Pre-charging resistor

Abstract

The pre-charging resistor comprises a shell, a resistor assembly and a slow heating layer, the shell comprises a bottom plate and a side plate, the side plate is arranged in the first direction, the bottom plate is arranged on the side, in the first direction, of the side plate, the side plate and the bottom plate are connected to define a containing cavity, the resistor assembly is arranged in the containing cavity, and the slow heating layer is arranged on the side, facing the resistor assembly, of the side plate. And the slow heating layer covers the side plate. According to the application, the slow heating layer is arranged to cover the side plate, so that the diffusion speed of heat generated when the resistor assembly works can be reduced, the speed of heat diffusion from the side plate to the outside of the shell is reduced, the temperature rise speed around the side plate is reduced, the influence on electronic components around the side plate is reduced, and the possibility of failure of the electronic components is reduced.

Description

Technical Field

[0001] This application belongs to the field of pre-charge technology, specifically relating to a pre-charge resistor. Background Technology

[0002] When a high-voltage system is energized, the instantaneous current in the system is very large, which can easily damage the electronic components in the system. Therefore, high-voltage systems are generally equipped with a pre-charge module to reduce the instantaneous current when the system is energized.

[0003] The precharge module is a safety component in a high-voltage system, consisting of a precharge resistor and a precharge relay connected in series. The precharge resistor mainly comprises a housing, a ceramic rod, and a resistance wire wound around the ceramic rod, with the resistance wire connected in the circuit. When the high-voltage system is energized, the precharge relay closes, connecting the resistance wire in the precharge module to the circuit. The resistance wire limits the peak value of the instantaneous current, thus providing safety protection.

[0004] In related technologies, the pre-charge resistor in the pre-charge module generates a large amount of heat when it is working. The heat dissipates rapidly from the housing of the pre-charge resistor, which can easily cause the temperature around the pre-charge resistor to rise rapidly. This can easily affect surrounding electronic components (such as pre-charge relays) and may cause the electronic components to fail. Summary of the Invention

[0005] This application aims to provide a precharge resistor that can solve the problem that the heat from existing precharge resistors may affect surrounding electronic components.

[0006] To solve the above-mentioned technical problems, this application is implemented as follows: This application provides a pre-charge resistor, comprising: a housing, a resistor assembly, and a heat-slowing layer. The housing includes a bottom plate and a side plate, the side plate being disposed around a first direction, the bottom plate being disposed on one side of the side plate along the first direction, the side plate being connected to the bottom plate to form a receiving cavity, the resistor assembly being disposed in the receiving cavity, and the heat-slowing layer being disposed on the side of the side plate facing the resistor assembly, the heat-slowing layer covering the side plate.

[0007] Optionally, the heat-reducing layer is further disposed on the side of the base plate facing the resistor assembly, and the heat-reducing layer covers the base plate.

[0008] Optionally, the ratio of the wall thickness of the side plate to the thickness of the heat-retarding layer is 1-5.

[0009] Optionally, the heat-retarding layer includes a first sub-layer and a second sub-layer arranged along a second direction, wherein the second sub-layer is connected to at least one side of the first sub-layer along the second direction; The first sublayer is projected along a third direction to form a first projection area, and the resistor component is projected along the third direction to form a second projection area. The second projection area falls within the first projection area, and the first direction, the second direction, and the third direction are perpendicular to each other.

[0010] Optionally, the thickness of the first sub-layer along the third direction is W1, and the thickness of the second sub-layer along the third direction is W2, satisfying: W1 > W2.

[0011] Optionally, the first sub-layer and the second sub-layer satisfy: 1 ​​< W1 / W2 ≤ 2.5.

[0012] Optionally, the heat-retarding layer further includes a transition layer that connects the first sub-layer and the second sub-layer, wherein the thickness of the transition layer gradually decreases in the third direction from the first sub-layer to the second sub-layer.

[0013] Optionally, the pre-charge resistor further includes a filling layer disposed within the receiving cavity, and the resistor assembly is at least partially embedded within the filling layer.

[0014] Optionally, the thermal conductivity of the heat-retarding layer is less than that of the filler layer.

[0015] Optionally, the thermal conductivity of the heat-retarding layer is 0.2 W / (m·K)-0.7 W / (m·K).

[0016] Optionally, the thermal conductivity of the filling layer is 0.8 W / (m·K)-3.5 W / (m·K).

[0017] Optionally, the resistor assembly includes a support member and a resistance wire, the support member being disposed within the receiving cavity, and the resistance wire being wound around the support member.

[0018] Optionally, the resistor assembly further includes a thermally conductive layer that covers the surfaces of the support and the resistance wire.

[0019] Optionally, the base plate is provided with a mounting platform, the mounting platform is provided with a mounting protrusion, the support member is provided with a support flange, the support flange is provided with a mounting hole, and the mounting protrusion is inserted into the mounting hole.

[0020] Optionally, the pre-charge resistor further includes a first conductive element and a second conductive element, which are respectively disposed at both ends of the support and are both connected to the support. The first conductive element and the second conductive element are both electrically connected to the resistance wire. The first conductive element and the second conductive element extend from the side of the side plate away from the bottom plate and are used for the installation and fixing of the pre-charge resistor.

[0021] In this embodiment, a receiving cavity is formed by connecting the base plate and the side plate, creating a receiving space, and the resistor assembly is disposed in the receiving cavity. By providing a heat-delaying layer to cover the side plate, the diffusion rate of heat generated when the resistor assembly is working can be reduced. This reduces the rate at which heat diffuses from the side plate to the outside of the housing, reduces the rate of temperature rise around the side plate, thereby reducing the impact on electronic components (such as pre-charged relays) around the side plate and reducing the possibility of electronic component failure.

[0022] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0023] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is an exploded view of the pre-charge resistor in an embodiment of this application; Figure 2 This is a perspective view of the pre-charge resistor in an embodiment of this application; Figure 3 This is a cross-sectional view of the pre-charge resistor in an embodiment of this application; Figure 4 This is a top view of the housing and resistor assembly according to an embodiment of this application; Figure 5 This is a perspective view of the housing according to an embodiment of this application; Figure 6 This is a perspective view of the support member according to an embodiment of this application; Figure 7 This is a perspective view of the housing and support components installed according to an embodiment of this application.

[0024] Figure label: 10. Housing; 11. Base plate; 111. Mounting platform; 112. Mounting protrusion; 12. Side plate; 121. First sub-plate; 122. Second sub-plate; 13. Receiving cavity; 20. Resistor assembly; 30. Heat-retarding layer; 31. First sub-layer; 32. Second sub-layer; 33. Transition layer; 40. Filling layer; 50. Support member; 51. Support flange; 52. Mounting hole; 60. Thermally conductive layer; 70. First conductive member; 80. Second conductive member; 90. Resistance wire; X, First direction; Y, Second direction; Z, Third direction. Detailed Implementation

[0025] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0026] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0027] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0028] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0029] In the initial stage of powering up a high-voltage electrical system (such as the power battery system of an electric vehicle, energy storage converter, etc.), due to the presence of a large capacitive load (such as a DC support capacitor) in the system, directly closing the main contactor will generate a huge inrush current, which may damage key components such as power devices and relays.

[0030] To limit the inrush current, a pre-charge module is typically connected in series in the high-voltage main circuit. The pre-charge module mainly consists of a pre-charge relay and a pre-charge resistor. When the system is powered on, the pre-charge relay is closed first, and the capacitive load is current-limited charged through the pre-charge resistor. When the system voltage is close to the power supply voltage, the main contactor is closed, thereby achieving a smooth power-on.

[0031] However, the pre-charge resistor generates a significant amount of heat during operation. This heat dissipates from the resistor's casing and is then transferred to the pre-charge relay via conduction and radiation, causing the internal temperature of the pre-charge relay to rise. Excessive temperature can affect the contact resistance, mechanical properties, and insulation performance of the contacts in the pre-charge relay. In severe cases, this can lead to the pre-charge relay sticking, refusing to operate, or premature failure, thereby impacting the safety and reliability of the entire high-voltage system.

[0032] Based on this, this application proposes a pre-charge resistor to solve some or all of the above-mentioned technical problems.

[0033] The pre-charge resistor provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0034] like Figure 1 and Figure 2 As shown, the pre-charge resistor according to an embodiment of this application includes: a housing 10, a resistor assembly 20, and a heat-delaying layer 30. The housing 10 includes a bottom plate 11 and a side plate 12. The side plate 12 is disposed around a first direction X. The bottom plate 11 is disposed on one side of the side plate 12 along the first direction X. The side plate 12 and the bottom plate 11 are connected to form a receiving cavity 13. The resistor assembly 20 is disposed in the receiving cavity 13. The heat-delaying layer 30 is disposed on the side of the side plate 12 facing the resistor assembly 20 and covers the side plate 12.

[0035] It should be noted that, in this embodiment, the "heat-reducing layer 30" refers to a layered structure disposed on the inner surface of the housing 10, whose main function is to reduce the rate at which heat generated by the resistive component 20 diffuses to the outside of the housing 10. The heat-reducing layer 30 is only intended to slow down heat transfer, not to completely insulate against heat; heat can still diffuse outward through the heat-reducing layer 30. In other words, the heat-reducing layer 30 can be a material layer with low thermal conductivity, thereby reducing the rate of heat transfer.

[0036] In this embodiment, a receiving cavity 13 is formed by connecting the base plate 11 and the side plate 12, creating a receiving space, and the resistor assembly 20 is disposed in the receiving cavity 13. By providing a heat-reducing layer 30 to cover the side plate 12, the diffusion rate of heat generated by the resistor assembly 20 during operation can be reduced. This reduces the rate at which heat diffuses from the side plate 12 to the outside of the housing 10, reduces the rate of temperature rise around the side plate 12, thereby reducing the impact on electronic components (such as pre-charged relays) around the side plate 12 and reducing the possibility of electronic component failure.

[0037] In some embodiments, a pre-charge resistor is applied in a high-voltage system to reduce the rate at which heat diffuses from the side plate 12 of the housing 10, thereby reducing the impact on electronic components (e.g., pre-charge relays) around the side plate 12, reducing the possibility of electronic component failure, and thus improving the reliability and safety of the entire high-voltage system in long-term operation.

[0038] Specifically, the housing 10 of the pre-charge resistor can typically be made of a material with good thermal conductivity, such as a metal, which can provide the necessary basic heat dissipation and structural strength.

[0039] In some embodiments, the housing 10 may be made of materials such as aluminum or aluminum alloy, and the surface may be anodized, giving it good thermal conductivity, mechanical strength and lightweight properties.

[0040] like Figure 1 As shown, the housing 10 has a first direction X, a second direction Y and a third direction Z that are perpendicular to each other. The first direction X can be the height direction of the housing 10, the second direction Y can be the length direction of the housing 10, and the third direction Z can be the width direction of the housing 10.

[0041] It should be noted that the first direction X, the second direction Y, and the third direction Z are mutually perpendicular. Specifically, this can be "perpendicular" in the strict sense, for example, the angle between the first direction X and the second direction Y is 90°; or it can be "approximately perpendicular," specifically meaning that the angle between any two of the first direction X, the second direction Y, and the third direction Z includes a certain error. Considering the measurement and the error associated with the measurement of a specific quantity (i.e., the limitations of the measurement system), this error is within the acceptable deviation range for a specific value as determined by a person skilled in the art. For example, the angle between the first direction X and the second direction Y is 90° ± 5°.

[0042] like Figure 3 As shown, the housing 10 includes a bottom plate 11 and a side plate 12, wherein the side plate 12 is arranged around a first direction X, and the bottom plate 11 is located on one side of the side plate 12 along the first direction X, for example, the bottom plate 11 is located below the side plate 12. The side plate 12 is connected to the bottom plate 11, and the two together form a receiving cavity 13 with an opening on one side.

[0043] In some embodiments, the side plate 12 and the bottom plate 11 can be connected by various methods such as integral molding, welding, and bonding. The connection can be flexibly set according to the actual situation, and the embodiments of this application do not limit this.

[0044] It is understandable that, such as Figure 2 and Figure 4As shown, the housing 10 is generally rectangular in shape. In this case, the side plate 12 may include two first sub-plates 121 opposite each other along the second direction Y, and two second sub-plates 122 opposite each other along the third direction Z. The two first sub-plates 121 and the two second sub-plates 122 are connected to form the side plate 12.

[0045] The resistor assembly 20 is disposed inside the receiving cavity 13. When the resistor assembly 20 is working, it generates heat, which can diffuse out from the side plate 12 and the bottom plate 11 of the housing 10.

[0046] like Figure 3 As shown, a heat-reducing layer 30 is disposed on the side of the side plate 12 facing the resistor assembly 20, and the heat-reducing layer 30 covers the side plate 12. The heat-reducing layer 30 has a heat insulation function and can reduce the rate of heat diffusion. In this way, the heat-reducing layer 30 can reduce the rate at which heat diffuses from the side plate 12 and reduce the rate of temperature rise in the external space of the side plate 12.

[0047] Understandably, the larger the area of ​​the heat-reducing layer 30 covering the side plate 12, the better the heat insulation effect on the side plate 12. The area where the heat-reducing layer 30 is installed must at least satisfy the following conditions: the orthogonal projection of the heating element in the resistor assembly 20 along the second direction Y falls entirely into the heat-reducing layer 30 installed on the first sub-plate 121, and the orthogonal projection of the heating element in the resistor assembly 20 along the third direction Z falls entirely into the heat-reducing layer 30 installed on the second sub-plate 122. In this way, the heat-reducing layer 30 can effectively block heat transfer.

[0048] In some embodiments, the heat-reducing layer 30 covers the entire area of ​​the side panel 12, that is, the area of ​​the heat-reducing layer 30 is the same as the area of ​​the inner surface of the side panel 12.

[0049] In addition, since the heat-retardant layer 30 is located in the electronic component, it should also have an insulating function to achieve insulation between the two components.

[0050] In some embodiments, the heat-reducing layer 30 may be made of a material with low thermal conductivity, such as mica, porous heat-insulating material, ceramic fiber or other heat-insulating coating, as long as it can achieve heat insulation and electrical insulation.

[0051] In some embodiments, the heat-retarding layer 30 can be made by cutting and pasting a flexible mica sheet. The mica sheet is about 1.0 mm thick and has a thermal conductivity of about 0.5 W / (m·K), while also possessing extremely high insulation strength (>10 kV / mm). The mica sheet can be firmly pasted onto the inner wall of the side plate 12 using a high-temperature resistant silicone adhesive.

[0052] It should be noted that in practical applications, other electronic components (such as precharge relays) are generally located on the side of the precharge resistor along the second direction Y or the third direction Z, rather than on the side along the first direction X. Therefore, the heat-reducing layer 30 is located on the side plate 12 to reduce the speed at which heat diffuses from the side plate 12 to the outside, that is, to reduce the speed at which heat diffuses to the outside along the second direction Y and the third direction Z.

[0053] In this embodiment, heat must pass through a low-thermal-conductivity heat-retarding layer 30 (e.g., mica board) before being transferred to the side panel 12. The heat-retarding layer 30 significantly slows down the rate and amount of heat transfer to the side panel 12. Therefore, the temperature rise curve of the outer surface of the side panel 12 becomes flatter, and its steady-state temperature is significantly lower than that without a heat insulation structure. Actual measurements show that, under the same power and operating conditions, after installing a 1mm thick heat-retarding layer 30, the peak air temperature rise at 10mm from the outer surface of the side panel 12 is reduced by approximately 30%-40%, effectively mitigating the thermal shock to side-mounted electronic components (e.g., pre-charged relays).

[0054] Optionally, such as Figure 3 As shown, the heat-retarding layer 30 is also provided on the side of the base plate 11 facing the resistor assembly 20, and the heat-retarding layer 30 covers the base plate 11.

[0055] In this embodiment, by also providing a heat-reducing layer 30 on the side of the base plate 11 facing the resistor assembly 20, and covering the base plate 11 with the heat-reducing layer 30, the rate at which heat diffuses from the base plate 11 can be reduced, thereby reducing the rate of temperature rise outside the base plate 11 and further reducing the impact on surrounding electronic components. In this way, the heat-reducing layer 30 on the inner surface of the base plate 11 and the heat-reducing layer 30 on the inner surface of the side plate 12 form a complete "inner liner" type heat insulation lining, blocking the heat generated by the resistor assembly 20 from the bottom and sides in all directions.

[0056] Specifically, the form in which the heat-retarding layer 30 covers the bottom plate 11 can be set with reference to the form in which the heat-retarding layer 30 covers the side plate 12, and will not be described in detail here.

[0057] Optionally, the ratio of the wall thickness of the side plate 12 to the thickness of the heat-retarding layer 30 is 1-5.

[0058] In this embodiment, by setting the ratio of the wall thickness of the side plate 12 to the thickness of the heat-reducing layer 30 to 1-5, it is ensured that the side plate 12 has sufficient mechanical strength and rigidity to protect the internal components, while the heat-reducing layer 30 has an effective thickness to perform its heat insulation function. This avoids the heat-reducing layer 30 being too thin, resulting in poor performance, or too thick, causing it to occupy internal space, increase costs, or affect the installation of other components. Simultaneously, the heat-reducing layer 30 also needs to serve an electrical insulation function; therefore, the heat-reducing layer 30 should have sufficient thickness to prevent electrical breakdown.

[0059] For pre-charge resistors of different power levels and sizes, the wall thickness of the side plate 12 and the thickness of the heat-delaying layer 30 need to be matched. Extensive thermal simulation analysis and experimental verification revealed that a ratio of 1 to 5 between the wall thickness of the side plate 12 and the thickness of the heat-delaying layer 30 effectively balances structural strength, thermal insulation, and space occupancy. If the ratio is too small (i.e., the heat-delaying layer 30 is too thick), while the thermal insulation effect is good, it excessively encroaches on the space of the housing 13, potentially affecting the size of the resistor assembly 20 and increasing costs; if the ratio is too large (i.e., the heat-delaying layer 30 is too thin), the thermal insulation effect is limited and fails to meet the expected goals.

[0060] For example, for a medium-power (peak power approximately 1.5 kW) precharge resistor, the aluminum alloy side plate 12 has a wall thickness of 2.5 mm. A ceramic fiber felt with a thermal conductivity of approximately 0.3 W / (m·K) is selected as the heat-retarding layer 30, with a thickness of 1.0 mm. The ratio of the side plate 12 wall thickness to the heat-retarding layer thickness is 2.5, falling within the preferred range. Tests show that with this configuration, the heat flux density between the outer surface of the side plate 12 and the mounting surface of adjacent electronic components is reduced by approximately 60%, and the measured temperature rise of adjacent electronic components during precharge does not exceed 25 K, far below their permissible temperature rise limit (typically 40-60 K).

[0061] Specifically, the wall thickness of the side plate 12 and the bottom plate 11 is generally the same. In some embodiments, if the thickness of the side plate 12 is 3mm, then the thickness of the heat-reducing layer 30 can be 0.6mm-3mm. For example, the thickness of the heat-reducing layer 30 can be any value or a range between any two values ​​from 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, and 3mm. It can be flexibly set according to the actual situation, and the embodiments of this application do not limit it in this way.

[0062] Optionally, such as Figure 4 As shown, the heat-retarding layer 30 includes a first sub-layer 31 and a second sub-layer 32 arranged along the second direction Y, and the second sub-layer 32 is connected to at least one side of the first sub-layer 31 along the second direction Y; The first sublayer 31 is projected along the third direction Z to form a first projection area, and the resistor component 20 is projected along the third direction Z to form a second projection area. The second projection area falls into the first projection area, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0063] In this embodiment, by providing a heat-damping layer 30 comprising a first sub-layer 31 and a second sub-layer 32, the second projection area formed by the resistor component 20 falls into the first projection area formed by the first sub-layer 31, so that the resistor component 20 is completely shielded by the first sub-layer 31 along the third direction Z. Thus, the first sub-layer 31 can effectively provide heat insulation, achieving a good heat insulation effect. Furthermore, the second sub-layer 32 is connected to at least one side of the first sub-layer 31 along the second direction Y, forming an auxiliary heat insulation structure to further optimize the heat insulation effect.

[0064] Specifically, such as Figure 4 As shown, the resistor assembly 20 is generally disposed in the middle region of the housing 10. The resistor assembly 20 has a gap with the housing 10 along the second direction Y. Thus, the first sub-layer 31 can be located in the middle region of the second sub-plate 122, corresponding to the position of the resistor assembly 20. The second sub-layer 32 can be connected to both sides of the first sub-layer 31, and is generally located in the edge region of both sides of the second sub-plate 122.

[0065] It should be noted that the second projection area actually refers to the projection area of ​​the heating component (i.e., resistor) in the resistor assembly 20, rather than the projection area of ​​other components (such as components that play a supporting role). In this way, the first sub-layer 31 is set in the area where the heating component is located, so as to play a heat insulation role.

[0066] Optionally, such as Figure 4 As shown, the thickness of the first sublayer 31 along the third direction Z is W1, and the thickness of the second sublayer 32 along the third direction Z is W2, satisfying: W1 > W2.

[0067] In this embodiment, by setting W1 > W2, the thickness of the first sub-layer 31 is greater than the thickness of the second sub-layer 32, thereby increasing the heat insulation effect of the first sub-layer 31. Thus, the first sub-layer 31, corresponding to the area where the heat-generating component is located, has a larger thickness, resulting in better heat insulation. Furthermore, the smaller thickness of the second sub-layer 32 reduces the amount of material used and lowers manufacturing costs.

[0068] In other words, a thicker first sub-layer 31 with better heat insulation is covered in the middle area of ​​the side plate 12 facing the heating component to provide stronger heat insulation. On both sides of the projection area of ​​the heating component, since the heat flux density is relatively low, the thickness of the heat-retarding layer 30 can be appropriately reduced, that is, a thinner second sub-layer 32 is set to save materials, reduce weight, and reduce manufacturing costs.

[0069] Optionally, the first sub-layer 31 and the second sub-layer 32 satisfy: 1 ​​< W1 / W2 ≤ 2.5.

[0070] In this embodiment, by setting 1 < W1 / W2 ≤ 2.5, compared to the case where W1 / W2 > 2.5, the thickness of the second sub-layer 32 in this range is greater, which makes the insulation effect between the housing 10 and the resistor assembly 20 better. The second sub-layer 32 still maintains sufficient thickness to provide reliable electrical insulation, and the second sub-layer 32 is less likely to be electrically broken down, thereby ensuring the electrical performance of the entire pre-charge resistor.

[0071] Specifically, the value of W1 / W2 can be any value among 1.1, 1.3, 1.5, 1.7, 1.9, 2.0, 2.1, 2.3, and 2.5, or a range between any two values. It can be flexibly set according to the actual situation, and this application embodiment does not limit it.

[0072] Optionally, such as Figure 4 As shown, the heat-retarding layer 30 also includes a transition layer 33, which connects the first sub-layer 31 and the second sub-layer 32. The thickness of the transition layer 33 gradually decreases along the third direction Z from the first sub-layer 31 to the second sub-layer 32.

[0073] In this embodiment, a transition layer 33 is provided between the first sub-layer 31 and the second sub-layer 32. The thickness of the transition layer 33 gradually decreases, avoiding abrupt changes in thickness from the first sub-layer 31 to the second sub-layer 32 and preventing the formation of sharp corners, thereby avoiding stress concentration at the connection between the first sub-layer 31 and the second sub-layer 32. Simultaneously, the gradual decrease in the thickness of the transition layer 33 better aligns with the principle that the heat emitted by the heating element in the resistor assembly 20 gradually decreases in the direction away from the heating element, thus optimizing the heat insulation effect.

[0074] Specifically, such as Figure 4 As shown, the thickness of the transition layer 33 gradually decreases. The thickness of the end of the transition layer 33 near the first sub-layer 31 is equal to the thickness of the first sub-layer 31, and the thickness of the end of the transition layer 33 near the second sub-layer 32 is equal to the thickness of the second sub-layer 32.

[0075] In some embodiments, the thickness of the transition layer 33 may decrease linearly, thereby forming a sloping plane.

[0076] In other embodiments, the thickness of the transition layer 33 may decrease non-linearly, thereby forming a curved surface, such as a concave or convex surface.

[0077] It is understandable that the first projection area mentioned above is formed by projecting the first sub-layer 31 along the third direction Z. This refers to the first sub-layer 31 on the two second sub-plates 122 (i.e., the two opposite parts of the side plate 12 along the third direction Z). The side plate 12 also has a first sub-plate 121 (i.e., the two opposite parts of the side plate 12 along the second direction Y). The heat-retarding layer 30 on the first sub-plate 121 can also be set with reference to the heat-retarding layer 30 on the second sub-plate 122. Only the corresponding projection direction and thickness direction need to be changed, which will not be described in detail here.

[0078] Thus, the heat-retarding layer 30 on each portion of the side plate 12 (i.e., the two first sub-plates 121 and the two second sub-plates 122) can include a first sub-layer 31, a second sub-layer 32 and a transition layer 33, thereby corresponding to the heat-generating component in the resistor assembly 20.

[0079] Optionally, such as Figure 1 As shown, the pre-charge resistor also includes a filling layer 40, which is disposed within the receiving cavity 13, and the resistor assembly 20 is at least partially embedded within the filling layer 40.

[0080] In this embodiment, by providing a filling layer 40 inside the receiving cavity 13, the filling layer 40 can fix and protect the components inside the receiving cavity 13, preventing dust and other impurities from entering. At the same time, the filling layer 40 can also absorb the heat generated by the resistor assembly 20, preventing heat from accumulating near the resistor assembly 20, thereby preventing the resistor assembly 20 from overheating.

[0081] Specifically, the filling layer 40 is formed by filling and curing materials such as cement mortar. The cement mortar can be a mixture of substances such as talc powder, quartz sand, and alcohol. After the cement mortar is poured, it cures over a period of time, thereby achieving a fixed connection with the shell 10 and serving to fix the components inside the receiving cavity 13.

[0082] Optionally, the thermal conductivity of the heat-retarding layer 30 is less than that of the filler layer 40.

[0083] In this embodiment of the application, by setting the thermal conductivity of the heat-reducing layer 30 to be less than that of the filling layer 40, the heat-reducing layer 30 can better achieve heat insulation and reduce the rate at which heat diffuses from the heat-reducing layer 30 to the outside.

[0084] Specifically, the low thermal conductivity heat-retarding layer 30 mainly blocks heat transfer to the shell 10, forming a heat insulation structure; while the relatively high thermal conductivity filling layer 40 mainly absorbs the heat generated by the resistor component 20 relatively efficiently, thereby preventing excessive heat accumulation at the resistor component 20 and preventing the resistor component 20 from overheating. In this way, the combination of the low thermal conductivity heat-retarding layer 30 and the relatively high thermal conductivity filling layer 40 synergistically achieves the thermal management effect of "internal heat dissipation and external insulation".

[0085] Optionally, the thermal conductivity of the heat-retarding layer 30 is 0.2 W / (m·K) to 0.7 W / (m·K); and / or, the thermal conductivity of the filler layer 40 is 0.8 W / (m·K) to 3.5 W / (m·K).

[0086] In this embodiment of the application, by setting specific thermal conductivity ranges for the heat-retarding layer 30 and the filling layer 40, the heat-retarding layer 30 is ensured to have excellent thermal insulation performance, while the filling layer 40 has moderate thermal conductivity to balance internal heat dissipation requirements with other functions such as insulation and fixation.

[0087] Specifically, the thermal conductivity of the heat-retarding layer 30 can be any value or a range between any two values ​​from 0.2W / (m·K), 0.3W / (m·K), 0.4W / (m·K), 0.5W / (m·K), 0.6W / (m·K), and 0.7W / (m·K). It can be flexibly set according to the actual situation, and the embodiments of this application do not limit it.

[0088] The thermal conductivity of the filling layer 40 can be any value or a range between any two values ​​from 0.8 W / (m·K), 1.0 W / (m·K), 1.5 W / (m·K), 2.0 W / (m·K), 2.5 W / (m·K), 3.0 W / (m·K), and 3.5 W / (m·K). It can be flexibly set according to the actual situation, and the embodiments of this application do not limit it.

[0089] Optionally, such as Figure 1 and Figure 2 As shown, the resistor assembly 20 includes a support member 50 and a resistance wire 90. The support member 50 is disposed in the receiving cavity 13, and the resistance wire 90 is wound around the support member 50.

[0090] In this embodiment, by providing the support member 50, a support structure can be formed, providing a stable winding skeleton and electrical insulation foundation for the resistance wire 90. By winding the resistance wire 90 around the support member 50, the resistance wire 90 can be supported. Simultaneously, winding the resistance wire 90 around the support member 50 can increase the length of the resistance wire 90.

[0091] Specifically, such as Figure 2 and Figure 6 As shown, the support member 50 can be in the shape of a round rod with a smooth, burr-free surface, which facilitates the winding of the resistance wire 90 without damaging it. The resistance wire 90 can be wound onto the support member 50 in a spiral manner.

[0092] In some embodiments, the support member 50 may be made of a material with high electrical insulation and good heat resistance (able to withstand high temperatures above 300°C for a long time), such as ceramic materials, fiber materials, etc.

[0093] In some embodiments, the resistance wire 90 may be made of materials such as nickel-chromium alloy, iron-chromium-aluminum alloy, etc.

[0094] The materials used to make the support 50 and the resistance wire 90 can be flexibly set according to the actual situation, and this application embodiment does not limit them.

[0095] It is understandable that the second projection area actually refers to the projection area of ​​the resistance wire 90 along the third direction Z, rather than the projection area of ​​the support 50. In this way, the first sub-layer 31 is set in the area where the resistance wire 90 is located, and plays a role in heat insulation.

[0096] Optionally, such as Figure 3 As shown, the resistor assembly 20 also includes a thermally conductive layer 60, which covers the surfaces of the support 50 and the resistance wire 90.

[0097] In this embodiment, by providing a heat-conducting layer 60 on the surfaces of the support 50 and the resistance wire 90, the resistance wire 90 is in direct contact with the heat-conducting layer 60. The heat-conducting layer 60 can quickly conduct the heat generated by the resistance wire 90 to other areas, preventing heat from accumulating on the resistance wire 90 and thus preventing overheating. This helps to reduce the local operating temperature of the resistance wire 90 and extend its lifespan. Furthermore, the support 50 more effectively transfers heat to the filling layer 40 or the surrounding environment, optimizing the internal heat transfer path.

[0098] Specifically, the thermal conductivity of the thermally conductive layer 60 is higher than that of the filler layer 40, thereby improving the thermal conductivity.

[0099] In some embodiments, the thermally conductive layer 60 may be formed by covering the surfaces of the support 50 and the resistance wire 90 with a thermally conductive adhesive layer, a thermally conductive coating layer, or the like.

[0100] Optionally, such as Figure 5 , Figure 6 and Figure 7 As shown, the base plate 11 is provided with a mounting platform 111, the mounting platform 111 is provided with a mounting protrusion 112, the support member 50 is provided with a support flange 51, the support flange 51 is provided with a mounting hole 52, and the mounting protrusion 112 is inserted into the mounting hole 52.

[0101] In this embodiment, by providing a mounting platform 111 on the base plate 11 and a supporting flange 51 on the support member 50, the mounting platform 111 and the supporting flange 51 are engaged through mounting protrusions 112 and mounting holes 52, thereby positioning the support member 50 relative to the base plate 11 and preventing the support member 50 from moving relative to the base plate 11. Thus, during the filling process of the filling layer 40, the support member 50 will not change position, ensuring product consistency.

[0102] Specifically, since the mounting platform 111 is provided on the base plate 11, the heat-reducing layer 30 can also cover the mounting platform 111 and the mounting protrusion 112, thereby ensuring the heat insulation effect.

[0103] Optionally, such as Figure 1 and Figure 3 As shown, the pre-charge resistor also includes a first conductive element 70 and a second conductive element 80. The first conductive element 70 and the second conductive element 80 are respectively disposed at both ends of the support 50 and are both connected to the support 50. The first conductive element 70 and the second conductive element 80 are both electrically connected to the resistance wire 90. The first conductive element 70 and the second conductive element 80 extend from the side plate 12 away from the bottom plate 11. The first conductive element 70 and the second conductive element 80 are used for the installation and fixing of the pre-charge resistor.

[0104] In this embodiment, by positioning the first conductive element 70 and the second conductive element 80 on opposite sides of the support member 50, it facilitates electrical connection between the two ends of the resistance wire 90 and the first conductive element 70 and the second conductive element 80, thereby connecting the resistance wire 90 into the circuit via the first conductive element 70 and the second conductive element 80. Furthermore, both the first conductive element 70 and the second conductive element 80 are connected to the support member 50 and extend from the side plate 12 away from the bottom plate 11. The extended portions can be used for installation with other components, thereby achieving the installation and fixation of the pre-charged resistor.

[0105] Specifically, the first conductive element 70 and the second conductive element 80 extend from the side of the side plate 12 away from the bottom plate 11. In other words, the first conductive element 70 and the second conductive element 80 protrude from the housing 10, facilitating connection to other components, such as a circuit board. The first conductive element 70 and the second conductive element 80 can be mechanically fixed to the circuit board by soldering, while simultaneously achieving electrical connection. Thus, the first conductive element 70 and the second conductive element 80 serve both mechanical support and electrical connection functions for the resistance wire 90, achieving multiple uses from a single component.

[0106] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. 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.

[0107] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A pre-charge resistor, characterized by, The application relates to a pre-charging resistor. The pre-charging resistor comprises a shell (10), a resistance assembly (20), and a heat-diffusing layer (30). The shell (10) comprises a bottom plate (11) and a side plate (12), the side plate (12) is arranged along a first direction (X), the bottom plate (11) is arranged on one side of the side plate (12) along the first direction (X), and the side plate (12) is connected with the bottom plate (11) to form a containing cavity (13). The resistance assembly (20) is arranged in the containing cavity (13).

2. The pre-charge resistor of claim 1, wherein, The heat-diffusing layer (30) is arranged on one side of the side plate (12) facing the resistance assembly (20), and the heat-diffusing layer (30) covers the side plate (12).

3. The pre-charge resistor of claim 1, wherein, The heat-diffusing layer (30) is also arranged on one side of the bottom plate (11) facing the resistance assembly (20), and the heat-diffusing layer (30) covers the bottom plate (11).

4. The pre-charge resistor of claim 1, wherein, The ratio of the wall thickness of the side plate (12) to the thickness of the heat-diffusing layer (30) is 1-5. The heat-diffusing layer (30) comprises a first sub-layer (31) and a second sub-layer (32) arranged along a second direction (Y), the second sub-layer (32) is connected to at least one side of the first sub-layer (31) along the second direction (Y).

5. The pre-charge resistor of claim 4, wherein, The first sub-layer (31) is projected along a third direction (Z) to form a first projection area, the resistance assembly (20) is projected along the third direction (Z) to form a second projection area, the second projection area falls within the first projection area, and the first direction (X), the second direction (Y) and the third direction (Z) are perpendicular to each other.

6. The pre-charge resistor of claim 5, wherein, The thickness of the first sub-layer (31) along the third direction (Z) is W1, the thickness of the second sub-layer (32) along the third direction (Z) is W2, and W1>W2 is satisfied.

7. The pre-charge resistor of claim 5, wherein, The first sub-layer (31) and the second sub-layer (32) satisfy 1 8. The precharge resistor of claim 1, wherein, The heat-diffusing layer (30) further comprises a transition layer (33) connecting the first sub-layer (31) and the second sub-layer (32), the thickness of the transition layer (33) along the third direction (Z) gradually decreases from the first sub-layer (31) to the second sub-layer (32).

9. The precharge resistor of claim 8, wherein, The pre-charging resistor further comprises a filling layer (40) arranged in the containing cavity (13), and the resistance assembly (20) is at least partially embedded in the filling layer (40).

10. The pre-charge resistor of claim 9, wherein, The thermal conductivity of the heat-diffusing layer (30) is less than the thermal conductivity of the filling layer (40). The thermal conductivity of the heat-diffusing layer (30) is 0.2 W / (m.K)-0.7 W / (m.K); and / or, 11. The pre-charge resistor according to any one of claims 1-10, wherein, The thermal conductivity of the filling layer (40) is 0.8 W / (m.K)-3.5 W / (m.K).

12. The pre-charge resistor of claim 11, wherein, The resistance assembly (20) comprises a support (50) and a resistance wire (90), the support (50) is arranged in the containing cavity (13), and the resistance wire (90) is arranged around the support (50). The resistance assembly (20) further comprises a heat-conducting layer (60) covering the surface of the support (50) and the resistance wire (90).

13. The pre-charge resistor of claim 11, wherein, The bottom plate (11) is provided with a mounting table (111), the mounting table (111) is provided with a mounting protrusion (112), the support piece (50) is provided with a supporting flange (51), the supporting flange (51) is provided with a mounting hole (52), and the mounting protrusion (112) is inserted into the mounting hole (52).

14. The pre-charge resistor of claim 11, wherein, The pre-charge resistor further comprises a first conductive piece (70) and a second conductive piece (80), the first conductive piece (70) and the second conductive piece (80) are respectively arranged at two ends of the support piece (50) and are connected with the support piece (50), and the first conductive piece (70) and the second conductive piece (80) are electrically connected with the resistance wire (90); The first conductive piece (70) and the second conductive piece (80) are arranged on a side of the side plate (12) away from the bottom plate (11), and the first conductive piece (70) and the second conductive piece (80) are used for mounting and fixing the pre-charge resistor.

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