Die casting mold for automobile parts production

Abstract

This application relates to the field of molds, and provides a die-casting mold for the production of automotive parts, including a moving mold, a fixed mold, a sprue bushing, and a venting assembly; a cavity, a runner, and an overflow groove are formed between the moving mold and the fixed mold; the cavity is located around the runner; the runner and the overflow groove are both connected to the cavity; the sprue bushing is located in the middle of the fixed mold; the sprue bushing includes an insulator, an outer cooling sleeve, and a retaining ring, the outer cooling sleeve is fitted outside the insulator, and a heat-conducting medium is filled between the insulator and the outer cooling sleeve; a retaining ring is provided on the inner side of the outer cooling sleeve; the retaining ring is fitted onto the insulator; an annular retaining groove is provided on the inner side of the outer cooling sleeve, the retaining ring passes into the annular retaining groove and slides within the annular retaining groove; a pre-reserved expansion gap exists between the inner wall of the annular retaining groove and the retaining ring; the outer cooling sleeve has cooling channels inside; the venting assembly is connected to the overflow groove. This application solves the problems of casting defects and sprue bushing damage.

Description

Technical Field

[0001] This application relates to the field of molds, and more particularly to a die-casting mold for the production of automotive parts. Background Technology

[0002] With the rapid development of the automotive industry, automotive parts are evolving towards lighter weight, greater complexity, and higher precision. Die casting, as a near-net-shape forming technology capable of efficiently producing complex thin-walled parts, has been widely used in the production of automotive parts made of aluminum alloys and magnesium alloys (such as engine blocks, transmission housings, and steering knuckles).

[0003] In the die-casting production process, the performance of the die-casting mold directly determines the product quality and production efficiency. Molten metal enters the runner through the sprue bushing. The runner is connected to one side of the mold cavity, allowing the molten metal to enter from one side and flow towards the other to gradually fill the cavity. As the molten metal gradually fills the cavity, it forces air out of the cavity and eventually expels it.

[0004] However, the problem with the above method is that the molten metal gradually cools during flow, resulting in a lower temperature at the front and a higher temperature at the rear. The cooled molten metal at the front becomes viscous and rubs against the mold surface, leaving unsightly flow marks. Furthermore, when two streams of low-temperature molten metal meet, the surface of the molten metal is already oxide-covered or in a semi-solid state due to its low temperature, preventing perfect fusion and creating a "false seam," or cold shut. The cold shut is extremely fragile, leading to defects in the casting. Even more seriously, if the molten metal solidifies before the cavity is filled, the solidified metal will obstruct the flow of subsequent molten metal, resulting in appearance defects in the casting.

[0005] To avoid the aforementioned problems, some manufacturers choose to increase the temperature of the molten metal. However, this places higher demands on the cooling of the sprue bushing. Since the sprue bushing has a limited lifespan, designing it as a one-piece structure with complex cooling channels inside would significantly increase costs and easily lead to rapid cooling and cracking. Therefore, current sprue bushings typically employ a split structure, consisting of an inner sprue and an outer cooling jacket fitted over it. Cooling channels are located inside the outer cooling jacket or between the outer cooling jacket and the inner sprue, thereby cooling the inner sprue.

[0006] However, to achieve good heat transfer, an interference fit is usually used between the ingate and the outer cooling jacket. Since the ductility of metals is affected by temperature, and the temperature of the ingate is higher than that of the outer cooling jacket, the ingate's thermal expansion can push against the outer cooling jacket, easily causing damage. Furthermore, to further simplify the manufacturing of the cooling channels, some sprue bushings use grooves on both the outer wall of the ingate and the inner wall of the outer cooling jacket to form cooling channels. During thermal expansion and contraction of the ingate and the outer cooling jacket, leakage of the cooling medium within the cooling channels is likely. Summary of the Invention

[0007] To address the issues of defects in castings and damage to the sprue bushing, this application provides a die-casting mold for the production of automotive parts.

[0008] This application provides a die-casting mold for automotive parts production, which adopts the following technical solution: A die-casting mold for the production of automotive parts includes: a moving mold, a fixed mold, a sprue bushing, and a venting assembly; The moving mold and the fixed mold are configured to close together to form a cavity, a runner, and an overflow channel between them; the cavity surrounds the periphery of the runner; the runner and the overflow channel are both connected to the cavity, and there are multiple connections between the runner and the cavity; The sprue sleeve is located in the middle of the fixed mold and communicates with the runner. The sprue sleeve includes an ingate, an outer cooling sleeve, and a limiting ring. The outer cooling sleeve is fitted around the outside of the ingate with a gap between them. A heat-conducting medium is filled between the ingate and the outer cooling sleeve. The limiting ring is located on the inner side of at least one end of the outer cooling sleeve. The limiting ring is fitted onto the ingate and has an interference fit with it. The inner side of the outer cooling sleeve has an annular limiting groove corresponding to the limiting ring. The outer side of the limiting ring passes into the corresponding annular limiting groove and slides with it. There is a reserved expansion gap between the inner wall of the annular limiting groove and the corresponding limiting ring. The reserved expansion gap is configured to prevent the heat-conducting medium from passing through. The outer cooling sleeve has cooling channels inside. The exhaust assembly is connected to the overflow channel.

[0009] By adopting the above technical solution, on the one hand, the cavity is surrounded by the horizontal runner, and there are multiple connections between the horizontal runner and the cavity. The sprue sleeve is centrally located, allowing the molten metal to diffuse outward from the center, effectively shortening the flow distance of the molten metal and avoiding casting defects such as flow marks and cold shuts caused by excessive local cooling of the molten metal. On the other hand, the space between the ingate and the outer cooling sleeve is filled with a heat-conducting medium, achieving good heat transfer. There is a gap between the outer cooling sleeve and the ingate, and the sliding fit of the limiting ring in the annular limiting groove and the design of the reserved expansion gap provide sufficient buffer space for the thermal expansion of the ingate, effectively avoiding the problem of the outer cooling sleeve being damaged or cracked due to the outward compression caused by the thermal expansion and contraction of the ingate. The limiting ring can realize the mutual limiting of the ingate and the outer cooling sleeve, and the limiting ring can also prevent the leakage of the heat-conducting medium, significantly extending the service life of the sprue sleeve.

[0010] Optionally, the outer cooling jacket has a receiving groove in the middle of its inner side for accommodating the heat-conducting medium; the distance between the inner end of the outer cooling jacket and the inner gating pipe is smaller than the distance between the bottom of the receiving groove and the inner gating pipe. The distance between the inner end of the outer cooling jacket and the inner gating pipe is configured to prevent the heat-conducting medium from passing through.

[0011] By adopting the above technical solution and utilizing the structural design where the end spacing is smaller than the bottom spacing, not only can sufficient heat transfer medium be effectively stored inside the receiving tank to ensure excellent heat transfer effect, but the narrow spacing at the inner ends can also form a physical barrier to further prevent the heat transfer medium from leaking outward from the ends, thereby improving the sealing performance and operational reliability of the gating sleeve assembly.

[0012] Optionally, the limiting ring has a limiting protrusion on the side facing the receiving groove, and the limiting protrusion is used to limit the engagement with the inner wall of the corresponding annular limiting groove.

[0013] By adopting the above technical solution, the limiting protrusion can limit the sliding position of the limiting ring, prevent the limiting ring from falling out of the annular limiting groove, and ensure the stability of the sliding fit between the limiting ring and the annular limiting groove. At the same time, the setting of the limiting protrusion can make the extension path of the gap between the limiting ring and the annular limiting groove more tortuous, thereby further preventing the leakage of heat transfer medium.

[0014] Optionally, the outer cooling jacket includes an annular body and two annular end caps, with the two annular end caps respectively disposed at opposite ends of the annular body; The receiving groove is located on the inner side of the annular body; The cooling channel includes multiple first channels and multiple second channels; the multiple first channels are spaced apart circumferentially on the annular body, and both ends of the first channels penetrate the annular body; multiple cooling grooves are provided at opposite ends of the annular body, and each cooling groove has two adjacent first channels communicating with it; the multiple cooling grooves are arranged sequentially circumferentially along the annular body, and two adjacent cooling grooves are located on opposite sides of the annular body; the annular end cap and the cooling grooves together constitute the second channel; The outer cooling jacket is provided with an inlet and an outlet that communicate with the first flow channel.

[0015] By adopting the above technical solution, the outer cooling jacket is designed as a split-type composite structure consisting of a ring-shaped main body and a ring-shaped end cap. This allows for the easy fabrication of the corresponding first flow channel and cooling groove on the end of the ring-shaped main body, which, when combined with the ring-shaped end cap, forms a complex and continuous internal cooling flow channel. This structure significantly reduces the processing difficulty and manufacturing cost of traditional integrated complex flow channels, while ensuring efficient cooling of the ingate tube.

[0016] Optionally, at least one of the annular end caps includes an end cap body and a limiting cover, the limiting cover being detachably disposed on the side of the corresponding end cap body away from the annular body; the limiting cover and the corresponding end cap body together form the annular limiting groove.

[0017] By adopting the above technical solution, the detachable design of the limiting cover allows the originally closed annular limiting groove to be opened, thus facilitating the assembly and disassembly of components such as the ingate, limiting ring, and outer cooling sleeve. This makes replacing worn limiting rings quicker and more convenient, effectively reducing the difficulty and cost of mold maintenance.

[0018] Optionally, the heat-conducting medium is a thermoplastic heat-conducting medium.

[0019] By adopting the above technical solution, the heat-conducting medium is solid at room temperature, which can eliminate leakage problems under normal temperature conditions during shutdown; while under the high temperature working condition of die casting, it melts into liquid when heated, which can fully fit with the inner gating pipe and the outer cooling jacket, achieving excellent heat conduction, and adaptively buffering the flow when the inner gating pipe expands and is squeezed, giving full play to the dual role of heat transfer and anti-expansion cracking.

[0020] Optionally, the moving mold is provided with a groove communicating with the cavity; The die-casting mold further includes an opening assembly, which includes a driving member, a wedge, and a rod. The wedge is slidably disposed in the groove, and one end of the rod is connected to the wedge. The driving member is connected to the wedge and is used to drive the wedge and the rod to move so that the end of the rod away from the wedge passes into the cavity.

[0021] By adopting the above technical solution, the mold integrates an automated hole-opening component, enabling the drive component to drive the rod to extend into the cavity to complete the forming of pre-reserved holes or partial core pulling during the corresponding stages of molten metal filling and solidification. This allows automotive parts with complex internal structures such as holes to be formed directly in the die-casting process in one step, eliminating the need for subsequent tedious machining and drilling processes, and greatly improving production efficiency.

[0022] Optionally, the venting assembly includes a venting block disposed within the overflow groove; one of the fixed mold and the moving mold is connected to the venting block, and there is a venting gap between the other of the fixed mold and the moving mold and the venting block.

[0023] By adopting the above technical solution, the venting gap between the venting block and the mold allows the air squeezed out by the rapidly filled molten metal in the cavity and runner to be smoothly discharged through the overflow groove, effectively reducing the air entrapment phenomenon during the filling process and reducing the probability of porosity and shrinkage defects inside the casting.

[0024] Optionally, the exhaust assembly further includes a vacuum generator and an exhaust pipe, wherein the vacuum generator is connected to the end of the overflow groove away from the cavity via the exhaust pipe.

[0025] By adopting the above technical solution, the vacuum generator can actively draw air from the mold cavity and overflow groove during the die-casting process, creating a negative pressure or vacuum state inside the mold cavity. This greatly accelerates the exhaust process and thoroughly removes any residual obstructing gas from the mold cavity. This design can significantly avoid porosity defects and greatly improve the internal density and mechanical properties of the produced automotive parts.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. By surrounding the cavity with the horizontal runner and feeding material from the center outwards at multiple points, the filling path is effectively shortened, avoiding flow marks and cold shuts. At the same time, the gap between the inner gating pipe and the outer cooling jacket is filled with a heat-conducting medium, and with the sliding and expansion gap design of the limiting ring, efficient cooling is ensured, and the thermal expansion of the inner gating pipe is perfectly resolved to prevent the extrusion damage to the outer jacket, greatly extending the service life of the gating sleeve. 2. By adopting a split-type external cooling jacket design that combines a ring-shaped main body and a ring-shaped end cap, the processing difficulty and manufacturing cost of the complex internal cooling channels are greatly reduced, and the disassembly and maintenance of the internal gating pipe assembly is convenient. 3. By introducing an exhaust assembly that includes a vacuum generator and an exhaust gap, efficient and active extraction of gas from the mold cavity is achieved, effectively eliminating air entrapment and porosity defects during the die casting process, and improving the structural density and overall yield of automotive parts. Attached Figure Description

[0027] Figure 1 This is a three-dimensional schematic diagram of the die-casting mold used for the production of automotive parts provided in this application; Figure 2 This is one of the partial structural schematic diagrams of the die-casting mold for the production of automotive parts provided in this application; Figure 3 This is the second partial structural schematic diagram of the die-casting mold for automotive parts production provided in this application; Figure 4 This is a three-dimensional schematic diagram of the sprue sleeve in the second embodiment provided in this application; Figure 5 This is a cross-sectional view of the sprue bushing in the second embodiment provided in this application; Figure 6 This is one of the partial exploded views of the sprue bushing in the second embodiment provided in this application; Figure 7 This is the second partially exploded view of the sprue bushing in the second embodiment provided in this application; Figure 8 This is a schematic diagram of the end face of the annular body in the second embodiment provided in this application.

[0028] Explanation of reference numerals in the attached figures: 1. Moving mold; 11. Cavity; 12. Streamer; 13. Overflow groove; 2. Mold setting; 3. Sprue sleeve; 31. Ingate tube; 32. Outer cooling sleeve; 321. Annular body; 3211. Receiving groove; 3212. First runner; 3213. Cooling groove; 322. Annular end cap; 3221. Annular limiting groove; 3222. Inlet; 3223. Outlet; 3224. End cap body; 3225. Limiting cap; 33. Limiting ring; 331. Limiting protrusion; 4. Hole opening assembly; 41. Drive component; 42. Wedge block; 43. Rod body; 5. Exhaust assembly; 51. Exhaust block; 52. Vacuum generator; 53. Exhaust pipe; 6. Pop out the component; 200. Castings. Detailed Implementation

[0029] The following is in conjunction with the appendix Figures 1 to 8 This application will be described in further detail.

[0030] Example 1

[0031] like Figures 1 to 3 As shown, this embodiment discloses a die-casting mold for the production of automotive parts, including a moving mold 1, a fixed mold 2, a sprue bushing 3, an opening assembly 4, a venting assembly 5, and an ejection assembly 6.

[0032] The moving mold 1 and the fixed mold 2 can move relative to each other through an external mold closing mechanism to open and close. When closed, they together form a cavity 11 for molding automotive parts (casting 200), a runner 12 for guiding high-temperature molten metal, and an overflow channel 13 for containing cold material and gas. In terms of specific layout, the cavity 11 is annular or has a through hole in the middle, so that the cavity 11 can surround the outer area of ​​the runner 12. The runner 12 and the overflow channel 13 are interconnected with the cavity 11, and there are multiple connections between the runner 12 and the cavity 11, for example, through multiple ingates in a radial pattern. The sprue sleeve 3 is installed in the middle area of ​​the fixed mold 2 and remains connected to the runner 12 so that the molten metal can be smoothly injected into the runner 12 and flow from the middle to the periphery to be injected into the cavity 11. This structure, which involves central feeding and multi-point radiating filling, effectively shortens the flow distance of the molten metal, avoids flow marks on the mold surface caused by excessive cooling of the molten metal in certain areas, and also avoids casting defects such as cold shuts at the junctions of the molten metal.

[0033] The sprue sleeve 3 can adopt a conventional one-piece or split structure. In this embodiment, the sprue sleeve 3 adopts a conventional one-piece cylindrical steel structure, with a pipe for cooling water to flow through directly drilled holes in its inner wall, thereby cooling the sprue sleeve 3 through cooling water.

[0034] The overflow groove 13 is used to contain excess molten metal and air squeezed out from the cavity 11. The venting assembly 5 is connected to the overflow groove 13 to promptly discharge residual air from inside the cavity 11. The venting assembly 5 includes a venting block 51, which is installed inside the overflow groove 13. One of the fixed mold 2 and the moving mold 1 is connected to the venting block 51, and there is a venting gap between the other of the fixed mold 2 and the moving mold 1 and the venting block 51.

[0035] In this embodiment, the venting block 51 is fixed to the moving mold 1 with fastening screws, and a venting gap is reserved between the venting block 51 and the fixed mold 2. The width of the venting gap is precisely designed to allow gas to pass through smoothly, but to physically prevent viscous molten metal from overflowing. The venting gap allows the air squeezed out by the rapidly filling molten metal in the cavity 11 and the runner 12 to be smoothly discharged through the overflow groove 13, effectively reducing air entrapment during the filling process and lowering the probability of porosity and shrinkage defects inside the casting 200.

[0036] Furthermore, the exhaust assembly 5 also includes a vacuum generator 52 and an exhaust pipe 53. One end of the exhaust pipe 53 is connected to the end of the overflow groove 13 away from the cavity 11, and the other end is connected to the external vacuum generator 52 via a pipe connector. The vacuum generator 52 can actively draw air from the overflow groove 13 during the die casting process, accelerating the exhaust process and thoroughly removing residual obstructing gases in the cavity 11, significantly improving the internal density and mechanical properties of the produced automotive parts.

[0037] To directly form internal cavity structures during the die casting process 200, the moving mold 1 is provided with a groove communicating with the cavity 11. The die casting mold is also additionally equipped with an automated hole-opening assembly 4. The hole-opening assembly 4 includes a drive component 41, a wedge 42, and a rod 43. The drive component 41 can be a hydraulic cylinder or a pneumatic cylinder, and its output end is connected to the wedge 42. The wedge 42 is slidably fitted inside the groove. One end of the rod 43 is connected to the wedge 42. During the filling and solidification stages of the die-casting molten metal, the drive component 41 drives the wedge 42 and the rod 43 to move linearly along the groove, causing the end of the rod 43 facing away from the wedge 42 to penetrate and extend into the cavity 11. This allows for the direct one-time forming of parts with complex internal structures such as holes during the die casting process, eliminating the need for subsequent tedious machining and drilling steps, and significantly improving production efficiency.

[0038] After die casting, cooling, and mold opening, the mold also includes an ejector assembly 6 mounted on the moving mold 1 to remove the finished automotive parts from the mold. The ejector assembly 6 specifically includes an ejector plate, an ejector hydraulic cylinder, and multiple ejector rods. One end of each ejector rod is fixed to the ejector plate, and the other end passes through a pre-drilled hole inside the moving mold 1 and extends to the inner wall of the cavity 11. The output shaft of the ejector hydraulic cylinder is connected to the ejector plate. When die casting is complete and the moving mold 1 separates from the fixed mold 2, the ejector hydraulic cylinder pushes the ejector plate, causing the multiple ejector rods to extend forward synchronously, thereby smoothly ejecting the cooled and solidified casting 200 from the cavity 11 of the moving mold 1. This structural design enables automatic and rapid demolding of the casting 200, effectively improving the overall efficiency of die casting production and avoiding deformation or damage to the casting 200 that may be caused by manual removal.

[0039] Example 2

[0040] The difference between this embodiment and Embodiment 1 is that the gate sleeve 3 has been improved.

[0041] like Figures 4 to 6 As shown, the sprue sleeve 3 in this embodiment includes an ingate 31, an outer cooling sleeve 32, and a limiting ring 33. The ingate 31 is a high-temperature resistant cylindrical shape used to directly guide high-temperature molten metal. The outer cooling sleeve 32 is coaxially sleeved on the outside of the ingate 31, and an annular gap is reserved between the outer circumferential wall of the ingate 31 and the inner circumferential wall of the outer cooling sleeve 32. A heat-conducting medium is filled in the gap between the ingate 31 and the outer cooling sleeve 32 to achieve excellent heat transfer between the two.

[0042] To accommodate sufficient heat transfer medium, a recessed receiving groove 3211 is formed in the middle inner region of the outer cooling jacket 32. The radial distance between the inner end of the outer cooling jacket 32 ​​and the inner gating pipe 31 is smaller than the radial distance between the bottom of the receiving groove 3211 and the inner gating pipe 31. Simultaneously, the distance between the inner end of the outer cooling jacket 32 ​​and the inner gating pipe 31 is configured as a blocking gap, preventing the heat transfer medium from passing through. This structural design, where the end distance is smaller than the bottom distance, not only effectively stores sufficient heat transfer medium inside the receiving groove 3211 to ensure excellent heat transfer performance, but also creates a physical barrier through the narrow gap at the inner end, preventing the heat transfer medium from leaking outwards from the end, thus improving the sealing performance and operational reliability of the gating jacket 3 assembly.

[0043] To achieve mutual positioning between the ingate tube 31 and the outer cooling sleeve 32, and to further prevent leakage of the heat transfer medium, a limiting ring 33 is provided on the inner side of at least one end of the outer cooling sleeve 32. The limiting ring 33 is coaxially sleeved on the ingate tube 31, and the two are interference-fitted to ensure a firm connection and prevent relative sliding. At the same time, an annular limiting groove 3221 corresponding to the position of the limiting ring 33 is machined on the inner side of the outer cooling sleeve 32. The outer circumference of the limiting ring 33 passes into the corresponding annular limiting groove 3221 and maintains a sliding fit with the annular limiting groove 3221. A small reserved expansion gap is left between the inner wall of the annular limiting groove 3221 and the corresponding limiting ring 33. The reserved expansion gap provides sufficient buffer space for the radial and axial expansion of the ingate tube 31 under heat, effectively avoiding the problem of the outer cooling sleeve 32 being damaged or even cracked due to the outward compression of the ingate tube 31. Furthermore, the physical dimensions of the reserved expansion gap are designed to be extremely narrow, effectively blocking and constraining the heat-conducting medium, preventing its passage and thus preventing leakage, significantly extending the service life of the gate sleeve 3. Preferably, limiting rings 33 are provided on the inner sides of both ends of the outer cooling sleeve 32 to enhance sealing. Alternatively, if a limiting ring 33 is only provided at one end of the outer cooling sleeve 32, it is positioned at the outer end to prevent leakage of the heat-conducting medium. The heat-conducting medium is preferably a material that is relatively viscous when melted.

[0044] Furthermore, the limiting ring 33 has an integrally formed limiting protrusion 331 on the side facing the receiving groove 3211. The limiting protrusion 331 extends into the annular limiting groove 3221 to form a limiting abutment fit with the inner wall of the annular limiting groove 3221. The limiting protrusion 331 not only limits the sliding position of the limiting ring 33, preventing the limiting ring 33 from falling out of the annular limiting groove 3221 and ensuring the stability of the sliding fit between the two; but also the setting of the limiting protrusion 331 makes the gap extension path between the limiting ring 33 and the annular limiting groove 3221 to be tortuous and maze-like, thereby further improving the ability to prevent the leakage of heat transfer medium.

[0045] like Figures 5 to 8 As shown, the outer cooling jacket 32 ​​has internal cooling channels for cooling water to circulate and lower the temperature. To significantly reduce the machining difficulty of the complex internal channels, the outer cooling jacket 32 ​​adopts a split-assembly structure, specifically including an annular body 321 and two annular end caps 322. The two annular end caps 322 are respectively fastened to the two opposite end faces of the annular body 321. The receiving groove 3211 is directly formed on the inner wall of the annular body 321. The internal cooling channels specifically include multiple first channels 3212 and multiple second channels. The multiple first channels 3212 are evenly distributed circumferentially in the internal tube wall of the annular body 321, extending parallel to the central axis, and both ends of the first channels 3212 directly penetrate the two end faces of the annular body 321. Multiple recessed cooling grooves 3213 are machined on the opposite end faces of the annular body 321, and any cooling groove 3213 is laterally connected to two adjacent first channels 3212. Along the circumferential direction of the annular body 321, all cooling grooves 3213 are arranged sequentially, with adjacent cooling grooves 3213 located on opposite end faces of the annular body 321. The annular end cap 322, after being assembled, fits tightly against the cooling grooves 3213 on its end face, forming a closed second flow channel. Furthermore, the annular body 321 of the outer cooling sleeve 32, or one of the annular end caps 322, is also provided with an inlet 3222 and an outlet 3223 communicating with the first flow channel 3212. This split structure allows for extremely convenient machining of the straight first flow channel 3212 and surface cooling grooves 3213 at the end of the annular body 321 using conventional machine tools. After being assembled with the annular end cap 322, these elements combine to form a complex and continuous internal cooling circuit, significantly reducing manufacturing costs while ensuring efficient cooling of the inner gating pipe 31. During cooling, cooling water enters one of the first flow channels 3212 from the inlet 3222, and flows alternately through the second flow channel and the first flow channel 3212, and finally flows out of the outlet 3223 from the other first flow channel 3212.

[0046] A metal sealing gasket can be provided between the annular body 321 and the annular end cap 322 to prevent cooling water leakage; or after the production of the annular body 321 and the annular end cap 322 is completed, the annular body 321 and the annular end cap 322 are welded together, thereby completely eliminating the potential for cooling water leakage.

[0047] The two annular end caps 322 may have the same or different shapes. Specifically, to facilitate the disassembly and maintenance of the sprue sleeve 3, at least one of the two annular end caps 322 is designed as a detachable assembly, including an end cap body 3224 and a limiting cap 3225. The end cap body 3224 is fitted and fixed to the end face of the annular body 321, and the limiting cap 3225 is detachably fixed to the side of the end cap body 3224 away from the annular body 321 by countersunk screws. After the limiting cap 3225 and the end cap body 3224 are joined, their inner surfaces together form the annular limiting groove 3221 mentioned above. The detachable design of the limiting cap 3225 allows the originally closed annular limiting groove 3221 to be opened directly, allowing components such as the ingate 31, the limiting ring 33, and the outer cooling sleeve 32 to be smoothly separated. This makes it quicker and more convenient to replace or maintain parts, effectively reducing the difficulty and cost of daily mold maintenance.

[0048] In practical applications, the heat-conducting medium filled in the receiving groove 3211 can typically be a thermoplastic heat-conducting medium, such as a low-melting-point metal like a tin-bismuth alloy or a thermoplastic phase-change thermal paste. The thermoplastic heat-conducting medium is solid at room temperature, completely eliminating leakage problems when the mold is stopped at room temperature. However, under the high-temperature operating conditions of die casting, it melts and transforms into a liquid state, allowing it to better adhere to the surfaces of the inner gating tube 31 and the outer cooling jacket 32, achieving excellent heat conduction. Simultaneously, the heat-conducting medium does not completely fill the receiving groove 3211; the liquid medium can adaptively flow when the inner gating tube 31 expands and is compressed by heat, fully leveraging the dual protection of efficient heat transfer and preventing the outer cooling jacket 32 ​​from cracking.

[0049] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A die-casting mold for the production of automotive parts, characterized in that, include: Moving mold (1), fixed mold (2), sprue bushing (3) and venting assembly (5); The moving mold (1) and the fixed mold (2) are configured to close together to form a cavity (11), a runner (12), and an overflow groove (13) between them; the cavity (11) surrounds the runner (12); the runner (12) and the overflow groove (13) are both connected to the cavity (11), and there are multiple connections between the runner (12) and the cavity (11); The sprue sleeve (3) is located in the middle of the fixed mold (2), and the sprue sleeve (3) is connected to the horizontal runner (12); the sprue sleeve (3) includes an ingate (31), an outer cooling sleeve (32), and a limiting ring (33). The outer cooling sleeve (32) is fitted on the outside of the ingate (31) with a gap between them, and a heat-conducting medium is filled between the ingate (31) and the outer cooling sleeve (32); the limiting ring (33) is provided on the inner side of at least one end of the outer cooling sleeve (32); the limiting ring (33) is fitted on the ingate (31) The outer cooling sleeve (32) is provided with an annular limiting groove (3221) corresponding to the limiting ring (33) on its inner side. The outer side of the limiting ring (33) passes into the corresponding annular limiting groove (3221) and slides with the annular limiting groove (3221). There is a reserved expansion gap between the inner wall of the annular limiting groove (3221) and the corresponding limiting ring (33). The reserved expansion gap is configured to prevent the heat-conducting medium from passing through. The outer cooling sleeve (32) has a cooling flow channel inside. The exhaust assembly (5) is connected to the overflow trough (13).

2. The die-casting mold for automobile parts production according to claim 1, characterized in that: The outer cooling jacket (32) has a receiving groove (3211) for receiving the heat-conducting medium in the middle of its inner side; the distance between the inner end of the outer cooling jacket (32) and the inner gating pipe (31) is smaller than the distance between the bottom of the receiving groove (3211) and the inner gating pipe (31). The distance between the inner end of the outer cooling jacket (32) and the inner gating pipe (31) is configured to prevent the heat-conducting medium from passing through.

3. The die-casting mold for automotive parts production according to claim 2, characterized in that: The limiting ring (33) has a limiting protrusion (331) on the side facing the receiving groove (3211), and the limiting protrusion (331) is used to limit the engagement with the inner wall of the corresponding annular limiting groove (3221).

4. The die-casting mold for automobile parts production according to claim 2, characterized in that: The outer cooling jacket (32) includes an annular body (321) and two annular end caps (322), with the two annular end caps (322) respectively located at opposite ends of the annular body (321); The receiving groove (3211) is located on the inner side of the annular body (321); The cooling channel includes multiple first channels (3212) and multiple second channels; the multiple first channels (3212) are spaced apart circumferentially on the annular body (321), and both ends of the first channels (3212) penetrate the annular body (321); multiple cooling grooves (3213) are provided at opposite ends of the annular body (3211), and each cooling groove (3213) has two adjacent first channels (3212) communicating with it; the multiple cooling grooves (3213) are arranged sequentially circumferentially along the annular body (3211), and two adjacent cooling grooves (3213) are located on opposite sides of the annular body (3211); the annular end cap (322) and the cooling grooves (3213) together constitute the second channel; The outer cooling jacket (32) is provided with an inlet (3222) and an outlet (3223) that communicate with the first flow channel (3212).

5. The die-casting mold for automotive parts production according to claim 4, characterized in that: At least one of the annular end caps (322) includes an end cap body (3224) and a limiting cap (3225), wherein the limiting cap (3225) is detachably disposed on the side of the corresponding end cap body (3224) away from the annular body (321); the limiting cap (3225) and the corresponding end cap body (3224) together constitute the annular limiting groove (3221).

6. The die-casting mold for automobile parts production according to claim 1, characterized in that: The heat-conducting medium is a thermoplastic heat-conducting medium.

7. The die-casting mold for automobile parts production according to claim 1, characterized in that: The moving mold (1) is provided with a groove that communicates with the cavity (11); The die-casting mold further includes an opening assembly (4), which includes a drive member (41), a wedge (42), and a rod (43); the wedge (42) is slidably disposed in the groove, and one end of the rod (43) is connected to the wedge (42); the drive member (41) is connected to the wedge (42) and is used to drive the wedge (42) and the rod (43) to move so that one end of the rod (43) away from the wedge (42) passes into the cavity (11).

8. The die-casting mold for automobile parts production according to claim 1, characterized in that: The exhaust assembly (5) includes an exhaust block (51) disposed in the overflow groove (13); one of the fixed mold (2) and the moving mold (1) is connected to the exhaust block (51), and the other of the fixed mold (2) and the moving mold (1) has an exhaust gap with the exhaust block (51).

9. The die-casting mold for automobile parts production according to claim 8, characterized in that: The exhaust assembly (5) also includes a vacuum generator (52) and an exhaust pipe (53), wherein the vacuum generator (52) is connected to the end of the overflow groove (13) away from the cavity (11) through the exhaust pipe (53).

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