Local efficient cooling device and method for investment casting shell

Abstract

The invention provides a local efficient cooling device and method for an investment casting shell, and the device comprises an air cooling channel which is arranged on the outer surface of the area, needing to be cooled, of the shell; the air cooling channel is provided with an air inlet channel opening and an exhaust channel opening. The air flow controller is respectively connected with the air inlet channel opening and the air outlet channel opening; the gas source is used for providing a gas medium for cooling, the gas source is connected with the gas flow controller, and the gas flow controller is used for controlling gas cooling parameters; and the temperature controller is connected with the air flow controller, and the temperature controller is used for controlling the air flow controller according to the temperature of the shell and the investment casting process parameters to alternately carry out vacuumizing and air inflation in the air cooling channel, so that the purpose of cooling the shell is achieved. According to the application, the cooling speed and the cooling timeliness of the local area of the ceramic shell in investment casting can be improved.

Description

Technical Field

[0001] This application relates to the field of materials processing, and more specifically, to a localized high-efficiency cooling device and method for investment casting shells. Background Technology

[0002] Investment casting is an effective method for producing complex and precision castings. It is characterized by low cost and short cycle time in mass production, and has always held an important position in industrial production. With the development of equipment, castings are evolving towards more integrated, larger, and more complex structures, with increasingly higher requirements for strength and reliability, and decreasing tolerance for defects such as porosity. In large and complex castings, thick-walled areas solidify slowly, easily becoming hot spots that lead to porosity and coarse grains, resulting in low strength and reliability in these areas, and even causing the casting to be scrapped. Improving the heat dissipation capacity of the mold shell in these areas and accelerating the solidification rate of the melt are effective methods to reduce porosity and refine grain size. However, in conventional casting, methods to increase the cooling rate of castings include adding chills and using cold air to blow the mold shell. In investment casting, chills, due to their high thermal conductivity, can increase the cooling rate of the melt to some extent, but due to their low heat capacity, the cooling effect is limited and the adjustment capability is poor. Blowing cold air onto the surface of the mold shell can increase the heat transfer coefficient at the shell / environment interface and accelerate the cooling rate. However, due to the low thermal conductivity and thickness of ceramic mold shells, the adjustment speed of the melt temperature is severely lagging, and the cooling effect is not significant, making it difficult to control the local temperature of the shell. Therefore, it is particularly necessary to develop a shell heat dissipation method with local temperature regulation capability, high cooling efficiency, and fast temperature response speed.

[0003] A search revealed a Chinese invention patent with publication number CN118492337A, which discloses a directional solidification furnace and its preparation method for preparing single-crystal high-temperature alloy castings. The directional solidification furnace includes a furnace body with a melt chamber and a solidification chamber that are thermally isolated from each other. The melt chamber is located at the top of the solidification chamber. The melt chamber has an outer heating element and a central heat-conducting column. The solidification chamber has an outer water-cooling ring and a central cooling column. A first vent hole for outputting inert gas is formed on the central heat-conducting column, and a second vent hole for outputting inert gas is formed on the central cooling column, enabling airflow convection within the melt chamber and / or solidification chamber. This patent is for the production of single-crystal and directional high-temperature alloy castings and cannot be applied to the production of high-temperature alloy castings. Furthermore, the directional solidification furnace adds a water-cooling ring to the outer surface of the mold shell and applies inert gas between them to promote thermal convection between the water-cooling ring and the outer surface of the mold shell, thereby reducing the temperature of the mold shell. However, this method still relies on heat conduction to transfer heat from the inside of the mold shell to the outer surface and then dissipate it into the air. This patent uses a cooling system for the entire mold shell surrounded by a water-cooling ring, which cannot achieve temperature control in localized areas.

[0004] Chinese invention patent application CN118527634A discloses a ceramic mold shell for pressure-regulating casting, its manufacturing method, and a high-temperature alloy thin-walled casting. In the manufacturing of the mold shell, the mold shell model has a conformal cooling system. During the anti-gravity pressure-regulating casting filling simulation, water vapor or inert gas at a preset temperature is introduced into the conformal cooling system. This patent specifies that the ceramic mold shell is manufactured using 3D printing, and the temperature of the mold shell is reduced by introducing a cooling medium into the conformal cooling system; the heat transfer method remains heat conduction. Summary of the Invention

[0005] In view of one of the deficiencies in the prior art, the purpose of this application is to provide a localized high-efficiency cooling device and method for investment casting shells.

[0006] A first aspect of this application provides a localized high-efficiency cooling device for investment casting shells, comprising: An air-cooling channel is located on the outer surface of the area of ​​the shell that needs to be cooled; the air-cooling channel has an air inlet and an air outlet. An airflow controller is connected to the air intake port and the exhaust port, respectively; A gas source is used to provide a cooling gas medium. The gas source is connected to the airflow controller, which is used to control the gas cooling parameters. A temperature controller is connected to the airflow controller. The temperature controller is used to control the airflow controller to alternate between vacuuming and air filling in the air cooling channel according to the temperature of the mold shell and the investment casting process parameters, so as to achieve the purpose of cooling the mold shell.

[0007] Optionally, an air intake channel is provided between the airflow controller and the air intake port, and an air intake channel valve is provided on the air intake channel; an exhaust channel is provided between the airflow controller and the exhaust port, and an exhaust channel valve is provided on the exhaust channel.

[0008] Optionally, the gas medium provided by the gas source is air or water vapor.

[0009] Optionally, the gas cooling parameters include at least one of the following: gas vacuum in the gas cooling channel, gas pressure at the inlet of the gas channel, gas temperature, gas flow rate, gas flow interruption, and the duration and frequency of gas flow interruption.

[0010] Optionally, the surface dimensions of the air-cooling channel are adapted to the surface dimensions of the area of ​​the shell that needs to be cooled.

[0011] A second aspect of this application provides a method for localized, efficient cooling of an investment casting shell, comprising: Provide the above-mentioned localized high-efficiency cooling device for investment casting shells; Set the investment casting process parameters; According to the process parameters, the shell is placed in a baking furnace, slowly heated to the target temperature and kept warm; According to the process parameters, the temperature controller sends a shell cooling command to the airflow controller. The airflow controller draws cooling medium from the air source and introduces it into the air cooling channel to cool the shell. When the shell temperature in the thick-walled area drops to the preset temperature, the gas cooling parameters are adjusted to keep the shell in that area at the preset temperature. The molten alloy is poured into the mold according to the casting process; During the solidification process, the gas cooling parameters are adjusted according to the process parameters to control the cooling rate of the shell in the thick-walled area of ​​the casting, thereby obtaining the target casting.

[0012] Optionally, the process parameters include: high-temperature alloy melt pouring temperature, overall shell firing temperature, shell temperature in thick-walled areas, cooling rate of shell in thick-walled areas during solidification, cooling gas medium temperature, charging pressure, vacuuming-charging frequency, and vacuum degree.

[0013] Optionally, the airflow controller draws cooling medium from the air source and introduces it into the air-cooling channel to cool the housing, comprising: The airflow controller first closes the intake channel valve and opens the exhaust channel valve, connecting the air-cooling channel to the vacuum system in the airflow controller, so that the air-cooling channel is in a negative pressure state. Then, the exhaust channel valve is closed and the intake channel valve is opened. The cooling medium is injected into the air-cooling channel through the intake channel and seeps into the pores of the ceramic shell. The cooling medium exchanges heat with the ceramic shell, reducing the temperature of the ceramic shell.

[0014] Repeat the above steps to adjust the cooling rate of the ceramic shell and reach the target temperature.

[0015] The local high-efficiency cooling device for investment casting shells provided in this application sets a sealed air-cooling channel on the surface of the area of ​​the shell that needs to be cooled. The air-cooling channel allows external gas to flow in and out only through an air inlet and an air outlet. The cooling process is regulated and controlled by a temperature controller and an airflow controller. On the one hand, the heat dissipation method of the ceramic shell can be changed from heat transfer to forced heat convection, which greatly improves the heat dissipation capacity of the shell and expands the local temperature control range of the ceramic shell, which helps to obtain high-quality castings. On the other hand, the gas penetrates into the interior of the ceramic shell and directly exchanges heat with the shell and casting surfaces. Adjusting the cooling gas parameters can quickly adjust the heat transfer coefficient at the shell / casting interface, improving the real-time performance of temperature control.

[0016] Other technical effects resulting from the additional features will be further illustrated in the corresponding embodiments. Attached Figure Description

[0017] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of a localized high-efficiency cooling device for an investment casting shell according to an exemplary embodiment; Figure 2 Temperature-time curves for conventional shell cooling and application example methods; In the diagram: 1 is the housing, 2 is the air cooling channel, 3 is the air inlet, 4 is the exhaust channel, 5 is the airflow controller, 6 is the air source, 7 is the temperature controller, 801 is the air inlet valve, and 802 is the exhaust valve. Detailed Implementation

[0018] The present application will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all fall within the protection scope of the present application. Parts not described in detail in the following embodiments can be implemented using existing technology.

[0019] Existing shell cooling methods generally suffer from low cooling efficiency and lag in cooling regulation. To address these issues, this application provides a localized high-efficiency cooling device for investment casting shells.

[0020] Reference Figure 1 As shown in one embodiment of this application, the local high-efficiency cooling device for investment casting shell includes an air cooling channel 2, an air inlet 3, an exhaust outlet 4, an air source 6, an airflow controller 5, and a temperature controller 7. The air cooling channel 2 is located on the outer surface of the area of ​​the shell 1 that needs cooling. The air cooling channel 2 has an air inlet 3 and an exhaust outlet 4. The airflow controller 5 is connected to both the air inlet 3 and the exhaust outlet 4. The air source 6 provides a cooling gas medium and is connected to the airflow controller 5, which controls the gas cooling parameters. The temperature controller 7 is connected to the airflow controller 5 and controls the airflow controller 5 to alternate between vacuuming and gas filling in the air cooling channel 2 based on the shell temperature and investment casting process parameters, thereby achieving the purpose of cooling the shell 1.

[0021] Specifically, a sealed air-cooling channel 2 is provided on the surface of the shell, specifically the area requiring cooling. The air-cooling channel 2 is fabricated simultaneously during the shell fabrication process and is located on the outer surface of the shell 1. Because it is a sealed structure, therefore... Figure 1As shown, a cavity structure is formed in the area near the surface of the ceramic shell. The sealed air-cooling channel 2 allows external gas to flow in and out only through the air inlet 3 and the exhaust 4. The air inlet 3 and the exhaust 4 are connected to the airflow controller 5, which is connected to the air source 6 and the temperature controller 7. The temperature controller 7 inputs parameters such as air pressure, gas temperature, vacuum function on / off, vacuum degree, gas filling function on / off, and "vacuum-filling" frequency to the airflow controller 5. The airflow controller 5 controls the airflow and adjusts the air pressure according to these instructions. By adjusting the gas cooling parameters, the cooling rate of the shell 1 can be precisely controlled. When the casting has multiple thick-walled areas that need cooling, multiple air-cooling channels 2 are set in the corresponding areas, thus providing local temperature control capabilities.

[0022] For example, the air intake port 3 is located at one end of the air cooling channel 2, and the exhaust port 4 is located at the other end of the air cooling channel 2, that is, the air intake / exhaust port is located at both ends of the air cooling channel 2; or, the air intake port 3 and the exhaust port 4 share a single port, and are connected to the air outlet and air intake devices respectively through a three-way valve outside the housing 1.

[0023] It should be noted that in the investment casting process, the cooling design of the shell 1 needs to be determined based on the structure of the casting. To improve casting quality, the thick-walled areas of the casting require targeted cooling, and the areas of the shell 1 that need cooling generally correspond to the thick-walled areas of the casting. The surface dimensions of the air cooling channel 2 are adapted to the surface dimensions of the areas of the shell 1 that need cooling. Since the cooling rate of the casting also affects the solidification behavior of the surrounding areas, the dimensions of the air cooling channel must also be designed taking into account the characteristics of the surrounding casting.

[0024] Traditional heat dissipation for mold shells involves heat conduction along the thickness direction from the melt to the outer surface of the mold shell, where it is then transferred to the gas. Due to the low thermal conductivity and slow heat transfer rate of ceramic mold shells, the cooling rate is slow, and adjusting the heat dissipation parameters on the outer surface requires a considerable amount of time to transfer to the inner surface, resulting in a slow melt temperature response. The core of this embodiment is that during vacuuming, the exhaust channel is connected to the vacuum system, the inlet channel is closed, and the gas in the porous ceramic mold shell is expelled. During inflation, the exhaust channel is closed, the inlet channel is connected to the gas source 6, and the gas enters the air-cooling channel 2 and permeates into the porous structure of the ceramic mold shell, achieving heat exchange within the shell and avoiding the process of heat transfer from the inside to the outside. By adjusting the inflation pressure, gas medium type, vacuuming-inflation frequency, gas temperature, and vacuum level, not only can the cooling rate of the mold shell 1 be adjusted over a wide range, but the inner surface of the mold shell 1 can also be cooled promptly, resulting in a faster melt temperature adjustment response.

[0025] In the embodiments described above, the alternating vacuuming and gas filling in the air-cooling channel 2 achieves efficient cooling, transforming the heat dissipation method of the ceramic shell from heat transfer to forced heat convection. This significantly improves the heat dissipation capacity of the shell 1 and expands the local temperature control range of the ceramic shell, contributing to the production of high-quality castings. Furthermore, through the air-cooling channel 2, gas penetrates into the ceramic shell and directly exchanges heat with the shell 1 and the casting surface. Adjusting the cooling gas parameters allows for rapid adjustment of the heat transfer coefficient at the shell / casting interface, improving the real-time performance of temperature control. Therefore, the cooling rate and effectiveness of localized areas of the ceramic shell in investment casting can be improved.

[0026] In order to accurately deliver the cooling medium to the cooling area of ​​the shell 1, in some specific embodiments of this application, an air intake channel is provided between the airflow controller 5 and the air intake port 3, and an air intake channel valve 801 is provided on the air intake channel; an exhaust channel is provided between the airflow controller 5 and the exhaust port 4, and an exhaust channel valve 802 is provided on the exhaust channel.

[0027] Specifically, the gas flows into and out of the air-cooling channel 2 in the shell 1 through the air intake channel and the exhaust channel. The air intake channel and the exhaust channel can be made of stainless steel pipe, ceramic pipe, etc., to achieve gas flow at the casting temperature.

[0028] To achieve shell cooling, in some specific embodiments of this application, the gas source 6 provides different types of gas media, such as air or water vapor.

[0029] It should be noted that in some other embodiments, the cooling gas medium can also be other gas media with cooling effects, so as to flexibly meet the cooling needs of different castings.

[0030] In some specific embodiments of this application, the gas cooling parameters include at least one of the following: gas vacuum in the gas cooling channel, gas pressure at the inlet of the gas channel, gas temperature, gas flow rate, gas flow interruption, and the duration and frequency of gas flow interruption. The temperature controller 7 inputs the gas cooling parameters to the airflow controller 5, and the airflow controller 5 achieves precise control of the above parameters.

[0031] Specifically, during operation, the airflow controller 5 first closes the inlet valve 801 and opens the exhaust valve 802, connecting the air-cooling channel 2 to the vacuum system in the airflow controller 5, thus placing the air-cooling channel 2 under negative pressure. Because the ceramic shell has a porous structure, the gas in the pores is carried out and leaves the ceramic shell. Then, the exhaust valve 802 is closed, and the inlet valve 801 is opened, injecting low-temperature gas into the air-cooling channel 2 through the inlet channel. This gas then permeates into the pores of the ceramic shell, where heat exchange occurs, lowering the shell's temperature. This process is repeated, continuously removing the high-temperature gas heated by the ceramic shell and introducing new low-temperature gas. The frequency of this repetition is called the airflow interruption frequency.

[0032] This method changes the heat transfer mode in the ceramic shell from heat conduction to forced heat convection, which can significantly improve the heat dissipation capacity of the shell 1 and achieve the purpose of rapidly reducing the temperature of the ceramic shell and casting in this area.

[0033] Compared to existing technologies (such as CN118492337A and CN118527634A), the embodiments of this application can be used for the production of polycrystalline high-temperature alloy castings. They do not limit the method of ceramic mold shell fabrication. In these embodiments, cooling gas is actively infiltrated into the porous structure inside the mold shell, achieving heat exchange within the ceramic mold shell. Then, a vacuum is evacuated from the air-cooling channels to remove the heat. This "vacuum-gas filling" method changes the heat transfer mode of the ceramic mold shell to a convective heat transfer mode, resulting in a higher cooling rate and a more timely temperature response. The embodiments of this application can be configured with air-cooling channels according to the size of the heat nodes. By setting air-cooling channels in localized areas of the mold shell, cooling is only applied to the area affected by these channels, achieving localized cooling of the mold shell and providing good localized temperature control.

[0034] Another embodiment of this application provides a method for localized high-efficiency cooling of investment casting shells, including: Step S1: Provide the above-mentioned localized high-efficiency cooling device for investment casting shell; Step S2: Set the investment casting process parameters; Step S3: According to the process parameters, place the mold shell in the baking furnace, slowly heat it to the target temperature and keep it at that temperature; Step S4: According to the process parameters, the temperature controller sends a shell cooling command to the airflow controller. The airflow controller draws cooling medium from the air source and introduces it into the air cooling channel to cool the shell. When the shell temperature in the thick-walled area drops to the preset temperature, the gas cooling parameters are adjusted to keep the shell in that area at the preset temperature. Step S5: Pour the molten alloy into the mold shell according to the casting process; Step S6: During the solidification process, adjust the gas cooling parameters according to the process parameters to control the cooling rate of the shell in the thick-walled area of ​​the casting, and obtain the target casting.

[0035] In some specific embodiments of this application, the airflow controller draws cooling medium from the air source and introduces it into the air-cooling channel to cool the housing, specifically including: S41. According to the process parameters, the airflow controller first closes the inlet channel valve and opens the exhaust channel valve, connects the air cooling channel to the vacuum system in the airflow controller, so that the ceramic shell air cooling channel is connected to the vacuum system through the exhaust port, and evacuates the air cooling channel so that the air cooling channel is in a negative pressure state. At this time, the gas in the porous structure of the ceramic shell is discharged. S42. According to the process parameters, the temperature controller sends a shell cooling command to the airflow controller. Then, the airflow controller closes the exhaust channel valve and opens the intake channel valve. The cooling medium is injected into the air cooling channel through the intake channel, so that the ceramic shell air cooling channel is connected to the air source through the intake channel. The cooling medium in the air source enters the air cooling channel and seeps into the pores in the ceramic shell. The cooling medium and the ceramic shell exchange heat to reduce the temperature of the ceramic shell in order to cool the shell.

[0036] Repeat the above steps to continuously adjust the temperature of the shell in this area, adjust the cooling rate of the ceramic shell, and reach the target temperature.

[0037] It should be noted that step S6 also includes repeating steps S41 and S42 to control the cooling rate of the shell in the thick-walled area of ​​the casting.

[0038] In investment casting, high-performance investment castings can be obtained through coordinated control of process parameters. In some specific embodiments of this application, the aforementioned process parameters include the high-temperature alloy melt pouring temperature, the overall shell firing temperature, the shell temperature in the thick-walled region, the cooling rate of the shell in the thick-walled region during solidification, the temperature of the cooling gas medium, the charging pressure, the vacuum-charging frequency, and the vacuum degree.

[0039] The preferred features in the above embodiments can be used individually in any embodiment, or in any combination thereof, provided they do not conflict with each other. Furthermore, parts not described in detail in the embodiments can be implemented using existing technologies.

[0040] The following examples and comparative examples will be used to further illustrate this application in order to better understand the above-mentioned technical solutions. It should be understood that the following are only some examples and are not intended to limit this application.

[0041] Application example: A large, complex high-temperature alloy casting was prepared using investment casting. The thick-walled region required enhanced heat dissipation and rapid cooling. This region of the casting has a wall thickness of 20 mm and an area of ​​[area missing]. The specific steps are as follows: Parameter settings: Simulation calculations show that during casting, the pouring temperature of the high-temperature alloy melt is 1470℃, the overall firing temperature of the mold shell is 850℃, and the temperature of the mold shell in the thick-walled area is 700℃; during solidification, the cooling rate of the mold shell in the thick-walled area is 40℃ / min to obtain good casting quality.

[0042] Shell preparation: A ceramic shell for the casting is prepared. A sealed gas channel is prepared on the outer surface of the shell in the thick-walled region. The cavity size of the channel is [missing information]. A thermocouple is installed on the lower surface of the channel.

[0043] Device Connection: The air inlet and exhaust outlet are connected to the airflow controller using stainless steel tubing with an inner diameter of 8mm. The airflow controller is connected to the temperature controller and the air source, and the thermocouple is connected to the temperature controller.

[0044] Shell firing: Place the shell in a firing furnace, slowly heat it to 850℃ and keep it at that temperature for 4 hours.

[0045] Shell Temperature Regulation: After the shell temperature reaches 850℃ and is maintained for 2 hours, the local shell temperature is regulated. The temperature controller sends a shell cooling command to the airflow controller. The airflow controller draws water vapor from the air source and introduces water vapor into the shell's air-cooling channel to cool the shell. At the inlet, the water vapor pressure is 80 kPa and the temperature is 600℃. During vacuuming, the exhaust pressure is -70 kPa and the airflow interruption frequency is 10 Hz. When the shell temperature in this area drops to 700℃, the air is regulated to maintain the shell temperature at 700℃. The inlet temperature is then adjusted to 680℃, the inlet water vapor pressure to 20 kPa, the exhaust pressure to -40 kPa during vacuuming, and the airflow interruption frequency to 5 Hz.

[0046] Alloy casting: The molten alloy is poured into the mold according to the casting process specifications.

[0047] Temperature regulation of the mold shell during solidification: After casting, in order to improve the solidification rate of the melt in the thick-walled area of ​​the casting, the water vapor cooling parameters in the thick-walled area of ​​the casting are set as follows: the air pressure at the inlet is 80 kPa and the temperature is 500 ℃. When vacuuming, the air pressure at the exhaust port is -80 kPa and the air flow interruption frequency is 20 Hz.

[0048] Completion: 30 minutes after pouring is complete, turn off the temperature controller to end the local temperature adjustment of the shell. After the shell and casting have cooled, clean the shell and remove the casting according to the normal procedure.

[0049] Comparative example: The above-mentioned large and complex high-temperature alloy castings were prepared using conventional shell cooling methods in the comparative example.

[0050] Figure 2The figure shows the temperature-time curves of conventional shell cooling and the application example method. The furnace cooling curve is the conventional method, and the other two curves are the cooling curves obtained by the local high-efficiency cooling method of investment casting shell using different airflow interruption frequencies. Compared with the conventional furnace cooling method, the method of this application can improve the cooling speed and real-time performance of the shell.

[0051] In the description of the embodiments of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0053] In the description of the embodiments in this application, "multiple" means two or more, unless otherwise explicitly specified. In this application, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0054] The terms "comprising" and "having," and any variations thereof, in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or devices.

[0055] The foregoing has described some specific embodiments of this application. It should be understood that this application is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this application. The above-described preferred features can be used in any combination without conflict.

Claims

1. A local high-efficiency cooling device for a shell of a fused mold casting, characterized by, include: Air cooling channels are located on the outer surface of the area of ​​the shell that needs to be cooled. The air-cooling channel has an air inlet and an exhaust outlet; An airflow controller is connected to the air intake port and the exhaust port, respectively; A gas source is used to provide a cooling gas medium. The gas source is connected to the airflow controller, which is used to control the gas cooling parameters. A temperature controller is connected to the airflow controller. The temperature controller is used to control the airflow controller to alternate between vacuuming and air filling in the air cooling channel according to the temperature of the mold shell and the investment casting process parameters, so as to achieve the purpose of cooling the mold shell.

2. The local high efficient cooling device for shell mold casting according to claim 1, characterized in that, An air intake channel is provided between the airflow controller and the air intake port, and an air intake valve is provided on the air intake channel; an exhaust channel is provided between the airflow controller and the exhaust port, and an exhaust channel valve is provided on the exhaust channel.

3. The locally efficient cooling device for shell mould casting according to claim 1, characterized in that, The gas medium provided by the gas source is air or water vapor.

4. The locally efficient cooling device for shell mould casting according to claim 1, characterized in that, The gas cooling parameters include at least one of the following: gas vacuum in the gas cooling channel, gas pressure at the inlet of the gas channel, gas temperature, gas flow rate, gas flow interruption, and the duration and frequency of gas flow interruption.

5. The locally efficient cooling device for shaped shells for fused mould casting according to claim 1, characterized in that, The surface dimensions of the air-cooling channel are adapted to the surface dimensions of the area of ​​the shell that needs to be cooled.

6. A method of locally efficient cooling of a shell for investment casting, characterized in that, include: Provide a localized high-efficiency cooling device for investment casting shells as described in any one of claims 1-5; Set the investment casting process parameters; According to the process parameters, the shell is placed in a baking furnace, slowly heated to the target temperature and kept warm; According to the process parameters, the temperature controller sends a shell cooling command to the airflow controller. The airflow controller draws cooling medium from the air source and introduces it into the air cooling channel to cool the shell. When the shell temperature in the thick-walled area drops to the preset temperature, the gas cooling parameters are adjusted to keep the shell in that area at the preset temperature. The molten alloy is poured into the mold according to the casting process; During the solidification process, the gas cooling parameters are adjusted according to the process parameters to control the cooling rate of the shell in the thick-walled area of ​​the casting, thereby obtaining the target casting.

7. The locally highly efficient cooling method of a shell for investment casting according to claim 6, wherein The process parameters include: high-temperature alloy melt pouring temperature, overall shell firing temperature, shell temperature in thick-walled areas, cooling rate of shell in thick-walled areas during solidification, cooling gas medium temperature, charging pressure, vacuuming-charging frequency, and vacuum degree.

8. The locally highly efficient cooling method of a shell for investment casting according to claim 6, wherein The airflow controller draws cooling medium from the air source and introduces it into the air-cooling channel to cool the housing, including: The airflow controller first closes the intake channel valve and opens the exhaust channel valve, connecting the air-cooling channel to the vacuum system in the airflow controller, so that the air-cooling channel is in a negative pressure state. Then, the exhaust channel valve is closed and the intake channel valve is opened. The cooling medium is injected into the air-cooling channel through the intake channel and seeps into the pores of the ceramic shell. The cooling medium exchanges heat with the ceramic shell to reduce the temperature of the ceramic shell. Repeat the above steps to adjust the cooling rate of the ceramic shell and reach the target temperature.

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