Rapid casting method for sand mold containing insert casing

Abstract

The invention discloses a rapid sand mold casting method for a casing containing an insert in the field of casing casting. The rapid sand mold casting method comprises the following steps: step 1, designing and determining three-dimensional models of the casing and the insert; 2, designing a pouring system of the cartridge receiver and carrying out analog simulation; 3, machining and welding the insert according to the designed insert size; 4, designing a 3DP sand mold of the cartridge receiver and printing the sand mold; 5, the printed sand mold is painted with paint, the sand mold is dried, and the insert is put into the sand mold; 6, the sand mold is assembled, and pouring is conducted through a low-pressure pouring technology; and 7, box opening is conducted, the casting is cleaned, and rapid casting of the insert and the casing is completed. The internal quality and the size precision of the cartridge receiver are improved, and the casting quality is improved; the insert in the cartridge receiver is well positioned, and the situation that the whole casting is scrapped due to positioning deviation of the insert is avoided.

Description

Technical Field

[0001] This invention relates to the field of casing casting, and in particular to a rapid sand casting method for casings containing inserts. Background Technology

[0002] The casing is a critical load-bearing structure in the field of aero-engines, bearing the weight, vibration, and complex loads of the engine, directly affecting its performance. Therefore, the internal quality and dimensional accuracy requirements of the casing are high. In existing technology, the casing is made of cast aluminum ZL205A. However, ZL205A is an aluminum-copper alloy, and due to the influence of copper, its casting performance suffers from problems such as high tendency to hot cracking and poor fluidity, making casting difficult. Furthermore, inserts are placed within the casing; misalignment of these inserts in the sand mold can lead to the scrapping of the entire casting.

[0003] Therefore, there is an urgent need to develop a rapid sand casting method for the casing to solve these problems. Summary of the Invention

[0004] The main objective of this invention is to provide a rapid sand casting method for a housing with inserts, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A rapid sand casting method for a housing with inserts. It includes the following steps: Step 1: Design and determine the 3D model of the casing and inserts.

[0006] Step 2: Design the gating system of the casing and perform simulation.

[0007] Step 3: Process and weld the inserts according to the designed insert dimensions.

[0008] Step 4: Design the 3DP sand mold for the casing and print the sand mold.

[0009] Step 5: Apply paint to the printed sand mold, dry the sand mold, and place the insert into the sand mold.

[0010] Step 6: Sand mold assembly, and casting using low-pressure casting process.

[0011] Step 7: Unpack the casting, clean the casting, and complete the rapid casting of the inserts and casing.

[0012] Furthermore, the inserts are L-shaped, with one insert embedded on each of the left and right sides of the casing, and the size of the inserts matches the size of the casing.

[0013] Furthermore, the gating system includes a first gating system, a second gating system, and a third gating system. The first gating system is located at the bottom of the casing, the second gating system is arranged around the middle of the casing, and the third gating system is arranged vertically on both sides of the casing and communicates with the first and second gating systems.

[0014] Furthermore, the first runner has several bottom gates evenly distributed on its upper side, the second runner has several middle gates evenly distributed on its inner side, and the third runner has top gates symmetrically distributed at its end.

[0015] Furthermore, the sand mold includes an upper box, a left middle box, a right middle box, a lower box, a fixed sand core, and a movable sand core. The lower box has interlocking left and right middle boxes above it, and these boxes have cavities. The lower box also has interlocking fixed and movable sand cores located centrally above it.

[0016] Furthermore, an upper positioning groove is provided on the upper part of both the fixed sand core and the movable sand core. The two upper positioning grooves interlock with each other and conform to the shape of the upper end of the insert. A lower positioning groove is provided on the lower part of both the left and right middle boxes. The two lower positioning grooves interlock with each other and conform to the shape of the lower end of the insert.

[0017] Furthermore, the fixed sand core has a protruding upper positioning block on its upper part, the position of which corresponds to the upper positioning groove. The movable sand core has an upper groove on its upper part that mates with the upper positioning block. The left middle box has a protruding lower positioning block on its lower part, the position of which corresponds to the lower positioning groove. The right middle box has a lower groove on its lower part that mates with the lower positioning block.

[0018] Furthermore, the sand mold is equipped with multiple chills, which are located at the top and bottom of the sand mold cavity.

[0019] Furthermore, the casing is made of cast aluminum ZL205A, and the inserts are made of 1Cr18Ni9Ti. The pouring temperature is 680-690℃, the filling pressure is 35-40kPa, the filling speed is 35-45mm / s, the liquid rise pressure is 30-40kPa, the liquid rise speed is 35-45mm / s, and the crystallization time is 600s.

[0020] This invention also includes other components that enable the sand casting method with insert housing to function properly, all of which employ conventional techniques in the art. Furthermore, devices and components not limited in this invention employ conventional techniques in the art. In specific implementation, appropriate equipment or component models can be selected according to the specific working scenario.

[0021] The working principle of this invention is as follows: The casing is cast using an insert casting method, utilizing the high strength and corrosion resistance of the insert material and the lightweight properties of aluminum alloy to optimize the mechanical performance of the casing. The upper and lower ends of the insert are positioned by upper and lower positioning slots, respectively. These upper and lower positioning blocks ensure the accuracy of the sand mold assembly, making the insert firmly and reliably positioned without any positional shift. Simultaneously, the gating system is optimized, and an anti-gravity low-pressure casting process is adopted to facilitate casing forming and feeding, ensuring the quality of the casting.

[0022] Compared with the prior art, the present invention has the following beneficial effects: 1. Improve the internal quality and dimensional accuracy of the casing, enhance the quality of castings, and meet usage requirements.

[0023] 2. Ensure proper positioning of the inserts inside the casing to prevent the entire casting from being scrapped due to misalignment of the inserts.

[0024] 3. Improve casting efficiency, enabling rapid completion of casing casting and reducing production costs. Attached Figure Description

[0025] Figure 1 This is a process flow diagram of an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the casing according to an embodiment of the present invention.

[0027] Figure 3 This is a cross-sectional view of the casing according to an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of the sand mold structure according to an embodiment of the present invention.

[0029] Figure 5 This is an exploded view of the sand mold according to an embodiment of the present invention.

[0030] Figure 6 This is a partial structural diagram of the sand mold according to an embodiment of the present invention.

[0031] Figure 7 This is a schematic diagram of the casting system according to an embodiment of the present invention.

[0032] Figure 8 This is a schematic diagram showing the arrangement of the chills according to an embodiment of the present invention.

[0033] In the diagram: 1. Casing; 2. Insert; 3. Sand mold; 31. Upper box; 32. Left middle box; 33. Right middle box; 34. Lower box; 35. Fixed sand core; 36. Movable sand core; 4. Gating system; 41. First runner; 42. Second runner; 43. Third runner; 44. Bottom gate; 45. Middle gate; 46. Top gate; 5. Chip; 6. Upper positioning groove; 7. Lower positioning groove; 8. Upper positioning block; 9. Lower positioning block. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0035] Example: like Figures 1-8 As shown, a rapid sand casting method for a housing with inserts is described. The method includes the following steps: Step 1: Design and determine the three-dimensional models of casing 1 and insert 2.

[0036] Determine the structural model of casing 1 and the dimensions of insert 2. The dimensions of casing 1 need to be designed to match the dimensions of insert 2.

[0037] Step 2: Design the gating system 4 of casing 1 and perform simulation.

[0038] Given the stringent environmental requirements of casing 1, an anti-gravity low-pressure casting process was chosen. Low-pressure casting achieves stable filling and dense solidification of the alloy liquid through precise pressure control. Simultaneously, it reduces the impact of human factors during casting, resulting in a denser casting structure. A bottom-pouring and slotted gating system 4 was designed to facilitate the forming and feeding of casing 1. After designing the gating system 4, numerical simulation was performed, and the process was adjusted and optimized based on the simulation results.

[0039] Step 3: Process and weld the insert 2 according to the designed dimensions.

[0040] According to the designed shape and size, the different parts of insert 2 are welded together to form the entire insert 2. TIG welding is selected as the welding method, as it effectively avoids metal oxidation, produces clean and aesthetically pleasing welds, and minimizes the heat-affected zone. The welded insert 2 is ensured to be dimensionally correct and meets the drawing requirements after inspection. After welding, insert 2 is cleaned to remove oil, oxides, etc.

[0041] Step 4: Design the 3DP sand mold 3 for casing 1 and print the sand mold 3.

[0042] The shrinkage rate of sand mold 3 is designed to be 1%. Sand mold 3 is manufactured using 3D printing with 100 / 200 mesh natural silica sand as the printing material, and the printed layer thickness is 0.2-0.5 mm. During the printing process, a binder is sprayed point-by-point to bond the powder material, thus creating sand mold 3.

[0043] Step 5: Apply paint to the printed sand mold 3, dry the sand mold 3, and place the insert 2 into the sand mold 3.

[0044] The surface of the 3DP sand mold 3 cavity is coated with paint in two coats to ensure the surface quality of the sand mold 3 and prevent sand adhesion. The first coat is an alcohol-based paint applied by brushing, and then air-dried naturally for about one day. The second coat is a water-based paint applied by dipping. Chills 5 are placed where they are to be placed. After coating and installing the chills 5, the mold is dried in a kiln at 145℃ for 10 hours to remove moisture from the sand mold 3 and chills 5, preventing gas from being introduced into the molten alloy and causing casting defects during pouring. The 3DP sand mold 3 is checked for deformation after drying. After drying, inserts 2 are placed into the sand mold 3 according to the design, and their positions are fixed. A simple measurement is performed to ensure that the inserts 2 are properly positioned.

[0045] Step 6: Sand mold 3-in-1, cast using low-pressure casting process.

[0046] Assemble the 3DP sand mold 3 in sequence, cleaning the cavity of the sand mold 3 thoroughly during assembly. For low-pressure casting, a sand box needs to be fitted over the 3DP sand mold 3 and filled with molding sand to prevent sparking during casting. Specific casting parameters are: casting temperature 680-690℃, filling pressure 35-40kPa, filling speed 35-45mm / s, liquid rise pressure 30-40kPa, liquid rise speed 35-45mm / s, and crystallization time 600s.

[0047] Step 7: Unpack the casting, clean the castings, and complete the rapid casting of the insert 2 and the casing 1.

[0048] Five hours after pouring, the casting was opened and cleaned to obtain the assembled casting.

[0049] Specifically, the material of the casing 1 is cast aluminum ZL205A, and the material of the insert 2 is 1Cr18Ni9Ti. The insert 2 is L-shaped, and one insert 2 is embedded on each of the left and right sides of the casing 1. The size of the insert 2 matches the size of the casing 1.

[0050] The gating system 4 includes a first gating system 41, a second gating system 42, and a third gating system 43. The first gating system 41 is located at the bottom of the casing 1, the second gating system 42 is arranged around the middle of the casing 1, and the third gating system 43 is arranged vertically on both sides of the casing 1 and communicates with the first gating system 41 and the second gating system 42. The first gating system 41 has a plurality of bottom gates 44 evenly distributed on its upper side, the second gating system 42 has a plurality of middle gates 45 evenly distributed on its inner side, and the third gating system 43 has top gates 46 symmetrically distributed at its ends.

[0051] The sand mold 3 includes an upper box 31, a left middle box 32, a right middle box 33, a lower box 34, a fixed sand core 35, and a movable sand core 36. The left middle box 32 and the right middle box 33 are interlocked above the lower box 34, and each of the left middle box 32 and the right middle box 33 has a cavity. The fixed sand core 35 and the movable sand core 36 are interlocked and located centrally above the lower box 34.

[0052] An upper positioning groove 6 is provided on the upper part of the fixed sand core 35 and the upper part of the movable sand core 36. The two upper positioning grooves 6 interlock with each other and are adapted to the shape of the upper end of the insert 2. A lower positioning groove 7 is provided on the lower part of the left middle box 32 and the lower part of the right middle box 33. The two lower positioning grooves 7 interlock with each other and are adapted to the shape of the lower end of the insert 2.

[0053] The fixed sand core 35 has an outwardly protruding upper positioning block 8 on its upper part, and the position of the upper positioning block 8 corresponds to the upper positioning groove 6; the movable sand core 36 has an upper groove on its upper part that cooperates with the upper positioning block 8; the left middle box 32 has an outwardly protruding lower positioning block 9 on its lower part, and the position of the lower positioning block 9 corresponds to the lower positioning groove 7; the right middle box 33 has a lower groove on its lower part that cooperates with the lower positioning block 9.

[0054] In addition, the sand mold 3 is provided with multiple chills 5, which are located at the top and bottom of the cavity of the sand mold 3.

[0055] The working principle of the sand casting method for a housing with inserts according to the present invention is as follows: The housing 1 is cast using an insert casting method. The high strength and corrosion resistance of the insert 2 material, combined with the lightweight characteristics of aluminum alloy, optimize the mechanical properties of the housing 1. The upper and lower ends of the insert 2 are positioned by upper positioning grooves 6 and lower positioning grooves 7, respectively. Upper positioning blocks 8 and lower positioning blocks 9 ensure the accuracy of the sand mold 3 assembly, making the positioning of the insert 2 firm and reliable, preventing positional shifts. Simultaneously, the gating system 4 is optimized, and an anti-gravity low-pressure casting process is adopted to facilitate the forming and feeding of the housing 1, ensuring the quality of the casting.

[0056] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope of the present invention.

Claims

1. A rapid sand casting method for a housing with inserts, characterized in that: Includes the following steps: Step 1: Design and determine the three-dimensional models of the casing (1) and the insert (2); Step 2: Design the gating system (4) of the casing (1) and perform simulation; Step 3: Process and weld the insert (2) according to the designed dimensions; Step 4: Design the 3DP sand mold (3) for the casing (1) and print the sand mold (3); Step 5: Apply paint to the printed sand mold (3), dry the sand mold (3), and put the insert (2) into the sand mold (3); Step 6: Sand mold (3) assembly, and casting using low-pressure casting process; Step 7: Unpack the box, clean the casting, and complete the rapid casting of the insert (2) and the casing (1).

2. The sand casting method for a housing with inserts according to claim 1, characterized in that: The insert (2) is L-shaped, and one insert (2) is embedded on each of the left and right sides of the casing (1). The size of the insert (2) matches the size of the casing (1).

3. The rapid sand casting method for a housing with inserts according to claim 1, characterized in that: The gating system (4) includes a first gating (41), a second gating (42) and a third gating (43); the first gating (41) is located at the bottom of the casing (1), the second gating (42) is arranged around the middle of the casing (1), and the third gating (43) is arranged vertically on both sides of the casing (1) and communicates with the first gating (41) and the second gating (42).

4. The rapid sand casting method for a housing with inserts according to claim 3, characterized in that: The first gating (41) has several bottom gating gates (44) evenly arranged on its upper side, the second gating (42) has several middle gating gates (45) evenly arranged on its inner side, and the third gating (43) has top gating gates (46) symmetrically arranged at its end.

5. The sand casting method for a housing with inserts according to claim 1, characterized in that: The sand mold (3) includes an upper box (31), a left middle box (32), a right middle box (33), a lower box (34), a fixed sand core (35), and a movable sand core (36); the lower box (34) is provided with a left middle box (32) and a right middle box (33) that are interlocked with each other, and the left middle box (32) and the right middle box (33) are provided with cavities; the lower box (34) is provided with a fixed sand core (35) and a movable sand core (36) that are interlocked with each other in the center.

6. The rapid sand casting method for a housing with inserts according to claim 5, characterized in that: The fixed sand core (35) and the movable sand core (36) each have an upper positioning groove (6) on their upper parts. The two upper positioning grooves (6) interlock with each other and are adapted to the shape of the upper end of the insert (2). The left middle box (32) and the right middle box (33) each have a lower positioning groove (7) on their lower parts. The two lower positioning grooves (7) interlock with each other and are adapted to the shape of the lower end of the insert (2).

7. The rapid sand casting method for a housing with inserts according to claim 6, characterized in that: The fixed sand core (35) is provided with an outwardly protruding upper positioning block (8), the position of which corresponds to the upper positioning groove (6); the movable sand core (36) is provided with an upper groove that cooperates with the upper positioning block (8); the left middle box (32) is provided with an outwardly protruding lower positioning block (9), the position of which corresponds to the lower positioning groove (7); the right middle box (33) is provided with a lower groove that cooperates with the lower positioning block (9).

8. The rapid sand casting method for a housing with inserts according to claim 1, characterized in that: The sand mold (3) is provided with a plurality of chills (5), which are located at the top and bottom of the cavity of the sand mold (3).

9. The sand casting method for a housing with inserts according to any one of claims 1-8, characterized in that: The casing (1) is made of cast aluminum ZL205A, and the insert (2) is made of 1Cr18Ni9Ti. The casting temperature is 680-690℃, the filling pressure is 35-40kPa, the filling speed is 35-45mm / s, the liquid lifting pressure is 30-40kPa, the liquid lifting speed is 35-45mm / s, and the crystallization time is 600s.

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