Fuse assembly and battery pack

Abstract

The disclosure provides a fuse assembly and a battery pack, and relates to the technical field of batteries, wherein the fuse assembly comprises a base, a fuse, a heat-conducting structural adhesive, and a glue-blocking structure. The base is provided with a fuse-carrying groove and a heat-protection fence. The fuse is installed in the fuse-carrying groove and inside the heat-protection fence, and the height of the fuse heating top surface is lower than the height of the heat-protection fence. The heat-conducting structural adhesive is arranged between the contact surface of the fuse and the fuse-carrying groove, and is used for realizing the adhesive fixing and heat conduction of the fuse and the base. The glue-blocking structure is arranged on at least one side of the base, and is used for limiting the flow range of the heat-conducting structural adhesive. The fuse assembly constructs a four-element collaborative reliability system of heat-conducting structural adhesive-fuse-carrying groove-glue-blocking structure-heat-protection fence, and has the effects of high heat dissipation performance, reliable fixing, glue overflow prevention, and effective heat protection.

Description

Technical Field

[0001] This disclosure belongs to the field of battery technology, specifically relating to a fuse assembly and a battery pack. Background Technology

[0002] Current new energy battery packs are continuously iterating towards high integration and high power density, with compact internal component arrangement and minimal space margin. Under high-voltage, high-current operating conditions, the fuses in these battery packs operate at consistently high temperatures.

[0003] Related technologies primarily achieve miniaturization by optimizing the fuse body structure and mechanically fixing it to the base using bolts or clips. However, this fixing method has the following inherent drawbacks: 1) Poor heat dissipation performance: There is an unavoidable assembly gap between the fuse housing and the base. The thermal conductivity of air is extremely low, which means that the heat generated by the fuse during operation cannot be quickly conducted to the base and tray for heat dissipation. Excessive temperature rise and long-term high-temperature operation will accelerate the aging of the fuse body and the carbonization of the plastic housing, resulting in a decrease in the accuracy of the fuse and a shortened service life.

[0004] 2) Low reliability of fastening: Under the conditions of vehicle bumps and battery pack vibration, the buckle is prone to elastic fatigue or loosening, which leads to increased contact resistance and may even cause local sparking, resulting in electrical failure.

[0005] 3) Lack of thermal protection: The side of the base is flush with the bottom of the fuse, without any heightened protection design. This cannot effectively block the heat radiation generated when the fuse is operating at high current, which leads to accelerated aging of surrounding copper busbars, wiring harnesses and sensors, reducing the service life and operational stability of components in the battery pack.

[0006] Replacing the bolts or clips in the above solution with thermally conductive structural adhesive can improve heat dissipation, but the fluid thermally conductive adhesive will overflow unrestricted to both sides of the base, directly adhering to the surrounding conductive copper busbars and creating a short circuit risk. If the fuse fails, the fuse, base, and copper busbars must be replaced simultaneously, which is too costly. Summary of the Invention

[0007] This disclosure provides a fuse assembly and a battery pack, which aims to at least partially solve the technical problems of poor heat dissipation, low fixing reliability and lack of thermal protection of fuses while achieving miniaturization design.

[0008] At least one embodiment of this disclosure provides a fuse assembly, comprising: a base having a fuse-bearing groove and a thermal protection barrier; a fuse mounted in the fuse-bearing groove and located inside the thermal protection barrier, wherein the height of the fuse wire heating top surface is lower than the height of the thermal protection barrier; a thermally conductive structural adhesive disposed between the contact surfaces of the fuse and the fuse-bearing groove, for bonding and fixing the fuse to the base and for heat conduction; and an adhesive-blocking structure disposed on at least one side of the base for restricting the flow range of the thermally conductive structural adhesive.

[0009] The above solution offers the following technical advantages: Addressing the limitations of existing technologies in simultaneously resolving the issues of poor heat dissipation, low fixation reliability, and lack of thermal protection in fuses while achieving miniaturization, this solution proposes an integrated and highly reliable axially compact fuse assembly with enhanced heat dissipation. This fuse assembly employs a component-coordinated reliability enhancement mechanism, constructing a four-element coordinated reliability system comprising thermally conductive structural adhesive, fuse bearing groove, adhesive-blocking structure, and thermal protection enclosure. Specifically, the fuse assembly uses thermally conductive structural adhesive as the connection medium between the fuse and the base, achieving both structural bonding and efficient heat dissipation. The fluidity of the thermally conductive structural adhesive effectively eliminates air gaps during assembly, optimizing heat dissipation. Ultimately, the thermally conductive structural adhesive ensures good adhesion and thermal conductivity between the fuse and the base. The fuse bearing groove in this fuse assembly serves to guide the adhesive and anchor the interface. This fuse assembly addresses the issues of adhesive overflow, copper busbar adhesion, and short-circuit leakage caused by the adhesive bonding process by adding an adhesive-blocking structure to the base. This allows the adhesive heat dissipation bonding process to be mass-produced, balancing heat dissipation performance and electrical safety. Ultimately, the adhesive-blocking structure achieves sealing, heat insulation, and anti-creep effects. The fuse assembly also features a thermal protection enclosure on the base, higher than the fuse wire's heating surface. This reduces the overall footprint and achieves a compact design while providing effective physical protection and thermal isolation for the fuse, offering macroscopic thermal shielding and structural protection. Compared to single-factor improvements, such as simply replacing the thermally conductive adhesive or increasing the sidewall height, the quaternary synergistic reliability system ensures that the fuse maintains a contact resistance drift rate below 0.8% in comprehensive operating condition tests conducted according to GB / T31467.3-2015 standards, including vibration, 85°C high temperature, and 95% relative humidity, and extends the thermal runaway trigger time to no less than 120 seconds. Therefore, the system-level robustness of this fuse assembly cannot be achieved by simply adding the performance of individual components. Compared with related technologies, this fuse assembly has high heat dissipation performance, reliable fixing, anti-overflow adhesive and effective thermal protection, and achieves the goals of reducing overall weight, simplifying assembly and manufacturing process.

[0010] At least one embodiment of the present disclosure provides a fuse assembly that further includes: a copper busbar disposed axially on the fuse and located on the side of the adhesive-blocking structure opposite to the fuse, wherein one end of the copper busbar is electrically connected to the fuse and the other end of the copper busbar is used for electrical connection to an external circuit; and a copper busbar fastener for fixing the copper busbar to the fuse.

[0011] The above solution has the following technical effects: it increases the copper busbar for stable connection, enabling the fuse assembly to have complete circuit functions.

[0012] At least one embodiment of the present disclosure provides a fuse assembly that further includes a base fastener for securing the base to a preset mounting point on an external battery pack tray.

[0013] The above solution has the following technical effects: it improves the connection between the fuse assembly and the external battery pack tray to resist bumps and vibrations and prevent electrical faults caused by displacement.

[0014] In at least one embodiment of the fuse assembly provided in this disclosure, the bottom end face of the fuse bearing groove is provided with a mesh structure, the mesh structure being used to guide the distribution of the thermally conductive structural adhesive, so that the thermally conductive structural adhesive is evenly distributed in the gap between the bottom end face of the fuse and the bottom end face of the fuse bearing groove.

[0015] The above solution has the following technical effects: the bottom structure of the fuse bearing groove has been optimized, aiming to improve the filling effect and connection strength of the thermally conductive structural adhesive.

[0016] In at least one embodiment of the fuse assembly provided in this disclosure, the bottom end face of the fuse bearing groove is provided with a thermally conductive metal layer, which extends to the external mounting hole of the base and serves as the main heat flow channel of the fuse assembly to form a three-level heat dissipation chain in which the fuse, the thermally conductive structural adhesive and the base conduct heat in sequence.

[0017] The above solution has the following technical effects: it introduces a thermally conductive metal layer and designs the heat conduction path in a directional manner, which significantly enhances the heat dissipation capacity.

[0018] In at least one embodiment of the fuse assembly provided in this disclosure, the base is integrally injection molded from insulating and flame-retardant plastic; and the surrounding sidewalls of the base form the thermal protection enclosure, the height of which exceeds the height of the fuse wire heating top surface by 5-10 mm, so that the thermal protection enclosure surrounds the fuse.

[0019] The above solution has the following technical advantages: it limits the material of the base and the specific dimensions of the thermal protection enclosure, which is key to achieving a compact and safe design.

[0020] In at least one embodiment of the fuse assembly provided in this disclosure, the base is provided with vertical reinforcing ribs on its four sides to prevent the thermal protection barrier from failing due to heat.

[0021] The above solution has the following technical effect: it enhances the structural stability of the base.

[0022] In at least one embodiment of the fuse assembly provided in this disclosure, the four sides of the base are provided with a gradient porosity structure, the porosity of the gradient porosity structure gradually changes from a first porosity at the bottom to a second porosity at the top, so as to construct a thermal barrier wall and force heat to be conducted to the bottom of the base; wherein, the first porosity is less than the second porosity.

[0023] The above solution has the following technical effects: the internal structure of the base sidewall has been innovatively designed to optimize the thermal management performance of the fuse assembly.

[0024] In at least one embodiment of the fuse assembly provided in this disclosure, the adhesive-blocking structure includes vertical adhesive-blocking strips made of elastic buffer material and symmetrically arranged on both sides of the axial direction of the base. The vertical height of the adhesive-blocking structure is higher than the adhesive layer thickness at each point in the fuse-bearing groove, and it protrudes laterally 3-5 mm beyond the edge of the fuse-bearing groove to form a closed, limiting adhesive-blocking area that prevents excess thermally conductive structural adhesive overflowing from the fuse-bearing groove from contacting the copper busbar. The thermally conductive structural adhesive has a thermal conductivity ≥3.5 W / m·K, a peel strength ≥8 N / mm, a shear strength ≥25 MPa, a coating amount of (0.32±0.03) g / cm², and a corresponding adhesive layer thickness of 800-1000 μm. The mesh structure is a cross-shaped mesh groove structure with a groove depth of 0.6-0.8 mm, a mesh line width of 1.4-1.6 mm, and a mesh spacing of 2.8-3.2 mm.

[0025] The above solution has the following technical effects: by specifying multiple parameters, it aims to achieve mass production and ensure high performance by addressing core constraints.

[0026] At least one embodiment of this disclosure also provides a battery pack, including a battery pack body, a battery pack tray for mounting the battery pack body, and a fuse assembly as provided in any embodiment of this disclosure, the fuse assembly being fixed to the battery pack tray and used for electrical connection with the external circuit.

[0027] The above solution has the following technical effects: Since the fuse itself has advantages such as enhanced heat dissipation, axial compactness, reliable fixation and excellent thermal protection, integrating it into the battery pack can directly improve the safety, power density, reliability and service life of the entire battery pack.

[0028] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 A schematic diagram of the structure of a fuse assembly provided for at least one embodiment of this disclosure; Figure 2 for Figure 1 Schematic diagram of the internal structure of the fuse assembly; Figure 3 A schematic diagram of the structure of a base example 1 provided in at least one embodiment of this disclosure; Figure 4 A top view of a base example 1 provided for at least one embodiment of this disclosure; Figure 5 This is a schematic diagram of the structure of Example 2 of the base provided in at least one embodiment of the present disclosure; Figure 6 A top view of a second example of a base provided for at least one embodiment of this disclosure; Figure 7 A schematic diagram of another fuse assembly provided for at least one embodiment of this disclosure; Figure 8 This is a schematic diagram of the composition of another fuse assembly provided for at least one embodiment of the present disclosure.

[0031] Figure label: 1- Base; 2- Fuse; 3- Thermally conductive structural adhesive; 4- Adhesive-blocking structure; 5- Copper busbar; 6- Copper busbar fastener; 7- Base fastener; 11- Fuse bearing groove; 12- Thermal protection enclosure; 13- Thermally conductive metal layer; 14- Vertical reinforcing rib; 111- Grid structure. Detailed Implementation

[0032] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the disclosure. Similarly, the following embodiments are only some, not all, embodiments of the present disclosure, and all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this disclosure.

[0033] The terms "first," "second," and "third" used in the embodiments of this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first," "second," and "third" may explicitly or implicitly include at least one of that feature.

[0034] In the description of this disclosure, "multiple" means at least two, such as two or three, unless otherwise expressly and specifically limited.

[0035] In this disclosure, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0036] The terms “comprising” and “having”, and any variations thereof, used in this disclosure are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or components inherent to such processes, methods, products, or devices.

[0037] In this disclosure, the term "fuse" refers to a core protection device in the high-voltage circuit of the battery pack, which is connected in series in the high-voltage circuit of the battery. When a short circuit or overload fault occurs in the circuit, it breaks the circuit by melting its own fuse element to prevent the battery module and electronic control device from burning out and to ensure the overall electrical safety of the battery pack.

[0038] The term "thermal conductive structural adhesive" in this disclosure refers to a special adhesive that combines structural bonding strength with high thermal conductivity. It can bond and fix components, while rapidly conducting the working heat of the device. It has the characteristics of insulation, shock resistance, resistance to high and low temperatures and resistance to aging, and is suitable for the sealed working environment of battery packs.

[0039] In the embodiments of this disclosure, the term "axial" refers to the direction extending along the central axis of the fuse itself.

[0040] In this embodiment of the disclosure, the term "fuse heating top surface" refers to the top surface of the fuse, where Joule heating is generated due to the current during the operation of the fuse. This surface is where the heat is most concentrated and faces the external heat conduction and dissipation structure, and is the core area where the fuse dissipates heat when it is working.

[0041] The term "DOE test" in this disclosure refers to a mathematical statistical test method that obtains clear test conclusions with a small sample size by reasonably and orderly arranging set parameters. It can be used to analyze the degree of influence of different structural parameters on the performance of the fuse assembly and to help determine the optimal structural design scheme.

[0042] To address the limitations of existing technologies in simultaneously resolving the technical problems of poor heat dissipation, low fixation reliability, and lack of thermal protection in fuses while achieving miniaturization, this disclosure proposes an integrated and highly reliable axially compact fuse assembly with enhanced heat dissipation. The fuse assembly of this disclosure employs a component-coordinated reliability enhancement mechanism, constructing a four-element coordinated reliability system comprising thermally conductive structural adhesive, fuse bearing groove, adhesive-blocking structure, and thermal protection enclosure. Specifically, the fuse assembly uses thermally conductive structural adhesive as the connecting medium between the fuse and the base, achieving both structural bonding and efficient heat dissipation. The fluidity of the thermally conductive structural adhesive effectively eliminates assembly air gaps, optimizing heat dissipation. Ultimately, the thermally conductive structural adhesive ensures good adhesion and thermal conduction between the fuse and the base. The fuse bearing groove in this fuse assembly serves to guide the adhesive and anchor the interface. This disclosed fuse assembly addresses the issues of adhesive overflow, copper busbar adhesion, and short-circuit leakage caused by adhesive bonding processes by adding an adhesive-blocking structure to the base. This allows for mass production of the adhesive heat-dissipating bonding process, balancing heat dissipation performance and electrical safety. Ultimately, the adhesive-blocking structure achieves sealing, heat insulation, and anti-creep effects. The fuse assembly, through a thermal protection enclosure on the base, with its height exceeding the heating surface of the fuse wire, provides effective physical protection and thermal isolation space for the fuse while reducing overall space requirements and achieving a compact design. It also provides macroscopic thermal shielding and structural protection. Compared to single-factor improvements, such as simply replacing the thermally conductive structural adhesive or increasing the sidewall height, the quaternary synergistic reliability system ensures that the contact resistance drift rate remains below 0.8% in comprehensive operating condition tests conducted according to GB / T31467.3-2015 standards, including vibration, 85℃ high temperature, and 95% relative humidity, and that the thermal runaway trigger time is extended to no less than 120 seconds. Therefore, the fuse assembly disclosed herein has the effects of high heat dissipation performance, reliable fixing, anti-overflow adhesive and effective thermal protection, and achieves the purpose of reducing the weight of the whole machine, simplifying assembly and manufacturing process.

[0043] Based on this, the fuse assembly disclosed herein further adds base fasteners, copper busbars and copper busbar fasteners, and makes a series of improvements to the base, thermally conductive structural adhesive and adhesive blocking structure. The overall design adopts a compact design with adhesive + bolt fixing, anti-overflow adhesive limit, increased thermal protection and recessed base installation, which further improves the overall structural stability, heat dissipation efficiency and electrical safety margin of the fuse, and extends the overall service life of the product.

[0044] Figure 1 This is a schematic diagram of a fuse assembly provided for at least one embodiment of the present disclosure. This fuse assembly can be used in battery packs, particularly for overload and short-circuit protection of highly integrated, high-power-density power battery packs. Figure 1 As shown, the fuse assembly includes a base 1, a fuse 2, a thermally conductive structural adhesive 3, and an adhesive-blocking structure 4.

[0045] The base 1 is provided with a fuse bearing groove 11 ( Figure 1 Not shown in the image, see [link / reference]. Figure 3 ) and thermal protection fencing 12.

[0046] The fuse 2 is installed in the fuse bearing groove 11 and is located inside the thermal protection enclosure 12, and the height of the heating top surface of its fuse wire is lower than the height of the thermal protection enclosure 12.

[0047] Thermally conductive structural adhesive 3 is placed between the contact surfaces of the fuse 2 and the fuse bearing groove 11, and is used to achieve bonding and fixing of the fuse 2 and the base 1 and heat conduction.

[0048] The adhesive barrier structure 4 is disposed on at least one side of the base 1, which is used to limit the flow range of the thermally conductive structural adhesive 3.

[0049] The above solution, through the coordinated design of base 1, fuse 2, thermally conductive structural adhesive 3, and adhesive-blocking structure 4, constructs an integrated and highly reliable fuse assembly. The internal structure of this fuse assembly is as follows: Figure 2 As shown. The fuse-bearing groove 11 on the base 1 provides the mounting and positioning foundation for the fuse 2, while the thermal protection enclosure 12 provides physical protection and thermal isolation space for the fuse 2. The fuse 2 is installed in the fuse-bearing groove 11 and is completely under the protection of the thermal protection enclosure 12, with its fuse wire heating top surface lower than the height of the thermal protection enclosure 12, which constitutes the geometric basis for achieving effective thermal protection. The thermally conductive structural adhesive 3 between the fuse and the bearing groove replaces the traditional mechanical connection method, achieving both structural bonding and efficient heat conduction, and eliminating the thermal resistance caused by air gaps. The adhesive-blocking structure 4 restricts the flow range of the thermally conductive structural adhesive 3 during application, preventing the adhesive from overflowing and contaminating surrounding electrical components, ensuring cleanliness and safety during assembly.

[0050] Some embodiments of this disclosure also provide a battery pack corresponding to the above-described fuse assembly.

[0051] At least one embodiment of this disclosure provides a fuse assembly suitable for any existing application scenario where the fuse operates under high voltage and high current conditions and is constantly under high temperature. For example, in high-voltage power battery packs of new energy vehicles, the operating voltage of the power battery system typically reaches 300-800V, and the peak operating current can exceed several thousand amperes. As a core component for circuit overcurrent protection, the fuse needs to withstand the continuous temperature rise caused by the high current for a long time, placing extremely high demands on heat dissipation efficiency and structural stability. In addition, in high-voltage energy storage battery clusters of large-scale energy storage power stations, multiple large-capacity batteries are connected in series and parallel to form an energy storage system. The fuse operates in a closed and high-temperature battery compartment environment for a long time. It not only needs to quickly dissipate the heat generated during its operation to avoid overheating and aging failure, but also needs to prevent the overflow of adhesive during assembly from contaminating surrounding busbars and battery management units, and other precision electrical components. The fuse assembly of this disclosure perfectly matches the needs of these application scenarios. It eliminates contact thermal resistance through thermally conductive structural adhesive, achieving efficient temperature control, and ensures assembly cleanliness and electrical safety through an adhesive-blocking structure. This effectively extends the service life of the fuse and improves the operational reliability of the entire high-voltage circuit system.

[0052] In some embodiments, Figure 1 Based on the proposed design, to achieve a compact and safe design for the base 1, it is integrally injection molded from insulating and flame-retardant plastic. Furthermore, thermal protection barriers 12 are formed around the four sides of the base 1. The height of the thermal protection barriers 12 exceeds the height of the fuse wire's heating surface by 5-10 mm, ensuring that the thermal protection barriers 12 completely surround the fuse 2. The integral injection molding of insulating and flame-retardant plastic guarantees the electrical insulation, fire safety, and structural strength of the base, while also facilitating mass production. The 5-10 mm difference in height between the thermal protection barriers 12 and the fuse wire's heating surface is a precisely verified optimal range. Within this range, according to the law of thermal radiation, this height is sufficient to block more than 87% of the direct radiation from the fuse's heating surface, effectively protecting the surrounding copper busbar insulation layer and sensor, preventing them from aging or becoming inaccurate due to high temperatures. Exceeding this upper limit (10 mm) would result in an excessive base width, causing assembly interference, and the marginal effect of improving heat dissipation and structural strength would diminish. This design achieves complete enclosure of the fuse and optimal thermal shielding of surrounding devices within a limited space, which is a necessary condition for highly integrated battery pack design.

[0053] In the above scheme, the lower limit of the height deviation range between the height of the thermal protection enclosure 12 and the height of the fuse 2's heating top surface is set at 5mm, based on the Stefan-Boltzmann law. When the temperature of the fuse's heating top surface is 120℃, its radiated power density to the surrounding environment is 1.2kW / m². When the height deviation between the thermal protection enclosure 12 and the fuse 2's heating top surface is not less than 5mm, it can achieve the blocking of more than 87% of direct radiation, that is, the geometric shielding angle is greater than 78°, thereby reducing the radiated heat flux density on the copper busbar surface to below 150W / m². Raising the sidewall provides macroscopic thermal shielding and structural protection.

[0054] The upper limit of the height deviation range between the height of the thermal protection enclosure 12 and the height of the fuse heating top surface of the fuse 2 is set at 10mm. This threshold is the balance point between structural rigidity and spatial constraints. If the height deviation between the height of the thermal protection enclosure 12 and the height of the fuse heating top surface of the fuse 2 is greater than 10mm, the bending stiffness of the thermal protection enclosure 12 (base sidewall) will decrease due to the saturation of the moment of inertia, and the weight will increase, which violates the principle of lightweight design. More importantly, the value of 10mm is the sum of the maximum height tolerance of the fuse thermal protection housing as a standard part, ±1.5mm, the installation gap of 1mm, and the safety margin of 1mm.

[0055] If the height deviation between the thermal protection enclosure 12 and the heating top surface of the fuse 2 is less than 5mm, it will cause the thermal radiation shielding to fail, leading to accelerated aging of the copper busbar insulation layer. Additionally, insufficient high-voltage creepage distance can easily cause leakage current to exceed limits in humid and hot environments. If the height deviation between the thermal protection enclosure 12 and the heating top surface of the fuse 2 exceeds 10mm, the base 1 will exceed the pre-reserved mounting frame of the battery pack tray, causing assembly interference. Furthermore, uneven shrinkage during the injection molding process will cause the thermal protection enclosure 12 to warp by more than 0.15mm, affecting sealing performance and reducing production yield.

[0056] To further verify the effectiveness of the above parameter settings, the parameters were quantitatively verified, and three rounds of accelerated life tests were completed, each lasting 42 hours. In the experimental group where the height deviation between the thermal protection enclosure 12 and the height of the fuse 2's heating top surface was 8 mm, the decay rate of the insulation resistance of the surrounding copper busbar was 0.12 MΩ / h. This performance was significantly better than the first control group (0.41 MΩ / h) where the height deviation between the thermal protection enclosure 12 and the fuse 2's heating top surface was 5 mm, and the second control group (0.15 MΩ / h) where the height deviation was 10 mm.

[0057] In some embodiments, Figure 1Based on the existing design, to further optimize the thermal management performance of base 1, a gradient porosity structure is provided on the four side walls of base 1. The porosity of this gradient porosity structure gradually changes from a first porosity at the bottom to a second porosity at the top, with the first porosity being less than the second porosity. This creates a thermal barrier wall to force heat conduction to the bottom of base 1. In particular, this design innovatively incorporates an internal structure for the side walls of base 1. The porosity of the side walls gradually increases from bottom to top. Utilizing the low thermal conductivity of air, this structure effectively creates a thermal barrier wall within the side walls, increasing the resistance to lateral heat diffusion to the top and outside of the side walls. This forces heat to be more concentratedly conducted to the heat conduction path at the bottom of base 1, thereby further improving the efficiency of the entire heat dissipation system.

[0058] As an exemplary implementation, the first porosity is 30%, and the second porosity is 70%. The porosity gradually changes from 30% at the bottom to 70% at the top, which allows for the artificial construction of a thermal barrier wall while ensuring structural strength, thereby forcing heat to be conducted to the bottom-tray path of the base 1. Through the above structural improvement, the internal heat path orientation design of the base 1 is achieved, and the base adopts a heterogeneous structural design.

[0059] In some embodiments, Figure 1 Based on the proposed solution, to ensure thermal conductivity and avoid the risk of adhesive overflow, the thermally conductive structural adhesive 3 has a thermal conductivity ≥3.5 W / m·K, peel strength ≥8 N / mm, shear strength ≥25 MPa, a coating amount of (0.32±0.03) g / cm², and a corresponding adhesive layer thickness of 800~1000 μm. The thermal conductivity ≥3.5 W / m·K, peel strength ≥8 N / mm, and shear strength ≥25 MPa of the thermally conductive structural adhesive 3 ensure that the adhesive possesses both highly efficient thermal conductivity and extremely high structural strength, enabling it to firmly lock the fuse under vehicle vibration. The coating amount of (0.32±0.03) g / cm² and the adhesive layer thickness of 800~1000 μm are standards for ensuring thermal conductivity and avoiding the risk of adhesive overflow. Too little adhesive will create voids, while too much will easily overflow.

[0060] As an exemplary implementation, the thermally conductive structural adhesive 3 can be a two-component epoxy-based thermally conductive structural adhesive. This two-component epoxy-based thermally conductive structural adhesive has high thermal conductivity (≥3.5W / m·K), high shear strength (≥25MPa), high peel strength (≥8N / mm), wide temperature range (long-term stability from -40℃ to 200℃), and a UL94 V-0 flame retardant rating, meeting the requirements of the battery pack's sealed, high-humidity, and vibration environments. Initial curing is performed at 25℃ for 30 minutes, and complete curing is achieved at 80℃ for 60 minutes or 25℃ for 72 hours, employing a two-stage strategy of low-temperature initial curing followed by high-temperature final curing: initial curing ensures production line cycle time (≤3 minutes for assembly), while final curing releases internal stress and achieves final performance. Relying solely on room temperature curing would not meet mass production cycle time; forcing high-temperature rapid curing (>120℃) could damage the molten metal and insulating materials inside the fuse 2. This process window is a key constraint for the mass production feasibility of this solution.

[0061] Based on the projected area of ​​the fuse bearing groove 11, the coating amount quantitative standard was set to (0.32±0.03) g / cm². DOE testing determined that when the coating amount was below the lower limit of the coating amount quantitative standard (0.29 g / cm²), the adhesive layer was discontinuous, with micropores, and the thermal resistance increased by 23%. When the coating amount was above the upper limit of the coating amount quantitative standard (0.35 g / cm²), the risk of adhesive overflow increased sharply, and the failure probability of the thermally conductive structural adhesive 3 rose from 0.3% to 12%. This value corresponds to an adhesive layer thickness of approximately 800~1000 μm, which precisely fills the microstructure of the fuse bearing groove 11, achieving self-limiting adhesive amount.

[0062] Using shear strength (characterized by dynamic shear modulus G) as a material selection criterion is for design adaptation to vibration levels. The glass transition temperature of the thermally conductive structural adhesive 3 is designed within the 10–500 Hz frequency range. T g = (115±5)℃, ensuring that it remains in a highly elastic state at the highest operating temperature of the battery pack, providing damping buffer; adding nano-silica thixotropic agent, so that the thermally conductive structural adhesive 3 maintains its shape under static conditions and shears and thins at the moment of pressing, ensuring uniform spreading.

[0063] In some embodiments, Figure 1Based on the proposed solution, to ensure good sealing, heat insulation, and adhesive overflow interception, the adhesive-blocking structure 4 includes vertical adhesive-blocking strips made of elastic buffer material, symmetrically arranged on both sides of the axial direction of the base 1. The vertical height of the adhesive-blocking structure 4 is higher than the adhesive layer thickness at each point in the fuse-bearing groove 11, and its lateral protrusion 3-5mm beyond the edge of the fuse-bearing groove 11 forms a closed, limiting adhesive-blocking area to prevent excess thermally conductive structural adhesive 3 from overflowing from the fuse-bearing groove 11 and contacting the copper busbar 5. The vertical adhesive-blocking strips, while restricting adhesive flow, also provide cushioning, vibration damping, and a certain degree of heat insulation. The height of the adhesive-blocking strips is higher than the thickness of all adhesive layers to ensure complete blocking; its lateral protrusion 3-5mm beyond the groove edge is a verified preferred value. A value less than 3mm may result in incomplete adhesive overflow interception, while a value greater than 5mm may cause the overall size of the base to exceed the specifications, affecting the compact design.

[0064] In the above scheme, the adhesive barrier structure 4 has good dynamic sealing, heat insulation and anti-creep properties.

[0065] As an exemplary implementation, the adhesive-blocking structure 4 is made of EPDM foam material, with a Shore A hardness of 35±3 and a density of (0.28±0.02) g / cm³. It is a soft foam that provides thermal insulation and vibration damping when the fuse operates at high temperatures. When the fuse wire of the fuse 2 reaches high temperatures, the surface temperature rise of the copper busbar 5 on the outer side of the adhesive-blocking structure 4 is lower than that of rigid plastic, thus providing good thermal insulation. The EPDM foam material provides stroke buffering under vertical vibration and absorbs high-frequency impact energy, thus providing good cushioning and shock resistance. Its microporous structure can absorb trace amounts of excess adhesive, preventing the adhesive from creeping along the copper busbar, thus providing good sealing compatibility. The optimal protrusion of 3-5mm is determined by a combination of DOE testing and FEA simulation: 3mm is the minimum effective value, at which point the adhesive barrier structure 4 can completely cover the maximum lateral diffusion radius of the adhesive (2.8mm), with an overflow interception rate ≥99.1%; 5mm is the maximum economical value. Increasing it further would cause the width of the base 1 to exceed the standard, violating the compact design constraints, and increasing the compression and rebound hysteresis of the EPDM foam material, affecting the assembly feel. The adhesive barrier structure 4 always provides rigid restraint and elastic containment for the thermally conductive structural adhesive 3, avoiding hard contact that could cause the thermally conductive structural adhesive 3 to tear or the adhesive barrier structure 4 to deform.

[0066] Figure 3 A schematic diagram of the structure of a base example 1 provided for at least one embodiment of this disclosure. Figure 4 A top view of an example of a base provided for at least one embodiment of this disclosure. Figure 1 Based on the proposed solution, a targeted design was implemented for the heat conduction path of the fuse assembly to enhance heat dissipation capabilities, such as... Figure 3As shown, a thermally conductive metal layer 13 is provided on the bottom end face of the fuse-supporting groove 11. The thermally conductive metal layer 13 extends to the external mounting hole of the base 1, serving as the main heat flow channel of the fuse assembly, forming a three-stage heat dissipation chain where the fuse 2, thermally conductive structural adhesive 3, and base 1 conduct heat sequentially. This design introduces the thermally conductive metal layer 13 and positions it at the bottom of the fuse-supporting groove 11 as the main heat flow channel. The thermally conductive metal layer 13, together with the fuse 2 and thermally conductive structural adhesive 3, constructs a three-stage heat dissipation chain from fuse 2 to thermally conductive structural adhesive 3 to base 1, further conducting heat to the external battery pack tray. Heat is efficiently conducted from the fuse 2, quickly transferred to the external battery pack tray via the thermally conductive metal layer 13, and finally dissipated over a large area through the battery pack tray. This design forces heat to conduct to the bottom of the base 1, preventing heat accumulation inside the base 1.

[0067] In some embodiments, Figure 3 and Figure 4 Based on the design, the thermally conductive metal layer 13 is made of copper foil. The thermally conductive metal layer 13 with perforated copper foil (thickness greater than the set value) is embedded in the bottom of the fuse bearing groove 11 as the main heat flow channel and to ensure the bonding effect; the edge of the copper foil extends to the four corner bolt mounting holes of the base to form a heat sink.

[0068] In some embodiments, such as Figure 3 and Figure 4 As shown, to increase the contact area, a mesh structure 111 is provided on the bottom end face of the fuse-supporting groove 11. The mesh structure 111 guides the distribution of the thermally conductive structural adhesive 3, so that the thermally conductive structural adhesive 3 is evenly distributed in the gap between the bottom end face of the fuse 2 and the bottom end face of the fuse-supporting groove 11. The bottom structure of the fuse-supporting groove 11 has been optimized to improve the filling effect and connection strength of the thermally conductive structural adhesive 3. During the pressing assembly of the fuse 2, air can be effectively expelled, while the thermally conductive structural adhesive 3 can be evenly filled into each mesh, forming a continuous and bubble-free thermally conductive layer. This design not only increases the contact area between the fuse 2 and the base 1, improving heat conduction efficiency, but also enhances the bonding strength through mechanical interlocking, further improving the reliability of the fuse assembly under vibration.

[0069] In some embodiments, Figure 3 and Figure 4Based on the design, the mesh structure 111 is equipped with mesh reinforcing ribs. These ribs are positioned along the edges of each groove unit, dividing each groove unit into an independent adhesive storage space. This enhances the structural rigidity of the bottom area of ​​the fuse-bearing groove 11, preventing warping and deformation during fuse assembly and ensuring uniform adhesive thickness. Furthermore, it further restricts the positional displacement of the cured thermally conductive adhesive 3, forming a multi-dimensional mechanical interlocking structure with the mesh structure 111. Under large temperature differences, this buffers the internal stress caused by thermal expansion and contraction of the thermally conductive adhesive 3, reducing the risk of adhesive detachment and cracking, and further improving the overall structural reliability and thermal stability of the fuse assembly.

[0070] In some embodiments, such as Figure 3 and Figure 4 As shown, the mesh structure 111 is a cross-shaped groove structure with a groove depth of 0.6~0.8mm, a mesh line width of 1.4~1.6mm, and a mesh spacing of 2.8~3.2mm. This specific mesh structure guides the thermally conductive structural adhesive 3 to flow and fill quickly and evenly. Simultaneously, the rib structure can be embedded in the thermally conductive structural adhesive 3 to form a strong mechanical interlocking force, effectively absorbing vibration energy and preventing interface debonding.

[0071] In the above scheme, the cross-shaped grid groove structure effectively guides the thermally conductive structural adhesive 3, anchors the interface, and enhances heat transfer. Under a pressure of 0.26 MPa, the thermally conductive structural adhesive 3 flows rapidly along channels of 2.8–3.2 mm. Cavities with a depth of 0.6–0.8 mm accommodate compression settling and thermal expansion allowances, while ribs with a line width of 1.4–1.6 mm provide appropriate constraint, preventing disordered accumulation of the thermally conductive structural adhesive 3. Specifically, the 1.5 mm rib width causes slight buckling of the ribs to absorb energy, reducing the peak stress within the adhesive layer to 4.2 MPa. The 3.0 mm grid spacing plus the 1.5 mm grid line width constitutes a high-density damping array, with each unit independently dissipating energy. The rib-shell interlocking induces filler rearrangement in the thermally conductive structural adhesive 3, resulting in a self-reinforcing peak at 200 Hz.

[0072] The above parameters were verified. For the combination of cross-grid groove structure and thermally conductive structural adhesive, the steady-state temperature rise of the fuse under a continuous current of 150A was 68.3℃, which was 24.3℃ lower than that of the traditional snap-fit ​​structure (92.6℃). The t-test showed that the core indicator p-value used to determine whether the result was statistically significant was less than 0.001, indicating that the difference was statistically significant.

[0073] In addition, the mesh structure 111 can adopt other shaped mesh groove structures, such as triangular mesh or regular hexagonal mesh, etc. Different shaped meshes can achieve energy dissipation by reserving deformation margin in the cavity and constraining the adhesive layer with ribs. It can be adapted to the application by simply adjusting the rib line width and mesh spacing parameters according to the product installation space and temperature rise requirements.

[0074] Figure 5 A schematic diagram of the structure of a second example of a base provided for at least one embodiment of this disclosure. Figure 6 A top view of a second example of a base provided for at least one embodiment of this disclosure. Figure 1 or Figure 3 Based on this, in order to enhance the structural stability of base 1, such as Figure 5 and Figure 6 As shown, the four sides of the base 1 are provided with vertical reinforcing ribs 14 to prevent the thermal protection barrier 12 from failing due to heat. The vertical reinforcing ribs 14 are arranged on the four sides of the base 1 to prevent the thermal protection barrier 12 from deforming or losing strength due to heat in the long-term high-temperature working environment, i.e., failing due to heat, thus ensuring the long-term effectiveness of its thermal protection function, and also improving the overall rigidity of the base 1.

[0075] Figure 7 This is a schematic diagram illustrating the composition of another fuse assembly provided for at least one embodiment of the present disclosure. Figure 1 , Figure 3 , Figure 4 and Figure 5 Based on any one of the solutions, in order to ensure that the fuse assembly has complete and reliable circuit functions, such as Figure 7 As shown, the fuse assembly also includes a copper busbar 5 and a copper busbar fastener 6. The copper busbar 5 is positioned axially on the fuse 2 and on the side of the adhesive-resistant structure 4 opposite to the fuse 2. One end of the copper busbar 5 is electrically connected to the fuse 2, and the other end is used for electrical connection to an external circuit. The copper busbar fastener 6 is used to securely connect the copper busbar 5 to the fuse 2. The electrical connection between one end of the copper busbar 5 and the fuse 2, and the connection to the external circuit at the other end, forms a current transmission channel. The copper busbar fastener 6 firmly secures the copper busbar 5 to the fuse 2, ensuring stable electrical contact, reducing contact resistance, and minimizing the risk of overheating. This design allows the fuse assembly to be directly connected in series in the high-voltage circuit of the battery pack, realizing its function as a core protection device.

[0076] Figure 8 This is a schematic diagram illustrating the composition of yet another fuse assembly provided for at least one embodiment of the present disclosure. Figure 1 or Figure 2 Based on the plan, such as Figure 8As shown, the fuse assembly also includes a base fastener 7. The base fastener 7 is used to fix the base 1 to a preset mounting point on the external battery pack tray. By fixing the entire base 1 to the preset mounting point on the external battery pack tray through the base fastener 7, the stability of the fuse assembly during vehicle operation is ensured, resisting bumps and vibrations and preventing electrical faults caused by displacement.

[0077] In some embodiments, Figure 8 Based on the design, the base fastener 7 uses bolts. After passing through the pre-set mounting holes on the base 1, the base fastener 7 is screwed into the pre-set threaded mounting holes on the battery pack tray to complete the locking and fixing of the base. This structure has high parts versatility, low procurement and assembly costs, and facilitates subsequent maintenance and disassembly, making it convenient to inspect and replace the fuse assembly. The connection strength of the bolts is sufficient to meet the vibration and impact requirements during vehicle operation, and can maintain a reliable fixing effect for a long time.

[0078] The following provides a preferred structure and assembly method for a fuse assembly that has been proven in practice. This solution takes into account reliability, manufacturability, and ease of maintenance, aiming to ensure the rationality of the overall design and the stability of long-term operation.

[0079] The fuse 2 body is fitted inside the fuse-bearing groove 11 of the base 1. The bottom end face of the fuse 2 is completely fitted with the inner bottom surface of the fuse-bearing groove 11 in the base 1, and the gap between the two is evenly filled with cured thermally conductive structural adhesive 3. The thermally conductive structural adhesive 3 achieves seamless bonding and fixation between the fuse 2 and the base 1. The base 1 is integrally injection molded from high-strength insulating and flame-retardant plastic. The left and right sides of the base 1 are symmetrically provided with raised adhesive-blocking structures 4. Through-hole fastener mounting holes are reserved at the corners of the base 1. The base 1 is locked and fixed to the preset mounting points on the battery pack tray by fasteners 7 passing through the fastener mounting holes.

[0080] The fuse-bearing groove 11 of the base 1 has a cross-grid groove structure to ensure maximum contact area. During assembly, the adhesive-blocking structure 4 is first arranged on the left and right sides of the bottom of the base 1. Then, a certain amount of thermally conductive structural adhesive 3 is evenly applied to the contact surface of the fuse-bearing groove 11 of the base 1. Finally, the fuse 2 is pressed and assembled into the fuse-bearing groove 11, and the air gaps are squeezed out to allow the thermally conductive structural adhesive 3 to evenly fill the tiny gaps.

[0081] After the thermally conductive structural adhesive 3 cures, it eliminates the assembly gap between the fuse 2 and the base 1, achieving all-around bonding and locking of the fuse 2 and preventing vibration-induced loosening and misalignment. Furthermore, utilizing the high thermal conductivity of the thermally conductive structural adhesive 3, the heat generated by the fuse 2 during operation is quickly conducted from the fuse 2's housing to the base 1, and then through the base 1 to the metal external battery pack tray. The large heat dissipation area of ​​the external battery pack tray enables rapid heat dissipation, constructing a complete three-level heat dissipation chain: fuse 2 - thermally conductive structural adhesive 3 - base 1 - tray.

[0082] The base 1 has symmetrical vertical adhesive-blocking structures 4 integrally formed on both sides. The vertical height of the adhesive-blocking structures 4 is higher than the maximum adhesive layer thickness of the fuse bearing groove 11 in the base 1, and the adhesive-blocking structures 4 protrude laterally 3-5mm from the edge of the fuse bearing groove 11 in the base 1, forming a closed limiting adhesive-blocking area. The adhesive-blocking strip is made of soft foam material. During the application of thermally conductive structural adhesive 3 and the pressing and assembly of the fuse 2, the excess thermally conductive structural adhesive 3 that overflows from the groove will be completely blocked by the adhesive-blocking structures 4 on both sides, confining it to the inside of the fuse bearing groove 11 in the base 1 and the inner area of ​​the adhesive-blocking structures 4, completely preventing the thermally conductive structural adhesive 3 from overflowing outward and contacting the outer copper busbar 5 used for conduction.

[0083] The four sides of the base 1 are designed to be raised and extended and equipped with vertical reinforcing ribs 14. The overall height of the four sides of the base is 5~10mm greater than the heating top surface of the fuse wire of the fuse 2, so that the side walls of the base 1 completely surround the bottom and side protection structure of the fuse 2.

[0084] At least one embodiment of this disclosure also provides a battery pack integrating a battery pack body, a battery pack tray, and a fuse assembly from the preceding embodiments. The fuse assembly is fixed to a predetermined mounting point on the battery pack tray by a base fastener (such as a fastening bolt), and its copper busbar is electrically connected to the high-voltage circuit of the battery pack body. This battery pack inherits all the advantages of the fuse assembly, offering higher safety, power density, and cycle life.

[0085] Those skilled in the art will understand that all or part of the processes in the above method embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory (FM), hard disk drive (HDD), or solid-state drive (SSD), etc. The storage medium can also include combinations of the above types of memory.

[0086] Although embodiments of the present disclosure have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present disclosure, and all such modifications and variations fall within the scope defined by the appended claims.

[0087] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A fuse assembly, characterized in that, include: The base (1) is provided with a fuse bearing groove (11) and a thermal protection enclosure (12). The fuse (2) is installed in the fuse bearing groove (11) and located inside the thermal protection enclosure (12), and the height of the heating top surface of its fuse wire is lower than the height of the thermal protection enclosure (12). Thermally conductive structural adhesive (3) is disposed between the contact surfaces of the fuse (2) and the fuse bearing groove (11), and is used to achieve bonding and fixing of the fuse (2) and the base (1) and heat conduction; and, A baffle structure (4) is disposed on at least one side of the base (1) and is used to limit the flow range of the thermally conductive structural adhesive (3).

2. The fuse assembly according to claim 1, characterized in that, Also includes: A copper busbar (5) is disposed on the axial side of the fuse (2) and located on the side of the adhesive-blocking structure (4) away from the fuse (2). One end of the copper busbar (5) is electrically connected to the fuse (2), and the other end of the copper busbar (5) is used to be electrically connected to an external circuit. and, Copper busbar fastener (6) is used to fix the copper busbar (5) to the fuse (2).

3. The fuse assembly according to claim 1 or 2, characterized in that, Also includes: The base fastener (7) is used to fix the base (1) to a preset mounting point on the external battery pack tray.

4. The fuse assembly according to claim 1 or 2, characterized in that, The bottom end face of the fuse bearing groove (11) is provided with: A mesh structure (111) is used to guide the distribution of the thermally conductive structural adhesive (3) so that the thermally conductive structural adhesive (3) is evenly distributed in the gap between the bottom end face of the fuse (2) and the bottom end face of the fuse bearing groove (11).

5. The fuse assembly according to claim 1 or 2, characterized in that, The bottom end face of the fuse bearing groove (11) is provided with: A thermally conductive metal layer (13) extends to the external mounting hole of the base (1) and serves as the main heat flow channel of the fuse assembly to form a three-level heat dissipation chain in which the fuse (2), the thermally conductive structural adhesive (3) and the base (1) conduct heat in sequence.

6. The fuse assembly according to claim 1 or 2, characterized in that, The base (1) is integrally injection molded from insulating and flame-retardant plastic; and, The thermal protection enclosure (12) is formed by the four sides of the base (1). The height of the thermal protection enclosure (12) exceeds the height of the fuse wire heating top surface of the fuse (2) by 5~10mm, so that the thermal protection enclosure (12) surrounds the fuse (2).

7. The fuse assembly according to claim 6, characterized in that, The base (1) is provided with vertical reinforcing ribs (14) on its four sides to prevent the heat protection barrier (12) from failing due to heat.

8. The fuse assembly according to claim 1 or 2, characterized in that, The base (1) is provided with a gradient pore structure on its four sides. The porosity of the gradient pore structure gradually changes from the first porosity at the bottom to the second porosity at the top, so as to build a thermal barrier wall and force heat to be conducted to the bottom of the base (1). Wherein, the first porosity is less than the second porosity.

9. The fuse assembly according to claim 4, characterized in that, The adhesive-blocking structure (4) includes vertical adhesive-blocking strips made of elastic cushioning material and symmetrically arranged on both sides of the axial direction of the base (1), and... The vertical height of the adhesive barrier structure (4) is higher than the adhesive layer thickness at each point in the fuse bearing groove (11), and it protrudes laterally from the edge of the fuse bearing groove (11) by 3~5mm to form a closed limiting adhesive barrier area to prevent excess thermally conductive structural adhesive (3) overflowing from the fuse bearing groove (11) from contacting the copper busbar (5). The thermally conductive structural adhesive (3) has a thermal conductivity ≥3.5W / m·K, a peel strength ≥8N / mm, a shear strength ≥25MPa, a coating amount of (0.32±0.03)g / cm², and a corresponding adhesive layer thickness of 800~1000μm; The grid structure (111) is a cross-shaped grid groove structure. The groove depth of the cross-shaped grid groove structure is 0.6~0.8mm, the grid line width is 1.4~1.6mm, and the grid spacing is 2.8~3.2mm.

10. A battery pack, characterized in that, include: The battery pack body, the battery pack tray for mounting the battery pack body, and the fuse assembly according to any one of claims 1-9, the fuse assembly being fixed to the battery pack tray and used for electrical connection with the external circuit.

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