A high-precision magnesium alloy die casting die device

Abstract

The application relates to the technical field of die-casting production and manufacturing of metal parts, and particularly relates to a high-precision magnesium alloy die-casting die device. The device comprises a die mechanism, the die mechanism comprising a first die assembly, a second die assembly and a feeding mechanism, the first die assembly and the second die assembly being provided with a plurality of accommodation openings on the circumferential side, the accommodation openings being provided with liquid runners and cavities, the feeding mechanism comprising a feeding cylinder and a flow divider; a core, the core being located in the cavity during die closing; a core pulling assembly, the core pulling assembly being arranged in correspondence with the core; a overflow system, the overflow system comprising an overflow tank, an exhaust passage and an exhaust mechanism; the liquid runner comprising a first liquid runner and a second liquid runner, the first liquid runner being connected with a tail cavity of the metal part, and the second liquid runner being connected with a head cavity of the metal part. The die-casting metal part of the die device has high density and good surface finish, meets the application scenarios with high quality requirements, and can achieve the super-lightweight target in the low-altitude economic field, such as eVTOL, unmanned aerial vehicles and other aircrafts.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of die casting production and manufacturing of metal parts, and in particular to a high-precision magnesium alloy die casting mold device. BACKGROUND

[0002] Die casting is a metal casting process, and a die casting mold is key process equipment for pressure casting in manufacturing and plays an important role in many industrial fields. Die casting is characterized in that molten metal or alloy is injected into a mold for cooling and solidification through high-speed filling of the mold cavity by high pressure, and high-precision, high-strength and high-wear-resistant die castings can be manufactured through the die casting process, so die casting is widely used in the fields of automobiles, motorcycles, electronics, home appliances and the like.

[0003] However, among many metal die castings, magnesium alloy die casting is widely used and concerned due to its excellent lightweight, shock absorption and green recyclable performance, and has extended to become a key material for lightweight in the fields of aerospace, automobiles and the like. In particular, in the low-altitude economy field such as eVTOL, unmanned aerial vehicles and the like, the demand for weight reduction is particularly urgent in the industrialization process, and existing aluminum alloy structural parts cannot meet the super-lightweight target.

[0004] However, due to the chemical activity of magnesium, magnesium alloy die casting has higher process requirements compared with metal die casting materials such as aluminum alloy. Specifically, magnesium alloy has a strong affinity with oxygen in a molten state and is easily oxidized, and turbulent gas entrainment in the die casting process can easily cause magnesium alloy die cast parts to have problems such as porosity, cold shut, and affect the performance of the metal parts.

[0005] In particular, for magnesium alloy metal parts of special shapes, such as metal parts with a relatively long size, the ordinary die casting process is prone to technical problems such as turbulent gas entrainment, insufficient uniformity of metal liquid temperature distribution, and the like, which can cause the metal parts to have quality problems such as cold shut, shrinkage, rough surface and insufficient density, resulting in low production and manufacturing efficiency and not meeting the application scenarios of high-quality products. SUMMARY

[0006] In order to improve the product quality of magnesium alloy die cast metal parts in terms of product density, surface finish and the like, the application provides a high-precision magnesium alloy high-pressure die casting mold device, which can effectively avoid turbulent gas entrainment of metal liquid and at the same time improve the uniformity of metal liquid temperature, effectively improving the production quality and efficiency of magnesium alloy die cast parts.

[0007] The application adopts the following technical solutions:

[0008] The high-precision magnesium alloy die casting die device comprises a die mechanism with X, Y and Z axes along the length, width and thickness directions, a first die assembly, a second die assembly and a feeding mechanism, the first and second die assemblies are provided with a plurality of accommodation openings on the side, and a liquid runner and a cavity are arranged in the accommodation openings; the liquid runner is communicated with the feeding mechanism at one end and communicated with the cavity at the other end; the feeding mechanism comprises a feeding cylinder and a flow dividing cone; a core is arranged in the cavity when the first and second die assemblies are closed; a core pulling assembly is arranged corresponding to the core and comprises a fixing frame connected with the core and a driving device connected with the fixing frame; the metal part to be die cast comprises a head, a main body and a tail, and the metal part further comprises a main cavity penetrating through the main body and the tail; a overflow system comprises an overflow tank, an exhaust passage and an exhaust mechanism, the overflow tank is communicated with the cavity, the overflow tank comprises a ladle groove and an overflow sub-groove, the ladle groove and the overflow sub-groove are arranged on the two sides of the core respectively, the exhaust passage is communicated with the ladle groove, and the exhaust mechanism is arranged at the accommodation opening and communicated with the exhaust passage; the liquid runner comprises a first liquid runner and a second liquid runner, wherein the first liquid runner is communicated with the tail cavity of the metal part, and the second liquid runner is communicated with the head cavity of the metal part.

[0009] Optionally, the feeding cylinder is arranged on one side of the cavity, the feeding cylinder is provided with a first discharge hole and a second discharge hole at the lower bottom, the flow dividing cone is provided with a first flow channel groove and a second flow channel groove, the first and second flow channel grooves are arranged corresponding to the positions of the first and second discharge holes respectively, the first discharge hole and the first flow channel groove are communicated with the first liquid runner, and the second discharge hole and the second flow channel groove are communicated with the second liquid runner.

[0010] Optionally, the core comprises a main core and a sub-core, the main core corresponds to the main cavity of the metal part, and the sub-core corresponds to a sub-cavity of the head and / or tail structure of the metal part; the core pulling assembly comprises a main core pulling assembly and a sub-core pulling assembly, the main core pulling assembly is arranged corresponding to the main core, and the sub-core pulling assembly is arranged corresponding to the sub-core.

[0011] Optionally, one end of the main core connected with the main core pulling assembly is defined as a main core end, the first liquid runner comprises an extended liquid runner, the extended liquid runner is arranged on one side of the main core end close to the main core pulling assembly, and the direction of the extended liquid runner is adapted to the shape of the main core end.

[0012] Optionally, the head of the metal part further comprises a first through groove, the sub-core comprises a first sub-core and a second sub-core adapted to the first through groove of the head, and the first sub-core and the second sub-core are arranged along the Y-axis direction, wherein the first sub-core is arranged on one side of the feeding cylinder, and the sub-core pulling assembly comprises a first sub-core pulling assembly and a second sub-core pulling assembly, the first and second sub-core pulling assemblies are arranged corresponding to the first and second sub-cores respectively.

[0013] Optionally, the end of the first sub-core connected with the first sub-core pulling assembly is a first sub-core end, and the head cavity region corresponding to the first sub-core end is a first head cavity end, wherein the second liquid runner is in communication with the first head cavity end.

[0014] Optionally, the exhaust mechanism and the feeding cylinder are arranged on the two sides of the core respectively, and the overflow sub-channels and the feeding cylinder are arranged on the same side of the core, and the slag pocket channels include a plurality of channels, wherein the slag pocket channels close to the tail region are collected into a first exhaust passage, and the slag pocket channels close to the head region are collected into a second exhaust passage, and the first and second exhaust passages are collected into the exhaust mechanism.

[0015] Optionally, the mold device further comprises a pre-ejection mechanism configured to act on the die-cast metal part to pre-separate it from the core when the mold is opened.

[0016] Optionally, the pre-ejection mechanism comprises a pre-ejection member having a pre-ejection surface and an engaging member having an engaging surface, the pre-ejection member is arranged on the first mold assembly, and the engaging member is configured to transmit force to the main core, and the pre-ejection surface pushes the engaging surface when the mold mechanism is opened.

[0017] Optionally, the first mold assembly and the second mold assembly are each provided with a temperature control system for regulating the temperature of the mold assembly.

[0018] For a large-sized long strip-shaped metal part, the present application realizes small occupied area, improves metal liquid temperature uniformity, effectively reduces turbulent gas entrainment, and other technical problems by reasonably arranging the liquid runner, core, overflow system, and core pulling assembly in the mold mechanism. The structure is compact, the first and second liquid runners are used to communicate the tail and head of the cavity respectively for metal liquid filling, the overflow system is arranged in the system, only one exhaust mechanism is used, which can efficiently exhaust and suppress metal liquid turbulence, the pre-ejection mechanism is used to pre-loosen the metal part at the first time of mold opening, which reduces the adhesion between the main core and the metal part, avoids the use of a large-sized core pulling driving device, facilitates the ejection and subsequent machining of the metal part, and makes the die-casting process smoother, thereby improving the die-casting efficiency. The metal part die-cast by the mold device of the present application has high density, good quality, stable size, high precision, and good surface finish, which meets the application scenarios of high-quality products, especially in the low-altitude economy field such as eVTOL, unmanned aerial vehicles, and other aircraft, which can effectively achieve weight reduction to meet the ultra-lightweight target. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a perspective view of an embodiment of the overall mold device of the present application.

[0020] Figure 2 It is a top view of the mold device structure of an embodiment of the present application with the first mold assembly removed.

[0021] Figure 3 This is a top view of a mold device structure in one embodiment of this application, in which the first mold assembly and the feed cylinder are removed.

[0022] Figure 4 This is a structural diagram of a first mold element according to an embodiment of this application.

[0023] Figure 5 This is a structural diagram of a second mold element according to an embodiment of this application.

[0024] Figure 6 This is a structural diagram of a third mold element according to an embodiment of this application.

[0025] Figure 7 This is a structural diagram of the fourth mold element in an embodiment of this application.

[0026] Figure 8 This is a structural diagram of a metal component according to an embodiment of this application.

[0027] Figure 9 This is another structural diagram of a metal component according to an embodiment of this application.

[0028] Figure 10 This is a structural diagram of the feed cylinder according to an embodiment of this application.

[0029] Figure 11 This is a top view of a mold device structure in one embodiment of this application, in which the first mold assembly, feed cylinder, main core, and metal parts are removed.

[0030] Figure 12 This is a top view of a mold device structure in one embodiment of this application, in which the first mold assembly, the feed cylinder, and the metal parts are removed.

[0031] Figure 13 This is a structural diagram of a pre-top component according to an embodiment of this application.

[0032] Figure 14 This is another structural diagram of a pre-top component according to an embodiment of this application.

[0033] Figure 15 for Figure 3 A magnified view of a portion of point A in the middle.

[0034] Figure 16 This is a structural diagram of the first slag tank according to an embodiment of this application.

[0035] Figure 17 This is another structural diagram of the first slag tank according to an embodiment of this application.

[0036] Figure 18 This is another structural diagram of the first slag tank according to an embodiment of this application. Detailed Implementation

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0039] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0040] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0041] The high-precision magnesium alloy die-casting mold device 100 of this application, such as Figures 1-3 As shown, it includes a mold mechanism 1, a core 2, a core-pulling assembly 3, an overflow system 4, and an ejector pin mechanism 5, for die casting of metal parts 10.

[0042] The mold mechanism 1 has X, Y, and Z axes along the length, width, and thickness directions, respectively, as shown in the figure. It includes a first mold assembly 11 and a second mold assembly 12. The first mold assembly 11 and the second mold assembly 12 are provided with liquid runners 15 and cavities 13 communicating with the liquid runners 15. When the first mold assembly 11 and the second mold assembly 12 are closed, the core 2 is located in the cavity 13, and multiple relief openings 14 are formed on its periphery. The core 2, the core-pulling assembly 3, and the cavity 13 together constitute the shape of the metal part to be die-cast. The core-pulling assembly 3 is correspondingly arranged to the core 2. Specifically, one end of the core-pulling assembly 3 is disposed in the mold mechanism 1 to connect to the core 2 of the mold device 100, and the other end extends out of the mold mechanism 1 from the relief openings 14, so as to facilitate the removal of the core 2 from the mold mechanism 1 when the mold is opened.

[0043] Combined with appendix Figures 4-7 The first mold assembly 11 includes a first mold element 111 and a second mold element 112, and the second mold assembly 12 includes a third mold element 121 and a fourth mold element 122. The first mold element 111, the second mold element 112, the third mold element 121, and the fourth mold element 122 each have a first surface near the fixed end of the die-casting equipment and a second surface away from the fixed end. A first positioning groove 1111 is provided on the second surface of the first mold element 111, and the second mold element 112 is located within the first positioning groove 1111 of the first mold element 111. A second positioning groove 1221 is provided on the first surface of the fourth mold element 122, and the third mold element 121 is located within the second positioning groove 1221 of the fourth mold element 122.

[0044] In one implementation, such as Figures 5-6 As shown, a recess 1123 is provided on the second surface of the second mold element 112, and a boss 1213 adapted to the recess 1123 is provided on the first surface of the third mold element 121. When the mold mechanism 1 closes the mold, the recess 1123 and the boss 1213 lock and position the second mold element 112 and the third mold element 121. Under the action of the clamping force, the second surface of the second mold element 112 and the first surface of the third mold element 121 fit together, preventing the generation of metal flash and burrs. In another embodiment, a boss 1213 is provided on the second surface of the second mold element 112, and a recess 1123 adapted to the boss 1213 is provided on the first surface of the third mold element 121, which can also achieve the locking and positioning of the second mold element 112 and the third mold element 121. Further, in a preferred embodiment, the boss 1213 and the recess 1123 are provided in the peripheral corner area of ​​the second and third mold elements.

[0045] During the die-casting process, the first mold assembly 11 is fixed to the fixed end of the die-casting equipment, and the second mold assembly 12 is fixed to the movable end of the die-casting equipment. The feed cylinder 161 is configured to engage with the die-casting equipment. When the first mold assembly 11 and the second mold assembly 12 are closed, the high pressure of the die-casting equipment pushes the molten metal from the injection chamber into the feed cylinder 161. The feed cylinder 161 guides the molten metal into the first mold assembly 11. The flow divider cone 162 guides and stabilizes the flow of the die-casting molten metal. Then, it enters the liquid runner 15 and is guided into the cavity 13 until the cavity 13 is filled and shaped. Then, the die-casting equipment moves the second mold assembly 12, and then the mold is opened and the part is removed.

[0046] The core-pulling assembly 3 includes a fixing frame 33 connecting the core 2 and a driving device 34 connected to the fixing frame 33. The core-pulling assembly 3 is driven by the driving device 34 to eject the core 2 from the mold cavity. In one embodiment, the driving device 34 is a hydraulic cylinder. Under the drive of high-pressure hydraulic oil, the core-pulling assembly 3 achieves precise linear reciprocating motion, meeting the requirements for driving force, stroke accuracy, and motion stability during the die-casting process. Specifically, after mold closing and forming, the core-pulling assembly 3 drives the core 2 to be pulled out from the mold mechanism 1 in a direction away from the metal part 10, completing the separation of the core 2 from the metal part 10.

[0047] Combined with appendix Figures 8-9 The metal component 10 has an overall elongated shape, with the longest length L1, the widest width W1, the highest height H1, and the thickest wall thickness T1, wherein L1≥2W1, W1≥H1, 60cm≥L1≥43cm, 20cm≥W1≥14cm, 15cm≥H1≥8cm, and 1cm≥T1≥0.2cm. The metal component 10 to be die-cast includes a head 101, a main body 102, and a tail 103. The metal component 10 has a main cavity 104 that penetrates the main body 102 and the tail 103 to accommodate related functional items, such as power batteries and electronic control components with high safety performance requirements, which are not limited here.

[0048] The core 2 includes a main core 21 and a sub-core 22. The main core 21 corresponds to the main cavity 104 of the metal part 10 to be die-cast, and the sub-core 22 corresponds to the sub-cavity of the head 101 and / or tail 103 structure of the metal part, such as the local detailed structure of the head 101 and tail 103, such as blind holes, through slots and other structures.

[0049] Referring to the attached drawings, the mold mechanism 1 also includes a feeding mechanism 16, which is connected to the liquid runner 15. The feeding mechanism 16 includes a feeding cylinder 161 and a flow divider cone 162. The feeding cylinder 161 is made of a material with high temperature resistance, good thermal stability, and erosion resistance, while the flow divider cone 162 is made of a material with thermal erosion resistance, thermal fatigue resistance, and wear resistance. The feeding cylinder 161 is mounted on the first mold assembly 11, and the flow divider cone 162 is mounted on the second mold assembly 12. When the first mold assembly 11 and the second mold assembly 12 are closed, the feeding cylinder 161 can be fitted inside the feeding cylinder 161. The feeding cylinder 161 guides the die-casting molten metal into the first mold assembly 11. With the cooperation of the flow divider cone 162, the molten metal is guided through the liquid runner 15 and enters the cavity 13.

[0050] In one embodiment, the liquid runner 15 includes a first liquid runner 151 and a second liquid runner 152. The first liquid runner 151 is connected to the cavity at the tail of the metal component, and the second liquid runner 152 is connected to the cavity at the head of the metal component. The molten metal transported through the first liquid runner 151 extends and fills from the tail of the metal component towards the head cavity. At the same time, the molten metal transported through the second liquid runner 152 extends and fills from the head cavity of the metal component towards the tail direction. The molten metal transported by the first liquid runner 151 and the second liquid runner 152 converges in the cavity, and finally completes the complete filling of the cavity. Compared with the case of only setting one liquid runner, it is necessary to precisely control the mold temperature to prevent temperature drift caused by long-distance transportation of molten metal, resulting in cold shuts or incomplete filling in the last filled cavity area. In this application, two liquid runners are adopted. On the one hand, it can effectively improve the manufacturing process tolerance and product quality; on the other hand, under the condition of using the same precision to control the mold temperature, the method of setting two liquid runners can shorten the cavity filling distance, effectively control the temperature difference of the molten metal in the cavity, and improve the density of the metal component.

[0051] In one embodiment, as Figures 10-11 shown, the feeding cylinder 161 is cylindrical and is arranged on one side of the cavity 13. The lower bottom of the feeding cylinder 161 is provided with a first discharge hole 1611 and a second discharge hole 1612. Correspondingly, the flow dividing cone 162 is provided with a first flow channel groove 1621 and a second flow channel groove 1622. Among them, the first flow channel groove 1621 and the second flow channel groove 1622 are respectively arranged corresponding to the positions of the first discharge hole 1611 and the second discharge hole 1612, and the first discharge hole 1611 and the first flow channel groove 1621 are connected to the first liquid runner 151, and the second discharge hole 1612 and the second flow channel groove 1622 are connected to the second liquid runner 152. After the molten metal flows out of the first discharge hole 1611, it enters the first liquid runner 151 and is guided by the first liquid runner 151 to the tail cavity 13; after the molten metal flows out of the second discharge hole 1612, it enters the second liquid runner 152 and is guided by the second liquid runner 152 to the head cavity.

[0052] In one embodiment, the cross-section of the feeding cylinder 161 has inner diameters D1 and D2 in sequence along the direction of the molten metal inflow, where D1 > D2. During the die-casting process, the flow channel for the molten metal to travel shrinks, the metal pressure is compensated, and the molten metal steadily enters the liquid runner 15 after passing through the feeding cylinder 161. Further, in a preferred embodiment, 2 / 3D2 < D1 < 2D2, so that the flow rate of the molten metal is effectively maintained. After the molten metal enters the liquid runner 15, it smoothly fills the cavity, reducing the backflow generated during the front-end transportation of the molten metal, making the die-casting process smoother, reducing the defects of the die-cast parts, improving the quality of the die-cast parts, and thus improving the die-casting efficiency.

[0053] In one embodiment, the mold mechanism 1 is placed vertically, i.e., the Y-axis extends vertically. The first and second surfaces of the mold elements are located in corresponding vertical planes, and the feed cylinder 161 is located in the area below the first mold assembly 11. Thus, the feed cylinder 161 is located below the die-casting cavity 13. Compared with gravity casting, the pressure injection of the die-casting machine can reduce the turbulence and uneven temperature of the molten metal caused by gravity during the die-casting process. It can also solve the problems of slow speed in gravity casting and effectively solve the problems of low energy efficiency of molds. Furthermore, in a preferred embodiment, the first discharge port 1611 and the second discharge port 1612 of the feed cylinder 161 are located on the side close to the cavity 13, which facilitates the molten metal to be transported to the tail and head of the cavity through the first liquid runner 151 and the second liquid runner 152 in close proximity, reducing process losses.

[0054] The core-pulling assembly 3 includes a main core-pulling assembly 31 and a sub-core-pulling assembly 32. The main core-pulling assembly 31 is configured to pull the main core 21 out of the mold mechanism 1, specifically, to pull it out of the main cavity 104 of the metal part 10; the sub-core-pulling assembly 32 is configured to pull the sub-core 22 out of the mold mechanism 1, specifically, to pull it out of the sub-cavity of the metal part 10.

[0055] The main core-pulling assembly 31 extends generally along the X-axis, with one end connected to the main core 21 and the other end extending outward from the clearance opening 14 in the width direction of the mold mechanism 1. The main core-pulling assembly 31 also includes a first connecting part 311 and a mounting part 312 disposed on the second mold assembly 12. One end of the first connecting part 311 is connected to the main core 21, and the other end is connected to the mounting part 312. The other end of the mounting part 312 is connected to the fixing frame 33 of the main core-pulling assembly 31. After the molten metal is injected into the mold mechanism 1 and formed, the main core 21 can be withdrawn from the cavity 13 of the mold mechanism 1 along the X-axis through the main core-pulling assembly 31.

[0056] In some embodiments of this application, the head 101 of the metal component 10 further includes a first through groove 1011 for connecting with other components to form a structural component with a specific function, the specific function of which is not limited here. The sub-core 22 includes a first sub-core 221 and a second sub-core 222 adapted to the first through groove 1011 of the head, that is, the first sub-core 221 and the second sub-core 222 are generally arranged along the Y-axis direction, i.e., the width direction of the mold mechanism 1. The first sub-core 221 is disposed on one side of the feed cylinder 16. The sub-core pulling assembly 32 includes a first sub-core pulling assembly 321 and a second sub-core pulling assembly 322. The first sub-core pulling assembly 321 and the second sub-core pulling assembly 322 are respectively disposed corresponding to the first sub-core 221 and the second sub-core 222. One end of the first sub-core pulling assembly 321 and the second sub-core pulling assembly 322 are respectively connected to the first sub-core 221 and the second sub-core 222. Inside the mold mechanism 1, the other end extends out from the relief opening 14 along the X-axis direction of the mold mechanism 1, which facilitates the removal of the first sub-core 221 and the second sub-core 222 respectively. That is, the first sub-core pulling assembly 321 and the second sub-core pulling assembly 322 are respectively located on both sides of the width direction of the mold mechanism 1. With this arrangement, the first sub-core 221 and the second sub-core 222 are removed from both sides. On the one hand, this reduces the force when removing the sub-core 22, making it easier to remove the sub-core 22 from the first through groove 1011. On the other hand, it makes the force on the newly formed metal part 10 more uniform when the first sub-core 221 and the second sub-core 222 are removed, making it less likely to damage the metal part 10 and improving the quality of the die-cast product.

[0057] In some embodiments of this application, the tail portion 103 of the metal component 10 further includes an inclined connecting portion 1031 that engages with other components. The inclined connecting portion 1031 and other components form a structural component with a specific function, for example, through a pin connection or hinge connection; the specific connection method is not limited here. Specifically, the sub-core 22 includes a third sub-core (not shown) located at the inclined connecting portion 1031. The third sub-core is configured to form a connecting groove at the inclined connecting portion 1031 for easy connection with structural components of a specific function. A third sub-core pulling assembly 323 is also provided corresponding to the third sub-core. When the mold is closed, the third sub-core pulling assembly 323 is located at the clearance opening 14 along the X-axis of the mold mechanism 1 to facilitate the removal of the third sub-core after die casting, thus achieving integral die casting of the connecting groove of the inclined connecting portion 1031 with the body of the metal component 10. Thus, on the one hand, the introduction of the third sub-core can avoid the problem of air holes easily generated by the material thickness of the inclined connection part 1031 during the die casting process. On the other hand, it also reduces the accuracy and strength problems caused by the repositioning of subsequent local detail processing of metal parts and complex processing procedures. This not only reduces material waste, but also improves the connection strength of metal parts 10 and simplifies the processing procedure.

[0058] Furthermore, in a preferred embodiment, the third sub-core pulling assembly 323 is inclinedly disposed on the mold mechanism 1 according to the inclined connecting portion 1031 and extends along the side away from the center of the mold mechanism 1. This arrangement expands the operating space around the mold mechanism 1, that is, the venting mechanism has more space to operate, and at the same time realizes the local pre-loosening of the formed metal part 10, further reducing defects such as surface damage after demolding and improving the die casting accuracy.

[0059] Combined with appendix Figures 12-14 The mold device 100 also includes a pre-ejection mechanism 6, which is configured to act on the metal part 10 when the mold is opened, so as to pre-separate it from the main core 21, thereby reducing the force required for the main core-pulling assembly 31 to pull out the main core 21. On the one hand, it can avoid the large force, which requires a high output torque for its drive device 34, i.e., a larger model of hydraulic cylinder, which occupies more space; on the other hand, a large force can also easily damage the formed metal part 10 during core pulling, affecting the product yield.

[0060] Specifically, in one embodiment, the pre-ejection mechanism 6 includes a pre-ejection member 61 with a pre-ejection surface 611 and a coupling member 313 with a mating surface (not shown). The pre-ejection member 61 is disposed on the first mold assembly 11, and the coupling member 313 is configured to transmit force to the main body core 21. When the mold mechanism 1 opens the mold, the pre-ejection surface 611 of the pre-ejection member 61 pushes the mating surface of the coupling member 313, thereby generating a force on the main body core 21, thereby causing the main body core 21 to be pre-separated from the metal part 10 to maintain a better surface finish of the product.

[0061] In one specific embodiment, the coupling member 313 is disposed on the main core-pulling assembly 31, the pre-ejection surface 611 is an inclined surface, and the mating surface is an inclined surface adapted to the shape of the pre-ejection surface 611. When the mold mechanism 1 opens, the pre-ejection member 61 moves with the first mold assembly 11, and the pre-ejection surface 611 acts on the mating surface of the main core-pulling assembly 31, applying a moving force to the main core-pulling assembly 31, causing the main core-pulling assembly 31 to move against the main core 21, thereby causing the main core 21 to pre-separate from the metal part 10. Moreover, since the pre-ejection member 61 pre-ejects the main core 21 at the first moment of mold opening when the metal part 10 is just formed, the main core 21 is easier to pull away from the metal part, reducing the adhesion between the main core 21 and the metal part 10. With the pre-ejection mechanism 6 performing pre-separation during mold opening, the subsequent removal of the main core 21 by the main core-pulling assembly 31 can significantly reduce damage and surface defects to the metal part 10, improving product yield and production efficiency.

[0062] Furthermore, in a preferred embodiment, in conjunction with the appendix Figures 13-14The pre-ejector 61 includes a base 612 and a second connecting part 613. The pre-ejector surface 611 is disposed on the base 612. The second connecting part 613 is detachably fixedly connected to the first mold element 111. There are two pre-ejectors 61. Correspondingly, there are also two connecting parts 313 respectively. The connecting parts 313 are integrally disposed on both sides of the mounting part 312 of the main core pulling assembly 31. The pre-ejector 61 is fixed to the first mold element 111 through the second connecting part 613. When the mold is closed, the two pre-ejector 61 enter the connecting part 313 of the main core pulling assembly mounting part 312 along with the first mold element 111. When the mold mechanism 1 is formed and the mold is opened, the two pre-ejector 61 move with the first mold element 111. The pre-ejector surface 611 provides force to both sides of the main core pulling assembly 31 in the direction away from the core 2 by acting with the corresponding connecting surface. The force is balanced and the force transmission is efficient, and the pre-ejection effect is better. It realizes the pre-separation of the main core 21, effectively protects the metal parts 10, and the pre-separation effect is better. In addition, when the pre-ejector 6 is worn or otherwise damaged after a period of use, it can be replaced, which is simple and convenient and also reduces the manufacturing cost.

[0063] Furthermore, in one embodiment, the pre-top surface 611 has an angle α with the vertical direction, wherein the angle α is set to: 5°≤α≤30°. The pre-top member 61 can easily slide and engage with the connecting member while also pre-topping and moving the core 2 a certain distance, thereby facilitating the subsequent removal of the core 2. Furthermore, in one embodiment, the angle α is: 8°≤α≤22°. In this way, the pre-top member 61 can provide a better pre-topping loosening effect, and the appropriate force can avoid damaging the newly formed metal part 10. Furthermore, in a preferred embodiment, the tilt angle of the pre-top surface 611 is set to 9°≤α≤16°. The pre-top member 61 can provide an excellent pre-topping loosening effect and can well preserve the smooth shape of the metal part 10.

[0064] Furthermore, in conjunction with the appendix Figures 12-15 The overflow system 4 includes an overflow trough 42 and an exhaust channel 41. The overflow trough 42 includes a slag-filled trough 421 and an overflow sub-trough 422, which are respectively located on both sides of the core 2. The slag-filled trough 421 is used to collect the molten metal containing gas and the slag formed by the oxidation of the molten metal, and can also guide the gas out of the cavity 13. The overflow trough 42 is connected to the cavity 13, and the exhaust channel 41 is connected to the slag-filled trough 421.

[0065] In one embodiment, the overflow system 4 further includes an exhaust mechanism 43, which is located at the relief opening 14 and communicates with the exhaust channel 41. Specifically, the slag trap 421 and the exhaust mechanism 43 are located on the same side of the core 2. The exhaust mechanism 43 is configured to guide and discharge the gas from the exhaust channel 41, which provides a discharge channel for the gas within the mold mechanism 1. When molten metal is injected into the cavity 13, under the action of the exhaust mechanism, the exhaust channel 41 guides the gas out of the cavity 13 in an orderly manner, reducing gas retention in the cavity 13 and preventing adverse effects such as air entrapment and collapse shrinkage on the quality of the metal component 10, thus ensuring the compactness of the metal component 10.

[0066] In a preferred embodiment, the venting mechanism 43 and the feed cylinder 161 are respectively disposed on both sides of the core 2, with the venting mechanism 43 located on the tail side near the middle region of the main core. The overflow sub-groove 422 and the feed cylinder 161 are disposed on the same side of the core 2, and the slag trap 421 occupies a larger area of ​​the third mold element than the overflow sub-groove 422. When the molten metal is introduced into the first liquid runner 151 and the second liquid runner 152 through the first discharge hole 1611 and the second discharge hole 1612 of the feed cylinder 161, and then enters the tail and head of the cavity of the mold mechanism 1, the gas in the liquid runner 15 and the cavity 13 is pushed out. The molten metal gradually fills the cavity 13 upward under the combined action of pressure and gravity, and the gas moves upward. At the same time, the venting mechanism 43 guides the gas to the venting mechanism 43 side through the venting channel 41. Specifically, the molten metal first enters the cavity section near the feed cylinder. The gas in the cavity near the feed cylinder is propelled by the molten metal to the overflow system, and with the help of the venting mechanism, the gas is guided to the venting channel of the overflow system. Since the venting mechanism is located on one side of the mold mechanism 1 and there is only one venting mechanism, compared to having multiple venting mechanisms on multiple sides, the gas in this application is guided in an orderly manner in one direction, effectively avoiding problems such as turbulence and oxidation caused by multi-directional gas flow. At the same time, it also provides sufficient operating space for the second sub-core pulling assembly 322, facilitating the installation or removal of the second sub-core pulling assembly 322. Overall, the spatial layout of the mold mechanism 1 for large-sized metal parts is optimized, ensuring the quality of die-cast products while reducing the area of ​​the mold mechanism 1.

[0067] In one embodiment, the slag packing groove 421 located in the corresponding area of ​​the main core 21 is defined as the first slag packing groove 4210. The first slag packing groove 4210 is arranged linearly, which facilitates design and manufacturing while enabling precise coordination with the exhaust mechanism to achieve orderly airflow guidance and guide deep exhaust and slag discharge.

[0068] In one embodiment, the first discharge hole 1611 and the second discharge hole 1612 of the feed cylinder have the same height, and the arc lengths of the first discharge hole 1611 and the second discharge hole 1612 are R1 and R2, respectively, wherein 2 / 3 ≤ R2 / R1 ≤ 6 / 7. Under the directional exhaust guidance of the overflow system 4, turbulent air entrapment can be effectively suppressed. Compared with the case where the flow rates of the two liquid metals are the same, it can effectively reduce the strong turbulent air entrapment generated by the merging, while maintaining the rapid filling of the two liquids, reducing the temperature difference, and improving the product density. Further, in a preferred embodiment, 4 / 5 ≤ R2 / R1 ≤ 5 / 6. Under the effective exhaust guidance of the overflow system 4, the filling of the liquid metal can be made more stable, preventing oxidation and loosening, and improving the product density and surface finish.

[0069] Further, in one embodiment, the end where the main core 21 connects to the main core-pulling assembly 31 is defined as the main core end. The first liquid runner 151 includes an extended liquid runner 1511, which is offset at the main core end near the main core-pulling assembly. The direction of the extended liquid runner 1511 is adapted to the shape of the main core end, that is, the projection of the extended liquid runner 1511 and the main core end onto the second surface of the second mold element is approximately parallel. After flowing out from the first outlet hole 1611 of the feed cylinder 161, the molten metal eventually fills the tail cavity through the extended liquid runner 1511. The molten metal flows towards the main core end and merges with the molten metal in the second liquid runner 152 under the directional guidance of the overflow system 4. With this configuration, the molten metal can better adapt to the shape of the metal part and enter the cavity, effectively protecting the main core 21, making the filling more stable, and maintaining the accuracy of the metal part. Compared to the case where the material is directly connected to the cavity area on the side of the feed cylinder, the lateral erosion of the main core 21 by the high-pressure molten metal causes turbulent air entrainment and damages the main core, affecting the precision of the metal parts and increasing manufacturing costs.

[0070] In one embodiment, the end of the first sub-core 221 connected to the first sub-core pulling assembly 321 is the first sub-core end, and the head cavity area corresponding to the first sub-core end is the first head cavity end; the end of the second sub-core 222 connected to the second sub-core pulling assembly 322 is the second sub-core end, and the head cavity area corresponding to the second sub-core end is the second head cavity end. The second liquid gating channel 152 is connected to the first head cavity end, that is, the molten metal through the second liquid gating channel 152 enters the filling through the first head cavity end. In this way, the molten metal connection path can not only fill the head cavity according to its shape, but also effectively guide the gas in the head cavity to the exhaust mechanism side, reduce turbulent air entrapment, and improve product density.

[0071] In one embodiment, the second liquid runner 152 further includes a liquid sub-runner 1521, which connects to the cavity region near the head. The cross-sectional area of ​​the liquid sub-runner 1521 is less than half the total cross-sectional area of ​​the second liquid runner 152. This arrangement further enhances the power of the molten metal filling the end of the second head cavity, resulting in better overall cavity filling. Due to the introduction of the liquid sub-runner 1521, the molten metal flowing through it allows other molten metal from the second liquid runner 152 to better extend and fill the end of the second head cavity, thus orderly and completely filling the head cavity and reducing backflow and air entrapment within the cavity. Furthermore, in a preferred embodiment, the second liquid runner 152 includes two parallel liquid sub-runners 1521, which is simple to manufacture and allows for better zoned guidance, effectively controlling turbulence while smoothly and efficiently filling the head cavity completely.

[0072] In one embodiment, the slag packing groove 421 includes multiple grooves, wherein the exhaust channel where the slag packing groove 421 near the tail 103 region is gathered is the first exhaust channel 411, and the exhaust channel where the slag packing groove 421 near the head 101 region is gathered is the second exhaust channel 412. The two exhaust channels converge into the exhaust mechanism 43. In this way, the gas during filling of the mold cavity by the first liquid gating channel 151 and the second liquid gating channel 152 can be more effectively diverted to achieve zoned exhaust guidance, optimize the airflow guidance, orderly discharge from the mold cavity, reduce gas turbulence and entrapment, and further improve the density of the metal parts.

[0073] In one embodiment, the first exhaust channel 411 includes a first main exhaust channel 4111 and a first branch exhaust channel 4112; the second exhaust channel 412 includes a second main exhaust channel 4121 and a second branch exhaust channel 4122. The first branch exhaust channel 4112 connects to the corresponding slag trough 421 and flows into the first main exhaust channel 4111; the second branch exhaust channel 4122 connects to the corresponding slag trough 421 and flows into the second main exhaust channel 4121. The second branch exhaust channel 4122 flows into the second main exhaust channel 4121 in a direction inclined away from the slag trough 421 towards the exhaust mechanism 43. This allows for more effective guidance of the gas propelled by the molten metal through the second liquid gating channel 152 into the exhaust mechanism, reducing turbulent gas entrapment and improving product density.

[0074] Specifically, in one embodiment, six slag-filling grooves 421 are provided, of which three slag-filling grooves 421 near the tail 103 converge to form a first exhaust channel 411, and three slag-filling grooves 421 near the head 101 converge to form a second exhaust channel 412, so as to complete the gas directional guidance required for the two liquid filling cavities, effectively avoid oxidation and loosening caused by turbulence, and improve the density and smoothness of the product.

[0075] Furthermore, in a preferred embodiment, in conjunction with the appendixFigures 15-18 The first slag bag groove 4210 includes a diversion groove 4211 and a slag bag main groove 4212. One end of the diversion groove 4211 is connected to the cavity 13, and the other end is connected to the slag bag main groove 4212. The diversion groove 4211 has a maximum length of L3, a maximum width of W3, and a maximum depth of H3. The slag bag main groove 4212 has a maximum length of L4, a maximum width of W4, and a maximum depth of H4. The cross-sectional area of ​​the diversion groove 4211 is smaller than that of the slag bag main groove 4212. Further, in one embodiment, the depth of the diversion groove 4211 gradually increases with distance from the cavity 13, while the length and width of the slag bag main groove 4212 gradually decrease from the central region to the peripheral region. This effectively collects the molten metal containing gas and the oxidized slag, and also effectively guides the airflow to the exhaust channel 41, thus effectively discharging the gas from the mold mechanism 1.

[0076] In one embodiment, the depth of the drainage groove 4211 gradually increases as it moves away from the core. The size relationship between the slag bag main groove 4212 and the drainage groove 4211 is 1 / 2L4≤L3≤2 / 3L4, H3>H4. This maintains good rigidity and strength, facilitates subsequent demolding, and makes it easier to remove the first slag bag groove 4210 connected to the metal part 10 after die casting, thus facilitating efficient processing.

[0077] The mold assembly 100 also includes an ejector mechanism 5 disposed on the side of the second mold assembly 12 away from the direction of the first mold assembly 11. The ejector mechanism 5 includes an ejector support 51 and a plurality of ejector pins. The ejector mechanism 5 is movably engaged with the second mold assembly 12 for ejecting the metal part 10 out of the second mold assembly 12. Specifically, the plurality of ejector pins are configured to move toward the first mold assembly 11 after the mold is opened, push the metal part 10 forward and eject it, so that a worker or robot can grab the metal part 10 and remove it from the mold, completing one die-casting process.

[0078] The ejector pin is made of a metal or alloy with high hardness, good wear resistance, and resistance to bending fatigue. For example, steel or other hard alloys can be used. The cross-section of the ejector pin can be circular or rectangular. The regular cross-sectional shape facilitates design and manufacturing, and makes it easy to control the ejection accuracy. The ejector pin only needs to meet the mechanical performance requirements, and no special restrictions are imposed here.

[0079] Multiple ejector pins are distributed on both sides of the metal part 10 to be die-cast, and are arranged at the overflow groove 42, the liquid runner 15, and the slag trough 421. On the one hand, they evenly separate the metal part 10 from the second mold assembly 12, pushing the metal part 10 to demold. On the other hand, they avoid stress damage caused by the ejector pins being located on the metal part 10, reducing defects such as scratches, cracks, and dents in the die-cast metal part 10. In one embodiment, the ejector pins are preferably located at the slag trough of the slag trough 421, because they are far from the cavity 13 and have a large thickness, which can withstand a large demolding force while not easily damaging the metal part 10, facilitating demolding.

[0080] In one embodiment, both the first mold assembly 11 and the second mold assembly 12 are equipped with a temperature control system 7, which is used to regulate the temperature of the mold assemblies. Before die casting begins, the temperature control system 7 can preheat the mold assemblies. When the temperature of the mold assembly is lower than a set threshold, the temperature control system 7 is activated to heat the mold assembly, and when the temperature of the mold assembly is higher than the set threshold, the temperature control system 7 is activated to cool it down, so as to increase the flow rate of molten metal in the mold mechanism 1 and ensure that the temperature of the mold assembly is within the set range. After the molten metal is injected into the mold cavity 13, the temperature control system 7 is configured to cool the first mold assembly 11 and the second mold assembly 12, thereby effectively cooling and solidifying the metal parts inside the molding cavity, avoiding excessively high temperatures that could prolong the production cycle and cause shrinkage cavities, porosity, and other phenomena.

[0081] For die casting of large-sized metal parts, especially those with long, narrow shapes, the mold device 100 of this application features a novel layout design. The liquid runner, core 2, overflow system 4, and core-pulling assembly 3 within the mold mechanism 1 are rationally arranged and compactly structured, enabling small mold size, small footprint, and easy demolding. By using the first liquid runner 151 and the second liquid runner 152 to connect the tail and head of the cavity respectively for molten metal filling, and the overflow system 4 is systematically arranged, the uniformity of molten metal temperature is effectively improved while avoiding technical problems such as turbulence and air entrapment. This improves the density and surface finish of magnesium alloy die-cast metal parts, resulting in a smooth die-casting process and high efficiency. It not only meets the production requirements of conventional transportation vehicle parts but is also suitable for technical application scenarios with higher product quality requirements, especially in the low-altitude economic field, such as eVTOL and drones. It meets airworthiness certification while effectively reducing weight and achieving ultra-lightweight goals.

[0082] 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 high-precision magnesium alloy die-casting mold device, comprising: The mold mechanism has X, Y, and Z axes along its length, width, and thickness directions, and includes first and second mold assemblies and a feeding mechanism. The first and second mold assemblies have multiple clearance ports on their periphery. The first and second mold assemblies have liquid runners and cavities inside. One end of the liquid runner connects to the feeding mechanism, and the other end connects to the cavity. The feeding mechanism includes a feeding cylinder and a flow divider cone. A core is located within the cavity when the first and second mold assemblies are closed. A core-pulling assembly includes a fixing frame connecting the core and a driving device connected to the fixing frame. The core-pulling assembly is correspondingly positioned to the core. The metal part to be die-cast includes a head, a main body, and a tail, and the metal part also has a main cavity penetrating the main body and tail. The metal part is elongated. An overflow system includes an overflow trough, an exhaust channel, and an exhaust mechanism. The overflow trough communicates with the cavity and includes a slag-filled trough and an overflow sub-trough, which are respectively located on both sides of the core. The exhaust channel communicates with the slag-filled trough, and the exhaust mechanism is located at the clearance port and communicates with the exhaust channel. The feature is that the liquid runner includes a first liquid runner and a second liquid runner, wherein the first liquid runner connects to the tail cavity of the metal component, and the second liquid runner connects to the head cavity of the metal component; the core includes a main core and a sub-core, the main core corresponding to the main cavity of the metal component, and the sub-core corresponding to the sub-cavity of the head and / or tail structure of the metal component; the core pulling assembly includes a main core pulling assembly and a sub-core pulling assembly, the main core pulling assembly corresponding to the main core, and the sub-core pulling assembly corresponding to the sub-core; the end of the main core connected to the main core pulling assembly is defined as the end of the main core, the first liquid runner includes an extended liquid runner, the extended liquid runner is offset on the end of the main core near the main core pulling assembly, and the direction of the extended liquid runner is adapted to the shape of the end of the main core; the head of the metal component also includes a first through groove, and the sub-core includes a first sub-core and a second sub-core adapted to the first through groove of the head, the first sub-core and the second sub-core are arranged along the Y-axis direction, wherein the first sub-core... The core is located on one side of the feed cylinder. The sub-core pulling assembly includes a first sub-core pulling assembly and a second sub-core pulling assembly, which are respectively set for the first and second sub-cores. The end of the first sub-core connected to the first sub-core pulling assembly is the end of the first sub-core, and the head cavity area corresponding to the end of the first sub-core is the end of the first head cavity. The second liquid runner is connected to the end of the first head cavity. The feed cylinder is located on one side of the cavity. The bottom of the feed cylinder is provided with a first discharge hole and a second discharge hole. The flow divider cone is provided with a first flow channel groove and a second flow channel groove. The first and second flow channel grooves are respectively set to correspond to the positions of the first and second discharge holes. The first discharge hole and the first flow channel groove are connected to the first liquid runner, and the second discharge hole and the second flow channel groove are connected to the second liquid runner. The first discharge hole and the second discharge hole of the feed cylinder are at the same height. The arc lengths of the first discharge hole and the second discharge hole are R1 and R2, respectively, where 2 / 3≤R2 / R1≤6 / 7.

2. The high-precision magnesium alloy die-casting mold device according to claim 1, characterized in that: The exhaust mechanism and the feed cylinder are respectively located on both sides of the core, and the overflow sub-groove and the feed cylinder are located on the same side of the core. There are multiple slag packing grooves, among which the slag packing grooves near the tail area converge to form the first exhaust channel, and the slag packing grooves near the head area converge to form the second exhaust channel. The first and second exhaust channels converge into the exhaust mechanism.

3. The high-precision magnesium alloy die-casting mold device according to claim 1, characterized in that: The mold assembly also includes a pre-ejection mechanism, which is configured to act on the die-cast metal parts when the mold is opened, so as to pre-separate them from the core.

4. The high-precision magnesium alloy die-casting mold device according to claim 3, characterized in that: The pre-ejection mechanism includes a pre-ejector with a pre-ejection surface and a joint with a joint surface. The pre-ejector is disposed on the first mold assembly, and the joint is configured to transmit force to the main core. The pre-ejection surface pushes the joint surface when the mold mechanism opens.

5. The high-precision magnesium alloy die-casting mold device according to claim 1, characterized in that: Both the first mold assembly and the second mold assembly are equipped with a temperature control system, which is used to regulate the temperature of the mold assembly.

Images