Split type combined hub with resonant cavity and split preparation process of split type combined hub

Abstract

The invention belongs to the technical field of hubs, and discloses a split type combined hub with a resonant cavity and a split preparation process of the split type combined hub. Integrally forming a rim by adopting a semi-solid vacuum die-casting process; an annular groove is formed in the end face where the spoke and / or the rim are / is connected in a matched mode. The spoke and the rim are folded and welded into a whole through the friction stir welding technology, and the annular groove is sealed to form an annular resonant cavity integrated in the hub. Through split precision casting, the problems that dissimilar materials are poor in welding compatibility and a traditional spinning rim is difficult to integrate a complex structure are solved; the formed built-in annular resonant cavity can effectively reduce tire noise with specific frequency, realizes local light weight, and has the advantages of low defect rate, uniform performance and integration of noise reduction and light weight.

Description

Technical Field

[0001] This application belongs to the field of wheel hub technology, and more specifically, relates to a split-type combined wheel hub with a resonant cavity and its split manufacturing process. Background Technology

[0002] As a key safety component of automobiles, the wheel hub is responsible for bearing various loads and is one of the most important safety parts in a car. Currently, wheel hubs on the market are mainly divided into two categories: steel and aluminum. Among them, aluminum wheel hubs have gained widespread market recognition due to their superior comprehensive performance, including lightweight and safety, and are gradually replacing steel wheel hubs as a better choice. The manufacturing processes for aluminum alloy wheel hubs mainly include three types: casting, widely used in passenger vehicles; forging, often seen in high-end sports cars; and spinning technology, which is relatively less used in China. Currently, many automakers prefer to use casting technology to produce aluminum alloy wheel hubs, with low-pressure casting accounting for approximately 80% of my country's cast aluminum alloy wheel hub production.

[0003] Currently, most mainstream aluminum alloy wheels adopt a one-piece design. However, for automotive wheels with complex shapes and large dimensions, low-pressure casting is prone to defects such as shrinkage cavities, porosity, and air bubbles at the junction of the spokes and rim. Furthermore, the slow aluminum molten filling and mold opening and closing speeds limit production efficiency. In recent years, modular (or split-type) wheel technology has gradually emerged and become an important development direction. Modular wheels refer to decomposing the wheel structure into two core components: the spokes and the rim. These are manufactured independently and then assembled into a complete wheel through welding, bolting, and other methods. Modular wheels allow for the use of optimal materials and manufacturing processes for both the spokes and the rim, thereby achieving precise performance optimization, flexible production, and facilitating product diversification and customization.

[0004] However, existing composite wheel hub technology still faces significant bottlenecks. Firstly, regarding materials and connections, to balance cost and performance, a combination of dissimilar materials—cast spokes combined with spun rims—is commonly used. However, the poor compatibility of dissimilar materials during welding easily leads to porosity and cracks at the weld points, affecting the overall reliability and lifespan of the wheel hub. Secondly, the spokes and rims employ different manufacturing processes, and the spun process used to produce the rims has a slower cycle time, resulting in different production cycles for the two. This makes it difficult to seamlessly integrate the overall production process, thus limiting the production efficiency of composite wheel hubs.

[0005] Chinese patent application CN114850440A discloses a vacuum die-cast Al-Mg-Si series aluminum alloy wheel spoke casting. This casting effectively eliminates shrinkage cavities and porosity defects caused by poor filling capacity in traditional low-pressure casting, as well as gas entrapment defects in traditional die casting, thereby improving wheel spoke production efficiency and reducing costs. Furthermore, it significantly reduces the original gas content in the liquid billet while reducing gas in the mold cavity, thus improving casting quality and performance. However, the above method has the following problems: the materials used to prepare the wheel spokes are inconsistent with the materials used for the wheel rim. During the welding process, this material mismatch may lead to stress concentration, deformation, or even cracking. The weld joint is prone to defects such as porosity, inclusions, and cracks. These defects not only affect the welding quality but may also lead to fatigue failure during subsequent use. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this application aims to provide a split-type composite wheel hub with a resonant cavity and its split manufacturing process. It seeks to solve the problems of defects such as shrinkage cavities, porosity, and air holes that easily occur at the joint between the spokes and the rim in existing wheel hub technologies, the poor compatibility and uneven performance caused by welding dissimilar materials between the spokes and the rim in split-type composite wheel hubs, and the problems of traditional spun rims being difficult to form complex structural parts and having a slow production pace. At the same time, it also solves the problem of wheel hubs being difficult to integrate active noise reduction functions.

[0007] To achieve the above objectives, in a first aspect, this application provides a split manufacturing process for a split-type composite wheel hub with a resonant cavity, comprising: S1. Compressed gas is injected into the spoke mold cavity, and the liquid billet is filled into the spoke mold cavity by anti-gravity using the compressed gas. Pressure is maintained to obtain the spoke casting. Semi-solid slurry is injected into the injection chamber and sealed. Under vacuum conditions, the semi-solid slurry is injected from the injection chamber into the rim mold cavity, so that the semi-solid slurry flows unidirectionally from bottom to top until the filling is completed. The vacuum is stopped, and pressure is continuously applied to solidify the semi-solid slurry to obtain the rim casting. The spoke casting and / or the end face of the mating part of the rim casting are provided with an annular groove. S2 fastens the spoke casting and the rim casting together, so that the annular groove forms a closed annular resonant cavity, and then welds the two together to obtain a split-type combined hub.

[0008] Furthermore, when the annular groove is provided only on one end face of the spoke casting and the rim casting, a first positioning boss that mates with the annular groove is provided on the other end face where the annular groove is not provided.

[0009] Furthermore, when both the spoke casting and the rim casting have annular grooves on their mating end faces, a second positioning boss is provided on the inner periphery of one of the annular grooves, and a third positioning boss that can engage with the second positioning boss is provided on the outer periphery of the other annular groove.

[0010] Furthermore, the sidewall thickness of the annular resonant cavity is not less than 1 / 4 to 1 / 3 of the average thickness of the spoke casting.

[0011] Furthermore, in step S2, friction stir welding is used for welding, and the welding parameters are: stirring head rotation speed of 600rpm~800rpm; welding speed of 100mm / min~200mm / min; stirring pin tilt angle of 1.5°~3.5°.

[0012] Furthermore, the liquid billet and the semi-solid slurry are made of the same alloy.

[0013] Furthermore, the relative vacuum degree of the injection chamber and the rim mold cavity is -70kPa to -110kPa.

[0014] Furthermore, the injection parameters for injecting the semi-solid slurry from the injection chamber into the rim mold cavity are as follows: the injection punch presses the semi-solid slurry into the inner sprue at an injection speed of 0.5 m / s to 1 m / s, and then fills the rim mold cavity with the semi-solid slurry at an injection speed of 4 m / s to 6 m / s.

[0015] Furthermore, during the continuous pressurization process to solidify the semi-solid slurry, the pressure of the injection punch is 60MPa~100MPa.

[0016] Secondly, this application provides a split-type composite wheel hub manufactured using the split manufacturing process described above. The split-type composite wheel hub is composed of a spoke casting and a rim casting, and an annular groove is provided on the contact end face of the spoke casting and / or the rim casting. After the spoke casting and the rim casting are fastened and welded together, the annular groove forms a closed annular resonant cavity.

[0017] It is understandable that the beneficial effects of the second aspect mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.

[0018] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art: (1) In this application, the modularly produced spokes and rims are welded together, and prefabricated annular grooves are provided on any one or both end faces where they meet along their circumferential direction. After the spokes and rims are precisely positioned, they are welded together, so that the annular grooves form a closed, continuously distributed annular cavity along the circumference of the hub. The volume and cross-sectional shape of the cavity are precisely defined by the contour of the prefabricated annular grooves. The annular cavity can act as a resonator, generating Helmholtz resonance effect or interference cancellation for tire cavity resonance noise in a specific frequency band, significantly reducing tire noise transmitted into the vehicle compartment and achieving noise reduction. At the same time, since the annular cavity replaces the solid material of the original connection part, the weight of the hub can be effectively reduced while maintaining the overall connection strength, achieving local weight reduction.

[0019] (2) In this application, the spokes are manufactured using a low-pressure casting process, and the rim is manufactured using a semi-solid vacuum die-casting process. Compared with the traditional rim manufactured using spinning, the semi-solid vacuum die-casting process used in this application can precisely form complex structures, including pre-fabricated grooves for the resonant cavity, in one go, achieving integrated manufacturing of function and body. This process also makes the rim structure more uniform, increases material utilization, and significantly improves the production pace compared to spinning, thereby enhancing production integration efficiency and cost control.

[0020] (3) The spokes and rim of the split-type wheel hub of this application are made of the same material, which solves the problem of poor material compatibility when the spokes and rim are welded with dissimilar materials in traditional composite wheel hubs, and makes it easier to achieve low-defect welding. Moreover, the use of the same material reduces the strict control requirements on welding parameters during the production process. Therefore, the friction stir welding of this application has a wider and more stable process window. This allows for the use of relatively low rotation speed and welding speed while ensuring weld quality. In turn, it can effectively reduce the wear of the stirring head and increase the service life of the welding head while ensuring good welding quality and no impact on production efficiency, thereby reducing the overall manufacturing cost.

[0021] (4) The split-type combined wheel hub of this application can also be customized and manufactured in a variety of ways according to the different needs of the rim and the hub. Based on the different stress characteristics of the spokes (which bear complex bending and torsional stress) and the rim (which bears impact and wear), the microstructure, heat treatment state and wall thickness can be designed separately to achieve precise zoning optimization of performance and meet the diverse needs of the wheel hub. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the low-pressure casting process of the wheel spokes provided in Embodiment 1 of this application; Figure 2 This is a schematic diagram of the low-pressure casting filling process of the wheel spokes provided in Embodiment 1 of this application; Figure 3This is a schematic diagram of the low-pressure casting mold opening process of the wheel spokes provided in Embodiment 1 of this application; Figure 4 This is a schematic diagram of the semi-solid vacuum die-casting process of the wheel rim provided in Embodiment 1 of this application; Figure 5 This is a schematic diagram of the semi-solid vacuum die casting process of the wheel rim provided in Embodiment 1 of this application; Figure 6 This is a schematic diagram of the semi-solid vacuum die casting injection process of the wheel rim provided in Embodiment 1 of this application; Figure 7 This is a schematic diagram of the welding positions of the split-type combined wheel hub provided in Embodiment 1 of this application; Figure 8 This is a schematic diagram of the welding positions of the split-type combined wheel hub provided in Embodiment 2 of this application; Figure 9 This is a schematic diagram of the welding position of the split-type combined wheel hub provided in Embodiment 3 of this application.

[0023] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: In the diagram: 1-Upper mold, 2-spoke mold cavity, 3-Lower mold, 4-Liquid riser pipe, 5-Molten aluminum, 6-Crucible, 7-Smelting furnace, 8-Air inlet, 9-Vacuum die casting system, 10-Rim mold cavity, 11-Gating system, 12-spoke casting, 13-Rim casting, 14-Annular resonant cavity, 15-First positioning boss, 16-Second positioning boss, 17-Weld, 18-Third positioning boss. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0025] In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, for example, multiple processing units means two or more processing units, multiple elements means two or more elements, etc.

[0026] The embodiments of this application are described below with reference to the accompanying drawings.

[0027] Example 1 This embodiment provides a modular manufacturing process for a modular composite wheel hub with a resonant cavity, including the following steps: S1 injects compressed gas into the spoke mold cavity, using the compressed gas to fill the spoke mold cavity with liquid blank against gravity, and holds the pressure to obtain spoke casting 12; semi-solid slurry is injected into the injection chamber and sealed, and under vacuum conditions, the semi-solid slurry is injected from the injection chamber into the rim mold cavity, so that the semi-solid slurry flows unidirectionally from bottom to top until the filling is completed, the vacuum is stopped, and the pressure is continuously applied to solidify the semi-solid slurry to obtain rim casting 13; both spoke casting 12 and rim casting 13 have annular grooves on their mating end faces, or only on the mating end faces of spoke casting 12 and rim casting 13, or only on the mating end faces of rim casting 13 and spoke casting 12. S2 fastens the spoke casting 12 and the rim casting 13 together, so that the annular groove forms a closed annular resonant cavity 14. Then, the fastening point of the two is welded together to obtain a split-type combined hub with an annular resonant cavity 14 inside.

[0028] Specifically, such as Figure 1-3 As shown, in step S1, using Figure 1 The low-pressure casting sealing system shown in the figure is used to prepare wheel spoke castings. The preparation method includes the following steps: S101 combines the upper mold 1 and the lower mold 3 to form the spoke mold cavity 2.

[0029] S102 In this embodiment, A356 alloy material is selected to prepare the wheel spokes. The A356 alloy material is placed in the crucible 6 and the melting furnace 6 is started to heat it, so as to melt the aluminum alloy material into aluminum liquid 5 (i.e. liquid billet). The melting temperature is in the range of 700℃~750℃. A356 aluminum alloy has excellent casting performance and high strength after heat treatment, so it is used as the material for casting wheel spokes.

[0030] S103 is used to modify, degas, and remove impurities from liquid billets.

[0031] Specifically, the modification treatment method is to add modifiers (such as sodium salts and sodium) to the liquid billet to change the morphology and distribution of eutectic silicon or other intermetallic compounds, so that they change from undesirable flakes and needles to fine fibers or granules, thereby significantly improving the mechanical properties (especially plasticity and toughness) of the alloy without changing its chemical composition.

[0032] The degassing treatment method is as follows: the degassing treatment of the modified liquid billet is carried out by an ultrasonic vibration device under the protection of inert gas. The ultrasonic vibration device is equipped with a double amplitude transformer. The ultrasonic vibration treatment time is 1min~3min, such as 2min. The ultrasonic power is 3kW~6kW, such as 4kW, 5kW, etc. The temperature of the liquid billet during ultrasonic vibration treatment is 680℃~720℃, such as 690℃, 700℃, or 710℃, etc.

[0033] Impurity removal methods can be filtration or settling. In this embodiment, the settling method is used, that is, the degassed liquid billet is allowed to stand at an isothermal temperature for 5 to 10 minutes, such as 6 minutes, 7 minutes, 8 minutes or 9 minutes, so that the non-metallic inclusions in the liquid metal can precipitate, thereby obtaining the liquid billet for subsequent filling.

[0034] S104L liquid-filled type: such as Figure 2 As shown, compressed gas is introduced into the low-pressure casting sealing system through the air inlet 8. The compressed gas then uses gravity to fill the molten aluminum into the spoke mold cavity 2 via the riser pipe 4, until... Figure 3 The cavity 2 of the wheel spoke mold is completely filled as shown.

[0035] S105 Pressure Holding: The wheel spoke mold cavity 2 filled with molten aluminum is held under pressure for a period of time, so that the molten metal inside cools and forms under pressure. After the mold is opened, the wheel spoke casting 12 can be obtained.

[0036] In this embodiment, the spoke casting 12 and the corresponding rim casting 13 are connected on the end face of the rim casting 13 and an annular groove is provided along the circumference of the rim casting 13. That is, the annular groove is a circular groove around the central axis of the hub. The cross section of the annular groove along the radial direction of the hub can be designed as a regular U-shape or rectangle.

[0037] In step S1, using Figure 4 The vacuum die-casting system 9 shown is used to prepare wheel rim castings. The preparation method includes the following steps: S111 In this embodiment, the spokes and rim are made of the same alloy, that is, the metal raw material A356 aluminum alloy is prepared into a semi-solid slurry in a slurry machine at a temperature of 700℃~740℃.

[0038] After the semi-solid slurry is injected into the injection chamber by S112, the injection chamber is sealed by the injection punch; then the vacuum valve is opened to evacuate the injection chamber and the rim mold cavity 10, so that the relative vacuum degree of the injection chamber and the rim mold cavity 10 is -70kPa to -110kPa.

[0039] S113 as Figure 5 and Figure 6 As shown, the injection punch is pushed to inject semi-solid slurry into the inner runner of the gating system 11 at an injection speed of 0.5m / s to 1m / s (0.6m / s is selected in this embodiment), and then the semi-solid slurry is filled into the rim mold cavity at an injection speed of 4m / s to 6m / s (5m / s is selected in this embodiment).

[0040] During the injection process, the semi-solid slurry flows unidirectionally from bottom to top under pressure. After filling, the vacuum valve is closed, and the semi-solid slurry solidifies within the mold cavity under the pressure of the injection punch. The pressure of the injection punch during the solidification of the liquid billet is in the range of 60MPa to 100MPa. After complete solidification, the rim mold cavity is opened to obtain the rim casting 13, the end face of which is opposite to the spoke casting 12 is flat.

[0041] Friction stir welding (FSW) has low heat input and minimal overall deformation, making it suitable for welding dissimilar aluminum alloys and complex structures. Therefore, in step S2, after the spokes and rim are machined and prepared, as... Figure 7 As shown, the two parts are aligned and fastened together, forming a closed annular cavity with the annular groove. Then, they are welded together using the FSW welding process, and the annular cavity becomes a built-in sealed annular resonant cavity 14, thus obtaining a split-type combined hub with an internal annular resonant cavity 14. Furthermore, the sidewall thickness of the annular resonant cavity 14 should not be less than 1 / 4 to 1 / 3 of the average thickness of the body 12 of the spoke casting.

[0042] The welding parameters in this embodiment are set as follows: the stirring head rotation speed is 600 rpm to 800 rpm. The stirring head rotation speed should not be too high. This rotation speed range facilitates the control of the frictional heat generation rate and prevents the temperature of the welding area (heat-affected zone) from becoming too high, which could damage the resonant cavity structure. The welding speed is 100 mm / min to 200 mm / min. If the speed is too low (<70 mm / min), it will result in excessive heat input, a wider heat-affected zone, and decreased performance. If the speed is too high (>230 mm / min), the heat input will be insufficient, the material will not be sufficiently plasticized, and the flow will be poor, which can easily lead to incomplete penetration, groove defects, or internal pores. The stirring pin tilt angle is 1.5° to 3.5°, which can effectively prevent root incomplete welding and surface groove defects, resulting in a smoother weld surface.

[0043] Specifically, the FSW welding steps in this embodiment are as follows: S201 aligns and connects the contact end faces of the spoke casting 12 and the rim casting 13, so that the end face of the rim casting 13 closes the annular groove on the end face of the spoke casting 12, forming an annular cavity.

[0044] S202 performs circumferential welding along the joint end face gap between the spoke casting 12 and the rim casting 13. In this embodiment, the stirring head rotation speed of the friction stir welding device is set to 600 r / min, the welding speed is 100 mm / min, and the stirring pin inclination angle of the friction stir welding device is 2.5°, resulting in a smooth weld 17.

[0045] After welding, a split-type combined wheel hub with an annular resonant cavity 14 is obtained. The annular cavity located in the rim casting 13 acts as a resonator, which can absorb or cancel noise of specific frequencies, significantly reducing tire noise transmitted into the vehicle compartment and achieving a noise reduction effect. Moreover, since the annular cavity replaces the solid material of the original connection part, the weight of the wheel hub can be effectively reduced while maintaining the overall connection strength, achieving local weight reduction.

[0046] Example 2 The difference between this embodiment and Embodiment 1 is that, as Figure 8 As shown, the spoke casting prepared according to the manufacturing process of this embodiment 1 has an annular groove. The rim casting 13 and the spoke casting 12 have a first positioning boss 15 on their corresponding end faces that can cooperate with the annular groove. Specifically, the first positioning boss 15 is an annular boss arranged circumferentially along the rim casting 13. The annular boss is located at the middle of the end face of the rim casting 13 and can be embedded in the corresponding annular groove, so as to achieve precise alignment between the spoke casting 12 and the rim casting 13. However, the annular boss does not fill the annular groove. A closed annular cavity is formed between the bottom surface of the annular groove and the top surface of the annular boss. After welding, the annular cavity forms an annular resonant cavity 14, which also acts as a resonator. It can absorb or cancel noise of a specific frequency, significantly reduce tire noise transmitted into the vehicle compartment, achieve noise reduction effect, and also achieve wheel hub weight reduction.

[0047] Example 3 The difference between this embodiment and Embodiment 1 is that, as Figure 9 As shown, both the spoke casting 12 and the rim casting 13, prepared according to the two manufacturing processes of Embodiment 1, have annular grooves on their mating end faces. The inner periphery of the annular groove of the spoke casting 12 is also provided with a second positioning boss 16, and the outer periphery of the annular groove of the rim casting 13 is provided with a third positioning boss 18 that can engage with the second positioning boss 16. Before welding, the second positioning boss 16 and the third positioning boss 18 are engaged to precisely align the spoke casting and the rim casting, and to form a closed annular cavity between the two annular grooves after they are joined. After subsequent friction welding, the annular cavity becomes the built-in annular resonant cavity 14 of the split-type combined wheel hub, which also acts as a resonator, absorbing or canceling noise of specific frequencies, significantly reducing tire noise transmitted into the vehicle compartment, achieving a noise reduction effect, and simultaneously achieving wheel hub weight reduction.

[0048] It should be understood that expressions such as “comprising” and “may include” used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as “comprising” and / or “having” are to be interpreted as indicating a particular characteristic, number, operation, constituent element, component, or combination thereof, but not to exclude the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0049] Furthermore, in this application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0050] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. "Fixed connection" refers to a connection where the relative positional relationship remains unchanged after connection. "Rotary connection" refers to a connection where the components can rotate relative to each other after connection. "Sliding connection" refers to a connection where the components can slide relative to each other after connection. The directional terms mentioned in the embodiments of this application, such as "top," "bottom," "inner," "outer," "left," and "right," are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this application, and are not intended to indicate or imply that the device or component 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 the embodiments of this application.

[0051] Furthermore, the mathematical concepts mentioned in the embodiments of this application, such as symmetry, equality, parallelism, and perpendicularity, are limitations specific to the current technological level, rather than absolute and strict mathematical definitions. Slight deviations are permissible; approximations of symmetry, equality, parallelism, and perpendicularity are all acceptable. For example, "A and B are parallel" means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. "A and B are perpendicular" means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0052] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A modular manufacturing process for a modular composite wheel hub with a resonant cavity, characterized in that, include: S1 injects compressed gas into the spoke mold cavity (2), and uses the compressed gas to fill the spoke mold cavity (2) with anti-gravity force to fill the spoke mold cavity (2), and holds the pressure to obtain the spoke casting (12); inject the semi-solid slurry into the injection chamber and seal it. Under vacuum conditions, inject the semi-solid slurry from the injection chamber into the rim mold cavity (10), so that the semi-solid slurry flows unidirectionally from bottom to top until the filling is completed. Stop vacuuming and continue to pressurize to solidify the semi-solid slurry to obtain the rim casting (13); wherein, the spoke casting (12) and / or the rim casting (13) are provided with annular grooves on the mating end faces; S2 fastens the spoke casting (12) and the rim casting (13) together, so that the annular groove forms a closed annular resonant cavity (14), and then welds the two together to obtain a split-type combined hub.

2. The split-type preparation process as described in claim 1, characterized in that, When the annular groove is provided on only one end face of the spoke casting (12) and the rim casting (13), a first positioning boss (15) that cooperates with the annular groove is provided on the other end face where the annular groove is not provided.

3. The split-type preparation process as described in claim 1, characterized in that, When the spoke casting (12) and the rim casting (13) are connected, both end faces are provided with annular grooves. A second positioning boss (16) is provided on the inner periphery of one of the annular grooves, and a third positioning boss (18) is provided on the outer periphery of the other annular groove, which can be fitted with the second positioning boss (16).

4. The split-type preparation process as described in claim 1, characterized in that, The sidewall thickness of the annular resonant cavity is not less than 1 / 4 to 1 / 3 of the average thickness of the body of the spoke casting (12).

5. The split-type preparation process as described in claim 1, characterized in that, In step S2, friction stir welding is used for welding. The welding parameters are: stirring head speed of 600rpm~800rpm; welding speed of 100mm / min~200mm / min; stirring pin tilt angle of 1.5°~3.5°.

6. The split-type preparation process as described in claim 1, characterized in that, The liquid billet and the semi-solid slurry are of the same alloy.

7. The split-type preparation process as described in claim 1, characterized in that, The relative vacuum degree of the injection chamber and the rim mold cavity (10) is -70kPa to -110kPa.

8. The split-type preparation process as described in claim 1, characterized in that, The injection parameters for injecting the semi-solid slurry from the injection chamber into the rim mold cavity (10) are as follows: the injection punch presses the semi-solid slurry to the inner sprue at an injection speed of 0.5 m / s to 1 m / s, and then fills the rim mold cavity (10) with the semi-solid slurry at an injection speed of 4 m / s to 6 m / s.

9. The split-type preparation process as described in claim 1, characterized in that, During the process of solidifying the semi-solid slurry under continuous pressure, the pressure of the injection punch is 60MPa~100MPa.

10. A split-type composite wheel hub manufactured using the split-processing method described in any one of claims 1-9, characterized in that, The split-type combined hub is composed of a spoke casting (12) and a rim casting (13), and an annular groove is provided on the contact end face of the spoke casting (12) and / or the rim casting (13). After the spoke casting (12) and the rim casting (13) are fastened and welded together, the annular groove forms a closed annular resonant cavity (14).

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