Liquid metal casting mold

Abstract

The utility model discloses a liquid metal casting mold which comprises a mold cavity, a groove body with an upward opening, a through hole formed in the bottom of the groove body, and a truncated cone-shaped inner space with a downward tip end limited by the through hole. The casting block is in the shape of a truncated cone with the tip facing downwards and makes close contact with the through hole, at the normal temperature, the upper surface of the casting block is equal to the height of the groove bottom of the mold cavity, and the lower surface of the casting block is not lower than the lower surface of the mold cavity; and the ratio of the height difference of the two to the depth of the through hole of the mold cavity is less than or equal to 30%. The liquid metal casting mold is long in service life, simple in structure, stable, reliable and convenient to maintain.

Description

Technical Field

[0001] This utility model relates to a liquid metal casting mold. Background Technology

[0002] During the casting process of liquid metal, the high-temperature liquid metal will scour the bottom of the mold, reducing the mold's lifespan.

[0003] CN219425589U proposes a combined casting mold, comprising a mold base structure and a mold saddle structure. The mold base structure is located at the lower end of the mold saddle structure, and the mold base structure and the mold saddle structure are connected by screws for positioning. During molten iron casting, only the mold saddle structure is scoured; when the mold saddle structure is scoured through, only the mold saddle structure needs to be replaced, and the mold base structure does not need to be replaced. This combined casting mold structure is relatively complex, and its installation and maintenance are cumbersome. Utility Model Content

[0004] This invention provides a liquid metal casting mold.

[0005] The technical solution of this utility model is as follows: A liquid metal casting mold includes: a mold cavity, which is an upward-opening groove, with a through hole at the bottom of the groove, the through hole defining a truncated cone-shaped internal space with the tip pointing downward; and a casting block, which is a truncated cone shape with the tip pointing downward and is in close contact with the through hole.

[0006] Wherein, at room temperature, the upper surface of the casting block is at the same height as the bottom of the mold cavity, the lower surface of the casting block is not lower than the lower surface of the mold cavity, and the ratio of the height difference between the two to the depth of the through hole in the mold cavity is less than or equal to 30%.

[0007] The ambient temperature in this invention is 20 to 25°C.

[0008] Optionally, the cross-section of the casting block is circular or regular polygonal, and the cross-section is parallel to the plane of the mold cavity.

[0009] Optionally, in a cross section passing through the centerline of the casting block, the intersection of the side surface of the casting block and the cross section is a first line segment, and the intersection of the upper surface of the casting block and the cross section is a second line segment, with the included angle between the first line segment and the second line segment in the range of 30° to 80°.

[0010] Optionally, in a cross section passing through the centerline of the casting block, the intersection of the side surface of the casting block and the cross section is a first line segment, and the intersection of the upper surface of the casting block and the cross section is a second line segment, with the included angle between the first line segment and the second line segment in the range of 40° to 70°.

[0011] Optionally, at room temperature, the lower surface of the casting block is flush with the lower surface of the mold cavity.

[0012] Optionally, the ratio of the area of ​​the upper surface of the casting block to the area of ​​the upper opening of the mold cavity is 20% to 50%.

[0013] Optionally, the bottom of the interior space of the mold cavity is planar.

[0014] Optionally, the bottom of the internal space of the mold cavity is rectangular or circular.

[0015] Optionally, the mold cavity may further include an ear extending outward from the top of the groove.

[0016] Optionally, the line connecting the geometric center of the casting block and the geometric center of the opening of the mold cavity is perpendicular to the plane where the mold cavity is located.

[0017] Liquid metal casting molds have a long service life, simple structure, stable and reliable operation, are easy to maintain, and are portable. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of a liquid metal casting mold according to this utility model.

[0019] Figure 2 yes Figure 1 The top view of the liquid metal casting mold shown.

[0020] Figure 3 This is a cross-sectional view of another liquid metal casting mold of this utility model.

[0021] The attached diagram is labeled as follows: 1. Casting block; 2. Mold cavity; 21. Ear; L1. First line segment; L2. Second line segment. Detailed Implementation

[0022] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0023] Note: The vertical relationship described in this utility model refers to the positional relationship of the mold when it is in use.

[0024] The liquid metal casting mold of this invention includes a mold cavity and a casting block. The components are described in detail below.

[0025] <Mold Cavity>

[0026] The mold cavity is an upward-opening groove with a through hole at the bottom, which defines a truncated cone-shaped internal space with its tip pointing downwards. The mold cavity is used to contain molten metal and cool it to shape.

[0027] In some embodiments, the size of the upper opening of the mold cavity is larger than the size of the opening at the bottom of the internal space of the mold cavity. Specifically, the orthographic projection of the upper opening of the mold cavity onto the plane of the mold cavity covers and extends beyond the orthographic projection of the bottom of the internal space of the mold cavity onto the plane of the mold cavity. A non-overlapping area is left between these two orthographic projections.

[0028] In some embodiments, the bottom of the interior space of the mold cavity is planar.

[0029] In some embodiments, the bottom of the mold cavity interior space is rectangular or circular. In other embodiments, the bottom of the mold cavity interior space has other customer-customized shapes.

[0030] In some embodiments, the lower surface of the mold cavity and the bottom plane of the internal space of the mold cavity are arranged parallel to each other, and the distance between the two planes is a first dimension. The maximum lateral distance between the inner peripheral surface and the outer peripheral surface of the mold cavity in the direction perpendicular to the central axis of the internal space of the mold cavity is a second dimension. The first dimension is greater than the second dimension, and this design can extend the service life of the mold cavity.

[0031] In some embodiments, the cross-section of the internal space of the through hole in the mold cavity is circular or a regular polygon. This design results in a more uniform distribution of internal forces within the mold cavity during collisions or contractions.

[0032] The mold cavity material must have a high melting point and strong heat exchange efficiency, as well as a certain strength, while also being inexpensive and easy to process. Generally, cast iron is recommended as the mold cavity material.

[0033] In some embodiments, the mold cavity further includes an ear extending outward from the top of the groove. The ear is designed to facilitate manual or mechanical grasping and transfer of the mold cavity.

[0034] The ears can be flat or curved, hook-shaped, or any other shape that is easy to grasp.

[0035] In some embodiments, there are two ears, and the line connecting the centers of the two ears passes through and is perpendicular to the center line of the internal space of the mold cavity.

[0036] <Casting Block>

[0037] The casting block is shaped like a truncated cone with its pointed end facing downwards, making close contact with the bottom through-hole of the mold cavity. The cone can be either a cone or a pyramid. During assembly, the casting block is placed into the through-hole of the mold cavity. During transportation, the casting block remains stably within the mold cavity.

[0038] During casting, high-temperature molten metal is poured directly onto the casting block, which is only eroded. When the casting block is significantly deformed by the erosion, it can be replaced with a new one. This design reduces the material cost of the mold. A through-hole is provided at the bottom of the mold cavity, allowing the casting block to be easily removed by striking it from the lower opening of the through-hole.

[0039] Throughout the casting process, even if the coefficients of thermal expansion of the casting block and the mold cavity are different, the casting block will move upwards appropriately due to its greater expansion than the mold cavity, or downwards appropriately due to its greater contraction than the mold cavity. This ensures that the outer circumferential surface of the casting block remains in close contact with the inner circumferential surface of the bottom through-hole of the mold cavity. The casting process is stable and reliable.

[0040] The casting material must have a high melting point and high heat transfer efficiency. Molybdenum, tantalum, and tungsten are generally recommended materials for casting.

[0041] In some embodiments, the cross-section of the casting block is circular or a regular polygon, and this cross-section is parallel to the plane of the mold cavity. This design facilitates the processing of the casting block and results in more uniform deformation.

[0042] In some embodiments, in a cross section passing through the centerline of the truncated cone, the intersection of the side surface of the truncated cone and the cross section is a first line segment, and the intersection of the upper surface of the truncated cone and the cross section is a second line segment, with the included angle between the first line segment and the second line segment ranging from 30° to 80°.

[0043] The lower surface area and thickness of the truncated cone are fixed. If the angle is too large, the upper surface area of ​​the truncated cone will be too small, and the high-temperature molten metal will easily be poured into the mold cavity. If the angle is too small, the upper surface size of the casting block will be too large, resulting in an excessively large volume of the casting block and excessive material costs.

[0044] More preferably, the included angle is 40° to 70°.

[0045] In some embodiments, at room temperature, the lower surface of the casting block is flush with the lower surface of the mold cavity. This design allows for a maximum casting block thickness and a maximum service life.

[0046] In some other embodiments, at room temperature, the lower surface of the casting block is slightly higher than the lower surface of the mold cavity. At high temperatures, this prevents the casting block from shrinking relative to the casting mold and bulging downwards out of the mold cavity.

[0047] If, at high temperatures, the casting block expands relative to the casting mold and protrudes upwards from the mold cavity, its impact on the shape of the cast metal after molding can be ignored.

[0048] In summary, at room temperature, the lower surface of the casting block should not be lower than the lower surface of the mold cavity, and the vertical distance between them should be less than or equal to 30% of the depth of the through hole in the mold cavity (i.e., the thickness of the bottom of the mold cavity). If this distance is too large, the casting block will be too thin, and the service life of the casting block will be too short.

[0049] In some embodiments, the ratio of the area of ​​the upper surface of the casting block to the area of ​​the upper opening of the mold cavity is 20% to 50%.

[0050] If the upper surface area of ​​the casting block is too small, it will easily erode the mold cavity during the casting process. If the upper surface area of ​​the casting block is too large, it will increase material costs.

[0051] The materials for the casting blocks and mold cavities can be selected independently, thus adapting to the casting of different types of metals.

[0052] Example 1

[0053] refer to Figure 1 and Figure 2 Embodiment 1 of this utility model provides a liquid metal casting mold, including: a mold cavity 2, which is an upward-opening groove with a through hole at the bottom of the groove, the through hole defining a truncated cone-shaped internal space with the tip pointing downward; and a casting block 1, which is a truncated cone-shaped structure with the tip pointing downward and is in close contact with the through hole.

[0054] Specifically, the cross-section of casting block 1 is circular (at this time, casting block 1 is in the shape of a frustum), and the cross-section is parallel to the plane where mold cavity 2 is located. Mold cavity 2 is usually placed horizontally, and the plane where mold cavity 2 is located is a horizontal plane.

[0055] This design makes it easier to process.

[0056] Specifically, at the cross-section passing through the centerline of the truncated cone (reference) Figure 1 In the cross section shown, the intersection of the side surface of the truncated cone with the cross section is the first line segment L1, and the intersection of the upper surface of the truncated cone with the cross section is the second line segment L2. The angle α between the first line segment L1 and the second line segment L2 is in the range of 30° to 80°, and is approximately 60°.

[0057] Specifically, the mold cavity 2 also includes an ear 21 extending outward from the top of the groove. The ear 21 is designed to facilitate manual or mechanical grasping and transfer of the mold cavity 2. The ear 21 is flat and parallel to the plane of the mold cavity 2.

[0058] By adopting the above technical solution, the casting block 1 can be easily placed into the mold cavity 2 to form a complete mold for casting. It is not easily separated from the mold cavity 2 during normal movement. During casting, the deformation of the casting block 1 and the mold cavity 2 caused by the different coefficients of thermal expansion can be adaptively adjusted by the vertical displacement of the casting block 1.

[0059] Specifically, refer to Figure 2 The line connecting the geometric center of the casting block 1 and the geometric center of the opening of the mold cavity 2 is perpendicular to the plane where the mold cavity 2 is located. The bottom of the mold cavity 2 is rectangular, and the ear 21 is located on the short side of the rectangle.

[0060] refer to Figure 1 The vertical cross-section of the internal space of mold cavity 2 is trapezoidal. This vertical cross-section is perpendicular to the plane where mold cavity 1 is located.

[0061] With this design, when the casting block 1 is compressed due to thermal expansion and contraction, the force is more even and it tends to move up and down.

[0062] Example 2

[0063] refer to Figure 3 The difference between the liquid metal casting mold in Example 2 and that in Example 1 is that the lower surface of the casting block 1 is higher than the lower surface of the mold cavity 2, and the ratio of the height difference between the two to the depth of the through hole in the mold cavity 2 is about 27%.

[0064] Application examples

[0065] See Figure 1 as well as Figure 2 The casting block 1 is tightly fitted to the mold cavity 2 to complete the assembly of the casting mold.

[0066] (1) Load industrial-grade La metal (melting point 921℃) into the crucible in the vacuum induction furnace and place the casting mold in the fixed casting position. Close the furnace cover, turn on the furnace water cooling pump, start the mechanical pump, open the roughing valve, and turn on the Roots pump after the vacuum degree reaches the requirements of the Roots pump. After the vacuum degree in the furnace reaches 1~10Pa, close the roughing valve, open the main valve, and connect the diffusion pump or molecular pump to continue to increase the vacuum degree of the equipment.

[0067] (2) When the vacuum degree reaches 10 -2 When the pressure reaches 0.05 MPa, the vacuum equipment is turned off and argon gas is introduced into the furnace. When the pressure inside the furnace reaches 0.05 MPa, the gas supply is stopped. The temperature is increased at 20℃ / min through the control program. After reaching 1000℃, the furnace enters the heat preservation stage, which lasts for 15 minutes.

[0068] (3) After the melting stage is completed, the power is turned off, the motor is controlled to tilt the crucible, so that the metal La is poured into the liquid metal casting mold. After natural cooling for 20 minutes, the casting mold is removed after the vacuum is broken, and the mold is demolded by physical means.

[0069] (4) After the casting block 1 shows obvious deformation, the bottom of the casting block 1 in the mold cavity 2 is tapped by physical means to easily separate the casting block 1 from the mold cavity 2. After simply removing the residual metal in the hollow part of the mold cavity 2, the new casting block 1 is tightly attached to the mold cavity 2 to complete the reassembly of the casting mold.

[0070] The various embodiments in this utility model are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0071] The scope of protection of this utility model is not limited to the above-described embodiments. Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its scope and spirit. If these modifications and variations fall within the scope of the claims of this utility model and their equivalents, then the intent of this utility model also includes these modifications and variations.

Claims

1. A liquid metal casting mold, characterized in that, include: The mold cavity is a groove with its opening facing upwards, and a through hole is opened at the bottom of the groove, which defines a truncated cone-shaped internal space with its tip pointing downwards. The casting block is in the shape of a truncated cone with the tip pointing downwards, and is in close contact with the through hole; Wherein, at room temperature, the upper surface of the casting block is at the same height as the bottom of the mold cavity, the lower surface of the casting block is not lower than the lower surface of the mold cavity, and the ratio of the height difference between the two to the depth of the through hole in the mold cavity is less than or equal to 30%.

2. The liquid metal casting mold according to claim 1, characterized in that, The cross-section of the casting block is circular or regular polygonal, and the cross-section is parallel to the plane of the mold cavity.

3. The liquid metal casting mold according to claim 1, characterized in that, In a cross-section passing through the centerline of the casting block, the intersection of the side surface of the casting block and the cross-section is the first line segment, and the intersection of the upper surface of the casting block and the cross-section is the second line segment. The included angle between the first line segment and the second line segment is in the range of 30° to 80°.

4. The liquid metal casting mold according to claim 1, characterized in that, In a cross-section passing through the centerline of the casting block, the intersection of the side surface of the casting block and the cross-section is the first line segment, and the intersection of the upper surface of the casting block and the cross-section is the second line segment. The included angle between the first line segment and the second line segment is in the range of 40° to 70°.

5. The liquid metal casting mold according to claim 1, characterized in that, At room temperature, the lower surface of the casting block is flush with the lower surface of the mold cavity.

6. The liquid metal casting mold according to claim 1, characterized in that, The ratio of the area of ​​the upper surface of the casting block to the area of ​​the upper opening of the mold cavity is 20% to 50%.

7. The liquid metal casting mold according to claim 1, characterized in that, The bottom of the interior space of the mold cavity is flat.

8. The liquid metal casting mold according to claim 1, characterized in that, The bottom of the interior space of the mold cavity is rectangular or circular.

9. The liquid metal casting mold according to claim 1, characterized in that, The mold cavity also includes an ear that extends outward from the top of the groove.

10. The liquid metal casting mold according to claim 1, characterized in that, The line connecting the geometric center of the casting block and the geometric center of the opening of the mold cavity is perpendicular to the plane in which the mold cavity is located.

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