Heatsink Assembly

Abstract

The disclosed heat sink assembly has a plurality of flow paths integrally formed along the internal longitudinal direction by extrusion molding, the spaces between the flow paths form solid portions, first and second surfaces at both ends in the longitudinal direction are open, and both ends of the flow paths include a heat sink spaced apart from the first and second surfaces, and end plugs that close the open first and second surfaces at both ends of the heat sink, with the first surface having both an inlet port through which the refrigerant flows in and an outlet port through which the refrigerant flows out, and the second surface forming a return flow path for the refrigerant.

Description

[Technical Field]

[0001] The present invention relates to a heat sink assembly that is attached to the bottom of a battery pack that includes a plurality of secondary batteries and promotes heat dissipation from the battery pack.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0071942, dated June 2, 2023, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference. [Background technology]

[0003] Unlike primary batteries, secondary batteries are rechargeable and have the potential to be small and have large capacities, and as such, they have been the subject of much research and development in recent years. Demand for secondary batteries as an energy source is rapidly increasing due to the increasing technological development and demand for mobile devices, as well as the emergence of electric vehicles and energy storage systems in response to modern demands for environmental protection.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries depending on the shape of the battery case. The electrode assembly installed inside the battery case of a secondary battery is a power generating element that can be charged and discharged and is made up of a laminated structure of electrodes and a separator.

[0005] Since secondary batteries are required to be used continuously for a long period of time, it is necessary to effectively control the heat generated during the charging and discharging process.If secondary batteries are not cooled smoothly, a positive feedback chain reaction will occur in which a rise in temperature causes an increase in current, and the increase in current causes another rise in temperature, ultimately leading to a catastrophic state of thermal runaway.

[0006] Heat sinks (also called cooling plates) through which a refrigerant flows are widely used to effectively dissipate heat generated by secondary batteries. Heat sinks are attached to the bottom of a group of multiple secondary batteries, such as a battery pack containing multiple secondary batteries, and perform a cooling function by absorbing heat generated inside the pack with a refrigerant and dissipating it to the outside.

[0007] Heat sinks can be divided into brazed and extruded heat sinks depending on their structure or manufacturing method. Brazed heat sinks are made by brazing two plates together to form flow channels, which allows for greater freedom in flow channel design, but has the disadvantage of reduced structural rigidity due to the deterioration of the material's physical properties. In contrast, extruded heat sinks, which are manufactured as a continuous body through extrusion molding, have the advantage of structural rigidity, but can only implement linear flow channels, resulting in many ports and the need for connecting pipes that take up space. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention aims to provide a heat sink assembly that is an extruded heat sink that does not require separate pipes for forming flow paths, occupies less space, has a simplified flow path configuration, reduces the number of parts, improves differential pressure, and can uniformly guide the flow rate of refrigerant through multiple flow paths.

[0009] However, the technical problems that the present invention aims to solve are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

[0010] The present invention relates to a heat sink assembly, in which a plurality of flow paths are integrally formed along an internal longitudinal direction by extrusion molding, spaces between the flow paths form solid portions, first and second surfaces at both longitudinal ends are open, and both ends of the flow paths include a heat sink spaced from the first and second surfaces, and end plugs that close the open first and second surfaces at both ends of the heat sink, respectively, and the first surface is provided with an inlet port through which a refrigerant flows in and an outlet port through which the refrigerant flows out, and the second surface forms a return flow path for the refrigerant.

[0011] In one embodiment of the present invention, the inlet passage connected to the inlet port may be arranged in a central region of the heat sink, the outlet ports may be provided in pairs, and the outlet passages connected to the outlet ports may be arranged on both sides of the inlet passage.

[0012] The end plugs may include an inlet plug that closes a first surface of the inlet flow passage, a pair of outlet plugs that close first surfaces of the outlet flow passage, and a return plug that closes a second surface of the return flow passage.

[0013] Meanwhile, the distances of the outlet channels from the first surface may gradually decrease as they approach the outlet port.

[0014] For example, the distance of the outlet passages from the first surface may decrease linearly as they approach the outlet port.

[0015] The return passage may be spaced a constant distance from the second surface.

[0016] The pressure loss acting on the refrigerant flowing through the return flow path on the second surface to each of the outlet flow paths is proportional to the overall length of the outlet flow path, thereby making the flow rate of the refrigerant flowing through each outlet flow path uniform.

[0017] In some embodiments, an expanded solid portion may be provided between the inlet passage and an outlet passage adjacent to the inlet passage.

[0018] The expanded solid portion may be mechanically coupled to a pack structure.

[0019] The cross-sectional area in the longitudinal direction formed by the space between the inlet plug and the inlet passage may be larger than the cross-sectional area in the longitudinal direction of the inlet passage.

[0020] The refrigerants flowing out from the pair of outlet ports can be joined together by a pipe member. [Effects of the Invention]

[0021] The heat sink assembly of the present invention having the above-described configuration has excellent structural rigidity because the heat sink is manufactured as a continuous body by extrusion molding, while the flow passages formed integrally with the heat sink are machined at both longitudinal ends, and end plugs close the open faces, thereby forming cooling flow passages divided into an inlet and an outlet.

[0022] As a result, the heat sink assembly of the present invention is based on an extruded heat sink, which has the advantage of structural rigidity, but does not require separate pipes to form flow paths, occupies less space, and the simplified flow path configuration reduces the number of parts, thereby improving differential pressure.Furthermore, by uniformly guiding the flow rate of the refrigerant flowing through multiple flow paths, stable cooling performance can be ensured across the entire heat dissipation area.

[0023] However, the technical effects that can be obtained by the present invention are not limited to the effects described above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0024] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention, and therefore the present invention should not be interpreted as being limited solely to the matters depicted in such drawings. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a view showing a heat sink assembly according to an embodiment of the present invention; [Figure 2] FIG. 2 is an exploded perspective view of the heat sink assembly of FIG. 1. [Figure 3] 1 is a diagram showing the structure of a heat sink in detail. [Figure 4] 2 is an enlarged view of part "A" in FIG. 1. [Figure 5] 2 is an enlarged view of part "B" in FIG. 1. [Figure 6] 2 is a diagram illustrating the overall flow of coolant in the heat sink assembly of FIG. 1. [Figure 7] 2 is a diagram showing an example of a pack structure being coupled to the heat sink assembly of FIG. 1; [Figure 8] 10 is a diagram showing an embodiment in which a pair of outlet ports are interconnected by a pipe member.

[0026] Because the present invention can be modified in various ways and can have various embodiments, specific embodiments will be described in detail below.

[0027] However, this is not intended to limit the invention to any particular embodiment, but rather to be understood as including all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

[0028] In the present invention, terms such as "comprise" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts or combinations thereof described in the specification, and may be understood as not precluding the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0029] Furthermore, in the present invention, when a layer, film, region, plate, or other portion is described as being "on" another portion, this includes not only the case where it is "directly on" the other portion, but also the case where there is another portion therebetween. Conversely, when a layer, film, region, plate, or other portion is described as being "under" the other portion, this includes not only the case where it is "directly under" the other portion, but also the case where there is another portion therebetween. Furthermore, in this application, being "located on" can include not only the case where it is located at the top, but also the case where it is located at the bottom.

[0030] The present invention relates to a heat sink assembly, in which a plurality of flow passages are integrally formed along an internal longitudinal direction by extrusion molding, the spaces between the flow passages form solid portions, first and second surfaces at both ends in the longitudinal direction are open, and both ends of the flow passages include a heat sink spaced from the first and second surfaces, and end plugs that close the open first and second surfaces at both ends of the heat sink, respectively, and the first surface is provided with an inlet port and an outlet port through which a refrigerant flows in and out, respectively, and the second surface forms a return flow passage for the refrigerant.

[0031] The heat sink assembly of the present invention having the above-described configuration has excellent structural rigidity because the heat sink is manufactured as a continuous body by extrusion molding, while the cooling flow passages formed integrally with the heat sink are machined at both longitudinal ends and end plugs close the open faces, thereby forming cooling flow passages divided into an inlet and an outlet.

[0032] As a result, the heat sink assembly of the present invention is based on an extruded heat sink, which has the advantage of structural rigidity, but does not require a separate pipe for forming a flow path, occupies less space, and has a simplified flow path configuration that reduces the number of parts, thereby improving differential pressure.

[0033] Hereinafter, specific embodiments of the heat sink assembly 10 of the present invention will be described in detail with reference to the accompanying drawings. For reference, the directions of front, back, up, down, left, and right used in the following description to designate relative positions are intended to aid in understanding the invention, and unless otherwise specified, are based on the directions shown in the drawings.

[0034] (First embodiment) FIG. 1 is a diagram showing a heat sink assembly 10 according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of the heat sink assembly 10 of FIG. 1, and FIG. 3 is a diagram showing the structure of the heat sink 100 in detail.

[0035] The heat sink assembly 10 of the present invention includes a heat sink 100 manufactured using an extrusion molding method and a plurality of end plugs 200. The open faces of the heat sink 100 are the faces at both ends of the longitudinal direction L, and for convenience of explanation, the two open faces are referred to as the first face 130 and the second face 140, respectively. Here, the longitudinal direction L refers to the extrusion direction of the heat sink 100, i.e., the direction in which the plurality of channels 110 formed in the hollow portion extend, and the width direction W refers to the direction perpendicular to the longitudinal direction L on a plane in which the plurality of channels 110 are spaced apart.

[0036] The heat sink 100 is manufactured from an extrusion product in which a plurality of flow channels 110 are integrally formed along the internal longitudinal direction L by extrusion molding. The plurality of flow channels 110 through which the refrigerant flows are hollow portions formed along the longitudinal direction L, and the spaces between the flow channels 110 form solid portions 120. A first surface 130 and a second surface 140 at both ends of the heat sink 100 in the longitudinal direction L are open due to the characteristics of the extrusion molded product.

[0037] 3 shows the structure of the flow channels 110 in more detail. The plurality of flow channels 110 extend in the longitudinal direction L between the first surface 130 and the second surface 140, and both ends of each channel are spaced a predetermined distance from the first surface 130 and the second surface 140. The distance at which the flow channels 110 are spaced from the first surface 130 and the second surface 140 can be freely designed by a cutting process that removes the hollow portions of the flow channels 110 and the solid portion 120 therebetween. In addition, by removing both the flow channels 110 and the solid portion 120 therebetween, the depth at which the end plug 200 is inserted is ensured.

[0038] The end plugs 200 close the open first and second surfaces 130 and 140 of the heat sink 100, respectively. The end plugs 200 have a thickness and width suitable for insertion into the openings on the first and second surfaces 130 and 140 of the heat sink 100. Once inserted into the heat sink 100, the end plugs 200 can be hermetically joined by welding, for example, friction stir welding. When the weld depths of the friction stir welding performed on the top and bottom surfaces of the heat sink 100 overlap, weld surfaces are formed on all four sides of the end plug 200, completing the seal.

[0039] Since the plurality of flow paths 110 extend in the longitudinal direction L and the first surface 130 and the second surface 140 are sealed by the end plugs 200, the positions of the ports 300 through which the refrigerant flows in and out can be appropriately selected to allow the refrigerant to flow throughout the entire heat transfer area of ​​the heat sink assembly 10. In the present invention, the inlet port 310 through which the refrigerant flows in and the outlet port 320 through which the refrigerant flows out are both disposed on the first surface 130, and the ports 300 are disposed on the second surface 140 to form the refrigerant return flow path 116 without a separate port.

[0040] 4 is an enlarged view of portion "A" of FIG. 1, and when viewed together with FIG. 3, the inlet flow passage 112 connected to the inlet port 310 is disposed in the central region of the heat sink 100, the outlet ports 320 are provided in pairs, and the outlet flow passages 114 connected to the outlet ports 320 are disposed on both sides of the inlet flow passage 112 in the width direction W. In the illustrated embodiment, two inlet flow passages 112 are provided, and the ends of the inlet flow passages 112 are connected to return flow passages 116 that extend along the second surface 140, and the return flow passages 116 are connected to the outlet flow passages 114 on both sides.

[0041] In one embodiment of the present invention, the end plug 200 that closes the first surface 130 includes an inlet plug 210 that closes the first surface 130 of the inlet passage 112, and a pair of outlet plugs 220 that close the first surface 130 of the outlet passage 114. A certain space is formed between the inlet plug 210 and the inlet passage 112, and an inlet port 310 is disposed in this space. As a result, the refrigerant that flows into the inlet port 310 fills the space upstream of the inlet passage 112 and then branches into each inlet passage 112 to flow uniformly. Similarly, the outlet port 320 is disposed in the space between the outlet plug 220 and the outlet passage 114.

[0042] The cross-sectional area in the longitudinal direction L formed by the space between the inlet plug 210 and the inlet passages 112 may be larger than the entire cross-sectional area of ​​the inlet passages 112 in the longitudinal direction L. The space between the inlet plug 210 and the inlet passages 112 forms a kind of storage space, which allows the refrigerant introduced into the multiple inlet passages 112 to flow uniformly and smoothly.

[0043] 5 is an enlarged view of portion "B" in FIG. 1, showing the return flow passage 116. The second surface 140 of the heat sink 100 is closed by a return plug 230, and the end of each flow passage 110, i.e., the end of each flow passage 110 facing the second surface 140, is also spaced a predetermined distance from the return plug 230, and the space thus formed forms the return flow passage 116. The return flow passage 116 may be formed as a flow passage 110 whose distance from the second surface 140 is constant, i.e., whose cross-sectional area does not change substantially.

[0044] Meanwhile, in one embodiment of the present invention, one end of the outlet flow passage 114 directly connected to the outlet port 320 may be formed differently from the inlet flow passage 112 and the return flow passage 116. As shown in Figures 3 and 4, the distance between the outlet flow passages 114 and the first surface 130 may gradually decrease as the outlet flow passages 114 approach the outlet port 320. For example, the distance between the outlet flow passages 114 and the first surface 130 may linearly decrease as the outlet flow passages 114 approach the outlet port 320.

[0045] In the heat sink assembly 10 of the present invention, the flow area occupied by the outlet passage 114 is overwhelmingly larger than the flow areas formed by the inlet passage 112 and the return passage 116. This is because when the refrigerant flows into the heat sink 100, the flow velocity in the outlet passage 114 is significantly reduced, allowing heat to be transferred over a sufficient period of time. In other words, the flow distribution of the refrigerant is also most significantly affected by the outlet passage 114.

[0046] Due to flow characteristics, the closer the inlet flow path 112 is to the outlet flow path 114, the lower the pressure loss that occurs before the refrigerant enters. Therefore, the closer the inlet flow path 112 is to the outlet flow path 114, the more refrigerant tends to be introduced. Therefore, from the perspective of the illustrated heat sink assembly 10, the refrigerant is concentrated in the outlet flow path 114 near the center, which reduces heat transfer performance in the outer region. If the cooling performance of the heat sink assembly 10 varies depending on the region, it is more likely that localized high-temperature areas will occur, which will adversely affect the performance of the battery pack. This variation in cooling performance can be resolved by uniformly guiding the flow rate of the refrigerant flowing through each outlet flow path 114.

[0047] 6 is a diagram illustrating the overall flow of refrigerant in the heat sink assembly 10 of FIG. 1. As described above, the outlet passages 114 are configured such that the distance from the first surface 130 gradually decreases toward the outlet port 320. In other words, the length of each of the outlet passages 114 gradually increases toward the outlet port 320, i.e., toward the inlet passage 112. The pressure loss acting on the refrigerant in each outlet passage 114 is proportional to the length of each outlet passage 114 that forms a boundary layer with the fluid. Therefore, the pressure loss acting on the refrigerant flowing through the return flow path 116 on the second surface 140 to each outlet flow path 114 is proportional to the overall length of the outlet flow path 114, so the flow rate of the refrigerant gradually increases toward the outer outlet flow path 114.As a result, the closer the inlet flow path 112 is to the outlet flow path 114, the more refrigerant is introduced, which offsets the tendency, and the flow rate of the refrigerant flowing through each outlet flow path 114 becomes uniform.

[0048] As described above, the heat sink assembly 10 according to the present invention allows the refrigerant to flow at a uniform flow rate over the entire area of ​​the heat sink 100, thereby providing uniform cooling characteristics without being concentrated in a specific area.

[0049] (Second embodiment) 7 is a diagram showing an example of a pack structure 400 being coupled to the heat sink assembly 10 of FIG. 1. Referring to FIGS. 1 to 5, an expanded solid portion 122 is provided between the inlet flow passage 112 and the outlet flow passage 114 adjacent to the inlet flow passage 112. Here, the expanded solid portion 122 refers to a solid portion 122 that is wider than the solid portion 120 that forms the space between the flow passages 110, for example. For example, the expanded solid portion 122 can be provided by forming a solid portion between the inlet flow passage 112 and the outlet flow passage 114 that has a width that skips approximately one flow passage space.

[0050] 3 and 6, since the flow channels 110 are formed over almost the entire surface of the heat sink 100, in order to couple the heat sink assembly 10 of the present invention to a battery pack, it is necessary to provide a coupling structure that can maintain sufficient mechanical strength without damaging the flow channels 110. For this purpose, an expanded solid portion 122 is provided along the central longitudinal direction L of the heat sink assembly 10.

[0051] For example, as shown in FIG. 7, a plurality of screw holes 124 may be drilled along the expanded solid portion 122, and a pack structure 400 (e.g., a center frame) may be firmly coupled to the heat sink assembly 10 by bolts 410 fastened to the screw holes 124.

[0052] 8 is a view showing an embodiment in which a pair of outlet ports 320 are interconnected by a pipe member 330. The present invention is provided with two outlet ports 320 for flow path structure. Therefore, two external pipes are required to be connected to the outlet ports 320. However, by connecting the pair of outlet ports 320 with a "Y"- or "T"-shaped pipe member 330 as shown in FIG. 8, the refrigerant flowing from the two streams can be merged into one. The pipe member 330 that merges the two outlet ports 320 into one further simplifies the external piping structure that must be provided for the heat sink assembly 10.

[0053] The present invention has been described in more detail above through the drawings and embodiments, etc. However, the configurations described in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore, there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

[0054] 10: Heat sink assembly 100: Heat sink 110: Flow path 112: Inlet flow path 114: Outlet flow path 116: Return flow path 120: Solid part 122: Expanded solid section 124: screw hole 130: 1st page 140:Second side 200: End plug 210: Inlet plug 220: Outlet plug 230: Return plug 300:Port 310: Inlet port 320: Outlet port 330: Pipe member 400: Pack Structure 410: Bolt L: Longitudinal direction W: Width direction

Claims

1. a heat sink in which a plurality of flow paths are integrally formed along an internal longitudinal direction by extrusion molding, spaces between the flow paths form solid portions, first and second surfaces at both ends in the longitudinal direction are open, and both ends of the flow paths are spaced apart from the first and second surfaces; and end plugs for closing the first and second open surfaces of the heat sink, respectively; An inlet port through which the refrigerant flows and an outlet port through which the refrigerant flows are both arranged on the first surface, A heat sink assembly, wherein a coolant return flow path is formed on the second surface.

2. an inlet passage connected to the inlet port is disposed in a central region of the heat sink; The heat sink assembly according to claim 1 , wherein the outlet ports are provided in pairs, and outlet passages connected to the outlet ports are disposed on both sides of the inlet passage.

3. The end plug is an inlet plug closing a first surface of the inlet passage; a pair of outlet plugs closing a first side of the outlet passage; and The heat sink assembly of claim 2 including a return plug closing a second side of the return passage.

4. The plurality of outlet channels include: The heat sink assembly of claim 2 , wherein the distance from the first surface gradually decreases toward the outlet port side.

5. The plurality of outlet channels include: The heat sink assembly of claim 4 , wherein the distance from the first surface decreases linearly toward the outlet port side.

6. The return flow path is The heat sink assembly of claim 4 , wherein the distance from the second surface is constant.

7. The plurality of flow paths are a pressure loss acting on the refrigerant flowing through the return flow path on the second surface and into each of the outlet flow paths is proportional to the overall length of the outlet flow paths; 7. The heat sink assembly of claim 6, wherein the flow rate of the coolant through each outlet passage is uniform.

8. 3. The heat sink assembly of claim 2, wherein an expanded solid portion is provided between the inlet passage and the outlet passage adjacent to the inlet passage.

9. The heat sink assembly of claim 8 , wherein a puck structure is mechanically coupled to the expanded solid portion.

10. 4. The heat sink assembly of claim 3, wherein a longitudinal cross-sectional area defined by a space between the inlet plug and the inlet passage is greater than a longitudinal cross-sectional area of ​​the inlet passage.

11. 3. The heat sink assembly according to claim 2, wherein the coolant flowing out from each of the pair of outlet ports is joined together by a pipe member.

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