DE102023111558B4 - Electric heater for a vehicle - Google Patents

Abstract

An electric heater (100) for a vehicle, comprising
- at least one heating module (101), wherein the 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 (102), wherein the heating module (101) projects through at least one opening (112) into the electronics housing (102) and wherein the opening (112) is sealed by at least one seal (111), and
- at least one conductor element (103) which is arranged in the interior of the electronics housing (102) and electrically connects the heating module (101) to the electronics housing (102), characterized in that the conductor element (103) electrically contacts the heating module (101) at an end face (104).

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 improving the safety of persons during operation of the described electric heater, particularly with regard to reducing the risk of electrical shock from contact with live components in the event of malfunctions. Specifically, the invention addresses the problem of ensuring reliable contact despite thermal expansion of the heating components. At the same time, the problem lies in the modular design and adaptability of the heater to the requirements of different vehicle applications.

The invention relates to an electric heater for a vehicle for heating a fluid, which has at least one fluid-carrying element which is in heat exchange with the fluid.

The invention relates to an electric heater for a vehicle, which has at least one heating module, wherein the heating module comprises at least one heating element which is arranged between two contact electrodes and is electrically insulated from a surrounding tube by insulation, wherein heat-transferring elements are attached to the outer surface of the tube. Furthermore, the electric heater has an electronics housing, wherein the heating module projects through at least one opening into the electronics housing and wherein the opening is sealed by at least one seal. In addition, the heater has at least one conductor element which is arranged inside the electronics housing and electrically connects the heating module to the electronics housing, wherein the conductor element, according to the invention, makes electrical contact with the heating module on an end face of the tube.

An electric heater is used to heat fluids that must be tempered during vehicle operation, such as air for the driver's cab or coolant. For this purpose, heating elements are supplied with an electrical voltage, which heats them up. The heating element can, for example, be designed as a ceramic with a PTC effect or as 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 that is arranged between two contact electrodes and is 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. On the outside of the tube, at least one heat-transferring Element is attached, for example 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 seal 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. Each end has an end surface that is predominantly aligned in the longitudinal direction of the tube. In contrast, the outer surface is defined such that it is predominantly orthogonal to the longitudinal axis of the tube. The tube is preferably made of a metallic material, in particular an aluminum alloy, in order 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, for example, by a ceramic plate or a foil 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 comprises 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, such as a plastic. In this case, the electronics housing is at least partially coated with an electrically conductive coating or another electrical conductor to establish the electrical contact according to the invention with the neutral conductor or ground connection of the vehicle.

The electronics compartment can house components that serve to control and supply power to the respective heating modules, such as a line electronics or a busbar. A battery, for example, can serve as a power source. The voltage for operating the heater is preferably in the high-voltage range, i.e., above 48V, particularly preferably above 240V.

To enable electrical contact between the power electronics and the heating modules, the electronics housing additionally has a number of openings, which preferably correspond to the number of heating modules. At least one heating module protrudes at least partially through the opening into the electronics interior and is electrically connected there to the power electronics via the connection tabs of the contact electrodes. The space between the opening and the heating module is fluidically sealed by a sealing element, for example a silicone seal, in order 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 electric shock if a person comes into contact with it.

In addition, the electric heater has at least one conductor element that electrically connects the heating module to the electronics housing and consequently to the neutral conductor or ground connection of the vehicle. According to the invention, the conductor element makes contact with the heating module at an end face of the heating module, preferably at the end face of the tube, particularly preferably at the upper end of the tube. For this purpose, the conductor element is preferably arranged in the interior of the electronics. The electrical contact can be established by point, line, or surface contact between the conductor element and the heating module or the conductor element and the electronics housing. Due to its function, the conductor element at least partially comprises an electrically conductive material, preferably a metal, for example copper or aluminum. The location at which the conductor element is in electrical contact with the respective component, i.e., the heating module or the electronics housing, is also referred to below as the "contact surface," whereby point and line contacts are also included.

In an alternative embodiment, the electronics housing may 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 conductor element is in electrical contact with the busbar instead of the electronics housing itself and is connected to the ground terminal of the vehicle through the busbar. The busbar can be made of a metallic material and attached to the electronics housing as a separate component or be connected to the electronics housing in a form-fitting or material-locking manner, for example by casting or overmolding, or be applied to the electronics housing as a coating.

In a first advantageous embodiment, the conductor element is arranged completely above the heating module, viewed in the longitudinal direction of the tube. "Above" is defined as the area that follows the upper end of the heating module or tube, viewed in the longitudinal direction of the heating module, and can also extend orthogonally beyond the projected or continued outer geometry of the heating module or tube.

In a further advantageous embodiment, the conductor element is designed as a single piece with the electronics housing or as a single piece with the heating module. In this case, the connection between the conductor element and the corresponding component can be achieved, for example, by a positive-locking and/or material-to-material connection. The electrical connection between the conductor element and the corresponding component can be made either as a single-piece connection or via a contact element which, as part of the conductor element, is connected to an electrically conductive area of the corresponding component. A positive-locking connection can be realized, for example, by a screw, clip, or plug connection; a material-to-material connection can be achieved, for example, by gluing, welding, or overmolding/encapsulating the conductor element.

Preferably, the conductor element is electrically connected only to an adjacent or assigned heating module. Preferably, the number of conductor elements corresponds to the number of heating modules, allowing a corresponding conductor element to be assigned to each heating module, so that in a heater with a plurality of heating modules, a preferably equivalent plurality of conductor elements is used. The heating module that is the closest spatial distance to the conductor element is considered to be the adjacent heating module. This embodiment allows a modular design of the heater, since a uniquely constructed heating module and conductor element design can be used multiple times. Thus, different performance requirements of different vehicle applications can be met simply by varying the number of heating modules, meaning only the electronics housing needs to be redesigned. Such a strategy of using identical components allows for cost-effective and efficient production of the components as well as simpler assembly of the heater itself.

The conductor elements can be identical in design and/or adapted to the geometry of the heating module, the electronics housing, or another component, depending on the respective installation position. Furthermore, the conductor elements can differ in terms of geometry or the material used.

In an alternative embodiment, at least two conductor elements are connected to one another by a non-conductive element. Preferably, the non-conductive element is mechanically connected to another component of the electric heater, for example, the electronics housing. This mechanical connection 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. 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.

In a particularly preferred embodiment, the conductor element has at least one spring element which is tensioned in the installed state and ensures electrical contact between the conductor element and the adjacent component through the resulting spring force.

The spring element can be at least partially involved in establishing the electrical connection between the heating module and the electronics housing. In this case, the spring element comprises an electrically conductive material. However, designs are also conceivable in which the spring element merely presses an electrically conductive material onto the contact surfaces of the heating module and the electronics housing, ensuring a force-locking contact by applying the spring force.

Preferably, the spring element is designed such that a stronger insertion of the heating module into the housing leads to an additional deflection or tension of the spring. The spring element is particularly preferably designed as a torsion spring or leg spring, alternatively also as a spiral spring or torsion spring. In this case, the two contact surfaces are connected via at least two legs to a spirally arranged rotation spring or torsion bar. A deflection thus leads to a change in the angle between between the legs, which leads to an increase or reduction of the spring force depending on the direction. In the

Particularly preferably, the direction of the spring force vector in the aforementioned embodiment corresponds predominantly to the longitudinal axis of the tube of the heating module. As a result, a change in the length of the heating module, which arises, for example, from thermal deformation of the tube, only leads to an increase in the spring force and thus has no negative impact on the quality of the electrical connection between the conductor element and the heating module. Such a design therefore ensures electrical contact between the heating module and the ground connection or neutral conductor of the vehicle even in the event of thermal deformation of the heating module during operation. In general, thermal deformation of the tube can, of course, lead to a slight displacement of the contact surface along the end face of the tube.

In a further preferred embodiment, the electric heater additionally comprises a cover element, which is arranged in the electronics housing such that it delimits the heating module from the conductor track. Preferably, the cover element also provides a fluid-tight seal for the upper end of the tube, with corresponding openings for the contact electrodes or the connecting lugs of the contact electrodes of the heating module toward the power electronics being provided to enable electrical contact between the contact electrodes and the power electronics. 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 a plurality of heating modules relative to one another and/or a plurality of conductor elements relative to one another and/or a plurality of heating modules and a plurality of conductor elements relative to one another during the manufacturing process. Preferably, the cover element is designed such that the power electronics 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 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 conductor element is arranged such that the heating module is connected by the conductor element to the electrically conductive region of the cover element or the busbar of the cover element 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 connected to the cover element in a form-fitting or material-fitting manner, for example by casting or overmolding, or applied to the cover element as a coating.

In a particularly preferred embodiment of the electric heater, the conductor element is mechanically connected to the cover element. This mechanical connection can be made either by a form-fitting connection, for example by means of correspondingly matching geometries on the conductor element and cover element, such as a hook or shield shape and the corresponding opening, or by means of a screw, clip, or clamp connection. A one-piece design is also conceivable; for example, an adhesive or welded connection or the embedding of the conductor element in the cover element by overmolding could be considered. The cover element is particularly preferably used as an assembly aid for the conductor element in such a way that the conductor element is first connected to the cover element and then the assembly is introduced into the housing interior.

• - Das Bereitstellen zumindest eines Heizmoduls, wobei das 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 des Heizmodules zu einem Elektronikgehäuse, wobei das Heizmodul durch eine Öffnung in den Innenraum des Elektronikgehäuses ragt.
• - Das Anbringen zumindest einer Dichtung in den Raum zwischen dem Elektronikgehäuse und der Außenseite des durch diese Öffnung ragenden Heizmoduls.
• - Das Ausrichten und Einbringen zumindest eines Leiterelements gegenüber dem Heizmodul derart, dass das Leiterelement das Heizmodul an der Stirnseite des Heizmoduls bzw. des Rohres elektrisch kontaktiert und somit eine elektrische Verbindung zum Elektronikgehäuse herstellt.

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

• - Providing at least one heating module, wherein the 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 mounted on the outside of the tube.
• - Aligning the heating module to an electronics housing, whereby the heating module protrudes through an 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 the heating module protruding through this opening.
• - Aligning and inserting at least one conductor element relative to the heating module in such a way that the conductor element electrically contacts the heating module at the front side of the heating module or the tube and thus establishes an electrical connection to the electronics housing.

• - Die Herstellung einer mechanischen Verbindung zwischen dem Leiterelement und einem Abdeckungselement.
• - Das Einbringen des Abdeckungselements mit dem vormontierten Leiterelement in das Elektronikgehäuse derart, dass das Leiterelement das Heizmodul an der Stirnseite des Rohres elektrisch kontaktiert und somit eine elektrische Verbindung zum Elektronikgehäuse herstellt.

It is understood that the sequence of steps can be varied if necessary. Alternatively, the manufacturing step of aligning and inserting the conductor element can be replaced by the following two steps:

• - The creation of a mechanical connection between the conductor element and a cover element.
• - Inserting the cover element with the pre-assembled conductor element into the electronics housing in such a way that the conductor element electrically contacts the heating module on the front side of the tube and thus establishes an electrical connection to the electronics housing.

In a further alternative embodiment, the manufacturing method comprises a further step in which 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, at least a second heating module of identical design must be provided. Furthermore, instead of aligning and inserting the conductor elements relative to the at least two heating modules, the non-conductive element to which the at least two conductor elements are connected is aligned and inserted relative to the heating modules, so that the heating modules are electrically connected to the electronics housing via the respective conductor elements.

• 1 eine Darstellung der Hauptkomponenten des Heizers, die elektrisch miteinander verbunden sind,
• 2 den Querschnitt eines Heizmoduls für den elektrischen Heizer,
• 3 die Schnittansicht einer vereinfachten Ausführungsform des Heizers,
• 4 drei beispielhafte Ausführungsformen für die Befestigung des Leiterelements,
• 5 die Auswirkung der thermischen Ausdehnung des Heizmoduls bei gegenüberliegenden Kontaktseiten,
• 6 die Auswirkung der thermischen Ausdehnung des Heizmoduls bei nicht gegenüberliegenden Kontaktseiten,
• 7 den vereinfachten Querschnitt des Elektronikgehäuses des Heizmoduls und des Leiterelements einer beispielhaften Ausführungsform des Heizers.

Further details and advantages of the present invention will become apparent from the following description of exemplary embodiments in conjunction with the drawings, each of which schematically shows:

• 1 a representation of the main components of the heater that are electrically connected to each other,
• 2 the cross-section of a heating module for the electric heater,
• 3 the sectional view of a simplified embodiment of the heater,
• 4 three exemplary embodiments for the fastening of the ladder element,
• 5 the effect of thermal expansion of the heating module on opposite contact sides,
• 6 the effect of thermal expansion of the heating module when the contact sides are not opposite each other,
• 7 the simplified cross-section of the electronics housing of the heating module and the conductor element of an exemplary embodiment of the heater.

1 shows a schematic representation of the main components of an electric heater (100), which are electrically connected to one another. In particular, a heating module (101) and the electronics housing (102), which is connected to the neutral conductor or ground connection of the vehicle, can be seen. The conductor element (103) electrically connects the heating module (101) to the electronics housing (102), wherein the contact between the heating module (101) and the conductor element (103) occurs at the end face (104) of the heating module (101). Also visible is the main direction of thermal expansion (105) of the heating module (101). This indicates the direction in which the heating module (101) predominantly expands as a result of the heating of the heating elements (106), which are not visible in this view. In order to compensate for this thermal expansion, the conductor element (103) is designed as a spring element.

2 shows a schematic cross-section through a heating module (101) for an electric heater (100), comprising a heating element (106), which in the illustrated 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 (106). 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 (109) and are in heat-transferring contact with the fluid flowing around them.

3 shows a simplified sectional view of a portion of the electronics housing (102). An opening (112) in the electronics housing (102) is visible, through which a heating module (101) partially protrudes into the electronics housing (102). The space in the opening between the heating module (101) and the electronics housing (102) is filled by a seal (111) and ensures a fluid-tight seal. Furthermore, the conductor element (103) is visible, which electrically connects the heating module (101) and the electronics housing (102), wherein The electrical contact between the heating module (101) and the conductor element (103) is made at the end face (104) of the heating module (101). In order to compensate for thermal expansion along the main direction (105) of the heating module (101), the conductor element (103) in this illustration is designed as a torsion spring, which is in electrical contact with the two bodies via two legs.

4 shows schematically three exemplary embodiments ( 4a , 4b , 4c ) for the fastening or the location of the fastening (113) of the conductor element (103), which is shown as a torsion spring with two legs. In the first exemplary embodiment 4a The conductor element (103) is connected to the heating module (101) in a predominantly rotatable manner, for example by a pin or clip connection, thereby preventing relative movement between the conductor element (103) and the heating module (101). Compensation for thermal expansion in the main direction (105) is thus achieved by deflecting the leg that electrically connects the conductor element (103) to the electronics housing (102). In the second exemplary embodiment, 4b The conductor element (103) is connected to the electronics housing (102) in a predominantly rotatable manner, for example by a pin or plug connection. This prevents relative movements between the conductor element (103) and the electronics housing (102). Compensation for thermal expansion in the main direction (105) is thus achieved by deflecting the leg that electrically connects the conductor element (103) to the heating module (101). In the third embodiment 4c The conductor element (103) is mounted on a predominantly floating, rotatable support, allowing the conductor element (103) to move relative to both the heating module (101) and the electronics housing (102), while being secured against accidental falling out. This can be achieved, for example, by two delimiting guide walls or a guide rail, which can be located either on the heating module (101) or on the electronics housing (102) or on a third component, and the conductor element (103) is simply inserted or clipped in.

5 shows a schematic of the effect of thermal expansion of the heating module along the main direction (105) of the heating module (101) when the contact sides are predominantly opposite one another. Opposite contact sides occur when the front side (104) of the heating module is oriented predominantly parallel to the contact side of the electronics housing (102), i.e. the side on which the conductor element (103) is in electrical contact with the electronics housing (102). The cold (left) and warm (right) states of the heating module (101) can be seen, as well as the resulting distances d ₁ and d ₂ between the front side (104) and the contact side of the heating module (101). As the heating module (101) heats up, the distance d ₁ in the cold state (left) is reduced by the difference Δd compared to the distance d ₂ in the warm state (right).

6 shows schematically the effect of the thermal expansion of the heating module (101) along the main direction (105) of the heating module (101) with predominantly non-opposing contact sides. In contrast to 5 The contact side of the electronics housing (102) is not parallel to the end face (104) of the heating module (101). In the example shown, the orientation is almost orthogonal, although other alignments are also conceivable. The electronics housing (102) and a conductor element (103) can be seen, which in the example shown is again designed as a torsion spring and is rotatably connected to the electronics housing (102), thereby preventing relative movements between the conductor element (103) and the electronics housing (102). The conductor element (103) has two legs, with which it is each in electrical contact with the electronics housing (102) and the end face (104) of the heating module (101). Both legs enclose an angle α. Furthermore, a simplified cross-section of the heating module (101) can be seen, which shows the tube (109) and the two connection lugs (114) of the heating module (101). Furthermore, a difference Δd can be seen, which is caused by the thermal expansion along the main direction (105) of the heating module (101). This causes a change in the angle α from the cold state α ₁ to the warm state α ₂ .

7 shows a simplified cross-section of the electronics housing (102), the heating module (101), and the conductor element (103) of an exemplary embodiment of the electric heater (100). The electronics housing (102), together with the electronics housing cover (115), forms an electronics interior (116). The heating module (101) protrudes through the opening (112) into the electronics housing (102) and the electronics interior (116), respectively, and a seal (111) seals the opening (112) in a fluid-tight manner. A cover element (118) is connected to the electronics housing (102) at a support surface (119) and is preferably mechanically connected thereto, for example, by a screw or clip connection. In the present exemplary embodiment, both the cover element (118) and the electronics housing (102) comprise an electrically conductive material, whereby the components are also electrically connected via the support surface (119). Also visible is a printed circuit board (117) which is placed on the cover element (118) via a support surface (120) and, in the case shown, is mechanically connected to it, for example by a Screw connection. The circuit board (117) is also in electrical contact via the connection lugs (114) of the heating module (101). This allows the contact electrodes (107) of the heating module (101) to be supplied with voltage, which in turn is used to supply and control the heating element (106). To enable contact, recesses in the cover element (118) can be seen in the area around the connection lugs (114). Apart from these recesses, the cover element (118) covers the heating module (101) towards the circuit board (117), preferably in a fluid-tight manner. Also visible is a conductor element (103), which is designed as a torsion spring with two legs and is rotatably connected to the cover element (118), whereby any relative movement between the cover element (118) and the conductor element (103) is prevented. One of the legs of the conductor element (103) is in electrical contact with the end face (104) of the heating module (101). This creates an electrical connection between the heating module (101) via the conductor element (103) and the cover element (118) and the electronics housing (102), which in turn is connected to the neutral conductor or ground connection of the vehicle.

List of reference symbols

100

Electric heater

101

Heating module

102

Electronics housing

103

Ladder element

104

front side

105

Main direction of thermal expansion

106

heating element

107

Contact electrode

108

insulation

109

Pipe

110

Heat transfer element

111

seal

112

Opening in the electronics housing

113

Bearing point of the conductor element

114

Connection lug of the heating module

115

Electronics housing cover

116

Electronics interior

117

circuit board

118

Cover element

119

Support surface for the cover element on the electronics housing

120

Support surface for the circuit board on the cover element

Claims (9)

An electric heater (100) for a vehicle, comprising - at least one heating module (101), wherein the 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 (102), wherein the heating module (101) projects through at least one opening (112) into the electronics housing (102), and wherein the opening (112) is sealed by at least one seal (111), and - at least one conductor element (103) arranged in the interior of the electronics housing (102) and electrically connecting the heating module (101) to the electronics housing (102), characterized in that the conductor element (103) connects the heating module (101) at one end face (104) electrically contacted. Stoker (100) to Claim 1 characterized in that the conductor element (103) is arranged completely above the heating module (101) when viewed in the longitudinal direction of the heating module (101). Heater (100) according to one of the preceding claims, characterized in that the conductor element (103) is designed in one piece with the electronics housing (102) or in one piece with the heating module (101). Heater (100) according to one of the preceding claims, characterized in that the at least one conductor element (103) electrically connects a heating module (101) adjacent to it to the electronics housing (102). Stoker (100) to Claim 1 characterized in that the conductor element (103) has at least one spring element which is tensioned in the installed state and ensures an electrical contact between the conductor element (103) and the adjacent component (101, 102) by the resulting spring force. Stoker (100) to Claim 5 characterized in that the conductor element (103) is designed such that the spring force vector of the tensioned spring element acts predominantly parallel to the direction of extension of the heating module (101). Heater (100) according to one of the preceding claims, comprising a cover element (118) which at least partially covers the heating module (101) projecting into the electronics housing (102) towards a printed circuit board (117). Stoker (100) to Claim 7 characterized in that at least one conductor element (103) is mechanically connected to the cover element (118), for example by a screw or clip connection. A method for producing an electric heater for a vehicle, comprising the following steps: - Providing at least one heating module (101) comprising at least one heating element (106) which is arranged between two contact electrodes (107) and is electrically insulated from a surrounding tube (109) by insulation (108), wherein heat-transferring elements (110) are arranged on the outside of the tube (109), - Aligning the heating module (101) with an electronics housing (102), wherein the heating module (101) protrudes at least partially through an opening (112) of the electronics housing (102), - Attaching at least one seal (111) in the opening (112) between the electronics housing (102) and the heating module (101), - Aligning and attaching a conductor element (103) such that the conductor element (103) connects the heating module (101) to the end face (104) of the Heating module (101) is electrically contacted and thus creates an electrical connection to the electronics housing (102).