Electric heating device and method for its manufacture

Abstract

An electrical heating device comprising: a housing (100) with a partition (108) that divides a connection chamber (112) from a heating chamber (110) for heat dissipation and from which at least one receiving pocket (116) projects into the heating chamber (110) as a heating fin (114), in which a PTC heating device (2) with at least one PTC element (12) and conductive traces (10) electrically connected to the PTC element (12) with opposite polarity for energizing it and which are electrically connected in the connection chamber (112) are received, wherein the PTC element (12) and at least one of the conductive traces (10) are received in a heater housing (4), wherein the heater housing (4) is pressed into the receiving pocket (116) by plastic deformation of the heater housing (4) and / or the receiving pocket (116), characterized in that the heater housing (4) with the receiving pocket (116) is materially bonded and preferably cold-welded.

Description

[0001] The present invention relates to an electric heating device with a housing comprising a partition wall that divides a connection chamber from a heating chamber for heat dissipation. At least one receiving pocket, projecting into the heating chamber as a heating fin, extends from the partition wall. A PTC heating element is provided in this pocket. Furthermore, a pressure element is received in the pocket, which holds the heat-dissipating surfaces of the PTC element against opposing inner surfaces of the receiving pocket.

[0002] The PTC heating device has at least one PTC element and conductive traces attached to it. These traces are electrically connected to the PTC element. This connection can be a form-fit, force-fit, and / or material-fit connection.

[0003] The aforementioned general features of the electric heating device apply to the prior art according to EP 1 872 986 A1. They also apply to the implementation of the invention.

[0004] The earlier proposals EP 2 637 474 A1 and EP 2 337 425 A1, both originating from the applicant, each disclose PTC heating devices that are placed in a previously mentioned receiving pocket.

[0005] EP 2 337 425 A1 discloses a solution in which a conductor track adjacent to a main side surface of the PTC element is provided as a sheet metal piece with contact projections bent out of the plane of the sheet metal piece. The contact projections serve solely to improve the electrical contact of the PTC element.

[0006] In the previously described, known solutions, the receiving pocket tapers towards its lower, closed end. Accordingly, the insertion opening, which opens towards the connection chamber, is wider than the lower, closed end of the receiving pocket. The PTC elements and the contact plates on both sides are typically clamped in place within the receiving pocket by a wedge-shaped pressure element, with at least one insulating layer interposed between the conductor tracks and the opposing inner surfaces. This wedge element ensures that the layers of the layer structure are clamped against each other within the receiving pocket. These layers consist of at least the PTC elements and the conductor tracks extending perpendicular to the direction of force exerted by the wedge element (usually contact plates), as well as at least one insulating layer.

[0007] Despite the downwardly tapered cross-sectional shape of the receiving pocket, necessitated by manufacturing processes, the wedge element is designed to facilitate efficient heat transfer, preferably between the two opposing heat dissipation surfaces of the PTC element and their respective corresponding inner surfaces of the receiving pocket, with the pressure element interposed. The pressure generated there also presses the opposing heat dissipation surface of the PTC element directly against the opposite inner surface of the receiving pocket, either directly or via an insulating layer.

[0008] CN 109028554 A discloses an electric heating device with the features of claim 1. In this prior art, the PTC heating device comprises a pocket-shaped heater housing having opposing side sections connected to each other via a bottom section, and which accommodates the PTC element and the conductive traces. The pocket-shaped heater housing accordingly forms a receptacle, at least for the PTC heating element. The pocket-shaped heater housing has a wedge-shaped cross-section to enable uniform thermal contact between the heater housing, which is designed as a pressure element, and the inner surfaces of a receiving pocket that tapers towards its lower end, the end facing away from the connection chamber.

[0009] The previously presented prior art solutions all ensure good heat dissipation. However, the problem is that the mounting pocket does not always correspond to the intended shape due to manufacturing tolerances. This is because the PTC elements are subject to considerable dimensional variations due to the manufacturing process. Furthermore, it is not always guaranteed that the heat dissipation surfaces of the PTC element are perfectly straight and flat.

[0010] Pressing in a wedge as a pressure element can lead to stress peaks that can cause the ceramic PTC element or a ceramic insulating layer within the mounting pocket to break. Depending on tolerances, the wedge element used as a pressure element in the prior art may not be thick enough in the specific application, so that it essentially sits ineffectively at the lower end of the mounting pocket. Conversely, if the clearance remaining before inserting the wedge element is too small, there is insufficient coverage of the heat dissipation surface of the PTC element in the vertical direction of the mounting pocket, i.e., between the lower end and the insertion opening. As a result, the PTC element overheats and prevents further power current absorption. Consequently, the efficiency of the PTC element is poor.

[0011] It is also possible that layers of the PTC heating element and / or the pressure element, or the PTC heating element as a whole, may be pushed out of the receiving pocket or migrate out due to vibrations.

[0012] The present invention aims to at least partially solve the aforementioned problems.

[0013] The present invention proposes an electric heating device having the features of claim 1.

[0014] In the heating device according to the invention, the receiving pocket projects into the heating chamber as a heating fin in a manner known per se. The receiving pocket is typically formed as a single piece on the partition wall. It is usually made of a highly thermally conductive material, generally metal. The receiving pocket, either on its own or in conjunction with the partition wall, can be manufactured by deep drawing or casting of a metal. Preferably, the receiving pocket is made of aluminum and is formed as a single piece on the partition wall by a forming process, particularly deep drawing.

[0015] The receiving pocket – like the receiving pocket known from the prior art – preferably has a wedge-shaped cross-sectional form, which tapers towards the bottom of the receiving pocket, i.e. the end of the heating fin projecting into the heating chamber.

[0016] According to the invention, the heater housing is accommodated in this receiving pocket. The heater housing typically completely encloses the PTC element and at least the majority of its conductive traces. In particular, the main side surfaces of the PTC element are usually covered by the heater housing. In the assembled state, the heat-dissipating main side surfaces of the PTC element are arranged opposite the side surfaces of the heating fin, so that heat can be extracted from the PTC element in a direction perpendicular to the main side surfaces, conducted through the receiving pocket, and dissipated to the heating chamber via the side surfaces. The heater housing is located within this heat conduction path.

[0017] The heater housing is typically made of a material with good thermal conductivity. In particular, the heater housing is made of a flowable material, such as copper or aluminum, which has relatively low strength but good thermal conductivity. The heater housing can also be made of a plastic highly filled with thermally conductive particles. The volumetric fill level of the thermally conductive particles should be at least 60 percent by volume.

[0018] The heater housing not only contains the PTC element and, for the most part, the conductive traces. Typically, there is also at least one insulating layer between the PTC element and an inner surface of the heater housing. This insulating layer can be made of an electrically insulating material, particularly a plastic or ceramic. The insulating layer usually covers the conductive trace that is directly in electrical contact with the PTC element on the outside, so that this polarity does not directly contact the inner surface of the heater housing.

[0019] On the opposite side, the current can be supplied directly through the heater housing, which in this case forms the conductor track. However, two conductor tracks, each with a different polarity, are usually housed as separate components within the heater housing and each electrically insulated from the housing by an insulating layer. These insulating layers, parallel to the opposing main faces of the PTC element, can consist of a single film wrapped around the underside of the PTC element. The PTC element can be held in a positioning frame made of an electrically insulating material, which positions and distances the PTC element(s) from one another. By positioning the frame within the heater housing, a predetermined orientation and arrangement of the PTC element(s) within the mounting pocket is achieved.This positioning frame can be covered on the outside with insulating layers or surrounded by a single insulating layer.

[0020] According to the present invention, the heater housing is pressed into the receiving pocket by plastic deformation of the heater housing and / or the receiving pocket. The heater housing and / or the receiving pocket can have opposing main sides or inner surfaces that are inclined to each other at an angle of between 2° and 5°.

[0021] During assembly, the heater housing is typically first fitted with the components it contains, i.e., the PTC element, the at least one conductor track, and any insulating layer. The heater housing is then inserted into the receiving pocket. Plastic deformation then takes place. For example, the heating fin can be plastically deformed by a deformation tool acting directly on the fin. Alternatively, or additionally, a deformation tool can act against the heater housing to effect the plastic deformation according to the invention from the inside of the receiving pocket. In any case, the deformation results in a close, plastically deformed bond between the heater housing and the inner surface of the receiving pocket.Furthermore, due to the deformation of the heater housing and / or mounting pocket, the PTC element is firmly, in particular vibration-resistant and with good heat conductivity, positioned in the heat path between the PTC element and the side surface of the heating fin.

[0022] In the previously described designs, in addition to vibration-resistant mounting of the PTC element in the mounting pocket, good heat dissipation is achieved, and the mounting pocket is typically completely or almost completely filled by the components, at least in the area of ​​the mounting pocket that is particularly important for heat dissipation from the PTC element. Thus, the lower part of the mounting pocket is usually fully connected to the heater housing. Full-surface contact is also achieved between the main side faces of the PTC element and the corresponding inner surfaces of the mounting pocket, resulting in good heat dissipation from the PTC element to the side faces of the heating fin. The heat conduction discussed here focuses particularly on the heat path from the main side faces to the side faces of the heating fin.The end faces of the PTC element, due to their smaller dimensions, typically contribute only a minor amount to heat dissipation. The main faces are usually those surfaces with the greatest extent in the longitudinal and / or lateral directions of the PTC element. The end faces connect these main faces. The PTC element is typically cuboidal and has a significantly greater extent in the longitudinal and / or lateral directions than in the vertical and / or horizontal directions. The thickness is typically at least five times smaller than either of the longitudinal and / or horizontal dimensions. The main face is thus defined by these two extents in the longitudinal and horizontal directions.

[0023] According to a preferred embodiment of the present invention, the heater housing is connected to the receiving pocket by a material bond, particularly as a result of plastic deformation, and especially preferably by cold welding. In this preferred embodiment, the plastic deformation of the heater housing and / or receiving pocket must be carried out in such a way that a material bond, in particular formed by welding, results between the heater housing and the receiving pocket.

[0024] An end face extending substantially transversely in the insertion direction of the PTC element can be positioned adjacent to the bottom of the receiving pocket. Typically, at least after plastic deformation, material from the heater housing is located between the bottom of the receiving pocket and this end face. The opposite end face, extending parallel to this, is adjacent to the connection chamber and usually contributes little to heat dissipation. The end faces of the PTC element, extending perpendicular to these two end faces, can be exposed within the receiving pocket without a direct heat-conducting surface. This is preferable for reasons of good electrical insulation.The mounting pocket is typically filled with an electrically insulating compound after the heater housing has been inserted and shaped. This compound prevents air currents and leakage currents and can be located between an end face of the heating fin and the corresponding end faces of the PTC element, allowing some heat to be transferred to the outer surface of the heating fin via this insulating compound. The highly thermally conductive compound could, for example, be a curing silicone compound to which electrically non-conductive, but highly thermally conductive particles have been added. These particles could be aluminum oxide spheres.

[0025] The following analysis refers in particular to a cross-sectional view through the PTC element, intersecting the upper and lower end faces and extending parallel to the edge end faces of the PTC element. In such a cross-sectional view, at least one surface of the heater housing that abuts the receiving pocket is convex. This shape of the heater housing may refer to the state before deformation. However, such a convex shape typically also results in a deformed state, in which the heater housing abuts the inner surface of the receiving pocket with a convex surface. In this case, the inner pocket may have become concave outwards as a result of deformation of the heater housing, corresponding to the convex shape of the heater housing.

[0026] According to a preferred embodiment of the present invention, at least one fixing lip on the heater housing is formed by an undercut. This fixing lip is plastically deformed, at least partially, by pressing the heater housing into the receiving pocket and is pressed against the inside of the receiving pocket. This embodiment is based on the consideration that a fixing lip that deforms easily forms a kind of barb or the like, which, at least after the plastic deformation, can provide improved anchoring of the heater housing in the receiving pocket. The fixing lip can be positioned at any point in the vertical direction, i.e., the direction in which the heater housing is inserted into the receiving pocket.However, with a view to achieving the best possible heat dissipation between the main side surfaces and the heating fin, it is preferable to place the corresponding fixing lip close to the bottom of the receiving pocket.

[0027] In this regard, the present invention proposes providing the heater housing with two legs and an associated heater housing base. The heater housing forms a substantially U- or V-shaped receiving space for the PTC element and the at least one conductor track, the inner walls of which can be aligned parallel to each other. The aforementioned fixing lip is provided on at least one, preferably two, legs, with the at least one fixing lip being located in the area of ​​the heater housing base. By definition, the base is the area that lies in front of the PTC element in the insertion direction of the heater housing into the receiving pocket.

[0028] According to a preferred embodiment of the present invention, the heater housing has a contact surface at a rear end (in the direction of insertion) adapted for the application of a pressing tool. This contact surface can be formed by a substantially flat surface extending transversely to the direction of insertion. Alternatively, the contact surface can be formed by a trough-shaped recess. The contact surface is adapted for the application of a pressing tool. This pressing tool typically acts on the heater housing from the connection chamber to compress the heater housing in the receiving pocket, in particular to plastically deform it and thus cold weld it in the receiving pocket. This generally occurs when the heater housing is inserted into the receiving pocket.

[0029] According to a further development of the present invention, the heater housing can have at least one inwardly directed locking projection. In the finished product, this locking projection typically lies flat against the PTC element, for example, against the insulating layer. The locking projection can act like a barb, preventing the PTC element from unintentionally being detached from the heater housing, which may be open at the top. After the plastic deformation of the heater housing, this locking projection may essentially be integrated into a flat contact surface that extends parallel to a main side surface of the PTC element and, for example, forms a contact surface for the insulating layer.

[0030] The aforementioned heater housing can be manufactured as an elongated material by means of extrusion or sizing and subsequently cut to length, so that its length essentially corresponds to the width of the PTC element.

[0031] The present invention further discloses a method for manufacturing an electric heating device of the type mentioned above. In this method, the PTC element, with at least one conductive track and optionally with the aforementioned insulating layer, is inserted into a heater housing and into the receiving pocket. The heater housing can first be populated with the elements contained therein and then inserted into the receiving pocket. Alternatively, the heater housing can first be inserted into the receiving pocket and then populated.

[0032] In any case, according to the inventive method, during the insertion of the heater housing or after the insertion of the heater housing and the components received therein, the heater housing is pressed into the receiving pocket under plastic deformation and preferably cold-welded to the receiving pocket.

[0033] Preferably, in the invention, when inserting the heater housing into the receiving pocket, preferably after the heater housing has been fitted with the components, a heater housing base is plastically deformed in the base of the receiving pocket.

[0034] According to a preferred embodiment of the present invention, in which the heater housing is first fitted with the aforementioned components and then inserted into the receiving pocket, the heater housing is gripped by an insertion tool. Typically, opposing legs of the heater housing are gripped by the insertion tool and pivoted towards each other. The insertion tool then applies elastic and / or plastic deformation to the heater housing before it is inserted into the receiving pocket, pressing it against the PTC element. This contact can be made directly against the PTC element or with an insulating layer or the contact plate interposed.Typically, in this method, the previously mentioned inward-facing locking projection of the heater housing is plastically deformed, so that a flat counter-surface is formed on both main sides of the heater housing for the PTC element, against which the PTC element rests directly or indirectly with the contact plate and / or insulating layer in between.

[0035] Further details and advantages of the following invention will become apparent from the subsequent description of an exemplary embodiment in conjunction with the drawing. In this drawing Fig. 1 a perspective side view of an embodiment of an electric heating device with the housing partially removed; Fig. 2 a cross-sectional view of the in Fig. 1 with reference numeral 102marked housing base with a first variant of a heater housing, which is pressed into a receiving pocket Fig. 3 a perspective sectional view of the recording pocket with a second variant of a heater housing before it is fully inserted into the recording pocket; Fig. 4 a perspective sectional view of the recording pocket with a third variant of a heater housing before it is fully inserted into the recording pocket; Fig. 5 a perspective sectional view of the recording pocket with a fourth variant of a heater housing before being fully inserted into the recording pocket; Fig. 6 a perspective sectional view of the recording pocket with a fifth variant of a heater housing before it is fully inserted into the recording pocket and Fig. 7 the exemplary embodiment according to Fig. 6 in a side view with complete heating fin.

[0036] The Fig. 1 shows a case 100 an electric heating device that is a floor element 102 , a case base 104 and a case cover 106 includes. In the illustrated embodiment, the housing base forms 104 one parallel to the case bottom 102 extending partition wall 108 from which a circulation or heating chamber 110 from a connecting chamber 112 separates. In the illustrated embodiment, at least the housing base is 104 Made from a single piece of aluminum. From the partition wall 108 protruding heating fins 114 towards the heating chamber 110 These heating fins taper conically towards their fine end at an angle of approximately 2.5° and form a receiving pocket. 116 with opposing inner surfaces 118 out. The inside of the heating fin 114and the adjoining chamber 112 is fluidically from the heating chamber 110 separated.

[0037] To the heating chamber 110 lead to opposite end faces of the housing base. 104 Connections. These connections are hose or pipe connection fittings. 120 shaped and protrude outwards from the actual wall of the housing base 104 They serve to connect hoses or pipes that carry the liquid fluid to be heated, which is located in the heating chamber. 110 to be heated.

[0038] These include the recording pockets. 116 each with PTC heating elements 2 equipped. Into the individual recording pockets 116 can one or more of these PTC heating devices 2 in the longitudinal direction of the heating fins 114 be used one after the other.

[0039] The essential structure of the PTC heating device 2The PTC heating element is essentially identical for the variants discussed below. 2 Each has a heater housing. 4 , which opposite thighs 6 includes those with a heater housing base 8 are connected to each other in a pivotable manner. On the heater housing base 8 The heater housing is on the opposite side. 4 open. It is usually held in place by contact plates. 10 towers above, which is electrically conductive and directly attached to a PTC element 12 to be fitted and formed in one piece by stamping and bending the contact plates 10 Formed connecting tabs made from sheet metal material 14 as contact tongues for the plug-in connection of the PTC heating element 2 train. These connecting flags 14 are in Fig. 2 shown. In the remaining illustrations according to the Fig. In sections 3 ff., the details of the connecting flags were omitted.

[0040] As the section view according to Fig. The PTC element is located at point 2. 12 in a fully enclosed recording of a position frame 16 made of insulating material, of which in Fig. 1 only the upper and lower frame rails 18 , 20 They are recognizable. The PTC element usually protrudes above. 12 in the thickness direction, i.e., one thickness direction of the receiving pocket 116 , the frame rails 18 , 16 , so that the electrically conductive arrangement of the contact plates 10 on the PTC element 12 through the positioning frame 16 is not affected.

[0041] On the PTC element 12 On the opposite side lies an insulating layer. 22 on the outside of the contact plates 10 on. This insulating layer 22 It is formed in one piece and wraps around the underside of the positioning frame. 16 .

[0042] The previously described elements of the PTC heating device 2 are in the heater housing 4 The heater housing is made of aluminum, produced by extrusion and cut to length. The width of this heater housing... 4 This corresponds approximately to the width of the PTC element. 12 The width direction extends perpendicular to the representation plane. Fig. 2. The additional dimension of the PTC element, which can be seen here besides the thickness. 12 This is the length. This extension roughly corresponds to the insertion direction of the PTC heating element. 2 into the recording bag 116 .

[0043] The in Fig. 2 right thighs 6 of the heater housing 4 is thicker than the left leg and has a contact surface extending essentially transversely to the insertion direction. 26, which are flat and extend across the width of the heater housing 4 is continuously formed above this installation area. 26 The right thigh is also affected. 6 like the left thigh 6 formed as an essentially thin and flat plate.

[0044] The sectional view shows fixing lips projecting from the floor in the width direction. 28 recognize those that were installed before the heater housing was inserted 4 into the recording bag 116 further spaced out in the transverse direction and when inserted into the receiving pocket 16 parallel to the inner surfaces 118 These fixation lips were reshaped. 28 can act like barbs.

[0045] By applying a force over a surface area. 26 is the heater housing 4 in the recording bag 116 Plastically deformed. During this plastic deformation, the heating fin can also change shape. 114permanently deform. In any case, a cold weld results from the plastic deformation. This can be achieved by applying pressure against the contact surface. 26 The aluminum material of the heater housing is pressed with a force between 1400 and 3000 Newtons. This causes the aluminum to flow. 4 and bonds to the inner surfaces in a material-bonded manner 118 the recording bag 116 .

[0046] Typically, the components of the PTC heating device, which are located inside the heater housing, 4 are included, namely what was previously included in the recording of the position frame. 16 PTC element used 12 , the adjacent contact plates 10 and the insulating layer 22 as a unit between the thighs 6 of the heater housing 4 inserted before being placed in the recording bag 116 is introduced and pressed into this.

[0047] The Fig. 3 to Fig. Figure 7 shows variants of the heater housing. 4 Otherwise, components identical to those described previously are marked with the same reference symbols. In the illustrations according to the Fig. 3 to Fig. 7 is the heater housing in each case. 4 with the components included, not yet fully into the recording bag 116 inserted. Rather, it partially protrudes beyond the partition wall. 108 .

[0048] In the previously discussed embodiment, the heater housing forms 4 leg 6 with flat outer surfaces. These outer surfaces do diverge, but they are flat, i.e., level.

[0049] At the in Fig. The three variants shown are the thighs. 6 They are slightly convex in shape. They have a radius of between 500 and 1000 mm. (On the fixing lips) 28 This embodiment omits a positioning frame. 16is simply an electrically non-conductive plastic bridge 30 between one end of the heating fin 114 and the PTC element 12 planned. The plant areas 26 are on both sides of the PTC element 12 on both thighs 6 This results in the heater housing flowing when pressure is applied to both sides of the PTC element. 4 forming material and thus a more uniform connection between the heater housing and the inner surfaces 118 Furthermore, the PTC element can 12 center to the recording pocket 116 be arranged so that on both main side faces of the PTC element 12 The same heat transfer conditions prevail. The main side surface is the surface that runs lengthwise and widthwise along the PTC element. 12 extends.

[0050] In the variant according to Fig. 4 are a multitude of fixation lips 28 opposite the main side faces of the PTC element 12 formed. These are limited to the upper area of ​​the PTC element. 12 Otherwise, the following applies: Fig. 4. Third variant of the second variant shown according to Fig. 3.

[0051] In the fourth variant after Fig. 5 are fixation lips 28 solely in the area of ​​the heater housing base 8 trained. These fixation lips 28 deform, among other things, in the base of the recording bag 116 There are also two installation areas here. 26 shaped. The outer surfaces of the thighs 6 are convex.

[0052] The in Fig. Variant 6, shown, combines the variant according to the Fig. 4 and Fig. 5.

[0053] The Fig. Figure 7 shows a view of the entire width of the recording pocket. 116and the PTC heating element 12 A certain gap remains between the front of the PTC heating element and the front edge of the receiving pocket. 116 After installing the PTC heating element 2 into the recording bag 116 can the remaining free space within the recording pocket 116 filled with a highly thermally conductive, usually electrically insulating material. Reference symbol list 2 PTC heating elements 4 heater housings 6 thighs 8 Heater housing base 10 contact plates / conductor tracks 12 PTC elements 14 Connection flag 16 position frames 18 Upper frame rail 20 Lower frame rail 22 Insulation layer 26 Plant area 28 Fixing lip 30 plastic bridge 100 cases 102 Case base 104 Case base 106 Case covers 108 Partition wall 110 Circulation chamber / Boiler chamber 112 Connection chamber 114 heating fins 116 Recording bag 118 interior surface area 120 connection spigots QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 1872986 A1

[0003] EP 2637474 A1

[0004] EP 2337425 A1 [0004, 0005] CN 109028554 A

[0008]

Claims

[1] Electric heating device comprising: a housing (100) with a partition wall (108) which divides a connection chamber (112) from a heating chamber (110) for dissipating heat and from which at least one receiving pocket (116) projects into the heating chamber (110) as a heating rib (114), in which a PTC heating device (2) with at least one PTC element (12) and for supplying current to the PTC element (12) with different polarity, conductor tracks (10) which are electrically connected to the PTC element and are electrically connected in the connection chamber (112) are accommodated, wherein the PTC element (12) and at least one of the conductor tracks (10) is accommodated in a heater housing (4), characterized by , that the heater housing (4) is pressed into the receiving pocket (116) with plastic deformation of the heater housing (4) and / or the receiving pocket (116). [2] Electric heating device according to claim 1, characterized bythat the heater housing (4) is integrally connected to the receiving pocket (116) and is preferably cold-welded. [3] Electric heating device according to claim 1 or 2, characterized by that at least one surface of the heater housing (4) lying against the receiving pocket (116) is convex. [4] Electric heating device according to one of the preceding claims, characterized by at least one fixing lip (28) formed by an undercut on the heater housing (4), which is plastically deformed at least in sections by pressing the heater housing (4) into the receiving pocket (116), which is delimited in the thickness direction by opposing inner surfaces (118), and is applied to an inner surface (118) of the receiving pocket (116). [5] Electric heating device according to claim 4, characterized bythat the heater housing (2) has two legs (6) and a heater housing base (8) connecting the legs (6) to one another, whereby a substantially U- or V-shaped receiving space for the PTC element (12) and the at least one conductor track (10) is formed, and that at least one fixing lip (28) is provided on at least one of the legs (6) and / or two fixing lips (28) formed on opposite sides of the heater housing base (8). [6] Electric heating device according to one of the preceding claims, characterized by that the heater housing (4) has, at a rear end in the pressing direction, a contact surface (26) adapted for the attachment of a pressing tool. [7] Electric heating device according to one of the preceding claims, characterized by that the heater housing (4) has at least one inwardly directed locking projection. [8] Electric heating device according to one of the preceding claims, characterized by that the heater housing is manufactured using the pultrusion or extrusion process. [9] Method for producing an electric heating device comprising a housing with a partition wall which separates a connection chamber from a heating chamber for dissipating heat and from which at least one receiving pocket projects into the heating chamber as a heating rib, in which a PTC heating device with at least one PTC element and conductor tracks which are electrically connected to the PTC element in an electrically conductive manner for supplying current to the PTC element with different polarity and which are electrically connected in the connection chamber is received, wherein in the method the PTC element (12) and at least one of the conductor tracks (10) are introduced into a heater housing (4) of the PTC heating device (2) and into the receiving pocket (116) and the heater housing (4) is pressed into the receiving pocket (116) with plastic deformation of the heater housing (4) and / or the receiving pocket (116) and is preferably cold-welded to the receiving pocket (116). [10] Method according to claim 9, characterized bythat the heater housing (4) is inserted into the receiving pocket (116) in such a way that a heater housing base (8) is plastically deformed in the base of the receiving pocket (116). [11] Method according to claim 9 or 10, characterized by that the PTC element (12) and the at least one conductor track (10) are first introduced into the heater housing (4) and the heater housing (4) thus equipped is introduced into the receiving pocket (116). [12] Method according to claim 11, characterized by that the heater housing (4) is gripped for insertion by an insertion tool, by means of which the heater housing (4) is placed against the PTC element (12) under elastic or plastic deformation before the heater housing (4) is inserted into the receiving pocket (116).

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