Die-casting die and die-casting process for automobile aluminum alloy cooling fin

Abstract

The invention relates to the technical field of die-casting dies, in particular to an automobile aluminum alloy cooling fin die-casting die and die-casting technology.The automobile aluminum alloy cooling fin die-casting die comprises a first die and a second die, the second die is provided with a forming cavity, the automobile aluminum alloy cooling fin die-casting die further comprises an exhaust part, and the exhaust part is arranged on the second die and provided with a gas storage cavity; the gas storage cavity communicates with the forming cavity, in the aluminum alloy cooling fin die-casting process, along with continuous injection of molten metal liquid into the forming cavity, gas in the forming cavity can be pressed into the gas storage cavity, and it is ensured that when the forming cavity is filled with the molten metal liquid, the interior of the forming cavity is in a gas-free state; by means of the self-adaptive integrated structure, gas in the forming cavity is efficiently exhausted in the die-casting process, the defects of pinholes and shrinkage porosity caused by unsmooth exhaust are thoroughly overcome, and the compactness, the heat conductivity and the structural strength of the aluminum alloy cooling fin are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of die-casting dies, and in particular to a die-casting die and a die-casting process for an automotive aluminum alloy radiator. Background Art

[0002] The automobile radiator consists of three parts: the water inlet chamber, the water outlet chamber and the radiator core. It is a component of the automobile water-cooled engine cooling system. The coolant inside the automobile radiator cooling tube circulates internally and the forced convection heat exchange formed by the operation of the external fan takes away a large amount of heat energy, so that the engine can work normally under common working conditions and prevent the engine from overcooling or overheating. Among them, the automobile radiator is an indispensable and important component of the automobile radiator. Most automobile radiators are made of aluminum alloy structures and are usually die-cast. When die-casting aluminum alloy automobile radiators, the mold has poor exhaust, which will lead to gas retention, forming pinholes or internal shrinkage in the finished automobile radiator, reducing the thermal conductivity and structural strength of the automobile radiator. In view of this, we propose a die-casting mold and die-casting process for automobile aluminum alloy radiators. Summary of the Invention

[0003] To achieve the above-mentioned objectives, the present invention provides a die-casting mold for an automotive aluminum alloy heat sink, which is used for the die-casting preparation of aluminum alloy heat sinks. The mold comprises a first mold and a second mold. The second mold is provided with a molding cavity and an exhaust portion. The exhaust portion is provided on the second mold, and the exhaust portion has a gas storage cavity. The gas storage cavity is connected to the molding cavity. During the die-casting process of the aluminum alloy heat sink, as the molten metal liquid continues to be injected into the molding cavity, the gas in the molding cavity will be pressed into the gas storage cavity to ensure that when the molten metal liquid fills the molding cavity, the molding cavity is in a gas-free state.

[0004] Optionally, the exhaust part includes a top box, which is movably inserted into the mounting hole on the second mold, and the top of the top box is arranged to be in conflict with the step provided at the top of the mounting hole, and the top box and the step are fixedly connected by fixing screws, and a middle box is movably inserted into the bottom plate of the top box, and the middle box is fixed on the top plate of the bottom box, and a connecting hole for connecting the middle box and the bottom box is provided on the bottom box, and a connecting bottom plate is fixedly inserted into the bottom plate of the bottom box, and an air guide hole is provided on the connecting bottom plate, and the bottom box is movably inserted into the mounting hole, and the inner cavity of the top box, the inner cavity of the middle box and the inner cavity of the bottom box constitute the gas storage chamber.

[0005] Optionally, a movable groove is provided at the top of the forming cavity, the bottom box is an inverted T-shaped structure, and the transverse section of the bottom box is movably inserted into the movable groove, wherein the height of the movable groove is consistent with the height of the transverse section of the bottom box.

[0006] Optionally, the diameter of the air guide holes is between 0.01 mm and 0.03 mm.

[0007] Optionally, it further includes an air leakage hole, which is arranged on the top plate of the top box. There are several air leakage holes, and a one-way valve is arranged in the air leakage hole. The air leakage hole is connected to the inner cavity of the top box.

[0008] Optionally, it further includes an air extraction hole, which is provided on the top plate of the top box and is connected to the inner cavity of the top box.

[0009] Optionally, a filter is provided on the inner top wall and / or the outer top wall of the top box, and the filter covers the air leakage hole.

[0010] Optionally, it also includes a guide reset portion, which includes a transverse plate fixed on the top of the middle box, and a reset assembly arranged between the transverse plate and the inner bottom wall of the top box, the reset assembly includes a reset rod connected to the lower end surface of the transverse plate, the reset rod is movably inserted in the reset cylinder, the reset cylinder is fixed on the inner bottom wall of the top box, a reset spring is wound around the reset rod, and the two ends of the reset spring are respectively fixedly connected to the side wall of the reset rod and the outer side wall of the reset cylinder.

[0011] Optionally, it also includes a blocking part, which includes a support rod, the upper end of the support rod is fixedly set on the inner top wall of the top box, the lower end of the support rod is fixedly connected to the support plate, and the blocking rod is fixedly set on the lower end surface of the support plate, and the number of the blocking rods is matched with the number of the air guide holes.

[0012] To achieve the above object, the present invention further provides a die-casting process for an automotive aluminum alloy radiator, comprising the aforementioned automotive aluminum alloy radiator die-casting mold, and comprising the following steps:

[0013] S: When the molten metal does not contact the bottom surface of the connecting base plate, as the molten metal continues to be injected, the gas in the molding cavity will be pressed into the gas storage cavity through the gas guide hole to achieve the purpose of exhaust;

[0014] S: When the molten metal contacts the bottom surface of the connecting bottom plate, as the molten metal continues to be injected, the molten metal cannot enter the air guide holes due to the surface tension and viscosity of the air guide holes, because the size of the air guide holes is between 0.01mm and 0.03mm. Therefore, the molten metal will push the connecting bottom plate and the bottom box upward into the movable tank.

[0015] S: As the bottom box moves upward, the blocking rod will enter the air guide hole. When the top plate of the bottom box contacts the top wall of the movable groove, the lower edge of the bottom box and the top wall of the molding cavity are in the same plane, and the lower end of the blocking rod and the lower edge of the air guide hole are in the same plane.

[0016] The beneficial effects of the present invention are as follows:

[0017] The present invention uses an adaptive integrated structure to achieve efficient exhaust of gas in the molding cavity during the die-casting process, completely solving the pinhole and shrinkage defects caused by poor exhaust, significantly improving the density, thermal conductivity and structural strength of the aluminum alloy heat sink, while simplifying the mold structure, extending the service life and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of an embodiment of a die-casting mold for an automotive aluminum alloy heat sink of the present invention;

[0019] Figure 2 This is the die-casting mold for the automotive aluminum alloy radiator of the present invention Figure 1 A schematic diagram of a partial cross-sectional structure of the second mold from the right side;

[0020] Figure 3 This is the die-casting mold for the automotive aluminum alloy radiator of the present invention Figure 2 A magnified schematic diagram of the structure A;

[0021] Figure 4 This is the die-casting mold for the automotive aluminum alloy radiator of the present invention Figure 3 A magnified schematic diagram of the B structure;

[0022] Figure 5 The figure is a flow chart of the die-casting process of the automotive aluminum alloy radiator of the present invention.

[0023] Description of Reference Numerals

[0024] First mold 1, second mold 2, molding cavity 21, movable groove 22, mounting hole 23, step 24, exhaust part 3, top box 31, air vent 311, exhaust hole 312, middle box 32, bottom box 33, connecting hole 34, connecting bottom plate 35, air guide hole 36, fixing screw 37, filter 38, guide reset part 4, transverse plate 41, reset assembly 42, reset rod 421, reset cylinder 422, reset spring 423, blocking part 5, support rod 51, support plate 52, blocking rod 53. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs. The words "including" and similar words used in this article mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0026] In response to the problems existing in the prior art, an embodiment of the present invention provides a die-casting mold for automotive aluminum alloy heat sinks, which is used for the die-casting preparation of aluminum alloy heat sinks. The present invention integrates an integrated structure of microporous air guide, dynamic exhaust storage and self-resetting unblocking to achieve efficient discharge of gas from the molding cavity 21 during the die-casting process, zero infiltration of molten metal and automatic cleaning of the air guide holes, completely solving the pinhole and shrinkage defects caused by poor exhaust, significantly improving the density, thermal conductivity and structural strength of the aluminum alloy heat sink, while simplifying the mold structure, extending the service life and reducing production costs.

[0027] Specifically, if Figure 1 As shown, the automotive aluminum alloy radiator die-casting mold includes a first mold 1 and a second mold 2. The second mold 2 is provided with a forming cavity 21. The first mold 1 is also provided with an injection hole. When the first mold 1 and the second mold 2 are closed, molten metal liquid is injected into the forming cavity 21 through the injection hole, and finally the automotive aluminum alloy radiator is die-casted.

[0028] Furthermore, if Figure 1 As shown, the automotive aluminum alloy radiator die casting mold further includes an exhaust portion 3, which is provided on the second mold 2. Figure 1 In this example, the exhaust portion 3 is located on the top of the second mold 2. The exhaust portion 3 has a gas storage cavity, preferably, the gas storage cavity is disposed inside the exhaust portion 3. The gas storage cavity is interconnected with the molding cavity 21. During the die-casting process of the aluminum alloy heat sink, as the molten metal is continuously injected into the molding cavity 21, the gas in the molding cavity 21 is pressed into the gas storage cavity, ensuring that when the molten metal fills the molding cavity 21, the molding cavity 21 is free of gas.

[0029] This embodiment eliminates the need for an additional power source during the exhaust process. During the molten metal hydraulic casting process, the exhaust is accomplished by utilizing the inherent high pressure of the molten metal's hydraulic pressure. Compared to the prior art, the presence of the gas storage chamber in this embodiment effectively removes gas from the forming cavity 21, thereby resolving the prior art issue of pinholes or internal shrinkage in the molded parts of automotive aluminum alloy heat sinks caused by the presence of gas in the forming cavity 21.

[0030] In one embodiment, Figure 2 and Figure 3 As shown, the exhaust portion 3 includes a top box 31, which is movably inserted into the mounting hole 23 on the second mold 2. It should be noted that the top box 31 is matched with the mounting hole 23, and the side walls of the top box 31 and the side walls of the mounting hole 23 are slidably arranged with each other, and the gap between the side walls of the top box 31 and the mounting hole 23 is almost negligible. The purpose of this arrangement is to prevent liquid leakage and gas entry.

[0031] Furthermore, the top of the top box 31 is arranged to conflict with the step 24 provided at the top of the mounting hole 23, and the top box 31 and the step 24 are fixedly connected by fixing screws 37. In this example, the top box 31 forms an axial limit with the step 24 through the top surface, and is detachably fastened by the fixing screws 37, which not only ensures zero displacement and zero leakage of the exhaust module during high-pressure injection, but also can be quickly removed as a whole by only loosening the screws during maintenance, greatly shortening the disassembly and assembly time and reducing downtime costs. At the same time, the rigid support of the step 24 significantly disperses the clamping force and extends the life of the mold.

[0032] Furthermore, a middle box 32 is movably connected to the bottom plate of the top box 31. The setting of this example enables the middle box 32 to move up and down in the vertical direction relative to the top box 31; the middle box 32 is fixed on the top plate of the bottom box 33. The purpose of this setting is to ensure that the middle box 32 and the bottom box 33 can move as a whole.

[0033] Furthermore, a connecting hole 34 for connecting the middle box 32 and the bottom box 33 is provided on the bottom box 33, a connecting bottom plate 35 is fixedly plugged into the bottom plate of the bottom box 33, and an air guide hole 36 is provided on the connecting bottom plate 35. The bottom box 33 is movably plugged into the mounting hole 23, and the inner cavity of the top box 31, the inner cavity of the middle box 32 and the inner cavity of the bottom box 33 constitute the gas storage cavity.

[0034] In this example, efficient exhaust of cavity gas during the die-casting process is achieved by integrating microporous gas guides and dynamic exhaust storage. Furthermore, this structure connects the inner cavities of the top box 31, middle box 32, and bottom box 33 in series through a connecting hole 34 to form an integrated gas storage chamber. This allows the high-pressure gas discharged from the molding cavity 21 to be instantly dispersed into a larger volume, rapidly reducing the peak pressure and avoiding local overpressure. The connecting base plate 35 is fixed to the bottom box 33 in a removable plug-in manner, which not only facilitates the rapid replacement of wear parts, but also directly connects the gas guide holes 36 to the storage chamber, shortening the exhaust path and improving exhaust efficiency. The entire storage chamber maintains a precise sliding fit with the mold mounting hole 23, taking into account both sealing and floating travel, achieving a continuous, stable, and leak-free exhaust cycle, thereby effectively eliminating porosity defects and improving the molding quality and mold life of the aluminum alloy heat sink.

[0035] In a specific application, in order to ensure that the top of the molded part remains flat and the quality of the finished part is guaranteed, in one embodiment, as Figure 2 and Figure 3 As shown, a movable groove 22 is defined at the top of the molding cavity 21. The bottom box 33 is an inverted T-shaped structure, with the transverse section of the bottom box 33 movably inserted into the movable groove 22. The height of the movable groove 22 is consistent with the height of the transverse section of the bottom box 33. It is worth noting that the vertical section of the bottom box 33 is movably disposed within the mounting hole 23, and the gap between the mounting hole 23 and the bottom box 33 is almost negligible.

[0036] The arrangement of this embodiment can ensure that the movable groove 22 and the transverse section of the inverted T-shaped bottom box 33 are matched with zero clearance and high precision. When the bottom box 33 reaches the upper end point, its lower end face is completely flush with the top wall of the molding cavity 21, completely eliminating the indentation or burr caused by the protrusion of the exhaust mechanism, and ensuring that the top of the heat sink is flat; at the same time, the transverse section forms a rigid guide in the movable groove 22, and cooperates with the extremely small gap between the vertical section and the mounting hole 23, so that the bottom box 33 can maintain verticality and no shaking throughout the whole process, which not only prevents the infiltration of molten metal and causes jamming, but also extends the life of the mold, and ultimately achieves high-quality, burr-free continuous die-casting.

[0037] In order to ensure that the air guide holes 36 can only allow gas to pass through and cannot allow molten metal to pass through, in one embodiment, as shown in FIG. Figure 4As shown, the aperture of the gas-guiding hole 36 is between 0.01mm and 0.03mm. At this size, the gas-guiding hole 36 only allows gas to pass into the inner cavity of the bottom box 33, but prevents the molten metal from entering the inner cavity of the bottom box 33. This is because when the molten metal reaches the gas-guiding hole 36 under the injection pressure, the molten metal (which can be understood as the aluminum alloy liquid) forms a significant surface tension-capillary equilibrium at the front end of the 0.01mm-0.03mm micropore. This aperture is much smaller than the critical escape radius (approximately 0.05mm) of the aluminum alloy melt in this temperature range (≈680°C-720°C), making it impossible for the molten metal to overcome surface tension and viscous resistance and enter the micropore. At the same time, the mean free path of the gas molecules is on the same order of magnitude as the aperture, allowing for smooth Knudsen flow of the gas, thus achieving the one-way channel function of "exhaust-only, liquid-proof."

[0038] In actual use, the gas in the molding cavity 21 will be discharged into the gas storage cavity, and the discharged gas has the characteristics of high pressure. In order to prevent the safety risks caused by excessive pressure in the gas storage cavity, in one embodiment, as shown in FIG. Figure 1 and Figure 2 As shown, the automotive aluminum alloy heat sink die-casting mold further includes a plurality of air vents 311 disposed on the top plate of the top box 31. Each air vent 311 is equipped with a one-way valve, and the air vents 311 communicate with the inner cavity of the top box 31. The provision of these air vents 311 allows high-pressure gas accumulated in the gas storage chamber to be safely and directionally discharged to the exterior of the mold via the one-way valve during the die-casting process, preventing overpressure in the cavity. The one-way valve only allows gas to escape while preventing the influx of external air, ensuring the safety of the mold and personnel while maintaining a continuous negative pressure exhaust environment in the molding cavity 21. This further reduces the risk of defects such as pores and shrinkage in the aluminum alloy heat sink.

[0039] In order to cooperate with the work of the vent hole 311 to achieve the effect of efficiently exhausting the gas in the gas storage chamber, in one embodiment, as shown in FIG. Figure 1 and Figure 2As shown, the automotive aluminum alloy heat sink die-casting mold also includes an exhaust hole 312, located on the top plate of the top box 31 and communicating with the inner cavity of the top box 31. In one example, the exhaust hole 312 is interconnected with an external exhaust pump. During operation, the exhaust pump continuously applies negative pressure to the gas storage chamber through the exhaust hole 312, creating an active exhaust flow. This synergistic effect works with the one-way pressure relief provided by the bleed hole 311: when the pressure within the chamber exceeds a set value, the one-way valve in the bleed hole 311 automatically opens, instantly releasing the peak pressure. When the pressure within the chamber falls below the set value, the exhaust pump maintains a negative pressure environment, accelerating the exhaust of residual gas. This dual-channel "passive pressure relief + active exhaust" mode maintains a low pressure and low residual gas in the gas storage chamber throughout the die-casting cycle, shortening exhaust time and improving mold filling efficiency. It also further reduces the risk of porosity and flow marks in aluminum alloy parts, avoids fatigue failure caused by frequent opening and closing of the one-way valve, and extends the mold maintenance cycle.

[0040] During operation, in order to prevent dust or particles in the environment from entering the gas storage chamber through the air leakage hole 311, thereby affecting the quality of the molded part, in one embodiment, as shown in FIG. Figure 2 and Figure 3 As shown, a filter 38 is provided on the inner top wall and / or outer top wall of the top box 31, and the filter 38 covers the air vent 311. In one example, the filter 38 is provided on the inner top wall of the top box 31 or on the outer top wall of the top box 31; in another example, the filter 38 is provided on both the inner top wall and the outer top wall of the top box 31; the provision of the filter 38 can double-intercept the bidirectional airflow during the pressure relief process: the external filter blocks the entry of ambient dust, and the internal filter prevents metal chips or release agent volatiles that may exist in the cavity from escaping in the reverse direction, thereby preventing particulate matter from clogging the one-way valve, contaminating the molding cavity, or adhering to the surface of the heat sink. Both levels of filter screens are woven with high-temperature resistant stainless steel fibers, with a pore size of ≤5μm and an air permeability of ≥90%, which not only ensures exhaust efficiency but also enables tool-free quick disassembly and cleaning, ensuring that clean exhaust and stable molding quality are maintained over the long term during the die-casting cycle.

[0041] After the molded part is separated from the mold, in order to enable the various structures of the device to be reset to the initial position, in one embodiment, as shown in FIG. Figure 2 and Figure 3 As shown, the automotive aluminum alloy heat sink die-casting mold further includes a guide reset portion 4, which includes a transverse plate 41 fixed to the top of the middle box 32 and a reset assembly 42 disposed between the transverse plate 41 and the inner bottom wall of the top box 31. The provision of the guide reset portion 4 enables the upward movement path of the middle box 32 to be reset to its initial position after the molded part is demolded.

[0042] Specifically, the reset assembly 42 includes a reset rod 421 connected to the lower end surface of the transverse plate 41, the reset rod 421 is movably inserted in the reset cylinder 422, and the reset cylinder 422 is fixedly set on the inner bottom wall of the top box 31. A reset spring 423 is wound around the outside of the reset rod 421, and the two ends of the reset spring 423 are respectively fixedly connected to the side wall of the reset rod 421 and the outer side wall of the reset cylinder 422.

[0043] The reset assembly 42, through the precise guidance of the reset rod 421 and the reset cylinder 422, ensures that the bottom box 33, propelled by the molten metal, rises and falls stably in the vertical direction, preventing lateral sway. The reset spring 423, with fixed ends, quickly releases its compressed potential energy after die-casting, driving the bottom box 33 to precisely reset and ensure the alignment of the air guide hole 36 and the clearing rod 53, preventing sticking. This integrated guide-reset design not only improves the cycle reliability of the exhaust system, but also reduces mechanical wear, extending the maintenance cycle and service life of the mold.

[0044] During the continuous die-casting process, the 0.01mm-0.03mm air ducts 36 are easily clogged by trace amounts of aluminum chips, oxides, or mold release agent residues. Once clogged, the air ducts 36 will not be able to vent smoothly, resulting in air suffocation in the molding cavity 21, and eventually forming defects such as pores and cold shuts on the surface or inside the heat sink. At the same time, manual cleaning requires stopping the machine and removing the mold, which is time-consuming and labor-intensive. Therefore, an online self-cleaning mechanism that is linked to the mold action is required to ensure that the air ducts 36 are unobstructed before each mold closing. In one embodiment, Figure 3 and Figure 4 As shown, the automotive aluminum alloy radiator die-casting mold also includes a blocking portion 5, which includes a support rod 51. The upper end of the support rod 51 is fixedly arranged on the inner top wall of the top box 31, and the lower end of the support rod 51 is fixedly connected to a support plate 52. A blocking rod 53 is fixedly arranged on the lower end surface of the support plate 52, and the number of the blocking rods 53 is matched with the number of the air guide holes 36.

[0045] In this embodiment, the clearing and blocking portion 5 precisely matches the lifting stroke of the bottom box 33. When the bottom box 33 is lifted by the molten metal, the clearing rod 53 automatically inserts into the air guide hole 36, achieving "instant clearing" of the blockage during the mold, eliminating downtime for maintenance. Furthermore, the rigid transmission of the support rod 51, support plate 52, and clearing rod 53 ensures a stable vertical clearing force without damaging the orifice. Furthermore, the clearing and blocking portion 5 maintains the micropores unobstructed for a long time, ensuring consistently designed exhaust efficiency, significantly reducing scrap rates, and improving production cycle time and overall mold reliability.

[0046] It should be noted that when the molten metal does not contact the lower end surface of the connecting bottom plate, the blocking rod 53 will not enter the gas guide hole 36, and the gas will be discharged into the gas storage chamber. When the molten metal contacts the lower end surface of the connecting bottom plate, the blocking rod 53 will enter the gas guide hole 36 to clear the gas guide hole 36.

[0047] In one example, the height of the air guide hole 36 is 1.5mm-3mm, and its upper and lower ends are flush with the inner cavities of the molding cavity 21 and the bottom box 33, respectively. Within this size range, the air guide hole 36 forms an extremely short, uniform-diameter straight-through channel. During the die-casting process, gas can be completely pressed into the gas storage cavity within milliseconds, leaving no dead corners. At the same time, this height ensures that the clearing rod 53 has sufficient insertion depth to completely remove attachments from the air guide hole 36, while also avoiding increased gas flow resistance due to excessive length. This ensures that each exhaust is "zero residue and zero blockage," keeping the molding cavity 21 in an ideal airless state throughout the filling phase.

[0048] In view of the problems existing in the prior art, the embodiments of the present invention further provide a die-casting process for automobile aluminum alloy radiating fins, such as Figure 5 As shown, the automotive aluminum alloy heat sink die-casting mold includes the following steps:

[0049] S1: When the molten metal does not contact the bottom surface of the connecting bottom plate 35, as the molten metal continues to be injected, the gas in the molding cavity 21 is pressed into the gas storage cavity through the gas guide hole 36 to achieve the purpose of exhaust;

[0050] S2: When the molten metal contacts the bottom surface of the connecting bottom plate 35, as the molten metal continues to be injected, the molten metal cannot enter the air guide holes 36 due to the surface tension and viscosity of the air guide holes 36, because the size of the air guide holes 36 is between 0.01mm and 0.03mm. Therefore, the molten metal pushes the connecting bottom plate 35 and the bottom box 33 upward into the movable groove 22;

[0051] S3: As the bottom box 33 moves upward, the blocking rod 53 will enter the air guide hole 36. When the top plate of the bottom box 33 contacts the top wall of the movable groove 22, the lower edge of the bottom box 33 and the top wall of the molding cavity 21 are in the same plane, and the lower end of the blocking rod 53 and the lower edge of the air guide hole 36 are in the same plane.

[0052] Through the sequential steps S1-S3 described above, the present invention achieves closed-loop control at the three key nodes of the process: venting, sealing, and cleaning. This process configuration offers the following significant benefits: Zero-retention venting: In stage S1, 0.01–0.03 mm micropores are utilized to instantly direct all high-pressure gas within the molding cavity 21 into the gas storage chamber before the arrival of the molten metal, eliminating the potential risks of pores and shrinkage. Self-sealing and anti-seepage: In stage S2, the molten metal is unable to enter the micropores due to surface tension, instead pushing the bottom box 33 upward, achieving automatic mechanical sealing while preventing metal from clogging the venting channel. Online self-cleaning: In stage S3, the clearing rod 53 is simultaneously inserted into the air guide hole 36, removing any attachments within the hole before mold closing, ensuring unobstructed micropores for the next cycle and eliminating manual mold removal and maintenance. Precise repositioning: The upper limit of the bottom box 33 is flush with the top wall of the molding cavity 21, and the lower limit of the clearing rod 53 is flush with the lower edge of the air guide hole 36. This ensures that the heat sink is fully formed without bosses and prevents mold damage caused by overshoot during repositioning.

[0053] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations of these embodiments are possible. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention. Furthermore, the invention described herein is susceptible to other embodiments and may be practiced or implemented in a variety of ways.

Claims

1. A die-casting mold for automotive aluminum alloy radiator, characterized in that: The invention is used for the die-casting preparation of aluminum alloy heat sinks, comprising a first mold (1) and a second mold (2), wherein the second mold (2) is provided with a molding cavity (21), and further comprising an exhaust portion (3), wherein the exhaust portion (3) is provided on the second mold (2), and the exhaust portion (3) has a gas storage cavity, wherein the gas storage cavity is communicated with the molding cavity (21), and during the die-casting process of the aluminum alloy heat sink, as molten metal liquid is continuously injected into the molding cavity (21), the gas in the molding cavity (21) is pressed into the gas storage cavity, thereby ensuring that when the molten metal liquid fills the molding cavity (21), the molding cavity (21) is in a gas-free state.

2. The automotive aluminum alloy radiator die-casting mold according to claim 1, characterized in that: The exhaust portion (3) includes a top box (31), the top box (31) is movably inserted into the mounting hole (23) on the second mold (2), and the top of the top box (31) and the step (24) provided at the top of the mounting hole (23) are mutually opposed. The top box (31) and the step (24) are fixedly connected by fixing screws (37). A middle box (32) is movably inserted on the bottom plate of the top box (31), and the middle box (32) is fixed on the bottom plate. The top plate of the box (33) is provided with a connecting hole (34) for connecting the middle box (32) and the bottom box (33), the bottom plate of the bottom box (33) is fixedly plugged with a connecting bottom plate (35), the connecting bottom plate (35) is provided with an air guide hole (36), the bottom box (33) is movably plugged into the mounting hole (23), and the inner cavity of the top box (31), the inner cavity of the middle box (32) and the inner cavity of the bottom box (33) constitute the gas storage cavity.

3. The automotive aluminum alloy radiator die-casting mold according to claim 2, characterized in that: A movable groove (22) is provided at the top of the molding cavity (21), and the bottom box (33) is in an inverted T-shaped structure. The transverse section of the bottom box (33) is movably inserted into the movable groove (22), wherein the height of the movable groove (22) is consistent with the height of the transverse section of the bottom box (33).

4. The automotive aluminum alloy radiator die-casting mold according to claim 2, characterized in that: The diameter of the air guide hole (36) is between 0.01 mm and 0.03 mm.

5. The automotive aluminum alloy radiator die-casting mold according to claim 2, characterized in that: The invention also includes an air leakage hole (311), which is provided on the top plate of the top box (31). There are a plurality of air leakage holes (311), a one-way valve is provided in the air leakage hole (311), and the air leakage hole (311) is communicated with the inner cavity of the top box (31).

6. The automotive aluminum alloy radiator die-casting mold according to claim 2, characterized in that: It also includes an air extraction hole (312), which is provided on the top plate of the top box (31), and the air extraction hole (312) is communicated with the inner cavity of the top box (31).

7. The automotive aluminum alloy radiator die-casting mold according to claim 5, characterized in that: A filter screen (38) is provided on the inner top wall and / or the outer top wall of the top box (31), and the filter screen (38) covers the air leakage hole (311).

8. The automotive aluminum alloy radiator die-casting mold according to claim 2, characterized in that: The invention also includes a guide reset portion (4), the guide reset portion (4) including a transverse plate (41) fixed on the top of the middle box (32), and a reset assembly (42) provided between the transverse plate (41) and the inner bottom wall of the top box (31), the reset assembly (42) including a reset rod (421) connected to the lower end surface of the transverse plate (41), the reset rod (421) being movably inserted into a reset cylinder (422), the reset cylinder (422) being fixedly provided on the inner bottom wall of the top box (31), a reset spring (423) being wound around the outside of the reset rod (421), and the two ends of the reset spring (423) being fixedly connected to the side wall of the reset rod (421) and the outer side wall of the reset cylinder (422), respectively.

9. The automotive aluminum alloy radiator die-casting mold according to claim 2, characterized in that: The invention also includes a blocking portion (5), wherein the blocking portion (5) includes a support rod (51), the upper end of the support rod (51) is fixedly arranged on the inner top wall of the top box (31), the lower end of the support rod (51) is fixedly connected to a support plate (52), and a blocking rod (53) is fixedly arranged on the lower end surface of the support plate (52), and the number of the blocking rods (53) matches the number of the air guide holes (36).

10. A die-casting process for automotive aluminum alloy radiator, characterized in that: The automotive aluminum alloy radiator die-casting mold according to any one of claims 1 to 2, claim 3, claim 4, claim 5, claim 6, claim 7, claim 8, or claim 9 comprises the following steps: S1: When the molten metal does not contact the bottom surface of the connecting bottom plate (35), as the molten metal continues to be injected, the gas in the molding cavity (21) is pressed into the gas storage cavity through the gas guide hole (36) to achieve the purpose of exhausting; S2: When the molten metal contacts the bottom surface of the connecting bottom plate (35), as the molten metal continues to be injected, the molten metal cannot enter the air guide hole (36) due to the surface tension and viscosity of the air guide hole (36), because the size of the air guide hole (36) is between 0.01mm and 0.03mm. Therefore, the molten metal pushes the connecting bottom plate (35) and the bottom box (33) upward into the movable groove (22); S3: As the bottom box (33) moves upward, the blocking rod (53) enters the air guide hole (36). When the top plate of the bottom box (33) contacts the top wall of the movable groove (22), the lower edge of the bottom box (33) and the top wall of the molding cavity (21) are in the same plane, and the lower end of the blocking rod (53) and the lower edge of the air guide hole (36) are in the same plane.

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