A method for supporting a sand core of a small-remainder pipe micro-hole outlet of a casting

Abstract

The application provides a small-amount-of-sand core support method for a cast small-amount-of-pipe micro-hole outlet, which comprises the following steps: selecting a corresponding copper pipe; wiping the outer surface of the copper pipe with alcohol, heating and keeping warm in a drying furnace; manufacturing a sand core of the cast micro-hole pipe; pretreating the sand core; checking the internal aperture of the sand core; fixing the copper pipe; coating a binder on the outer part of the copper pipe and the matching position of the sand core, connecting the matching position of the copper pipe with the sand core and a core head respectively, ensuring that the outlet of the copper pipe is flush with the bottom plane of the core head, and checking that the copper pipe exposed outside the sand core is free of the binder; surface treatment of the sand core; solidification and shaping; the sand core manufactured by a core shooting machine or a manual core box needs to be solidified and shaped on a special core supporting plate, the core head is a 3D printed sand core with an auxiliary fixing reinforcing rib, and the reinforcing rib is removed after solidification and shaping; ventilation checking; and temperature recovery treatment. The application solves the problem that the cast pipe micro-hole outlet in a cast cannot be accurately positioned in the casting process.

Description

Technical Field

[0001] This application belongs to the technical field of complex pipeline casting manufacturing process, and in particular relates to a method for supporting the micro-hole outlet sand core of a pipeline with small allowance in casting. Background Technology

[0002] With the continuous development of aviation technology, the structure of casing castings for aero engines and their transmission systems is becoming increasingly complex and integrated. Large and complex castings integrate multiple structures and multiple complex spatial orientations of pipelines, which puts forward new requirements for the positioning of integrated microporous pipeline sand cores. The preparation methods of sand cores can no longer fully meet the needs.

[0003] Currently, the size of the sand core positioning section of microporous pipelines is generally not less than 6mm, while the outlet size of most integrated casting pipelines is 5-8mm after machining. This results in insufficient machining allowance at the outlet of microporous pipelines, making it difficult to meet the production needs of integrated microporous pipeline outlet castings.

[0004] Therefore, it is urgent to advance the research on the application of microporous pipe outlet sand core support and positioning, select microporous pipe core support and positioning materials with accurate positioning, small positioning section size and good processability, break through the core technology of integrated microporous pipe casting manufacturing, and lay the foundation for the development of aero-engines and their transmission systems. Summary of the Invention

[0005] The purpose of this invention is to provide a method for supporting the sand core at the outlet of micro-holes in castings with small allowance, thereby solving the problem of inaccurate positioning of the sand core at the outlet of micro-holes in castings during the casting process.

[0006] This application provides a method for supporting the micro-hole outlet sand core of a small-mass casting pipeline, the method comprising: Obtain the required micro-orifice outlet size of the casting, and select the corresponding copper tube based on the micro-orifice outlet size of the casting; Wipe the outer surface of the copper tube with alcohol to ensure there is no oil stains on the outer surface of the copper tube, and heat and keep it warm in the drying oven; Sand cores for manufacturing microporous tubing in castings; pretreatment of the sand cores; and unobstructed inspection of the internal pore diameters of the sand cores. Fixing the copper tube: Apply adhesive to the part of the copper tube that mates with the sand core, ensuring that no adhesive enters the inside of the copper tube. Connect the copper tube to the sand core and the core head respectively. The part connected to the core head must ensure that the copper tube outlet is flush with the bottom plane of the core head. Check that there is no adhesive on the exposed copper tube outside the sand core. Core surface treatment; Curing and shaping: To ensure the accuracy of sand core positioning, sand cores manufactured by core shooting machines or hand-made core boxes need to be cured and shaped on a special core support plate. For 3D printed sand cores with auxiliary fixing ribs at the core head, the reinforcing ribs are removed after curing and shaping. Ventilation check: Use 0.2-0.3MPa dry compressed air to check the ventilation of the sand core and ensure smooth ventilation inside the sand core and at the copper tube connection points; Reheating treatment: Sand cores that pass the ventilation inspection need to be thoroughly dried in a drying oven, heated and kept warm.

[0007] Preferably, the step of wiping the outer surface of the copper tube with alcohol to ensure that the outer surface of the copper tube is free of oil stains, and heating and keeping it warm in a drying oven includes: Wipe the outer surface of the copper tube with alcohol to ensure that there is no oil stains on the outer surface of the copper tube, heat it in the drying oven to 200±10℃, and keep it at that temperature for 30±5 minutes.

[0008] Preferably, after obtaining the required micro-orifice outlet size of the casting and selecting the corresponding copper tube based on the micro-orifice outlet size, the method further includes: Cutting copper pipes: Use a saw blade to cut copper pipes and grind the cut edges to ensure there are no burrs.

[0009] Preferably, the sand core for manufacturing the microporous tubing of the casting comprises: The sand core is manufactured using 3D molding, and the aperture of the part that mates with the copper tube is directly manufactured. However, when manufacturing the sand core, it is necessary to add reinforcing ribs to the core head section for auxiliary fixation.

[0010] Preferably, the pretreatment of the sand core includes: If a sand core is made using a core shooter or a hand-made core box, the sand core needs to be drilled according to the micro-pore size of the casting pipeline. The size of the drilled hole should be consistent with the outer diameter of the copper pipe to be placed at that location. If 3D molding is used to manufacture sand cores, the manufactured internal pores need to be cleaned of sand.

[0011] Preferably, the inspection of the internal pore size of the sand core includes: Use 0.2-0.3MPa dry compressed air to check the inside of the sand core for any loose sand that may be flowing inside.

[0012] Preferably, the surface treatment of the sand core includes: Repair the surface of the sand core to ensure a smooth transition at the copper tube connection.

[0013] Preferably, the sand cores that pass the ventilation inspection need to be thoroughly dried in a drying oven, heated and kept at a certain temperature, including: Sand cores that pass the ventilation inspection must be thoroughly dried in a drying oven at a temperature of 200±10℃ for 90±5 minutes.

[0014] The beneficial technical effects of this application are as follows: This invention provides a method for supporting the sand core of a micro-hole outlet in a casting with small allowance. A hollow copper tube is used as the positioning section for the sand core of the micro-hole pipeline. Utilizing the sand core positioning method of this invention and through reasonable process parameter control, the manufacturing of an integrated micro-hole pipeline casting is achieved. This solves the problem of inaccurate sand core positioning during the casting process of the micro-hole outlet of the cast pipeline. Ultimately, the dimensional accuracy and metallurgical quality of the integrated casting micro-hole pipeline meet the drawing acceptance requirements. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a micro-hole outlet sand core support for a small-margin pipeline in a casting, provided in an embodiment of this application. Among them, 1-sand core, 2-copper tube, 3-core head. Detailed Implementation

[0016] Please see Figure 1 This invention provides a method for supporting the micro-hole outlet sand core of a small-mass casting pipeline, comprising the following steps: The design of the internal casting piping spatial structure determines the dimensions of the casting piping and the design of the casting drawings; Based on the shape and size of the casting, determine the structure, size, and positioning method of the casting pipeline sand core, and determine the forming method of the casting pipeline sand core; Select the corresponding copper tube to obtain the required micro-orifice outlet size of the casting; The sand core is used to manufacture the microporous pipeline of the casting. Then, the sand core is drilled according to the microporous size of the casting pipeline. The size of the drilled hole is consistent with the outer diameter of the copper pipe to be placed at that location. An adhesive is applied to the outside of the copper tube, which is then placed inside the sand core for positioning. The tube is then cured with the aid of an auxiliary device to ensure positioning accuracy. Perform a ventilation check on the sand core to ensure smooth ventilation inside the sand core; The area where the adhesive is applied should be smaller than the contact area between the copper tube and the sand core to avoid clogging of the copper tube outlet during fixing.

[0017] Perform a ventilation check on the microporous oil circuit core of the casting to ensure smooth ventilation and no leaks. If the microporous oil circuit core is intact, firmly bonded, and accurately positioned, then the microporous oil circuit sand core is confirmed.

[0018] This invention provides a method for supporting the sand core of a micro-hole outlet in a casting with small allowance. The invention uses a hollow copper tube as the positioning section for the micro-hole pipe sand core. Utilizing the sand core positioning method of this invention and through reasonable process parameter control, the manufacturing of integrated micro-hole pipe castings is achieved, solving the problem of inaccurate sand core positioning during the casting process of micro-hole outlets in cast pipes. Ultimately, the dimensional accuracy and metallurgical quality of the integrated casting micro-hole pipe meet the drawing acceptance requirements.

[0019] In other embodiments of this application, a certain accessory casing casting is made of ZL114A material. The design requires a Class I casting with a micro-perforated pipe diameter of 5mm and a micro-perforated pipe outlet diameter of 3mm (6mm after machining). The casting pipe is inspected by scribing, borescope, and X-ray. The appearance and internal quality are qualified. After heat treatment, the mechanical properties and chemical composition meet the design acceptance requirements.

[0020] The specific implementation method is as follows: (1) Casting drawing design: Based on the structural characteristics of the part drawing, the allowance for the micropores of the pipeline in the casting drawing shall not be less than 1.5mm.

[0021] (2) Casting pouring scheme design: determine the pouring method and design sand mold and sand core.

[0022] (3) Sand core manufacturing method: Based on the shape and size of the casting, determine the structure, size and positioning method of the casting pipeline sand core, and determine the forming method of the casting pipeline sand core.

[0023] (4) Copper tube specifications: Obtain the required micro-hole outlet size of the casting, select the corresponding copper tube, generally ensure that the oil circuit outlet margin is not less than 1.5mm, the outer diameter of the copper tube is not less than Φ1mm, and the length is determined according to the oil circuit core machining depth (L), which is generally 2mm greater than the oil circuit machining depth (L).

[0024] (5) Cutting copper pipe: Use a saw blade to cut copper pipe and grind the cut to ensure no burrs; do not use pliers or other tools that may cause the copper pipe to deform, resulting in blockage or poor ventilation.

[0025] (6) Copper tube pretreatment: Wipe the outer surface of the copper tube with alcohol to ensure that there is no oil stains on the outer surface of the copper tube, and then heat it in the drying oven at (200±10)℃ and keep it at (30±5)min.

[0026] (7) Sand core manufacturing: Sand cores for manufacturing micro-porous pipes of castings. If the sand core is manufactured by 3D molding, the hole diameter of the part that matches the copper pipe can be directly manufactured. However, when manufacturing the sand core, it is necessary to add auxiliary fixing reinforcing ribs at the core head section.

[0027] (8) Sand core pretreatment: For sand cores manufactured by core shooting machine or manual core box, the sand cores need to be drilled according to the micro-hole size of the casting pipeline. The size of the drilled hole is consistent with the outer diameter of the copper pipe to be placed there. If the sand core is manufactured by 3D molding, the internal hole diameter that has been manufactured needs to be cleaned.

[0028] (9) Check the smoothness of the internal pores of the sand core: Use dry compressed air of (0.2-0.3) MPa to check the smoothness of the inside of the sand core to ensure that there is no loose sand or other foreign matter inside the sand core.

[0029] (10) Fixing the copper tube: Apply adhesive to the part of the copper tube that mates with the sand core, ensuring that no adhesive enters the inside of the copper tube. Connect the copper tube to the sand core and the core head respectively. The part connected to the core head must ensure that the copper tube outlet is flush with the bottom plane of the core head. Check that there is no adhesive on the copper tube exposed outside the sand core.

[0030] (11) Surface treatment of sand core: Repair the surface of sand core to ensure a smooth transition at the copper tube connection.

[0031] (12) Curing and shaping: In order to ensure the accuracy of sand core positioning, sand cores manufactured by core shooting machine or manual core box need to be cured and shaped on a special core support plate. For 3D printed sand cores with auxiliary fixing reinforcing ribs at the core head, the reinforcing ribs are removed after curing and shaping.

[0032] (13) Ventilation check: Use dry compressed air of (0.2-0.3) MPa to check the ventilation of the sand core to ensure smooth ventilation inside the sand core and the copper tube connection.

[0033] (14) Reheating treatment: Sand cores that pass the ventilation inspection need to be thoroughly dried in a drying oven at a heating temperature of (200±10)℃ and a holding time of (90±5)min.

[0034] (15) Core assembly: Assemble the sand mold and sand core as required.

[0035] (16) Casting: Melting alloy and casting.

[0036] (17) Sand removal: The sand mold and core are removed by vibration and sand removal. If necessary, the sand can be removed by burning.

[0037] (18) Marking: Mark the casting number, batch number and sequence number, etc.

[0038] (19) Removal of gating and riser: The gating and riser of the casting are removed by machining.

[0039] (20) Cleaning and polishing: Use sandblasting to remove oxide scale from the surface of the casting, and use flexible tools or tumbling to smooth and remove excess material inside the casting pipe.

[0040] (21) Removal of copper pipes: Remove copper pipes by mechanical or chemical corrosion.

[0041] (22) Visual inspection: Use visual inspection or a borescope to check the surface quality of castings and the internal surface of pipelines, as well as any foreign matter.

[0042] (23) Internal quality inspection: Fluorescent penetrant and X-ray inspection are used to detect the internal quality of the castings.

[0043] (24) Heat treatment: heat treatment of castings.

[0044] (25) Performance testing: Testing tensile strength, elongation and hardness, etc.

[0045] (26) Chemical composition: Chemical composition testing of castings (27) Final inspection: 100% inspection of casting dimensions. The geometry and dimensions of the casting meet the requirements of the casting drawings.

[0046] 100% of the castings are inspected to ensure they meet surface quality standards, and the forgings are free from defects such as cold shuts, cracks, and excessive holes.

[0047] Surface defects may be removed by grinding or machining, but the casting must retain at least one-third of the nominal allowance, and the removal of defects must be smooth and seamless.

[0048] 100% fluorescent penetrant and X-ray inspection of the casting's internal quality revealed no defects exceeding the standard.

[0049] The material grade was checked 100% chemically and found to be correct.

[0050] 100% check the markings; the markings are clear.

[0051] 100% inspection of the mechanical properties of castings.

[0052] In other embodiments of this application, a method for supporting the micro-hole outlet sand core of a small-mass casting pipeline is provided, comprising the following steps: The design of the internal casting piping spatial structure determines the dimensions of the casting piping and the design of the casting drawings; Based on the shape and size of the casting, determine the structure, size, and positioning method of the casting pipeline sand core, and determine the forming method of the casting pipeline sand core; Obtain the required micro-hole outlet size of the casting, select the corresponding copper tube, generally ensure that the oil circuit outlet margin is not less than 1.5mm, the outer diameter of the copper tube is not less than Φ1mm, and the length is determined according to the oil circuit core machining depth (L), which generally needs to be greater than the oil circuit machining depth (L) by 2mm.

[0053] Use a saw blade to cut the copper pipe and grind the cut to ensure there are no burrs; do not use calipers or other tools that may deform the copper pipe, causing blockage or poor ventilation.

[0054] Wipe the outer surface of the copper tube with alcohol to ensure that there is no oil stains on the outer surface of the copper tube, and then heat it in the drying oven at (200±10)℃ and keep it at that temperature for (30±5)min.

[0055] When manufacturing sand cores for microporous pipes in castings, if the sand core is manufactured using 3D molding, the aperture of the part that mates with the copper pipe can be directly manufactured. However, it is necessary to add reinforcing ribs to the core head section for auxiliary fixation during the manufacturing of the sand core.

[0056] For sand cores manufactured using a core shooter or by hand, holes need to be drilled according to the micro-pore size of the casting pipeline. The size of the drilled hole should be consistent with the outer diameter of the copper pipe to be placed there. If sand cores are manufactured using 3D molding, the internal pores that have been manufactured need to be cleaned of sand.

[0057] Use dry compressed air at (0.2-0.3) MPa to check the inside of the sand core for any loose sand or other foreign matter.

[0058] Apply adhesive to the area where the copper tube meets the sand core, ensuring that no adhesive enters the interior of the copper tube. Connect the copper tube to the sand core and the core head at the respective mating points. Ensure that the copper tube outlet is flush with the bottom plane of the core head at the connection point with the core head, and check that there is no adhesive on the exposed copper tube outside the sand core.

[0059] Repair the surface of the sand core to ensure a smooth transition at the copper tube connection.

[0060] To ensure the accuracy of sand core positioning, sand cores manufactured by core shooting machines or hand-made core boxes need to be cured and shaped on a special core support plate. For 3D printed sand cores with auxiliary fixing reinforcing ribs at the core head, the reinforcing ribs are removed after curing and shaping.

[0061] Use dry compressed air at (0.2-0.3) MPa to check the ventilation of the sand core and ensure smooth ventilation inside the sand core and at the copper tube connection points.

[0062] Sand cores that pass the ventilation inspection must be thoroughly dried in a drying oven at a heating temperature of (200±10)℃ and a holding time of (90±5)min.

[0063] Optionally, the sand mold and core can be removed by vibration and sand removal, and if necessary, the sand can be removed by burning.

[0064] Optionally, the casting number, batch number, and sequence number can be printed.

[0065] Optionally, the gating gates and risers of the casting can be removed by machining.

[0066] Optionally, sandblasting can be used to remove oxide scale from the surface of the casting, and flexible tools or tumbling can be used to smooth and remove excess material from inside the casting pipes.

[0067] Optionally, the copper tube can be removed by mechanical or chemical corrosion.

[0068] Optionally, visual inspection or a borescope can be used to check the surface quality of castings and the internal surface of pipes, as well as any foreign matter.

[0069] Optionally, fluorescence penetrant testing and X-ray inspection can be used to detect the internal quality of the casting.

[0070] Optional, heat treatment of the casting.

[0071] Optionally, tensile strength, elongation, and hardness can be tested.

[0072] Optional, chemical composition analysis of castings. Optionally, the method for manufacturing the integrated microporous tubing casting further includes: Final inspection of the cast parts; The final inspection includes: 100% inspection of the outlet dimensions of the microporous tubing in the castings; 100% inspection of the internal surface quality and foreign matter of the microporous tubing in the castings; 100% inspection of the chemical composition of castings; 100% inspection of the mechanical properties of castings; 100% inspection of the fluorescent penetrant and internal X-ray quality of the castings; 100% inspection of markings.

[0073] This invention provides a method for supporting the sand core of a micro-hole outlet in a casting with small allowance. The invention uses a hollow copper tube as the positioning section for the micro-hole pipe sand core. Utilizing the sand core positioning method of this invention and through reasonable process parameter control, the manufacturing of integrated micro-hole pipe castings is achieved, solving the problem of inaccurate sand core positioning during the casting process of micro-hole outlets in cast pipes. Ultimately, the dimensional accuracy and metallurgical quality of the integrated casting micro-hole pipe meet the drawing acceptance requirements.

[0074] The purpose of this invention is to provide a method for supporting the sand core of micro-hole outlets in castings with small allowance pipes, solving the problem of inaccurate positioning of sand cores at the micro-hole outlets of cast pipes during the casting process. Ultimately, this invention achieves precise positioning of the micro-hole pipe core, thereby simultaneously improving the manufacturing reliability of integrated micro-hole pipe castings. The technical solution of this invention is as follows: (1) Casting drawing design: Based on the structural characteristics of the part drawing, the allowance of micropores in the pipeline of the casting drawing shall not exceed 1.5mm.

[0075] (2) Casting pouring scheme design: determine the pouring method and design sand mold and sand core.

[0076] (3) Sand core manufacturing method: Based on the shape and size of the casting, determine the structure, size and positioning method of the casting pipeline sand core, and determine the forming method of the casting pipeline sand core.

[0077] (4) Copper tube specifications: Obtain the required micro-hole outlet size of the casting, select the corresponding copper tube, generally ensure that the oil circuit outlet margin is not less than 1.5mm, the outer diameter of the copper tube is not less than Φ1mm, and the length is determined according to the oil circuit core machining depth (L), which is generally 2mm greater than the oil circuit machining depth (L).

[0078] (5) Cutting copper pipe: Use a saw blade to cut copper pipe and grind the cut to ensure no burrs; do not use pliers or other tools that may cause the copper pipe to deform, resulting in blockage or poor ventilation.

[0079] (6) Copper tube pretreatment: Wipe the outer surface of the copper tube with alcohol to ensure that there is no oil stains on the outer surface of the copper tube, and then heat it in the drying oven at (200±10)℃ and keep it at (30±5)min.

[0080] (7) Sand core manufacturing: Sand cores for manufacturing micro-porous pipes of castings. If the sand core is manufactured by 3D molding, the hole diameter of the part that matches the copper pipe can be directly manufactured. However, when manufacturing the sand core, it is necessary to add auxiliary fixing reinforcing ribs at the core head section.

[0081] (8) Sand core pretreatment: For sand cores manufactured by core shooting machine or manual core box, the sand cores need to be drilled according to the micro-hole size of the casting pipeline. The size of the drilled hole is consistent with the outer diameter of the copper pipe to be placed there. If the sand core is manufactured by 3D molding, the internal hole diameter that has been manufactured needs to be cleaned.

[0082] (9) Check the smoothness of the internal pores of the sand core: Use dry compressed air of (0.2-0.3) MPa to check the smoothness of the inside of the sand core to ensure that there is no loose sand or other foreign matter inside the sand core.

[0083] (10) Fixing the copper tube: Apply adhesive to the part of the copper tube that mates with the sand core, ensuring that no adhesive enters the inside of the copper tube. Connect the copper tube to the sand core and the core head respectively. The part connected to the core head must ensure that the copper tube outlet is flush with the bottom plane of the core head. Check that there is no adhesive on the copper tube exposed outside the sand core.

[0084] (11) Surface treatment of sand core: Repair the surface of sand core to ensure a smooth transition at the copper tube connection.

[0085] (12) Curing and shaping: In order to ensure the accuracy of sand core positioning, sand cores manufactured by core shooting machine or manual core box need to be cured and shaped on a special core support plate. For 3D printed sand cores with auxiliary fixing reinforcing ribs at the core head, the reinforcing ribs are removed after curing and shaping.

[0086] (13) Ventilation check: Use dry compressed air of (0.2-0.3) MPa to check the ventilation of the sand core to ensure smooth ventilation inside the sand core and the copper tube connection.

[0087] (14) Reheating treatment: Sand cores that pass the ventilation inspection need to be thoroughly dried in a drying oven at a heating temperature of (200±10)℃ and a holding time of (90±5)min.

[0088] (15) Core assembly: Assemble the sand mold and sand core as required.

[0089] (16) Casting: Melting alloy and casting.

[0090] (17) Sand removal: The sand mold and core are removed by vibration and sand removal. If necessary, the sand can be removed by burning.

[0091] (18) Marking: Mark the casting number, batch number and sequence number, etc.

[0092] (19) Removal of gating and riser: The gating and riser of the casting are removed by machining.

[0093] (20) Cleaning and polishing: Use sandblasting to remove oxide scale from the surface of the casting, and use flexible tools or tumbling to smooth and remove excess material inside the casting pipe.

[0094] (21) Removal of copper pipes: Remove copper pipes by mechanical or chemical corrosion.

[0095] (22) Visual inspection: Use visual inspection or a borescope to check the surface quality of castings and the internal surface of pipelines, as well as any foreign matter.

[0096] (23) Internal quality inspection: Fluorescent penetrant and X-ray inspection are used to detect the internal quality of the castings.

[0097] (24) Heat treatment: heat treatment of castings.

[0098] (25) Performance testing: Testing tensile strength, elongation and hardness, etc.

[0099] (26) Chemical composition: Chemical composition testing of castings (27) Final Inspection: 100% inspection of casting dimensions. The geometry and dimensions of the castings meet the requirements of the casting drawings. 100% inspection of the surface quality of the castings is required; the surface of the forgings is free of defects such as cold shuts, cracks, and excessive holes. For machined surface defects, grinding or machining is permitted, but at least one-third of the nominal allowance must be retained in the casting, and the removal of defects must be smooth. Fluorescent penetrant and X-ray inspection of the internal quality of the castings are required; no excessive defects are allowed. The markings, chemical composition, and mechanical properties of the castings meet the acceptance requirements of the drawings.

[0100] In other embodiments of this application, the process for precise positioning is provided as follows: Step 1, Copper tube specifications: Obtain the required micro-hole outlet size of the casting, select the corresponding copper tube, generally ensure that the oil circuit outlet margin is not less than 1.5mm, the outer diameter of the copper tube is not less than Φ1mm, and the length is determined according to the oil circuit core machining depth (L), which generally needs to be 2mm greater than the oil circuit machining depth (L).

[0101] Step 2, Cut the copper pipe: Use a saw blade to cut the copper pipe and grind the cut to ensure there are no burrs; do not use pliers or other tools that may deform the copper pipe, causing blockage or poor ventilation.

[0102] Step 3, copper tube pretreatment: Wipe the outer surface of the copper tube with alcohol to ensure that there are no oil stains on the outer surface of the copper tube, and then heat it in the drying oven at (200±10)℃ and keep it at that temperature for (30±5)min.

[0103] Step 4, Sand core manufacturing: To manufacture the sand core for the microporous tubing of the casting, if the sand core is manufactured using 3D molding, the aperture of the part that mates with the copper tube can be manufactured directly. However, it is necessary to add auxiliary fixing reinforcing ribs to the core head section when manufacturing the sand core.

[0104] Step 5, Sand core pretreatment: For sand cores manufactured using a core shooter or manual core box, holes need to be drilled according to the micro-pore size of the casting pipeline. The size of the drilled hole should be consistent with the outer diameter of the copper pipe to be placed there. If the sand core is manufactured using 3D molding, the manufactured internal pores need to be cleaned of sand.

[0105] Step 6, Check the internal pore size of the sand core: Use dry compressed air at (0.2-0.3) MPa to check the internal pore size of the sand core to ensure that there is no loose sand or other foreign matter inside the sand core.

[0106] Step 7, Fix the copper tube: Apply adhesive to the part of the copper tube that mates with the sand core, ensuring that no adhesive enters the inside of the copper tube. Connect the copper tube to the sand core and the core head respectively. The part connected to the core head must ensure that the copper tube outlet is flush with the bottom plane of the core head. Check that there is no adhesive on the exposed copper tube outside the sand core.

[0107] Step 8, core surface treatment: Repair the surface of the core to ensure a smooth transition at the copper tube connection.

[0108] Step 9, Curing and Shaping: To ensure the accuracy of sand core positioning, sand cores manufactured by core shooting machines or hand-made core boxes need to be cured and shaped on a special core support plate. For 3D printed sand cores with auxiliary fixing reinforcing ribs at the core head, the reinforcing ribs are removed after curing and shaping.

[0109] Step 10, Ventilation check: Use dry compressed air at (0.2-0.3) MPa to check the ventilation of the sand core to ensure smooth ventilation inside the sand core and at the copper tube connection points.

[0110] Step 11, Reheating treatment: Sand cores that have passed the ventilation inspection need to be thoroughly dried in a drying oven at a heating temperature of (200±10)℃ and a holding time of (90±5)min.

Claims

1. A method for supporting the micro-hole outlet sand core of a small-mass casting pipeline, characterized in that, The method includes: Obtain the required micro-orifice outlet size of the casting, and select the corresponding copper tube based on the micro-orifice outlet size of the casting; Wipe the outer surface of the copper tube with alcohol to ensure there is no oil stains on the outer surface of the copper tube, and heat and keep it warm in the drying oven; Sand cores for manufacturing microporous tubing for castings; pretreatment of the sand cores; and unobstructed inspection of the internal pore diameters of the sand cores. Fixing the copper tube: Apply adhesive to the part of the copper tube that mates with the sand core, ensuring that no adhesive enters the inside of the copper tube. Connect the copper tube to the sand core and the core head respectively. The part connected to the core head must ensure that the copper tube outlet is flush with the bottom plane of the core head. Check that there is no adhesive on the exposed copper tube outside the sand core. Core surface treatment; Curing and shaping: To ensure the accuracy of sand core positioning, sand cores manufactured by core shooting machines or hand-made core boxes need to be cured and shaped on a special core support plate. For 3D printed sand cores with auxiliary fixing ribs at the core head, the reinforcing ribs are removed after curing and shaping. Ventilation check: Use 0.2-0.3MPa dry compressed air to check the ventilation of the sand core and ensure smooth ventilation inside the sand core and at the copper tube connection points; Reheating treatment: Sand cores that pass the ventilation inspection need to be thoroughly dried in a drying oven, heated and kept at a constant temperature.

2. The method according to claim 1, characterized in that, The process of wiping the outer surface of the copper tube with alcohol to ensure it is free of oil stains, followed by heating and maintaining its temperature in a drying oven, includes: Wipe the outer surface of the copper tube with alcohol to ensure that there is no oil stains on the outer surface of the copper tube, and heat it in the drying oven to 200±10℃ and keep it at that temperature for 30±5 minutes.

3. The method according to claim 1, characterized in that, After obtaining the required micropore outlet size of the casting and selecting the corresponding copper tube based on the micropore outlet size, the process further includes: Cutting copper pipes: Use a saw blade to cut copper pipes and grind the cut edges to ensure there are no burrs.

4. The method according to claim 1, characterized in that, The sand core for manufacturing the microporous tubing of the casting includes: The sand core is manufactured using 3D molding, and the aperture of the part that mates with the copper tube is directly manufactured. However, when manufacturing the sand core, it is necessary to add reinforcing ribs to the core head section for auxiliary fixation.

5. The method according to claim 1, characterized in that, The pretreatment of the sand core includes: If a sand core is made using a core shooter or a hand-made core box, the sand core needs to be drilled according to the micro-pore size of the casting pipeline. The size of the drilled hole should be consistent with the outer diameter of the copper pipe to be placed at that location. If 3D molding is used to manufacture sand cores, the manufactured internal pores need to be cleaned of sand.

6. The method according to claim 1, characterized in that, The inspection of the internal pore size of the sand core includes: Use 0.2-0.3MPa dry compressed air to check the inside of the sand core for any loose sand that may be flowing inside.

7. The method according to claim 1, characterized in that, The surface treatment of the sand core includes: Repair the surface of the sand core to ensure a smooth transition at the copper tube connection.

8. The method according to claim 1, characterized in that, The sand cores that pass the ventilation inspection must be thoroughly dried in a drying oven, heated and kept at a certain temperature, including: Sand cores that pass the ventilation inspection must be thoroughly dried in a drying oven at a temperature of 200±10℃ for 90±5 minutes.

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