A mold casting device

Abstract

The present invention discloses a mold casting device, which includes a bellows, a sealed tank, a rapid cooling structure and a plunger rod. The bellows is communicated with the sealed tank through a pneumatic pipe fitting. A lower mold is provided at the upper end of the sealed tank, and an upper mold is provided at the upper end of the lower mold. A mold cavity is formed on the lower end surface of the upper mold. A riser pipe is provided on the lower end surface of the lower mold. The lower port of the riser pipe is placed at the bottom of the chamber of the sealed tank, and the upper port of the riser pipe is communicated with a runner formed in the lower mold. The runner is communicated with an annular runner formed on the upper end surface of the lower mold. The annular runner cooperates with the mold cavity and is mutually communicated. This casting device adopts a top-down solidification process, which can realize pressure feeding and compensation during the solidification process of the casting, improve the casting quality. At the same time, the design of the annular runner can ensure that the casting is always in a process of a uniformly stressed ring during the solidification process, with uniform shape and size. In addition, the use of the plunger rod can prevent oxides from entering the mold cavity along with the riser pipe, avoiding the influence on the quality of the casting.

Description

Technical Field

[0001] The present invention relates to a casting device, in particular to a die casting device and method. Background Art

[0002] At present, for the casting process of aluminum alloy pattern rings, there are generally two common methods: low-pressure casting and gravity casting. Among them, low-pressure casting has the advantages of high density and good strength of the castings. However, due to the large volume of the pattern rings of tire molds, the diverse shapes and sizes of the products, the process requirements are complex, and it is difficult to determine the equipment and technical parameters, which has a great impact on the qualified rate of the finished products.

[0003] Publication No. CN201010523985.8 discloses a low-pressure casting equipment and a low-pressure casting and gravity feeding process for aluminum alloy pattern rings of tire molds; the casting equipment used therein includes a crucible and a riser pipe; a disc-shaped runner substrate is arranged on the crucible, and the lower end of the riser pipe passes through the central hole of the runner substrate and extends into the crucible; a mold substrate is hermetically covered on the runner substrate, a mold outer mold is arranged on the mold substrate, a riser is arranged at the upper end of the mold outer mold, and a runner is arranged in the mold cavity; the upper port of the riser pipe passes through the runner substrate and the mold substrate and is communicated with the runner; a stepped air chamber surrounding the runner is arranged in the inner cavity of the mold outer mold outside the runner, and the stepped air chamber has an air inlet nozzle and an air outlet nozzle.

[0004] When this casting equipment is casting, since the solidification sequence of the aluminum liquid is from bottom to top, and the lower part has a liquid inlet, which is non-uniformly distributed in the circumferential direction, there is uneven stress during the solidification process, affecting the casting solidification shape effect. In addition, when injecting aluminum liquid into the crucible, the oxides and attachments generated on the surface of the aluminum liquid will sink under the liquid surface. When pressurizing the crucible, these impurities will enter the runner with the aluminum liquid and solidify in the metal workpiece, affecting the quality of the castings. Therefore, improvement is needed. Summary of the Invention

[0005] The purpose of the present invention is to provide a die casting device and method to solve the problems raised in the above background art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A die casting device includes a bellows and a sealed tank arranged on one side of the bellows. The bellows is communicated with the sealed tank through a pneumatic pipe fitting. A lower mold is arranged at the upper end of the sealed tank, and an upper mold is arranged at the upper end of the lower mold;

[0008] A mold cavity is opened on the lower end surface of the upper mold, an inner groove hole and a riser are opened on the upper end surface of the upper mold. The inner groove hole is opened at the center of the upper mold, and the riser surrounds the inner groove hole and is communicated with the mold cavity. It also includes a rapid cooling structure and a plunger rod;

[0009] The lower end face of the lower mold is provided with a riser pipe. The lower port of the riser pipe is placed at the bottom of the sealed tank chamber. The upper port of the riser pipe is communicated with the runner opened in the lower mold. The runner is communicated with the annular runner opened on the upper end face of the lower mold. The annular runner is matched with the mold cavity and communicated with each other.

[0010] A rapid cooling structure is placed in the upper mold and communicated with the air box through pipe fittings, and is used for stage cooling of the molten aluminum in the mold cavity.

[0011] The plunger rod passes through the upper mold and the lower mold and extends into the riser pipe and is in pneumatic clamping fit with the inner groove hole. The plunger rod is movably matched with the riser pipe.

[0012] Preferably, at least two risers are opened on the upper end face of the upper mold. The lower ports of the risers are communicated with the top of the mold cavity.

[0013] Preferably, the pneumatic pipe fittings include a negative pressure pipe and a pressure pipe. One end of the negative pressure pipe is communicated with the inner cavity of the sealed tank. The other end of the negative pressure pipe is communicated with the output end of the negative pressure fan arranged in the air box. A sealing valve is arranged at the connection of the negative pressure pipe and the sealed tank. One end of the pressure pipe is communicated with the sealed tank. The other end of the pressure pipe is communicated with the output end of the booster pump arranged in the air box.

[0014] Preferably, a liquid injection pipe is arranged on one side of the sealed tank away from the air box. One end of the liquid injection pipe is communicated with the liquid injection pouring plate arranged on the inner wall of the sealed tank. A sealing valve is arranged at the other end of the liquid injection pipe.

[0015] Preferably, the rapid cooling structure includes an air-cooling groove opened in the upper mold. The air-cooling groove includes a first annular cavity, a second annular cavity and a third annular cavity corresponding to the upper half, the middle part and the lower half of the mold cavity. The upper end of the first annular cavity is communicated with the output end of the fan in the air box through an air-cooling pipe. The other end of the second annular cavity is sequentially communicated with the second annular cavity and the third annular cavity.

[0016] Preferably, the plunger rod includes a guide rod. The guide rod passes through the second through hole opened at the center of the upper mold and the first through hole opened at the center of the lower mold and is in sliding fit with the second through hole and the first through hole. The bottom end of the guide rod is fixedly connected with a counterweight slider arranged at the intersection of the riser pipe and the runner. The counterweight slider is in sliding fit with the inner wall of the riser pipe.

[0017] Preferably, the pneumatic clamping includes a connecting shell. The connecting shell is fixed on the bottom wall of the inner groove hole and corresponds to the first through hole. An annular groove hole is opened at the center of the connecting shell. Two symmetrically arranged movable blocks are arranged in the annular groove hole. The two movable blocks are placed on both sides of the guide rod and are connected with the output end of the movable column arranged in the connecting shell. The movable column is communicated with the output end of the air pump arranged in the air box through an air duct. An arc groove matched with the guide rod is opened on one side of the two movable blocks close to the guide rod.

[0018] Preferably, a retaining ring is provided at the edge of the upper end surface of the lower mold, and the retaining ring is sleeved outside the lower end of the upper mold and cooperates with the upper mold.

[0019] Preferably, a heat-insulating layer is provided on the outer wall of the annular runner in the lower mold.

[0020] A casting method for a mold casting device, comprising:

[0021] Step 1: The air in the sealed tank is replaced by the negative pressure pipe and the pressure pipe, the air pump is started, the movable column is controlled by the air guide tube to release the clamping state of the guide rod, the counterweight slider drives the guide rod to fall downward, the counterweight slider slides with the inner wall of the liquid riser to clean the inner wall of the liquid riser, and when it moves to the lower end of the liquid riser, the movable column is extended and fixed to the guide rod through the annular slot to close the lower end of the liquid riser;

[0022] Step 2: Open the valve on the injection pipe, and inject the aluminum liquid into the sealed tank through the injection pouring plate;

[0023] Step 3: The sealing valves on the negative pressure pipe and the injection pipe are closed, and the booster pump is started. The inner cavity of the sealed tank is pressurized through the pressure pipe. The air pressure pushes the aluminum liquid into the riser pipe, and then it is transported from the riser pipe to the runner and the annular runner. Finally, it is injected into the mold cavity from the annular runner. The gas in the mold cavity is discharged from the riser. After the aluminum liquid at the riser solidifies, it is continuously pressurized to compensate for the shrinkage of the casting.

[0024] Step 4: After the aluminum liquid in the mold cavity solidifies, stop pressurizing, and the uncooled aluminum liquid flows back into the sealed tank through the runner and the riser pipe.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The casting device adopts a top-down solidification process, which can realize pressure compensation during the solidification process of the casting and improve the casting quality;

[0027] The design of the annular runner on the casting device can ensure that the casting is always in a uniformly stressed circular ring process during the solidification process, and the shape and size are uniform;

[0028] The casting device uses a rapid cooling structure to cool the aluminum liquid in the mold cavity in stages from top to bottom, which can effectively improve the casting efficiency of the casting;

[0029] The use of the plunger rod on the casting device can ensure the cleanliness of the riser pipe, prevent oxides from entering the mold cavity along the riser pipe, and avoid affecting the quality of the casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The figure is a schematic diagram of the structure of a mold casting device.

[0031] Figure 2 It is a schematic structural diagram of the lower mold in a mold casting device.

[0032] Figure 3 It is a schematic structural diagram of the upper mold in a mold casting device.

[0033] Figure 4 It is a schematic structural diagram of the mold cavity in a mold casting device.

[0034] Figure 5 It is a mold casting device Figure 1 A schematic enlarged view of the structure at position A in it.

[0035] Figure 6 It is a schematic structural diagram of the connecting shell in a mold casting device.

[0036] In the figure: 1. Bellows; 2. Sealed tank; 3. Upper mold; 4. Negative pressure pipe; 5. Pressure pipe; 6. Liquid injection pouring plate; 7. Liquid injection pipe; 8. Rising pipe; 9. Lower mold; 10. Runner; 11. First perforation; 12. Retaining ring; 13. Annular runner; 14. Heat insulation layer; 15. Inner groove hole; 16. Riser; 17. Air cooling pipe; 18. Air duct; 19. Mold cavity; 20. Air cooling groove; 21. Second perforation; 22. Connecting shell; 23. Guide rod; 24. Counterweight slider; 25. Annular slot hole; 26. Movable block; 27. Movable column; 28. Arc groove. Specific implementation manners

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0038] Please refer to Figures 1 - 6 , in an embodiment of the present invention, a mold casting device includes a bellows 1 and a sealed tank 2 provided on one side of the bellows 1. The bellows 1 is communicated with the sealed tank 2 through a pneumatic pipe fitting. The upper end of the sealed tank 2 is provided with a lower mold 9, and the upper end of the lower mold 9 is provided with an upper mold 3; a mold cavity 19 is opened on the lower end surface of the upper mold 3, and an inner groove hole 15 and a riser 16 are opened on the upper end surface of the upper mold 3. At least two risers 16 are opened on the upper end surface of the upper mold 3. The inner groove hole 15 is opened at the center of the upper mold 3. The risers 16 surround the outer side of the inner groove hole 15 and are communicated with the mold cavity 19. It also includes a rapid cooling structure and a plunger rod; the molten aluminum enters the mold cavity 19 through the runner 10 and the annular runner 13, and the gas in the mold cavity 19 is discharged from the riser 16;

[0039] The lower end surface of the lower mold 9 is provided with a riser pipe 8. The lower port of the riser pipe 8 is placed at the bottom of the chamber of the sealed tank 2. The upper port of the riser pipe 8 is communicated with a runner 10 opened in the lower mold 9. The runner 10 is communicated with an annular runner 13 opened on the upper end surface of the lower mold 9. The annular runner 13 cooperates with the mold cavity 19 and is mutually communicated. The molten aluminum flows into the runner 10 through the riser pipe 8, and then flows into the annular runner 13. The annular runner 13 is a ring, which can make the molten aluminum injected into the mold cavity 19 evenly distributed. When the mold cavity 19 is filled with molten aluminum, the casting will always be in a process of a ring with uniform force during solidification, and the forces between each other cancel out, so as to keep the shape and size uniform.

[0040] The pneumatic pipe fittings include a negative pressure pipe 4 and a pressure pipe 5. One end of the negative pressure pipe 4 is communicated with the inner cavity of the sealed tank 2, and the other end of the negative pressure pipe 4 is communicated with the output end of a negative pressure fan arranged in the air box 1. A sealing valve is arranged at the connection between the negative pressure pipe 4 and the sealed tank 2. One end of the pressure pipe 5 is communicated with the sealed tank 2, and the other end of the pressure pipe 5 is communicated with the output end of a booster pump arranged in the air box 1. The sealing valves on the negative pressure pipe 4 and the injection pipe 7 are closed, the booster pump is started, and the inner cavity of the sealed tank 2 is pressurized through the pressure pipe 5. The air pressure pushes the molten aluminum into the riser pipe 8, and then is transported from the riser pipe 8 to the runner 10 and the annular runner 13, and finally is filled into the mold cavity 19 from the annular runner 13. The molten aluminum at the riser 16 solidifies, continuous pressure is applied to perform feeding on the casting until the molten aluminum in the mold cavity 19 is all solidified, then the pressure application is stopped, and the unfrozen molten aluminum flows back.

[0041] A liquid injection pipe 7 is arranged on one side of the sealed tank 2 away from the air box 1. One end of the liquid injection pipe 7 is communicated with a liquid injection pouring plate 6 arranged on the inner wall of the sealed tank 2, and a sealing valve is arranged at the other end of the liquid injection pipe 7. Before injecting the molten aluminum, the air in the sealed tank 2 is replaced through the negative pressure pipe 4 and the pressure pipe 5, the pneumatic clamping releases the fixation of the plunger rod, the plunger rod drops from the upper mold 3, while cleaning the inner wall of the riser pipe 8, it moves to the lower port of the riser pipe 8 and stops to block the riser pipe 8. At this time, the valve on the liquid injection pipe 7 is opened, and the molten aluminum is injected into the sealed tank 2 through the liquid injection pouring plate 6. At this time, the oxide slag generated on the liquid surface will not flow into the mold cavity 19 through the riser pipe 8 during casting, reducing the forming quality of the casting.

[0042] A rapid cooling structure is placed inside the upper mold 3 and connected to the air box 1 through a pipe fitting, and is used for stage cooling of the molten aluminum in the mold cavity 19. The rapid cooling structure includes an air-cooling groove 20 opened in the upper mold 3. The air-cooling groove 20 includes a first annular cavity, a second annular cavity, and a third annular cavity corresponding to the upper half, middle, and lower half of the mold cavity 19. The upper end of the first annular cavity is connected to the output end of the fan in the air box 1 through an air-cooling pipe 17, and the other end of the second annular cavity is sequentially connected to the second annular cavity and the third annular cavity. The upper port of the first annular cavity is connected to the output end of the fan in the air box 1 through an air-cooling pipe 17, the lower port of the first annular cavity is connected to the upper port of the third annular cavity through the second annular cavity, and the lower port of the third annular cavity is connected to the input end of the fan in the air box 1 through another pipe fitting. When the fan is started, the air flow can first enter the first annular cavity, then enter the second annular cavity and the third annular cavity. The number of the second annular cavities is more than that of the first annular cavity, and the number of the third annular cavities is more than that of the second annular cavity, which can enable the castings in the mold cavity 19 to be cooled sequentially. Since low-pressure casting fills the mold from bottom to top and the gate is at the lower part, in order to enable the casting to obtain sufficient compensation, sequential solidification from top to bottom must be formed. The end far from the annular runner 13 solidifies first, and the part close to the gate solidifies last, avoiding shrinkage cavity and shrinkage porosity defects in the casting after forming.

[0043] The plunger rod extends through the upper mold 3 and the lower mold 9 to the inside of the lifting pipe 8 and is in pneumatic clamping cooperation with the inner groove hole 15. The plunger rod is movably matched with the lifting pipe 8. The plunger rod includes a guide rod 23. The guide rod 23 passes through the second through hole 21 opened at the center of the upper mold 3 and the first through hole 11 opened at the center of the lower mold 9 and is slidably matched with the second through hole 21 and the first through hole 11. The bottom end of the guide rod 23 is fixedly connected to a counterweight slider 24 provided at the intersection of the lifting pipe 8 and the runner 10. The counterweight slider 24 is slidably matched with the inner wall of the lifting pipe 8.

[0044] The pneumatic clamping includes a connecting housing 22. The connecting housing 22 is fixed to the bottom wall of the inner groove hole 15 and corresponds to the first through hole 11. An annular groove hole 25 is opened at the center of the connecting housing 22. Two symmetrically arranged movable blocks 26 are provided in the annular groove hole 25. The two movable blocks 26 are placed on both sides of the guide rod 23 and are connected to the output end of a movable column 27 provided in the connecting housing 22. The movable column 27 is connected to the output end of an air pump provided in the air box 1 through an air duct 18. An arc-shaped groove 28 matched with the guide rod 23 is opened on one side of the two movable blocks 26 close to the guide rod 23. When replacing the air in the replacement sealing tank 2, the air pump is started, and the movable column 27 is controlled through the air duct 18 to release the clamping state of the guide rod 23. The counterweight slider 24 drives the guide rod 23 to fall. The counterweight slider 24 is slidably matched with the inner wall of the lifting pipe 8 to clean the inner wall of the lifting pipe 8. When moving to the lower port of the lifting pipe 8, the movable column 27 expands and contracts and fixes the guide rod 23 through the movable block 26, thereby closing the lower port of the lifting pipe 8.

[0045] A retaining ring 12 is provided at the edge of the upper end surface of the lower mold 9. The retaining ring 12 is sleeved outside the lower end of the upper mold 3 and cooperates with the upper mold 3. A heat preservation layer 14 is provided on the outer wall of the annular runner 13 inside the lower mold 9. After the aluminum liquid in the mold cavity 19 is formed, the pressure pipe 5 stops applying pressure to the sealed tank 2, and the uncooled aluminum liquid can flow back into the sealed tank 2 through the runner 10 and the riser pipe 8. The heat preservation layer 14 surrounds the outside of the annular runner 13 to reduce heat loss. When the aluminum liquid in the mold cavity 19 is solidifying, the aluminum liquid in the annular runner 13 can still remain in an unfrozen state, reducing waste of aluminum liquid.

[0046] The working principle of the present invention: The air in the sealed tank 2 is replaced through the negative pressure pipe 4 and the pressure pipe 5. The air pump is started, and the movable column 27 is controlled through the air conduit 18 to release the clamping state of the guide rod 23. The counterweight slider 24 drives the guide rod 23 to fall. The counterweight slider 24 is slidably matched with the inner wall of the riser pipe 8 to clean the inner wall of the riser pipe 8. When it moves to the lower port of the riser pipe 8, the movable column 27 expands and contracts to fix the guide rod 23 through the annular slot 25, closing the lower port of the riser pipe 8. The valve on the injection pipe 7 is opened, and the aluminum liquid is injected into the sealed tank 2 through the injection pouring plate 6. The sealing valves on the negative pressure pipe 4 and the injection pipe 7 are closed, and the booster pump is started. The inner cavity of the sealed tank 2 is pressurized through the pressure pipe 5, and the air pressure pushes the aluminum liquid into the riser pipe 8, and then is transported from the riser pipe 8 to the runner 10 and the annular runner 13, and finally is poured into the mold cavity 19 from the annular runner 13. The gas in the mold cavity 19 is discharged from the riser 16. After the aluminum liquid at the riser 16 solidifies, continuous pressure is applied to perform feeding for the casting. After the aluminum liquid in the mold cavity 19 is all solidified, the pressure application is stopped, and the uncooled aluminum liquid flows back into the sealed tank 2 through the runner 10 and the riser pipe 8.

[0047] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention.

Claims

1. A mold casting device, comprising a bellows (1) and a sealed tank (2) provided on one side of the bellows (1). The bellows (1) is communicated with the sealed tank (2) through a pneumatic pipe fitting. The upper end of the sealed tank (2) is provided with a lower mold (9), and the upper end of the lower mold (9) is provided with an upper mold (3). The lower end face of the upper mold (3) is provided with a mold cavity (19). The upper end face of the upper mold (3) is provided with an inner groove hole (15) and a riser (16). The inner groove hole (15) is opened at the center of the upper mold (3). The riser (16) surrounds the inner groove hole (15) and is communicated with the mold cavity (19). Characterized in that it further comprises a rapid cooling structure and a plunger rod. The lower end face of the lower mold (9) is provided with a riser pipe (8). The lower port of the riser pipe (8) is placed at the bottom of the chamber of the sealed tank (2). The upper port of the riser pipe (8) is communicated with a runner (10) opened in the lower mold (9). The runner (10) is communicated with an annular runner (13) opened on the upper end face of the lower mold (9). The annular runner (13) cooperates with the mold cavity (19) and is mutually communicated. The rapid cooling structure is placed in the upper mold (3) and is communicated with the bellows (1) through a pipe fitting, and is used for stage cooling of the molten aluminum in the mold cavity (19). The plunger rod passes through the upper mold (3) and the lower mold (9) and extends into the riser pipe (8) and is in pneumatic clamping cooperation with the inner groove hole (15) provided therein. The plunger rod is movably cooperated with the riser pipe (8).

2. A mold casting device according to claim 1, Characterized in that at least two risers (16) are opened on the upper end face of the upper mold (3), and the lower ports of the risers (16) are communicated with the top of the mold cavity (19).

3. A mold casting device according to claim 1, Characterized in that The pneumatic pipe fitting includes a negative pressure pipe (4) and a pressure pipe (5). One end of the negative pressure pipe (4) is communicated with the inner cavity of the sealed tank (2). The other end of the negative pressure pipe (4) is communicated with the output end of a negative pressure fan provided in the bellows (1). A sealing valve is provided at the connection between the negative pressure pipe (4) and the sealed tank (2). One end of the pressure pipe (5) is communicated with the sealed tank (2). The other end of the pressure pipe (5) is communicated with the output end of a booster pump provided in the bellows (1).

4. A mold casting device according to claim 3, Characterized in that A liquid injection pipe (7) is provided on one side of the sealed tank (2) away from the bellows (1). One end of the liquid injection pipe (7) is communicated with a liquid injection pouring plate (6) provided on the inner wall of the sealed tank (2). A sealing valve is provided at the other end of the liquid injection pipe (7).

5. A mold casting device according to claim 1, Characterized in that The rapid cooling structure includes an air-cooling groove (20) opened in the upper mold (3). The air-cooling groove (20) includes a first annular cavity, a second annular cavity and a third annular cavity corresponding to the upper half, the middle part and the lower half of the mold cavity (19). The upper end of the first annular cavity is communicated with the output end of a fan in the bellows (1) through an air-cooling pipe (17). The other end of the first annular cavity is sequentially communicated with the second annular cavity and the third annular cavity.

6. A mold casting device according to claim 4, characterized in that, the plunger rod member includes a guide rod (23), the guide rod (23) passes through a second through hole (21) opened at the center of the upper mold (3) and a first through hole (11) opened at the center of the lower mold (9) and is slidably matched with the second through hole (21) and the first through hole (11), the bottom end of the guide rod (23) is fixedly connected to a counterweight slider (24) provided at the intersection of the lift pipe (8) and the runner (10), and the counterweight slider (24) is slidably matched with the inner wall of the lift pipe (8).

7. A mold casting device according to claim 6, characterized in that, the pneumatic clamping includes a connecting housing (22), the connecting housing (22) is fixed to the bottom wall of the inner slot hole (15) and corresponds to the first through hole (11), a circular groove hole (25) is opened at the center of the connecting housing (22), two symmetrically arranged movable blocks (26) are provided in the circular groove hole (25), the two movable blocks (26) are placed on both sides of the guide rod (23) and are connected to the output end of a movable column (27) provided in the connecting housing (22), the movable column (27) is communicated with the output end of an air pump provided in the air box (1) through an air duct (18), and an arc-shaped groove (28) matched with the guide rod (23) is opened on one side of the two movable blocks (26) close to the guide rod (23).

8. A mold casting device according to claim 1, characterized in that, a retaining ring (12) is provided at the edge of the upper end surface of the lower mold (9), and the retaining ring (12) is sleeved outside the lower end of the upper mold (3) and is matched with the upper mold (3).

9. A mold casting device according to claim 1, characterized in that, a heat preservation layer (14) is provided on the outer wall of the annular runner (13) in the lower mold (9).

10. A casting method of a mold casting device according to claim 7, characterized in that, includes: Step 1: Replace the air in the sealed tank (2) through the negative pressure pipe (4) and the pressure pipe (5), start the air pump, control the movable column (27) through the air duct (18) to release the clamping state of the guide rod (23), the counterweight slider (24) drives the guide rod (23) to fall, the counterweight slider (24) is slidably matched with the inner wall of the lift pipe (8) to clean the inner wall of the lift pipe (8), when moving to the lower port of the lift pipe (8), the movable column (27) expands and contracts to fix the guide rod (23) through the circular groove hole (25) to close the lower port of the lift pipe (8); Step 2: Open the valve on the liquid injection pipe (7), and inject the molten aluminum into the sealed tank (2) through the liquid injection pouring plate (6). Step 3: Close the sealing valves on the negative pressure pipe (4) and the liquid injection pipe (7), start the booster pump, pressurize the inner cavity of the sealed tank (2) through the pressure pipe (5), the air pressure pushes the molten aluminum into the riser pipe (8), and then conveys it from the riser pipe (8) to the runner (10) and the ring runner (13), and finally fills it into the mold cavity (19) from the ring runner (13). The gas in the mold cavity (19) is discharged from the riser (16). After the molten aluminum at the riser (16) solidifies, continue to pressurize to compensate for the shrinkage of the casting; Step 4: After the molten aluminum in the mold cavity (19) has completely solidified, stop pressurizing, and the uncooled molten aluminum flows back into the sealed tank (2) through the runner (10) and the riser pipe (8).

Images