Abstract
An electric heating device for a motor vehicle may include a heating volume and at least two spaced heating modules. A flow path of a fluid may lead through the heating volume. At least two spaced heating modules may be arranged in the heating volume. The at least two spaced heating modules may extend in a longitudinal direction. The at least two spaced heating modules may be spaced apart from one another in a transverse direction extending transversely to the longitudinal direction.
Claims
1. An electric heating device for a motor vehicle, comprising: a heating volume through which a flow path of a fluid leads; and at least two spaced heating modules arranged in the heating volume which extend in a longitudinal direction and are spaced apart from one another in a transverse direction extending transversely to the longitudinal direction; wherein each of the heating modules comprises at least one electrical heating element which generates heat when electrically supplied so that the heating module heats the fluid; wherein each of the heating modules has an electrically conductive outer shell which encloses the at least one heating element; wherein each outer shell has two opposite outer walls in the transverse direction and two opposing side walls in a vertical direction extending transversely to the longitudinal direction and transversely to the transverse direction; wherein the heating device further includes an electrically conductive control housing which delimits a control volume; wherein power electronics for electrically supplying the heating modules are arranged in the control volume; wherein the housing has a bottom which delimits the heating volume; wherein the bottom for the respective heating module has a passage opening through which the heating module penetrates into the control volume in the longitudinal direction; wherein the heating modules in the control volume are electrically connected to the power electronics; wherein the heating device has an electrically conductive conductor arrangement which electrically connects the respective outer shell to housing; wherein the conductor arrangement comprises a rail which runs in the transverse direction and is distanced to the outer shells; wherein the rail is electrically and mechanically connected to the bottom; and wherein the conductor arrangement for the respective outer shell comprises at least one associated arm which protrudes from the rail and is electrically and mechanically connected to the associated outer shell.
2. The heating device according to claim 1, wherein at least one of the arms is configured as a spring element which is mechanically loaded against the associated outer shell.
3. The heating device according to claim 1, wherein at least one of the arms is arranged on an associated outer side wall of the outer shell and is electrically connected to the side wall.
4. The heating device according to claim 3, wherein the side wall has a fillet projecting in the vertical direction and extending in the longitudinal direction; and the arm has a formation complementary to the fillet, so that the fillet engages in the formation.
5. The heating device according to claim 1, wherein: at least one of the arms has a support section running in the longitudinal direction and a connecting section connecting the support section to the rail; the support section rests on an associated outer wall of the corresponding outer shell; and the connecting portion extends inclined to the transverse direction in the direction of the associated outer wall and thus mechanically loads the supporting portion in the transverse direction against the associated outer wall.
6. The heating device according to claim 5, wherein the conductor arrangement comprises one such arm each for both outer walls of at least one of the outer shells.
7. The heating device according to claim 5, wherein the support section is spaced transversely to the longitudinal direction and transversely to the transverse direction from the rail.
8. The heating device according to claim 5, wherein at least one of the arms has, on the side of the support section facing away from the rail, a tongue which is bent outwards with respect to the associated outer wall.
9. The heating device according to claim 1, wherein the conductor arrangement is arranged in the heating volume and electrically connects the respective outer shell in the heating volume to the bottom for electrically connecting the respective outer shell to the housing part.
10. The heating device according to claim 1, wherein in the respective passage opening an insulating sealing arrangement fluidically seals the control volume with respect to the heating volume.
11. The heating device according to claim 1, wherein at least one of the arms is coated with a friction-resistant and conductive material on its side facing the associated outer shell.
12. The heating device according to claim 1, wherein the conductor arrangement comprises at least one lug element which protrudes from the rail and is mechanically loaded against the bottom, such that at least one of the at least one arms is mechanically loaded against the associated outer shell.
13. The heating device according to claim 1, wherein the conductor arrangement is a one piece part.
14. A motor vehicle, comprising: a heating device according to claim 1; wherein the control housing is electrically connected to an electrical ground of the motor vehicle.
15. The heating device according to claim 1, wherein each of the heating modules has an electrically conductive outer shell, in particular an electrically conductive flat tube (8
16. The heating device according to claim 1, wherein at least one of the arms is coated with silver.
17. The heating device according to claim 1, wherein the conductor arrangement is a sheet-metal part.
18. The vehicle according to claim 14, wherein the first housing part is electrically connected to an electrical ground of the motor vehicle.
19. The motor vehicle according to claim 14, wherein at least one of the arms is configured as a spring element.
20. The motor vehicle according to claim 14, wherein at least one of the arms is arranged on an associated outer side wall of the outer shell and is electrically connected to the side wall.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0075] The Figures show, in each case schematically
[0076] FIG. 1 shows an isometric view of an electric heating device,
[0077] FIG. 2 shows a highly simplified, schematic diagram of a motor vehicle with the heating device,
[0078] FIG. 3 shows a longitudinal section through the heating device in the area of a heating module,
[0079] FIG. 4 shows an isometric view of the heater in the direction of a bottom of a housing part of the heater,
[0080] FIG. 5 shows a top view of a part of the heating device,
[0081] FIG. 6 shows a section through a control housing of the heating device,
[0082] FIG. 7 shows an enlarged view of the area labeled VII in FIG. 6,
[0083] FIG. 8 shows an isometric view of a portion of the control housing in another exemplary embodiment,
[0084] FIG. 9 shows a top view of the heating device in a further exemplary embodiment,
[0085] FIG. 10 shows an isometric view of a portion of the heating device toward a first housing portion in another embodiment,
[0086] FIG. 11 shows a section through the heating device of FIG. 10
[0087] FIG. 12 shows an enlarged view of the area labeled XII in FIG. 11,
[0088] FIG. 13 shows an isometric view of the conductor arrangement of the heating device in FIG. 10,
[0089] FIGS. 14 and 15 show an isometric view of the heating device during an assembly step of the heating device of another exemplary embodiment, respectively.
DETAILED DESCRIPTION
[0090] An electric heating device 1, as shown for example in FIGS. 1 to 15, is used for heating a fluid. For this purpose, a flow path 2 of the fluid (see FIG. 1) leads through the electric heating device 1. The electric heating device 1 is also simply denoted heating device 1 in the following. At least two heating modules 3 of the heating device 1 are arranged in the flow path 2. The respective heating module 3 extends longitudinally in a longitudinal direction 4. The heating modules 3 are spaced apart from one another in a transverse direction 5 extending transversely to the longitudinal direction 4. The respective heating module 3 has at least one heating element 6 (see for instance FIG. 3). The heating element 6 is designed in such a way that it generates heat when electrically supplied during operation. As a result, the fluid is heated. The respective heating element 6 is designed, for example, as a PTC element, where PTC stands for “Positive Temperature Coefficient”. The respective heating module 3 further comprises an electrically conductive outer shell 7, which encloses the at least one heating element 6. In the exemplary embodiments shown, the respective outer shell 7 is formed as a flat tube 8. As can be seen, for example, from FIG. 1, the heating device 1 further comprises a housing 9, which is hereinafter referred to as the control housing 9. The control housing 9 is adjacent to a volume 10 through which the flow path 2 passes. The volume 10 is also referred to hereinafter as the heating volume 10. The control housing 9, in the exemplary embodiments shown, has a first housing part 11 and a second housing part 12. The first housing part 11 and the second housing part 12 delimit a volume 13 in the control housing 9 (see for instance FIG. 3), which is also referred to hereinafter as control volume 13. Power electronics (not shown) are arranged in the control volume 13, with which the respective heating module 3, in particular the heating elements 6, are electrically supplied. The housing parts 11, 12 are each electrically conductive. The first housing part 11 has a bottom 14 which delimits the heating volume 10 and thus separates it from the control volume 13. In the bottom 14, an associated opening 15 is provided for the respective heating module 3 (see in particular FIG. 3). The respective opening 15 is also referred to hereinafter as the passage opening 15. The respective heating module 3 is inserted in longitudinal direction 4 through the associated passage opening 5 and thus enters the control volume 13. Within the control volume 13, the respective heating module 3 is further electrically connected to the power electronics (not shown) in order to electrically supply the heating elements 6. As can be seen in particular from FIG. 3, a sealing arrangement 16 is arranged in the respective passage opening 15 between the outer shell 7 and the passage opening 15, which fluidically seals the control volume 13 from the heating volumes 10. Preferably, the sealing arrangement 16 further electrically isolates the outer shell 7 from the first housing part 11. In the exemplary embodiments shown, the respective sealing arrangement 16 has a single sealing body 17.
[0091] As can be seen, for example, from FIGS. 1, 7 and 8, the housing parts 11, 12 are electrically connected to one another. For this purpose, the respective housing part 11, 12 has an associated support surface 18, 19, the support surfaces 18, 19 resting on one another. That is, the first housing part 11 has a support surface 18 and the second housing part 12 has a support surface 19. The support surface 19 of the second housing part 12 is also referred to hereinafter as the counter-support surface 19 for better differentiation. As can be seen in particular from FIG. 7, the support surface 18 rests on the counter-support surface 19. This results in an electrical connection between the housing parts 11, 12. As can be seen, for example, from FIGS. 1 and 7, the support surface 18 and the counter-support surface 19 of the exemplary embodiments shown are each on the outside and circumferentially transverse to the longitudinal direction 4. Support surface 18 and counter-support surface 19 are thereby arranged outside the control volume 13 transversely to the longitudinal direction 4 and extend circumferentially.
[0092] As can be seen from FIG. 7, in the exemplary embodiments shown, one of the housing parts 11, 12 has a shoulder 20 projecting in the longitudinal direction 4 and the other housing part 11, 12 has an associated receptacle 21, which engage in one another in the manner of a tongue-and-groove connection 22. In the exemplary embodiments shown, the first housing part 11 has the receptacle 21 and the second housing part 12 has the shoulder 20. The shoulder 20 and the receptacle 21 are circumferential. As can further be seen from FIG. 7, the shoulder 20 and the receptacle 21 are arranged on the side of the support surface 18 and the counter-support surface 19 facing the control volume 13. As can also be seen from FIG. 7, the receptacle 21 is not completely filled with the shoulder 20. The receptacle 21 is filled, in particular before insertion of the shoulder 20, with an adhesive sealing compound, for example a silicone compound, which is not shown. This seals the control volume 13 from the outside.
[0093] According to FIGS. 1 and 6 and 7, a further electrical connection of the housing parts 11, 12 in the exemplary embodiments shown is made by a mechanical connection 23 of the housing parts 11, 12 to one another. As can be seen from FIGS. 1 and 9, two or more such connections 23 are provided, which are arranged circumferentially spaced apart from one another. In the embodiments of FIGS. 1 to 8, the respective connection 23 is formed by an electrically conductive spring closure 24. The spring closure 24 has a base 25, from each end of which a bend 26 is bent over, one of the bends 26 engaging in the first housing part 11 and the other bend 26 engaging in the second housing part 12. Thus, the housing parts 11, 12 are mechanically loaded against each other along the spring closure 24. As can be seen, for example, from FIG. 6, the respective housing part 11, 12 has a bead 27 for the respective associated bend 26, so that the bends 26 are secured to the respective associated housing part 11, 12. As can also be seen from FIG. 6, the respective base 25 of the exemplary embodiments shown extends in the longitudinal direction 4.
[0094] In the exemplary embodiment of FIGS. 1 to 6, the respective bend 26 associated with the second housing part 12 engages externally in the second housing part 12 in the longitudinal direction 4. The embodiment example shown in FIG. 8 differs from this in that the bends 26 associated with the second housing part 12 engage in the second housing part 12 offset in the longitudinal direction 4 towards the first housing part 11.
[0095] The exemplary embodiment shown in FIG. 9 differs from the embodiment examples shown in FIGS. 1 to 8 in that the respective connection 23 is formed by an indicated screw connection 28.
[0096] The respective outer shell 7 has two opposing outer walls 29 in the transverse direction 5. In addition, the respective outer shell 7 has two opposing side walls 31 in a vertical direction 30 extending transversely to the longitudinal direction 4 and transversely to the transverse direction 5. The side walls 31 connect the outer walls 29 to each other and vice versa.
[0097] As can be seen in particular from FIGS. 1 to 5 and 10 to 15, the heating device 1 has an electrically conductive conductor arrangement 32. The conductor arrangement 32 is separate from the sealing arrangements 16. The conductor arrangement 32 electrically connects the respective outer shell 7 to the first housing part 11. Thus, the outer shells 7 are electrically connected to the first housing part 11 and to each other. In addition, the outer shells 7 are electrically connected to the second housing portion 12. As a consequence, the outer shells 7 and the housing parts 11, 12 are connected to the same electrical potential. As can be seen from FIG. 2, the electrical potential is a ground 33. To this end, the heating device 1 is electrically connected to a corresponding ground 33. In the exemplary embodiment shown in FIG. 2, this is done by electrically connecting the first housing part 11 to the ground 33. For this purpose, a corresponding electrical plug socket 34 can be provided on the first housing part 11, as can be seen in FIG. 1. In the exemplary embodiment shown in FIG. 2, the heating device 1 is used in a motor vehicle 35, which is not otherwise shown. The first housing part 11 is electrically connected to the electrical ground 33 of the motor vehicle 35.
[0098] In the exemplary embodiments shown, the conductor arrangement 32 is disposed outside of the control volume 13 and within the heating volume 10. In the exemplary embodiments shown, the conductor arrangement 32 comprises a single, electrically conductive, one piece as well as monolithic conductor body 36. The conductor body 36 is made of an electrically conductive flat material, such as a sheet metal. In the exemplary embodiments shown, the conductor arrangement 32 is electrically connected to the bottom 14 of the first housing portion 11.
[0099] In conductor arrangement 32 has a rail 37 extending longitudinally in the transverse direction 5. The rail 37 abuts the bottom 14 at a distance from the passage openings 15 in the vertical direction 30 and is electrically connected to the bottom 14. The conductor arrangement 32 has an associated arm 38 for the respective outer shell 7. The respective arm 38 protrudes from the rail 37. The respective arm 38, in the exemplary embodiments shown, is designed as spring element 39 which is mechanically loaded against the associated outer shell 7.
[0100] As can be seen, for example, from FIG. 5, the conductor arrangement 32 in the exemplary embodiments shown is screwed into the bottom 14 by means of two electrically conductive screws 40 arranged on the outside in the transverse direction 5. For this purpose, the conductor arrangement 32 of the shown embodiments has a screw section 41 for the respective screw 40, through which the screw 40 is screwed. The screw sections 41 are arranged on the outside in the transverse direction 5 and project from the rail 37 in the vertical direction 30 on the side facing away from the arms 38.
[0101] In the exemplary embodiment shown in FIGS. 3 to 5, the respective arm 38 extends inclined with respect to the longitudinal direction 4 towards a side wall 31 of the associated outer shell 7, with the respective arm 38 resting in a planar manner on the associated side wall 31 and thus being electrically connected to the side wall 31. In addition, the respective arm 38 is mechanically connected to the associated side wall 31. For this purpose, the respective arm 38 and the associated side wall 31 may be welded together, for instance by laser welding or friction welding. As an alternative, for this purpose, the respective arm 38 and the associated side wall 31 may be adhered by means of an electrically conductive adhesive such as conductive silicone. As can further be seen, for example, from FIG. 4, the respective arm 38 is smaller in longitudinal direction 4 than the associated side wall 31. As can be seen from FIG. 4, the respective arm 38 thereby extends in transverse direction 5 at most over the side wall 31. This means that the respective arm 38 is smaller in transverse direction 5 or at most as large as the associated side wall 31. Thus, the flow of the fluid through the heating volume 6 is not influenced or is influenced as little as possible by the arms 38. As is further indicated in FIG. 4, the conductor arrangement 32 of the exemplary embodiment shown has at least one projecting lug element 48 on the side facing away from the arms 38 in the vertical direction 30. With the respective lug element 48, at least one of the arms 38 is mechanically loaded in the direction of the associated side wall 31. In the exemplary embodiment shown, the conductor arrangement 32 has a plurality of such lug elements 48, which are spaced apart from one another in the transverse direction 5. Thereby, the lug elements 48 are spaced apart from the arms 38 in the transverse direction 5 in the shown exemplary embodiment.
[0102] As can be seen, for example, from FIG. 4, in the exemplary embodiment shown the respective side wall 31 associated with the arms 38 has a fillet 32 projecting outwards and extending in the longitudinal direction 4. In this case, the respective arm 38 has a formation 43 complementary to the associated fillet 42, such that the respective fillet 42 is received in the associated formation 43. Thus, electrical contact also occurs between the respective fillet 42 and the associated formation 43.
[0103] In the exemplary embodiments shown in FIGS. 10 to 15 the respective arm 38 is associated with one of the outer walls 29 of the associated outer shell 7. The respective arm 38 thereby protrudes from the rail 37 in the direction of the associated outer wall 29. In addition, the respective arm 38 rests on the associated outer wall 29 and is mechanically loaded, in particular pre-stressed, against the outer wall 29 in the transverse direction 5. In the exemplary embodiments shown in FIGS. 10 to 15, such an arm 38 is associated with the respective outer wall 29. The conductor arrangement 32 thus has two such arms 38 for the respective outer shell 7. As indicated by two arrows in FIG. 12, the two arms 38 and thus spring elements 39 are thus mechanically loaded and pre-stressed in opposite directions in the transverse direction 5. This results in a simple and stable electrical connection of the spring elements 38 with the outer shell 7.
[0104] As can be seen, for example, from FIGS. 13 to 15, the respective arm 38 in the exemplary embodiments shown in FIGS. 10 to 15 has a section 45 which rests flat on the associated outer wall 29. This section 45 is also referred to hereinafter as the support section 45. In the exemplary embodiments shown in FIGS. 10 to 15, the respective arm 38 also has a section 46 which connects the support section 45 to the rail 37. This section 46 is also referred to hereinafter as the connecting section 46. The respective support section 45 extends in the longitudinal direction 4. The respective connecting section 46 extends inclined to the transverse direction 5 in the direction of the associated outer wall 29, so that by means of the connecting section 46 a mechanical pretension or load can be generated against the associated outer wall 29. In the exemplary embodiment shown in FIGS. 10 to 15, the respective support section 45 is spaced apart from the rail 37 in the longitudinal direction 4 and in the vertical direction 30. Thus, the associated connecting section 46 also extends in the vertical direction 30.
[0105] As can be seen in particular from FIG. 12, the respective arm 38 in the exemplary embodiments shown in FIGS. 10 to 15 further comprises a tongue 47. The tongue 47 is arranged on the side of the associated support section 45 facing away from the rail 37, and thus on the side of the support section 45 facing away from the rail 37 in the vertical direction 30, and projects from the support section 45. The respective tongue 47 is shaped outwardly with respect to the associated outer wall 29. Thus, as indicated in particular in FIGS. 14 and 15, the electrical and mechanical connection between the arms 38 and the associated outer shells 7 can be established in a simple manner by sliding the outer shells 7 with the outer walls 29 between the associated arms 38. In this regard, as shown in FIGS. 14 and 15, after arranging the heating modules 3 in the heating device 1, the conductor arrangement 32 can be attached and electrically connected to the outer walls 7 by moving it relative to the heating modules 3 in the vertical direction 30 and in the longitudinal direction 4.
[0106] The exemplary embodiment shown in FIGS. 14 and 15 differs from the exemplary embodiment shown in FIGS. 10 to 13 in that the screw sections 41 of the conductor arrangement 32 are arranged on a rib 49 spaced from the control housing 9 and arranged in the heating volume 10 and are screwed thereto, wherein neither the control housing 9 nor the screws 40 are shown in FIGS. 14 and 15. In this exemplary embodiment, the rail 37 may lie flat against the bottom 14, and in particular may be clamped between the bottom 14 and a step 50 of the respective rib 49. In the exemplary embodiment shown, the steps 50 are connected to each other by a ledge 51 extending in the transverse direction 5. In this case, the rail 37 also rests on the ledge 51.
[0107] In principle, it is sufficient if the support sections 45 are mechanically loaded against the associated outer walls 29, as described. It is also conceivable to bond at least one of the support sections 45 to the associated outer wall 29 in an electrically conductive manner.
[0108] As can be seen, for example, from FIG. 4, the heating device 1 of the exemplary embodiments shown has an undulating corrugated rib 44 on the outer wall 29 of the respective outer shell 7 through which fluid can flow. Thus, a corrugated rib 44 is arranged between each of the facing outer walls 29 of the heating modules 3. In addition, in the exemplary embodiments shown, a corrugated rib 44 is also arranged in each case on the outermost outer walls 29 in the transverse direction 5. The respective corrugated rib 44 is connected to the at least one associated outer wall 29 in a heat-transferring manner. Preferably, the respective corrugated rib 44 is electrically conductive and mechanically connected to the respective associated outer wall 29. Thus, the respective corrugated rib 44 is also connected at the same electrical potential as the outer shells 7 and the control housing 9 and thus at equipotential.
[0109] The equipotential connection of the outer shells 7, the housing parts 11, 12 and, as the case may be, the corrugated ribs 44, makes it possible, in particular, to detect undesirable electrical currents and leaks within the heating device 1 easily and reliably, for example by connecting them to an electrical ground 33. Thus, the operational safety is increased. In addition, a disturbance of the power electronics is reduced. Furthermore, arranging the conductor arrangement 32 outside the control volume 13 and in the heating volume 10 leads avoids disturbances of the power electronics or at least reduces such disturbances.
