Forming process of die-casting aluminum shell embedded water pipe, die-casting module and product

Abstract

The invention discloses a forming process of a die-casting aluminum shell embedded water pipe, a die-casting module and a product. According to the process, a pretreated water pipe serves as an insert to be placed in a mold cavity and is accurately fixed through a positioning hole, a limiting block and a core-pulling sliding block in a mold; and then molten aluminum liquid is injected into the cavity under high pressure, the molten aluminum liquid wraps the water pipe, metal fusion is achieved, and an integrally-formed product is obtained after pressure maintaining and cooling. The special die-casting module ensures stable positioning of the water pipe. In the product, the aluminum shell and the water pipe are metallurgically bonded, no adhesive is used, and the product has the advantages of being high in structural strength, good in sealing performance, high in production efficiency and excellent in consistency.

Description

Technical Field

[0001] This application relates to the technical field of heat dissipation aluminum shells, and more specifically, to a process for inserting water pipes into a die-cast aluminum shell. Background Technology

[0002] As a key component that houses internal heat-generating elements and efficiently dissipates heat through an internal circulating water system, aluminum heat sinks are widely used in various electronic devices, automotive parts, industrial controllers, and other fields. Their core function is to rapidly dissipate heat generated by internal components through a cooling medium (usually water or coolant) flowing through the water channels embedded in the casing, while ensuring structural strength, thereby maintaining stable operation of the equipment at a safe temperature.

[0003] In traditional manufacturing processes, a split aluminum shell structure is commonly used to embed water pipes. This process typically involves the following steps: First, the aluminum shell is designed and machined into two or more independent shell sections; second, pre-formed channels for embedding water pipes are machined (e.g., milled) on the inner surface or mating surface of one of the shell sections; next, a specialized thermally conductive adhesive or sealant is applied to these channels; then, the pre-fabricated water pipes (usually copper or aluminum) are pressed into the adhesive-coated channels; finally, the other shell section is aligned and covered, and the multiple split sections are assembled and sealed into a complete shell using bolts, welding, or bonding, ensuring the water pipe interfaces are accessible.

[0004] However, the aforementioned traditional split-pipe installation process has long suffered from several inherent defects in actual production and application, mainly including: The process is complex and inefficient: it involves multiple discrete processing and assembly steps, including separate processing, grooving, gluing, manual or semi-automatic installation of water pipes, alignment and splicing, and final fastening and sealing. The numerous steps and high precision requirements make highly automated production difficult, resulting in low overall production efficiency and high production costs.

[0005] Connection reliability relies on auxiliary materials, which carries the risk of failure: the fixing and sealing of water pipes depend entirely on the performance of the adhesive. Adhesives may suffer from uneven application, insufficient curing, aging, or inadequate heat and corrosion resistance. Under prolonged conditions of thermal cycling, vibration, and corrosive media, the adhesive interface is prone to performance degradation, leading to a decrease in the bond strength between the water pipe and the aluminum shell, and even coolant leakage, severely impacting the reliability of the heat dissipation system and the safe operation of the equipment.

[0006] There are weaknesses in structural strength and sealing: the joints between the components (especially the complex groove areas designed to accommodate water pipes) are inherently weak points in the structure. Relying on later splicing and sealing, the overall structural strength and long-term sealing performance are often inferior to those of a one-piece molded component. When subjected to mechanical or thermal stress, the splicing interface may experience slight deformation or leakage.

[0007] Product consistency is difficult to guarantee: Due to the heavy reliance on manual operations (such as gluing and installation), the control of process parameters is difficult, and different batches of products, or even products from the same batch, may have differences in bonding quality, sealing performance and heat dissipation performance, posing challenges to product consistency and stability.

[0008] Therefore, there is an urgent need in the field for a new method for manufacturing heat-dissipating aluminum shells that can simplify the process, improve reliability, optimize heat dissipation performance, and reduce costs. This application is proposed to solve the above-mentioned technical problems. Summary of the Invention

[0009] To address the problems of low production efficiency, failure risk, poor structural strength and sealing performance, and poor product consistency in traditional split-type water pipe inlay processes, this application provides a molding process, die-casting module, and product for die-cast aluminum shell water pipe inlays.

[0010] The first aspect of this application proposes a molding process for a die-cast aluminum shell inlaid with a water pipe, which adopts the following technical solution: A molding process for a die-cast aluminum shell inlaid water pipe includes the following steps: S1. Pre-treatment and placement of water pipes: Select a pre-shaped water pipe and clean its surface; then, place the treated water pipe as an insert into the designated position inside the cavity of the die-casting mold. S2. Mold closing and water pipe clamping and fixing: Start the die casting machine and drive the moving mold and fixed mold to close; during or after the mold closing process, the two ends and the body of the water pipe are mechanically clamped and positioned by the core pulling mechanism and positioning components built into the mold to prevent displacement or floating during the subsequent aluminum liquid filling process; S3. Aluminum Molten Injection and High-Pressure Forming: Using a die-casting machine, the aluminum alloy raw material is heated to 660℃±15℃ to form molten aluminum; the mold temperature is controlled to be maintained at 210℃±20℃; through the die-casting machine punch with a punch diameter of φ140mm, the molten aluminum is injected into the mold cavity at high speed according to the set multi-segment injection curve; the injection curve parameters include: three-speed position 510mm±10mm, three-speed valve opening 55%±5%, pressure boosting trigger position 580mm±10mm, pressure boosting valve opening 15%, injection flow rate set to 80%, and total system pressure opening 14.5MPa; the molten aluminum rapidly fills the cavity under high pressure and wraps around the pre-placed water pipe, achieving metal fusion with the water pipe; S4. Holding pressure, cooling and mold opening: After the aluminum molten metal is filled, it enters a holding pressure stage lasting 10 seconds ± 1.0 seconds to compensate for shrinkage; then it enters a cooling stage lasting 10 seconds ± 1.0 seconds to allow the product to initially solidify; after cooling, the die-casting machine opens the mold, and the moving mold separates from the fixed mold. S5. Product Ejection and Post-processing: After mold opening, the ejection mechanism of the die-casting machine operates, ejecting the aluminum shell casting that has wrapped the water pipe, along with the stub, from the moving mold; the thickness of the stub is controlled at 25mm±5mm; the entire product production cycle is controlled at 145 seconds±10 seconds; finally, the stub is removed to obtain the part that is integrally die-cast with the aluminum shell and water pipe.

[0011] Preferably, in step S1, the surface cleaning treatment of the water pipe includes degreasing, deoxidation, and drying processes to ensure the bonding quality between the aluminum molten metal and the outer wall of the water pipe.

[0012] Preferably, in step S2, the positioning of the water pipe by the mold is achieved by the following structure: on the fixed mold side or the moving mold side of the mold, there is a contoured groove or positioning sleeve that matches the shape of the end of the water pipe, which is used to radially limit the end of the water pipe; at the same time, on the cavity sidewall corresponding to the direction of the water pipe, there are multiple limiting blocks, which are used to support the water pipe body and prevent it from swaying.

[0013] Preferably, the core-pulling mechanism includes a slider disposed at the protruding end of the water pipe opening. The slider is driven and locked by the inclined guide post when the mold is closed, thereby clamping and fixing the water pipe axially.

[0014] Preferably, the injection process also includes follow-up stop position control, set to 760mm±15mm, for precise control of the end point of the punch stroke.

[0015] Secondly, this application proposes a die-casting module, which adopts the following technical solution: Preferably, a die-casting mold includes a fixed mold, a movable mold, and an ejection mechanism, wherein the fixed mold and the movable mold together form a cavity for forming an aluminum shell; the mold further includes a positioning assembly for fixing a water pipe insert, the positioning assembly comprising: An end positioning cavity is set on the cavity to accommodate the end of the water pipe; Multiple pipe body limiting blocks are arranged on the side wall of the cavity along the direction of the water pipe; A core-pulling slider mechanism corresponding to at least one end of the water pipe, the core-pulling slider mechanism being able to lock during mold closing to fix the axial position of the water pipe.

[0016] Preferably, the tube body limiting block is a protruding structure with an arc-shaped contact surface adapted to the outer diameter of the water pipe. Its height is designed to ensure that after the water pipe is placed, a uniform aluminum liquid filling channel is formed between the tube body and the inner wall of the cavity.

[0017] Thirdly, this application proposes a die-cast aluminum shell water pipe product, which adopts the following technical solution: A die-cast aluminum shell water pipe product includes an aluminum shell base and a water pipe. The aluminum shell base and the outer wall of the water pipe are directly bonded to each other by die casting. The water pipe is completely or partially encased in the aluminum shell base, and its opening is exposed from a designated position in the aluminum shell to connect to an external pipeline.

[0018] In summary, this application includes at least one of the following beneficial technical effects: 1. By placing the water pipe directly into the die-casting mold cavity as an insert, the aluminum shell base and the water pipe are formed simultaneously in a single die-casting process, eliminating multiple steps such as separate processing, grooving, gluing, assembly, and subsequent fastening in traditional processes. Using a die-casting machine and optimized process parameters, highly integrated and automated production is achieved, significantly improving production efficiency and product consistency while reducing production costs.

[0019] 2. Molten aluminum fills and coats the outer wall of the water pipe under high pressure, achieving direct fusion bonding between the metals and completely avoiding the reliance on adhesives in traditional processes. This not only eliminates the risk of decreased bonding strength and leakage caused by adhesive aging, unevenness, and insufficient heat and corrosion resistance, but also creates a dense metallurgical interface between the water pipe and the aluminum shell, maintaining extremely high structural integrity and sealing reliability even under long-term thermal cycling, vibration, and corrosive environments.

[0020] 3. The one-piece die-casting process creates a continuous, integral structure between the aluminum shell and the water pipe, eliminating the need for separate splicing interfaces and adhesive layers. This eliminates structural weaknesses caused by grooves and seams in traditional processes. The product has a stronger load-bearing capacity under mechanical and thermal stress, and its overall rigidity and durability are fundamentally improved.

[0021] 4. By using the positioning cavity, limiting block and core-pulling slider mechanism built into the mold, the water pipe is accurately and stably positioned in the mold cavity. Combined with optimized die-casting process parameters, the positional accuracy, connection state and sealing performance of the water pipe in each product are highly consistent, which greatly improves the quality stability of mass-produced products.

[0022] 5. The special die-casting mold has the functions of water pipe end positioning, pipe body limiting and axial locking, which effectively prevents water pipe displacement during the filling process; the precise control of multi-segment injection curves and process parameters ensures that the aluminum liquid can fill and tightly wrap the water pipe, avoiding air entrapment or deviation, making the process highly feasible and repeatable. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a die-casting mold according to this embodiment.

[0024] Figure 2This is an exploded view of a die-casting mold according to this embodiment.

[0025] Figure 3 This is a structural schematic diagram of a die-cast aluminum shell water pipe product according to this embodiment.

[0026] Reference numerals in the attached drawings: 1. Fixed mold; 2. Moving mold; 3. Ejection mechanism; 4. Cavity; 5. Locating cavity; 6. Limiting block; 7. Core-pulling slider mechanism; 8. Aluminum shell base; 9. Water pipe; Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] This application discloses a molding process for a die-cast aluminum shell water pipe, a special die-casting mold for implementing the process, and the resulting integrally molded product.

[0029] A molding process for a die-cast aluminum shell inlaid water pipe includes the following steps: Step S1: Select a metal water pipe of a predetermined shape and size and perform a cleaning treatment on its surface, including degreasing, removing the oxide layer, and thorough drying, to ensure that the subsequent molten aluminum can achieve a high-quality bond with its outer wall. The pre-treated water pipe is used as an insert and is precisely placed into a pre-set position inside the cavity of the die-casting mold by the operator or automated device.

[0030] Step S2: Start the die-casting machine and drive the moving mold to move towards the fixed mold until it is fully closed. During and after mold closing, the mold's built-in specialized positioning components mechanically clamp and position the water pipe to prevent it from shifting or floating under the impact of high-pressure molten aluminum. The positioning assembly mainly consists of three parts: First, on the fixed mold side of the mold, a contoured groove or positioning sleeve is machined to precisely match the shape of the water pipe end, used for radial limiting of the water pipe end; Second, along the direction of the water pipe body in the cavity, multiple pipe body limiting blocks are set on the side wall of the cavity. These limiting blocks are protruding structures with arc-shaped contact surfaces adapted to the outer diameter of the water pipe. They support the pipe body and prevent swaying. Their height is carefully designed to ensure that after the water pipe is placed, a uniform aluminum liquid filling channel is formed between the pipe body and the inner wall of the cavity; Third, a core-pulling slider mechanism corresponding to at least one pipe end of the water pipe. This mechanism mainly consists of a slider and an inclined guide post that drives its movement. When the mold is closed, the inclined guide post drives the slider to move inward and lock, thereby clamping and fixing the water pipe end axially. Through the synergistic effect of the above-mentioned end positioning, pipe body limiting, and axial locking, the water pipe is firmly and precisely fixed in the cavity before filling.

[0031] Step S3: Select a die-casting machine with a clamping force of 1250 tons to ensure sufficient clamping force. Heat the ADC12 aluminum alloy raw material to 660℃±15℃ to melt it into molten aluminum, and stabilize the mold temperature at 210℃±20℃. Using a die-casting machine punch with a diameter of φ140mm, inject the molten aluminum into the mold cavity at high speed according to a precisely set multi-segment injection curve. Specific injection curve parameters include: the three-speed switching position is set at 510mm±10mm of the punch stroke, at which point the three-speed valve opening is 55%±5% to achieve high-speed filling; the pressure boosting trigger position is set at 580mm±10mm, with the pressure boosting valve opening at 15%, to establish extremely high pressure at the end of filling; the overall injection flow rate is set to 80%, and the total system pressure opening is 14.5MPa. In addition, the injection process also includes follow-up stop position control, set at 760mm±15mm, to precisely control the end point of the punch stroke. Under high pressure, the molten aluminum quickly fills the cavity and tightly wraps around the pre-fixed outer wall of the water pipe. Due to the high temperature and pressure, the molten aluminum and the outer wall of the water pipe achieve metal fusion.

[0032] Step S3: After the molten aluminum fills the cavity, the system enters a holding pressure stage lasting 10 seconds ± 1.0 seconds to allow the material to shrink within the cavity, ensuring the product is dense. This is followed by a cooling stage of 10 seconds ± 1.0 seconds to allow the aluminum casting to initially solidify and set. After cooling, the die-casting machine opens the mold, separating the moving mold from the fixed mold.

[0033] Step S5: After mold opening, the ejection mechanism of the die-casting machine begins to operate, ejecting the complete aluminum shell casting, which already encloses the water pipe, along with the sprue formed by the gating system, from the moving mold. The thickness of the sprue is controlled at 25mm ± 5mm to balance material utilization and shrinkage compensation. The entire production cycle from mold closing to ejection completion is controlled within 145 seconds ± 10 seconds. After subsequent cleaning processes such as sprue removal, the ejected part yields a die-cast part where the aluminum shell base and water pipe are integrally formed.

[0034] Reference Figure 1-2 A die-casting mold includes a fixed mold 1, a moving mold 2, and an ejection mechanism 3. When the fixed mold 1 and the moving mold 2 are closed, they together form a cavity 4 for forming an aluminum shell. The core feature of this mold is its positioning assembly for fixing the water pipe 9 insert. As described above, this assembly includes a positioning cavity 5 located at the upper end of the cavity 4, multiple pipe-body limiting blocks 6 arranged along the side wall of the cavity 4, and a core-pulling slider mechanism 7 corresponding to the pipe end of the water pipe 9. The core-pulling slider mechanism 7 can be locked by a guide post during mold closing, thereby fixing the axial position of the water pipe 9. The arc-shaped surface of the pipe-body limiting block 6 ensures that a uniform aluminum liquid flow channel can be formed around the water pipe 9 when it is suspended in the cavity 4.

[0035] Reference Figure 3 A die-cast aluminum shell with an embedded water pipe 9 is described. The aluminum shell substrate 8 and the outer wall of the water pipe 9 are directly fused together through a die-casting process. The water pipe 9 is completely or partially encased within the high-density aluminum shell substrate 8, with its opening protruding from a designated position on the aluminum shell for easy connection to external cooling pipes. Because this product is integrally molded, it features high structural strength, excellent heat dissipation performance, superior sealing reliability, and good consistency.

[0036] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A forming process for a die-cast aluminum shell inlaid water pipe, characterized in that, Includes the following steps: S1. Pre-treatment and placement of water pipes: Select a pre-shaped water pipe and clean its surface; then, place the treated water pipe as an insert into the designated position inside the cavity of the die-casting mold. S2. Mold closing and water pipe clamping and fixing: Start the die casting machine and drive the moving mold and fixed mold to close; during or after the mold closing process, the two ends and the body of the water pipe are mechanically clamped and positioned by the core pulling mechanism and positioning parts built into the mold to prevent displacement or floating during the subsequent aluminum liquid filling process; S3. Aluminum liquid injection and high pressure forming: Using a die casting machine, the aluminum alloy raw material is heated to 660℃±15℃ to form aluminum molten metal; the mold temperature is controlled to be maintained at 210℃±20℃. Aluminum molten metal is injected into the mold cavity at high speed through the die-casting machine punch according to a set multi-segment injection curve. The injection curve parameters include: three-speed position of 510mm±10mm, three-speed valve opening of 55%±5%, pressure boosting trigger position of 580mm±10mm, pressure boosting valve opening of 15%, injection flow rate set to 80%, and total system pressure opening of 14.5MPa. The aluminum molten metal rapidly fills the mold cavity under high pressure and wraps around the outer wall of a pre-placed water pipe, achieving metal fusion with the water pipe. S4. Holding pressure, cooling and mold opening: After the aluminum molten metal is filled, it enters a holding pressure stage lasting 10 seconds ± 1.0 seconds to compensate for shrinkage; then it enters a cooling stage lasting 10 seconds ± 1.0 seconds to allow the product to initially solidify; after cooling, the die-casting machine opens the mold, and the moving mold separates from the fixed mold. S5. Product Ejection and Post-processing: After mold opening, the ejection mechanism of the die-casting machine operates, ejecting the aluminum shell casting that has wrapped the water pipe, along with the stub, from the moving mold; the thickness of the stub is controlled at 25mm±5mm; the entire product production cycle is controlled at 145 seconds±10 seconds; finally, the stub is removed to obtain the part that is integrally die-cast with the aluminum shell and water pipe.

2. The forming process of a die-cast aluminum shell water pipe according to claim 1, characterized in that: In step S1, the surface cleaning treatment of the water pipe includes degreasing, deoxidation, and drying processes to ensure the bonding quality between the aluminum molten metal and the outer wall of the water pipe.

3. The forming process of a die-cast aluminum shell water pipe according to claim 1, characterized in that: In step S2, the positioning of the water pipe by the mold is specifically achieved through the following structure: on the fixed mold side or the moving mold side of the mold, there is a contoured groove or positioning sleeve that matches the shape of the end of the water pipe, which is used to radially limit the end of the water pipe; at the same time, on the cavity sidewall corresponding to the direction of the water pipe, there are multiple limiting blocks, which are used to support the water pipe body and prevent it from swaying.

4. The forming process of a die-cast aluminum shell water pipe according to claim 3, characterized in that: The core-pulling mechanism includes a slider disposed at the protruding end of the water pipe opening. The slider is driven and locked by the inclined guide post when the mold is closed, thereby clamping and fixing the water pipe axially.

5. The forming process of a die-cast aluminum shell water pipe according to claim 1, characterized in that: The injection process also includes follow-up stop position control, set at 760mm±15mm, to precisely control the end point of the punch stroke.

6. A die-casting mold specifically for carrying out the process described in any one of claims 1 to 5, characterized in that: The mold includes a fixed mold, a moving mold, and an ejection mechanism, wherein the fixed mold and the moving mold together form the cavity for forming the aluminum shell; the mold also includes a positioning assembly for fixing the water pipe insert, the positioning assembly comprising: An end positioning cavity is set on the cavity to accommodate the end of the water pipe; Multiple pipe body limiting blocks are arranged on the side wall of the cavity along the direction of the water pipe; A core-pulling slider mechanism corresponding to at least one end of the water pipe, the core-pulling slider mechanism being able to lock during mold closing to fix the axial position of the water pipe.

7. A die-casting mold according to claim 6, characterized in that: The tube body limiting block is a raised structure with an arc-shaped contact surface adapted to the outer diameter of the water pipe. Its height is designed to ensure that after the water pipe is placed, a uniform aluminum liquid filling channel is formed between the tube body and the inner wall of the cavity.

8. A die-cast aluminum shell water pipe product manufactured by the process described in any one of claims 1 to 5, characterized in that: A die-cast aluminum shell water pipe product includes an aluminum shell base and a water pipe. The aluminum shell base and the outer wall of the water pipe are directly bonded to each other by die casting. The water pipe is completely or partially encased in the aluminum shell base, and its opening is exposed from a designated position in the aluminum shell to connect to an external pipeline.

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