Processing method of aluminum die-casting battery pack cooling module

Abstract

The invention discloses a processing method of an aluminum die-casting battery pack cooling module, which comprises the following steps that a blank body of a bottom shell is prepared through an aluminum die-casting process, and the second side surface of the blank body is provided with latticed bulges; preparing an aluminum alloy cover plate; an aluminum alloy cover plate is placed on the first side face of the blank body; welding and packaging the aluminum alloy cover plate and the blank body by adopting friction welding to form an assembly body; the assembly is machined, the size is adjusted through allowance cutting, and the latticed protrusions are removed; carrying out surface insulation treatment on the machined assembly body; the invention has the advantages of simple processing method, low manufacturing cost and better product quality.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle battery packs, and in particular to a method for processing an aluminum die-casting battery pack cooling module. Background Art

[0002] With the rapid development of the new energy vehicle industry, thermal management technology of battery packs has become one of the key factors affecting vehicle performance and safety. Battery packs generate a lot of heat during operation. If the heat cannot be effectively dissipated, it will lead to a decline in battery performance, shortened life, and even cause safety accidents. Therefore, it is of great significance to develop efficient and reliable battery pack cooling plates.

[0003] Patent CN219321443U discloses a cooling plate for a new energy vehicle battery pack. The patent discloses a cooling plate composed of two first cooling plates and a second cooling plate of the same size. The two cooling plates are connected by a stir friction welding process. A water cooling zone is provided on the first cooling plate, and a first cooling water channel and a second cooling water channel are provided in the zone. The first cooling water channel and the second cooling water channel are prepared by an etching process. The cooling water channel of this cooling plate is prepared by an etching process, which increases the difficulty of processing, resulting in reduced production efficiency and poor product consistency.

[0004] Patent CN221613985U discloses a cooling device and a battery pack, wherein the cooling device comprises a liquid cooling plate and two connecting pieces, wherein a first layer cooling channel and a second layer cooling channel penetrating along a first direction are provided in the liquid cooling plate. The two connecting pieces are respectively assembled with the two ends of the liquid cooling plate, so that the penetrating liquid cooling plate is encapsulated to form a complete flow channel structure.

[0005] It can be seen that the traditional cooling plate of the battery pack of new energy vehicles has many shortcomings. First of all, it is usually formed by aluminum alloy machining, and its processing technology is complicated. It needs to use laser etching and other methods to process the flow channel, which not only increases the production cost, but also limits the improvement of production efficiency. Secondly, even if part of the structure adopts the die-casting process, there is still the problem of using fasteners and seals during the assembly process, which makes the structure more complicated and increases the difficulty and time cost of assembly. In addition, due to the complexity of processing and assembly, the consistency of the product is also poor.

[0006] These problems not only increase the manufacturing cost, but also affect the performance and reliability of the product. Therefore, the development of a cooling plate with simple structure, efficient manufacturing and reliable performance has become an urgent need for current technological development. Summary of the invention

[0007] In view of this, the technical problem to be solved by the present invention is to provide a processing method for a battery pack cooling module with simpler process, higher production efficiency and better quality stability. The technical core lies in preparing an integrated water-cooling plate by combining aluminum die-casting with friction welding, and avoiding surface defects caused by aluminum die-casting by designing the molding intermediate structure, thereby simplifying the production process, improving production efficiency and ensuring product quality, thereby providing a better solution for the thermal management of new energy vehicle battery packs.

[0008] The technical solution adopted by the present invention to solve the above technical problems is: a processing method of an aluminum die-cast battery pack cooling module, the aluminum die-cast battery pack cooling module comprises an aluminum die-cast bottom shell and an aluminum alloy cover plate; the first side of the bottom shell has a flow channel groove with an upper opening, the flow channel groove has a flow channel partition wall, and the side of the bottom shell has a water inlet and a water outlet connected to the flow channel groove; the aluminum alloy cover plate is arranged on the bottom shell and closes the flow channel groove; The processing method comprises the following steps: Step A: preparing a blank body of the bottom shell by an aluminum die-casting process, wherein the second side surface of the blank body has a grid-shaped protrusion; Step B: preparing the aluminum alloy cover plate; Step C: placing the aluminum alloy cover plate on the first side surface of the blank body; Step D: using friction welding to weld and package the aluminum alloy cover plate and the blank to form an assembly; Step E: machining the assembly to adjust the size and remove the grid-like protrusions by excess cutting; Step F: performing surface insulation treatment on the machined assembly.

[0009] The preferred technical solution adopted by the present invention to solve the above technical problem is: the aluminum alloy cover plate described in step B is prepared by an extrusion molding process.

[0010] The preferred technical solution adopted by the present invention to solve the above technical problem is: the surface insulation treatment in step F is prepared by electrophoresis or powder spraying process.

[0011] The preferred technical solution adopted by the present invention to solve the above technical problem is: the grid-like protrusions are uniform diamond-shaped grids.

[0012] The preferred technical solution adopted by the present invention to solve the above technical problem is: the width of the edges of the grid-shaped protrusions gradually decreases from the root to the end face, and the end face is a plane.

[0013] The preferred technical solution adopted by the present invention to solve the above technical problem is: the edge height of the grid-like protrusions is 0.3mm-0.5mm.

[0014] The preferred technical solution adopted by the present invention to solve the above technical problem is: Step F is prepared by a powder spraying process, and the step F includes the following sub-steps: Step F1: Bake to discharge the gas in the surface pores; Step F2: Spray a layer of primer on the surface to form a closed layer; Step F3: Spray flour to complete the surface treatment.

[0015] The preferred technical solution adopted by the present invention to solve the above technical problem is: before step D, the blank body is subjected to a flattening treatment, and the flattening treatment includes a mechanical shaping treatment and a heat treatment annealing process treatment in sequence, and the annealing temperature is controlled at 255-265°C.

[0016] The preferred technical solution adopted by the present invention to solve the above technical problem is: before step E, the assembly welded in step D is subjected to secondary mechanical shaping treatment to control the overall flatness.

[0017] Compared with the prior art, the advantages of the present invention are: first, the technology of integrated aluminum die casting and friction welding is adopted to reduce the traditional multi-part welding and assembly combination to the welding combination of two main parts. This design eliminates the complicated assembly process and the required fasteners and seals, greatly simplifies the production process and reduces the manufacturing cost.

[0018] Secondly, a grid-like protrusion is formed on the second side of the blank. When the molten aluminum fills the product cavity and passes through the groove on the mold, the molten aluminum will swirl in the groove, thereby trapping impurities on the surface of the molten aluminum and part of the gas in the cavity in the groove structure. This reduces the hole defect rate and impurity rate of the main body that needs to be retained later, thereby improving the quality of the internal part of the product.

[0019] Third, the design of the grid-like protrusions can not only enhance the structural strength of the blank before friction welding and reduce its own demolding deformation ability, but also increase the structural strength during and after friction welding, avoid product damage and reduce deformation, providing many conveniences for subsequent processes.

[0020] Fourth, the machining of excess cutting is placed after the friction welding step. This is because the friction welding operation itself may affect the dimensional accuracy of the product. After completing this step, the dimensional adjustment can ensure product quality. The additional grid-like protrusions can be removed during machining, which also avoids the addition of additional processes, thereby ensuring production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings and preferred embodiments, but those skilled in the art will appreciate that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be used as a limitation on the scope of the present invention. In addition, unless otherwise specified, the drawings are only schematically representing the composition or structure of the described objects and may contain exaggerated displays, and the drawings are not necessarily drawn to scale.

[0022] Figure 1 This is a schematic diagram of the cooling module for the aluminum die-cast battery pack; Figure 2 This is the exploded view of the cooling module of the aluminum die-cast battery pack; Figure 3 This is a schematic diagram of the blank body of the bottom shell of the aluminum die-casting battery pack cooling module; Figure 4 This is a schematic diagram of the blank forming in the aluminum die-casting battery pack cooling module; Figure 5 A schematic diagram of the grid-shaped raised edges in the cooling module of the aluminum die-cast battery pack; Figure 6 It is a schematic diagram of the mechanical shaping of the blank body and assembly in the aluminum die-casting battery pack cooling module; Figure 7 This is a flow chart of the processing method of the aluminum die-casting battery pack cooling module.

[0023] Reference numerals: bottom shell 1; aluminum alloy cover plate 2; flow channel groove 3; flow channel partition wall 4; water inlet 5; water outlet 6; Blank die-casting mold p; groove n; product cavity j; grid-shaped protrusion 7; edge 71; blank body m; root a; end face b; outer side surface c; reference plane d; cylinder 9. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It will be appreciated by those skilled in the art that these descriptions are only illustrative and exemplary and should not be construed as limiting the scope of protection of the present invention.

[0025] It should be noted that like reference numerals denote similar items in the following drawings, and thus, once an item is defined in one drawing, it will not be further defined or explained in the subsequent drawings.

[0026] like Figure 1-2 As shown, the aluminum die-cast battery pack cooling module includes an aluminum die-cast bottom shell 1 and an aluminum alloy cover plate 2. The first side of the bottom shell 1 has a flow channel 3 with an upper opening, and the flow channel 3 has a flow channel partition wall 4. The side of the bottom shell 1 has a water inlet 5 and a water outlet 6 connected to the flow channel. The aluminum alloy cover plate 2 is arranged on the bottom shell 1 and closes the flow channel 3.

[0027] like Figure 7 As shown, in this embodiment: a processing method for an aluminum die-casting battery pack cooling module includes the following steps: Step A: Figure 3 As shown, the blank body m of the bottom shell is prepared by an aluminum die-casting process, and the second side surface of the blank body has a grid-shaped protrusion 7.

[0028] Step B: preparing an aluminum alloy cover plate.

[0029] Step C: placing an aluminum alloy cover plate on the first side of the blank body.

[0030] Step D: friction welding is used to weld and package the aluminum alloy cover plate and the blank body to form an assembly.

[0031] Step E: Machining the assembly to adjust the size and remove the grid-like protrusions through excess cutting.

[0032] Step F: Perform surface insulation treatment on the machined assembly.

[0033] The cooling module of this embodiment adopts the technology of combining integrated aluminum die-casting and friction welding, which reduces the traditional multi-part welding and assembly combination to a welding combination of two main parts. This design eliminates the complex assembly process and the required fasteners and seals, greatly simplifies the production process, and reduces manufacturing costs. Friction welding is a solid-state connection process that achieves metal-to-metal connection through frictional heat and pressure. Compared with traditional bolt connections or sealing rings, friction welding has higher sealing and reliability, and effectively solves the problem of leakage caused by aging of sealing rings in traditional processes. At the same time, compared with traditional extrusion molding processes, it is also easier to form more complex flow channel structures, avoiding being limited to the design of linear flow channels.

[0034] Preferably, the friction welding process parameters of step D are: rotation speed 1250-1900rpm, axial pressure 2.5-5.0KN, friction diameter 12mm, friction time 845-855 seconds, and top forging pressure 2.5-5.0KN. This welding parameter ensures the welding strength while avoiding the thermal deformation of the product as much as possible, and is the optimal choice for welding the bottom shell and aluminum alloy cover of the aluminum die-casting battery pack cooling module.

[0035] Further preferably, the friction welding process is divided into an initial friction stage at a low speed and a final forging stage at a high speed, and the gradient speed is used to reduce the influence of heat input on the weld microstructure, ensure grain refinement in the weld area, and improve fatigue resistance.

[0036] For aluminum die-casting products, machining to adjust their size and trim burrs is a relatively common technical means. In this step, after removing the dense layer on the surface of the blank, defects such as internal pores are easily exposed on the surface, thus affecting the surface performance of the product.

[0037] like Figure 3-4 As shown, in this embodiment, the functional surface with high surface performance requirements is specially treated during the preparation of the blank body, so that it can meet the surface performance requirements of the subsequent process after machining. In step A, a grid-like protrusion 7 is formed on the second side of the blank body by setting a cross groove n on the blank die-casting mold p. When the aluminum liquid is filled into the product cavity j and passes through the groove n on the mold, the aluminum liquid will swirl in the groove, thereby entraining impurities on the surface of the aluminum liquid and part of the gas in the cavity in the groove structure. This reduces the hole defect rate and impurity rate of the main body part that needs to be retained later, thereby improving the quality of the product inside.

[0038] The machining of excess cutting is placed after the friction welding step because the friction welding operation itself may affect the dimensional accuracy of the product. The dimensional adjustment after completing this step can ensure the product quality. The additional grid-shaped protrusions can be removed during machining, which also avoids the addition of additional processes, thereby ensuring production efficiency.

[0039] Due to the design of the grid-like protrusions, not only the surface quality of the second side surface corresponding to the grid-like protrusions is significantly improved, but also the porosity of the entire die-casting is reduced because the die-casting gas has an additional escape channel. Therefore, after CNC processing to remove these structures, the surface quality of each surface, especially the second side surface of the bottom shell, is greatly improved, thereby avoiding pinhole defects in subsequent insulation treatment and affecting the insulation qualification rate.

[0040] This grid-like protrusion design has another advantage. Due to the characteristics of the friction welding process itself, the product will shrink and deform after cooling. The grid-like protrusion design can not only enhance the structural strength of the blank before friction welding to reduce its own deformation during demoulding, but also increase the structural strength during and after friction welding, avoid product damage and reduce deformation, providing many conveniences for subsequent processes.

[0041] Preferably, if Figure 3 As shown in , the grid-like protrusions are uniform diamond-shaped grids. Figure 5As shown, the ridge width of the grid-like protrusion 71 gradually decreases from the root a to the end face b, and the end face is a plane. The ridge height of the grid-like protrusion is 0.3mm-0.5mm. This design detail plays a vital role in the smoothness of the die-casting process and the uniformity of the product. The design in which the ridge width of the grid-like protrusion gradually decreases from the root to the end face makes its outer side surface c form a certain inclination angle with the reference plane d. This inclination greatly promotes the gas to enter the grid-like protrusion more smoothly during the die-casting process. As shown in the figure, when the aluminum liquid is filled into the product cavity, the aluminum liquid is injected horizontally, and its main filling direction is consistent with the reference plane, and the inclined transitional grid-like protrusion can effectively guide gas and impurities into its structure, thereby forming more gas escape channels inside the die casting. This design feature not only significantly reduces the porosity of the die casting, but also greatly improves the internal quality of the product.

[0042] The aluminum alloy cover plate is usually a flat plate-shaped component, and an aluminum alloy plate can be used. In a preferred embodiment, the aluminum alloy cover plate in step B is prepared by an extrusion molding process, so that some spoiler structures can be set on the aluminum alloy cover plate, thereby improving the heat dissipation effect.

[0043] In the process of die casting, surface insulation treatment is a crucial link. In step F, the surface insulation treatment is prepared by electrophoresis or powder spraying process. In order to improve the insulation performance and appearance quality of the die casting, the powder spraying process is preferably used for surface insulation treatment. The process specifically includes the following steps: Step F1: High temperature baking pretreatment: The die casting is baked at high temperature to effectively exhaust the gas in the pores on its surface. This step is crucial, as it ensures that the subsequent coating is closely integrated with the die casting substrate and avoids bubbles or peeling of the coating.

[0044] Step F2: Spraying primer to form a sealing layer: Spray a layer of primer on the surface of the die casting. This primer can quickly solidify and form a uniform sealing layer on the surface of the die casting. The main function of the sealing layer is to prevent harmful substances such as water and moisture from penetrating into the interior of the die casting, thereby further improving its insulation performance.

[0045] Step F3: Flour spraying to complete the surface treatment: Flour spraying is performed on the surface of the die casting. The flour layer not only provides the required insulation performance for the die casting, but also gives it a good appearance and texture. By precisely controlling the spraying thickness and uniformity, we ensure that the surface insulation treatment of each die casting can achieve the best effect.

[0046] In this embodiment, in order to ensure the quality of the blank body, a leveling process is preferably added before executing the key step D. This leveling process includes two key links: a mechanical shaping process and a subsequent heat treatment annealing process. First, the blank body undergoes a mechanical shaping process to preliminarily adjust its shape and flatness, laying a solid foundation for subsequent processing. Secondly, the blank body will enter the heat treatment stage for annealing. The annealing temperature is precisely controlled between 255-265°C. The selection of this temperature range is crucial, which can not only effectively remove the internal stress generated by the blank body during the previous processing process, but also avoid excessive temperature causing material performance degradation. Through annealing, the microstructure of the blank body is optimized, internal stress is removed, and its overall flatness and stability are further improved.

[0047] Due to the characteristics of the friction welding process itself, the product will shrink and deform after cooling, thus affecting the product size. Therefore, before step E, the assembly welded in step D is subjected to secondary mechanical shaping to control the overall flatness.

[0048] like Figure 6 As shown, the method of primary mechanical shaping and secondary mechanical shaping is as follows: first, the oil cylinder 9 is used to fix the two ends of the product, and then the middle position of the push cylinder is used to apply an upward force relative to the reverse bow direction to deform the structure upward. Maintain this state for 30 seconds to fully shape the product, and finally retract the push cylinders in turn, release the oil cylinders on both sides, and the product will return to a free state, and plastic deformation will occur so that the product is adjusted from a bent state to a straight state. Through the above-mentioned primary and secondary mechanical shaping processes, we can effectively control the overall flatness of the assembly and ensure that the product can still maintain the ideal size and shape after welding cooling.

[0049] The processing method of the aluminum die-casting battery pack cooling module provided by the present invention is introduced. The principle and implementation method of the present invention are explained in this article using specific examples. The description of the above embodiments is only used to help understand the present invention and its core ideas. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for processing an aluminum die-casting battery pack cooling module, characterized in that: The aluminum die-cast battery pack cooling module comprises an aluminum die-cast bottom shell and an aluminum alloy cover plate; the first side of the bottom shell has a flow channel groove with an upper opening, the flow channel groove has a flow channel partition wall, and the side of the bottom shell has a water inlet and a water outlet connected to the flow channel groove; the aluminum alloy cover plate is arranged on the bottom shell and closes the flow channel groove; The processing method comprises the following steps: Step A: preparing a blank body of the bottom shell by an aluminum die-casting process, wherein the second side surface of the blank body has a grid-shaped protrusion; Step B: preparing the aluminum alloy cover plate; Step C: placing the aluminum alloy cover plate on the first side surface of the blank body; Step D: using friction welding to weld and package the aluminum alloy cover plate and the blank to form an assembly; Step E: machining the assembly to adjust the size and remove the grid-like protrusions by excess cutting; Step F: performing surface insulation treatment on the machined assembly.

2. The method for processing an aluminum die-casting battery pack cooling module according to claim 1, characterized in that: The aluminum alloy cover plate described in step B is prepared by an extrusion molding process.

3. The method for processing an aluminum die-casting battery pack cooling module according to claim 1, characterized in that: In step F, the surface insulation treatment is prepared by electrophoresis or powder spraying process.

4. The method for processing an aluminum die-casting battery pack cooling module according to claim 1, characterized in that: The grid-shaped protrusions are uniform diamond-shaped grids.

5. The method for processing an aluminum die-casting battery pack cooling module according to claim 1, characterized in that: The width of the edges of the grid-shaped protrusions gradually decreases from the root to the end surface, and the end surface is a plane.

6. The method for processing an aluminum die-casting battery pack cooling module according to claim 1, characterized in that: The edge height of the grid-like protrusions is 0.3mm-0.5mm.

7. The method for processing an aluminum die-casting battery pack cooling module according to claim 1, characterized in that: Step F is prepared by a powder spraying process, and the step F comprises the following sub-steps: Step F1: Bake to discharge the gas in the surface pores; Step F2: Spray a layer of primer on the surface to form a closed layer; Step F3: Spray flour to complete the surface treatment.

8. The method for processing an aluminum die-casting battery pack cooling module according to claim 1, characterized in that: Before step D, the blank is subjected to a flattening treatment, wherein the flattening treatment includes a mechanical shaping treatment and a heat treatment annealing process in sequence, and the annealing temperature is controlled at 255-265°C.

9. The method for processing an aluminum die-casting battery pack cooling module according to claim 8, characterized in that: Before step E, the assembly welded in step D is subjected to secondary mechanical shaping.

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