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

Abstract

The application discloses a complex sand core gas evolution and local temperature coupling control device which is composed of a central control cabinet, a circulating machine, a water tank, a vacuum pump, a sand core exhaust heat dissipation pipeline and a conformal patch, wherein the central control cabinet is connected with the circulating machine, the vacuum pump and a pouring control system, the main body of the central control cabinet is a central control computer and a PLC electric control system, and the central control cabinet is used for receiving a pouring signal and controlling the circulating machine and the vacuum pump; a cooling system is arranged in the circulating machine, a liquid inlet end of the cooling system is connected with the water tank, and a liquid outlet end of the cooling system is connected with a liquid inlet of the sand core exhaust heat dissipation pipeline; one end of the water tank is connected with the circulating machine, and the other end of the water tank is connected with a liquid outlet of the sand core exhaust heat dissipation pipeline; and the main body of the sand core exhaust heat dissipation pipeline is a copper pipeline, and the middle section of the copper pipeline is tightly attached to the conformal patch. The device can solve the problems that the existing sand casting technology cannot realize the local temperature field control of complex irregular inner cavities, the end sand core gas evolution cannot be discharged in time and the like, and high-quality cores which meet the complex inner cavity forming and quality requirements of high-end aluminum alloy castings can be produced.

Description

Technical Field

[0001] The invention belongs to the technical field of casting, and in particular relates to a complex sand core gas generation and local temperature coupling control device. Background Art

[0002] In order to reduce the weight of components as much as possible and improve the performance of components, high-end aluminum alloy castings such as aircraft engine casings, tank cylinder blocks and cylinder heads all adopt an integrated structural design concept. The inner cavity structure of the casting is extremely complex, with a large number of special-shaped closed cavities. The cavity wall thickness is 3 to 5 mm, and there are strict quality and pressure requirements. Sand casting technology is a key forming technology for mass production of such complex high-end aluminum alloy castings. Through the design of the casting structure, complex cores are prepared by molds or 3DP methods, and the temperature field of the casting solidification process is regulated by chills, runners, and risers to ensure local cooling conditions. Sand mold exhaust is achieved by pre-embedded exhaust ropes, 3D printed hollow sand cores, etc. After the overall casting assembly is completed, gravity or low-pressure casting is used to complete the casting.

[0003] The above method can ensure the overall quality and forming of high-end aluminum alloy castings. However, for extremely complex or fine curved structures in the inner cavity of the casting, as well as a large number of complex isolated sand cores, it is impossible to use chilled iron for quenching. The reasons are: (1) The size of the chilled iron is severely limited. After contacting the high-temperature alloy liquid, the temperature rises rapidly and cannot achieve the quenching effect. The aluminum chilled iron may also be partially melted and embedded in the casting; (2) During the cleaning process, the inner cavity chilled iron cannot be removed; (3) The sand core is not strong enough to support the weight of the chilled iron. In addition, the design of the local special-shaped structure of the inner cavity of the casting makes the sand core in this area weak, and it is impossible to use exhaust ropes or hollow sand cores, resulting in the formation of pores inside the casting by gas emission at the end of the sand core.

[0004] The present invention relates to a complex sand core gas generation and local temperature coupling control device and application, which can not only meet the local temperature field control requirements of the complex cavity of the casting, quickly extract the gas generated by the heat at the end of the sand core, and realize the sand core gas generation and local temperature field coupling control during the solidification process of the casting, but also can serve as a core bone to enhance the overall structural strength of the sand core, prevent the sand core from reducing its strength after being heated, and prevent it from being washed by aluminum liquid or broken by buoyancy. Finally, the complete forming of the complex inner cavity of the casting and the control of the internal quality and organizational performance are achieved. Summary of the invention

[0005] In order to ensure the complex inner cavity forming, metallurgical quality and organizational properties of high-end aluminum alloy castings such as aircraft engine casings, tank cylinder blocks and cylinder heads, and to solve the problems that the existing sand casting technology cannot achieve local temperature field control of complex and special-shaped inner cavities, and the end sand core gas cannot be discharged in time, and to produce high-quality cores that meet the complex inner cavity forming and quality requirements of high-end aluminum alloy castings, the present invention provides a complex sand core gas generation and local temperature coupling control device, and a method for sand core gas generation and local temperature coupling control using the device.

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

[0007] A complex sand core gas generation and local temperature coupling control device, characterized in that the device is composed of a central control cabinet, a circulation machine, a water tank, a vacuum pump, a sand core exhaust and heat dissipation pipeline, and a conformal patch, 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 the central control computer and PLC electronic control system, which are used to receive pouring signals and control the circulation machine and vacuum pump;

[0009] The circulation machine is designed with a cooling system inside, the liquid inlet end of which is connected to the water tank, and the liquid outlet end is connected to the liquid inlet of the sand core exhaust and heat dissipation pipeline;

[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 pipeline;

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

[0012] As the preferred technical solution:

[0013] The middle section of the sand core exhaust and heat dissipation duct is an S-shaped flat copper tube, and the other parts are round copper tubes, one end of the round copper tube is a liquid inlet, and the other end is a liquid outlet. The sand core exhaust and heat dissipation duct is bent in the middle, and one end of the bent sand core exhaust and heat dissipation duct is an S-shaped flat copper tube that fits tightly with the conformal patch, and the other end is a liquid inlet and a liquid outlet. The outside of the round copper tube is covered with spiral fan-shaped heat dissipation fins, and the covering surface is coated with thermal grease. The outside of the heat dissipation fins is wrapped with a mesh breathable net to form an overall heat dissipation exhaust pipeline, and an exhaust port is also provided on the sand core exhaust and heat dissipation duct.

[0014] The heat dissipation fin is made of aluminum, and the thickness of a single fin is 0.5 mm; the air permeable net is made of a high temperature resistant material (steel or glass fiber can be selected), and the mesh size is 10 to 50 meshes, and 1 to 3 layers are provided.

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

[0016] The back side of the conformable patch is attached to a multi-channel closed heat pipe whose working medium is mercury, and the cold end of the multi-channel closed heat pipe is in contact with the S-shaped flat copper tube.

[0017] The S-shaped flat copper tube is welded to the 2mm thick copper sheet and then bonded to the back of the conformal patch. Thermal grease is applied to the bonding surface to enhance thermal conductivity and facilitate disassembly when cleaning the casting.

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

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

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

[0021] 1) Assembly of sand core exhaust heat dissipation pipe: connect the S-shaped flat copper tube and the conformal patch, apply thermal grease to the fitting surface of the two and the surfaces of other parts of the S-shaped flat copper tube, and wrap the spiral fan-shaped heat dissipation fins on the other parts except the S-shaped flat copper tube. Wrap the air-permeable net outside the heat dissipation fin to form a sand core exhaust heat dissipation pipe, and connect the copper pipes at both ends of the pipe to the sealing joints respectively;

[0022] 2) Preparation of complex cores: fit the conformable patch to the mold, and use manual sand filling or mechanical core shooting to bury the sand core exhaust and heat dissipation pipeline as a whole into the core. After the sand core is cured, take out the core with the sand core exhaust and heat dissipation pipeline buried, clean the area near the conformable patch, and apply paint;

[0023] 3) Molding assembly and device connection: Install the core inside the integral casting mold, ensure that the entire sand core exhaust and heat dissipation pipeline is located in the sand core and does not contact the alloy liquid. The sand core exhaust and heat dissipation pipeline extends directly from the inside of the sand core to the outside of the casting 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 process: After the casting mold is assembled, pouring begins. The central control cabinet receives the signal from the casting control system, controls the circulator and vacuum pump to start, injects coolant into the sand core exhaust and heat dissipation pipeline, and evacuates the periphery of the pipeline to timely extract the gas in the sand core. At the same time, the coolant flow rate is controlled until the casting is solidified;

[0025] 5) Equipment disassembly and cleaning: After the casting solidifies, the circulation machine and vacuum pump stop running, disconnect the circulation machine, water tank and sand core exhaust and heat dissipation pipe, transfer the mold to the cleaning workshop for cleaning, take out the sand core exhaust and heat dissipation pipe, and connect the circulation machine, water tank and 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 conformable patch during the solidification process of the casting to be below 100°C, the circulator can use a chiller, and the coolant is softened water with anti-corrosion substances added; if it is necessary to control the temperature of the conformable patch during the solidification process of the casting to be above 200°C, the conformable patch needs to be bonded to a multi-way closed heat pipe whose working medium is mercury, and then the cold end of the multi-way closed heat pipe is in contact with the S-shaped flat copper tube.

[0027] As an optimal technical solution: after the copper tube in the sand core exhaust and heat dissipation pipeline is connected to the circulation machine and the water tank, the liquid inlet and outlet can be blocked, and a vacuum pump is used to evacuate the air outlet to form a negative pressure in the sand core exhaust and heat dissipation pipeline and inside the core to enhance exhaust.

[0028] The device of the present invention can solve the exhaust and regional cooling problems of castings with closed cavities, and is particularly suitable for preparing aircraft engine casing castings or cylinder head castings.

[0029] The beneficial effects of the present invention are embodied in:

[0030] (1) The solution of the present invention can realize automatic control of the temperature field in the complex cavity inside the casting, ensuring that the temperature of the patch is 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 of the present invention can timely extract the gas generated by the heat at the end of the sand core in the inner cavity of the casting, thereby preventing the gas from entering the alloy and forming pores.

[0032] (3) The solution of the present invention can be used as the core bone of complex and special-shaped sand cores, and can support the weak areas of the complex sand cores during the molding and pouring processes.

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

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

[0035] (6) The present invention has no special requirements for the mold structure, site, and pouring equipment. Conventional equipment can meet the requirements and has the advantages of high efficiency, high integration, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

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

[0042] Figure 7 Comparison of the effects of subcutaneous pores and pinholes in the airway wall (characterized by fluorescence detection), where: (a) before using the device of the present invention, (b) after using the device of the present invention.

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

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

[0045] Figure numerals: 1. Central control cabinet, 2. Casting mold, 3. Circulation machine, 4. Water tank, 5. Vacuum pump, 6. Casting control system, 7. Sand core exhaust and heat dissipation pipeline, 21. Core, 71. Liquid inlet, 72. Liquid outlet, 73. Exhaust port, 74. Flat copper tube, 75. Conformal patch, 76. Breathable net, 77. Heat dissipation fins. DETAILED DESCRIPTION

[0046] like Figures 1 to 6 As shown, a complex sand core gas generation and local temperature coupling control device is composed 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 pipeline 7, and a conformal patch 75, wherein:

[0047] The central control cabinet 1 is connected to the circulation 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 electronic control system, which are used to receive pouring signals and control the circulation machine 3 and the vacuum pump 5;

[0048] A cooling system is designed inside the circulation machine 3, whose liquid inlet end is connected to the water tank 4, and whose liquid outlet end is connected to the liquid inlet 71 of the sand core exhaust and heat dissipation pipeline 7; a flow sensor and a temperature sensor are provided at the liquid inlet end of the circulation machine 3, and the flow sensor and the temperature sensor communicate with the central control cabinet 1 in real time, and adjust the coolant flow and temperature of the circulation machine 3 according to the setting of the central control cabinet 1;

[0049] One end of the water tank 4 is connected to the circulation machine 3, and the other end is connected to the liquid outlet 72 of the sand core exhaust and heat dissipation pipeline 7; the interface between the water tank 4 and the sand core exhaust and heat dissipation pipeline 7 and the inside of the water tank 4 are designed with temperature sensors for real-time monitoring of the return temperature and the temperature of the coolant in the water tank 4, and real-time feedback to the central control cabinet 1;

[0050] The main body of the sand core exhaust heat dissipation pipeline 7 is a copper pipeline, the middle section of which is an S-shaped flat copper tube 74, and the other parts are round copper tubes, one end of the round copper tube is a liquid inlet 71, and the other end is a liquid outlet 72. The sand core exhaust heat dissipation pipeline 7 is bent from the middle, and one end of the bent sand core exhaust heat dissipation pipeline 7 is an S-shaped flat copper tube 74 that fits tightly with the conformal patch 75, and the other end is a liquid inlet 71 and a liquid outlet 72. The outside of the round copper tube is coated with spiral fan-shaped heat dissipation fins 77, and the coating surface is coated with thermal grease. The outside of the heat dissipation fins 77 is wrapped with a breathable mesh 76 to form an overall heat dissipation exhaust pipeline. The sand core exhaust heat dissipation pipeline 7 is also provided with an exhaust port 73, and the exhaust port 73 is connected to the vacuum pump 5.

[0051] The conformable patch 75 is made of aluminum or copper, with an overall thickness of 5 to 15 mm. The front side of the conformable patch 75 contacts 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 air permeable net 76 is made of a high temperature resistant material, has a mesh size of 10 to 50 meshes, and is provided with 1 to 3 layers.

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

[0054] If it is necessary to control the temperature of the conformable patch 75 during the solidification process of the casting to be below 100°C, the circulator 3 can use a chiller, and the coolant is softened water with anti-corrosion substances added; if it is necessary to control the temperature of the conformable patch 75 during the solidification process of the casting to be above 200°C, the conformable patch 75 needs to be bonded to a multi-way closed heat pipe whose working medium is mercury, and then the cold end of the multi-way closed heat pipe is in contact with the S-shaped flat copper tube 74.

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

[0056] Example 1

[0057] This embodiment is a process for preparing the inner core of a cylinder head of an armored vehicle and pouring a casting, and the specific steps are as follows:

[0058] 1) Assembling the sand core exhaust heat dissipation pipe 7: connect the S-shaped flat copper tube 74 and the conformal patch 75, apply thermal grease to the bonding surfaces of the two and the surfaces of other parts of the S-shaped flat copper tube 74, and wrap the spiral fan-shaped heat dissipation fins 77 on the other parts except the S-shaped flat copper tube 74. Wrap the air permeable net 76 on the outside of the heat dissipation fins 77 to form the sand core exhaust heat dissipation pipe 7, and connect the copper pipes at both ends of the pipe to the sealing joints respectively;

[0059] 2) Preparation of complex core 21: Fit the conformable patch 75 to the mold, and use manual sand filling or mechanical core shooting to bury the sand core exhaust and heat dissipation pipeline 7 as a whole into the core 21. After the sand core is cured, take out the core 21 with the sand core exhaust and heat dissipation pipeline 7, clean the area near the conformable patch 75, and apply paint;

[0060] 3) Molding assembly and device connection: Install the core 21 with the buried sand core exhaust and heat dissipation pipeline 7 inside the integral casting mold 2, ensure that the entire sand core exhaust and heat dissipation pipeline 7 is located in the sand core and does not contact the alloy liquid, the sand core exhaust and heat dissipation pipeline 7 extends directly from the inside of the sand core to the outside of the casting mold 2, connect the liquid inlet 71 to the circulation machine 3, connect the liquid outlet 72 to the water tank 4, and connect the exhaust port 73 to the vacuum pump 5;

[0061] 4) Temperature field and sand core gas generation control during casting process: After the casting mold 2 is formed, pouring begins, and the central control cabinet 1 receives the signal from the casting control system 6, controls the circulator 3 and the vacuum pump 5 to start, injects coolant into the sand core exhaust and heat dissipation pipeline 7, and evacuates the periphery of the pipeline to timely extract the gas in the sand core, and at the same time controls the coolant flow rate until the casting is solidified;

[0062] 5) Equipment disassembly and cleaning: After the casting is solidified, the circulation machine 3 and the vacuum pump 5 stop running, the circulation machine 3, the water tank 4 and the sand core exhaust and heat dissipation duct 7 are disconnected, the casting mold 2 is transported to the cleaning workshop for cleaning, the sand core exhaust and heat dissipation duct 7 is taken out, and at the same time, the circulation machine 3, the water tank 4 are connected to the sand core exhaust and heat dissipation duct 7 in the next casting mold 2, preparing for the next pouring.

[0063] like Figure 7 , 8 As shown in the figure, due to the gas generation of sand core / coating and slow solidification and cooling of alloy, there are a large number of subcutaneous pores larger than 0.2mm on the surface of the inner cavity airway wall and water jacket core area of ​​the cylinder head casting, and the pinhole grade reaches 3 to 5 levels. The alloy structure in this area is coarse, and the secondary dendrite arm distance is nearly 60μm. The shape of the conformal patch is designed according to the airway wall and water jacket core structure. After quenching with the above scheme, the subcutaneous pores in the airway wall and water jacket core area are significantly improved, the pinhole grade reaches 1, the regional alloy structure refinement effect is extremely obvious, and the secondary dendrite arm distance is only 23μm.

[0064] Example 2

[0065] This embodiment is a process for preparing a special-shaped sand core inside a certain type of aircraft engine casing and casting, and the specific steps are as follows:

[0066] 1) Assembling the sand core exhaust heat dissipation pipe 7: connect the S-shaped flat copper tube 74 and the conformal patch 75, apply thermal grease to the bonding surfaces of the two and the surfaces of other parts of the S-shaped flat copper tube 74, and wrap the spiral fan-shaped heat dissipation fins 77 on the other parts except the S-shaped flat copper tube 74. Wrap the air permeable net 76 on the outside of the heat dissipation fins 77 to form the sand core exhaust heat dissipation pipe 7, and connect the copper pipes at both ends of the pipe to the sealing joints respectively;

[0067] 2) Preparation of complex core 21: Fit the conformable patch 75 to the mold, and use manual sand filling or mechanical core shooting to bury the sand core exhaust and heat dissipation pipeline 7 as a whole into the core 21. After the sand core is cured, take out the core 21 with the sand core exhaust and heat dissipation pipeline 7, clean the area near the conformable patch 75, and apply paint;

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

[0069] 4) Temperature field and sand core gas generation control during casting process: After the casting mold 2 is formed, pouring begins, and the central control cabinet 1 receives the signal from the casting control system 6, controls the circulator 3 and the vacuum pump 5 to start, injects coolant into the sand core exhaust and heat dissipation pipeline 7, and evacuates the periphery of the pipeline to timely extract the gas in the sand core, and at the same time controls the coolant flow rate until the casting is solidified;

[0070] 5) Equipment disassembly and cleaning: After the casting is solidified, the circulation machine 3 and the vacuum pump 5 stop running, the circulation machine 3, the water tank 4 and the sand core exhaust and heat dissipation duct 7 are disconnected, the casting mold 2 is transported to the cleaning workshop for cleaning, the sand core exhaust and heat dissipation duct 7 is taken out, and at the same time, the circulation machine 3, the water tank 4 are connected to the sand core exhaust and heat dissipation duct 7 in the next casting mold 2, preparing for the next pouring.

[0071] like Fig. 9 As shown, there is a closed inner cavity structure inside the central large flange of the thin-walled complex casing casting. During the pouring process, the closed cavity sand core is heated and the gas cannot be removed in time. The alloy above the sand core is locally overheated and the solidification speed is slow, resulting in frequent penetrating pores or loose defects in the central flange area, with defect levels 3 to 4. The device of the present invention is applied to the closed cavity core, and the above defects are completely eliminated by bonding the conformable patch to the metal liquid in the flange area and rapidly cooling it.

[0072] Matters not covered by the present invention are known technologies.

[0073] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for coupling control of gas generation and local temperature of complex sand cores, characterized in that: The device is composed 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 pipeline (7), and a conformal patch (75), wherein: The central control cabinet (1) is connected to the circulation 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 electronic control system, which are used to receive pouring signals and control the circulation machine (3) and the vacuum pump (5); The circulation machine (3) is internally designed with a cooling system, the liquid inlet end of which is connected to the water tank (4), and the liquid outlet end of which is connected to the liquid inlet (71) of the sand core exhaust and heat dissipation pipeline (7); One end of the water tank (4) is connected to the circulation machine (3), and the other end is connected to the liquid outlet (72) of the sand core exhaust and heat dissipation pipeline (7); The main body of the sand core exhaust and heat dissipation pipeline (7) is a copper pipeline, and the middle section thereof is tightly fitted with the conformable patch (75).

2. The device for controlling gas generation and local temperature coupling of complex sand cores according to claim 1, characterized in that: The middle section of the sand core exhaust and heat dissipation pipeline (7) is an S-shaped flat copper tube (74), and the other parts are round copper tubes. One end of the round copper tube is a liquid inlet (71), and the other end is a liquid outlet (72). The sand core exhaust and heat dissipation pipeline (7) is bent from the middle. One end of the bent sand core exhaust and heat dissipation pipeline (7) is an S-shaped flat copper tube (74) tightly fitted with the conformal patch (75), and the other end is a liquid inlet (71) and a liquid outlet (72). The outside of the round copper tube is coated with spiral fan-shaped heat dissipation fins (77), and the coating surface is coated with thermal grease. The outside of the heat dissipation fins (77) is wrapped with a mesh air permeable net (76) to form an integral heat dissipation and exhaust pipeline. The sand core exhaust and heat dissipation pipeline (7) is also provided with an exhaust port (73).

3. The device for controlling gas generation and local temperature coupling of complex sand cores according to claim 2, characterized in that: The heat dissipation fins (77) are made of aluminum, and the thickness of a single fin is 0.5 mm; the air permeable net (76) is made of a high temperature resistant material, and has a mesh size of 10 to 50 meshes, and is provided with 1 to 3 layers.

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

5. The device for controlling gas generation and local temperature coupling of complex sand cores according to claim 4, characterized in that: The back side of the conformable patch (75) is bonded to a multi-channel closed heat pipe whose working medium is mercury, and the cold end of the multi-channel closed heat pipe is in contact with the S-shaped flat copper tube (74).

6. The device for controlling gas generation and local temperature coupling of complex sand cores according to claim 4, characterized in that: After the S-shaped flat copper tube (74) is welded to the 2 mm thick copper sheet, it is then bonded to the back of the conformable patch (75), and thermal grease is applied to the bonding surface.

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

8. The device for controlling gas generation and local temperature coupling of complex sand cores 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 pipeline (7) and inside the water tank (4) for real-time monitoring of the return temperature and the temperature of the coolant in the water tank (4) and for real-time feedback to the central control cabinet (1).

9. A method for controlling gas generation and local temperature coupling of complex sand cores using the device of claim 1, characterized in that: The specific steps are as follows: 1) Assembling the sand core exhaust heat dissipation pipeline (7): connecting the S-shaped flat copper tube (74) and the conformal patch (75), applying thermal grease to the bonding surfaces of the two and the surfaces of other parts of the S-shaped flat copper tube (74), and covering the other parts with spiral fan-shaped heat dissipation fins (77) except the S-shaped flat copper tube (74). The heat dissipation fins (77) are wrapped with a breathable net (76) to form a sand core exhaust heat dissipation pipeline (7), and connecting the copper tubes at both ends of the pipeline with sealing joints respectively; 2) Preparation of a complex core (21); fitting the conformable patch (75) to the mold, embedding the sand core exhaust and heat dissipation pipeline (7) as a whole into the core (21) by artificial sand filling or mechanical core shooting, and after the sand core is solidified, taking out the core (21) with the sand core exhaust and heat dissipation pipeline (7) embedded therein, cleaning the vicinity of the conformable patch (75), and applying paint; 3) Molding assembly and device connection: the core (21) is installed inside the integral casting mold (2), ensuring that the entire sand core exhaust and heat dissipation pipeline (7) is located in the sand core and does not contact the alloy liquid, the sand core exhaust and heat dissipation pipeline (7) extends directly from the inside of the sand core to the outside of the casting 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); 4) Control of the temperature field and gas emission of the sand core during the casting process; after the casting mold (2) is assembled, the casting begins, and the central control cabinet (1) receives a signal from the casting control system (6), controls the circulator (3) and the vacuum pump (5) to start, inject coolant into the sand core exhaust and heat dissipation pipeline (7), and evacuate the periphery of the pipeline to timely extract the gas in the sand core, and at the same time control the coolant flow rate until the casting is solidified; 5) Equipment disassembly and cleaning: After the casting is solidified, the circulation machine (3) and the vacuum pump (5) are stopped, the circulation machine (3), the water tank (4) and the sand core exhaust and heat dissipation pipe (7) are disconnected, the casting mold (2) is transported to the cleaning workshop for cleaning, the sand core exhaust and heat dissipation pipe (7) is taken out, and at the same time, the circulation machine (3), the water tank (4) and the sand core exhaust and heat dissipation pipe (7) in the next casting mold (2) are connected to prepare for the next pouring.

10. An application of the complex sand core gas generation and local temperature coupling control device according to claim 1, characterized in that: The device is used for preparing aircraft engine casing castings or cylinder head castings.

Images