Die for aluminum alloy casting and aluminum alloy casting feeding method

Abstract

The invention discloses a mold for aluminum alloy casting and an aluminum alloy casting feeding method.The mold comprises a left mold body and a right mold body, casting cavities are formed in the left mold body and the right mold body, sand cores are arranged in the casting cavities, the casting cavities are arranged in the vertical direction, the top ends of the casting cavities penetrate to the top of the mold, cap cavities are formed in the two sides of the casting cavities, and the cap cavities communicate with the casting cavities; the casting mold cavity is provided with a main pouring gate penetrating to the top end of the mold, a plurality of transverse pouring gates are arranged beside the main pouring gate, one end of each transverse pouring gate is communicated with the main pouring gate, the other end of each transverse pouring gate is communicated with the cap cavity, and the mold for aluminum alloy casting is used for feeding. The casting mold cavity of the mold for aluminum alloy casting is vertically arranged, the top end of the casting mold cavity is open, aluminum alloy liquid is stably filled from bottom to top, heat can be concentrated to the top, sequential solidification from bottom to top is formed, shrinkage cavities and shrinkage porosity are effectively reduced, an opening in the top provides a direct exhaust channel for gas in the mold and gas generated by a sand core, and the casting mold cavity is more stable. And the risk that the casting generates air holes is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy casting technology, specifically to a mold for aluminum alloy casting and a method for feeding aluminum alloy casting. Background Technology

[0002] Aluminum alloy casting, an indispensable forming process in modern industry, is widely used in the automotive, aerospace, and military industries. Aluminum alloys possess excellent properties such as low density, high specific strength, and good corrosion resistance, making them particularly suitable for manufacturing structural components with high lightweight requirements. As various industries continuously increase the performance requirements of parts, higher demands are being placed on the internal quality, mechanical properties, and reliability of aluminum alloy castings. However, existing aluminum alloy casting methods involve core shooting followed by placement in a mold for pouring, relying on the heat dissipation of the sand core itself and the mold coating to allow the molten aluminum to solidify over time. If the product structure is complex or the wall thickness is uneven, defects such as shrinkage cavities and porosity are prone to occur during solidification, severely affecting the mechanical properties and airtightness of the casting. Summary of the Invention

[0003] The main objective of this invention is to overcome the defects of the prior art and provide a mold for aluminum alloy casting and a method for feeding aluminum alloy casting.

[0004] To achieve the above objectives, the present invention proposes an aluminum alloy casting mold, comprising a left mold and a right mold capable of opening and closing. Each of the left and right molds has a casting cavity on its opposite surface. A sand core is provided within each casting cavity. The casting cavities are arranged vertically along the left and right molds, and the top of each casting cavity extends through to the top of the mold and communicates with the external atmosphere. Several cap-shaped openings are provided on both sides of the casting cavity, and these cap-shaped openings communicate with the casting cavity. A main gating system extends vertically to the top of the mold beside the casting cavity. Several horizontal gating systems are provided along the main gating system, with one end of each horizontal gating system communicating with the main gating system and the other end communicating with the cap-shaped openings.

[0005] Furthermore, the main gating system is an arc-shaped channel that curves toward one side of the mold cavity.

[0006] Furthermore, the cap cavity and the main sprue are provided with through holes that connect to the back of the left mold or the right mold. An ejector pin is movably inserted into the through hole. A top plate is fixedly connected to the ejector pin on the side outside the through hole. Guide rods are horizontally provided around the back of the left mold and the right mold. A support plate is fixedly connected to the end of the guide rod away from the left mold and the right mold. The top plate is provided with guide holes corresponding to the guide rods, so that the top plate can slide left and right on the guide rods. A first hydraulic cylinder is provided on the support plate, and the extended end of the first hydraulic cylinder is connected to the top plate.

[0007] Furthermore, a return spring is sleeved on the guide rod, one end of the return spring abuts against the back of the left mold or the right mold, and the other end of the return spring abuts against the top plate.

[0008] Furthermore, a U-shaped top block is fixedly connected to the extended end of the first hydraulic cylinder, the open end of the U-shaped top block abuts against the back of the top plate, a rotating shaft is mounted inside the U-shaped top block, a cam is fixedly mounted on the rotating shaft, the wheel surface of the cam abuts against the back of the top plate through an amplitude adjustment component, and a drive motor is connected to one end of the rotating shaft.

[0009] Furthermore, the amplitude adjustment assembly includes a lever, a fulcrum, a guide rail, and a second hydraulic cylinder. A connecting rod is provided on the back of the top plate. The resistance arm end of the lever is hinged to the end of the connecting rod. An elongated hole is opened in the middle of the lever along its length. The fulcrum has a U-shaped structure. A fulcrum shaft is mounted on the open end of the fulcrum. The middle part of the fulcrum passes through the elongated hole. Two sets of guide rails are arranged in parallel. The two sets of guide rails are fixed on the back of the top plate. The two sides of the fulcrum are slidably connected to the guide rails. The cylinder body of the second hydraulic cylinder is fixed on the top plate. The extended end of the second hydraulic cylinder is connected to the fulcrum. The wheel surface of the cam abuts against the power arm end of the lever.

[0010] Furthermore, the cap cavity, the through hole, and the ejector pin are all coated with a ceramic heat-insulating coating.

[0011] The present invention also proposes a method for feeding during the casting process using the above-mentioned aluminum alloy casting mold, comprising the following steps: S1. Prepare the chilling coating and apply the prepared chilling coating to the surface of the casting with a more complex structure or thicker wall thickness corresponding to the sand core. S2. After the sand core is placed into the casting cavity of the left mold or the right mold, the left mold and the right mold move towards each other to close the mold. S3. Pour molten aluminum alloy into the opening at the top of the main gating. The molten aluminum alloy enters the cap cavity along the horizontal gating and finally enters the casting cavity. During the pouring process, the liquid level in the casting cavity rises continuously, and the generated gas is discharged from the top of the casting cavity. At the same time, the molten aluminum alloy enters the through hole to fill it. S4. When the aluminum alloy liquid is poured and waiting for solidification, the first hydraulic cylinder is started to push the top plates on the left and right sides of the mold to move towards each other. The ejector pins on both sides force the aluminum alloy liquid that is still in the molten state in the through hole into the cap cavity and the thick part of the casting connected thereto for pressure and feeding. S5. After the casting in the mold cavity has solidified, the left mold and the right mold are opened. The first hydraulic cylinder continues to push the ejector pin on the top plate to extend out of the through hole and abut against the solidification material area of ​​the cap cavity, ejecting the casting from the left mold or the right mold and completing the casting process.

[0012] Further, in step S4, after the end of the ejector pin extends into the cap cavity, the first hydraulic cylinder stops operating, and the drive motor is started to drive the rotating shaft to rotate. The cam on the rotating shaft rotates synchronously. When the cam's convex part abuts against the amplitude adjustment component, it pushes the top plate forward to move closer to the left mold or the right mold. When the cam's convex part rotates out, the top plate retracts under the action of the return spring, causing the ejector pin to reciprocate left and right, acting on the still molten aluminum alloy in the cap cavity to generate vibration, thereby enhancing the feeding ability of the casting. The vibration frequency can be adjusted by the rotation speed of the drive motor.

[0013] Further, in step S4, when the cam's convex part rotates to abut the power arm end of the lever, the power arm of the lever rotates about the fulcrum axis away from the left mold or the right mold, and the resistance arm of the lever pushes the top plate to move closer to the left mold or the right mold, thereby realizing the reciprocating extension and retraction of the ejector pin. When it is necessary to adjust the vibration amplitude, the second hydraulic cylinder drives the fulcrum seat to move up and down along the guide rail, and the fulcrum shaft slides along the elongated hole on the lever, changing the length ratio of the lever's power arm and resistance arm for adjustment.

[0014] The beneficial effects of this invention include: by vertically arranging the mold cavity and opening the top, the molten aluminum alloy fills the mold smoothly from bottom to top, which facilitates the concentration of heat at the top, forming a bottom-up sequential solidification, effectively reducing shrinkage cavities and porosity. The open top provides a direct exhaust channel for gas inside the mold and gas generated by the sand core, greatly reducing the risk of porosity in the casting. The cap cavity, connected to the mold cavity, enhances the feeding capacity. The main gating system, in conjunction with multiple horizontal gating systems, achieves smooth and uniform filling, avoiding turbulence and impact, preventing gas and sand entrapment, and ensuring a clear casting outline and dense internal structure. Attached Figure Description

[0015] Figure 1 This is an overall schematic diagram of the aluminum alloy casting mold in an embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram of the front of the left mold in an embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of the back side of the top plate in an embodiment of the present invention.

[0018] Figure 4 This is a schematic diagram of the cam installation in an embodiment of the present invention.

[0019] Figure 5 This is a schematic diagram of the amplitude adjustment component in an embodiment of the present invention.

[0020] Reference numerals: 1 Left mold; 2 Right mold; 3 Casting cavity; 4 Sand core; 5 Cap cavity; 6 Main runner; 7 Horizontal runner; 8 Through hole; 9 Ejector pin; 10 Ejector plate; 11 Guide rod; 12 Support plate; 13 Guide hole; 14 First hydraulic cylinder; 15 Return spring; 16 U-shaped ejector block; 17 Rotary shaft; 18 Cam; 19 Amplitude adjustment assembly; 191 Lever; 192 Pivot seat; 193 Guide rail; 194 Second hydraulic cylinder; 195 Long hole; 196 Pivot shaft; 20 Drive motor; 21 Connecting rod. Detailed Implementation

[0021] To make the technical problems, technical solutions, and beneficial effects of the embodiments of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0022] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be for both fixing and circuit connection purposes.

[0023] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified. Example 1

[0025] Please see Figures 1 to 5The aluminum alloy casting mold disclosed in this invention includes a left mold 1 and a right mold 2 that can be opened and closed. A casting cavity 3 is provided on the opposite side of the left mold 1 and the right mold 2. After the mold is closed, the casting cavities 3 of the left mold 1 and the right mold 2 form a complete forming chamber. A sand core 4 is provided in the casting cavity 3. The casting cavity 3 is arranged vertically along the left mold 1 and the right mold 2, and the top of the casting cavity 3 extends through to the top of the mold and communicates with the outside atmosphere. Several cap mouths 5 are provided on both sides of the casting cavity 3. The cap mouths 5 are connected to the casting cavity 3. A main sprue 6 is provided vertically next to the casting cavity 3 and extends through to the top of the mold. Several horizontal sprues 7 are provided next to the main sprue 6. One end of the horizontal sprue 7 is connected to the main sprue 6, and the other end of the horizontal sprue 7 is connected to the cap mouths 5. Specifically, the main gating system 6 curves towards the mold cavity 3 to prevent molten aluminum from splashing directly to the bottom, guiding the molten aluminum to fill the mold cavity 3 more naturally and evenly, improving casting quality and efficiency. Three horizontal runners 7 are designed. The inner diameter of the bottom runner 7 is twice that of the main gating system 6, reducing flow resistance and continuously supplying molten aluminum for feeding during the later stages of casting solidification, effectively preventing shrinkage cavities and porosity. The inner diameters of the other two horizontal runners 7 are half that of the main gating system 6, and they are arranged at an upward angle, guiding the molten aluminum to flow smoothly from bottom to top, preventing gas from being drawn into the molten aluminum and forming pores. The cap cavity 5, through-hole 8, and ejector pin 9 are all coated with ceramic insulating paint, forming an effective thermal barrier on the inner walls of the cap cavity 5 and through-hole 8 to delay the solidification time of the molten aluminum in the cap cavity 5 and feeding channels, ensuring the effectiveness of external pressure feeding and improving the internal density of the casting. In this embodiment, by vertically arranging the mold cavity 3 and opening the top, the molten aluminum alloy is smoothly filled from bottom to top, which helps to concentrate heat to the top and form a bottom-up sequential solidification, effectively reducing shrinkage cavities and porosity. The open top provides a direct exhaust channel for gas in the mold and gas generated by the sand core 4, greatly reducing the risk of porosity in the casting. The cap cavity 5 is connected to the mold cavity 3, which enhances the feeding capacity. The main gating 6, together with multiple horizontal gating 7, achieves smooth and uniform filling, avoids turbulence and impact, prevents gas and sand entrapment, and ensures that the casting has a clear outline and dense interior. Example 2

[0026] Please continue reading. Figures 1 to 5In this embodiment, based on embodiment 1, a through hole 8 is provided in the cap cavity 5 and the main sprue 6, which connects to the back of the left mold 1 or the right mold 2. An ejector pin 9 is movably inserted in the through hole 8. A top plate 10 is fixedly connected to the ejector pin 9 on the side outside the through hole 8. Guide rods 11 are horizontally provided around the back of the left mold 1 and the right mold 2 respectively. A support plate 12 is fixedly connected to the end of the guide rod 11 away from the left mold 1 and the right mold 2. A guide hole 13 corresponding to the guide rod 11 is provided on the top plate 10, so that the top plate 10 can slide left and right on the guide rod 11. A first hydraulic cylinder 14 is provided on the support plate 12, and the extended end of the first hydraulic cylinder 14 is connected to the top plate 10. Before pouring, the ejector pins 9 on both sides move backward, so that the molten aluminum alloy can fill the through hole 8 during the pouring process. Before solidification, the first hydraulic cylinders 14 on both sides extend synchronously and drive the top plate 10 to move towards each other, so that the ejector pins 9 push the molten aluminum alloy in the through hole 8 to flow out and fill the cap cavity 5, which then acts on the casting itself to further enhance the feeding pressure.

[0027] In a specific example, a return spring 15 is fitted onto the guide rod 11. One end of the return spring 15 abuts against the back of the left mold 1 or the right mold 2, and the other end abuts against the top plate 10. A U-shaped top block 16 is fixedly connected to the extended end of the first hydraulic cylinder 14. The open end of the U-shaped top block 16 abuts against the back of the top plate 10. A rotating shaft 17 is mounted inside the U-shaped top block 16, and a cam 18 is fixedly mounted on the rotating shaft 17. The wheel surface of the cam 18 abuts against the back of the top plate 10 through the amplitude adjustment component 19. One end of the rotating shaft 17 is connected to a drive motor 20, which uses frequency conversion speed control. When the first hydraulic cylinder 14 pushes the U-shaped top block 16 to the back of the top plate 10, it pushes the top plate 10 (ejector pin 9) from... After the first hydraulic cylinder 14 extends into or parallel to the port of the through hole 8, it stops extending and simultaneously starts the drive motor 20 to drive the cam 18 to rotate. During the rotation of the cam 18, the amplitude adjustment component 19 is pressed to push the top plate 10 to compress the reset spring 15 and move back and forth, generating mechanical vibration, which promotes the feeding and flow of aluminum alloy liquid. The frequency of vibration can be changed by adjusting the rotation speed of the cam 18, and the amplitude of vibration can be adjusted by pressing the amplitude adjustment component 19 to adapt to the structural characteristics, size and shrinkage characteristics of different castings and aluminum alloys.

[0028] In a specific example, the amplitude adjustment component 19 includes a lever 191, a fulcrum 192, a guide rail 193, and a second hydraulic cylinder 194. A connecting rod 21 is provided on the back of the top plate 10. The resistance arm end of the lever 191 is hinged to the end of the connecting rod 21. An elongated hole 195 is opened in the middle of the lever 191 along the length direction. The fulcrum 192 has a U-shaped structure. A fulcrum shaft 196 is mounted on the open end of the fulcrum 192. The middle part of the fulcrum shaft 196 passes through the elongated hole 195. Two sets of guide rails 193 are arranged in parallel. The two sets of guide rails 193 are fixedly mounted on the back of the top plate 10. The two sides of the fulcrum 192 are slidably connected to the guide rails 193. The cylinder body of the second hydraulic cylinder 194 is fixed on the top plate 10. The extended end of the second hydraulic cylinder 194 is connected to the fulcrum 192. The wheel surface of the cam 18 abuts against the power arm end of the lever 191. When the cam 18's convex part presses backward against the power arm of the lever 191, the resistance arm of the lever 191 pushes the connecting rod 21 forward, thereby displacing the top plate 10. The second hydraulic cylinder 194 moves the fulcrum seat 192 on the guide rail 193, changing the position of the fulcrum shaft 196. This alters the ratio between the power arm and resistance arm of the lever 191, causing the displacement of the top plate 10 by the resistance arm of the lever 191 to change when the cam 18's convex part presses backward against the power arm of the lever 191, thus adjusting the amplitude of the ejector pin 9. Different aluminum alloy castings, due to their varying structures, wall thicknesses, and alloy compositions, exhibit different solidification characteristics and require different optimal vibration parameters. By adjusting the frequency and amplitude in real time without stopping the machine, the vibration process can precisely match the needs of a specific casting to achieve optimal feeding and grain refinement effects. Example 3

[0029] Please continue reading. Figures 1 to 5 This invention discloses a method for feeding aluminum alloy casting, which utilizes the aforementioned aluminum alloy casting mold to feed the material during the casting process, and includes the following steps: S1. Prepare the chilling coating and apply it to the surface of the casting with complex structure or thick wall corresponding to the sand core 4. The chilling coating is made by mixing the existing leveling agent KS880 with industrial ethanol. Pour the industrial ethanol into the KS880 coating at a ratio of 1:2 and stir to make the industrial ethanol and coating evenly mixed. The concentration after mixing is 55%-60%. Then, apply the prepared chilling coating evenly to the surface of the sand core 4, mainly to the areas of the casting with complex structure or thick wall, such as product bosses, long cylinders, large radius corners, large flanges, and multi-layer bends. By utilizing the local chilling effect, the aluminum alloy liquid is rapidly cooled in this part during the pouring process, achieving the solidification effect after rapid cooling, improving the overall density of the product, and improving the product's airtightness qualification rate. S2. After placing the sand core 4 into the casting cavity 3 of the left mold 1 or the right mold 2, the left mold 1 and the right mold 2 move towards each other to close the mold; S3. Pour molten aluminum alloy into the opening at the top of the main sprue 6 for pouring. The molten aluminum alloy enters the cap cavity 5 along the horizontal sprue 7 and finally enters the casting cavity 3. During the pouring process, the liquid level in the casting cavity 3 rises continuously, and the generated gas is discharged from the top of the casting cavity 3. At the same time, the molten aluminum alloy enters the through hole 8 for filling; S4. When the molten aluminum alloy pouring is completed and the solidification process is awaited, the first hydraulic cylinder 14 is activated to push the top plates 10 on the sides of the left mold 1 and the right mold 2 respectively. As the casting moves, the ejector pins 9 on both sides force the molten aluminum alloy in the through hole 8 into the cap cavity 5 and the thick part of the casting connected thereto for pressurization and feeding. By providing a pressure much higher than gravity feeding, the molten aluminum alloy can be effectively transported to the area where feeding is difficult, suppressing shrinkage cavities and porosity. S5, after the casting in the casting cavity 3 has solidified, the left mold 1 and right mold 2 open. The first hydraulic cylinder 14 continues to push the ejector pins 9 on the top plate 10 to extend out of the through hole 8 and reach the solidified material area of ​​the cap cavity 5, ejecting the casting from the left mold 1 or right mold 2 and completing the casting.

[0030] In step S4, when the end of the ejector pin 9 extends into the cap cavity 5, the first hydraulic cylinder 14 stops operating, and at the same time, the drive motor 20 is started to drive the rotating shaft 17 to rotate. The cam 18 on the rotating shaft 17 rotates synchronously. When the convex part of the cam 18 touches the amplitude adjustment component 19, it pushes the top plate 10 forward to move closer to the left mold 1 or the right mold 2. When the convex part of the cam 18 rotates out, the top plate 10 retracts under the action of the return spring 15, so that the ejector pin 9 reciprocates left and right to act on the still molten aluminum alloy liquid in the cap cavity 5 to generate vibration, thereby enhancing the feeding ability of the casting. The vibration frequency can be adjusted by the rotation speed of the drive motor 20. When the cam 18 rotates and abuts against the power arm of the lever 191, the power arm of the lever 191 rotates around the fulcrum shaft 196 away from the left mold 1 or the right mold 2. The resistance arm of the lever 191 pushes the top plate 10 to move closer to the left mold 1 or the right mold 2, realizing the reciprocating extension and retraction of the ejector pin 9. When it is necessary to adjust the vibration amplitude, the second hydraulic cylinder 194 drives the fulcrum seat 192 to move up and down along the guide rail 193, and the fulcrum shaft 196 slides along the elongated hole 195 on the lever 191, changing the length ratio of the power arm and the resistance arm of the lever 191 for adjustment. Through the rotation of the cam 18, the ejector pin 9 generates a high-frequency, small-amplitude reciprocating motion, breaking dendrites, reducing the viscosity of the aluminum alloy liquid, reducing the flow resistance of the feeding channel, and significantly promoting the feeding flow. By adjusting the rotation speed of the cam 18 and moving the fulcrum, the vibration frequency and amplitude of the ejector pin 9 can be changed steplessly, so that the vibration process can be accurately matched with castings of different structures / wall thicknesses, find the optimal feeding parameters, and achieve process optimization.

[0031] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A mold for aluminum alloy casting, comprising a left mold and a right mold capable of opening and closing, wherein each of the left mold and the right mold has a casting cavity on its opposite surface, and a sand core is provided in each casting cavity, characterized in that: The casting cavity is arranged vertically along the left and right molds, and the top of the casting cavity extends through to the top of the mold and communicates with the outside atmosphere. Several cap-shaped openings are provided on both sides of the casting cavity, and the cap-shaped openings are connected to the casting cavity. A main sprue is provided vertically next to the casting cavity and extends through to the top of the mold. Several horizontal sprues are provided next to the main sprue. One end of the horizontal sprue is connected to the main sprue, and the other end of the horizontal sprue is connected to the cap-shaped openings.

2. The aluminum alloy casting mold as described in claim 1, characterized in that: The main gating system is an arc-shaped channel that curves toward one side of the mold cavity.

3. The aluminum alloy casting mold as described in claim 2, characterized in that: The cap cavity and the main sprue have through holes that connect to the back of the left mold or the right mold. An ejector pin is movably inserted into the through hole. A top plate is fixedly connected to the ejector pin on the side outside the through hole. Guide rods are horizontally arranged around the back of the left mold and the right mold. A support plate is fixedly connected to the end of the guide rod away from the left mold and the right mold. The top plate has guide holes corresponding to the guide rods, so that the top plate can slide left and right on the guide rods. A first hydraulic cylinder is provided on the support plate, and the extended end of the first hydraulic cylinder is connected to the top plate.

4. The aluminum alloy casting mold as described in claim 3, characterized in that: A reset spring is fitted on the guide rod. One end of the reset spring abuts against the back of the left mold or the right mold, and the other end of the reset spring abuts against the top plate.

5. The aluminum alloy casting mold as described in claim 4, characterized in that: The extended end of the first hydraulic cylinder is fixedly connected to a U-shaped top block. The open end of the U-shaped top block abuts against the back of the top plate. A rotating shaft is mounted inside the U-shaped top block. A cam is fixedly mounted on the rotating shaft. The wheel surface of the cam abuts against the back of the top plate through an amplitude adjustment component. One end of the rotating shaft is connected to a drive motor.

6. The aluminum alloy casting mold as described in claim 5, characterized in that: The amplitude adjustment assembly includes a lever, a fulcrum, a guide rail, and a second hydraulic cylinder. A connecting rod is provided on the back of the top plate. The resistance arm end of the lever is hinged to the end of the connecting rod. An elongated hole is provided in the middle of the lever along its length. The fulcrum has a U-shaped structure. A fulcrum shaft is mounted on the open end of the fulcrum. The middle part of the fulcrum shaft passes through the elongated hole. Two sets of guide rails are arranged in parallel and fixed on the back of the top plate. The two sides of the fulcrum are slidably connected to the guide rails. The cylinder body of the second hydraulic cylinder is fixed on the top plate. The extended end of the second hydraulic cylinder is connected to the fulcrum. The wheel surface of the cam abuts against the power arm end of the lever.

7. The aluminum alloy casting mold as described in claim 6, characterized in that: The cap cavity, the through hole, and the ejector pin are all coated with ceramic heat-insulating coating.

8. A method for feeding aluminum alloy casting, characterized in that: The method of feeding during the casting process using the aluminum alloy casting mold as described in claim 7 includes the following steps: S1. Prepare the chilling coating and apply the prepared chilling coating to the surface of the casting with a more complex structure or thicker wall thickness corresponding to the sand core. S2. After the sand core is placed into the casting cavity of the left mold or the right mold, the left mold and the right mold move towards each other to close the mold. S3. Pour molten aluminum alloy into the opening at the top of the main gating. The molten aluminum alloy enters the cap cavity along the horizontal gating and finally enters the casting cavity. During the pouring process, the liquid level in the casting cavity rises continuously, and the generated gas is discharged from the top of the casting cavity. At the same time, the molten aluminum alloy enters the through hole to fill it. S4. When the aluminum alloy liquid is poured and waiting for solidification, the first hydraulic cylinder is started to push the top plates on the left and right sides of the mold to move towards each other. The ejector pins on both sides force the aluminum alloy liquid that is still in the molten state in the through hole into the cap cavity and the thick part of the casting connected thereto for pressure and feeding. S5. After the casting in the mold cavity has solidified, the left mold and the right mold are opened. The first hydraulic cylinder continues to push the ejector pin on the top plate to extend out of the through hole and abut against the solidification material area of ​​the cap cavity, ejecting the casting from the left mold or the right mold and completing the casting process.

9. The aluminum alloy casting feeding method as described in claim 8, characterized in that: In step S4, after the end of the ejector pin extends into the cap cavity, the first hydraulic cylinder stops operating, and the drive motor is started to drive the rotating shaft to rotate. The cam on the rotating shaft rotates synchronously. When the cam's convex part abuts against the amplitude adjustment component, it pushes the top plate forward to move closer to the left mold or the right mold. When the cam's convex part rotates out, the top plate retracts under the action of the return spring, causing the ejector pin to reciprocate left and right, acting on the still molten aluminum alloy in the cap cavity to generate vibration, thereby enhancing the feeding ability of the casting. The vibration frequency can be adjusted by the rotation speed of the drive motor.

10. The aluminum alloy casting feeding method as described in claim 9, characterized in that: In step S4, when the cam's convex part rotates to abut the power arm end of the lever, the power arm of the lever rotates about the fulcrum axis away from the left mold or the right mold, and the resistance arm of the lever pushes the top plate to move closer to the left mold or the right mold, thereby realizing the reciprocating extension and retraction of the ejector pin. When it is necessary to adjust the vibration amplitude, the second hydraulic cylinder drives the fulcrum seat to move up and down along the guide rail, and the fulcrum shaft slides along the elongated hole on the lever, changing the length ratio of the lever's power arm and resistance arm for adjustment.

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