Combined sand core structure for shell casting

Abstract

This utility model relates to a combined conformal sand core structure for pressure shell casting, comprising a first sand core shell, a second sand core shell, and a locking pin. The two sand core shells are fastened together to form a composite body. The first sand core shell has a first positioning part on its edge, and the second sand core shell has a second positioning part on its edge that cooperates with the first positioning part. The first sand core shell has at least one set of first grooves on its edge, each groove having a set of opposing first inclined walls, making the first groove a trapezoidal shape that gradually narrows from the bottom to the top. The second sand core shell has at least one set of second grooves on its edge, each groove having a set of opposing second inclined walls, making the second groove a trapezoidal shape that gradually narrows from the bottom to the top. After the two sand core shells are fastened together, the two grooves align to form a double dovetail hole that is narrow in the middle and wide at both ends. The locking pin is used to insert into the double dovetail hole and engage with it through an inclined surface to lock the two sand core shells together. This solves the technical problems of cumbersome locking operation and poor locking effect in the prior art.

Description

Technical Field

[0001] This utility model relates to the field of conformal sand core technology, and in particular to a combined conformal sand core structure for press-shell casting. Background Technology

[0002] The intermediate shell of an automotive turbocharger housing connects the turbine and compressor to form a complete turbocharging system, while also serving as a support and bearing housing. Intermediate shell products are typically large in size and have irregular internal shapes, thus requiring the use of large sand cores for their internal structure. When using membrane sand molding for the sand core, to avoid excessive weight of the internal sand core and to facilitate sand core venting, the conformal sand core is molded according to the shape of the casting's internal cavity, dividing it into upper and lower halves before assembly.

[0003] In existing technologies, the main methods for assembling upper and lower halves of conformal sand cores include: First, directly applying adhesive to the surface of the sand core to bond the two cores together. This method consumes a large amount of adhesive, and due to the long adhesive application area on the sand core, the labor intensity is high. The curing time for the adhesive after assembly is also long, making it unusable for short periods and unfavorable for continuous production. Second, using bolts to fix the two sand cores. This method requires the bolts and nuts to be retrieved from one end. To facilitate retrieval and prevent them from being encased in aluminum, small sand cores are used as plugs to cover the bolts. Furthermore, different products use different bolt specifications, requiring the configuration of various bolt sizes, increasing the difficulty of on-site management. Additionally, the strength of the bolts is much greater than that of the sand cores themselves; if the torque is too high during tightening, the sand core is prone to breakage, while if the torque is too low, the sand core will not be properly locked. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a combined conformal sand core structure for pressure shell casting, which solves the technical problems of cumbersome locking operation and poor locking effect in existing technologies.

[0005] The technical solution adopted in this utility model is as follows:

[0006] A composite conformal sand core structure for press-shell casting includes a first sand core shell and a second sand core shell. The first sand core shell and the second sand core shell are fastened together to form a composite body. The edge of the first sand core shell is provided with a first positioning part, and the edge of the second sand core shell is provided with a second positioning part that cooperates with the first positioning part.

[0007] The edge of the first sand core shell is provided with at least one set of first grooves, and the first groove has a set of opposing first inclined walls, so that the first groove is a trapezoid that gradually narrows from the bottom to the top of the groove;

[0008] The edge of the second sand core shell is provided with at least one set of second grooves, and the second grooves have a set of opposing second inclined walls, so that the second grooves are trapezoidal that gradually narrows from the bottom to the top of the groove;

[0009] After the first sand core shell and the second sand core shell are fastened together, the second groove aligns with the first groove to form a double dovetail-shaped hole that is narrow in the middle and wide at both ends.

[0010] It also includes a locking pin, which matches the inner contour of the double dovetail hole, and is used to insert into the double dovetail hole and engage with it through an inclined surface to lock the first sand core shell and the second sand core shell.

[0011] The preferred technical solution is as follows:

[0012] The locking pin has an upper inclined wall at one end and a lower inclined wall at the other end. The upper inclined wall cooperates with the first inclined wall, and the lower inclined wall cooperates with the second inclined wall.

[0013] The first inclined wall and the second inclined wall, which are arranged opposite to each other, are symmetrical.

[0014] The set of oppositely arranged first inclined walls are symmetrical to each other; the set of oppositely arranged first inclined walls are symmetrical to each other.

[0015] The first sand core shell has a cavity, and the cavity is provided with reinforcing ribs that form a grid pattern distributed horizontally and vertically.

[0016] The second sand core shell has a cavity, and the cavity is provided with reinforcing ribs that form a grid pattern distributed horizontally and vertically.

[0017] The first sand core shell and / or the second sand core shell are provided with venting grooves on their mating surfaces.

[0018] The locking pin is formed using coated sand molding.

[0019] The locking pin, the first sand core shell, and the second sand core shell are prepared using the same coated sand.

[0020] The first positioning part includes a first stepped surface, which is distributed around the edge of the first sand core shell; the second positioning part includes a second stepped surface that mates with the first stepped surface, which is distributed around the edge of the second sand core shell.

[0021] The technical solution of this utility model can achieve at least some of the following beneficial effects:

[0022] This invention features trapezoidal grooves at the edges of the first and second sand core shells, which together form a double dovetail hole. The two sand core shells can be locked together by inserting a locking pin. The locking pin is part of the sand core, forming the overall structure of the combined sand core. No bolts, nuts, or adhesives are needed, which is beneficial for continuous production and improves production efficiency.

[0023] The locking pin and corresponding double dovetail hole of this utility model are characterized by being narrow in the middle and wide at both ends. By using a single locking pin, the first and second sand cores can be prevented from separating in opposite directions at the same time. The structure is reasonable and novel, and it is applicable to sand core products of various specifications. It has strong applicability and is convenient for on-site management.

[0024] The locking pin of this utility model can be simultaneously formed using the same type of coated sand for the first and second sand core shells, making it simple to manufacture and low in cost.

[0025] Other features and advantages of this invention will be set forth in the following description or may be learned by practicing this invention. Attached Figure Description

[0026] Figure 1 This is a three-dimensional structural diagram of the core assembly state in an embodiment of this utility model.

[0027] Figure 2 This is a schematic diagram of the structure of the first sand core shell in an embodiment of this utility model.

[0028] Figure 3 for Figure 2 Enlarged view of section A.

[0029] Figure 4 This is a schematic diagram of the structure of the second sand core shell in an embodiment of this utility model.

[0030] Figure 5 for Figure 4 Enlarged view of section B in the middle.

[0031] Figure 6 This is a schematic diagram of the structure of the locking pin in an embodiment of this utility model.

[0032] Explanation of reference numerals in the attached drawings: 1. First sand core shell; 2. Second sand core shell; 3. Pin; 4. Reinforcing rib; 5. Core assembly tooling; 6. Venting groove; 11. First groove; 21. Second groove; 31. Upper inclined wall; 32. Lower inclined wall; 101. First step surface; 111. First inclined wall; 201. Second step surface; 211. Second inclined wall. Detailed Implementation

[0033] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0034] See Figures 1 to 6 As shown, the combined conformal sand core structure for press shell casting in this embodiment includes a first sand core shell 1 and a second sand core shell 2. The first sand core shell 1 and the second sand core shell 2 are fastened together to form a composite body. The edge of the first sand core shell 1 is provided with a first positioning part, and the edge of the second sand core shell 2 is provided with a second positioning part that cooperates with the first positioning part.

[0035] The edge of the first sand core shell 1 is provided with at least one set of first grooves 11, and the first groove 11 has a set of opposing first inclined walls 111, so that the first groove 11 is a trapezoid that gradually narrows from the bottom to the top of the groove;

[0036] The edge of the second sand core shell 2 is provided with at least one set of second grooves 21. The second groove 21 has a set of opposing second inclined walls 211, so that the second groove 21 is a trapezoid that gradually narrows from the bottom to the top of the groove.

[0037] After the first sand core shell 1 and the second sand core shell 2 are fastened together, the second groove 21 is connected with the first groove 11 to form a double dovetail hole that is narrow in the middle and wide at both ends.

[0038] The combined conformal sand core structure for press shell casting in this embodiment also includes a locking pin 3, which matches the inner contour of the double dovetail hole and is used to insert into the double dovetail hole and engage with it through the inclined surface to lock the first sand core shell 1 and the second sand core shell 2.

[0039] In a specific implementation, the locking pin 3 has an upper inclined wall 31 arranged opposite to each other at one end and a lower inclined wall 32 arranged opposite to each other at the other end. The upper inclined wall 31 cooperates with the first inclined wall 111, while the lower inclined wall 32 cooperates with the second inclined wall 211.

[0040] As a preferred embodiment, the core assembly process includes: placing the second sand core shell 2 onto the core assembly fixture 5 for positioning; then, closing the first sand core shell 1 from above along the core assembly surface with the second sand core shell 2, wherein the core assembly surface includes the mating surface of the first positioning part and the second positioning part; and then inserting a locking pin 3 into the double dovetail-shaped hole formed after the two sand core shells are closed, as shown below. Figure 1 As shown. Specifically, the locking pin 3 is inserted into the double dovetail hole, and its outer wall is flush with the outer walls of the first sand core shell 1 and the second sand core shell 2, forming part of the combined freeform sand core.

[0041] Specifically, when the first sand core shell 1 is moved upward, the upper inclined wall 31 of the locking pin 3 engages with the first inclined wall 111 of the first groove 11, and is limited by the upper inclined wall 31, preventing the first inclined wall 111 from moving and thus preventing the first sand core shell 1 from detaching upward. Similarly, when the second sand core shell 2 is moved downward, the lower inclined wall 32 of the locking pin 3 engages with the second inclined wall 211 of the second groove 21, and is limited by the lower inclined wall 32, preventing the second inclined wall 211 from moving and thus preventing the second sand core shell 2 from detaching downward, thereby locking the first sand core shell 1 and the second sand core shell 2. This locking structure has high stability, is easy to operate, does not require the use of curing adhesive, and is beneficial to improving efficiency and reducing labor intensity.

[0042] As a preferred embodiment, the set of oppositely arranged first inclined walls 111 and the set of oppositely arranged second inclined walls 211 are symmetrical to each other.

[0043] As a preferred embodiment, the set of oppositely arranged first inclined walls 111 are symmetrical to each other.

[0044] As a preferred embodiment, the set of oppositely arranged first inclined walls 111 are symmetrical to each other.

[0045] As a preferred embodiment, a cavity is formed inside the first sand core shell 1, and reinforcing ribs 4 are provided inside the cavity, forming a grid pattern distributed horizontally and vertically.

[0046] As a preferred embodiment, a cavity is formed inside the second sand core shell 2, and reinforcing ribs 4 are provided inside the cavity, forming a grid pattern distributed horizontally and vertically.

[0047] The recessed cavity design prevents the sand core from becoming too heavy and facilitates venting. The use of a mesh-like reinforcing rib structure increases the strength of the sand core while reducing the amount of coated sand required for preparation. The average wall thickness of the first sand core shell 1 and the second sand core shell 2 is preferably approximately 12 mm.

[0048] As a preferred embodiment, the first sand core shell 1 and / or the second sand core shell 2 are provided with venting grooves 6 on their mating surfaces. This improves the venting performance of the combined sand core.

[0049] As a preferred method, the pin 3 is formed by coated sand molding.

[0050] As a preferred method, the pin 3, the first sand core shell 1 and the second sand core shell 2 are made of the same coated sand, and preferably are made using the same sand making mold.

[0051] As a preferred embodiment, the first positioning part includes a first stepped surface 101, which is distributed around the edge of the first sand core shell 1; the second positioning part includes a second stepped surface 201 that mates with the first stepped surface 101, which is distributed around the edge of the second sand core shell 2. Through the guidance and positioning of the stepped surfaces, precise alignment can be ensured when the two sand core shells are closed, and the "Z"-shaped cross-section of the stepped surfaces increases the contact area.

[0052] As a preferred embodiment, each set of the first groove 11 (second groove 21) includes two spaced apart. Depending on actual needs, a set of first grooves 11 (second grooves 21) can be provided on each side of the sand core. This ensures that the two sand core shells are locked at each side and angle, thereby further improving the uniformity of force on the combined sand core and the stability of the combined structure after locking.

[0053] In this embodiment, the two sand core shells can be locked by inserting a locking pin into a double dovetail hole. The locking pin, as part of the sand core, forms the overall structure of the combined sand core. No bolts, nuts, or adhesives are required, which is conducive to continuous production and improves production efficiency.

[0054] It will be understood by those skilled in the art that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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 composite conformal sand core structure for pressure casting, comprising a first sand core shell (1) and a second sand core shell (2), wherein the first sand core shell (1) and the second sand core shell (2) are fastened together to form a composite body, characterized in that, The first sand core shell (1) has a first positioning part on its edge, and the second sand core shell (2) has a second positioning part on its edge that cooperates with the first positioning part; The first sand core shell (1) has at least one set of first grooves (11) on its edge. The first groove (11) has a set of opposing first inclined walls (111) so that the first groove (11) is a trapezoid that gradually narrows from the bottom to the top. The edge of the second sand core shell (2) is provided with at least one set of second grooves (21), and the second groove (21) has a set of opposing second inclined walls (211), so that the second groove (21) is a trapezoid that gradually narrows from the bottom to the top of the groove; After the first sand core shell (1) and the second sand core shell (2) are fastened together, the second groove (21) is connected to the first groove (11) to form a double dovetail hole that is narrow in the middle and wide at both ends; It also includes a locking pin (3), which matches the inner contour of the double dovetail hole and is used to insert into the double dovetail hole and engage with it through a bevel to lock the first sand core shell (1) and the second sand core shell (2).

2. The combined conformal sand core structure for pressure shell casting according to claim 1, characterized in that, The latch has an upper inclined wall (31) at one end and a lower inclined wall (32) at the other end. The upper inclined wall (31) cooperates with the first inclined wall (111), while the lower inclined wall (32) cooperates with the second inclined wall (211).

3. The combined conformal sand core structure for pressure shell casting according to claim 1, characterized in that, The first inclined wall (111) and the second inclined wall (211) arranged opposite to each other are symmetrical.

4. The combined conformal sand core structure for pressure shell casting according to claim 1 or 3, characterized in that, The set of oppositely arranged first inclined walls (111) are symmetrical to each other; the set of oppositely arranged first inclined walls (111) are symmetrical to each other.

5. The combined conformal sand core structure for pressure shell casting according to claim 1, characterized in that, The first sand core shell (1) has a cavity, and the cavity is provided with reinforcing ribs (4) that form a grid pattern distributed horizontally and vertically.

6. The combined conformal sand core structure for pressure shell casting according to claim 1, characterized in that, The second sand core shell (2) has a cavity, and the cavity is provided with reinforcing ribs (4) that form a grid pattern distributed horizontally and vertically.

7. The combined conformal sand core structure for pressure shell casting according to claim 1, characterized in that, The first sand core shell (1) and / or the second sand core shell (2) are provided with venting grooves (6) on their mating surfaces.

8. The combined conformal sand core structure for pressure shell casting according to claim 1, characterized in that, The locking pin (3) is formed by coated sand molding.

9. The combined conformal sand core structure for pressure shell casting according to claim 1, characterized in that, The locking pin (3), the first sand core shell (1), and the second sand core shell (2) are prepared and shaped using the same coated sand.

10. The combined conformal sand core structure for pressure shell casting according to claim 1, characterized in that, The first positioning part includes a first stepped surface (101) which is distributed around the edge of the first sand core shell (1); the second positioning part includes a second stepped surface (201) which is in concave-convex cooperation with the first stepped surface (101) and is distributed around the edge of the second sand core shell (2).

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