A thin-wall spiral case casting mold

Abstract

The utility model discloses a kind of thin-wall spiral case casting mould, belong to spiral case casting equipment technical field, thin-wall spiral case is composed of spiral case upper half and spiral case lower half, including upper combined sand box and lower combined sand box: upper combined sand box includes first upper sand box, first lower sand box and first core pin, first upper sand box and first core pin between there is first compacting surface and form first cavity of pattern;The first parting surface between first upper sand box and first lower sand box is lower than first compacting surface;First upper sand box and first core pin also form several first locating plate cavities, and first locating plate cavity is communicated with first cavity of pattern;The structure of lower combined sand box is same with upper combined sand box;Thin-wall spiral case of the utility model is two half structures, and each half structure is separately casted by upper and lower combined sand box, and core pin in combined sand box no longer has cantilever core structure, and it will not float or displace in pouring process, solve the problem of wall thickness control difficulty and the problem of casting internal cavity flaw detection and defect handling difficulty.

Description

Technical Field

[0001] This utility model relates to the field of volute casting equipment technology, specifically to a mold for casting thin-walled volutes. Background Technology

[0002] like Figure 4 and Figure 5 As shown, cast steel volutes have the structural characteristics of thin walls, large outline, and nearly closed internal cavities, making them extremely difficult to cast.

[0003] like Figure 6 As shown, the traditional casting process involves setting the core head at the air inlet flange and six points on the inner circular flange of the thin-walled steel volute, and placing the sand core in the inner cavity of the volute. The core head is connected to the sand core through the six points on the inner circular flange. This structural process has significant limitations in terms of casting wall thickness control, internal cavity flaw detection, and defect handling, and will have the following problems: First, due to the connection method between the sand core and the core head, the sand core is a cantilever structure. The connection position is limited by the structure and cannot effectively guarantee the suspension strength of the sand core. After the mold is closed, the cantilever sand core may sink due to its own weight, or it may float during pouring due to the buoyancy of the molten steel. This will lead to the thin-walled volute having an unqualified wall thickness or even wall penetration and scrapping. Second, due to the structural limitations of the sand core and core head, existing grinding and flaw detection equipment cannot achieve complete coverage of the nearly sealed area of ​​the casting's inner cavity.

[0004] Therefore, developing and designing a mold for thin-walled volute casting that has a stable and reliable core structure, will not float or shift during the casting process, and effectively solves the problems of difficult wall thickness control and difficult flaw detection and defect handling in the inner cavity of the casting is an urgent problem to be solved at present. Summary of the Invention

[0005] To address the problems existing in the prior art, this utility model provides a mold for casting thin-walled volutes. The thin-walled volute is split into two halves along the horizontal direction, and each half is cast separately through an upper and lower combined sand box. The core head in the upper and lower combined sand boxes no longer has a cantilever core structure. The core head structure is stable and reliable and will not float or shift during the pouring process. This effectively solves the problems of difficult wall thickness control and difficult flaw detection and defect handling in the casting cavity, reduces casting difficulty, and improves production efficiency.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides a mold for casting a thin-walled volute, wherein the thin-walled volute is composed of an upper half and a lower half of the volute separated along a plane perpendicular to its axis, and includes an upper sand box and a lower sand box: The upper sand box assembly includes a first upper sand box, a first lower sand box, and a first core head. The first upper sand box and the first core head are both placed on the first lower sand box. An annular first pressing surface is formed between the first upper sand box and the first core head. The first upper sand box and the first core head form a first cavity that matches the shape of the upper half of the volute. The first cavity is located within the first pressing surface. A first parting surface is formed between the first upper sand box and the first lower sand box. The first parting surface is lower than the first pressing surface. The first upper sand box and the first core head also form a plurality of first positioning plate cavities. The first positioning plate cavities are connected to the first cavity. The lower sand box assembly includes a second upper sand box, a second lower sand box, and a second core head. The second upper sand box and the second core head are both placed on the second lower sand box. There is an annular second pressing surface between the second upper sand box and the second core head. The second upper sand box and the second core head form a second cavity that matches the shape of the lower half of the volute. The second cavity is located within the second pressing surface. There is a second parting surface between the second upper sand box and the second lower sand box. The second parting surface is lower than the second pressing surface. The second upper sand box and the second core head also form a plurality of second positioning plate cavities. The second positioning plate cavities are connected to the second cavities. The first positioning plate cavity and the second positioning plate cavity correspond one-to-one.

[0007] As a preferred technical solution, the upper surface of the first lower sand box has a first mounting groove, the bottom surface of the first mounting groove is set as a plane, the side surface of the first mounting groove is set as a first inclined surface, and the shape of the lower part of the first core head matches the shape of the first mounting groove.

[0008] As a preferred technical solution, the upper surface of the second lower sand box has a second mounting groove, the bottom surface of the second mounting groove is set as a plane, the side surface of the second mounting groove is set as a second inclined surface, and the shape of the lower part of the second core head matches the shape of the second mounting groove.

[0009] As a preferred technical solution, the cross-sectional areas of both the first mounting groove and the second mounting groove gradually increase from bottom to top; And / or, the inclination angles of the first inclined plane and the second inclined plane are both set to 30-45°.

[0010] As a preferred technical solution, the first core head has a third inclined surface located between the first pressing surface and the first lower sand box, and the shape of the inner wall surface of the first upper sand box corresponding to the third inclined surface matches the third inclined surface.

[0011] As a preferred technical solution, the second core head has a fourth inclined surface located between the second pressing surface and the second lower sand box, and the shape of the inner wall surface of the second upper sand box corresponding to the fourth inclined surface matches the fourth inclined surface.

[0012] As a preferred technical solution, the portion of the first core protruding from the first lower sand box and the portion of the second core protruding from the second lower sand box both gradually decrease in size from bottom to top. And / or, the inclination angles of the third and fourth inclined planes are both set to 30-45°.

[0013] As a preferred technical solution, both the first positioning plate cavity and the second positioning plate cavity are provided with sand columns for forming positioning holes.

[0014] As a preferred technical solution, both the first core head and the second core head are made of resin sand or coated sand.

[0015] As a preferred technical solution, the first cavity and the second cavity are symmetrically arranged.

[0016] The beneficial effects of this utility model are as follows: 1. This utility model splits the thin-walled volute horizontally into two halves: an upper half and a lower half. The upper and lower halves are cast separately using upper and lower sand casting molds, respectively. The cores within these molds no longer have a cantilevered core structure, eliminating the instability and floating / displacement issues associated with cantilevered cores. This effectively solves the problem of difficult wall thickness control. The two-half casting method transforms the nearly sealed inner cavity of the thin-walled volute into an open area, making the casting cavity 100% accessible, observable, and repairable. This solves the problem that traditional grinding and flaw detection equipment cannot completely cover the inner cavity of the casting, reducing casting difficulty and improving production efficiency.

[0017] 2. The core head in the sand box of this utility model has a large contact area with both the upper and lower sand boxes. Furthermore, the pressing surface between the core head and the upper sand box is located above the parting surface between the upper and lower sand boxes, which together form an anti-floating structure to resist the buoyancy of the molten steel on the sand core during the pouring process. This effectively prevents the core head from floating or shifting during the pouring process, ensuring the dimensional accuracy of the casting.

[0018] 3. This utility model uses upper and lower sand molds to cast the upper and lower halves of the volute, respectively, each with a positioning plate. After flaw detection of the upper and lower halves, the positioning plates allow for convenient and precise assembly and welding of the two halves to form a complete thin-walled volute casting. Furthermore, the casting of the upper and lower halves avoids all functional throats and high-pressure areas of the casting, and prevents the formation of parting lines on the surface of the thin-walled volute, reducing the risk of uneven welding shrinkage, significantly improving the surface quality of the casting, and reducing subsequent processing. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a thin-walled volute casting mold according to the present invention; Figure 2 for Figure 1 Enlarged view of region A in the middle; Figure 3 This is a schematic diagram of the upper and lower halves of the volute casing cast according to this utility model. Figure 4 This is a schematic diagram of the structure of a thin-walled volute. Figure 5 for Figure 4 A sectional view; Figure 6 This is a schematic diagram of the structure of a traditional thin-walled volute casting mold.

[0020] In the diagram: 1-First upper sand box, 11-First pressing surface, 2-First lower sand box, 21-First parting surface, 22-First mounting groove, 221-First inclined surface, 3-First core head, 31-Third inclined surface, 4-First cavity, 5-Thin-walled volute, 51-Upper half of volute, 52-Lower half of volute, 53-First positioning plate, 54-Second positioning plate, 55-Positioning pin, 6-Inner circular flange. Detailed Implementation

[0021] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0022] Please refer to Figures 1-5 This is a first embodiment of a mold for casting a thin-walled volute, provided by the present invention, comprising an upper combined sand box and a lower combined sand box; The upper sand box assembly includes a first upper sand box 1, a first lower sand box 2, and a first core head 3. The first upper sand box 1 and the first core head 3 are both placed on the first lower sand box 2. There is an annular first pressing surface 11 between the first upper sand box 1 and the first core head 3. The first upper sand box 1 and the first core head 3 form a first cavity 4 that matches the shape of the upper half 51 of the volute. The first cavity 4 is located inside the first pressing surface 11 and is used to form the upper half 51 of the thin-walled volute 5. There is a first parting surface 21 between the first upper sand box 1 and the first lower sand box 2. The first parting surface 21 is lower than the first pressing surface 11. Since the first cavity 4 is formed only by the first upper sand box 1 and the first core head 3, the first core head 3 will not float during the casting process. The first upper sand box 1 and the first core head 3 also form several first positioning plate cavities. The first positioning plate cavities are connected to the first cavity 4 and are used to form a first positioning plate 53 connected to the upper half 51 of the volute. The structure of the lower combined sand box is the same as that of the upper combined sand box. Specifically, the lower combined sand box includes a second upper sand box, a second core head, and both the second upper sand box and the second core head are placed on the second lower sand box. There is an annular second pressing surface between the second upper sand box and the second core head. The second upper sand box and the second core head form a second cavity that matches the shape of the lower half 52 of the volute. The second cavity is located within the second pressing surface and is used to form the lower half 52 of the thin-walled volute 5. There is a second parting surface between the second upper sand box and the second lower sand box. The second parting surface is lower than the second pressing surface. The second upper sand box and the second core head also form a plurality of second positioning plate cavities. The second positioning plate cavities are connected to the second cavity and are used to form a second positioning plate 54 connected to the lower half 52 of the volute. The first positioning plate cavity and the second positioning plate cavity correspond one-to-one, so that the first positioning plate 53 matches the second positioning plate 54. The first cavity 4 and the second cavity are symmetrically arranged. The upper half 51 and the lower half 52 of the volute shell, which are cast by the upper and lower combined sand boxes respectively, are thin-walled volute shells 5, which are two halves separated by a plane perpendicular to their axis.

[0023] Specifically, please refer to Figure 3 Both the first and second positioning plate cavities are provided with sand columns for forming positioning holes, so that the cast first positioning plate 53 and second positioning plate 54 both have positioning holes. When assembling and welding the upper half 51 and the lower half 52 of the volute, a positioning pin 55 is inserted between the positioning holes of the first positioning plate 53 and the second positioning plate 54, which can effectively position the upper half 51 and the lower half 52 of the volute and make them accurately connected to ensure the welding accuracy. In addition, after assembly and welding, flaw detection should be carried out according to the product design requirements to ensure the bevel quality.

[0024] It should be noted that both the first core head 3 and the second core head are preferably made of resin sand or coated sand, which has good high temperature resistance and dimensional stability, and is suitable for precision casting of thin-walled cast steel volute 5.

[0025] In this embodiment, please refer to Figure 1 and Figure 2 The upper surface of the first lower sand box 2 has a first mounting groove 22. The bottom surface of the first mounting groove 22 is set as a plane, and the side surface of the first mounting groove 22 is set as a first inclined surface 221. The shape of the lower part of the first core head 3 matches the shape of the first mounting groove 22. The first core head 3 and the first lower sand box 2 have a large contact area, which ensures accurate assembly and prevents the first core head 3 from moving relative to the first lower sand box 2.

[0026] Similar to the first lower sand box 2, the upper surface of the second lower sand box has a second mounting groove. The bottom surface of the second mounting groove is set as a plane, and the side surface of the second mounting groove is set as a second inclined surface. The shape of the lower part of the second core head matches the shape of the second mounting groove, and the second core head is stably positioned on the second lower sand box.

[0027] To ensure the stable positioning between the core head and the lower sand box, the cross-sectional area of ​​the first mounting groove 22 and the second mounting groove are preferably gradually increased from bottom to top, i.e., conical, which facilitates assembly and demolding and improves contact sealing.

[0028] Specifically, the inclination angles of both the first inclined plane 221 and the second inclined plane are preferably set to 30-45°.

[0029] Further, please refer to Figure 1 and Figure 2 The first core head 3 is located between the first pressing surface 11 and the first lower sand box 2 and has a third inclined surface 31. The shape of the inner wall surface of the first upper sand box 1 corresponding to the third inclined surface 31 matches the third inclined surface 31. The first core head 3 and the first upper sand box 1 have a large contact area, which ensures accurate assembly and avoids relative movement between the first core head 3 and the first upper sand box 1, preventing the first core head 3 from floating or shifting during the pouring process.

[0030] Similar to the first upper sand box 1, the second core head has a fourth inclined surface located between the second pressing surface and the second lower sand box. The shape of the inner wall surface of the second upper sand box corresponding to the fourth inclined surface matches the fourth inclined surface, which can effectively position the second core head relative to the second upper sand box and prevent the second core head from floating or shifting during the pouring process.

[0031] To ensure a stable relative position between the core head and the upper sand box, the portion of the first core head 3 protruding from the first lower sand box 2 and the portion of the second core head protruding from the second lower sand box are preferably tapered from bottom to top, which facilitates assembly and demolding, improves contact sealing, and prevents molten steel leakage during casting.

[0032] Specifically, the inclination angles of the third inclined plane 31 and the fourth inclined plane are preferably set to 30-45°.

[0033] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. For those skilled in the art, the present utility model can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A mold for casting a thin-walled volute, wherein the thin-walled volute (5) is composed of an upper half (51) and a lower half (52) of the volute separated along a plane perpendicular to its axis, characterized in that, Includes an upper sand box and a lower sand box: The upper sand box assembly includes a first upper sand box (1), a first lower sand box (2), and a first core head (3). The first upper sand box (1) and the first core head (3) are both placed on the first lower sand box (2). There is an annular first pressing surface (11) between the first upper sand box (1) and the first core head (3). The first upper sand box (1) and the first core head (3) form a first cavity (4) that matches the shape of the upper half (51) of the volute. The first cavity (4) is located inside the first pressing surface (11). There is a first parting surface (21) between the first upper sand box (1) and the first lower sand box (2). The first parting surface (21) is lower than the first pressing surface (11). The first upper sand box (1) and the first core head (3) also form a plurality of first positioning plate cavities. The first positioning plate cavities are connected to the first cavity (4). The lower sand box includes a second upper sand box, a second lower sand box, and a second core head. The second upper sand box and the second core head are both placed on the second lower sand box. There is an annular second pressing surface between the second upper sand box and the second core head. The second upper sand box and the second core head form a second cavity that matches the shape of the lower half (52) of the volute. The second cavity is located within the second pressing surface. There is a second parting surface between the second upper sand box and the second lower sand box. The second parting surface is lower than the second pressing surface. The second upper sand box and the second core head also form a plurality of second positioning plate cavities. The second positioning plate cavities are connected to the second cavity. The first positioning plate cavity corresponds to the second positioning plate cavity one by one.

2. The mold for casting a thin-walled volute according to claim 1, characterized in that, The upper surface of the first lower sand box (2) has a first mounting groove (22), the bottom surface of the first mounting groove (22) is set as a plane, the side surface of the first mounting groove (22) is set as a first inclined surface (221), and the shape of the lower part of the first core head (3) matches the shape of the first mounting groove (22).

3. The mold for casting a thin-walled volute according to claim 2, characterized in that, The upper surface of the second lower sand box has a second mounting groove, the bottom surface of the second mounting groove is set as a plane, the side surface of the second mounting groove is set as a second slope, and the shape of the lower part of the second core head matches the shape of the second mounting groove.

4. The mold for casting a thin-walled volute according to claim 3, characterized in that, The cross-sectional areas of the first mounting groove (22) and the second mounting groove gradually increase from bottom to top; And / or, the inclination angles of the first inclined plane (221) and the second inclined plane are both set to 30-45°.

5. A mold for casting a thin-walled volute according to claim 3, characterized in that, The first core head (3) is located between the first pressing surface (11) and the first lower sand box (2) and has a third inclined surface (31). The shape of the inner wall surface of the first upper sand box (1) corresponding to the third inclined surface (31) matches the shape of the third inclined surface (31).

6. A mold for casting a thin-walled volute according to claim 5, characterized in that, The second core head is located between the second pressing surface and the second lower sand box and has a fourth inclined surface. The shape of the inner wall surface of the second upper sand box corresponding to the fourth inclined surface matches the fourth inclined surface.

7. A mold for casting a thin-walled volute according to claim 6, characterized in that, The portion of the first core head (3) protruding from the first lower sand box (2) and the portion of the second core head protruding from the second lower sand box both gradually decrease in size from bottom to top. And / or, the inclination angles of the third inclined plane (31) and the fourth inclined plane are both set to 30-45°.

8. A mold for casting a thin-walled volute according to claim 1, characterized in that, Both the first positioning plate cavity and the second positioning plate cavity are provided with sand columns for forming positioning holes.

9. A mold for casting a thin-walled volute according to claim 1, characterized in that, Both the first core head (3) and the second core head are made of resin sand or coated sand.

10. A mold for casting a thin-walled volute according to claim 1, characterized in that, The first cavity (4) and the second cavity are symmetrically arranged.

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