HIGH VOLTAGE HEATER WITH WELDED TUBES

Abstract

A high-voltage heater for a motor vehicle for heating a coolant is disclosed. The high-voltage heater includes at least two flat tubes that are flowable through by the coolant and at least one heating element. The at leas two flat tubes and the at least one heating element are alternatingly stacked on top of one another in a stacking direction to form a stack. The at least one heating element is connected at least to one of the adjacent flat tubes in the stack in a heat-transferring manner.

Claims

1. A high-voltage heater for a motor vehicle for heating a coolant, comprising: at least two flat tubes that can be flowed through by the coolant and at least one heating element, wherein the at least two flat tubes the at least one heating element are alternatingly stacked on top of one another in a stacking direction to form a stack, and wherein the at least one heating element is connected at least to one of the adjacent flat tubes in the stack in a heat-transferring manner.

2. The high-voltage heater according to claim 1, further comprising: two bottoms oriented transversely to the stacking direction and opposite to one another, and two lids oriented transversely to the stacking direction and opposite to one another, wherein the two lids are connected to the two bottoms in a fluid-tight manner and each delimit a respective box towards the outside, and at least two flat tubes fluidically lead through the two bottoms into the respective box and fluidically connect the respective boxes with one another.

3. The high-voltage heater according to claim 1, wherein: the at least two flat tubes each comprise two end regions on a longitudinal end side and a middle region situated between the two end regions, at least one of the at least two flat tubes comprises an offset at least on one of the two end regions, and a distance of the at least one flat tube with the offset and another one of the at least two flat tubes that are adjacent in the stacking direction is greater in the two end regions via the offset than in the middle region.

4. The high-voltage heater according to claim 2, further comprising: a housing arranged round about the stack, the housing arranged transversely to the stacking direction between the two bottoms, and the housing connected in a fluid-tight manner to the two bottoms each via an elastic ring seal or a bonding.

5. The high-voltage heater according to claim 2, wherein at least one of: the two bottoms and the at least two flat tubes are integrally connected to one another, the two lids are integrally connected to the two bottoms, and the two lids are firmly connected to the two bottoms in a positive locking or non-positive locking manner, wherein between the two lids and the two bottoms each a seal is arranged and clamped in a sealing manner.

6. The high-voltage heater according to claim 1, further comprising: a circuit board with at least one semi-conductor element, the circuit board is contacted with the at least one semi-conductor element in an electrically conductive manner, and the at least one semi-conductor element is connected to at least one of the at least two flat tubes in a heat-transferring manner.

7. The high-voltage heater according to claim 6, characterised further comprising: a holding frame that carries the at least one semi-conductor element and the circuit board, and the holding frame is firmly connected to at least one of a housing of the high-voltage heater and the stack of the high-voltage heater.

8. The high-voltage heater according to claim 1, wherein: the at least one heating element is a PTC heating element, the PTC heating element comprises at least one PTC stone, two electrically conductive contact plates and two dielectric insulating plates, the at least one PTC stone is arranged between the two contact plates and contacted with the two contact plates in an electrically conductive manner, and the two insulating plates are arranged on the two contact plates facing away from the at least one PTC stone.

9. The high-voltage heater according to claim 1, wherein: the at least one heating element is a TFR heating element the TFR heating element comprises a substrate, a single-layer or multi-layer first dielectric insulation layer, a resistance track and a single-layer or multi-layer second dielectric insulation layer, and the first insulation layer is applied to the substrate, the resistance track to the first insulation layer and the second insulation layer to the resistance track.

10. The high-voltage heater according to claim 9, wherein the substrate of the TFR heating element is provided by at least one of the two flat tubes.

11. The high-voltage heater according to claim 1, wherein: the at least one heating element is a film heating element, the film heating element comprises a first dielectric insulation film, a resistance track and a second dielectric insulation film, and the resistance track is arranged between the first insulation layer and the second insulation layer.

12. A motor vehicle, comprising: a high-voltage heater for heating a coolant, the high-voltage heating including: at least two flat tubes flowable through by the coolant and at least one heating element; the at least two flat tubes and the at least one heating element being alternately stacked on top of one another in a stacking direction to form a stack with the at least one heating element arranged between the at least two flat tubes; and wherein the at least one heating element is connected to at least one of the two flat tubes in the stack in a heat-transferring manner.

13. The motor vehicle according to claim 12, wherein the high-voltage heater further includes two bottoms oriented transversely to the stacking direction and opposite to one another, and two lids oriented transversely to the stacking direction and opposite to one another; the two lids connected to the two bottoms in a fluid-tight manner and each delimit a respective box towards the outside; and the at least two flat tubes fluidically lead through the two bottoms into the respective box and fluidically connect the respective boxes with one another.

14. The motor vehicle according to claim 13, wherein: the at least two flat tubes each comprise two end regions on a longitudinal end side and a middle region disposed between the two end regions; at least one of the at leas two flat tubes comprises an offset on at least one of the two end regions; and a distance of the at least one flat tube with the offset and another one of the at least two flat tubes is greater in the two end regions via the offset than in the middle region.

15. The motor vehicle according to claim 13, wherein the high-voltage heater further includes a housing arranged about the stack, the housing being arranged transversely to the stacking direction between the two bottoms, wherein the housing is connected in a fluid-tight manner to the two bottoms each via an elastic ring seal or a bonding.

16. The motor vehicle according to claim 13, wherein at least one of: the two bottoms and the at least two flat tubes are connected to one another by a connection that is welded, laser-welded, soldered, or glued; the two lids are connected to the two bottoms by a connection that is welded, laser-welded, soldered, or glued; and the two lids are firmly connected to the two bottoms, wherein a seal is provided between the two lids and between the two bottoms.

17. The motor vehicle according to claim 12, wherein the high-voltage heater further includes a circuit board with at least one semi-conductor element; the circuit board is contacted with the at least one semi-conductor element in an electrically conductive manner; and the at least one semi-conductor element is connected to at least one of the at least two flat tubes in a heat-transferring manner.

18. The motor vehicle according to claim 17, wherein the high-voltage heater further includes a holding frame that carries the at least one semi-conductor element and the circuit board; and wherein the holding frame is firmly connected to at least one of a housing of the high-voltage heater and the stack of the high-voltage heater.

19. The motor vehicle according to claim 12, wherein: the at least one heating element is a PTC heating element; the PTC heating element comprises at least one PTC stone, two electrically conductive contact plates, and two dielectric insulating plates; the at least one PTC stone is arranged between the two contact plates and contacted with the two contact plates in an electrically conductive manner; and the two insulating pates are arranged on the two contact plates facing away from the at least one PTC stone.

20. The motor vehicle according to claim 12, wherein: the at least one heating element is a TFR heating element; the TFR heating element comprises a substrate, a single-layer or multi-layer first dielectric insulation layer, a resistance track, and a single-layer or multi-layer second dielectric insulation layer; and the first insulation layer is disposed on the substrate, the resistance track is disposed on the first insulation layer, and the second insulation layer is disposed on the resistance track.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] It shows, in each case schematically:

[0025] FIGS. 1 and 2 a view and an exploded view of a high-voltage heater according to the invention;

[0026] FIGS. 3 and 4 a view and an exploded view of a stack in the high-voltage heater according to the invention;

[0027] FIG. 5 a view of a heating element in the stack according to FIG. 3 and FIG. 4 in the form of a TFR heating element;

[0028] FIG. 6 a view of a flat tube with the printed-on TFR heating element according to FIG. 5;

[0029] FIGS. 7 and 8 a plan view and a lateral view of the heating element in the stack according to FIG. 3 and FIG. 4 in the form of a PTC heating element;

[0030] FIG. 9 a plan view of a heating element in the stack according to FIG. 3 and FIG. 4 in the form of a film heating element;

[0031] FIGS. 10 to 13 views of the high-voltage heater according to the invention each in a partly constructed state.

DETAILED DESCRIPTION

[0032] FIG. 1 shows a view of a high-voltage heater 1 according to the invention. In FIG. 2, an exploded view of the high-voltage heater 1 is shown. The high-voltage heater 1 includes a stack 2 having multiple—here three—flat tubes 3 and having multiple—here two—heating elements 4. The flat tubes 3 and the heating elements 4 are alternatingly stacked in a stacking direction SR, wherein the heating elements 4 lie against the respective adjacent flat tubes 3 in a heat-transferring manner. The construction of the stack 2 is explained in more detail in the following by way of FIGS. 3 and 4.

[0033] Further, the high-voltage heater 1 comprises two bottoms 5a and 5b and two lids 6a and 6b. The bottoms 5a and 5b are connected to the lids 6a and 6b in a fluid-tight manner, so that boxes 7a and 7b are formed. In the box 7a, a coolant inlet 8a and in the box 7b a coolant outlet 8b are formed. Here, the flat tubes 3 fluidically lead on the one hand into the bottom 5a and thus into the box 7a and on the other hand into the bottom 5b and thus into the box 7b. The flat tubes 3 are connected integrally and in a fluid-tight manner to the respective bottoms 5a and 5b.

[0034] The high-voltage heater 1 is provided for heating a coolant. In the process, the coolant flows via the coolant inlet 8a into the box 7a and then into the flat tubes 3. From the flat tubes 3, the coolant flows into the box 7b and via the coolant outlet 8b out of the box 7b. When flowing through the flat tubes 3, the coolant is heated by means of the heating elements 4 that are connected to the flat tubes 3 in a heat-transferring manner. In the following, the construction of the heating elements 4 is explained in more detail by way of FIG. 5 to FIG. 9.

[0035] For controlling the heating elements 4, the high-voltage heater 1 comprises a circuit board 9 with multiple semi-conductor elements 10. The circuit board 9 is attached in the high-voltage heater 1 by means of a holding frame 11. The attachment of the circuit board 9 and of the holding frame 11 is explained in more detail in the following by way of FIG. 10 to FIG. 13. The circuit board 9 is electrically contacted with the two heating elements 4 by means of current conductor rails 12 and is electrically conductible towards the outside by means of a connector 13.

[0036] Further, the high-voltage heater 1 comprises a housing 14. The housing 14 can be formed out of aluminium for improving EMC or out of plastic. The housing 14 is arranged between the boxes 8a and 8b and firmly connected to the bottoms 5a and 5b in each case in a fluid-tight manner—for example by means of a ring seal. In this exemplary embodiment, the housing 14 is formed in two parts and comprises a housing part 14a and a housing part 14b. The housing parts 14a and 14b are screwed to one another and because of this firmly connected. Between the two housing parts 14a and 14b an elastic seal can be clamped, which seals the housing 14 towards the outside. Alternatively, the two housing halves 14a and 14b can be glued to one another and additionally screwed to one another.

[0037] FIG. 3 shows a view and FIG. 4 shows an exploded view of the stack 2 in the high-voltage heater 1 according to the invention. In this exemplary embodiment, the stack 2 is formed out of the three flat tubes 3 and out of the two heating elements 4. Here, the heating elements 4 are arranged between the flat tubes 3 and connected to the respective adjacent flat tubes 3 in a heat-transferring manner. The heating elements 4 can be printed onto one of the adjacent flat tubes 3 or crimped to the two adjacent flat tubes 3 in the stacking direction SR or glued to the two adjacent flat tubes 3 by means of a heat-conductive adhesive.

[0038] The respective flat tube 3 comprises two end regions 3a and 3b on the longitudinal end side adjacent to the bottoms 5a and 5b and a middle region 3c situated between the end regions 3a and 3b. The two flat tubes 3 situated on the outside in the stack each comprise an offset 15a and 15b in the end regions 3a and 3b. The middle flat tube 3 by contrast does not comprise an offset. Because of this, the respective adjacent flat tubes 3 are a greater distance apart in the end regions 3a and 3b than in the middle regions 3c. Because of this, the heating elements 4 can be arranged lying against the middle regions 3c in a heat-transferring manner and yet sufficient bottom material for connecting the flat tubes 3 to the bottoms 5a and 5b can be provided. Further, the cassetting of the flat tubes 3 can thus be simplified.

[0039] Further it is noticeable in FIG. 3 and in FIG. 4 that the flat tubes 3 comprise ribs 16 located inside. By way of the ribs 16 located inside, the coolant can be guided in the flat tubes 3 and because of this the heat exchange in the high-voltage heater 1 improved. The respective flat tube 3 can be an extruded profile or a welded tube.

[0040] FIG. 5 shows a view of the heating element 4 in the form of a TFR heating element 17. FIG. 6 shows a view of the TFR heating element 17 on the flat tube 3. Here and further, elements that are not directly visible are marked with interrupted lines. The TFR heating element 17 comprises a first dielectric insulation layer 18a, a resistance track 19 and a second dielectric insulation layer 18b. The insulation layers 18a and 18b can be single-layer or multi-layer. The resistance track 19 is arranged between the insulation layers 18a and 18b and because of this electrically insulated towards the outside and from the respective adjacent flat tubes 3. The TFR heating element 17 can be applied onto a substrate—for example printed on. In FIG. 6, the TFR heating element 17 is applied with the differently formed resistance track 19 onto the flat tube 3 and because of this connected to the flat tube 3 in a heat-transferring manner.

[0041] FIG. 7 shows a plan view of the heating element 4 in the form of a PTC heating element 20. FIG. 8 shows a lateral view of the PTC heating element 20. Here, the PTC heating element 20 comprises multiple PTC stones 21, two electrically conductive contact plates 22a and 22b and two dielectric insulating plates 23a and 23b. The PTC stones 21 are arranged between the contact plates 22a and 22b and the contact plates 22a and 22b with the PTC stones 21 are arranged between the insulating plates 23a and 23b. Because of this, the PTC heating element 20 is electrically insulated towards the outside and from the respective adjacent flat tubes 3. The PTC heating element 20 can be glued to the adjacent flat tubes 3 in a heat-transferring manner by means of a heat-conductive adhesive or crimped between the adjacent flat tubes 3.

[0042] FIG. 9 shows a plan view of the heating element 4 in the form of a film heating element 24. The film heating element 24 comprises two insulation films, between which a resistance track is arranged. The film heating element 24 is thus electrically insulated by the insulation films towards the outside and from the respective adjacent flat tubes 3. The film heating element 24 can be glued to the at least one flat tube 3 in a heat-transferring manner for example by means of a heat-conductive adhesive or be crimped between the two adjacent flat tubes 3 in a heat-transferring manner.

[0043] FIG. 10 to FIG. 13 show views of the high-voltage heater 1 according to the invention each in a partly constructed state.

[0044] In FIG. 10, the stack 2 is fluidically connected to the two bottoms 5a and 5b. Further, the housing 14b of the housing 14 is firmly connected to the two bottoms 5a and 5b.

[0045] In FIG. 11, the semi-conductor elements 10 of the circuit board 9 are arranged on the flat tube 3 situated on the outside in a heat-transferring manner. The semi-conductor elements 10 can be glued to the flat tube 3 in a heat-transferring manner by means of a heat-conductive adhesive or be pressed against the flat tube 3 in a heat-transferring manner by means of the holding frame 11—see FIG. 13 in this regard. Because of this, the semi-conductor elements 10 can also be cooled by the coolant.

[0046] In FIG. 12, the holding frame 11 is arranged on the flat tube 3 situated on the outside and presses the semi-conductor elements 10 against the flat tube 3 in a heat-transferring manner. In the holding frame 11, legs 25 of the semi-conductor elements 10 are additionally guided, which simplifies the cassetting of the circuit board 9.

[0047] In FIG. 13, the circuit board 9 is now arranged on the holding frame 11 and screwed to the holding frame 11. The current conductor rails 12 connect the circuit board 9 with the two heating elements 4. When, here, the two lids 6a and 6b, the connectors 13 and the housing part 14a are attached, the high-voltage heater 1 according to FIG. 1 is obtained.