Tandem feeding process for thick-wall large cylinder type aluminum alloy sand mold casting parts

Abstract

The invention discloses a tandem feeding process for thick-wall large cylindrical aluminum alloy sand casting parts, and relates to the field of non-ferrous metal casting, and the tandem feeding process comprises the following steps: according to low-pressure pouring temperature field distribution, chillers are arranged on the peripheral side of a casting in a segmented manner, a plurality of feeding vertical cylinders are arranged along the height of the casting in a segmented manner, the chillers are covered by the feeding vertical cylinders, and the feeding vertical cylinders are arranged on the periphery of the casting in a segmented manner; feeding openings are evenly formed in the side wall of each section of feeding vertical cylinder in a surrounding mode, liquid adding pipes are evenly arranged on the peripheral side of the casting in the height direction and surround the feeding vertical cylinders, pouring gates are formed in the ends of the liquid adding pipes, and each liquid adding pipe communicates with the corresponding feeding opening in the same vertical line. High-temperature molten aluminum is added into the casting through a liquid adding pipe and a feeding opening for feeding; according to the method, shrinkage cavities in thick-wall large cylinder type aluminum alloy sand mold casting can be eliminated, an excellent compact structure of the whole casting is obtained, the technical requirement for X-ray flaw detection of type-II castings is met, and meanwhile the process yield is high.

Description

Technical Field

[0001] The invention relates to the technical field of nonferrous metal casting, and in particular to a tandem shrinkage feeding process for thick-walled large cylindrical aluminum alloy sand castings. Background Art

[0002] Large cylindrical aluminum alloy castings with an outer diameter greater than 650mm, a wall thickness greater than 40mm, and a length greater than 3500mm usually adopt a horizontal low-pressure pouring process. The workpiece is in a horizontal position, and a shrinkage feeding gate is set at the bottom along the entire length and a large riser is set at the top to achieve shrinkage feeding in the top and bottom areas. However, due to the large outer diameter and thick wall thickness, its shrinkage feeding channel cannot achieve full radial coverage, which makes it easy to form excessive shrinkage cavities or shrinkage defects in the side shrinkage blind area. It is difficult to meet the technical acceptance conditions for Class II castings with overall X-ray flaw detection requirements. Summary of the invention

[0003] In view of this, the object of the present invention is to provide a tandem shrinkage feeding process for thick-walled large cylindrical aluminum alloy sand castings.

[0004] The tandem shrinkage feeding process for thick-walled large cylindrical aluminum alloy sand castings provided by the present invention adopts the following technical scheme:

[0005] A tandem shrinkage feeding process for thick-walled large cylindrical aluminum alloy sand castings adopts the following method: chills are arranged in sections around the casting according to the temperature field distribution of low-pressure pouring, and multiple shrinkage feeding vertical cylinders are arranged in sections along the height of the casting, the shrinkage feeding vertical cylinders cover the chills, and shrinkage feeding ports are evenly arranged on the side walls of each section of the shrinkage feeding vertical cylinders. Liquid adding pipes are evenly arranged around the shrinkage feeding vertical cylinders along the height direction around the casting, and gates are arranged at the ends of the liquid adding pipes. Each of the liquid adding pipes is connected to the shrinkage feeding ports on the same vertical line, and high-temperature aluminum liquid is added to the casting through the shrinkage feeding ports through the liquid adding pipes for shrinkage feeding.

[0006] Furthermore, a liquid adding vertical cylinder for adding high-temperature aluminum liquid is installed on the shrinkage feeding port, and the liquid adding pipe is connected to the liquid adding vertical cylinder.

[0007] Furthermore, a gap communicating with the shrinkage feeding port is left between the chiller levels.

[0008] Furthermore, the thickness of the chill gradually becomes thinner along the flow direction of the aluminum liquid to form a gradient transition.

[0009] Furthermore, a cross runner is provided at the end of the liquid adding pipe, and the cross runner connects all the liquid adding pipes.

[0010] Furthermore, the runner is evenly provided with ingates.

[0011] In summary, the present invention has at least one of the following beneficial effects: it can achieve thick-walled large cylindrical aluminum alloy sand casting to eliminate shrinkage cavities and obtain excellent dense structure of the entire casting, meet the technical requirements of X-ray flaw detection of Class II castings, and have a high process yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic structural diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0013] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0014] The following is combined with Figure 1 The present invention is described in further detail.

[0015] The embodiment of the present invention discloses a tandem shrinkage feeding process for thick-walled large cylindrical aluminum alloy sand castings. Figure 1 The tandem shrinkage feeding process of thick-walled large cylindrical aluminum alloy sand castings adopts the following method: according to the temperature field distribution of low-pressure pouring, a chill 1 is arranged in sections around the casting, and a plurality of shrinkage feeding vertical tubes 2 are arranged in sections along the height of the casting. The effective shrinkage feeding distance of the shrinkage feeding vertical tubes 2 in the height direction covers the full height of the casting. The shrinkage feeding vertical tubes 2 cover the chill 1, and the side walls of each section of the shrinkage feeding vertical tubes 2 are uniformly surrounded by shrinkage feeding ports. The casting is uniformly surrounded by liquid adding pipes 4 along the height direction. The liquid adding pipes 4 are arranged around the shrinkage feeding vertical tubes 2. The end of the tube 4 is provided with a gate, and each of the liquid adding tubes 4 is connected to the shrinkage feeding port on the same vertical line to form a complete shrinkage feeding channel. The high-temperature aluminum liquid is added to the casting through the liquid adding tube 4 through the shrinkage feeding port for shrinkage feeding; a shrinkage feeding channel toward each shrinkage feeding column 2 is formed to achieve balanced solidification in the entire length direction and circumferential direction. The stepped gate introduces the high-temperature aluminum liquid into each shrinkage feeding column 2 to improve the shrinkage feeding effect, and can achieve thick-walled large cylindrical aluminum alloy sand casting to eliminate shrinkage cavities and obtain excellent dense structure of the entire casting. It meets the technical requirements of X-ray flaw detection of Class II castings and has a high process yield.

[0016] In this embodiment, a liquid adding column 3 for adding high-temperature aluminum liquid is installed on the feeding port, and the liquid adding pipe 4 is connected to the liquid adding column 3. The effective feeding distance of all the liquid adding columns 3 in the segment covers the inner circumference of the segment, and the liquid adding pipe 4, the liquid adding column 3 and the feeding port form a complete feeding channel.

[0017] In this embodiment, a gap communicating with the shrinkage-feeding port is left between the horizontal portions of the chiller 1 to facilitate high-temperature aluminum liquid to flow through the gap flow channel onto the casting.

[0018] In this embodiment, the thickness of the chill 1 gradually becomes thinner along the flow direction of the aluminum liquid to form a gradient transition. The temperature gradient of the low-pressure pouring of the sand mold is adjusted by cooperating with the inner diameter variable-section chill 1 and the outer diameter serial shrinkage feeding cylinder 2 to form a shrinkage feeding channel toward each shrinkage feeding cylinder 2, thereby achieving balanced solidification in the entire length direction and circumferential direction.

[0019] In this embodiment, a cross runner 5 is provided at the end of the liquid adding tube 4, and the cross runner 5 connects all the liquid adding tubes 4. The cross runner 5 is arranged in a ring shape. By adding high-temperature filtrate into the cross runner 5, the cross runner 5 can add high-temperature aluminum liquid into the liquid adding tube through the gate.

[0020] In this embodiment, the runner 5 is evenly provided with ingates 6 to fill the surface of the casting with high-temperature molten aluminum.

[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A tandem shrinkage feeding process for thick-walled large cylindrical aluminum alloy sand castings, characterized in that: The following method is adopted: chillers (1) are arranged in sections around the casting according to the temperature field distribution of low-pressure pouring, and multiple shrinkage-feeding vertical cylinders (2) are arranged in sections along the height of the casting, the shrinkage-feeding vertical cylinders (2) cover the chillers (1), and shrinkage-feeding ports are evenly arranged on the side walls of each section of the shrinkage-feeding vertical cylinder (2), and liquid adding pipes (4) are evenly arranged around the shrinkage-feeding vertical cylinder (2) along the height direction around the casting, and a pouring gate is arranged at the end of the liquid adding pipe (4), and each of the liquid adding pipes (4) is respectively connected to the shrinkage-feeding port on the same vertical line, and high-temperature aluminum liquid is added to the casting through the shrinkage-feeding port through the liquid adding pipe (4) to feed shrinkage.

2. The tandem shrinkage feeding process for thick-walled large cylindrical aluminum alloy sand castings according to claim 1, characterized in that: A liquid adding vertical cylinder (3) for adding high-temperature aluminum liquid is installed on the shrinkage feeding port, and the liquid adding pipe (4) is connected to the liquid adding vertical cylinder (3).

3. The tandem shrinkage feeding process for thick-walled large cylindrical aluminum alloy sand castings according to claim 1, characterized in that: A gap communicating with the shrinkage-feeding port is left between the horizontal sections of the cold iron (1).

4. The tandem shrinkage feeding process for thick-walled large cylindrical aluminum alloy sand castings according to claim 3, characterized in that: The thickness of the chill (1) gradually becomes thinner along the flow direction of the aluminum liquid to form a gradient transition.

5. The tandem shrinkage feeding process for thick-walled large cylindrical aluminum alloy sand castings according to claim 1, characterized in that: A cross runner (5) is provided at the end of the liquid adding pipe (4), and the cross runner (5) connects all the liquid adding pipes (4).

6. The tandem shrinkage feeding process for thick-walled large cylindrical aluminum alloy sand castings according to claim 5, characterized in that: Ingates (6) are evenly arranged on the runner (5).

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