Flexible die-casting die for producing high-quality precision casting with non-uniform wall thickness

Abstract

The invention provides a flexible die-casting die for producing high-quality precision castings with non-uniform wall thicknesses, and relates to the technical field of die casting of aluminum alloy high-quality precision castings. The circumferential side wall of a conformal cooling core of the die-casting die and a movable die insert are provided with a first cavity, and the conformal cooling core and a fixed die insert can form a second cavity; the movable mold insert and the fixed mold insert can be matched to form a third cavity when the movable mold frame and the fixed mold frame abut against each other, and the first cavity, the second cavity and the third cavity are matched to form a die-casting cavity. The pipeline cross section area of the main runner structure in the pipeline direction and in the direction of the die-casting cavity is gradually reduced, and the end, with the smallest cross section area, of the main runner structure in the direction of the die-casting cavity communicates with the die-casting cavity. According to the injection mold, metal liquid or molten metal materials in the runner can have the advantage of being stable in filling in the injection process, a large amount of entrapped gas and oxidation slag inclusion are prevented from being generated in the metal liquid or the molten metal materials, and therefore the quality of castings can be effectively improved.

Description

Technical Field

[0001] This specification relates to the field of die casting technology for high-quality precision castings of aluminum alloys, and more specifically, to a flexible die casting mold for producing high-quality precision castings with uneven wall thickness. Background Technology

[0002] Die casting refers to metal mold pressure casting performed on a die casting machine. It is a special casting method with minimal or no cutting that has seen rapid development in modern metal processing technology. It involves filling a mold with molten metal or semi-liquid or semi-solid metal under high pressure and high speed, and then solidifying it under high pressure to form a casting. It boasts advantages such as high productivity, high dimensional accuracy, good overall performance, low cost, and near-net-shape forming, and has been widely used in transportation, electronic communications, instrumentation, computers, and electrical appliances. Traditional die casting technology is characterized by high pressure and high speed, and often fills the mold cavity in a jet or turbulent flow manner. This often results in defects such as air entrapment, oxide inclusions, and shrinkage porosity in ordinary die castings. Castings formed through this method not only have reduced mechanical properties and airtightness, but also cannot undergo significant machining, welding, or heat treatment, thus limiting the application range of die castings. Especially for high-quality parts with uneven wall thickness, if the process and mold design are not reasonable, the manufactured castings will have the following problems, such as shrinkage cavities, porosity, air entrapment and incomplete filling. For parts with high quality and precision requirements, once casting defects occur, they will be scrapped or the pressure-bearing effect will be affected. Summary of the Invention

[0003] The purpose of this specification is to provide a flexible die-casting mold for producing high-quality precision castings with uneven wall thickness, which can overcome the above-mentioned defects of traditional die-casting technology.

[0004] The embodiments described in this specification are implemented as follows:

[0005] A flexible die-casting mold for producing high-quality precision castings with uneven wall thickness includes a moving mold frame, a moving mold insert, a fixed mold frame, a fixed mold insert, and a main runner structure, wherein the sidewalls of the moving mold frame in the thickness direction and the sidewalls of the fixed mold frame in the thickness direction can abut against each other.

[0006] The moving mold insert is embedded in the side wall of the moving mold frame near the fixed mold frame, and the fixed mold insert is embedded in the side wall of the fixed mold frame near the moving mold frame;

[0007] A conformal cooling core is embedded at a preset position in the moving mold insert. The circumferential sidewall of the conformal cooling core has a first cavity with the moving mold insert. When the moving mold frame and the fixed mold frame abut, the conformal cooling core can form a second cavity with the fixed mold insert. When the moving mold frame and the fixed mold frame abut, the moving mold insert and the fixed mold insert can cooperate to form a third cavity. The first cavity, the second cavity, and the third cavity are interconnected and can cooperate to form a die-casting cavity. The die-casting cavity is used to fill material to form a casting.

[0008] The cross-sectional area of ​​the main channel structure gradually decreases along its pipe direction and toward the die-casting cavity, and the end of the main channel structure with the smallest cross-sectional area toward the die-casting cavity is connected to the die-casting cavity.

[0009] The embodiments described in this specification have at least the following advantages or beneficial effects:

[0010] Compared with existing technologies, this flexible die-casting mold for producing high-quality precision castings with uneven wall thickness has the advantage of stable filling of liquid metal or molten metal material in the flow channel during the injection process by setting a main flow channel structure with gradually decreasing cross-sectional area. This avoids the generation of a large amount of air entrapment and oxide inclusions in the liquid metal or molten metal material, thereby effectively improving the quality of the castings. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of this specification, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this specification and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a structural schematic diagram of the moving mold frame provided in this specification;

[0013] Figure 2 This is a structural schematic diagram of the fixed mold frame provided in this specification;

[0014] Figure 3 This is a schematic diagram of the simulation structure of the horizontal runner provided in this manual;

[0015] Figure 4 This is a schematic diagram showing the location of the ingate provided in this manual;

[0016] Figure 5 This is a schematic diagram of the cross-section of the ingate provided in this specification;

[0017] Figure 6 This is a structural schematic diagram of core one provided in this specification;

[0018] Figure 7 This is a structural schematic diagram of core two provided in this specification;

[0019] Figure 8 This is a schematic diagram of the installation of the conformal cooling core provided in this manual.

[0020] Icons: 1. Moving mold frame; 2. Fixed mold frame; 3. Moving mold insert; 4. Fixed mold insert; 5. Conformal cooling core; 6. Ingate; 61. Ingate; 7. Stream runner; 71. First channel; 72. Second channel; 73. Third channel; 8. Straight runner; 9. Runner cone; 10. First cavity; 11. Sprue; 12. Sprue sleeve; 13. Overflow groove; 14. Core one; 15. Core two; 16. Conformal cooling channel; 161. First cooling channel; 162. Second cooling channel; 163. Third cooling channel; 17. Moving mold plate; 18. Screw; 19. Casting. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments in this specification clearer, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Generally, the components of the embodiments of this specification described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments provided in the accompanying drawings is not intended to limit the scope of the claimed specification, but merely represents selected embodiments of the specification. All other embodiments obtained by those skilled in the art based on the embodiments in this specification without inventive effort are within the scope of protection of this specification.

[0023] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] In the description of the embodiments in this specification, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product is in use. These are used only for the convenience of describing this specification and for simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this specification. Furthermore, the terms "first," "second," and "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0025] Furthermore, the use of terms such as "horizontal," "vertical," and "suspended" does not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0026] In the description of the embodiments in this specification, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this specification according to the specific circumstances.

[0027] Please refer to Figures 1 to 8 The flexible die-casting mold provided in one embodiment of this specification for producing high-quality precision castings with uneven wall thickness mainly includes a moving mold frame 1, a moving mold insert 3, a fixed mold frame 2, a fixed mold insert 4, and a main runner structure. The sidewalls of the moving mold frame 1 in the thickness direction and the sidewalls of the fixed mold frame 2 in the thickness direction can abut against each other.

[0028] The moving mold insert 3 is embedded in the side wall of the moving mold frame 1 near the fixed mold frame 2, and the fixed mold insert 4 is embedded in the side wall of the fixed mold frame 2 near the moving mold frame 1;

[0029] The moving mold insert 3 is fitted with a conformal cooling core 5 at a preset position. The circumferential sidewall of the conformal cooling core 5 and the moving mold insert 3 have a first cavity 10. When the moving mold frame 1 and the fixed mold frame 2 abut, the conformal cooling core 5 can form a second cavity with the fixed mold insert 4. When the moving mold frame 1 and the fixed mold frame 2 abut, the moving mold insert 3 and the fixed mold insert 4 can cooperate to form a third cavity. The first cavity 10, the second cavity and the third cavity are interconnected and can cooperate to form a die-casting cavity. The die-casting cavity is used to fill material to form a casting 19.

[0030] The cross-sectional area of ​​the main channel structure gradually decreases along its pipe direction and toward the die-casting cavity, and the end of the main channel structure with the smallest cross-sectional area toward the die-casting cavity is connected to the die-casting cavity.

[0031] Specifically, the aforementioned flexible die-casting mold, by setting a main channel structure with a gradually decreasing cross-sectional area, enables the liquid metal or molten metal material in the channel to have the advantage of stable filling during the injection process, avoiding the generation of a large amount of entrapment and oxide inclusions in the liquid metal or molten metal material, thereby effectively improving the quality of the casting 19.

[0032] In this embodiment, Figure 1 The upper and lower directions are shown as the upward and downward directions, respectively. The main channel structure is located on one side of the short side of the moving mold frame 1, and is preferably located below the moving mold frame 1.

[0033] In this embodiment, the moving mold insert 3 is a hexahedron with a rounded rectangular cross-section. A groove adapted to the moving mold insert 3 is provided at a preset position on the moving mold frame 1, and the moving mold insert 3 is embedded in the groove. The fixed mold insert 4 is set in the same way as the moving mold insert 3, that is, the fixed mold frame 2 has a groove on the side facing the moving mold frame 1, and the fixed mold insert 4 is embedded in the groove.

[0034] In this embodiment, the moving mold insert 3 has a first moving mold part and a second moving mold part arranged along its thickness direction. The side wall of the first moving mold part facing the second moving mold part is flush with the side wall of the moving mold frame 1 facing the fixed mold frame 2. One side of the second moving mold part is stacked with the edge of the first moving mold part, and the other side (i.e. the upper end) has the same shape as the corresponding position of the casting 19. The thickness of the second moving mold part is the same as the height of the casting 19, such as the height of the box when the casting 19 is a box.

[0035] In this embodiment, the fixed mold insert 4 has a first fixed mold part and a second fixed mold part stacked along its thickness direction. The first fixed mold part can be embedded in the groove of the fixed mold frame 2. The side wall of the first fixed mold part facing the second fixed mold part is flush with the side wall of the fixed mold frame 2 facing the moving mold frame 1. The upper part of the second fixed mold part is aligned with the circumferential edge of the first fixed mold part, and the lower part of the second fixed mold part is consistent with the shape of the corresponding position of the casting 19. The shapes of the second fixed mold part and the second moving mold part are symmetrically arranged near the position of the casting 19 so that the second moving mold part and the second fixed mold part can be adapted to form a die casting cavity.

[0036] In this embodiment, the main runner structure includes an ingate 6 and a runner 7. The runner 7 has a first channel 71, a second channel 72 and a third channel 73. One end of the first channel 71 and one end of the second channel 72 are connected to the third channel 73. The other end of the first channel 71 and the other end of the second channel 72 are respectively connected to the two ingates 6. The two ingates 6 are respectively disposed on both sides of the first cavity 10 and are respectively connected to the first cavity 10.

[0037] In this embodiment, the first cavity 10 is provided with an ingate 61 near the cavity wall of the ingate 6. The ingate 61 is connected to one end of the ingate 6. The side walls of the first channel 71 and the second channel 72 are provided with connection ports, which are connected to the other end of the ingate 6.

[0038] Specifically, by setting two ingates 6 and two branch channels in the horizontal runner 7, the material about to flow into the die-casting cavity can be divided into two branches to enter. This allows the filling material to fill the die-casting cavity smoothly during the injection process, satisfying the sequential filling state. It avoids defects such as air entrapment and oxide inclusions caused by multiple diversions and convergences of the filling material, thereby improving the quality of the casting 19.

[0039] Furthermore, by placing the ingate 6 on both sides of the first cavity 10, and with the ingate 6 located on the lower side wall of the first cavity 10, it is possible to prevent the high-speed filling material from directly impacting the mold core and cavity wall, thus avoiding splashing and sticking, generating a large amount of air entrapment, and affecting the quality of the casting 19. Moreover, placing the ingate 6 on the side wall of the first channel 71 and the second channel 72 can further improve the stability of the filling material during the injection process.

[0040] In this embodiment, the filling material can be liquid metal or molten metal.

[0041] In this embodiment, the first channel 71, the second channel 72, and the third channel 73 cooperate to form a Y-shape. The third channel 73 has two ports at one end near the conformal cooling core 5, and the two ports are respectively connected to the first channel 71 and the second channel 72. The end of the third channel 73 away from the conformal cooling core 5 is arc-shaped, and a cylindrical overflow groove 13 is provided at the end of the third channel 73 away from the conformal cooling core 5.

[0042] In this embodiment, the Y-shaped arrangement and the arc-shaped arrangement of the third channel 73 further enhance the filling material's ability to fill smoothly.

[0043] In this embodiment, the main runner structure further includes a runner cone 9 and a sprue 8. The third channel 73 communicates with the runner cone 9, and the sprue 8 is disposed on the fixed mold frame 2. Specifically, the main runner structure also includes a sprue 11 opened in the fixed mold frame 2 and a sprue sleeve 12 installed inside the sprue 11. The runner cone 9 is disposed below the sprue sleeve 12, and the position of the runner cone 9 corresponds to the position of the sprue 11.

[0044] In this embodiment, the ratio of the maximum cross-sectional area of ​​the horizontal gating 7 to the cross-sectional area of ​​the inner gating 6 is 1.5-2.0:1. It can be seen that by gradually reducing the cross-sectional area of ​​the channels proportionally, the pressure transmission of the filling material during the injection process can be controlled stably, further achieving a smooth filling effect, satisfying the sequential filling state, avoiding defects such as air entrapment and oxidation inclusions, and effectively improving product quality.

[0045] In this embodiment, the aforementioned ingate 6 is located in the thickest part of the casting 19 (it can be the thickest part or a part with a thickness greater than the average thickness of the casting 19), and a near-equal wall thickness near-casting method is adopted, which can facilitate the feeding of the solidification process by pressurization, thereby obtaining a high-density, low-gas-content, high-quality precision casting 19.

[0046] In this embodiment, the ingate 6 has a trapezoidal cross-sectional shape, with the smaller end of the trapezoidal cross-section facing the fixed mold frame 2. The cross-sectional area of ​​the ingate 6 is 350 mm². 2 ~380mm 2 The thickness of the inner sprue 6 along the thickness direction of the moving mold frame 1 is 6mm to 7mm. This specific arrangement effectively avoids high-speed filling material directly impacting the mold core and cavity walls, thus preventing splashing and sticking, and generating a large amount of air entrapment, which could affect the quality of the casting 19.

[0047] In this embodiment, the conformal cooling core 5 has multiple conformal cooling channels 16. The length and position of the multiple conformal cooling channels 16 are determined according to the thickness of each part of the casting 19, and the distance between the channel wall of the conformal cooling channel 16 and the die-casting cavity is determined according to the wall thickness of the casting 19. Specifically, the diameter of the conformal cooling channel 16 is preferably 8mm-12mm, the distance between the conformal cooling channel 16 and the maximum wall thickness of the casting 19 is preferably 8mm-10mm, and the corners of the conformal cooling channel 16 are all rounded for smooth transition. By setting the conformal cooling channels 16, the thermal stability of the mold during the injection process can be controlled, and the casting 19 can be solidified sequentially from the far end to the near end of the ingate 61, thereby eliminating shrinkage cavities and porosity defects caused by uneven wall thickness of the casting 19 and improving product quality.

[0048] In this embodiment, a plurality of overflow grooves 13 are also included. The plurality of overflow grooves 13 are respectively disposed on the moving mold frame 1 and the fixed mold frame 2, and the overflow grooves 13 are connected to the die casting cavity.

[0049] In this embodiment, the total volume of the plurality of overflow channels 13 is 30.0 cm³. 3 ~42.0cm 3 The thickness of the overflow groove 13 along the thickness direction of the moving mold frame 1 or the fixed mold frame 2 is half the average wall thickness of the casting 19 located at the overflow groove 13.

[0050] Specifically, the number of overflow grooves 13 is preferably 10. Seven overflow grooves 13 are symmetrically distributed at the position of the second fixed mold part that matches the shape of the casting 19, and three overflow grooves 13 are symmetrically distributed at the position of the inner gating 6. It can be seen that the above arrangement can effectively remove the cold sludge molten metal mixed with gas and paint residue (i.e., a kind of filling material), improve the flow state of the molten metal, and prevent local eddies. Moreover, by setting a wave-shaped venting groove at the rear end of the overflow groove 13, the overflow and venting effect can be enhanced, and defects such as shrinkage porosity and shrinkage cavities at local hot spots can be improved, thereby increasing the density and strength of the casting 19. At the same time, the gas content of the casting 19 can be greatly reduced, so that the casting 19 can be subjected to high-temperature heat treatment above 500°C (such as T6 treatment), further improving the strength of the casting 19.

[0051] In this embodiment, the conformal cooling core 5 can be produced by 3D printing and integral molding. Using 3D printing technology to quickly manufacture interchangeable cores can shorten the mold manufacturing cycle. Furthermore, 3D printing technology can form complex and curved cooling channels inside the core, which helps to accurately solidify and form complex structures, thereby improving the forming quality and precision of the casting 19.

[0052] Moreover, by setting interchangeable cores (i.e., core one 14 and core two 15), a "one mold for multiple parts" production mode can be achieved for castings 19 with uneven wall thickness. This means that a single mold can be used to form two or more different castings 19 with high quality and precision, thereby reducing mold costs.

[0053] In this embodiment, both the first core 14 and the second core 15 are provided with three conformal cooling channels 16, which are distinguished as the first cooling channel 161, the second cooling channel 162 and the third cooling channel 163. The first cooling channel 161 of the first core 14 and the second core 15 are consistent, the second cooling channel 162 of the first core 14 and the second core 15 are consistent, and the bending shape and length of the third cooling channel 163 of the first core 14 and the second core 15 are determined according to the thickness of the core itself, so as to achieve better heat dissipation effect in the middle part of the first core 14 and the second core 15.

[0054] In this embodiment, to facilitate the interchangeability of core 14 and core 2 15, the conformal cooling core 5 is fixed using a through-hole sleeve structure. That is, a moving mold sleeve 17 is used to support the moving mold insert 3 below, and then screws 18 are used for fastening, thereby realizing flexible die-casting production of different castings 19. Please refer to [the relevant documentation] for details. Figure 8 .

[0055] The above are merely preferred embodiments of this specification and are not intended to limit this specification. Various modifications and variations can be made to this specification by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this specification should be included within the scope of protection of this specification.

Claims

1. A flexible die-casting mold for producing high-quality precision castings with uneven wall thickness, characterized in that, It includes a moving mold frame, a moving mold insert, a fixed mold frame, a fixed mold insert, and a main runner structure, wherein the sidewalls of the moving mold frame in the thickness direction and the sidewalls of the fixed mold frame in the thickness direction can abut against each other; The moving mold insert is embedded in the side wall of the moving mold frame near the fixed mold frame, and the fixed mold insert is embedded in the side wall of the fixed mold frame near the moving mold frame; A conformal cooling core is embedded at a preset position in the moving mold insert. The circumferential sidewall of the conformal cooling core has a first cavity with the moving mold insert. When the moving mold frame and the fixed mold frame abut, the conformal cooling core can form a second cavity with the fixed mold insert. When the moving mold frame and the fixed mold frame abut, the moving mold insert and the fixed mold insert can cooperate to form a third cavity. The first cavity, the second cavity, and the third cavity are interconnected and can cooperate to form a die-casting cavity. The die-casting cavity is used to fill material to form a casting. The cross-sectional area of ​​the main channel structure gradually decreases along its pipe direction and toward the die-casting cavity, and the end of the main channel structure with the smallest cross-sectional area toward the die-casting cavity is connected to the die-casting cavity.

2. The flexible die-casting mold for producing high-quality precision castings with uneven wall thickness according to claim 1, characterized in that, The main runner structure includes an ingate and a runner. The runner has a first channel, a second channel, and a third channel. One end of the first channel and one end of the second channel are connected to the third channel. The other ends of the first channel and the second channel are respectively connected to the two ingates. The two ingates are respectively located on both sides of the first cavity and are respectively connected to the first cavity.

3. The flexible die-casting mold for producing high-quality precision castings with uneven wall thickness according to claim 2, characterized in that, An ingate is provided on the cavity wall of the first cavity near the ingate, and the ingate is connected to one end of the ingate. Both the first channel and the second channel have connection ports on their side walls, and the connection ports are connected to the other end of the ingate.

4. The flexible die-casting mold for producing high-quality precision castings with uneven wall thickness according to claim 2, characterized in that, The first channel, the second channel, and the third channel cooperate to form a Y-shape. The third channel has two ports at the end closest to the conformal cooling core, which are respectively connected to the first channel and the second channel. The end of the third channel away from the conformal cooling core is arc-shaped, and a cylindrical overflow groove is provided at the end of the third channel away from the conformal cooling core.

5. The flexible die-casting mold for producing high-quality precision castings with uneven wall thickness according to claim 2, characterized in that, The main runner structure also includes a runner cone and a sprue, the third channel is connected to the runner cone, and the sprue is disposed on the fixed mold frame.

6. The flexible die-casting mold for producing high-quality precision castings with uneven wall thickness according to claim 2, characterized in that, The ratio of the maximum cross-sectional area of ​​the horizontal runner to the cross-sectional area of ​​the ingate is 1.5 to 2.0:

1.

7. The flexible die-casting mold for producing high-quality precision castings with uneven wall thickness according to claim 6, characterized in that, The ingate has a trapezoidal cross-sectional shape, with the smaller end of the trapezoidal cross-section facing the fixed mold frame. The cross-sectional area of ​​the ingate is 350 mm². 2 ~380mm 2 The thickness of the inner sprue along the thickness direction of the moving mold frame is 6mm to 7mm.

8. The flexible die-casting mold for producing high-quality precision castings with uneven wall thickness according to claim 1, characterized in that, The conformal cooling core has multiple conformal cooling channels. The length and location of the multiple conformal cooling channels are determined according to the thickness of each part of the casting. The distance between the pipe wall of the conformal cooling channel and the die-casting cavity is determined according to the wall thickness of the casting.

9. The flexible die-casting mold for producing high-quality precision castings with uneven wall thickness according to claim 1, characterized in that, It also includes multiple overflow channels, which are respectively disposed on the moving mold frame and the fixed mold frame, and the overflow channels are connected to the die-casting cavity.

10. The flexible die-casting mold for producing high-quality precision castings with uneven wall thickness according to claim 9, characterized in that, The total volume of the plurality of overflow channels is 30.0 cm³. 3 ~42.0cm 3 .

Images