Electric heating device

Abstract

The invention relates to an electric heating device (2) for heating a liquid medium, comprising a first heating chamber (6.1) and a second heating chamber (6.2), and an electric heating assembly (22), which is arranged between the first heating chamber (6.1) and the second heating chamber (6.2) and is coupled to the first heating chamber (6.1) and the second heating chamber (6.2) in a thermally conductive manner. In order to provide an electric heating device which can be easily adapted to different heating powers and / or operating voltages, the first heating chamber (6.1) has a first channel section (84, 86) and the second heating chamber (6.2) has a second channel section (88, 90). The first and / or second channel section (84, 88; 86, 90) in the two heating chambers (6.1; according to the invention, a flow connection (AS, ES) is formed between the flow channels (6.1, 6.2), which flow connection passes through the plane (E) comprising the electric heating element (22) and the length of which can be varied in the transverse direction of the plane (E) comprising the electric heating element (22).

Description

Technical Field

[0001] The present invention relates to an electric heating device for heating a liquid medium, the electric heating device comprises a first heating chamber, a second heating chamber and an electric heating component, the electric heating component is arranged between the first heating chamber and the second heating chamber and coupled to the first heating chamber and the second heating chamber in a heat-conducting manner. Background Art

[0002] This electric heating device is known from EP 2 559 573 A1. In this prior art, the electric heating assembly is located between two heating chambers, which are formed by different housing parts and also accommodate the electric heating device between them. On the one hand, the connection between the different housing parts must be fluid-tight, so as to seal at least one of the heating chambers in the heating chamber. However, on the other hand, the layers of the electric heating assembly with PTC elements and contact sheets on both sides must reliably abut each other, so as to achieve good electrical contact and good heat extraction. In the above-mentioned prior art, a heating chamber in the heating chamber is covered by a control housing, and the control housing accommodates a power transistor that is removed from the heat via the corresponding heating chamber. The control housing is suitable as a separate, self-contained or independent (self-contained) component, and forms the cover of the corresponding heating chamber. The medium to be heated travels through a heating chamber in the heating chamber, and then passes through another heating chamber in the heating chamber, parallel to the layers of the electric heating assembly. Summary of the invention

[0003] The present invention aims to provide an electric heating device which can be easily adapted to different heating powers and / or operating voltages.

[0004] In view of this, the present invention provides an electric heating device, wherein the first heating chamber includes a first channel section, and the second heating chamber includes a second channel section. The first channel section or the second channel section forms a flow connection between the two heating chambers, and the flow connection passes through the plane including the electric heating component. Since the first channel section and the second channel section can also overlap, the two channel sections can also be combined to form a flow connection between the two heating chambers, and the flow connection passes through the plane including the electric heating component. According to the present invention, the length of the flow connection can be changed in the lateral direction of the plane including the electric heating component. For this purpose, the corresponding channel sections can be changed in length individually or as a whole.

[0005] The channel sections can be connected to each other in a telescopic manner so that the length of the flow connection can be varied. Additionally or alternatively, a bellows can be arranged between each channel section assigned to each heating chamber. The variable length will allow the two heating chambers to be arranged at a variable distance in order to compensate for a certain degree of tolerance resulting from each layer of the electric heating assembly, in particular a certain degree of tolerance resulting from a layer defined by a plurality of PTC elements.

[0006] With regard to the solution having the required stability under operating conditions of a motor vehicle, in particular in the case of a motor vehicle using an electric heating device according to the invention, it is proposed according to a preferred further development of the invention that the first channel section has a bushing end and that the second channel section has a tip end which projects into the bushing end. A sealing arrangement is provided between the bushing end and the tip end, which sealing arrangement can be displaced in at least one of the tip end and the bushing end. Thus, this further development proposes a rigid construction of the channel section itself, wherein the variation in length of the flow connection is achieved by a sealing arrangement which is displaced relative to at least one of the tip end and the bushing end.

[0007] The variation in length of the flow channel allows a heating device of different thicknesses to be arranged between the first heater and the second heating chamber. These different thicknesses may be required by different configuration parameters, such as the heating power that the electric heating device is intended to provide when the model is modified. The electric heating assembly of the electric heating device according to the present invention preferably includes a PTC element, the thickness of which should vary with the applied operating voltage to prevent electrical flashover. Therefore, since the flow connection can vary in length, PTC elements of different thicknesses can be placed between the first heating chamber and the second heating chamber, thereby providing an electric heating device for operating at 400 volts or an electric heating device for operating at 800 volts. In the latter case, all PTC elements between the two heating chambers are thicker than in the first case mentioned.

[0008] For example, the electric heating device according to the invention can be adapted as desired, without having to change the structure, such as in the case of a model modification for operation at a different operating voltage.

[0009] Preferably, an abutment shoulder is assigned to the distal end, said abutment shoulder interacting axially and / or radially with the sealing arrangement. The sealing arrangement may comprise one or more sealing rings, by means of which the sealing arrangement can be precisely positioned at least with respect to the axial position relative to the distal end.

[0010] Preferably, the housing, in particular the housing base part described in more detail below, is connected to the inlet nozzle and the outlet nozzle. These nozzles can be screwed, riveted, welded, brazed or bonded to the housing base part, which is formed as a casting or deep-drawn part, or connected in some other way to form a part. The nozzles are used to connect the electric heating device to a hose or pipe in the interior of the vehicle that carries the medium to be heated.

[0011] Preferably, the housing (particularly the housing base portion described in more detail below) forms a first inlet channel section connected to the inlet nozzle and / or a first outlet channel section connected to the outlet nozzle. Preferably, the fluid housing forms a second inlet channel section aligned with the first inlet channel section and / or a second outlet channel section aligned with the first outlet channel section. The first inlet channel section and the first outlet channel section are assigned to the first heating chamber. The second inlet channel section and the second outlet channel section are assigned to the second heating chamber. The converging inlet channel section or the outlet channel section allows the diversion introduced into the fluid housing to be transmitted with low pressure loss. The nozzle can be aligned with the channel section. Typically, the nozzle and the channel section provide a medium flow at right angles to the layers of the electric heating device.

[0012] The second inlet channel section and / or the first outlet channel section are usually arranged downstream of the distributor in the flow direction. The distributor is usually formed by the housing base part. The distributor divides the medium introduced through the inlet into a flow to the first heating chamber and the second heating chamber, and / or the flow from the first heating chamber and the second heating chamber is merged together through the distributor. The distributor is usually located on one side of the fluid housing or one side of the heating device.

[0013] In this preferred arrangement, the inlet channel segment forms an inlet flow connection through a plane comprising the electric heating assembly.Preferably, a corresponding outlet flow connection through a plane comprising the electric heating assembly is formed by the outlet channel segment.

[0014] The housing is formed by a housing base part and a housing cover, preferably only by the housing base part and the housing cover. The housing base part has a housing bottom, which is usually flat and delimits the housing, and the housing bottom usually extends substantially parallel to the housing cover. These parts of the housing are usually made of a metal material; in any case, the material has good electromagnetic shielding properties. In the case where the shielding device is incorporated into the housing or surrounds the housing or shields the housing (for example, formed by a wire mesh), a housing made of plastic is also feasible. Preferably, the accommodation space formed by the housing for accommodating all the components of the electric heating device is limited by only two components (the housing base part and the housing cover). BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Other details and advantages of the present invention will become apparent from the following description of the embodiments in conjunction with the accompanying drawings. In the accompanying drawings:

[0016] Figure 1 : An exploded perspective view of an embodiment of the present invention;

[0017] Figure 2 :according to Figure 1 An exploded perspective view of a housing base portion and a heating chamber cover of an embodiment of the present invention;

[0018] Figure 3 :according to Figure 1 An exploded perspective view of a fluid housing of an embodiment of the present invention;

[0019] Figure 4 :according to Figure 1 A top perspective view of a housing base portion partially equipped with components of an embodiment of the present invention; and

[0020] Figure 5 :along Figure 4 A cross-sectional view of the first embodiment is drawn along line VV in FIG. DETAILED DESCRIPTION

[0021] Figure 1 An electric heating device 2 is shown with a housing base part 4, which is provided at Figure 1 The lower side of the heating chamber is connected to the heating chamber cover 8 to form the first heating chamber 6.1 (see Figure 2 ). Reference numeral 10 denotes a fluid housing, which is accommodated in an accommodating space 12 formed by a housing base portion 4. The lower side of the accommodating space 12 is defined by a bottom 14, and the peripheral side is defined by a peripheral wall 16 extending from the bottom 14. In the accommodating space 12 and between the bottom 14 and the fluid housing 10, there is a first insulating layer 18 that can abut against the bottom 14, a first contact layer 20, a heating assembly 22 having a plurality of heating elements 23 (in the form of PTC elements 24 in this example), and a positioning frame 26 having an accommodating portion 28 for accommodating the PTC elements 24.

[0022] A second contact layer 30 is provided on the side of the heating component 22 opposite to the first contact layer 20, and a second insulating layer 32 is arranged on the side of the second contact layer 30 opposite to the heating component 22. Therefore, the PTC element is applied with conductivity against the contact layers 20, 30, and is energized via the contact layers 20, 30. The PTC element 24 is a ceramic cuboid component, and the PTC element 24 is provided with a metallization on the opposite main side surface for current conduction. The main side surface is the surface of the cuboid with the largest surface area. The main side surfaces are connected to each other by the peripheral surface, which defines the height of the PTC element and has no metallization. Each main side surface is approximately 5 times larger than one of the peripheral surfaces, preferably larger than the sum of all peripheral surfaces.

[0023] The second insulating layer 32 is formed into a biasing device 33 by a silicone film, and the silicone film can absorb a certain compression through elastic deformation, thereby arranging the electric heating component 22 between the shell base part 10 and the shell bottom 14, and biasing the electric heating component 22 against the shell base part 10 and the shell bottom 14.

[0024] The layering of the first insulating layer 18 , the first contact layer 20 , the heating device 21 , the second contact layer 30 and the second insulating layer 32 is also referred to below as a layered structure 34 .

[0025] In the embodiment shown, on the side of the fluid housing 10 facing away from the layered structure 34, a transistor insulator 40 is located between a printed circuit board 38 forming the control device 36 and the fluid housing 10. Reference numeral 42 denotes a housing cover which is connected to the housing base part 4 to form a Figure 5 The housing is denoted by reference numeral 44 in FIG. The housing base part 4 and the housing cover 42 (and possibly other housing parts) are configured to be shielded (i.e., made of metal), and / or separate shields are provided in the interior, exterior or walls of the individual housing parts (the individual housing parts can be conceivably made of plastic). The preferred metal material is aluminum, or, in view of corrosion resistance, the preferred metal material is stainless steel.

[0026] The power connector 46 and the control connector 48 are Figure 1 4 is shown as being located at the lower side of the housing base part 4 opposite the housing cover 42. The two connectors 46, 48 are connected to the housing base part 4 in a sealed manner and have various male electrical plug contacts, which pass through the respective housings of the connectors 46, 48 in a sealed manner and make plug contacts in the printed circuit board 38 and are electrically connected to the strip conductors of the printed circuit board 38 via the plug contacts. Figure 4For the plug-in contact, the printed circuit board 38 has a female contact tongue receptacle as described in EP 2 236 330 A1.

[0027] Furthermore, an inlet nozzle 50 and an outlet nozzle 52 are provided on the lower side for connecting a pipe or a hose carrying the fluid to be heated. Figure 1 , which is formed by two sealing rings 54, which are explained in more detail below. Reference numeral 56 denotes a screw, which is used to fix the fluid housing 10 relative to the housing base part 4 with the layered structure 34 inserted. By means of this screw connection, the layers of the layered structure 34 are biased against the fluid housing 10 and the bottom 14 of the housing base part 4.

[0028] Figure 2 An exploded view of a housing base part 4 and a heating chamber cover 8 is shown, the heating chamber cover 8 being shown separated from the housing base part 4 and showing the interior of the first heating chamber 6.1. It can be seen that the nozzles 50, 52 are formed by separate parts which are aligned with two holes in the heating chamber cover 8 formed by a flat metal sheet or metal plate, one of which forms the inlet 58 and the other forms the outlet 60. The nozzles 50, 52 may be welded or bonded to the heating chamber cover 8.

[0029] Reference numeral 62 denotes a distributor arranged in a plane HE including the first heating chamber 6.1. The distributor 62 has an inlet distributor section 64 and an outlet distributor section 66, which are arranged to be separated from each other and covered by the heating chamber cover 8. Each distributor section 64, 66 is arranged to be symmetrical with respect to the longitudinal axis L of the housing base part 4, and is associated with an inlet branch 68 and an outlet branch 70 of the first heating chamber 6.1, respectively. In a top view, the distributor sections 64, 66 each have a ground area that is approximately triangular. Each distributor section 64, 66 merges into each corresponding branch 68, 70 via an overflow edge 72. The overflow edge 72 is located between the first heating chamber bottom 74 of the first heating chamber 6.1 and the opposite cover surface of the first heating chamber 6.1 in the height direction, and the cover surface is formed by the heating chamber cover 8.

[0030] A flow guiding rib 76 protrudes from the first heating chamber bottom 74 to guide the fluid, and the heating chamber cover 8 abuts against the flow guiding rib 76 in a fluid-tight manner.

[0031] In each case, the inlet 58 or outlet 60 is arranged such that it partially covers the first heating chamber 6 . 1 and partially covers the respective distributor section 64 , 66 . The overflow edge 72 passes approximately centrally through the hole forming the inlet 58 or outlet 60 .

[0032] exist Figure 3 Details of the second heating chamber 6.2 can be seen in FIG. The fluid housing 10 is formed by a fluid housing base part 78 and a fluid housing cover 80, which is welded to the fluid housing base part 78. The second heating chamber 6.2 also comprises a flow guide rib 76. A plurality of fastening eyelets 82 are provided on the periphery of the fluid housing 10, through which screws 56 are guided in order to connect the fluid housing 10 to the housing bottom 14 with the electric heating assembly 22 inserted. Figure 4 , the thread formed on the housing bottom 14 is indicated by reference numeral 83 .

[0033] exist Figure 4 In the embodiment of the present invention, reference numeral 84 denotes a first inlet channel section, and reference numeral 86 denotes a first outlet channel section. These channel sections 84, 86 are formed on the housing base part 4 and pass through the housing base part 4. Figure 3 A second inlet passage section 88 and a second outlet passage section 90 are shown integrally formed on the fluid housing base portion 78 .

[0034] Especially by Figure 5 As conveyed, the second channel sections 88, 90 are formed as tip ends 92, each of which engages a bushing end 94 formed by the first channel sections 84, 86, wherein a sealing arrangement 53 is disposed between the tip ends 92 and the bushing ends 94 and abuts against an abutment shoulder 96 disposed on the corresponding tip end 92 in the axial direction and the radial direction.

[0035] The tip end 92 and the bushing end 94 have an axial length such that electric heating assemblies 22 having different thicknesses can be arranged between the fluid housing 10 and the housing bottom 14 without losing the seal between the housing base portion 4 and the fluid housing 10. Thus, the inlet flow connection ES formed by the inlet channel sections 84, 86 is variable in length transversely or perpendicularly to the plane E including the electric heating assembly 22. The same applies to the outlet flow connection denoted by reference numeral AS.

[0036] The fluid flow introduced into the electric heating device 2 via the inlet 58 is divided into two partial flows in the region of the distributor 62. The first partial flow T1 flows into the first heating chamber 6.1 via the overflow edge 72, while the second partial flow T2 runs through the inlet flow connection ES, flows through the second heating chamber 6.2, first through the inlet branch 68, and then through the outlet branch 70, and finally through the outlet flow connection AS, merges with the first partial flow T1 in the region of the distributor 62, and the fluid flow resulting from the combination of the two partial flows T1, T2 is discharged through the outlet.

[0037] Figure 4 The electrical connection concept of the printed circuit board 38 is also conveyed. The contact tongues 202 of the male plug contacts 204 are exposed at the free end of the connector (only the power connector 46 is shown), or at the free end of the terminal lugs 206 of the negative contact, or at the free end of the terminal lugs 208 of the positive contact, which contact tongues 202 protrude into the mounting plane of the printed circuit board 38, which can be identified by the support 200 for the printed circuit board 38. The terminal lugs 206, 208 also protrude beyond the fluid housing 10 after assembly, which is arranged below the mounting plane of the printed circuit board 38. By simply lowering the printed circuit board 38 in the direction of the housing bottom 14 (i.e. in a direction orthogonal to the plane extension of the housing bottom 14), the printed circuit board 38 can be plugged into contact with all the contact tongues 202. The mounted printed circuit board 38 rests on the support 200 and is fixed against the housing base part 4 by means of screws (not shown) which engage in threads of the support 200 .

[0038] The solution described in this article provides the following advantages:

[0039] 1. Since the electric heating assembly 22 is disposed in the metal housing 44, good EMC shielding is achieved.

[0040] 2. Since the heating chambers 6.1; 6.2 are arranged on each side of the electric heating component 22, the heat is dissipated to the medium to be heated on the two main sides of the electric heating component 22.

[0041] 3. Since the medium to be heated is divided into the streams T1 and T2, the same heating conditions are present on both sides of the electric heating assembly 22. This also applies to the corresponding branches 68 and 70. Therefore, the PTC elements 24 distributed relative to the housing bottom 14 are each located between the heat dissipation surfaces provided by the first heating chamber 6.1 or the second heating chamber 6.2, which apply the same temperature gradient to the corresponding PTC elements 24.

[0042] 4. All housing parts are made of aluminum or aluminum alloy, thus saving weight.

[0043] 5. All housing parts 4, 20; 78, 80 delimiting the respective heating chamber 6.1, 6.2 are welded together directly and in a fluid-tight manner, thereby achieving a high degree of reliability with regard to the seal.

[0044] 6. Furthermore, after the housing parts 4, 20; 78, 80 are combined to form the heating chamber 6.1; 6.2, and before the electric heating device 2 is finally assembled, the sealing of the heating chamber 6.1; 6.2 can be tested.

[0045] 7. Since the flow connections ES and AS for the inlet or outlet of the medium can vary in length, electric heating components 22 of different thicknesses and therefore different performances can be installed without having to change the shell parts 4, 20; 78, 80 that define the first heating chamber 6.1 or the second heating chamber 6.2.

[0046] 8. The distributor 62 enables the division of the same partial flows T1 , T2 with the same volume flow rate with low pressure difference losses.

[0047] 9. The inlet nozzle 50 and outlet nozzle 52 are connected to the housing base part 4 as separate components so that these interfaces can be adapted to connect pipes or pipelines according to customer requirements without having to change the components defining the first heating chamber 6.1 or the second heating chamber 6.2.

[0048] Reference numerals list

[0049] 2 Electric heating device

[0050] 4 Shell base part

[0051] 6.1 The first heating chamber

[0052] 6.2 Second Heating Chamber

[0053] 8 Heating chamber cover

[0054] 10Fluid housing

[0055] 12Accommodation space

[0056] 14 Shell bottom

[0057] 16 Peripheral wall

[0058] 18 first insulating layer

[0059] 20 First contact layer

[0060] 22 Heating components

[0061] 23 Heating elements

[0062] 24PTC components

[0063] 26 Positioning frame

[0064] 28 Accommodation

[0065] 30 Second contact layer

[0066] 32 Second insulation layer

[0067] 33 Bias device

[0068] 34 Layered Structure

[0069] 36 Control Devices

[0070] 38 PCB

[0071] 40 transistor insulation

[0072] 42 Shell cover

[0073] 44 Shell

[0074] 46 Power Connector

[0075] 48 control connector

[0076] 50 Inlet Nozzle

[0077] 52 outlet nozzle

[0078] 53 Sealing arrangement

[0079] 54 Sealing ring

[0080] 56 screws

[0081] 58 Entrance

[0082] Exit 60

[0083] 62 Distributor

[0084] 64 inlet distributor section

[0085] 66 outlet distributor section

[0086] 68 entrance branch

[0087] 70 exit branch

[0088] 72 Overflow Edge

[0089] 74 Bottom of the first heating chamber

[0090] 76 guide ribs

[0091] 78 Fluid housing base part

[0092] 80 fluid housing cover

[0093] 82 fastening holes

[0094] 83 thread

[0095] 84 First entrance channel section

[0096] 86 First outlet channel section

[0097] 88 Second entrance channel section

[0098] 90 Second exit channel section

[0099] 92 distal end

[0100] 94 Bushing end

[0101] 96 abutment shoulder

[0102] 200 Support

[0103] 202 tongue contact

[0104] 204 Male plug contact

[0105] 206 Terminal lug for negative contact

[0106] 208 Terminal lug for positive contact

[0107] AS outlet flow connection

[0108] ES inlet flow connection

[0109] E includes the plane of the electric heating component

[0110] HE includes a plane of the first heating chamber

[0111] L Longitudinal axis

[0112] T1 first shunt

[0113] T2 Secondary Shunt

Claims

1. An electric heating device (2) for heating a liquid medium, the electric heating device comprising a first heating chamber (6.1) and a second heating chamber (6.2) and an electric heating component (22), the electric heating component being arranged between the first heating chamber (6.1) and the second heating chamber (6.2), and the electric heating component being coupled to the first heating chamber (6.1) and the second heating chamber (6.2) in a heat-conducting manner, It is characterized in that The first heating chamber (6.1) has a first channel section (84, 86), and the second heating chamber (6.2) has a second channel section (88, 90), wherein the first channel section and / or the second channel section (84, 88; 86, 90) form a flow connection (AS, ES) between the two heating chambers (6.1; 6.2), the flow connection passes through a plane (E) including the electric heating component (22), and the length of the flow connection can be varied in a transverse direction of the plane (E) including the electric heating component (22).

2. The electric heating device (2) according to claim 1, characterized in that: The first channel section (84, 86) has a bushing end (94), wherein the second channel section (88, 90) has a tip end (94) extending into the bushing end (94), and wherein a sealing arrangement (53) is provided between the bushing end (94) and the tip end (92), the sealing arrangement being capable of shifting toward at least one of the tip end (92) and the bushing end (96).

3. The electric heating device (2) according to claim 2, characterized in that: An abutment shoulder (96) which interacts axially and / or radially with the sealing arrangement (53) is assigned to the distal end (92).

4. The electric heating device (2) according to claim 1, characterized in that: A first inlet channel section (84) and a first outlet channel section (86) are assigned to the first heating chamber (6.1), wherein a second inlet channel section (88) and a second outlet channel section (90) are assigned to the second heating chamber (6.1), wherein the first inlet channel section (86) and the second inlet channel section (88) form an inlet flow connection (ES) between the two heating chambers (6.1; 6.2), the inlet flow connection passing through the plane (E) including the electric heating component (22), and the The length of the inlet flow connection portion is capable of varying in the transverse direction of the plane (E) including the electric heating component (22), and wherein the first outlet channel section (86) and the second outlet channel section (90) form an outlet flow connection portion (AS) between the two heating chambers (6.1; 6.2), the outlet flow connection portion passes through the plane (E) including the electric heating component (22), and the length of the outlet flow connection portion is capable of varying in the transverse direction of the plane (E) including the electric heating component (22).

5. The electric heating device (2) according to claim 1, characterized in that: The first heating chamber (6.1) is formed between a housing bottom (14) of a housing base part (4) forming an inlet (58) and an outlet (60) for the medium and a heating chamber cover (8), and wherein the second heating chamber (6.2) is formed by a fluid housing (10) arranged inside the housing base part (4).

6. The electric heating device (2) according to claim 5, characterized in that: The housing base part (4) forms a distributor (62), by means of which the medium introduced through the inlet (58) is divided into partial flows (T1; T2) flowing to the first heating chamber (6.1) and the second heating chamber (6.2), and the partial flows (T1; T2) from the first heating chamber (6.1) and the second heating chamber (6.2) are merged together.

7. The electric heating device (2) according to claim 1, characterized in that: The housing (44) forms an inlet (58) and an outlet (60) for the medium and forms a receiving space (12) defined by the housing base part (4) and the housing cover (42), wherein the heating assembly (22) and the fluid housing (10) forming the second heating chamber (6.2) are accommodated in the housing.

8. The electric heating device (2) according to claim 7, characterized in that: The first heating chamber (6.1) is formed between a housing bottom (14) of the housing base part (4) and a heating chamber cover (8) connected to the housing base part in a fluid-tight manner, and wherein the second heating chamber (6.2) is formed by a fluid housing (10) accommodated in the housing (44).

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