Electric heating device and method for its production

Abstract

The present invention relates to an electric heating device (2) with a housing (100) which forms a receiving pocket (102) in which at least one PTC heating device (2) with at least one PTC element (4) received in a positioning frame (10) and conductor tracks (6) electrically connected to the PTC element (4) with different polarity is received.The present invention aims to provide an electric heating device of the type mentioned above, which can compensate for manufacturing tolerances in an improved manner without significantly impairing the heat transfer from the PTC element and can be manufactured economically, and proposes to thermally connect at least one profile part (26) to the PTC element (4) on opposite main side surfaces, wherein the outer main side surfaces of the profile parts (26) opposite the PTC element (4) are thermally connected to an inner surface (136) of the receiving pocket (102) and wherein the profile parts (26) are connected to the positioning frame (10).

Description

[0001] The present invention relates to an electric heating device with a housing that forms a receiving pocket in which at least one PTC heating element is received. The PTC heating element has a positioning frame in which at least one PTC element is received. Furthermore, conductive traces electrically connected to the PTC element and a heater housing are provided.

[0002] In the aforementioned prior art, the positioning frame serves to hold the PTC element and to arrange the conductor tracks. EP 2 637 474 A1 and EP 2 337 425 A1 each disclose PTC elements that are inserted into a corresponding receiving pocket. The electrical heating devices provided for this purpose have a housing with a partition that separates a connection chamber from a heating chamber for heat dissipation and from which at least one heating fin projects towards the heating chamber, which forms the receiving pocket in which the PTC heating device is accommodated.

[0003] Such a design can also be used in the present invention. EP 2 637 474 A1, which illustrates the preamble, discloses a PTC heating device that incorporates a wedge element as a structural unit, which is provided on a main side surface of the at least one PTC element. After the PTC heating device is inserted into the receiving pocket, the wedge element is moved to ensure good thermal conductivity between the PTC element and the inner surfaces of the receiving pocket.

[0004] 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 with a wedge-shaped pressure element, with at least one insulating layer between the conductor tracks and the opposing inner surfaces of the receiving pocket. This wedge element ensures that the layers of the layer structure are clamped against each other. These layers consist of at least the PTC element(s), the conductor tracks extending perpendicular to the direction of force exerted by the wedge element (usually contact plates), and at least one insulating layer.

[0005] Despite the downward-tapering cross-sectional shape of the receiving pocket, necessitated by the manufacturing process, 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 wedge element acting as an intermediary. The resulting pressure also presses the opposing heat dissipation surface of the PTC element directly against the opposing inner surface of the receiving pocket, either directly or via an insulating layer.

[0006] This ensures good heat dissipation. However, the problem is that, due to manufacturing tolerances, the mounting pocket does not always correspond to the intended shape.

[0007] Furthermore, PTC elements are subject to certain dimensional variations due to the manufacturing process. It is also not always guaranteed that the heat dissipation surfaces of the PTC element are perfectly straight and flat.

[0008] Pressing in a wedge as a pressure element can lead to stress peaks that can cause the 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.

[0009] EP 4 064 788 B2, EP 3 228 950 B1, US 2021 / 033303 A1, and EP 3 290 819 A1 each relate to an electric heating device comprising a PTC element, a profile section thermally connected to the PTC element, and a receiving pocket for it. EP 3 731 595 A1 and DE 201 21 116 U1 each relate to an electric heating device comprising a PTC element. The present invention aims to provide an electric heating device of the type mentioned above, which can compensate for manufacturing tolerances in an improved manner without significantly impairing the heat transfer from the PTC element and which can be manufactured economically.

[0010] To solve this problem, the present invention proposes an electric heating device with the features of claim 1.

[0011] The electric heating device is preferably an electric heating device for a motor vehicle. The housing is typically designed for heating a liquid medium and has inlet and outlet ports for this purpose, but otherwise seals the heating chamber. A partition preferably separates a connection chamber from a heating chamber in a fluid-tight manner. The partition is penetrated by an upper end of the PTC heating element. Typically, several PTC heating elements are provided, which project into the heating chamber as heating fins.The end of the PTC heating element projecting into the connection chamber typically includes contact tongues that are electrically contacted within the connection chamber. Preferably, a contacting device is provided that groups the different PTC heating elements into heating circuits by grouping the contact tongues. This contacting device is equipped with contact tongues that project into a populated printed circuit board in the same orientation as the contact tongues of the PTC heating elements. This populated printed circuit board controls the power current for heating the PTC heating element and typically forms a control unit; see EP 2 440 004 A1 or EP 1 872 986 A1.

[0012] The housing can also be formed by an extruded profile that creates a receiving pocket open on both sides. The inner surface of the receiving pocket is formed by a partition that creates a heating chamber extending parallel to the receiving pocket, which guides the fluid to be heated. Several profiles can be arranged side by side in this way, so that a parallel flow of the fluid to be heated passes by different receiving pockets, as is known, for example, from EP 0 899 985 A1. The receiving pocket can be formed between two joined profiles. Alternatively, the receiving pocket can be formed within a single extruded profile.

[0013] According to the present invention, a profile section is provided in the receiving pocket and between the PTC heating element and on the inner side of the receiving pocket. This profile section serves to compensate for stress peaks during the thermally conductive clamping of the PTC element in the receiving pocket, for which embodiments of the profile sections, which will be explained in more detail below, are preferred.

[0014] According to the present invention, the profile parts are connected to the positioning frame. The positioning frame incorporates at least the PTC element, which is received in a receptacle formed by the positioning frame in a manner known per se. The positioning frame also positions conductive traces, typically in the form of contact plates, which project beyond the positioning frame on one side to form contact tongues. The conductive traces can be materially or form-fit connected to the positioning frame. The profile parts are generally directly mechanically coupled to the positioning frame and / or permanently and / or immovably connected to it.

[0015] Insulating layers, preferably in the form of ceramic plates, are typically provided on the outer surface of the conductor tracks, such that a heating cell comprising the PTC element and the two contact surfaces is electrically insulated between the two insulating layers. Profile sections are typically located on the outer surface of the insulating layers. According to the invention, these are connected to the positioning frame. The connection of the profile sections to the positioning frame also typically results in the positioning of the insulating layers. One of the insulating layers can, for example, be held in a force-fit position, such as by clamping, between the profile section and the associated conductor track. Alternatively, fastening segments of the positioning frame, which interact with the profile sections, can also hold the conductor tracks and / or the insulating layers in position.By connecting the profile parts with the positioning frames, a PTC heating device is created that can be handled as a structural unit and, after pre-assembly, can be inserted into the receiving pocket as such.

[0016] The profile sections can be clipped to the positioning frame. For this purpose, the positioning frame typically has a locking latch that engages behind the respective profile section. More preferably, the positioning frame has an upper cross member projecting beyond the contact tongues on one side and a lower cross member opposite it. According to this preferred embodiment, positive locking segments project from each cross member, overlapping the associated profile sections. At least the positive locking segments associated with each cross member are typically designed as locking latches, so that the profile sections can be easily connected to the positioning frame by clipping them together.

[0017] It is understood that the positioning frame is typically made of an electrically non-conductive material, for example, plastic, preferably injection-molded. The profile components are typically extruded profiles made of metal, preferably aluminum. Each profile component is preferably connected in the receiving pocket via a tongue-and-groove joint. The tongue-and-groove joint extends in the insertion direction of the receiving pocket.

[0018] This means that, in a cross-sectional view perpendicular to the insertion direction, at least one groove projects from the inside of the receiving pocket, or a tongue is provided on this inside, into which a tongue projecting from the profile section engages. In the former case, the profile section has a groove into which the tongue associated with the heating fin engages. The groove or tongue extends in the insertion direction. When the profile section is inserted, usually together with the PTC heating element, the groove is forced into the corresponding tongue. The groove and tongue slide past each other in the insertion direction and along their longitudinal axis. The groove and / or the tongue may have elastic properties. This allows for a certain degree of tolerance compensation. Heat is extracted from the PTC element to the outer surface of the heating fin, which is exposed in the heating chamber, via the tongue-and-groove connection.

[0019] It is therefore preferable to provide a multitude of tongue-and-groove connections between at least one of the main side faces of the PTC element and the opposite inner surface of the receiving pocket. In a cross-sectional view perpendicular to the insertion direction, the main side face of the PTC element is considered to be its greatest extent. The PTC element is typically cuboid in shape. The main side face spans the width of the PTC element. In the aforementioned cross-sectional view, the thickness of the PTC element runs perpendicular to the width. Perpendicular to the plane spanned by the width and thickness, and essentially in the insertion direction, runs the longitudinal direction of the PTC element or the PTC heating element. This longitudinal direction corresponds to the insertion direction of the PTC heating element into the receiving pocket.

[0020] As mentioned previously, the tongue-and-groove joint is able to compensate for certain manufacturing tolerances through deformation in the area of ​​the tongue-and-groove joint. The typically numerous tongue-and-groove joints between the main side faces of the PTC element and the opposing inner surface of the mounting pocket maintain good heat dissipation from the PTC element.

[0021] Thus, the solution according to the invention allows for compensation of manufacturing tolerances without impairing the heat extraction from the PTC element.

[0022] According to a preferred embodiment of the present invention, a groove-limiting projection and / or a spring projection that at least partially forms the spring is pivotable about an axis extending substantially in the insertion direction. This pivotability is effected by at least one freestanding groove-limiting projection or one freestanding spring projection. The corresponding projection can be connected to the receiving pocket or the profile section via a relatively thin web. The pivot axis and the pivotability of the projection can be precisely adjusted by the orientation and shape of the web. The pivotability is generally at least elastic, and possibly also plastic.

[0023] According to a preferred embodiment of the present invention, the profile section has a U-shaped recess for the PTC heating element. This recess typically accommodates the PTC element, the conductor tracks, and any insulating layers provided, which in particular directly or indirectly cover the main side faces of the PTC element.

[0024] The profile section can be an extruded profile section. It is preferably made of aluminum. This necessitates at least one insulating layer between the PTC element and an inner surface of the profile section against which the PTC heating element makes thermally conductive contact.

[0025] With a view to achieving the most symmetrical heat dissipation possible and uniform tolerance compensation, a preferred aspect of the present invention proposes providing tongue-and-groove connections between each main face of the PTC element and the opposite inner face of the receiving pocket. Accordingly, the corresponding tongue-and-groove connections are preferably formed adjacent to the two main side faces of the PTC element.

[0026] With a view to good heat transfer between the profile section and the inside of the receiving pocket, a preferred embodiment of the present invention proposes that at least one groove-limiting projection and / or at least one spring projection forming at least part of the spring be wedge-shaped towards its free end. The spring projection and the interacting surface of the groove-limiting projection are shaped such that a flat contact surface is formed between them. The wedge shape promotes the elastic pivoting movement of one of the projections during assembly. The present invention also assumes that the receiving pocket preferably tapers wedge-shaped towards its lower, closed end.Similarly, the tongue and groove joint can also be wedge-shaped in the insertion direction, so that in each cross-sectional plane perpendicular to the insertion direction of the PTC heating device into the receiving pocket there is approximately the same overlap in the area of ​​the tongue and groove joint.

[0027] Preferably, at least one groove-limiting projection and / or at least one spring projection that at least partially forms the spring is formed integrally on the receiving pocket. This requirement preferably also applies to the profile section, which is preferably formed as an extruded profile and may have a film hinge on its underside, so that opposing legs of the profile section are connected to each other opposite the connecting chamber. This reduces the number of parts to be handled.

[0028] According to a preferred embodiment of the present invention, at least one compression element is provided between the profile section and a main side surface of the PTC element. In the case of a U-shaped profile section, the compression element is located within the profile section. Preferably, one compression element is provided between each of the two main side surfaces of the PTC element and the inner surfaces of the profile section. The compression element can be formed by a spring made of metal. The spring typically extends across the entire surface of the main side surface in a cross-sectional view transverse to the insertion direction. It is preferably located between an inner surface of the profile section and an insulating layer that covers the PTC heating element on the outside.

[0029] According to a preferred embodiment, a curing adhesive is introduced into the mounting pocket. This adhesive is at least partially contained within the tongue-and-groove joint and cures there. In this way, the PTC heating element and the profile section are secured within the mounting pocket by the adhesive. The adhesive can be a plastic adhesive with good thermal conductivity. For example, it can be a silicone adhesive to which highly thermally conductive particles, such as aluminum oxide particles, have been added. This also improves heat dissipation from the PTC element. It is understood that the entire mounting pocket can be filled with adhesive. The adhesive is preferably an electrically insulating adhesive.

[0030] With its secondary aspect, the present invention proposes a method for manufacturing a PTC heating device of the type mentioned above. In this method, the insulating layers, which are applied to the outside against the conductor tracks, are temporarily held in place by the positioning frame. The positioning frame accordingly serves as an assembly aid for pre-positioning the insulating layers. These insulating layers are typically rigid and usually include at least one ceramic layer, which may have further layers on one or both sides, for example, in the form of a plastic film. Profile sections are applied to the outside of the insulating layers so that at least one of the insulating layers is located between each profile section and the conductor track, which is typically covered by the insulating layer. In the manner described above, the profile section is joined to the positioning frame in the method according to the invention.Thus, the profile part is held in place on the positioning frame at the end of its assembly. The profile part also holds the insulating layer. The inventive method therefore creates a structural unit that is manageable on its own during the assembly of the electric heating device and comprises the positioning frame, at least one PTC element, the electrically connected conductor tracks, the insulating layers, and the profile parts. At least one insulating layer and one profile part are located on both sides of the PTC element.

[0031] The positioning frame can also be positively connected to the conductor tracks, especially if these are designed in the form of contact plates.

[0032] Further details of the present invention will become apparent from the following description of an exemplary embodiment in conjunction with the drawing. The drawing shows: Fig. 1a perspective exploded view of an embodiment of a PTC heating device; Fig. 2 a perspective exploded view of the PTC heating device according to Fig. 1 with a partial view of the housing of an electric heating device; Fig. 3 a cross-sectional view of part of the electric heating device; Fig. 4 a sectional view along line III-III as shown in Fig. 3 ; and Fig. 5 a sectional view according to Figure 4 for one variant.

[0033] The Figure 1Figure 1 shows a PTC heating device 2 with a PTC element 4, on the main side surfaces of which conductive traces 6 in the form of sheet metal strips are attached. These conductive traces are covered on the outer surface opposite the PTC element 4 by insulating layers 8, which in this case consist of ceramic plates. Reference numeral 10 identifies an injection-molded positioning frame made of plastic, which forms a receptacle 18 for the PTC element 4 between two cross members, the upper cross member being designated by reference numeral 12 and the lower cross member by reference numeral 14, and two longitudinal members 16 extending perpendicular to the cross members 12, 14. The contact plates forming the conductor tracks 6 have contact tongues 20 formed in one piece by stamping, which are provided in the longitudinal direction of the upper cross member 12 at opposite ends of the position frame 10 and are received in feedthrough openings of the upper cross member 12.

[0034] From the crossbeams 12, opposite positive-locking segments 22 with locking pawls 24 project from their outer ends. These special positive-locking segments 22 extend beyond the upper crossbeam 12 in the width direction.

[0035] The positive locking segments 22 and the locking pawls 24 are located at the outer edge of the positioning frame 10, extending from the longitudinal beams 16 and thus outside the main side surface of the PTC element 4. The main side surface of the PTC element 4 is formed by the largest surface of the cuboid PTC element 4. In this case, the other surfaces extend between the two main side surfaces as a circumferential border.

[0036] The locking pawls 24 engage profile sections marked with reference numeral 26, which are formed from extruded aluminum elements. The profile sections 26 are captively connected to the positioning frame 10 by the positive locking segments 22 and 24. As is typical, the locking pawls 24 have a front ramp surface which widens when the profile sections 26 are pressed onto them. After the profile sections 26 are in position, the locking pawls 24 spring back against the outer surface of the insulating layers 8 to engage the profile sections 26. This connects the profile sections 26 to the positioning frame 10. The insulating layers 8 are dimensioned to also fit between the positive locking segments 22, and may also be locked in place as described above, but in any case, they are clamped between the positively locked profile sections 26.

[0037] During assembly, a contact plate forming the conductor track 6 is typically connected to the position frame 12 on one side, in this case by inserting the contact plate with its contact tongue into the feedthrough opening of the upper cross member 12. The positive locking segments 22 then engage the conductor track 6. The receptacle 18 is then closed on one side. The PTC element 4 is then inserted into this receptacle.

[0038] Subsequently, for example, on the side provided with the conductor track 6, the associated insulating layer 8 is placed against the corresponding conductor track 6. The insulating layer is positioned between the locking pawls 24 or the positive locking segments 22, which ensure pre-positioning and retention of the insulating layer 8, which, according to the exemplary embodiment, is formed by a ceramic plate. Then, from the same side, the profile part 26 is placed against the positioning frame 10 and connected to the positioning frame 10 via the positive locking segments 22 and 24.

[0039] On the opposite side, the other conductor track 6, the insulating layer 8 associated with this conductor track 6, and finally the profile part 26 provided there can then be mounted in the manner described above. Here too, before the profile part 26 is finally locked to the positioning frame, the positioning frame 12 holds the insulating layer 8 or the conductor track 6 in a position favorable for assembly.

[0040] The PTC heating device 2 prepared in this way is in Fig. 2 This can be seen in the assembled state. In this embodiment, only the positive locking segments 22 assigned to the upper cross member 12 are visible as latching pawls. The positive locking segments 22 provided on the lower cross member 14 merely overlap the profile parts 26.

[0041] In Fig. 2To the right of the PTC heating element 2, a housing 100 of an electric heating device, designated by reference numeral 98 in the following figures, can be seen. The housing 100 forms receiving pockets 102. A single PTC heating element 2 fits into each of the receiving pockets 102. The receiving pockets 102 are each shaped like a hammerhead at their ends, thus providing space for the insertion of the positive-locking segments 22, 24. Between these segments, a structure of the receiving pocket 102, which will be explained in more detail below, interacts with a structure provided on the outer surface of the profile parts 26 to, on the one hand, arrange the PTC heating element in the receiving pocket 102 with a certain preload and thus ensure good thermal conductivity, and on the other hand, to prevent excessive stress on the elements of the PTC heating element 2 provided between the profile parts 26.The insulating layers 8 and the PTC element 4 are ceramic components and are therefore only partially able to compensate for point loads or bending loads through elastic deformation.

[0042] The Figure 3 Figure 1 shows the essential components of the electric heating device 98 with a housing 100 made of a highly thermally conductive material, in this case die-cast aluminum. The housing 100 forms a wall 105 that completely surrounds a heating chamber 104. Fig. 2 The heating chamber 104 is still open at the bottom, since a base closing the housing 100 at the bottom is in Fig. 3not shown. The same applies to a control housing cover, which is connected to the housing 100 on the opposite side to cover and surround a connection chamber designated by reference numeral 106. Between the heating chamber 104 and the connection chamber 106, the housing 100 forms a partition 108 in one piece. Heating fins 110 project from this partition 108 into the heating chamber 102. The heating fins 110 are closed at their lower end, which projects into the heating chamber 102. As the hatching in Fig. 3 To illustrate, the heating fins 110 together with the partition 108 and the wall 105 are formed from a one-piece die-cast aluminum housing 100.

[0043] The heating fins 110 form a wedge-shaped, downwardly tapered receiving pocket 102. The PTC heating element, designated by reference numeral 2, is received in this receiving pocket 102. As shown in the sectional view according to... Fig. 4To clarify, the PTC heating device 114 comprises a PTC element 116, on the main side surfaces of which conductive traces 118 are located. These traces consist of a wire mesh made of an electrically conductive material. On the side of the conductive trace 118 opposite the PTC element 116, there is an insulating layer 120, which can be formed by a ceramic layer and / or an insulating plastic film. The gap between the insulating layer 120 and the PTC element 116 is completely filled by the conductive trace 118. The spaces between the wire mesh are filled with a highly thermally conductive adhesive, which is also located in the plane of the conductive trace 118 and is considered part of the conductive trace 118. The wire mesh extends beyond the PTC element to form contact tongues 122, which are located in Fig. 3are shown. Otherwise, for the sake of clarity, the individual layers of the layered structure between the PTC element 116 and the profile section 126 are shown in Figure 3 summarized in the form of a sectioned layer between the respective profile part 126 and the PTC element 116.

[0044] The contact tongues 122 are exposed in the connection chamber 106. The PTC element 116 and the insulating layer 120 are joined to form a unit by the adhesive bond of the conductor track 118. On the outside of this PTC heating device 114 are located in Fig. 4 Recognizable compression elements 124 in the form of corrugated spring sheets.

[0045] The Figure 4 Details of the respective profile parts 126 can be seen, which are identical in this case. The compression elements 124 abut against the inner sides of these profile parts 126.

[0046] From the outer sides of the profile parts 126, groove-limiting projections 132 extend, each enclosing a groove 134 in pairs. As in particular Fig. 4 As illustrated, a multitude of identically shaped grooves 134 are recessed in this form on the outer surface of the main side surfaces of the profile parts 126. The grooves 134 extend in the insertion direction of the receiving pocket 102, which is located in Fig. 3 is marked with an E.

[0047] An inner surface 136 of the receiving pocket 102 has projecting spring projections 138. These spring projections 138 are integrally formed on the die-cast housing 100. As shown in the cross-sectional view according to Fig. 4The spring projections 138 taper wedge-shaped towards their free ends. Similarly, the groove-limiting projections 132 also taper wedge-shaped towards their free front ends. It is understood that only the surfaces of the groove-limiting projections 132 that define the groove 134 have this shape. To illustrate this, the following are shown in Fig. 4 The spring protrusions 138 were omitted on the right side.

[0048] At the in Fig. 4In the illustrated embodiment, the assembly process begins with the positioning frame 128 being fitted with the PTC element 116, the conductor tracks 118, the insulating layers 120, the compression elements 124, and the profile parts 126. The pre-assembled PTC heating element 114 is then inserted into the receiving pocket 102. The spring projections 138 engage in their corresponding grooves 134. A comparison of the right and left sides reveals... Fig. 4 Deformation is visible in the area of ​​the groove limit projections 132. This provides a certain degree of tolerance compensation. Additionally, the compression element 124 is deformed to compensate for tolerances. Ideally, after assembly, the compression element 124 rests essentially over its entire surface against both the inner surface of the profile part 26 and the outer surface of the insulating layer 120.

[0049] The compression element 124 can be made of aluminium, copper, copper beryllium or another material with good thermal conductivity capable of applying permanently elastic preload forces.

[0050] Remaining cavities in the receiving pocket 102 can be filled with a highly thermally conductive material, for example a curing plastic compound filled with thermally conductive particles.

[0051] At the in Fig. 5In the illustrated variant, the groove limiting projections 132 are connected to the remaining profile section 26 via a relatively thin web 140. This web 140 creates a pivot axis that extends essentially in the insertion direction E. In this embodiment, compression elements can be omitted. Adjacent groove limiting projections 132 for different grooves 134 are sufficiently spaced apart so that they can pivot about their pivot axis when the wedge-shaped spring projections 138 are inserted, without colliding with each other. This allows for considerable tolerance compensation. The positions of the PTC heating element 2 within the profile sections 126 are thereby pressed against the inner surface of the two profile sections 126 with good elastic tension, thus improving heat dissipation.

[0052] Figure 5The figure also illustrates the warping of the inner surface of the profile sections 126, such that in a cross-sectional view, this surface essentially contacts the insulating layer 120 at specific points and along a longitudinal line. This deformation of the respective profile section 126 also causes additional elastic tension on the layers of the PTC heating element 114 in the receiving pocket 102. Reference symbol list

[0053] 2PTC heating element 4PTC element 6 Conductor track 8 Insulation layer 10 Positioning frame 12 Upper cross member 14 Lower cross member 16 Longitudinal member 18 Mounting 20 Contact tongue 22 Positive locking segment 24 Latching pawl 26 Profile part 98 Electric heating device 100 Housing 102 Mounting pocket 104 Heating chamber 105 Wall 106 Connection chamber 108 Partition 110 Heating fin 114PTC heating element 116PTC element 118 Conductor track 120 Insulation layer 122 Contact tongue 124 Compression element 126 Profile part 128 Positioning frame 128 Film hinge 132 Groove limiting projection 134 Groove 136 Inner surface 138 Spring projection 140 Web Direction of entry

Claims

1. Electric heating device (2) with a housing (100) which forms a receiving pocket (102) in which at least one PTC heating assembly (2) with at least one PTC element (4) received in a position frame (10) and strip conductors (6) electrically conductively connected to the PTC element (4) for energizing the PTC element (4) with different polarity is received, wherein at least one profile part (26) is connected in a heat-conducting manner to the PTC element (4) on opposite main side surfaces of the PTC element (4) in each case, wherein outer main side surfaces of the profile parts (26) opposite the PTC element (4) are connected in a heat-conducting manner to an inner surface (136) of the receiving pocket (102) in each case, characterized in that an electrically insulating layer (8) is provided between each of the profile parts (26) and the strip conductors (6), which profile parts (26) are connected to the position frame (10).

2. Electric heating device according to claim 1, characterized in that the profile parts (26) are clipped to the positioning frame (10).

3. Electric heating device according to claim 1 or 2, characterized in that the position frame (20) has an upper cross beam (12) surmounted on one side by the contact tongues (20) and a lower cross beam (14) provided opposite thereto, and in that form-fit segments (22) each extend from the cross beams (12, 14) and engage over the associated profile parts (26).

4. Electric heating device according to claim 3, characterized in that at least one of the cross beams (12) has a form-fit segment (22) formed in the manner of an engaging pawl (24).

5. Electric heating device according to any of the preceding claims, characterized in that the profile parts (26) are each formed by extruded profiles made of metal, in particular of aluminum.

6. Electric heating device according to any of the preceding claims, characterized in that the profile parts (26) are connected to the receiving pocket (102) via a tongue and groove joint extending in the insertion direction of the receiving pocket (102).

7. Electric heating device according to claim 6, characterized in that the a tongue and groove joint has at least one groove limiting projection (132) limiting the groove (134) and at least one tongue projection at least partially forming the tongue (138), which tongue (138) is received within the groove (134) for forming the tongue and groove joint, wherein at least one of the groove limiting projection (132) and the tongue projection can be pivoted about an axis extending in the insertion direction (E).

8. Electric heating device according to any of the preceding claims, characterized in that the housing (100) comprises a partition wall (108) which separates a connection chamber (126) from a heating chamber (102) for dispensing heat and from which at least one heating rib protrudes towards the heating chamber (102), forming the receiving pocket (102).

9. Method for producing a PTC heating assembly (2) for an electric heating device (2) with a housing (100) which forms a receiving pocket (102) in which the PTC heating assembly (2) is received with at least one PTC element (4) received in a position frame (10) and strip conductors (6) which are electrically conductively connected to the PTC element (4) for energizing the PTC element (4) with different polarity and which are each covered on the outside with at least one insulating layer (8), characterized by the insulating layers (8) applied on the outside against the strip conductors (6) being held via the positioning frame (10) and, after profile parts (26) have been applied against the insulating layers (8), being held on an outside of the respective insulating layer (8) facing away from the PTC element (4) by a connection of the profile part (26) to the positioning frame (10) between the insulating layer (8) and the profile part (26), and in that a structural unit comprising the at least one PTC element (4) is formed by the positioning frame (10), the strip conductors (6), the insulating layers (8) and the profile parts (26).

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