High-voltage power box for an electrically driven vehicle

Abstract

The invention relates to a high-voltage power box (1) for an electrically driven vehicle, having a housing (2) with components (12, 14), which are arranged therein, of a DC-to-DC converter and components (12, 14) of an onboard charger, wherein a liquid cooler (25) is arranged in the housing (2), having - a base (5) with an upper face (6) and a lower face (22) and - a cooling channel unit (7) which is arranged adjacently to the lower face (22) of the base (5) and which is made of a deep-drawn sheet metal, comprising an upper face (8) and a lower face, wherein the deep-drawn sheet metal of the cooling channel unit (7) and / or the base (5) is shaped such that cooling channels (9) are formed between the upper face (8) of the cooling channel unit (7) and the lower face (22) of the base (5), and components (12, 14) of the DC-to-DC converter and components (12, 14) of the onboard charger are arranged on the upper face (6) of the base (5) and on the lower face of the cooling channel unit (7).

Description

[0001] High-voltage box for an electrically powered vehicle

[0002] Description

[0003] The present invention relates to a high-voltage box for an electrically powered vehicle, comprising a housing with components of a DC-DC converter and components of an on-board charger arranged therein.

[0004] High-voltage boxes are installed in electrically powered vehicles. These boxes primarily contain a DC-DC converter for providing low voltage for the 12 V electrical system, as well as an on-board charger that charges the vehicle's high-voltage battery with mains voltage. These components are housed in a housing typically made of die-cast aluminum.

[0005] Since power components can exhibit high power losses during operation, effective cooling is required. A liquid cooler is often provided for this purpose. This can be located centrally within the housing, allowing both its top and bottom surfaces to be used for mounting power components. The liquid cooler is made of die-cast aluminum and exhibits very good thermal conductivity. A coolant, such as a water-glycol mixture, flows through it during operation.

[0006] The disadvantages of such a cooler are the relatively complex manufacturing process and the relatively large installation space, which is required, among other things, due to the required material thickness. This relatively high material thickness also results in a disadvantageously high weight.

[0007] It is therefore an object of the present invention to provide a high-voltage box for an electrically powered vehicle which is particularly compact, lightweight and cost-effective, while maintaining the same cooling performance, mechanical strength and integration capability (attachment, cooling connection) of the subsystems and individual components.

[0008] This problem is solved by the subject matter of the independent patent claim. Advantageous embodiments and further developments are the subject matter of the dependent claims.

[0009] According to one aspect of the invention, a high-voltage box for an electrically powered vehicle is specified, comprising a housing with components of a DC-DC converter and components of an on-board charger arranged therein. A liquid cooler is arranged in the housing, which has a base plate with a top side and a bottom side, and a cooling channel unit made of a deep-drawn sheet metal and having a top side and a bottom side, arranged adjacent to the bottom side of the base plate. Cooling channels are formed in the deep-drawn sheet metal between the top side of the cooling channel unit and the bottom side of the base plate. For this purpose, the deep-drawn sheet metal of the cooling channel unit and / or the base plate are shaped such that cooling channels are formed between the top side of the cooling channel unit and the bottom side of the base plate.For example, the cooling channels can be formed by recesses in the cooling channel unit introduced during deep drawing, with the base plate forming the missing wall of the cooling channels.

[0010] Components of the DC-DC converter and components of the on-board charger are arranged on the top side of the base plate and on the bottom side of the cooling channel unit.

[0011] The high-voltage box has the advantage that the liquid cooler can be significantly lighter and more compact than a die-cast liquid cooler due to the cooling channel unit being constructed from deep-drawn sheet metal. By arranging the components of the DC / DC converter and the on-board charger on both sides of the liquid cooler, its cooling capacity is optimally utilized. According to one embodiment, cavities made of sheet metal, in particular deep-drawn sheet metal, are arranged on the top side of the base plate and / or on the underside of the cooling channel unit. These cavities are designed to accommodate components of the DC / DC converter and components of the on-board charger, and in which the components are encapsulated with a potting compound.

[0012] In this embodiment, cavities for components such as PFC chokes and transformers are provided on the top side of the base plate and / or on the bottom side of the cooling channel unit. These cavities can also be made of deep-drawn sheet metal and are connected to the base plate or cooling channel unit, for example, by means of a brazing process or laser welding. These cavities accommodate the respective components and simultaneously form a housing for the subsequently applied potting compound. This enables optimal heat transfer to the coolant.

[0013] According to one embodiment, further components of the DC-DC converter and of the on-board charger are arranged on substrates which are arranged in the housing at a distance from the liquid cooler above and / or below the liquid cooler, in particular on opposite sides of the liquid cooler.

[0014] In this embodiment, several substrates with components arranged on them are stacked within the housing of the high-voltage box. While power components with their high power dissipation are in direct contact with the liquid cooler, other components, particularly control components, with lower cooling requirements, can be arranged at a greater distance from the liquid cooler. This arrangement, in particular, achieves a smaller footprint for the high-voltage box.

[0015] The substrates, arranged at a distance from the liquid cooler, are supported on the base plate and / or the cooling channel unit, for example, via bushings and / or bolts. It is particularly advantageous if the bushings or bolts are positioned such that they extend through the liquid cooler and jointly fix printed circuit boards above and below, in other words, on opposite sides of the liquid cooler in one position. This allows the number of required bushings or bolts to be kept to a minimum.

[0016] According to one embodiment, the base plate has a thickness D of 1.5 mm < D < 4 mm, and the cooling channel unit has a material thickness d of 0.5 mm < d < 2 mm. In particular, the thickness D can be approximately 3 mm and the thickness d 1.5 mm.

[0017] Such dimensions are easy to produce using common deep drawing processes and provide good heat transfer, and the relatively small thicknesses D, d allow weight savings to be achieved.

[0018] According to one embodiment, turbulators made of aluminum sheet are arranged in the cooling channels. These turbulators ensure a turbulent flow of the coolant through the cooling channels and thus particularly good heat dissipation. The turbulators can be arranged in particular in areas of the cooling channels where a particularly high heat input occurs due to the power components arranged therein.

[0019] The turbulators can, in particular, be structures made of strips of aluminum sheet metal that have been deep-drawn into a suitable shape, such as a waveform. They can be connected to the cooling channel unit and / or the base plate by a brazing process or laser welding.

[0020] According to one embodiment, it is provided that the housing of the high-voltage box has an upper housing part and a lower housing part, wherein the upper housing part is connected to the upper side of the base plate, wherein the base plate protrudes beyond the upper housing part at least in one connection area and a number of connections are arranged in the connection area on the base plate.

[0021] In this embodiment, the base plate protrudes beyond the housing top in the connection area, forming a connection plate on the base plate on which various connections can be arranged and are easily accessible. These can include, in particular, the input and output for the coolant, signal connections, and power connections of the DC-DC converter and / or the on-board charger.

[0022] This creates a uniform connection area with regard to electrical contact, sealing, and screwing of the connectors. The electrical contact can be made directly during the assembly process. The local concentration of the connections results in simplified assembly and reduced assembly costs. Another advantage is that the input and output filtering is also locally concentrated on the circuit board, simplifying EMC shielding.

[0023] The base plate and the cooling channel unit are connected to each other, primarily by a brazed joint. The upper and lower housing sections are each connected to the base plate by laser welding or clinching. This increases the rigidity of the structure, ensuring that the housing of the high-voltage box is sufficiently stable despite the liquid cooler being constructed from a sheet metal with reduced material thickness.

[0024] According to a further aspect of the invention, a method for manufacturing the described high-voltage box for an electrically powered vehicle is provided, wherein the connection of the base plate and the cooling channel unit with turbulators, cavities for receiving components, and bolts and / or bushings for supporting substrates on the liquid cooler takes place in a common joining process, for example by brazing. Embodiments of the invention are described below by way of example with reference to schematic drawings.

[0025] Figure 1 shows an exploded view of a high-voltage box according to an embodiment of the invention;

[0026] Figure 2 shows a plan view of the top of the high-voltage box according to Figure 1;

[0027] Figure 3 shows a sectional view of the high-voltage box according to Figures 1 and 2,

[0028] Figure 4 shows an exploded view of a part of the high-voltage box according to Figures 1 to 3,

[0029] Figure 5 shows a view of the liquid cooler for the high-voltage box according to Figures 1 to 4 and

[0030] Figure 6 shows another sectional view of the high-voltage box according to Figures 1 to 5.

[0031] The high-voltage box 1 shown in Figure 1 comprises a housing 2 with an upper housing part 3 and a lower housing part 4. Components 12, 14 of a DC-DC converter and an on-board charger are arranged in the housing 2. The components 12, 14 are arranged on several substrates 10, 11, 13, 15.

[0032] Components 12, 14 with increased cooling requirements are arranged directly adjacent to a liquid cooler 25 of the high-voltage box 1.

[0033] The liquid cooler 25 has a base plate 5 with a top side 6 and a bottom side not shown in the figure. It also has a cooling channel unit 7, which is formed as a deep-drawn sheet metal with cooling channels 9 in its top side 8. The cooling channel unit 7 is arranged with its top side 8 adjacent to the bottom side of the base plate 5, so that the cooling channels 9 are delimited by the cooling channel unit 7 and the base plate 5.

[0034] During operation, a coolant, in particular water, flows through the cooling channels 9 and absorbs the heat loss of the components 12, 14 arranged on the liquid cooler 25.

[0035] Substrates 11 and 15 are arranged at a distance from the liquid cooler 25 because the components arranged on them do not have increased cooling requirements. Substrates 15, 11 are supported on the liquid cooler 25 via bolts 16 and boxes 21.

[0036] Since both the cooling channel unit 7 and the base plate 5 are made of sheet metal, they have relatively thin material and thus a low weight. The liquid cooler 25 therefore also requires relatively little installation space.

[0037] Figure 2 shows a top view of the high-voltage box 1 and in particular the upper housing part 3, which is placed on the base plate 5. Figure 2 shows that the upper housing part 3 has a smaller dimension than the base plate 5, so that a connection plate 17 remains free on one side of the housing 2 on the base plate 5. The connections are located on the connection plate 17.

[0038] 18 of the high-voltage box 1, ie in particular the coolant inlet and outlet, signal connections and power connections for the on-board charger and the DC-DC converter.

[0039] Figure 3 shows a sectional view of the high-voltage box 1 with the stacked substrates 11, 12, 13 and 15. It can be seen that the substrates 12 and 13, which have the components requiring particular cooling, are arranged directly on the base plate 5 or on the cooling channel unit 7. Turbulators are provided in the cooling channels 9, at least in a central area where a particularly good heat transfer is to be achieved.

[0040] 19, which introduce turbulence into the coolant flow. The turbulators can be constructed, in particular, from wave-shaped, bent sheet metal strips.

[0041] Figure 4 shows an exploded view of the high-voltage box's liquid cooler 25. This view shows not only the base plate 5 and the cooling channel unit 7 with the turbulators 19, but also the coolant connections 18, i.e., the coolant inlet and outlet.

[0042] Furthermore, cavities 20 are shown, which can also be formed by deep-drawing from sheet metal and can be applied to the top side 6 of the base plate 5 and / or optionally also to the underside of the cooling channel unit 7 to accommodate components of the on-board charger or the DC-DC converter. In particular, they can accommodate transformers and PFC chokes of the on-board charger, which are subsequently encapsulated with a potting compound. The cavities 20 serve as a mold for the potting compound and simultaneously ensure particularly good heat transfer to the liquid cooler 25.

[0043] Figure 5 shows a view of the liquid cooler 5 with the base plate 5 and the cooling channel unit 7, each formed from deep-drawn sheet metal. The cooling channel unit 7 is arranged on the underside 22 of the base plate 5 and, in the embodiment shown, has a smaller dimension than the base plate 5. The cooling channels 9 are formed in the cooling channel unit 7, with the turbulators 19 in the central region of the cooling channel unit 7. Furthermore, Figure 5 shows the inlet 23 and the outlet 24 for the coolant.

[0044] The cooling channel unit 7 is connected to the base plate 5 by a brazing process. Brazing can be carried out in particular in a brazing furnace. In this case, the turbulators 19 can also be brazed to the cooling channel unit 7 and / or the base plate 5. In addition, areas of the inlet 23 and the outlet 24 can be brazed to the base plate 5. Figure 6 shows a sectional view of the high-voltage box 1, in which the connection plateau

[0045] 17 with the connections 18 can be seen. The connection plate 17 is formed by the housing upper part 3 being less extensive than the base plate 5 and resting on the upper side 6 of the base plate 5 in an area A, where it is connected to the base plate by laser welding. Thus, the upper side 6 of the base plate 5 is exposed in the area of ​​the connection plate 17.

Claims

Patent claims 1. High-voltage box (1) for an electrically powered vehicle, comprising a housing (2) with components (12, 14) of a DC-DC converter and components (12, 14) of an on-board charger arranged therein; wherein a liquid cooler (25) is arranged in the housing (2), comprising - a base plate (5) with a top side (6) and a bottom side (22) and - a cooling channel unit (7) arranged adjacent to the underside (22) of the base plate (5) and made of a deep-drawn sheet metal with an upper side (8) and a lower side, wherein the deep-drawn sheet metal of the cooling channel unit (7) and / or the base plate (5) are shaped such that cooling channels (9) are formed between the upper side (8) of the cooling channel unit (7) and the underside (22) of the base plate (5), and wherein components (12, 14) of the DC-DC converter and components (12, 14) of the on-board charger are arranged on the upper side (6) of the base plate (5) and on the underside of the cooling channel unit (7).

2. High-voltage box (1) according to claim 1, wherein on the upper side (6) of the base plate (5) and / or on the underside of the cooling channel unit (7) cavities (20) made of sheet metal are arranged, which are designed to receive components (12, 14) of the DC-DC converter and components (12, 14) of the on-board charger, and in which the components (12, 14) are cast with a casting compound.

3. High-voltage box (1) according to claim 1 or 2, wherein further components (12, 14) of the DC-DC converter and of the on-board charger are arranged on substrates (11, 15) which are arranged at a distance from the liquid cooler (25) above and / or below the liquid cooler (25) in the housing (2).

4. High-voltage box (1) according to claim 3, wherein the substrates (11, 15) are supported on the base plate (5) and / or the cooling channel unit (7) via bushings (21) and / or bolts (16).

5. High-voltage box according to claim 4, wherein bushings and / or bolts (16) are positioned such that they extend through the liquid cooler (25) and fix substrates (11, 15) below and above the liquid cooler (25) together in one position.

6. High-voltage box (1) according to one of claims 1 to 5, wherein the base plate (5) has a thickness D with 1.5 mm < D < 4 mm and the cooling channel unit (7) has a material thickness d with 0.5 mm < d < 2 mm.

7. High-voltage box (1) according to one of claims 1 to 6, wherein turbulators (19) made of aluminum sheet are arranged in the cooling channels (9).

8. High-voltage box (1) according to one of claims 1 to 7, wherein the housing (2) has an upper housing part (3) and a lower housing part (4), wherein the upper housing part (3) is connected to the upper side (6) of the base plate (5), wherein the base plate (5) projects beyond the upper housing part (3) at least in one connection area and a number of connections (18) are arranged on the base plate (5) in the connection area.

9. High-voltage box (1) according to one of claims 1 to 8, wherein the base plate (5) and the cooling channel unit (7) are connected to one another by a brazing connection or laser welding connection.

10. High-voltage box (1) according to claim 8 or 9, wherein the housing upper part (3) and the housing lower part (4) are each connected to the base plate (5) by a laser welding connection or by clinching.

11. A method for producing a high-voltage box for an electrically powered vehicle according to one of claims 1 to 10, wherein the connection of the base plate and the cooling channel unit with turbulators, cavities for receiving components and bolts and / or bushings for supporting substrates on the liquid cooler takes place in a common connection process.

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