An electrically assisted die-casting special device

Abstract

This invention provides an electric-assisted die-casting equipment that addresses phenomena such as turbulent molten metal flow, gas entrapment, and dendrite growth that affect the quality and performance of castings. It designs corresponding electromagnetic pretreatment before die-casting and an electric treatment component that can promote the filling and solidification processes. While effectively improving the microstructure of the metal material, it can also achieve temperature field uniformity of the casting, thereby significantly improving the forming quality and precision. Compared with the prior art, it also has a good cost advantage.

Description

Technical Field

[0001] This invention belongs to the technical field of metal die casting process equipment, specifically relating to a special equipment that uses an electric auxiliary method to improve the die casting effect and casting performance. Background Technology

[0002] During die casting, turbulence and air entrapment generated by the molten metal flow can easily lead to forming defects. Existing technologies mostly address these issues passively, such as optimizing the casting system and slowing down or adjusting the injection speed curve. While some forming defects and microstructure properties can be improved through in-mold cooling and subsequent heat treatment, these methods suffer from low control precision and inconsistent results, and can even introduce new defects like casting deformation and blistering. Regarding equipment costs, many existing technologies rely on increasing pressure to compensate for casting performance, leading to an over-reliance on high-tonnage, high-cost die casting equipment and resulting in unfavorable long-term economic prospects. Summary of the Invention

[0003] In view of the above, and in response to the technical problems existing in this field, the present invention provides an electric assisted die casting equipment, including: a die casting machine, a fixed mold, a barrel, an injection punch, a moving mold, a cavity, a through-type direct pulse current processing subsystem, and a barrel electromagnetic current stabilization and pretreatment subsystem;

[0004] The fixed mold, barrel, injection punch, and moving mold are all mounted on the die-casting machine; the cavity is opened on the moving mold, and several cavity peripheral electrode access points are distributed on its outer periphery; the injection punch is equipped with injection punch electrode access points.

[0005] The electromagnetic current stabilization and pretreatment subsystem of the barrel is electrically connected to the barrel to generate a pulsed magnetic field inside the barrel, so as to induce eddy currents inside the molten metal in the barrel, thereby stabilizing the liquid surface, removing impurities and refining the grains.

[0006] A through-type direct pulse current processing subsystem, an injection punch electrode access point, and a cavity outer peripheral electrode access point are sequentially connected to form a conductive circuit, which is used to apply pulse current to the molten metal or casting in the cavity to promote the filling and solidification process of the molten metal and the overall temperature field balance of the molten metal or casting.

[0007] Furthermore, the barrel electromagnetic current stabilization and pretreatment subsystem specifically consists of a first pulse power supply, an electromagnetic coil, electrode access points of the barrel electromagnetic current stabilization and pretreatment subsystem, an inner insulation layer of the barrel, wires, and an outer insulation layer of the barrel; wherein, the electromagnetic coil is wound on the outer wall of the barrel, and is electrically connected to the first pulse power supply through the electrode access points of the barrel electromagnetic current stabilization and pretreatment subsystem and the wires, and can generate a pulsed magnetic field inside the barrel under the drive of the first pulse power supply.

[0008] Furthermore, the through-type direct pulse current processing subsystem specifically includes a second pulse power supply and wires. The injection punch electrode access point is connected to the positive terminal of the second pulse power supply through the wires, and the access points of the outer peripheral electrodes of each cavity are connected to the negative terminal of the second pulse power supply through the wires. Driven by the second pulse power supply, the current flows sequentially through the positive terminal of the power supply, the injection punch electrode access point, the casting stalk, the access points of the outer peripheral electrodes of each cavity, and the negative terminal of the power supply.

[0009] Furthermore, a slidable push rod conductive slip ring is provided on the injection punch push rod to enable the injection punch electrode access point to form an electrical connection with the external first pulse power supply through the injection punch push rod and the wire.

[0010] Accordingly, the present invention also provides a pretreatment process method for die casting performed using the above-mentioned electrically assisted die casting equipment, specifically including the following steps:

[0011] Step 1: Pour the molten metal into the feed cylinder from the feed inlet;

[0012] Step 2: Start the electromagnetic current stabilization and pretreatment subsystem of the barrel to generate a magnetic field inside the barrel. By controlling the magnetic field, eddy currents are induced inside the molten metal. The interaction between the eddy currents and the magnetic field is used to suppress liquid surface fluctuations and turbulence and to remove impurities.

[0013] Step 3: Control the magnetic field and eddy currents to generate Joule heating and electromagnetic stirring effects inside the molten metal, thereby compensating for heat loss and refining grain size in the molten metal.

[0014] Step 4: Shut down the electromagnetic current stabilization and pretreatment subsystem of the barrel and prepare to perform the injection step.

[0015] Accordingly, the present invention also provides a die-casting filling and solidification acceleration process method performed using the above-mentioned electrically assisted die-casting equipment, specifically including the following steps:

[0016] Step 1: Simultaneously with the start of the injection process, activate the through-type direct pulse current processing subsystem to allow the pulse current to flow from the injection punch into the molten metal and out from the electrode access point on the outer periphery of the mold cavity that is in contact with the outer periphery of the molten metal. Maintain continuous energization throughout the filling process and the subsequent solidification process to optimize the depth structure of the casting.

[0017] Step 2: After solidification is complete, shut down the through-type direct pulse current processing subsystem, and the die-casting machine opens the mold to eject the finished casting.

[0018] Furthermore, the die-casting filling and solidification promotion process also includes selective heating of local low-temperature areas of the molten metal or casting by a through-type direct pulse current treatment subsystem in conjunction with some outer peripheral electrodes of the cavity, in order to achieve overall temperature field balance of the molten metal or casting, reduce shrinkage porosity and eliminate cold shuts.

[0019] The electric-assisted die-casting equipment provided by the present invention addresses phenomena such as turbulent flow of molten metal, gas entrapment, and dendrite growth that affect the quality and performance of castings. It designs corresponding electromagnetic pretreatment before die-casting and DC power-on treatment components that can promote the filling and solidification processes. While effectively improving the microstructure of metal materials, it can also achieve temperature field uniformity of castings, thereby significantly improving forming quality and precision. Compared with the prior art, it also has a good cost advantage. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the electric-assisted die-casting equipment provided by the present invention;

[0021] Figure 2 A schematic diagram of an optional structure for the electromagnetic current stabilization and pretreatment subsystem of the material barrel;

[0022] Figure 3 This is a schematic diagram of an optional structure for a through-type direct pulse current processing subsystem. Detailed Implementation

[0023] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The electric-assisted die-casting equipment provided by this invention, such as Figure 1-3 As shown, it includes: a die-casting machine 1, a fixed mold 2, a barrel 3, an injection punch 4, a moving mold 5, a cavity 6, a through-type direct pulse current processing subsystem 9, and a barrel electromagnetic current stabilization and pretreatment subsystem 10.

[0025] Among them, the fixed mold 2, the barrel 3, the injection punch 4 and the moving mold 5 are all set on the die casting machine 1; the cavity 6 is opened on the moving mold 5, and several cavity outer peripheral electrode access points are distributed on its outer periphery; the injection punch 4 is provided with injection punch electrode access points;

[0026] The electromagnetic flow stabilization and pretreatment subsystem 10 of the barrel is electrically connected to the barrel 3. It is used to generate a pulsed magnetic field inside the barrel, which induces eddy currents inside the molten metal to suppress surface fluctuations and turbulence, rapidly transforming it into a stable laminar flow, thereby allowing the entrained gas to rise and be discharged. The eddy currents also bring about Joule heating and electromagnetic stirring effects. The former can compensate for the heat loss of the molten metal and maintain its superheat, while the latter can break up the initially formed crystal nuclei, increase the nucleation rate, and achieve grain refinement pretreatment of the molten metal, preparing it for subsequent solidification.

[0027] A conductive circuit is formed by sequentially connecting the through-type direct pulse current processing subsystem 9, the injection punch electrode access point, and the cavity peripheral electrode access point. Through this conductive circuit, the through-type direct pulse current processing subsystem 9 can apply a pulse current to the molten metal or casting within the cavity, allowing the current to penetrate the center and periphery of the molten metal or casting. This generates an electroplastic effect, reducing the bonding force between liquid / solid phase atoms, thereby improving the fluidity and filling capacity of the molten metal. Simultaneously, the skin effect and electromagnetic contraction effect of the pulse current can violently disturb the solid-liquid interface, effectively breaking up growing dendrites and forming new nucleation sites, thus effectively eliminating flow blockage and achieving deep and comprehensive grain refinement and microstructure homogenization. Furthermore, the Joule heating effect can be used at different locations on the cavity peripheral electrode access points to heat locally colder areas of the casting, balancing the temperature field of the entire casting to reduce shrinkage porosity and eliminate cold shuts.

[0028] In a preferred embodiment of the present invention, the barrel electromagnetic current stabilization and pretreatment subsystem 10 specifically comprises a first pulse power supply, an electromagnetic coil 21, an electrode access point 28 for the barrel electromagnetic current stabilization and pretreatment subsystem, an inner insulating layer 23 in the barrel, wires, and outer insulating layers 18 and 19 in the barrel. The electromagnetic coil 21 is wound around the outer wall of the barrel 3 and is electrically connected to the first pulse power supply through the electrode access point 28 and the wires, enabling it to generate a pulsed magnetic field within the barrel 3 under the drive of the first pulse power supply. Depending on actual needs, a magnetic core can be provided in the barrel to obtain a more enhanced and concentrated magnetic field, or a corresponding excitation layer 22 can be provided inside the electromagnetic coil 21. A barrel outer shell 20 can be provided outside the barrel for protection.

[0029] In a preferred embodiment of the present invention, the through-type direct pulse current processing subsystem 9 specifically includes a second pulse power supply and wires. The injection punch electrode access point is connected to the positive terminal of the second pulse power supply via wire 16, and the outer peripheral electrode access points 71, 72, 73, 74, and 75 of each cavity are connected to the negative terminal of the second pulse power supply via wire 15. Driven by the second pulse power supply, the current flows sequentially through the positive terminal of the power supply, the injection punch electrode access point, the casting stalk 17, the outer peripheral electrode access points of each cavity, and the negative terminal of the power supply.

[0030] In a preferred embodiment of the present invention, a slidable push rod conductive slip ring is provided on the injection punch push rod, which is used to make the injection punch electrode access point electrically connected to the external first pulse power supply through the injection punch push rod and the wire.

[0031] Accordingly, the present invention also provides a pretreatment process method for die casting performed using the above-mentioned electrically assisted die casting equipment, specifically including the following steps:

[0032] Step 1: Pour the molten metal into the feed cylinder from the feed inlet;

[0033] Step 2: Start the electromagnetic current stabilization and pretreatment subsystem of the barrel to generate a magnetic field inside the barrel. By controlling the magnetic field, eddy currents are induced inside the molten metal. The interaction between the eddy currents and the magnetic field is used to suppress liquid surface fluctuations and turbulence and to remove impurities.

[0034] Step 3: Control the magnetic field and eddy currents to generate Joule heating and electromagnetic stirring effects inside the molten metal, thereby compensating for heat loss and refining grain size in the molten metal.

[0035] Step 4: Shut down the electromagnetic current stabilization and pretreatment subsystem of the barrel and prepare to perform the injection step.

[0036] Accordingly, the present invention also provides a die-casting filling and solidification acceleration process method performed using the above-mentioned electrically assisted die-casting equipment, specifically including the following steps:

[0037] Step 1: Simultaneously with the start of the injection process, activate the through-type direct pulse current processing subsystem to allow the pulse current to flow from the injection punch into the molten metal and out from the electrode access point on the outer periphery of the mold cavity that is in contact with the outer periphery of the molten metal. Maintain continuous energization throughout the filling process and the subsequent solidification process to optimize the depth structure of the casting.

[0038] Step 2: After solidification is complete, shut down the through-type direct pulse current processing subsystem, and the die-casting machine opens the mold to eject the finished casting.

[0039] In a preferred embodiment of the present invention, the die casting filling and solidification promotion process further includes selectively heating the local low-temperature areas of the molten metal or casting by a through-type direct pulse current treatment subsystem in conjunction with some of the outer peripheral electrodes of the cavity, so as to achieve overall temperature field balance of the molten metal or casting, reduce shrinkage porosity and eliminate cold shuts.

[0040] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] It should be understood that the sequence number of each step in the embodiments of the present invention does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A special equipment for electric-assisted die casting, characterized in that: include: Die casting machine, fixed mold, barrel, injection punch, moving mold, cavity, through-type direct pulse current processing subsystem, and barrel electromagnetic current stabilization and pretreatment subsystem; The fixed mold, barrel, injection punch, and moving mold are all mounted on the die-casting machine; the cavity is opened on the moving mold, and several cavity peripheral electrode access points are distributed on its outer periphery; the injection punch is equipped with injection punch electrode access points. The electromagnetic current stabilization and pretreatment subsystem of the barrel is electrically connected to the barrel to generate a pulsed magnetic field inside the barrel, so as to induce eddy currents inside the molten metal in the barrel, thereby stabilizing the liquid surface, removing impurities and refining the grains. A through-type direct pulse current processing subsystem, an injection punch electrode access point, and a cavity outer peripheral electrode access point are sequentially connected to form a conductive circuit, which is used to apply pulse current to the molten metal or casting in the cavity to promote the filling and solidification process of the molten metal and the overall temperature field balance of the molten metal or casting.

2. The electric-assisted die-casting equipment as described in claim 1, characterized in that: The barrel electromagnetic current stabilization and pretreatment subsystem specifically consists of a first pulse power supply, an electromagnetic coil, electrode access points of the barrel electromagnetic current stabilization and pretreatment subsystem, an inner insulation layer of the barrel, wires, and an outer insulation layer of the barrel. The electromagnetic coil is wound around the outer wall of the barrel and is electrically connected to the first pulse power supply through the electrode access points of the barrel electromagnetic current stabilization and pretreatment subsystem and the wires. It can generate a pulsed magnetic field inside the barrel under the drive of the first pulse power supply.

3. The electric-assisted die-casting equipment as described in claim 1, characterized in that: The through-type direct pulse current processing subsystem specifically includes a second pulse power supply and wires. The injection punch electrode access point is connected to the positive terminal of the second pulse power supply through the wires, and the access points of the outer peripheral electrodes of each cavity are connected to the negative terminal of the second pulse power supply through the wires. Driven by the second pulse power supply, the current flows sequentially through the positive terminal of the power supply, the injection punch electrode access point, the casting stalk, the access points of the outer peripheral electrodes of each cavity, and the negative terminal of the power supply.

4. The electric-assisted die-casting equipment as described in claim 3, characterized in that: A sliding conductive slip ring is provided on the injection punch push rod to enable the injection punch electrode access point to form an electrical connection with the external first pulse power supply through the injection punch push rod and the wire.

5. A pre-treatment process for die casting performed using the equipment described in any one of claims 1-4, characterized in that: Specifically, the following steps are included: Step 1: Pour the molten metal into the feed cylinder from the feed inlet; Step 2: Start the electromagnetic current stabilization and pretreatment subsystem of the barrel to generate a magnetic field inside the barrel. By controlling the magnetic field, eddy currents are induced inside the molten metal. The interaction between the eddy currents and the magnetic field is used to suppress liquid surface fluctuations and turbulence and to remove impurities. Step 3: Control the magnetic field and eddy currents to generate Joule heating and electromagnetic stirring effects inside the molten metal, thereby compensating for heat loss and refining grain size in the molten metal. Step 4: Shut down the electromagnetic current stabilization and pretreatment subsystem of the barrel and prepare to perform the injection step.

6. A die-casting filling and solidification acceleration process performed using the equipment described in any one of claims 1-4, characterized in that: Specifically, the following steps are included: Step 1: Simultaneously with the start of the injection process, activate the through-type direct pulse current processing subsystem to allow the pulse current to flow from the injection punch into the molten metal and out from the electrode access point on the outer periphery of the mold cavity that is in contact with the outer periphery of the molten metal. Maintain continuous energization throughout the filling process and the subsequent solidification process to optimize the depth structure of the casting. Step 2: After solidification is complete, shut down the through-type direct pulse current processing subsystem, and the die-casting machine opens the mold to eject the finished casting.

7. The method as described in claim 6, characterized in that: The filling and solidification promotion process in die casting also includes selective heating of local low-temperature areas of the molten metal or casting by a through-type direct pulse current treatment subsystem in conjunction with some peripheral electrodes of the cavity, in order to achieve overall temperature field balance of the molten metal or casting, reduce shrinkage porosity and eliminate cold shuts.

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