A gravity casting mold for aluminum alloy wheel hub

Abstract

The present application relates to a gravity casting mold for an aluminum alloy wheel hub, which belongs to the technical field of aluminum alloy casting. It includes an upper mold, a lower mold and a side mold. The upper mold, the lower mold and the side mold are combined to form a hub cavity. The inner side of the side mold is provided with a plurality of shrinkage-feeding chambers distributed along the circumference of the hub cavity. Each of the shrinkage-feeding chambers is respectively connected to the top rim area of ​​the hub cavity. The side mold is also provided with a lateral cooling assembly, which is distributed on the outside of the shrinkage-feeding chamber. The present application replaces the traditional full-circle side burr with a plurality of independent shrinkage-feeding chambers distributed along the circumference of the hub cavity, and combines the lateral cooling assembly, which is conducive to improving the problems of low metal utilization and long shrinkage-feeding path caused by the traditional full-circle side burr, and improving the shrinkage-feeding efficiency. At the same time, the split-type shrinkage-feeding chamber forms an independent flash after solidification, which is conducive to simplifying the cutting and polishing process and reducing post-processing costs.

Description

Technical Field

[0001] The present application relates to the field of aluminum alloy casting, and in particular to a gravity casting mold for an aluminum alloy wheel hub. Background Art

[0002] The wheel hub is a core component for vehicle load-bearing and steering, and its performance directly impacts driving safety and energy efficiency. Aluminum alloy wheels, thanks to their lightweight and high specific strength, have become a mainstream choice for modern vehicles. Gravity casting, the primary forming process for aluminum alloy wheels, involves molten metal filling the mold cavity with its own weight and then naturally solidifying to form a blank. Key to this process lies in mold design, particularly the side rim, the feeding structure in the wheel rim area.

[0003] The side cap is a liquid storage cavity installed on the side mold of the hub mold. Its core function is to compensate for the molten metal required for rim solidification shrinkage while collecting oxide inclusions and gases. The traditional solution uses a full-circle side cap structure, that is, a continuous annular cavity surrounding the rim. Although this structure can cover the entire shrinkage feeding area, it has inherent defects: the full-circle side cap consumes a large amount of molten aluminum to maintain the shrinkage feeding capacity, and the actual effective utilization rate is low, resulting in waste of raw materials; the continuity of the annular structure makes it difficult to dissipate heat accumulation, significantly extending the rim cooling time and affecting production efficiency; the lengthy shrinkage feeding path increases the flow resistance of the molten metal, and the shrinkage flow rate in the end area is significantly attenuated, which easily leads to shrinkage defects in the spoke transition zone.

[0004] Furthermore, the ring-shaped flash formed after solidification requires cutting and polishing, a tedious and costly post-processing step. Despite attempts to optimize riser size or add cooling channels, the spatial constraints of the ring structure make it difficult to balance feeding efficiency and resource consumption. Achieving the synergy between precise feeding and efficient cooling has become a key challenge in upgrading the gravity casting process for aluminum alloy wheels. Summary of the Invention

[0005] In order to improve the problems of low metal utilization and lengthy feeding path caused by traditional full-ring side burrs, the present application provides a gravity casting mold for an aluminum alloy wheel hub.

[0006] This application provides an aluminum alloy wheel hub gravity casting mold, which adopts the following technical solutions:

[0007] A gravity casting mold for an aluminum alloy wheel hub comprises an upper mold, a lower mold and side molds. The upper mold, lower mold and side molds are combined to form a hub cavity. A plurality of feeding chambers are distributed on the inner side of the side mold along the circumference of the hub cavity. Each of the feeding chambers is connected to the top rim area of ​​the hub cavity. The side mold is also provided with a lateral cooling assembly, which is distributed on the outside of the feeding chamber.

[0008] By adopting the above technical solution, the traditional full-circle side buoy is replaced by multiple independent feeding chambers distributed along the circumference of the hub cavity, and combined with a lateral cooling component, the inherent defects of the traditional annular side buoy are directly improved. On the one hand, the discrete feeding chamber greatly reduces the amount of molten aluminum occupied and reduces the waste of raw materials; the split design shortens the feeding path, ensuring that the flow resistance of molten aluminum in the terminal area such as the spoke transition zone is reduced, avoiding shrinkage defects caused by the attenuation of feeding flow; on the other hand, the lateral cooling component breaks the heat accumulation of the entire circle side buoy through directional heat dissipation, which is conducive to accelerating the sequential solidification of the rim area and shortening the cooling cycle; in addition, the split feeding chamber forms an independent flash after solidification, which simplifies the cutting and polishing process and reduces the post-processing cost, thereby achieving synergy among improving feeding efficiency, reducing resource consumption and optimizing production efficiency.

[0009] Optionally, the cross-sectional area of ​​the feeding chamber is gradually reduced from top to bottom.

[0010] By adopting the above technical solution, the cross-sectional area of ​​the feeding chamber gradually decreases from top to bottom. The tapered structure is used to gradually increase the feeding pressure when the aluminum liquid solidifies and shrinks, compensating for the feeding force loss caused by the reduced volume of the split chamber, ensuring the same feeding strength as the traditional full-ring rim. At the same time, the tapered design guides the aluminum liquid to fill the rim contraction area first, reducing the residual ineffective aluminum liquid and further improving the material utilization rate.

[0011] Optionally, a plurality of mounting grooves are provided on the side mold, and the cooling assembly includes a plurality of rim cooling pipes arranged in the corresponding mounting grooves. The plurality of rim cooling pipes are arranged around the outer side of the shrinkage feeding chamber, and the water inlet and outlet of the rim cooling pipes pass through the outer wall of the side mold.

[0012] By adopting the above technical solution, a rim cooling pipe surrounding the feeding chamber is set in the side mold mounting groove. The heat dissipation rate on the outer side of the split feeding chamber is precisely controlled by cooling water circulation, avoiding the local uneven heat dissipation caused by the continuous structure of the traditional annular cooling water channel, thereby suppressing grain coarsening and improving the mechanical properties of the rim area. At the same time, the discrete layout of the cooling pipe and the feeding chamber adapts to the split thermal field distribution, enhancing the cooling efficiency and feeding capacity.

[0013] Optionally, a pressurizing mechanism is further included above the side mold, and the pressurizing mechanism is used to extrude the aluminum liquid in the feeding chamber.

[0014] By adopting the above technical solution, a pressurizing mechanism is added above the side mold. By applying continuous pressure to the aluminum liquid in the feeding chamber, the aluminum liquid is forced to flow towards the rim area in the later stage of solidification. This compensates for the insufficient dynamic feeding pressure that may exist in the split chamber, significantly improves the feeding effect, reduces internal porosity, and avoids the passive nature of traditional solutions that rely on natural shrinkage feeding.

[0015] Optionally, the pressurizing mechanism includes a sealing cover plate and a thermal expansion sliding assembly provided on the sealing cover plate, the sealing cover plate is used to seal the upper end opening of the shrinkage feeding chamber, the thermal expansion sliding assembly includes an outer sleeve, a microporous plate and a thermal expansion body, the bottom of the outer sleeve is closed and the top is open, the microporous plate is movably arranged in the outer sleeve, and there is a certain friction between the microporous plate and the inner side wall of the outer sleeve, a variable space is provided between the inner bottom wall of the outer sleeve and the microporous plate, the thermal expansion body is filled in the variable space, an extrusion port for the outer sleeve to pass through is provided on the sealing cover plate, a fixing part is provided on the sealing cover plate, and the microporous plate is connected to the fixing part.

[0016] By adopting the above technical solution and utilizing the thermal expansion characteristics of the thermal expansion sliding assembly, the outer sleeve is pushed downward by the thermal expansion of the thermal expansion body during the solidification process of the molten aluminum, and the aluminum liquid pressure in the feeding chamber is automatically adjusted to achieve dynamic feeding that matches the solidification process. Compared with traditional mechanical pressurizing mechanisms, this mechanism simplifies the structure and improves the response stability. At the same time, the friction design between the microporous plate and the outer sleeve buffers sudden pressure changes and prevents rim deformation caused by excessive feeding.

[0017] Optionally, the thermal expansion body is expanded ceramic particles or expanded graphite particles.

[0018] By adopting the above technical solution, expanded ceramic particles or expanded graphite particles are selected as thermal expansion bodies, and their high temperature resistance and stable thermal expansion coefficient are utilized to ensure that the pressurizing mechanism can operate stably for a long time in a high-temperature casting environment, avoiding the performance degradation of traditional metal thermal expansion materials due to oxidation or creep, thereby maintaining the controllability of the shrinkage pressure.

[0019] Optionally, a high-temperature resistant sealing ring is provided on the inner side wall of the extrusion port, and the outer cylinder wall of the outer sleeve is tightly fitted with the inner ring of the high-temperature resistant sealing ring.

[0020] By adopting the above technical solution, a high-temperature resistant sealing ring is set on the inner side of the extrusion port and fits tightly with the outer sleeve to prevent leakage of molten aluminum or gas infiltration, ensuring the sealing during the pressurization process. At the same time, the sealing ring is designed to withstand high-temperature environments, avoiding the frequent maintenance problems caused by thermal fatigue of traditional sealing structures.

[0021] Optionally, a plurality of accommodating grooves are provided on the top of the lower mold, and a chimeric block is provided for sliding sealing in the accommodating grooves, and the chimeric block is connected to a jacking device.

[0022] By adopting the above technical solution, a sliding interlocking block and a lifting device are set on the top of the lower mold. During demolding, the interlocking block is pushed upward by applying uniform force through the lifting rod, eliminating the rigid pulling that relies on mold separation during traditional demolding, avoiding wheel hub deformation or surface damage. At the same time, the sliding sealing design of the interlocking block reduces the infiltration of aluminum liquid into the mold gap, thereby extending the service life of the mold.

[0023] Optionally, the lifting device includes a lifting drive module and a lifting plate arranged at the output end of the lifting drive module, the lifting plate is arranged on the lower side of the lower mold, and a number of lifting rods are arranged on the lifting plate in one-to-one correspondence with the interlocking blocks. The lower end of the lower mold is provided with an avoidance hole for the corresponding lifting rod to pass through, the avoidance hole is connected with the corresponding accommodating groove, the top end of the lifting rod passes through the avoidance hole and is connected to the corresponding interlocking block, the lifting rod is a hollow rod and a bottom cooling part is provided in the lifting rod.

[0024] By adopting the above technical solution, a bottom cooling part is set inside the lifting rod, and the hollow rod structure is used to synchronously cool the bottom of the hub during the lifting process, accelerating the solidification of this area and narrowing the temperature difference with the rim area, thereby reducing the dimensional deviation caused by residual stress. At the same time, the bottom cooling and lateral cooling components form a synergistic heat dissipation network to optimize the overall cooling uniformity.

[0025] Optionally, a pouring system is further included, which includes a gate and a runner provided on the side mold, the gate is funnel-shaped, the upper end of the runner is connected to the lower end of the gate, and the lower end of the runner is connected to the hub cavity, and the cross-sectional area of ​​the runner is set to decrease in a step-by-step manner or nonlinearly with the flow direction of the aluminum liquid.

[0026] By adopting the above technical solution, the cross-sectional area of ​​the pouring system runner is designed to decrease in a stepped or nonlinear manner. The filling speed of the molten aluminum is controlled by the flow resistance gradient, reducing the turbulence and oxidation inclusions caused by the uneven flow rate in the traditional single runner. At the same time, it adapts to the discrete liquid supply requirements of the split-type feeding chamber, ensuring that each feeding chamber is filled synchronously, thereby improving the uniformity of the internal structure of the hub.

[0027] In summary, this application includes at least one of the following beneficial technical effects:

[0028] 1. This application replaces the traditional full-circle side buoy with multiple independent feeding chambers distributed along the circumference of the hub cavity through the provision of multiple independent feeding chambers, and combines them with lateral cooling components to directly improve the inherent defects of the traditional annular side buoy. On the one hand, the discrete feeding chambers greatly reduce the amount of molten aluminum occupied (only covering the key shrinkage area), reducing raw material waste; the split design shortens the feeding path, ensuring that the flow resistance of molten aluminum in the terminal areas such as the spoke transition zone is reduced, avoiding shrinkage defects caused by the attenuation of feeding flow; on the other hand, the lateral cooling component breaks the heat accumulation of the entire circle side buoy through directional heat dissipation, which is conducive to accelerating the sequential solidification of the rim area and shortening the cooling cycle; in addition, the split feeding chamber forms an independent burr after solidification, which simplifies the cutting and polishing process and reduces the post-processing cost, thereby achieving synergy between improving feeding efficiency, reducing resource consumption and optimizing production efficiency.

[0029] 2. By installing a rim cooling pipe surrounding the feeding chamber in the side mold mounting groove, the cooling water circulation accurately controls the heat dissipation rate outside the split feeding chamber, avoiding the localized uneven heat dissipation caused by the continuous structure of traditional annular cooling water channels, thereby suppressing grain coarsening and improving the mechanical properties of the rim area. At the same time, the discrete layout of the cooling pipe and feeding chamber adapts to the split thermal field distribution, enhancing cooling efficiency and feeding capacity.

[0030] 3. By setting up a pressure mechanism, an additional pressure mechanism is added above the side mold. By applying continuous pressure to the aluminum liquid in the feeding chamber, the aluminum liquid is forced to flow to the rim area in the later stage of solidification, compensating for the insufficient dynamic feeding pressure that may exist in the split chamber, significantly improving the feeding effect, reducing internal porosity, and avoiding the passive nature of traditional solutions that rely on natural shrinkage feeding.

[0031] 4. By designing the cross-sectional area of ​​the gating system runner to be stepped or nonlinearly decreasing, the filling speed of the molten aluminum is controlled by the flow resistance gradient, reducing the turbulence and oxidation inclusions caused by uneven flow rate in the traditional single runner. At the same time, it adapts to the discrete liquid supply requirements of the split shrinkage chamber, ensuring that each shrinkage chamber is filled synchronously, thereby improving the uniformity of the internal structure of the wheel hub. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of Example 1 of the present application.

[0033] Figure 2 It is a top view of the side mold in Example 1 of the present application.

[0034] Figure 3 It is a structural diagram showing the specific structure of the feeding chamber in the first embodiment of the present application.

[0035] Figure 4 It is a structural diagram of the pressurizing mechanism in the second embodiment of the present application.

[0036] Figure 5 yes Figure 4 A local enlarged schematic diagram of point A in the middle.

[0037] Figure 6 It is a structural schematic diagram of the jacking device in Example 3 of the present application.

[0038] Explanation of the accompanying drawings: 1. Upper mold; 2. Lower mold; 21. Accommodating groove; 22. Interlocking block; 23. Avoidance hole; 3. Side mold; 31. Shrinkage feeding chamber; 32. Lateral cooling assembly; 321. Rim cooling pipe; 33. Mounting groove; 4. Casting system; 41. Gate; 42. Runner; 5. Hub cavity; 6. Pressurizing mechanism; 61. Sealing cover plate; 611. Extrusion port; 6111. High temperature resistant sealing ring; 612. Fixing part; 6121. Connecting rod; 62. Thermal expansion sliding assembly; 621. Outer sleeve; 622. Microporous plate; 623. Thermal expansion body; 624. Variable space; 7. Lifting device; 71. Lifting drive module; 72. Lifting plate; 73. Lifting rod; 731. Bottom cooling part. DETAILED DESCRIPTION

[0039] The following combination Figures 1-6 , further details of this application are given.

[0040] Example 1:

[0041] The first embodiment of the present application discloses a gravity casting mold for an aluminum alloy wheel hub. Figure 1-Figure 2 A gravity casting mold for an aluminum alloy wheel hub comprises an upper mold 1, a lower mold 2, side molds 3, and a gating system 4. When the upper mold 1, lower mold 2, and side molds 3 are combined, they enclose a hub cavity 5. Multiple feeding chambers 31 are distributed along the circumference of the hub cavity 5 within the side mold 3. Each feeding chamber 31 communicates with the top rim region of the hub cavity 5. The side mold 3 is also provided with lateral cooling assemblies 32, which are located outside the feeding chambers 31. In this first embodiment, four feeding chambers 31 are provided.

[0042] The traditional full-circle side burr of this casting mold is replaced by multiple independent shrinkage chambers 31 distributed circumferentially along the hub cavity 5, forming a "multi-chamber side burr", and combined with a lateral cooling component 32, it directly improves the inherent defects of the traditional annular side burr. On the one hand, the discrete shrinkage feeding chamber 31 greatly reduces the amount of molten aluminum occupied (only covering the key shrinkage area), reducing raw material waste; the split design shortens the shrinkage path, ensuring that the flow resistance of molten aluminum in the terminal area such as the spoke transition area is reduced, avoiding shrinkage defects caused by the attenuation of shrinkage flow; on the other hand, the lateral cooling component 32 breaks the heat accumulation of the entire circle side burr through directional heat dissipation, which is conducive to accelerating the sequential solidification of the rim area and shortening the cooling cycle; in addition, the split shrinkage feeding chamber 31 forms an independent flash after solidification, which simplifies the cutting and polishing process and reduces post-processing costs, thereby achieving synergy among improving shrinkage efficiency, reducing resource consumption and optimizing production efficiency.

[0043] Reference Figure 1 and Figure 3The cross-sectional area of ​​each feeding chamber 31 tapers from top to bottom. In this first embodiment, the feeding chamber 31 is an inverted trapezoid. This tapered structure gradually increases the feeding pressure as the molten aluminum solidifies and shrinks, compensating for the loss of feeding force caused by the reduced volume of the split chamber. This ensures equivalent feeding strength to that of a traditional full-rim rim. Furthermore, the tapered design guides the molten aluminum to preferentially fill the rim's contracted area, reducing ineffective aluminum residue and further improving material utilization.

[0044] Reference Figure 2-Figure 3 A plurality of mounting grooves 33 are provided on the side mold 3, and the cooling assembly includes a plurality of rim cooling pipes 321 provided in the corresponding mounting grooves 33. The plurality of rim cooling pipes 321 are provided around the outside of the feeding chamber 31, and the water inlet and outlet of the rim cooling pipes 321 pass through the outer wall of the side mold 3. In the first embodiment, four rim cooling pipes 321 are provided. In this way, the rim cooling pipes 321 surrounding the feeding chamber 31 are provided in the mounting grooves 33, and the heat dissipation rate outside the split feeding chamber 31 is precisely controlled by circulating cooling water, which is conducive to avoiding the local uneven heat dissipation caused by the continuous structure of the traditional annular cooling water channel, thereby suppressing grain coarsening and improving the mechanical properties of the rim area. At the same time, the discrete layout of the cooling pipes and the feeding chamber 31 adapts to the split thermal field distribution, thereby enhancing the cooling efficiency and feeding capacity.

[0045] Reference Figure 1 and Figure 3 The gating system 4 includes a gate 41 and a runner 42 formed on the side mold 3. The gate 41 is funnel-shaped, with the upper end of the runner 42 communicating with its lower end, and the lower end of the runner 42 communicating with the hub mold cavity 5. The cross-sectional area of ​​the runner 42 decreases in a stepped or nonlinear manner along the direction of aluminum liquid flow. As the aluminum liquid enters the runner 42 from the gate 41, the flow resistance gradient controls its filling speed, reducing turbulence and oxide inclusions caused by uneven flow rates in a traditional single runner 42. This system also accommodates the discrete liquid supply requirements of the split feeding chambers 31, ensuring simultaneous filling of each feeding chamber 31 and further improving the uniformity of the hub's internal structure.

[0046] Example 2:

[0047] The second embodiment of the present application discloses a gravity casting mold for an aluminum alloy wheel hub. Figure 4 The difference between the second embodiment and the first embodiment is that the gravity casting mold further includes a pressurizing mechanism 6 disposed above the side mold 3, which is used to squeeze the molten aluminum in the feeding chamber 31. This second embodiment applies continuous pressure to the molten aluminum in the feeding chamber 31, forcing the molten aluminum to flow toward the rim area during the later stages of solidification. This compensates for the potential lack of dynamic feeding pressure in a split chamber, significantly improving the feeding effect and reducing internal porosity. It also avoids the passive nature of traditional solutions that rely on natural shrinkage feeding.

[0048] Reference Figure 4 and Figure 5 The pressurizing mechanism 6 includes a sealing cover plate 61 and a thermal expansion sliding assembly 62 provided on the sealing cover plate 61. The sealing cover plate 61 is used to seal the upper end opening of the feeding chamber 31. The thermal expansion sliding assembly 62 includes an outer sleeve 621, a microporous plate 622 and a thermal expansion body 623. The bottom of the outer sleeve 621 is closed and the top is open. The microporous plate 622 is movably arranged in the outer sleeve 621, and there is a certain friction between the microporous plate 622 and the inner side wall of the outer sleeve 621. A variable space 624 is provided between the inner bottom wall of the outer sleeve 621 and the microporous plate 622. The thermal expansion body 623 fills the variable space 624. An extrusion port 611 is provided on the sealing cover plate 61 for the outer sleeve 621 to pass through. A fixing part 612 is fixed on the sealing cover plate 61, and the microporous plate 622 is connected to the fixing part 612. In the second embodiment, the fixing member 612 is a fixing frame, and the microporous plate 622 is fixedly connected to the fixing frame by a connecting rod 6121. The connecting rod 6121 is a spring rod, which can buffer the sudden change of thermal expansion pressure, prevent excessive shrinkage compensation, and avoid the microporous plate 622 from being stuck or sealing failure caused by the rigid connection; in addition, the elastic restoring force of the spring rod balances the friction between the microporous plate 622 and the inner wall of the outer sleeve 621, ensuring that the microporous plate 622 can be stably reset after the thermal expansion body 623 cools and shrinks, maintaining the cyclic use reliability of the pressurizing mechanism 6, thereby achieving dynamic balance of shrinkage compensation pressure and structural self-recovery without the need for external control.

[0049] After molten aluminum is injected into the feeding chamber 31 for feeding, the sealing cover plate 61 is pressed onto the side mold 3 and the upper mold 1, thereby sealing the upper end opening of the feeding chamber 31. After the thermal expansion sliding assembly 62 contacts the molten aluminum in the feeding chamber 31, heat transfer occurs. By utilizing the thermal expansion characteristics of the thermal expansion sliding assembly 62, the thermal expansion body 623 expands due to heat during the solidification process of the molten aluminum, pushing the outer sleeve 621 downward, automatically adjusting the molten aluminum pressure in the feeding chamber 31, and realizing dynamic feeding that matches the solidification process. No external power control is required. Compared with the traditional mechanical pressurizing mechanism 6, the structure is simplified and the response stability is improved. At the same time, the friction design between the microporous plate 622 and the outer sleeve 621 buffers sudden pressure changes, preventing rim deformation caused by excessive feeding.

[0050] Reference Figure 5 Thermal expansion bodies 623 are expanded ceramic particles or expanded graphite particles, and their particle size is larger than the micropores in microporous plate 622. In this second embodiment, thermal expansion bodies 623 utilize high-temperature resistant porous ceramic particles. Leveraging their high-temperature resistance and stable thermal expansion coefficient, thermal expansion bodies 623 ensure long-term stable operation of pressurizing mechanism 6 in a high-temperature casting environment, avoiding the performance degradation of conventional metal thermal expansion materials due to oxidation or creep, thereby maintaining controllable feeding pressure.

[0051] Reference Figure 5A high-temperature-resistant sealing ring 6111 is installed on the inner wall of the extrusion port 611. The outer wall of the outer sleeve 621 is tightly fitted with the inner ring of the high-temperature-resistant sealing ring 6111. By installing the high-temperature-resistant sealing ring 6111 inside the extrusion port 611 and tightly fitting it with the outer sleeve 621, aluminum liquid leakage and gas infiltration are prevented, ensuring a tight seal during the pressurization process. Furthermore, the sealing ring is designed to withstand high-temperature environments, avoiding the frequent maintenance issues associated with traditional sealing structures due to thermal fatigue.

[0052] Example 3:

[0053] The third embodiment of the present application discloses a gravity casting mold for an aluminum alloy wheel hub. Figure 1 and Figure 6 The difference between the third embodiment and the first embodiment is that: a plurality of receiving grooves 21 are provided on the top of the lower mold 2, and a chimeric block 22 is provided in the receiving groove 21 for sliding sealing, and the chimeric block 22 is connected to the lifting device 7. In this third embodiment, there are four receiving grooves 21, and the four receiving grooves 21 are arranged in a circular array along the circumference of the hub cavity 5. The balanced lifting force is applied synchronously by the evenly distributed lifting points, which is conducive to avoiding the deformation of the hub or local sticking of the mold caused by one-sided demoulding. At the same time, it adapts to the annular structural characteristics of the hub, so that the lifting rod 73 acts accurately on the high-rigidity area of ​​the spoke root, reducing the risk of indentation in the thin-walled area. In addition, the circumferential array design significantly reduces the risk of jamming caused by local stress concentration and thermal expansion deformation of the mold by evenly dispersing the demoulding reaction force, thereby improving demoulding stability and mold life, and relying on the uniform layout to achieve rapid linkage of the lifting device 7, shortening the demoulding cycle, and thus optimizing production efficiency and product quality.

[0054] Reference Figure 6 The lifting device 7 includes a lifting drive module 71 and a lifting plate 72 fixed to the output end of the lifting drive module 71. The lifting plate 72 is arranged on the lower side of the lower mold 2. A plurality of lifting rods 73 corresponding to the interlocking blocks 22 are fixed on the top of the lifting plate 72. The lower end of the lower mold 2 is provided with an avoidance hole 23 for the corresponding lifting rod 73 to pass through. The avoidance hole 23 is connected to the corresponding accommodating groove 21. The top of the lifting rod 73 passes through the avoidance hole 23 and is connected to the corresponding interlocking block 22. The lifting rod 73 is a hollow rod and a bottom cooling member 731 is provided inside the lifting rod 73. In this third embodiment, the bottom cooling member 731 is a cooling water pipe. The water inlet end of each bottom cooling member 731 is synchronously fed with water, and the water outlet end is synchronously discharged with water, to ensure a synchronous and uniform cooling effect.

[0055] After the hub cavity 5 has cooled and solidified, a slidable interlocking block 22 and a lifting device 7 are installed on top of the lower mold 2. During demolding, the lifting rod 73 evenly applies force to push the interlocking block 22 upward, eliminating the rigid pulling that traditional demolding relies on when separating the molds. In addition, a bottom cooling element 731 is installed inside the lifting rod 73. The hollow rod structure is used to synchronously cool the bottom of the hub during the lifting process, accelerating solidification in this area and narrowing the temperature difference with the rim area, thereby reducing dimensional deviations caused by residual stress. At the same time, the bottom cooling element 731 and the lateral cooling assembly 32 form a synergistic heat dissipation network, thereby optimizing overall cooling uniformity.

[0056] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A gravity casting mold for an aluminum alloy wheel hub, comprising an upper mold (1), a lower mold (2) and a side mold (3), wherein the upper mold (1), the lower mold (2) and the side mold (3) are closed to form a wheel hub cavity (5), characterized in that: The inner side of the side mold (3) is provided with a plurality of feeding chambers (31) distributed along the circumference of the hub cavity (5), and each of the feeding chambers (31) is respectively connected to the top rim area of ​​the hub cavity (5). The side mold (3) is also provided with a lateral cooling assembly (32), and the lateral cooling assembly (32) is distributed on the outside of the feeding chamber (31); The side mold (3) is provided with a plurality of mounting grooves (33), the side cooling assembly (32) includes a plurality of rim cooling pipes (321) correspondingly arranged in the mounting grooves (33), the plurality of rim cooling pipes (321) are arranged around the outside of the feeding chamber (31), and the water inlet and the water outlet of the rim cooling pipe (321) penetrate the outer wall of the side mold (3); The invention also includes a pressurizing mechanism (6) disposed above the side mold (3), the pressurizing mechanism (6) including a sealing cover plate (61) and a thermal expansion sliding assembly (62) disposed on the sealing cover plate (61), the sealing cover plate (61) being used to seal the upper end opening of the feeding chamber (31), the thermal expansion sliding assembly (62) including an outer sleeve (621), a microporous plate (622) and a thermal expansion body (623), the outer sleeve (621) having a closed bottom and an open top, the microporous plate (622) being movably disposed in the outer sleeve (621), and the microporous plate (623) 2) There is a certain friction force between the outer sleeve (621) and the inner wall of the outer sleeve (621), a variable space (624) is provided between the inner bottom wall of the outer sleeve (621) and the microporous plate (622), the thermal expansion body (623) is filled in the variable space (624), the sealing cover plate (61) is provided with an extrusion port (611) for the outer sleeve (621) to pass through, the sealing cover plate (61) is provided with a fixing member (612), a connecting rod (6121) is connected between the microporous plate (622) and the fixing member (612), and the connecting rod (6121) is a spring rod.

2. The aluminum alloy wheel hub gravity casting mold according to claim 1, characterized in that: The cross-sectional area of ​​the feeding chamber (31) is gradually reduced from top to bottom.

3. The aluminum alloy wheel gravity casting mold according to claim 1, characterized in that: The thermal expansion body (623) is expanded ceramic particles or expanded graphite particles.

4. The aluminum alloy wheel gravity casting mold according to claim 3, characterized in that: A high-temperature resistant sealing ring (6111) is provided on the inner side wall of the extrusion port (611), and the outer cylinder wall of the outer sleeve (621) is tightly fitted with the inner ring of the high-temperature resistant sealing ring (6111).

5. The aluminum alloy wheel gravity casting mold according to claim 1, characterized in that: The top of the lower mold (2) is provided with a plurality of accommodating grooves (21), and the accommodating grooves (21) are provided with sliding seals with engaging blocks (22), and the engaging blocks (22) are connected with a jacking device (7).

6. The aluminum alloy wheel hub gravity casting mold according to claim 5, characterized in that: The lifting device (7) includes a lifting drive module (71) and a lifting plate (72) provided at the output end of the lifting drive module (71); the lifting plate (72) is provided on the lower side of the lower mold (2); a plurality of lifting rods (73) are provided on the lifting plate (72) and are arranged in a one-to-one correspondence with the interlocking blocks (22); a avoidance hole (23) for the corresponding lifting rods (73) to pass through is provided at the lower end of the lower mold (2); the avoidance hole (23) is communicated with the corresponding accommodating groove (21); the top end of the lifting rod (73) passes through the avoidance hole (23) and is connected to the corresponding interlocking block (22); the lifting rod (73) is a hollow rod and a bottom cooling member (731) is provided inside the lifting rod (73).

7. The aluminum alloy wheel gravity casting mold according to claim 1, characterized in that: The invention also includes a pouring system (4), wherein the pouring system (4) includes a gate (41) and a runner (42) provided on the side mold (3), wherein the gate (41) is funnel-shaped, the upper end of the runner (42) is connected to the lower end of the gate (41), and the lower end of the runner (42) is connected to the hub cavity (5), and the cross-sectional area of ​​the runner (42) is arranged to decrease in a step-like manner or nonlinearly decrease along with the flow direction of the aluminum liquid.

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