Retractable composite core for metal casting

Abstract

The utility model discloses a contractible composite core for metal casting, which is characterized in that a plurality of movable core blocks form an annular core, end gaps and end gap liquid blocking devices are arranged among the movable cores, and casting liquid is prevented from flowing out of the end gaps. The bottom of each core block is a plane and is placed on the plane of the lower die or is respectively arranged on different rolling or static pressure guide rails, a gap between each core block and the bottom of the lower die is smaller than an overflow edge value or is filled with a refractory material, and each core block can freely move inwards along with the shrinkage of a casting in a solidification shrinkage stage after casting liquid is poured; and hot cracks caused by the obstruction of the mold core can be prevented.

Description

Technical Field

[0001] The utility model relates to a core, in particular to a shrinkable composite core for metal casting. Background Art

[0002] Hollow metal castings are common castings. In the prior art, a sand core can be placed in the hollow cavity position. Resin sand cores are used in the production process of large quantities of castings and are difficult to apply. Especially in the metal mold casting that needs to be applied in the production process of large quantities, it is even more impossible to be equipped with an environmentally friendly and low-cost metal core. Content of the Utility Model

[0003] In order to solve the above problems, the utility model provides a shrinkable composite core for metal casting, which can effectively solve the deficiencies in the prior art.

[0004] The utility model is realized by the following technical solutions: a shrinkable composite core for metal casting, the lower die is a structure with a middle plane plus a surrounding fence, a plurality of movable core blocks form a core ring, the bottom of each core block is a plane, there are gaps between the ends of each core block, and there is a liquid blocking device at each end gap to prevent the casting liquid from flowing out. The movable core blocks can move relative to the lower die plane and can be supported by sliding or rolling or hydrostatic pressure when moving.

[0005] As a preferred technical solution, there is compressible fireproof material between the end gaps.

[0006] As a preferred technical solution, the filling material can be aluminosilicate cotton or porous vacuum silicon heat insulation cotton.

[0007] As a preferred technical solution, there is a liquid blocking sheet outside the end gaps. The liquid blocking sheet, the pull rod and the pull rod seat form an I-shaped structure and are clamped between two adjacent movable core blocks.

[0008] As a preferred technical solution, an inner liquid blocking sheet is fixed inside one of the two adjacent movable core blocks to seal the gap.

[0009] As a preferred technical solution, each movable core block is placed on the lower die plane.

[0010] As a preferred technical solution, there is a concave plane in the movable core parallel to the lower die plane. There are spherical balls or cylindrical rollers between the two planes. The gap between the lower plane of the movable core and the lower die plane can be smaller than the overflow value of the casting liquid, or filled with aluminosilicate or porous vacuum silicon.

[0011] As a preferred technical solution, there are several groups of cross-rolling guide rails. Each movable core block is installed on the moving guide rail of an independent rolling 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 die plane can be less than the overflow value of the casting liquid, or it can be filled with aluminum silicate or porous vacuum silicon.

[0012] As a preferred technical solution, there are several groups 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 die plane can be less than the overflow value of the casting liquid, or it can be filled with aluminum silicate or porous vacuum silicon.

[0013] The beneficial effects of the present utility model are as follows: An annular core is composed of several movable core blocks. There are end gaps and end-gap liquid-blocking devices between the movable cores to prevent the casting liquid from flowing out through the end gaps. The bottom of each core block is a plane and is placed on the lower die plane or is respectively installed on the moving guide rails of different rolling or hydrostatic guide rails. The gap between each core block and the bottom of the lower die is less than the overflow value or is filled with refractory materials. During the solidification and shrinkage stage after the casting liquid is poured in, each core block can freely move inward with the shrinkage of the casting, and thermal cracks caused by the obstruction of the core can be prevented. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0015] Figure 1 It is the top view and cross-sectional view of the casting with round holes of the present utility model;

[0016] Figure 2 It is the top view and cross-sectional view of the casting with rectangular holes of the present utility model;

[0017] Figure 3 It is the top view (one) of the casting core and the casting mold of the casting with round holes of the present utility model;

[0018] Figure 4 It is the top view (two) of the casting core and the casting mold of the casting with round holes of the present utility model;

[0019] Figure 5 It is the cross-sectional view of the casting core and the casting mold of the casting with round holes of the present utility model;

[0020] Figure 6 It is the top view (one) of the casting core and the casting mold of the casting with rectangular holes of the present utility model;

[0021] Figure 7 Top view (2) of the casting core with rectangular holes and the casting mold of the present utility model;

[0022] Figure 8 Cross-sectional view of the casting core with rectangular holes and the casting mold of the present utility model;

[0023] Figure 9 Structural and installation schematic diagram of the outer sealing wall panel of the present utility model;

[0024] Figure 10 Schematic diagram of the arrangement of the core blocks without angle gauges of the present utility model;

[0025] Figure 11 Schematic diagram of the one-dimensional rolling guide of the present utility model;

[0026] Figure 12 Top view of the two-dimensional rolling guide of the present utility model

[0027] Figure 13 Side view of the two-dimensional rolling guide of the present utility model;

[0028] Figure 14 Combined schematic diagram of the two-dimensional rolling guide and the core block of the present utility model;

[0029] Figure 15 Top view of the combination of four groups of two-dimensional rolling guides of the present utility model;

[0030] Figure 16 Top view of the combination of four groups of two-dimensional rolling guides plus core blocks of the present utility model;

[0031] Figure 17 Cross-sectional view of the combination of the two-dimensional rolling guide plus core block and the casting mold of the present utility model;

[0032] Figure 18 Schematic diagram of the gap between the rolling support core block and the bottom plane of the casting mold of the present utility model;

[0033] Figure 19 Schematic diagram of the rolling support core block, the bottom plane of the casting mold plus the anti-leakage strip of the present utility model;

[0034] Figure 20 Schematic diagram of the positioning relationship of the initial positioning bracket of the rolling support core block of the present utility model;

[0035] Figure 21 Schematic diagram of the relationship between the direct roller support core block and the casting mold of the present utility model;

[0036] Figure 22 Schematic diagram of the positional relationship between the direct roller support core block and the casting mold plus the initial positioning bracket of the present disclosure;

[0037] Figure 23 Schematic installation diagram of the inner sealing plate structure of the present utility model;

[0038] Figure 24 Schematic installation diagram of the inner corner sealing plate structure of the present utility model;

[0039] Explanation of reference numerals in the drawings:

[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. Movable core block with rollers at the bottom; 4041. Rolling support plane; 5. Sealing device; 501. Refractory 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 with core block with rolling guide; 7. Rolling guide seat; 8. Moving guide of rolling guide; 9. Moving guide of two-layer rolling guide; 10. Mold base; 11. Leakage prevention strip; 12. Rolling element; 13. Initial positioning plate of rolling support core block; 14. Positioning hook of initial positioning plate. Detailed implementation manners

[0041] All features disclosed in this specification, or all steps in the disclosed methods or processes, except for mutually exclusive features and / or steps, can be combined in any manner.

[0042] Any feature disclosed in this specification (including any additional claims, abstract, and drawings), unless specifically stated, can be replaced by other equivalent or similar-purpose alternative features. That is, unless specifically stated, each feature is only an example in a series of equivalent or similar features.

[0043] Embodiment 1

[0044] As Figure 1 and Figure 2 shown, the castings with circular hole casting 1 and rectangular hole casting 2 are common castings. During casting, a core can be placed at the position of the circular hole or rectangular hole to cast a circular or rectangular hole. However, when the size of the circular hole 101 or rectangular hole 201 is large, due to the solidification shrinkage of the casting liquid, casting Figure 1 Circular hole casting 1, the mold is as Figure 3 shown, and the cross-sectional view is as Figure 5As shown, there are four circular-hole movable core blocks 401 placed on the bottom plane of the circular mold 3. There are gaps at the ends between the circular-hole movable core blocks 401, and a refractory elastic sealing plate 501 is placed in the gaps. The casting liquid is poured into the position formed between the circular mold 3 and each circular-hole movable core block 401 (such as Figure 5 in 1). When the casting liquid solidifies and shrinks, the refractory elastic sealing plate 501 can be squeezed so that the core combination formed by the four circular-hole movable core blocks 401 and the refractory elastic sealing plate 501 can shrink inward, and cracks caused by the core hindering shrinkage can be avoided. The gap sealing device between each circular-hole movable core block 401 can be replaced by Figure 4 the outer sealing plate 502 in Figure 3 The combination of the refractory elastic sealing plate 501, the outer sealing plate 502, the outer sealing plate pull rod 503, and the outer sealing plate pull rod seat 504 in Figure 9 is shown as follows. The outer sealing plate pull rod 503 and the outer sealing plate pull rod seat 504 are respectively stuck on the inner and outer sides of two movable core blocks 4.

[0045] Embodiment 2

[0046] The rectangular-hole casting 2 is implemented as shown in Figures 6 - 9 Combined with Figure 6 and Figure 8 , there are several L-shaped movable core blocks 402 and straight-bar movable core blocks 403 placed on the bottom plane of the rectangular mold 6. There are gaps between each L-shaped movable core block 402 and straight-bar movable core block 403, and a refractory elastic sealing plate 501 is placed in each gap. The refractory elastic sealing plates 501 between each L-shaped movable core block 402 and straight-bar movable core block 403 together form a core. When the casting liquid is poured into Figure 8 in 2) and starts to solidify and shrink, since the refractory elastic sealing plate 501 can be compressed, each straight-bar movable core block 403 and straight-bar movable core block 403 can shrink inward, and thermal cracks caused by the core hindrance can be avoided.

[0047] Embodiment 3

[0048] As shown in Figure 23 , the gap liquid-blocking device between two movable core blocks is the inner sealing plate 505 and the inner sealing plate fixing screw 506. The inner sealing plate 505 is fixed on one of the movable core blocks with the inner sealing plate fixing screw 506. The corner gap is as shown in Figure 24As shown, the inner corner plugging plate 507 and the inner plugging plate fixing screw 506 are used. The inner corner plugging plate 507 is fixed to one of the movable core blocks with the inner plugging plate fixing screw 506. Since the liquid-blocking device of this solution is installed inside the core combination, molten metal enters the end gap, which needs to be cut off after casting. At the same time, due to the molten metal entering the end gap, its shrinkage performance decreases. For each gap of about 200 - 300 mm, an end gap needs to be set, and the value of the end gap needs to be about 5 - 10 mm. The advantage of this solution is that there is no need to fill compressible refractory materials before casting. Compared with Embodiment 2, neither the inner plugging plate 505 nor the inner corner plugging plate 507 is disposable and does not need to be replaced.

[0049] Embodiment 4

[0050] As Figures 11 - 16 shown, Figure 11 Inside are the rolling guide rail base 7 and the rolling guide rail moving guide 8, with rollers (not shown in the figure) in between. The rolling guide rail moving guide 8 can move along the arrow direction. Figure 12 It is on the Figure 11 basis with several second-layer rolling guide rail moving guides 9 added. The second-layer rolling guide rail moving guides 9 can move in the Figure 12 direction shown by the arrow. Figure 13 It is Figure 12 the side view of. Figure 14 It is Figure 13 a schematic diagram of installing the straight bar movable core block 403 on each of the second-layer rolling guide rail moving guides 9 on the basis of the two-dimensional rolling guide rail. The straight bar movable core block 403 can move in two directions relative to the rolling guide rail base 7, and the moving directions Figure 14 are marked. Figure 15 It is the top view of the combined layout of four groups of two-dimensional movable guide rails. Figure 16 It is Figure 15 the top view after adding several straight bar movable core blocks 403 on the basis of.

[0051] Figure 17 For Figure 16 the combined cross-sectional view of the rolling guide rail and the straight bar movable core block 403 combination shown in, the rectangular hole mold with rolling guide rail core block 601 and the combination of the rolling guide rail and the straight bar movable core block 403 in the figure are both installed on the mold base 10.

[0052] Figure 18 It is a schematic diagram of the gap between the rolling support core block and the bottom plane of the mold. There is a gap δ between the bottom plane of the straight bar movable core block 403 combination and the rectangular hole mold with rolling guide rail core block 601. δ is less than the molten metal overflow value, and the molten metal will not flow out from the gap δ. It is also possible to increase the value of δ as shown in Figure 19 and add a leak-proof strip 11 to prevent the molten metal from flowing out.Figure 20 Before the casting liquid is poured, there is a rolling support core block initial positioning plate 13 positioned between the straight movable core blocks 403. At this time, the straight movable core blocks 403 are abutted against the periphery of the rolling support core block initial positioning plate 13. The rolling support core block initial positioning plate 13 is installed on the initial positioning plate positioning hook 4, and the initial positioning plate positioning hook 4 is placed on the upper part of the rectangular hole mold 601 of the core block with a rolling guide rail. There is a positioning hook at the end, which hooks one side of the rectangular hole mold 601 of the core block with a rolling guide rail, so that the straight movable core blocks 403 and the mold are relatively positioned. After the casting liquid is poured, the initial positioning plate positioning hook 14 and the rolling support core block initial positioning plate 13 are removed. At this time, the straight movable core blocks 403 can move inwards.

[0053] Example 5

[0054] The difference from Example 1 and Example 2 is that as Figure 20 shown, there is a movable core block 404 with rollers at the bottom, and there is a concave plane rolling support plane 4041 in the middle. The rolling support plane 4041 is parallel to the bottom plane of the rectangular mold 6. There are rolling elements 12 supporting between the two planes. When the casting liquid solidifies and shrinks, it pushes the movable core block 404 with rollers at the bottom to move inwards. Due to the action of the rolling elements 12, the friction coefficient is very small, which can avoid the unsmooth movement of the movable core block caused by excessive friction between the movable core block and the bottom plane of the mold, and thus prevent the thermal cracking of the casting. Figure 20 Before the casting liquid is poured, there is a rolling support core block initial positioning plate 13 positioned between the straight movable core blocks 403. At this time, the straight movable core blocks 403 are abutted against the periphery of the rolling support core block initial positioning plate 13. The rolling support core block initial positioning plate 13 is installed on the initial positioning plate positioning hook 4, and the initial positioning plate positioning hook 4 is placed on the upper part of the rectangular hole mold 601 of the core block with a rolling guide rail. There is a positioning hook at the end, which hooks one side of the rectangular hole mold 601 of the core block with a rolling guide rail, so that the straight movable core blocks 403 and the mold are relatively positioned. After the casting liquid is poured, the initial positioning plate positioning hook 14 and the rolling support core block initial positioning plate 13 are removed. At this time, the straight movable core blocks 403 can move inwards. Figure 20 The end positioning of the initial positioning plate positioning hook and the rectangular hole mold 601 of the core block with a rolling guide rail in is bidirectional, and the other direction is not drawn. There are several teeth on the rolling support core block initial positioning plate 13 that catch the gaps between the movable core blocks 404 with rollers at the bottom.

[0055] Example 6

[0056] The difference from the above examples is that a hydrostatic guide rail is used instead of a rolling guide rail, which can make the moving resistance of the movable core block smaller.

[0057] The beneficial effects of the utility model are as follows: a plurality of movable core blocks are used to form an annular core, end gaps and end gap liquid blocking devices are provided between the movable cores to prevent the casting liquid from flowing out of the end gaps, the bottom of each core block is a plane placed on the plane of the lower mold or respectively 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, and in the solidification shrinkage stage after the casting liquid is poured in, each core block can move freely inward with the shrinkage of the casting, thereby preventing thermal cracks caused by the obstruction of the core.

[0058] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that are not conceived through creative work should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope defined in the claims.

Claims

1. A shrinkable composite core for metal casting, composed of a lower mold and a composite core, characterized in that: The lower mold has a structure of a middle plane plus a surrounding fence. A core ring is composed of several movable core blocks. The bottom of each core block is a plane, and there are gaps between the ends of each core block. There is a liquid-blocking device at each end gap to prevent the casting liquid from flowing out. The movable core blocks can move relative to the lower mold plane and can be supported by sliding, rolling or hydrostatic pressure when moving.

2. The shrinkable composite core for metal casting according to Claim 1, wherein: There is compressible fireproof material between the end gaps.

3. The shrinkable composite core for metal casting according to claim 2, wherein: The filling material can be aluminum silicate wool or porous vacuum silicon heat insulation wool.

4. The shrinkable composite core for metal casting according to claim 1, characterized in that: There is a liquid-blocking sheet outside the end gaps. The liquid-blocking sheet, the pull rod and the pull rod seat form an I-shaped structure and are clamped between two adjacent movable core blocks.

5. The shrinkable composite core for metal casting according to claim 1, characterized in that: One of the two adjacent movable core blocks has an inner liquid-blocking sheet fixed inside to seal the gap.

6. The shrinkable composite core for metal casting according to claim 1, wherein: Each movable core block is placed on the lower mold plane.

7. The shrinkable composite core for metal casting according to claim 1, wherein: There is a concave plane parallel to the lower mold plane inside the movable core. There are spherical balls 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 edge value of the casting liquid, or filled with aluminum silicate or porous vacuum silicon.

8. The shrinkable composite core for metal casting according to claim 1, characterized in that: There are several groups of cross-rolling guide rails. Each movable core block is installed on the moving guide rail of an independent rolling guide rail. The moving guide rail and the movable core block are combined and 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 smaller than the overflow edge value of the casting liquid, or filled with aluminum silicate or porous vacuum silicon.

9. The shrinkable composite core for metal casting according to claim 1, wherein: There are several groups of cross-hydrostatic guide rails. Each movable core block is installed on the moving guide rail of an independent hydrostatic guide rail. The moving guide rail and the movable core block are combined and 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 smaller than the overflow edge value of the casting liquid, or filled with aluminum silicate or porous vacuum silicon.

Images