Sprue device, control method thereof and semi-solid injection molding equipment

Abstract

The invention discloses a pouring gate device, a control method thereof and semi-solid injection molding equipment, and relates to the technical field of semi-solid injection molding, the pouring gate device comprises an induction heating assembly and a nozzle, when the induction heating assembly receives a production signal, the outlet end area of the nozzle is heated to a first preset heat preservation temperature range at a first preset heating rate; the cold plug is semi-solidified to block the nozzle; when a mold closing signal is received, the temperature is increased to a higher second preset heat preservation temperature range at a higher second preset heating rate, the cold plug is melted, and an injection signal is output; after the injection completion signal is received, the temperature is reduced to the first preset heat preservation temperature range at the preset cooling rate for heat preservation, and a mold opening signal is output; the state of the cold plug can be accurately regulated and controlled, the problems that in semi-solid magnesium alloy injection molding, the discharge pressure of the cold plug is high, the filling pressure loss of a product in a cavity is large, material leakage is likely to happen to the nozzle connecting position, and the cold plug is difficult to form before mold opening are solved, and the pressure stability in the filling process and the product quality are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semi-solid injection molding, and particularly relates to a sprue device, a control method thereof and a semi-solid injection molding equipment. BACKGROUND

[0002] The principle of semi-solid magnesium alloy injection molding is to add magnesium particles into a cylinder, and to make the magnesium alloy particles into a semi-solid state through rotation of a screw and heating of an outer wall of the cylinder. Then, pressure oil is introduced into an injection cylinder to push the screw forward, so that the melt is injected into a closed mold at a high pressure and a very fast speed. After pressure maintaining and cooling, the product is solidified and molded, and then the mold is opened to take out the product.

[0003] During the injection process of the next mold, the screw is pushed forward to first push out a cold plug at the nozzle outlet end and close to the inlet of the mold main flow channel at a high speed. The cold plug is a low-temperature solid formed by natural solidification at the nozzle outlet end and the inlet of the mold main flow channel during the cooling stage of the previous mold. When the screw applies an injection pressure, the cold plug is pushed by the semi-solid magnesium alloy slurry in front, enters the mold flow channel along the nozzle outlet end, and is quickly discharged to the front end of the mold cavity, the end of the flow channel or the cold plug catcher through the sprue channel. Only after the cold plug is completely pushed out, the subsequent slurry with suitable temperature and flowability can smoothly pass through the nozzle outlet end, enter the cavity through the sprue, and complete the filling of the entire mold cavity. This process requires that the cold plug must be removed in time, otherwise it will hinder the flow of the slurry, increase the filling resistance, and further cause molding defects such as cold plug, material shortage or shrinkage.

[0004] In order to maintain the temperature of the slurry in the nozzle matched with the single-sprue or multi-sprue mold, the outer wall of the conventional nozzle is heated by resistance wire to maintain the temperature. However, due to the surface load capacity of the resistance wire and the contact area between the resistance wire and the outer wall of the nozzle, the resistance wire heating can only maintain the basic temperature of the magnesium alloy slurry in the nozzle, and cannot quickly heat the nozzle outlet end to melt the formed cold plug in a very short time.

[0005] The conventional semi-solid magnesium alloy injection molding is usually produced by using AZ91D and AM60B magnesium alloys. These two alloys have a wide semi-solid temperature interval of 125 degrees Celsius and 75 degrees Celsius respectively, and are easy to form and stably control the cold plug state at the nozzle outlet end. However, the new type of magnesium alloy with special high strength, high toughness and high thermal conductivity usually has a narrow semi-solid temperature interval of about 30 to 50 degrees Celsius, which is difficult to accurately regulate and control the cold plug state by resistance wire heating, resulting in that the molten magnesium alloy slurry in the nozzle is easy to flow out or splash from the end of the sprue when the mold is opened. SUMMARY

[0006] The main objective of this invention is to propose a gate device and its control method, as well as a semi-solid injection molding equipment, which aims to precisely control the cold plug state and solve the problems of high cold plug discharge pressure, large product filling pressure loss in the cavity, easy material leakage at the nozzle connection, and difficulty in forming a cold plug before mold opening in semi-solid magnesium alloy injection molding, thereby improving the stability of pressure during the filling process and the quality of the product.

[0007] To achieve the above objectives, the present invention proposes a control method for a gating device used in a semi-solid injection molding equipment. The gating device includes an induction heating assembly and a nozzle. The control method for the gating device includes: Upon receiving the production signal output by the semi-solid injection molding equipment, the induction heating component is controlled to adjust the temperature of the area where the nozzle outlet end is located to the range of the first preset heat preservation temperature at the first preset heating rate, so that the cold plug in the outlet end is in a semi-solid state to seal the nozzle. Upon receiving the mold closing signal output by the semi-solid injection molding equipment, the induction heating component is controlled to adjust the temperature of the area where the nozzle outlet end is located to the range of the second preset heat preservation temperature at the second preset heating rate, so that the cold plug in the outlet end turns into a molten state, and an injection signal is output to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform the injection action. Upon receiving the injection completion signal output by the semi-solid injection molding equipment, the induction heating component is controlled to adjust the temperature of the area where the nozzle outlet is located to the first preset heat preservation temperature range at a preset cooling rate, and outputs a mold opening signal to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform the mold opening action. Wherein, the first preset heating rate is less than the second preset heating rate, and the preset cooling rate is less than the second preset heating rate; The first preset insulation temperature range is smaller than the second preset insulation temperature range.

[0008] In one embodiment, the first preset heating rate is not less than 0.5℃ / s and not greater than 2℃ / s; the first preset heat preservation temperature range is not less than 450℃ and not greater than 650℃; and / or The second preset heating rate is not less than 6℃ / s; the second preset heat preservation temperature range is not less than 470℃ and not greater than 670℃; and / or The preset cooling rate is not less than 1℃ / s.

[0009] In one embodiment, the induction heating assembly includes an induction coil and an induction heating circuit. The induction heating circuit includes a rectifier circuit and an inverter circuit. The input terminal of the inverter circuit is connected to the output terminal of the rectifier circuit, and the output terminal of the inverter circuit is connected to the input terminal of the induction coil. Upon receiving a production signal output by the semi-solid injection molding equipment, controlling the induction heating component to adjust the temperature of the area where the nozzle exit end is located to a first preset heat preservation temperature range at a first preset heating rate, so that the cold plug in the exit end is in a semi-solid state to seal the nozzle, includes: Upon receiving the production signal output by the semi-solid injection molding equipment, the induction coil is controlled to heat the area where the nozzle outlet end is located at the first preset heating rate; Obtain the temperature of the area where the nozzle outlet is located; Based on the temperature of the area where the nozzle outlet is located, the DC voltage output from the rectifier circuit to the inverter circuit is adjusted so that the temperature of the area where the nozzle outlet is located is within the first preset insulation temperature range.

[0010] In one embodiment, adjusting the DC voltage output from the rectifier circuit to the inverter circuit based on the obtained temperature of the area where the nozzle outlet is located, so that the temperature of the area where the nozzle outlet is located is within the first preset insulation temperature range, includes: Based on the temperature of the area where the nozzle outlet is located, the trigger delay angle of the thyristor in the rectifier circuit is adjusted so that the DC voltage output from the rectifier circuit to the inverter circuit is within a first preset DC voltage range, and the temperature of the area where the nozzle outlet is located is within the first preset insulation temperature range.

[0011] In one embodiment, the induction heating assembly includes an induction coil and an induction heating circuit. The induction heating circuit includes a rectifier circuit and an inverter circuit. The input terminal of the inverter circuit is connected to the output terminal of the rectifier circuit, and the output terminal of the inverter circuit is connected to the input terminal of the induction coil. Upon receiving the mold closing signal output by the semi-solid injection molding equipment, controlling the induction heating component to adjust the temperature of the area where the nozzle exit end is located to a second preset heat preservation temperature range at a second preset heating rate, so that the cold plug in the exit end turns into a molten state, and outputting an injection signal to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform an injection action includes: Upon receiving the mold closing signal output by the semi-solid injection molding equipment, the induction coil is controlled to heat the area where the nozzle outlet end is located at the second preset heating rate; Obtain the temperature of the area where the nozzle outlet is located; Based on the temperature of the area where the nozzle outlet is located, the DC voltage output from the rectifier circuit to the inverter circuit is adjusted so that the temperature of the area where the nozzle outlet is located is within the second preset insulation temperature range. When the temperature in the area where the nozzle outlet is located is within the second preset heat preservation temperature range, an injection signal is output to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform an injection action.

[0012] In one embodiment, adjusting the DC voltage output from the rectifier circuit to the inverter circuit based on the obtained temperature of the area where the nozzle outlet is located, so that the temperature of the area where the nozzle outlet is located is within the second preset insulation temperature range, includes: Based on the temperature of the area where the nozzle outlet is located, the trigger delay angle of the thyristor in the rectifier circuit is adjusted so that the DC voltage output from the rectifier circuit to the inverter circuit is within the second preset DC voltage range, and the temperature of the area where the nozzle outlet is located is within the second preset insulation temperature range.

[0013] In one embodiment, the induction heating assembly includes an induction coil and an induction heating circuit. The induction heating circuit includes a rectifier circuit and an inverter circuit. The input terminal of the inverter circuit is connected to the output terminal of the rectifier circuit, and the output terminal of the inverter circuit is connected to the input terminal of the induction coil. Upon receiving the injection completion signal output by the semi-solid injection molding equipment, controlling the induction heating component to adjust the temperature of the area where the nozzle exit end is located to the first preset heat preservation temperature range at a preset cooling rate for heat preservation, and outputting a mold opening signal to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform the mold opening action includes: Upon receiving the injection completion signal output by the semi-solid injection molding equipment, the induction coil is controlled to heat the area where the nozzle outlet end is located at the preset cooling rate. Obtain the temperature of the area where the nozzle outlet is located; Based on the temperature of the area where the nozzle outlet is located, the DC voltage output from the rectifier circuit to the inverter circuit is adjusted so that the temperature of the area where the nozzle outlet is located is within the first preset insulation temperature range. When the temperature in the area where the nozzle outlet is located is within the first preset heat preservation temperature range, an opening signal is output to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform the opening action.

[0014] In one embodiment, adjusting the DC voltage output from the rectifier circuit to the inverter circuit based on the obtained temperature of the area where the nozzle outlet is located, so that the temperature of the area where the nozzle outlet is located is within the first preset insulation temperature range, includes: Based on the temperature of the area where the nozzle outlet is located, the trigger delay angle of the thyristor in the rectifier circuit is adjusted so that the DC voltage output from the rectifier circuit to the inverter circuit is within a first preset DC voltage range, and the temperature of the area where the nozzle outlet is located is within the first preset insulation temperature range.

[0015] The present invention also proposes a gating device for a semi-solid injection molding equipment, the gating device comprising: The nozzle has a flow channel for supplying slurry and an outlet end communicating with the flow channel, the outlet end being used to communicate with a mold cavity; A resistance heating element is disposed on the nozzle for heating the nozzle; An induction heating component is disposed at the outlet end and is used to heat the outlet end; A control component is electrically connected to the resistance heating element and the induction heating element, respectively. The control component includes a memory, a processor, and a control program for the gating device stored in the memory and executed by the processor. When the control program for the gating device is executed by the processor, it implements the control method for the gating device as described above.

[0016] In one embodiment, the induction heating assembly includes: An induction coil is wound around the outer periphery of the outlet end for heating the outlet end; An induction heating circuit includes a rectifier circuit and an inverter circuit, which are electrically connected to the control component. The rectifier circuit converts the input AC power into DC power and outputs it to the inverter circuit. The input terminal of the inverter circuit is connected to the output terminal of the rectifier circuit, and the output terminal of the inverter circuit is connected to the input terminal of the induction coil. The inverter circuit converts the DC power into high-frequency AC power and outputs it to the induction coil. The control component is further configured to adjust the DC voltage output from the rectifier circuit to the inverter circuit based on the temperature of the area where the outlet is located, so that the temperature of the area where the outlet is located is within a first preset heat preservation range or a second preset heat preservation range.

[0017] In one embodiment, the induction heating circuit further includes a filter circuit, the input terminal of which is connected to the output terminal of the rectifier circuit, and the output terminal of which is connected to the input terminal of the inverter circuit. The filter circuit is used to filter out the low-frequency ripple in the DC power output by the rectifier circuit before outputting it to the inverter circuit. And / or, the induction heating circuit further includes a resonant circuit, the input terminal of which is connected to the output terminal of the inverter circuit, and the output terminal of which is connected to the input terminal of the induction coil. The resonant circuit is used to compensate for the inductive reactive power of the induction coil.

[0018] In one embodiment, the gating device further includes a sprue for mounting on a mold, and the nozzle is disposed within the sprue; the induction coil is located between the inner peripheral wall of the sprue and the outer peripheral wall of the nozzle.

[0019] In one embodiment, the induction heating assembly further includes an insulating member that is wound around the outer periphery of the outlet end and located between the induction coil and the inlet, for isolating the induction coil from the inlet.

[0020] In one embodiment, the induction heating assembly further includes a coil housing disposed inside the inlet and wound around the outer periphery of the induction coil; the insulating member is disposed on the coil housing.

[0021] In one embodiment, the gate device further includes a cover plate and an adjusting ring. The cover plate is used to install the gate onto the mold, and the adjusting ring is disposed inside the gate and connected to the nozzle. The adjusting ring is used to compensate for concentricity deviations between the nozzle, the gate, and the cover plate.

[0022] The present invention also proposes a semi-solid injection molding device, including the gating device as described above.

[0023] The technical solution of this invention, by setting up an induction heating component and a nozzle, enables the gating device to, upon receiving a production signal from a semi-solid injection molding equipment, control the induction heating component to adjust the temperature of the nozzle outlet area to a first preset holding temperature range at a first preset heating rate, keeping the cold plug in a semi-solid state and effectively sealing the nozzle. Upon receiving a mold closing signal from the semi-solid injection molding equipment, the induction heating component is controlled to adjust the temperature of the nozzle outlet area to a second preset holding temperature range at a higher second preset heating rate, causing the cold plug to melt, thereby ensuring that the molten slurry in the nozzle can be smoothly injected into the mold cavity through the outlet. Employing staged and differentiated heating rates for thermal management allows for precise control of the cold plug's required state at different process stages. Because induction heating has the characteristics of fast response, high local heating efficiency, and high temperature control accuracy, compared to the limitations of traditional resistance wire heating which can only provide overall heat preservation and cannot quickly melt the cold plug, this invention solves the problem of difficulty in precisely controlling the cold plug state when using novel high-strength magnesium alloys with a narrow semi-solid temperature range. By increasing the temperature at the nozzle outlet before mold closing to melt the cold plug, it is possible to avoid increased filling resistance, poor flow, and molding defects such as cold shuts, material shortages, or shrinkage caused by cold plug residue. At the same time, keeping the cold plug in a semi-solid state during the production standby stage can also prevent high-temperature slurry from flowing out of the gate or splashing when the mold is opened, thereby improving process stability and molding quality. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0025] Figure 1 A schematic diagram of an embodiment of the control method for the gating device provided by the present invention; Figure 2 A schematic diagram of another embodiment of the control method for the gating device provided by the present invention; Figure 3 A schematic diagram of another embodiment of the control method for the gating device provided by the present invention; Figure 4 A schematic diagram of another embodiment of the control method for the gating device provided by the present invention; Figure 5 A schematic diagram of another embodiment of the control method for the gating device provided by the present invention; Figure 6A schematic diagram of another embodiment of the control method for the gating device provided by the present invention; Figure 7 A schematic diagram of another embodiment of the control method for the gating device provided by the present invention; Figure 8 This is a schematic diagram of an embodiment of the gating device provided by the present invention; Figure 9 This is a schematic diagram of the circuit functional modules of an embodiment of the gating device provided by the present invention; Figure 10 This is a schematic diagram of the circuit structure of an embodiment of the gating device provided by the present invention; Figure 11 This is a schematic diagram of another embodiment of the gating device provided by the present invention; Explanation of icon numbers: 100. Gating device; 10. Nozzle; 101. Flow channel; 1011. First flow channel; 1012. Second flow channel; 102. Outlet end; 1021. First outlet end; 1022. Second outlet end; 20. Resistance heating element; 21. First resistance heating element; 22. Second resistance heating element; 30. Induction heating assembly; 31. Induction coil; 311. First induction coil; 312. Second induction coil; 32. Induction heating circuit; 321. Rectifier circuit; 322. Inverter circuit; 323. Filter circuit; 324. Resonant circuit; 325. Isolation transformer circuit; 326. Protection circuit; 41. Control components; 42. Temperature sensing components; 50. Inlet; 51. First inlet; 52. Second inlet; 60. Insulating component; 61. First insulating component; 62. Second insulating component; 70. Coil housing; 71. First coil housing; 72. Second coil housing; 80. Cover plate; 81. First cover plate; 82. Second cover plate; 90. Adjusting ring; 91. First adjusting ring; 92. Second adjusting ring; 200. Cold plug; 300. Operation panel.

[0026] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] This invention proposes a control method for a gate device 100 used in semi-solid injection molding equipment. The aim is to precisely control the cold plug state and solve the problems of high cold plug discharge pressure, large product filling pressure loss in the cavity, easy material leakage at the nozzle connection, and difficulty in forming a cold plug before mold opening in semi-solid magnesium alloy injection molding. This improves the stability of pressure during the filling process and the quality of the product.

[0029] Please see Figure 1 , Figure 8 and Figure 9 In one embodiment of the present invention, the control method of the gating device 100 includes: S100. Upon receiving the production signal output by the semi-solid injection molding equipment, the induction heating component is controlled to adjust the temperature of the area where the nozzle outlet is located to the range of the first preset heat preservation temperature at the first preset heating rate, so that the cold plug in the outlet is in a semi-solid state to seal the nozzle. S200. Upon receiving the mold closing signal output by the semi-solid injection molding equipment, the induction heating component is controlled to adjust the temperature of the area where the nozzle exit end is located to the range of the second preset heat preservation temperature at the second preset heating rate, so that the cold plug in the exit end is transformed into a molten state, and an injection signal is output to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform the injection action. S300: Upon receiving the injection completion signal output by the semi-solid injection molding equipment, the induction heating component is controlled to adjust the temperature of the area where the nozzle outlet is located to the first preset heat preservation temperature range at a preset cooling rate, and a mold opening signal is output to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform the mold opening action; wherein, the first preset heating rate is less than the second preset heating rate, the preset cooling rate is less than the second preset heating rate, and the first preset heat preservation temperature range is less than the second preset heat preservation temperature range.

[0030] It is understood that semi-solid injection molding equipment is a type of equipment used to produce metal parts, and may include compression molding machines, die casting machines, injection molding machines, forging machines, stamping machines, or extrusion machines. This invention uses an injection molding machine as an example of semi-solid injection molding equipment. Injection molding machines inject molten metal into a mold cavity under high pressure, and after rapid cooling, form metal parts of the desired shape. They feature high production efficiency, good dimensional accuracy, and superior surface quality, and are widely used in the manufacturing of parts in the automotive, electronics, and home appliance industries.

[0031] The main components of an injection molding machine include a mold clamping mechanism, an injection mechanism, a hydraulic mechanism, a control mechanism, a cooling mechanism, and a mold. The mold clamping mechanism is responsible for opening and closing the mold, ensuring it remains tightly closed during injection to prevent molten metal leakage. The injection mechanism injects molten metal into the mold cavity at high speed. The hydraulic mechanism provides power for mold opening and closing and injection pressure supply. The control mechanism coordinates the timing of each component's actions to ensure automated operation of the molding process. The cooling mechanism regulates the mold temperature to prevent overheating from affecting product quality.

[0032] The injection mechanism may include a barrel, a screw, a heating module, an injection cylinder, and a gating device 100. The barrel is provided with a feed port for metal particles to enter, serving as a container for holding and initially plasticizing the metal particles. Its inner wall cooperates with the screw to achieve the conveying and shearing mixing of the metal particles. The screw not only performs the conveying function but also assists the metal particles to reach a semi-solid state through friction and shearing during rotation. During the injection stage, it is pushed axially by the injection cylinder. The heating module is arranged on the outer periphery of the barrel to supplement heat and maintain the overall temperature stability of the semi-solid slurry. The injection cylinder completes the injection stroke by hydraulically driving the screw. The gating device 100 includes a nozzle 10 and a gate 50. The nozzle 10 forms the last channel for the slurry to reach the mold. Its inlet end is connected to the outlet end of the barrel, and its outlet end 102 is directly connected to the main runner inlet of the mold, which can convert the semi-solid slurry output from the barrel into molten slurry before outputting it to the mold. The gate 50 is fixed on the mold, wrapping the nozzle 10 and providing a local heat preservation environment. At the same time, it serves as a structural support to ensure the sealing and alignment between the nozzle 10 and the mold.

[0033] This invention uses magnesium alloy particles as an example for illustration. During the actual operation of the injection molding machine, magnesium alloy particles are added into the barrel, and the particles become semi-solid due to the rotation of the screw and the heating of the barrel's outer wall. Then, pressurized oil is introduced into the injection cylinder, propelling the screw forward and injecting the molten slurry from the nozzle 10 into the cooler, closed mold at very high pressure and speed. After pressure holding and cooling, the slurry solidifies, and the mold can be opened to remove the product. In the next injection cycle, the screw advances forward, first ejecting the cold plug 200 located at the nozzle 10 outlet 102, adjacent to the mold's main runner inlet, at high speed. The cold plug 200 is a low-temperature solid formed by natural solidification at the nozzle 10 outlet 102 and the mold's main runner inlet during the cooling stage of the previous cycle.

[0034] When the screw applies injection pressure, the cold plug 200 is pushed by the semi-solid magnesium alloy slurry in front of it, enters the mold runner through the nozzle 10 outlet 102, and is quickly discharged through the gating channel to the front end of the mold cavity or the end of the runner. Only after the cold plug 200 is completely ejected can the subsequent molten slurry with suitable temperature and flowability smoothly enter the mold cavity through the nozzle 10 outlet 102 and the gating channel to complete the filling of the entire mold cavity. This process requires that the cold plug 200 must be removed in time; otherwise, it will hinder the flow of slurry, increase the filling resistance, and may cause molding defects such as cold shuts, material shortages, or shrinkage cavities.

[0035] To match single-gate or multi-gate molds, traditional nozzles use resistance wire heating for insulation on the outer wall. However, limited by the surface load capacity of the resistance wire and its contact area with the nozzle outer wall, resistance wire heating can only maintain the basic temperature of the magnesium alloy slurry inside the nozzle, and cannot rapidly heat the nozzle exit end to melt the formed cold plug in a very short time. Traditional semi-solid magnesium alloy injection molding often uses AZ91D and AM60B magnesium alloys for production. These two alloys have relatively wide semi-solid temperature ranges, 125 degrees Celsius and 75 degrees Celsius respectively, making it easy to form and stably control the cold plug state at the nozzle exit end. However, new magnesium alloys with special high strength, high toughness, and high thermal conductivity usually have a narrower semi-solid temperature range, approximately 30 to 50 degrees Celsius, making it difficult to precisely control the cold plug state using resistance wire heating. This causes the molten magnesium alloy slurry inside the nozzle to easily flow out or splash from the gate end when the mold opens.

[0036] The gating device 100 of this invention includes a nozzle 10, a resistance heating element 20, and an induction heating assembly 30. The nozzle 10 has a flow channel 101 for slurry flow, and an inlet end and an outlet end 102 communicating with the flow channel 101. The inlet end is connected to the barrel of the injection molding machine to receive semi-solid magnesium alloy slurry, and the outlet end 102 is connected to and connected to the main runner inlet of the mold. The mold has a main runner, a branch runner communicating with the main runner, a gating channel communicating with the branch runner, and a cavity communicating with the gating channel. During the injection stage of the injection molding machine, the molten magnesium alloy slurry in the nozzle 10 can enter the cavity through the outlet end 102, the main runner, the branch runner, and the gating channel. The resistance heating element 20 is located in the main body of the nozzle 10 and is used to convert the slurry in the channel from a semi-solid state to a molten state and maintain the slurry in the channel in a molten state. The resistance heating element 20 can be wound around the outer periphery of the nozzle 10, or it can be located at a certain position or area on the outer peripheral wall of the nozzle 10. For example, a resistance coil can be wound around the outer periphery of the nozzle 10 to achieve uniform heating of the main body of the nozzle 10 and effectively maintain the molten state of the slurry in the channel. The induction heating assembly 30 is arranged at the outlet end 102 and can perform rapid and localized induction heating on the location of the cold plug 200. The induction heating assembly 30 may include an induction coil 31, which is at least partially wound around the outer periphery of the outlet end 102 to ensure that the outlet end 102 obtains a concentrated and efficient electromagnetic induction heating effect, thereby achieving precise control of the state of the cold plug 200.

[0037] The injection molding machine may also include an operation panel 300. The operator can trigger the human-machine interface of the operation panel 300, causing it to send a production signal to the control mechanism, which then forwards the signal to the gating device 100. At this time, the gating device 100, based on the received production signal, controls the resistance heating element 20 to heat the nozzle 10, causing the slurry entering from the nozzle 10 inlet to change from a semi-solid state to a molten state and maintain it in that state. Simultaneously, it controls the induction heating element 30 to adjust the temperature of the area at the outlet 102 to a first preset holding temperature range at a first preset heating rate, keeping the cold plug 200 in a semi-solid state and effectively sealing the nozzle 10. The first preset holding temperature range is the temperature at which the cold plug 200 in the outlet 102 is kept in a semi-solid state, preventing high-temperature slurry from flowing out of the nozzle 10 during non-injection stages and reserving a controllable initial state for rapid melting during the injection stage.

[0038] When the gating device 100 receives the mold closing signal from the control mechanism, it controls the induction heating component 30 to adjust the temperature of the area where the nozzle 10 outlet end 102 is located to the second preset heat preservation temperature range at a second preset heating rate. This causes the cold plug 200 in the outlet end 102 to melt and outputs an injection signal to the control mechanism to trigger the injection molding machine to perform the injection action. At this time, the control mechanism controls the injection mechanism to start the injection process according to the received injection signal. Since the cold plug 200 no longer obstructs the molten slurry in the nozzle 10, the molten slurry can smoothly enter the cavity through the outlet end 102, the main runner, the branch runner, and the gating channel to complete the filling process, thereby avoiding flow obstruction and molding defects caused by the residue of the cold plug 200. The second preset heat preservation temperature range is higher than the first preset heat preservation temperature range, which is sufficient to completely melt the cold plug 200 without causing the slurry to overheat. The second preset heating rate is greater than the first preset heating rate in order to quickly melt the cold plug 200 after mold closing, shorten the waiting time, and improve cycle efficiency.

[0039] When the gating device 100 receives the injection completion signal from the control mechanism, it controls the induction heating component 30 to adjust the temperature of the area where the nozzle 10 outlet end 102 is located to a first preset heat preservation temperature range at a preset cooling rate, and outputs a mold opening signal to the control mechanism to trigger the injection molding machine to perform the mold opening action. At this time, the control mechanism controls the mold closing mechanism to open the mold according to the received mold opening signal. This heat preservation operation aims to prevent the temperature of the nozzle 10 outlet end 102 from being too high, which would cause residual slurry to overflow or splash at the moment of mold opening, and at the same time provide stable initial conditions for the formation of the cold plug 200 in the next mold.

[0040] The preset cooling rate is lower than the second preset heating rate because rapid heating is not required at this time. Instead, the temperature needs to be steadily reduced to a holding state to avoid excessive temperature fluctuations affecting the consistency of the cold plug 200 forming. The first preset holding temperature range is lower than the second preset holding temperature range because the former corresponds to the blocking standby state, while the latter corresponds to the injection preparation state. Adjusting the temperature to the first preset holding temperature range helps to quickly promote the local cooling of the residual slurry at the outlet end 102 after mold opening and form a structurally stable semi-solidified cold plug 200. This effectively blocks the nozzle 10 in the subsequent standby stage, prevents high-temperature melt leakage, and establishes repeatable and controllable initial thermal boundary conditions for the next injection cycle.

[0041] In summary, the technical solution provided by this invention, by integrating an induction heating component 30 into the gating device 100 and combining a phased, differentiated heating rate and holding temperature control strategy, can precisely regulate the state of the cold plug 200 at different process stages, balancing the needs of standby sealing and rapid melting before injection. Because induction heating has the characteristics of fast response, high local heating efficiency, and high temperature control accuracy, compared to the limitations of traditional resistance heating methods such as slow response and coarse temperature control, this solution is particularly suitable for high-performance magnesium alloys with a narrow semi-solid temperature range, effectively improving the reliability of injection molding and the consistency of the finished product.

[0042] In one embodiment, the first preset heating rate is not less than 0.5℃ / s and not more than 2℃ / s; the first preset heat preservation temperature range is not less than 450℃ and not more than 650℃.

[0043] In this embodiment, the first preset heating rate is preferably 1℃ / s, and the first preset holding temperature is preferably 580℃. This heating rate can ensure the stable formation of the cold plug 200 while avoiding local thermal stress concentration caused by excessively rapid heating. The holding temperature is close to the lower limit of the liquidus temperature of the semi-solid magnesium alloy, which helps to keep the cold plug 200 in the outlet end 102 in a semi-solid state. This can seal the nozzle 10 to prevent melt leakage and facilitate the complete melting of the cold plug 200 by rapid heating at the beginning of the next injection cycle.

[0044] In one embodiment, the second preset heating rate is not less than 6°C / s; the second preset heat preservation temperature range is not less than 470°C and not greater than 670°C.

[0045] In this embodiment, the second preset heating rate is preferably 8°C / s, and the second preset holding temperature is preferably 610°C. This heating rate can rapidly increase the temperature of the nozzle 10 outlet 102 area after mold closing, ensuring that the cold plug 200 melts fully in a short time, avoiding increased filling resistance due to insufficient or delayed heating; while this holding temperature is higher than the first preset holding temperature range and is within the temperature range required for complete melting of magnesium alloy, which helps maintain good melt fluidity, allowing the slurry to enter the mold cavity through the nozzle 10, and at the same time matches the rapid response characteristics of induction heating, improving the timing coordination of injection actions.

[0046] In one embodiment, the preset cooling rate is not less than 1°C / s.

[0047] In this embodiment, the preset cooling rate is preferably 2℃ / s. This cooling rate can relatively smoothly reduce the temperature of the nozzle 10 outlet 102 area from the second preset heat preservation temperature range to the first preset heat preservation temperature range after injection. This avoids local thermal shock or abnormal structure of the cold plug 200 caused by excessively rapid cooling, and also prevents residual melt from overflowing or splashing when the mold is opened due to excessively slow cooling. This provides a suitable thermal environment for the stable formation of the cold plug 200 in the next mold and helps maintain the continuity of temperature control and process repeatability throughout the molding cycle.

[0048] like Figure 8 and Figure 9 As shown, in one embodiment, the induction heating component 30 includes an induction coil 31 and an induction heating circuit 32. The induction heating circuit 32 includes a rectifier circuit 321 and an inverter circuit 322. The input terminal of the inverter circuit 322 is connected to the output terminal of the rectifier circuit 321, and the output terminal of the inverter circuit 322 is connected to the input terminal of the induction coil 31.

[0049] In this embodiment, the induction coil 31 serves as the core actuator of the induction heating assembly 30. Its winding position is close to the area where the cold plug 200 is formed, i.e., the outer periphery of the nozzle 10 outlet end 102, ensuring that the electromagnetic induction heating effect is concentrated on the part where the cold plug 200 is located, thereby achieving local rapid heating. The induction heating circuit 32 rectifies the power frequency AC power provided by the power grid into DC power through the rectifier circuit 321, and then inverts it into high frequency AC power with adjustable frequency and controllable amplitude through the inverter circuit 322, which supplies the induction coil 31 to generate an alternating magnetic field, thereby inducing eddy currents and generating Joule heat in the nozzle 10 outlet end 102.

[0050] Based on the above hardware structure, such as Figure 2 , Figure 8 and Figure 9 As shown, step S100 includes: S110. Upon receiving a production signal output from the semi-solid injection molding equipment, control the induction coil to heat the area where the nozzle outlet is located at a first preset heating rate. S120, Obtain the temperature of the area where the nozzle outlet is located; S130. Based on the temperature of the area where the nozzle outlet is located, adjust the DC voltage output from the rectifier circuit to the inverter circuit so that the temperature of the area where the nozzle outlet is located is within the first preset insulation temperature range.

[0051] In this embodiment, upon receiving a production signal from the control mechanism, the gating device 100 controls the resistance heating element 20 to heat the nozzle 10, causing the slurry entering from the nozzle 10 inlet to change from a semi-solid state to a molten state and maintain it in the molten state. Simultaneously, the induction coil 31 is controlled to heat the area where the nozzle 10 outlet 102 is located at a first preset heating rate. The temperature of the area where the nozzle 10 outlet 102 is located can be detected by a temperature detection element 42, such as a temperature sensor. The gating device 100 acquires the temperature detected by the temperature detection element 42 and adjusts the DC voltage output from the rectifier circuit 321 to the inverter circuit 322 based on the acquired temperature. In this way, the output power of the induction coil 31 can be adjusted to maintain the temperature of the area where the nozzle 10 outlet 102 is located within the first preset heat preservation temperature range, thereby ensuring that the cold plug 200 is in the required semi-solid state. This effectively seals the nozzle 10 to prevent melt leakage and establishes controllable initial thermal conditions for rapid melting in the subsequent injection stage.

[0052] like Figure 3 , Figure 8 and Figure 9 As shown, in one embodiment, step S130 includes: S131. Based on the temperature of the area where the nozzle outlet is located, adjust the trigger delay angle of the thyristor in the rectifier circuit so that the DC voltage output from the rectifier circuit to the inverter circuit is within the first preset DC voltage range, so that the temperature of the area where the nozzle outlet is located is within the first preset heat preservation temperature range.

[0053] In this embodiment, the rectifier circuit 321 includes a three-phase bridge rectifier. The three-phase bridge rectifier has advantages such as low output voltage ripple, high DC component, relatively low impact on grid harmonics, and suitability for high-power induction heating applications. During the actual operation of the injection molding machine, the three-phase 380V AC power from the grid first passes through the protection circuit 326 composed of fuses, and then enters the three-phase bridge rectifier composed of thyristors. The conduction timing of this three-phase bridge rectifier is controlled by the gating device 100 by adjusting the trigger delay angle α of the thyristors. The larger α is, the lower the average DC voltage of the rectified output, and vice versa.

[0054] Temperature sensor 42 collects the actual temperature of outlet 102 in real time and feeds it back to gate device 100. Based on the deviation between the first preset insulation temperature range and the measured temperature, gate device 100 executes a proportional-integral-derivative (PID) control algorithm, which calculates the optimal adjustment amount by combining the current error, historical cumulative error, and error change trend, and outputs the corresponding analog control signal, specifically 0 to 10 volts or 4 to 20 mA. This control signal is sent to the thyristor trigger board, which linearly converts it into the corresponding trigger delay angle α. For example, when the control signal is 0 volts or 4 mA, α is approximately 90 degrees, and the rectified output voltage is close to zero. When the control signal is 10 volts or 20 mA, α approaches 0 degrees, and the rectified output reaches its maximum value. The trigger board is synchronized with the phase of the AC power supply to generate a pulse sequence with precise phase delay, which drives the gate of the corresponding thyristor, thereby adjusting the amplitude of the DC voltage supplied to the inverter circuit 322. The inverter circuit 322 adjusts the high-frequency AC voltage output to the induction coil 31 accordingly, ultimately realizing closed-loop, stepless, and high-precision control of the temperature at the outlet 102.

[0055] This method, by adjusting the trigger delay angle of the thyristor, ensures that the temperature in the area of ​​the nozzle 10 outlet 102 remains stable within the first preset insulation temperature range, achieving efficient and stable temperature control and meeting the process requirements for precise control of the cold plug 200 state. This control method not only improves the response speed and temperature control stability of the induction heating component 30, but also enhances the overall electrothermal conversion efficiency of the rectification and inversion stages to a high level. It also features over-temperature protection and abnormal alarm capabilities, effectively supporting the dual process requirements of maintaining the semi-solid state of the cold plug 200 in the standby phase and instantaneously melting the cold plug 200 before mold closing, ensuring the continuity of the filling process and the consistency of product quality.

[0056] like Figure 4 , Figure 8 and Figure 9 As shown, in one embodiment, step S200 includes: S210. Upon receiving the mold closing signal output by the semi-solid injection molding equipment, control the induction coil to heat the area where the nozzle outlet end is located at a second preset heating rate. S220, Obtain the temperature of the area where the nozzle outlet is located; S230. Based on the temperature of the area where the nozzle outlet is located, adjust the DC voltage output from the rectifier circuit to the inverter circuit so that the temperature of the area where the nozzle outlet is located is within the second preset heat preservation temperature range. S240. When the temperature in the area where the nozzle exit end is located is within the second preset heat preservation temperature range, an injection signal is output to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform the injection action.

[0057] In this embodiment, after receiving the mold closing signal, the gating device 100 controls the induction coil 31 to heat the area where the nozzle 10 outlet end 102 is located at a second preset heating rate higher than the first preset heating rate. At the same time, the temperature of the area is acquired in real time through the temperature detection element 42 and fed back to the gating device 100. The gating device 100 adjusts the DC voltage output from the rectifier circuit 321 to the inverter circuit 322 according to the deviation between the temperature and the range of the second preset heat preservation temperature, thereby adjusting the output power of the induction coil 31 so that the temperature of the area where the nozzle 10 outlet end 102 is located quickly and stably reaches the range of the second preset heat preservation temperature. When it is confirmed that the temperature of the area is within the range of the second preset heat preservation temperature, the gating device 100 outputs an injection signal to the semi-solid injection molding equipment to ensure that the injection action is started under the condition that the cold plug 200 is completely melted and the channel is unobstructed. This effectively avoids the increase in filling resistance or poor flow caused by the cold plug 200 not being fully melted, thereby improving the molding stability and product quality consistency of the narrow semi-solid temperature range magnesium alloy during the injection process. The advantage of doing this is that it allows for precise control of the temperature change at the nozzle 10 outlet 102, ensuring that the cold plug 200 meets the requirements at different process stages, thereby guaranteeing the smooth progress of the entire molding process and the consistency of product quality.

[0058] like Figure 5 , Figure 8 and Figure 9 As shown, in one embodiment, step S230 includes: S231. Based on the temperature of the area where the nozzle outlet is located, adjust the trigger delay angle of the thyristor in the rectifier circuit so that the DC voltage output from the rectifier circuit to the inverter circuit is within the second preset DC voltage range, so that the temperature of the area where the nozzle outlet is located is within the second preset heat preservation temperature range.

[0059] In this embodiment, the gating device 100 monitors the temperature of the area where the nozzle 10 outlet 102 is located in real time through the temperature detection element 42, and adjusts the thyristor trigger delay angle in the rectifier circuit 321 according to the difference between the temperature and the range within the second preset heat preservation temperature range. This adjustment method can precisely control the DC voltage output from the rectifier circuit 321 to the inverter circuit 322, thereby adjusting the heating power of the induction coil 31.

[0060] When the actual temperature is below the second preset insulation temperature range, the gating device 100 reduces the trigger delay angle to increase the DC voltage and the heating power of the induction coil 31; conversely, if the actual temperature is above the second preset insulation temperature range, the trigger delay angle increases to reduce the DC voltage and the heating power of the induction coil 31. In this way, the temperature in the area where the nozzle 10 outlet end 102 is located can quickly and stably reach and maintain the second preset insulation temperature range, so that the cold plug 200 can completely melt, ensuring smooth and unobstructed material flow during injection, improving the efficiency of the molding process and the quality stability of the product.

[0061] like Figure 6 , Figure 8 and Figure 9 As shown, in one embodiment, step S300 includes: S310. Upon receiving the injection completion signal output by the semi-solid injection molding equipment, control the induction coil to heat the area where the nozzle exit end is located at a preset cooling rate. S320, Obtain the temperature of the area where the nozzle outlet is located; S330. Based on the temperature of the area where the nozzle outlet is located, adjust the DC voltage output from the rectifier circuit to the inverter circuit so that the temperature of the area where the nozzle outlet is located is within the first preset heat preservation range. S340. When the temperature in the area where the nozzle exit is located is within the first preset heat preservation range, output a mold opening signal to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform the mold opening action.

[0062] In this embodiment, after receiving the injection completion signal, the gating device 100 controls the induction coil 31 to heat the area where the nozzle 10 outlet end 102 is located at a preset cooling rate. This heating rate is lower than a second preset heating rate but higher than or adapted to the control capability required for the cooling process, so as to achieve a smooth transition from the high temperature of the injection stage to the heat preservation temperature of the standby stage. At the same time, the temperature of the area where the nozzle 10 outlet end 102 is located is continuously acquired by the temperature detection element 42 and fed back to the gating device 100. The gating device 100 determines the temperature based on the deviation between the acquired temperature and the first preset heat preservation temperature range. The DC voltage output from the rectifier circuit 321 to the inverter circuit 322 is adjusted to control the heating power of the induction coil 31, so that the temperature of the outlet end 102 area gradually drops and is stably maintained within the first preset heat preservation range. When it is confirmed that the temperature has entered the range, the gate device 100 outputs a mold opening signal to the semi-solid injection molding equipment to ensure that the mold is only opened after the nozzle 10 outlet end 102 is restored to the sealed state. This effectively prevents residual melt from overflowing or splashing at the moment of mold opening and establishes stable thermal initial conditions for the formation of the next mold cold plug 200, thereby ensuring the reliability of the process cycle and the consistency of product quality.

[0063] like Figure 7 , Figure 8 and Figure 9 As shown, in one embodiment, step S330 includes: S331. Based on the temperature of the area where the nozzle outlet is located, adjust the trigger delay angle of the thyristor in the rectifier circuit so that the DC voltage output from the rectifier circuit to the inverter circuit is within the first preset DC voltage range, so that the temperature of the area where the nozzle outlet is located is within the first preset heat preservation range.

[0064] In this embodiment, after receiving the injection completion signal, the gating device 100 continuously acquires the temperature of the area where the nozzle 10 outlet end 102 is located through the temperature detection element 42, and adjusts the trigger delay angle of the thyristor in the rectifier circuit 321 according to the deviation between the temperature and the first preset heat preservation temperature range. When the actual temperature is higher than the first preset heat preservation temperature range, the gating device 100 increases the trigger delay angle and reduces the DC voltage output by the rectifier circuit 321, thereby weakening the heating effect of the induction coil 31 on the nozzle 10 outlet end 102; when the actual temperature is close to or slightly lower than the lower limit of the first preset heat preservation temperature range, the trigger delay angle is appropriately reduced and the DC voltage is moderately increased to maintain the required heat preservation state. Through this control method, it can be ensured that the temperature of the area where the nozzle 10 outlet end 102 is located accurately drops and is stably maintained within the first preset heat preservation range, providing a suitable thermal environment for the reformation of the cold plug 200, and triggering the mold opening action after confirming that the temperature reaches the standard, effectively avoiding the overflow of high-temperature melt when the mold is opened, and establishing repeatable starting conditions for the next molding cycle.

[0065] The present invention also proposes a gating device 100, such as... Figure 8 and Figure 9 As shown, the gating device 100 includes a nozzle 10, a resistance heating element 20, an induction heating component 30, and a control component 41. The control component 41 includes a memory, a processor, and a control program for the gating device 100 stored in the memory and executed by the processor. When the control program for the gating device 100 is executed by the processor, it implements the control method for the gating device 100 as described above. The specific structure of the control method for the gating device 100 is as described in the above embodiments. Since this gating device 100 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0066] In this invention, the nozzle 10 has a flow channel 101 for slurry flow, and an inlet end and an outlet end 102 communicating with the flow channel 101. The inlet end is connected to the barrel of the injection mechanism to receive semi-solid magnesium alloy slurry, and the outlet end 102 is connected to and connected to the main runner inlet of the mold. The mold has a main runner, a branch runner communicating with the main runner, a gate channel communicating with the branch runner, and a cavity communicating with the gate channel. During the injection stage of the injection molding machine, the molten magnesium alloy slurry in the nozzle 10 can enter the cavity through the outlet end 102, the main runner, the branch runner, and the gate channel. A resistance heating element 20 is provided in the main body of the nozzle 10 to convert the slurry in the channel from a semi-solid state to a molten state and to maintain the slurry in the channel in a molten state. The resistance heating element 20 can be wound around the outer periphery of the nozzle 10, or it can be located at a certain position or area on the outer peripheral wall of the nozzle 10. For example, a resistance coil can be wound around the outer periphery of the nozzle 10 to achieve uniform heating of the main body of the nozzle 10 and effectively maintain the molten state of the slurry in the channel. The induction heating assembly 30 is arranged at the outlet end 102 and can perform rapid and localized induction heating on the location of the cold plug 200. The induction heating assembly 30 may include an induction coil 31, which is at least partially wound around the outer periphery of the outlet end 102 to ensure that the outlet end 102 obtains a concentrated and efficient electromagnetic induction heating effect, thereby achieving precise control of the state of the cold plug 200. The control assembly 41 is electrically connected to the resistance heating element 20, the induction heating assembly 30, and the control mechanism, respectively.

[0067] The injection molding machine may also include an operation panel 300. The operator can trigger the human-machine interface of the operation panel 300, causing it to send a production signal to the control mechanism, which then forwards the signal to the control component 41. At this time, the control component 41, based on the received production signal, controls the resistance heating element 20 to heat the nozzle 10, causing the slurry entering from the nozzle 10 inlet to change from a semi-solid state to a molten state and maintain it in that state. Simultaneously, it controls the induction heating element 30 to adjust the temperature of the area at the nozzle 10 outlet 102 to a first preset holding temperature range at a first preset heating rate, keeping the cold plug 200 in a semi-solid state and effectively sealing the nozzle 10. The first preset holding temperature range is the temperature at which the cold plug 200 in the outlet 102 is kept in a semi-solid state, preventing high-temperature slurry from flowing out of the nozzle 10 during non-injection stages and reserving a controllable initial state for rapid melting during the injection stage.

[0068] When the control component 41 receives the mold closing signal from the control mechanism, it controls the induction heating component 30 to adjust the temperature of the area where the nozzle 10 outlet end 102 is located to the second preset heat preservation temperature range at a second preset heating rate. This causes the cold plug 200 in the outlet end 102 to become molten, and an injection signal is output to the control mechanism to trigger the injection molding machine to perform the injection action. At this time, the control mechanism controls the injection mechanism to start the injection process according to the received injection signal. Since the cold plug 200 no longer obstructs the molten slurry in the nozzle 10, the molten slurry can smoothly enter the cavity through the outlet end 102, the main runner, the branch runner, and the gate channel to complete the filling process, avoiding flow obstruction and molding defects caused by the residue of the cold plug 200. The second preset heat preservation temperature range is higher than the first preset heat preservation temperature range, which is sufficient to completely melt the cold plug 200 without causing the slurry to overheat. The second preset heating rate is greater than the first preset heating rate in order to quickly melt the cold plug 200 after mold closing, shorten the waiting time, and improve cycle efficiency.

[0069] Upon receiving the injection completion signal from the control mechanism, the control component 41 controls the induction heating component 30 to adjust the temperature of the area where the nozzle 10 outlet end 102 is located to a first preset heat preservation temperature range at a preset cooling rate, and outputs a mold opening signal to the control mechanism to trigger the injection molding machine to perform the mold opening action. At this time, the control mechanism controls the mold closing mechanism to open the mold according to the received mold opening signal. This heat preservation operation aims to prevent the temperature of the nozzle 10 outlet end 102 from being too high, causing residual slurry to overflow or splash at the moment of mold opening, while providing stable initial conditions for the formation of the cold plug 200 in the next mold.

[0070] The preset cooling rate is lower than the second preset heating rate because rapid heating is not required at this time. Instead, the temperature needs to be steadily reduced to a holding state to avoid excessive temperature fluctuations affecting the consistency of the cold plug 200 forming. The first preset holding temperature range is lower than the second preset holding temperature range because the former corresponds to the blocking standby state, while the latter corresponds to the injection preparation state. Adjusting the temperature to the first preset holding temperature range helps to quickly promote the local cooling of the residual slurry at the outlet end 102 after mold opening and form a structurally stable semi-solidified cold plug 200. This effectively blocks the nozzle 10 in the subsequent standby stage, prevents high-temperature melt leakage, and establishes repeatable and controllable initial thermal boundary conditions for the next injection cycle.

[0071] In summary, the technical solution provided by this invention, by integrating an induction heating component 30 into the gating device 100 and combining a phased, differentiated heating rate and holding temperature control strategy, can precisely regulate the state of the cold plug 200 at different process stages, balancing the needs of standby sealing and rapid melting before injection. Because induction heating has the characteristics of fast response, high local heating efficiency, and high temperature control accuracy, compared to the limitations of traditional resistance heating methods such as slow response and coarse temperature control, this solution is particularly suitable for high-performance magnesium alloys with a narrow semi-solid temperature range, effectively improving the reliability of injection molding and the consistency of the finished product.

[0072] like Figure 8 to Figure 10 As shown, in one embodiment, the induction heating assembly 30 includes: An induction coil 31 is wound around the outer periphery of the outlet end 102 and is used to heat the outlet end 102. The induction heating circuit 32 includes a rectifier circuit 321 and an inverter circuit 322, which are electrically connected to the control component 41. The rectifier circuit 321 converts the input AC power into DC power and outputs it to the inverter circuit 322. The input terminal of the inverter circuit 322 is connected to the output terminal of the rectifier circuit 321, and the output terminal of the inverter circuit 322 is connected to the input terminal of the induction coil 31. The inverter circuit 322 converts the DC power into high-frequency AC power and outputs it to the induction coil 31. The control component 41 is also used to adjust the DC voltage output from the rectifier circuit 321 to the inverter circuit 322 according to the temperature of the area where the outlet end 102 is located, so that the temperature of the area where the outlet end 102 is located is within a first preset heat preservation range or a second preset heat preservation range.

[0073] In this embodiment, the induction coil 31 serves as the core actuator of the induction heating assembly 30. Its winding position is close to the area where the cold plug 200 is formed, i.e., the outer periphery of the nozzle 10 outlet end 102, ensuring that the electromagnetic induction heating effect is concentrated on the part where the cold plug 200 is located, thereby achieving local rapid heating. The induction heating circuit 32 rectifies the power frequency AC power provided by the power grid into DC power through the rectifier circuit 321, and then inverts it into high frequency AC power with adjustable frequency and controllable amplitude through the inverter circuit 322, which supplies the induction coil 31 to generate an alternating magnetic field, thereby inducing eddy currents and generating Joule heat in the nozzle 10 outlet end 102.

[0074] Based on production signals, mold closing signals, or injection completion signals from the injection molding machine control mechanism, the control component 41 adjusts the DC voltage output from the rectifier circuit 321 to the inverter circuit 322, thereby regulating the amplitude of the high-frequency AC voltage output from the inverter circuit 322 to the induction coil 31. This controls the output power of the induction coil 31, ensuring that the temperature of the outlet end 102 remains stable within the first preset holding temperature range for the semi-solid state of the corresponding cold plug 200 or the second preset holding temperature range for the fully molten state at different process stages. By utilizing the rapid response, high power density, and precise temperature control of induction heating, the limitations of traditional resistance wire heating—which suffers from high thermal inertia, slow heating, and uneven temperature distribution, making it difficult to adapt to the narrow semi-solid temperature range requirements of magnesium alloy processes—are overcome. This effectively suppresses slurry outflow during the standby stage and instantly melts the cold plug 200 before injection, ensuring smooth filling of the cavity by the molten slurry and improving the stability of the molding process and the consistency of product quality.

[0075] It should be noted that compared to resistance heating, induction heating is a faster and more efficient heating method, and it has been widely used in brazing, quenching, smelting, and through-heating. However, traditional induction heating systems mostly use analog circuits for parameter adjustment and rely on hardware circuits for power output control, with an overall efficiency typically only 65% ​​to 75%. Such systems suffer from poor temperature control accuracy, fluctuations of up to ±50 degrees Celsius, inability to achieve stepless power adjustment, and a lack of protection mechanisms, including overheat protection and fault alarm functions. Therefore, they cannot meet the requirements for precise, rapid, and safe heating control in single-point or multi-point hot runner systems in semi-solid magnesium alloy injection molding.

[0076] In this invention, the control component 41 adjusts the trigger delay angle of the thyristor based on the actual temperature fed back by the temperature sensor 42, combined with either a first or second preset insulation temperature range. This continuously adjusts the DC voltage output by the rectifier circuit 321, ultimately changing the output power of the induction coil 31. This forms a closed-loop control process with the measured temperature as input and voltage regulation as the means, effectively improving the accuracy and reliability of temperature control. This control method not only improves temperature control accuracy and response speed but also supports the strict temperature control requirements of narrow semi-solid temperature range magnesium alloys at different process stages, ensuring the continuity of the entire production process and the high-quality consistency of the products.

[0077] like Figure 8 to Figure 10 As shown, in one embodiment, the induction heating circuit 32 further includes a filter circuit 323. The input terminal of the filter circuit 323 is connected to the output terminal of the rectifier circuit 321, and the output terminal of the filter circuit 323 is connected to the input terminal of the inverter circuit 322. The filter circuit 323 is used to filter out the low-frequency ripple in the DC power output by the rectifier circuit 321 and then output it to the inverter circuit 322.

[0078] In this embodiment, the DC output of the rectifier circuit 321 is not completely smooth, but contains low-frequency ripple components generated by the three-phase AC rectification. The frequency of this ripple is typically six times the grid frequency, i.e., 300 Hz or 360 Hz. If DC with this ripple is directly supplied to the inverter circuit 322, it may cause fluctuations in the output current, thereby affecting the stability and temperature control accuracy of the induction coil 31. Therefore, a filter circuit 323 is placed between the rectifier circuit 321 and the inverter circuit 322. This filter circuit 323 can consist of one or more sets of large-capacity electrolytic capacitors to absorb the low-frequency ripple energy in the rectified output, making the DC bus voltage supplied to the inverter circuit 322 more stable.

[0079] Furthermore, the inverter circuit 322 can employ a full-bridge or half-bridge topology composed of insulated-gate bipolar transistors (IGBTs), operating in a high-frequency switching state of 10 kHz to 30 kHz. At the instant of conduction in each switching cycle, the inverter circuit 322 needs to draw a large instantaneous current from the DC bus. If this instantaneous current relies entirely on the preceding rectifier circuit 321 through a long line, the distributed inductance of the line will cause a significant drop in the bus voltage, or even voltage spikes. This may not only interfere with the control signal but also adversely affect semiconductor components such as the IGBTs. However, the capacitor bank in the filter circuit 323, being close to the inverter bridge arm, can provide the required large instantaneous current nearby, effectively suppressing voltage fluctuations.

[0080] Therefore, the filter circuit 323 can not only improve the quality of the rectified DC power, but also provide reliable local energy storage support for the high-frequency inverter process, thereby enhancing the dynamic response capability, electromagnetic compatibility and long-term operational reliability of the entire induction heating assembly 30.

[0081] like Figure 8 to Figure 10 As shown, in one embodiment, the induction heating circuit 32 further includes a resonant circuit 324. The input terminal of the resonant circuit 324 is connected to the output terminal of the inverter circuit 322, and the output terminal of the resonant circuit 324 is connected to the input terminal of the induction coil 31. The resonant circuit 324 is used to compensate for the inductive reactive power of the induction coil 31.

[0082] In this embodiment, the induction coil 31 itself has a large inductance. If it is directly connected to the output terminal of the inverter circuit 322, the current flowing through the induction coil 31 will cause the entire induction heating circuit 32 to exhibit high inductance due to its strong inductive reactance, resulting in a significant reduction in the power factor. In this case, the insulated-gate bipolar transistor in the inverter circuit 322 needs to output a large current, but the actual effective power used to generate heat is very small, which not only wastes energy but may also affect the reliability of the device due to overcurrent stress.

[0083] To address this issue, a resonant circuit 324 is introduced into the induction heating circuit 32. Its input is connected to the output of the inverter circuit 322, and its output is connected to the input of the induction coil 31. This resonant circuit 324 can be composed of one or more capacitors, forming a series structure with the induction coil 31 consisting of a capacitor and an inductor. The capacitive reactance of this series structure cancels out the inductive reactance of the induction coil 31 at a specific frequency, which is the resonant frequency, determined by the inductance of the induction coil 31 and the capacitance of the resonant capacitor. When the high-frequency AC voltage output by the inverter circuit 322 is close to or equal to this resonant frequency, the total impedance of the series structure formed by the capacitor and the induction coil 31 reaches its minimum and exhibits approximately pure resistivity. At this time, even if the voltage amplitude output by the inverter circuit 322 is not high, it can still induce a large-amplitude sinusoidal AC current in the induction coil 31. This large current induces strong eddy currents in the outlet 102 of the nozzle 10, thereby efficiently generating Joule heating and achieving rapid and concentrated heating of the cold plug 200 region.

[0084] It can be seen that by setting the resonant circuit 324, not only can the energy utilization efficiency of the induction heating component 30 be improved and the current burden of the inverter circuit 322 be reduced, but the overall electrical performance can also be improved, providing the necessary electrical foundation for precise and stable control of the outlet end 102 temperature. It is especially suitable for the narrow semi-solid temperature range magnesium alloy injection molding process with high requirements for heating response speed and temperature control accuracy.

[0085] like Figure 8 to Figure 10 As shown, in one embodiment, the induction heating circuit 32 further includes an isolation transformer circuit 325, the input terminal of which is connected to the output terminal of the inverter circuit 322, and the output terminal of the isolation transformer circuit 325 is connected to the input terminal of the resonant circuit 324.

[0086] In this embodiment, the main function of the isolation transformer circuit 325 is to provide electrical isolation and voltage matching, ensuring that the high-frequency AC voltage is safely and efficiently transmitted from the inverter circuit 322 to the resonant circuit 324. Since the inverter circuit 322 outputs a high-frequency AC voltage, if it is directly connected to the resonant circuit 324, common-mode interference may be introduced due to lack of isolation, or voltage mismatch may occur, thereby affecting the stability and controllability of the heating process.

[0087] The isolation transformer circuit 325 can be constructed from a high-frequency transformer, with its primary winding connected to the output of the inverter circuit 322 and its secondary winding connected to the input of the resonant circuit 324. This structure can effectively cut off the DC path between the preceding and following stages under high-frequency operating conditions, suppress parasitic coupling, and reduce electromagnetic interference to the control component 41 and surrounding circuits. Simultaneously, by rationally designing the transformer's turns ratio, the voltage amplitude output by the inverter circuit 322 can be adapted, allowing the resonant circuit 324 to obtain a suitable excitation level near its design frequency. This facilitates the establishment of a stable and sufficiently large alternating current in the induction coil 31.

[0088] In actual operation, this configuration helps ensure the reliability of the induction heating process at the nozzle 10 outlet 102. When the control component 41 adjusts the high-frequency AC voltage output by the inverter circuit 322, the voltage transmitted to the resonant circuit 324 via the isolation transformer circuit 325 can drive the induction coil 31 more smoothly, generating the required eddy current heating effect at the outlet 102. This provides a stable electrical energy basis for maintaining the cold plug 200 in a semi-solid state during the standby phase and rapidly heating it to a molten state before mold closing, and also supports the controlled temperature drop after injection. With the introduction of the isolation transformer circuit 325, the entire induction heating path is improved in terms of electrical safety, anti-interference capability, and energy transmission efficiency, thereby better meeting the process requirements of precise control of the cold plug 200 state for magnesium alloys with narrow semi-solid temperature range.

[0089] like Figure 8 to Figure 10 As shown, in one embodiment, the gating device 100 further includes a gating port 50 for mounting on the mold, and a nozzle 10 is inserted into the gating port 50; the induction coil 31 is located between the inner peripheral wall of the gating port 50 and the outer peripheral wall of the nozzle 10.

[0090] In this embodiment, the filling port 50 is mounted on the mold and has a through cavity inside. The nozzle 10 passes through this cavity, ensuring that the outlet end 102 of the nozzle 10 is precisely aligned with the main channel inlet of the mold and maintains a sealed connection. The induction coil 31 is arranged in the annular gap between the inner peripheral wall of the filling port 50 and the outer peripheral wall of the nozzle 10, surrounding the outlet end 102 of the nozzle 10, ensuring that the electromagnetic induction heating effect is concentrated on the location where the cold plug 200 is formed. The filling port 50 not only provides mechanical support and alignment for the nozzle 10, but also reduces heat loss to the surrounding environment through its enveloping layout, creating a localized heat-insulating environment. Simultaneously, embedding the induction coil 31 within the limited space between the filling port 50 and the nozzle 10 avoids external interference and improves the targeting and efficiency of heating. The induction heating component 30 can work closely with the mold to achieve rapid and precise control of the temperature at the outlet 102 without changing the original injection mechanism layout. This effectively supports the dual process requirements of maintaining the semi-solid state of the cold plug 200 in the standby stage and instantly melting the cold plug 200 before mold closing, thus ensuring smooth filling and product molding quality.

[0091] like Figure 8 to Figure 10 As shown, in one embodiment, the induction heating assembly 30 further includes an insulating member 60, which is wrapped around the outer periphery of the outlet end 102 and located between the induction coil 31 and the inlet 50, for isolating the induction coil 31 and the inlet 50.

[0092] In this embodiment, the insulating component 60 is wound around the outer periphery of the nozzle 10 outlet end 102 and located between the induction coil 31 and the gating port 50. Since the gating port 50 is usually made of metal and fixed to the mold, if the induction coil 31 directly contacts the gating port 50, energy loss, local overheating, or even electrical short circuit may occur due to conductivity or eddy current coupling. Therefore, the insulating component 60 can effectively isolate the electrical connection and heat conduction path between the induction coil 31 and the gating port 50, and prevent the high-frequency alternating magnetic field from inducing parasitic eddy currents in the gating port 50, thereby reducing unnecessary energy loss and ensuring operational safety. At the same time, the insulating component 60 can be made of high-temperature resistant, high-dielectric-strength engineering ceramics or mica, which not only meets the electrical insulation requirements but also can withstand the high-temperature environment generated during induction heating. In this way, the energy of the induction coil 31 can be concentrated on the magnesium alloy cold plug 200 area of ​​the nozzle 10 outlet end 102, improving heating efficiency and temperature control accuracy, while ensuring the reliability and stability of the entire gating device 100 during long-term operation.

[0093] like Figure 8 to Figure 10 As shown, in one embodiment, the induction heating assembly 30 further includes a coil housing 70, which is disposed inside the inlet 50 and wound around the outer periphery of the induction coil 31; an insulating member 60 is disposed on the coil housing 70.

[0094] In this embodiment, the coil housing 70 is disposed inside the filling port 50 and surrounds the outer periphery of the induction coil 31. The insulating component 60 is disposed on the inner surface of the coil housing 70, specifically between the induction coil 31 and the filling port 50, for electrical isolation. Since the filling port 50 is usually made of conductive metal material and directly fixed to the mold, if the induction coil 31 is in direct contact with the filling port 50 or too close to it during high-frequency operation, parasitic eddy currents may be generated in the filling port 50 due to electromagnetic coupling, which may not only cause energy loss but also lead to local overheating or even affect the normal operation of the induction coil 31. By introducing the coil housing 70, on the one hand, mechanical protection and structural support can be provided for the induction coil 31, making it stable under high temperature, vibration and other conditions; on the other hand, a reliable mounting surface can be provided for the insulating component 60, ensuring that it isolates the electrical path between the induction coil 31 and the filling port 50. The insulating component 60 can be made of high-temperature resistant, high-dielectric-strength materials, such as ceramic or mica composite materials, which can maintain good insulation performance under long-term high-temperature environments. This structural layout allows the induction coil 31 to be reliably integrated into the outlet end 102 of the nozzle 10. While ensuring electrical safety, it helps to concentrate electromagnetic energy at the location of the cold plug 200, thereby supporting rapid and precise control of the state of the magnesium alloy cold plug 200 in the narrow semi-solid temperature range.

[0095] like Figure 8 to Figure 10 As shown, in one embodiment, the gate device 100 further includes a cover plate 80 and an adjusting ring 90. The cover plate 80 is used to install the gate 50 on the mold, and the adjusting ring 90 is disposed inside the gate 50 and connected to the nozzle 10. The adjusting ring 90 is used to compensate for the concentricity deviation between the nozzle 10, the gate 50 and the cover plate 80.

[0096] In this embodiment, the cover plate 80 is fixedly installed on the mold and serves as the connection interface between the gating device 100 and the mold; the adjusting ring 90 is disposed on the cover plate 80 and is connected to the outlet end 102 of the nozzle 10 to form a channel for the slurry to transition from the nozzle 10 to the main channel of the mold.

[0097] It is understandable that, since the nozzle 10, the inlet 50, and the cover plate 80 are manufactured and assembled from different components, minor geometric deviations are difficult to completely avoid during actual manufacturing and installation. This may lead to incomplete alignment of their axes, affecting the smoothness of slurry flow and even causing localized leakage or displacement of the cold plug 200. Therefore, the adjusting ring 90 is designed as a finely adjustable or appropriately fitted ring structure. Through its own positioning or elastic compensation capabilities, it effectively alleviates concentricity deviations between the nozzle 10, the inlet 50, and the cover plate 80, ensuring good overall alignment of the flow channel 101. This not only improves the sealing reliability between the gating device 100 and the mold but also ensures a smooth transition of the molten magnesium alloy slurry from the outlet 102 to the main runner inlet, avoiding flow disturbances or uneven filling caused by misalignment between the outlet 102 and the main runner inlet. This is especially beneficial for materials with high process stability requirements, such as magnesium alloys with narrow semi-solid temperature ranges, helping to maintain the consistency of the cold plug 200 position and the repeatability of the heating effect, thereby improving the overall precision of the injection molding process and the quality of the product.

[0098] To achieve simultaneous manufacturing of two magnesium alloy products, such as Figure 11As shown, in one embodiment, the flow channel 101 inside the nozzle 10 is divided into a first flow channel 1011 and a second flow channel 1012, which correspond to the slurry delivery paths required for the two products, respectively. Correspondingly, the outlet end 102 of the nozzle 10 is also divided into a first outlet end 1021 and a second outlet end 1022, wherein the first outlet end 1021 is connected to the first mold cavity, and the second outlet end 1022 is connected to the second mold cavity, ensuring that the two streams of molten slurry can enter their respective cavities to complete filling. To maintain the molten state of the slurry in each flow channel 101, the resistance heating element 20 is correspondingly configured as a first resistance heating element 21 and a second resistance heating element 22, which are respectively arranged in the outer peripheral areas of the nozzle 10 corresponding to the first flow channel 1011 and the second flow channel 1012, to achieve zoned temperature control of different flow channels 101. Meanwhile, the induction coil 31 in the induction heating assembly 30 is also divided into a first induction coil 311 and a second induction coil 312. The first induction coil 311 is wound around the outer periphery of the first outlet end 1021 and is used to independently control the heating of the cold plug 200 at the first outlet end 1021. The second induction coil 312 is wound around the outer periphery of the second outlet end 1022 to achieve precise management of the state of the cold plug 200 at the second outlet end 1022. The control assembly 41 can adjust the working parameters of the two sets of resistance heating elements 20 and induction coil 31 according to process requirements, so that the cold plug 200 at the first outlet end 1021 and the second outlet end 1022 are kept in a semi-solid state during the standby stage, heated to the molten state as needed before mold closing, and simultaneously cooled and reset after injection. This multi-channel design not only supports the efficient production of dual-cavity molds, but also retains the ability to independently control the thermal state of each outlet end 102, effectively adapting to the slight process differences that may exist in multi-cavity molding and improving product consistency.

[0099] Furthermore, the filling port 50 may include a first filling port 51 and a second filling port 52, respectively mounted on the mold and corresponding to the first outlet end 1021 and the second outlet end 1022, providing a localized heat preservation environment and ensuring the sealing and alignment between the nozzle 10 and the first and second molds. The insulating member 60 may include a first insulating member 61 and a second insulating member 62. The first insulating member 61 is located outside the first induction coil 311 to isolate the first induction coil 311 from the first filling port 51, and the second insulating member 62 is located outside the second induction coil 312 to isolate the second induction coil 312 from the second filling port 52, preventing electromagnetic interference and energy loss. The coil housing 70 may include a first coil housing 71 and a second coil housing 72, respectively surrounding the first induction coil 311 and the second induction coil 312, providing mechanical protection and structural support. The cover plate 80 may include a first cover plate 81 and a second cover plate 82, respectively fixed to the first and second molds, serving as the connection interface between the gating device 100 and the first and second molds. The adjusting ring 90 may include a first adjusting ring 91 and a second adjusting ring 92, which are respectively disposed on the first cover plate 81 and the second cover plate 82. The first adjusting ring 91 is used to compensate for the concentricity deviation between the nozzle 10, the first inlet 51 and the first cover plate 81, while the second adjusting ring 92 is used to compensate for the concentricity deviation between the nozzle 10, the second inlet 52 and the second cover plate 82, so as to ensure that the overall alignment of the flow channel 101 is good.

[0100] Therefore, when manufacturing three or more magnesium alloy products simultaneously, the above design concept can be applied, further expanding the number of flow channels 101, outlets 102, resistance heating elements 20, induction coils 31, inlets 50, insulating components 60, coil housings 70, cover plates 80, and adjusting rings 90. Independent temperature management and process parameter settings can be implemented for each channel according to specific needs. For example, a third flow channel 101, a third outlet 102, a third resistance heating element 20, a third induction coil 31, etc., can be added. This design not only improves production efficiency but also ensures the quality consistency of each product during multi-cavity molding, meeting the requirements of complex production processes. In this way, injection molding machines can increase production capacity without affecting product quality, making them suitable for large-scale, diversified industrial production scenarios. This method is particularly suitable for the production of new magnesium alloys with narrow semi-solid temperature zones because it can precisely control the state of the cold plug 200 at different process stages, balancing the needs of standby heat preservation and rapid melting before injection, thereby improving the injection molding reliability and product consistency of semi-solid magnesium alloys, especially high-performance alloys.

[0101] The present invention also proposes a semi-solid injection molding equipment, which includes a gating device 100. The specific structure of the gating device 100 is as described in the above embodiments. Since the present semi-solid injection molding equipment adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0102] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for controlling a gating device, characterized in that, For a semi-solid injection molding apparatus, the gating device includes an induction heating component and a nozzle, and the control method of the gating device includes: Upon receiving the production signal output by the semi-solid injection molding equipment, the induction heating component is controlled to adjust the temperature of the area where the nozzle outlet end is located to the range of the first preset heat preservation temperature at the first preset heating rate, so that the cold plug in the outlet end is in a semi-solid state to seal the nozzle. Upon receiving the mold closing signal output by the semi-solid injection molding equipment, the induction heating component is controlled to adjust the temperature of the area where the nozzle outlet end is located to the range of the second preset heat preservation temperature at the second preset heating rate, so that the cold plug in the outlet end turns into a molten state, and an injection signal is output to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform the injection action. Upon receiving the injection completion signal output by the semi-solid injection molding equipment, the induction heating component is controlled to adjust the temperature of the area where the nozzle outlet is located to the first preset heat preservation temperature range at a preset cooling rate, and outputs a mold opening signal to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform the mold opening action. Wherein, the first preset heating rate is less than the second preset heating rate, and the preset cooling rate is less than the second preset heating rate; The first preset insulation temperature range is smaller than the second preset insulation temperature range.

2. The control method for the gating device as described in claim 1, characterized in that, The first preset heating rate is not less than 0.5℃ / s and not greater than 2℃ / s; the first preset heat preservation temperature range is not less than 450℃ and not greater than 650℃; and / or The second preset heating rate is not less than 6℃ / s; the second preset heat preservation temperature is not less than 470℃ and not greater than 670℃; and / or The preset cooling rate is not less than 1℃ / s.

3. The control method for the gating device as described in claim 1, characterized in that, The induction heating assembly includes an induction coil and an induction heating circuit. The induction heating circuit includes a rectifier circuit and an inverter circuit. The input terminal of the inverter circuit is connected to the output terminal of the rectifier circuit, and the output terminal of the inverter circuit is connected to the input terminal of the induction coil. Upon receiving a production signal output by the semi-solid injection molding equipment, controlling the induction heating component to adjust the temperature of the area where the nozzle exit end is located to a first preset heat preservation temperature range at a first preset heating rate, so that the cold plug in the exit end is in a semi-solid state to seal the nozzle, includes: Upon receiving the production signal output by the semi-solid injection molding equipment, the induction coil is controlled to heat the area where the nozzle outlet end is located at the first preset heating rate; Obtain the temperature of the area where the nozzle outlet is located; Based on the temperature of the area where the nozzle outlet is located, the DC voltage output from the rectifier circuit to the inverter circuit is adjusted so that the temperature of the area where the nozzle outlet is located is within the first preset insulation temperature range.

4. The control method for the gating device as described in claim 3, characterized in that, The step of adjusting the DC voltage output from the rectifier circuit to the inverter circuit based on the obtained temperature of the area where the nozzle outlet is located, so that the temperature of the area where the nozzle outlet is located is within the first preset insulation temperature range, includes: Based on the temperature of the area where the nozzle outlet is located, the trigger delay angle of the thyristor in the rectifier circuit is adjusted so that the DC voltage output from the rectifier circuit to the inverter circuit is within a first preset DC voltage range, and the temperature of the area where the nozzle outlet is located is within the first preset insulation temperature range.

5. The control method for the gating device as described in claim 1, characterized in that, The induction heating assembly includes an induction coil and an induction heating circuit. The induction heating circuit includes a rectifier circuit and an inverter circuit. The input terminal of the inverter circuit is connected to the output terminal of the rectifier circuit, and the output terminal of the inverter circuit is connected to the input terminal of the induction coil. Upon receiving the mold closing signal output by the semi-solid injection molding equipment, controlling the induction heating component to adjust the temperature of the area where the nozzle exit end is located to a second preset heat preservation temperature range at a second preset heating rate, so that the cold plug in the exit end turns into a molten state, and outputting an injection signal to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform an injection action includes: Upon receiving the mold closing signal output by the semi-solid injection molding equipment, the induction coil is controlled to heat the area where the nozzle outlet end is located at the second preset heating rate; Obtain the temperature of the area where the nozzle outlet is located; Based on the temperature of the area where the nozzle outlet is located, the DC voltage output from the rectifier circuit to the inverter circuit is adjusted so that the temperature of the area where the nozzle outlet is located is within the second preset heat preservation temperature range. When the temperature in the area where the nozzle outlet is located is within the second preset heat preservation temperature range, an injection signal is output to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform an injection action.

6. The control method for the gating device as described in claim 5, characterized in that, The step of adjusting the DC voltage output from the rectifier circuit to the inverter circuit based on the obtained temperature of the area where the nozzle outlet is located, so that the temperature of the area where the nozzle outlet is located is within the second preset insulation temperature range, includes: Based on the temperature of the area where the nozzle outlet is located, the trigger delay angle of the thyristor in the rectifier circuit is adjusted so that the DC voltage output from the rectifier circuit to the inverter circuit is within the second preset DC voltage range, and the temperature of the area where the nozzle outlet is located is within the second preset insulation temperature range.

7. The control method for the gating device as described in claim 1, characterized in that, The induction heating assembly includes an induction coil and an induction heating circuit. The induction heating circuit includes a rectifier circuit and an inverter circuit. The input terminal of the inverter circuit is connected to the output terminal of the rectifier circuit, and the output terminal of the inverter circuit is connected to the input terminal of the induction coil. Upon receiving the injection completion signal output by the semi-solid injection molding equipment, controlling the induction heating component to adjust the temperature of the area where the nozzle exit end is located to the first preset heat preservation temperature range at a preset cooling rate for heat preservation, and outputting a mold opening signal to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform the mold opening action includes: Upon receiving the injection completion signal output by the semi-solid injection molding equipment, the induction coil is controlled to heat the area where the nozzle outlet end is located at the preset cooling rate. Obtain the temperature of the area where the nozzle outlet is located; Based on the temperature of the area where the nozzle outlet is located, the DC voltage output from the rectifier circuit to the inverter circuit is adjusted so that the temperature of the area where the nozzle outlet is located is within the first preset insulation temperature range. When the temperature in the area where the nozzle outlet is located is within the first preset heat preservation temperature range, an opening signal is output to the semi-solid injection molding equipment to trigger the semi-solid injection molding equipment to perform the opening action.

8. The control method for the gating device as described in claim 7, characterized in that, The step of adjusting the DC voltage output from the rectifier circuit to the inverter circuit based on the obtained temperature of the area where the nozzle outlet is located, so that the temperature of the area where the nozzle outlet is located is within the first preset insulation temperature range, includes: Based on the temperature of the area where the nozzle outlet is located, the trigger delay angle of the thyristor in the rectifier circuit is adjusted so that the DC voltage output from the rectifier circuit to the inverter circuit is within a first preset DC voltage range, and the temperature of the area where the nozzle outlet is located is within the first preset insulation temperature range.

9. A gating device, characterized in that, For use in semi-solid injection molding equipment, the gating device includes: The nozzle has a flow channel for supplying slurry and an outlet end communicating with the flow channel, the outlet end being used to communicate with a mold cavity; A resistance heating element is disposed on the nozzle for heating the nozzle; An induction heating component is disposed at the outlet end and is used to heat the outlet end; A control component is electrically connected to the resistance heating element and the induction heating element, respectively. The control component includes a memory, a processor, and a control program for the gating device stored in the memory and executed by the processor. When executed by the processor, the control program for the gating device implements the control method for the gating device as described in any one of claims 1 to 8.

10. The gating device as described in claim 9, characterized in that, The induction heating component includes: An induction coil is wound around the outer periphery of the outlet end for heating the outlet end; An induction heating circuit includes a rectifier circuit and an inverter circuit, which are electrically connected to the control component. The rectifier circuit converts the input AC power into DC power and outputs it to the inverter circuit. The input terminal of the inverter circuit is connected to the output terminal of the rectifier circuit, and the output terminal of the inverter circuit is connected to the input terminal of the induction coil. The inverter circuit converts the DC power into high-frequency AC power and outputs it to the induction coil. The control component is further configured to adjust the DC voltage output from the rectifier circuit to the inverter circuit based on the temperature of the area where the outlet is located, so that the temperature of the area where the outlet is located is within a first preset heat preservation range or a second preset heat preservation range.

11. The gating device as claimed in claim 10, characterized in that, The induction heating circuit also includes a filter circuit. The input terminal of the filter circuit is connected to the output terminal of the rectifier circuit, and the output terminal of the filter circuit is connected to the input terminal of the inverter circuit. The filter circuit is used to filter out the low-frequency ripple in the DC power output by the rectifier circuit before outputting it to the inverter circuit. And / or, the induction heating circuit further includes a resonant circuit, the input terminal of which is connected to the output terminal of the inverter circuit, and the output terminal of which is connected to the input terminal of the induction coil. The resonant circuit is used to compensate for the inductive reactive power of the induction coil.

12. The gating device as claimed in claim 10, characterized in that, The gating device further includes a sprue for installation on the mold, and the nozzle is inserted into the sprue; the induction coil is located between the inner peripheral wall of the sprue and the outer peripheral wall of the nozzle.

13. The gating device as described in claim 12, characterized in that, The induction heating assembly also includes an insulating component, which is wrapped around the outer periphery of the outlet end and located between the induction coil and the filling port, for isolating the induction coil from the filling port.

14. The gating device as claimed in claim 13, characterized in that, The induction heating assembly further includes a coil housing, which is disposed inside the inlet and wound around the outer periphery of the induction coil; the insulating component is disposed on the coil housing.

15. The gating device as claimed in claim 12, characterized in that, The gating device further includes a cover plate and an adjusting ring. The cover plate is used to install the gating opening onto the mold. The adjusting ring is located inside the gating opening and is connected to the nozzle. The adjusting ring is used to compensate for concentricity deviations between the nozzle, the gating opening, and the cover plate.

16. A semi-solid injection molding device, characterized in that, Includes the gating device as described in any one of claims 9 to 15.

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