Composite cross beam and battery pack thereof

Abstract

The utility model discloses a composite cross beam and a battery pack thereof. The composite cross beam comprises an injection molding shell, a profile structure, a base and a connecting bolt, the profile structures and the insulating sheets are arranged at intervals, the injection molding shell, the profile structures and the insulating sheets are connected into a whole through an embedded injection molding process, the upper ends of the profile structures are provided with open grooves for placing one ends of the lap joint aluminum bars, and the other ends of the lap joint aluminum bars upwards penetrate through the injection molding shell and are bent towards one side close to the battery cell module; an output aluminum bar is arranged above the outermost battery cell module, and one end, far away from the battery cell module, of the output aluminum bar is arranged in the injection molding shell through a countersunk bolt; the base is fixedly arranged on the inner bottom surface of the battery box body, and the connecting bolt is used for connecting the profile structure and the base together. According to the utility model, by arranging the injection molding shell, the profile structure, the base and the composite cross beam connected by the connecting bolts, on one hand, the insulation sheet can be well limited; on the other hand, the weight of the whole beam can be reduced.

Description

Technical Field

[0001] This utility model relates to the field of battery box structure technology, specifically to a composite beam and its battery pack. Background Technology

[0002] The insulating sheets of the existing battery box are prone to displacement due to vibration, causing insulation failure between the module and the box. In addition, the existing metal crossbeam requires additional insulating sheets, conductive aluminum busbars and output stage bases, which increases the weight. Typically, the weight of a single crossbeam is greater than 2.3 kg, which limits the energy density of the battery pack.

[0003] Therefore, it is urgent to propose a new solution to the above problems. Summary of the Invention

[0004] This invention provides a composite beam and its battery pack, which can solve the problems in the prior art where the insulating sheet is easily displaced by vibration, leading to insulation failure and the weight of the single beam is too large.

[0005] This utility model provides a composite beam, comprising: an injection-molded shell, a profile structure, a base, and connecting bolts;

[0006] The profile structure and insulating sheet are spaced apart. The injection-molded housing, profile structure and insulating sheet are connected as a whole by an in-mold injection molding process. The upper end of the profile structure has a slot for placing one end of the overlapping aluminum busbar. The other end of the overlapping aluminum busbar passes upward through the injection-molded housing and bends towards the side closer to the cell module. Two adjacent cell modules are connected by the overlapping aluminum busbar. An output aluminum busbar is provided above the outermost cell module. The end of the output aluminum busbar away from the cell module is set in the injection-molded housing by a countersunk bolt.

[0007] The base is fixedly installed on the inner bottom surface of the battery box, and the connecting bolts are used to connect the profile structure and the base together.

[0008] Furthermore, the bottom end of the profile structure is provided with a stepped portion formed by bending, and the upper end of the base is provided with a bent section corresponding to the stepped portion.

[0009] Furthermore, the opening of the stepped portion faces away from the battery cell module, and the surface of the stepped portion that contacts the base is provided with a serrated structure for preventing loosening.

[0010] Furthermore, the two sides of the slot are provided with guide parts to guide the up and down movement of the connecting bolts.

[0011] Furthermore, the injection-molded housing has a protrusion that mates with the groove, and multiple openings are spaced apart in the protrusion. The openings are located above the guide portion, and a space is formed between the openings and the guide portion for inserting connecting bolts.

[0012] Furthermore, the profile structure is provided with multiple cavities for weight reduction.

[0013] Furthermore, the multiple connecting bolts are evenly spaced along the length of the injection-molded housing.

[0014] Furthermore, the profile structure is made of aluminum alloy.

[0015] Furthermore, the profile structure, overlapping aluminum busbar and connecting bolt are embedded components, and output electrode bases are respectively provided on the overlapping aluminum busbar and output aluminum busbar. The injection molded shell, insulating sheet and output electrode base are injection molded layers, and the composite beam is processed by embedded injection molding.

[0016] This utility model also provides a battery pack, including the aforementioned composite beam.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0018] 1. This utility model features a composite beam consisting of an injection-molded shell, a profile structure, a base, and connecting bolts. The injection-molded shell, profile structure, and insulating sheet are connected as a whole through an embedded injection molding process. The overlapping aluminum busbar, output aluminum busbar, and insulating sheet are integrated into this composite beam. On the one hand, this effectively limits the position of the insulating sheet, reducing the insulation failure rate from the current 12% to 5%. On the other hand, it eliminates the need for additional insulating sheets, conductive aluminum busbars, and output stage bases, reducing the overall weight of the beam. Finally, the embedded injection molding process significantly improves installation efficiency.

[0019] 2. This utility model ensures the installation accuracy of the composite beam by setting mutually cooperating stepped parts and bending sections. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the battery box of this utility model;

[0021] Figure 2 This is an exploded view of the overall structure of the battery box of this utility model;

[0022] Figure 3 for Figure 2 Enlarged schematic diagram of the structure at point A in the middle;

[0023] Figure 4 This is an exploded view of the composite beam structure of this utility model;

[0024] Figure 5 This is a schematic diagram of the composite beam structure of this utility model;

[0025] Figure 6 for Figure 5 Enlarged schematic diagram of the structure at point B;

[0026] Figure 7 This is a side view of the composite beam of this utility model;

[0027] Figure 8 This is a schematic diagram of the injection-molded housing of this utility model;

[0028] Reference numerals: 1. Injection-molded housing; 11. Opening; 12. Protrusion; 2. Profile structure; 21. Slot; 211. Guide part; 22. Stepped part; 23. Cavity; 3. Insulating sheet; 41. Overlapping aluminum busbar; 42. Output aluminum busbar; 43. Countersunk bolt; 5. Battery cell module; 6. Connecting bolt; 6. Battery box; 61. Base. Detailed Implementation

[0029] To further understand the utility model's content, features, and effects, the following embodiments are provided, along with accompanying drawings. Figures 1-8 The details are as follows.

[0030] like Figures 1-8 As shown, this embodiment provides a composite beam, including: an injection-molded shell 1, a profile structure 2, a base 71, and connecting bolts 6;

[0031] The profile structure 2 and the insulating sheet 3 are spaced apart. The injection molded housing 1, the profile structure 2 and the insulating sheet 3 are connected into a whole by an embedded injection molding process. The gap between the profile structure 2 and the insulating sheet 3 is filled by the injection molded housing 1. The upper end of the profile structure 2 is provided with a slot 21 for placing one end of the overlapping aluminum busbar 41. The other end of the overlapping aluminum busbar 41 passes upward through the injection molded housing 1 and bends towards the side closer to the cell module 5. Two adjacent cell modules 5 are connected by the overlapping aluminum busbar 41. An output aluminum busbar 42 is provided above the outermost cell module 5. The end of the output aluminum busbar 42 away from the cell module 5 is set in the injection molded housing 1 by a countersunk bolt 43. In this embodiment, three cell modules 5 are provided, two of which are connected by a single overlapping aluminum busbar 41, and the other cell module 5 is provided with an output aluminum busbar 42. The injection molded housing 1 can be made of PA66+30% glass fiber material.

[0032] The base 71 is fixedly installed on the inner bottom surface of the battery box 7 by welding, and the connecting bolt 6 is used to connect the profile structure 2 and the base 71 together.

[0033] This invention utilizes a composite beam consisting of an injection-molded shell, a profile structure, a base, and connecting bolts. The injection-molded shell, profile structure, and insulating sheet are connected as a whole through an embedded injection molding process. The overlapping aluminum busbar, output aluminum busbar, and insulating sheet are integrated within this composite beam. This design effectively limits the position of the insulating sheet, reducing the insulation failure rate from the current 12% to 5%. Furthermore, it eliminates the need for additional insulating sheets, conductive aluminum busbars, and output stage bases, thus reducing the overall weight of the beam. Finally, the embedded injection molding process significantly improves installation efficiency.

[0034] In this embodiment, as Figure 7 As shown, the bottom end of the profile structure 2 is provided with a stepped part 22 formed by bending, and the upper end of the base 71 is provided with a bent section that matches the stepped part 22. By providing the stepped part and the bent section that cooperate with each other, the installation accuracy of the composite beam is ensured, and the installation accuracy does not exceed 0.01mm.

[0035] In this embodiment, as Figure 7 As shown, the opening of the stepped portion 22 faces away from the battery cell module 5, opposite to the bending direction of the overlapping aluminum strip 41, thus avoiding damage to the battery cell module 5. In addition, the surface of the stepped portion 22 and the base 71 that come into contact is provided with a serrated structure for preventing loosening, which improves the overall vibration resistance.

[0036] In this embodiment, as Figure 3 As shown, the two sides of the slot 21 are provided with guide parts 211 to guide the up and down movement of the connecting bolt 6, which facilitates the installation of the connecting bolt 6 and improves the overall assembly accuracy.

[0037] In this embodiment, as Figure 3 , 4 As shown in Figure 8, the injection-molded housing 1 has a protrusion 12 that mates with the slot 21. Multiple openings 11 are spaced apart in the protrusion 12. In this embodiment, there are 5 openings, but other numbers can be set as needed. The openings 11 are located above the guide part 211. A space is formed between the openings 11 and the guide part 211 for inserting the connecting bolts 6. This facilitates the installation of the connecting bolts 6 and also facilitates the connection between the profile structure 2 and the base 71.

[0038] In this embodiment, as Figure 7 As shown, the profile structure 2 is provided with multiple cavities 23 for weight reduction, which reduces the overall weight. Compared with the existing crossbeam's 2.3kg, the composite crossbeam of this embodiment weighs only 1.77kg.

[0039] In this embodiment, as Figure 2As shown, the five connecting bolts 6 are evenly spaced along the length of the injection-molded housing 1, which makes the connection of the entire composite beam more secure.

[0040] In this embodiment, the profile structure 2 is made of aluminum alloy, which makes the overall weight lighter while ensuring the structural strength requirements and the construction of the inlay injection molding process.

[0041] In this embodiment, the profile structure 2, the overlapping aluminum busbar 41 and the connecting bolt 6 are embedded components. The overlapping aluminum busbar 41 and the output aluminum busbar 42 are respectively provided with output pole bases (not shown in the figure). The injection molded housing 1, the insulating sheet 3 and the output pole base are injection molded layers. The composite beam is processed by the embedded injection molding process.

[0042] The specific construction steps for the composite beam in this embodiment are as follows:

[0043] S1. Embedded component pretreatment: The aluminum alloy profile structure 2 is anodized after being machined by CNC lathe (film thickness 10μm), and the overlapping aluminum busbar 41 is laser cleaned (power 500W, frequency 1000Hz) to remove the oxide layer at the connection position.

[0044] S2. Use Moldflow software to simulate melt flow and optimize the gate position (side gate + fan gate combination). Perform heat treatment (80℃×4h) within 48 hours after injection molding to eliminate internal stress.

[0045] S3. After injection molding, use a CNC lathe to machine the countersunk holes for countersunk bolts 43, which are used to fasten the output aluminum busbar 42 to the composite beam.

[0046] This embodiment also provides a battery pack, including the aforementioned composite beam.

[0047] The above-described utility model only illustrates the implementation methods of the present utility model and should not be construed as limiting the scope of the utility model patent, nor is it a limitation on the structure of the present utility model embodiments in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present utility model embodiments, and these all fall within the protection scope of the present utility model embodiments.

Claims

1. A composite beam, characterized by include: The components include an injection-molded housing (1), a profile structure (2), a base (71), and connecting bolts (6); The profile structure (2) and the insulating sheet (3) are arranged at intervals. The injection molded housing (1), the profile structure (2) and the insulating sheet (3) are connected into a whole by an in-mold injection molding process. The upper end of the profile structure (2) is provided with a slot (21) for placing one end of the overlapping aluminum busbar (41). The other end of the overlapping aluminum busbar (41) passes through the injection molded housing (1) and bends towards the side closer to the cell module (5). Two adjacent cell modules (5) are connected by the overlapping aluminum busbar (41). An output aluminum busbar (42) is provided above the outermost cell module (5). The end of the output aluminum busbar (42) away from the cell module (5) is set in the injection molded housing (1) by a countersunk bolt (43). The base (71) is fixedly installed on the inner bottom surface of the battery box (7), and the connecting bolt (6) is used to connect the profile structure (2) and the base (71) together.

2. A composite beam according to claim 1, wherein: The bottom end of the profile structure (2) is provided with a stepped part (22) formed by bending, and the upper end of the base (71) is provided with a bent section that is connected to the stepped part (22).

3. A composite beam according to claim 2, wherein: The opening of the stepped portion (22) faces away from the battery cell module (5), and the surface of the stepped portion (22) that contacts the base (71) is provided with a serrated structure for preventing loosening.

4. The composite beam defined in Claim 1, wherein: The slot (21) has guide parts (211) on both sides to guide the up and down movement of the connecting bolt (6).

5. A composite beam according to claim 4, wherein: The injection-molded housing (1) has a protrusion (12) that mates with the slot (21). Multiple openings (11) are spaced apart in the protrusion (12). The openings (11) are located above the guide (211). A space for inserting the connecting bolt (6) is formed between the openings (11) and the guide (211).

6. The composite beam defined in Claim 1, wherein: The profile structure (2) is provided with multiple cavities (23) for weight reduction.

7. The composite beam defined in claim 1, wherein: The multiple connecting bolts (6) are evenly spaced along the length of the injection-molded housing (1).

8. The composite beam defined in Claim 1, wherein: The profile structure (2) is made of aluminum alloy.

9. The composite beam defined in claim 1, wherein: The profile structure (2), overlapping aluminum busbar (41) and connecting bolt (6) are embedded components. Output pole bases are respectively provided on the overlapping aluminum busbar (41) and output aluminum busbar (42). The injection molded housing (1), insulating sheet (3) and output pole base are injection molded layers. The composite beam is processed by embedded injection molding.

10. A battery pack, characterized by: Includes the composite beam as described in any one of claims 1 to 9.

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