An extension beam support casting process apparatus

Abstract

This invention relates to the field of extended beam support casting technology, and discloses an extended beam support casting process device including sand cores and a gating system, and an extended beam casting formed by the combination of molten iron poured through the self-gating system and the sand cores. Two sand cores are symmetrically distributed on both sides of the gating system. The bosses between the two sand cores are thick-walled areas, and the same side of the two sand cores is a thin-walled area. Each sand core includes a chill groove area and a support column cavity. The chill groove area is located in the thick-walled area of ​​the boss in the middle of the sand core, and the support column cavity vertically penetrates the thin-walled area. The groove depth of the chill groove area is 1.1-1.3 times the thickness of the chill, and the groove wall inclination angle is 5°-8°. This invention, by setting up sand cores, a gating system, support rods, and chills, ensures that the product is free of casting defects such as shrinkage cavities and that the shape does not warp, thus producing a stable and satisfactory product with high market application value.

Description

Technical Field

[0001] This invention relates to the field of casting technology for extension beam supports, and more particularly to a casting process apparatus for extension beam supports. Background Technology

[0002] Extended beam supports are castings used in engineering structures (such as buildings and heavy-duty vehicle suspension systems) to provide extended support. They typically feature cantilever structures and alternating thin and thick walls, and are widely used in heavy machinery, bridge engineering, and special vehicles. Sand core casting was chosen as its production method primarily due to the structural complexity of the castings and the stringent requirements for defect control.

[0003] Extended beam supports typically have the following structural features:

[0004] Thin-walled high cantilever supports have cantilever structures at the top and bottom. The walls are thin (usually ≤8mm) and the height is large (≥150mm), making them prone to warping and deformation due to uneven stress during the casting process.

[0005] Thick-walled isolated bosses: Thick-walled bosses (wall thickness ≥ 30 mm) exist in the middle or around the perimeter. Due to their isolated position, they are prone to forming hot spots, which can lead to shrinkage defects.

[0006] To ensure the quality of the extension beam support, a casting process device for the extension beam support is proposed, combining sand core casting technology, to solve the problems existing in the manufacturing process of the extension beam support. Summary of the Invention

[0007] To address the technical problems mentioned in the background art, the present invention provides a casting process apparatus for an extension beam support.

[0008] This invention is achieved using the following technical solution: a casting process apparatus for an extension beam support, comprising:

[0009] Sand core components and gating systems, and extended beam castings formed by the combination of molten iron poured through a self-gating system and sand core components;

[0010] Two sand core components are symmetrically distributed on both sides of the casting system. The bosses in the middle of the two sand core components are thick-walled areas, and the same side of the two sand core components is a thin-walled area. The sand core component includes a chilled iron groove area and a support column cavity. The chilled iron groove area is located in the thick-walled area of ​​the boss in the middle of the sand core component, and the support column cavity vertically penetrates the thin-walled area.

[0011] As a further improvement to the above scheme, the groove depth of the chill groove area is 1.1-1.3 times the thickness of the chill, and the groove wall inclination angle is 5°-8°.

[0012] As a further improvement to the above scheme, the upper and lower ends of one side of the extended beam casting form an upper cantilever and a lower cantilever respectively under pouring conditions, with the upper and lower cantilever located in the thin-walled region.

[0013] As a further improvement to the above scheme, the support column is formed by pouring molten iron into the cavity of the support column. The upper and lower ends of the support column are connected to the upper cantilever and the lower cantilever respectively. The support column is made of the same material as the extension beam casting, and the upper and lower ends of the support column are provided with tapered interfaces with a taper of 1:10.

[0014] As a further improvement to the above scheme, the distance between the support column cavity and the upper and lower cantilever is >200mm, and the cavity cross-section is oval with a major axis of 40-50mm and a minor axis of 30-35mm.

[0015] As a further improvement to the above scheme, two risers and two thick bosses are symmetrically arranged in the front and rear sections of the gating system, respectively. The risers and gatings are ≤50mm away from the top of the thin-walled zone wall, and the cross-sectional area is 2-3 times the wall thickness at that location.

[0016] As a further improvement to the above scheme, a thick boss is set on top of the surrounding boss, containing a layer of thermal insulation cotton, and the riser volume is 1.8-2.2 times the volume of the shrinkage compensation zone.

[0017] As a further improvement to the above scheme, a chill block is installed in the chill groove area, and the chill block is made of low-grade gray cast iron with a 0.1mm alcohol-based aluminum oxide coating on its surface.

[0018] A casting process for an extension beam support, the process flow is as follows:

[0019] S1. The sand core component is optimized by CAE and pre-installed with chilled iron blocks. Based on the three-dimensional model of the extended beam, the filling solidification simulation is carried out to identify the shrinkage risk area and the deformation sensitive area.

[0020] S2. Gradient casting: stepped casting is used in thin-walled areas, and bottom casting with risers is used in thick-walled areas.

[0021] S3. Dynamic filling control: First, the thin-walled gate is activated, and the molten iron fills the thin-walled area within 8 seconds. After a delay of 3-5 seconds, the thick-walled gate is opened, and the molten iron is injected into the support rod cavity simultaneously.

[0022] S4. Coordinated solidification management: the cold iron block makes the cooling rate of the intermediate boss >10℃ / s, the riser feeding pressure ≥0.25MPa, and continues until the solidification degree of the thick-walled area reaches 90%.

[0023] S5. Support rod removal and regeneration: After the casting is cooled to room temperature and the product is cleaned, polished and inspected, it is machined into qualified finished parts. Then, the support column is cut along the tapered interface, and the support rod material is recycled and remelted.

[0024] As a further improvement to the above scheme, in step S1, the filling solidification simulation uses ProCAST software with a mesh size ≤2mm and a shrinkage cavity prediction accuracy >92%.

[0025] In step S2, the molten iron in the thin-walled gate contains 0.01-0.03% rare earth elements, and the molten iron in the thick-walled zone contains 0.5-1% nano-silicon zirconium inoculant.

[0026] In step S4, a 0.5T electromagnetic field is applied during riser feeding to promote the directional flow of molten iron.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. This invention, by setting up a sand core, a gating system, support rods, and chills, ensures that the product is free from casting defects such as shrinkage cavities and does not warp or deform, thereby producing a qualified product with stable quality that satisfies customers and has high market application value.

[0029] 2. This invention achieves high-speed filling of molten iron by opening a special gate in the thin-walled high-position area, reducing the cold shut defect rate from 12-18% in the traditional process to 0.8%. The cold iron is pre-placed in the sand core groove and combined with electromagnetic feeding to achieve sequential solidification, reducing the shrinkage rate of isolated thick-walled areas from 15% to 0%.

[0030] 3. This invention designs an oval cavity in the sand core and casts a support rod of the same material as the casting to connect the upper and lower cantilever arms. The deformation of the cantilever arms is reduced from 3.2-4.5mm in the traditional process to ≤0.8mm, which meets the requirements of high-precision assembly.

[0031] 4. This invention shortens the production cycle by using a zoned strategy of prioritizing thin-walled casting and delaying thick-walled casting, allowing 95% of the support rods to be remelted and reused, saving molten iron per ton of casting, and reducing costs. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of a casting process device for an extension beam support proposed in this invention.

[0033] Figure 2 For the present invention Figure 1 A schematic diagram of the three-dimensional structure from another perspective;

[0034] Figure 3 This is a schematic diagram of the structure of the sand core component of the present invention;

[0035] Figure 4 This is a schematic diagram of the connection structure between the extended beam casting and the gating system of the present invention;

[0036] Figure 5 This is a schematic diagram of the casting system of the present invention;

[0037] Figure 6 This is a schematic diagram of the connection structure of the extended beam casting, support column, and chilled iron block of the present invention.

[0038] Figure 7 For the present invention Figure 6 A schematic diagram of the three-dimensional structure;

[0039] Figure 8 This is a vertical guide flowchart of the casting process for the extension beam support of the present invention.

[0040] Explanation of key symbols:

[0041] 1. Extension beam casting; 11. Upper cantilever; 12. Lower cantilever; 2. Sand core component; 21. Chill groove area; 22. Support column cavity; 3. Gating system; 31. Riser and gating system; 32. Thick boss; 4. Support column component; 5. Chill block. Detailed Implementation

[0042] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0043] Example: Please refer to Figures 1-7 The present embodiment of an extension beam support casting process apparatus includes:

[0044] Sand core 2 and gating system 3, and the extended beam casting 1 formed by the molten iron poured through the self-gating system 3 in conjunction with the sand core 2;

[0045] Two sand core components 2 are symmetrically distributed on both sides of the casting system 3. The bosses between the two sand core components 2 are thick-walled areas, and the same side of the two sand core components 2 is a thin-walled area. The sand core component 2 includes:

[0046] The chill groove area 21 is located in the wall thickness area of ​​the middle boss of the sand core part 2. The groove depth is 1.1-1.3 times the thickness of the chill and the groove wall inclination angle is 5°-8°.

[0047] The support column cavity 22 extends through the upper and lower cantilever arms, and the spacing between the support column cavities 22 is greater than 200mm. The cavity cross-section is oval, with a major axis of 40-50mm and a minor axis of 30-35mm.

[0048] The gating system 3 has two risers and gating channels 31 and two thick bosses 32 symmetrically arranged at the front and rear sections respectively. The risers and gating channels 31 are ≤50mm away from the top of the thin high wall, and the cross-sectional area is 2-3 times the wall thickness at that point. The thick bosses 32 are located on the top of the peripheral bosses and include a thermal insulation layer with a density ≥150kg / m³. 3 The riser volume is 1.8-2.2 times the volume of the shrinkage zone.

[0049] The support column 4 is formed by pouring molten iron into the support column cavity 22. The upper and lower ends of the support column 4 are connected to the upper cantilever 11 and the lower cantilever 12, respectively. The support column 4 is made of the same material as the extension beam casting 1, and the upper and lower ends of the support column 4 are provided with tapered interfaces with a taper of 1:10.

[0050] Cold iron block 5 is placed in the cold iron groove area 21 and is made of low grade gray cast iron with a 0.1mm alcohol-based aluminum oxide coating on its surface.

[0051] Sand core: Due to the structural characteristics of extended beam products, some areas cannot be demolded. Therefore, a core-down method is used, with grooves designed in the corresponding positions of the sand core to hold chills. Before production, the chills are assembled into the sand core, and during molding, the sand core and chills are simultaneously lowered into the cavity. The shapes of the areas requiring support are also within the sand core, so support rod-shaped holes are made in the sand core. When molten iron is poured, these holes are filled with molten iron to form support rods, which are used to prevent product deformation.

[0052] Casting System 3: Due to the structural characteristics of the extension beam, the walls are relatively thin over a large area, and the walls are both thin and high in some areas, which easily leads to cold shut defects during production. The central boss has a local wall thickness and is isolated, while there are two large thick bosses around it. Shrinkage cavities are very likely to occur in the thick-walled areas during production. By opening a gate at the thin-walled and high position to introduce molten iron, it is ensured that the molten iron can quickly complete the filling within an effective time and prevent cold shut defects. Chips are placed on the thick-walled areas of the central boss to accelerate the cooling rate of the thick-walled areas and avoid shrinkage cavities. Risers are placed on the thick-walled areas around the perimeter for strong feeding to prevent shrinkage cavities.

[0053] Support column: The extension beam structure has two cantilever arms, upper and lower. Due to the thin walls and long distance between them, the cantilever arms are prone to warping and deformation during the casting process. To prevent this problem, a support rod is set to support the upper and lower cantilever arms. Since the sand core is placed at this position, the shape of the support rod is formed in the sand core (as mentioned earlier, the sand core cavity is the support column cavity 22). After all the product production processes are completed, the support rod is removed, and finally a qualified extension beam casting 1 is obtained.

[0054] Example 2: Combination Figures 1-8 The process method based on Example 1 includes the following steps:

[0055] S1, Sand core component 2 undergoes CAE optimization and pre-installation of chill block 5:

[0056] Based on the three-dimensional model of the extended beam, the filling and solidification simulation was carried out to identify the shrinkage risk area (middle boss, i.e., the chilled iron groove area 21) and the deformation sensitive area (cantilever, i.e. the forming area of ​​the upper cantilever 11 and the lower cantilever 12).

[0057] In the shrinkage risk area of ​​the sand core 2, the chill groove area 21 is machined (tolerance ±0.3mm), and the support rod cavity is formed in the deformation sensitive area;

[0058] Embed the chilled iron block 5 into the chilled iron groove area 21 and fix it with silica sol;

[0059] S2, Gradient casting design:

[0060] The thin-walled zone adopts a stepped casting method: the gate is divided into upper and lower layers, with the lower layer accounting for 70% of the cross-sectional area and the upper layer accounting for 30%, and the filling speed is 1.8-2.2 kg / s;

[0061] The thick-walled zone adopts bottom pouring + riser feeding: molten iron is introduced from the bottom through the straight pouring channel, and the riser channel 31 is inclined at 30° and cuts into the boss;

[0062] S3, Dynamic Filling Control:

[0063] First, start the thin-walled gate; the molten iron (1380-1420℃) fills the thin-walled area within 8 seconds.

[0064] After a 3-5 second delay, the thick-walled gating system is opened, simultaneously triggering the injection of molten iron into the support rod cavity.

[0065] S4, Collaborative Solidification Management:

[0066] The cold iron block 5 makes the cooling rate of the middle boss >10℃ / s (compared to ≤3℃ / s of the surrounding area);

[0067] The riser feeding pressure is ≥0.25MPa, and continues until the solidification degree of the thick-walled zone reaches 90%.

[0068] S5. Support rod removal and regeneration:

[0069] After the casting is cooled to room temperature and the product is cleaned, polished and inspected, it is machined into qualified finished parts. Then, the support column is cut along the tapered interface, and the support rod material is recycled and remelted, with a utilization rate of ≥95%.

[0070] in:

[0071] In step S1, the solidification simulation uses ProCAST software with a mesh size ≤ 2 mm and a shrinkage cavity prediction accuracy > 92%.

[0072] In step S2, the molten iron in the thin-walled gate contains 0.01-0.03% rare earth elements, and the molten iron in the thick-walled zone contains 0.5-1% nano-silicon zirconium inoculant.

[0073] In step S4, a 0.5T electromagnetic field is applied during riser feeding to promote the directional flow of molten iron.

[0074] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A casting process apparatus for an extension beam support, characterized in that, include: Sand core (2) and gating system (3), and extended beam casting (1) formed by the combination of molten iron poured by the self-gating system (3) and sand core (2); Among them, two sand core components (2) are symmetrically distributed on both sides of the casting system (3). The bosses in the middle of the two sand core components (2) are all thick-walled areas, and the two sand core components (2) are thin-walled areas on the same side. The sand core component (2) includes a chilled iron groove area (21) and a support column cavity (22). The chilled iron groove area (21) is located in the thick-walled area of ​​the boss in the middle of the sand core component (2), and the support column cavity (22) vertically penetrates the thin-walled area. The groove depth of the chill groove area (21) is 1.1-1.3 times the thickness of the chill, and the groove wall inclination angle is 5°-8°; The support column cavity (22) is filled with molten iron to form a support column (4). The upper and lower ends of the support column (4) are connected to the upper cantilever (11) and the lower cantilever (12) respectively. The support column (4) is made of the same material as the extension beam casting (1), and the upper and lower ends of the support column (4) are provided with tapered interfaces with a taper of 1:

10. The distance between the support column cavity (22) and the upper cantilever (11) and the lower cantilever (12) is >200mm, and the cavity cross section is oval, with a major axis of 40-50mm and a minor axis of 30-35mm. The gating system (3) is symmetrically provided with two risers (31) and two thick bosses (32) in the front and rear sections respectively. The risers (31) are ≤50mm away from the top of the thin-walled area and the cross-sectional area is 2-3 times the wall thickness at that point. A cold iron block (5) is installed in the cold iron groove area (21).

2. The casting process apparatus for an extension beam support as described in claim 1, characterized in that, The upper and lower ends of one side of the extended beam casting (1) form an upper cantilever (11) and a lower cantilever (12) respectively under pouring, and the upper cantilever (11) and the lower cantilever (12) are located in the thin-walled area.

3. The casting process apparatus for an extension beam support as described in claim 1, characterized in that, The thick boss (32) is located on the top of the peripheral boss, and contains a thermal insulation cotton layer. The riser volume is 1.8-2.2 times the volume of the shrinkage compensation zone.

4. The casting process apparatus for an extension beam support as described in claim 1, characterized in that, The chilled iron block (5) is a low-grade gray cast iron with a 0.1mm alcohol-based aluminum oxide coating on its surface.

5. A casting process for an extension beam support, characterized in that... Using the casting process apparatus for the extension beam support as described in any one of claims 1-4, the process flow is as follows: S1, the sand core component (2) is CAE optimized and the cold iron block (5) is pre-installed. Based on the three-dimensional model of the extension beam, the filling solidification simulation is carried out to identify the shrinkage risk area and the deformation sensitive area. S2. Gradient casting: stepped casting is used in thin-walled areas, and bottom casting with risers is used in thick-walled areas. S3. Dynamic filling control: First, the thin-walled gate is activated, and the molten iron fills the thin-walled area within 8 seconds. After a delay of 3-5 seconds, the thick-walled gate is opened, and the molten iron is injected into the support rod cavity simultaneously. S4. Coordinated solidification management, cold iron block (5) makes the cooling rate of the intermediate boss >10℃ / s, riser feeding pressure ≥0.25MPa, and continues until the solidification degree of the thick wall area reaches 90%; S5. Removal and regeneration of support column (4): After the casting is cooled to room temperature, the product is cleaned, polished and accepted, and then machined into qualified finished parts, the support column (4) is cut along the tapered interface and the material of the support column (4) is recycled and remelted.

6. The casting process for an extension beam support as described in claim 5, characterized in that: In step S1, the solidification simulation of the filling process was performed using ProCAST software, with a mesh size ≤2mm and a shrinkage cavity prediction accuracy >92%. In step S2, the molten iron in the thin-walled gate contains 0.01-0.03% rare earth elements, and the molten iron in the thick-walled zone contains 0.5-1% nano-silicon zirconium inoculant. In step S4, a 0.5T electromagnetic field is applied during riser feeding to promote the directional flow of molten iron.

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