MAGNESIUM-ALUMINUM DUAL-INJECTION DIE-CASTING MACHINE AND MAGNESIUM-ALUMINUM DUAL-INJECTION SYSTEM

CROSS REFERENCE TO THE RELATED APPLICATIONS

[0001]This application is based upon and claims priority to Chinese Patent Application No. 202510060428.3, filed on Jan. 15, 2025, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

[0002]The present disclosure relates to the technical field of die-casting machines, and in particular to a magnesium-aluminum dual-injection die-casting machine, and a magnesium-aluminum dual-injection system.

BACKGROUND

[0003]Die-casting machines are configured for pressure casting, and include hot-chamber die-casting machines and cold-chamber die-casting machines. The cold-chamber die-casting machines are further divided into vertical cold-chamber die-casting machines and horizontal cold-chamber die-casting machines. Under a pressure, a die-casting machine injects a molten metal stream into a die for cooling and forming, and a solid metal casting is obtained after die opening. Such machines were initially configured for type casting.

[0004]In the die-casting process, different products are made of different materials. For example, there are aluminum-alloy die-casting and magnesium-alloy die-casting. For aluminum alloys, the molten metal stream for die-casting is in a pure liquid state, while for magnesium alloys, the molten metal stream for die-casting is in a solid-liquid mixed state. Therefore, two separate die-casting machines are required for these two materials, leading to increased equipment costs and larger floor space. To solve this technical problem, a magnesium-aluminum dual-injection die-casting machine is proposed.

SUMMARY

[0005]An objective of the present disclosure is to provide a magnesium-aluminum dual-injection die-casting machine.

[0006]Another objective of the present disclosure is to provide a magnesium-aluminum dual-injection system.

[0007]To achieve the above objectives, the present disclosure adopts the following technical solutions. A magnesium-aluminum dual-injection die-casting machine is provided, including a die-casting machine body, an injection module, and a melting module, where the injection module is disposed on a side of the die-casting machine body and the injection module is disposed parallel to the die-casting machine body; the melting module is cooperatively connected to the injection module, and the melting module is disposed perpendicular to the die-casting machine body; during first-mode die-casting, the injection module is configured to inject an added first-form molten metal stream into the die-casting machine body for forming; and during second-mode die-casting, the melting module is configured to first inject a second-form molten metal stream into the injection module, and the injection module is configured to subsequently inject the second-form molten metal stream into the die-casting machine body for forming.

[0008]Preferably, the die-casting machine body is provided with a thrust mechanism; the thrust mechanism is in cooperation with the injection module, and the thrust mechanism corresponds to and is disposed parallel to the melting module; and the thrust mechanism is configured to drive the injection module and the melting module to press against and cooperate with each other, such that the injection module and the melting module maintain a sealed state.

[0009]Preferably, limit rods are disposed with vertical symmetry and penetrate through a fixed platen of the die-casting machine body; the melting module is in cooperation with first ends of the limit rods, to secure the melting module; and the thrust mechanism is secured through second ends of the limit rods.

[0010]Preferably, the injection module includes an injection barrel, an extrusion barrel, and an injection nozzle, the injection barrel is disposed on the fixed platen of the die-casting machine body; the extrusion barrel and the injection nozzle are sequentially arranged in communication with an end of the injection barrel; the injection nozzle is in cooperation with a cavity of the die-casting machine body; and the extrusion barrel is cooperatively communicated with the melting module.

[0011]Preferably, the thrust mechanism includes a thrust cylinder and a push head; the thrust cylinder is disposed on the fixed platen; the push head is disposed at one end of a piston rod; and the thrust cylinder is configured to drive the push head to press against and act on the extrusion barrel, to allow the extrusion barrel and an injection head of the melting module to press against and seal with each other.

[0012]Preferably, an inner diameter of the injection head is smaller than an inner diameter of the extrusion barrel; and an inner diameter of the injection nozzle is smaller than a diameter of a gate of the cavity.

[0013]A magnesium-aluminum dual-injection system employing the above magnesium-aluminum dual-injection die-casting machine is provided, where the magnesium-aluminum dual-injection system is configured to perform first-mode die-casting according to following steps: slow injection, fast injection, and boost injection; and perform second-mode die-casting according to following steps: fast injection and boost injection.

[0014]Preferably, the magnesium-aluminum dual-injection system includes an accumulator, an injection cylinder, a booster cylinder, and a valve module connected through oil lines; the valve module includes a switching valve V5, a switching valve V8, a servo valve V9, a one-way valve V11, and a one-way valve V13; an output end of an oil pump is connected to a rod chamber of the injection cylinder to form a first oil line through the one-way valve V11 and the servo valve V9 that are sequentially connected; the output end of the oil pump is connected to a rodless chamber of the injection cylinder to form a second oil line through the one-way valve V11, the one-way valve V13, the switching valve V8, and the switching valve V5 that are sequentially connected; and when the oil pump supplies oil alone during the slow injection, the oil pump supplies the oil to the rodless chamber of the injection cylinder through the second oil line in communication, and the first oil line and the second oil line form a differential circuit.

[0015]Preferably, the valve module further includes a servo valve V7; an oil tank is connected to the rod chamber of the injection cylinder to form a third oil line through the servo valve V7; during the fast injection and a braking, the accumulator supplies oil to the rodless chamber of the injection cylinder through a switching valve V4 and the switching valve V5; pressure oil in the rod chamber of the injection cylinder flows back to the oil tank via the servo valve V7; and the first oil line and the third oil line are communicated to form a first A-type half-bridge, and an injection speed of the injection cylinder is adjusted by controlling an opening of the servo valve V7 and an opening of the servo valve V9.

[0016]Preferably, the valve module further includes a switching valve V6; the accumulator is connected to a rodless chamber of the booster cylinder to form a fourth oil line through the switching valve V4; the oil tank is connected to a rod chamber of the booster cylinder to form a fifth oil line through the servo valve V7 and the switching valve V6 that are sequentially connected; the output end of the oil pump is connected to the rod chamber of the booster cylinder to form a sixth oil line through the one-way valve V11, the servo valve V9, and the switching valve V6 that are sequentially connected; during the boost injection, the accumulator supplies oil to the rodless chamber of the booster cylinder through the fourth oil line in communication; pressure oil in the rod chamber of the booster cylinder and the pressure oil in the rod chamber of the injection cylinder respectively flow back to the oil tank through the fifth oil line in communication and the servo valve V7; and the sixth oil line and the fifth oil line are communicated to form a second A-type half-bridge, and a boost pressure of the booster cylinder is adjusted by controlling the opening of the servo valve V9 and the opening of the servo valve V7.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is a schematic overall structural diagram according to the present disclosure.

[0021]FIG. 2 is a schematic partial structural diagram according to the present disclosure.

[0022]FIG. 3 is a schematic cross-sectional structural diagram based on FIG. 2 according to the present disclosure.

[0023]FIG. 4 is a schematic enlarged structural diagram of part A according to the present disclosure.

[0024]FIG. 5A and FIG. 5B show schematic structural diagrams of an assembly of a melting module, an injection module, and a thrust mechanism according to the present disclosure.

[0025]FIG. 6 is a schematic overall structural diagram of the melting module according to the present disclosure.

[0026]FIG. 7 is a schematic specific structural diagram of the melting module according to the present disclosure.

[0027]FIG. 8 is a schematic diagram for magnesium particle injection and conveying according to the present disclosure.

[0028]FIG. 9 is a schematic diagram for injection after magnesium particle melting according to the present disclosure.

[0029]FIG. 10 is a schematic structural diagram of a screw according to the present disclosure.

[0030]FIG. 11A and FIG. 11B show schematic diagrams of the flow of a magnesium material through a screw head and its backflow according to the present disclosure.

[0031]FIG. 12 is a specific schematic structural diagram of the screw head according to the present disclosure.

[0032]FIG. 13 is a schematic diagram of a die bridge assembly according to the present disclosure.

[0033]FIG. 14 is a schematic diagram showing a state when a molten metal stream for die-casting is located in an injection barrel.

[0034]FIG. 15 is a schematic diagram showing a working principle of slow injection according to the present disclosure.

[0035]FIG. 16 is a schematic diagram showing a working principle of fast injection according to the present disclosure.

[0036]FIG. 17 is a schematic diagram showing a working principle of boost injection according to the present disclosure.

[0037]Reference Numerals: 1. die-casting machine body; 2. fixed platen; 3. injection module; 301. injection barrel; 302. extrusion barrel; 303. injection nozzle; 4. melting module; 401. melting barrel; 402. conveying mechanism; 4021. mounting block; 4022. screw; 4023. driving device; 403. injection assembly; 4031. injection seat; 4032. injection shifting cylinder; 5. thrust mechanism; 501. thrust cylinder; 502. push head; 6. injection head; 7. limit rod; 8. feed port; 9. screw head; 901. rod head portion; 902. blocking portion; 903. gasket; 904. non-return ring; 905. sleeve ring; 10. material groove; 11. flow channel; 12. gap; 13. die bridge assembly; 14. die bridge; 15. tray cylinder; 16. injection platen; 17. booster cylinder; 18. accumulator; and 19. injection cylinder.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038]The present disclosure will be further described below with reference to the drawings and specific embodiments. It should be noted that, provided that there is no conflict, new embodiments can be formed by arbitrarily combining various embodiments or various technical features described below.

[0039]In the description of the present disclosure, it should be noted that the orientation or position relationships indicated by nouns of locality such as the terms “center”, “transverse”, “longitudinal”, “length”, “width”, “thickness”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer”, “clockwise”, and “counterclockwise” are based on those shown in the drawings. It is only for the convenience of describing the present disclosure and simplifying the description, and does not indicate or imply that the referred apparatus or element must have a specific orientation and be constructed and operated in a specific orientation. Therefore, it cannot be understood as limiting the specific protection scope of the present disclosure.

[0040]It should be noted that the terms such as “first” and “second” in the description and claims of the present disclosure are intended to distinguish similar objects but do not necessarily indicate a specific order or sequence.

[0041]A preferred embodiment of the present disclosure provides a magnesium-aluminum dual-injection die-casting machine, as shown in FIG. 1 to FIG. 17. The magnesium-aluminum dual-injection die-casting machine includes a die-casting machine body 1, an injection module 3, and a melting module 4. The injection module 3 is located on a side of the die-casting machine body 1 and is disposed parallel to the die-casting machine body 1. The melting module 4 is cooperatively connected to the injection module 3 and is disposed perpendicular to the die-casting machine body 1.

[0042]It is understandable that the die-casting machine has two die-casting modes during use. In a first die-casting mode, the injection module 3 injects an added first-form molten metal stream into the die-casting machine body 1 for forming. In a second die-casting mode, the melting module 4 first injects a second-form molten metal stream into the injection module 3. Then the injection module 3 injects the second-form molten metal stream into the die-casting machine body 1 for forming. This enables the use of two different forms of molten metal streams on the same die-casting machine, and eliminates the need for two separate die-casting machines, saving equipment costs and space.

[0043]Specifically, in the present disclosure, there are two modes: aluminum alloy die-casting and magnesium alloy die-casting. In first-mode (aluminum alloy) die-casting, since aluminum alloy has a high melting point, only a cold-chamber die-casting machine, rather than a hot-chamber die-casting machine, can be used for production. That is, aluminum alloy metal is melted outside the die-casting machine. The first-form molten metal stream (i.e., molten aluminum) is added to the injection module 3, and the first-form molten metal stream is injected into the die-casting machine through the injection module 3. In second-mode (magnesium alloy) die-casting, the second-form molten metal stream (i.e., molten magnesium) is first added to the injection module 3 through the melting module 4. Then the second-form molten metal stream is injected into the die-casting machine through the injection module 3. That is, the two forms of molten metal streams share the injection module 3 during die-casting, which flexibly achieves two different die-casting modes.

[0044]In a further description of the above embodiment, as shown in FIG. 4, the injection module 3 includes an injection barrel 301, an extrusion barrel 302, and an injection nozzle 303. The injection barrel 301 is disposed on a fixed platen 2 of the die-casting machine body 1. An end of the injection barrel 301 is sequentially communicated with the extrusion barrel 302 and the injection nozzle 303. The injection nozzle 303 is in cooperation with a cavity of the die-casting machine body 1. The extrusion barrel 302 is cooperatively communicated with the melting module 4. It is understandable that the melting module 4 conveys the second-form molten metal stream to the extrusion barrel 302 and the injection barrel 301. Then the second-form molten metal stream is injected into the die-casting machine through an injection plunger in the injection module 3. It should be noted that how the injection module 3 injects the molten metal stream in the injection barrel 301 into the die-casting machine is common knowledge known to those skilled in the art, so it is not described in detail herein.

[0045]In this embodiment, as shown in FIG. 6, the melting module 4 includes a melting barrel 401 disposed on a workbench, a conveying mechanism 402, and an injection assembly 403. An injection head 6 at an end of the melting barrel 401 is pressed against and cooperatively communicated with the extrusion barrel 302 (as shown in FIG. 4). The conveying mechanism 402 is disposed inside the melting barrel 401 and is in cooperation with the injection assembly 403.

[0046]It is understandable that during second-mode die-casting (i.e., magnesium alloy die-casting), the melting module 4 implements two processes. In a first process, solid magnesium particles are fed into the melting barrel 401 from a feed port 8. The conveying mechanism 402 conveys the magnesium particles to fill the melting barrel 401, as shown in FIG. 8 (it should be noted that at this moment, the magnesium particles expel the air from the melting barrel 401, preventing air from oxidizing the magnesium alloy subsequently). A heating assembly on the melting barrel 401 melts the metal particles to obtain the second-form molten metal stream, i.e., semi-solid molten metal stream (a state where a liquid encapsulates the solid particles). In a second process, the injection assembly 403 and the conveying mechanism 402 cooperatively operate to inject the second-form molten metal stream into the extrusion barrel 302 from the injection head 6, thereby achieving subsequent die-casting in the second mode.

[0047]Furthermore, an inner diameter of the injection head 6 is smaller than an inner diameter of the extrusion barrel 302. An inner diameter of the injection nozzle 303 is smaller than a diameter of a gate in the cavity. Although the gate is not shown in the present disclosure, it is well-known common knowledge in the art. Specifically, a ball diameter of the injection head 6 is slightly smaller than a ball diameter of the extrusion barrel 302. The inner diameter of the injection nozzle 303 is slightly smaller than the diameter of the gate. This structural design avoids the accumulation of a cold slug at the gate and prevents the molten magnesium from spraying out, providing a good sealing effect and ensuring smooth flow of the molten magnesium.

[0048]As shown in FIG. 7, the conveying mechanism 402 includes a mounting block 4021, a screw 4022, and a driving device 4023 (e.g., a motor). The screw 4022 is similar to a spiral conveyor. The screw 4022 rotates to achieve a conveying purpose. The mounting block 4021 is slidably disposed on the workbench (as shown in FIG. 2, the melting module 4 is entirely disposed on the workbench). The driving device 4023 is disposed on the mounting block 4021. The screw 4022 is located inside the melting barrel 401. A first end (right end) of the screw 4022 is rotatably disposed on the mounting block 4021 and is connected to an output shaft of the driving device 4023 through a spline. That is, the screw 4022 can not only rotate axially but also move axially. The mounting block 4021 is cooperatively connected to the injection assembly 403.

[0049]It is understandable that in the first process, as shown in FIG. 8, the magnesium particles are conveyed. The driving device 4023 drives the screw 4022 to rotate, and the magnesium particles entering from the feed port 8 of the melting barrel 401 are conveyed and distributed inside the melting barrel 401. The feed port 8 is closed to seal the melting barrel 401 and prevent the magnesium particles from contacting external air. The screw 4022 exerts a conveying force on the magnesium particles, and the magnesium particles exert a reaction force on the screw 4022, causing the screw 4022 to move away from the melting barrel 401. Meanwhile, the injection module 3 drives the mounting block 4021 away from the melting barrel 401. This causes the driving device 4023 to move away, thereby not interfering with the movement of the screw 4022. It should be noted that the backward movement of the screw 4022 in this process prepares for the injection of the magnesium material in the second process.

[0050]In the second process, as shown in FIG. 9, the injection assembly 403 drives the mounting block 4021 to reset and move close to the melting barrel 401. That is, the screw 4022 moves toward the interior of the melting barrel 401 under the action of the driving device 4023. During the movement, a screw head 9 at a second end (left end) of the screw 4022 injects the magnesium material into the injection head 6. Then the magnesium material is injected from the injection head 6 into the injection module 3.

[0051]In a further description of the above embodiment, as shown in FIG. 9, the injection assembly 403 includes an injection seat 4031 and an injection shifting cylinder 4032. The injection seat 4031 is disposed on the workbench and corresponds to the mounting block 4021. The melting barrel 401 is fixedly disposed on the injection seat 4031. A cylinder body of the injection shifting cylinder 4032 is hinged to a first connection seat. A piston end of the injection shifting cylinder 4032 is hinged to a second connection seat. The first connection seat is disposed on the injection seat 4031. The second connection seat is disposed on the mounting block 4021.

[0052]It is understandable that a cylinder body part and a piston rod part of the injection shifting cylinder 4032 are respectively disposed on the two connection seats through hinging. The two connection seats are fixed to the injection seat 4031 and the mounting block 4021, respectively, such that the injection shifting cylinder 4032 is fixedly disposed. Through the hinging method, when the mounting block 4021 fails, the second connection seat can be disassembled. Then the injection shifting cylinder 4032 can be rotated around a piston rod and moved away from the mounting block 4021. This eliminates the interference of the injection shifting cylinder 4032 during maintenance of the mounting block 4021. Since only the cylinder body part of the injection shifting cylinder 4032 needs to be disassembled, the maintenance is simple and convenient, and facilitates the re-assembly of the injection shifting cylinder 4032 after maintenance.

[0053]The entire melting module 4 is disposed perpendicular to the die-casting machine body 1, as shown in FIG. 4, FIG. 5A, and FIG. 5B. The melting module 4 is connected in communication through the extrusion barrel 302 contacting the injection head 6. The extrusion barrel 302 may shake during long-term extrusion, thereby affecting the communication and sealing effectiveness between the extrusion barrel and the injection head.

[0054]To solve the above technical problem, in an embodiment of the present disclosure, as shown in FIG. 1 and FIG. 4, a thrust mechanism 5 is disposed on the die-casting machine body 1. The thrust mechanism 5 is in cooperation with the injection module 3 and corresponds to and is disposed parallel to the melting module 4. It is understandable that the thrust mechanism 5 keeps the injection module 3 always pressing against and cooperating with the melting module 4. This keeps the injection module 3 and the melting module 4 always in a sealed state, ensuring stable conveying of the magnesium material during die-casting.

[0055]Specifically, as shown in FIG. 4, the thrust mechanism 5 includes a thrust cylinder 501 and a push head 502. The thrust cylinder 501 is disposed on the fixed platen 2, and the push head 502 is disposed at one end of the piston rod. It is understandable that during die-casting, the thrust cylinder 501 extends and drives the push head 502 to press against an outside of the extrusion barrel 302. That is, during injection, the thrust cylinder 501 pushes the push head 502 to constantly apply a pressure to the extrusion barrel 302. This pressure is simultaneously transmitted to the injection head 6 and the melting barrel 401 to play a sealing role, ensuring stable conveying of the magnesium material during die-casting. The extension and retraction of the thrust cylinder 501 are precisely controlled by a control system to adapt to different pressure requirements in different die-casting stages.

[0056]In this embodiment, as shown in FIG. 5A and FIG. 5B, to further improve the mounting stability of the melting module 4 and the mounting convenience of the thrust cylinder 501, a pair of limit rods 7 is disposed with vertical symmetry and penetrates through the fixed platen 2. Specifically, upper and lower sides of the melting module 4 are respectively provided with connection rods. The connection rods are respectively connected and fixed to first ends (left ends) of the limit rods 7, enabling securing of the melting module 4. Second ends (right ends) of the limit rods 7 are fixedly provided with a vertical plate through a bolt, and the thrust cylinder 501 is fixedly disposed on the vertical plate, enabling securing of the thrust mechanism 5. The limit rods 7 achieve securing of the melting module 4 as well as securing of the thrust mechanism 5. This also ensures the linear alignment between the thrust mechanism 5 and the melting module 4, ensuring the stability and safety of the entire die-casting process.

[0057]In an embodiment of the present disclosure, as shown in FIG. 10 to FIG. 12, the screw head 9 includes a rod head portion 901, a blocking portion 902, a non-return ring 904, a sleeve ring 905, and a gasket 903. The rod head portion 901 is disposed on a second end (left end) of the screw 4022 through a thread, enabling quick disassembly and assembly between the screw head 9 and the screw 4022. The blocking portion 902 and the gasket 903 are disposed outside the rod head portion 901 and form a spacing there-between. A plurality of material grooves 10 are disposed outside the blocking portion 902. The sleeve ring 905 is sleeved outside the non-return ring 904 and contacts an inner wall of the melting barrel 401. The non-return ring 904 is sleeved on the rod head portion 901 and corresponds to the spacing. An axial length of the non-return ring 904 is less than a length of the spacing. A flow channel 11 in communication with the material grooves 10 is formed between an interior of the non-return ring 904 and the spacing.

[0058]It is understandable that a flow direction of the magnesium material in the melting barrel 401 is indicated by arrows shown in FIG. 11A. Since the non-return ring 904 is movably sleeved on the rod head portion 901, the non-return ring 904 contacts the blocking portion 902 on the left due to a flow force of the magnesium material, and a gap 12 is formed between the non-return ring 904 and the gasket 903 on the right. Under the conveying action of the screw 4022, the magnesium material on the right of the melting barrel 401 flows from the gap 12, the flow channel 11, and the material grooves 10 to a storage chamber on the left of the melting barrel 401, as shown in FIG. 8.

[0059]During injection, as shown in FIG. 9, the screw head 9 moves to the left under the action of the screw 4022, and the magnesium material in the storage chamber is injected from the injection head 6 into the injection module 3. During this process, the magnesium material may flow back under the reaction force, as shown in FIG. 11B. Due to this reaction force, the non-return ring 904 contacts the gasket 903 on the right, and the gap 12 is closed, which blocks the magnesium material and prevents its backflow, thereby improving the utilization of the magnesium material. As shown in FIG. 12, a right side of the non-return ring 904 is provided with a plurality of notches. When the non-return ring 904 contacts the gasket 903, the gap 12 is narrowed but not closed due to the notches. This prevents leakage of the melting barrel 401 or the extrusion barrel 302 due to an excessive force of the magnesium material. That is, while the gap 12 ensures full injection of the magnesium material, it can also buffer a backflow force of the magnesium material to ensure smooth progress of the entire die-casting process. In the specific setting of the gap 12, whether to narrow or close the gap 12 during backflow can be selected by those skilled in the art according to the actual situation.

[0060]In this embodiment, as shown in FIG. 1, the injection platen 16 is disposed on a left side of the fixed platen 2, i.e., inside the die-casting machine body 1. In actual use, the injection platen 16 has different models for different products. However, since the fixed platen 2 is fixedly disposed, replacing the injection platen 16 becomes inconvenient. It should be noted that the injection platen 16 is provided with a fixed die insert, and an area inside the die-casting machine body 1 corresponding to the injection platen 16 is provided with a moving platen and a moving die insert connected to the moving platen. The fixed die insert and the moving die insert are in cooperation to form the cavity (i.e., the die cavity) of the die-casting machine. These are common knowledge known to those skilled in the art.

[0061]To solve the above technical problem, an entire die bridge assembly 13 is disposed on a frame inside the die-casting machine body 1, as shown in FIG. 13. The fixed platen 2 is fixedly disposed at a right side of the die bridge assembly 13. A die bridge 14 is slidably disposed in the die bridge assembly 13. The injection platen 16 is disposed on the die bridge 14. A tray cylinder 15 is disposed at a bottom end of the fixed platen 2. One end of a piston rod of the tray cylinder 15 is connected to the die bridge 14.

[0062]It is understandable that when the tray cylinder 15 retracts, the injection platen 16 presses against and cooperates with the fixed platen 2, and thus the injection platen 16 is mounted and ready for operation. During disassembly, the tray cylinder 15 first extends to move the injection platen 16 away from the fixed platen 2. Then the injection platen 16 is disassembled from the die bridge 14. It should be noted that, compared with the prior art, the mounting between the injection platen 16 and the fixed platen 2 is designed as the mounting between the injection platen 16 and the die bridge 14. The position of the die bridge 14 is adjustable via the tray cylinder 15, which facilitates the subsequent disassembly and assembly of the fixed platen 2.

[0063]The working principle of the magnesium-aluminum dual-injection die-casting machine in the present disclosure is as follows:

[0064]First, the user selects the corresponding mode according to the product to be injection-molded. For example, the aluminum alloy injection mode is selected through an operation screen on the die-casting machine, and the magnesium alloy injection is not used. The system-built parameters are suitable for aluminum alloy die-casting. Specifically, the molten aluminum melted outside is added to the injection module 3. Then the injection module 3 injects the molten aluminum into the die-casting machine for forming.

[0065]In the magnesium alloy injection mode, the raw magnesium material undergoes two processes under the action of the melting module 4. In a first process, as shown in FIG. 8, magnesium particles enter from the feed port 8 of the melting barrel 401 (corresponding to an upper end of the injection seat 4031). The driving device 4023 drives the screw 4022 to rotate for material storage. The screw 4022 moves backward due to the reaction force from compacting the magnesium particles. Meanwhile, the mounting block 4021 moves backward under the action of the injection shifting cylinder 4032. After material storage is completed, the mounting block 4021 resets and moves forward under the action of the injection shifting cylinder 4032. The semi-molten magnesium in the melting barrel 401 is pushed from the injection head 6 into the extrusion barrel 302. Finally, the injection module 3 injects the semi-solid magnesium into the die to complete the entire injection process.

[0066]It should be noted that the injection barrel 301, the extrusion barrel 302, the injection nozzle 303, the melting barrel 401, and the injection head 6 are each externally provided with a heating ring. The magnesium material is heated to a semi-solid state during conveying and the temperature of the molten magnesium is kept constant. Compared with conventional cold-chamber die-casting machines, the present disclosure significantly reduces energy consumption by greatly reducing the working temperature, reducing the magnesium content in castings, and lowering the system's high power consumption. The magnesium melting module 4 completes the injection in a fully enclosed environment, which eliminates the need for SF6 protective gas, reducing costs, improving safety, and achieving environmental protection. Meanwhile, by simplifying the injection system and separating the melting structure and the injection structure, the magnesium melting module 4 can be easily disposed on an existing cold-chamber die-casting machine. This simplifies equipment setup, reduces maintenance costs, and enables stable and continuous production.

[0067]It should be noted that the injection action of the existing cold-chamber die-casting machine is divided into three processes: slow injection, fast injection, and boost injection. Before completing fast injection and preparing for boost injection, the injection cylinder 19 needs to be braked. After the die-casting machine completes the injection action, a pressure relief process, a tracking process, and a plunger return process are needed to return to an initial position. These are common knowledge known to those skilled in the art.

[0068]As shown in FIG. 14, the molten metal stream in the injection barrel 301 is injected into the die-casting machine body 1 through the injection plunger. For molten aluminum, since it is in a pure liquid state, a slow injection process is needed at the initial stage of injection. If fast injection is performed at the early stage, the molten aluminum will generate a large thrust and fluctuate, which will cause “surge” and affect forming quality. When the molten aluminum fills the injection barrel 301, the fast injection process can be performed.

[0069]Therefore, another aspect of the present disclosure provides a magnesium-aluminum dual-injection system employing the above magnesium-aluminum dual-injection die-casting machine. When first-mode (i.e., aluminum alloy) die-casting is performed, the following steps are included: slow injection, fast injection, and boost injection. When second-mode (i.e., magnesium alloy) die-casting is performed, the following steps are included: fast injection and boost injection.

[0070]It should be noted that since magnesium alloy is semi-solid after being melted, it can hardly generate the “surge” phenomenon as in the molten aluminum during pushing. Therefore, the second mode does not require the slow injection step, which simplifies the operation process and improves production efficiency. In actual operation, the two injection modes share one injection system. After the corresponding injection mode is selected through a control panel, the system automatically adjusts corresponding parameters to adapt to the injection requirements of different materials.

[0071]In a further description of the above die-casting steps, as shown in FIG. 15 to FIG. 17, the magnesium-aluminum dual-injection system includes an accumulator 18, an injection cylinder 19, a booster cylinder 17, and a valve module connected through oil lines. In the figures, the thick solid lines indicate oil lines that are communicated, the dashed lines indicate oil lines that are not communicated, P indicates an oil pump, and T indicates an oil tank.

[0072]Specifically, as shown in FIG. 15, the valve module includes a switching valve V4, a switching valve V5, a switching valve V8, a servo valve V9, a one-way valve V11, and a one-way valve V13. An output end of the oil pump is connected to a rod chamber of the injection cylinder 19 to form a first oil line through the one-way valve V11 and the servo valve V9 that are sequentially connected. The output end of the oil pump is connected to a rodless chamber of the injection cylinder 19 to form a second oil line through the one-way valve V11, the one-way valve V13, the switching valve V8, and the switching valve V5 that are sequentially connected. When the oil pump supplies oil alone during slow injection, the oil pump supplies the oil to the rodless chamber of the injection cylinder 19 through the second oil line in communication. The first oil line and the second oil line intersect at an output end of the one-way valve V11 to form a differential circuit. The oil pump and the accumulator 18 can supply oil jointly. That is, the accumulator 18 supplies the oil to the rodless chamber of the injection cylinder 19 through the switching valve V4 and the switching valve V5, and the oil pump can replenish the accumulator 18 through the connected switching valve V12.

[0073]It is understandable that differential control is applied in the slow injection stage to ensure stable slow injection and control the speed of slow injection by controlling the flow in the rod chamber of the injection cylinder 19 through the servo valve V9. During differential control, the pressure difference before and after the servo valve V9 is smaller than that during conventional separate outlet control. This enables a small pressure gain of the servo valve V9, thereby improving the control accuracy of the injection cylinder 19. In addition, before slow injection starts, pressure buildup in the rod chamber of the injection cylinder 19 is completed during the energy storage stage. Thus, the compression amount of the oil in the rod chamber is reduced at the start of slow injection, thereby preventing or reducing the startup shock.

[0074]As shown in FIG. 16, the valve module further includes a servo valve V7. The oil tank is connected to the rod chamber of the injection cylinder 19 through the servo valve V7 to form a third oil line. During the fast injection and a braking, the accumulator 18 supplies oil to the rodless chamber of the injection cylinder 19 through the switching valve V4 and the switching valve V5. The pressure oil in the rod chamber of the injection cylinder 19 flows back to the oil tank through the servo valve V7. The first oil line and the third oil line are connected to form a first A-type half-bridge, and the injection speed of the injection cylinder 19 is adjusted by controlling openings of the servo valve V7 and the servo valve V9.

[0075]It is understandable that during the fast injection stage, the opening of the servo valve V7 is large, while the opening of the servo valve V9 is small. This allows the pressure oil in the rod chamber of the injection cylinder 19 to quickly flow back to the oil tank, thereby generating a fast injection speed. By connecting the first oil line to form the first A-type half-bridge during the fast injection stage, the flow in the rod chamber of the injection cylinder 19 can be quickly adjusted by controlling the opening of the servo valve V9 to achieve precise speed control, thereby reducing or avoiding high-speed overshoot.

[0076]Meanwhile, during the braking stage, the opening of the servo valve V7 is small, while the opening of the servo valve V9 is large. This increases the pressure in the rod chamber of the injection cylinder 19 to achieve active braking. The oil supply from the oil pump can build up the pressure in the rod chamber of the injection cylinder 19 quickly through the first A-type half-bridge, so as to complete the active braking action with fast deceleration.

[0077]As shown in FIG. 17, the valve module further includes a switching valve V6. The accumulator 18 is connected to a rodless chamber of the booster cylinder 17 to form a fourth oil line through the switching valve V4. The oil tank is connected to a rod chamber of the booster cylinder 17 to form a fifth oil line through the servo valve V7 and the switching valve V6 that are sequentially connected. The output end of the oil pump is connected to the rod chamber of the booster cylinder 17 to form a sixth oil line through the one-way valve V11, the servo valve V9, and the switching valve V6 that are sequentially connected. During the boost injection stage, the accumulator 18 supplies oil to the rodless chamber of the booster cylinder 17 through the fourth oil line in communication. The pressure oil in the rod chamber of the booster cylinder 17 and the pressure oil in the rod chamber of the injection cylinder 19 flow back to the oil tank through the fifth oil line in communication and the servo valve V7, respectively. The sixth oil line and the fifth oil line are connected to form a second A-type half-bridge, and the boost pressure of the booster cylinder is adjusted by controlling the openings of the servo valve V9 and the servo valve V7.

[0078]It is understandable that the boost pressure is precisely controlled through the second A-type half-bridge as follows. During the delay stage before pressure buildup, in order to achieve fast pressure buildup during the boost injection stage, the servo valve V7 is opened to a preset fixed opening, and the servo valve V9 is also opened to a preset fixed opening. When the pressure in the rodless chamber of the injection cylinder 19 reaches a certain proportion of a first-stage preset value, the opening of the servo valve V7 is reduced to a specific set value. Then the opening of the servo valve V9 is adjusted to alter the flow passing through the servo valve V9, ensuring that the flow through the servo valve V9 and the flow from the rod chamber of the booster cylinder 17 create a pressure drop when passing through the servo valve V7. This pressure drop corresponds to the pressure in the rod chamber of the booster cylinder 17, and the boost pressure can be adjusted by controlling the pressure in the rod chamber of the booster cylinder 17. Therefore, by adjusting the opening of the servo valve V9 to control the flow, and subsequently controlling the pressure drop of the servo valve V7, the boost pressure can be controlled. This control method enhances the precision of boost pressure adjustment and allows for the adjustment of the boost pressure from high to low, thereby enabling correction of the boost pressure after overshooting.

[0079]It should be noted that during boost injection, the switching valve V12 can be connected, so the oil pump can replenish the accumulator 18 through the second oil line in communication. Replenishing the accumulator 18 can increase the pressure of the accumulator 18, ensuring that the accumulator 18 has a sufficient pressure in the subsequent tracking stage. Meanwhile, the injection cylinder 19 and the booster cylinder 17 share the accumulator 18. The accumulator 18 is loaded and replenished during both the boost injection stage and the slow injection stage, which can further reduce the volume of the accumulator 18 to reduce costs.

[0080]The basic principles, main features, and advantages of the present disclosure are described above. It should be understood by those skilled in the art that the present disclosure is not limited by the above embodiments, and the above embodiments and the description only illustrate the principle of the present disclosure. Various changes and modifications may be made to the present disclosure without departing from the spirit and scope of the present disclosure, and such changes and modifications all fall within the protection scope of the present disclosure. The protection scope of the present disclosure is defined by the appended claims and equivalents thereof.