Magnesium alloy wheel, wheel mold and vehicle

Abstract

The invention discloses a magnesium alloy wheel, a wheel mold and a vehicle, the magnesium alloy wheel comprises a rim, a mounting disc and spokes connected with the rim and the mounting disc respectively, and the rim, the mounting disc and the spokes are all made of magnesium alloy and are integrally formed based on a semi-solid injection molding process; a plurality of first grooves and heat dissipation holes are evenly formed in the inner side of the spoke in the annular direction at intervals in a concave mode, a plurality of installation holes and second grooves are evenly formed in the installation disc in the annular direction at intervals, a shaft hole is coaxially formed in the middle of the installation disc, and a plurality of compact structure areas are evenly arranged at the position, close to the installation disc, of the spoke in the annular direction at intervals. The position, close to the mounting disc, of the spoke is thickened, a plurality of compact structure areas are arranged in the thickened area, and therefore the structural strength of the whole spoke is improved, particularly, sparse holes do not appear in the compact structure areas and the interiors of the peripheries of the compact structure areas, and meanwhile the NVH performance of the magnesium alloy wheel is remarkably improved; and the weight of the magnesium alloy wheel can be obviously reduced.

Description

Technical Field

[0001] This invention belongs to the field of wheel technology, and particularly relates to a magnesium alloy wheel, wheel mold and vehicle. Background Technology

[0002] Currently, the mainstream materials for wheels are mainly aluminum alloys, traditional magnesium alloys, and steel, but these materials have significant drawbacks: while traditional magnesium alloy wheels have outstanding potential for lightweighting, they suffer from poor corrosion resistance and insufficient mechanical properties. Furthermore, large-sized, thick-walled products are prone to defects such as uneven material flow, shrinkage cavities, and porosity during molding, making it difficult to guarantee dimensional accuracy and density. Aluminum alloy wheels offer limited lightweighting and have high manufacturing costs. Steel wheels are heavy, severely limiting vehicle range and handling performance. Additionally, traditional magnesium alloy molding processes rely heavily on harmful protective gases such as SF6, resulting in high energy consumption and low material utilization, which does not align with green manufacturing principles. Moreover, some magnesium alloy wheels have poor NVH (noise, vibration, and harshness) performance, affecting vehicle ride comfort and failing to meet the requirements of high-end passenger vehicles. Therefore, developing a magnesium alloy wheel that combines high strength, corrosion resistance, lightweighting, green manufacturing, and excellent overall performance has become a pressing technical challenge for the industry. Summary of the Invention

[0003] In order to solve the above-mentioned technical problems, one of the objectives of the present invention is to provide a magnesium alloy wheel with high structural strength, lightweight and good NVH performance.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: A magnesium alloy wheel includes a rim, a mounting plate, and spokes connected to the rim and the mounting plate respectively. The rim, the mounting plate, and the spokes are all made of magnesium alloy and are integrally formed based on a semi-solid injection molding process. The inner side of the spokes is provided with a plurality of first grooves evenly spaced along the circumferential direction, and a heat dissipation hole is provided between two adjacent first grooves. The mounting plate is provided with a plurality of mounting holes evenly spaced along the circumferential direction. The inner side of the mounting plate is provided with a second groove between two adjacent mounting holes. The center of the mounting plate is coaxially provided with a shaft hole. The spokes are provided with a plurality of dense structural regions evenly spaced along the circumferential direction near the mounting plate.

[0005] The beneficial effects of the above-mentioned technical solution of the present invention are as follows: by thickening the wheel spokes near the mounting plate and setting multiple dense structural areas in the thickened area, the structural strength of the entire wheel spoke is improved. In particular, no pores will appear in the dense structural area and the surrounding interior, which significantly improves the NVH performance of the magnesium alloy wheel. Furthermore, by setting heat dissipation holes and a first groove at the wheel spokes and a second groove at the mounting plate, the weight of the magnesium alloy wheel can also be significantly reduced.

[0006] Based on the above technical solution, the present invention can be further improved as follows: Furthermore, the spokes are divided into an outer ring region and an inner ring region in the radial direction. The first groove and heat dissipation hole are disposed in the outer ring region. The thickness of the inner ring region increases, and the thickness of the spokes increases sequentially from the outside to the inside in the radial direction. The multiple dense structure regions are located in the inner ring region.

[0007] The beneficial effects of the above-mentioned further technical solutions are as follows: Since analysis has revealed that the structural strength at the connection between the wheel spoke and the mounting plate is a key factor affecting the strength and NVH characteristics of magnesium alloy wheels, by thickening the wheel spoke near the mounting plate and forming multiple dense structural areas, the structural strength and NVH characteristics of magnesium alloy wheels can be significantly improved.

[0008] Furthermore, the magnesium alloy material is composed of the following components by mass percentage: Al 6.5-8.5wt%, Zn 0.5-1.5wt%, Mn 0.2-0.5wt%, Re 0.3-0.8wt%, impurities ≤0.5wt%, and the balance being Mg.

[0009] The beneficial effects of the above-mentioned further technical solutions are that the magnesium alloy material has good corrosion resistance and structural strength.

[0010] Furthermore, the semi-solid injection molding process includes the following steps: Step 1: Crush the magnesium alloy ingot into granules with a particle size of 3-5mm, and dry them for later use; Step 2: Heat the granules obtained in Step 1 to 580-620℃ to obtain a magnesium alloy semi-solid slurry with a solid phase content of 35-45%. Step 3: Inject the magnesium alloy semi-solid slurry obtained in Step 2 into the wheel mold under a pressure of 80-100 MPa; Step 4: Hold the wheel mold under pressure and cool it in stages until the temperature of the rim is 300±10℃ and the temperature of the mounting plate is 260±10℃, until the magnesium alloy wheel is formed.

[0011] The beneficial effects of the above-mentioned further technical solution are that the resulting magnesium alloy wheel has a dense internal structure, high structural strength, and the surface will not turn yellow, thus affecting its appearance.

[0012] The second objective of this invention is to provide a wheel mold that can be used to manufacture magnesium alloy wheels based on a semi-solid injection molding process.

[0013] To achieve the above objectives, another technical solution of the present invention is as follows: A wheel mold for manufacturing magnesium alloy wheels as described above includes a mold base, a core mold, a top mold, and multiple movable side molds. The mold base is horizontally arranged, and the core mold is circular and horizontally arranged at the upper end of the upper part of the mold base. A core post is coaxially arranged in the middle of the upper end of the core mold, and the core post corresponds to the shaft hole. Multiple first protrusions and second protrusions are circumferentially spaced at the upper end of the core mold. The multiple first protrusions correspond one-to-one with multiple first grooves, and the multiple second protrusions correspond one-to-one with multiple second grooves. Multiple movable side molds... The multiple movable side molds are arranged on the mold base and evenly distributed around the core mold in a circumferential direction. They move synchronously along the radial direction of the core mold to approach the core mold and together form a concave cavity with the core mold. The top mold is used to cover the concave cavity to form a cavity. The lower end of the top mold is provided with multiple third protrusions and multiple fourth protrusions at circumferential intervals. The multiple third protrusions correspond one-to-one with the multiple mounting holes, and the multiple fourth protrusions correspond one-to-one with the multiple heat dissipation holes. The top mold is provided with a grouting nozzle in the middle, which is used to inject magnesium alloy semi-solid grout into the cavity.

[0014] The beneficial effect of the above-mentioned technical solution of the present invention is that: when the multiple movable side molds slide to be close to the core mold, they can form a cavity together with the core mold. After the magnesium alloy wheel is formed, the multiple movable side molds slide away from the core mold, so as to facilitate the removal of the magnesium alloy wheel.

[0015] Furthermore, a plurality of extrusion pins are embedded on the core mold at the position corresponding to the inner side of the wheel spoke. When the magnesium alloy semi-solid slurry is injected into the cavity, the extrusion pins are in a contracted and retracted state and form a material accumulation groove on the core mold. In the initial stage of the magnesium alloy wheel forming in the cavity, the extrusion pins extend to flatten the position corresponding to the mounting plate to form the dense structure area.

[0016] The beneficial effects of the above-mentioned further technical solution are as follows: when the extrusion pin is in the retracted state, the magnesium alloy wheel will have an additional structure in the material groove. During the forming process of the magnesium alloy wheel, when the extrusion pin extends, it can flatten the additional structure into the magnesium alloy wheel, thus forming a dense structural cavity at the corresponding location. Since the material in the dense structural area will diffuse to the periphery during the extrusion process, the density of the entire wheel spoke near the mounting plate can be improved.

[0017] Furthermore, cooling channels are provided at both the edges and the center of the core mold.

[0018] The beneficial effects of the above-mentioned further technical solution are: it allows for better temperature control at the rim and mounting plate during the molding process, thereby preventing the mounting plate of the magnesium alloy wheel from turning yellow, and at the same time improving its molding strength.

[0019] Furthermore, the movable side mold includes a telescopic drive and a side module. The side module is concave on the side closest to the core mold and is slidably mounted on the mold base along the radial direction of the core mold. The telescopic drive is disposed on the mold base and located on the side of the side module away from the core mold. The drive end of the telescopic drive is connected to the side module in a transmission manner. The telescopic drive is used to drive the side module to slide closer to or further away from the core mold.

[0020] The advantages of the above-mentioned further technical solutions are that they have a simple structure and the processes of mold closing and mold opening are relatively convenient.

[0021] Furthermore, four active side molds are provided, and the central angle corresponding to the concave arc side of each side mold is 90°.

[0022] The beneficial effect of the above-mentioned further technical solution is that it makes the mold opening and closing process smoother and reduces the burrs on the magnesium alloy wheel rim after molding.

[0023] The third objective of this invention is to provide a vehicle using magnesium alloy wheels.

[0024] To achieve the above objectives, another technical solution of the present invention is as follows: a vehicle, including magnesium alloy wheels as described above.

[0025] The beneficial effects of the above-mentioned technical solution of the present invention are that the vehicle's wheels are aesthetically pleasing, lightweight, and have good NVH characteristics. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the inner side of the magnesium alloy wheel in an embodiment of the present invention; Figure 2 This is a radial cross-sectional view of the magnesium alloy wheel described in an embodiment of the present invention; Figure 3 This is an elevation view of the wheel mold described in an embodiment of the present invention; Figure 4 This is an elevation view of the wheel mold in an embodiment of the present invention when the top mold is removed; Figure 5 A schematic diagram of the upper end face of the core mold in an embodiment of the present invention; Figure 6 This is a schematic diagram of the lower end face of the top mold in an embodiment of the present invention.

[0027] In the diagram: 1. Wheel rim; 2. Mounting plate; 21. Mounting hole; 22. Second groove; 23. Shaft hole; 3. Wheel spoke; 3a. Outer ring area; 3b. Inner ring area; 31. First groove; 32. Heat dissipation hole; 33. Dense structure area; 100. Wheel mold; 110. Mold base; 120. Core mold; 121. Core pillar; 122. First protrusion; 123. Second protrusion; 124. Extrusion pin; 125. Material collection groove; 126. Cooling channel; 1261. Point cooling point; 130. Top mold; 131. Third protrusion; 132. Fourth protrusion; 133. Injection nozzle; 140. Movable side mold; 141. Telescopic drive component; 142. Side module. Detailed Implementation

[0028] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0030] It is understood that spatial relation terms such as “below,” “under,” “below,” “below,” “above,” “above,” etc., can be used here to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “below,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both upper and lower orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0031] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediary element. In the following embodiments, "connection" should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have the transmission of electrical signals or data between them.

[0032] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0033] Example 1 This embodiment provides a magnesium alloy wheel, including a rim 1, a mounting plate 2, and spokes 3 connected to the rim 1 and the mounting plate 2 respectively. The rim 1, the mounting plate 2, and the spokes 3 are all made of magnesium alloy and are integrally formed based on a semi-solid injection molding process. The inner side of the spokes 3 is provided with a plurality of first grooves 31 evenly spaced along the circumference. There are heat dissipation holes 32 between two adjacent first grooves 31. The mounting plate 2 is provided with a plurality of mounting holes 21 evenly spaced along the circumference. The inner side of the mounting plate 2 is provided with a second groove 22 between two adjacent mounting holes 21. The center of the mounting plate 2 is provided with a shaft hole 23 coaxially. The spokes 3 are provided with a plurality of dense structural regions 33 evenly spaced along the circumference near the mounting plate 2 (from the appearance, the dense structural regions 33 are no different from the surrounding areas, but from a microscopic point of view, the structure here is more dense). By thickening the spokes near the mounting plate 2 and setting multiple dense structural areas in the thickened area, the structural strength of the entire spokes is improved. In particular, no pores appear in the dense structural areas and the surrounding interior, which significantly improves the NVH performance of the magnesium alloy wheel. Heat dissipation holes and a first groove are set at the spokes, while a second groove is set at the mounting plate 2, which can also significantly reduce the weight of the magnesium alloy wheel.

[0034] In this embodiment, multiple dense structural regions correspond one-to-one with multiple second grooves and are aligned with each other in the radial direction of the magnesium alloy wheel. This allows the second grooves to function as weight-reducing grooves without affecting the structural strength of the entire mounting plate.

[0035] Although the spokes in this embodiment are thickened, the overall transition is still a smooth curve, without forming obvious steps or weak structural areas at the steps. Since the thickening of the spokes gradually increases radially from the outside to the inside, the contact point between the spokes and the mounting plate 2 is the thickest point, and the thickening amount at the thickest point of the spokes is 15-25% (compared to aluminum alloy wheels of the same shape and size).

[0036] In this embodiment, the shape and size of the first groove, the heat dissipation hole and the second groove are set as needed. For magnesium alloy wheels, the first groove and the heat dissipation hole should preferably be set as radially distributed strip holes. This can avoid the setting of the first groove and the heat dissipation hole from affecting the structural strength of the wheel spoke. Specifically, the number of heat dissipation holes can be 8-15.

[0037] In this embodiment, the spokes 3 are radially divided into an outer ring region 3a and an inner ring region 3b. The first groove 31 and the heat dissipation hole 32 are located in the outer ring region 3a. The thickness of the inner ring region 3b is increased, and the thickness of the spokes 3 increases radially from the outside to the inside. Multiple dense structural regions 33 are located in the inner ring region 3b. Analysis revealed that the structural strength at the connection between the spokes and the mounting plate 2 is a key factor affecting the strength and NVH characteristics of the magnesium alloy wheel. Therefore, by thickening the spokes near the mounting plate 2 and forming multiple dense structural regions, the structural strength and NVH characteristics of the magnesium alloy wheel can be significantly improved.

[0038] The magnesium alloy material described in this embodiment is composed of the following components by mass percentage: Al (aluminum) 6.5-8.5wt% (which can be any value or any range between 6.5wt%, 7wt%, 7.5wt%, 8wt%, and 8.5wt%), Zn (zinc) 0.5-1.5wt% (which can be any value or any range between 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, and 1.5wt%), Mn (manganese) 0.2-0.5wt% (which can be any value or any range between 0.2wt%, 0.3wt%, 0.4wt%, and 0.5wt%), and Re (rare earth elements). 0.3-0.8wt% (can be any value or range between any two of 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, and 0.8wt%), impurities (unavoidable impurities due to the purity of each raw material) ≤0.5wt%, balance Mg. This magnesium alloy material has good corrosion resistance and structural strength.

[0039] The magnesium alloy material provided in this embodiment significantly improves its corrosion resistance by adding manganese. Iron (Fe), nickel (Ni), and copper (Cu), which are corrosion promoters in magnesium alloys, are significantly reduced by manganese, which forms stable compounds with these elements. For example, iron forms MnAlFe compounds, which exist as a second phase in the magnesium alloy, thus limiting the corrosive effect of impurities. Furthermore, adding manganese improves the grain structure of the magnesium alloy, enhancing its mechanical properties and crack resistance. Adding rare earth elements further improves the corrosion resistance and grain characteristics of the magnesium alloy, particularly reducing porosity and resulting in better overall density and higher strength. The magnesium alloy material provided in this embodiment is an optimized and improved version of the magnesium alloy matrix disclosed in CN120940606A, "A Method for Preparing Magnesium-Based Composite Materials Based on Semi-Solid Injection Molding, and Its Products and Applications."

[0040] For wheels, their strength characteristics and NVH characteristics are negatively correlated. The reason why the NVH characteristics of traditional magnesium alloy wheels are not as good as those of aluminum alloy wheels is precisely because of their poor strength. However, the magnesium alloy wheels provided in this embodiment have significantly improved strength characteristics through optimization of structure, material and process, thereby significantly improving their NVH characteristics.

[0041] The magnesium alloy wheel provided in this embodiment has comparable strength, NVH (noise, vibration, and harshness) characteristics, and corrosion resistance to aluminum alloy wheels, while being lighter in weight.

[0042] The semi-solid injection molding process described in this embodiment includes the following steps: Step 1: Crush the magnesium alloy ingot into particles with a particle size of 3-5mm (which can be any value among 3mm, 4mm and 5mm or any range between two values; selecting this particle size range makes it easier to control the hot melt temperature and solid fraction of the granules during the subsequent hot melt process), and dry them for later use. Step 2: Heat the granules obtained in Step 1 to 580-620℃ (which can be any value or any two of 580℃, 590℃, 600℃, 610℃ or 620℃) to obtain a magnesium alloy semi-solid slurry with a solid fraction of 35-45% (which can be any value or any two of 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44% and 45%, respectively. Selecting this solid fraction makes the magnesium alloy wheel more compact, and at the same time, the grains are fine and there is no dendrite structure, thus further improving the compactness and corrosion resistance of the magnesium alloy wheel). Step 3: The magnesium alloy semi-solid slurry obtained in Step 2 is injected into the wheel mold 100 at a pressure of 80-100MPa (which can be any value or any two values ​​between 80MPa, 85MPa, 90MPa, 95MPa and 100MPa; of course, the higher the slurry pressure, the better the density of the magnesium alloy wheel material. However, considering the production process and cost optimization, this pressure range is more cost-effective. At the same time, the effect of further increasing the pressure on improving the density of the magnesium alloy wheel is not very obvious). Step 4: The wheel mold 100 is held under pressure and cooled in stages until the temperature of the rim 1 reaches 300±10℃ (which can be any value or a range between any two of 290℃, 295℃, 300℃, 305℃, or 310℃), and the temperature of the mounting plate 2 reaches 260±10℃ (which can be any value or a range between any two of 250℃, 255℃, 260℃, 265℃, or 270℃), until the magnesium alloy wheel is formed. This results in a magnesium alloy wheel with a dense internal structure, high structural strength, and a surface that does not yellow, thus maintaining its aesthetic appeal.

[0043] The process parameters of the semi-solid injection molding process described in this embodiment have all been optimized. In particular, the selection of cooling temperatures for the rim 1 and mounting plate 2 in step 4 is also crucial. If the cooling temperature is too low, it will affect the strength characteristics of the aluminum alloy wheel, while if the cooling temperature is too high, it will cause the surface of the magnesium alloy wheel to turn yellow.

[0044] This embodiment also provides a wheel mold for manufacturing the magnesium alloy wheel as described above, including a mold base 110, a core mold 120, a top mold 130, and multiple movable side molds 140. The mold base 110 is horizontally arranged, and the core mold 120 is circular and horizontally arranged at the upper end of the upper end of the mold base 110. A core post 121 is coaxially provided in the middle of the upper end of the core mold 120. The core post 121 corresponds to the shaft hole 23, and multiple first protrusions 122 and second protrusions 123 are arranged circumferentially at intervals on the upper end of the core mold 120. The multiple first protrusions 122 correspond one-to-one with multiple first grooves 31, and the multiple second protrusions 123 correspond one-to-one with multiple second grooves 22. Multiple movable side molds 140 are arranged in the mold base 110. On the mold base 110, and evenly distributed around the core mold 120 in a circumferential direction, multiple movable side molds 140 simultaneously move radially along the core mold 120 to approach the core mold 120, and together with the core mold 120 to form a concave cavity. The top mold 130 is used to cover the concave cavity to form a mold cavity. The lower end of the top mold 130 is provided with multiple third protrusions 131 and multiple fourth protrusions 132 at circumferential intervals. The multiple third protrusions 131 correspond one-to-one with the multiple mounting holes 21, and the multiple fourth protrusions 132 correspond one-to-one with the multiple heat dissipation holes 32. The top mold 130 is provided with a grouting nozzle 133 in the middle, and the grouting nozzle 133 is used to inject magnesium alloy semi-solid grout into the mold cavity. This allows the multiple movable side molds 140 to slide close to the core mold and together with the core mold to form a cavity. After the magnesium alloy wheel is formed, the multiple movable side molds slide away from the core mold, so that the magnesium alloy wheel can be removed.

[0045] In this embodiment, a plurality of extrusion pins 124 are embedded on the core mold 120 at positions corresponding to the inner side of the spoke 3. When the magnesium alloy semi-solid slurry is injected into the cavity, the extrusion pins 124 are in a retracted state, forming a material accumulation groove 125 on the core mold 120. In the initial stage of magnesium alloy wheel forming in the cavity, the extrusion pins 124 extend to flatten the corresponding position of the mounting plate 2 to form the dense structure area 33. In this way, when the extrusion pins are in the retracted state, the magnesium alloy wheel will have an extra part of the structure in the material accumulation groove. During the magnesium alloy wheel forming process, when the extrusion pins extend, they can flatten the extra part of the structure into the magnesium alloy wheel, thus forming a dense structure cavity at the corresponding position. Since the material in the dense structure area will diffuse to the periphery during the extrusion process, the density of the entire spoke near the mounting plate 2 can be improved.

[0046] The extrusion pin 124 can be a hydraulic cylinder embedded in the corresponding position with its extension end facing upward. The upper end of the core mold 120 has a channel for the extension and retraction of the extrusion pin 124. When the extrusion pin 124 retracts into the channel, the material trough 125 is formed at the upper end of the channel. When the extrusion pin 124 extends, it completely fills the channel.

[0047] In this embodiment, cooling channels 126 are evenly distributed at the edges and center of the core mold 120. This allows for better temperature control at the rim 1 and mounting plate 2 during the molding process, thus preventing yellowing of the mounting plate 2 of the magnesium alloy wheel and improving its molding strength. Specifically, the cooling channels 126 at the inner edge of the core mold 120 (corresponding to the rim position) are circumferentially embedded, providing relatively uniform cooling at the edge of the core mold 120. The cooling channels 126 in the center of the core mold 120 (corresponding to the mounting plate position) are evenly embedded with multiple point cooling points 1261 at circumferential intervals. For example, there can be one point cooling point 1261 between two adjacent second protrusions 123 (each point cooling point 1261 can be a spiral coil arranged along the axial direction of the core mold 120, and multiple point cooling points 1261 are connected in sequence to form a cooling channel 126 located in the center of the core mold).

[0048] In this embodiment, the movable side mold 140 includes a telescopic drive component 141 and a side module 142. The side module 142 is concave-arc-shaped on the side near the core mold 120, and is slidably mounted on the mold base 110 along the radial direction of the core mold 120. The telescopic drive component 141 is disposed on the mold base 110 and located on the side of the side module 142 away from the core mold 120. The driving end of the telescopic drive component 141 is connected to the side module 142 in a transmission manner, and the telescopic drive component 141 is used to drive the side module 142 to slide closer to or further away from the core mold 120. Its structure is simple, and the mold closing and opening processes are relatively convenient.

[0049] In this embodiment, the telescopic drive component 141 can be a hydraulic telescopic cylinder or a telescopic electric cylinder. Regarding the measuring module, it can be a square block, except that the side closest to the core mold is concave.

[0050] In this embodiment, four movable side molds 140 are provided, and the central angle corresponding to the concave arc side of each side module 142 is 90°. This makes the mold opening and closing process smoother and reduces burrs at the rim 1 after molding.

[0051] This embodiment overcomes common defects such as uneven material flow, shrinkage cavities, and porosity during the molding process of large-size, thick-walled magnesium alloy wheels, improving product density and dimensional accuracy, ensuring the stability of mass production. Furthermore, the resulting magnesium alloy wheels are significantly lighter than aluminum alloy wheels of the same shape and size. Lightweighting has become a core path to reducing energy consumption and improving driving range in automobiles. As a key unsprung component, the wheel follows the weight reduction effect of "one kilogram under the sprung means ten kilograms on the sprung," making its lightweight upgrade extremely urgent.

[0052] This embodiment optimizes the materials, processes, and molds of magnesium alloy wheels to address the core pain points of traditional magnesium alloy wheels, namely poor corrosion resistance and insufficient mechanical properties (corresponding to poor NVH characteristics). It achieves a synergistic improvement in strength and corrosion resistance, meeting the stringent requirements of high-end vehicles for structural reliability. At the same time, it eliminates the use of harmful protective gases such as SF6 during the molding process, reducing production energy consumption and manufacturing costs, improving material utilization, achieving green and efficient production, and significantly improving the poor NVH performance of traditional magnesium alloy wheels, thereby enhancing vibration and noise control during vehicle operation and improving driving comfort.

[0053] The optimized magnesium alloy wheels meet the design requirements of bending fatigue life ≥ 500,000 cycles, radial fatigue life 1.3 million cycles, lateral stiffness 60 KN / mm, and weight ≤ 12.3 kg.

[0054] The magnesium alloy material provided in this embodiment achieves simultaneous improvement in mechanical properties and corrosion resistance through synergistic optimization of composition. Its yield strength is ≥180MPa, tensile strength is ≥260MPa, elongation is ≥8%, and neutral salt spray corrosion rate is ≤0.3mm / year, providing reliable material protection for wheels.

[0055] This embodiment also provides a vehicle including the magnesium alloy wheels as described in Embodiment 1. The wheels of this vehicle are aesthetically pleasing, lightweight, and possess good NVH characteristics.

[0056] Specific examples: (I) Material Preparation Weigh the raw materials precisely by weight percentage: Al 7.5wt%, Zn 1.0wt%, Mn 0.3wt%, RE 0.5wt%, impurities ≤0.5%, balance Mg; The raw materials are smelted in a medium-frequency induction furnace, and the smelting temperature is controlled at 720-740℃. Argon gas is introduced for refining and degassing to ensure the purity of the melt. The refined melt is cast into magnesium alloy ingots, machined into granules with a particle size of 3-5mm, and then dried in a drying oven at 120℃ for 2 hours to remove moisture and impurities for later use.

[0057] (II) Molding process 1. Equipment debugging: Use a 3000t magnesium alloy special injection molding equipment to check the high-speed injection device and temperature control module to ensure that the injection pressure accuracy is ±1MPa and the temperature control accuracy is ±5℃. 2. Preheating of wheel mold: Heat the wheel mold to 280-300℃, maintain the temperature control accuracy of each area, and ensure the molding effect of the slurry; 3. Preparation of semi-solid magnesium alloy slurry: The dried magnesium alloy particles are fed into the hopper, the feed screw speed is set to 30-50 r / min, and the feed pipe is heated by zone heating control to heat the raw material to 580-620℃ to form a semi-solid slurry with a solid phase content of 42%. 4. Injection Molding: The injection pressure of the 3000t magnesium alloy injection molding equipment is set to 90MPa, the filling time to 0.25s, the holding pressure to 60MPa, and the holding time to 15s. Vacuum equipment is used throughout the injection process. The local extrusion mechanism is activated in the rounded corner area of ​​the wheel spokes, applying an extrusion pressure of 120MPa and holding for 5s to ensure that the microstructure of the thick-walled area is dense. 5. Post-processing: The molded parts are cooled using a graded cooling process. After cooling, deburring, surface cleaning, and other processes are performed to obtain the finished wheel. 6. Inspection: X-ray flaw detection is performed on the finished wheels to ensure that there are no defects such as porosity and shrinkage cavities; mechanical property tests are conducted, and the measured tensile strength is 275MPa, yield strength is 185MPa, and elongation is 9%; a neutral salt spray test is carried out, and there is no obvious corrosion after 1000 hours. All performance indicators meet the design requirements.

[0058] The magnesium alloy wheels provided in this embodiment can be applied to passenger vehicles, such as sedans, SUVs, or commercial vehicles.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A magnesium alloy wheel, characterized in that, The wheel includes a rim (1), a mounting plate (2), and spokes (3) connected to the rim (1) and the mounting plate (2) respectively. The rim (1), the mounting plate (2), and the spokes (3) are all made of magnesium alloy and are integrally formed by semi-solid injection molding. The inner side of the spokes (3) is provided with a plurality of first grooves (31) evenly spaced along the circumference. There are heat dissipation holes (32) between two adjacent first grooves (31). The mounting plate (2) is provided with a plurality of mounting holes (21) evenly spaced along the circumference. The inner side of the mounting plate (2) is provided with a second groove (22) between two adjacent mounting holes (21). The mounting plate (2) is provided with a shaft hole (23) coaxially in the middle. The spokes (3) are provided with a plurality of dense structural areas (33) evenly spaced along the circumference near the mounting plate (2).

2. The magnesium alloy wheel according to claim 1, characterized in that, The spokes (3) are divided into an outer ring area (3a) and an inner ring area (3b) in the radial direction. The first groove (31) and the heat dissipation hole (32) are disposed in the outer ring area (3a). The thickness of the inner ring area (3b) increases, and the thickness of the spokes (3) increases from the outside to the inside in the radial direction. A plurality of the dense structure areas (33) are located in the inner ring area (3b).

3. The magnesium alloy wheel according to claim 1, characterized in that, The magnesium alloy material is composed of the following components by mass percentage: Al 6.5-8.5wt%, Zn 0.5-1.5wt%, Mn 0.2-0.5wt%, Re 0.3-0.8wt%, impurities ≤0.5wt%, and the balance is Mg.

4. The magnesium alloy wheel according to claim 1, characterized in that, The semi-solid injection molding process includes the following steps: Step 1: Crush the magnesium alloy ingot into granules with a particle size of 3-5mm, and dry them for later use; Step 2: Heat the granules obtained in Step 1 to 580-620℃ to obtain a magnesium alloy semi-solid slurry with a solid phase content of 35-45%. Step 3: Inject the magnesium alloy semi-solid slurry obtained in Step 2 into the wheel mold (100) under a pressure of 80-100 MPa; Step 4: Pressurize the wheel mold (100) and cool it in stages until the temperature of the rim (1) is 300±10℃ and the temperature of the mounting plate (2) is 260±10℃, until the magnesium alloy wheel is formed.

5. A wheel mold for manufacturing a magnesium alloy wheel as described in any one of claims 1-4, characterized in that, The assembly includes a mold base (110), a core mold (120), a top mold (130), and multiple movable side molds (140). The mold base (110) is horizontally positioned. The core mold (120) is circular and horizontally positioned at the upper end of the mold base (110). A core post (121) is coaxially positioned at the center of the upper end of the core mold (120). The core post (121) corresponds to the shaft hole (23). Multiple first protrusions (122) and second protrusions (123) are circumferentially spaced at the upper end of the core mold (120). The multiple first protrusions (122) correspond one-to-one with multiple first grooves (31), and the multiple second protrusions (123) correspond one-to-one with multiple second grooves (22). Multiple movable side molds (140) are positioned on the mold base (110) and circumferentially... The core mold (120) is evenly distributed in the circumferential direction. Multiple movable side molds (140) move synchronously along the radial direction of the core mold (120) to approach the core mold (120) and together with the core mold (120) to form a concave cavity. The top mold (130) is used to cover the concave cavity to form a cavity. The lower end of the top mold (130) is provided with multiple third protrusions (131) and multiple fourth protrusions (132) in the circumferential direction. The multiple third protrusions (131) correspond one-to-one with the multiple mounting holes (21), and the multiple fourth protrusions (132) correspond one-to-one with the multiple heat dissipation holes (32). The top mold (130) is provided with a grouting nozzle (133) in the middle. The grouting nozzle (133) is used to inject magnesium alloy semi-solid grout into the cavity.

6. The wheel mold according to claim 5, characterized in that, Multiple extrusion pins (124) are embedded on the core mold (120) at positions corresponding to the inner side of the spokes (3). When magnesium alloy semi-solid slurry is injected into the cavity, the extrusion pins (124) are in a retracted state and form a material accumulation groove (125) on the core mold (120). In the early stage of the magnesium alloy wheel forming in the cavity, the extrusion pins (124) extend to flatten the corresponding position of the mounting plate (2) to form the dense structure area (33).

7. The wheel mold according to claim 5, characterized in that, Cooling channels (126) are evenly distributed at the edges and center of the core mold (120).

8. The wheel mold according to claim 5, characterized in that, The movable side mold (140) includes a telescopic drive (141) and a side module (142). The side module (142) is concave arc-shaped on the side near the core mold (120), and the side module (142) is slidably mounted on the mold base (110) along the radial direction of the core mold (120). The telescopic drive (141) is disposed on the mold base (110) and located on the side of the side module (142) away from the core mold (120). The driving end of the telescopic drive (141) is connected to the side module (142) in a transmission manner. The telescopic drive (141) is used to drive the side module (142) to slide close to or away from the core mold (120).

9. The wheel mold according to claim 8, characterized in that, The active side mold (140) is provided in four parts, and the central angle corresponding to the concave arc side of each side module (142) is 90°.

10. A vehicle, characterized in that, Including the magnesium alloy wheels as described in any one of claims 1-4.

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