A split structure metal mold low pressure pouring distributor and a method of using the same

Abstract

This application relates to a split-type metal mold low-pressure casting distributor and its usage method. The distributor consists of an upper mold and a lower mold, which are fixed together by bolts. The upper mold has bolt interfaces for connecting to the mold and the lower mold, facilitating quick assembly and disassembly. The lower mold has a riser pipe interface in its center for receiving molten aluminum. The interior of the flow channel interface of the upper mold cover and the inner surface of the cavity of the lower mold base are coated with an insulation layer. Compared with integrated distributors heated by gas, this distributor saves on the cost of natural gas or liquefied petroleum gas (LPG). During product manufacturing, there is no need to consider the safety of using natural gas or LPG. Most importantly, when designing the casting temperature process parameter, process designers only need to control and optimize the temperature of the casting furnace through equipment, eliminating the variable of unstable molten aluminum temperature during casting that occurs with integrated distributors, thus significantly improving process stability.

Description

Technical Field

[0001] This application relates to the field of low-pressure casting technology for aluminum alloy castings, specifically to a split-structure low-pressure casting distributor for metal molds and its usage method. Background Technology

[0002] Low-pressure casting of aluminum alloy castings using metal molds is a key forming technology in modern industry, with wide applications, particularly in the automotive, aerospace, and high-end equipment manufacturing sectors. This process involves smoothly pouring molten metal into a metal mold (metal mold) from bottom to top under relatively low pressure, completing the filling and solidification process under controlled conditions. It is particularly suitable for manufacturing complex, thin-walled aluminum alloy castings requiring high density, lightweight, and structural integrity. The distributor in the low-pressure casting mold is a crucial component connecting the riser pipe and the mold. Its main function is to evenly and smoothly distribute the molten metal into each cavity, ensuring complete filling and a dense structure in the casting. The distributor is typically made of heat-resistant steel and features a rationally designed flow channel system that controls the flow direction and speed of the molten metal, reducing turbulence and air entrapment. During the low-pressure pouring process, the distributor also acts as a buffer and pressure stabilizer, allowing the molten metal to rise smoothly under pressure, avoiding impact on the mold cavity, thus obtaining castings with excellent surface quality and a dense internal structure. A well-designed distributor is essential for improving casting yield and quality.

[0003] In low-pressure casting processes using metal molds, the distributor must be continuously heated to ensure the molten aluminum maintains ideal fluidity in the flow channels, thus smoothly and completely filling the mold cavity and providing effective pressure feeding during the solidification stage of the casting. In batch continuous production of castings, gas nozzles are typically placed around the distributor, and the distributor is heated by burning natural gas or liquefied petroleum gas (LPG). This method uses the high-temperature flame generated by gas combustion to quickly heat the distributor to its operating temperature, making it particularly suitable for large castings or continuous production. It reduces preheating time, and natural gas or LPG is inexpensive, significantly reducing energy costs for long-term continuous production. The gas heating system also has low investment costs and is easy to maintain. However, gas heating has lower temperature control accuracy, larger temperature fluctuations, and poor process stability, significantly impacting the quality stability of the castings. Furthermore, gas is a flammable and explosive medium, requiring strict safety measures such as leak detection and explosion-proof devices.

[0004] In view of this, this application provides a novel device for a low-pressure casting distributor for aluminum alloy castings, which aims to eliminate the heating process in the casting process of the low-pressure casting distributor, stabilize the casting process temperature, and avoid potential safety hazards during the heating process. Summary of the Invention

[0005] The technical problem this application aims to solve is that traditional integrated distributors suffer from inconvenient maintenance, large heat loss, and difficulty in cleaning the flow channels.

[0006] To address the aforementioned technical problems, according to one aspect of this application, a split-structure metal low-pressure casting distributor is provided, comprising: an upper cover body, including a quasi-annular strip with uniform thickness and a plurality of flow channel interfaces uniformly arranged along the inner ring of the strip, a recessed cover plate between the strip and the plurality of flow channel interfaces, a heat insulation layer inside the flow channel interfaces, and a plurality of positioning holes and bolt connection ports penetrating the strip; and a lower base cavity, including an opening corresponding to the upper cover body and a distributor inner cavity arranged downward along the bottom side of the opening, the inner wall of the distributor inner cavity having flow channels corresponding to the flow channel interfaces, the distributor inner cavity being coated with a heat insulation layer, and a riser pipe interface being provided at its bottom center; wherein, the opening of the lower base cavity has small holes corresponding to the positioning holes and bolt connection ports of the upper cover body, and the upper cover body and the lower base cavity are detachably connected by bolts.

[0007] According to the embodiments of this application, both the upper cover and the lower base cavity are made of 42CrMo heat-resistant steel, and the thickness of the heat-resistant steel body is 15mm.

[0008] According to embodiments of this application, the upper cover and the lower base cavity are manufactured by a combination of casting and machining.

[0009] According to an embodiment of this application, the insulation layer is a fiber paste coating, which is made by mixing aluminum silicate fiber, high-temperature binder and water in a mass ratio of 100:15-20:30-40, and the total coating thickness is 15mm.

[0010] According to embodiments of this application, the high-temperature binder is any one of aluminum phosphate, silica sol, and water glass.

[0011] According to an embodiment of this application, the opening is a ring-shaped strip that is adapted to the shape and size of the bottom side of the upper cover.

[0012] According to an embodiment of this application, the cover plate is a cover plate formed by two tightly fitted steel bodies.

[0013] According to another aspect of this application, a method of using a split-structure metal low-pressure casting distributor as described above is provided, comprising the following steps:

[0014] S1: Materials for preparing the insulation layer;

[0015] S2: Coating the insulation layer: The flow channel interface of the upper cover and the inner cavity of the distributor of the lower base are coated in multiple layers. Each layer is 3-5mm thick, and each layer is dried at a low temperature of 100℃ after each coating. Finally, it is baked and cured at 300~400℃.

[0016] S3: Combine the upper cover and the lower base cavity, fasten them together with bolts, and assemble them into a distributor;

[0017] S4: Install the mold and distributor: Use a crane to lift the bottom of the mold, place the distributor on the mold, and then tighten it with bolts;

[0018] S5: Distributor heating: Preheat the distributor and the metal low-pressure casting mold to 150-250℃.

[0019] S6: Casting filling: Start the low-pressure casting equipment for metal molds, and distribute the castings evenly to each cavity of the external mold through the flow channel formed by the upper and lower molds of the distributor;

[0020] S7: Remove the casting: After the aluminum liquid fills and solidifies, remove the casting from the external mold.

[0021] According to an embodiment of this application, step S1 specifically includes the following steps: first, dry mix aluminum silicate fiber and high-temperature adhesive evenly, then gradually add water and stir until there is no dry powder or lumps; after standing for 10-15 minutes to mature, it can be used.

[0022] According to an embodiment of this application, step S2 specifically includes the following steps: applying the insulation layer material in three coats, each coat being 5 mm thick, drying it at a low temperature in an oven at 100°C after each coat, and finally baking and curing it at 300~400°C.

[0023] The split-type metal low-pressure casting distributor of the present invention has significant advantages over the conventional integral distributor:

[0024] 1. Energy saving and consumption reduction: The split structure makes it easy to accurately apply the fiber paste insulation layer into the inner cavity of the distributor, effectively reducing heat loss. Compared with the integral structure, it can reduce gas consumption and has a significant energy saving effect in long-term continuous production.

[0025] 2. Improved production safety: The split design makes maintenance and operation more convenient. The flow channel can be cleaned or the insulation layer replaced without the need for overall hoisting, avoiding safety hazards in high-temperature operations. The split connection is fastened with bolts, which is reliable and eliminates the risk of aluminum liquid leakage, significantly improving operational safety.

[0026] 3. Improved process stability: The insulation layer can stably maintain the temperature of the molten aluminum, reduce the impact of temperature fluctuations on the filling quality, and ensure that the casting has a dense structure and no cold shut defects; the split structure facilitates regular cleaning of oxide scale and carbon deposits, keeps the flow channels unobstructed, improves production continuity and casting yield, and significantly enhances process stability.

[0027] 4. Reduced maintenance costs of metal molds: The split structure facilitates localized repair and replacement without the need for complete scrapping, extending the lifespan of the distributor, reducing spare parts costs and maintenance expenses, and improving equipment utilization.

[0028] 5. Improved production efficiency: The split design makes mold installation and disassembly more convenient, shortens production preparation time, and improves equipment utilization efficiency. It is especially suitable for the production of aluminum alloy castings using metal mold low-pressure processes. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this application, and are not intended to limit this application.

[0030] Figure 1 This is a schematic diagram of the structure of an integrated distributor in the prior art;

[0031] Figure 2 This is a schematic diagram of a split-type metal low-pressure casting distributor in an example of the present invention;

[0032] Figure 3 This is a schematic diagram of the upper structure of a split-type metal low-pressure casting distributor in an example of the present invention;

[0033] Figure 4 for Figure 3 Top view;

[0034] Figure 5 for Figure 3 A schematic diagram of the cross-sectional structure along the AA direction;

[0035] Figure 6 This is a schematic diagram of the lower structure of a split-type metal low-pressure casting distributor in an example of the present invention;

[0036] Figure 7 for Figure 6 Top view;

[0037] Figure 8 for Figure 7 A schematic diagram of the cross-sectional structure along the BB direction.

[0038] The annotations in the attached figures are explained as follows:

[0039] 1. Insulation layer, 2. Gas pipeline, 3. Mold connection port, 4. Gas pipe support, 10. Upper mold cover, 11. Strip body, 12. Cover plate, 13. Bolt interface, 14. Positioning hole, 15. Flow channel interface, 20. Lower mold base cavity, 21. Opening, 22. Flow channel, 23. Liquid riser interface, 24. Distributor inner cavity. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the described embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains. The terms “first,” “second,” and similar terms used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a,” and similar terms, do not indicate a limitation of quantity, but rather indicate the presence of at least one.

[0042] like Figure 1 As shown, the commonly used type of low-pressure metal casting mold is the integral type. The main body is designed with a mold connection port 3 for connecting to an external mold. A gas nozzle, gas pipe 2, and gas pipe support 4 need to be installed around it to heat the distributor by burning natural gas or liquefied petroleum gas (LPG). This method uses the high-temperature flame generated by gas combustion to quickly heat the distributor to its operating temperature. It is particularly suitable for large castings or continuous production, reducing preheating time. Furthermore, natural gas or LPG is inexpensive, significantly reducing energy costs during long-term continuous production. The gas heating system also has low investment costs and is easy to maintain.

[0043] However, gas heating has low temperature control accuracy, large temperature fluctuations, and poor process stability, which has a significant impact on the quality stability of castings. In addition, gas is a flammable and explosive medium, requiring strict safety protection measures such as leak detection and explosion-proof devices.

[0044] like Figures 2 to 8As shown in the example, this application presents a split-structure metal low-pressure casting distributor, consisting of an upper mold (cover) and a lower mold (base cavity), which are fixed together by bolts. The upper mold has a bolt interface 13 for connecting to the mold and the lower mold, facilitating quick assembly and disassembly. The lower mold has a riser pipe interface 23 at its center for receiving molten aluminum. The interior of the flow channel interface 15 of the upper mold cover 10 and the inner surface of the lower mold base cavity 20 are both coated with an insulation layer 1. Compared to integrated distributors heated by gas, this distributor saves on natural gas or liquefied petroleum gas (LPG) usage costs. During product manufacturing, there is no need to consider the safety of using natural gas or LPG. Most importantly, when designing the casting temperature process parameter, process designers only need to control and optimize the temperature of the casting furnace through equipment, eliminating the variable of unstable molten aluminum temperature during casting that occurs with integrated distributors, thus significantly improving process stability.

[0045] In this embodiment, as Figure 3 , Figure 4 As shown, a split-type metal low-pressure casting distributor includes an upper cover 10. The upper cover 10 includes a ring-shaped strip 11 with uniform thickness and a plurality of flow channel interfaces 15 uniformly arranged along the inner circle of the strip 11. An inwardly recessed cover plate 12 is provided between the strip 11 and the plurality of flow channel interfaces 15. A heat insulation layer 1 is provided inside the flow channel interfaces 15. A plurality of positioning holes 14 and bolt connection ports are provided through the strip 11.

[0046] Specifically, the bolt interface 13 machined on the upper cover 10 includes a bolt interface 13 for connecting to the external mold and a connecting bolt hole for matching the lower mold.

[0047] Specifically, the upper cover 10 is preferably made of heat-resistant steel body made of 42CrMo heat-resistant steel, and the thickness of the heat-resistant steel body is 15mm.

[0048] Specifically, such as Figure 5 As shown, the cover plate 12 can be a cover plate formed by two tightly fitted steel bodies.

[0049] In this embodiment, as Figure 6 , Figure 7 As shown, the lower base cavity 20 includes an opening 21 corresponding to the upper cover 10 and a distributor cavity 24 disposed downward along the bottom side of the opening 21. The inner wall of the distributor cavity 24 is provided with a flow channel 22 corresponding to the flow channel interface 15. The distributor cavity 24 is coated with a heat insulation layer 1, and a liquid riser interface 23 is provided at the bottom center.

[0050] Specifically, an insulation layer 1 is coated on the surface of the inner cavity 24 of the distributor. The total thickness of the insulation layer 1 is preferably 15mm. Therefore, the thickness of the insulation layer 1 should be taken into account when designing the volume of the inner cavity 24 of the distributor.

[0051] Specifically, the lower base cavity 20 is preferably made of heat-resistant steel body made of 42CrMo heat-resistant steel, and the thickness of the heat-resistant steel body is 15mm.

[0052] Specifically, the insulation layer material inside the distributor cavity 24 is a fiber paste. A layer of high-temperature resistant fiber paste material is coated onto the surface of the distributor cavity 24. The insulation layer 1 is a fiber paste coating made by mixing aluminum silicate fiber, high-temperature binder, and water in a mass ratio of 100:15~20:30~40, with a total coating thickness of 15mm. The insulation layer 1 (fiber paste) of the cavity, through its low thermal conductivity, effectively blocks heat exchange between the molten aluminum and the external heat-resistant steel body, reducing heat loss and thus stabilizing the temperature of the molten aluminum, avoiding casting defects such as poor filling and cold shuts caused by temperature fluctuations.

[0053] Specifically, the high-temperature binder is any one of aluminum phosphate, silica sol, and water glass.

[0054] Specifically, such as Figure 6 As shown, the opening 21 is a ring-shaped strip that matches the shape and size of the bottom side of the upper cover 10. The opening 21 is machined with a sealing surface and bolt holes to match the upper cover, ensuring that the flow channel 22 is unobstructed and well-sealed after the upper and lower covers are connected.

[0055] Specifically, the upper cover 10 and the lower base cavity 20 are manufactured by a combination of casting and machining.

[0056] In this embodiment, the opening 21 of the lower mold base cavity 20 is provided with small holes corresponding to the positioning holes 14 and bolt connection ports of the upper mold cover 10. The upper mold cover 10 and the lower mold base cavity 20 are detachably connected by bolts, preferably high-strength heat-resistant bolts. This design facilitates the installation, disassembly, and maintenance of the mold. In particular, when the distributor channel 22 needs to be cleaned or replaced, only the upper cover needs to be removed, eliminating the need for overall hoisting, which greatly improves operational convenience and production efficiency. At the same time, the split structure is beneficial for processing and manufacturing, reducing the processing difficulty of the large and complex channel 22.

[0057] Another aspect of this application discloses a method of using a split-structure metal low-pressure casting distributor as described above, comprising the following steps:

[0058] S1: Materials for preparing insulation layer 1;

[0059] Specifically, step S1 includes the following steps: first, dry mix the aluminum silicate fiber with the high-temperature binder until uniform, then gradually add water and stir until there is no dry powder or lumps; after standing for 10-15 minutes to mature, it can be used.

[0060] S2: Coating insulation layer 1: The flow channel interface 15 of the upper cover 10 and the distributor inner cavity 24 of the lower base cavity 20 are coated in multiple layers. Each coating is 3-5mm thick, and each coating is dried at a low temperature of 100℃ after each coating. Finally, it is baked and cured at 300~400℃.

[0061] Specifically, step S2 includes the following steps: applying the material of insulation layer 1 in 3 coats, each coat being 5mm thick, drying it at a low temperature in an oven at 100℃ after each coat, and finally baking it at 300~400℃ for curing.

[0062] Specifically, the insulation layer is applied in 5 coats, each coat being 3mm thick. After each coat, it is dried at a low temperature in an oven at 100℃, and finally baked and cured at 300~400℃, with a total thickness of 15mm.

[0063] S3: Combine the upper cover 10 and the lower base cavity 20, fasten them together with bolts, and assemble them into a distributor;

[0064] S4: Install the mold and distributor: Use a crane to lift the bottom of the mold, place the distributor on the mold, and then tighten it with bolts;

[0065] S5: Distributor heating: Preheat the distributor and the metal low-pressure casting mold to 150-250℃;

[0066] S6: Casting filling: Start the low-pressure casting equipment for metal molds, and distribute the castings evenly to each cavity of the external mold through the flow channel 22 formed by the upper and lower molds of the distributor;

[0067] S7: Remove the casting: After the aluminum liquid fills and solidifies, remove the casting from the external mold.

[0068] The working process of a split-structure metal low-pressure casting distributor in this embodiment is as follows: The lower mold is fixed at the designated position of the low-pressure casting equipment, and the riser pipe is sealed and connected to the riser pipe interface 23 at the center of the lower mold; the sealing surfaces of the upper and lower molds are aligned, and the upper and lower molds are fastened together with high-strength heat-resistant bolts to complete the assembly of the distributor body; then, the distributor is sealed and connected to the external aluminum alloy casting mold through the bolt interface 13 of the upper mold; during low-pressure casting, the aluminum liquid enters the inner cavity 24 of the distributor through the riser pipe interface 23 of the lower mold under the action of low-pressure gas; the heat insulation layer 1 prevents the heat of the aluminum liquid from being lost to the heat-resistant steel body, so that the temperature of the aluminum liquid is stabilized within the range required by the casting process (680-700℃); under pressure, the aluminum liquid is evenly distributed to each cavity of the external mold through the flow channel formed by the cooperation of the upper and lower molds to complete the filling and solidification process.

[0069] Understandably, after 72 hours of continuous production, the aluminum slag in the flow channel needs to be cleaned and the insulation layer needs to be checked: disassemble the connecting bolts between the upper mold and the mold and the lower mold, and directly remove the upper mold without hoisting the entire distributor; after cleaning the aluminum slag in the flow channel, check the insulation layer, and re-coat the damaged areas according to the above coating process. After the re-coating is completed, reassemble the upper mold to resume production.

[0070] In summary, the technical solution of this application has the following beneficial effects:

[0071] 1. Energy saving and consumption reduction: The split structure makes it easy to accurately apply fiber paste into the inner cavity of the distributor, effectively reducing heat loss. Compared with the integral structure, it can reduce gas consumption and has a significant energy saving effect in long-term continuous production.

[0072] 2. Improved production safety: The split design makes maintenance and operation more convenient. The flow channel can be cleaned or the insulation layer replaced without the need for overall hoisting, avoiding safety hazards in high-temperature operations. The split connection is fastened with bolts, which is reliable and eliminates the risk of aluminum liquid leakage, significantly improving operational safety.

[0073] 3. Improved process stability: The insulation layer can stably maintain the temperature of the molten aluminum, reduce the impact of temperature fluctuations on the filling quality, and ensure that the casting has a dense structure and no cold shut defects; the split structure facilitates regular cleaning of oxide scale and carbon deposits, keeps the flow channels unobstructed, improves production continuity and casting yield, and significantly enhances process stability.

[0074] 4. Reduced maintenance costs of metal molds: The split structure facilitates localized repair and replacement without the need for complete scrapping, extending the lifespan of the distributor, reducing spare parts costs and maintenance expenses, and improving equipment utilization.

[0075] 5. Improved production efficiency: The split design makes mold installation and disassembly more convenient, shortens production preparation time, and improves equipment utilization efficiency. It is especially suitable for the production of aluminum alloy castings using metal mold low-pressure processes.

[0076] The above are merely exemplary embodiments of this application and are not intended to limit the scope of protection of this application, which is determined by the appended claims.

Claims

1. A split metal mold low pressure casting distributor of split structure, characterized in that, include: The upper cover includes a ring-shaped strip with uniform thickness and a plurality of flow channel interfaces evenly arranged along the inner circle of the strip. An inwardly recessed cover plate is provided between the strip and the plurality of flow channel interfaces. A heat insulation layer is provided inside the flow channel interfaces. A plurality of positioning holes and bolt connection ports are provided through the strip. as well as The lower base cavity includes an opening corresponding to the upper cover and a distributor cavity disposed downward along the bottom side of the opening. The inner wall of the distributor cavity is provided with a flow channel corresponding to the flow channel interface. The distributor cavity is coated with a heat insulation layer and has a liquid riser interface at its bottom center. The lower base cavity has a small hole at its opening that corresponds to the positioning hole and bolt connection port of the upper cover. The upper cover and the lower base cavity are detachably connected by bolts.

2. The split-structure metal low-pressure casting distributor according to claim 1, characterized in that, Both the upper cover and the lower base cavity are made of 42CrMo heat-resistant steel, and the thickness of the heat-resistant steel body is 15mm.

3. A split-structure metal low-pressure casting distributor according to claim 2, characterized in that, The upper cover and lower base cavity are manufactured using a combination of casting and machining.

4. A split-structure metal low-pressure casting distributor according to claim 1, characterized in that, The insulation layer is a fiber paste coating, which is made by mixing aluminum silicate fiber, high-temperature binder and water in a mass ratio of 100:15~20:30~40, and the total coating thickness is 15mm.

5. A split-structure metal low-pressure casting distributor according to claim 4, characterized in that, The high-temperature binder is any one of aluminum phosphate, silica sol, and water glass.

6. A split-structure metal low-pressure casting distributor according to claim 1, characterized in that, The opening is a ring-shaped strip that matches the shape and size of the bottom side of the upper cover.

7. A split-structure metal low-pressure casting distributor according to claim 1, characterized in that, The cover plate is formed by two tightly bonded steel bodies.

8. A method of using a split-type metal low-pressure casting distributor as described in any one of claims 1-7, characterized in that, Includes the following steps: S1: Materials for preparing the insulation layer; S2: Coating the insulation layer: The flow channel interface of the upper cover and the inner cavity of the distributor of the lower base are coated in multiple layers. Each layer is 3-5mm thick, and each layer is dried at a low temperature of 100℃ after each coating. Finally, it is baked and cured at 300~400℃. S3: Combine the upper cover and the lower base cavity, fasten them together with bolts, and assemble them into a distributor; S4: Install the mold and distributor: Use a crane to lift the bottom of the mold, place the distributor on the mold, and then tighten it with bolts; S5: Distributor heating: Preheat the distributor and the metal low-pressure casting mold to 150-250℃; S6: Casting filling: Start the low-pressure casting equipment for metal molds, and distribute the castings evenly to each cavity of the external mold through the flow channel formed by the upper and lower molds of the distributor; S7: Remove the casting: After the aluminum liquid has filled and solidified, remove the casting from the external mold.

9. The method of use according to claim 8, characterized in that, Step S1 specifically includes the following steps: first, dry mix the aluminum silicate fiber with the high-temperature binder until uniform, then gradually add water and stir until there is no dry powder or lumps; after standing for 10-15 minutes to mature, it can be used.

10. The method of use according to claim 8, characterized in that, Step S2 specifically includes the following steps: applying the insulation layer material in three coats, each coat being 5mm thick, drying it at a low temperature in a 100℃ oven after each coat, and finally baking it at 300~400℃ for curing.

Images