Corrugated fin element

Abstract

The invention relates to a method for producing a corrugated fin element for a heating register or for another heating device, through which corrugated fin element a flow can pass, to a corrugated fin element produced according to such a method, and to a heating register designed with such corrugated fin elements, wherein the corrugated fin elements are produced by unfolding.

Claims

1. A method for producing a corrugated fin element, wherein the corrugated fin element comprises a plurality of corrugated fins of wave-shaped design, the method comprising: producing a base element having apexes of the plurality of corrugated fins that are in contact with adjacent apexes or are arranged at a distance to the adjacent apexes substantially smaller than a breadth of one of the apexes, impacting the base element with a tensile force so as to pull the base element apart such that a distance between the adjacent apexes is increased by deformation and a total length of the corrugated fin element increases relative to the base element, wherein in the base element, swages are formed in lamella legs joining the apexes; and after impacting the base element with the tensile force, impacting the apexes with a pressing force transversely to a longitudinal extension of one of (1) the base element or (2) the corrugated fin element.

2. The method according to claim 1, wherein a distance between the adjacent apexes after deformation is a multiple of the breadth of the one of the apexes.

3. The method according to claim 2, wherein the distance between the adjacent apexes after deformation is at least 5-fold of the breadth of the one of the apexes.

4. The method according to claim 1, wherein the pressing force is chosen such that the apexes are flattened or leveled.

Description

(1) A preferred example will be explained in detail in the following by means of schematic drawings. There show:

(2) FIG. 1 a schematic diagram of a heating register with a plurality of corrugated fin elements;

(3) FIG. 2 a three-dimensional illustration of a corrugated fin basic element for the production of a corrugated fin element pursuant to FIG. 1;

(4) FIG. 3 an enlarged partial representation of the basic element of FIG. 1;

(5) FIG. 4 an illustration for explaining the method for producing a corrugated fin element in accordance with the disclosure; and

(6) FIG. 5 a corrugated fin element produced in accordance with such a method for a heating register pursuant to FIG. 1.

(7) FIG. 1 shows a side view of a heating register 1 as it is, for instance, used for heating an airflow. This heating register 1 has a frame 2 in which four heating elements 4, 6, 8, 10 are inserted. Each heating element has, for instance, PTC resistance elements 12 which are each controllable via electric contacts 14, 16 (current supply, mass). The actual electrical contacting may, for instance, take place via contact sheets which are in operative electrical connection with the PTC components. Like in the illustrated embodiment, the electrical contacting may take place via the contact sheets and via corrugated fins.

(8) It is to be understood that, instead of the PTC resistance elements 12, also heating elements of different construction may be used.

(9) Pursuant to the illustration in FIG. 1, each heating element has two corrugated fin elements 18 which are arranged at both sides of the PTC resistance elements 12 and which are in thermal (and also electrical) contact with the PTC resistance elements 12 and transfer the heat given off by them to the air flowing through the heating register 1 perpendicularly to the drawing plane. The construction of heating registers 1 of this kind is known, so that further explanations are dispensable.

(10) FIG. 2 shows a corrugated fin basic element 20 from which the corrugated fin elements 18 incorporated in the heating register 1 are formed. Such a basic element 20 corresponds substantially to the corrugated fin elements as they are disclosed in the initially mentioned state of the art pursuant to DE 10 2013 108 357 A1. Accordingly, such a basic element 20 has a plurality of corrugated fins 22, 24 bent from a metal strip in a meandering pattern, the apexes 26, 28 of which corrugated fins are, in the illustration pursuant to FIG. 2, in flush contact or else are arranged at a comparatively small distance to each other, which is distinctly smaller than the breadth d of an apex.

(11) As may be taken from the enlarged detailed illustration pursuant to FIG. 3, each apex 26, 28 turns into lamella legs 30, 32 which are positioned in a V-shape with respect to each other, wherein this V closes away from the associated apex 26 to the other apex 28. In each lamella leg 30, 32 swages are formed, in the illustrated embodiment three swages 34, 36, 38 positioned side by side, which are formed by stamping and bending during the production of the basic element 20. The two outer swages 34, 38 are shaped inwardly, toward the opposite lamella leg 30, while the middle swage 36 is shaped to the right, toward the adjacent corrugated fin. It is to be understood that another swage geometry or a different number of swages may also be used. Due to these swages the corrugated fin 22, 24 is stiffened distinctly as compared to swage-free corrugated fins, so that the transportation of the deformed basic elements 20 from the bending tool to the following processing step is improved due to the increased stiffness.

(12) With respect to further details, reference is made to DE 10 2013 108 357 A1 for reasons of simplification.

(13) The basic element 20 formed this way with alternatingly contacting corrugated fins 22, 24 is thenas illustrated in FIG. 4processed in a further production step to the corrugated fin element 18, as it is incorporated in the heating register 1. In this process, preferablylike in DE 10 2013 108 357 A1the rounded apexes 26, 28 are impacted with a pressing force P (see FIG. 4 top). This pressing force P acts transversely to the longitudinal extension of the basic element 20. By this pressing force P it is achieved that the originally rounded apexes 26, 28 are flattened (leveled), as illustrated in FIG. 4 at the bottom. This leveling may, for instance, take place by a pressing tool impacting a plurality of apexes 26, 28 simultaneously with the pressing force P.

(14) Following this flattening, the basic element 20 is impacted with a tensile force F pursuant to the illustration in FIG. 4 at the top. For this purpose, elements transferring the tensile force engage the basic element 20 at holding regions 40, 42 which are indicated in dots and dashes, so as to pull the basic element 20 apart, as illustrated in FIG. 4, so that the corrugated fin angle which is negative in the basic condition is widened such that the corrugated fin angle between the lamella leg 30, 32 is quasi inverted. The result of this is that the lamella legs 30 spread, for instance, from the top apex 26 to the next apex 28 positioned there beneath. This widening resulting from a plastic deformation of the basic element 20 leads to it that the total length is distinctly increased as compared to the total length of the basic element 20. In the illustrated example the distance D between two adjacent apexes is, for instance, a multiple, for example more than the 5-fold, of the breadth d of an apex. In the basic element 20 the distance D is almost zero since the corrugated fins 22, 24 are in contact with each other along their apexes 26, 28.

(15) It has turned out surprisingly that the method according to the disclosure, i.e. first of all producing a basic element 20 with an almost conventional structure and then widening this basic element 20, provides a corrugated fin element 18 which can be produced with high precision with a predetermined apex distance D. A corrugated fin element 18 of this kind stands out by a comparatively great stiffness while being very easy to produce.

(16) It has further turned out that the leveling eliminates the risk of drawing in, in which, for instance, the upper apex 26 arranged in FIG. 4 between two lower apexes 28 is drawn in and curves inward toward the two other apexes 28.

(17) The method in accordance with the disclosure may be performed with basic elements cut into lengths, but also with a basic element strand formed as an endless tape, in which case cutting into lengths will then take place in a further processing step.

(18) In deviation from the above-described proceeding it is also possible, as indicated in dashes in FIG. 4 at the bottom, to apply the pressing force P for flattening (leveling) the apexes 26, 28 in a process step following the unfolding by the force F.

(19) By means of the leveling it is, apart from the stiffening, also achieved that a good contact face for adjoining elements, such as PTC resistance elements 12 or contact sheets, is provided.

(20) Alternatively it is also possible to completely omit the process step of leveling.

(21) FIG. 5 shows a three-dimensional illustration of the corrugated fin element 18 produced by the unfolding of a basic element. In this illustration one recognizes the apexes 26, 28 flattened by leveling and the lamella legs 30, 32 positioned at a comparatively large V-angle . This angle is, for instance, more than 30. In the concrete example it is approximately 40.

(22) The disclosure relates to a method for producing a corrugated fin element for a heating register or for another heating device, through which corrugated fin element a flow can pass, to a corrugated fin element produced according to such a method, and to a heating register designed with such corrugated fin elements, wherein the corrugated fin elements are produced by unfolding.

LIST OF REFERENCE NUMBERS

(23) 1 heating register 2 frame 4 heating element 6 heating element 8 heating element 10 heating element 12 PTC resistance element 14 contact 16 contact 18 corrugated fin element 20 corrugated fin basic element (can also be called base element) 22 corrugated fin 24 corrugated fin 26 apex 28 apex 30 lamella leg 32 lamella leg 34 swage 36 swage 38 swage 40 holding region 42 holding region