High temperature die casting mold

Abstract

The application relates to the technical field of die casting moulds, in particular to a high-temperature die casting mould which comprises an upper mould base and a lower mould base, is internally provided with a closed annular heat conduction loop filled with phase change heat conduction medium composed of bismuth-tin-indium alloy particles and argon, and is externally provided with a detachable cooling jacket and a quick plug connector in cooperation with a nano-aluminum nitride coating, a graphite composite sealing ring and a buried thermocouple. The application can uniformly conduct heat, inhibit thermal stress, improve sealing performance, maintainability and service life.

Description

Technical Field

[0001] This utility model relates to the field of die casting mold technology, and in particular to a high-temperature die casting mold. Background Technology

[0002] With the continuous development of die casting technology, high-temperature die casting molds have been widely used in high-precision manufacturing fields such as automobiles, electronics, and aerospace. However, existing high-temperature die casting molds still have many problems in practical applications. For example, traditional molds are difficult to achieve rapid and uniform heat conduction under high-temperature conditions, resulting in large temperature differences and thermal stress concentration inside the mold, which in turn leads to thermal fatigue cracks, casting deformation, or surface defects. At the same time, some cooling structures are complex in design and occupy a large space, affecting the overall compactness and service life of the mold, making it difficult to meet the needs of modern high-efficiency and high-stability die casting production.

[0003] A search revealed a high-temperature heat pipe mold for high-temperature die casting, with publication number CN120480149A and publication date August 15, 2025. This design embeds heat pipe heat exchange components in both the moving and fixed molds, utilizing the phase change of the working fluid inside the heat pipe to achieve efficient heat conduction. While this structure can significantly improve heat conduction speed and shorten preheating time, it relies on a closed capillary structure. During long-term high-temperature cycling, if a micro-leakage occurs in the heat pipe or the working fluid fails, the entire heat exchange system will fail. Furthermore, the fixed embedding position of the heat pipe makes it difficult to flexibly adjust for local hot spots, resulting in high maintenance costs and limited reliability.

[0004] A search revealed a cavity-type high-temperature resistant metal die-casting mold with publication number CN110947927B, authorized on May 6, 2022. This design creates a vacuum heat transfer cavity between the mold plate and the load-bearing plate, combined with an external circulating water tank for heat dissipation. While this design effectively controls mold thickness and increases heat exchange area, it relies heavily on the integrity of the vacuum cavity, requiring extremely high sealing properties during processing and resulting in complex manufacturing processes. Furthermore, once the vacuum cavity is damaged due to thermal fatigue or mechanical impact, it loses its heat conduction function and cannot be repaired online, severely impacting the long-term stable operation of the mold.

[0005] The aforementioned problems indicate that existing high-temperature die-casting molds still suffer from insufficient reliability, complex structure, difficult maintenance, and poor flexibility in local temperature control. Therefore, this invention provides a novel high-temperature die-casting mold that aims to improve structural reliability, maintainability, and the precision of temperature field control while ensuring high thermal conductivity by optimizing the internal heat conduction path and cooling structure layout, thereby meeting the practical needs of modern high-speed, high-quality die-casting production. Utility Model Content

[0006] The purpose of this utility model is to provide a high-temperature die-casting mold to solve the problem mentioned in the background art that the existing high-temperature die-casting molds cause large internal temperature differences and thermal stress concentration due to uneven heat conduction under high-temperature conditions, which in turn leads to thermal fatigue cracks or casting defects. At the same time, it overcomes the defects of existing embedded heat pipes that rely on closed capillary systems, which have the risk of micro-leakage and are difficult to adjust locally, as well as the high sealing requirements of vacuum heat conduction cavities, which fail to conduct heat after damage and are inconvenient to maintain and have limited structural adaptability.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a high-temperature die-casting mold, including an upper mold base and a lower mold base, the upper mold base and the lower mold base being arranged opposite to each other to form a cavity, the upper mold base having a first heat-conducting channel group inside, and the lower mold base having a second heat-conducting channel group inside, the first heat-conducting channel group and the second heat-conducting channel group being continuously connected along the circumference of the cavity in the mold-closed state, forming a closed ring heat-conducting circuit; the first heat-conducting channel group is composed of a plurality of radially distributed first arc-shaped grooves, and the second heat-conducting channel group is composed of a plurality of radially distributed second arc-shaped grooves, each first arc-shaped groove and the corresponding second arc-shaped groove being connected at the mold-closed interface through an end-face insertion structure, the end-face insertion structure including a tenon provided at the end of the first arc-shaped groove and a groove provided at the beginning of the second arc-shaped groove, the tenon being embedded in the groove to form a fluid-sealed connection.

[0008] Preferably, both the first and second heat-conducting channel groups are filled with a phase change heat-conducting medium. The phase change heat-conducting medium is a mixture of metal-based alloy particles with a melting point between 250°C and 350°C and an inert gas. The metal-based alloy particles are bismuth-tin-indium ternary eutectic alloys with a particle size range of 80μm to 150μm. The inert gas is argon, and the filling pressure is 0.15MPa to 0.25MPa. The phase change heat-conducting medium undergoes a solid-liquid phase change within the mold's operating temperature range, absorbing and evenly distributing heat to avoid localized overheating.

[0009] Preferably, a first cooling jacket and a second cooling jacket are respectively provided on the outer sides of the upper mold base and the lower mold base. The first cooling jacket is fixedly connected to the side of the upper mold base away from the cavity, and its inner wall forms a first cooling cavity between the outer wall of the upper mold base and the cavity. The second cooling jacket is fixedly connected to the side of the lower mold base away from the cavity, and its inner wall forms a second cooling cavity between the outer wall of the lower mold base and the cavity. The first cooling cavity and the second cooling cavity are connected through an external circulation pipeline. A centrifugal pump, a plate heat exchanger and a flow regulating valve are sequentially arranged on the circulation pipeline. The coolant is driven by the centrifugal pump to flow through the first cooling cavity and the second cooling cavity, carrying away the heat released by the phase change heat transfer medium.

[0010] Preferably, the first cooling jacket is fixedly connected to the upper mold base by countersunk screws. The countersunk screws are evenly distributed in the circumferential direction, and a locating pin hole is provided between every two adjacent countersunk screws. A stainless steel locating pin is embedded in the locating pin hole. One end of the stainless steel locating pin is interference-fitted to the upper mold base, and the other end is clearance-fitted to the first cooling jacket. The second cooling jacket is connected to the lower mold base in the same way.

[0011] Preferably, sealing ring grooves are respectively provided on the mold closing surfaces of the upper mold base and the lower mold base. The sealing ring grooves surround the cavity and are fitted with graphite composite sealing rings. The graphite composite sealing rings are made by pressing and sintering expanded graphite and nickel powder at a mass ratio of 7:3. The cross-section of the rings is rectangular and the height is 0.1 mm higher than the mold closing surface. When the mold is closed, the rings are deformed under pressure to fill the micro gaps and prevent the phase change heat transfer medium from escaping from the heat transfer channel interface.

[0012] Preferably, the channel walls of the first and second heat-conducting channel groups are coated with a nano-aluminum nitride ceramic coating, the nano-aluminum nitride ceramic coating having a thickness of 30μm to 50μm, and is attached to the inner wall of the channel by a plasma spraying process, thereby improving the heat radiation efficiency and reducing the erosion and wear of the channel wall by metal-based alloy particles.

[0013] Preferably, the upper mold base and the lower mold base are further provided with temperature monitoring components. The temperature monitoring components include multiple embedded thermocouples. The temperature measuring ends of the embedded thermocouples are located 5mm directly below the critical hot spot area of ​​the cavity. The signal leads pass through the side wall of the mold base and are led out to the external data acquisition module for real-time feedback of temperature changes in each area to guide the adjustment of coolant flow.

[0014] Preferably, both the inlet and outlet of the first cooling jacket and the second cooling jacket are provided with quick-connect fittings. Each quick-connect fitting includes a male end and a female end. The male end is fixed to the cooling jacket, and the female end is connected to an external circulation pipeline. The male end is provided with a spring-loaded sealing valve core. When the female end is inserted, it pushes the valve core to open the flow channel. When the female end is pulled out, the valve core automatically closes under the action of the spring to prevent coolant leakage.

[0015] Preferably, the upper mold base and the lower mold base are integrally forged from H13 hot work die steel, and the internal heat conduction channel group is formed by electrical discharge machining. The corners of the channels are rounded with R5 to avoid stress concentration. The phase change heat conduction medium is injected through a special injection hole during the mold preheating stage. After injection, it is sealed with a threaded plug. A copper gasket is provided between the threaded plug and the mold base body to ensure the reliability of the seal at high temperature.

[0016] The beneficial effects of this invention are as follows: By constructing a closed-loop heat conduction circuit and filling it with a reversible phase change heat conduction medium, heat is evenly diffused inside the mold, eliminating local hot spots; the heat conduction channel adopts an end-face plug-in structure to achieve precise docking and sealing of the upper and lower molds, avoiding reliance on the capillary structure of traditional heat pipes; the cooling jacket is independent of the heat conduction system, facilitating disassembly and maintenance, and enabling rapid connection via quick-connect fittings; the nano-coating and graphite sealing ring synergistically enhance durability and sealing performance; the temperature monitoring component provides a data foundation for closed-loop temperature control. Stable assembly is achieved between components through mechanical connections, interference fits, threaded seals, and material property matching, eliminating the need for high-precision welding or vacuum sealing, significantly improving structural adaptability and service life. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a bottom view sectional structural diagram of the present invention; Figure 3 This is a schematic diagram of the combination of the first cooling jacket and the second cooling jacket of this utility model; Figure 4 This is a schematic diagram showing the structure of the first and second cooling chambers of this utility model; Explanation of reference numerals in the attached drawings: 1. Upper mold base; 2. Lower mold base; 3. Cavity; 4. First heat conduction channel group; 5. Second heat conduction channel group; 6. Tenon; 7. Groove; 8. Phase change heat conduction medium; 9. First cooling jacket; 10. Second cooling jacket; 11. First cooling cavity; 12. Second cooling cavity; 13. Countersunk screw; 14. Locating pin hole; 15. Stainless steel locating pin; 16. Sealing ring groove; 17. Graphite composite sealing ring; 18. Nano-aluminum nitride ceramic coating; 19. Embedded thermocouple; 20. Quick-connect connector; 21. Male end; 22. Female end; 23. Threaded plug; 24. Copper gasket; 25. Filling hole. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0019] Specific implementation examples are given below.

[0020] See Figures 1-4The present invention provides a high-temperature die-casting mold, the specific structure and assembly relationship of which are as follows: The mold is composed of an upper mold base 1 and a lower mold base 2, which are arranged opposite each other in the vertical direction and together form a cavity 3 when the mold is closed; the cavity 3 is used to contain molten metal and form the required casting; in order to achieve efficient and uniform heat conduction and heat dissipation, a first heat conduction channel group 4 is opened inside the upper mold base 1, and a second heat conduction channel group 5 is opened inside the lower mold base 2; the first heat conduction channel group 4 and the second heat conduction channel group 5 are continuously connected in the circumferential direction of the cavity 3 when the mold is closed, forming a closed ring heat conduction circuit, so that heat can flow in the circumferential direction throughout the mold and avoid local heat accumulation; The first heat conduction channel group 4 is composed of multiple radially distributed first arc-shaped grooves, and the second heat conduction channel group 5 is composed of multiple radially distributed second arc-shaped grooves. Each first arc-shaped groove and its corresponding second arc-shaped groove are connected at the mold closing interface between the upper mold base 1 and the lower mold base 2 through an end-face insertion structure. The end-face insertion structure includes a tenon 6 at the end of the first arc-shaped groove and a groove 7 at the beginning of the second arc-shaped groove. During the mold closing process, the tenon 6 is embedded in the groove 7 to form a fluid-sealed connection, ensuring that the phase change heat conduction medium 8 filled inside the heat conduction channel will not leak from the interface. The mating surfaces of the tenon 6 and the groove 7 are precision machined, and the surface roughness is controlled below Ra0.8μm to ensure sealing performance and repeatability accuracy. Both the first heat conduction channel group 4 and the second heat conduction channel group 5 are filled with a phase change heat conduction medium 8. The phase change heat conduction medium 8 is a mixture of metal-based alloy particles with a melting point between 250°C and 350°C and an inert gas. The metal-based alloy particles are bismuth-tin-indium ternary eutectic alloys with a particle size range of 80μm to 150μm. The inert gas is argon, and the filling pressure is 0.15MPa to 0.25MPa. The phase change heat conduction medium 8 undergoes a solid-liquid phase change within the mold's working temperature range, absorbing and transferring heat. During the mold preheating stage, the phase change heat conduction medium 8 is injected into the heat conduction channel through a dedicated injection hole 25. After injection, a threaded plug 23 is used for sealing. A copper gasket 24 is provided between the threaded plug 23 and the upper mold base 1 or lower mold base 2 body. The copper gasket 24 has good plastic deformation ability at high temperatures, which can compensate for the small gaps caused by thermal expansion differences, thereby ensuring sealing reliability. A first cooling jacket 9 and a second cooling jacket 10 are respectively provided on the outer sides of the upper mold base 1 and the lower mold base 2. The first cooling jacket 9 is fixedly connected to the side of the upper mold base 1 away from the cavity 3, and its inner wall forms a first cooling cavity 11 between the outer wall of the upper mold base 1 and the inner wall of the upper mold base 1. The second cooling jacket 10 is fixedly connected to the side of the lower mold base 2 away from the cavity 3, and its inner wall forms a second cooling cavity 12 between the outer wall of the lower mold base 2 and the inner wall of the lower mold base 2. The first cooling cavity 11 and the second cooling cavity 12 are connected through an external circulation pipeline, and a centrifugal pump, a plate heat exchanger and a flow regulating valve are sequentially arranged on the circulation pipeline. The coolant flows through the first cooling cavity 11 and the second cooling cavity 12 sequentially under the drive of the centrifugal pump, carrying away the heat released by the phase change heat transfer medium 8 during the condensation process, thereby achieving the regulation of the overall temperature of the mold. The first cooling jacket 9 is fixedly connected to the upper mold base 1 by countersunk screws 13, which are evenly distributed circumferentially. A locating pin hole 14 is provided between every two adjacent countersunk screws 13, and a stainless steel locating pin 15 is embedded in the locating pin hole 14. One end of the stainless steel locating pin 15 is interference-fitted to the upper mold base 1, and the other end is clearance-fitted to the first cooling jacket 9 to limit the displacement of the cooling jacket during thermal expansion and facilitate disassembly and maintenance. The second cooling jacket 10 is connected to the lower mold base 2 in the same way, that is, fixed and positioned by countersunk screws 13 and stainless steel locating pins 15. Sealing ring grooves 16 are respectively provided on the mating surfaces of the upper mold base 1 and the lower mold base 2, and the sealing ring grooves 16 surround the cavity 3; a graphite composite sealing ring 17 is embedded in the sealing ring groove 16. The graphite composite sealing ring 17 is made of expanded graphite and nickel powder pressed and sintered at a mass ratio of 7:3. Its cross-section is rectangular and its height is 0.1mm higher than the mating surface; when the mold is closed, the graphite composite sealing ring 17 undergoes elastic and plastic deformation under pressure, filling the micro gap between the mating surfaces of the upper and lower mold bases and preventing the phase change heat conduction medium 8 from escaping from the heat conduction channel interface; the graphite composite sealing ring 17 has good high-temperature self-lubricating properties and chemical stability, and can work for a long time below 600℃ without failure. The walls of the first heat-conducting channel group 4 and the second heat-conducting channel group 5 are coated with a nano-aluminum nitride ceramic coating 18 with a thickness of 30μm to 50μm. The coating is attached to the inner wall of the channel by plasma spraying. The nano-aluminum nitride ceramic coating 18 has high thermal conductivity and low coefficient of thermal expansion, which can improve the thermal radiation efficiency of the inner wall of the channel, while reducing the erosion and wear of the channel wall by metal-based alloy particles during phase change flow, thus extending the service life of the heat-conducting channel. Temperature monitoring components are also installed inside the upper mold base 1 and the lower mold base 2. These components include multiple embedded thermocouples 19. The temperature measuring ends of the embedded thermocouples 19 are located 5 mm directly below the critical hot spot area of ​​the cavity 3. The signal leads pass through the side wall of the mold base and are led out to the external data acquisition module. The embedded thermocouples 19 are embedded by drilling and sealed with high-temperature glue. Their arrangement is determined according to the simulation of the casting structure and covers the concentrated hot spot area. The real-time temperature data is used to control the opening of the coolant flow regulating valve, thereby dynamically adjusting the cooling intensity and realizing closed-loop control of the mold temperature field. Both the inlet and outlet of the first cooling jacket 9 and the second cooling jacket 10 are equipped with quick-connect fittings 20. The quick-connect fitting 20 includes a male end 21 and a female end 22. The male end 21 is fixed to the cooling jacket body, and the female end 22 is connected to the external circulation pipeline. The male end 21 is equipped with a spring-loaded sealing valve core. When the female end 22 is inserted, it pushes the valve core to open the flow channel, allowing the coolant to flow. When the female end 22 is pulled out, the valve core automatically closes under the action of the spring to prevent coolant leakage. This structure facilitates quick replacement or maintenance of the mold on the production line without having to drain the entire cooling system. The upper mold base 1 and the lower mold base 2 are integrally forged from H13 hot work die steel. After tempering, the material has a hardness of 46-50 HRC and good high-temperature strength and thermal fatigue resistance. The internal heat conduction channel group is formed by electrical discharge machining. The corners of the channels are rounded with R5 to avoid stress concentration caused by sharp corners. The inner wall of the channel after electrical discharge machining is sandblasted to improve the coating adhesion, and then the nano aluminum nitride ceramic coating 18 is sprayed. In the actual die-casting production process, the mold is first preheated to above 250°C by an external heating device. At this time, the phase change heat transfer medium 8 begins to melt and fill the entire closed-loop heat transfer circuit. When the high-temperature molten metal is injected into the cavity 3, the local area heats up rapidly. The phase change heat transfer medium 8 absorbs heat and melts in this area and flows to the lower temperature area through the heat transfer circuit, distributing the heat evenly during the flow. When the overall temperature of the mold rises to the upper limit of the phase change temperature, the phase change heat transfer medium 8 is completely in a liquid state, and the heat is continuously transferred to the cooling jacket through the heat transfer circuit. The coolant circulates in the first cooling chamber 11 and the second cooling chamber 12, carrying away the heat, causing the phase change heat transfer medium 8 to condense and release heat in the area away from the heat source, and re-enter the solid state, completing a complete thermal cycle. During this process, the embedded thermocouple 19 monitors the temperature of each area in real time, and the data acquisition module transmits the signal to the PLC control system. The PLC adjusts the opening of the flow regulating valve according to the preset temperature control strategy to change the coolant flow rate, thereby accurately controlling the temperature distribution of the mold. Because the heat conduction channel adopts an end-face plug-in structure instead of a closed capillary system, it does not rely on a complex internal capillary core structure, avoiding the performance degradation problem caused by micro-leakage in traditional heat pipes. At the same time, the heat conduction channel is completely separated from the cooling system, and the cooling jacket can be disassembled independently, which is convenient for cleaning, replacement or maintenance, significantly improving the maintainability of the mold. The graphite composite sealing ring 17 and the threaded plug 23, together with the copper gasket 24, form a multi-level sealing system to ensure that the phase change heat conduction medium 8 does not leak under high temperature and high pressure conditions. The nano aluminum nitride ceramic coating 18 not only improves the heat radiation efficiency, but also effectively resists the erosion of metal particles and extends the service life of the channel. The combination of stainless steel positioning pin 15 and countersunk screw 13 ensures the installation accuracy of the cooling jacket and adapts to the dimensional changes caused by thermal expansion, avoiding loosening or deformation of the connection due to thermal stress. In summary, this invention utilizes a combination of multiple technologies, including a closed-loop heat conduction circuit, a reversible phase-change heat conduction medium, an independent cooling jacket, a multi-stage sealing structure, a temperature monitoring and feedback system, and a wear-resistant coating, to construct a high-temperature die-casting mold that is structurally reliable, thermally efficient, and easy to maintain. This effectively solves problems such as thermal stress concentration, thermal fatigue cracks, and casting defects caused by uneven heat conduction in existing technologies. To better enable those skilled in the art to fully understand and implement this invention, the following section provides further details on its specific implementation principles using a particular application scenario. On the automotive engine block die-casting production line, the operator first installs the upper mold base 1 and the lower mold base 2 onto the moving mold and fixed mold mounting plates of the die-casting machine, respectively. Before mold closing, a phase change heat transfer medium 8 is injected into the first heat conduction channel group 4 through the injection hole 25 on the upper mold base 1 using a special injection device. This medium is a mixture of bismuth-tin-indium ternary eutectic alloy particles with a particle size of 100μm and 0.2MPa argon gas. Then, the threaded plug 23 is tightened, causing the copper gasket 24 to undergo initial plastic deformation under the thread preload, forming a primary seal. Similarly, the second heat conduction channel group 5 of the lower mold base 2 is filled and sealed. At this time, the heat conduction channels inside the upper mold base 1 and the lower mold base 2 are in a closed state, but are not yet connected. During the mold closing process, the upper mold base 1 descends vertically, and the tenon 6 at the end of its first arc groove aligns with the groove 7 at the beginning of the second arc groove of the lower mold base 2. When the mold closing force reaches the set value, the tenon 6 is fully embedded in the groove 7, and the mating surfaces (surface roughness Ra 0.4 μm) of the two are tightly fitted to form a fluid sealing interface, so that the first heat conduction channel group 4 and the second heat conduction channel group 5 are connected in the circumferential direction along the cavity 3, forming a complete closed ring heat conduction circuit. At the same time, the mold closing surfaces of the upper mold base 1 and the lower mold base 2 press against each other, so that the graphite composite sealing ring 17 in the sealing ring groove 16 is deformed by pressure, and the part that is 0.1 mm higher than the mold closing surface is compressed to fill the micro gap between the upper and lower mold bases, preventing the phase change heat conduction medium 8 from leaking out from the heat conduction channel interface along the mold closing surface. During the mold preheating stage, an external electric heating device heats the entire mold to 280°C. At this time, the bismuth-tin-indium alloy particles in the phase change heat transfer medium 8 begin to melt, and the liquid metal fills the entire closed-loop heat transfer circuit under the pressure of argon gas. When the molten aluminum alloy (temperature approximately 680°C) is injected into the cavity 3, the temperature of the mold wall near the gate area rapidly rises to over 350°C. The phase change heat transfer medium 8 in this area absorbs a large amount of heat and completely liquefies, reducing its density. Under the combined action of thermal buoyancy and pressure gradient, it flows along the first heat transfer channel group 4 and the second heat transfer channel group 5 to the lower temperature area. During the flow, heat is efficiently transferred through the high thermal conductivity wall surface of the nano-aluminum nitride ceramic coating 18, while the coating has a low coefficient of thermal expansion (4.5×10⁻⁻⁴). 6 / ℃) and H13 steel matrix (11.5×10⁻ 6 ( / ℃) forms a thermal stress buffer to prevent coating peeling; On the back side of the mold away from the heat source, the first cooling jacket 9 and the second cooling jacket 10 have been installed with countersunk screws 13 and stainless steel locating pins 15. One end of the stainless steel locating pin 15 is press-fitted into the locating pin hole 14 of the upper mold base 1, and the other end has a 0.05mm gap to fit the first cooling jacket 9, allowing the cooling jacket to move radially without generating constraint stress during thermal expansion. The external circulation pipeline is connected to the cooling jacket through a quick-connect fitting 20: after the female end 22 is inserted into the male end 21, it pushes the spring-loaded sealing valve core to open, and the coolant (50% ethylene glycol aqueous solution) flows through the first cooling chamber 11 and the second cooling chamber 12 in sequence under the drive of the centrifugal pump. The coolant absorbs the latent heat released by the phase change heat transfer medium 8 in the condensation zone, causing it to re-solidify into solid particles, completing the phase change cycle. Embedded thermocouple 19 monitors the temperature 5mm below the hot spot area at the bottom of cavity 3 in real time, and the signal is transmitted to the PLC control system via a lead wire. When the temperature of a certain area exceeds the set upper limit (such as 320℃), the PLC outputs a signal to adjust the opening of the flow regulating valve, increase the coolant flow rate, and enhance the heat dissipation of that area; conversely, it reduces the flow rate to avoid overcooling. This closed-loop control ensures that the temperature field fluctuation of the mold is controlled within ±10℃. When the cooling system needs to be replaced or maintained, the operator only needs to pull out the female end 22 of the quick connector 20. The internal spring will push the sealing valve core to reset and close the flow channel to prevent coolant leakage. Then, loosen the countersunk screw 13 to remove the first cooling jacket 9 as a whole without draining the pipeline or disassembling the mold base body. The phase change heat transfer medium 8 inside the heat transfer channel is sealed in a closed loop and is not affected by the disassembly of the cooling jacket, thus maintaining the integrity of the system. In summary, through the above steps, this utility model achieves reliable connection of the heat conduction channel, efficient heat transfer of the phase change medium, independent maintainability of the cooling system, and dynamic control of the temperature field in the actual die casting process. All components work together, solving the technical problems of uneven heat conduction and poor structural adaptability.

[0021] All contents not described in detail in the specification are existing technologies known to those skilled in the art, and the model parameters of each electrical appliance are not specifically limited; conventional equipment can be used. Electrical control components not mentioned in this technical solution are not shown in the figures because they are existing technologies, and will not be described here.

[0022] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A high-temperature die-casting mold, comprising an upper mold base (1) and a lower mold base (2), wherein the upper mold base (1) and the lower mold base (2) are arranged opposite to each other to form a cavity (3), characterized in that: The upper mold base (1) has a first heat conduction channel group (4) inside, and the lower mold base (2) has a second heat conduction channel group (5) inside. The first heat conduction channel group (4) and the second heat conduction channel group (5) are continuously connected along the circumference of the cavity (3) in the mold closing state to form a closed ring heat conduction circuit. The first heat conduction channel group (4) is composed of multiple radially distributed first arc grooves, and the second heat conduction channel group (5) is composed of multiple radially distributed second arc grooves. Each first arc groove and the corresponding second arc groove are connected at the mold closing interface through an end face insertion structure. The end face insertion structure includes a tenon (6) set at the end of the first arc groove and a groove (7) set at the beginning of the second arc groove. The tenon (6) is embedded in the groove (7) to form a fluid-sealed connection.

2. The high-temperature die-casting mold according to claim 1, characterized in that: Both the first heat conduction channel group (4) and the second heat conduction channel group (5) are filled with a phase change heat conduction medium (8). The phase change heat conduction medium (8) is a mixture of metal-based alloy particles with a melting point between 250°C and 350°C and an inert gas. The metal-based alloy particles are bismuth-tin-indium ternary eutectic alloys with a particle size of 80μm to 150μm. The inert gas is argon, and the filling pressure is 0.15MPa to 0.25MPa.

3. The high-temperature die-casting mold according to claim 1, characterized in that: The upper mold base (1) and the lower mold base (2) are respectively provided with a first cooling jacket (9) and a second cooling jacket (10). The first cooling jacket (9) is fixedly connected to the side of the upper mold base (1) away from the cavity (3), and its inner wall forms a first cooling cavity (11) between the outer wall of the upper mold base (1). The second cooling jacket (10) is fixedly connected to the side of the lower mold base (2) away from the cavity (3), and its inner wall forms a second cooling cavity (12) between the outer wall of the lower mold base (2). The first cooling cavity (11) and the second cooling cavity (12) are connected through an external circulation pipeline.

4. The high-temperature die-casting mold according to claim 3, characterized in that: The first cooling jacket (9) is fixedly connected to the upper mold base (1) by countersunk screws (13). The countersunk screws (13) are evenly distributed along the circumference. A positioning pin hole (14) is provided between every two adjacent countersunk screws (13). A stainless steel positioning pin (15) is embedded in the positioning pin hole (14). One end of the stainless steel positioning pin (15) is interference-fitted to the upper mold base (1), and the other end is clearance-fitted to the first cooling jacket (9). The second cooling jacket (10) and the lower mold base (2) are connected in the same way.

5. The high-temperature die-casting mold according to claim 1, characterized in that: Sealing ring grooves (16) are respectively provided on the mold closing surfaces of the upper mold base (1) and the lower mold base (2). The sealing ring grooves (16) surround the cavity (3). A graphite composite sealing ring (17) is embedded in the sealing ring grooves (16). The graphite composite sealing ring (17) is made by pressing and sintering expanded graphite and nickel powder at a mass ratio of 7:

3. Its cross-section is rectangular and its height is 0.1 mm higher than the mold closing surface.

6. The high-temperature die-casting mold according to claim 1, characterized in that: The channel walls of the first heat-conducting channel group (4) and the second heat-conducting channel group (5) are coated with a nano-aluminum nitride ceramic coating (18), the thickness of which is 30μm to 50μm.

7. The high-temperature die-casting mold according to claim 1, characterized in that: Temperature monitoring components are provided inside the upper mold base (1) and the lower mold base (2). The temperature monitoring components include multiple embedded thermocouples (19). The temperature measuring ends of the embedded thermocouples (19) are located 5 mm directly below the key hot spot area of ​​the cavity (3). The signal leads pass through the side wall of the mold base and are led out to the external data acquisition module.

8. The high-temperature die-casting mold according to claim 3, characterized in that: The first cooling jacket (9) and the second cooling jacket (10) are equipped with quick-connect connectors (20) at their inlet and outlet. The quick-connect connector (20) includes a male end (21) and a female end (22). The male end (21) is fixed to the cooling jacket, and the female end (22) is connected to the external circulation pipeline. The male end (21) is equipped with a spring-loaded sealing valve core inside. When the female end (22) is inserted, it pushes the valve core to open the flow channel. When it is pulled out, the valve core automatically closes under the action of the spring.

9. The high-temperature die-casting mold according to claim 1, characterized in that: The upper mold base (1) and the lower mold base (2) are integrally forged from H13 hot work die steel. The internal heat conduction channel group is formed by electrical discharge machining, and the corner of the channel is transitioned with R5 rounded corners.

10. The high-temperature die-casting mold according to claim 2, characterized in that: The phase change heat transfer medium (8) is injected into the heat transfer channel group through the injection hole (25). After injection, it is sealed with a threaded plug (23). A copper gasket (24) is provided between the threaded plug (23) and the upper mold base (1) or lower mold base (2) body.

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