DE102023111569B4 - Electric heater for a vehicle - Google Patents

Abstract

An electric heater (100) for a vehicle, comprising
- at least two heating modules (101), wherein a heating module (101) comprises at least one heating element (106) arranged between two contact electrodes (107) and electrically insulated from a surrounding tube (109) by insulation (108), wherein heat-transferring elements (110) are mounted on the outer surface of the tube (109),
- an electronics housing (104), wherein the at least two heating modules (101) protrude through at least one opening (115) into the electronics housing (104), and wherein the opening (115) in the electronics housing (104), through which a heating module (101) protrudes, is sealed by a seal (103), and
- at least two conductor elements (102) arranged inside the electronics housing (104), characterized in that
- a first heating module (101a) by a first conductor element (102a) and
- a second heating module (101b) is electrically connected to the electronics housing (104) by a second conductor element (102b).

Description

The invention relates to an electric heater for a vehicle according to the preamble of the independent patent claim. Furthermore, a method for producing the same is claimed according to the preamble of the independent patent claim.

EP 4 243 568 A1 discloses an electric heating device with at least two heating modules and a control housing with power electronics arranged therein, wherein the electrically conductive outer shell of the respective heating module is electrically connected to the bottom of the control housing by an electrical conductor arrangement on a side surface of the outer shell projecting into the interior of the control housing. The electrical conductor arrangement comprises at least one electrically conductive intermediate element and a cover that covers the intermediate element in the direction opposite to the bottom of the control housing. Also disclosed are a method for producing the described heating device and a motor vehicle with the described heating device.

US 2004 / 0 112 884 A1 discloses an electric heating system for motor vehicles with one or more electric heating elements, a control circuit arranged in a housing with one or more power semiconductors mounted on the control circuit for controlling the power radiated by the heating elements, and a metal plate provided as a ground potential, which is arranged on the side of the circuit board facing away from the power semiconductor and is firmly connected to the circuit board and electrically insulated from the conductor tracks located on the underside of the circuit board. One or more heat sinks are provided outside the housing, and the metal plate is connected to the at least one heat sink arranged outside the housing by heat-conducting connectors.

CN 1 03 179 700 A discloses a heat-generating element with a positioning frame forming a receptacle in which at least one PTC element is accommodated, and two contact plates resting on opposite sides of the PTC element, as well as a sheet metal cover for the PTC element connected to the positioning frame. Furthermore, an electric heating device is disclosed, comprising a frame forming an opening on opposite sides for the passage of a medium to be heated, and a layered structure arranged in the frame, comprising layers of corrugated fins and heat-generating elements. The heat-generating element has at least one PTC element arranged between two parallel contact plates and is provided on both sides with a sheet metal cover arranged between the corrugated fin elements and the contact plate.

EP 4 242 547 A1 discloses an electric heating device with at least two heating modules, a control housing, and power electronics arranged therein for the electrical supply of the heating modules, as well as an electrically conductive conductor arrangement with a rail from which an arm protrudes, which electrically connects an electrically conductive outer shell of the respective heating module to the housing. A motor vehicle with such an electric heating device is also disclosed.

KR 10 1 115 952 B1 discloses a power supply structure for an electronic heater having a plurality of flat tubes, wherein a portion of the outer surface of the flat tube protrudes from a frame, and wherein a first wire is connected to the protruding outer surface of each flat tube such that a negative pole can be applied thereto. The flat tube further has a heating means built therein and a heating means connector protruding by a predetermined length, wherein a second wire is connected to the protruding heating means connector such that a positive pole can be applied thereto. An insulating member is arranged on the outer surface of the frame such that the electrical connection positions of the first wire and the second wire are separated by positioning them above and below the insulating member, respectively.

US 2021 / 0 045 194 A1 discloses an electric heating device comprising a housing with a partition wall separating a connection chamber from a heating chamber for dissipating heat, and from which at least one PTC heating element with a heating element housing protrudes toward the heating chamber. At least one PTC element and conductor tracks electrically connected to the PTC element for energizing it with different polarities, which are electrically connected in the connection chamber, are supported in an insulated manner. A holding element encompasses the heating element housing and is connected to the partition wall on its side facing the heating chamber and to the heating element housing. A method for producing such an electric heating device is also disclosed.

US 2005 / 0 205 552 A1 discloses an electric heating device having a plurality of radiating elements, each having a radiating fin and a radiating fin support plate surrounding the radiating fin, which is brazed integrally with the radiating fin, a A plurality of flat tubes arranged between the radiating elements and having heating means therein for generating heat upon supply of electrical energy, as well as first and second support frames arranged opposite one another on the sides of the outermost radiating elements for supporting and fixing the radiating elements and the flat tubes, and first and second caps for supporting the two end portions of the first and second support frames and both end portions of the flat tubes.

EP 1 338 451 A2 discloses an electric air heating device, particularly for a motor vehicle, with electric heating elements for heating the air and a housing having a ground connection, an electrical supply connection, and an electronic circuit for controlling the supply to the heating elements. The heating elements are arranged in the housing in electrical contact with the ground connection and the electrical supply connection. The housing is made of an electrically conductive material and is formed in one piece with the molded-on ground connection. The heating elements and the electronic circuit are arranged in direct electrical contact with the housing.

EP 3 904 781 A1 discloses an electric heating device for heating a fluid, comprising a heating module and a control housing. The heating module has an outer shell made of metal or an alloy and surrounds at least one heating element, and the control housing contains power electronics for the electrical supply of the heating module. According to this application, the control housing has a through-opening through which the heating module is guided and a sealing arrangement arranged in the through-opening, which fluidically seals the power electronics against the fluid and electrically insulates the control housing from the heating module shell.

EP 3 493 650 A1 discloses an electric heating device with a frame in which a power part is arranged, which has corrugated fin elements and heat-generating elements, each comprising at least one PTC element arranged between contact plates, which is covered on the outside by insulation and accommodated in a flat tube, wherein the corrugated fin elements are guided through a control housing in a sealed manner on the outside of the flat tubes on their connection side, and wherein the control housing is provided with a conductor element which electrically connects a plurality of flat tubes to one another.

The present invention addresses the problem of designing the described electric heater in a modular manner, thus allowing it to be flexibly adapted to the requirements of different vehicle applications. At the same time, the problem is also to improve personal safety, in particular by reducing the risk of electrical shock from contact with live components in the event of malfunctions.

The invention relates to an electric heater for a vehicle for heating a fluid, wherein the heater consists of several heating modules, each of which is electrically connected to the vehicle's ground terminal via a conductor element. Furthermore, the invention relates to a method for manufacturing said electric heater.

The invention relates to an electric heater for a vehicle, which has at least two heating modules, wherein each heating module comprises at least one heating element arranged between two contact electrodes and electrically insulated from a surrounding tube by insulation, wherein heat-transfer elements are attached to the outer surface of the tube. In addition, the electric heater has an electronics housing in which power electronics are arranged, wherein the at least two heating modules protrude at least partially into the housing through openings in the housing and at least one opening through which a heating module protrudes is sealed by a seal. Furthermore, the heater has at least two conductor elements arranged inside the housing. According to the invention, at least one heating module is electrically connected to the housing by a conductor element.

An electric heater is used to heat fluids used during the operation of a vehicle, such as air or coolant. For this purpose, heating elements are supplied with an electrical voltage, which heats them up. The heating element can be a ceramic block with a PTC effect or a resistance heating layer applied to an insulating substrate. To ensure efficient heat transfer into the fluid and, at the same time, guarantee operational reliability and durability, the heating elements are housed in heating modules. A heating module comprises at least one heating element arranged between two contact electrodes and electrically insulated from a surrounding tube, such as a flat tube, by insulation. Each contact electrode has at least one terminal lug that protrudes on one side of the tube and serves to supply electrical voltage. At least one heat-transfer element, such as a Corrugated fin around which the fluid flows and which exchanges heat with the fluid. Each tube has an upper and a lower end, each of which can be fluidically sealed, for example by a plug, a gasket, or a component that aligns several tubes with each other and seals them at the same time. The upper end is the end at which the connection lugs of the contact electrodes protrude from the tube. The tube is preferably made of a metallic material, in particular an aluminum alloy, to ensure ideal heat transfer from the heating element to the heat-transfer element. The insulation between the contact electrodes and the tube can be provided by a ceramic plate or a foil, for example, and generally ensures that both the tube and the heat-transfer element are stress-free during operation. However, in the event of a fault, this insulation may not function properly, for example due to damage to the insulation or accidental penetration of the fluid into the pipe, causing the pipe or the heat-transfer element to become live components and, if touched by a person, could lead to an electrical accident.

Furthermore, the electric heater has an electronics housing, which preferably defines an electronics interior in a fluid-tight manner with an electronics housing cover. The electronics housing preferably comprises an electrically conductive material, particularly preferably a metal, for example, aluminum or an aluminum alloy. Alternatively, the electronics housing can also be made of an electrically non-conductive material, for example, a plastic. In this case, the electronics housing is at least partially designed with an electrically conductive coating or another electrical conductor in order to establish the electrical contact according to the invention with the neutral conductor or ground connection of the vehicle. The electronics interior preferably houses line electronics, which serve to control and supply power to the respective heating modules. Alternatively, the power electronics can also be arranged outside the electronics housing. A battery, for example, can serve as a voltage source. The voltage for operating the heater is preferably in the high-voltage range, i.e., above 48 V, particularly preferably above 240 V. To enable electrical contact between the power electronics and the heating modules, the electronics housing also has a number of openings, which preferably correspond to the number of heating modules. The at least two heating modules extend at least partially through the openings into the electronics interior and are electrically connected to the power electronics there. The space between the opening and the heating module is fluidically sealed by a sealing element, for example a silicone seal, to seal the electronics interior from the fluid and the environment. The electronics housing is preferably made of a metallic material that is electrically conductive. To prevent voltage from being applied to the electronics housing in the event of a malfunction, the electronics housing is connected to the neutral conductor or ground connection of the vehicle. This prevents this situation from leading to an electrical accident if a person touches it.

Furthermore, at least two conductor elements are arranged inside the housing according to the invention such that a first heating module is electrically connected to the housing by a first conductor element and a second heating module is electrically connected to the housing by a second conductor element. The number of conductor elements preferably corresponds to the number of heating modules, so that each heating module is electrically connected to the housing by an associated conductor element. The conductor elements can be identical in construction and/or adapted to the geometry of the heating module, the electronics housing or another component. Furthermore, the conductor elements can differ geometrically or in terms of the material used. For functional reasons, the conductor element consists of an electrically conductive material, preferably a metal, for example copper or aluminum. The conductor element is preferably designed as a thin plate, for example as a stamped or pressed part.

The inventive arrangement of heating module and conductor element allows electric heaters for different vehicle applications to be manufactured using the same heating module, without the need to design special conductor elements for each vehicle application. Instead, the number of heating modules can be adjusted depending on the required heating output, with only the electronics housing needing to be adapted to the number of heating modules.

Alternatively, the electronics housing can be made of an electrically non-conductive material, preferably a non-metallic material, such as a plastic. In this case, the electronics housing has an electrically conductive busbar arranged such that the at least two conductor elements are in electrical contact with the busbar instead of the electronics housing itself and are connected to the vehicle's ground connection via the busbar. The busbar can be made of a metallic material and attached to the electronics housing as a separate component or can be bonded or integrally bonded. be connected to the electronics housing, for example by casting or overmolding, or be applied to the electronics housing as a coating.

In a first advantageous embodiment, at least one of the at least two conductor elements has one or more contact lugs. These serve to electrically contact the conductor element with, for example, the housing or the heating module, or also to mechanically fix the conductor element itself. Many embodiments are conceivable here, so that the individual conductor elements can have a different number and design of contact lugs. Preferably, at least one of the at least two conductor elements has at least one module contact lug, with which the conductor element is electrically connected to a heating module. Alternatively or additionally, the conductor element has at least one housing contact lug, with which the conductor element is electrically connected to the electronics housing.

In the alternative embodiment already mentioned, in which the electronics housing is made of an electrically non-conductive material, the housing contact tab is preferably designed in such a way that it electrically contacts the electronics housing at the busbar provided there.

Preferably, the at least one contact lug of a conductor element consists of at least one sheet metal spring, which is tensioned in the installed state and the resulting spring force ensures electrical contact between the conductor element and the adjacent component.

The contact lug is preferably designed as a thin metal strip that comes into contact with the heating module during installation and is thereby elastically bent. Since the bending occurs in the elastic range of the metal strip, the spring force continuously presses the metal strip against the outer surface of the heating module, ensuring electrical contact between the heating module and the conductor element at all times. The contact lug therefore acts like a spring plate. When dimensioning the metal strip, care must be taken to ensure that predominantly plastic deformation does not occur due to bending during the installation process.

Particularly preferably, the at least one contact lug of at least one conductor element is designed such that the spring force vector of the tensioned contact lug is predominantly perpendicular to the surface of the component electrically connected to the conductor element, for example, the outer surface of the heating module or the surface of the electronics housing. This ensures electrical contact between the components even in the event of relative movement.

Particularly preferably, the at least one conductor element is geometrically designed such that it at least partially, preferably predominantly, and particularly preferably completely encompasses the heating module electrically connected to it. This can be achieved, for example, with a rectangular tubular cross-section of the heating module when viewed along the longitudinal axis of the heating module, by an L-, U-, or O-shape of the conductor element.

A conductor element designed in this way offers the advantage that the heating module can be contacted on multiple sides—in the example given here, on two, three, or four sides. Furthermore, this allows a preferred arrangement of multiple contact lugs such that the spring force vectors of multiple contact lugs of a conductor element meet at a single point, thereby stabilizing the conductor element's position relative to the heating module.

In a preferred embodiment of the electric heater, the at least two conductor elements are connected to one another by an electrically non-conductive element. Preferably, the non-conductive element is mechanically connected to another component of the electric heater, for example, the electronics housing. The mechanical connection to the other component can be made, for example, by a screw, rivet, clip, press, or other form-fitting or force-fitting connection. The non-conductive element can serve, among other things, to secure the position of the conductor elements relative to one another or within the electronics housing and/or to maintain the deflection of the contact lugs and thus the electrical contact. Furthermore, the non-conductive element can also fulfill a sealing function for other components. Preferably, the non-conductive element consists of a non-conductive material, preferably a non-metallic material, for example a plastic.

Particularly preferably, the connection between the non-conductive element and the at least two conductive elements is implemented as a material-to-material connection, for example, by overmolding or embedding the conductive elements in the non-conductive element. In this embodiment, the non-conductive element can serve as an assembly aid, since the conductive elements are pre-positioned relative to the non-conductive element and can be installed as a single component in the housing.

In a further preferred embodiment, the electric heater has a cover element arranged in the electronics housing such that it at least partially covers at least one heating module projecting into the housing toward a power electronics unit. Preferably, the cover element provides a fluid-tight seal for the upper end of the heating module tube projecting into the electronics housing, with corresponding openings for the contact electrodes of the heating modules toward the power electronics unit being provided to establish electrical contact between the components. Particularly preferably, the cover element is mechanically connected to the electronics housing, for example, by a screw or clip connection. Furthermore, the cover element can also serve as a positioning aid for the at least two heating modules relative to one another and/or the at least two conductor elements relative to one another and/or the at least two heating modules and the at least two conductor elements relative to one another during the manufacturing process. Preferably, the cover element is designed such that the power electronics unit touches the cover element or is at least partially supported thereon. The cover element is preferably made of an electrically non-conductive material, preferably a non-metallic material, for example, plastic.

In an alternative embodiment, the electronics housing is made of an electrically non-conductive material. Instead of or in addition to the previously described embodiment, in which the electronics housing has an electrically conductive busbar, the cover element can be made entirely or partially of an electrically conductive material, for example, a metallic material, and be electrically connected to the neutral conductor or ground connection of the vehicle. Alternatively or additionally, the cover element can have a busbar made of an electrically conductive material, preferably a metallic material. In this alternative embodiment, the at least two conductor elements are arranged such that the at least first and second heating modules are each electrically connected to the electrically conductive region of the cover element or the busbar of the cover element, respectively, by the at least first and second conductor modules instead of the electronics housing. As already described above, the busbar of the cover element can also be attached to the cover element as a separate component or be positively or materially connected to the cover element, for example, by casting or overmolding, or applied to the cover element as a coating.

In a particularly preferred embodiment of the electric heater, at least one conductor element is mechanically connected to the cover element via at least one holding element. The holding element is preferably a part of the conductor element, for example as a bent sheet metal element, and is shaped at the end such that a connection to the cover element can be established, for example by means of a hook, clip, or shield shape and a corresponding counter-shape for fastening to the cover element. Alternatively, a clip or clamp connection can also be used, for example. The cover element is particularly preferably used as an assembly aid for the at least two conductor elements in such a way that the conductor elements are first connected to the cover element and then the assembly is introduced into the housing interior.

In a further preferred embodiment of the heater, the cover element has at least one spacer element, which, in the installed state, is arranged between the cover element and at least one conductor element. The spacer element is preferably part of the cover element. Alternatively or additionally, the spacer element is arranged such that it presses the at least one conductor element against the electronics housing and/or against the heating module electrically connected to it. This can improve the electrical contact between the conductor element and the components electrically connected to it. Furthermore, the position of the conductor element can be secured.

• - Das Bereitstellen zumindest zweier Heizmodule, wobei ein Heizmodul aus zumindest einem Heizelement besteht, welches zwischen zwei Kontaktelektroden angeordnet ist und durch eine Isolierung von einem darin untergebrachten und es umgebenden Rohr elektrisch isoliert ist, sowie zumindest einem auf der Außenseite des Rohres angebrachten wärmeübertragenden Elements.
• - Das Ausrichten der zumindest zwei Heizmodule zu einem Elektronikgehäuse, wobei die Heizmodule durch zumindest eine Öffnung in den Innenraum des Elektronikgehäuses ragen.
• - Das Anbringen zumindest einer Dichtung in den Raum zwischen dem Elektronikgehäuse und der Außenseite zumindest einem durch diese Öffnung ragenden Heizmoduls.
• - Das Ausrichten und Einbringen zumindest eines ersten Leiterelements gegenüber dem ersten Heizmodul und zumindest eines zweiten Leiterelements gegenüber dem zweiten Heizmodul derart, dass das erste Heizmodul durch das erste Leiterelement und das zweite Heizmodul durch das zweite Leiterelement elektrisch mit dem Elektronikgehäuse verbunden sind.

Also claimed is a method for producing an electric heater for a vehicle, which comprises at least, but not exclusively, the following steps:

• - The provision of at least two heating modules, wherein a heating module consists of at least one heating element which is arranged between two contact electrodes and is electrically insulated by insulation from a tube accommodated therein and surrounding it, and at least one heat-transferring element attached to the outside of the tube.
• - Aligning the at least two heating modules to an electronics housing, wherein the heating modules protrude through at least one opening into the interior of the electronics housing.
• - The installation of at least one seal in the space between the electronics housing and the outside of at least one heating module protruding through this opening.
• - Aligning and inserting at least one first conductor element relative to the first heating module and at least one second conductor element relative to the second heating module such that the first heating module is electrically connected to the electronics housing by the first conductor element and the second heating module is electrically connected to the electronics housing by the second conductor element.

It is understood that the order of the steps may be varied if necessary.

• - Die Herstellung einer mechanischen Verbindung zwischen den zumindest zwei Leiterelementen und einem Abdeckungselement.
• - Das Einbringen des Abdeckungselements mit den vormontierten Leiterelementen in das Elektronikgehäuse derart, dass ein erstes Heizmodul durch ein erstes Leiterelement und ein zweites Heizmodul durch ein zweites Leiterelement jeweils elektrisch mit dem Elektronikgehäuse verbunden sind.

Alternatively, the manufacturing step of aligning and inserting the at least two conductor elements can be replaced by the following two steps:

• - The creation of a mechanical connection between the at least two conductor elements and a cover element.
• - Inserting the cover element with the pre-assembled conductor elements into the electronics housing in such a way that a first heating module is electrically connected to the electronics housing by a first conductor element and a second heating module is electrically connected to the electronics housing by a second conductor element.

In a further alternative embodiment of the manufacturing method, the method comprises a further manufacturing step in which the at least two conductor elements are connected by an electrically non-conductive element prior to installation, for example, by overmolding or casting. In this case, instead of aligning and inserting the at least two conductor elements relative to the heating modules, the non-conductive element to which the at least two conductor elements are connected is aligned and inserted relative to the two heating modules, so that they are electrically connected to the electronics housing via the respective conductor elements.

• 1 eine schematische Darstellung der Hauptkomponenten des Heizers, die elektrisch miteinander verbunden sind,
• 2 den schematischen Querschnitt eines Heizmoduls für einen elektrischen Heizer,
• 3 eine schematischen Querschnittsansicht des Elektronikgehäuses, des Heizmoduls und des Leiterelements,
• 4 drei beispielhafte schematische Querschnitte (a, b, c) der Anordnung eines Leiterelements relativ zu einem Heizmodul,
• 5 den schematischen Querschnitt eines Leiterelements vor (5a) und nach (5b) dem Einbau des Leiterelements in den elektrischen Heizer,
• 6 den schematischen Querschnitt eines Leiterelements und den Ausschnitt eines Abdeckelements,
• 7 ausschnittsweise einige Bauteile einer beispielhaften Ausführungsform eines elektrischen Heizers.

Further details and advantages of the present invention will become apparent from the following description of exemplary embodiments in conjunction with the drawings. These show:

• 1 a schematic representation of the main components of the heater that are electrically connected to each other,
• 2 the schematic cross-section of a heating module for an electric heater,
• 3 a schematic cross-sectional view of the electronics housing, the heating module and the conductor element,
• 4 three exemplary schematic cross-sections (a, b, c) of the arrangement of a conductor element relative to a heating module,
• 5 the schematic cross-section of a conductor element before (5a) and after (5b) the installation of the conductor element in the electric heater,
• 6 the schematic cross-section of a conductor element and the section of a cover element,
• 7 Detail of some components of an exemplary embodiment of an electric heater.

1 shows a schematic representation of the electrically interconnected main components of an electric heater (100). The heating modules (101, 101a, 101b) can be seen, each of which is mechanically and fluid-tightly connected to the electronics housing (104) via a seal (103). In order to prevent the electronics housing from being exposed to electrical voltage in the event of a fault, a permanent connection is made to the neutral conductor or the ground connection of the vehicle (105). However, due to the electrically insulating effect of the seal (103), the heating modules (101, 101a, 101b) are not protected, meaning that the applied voltage cannot be dissipated in the event of a fault. The conductor elements (102, 102a, 102b) are therefore provided to establish an electrical connection between the respective heating module (101a, 101b) and the electronics housing (104). According to the invention, at least a first heating module (101a) is electrically connected to the electronics housing (104) and consequently also to the ground connection of the vehicle (105) by a first conductor element (102a), and a second heating module (101b) is electrically connected to the electronics housing (104) by a second conductor element (102b). It is understood that designs with more than two heating modules are also conceivable, with the number of conductor elements preferably corresponding to the number of heating modules.

2 shows a schematic cross-section through a heating module (101) for an electric heater (100), comprising a heating element (106), which in the exemplary embodiment is designed as a cuboid-shaped PTC block. The heating element (106) is electrically connected on two opposite sides to contact electrodes (107), which ensure the voltage supply to the heating element. The connected insulation (108), shown here as ceramic insulation plates, provides electrical insulation from the tube (109), shown here as a flat tube. Also shown are the heat-transfer elements (110), which are attached to the outside of the tube and are in heat-transferring contact with the fluid flowing around them.

3 shows the schematic cross-section of an embodiment of the electric heater (100). A heating module (101) can be seen, which projects through an opening (115) in the electronics housing (104) partially into the electronics interior (113), which is delimited by the electronics housing (104) and the electronics housing cover (114). The seal (103) ensures a fluid-tight closure of the opening (115) between the heating module (101) and the electronics housing (104). Also visible are the heating module connections (111), which electrically contact the heating module (101) with power electronics (112). Elements for controlling and supplying power to the heating modules (101) are attached to the power electronics (112), not shown here. The conductor element (102) according to the invention encloses the heating module (101) on two sides in the illustrated embodiment. The contact lugs (116) of the conductor element (102) are visible, whereby the module contact lug (117) electrically connects the heating module (101) to the conductor element (102) and the housing contact lug (118) electrically connects the conductor element (102) to the electronics housing (104). Furthermore, the 3 a cover element (119) which is arranged in the interior electronics space (113) and covers the heating module (101) from the interior electronics space (113), wherein recesses are provided in the cover element (119) which allow an electrical connection between the heating module connections (111) and the power electronics (112). The cover element (119) rests on a support surface (120) of the electronics housing (104), which can serve to support and/or fasten, for example by gluing or screwing, the cover element (119) within the interior electronics space (113). In the illustrated embodiment, the cover element (119) also has a support surface (121) for the power electronics (112), which can serve to support and/or fasten, for example by gluing or screwing, the power electronics (112) within the interior electronics space (113). In order to secure the conductor element (102) in its position and/or to ensure electrical contact, 3 also a spacer element (122), which in the illustrated embodiment is designed as part of the cover element (119), but can also be connected to the cover element (119) as a separate component.

4a to 4c schematically show various embodiments of the conductor element (102) which encloses a heating module (101) with a square cross-section, each viewed as a cross-section in the direction along the heating module. In 4a the conductor element (102) is designed in an L-shape, wherein the module contact lugs (117) contact the heating module (101) on two connected outer sides. In 4b the conductor element (102) has a C- or U-shape and encloses the heating module (101) on three outer sides, wherein the module contact lugs (117) electrically connect the heating module (101) to the conductor element (102) on these outer sides. 4c Finally, the heating module (101) is completely enclosed by the conductor element (102), which is designed in an O-shape. In the exemplary embodiment shown, four module contact lugs (117) are shown, each module contact lug (117) electrically connecting an outer side of the heating module (101) to the conductor element (102). However, designs are also conceivable in which more or fewer than the four module contact lugs (117) shown are provided and which, for example, only establish the electrical connection to two opposite outer surfaces of the heating module (101). The arrangement of the housing contact lugs (118) - both in terms of number and arrangement relative to the conductor element (102) - is also to be regarded as an exemplary embodiment, and the multitude of possible further variations cannot be exhaustively presented here.

5a and 5b show schematically the cross-section of a conductor element (102) and in particular the area of the contact lugs (116) in the removed ( 5a) and in the built-in ( 5b) State, whereby in the illustrated embodiment the area around the module contact lug (117) is shown. In the installed state according to 5b The contact lug (116) is moved from a neutral position ( 5a) bent or deflected by the angle α (123). The strength of the deflection is determined by appropriate dimensioning of the contact lug (116) such that it lies within the elastic range of the material. The deflection creates a restoring force or spring force F _F (124), which acts in the direction of the surface against which the contact lug (116) rests. In the embodiment in 5b the module contact lug (117) is shown in the installed state, which rests on the outer surface of a heating module (101), wherein the spring force F _F (124) acts perpendicular to the outer surface of the heating module (101).

6 schematically shows a conductor element (102) which is fastened to the cover element (119) by a holding element (125). In the embodiment shown, the holding element (125) has the shape of a hook which is guided through an opening in the cover element (119) and establishes a mechanical connection to the cover element (119) at the upper, hook-shaped end. Preferably, the conductor element (102) is fastened to the cover element at at least two, particularly preferably four, points by a holding element (125). element (119) to ensure stable positioning. In addition to the hook shape of the retaining element (125) shown in the exemplary embodiment, other shapes are also possible, for example, a clamp, wedge, or umbrella shape.

7 shows a detail of some components of an embodiment of an electric heater (100), in which six openings (113) are provided in the electronics housing (104) for six heating modules (101) - not shown. The six conductor elements (102) are O-shaped so that in the final state they completely enclose the heating modules (101). Each conductor element (102) is equipped with four module contact lugs (117) and two housing contact lugs (118) in order to establish electrical contact with the respective component. Furthermore, each conductor element (102) has two holding elements (125) which are attached to diagonally opposite sides of the conductor element (102). The cover element (119) is shown offset for the sake of clarity in order to make the conductor elements (102) visible.

List of reference symbols

100

Electric heater

101

Heating module

101a

Heating module 1

101b

Heating module 2

102

Ladder element

102a

Ladder element 1

102b

Ladder element 2

103

seal

104

Electronics housing

105

Neutral conductor or ground connection of the vehicle

106

heating element

107

Contact electrode

108

insulation

109

Pipe

110

Heat transfer element

111

Heating module connection

112

Power electronics

113

Electronics interior

114

Electronics housing cover

115

Opening in the electronics housing

116

Contact flag

117

Module contact tab

118

Housing contact tab

119

Cover element

120

Support surface on the electronics housing for cover element

121

Support surface on the cover element for power electronics

122

Spacer element

123

Deflection angle α

124

Spring force F _F

125

Holding element

Claims (10)

An electric heater (100) for a vehicle, comprising - at least two heating modules (101), wherein a heating module (101) comprises at least one heating element (106) arranged between two contact electrodes (107) and electrically insulated from a surrounding tube (109) by insulation (108), wherein heat-transferring elements (110) are mounted on the outer surface of the tube (109), - an electronics housing (104), wherein the at least two heating modules (101) protrude into the electronics housing (104) through at least one opening (115), and wherein the opening (115) in the electronics housing (104), through which a heating module (101) protrudes, is sealed by a seal (103), and - at least two conductor elements (102) arranged in the interior of the electronics housing (104), characterized in that - a first heating module (101a) is connected by a first conductor element (102a) and - a second heating module (101b) are electrically connected to the electronics housing (104) by a second conductor element (102b). Stoker (100) to Claim 1 characterized in that at least one of the at least two conductor elements (102) has at least one contact lug (116), wherein the contact lug (116) - is designed as a module contact lug (117) with which the conductor element (102) is electrically connected to a heating module (101) and/or - is designed as a housing contact lug (118) with which the conductor element (102) is electrically connected to the electronics housing (104). Stoker (100) to Claim 2 characterized in that the contact lug (116) consists of at least one sheet metal spring, which is tensioned in the installed state and thereby forms an electrical mechanical contact with the adjacent component (101, 104). Stoker (100) to Claim 3 characterized in that the vector of the spring force (124) of the tensioned module contact lug (117) is predominantly perpendicular to the surface of the heating module (101) electrically connected to the conductor element (102). Heater (100) according to one of the preceding claims, characterized in that at least one of the two conductor elements (102) is geometrically designed such that it at least partially encompasses the heating module (101) electrically connected to it. Heater (100) according to one of the preceding claims, characterized in that the at least two conductor elements (102) are connected to one another by an electrically non-conductive element. Heater (100) according to one of the preceding claims, comprising power electronics (112) and a cover element (119) which at least partially covers at least one heating module (101) projecting into the electronics housing (104) towards the power electronics (112). Stoker (100) to Claim 7 characterized in that at least one of the two conductor elements (102) is mechanically connected to the cover element (119) via a holding element (125). Stoker (100) to Claim 7 characterized in that the cover element (119) has at least one spacer element (122) which, in the installed state, is arranged between the cover element (119) and the conductor element (102). A method for producing an electric heater (100), comprising the following steps: - Providing at least two heating modules (101a, 101b), each comprising at least one heating element (106) arranged between two contact electrodes (107) and electrically insulated from a surrounding tube (109) by insulation (108), with heat-transfer elements (110) arranged on the outside of the tube, - Aligning the at least two heating modules (101a, 101b) with an electronics housing (104), with the heating modules (101a, 101b) protruding at least partially through at least one opening (115) of the electronics housing (104), - Attaching at least one seal (103) into the opening (115) between the electronics housing (104) and at least one of the two heating modules (101), which protrude through the opening (113), - Aligning and inserting at least one first conductor element (102a) opposite the first heating module (101a) and one second conductor element (102b) opposite the second heating module (101b) such that the first heating module (101a) is electrically connected to the electronics housing (104) by the first conductor element (102a) and the second heating module (101b) is electrically connected to the electronics housing (104) by the second conductor element (102b).