Retractable composite core for metal casting
By setting movable core blocks and liquid-blocking devices between the core blocks, and using materials such as aluminum silicate cotton or porous vacuum silicon to fill the gaps, the problem of hot cracking in the mass production of hollow metal castings is solved, achieving environmentally friendly and low-cost casting results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2026-03-31
AI Technical Summary
In the current technology, it is difficult to use environmentally friendly and low-cost metal cores when mass-producing hollow metal castings, especially since hot cracking is prone to occur during the casting process.
A shrinkable composite core structure is adopted. By setting movable core blocks and liquid blocking devices between the core blocks, the movable core blocks move inward during the solidification and shrinkage stage of the casting liquid, avoiding hot cracks caused by core obstruction. Materials such as aluminum silicate cotton or porous vacuum silicon are used to fill the gaps, and rolling or hydrostatic guide rails are used to support the movement of the core blocks.
It effectively prevents hot cracking caused by core obstruction, and realizes environmentally friendly and low-cost casting for mass production of hollow metal castings.
Smart Images
Figure CN121755652A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a core, specifically a shrinkable composite core for metal casting. Background Technology
[0002] Hollow metal castings are common castings. With current technology, sand cores can be placed in the hollow cavity. However, resin sand cores are used in mass production processes, which are difficult to apply, especially for metal mold casting that requires mass production. It is even more difficult to match them with environmentally friendly and low-cost metal cores. Summary of the Invention
[0003] To address the aforementioned problems, this invention provides a shrinkable composite core for metal casting, which effectively overcomes the shortcomings of existing technologies.
[0004] The present invention is achieved through the following technical solution: a shrinkable composite core for metal casting, wherein the lower mold is a structure with a central plane and a surrounding fence, and a core ring is composed of several movable core blocks. The bottom of each core block is a plane, and there is a gap between the ends of each core block. Each end gap has a liquid-blocking device to prevent the casting liquid from flowing out. The movable core blocks can move relative to the plane of the lower mold and can be supported by sliding, rolling or static pressure when moving.
[0005] As a preferred technical solution, the end gap contains compressible fireproof material.
[0006] As a preferred technical solution, the filling material can be aluminum silicate cotton or porous vacuum silicone insulation cotton.
[0007] As a preferred technical solution, there is a liquid blocking sheet on the outside of the end gap. The liquid blocking sheet, the pull rod, and the pull rod seat form an I-shape and are locked between two adjacent movable core blocks.
[0008] As a preferred technical solution, one of the two adjacent movable core blocks has an inner liquid-blocking sheet fixed inside to seal the gap.
[0009] As a preferred technical solution, each movable core block is placed on the lower mold plane.
[0010] As a preferred technical solution, the movable core has a concave plane parallel to the lower mold plane, and the two planes have spherical or cylindrical rollers. The gap between the lower plane of the movable core and the lower mold plane can be less than the overflow value of the casting liquid, or it can be filled with aluminum silicate or porous vacuum silicate.
[0011] As a preferred technical solution, there are several sets of cross-shaped rolling guides. Each movable core block is installed on the moving guide of an independent rolling guide. The combination of the moving guide and the movable core block can move freely in the shrinkage direction. The gap between the bottom plane of the movable core block and the lower mold plane can be less than the overflow value of the casting liquid, or it can be filled with aluminum silicate or porous vacuum silicate.
[0012] As a preferred technical solution, there are several sets of cross hydrostatic guide rails. Each movable core block is installed on the moving guide rail of an independent hydrostatic guide rail. The combination of the moving guide rail and the movable core block can move freely in the shrinkage direction. The gap between the bottom plane of the movable core block and the lower mold plane can be less than the overflow value of the casting liquid, or it can be filled with aluminum silicate or porous vacuum silicate.
[0013] The beneficial effects of this invention are as follows: a ring-shaped core is composed of several movable core blocks, and there are end gaps and end gap liquid blocking devices between each movable core to prevent the molten casting from flowing out of the end gaps. The bottom of each core block is a flat surface and is placed on the lower mold plane or mounted on different rolling or hydrostatic guide rails. The gap between each core block and the bottom of the lower mold is less than the overflow value or is filled with refractory material. During the solidification and shrinkage stage after the molten casting is poured in, each core block can move freely inward with the shrinkage of the casting, which can prevent hot cracks caused by the obstruction of the core. Attached Figure Description
[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0015] Figure 1 These are a top view and a sectional view of the casting with a circular hole according to the present invention;
[0016] Figure 2 These are the top view and sectional view of the casting with rectangular holes according to the present invention;
[0017] Figure 3 A top view (a) of the casting core and mold with a round hole of the present invention;
[0018] Figure 4 This is a top view (II) of the casting core and mold for the casting with a round hole according to the present invention;
[0019] Figure 5 This is a cross-sectional view of the casting core and mold for the casting with a round hole according to the present invention;
[0020] Figure 6 A top view (a) of the casting core and mold with rectangular hole of the present invention;
[0021] Figure 7 This is a top view (II) of the casting core and mold for the casting with rectangular holes according to the present invention;
[0022] Figure 8 This is a sectional view of the casting core and mold with rectangular holes of the present invention;
[0023] Figure 9 This is a schematic diagram of the outer sealing wall panel structure and installation of the present invention;
[0024] Figure 10 This is a schematic diagram of the arrangement of the core block without the angle ruler of the present invention;
[0025] Figure 11 This is a schematic diagram of a one-dimensional rolling guide rail according to the present invention;
[0026] Figure 12 This is a top view of the two-dimensional rolling guide rail of the present invention.
[0027] Figure 13 This is a side view of the two-dimensional rolling guide rail of the present invention;
[0028] Figure 14 This is a schematic diagram of the combination of the two-dimensional rolling guide rail and the core block of the present invention;
[0029] Figure 15 This is a top view of the four sets of two-dimensional rolling guide rails of the present invention;
[0030] Figure 16 This is a top view of the four sets of two-dimensional rolling guides plus the core block combination of the present invention;
[0031] Figure 17 A cross-sectional view of the two-dimensional rolling guide rail of the present invention, including the core block assembly and the mold assembly;
[0032] Figure 18 This is a schematic diagram showing the gap between the rolling support core block and the bottom plane of the mold according to the present invention;
[0033] Figure 19 A schematic diagram showing the addition of a leak-proof strip to the rolling support core block and the bottom plane of the mold according to the present invention;
[0034] Figure 20 A schematic diagram of the initial positioning relationship of the rolling support type core block of the present invention;
[0035] Figure 21 A schematic diagram showing the relationship between the direct roller-supported core block and the mold according to the present invention;
[0036] Figure 22 This is a schematic diagram showing the positional relationship between the direct roller-supported mandrel and the mold plus the initial positioning bracket in this invention;
[0037] Figure 23 This is a schematic diagram of the installation of the inner sealing plate structure of the present invention;
[0038] Figure 24 This is a schematic diagram of the installation of the inner corner sealing plate structure of the present invention;
[0039] Explanation of reference numerals in the attached figures:
[0040] 1. Circular hole casting; 101. Circular hole; 2. Rectangular hole casting; 201. Rectangular hole; 3. Circular mold; 4. Movable core block; 401. Circular hole movable core block; 402. Angle-shaped movable core block; 403. Straight bar movable core block; 404. Bottom roller movable core block; 4041. Rolling support plane; 5. Sealing device; 501. Fire-resistant elastic sealing plate; 502. Outer sealing plate; 503. Outer sealing plate tie rod; 504. Outer sealing plate tie rod seat; 505. Inner sealing plate; 506. Inner sealing plate fixing screw; 507. Inner corner sealing plate; 6. Rectangular mold; 601. Rectangular hole mold of core block with rolling guide rail; 7. Rolling guide rail seat; 8. Rolling guide rail moving guide rail; 9. Two-layer rolling guide rail moving guide rail; 10. Mold seat; 11. Leak-proof strip; 12. Rolling element; 13. Rolling support core block initial positioning plate; 14. Initial positioning plate positioning hook. Detailed Implementation
[0041] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.
[0042] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.
[0043] Example 1
[0044] like Figure 1 and Figure 2 The castings shown, 1 with a round hole and 2 with a rectangular hole, are common castings. During casting, a core is placed at the location of the round or rectangular hole to produce the desired hole. However, when the size of the round hole 101 or the rectangular hole 201 is large, the solidification shrinkage of the molten casting can cause casting defects. Figure 1 Casting 1 with round hole, mold as follows Figure 3 As shown, the sectional view is as follows Figure 5 As shown, four movable core blocks 401 with circular holes are placed on the bottom plane of the circular mold 3. There are gaps at the ends between the movable core blocks 401 with circular holes, and refractory elastic sealing plates 501 are placed in the gaps. The molten casting is poured into the circular mold 3 and the positions formed between each movable core block 401 with circular holes (e.g., Figure 5 1) During the solidification of the molten casting, shrinkage occurs. The refractory elastic sealing plate 501 can be compressed, allowing the core assembly formed by the four circular movable core blocks 401 and the refractory elastic sealing plate 501 to shrink inward. This prevents cracks caused by the core hindering shrinkage. The gap sealing device between the circular movable core blocks 401 can be used... Figure 4 The outer sealing plate 502 is replaced in the middle. Figure 3 The fire-resistant elastic sealing plate 501, the outer sealing plate 502, the outer sealing plate tie rod 503, and the outer sealing plate tie rod seat 504 are combined as follows: Figure 9 As shown, the outer sealing plate tie rod 503 and the outer sealing plate tie rod seat 504 are respectively locked on the inner and outer sides of the two movable core blocks 4.
[0045] Example 2
[0046] Rectangular hole casting 2 implementation as follows Figures 6-9 As shown, combined with Figure 6 and Figure 8 Several rectangular movable core blocks 402 and straight movable core blocks 403 are placed on the bottom plane of a rectangular mold 6. There are gaps between the rectangular movable core blocks 402 and the straight movable core blocks 403, and refractory elastic sealing plates 501 are placed between each gap. The refractory elastic sealing plates 501 between the rectangular movable core blocks 402 and the straight movable core blocks 403 together form the core. When the molten casting is poured in… Figure 8 2) When solidification and shrinkage begin, the refractory elastic sealing plate 501 can be compressed, and each straight movable core block 403 can shrink inward, which can avoid thermal cracks caused by the obstruction of the core.
[0047] Example 3
[0048] like Figure 23 As shown, the gap-blocking device between the two movable core blocks consists of an inner sealing plate 505 and an inner sealing plate fixing screw 506. The inner sealing plate 505 is fixed to one of the movable core blocks by the inner sealing plate fixing screw 506. The corner gap is as follows: Figure 24 As shown, the inner corner sealing plate 507 and the inner corner sealing plate fixing screw 506 are used. The inner corner sealing plate 507 is fixed to one of the movable core blocks by the inner corner sealing plate fixing screw 506. Because the liquid blocking device of this solution is installed on the inner side of the core assembly, molten casting enters in the end gap and needs to be removed after casting. At the same time, since the shrinkage performance of the molten casting enters the end gap, the gap is about 200-300mm, so an end gap needs to be set. The end gap value needs to be about 5-10mm. The advantage of this solution is that it does not require filling compressible refractory material before casting. Compared with Example 2, the inner corner sealing plate 505 and the inner corner sealing plate 507 are not disposable and do not need to be replaced.
[0049] Example 4
[0050] like Figure 11-16 As shown, Figure 11The middle section consists of a rolling guide rail seat 7 and a rolling guide rail moving guide rail 8, with rollers (not shown in the figure) in between. The rolling guide rail moving guide rail 8 can move in the direction of the arrow. Figure 12 Is Figure 11 Based on the existing structure, several double-layer rolling guides and moving guides 9 are added. The double-layer rolling guides and moving guides 9 can... Figure 12 Move in the direction indicated by the arrow. Figure 13 yes Figure 12 Side view, Figure 14 yes Figure 13 A schematic diagram showing a straight movable core block 403 mounted on each of the two layers of rolling guide rails 9, based on a two-dimensional rolling guide rail. The straight movable core block 403 can move in two directions relative to the rolling guide rail seat 7. Figure 14 There are signs in it. Figure 15 It is a top view showing the arrangement of four sets of two-dimensional movable guide rails. Figure 16 yes Figure 15 A top view after adding several straight movable core blocks 403 to the base.
[0051] Figure 17 for Figure 16 The figure shows a cross-sectional view of the combination of the rolling guide rail and the straight movable core block 403 with the rectangular hole mold 601 of the core block with the rolling guide rail. Both the rectangular hole mold 601 of the core block with the rolling guide rail and the combination of the rolling guide rail and the straight movable core block 403 are mounted on the mold base 10.
[0052] Figure 18 This is a schematic diagram showing the gap between the rolling support core block and the bottom plane of the mold. There is a gap δ between the straight movable core block 403 assembly and the bottom plane of the rectangular hole mold 601 with the rolling guide core block. δ is less than the overflow value of the molten casting, so the molten casting will not flow out from the gap δ. Alternatively, it can be like... Figure 19 The δ value is increased as shown, and a leak-proof strip 11 is added to prevent the casting liquid from flowing out. Figure 20 To position the movable core blocks 403 with a rolling support type initial positioning plate 13 before the molten casting is poured in, each movable core block 403 is placed against the rolling support type initial positioning plate 13. The rolling support type initial positioning plate 13 is mounted on the initial positioning plate positioning hook 4. The initial positioning plate positioning hook 4 is placed on the upper part of the mold 601 with the rectangular hole of the core block with the rolling guide rail. The end of the hook has a positioning hook that hooks onto one side of the mold 601 with the rectangular hole of the core block with the rolling guide rail, so that each movable core block 403 and the mold are positioned relative to each other. After the molten casting is poured in, the initial positioning plate positioning hook 14 and the rolling support type initial positioning plate 13 are removed, and each movable core block 403 can move inward.
[0053] Example 5
[0054] The difference between Example 1 and Example 2 is as follows: Figure 20As shown, there is a movable core block 404 with rollers at the bottom and a concave rolling support plane 4041 in the middle. The rolling support plane 4041 is parallel to the bottom plane of the rectangular mold 6, and there is a rolling element 12 supporting the two planes. When the molten casting solidifies and shrinks, it pushes the movable core block 404 with rollers at the bottom to move inward. Due to the action of the rolling element 12, the coefficient of friction is very small, which can avoid the hot cracking of the casting caused by the movable core block not moving smoothly due to excessive friction between the movable core block and the bottom plane of the mold. Figure 20 To position the movable core blocks 403 before the molten casting is poured in, a rolling support core block initial positioning plate 13 is used. At this time, each movable core block 403 is positioned against the rolling support core block initial positioning plate 13. The rolling support core block initial positioning plate 13 is mounted on the initial positioning plate positioning hook 4, which is placed on the upper part of the rectangular hole mold 601 with rolling guide core blocks. The initial positioning hook 4 has a positioning hook at its end that hooks onto one side of the rectangular hole mold 601 with rolling guide core blocks, thus positioning each movable core block 403 relative to the mold. After the molten casting is poured in, the initial positioning plate positioning hook 14 and the rolling support core block initial positioning plate 13 are removed, allowing each movable core block 403 to move inward. Figure 20 The initial positioning plate positioning hook and the end positioning of the rectangular hole mold 601 with rolling guide rail are bidirectional, the other direction is not shown. The initial positioning plate 13 of the rolling support core block has several locking teeth to lock the gap between each bottom roller movable core block 404.
[0055] Example 6
[0056] The difference from the above embodiments is that a hydrostatic guide rail is used instead of a rolling guide rail, which can reduce the moving resistance of the movable core block.
[0057] The beneficial effects of this invention are as follows: a ring-shaped core is composed of several movable core blocks, and there are end gaps and end gap liquid blocking devices between each movable core to prevent the molten casting from flowing out of the end gaps. The bottom of each core block is a flat surface and is placed on the lower mold plane or mounted on different rolling or hydrostatic guide rails. The gap between each core block and the bottom of the lower mold is less than the overflow value or is filled with refractory material. During the solidification and shrinkage stage after the molten casting is poured in, each core block can move freely inward with the shrinkage of the casting, which can prevent hot cracks caused by the obstruction of the core.
[0058] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions conceived without inventive effort should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.
Claims
1. A collapsible composite core for metal casting, consisting of a lower mold and a composite core, characterized in that: The lower mold is a middle plane plus a surrounding fence structure, a number of movable core blocks form a core ring, the bottom of each core block is a plane, there is a gap between the end of each core block, there is a liquid blocking device between the end gap to prevent the flow of liquid, the movable core block can move relative to the lower mold plane, and can be supported by sliding, rolling or static pressure when moving.
2. The collapsible composite core for metal casting according to claim 1, characterized in that: There is a compressible fireproof material between the end gaps.
3. The collapsible composite core for metal casting according to claim 2, characterized in that: The filling material can be aluminum silicate cotton or porous vacuum silicon thermal insulation cotton.
4. The collapsible composite core for metal casting according to claim 1, characterized in that: There is a liquid blocking sheet outside the end gap, the liquid blocking sheet, the pull rod and the pull rod seat form a I-shaped structure, and are clamped between the two adjacent movable core blocks.
5. The collapsible composite core for metal casting of claim 1, wherein: One of the two adjacent movable core blocks has an inside liquid blocking sheet fixed inside to seal the gap.
6. The collapsible composite core for metal casting of claim 1, wherein: Each movable core block is placed on the lower mold plane.
7. The collapsible composite core for metal casting according to claim 1, characterized in that: There is a concave plane inside the movable core which is parallel to the lower mold plane, and there are spherical or cylindrical rollers between the two planes, the gap between the lower plane of the movable core and the lower mold plane can be smaller than the overflow value of the liquid, or it can be filled with aluminum silicate or porous vacuum silicon.
8. The collapsible composite core for metal casting of claim 1, wherein: There are several groups of cross-shaped rolling guide rails, each movable core block is installed on the moving guide rail of the independent rolling guide rail, the moving guide rail and the movable core block are combined, and can freely move in the shrinkage direction, the gap between the bottom plane of the movable core block and the lower mold plane can be smaller than the overflow value of the liquid, or it can be filled with aluminum silicate or porous vacuum silicon.
9. The collapsible composite core for metal casting of claim 1, wherein: There are several groups of cross-shaped static pressure guide rails, each movable core block is installed on the moving guide rail of the independent static pressure guide rail, the moving guide rail and the movable core block are combined, and can freely move in the shrinkage direction, the gap between the bottom plane of the movable core block and the lower mold plane can be smaller than the overflow value of the liquid, or it can be filled with aluminum silicate or porous vacuum silicon.