Low pressure casting pool holding furnace molten aluminum delivery device and method

Abstract

The present application belongs to the technical field of molten aluminum conveying, and relates to a molten aluminum conveying device for a low-pressure casting pool-type holding furnace, comprising an out-furnace pipeline, an in-furnace pipeline, a furnace door and a handle. The out-furnace pipeline is in an inverted U-shaped structure, the front end of the out-furnace pipeline is inserted into a molten aluminum transfer device, the tail end is connected with the in-furnace pipeline, and the tail end of the in-furnace pipeline extends into the low-pressure casting pool-type holding furnace. The in-furnace pipeline is an inclined pipeline, and the tail end is directed towards the bottom of the low-pressure casting pool-type holding furnace. Under the action of the pressure head formed by the height difference between the molten aluminum transfer device and the molten aluminum liquid level in the low-pressure casting pool-type holding furnace, the molten aluminum in the molten aluminum transfer device is automatically sucked below the molten aluminum liquid level in the low-pressure casting pool-type holding furnace, thereby avoiding the oxidation of the molten aluminum caused by splashing, tumbling and turbulence of the molten aluminum directly poured into the low-pressure casting pool-type holding furnace, and reducing the waste of the molten aluminum, the increase of the work of removing slag and the problem of pinhole in the castings caused by the absorption of air by the molten aluminum during pouring.

Description

Technical Field

[0001] The present invention belongs to the technical field of aluminum liquid transportation, and particularly relates to a device and method for transporting aluminum liquid in a low-pressure casting pool-type holding furnace. Background Art

[0002] As a commonly used casting equipment in aluminum alloy casting enterprises, the holding furnaces supporting low-pressure casting machines mainly include crucible-type holding furnaces and pool-type holding furnaces. For low-pressure casting equipment with continuous production, pool-type holding furnaces are mostly used. Usually, the furnace mouth of the pool-type holding furnace is inclined, and the pressing and sealing device is also inclined. The addition of aluminum liquid is completed by manually rotating the rotating wheel of the open-type aluminum liquid transfer device or by using a forklift for rotation. In case of space limitation where direct rotation for pouring is not possible, the aluminum liquid is poured into the cross bridge and then flows into the furnace through the cross bridge.

[0003] After retrieval, CN 202022496114.3 discloses an aluminum liquid transfer system, which includes a ladle arranged on a support platform. The ladle is provided with an "n"-type aluminum liquid pouring port and an air inlet. The aluminum liquid pouring port can extend below the liquid level of the aluminum liquid in the holding furnace, and compressed air can be introduced through the air inlet. This transfer system can reduce the agitation of aluminum liquid during direct pouring, avoid bringing impurities at the bottom of the holding furnace into the aluminum liquid, and improve the quality of aluminum liquid; by controlling the time of introducing compressed gas, the amount of aluminum liquid added is controlled to achieve quantitative filling.

[0004] Defects and deficiencies:

[0005] The open-type aluminum liquid transfer device rotates to pour aluminum liquid, mainly existing in: personnel operate at close range, and there are unsafe factors such as easy bumping and splashing of aluminum liquid during the rotation process; at the same time, due to large drop and turbulent flow during direct pouring, there are more oxidation slag and higher gas content in the aluminum liquid poured into the holding furnace (especially when using the cross bridge), resulting in waste of aluminum liquid, increased slag skimming work and poor quality of castings poured.

[0006] The invention of CN 202022496114.3 needs to pour the melted aluminum liquid into the ladle of this system first. During this pouring process, the aluminum liquid tumbles, causing oxidation and gas absorption of the processed aluminum liquid, reducing the quality of aluminum liquid; this system adopts a structure that uses compressed gas to press out the aluminum liquid. Therefore, after each reception of aluminum liquid, the furnace cover needs to be sealed, and the operation is cumbersome;

[0007] This aluminum liquid transfer flatbed trailer moves the ladle longitudinally along the longitudinal track to the low-pressure casting machine holding furnace that needs to be replenished with aluminum liquid. It is required that the low-pressure casting machine needs to be arranged according to the production line, and at the same time, a track foundation needs to be made, increasing the cost;

[0008] The aluminum liquid transfer system has a support platform on the flatbed trailer. The support platform can move laterally by a motor. The support platform has a tilting drive device, including a small gear on the tilting track and an outwardly protruding arc-shaped rack at the bottom of the ladle. The rack meshes with the small gear. This part is relatively complex to manufacture.

[0009] This aluminum liquid transfer system uses an N-type gate to press out aluminum liquid by operating and controlling it. For low-pressure casting pool-type holding furnaces, when there is a shortage of aluminum liquid, the N-type gate needs to be inserted below the liquid surface due to the restriction of the furnace door. This requires it to be inserted close to the center of the furnace, making it difficult to adjust the displacement and tilt of the ladle. Summary of the Invention

[0010] The purpose of this invention is to provide a low-pressure casting pool-type holding furnace aluminum liquid conveying device and method, which solves the problems of excessive aluminum liquid oxide slag, aluminum liquid air absorption affecting casting quality, and unsafe close-range operation by personnel caused by existing transfer devices.

[0011] This invention is achieved through the following technical solution:

[0012] This invention discloses an aluminum liquid conveying device for a low-pressure casting pool-type holding furnace, including an external furnace pipe, an internal furnace pipe, a furnace door, and a handle;

[0013] The external furnace pipe has an inverted U-shaped structure. The front end of the external furnace pipe is inserted into the aluminum liquid transfer device, serving as the suction end for conveying aluminum liquid to the low-pressure casting pool-type holding furnace. The end of the external furnace pipe is connected to the internal furnace pipe, and the end of the internal furnace pipe extends into the low-pressure casting pool-type holding furnace.

[0014] The internal pipes are inclined, with the ends facing the bottom of the low-pressure casting pool-type holding furnace. The end port serves as the outlet for conveying molten aluminum to the low-pressure casting pool-type holding furnace.

[0015] Furthermore, the end face of the pipe inside the furnace is parallel to the horizontal plane.

[0016] Furthermore, the furnace door has through holes that match the internal pipes and are sealed together.

[0017] The inner surface of the furnace door is prefabricated with a surrounding wall structure, and the furnace door is fitted onto the outside of the furnace nozzle of the low-pressure casting pool-type heat preservation furnace through the surrounding wall structure.

[0018] A handle is provided on the outside of the furnace door.

[0019] Furthermore, the furnace door structure of the low-pressure casting pool-type holding furnace is equipped with a furnace door locking device, which is used to lock the furnace door by pressing against the middle of the handle on the outside of the furnace door of the aluminum liquid conveying device.

[0020] Furthermore, perforated asbestos boards were placed inside the wall structure.

[0021] Furthermore, both the external and internal furnace pipes consist of sequentially connected metal pipes, insulation layers, and refractory layers from the outside in.

[0022] Furthermore, the upper surface of the furnace body of the low-pressure casting pool-type holding furnace is provided with a liquid riser port;

[0023] When metal mold casting is opened and castings are removed, or when the low-pressure casting work platform is lifted away from the sand casting sand box, or before a new mold is installed, a sealing structure is provided on the liquid riser port, which consists of an asbestos pad and an iron plate.

[0024] The present invention also discloses a method for conveying molten aluminum in the aforementioned low-pressure casting pool-type holding furnace molten aluminum conveying device, comprising the following steps:

[0025] Place the aluminum liquid transfer device containing the aluminum liquid below the front port of the external pipeline, and set the parameters in the parameter setting interface of the low-pressure casting machine control cabinet of the low-pressure casting pool-type holding furnace.

[0026] The pressurization and filling process begins, and the holding pressure is greater than the pressure at the highest height of the aluminum liquid conveying pipeline to the low-pressure casting tank-type holding furnace. During the holding time, the liquid level of the aluminum liquid in the low-pressure casting tank-type holding furnace is higher than the end face of the pipeline inside the furnace.

[0027] When molten aluminum is discharged from the external pipeline, during the pressure holding time, the molten aluminum transfer device is raised until the bottom of the molten aluminum transfer device is higher than the lower edge of the furnace nozzle, and the external pipeline of the molten aluminum conveying device of the low-pressure casting pool-type holding furnace extends into the inner cavity of the molten aluminum transfer device 10-20mm from the bottom.

[0028] After the pressure holding period ends, the pressure release stage begins, and the low-pressure casting pool-type holding furnace automatically performs the venting operation.

[0029] Under the pressure head formed by the height difference between the aluminum liquid transfer device and the aluminum liquid level in the low-pressure casting pool-type holding furnace, the aluminum liquid is automatically drawn into the low-pressure casting pool-type holding furnace, realizing the aluminum liquid transportation.

[0030] Furthermore, for low-pressure casting of metal molds, the operation process is divided into the following situations: A mold opening mechanism frame and a low-pressure casting working platform are provided above the low-pressure casting tank-type holding furnace; a mold opening mechanism frame and a low-pressure casting working platform are provided above the low-pressure casting tank-type holding furnace.

[0031] 1. It has a mold opening mechanism frame and a low-pressure casting work platform.

[0032] A. If the low-pressure casting tank furnace needs to be fed during the production process, but the mold has already been opened and the casting has been taken out, and the liquid riser of the low-pressure casting furnace is in an open state, in this case, the lower mold screws of the mold must be removed first, the mold as a whole should be closed and connected together, and the low-pressure casting motorized template should be raised to lift the mold.

[0033] Then, a sealing structure is reinstalled on the riser pipe of the low-pressure casting holding furnace;

[0034] Finally, the low-pressure casting motorized template is lowered to compact the sealing structure and complete the sealing of the liquid riser inlet of the low-pressure casting holding furnace.

[0035] B. If it is necessary to install a new mold and add material, the liquid riser of the low-pressure casting holding furnace is in an open state before the mold is installed. In this case, the new mold is first installed on the low-pressure casting motorized template, and the low-pressure casting motorized template is raised to lift the new mold.

[0036] Then, a sealing structure is reinstalled on the riser pipe of the low-pressure casting holding furnace;

[0037] Finally, the low-pressure casting motorized template is lowered to compact the sealing structure and complete the sealing of the liquid riser inlet of the low-pressure casting holding furnace.

[0038] II. No mold opening frame but has a mold opening mechanism and a low-pressure casting work platform

[0039] When a low-pressure casting tank-type holding furnace needs to be filled, but the mold has already been opened or the casting has been removed, the riser pipe of the low-pressure casting holding furnace is in an open state. In this case, first remove the lower mold screws and lift the lower mold away; then re-place the sealing structure on the riser pipe of the low-pressure casting holding furnace; lift a heavy object or mold to compact the sealing structure and complete the sealing of the riser pipe of the low-pressure casting holding furnace.

[0040] If it is necessary to install a new mold and add material, before installing the mold, re-place the sealing structure on the liquid riser of the low-pressure casting holding furnace; lift the heavy object or the mold to compact the sealing structure and complete the sealing of the liquid riser of the low-pressure casting holding furnace.

[0041] Furthermore, for the sand casting process, there is no mold opening mechanism or structure on the low-pressure casting work platform. If the sand box has been lifted off the low-pressure casting work platform before feeding, the liquid riser of the low-pressure casting holding furnace is in an open state. In this case, a sealing structure is re-placed on the liquid riser of the low-pressure casting holding furnace; a heavy object or mold is lifted to compact the sealing structure and complete the sealing of the liquid riser of the low-pressure casting holding furnace.

[0042] Compared with the prior art, the present invention has the following beneficial technical effects:

[0043] This invention discloses an aluminum molten material conveying device for a low-pressure casting pool-type holding furnace, comprising an external furnace pipe, an internal furnace pipe, a furnace door, and a handle. The external furnace pipe has an inverted U-shaped structure, with its front end inserted into the aluminum molten material transfer device and its end connected to the internal furnace pipe. The end of the internal furnace pipe extends into the low-pressure casting pool-type holding furnace. Compared to existing patented sealed aluminum transfer packages, operating control with an n-type gate that extends below the aluminum molten material, introduces gas, and presses out the aluminum molten material, this patented device has a simpler structure, making it easier to manufacture and maintain. Under the pressure head formed by the height difference between the aluminum molten material transfer device and the aluminum molten material level in the low-pressure casting pool-type holding furnace, the aluminum molten material in the aluminum molten material transfer device is automatically drawn into the aluminum molten material level below the level in the low-pressure casting pool-type holding furnace. This avoids the aluminum molten material oxidation caused by splashing, tumbling, and turbulence when directly poured into the low-pressure casting pool-type holding furnace, which wastes aluminum molten material and increases slag removal work. Furthermore, during the pouring process, the aluminum molten material reacts with air, causing aluminum molten material to absorb air, which can easily lead to pinhole problems in the castings. This invention enables continuous transfer of molten aluminum into a low-pressure casting furnace via an aluminum molten transfer device, eliminating the need for frequent loading and unloading of the top cover and simplifying operation.

[0044] Furthermore, the furnace door of the aluminum liquid conveying device has an opening, and the through hole matches the pipeline inside the furnace and is sealed together. The inner surface of the furnace door has a prefabricated wall structure, and a perforated asbestos board is placed inside the wall structure, which matches the existing furnace nozzle well. This ensures that the pipeline inside the furnace extends into the middle of the bottom of the heat preservation furnace and that the furnace door is sealed. The structure is simple and easy to operate and maintain.

[0045] The furnace door is equipped with a handle structure on the outside, which can be used to lock and fix the device using the existing low-pressure casting machine locking device, making it convenient to operate.

[0046] Furthermore, the pipeline of the aluminum liquid conveying device consists of a metal pipe, an insulation layer, and a refractory layer connected in sequence from the outside to the inside. The outer metal pipe serves as a skeleton, mainly playing the roles of load-bearing, support, and sealing; the middle insulation layer mainly reduces heat loss of aluminum liquid flowing through the pipeline; and the inner refractory layer is used to contact the aluminum liquid and plays the role of high temperature resistance.

[0047] This invention also discloses a method for conveying molten aluminum in the low-pressure casting pool-type holding furnace molten aluminum conveying device. The molten aluminum transfer device, containing molten aluminum, is placed below the furnace external pipe port of the molten aluminum conveying device. Pressure parameters are set through the low-pressure casting equipment control cabinet, and pouring begins. The remaining aluminum in the low-pressure casting furnace is forced out through the device of this invention, resulting in gas venting from the device. During the pressure holding time, the molten aluminum transfer device is raised above the furnace nozzle of the pool-type low-pressure casting holding furnace, and the furnace external pipe of the low-pressure casting pool-type holding furnace molten aluminum conveying device extends into the inner cavity of the molten aluminum transfer device from a distance of 10-20 mm from the bottom. After the pressure holding period, the pressure relief stage begins. The low-pressure casting holding furnace automatically vents air. Under the pressure head created by the height difference between the aluminum liquid transfer device and the aluminum liquid level in the low-pressure casting pool-type holding furnace, the aluminum liquid in the aluminum liquid transfer device is automatically drawn below the aluminum liquid level in the low-pressure casting pool-type holding furnace. This avoids the aluminum liquid oxidation caused by splashing, tumbling, and turbulence when directly pouring aluminum liquid into the low-pressure casting pool-type holding furnace, which wastes aluminum liquid, increases slag removal work, and causes aluminum liquid to absorb air during the pouring process, easily leading to pinhole problems in the castings. This invention can continuously transport aluminum liquid from the aluminum liquid transfer device into the low-pressure casting furnace without frequent loading and unloading of the top cover, making operation convenient. Existing patents involve introducing gas into a sealed aluminum transfer ladle to force aluminum into a low-pressure casting tank-type holding furnace. This requires pouring molten aluminum into the ladle first. During this pouring process, the molten aluminum tumbles, causing oxidation and gas absorption, thus reducing the quality of the molten aluminum. The system uses compressed gas to force the aluminum out; therefore, when transferring the second ladle, molten aluminum needs to be added, requiring the top cover to be opened for feeding, and the furnace cover needs to be sealed afterward, making the operation cumbersome. Furthermore, this aluminum transfer system uses an N-type gate, which extends below the molten aluminum to force it out. However, due to the furnace door's limitation, the N-type gate needs to be inserted below the liquid surface, requiring it to be near the center of the furnace, making ladle displacement and tilt adjustment difficult.

[0048] This invention utilizes the existing low-pressure casting machine control cabinet for gas discharge, simplifying the device.

[0049] Furthermore, in cases where low-pressure casting equipment needs to be shut down, the molten aluminum in the low-pressure casting holding furnace needs to be emptied. Manually scooping aluminum is not only unsafe but also labor-intensive. In such cases, an aluminum liquid conveying device can be used to pressurize the aluminum into a container to empty the molten aluminum in the low-pressure casting holding furnace. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the overall structure of an aluminum liquid conveying device for a low-pressure casting pool-type holding furnace according to the present invention.

[0051] Figure 2 This is a schematic diagram of the aluminum liquid conveying device;

[0052] Figure 3A schematic diagram of the pipeline structure for an aluminum liquid conveying device;

[0053] Figure 4 This is a schematic diagram of the perforated furnace cover of the present invention;

[0054] Figure 5 This is a schematic diagram of a low-pressure casting pool-type holding furnace with a mold opening mechanism frame.

[0055] The components include: 1. Aluminum liquid transfer device; 2. Aluminum liquid conveying device; 3. Low-pressure casting tank-type holding furnace; 4. Liquid riser pipe; 5. Low-pressure casting machine control cabinet; 7. Iron plate;

[0056] 21. External furnace piping; 22. Internal furnace piping; 23. Refractory layer; 24. Insulation layer; 25. Metal pipe;

[0057] 31. Furnace door; 32. Furnace door locking device; 33. Handle;

[0058] 61. Low-pressure casting motorized template; 62. Upper mold; 63. Lower mold; 64. Low-pressure casting working platform. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the present invention clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention; that is, the described embodiments are only a part of the embodiments of the present invention, and not all of them.

[0060] The components described and illustrated in the accompanying drawings and embodiments of this invention can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the invention provided in the following drawings is not intended to limit the scope of the claimed invention, but merely to illustrate one selected embodiment of the invention. All other embodiments obtained by those skilled in the art based on the accompanying drawings and embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0061] It should be noted that the terms “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that a process, element, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to the process, element, method, article, or apparatus.

[0062] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0063] Following the above technical solutions, such as Figure 1 and Figure 2As shown, this invention discloses an aluminum molten material conveying device for a low-pressure casting pool-type holding furnace, including an external furnace pipe 21, an internal furnace pipe 22, a furnace door 31, and a handle 33. The external furnace pipe 21 has an inverted U-shaped structure, with its front end extending into the aluminum molten material transfer device 1, 10-20 mm from the bottom of the inner cavity. The front end serves as the suction end for conveying aluminum molten material into the low-pressure casting pool-type holding furnace 3. The end end connects to the internal furnace pipe 22. The internal furnace pipe 22 is an inclined pipe, extending into the middle of the low-pressure casting pool-type holding furnace 3, 10-20 mm from the furnace bottom. The end face of the right end of the internal furnace pipe 22 is parallel to the horizontal plane, serving as the outlet end for conveying aluminum molten material into the low-pressure casting pool-type holding furnace 3.

[0064] like Figure 4 As shown, the furnace door 31 of the aluminum liquid conveying device has a hole in the middle and slightly above it, which matches the inner pipe 22 of the furnace and is sealed together; the upper and side edges of the furnace door 31 that mates with the nozzle of the low-pressure casting heat preservation furnace have a wall structure with a thickness of 5-10mm and a height of 3-10mm, which is used to mate with the nozzle, with a gap of 1-5mm; on the outside of the furnace door 31, there is a handle 33 in the middle of the furnace door 31 along the length direction, and the handle 33 is 20-40mm thick.

[0065] The furnace door structure of the low-pressure casting pool-type heat preservation furnace 3 is equipped with a furnace door locking device 32. The furnace door 31 can be locked and sealed by the screw of the existing low-pressure casting heat preservation furnace furnace door locking device 32 being pressed against the middle of the handle 33.

[0066] Cross-sectional schematic diagrams of external furnace pipe 21 and internal furnace pipe 22 are shown below. Figure 3 It consists of three layers, from the outside to the inside: a metal pipe 25, an insulation layer 24, and a fire-resistant layer 23. The outer metal pipe 25 serves as a framework, mainly playing a role in load-bearing, support, and sealing. The middle insulation layer 24 mainly reduces heat loss of molten aluminum flowing through the pipe. The inner fire-resistant layer 23 is used to contact the molten aluminum and plays a role in high-temperature resistance.

[0067] The working process of the aluminum liquid conveying device for the low-pressure casting pool-type holding furnace based on the present invention can be specifically divided into the following situations:

[0068] In the first scenario, during the filling stage of low-pressure casting, the gas in the metal mold cavity or sand mold cavity has been vented. After the casting solidifies and the pressure is released, if the casting is not removed from the metal mold or the sand box is not lifted off the low-pressure casting working platform 64, the riser pipe 4 of the low-pressure casting holding furnace is in a closed state. At this time, the furnace door 31 serves as the only channel connecting to the outside. In this case, the low-pressure casting furnace needs to be replenished with molten aluminum. The operation process is as follows:

[0069] 1. Prepare an alcohol-based paste coating with a Baumé degree of 40-60 by mixing alcohol with an alcohol-based paste coating. Apply the coating to the inner and outer walls and end faces of the parts of the aluminum liquid conveying device of the low-pressure casting pool-type holding furnace that come into contact with the aluminum liquid. Immediately after brushing, ignite the furnace. After brushing twice, place the furnace in a kiln at 100-150℃ and bake for 1-2 hours before use.

[0070] 2. Make a hole in the center of the asbestos board, with the hole diameter being the same as the outer diameter of the pipe 22 inside the furnace.

[0071] 3. Hoist the aluminum liquid conveying device that has been baked to the vicinity of the low-pressure casting tank-type holding furnace 3 that requires aluminum liquid conveying. Before installation, open the existing furnace door structure of the low-pressure casting tank-type holding furnace 3 and push it to one side. Then, put the perforated asbestos board on the furnace pipe 22 of the aluminum liquid conveying device and move it to the inside of the furnace door 31. Start hoisting the aluminum liquid conveying device into the low-pressure casting tank-type holding furnace 3. Lock it with the furnace door locking device 32 of the low-pressure casting holding furnace to complete the sealing of the furnace mouth of the low-pressure casting tank-type holding furnace 3.

[0072] 4. After the surface of the external pipeline 21 of the aluminum liquid conveying device 21 is prepared to be inserted into the aluminum liquid transfer device 1 and baked for 5-10 minutes, the aluminum liquid transfer device 1 is raised to a position within 20cm below the vertical pipeline on the left side of the aluminum liquid conveying device.

[0073] 5. Set the parameters in the parameter setting interface of the low-pressure casting machine control cabinet 5. The pressure parameter setting is divided into three stages: filling stage, holding stage, and depressurization stage. Start the equipment to pressurize according to the pressure curve. Once molten aluminum is discharged from the furnace pipe 22, immediately raise the molten aluminum transfer device 1 to a position where its bottom is higher than the furnace opening of the low-pressure casting holding furnace within the holding time. At the same time, ensure that the left vertical pipe end face of the molten aluminum transfer device is 10-20mm away from the bottom of the inner cavity of the molten aluminum transfer device 1.

[0074] The holding pressure should be greater than the pressure at which the molten aluminum is transported to the highest point of the molten aluminum conveying device. The holding pressure time should ensure that the liquid level in the low-pressure casting pool-type holding furnace 3 is higher than the bottom end face of the furnace pipe 22 within the holding pressure time.

[0075] 6. Once the pressure holding is completed and the pressure release stage begins, the low-pressure casting tank-type holding furnace 3 automatically performs a venting operation. Under the pressure head generated by the height difference between the liquid surface of the aluminum liquid transfer device 1 and the liquid surface of the aluminum liquid inside the furnace 3, the aluminum liquid in the aluminum liquid transfer device is drawn into the low-pressure casting tank-type holding furnace 3.

[0076] In the second scenario, for low-pressure casting of metal molds, a mold opening mechanism and a low-pressure casting work platform 64 are generally provided above the low-pressure casting tank-type holding furnace 3, such as... Figure 5As shown, the mold opening mechanism frame typically includes a template frame, a template, and a mold. The mold includes an upper mold 62 and a lower mold 63. The low-pressure casting pool-type holding furnace 3 does not have a mold opening mechanism frame above it, but it has a mold opening mechanism and a low-pressure casting working platform 64.

[0077] Specifically, this can be divided into two situations:

[0078] 1. It has a mold opening mechanism frame and a low-pressure casting work platform 64

[0079] If, during the production process, the low-pressure casting tank-type holding furnace 3 needs to be fed, but the mold has already been opened and the casting has been removed, and the riser pipe 4 of the low-pressure casting holding furnace is in an open state, then the screws of the lower mold 63 need to be removed first, and the upper mold 62 and lower mold 63 need to be closed. If the mold has four openings (top, bottom, left, and right), then the four openings should be closed together, and the upper mold 62 and lower mold 63 should be connected together with a connecting plate. The low-pressure casting motorized template 61 should be raised to lift the upper and lower molds 63. Then, the asbestos sealing ring should be replaced on the riser pipe of the low-pressure casting holding furnace, and an iron plate 7 with a thickness greater than or equal to 20mm and a size not less than 400×400mm should be pressed on. Then, the low-pressure casting motorized template 61 should be lowered to compact the iron plate 7, completing the sealing of the riser pipe 4 of the low-pressure casting holding furnace. Then, the steps in the first scenario should be followed.

[0080] If a new mold needs to be installed and materials need to be added, the riser pipe 4 of the low-pressure casting holding furnace is in an open state before the mold is installed. In this case, the new mold is first installed on the upper mold 62, and the low-pressure casting motorized template 61 is raised to lift the new mold. Then, the asbestos sealing ring is reinstalled on the riser pipe of the low-pressure casting holding furnace, and an iron plate 7 with a thickness of ≥20mm and a size of ≥400×400mm is pressed on. Then, the low-pressure casting motorized template 61 is lowered to press the iron plate 7 firmly, thus sealing the riser pipe 4 of the low-pressure casting holding furnace. Then, the steps in the first case are performed.

[0081] II. No mold opening frame but has a mold opening mechanism and a low-pressure casting work platform 64

[0082] The low-pressure casting pool-type holding furnace 3 needs to be fed, but at this time the mold has been opened and the casting has been taken out. The liquid riser 4 of the low-pressure casting holding furnace is in an open state. In this case, the screws of the lower mold 63 need to be removed first, and the lower mold 63 needs to be lifted away. Then, the asbestos pad and iron plate 7 should be placed on the liquid riser 4 of the low-pressure casting holding furnace. The heavy object or mold should be lifted to press the iron plate 7 to seal the liquid riser 4 of the low-pressure casting holding furnace. Then, the operation should be carried out according to the steps in the first case.

[0083] If it is necessary to install a new mold and add material, before installing the mold, re-place the asbestos pad and iron plate 7 on the liquid riser 4 of the low-pressure casting holding furnace; lift the heavy object or mold, press the iron plate 7 firmly, and complete the sealing of the liquid riser 4 of the low-pressure casting holding furnace. Then, follow the steps in the first case.

[0084] In the third scenario, for the sand casting low-pressure process, there is no mold opening mechanism on the low-pressure casting work platform 64. If the sand box has been lifted off the low-pressure casting work platform 64 before adding material, the liquid riser 4 of the low-pressure casting holding furnace is in an open state. In this case, an asbestos pad is placed on the liquid riser 4 of the low-pressure casting holding furnace, and an iron plate 7 with a thickness of ≥20mm and a size of ≥400×400mm is pressed on top. A heavy object or mold (weighing more than 1t) is lifted to press the iron plate 7 firmly, thus sealing the liquid riser 4 of the low-pressure casting holding furnace. Then, the steps in the first scenario are followed.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for conveying molten aluminum in a low-pressure casting tank-type holding furnace, characterized in that, The aluminum liquid conveying device for the low-pressure casting pool-type holding furnace includes an external furnace pipe (21), an internal furnace pipe (22), a furnace door (31), and a handle (33). The external pipeline (21) has an inverted U-shaped structure. The front end of the external pipeline (21) is inserted into the aluminum liquid transfer device (1) as the suction end for conveying aluminum liquid to the low-pressure casting pool type heat preservation furnace (3). The end is connected to the internal pipeline (22). The end of the internal pipeline (22) extends into the low-pressure casting pool type heat preservation furnace (3). The in-furnace pipe (22) is an inclined pipe with its end facing the bottom of the low-pressure casting pool type holding furnace (3). The end port serves as the outlet for conveying molten aluminum to the low-pressure casting pool type holding furnace (3). The upper surface of the furnace body of the low-pressure casting pool-type heat preservation furnace (3) is provided with a liquid riser port (4). When the casting is removed from the metal mold or the low-pressure casting work platform (64) is lifted away from the sand casting sand box, or before a new mold is installed, a sealing structure is provided on the liquid riser (4), which consists of an asbestos pad and an iron plate (7). The aluminum molten material transportation method includes the following process: Place the aluminum liquid transfer device (1) containing aluminum liquid below the front port of the external pipeline (21), and set the parameters in the parameter setting interface of the low-pressure casting machine control cabinet (5) of the low-pressure casting pool type heat preservation furnace (3). The pressurization process begins, and the holding pressure is greater than the pressure at the highest height of the aluminum liquid conveying pipeline to the low-pressure casting pool-type holding furnace (3). During the holding time, the liquid level of the aluminum liquid in the low-pressure casting pool-type holding furnace (3) is higher than the end face of the furnace pipeline (22). When aluminum liquid is discharged from the external pipeline (21), during the pressure holding time, the aluminum liquid transfer device (1) is raised until the bottom of the aluminum liquid transfer device (1) is higher than the lower edge of the furnace nozzle, and the external pipeline (21) of the aluminum liquid conveying device of the low pressure casting pool type heat preservation furnace extends into the inner cavity of the aluminum liquid transfer device (1) 10-20mm from the bottom. After the pressure holding is completed, the pressure release stage begins, and the low-pressure casting pool-type heat-holding furnace (3) automatically performs the venting operation; Under the pressure head formed by the height difference between the aluminum liquid level in the aluminum liquid transfer device (1) and the low-pressure casting pool-type heat preservation furnace (3), the aluminum liquid is automatically sucked into the low-pressure casting pool-type heat preservation furnace (3) to realize the aluminum liquid transportation.

2. The aluminum liquid conveying method according to claim 1, characterized in that, The end face of the pipe (22) inside the furnace is parallel to the horizontal plane.

3. The aluminum liquid conveying method according to claim 1, characterized in that, The furnace door (31) has a through hole that matches the internal pipe (22) and is sealed. The inner surface of the furnace door (31) is prefabricated with a wall structure, and the furnace door (31) is fitted onto the outside of the furnace nozzle of the low-pressure casting pool-type heat preservation furnace (3) through the wall structure; A handle (33) is provided on the outside of the furnace door (31).

4. The aluminum liquid conveying method according to claim 3, characterized in that, The furnace door structure of the low-pressure casting pool-type heat preservation furnace (3) is equipped with a furnace door locking device (32). The furnace door locking device (32) is used to lock the furnace door (31) by pressing against the middle of the handle (33) on the outside of the furnace door (31) of the aluminum liquid conveying device.

5. The aluminum liquid conveying method according to claim 3, characterized in that, Perforated asbestos boards are placed inside the wall structure of the furnace door (31).

6. The aluminum liquid conveying method according to claim 1, characterized in that, Both the external furnace pipe (21) and the internal furnace pipe (22) consist of a metal pipe (25), an insulation layer (24), and a refractory layer (23) connected in sequence from the outside to the inside.

7. The aluminum molten metal conveying method according to claim 1, characterized in that, For low-pressure casting of metal molds, a mold opening mechanism frame and a low-pressure casting working platform (64) are provided above the low-pressure casting pool-type holding furnace (3), and there is no mold opening mechanism frame above the low-pressure casting pool-type holding furnace (3) but there is a mold opening mechanism and a low-pressure casting working platform (64). The operation process is divided into the following situations:

1. It has a mold opening mechanism frame and a low-pressure casting work platform (64) A. If the low-pressure casting pool-type heat preservation furnace (3) needs to be fed during the production process, and the mold has already been opened, the liquid riser (4) of the low-pressure casting heat preservation furnace is in an open state. In this case, the screws of the lower mold (63) of the mold should be removed first, the mold should be closed and connected together, and the low-pressure casting motorized template (61) should be raised to lift the mold. Then, a sealing structure is re-placed on the liquid riser (4) of the low-pressure casting holding furnace; Finally, the low-pressure casting motorized template (61) is lowered to compact the sealing structure and complete the sealing of the liquid riser (4) of the low-pressure casting heat preservation furnace. Then, the operation is carried out according to the steps in claim 1. B. If it is necessary to install a new mold and add material, before installing the mold, the liquid riser port (4) of the low-pressure casting heat preservation furnace is in an open state. In this case, the new mold is first installed on the low-pressure casting motorized template (61), and the low-pressure casting motorized template (61) is raised to lift the new mold. Then, a sealing structure is re-placed on the liquid riser (4) of the low-pressure casting holding furnace; Finally, the low-pressure casting motorized template (61) is lowered to compact the sealing structure and complete the sealing of the liquid riser (4) of the low-pressure casting heat preservation furnace. Then, the operation is carried out according to the steps in claim 1. II. No mold opening mechanism frame but has a mold opening mechanism and a low-pressure casting work platform (64) The low-pressure casting pool-type heat preservation furnace (3) needs to be filled with material. At this time, the mold has been opened and the liquid riser (4) of the low-pressure casting heat preservation furnace is in an open state. In this case, first remove the screws of the lower mold (63) and lift the lower mold (63); then re-place the sealing structure on the liquid riser (4) of the low-pressure casting heat preservation furnace; lift the heavy object to compact the sealing structure and complete the sealing of the liquid riser (4) of the low-pressure casting heat preservation furnace. Then, operate according to the steps in claim 1. If it is necessary to install a new mold and add material, before installing the mold, re-place the sealing structure on the liquid riser (4) of the low-pressure casting heat preservation furnace; lift the heavy object to compact the sealing structure and complete the sealing of the liquid riser (4) of the low-pressure casting heat preservation furnace, and then operate according to the steps in claim 1.

8. The aluminum liquid conveying method according to claim 1, characterized in that, For sand casting low-pressure casting process, there is no mold opening mechanism frame on the low-pressure casting work platform (64). If the sand box has been lifted off the low-pressure casting work platform (64) before the material is added, the liquid riser (4) of the low-pressure casting heat preservation furnace is in an open state. In this case, a sealing structure is placed on the liquid riser (4) of the low-pressure casting heat preservation furnace; a heavy object is lifted to compact the sealing structure and complete the sealing of the liquid riser (4) of the low-pressure casting heat preservation furnace. Then, the operation is carried out according to the steps in claim 1.

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