Split type top die structure

Abstract

The invention relates to the technical field of hub casting molds, and discloses a split type top mold structure which comprises a top mold, a negative pressure cavity, a heating ejection assembly and an air exhaust self-compensation assembly. Through an automatic compensation mechanism of mechanical linkage, accurate filling can be achieved according to actual gaps after bubbles overflow, casting closed-loop control is achieved, it is effectively guaranteed that the density of castings is uniform, and the dimensional precision and the internal quality stability of products are guaranteed; distilled water is heated by means of waste heat of molten aluminum to generate steam to push a component to discharge redundant molten aluminum, extra energy is not needed, negative pressure self-circulation is achieved, external air exhaust equipment is not needed, the equipment purchase, operation and maintenance cost is remarkably reduced, and the green manufacturing concept is met. Through cooperative operation of the cooling pipe and the negative pressure cavity based on an ideal gas state equation, stable negative pressure circulation is achieved, it is guaranteed that the negative pressure cavity is in an ideal negative pressure state before casting every time, and the stability of the casting technology is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of hub casting molds, and more specifically, relates to a split top mold structure. Background Art

[0002] In the field of aluminum alloy hub casting, the split mold structure is widely used due to its characteristics of being easy to disassemble, assemble and maintain. The cooperation between the top mold and the bottom mold constitutes a complete casting space.

[0003] However, the existing split top molds still face many technical problems during actual use. Most traditional split top molds simply open exhaust channels to discharge the air in the cavity, but the effect of discharging the bubbles inside the molten aluminum is not good, and it is difficult to effectively avoid casting defects such as porosity and shrinkage porosity, resulting in uneven internal quality of the casting, seriously affecting the mechanical properties and service life of the aluminum alloy hub; and some split top molds rely on external air extraction equipment to achieve negative pressure exhaust, which not only increases the complexity and purchase cost of the equipment, but also requires separate exhaust each time it is used, with complex operations and is not conducive to improving efficiency.

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] To solve the technical problems that most traditional split top molds simply open exhaust channels to discharge the air in the cavity, the effect of discharging the bubbles inside the molten aluminum is not good, and it is difficult to effectively avoid casting defects such as porosity and shrinkage porosity, resulting in uneven internal quality of the casting, seriously affecting the mechanical properties and service life of the aluminum alloy hub; and some split top molds rely on external air extraction equipment to achieve negative pressure exhaust, which not only increases the complexity and purchase cost of the equipment, but also requires separate exhaust each time it is used, with complex operations and is not conducive to improving efficiency, the basic concept of the technical solution adopted by the present invention is as follows: A split top mold structure, including a top mold.

[0006] A negative pressure cavity for adsorbing bubbles and filled with distilled water is opened on the top mold, and a cover plate is covered on the negative pressure cavity; A connecting pipe communicating with the bottom of the top mold is installed on the cover plate, and a temperature-rising ejection assembly is installed on the connecting pipe. The temperature-rising ejection assembly includes a piston inserted into the negative pressure cavity and a flow dividing table inserted into the inner cavity of the connecting pipe; The piston slides after the pressure in the negative pressure cavity increases until it moves to the pressure relief hole communicated with the negative pressure cavity, and drives the flow dividing table to eject the excess molten aluminum in the connecting pipe, and the internal negative pressure state is generated after the steam is cooled when the temperature of the negative pressure cavity returns; An air extraction self-compensation component is installed inside the negative pressure cavity. The air extraction self-compensation component includes a turntable for blocking the negative pressure port inside the negative pressure cavity, and a notch for opening the negative pressure port is provided on the turntable. A guide block for extruding excess aluminum liquid into the mold cavity is installed at the bottom of the turntable, thereby compensating for the holes caused by the overflow of bubbles.

[0007] As a preferred embodiment of the present invention, four positioning grooves are provided at the bottom corners of the top mold. Four positioning rods are installed inside the four positioning grooves, and the positioning rods are in a vertical state. The positioning rods are inserted into the bottom mold adapted to the top mold. An installation hole is provided on the side wall of the top mold, and an installation groove communicating with the bottom mold is provided at the bottom of the installation hole, and the installation groove is used to connect bolts.

[0008] As a preferred embodiment of the present invention, a mold core is provided at the bottom of the top mold. A countersunk head groove is provided on the negative pressure cavity, and the cover plate is installed on the countersunk head groove, and the two have matching sizes. A cooling pipe communicating with the bottom mold is installed inside the top mold, and the cooling pipe penetrates through the inner cavity of the negative pressure cavity.

[0009] As a preferred embodiment of the present invention, a positioning sleeve communicating with the negative pressure cavity is installed on the cover plate. A sliding cavity is provided inside the positioning sleeve, and an installation cavity is communicated with the end of the sliding cavity. A pressure relief hole for pressure relief is provided on the side wall of the sliding cavity, and the bottom of the sliding cavity is movably connected with a piston.

[0010] As a preferred embodiment of the present invention, a sliding rod is installed on the piston. The sliding rod movably penetrates through the positioning sleeve. A limiting plate is installed on the side wall of the sliding rod, and the limiting plate overlaps above the positioning sleeve. A return spring is sleeved on the side wall of the sliding rod. One end of the return spring is clamped on the inner side wall of the installation cavity, and the other end of the return spring is clamped on the upper surface of the piston.

[0011] As a preferred embodiment of the present invention, a connecting plate is installed at the top of the sliding rod. The connecting plate is placed above the connecting pipe, and a guide cover is installed at the bottom of the connecting plate. The guide cover is conical, and the bottom is inserted into the bottom of the connecting pipe. Two vertical rods are connected to the bottom of the guide cover. The two vertical rods are parallel to each other, and the bottom of the vertical rods is connected to the surface of the flow dividing table.

[0012] As a preferred embodiment of the present invention, a conical arc surface is provided at the bottom of the connecting pipe. The surface of the flow dividing table is inclined, and the connecting pipe is adapted to the flow dividing table. An inner groove is provided on the cover plate. The inner groove is annular. A collecting cover is installed on the inner groove through bolts. The collecting cover is sleeved outside the connecting pipe, and the top of the connecting pipe is in the same plane as the top of the collecting cover, and the outer edge of the top of the collecting cover is chamfered.

[0013] As a preferred embodiment of the present invention, a rotating shaft is installed on the turntable. The rotating shaft movably penetrates through the cover plate. A knob is installed at the end of the rotating shaft, and an adapting protrusion is installed on the knob. A torsion spring is sleeved on the rotating shaft. One end of the torsion spring is clamped at the bottom of the cover plate, and the other end is clamped on the turntable.

[0014] As a preferred embodiment of the present invention, a negative pressure pipe is connected to the bottom of the negative pressure chamber. The surface of the turntable is attached to the negative pressure port of the negative pressure pipe, and the notch size is larger than the size of the negative pressure pipe.

[0015] As a preferred embodiment of the present invention, a compensation cover is installed at the bottom of the negative pressure chamber. A push plate slides inside the compensation cover, and a push rod is installed on the push plate. The push rod movably penetrates through the compensation cover. A rolling ball is installed at the end of the push rod, and the rolling ball is slidably connected to the slope formed on the surface of the guiding block.

[0016] The present invention has the following beneficial effects compared with the prior art: Through the automatic compensation mechanism of mechanical linkage, the present invention can accurately fill the actual voids after the bubbles overflow, realizing closed-loop control of casting, effectively ensuring uniform density of the castings, and ensuring stable product dimensional accuracy and internal quality. By using the waste heat of the molten aluminum to heat distilled water to generate steam to push the components to discharge the excess molten aluminum, no additional energy is required. At the same time, negative pressure self-circulation is achieved, and no external air extraction equipment is needed, significantly reducing the equipment purchase, operation, and maintenance costs, which conforms to the concept of green manufacturing. Relying on the coordinated operation of the cooling pipe and the negative pressure chamber based on the ideal gas state equation, stable negative pressure circulation is realized, ensuring that the negative pressure chamber is in an ideal negative pressure state before each casting, and improving the stability of the casting process.

[0017] The following further describes in detail the specific embodiments of the present invention with reference to the accompanying drawings. Description of the Drawings

[0018] In the drawings: Figure 1 It is the bottom view of a split top mold structure; Figure 2 It is the three-dimensional view of a split top mold structure; Figure 3 It is the cross-sectional view of a split top mold structure; Figure 4 For Figure 3 The enlarged view at A in Figure 5 It is the turntable connection structure diagram of a split top mold structure; Figure 6 For Figure 3 The enlarged view at B in Figure 7 For Figure 3 The front view of Figure 8 Schematic diagram of the internal structure of the negative pressure chamber of a split top mold structure.

[0019] In the figure: 1. Top mold; 11. Positioning rod; 111. Positioning groove; 12. Mold core; 13. Mounting hole; 131. Mounting groove; 14. Negative pressure chamber; 141. Countersunk head groove; 15. Cooling pipe; 2. Cover plate; 21. Connecting pipe; 211. Conical arc surface; 212. Collection hood; 213. Inner groove; 22. Positioning sleeve; 221. Slide cavity; 222. Mounting cavity; 223. Pressure relief hole; 23. Piston; 231. Slide rod; 232. Return spring; 233. Limit plate; 24. Diverting table; 241. Upright rod; 242. Guide hood; 244. Connecting plate; 3. Turntable; 31. Rotating shaft; 311. Knob; 312. Torsion spring; 32. Notch; 321. Negative pressure pipe; 33. Guide block; 331. Push rod; 332. Ball; 333. Push plate; 334. Ramp; 335. Compensation hood. Specific embodiments

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments in conjunction with the accompanying drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention.

[0021] Embodiment 1, as Figures 1 to 8 shown, a split top mold structure includes a top mold 1.

[0022] The top mold 1 is provided with a negative pressure cavity 14 for adsorbing bubbles and filled with distilled water inside, and a cover plate 2 is covered on the negative pressure cavity 14; a connecting pipe 21 communicating with the bottom of the top mold 1 is installed on the cover plate 2, and a temperature-rising ejection assembly is installed on the connecting pipe 21. The temperature-rising ejection assembly includes a piston 23 inserted into the negative pressure cavity 14 and a flow dividing table 24 inserted into the inner cavity of the connecting pipe 21; the piston 23 slides after the pressure in the negative pressure cavity 14 rises until it moves to the pressure relief hole 223 communicated with the negative pressure cavity 14, and drives the flow dividing table 24 to eject the excess aluminum liquid in the connecting pipe 21, and after the temperature of the negative pressure cavity 14 returns, the cooling vapor makes the inside of it in a negative pressure state; an air extraction self-compensation assembly is installed inside the negative pressure cavity 14. The air extraction self-compensation assembly includes a turntable 3 for blocking the negative pressure port inside the negative pressure cavity, and a notch 32 for opening the negative pressure port is provided on the turntable 3. A guiding block 33 for extruding the excess aluminum liquid into the mold cavity is installed at the bottom of the turntable 3, thereby compensating for the holes caused by the overflow of bubbles. Compared with the traditional top mold structure, this solution actively adsorbs bubbles through the negative pressure cavity 14, avoiding defects such as casting porosity and looseness caused by bubble residues, and significantly improving the mechanical properties and surface quality of the casting. At the same time, the negative pressure adsorption method does not require additional air extraction equipment and air extraction processes, effectively reducing the equipment investment cost and production cycle, increasing the output per unit time, and enhancing the competitiveness of the enterprise in the market.

[0023] As Figures 1 to 8 shown, in the specific implementation manner, four positioning grooves 111 are opened at the bottom corners of the top mold 1, a positioning rod 11 is installed inside the four positioning grooves 111, and the positioning rod 11 is in a vertical state. The positioning rod 11 is inserted into the bottom mold adapted to the top mold 1. An installation hole 13 is opened on the side wall of the top mold 1, and an installation groove 131 communicating with the bottom mold is opened at the bottom of the installation hole 13, and the installation groove 131 is used for connecting bolts. The cooperative design of the positioning groove 111 and the positioning rod 11 can ensure the rapid and accurate positioning of the top mold 1 and the bottom mold, avoiding problems such as aluminum liquid leakage and casting size deviation caused by installation errors, and improving the assembly efficiency and product qualification rate; and the bolt connection method ensures the firm connection between the top mold and the bottom mold, which can withstand the high temperature and pressure changes during the casting process.

[0024] As Figures 1 to 8As shown in the figure, further, a die core 12 is provided at the bottom of the top die 1. A counterbore 141 is formed on the negative pressure cavity 14. The cover plate 2 is installed on the counterbore 141, and the sizes of the two are adapted to each other. A cooling pipe 15 communicating with the bottom die is installed inside the top die 1, and the cooling pipe 15 penetrates through the inner chamber of the negative pressure cavity 14. The die core 12 can be replaced according to different casting requirements, enhancing the versatility of the top die structure; the fitting installation of the counterbore 141 and the cover plate 2 can effectively prevent the leakage of distilled water and ensure the stability of the function of the negative pressure cavity 14; the cooling pipe 15 penetrates through the negative pressure cavity 14, which can not only quickly cool the molten aluminum and shorten the casting forming time, but also cool the negative pressure cavity to realize the stable operation of the negative pressure self-circulation.

[0025] Embodiment 2, which is different from Embodiment 1 in this embodiment: As Figures 1 to 8 shown in the figure, a positioning sleeve 22 communicating with the negative pressure cavity 14 is installed on the cover plate 2. A sliding cavity 221 is formed inside the positioning sleeve 22, and an installation cavity 222 is communicated with the end of the sliding cavity 221. A pressure relief hole 223 for pressure relief is formed on the side wall of the sliding cavity 221, and the bottom of the sliding cavity 221 is movably connected with a piston 23. The design of the positioning sleeve 22 provides a stable sliding track for the piston 23, ensuring that the piston 23 can move accurately when the pressure changes, and improving the controllability and accuracy of the discharge of excess molten aluminum.

[0026] As Figures 1 to 8 shown in the figure, in the specific implementation manner, a sliding rod 231 is installed on the piston 23. The sliding rod 231 movably penetrates through the positioning sleeve 22. A limiting plate 233 is installed on the side wall of the sliding rod 231. The limiting plate 233 overlaps above the positioning sleeve 22. A return spring 232 is sleeved on the side wall of the sliding rod 231. One end of the return spring 232 is clamped on the inner side wall of the installation cavity 222, and the other end of the return spring 232 is clamped on the upper surface of the piston 23. The limiting plate 233 can prevent the piston 23 from detaching from the positioning sleeve 22, ensuring the integrity and reliability of the device structure; the return spring 232 can automatically push the piston 23 to reset after the pressure in the negative pressure cavity 14 decreases, realizing the automatic cycle of the device, reducing manual intervention, and improving production efficiency and stability.

[0027] As Figures 1 to 8As shown in the figure, further, a connecting plate 244 is installed at the top of the sliding rod 231. The connecting plate 244 is placed above the connecting pipe 21. A guiding cover 242 is installed at the bottom of the connecting plate 244. The guiding cover 242 is conical, and its bottom is inserted into the bottom of the connecting pipe 21. Two vertical rods 241 are connected to the bottom of the guiding cover 242. The two vertical rods 241 are parallel to each other, and the bottoms of the vertical rods 241 are connected to the surface of the flow splitting table 24. A conical arc surface 211 is opened at the bottom of the connecting pipe 21. The surface of the flow splitting table 24 is inclined, and the connecting pipe 21 is adapted to the flow splitting table 24. An inner groove 213 is opened on the cover plate 2. The inner groove 213 is annular. A collecting cover 212 is installed on the inner groove 213 through bolts. The collecting cover 212 is sleeved outside the connecting pipe 21. The top of the connecting pipe 21 and the top of the collecting cover 212 are on the same plane, and the outer edge of the top of the collecting cover 212 is chamfered. The cooperation between the guiding cover 242 and the conical arc surface 211 can effectively guide the excess aluminum liquid to discharge, avoid the splashing of aluminum liquid, and ensure the cleanliness of the working environment and the safety of the operators; the collecting cover 212 can collect the discharged aluminum liquid, which is convenient for recycling and reuse, reduces the waste of raw materials, and conforms to the concept of green production.

[0028] Embodiment 3, which is different from Embodiment 2 in this embodiment: As Figures 1 to 8 shown in the figure, a rotating shaft 31 is installed on the turntable 3. The rotating shaft 31 passes through the cover plate 2 movably. A knob 311 is installed at the end of the rotating shaft 31, and an adapting protrusion is installed on the knob 311. A torsion spring 312 is sleeved on the rotating shaft 31. One end of the torsion spring 312 is clamped at the bottom of the cover plate 2, and the other end is clamped on the turntable 3. The adapting protrusion on the knob 311 is convenient for the operator to apply force to realize the rapid rotation of the turntable 3; while providing the reset power, the torsion spring 312 can also buffer the rotation of the turntable 3, reduce mechanical wear, and extend the service life of the device.

[0029] As Figures 1 to 8 shown in the figure, in the specific implementation, a negative pressure pipe 321 is connected to the bottom of the negative pressure chamber 14. The surface of the turntable 3 is attached to the negative pressure port of the negative pressure pipe 321, and the size of the notch 32 is larger than the size of the negative pressure pipe 321. This design can ensure that when the turntable 3 rotates, the negative pressure port can be completely opened and closed, realizing the precise control of negative pressure adsorption of bubbles and ensuring the reliability of the bubble removal effect.

[0030] As Figures 1 to 8As shown, further, a compensation cover 335 is installed at the bottom of the negative pressure chamber 14. A push plate 333 slides inside the compensation cover 335, and a push rod 331 is installed on the push plate 333. The push rod 331 movably penetrates through the compensation cover 335, and a rolling ball 332 is installed at the end of the push rod 331. The rolling ball 332 is slidably connected to a slope 334 formed on the surface of the guide block 33. The contact mode between the rolling ball 332 and the slope 334 converts sliding friction into rolling friction, effectively reducing the friction force, improving the smoothness and response speed of the compensation process, making the compensation of the molten aluminum more timely and accurate, and further improving the quality of the casting.

[0031] The implementation principle of a split top die structure of the present invention is as follows: First, when using this device, the top die 1 and the bottom die are assembled first. The bottom die is not shown in the figure. When the two are assembled, a hub-shaped cavity is formed. Then, the operator injects molten aluminum into it through the connecting pipe 21, and the negative pressure chamber 14 is in a negative pressure state (the reason why the negative pressure chamber is in a negative pressure state will be described later). The above structure enables the negative pressure to adsorb bubbles immediately after the molten aluminum is injected, avoiding the influence of bubble residues on the quality of the casting. Compared with traditional molds that require an additional air extraction step, the production efficiency is greatly improved.

[0032] When the internal chamber is filled, the molten aluminum will lift the push plate 333 to move to the top of the compensation cover 335, and then fill the entire compensation cover 335, facilitating subsequent compensation operations.

[0033] After the molten aluminum is filled, the operator rotates the knob 311. The knob 311 drives the turntable 3 to rotate through the rotating shaft 31. At this time, the torsion spring 312 on the turntable 3 is synchronously twisted, facilitating the subsequent reset operation through the torsion spring 312.

[0034] During the rotation of the turntable 3, when the notch 32 on the turntable 3 corresponds to the negative pressure pipe 321, the negative pressure inside the negative pressure chamber 14 will adsorb the bubbles in the molten aluminum and move them into the negative pressure chamber 14, thereby achieving the purpose of removing bubbles from the molten aluminum.

[0035] However, after the bubbles in the molten aluminum are removed, the molten aluminum at this time will not be fully filled in the chamber. Therefore, after the turntable 3 rotates, the guide block 33 at the bottom of the turntable 3 rotates accordingly. The slope 334 on the surface of the guide block 33 contacts the rolling ball 332. As the guide block 33 rotates, the slope 334 pushes the rolling ball 332, thereby driving the push rod 331 and the push plate 333 to slide downward in the compensation cover 335. The push plate 333 squeezes the molten aluminum pre-lifted and filled in the compensation cover 335 into the mold cavity to compensate for the holes caused by the overflow of bubbles, ensuring that the molten aluminum is fully filled in the chamber. This mechanical linkage compensation mechanism can automatically fill according to the actual voids after the bubbles are discharged, realizing the closed-loop control of the casting process, ensuring the uniform density of the castings, and improving the product yield.

[0036] Then the operator resets the turntable 3 through the torsion spring 312.

[0037] Then the operator stands still for a period of time. The distilled water in the negative pressure chamber 14 can be heated by the heat of the molten aluminum itself. After the distilled water boils, water vapor can be generated, increasing the internal pressure of the negative pressure chamber 14. The increased pressure pushes the piston 23 to slide in the sliding cavity 221. The piston 23 drives the connecting plate 244, the guide cover 242, and the vertical rod 241 to move synchronously through the sliding rod 231, thereby pushing the shunt table 24 to move upward. When the piston 23 moves to the pressure relief hole 223 connected to the negative pressure chamber 14, it prevents the excessive pressure in the chamber caused by the vaporization of the distilled water from affecting the stability of the device. And the shunt table 24 ejects the excess molten aluminum in the connecting pipe 21, and at the same time discharges the excess molten aluminum to ensure the casting accuracy. Making full use of the waste heat of the molten aluminum without additional energy consumption is both environmentally friendly and cost-reducing; through the linkage structure of the piston-shunt table, the discharge of excess molten aluminum is accurately controlled to ensure that the amount of injected molten aluminum meets the casting requirements and improves the product consistency.

[0038] With the introduction of cold water into the cooling pipe 15, the cooling pipe 15 is a prior art at this time, and its working principle will not be elaborated here. The molten aluminum gradually cools and solidifies. With the intervention of the cooling pipe 15, the temperature of the molten aluminum decreases, and at the same time, the cooling pipe 15 cools the negative pressure chamber 14. At this time, the water vapor in the negative pressure chamber 14 begins to cool and condense into liquid water. According to the ideal gas state equation PV = nRT (where P represents pressure, V represents gas volume, n represents the amount of gas substance, R is the ideal gas constant, and T represents thermodynamic temperature), when the chamber volume V remains unchanged, the amount of gas substance n decreases due to the condensation of water vapor, and the temperature T decreases, the pressure P will decrease significantly, causing a negative pressure state to be generated again inside the negative pressure chamber 14, preparing for adsorbing bubbles in the next casting process (this state explains why the negative pressure chamber 14 is in a negative pressure stage in the initial state). The above structure realizes negative pressure self-circulation without external air extraction equipment, simplifies the equipment structure, and the collaborative design of the cooling pipe and the negative pressure chamber ensures that the negative pressure chamber is in an ideal negative pressure state before each casting, improving the process stability.

[0039] Meanwhile, the return spring 232 deforms when the piston 23 moves under the steam pressure. After the pressure in the negative pressure chamber 14 decreases, the return spring 232 provides a restoring force to push the piston 23 back to its original position, returning the device to its initial state for the next casting cycle.

Claims

1. A split top formwork structure, comprising a top formwork (1), characterized in that: A negative pressure cavity (14) for adsorbing air bubbles and filled with distilled water is formed on the top die (1), and a cover plate (2) is covered on the negative pressure cavity (14); A connecting pipe (21) communicating with the bottom of the top die (1) is installed on the cover plate (2), and a temperature-rising ejection assembly is installed on the connecting pipe (21). The temperature-rising ejection assembly includes a piston (23) inserted into the negative pressure cavity (14) and a flow dividing table (24) inserted into the inner cavity of the connecting pipe (21); The piston (23) slides after the pressure in the negative pressure cavity (14) rises until it moves to a pressure relief hole (223) communicated with the negative pressure cavity (14), and drives the flow dividing table (24) to eject the excess aluminum liquid in the connecting pipe (21). After the temperature of the negative pressure cavity (14) recovers, the cooling vapor makes the inside of the negative pressure cavity (14) in a negative pressure state; An air extraction self-compensation assembly is installed inside the negative pressure cavity (14). The air extraction self-compensation assembly includes a turntable (3) for blocking the negative pressure port inside the negative pressure cavity, and a notch (32) for opening the negative pressure port is formed on the turntable (3). A guiding block (33) for extruding the excess aluminum liquid into the mold cavity is installed at the bottom of the turntable (3), so as to compensate for the holes caused by the overflow of air bubbles.

2. The split top formwork structure according to claim 1, characterized in that, Four positioning grooves (111) are formed at the bottom corners of the top die (1). Four positioning rods (11) are installed inside the four positioning grooves (111), and the positioning rods (11) are in a vertical state. The positioning rods (11) are inserted into the bottom die adapted to the top die (1). An installation hole (13) is formed on the side wall of the top die (1). An installation groove (131) communicated with the bottom die is formed at the bottom of the installation hole (13), and the installation groove (131) is used for connecting bolts.

3. The split top formwork structure according to claim 1, characterized in that, A mold core (12) is arranged at the bottom of the top die (1). A counterbore (141) is formed on the negative pressure cavity (14). The cover plate (2) is installed on the counterbore (141), and the sizes of the two are adapted. A cooling pipe (15) communicated with the bottom die is installed inside the top die (1), and the cooling pipe (15) penetrates through the inner cavity of the negative pressure cavity (14).

4. The split top formwork structure according to claim 1, characterized in that, A positioning sleeve (22) communicated with the negative pressure cavity (14) is installed on the cover plate (2). A sliding cavity (221) is formed inside the positioning sleeve (22), and an installation cavity (222) is communicated with the end of the sliding cavity (221). A pressure relief hole (223) for pressure relief is formed on the side wall of the sliding cavity (221), and the bottom of the sliding cavity (221) is movably connected with the piston (23).

5. The split top formwork structure according to claim 4, characterized in that, A sliding rod (231) is installed on the piston (23). The sliding rod (231) movably penetrates through the positioning sleeve (22). A limiting plate (233) is installed on the side wall of the sliding rod (231). The limiting plate (233) is lapped above the positioning sleeve (22). A return spring (232) is sleeved on the side wall of the sliding rod (231). One end of the return spring (232) is clamped on the inner side wall of the installation cavity (222), and the other end of the return spring (232) is clamped on the upper surface of the piston (23).

6. The split top formwork structure according to claim 5, characterized in that, A connecting plate (244) is installed at the top of the sliding rod (231). The connecting plate (244) is placed above the connecting pipe (21), and a guiding cover (242) is installed at the bottom of the connecting plate (244). The guiding cover (242) is conical, and its bottom is inserted into the bottom of the connecting pipe (21). Two vertical rods (241) are connected to the bottom of the guiding cover (242). The two vertical rods (241) are parallel to each other, and the bottoms of the vertical rods (241) are connected to the surface of the flow splitting table (24).

7. The split top formwork structure according to claim 1, characterized in that, A conical arc surface (211) is formed at the bottom of the connecting pipe (21). The surface of the flow splitting table (24) is inclined, and the connecting pipe (21) is adapted to the flow splitting table (24). An inner groove (213) is formed on the cover plate (2). The inner groove (213) is annular. A collecting cover (212) is installed on the inner groove (213) through bolts. The collecting cover (212) is sleeved outside the connecting pipe (21). The top of the connecting pipe (21) and the top of the collecting cover (212) are on the same plane, and the outer edge of the top of the collecting cover (212) is chamfered.

8. The split top formwork structure according to claim 1, characterized in that, A rotating shaft (31) is installed on the turntable (3). The rotating shaft (31) movably penetrates through the cover plate (2). A knob (311) is installed at the end of the rotating shaft (31), and an adapting protrusion is installed on the knob (311). A torsion spring (312) is sleeved on the rotating shaft (31). One end of the torsion spring (312) is clamped to the bottom of the cover plate (2), and the other end is clamped to the turntable (3).

9. The split top formwork structure according to claim 1, characterized in that, A negative pressure pipe (321) is connected to the bottom of the negative pressure chamber (14). The surface of the turntable (3) is attached to the negative pressure port of the negative pressure pipe (321), and the size of the notch (32) is larger than that of the negative pressure pipe (321).

10. The split top formwork structure according to claim 1, characterized in that, A compensation cover (335) is installed at the bottom of the negative pressure chamber (14). A push plate (333) slides inside the compensation cover (335). A push rod (331) is installed on the push plate (333). The push rod (331) movably penetrates through the compensation cover (335). A rolling ball (332) is installed at the end of the push rod (331). The rolling ball (332) is slidably connected to a slope (334) formed on the surface of the guiding block (33).

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