second end of 17 33Second end of 16 34First end of 16 35Second connection 36First heating circuit 37Second heating circuit

Claims

1. Electric heating device with: a substrate formed of metal and a heat conductor layer (12), which is separated from the substrate by an intermediate electrically insulating layer, formed on the substrate, wherein the heat conductor layer (12) is interrupted by at least a first isolating interruption (13), wherein the first isolating interruption (13) separates at least a first (15) and a second (16) layer portion of the heat conductor layer (12) from each other, wherein the first layer portion (15) is connected at a first end (28) to a first terminal (29) and the second layer portion (16) is connected at a first end (34) to a second terminal (35), wherein the first layer portion (15) is connected at a second end (31) to the second layer portion (16) and is connected via this second layer portion (16) to the second terminal (35) characterized in that a separate conductive strip (19) is at least partially associated with the first (29) and second (35) terminal, wherein at least one isolating interruption (20) of the separate conductive strip (19) merges into and / or is aligned with and / or is arranged on the same line as the at least one isolating interruption (13).

2. Electric heating device according to Claim 1, characterized in that the heat conductor layer (12) is interrupted by at least a second isolating interruption, wherein the second isolating interruption (14) preferably separates a third (17) and the second (16) layer portion of the heat conductor layer (12) from each other, wherein the third layer portion (17) is preferably connected at a first end (30) to the first terminal (29).

3. Electric heating device according to one of the preceding claims, characterized in that the first (15) and second (16) layer portions are at least partially connected to each other by a separate connecting strip (18).

4. Electric heating device according to one of the preceding claims, characterized in that the first (29) and second (35) terminal are arranged on the same side of the heat conductor layer (12).

5. Electric heating device according to one of the preceding claims, characterized in that at least one isolating interruption (13, 14) is at least substantially straight.

6. Electric heating device according to one of the preceding claims, characterized in that the heat conductor layer (12) and / or the first (15) and / or the second (16) and / or the third (17) layer portion thereof is / are at least substantially rectangular.

7. Electric heating device according to one of the preceding claims, characterized in that the heat conductor layer (12) covers at least 80% of a substrate surface, preferably at least 85% of the substrate surface, and / or an electrically insulating material is arranged in the particular isolating interruption (13, 14) and / or at least one further layer, in particular an insulating layer, is formed on the heat conductor layer (12).

8. Electric heating device according to one of the preceding claims, characterized in that the second layer portion (16) is wider than the first (15) and / or third (17) layer portion, preferably at least by a factor of 1.2; further preferably at least by a factor of 1.5.

9. Electric heating device according to one of the preceding claims, characterized in that two or more heating circuits (36, 37) are formed.

10. Electric heating device according to one of the preceding claims, characterized in that at least one isolating interruption (13, 14) passes through the heat conductor layer (12) from a first to a second side thereof, in particular completely.

11. Electric heating device according to one of the preceding claims, characterized in that the electric heating device is a motor vehicle heating device.

12. Vehicle, in particular motor vehicle, comprising an electric heating device according to one of the preceding claims.

13. Method for producing an electric heating device according to one of claims 1 to 11, wherein at least one isolating interruption (13, 14) is produced by laser structuring and / or masking of at least one masking portion when applying the heating layer and / or an elongate body, in particular wire, which is introduced during production and is later removed again, and / or at least one terminal strip (19), preferably comprising copper, and / or at least one connection strip (18), preferably comprising copper, are thermally sprayed and / or are connected to at least one contact pad (25, 26, 27), preferably comprising copper.

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