Controlled fuse

Abstract

The utility model relates to the technical field of controlled fuses, in particular to a controlled fuse which comprises a first main circuit assembly, a second main circuit assembly and a control assembly located between the first main circuit assembly and the second main circuit assembly, the first main circuit assembly comprises a first electrode plate, a first support and first alloy, the first support is erected on the first electrode plate, and the second support is erected on the second electrode plate. The first main circuit assembly comprises a first electrode slice, a first support and a first alloy, the first alloy is connected with the first electrode slice, the second main circuit assembly comprises a second electrode slice, a second support and a second alloy, the second support is erected on the second electrode slice, the second alloy is connected with the second electrode slice, the control assembly comprises a heating element, a control alloy and a lead, the control alloy is adjacent to the heating element, and the lead is electrically connected with the control alloy and the heating element. Therefore, the controlled fuse has active fusing and passive fusing functions, and the risk of thermal runaway of the battery can be effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of controlled fuses, in particular to a controlled fuse with active and passive protection functions used between battery modules. Background Art

[0002] Currently, battery systems on the market primarily utilize a multi-stage module connected in series and parallel. Modules are electrically connected using aluminum or copper bars. If a single module fails and the connectors cannot be disconnected in time, heat can be conducted through them, affecting the thermal safety of adjacent modules. Furthermore, the modules are relatively compactly arranged within the battery system. When a module experiences thermal runaway, the arc jets containing conductive material can easily cause a localized internal short circuit even after the external relay is disconnected, exacerbating combustion in the single failed module and increasing the risk of thermal diffusion.

[0003] To solve the above problems, the present invention provides a controlled fuse with active and passive functions, which can melt the connection point due to overtemperature, and can also disconnect the connection point in accordance with the BMS control requirements to reduce the risk of battery thermal runaway.

[0004] It should be noted that the information disclosed in this background technology section is only intended to increase understanding of the overall background of the present invention, and should not be regarded as an admission or suggestion in any form that the information constitutes prior art already known to those skilled in the art. Utility Model Content

[0005] The utility model provides a controlled fuse, which includes a first main circuit component, a second main circuit component and a control component. The first main circuit component includes a first electrode sheet, a first bracket and a first main circuit alloy, the first bracket is mounted on the first electrode sheet, the first main circuit alloy is mounted on the first bracket and electrically connected to the first electrode sheet. The second main circuit component includes a second electrode sheet, a second bracket and a second main circuit alloy, the second bracket is mounted on the second electrode sheet, the second main circuit alloy is mounted on the second bracket and electrically connected to the second electrode sheet. The control component is arranged between the first main circuit component and the second main circuit component, the control component includes a heating element, a control alloy and a lead, the control alloy is arranged adjacent to the heating element, and the lead electrically connects the control alloy and the heating element.

[0006] Furthermore, the first main circuit assembly further includes a first sealant, and the second main circuit assembly further includes a second sealant. The first sealant is arranged between the first electrode sheet and the first bracket, and the second sealant is arranged between the second electrode sheet and the second bracket.

[0007] Furthermore, the first main circuit component also includes a first shell, and the second main circuit component also includes a second shell. The first shell is arranged on the first electrode sheet and covers the first bracket and the first main circuit alloy, and a cavity is formed between the first seal and the first shell. The second shell is arranged on the second electrode sheet and covers the second bracket and the second main circuit alloy, and a cavity is formed between the second seal and the second shell.

[0008] Furthermore, the number of the first main circuit alloy and the second main circuit alloy is n, where n≥1, and the first main circuit alloy and the second main circuit alloy are M-type alloy or N-type alloy.

[0009] Furthermore, the first bracket and the second bracket are provided with baffles and support rods arranged between the two baffles, the number of baffles is n+1, and the first main circuit alloy and the second main circuit alloy are respectively mounted on the support rods of the first bracket and the second bracket.

[0010] Furthermore, the height of the baffle is higher than the height of the first main circuit alloy, and the height of the baffle is higher than the height of the second main circuit alloy.

[0011] Furthermore, the melting point of the first main circuit alloy is lower than the melting point of the control alloy, and the melting point of the second main circuit alloy is lower than the melting point of the control alloy.

[0012] Furthermore, the heating element includes a first heating element and a second heating element, and the control component also includes a first metal sheet and a second metal sheet. The first metal sheet and the second metal sheet are located at opposite ends of the first heating element. The first metal sheet connects the first heating element and the second heating element, and the second metal sheet connects the first heating element and the second heating element, and the lead passes through the first metal sheet.

[0013] Furthermore, the surface of the control alloy is coated with a flux.

[0014] Furthermore, the first main circuit assembly, the second main circuit assembly and the control assembly are connected by rivets.

[0015] The utility model provides a controlled fuse, which is configured by combining electrode sheets, main circuit alloys, heating elements, control alloys and leads, so that the controlled fuse has both active and passive fusing functions. When abnormal temperature, abnormal current or abnormal voltage occurs between battery modules, the BMS detects the signal abnormality and quickly activates the control component through the lead, so that the controlled fuse can self-heat and cut off the main circuit, that is, quickly cut off the aluminum bar or copper busbar used for connection between battery modules, and then melt the heating circuit to protect the entire battery system. When thermal runaway occurs between battery modules, the temperature of the failed battery module rises rapidly, and the main circuit alloy is sensitive to temperature. Under the condition of rapid heat transfer from the aluminum bar and copper busbar, after reaching the set temperature, it can quickly melt and cut off the connection between the battery modules to protect the entire battery system.

[0016] Other features and beneficial effects of the present invention will be described in the following description, and some of the technical features and beneficial effects can be obviously derived from the description or understood by implementing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, some of the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a structural diagram of a controlled fuse provided by an embodiment of the present utility model;

[0019] Figure 2 This is an explosion diagram of a controlled fuse provided by an embodiment of the present utility model;

[0020] Figure 3A This is an exploded schematic diagram of a main circuit assembly provided by an embodiment of the present utility model;

[0021] Figure 3B This is a schematic structural diagram of a bracket provided by an embodiment of the present utility model;

[0022] Figure 4 This is a schematic structural diagram of a control assembly provided by an embodiment of the present utility model;

[0023] Figure 5 This is a schematic diagram of the structure of a controlled fuse used between aluminum bars;

[0024] Figure 6 This is a circuit diagram of a controlled fuse applied to a battery module.

[0025] Reference numerals:

[0026] 10-first main circuit assembly; 11-first electrode sheet; 12-first bracket; 13-first main circuit alloy; 14-first sealing member; 15-first housing; 20-second main circuit assembly; 30-control assembly; 31-first heating element; 32-second heating element; 33-control alloy; 34-lead; 35-first metal sheet; 36-second metal sheet; 41-baffle; 42-support rod. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments; the technical features designed in different implementation modes of the present invention described below can be combined with each other as long as they do not conflict with each other; based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In addition, the term "including" and any variation thereof all mean "at least including".

[0029] See also Figures 1 to 6 , Figure 1 This is a structural diagram of a controlled fuse provided by an embodiment of the present utility model. Figure 2 This is an explosion diagram of a controlled fuse provided by an embodiment of the utility model. Figure 3A This is an exploded schematic diagram of a main circuit assembly provided by an embodiment of the present invention. Figure 3B This is a schematic structural diagram of a bracket provided by an embodiment of the present invention. Figure 4 This is a schematic diagram of the structure of the control component 30 provided in one embodiment of the present invention. Figure 5 This is a schematic diagram of the structure of a controlled fuse used between aluminum bars. Figure 6 This is a circuit diagram of a controlled fuse applied to a battery module. Figure 1 The first shell 15 and the second shell are omitted. For the second electrode sheet, the second bracket, the second main circuit alloy, the second seal, and the second shell, please refer to Figure 3A The first electrode sheet 11, the first bracket 12, the first main circuit alloy 13, the first sealing member 14, and the first shell 15 are shown.

[0030] To achieve at least one of the above advantages or other advantages, an embodiment of the present invention provides a controlled fuse. As shown in the figure, the controlled fuse may include a first main circuit component 10, a second main circuit component 20 and a control component 30.

[0031] The first main circuit assembly 10 includes a first electrode sheet 11, a first bracket 12, and a first main circuit alloy 13. The first bracket 12 is mounted on the first electrode sheet 11. The first main circuit alloy 13 is mounted on the first bracket 12 and passes through a through hole on the first bracket 12 to electrically connect to the first electrode sheet 11.

[0032] The second main circuit assembly 20 includes a second electrode sheet, a second bracket, and a second main circuit alloy. The second bracket is mounted on the second electrode sheet, and the second main circuit alloy is mounted on the second bracket and electrically connected to the second electrode sheet through a through hole in the second bracket. The first bracket 12 and the second bracket are insulated.

[0033] The control assembly 30 is disposed between the first main circuit assembly 10 and the second main circuit assembly 20. The control assembly 30 includes a heating element, a control alloy 33, and a lead 34. The control alloy 33 is disposed adjacent to the heating element, which may include a first heating element 31 and a second heating element 32. The first heating element 31 is electrically connected to the second heating element 32, and the control alloy 33 is disposed between the first heating element 31 and the second heating element 32. The lead 34 electrically connects the control alloy 33, the first heating element 31, and the second heating element 32. The first heating element 31 and the second heating element 32 are connected in parallel, and the control alloy 33 is connected in series with the parallel first heating element 31 and the second heating element 32.

[0034] In some embodiments, the first main circuit assembly 10 may further include a first seal 14 and a first housing 15, and the second main circuit assembly 20 may further include a second seal and a second housing. The first seal 14 is arranged between the first electrode sheet 11 and the first bracket 12, and the second seal is arranged between the second electrode sheet and the second bracket. The first housing 15 is arranged on the first electrode sheet 11 and covers the first bracket 12 and the first main circuit alloy 13, and a cavity is formed between the first seal 14 and the first housing 15. The second housing is arranged on the second electrode sheet and covers the second bracket and the second main circuit alloy, and a cavity is formed between the second seal and the second housing. By using the first seal 14 and the second seal as product seals, when the product is disconnected, the high-pressure gas generated can deform the seal to relieve pressure, prevent the shell from rupturing, and achieve a directional pressure relief effect. In some embodiments, the first seal 14 and the second seal are made of soft plastic pads such as silicone pads or polytetrafluoroethylene pads.

[0035] In some embodiments, the control assembly 30 further includes a first metal sheet 35 and a second metal sheet 36, which are located at opposite ends of the first heating element 31. The first metal sheet 35 connects the first heating element 31 and the second heating element 32, and the second metal sheet 36 connects the first heating element 31 and the second heating element 32. The lead 34 passes through the first metal sheet 35. In some embodiments, the material of the first electrode sheet 11 and the second electrode sheet includes aluminum or copper.

[0036] In some embodiments, reference Figure 4 As shown, there are two leads 34 in the figure. The left lead 34 passes through the first metal sheet 35 but does not contact the first metal sheet 35. The end of the left lead 34 contacts the second metal sheet 36. The right lead 34 contacts the first metal sheet 35 and the second metal sheet 36.

[0037] In some embodiments, the number of first main circuit alloys 13 and second main circuit alloys is n, where n ≥ 1, i.e., there are n first main circuit alloys 13 and n second main circuit alloys. Optionally, the number of first main circuit alloys 13 may differ from the number of second main circuit alloys. In some embodiments, the melting point of the first main circuit alloy 13 is lower than the melting point of the control alloy 33, and the melting point of the second main circuit alloy is lower than the melting point of the control alloy 33. This allows the main circuit alloy 104 to fuse first, disconnecting the main circuit of the battery module, and then the control alloy 33 to disconnect and terminate the heating circuit.

[0038] In some embodiments, the first and second brackets 12 are equipped with baffles 41 and support rods 42 disposed between the baffles 41. The number of baffles 41 is n+1, which is one more than the number of first main circuit alloys 13. The first and second main circuit alloys 13 are mounted on the support rods 42 of the first and second brackets, respectively. In some embodiments, the baffles 41 are taller than the first and second main circuit alloys 13 and 42, respectively, to block the confluence of the main circuit alloys and prevent accumulation of the main circuit alloys, which could result in poor disconnection performance.

[0039] The structures of the first main circuit component 10 and the second main circuit component 20 can be the same. Taking the first main circuit component 10 as an example, the cavity in the first main circuit component 10 is sealed by the first seal 14 and the first shell 15. The first seal 14 is locked on the first electrode sheet 11 and then assembled with the first bracket 12. After that, the first main circuit alloy 13 is set on the first bracket 12. The first bracket 12 and the first seal 14 are provided with through holes for the first main circuit alloy 13 to pass through. The first main circuit alloy 13 passes through the through holes on the first bracket 12 and the through holes on the first seal 14 in turn to connect to the first electrode sheet 11. Finally, the first shell 15 is assembled. The first shell 15 and the first bracket 12 can be sealed with resin or a sealing ring. The control component 30 is a control alloy 33 that is welded by two leads 34, one end of which is welded and fixed to the first metal sheet 35, and the other end is used for output. The first heating element 31 and the second heating element 32 are connected in parallel via the first metal sheet 35 and the second metal sheet 36, and the outgoing wires are also welded to the first metal sheet 35. The first metal sheet 35 and the second metal sheet 36 connect the control alloy 33 in series with the parallel first heating element 31 and the second heating element 32. The first metal sheet 35 and the second metal sheet 36 not only secure the lead wire 34 and the heating plate, but also reduce the number of solder joints between the first heating element 31 and the second heating element 32, thereby improving overall stability. The assembled control component 30 is assembled with the first main circuit component 10. The control component 30 is fixed and positioned on the first bracket 12 of the first main circuit component 10 via two heating plates and two metal plates. At the same time, two rivet blocks are assembled at the rivet position. Four rivets are used to connect the first main circuit component 10 and the control component 30. Finally, the second main circuit component 20 is mounted at the rivet position. The rivets are crimped to complete the product, forming a controlled fuse. When the first main circuit assembly 10 and the second main circuit assembly 20 are assembled, the closed space of the control assembly 30 can be assembled. After the controlled fuse is completed, it can be connected to the aluminum bar or copper busbar using rivets or directly welded to the aluminum bar or copper busbar. Figure 5 As shown, the controlled fuse is used to be set between the aluminum bars or copper bars, one end of the aluminum bar or copper bar is connected to the controlled fuse, and the other end is connected to the battery module.

[0040] The active blowing process of the controlled fuse is as follows: after the battery management system BMS determines that blowing is required, the lead 34 receives the signal sent by the BMS, and starts the heating circuit of the product through the loop of the lead 34, so that the first heating element 31 and the second heating element 32 are heated, and the heat is respectively conducted to the first main circuit alloy 13 and the second main circuit alloy through the first electrode sheet 11 and the second electrode sheet. As the heat is conducted, the first main circuit alloy 13 and the second main circuit alloy will be blown first, that is, the main circuit between the aluminum bars will be disconnected, and then the control alloy 33 will be disconnected to avoid continuous heating.

[0041] The passive melting process of the controlled fuse is as follows: when thermal runaway occurs between battery modules, the temperature of the failed battery module rises rapidly, and the first main circuit alloy 13 and the second main circuit alloy are sensitive to temperature. Under the condition of rapid heat transfer between the aluminum bar and the copper busbar, after reaching the set temperature, the first main circuit alloy 13 and the second main circuit alloy can be quickly melted, thereby cutting off the connection between the battery modules to protect the entire battery system.

[0042] In some embodiments, the first main circuit alloy 13 and the second main circuit alloy are M-type or N-type alloys to better withstand the high current and high voltage of the battery module. In the illustrated embodiment, the first main circuit alloy 13 is an M-type alloy, and there are four M-type alloys. It should be noted that the shape of the first bracket 12 is preferably compatible with the shape of the first main circuit alloy 13. For example, if an M-type alloy is used, an M-type bracket is used, and if an N-type alloy is used, an N-type bracket is used. In other embodiments, the shape of the first main circuit alloy 13 can also be a continuous rectangle, trapezoid, or other shape with a bend. The bend of the first main circuit alloy 13 is mounted on the support rod 42 of the first bracket 12, and adjacent first main circuit alloys 13 are separated by a baffle 41. Similarly, the shape of the second bracket is also compatible with the shape of the second main circuit alloy. In some embodiments, the materials of the first main circuit alloy 13 and the second main circuit alloy can be tin-indium alloy, and the control alloy 33 can be tin-bismuth alloy.

[0043] In some embodiments, the first main circuit assembly 10, the second main circuit assembly 20, and the control assembly 30 are each independently prepared. This facilitates production and operation and can also be used to form a controlled fuse suitable for high-current products. Since the battery modules are relatively compactly arranged within the system, the remaining space for installing the controlled fuse is relatively small. Therefore, the volume of the controlled fuse is generally not too large. If a small-volume controlled fuse is to be suitable for high-current and high-voltage products (such as in a 250VDC application scenario), it is relatively difficult. To solve this problem, this embodiment proposes a segmented preparation method, that is, the first main circuit assembly 10, the second main circuit assembly 20, and the control assembly 30 are each independently prepared and then assembled together to form a controlled fuse. In this way, more main circuit alloy can be used in the process of preparing the first main circuit assembly 10 and the second main circuit assembly 20, so that they can be assembled on the control assembly 30. In some embodiments, the first main circuit assembly 10 and the second main circuit assembly 20 are symmetrically arranged relative to the control assembly 30.

[0044] In some embodiments, the surfaces of the first main circuit alloy 13 and the second main circuit alloy can be covered with a flux, which is an organic substance that can help the first main circuit alloy 13 and the second main circuit alloy to shrink and melt quickly. The first shell 15 and the first bracket 12 can be sealed with resin or a sealing ring, and the second shell and the second bracket can be sealed with resin or a sealing ring to improve the sealing performance of the product. The surface of the control alloy 33 can be covered with a flux, and after the first main circuit component 10 and the second main circuit component 20 are assembled in the control component 30, the control alloy 33 has an independent enclosed space. In some embodiments, it is also possible to choose to use a ceramic shell to seal the alloy and directly connect it to the first metal sheet 35 and the second metal sheet 36.

[0045] refer to Figure 6 As shown in the figure, after the relay is opened, if a single battery module experiences dangerous conditions such as abnormal heating, abnormal voltage, and abnormal current, the BMS system starts the MOS tube of the corresponding module, starts the control circuit of the controlled fuse, generates heat to cut off the electrical connection between the modules, and then disconnects the heating circuit to protect the entire battery system.

[0046] In summary, the utility model provides a controlled fuse, which is configured by combining electrode sheets, main circuit alloys, heating elements, control alloys 33 and leads 34, so that the controlled fuse has both active and passive fusing functions. When abnormal temperature, abnormal current or abnormal voltage occurs between battery modules, the BMS detects the signal abnormality and quickly starts the control component 30 through the lead 34, so that the controlled fuse can self-heat and cut off the main circuit, that is, quickly cut off the aluminum bar or copper busbar used for connection between the battery modules, and then melt the heating circuit to protect the entire battery system. When thermal runaway occurs between battery modules, the temperature of the failed battery module rises rapidly, and the main circuit alloy is sensitive to temperature. Under the condition of rapid heat transfer from the aluminum bar and copper busbar, after reaching the set temperature, it can quickly melt and cut off the connection between the battery modules to protect the entire battery system.

[0047] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the present invention may be improved in only one or several aspects, without having to solve all the technical problems listed in the prior art or background art at the same time. Those skilled in the art should understand that the absence of any content in a claim should not be construed as a limitation on that claim.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A controlled fuse, characterized in that: The controlled fuse includes: a first main circuit assembly, the first main circuit assembly comprising a first electrode sheet, a first bracket, and a first main circuit alloy, the first bracket being mounted on the first electrode sheet, the first main circuit alloy being mounted on the first bracket and electrically connected to the first electrode sheet; a second main circuit assembly, the second main circuit assembly comprising a second electrode sheet, a second bracket, and a second main circuit alloy, the second bracket being mounted on the second electrode sheet, the second main circuit alloy being mounted on the second bracket and electrically connected to the second electrode sheet; A control component is arranged between the first main circuit component and the second main circuit component. The control component includes a heating element, a control alloy and a lead. The control alloy is arranged adjacent to the heating element, and the lead electrically connects the control alloy and the heating element.

2. The controlled fuse according to claim 1, characterized in that: The first main circuit assembly further includes a first sealant, and the second main circuit assembly further includes a second sealant. The first sealant is disposed between the first electrode sheet and the first bracket, and the second sealant is disposed between the second electrode sheet and the second bracket.

3. The controlled fuse according to claim 2, characterized in that: The first main circuit component also includes a first shell, and the second main circuit component also includes a second shell. The first shell is arranged on the first electrode sheet and covers the first bracket and the first main circuit alloy, and a cavity is formed between the first seal and the first shell. The second shell is arranged on the second electrode sheet and covers the second bracket and the second main circuit alloy, and a cavity is formed between the second seal and the second shell.

4. The controlled fuse according to claim 1, characterized in that: The number of the first main circuit alloy and the second main circuit alloy is n, where n≥1, and the first main circuit alloy and the second main circuit alloy are M-type alloy or N-type alloy.

5. The controlled fuse according to claim 4, characterized in that: The first bracket and the second bracket are provided with baffles and support rods arranged between the two baffles. The number of the baffles is n+1. The first main circuit alloy and the second main circuit alloy are respectively mounted on the support rods of the first bracket and the second bracket.

6. The controlled fuse according to claim 1, characterized in that: The height of the baffle is higher than that of the first main circuit alloy, and the height of the baffle is higher than that of the second main circuit alloy.

7. The controlled fuse according to claim 1, characterized in that: The melting point of the first main circuit alloy is lower than the melting point of the control alloy, and the melting point of the second main circuit alloy is lower than the melting point of the control alloy.

8. The controlled fuse according to claim 1, characterized in that: The heating element includes a first heating element and a second heating element, and the control component also includes a first metal sheet and a second metal sheet. The first metal sheet and the second metal sheet are located at opposite ends of the first heating element. The first metal sheet connects the first heating element and the second heating element, and the second metal sheet connects the first heating element and the second heating element. The lead passes through the first metal sheet.

9. The controlled fuse according to claim 1, characterized in that: The surface of the control alloy is coated with a flux.

10. The controlled fuse according to claim 1, characterized in that: The first main circuit assembly, the second main circuit assembly and the control assembly are connected by rivets.

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