Large casting low pressure casting equipment with multi-lift tube and lift tube protection method

Abstract

The application discloses a kind of super large casting low-pressure casting equipment with multiple liquid lift pipes, including holding furnace, multiple liquid lift pipes, gas inlet pipe and multiple bypass pipes, the holding furnace is formed with the accommodation cavity for placing melt;One end of each of the liquid lift pipe is communicated to the accommodation cavity, and the other end of each liquid lift pipe is used to selectively externally connected to mold cavity according to different castings to be cast;One end of the gas inlet pipe is used to externally connected to gas source, and the other end is communicated to the accommodation cavity;The bypass pipe is same in number with the liquid lift pipe and one-to-one correspondence, which is communicated between the gas inlet pipe and each corresponding liquid lift pipe.In use, the valve between unused liquid lift pipe and gas inlet pipe can be opened, at this time, the pressure of both ends of unused liquid lift pipe is almost the same due to simultaneously communicating with gas inlet pipe, and melt cannot be pushed to flow by pressure difference, so it is not necessary to extract the liquid lift pipe or to block it, and aluminum liquid cannot go up, so it is not necessary to clean the unused liquid lift pipe, and the flexibility is higher.

Description

Technical Field

[0001] This invention belongs to the field of casting equipment technology, specifically relating to a low-pressure casting equipment for ultra-large castings with multiple liquid riser pipes, and a method for protecting the liquid riser pipes. Background Technology

[0002] In modern casting, low-pressure casting is widely used due to its high material utilization, high-quality castings, high production efficiency, low cost, and good working conditions. In low-pressure casting, riser pipes are crucial auxiliary materials that play a decisive role in product quality and production efficiency; however, the value of a riser pipe over its lifespan is ultimately determined by its service life. Even with any protective coating, its lifespan is relatively short, and it can contaminate the molten metal. Later-used silicon carbide and alumina riser pipes do not corrode or cause iron buildup, but their inner insulation layer gradually peels off when cleaning aluminum slag and slag, losing its insulation effect, cracking, and even losing its seal, rendering them unusable. Furthermore, these materials cannot withstand drastic temperature changes; they are prone to cracking and failure when the temperature difference changes rapidly. Although silicon nitride has been used to make riser pipes in recent years, even with its high strength, fracture due to temperature differences is still unavoidable. Especially with the diversification and weight of products today, multi-cavity molds and multi-mold machine combinations are becoming increasingly common, leading to a higher proportion of multi-riser pipes being used. However, not all molds can satisfy only one production state. The number of riser pipes used will change with the change of molds. At this time, how to deal with the unused riser pipes becomes an urgent problem to be solved.

[0003] When a casting machine has multiple riser pipes, it can simultaneously install and adapt to multiple sets of molds, or use all riser pipes to produce sufficiently large products. However, the same position or number of riser pipes are not always used. Therefore, it is necessary to adapt the riser pipes according to the number and position required by the mold at that time. Other unnecessary riser pipes can either be removed and the channel opening sealed, or they can be left in place and sealed at the pipe opening with a gasket at the same height to prevent the molten metal from flowing out. Most of the riser pipes removed in the former case will likely crack and become unusable due to sudden temperature changes during reinstallation, and the operation cannot be too fast, which will delay the work time. The latter can extend the service life by 3-5 times compared to the former, but after each mold disassembly, no matter what kind of gasket is used, the pipe opening cannot be completely sealed, and a thick metal scale will form at the pipe opening, which requires a lot of time to remove the metal scale, and is extremely labor-intensive and resource-intensive.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a low-pressure casting equipment for ultra-large castings with multiple liquid riser pipes, so as to solve the problem of handling unused liquid riser pipes.

[0006] To achieve the above objectives, a specific embodiment of the present invention provides a low-pressure casting equipment for ultra-large castings with multiple liquid riser pipes, including a holding furnace, multiple liquid riser pipes, an air inlet pipe, and multiple bypass pipes. The holding furnace forms a accommodating cavity for holding molten metal. One end of each liquid riser pipe is connected to the accommodating cavity, and the other end of each liquid riser pipe is selectively connected to a mold cavity according to different castings to be cast. One end of the air inlet pipe is connected to an external air source, and the other end is connected to the accommodating cavity. The bypass pipes are connected to the liquid riser pipes. The number of pipes is the same and they correspond one-to-one, and they are connected to the air inlet pipe and their respective corresponding liquid riser pipes; wherein a valve is provided between the air inlet pipe and each liquid riser pipe, and in the working state of the ultra-large casting low-pressure casting equipment with multiple liquid riser pipes, the multiple liquid riser pipes are divided into a first liquid riser pipe connected to the mold cavity and a second liquid riser pipe not connected to the mold cavity, the valve between the first liquid riser pipe and the air inlet pipe is in a closed state, and the valve between the second liquid riser pipe and the air inlet pipe is in an open state.

[0007] In one or more embodiments of the present invention, the bypass pipe is detachably connected to the riser pipe.

[0008] In one or more embodiments of the present invention, the bypass pipe is detachably connected to the intake pipe.

[0009] In one or more embodiments of the present invention, the valve is disposed near the air inlet pipe.

[0010] In one or more embodiments of the present invention, the valve is located near the connection between the riser pipe and the cavity.

[0011] In one or more embodiments of the present invention, the bypass pipe is a high-temperature resistant flexible hose.

[0012] In one or more embodiments of the present invention, the bypass pipe, the air inlet pipe, and the riser pipe are connected by quick-connect couplings.

[0013] In one or more embodiments of the present invention, a liquid inlet pipe is disposed on the outer wall of the holding furnace and communicates with the accommodating cavity, the liquid inlet pipe being used to deliver molten liquid into the accommodating cavity.

[0014] This invention also provides a method for protecting the riser pipes of the above-mentioned low-pressure casting equipment for ultra-large castings with multiple riser pipes, comprising the following steps:

[0015] S1. Fix the mold to a low-pressure casting equipment for ultra-large castings with multiple liquid riser pipes, and connect one or more of the liquid riser pipes to the mold cavity.

[0016] S2. Close the valve between the first liquid riser pipe and the air inlet pipe, and open the valve between the second liquid riser pipe and the air inlet pipe;

[0017] S3. The molten liquid is supplied into the holding furnace through the liquid inlet pipe, and the gas is supplied into the holding furnace through the gas inlet pipe to press the molten liquid into the mold cavity, and wait for the molten liquid to solidify.

[0018] Compared with existing technologies, the low-pressure casting equipment for ultra-large castings with multiple riser pipes of the present invention connects each riser pipe to the air inlet pipe and controls its on / off state through valves. The valves corresponding to the riser pipes that are needed are closed, allowing the molten metal in the holding furnace to be forced into the mold cavity under the action of pressure differential. For unused riser pipes, their corresponding valves are opened. At this time, since both ends of the riser pipe are simultaneously connected to the air inlet pipe, the air pressure at both ends is the same, and the pressure differential cannot drive the molten metal to flow. Therefore, there is no need to remove or block the riser pipes, resulting in higher flexibility. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a cross-sectional view of a low-pressure casting equipment for ultra-large castings with multi-liter liquid pipes according to an embodiment of the present invention.

[0021] Figure 2 This is a flowchart of a method for protecting the riser tube in one embodiment of the present invention.

[0022] Explanation of key figure labels:

[0023] 100 - Low-pressure casting equipment for ultra-large castings with multiple liquid pipes, 10 - Insulation furnace, 20 - Liquid pipe, 30 - Air inlet pipe, 40 - Bypass pipe, 50 - Valve, 60 - Mold, 70 - Cavity, 80 - Liquid aluminum. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0025] like Figure 1 As shown, an embodiment of the present invention discloses a low-pressure casting equipment 100 for ultra-large castings with multiple liquid risers, mainly used for casting ultra-large castings (it can also be applied to castings of other volumes). It includes a holding furnace 10, multiple liquid risers 20, an air inlet pipe 30, multiple bypass pipes 40, and valves 50. The holding furnace 10 has a receiving cavity for storing molten aluminum 80 (or other casting molten material; for ease of explanation, molten aluminum is used as an example here). The holding furnace 10 is equipped with multiple liquid risers 20, one end of which is connected to the receiving cavity of the holding furnace 10, and the other end is selectively connected to the cavity 70 within the mold 60 of the casting to be produced, depending on the different castings and quantities. One end of the air inlet pipe 30 is used to connect to an external air source, and the other end is connected to the internal receiving cavity. It pressurizes the cavity by supplying gas to the receiving cavity, thereby forcing the molten aluminum inside through the liquid risers 20 into the cavity 70. The number of bypass pipes 40 and riser pipes 20 are the same and correspond one-to-one. The riser pipes 20 are connected to the air inlet pipes 30 through the bypass pipes 40. The valves 50 are set between the air inlet pipes 30 and each riser pipe 20 to control the opening and closing of the bypass pipes 40.

[0026] Depending on the different castings being made, multiple riser pipes 20 need to be selectively connected to cavities 70 within the molds 60 corresponding to different castings. In this embodiment, the low-pressure casting equipment 100 for ultra-large castings with multiple riser pipes is in operation with the receiving cavity filled with molten aluminum 80. One end of the air inlet pipe 30 is connected to an external air source, and the other end is connected to the receiving cavity and located above the molten aluminum 80. In operation, the riser pipes 20 can be divided into a first riser pipe 21 connected to the cavity 70 (due to viewing angle limitations, the bypass pipe connecting the first riser pipe 21 is...). Figure 1 (Not shown in the image), and the second liquid riser pipe 22 is not connected to the cavity 70. Furthermore, in the operating state of the low-pressure casting equipment 100 for ultra-large castings with multiple liquid riser pipes, the valve 50 between the second liquid riser pipe 22 and the air inlet pipe 30 is open, while the valve 50 between the first liquid riser pipe 21 and the air inlet pipe 30 is closed. When gas is supplied and pressurized into the holding furnace 10 through the air inlet pipe 30, because the valve 50 between the second liquid riser pipe 22 and the air inlet pipe 30 is opened, the gas in the air inlet pipe 30 is divided into two paths. One path leads directly to the receiving cavity, and the other path passes through the bypass pipe 40 and the second liquid riser pipe 22 before entering the molten aluminum 80. Therefore, the gas pressure at the end of the second liquid riser pipe 22 away from the receiving cavity (22A) is almost the same as the gas pressure inside the receiving cavity, and the molten aluminum 80 cannot flow upwards through the second liquid riser pipe 22. Since the valve 50 between the first liquid riser pipe 21 and the air inlet pipe 30 is closed, the gas in the air inlet pipe 30 cannot flow to the end of the first liquid riser pipe 21 near the cavity 70. The gas pressure of the first liquid riser pipe 21 at one end (21A) of the cavity 70 is less than the gas pressure in the accommodating cavity. Under the action of the pressure difference, the aluminum liquid 80 flows upward through the first liquid riser pipe 21 into the cavity 70.

[0027] Therefore, after setting the bypass pipe 40 and valve 50, the aluminum liquid can be prevented from flowing upward by opening the valve 50 corresponding to the unused second riser pipe 22. This avoids unnecessary operations such as blocking or disassembling the riser pipe 20 that does not need to participate in the work, as well as removing the aluminum sheet later. This results in higher flexibility and production efficiency.

[0028] In the above embodiments, the number and position of the first riser pipes 21 are merely illustrative. Depending on the casting, multiple first riser pipes 21 can be selected, that is, one end of multiple riser pipes 20 is connected to the cavity 70 inside the mold 60 of the casting to be produced. In some cases, all riser pipes 20 are connected to the cavity 70, in which case the number of second riser pipes 22 is zero.

[0029] In one embodiment, the bypass pipe 40 is designed to be detachable, for example, it may be detachably connected to one of the riser pipe 20 and the air inlet pipe 30, or to both, thereby increasing flexibility.

[0030] Since each riser pipe 20 is equipped with a bypass line, one or more riser pipes 20 can be selected for each production run. Furthermore, a second, previously unused riser pipe 22 can be used for casting production during the process, offering high flexibility.

[0031] In other embodiments, the riser pipe 20 for long-term use may also be optional and not connected to the bypass pipe 40 (e.g. Figure 1 The first riser pipe 21 in the middle), and only the riser pipe 20 that is unlikely to be used is connected to the air inlet pipe 30 through the bypass pipe 40 (e.g. Figure 1 The second liquid-lifting pipe 22 in the middle further reduces production costs.

[0032] Specifically, although the bypass pipe 40 does not participate in the flow of molten aluminum, the temperature inside the bypass pipe 40 is also high due to the high temperature of the molten aluminum. Therefore, in one embodiment, a high-temperature resistant flexible hose is used as the bypass pipe 40. While ensuring the bypass effect, the flexible hose is also easy to connect and has high flexibility.

[0033] In one embodiment, the valve 50 can be located on the side near the air inlet pipe 30. When there are a large number of riser pipes 20, the centralized arrangement of the valves 50 also facilitates operation by the staff. Of course, for easy identification, the valve 50 can also be located on the side near the riser pipe 20 and near the cavity 70. This embodiment is not limited to this.

[0034] Preferably, the bypass pipe 40 is connected to the air inlet pipe 30 and the liquid riser pipe 20 through quick-connect couplings (such as threaded couplings, snap-fit ​​couplings, etc.) to achieve quick connection and disconnection and improve production efficiency.

[0035] like Figure 2 As shown, in combination with specific usage scenarios, a method for protecting the riser pipe 20 in the low-pressure casting equipment 100 for ultra-large castings with multiple liquid riser pipes in this embodiment is provided. The specific usage method after setting the bypass pipe 40 and valve 50 includes the following steps:

[0036] S1. Fix the mold 60 to the low-pressure casting equipment 100 for ultra-large castings with multiple liquid risers, and connect the liquid riser 20 to the cavity 70.

[0037] Specifically, the mold 60 is fixed to the low-pressure casting equipment 100 for ultra-large castings with multiple liquid pipes, and one of the liquid pipes 20 is connected to the cavity 70.

[0038] S2. Close the valve 50 between the riser pipe 20 connected to the mold and the air inlet pipe 30, and open the valve 50 between the riser pipe 20 not connected to the mold and the air inlet pipe 30.

[0039] Specifically, the valve 50 between the riser pipe 20 and the air inlet pipe 30 that connects to the mold cavity is closed, so that the air inlet pipe 30 does not apply pressure at the connection point between the riser pipe 20 and the mold cavity. At the same time, the valve 50 between the unused riser pipe 20 and the air inlet pipe 30 is opened, so that both ends of the riser pipe 20 are connected to the air inlet pipe 30 at the same time, and the pressure at both ends of the riser pipe 20 is equal.

[0040] S3. Liquid aluminum is supplied into the holding furnace through the liquid inlet pipe, and gas is supplied into the holding furnace through the gas inlet pipe to pressurize the aluminum into the mold cavity.

[0041] After the connection is completed and the corresponding valve 50 is opened and closed, molten aluminum is supplied into the holding furnace 10 through the liquid inlet pipe, and then gas is supplied into the holding furnace 10 through the gas inlet pipe 30. Because the valve 50 corresponding to the riser pipe 20 connecting the mold cavity is closed, the gas pressure at one end of the mold cavity is lower than the gas pressure inside the furnace, and the molten aluminum is forced into the mold cavity. Since the riser pipe 20 is not used to equalize the pressure at both ends, the molten aluminum cannot rise and is retained at one end of the furnace. After the molten aluminum in the mold cavity cools and solidifies, the mold is opened and the part is removed.

[0042] For example, in such Figure 1 In the embodiment shown, after the mold 60 is fixedly connected to the ultra-large casting low-pressure casting equipment 100 with multiple liquid pipes, the first liquid pipe 21 is connected to the mold cavity 70 and the valve 50 in its corresponding pipe is closed. The valves 50 in the corresponding pipes of the second liquid pipes 22 on both sides are opened. Then, the air is pressurized through the air inlet pipe 30 to pressurize the aluminum into the cavity 70 and wait for solidification.

[0043] In other embodiments, when the base plate of the mold 60 prevents direct connection to the air inlet pipe 30 and the second liquid riser pipe 22, the first liquid riser pipe 21 can be directly connected to the cavity 70. A hole is made on the base plate of the mold 60 corresponding to the position of the second liquid riser pipe 22. A connector is welded to the other end of the hole and connected to the bypass pipe 40, connecting the second liquid riser pipe 22 to this hole. In this case, one end of the second liquid riser pipe 22 is connected to the air inlet pipe 30 through the bypass pipe 40, ensuring that the pressure in the second liquid riser pipe 22 is the same as that inside the holding furnace 10, preventing the aluminum liquid from flowing within the second liquid riser pipe 22. However, it is important to note that this method requires drilling holes in the mold base plate, which may disrupt the consistency of the mold. Furthermore, it is necessary to ensure the airtightness between the second liquid riser pipe 22 and the opening to prevent the aluminum liquid from still flowing within the second liquid riser pipe 22 due to gaps.

[0044] By setting up the bypass pipe 40 and valve 50, the valve 50 corresponding to the unused second riser pipe 22 can be opened. At this time, the air pressure inside the second riser pipe 22 is the same as the air pressure inside the holding furnace 10, so the aluminum liquid cannot flow upwards, avoiding the need to block or disassemble the riser pipe 20 that is not used. Furthermore, since the aluminum liquid cannot flow upwards, no aluminum shavings will be generated inside the second riser pipe 22 after use, thus avoiding unnecessary operations such as subsequent aluminum shavings removal, protecting the second riser pipe 22, and offering high flexibility and production efficiency.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0046] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A low-pressure casting equipment for ultra-large castings with multi-liter liquid pipes, characterized in that, include: A holding furnace having a cavity for holding molten metal; Multiple riser tubes, one end of each riser tube is connected to the receiving cavity, and the other end of each riser tube is used to selectively connect to the mold cavity according to different castings to be cast; An air intake pipe, one end of which is connected to an external air source, and the other end connected to the accommodating cavity; and Multiple bypass pipes, the same number as the riser pipes and corresponding one-to-one, are connected to the air inlet pipe and their respective riser pipes. The air inlet pipe is equipped with a valve between each riser pipe and the air inlet pipe. In the working state of the low-pressure casting equipment for ultra-large castings with multiple riser pipes, the multiple riser pipes are divided into a first riser pipe connected to the mold cavity and a second riser pipe not connected to the mold cavity. The valve between the first riser pipe and the air inlet pipe is in a closed state, and the valve between the second riser pipe and the air inlet pipe is in an open state.

2. The low-pressure casting equipment for ultra-large castings with multi-liter liquid pipes according to claim 1, characterized in that, The bypass pipe is detachably connected to the riser pipe.

3. The low-pressure casting equipment for ultra-large castings with multi-liter liquid pipes according to claim 1, characterized in that, The bypass pipe is detachably connected to the intake pipe.

4. The low-pressure casting equipment for ultra-large castings with multi-liter liquid pipes according to claim 1, characterized in that, The valve is located near the air inlet pipe.

5. The low-pressure casting equipment for ultra-large castings with multi-liter liquid pipes according to claim 1, characterized in that, The valve is located near the connection between the riser pipe and the cavity.

6. The low-pressure casting equipment for ultra-large castings with multi-liter liquid pipes according to claim 1, characterized in that, The bypass pipe is a high-temperature resistant flexible hose.

7. The low-pressure casting equipment for ultra-large castings with multi-liter liquid pipes according to claim 1, characterized in that, The bypass pipe, air inlet pipe, and riser pipe are connected by quick-connect couplings.

8. The low-pressure casting equipment for ultra-large castings with multi-liter liquid pipes according to claim 1, characterized in that, It also includes a liquid inlet pipe disposed on the outer wall of the holding furnace and connected to the accommodating cavity, the liquid inlet pipe being used to deliver molten liquid into the accommodating cavity.

9. The method for protecting the riser pipes in a low-pressure casting equipment for ultra-large castings with multiple riser pipes according to claim 1, characterized in that, Includes the following steps: S1. Fix the mold to a low-pressure casting equipment for ultra-large castings with multiple liquid riser pipes, and connect one or more of the liquid riser pipes to the mold cavity. S2. Close the valve between the first liquid riser pipe and the air inlet pipe, and open the valve between the second liquid riser pipe and the air inlet pipe; S3. The molten liquid is supplied into the holding furnace through the liquid inlet pipe, and the gas is supplied into the holding furnace through the gas inlet pipe to press the molten liquid into the mold cavity, and wait for the molten liquid to solidify.

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