EP2393336B1 - Heat exchanger - Google Patents

Description

The invention relates to a heat exchanger according to the preamble of claim 1.

Consumption-optimized vehicles generate less and less waste heat, which is available for warming up the interior. Especially in the starting phase and at low outside temperatures it is necessary to heat up. For this purpose, in the prior art, inter alia, electric heaters with PTC heating elements are used, which make the conversion of electrical energy, for example from the electrical system of the vehicle into heat.

Special requirements are made of these electric PTC heaters. Thus, an electrical insulation of heat-dissipating elements of the PTC heater should be ensured up to 5000 VAC, while a high thermal conductivity of the electrically insulating elements, which is greater than 5 W / m / K, should be present. Also, a high temperature resistance of the electrically insulating elements of at least 200 ° C should be given and the heating network of the PTC heater should comply with the dust and water resistance of the protection class IP67.

With regard to the tightness of the housing disclosed EP 1 916 873 B1 an electric heater, which comprises a PTC heating element and an insulating housing surrounding the PTC heating element, wherein the housing comprises a housing shell element and a shell counter element, which abut each other with the interposition of a sealing strip applied to opposite end sides of the housing elements. The sealing element seals the housing elements against each other in an externally acting on the heat-generating element and the tracks against the PTC heating element pushing pressure force and surrounds the PTC heating element sealing.

In addition, it is in terms of electrical insulation EP 2 109 345 A1 known to cover each of the outer surfaces of the electrical conductor tracks with an insulating layer, which is fixedly connected to a surrounding the PTC heating element, insulating housing.

In EP 1 768 459 A1 . EP 1 768 458 B1 and EP 1 768 457 B1 In each case HV-PTC heaters are described in which the electrical insulation is effected in that the contact plates are each covered by an insulating layer, and that the insulating layers are connected to an insulating or positioning housing.

The EP 2 190 256 A1 discloses a heat exchanger for a motor vehicle, which has a housing in which at least one PTC heating element is arranged, which in each case adjoins a contact plate on opposite sides, wherein the at least one PTC heating element and the adjacent contact plates on the opposite sides are glued together so as to form a preassembled structural unit (8), wherein an insulation is provided between an inner wall of the housing and each of the contact sheets, wherein the insulation is also part of the preassembled unit.

However, the known in the prior art configurations of PTC heaters are structurally complex in terms of electrical insulation and dust or water resistance and thus expensive. Moreover, the configurations known in the art exist also a problem with regard to the positioning of the PTC heating elements both in the housing and against the insulation.

Therefore, it is the object of the present invention to provide a designed as an electric heater heat exchanger, in which on the one hand a water and dustproof, but not electrically insulating housing is provided and in which on the other hand, the PTC heating elements and adjacent contact plates both in the housing are positioned as well as against the insulation, which has a structurally simple and thus cost-effective construction.

The object of the present invention is achieved by a heat exchanger with the features of claim 1. Advantageous developments of the present invention are defined in the subclaims.

According to the invention, a heat exchanger, in particular an electric heater for a motor vehicle, is provided which has a housing in which at least one PTC heating element is arranged, which in each case adjoins a contact plate on opposite sides, wherein the at least one PTC heating element and the the opposite sides adjacent contact sheets are glued together so as to form a preassembled unit, wherein between an inner wall of the housing and each of the contact plates insulation is provided, the insulation is also part of the preassembled unit, wherein all contact surfaces of PTC heating element, the two contact plates and the insulation are glued together, and wherein the insulation is U-shaped.

By providing a preassembled unit consisting of at least one PTC heating element and the contact plates adjacent thereto on both sides, on the one hand a simple structure is achieved, on the other hand, the Position the pre-assembled unit in the housing as well as against the insulation in a simple way.

Preferably, the housing is dustproof and waterproof, so that a long life of the heat exchanger can be guaranteed.

According to a preferred embodiment, the housing is electrically conductive, in particular made of aluminum.

According to yet a preferred embodiment, the housing consists of two half-shells, which are tightly connected to each other, in particular glued, welded or folded, are.

According to yet another preferred embodiment, the housing is made as a closed tube, in particular of an extruded tube.

Moreover, according to yet another preferred embodiment, the insulation is made of polyimide, silicone, ceramic-filled silicone or ceramic, in particular alumina, aluminum nitride or boron nitride.

According to the invention, the insulation is U-shaped. The U-shaped design of the insulation makes it possible to position the preassembled unit and at the same time to space it from the electrically non-insulating housing.

According to a further preferred embodiment, a position profile is attached to the insulation.

The position profile is preferably made of an electrically insulating material, in particular of polyamide or silicone.

Moreover, it is also preferred if the position profile is fixed to the insulation by means of an adhesive.

According to yet another preferred embodiment, the position profile is formed self-adhesive or self-adhesive.

The position profile can also be fixed to the insulation by means of latching, sliding, gluing or extrusion coating.

Preferably, the contact plates are each connected to a position profile, which positions the preassembled unit both in the housing and against the insulation. In this embodiment, however, the at least one PTC heating element is not held by the position profile, because the at least one PTC heating element and the contact plates bonded thereto form the preassembled structural unit. Also by this position profile, the preassembled unit can be positioned both in the housing and against the insulation.

The position profile can be fixed according to yet another preferred embodiment by means of snapping, pushing, gluing or extrusion coating on the contact plate.

Fig.1A, 1B

jeweils eine Schnittansicht durch ein Gehäuse eines Wärmeübertragers gemäß einer nicht erfindungsgemäßen Ausführungsform;

Fig. 2A, 2B

jeweils eine Schnittansicht durch ein Gehäuse eines Wärmeübertragers gemäß einer erfindungsgemäßen Ausführungsform;

Fig. 3A, 3B

jeweils eine Schnittansicht durch ein Gehäuse eines Wärmeübertragers gemäß einer weiteren nicht erfindungsgemäßen Ausführungsform;

Fig. 4A, 4B

jeweils eine Schnittansicht durch ein Gehäuse eines Wärmeübertragers gemäß einer weiteren nicht erfindungsgemäßen Ausführungsform;

Fig. 5A, 5B

jeweils eine Schnittansicht durch ein Gehäuse eines Wärmeübertragers gemäß einer weiteren nicht erfindungsgemäßen Ausführungsform;

Fig. 6A, 6B

jeweils eine Schnittansicht durch ein Gehäuse eines Wärmeübertragers gemäß einer weiteren nicht erfindungsgemäßen Ausführungsform.

In the following the invention will be explained in detail by means of an embodiment with reference to the drawing. In the drawing show:

Fig.1A, 1B

each a sectional view through a housing of a heat exchanger according to a non-inventive embodiment;

Fig. 2A, 2B

each a sectional view through a housing of a heat exchanger according to an embodiment of the invention;

Fig. 3A, 3B

in each case a sectional view through a housing of a heat exchanger according to a further non-inventive embodiment;

Fig. 4A, 4B

in each case a sectional view through a housing of a heat exchanger according to a further non-inventive embodiment;

Fig. 5A, 5B

in each case a sectional view through a housing of a heat exchanger according to a further non-inventive embodiment;

Fig. 6A, 6B

in each case a sectional view through a housing of a heat exchanger according to a further non-inventive embodiment.

Fig.1A and Fig. 1B each show a sectional view through a housing 1 of a heat exchanger 2 according to a non-inventive embodiment, wherein the in Fig. 1A Housing 1 shown in two parts of two half-shells 3, 3 'is constructed, which are connected together tightly by gluing, and in Fig. 1B shown housing 1 is made in one piece from a closed, extruded tube. The housing 1 is made of aluminum in both cases. The structure and the arrangement of the individual elements of the heat exchanger 2 in the interior of the respective housing 1 is in the embodiments of Fig. 1A and Fig. 1B however identical and will only be based on the Fig. 1A explained. In this case, there is a plurality of PTC heating elements 5 in the housing 4, which is sealed in a watertight and dust-tight manner, in its interior space 4. On the opposite longitudinal sides 6, 6 'of the PTC heating elements 5, a contact plate 7, 7' is arranged in each case. The PTC heating elements 5 are glued to the contact plates 7, 7 'and thus form the preassembled unit 8. Between an inner wall 9 of the housing 1 and each contact plate 7, 7', an insulation 10, 10 'is arranged. The insulation 10, 10 'is in the embodiment of polyimide. Alternatively, however, the insulation may also be made of silicone, ceramic-filled silicone, or ceramic such as alumina, aluminum nitride, boron nitride. The insulation 10 and the insulation 10 'are spaced apart in the interior 4 of the housing. To the insulation 10, 10 'is in each case a position profile 11, 11' attached or glued thereto. When viewed in section, the insulation 10, 10 'forms a U-shaped element with a respective position profile 11, 11'. The assembly 8 consisting of the plurality of PTC heating elements 5 and the contact plates glued on both sides 7, 7 'is positioned by the described arrangement in a simple manner both in the housing 1 and against the insulation 10, 10'.

Fig. 2A, 2B each show a sectional view through a housing 1 of a heat exchanger according to an embodiment of the invention. Again, the only difference between the in Fig. 2A and Fig. 2B illustrated embodiment, the housing, which as already in connection with Fig. 1A and Fig. 1B has been explained in Fig. 2A two-piece and in Fig. 2B is formed in one piece. The arrangement of the elements in the interior 4 of the housing 1 shown here differs from the in Fig. 1A and Fig. 1B illustrated embodiment in that instead of the provision of a position profile 11, 11 ', the insulation 10, 10' itself each U-shaped and thus ensures the positioning of the preassembled unit 8 in the housing 1 and against the insulation 10, 10 '.

Fig. 3A, 3B each show a sectional view through a housing 1 of a heat exchanger 2 according to yet another non-inventive Embodiment. The Fig. 3A, 3B differ with respect to their housing 1 in the manner already described above. In the FIGS. 3A and 3B illustrated embodiment differs from the embodiments described so far in that the position profiles 11, 11 'here are not attached to the respective insulation 10, 10' and the insulation 10, 10 'is itself formed as a position profile sandem the position profiles eleventh , 11 'here are attached to the both sides of the PTC heating elements 5 adhered contact plates 7, 7', wherein the contact plates 7, 7 'of in FIGS. 3A and 3B on its respective first end portion 12, 12 'and second end portion 13, 13' with a respective position profile 11, 11 'by encapsulation of the first end portion 12, 12' and the second end portion 13, 13 'or snapping, sliding or gluing to the first end portion 12, 12 'and the second end portion 13, 13' are provided.

Fig. 4A, 4B each show a sectional view through a housing 1 of a heat exchanger 2 according to another embodiment not according to the invention. The Fig. 4A, 4B differ with respect to their housing 1 in the manner already described above. In this embodiment as well, the position profiles 11, 11 'are attached to the contact plates 7, 7', in which case the position profiles 11, 11 'have been glued to the respective contact plates 7, 7'.

Fig. 5A, 5B each show a sectional view through a housing 1 of a heat exchanger 2 according to another embodiment not according to the invention. The Fig. 5A, 5B differ with respect to their housing 1 in the manner already described above. The position profiles 11, 11 'are, as in the embodiments 3A, 3B, latched onto the respective contact plates 7, 7', slid, encapsulated or adhesively bonded. In addition, it can be seen that the insulation 10, 10 'at a first end portion 14, 14' respective first recesses 15, 15 'and at a second end portion 16, 16 'respective second recesses 17, 17', in which the position profiles 11, 11 'are also included.

Fig. 6A, 6B each show a sectional view through a housing 1 of a heat exchanger 2 according to another embodiment not according to the invention. In this embodiment, the PTC heating element 5, the two contact sheets 7, 7 'and the insulation 10, 10' form a preassembled unit, the manufacturing process ensuring the relative positioning of these components to one another. In particular, all contact surfaces of PTC heating element, the two contact plates 7, 7 'and the insulation 10, 10' are glued together. The preassembled unit consisting of the PTC heating element 5, the two contact plates 7 and 7 'and the insulation 10, 10' is formed by the two end portions of the insulation in the housing (formed as a closed tube ( Fig. 6B ) or as two half-shells ( Fig. 6A )).

Overall, PTC heating elements can be positioned in a watertight and dust-tight housing with the heat exchanger 1 designed in this way in a structurally simple and thus cost-effective manner.

Claims (6)

1. A heat exchanger (2), in particular an electric auxiliary heater for a motor vehicle, having a housing (1) in which at least one PTC heating element (5) is arranged which, on opposite sides, is respectively adjacent to a contact sheet (7, 7'), wherein the at least one PTC heating element (5) and the contact sheets (7, 7') being adjacent on the opposite sides are glued together so as to form a preassembled component (8), wherein an insulation (10, 10') is provided between an inner wall (9) of the housing (1) and each of the contact sheets (7, 7'), wherein the insulation (10, 10') is also part of the preassembled component, characterised in that all contact areas of PTC elements, the two contact sheets (7, 7') and the insulation (10, 10') are glued together and wherein the insulation (10, 10') is U-shaped.
2. The heat exchanger (2) according to claim 1, characterised in that the housing (1) is dustproof and waterproof.
3. The heat exchanger (2) according to claim 1 or 2, characterised in that the housing (1) is made from electrically conductive material, in particular aluminium.
4. The heat exchanger (2) according to one or more of claims 1 to 3, characterised in that the housing (1) consists of two half shells (3, 3') which are tightly joined together, in particular glued, welded or seamed.
5. The heat exchanger (2) according to one or more of claims 1 to 3, characterised in that the housing (1) is made as a closed tube, in particular from an extruded tube.
6. The heat exchanger (2) according to one of the preceding claims, characterised in that the insulation (10, 10') is made from polyimide, silicone, silicone filled with a ceramic or ceramic, in particular aluminium oxide, aluminium nitride or boron nitride.

Images