ELECTRIC HEATING DEVICE

Abstract

An electric heating device for, e.g., a motor vehicle, includes a heating module including at least one electric heating element that, in operation, generates heat when it is electrically supplied, a control housing of metal or alloy that delimits a control volume, and a power electronic, arranged in the control volume, for electrically supplying the heating module. The heating module includes an outer cover that surrounds the at least one electric heating element in a circumferential direction. The control housing has a pass opening through which a longitudinal end of the heating module is passed. The heating module is electrically connected to the power electronic in the control housing. A sealing arrangement is arranged in the pass opening between an inner jacket of the pass opening and the outer cover.

Claims

1. An electric heating device for a motor vehicle, comprising: a heating module including at least one electric heating element that, in operation, generates heat when it is electrically supplied, the heating module arranged in a heat transfer volume through which a flow path of a fluid passes, such that, in operation, the heating module and the fluid transfer heat, the heating module extending in a longitudinal direction, a control housing of metal or alloy that delimits a control volume, a power electronic for electrically supplying the heating module, the power electronic arranged in the control volume, the heating module further including an outer cover made of metal or alloy that surrounds the at least one electric heating element in a circumferential direction running circumferentially with respect to the longitudinal direction, the control housing having a pass opening through which a longitudinal end of the heating module is passed, the heating module electrically connected to the power electronic in the control housing, a sealing arrangement arranged in the pass opening between an inner jacket of the pass opening and the outer cover, wherein the sealing arrangement fluidically seals the control volume against the heat transfer volume and electrically insulates the outer cover from the control housing.

2. The electric heating device according claim 1, wherein the sealing arrangement includes an elastic sealing body, wherein the sealing body, for sealing the control volume against the heat transfer volume, is mechanically loaded and deformed.

3. The electric heating device according to claim 2, wherein the inner jacket and the outer cover mechanically load and deform the sealing body.

4. The electric heating device according to claim 2, further comprising a press body separate from the outer cover and the inner jacket mechanically loads and deforms the sealing body.

5. The electric heating device according to claim 2, wherein the sealing body is a molded part.

6. The electric heating device according to claim 5, wherein the pass opening is insert molded with the sealing body.

7. The electric heating device according to claim 2, wherein the sealing arrangement consists of the sealing body.

8. The electric heating device according to claim 1, wherein: the sealing arrangement includes an inelastic and electrically insulating plastic body that is arranged in the pass opening and forms a form closure with the pass opening, the plastic body is separate from the heating module, the plastic body has a body opening through which the heating module is passed into the control volume, wherein a fluidic inner path runs between the body opening and the outer cover, the sealing arrangement further includes an inner sealing element that is electrically insulating and fluidically seals the inner path, wherein the inner sealing element is separate from the plastic body and attached to the plastic body.

9. The electric heating device according to claim 8, wherein: the plastic body is separate from the control housing, wherein a fluidic outer path runs between the plastic body and the inner jacket, and the sealing arrangement further includes an outer sealing element that is electrically insulating and fluidically seals the outer path, wherein the outer sealing element is separate from the plastic body and attached to the plastic body.

10. The electric heating device according to claim 8, wherein the pass opening is insert molded with the plastic body.

11. The electric heating device according to claim 8, wherein the inner sealing element is at least one of an elastic sealing element and an adhesive.

12. A motor vehicle, comprising: an electric heating device, the electric heating device including: a heating module including at least one electric heating element that, in operation, generates heat when it is electrically supplied, the heating module arranged in a heat transfer volume through which a flow path of a fluid passes, such that, in operation, the heating module and the fluid transfer heat, the heating module extending in a longitudinal direction, a control housing of metal or alloy that delimits a control volume, a power electronic for electrically supplying the heating module, the power electronic arranged in the control volume, the heating module further including an outer cover made of metal or alloy that surrounds the at least one electric heating element in a circumferential direction running circumferentially with respect to the longitudinal direction, the control housing having a pass opening through which a longitudinal end of the heating module is passed, the heating module electrically connected to the power electronic in the control housing, a sealing arrangement arranged in the pass opening between an inner jacket of the pass opening and the outer cover, wherein the sealing arrangement fluidically seals the control volume against the heat transfer volume and electrically insulates the outer cover from the control housing.

13. The motor vehicle according to claim 12, wherein the sealing arrangement includes an elastic sealing body, wherein the sealing body, for sealing the control volume against the heat transfer volume, is mechanically loaded and deformed.

14. The electric heating device according to claim 13, wherein the inner jacket and the outer cover mechanically load and deform the sealing body.

15. The electric heating device according to claim 13, further comprising a press body, separate from the outer cover and the inner jacket, that mechanically loads and deforms the sealing body.

16. The electric heating device according claim 13, wherein: the sealing arrangement includes an inelastic and electrically insulating plastic body that is arranged in the pass opening and forms a form closure with the pass opening, the plastic body is separate from the heating module, the plastic body has a body opening through which the heating module is passed into the control volume, wherein a fluidic inner path runs between the body opening and the outer cover, the sealing arrangement further includes an inner sealing element that is electrically insulating and fluidically seals the inner path, wherein the inner sealing element is separate from the plastic body and attached to the plastic body.

17. The electric heating device according claim 16, wherein: a fluidic outer path runs between the plastic body and the inner jacket, and the sealing arrangement further includes an outer sealing element that is electrically insulating and fluidically seals the outer path, wherein the outer sealing element is attached to the plastic body.

18. The electric heating device according claim 17, wherein the outer sealing element is an elastic sealing element.

19. The electric heating device according claim 17, wherein the outer sealing element is an adhesive.

20. The electric heating device according claim 16, wherein the pass opening is insert molded with the plastic body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In the figures show, schematically in each case:

[0042] FIG. 1 a section through an electric heating device with a control housing and heating modules,

[0043] FIG. 2 an enlarged view of the heating device of FIG. 1 in the region of a heating module,

[0044] FIG. 3 the view of FIG. 2, in another exemplary embodiment,

[0045] FIG. 4 the view of FIG. 3, in a further exemplary embodiment.

DETAILED DESCRIPTION

[0046] An electric heating device 1, as shown exemplary in FIGS. 1 to 4, serves the purpose of heating a fluid, in particular air, by using electric heating elements (not visible), which generate heat when they are supplied with electric power. For this purpose, the electric heating device 1, also referred to as heating device 1 in the following, comprises a heat transfer volume 2 through which a flow path 3 of the fluid passes. The heating device 1 further comprises at least one heating module 4 arranged in the heat transfer volume 2. In the shown embodiment the heating device comprises, by way of example, four heating modules 4. The heating modules 4 extend in a longitudinal direction 5 and are distanced to each other transversely to the longitudinal direction 5. Each heating module 4 comprises at least one electric heating element, for instance a positive temperature coefficient element also known as PTC element. Thus, in operation, heat is transferred from the heating modules 4 to the fluid and the fluid hence heated. The respective heating module 4 comprises an outer cover 6 made of metal or alloy, in particular made of aluminum or aluminum alloy. The cover 4 is designed in a tube-like manner and encloses the at least one electric heating element of the corresponding heating module 4 in a circumferential direction 7 which runs circumferential with respect to the longitudinal direction 5. A housing 8 of the heating device 1 delimits a volume 9, also referred to as control volume 9 in the following. The housing 8 also referred to as control housing 8 in the following, separates the control volume 9 from the heat transfer volume 2. In the shown embodiment, the housing 8 comprises a bottom 10 that delimits both the control volume 9 and the heat transfer volume 2. A power electronic 11 of the heating device 1 is accommodated in the control volume 9 of the housing 8. The power electronic 11 supplies electric power to the heating modules 4, in particular to the electric heating elements. The power electronic 11 appropriately comprises at least one power transistor 12 and a printed circuit board 13 on which the at least one power transistor 12 is arranged in the known manner. In the shown example the power electronic 11, by way of example, has four power transistors 12.

[0047] The control housing 8 comprises, for each heating module 4 a corresponding opening 14. Each heating module 4 is passed through the corresponding opening 14, also referred to as pass opening 14 in the following, and is inserted into the control volume 9 with a longitudinal end 15. An electric connection of each heating module 4 with the power electronic 11 is realized within the control housing 8, for instance using electrical connectors 31 on the longitudinal end 15 of the respective heating module 4.

[0048] FIGS. 2 to 4 each show a section of the heating device 1 in the region of one of the pass openings 14. According to FIGS. 2 to 4, the heating device 1 comprises, for each pass opening 14 a corresponding sealing arrangement 16 not shown in FIG. 1. Each sealing arrangement 16 is arranged in the corresponding pass opening 14 between an inner jacket 17 of the pass opening 14 and the outer cover 6 of the corresponding heating module 4. Each sealing arrangement 16 runs closed in circumferential direction 7. Each sealing arrangement 16 fluidically seals the control volume 9 against the heat transfer volume 2 and therefore prevents fluids from flowing from the heat transfer volume 2 into the control volume 9 through the corresponding pass opening 14. Moreover, each sealing arrangement 16 electrically insulates the corresponding outer cover 6 from the control housing 8, in particular from the corresponding inner jacket 17.

[0049] In the exemplary embodiment of FIG. 2, the sealing arrangement 16 comprises an elastic and electrically insulating sealing body 18. In this exemplary embodiment, the sealing arrangement 16 consists of the sealing body 18. In this exemplary embodiment, the inner jacket 17 is stepped, by way of example. The sealing body 18 forms a form closure 19 with the pass opening 14 and is arranged between the outer cover 6 and the inner jacket 17. The sealing body 18 comprises an opening 20 referred to as aperture 20 in the following. The heating module 4 is passes through the aperture 20 into the control volume 9. In order to seal the control volume 9 against the heat transfer volume 2, the sealing body 18 is mechanically loaded and deformed. This load can be achieved by the inner jacket 17 and the outer cover 6. For instance, the heating module 4 can be press fitted through the aperture 20, such that the outer cover 6 mechanically loads and deforms the sealing body 18 against the inner jacket 17.

[0050] As shown in FIG. 2, as an alternative or in addition, a press body 21 separate from the outer cover 6 and from the inner jacket 17 can mechanically load and deform the sealing body 18. The press body 21 is arranged on the side of the sealing body 18 averted from the heat transfer volume 2. In the example shown, the press body 21 is arranged in the control volume 9.

[0051] The sealing body 18 is preferably a rubber made by injection molding. That is, the sealing body 18 is preferably a molded part 22. It is preferred if the pass opening 14 is insert-molded with the sealing body 18.

[0052] In the exemplary embodiments of FIG. 3 and FIG. 4, the sealing arrangement 16 comprises an inelastic and electrically isolating plastic body 23. The plastic body 23 is separate from the heating module 4 and is arranged in the pass opening 14. In the exemplary embodiment of FIG. 3 the inner jacket 17 comprises an inner and central projection 34. In the exemplary embodiments of FIG. 4 the inner jacket 17 is shaped flat. The plastic body 23 is arranged in the pass opening 14 between the inner jacket 17 and the outer cover 6 and forms a form closure 19 with the pass opening 14. The heating module 4 is passed through an opening 24 of the plastic body 23, also referred to as body opening 24 in the following. A fluidic path 25 between the outer cover 6 and the plastic body 23, also referred to as inner path 25 in the following, is sealed by a sealing element 26 of the sealing arrangement 16, also referred to as inner sealing element 26 in the following. The sealing element 26 is separate from the plastic body 23 and electrically insulating. The sealing element 26 is attached to, in particular applied on, the plastic body 23 and the outer cover 6. The plastic body 23 therefore acts as an interface for the sealing element 26 which carries the sealing element 26.

[0053] In the exemplary embodiment of FIG. 3 the sealing element 23 is an elastic sealing 27 which is mechanically loaded and deformed by a press body 21 arranged on the side of the sealing arrangement 16 averted from the heat transfer volume 2. In the example shown, the press body 21 is arranged in the control volume 9.

[0054] In the exemplary embodiment of FIG. 4 the sealing element 23 is an adhesive 28 applied to the plastic body 23 and the outer cover 6. As a consequence, there is no need for a press body 21 in this embodiment.

[0055] The plastic body 23 is advantageously a molded part 22. It is preferred if the pass opening 14 is insert-molded with the plastic body 23. In this way a possible fluidic path 29 between the inner jacket 17 and the plastic body 23, also referred to as outer path 29 in the following, is prevented, although the outer path 29 is shown in FIGS. 3 and 4. In this example the sealing arrangement 16 consists of the plastic body 23 and the inner sealing element 26.

[0056] In an alternative example, the plastic body 23 is separate from the control housing 8. This leads to said outer path 29 which is sealed by using a sealing element 30 of the sealing arrangement 16, also referred to as outer sealing element 30 in the following. The outer sealing element 30 is indicated in FIG. 3 only by dashed lines. The outer sealing element 30, like the inner sealing element 26, is separate from the plastic body 23 and attached to, in particular applied on, the plastic body 23 and the control housing 8. In this example the sealing arrangement 16 consists of the plastic body 23, the inner sealing element 26 and the outer sealing element 30.

[0057] Like the inner sealing element 26, the outer sealing element 30 can be an elastic sealing 27 that might be mechanically loaded using a press body 21, in particular the press body loading the inner sealing element 26, or an adhesive 28 applied on the plastic body 21 and the cover housing 8.

[0058] The heating device 1 is, by way of example, used in a motor vehicle 32, where it can serve as a supplement heater 33.