Die casting simulation device and method thereof

Abstract

The invention relates to the technical field of integrated die casting, and discloses a die casting simulation device and a method thereof.The die casting simulation device comprises a test runner module, a pressure applying unit and an injection unit, and the test runner module comprises a first die and a second die which are stacked in the first direction; the surface, facing the second mold, of the first mold is provided with a test flow channel, the test flow channel module is further provided with an air outlet and a liquid inlet, the test flow channel is communicated with the air outlet and the liquid inlet, and the part, located between the air outlet and the liquid inlet, of the test flow channel is provided with a plurality of semicircular arc sections; the pressure applying unit applies preset pressure to the second mold; the injection unit injects molten metal into the liquid inlet at a preset flow rate; wherein the test flow channel is configured to extend from the liquid inlet through multiple roundabout bends and is communicated with the air outlet and is communicated with the air outlet. Therefore, the forced filling state of the molten metal under high pressure in the die-casting process can be reduced, and then the accuracy of simulating die-casting forming is improved.

Description

Technical Field

[0001] This invention relates to the field of integrated die-casting technology, specifically to a die-casting simulation device. Furthermore, this invention also relates to a die-casting simulation method using this device. Background Technology

[0002] In recent years, with the increasing demand for lightweight automobiles, miniaturized electronic devices, and integrated aerospace structures, heat-treatable die-cast magnesium alloys have been widely used in the manufacture of large, thin-walled, and complex structural components due to their advantage of meeting performance requirements immediately upon forming. Before using heat-treatable magnesium alloys in integrated die-casting production, it is crucial to accurately assess their fluidity in the molten state to guide mold gate design, test runner layout, and the setting of process parameters such as injection speed and injection temperature.

[0003] However, current testing methods generally suffer from a mismatch between the testing conditions and actual die-casting scenarios. Specifically, the spiral specimen method, U-shaped specimen method, and wedge specimen method are mostly based on low-pressure, open, or uncontrolled mold structures, making it difficult to simulate the high-speed injection and rapid solidification during die casting. The spherical specimen method is only suitable for judging static fluidity and cannot reflect the inertial flow and turbulent behavior under die-casting conditions. The vacuum specimen method relies on negative pressure suction casting, which is inconsistent with the high-pressure filling characteristics of die casting. Therefore, the fluidity data obtained by existing methods are difficult to use to guide the design of actual die-casting molds and process settings, and cannot meet the application requirements of heat-free magnesium alloys in the field of integrated die casting. Summary of the Invention

[0004] One objective of this invention is to provide a die-casting simulation device to solve the above-mentioned technical problems; another objective is to provide a die-casting simulation method.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, a die-casting simulation device is provided, comprising a test flow channel module, a pressure application unit, and an injection unit. The test flow channel module includes a first mold and a second mold stacked along a first direction. A test flow channel is formed on the surface of the first mold facing the second mold. The test flow channel module is also provided with an air outlet and a liquid inlet. The test flow channel is connected to the air outlet and the liquid inlet. The portion of the test flow channel located between the air outlet and the liquid inlet has multiple semi-circular arc segments. The pressure output end of the pressure application unit abuts against the surface of the second mold away from the first mold and is capable of applying a preset pressure to the second mold. The injection unit is connected to the liquid inlet and is configured to inject molten metal into the liquid inlet at a preset flow rate. The test flow channel is constructed to extend from the liquid inlet through multiple meandering bends to the air outlet and is connected to the air outlet.

[0006] Based on the above technical means, the present invention sets the pressure value applied by the pressure unit and the preset flow rate of the solution injected by the injection unit so that the molten metal exhibits a stress state that is closer to the actual die casting conditions during the flow process. At the same time, it simulates the high-speed flow state of the molten metal entering the mold cavity under the drive of the injection system during the die casting process, so that the molten metal forms an inertial flow and shear effect similar to the actual die casting in the curved test channel, thereby restoring the forced filling state of the molten metal under high pressure during the die casting process.

[0007] Furthermore, the die-casting simulation device also includes a support frame, on which the first mold is supported. The die-casting simulation device also includes a demolding structure, which is connected to the support frame and located below the first mold. A portion of the demolding structure passes through the first mold and extends into the test flow channel. The demolding structure is configured to be able to move relative to the support frame in a first direction.

[0008] Based on the aforementioned technical means, the demolding structure ensures that the geometry of the flow channel and the testing conditions are not affected during the testing process. Furthermore, it enables the smooth ejection and complete removal of the sample after testing, thus guaranteeing the smooth conduct of subsequent testing and analysis of the sample's fill length, molding integrity, and surface quality. In addition, this structure reduces the time consumption and mold wear caused by frequent mold disassembly, improves the reusability and testing efficiency of the testing device, and makes this embodiment more suitable for batch flowability testing and comparative experiments.

[0009] Furthermore, the test flow channel includes multiple straight sections and multiple semi-circular arc sections, which are sequentially and alternately connected to form a serpentine test flow channel. There are three sets of ejector pins, which are spaced apart along the direction of two consecutive semi-circular arc sections of the test flow channel. The tops of the ejector pins in the two sets on both sides extend into the semi-circular arc sections on both sides of the test flow channel, while the top of the ejector pin in the middle set extends into the straight section.

[0010] According to the above-mentioned technical means, the tips of the two sets of ejector pins on both sides extend into multiple semi-circular arc segments set at both ends of the test flow channel, while the tip of the set of ejector pins in the middle extends into the position corresponding to the center area of ​​the straight segment. This forms a multi-point ejection of the specimen within the test flow channel, thereby applying a distributed ejection force to the specimen during the demolding stage. This allows the specimen to detach from the test flow channel as a whole under the simultaneous force applied at multiple positions, ensuring that the specimen retains its original geometric shape after demolding. This facilitates the subsequent detection and evaluation of the molding quality of the specimen filling.

[0011] Furthermore, a first limiting structure is formed on the support frame. The first limiting structure and the first mold are spaced apart along the first direction and located below the base plate. When the ejector pin abuts against the first limiting structure, the top of the ejector pin is flush with the inner bottom surface of the test flow channel.

[0012] According to the above technical means, when the base plate abuts against the first limiting structure, the distance between the top of the ejector pin and the surface of the base plate facing the first mold is the same as or slightly less than the distance in the first direction between that surface and the bottom end face of the test runner, thereby ensuring that the ejector pin will not protrude into the test runner in the initial state. During the demolding stage, after the test is completed and the molded specimen has solidified in the test runner, the base plate is driven by the drive mechanism to detach from the first limiting structure and continue to move towards the first mold in the first direction, so that multiple ejector pins simultaneously extend into the test runner, thereby applying an upward ejection force to the molded specimen and stably ejecting the specimen from the test runner, achieving non-destructive demolding.

[0013] Furthermore, the first limiting structure includes at least two support protrusions, which are respectively located on both sides of the support frame and can support the base plate.

[0014] According to the above-mentioned technical means, the support protrusion constitutes the aforementioned first limiting structure.

[0015] Furthermore, a second limiting structure is formed on the support frame. The second limiting structure is located below the first mold. The bottom plate is set to be spaced apart from the second limiting structure along the first direction. The bottom plate is set to move upward along the first direction by a preset distance so as to abut against the second limiting structure.

[0016] Based on the aforementioned technical means, the upper stop point of the base plate movement is restricted.

[0017] Furthermore, the base plate is also provided with guide posts, which extend along the first direction. The first mold is provided with corresponding guide holes, and the guide posts are slidably inserted into the guide holes.

[0018] According to the above-mentioned technical means, the wall pins are deflected and bent.

[0019] Furthermore, the support frame includes two support strip plates arranged opposite to each other. At least one support strip plate has a fixed shaft at its top. The first mold has a fixed hole. The fixed shaft is arranged to extend along a first direction and is inserted into the fixed hole.

[0020] The above-mentioned technical means are used to position the support frame and the first mold.

[0021] Furthermore, a first cold runner is provided on the first mold, which is located below the test runner, and coolant flows through the first cold runner.

[0022] Based on the above technical means, heat is dissipated from the side test flow channel, thereby controlling the temperature inside the test flow channel.

[0023] Furthermore, a second cold runner is provided on the second mold, which is spaced apart from the first cold runner on the first mold, and coolant flows through the second cold runner.

[0024] Based on the above technical means, the heat dissipation capacity of the test flow channel is enhanced.

[0025] Furthermore, the preset pressure includes 50-150 MPa; and / or, the preset flow rate includes 0.5-5 m / s; and / or, the cross-section of the test channel is trapezoidal, and the bottom end face of the test channel forms the short parallel side of the trapezoid.

[0026] Based on the above-mentioned technical means, the present invention can simulate the molding environment during die casting to the greatest extent.

[0027] Secondly, a die-casting simulation method is provided, including the die-casting simulation apparatus as described above.

[0028] The present invention has at least the following beneficial effects: This invention simulates the high-speed flow state of molten metal entering the mold cavity under the drive of the injection system during the die casting process. It enables the molten metal to form an inertial flow and shear effect similar to that in actual die casting within the curved test channel, thereby restoring the forced filling state of molten metal under high pressure during the die casting process. Attached Figure Description

[0029] Figure 1 This is a three-dimensional structural view of the die-casting simulation device according to an embodiment of the present invention; Figure 2 This is a top-view perspective view of the second mold according to an embodiment of the present invention; Figure 3 This is a top-view perspective view of the first mold according to an embodiment of the present invention; Figure 4 This is a perspective view of the support frame according to an embodiment of the present invention; Figure 5 This is a perspective view of the support frame and the first mold installation structure according to an embodiment of the present invention.

[0030] The components include: 1. Test runner module; 101. First mold; 1011. Fixing hole; 1012. Ejector pin through hole; 102. Second mold; 1021. Guide positioning through hole; 103. Liquid inlet; 104. Air outlet; 105. First cold runner; 106. Second cold runner; 107. Vent plate; 1071. Vent cavity; 2. Support frame; 201. Support strip plate; 202. Fixing shaft; 3. Demolding structure; 301. Base plate; 302. Ejector pin; 303. Guide post; 304. Guide hole; 4. Test runner; 401. Straight section; 402. Semi-circular arc section; 5. First limiting structure; 501. Protrusion; 6. Second limiting structure. Detailed Implementation

[0031] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0032] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0033] In this technical field, integrated die casting technology places far higher demands on the ability of molten metal to fill the mold cavity at high speed and high pressure than traditional die casting. The fluidity of the molten metal has become a key indicator determining whether the die casting can be formed completely and the product qualification rate. If the fluidity of the molten metal is insufficient, under the combined effect of high-speed filling and rapid cooling, defects such as under-casting, cold shuts, and porosity are easily formed in the mold cavity. This not only significantly increases the scrap rate and production costs, but may also cause safety hazards such as insufficient structural strength, seriously restricting the engineering application of integrated die casting technology.

[0034] As mentioned above, the main testing methods used in industry for the fluidity of die-casting alloys include the spiral specimen method, spherical specimen method, U-shaped specimen method, wedge specimen method, and vacuum specimen method. However, the core requirement for fluidity testing in die-casting scenarios is to accurately simulate the entire process of molten metal flow, filling, and solidification within the mold cavity during actual die-casting. This necessitates strict matching with the high-pressure environment, high-speed injection conditions, and specific mold heat dissipation characteristics of the die-casting process. The existing methods described above differ significantly from the die-casting scenario in terms of testing principles, mold structure, and adaptability to operating conditions. First, although the spiral sample method characterizes flowability through the forming length of the spiral cavity, its molds are mostly open or low-pressure designs, which do not simulate the high-pressure filling environment of die casting. Moreover, the single flow channel resistance of the spiral cavity differs greatly from the flow field distribution of the actual complex die casting cavity (including multiple gates, thin-walled sections, and corner structures), and cannot reflect the true flow resistance.

[0035] Secondly, the spherical sample method judges the fluidity by assessing the integrity of the molten metal filling the spherical cavity. It is only suitable for evaluating the static fluidity of low-viscosity alloys and cannot reflect the inertial flow and turbulence effect of molten metal under high-speed injection in die casting. It is out of touch with the dynamic flow process of actual die casting.

[0036] Meanwhile, the U-shaped sample method relies on the rising height or filling length of the molten metal within the U-shaped channel to assess flowability. However, the channel cross-sectional area is fixed and lacks a cooling system specific to die-casting molds, making it impossible to simulate the rapid solidification characteristics of the molten metal after contact with the mold cavity wall during die casting. This results in significant discrepancies between the test results and actual solidification behavior. The wedge-shaped sample method judges flowability based on the maximum filling thickness of the molten metal within a wedge-shaped (gradually varying thickness) cavity. While this can partially reflect thin-wall filling capacity, the mold lacks a dedicated gate-runner system for die casting and does not apply high-pressure injection force typical of die casting. Therefore, it fails to reflect the beneficial effect of pressure on molten metal flow, which is inconsistent with the actual "pressure-flow" synergistic mechanism of die casting.

[0037] In addition, the vacuum sample method tests the casting length of molten metal in a negative pressure environment (vacuum degree is usually ≥0.095MPa). Although it can reduce the interference of molten metal oxidation, the vacuum environment is completely contrary to the normal pressure / slight positive pressure conditions of die casting. Moreover, there is no synergistic effect of mold clamping force and high pressure injection during the test process, and the measured flowability data deviates significantly from the actual die casting scenario.

[0038] Therefore, none of the existing testing methods can fully match the high pressure, high speed, mold cooling and complex cavity characteristics of die casting, making it difficult for the test results to effectively guide the design of die casting molds and the setting of process parameters. This has become a technical bottleneck restricting the precise application of heat-free magnesium alloys in the field of integrated die casting.

[0039] To address the above issues, refer to Figure 1 as well as Figure 5 This embodiment provides a die-casting simulation device for simulating die-casting flow conditions, comprising a test flow channel module 1, a pressure application unit, and an injection unit. The test flow channel module 1 includes a first mold 101 and a second mold 102 stacked vertically, meaning the second mold 102 abuts against the first mold 101 along a first direction (vertical). Referring to the figure, a test flow channel 4 is formed on the surface of the first mold 101 facing the second mold 102, and a liquid inlet 103 is provided at one end of the test flow channel 4, which is connected to the injection unit. An air outlet 104 is provided at the other end of the test flow channel 4 for discharging air from the flow channel. The test flow channel 4 is connected to the air outlet 104 and the liquid inlet 103, and the portion of the test flow channel 4 located between the air outlet 104 and the liquid inlet 103 has multiple semi-circular arc segments 402.

[0040] The pressure output end of the pressure application unit abuts against the side surface of the second mold 102 away from the first mold 101, and is configured to apply a preset pressure to the test flow channel module 1 to simulate the high-pressure cavity environment formed by the mold under high pressure clamping force during the die casting process.

[0041] The injection unit is used to inject molten metal into the inlet 103 and is configured to inject molten metal into the test channel 4 at a preset flow rate to simulate the high-speed flow state of molten metal entering the mold cavity under the drive of the injection device during the die casting process.

[0042] Therefore, this embodiment sets the pressure applied by the pressure unit and the preset flow rate of the solution injected by the injection unit to make the molten metal exhibit a stress state that is closer to the actual die casting conditions during the flow process. At the same time, it simulates the high-speed flow state of the molten metal when it enters the mold cavity under the drive of the injection system during the die casting process. This allows the molten metal to form an inertial flow and shear effect similar to the actual die casting in the test flow channel 4, thereby restoring the forced filling state of the molten metal under high pressure during the die casting process.

[0043] Further, refer to Figure 2 , Figure 3 as well as Figure 5 The test flow channel 4 is constructed by extending from the liquid inlet 103 to the air outlet 104 after multiple bends and twists, forming a complex and tortuous flow path. Multiple continuous straight sections 401 and semi-circular arc sections 402 (with corners up to 180°) are combined within the test flow channel 4 to effectively simulate the complex cavity features commonly found in actual integrated die-casting molds, such as corner structures, long-flow thin-walled channels, and multi-path confluence. Simultaneously, this multi-bending structure can generate localized abrupt changes in flow velocity, accumulated pressure loss, and superimposed effects of temperature changes during the test, thereby replicating the path flow resistance and morphological changes faced by molten metal in actual die casting.

[0044] Therefore, this embodiment can construct test conditions close to the actual die-casting environment at the experimental device level, realizing a true characterization of the flow properties of molten metal. Compared with the straight flow channel or open test methods in related technologies, this embodiment can more accurately reflect the flow attenuation characteristics of materials under high pressure, high speed, and complex cavity conditions, thereby significantly improving the guiding value of the flowability assessment results for mold design and process parameter optimization.

[0045] In this embodiment, the preset pressure may include 50-150 MPa, and the preset flow rate may include 0.5-5 m / s. The cross-section of the test channel 4 may be constructed as a trapezoid, and the bottom end face of the test channel 4 forms the short parallel side of the trapezoid.

[0046] The total flow length of the test channel 4 can be 4500mm, and the turning angle of the test channel 4 is set to 180°, thereby restoring the path flow resistance and morphological changes faced by the molten metal in actual die casting.

[0047] In this embodiment, both the first mold 101 and the second mold 102 can form a breathable plate 107, and the two breathable plates 107 form a breathable cavity 1071 inside. After the first mold 101 and the second mold 102 are stacked and installed, the breathable plates 107 interlock to form a complete cavity. The breathable cavity 1071 on the breathable plate 107 of the first mold 101 can be connected to the end of the test flow channel 4. The above-mentioned air outlet 104 can be provided on the breathable plate 107 of the second mold 102, and the air outlet 104 is connected to the breathable cavity 1071 on the breathable plate 107 of the second mold 102.

[0048] In addition, the surface of the second mold 102 facing away from the first mold 101 is provided with a guide positioning through hole 1021, and the guide post on the pressure unit can be inserted into the guide positioning through hole 1021 to position the pressure unit and the second mold 102.

[0049] In one embodiment, reference Figure 1 and Figure 4 The die-casting simulation device also includes a support frame 2, on which the first mold 101 is mounted and supported to provide stable first-direction support for the test flow channel module 1.

[0050] The die-casting simulation device also includes a demolding structure 3, which is used to drive the molded sample out of the runner. Specifically, the demolding structure 3 is located below the first mold 101 and connected to the support frame 2. Parts of the demolding structure 3 pass through the first mold 101 and extend into the test runner 4. The demolding structure 3 is configured to move relative to the support frame 2 toward or away from the second mold 102, so as to apply an upward ejection force to the sample solidified in the test runner 4 after the test is completed, thereby separating the sample from the mold.

[0051] Understandably, during the testing phase, the demolding structure 3 is in its initial retracted state, with its components extending into the test channel 4 flush with the inner wall of the channel or slightly below the bottom surface of the test channel 4. This avoids interfering with the normal flow of the molten metal, allowing the molten metal to flow and fill completely and continuously within the test channel 4. During the demolding phase, once the test is complete and the molten metal has fully solidified within the test channel 4, the demolding structure 3 moves upward along the first direction, causing the ejector component, which passes through the first mold 101, to press against the bottom of the sample, ejecting the molded sample entirely from the test channel 4. This prevents sample breakage or channel damage caused by forced prying or demolding.

[0052] Therefore, in this embodiment, the demolding structure 3 ensures that the geometry of the flow channel and the test conditions are not affected during the test, and that the sample can be smoothly ejected and completely removed after the test, thus ensuring that subsequent testing and analysis of the sample filling length, molding integrity, and surface quality can be carried out smoothly. Furthermore, this structure reduces the time consumption and mold wear caused by frequent mold disassembly, improves the reusability and testing efficiency of the testing device, and makes this embodiment more suitable for batch flowability testing and comparative experiments.

[0053] In this embodiment, the demolding structure 3 can move upward or downward along the first direction under the drive of an external driving mechanism (such as a hydraulic drive or a mechanical transmission mechanism).

[0054] In this embodiment, the demolding structure 3 can be implemented in any suitable form. (See reference...) Figure 2 In one specific embodiment shown, the demolding structure 3 includes a base plate 301 and a plurality of ejector pins 302 mounted on the base plate 301. The base plate 301 and the first mold 101 are spaced apart in a first direction, and the base plate 301 is slidably connected to the support frame 2 in the first direction, so that the base plate 301 can reciprocate in the first direction under the action of an external driving mechanism.

[0055] Multiple ejector pins 302 are fixedly connected to the base plate 301 and extend towards the first mold 101 along the first direction. The tips of the ejector pins 302 respectively pass through the ejector pin through holes 1012 on the first mold 101 and extend into the test flow channel 4. In the initial state, the tips of the ejector pins 302 are flush with or slightly lower than the bottom surface of the test flow channel 4, so that the ejector pins 302 do not affect the normal flow and filling behavior of the molten metal in the test flow channel 4 during the testing phase.

[0056] During the demolding stage, after the molten metal solidifies in the test channel 4, the base plate 301 moves upward along the first direction under the drive mechanism. Multiple ejector pins 302 simultaneously push the lower surface of the molded sample, thereby ejecting the sample as a whole from the test channel 4, achieving reliable separation of the sample from the first mold 101. Through the synchronous action of multiple ejector pins 302, the ejection force can be evenly distributed on the bottom of the sample, avoiding stress concentration during demolding that could lead to breakage or deformation, thus improving the stability and integrity of the sample removal.

[0057] In this embodiment, reference Figure 3 and Figure 5The test flow channel 4 includes multiple semi-circular arc segments 402 and straight segments 401 connecting adjacent semi-circular arc segments 402. The overall structure of the test flow channel 4 is an approximate structure. The ejector pins 302 are arranged in three groups, and the three groups of ejector pins 302 are spaced apart along the extension direction of two adjacent semi-circular arc segments 402 along the test flow channel 4.

[0058] Specifically, the tips of the two sets of ejector pins 302 on both sides extend into the positions of multiple semi-circular arc segments 402 at both ends of the test flow channel 4, while the tip of the set of ejector pins 302 in the middle extends into the position corresponding to the center area of ​​the straight segment 401. This forms a multi-point ejection of the specimen within the test flow channel 4, thereby applying a distributed ejection force to the specimen during the demolding stage. This allows the specimen to detach from the test flow channel 4 as a whole under the simultaneous force applied at multiple positions, ensuring that the specimen retains its original geometric shape after demolding. This facilitates the subsequent detection and evaluation of the molding quality of the specimen filling.

[0059] In one embodiment, reference Figure 4 A first limiting structure 5 is formed on the support frame 2, and the first limiting structure 5 is spaced apart from the first mold 101 in the first direction. When the base plate 301 moves upward and abuts against the first limiting structure 5, the demolding structure 3 is in the above-mentioned initial retracted state. At this time, the tops of the multiple ejector pins 302 are flush with or slightly lower than the inner bottom surface of the test flow channel 4, so as to avoid the ejector pins 302 interfering with the flow process of the test solution during the testing stage.

[0060] In other words, when the base plate 301 abuts against the first limiting structure 5, the distance between the top of the ejector pin 302 and the surface of the base plate 301 facing the first mold 101 is the same as or slightly less than the first direction distance between the surface and the bottom surface of the test flow channel 4, thereby ensuring that the ejector pin 302 will not protrude into the test flow channel 4 in the initial state.

[0061] During the demolding stage, after the test is completed and the molded specimen has solidified in the test runner 4, the base plate 301 is driven by the drive mechanism to detach from the first limiting structure 5 and continue to move toward the first mold 101 in the first direction, so that multiple ejector pins 302 simultaneously extend into the test runner 4, thereby applying an upward ejection force to the molded specimen and stably ejecting the specimen from the test runner 4 to achieve non-destructive demolding.

[0062] Meanwhile, the die-casting simulation device in this embodiment is positioned in the first direction. Therefore, the demolding structure 3 will fall to the top of the first limiting structure 5 under its own gravity.

[0063] Since the ejector pin 302 is always inserted into the first mold 101, in order to avoid deformation of the ejector pin 302 during movement, in one embodiment, the base plate 301 is also provided with a guide post 303. The guide post 303 extends along the first direction, and the first mold 101 is correspondingly provided with a guide hole 304. The guide post 303 is slidably connected to the guide hole 304, so as to form a positioning function between the first mold 101 and the support frame 2, while restricting the movement direction of the base plate 301, thereby avoiding the movement direction from deviating and causing the ejector pin 302 to bend.

[0064] Four guide posts 303 can be provided, and they can be located at the four corners of the base plate 301 respectively. Correspondingly, four guide holes 304 are provided.

[0065] In this embodiment, the first limiting structure 5 can be implemented in any appropriate form. As a specific implementation, the first limiting structure 5 includes at least two support protrusions 501, which are respectively disposed on both sides of the support frame 2, and the two support protrusions 501 partially overlap with the base plate 301 in the first direction.

[0066] Specifically, at least a portion of the support protrusions 501 are located on the travel path of the base plate 301 moving in the first direction, such that when the lower end face of the base plate 301 can abut against the top of the support protrusions 501, the support protrusions 501 provide support to the base plate 301 in the first direction, thereby limiting the initial position of the base plate 301.

[0067] The distance from the top of the support protrusion 501 to the bottom surface of the test channel 4 is the same as the distance from the bottom surface of the base plate 301 to the top of the ejector pin 302, so that when the base plate 301 comes into contact with the top of the support protrusion 501, the top of the ejector pin 302 can be flush with the bottom surface of the test channel 4.

[0068] In this embodiment, the support protrusion 501 can be integrally formed with the support frame 2, for example, by forming opposing protrusions on both sides of the support frame 2. Of course, the support protrusion 501 can also be made of a strip plate, which can be fixedly connected to the support frame 2 by screws.

[0069] In this embodiment, reference Figure 4 A second limiting structure 6 is also formed on the support frame 2, and the second limiting structure 6 is disposed below the first mold 101. The base plate 301 and the second limiting structure 6 are spaced apart in the first direction, and the second limiting structure 6 is located above the base plate 301.

[0070] The second limiting structure 6 partially overlaps with the base plate 301 in the first direction. That is, the second limiting structure 6 is partially located on the path of the base plate 301 moving in the first direction, so that when the base plate 301 moves upward to a predetermined height, the upper end surface of the base plate 301 can abut against the second limiting structure 6 to limit the upward stroke of the base plate 301.

[0071] In one embodiment, the support frame 2 includes two support strip plates 201, which are arranged opposite to each other. At least one support strip plate 201 has a fixed shaft 202 at its top end. The first mold 101 has a fixed hole 1011. The fixed shaft 202 is configured to extend along a first direction and is inserted into the fixed hole 1011 to form a plug-in fit.

[0072] Further, refer to Figure 4 The fixed shaft 202 may have a region located between the two support strips 201, and this region overlaps with the base plate 301 in the first direction to form the second limiting structure 6 described above.

[0073] In one embodiment, reference Figure 1 The first mold 101 has a first cold runner 105 located below the test runner 4. Coolant is introduced into the first cold runner 105 to regulate the temperature of the first mold 101 and its corresponding test runner 4 area, so that the test runner 4 is always maintained within a temperature range close to that of the actual die-casting mold during the test, thereby simulating the cooling and solidification environment of molten metal under real die-casting conditions.

[0074] Furthermore, multiple first cold runners 105 can be provided, with the multiple first cold runners 105 distributed at intervals. Second cold runners 106 can also be provided on the second mold 102, and multiple second cold runners 106 can also be provided, for applying cooling effect to the test runner 4 in both vertical and horizontal directions at the same time, so as to further approximate the double-wall heat dissipation conditions of the actual die-casting mold.

[0075] In this embodiment, both the first cold runner 105 and the second cold runner 106 can be formed by through holes penetrating the mold body. These through holes can be designed as straight or curved structures. Of course, the second cold runner 106 can be selected with a different structure than the first cold runner 105 to adapt to different mold structure layout requirements. Therefore, this embodiment achieves continuous heat exchange on the mold through the continuous flow of coolant, thereby enabling the test runner 4 to form a stable and adjustable temperature field during the test. This provides thermal boundary conditions closer to actual die casting for the molten metal flow test, thereby improving the reliability and reproducibility of the test results.

[0076] The first cold flow channel 105 and the second cold flow channel 106 can form a coolant circulation system with an external cooling water tank and circulating water pump.

[0077] In this embodiment, the temperature around the test flow channel 4 of the first mold 101 can also be monitored in real time using a temperature sensor.

[0078] In this embodiment, the first mold 101 and the second mold 102 can be connected by snap-fit ​​or other suitable connection methods, such as positioning pins, to realize the installation and positioning of the first mold 101 and the second mold 102, thereby avoiding horizontal displacement between the first mold 101 and the second mold 102.

[0079] In this embodiment, the first mold 101, the second mold 102, and the ejector pin 302 can all be made of H13 hot work die steel.

[0080] Secondly, this embodiment also provides a die-casting simulation method, which includes using the die-casting simulation device described above.

[0081] AZ91D heat-free magnesium alloy was used as the test object to evaluate its fluidity. Based on the die-casting process characteristics of AZ91D magnesium alloy, the recommended die-casting temperature is 720–740℃, and the injection speed is 1.5–2.5 m / s. In this embodiment, the following test parameters were set: The injection temperature is 730℃; the injection speed is 2.0m / s; the clamping force is 100MPa; the mold preheating temperature is 220℃, heated by a mold heating rod, and the preheating time is 30 minutes; the cooling water flow rate is 10L / min, and the cooling water temperature is 25℃.

[0082] Before simulation, the test mold should be cleaned, with a focus on removing residual metal slag and impurities from the upper mold runner cavity and the ejector pin 302 hole in the lower mold, in order to avoid interfering with the test results.

[0083] Then, the first mold 101 and the second mold 102 are heated together to 220°C, and the temperature changes are monitored in real time by a temperature sensor. After the temperature stabilizes, the temperature is kept warm for another 10 minutes to form a stable and uniform temperature field inside the mold.

[0084] Simultaneously, AZ91D magnesium alloy raw material was added to a crucible furnace, and a protective gas mixture of hydrogen sulfide (H2) and SF6 was introduced. The melt temperature was raised to 730°C at a heating rate of 10°C / min. After the alloy was completely melted, slag removal was performed, followed by stirring at 60 rpm for 5 minutes to remove impurities and dissolved gases from the melt. After stirring was stopped, the mixture was allowed to stand for 8 minutes for degassing to ensure that the hydrogen content in the melt did not exceed 0.15 mL / 100g, thereby improving the purity and stability of the melt.

[0085] Subsequently, the pressure unit, injection unit, cooling system, and data acquisition system were started in sequence to conduct system debugging on the mold closing action, the running accuracy of the injection rod, the cooling water circulation status, and the working status of the sensors.

[0086] Among these measures, it was confirmed that the cavity clearance after mold closing was no greater than 0.03mm, the coaxiality of the injection rod and the injection channel was no greater than 0.03mm, the temperature of the cooling water in the test channel 4 was stabilized within the range of 25±2℃ after circulating through the mold's cold runner, and the calibration of the pressure sensor and temperature sensor was completed.

[0087] Then the infill testing phase begins: The pressure application unit is activated, causing the first mold 101 and the second mold 102 to fit tightly together under a clamping force of 100 MPa, thus completing the mold closing operation. Then, the crucible furnace outlet valve is opened, allowing the molten AZ91D magnesium alloy to flow into the injection cylinder of the injection unit. The injection unit is then activated, and driven by a servo motor, the injection rod injects the molten magnesium alloy into the test flow channel 4 through the inlet 103 at a speed of 2.0 m / s into the injection port 103.

[0088] The data acquisition system is triggered at the same time the molten metal enters the flow channel to collect and record in real time the time from the molten metal entering the gate to the end of filling, the pressure change curves at the end of the main channel and the thin-walled area of ​​the branch, the temperature change at different locations in the cavity, and the displacement curve of the injection rod.

[0089] The recorded time data is used to characterize the overall filling speed of the molten metal; the pressure curve reflects the flow resistance and energy loss of the melt in the complex flow channel; the temperature curve is used to analyze the cooling behavior of the molten metal during the filling process; and the displacement of the injection rod can be used to reflect the progress of the melt in the cavity.

[0090] Then comes the demolding and data processing stage: After the data showed that the molten metal stopped flowing, the pressure was maintained for 10 seconds to simulate the pressure holding stage in the actual die-casting process. Then, the injection system was shut down and the cooling system was activated to enhance cooling, increasing the cooling water flow rate to 15 L / min to accelerate the solidification process. When the temperature data showed that the cavity wall temperature had dropped below 30°C, the tested magnesium alloy sample had completely solidified.

[0091] Then, the demolding structure 3 is activated, and the hydraulic push rod at the bottom of the mold frame pushes the ejector pin 302 fixing plate upward, so that 40 ejector pins 302 simultaneously extend into the test flow channel 4, ejecting the S-shaped sample as a whole.

[0092] After removing the sample, the filling length of the sample was measured along the center line of test channel 4 using vernier calipers, with a measurement accuracy of 1 mm. In this embodiment, the measured filling length was 3430 mm. Visual inspection of the sample surface revealed no under-casting or cold shut defects, only tiny pores with a diameter not exceeding 0.5 mm at local corners, meeting the die-casting quality requirements.

[0093] Based on the pressure and temperature curves recorded by the data acquisition system, the pressure at the end of the main channel decreased from 12 MPa to 8 MPa during the filling process, with a pressure loss of 4 MPa. The maximum local temperature drop in test channel 4 was 35°C. Therefore, it is concluded that the AZ91D magnesium alloy exhibits good fluidity under the set operating conditions.

[0094] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A die-casting simulation device, characterized in that, include: A test flow channel module (1) includes a first mold (101) and a second mold (102) stacked along a first direction. The first mold (101) has a test flow channel (4) on its surface facing the second mold (102). The test flow channel module (1) also includes a liquid inlet (103). The test flow channel module (1) is also provided with an air outlet (104) and a liquid inlet (103). The test flow channel (4) is connected to the air outlet (104) and the liquid inlet (103). The portion of the test flow channel (4) located between the air outlet (104) and the liquid inlet (103) is provided with multiple semi-circular arc segments (402). The liquid inlet (103) is connected to the end of the test channel (4). The test channel module (1) is also provided with an air outlet (104). The test channel (4) is constructed to extend from the liquid inlet (103) through multiple meandering bends to the air outlet (104) and is connected to the air outlet (104). The pressure application unit has its pressure output end abutting against the surface of the second mold (102) away from the first mold (101) and is capable of applying a preset pressure to the second mold (102); An injection unit is connected to the liquid inlet (103) and is configured to inject molten metal into the liquid inlet (103) at a preset flow rate.

2. The die-casting simulation device according to claim 1, characterized in that, The die-casting simulation device also includes a support frame (2), on which the first mold (101) is supported. The die-casting simulation device also includes a demolding structure (3), which is connected to the support frame (2) and located below the first mold (101). A portion of the demolding structure (3) passes through the first mold (101) and extends into the test flow channel (4). The demolding structure (3) is configured to be movable relative to the support frame (2) in a first direction.

3. The die-casting simulation device according to claim 2, characterized in that, The demolding structure (3) includes a base plate (301) and a plurality of ejector pins (302) mounted on the base plate (301). The base plate (301) is spaced apart from the first mold (101) along a first direction and is located below the first mold (101). Along the first direction, the base plate (301) is slidably connected to the support frame (2), and a plurality of ejector pins (302) extend toward the first mold (101). The top ends of the plurality of ejector pins (302) pass through the first mold (101) and extend into the test channel (4). During the liquid injection stage of the test channel (4), the top ends of the ejector pins (302) are flush with the inner bottom surface of the test channel (4).

4. The die-casting simulation device according to claim 3, characterized in that, The test channel (4) includes: Multiple straight segments (401) and multiple semi-circular arc segments (402) are sequentially and alternately connected to form the serpentine test channel (4). The ejector pins (302) are provided in three sets. The three sets of ejector pins (302) are arranged at intervals along the direction of two consecutive semi-circular arc segments (402) of the test channel (4). The top ends of the two sets of ejector pins (302) located on both sides extend into the semi-circular arc segments (402) located on both sides of the test channel (4), and the top end of the ejector pin (302) located in the middle set extends into the straight segment (401).

5. The die-casting simulation device according to claim 3, characterized in that, A first limiting structure (5) is formed on the support frame (2). The first limiting structure (5) is spaced apart from the first mold (101) along the first direction and is located below the base plate (301). When the ejector pin (302) is set to abut against the first limiting structure (5), the top of the ejector pin (302) is flush with the inner bottom surface of the test flow channel (4).

6. The die-casting simulation device according to claim 5, characterized in that, The first limiting structure (5) includes at least two support protrusions (501), which are respectively disposed on both sides of the support frame (2), and the two support protrusions (501) can support the base plate (301).

7. The die-casting simulation device according to claim 3, characterized in that, The support frame (2) has a second limiting structure (6) formed on it. The second limiting structure (6) is located below the first mold (101). The base plate (301) is set to be spaced apart from the second limiting structure (6) along a first direction. The base plate (301) is set to move a preset distance toward the first mold (101) along the first direction. The base plate (301) can abut against the second limiting structure (6).

8. The die-casting simulation device according to claim 3, characterized in that, The base plate (301) is also provided with a guide post (303), the guide post (303) extends along the first direction, and the first mold (101) is provided with a guide hole (304) accordingly, and the guide post (303) is slidably connected to the guide hole (304).

9. The die-casting simulation apparatus according to any one of claims 2-8, characterized in that, The support frame (2) includes two support strip plates (201), which are arranged opposite to each other. At least one of the support strip plates (201) has a fixed shaft (202) at its top end. The first mold (101) has a fixed hole (1011). The fixed shaft (202) is arranged to extend along a first direction and is inserted into the fixed hole (1011).

10. The die-casting simulation device according to claim 1, characterized in that, The first mold (101) has a first cold runner (105) which is located below the test runner (4) and coolant flows through the first cold runner (105).

11. The die-casting simulation device according to claim 1, characterized in that, The second mold (102) is provided with a second cold runner (106), which is spaced apart from the first cold runner (105) on the first mold (101), and coolant flows in the second cold runner (106).

12. The die-casting simulation device according to claim 1, characterized in that, The preset pressure includes 50-150 MPa; and / or, The preset flow rate includes 0.5-5 m / s; and / or, The test channel (4) has a trapezoidal cross-section, and the bottom face of the test channel (4) forms the short parallel side of the trapezoid.

13. A die-casting simulation method, characterized in that, This includes the die-casting simulation apparatus described in any one of claims 1-12.

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