A complex sand core gas generation and local temperature coupling control device

Abstract

A complex sand core gas generation and local temperature coupling control device is disclosed. The device comprises a central control cabinet, a circulating machine, a water tank, a vacuum pump, sand core exhaust and heat dissipation pipes, and conformal patch. The central control cabinet is connected to the circulating machine, vacuum pump, and pouring control system. The main body of the central control cabinet is a central control computer and a PLC electrical control system, used to receive pouring signals and control the circulating machine and vacuum pump. The circulating machine has an internal cooling system; its inlet is connected to the water tank, and its outlet is connected to the inlet of the sand core exhaust and heat dissipation pipes. One end of the water tank is connected to the circulating machine, and the other end is connected to the outlet of the sand core exhaust and heat dissipation pipes. The main body of the sand core exhaust and heat dissipation pipes is a copper pipe, with its middle section tightly fitted to the conformal patch. This device can solve the problems of existing sand casting technology, such as the inability to achieve local temperature field control in complex irregular internal cavities and the inability to timely discharge gas generated from the end sand core, producing high-quality cores that meet the forming and quality requirements of complex internal cavities in high-end aluminum alloy castings.

Description

Technical Field

[0001] This invention belongs to the field of casting technology, specifically relating to a complex sand core gas generation and local temperature coupling control device. Background Technology

[0002] To minimize component weight and maximize performance, high-end aluminum alloy castings such as aero-engine casings and tank cylinder blocks and heads employ an integrated structural design concept. These castings have exceptionally complex internal structures, containing numerous irregularly shaped closed cavities with wall thicknesses of 3–5 mm, subject to stringent quality and pressure requirements. Sand casting technology is a key forming technology for the mass production of these complex high-end aluminum alloy castings. Through mold structure design, complex cores are prepared using molds or 3D printing methods. Chips, runners, and risers are used to control the temperature field during the solidification process, ensuring adequate cooling in localized areas. Venting is achieved through methods such as pre-embedded venting ropes and 3D-printed hollow sand cores. After the overall mold assembly is completed, gravity or low-pressure casting is used to pour the casting.

[0003] The above methods can ensure the overall quality and forming of high-end aluminum alloy castings. However, for extremely complex or fine curved structures in the internal cavity of the casting, as well as a large number of complex isolated sand cores, chills cannot be used for rapid cooling. The reasons are: (1) The size of the chills is severely limited, and the temperature rises rapidly after contact with the high-temperature alloy liquid, which cannot achieve the chilling effect. The aluminum chills may also melt and embed themselves in the casting. (2) The chills in the internal cavity cannot be removed during the cleaning process. (3) The sand cores are not strong enough to support the weight of the chills. In addition, the irregular structure design of the internal cavity of the casting results in the weak strength of the sand core in this area, which makes it impossible to use venting ropes or hollow sand cores, resulting in gas escaping at the end of the sand core and forming pores inside the casting.

[0004] This invention relates to a device and application for controlling gas generation and local temperature coupling in complex sand cores. It not only meets the requirements for controlling the local temperature field in complex cavities of castings, rapidly extracting gas generated at the end of the sand core under heat, and achieving coupled control of sand core gas generation and local temperature field coupling during the casting solidification process, but also serves as a core reinforcement to enhance the overall structural strength of the sand core, preventing it from weakening after heating and breaking due to erosion by molten aluminum or buoyancy. Ultimately, it achieves complete forming of complex internal cavities in castings and control over internal quality and microstructure properties. Summary of the Invention

[0005] To ensure the forming, metallurgical quality, and microstructure properties of complex internal cavities in high-end aluminum alloy castings such as aero-engine casings and tank cylinder blocks and heads, and to solve the problems of existing sand casting technology, such as the inability to control the local temperature field of complex irregular internal cavities and the inability to timely discharge gas generated at the end of the sand core, this invention provides a complex sand core gas generation and local temperature coupling control device, as well as a method for using this device to control sand core gas generation and local temperature coupling.

[0006] The technical solution of this invention is as follows:

[0007] A complex sand core gas generation and local temperature coupling control device, characterized in that: the device comprises a central control cabinet, a circulating machine, a water tank, a vacuum pump, sand core exhaust and heat dissipation pipes, and conformal patches, wherein:

[0008] The central control cabinet is connected to the circulation machine, vacuum pump and pouring control system. The main body of the central control cabinet is a central control computer and a PLC electrical control system, which are used to receive pouring signals and control the circulation machine and vacuum pump.

[0009] The circulating machine is designed with a cooling system inside. Its liquid inlet is connected to the water tank, and its liquid outlet is connected to the liquid inlet of the sand core exhaust heat dissipation pipe.

[0010] One end of the water tank is connected to the circulation machine, and the other end is connected to the liquid outlet of the sand core exhaust and heat dissipation pipe.

[0011] The main body of the sand core exhaust heat dissipation pipe is a copper pipe, with its middle section tightly fitted with a conformal patch.

[0012] As a preferred technical solution:

[0013] The middle section of the sand core exhaust heat dissipation pipe is an S-shaped flat copper tube, while the other parts are circular copper tubes. One end of the circular copper tube is the liquid inlet, and the other end is the liquid outlet. The sand core exhaust heat dissipation pipe is bent in the middle. After bending, one end of the sand core exhaust heat dissipation pipe is an S-shaped flat copper tube that fits tightly with the conformal patch, and the other end is the liquid inlet and the liquid outlet. The circular copper tube is covered with spiral fan-shaped heat dissipation fins, and the covering surface is coated with thermal grease. The heat dissipation fins are wrapped with a mesh breathable mesh to form an integrated heat dissipation and exhaust pipe. The sand core exhaust heat dissipation pipe is also equipped with an exhaust port.

[0014] The heat dissipation fins are made of aluminum, with a single fin thickness of 0.5mm; the ventilation mesh is made of high-temperature resistant material (steel or fiberglass can be selected), with a mesh size of 10-50 mesh and 1-3 layers.

[0015] The conformal patch is made of aluminum or copper, with an overall thickness of 5-15mm. The front of the conformal patch is in contact with the high-temperature alloy liquid in the cavity and is CNC machined into the same shape as the inner cavity structure of the casting. The back is flat and fits tightly with the S-shaped flat copper tube.

[0016] The back of the conformal patch is bonded to a multi-channel closed heat pipe with mercury as the working medium, and the cold end of the multi-channel closed heat pipe then contacts an S-shaped flat copper tube.

[0017] After the S-shaped flat copper tube is welded to the 2mm thick copper sheet, it is then attached to the back of the conformal patch. Thermal grease is applied to the bonding surface to enhance thermal conductivity, making it easy to disassemble during casting cleaning.

[0018] The inlet end of the circulating machine is equipped with a flow sensor and a temperature sensor. The flow sensor and temperature sensor communicate with the central control cabinet in real time and adjust the flow rate and temperature of the circulating machine coolant according to the settings of the central control cabinet.

[0019] Temperature sensors are designed at the interface between the water tank and the sand core exhaust heat dissipation pipe, as well as inside the water tank, to monitor the return temperature and the coolant temperature in the water tank in real time and provide feedback to the central control cabinet in real time.

[0020] The present invention also provides a method for gas generation and local temperature coupling control of complex sand cores using the above-mentioned device, characterized by the following specific steps:

[0021] 1) Assembly of sand core exhaust heat dissipation pipe: Connect the S-shaped flat copper tube with the conformal patch. Apply thermal grease to the contact surface of the two and other parts of the S-shaped flat copper tube. Except for the S-shaped flat copper tube, the other parts are covered with spiral fan-shaped heat dissipation fins. After the heat dissipation fins are wrapped with a breathable mesh, the sand core exhaust heat dissipation pipe is formed. Connect the copper tubes at both ends of the pipe to the sealing joints respectively.

[0022] 2) Complex core preparation: The conformal patch is attached to the mold, and the sand core exhaust and heat dissipation pipes are embedded inside the core by manual sand filling or mechanical core shooting. After the sand core has solidified, the core with the sand core exhaust and heat dissipation pipes is removed, the area around the conformal patch is cleaned, and paint is applied.

[0023] 3) Molding assembly and device connection: Install the core inside the integral mold, ensuring that the entire sand core exhaust and heat dissipation pipe is located in the sand core and does not come into contact with the alloy liquid. The sand core exhaust and heat dissipation pipe extends directly from the inside of the sand core to the outside of the mold. Connect the liquid inlet to the circulation machine, the liquid outlet to the water tank, and the exhaust port to the vacuum pump.

[0024] 4) Temperature field and sand core gas generation control during casting pouring process; After the mold is assembled, pouring begins. The central control cabinet receives the signal from the pouring control system and controls the circulation machine and vacuum pump to start, inject coolant into the sand core exhaust and heat dissipation pipe, and evacuate the outside of the pipe to extract the gas in the sand core in time. At the same time, the flow rate of coolant is controlled until the casting solidifies.

[0025] 5) Equipment disassembly and cleaning: After the casting has solidified, the circulating machine and vacuum pump stop running. The connection between the circulating machine, water tank and sand core exhaust and heat dissipation pipe is disconnected. The mold is transferred to the cleaning workshop for cleaning. The sand core exhaust and heat dissipation pipe is removed. At the same time, the circulating machine and water tank are connected to the sand core exhaust and heat dissipation pipe in the next mold to prepare for the next pouring.

[0026] As a preferred technical solution, if it is necessary to control the temperature of the conformal patch during the casting solidification process to be below 100°C, the circulating machine can be a chiller, and the coolant is softened water with added anti-corrosion substances; if it is necessary to control the temperature of the conformal patch during the casting solidification process to be above 200°C, the conformal patch needs to be bonded to a multi-channel closed heat pipe with mercury as the working medium, and then the cold end of the multi-channel closed heat pipe contacts the S-shaped flat copper tube.

[0027] As a preferred technical solution: after the copper pipe in the sand core exhaust heat dissipation pipe is connected to the circulation machine and the water tank, the liquid inlet and liquid outlet can be sealed. A vacuum pump is used to extract air from the outlet, forming a negative pressure inside the sand core exhaust heat dissipation pipe and the core to enhance exhaust.

[0028] The device described in this invention can solve the problems of exhaust and regional cooling of castings with enclosed cavities, and is particularly suitable for manufacturing aero-engine casing castings or cylinder head castings.

[0029] The beneficial effects of this invention are reflected in:

[0030] (1) The solution described in this invention can realize automated temperature field control in the complex cavity inside the casting, ensuring that the temperature of the conformal patch remains constant or changes according to the set temperature curve during the entire alloy solidification process, thereby ensuring the internal quality, structure and performance of the casting.

[0031] (2) The solution described in this invention can extract the gas generated by the heating at the end of the sand core in the inner cavity of the casting in a timely manner, and prevent the gas from entering the alloy and forming pores.

[0032] (3) The solution described in this invention can serve as a core for complex irregular sand cores, providing support for weak areas of complex sand cores during the molding and casting process.

[0033] (4) The solution described in this invention does not require placing chills inside the sand core or pre-embedding exhaust ropes. The device has a high degree of integration, is easy to disassemble after casting, and the exhaust and heat dissipation pipes inside the casting cavity are easy to clean and can be reused.

[0034] (5) The solution described in this invention can realize fully automated operation. The entire temperature field control and evacuation process are automatically completed after the central control cabinet receives the pouring signal. The operation process is highly stable and can ensure the quality stability of the inner cavity of the casting.

[0035] (6) This invention has no special requirements for the mold structure, site, or casting equipment. Conventional equipment can meet the requirements. It has the advantages of high efficiency, high integration, and low cost. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of a complex sand core gas generation and local temperature coupling control device.

[0037] Figure 2 This is a schematic diagram showing the placement of the exhaust and heat dissipation pipes inside the sand core.

[0038] Figure 3 This is a schematic diagram of the overall structure of the sand core exhaust and heat dissipation pipe.

[0039] Figure 4 This is a schematic diagram of the overall structure of the sand core exhaust and heat dissipation pipe.

[0040] Figure 5 This is a schematic diagram of the internal heat dissipation fin structure of the sand core exhaust heat dissipation pipe.

[0041] Figure 6 Schematic diagram of a flat copper tube structure.

[0042] Figure 7 Comparison of subcutaneous pores and pinholes in the airway wall (characterized by fluorescence detection), wherein: (a) without using the device of the present invention, and (b) after using the device of the present invention.

[0043] Figure 8 Comparison of secondary dendrite arm distance effects in airway wall tissue (characterized by fluorescence detection), wherein: (a) without the device of the present invention (59 μm), (b) after using the device of the present invention (23 μm).

[0044] Figure 9 Comparison of the quality of the central flange of a thin-walled complex casing casting, wherein: (a) without the device of the present invention (penetrating pores), (b) with the device of the present invention (good quality).

[0045] Attached reference numerals: 1. Central control cabinet, 2. Casting mold, 3. Circulator, 4. Water tank, 5. Vacuum pump, 6. Casting control system, 7. Sand core exhaust and heat dissipation pipe, 21. Core, 71. Liquid inlet, 72. Liquid outlet, 73. Exhaust port, 74. Flat copper tube, 75. Conformal patch, 76. Ventilation mesh, 77. Heat dissipation fins. Detailed Implementation

[0046] like Figures 1-6 As shown, a complex sand core gas generation and local temperature coupling control device comprises a central control cabinet 1, a circulation machine 3, a water tank 4, a vacuum pump 5, a sand core exhaust heat dissipation pipe 7, and a conformal patch 75, wherein:

[0047] The central control cabinet 1 is connected to the circulating machine 3, the vacuum pump 5 and the pouring control system 6. The main body of the central control cabinet 1 is a central control computer and a PLC electrical control system, which is used to receive pouring signals and control the circulating machine 3 and the vacuum pump 5.

[0048] The circulating machine 3 is internally designed with a cooling system. Its inlet end is connected to the water tank 4, and its outlet end is connected to the inlet 71 of the sand core exhaust heat dissipation pipe 7. The inlet end of the circulating machine 3 is equipped with a flow sensor and a temperature sensor. The flow sensor and temperature sensor communicate with the central control cabinet 1 in real time and adjust the flow rate and temperature of the circulating machine 3 according to the settings of the central control cabinet 1.

[0049] One end of the water tank 4 is connected to the circulator 3, and the other end is connected to the outlet 72 of the sand core exhaust heat dissipation pipe 7. Temperature sensors are designed at the interface between the water tank 4 and the sand core exhaust heat dissipation pipe 7 and inside the water tank 4 to monitor the return temperature and the coolant temperature in the water tank 4 in real time and to provide real-time feedback to the central control cabinet 1.

[0050] The main body of the sand core exhaust heat dissipation pipe 7 is a copper pipe. The middle section is an S-shaped flat copper pipe 74, and the other parts are circular copper pipes. One end of the circular copper pipe is an inlet 71, and the other end is an outlet 72. The sand core exhaust heat dissipation pipe 7 is bent in the middle. One end of the bent sand core exhaust heat dissipation pipe 7 is an S-shaped flat copper pipe 74 that fits tightly with the conformal patch 75. The other end is an inlet 71 and an outlet 72. The circular copper pipe is covered with spiral fan-shaped heat dissipation fins 77. The covering surface is coated with thermal grease. The heat dissipation fins 77 are wrapped with a breathable mesh 76 to form an integrated heat dissipation exhaust pipe. The sand core exhaust heat dissipation pipe 7 is also provided with an exhaust port 73, which is connected to the vacuum pump 5.

[0051] The conformal patch 75 is made of aluminum or copper and has an overall thickness of 5-15mm. The front side of the conformal patch 75 is in contact with the high-temperature alloy liquid in the cavity and has the same structure as the inner cavity of the casting. The back side is flat and fits tightly with the S-shaped flat copper tube 74.

[0052] The breathable mesh 76 is made of high-temperature resistant material, with a mesh size of 10-50 meshes and 1-3 layers.

[0053] The heat dissipation fins 77 are made of aluminum, with a single fin thickness of 0.5 mm.

[0054] If it is necessary to control the temperature of the conformal patch 75 during the solidification process of the casting to be below 100℃, the circulating machine 3 can be a chiller, and the coolant is softened water with added anti-corrosion substances; if it is necessary to control the temperature of the conformal patch 75 during the solidification process of the casting to be above 200℃, the conformal patch 75 needs to be bonded to a multi-channel closed heat pipe with mercury as the working medium, and then the cold end of the multi-channel closed heat pipe contacts the S-shaped flat copper tube 74.

[0055] The S-shaped flat copper tube 74 can also be soldered to a 2mm thick copper sheet and then bonded to the back of the conformal patch 75, with thermal grease applied to the bonding surface to enhance thermal conductivity.

[0056] Example 1

[0057] This embodiment describes the preparation and casting process of the cylinder head inner core for an armored vehicle. The specific steps are as follows:

[0058] 1) Assembly of sand core exhaust heat dissipation pipe 7: Connect S-shaped flat copper tube 74 with conformal patch 75. Apply thermal grease to the contact surface of the two and other parts of the S-shaped flat copper tube 74. Except for the S-shaped flat copper tube 74, other parts are covered with spiral fan-shaped heat dissipation fins 77. After the heat dissipation fins 77 are wrapped with a breathable mesh 76, the sand core exhaust heat dissipation pipe 7 is formed. Connect the copper tubes at both ends of the pipe to the sealing joints respectively.

[0059] 2) Preparation of complex core 21: The conformal patch 75 is attached to the mold, and the sand core exhaust and heat dissipation pipe 7 is embedded inside the core 21 by manual sand filling or mechanical core shooting. After the sand core is cured, the core 21 with the sand core exhaust and heat dissipation pipe 7 embedded is removed, the area around the conformal patch 75 is cleaned, and paint is applied.

[0060] 3) Molding assembly and device connection: The core 21 with the sand core exhaust heat dissipation pipe 7 embedded is installed inside the integral mold 2, ensuring that the entire sand core exhaust heat dissipation pipe 7 is located in the sand core and does not come into contact with the alloy liquid. The sand core exhaust heat dissipation pipe 7 extends directly from the inside of the sand core to the outside of the mold 2. The liquid inlet 71 is connected to the circulation machine 3, the liquid outlet 72 is connected to the water tank 4, and the exhaust port 73 is connected to the vacuum pump 5.

[0061] 4) Temperature field and sand core gas generation control during casting pouring process; After the mold 2 is completed, pouring begins. The central control cabinet 1 receives the signal from the pouring control system 6 and controls the circulation machine 3 and vacuum pump 5 to start, inject coolant into the sand core exhaust heat dissipation pipe 7, and evacuate the outside of the pipe to extract the gas in the sand core in time. At the same time, the flow rate of coolant is controlled until the casting solidifies.

[0062] 5) Equipment disassembly and cleaning: After the casting has solidified, the circulating machine 3 and vacuum pump 5 stop operating. The connection between the circulating machine 3, water tank 4 and sand core exhaust heat dissipation pipe 7 is disconnected. The mold 2 is transferred to the cleaning workshop for cleaning. The sand core exhaust heat dissipation pipe 7 is removed. At the same time, the circulating machine 3 and water tank 4 are connected to the sand core exhaust heat dissipation pipe 7 in the next mold 2, in preparation for the next pouring.

[0063] like Figure 7 , 8 As shown, due to gas generation from the sand core / coating and slow solidification and cooling of the alloy, the inner cavity air passage wall and water jacket core area of ​​the cylinder head casting have a large number of subcutaneous pores larger than 0.2 mm on the surface, with pinhole grades reaching 3 to 5. The alloy microstructure in this area is coarse, with secondary dendrite arm distances approaching 60 μm. Based on the design of conformal patch shapes according to the air passage wall and water jacket core structure, after rapid cooling using the above-mentioned scheme, the subcutaneous pores in the air passage wall and water jacket core areas are significantly improved, with pinhole grades reaching 1. The alloy microstructure in the area is refined to an extremely significant degree, with secondary dendrite arm distances as low as 23 μm.

[0064] Example 2

[0065] This embodiment describes the preparation and casting process of the irregularly shaped sand core inside the casing of a certain type of aero-engine. The specific steps are as follows:

[0066] 1) Assembly of sand core exhaust heat dissipation pipe 7: Connect S-shaped flat copper tube 74 with conformal patch 75. Apply thermal grease to the contact surface of the two and other parts of the S-shaped flat copper tube 74. Except for the S-shaped flat copper tube 74, other parts are covered with spiral fan-shaped heat dissipation fins 77. After the heat dissipation fins 77 are wrapped with a breathable mesh 76, the sand core exhaust heat dissipation pipe 7 is formed. Connect the copper tubes at both ends of the pipe to the sealing joints respectively.

[0067] 2) Preparation of complex core 21: The conformal patch 75 is attached to the mold, and the sand core exhaust and heat dissipation pipe 7 is embedded inside the core 21 by manual sand filling or mechanical core shooting. After the sand core is cured, the core 21 with the sand core exhaust and heat dissipation pipe 7 embedded is removed, the area around the conformal patch 75 is cleaned, and paint is applied.

[0068] 3) Molding assembly and device connection: Install the core 21 inside the integral mold 2 to ensure that the entire sand core exhaust and heat dissipation pipe 7 is located in the sand core and does not come into contact with the alloy liquid. The sand core exhaust and heat dissipation pipe 7 extends directly from the inside of the sand core to the outside of the mold 2. Connect the liquid inlet 71 to the circulation machine 3, the liquid outlet 72 to the water tank 4, and the exhaust port 73 to the vacuum pump 5.

[0069] 4) Temperature field and sand core gas generation control during casting pouring process; After the mold 2 is completed, pouring begins. The central control cabinet 1 receives the signal from the pouring control system 6 and controls the circulation machine 3 and vacuum pump 5 to start, inject coolant into the sand core exhaust heat dissipation pipe 7, and evacuate the outside of the pipe to extract the gas in the sand core in time. At the same time, the flow rate of coolant is controlled until the casting solidifies.

[0070] 5) Equipment disassembly and cleaning: After the casting has solidified, the circulating machine 3 and vacuum pump 5 stop operating. The connection between the circulating machine 3, water tank 4 and sand core exhaust heat dissipation pipe 7 is disconnected. The mold 2 is transferred to the cleaning workshop for cleaning. The sand core exhaust heat dissipation pipe 7 is removed. At the same time, the circulating machine 3 and water tank 4 are connected to the sand core exhaust heat dissipation pipe 7 in the next mold 2, in preparation for the next pouring.

[0071] like Figure 9 As shown, the central flange of a thin-walled complex casing casting has a closed internal cavity structure. During the casting process, the sand core in this closed cavity generates gas due to heat, which cannot be expelled in time. The alloy above the sand core is locally overheated, resulting in slow solidification and frequent penetrating pores or porosity defects in the central flange area, with defect levels of 3 to 4. Applying the device of this invention to the inner core of this closed cavity, by conforming the conformal patch to the molten metal in the flange area and rapidly cooling it, completely eliminates the above-mentioned defects.

[0072] Matters not covered in this invention are common knowledge.

[0073] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A complex sand core gas generation and local temperature coupling control device, characterized in that: The device consists of a central control cabinet (1), a circulation machine (3), a water tank (4), a vacuum pump (5), a sand core exhaust and heat dissipation pipe (7), and conformal patches (75), wherein: The central control cabinet (1) is connected to the circulating machine (3), vacuum pump (5) and casting control system (6). The main body of the central control cabinet (1) is a central control computer and a PLC electrical control system, which is used to receive casting signals and control the circulating machine (3) and vacuum pump (5). The circulating machine (3) is designed with a cooling system inside. Its liquid inlet is connected to the water tank (4), and its liquid outlet is connected to the liquid inlet (71) of the sand core exhaust heat dissipation pipe (7). One end of the water tank (4) is connected to the circulating machine (3), and the other end is connected to the outlet (72) of the sand core exhaust heat dissipation pipe (7); The middle section of the sand core exhaust heat dissipation pipe (7) is an S-shaped flat pipe, and the other parts are round copper pipes. One end of the round copper pipe is the liquid inlet (71), and the other end is the liquid outlet (72). The outside of the round copper pipe is covered with spiral fan-shaped heat dissipation fins (77). The heat dissipation fins (77) are made of aluminum, with a single fin thickness of 0.5mm. The covering surface is coated with thermal grease. The heat dissipation fins (77) are wrapped with 1 to 3 layers of mesh breathable mesh (76) made of high temperature resistant material with a mesh size of 10 to 50 meshes, forming an overall heat dissipation exhaust pipe. The sand core exhaust heat dissipation pipe (7) is also provided with an exhaust port (73). The back of the conformal patch (75) is bonded to a multi-channel closed heat pipe with mercury as the working medium, and the cold end of the multi-channel closed heat pipe is in contact with an S-shaped flat copper tube (74). The specific steps are as follows: 1) Assembly of sand core exhaust heat dissipation pipe (7): Connect the S-shaped flat copper tube (74) to the conformal patch (75). Apply thermal grease to the contact surface of the two and other parts of the S-shaped flat copper tube (74). Except for the S-shaped flat copper tube (74), the other parts are covered with spiral fan-shaped heat dissipation fins (77). After the heat dissipation fins (77) are wrapped with a breathable mesh (76), the sand core exhaust heat dissipation pipe (7) is formed. Connect the copper tubes at both ends of the pipe to the sealing joints respectively. 2) Preparation of complex core (21): The conformal patch (75) is attached to the mold. The sand core exhaust heat dissipation pipe (7) is embedded into the core (21) by manual sand filling or mechanical core shooting. After the sand core is cured, the core (21) with the sand core exhaust heat dissipation pipe (7) is removed. The area around the conformal patch (75) is cleaned and coated. 3) Molding assembly and device connection: Install the core (21) inside the integral mold (2) to ensure that the entire sand core exhaust heat dissipation pipe (7) is located in the sand core and does not come into contact with the alloy liquid. The sand core exhaust heat dissipation pipe (7) extends directly from the inside of the sand core to the outside of the mold (2). Connect the liquid inlet (71) to the circulation machine (3), the liquid outlet (72) to the water tank (4), and the exhaust port (73) to the vacuum pump (5). 4) Temperature field and sand core gas generation control during casting pouring process; After the mold (2) is assembled, pouring begins. The central control cabinet (1) receives the signal from the pouring control system (6) and controls the circulation machine (3) and vacuum pump (5) to start, inject coolant into the sand core exhaust heat dissipation pipe (7), and evacuate the outside of the pipe to extract the gas in the sand core in time. At the same time, the flow rate of coolant is controlled until the casting solidifies. 5) Equipment disassembly and cleaning: After the casting has solidified, the circulating machine (3) and vacuum pump (5) stop running. Disconnect the circulating machine (3), water tank (4) from the sand core exhaust heat dissipation pipe (7), transfer the mold (2) to the cleaning workshop for cleaning, remove the sand core exhaust heat dissipation pipe (7), and connect the circulating machine (3) and water tank (4) to the sand core exhaust heat dissipation pipe (7) in the next mold (2) to prepare for the next pouring.

2. The complex sand core gas generation and local temperature coupling control device according to claim 1, characterized in that: The conformal patch (75) is made of aluminum or copper and has an overall thickness of 5 to 15 mm. The front of the conformal patch (75) is the same as the inner cavity structure of the casting, and the back is a flat surface that fits tightly with the S-shaped flat copper tube (74).

3. The complex sand core gas generation and local temperature coupling control device according to claim 1, characterized in that: The inlet end of the circulating machine (3) is equipped with a flow sensor and a temperature sensor. The flow sensor and temperature sensor communicate with the central control cabinet (1) in real time and adjust the flow rate and temperature of the coolant in the circulating machine (3) according to the settings of the central control cabinet (1).

4. The complex sand core gas generation and local temperature coupling control device according to claim 1, characterized in that: Temperature sensors are designed at the interface between the water tank (4) and the sand core exhaust heat dissipation pipe (7) and inside the water tank (4) to monitor the return temperature and the coolant temperature in the water tank (4) in real time and provide real-time feedback to the central control cabinet (1).

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