DE102012212798A1 - Heating element and method for its production and use of the heating element - Google Patents

Abstract

The invention relates to a heating element (10) having at least one thermoelectric heating element (12), wherein the heating element (12) is at least partially formed with a conductive material and the heating element (12) via at least two conductor tracks (14, 16) with electrical energy is available. According to the invention, the conductor tracks (14, 16) are formed by means of a thermal spraying method, in particular by plasma spraying in accordance with DIN 657. As a result of the thermally sprayed conductor tracks (14, 16) results in a good electrical connection of the conductor tracks (14, 16) to the conductive particles within the matrix of the conductive material of the radiator (12). Furthermore, there is a mechanically strong connection of the conductor tracks (14, 16) to the radiator (12). The radiator (12) can be given a variety of three-dimensional shapes, so that for the heating element (10) results in a variety of applications. Thus, the radiator (12), for example, the shape of a tubular fluid line (50, 56, 70) have, so that the heating element (10) in addition to its actual heating function at the same time can fulfill other structurally predetermined tasks. On account of this functional integration or dual functionality, the use of the heating element (10) according to the invention results in significant constructive simplifications and optimization possibilities which entail a considerable cost-saving potential. In addition, the invention has a method, in particular for the production of the heating element (10), as well as uses of the heating element (10) to the object.

Description

State of the art

Many items contain one or more electric heating zones to transfer the heat energy to gases, liquids or solids. In the case of liquid media, such as Water, drinks, food, fuel, oils or chemicals should be heated, kept warm or kept from freezing. Solid bodies are often heated for comfort or to hold heat for another function.

In electrical heating elements Joule heat is generated when flowing through a conductor with electric current due to the electrical resistance. The heat output increases linearly with the electrical resistance of the conductor and squared with the current that has flowed through the conductor.

In today's motor vehicles, for example, to fit the comfort and environmental requirements, installed, for example, electric seat, window and exterior mirror heaters. The heating of the vehicle interior will become increasingly difficult with the electrification of the car, since no waste heat from the combustion process is more available. Therefore, for reasons of energy saving or comfort in the automobile, all contact surfaces and control elements should have integrated heating functions so that large-scale heating does not take place. Usually, the elements with which the user of an automobile has contact, indirectly heated by the heating air, which also takes a long time.

Due to the ever stricter exhaust emission limits, among other things, nitrogen oxides (NOX) in the exhaust gas flow of internal combustion engines, in particular diesel engines, must be reduced more and more. A common method used for this purpose is the catalytic reduction ("SCR process" = selective catalytic reduction) with the aid of a NO x reduction catalyst and a liquid reducing agent, such as a urea-water solution. In order to prevent the freezing of the reducing agent at low operating temperatures of the motor vehicle and to ensure reliable operation of the SCR system at temperatures of -12 ° C or below, usually all the essential components of an SCR system must be actively heated, resulting in a considerable technical effort results.

The curling and waxing of diesel fuel is today a growing problem in the use of diesel engines. The paraffin flocculates and sets the filter. Poor filters and base fuel of inferior quality cause the diesel fuel to flocculate even at higher temperatures. Diesel additives can be helpful in these cases, but they do not completely eliminate the problems and are also expensive. Heating the filter is often necessary.

Filter housings esp. For fuels are already heated today. However, this requires the installation of a separate heating element. The present invention, however, provides a heater integrated in the filter housing.

Batteries should not be operated at low temperatures as this will seriously affect the service life. In particular car batteries are exposed to environmental influences and endangered during a cold start. A heat flow from the outside takes a long time to heat larger battery blocks.

The freezing of adapters, fittings, nozzles, pipes, hoses, valves, or manifolds that are to be traversed by liquids or gases will cause system failure. The defrosting or continuous heating must be done externally with high energy losses or complex recessed heaters usually on PTC basis and insulation.

From the DE 10 2006 032 678 A1 For example, an electric heater for a mirror glass, for example an automotive exterior mirror, is known. The heating element used comprises a nonwoven material, in particular a glass fiber fleece, which is back-injected with a thermoplastic plastic material to create a carrier plate. There is a material connection between the back of the nonwoven material and the thermoplastic material. On a front side of the nonwoven material are meander-shaped conductor tracks made of a resistance material by a thermal spraying method according to DIN 657 applied, wherein preferably the so-called arc spraying method is used. The connection between the end sections of the conductor track and the electrical contacts for connecting a supply voltage for the heating device is preferably carried out by a soldering method before inserting the intermediate layer in the injection mold. By applying the conductor track with a sufficiently strong electric current heat is released, which allows a de-icing of the exterior mirror and prevents the re-travel while driving.

Furthermore, it is known to apply printed conductors by screen printing on a plastic substrate. Alternatively, films with printed conductors, electrically conductive adhesive tapes or conductive paints can be applied to a plastic component. The heat generation is based in these Cases on the ohmic loss line of the current-carrying conductor tracks. The disadvantage here is that in the case of a break only one trace can at least come to a partial failure of the electrical resistance heating. In addition, the heat generated superficially in the current-carrying conductor tracks and is due to the typically low thermal conductivity for plastics passed on from the conductor track side of the substrate on the side facing away from this only slowly. This results in a sluggish response of the heating element.

Furthermore, from the DE 44 29 028 A1 electrically conductive thermoplastic composites and a process for their preparation known.

In a pure state electrically insulating plastic matrix electrically conductive fillers are mixed for the production of a Leitkunststoffes. For this purpose, e.g. Metal powders, carbon black, carbon fibers, metal fibers, brazing alloys, "CNT" (see Carbon Nano Tubes) or other nanoparticles into consideration. The degree of filling must exceed a certain minimum in order to form a sufficient number of electrically conductive paths within the composite material. From this Perkulationsgrenze the electrical resistance is no longer infinite and the electrical conductivity increases. Such composites achieve specific electrical volume resistivities of less than 5 Ω · cm and contain up to 70.0% by volume of electrically conductive fillers.

A characteristic that is particularly desirable for safety reasons is in many cases the self-regulation of the conductive plastic in a specific temperature range. The thermal self-regulation range can be set within wide limits, for example, by the constituents of the mixture, their thermal expansion coefficients, the proportion of filler, the matrix material and / or the mixing ratios. In such Leitkunststoffen with a positive temperature coefficient (PTC characteristic) of the electrical resistance increases with increasing temperatures automatically, at the same voltage flows less current, so that there is no overheating of the heating element and a resulting fire risk can be almost eliminated. A heating element, which is formed with a conductive plastic, has, among other things, the advantage that the heat over the entire volume of the plastic component uniformly arises and is released in relation to a heating element which operates with a conductor track as a resistance heating element.

From the DE 297 22 304 U1 Furthermore, an electrically heatable mirror assembly is known. The heating of a mirror by means of a carrier plate made of a conductive plastic, on which the mirror is mounted. The electrical connection is realized with metallic connection contacts, which are inserted into the mold, for example, before or during the injection molding process of the carrier plate. Alternatively, the terminal contacts can also be subsequently glued or welded, for example by means of ultrasound to the support plate. The heating elements can be integral components of the carrier plate, by forming these or parts thereof of the conductive plastic, for example in the multi-component injection molding process and provided with the corresponding terminal contacts. Disadvantages of this electrical contacting are inter alia in the low mechanical adhesion to the surface of the support plate and their thermal load and in the unfavorable, that is in particular the very high-impedance and less contact-safe and sensitive to vibration, electrical coupling to the conductive fillers within the matrix of Conductive plastic of the backing plate.

The DE 20 2010 009 208 U1 has a flexible, areal thermoelectric heating element to the object. The heating means is formed with an electrically conductive plastic. The supply of the heating medium with electricity in heating operation via conductor track-shaped contact means. The contact means are attached to the heating means, for example by means of electrically conductive adhesives. Alternatively, the contact means may also be incorporated in or incorporated in the heating means. Furthermore, it is possible to print or evaporate the contact means on a layer formed by the heating means. The contact means consist of an electrically conductive material, such as a metal such as copper, a silver conductive paint or a gold conductive paint. Alternatively, carbonaceous materials, such as carbon fibers come into consideration. The formation of the contact means designed in this heating element, especially in a complex contact means, procedurally quite complex, difficult to reproduce and therefore only a little process reliability.

The DE 36 14141 D2 shows that in addition to electrically conductive plastics and based on ceramic materials, a heating element can be constructed. A ceramic mixture of silicon nitride and titanium nitride is used.

Disclosure of the invention

It is disclosed a heating element with at least one thermoelectric heater, wherein the radiator is at least partially formed with a conductive material and the radiator is supplied via at least two conductor tracks with electrical energy. According to the invention, the conductor tracks by means of a thermal spraying method, in particular by plasma spraying according to DIN 657 , educated.

As a result, a very good mechanical adhesion of the conductor tracks on the radiator and an optimal electrical contact with the fillers in the matrix of the conductive material is achieved, so that the radiator can be supplied very reliably with power. In addition, the thermally sprayed tracks have a high abrasion resistance and a homogeneous microstructure, resulting in a low electrical resistance and low line losses. The conductor tracks reach a material thickness of up to 1 mm. In addition, the thermal spraying process ensures a high degree of repeat accuracy or process reliability and a large freedom of design with regard to a three-dimensional structuring of the conductor tracks.

The resistance heater formed with the conductive material can be injection molded, extruded or pressed, for example. In order to form electrically insulating regions, multicomponent injection molding processes, painting processes and / or welding processes are suitable. As a result, it is possible to produce fluid-tight and pressure-tight multicomponent heaters which, in addition to the conductive material, can also contain insulating materials (insulators) and materials or assemblies. As fluids are gaseous and / or liquid media or chemicals of all kinds, such as water, urea-water solutions (sg "AdBlue ^® "), fuels, refrigerants, oils, food, water vapor, nitrogen, oxygen, hydrogen, methane, propane , Butane, acetylene etc. understood.

Due to the radiator formed at least partially with the conductive material is a uniform heat dissipation and at the same time - in comparison to conventional electrical resistance heaters - very energy efficient heat generation possible. In addition, the injection molding process allows a variety of design options in terms of the spatial geometry of the radiator. The conductive material may be formed with thermoplastics, with thermosets and / or with elastomers which, in addition to other physical properties such as strength, water absorption and weight, in particular must have sufficient temperature resistance for the target application. To further optimize its mechanical properties, the conductive material - in addition to the electrically conductive particles - be provided with a fiber reinforcement. Optionally, the Faserarmierung, for example in the case of carbon fibers, take over the function of the conductive particles with. Preferably, the matrix of Leitkunststoffes is formed with a temperature-resistant high-performance thermoplastic.

As an alternative to the plastic and electrically conductive ceramics can be provided with traces. This may be, for example, an aluminum oxide titanium nitride ceramic. The shape of the main body can e.g. via pressing or powder injection molding. It can be compared to the plastic set much higher temperatures. The self-regulating properties are also based on the ceramics.

The spray method for applying the printed circuit traces ensures a low thermal load on the heater during the track application and has a surface cleaning effect. The printed conductors can be produced, for example, with metallic materials, such as, for example, copper, tin or aluminum. In this case, it is possible to apply conductor tracks whose layer thickness and spatial shape can be influenced in a wide range, in particular by the travel speed of the spray burner, the temperature of the spray jet, the flow velocity of the metal powder in the spray jet or by multiple passes with the spray burner. In addition, the conductor track on the radiator can be made almost arbitrarily complex by appropriate method of the spray burner on preprogrammed trajectories. Furthermore, a good electrical contacting of the sprayed-on conductor tracks to metallic connection points (interface points, contact pins) is given, which makes additional soldering or welding generally superfluous. The heating element may e.g. be used for heated contact surfaces, as a DNOX heating element or as a universal media or fluid heating element.

An advantageous development of the heating element provides that the conductive material is thermally self-regulating. As a result, overheating and the associated risk of fire are almost impossible. The self-regulation is based on a temperature-induced expansion of the matrix of the conductive material, which leads to greater distances between the conductive particles in the conductive material. As a result, the ohmic resistances of the electrical conductive paths within the conductive material increase with increasing temperature, whereby the current intensity and the heat development decrease.

In accordance with a further embodiment, the interconnects are in each case electrically conductively connected to at least one electrical connection point, in particular to at least one contact pin.

Through the electrical connection points or interfaces, a preferably pluggable electrical connection of the conductor tracks to an external power supply, such as an electrical direct voltage network of a power, water or aircraft, possible. The electrical connection points may be metallic contact pins (sg contact pins), contact tracks, contact springs, contact sockets, contact lugs, contact sleeves, Lötfahnen, pads, tabs, round plug, blade receptacles, circular sockets, sockets, wires, strands, stamped grid or the like. The connection points are preferably mechanically fixedly connected to the radiator, that is integrated in this and / or arranged on this. For this purpose, the metallic connection points with the conductive material and / or the insulating material may be at least partially encapsulated or introduced after the injection molding of the heater in this and / or applied thereto. Alternatively, the connection points can also be screwed into the radiator, riveted with this or glued on this with a conductive or non-conductive adhesive. The pressing in or knocking in connection points is also possible. An integral design of a plug box made of an insulating material for receiving a plurality of preferably positioned in a grid connection points is conceivable. Alternatively, the connection points can also be formed with a conductive material. Furthermore, it is possible to connect the connection points by passing over with the spray burner in the course of the thermal spraying process, in particular the plasma spraying process, to the conductor tracks. Also, the connection points can be electrically connected by conductive adhesive strips or by the application of conductive ink.

In accordance with a further embodiment of the heating element, the heating element has a substantially plate-shaped, cylindrical, hollow-cylindrical or pot-shaped shape. In order to adapt the conductor track structure to the available surface of the heating element and optimally design it, the printed conductor structure can be branched, fanned or offset. One possible embodiment is the execution as mutually entangled comb structures. A design with constant electrical resistance between two points on oppositely polarized tracks is optimal to achieve uniform heating in the area. The self-regulating properties and the high thermal conductivity coefficient of a thermally regulating and electrically conductive thermoplastic ensure a good balance of local temperature differences.

This makes it possible to integrate the radiator in a variety of different applications. In a particularly advantageous manner, the radiator is given a spatial form which images at least a portion of an application to be equipped with the heating element. This means that the heating element in addition to its actual heating or heating function at the same time assumes at least one task of a component of the application to be equipped herewith. Since the radiator is preferably made of single-component or multi-component injection molding of the conductive material and optionally other materials, the radiator can be given almost any three-dimensional shape. For example, in addition to its actual heating function, a hollow-cylindrical or tubular heating element at the same time assumes the forwarding function of a fluid, in particular a liquid or a gas. In addition, the heating element, for example, the complex spatial shape of a valve housing or a ball valve can be given, so that the heating element on the one hand prevents the freezing of the valve and at the same time also converts the control function of the valve. A separate valve heater is eliminated without replacement. This functional integration results in considerable structural simplifications, which entail a considerable potential for rationalization and cost savings in the manufacture of technical devices of all kinds.

A further advantageous embodiment of the heating element provides that the radiator is at least partially formed with an assembled bulk material, in particular with sintered balls and / or with sintered granules, from the conductive material. This results, inter alia, an increase in the effective heat transfer surface of the radiator. Alternatively, the radiator may be formed, for example, as a hollow profile, wherein inside parallel to the longitudinal axis extending webs are formed to increase the surface area. Here, hollow cylindrical or tubular profiles, rectangular hollow sections or square hollow sections can be used. In the case of hollow cylindrical profiles, for example, the webs may be formed radially outward or star-shaped starting from a longitudinal axis of the hollow profile.

In accordance with an advantageous further development, at least one further electrical conductor, in particular at least one conductor track, is fastened to and / or in the radiator, in particular adhesively bonded, welded, soldered or pressed onto it and / or injected into it.

As a result, if necessary, further, additional printed conductors can be formed and / or fixed on and / or in the heating element with a technology deviating from thermal spraying technology.

In the case of a favorable development, the radiator has at least one electrical insulating region and / or at least one further component, wherein the insulating region is formed with an electrical insulator, in particular with an insulating plastic. As a result, for example, different Leitmaterialzonen within the Radiator be created by the formation of electrical isolation areas or isolation zones. Further, if necessary, another structural component or assembly may be integrally molded onto the heater body or integrated therein by other process technologies. This may be necessary, for example, to increase the corrosion resistance to chemically aggressive media and / or to ensure the safety of food. For example, a tubular heating element may be provided with an inner lining of PTFE. For this purpose, preferably multi-component injection molding or thermoplastic welding, such as ultrasonic welding, are used. Furthermore, any metallic or non-metallic components or components or assemblies can be integrated into the radiator. In principle, the radiator can be manufactured with any desired metallic and / or non-metallic combination of materials suitable for the respective target application of the heating element.

Variations in the wall thicknesses of the conductive material can be used selectively to locally produce different heating on the component surface.

In addition, the formation of the electrical conductivity can be influenced during the shaping of the heater from conductive material on the Abformgeschwindigkeit. In injection molding, moreover, the definition of the injection points is decisive for the subsequent electrical conductivity of the heating element.

Tempering processes interposed between the production process can cause a change in the electrical conductivity of the conductive material.

In addition, a method for producing a heating element, in particular a heating element according to one of claims 1 to 7, disclosed with at least one thermoelectric heater, wherein the radiator is at least partially formed with a conductive material and the radiator is supplied via at least two conductor tracks with electrical energy ,

• a) Herstellen eines thermoelektrischen Heizkörpers mit einem Leitmaterial,
• b) Aufbringen der Leiterbahnen auf den Heizkörper mittels eines thermischen
• Spritzverfahrens, insbesondere durch Plasmaspritzen gemäß DIN 657 , und
• c) Herstellen von mindestens zwei elektrischen Anschlussstellen zur elektrischen
• Kontaktierung der Leiterbahnen.

According to the invention, the method is characterized by the following steps:

• a) producing a thermoelectric heater with a conductive material,
• b) applying the conductor tracks on the radiator by means of a thermal
• Injection method, in particular by plasma spraying according to DIN 657 , and
• c) making at least two electrical connection points for electrical
• Contacting the conductor tracks.

The production of the thermoelectric heating element in method step a) is preferably carried out by injection molding, which allows a high freedom of design with respect to the three-dimensional shaping of the radiator. The application of the strip conductors by means of a thermal spraying method in the course of method step b) makes it possible to electrically connect the metallic strip conductors to the heating element, which is formed at least in regions with a conductive material. The thermal spray process also ensures a largely free design of the conductor track course. In addition, the thermal spraying method enables a mechanically and electrically very reliable connection of the conductor tracks to the radiator. In the concluding process step c), at least two electrically conductive, preferably metallic connection points for the electrical connection of the conductor tracks and thus of the heating element to an external power supply are formed. The electrical connection points can in this case, for example, by welding, melting, hitting or pressing metallic contact pins (sg contact pins), contact tracks, contact springs, contact sockets, contact lugs, contact sleeves, Lötfahnen, Lötaugen, flat connectors, circular connectors, tabs, circular sockets, sockets, wires, strands Punching or the like are made on or within the radiator. In this case, a conductive connection between the conductor tracks and the connection points is usually created at the same time due to the resulting mechanical contact. In addition, between the connection points and the conductor tracks soldering and / or welded joints may be provided to further increase the electrical conductivity. Any welds are preferably made by laser welding.

Alternatively, the sequence of process steps b) and c) can be interchanged, or process steps b) and c) can also be carried out simultaneously. This results in the advantage that an intimate electrical contact and a solid mechanical connection between the conductor tracks and the connection points are already formed in the course of the thermal spraying process. For in the thermal spraying of the tracks metallic material is at least partially sprayed with on the connection points and goes with these an intensive electrical and mechanical connection. In a development of the method, it is provided that the at least two electrical connection points are formed in method step a). This eliminates the separate creation of the electrical connection points after completion of the injection molding process. So the connection points before the Injection molding process are inserted in the mold used for the injection molding process.

In addition, a use of at least one heating element according to the invention as a fluid line is disclosed.

As a result, for example, the freezing of a fluid to be passed, for example in the form of a urea-water solution within an SCR system, can be prevented. The heating element allows a functional integration in such a way that the fluid line with the integrated heating element or designed as a fluid line heating element on the one hand holds the actual line function and on the other hand assumes the task of a separate thermoelectric resistance heating. The fluid line may be rigid and / or at least partially flexible and have any cross-sectional geometry. Furthermore, a use of at least one heating element in a fluid functional unit, in particular in a fluid heater, in an adapter, in a nozzle, in a throttle, in a valve, in a distributor or in a filter housing of a filter is disclosed.

This results in a function bundling due to the heating element inherent double function in the form of a thermoelectric resistance heating and as a fluid functional unit, which among other things leads to a cost reduction in the manufacturing process and opens up new application fields. In addition, a use of at least one heating element in a commodity, in particular in a food warmer, in a Aquarienheizstab, in a heated handle, in a steering wheel, in a mirror, in a seat heater, especially for hard shell seats, for example, for football stadiums, in an iron, in particular as soleplate, in an accumulator, in heaters in door locks, in roof drains or gutters, in heated paper rolls in copiers, in particular in a housing of a lead-acid battery or within a contact surface of electrical equipment (eg fittings of cars, computer mouse, mobile phone with pocket warmer function) , disclosed.

The use of the heating element as a food warmer allows, inter alia, a manufacturing technology simple production. In addition, the food warmer has a low weight, can be easily manufactured in one piece manufacturing technology, for example in the multi-component injection molding and / or thermoplastic welding and generates even at low currents for uniform heating or keeping warm enough heat. As a result, the food warmer is predestined for mobile use in land, water and air vehicles. Examples of a food warmer are: coffee mugs, baby food warmers or camping stoves. With a food warmer according to the invention extended by a connecting line, the realization of heated wells or animal feeders is given.

The use of the heating element to create a soleplate for an iron, especially for a travel iron, on the one hand leads to a low total weight of the iron. In addition, the manufacturing process of the soleplate is simplified because, for example, holes and recesses are easier to produce by injection molding and also eliminates the application of a lubricious coating on the soleplate. A lead-acid battery equipped with the heating element according to the invention can be heated, so that the usual electrical power loss at low temperatures, which often leads to cold start difficulties in motor vehicles in winter operation, no longer occurs. The heating element can be positioned for example between at least two lead plates within the housing of the lead-acid battery. Alternatively, it is possible to form the housing of the lead-acid battery itself at least in regions as a heating element.

Brief description of the drawings

With reference to the drawing, the invention will be described below in more detail.

It shows:

1 a basic variant of a heating element according to the invention with a plate-shaped radiator,

2 a substantially tubular fluid heater with integrated heating element,

3 a sectional view of a lead-acid battery with built-in heating element,

4 a first embodiment of a heating element designed as a fluid line,

5 a second embodiment of a heating element designed as a fluid line,

6 a third embodiment of a heating element designed as a fluid line,

7 a cross-sectional view of a food warmer with a heating element,

8th a longitudinal section through an adapter with a heating element,

9 a cross-sectional view along the section line IX-IX in 8th .

10 a side view of the adapter according to 8th .

11 a trained as a sole plate for an iron heating element in a plan view,

12 a variant of a heating element for a soleplate of an iron,

13 a cross section of a sole plate with a wedge-shaped height profile for a uniform heating power, and

14 a cross-sectional view through a filter with a filter housing, in which a heating element is integrated,

15 . 16 . 17 . 18 a basic variant of the heating element proposed according to the invention for use as a heating cartridge,

19 . 20 a representation of a heated with the heating element according to the invention steering wheel,

21 . 22 a design variant of the inventively proposed heating element as handle heating and

23 . 24 and 25 an embodiment of the present invention proposed heating element as contact surface heating and

26 an embodiment of the present invention proposed heating element as a development of a cylindrical surface.

embodiments

The 1 shows a schematic representation of a basic variant of a plate-shaped heating element.

The heating element 10 includes, inter alia, a cuboid radiator 12 which is made with a conductive material. On an unspecified top of the radiator 12 run two electrical conductors 14 . 16 spaced parallel to each other. Between the tracks 14 . 16 exists due to the conductive material an ohmic (volume) resistance R. Within the ohmic resistance R of the radiator 12 carries a current I at one between the two tracks 14 . 16 applied voltage U to a thermal power loss P according to the relationships and, which is emitted as heat or as here desired heating heat. The current I runs essentially in a transverse direction between the conductor tracks 14 . 16 or perpendicular to these through the radiator 12 , Notwithstanding the shown, spaced parallel arrangement of the two interconnects 14 . 16 , these can be optionally on the top and / or bottom of the radiator 12 be provided in any number. Furthermore, the tracks can one of the 1 have a different course and be designed, for example meandering or curved. Alternatively, the tracks can also on non-designated end faces of the radiator 12 be upset.

The tracks 14 . 16 be according to the invention by means of a thermal spraying method according to DIN EN 657 , in particular by means of a plasma spraying method, on the radiator 12 applied and may be formed, for example, with copper, tin or aluminum. The thermal spraying process ensures an electrically effective connection between the conductor tracks 14 . 16 and the conductive particles within the conductive material of the radiator 12 , In addition, the thermal spraying allows a mechanically highly resilient connection of the conductor tracks 14 . 16 to the radiator 12 or its top, bottom and / or front sides. Inside the radiator 12 The heat is released evenly, resulting in a very homogeneous heat distribution. Due to the preferred self-regulating characteristics of the conductive material used is an overheating of the radiator 12 almost impossible. Another advantage of the conductive material is that even at low operating voltages or currents quite high temperatures can be reached, whereby the heating element 10 especially for energy-efficient use in mobile applications, such as in motor vehicles, is predestined. The electrical (volume) resistance R between the tracks 14 . 16 of the heating element 10 is for example 60 Ω. By applying a DC voltage of, for example, 12 volts results then due to the self-regulating conductive material, a maximum current I of 0.2 A, the heating of the heating element 10 to a temperature of 50 ° C at a power of 2, 4 W causes. The conductive plastic also allows media-tight extrusion coating with a proven compressive strength of at least 1 bar.

For further electrical contacting of the conductor tracks 14 . 16 , for example, the on-board power supply of a car, serve two electrical connection points 18 . 20 of which the junction 18 exemplary with a negative pole and the connection point 20 is connected to a positive pole of the DC power supply, not shown. Alternatively, a supply of the heating element 10 take place by means of alternating current. The plate-shaped or cuboid radiator 12 represents the simplest geometric design option of a radiator 12 , Basically, the radiator 12 Any spatial geometry can be awarded, which can take over their actual heating task addition, further constructive functions within a device with. In the further progress of the description are all heating elements 10 - including the associated tracks 14 . 16 as well as the electrical connection points 18 . 20 without prejudice to the geometric shape of the radiator 12 and / or its intended use - always with the reference numbers 10 to 20 Mistake.

In the illustrated embodiment of the 1 are the connection points 18 . 20 as metallic contact pins or contact lugs 22 . 24 (Flat plug contacts) formed on the example corresponding tabs or sockets are attachable. The connection points 18 . 20 may be formed, for example, with copper, tin or aluminum. Alternatively, wires, strands or ribbon cables can be used to create the connection points 18 . 20 also directly to the pins 22 . 24 soldered or welded for example by laser beam welding. The contact pins 22 . 24 even in the radiator 12 melted, pressed or otherwise mechanically anchored in it. Alternatively, the contact pins 22 . 24 for example, during injection molding of the radiator 12 be inserted into the mold and are then encircled by the conductive material. To make an electrical connection between the contact pins 22 . 24 and the tracks 14 . 16 to create the tracks 14 . 16 in an advantageous way to exposed sockets 26 . 28 the contact pins 22 . 24 sprayed. To ensure proper electrical contact, close the sockets 26 . 28 preferably flush with the top of the radiator 12 from. Alternatively, other electrical contacting options can be used. For example, the contact pins 22 . 24 also directly on the tracks 14 . 16 be soldered. In addition, it is possible to use the contact pins 22 . 24 from the conductive material of the radiator 12 or for the contact pins 22 . 24 to use another Leitkunststoff or a Leitkeramik. In principle, all thermoplastics, thermosetting plastics, elastomers and ceramics with and without fiber reinforcement can serve as matrix material for the conductive material and moreover as insulating material. It is particularly advantageous if a fiber reinforcement in the matrix of the conductive material at the same time takes over the electrical line function in addition to its mechanical reinforcement task.

The 2 illustrates in a schematic perspective view a fluid heater, with a heating element according to the invention 10 equipped.

The fluid warmer 30 includes, inter alia, the here hollow cylindrical or tubular heating element 10 with the two tracks 14 . 16 that with the connection points 18 . 20 are electrically connected. At both ends of the heating element 10 is in each case an end piece 32 . 34 formed or integrally formed. Every tail 32 . 34 has a tubular neck 36 . 38 , where the tail 32 additionally with a plug box 40 for receiving the connection points 18 . 20 and a connector, not shown, is equipped. The heating element 10 thus extends only in a portion of the fluid heater 30 , About the connection points 18 . 20 the electrical connection of the tracks takes place 14 . 16 with an electrical power supply, not shown. The tails 32 . 34 are for example formed with an electrically insulating plastic, which is preferred during injection molding of the radiator 12 with at this, for example by way of a multi-component injection molding, injection molded. The fluid warmer 30 can be used, for example, in SCR systems for NOX reduction in the exhaust gas flow of diesel engines. In these systems, the fluid warmer 30 advantageously be looped for example in lines for the reducing agent to prevent their freezing at temperatures of -12 ° C or below. The supply and the removal of the reducing agent takes place via the nozzle 36 . 38 ,

The 3 shows a schematic cross-sectional view through a lead-acid battery, with the heating element according to the invention 10 Is provided.

The lead-acid battery 42 includes a housing 44 with two lead plates recorded in an unspecified electrolyte 46 , Between the lead plates 46 is this plate-shaped heating element 10 with both sides on the radiator 12 applied conductor tracks 14 . 16 arranged. Between the heating element 10 and the lead plates 46 each there is a small, not designated gap. The heating element 10 If necessary, especially at low ambient temperatures, for heat generation via the connection points 18 . 20 energized and allows the warming up of the lead-acid battery 42 or of the electrolyte. Due to the preferred large radiator 12 is a rapid heating of the electrolyte possible. As a result, the cold start capability of a motor vehicle can always be ensured even under adverse environmental conditions. The for heating the heating element 10 necessary power is preferably taken from an external source, such as the public power grid, a solar panel, a primary element or the like. In the illustrated embodiment, however, the power is at least partially from the lead-acid battery 42 taken by himself, causing this at low Temperatures initially further discharged. However, this effect is due to the rapidly increasing as a result of the heat release electrical performance of the lead-acid battery 42 - Compared with a positive feedback - Compensated for the most part. For this purpose, the positive pole and the negative pole ("+" and "-" sign with circle) of the accumulator 42 with the connection points 18 . 20 electrically connected. For electrically insulating implementation of the connection point 20 has the track 14 over a small recess 48 , Instead of the lead-acid battery 42 For example, other secondary elements based on alternative chemical systems may also have at least one heating element 10 be equipped.

The 4 shows a first embodiment of the heating element 10 , which is designed as a fluid conduit for a gaseous or liquid medium. In the simplest case of a heatable fluid line are the heating element 10 or the radiator 12 as a rigid or flexible hollow cylindrical member or as a pipe or a flexible hose. The heating element 10 may extend over a portion of the fluid conduit or over its entire length.

In a fluid line 50 according to 4 is the heating element 10 designed as a hollow profile with an approximately square outer and inner geometry. To increase the effective heat transfer surface are in an unnamed interior of the fluid line 50 two bridges 52 . 54 provided in the region of a likewise not provided with a reference numeral longitudinal axis of the fluid line 50 penetrate at right angles. The radiator 12 and the two bridges 52 . 54 are preferably in one piece, for example, extruded from the conductive plastic and provide the fluid line 50 This takes over the heating element 10 In addition to its actual heating function additionally the task of a pipe or a hose line, which reduces the number of necessary components and results in a considerable potential savings. A the fluid line 50 flowing medium can in an energy efficient manner by means of the heating element 10 warmed up and led at the same time. The power is supplied by the connection points not shown here and the printed conductors 14 . 16 , The tracks 14 . 16 are in turn preferably formed by means of a thermal spraying process, in particular by means of plasma spraying. In addition, further strip conductors can be formed by gluing, welding, pressing or injection-molding during the injection molding process. The unspecified connection points are corresponding to the statements in the explanation of the 1 produced. To increase the corrosion resistance and to ensure food safety, the fluid line 50 be lined inside at least partially with a so-called lining, wherein the lining or the inner lining is formed with a different plastic than the Leitkunststoff. An inner lining may also be necessary for electrical insulation in the case of conductive fluids. The lining can be made, for example, by multi-component extrusion with polytetrafluoroethylene (PTFE). In a particularly advantageous manner, the fluid line 50 be used in a SCR system of a motor vehicle as a reducing agent line.

The 6 shows a second embodiment of a fluid line.

Unlike the first embodiment according to 4 also points as a fluid line 56 trained radiators 12 an approximately annular or tubular cross-sectional geometry. To increase the effective heat transfer surface are in a non-designated interior three webs 58 . 60 . 62 provided in the region of a not provided with a reference numeral longitudinal axis of the fluid line 56 penetrate and form six unsigned sectors each about 60 °. Through the free cross-sectional areas of these sectors flows by means of the fluid line 56 to be conducted and heated gaseous or liquid medium. In the area of an outer wall 64 are also two isolation areas 66 provided, which are formed with an electrically insulating plastic (insulating plastic). Through the isolation areas 66 Among other things it is ensured that the electricity is also through the bars 58 to 62 and not exclusively by the outer wall 64 flows. The bridges 58 to 62 and the heating element 10 with the radiator 12 as well as the two isolation areas 66 For example, by means of the multicomponent extrusion process preferably made in one piece from the conductive plastic and the insulating plastic. The production of the conductor tracks 14 . 16 as well as the connection points, not shown 18 . 20 takes place analogously to that in the context of 1 explained procedure. Both the isolation areas 66 as well as the outer wall 64 the fluid line 56 are preferably formed with the insulating plastic. Notwithstanding the illustrated three webs 58 to 62 can only have one, two or even more than three bars 58 to 62 be provided. As the heating element 10 at the same time the fluid line 56 is, can the fluid line 56 flowing fluid - compared to a pipeline with external resistance heating - heated or tempered very energy efficient.

The 6 illustrates a cross-sectional view through a third embodiment of a fluid conduit.

The structural design of the fluid line 70 with the heating element 10 , the radiator 12 , the tracks 14 . 16 and the isolation areas 66 in the outer shell 64 corresponds essentially to the structure of the fluid line 56 in 5 , In contrast to the fluid line 56 with the three webs of undeclared interior is here completely with a bulk material 72 filled to further increase the heat transfer surface. The bulk material 72 is preferably formed with balls and / or granules of the conductive material, which are firmly together, for example by sintering, assembled into a compact unit and at the same time with an unnamed inner wall of the fluid line 70 are firmly connected. The bulk material 72 For example, in an additional manufacturing step using pressure and temperature in the fluid line 70 be sintered. However, this unit or ball packing still has enough cavities to allow a largely unhindered passage of a fluid. The bulk material 72 is here as a complex shaped part of the heating element 10 or the radiator 12 specific. The bulk material 72 with its extremely large surface area results in a very large heat transfer surface, so that a fluid can be heated to high temperatures in a short time. This leads to an optimal temporal response of the heating element 10 ,

The 7 shows a cross-sectional view of a food warmer with integrated inventive heating element.

The food warmer 80 includes, among other things, a double-walled housing 82 , in which in this constellation cup-shaped radiator 12 as a heating element 10 is included. The double-walled housing 82 preferably consists of a food-compatible and sufficiently temperature-resistant insulating plastic and forms an interior 84 for holding the food or other substances to be heated. To increase the mechanical strength of the insulating plastic may have a reinforcement with electrically non-conductive reinforcing fibers. In the embodiment of 7 is the interior 84 as an example partially filled with a liquid, for example water. With the help of the food warmer 80 All kinds of food can be brought to serving temperature as well as kept only on this. The impingement of the radiator 12 with electrical energy via the two tracks 14 . 16 as well as the hereby electrically connected connection points 18 . 20 , The tracks 14 . 16 are here corresponding to the radiator 12 as well as the double-walled housing 82 likewise pot-shaped, planar (surface electrodes) designed. For electrically insulating implementation of the connection point 20 is in the track 16 as well as the housing 82 a small bottom recess 86 admitted. To reduce the energy losses when heating, the food warmer can 80 be provided with a lid, not shown. The radiator 12 with the here approximately U-shaped cross-sectional geometry ensures a uniform and rapid heating of the food, which already with DC voltage in a range of up to 48 volts sufficiently high temperatures in the interior 84 are reachable. The high heat generation of the heating element even at low DC voltages 10 predestines the food warmer 80 especially for energy-efficient use in mobile applications, such as power, water and air vehicles. In principle it is possible, at least the housing 82 and the heating element 10 including the radiator 12 cost-effective and mass-produced in one piece to produce in multi-component injection molding. The tracks 14 . 16 are preferably applied in an intermediate step by means of a suitable thermal spraying process and to the connection points 18 . 20 electrically connected. Deviating from this, the conductor tracks 14 . 16 as well as the connection points 18 . 20 be electrically connected to each other in an upstream of the injection molding process, for example by soldering or laser beam welding and then inserted into a mold used for the final injection molding process. The connection points 18 . 20 can be made, for example, by overmolding punched gratings with an insulating plastic or over-molded with insulating plastic contact pins - which then with a spray torch in the course of the plasma spraying, with the metallic interconnects 14 . 16 be applied at least once to create a conductive connection.

A via between two components, such as between the food warmer 80 and a connecting element, such as a sleeve with hose, can be realized by provided, matched electrical contacts that forward the electrical current in the mounted state. For the production of the housing 82 Multi-component injection molding processes can be used to connect media-thermally and thermally insulating housing elements to pressures of more than 1 bar in a media-tight manner. Welding processes can also be used. By painting or foil injection molding process, the interior 84 be provided at least partially with protective layers.

Extensive series of experiments with the food warmer 80 have shown, for example, that water can easily be heated up to 50 ° C. Closer distances between the tracks 14 . 16 are also higher temperatures reachable. In air heating curves were determined up to 98 ° C in about 3 to 4 minutes. The low supply voltage of the radiator 12 of, for example, 12 volt, 24 volt or 48 volt dc predestines the food warmer 80 doing so for energy-efficient mobile applications, especially in motor vehicles. The food warmer 80 with integrated heating element 10 can also be designed as baby food warmer, mug, cup, pot, pot, thermo container, camping stove, coffee maker, animal cabinets or the like.

The 8th to 10 , to which reference is also made in the further course of the description, show a constructed with the heating element according to the invention (fluid) adapter as a further example of application.

A substantially hollow cylindrical adapter 90 has inter alia a stepped inner lining 92 concentric with the here hollow cylindrical radiator 12 of the heating element 10 is wrapped. The inner lining 92 is formed with a material other than the conductive material with which the radiator 12 of the heating element 10 is constructed. Preferably, the inner lining 92 formed with an insulating material which is highly resistant to chemically aggressive media, high mechanical strength, good pressure resistance, high temperature resistance and / or for food applications. The two-component structure allows the adapter 90 easily adapt to different requirements of target applications. At least the inner lining 92 and the radiator 12 can be made by the two-component extrusion process and / or the two-component injection molding process.

The electrical connection of the radiator 12 takes place again by means of the conductor tracks 14 . 16 as well as the two connection points 18 . 20 analogous to the statements already made. The inner lining 92 has two holes 94 . 96 on, by a circulating Rezess 98 or a small paragraph are separated from each other. An inner diameter 100 the first hole 94 is smaller than an inner diameter 102 the second hole 96 , Thus, the adapter 90 For example, serve as an electrically heatable transition piece between two pipes with different diameters or as a heatable connection piece.

In an unnamed entrance area of the first hole 94 may be provided a mechanical lock, not shown, by means of which, if necessary, a detachable connection of the adapter 90 to a component, not shown, or a functional unit is possible. Accordingly, the adapter has 90 in the region of the outlet via preferably two integral to the radiator 12 of the heating element 10 executed snap hooks 104 . 106 , which are formed with an insulating plastic and not from the conductive plastic. Alternatively, the snap hooks 104 . 106 also be formed with a metallic material. Next to the snap hooks 104 . 106 can be sprayed with other, possibly movable components. The diametrically arranged on the adapter 90 snap hooks 104 . 106 are used preferably for latchable and, if necessary detachable connection of the adapter 90 to another, not shown, component or functional unit. The snap hooks 104 . 106 can also be used when mounting the adapter 90 be injected with these.

The cross-sectional view in 9 shows a cross section through the adapter 90 along the section line IX-IX from the 8th ,

The adapter 90 includes the inner lining 92 with the first hole 94 , coaxial with the radiator 12 is enclosed. On the radiator 12 are the tracks 14 . 16 with the connection points 18 . 20 , In addition, the rear snap hooks are 104 . 106 visible, noticeable. On the left side of the radiator 12 is located for electrical contacting of the heating element 10 or the conductor tracks 14 . 16 a metallic punched grid 108 , This can, for example, in the radiator 12 be pressed, melted or injected. The punched grid 108 is for example by soldering, laser welding, clamping or pressing with the connection points 18 . 20 or the conductor tracks 14 . 16 electrically connected to the radiator 12 be able to supply power through a pluggable and, if necessary, repeatedly detachable electrical connection.

The tracks 14 . 16 are preferably by means of a thermal spraying process, in particular by means of a plasma spraying process, on the radiator 12 applied. In addition, if necessary, additional tracks, for example, with the radiator 12 welded, fused, glued or injected into this. The inner lining 92 is only for increased demands on the adapter 90 , as the description of the 8th were mentioned, necessary.

The 10 illustrates a plan view of the adapter 90 according to 8th , The punched grid 108 is from a preferably molded connector box 110 surrounded, which serves for receiving an electrical connector, not shown, as well as for electrical insulation. The plug box 110 is made to ensure a sufficient electrical insulation effect instead of the conductive material with an insulating material. The heating element can over it Be designed as an adapter without inner lining, as a connecting piece, as a sleeve, as a coupling, as a valve, distributor or as a ball valve.

The 11 shows a first embodiment of a heating element, which is designed as a soleplate for an iron.

The radiator 12 of the heating element 10 Here is the shape of a soleplate 120 for an iron, not shown in the drawings. The tracks 14 . 16 are slightly curved and run at a small distance to an approximately parabolic circumferential contour 122 the soleplate 120 , The tracks 14 . 16 run on an unspecified top of the soleplate 120 , the underside of the soleplate also not designated 120 , which is used to smooth the substance, facing away. Alternatively, the tracks 14 . 16 also along the tapered longitudinal edges of the soleplate 120 be applied. For contact protection, the live conductor tracks 14 . 16 optionally provided with an electrical insulation, for example with an insulating plastic. The electrical contacting of the conductor tracks 14 . 16 again by means of the connection points 18 . 20 ,

The soleplate 120 is suitable as a replacement for conventional metal soleplates and is characterized among other things by a low weight, a uniform and energy-efficient heat development and good native sliding properties. An additional sliding or non-stick coating made of PTFE which is otherwise necessary with metallic soleplates is generally no longer necessary. To secure against contact of live parts may optionally at least partially an electrical insulation of the soleplate 120 be provided for example with the insulating plastic. The low weight predestines the soleplate 120 especially for use in travel irons and also facilitates the handling of an iron equipped with it. The soleplate 120 can be manufactured inexpensively in large quantities, for example by injection molding, in particular, the introduction of recesses and / or holes, which are necessary for example for steam iron, made much easier to manufacture. The injection molding process also allows a high degree of design freedom and allows flat versions of the soleplate 120 , Due to the spatial design of the soleplate 102 , in particular by their material thickness, the specific electrical resistance can be adjusted exactly. In addition, the expression of the usual shearing of the molding compound in the shear zones near the tool wall has a great influence on the specific electrical resistance. Due to the self-regulating conductive material with the structurally predefined resistance level, usually no temperature control by means of a thermostat is necessary. Increased cooling, for example, by a point contact with cold material, are directly compensated, in particular local cooling is counteracted.

If guide plastic is used for the soleplate, then it must have sufficient mechanical pressure and dimensional stability at high temperatures of 200 ° C. or more, so that as a rule only high-temperature thermoplastics and / or thermosetting plastics are considered as matrix material. The regulation of the soleplate 120 Developed temperature can be easily achieved by the variation of the connection points 18 . 20 applied electrical voltage and the electrical current corresponding thereto.

The 12 shows a second embodiment of serving as a soleplate heating element with a larger number of interconnects. The as soleplate 124 serving radiators 12 of the heating element 10 is with a larger number of tracks 14 . 16 and connection points 18 . 20 Mistake. In the embodiment according to 12 are a total of five tracks 14 . 16 and correspondingly five connection points 18 . 20 on the soleplate 124 intended. The larger number of tracks allows the radiator 12 and with it the soleplate 124 to apply higher currents, leaving the soleplate 124 higher temperatures reached than the embodiment according to 11 , In addition, the regulation of temperature simplifies, since printed conductors 14 . 16 can be switched off or back in pairs with different polarity, so that no complicated electronic power control is necessary.

The 13 shows a cross section of a soleplate with adjusted height profile for a uniform heating power.

In contrast to the first two embodiments of soleplates in accordance with the 11 . 12 has the third embodiment of a sole plate 126 trained radiator 12 an approximately wedge-shaped cross-sectional geometry. The soleplate 126 has a two-component construction, wherein the radiator 12 with the known conductive material and an insulating region 128 is formed with a suitable insulating material. The heating element 10 points in the area of a sole tip 130 in relation to a sole end 132 a reduced material thickness. For example, a material thickness of the radiator at the bottom end 132 up to 2 cm, while the material thickness on the sole tip 130 only about 0.5 cm. The result is the wedge-shaped cross-sectional profile of the radiator 12 over an unspecified sole surface of the soleplate 126 away an approximately uniform heat dissipation.

The impingement of the radiator 12 with electricity via the two tracks 14 . 16 as well as the hereby electrically connected connection points 18 . 20 , the example here as a flat plug contacts 134 . 136 are designed. About the flat plug contacts 134 . 136 can the soleplate 126 via an easily detachable standard connector, such as tabs, optionally via an intermediate control and / or regulating device to an external electrical energy source, such as an on-board power system of a motor vehicle, aircraft or watercraft or to the public low-voltage network (230 volts, 50 Hz , AC). The two tabs 134 . 136 are in a plug box 138 received for receiving a connector plug, not shown.

The 14 illustrates a cross-sectional view through a filter in which a heating element according to the invention is integrated.

The filter 140 includes, among other things, a cup-shaped filter housing 142 , in the inside of a likewise pot-shaped ausgestaltetes heating element 10 with cup-shaped radiator 12 is arranged. Notwithstanding the embodiment shown, the shape of the radiator 12 also be annular or a different design of the filter housing 142 consequences.

The radiator 12 forms a cylindrical interior 142 for receiving a not shown, approximately cylindrical filter element. By means of the filter element, any fluid can be freed from unwanted accompanying substances. The impingement of the radiator 12 with electrical energy via annular circulating conductor tracks 14 . 16 that over in this embodiment as contact pins 22 . 24 executed connection points 18 . 20 be connected to an external power supply. The connection points 18 . 20 are in a plug box 144 summarized. The plug box 144 as well as the filter housing 142 can be made with an insulating plastic. The tracks 14 . 16 run on a surface 146 of the radiator 12 and enclose this ring. In an unmarked edge of the filter housing 142 is in a likewise not designated groove or a recess a sealant 148 , for example, an O-ring, inserted. By means of the sealant 148 and a lid 150 can the interior 142 be sealed pressure-tight. For secure attachment of the lid 150 on the filter housing 142 is a screw in the embodiment shown 152 intended. Instead of the screw connection 152 can also at least two snap hooks for a repeatable if necessary repeatedly releasable snap hook connection to the filter housing 142 be formed. Deviating sealing geometries, such as a conical seal, can also be molded integrally with.

The radiator 12 can in turn be made of the conductive plastic, while the filter housing 142 is preferably made with any insulating plastic. Both can be advantageously made in one piece in the multi-component injection molding process. Accordingly, the connector box 144 integral with the filter housing 142 to be sprayed on with. The radiator 12 can optionally be provided with a lining or inner lining to protect against chemically aggressive filter media. This inner lining can be formed by means of known painting processes or by film back-spraying.

The tracks 14 . 16 may in turn be provided by means of a thermal spraying process or by means of one of the production techniques already mentioned above. The same applies to the electrical connection between the tracks 14 . 16 and the connection points 18 . 20 or the contact pins 22 . 24 and their mechanical attachment within the filter housing 142 , The mechanical connection of the contact pins 22 . 24 For example, this can be done by placing them in the filter housing 142 firmly anchored. For this purpose, the contact pins 22 . 24 have multiple bends, whereby a tight fit in the surrounding insulating plastic can be achieved. The inventively heated filter 140 is particularly suitable for energy-efficient use in motor vehicles. Because the prevailing in this area standard DC voltage of 12 volts, 24 volts or 48 volts ensures sufficient heat generation under all operating conditions of a motor vehicle.

In the further progress of the description, the method for producing a heating element 10 with a radiator 12 in accordance with the method claim 8th be explained in more detail.

For the production of the heating element according to the invention 10 is in a process step a) first a radiator 12 preferably manufactured in an injection molding and / or extrusion process with a conductive material. In method step b) then the application of at least two conductor tracks takes place 14 . 16 on the radiator 12 by a thermal spraying method, in particular by plasma spraying according to DIN EN 657 , Other tracks can if necessary, by other methods, such as gluing, welding, pressing, riveting or screwing on the radiator 12 as well as by injection or encapsulation with the conductive material. In method step c), at least two electrical connection points are produced 18 . 20 for electrically contacting the at least two conductor tracks 14 . 16 , This can alternatively also in process step a) in the course of the injection molding of the radiator 12 , For example, by inserting pins in the mold done. The formation of the preferred metallic connection points 18 . 20 can also by gluing, welding, pressing, riveting or screwing on the radiator 12 as well as by injection or encapsulation with the conductive material and / or with the insulating material.

The representation according to the 15 . 16 . 17 and 18 is a basic version of the inventively proposed radiator for use as a heating element to remove.

15 shows a section through the heating element 10 , In the case 44 is the radiator 12 formed as a thermally regulating and electrically conductive material, via the conductor tracks 14 . 16 will be contacted. The tracks 14 . 16 turn stand with the pins 22 . 24 electrically conductive within the housing 44 into a socket 154 lead. The housing 44 is as an encapsulation of the tracks 14 . 16 , the radiator 12 as well as the contact pins 22 . 24 formed of an electrically insolating material. The electrical contacting of the conductor tracks 14 . 16 or the contact pins 22 . 24 takes place inside the socket 154 at one end of the housing 44 is executed.

16 shows a plan view of the front side of the housing 44 of the heating element 10 , Inside the socket 154 stand the two pins 22 . 24 sublime and are contacted by a corresponding complementary configured electrical connector. The representation according to 17 represents a section according to the section XVII-XVII in 15 , Out 17 shows that the tracks 14 . 16 over the inner contact pins 22 . 24 electrically contacted, wherein the contact pins 22 . 24 partially in the electrically conductive material, which is the radiator 12 represents embedded. 18 makes a section according to the sectional profile XVIII-XVIII in 15 represents. 18 shows that the electrical conductors 14 respectively 16 the radiator formed by the electrically conductive material 12 Contact each other.

The 19 and 20 show a variant of the heating element according to the invention used as steering wheel heating.

19 shows a steering wheel 156 which from a steering wheel back 158 is shown seen. In the steering wheel 156 is a steering wheel heater 157 integrated, which is represented by the proposed inventive heating element. Like the steering wheel back 158 shows, runs on the rim of the steering wheel, an electrical conductor 14 , via the contact pins or contact strips 22 . 24 is contacted, differing from an integrated connector 162 extend out. Elegantly, the contact pins extend 22 . 24 from the integrated plug 162 out through one of the spokes 160 of the steering wheel 156 , Through the contact pins 22 . 24 will be here on the steering wheel back 158 running electrical trace 14 electrically contacted. The conductor track 14 in turn is from the radiator 12 surrounded, which is, for example, an electrically conductive thermoplastic. This in turn is of a protective electrical layer having an electrical insulation properties and haptically appealing designed 166 envelops.

The representation according to 20 makes a cut according to the cutting pattern XX-XX in 19 dar. At the radiator 12 it is the electrically conductive material which the heating element 10 represents. This heating element 10 can either have a cavity 164 enclose. Instead of the cavity, it would also be conceivable to use an electrically insulating solid material or to select an overmolded core material. Like the sectional view according to 20 shows, are the two electrical conductors 14 . 16 each opposite each other, the steering wheel heating 157 representing, on the lateral surface of the here tubular designed heating element 12 , The two electrical conductors 14 . 16 are as shown in 20 from the electrical insulation properties having haptically appealing designed 166 Surrounded by protective layer.

The 21 and 22 show an alternative embodiment of the proposed heating element according to the invention, used as handle heating.

As 21 shows is on a handle 170 a handle heating 168 educated. 21 It can be seen that a here also analogous to the previously described steering wheel heating 157 tubular shaped radiator 12 , which is designed for example of an electrically conductive thermoplastic, via two electrical conductor tracks 14 . 16 is contacted. The tracks 14 . 16 be over the contact pins 22 . 24 electrically contacted, located at the front of the handle 170 into a socket 154 extend where they are by an appropriate complementarily configured mating connector are electrically contacted. The tracks 14 respectively 16 are in control 170 by an electrically insulating properties, haptically appealing designed protective layer 166 enclosed.

The representation according to 22 equals to 20 ,

In the 23 . 24 and 25 shows an embodiment of the present invention proposed heating element, which as contact surface heating 172 is designed. The contact surface heating 172 is between a first component 174 and a second component 176 added. About the heating element 10 can therefore both components 174 . 176 be heated. As 23 shows, includes the contact surface heating 172 the electrical conductors 14 and 16 as well as a flat plate in this embodiment radiator shown 12 , which is designed for example as an injection-molded electrically conductive thermoplastic. The two electrical conductors 14 . 16 be analogous to the above embodiments via the contact pins 22 . 24 electrically contacted. There is a possibility according to 24 one side of the plate-shaped radiator 12 with an electrical insulation properties, haptically appealing designed protective layer 166 to cover or even, as in 25 shown, this protective layer 166 Just leave it off and the tracks 14 . 16 opposite side of the radiator 12 as in 20 shown to be free.

26 is the settlement of a lateral surface of a cylindrically shaped heating element to take.

The heating element 10 according to 26 comprises a thermally regulating and electrically conductive thermoplastic 178 , which is representative here as a developed lateral surface of a cylindrical heating element 10 is shown. The thermally regulating and electrically conductive thermoplastic 178 is with electrical traces 14 . 16 Mistake. In the in 26 illustrated embodiment, the electrical conductors 14 . 16 as the first comb structure 180 and a second comb structure 182 educated. The two comb structures 180 respectively. 182 are in an offset 184 arranged on the lateral surface, with the "tines" of the comb structures 180 . 182 essentially - apart from the initial areas - may be formed in an identical length. The tines of the comb structures 180 . 182 that in the offset 184 are spaced apart with respect to the lateral surface, may have different lengths or an identical length, the offset 184 is selected depending on the application.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006032678 A1 [0009]
• DE 4429028 A1 [0011]
• DE 29722304 U1 [0014]
• DE 202010009208 U1 [0015]
• DE 3614141 D2 [0016]

Cited non-patent literature

• DIN 657 [0009]
• DIN 657 [0017]
• DIN 657 [0036]
• DIN EN 657 [0067]
• DIN EN 657 [0106]

Claims (12)

Heating element ( 10 ) with at least one thermoelectric heater ( 12 ), whereby the radiator ( 12 ) is at least partially formed with a conductive material and the radiator ( 12 ) via at least two tracks ( 14 . 16 ) is supplied with electrical energy, characterized in that the conductor tracks ( 14 . 16 ) by means of a thermal spraying process, in particular by plasma spraying according to DIN 657, are formed. Heating element ( 10 ) according to claim 1, wherein the conductive material is thermally self-regulating. Heating element ( 10 ) according to claim 1 or 2, wherein the conductor tracks ( 14 . 16 ) each having at least one electrical connection point ( 18 . 20 ), in particular with at least one contact pin ( 22 . 24 ), are electrically connected. Heating element ( 10 ) according to one of claims 1 to 3, wherein the radiator ( 12 ) has a substantially plate-shaped, a hollow cylindrical or a cup-shaped shape. Heating element ( 10 ) according to claim 4, wherein the radiator ( 12 ) at least partially with an assembled bulk material ( 72 ), in particular with sintered balls and / or with sintered granules, is formed from the conductive material. Heating element ( 10 ) according to one of claims 1 to 5, wherein at least one further electrical conductor, in particular at least one conductor track, on and / or in the radiator ( 12 ), in particular glued to this, welded, soldered or pressed and / or injected into this or the conductor during molding with the conductive material is encapsulated. Heating element ( 10 ) according to one of claims 1 to 6, wherein the radiator ( 12 ) at least one electrical insulation area ( 66 . 128 ) and / or at least one further component, wherein the insulating region ( 66 . 128 ) is formed with an electrical insulator, in particular with an insulating plastic. Method for producing a heating element, in particular a heating element ( 10 ) according to one of claims 1 to 7, with at least one thermoelectric heating element ( 12 ), whereby the radiator ( 12 ) is at least partially formed with a conductive material and the radiator ( 12 ) via at least two tracks ( 14 . 16 ) can be supplied with electrical energy, characterized by the following steps: a) producing a thermoelectric heating element ( 12 ) with a conductive material, b) applying the conductor tracks ( 14 . 16 ) on the radiator ( 12 ) by means of a thermal spraying method, in particular by plasma spraying according to DIN 657, and c) producing at least two electrical connection points ( 18 . 20 ) for electrically contacting the printed conductors ( 14 . 16 ). Method according to claim 8, wherein the at least two electrical connection points ( 18 . 20 ) are formed in process step a). Use of at least one heating element ( 10 ) according to one of claims 1 to 7 as a fluid line ( 50 . 56 . 70 ). Use of at least one heating element ( 10 ) according to one of claims 1 to 7 in a fluid functional unit, in particular in a fluid heater ( 30 ), in an adapter ( 90 ), in a nozzle, in a throttle, in a valve, in a distributor or in a filter housing ( 142 ) of a filter ( 140 ). Use of at least one heating element ( 10 ) according to one of claims 1 to 7 in a commodity, in particular in a steering wheel ( 156 ), a handle ( 170 ), as contact surface heating ( 172 ), Surfaces of a housing ( 44 ), a heating cartridge ( 153 ), Food warmer ( 80 ), in an iron, in particular as a soleplate ( 120 . 124 . 126 ), or in an accumulator, in particular in a housing ( 44 ) of a lead-acid battery ( 42 ).

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