Electric heating device for vehicle

Abstract

An electric heating device (1) for a vehicle, in particular an electric or hybrid vehicle, comprising: a heating device housing; at least one heating element (34) configured for a heating operation at an operating voltage in a high voltage range; a heat exchanger (2) in thermal contact with the at least one heating element (34) to transfer heat generated by the heating element (34) to a medium flowing through the heat exchanger (2); and a control module (4). The control module comprises a control device (40) configured to be able to provide an operating voltage in a high voltage range to the at least one heating element (34) and to control the heating operation of the at least one heating element (34). According to the invention, the control module (4) has a first module housing (41), which is part of the heating device housing, is formed from plastic and accommodates the control device (40) inside the first module housing (41).

Description

[0001] Cross - reference to related applications

[0002] This application claims priority to German National Patent Applications Nos. 10 2022 128488.3 and 10 2022 128 489.1, filed with the German Patent and Trademark Office on October 27, 2022, the disclosures of which are incorporated herein by reference in their entirety and for all purposes. Technical field

[0003] The present invention relates to a heating device and a heater, preferably a high - voltage heater, for a vehicle, in particular an electric or hybrid vehicle. Background art

[0004] Heating devices are commonly used in vehicles to heat the interior space or passenger compartment or components such as batteries. In electric or hybrid vehicles, electric heating devices are typically used, where air or water is used as the heat - transfer medium or fluid, because due to the lack of an internal combustion engine, the use of waste heat is no longer an option, and such fuel - based stationary or auxiliary heating systems are neither technically feasible nor economical in this case. In addition to the heat - transfer media mentioned, other heat - transfer media are also possible.

[0005] Electric heating devices can operate particularly efficiently in the high - voltage range achievable in pure - electric or hybrid - electric vehicles. Compared to conventional vehicles with a fuel - powered engine (where the on - vehicle power supply system is only powered by a 12 - volt lead - acid battery), electric vehicles use the vehicle battery as an energy storage device, which allows operation at a higher voltage and thus enables meaningful driving in the first place due to the higher power of the electrical equipment.

[0006] For larger electrical equipment in vehicles with an output power of 3 kW and above, such as start - stop functions (including energy recovery), electric air - conditioning compressors, and heaters, a level of 48 volts has been established for some time. In contrast to these levels, the on - vehicle electrical system architecture in pure - electric or hybrid - electric vehicles with relatively large units (e.g., greater than 12 kW) employs the high - voltage range. In the automotive industry, the voltage of the on - vehicle electrical system is typically 250 - 800 V or higher. For example, a value of 60 V is generally regarded as the lower limit of the high - voltage range (see "Spannungsklassen in der ",Hrsg.:Zentralverband Elektrotechnik - und Elektronikindustriee.V.(ZVEI),Frankfurt,December 2013”).

[0007] For vehicles equipped with a high-voltage on-board electrical system, high-voltage heaters for electrically heating a medium or a fluid circuit via a heat exchanger are well known. For example, by means of a heating element configured as a thin-film resistor, electrical energy can be efficiently converted into heat. The thin-film resistor directly or indirectly contacts the heat exchanger in order to transfer the generated heat to the fluid flowing through the heat exchanger, and the heat is then conducted to a location or component where the heat can be released again.

[0008] The heating element is usually powered by a power supply and controlled by a control device. For example, when supplied with a DC voltage in the high-voltage range, the heating element can be operated by the control device in a pulse-width modulation manner in order to achieve a specific heating output, especially in the case of heating control. The corresponding switching frequency of the power switching elements required for this can be in the kilohertz range, without limiting generality, for example in the range from 1 to 250 kHz.

[0009] The combination of high voltage and sometimes high-frequency switching cycles usually requires measures in terms of electromagnetic compatibility (EMC), especially in vehicles where there may be interference or interaction with other electronic devices. In addition to known circuit measures, sufficient shielding must also be considered. Therefore, the electronic components of the high-voltage heater are usually installed in a metal housing, where the metal housing is usually at the ground potential of the power supply in order to meet safety requirements. Materials such as die-cast aluminum or deep-drawn steel sheet structures can be used.

[0010] However, such a housing must also provide protection against moisture and contamination for the electronic components it contains and must therefore have a certain degree of sealing, and can also have a complex structure to meet various requirements. This may require a multi-component structure, especially with regard to the limited forming possibilities during the manufacturing process, the required or desired cable sleeves and their insulation, which usually increases the cost and manufacturing expenses of the high-voltage heater. Summary of the Invention

[0011] Therefore, an object of the present invention is to provide an electric heating device for a vehicle, especially an electric or hybrid vehicle, which takes into account the complexity of the requirements for the housing structure while reducing the deficiencies in terms of cost and workload.

[0012] According to one aspect, there is provided an electric heating device for a vehicle, in particular an electric or hybrid vehicle, comprising: a heating device housing; at least one heating element configured to perform a heating operation at an operating voltage within a high voltage range; a heat exchanger thermally connected to the at least one heating element to transfer heat generated by the heating element to a medium flowing through the heat exchanger; and a control module including control means configured to supply the at least one heating element with an operating voltage within the high voltage range and to control the heating operation of the at least one heating element. The control module has a first module housing which is part of the heating device housing, the first module housing being formed of plastic and accommodating the control means.

[0013] A vehicle is generally understood to mean all possible mobile applications, in particular passenger cars, trucks, construction machinery, aircraft and ships. This also includes, for example, construction machinery or cranes as well as trailers, such as caravans which can be towed and transported by other vehicles.

[0014] A basic idea of this aspect is to provide a housing made of plastic for at least a part of an electric heating device designed as a high voltage heating device which includes control means. Within the overall concept of the present invention, the first module housing can also be an integrated part of the heating device housing and include other components, such as heating elements and / or heat exchangers. The specific embodiments described below provide a first module housing configured as a module housing separate from another (second) module housing of the heat exchanger and / or the heating element, but which is firmly connected as a part of the heating device housing to the other module housing, wherein the two module housings together form the heating device housing as parts.

[0015] Since the first module housing is made of plastic, a more complex shape of the module housing can be easily achieved. The injection molding process has a greater degree of freedom in geometric design compared to the processes available for metalworking. In addition, the manufacturing cost is lower, especially in terms of material cost. In addition, for example, in the case of plastic injection molding, the durability or reusability of the casting tool is significantly greater than in the case of aluminum die casting, and thus a cost reduction is also achieved here.

[0016] In terms of electromagnetic compatibility, it has been found that the corresponding requirements can be met by considering conductive materials embedded in the plastic, and thus sufficient electromagnetic shielding can be provided. According to specific embodiments, these materials can be, on the one hand, metal inserts and / or, on the other hand, conductive fibers, in particular carbon fibers, which will be described in more detail below.

[0017] The use of plastics - in particular its property allowing the generation of electrically conductive regions and electrically insulating regions in the same molding process - increases the design flexibility of the first module housing and also enables local electrical insulation channels for the live cables, preferably in the low voltage range, so that in this case additional seals and precisely fitting plug-in connectors can be dispensed with.

[0018] The control device may have or be implemented by a printed circuit board on which one or more microcontrollers and other electronic components are arranged. The one or more microcontrollers may implement, for example, communication with a vehicle power supply unit (BCM) or an electronic control unit (ECU). Corresponding circuit connection structures may be implemented on the circuit board. In addition, connection points for connection to an external energy source (vehicle battery) may be implemented. Furthermore, the one or more microcontrollers may perform the control of power switching elements (e.g., power MOSFETs or IGBTs), which may also be placed on this printed circuit board or another printed circuit board, etc. In the case of another printed circuit board, the other printed circuit board may be arranged separately from the control device as a power switching component adjacent to the heating element and optionally outside the first module housing.

[0019] The control device may be configured to be able to perform heating control. One or more temperature sensors may be placed on or at least near the heat exchanger and electrically connected to the control device to detect the fluid temperature and transmit a corresponding signal to the control device. The control device or the microcontroller of the control device may compare the temperature or a value derived from the temperature with a threshold or a target value and adjust the heating power according to the result in order to set a desired target temperature in the fluid (e.g., at the fluid outlet).

[0020] To control the heating power, the control device may operate the power switching element by means of pulse width modulation. For this purpose, the operating voltage in the high voltage range is preferably a direct current voltage.

[0021] It should be noted that the electric heating device according to the aspects and embodiments described herein may in particular be a liquid heating device. A liquid heating device means that the medium flowing through the heat exchanger of the heating device is a liquid. In particular, the medium may be the liquid coolant of a vehicle, which transfers heat in the vehicle and may release heat at various points. Additionally or alternatively, the liquid heating device may also be a component of, for example, a vehicle heat pump, such that the heat transfer medium may be or may include, for example, the refrigerant of the heat pump. The refrigerant may only exist in a completely liquid form under certain conditions and only temporarily, or may never occur, while in other cases, the refrigerant is partially or completely gaseous. Nevertheless, this can also be understood as a liquid heating device.

[0022] The heat output of the liquid heating device can preferably be at least 5 kW, preferably at least 7 kW, for example at least 9 kW. In each case, the heat output is preferably less than or equal to 13 kW.

[0023] The operating voltage at which the vehicle heating device (or heating element) operates can be equal to the on-vehicle voltage or the power supply voltage of the electric vehicle, and this operating voltage can be greater than or equal to 60 V, preferably 400 V, more preferably greater than or equal to 700 V, for example 800 V, 900 V or 1000 V.

[0024] The liquid heating device has at least one heating element. The control device can also operate multiple heating elements independently of each other or in parallel. One or more heating elements can have a heating conductor layer that acts as a thin-film resistor. Preferably, the liquid heating device has at least two heating elements, particularly preferably at least three heating elements.

[0025] The heating conductor layer can preferably have corresponding heating conductor tracks. The heating conductor layer and the heating conductor tracks can be arranged together on a single carrier element. Preferably, each heating conductor layer or each heating conductor track is applied to its own separate carrier element. The carrier element can also be the wall or plate of a heat exchanger, such that the heat exchanger and the heating element can share a single element.

[0026] The heating element or the heating conductor layer can be implemented in various ways, and the present invention is not limited to specific embodiments of the present invention. For example, the heating element can consist of a thermal spray coating. For example, during the manufacturing process, atmospheric plasma spraying can be used as the coating process. The heating element can also be applied on both sides of the heat exchanger, that is, also on the cover wall and the bottom wall of the heat exchanger. Starting from the flat plate formed by the cover wall or the bottom wall of the heat exchanger, the layer structure is first an optional adhesive substrate, followed by an insulating ceramic, the actual heating conductor layer, and (if necessary) a top layer or a sealant. The heating conductor layer can be structured by laser or by means of a mask. The material of the heating conductor can be a material with linear or PTC resistance characteristics.

[0027] Polymer-based heating elements with PTC characteristics can also be considered. These heating elements can be heating elements made of plastic films. The heating elements generally consist of an extruded or laminated polymer matrix, in which heating conductors and positive and negative electrodes are embedded.

[0028] In addition, the heating element can also be a ceramic heating element (PTC thermistor) with PTC characteristics.

[0029] In addition, the heating element can be designed as a thick-film heating element. In this case, the carrier element can also be a plate of the heat exchanger. The thick-film heating element can be a dielectric and a heating conductor to represent a planar heating resistance, which is applied to the plate.

[0030] The heating element can also be designed as a ceramic substrate (as the carrier element), for example made of Al 2 O 3 and having a screen-printed heating conductor layer. The heating conductor layer can be designed, for example, as a metallized structure made of a resistive alloy, which represents the corresponding heating resistance. Among them, iron-nickel alloys or nickel-chromium alloys can be considered. The insulation breaks ensure the structuring of the long conductor paths, which come from an additional flat application and subsequent baking of the layer, and may have been produced, for example, during the application by means of a screen-printing process. The ceramic substrate can be a ceramic support plate. This embodiment of the heating element is preferred according to aspects of the present invention.

[0031] In the case of the described polymer-based heating element with PTC characteristics, the ceramic heating element with PTC characteristics, or the heating element as a ceramic substrate with a screen-printed heating conductor layer, the flat heating element can be applied to the outer side of the cover wall or the bottom wall, which is usually configured as a flat plate, by means of a heat medium (such as a thermally conductive adhesive) as an adhesive layer. However, the heat medium can also be used in combination with an extrusion device.

[0032] It should be noted that according to an embodiment of the present invention, the heating element can also be applied to both sides of the heat exchanger, that is, to the cover wall and the bottom wall.

[0033] The heat exchanger itself can be made of, for example, steel or aluminum, preferably also as a metal plate heat exchanger. According to a specific embodiment, the boundary walls forming the flat fluid chambers of the heat exchanger include a cover wall, a bottom wall opposite the cover wall, and narrow side walls connecting these walls, which are formed, for example, by grooved deep drawing of the cover wall or the bottom wall, wherein the fluid inlet and the fluid outlet are formed, for example, in the bottom wall. The cover wall and the bottom wall are preferably flat and substantially extend along the plane defined by the heat exchanger.

[0034] The described design of the heat exchanger is only exemplary but advantageous, characterized in that the installation height perpendicular to the cover wall is significantly smaller than the width and length of the heat exchanger extending parallel to the cover wall, to which the heating element can be attached, or the heating element can also form the cover wall.

[0035] According to an exemplary embodiment, the heat exchanger may preferably be designed in two parts. The heat exchanger may have a base member and a cover member, and the base member and the cover member are connected to each other in an integrally connected manner, and may also be in a form-fitting and / or frictionally engaging manner (in particular by welding or soldering) together with a turbulator inserted therein. The bottom wall may form part of the base member together with the side walls, while the cover wall may be part of the cover member preferably designed as a flat plate. The cover wall and the cover member may be the same.

[0036] The turbulator may preferably have a filament structure and include a grid structure. Preferably, the turbulator is in at least thermally conductive contact with the cover wall so as to conduct the heat transferred via the cover wall into the grid structure, and the fluid flows around the grid structure, so that due to the large contact surface between the fluid and the grid, the fluid efficiently absorbs heat. The turbulator may change the fluid flow in the internal space into a turbulent flow, so that the medium or fluid flowing through the internal space is better mixed, which further improves the efficiency of the heat exchanger. The grid-like turbulator may be made of a single piece of metal, for example. For production, grooves may first be punched in the metal sheet. Then, for example, by "accordion-like" folding, the grid-like structure of the turbulator may be produced. The turbulator may be made of the same material as the bottom wall and / or the cover wall. Preferably, the turbulator is also attached to the bottom wall to prevent dynamic expansion and thus prevent changes in hydrodynamic conditions caused by the high pressure of the flowing fluid. As an alternative to inserting a continuous grid-like turbulator, the bottom wall and / or the cover wall may also have a large number of protrusions which, when assembled, project into the internal space, thus also forming a grid-like turbulator at the internal space. Other embodiments of the heat transfer mechanism are also possible.

[0037] According to a specific embodiment of the present invention, the heat exchanger and at least one heating element form a heat exchanger module and are accommodated in a second module housing. The heat exchanger and the at least one heating element form an independent unit relative to the control module, but are structurally and electrically connected to the control module. The first module housing is a component different from the second module housing. According to the above embodiment, the second module housing may be formed by a trough-shaped base member of the heat exchanger and a housing cover attached to the base member or attached to the heat exchanger, for accommodating the heating element (and optionally associated power switching components). In particular, the second module housing may be made of steel plate and / or die-cast aluminum, etc.

[0038] According to a specific development of the described aspects and embodiments, the first module housing has a first layer of conductive plastic material. A layer should be understood here as a planar structure. In this regard, it is not necessary for the layer to provide an almost complete enclosure of the internal space; channels and dedicated insulated wall areas are also possible, as provided by further embodiments described below.

[0039] However, it has been found that if the first layer of the electrically conductive plastic material extends at least over a major or significant part of the module housing wall, this layer can achieve a wide shielding in terms of electromagnetic compatibility, especially in the high voltage range of the heating operation. Therefore, from the EMC point of view, this layer can surely replace the conventional metal housing in terms of effect.

[0040] According to an exemplary embodiment, the electrically conductive plastic material is a plastic reinforced with carbon fibers. According to a further embodiment, the mass fraction of the carbon fibers can be between 10% and 80%, preferably between 20% and 60%, more preferably between 30% and 50%, still more preferably between 35% and 45%, and ideally around 40%. In the case of around 40%, the most satisfactory results are obtained simultaneously in terms of strength, elastic behavior, durability, injection molding performance, electrical properties, and thermal properties.

[0041] The plastic used, in which the carbon fibers are incorporated or embedded, is preferably a temperature-resistant and heat-resistant plastic, especially a thermoplastic plastic, preferably PPS (polyphenylene sulfide). The carbon fibers can be any type of fiber, including HT - high toughness, UHT - ultra-high toughness, LM - low modulus, IM - intermediate (intermediate modulus), HM - high modulus, UM - (super modulus), UHM - (ultra-high modulus), UMS - (super modulus strength), HMS - high modulus / high strength (high modulus / high strain). The filament size as well as the density of the filaments or fibers in the polymer matrix are selected to achieve (among other factors) the electrical properties required for the application in question.

[0042] Another embodiment provides that the first module housing has a second layer of electrically insulating plastic material. Such a second layer, especially in combination with the first layer of electrically conductive plastic material, enables the EMC requirements in the high voltage range (first layer) to be met simultaneously and creates a wall area in the first module housing of the control module which, due to complete insulation (formed only by the second layer), allows cables to easily pass through the housing wall (for example, for a low voltage plug integrated into the wall).

[0043] However, it should be particularly emphasized that since the first layer has a significantly higher resistivity compared to aluminum die casting, for example, although the first layer is electrically conductive, the second layer applied to the outer surface of the first layer increases the safety of a person in contact with the heater (for example, when repairing the heater or adjacent components) against harmful electric shocks to health.

[0044] Depending on the development of these aspects, the electrically insulating plastic material can be a plastic reinforced with glass fibers. According to a further embodiment, the mass fraction of the glass fibers can be between 10% and 80%, preferably between 20% and 60%, more preferably between 30% and 50%, still more preferably between 35% and 45%, and ideally about 40%. In the case of about 40%, the most satisfactory results are obtained simultaneously in terms of strength, elastic behavior, durability, injection molding performance, electrical properties, and thermal properties, especially in combination with the corresponding properties of the first layer.

[0045] According to the above example, the first module housing can correspondingly have a two-component structure, wherein the second layer forms the exposed outer surface of the first module housing on the outside, while the first layer largely surrounds the internal space of the module housing on the inside relative to the second layer, and wherein the first layer and the second layer are preferably molded together and form an integral part. The first layer can also optionally form the surface defining the internal space of the first module housing, but it can itself also be completely or partially coated towards the internal space. It should be noted that the internal space can be at least partially filled with a potting or filling compound to protect the components installed therein (moisture, mechanical damage, heat dissipation). Importantly, the first layer is effectively configured for EMC shielding, and for this purpose, it surrounds to a certain extent (i.e., largely) the internal space in which the components are installed to achieve this goal. As long as the EMC shielding is not impaired, the omission of a single opening or a single smaller insulating wall area can be tolerated. Various examples are described below.

[0046] This does not exclude the first module housing being formed by a base part and a cover during the manufacturing process before assembly. These two parts are preferably made of parts in an injection molding process and can then be joined together by ultrasonic welding, gluing, or other sealing joining processes (after installing additional components such as, for example, a control device (printed circuit board) in particular).

[0047] According to another exemplary embodiment, in the first module housing of an electronic heating device, the high-voltage connector part can be configured as a separate, subsequently installed component, which is at least partially surrounded by a metal ring connected to the ground potential, and wherein the metal ring is embedded in the first layer of the conductive plastic material and / or is located between the first layer and the second layer and is at least in contact with the first layer. The metal ring can preferably be made of aluminum, copper, or a steel plate.

[0048] That is to say, it has been found that due to this process, especially in the case of two-component injection molding, at the edge of the mold, the density of carbon fibers will decrease. The opening formed in the first module housing forms such an edge, which is subsequently closed only by inserting a separate connector part. However, the high-voltage connector part (and possibly other parts) forms the wires for providing high-voltage on-vehicle power supply or supply voltage, which preferably also requires special shielding. The metal ring can thus further support the shielding at this point, which is a "nerve pain point". By embedding the metal ring in the first layer of conductive material, the metal ring has been connected to the conductive part of the housing.

[0049] If the metal ring is conductively connected to the metal support plate of the heat exchanger module (preferably a flat cover wall, according to the embodiment, the cover wall laterally protrudes beyond the actual fluid chamber, thus defining an attachment part) via a first metal conductor embedded in the conductive plastic material, the shielding is further improved. This also improves the ground potential connection of the first layer in which the ring and the metal wire are embedded, which forms a "drainage channel" for the potential equalization of charges. Similarly, the metal ring can additionally or alternatively be connected to the ground connection structure of the printed circuit board of the control device via a second metal wire embedded in the conductive plastic material. The effect here is similar.

[0050] Furthermore, as described above, the low-voltage connector part can be arranged in a part of the first module housing, where the first layer of conductive plastic material does not extend in this part, such that the wall in the area of this part of the first module housing is basically formed only by the second layer of electrically insulating plastic material. As described above, this enables the formation of an insulating connector part integrated in the housing wall, which saves additional parts and components.

[0051] In addition, an exemplary embodiment provides that at least one hole is formed in the first module housing for an electrical connection structure between the control device in the first module housing and the power switching component for switching the heating element in the second module housing to pass through the at least one hole. In this case, a stamping grid (Stanzgitter), especially a lead frame, with conductor traces embedded in a common plastic part can be arranged in the at least one hole, where the conductor traces contact the corresponding connection points on the printed circuit board forming the control device.

[0052] The stamping grid enables a firm electrical connection to the power switching element and / or to the heating element and allows for a space-saving change of the side of the heat exchanger, since the first housing module is preferably attached to the second housing module in a direction substantially perpendicular to the plane of the heat exchanger, such that in the state of being installed in a vehicle, the connection elements (fluid inlet, fluid outlet) and the connector parts (high voltage, low voltage) can be accessed from the same side. However, this in turn requires the heating element to be arranged on the opposite side of the flat heat exchanger. Therefore, the through holes in the support plate of the heat exchanger allow direct access to the second module housing from the side where the heating element is located.

[0053] Advantageously, the stamping grid and the through holes formed in the support plate and the holes formed in the first module housing and aligned with the through holes can extend into the interior space of the first module housing, where they are fixed to the printed circuit board forming the control device by means of at least one positioning device, in particular a positioning pin.

[0054] To fix the two module housings to each other, fastening means, in particular one or more screws, can be provided to fasten the support plate of the heat exchanger module to the first module housing, wherein the support plate has through holes aligned with at least one hole in the first module housing, such that the stamping grid extends through the through holes of the support plate and provides a contact connection structure for the conductor tracks on the opposite side of the stamping grid.

[0055] A seal can be installed between the facing surfaces of the support plate of the first module housing and the second module housing (of the heat exchanger), which seal closes the at least one through hole or the at least one hole (in the case of multiple through holes and associated holes, closing them together), thereby protecting the interior space of the first module housing and the interior space of the second module housing including the power switching components and the heating element from moisture intrusion.

[0056] Further embodiments of the invention can be found in the appended dependent claims. Description of the Drawings

[0057] The exemplary embodiments of the invention will be explained in more detail below with reference to the drawings. The drawings show:

[0058] Figure 1 is a perspective view of a high-voltage electric heating device according to an exemplary embodiment;

[0059] Figure 2 is Figure 1 a top view of the arrangement structure of the heating elements on the support plate of the heat exchanger of the heating device shown;

[0060] Figure 3 is Figure 1Perspective view of the control module of the heating device, showing the outer second layer of the electrically insulating plastic material;

[0061] Figure 4 Same as Figure 3 but with the high - voltage connector part hidden;

[0062] Figure 5 Same as Figure 4 but showing the inner first layer of the conductive plastic material, with the second layer hidden;

[0063] Figure 6 Same as Figure 5 but with the first and second layers hidden (only the base part and the cover are visible);

[0064] Figure 7 Separate illustration of the positioning structure of the stamping grid, fastening screws, metal sheet inserts, and seals;

[0065] Figure 8 Perspective view of the inner space of the first module housing according to an exemplary embodiment;

[0066] Figure 9 Perspective view of the first module housing seen from the rear, with the second layer as the outer surface;

[0067] Figure 10 Same as Figure 9 but with the second layer hidden, i.e., showing the inner first layer;

[0068] Figure 11 Same as Figure 8 but with all the electronic components including the control device installed, and the cover removed;

[0069] Figure 12 Same as Figure 11 but with the control device hidden (the circuit board and the potting or filling material are hidden);

[0070] Figure 13 Perspective view of the first module housing seen from below, without the stamping grid;

[0071] Figure 14A Perspective view of one of the stamping grids;

[0072] Figure 14B From Figure 14A Another perspective view of the stamping grid. Detailed Description

[0073] In the following description of the preferred exemplary embodiments, it should be noted that various aspects of the present disclosure are not limited to the details of the structure and arrangement of the components shown in the following description and the drawings. The exemplary embodiments can be practiced or implemented in various ways. It should also be noted that the expressions and terms used herein are for the purpose of specific description only and should not be construed in a restrictive manner by those skilled in the art. In addition, in the following description, the same reference numerals in the exemplary embodiments or the drawings represent the same or similar features or objects. Therefore, in some cases, the repeated detailed description of the same or similar features or objects is omitted to keep the description concise and clear.

[0074] Figure 1 A perspective view of an exemplary embodiment of an electric heating device 1 according to the present invention is shown. In particular, this is a high-voltage liquid heating device for an electric or hybrid vehicle.

[0075] The electric heating device 1 basically includes three components, namely a heat exchanger 2, a heat conversion unit 3, and a control module 4. The heat exchanger 2 and the heat conversion unit 3 can be structurally combined to form a heat exchanger module 5, and the control module 4 is attached to the heat exchanger module 5. The heat exchanger module 5 has a generally flat structure with a rectangular profile in a top view.

[0076] In Figure 1 the heat exchanger 2 is oriented upward and has a deep-drawn base member 24, which together with a flat or horizontal cover member 25 forms an equally flat fluid chamber 26 (in Figure 1 the base member is at the top and the cover member is at the bottom). The flat peripheral edge of the base member is welded or fused to the cover member to enclose the fluid chamber at the sides. Since Figure 1 the base member 24 in

[0077] rests on the cover member 25 (only indicated by the arrow), the cover member 25 is hardly visible. A turbulator (not shown in the figure) is inserted into the fluid chamber 26, which mixes the flowing fluid as described above and supports heat transfer to the fluid. The fluid can flow into the fluid chamber through the fluid inlet 21 and, after heating, flow out again through the fluid outlet 22.

[0078] The cover member 25 is configured as a flat plate and is hereinafter referred to as the support plate 25. In a particular embodiment, the base member 24 of the heat exchanger 2 and the housing cover 31 of the heat conversion unit 3 together form a second module housing 42 for the heat transfer module 5.

[0079] Figure 2 A top view of the heating element 34 and the power switching component 35 in a state of being mounted on the support plate 25 of the heat exchanger 2 is shown. In an exemplary embodiment, the heating element is configured as a ceramic substrate (as a support element), for example made of Al 2 O 3 and having a screen-printed heating conductor layer. The heating conductor layer is designed as a metallized structure made of a resistive alloy and provides a corresponding heating resistance. The insulation breaks ensure the structuring of the long conductor path 36. The ceramic substrate can be attached to the flat support plate 25 via a thermally conductive adhesive layer (not shown).

[0080] The resistance of the heating conductor track 36 (defined by the thickness, length, width, and specific film resistance of the material used) is configured such that it can generate a desired heating power at the operating voltage provided in the high voltage range (800V in this example), preferably with a combined power in the range of 5 - 13 kW.

[0081] The power switching component 35 is configured as a printed circuit board and has a plurality of power switching elements (not shown), such as IGBTs or power MOSFETs, by means of which the heating element 34 can be operated under PWM control. For this purpose, the corresponding connection pads of the heating conductor track 36 are connected to the power switching elements on the power switching component 35 via a bonding connection structure 37.

[0082] The power switching component 35 also has a temperature sensor 38, which can detect the temperature to control the heating operation. In an exemplary embodiment, the position of the temperature sensor 38 on the power component corresponds to the fluid inlet 21 and the fluid outlet 22 located at the rear of the support plate 25.

[0083] The power switching component 35 is connected via a further bonding connection structure 39 to the corresponding connection structures formed at three stamping grids 8, and the three stamping grids 8 are assigned to the corresponding heating elements 34. The bonding connection structure 39 contains wires for the power supply (high voltage), for controlling the power switching elements, and for communicating with the temperature sensor. The stamping grids 8 are arranged in the through-holes 27 of the support plate 25, and the through-holes 27 are arranged in the attachment area 52 of the support plate 25, and the attachment area 52 is for attaching and fixing the control module 4.

[0084] The control module 4 includes a control device 40, a first module housing 41 that houses the control device 40, and a high-voltage connector portion 6 and a low-voltage connector portion 7 disposed in the first module housing 41. The first module housing 41 has a generally cubic structure. The portions 7 and 8 are designed here as built-in connectors into which the coupling structures for the corresponding high-voltage and low-voltage connections on the vehicle can be inserted.

[0085] Figures 3 to 6 A more precise detail of the structure of the control module 4 is shown, where the elements are successively hidden in Figure 1 a perspective view to allow the internal space of the control module 4 to be seen.

[0086] In Figure 3 , only the control module 4 and the power switching component 35 connected to the control device 40 are shown. As can be seen from the figure, the first module housing 41 has a base member 411 with a complex geometry and a substantially flat cover 412 that closes the opening of the base member 411 (pointing rearward in Figure 3 ) and is fixed to the base member 411 by ultrasonic welding. The base member 411 and the cover 412 define an internal space 413 ( Figure 3 not shown in the figure), and the control device 40 is disposed in the internal space 413. Figure 3 Also shown is the bonding connection structure 37 from the heating element 34 ( Figure 3 not shown in the figure) to the power switching component 35, and to some extent, also shown is the additional bonding connection structure 39 from the power switching component 35 to the stamping grid 8, which in turn is connected to the control device 40.

[0087] Figure 3 Also shown is a pressure balance opening 419 that connects the external environment to the internal space 413 of the first module housing 41. On the inside, a Gore-Tex membrane 491 is attached at this point (e.g., by ultrasonic welding) to prevent moisture from entering; see Figure 8 (the housing with only the pressure balance opening 419, without other elements) and Figure 12 (with the membrane 491).

[0088] Figure 4 Shows the same view as Figure 3 , but the high-voltage connector portion 6 is hidden. This shows the opening 414 for the high-voltage connector portion 6, which is configured as a separate component that will be inserted into the opening 414 and fixed with a screw 415.

[0089] The first module housing 41 is largely formed of a two-component plastic material. In particular, the first module housing 41 includes an inner first layer 44 and an outer second layer 45. In Figure 3 and Figure 4 the views are directed towards the outer surface of the first module housing, so that the outer second layer 45 is recognizable. The outer second layer 45 is made of an electrically insulating plastic. In particular, this is a thermoplastic material reinforced with glass fibers, such as PPS. The proportion (by mass) of glass fibers in this material is 40%.

[0090] Figure 5 Shows the first module housing 41 from the same viewing angle as in Figure 3 or Figure 4 but with the second layer 45 hidden in order to clearly show the inner first layer 44 made of a conductive plastic material. The plastic material is a thermoplastic material reinforced with carbon fibers. The proportion (by mass) of carbon fibers is 40%. For example, the thermoplastic material here is also PPS, so that the two layers have similar and thus compatible thermal properties. PPS is considered to be fireproof and is therefore particularly suitable for heating appliances.

[0091] To manufacture the first module housing 41, the two plastic material components are injection molded one after the other. First, the plastic material for the first layer 44 is injection molded, and then, when the temperature is still slightly above 100 degrees, it is removed with a rotating plate and the plastic material is injected to form the second layer. The temperature ensures good adhesion but does not cause mutual fusion and mixing. As Figure 5 shown, in order to further improve the mutual adhesion and thus ensure a permanent single-piece integrity, the corrugations 415 formed during the injection molding process can be seen in the first layer 44, and this is correspondingly reflected in the second layer 45 (not shown) injected onto the first layer 44.

[0092] In addition, as can be seen from Figure 5 the first layer 44 does not extend in the part 442 where the low-voltage connector part 7 is not formed. Instead, this area is filled by the second layer 45 so that the low-voltage connector part 7 is integrally molded in the first module housing 41 (rather than a component to be subsequently fixed). As shown in the perspective view of the inner space 413 of the first module housing 41 in Figure 12 the pins 71 of the low-voltage connector part 7 extend directly through the second layer 45 and are thus insulated from each other.

[0093] It can also be seen from Figure 5 that in Figure 4 each self-tapping screw 415 for fixing the high-voltage connector part 7 (see Figure 3 ) forms a relatively small hole 451 in the second layer 44, while the first layer is excluded; see Figure 5The larger holes 441 in it. This ensures that no high-voltage voltage reaches the surface via the screw 415, and due to the material of the first layer 44, the high-voltage voltage cannot dissipate quickly enough.

[0094] In addition, as can be seen in Figure 5 , the recess 443 in the first layer 44 surrounds the opening 414 for the high-voltage connector part 6. Hidden in Figure 5 but shown in Figure 6 , the metal ring 91 of the metal sheet insert 9 is embedded in the recess, and when the high-voltage connector part 6 is inserted into the area of the opening 414 and a heating operation is in progress, it serves as a shield in the area of the opening 414. With the metal sheet insert integrated into the two-component plastic material, the base member 411 is at least a three-component material.

[0095] The metal sheet insert 9 also has a first metal wire 92 and a second metal wire 93, as shown in Figure 7 , and they are also at least partially embedded in the first layer 44. The first metal wire 92 extends from the metal ring 91 to a connection structure on the support plate 25, which is formed by one of the four fastening screws 28 for fixing the control module 4 to the support plate 25. The second metal wire 93 extends from the metal ring 91 to a connection structure on the printed circuit board 401 of the control device 40. The metal ring 91 is thus safely at ground potential. Figure 8 The surface of the metal sheet insert 9 that is partially exposed towards the internal space 413 in the inner first layer 44 is shown.

[0096] Figure 9 And Figure 10 The control module is shown from the rear side, namely in particular the cover 412 of the module housing 41. In Figure 9 , the view points to the outer second layer, which also forms the outer surface, while in Figure 10 , the view shows the inner first layer 44 (the second layer is hidden in Figure 10 ).

[0097] The cover 412 is irreversibly fixed to the base member 411 by ultrasonic welding. For this purpose, grooves 418 can be provided in the cover 412 (see Figure 6 ), and the peripheral lugs 417 of the base member 411 (see Figure 8 ) are inserted and welded into the grooves.

[0098] The control device 40 is most clearly shown in Figure 11 . The control device 40 is formed by a printed circuit board 401 on which electronic components, in particular one or more microcontrollers (not shown), are arranged. The potting compound 402 is used to stabilize and protect the control device 40 located in the internal space 413 of the first module housing 41. Figure 8Four locating pins 407 are shown, which extend from the first housing module 41 (as an integrally molded part thereof) into the internal space 413 and, during installation, extend through holes (not shown) in the printed circuit board 401 and are thermally plugged into the holes, thereby firmly positioning and supporting the printed circuit board 407 in the internal space 413.

[0099] Figure 6 and Figure 7 and in more detail Figure 14A and Figure 14B The above three stamping grids 8 are shown. The stamping grid has conductor traces that are stamped out from a metal sheet and embedded in a plastic part. The conductor traces contact corresponding connection points on the printed circuit board 401 forming the control device 40. The relative positioning is achieved by dome-shaped positioning pins 85 that engage in corresponding holes formed in the printed circuit board 401 (not shown).

[0100] As Figure 8 and Figure 13 shown, the stamping grids 8 are spatially arranged in respective holes 43 formed in the lower region of the first module housing 41. In the assembled state, the holes 43 in the first module housing 41 and the through holes 27 in the support plate 25 are aligned with each other such that the stamping grids 8 extend through both and are fixed in place.

[0101] As Figure 14A and Figure 14B shown, the stamping grid 8 has conductor traces with connection structures at both ends. The connection structure 81 is for contact-engagement connection structure 39, and the electrical connection with the power switching component 35 is achieved through the engagement connection structure 39. The connection structure 83 is pin-shaped and is fixed (soldered) at the contact points on the printed circuit board 401 using THT technology (through-hole mounting) in the assembled state, that is, connected to the control device.

[0102] Figure 13 Shown on the lower side of the first module housing 41, in addition to the holes 43 for the stamping grids 8 in the region of the four wall reinforcement members 493 in the first module housing 41 (see Figure 12 ), holes 494 for self-tapping fastening screws 28 are respectively provided. The positions of the holes 494 relative to the module housing are shown in Figure 6 and Figure 7 . A seal 492 can also be seen in Figure 13 , which closes at least one through hole 27 or hole 43, thereby protecting the internal space 413 of the first module housing 41 and the internal space of the second module housing 42 containing the power switching component 35 and the heating element 34 from moisture intrusion. For assembly, the fastening screws 28 are inserted through corresponding holes (not shown) in the support plate 25 and screwed intoFigure 13 In the wall reinforcement 493 shown. The seal is placed between the opposing surfaces of the support plate 25 and the first module housing, or is molded into a groove provided in the first module housing and pressed by a fixing device. In particular, the seal can advantageously be directly molded onto the base member 411 by injection molding. In this variant, since there are two different plastics, namely the metal sheet insert and the seal, the base member 411 thus involves at least a four-component material.

[0103] As described above, the disclosure of the German national patent application with document number DE 10 2022 128489.1 filed with the German Patent and Trademark Office on October 27, 2022 is incorporated herein by reference, and the priority of this patent application is claimed herein. Figures 1 to 7 The embodiment of the heating device (hereinafter referred to as the heating device (reference numeral 100)) shown in can also represent an embodiment of the heating device according to the present invention, provided that the control housing of this application is made of plastic material.

[0104] In particular, the control housing (reference numeral 30, Figure 1 and Figures 4 - 7 ) of this application can correspond to the first module housing of this specification. The carrier body (reference numeral 10) of this application can correspond to the support plate of this specification. The control unit (reference numeral 3) of this application can correspond to the control module of this specification. The control printed circuit board (reference numeral 31) of this application (DE 10 2022 128489) can correspond to the printed circuit board of this specification. The heat transfer side 11 and the heating side 12 related to the carrier body or the support plate described in this application (DE 10 2022 128 489) (see Figures 1 to 6 of the priority application) are also shown in this Figure 1 . The cover body (reference numeral 17) described in this application can correspond to the deep-drawn base member 24 of the heat exchanger in this specification. In addition, in the above description of the exemplary embodiment, the stamping grid 8 is shown as a component having conductor traces embedded in a common plastic component. In the priority application (DE102022 128 489), this technical feature is described as conductor traces partially surrounded by a plastic insert, and the stamping grid represents the same object with the same function, as shown in Figure 1 , 2 , 4 and Figures 6 - 7 of the priority application (DE 10 2022 128489).

[0105] List of Reference Numerals

[0106] 1 Electric Heating Device

[0107] 11 Heat transfer side

[0108] 12 Heating side

[0109] 2 Heat exchanger

[0110] 21 Fluid inlet

[0111] 22 Fluid outlet

[0112] 24 Base component, deep-drawn

[0113] 25 Cover component, plate-shaped and flat support plate

[0114] 26 Fluid chamber

[0115] 27 Through hole

[0116] 28 Fastening screw (for control module on support plate)

[0117] 3 Heat conversion unit

[0118] 31 Housing cover

[0119] 32 Attachment element

[0120] 33 Tab

[0121] 34 Heating element

[0122] 35 Power switching component

[0123] 36 Heating conductor track

[0124] 37 Joining connection structure

[0125] 38 Temperature sensor

[0126] 39 Joining connection structure

[0127] 4 Control module

[0128] 40 Control device

[0129] 401 Printed circuit board

[0130] 402 Potting compound

[0131] 407 Locating pin

[0132] 41 First module housing

[0133] 411 Base component

[0134] 412 Cover

[0135] 413 Internal space

[0136] 414 Opening for high-voltage connector part

[0137] 415 Corrugation

[0138] 417 Lug

[0139] 418 Groove

[0140] 419 Pressure balance opening

[0141] 42 Second module housing

[0142] 43 Hole in the first module housing

[0143] 44 First layer of conductive plastic material

[0144] 441 Hole in the first layer

[0145] 442 Exclusion part in the first layer

[0146] 443 Recess for metal ring in the first layer

[0147] 45 Second layer of electrically insulating plastic material

[0148] 491 Gore-tex membrane

[0149] 492 Seal (located between control module and support plate)

[0150] 493 Reinforcement (module housing)

[0151] 494 Threaded hole

[0152] 5 Heat transfer module

[0153] 52 Attachment area (for control module)

[0154] 6 High-voltage connector part

[0155] 7 Low-voltage connector part

[0156] 8 Stamped grid

[0157] 81 Connection structure for control device

[0158] 83 Connection structure for joining connection structure

[0159] 85 Dome-shaped locating pin

[0160] 9 Metal sheet insert

[0161] 91 Metal ring

[0162] 92 First metal wire

[0163] 93 The second metal wire

Claims

1. An electric heating device (1) for a vehicle, in particular an electric or hybrid vehicle, which comprises: - a heating device housing, - at least one heating element (34) configured to perform a heating operation at an operating voltage within a high voltage range; - a heat exchanger (2) thermally connected to the at least one heating element (34) to transfer heat generated by the heating element (34) to a medium flowing through the heat exchanger (2); and - a control module (4) including a control device (40) configured to be able to supply an operating voltage within a high voltage range to the at least one heating element (34) and control the heating operation of the at least one heating element (34); wherein the control module (4) has a first module housing (41) which is part of the heating device housing, the first module housing (41) being formed of plastic and housing the control device (40) therein.

2. The electric heating device (1) according to claim 1, wherein the operating voltage within a high voltage range is 60 V or higher, preferably 400 V or higher, more preferably 700 V or higher, and in particular 800 V or higher.

3. The electric heating device (1) according to claim 1 or 2, wherein the heat exchanger (2) and the at least one heating element (34) form a heat exchanger module (5) and are housed in a second module housing (42); and the first module housing (41) is a component different from the second module housing (42).

4. The electric heating device (1) according to any one of claims 1 - 3, wherein the first module housing (41) has a first layer (44) of a conductive plastic material.

5. The electric heating device (1) according to claim 4, wherein the conductive plastic material is a plastic reinforced with carbon fibers.

6. The electric heating device (1) according to any one of claims 1 - 5, wherein the first module housing (41) has a second layer (45) of an electrically insulating plastic material.

7. The electric heating device (1) according to claim 6, wherein the electrically insulating plastic material is a plastic reinforced with glass fibers.

8. The electric heating device (1) according to any one of claims 6 or 7, and referring back to any one of claims 4 or 5 ， wherein the second layer (45) forms an exposed outer surface of the first module housing on the outside, while the first layer (44) surrounds the inner space (413) of the module housing (413) inside relative to the second layer, wherein preferably, the first layer (44) and the second layer (46) are molded together and form an integral part.

9. The electric heating device (1) according to any one of claims 4 - 8, wherein A high-voltage connector section (6) is formed in the first module housing (41) and is at least partially surrounded by a metal ring (91) connected to the ground potential, wherein the metal ring (91) is embedded in a first layer (44) of conductive plastic material and / or is located between the first layer (44) and the second layer (46), and wherein the metal ring (91) is preferably formed of aluminum, copper, or a steel plate.

10. The electric heating device (1) according to claim 9, wherein, the metal ring (91) is conductively connected to the metal support plate (25) of the heat exchanger module (5) via a first metal conductor (92) embedded in the conductive plastic material of the first layer (44), and / or the metal ring (91) is conductively connected to the ground connection structure of the printed circuit board (401) of the control device (40) via a second metal wire (93) embedded in the conductive plastic material of the first layer (44).

11. The electric heating device (1) according to any one of claims 4 - 10, wherein, a low-voltage connector section (7) is formed in a part (442) of the first module housing, wherein the first layer (44) of conductive plastic material does not extend in the part (442), such that the wall of the first module housing (41) in the region of the part (442) is formed essentially only by the second layer (45) of electrically insulating plastic material.

12. The electric heating device (1) according to any one of the preceding claims, wherein, at least one hole (43) is formed in the first module housing (41) for an electrical connection structure between the control device (40) in the first module housing (41) and a power switching component (35) for switching the heating element (34) in the second module housing (42) to pass through the at least one hole (43), wherein a stamping grid (8) with conductor tracks embedded in a common plastic part is arranged in the at least one hole (43), and wherein the conductor tracks are in contact with corresponding connection points on the printed circuit board (401) forming the control device (40).

13. The electric heating device (1) according to claim 12, wherein, the stamping grid (8) extends through the hole (43) and the through hole (27) into the internal space (413) of the first module housing (41), and in the internal space (413) of the first module housing (41), the stamping grid (8) is fixed to the printed circuit board (401) forming the control device (40) by at least one positioning device, in particular a positioning pin (85).

14. The electric heating device (1) according to claim 12 or 13, wherein, fastening means, in particular one or more screws (415), are provided for fastening the support plate (25) of the heat exchanger module (5) to the first module housing (41), wherein the support plate (25) has a through hole (27) aligned with the at least one hole (43), such that the stamping grid (8) extends through the through hole (27) of the support plate (25) and provides a contact connection structure (81) for the conductor tracks on the opposite sides of the stamping grid (8). Among them, the seal (492) is preferably arranged between the opposing surfaces of the first module housing (41) and the support plate (25), and the seal closes at least one through-hole (27) or hole (43), thereby protecting the internal space (413) of the first module housing (41) and the internal space of the second module housing (42) containing the power switching component (35) and the heating element (34) from moisture intrusion.

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