Casting mold and casting method

Abstract

The present invention belongs to the field of casting technology, and discloses a casting mold and a casting method, wherein the casting mold comprises a fixed mold frame and a movable mold frame that can be opened and closed, and a support seat is installed on the left end face of the movable mold frame; the casting mold is used for casting a hemispherical shell; the fixed mold frame is embedded with a fixed mold cavity on the left end face, and the movable mold frame is embedded with a movable mold cavity on the right end face; there is a concave cavity at the center of the left end face of the fixed mold cavity, and a protrusion at the center of the right end face of the movable mold cavity, and the protrusion is surrounded by an annular groove; there is a top column assembly at the center of the protrusion; the top column assembly can move left and right in the movable mold cavity. The present invention has a simple structure and is easy to operate; the structure of the casting mold of the present invention can reduce the generation of pores in the product during the casting process, obtain products that meet the requirements, improve the product qualification rate, and reduce production costs.

Description

Technical Field

[0001] The invention belongs to the technical field of casting, and in particular relates to a casting mold and a casting method. Background Art

[0002] Casting is the process of injecting the prepared casting raw materials into the mold to solidify it and obtain a product similar to the mold cavity. The raw materials for casting can be monomers, slurries that have been initially polymerized or polycondensed, or solutions of polymers and monomers.

[0003] In the process of producing hemispherical shells with high density requirements, products produced using casting molds and casting methods commonly used in the prior art often have air holes, resulting in product density that cannot meet factory requirements and a high scrap rate. Not only is the production efficiency low, but the production cost is also high, and improvement is urgently needed. Summary of the invention

[0004] The purpose of the present invention is to overcome the existing technical problems and provide a casting mold and a casting method.

[0005] To achieve the above object, the present invention is implemented according to the following technical solutions:

[0006] A casting mold, the casting mold comprises a fixed mold frame and a movable mold frame which can be opened and closed, and a support seat installed on the left end surface of the movable mold frame; the casting mold is used for casting a hemispherical shell; the hemispherical shell comprises a hemispherical portion and an annular edge on the lower end surface of the hemispherical portion; the support seat comprises two upper and lower symmetrical legs; an ejector assembly is arranged between the two legs;

[0007] The fixed mold frame is embedded with a fixed mold cavity on the left end surface, and the movable mold frame is embedded with a movable mold cavity on the right end surface; the center of the left end surface of the fixed mold cavity is a concave cavity, the center of the right end surface of the movable mold cavity is a convexity, and the convexity is surrounded by an annular groove; the annular groove matches the annular edge; the concave cavity matches the outer spherical surface of the hemispherical part;

[0008] There is a push column assembly in the center of the protrusion; the push column assembly can move left and right in the dynamic mold cavity; a pressure chamber B is arranged in the fixed mold frame, and a feed channel B connected to the concave cavity is arranged in the pressure chamber B;

[0009] A pressure chamber A is arranged on the right side of the pressure chamber B, and a feed channel A connected to the feed channel B is arranged in the pressure chamber A; a pouring port connected to the feed channel A is arranged on the upper part of the right side of the pressure chamber A, and a punch moving left and right is arranged in the pressure chamber A;

[0010] When the top column assembly moves to the rightmost position, the right end surface of the top column assembly blocks the left end of the feed channel B;

[0011] When the top column assembly moves to the far left, the curved surface formed by the right end face of the top column assembly and the protrusion matches the inner spherical surface of the hemispherical part, and the right end face of the top column assembly, the left end face of the pressure chamber B, the protrusion, the annular groove, and the concave cavity form a cavity that matches the hemispherical shell.

[0012] Preferably, the feed channel A and the feed channel B are coaxial and have the same inner diameter; and the pouring port opens upward.

[0013] Preferably, a plurality of slag bags are arranged around the annular groove; each slag bag is connected to an exhaust groove; and the exhaust groove extends from the right end surface of the movable mold cavity to the right end surface of the movable mold frame.

[0014] Preferably, the top column assembly includes a top column, a spring, and a blocking ring;

[0015] A push column guide sleeve is arranged between the push column and the dynamic model cavity; the push column guide sleeve is fixedly connected to the dynamic model cavity, and the push column moves left and right in the push column guide sleeve; a cylindrical deep groove is arranged at the center of the left end surface of the push column, and a blocking ring is fixed on the left side of the deep groove; the outer diameter of the blocking ring is larger than the inner diameter of the deep groove;

[0016] A placement groove is provided in the movable mold frame on the left side of the ejector column; a spring is placed in the placement groove; and the spring presses the ejector column tightly against the left end of the feed channel B.

[0017] Preferably, the top column guide sleeve is an integrated structure, including a tubular portion on the right and a guide ring on the left; the top column is an integrated structure, including a columnar portion on the right and a guide plate on the left; the guide plate cooperates with the guide ring, and the guide plate can move left and right in the guide ring;

[0018] A rectangular positioning surface A is provided on the guide ring, and a positioning surface B matching with the positioning surface A is provided on the guide disc.

[0019] Preferably, the ejection assembly includes an ejection plate, a push rod A, a push rod B, a guide column A, and a limit guide column;

[0020] A plurality of limit blocks are symmetrically arranged on the opposite end faces of the two legs; the ejector plate is located on the right side of the limit block; the limit guide column and the guide column A are fixedly installed on the left end face of the movable mold frame between the two legs; the tail ends of the limit guide column and the guide column A both penetrate the ejector plate, and the ejector plate can slide left and right along the limit guide column and the guide column A;

[0021] The ejector plate includes a push plate and a push rod fixing plate, and the tails of the push rods A and B are fixed between the push plate and the push rod fixing plate;

[0022] There are multiple push rods A, and the heads of push rods A surround and pass through the bottom of the annular groove and are flush with the bottom of the annular groove; there are multiple push rods B, and each slag bag is passed through by a push rod B, and the heads of push rods B are flush with the bottom of the slag bag.

[0023] Preferably, the ejection assembly further comprises a push rod D and a push rod E; the tails of the push rod D and the push rod E are both fixed between the push plate and the push rod fixing plate;

[0024] There are four push rods D, which are rectangular and pass through the dynamic model cavity. The heads of the push rods D are flush with the right end surface of the dynamic model cavity.

[0025] A plurality of through holes are distributed around the placement groove, the inner diameter of the through hole matches the outer diameter of the push rod E, and the push rod E extends into the through hole.

[0026] Preferably, a plurality of guide columns B are installed on the right end surface of the movable mold frame, and guide holes cooperating with the guide columns B are provided on the left end surface of the fixed mold frame.

[0027] The casting method using the casting mold for casting comprises the following steps:

[0028] S1 Casting mold processing: After the casting mold is assembled and fixed firmly, the casting mold, pressure chamber A and punch are preheated;

[0029] S2 Casting: After preheating, the punch is inserted into the pressure chamber A, the left end face of the punch is located on the right side of the pouring port, and the punch blocks the right end of the feed channel B; then the casting liquid is injected into the feed channel A and the feed channel B through the pouring port;

[0030] The casting process includes the following stages: in the early stage of casting, after the casting liquid is injected, the punch is driven to move to the left until the punch blocks the pouring port; in the middle stage of casting, the punch continues to push the casting liquid until the casting liquid completely fills the feed channel B; in the late stage of casting, the punch continues to move to the left, and under the action of the punch, the ejector assembly moves to the left under the push of the casting liquid to fill the cavity, and the left end face of the punch extends into the feed channel B, and the punch stops moving;

[0031] S3 cooling, after the casting is completed, the casting mold is cooled, and during cooling, the punch is kept pressurized;

[0032] S4 demoulding, after cooling is completed, the ejector assembly is pushed out to demould to obtain a hemispherical shell blank; the hemispherical shell is processed to obtain a hemispherical shell finished product.

[0033] Preferably, the punch moves continuously during the casting process; the moving speed of the punch in the early stage of casting is 0.1-0.3 m / s, the moving speed of the punch in the middle stage of casting is 0.6-0.8 m / s, and the moving speed of the punch in the late stage of casting is 2 m / s.

[0034] The working principle of the present invention is as follows:

[0035] The structure of the casting mold of the present invention enables the top column to block the left end surface of the feed channel B before casting, preventing the casting liquid (molten metal) from directly entering the cavity under the push of the punch to form a cold shut; it also avoids the casting liquid carrying a large amount of air directly into the cavity, reducing the generation of bubbles.

[0036] When the casting liquid is being poured, the surface pressure gradually increases under the push of the punch. When the pressure is greater than the elastic force of the spring on the left side of the ejector column, the ejector column suddenly retreats, allowing the casting liquid to quickly fill the cavity.

[0037] During casting, when the punch moves to fill the feeding channel B with the casting liquid, it is also convenient to discharge the gas in the casting liquid.

[0038] During the cooling process, the punch still maintains the pressurized state and participates in the entire cooling process. The casting liquid is cooled and solidified under the pressure. The obtained product has fewer pores than the traditional process and can achieve the required density. The quality of the obtained product is between the die casting process and the semi-solid extrusion process. The cost of the present invention is lower than that of the die casting process or the semi-solid extrusion process.

[0039] The present invention achieves the following beneficial effects:

[0040] The invention has a simple structure and is easy to operate; the structure of the casting mold of the invention can reduce the generation of pores in the product during the casting process, obtain a product that meets the requirements, improve the product qualification rate, and reduce the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a three-dimensional schematic diagram of Example 1;

[0042] Figure 2 for Figure 1 sectional view of

[0043] Figure 3 for Figure 1 A three-dimensional schematic diagram after removing the fixed mold frame and the pressure chamber A;

[0044] Figure 4 for Figure 2 The right side view of the middle moving mold frame and the moving mold cavity;

[0045] Figure 5 for Figure 3 A three-dimensional schematic diagram after removing the fixed model cavity, the movable model cavity, and the pressure chamber B;

[0046] Figure 6 is a three-dimensional schematic diagram of the sleeve of Example 1;

[0047] Figure 7 is a three-dimensional schematic diagram of the top column of Example 1;

[0048] Figure 8 It is a three-dimensional schematic diagram of the hemispherical shell of the present invention;

[0049] Fig. 9 This is a schematic diagram of the state after the later stage of casting of Example 2 is completed.

[0050] In the figure: 1, fixed mold frame; 2, movable mold frame; 3, hemispherical part; 4, annular edge; 5, support foot; 6, fixed mold cavity; 7, movable mold cavity; 8, concave cavity; 9, protrusion; 10, annular groove; 11, feed channel B; 12, slag bag; 13, exhaust groove; 14, pressure chamber B; 15, feed channel A; 16, tubular part; 17, top column; 18, spring; 19, blocking ring; 20, top column guide sleeve; 21, deep groove; 22, placement Groove; 23. Guide ring; 24. Guide plate; 25. Positioning surface A; 26. Positioning surface B; 27. Push plate; 28. Push rod A; 29. ​​Push rod B; 30. Columnar portion; 31. Guide column A; 32. Limiting guide column; 33. Limiting block; 34. Push rod D; 35. Push rod E; 36. Through hole; 37. Guide column B; 38. Pressure chamber A; 39. Casting port; 40. Punch; 41. Push rod fixing plate; 42. Casting liquid. DETAILED DESCRIPTION

[0051] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0052] Example 1

[0053] like Figures 1 to 8 As shown, a casting mold, the casting mold comprises a fixed mold frame 1 and a movable mold frame 2 which can be opened and closed, and a support seat is installed on the left end surface of the movable mold frame 2; the casting mold is used for casting a hemispherical shell; the hemispherical shell comprises a hemispherical portion 3, and an annular edge 4 on the lower end surface of the hemispherical portion 3;

[0054] The support base includes two upper and lower symmetrical legs 5; an ejector assembly is arranged between the two legs 5;

[0055] The fixed mold frame 1 has a fixed mold cavity 6 embedded in its left end surface, and the movable mold frame 2 has a movable mold cavity 7 embedded in its right end surface; a concave cavity 8 is provided at the center of the left end surface of the fixed mold cavity 6, and a protrusion 9 is provided at the center of the right end surface of the movable mold cavity 7, and an annular groove 10 is provided around the protrusion 9; the annular groove 10 matches the annular edge 4; the concave cavity 8 matches the outer spherical surface of the hemispherical portion 3;

[0056] The center of the protrusion 9 has a push column assembly; the push column assembly can move left and right in the movable mold cavity 7; a pressure chamber B14 is provided in the fixed mold frame 1, and a feed channel B11 connected to the concave cavity is provided in the pressure chamber B14;

[0057] A pressure chamber A38 is provided on the right side of the pressure chamber B14, and a feed channel A15 connected to the feed channel B11 is provided in the pressure chamber A38; a pouring port 39 connected to the feed channel A15 is provided on the upper part of the right side of the pressure chamber A38, and a punch 40 that moves left and right is provided in the pressure chamber A38;

[0058] When the top column assembly moves to the far right, the right end surface of the top column assembly blocks the left end of the feed channel B11;

[0059] When the top column assembly moves to the far left, the curved surface formed by the right end face of the top column assembly and the protrusion 9 matches the inner spherical surface of the hemispherical portion 3, and the right end face of the top column assembly, the left end face of the pressure chamber B, the protrusion 9, the annular groove 10, and the concave cavity 8 form a cavity that matches the hemispherical shell.

[0060] The feed channel A15 and the feed channel B11 are coaxial and have the same inner diameter; the pouring port 39 opens upward.

[0061] A plurality of slag bags 12 are arranged around the annular groove 10 ; each slag bag 12 is connected to an exhaust groove 13 ; the exhaust groove 13 extends from the right end surface of the movable mold cavity 7 to the right end surface of the movable mold frame 2 .

[0062] The top column assembly includes a top column 17, a spring 18, and a blocking ring 19;

[0063] A push column guide sleeve 20 is provided between the push column and the dynamic model cavity; the push column guide sleeve 20 is fixedly connected to the dynamic model cavity 7, and the push column 17 moves left and right in the push column guide sleeve 20; a cylindrical deep groove 21 is provided at the center of the left end surface of the push column 17, and a blocking ring 19 is fixed on the left side of the deep groove 21; the outer diameter of the blocking ring 19 is larger than the inner diameter of the deep groove 21;

[0064] A placement groove 22 is provided in the movable mold frame on the left side of the top column 17; a spring 18 is placed in the placement groove 22; and the spring 18 presses the top column 17 tightly against the left end of the feed channel B11.

[0065] The top column guide sleeve 20 is an integrated structure, including a tubular portion 16 on the right and a guide ring 23 on the left; the top column 17 is an integrated structure, including a columnar portion 30 on the right and a guide plate 24 on the left; the guide plate 24 cooperates with the guide ring 23, and the guide plate 24 can move left and right in the guide ring 23;

[0066] A rectangular positioning surface A25 is provided on the guide ring 23 , and a positioning surface B26 matching with the positioning surface A25 is provided on the guide plate 24 .

[0067] The ejection assembly includes an ejection plate, a push rod A28, a push rod B29, a guide column A31, and a limit guide column 32;

[0068] Two limit blocks 33 are symmetrically arranged on the opposite end surfaces of the two legs 5; the ejector plate is located on the right side of the limit block 33; the limit guide column 32 and the guide column A31 are fixedly installed on the left end surface of the movable mold frame between the two legs 5; the tail ends of the limit guide column 32 and the guide column A31 both penetrate the ejector plate, and the ejector plate can slide left and right along the limit guide column 32 and the guide column A31;

[0069] The ejector plate includes a push plate 27 and a push rod fixing plate 41, and the tails of the push rods A28 and B29 are fixed between the push plate 27 and the push rod fixing plate 41;

[0070] There are six push rods A28, and the heads of the push rods A28 surround and pass through the bottom of the annular groove 10 and are flush with the bottom of the annular groove 10; there are ten push rods B29, and each slag bag 12 is passed through by a push rod B29, and the heads of the push rods B29 are flush with the bottom of the slag bag 12.

[0071] The ejection assembly further includes a push rod D34 and a push rod E35; the tails of the push rod D34 and the push rod E35 are fixed between the push plate 27 and the push rod fixing plate 41;

[0072] There are four push rods D34, which are rectangular and pass through the dynamic model cavity 7. The heads of the push rods D34 are flush with the right end surface of the dynamic model cavity 7.

[0073] Four through holes 36 are distributed around the placement groove 22 . The inner diameter of the through hole 36 matches the outer diameter of the push rod E35 . The push rod E35 extends into the through hole 36 . The projections of the through holes 36 all fall on the guide plate 24 .

[0074] Four rectangularly distributed guide posts B37 are installed on the right end surface of the movable mold frame 2, and guide holes (not shown in the figure) that cooperate with the guide posts B are provided on the left end surface of the fixed mold frame.

[0075] The outer diameter of the left end of the limiting guide column is smaller than the outer diameter of the right end of the limiting guide column. When the ejector plate moves to the rightmost end, it is limited by the limiting guide column.

[0076] Example 2

[0077] The casting method using the casting mold of Example 1 for casting comprises the following steps:

[0078] S1 Casting mold processing: After the casting mold is assembled and fixed firmly, the casting mold, pressure chamber A and punch are preheated;

[0079] S2 Casting: After preheating, the punch is inserted into the pressure chamber A, the left end face of the punch is located on the right side of the pouring port, and the punch blocks the right end of the feed channel B; then the casting liquid is injected into the feed channel A and the feed channel B through the pouring port;

[0080] The casting process includes the following stages: in the early stage of casting, after the casting liquid is injected, the punch is driven to move to the left until the punch blocks the pouring port; in the middle stage of casting, the punch continues to push the casting liquid until the casting liquid completely fills the feed channel B; in the late stage of casting, the punch continues to move to the left, and under the action of the punch, the ejector assembly moves to the left under the push of the casting liquid to fill the cavity, and the left end face of the punch extends into the feed channel B, and the punch stops moving;

[0081] S3 cooling, after the casting is completed, the casting mold is cooled, and during cooling, the punch is kept pressurized;

[0082] S4 demoulding, after cooling is completed, the ejector assembly is pushed out to demould to obtain a hemispherical shell blank; the hemispherical shell is processed to obtain a hemispherical shell finished product.

[0083] In step S2, the punch moves continuously during the casting process; the moving speed of the punch in the early stage of casting is 0.2 m / s, the moving speed of the punch in the middle stage of casting is 0.7 m / s, and the moving speed of the punch in the late stage of casting is 2 m / s.

[0084] like Fig. 9 As shown, it is a schematic diagram of the state after the casting is completed in the later stage of this embodiment. In the actual casting process, the weight of the casting liquid used is greater than the weight of the finished hemispherical shell. While the casting liquid 42 fills the cavity, part of the casting liquid 42 remains in the feed channel B11, and the excess part can be removed by mechanical processing after demolding.

[0085] Example 3

[0086] The steps of Example 3 are the same as those of Example 2, except that in step S2, the punch moves continuously during the casting process; the moving speed of the punch in the early stage of casting is 0.1 m / s, the moving speed of the punch in the middle stage of casting is 0.6 m / s, and the moving speed of the punch in the late stage of casting is 2 m / s.

[0087] Example 4

[0088] The steps of Example 4 are the same as those of Example 2, except that in step S2, the punch moves continuously during the casting process; the moving speed of the punch in the early stage of casting is 0.3 m / s, the moving speed of the punch in the middle stage of casting is 0.8 m / s, and the moving speed of the punch in the late stage of casting is 2 m / s.

[0089] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A casting mold, comprising a fixed mold frame and a movable mold frame that can be opened and closed, and a support seat installed on the left end surface of the movable mold frame; the casting mold is used for casting a hemispherical shell; the hemispherical shell includes a hemispherical portion and an annular edge on the lower end surface of the hemispherical portion; characterized in that: The support base includes two upper and lower symmetrical legs; an ejector assembly is arranged between the two legs; The fixed mold frame is embedded with a fixed mold cavity on the left end surface, and the movable mold frame is embedded with a movable mold cavity on the right end surface; the center of the left end surface of the fixed mold cavity is a concave cavity, the center of the right end surface of the movable mold cavity is a convexity, and the convexity is surrounded by an annular groove; the annular groove matches the annular edge; the concave cavity matches the outer spherical surface of the hemispherical part; There is a push column assembly in the center of the protrusion; the push column assembly can move left and right in the dynamic mold cavity; a pressure chamber B is arranged in the fixed mold frame, and a feed channel B connected to the concave cavity is arranged in the pressure chamber B; A pressure chamber A is arranged on the right side of the pressure chamber B, and a feed channel A connected to the feed channel B is arranged in the pressure chamber A; a pouring port connected to the feed channel A is arranged on the upper part of the right side of the pressure chamber A, and a punch moving left and right is arranged in the pressure chamber A; When the top column assembly moves to the rightmost position, the right end surface of the top column assembly blocks the left end of the feed channel B; When the top column assembly moves to the leftmost position, the curved surface formed by the right end face of the top column assembly and the protrusion matches the inner spherical surface of the hemispherical portion, and the right end face of the top column assembly, the left end face of the pressure chamber B, the protrusion, the annular groove, and the concave cavity form a cavity that matches the hemispherical shell; A plurality of slag bags are arranged around the annular groove; each slag bag is connected to an exhaust groove; the exhaust groove extends from the right end surface of the movable mold cavity to the right end surface of the movable mold frame; The top column assembly includes a top column, a spring, and a blocking ring; A push column guide sleeve is arranged between the push column and the dynamic model cavity; the push column guide sleeve is fixedly connected to the dynamic model cavity, and the push column moves left and right in the push column guide sleeve; a cylindrical deep groove is arranged at the center of the left end surface of the push column, and a blocking ring is fixed on the left side of the deep groove; the outer diameter of the blocking ring is larger than the inner diameter of the deep groove; A placement groove is provided in the movable mold frame on the left side of the ejector column; a spring is placed in the placement groove; and the spring presses the ejector column tightly against the left end of the feed channel B.

2. A casting mold according to claim 1, characterized in that: The feed channel A and the feed channel B are coaxial and have the same inner diameter; the pouring port opens upward.

3. A casting mold according to claim 1, characterized in that: The top column guide sleeve is an integrated structure, including a tubular part on the right and a guide ring on the left; the top column is an integrated structure, including a columnar part on the right and a guide plate on the left; the guide plate cooperates with the guide ring, and the guide plate can move left and right in the guide ring; A rectangular positioning surface A is provided on the guide ring, and a positioning surface B matching with the positioning surface A is provided on the guide disc.

4. A casting mold according to claim 3, characterized in that: The ejection assembly includes an ejection plate, a push rod A, a push rod B, a guide column A, and a limit guide column; A plurality of limit blocks are symmetrically arranged on the opposite end faces of the two legs; the ejector plate is located on the right side of the limit block; the limit guide column and the guide column A are fixedly installed on the left end face of the movable mold frame between the two legs; the tail ends of the limit guide column and the guide column A both penetrate the ejector plate, and the ejector plate can slide left and right along the limit guide column and the guide column A; The ejector plate includes a push plate and a push rod fixing plate, and the tails of the push rods A and B are fixed between the push plate and the push rod fixing plate; There are multiple push rods A, and the heads of push rods A surround and pass through the bottom of the annular groove and are flush with the bottom of the annular groove; there are multiple push rods B, and each slag bag is passed through by a push rod B, and the heads of push rods B are flush with the bottom of the slag bag.

5. A casting mold according to claim 4, characterized in that: The ejection assembly also includes a push rod D and a push rod E; the tails of the push rod D and the push rod E are fixed between the push plate and the push rod fixing plate; there are four push rods D, which pass through the dynamic model cavity in a rectangular shape, and the heads of the push rods D are flush with the right end surface of the dynamic model cavity; A plurality of through holes are distributed around the placement groove, the inner diameter of the through hole matches the outer diameter of the push rod E, and the push rod E extends into the through hole.

6. A casting mold according to claim 5, characterized in that: A plurality of guide columns B are installed on the right end surface of the movable mold frame, and a guide hole matching with the guide columns B is provided on the left end surface of the fixed mold frame.

7. A casting method using the casting mold according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1 Casting mold processing: After the casting mold is assembled and fixed firmly, the casting mold, pressure chamber A and punch are preheated; S2 Casting: After preheating, the punch is inserted into the pressure chamber A, the left end face of the punch is located on the right side of the pouring port, and the punch blocks the right end of the feed channel B; then the casting liquid is injected into the feed channel A and the feed channel B through the pouring port; casting It includes the following stages: in the early stage of casting, after the casting liquid is injected, the punch is driven to move to the left until the punch blocks the pouring port; in the middle stage of casting, the punch continues to push the casting liquid until the casting liquid completely fills the feed channel B; in the late stage of casting, the punch continues to move to the left, and under the action of the punch, the ejector assembly moves to the left under the push of the casting liquid to fill the cavity, the left end face of the punch extends into the feed channel B, and the punch stops moving; S3 cooling, after the casting is completed, the casting mold is cooled, and during cooling, the punch is kept pressurized; S4 demoulding, after cooling is completed, the ejector assembly is pushed out to demould to obtain a hemispherical shell blank; the hemispherical shell is processed to obtain a hemispherical shell finished product.

8. The casting method according to claim 7, characterized in that: The punch moves continuously during the casting process; the moving speed of the punch in the early stage of casting is 0.1-0.3m / s, the moving speed of the punch in the middle stage of casting is 0.6-0.8m / s, and the moving speed of the punch in the late stage of casting is 2m / s.

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