EP1926346B1 - Electrical heating device, particularly for vehicles - Google Patents

Description

The invention relates to an electrical heating device with PTC elements, in particular for a motor vehicle.

A known embodiment of PTC heating devices has strip or cuboid PTC elements, the electrical contacting contacting plates and possibly corrugated ribs to increase the heat transfer surface. Here, the PTC elements between contact plates and / or corrugated ribs are arranged. The air to be heated absorbs the heat emitted by the PTC elements substantially from the expansion of the heat transfer surface provided corrugated fins. The PTC elements may be plastic or ceramic elements.

An example of such an embodiment is shown in FIG EP 1 522 439 A1 disclosed. Here, the arranged between the contact plates PTC elements and arranged on the outside of the contact plates corrugated fins are held in an electrically insulating plastic frame.

Another example is document: WO2005 / 049349

The electrical contacting of the contact sheets can be effected in that the contact plates protrude laterally from the frame and a plug connection is provided, wherein the frame can be designed accordingly. However, the contact sheets can also be connected within the frame with contact rails, which are contacted from the outside, or an electrical conductor is inserted directly into the frame and connected to the contact bars or contact plates.

The EP 1 452 357 A1 discloses an electric heater having heating zones, wherein the division into heating zones is provided in rows and columns. Although separately controllable groups of PTC elements are connected via a common contact plate with the positive terminal or the ground (negative pole), the structure is relatively complicated to be able to arrange the electrical connections for supplying power to the separate contact plates respectively on the same side of the heater ,

Such a heating device can still be desired in terms of a multi-zonal design.

It is an object of the invention to provide an improved electrical heating device with electrical heating elements, in particular PTC elements available.

This object is achieved by an electric heating device with the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

According to the invention, an electric heating device is provided, in particular for a motor vehicle, having a heat transfer area for transferring the heat generated to a fluid flowing through the electric heating device, in particular preferably air, wherein Heat transfer region a number of arranged between contact plates, electric heating elements, in particular PTC elements, particularly preferably ceramic PTC elements or plastic PTC elements, provided, and disposed between two contact plates in addition to at least one electrical heating element at least one electrically insulating element. The electric heating elements are used according to the invention for forming a heating zone and the insulating elements for forming a non-heat-generating region with applied voltage between the two contact plates. The function of the contact plates can also be taken directly by the heat-transmitting surface enlarging corrugated fins or areas thereof. Characterized in that at least one between two contact plates, in which no heating element is arranged, and at least one other area between these contact plates are provided with at least one heating elements, can be heated and unheated zones produce. By skillful arrangement and electrical contacting the individual areas can be arranged overlapping and yet be designed independently controllable, so that there is a heating device with different, independently heated zones. Furthermore, a plurality of heatable zones can be electrically contacted from one side of the heating device, so that, inter alia, there are also advantages in terms of installation space.

Preferably, the insulating element has at most the same dimension as the electric heating element in the direction of the contact sheets. Particularly preferred heating elements and insulating elements are formed with the same dimensions in all directions.

Preferably, at least one insulating element and at least one heating element, in particular preferably a PTC element, is glued in between two contact sheets. It can also be groups with more than one PTC element and / or insulating element, but preferably two and / or three groups. By providing adhesive bonds can be built in a very inexpensive and simple way, such a heating device. Particular preference is given to individual elements, such as the heating elements, insulating elements and contact plates, assemblies which preferably have symmetries.

The heating device preferably has at least two, in particular four or more zones. In this case, the zones are preferably arranged in individual rows and / or columns, two zones preferably being arranged on one side in the longitudinal direction of a contact sheet.

By providing insulating elements in the network itself, it is also possible to reliably avoid short circuits as a result of deformations of individual areas of the network, for example contact sheets.

The insulating element preferably has at most the same dimension as the electrical heating element in the direction of the contact sheets, i. it is at most as thick as an adjacent heating element.

The insulating element is preferably glued directly between two contact sheets. In this case, the insulating element is preferably designed such that the adhesive effect of the adhesive on its surface is at least as good as on the surface of the electrical heating elements, particularly preferably the adhesive effect on the surface of the insulating element is significantly greater than that of the electrical heating elements. By providing insulating elements between the contact plates, a firmer connection can thus be produced in a relatively simple manner, since the insulating elements can be prepared better and easier with respect to an adhesive connection than the PTC elements, in particular in FIG Case of ceramic PTC elements. Thus, the entire network connected by gluing becomes more stable.

In order to increase the adhesive effect of the adhesive on the contact surface of the insulating element, this contact surface is preferably formed uneven. The unevenness can be formed by larger and / or smaller structures. In particular, the surface may be roughened, provided with regular and / or irregular grooves, channels, wave structures, studded structures, impressions, holes and / or openings.

The insulating element may be - alternatively or in addition to Einklebenform- and / or non-positively connected to at least one of the contact plates. Also combinations are possible, i. For example, a contact plate is positively connected to the insulating element, the opposite contact plate is connected by means of an adhesive to the insulating member. A corresponding embodiment is possible in principle for the PTC elements.

For a positive connection, the insulating element is preferably formed with arms which laterally vorbeir on a contact plate. In this case, a contact engagement of the contact plate is particularly preferably also provided; in particular, this applies to insulating elements arranged at the end of the contact plates. A corresponding embodiment with arms can also be provided on both sides, ie the insulating element is approximately H-shaped. Alternatively, the insulating element may also be provided with at least one pin or at least one other, correspondingly acting projection which is inserted into an opening in the contact plate. Also in this case, protrusions may be provided on both contact surface sides of the insulating element, so that they hold together the two contact sheets with appropriate dimension and material choice or at least support the adhesive joints. The connection can Also be formed like a clip, ie at the insulating element is at least one spring arm with hooks o. formed, which is elastically deformed during assembly short term and in the assembled state, the contact plate engages behind and thereby secures the insulating element.

As PTC elements both ceramic PTC elements and plastic PTC elements can be used.

The provision of at least one insulating element at one end of a contact sheet can ensure that no short circuit due to deformation of the contact sheet in the direction of the adjacent, arranged on the other side of the heating elements contact plate due to the interposition of the insulating element.

The insulating element can be inexpensively injection molded. It can also be separated piece by piece with needs-based length of a profile.

The insulating element is preferably a plastic element, which in particular also brings advantages in terms of weight, but any other insulating materials are possible, such as, for example, ceramics.

The insulating element is preferably made of a softer material than the contact plate. This allows, for example, a pressing in openings in the contact plate.

The heating device preferably has corrugated ribs, which are mounted on one side of the contact sheets, in particular glued, and increase the heat-transferring area.

Furthermore, the heating device preferably has an insulating housing or a frame which holds the network of heating elements and possibly corrugated ribs. The frame or housing is preferably made of polyamide, more preferably PA66, and is injection molded. He or it may, with appropriate design, but in particular be designed in several parts, the individual parts can be connected to each other in a known manner, for example. By means Verclipsens or screwing. Particularly preferably, the insulating elements are made of the same material as the frame or the housing, in particular preferably injection-molded.

Heating devices according to the invention can be provided both as a heater in conjunction with a conventional air conditioner or a conventional heater as well as in isolation. The heating device can be arranged for example in the air guide housing of the air conditioner or directly in front of a vent.

Fig. 1

eine schematische Darstellung zur Erläuterung des Funktion einer erfindungsgemäßen Heizungsvorrichtung,

Fig. 2

eine schematische Darstellung einer Heizungsvorrichtung gemäß dem ersten Ausführungsbeispiel,

Fig. 3

eine schematische Darstellung zur Erläuterung des Funktion einer erfindungsgemäßen Heizungsvorrichtung mit verbesserter Wärmeübertragung,

Fig. 4

eine schematische Darstellung einer Heizungsvorrichtung gemäß dem zweiten Ausführungsbeispiel,

Fig. 5

eine schematische Darstellung einer Heizungsvorrichtung gemäß dem dritten Ausführungsbeispiel, bei dem an Stelle einer Steuerung mittels Relais eine Steuerung mittels Regler vorgesehen ist,

Fig. 6

eine schematische Darstellung der Heizungsvorrichtung von Fig. 5 bei einem 50%-igen Heizbetrieb der Zone 1,

Fig. 7

eine schematische Darstellung der Heizungsvorrichtung von Fig. 5 bei einem 100%-igen Heizbetrieb der Zone 1,

Fig. 8

eine schematische Darstellung der Heizungsvorrichtung von Fig. 5 bei einem 50%-igen Heizbetrieb der Zone 3, und

Fig. 9

eine schematische Darstellung der Heizungsvorrichtung von Fig. 5 bei einem 100%-igen Heizbetrieb der Zone 3.

In the following the invention will be explained with reference to two explanations illustrating the function and three embodiments, partially with variants, with reference to the drawing. In the drawing show:

Fig. 1

a schematic representation for explaining the function of a heating device according to the invention,

Fig. 2

a schematic representation of a heating device according to the first embodiment,

Fig. 3

a schematic representation for explaining the function of a heating device according to the invention with improved heat transfer,

Fig. 4

a schematic representation of a heating device according to the second embodiment,

Fig. 5

a schematic representation of a heating device according to the third embodiment, in which instead of a controller by means of a relay control is provided by means of controller,

Fig. 6

a schematic representation of the heating device of Fig. 5 in a 50% zone 1 heating operation,

Fig. 7

a schematic representation of the heating device of Fig. 5 in a 100% heating operation of Zone 1,

Fig. 8

a schematic representation of the heating device of Fig. 5 in a zone 50% heating mode, and

Fig. 9

a schematic representation of the heating device of Fig. 5 in a 100% heating operation of Zone 3.

Fig. 1 shows the schematic structure of a heating device 1 according to the invention, which is in principle suitable for a four-zone air conditioning, with appropriate contact or interconnection, however, for example, for two zones or only one zone can be used. Here are four corrugated fins 2, plate-shaped ceramic PTC elements 3, plate-shaped insulating elements 4 and contact plates 5 are provided. The function of the corrugated fins 2 is the enlargement of the heat-transferring surface, but they serve in the present case, the power transmission. The contact sheets 5 serve for the current input / output from the outside and / or the surface contacting of the PTC elements. The insulating ones Elements 4 serve essentially as non-heat generating and not current-carrying placeholder, so that in a Kontakblechpaar not over the entire length of the same (uniform) heat generation takes place, but a division into individual zones is possible.

In order to form the four zones, four PTC elements 3 and four insulating elements 4 are arranged in each case on two of the contact sheets 5, hereinafter also denoted by the reference numeral 5, wherein two PTC elements 3 adjacent to each other on one side are arranged, opposite a pair of insulating elements 4, so that there is a kind of checkered distribution of the groups of two.

The contact plates 5 ', which are arranged between the PTC elements 3 and the insulating elements 4, are used for electrical contacting and thus the power supply and thus the heat generation of the PTC elements 3, which are in contact with the same, if a current flow is possible , On the other side of the PTC elements 3 and of the insulating elements, which are spaced apart from the contact plate 5 ', there is in each case arranged a further contact plate 5 ", which essentially serves to increase the strength and has a heat and current passing function Direct electrical contacting from the outside A wave rib 2 is arranged on each side of the contact sheets 5 "spaced from the PTC elements 3 and the insulating elements 4. In principle, the contact plate 5 "could also be omitted, so that the corrugated fins can be attached directly to the elements 3 and 4.

On the side of the corrugated fins 2 spaced apart from the contact sheets 5 ", a further contact sheet 5 '" serving for electrical contacting is arranged in each case. The contact plates 5 'and 5 "', which serve the current input and - are derivative, longer than the contact plates 5" formed, where they stand on one side over the heating surface to allow electrical contact.

Preferably, the width of the elements 3 and 4 corresponds at most to that of the contact sheets 5, particularly preferably it is slightly smaller, so that in the assembled state, a small edge is provided on the outside. The length of the PTC elements 3 and the insulating elements can be chosen arbitrarily. The thickness of the elements 3 and 4 preferably corresponds to one another, it being possible for the insulating elements 4 to be designed somewhat thinner in order to be able to provide a thicker adhesive layer than in the case of the PTC elements 3. The average thickness, i. the thickness considering the uneven surface of the insulating members 4 is preferably slightly smaller than the thickness of the PTC elements 3.

The contact sheets 5, the PTC elements 3, the insulating elements 4 and the corrugated fins 2 are glued together in the present case. In order to improve the adhesive bond, the contact surface of at least the insulating elements 4 is roughened, so that the adhesive can adhere better and, at least in certain areas, a sufficient but not excessive film thickness can be ensured. An unevenness of the contact surface of the insulating elements can also by the provision of regular and / or irregular grooves, channels, wave structures, knob structures, indentations, holes, openings, or the like. be generated.

In order to allow the simplest possible structure with the same components, the structure is a total of mirror images of a central contact plate 5 is arranged. This also allows a relatively simple electrical contact, so that in the in Fig. 1 contacting the contact sheets 5 in the middle and on the sides with the positive pole, the contacting of the contact plates arranged therebetween with the negative pole (ground) can be effected.

A heating device 1 according to the first exemplary embodiment, constructed essentially from corresponding subassemblies, as in FIG Fig. 2 shown, serves as a heater in a four-zone automotive air conditioning system, where it is - seen in the air flow direction - presently arranged according to a conventional heater. Other arrangements are also possible. It has two of the above-described assemblies for more uniform heat generation across the heating surface, the two mirror-image sides of each assembly being equalized as a result of the illustrated electrical contacting so that each assembly has two zones, as in FIG Fig. 2 schematically indicated by a dash-dot line. The modules with two zones are arranged separately from each other and are controlled independently, so that said four heating zones zone 1, zone 2, zone 3 and zone 4 result, the zones 1 and 3 a common ground and the zones 2 and 4 have a common mass.

The heating device 1 has a two-part frame 6 made of plastic, in this case made of PA66, which is injection-molded. Integrated in the frame are two sockets for plugs for electrical contacting. In the middle of the frame is a bridge. In the frame 6, a plurality of the heat-transmitting surface enlarging corrugated fins 2, plate-shaped, arranged in groups of two ceramic PTC elements 3, plate-shaped, arranged in groups, insulating elements 4 and contact plates 5 are arranged, wherein two glued assemblies corresponding to those previously described assemblies are provided which are separated from each other in the installed state by the web. According to the present embodiment, the dimension of the insulating members 4 is selected according to the dimension of the PTC elements 3, but also different dimensions are possible.

The electrical contacting takes place as in Fig. 2 represented, wherein the contact plate 5 arranged centrally in the assembly shown on the left is connected to the power supply of the zone 1. The two outer contact plates 5 are connected to the power supply of the zone 3. Thus, in the case of a heating request exclusively to the zone 1 at a corresponding voltage applied to heat the four upper PTC elements 3, while the four lower PTC elements 3, which are assigned to the zone 3, are not flowed through by electricity and thus generate no heat , In the case of a heating request exclusively to the zone 3 at a correspondingly applied voltage, the four lower PTC elements 3 generate heat as a result of the current flow, while the four upper PTC elements 3, which are assigned to the zone 1, generate no heat. In the case of a heating request to both zones 1 and 3, all PTC elements 3 generate heat. The same applies to zones 2 and 4 on the other side of the bridge.

Fig. 3 shows a possibility of a further arrangement of the heat-transmitting surface enlarging corrugated fins 2, plate-shaped, in turn, in turn arranged in groups of ceramic PTC elements 3, plate-shaped, in this case again arranged in groups, insulating elements 4 and contact plates 5, wherein in contrast to the arrangement from Fig. 1 the PTC elements 3 and insulating elements 4 do not rest against a common contact plate 5, but to improve the heat transfer, the common contact plate 5 is replaced by an assembly of two contact plates 5 and a corrugated fin 2. This enables the heat generated by the PTC elements 3 to be dissipated on both sides of corrugated fins 2, so that the heating performance improves. In addition, the electrical contacting of the outermost row of PTC elements 3 by a corrugated fin height moved further inside, which brings advantages in terms of accessibility within the framework.

Fig. 4 shows two of the assemblies of Fig. 3 in a frame 6 with integrated receptacle for plug arranged as a second embodiment. The electrical contacting of the individual zones takes place essentially as described above, again four zones being provided. The control of such a heating device 1 is carried out by means of relays.

In Fig. 5 is provided as a third embodiment instead of a controller by means of a relay control by means of a regulator. The structure of the assemblies is not different from that of the embodiment described above. The controllers relevant for the power supply of the individual zones Zone 1, Zone 2, Zone 3 and Zone 4 are in Fig. 5 R1 to R4, where two controllers R3 and R4 are required for zones 3 and 4 respectively.

FIGS. 6 to 9 show the principle of a two-stage control with the help of regulators, where in Fig. 6 a 50% heating operation and in Fig. 7 a 100% heating operation of zone 1 is shown. Fig. 8 shows a 50% heating mode of Zone 3 and Fig. 9 a 100% heating operation of zone 3. The other zones are regulated accordingly. As a result of the mirror-image structure of the two modules can be relatively simple form a two-stage four-zone heating device 1 with appropriate contacting of the contact plates 5.

An increase in the number of zones is possible in the width direction as desired. Similarly, by providing, for example, two of the described assemblies for a total of only two instead of four zones, the zones could form a four-stage, two-zone heating device.

According to the above-described embodiments, ceramic PTC elements have been described as PTC elements, but plastic PTC elements may be used in place of ceramic PTC elements.

Further, in the above-described embodiments, two groups of PTC elements and insulating elements have been described, respectively. However, the group size can be chosen arbitrarily, preferably in the range of one to four. Likewise, the group size and in particular the length of the elements may differ, wherein preferably the group sizes of an element type and the shape of an element type are the same. With different design of individual PTC element groups also different heat level divisions can be generated, for example. The two stages 75% and 100%.

Claims (12)

1. An electric heating arrangement (1), in particular for a motor vehicle, with a heat transfer region for transferring the generated heat to a fluid which flows through the electric heating arrangement, wherein a number of electric heating elements, in particular PTC elements (3), arranged between contact sheets (5), is provided in the heat transfer region, characterised in that at least one insulating element (4) is arranged between two contact sheets (5) in the longitudinal direction of the contact sheets adjacent to at least one electric heating element, wherein the electric heating elements serve to form a heating zone and the insulating elements (4) serve to form a non-heat generating region of the heating arrangement (1) in case of a given voltage between the two contact sheets (5).
2. The heating arrangement according to claim 1, characterised in that the heating elements and insulating elements (4) arranged between two contact sheets (5) are assigned to different zones.
3. The heating arrangement according to claim 1 or 2, characterised in that the insulating element maximally has the same dimension as the electric heating element in the direction of the contact sheets (5).
4. The heating arrangement according to one of the preceding claims, characterised in that at least one insulating element (4) and at least one heating element are glued between two contact sheets (5).
5. The heating arrangement according to one of the preceding claims, characterised in that the heating arrangement (1) has at least two, in particular four or more zones.
6. The heating arrangement according to one of the preceding claims, characterised in that at least one insulating element (4) is arranged on at least one end of a contact sheet (5).
7. The heating arrangement according to one of the preceding claims, characterised in that the contact surface, in particular the glue surface, of the insulating element (4) with which it is arranged on a contact sheet (5) is uneven.
8. The heating arrangement according to claim 7, characterised in that the uneven surface is roughened, provided with regular and/or irregular grooves, channels, wave structures, knob structures, indentations, holes and/or openings.
9. The heating arrangement according to one of the preceding claims, characterised in that the insulating element (4) is a plastic element.
10. The heating arrangement according to one of the preceding claims, characterised in that the electric heating element is a PTC element (3), in particular a ceramic PTC element.
11. The heating arrangement according to one of the preceding claims, characterised in that the heating arrangement (1) has corrugated ribs (2) which are attached to a side of the contact sheet, in particular glued.
12. The heating arrangement according to one of the preceding claims, characterised in that the electric heating arrangement (1) has an insulating housing or a frame.

Images