Method for manufacturing a tube integrated aluminum alloy subframe

Abstract

The embodiment of the application discloses a preparation method of a pipeline integrated aluminum alloy subframe. The method comprises the following steps: S1, melting, preparing an aluminum alloy melt; S2, core making, preparing a sand core integrated with a pipeline through a sand core mold; S3, casting, placing the sand core in a metal mold to form a composite mold, pouring the aluminum alloy melt into the composite mold, and obtaining a subframe blank containing the sand core after solidification forming; S4, sand vibration, performing vibration treatment on the subframe blank to remove the sand core, and obtaining a subframe body blank with an internal cavity and an integrated pipeline; and S5, mechanical processing, performing mechanical processing on the subframe body blank, and obtaining a finished subframe. The preparation method of the pipeline integrated aluminum alloy subframe solves the problem of traditional pipeline occupying external space, and the pipeline is no longer exposed on the outer surface of the subframe, thereby avoiding interference and wear risk with surrounding components.

Description

Technical Field

[0001] This invention relates to the field of subframe technology, and specifically to a method for manufacturing a tubular integrated aluminum alloy subframe. Background Technology

[0002] As new energy vehicles place increasing demands on space utilization and lightweight design, the drawbacks of traditional piping layouts are becoming increasingly apparent. Currently, piping is typically fixed to the outer contour of the subframe using clips or bolts and runs along it. However, this method often uses Ø25mm piping, which encroaches on external space and is prone to interference with surrounding components in a compact chassis layout, leading to pipe wear or failure. Furthermore, to ensure reliable connections, approximately 20 fixing points are required, resulting in low assembly efficiency and increased vehicle weight. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, embodiments of the present invention propose a method for manufacturing a pipeline-integrated aluminum alloy subframe that avoids interference and wear risks with surrounding components and improves system reliability.

[0005] The method for preparing the pipeline-integrated aluminum alloy subframe according to an embodiment of the present invention includes the following steps: S1, smelting to prepare aluminum alloy melt; S2, core making to prepare a sand core with integrated pipelines using a sand core mold; S3, casting to place the sand core in a metal mold to form a composite mold, pouring aluminum alloy melt into the composite mold, and obtaining a subframe blank containing the sand core after solidification; S4, vibration to remove the sand core from the subframe blank, obtaining a subframe body blank with internal cavities and integrated pipelines; S5, machining to machine the subframe body blank to obtain the finished subframe.

[0006] The method for manufacturing the integrated aluminum alloy subframe with tubing in this invention solves the problem of traditional tubing occupying external space. The tubing is no longer exposed on the outer surface of the subframe, avoiding interference and wear risks with surrounding components and improving system reliability. Simultaneously, since the tubing is integrated inside the structure, the approximately 20 clips or bolts originally used to fix the tubing can be eliminated, significantly reducing assembly complexity and manufacturing costs, and effectively reducing the overall vehicle weight. Complex tubing routes (such as bends and branches) can be easily achieved through sand core molding, without being limited by traditional external layouts, further optimizing chassis space utilization.

[0007] In some embodiments, in step S1, the aluminum alloy melt is obtained by melting aluminum alloy ingots at 650°C.

[0008] In some embodiments, in step S2, the sand core is made of organic sand or inorganic sand material; In some embodiments, the conduit is made of metal and is integrally formed with the sand core during the core-making process.

[0009] In some embodiments, the conduit is made of aluminum or steel.

[0010] In some embodiments, in step S3, the subframe body is integrally formed by die casting or gravity casting. After forming, the pipeline is completely enclosed in the internal cavity of the subframe body and arranged along the subframe frame.

[0011] In some embodiments, in step S4, the vibration treatment employs high-frequency vibration to loosen and break the sand core, which is then discharged from inside the subframe body.

[0012] In some embodiments, in step S5, the machining includes machining quick-connect interfaces that communicate with pipelines at both ends of the subframe body.

[0013] In some embodiments, the quick-connect interface adopts a standardized interface form.

[0014] In some embodiments, the subframe body is a symmetrical frame structure, and the subframe body has a cavity with uniform wall thickness inside. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the subframe body of the pipeline-integrated aluminum alloy subframe manufacturing method according to an embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram of the pipe and sand core structure in the method for preparing the pipe-integrated aluminum alloy subframe according to an embodiment of the present invention.

[0017] Figure label: 1. Subframe body; 2. Piping; 3. Sand core. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0019] like Figure 1 and Figure 2As shown, the method for preparing the pipe-integrated aluminum alloy subframe according to an embodiment of the present invention includes the following steps: S1, melting, preparing aluminum alloy melt. S2, core making, preparing a sand core 3 with integrated pipes 2 using a sand core 3 mold. S3, casting, placing the sand core 3 in a metal mold to form a composite mold, pouring aluminum alloy melt into the composite mold, and obtaining a subframe blank containing the sand core 3 after solidification. S4, vibration treatment, vibrating the subframe blank to remove the sand core 3, obtaining a subframe body 1 blank with an internal cavity and integrated pipes 2. S5, machining, machining the subframe body 1 blank to obtain the finished subframe.

[0020] Exemplarily, the method for preparing the pipe-integrated aluminum alloy subframe of this invention utilizes the "sand core 3 casting" technology to integrate the traditionally independently arranged pipes 2 into the subframe body 1. First, an aluminum alloy melt is prepared, and a sand core 3 with the shape of the pipes 2 is manufactured using a sand core 3 mold. This sand core 3 is placed in a metal mold, and the aluminum alloy melt is poured in. After solidification, the sand core 3 is encased within the subframe blank. After the casting cools, the sand core 3 is removed through vibration treatment, thereby forming a complete hollow pipe 2 cavity integrated with the subframe inside the subframe. Finally, the finished product is obtained through machining, making the pipes 2 part of the subframe structure rather than an external accessory.

[0021] Compared with related technologies, the method for manufacturing the integrated aluminum alloy subframe with tubing in this invention solves the problem of traditional tubing 2 occupying external space. Tubing 2 is no longer exposed on the outer surface of the subframe, avoiding interference and wear risks with surrounding components and improving system reliability. Simultaneously, since tubing 2 is integrated inside the structure, the approximately 20 clips or bolts originally used to fix tubing 2 can be eliminated, significantly reducing assembly complexity and manufacturing costs, and effectively reducing the overall vehicle weight. Complex tubing routes (such as bends and branches) can be easily achieved through sand core molding 3, without being limited by traditional external layouts, further optimizing chassis space utilization.

[0022] In some embodiments, in step S1, the aluminum alloy melt is obtained by melting aluminum alloy ingots at 650°C.

[0023] For example, the method for preparing the pipeline-integrated aluminum alloy subframe of this invention uses pure, uniformly structured aluminum alloy ingots as raw materials and melts them at a specific temperature of 650°C. The specific temperature of 650°C falls above the solid-liquid two-phase region of most cast aluminum alloys and is within a range of relatively low overheating temperatures. This allows the aluminum alloy ingots to be completely melted and obtain sufficient fluidity to meet subsequent casting requirements, while avoiding excessively high melting temperatures that could lead to excessive hydrogen absorption, oxidation, and element loss in the melt.

[0024] In some embodiments, in step S2, the sand core 3 is made of organic sand or inorganic sand.

[0025] For example, the material of the sand core 3 in the preparation method of the pipeline integrated aluminum alloy subframe of this embodiment can be organic sand (such as furan resin sand) or inorganic sand (such as water glass sand). In the core-making process, a mixture of sand materials of corresponding materials is used to form a sand core 3 in the shape of an integrated pipeline 2 through a sand core 3 mold. Organic sand relies on resin binder to solidify and form strength, and gradually pyrolyzes and disintegrates during the high-temperature molten metal pouring process. Inorganic sand maintains its shape through chemical or physical solidification and maintains structural stability after pouring. Both types of sand core 3 can reliably form the cavity of the pipeline 2 during the casting stage, and are removed by a vibration sand process after pouring and solidification.

[0026] The organic sand material used in the preparation method of the pipeline integrated aluminum alloy subframe of this invention has excellent molding precision, the ability to replicate the complex pipeline 2 contour, and good collapsibility. It facilitates the rapid removal of the sand core 3 during the sand vibration stage, which can improve the surface smoothness of the inner cavity and the consistency of the pipeline 2 dimensions. The inorganic sand material significantly reduces the emission of harmful gases generated during the casting and curing process, thereby reducing environmental protection costs and occupational health risks.

[0027] In some embodiments, the conduit 2 is made of metal and is integrally formed with the sand core 3 during the core-making process.

[0028] In the method for preparing the integrated aluminum alloy subframe according to this invention, the pipes 2 are made of metal and are integrally formed with the sand core 3 during the core-making process in step S2. This means that when making the sand core 3, the pre-prepared metal pipes 2 (e.g., aluminum pipes, steel pipes, or stainless steel pipes) are placed as inserts in the sand core 3 mold, and then sand is filled and cured, so that the metal pipes 2 are wrapped and fixed inside the sand core 3. When the sand core 3 is placed in the metal mold and aluminum alloy melt is poured, the melt wraps the sand core 3 and the pre-embedded metal pipes 2 therein, forming a subframe blank.

[0029] In some embodiments, the pipe 2 is made of aluminum or steel.

[0030] For example, aluminum tubes, being part of the same aluminum alloy system as the subframe body 1, have similar coefficients of thermal expansion, which can reduce casting stress and the risk of interface thermal cracking. Steel tubes have higher strength and wear resistance, making them suitable for pipeline circuits 2 that withstand high pressure or high frequency fatigue conditions.

[0031] In some embodiments, in step S3, the subframe body 1 is integrally formed by die casting or gravity casting. After forming, the pipes 2 are completely enclosed in the internal cavity of the subframe body 1 and arranged along the subframe frame.

[0032] The manufacturing process of the integrated aluminum alloy subframe of this invention involves die casting or gravity casting. During the casting process, a sand core 3 with pre-embedded metal pipes 2 is placed in a metal mold cavity. Then, aluminum alloy melt is poured in by die casting, so that the melt completely encapsulates the sand core 3 and its internal pipes 2. After the casting solidifies and the sand is removed by vibration, the metal pipes 2 are encapsulated inside the subframe body 1 and are strictly arranged along the preset direction of the subframe frame to form an internal passage integrated with the structure.

[0033] The method for preparing the pipeline-integrated aluminum alloy subframe of this invention uses die casting or gravity casting to form an integral structure, so that the integrated pipeline 2 is completely embedded inside the subframe structure rather than exposed on the surface, which helps to eliminate the risk of interference between the pipeline 2 and surrounding components (such as control arms, half shafts, steering gears, etc.).

[0034] In some embodiments, in step S4, the vibration treatment employs high-frequency vibration to loosen and break the sand core 3 and discharge it from inside the subframe body 1.

[0035] The method for preparing the pipeline-integrated aluminum alloy subframe of this invention involves high-frequency vibration for sand treatment. When the subframe blank containing the sand core 3 is placed in a high-frequency vibration device, the high-frequency mechanical vibration acts on the entire casting. Due to the difference in elastic modulus, density, and damping characteristics between the sand core 3 and the aluminum alloy matrix, the high-frequency vibration will generate strong relative displacement and impact stress at the interface between the sand core 3 and the inner wall of the casting. This causes the originally solidified and bonded sand core 3 to rapidly generate microcracks and gradually expand, eventually leading to the sand core 3 loosening and breaking into fine particles or powder, which are discharged from the pipeline 2 cavity inside the subframe body 1 and the casting opening.

[0036] The method for manufacturing the integrated aluminum alloy subframe using high-frequency vibration in this invention allows for deep penetration into all corners of the complex inner cavity of the pipeline 2, including curved sections, branch nodes, and deep cavity areas. This avoids blockages or burr defects on the inner wall of the pipeline 2 caused by residual sand cores 3. At high vibration frequencies, the number of impacts per cycle is high, allowing the sand cores 3 to be thoroughly removed in a short time, significantly shortening the cycle time of the sand-removing process and improving production efficiency.

[0037] In some embodiments, in step S5, machining includes machining quick-connect interfaces that communicate with the pipes 2 at both ends of the subframe body 1.

[0038] For example, in the method for preparing the pipeline-integrated aluminum alloy subframe of the present invention, after the subframe body 1 obtains the cavity of the internal pipeline 2 through sand vibration, quick-connect interfaces that communicate with the internal integrated pipeline 2 are respectively processed at the front and rear ends of the subframe body 1 by machining (such as drilling, boring, tapping or milling). This makes it easy for the external pipeline 2 (such as brake oil pipe, coolant pipe or power steering pipe) to be directly and sealedly connected to the integrated pipeline 2 inside the subframe during vehicle assembly, without the need to use additional adapters or complex seals.

[0039] In some embodiments, the quick-connect interface adopts a standardized interface form.

[0040] For example, during the machining process in step S5, the quick-connect interfaces machined at the front and rear ends of the subframe body 1 and connected to the integrated pipeline 2 follow the industry-standard dimensions, sealing structures, and connection specifications. This means that the parameters such as the hole diameter, tolerance, sealing groove depth, and snap-fit ​​contour of the interface are all matched with the standardized quick-connect connectors commonly used in the market. The same subframe assembly can be adapted to standardized quick-connect connectors provided by different suppliers, without the need to redesign the interface for a specific connector, thus reducing the complexity of supply chain management and the risk of dependence on a single supplier.

[0041] In some embodiments, the subframe body 1 is a symmetrical frame structure, and the subframe body 1 has a cavity with uniform wall thickness inside.

[0042] For example, in the casting process design, by matching the sand core 3 with the metal mold, the subframe body 1 forms a symmetrical stress frame on the left and right sides or in the front and rear directions, and the wall thickness is kept highly consistent throughout the structure. This means that during the casting filling process, it is beneficial for the aluminum alloy melt to flow uniformly in the cavity, avoiding local overheating, cold shuts or shrinkage defects caused by sudden changes in wall thickness. In the solidification stage, the uniform wall thickness ensures that the cooling rate of the entire casting is consistent, reducing the risk of thermal stress concentration and deformation.

[0043] In the description of this invention, 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," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0045] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0047] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0048] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for manufacturing a tubular integrated aluminum alloy subframe, characterized in that, Includes the following steps: S1. Melting, preparing aluminum alloy melt; S2, Core making: A sand core (3) with integrated pipeline (2) is prepared by using a sand core (3) mold. S3, casting: placing the sand core (3) in a metal mold to form a composite mold, pouring aluminum alloy melt into the composite mold, and obtaining a subframe blank containing the sand core (3) after solidification. S4. Vibration treatment: Vibration treatment is applied to the subframe blank to remove the sand core (3) and obtain a subframe body (1) blank with an internal cavity and integrated pipeline (2). S5. Machining: Machining is performed on the subframe body (1) blank to obtain the finished subframe.

2. The method for manufacturing the pipeline-integrated aluminum alloy subframe according to claim 1, characterized in that, In step S1, the aluminum alloy melt is obtained by melting aluminum alloy ingots at 650°C.

3. The method for manufacturing the pipeline-integrated aluminum alloy subframe according to claim 1, characterized in that, In step S2, the sand core (3) is made of organic sand or inorganic sand.

4. The method for manufacturing the pipeline-integrated aluminum alloy subframe according to claim 1, characterized in that, The pipeline (2) is made of metal and is integrally formed with the sand core (3) during the core-making process.

5. The method for manufacturing the pipeline-integrated aluminum alloy subframe according to claim 4, characterized in that, The material of the pipeline (2) is aluminum or steel.

6. The method for manufacturing the pipeline-integrated aluminum alloy subframe according to claim 1, characterized in that, In step S3, the subframe body (1) is integrally formed by die casting or gravity casting. After forming, the pipeline (2) is completely enclosed in the internal cavity of the subframe body (1) and arranged along the subframe frame.

7. The method for manufacturing the pipeline-integrated aluminum alloy subframe according to claim 1, characterized in that, In step S4, the vibration treatment uses high-frequency vibration to loosen and break the sand core (3) and discharge it from inside the subframe body (1).

8. The method for preparing the pipeline-integrated aluminum alloy subframe according to claim 1, characterized in that, In step S5, the machining includes machining quick-connect interfaces that communicate with the pipeline (2) at both ends of the subframe body (1).

9. The method for manufacturing the pipeline-integrated aluminum alloy subframe according to claim 8, characterized in that, The quick-connect interface adopts a standardized interface form.

10. The method for manufacturing the pipeline-integrated aluminum alloy subframe according to claim 1, characterized in that, The subframe body (1) is a symmetrical frame structure, and the subframe body (1) has a cavity with uniform wall thickness inside.

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