Aluminum die-casting mold and method based on processing low-porosity cylindrical products

Abstract

The invention discloses an aluminum die-casting mold and method for processing a low-porosity cylindrical product. The cylindrical cavity comprises an annular end and an annular bottom. A bottom overflow system is arranged on the inner side of the annular bottom. The bottom overflow system comprises at least three first slag cavities uniformly distributed on the inner side of the annular bottom in an annular manner. A thin-walled overflow groove for horizontal flow is connected behind each first slag cavity. Each overflow groove is collected at the center position of the annular bottom and connected to the bottom exhaust system. The bottom exhaust system comprises a vertical exhaust channel and a transverse exhaust channel. One end of the vertical exhaust channel is connected to the overflow groove collected at the center position, and the other end is connected to the outside of the mold. One end of the transverse exhaust channel is connected to the middle of the vertical exhaust channel, and the other end is connected to the operating side of the movable mold. The arrangement of the thin-walled overflow groove realizes the natural separation of gas and liquid, so that the gas can be discharged outside the mold through the bottom exhaust system. The transverse exhaust channel is convenient for high-pressure blowing operation, thereby effectively removing the accumulated aluminum slag.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum die-casting, and in particular to an aluminum die-casting mold and method based on processing a low-porosity cylindrical product. Background Art

[0002] like Figure 1-2 As shown, the cylinder product A has a cavity and is a key cooling component for high-power equipment. The characteristics of aluminum alloy materials make it the main material for this type of product. The density of aluminum alloy is much lower than that of steel, but the strength is higher, which makes the aluminum die-cast cylinder product greatly reduce the weight while ensuring the structural strength, which is conducive to energy conservation and emission reduction. Aluminum alloy has excellent thermal conductivity and can quickly transfer heat to ensure the efficiency of the cooling system. In addition, aluminum alloy shows good corrosion resistance in a variety of environments, which can extend the service life of the cylinder product.

[0003] Die casting, as a highly specialized metal casting process, is based on the use of mold cavities to apply high pressure to molten metal to achieve rapid solidification and forming of the metal. This process not only significantly improves production efficiency, but also gives castings high precision, high strength and excellent surface quality. Among many metal materials, aluminum alloy has become the preferred material for the preparation of cylindrical products due to its light weight, high strength, corrosion resistance and good thermal conductivity. Therefore, aluminum die casting technology has naturally become the most common and effective technical means for the production of cylindrical products.

[0004] In the production process of aluminum die-casting cylinder products, the optimization of die-casting process and the design of mold undoubtedly play a vital role. The optimization of die-casting process covers multiple links from metal smelting, alloy ratio, pouring temperature, pressure control to cooling speed. Each link needs to be precisely controlled to ensure that the molten metal can be filled in the mold evenly and quickly to avoid defects such as pores and cold shuts. At the same time, the design of the mold is also a key factor in determining the quality of the casting. The structure of the mold, the selection of the parting surface, the design of the pouring system, and the layout of the cooling system will directly affect the dimensional accuracy, surface quality and internal quality of the casting.

[0005] However, in the actual production process, aluminum die-cast cylinder products face a thorny problem: due to the limitations of the mold structure, an effective exhaust structure cannot be set on the inside of the bottom of the product. As a result, during the die-casting process, the gas in the mold cavity cannot be discharged smoothly, but gathers at the bottom of the product. These gathered gases form shrinkage holes during the solidification of the molten metal, which not only reduces the mechanical properties of the casting, but also increases the risk of leakage. This problem seriously affects the quality and reliability of aluminum die-cast cylinder products and has become a bottleneck restricting the technical development of aluminum die-cast cylinder products.

[0006] In order to solve the problem of gas accumulation at the bottom of the aluminum die-cast cylinder product cavity, such as Figure 3 As shown in the figure, the traditional practice is to open a slag bag B at the bottom of the product for exhaust. The original intention of the slag bag design is to provide a channel for gas escape to reduce the formation of shrinkage holes. However, due to the limitations of the mold structure, the size and position of the slag bag are often strictly limited, resulting in a limited exhaust area. Therefore, although this method can improve the gas exhaust to a certain extent, the improvement effect is not significant. The products actually produced still face the problems of high shrinkage hole ratio and high leakage risk. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide an aluminum die-casting mold and method for processing low-porosity cylindrical products, which are easy to operate, have good exhaust effect, and have low gas shrinkage of the formed cylindrical products.

[0008] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: an aluminum die-casting mold based on processing low-porosity cylindrical products, including a cylindrical cavity, the cylindrical cavity including an annular end and an annular bottom, the annular end connecting multiple gate runners connected to the feed port; a bottom overflow system is provided on the inner side of the annular bottom, and the bottom overflow system includes at least three first slag cavities annularly evenly distributed on the inner side of the annular bottom; each of the first slag cavities is connected to a horizontal thin-walled overflow groove behind, and each overflow groove converges at the center position of the annular bottom and is connected to the bottom exhaust system; the bottom exhaust system includes a vertical exhaust duct and a transverse exhaust duct; one end of the vertical exhaust duct is connected to the overflow duct converging to the center position, and the other end is connected to the outside of the mold; one end of the transverse exhaust duct is connected to the middle of the vertical exhaust duct, and the other end is connected to the operating side of the movable mold.

[0009] The preferred technical solution adopted by the present invention to solve the above technical problems is: the overflow trough includes three straight line segments connected by bends, and from the first slag cavity to the bottom exhaust system are a connecting section, a bending section and a converging section in sequence; the connecting section and the converging section are parallel.

[0010] The preferred technical solution adopted by the present invention to solve the above technical problem is: the overflow groove is a thin structure with a thickness in the range of 0.10-0.15mm.

[0011] The preferred technical solution adopted by the present invention to solve the above technical problem is: the connecting section extends along the outer side of the first slag cavity and the two are parallel, and the angle between the bending section and the connecting section and the converging section is greater than 110°.

[0012] The preferred technical solution adopted by the present invention to solve the above technical problems is: the first slag cavity and the annular bottom are connected by a first overflow channel, and the longitudinal section height of the first overflow channel gradually increases from the annular bottom side to the first slag cavity side, and the length gradually decreases.

[0013] The preferred technical solution adopted by the present invention to solve the above technical problem is: the first overflow flow channel and the connecting section are respectively located on both sides of the first slag cavity in the circumferential direction.

[0014] The preferred technical solution adopted by the present invention to solve the above-mentioned technical problems is: a side overflow system is provided on the outer side of the annular bottom, and the side overflow system includes a plurality of second slag cavities uniformly distributed in an annular shape on the outer side of the annular bottom, the number of the second slag cavities is greater than the number of the first slag cavities, and some of the second slag cavities are connected to the overflow flow channel, and the overflow flow channel includes a first lower transverse section, a first vertical section and a first upper transverse section, the first lower transverse section is connected to the second slag cavity through each first branch, and the first upper transverse section is connected to the first exhaust corrugated plate.

[0015] The preferred technical solution adopted by the present invention to solve the above-mentioned technical problems is: a feed port is provided on the upper side of the cylindrical cavity, the feed port is located on one side of the outer circumference of the cylindrical cavity, the feed port is connected to the gate runner through a feed runner, and the feed runner is bifurcated to form a first arc segment and a second arc segment located on the same ring; the outer end connecting line of the first arc segment and the second arc segment passes through the diameter of the cylindrical cavity; the first half area of ​​the annular end is provided with the gate runner, and the gate runner is inclined from the outside to the inside and from the top to the bottom and gradually expands.

[0016] The preferred technical solution adopted by the present invention to solve the above-mentioned technical problems is: the second half area of ​​the annular end is provided with third slag cavities distributed circumferentially at intervals, the third slag cavities are connected to the overflow flow channel, the overflow flow channel includes a second upper transverse section, a second vertical section and a second lower transverse section, the second upper transverse section is connected to part of the third slag cavity through each second branch, the second lower transverse section is connected to the second exhaust corrugated plate, the first exhaust corrugated plate and the second exhaust corrugated plate are connected and arranged in parallel and parallel with each other.

[0017] Another technical solution adopted by the present invention to solve the above technical problem is: an aluminum die-casting method based on processing a low-porosity cylindrical product, using the aluminum die-casting mold based on processing a low-porosity cylindrical product for processing; the specific steps include:

[0018] Step 1: Close the mold and the aluminum liquid enters the mold.

[0019] Step 2: Die casting, including pre-filling stage, high-speed filling stage and pressurization stage.

[0020] Step 3: After the injection is completed, the aluminum liquid fills the cavity, and the terminal cold material enters the first slag cavity and stagnates in the overflow trough; the gas in the cavity is naturally exhausted to the outside of the mold through the bottom exhaust system.

[0021] Step 4: Open the mold and complete the die casting.

[0022] Step 5: After repeating steps 1 to 4 for at least 10 cycles, high-pressure gas is blown into the bottom exhaust system and the bottom overflow system through the lateral exhaust duct to discharge impurities such as aluminum slag.

[0023] Compared with the prior art, the advantages of the present invention are: the thin-walled overflow groove makes the Laplace force caused by the surface tension of the aluminum liquid seriously affect its flow state, and the effect of the viscosity force is also prominent, which makes it almost impossible for the aluminum liquid to pass through the overflow groove. However, this does not affect the gas in the cavity passing through the overflow groove, thereby achieving the natural separation of gas and liquid, so that the gas can be discharged out of the mold through the bottom exhaust system.

[0024] The vertical exhaust duct is directly connected to the collection point of each overflow trough to ensure that the connection path is unobstructed, so that the gas can be discharged from the outside of the mold more smoothly and unimpeded. The end of the horizontal exhaust duct is specially configured on the operating side of the movable mold to facilitate high-pressure blowing operations here, thereby effectively removing accumulated aluminum slag and ensuring the continuous and efficient operation of the exhaust system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings and preferred embodiments, but those skilled in the art will appreciate that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be used as a limitation on the scope of the present invention. In addition, unless otherwise specified, the drawings are only schematically representing the composition or structure of the described objects and may contain exaggerated displays, and the drawings are not necessarily drawn to scale.

[0026] Figure 1 A schematic diagram of a cylindrical product in the background technology and embodiments Figure 1 ;

[0027] Figure 2 A schematic diagram of a cylindrical product in the background technology and embodiments Figure 2 ;

[0028] Figure 3 It is a schematic diagram of the setting method of a die-casting mold for a cylindrical product in the background technology;

[0029] Figure 4 Schematic diagram of an aluminum die-casting mold for processing a low-porosity cylindrical product in an embodiment Figure 1 ;

[0030] Figure 5 Schematic diagram of an aluminum die-casting mold for processing a low-porosity cylindrical product in an embodiment Figure 1 ;

[0031] Figure 6 Schematic diagram of an aluminum die-casting mold for processing a low-porosity cylindrical product in an embodiment Figure 3 ;

[0032] Figure 7 A partial schematic diagram of an aluminum die-casting mold for processing a low-porosity cylindrical product in an embodiment Figure 1 ;

[0033] Figure 8 A partial schematic diagram of an aluminum die-casting mold for processing a low-porosity cylindrical product in an embodiment Figure 2 .

[0034] Reference numerals:

[0035] Cylindrical product A; annular upper end face a; annular lower end face b; cylindrical cavity c; annular end c1; annular bottom c2; feed port d; gate runner e; feed runner f; bottom overflow system M; first slag cavity 1; overflow trough 2; bottom exhaust system N; vertical exhaust channel 3; transverse exhaust channel 4; connecting section 21; bending section 22; converging section 23; first overflow runner 5; side overflow system G; second slag cavity 7; overflow runner 6; first lower transverse section 61; first vertical section 62; first upper transverse section 63; first branch 64; first exhaust corrugated plate 20; third slag cavity 8; overflow runner 9; second upper transverse section 91; second vertical section 92; second lower transverse section 93; second branch 95; second exhaust corrugated plate 30. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It will be appreciated by those skilled in the art that these descriptions are only illustrative and exemplary and should not be construed as limiting the scope of protection of the present invention.

[0037] It should be noted that like reference numerals denote similar items in the following drawings, and thus, once an item is defined in one drawing, it will not be further defined or explained in the subsequent drawings.

[0038] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or the directions or positional relationships in which the invention product is usually placed when in use, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. "First" and "second" are only for the purpose of making the description easier to understand, without any other directional meaning, and cannot be used as a limitation on the present invention.

[0039] like Figure 1-2 As shown, the cylindrical product A is a thin-walled sleeve product, including an annular upper end face a and an annular lower end face b, wherein the annular lower end face b is used for component sealing, and a corresponding structure is provided thereon. The product has high requirements on the smoothness of the annular lower end face b, and the formation of burr structure needs to be avoided as much as possible.

[0040] like Figure 4-6 As shown, this embodiment provides an aluminum die-casting mold based on processing low-porosity cylindrical products, which is used for die-casting cylindrical products. The mold includes a fixed mold and a movable mold, and the movable mold and the fixed mold enclose a cylindrical cavity. As shown in the figure, in this embodiment, the cavity shape of the cylindrical cavity c and the flow channel is represented by a solid. The cylindrical cavity c includes an annular end c1 and an annular bottom c2, and the annular end c1 is connected to a plurality of gate flow channels e connected to the feed port d.

[0041] It should be noted that a feed port d and a feed channel f are provided on the fixed mold, and the gate channel e is connected to the feed channel f. That is to say, in this embodiment, the aluminum liquid is fed from the annular end c1 of the cylindrical cavity c to fill the entire cylindrical cavity c from top to bottom.

[0042] And, if Figure 4-8 As shown, a bottom overflow system M is provided on the inner side of the annular bottom c2, and the bottom overflow system M includes at least three first slag cavity 1 evenly distributed on the inner side of the annular bottom c2. Each first slag cavity 1 is connected to a thin-walled overflow trough 2 of horizontal flow, and each overflow trough 2 is collected at the center of the annular bottom c2 and connected to the bottom exhaust system N. The bottom exhaust system N includes a vertical exhaust channel 3 and a horizontal exhaust channel 4. One end of the vertical exhaust channel 3 is connected to the overflow channel 2 collected at the center of the circle, and the other end is connected to the outside of the mold. One end of the horizontal exhaust channel 4 is connected to the middle of the vertical exhaust channel 3, and the other end is connected to the operating side of the movable mold.

[0043] In this embodiment, the first slag cavity 1 is evenly distributed in an annular shape, so that the mold is more balanced and it is not easy to produce local gas accumulation. The thin-walled overflow groove 2 is set so that the Laplace force caused by the surface tension of the aluminum liquid will seriously affect its flow state, and the effect of the viscosity is also prominent, which will make it almost impossible for the aluminum liquid to pass through the overflow groove 2. However, this does not affect the gas in the cavity passing through the overflow groove 2, thereby realizing the natural separation of gas and liquid, so that the gas can be discharged from the mold through the bottom exhaust system N. Preferably, the overflow groove 2 is a thin structure with a thickness in the range of 0.10-0.15mm.

[0044] In this embodiment, if Figure 5-6 As shown, the vertical exhaust duct 3 is directly connected to the collection point of each overflow trough 2 to ensure that the connection path is unobstructed. What is particularly critical is that the vertical exhaust duct 3 has no bends, which greatly reduces the possibility of gas accumulation in the pipeline, allowing the gas to be discharged from the outside of the mold more smoothly and unimpeded. In addition, in order to further improve the exhaust efficiency and cope with complex situations in actual production, a transverse exhaust duct 4 is also specially provided. The introduction of the transverse exhaust duct 4 not only provides an additional channel for gas discharge and enhances the overall exhaust capacity, but more importantly, this design fully takes into account the actual problem that aluminum slag may accumulate and block the exhaust duct. Therefore, the end of the transverse exhaust duct 4 is specially configured on the operating side of the movable mold, which is convenient for high-pressure blowing operations here, thereby effectively removing the accumulated aluminum slag and ensuring the continuous and efficient operation of the exhaust system.

[0045] Preferably, if Figure 7 As shown, the overflow trough 2 includes three straight sections connected by bending, which are the connecting section 21, the bending section 22 and the converging section 23 from the first slag ladle cavity 1 to the bottom exhaust system N. This multi-section bending connection construction method not only significantly increases the effective length of the overflow trough 2, but also greatly enhances the effect of slowing down the flow rate of the aluminum liquid, ensuring that the aluminum liquid cannot reach the terminal area of ​​the overflow trough 2.

[0046] In order to maximize the advantages of this design and effectively prevent the occurrence of local gas accumulation, the connecting section 21 and the converging section 23 are designed to be parallel to each other. Such a layout helps to maintain smooth airflow and reduce gas retention caused by structural mutations. Specifically, the connecting section 21 extends closely along the outer side of the first slag cavity 1, and the two maintain a parallel relationship, which not only ensures the compactness of the structure, but also promotes the smooth interaction between the aluminum liquid and the slag cavity.

[0047] In addition, the angle between the bending section 22 and the connecting section 21 and the converging section 23 is greater than 110°. The selection of this angle is intended to further optimize the flow path of the aluminum liquid, further slow down its flow rate, and reduce turbulence and eddy currents caused by sharp turns, which are helpful for more effective precipitation and separation of impurities contained in the aluminum liquid, and also further enhance the ability to prevent the aluminum liquid from reaching the end of the overflow tank 2.

[0048] like Figure 7-8 As shown, the first slag ladle cavity 1 is connected to the annular bottom c2 through the first overflow flow channel 5, and the longitudinal section height of the first overflow flow channel 5 gradually increases from the annular bottom c2 side to the first slag ladle cavity 1 side, and the length gradually decreases. This design not only conforms to the principles of fluid dynamics, but also greatly enhances the flow guidance effect of the flow channel. As the height gradually increases, the flow space of the aluminum liquid in the flow channel is widened, which helps to slow down the flow rate of the aluminum liquid and enable it to transition to the first slag ladle cavity 1 more smoothly. At the same time, the gradual reduction in length further promotes the convergence and concentration of the aluminum liquid.

[0049] like Figure 7 As shown, the first overflow channel 5 and the connecting section 21 are respectively located on both sides of the first slag cavity 1 in the circumferential direction, so that the interference of entry and exit is small, which is conducive to gas-liquid separation and makes it easier for the gas to be discharged through the overflow trough 2.

[0050] As shown in Figures 4-6, a feed port d is provided on the upper side of the cylindrical cavity c. The feed port d is located on one side of the outer circumference of the cylindrical cavity c. The feed port d is connected to the gate runner e through the feed runner f. The feed runner f is bifurcated to form a first arc segment f1 and a second arc segment f2 located on the same ring. The outer end connecting line of the first arc segment f1 and the second arc segment f2 passes through the diameter of the cylindrical cavity c. The first half of the annular end c1 is provided with a gate runner e, which is inclined from the outside to the inside and from the top to the bottom and gradually expands. The bifurcated design of the first arc segment f1 and the second arc segment f2 helps to disperse the impact force of the molten metal flow, reduce the impact on the cavity wall, and extend the life of the mold.

[0051] like Figure 4 As shown, a side overflow system G is provided on the outer side of the annular bottom c2, and the side overflow system G includes a plurality of second slag cavities 7 uniformly distributed in an annular shape on the outer side of the annular bottom c2, the number of the second slag cavities 7 is greater than the number of the first slag cavities 1, and some of the second slag cavities 7 are connected to the overflow flow channel 6, and the overflow flow channel 6 includes a first lower transverse section 61, a first vertical section 62 and a first upper transverse section 63, the first lower transverse section 61 is connected to the second slag cavities 7 through each first branch 64, and the first upper transverse section 63 is connected to the first exhaust corrugated plate 20.

[0052] Preferably, in this embodiment, the number of groups of the first slag cavities 1 and the overflow troughs 2 is 5, and the corresponding number of the second slag cavities 7 is 11, and the two are staggered to a certain extent.

[0053] like Figure 4 , 6 As shown, the second half of the annular end c1 is provided with a third slag cavity 8 distributed at intervals in the circumferential direction, and the third slag cavity 8 is connected to the overflow runner 9. The overflow runner 9 includes a second upper transverse section 91, a second vertical section 92, and a second lower transverse section 93. The second upper transverse section 91 is connected to part of the third slag cavity 8 through each second branch 95, and the second lower transverse section 93 is connected to the second exhaust corrugated plate 30. The first exhaust corrugated plate 20 and the second exhaust corrugated plate 30 are connected and arranged in parallel and parallel. The second upper transverse section 91 is located at the same height as the feed runner f. The second half of the annular end c1 is provided with a slag discharge and exhaust structure, which helps to discharge the gas in the aluminum liquid more quickly during the entire molding cycle, and reduces defects such as pores and looseness in the casting. The design of the exhaust corrugated plate increases the surface area of ​​the exhaust channel and improves the efficiency of gas discharge. It is more conducive to the removal of the subsequent slag bag and runner forming body to connect the overflow runner 6, the first exhaust corrugated plate 20, the overflow runner 9 and the second exhaust corrugated plate 30 on the same side.

[0054] The above aluminum die-casting mold is used to process the cylindrical product. The specific steps include:

[0055] Step 1: Close the mold and the aluminum liquid enters the mold.

[0056] Step 2: Die casting, including pre-filling stage, high-speed filling stage and pressurization stage.

[0057] Step 3: After the injection, the aluminum liquid fills the cavity, and the cold material at the end enters the first slag cavity 1 and stagnates in the overflow tank 2. The gas in the cavity is naturally exhausted to the outside of the mold through the bottom exhaust system N.

[0058] Step 4: Open the mold and complete the die casting.

[0059] Step 5: After repeating steps 1 to 4 for at least 10 cycles, high-pressure gas is blown into the bottom exhaust system N and the bottom overflow system M through the lateral exhaust channel 4 to discharge impurities such as aluminum slag.

[0060] According to practice, after using the aluminum die-casting mold of this embodiment, compared with the mold with a slag bag only on the inner side of the bottom, the defective rate of cylindrical products is reduced from the previous 7% to 8% to 3% to 4%. The die-casting operation using this mold is simple, efficient and reliable.

[0061] The aluminum die-casting mold and method for processing low-porosity cylindrical products provided by the present invention are introduced. The principle and implementation method of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the present invention and its core ideas. It should be pointed out that for ordinary technicians in this technical field, the present invention can also be improved and modified without departing from the principle of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An aluminum die-casting mold for processing low-porosity cylindrical products, characterized in that: It comprises a cylindrical cavity, the cylindrical cavity comprises an annular end and an annular bottom, the annular end is butted against a plurality of gate runners connected to a feed port; aluminum liquid is fed from the annular end of the cylindrical cavity, and fills the entire cylindrical cavity from top to bottom; a bottom overflow system is arranged on the inner side of the annular bottom, the bottom overflow system comprises at least three first slag ladle cavities evenly distributed on the inner side of the annular bottom in an annular shape; each of the first slag ladle cavities is connected to a thin-walled overflow trough behind, each overflow trough is horizontally bent and converges at the center of the annular bottom and is connected to the bottom exhaust system; the bottom exhaust system comprises a vertical exhaust duct and a transverse exhaust duct; one end of the vertical exhaust duct is connected to the overflow duct converged to the center of the circle, and the other end is connected to the outside of the mold; one end of the transverse exhaust duct is connected to the middle of the vertical exhaust duct, and the other end is connected to the operating side of the movable mold; The overflow trough includes three straight sections connected by bending, and from the first slag cavity to the bottom exhaust system, there are a connecting section, a bending section and a converging section in sequence; the connecting section and the converging section are parallel; The connecting section extends parallel to the outer side of the first slag cavity, and the angle between the bending section, the connecting section and the converging section is greater than 110°.

2. An aluminum die-casting mold for processing low-porosity cylindrical products according to claim 1, characterized in that: The thickness of the overflow groove is in the range of 0.10-0.15 mm.

3. An aluminum die-casting mold for processing low-porosity cylindrical products according to claim 1, characterized in that: The first slag cavity is connected to the annular bottom through a first overflow channel. The height of the longitudinal section of the first overflow channel gradually increases from the annular bottom side to the first slag cavity side, and the length gradually decreases.

4. The aluminum die-casting mold for processing low-porosity cylindrical products according to claim 3, characterized in that: The first overflow flow channel and the connecting section are respectively located on two sides of the first slag cavity in the circumferential direction.

5. The aluminum die-casting mold for processing low-porosity cylindrical products according to claim 1, characterized in that: A side overflow system is provided on the outer side of the annular bottom, and the side overflow system includes a plurality of second slag cavities uniformly distributed in an annular shape on the outer side of the annular bottom, the number of the second slag cavities is greater than the number of the first slag cavities, and some of the second slag cavities are connected to the overflow flow channel, and the overflow flow channel includes a first lower transverse section, a first vertical section and a first upper transverse section, the first lower transverse section is connected to the second slag cavity through each first branch, and the first upper transverse section is connected to the first exhaust corrugated plate.

6. The aluminum die-casting mold for processing low-porosity cylindrical products according to claim 5, characterized in that: A feed port is provided on the upper side of the cylindrical cavity, and the feed port is located on one side of the outer circumference of the cylindrical cavity. The feed port is connected to the gate runner through a feed runner, and the feed runner is bifurcated to form a first arc segment and a second arc segment located on the same ring; the outer end connecting line of the first arc segment and the second arc segment passes through the diameter of the cylindrical cavity; the first half area of ​​the annular end is provided with the gate runner, and the gate runner is inclined from outside to inside and from top to bottom and gradually expands.

7. An aluminum die-casting mold for processing low-porosity cylindrical products according to claim 6, characterized in that: The second half of the annular end is provided with third slag cavities distributed circumferentially at intervals, the third slag cavities are connected to the overflow flow channel, the overflow flow channel includes a second upper transverse section, a second vertical section and a second lower transverse section, the second upper transverse section is connected to part of the third slag cavity through each second branch, the second lower transverse section is connected to the second exhaust corrugated plate, the first exhaust corrugated plate and the second exhaust corrugated plate are connected and arranged in parallel and parallel with each other.

8. An aluminum die casting method based on processing low-porosity cylindrical products, characterized in that The aluminum die-casting mold for processing low-porosity cylindrical products according to any one of claims 1 to 7 is used for processing; the specific steps include: Step 1: close the mold and the aluminum liquid enters the mold; Step 2: Die casting, including pre-filling stage, high-speed filling stage and pressurization stage; Step 3: After the injection is completed, the aluminum liquid fills the mold cavity, and the terminal cold material enters the first slag cavity and stagnates in the overflow tank; the gas in the mold cavity is naturally exhausted to the outside of the mold through the bottom exhaust system; Step 4: Open the mold and complete the die casting; Step 5: After repeating steps 1 to 4 for at least 10 cycles, high-pressure gas is blown into the bottom exhaust system and the bottom overflow system through the lateral exhaust duct to discharge impurities such as aluminum slag.

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