A heat retaining and generating structure for sand casting

Abstract

The utility model discloses a kind of heat preservation heating structures for sand casting, including riser sleeve and riser nest, riser sleeve and riser nest are made of heat preservation heating material, the inside of riser sleeve is equipped with containing cavity, riser nest is equipped with feeding channel, feeding channel is communicated with containing cavity, and form semi-open feeding channel;One end of riser nest is equipped with arc part, arc part makes its corresponding part feeding channel form transition groove, the rest feeding channel forms conveying groove, transition groove from the end corresponding with containing cavity to the other end reduces, so that the cross section of containing cavity is greater than the cross section area of conveying groove.The utility model proposes that the feeding channel is formed by the riser sleeve and riser nest made of heat preservation heating material, the metal liquid in feeding channel is heated and kept warm, to delay the solidification time of metal liquid, so that feeding channel keeps unobstructed, while also reduce the volume of riser after forming, reduce the waste of casting material, while also reduce the cutting difficulty of riser.

Description

Technical Field

[0001] This utility model belongs to the field of casting, specifically relating to a heat-insulating and heating structure for sand casting. Background Technology

[0002] In existing casting processes, sand casting is widely used in various casting fields due to its advantages such as low cost and high applicability. Existing sand casting typically uses multiple risers around the casting to feed the casting during solidification and prevent the formation of keyholes or shrinkage cavities during solidification. To prevent premature solidification of the high-temperature molten metal within the riser, most existing risers increase their volume, allowing them to hold more molten metal and delaying solidification, thus enabling timely feeding of the casting. However, this method increases the amount of molten metal used in the riser, leading to the need to remove more metal after casting, thus increasing production costs.

[0003] In the prior art, such as patent document CN211304684U, a side riser sleeve is disclosed, including a side riser cavity, which comprises a riser body and a side riser neck, and the lower part of the riser body is spherical. The spherical lower part of the riser body increases the volume of the riser body, thus prolonging the solidification time of the molten metal in the lower part of the side riser body and avoiding premature solidification of the molten metal that would cause feeding of the casting. However, this method increases the amount of molten metal used in the riser body, thereby increasing production costs. Summary of the Invention

[0004] To address the problems in existing technologies, this utility model proposes a heat-insulating and heating structure for sand casting. A feeding channel is formed by a riser sleeve and riser socket made of heat-insulating and heating material. The molten metal within the feeding channel is heated and kept at a constant temperature to delay the solidification time of the molten metal. This ensures that the solidification time of the casting is shorter than that of the molten metal within the feeding channel, guaranteeing that the feeding channel remains unobstructed when the casting requires feeding. Simultaneously, it reduces the volume of the riser after molding, thereby reducing waste of casting materials and lowering the difficulty of cutting the riser.

[0005] This utility model is implemented as follows: a heat-insulating and heat-generating structure for sand casting, disposed on the periphery of the casting, includes a heat-insulating and heat-generating riser sleeve and a riser socket corresponding to the riser sleeve. Both the riser sleeve and the riser socket are made of heat-insulating and heat-generating material. The riser sleeve is hollow inside to form a receiving cavity. The riser sleeve is disposed at one end of the riser socket and is spliced ​​with or integrally formed with the riser socket to form the heat-insulating and heat-generating structure.

[0006] The riser socket has an upward-opening feeding groove that communicates with the receiving cavity to form a semi-open feeding channel. This feeding channel connects to the side of the casting, placing the heat-insulating and heating structure on the side of the casting. This design offers advantages such as flexible positioning, a shorter feeding path, and higher feeding efficiency. The heat-insulating and heating structure is used to insulate the molten metal within the feeding channel, delaying its solidification time. This results in a shorter solidification time for the casting compared to the molten metal within the feeding channel, maintaining the smoothness of the feeding channel without increasing the volume of the heat-insulating socket. Furthermore, since the riser formed within the feeding channel needs to be cut and discarded after casting, extending the solidification time of the molten metal within the feeding channel using heat-insulating and heating materials does not increase the volume of the heat-insulating socket, thus reducing the volume of the riser. This reduces waste of casting materials and simplifies the cutting difficulty of the riser.

[0007] The riser socket has an arc-shaped portion at one end connecting to the riser sleeve. This arc-shaped portion forms an arc-shaped transition groove for a portion of the feeding groove, while the remaining feeding grooves form a transversely arranged conveying groove. The transition groove decreases in size from one end corresponding to the receiving cavity to the other end, making the cross-sectional area of ​​the receiving cavity larger than that of the conveying groove. The receiving cavity and the feeding groove have similar shapes. Under the same insulation conditions, the solidification time of the riser is positively correlated with its cross-sectional area; that is, the larger the cross-sectional area, the longer the solidification time. When the cross-sectional area of ​​the receiving cavity is larger than that of the conveying groove, the molten metal in the riser socket solidifies earlier than the molten metal in the riser sleeve, preventing premature solidification of the molten metal in the riser sleeve and thus avoiding difficulty in the molten metal in the riser socket flowing to the casting, thereby improving the feeding effect.

[0008] Preferably, the riser sleeve is also provided with an air inlet at the top, which connects the receiving cavity to the outside. When the molten metal in the feeding channel feeds the casting, atmospheric pressure can accelerate the flow rate of the molten metal, thereby improving the feeding efficiency.

[0009] Specifically, a core is provided at the top of the receiving cavity, located on one side of the air inlet, and gradually decreasing in size from top to bottom to form a conical cross-section. Because the air inlet connects the receiving cavity to the outside, the molten metal near the air inlet solidifies more easily, forming a hard shell. This isolates the molten metal inside the hard shell from the outside, reducing the feeding efficiency. However, the core has interconnected pores inside, preventing a vacuum from forming inside the receiving cavity after the hard shell is formed. Atmospheric pressure can accelerate the flow rate of the molten metal, thereby improving the feeding efficiency.

[0010] Specifically, the size of the air inlet is in the range of 5-15mm.

[0011] Preferably, the riser sleeve extends longitudinally and the riser socket extends laterally, making the heat-insulating and heating structure L-shaped. The extension dimension of the riser sleeve is greater than the extension dimension of the riser socket, so that the riser sleeve is close to the casting, thereby reducing the volume of the riser formed by the feeding channel, and thus reducing the volume of the cut-off riser, saving casting materials.

[0012] Specifically, the extension length of the riser hole ranges from 90 to 150 mm.

[0013] Preferably, the cross-section of the conveying trough is U-shaped, and the bottom of the riser socket is provided with a horizontally arranged placement surface, and the width of the placement surface is greater than the height of the conveying trough, so that the riser socket structure can stand upright in the installation position, reducing the risk of the heat insulation and heating structure tipping over, and improving the convenience and stability of the heat insulation and heating structure during installation.

[0014] Preferably, the riser sleeve and riser socket have uniform wall thicknesses, resulting in more uniform heat insulation and more uniform solidification of the molten metal within them. This prevents uneven solidification, which could lead to uneven surfaces and increased flow resistance during molten metal feeding, thus improving feeding efficiency. The wall thickness of the riser sleeve and riser socket ranges from 10 to 15 mm.

[0015] Specifically, the receiving cavity gradually decreases in size from bottom to top, giving it a frustum-shaped form that is smaller at the top and larger at the bottom. Since the pressure generated by the liquid is determined by the height of the liquid level, a receiving cavity that gradually decreases in size can save casting materials while keeping the liquid level of the molten metal constant.

[0016] Preferably, the heat-insulating and heating material includes heat-insulating and heating aluminum powder, nutrient supply material, refractory backbone material, and adhesive.

[0017] The beneficial effects of this utility model are:

[0018] This invention proposes a heat-insulating and heating structure for sand casting. On the one hand, by extending the solidification time of the molten metal in the feeding channel through the heat-insulating and heating material, without increasing the volume of the heat-insulating cavity, the volume of the riser is reduced. This reduces the waste of casting materials and also lowers the difficulty of cutting the riser. On the other hand, by making the cross-sectional area of ​​the riser cavity smaller than that of the riser sleeve, the molten metal in the riser cavity solidifies earlier than that in the riser sleeve. This avoids the molten metal in the riser sleeve solidifying too early, which would make it difficult for the molten metal in the riser cavity to flow to the casting, thus improving the feeding effect. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall heat preservation and heating structure of this utility model;

[0020] Figure 2 This is a cross-sectional view of the heat-insulating and heating structure of this utility model;

[0021] Figure 3 This is a schematic diagram of the riser socket of the heat-insulating and heating structure of this utility model;

[0022] Figure 4 This is a schematic diagram showing the use and comparison of the heat preservation and heating structure of this utility model.

[0023] Figure label:

[0024] 1. Riser sleeve; 2. Riser socket; 3. Casting; 11. Receiving cavity; 12. Air inlet; 13. Core; 21. Feeding groove; 22. Arc section; 23. Placement surface; 211. Transition groove; 212. Conveying groove. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] like Figures 1-4 As shown, a heat-insulating and heat-generating structure for sand casting is provided on the periphery of the casting 3, including a heat-insulating and heat-generating riser sleeve 1 and a riser socket 2 corresponding to the riser sleeve 1. Both the riser sleeve 1 and the riser socket 2 are made of heat-insulating and heat-generating material. The riser sleeve 1 is hollow inside, forming a receiving cavity 11. The riser sleeve 1 is provided at one end of the riser socket 2 and is integrally formed with the riser socket 2 to form the heat-insulating and heat-generating structure.

[0027] In this embodiment, the heat-insulating and heating material is made of heat-insulating and heating aluminum powder, nutrient supply material, refractory backbone material and adhesive.

[0028] In this embodiment, the riser sleeve 1 and riser socket 2 have uniform wall thicknesses, resulting in more uniform heat insulation and more uniform solidification of the molten metal within them. This prevents uneven solidification of the molten metal, which would create uneven protrusions, increasing the flow resistance during molten metal feeding and improving feeding efficiency. The wall thickness of the riser sleeve 1 and riser socket 2 is 12.5 mm.

[0029] Specifically, the receiving cavity 11 gradually decreases in size from bottom to top, making it a frustum-shaped structure with a smaller top and a larger bottom. Since the pressure generated by the liquid is determined by the height of the liquid surface, the receiving cavity 11, which increases in size from bottom to top, can save casting materials while keeping the liquid level of the molten metal constant.

[0030] The riser socket 2 is provided with an upward-opening feeding groove 21, which communicates with the receiving cavity 11 to form a semi-open feeding channel. The feeding channel is connected to the side of the casting 3, so that the heat-insulating and heating structure is located on the side of the casting 3, which has the advantages of flexible positioning, shorter feeding path, and higher feeding efficiency. The heat-insulating and heating structure is used to keep the molten metal in the feeding channel warm, delaying the solidification time of the molten metal in the feeding channel, so that the solidification time of the casting 3 is shorter than that of the molten metal in the feeding channel. It can maintain the smoothness of the feeding channel without increasing the volume of the heat-insulating socket. At the same time, since the riser formed in the feeding channel needs to be cut and discarded after the casting 3 is formed, the solidification time of the molten metal in the feeding channel is extended by the heat-insulating and heating material without increasing the volume of the heat-insulating socket, thereby reducing the volume of the riser. This reduces the waste of casting materials and also reduces the difficulty of cutting the riser.

[0031] In this embodiment, the riser sleeve 1 extends longitudinally and the riser socket 2 extends laterally, making the heat-insulating and heating structure L-shaped. The extension dimension of the riser sleeve 1 is greater than the extension dimension of the riser socket 2, so that the riser sleeve 1 is close to the casting 3, thereby reducing the volume of the riser formed by the feeding channel, and thus reducing the volume of the cut-off riser, saving casting materials.

[0032] Specifically, the extension length of the riser socket 2 is 102.5 mm.

[0033] The riser socket 2, connected to the riser sleeve 1, has an arc-shaped portion 22 at one end. This arc-shaped portion 22 forms a portion of the feeding groove 21 into an arc-shaped transition groove 211, while the remaining feeding grooves 21 form a transversely arranged conveying groove 212. The transition groove 211 decreases in size from one end corresponding to the receiving cavity 11 to the other end, making the cross-sectional area of ​​the receiving cavity 11 larger than that of the conveying groove 212. The receiving cavity 11 and the feeding groove 21 have similar shapes. Under the same insulation conditions, the solidification time of the riser is positively correlated with the cross-sectional area; that is, the larger the cross-sectional area, the longer the solidification time. When the cross-sectional area of ​​the receiving cavity 11 is larger than that of the conveying groove 212, the molten metal in the riser socket 2 can solidify earlier than the molten metal in the riser sleeve 1, preventing premature solidification of the molten metal in the riser sleeve 1 and thus avoiding difficulty in the molten metal in the riser socket 2 flowing to the casting 3, thereby improving the feeding effect.

[0034] In this embodiment, the riser sleeve 1 is also provided with an air inlet 12 at the top. The air inlet 12 connects the receiving cavity 11 and the outside. When the molten metal in the feeding channel feeds the casting 3, the flow rate of the molten metal can be accelerated by atmospheric pressure, thereby improving the feeding efficiency.

[0035] Specifically, the top of the receiving cavity 11 is provided with a core 13, which is located on one side of the air inlet 12 and gradually decreases in size from top to bottom, making its cross-section conical. Since the air inlet 12 connects the receiving cavity 11 to the outside, the molten metal near the air inlet 12 is more likely to solidify, forming a hard shell. This isolates the molten metal inside the hard shell from the outside, reducing the feeding efficiency. However, the core 13 has interconnected pores inside, preventing a vacuum from forming inside the receiving cavity 11 after the hard shell is formed. This allows atmospheric pressure to accelerate the flow rate of the molten metal, thereby improving the feeding efficiency.

[0036] Specifically, the size of the air inlet 12 is 10mm.

[0037] In this embodiment, the cross-section of the conveying trough 212 is U-shaped, and the bottom of the riser socket 2 is provided with a horizontally arranged placement surface 23. The width of the placement surface 23 is greater than the height of the conveying trough 212, so that the riser socket 2 structure can stand upright in the installation position, reducing the risk of the heat insulation and heating structure tipping over and improving the convenience and stability of the heat insulation and heating structure during installation.

[0038] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the utility model should also fall within the protection scope of the claims of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model.

Claims

1. A heat-insulating and heat-generating structure for sand casting, disposed on the periphery of a casting, comprising a heat-insulating and heat-generating riser sleeve and a riser recess corresponding to the riser sleeve, wherein both the riser sleeve and the riser recess are made of heat-insulating and heat-generating material, characterized in that: The riser sleeve is hollow inside, forming a receiving cavity. The riser sleeve is located at one end of the riser socket and is spliced ​​with or integrally formed with the riser socket to form the heat-insulating and heating structure. The riser socket is provided with an upward-opening feeding groove, which is connected to the receiving cavity to form a semi-open feeding channel, and the feeding channel is connected to the side of the casting. The riser socket is connected to the riser sleeve at one end with an arc-shaped portion. The arc-shaped portion forms an arc-shaped transition groove for the corresponding part of the feeding groove, and the remaining feeding groove forms a transversely arranged conveying groove. The transition groove decreases from one end corresponding to the receiving cavity to the other end, so that the cross-section of the receiving cavity is larger than the cross-sectional area of ​​the conveying groove.

2. The heat-insulating and heating structure for sand casting according to claim 1, characterized in that: The top of the riser sleeve is also provided with an air inlet, which connects the receiving cavity to the outside.

3. The heat-insulating and heating structure for sand casting according to claim 2, characterized in that: The top of the receiving cavity is provided with a core, which is located on one side of the air inlet and gradually decreases in size from top to bottom, making its cross-section conical.

4. The heat-insulating and heating structure for sand casting according to claim 2, characterized in that: The size of the air inlet is in the range of 5-15mm.

5. The heat-insulating and heating structure for sand casting according to claim 1, characterized in that: The riser sleeve extends longitudinally, and the riser socket extends laterally, making the heat-insulating and heating structure L-shaped. The extension dimension of the riser sleeve is greater than the extension dimension of the riser socket, so that the riser sleeve is close to the casting.

6. The heat-insulating and heating structure for sand casting according to claim 5, characterized in that: The length of the riser hole ranges from 90 to 150 mm.

7. The heat-insulating and heating structure for sand casting according to claim 1, characterized in that: The conveying trough has a U-shaped cross-section, and the bottom of the riser socket has a horizontally arranged placement surface, the width of which is greater than the height of the conveying trough.

8. The heat-insulating and heating structure for sand casting according to claim 1, characterized in that: The riser sleeve and riser socket have uniform wall thicknesses, ranging from 10 to 15 mm.

9. A heat-insulating and heating structure for sand casting according to claim 4, characterized in that: The cavity gradually decreases in size from bottom to top, giving it a frustum shape that is smaller at the top and larger at the bottom.

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