EP3863373A1 - Electric heating device and method for its production - Google Patents

Abstract

The present invention relates to an electrical heating device comprising: a housing (100) with a partition (108) which divides a connection chamber (112) from a heating chamber (110) for dissipating heat and from which at least one as a heating rib (114) into the Holding pocket (116) protruding into the heating chamber (110), in which a PTC heating device (2) with at least one PTC element (12) and for energizing the PTC element (12) with different polarity with this electrically conductively connected conductor tracks (10 ), which are electrically connected in the connection chamber (112), are accommodated, the PTC element (12) and at least one of the conductor tracks (10) being accommodated in a heater housing (4) PTC heating device and / or the pressure element or the PTC heating device as a whole can be pushed out of the receiving pocket due to vibrations and, according to the present invention, to improve the heat extraction According to the invention, it is proposed to press the heater housing (4) with plastic deformation of the heater housing (4) and / or the receiving pocket (116) into the receiving pocket (116).

Description

The present invention relates to an electrical heating device having a housing with a partition wall which divides a connection chamber from a heating chamber for emitting heat. At least one receiving pocket protruding as a heating rib into the heating chamber protrudes from the partition. A PTC heating device is provided in this pocket. Furthermore, a pressure element is accommodated in the pocket, which keeps the heat extraction surfaces of the PTC element against opposite inner surfaces of the accommodation pocket.

The PTC heating device has at least one PTC element and conductors that are electrically conductive. The conductor tracks are connected to the PTC element in an electrically conductive manner. This connection can be a form-fitting and / or force-fitting and / or material connection.

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

The previous proposals made by the applicant EP 2 637 474 A1 or. EP 2 337 425 A1 each disclose PTC heating devices which are introduced into a previously mentioned receiving pocket.

The EP 2 337 425 A1 a solution in which a conductor track resting on 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 only serve to improve electrical contacting of the PTC element.

In the previously described known solutions, the receiving pocket tapers towards its lower closed end. Accordingly, the introduction opening, which opens to the connection chamber, is wider than the lower closed end of the receiving pocket. The PTC elements and the contact plates resting on them on both sides are usually clamped in the receiving pocket with a wedge-shaped pressure element with an interposition of at least one insulating layer between the conductor tracks and opposing inner surfaces of the receiving pocket. This wedge element ensures that the layers of the layer structure are clamped against one another in the receiving pocket. These layers are at least the PTC elements and are at right angles to the direction of force action of the wedge element extending conductor tracks, usually contact plates, and at least one insulating layer.

The wedge element should enable good heat transfer, preferably between the two opposing heat extraction surfaces of the PTC element and the inner surfaces of the receiving pocket assigned to them with the interposition of the pressure element, despite the production-related, downwardly tapering cross-sectional shape of the receiving pocket. As a result of the pressure built up there, the opposite heat extraction surface of the PTC element is also placed against the opposite inner surface of the receiving pocket either directly or with the interposition of an insulating layer.

CN 109028554 A discloses an electrical heating device with the preamble features of claim 1. In this prior art, the PTC heating device comprises a pocket-shaped heater housing which has opposite side sections which are connected to one another via a bottom section and which contains the PTC element and the conductor tracks records. The pocket-shaped heater housing accordingly forms a receptacle for at least the PTC heating element. The pocket-shaped heater housing is wedge-shaped in cross section in order to enable uniform heat-conducting contact of the heater housing designed as a pressure element on the inner surfaces of a receiving pocket which tapers towards its lower end facing away from the connection chamber.

The previously presented prior art solutions each ensure good heat extraction. However, there is the problem that the receiving pocket does not always correspond to the designed shape due to manufacturing tolerances. Because the PTC elements are subject to considerable dimensional fluctuations due to production. It is also not always ensured that the heat extraction surfaces of the PTC element are completely straight and flat.

Pressing in a wedge as a pressure element can lead to voltage peaks, which can break the ceramic PTC element or a ceramic insulating layer within the receiving pocket. Depending on the 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 basically sits ineffectively on the lower end of the receiving pocket. If, on the other hand, the free space remaining before the introduction of the wedge element is too small, this results in the height direction of the receiving pocket, ie between the lower end and the Inlet opening only insufficient coverage of the heat extraction surface of the PTC element. As a result, the PTC element heats up too much and prevents further consumption of power current. The efficiency of the PTC element is therefore poor.

There is also the possibility that layers of the PTC heating device and / or the pressure element or the PTC heating device as a whole are pushed out of the receiving pocket or migrate out of the receiving pocket due to vibrations.

The present invention seeks to at least partially remedy the aforementioned problems.

For this purpose, the present invention proposes an electrical heating device having the features of claim 1.

In the heating device according to the invention, the receiving pocket protrudes into the heating chamber as a heating rib in a manner known per se. The receiving pocket is usually formed in one piece on the partition. The receiving pocket is usually made of a material that conducts heat well, usually metal. The receiving pocket by itself or in conjunction with the partition can be produced by deep drawing or casting of a metal. The receiving pocket is preferably made of aluminum and is formed in one piece on the partition wall by forming, in particular by deep drawing.

The receiving pocket - like the receiving pocket known from the prior art - preferably has a wedge-shaped cross-sectional shape which extends towards the bottom of the receiving pocket, i.e. H. the end of the heating rib protruding into the heating chamber is tapered.

According to the invention, the heater housing is received in this receiving pocket. The heater housing usually takes up the PTC element completely and in any case predominantly takes up the conductor tracks. In particular, the main side surfaces of the PTC element are usually covered by the heater housing. The heat-dissipating main side surfaces of the PTC element are arranged opposite the side surfaces of the heating rib in the assembled state, so that heat can be extracted from the PTC element in a direction transverse to the main side surfaces, passed through the receiving pocket and dissipated via the side surfaces to the heating chamber . The heater housing is located in this heat conduction path.

The heater housing is usually made of a material that conducts heat well. The heater housing is in particular formed from a flowable material, for example Copper or aluminum, which has a relatively low strength with good thermal conductivity. The heater housing can also be formed from a plastic highly filled with heat-conducting particles. The volumetric degree of filling of the thermally conductive particles should not be less than 60 percent by volume.

The heater housing not only accommodates the PTC element and mainly the conductor tracks. Usually, there is also at least one insulating layer between the PTC element and an inner surface of the heater housing, which insulating layer can be formed from an electrically insulating material, in particular a plastic or a ceramic. The insulating layer usually covers the conductor track, which is directly electrically conductive on the PTC element, on the outside, so that this polarity does not make direct contact with the inner surface of the heater housing.

On the opposite side, the current can be introduced directly through the heater housing, which in this case forms the conductor track. Usually, however, two conductor tracks, which are assigned different polarity, are received as separate components in the heater housing and are each electrically isolated from the heater housing via an insulating layer. The insulating layers provided parallel to the opposite main side surfaces of the PTC element can be formed from a single film wrapped around the PTC element on the underside. The PTC element can be received in a positioning frame made of an electrically insulating material, which positions the PTC element (s) and spaced them apart, so that the positioning of the positioning frame in the heater housing results in a predetermined alignment and arrangement of the PTC element (s) is reached in the receiving pocket. This position frame can be covered on the outside with the insulating layers or surrounded by a single insulating layer.

According to the present invention, the heater housing is pressed into the receiving pocket with 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 which are inclined to one another at an angle of between 2 ° and 5 °.

As part of the assembly, the heater housing is usually first equipped with the elements received therein, ie the PTC element of the at least one conductor track and the insulating layer that may be provided. Then the heater housing is placed in the receiving pocket. Then the plastic deformation takes place. For this purpose, for example, the heating rib can be plastically deformed by using a deformation tool directly interacts with the heating rib. In addition or as an alternative, a deformation tool can also act against the heater housing in order to bring about the plastic deformation according to the invention from the inside of the receiving pocket. In any case, due to the deformation, an intimate, plastically deformed bond is achieved between the heater housing and the inner surface of the receiving pocket. Furthermore, due to the deformation of the heater housing and / or the receiving pocket, the PTC element is arranged firmly, in particular vibration-proof and with good heat conduction in the heat path between the PTC element and the side surface of the heating rib.

In the configurations described above, in addition to a vibration-proof fastening of the PTC element in the receiving pocket, good heat extraction and a usually complete or at least almost complete filling of the receiving pocket by the components inserted therein, at least in the area of the receiving pocket that is used for the heat extraction the PTC element is of particular importance. The lower area of the receiving pocket is usually connected to the heater housing over its entire surface. Also between the main side surfaces of the PTC element and the associated inner surfaces of the receiving pocket there is full-surface contact and thus good heat extraction from the PTC element to the side surfaces of the heating rib. In the case of the heat conduction discussed here, the heat conduction path from the main side surfaces into the side surfaces of the heating rib is particularly important. Due to their smaller dimensions, the end faces of the PTC element can usually only make a smaller contribution to the extraction of heat anyway. The main side surfaces are usually those surfaces which have the greatest extent in the length or width direction of the PTC element. The end face surfaces connect these main side faces. The PTC element is usually cuboid and has a much greater extent in the length or width direction than in the height or thickness direction. The thickness direction is usually at least 5 times smaller than one of the dimensions in the length and / or width direction. The main side surface is spanned by the two extensions in length and width.

According to a preferred development of the present invention, the heater housing is materially connected to the receiving pocket, particularly as a result of the plastic deformation, particularly preferably cold-welded. In this preferred development, the plastic deformation of the heater housing and / or receiving pocket has to take place in such a way that a material connection, in particular formed by welding, results between the heater housing and the receiving pocket.

An end face that extends essentially transversely in the direction in which the PTC element is introduced can be provided adjacent to the bottom of the receiving pocket. Usually, at least after the plastic deformation, there is also material of the heater housing 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 can usually contribute little to the extraction of heat. The end faces of the PTC element extending at right angles to these two end faces can be exposed in the receiving pocket without a direct heat conducting surface. This is preferable for reasons of good electrical insulation. The receiving pocket is usually filled with an electrically insulating compound after the heater housing has been inserted and deformed, which prevents air and leakage currents and which can be located between a frontal boundary of the heating rib and the corresponding end faces of the PTC element, so that over this electrically insulating mass a certain amount of heat extraction to the outer surface of the heating rib can take place. The mass with good thermal conductivity can be, for example, a hardening silicone mass to which electrically non-conductive, but highly heat-conductive particles have been added. These particles can be aluminum oxide spheres.

The following consideration relates in particular to a cross-sectional view through the PTC element, which intersects the upper and lower end faces and extends parallel to the edge-side end faces of the PTC element. In such a cross-sectional view, at least one surface of the heater housing resting against the receiving pocket is convex. This shape of the heater housing can relate to the state before the deformation. Usually, however, such a convex configuration also results in a deformed configuration in which the heater housing rests with a convex surface against the inner surface of the receiving pocket. As a result of a deformation of the heater housing, the inner pocket can have been deformed in a concave outward direction, corresponding to the convex configuration of the heater housing.

According to a preferred development of the present invention, at least one fixing lip is formed on the heater housing by an undercut. This fixing lip is at least partially plastically deformed by the heater housing being pressed into the receiving pocket and placed against the inside of the receiving pocket. This development can be derived from the consideration that a kind of barb or the like is formed by a slightly deforming fixing lip, which at least after the plastic deformation in an improved manner anchoring the heater housing in the Can effect receiving pocket. The fixing lip can be provided at any point in the height direction, ie the direction in which the heater housing is inserted into the receiving pocket. With a view to the best possible heat extraction between the main side surfaces and the heating rib, however, it is preferable to provide the corresponding fixing lip close to the bottom of the receiving pocket.

In view of this, the present invention proposes providing the heater housing with two legs and a heater housing base connected to them. The heater housing forms an essentially U-shaped 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 one another. Said fixing lip is provided on at least one, preferably on two legs, the at least one fixing lip being provided in the area of the heater housing base. By definition, the bottom is that area which lies in front of the PTC element in the direction in which the heater housing is inserted into the receiving pocket.

According to a preferred development of the present invention, the heater housing has, at a rear end in the press-in direction, a contact surface which is adapted to be used for attaching a pressing tool. This contact surface can be formed by an essentially flat surface extending transversely to the press-in direction. The contact surface can also be formed by a trough-shaped depression. The contact surface is designed to be adapted to the attachment of a pressing tool. This pressing tool usually acts from the connection chamber on the heater housing in order to press the heater housing in the receiving pocket, in particular to plastically deform it and thus cold-weld it in the receiving pocket. This usually takes place when the heater housing is inserted into the receiving pocket.

According to a development of the present invention, the heater housing can have at least one inwardly directed locking projection. This locking projection usually lies flat in the finished product in the direction of the PTC element, for example against the insulating layer. The locking projection can act in the manner of a barb, which prevents the PTC element from being inadvertently detached from the heater housing, which may be open at the top. After the plastic deformation of the heater housing, this locking projection may basically 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.

The previously mentioned heater housing can be produced as an elongated material by means of extrusion or extrusion and then cut to length so that its length essentially corresponds to the width of the PTC element.

The present invention also provides a method for producing an electrical heating device of the type mentioned above. In the method, the PTC element with the at least one conductor track, optionally with the aforementioned insulating layer, is introduced into a heater housing and into the receiving pocket. The heater housing can first be equipped with the elements contained therein and then placed in the receiving pocket. Alternatively, the heater housing can first be placed in the receiving pocket and then equipped.

In any case, according to the method according to the invention, during the introduction of the heater housing or after the introduction of the heater housing and the components accommodated therein, the heater housing is pressed with plastic deformation in the receiving pocket and preferably cold-welded to the receiving pocket.

In the case of the invention, when the heater housing is introduced into the receiving pocket, preferably after the heater housing has been equipped with the components, a heater housing base is plastically deformed in the bottom of the receiving pocket.

According to a preferred development of the present invention, in which the heater housing is initially equipped with the aforementioned components and then inserted into the receiving pocket, the heater housing is gripped by an insertion tool for insertion. In this case, opposing legs of the heater housing are usually gripped by the insertion tool and pivoted towards one another. The heater housing is placed against the PTC element by the insertion tool with elastic and / or plastic deformation before it is inserted into the receiving pocket. The installation can take place directly against the PTC element or with the interposition of an insulating layer or the contact plate. Usually, the previously mentioned, inwardly directed locking projection of the heater housing is plastically deformed with this methodical procedure, so that a flat opposing surface is formed for the PTC element on both main sides of the heater housing on which the PTC element is directly or indirectly below Intermediate layer of the contact plate and / or the insulating layer is applied.

Fig. 1

eine perspektivische Seitenansicht eines Ausführungsbeispiels einer elektrischen Heizvorrichtung mit teilweise weggenommenem Gehäuse;

Fig. 2

eine Querschnittsansicht der in Figur 1 mit Bezugszeichen 102 gekennzeichneten Gehäusebasis mit einer ersten Variante eines Heizergehäuses, das in einer Aufnahmetasche eingepresst ist

Fig. 3

eine perspektivische Schnittansicht der Aufnahmetasche mit einer zweiten Variante eines Heizergehäuses vor dem vollständigen Einbringen in die Aufnahmetasche;

Fig. 4

eine perspektivische Schnittansicht der Aufnahmetasche mit einer dritten Variante eines Heizergehäuses vor dem vollständigen Einbringen in die Aufnahmetasche;

Fig. 5

eine perspektivische Schnittansicht der Aufnahmetasche mit einer vierten Variante eines Heizergehäuses vor dem vollständigen Einbringen in die Aufnahmetasche;

Fig. 6

eine perspektivische Schnittansicht der Aufnahmetasche mit einer fünften Variante eines Heizergehäuses vor dem vollständigen Einbringen in die Aufnahmetasche und

Fig. 7

das Ausführungsbeispiel nach Figur 6 in einer Seitenansicht mit vollständiger Heizrippe.

Further details and advantages of the following invention emerge from the following description of an exemplary embodiment in conjunction with the drawing. In this drawing

Fig. 1

a perspective side view of an embodiment of an electrical heating device with partially removed housing;

Fig. 2

a cross-sectional view of the in Figure 1 Housing base, identified by reference numeral 102, with a first variant of a heater housing which is pressed into a receiving pocket

Fig. 3

a perspective sectional view of the receiving pocket with a second variant of a heater housing before complete introduction into the receiving pocket;

Fig. 4

a perspective sectional view of the receiving pocket with a third variant of a heater housing before complete introduction into the receiving pocket;

Fig. 5

a perspective sectional view of the receiving pocket with a fourth variant of a heater housing before complete introduction into the receiving pocket;

Fig. 6

a perspective sectional view of the receiving pocket with a fifth variant of a heater housing before complete introduction into the receiving pocket and

Fig. 7

the embodiment according to Figure 6 in a side view with complete heating rib.

the Figure 1 shows a housing 100 of an electrical heating device, which comprises a base element 102, a housing base 104 and a housing cover 106. In the exemplary embodiment shown, the housing base 104 forms a partition 108 which extends parallel to the housing base 102 and which separates a circulation or heating chamber 110 from a connection chamber 112. In the exemplary embodiment shown, at least the housing base 104 is made in one piece from aluminum. Heating ribs 114 protrude from the partition wall 108 in the direction of the heating chamber 110. These heating ribs are conically tapered towards their fine end at an angle of approximately 2.5 ° and form a receiving pocket 116 with inner surfaces 118 lying opposite one another. The interior of the heating rib 114 and the connection chamber 112 are fluidically separated from the heating chamber 110.

In the present case, connections lead to the heating chamber 110 on opposite end faces of the housing base 104. These connections are formed as hose or pipe connection stubs 120 and protrude from the outside of the actual wall of the housing base 104. They are used to connect hoses or lines that carry liquid fluid to be heated, which is to be heated in the heating chamber 110.

For this purpose, the receiving pockets 116 are each equipped with PTC heating devices 2. One or more of these PTC heating devices 2 can be inserted one behind the other in the longitudinal direction of the heating ribs 114 in the individual receiving pockets 116.

The essential structure of the PTC heating device 2 is basically identical for the variants discussed below. The PTC heating device 2 each has a heater housing 4 which comprises opposing legs 6 which are pivotably connected to one another via a heater housing base 8. On the side opposite the heater housing base 8, the heater housing 4 is open. It is usually surmounted by contact sheets 10, which are in direct contact with a PTC element 12 in an electrically conductive manner and form connecting lugs 14 as contact tongues for the plug-in contacting of the PTC heating device 2, formed in one piece by punching and bending a sheet metal material forming the contact sheets 10. These terminal lugs 14 are in Figure 2 shown. In the other representations after the Figures 3 ff. the connection lugs were not given any details.

Like the sectional view according to Figure 2 mediated, the PTC element 12 is located in a circumferentially enclosed receptacle of a position frame 16 made of insulating material, of which in Figure 1 only the upper and lower frame bars 18, 20 can be seen. The PTC element 12 usually projects beyond the frame spars 18, 16 in the thickness direction, ie a thickness direction of the receiving pocket 116, so that the electrically conductive contact of the contact plates 10 on the PTC element 12 is not impaired by the positioning frame 16.

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

The above-described elements of the PTC heating device 2 are accommodated in the heater housing 4, which in the present case is formed from aluminum and produced by extrusion and cut to length. The width of this heater housing 4 corresponds in the present case approximately the width of the PTC element 12. The width direction extends transversely to the plane of representation Figure 2 . The further dimension of the PTC element 12 to be recognized here in addition to the thickness is the length. This extension roughly corresponds to the direction in which the PTC heating device 2 is inserted into the receiving pocket 116.

The in Figure 2 The right leg 6 of the heater housing 4 is thickened compared to the left leg and has a contact surface 26 which extends essentially transversely to the insertion direction and which is flat and continuous over the width of the heater housing 4. Above this contact surface 26, the right leg 6, like the left leg 6, is also designed as an essentially thin and flat plate.

The sectional view shows fixing lips 28 protruding from the base in the width direction, which protruded further in the transverse direction before the heater housing 4 was inserted into the receiving pocket 116 and were reshaped parallel to the inner surfaces 118 when the heater was inserted into the receiving pocket 16. These fixing lips 28 can act like barbs.

The heater housing 4 in the receiving pocket 116 is plastically deformed by the application of a force to the contact surface 26. With this plastic deformation, the heating rib 114 can also be permanently deformed. In any case, the plastic deformation results in a cold welding. For this purpose, it is possible to press against the contact surface 26 with a pressing force of between 1400 and 3000 Newtons. The aluminum material of the heater housing 4 flows through this and is materially connected to the inner surfaces 118 of the receiving pocket 116.

Usually, the components of the PTC heating device that are accommodated within the heater housing 4, namely the PTC element 12 previously inserted into the receptacle of the positioning frame 16, the contact plates 10 resting thereon and the insulating layer 22 as a unit between the legs 6 of the heater housing 4 introduced before this is introduced into the receiving pocket 116 and pressed therein.

the Figures 3 to 7 show variants of the heater housing 4. Otherwise, the same components as in the previous description are provided with the same reference numerals. In the representations after the Figures 3 to 7 the heater housing 4 with the components received therein is not yet fully inserted into the receiving pocket 116. Rather, it partially projects beyond the partition wall 108.

In the embodiment discussed above, the heater housing 4 forms legs 6 with flat outer surfaces. These outer surfaces, while diverging, are flat; H. even.

At the in Figure 3 The variant shown, the legs 6 are slightly convex. They have a radius of between 500 and 1000 mm. The fixing lips 28 are dispensed with in this exemplary embodiment. Instead of a positioning frame 16, only an electrically non-conductive plastic web 30 is provided between a bottom of the heating rib 114 and the PTC element 12. The contact surfaces 26 are formed on both sides of the PTC element 12 on the two legs 6. When the contact pressure is applied on both sides of the PTC element, the material forming the heater housing 4 flows and thus a more uniform connection between the heater housing and the inner surfaces 118. In addition, the PTC element 12 can be arranged in the center of the receiving pocket 116 so that the same heat discharge conditions prevail on both main side surfaces of the PTC element 12. The main side surface is that surface which extends in the longitudinal direction and in the width direction of the PTC element 12.

With the variant after Figure 4 A plurality of fixing lips 28 are formed opposite the main side surfaces of the PTC element 12. These are limited to the upper area of the PTC element 12. Otherwise, corresponds to that in Figure 4 shown third variant of the second variant after Figure 3 .

In the fourth variant after Figure 5 fixing lips 28 are formed only in the area of the heater housing base 8. These fixing lips 28 deform, inter alia, in the bottom of the receiving pocket 116. Here, too, two contact surfaces 26 are formed. The outer surfaces of the legs 6 are convex.

In the Figure 6 The variant shown combines the variant according to the Figures 4 and 5 .

the Figure 7 shows a view of the entire width of the receiving pocket 116 and the PTC heating device 12. On the face of the PTC heating device, a certain gap remains to the front boundary of the receiving pocket 116. After the PTC heating device 2 has been inserted into the receiving pocket 116, the remaining space within the Receiving pocket 116 can be filled with a highly thermally conductive, usually electrically insulating compound.

Figure 7 illustrates an inwardly directed locking projection 32. This locking projection 32 is usually flat in the finished product in the direction of the PTC element 12, specifically against the insulating layer 22. The locking projection 32 can act in the manner of a barb, which prevents the PTC element 12 from being accidentally released from the heater housing 4. After the plastic deformation of the heater housing 4, this locking projection 32 is basically integrated into a flat contact surface which extends parallel to a main side surface of the PTC element 12 and in the present case forms a contact surface for the insulating layer 22.

List of reference symbols

2

PTC heating device

4th

Heater housing

6th

leg

8th

Heater housing bottom

10

Contact sheet / conductor tracks

12th

PTC element

14th

Connection lug

16

Position frame

18th

Upper frame spar

20th

Lower frame spar

22nd

Insulating layer

26th

Contact surface

28

Fixation lip

30th

Plastic bar

32

Locking protrusion

100

casing

102

Case back

104

Housing base

106

Housing cover

108

partition wall

110

Circulation chamber / heating chamber

112

Connection chamber

114

Heating rib

116

Receiving pocket

118

Inner surface

120

Connection piece

Claims (12)

Electric heater 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) protruding as a heating rib (114) into the heating chamber (110) protrudes, in which a PTC heating device (2) with at least one PTC element (12) and for energizing the PTC element (12) with different polarity with this electrically conductively connected conductor tracks (10) which are in the connection chamber (112) are electrically connected, are accommodated, the PTC element (12) and at least one of the conductor tracks (10) being accommodated in a heater housing (4), characterized, 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). Electric heating device according to Claim 1, characterized in that the heater housing (4) is connected to the receiving pocket (116) in a materially bonded manner and is preferably cold-welded. Electrical heating device according to Claim 1 or 2, characterized in that at least one surface of the heater housing (4) resting against the receiving pocket (116) is convex. Electrical 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 by pressing the heater housing (4) into the receiving pocket (116) in the direction of thickness by opposing inner surfaces (118) is limited, at least partially plastically deformed and placed against an inner surface (118) of the receiving pocket (116). Electrical heating device according to claim 4, characterized in that 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) on at least one the legs (6) and / or two fixing lips (28) formed on opposite sides of the heater housing base (8) are provided. Electrical heating device according to one of the preceding claims, characterized in that the heater housing (4) has, at a rear end in the press-in direction, a contact surface (26) which is adapted for the application of a pressing tool. Electrical heating device according to one of the preceding claims, characterized in that the heater housing (4) has at least one inwardly directed locking projection (32). Electrical heating device according to one of the preceding claims, characterized in that the heater housing is produced in the extrusion or extrusion process. A method for producing an electrical heating device comprising a housing with a partition which separates a connection chamber from a heating chamber for the emission of heat and from which at least one receiving pocket protrudes as a heating rib into the heating chamber, in which a PTC heating device with at least one PTC element and for energizing the PTC element with different polarity with this electrically conductively connected conductor tracks, which are electrically connected in the connection chamber, is included, with the method, the PTC element (12) and at least one of the conductor tracks (10) in 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 preferably is cold-welded to the receiving pocket (116). Method according to Claim 9, characterized in that the heater housing (4) is introduced into the receiving pocket (116) in such a way that a heater housing base (8) is plastically deformed in the bottom of the receiving pocket (116). Method according to Claim 9 or 10, characterized in 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) equipped in this way is introduced into the receiving pocket (116) will. The method according to claim 11, characterized in that the heater housing (4) is gripped for insertion by an insertion tool, by means of which the heater housing (4) under elastic or plastic deformation before the heater housing (4) is inserted into the receiving pocket (116) PTC element (12) is applied.

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