BDU structure with balanced heat dissipation

Abstract

The utility model provides a BDU structure with balanced heat dissipation, and belongs to the technical field of BDUs. Comprising an upper shell; the side, close to the upper shell, of the bottom shell and the upper shell define a first cavity, and the side, away from the upper shell, of the bottom shell is provided with a second cavity. The load loop is used for transferring energy of the battery module to the load motor, and the load loop is arranged in the first cavity and extends towards the direction of the second cavity; the charging loop is used for transferring energy of the charging gun to the battery module, and the charging loop is arranged in the first cavity and extends towards the direction of the second cavity; the high-voltage wiring harness unit is used for acquiring a high-voltage sampling signal when the load loop or the charging loop works; the low-voltage wire harness unit is used for acquiring a low-voltage sampling signal when the load loop or the charging loop works; the distance between the sampling end of the high-voltage wire harness unit and the bottom shell is not completely the same as the distance between the sampling end of the low-voltage wire harness unit and the bottom shell. And an integrated heat dissipation unit is arranged in the second cavity.

Description

Technical Field

[0001] The utility model relates to the technical field of battery cut-off units, in particular to a BDU structure with balanced heat dissipation. Background Art

[0002] The BDU, namely the Battery Disconnect Unit, is an important component between new energy power batteries and input / output circuits, mainly used for high-voltage distribution, short-circuit protection, etc., to form reliable output protection for the battery pack. With the continuous improvement of the energy density of new energy vehicles, in order to meet the requirements of long endurance and fast charging, both the battery pack capacity and the charging voltage are continuously increased. Parts such as wiring harnesses and connectors in some high-voltage circuits are designed, developed, and verified according to the 800V requirement. When quickly charging or releasing energy, the instantaneous power is extremely large, generating a large amount of heat. This poses a great challenge to the heat dissipation structure of the BDU. The Chinese utility model patent CN214477640U discloses a BDU for a battery pack high-voltage distribution box, in which a plurality of electrical components are arranged in the lower shell body. A plurality of electrical component brackets can be connected through copper bars and wiring harnesses to form a positive electrode circuit, a negative electrode circuit, and a pre-charge circuit. The ground surface of the copper bar extends beyond the bottom surface of the lower shell body. An insulating film is arranged on the copper bar and the bottom surface of the lower shell body, and a heat conduction pad is arranged on the insulating film. The heat conduction pad is used independently and can only dissipate heat for the adjacent copper bars. The heat dissipation effect is relatively limited when the heat generation is large.

[0003] Therefore, it is very necessary to provide a BDU structure with balanced heat dissipation to improve the deficiencies of the existing heat dissipation pads, such as a large number and independent operation respectively, resulting in low heat dissipation efficiency. Summary of the Utility Model

[0004] In view of this, the utility model proposes a BDU structure with an integrated heat dissipation structure of a larger area, which can achieve balanced heat dissipation of the pads in both discharge and charging modes.

[0005] The technical solution of the utility model is realized as follows: The utility model provides a BDU structure with balanced heat dissipation, including:

[0006] An upper shell;

[0007] A bottom shell, the side close to the upper shell encloses a first cavity with the upper shell, and the side far from the upper shell has a second cavity;

[0008] A load circuit, arranged in the first cavity and extending towards the direction of the second cavity;

[0009] A charging circuit, arranged in the first cavity and extending towards the direction of the second cavity;

[0010] A high-voltage wiring harness unit, arranged in the first cavity;

[0011] A low-voltage wiring harness unit, disposed in the first cavity;

[0012] Wherein, the distance between the sampling end of the high-voltage wiring harness unit and the bottom case is not exactly the same as the distance between the sampling end of the low-voltage wiring harness unit and the bottom case; an integrated heat dissipation unit is disposed in the second cavity, and the integrated heat dissipation unit is adapted to the height of the second cavity.

[0013] Based on the above technical solutions, preferably, the load circuit includes a discharge main positive relay, a discharge main negative relay, a battery pack positive copper bar, a main fuse, a first copper bar, a discharge main positive copper bar, a discharge main negative copper bar, a second copper bar, a shunt, and a battery pack negative copper bar; one end of the battery pack positive copper bar is electrically connected to the positive electrode of the battery module, the other end of the battery pack positive copper bar is electrically connected to one end of the main fuse, the other end of the main fuse is electrically connected to one end of the first copper bar, the other end of the first copper bar is electrically connected to the first terminal of the discharge main positive relay, one end of the discharge main positive copper bar is electrically connected to the second terminal of the discharge main positive relay, and the other end of the discharge main positive copper bar is electrically connected to the positive electrode of the load motor; the negative electrode of the load motor is electrically connected to one end of the discharge main negative copper bar, the other end of the discharge main negative copper bar is electrically connected to the first terminal of the discharge main negative relay, one end of the second copper bar is electrically connected to the second terminal of the discharge main negative relay, the other end of the second copper bar is electrically connected to one end of the shunt, the other end of the shunt is electrically connected to one end of the battery pack negative copper bar, and the other end of the battery pack negative copper bar is electrically connected to the negative electrode of the battery module.

[0014] Preferably, the charging circuit includes a fast charging main positive relay, a fast charging main negative relay, a fast charging positive copper bar, and a fast charging negative copper bar; one end of the fast charging positive copper bar is electrically connected to the positive electrode of the charging gun, the other end of the fast charging positive copper bar is electrically connected to the first terminal of the fast charging main positive relay, and the second terminal of the fast charging main positive relay is also electrically connected to a non-end position of the first copper bar; the first terminal of the fast charging main negative relay is also electrically connected to the second copper bar, the second terminal of the fast charging main negative relay is electrically connected to one end of the fast charging negative copper bar, and the other end of the fast charging negative copper bar is electrically connected to the negative electrode of the charging gun; a plurality of through first slots are provided on the base, and the first slots communicate the first cavity and the second cavity with each other; the battery pack positive copper bar, the first copper bar, the discharge main positive copper bar, the discharge main negative copper bar, the second copper bar, the shunt, the battery pack negative copper bar, the fast charging positive copper bar, and the fast charging negative copper bar are fixedly arranged in one-to-one correspondence with the plurality of first slots.

[0015] More preferably, the end faces of the battery pack positive copper bar, the first copper bar, the discharge main positive copper bar, the discharge main negative copper bar, the second copper bar, the battery pack negative copper bar, the fast charging positive copper bar, and the fast charging negative copper bar passing through the first slot and extending into the second cavity are all located in the same reference plane.

[0016] More preferably, a plurality of second card slots are provided on the bottom case; partition ribs are provided on one side of the main discharge positive relay, the main discharge negative relay, the fast charge main positive relay, and the fast charge main negative relay close to the bottom case; one end of the partition rib is fixedly connected to the surface of the main discharge positive relay, the main discharge negative relay, the fast charge main positive relay, and the fast charge main negative relay close to the bottom case, and the other end of the partition rib passes through the second card slot and extends towards the second cavity; the distance that the partition rib extends into the second cavity does not exceed the reference plane.

[0017] Preferably, the integrated heat dissipation unit includes an insulating film, a heat conductive pad, and an integrated heat dissipation block; a plurality of embedded grooves are provided on one side of the insulating film close to the bottom case, and the inner surfaces of the plurality of embedded grooves are fitted with the end faces of the battery pack positive copper row, the first copper row, the main discharge positive copper row, the main discharge negative copper row, the second copper row, the battery pack negative copper row, the fast charge positive copper row, and the fast charge negative copper row passing through the first card slot and extending into the second cavity; the end face of the insulating film close to the bottom case is fitted with the surface of the bottom case on one side of the second cavity; the end face of the insulating film away from the bottom case is fixedly connected to the heat conductive pad, and an integrated heat dissipation block is fixedly provided on the side of the heat conductive pad away from the bottom case.

[0018] More preferably, the projected area of the integrated fixing block on the surface of the bottom case covers the positions of the copper rows and relays of the load circuit and the charging circuit.

[0019] More preferably, countersunk bolt holes are further provided at one ends of the first copper row, the main discharge positive copper row, the main discharge negative copper row, the second copper row, the fast charge positive copper row, and the fast charge negative copper row connected to the relays of the load circuit and the charging circuit, and countersunk bolts are embedded in the countersunk bolt holes for fastening the copper rows and the relays; the countersunk bolts do not exceed the reference plane.

[0020] Preferably, the high-voltage harness unit includes a high-voltage bus bar and a plurality of high-voltage sampling branch lines; the high-voltage bus bar is electrically connected to the high-voltage interface located on the upper case; one ends of the plurality of high-voltage sampling branch lines are electrically connected to the high-voltage bus bar, and the other ends of the plurality of high-voltage sampling branch lines are respectively electrically connected to the first copper row, the main discharge positive copper row, the main discharge negative copper row, the battery pack negative copper row, the fast charge positive copper row, and the fast charge negative copper row in one-to-one correspondence.

[0021] Further preferably, the low-voltage harness unit includes a low-voltage bus bar and a plurality of low-voltage sampling branch lines; the low-voltage bus bar is electrically connected to the low-voltage interface provided on the upper case, and the low-voltage bus bar is also electrically connected to one ends of the plurality of low-voltage sampling branch lines, and the other ends of the plurality of low-voltage sampling branch lines are respectively electrically connected to the control ends of the main discharge positive relay, the main discharge negative relay, the fast charge main positive relay, and the fast charge main negative relay; the routing directions of the high-voltage bus bar and the low-voltage bus bar are different; the distance between the high-voltage sampling branch line and the bottom case during routing does not exceed the distance between the low-voltage sampling branch line and the bottom case during routing.

[0022] A BDU structure with balanced heat dissipation provided by the present utility model has the following compared with the prior art

[0023] Beneficial effects:

[0024] (1) This application adopts an integrated heat dissipation unit structure. During discharging, the heat generated by the load circuit can be transferred through the heat conductive pad and the heat sink block to the heat dissipation area corresponding to the non-operating charging circuit. Conversely, during charging, the heat generated by the charging circuit can also be guided through the heat conductive pad and the heat sink block to the heat dissipation area corresponding to the non-operating load circuit. Due to the shared integrated heat dissipation structure, the effect of balanced heat dissipation can be better achieved;

[0025] (2) The partition ribs on each relay can isolate adjacent copper bars and slow down the heating rate of radiative heat transfer; (3) The wiring directions and wiring heights of the high-voltage wire harness unit and the low-voltage wire harness unit are not completely the same, which can effectively improve the problem of cross-interference between high- and low-voltage signals and is also beneficial to the air circulation in the first cavity. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Figure 1 Is a three-dimensional view of a BDU structure with balanced heat dissipation of the present utility model;

[0028] Figure 2 Is a three-dimensional view of another posture of a BDU structure with balanced heat dissipation of the present utility model;

[0029] Figure 3 Is an exploded three-dimensional view of a BDU structure with balanced heat dissipation of the present utility model;

[0030] Figure 4 Is a three-dimensional view of a BDU structure with balanced heat dissipation of the present utility model after removing the upper shell;

[0031] Figure 5 Is a bottom view of a BDU structure with balanced heat dissipation of the present utility model after removing the integrated heat dissipation unit;

[0032] Figure 6 Is a bottom view of the load circuit and the charging circuit of a BDU structure with balanced heat dissipation of the present utility model after removing the bottom shell.

[0033] Reference numerals: 1, upper shell; 2, bottom shell; 100, first cavity; 200, second cavity; 3, load circuit; 4, charging circuit; 5, high-voltage harness unit; 6, low-voltage harness unit; 7, integrated heat dissipation unit; 30, main positive discharge relay; 31, main negative discharge relay; 32, battery pack positive copper busbar; 33, main fuse; 34, first copper busbar; 35, main positive discharge copper busbar; 36, main negative discharge copper busbar; 37, second copper busbar; 38, shunt; 39, battery pack negative copper busbar; 40, main positive fast charge relay; 41, main negative fast charge relay; 42, fast charge positive copper busbar; 43, fast charge negative copper busbar; 300, first card slot; 400, second card slot; 500, blocking rib; 71, insulating film; 72, heat-conducting pad; 73, integrated heat dissipation block; 51, high-voltage bus; 52, high-voltage sampling branch line; 61, low-voltage bus; 62, low-voltage sampling branch line. Detailed implementation manners

[0034] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] As Figures 1-5 shown, the present invention provides a BDU structure with balanced heat dissipation, including an upper shell 1, a bottom shell 2, a load circuit 3, a charging circuit 4, a high-voltage harness unit 5, a low-voltage harness unit 6, and an integrated heat dissipation unit 7.

[0036] Specifically, the interior of the upper shell 1 is hollow, which is used to provide a certain degree of protection for the load circuit, charging circuit, high-voltage harness unit, and low-voltage harness unit on this side; identifiers for prompting wiring can also be set on the surface of the upper shell 1.

[0037] One side of the bottom shell 2 close to the upper shell 1 and the upper shell 1 enclose to form a first cavity 100, and the side far from the upper shell 1 has a second cavity 200; the first cavity 100 is used to accommodate the load circuit, charging circuit, high-voltage harness unit, and low-voltage harness unit on this side; the second cavity 200 is used to accommodate the integrated heat dissipation unit 7.

[0038] The load circuit 3 is used to transfer the energy of the battery module to the load motor. The load circuit 3 is arranged in the first cavity 100 and extends in the direction of the second cavity 200. The load circuit 3 is used to output electric energy.

[0039] The charging circuit 4 is used to transfer the energy of the charging gun to the battery module. The charging circuit 4 is arranged in the first cavity 100 and extends towards the direction of the second cavity 200. The charging circuit 4 is used for charging.

[0040] The high-voltage harness unit 5 is arranged in the first cavity 100 and is used to obtain the high-voltage sampling signal when the load circuit 3 or the charging circuit 4 is working;

[0041] The low-voltage harness unit 6 is arranged in the first cavity 100 and is used to obtain the low-voltage sampling signal when the load circuit 3 or the charging circuit 4 is working; The high-voltage harness unit 5 and the low-voltage harness unit are used to obtain the voltage or current sampling signals at the corresponding positions and output them.

[0042] Among them, the distance between the sampling end of the high-voltage harness unit 5 and the bottom case 2 is not exactly the same as the distance between the sampling end of the low-voltage harness unit 6 and the bottom case 2; An integrated heat dissipation unit 7 is arranged in the second cavity 200, and the integrated heat dissipation unit 7 is adapted to the height of the second cavity 200. The integrated heat dissipation unit 7 is entirely hidden inside the second cavity and does not exceed the boundary range of the bottom case 2. The layout methods of the high-voltage harness unit 5 and the low-voltage harness unit 6 are different, and the wiring directions are also different, which can effectively avoid the mutual crosstalk of high and low voltage signals.

[0043] Combined Figure 5 and Figure 6 , the load circuit 3 includes a discharge main positive relay 30, a discharge main negative relay 31, a battery pack positive copper bar 32, a main fuse 33, a first copper bar 34, a discharge main positive copper bar 35, a discharge main negative copper bar 36, a second copper bar 37, a shunt 38 and a battery pack negative copper bar 39; One end of the battery pack positive copper bar 32 is electrically connected to the positive electrode of the battery module, the other end of the battery pack positive copper bar 32 is electrically connected to one end of the main fuse 33, the other end of the main fuse 33 is electrically connected to one end of the first copper bar 34, the other end of the first copper bar 34 is electrically connected to the first terminal of the discharge main positive relay 30, one end of the discharge main positive copper bar 35 is electrically connected to the second terminal of the discharge main positive relay 30, and the other end of the discharge main positive copper bar 35 is electrically connected to the positive electrode of the load motor; The negative electrode of the load motor is electrically connected to one end of the discharge main negative copper bar 36, the other end of the discharge main negative copper bar 36 is electrically connected to the first terminal of the discharge main negative relay 31, one end of the second copper bar 37 is electrically connected to the second terminal of the discharge main negative relay 31, the other end of the second copper bar 37 is electrically connected to one end of the shunt 38, the other end of the shunt 38 is electrically connected to one end of the battery pack negative copper bar 39, and the other end of the battery pack negative copper bar 39 is electrically connected to the negative electrode of the battery module. The load motor in the figure is an external device, so it is marked with a dashed box.

[0044] In the external output discharge mode, the load circuit 3 is externally connected to a load motor. The specific output loop is that the positive copper row 32 of the battery pack, the main fuse 33, the first copper row 34, the main positive discharge relay 30, and the main positive discharge copper row 35 are connected in sequence. The positive copper row 32 of the battery pack is electrically connected to the positive electrode of the battery module, and the main positive discharge copper row 35 is connected to the positive electrode of the load motor, forming a discharge path for the positive electrode during loading. In addition, the main negative discharge copper row 36, the main negative discharge relay 31, the second copper row 37, the shunt 38, and the negative copper row 39 of the battery pack are connected in sequence. The main negative discharge copper row 36 is connected to the negative electrode of the load motor, and the negative copper row 39 of the battery pack is electrically connected to the negative electrode of the battery module, constituting a discharge path for the negative electrode during loading. The main positive discharge relay 30 and the main negative discharge relay 31 are controlled by an external controller, such as a BMS, to make the first terminal and the second terminal of the main positive discharge relay 30 and the main negative discharge relay 31 conduct.

[0045] Similarly, as Figure 5 and Figure 6 shown, the charging circuit 4 includes a fast charging main positive relay 40, a fast charging main negative relay 41, a fast charging positive copper row 42, and a fast charging negative copper row 43; one end of the fast charging positive copper row 42 is electrically connected to the positive electrode of the charging gun, the other end of the fast charging positive copper row 42 is electrically connected to the first terminal of the fast charging main positive relay 40, and the second terminal of the fast charging main positive relay 40 is also electrically connected to a non-end position of the first copper row 34; the first terminal of the fast charging main negative relay 41 is also electrically connected to the second copper row 37, the second terminal of the fast charging main negative relay 41 is electrically connected to one end of the fast charging negative copper row 43, and the other end of the fast charging negative copper row 43 is electrically connected to the negative electrode of the charging gun; a number of through first slots 300 are provided on the base, and the first slots 300 communicate the first cavity 100 and the second cavity 200 with each other; the positive copper row 32 of the battery pack, the first copper row 34, the main positive discharge copper row 35, the main negative discharge copper row 36, the second copper row 37, the shunt 38, the negative copper row 39 of the battery pack, the fast charging positive copper row 42, and the fast charging negative copper row 43 are fixedly arranged in one-to-one correspondence with the number of first slots 300. The charging gun in the drawing is an external device and is also represented by a dotted line box.

[0046] In the charging mode, in addition to its own components, in order to form a loop with the battery module, the charging circuit 4 shares some components with the load circuit 3, and the energy flow direction is different from that of the load circuit. The specific structure is as Figure 6As shown in the figure, the fast-charging positive copper busbar 42, the fast-charging main positive relay 40, the first copper busbar 34, the main fuse 33, and the battery pack positive copper busbar 32 are connected in sequence. The fast-charging positive copper busbar 42 is electrically connected to the positive electrode of the charging gun, and the battery pack positive copper busbar 32 is electrically connected to the positive electrode of the battery module, forming a charging path for the positive electrode during charging; the fast-charging negative copper busbar 43, the fast-charging main negative relay 41, the second copper busbar 37, the shunt 38, and the battery pack negative copper busbar 39 are connected in sequence. The fast-charging negative copper busbar 43 is electrically connected to the negative electrode of the charging gun, and the battery pack negative copper busbar 39 is electrically connected to the negative electrode of the battery module, forming a charging path for the negative electrode during charging.

[0047] As a preferred embodiment of the present invention, the battery pack positive copper busbar 32, the first copper busbar 34, the discharge main positive copper busbar 35, the discharge main negative copper busbar 36, the second copper busbar 37, the battery pack negative copper busbar 39, the fast-charging positive copper busbar 42, and the fast-charging negative copper busbar 43 pass through the first card slot 300 and extend into the end face of the second cavity 200, and are all located in the same reference plane. Each copper busbar of the present application has the same thickness and the same dimension extending into the second cavity, which is to achieve a coplanar effect and better fit with the integrated heat dissipation unit 7.

[0048] As Figure 5 As shown in the figure, as another preferred embodiment of the present invention, several second card slots 400 are provided on the bottom case 2; on the side of the discharge main positive relay 30, the discharge main negative relay 31, the fast-charging main positive relay 40, and the fast-charging main negative relay 41 close to the bottom case 2, there are provided blocking ribs 500; one end of the blocking rib 500 is fixedly connected to the surface of the discharge main positive relay 30, the discharge main negative relay 31, the fast-charging main positive relay 40, and the fast-charging main negative relay 41 on the side close to the bottom case 2, and the other end of the blocking rib 500 passes through the second card slot 400 and extends towards the second cavity 200; the distance that the blocking rib 500 extends into the second cavity 200 does not exceed the reference plane. It can be seen that the area between adjacent copper busbars is limited by the blocking rib 500, which can reduce the influence of radiation heat dissipation of adjacent copper busbars and is beneficial to the heat of the copper busbars being led out towards the integrated heat dissipation unit. The cross-section of the illustrated blocking rib 500 is dumbbell-shaped, large at both ends and small in the middle, and the shape of the second card slot 400 is similar to it, which can improve the stability of the combination of each relay and the bottom case 2.

[0049] As Figure 3As shown in the figure, the integrated heat dissipation unit 7 includes an insulating film 71, a heat conducting pad 72, and an integrated heat dissipation block 73. On one side of the insulating film 71 close to the bottom case 2, a number of embedded grooves are provided. The inner surfaces of the a number of embedded grooves are in contact with the end faces of the battery pack positive copper busbar 32, the first copper busbar 34, the main discharge positive copper busbar 35, the main discharge negative copper busbar 36, the second copper busbar 37, the battery pack negative copper busbar 39, the fast charge positive copper busbar 42, and the fast charge negative copper busbar 43 that pass through the first card slot 300 and extend into the second cavity 200. The end face of the insulating film 71 close to the bottom case 2 is in contact with the surface of the bottom case 2 on one side of the second cavity 200. The end face of the insulating film 71 away from the bottom case 2 is fixedly connected to the heat conducting pad. On the side of the heat conducting pad 72 away from the bottom case 2, an integrated heat dissipation block 73 is fixedly provided. In order to fully cover the heat generation area, in this embodiment, the projected area of the integrated fixing block on the surface of the bottom case 2 covers the positions of the copper busbars and relays of the load circuit 3 and the charging circuit 4. The heat conducting pad 72 can also be designed in this way to better conduct heat, so that the entire integrated heat dissipation block 73 can be put into use and has a larger heat dissipation area. During discharge, the heat generated by the load circuit 3 can be transferred through the heat conducting pad 72 and the integrated heat dissipation block 73 to the heat dissipation area corresponding to the unoperated charging circuit 4. Conversely, during charging, the heat generated by the charging circuit 4 can also be guided through the heat conducting pad 72 and the heat dissipation block 73 to the heat dissipation area corresponding to the unoperated load circuit 3. Due to the shared integrated heat dissipation unit, the effect of better heat dissipation balance can be achieved. The surface of the integrated heat dissipation block 73 has a number of protruding fins, which is beneficial to increasing the heat exchange area with the air.

[0050] Although the copper busbars are fixed to the bottom case by an integral molding method, in order to connect to the relay, fasteners need to be used. In order to prevent the height of the fasteners from exceeding the reference plane, counterbore bolt holes are opened on the first copper busbar 34, the main discharge positive copper busbar 35, the main discharge negative copper busbar 36, the second copper busbar 37, the fast charge positive copper busbar 42, and the fast charge negative copper busbar 43 that are connected to the relays of the load circuit 3 and the charging circuit 4. Countersunk bolts are embedded in the counterbore bolt holes, and the countersunk bolts are used to fasten the copper busbars and the relays; the countersunk bolts do not exceed the reference plane. An embedded structure is adopted to prevent the bolts from exceeding the reference plane and affecting the fitting effect between the copper busbars and the integrated heat dissipation unit 7.

[0051] As Figure 4 shown in the figure, the high-voltage harness unit 5 includes a high-voltage busbar 51 and a number of high-voltage sampling branch lines 52. The high-voltage busbar 51 is electrically connected to the high-voltage interface located on the upper case 1. One ends of the a number of high-voltage sampling branch lines 52 are electrically connected to the high-voltage busbar 51, and the other ends of the a number of high-voltage sampling branch lines 52 are respectively and electrically connected to the first copper busbar 34, the main discharge positive copper busbar 35, the main discharge negative copper busbar 36, the battery pack negative copper busbar 39, the fast charge positive copper busbar 42, and the fast charge negative copper busbar 34 in one-to-one correspondence.

[0052] Similarly, asFigure 4 As shown in the figure, the low-voltage wiring harness unit 6 includes a low-voltage busbar 61 and several low-voltage sampling branch lines 62; the low-voltage busbar 61 is electrically connected to the low-voltage interface provided on the upper shell 1, and the low-voltage busbar 61 is also electrically connected to one end of several low-voltage sampling branch lines, and the other ends of several low-voltage sampling branch lines are respectively electrically connected to the control terminals of the discharge main positive relay 30, the discharge main negative relay 31, the fast charge main positive relay 40, and the fast charge main negative relay 41; the routing direction of the high-voltage busbar 51 is different from that of the low-voltage busbar 61; when the high-voltage sampling branch line 52 is routed, the distance from the bottom case 2 does not exceed the distance from the low-voltage sampling branch line 62 to the bottom case 2 when routed.

[0053] As can be seen from the figure, the routing path of the high-voltage busbar 51 is routed in an L-shaped manner along the fast charge main negative relay 41, the fast charge main positive relay 40, and the discharge main positive relay 30, while the low-voltage busbar 61 is routed in an L-shaped manner along the fast charge main negative relay 41, the discharge main negative relay 31, and the discharge main positive relay 30, and the two do not cross each other. Only the ends of the high-voltage busbar 51 and the low-voltage busbar 61 near the high-voltage interface and the low-voltage interface are relatively close. The height of the high-voltage sampling branch line 52 led out from the high-voltage busbar is significantly different from the height of the low-voltage sampling branch line 62 led out from the low-voltage busbar. This is also to ensure the smooth air flow inside the first cavity 100, facilitate heat dissipation, simplify the wiring layout, and prevent signal crosstalk between adjacent cables.

[0054] The above is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A BDU structure with balanced heat dissipation, characterized in that: include: Upper shell (1); The bottom shell (2) has a side close to the upper shell (1) and is surrounded by the upper shell (1) to form a first cavity (100), and a side away from the upper shell (1) has a second cavity (200); A load circuit (3) is arranged in the first cavity (100) and extends in the direction of the second cavity (200); A charging circuit (4) is arranged in the first cavity (100) and extends in the direction of the second cavity (200); A high-voltage wire harness unit (5) is arranged in the first cavity (100); A low-voltage wiring harness unit (6) is disposed in the first cavity (100); The distance between the sampling end of the high-voltage wiring harness unit (5) and the bottom shell (2) is not completely the same as the distance between the sampling end of the low-voltage wiring harness unit (6) and the bottom shell (2); an integrated heat dissipation unit (7) is arranged in the second cavity (200), and the integrated heat dissipation unit (7) is adapted to the height of the second cavity (200).

2. A BDU structure with balanced heat dissipation according to claim 1, characterized in that: The load circuit (3) comprises a discharge main positive relay (30), a discharge main negative relay (31), a battery pack positive copper bar (32), a main fuse (33), a first copper bar (34), a discharge main positive copper bar (35), a discharge main negative copper bar (36), a second copper bar (37), a shunt (38) and a battery pack negative copper bar (39); one end of the battery pack positive copper bar (32) is electrically connected to the positive electrode of the battery module, the other end of the battery pack positive copper bar (32) is electrically connected to one end of the main fuse (33), the other end of the main fuse (33) is electrically connected to one end of the first copper bar (34), the other end of the first copper bar (34) is electrically connected to the first terminal of the discharge main positive relay (30), and the discharge main One end of the positive copper bar (35) is electrically connected to the second terminal of the discharge main positive relay (30), and the other end of the discharge main positive copper bar (35) is electrically connected to the positive pole of the load motor; the negative pole of the load motor is electrically connected to one end of the discharge main negative copper bar (36), and the other end of the discharge main negative copper bar (36) is electrically connected to the first terminal of the discharge main negative relay (31); one end of the second copper bar (37) is electrically connected to the second terminal of the discharge main negative relay (31), and the other end of the second copper bar (37) is electrically connected to one end of the shunt (38), and the other end of the shunt (38) is electrically connected to one end of the battery pack negative copper bar (39), and the other end of the battery pack negative copper bar (39) is electrically connected to the negative pole of the battery module.

3. A BDU structure with balanced heat dissipation according to claim 2, characterized in that: The charging circuit (4) comprises a fast-charging main positive relay (40), a fast-charging main negative relay (41), a fast-charging positive copper bar (42) and a fast-charging negative copper bar (43); one end of the fast-charging positive copper bar (42) is electrically connected to the positive pole of the charging gun, the other end of the fast-charging positive copper bar (42) is electrically connected to the first terminal of the fast-charging main positive relay (40), and the second terminal of the fast-charging main positive relay (40) is also electrically connected to the non-end position of the first copper bar (34); the first terminal of the fast-charging main negative relay (41) is also electrically connected to the second copper bar (37), and the second terminal of the fast-charging main negative relay (41) is electrically connected to the fast-charging negative copper bar (34). One end of the fast-charging negative copper bar (43) is electrically connected, and the other end of the fast-charging negative copper bar (43) is electrically connected to the negative electrode of the charging gun; a plurality of through first card slots (300) are arranged on the base, and the first card slots (300) connect the first cavity (100) and the second cavity (200) to each other; the battery pack positive copper bar (32), the first copper bar (34), the discharge main positive copper bar (35), the discharge main negative copper bar (36), the second copper bar (37), the shunt (38), the battery pack negative copper bar (39), the fast-charging positive copper bar (42) and the fast-charging negative copper bar (43) are fixedly arranged in a one-to-one correspondence with the plurality of first card slots (300).

4. The BDU structure with balanced heat dissipation according to claim 3, characterized in that: The battery pack positive copper bar (32), the first copper bar (34), the discharge main positive copper bar (35), the discharge main negative copper bar (36), the second copper bar (37), the battery pack negative copper bar (39), the fast-charging positive copper bar (42) and the fast-charging negative copper bar (43) extend through the first slot (300) into the end surface of the second cavity (200), and are all located in the same reference plane.

5. The BDU structure with balanced heat dissipation according to claim 4, characterized in that: The bottom shell (2) is provided with a plurality of second slots (400); a blocking rib (500) is provided on one side of the discharge main positive relay (30), the discharge main negative relay (31), the fast charging main positive relay (40) and the fast charging main negative relay (41) close to the bottom shell (2); one end of the blocking rib (500) is fixedly connected to the surface of the discharge main positive relay (30), the discharge main negative relay (31), the fast charging main positive relay (40) and the fast charging main negative relay (41) close to the bottom shell (2), and the other end of the blocking rib (500) passes through the second slot (400) and extends in the direction of the second cavity (200); the distance that the blocking rib (500) extends into the second cavity (200) does not exceed the reference plane.

6. The BDU structure with balanced heat dissipation according to claim 3, characterized in that: The integrated heat dissipation unit (7) comprises an insulating film (71), a thermal pad (72) and an integrated heat dissipation block (73); a plurality of embedded grooves are provided on a side of the insulating film (71) close to the bottom shell (2); the inner surfaces of the plurality of embedded grooves are in contact with the end surfaces of the battery pack positive copper bar (32), the first copper bar (34), the discharge main positive copper bar (35), the discharge main negative copper bar (36), the second copper bar (37), the battery pack negative copper bar (39), the fast charging positive copper bar (42) and the fast charging negative copper bar (43) extending through the first card slot (300) into the second cavity (200); the end surface of the insulating film (71) close to the bottom shell (2) is in contact with the surface of the bottom shell (2) located on one side of the second cavity (200); the end surface of the insulating film (71) away from the bottom shell (2) is fixedly connected to the thermal pad (72); and the integrated heat dissipation block (73) is fixedly provided on the side of the thermal pad (72) away from the bottom shell (2).

7. The BDU structure with balanced heat dissipation according to claim 6, characterized in that: The projection area of ​​the integrated fixing block on the surface of the bottom shell (2) covers the locations of the copper bars and relays of the load circuit (3) and the charging circuit (4).

8. The BDU structure with balanced heat dissipation according to claim 6, characterized in that: The first copper bar (34), the main positive copper bar for discharge (35), the main negative copper bar for discharge (36), the second copper bar (37), the fast-charging positive copper bar (42) and the fast-charging negative copper bar (43) are also provided with countersunk bolt holes at one end connected to the relays of the load circuit (3) and the charging circuit (4), and countersunk bolts are embedded in the countersunk bolt holes. The countersunk bolts are used to fasten the copper bars and the relays; the countersunk bolts do not extend beyond the reference plane.

9. The BDU structure with balanced heat dissipation according to claim 3, characterized in that: The high-voltage wiring harness unit (5) comprises a high-voltage busbar (51) and a plurality of high-voltage sampling branches (52); the high-voltage busbar (51) is electrically connected to a high-voltage interface located on the upper shell (1); one end of the plurality of high-voltage sampling branches (52) is electrically connected to the high-voltage busbar (51), and the other ends of the plurality of high-voltage sampling branches (52) are electrically connected to the first copper busbar (34), the main positive copper busbar (35) for discharge, the main negative copper busbar (36) for discharge, the negative copper busbar (39) for battery pack, the positive copper busbar (42) for fast charge, and the negative copper busbar (43) for fast charge, respectively.

10. The BDU structure with balanced heat dissipation according to claim 9, characterized in that: The low-voltage wiring harness unit (6) comprises a low-voltage busbar (61) and a plurality of low-voltage sampling branches (62); the low-voltage busbar (61) is electrically connected to a low-voltage interface arranged on the upper shell (1), the low-voltage busbar (61) is also electrically connected to one end of the plurality of low-voltage sampling branches, and the other ends of the plurality of low-voltage sampling branches are respectively electrically connected to the control ends of the discharge main positive relay (30), the discharge main negative relay (31), the fast-charging main positive relay (40) and the fast-charging main negative relay (41); the routing directions of the high-voltage busbar (51) and the low-voltage busbar (61) are different; the distance of the high-voltage sampling branch line (52) from the bottom shell (2) when routing does not exceed the distance of the low-voltage sampling branch line (62) from the bottom shell (2) when routing.

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