HEATING-WIRE DEVICE AND METHOD FOR PRODUCING A HEATING-WIRE DEVICE

Abstract

A heating-wire device. The heating-wire device includes at least one heating wire, a heating region, which comprises the at least one heating wire embedded therein and can be heated by the heating wire; a current source, which is connected to the heating wire and is configured to apply a current to the heating wire and heat it; a controller, using which the current source can be controlled; a first adhesion-promoting layer, which is arranged on a surface of the heating wire and surrounds the surface thereof, wherein the heating region surrounds the first adhesion-promoting layer.

Claims

1. A heating-wire device, comprising: at least one heating wire; a heating region which includes the at least one heating wire embedded therein, the heating region being heatable by the heating wire; a current source, which is connected to the heating wire and is configured to apply a current to the heating wire and heat it; a controller configured to control the current source; a first adhesion-promoting layer arranged on a surface of the heating wire and surrounding the surface of the heating wire, wherein the heating region surrounds the first adhesion-promoting layer.

2. The heating-wire device as recited in claim 1, further comprising a sheath and a second adhesion-promoting layer, wherein the sheath surrounds the first adhesion-promoting layer and the second adhesion-promoting layer surrounds the sheath, wherein an outer region of the heating region is applied to the sheath so as to embed it therein.

3. The heating-wire device as recited in claim 2, wherein the first adhesion-promoting layer and/or the second adhesion-promoting layer includes silane.

4. The heating-wire device as recited in claim 2, wherein the sheath includes an enameled coating or a polymer.

5. The heating-wire device as recited in claim 2, wherein a first coefficient of thermal expansion of the first adhesion-promoting layer is adjusted to a second coefficient of thermal expansion of the sheath, wherein the first coefficient of thermal expansion and the second coefficient of thermal expansion differ from one another by less than a predetermined first variation value.

6. The heating-wire device as recited in claim 2, wherein a second coefficient of thermal expansion of the sheath is adjusted to a third coefficient of thermal expansion of the second adhesion-promoting layer, wherein the second coefficient of thermal expansion and the third coefficient of thermal expansion differ from one another by less than a predetermined second variation value.

7. A method for producing a heating-wire device, comprising the following steps: providing at least one heating wire; embedding the heating wire in a heating region, wherein a first adhesion-promoting layer is arranged on a surface of the heating wire and surrounds the surface of the heating wire, wherein the heating region surrounds the first adhesion-promoting layer; providing a current source, which is connected to the heating wire and is configured to apply a current to the heating wire and heat it; and providing a controller configured to control the current source.

8. The method as recited in claim 7, wherein an outer region of the heating region is applied to a sheath around the first adhesion-promoting layer so as to embed it therein.

9. The method as recited in claim 7, wherein the first adhesion-promoting layer is melted at least in some regions when it is arranged on the surface of the heating wire.

10. The method as recited in claim 7, wherein the sheath is sprayed onto the first adhesion-promoting layer and a second adhesion-promoting layer is applied to the sheath, wherein the second adhesion-promoting layer is melted at least in some regions when it is arranged on the sheath and wherein an outer region of the heating region is applied to the second adhesion-promoting layer so as to embed it therein.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention is explained in greater detail in the following with reference to the exemplary embodiments set out in the schematic figures.

[0036] FIG. 1 is a schematic view of a heating-wire device according to an exemplary embodiment of the present invention.

[0037] FIG. 2 is a schematic view of a heating-wire device according to a further exemplary embodiment of the present invention.

[0038] FIG. 3 is a block diagram of method steps of the method for producing a heating-wire device according to an exemplary embodiment of the present invention.

[0039] In the figures, identical reference signs denote identical or functionally identical elements.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0040] FIG. 1 is a schematic view of a heating-wire device according to an exemplary embodiment of the present invention.

[0041] The heating-wire device 10 comprises at least one heating wire 1, in particular, according to FIG. 1, three heating wires extending in parallel, a heating region 2, which comprises the heating wires 1 embedded therein and can be heated by the heating wires 1; a current source SQ, which is connected to the heating wires 1 and is configured to apply a current to the heating wires 1 and heat them; a controller SE, using which the current source SQ can be controlled; a first adhesion-promoting layer (not shown), which is arranged on a surface of the relevant heating wire 1 and surrounds the surface thereof, wherein the heating region 2 surrounds the first adhesion-promoting layer. In this case, the heating region 2 can comprise a surface OS which can be heated.

[0042] The adhesion-promoting layer can also be formed as a stress equalization layer and a corresponding coating. The heating wire 1 can comprise a metal material, for example, steel, steel alloys, copper, or other materials, and can therefore cover many areas of application, depending on the requirements.

[0043] The heating region 2 can, for example, comprise an enameled coating or a polymer, which can have sufficient ductility to ensure or approximate a temperature equalization.

[0044] Furthermore, the material can be tailored to the adhesion promoter (the probability of the adhesion promoter being removed by the coating, for example the sheath or the outer region, can then be reduced). The coating thickness can be determined on the basis of the heat conduction and can be synchronized with the material using which encapsulation can then be carried out. The aim is to easily melt the adhesion promoter in order to ensure a good connection.

[0045] The coated heating wire (which is coated with the adhesion promoter) can be used in a heated cover or radome for radar sensors. These may be radomes with an open installation as well as heatable design panels. Wires of this kind can then likewise be used in any sensors or actuators in which heating wires are embedded in plastics material. These benefits can be utilized when laying the wire.

[0046] A winding carrier (plastics carrier having a wire wound thereon) can be encapsulated in a further injection-molding process. The injection-molding compound then sheathes everything. An alternative method would be hot stamping, in which a heated wire is sealed into plastics material. The coating thickness can be a design parameter for controlling ductility or for increasing the surface area (a greater diameter of the wire and sheath reduces the energy density at the transition from the wire to the plastics matrix).

[0047] FIG. 2 is a schematic view of a heating-wire device according to a further exemplary embodiment of the present invention.

[0048] The heating-wire device 10 in FIG. 2 can be similar to that in FIG. 1, although, in addition to embedding the heating wire through the heating region, a sheath UH can be provided between a first adhesion-promoting layer HS1 and a second adhesion-promoting layer HS2. The heating-wire device 10 can thus comprise a sheath UH and a second adhesion-promoting layer HS2, wherein the sheath UH surrounds the first adhesion-promoting layer HS1 and the second adhesion-promoting layer HS2 surrounds the sheath, wherein an outer region of the heating region 2 can be applied to the sheath UH so as to embed it therein. The two adhesion-promoting layers, the sheath, and the outer region can constitute the heating region together or in part.

[0049] By way of the first and/or the second adhesion-promoting layer, the requirements for promoting adhesion and decreasing stresses can be met in combination by one material.

[0050] The adhesion-promoting layers can counteract delamination and can provide a good and similar flow of heat in the heating wire, adhesion-promoting layer, and sheath(s). A first coefficient of thermal expansion (of the first adhesion-promoting layer) and a second coefficient of thermal expansion (of the sheath) can differ from one another by less than a predetermined first variation value. The second coefficient of thermal expansion of the sheath UH can be adjusted to a third coefficient of thermal expansion of the second adhesion-promoting layer HS2, wherein the second coefficient of thermal expansion and the third coefficient of thermal expansion can differ from one another by less than a predetermined second variation value.

[0051] FIG. 3 is a block diagram of method steps of the method for producing a heating-wire device according to an exemplary embodiment of the present invention.

[0052] In the method, at least one heating wire is provided S1, the heating wire is embedded S2 in the heating region, wherein a first adhesion-promoting layer is arranged on a surface of the heating wire and surrounds the surface thereof, wherein the heating region surrounds the first adhesion-promoting layer; a current source is provided S3, which is connected to the heating wire and is configured to apply a current to the heating wire and heat it; and a controller is provided S4, using which the current source can be controlled.

[0053] Although the present invention has been described in full above on the basis of the preferred exemplary embodiment, it is not limited thereto, but instead can be modified in various ways.