Low-pressure casting pouring system for large-scale long-lead aluminum alloy column body

Abstract

The invention discloses a low-pressure casting pouring system for a large long-lead aluminum alloy column. A mold filling mode adopted by the pouring system is a stand column gap type structure. The pouring system comprises a heat preservation riser, a gap type inner pouring gate, a casting mold, a stand column type straight pouring gate, a chilling block, a first trapezoid transverse pouring gate, a second trapezoid transverse pouring gate, a columnar liquid rising pipe, a casting mold top, a casting mold bottom, a sand core, a reinforcing rib, a sand core tail and a sand core head. According to the pouring system, the problems of unstable mold filling, sand washing, slag inclusion defects and the like of a large complex cylinder are solved; the gap type flow gate can be used for better feeding the position of a casting with larger wall thickness difference, and the problem that the top of the casting is difficult to feed due to overlarge height of the casting is solved; the pouring system disclosed by the invention is beneficial to realizing uniform cooling and sequential solidification of castings, reduces the generation of internal shrinkage porosity and shrinkage cavity defects, and reduces the porosity compared with a traditional pouring system.

Description

Technical Field

[0001] The invention relates to the technical field of low-pressure casting, in particular to a low-pressure casting pouring system for a large-scale long-lead aluminum alloy column. Background Art

[0002] With the development of industrial automation and intelligent manufacturing, long-lead mechanical transmission components generally require high quality and stability in casting production. Therefore, research is needed to improve the casting performance of complex transmission components. For complex and special-shaped equipment, low-pressure casting remains the main technology for high-quality production.

[0003] The traditional slot-type pouring system has a less significant effect on the diversion of molten metal, which impacts the mold. The pouring system also has a poor ability to compensate for shrinkage at the top of the casting. After casting, due to the limitations of the pouring system, the casting often suffers from shrinkage defects such as shrinkage cavities and porosity. Therefore, the novel column-type slot-type pouring system of the present invention can alleviate the impact of molten metal, making the filling of the mold more stable, effectively compensate for the shrinkage of the gate at the top of the casting, and is provided with an insulating riser to improve the yield rate of casting production, thereby solving the technical problems faced by traditional pouring systems. Summary of the Invention

[0004] The purpose of the present invention is to provide a low-pressure casting pouring system for large long-lead aluminum alloy columns to solve the problems raised in the above-mentioned background technology. The main purpose of the present invention is to design a pouring system to ensure the sequential solidification of the casting, so that the pouring system can effectively compensate for the larger hot spots in the casting and reduce shrinkage defects such as shrinkage cavities and porosity.

[0005] To achieve the above objectives, the present invention provides the following technical solutions: a low-pressure casting pouring system for a large, long-lead aluminum alloy column, wherein the pouring system adopts a column-slit structure as the filling method; the pouring system includes an insulating riser, a slot-type ingode, a casting mold, a column-type straight sprue, a chiller, a first trapezoidal runner, a second trapezoidal runner, a columnar riser, a mold top, a mold bottom, a sand core, reinforcing ribs, a sand core tail, and a sand core head;

[0006] The lower end of the thermal insulation riser is connected with the upper end of the column type straight runner, the left end of the slot type endocastor is connected with the right end of the column type straight runner, and is connected with the left end of the casting mold, the lower end of the column type straight runner is connected with the upper ends of the first trapezoidal cross runner and the second trapezoidal cross runner; the inner wall of the cold iron is connected with the outer wall of the casting mold, the first trapezoidal cross runner and the second trapezoidal cross runner are connected in a cross shape, and the lower end of the cross intersection of the first trapezoidal cross runner and the second trapezoidal cross runner is directly connected to the upper end of the columnar riser pipe, the hole grooves at the top and bottom of the mold cooperate with the tail and head of the sand core respectively, and the six reinforcing ribs of the sand core cooperate with the reinforcing rib grooves of the casting mold.

[0007] Preferably, four of the thermal insulation risers, slot-type ingrowns, and column-type straight runners are evenly and symmetrically arranged around the central axis of the casting mold.

[0008] Preferably, the chillers are evenly and symmetrically arranged in four rows around the central axis of the casting mold and located between adjacent column-type sprues, with seven chillers arranged in each row.

[0009] Preferably, the lower ends of the four column-type sprues are connected to the upper ends of the first trapezoidal runner and the second trapezoidal runner, and the upper ends of the four column-type sprues are respectively connected to the lower ends of the four insulation risers.

[0010] Preferably, the slot-type ingrown runner is arranged at a location where the wall thickness of a large long-lead aluminum alloy cylinder is uneven and the thermal node is large.

[0011] Preferably, the insulating riser is arranged to ensure that the column-type sprue solidifies later, so as to ensure that the entire casting process achieves sequential solidification.

[0012] Preferably, the first trapezoidal runner, the second trapezoidal runner and the column type straight runner are arranged to ensure the minimum volume to improve the casting yield.

[0013] The low-pressure casting system for a large, long-lead aluminum alloy column proposed in the present invention has the following beneficial effects:

[0014] 1. The pouring system of the present invention solves the problems of unstable filling, sand washing and slag inclusion defects for large and complex columns;

[0015] 2. The slot-type ingate of the present invention can better feed the shrinkage of the parts with large differences in wall thickness, and solve the problem that the top of the casting is difficult to feed due to the excessive height of the casting;

[0016] 3. The pouring system of the present invention helps to achieve uniform cooling and sequential solidification of the casting, reduces the occurrence of internal shrinkage defects, and reduces porosity compared to traditional pouring systems;

[0017] 4. Compared with the traditional pouring system, the heat-insulating riser in the pouring system of the present invention can increase the yield rate of castings and reduce excessive consumption of molten metal in order to delay the solidification time and increase the cross-sectional size of the pouring channel;

[0018] 5. Compared with the traditional gating system, the gating system of the present invention further improves the quality of castings, refines the grain structure of castings, and obtains castings with dense structure and high mechanical properties;

[0019] 6. The pouring system of the present invention can realize castings of different sizes but similar geometric shapes by changing the number of column sprues and the cross-sectional size of the ingates. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a front view of the overall structure of the low-pressure pouring system of the present invention;

[0021] Figure 2 Schematic cross-sectional view of the low-pressure pouring system of the present invention;

[0022] Figure 3 A schematic diagram of a sand core of a low-pressure pouring system according to the present invention;

[0023] Figure 4 A comparison chart of the metal liquid flow rates of the present invention and the traditional pouring system;

[0024] Figure 5 A comparison chart of the porosity of the present invention and the traditional pouring system;

[0025] Figure 6 This is a comparison chart of the solid phase fraction simulation between the present invention and the traditional gating system;

[0026] Figure 7 The figure is a comparison of the metallographic microstructures of castings produced by the present invention and the traditional pouring system.

[0027] In the figure: 1. Insulated riser; 2. Slit-type sprue; 3. Casting mold; 4. Column-type straight runner; 5. Chill; 6a. First trapezoidal runner; 6b. Second trapezoidal runner; 7. Columnar riser; 8. Top of mold; 9. Bottom of mold; 10. Sand core; 11. Reinforcement rib; 12. Sand core tail; 13. Sand core head. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] See also Figure 1-7 The present invention provides a technical solution: a low-pressure casting pouring system for a large long-lead aluminum alloy column, wherein the structural dimensions of the large long-lead aluminum alloy column are as follows: the maximum wall thickness is 110 mm, the average wall thickness is 54 mm, the casting height is 800 mm, and the casting has six reinforcing ribs inside the aluminum alloy column, including a heat-insulating riser 1, a slot-type lining runner 2, a casting mold 3, a columnar straight runner 4, a chiller 5, a first trapezoidal runner 6a, a second trapezoidal runner 6b, a columnar riser 7, and a mold top. 8, mold bottom 9, sand core 10, reinforcement rib 11, sand core tail 12, sand core head 13 and other parts; the lower end of the insulation riser 1 is directly connected to the upper end of the column type straight runner 4; the left end of the slot type ingrown 2 is connected to the right end of the column type straight runner 4, and is connected to the left end of the casting mold 3. The insulation riser 1, slot type ingrown 2, and column type straight runner 4 are evenly and symmetrically arranged around the central axis of the casting mold 3. The insulation riser 1 is set to ensure that the column type straight runner 4 solidifies later Solid, to ensure that the overall casting process achieves sequential solidification, the lower end of the column type sprue 4 is connected to the upper end of the first trapezoidal runner 6a and the second trapezoidal runner 6b; the inner wall of the chiller 5 is connected to the outer wall of the casting mold 3; the chiller 5 is evenly and symmetrically arranged in four rows around the central axis of the casting mold 3 and is located between adjacent column type sprues 4, with seven chillers 5 in each row, the trapezoidal runner 6a is connected to the trapezoidal runner 6b in a cross shape, and the lower ends of the four column type sprues 4 are connected to the The upper ends of the first trapezoidal cross runner 6a and the second trapezoidal cross runner 6b are connected, the upper ends of the four column-type straight runners 4 are respectively connected to the lower ends of the four thermal insulation risers 1, and the lower end of the cross intersection of the first trapezoidal cross runner 6a and the second trapezoidal cross runner 6b is directly connected to the upper end of the cylindrical riser tube 7; the hole grooves of the top 8 and the bottom 9 of the mold respectively cooperate with the sand core tail 12 and the sand core head 13; the six reinforcing ribs 11 of the sand core 10 cooperate with the reinforcing rib 11 grooves of the casting mold 3.

[0030] According to an embodiment of the present invention, Figure 1 As shown, molten metal enters trapezoidal runners 6a and 6b through cylindrical riser tubes 7. To ensure smooth flow and filling within the trapezoidal runners 6a and 6b, they are arranged in a cross-shaped arrangement. The ends of the two trapezoidal runners 6a and 6b connect to a column-type sprue 4 and a slot-type ingode 2, respectively, to effectively compensate for ribs and uneven wall thicknesses. The slot-type ingode 2 is positioned within a large, long-lead aluminum alloy column where the wall thickness is uneven and a significant thermal junction is present.

[0031] According to an embodiment of the present invention, Figure 1As shown, after the molten metal is filled, the solidification rate of the column type straight runner 4 is delayed by setting the heat preservation riser 1, instead of delaying the solidification rate by increasing the volume size of the column type straight runner 4, so as to increase the overall casting yield.

[0032] According to an embodiment of the present invention, Figure 4 As shown in the figure, the numerical simulation of the flow field shows that compared with the traditional pouring system, the molten metal flows more smoothly when entering the pouring system and the casting cavity from the riser, avoiding defects such as slag inclusion, air holes and air entrapment in the molten metal.

[0033] According to an embodiment of the present invention, Figure 5 As shown, compared with the traditional pouring system, the present invention can compensate for shrinkage on the top of the casting. The main shrinkage defects occur in the first trapezoidal runner 6a, the second trapezoidal runner 6b and the insulation riser 1, and there is no shrinkage defect in the casting as a whole.

[0034] According to an embodiment of the present invention, Figure 6 As shown in the figure, the solid phase fraction simulation results are shown. The results show that the pouring system of the present invention can achieve sequential solidification and effective shrinkage feeding of molten metal through the arrangement of chiller and insulation riser.

[0035] According to an embodiment of the present invention, Figure 7 As shown in the metallographic structure, the results show that the casting structure actually produced by the pouring system of the present invention is denser and the grains are finer.

[0036] The casting system is designed specifically for large, long-lead aluminum alloy columns and is carefully optimized for their specific structural dimensions and internal features (such as a maximum wall thickness of 110 mm, an average wall thickness of 54 mm, a height of 800 mm, and six internal reinforcing ribs). The system includes several key components, such as insulating risers, slot-type ingrowns, column-type straight sprues, chillers, trapezoidal cross runners, columnar riser tubes, and sand cores. These components work together to achieve smooth filling and sequential solidification of the molten metal, effectively reducing or eliminating various defects that may occur in the casting manufacturing process.

[0037] Key features and benefits include:

[0038] 1. Design of insulation riser and column type sprue: This design can slow down the solidification rate of the column type sprue, thereby ensuring that the casting can continue to receive sufficient metal supply during the solidification process and improve the quality of the casting.

[0039] 2. Cross-shaped combination of trapezoidal runners: ensures smoother flow of molten metal in the trapezoidal runners when filling the mold, reducing the risk of common casting defects such as metal splashing, slag inclusions, and air holes.

[0040] 3. Setting of slit-type ingrown gate: It is particularly suitable for areas with uneven wall thickness and large thermal nodes, and can effectively compensate for shrinkage.

[0041] 4. Flow field numerical simulation results: Compared with traditional pouring systems, this system can achieve a smoother flow of molten metal into the pouring system and casting cavity, significantly reducing casting defects.

[0042] 5. Top feeding capability: Compared with conventional systems, the present invention provides effective feeding capability at the top of the casting, further improving product quality.

[0043] In summary, the present invention provides a low-pressure casting system that effectively improves the quality of large, long-lead aluminum alloy cylindrical castings. Through a carefully designed pouring system and its components, smooth flow and sequential solidification of molten metal are achieved, common casting defects are significantly reduced, and the yield and quality of castings are improved. This is a significant technological advancement for the production of large aluminum alloy castings.

[0044] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A low-pressure casting pouring system for large-scale long-lead aluminum alloy columns, characterized in that: The pouring system adopts a column-slit structure as the filling method; the pouring system comprises a heat-insulating riser (1), a slot-type endocastor (2), a casting mold (3), a column-type straight runner (4), a chiller (5), a first trapezoidal cross runner (6a), a second trapezoidal cross runner (6b), a columnar riser (7), a mold top (8), a mold bottom (9), a sand core (10), a reinforcing rib (11), a sand core tail (12), and a sand core head (13); The lower end of the heat-insulating riser (1) is connected to the upper end of the column-type straight runner (4); the left end of the slot-type endocastor (2) is connected to the right end of the column-type straight runner (4) and is connected to the left end of the casting mold (3); the lower end of the column-type straight runner (4) is connected to the upper ends of the first trapezoidal cross runner (6a) and the second trapezoidal cross runner (6b); the inner wall of the chiller (5) is connected to the outer wall of the casting mold (3); the first trapezoidal cross runner (6 a) is connected to the second trapezoidal runner (6b) in a cross shape, the lower end of the cross intersection of the first trapezoidal runner (6a) and the second trapezoidal runner (6b) is directly connected to the upper end of the columnar riser (7), the holes and grooves at the top (8) and the bottom (9) of the mold are respectively matched with the sand core tail (12) and the sand core head (13), and the six reinforcing ribs (11) of the sand core (10) are matched with the reinforcing rib (11) through grooves of the casting mold (3).

2. A low-pressure casting pouring system for a large-scale long-lead aluminum alloy column according to claim 1, characterized in that: Four of the heat-insulating risers (1), the slot-type entrappers (2), and the column-type straight runners (4) are evenly and symmetrically arranged around the central axis of the casting mold (3).

3. A low pressure casting pouring system for a large long lead aluminum alloy column according to claim 2, characterized in that: The chillers (5) are evenly and symmetrically arranged in four rows around the central axis of the casting mold (3) and are located between adjacent column-type sprues (4), with seven chillers (5) arranged in each row.

4. A low-pressure casting pouring system for a large-scale long-lead aluminum alloy column according to claim 3, characterized in that: The lower ends of the four column-type sprues (4) are connected to the upper ends of the first trapezoidal runner (6a) and the second trapezoidal runner (6b), and the upper ends of the four column-type sprues (4) are respectively connected to the lower ends of the four thermal insulation risers (1).

5. A low pressure casting pouring system for a large long lead aluminum alloy column according to claim 4, characterized in that: The slit-type ingates (2) are arranged at a location where the wall thickness of a large-scale long-lead aluminum alloy column is uneven and the heat node is large.

6. A low pressure casting pouring system for a large long lead aluminum alloy column according to claim 5, characterized in that: The setting of the heat-insulating riser (1) is required to ensure that the column-type straight runner (4) solidifies later, thereby ensuring that the entire casting process achieves sequential solidification.

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