A temperature control device and system for die-casting an automobile aluminum-magnesium alloy accessory

Abstract

This invention relates to a temperature control device and system for die-casting automotive aluminum-magnesium alloy parts, belonging to the field of automotive parts manufacturing technology. It includes a layered temperature measurement module, a zoned heating module, a zoned conformal cooling module, and a main control unit. The layered temperature measurement module is distributed on the surface of the cavity, in the runner, and deep within the mold base. Surface temperature sensing points are integrated into movable hollow ejector pins to eliminate temperature measurement hysteresis and resist injection impact; deep temperature sensing points are equipped with elastic pre-tightening mechanisms to eliminate contact thermal resistance. The zoned conformal cooling module is formed using additive manufacturing, with its three-dimensional flow channel trajectory conforming to the cavity contour and evenly distributed, combined with proportional valves and dual-parameter monitoring of flow and pressure. This invention achieves multi-dimensional precise temperature control from local to macroscopic levels, eliminating heat exchange dead zones and "heat spots" in complex deep cavities, effectively avoiding defects such as casting shrinkage cavities, and improving yield.

Description

Technical Field

[0001] This invention belongs to the field of automotive parts manufacturing technology, specifically relating to a temperature control device and system for die casting of automotive aluminum-magnesium alloy parts. Background Technology

[0002] With the continuous advancement of automotive lightweighting trends, aluminum-magnesium alloys are increasingly widely used in automotive structural components due to their excellent properties such as low density and high specific strength. In the die-casting process of aluminum-magnesium alloy parts, the thermal equilibrium state of the mold directly determines the microstructure and macroscopic mechanical properties of the casting. Because aluminum-magnesium alloys have extremely high thermal conductivity and a narrow solidification window, they are highly sensitive to temperature fluctuations during the filling and solidification stages. Therefore, achieving precise temperature control of the die-casting mold is a crucial step in ensuring product yield.

[0003] In existing technologies, temperature control of die-casting molds mainly faces two specific technical bottlenecks.

[0004] First, there are insurmountable physical contradictions in temperature data acquisition (sensing layer). Traditional temperature measurement methods often employ surface mounting or thermocouples inserted into blind holes behind the mold frame. If surface mounting is used, the sensor is highly susceptible to damage under the impact of alloy hydraulic injection, which can reach pressures exceeding 100 MPa, and will leave obvious indentations on the casting surface. If deep-hole insertion temperature measurement is used, the unavoidable microscopic air gap between the sensor probe and the bottom of the blind hole creates significant contact thermal resistance, resulting in severe hysteresis in the acquired temperature signal. This delay and error in sensing prevent the control system from accurately and in real-time grasping the gradient relationship between the rapidly changing thermal pulses on the cavity surface and the heat accumulation deep within the mold frame.

[0005] Secondly, regarding temperature regulation (cooling layer), due to limitations of traditional mechanical drilling processes, cooling water channels can typically only be arranged in a straight line within the mold base. For complex automotive structural parts (such as those with deep cavities, narrow ribs, or thick wheel hubs), straight flow channels cannot penetrate or conform to these complex geometries, resulting in significant differences in cooling distances across the cavity surface. In continuous die casting cycles, because straight water channels create unreachable heat exchange dead zones, localized high-temperature "hot spots" easily form deep within the mold. This heat accumulation caused by fixed water channel trajectories not only disrupts the sequential solidification of the alloy liquid from the far end towards the gating system but also leads to the formation of isolated liquid phase regions, ultimately inevitably causing internal shrinkage cavities and porosity defects in thicker parts of the casting. Summary of the Invention

[0006] The purpose of this invention is to provide a temperature control device and system for die casting of automotive aluminum-magnesium alloy parts, which solves the problem of thermal imbalance caused by "temperature sensing lag" and "dead angle of linear cooling" in the existing die casting mold, thereby eliminating the problem of defects such as shrinkage cavities and porosity that are easy to occur inside complex and thick aluminum-magnesium alloy castings.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A temperature control device for die casting of automotive aluminum-magnesium alloy parts is applied to a die casting mold including a fixed mold and a moving mold. The fixed mold and the moving mold form a cavity inside the mold after closing. The temperature control device includes:

[0009] The layered temperature measurement module includes multiple temperature sensors disposed inside the die-casting mold, the multiple temperature sensors being distributed in the surface layer near the cavity, the subsurface layer near the gating, and the deep layer of the mold base.

[0010] A zoned heating module is disposed inside the fixed mold base and arranged circumferentially around the gating system;

[0011] A partitioned conformal cooling module includes conformal cooling channels disposed inside the fixed mold and the moving mold and distributed in accordance with the contour trajectory of the cavity; and

[0012] The main control unit has its signal input terminal electrically connected to the layered temperature measurement module, and its control output terminal connected to the zoned heating module and the zoned conformal cooling module, respectively.

[0013] Furthermore, the layered temperature measurement module includes temperature sensing points on the surface of the cavity, temperature sensing points on the subsurface of the gating system, and temperature sensing points deep within the mold frame.

[0014] Furthermore, the temperature sensing point on the surface of the cavity is achieved through an intelligent hollow ejector pin structure. The intelligent hollow ejector pin includes a hollow ejector pin body that moves through the moving mold base. A miniature thermocouple is inserted inside the hollow ejector pin body. The temperature sensing end of the miniature thermocouple is flush with the end face of the hollow ejector pin body that contacts the alloy liquid in the cavity.

[0015] Furthermore, a safety anti-erosion metal wall of preset thickness is provided between the bottom of the sensor mounting hole corresponding to the temperature sensing point on the subsurface of the gating and the inner wall of the gating. The mounting hole is filled with a high-temperature resistant thermally conductive medium, which wraps around the temperature sensing end of the sensor.

[0016] Furthermore, the sensor tail corresponding to the deep temperature sensing point of the mold frame is provided with an elastic pre-tightening mechanism, which presses the temperature sensing head of the sensor tightly against the bottom of the blind hole in the mold frame base.

[0017] Furthermore, the partitioned conformal cooling module also includes a water supply distributor and a water return collector disposed outside the mold. The inlet of the conformal cooling channel is connected to the water supply distributor, and the outlet of the conformal cooling channel is connected to the water return collector. An electromagnetic proportional regulating valve is provided between the water supply distributor and the main water supply pipe of the external constant temperature machine.

[0018] Furthermore, the branch outlet of the return water collector integrates an ultrasonic flow meter and a pressure sensor, and the signal output terminals of the ultrasonic flow meter and the pressure sensor are electrically connected to the main control unit.

[0019] Furthermore, the conformal cooling channel is formed inside the mold insert using laser selective melting additive manufacturing process, and the centerline trajectory of the conformal cooling channel and the normal distance to the cavity surface are constant.

[0020] Furthermore, the pipeline connecting the conformal cooling channel on the moving mold side to the external temperature control unit is laid inside the flexible cable chain, and the moving end of the flexible cable chain moves back and forth synchronously with the moving mold.

[0021] A temperature control system for die-casting automotive aluminum-magnesium alloy parts, utilizing the aforementioned temperature control device for die-casting automotive aluminum-magnesium alloy parts, the temperature control system comprising:

[0022] The preheating logic unit is used to control the zone heating module to compensate for heating of the gating area based on the feedback of the deep temperature sensing point of the mold frame before the injection begins.

[0023] A cooling control unit is used to dynamically adjust the opening of the electromagnetic proportional regulating valve based on real-time data from temperature sensing points on the cavity surface during the pressure holding and cooling stage; and

[0024] The status monitoring unit is used to determine the unobstructed status of the conformal cooling channel based on the flow rate and pressure data at the return water collector end.

[0025] The beneficial effects of this invention are:

[0026] 1. This invention utilizes a smart hollow ejector pin with a miniature thermocouple on the surface of the mold cavity, and welds the sensing end face flush with the surface for sealing. This achieves hysteresis-free temperature measurement within 50 milliseconds and effectively resists injection impacts and lateral shear forces exceeding 100 MPa. Simultaneously, an innovative elastic pre-tightening mechanism is introduced at the deep sensing point of the mold frame. This mechanism ensures a rigid, zero-gap surface contact between the sensing head and the bottom of the blind hole through continuous axial thrust, completely eliminating contact thermal resistance. The combination of these two features provides the main control unit with highly accurate, multi-level raw thermal field data.

[0027] 2. The cooling module of this invention abandons the traditional direct-flow water channel and adopts laser selective melting additive manufacturing process to form a conformal cooling channel. The three-dimensional trajectory of this channel maintains a constant normal distance from the surface of the complex cavity, completely eliminating the "thermal islands" in deep cavities that traditional direct-flow water channels cannot reach. Combined with the dynamic control of the proportional regulating valve by the main control unit, it can guide the alloy liquid to strictly follow the sequential solidification law, thus eliminating to a certain extent the hidden dangers of internal shrinkage cavities and porosity caused by localized heat accumulation in thick parts of automotive aluminum-magnesium alloy components.

[0028] 3. This invention addresses the high-frequency reciprocating motion of the moving mold by integrating the conformal cooling pipeline and shielded compensation wires into a flexible cable chain constraint layout, effectively preventing fatigue fracture of the pipeline. Simultaneously, an ultrasonic flow meter and pressure sensor are integrated at the return water end. By comparing the inverse abnormal changes in instantaneous flow rate and pressure difference, the main control unit can accurately diagnose scaling blockages or interface leaks inside the conformal flow channel online, avoiding batch product scrapping due to localized cooling failure and improving the long-term operational stability of the system. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments 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 these drawings without creative effort.

[0030] Figure 1 This is a cross-sectional schematic diagram of the internal structure of a temperature control device for die casting of automotive aluminum-magnesium alloy parts according to the present invention.

[0031] Figure 2 This is a detailed cross-sectional view of the core sensing end structure of the present invention;

[0032] Figure 3 This is a cross-sectional schematic diagram of the cavity-side intelligent hollow ejector pin temperature sensing structure of the present invention;

[0033] Figure 4 This is a schematic diagram of the steady-state temperature field distribution of a conventional through-cooling scheme under 0% heat load in the prior art.

[0034] Figure 5 This is a schematic diagram of the steady-state temperature field distribution of a conventional direct-flow cooling scheme under 100% heat load in the prior art.

[0035] Figure 6 This is a schematic diagram of the transient temperature field distribution under an initial thermal load of 560°C according to the present invention;

[0036] Figure 7 This is a schematic diagram of the transient temperature field distribution under an initial thermal load of 367°C according to the present invention;

[0037] Figure 8 This is a schematic diagram of the transient temperature field distribution under an initial thermal load of 85°C according to the present invention;

[0038] Figure 9 This is a logic flowchart of the temperature control system of the present invention. Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all 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.

[0040] To further verify the comprehensive temperature control effect of the multi-level sensing and zoned conformal cooling of the present invention, Figures 6 to 8 The temperature field evolution of the device of the present invention at different stages of a single die-casting cycle is demonstrated.

[0041] like Figure 6 As shown, in the initial stage of injection filling (when the system detects a transient thermal shock of up to 560°C), thanks to the preheating of the fixed mold side partition heating module, the sprue area maintains an ideal high heat value state. Figure 6 (Dark area on the left side of the middle section). This layout greatly reduces energy loss of the high-temperature alloy liquid at the inlet, ensures the filling activity of the front-end metal liquid, and prevents the generation of cold shut defects.

[0042] like Figure 7 As shown, as die casting enters the holding and cooling phase, the heat from the entire cavity begins to transfer to the mold base, and the overall temperature drops to approximately 367°C. At this point, the conformal cooling channels operate at full capacity under the control of the main control unit. (Observation) Figure 7 It can be seen that the thermal field distribution exhibits a high degree of uniformity, with a gentle temperature gradient between the central and peripheral regions, effectively suppressing the severe thermal stress concentration caused by uneven cooling.

[0043] like Figure 8 As shown, when the mold opening and ejection conditions are met at the end of the cooling cycle (the cavity temperature drops to a steady-state reference of approximately 85°C), the system thermal balance reaches an ideal state. This contrasts with the aforementioned prior art. Figure 5 It is evident that this invention completely eliminates the "hot spot island" in the deep cavity that traditional straight waterway cannot reach. Figure 8The "central temperature zone" is efficiently cooled by the conformal flow channel, achieving synchronous cooling with the surrounding areas (the figure shows a uniform low-temperature zone). This indicates that the alloy liquid completely follows the sequential solidification law from the far end to the gating channel, eliminating the hidden dangers of shrinkage cavities and porosity in thick parts, and improving the yield rate of automotive aluminum-magnesium alloy parts.

[0044] Example 1

[0045] This embodiment discloses a temperature control device for die casting of automotive aluminum-magnesium alloy parts. It is applied to a die casting mold including a fixed mold and a moving mold. After the fixed mold and the moving mold are closed, a cavity is formed inside. The temperature control device includes: a layered temperature measurement module, comprising multiple temperature sensors disposed inside the die casting mold, distributed on the surface near the cavity, the subsurface near the runner, and the deep layer of the mold base; a zoned heating module, disposed inside the fixed mold base and arranged circumferentially around the runner; a zoned conformal cooling module, comprising conformal cooling channels disposed inside the fixed mold and the moving mold and distributed according to the contour trajectory of the cavity; and a main control unit, whose signal input terminal is electrically connected to the layered temperature measurement module, and whose control output terminal is connected to the zoned heating module and the zoned conformal cooling module respectively. The layered temperature measurement module includes temperature sensing points on the cavity surface, subsurface of the runner, and deep layer of the mold base.

[0046] The temperature control device for die casting of automotive aluminum-magnesium alloy parts constructs an integrated control system from the local thermal field to the mold frame thermal field by comprehensively monitoring the internal temperature of the mold, accurately performing zoned compensation heating, and conformal active cooling. During the die casting process, aluminum-magnesium alloys are highly sensitive to temperature fluctuations due to their high thermal conductivity and short solidification window. Therefore, this embodiment adopts a layered and zoned design approach to completely solve industry pain points such as shrinkage cavities, cold shuts, air entrapment, and shortened mold life caused by mold thermal balance failure. Through the rational spatial layout and mutual coupling of the three functional modules—temperature sensing, heating, and cooling—the mold can be maintained within the set temperature range throughout complex production cycles.

[0047] In terms of mechanical structure, the die-casting mold used in this embodiment consists of a fixed mold base and a moving mold base. The fixed mold is fixed on the stationary platen of the die-casting machine and has a sprue inside to guide the molten aluminum-magnesium alloy liquid into the cavity. The moving mold is installed on the moving platen of the die-casting machine and moves back and forth with the opening and closing action of the die-casting machine. When the fixed mold and the moving mold are fully closed, the precisely machined concave contours inside them together close the forming cavity. The shape of the cavity is customized according to the required automotive aluminum-magnesium alloy parts. The temperature control device in this embodiment is designed based on this dynamic and static combined physical environment, and the main control unit realizes temperature control management of various monitoring areas and execution components.

[0048] The layered temperature measurement module arranges multiple temperature sensors in a tiered manner along the thickness direction of the mold.

[0049] The temperature sensing point on the cavity surface serves as the first level, with its sensor probe positioned within a thin area of ​​only 0.5 mm to 1.5 mm from the inner wall surface of the cavity. This level of setup allows for high-resolution capture of the thermal shock during the filling of the molten alloy and the subsequent cooling and solidification process, providing direct information for determining the optimal mold opening and ejection time. Because this location is extremely close to the high-temperature molten alloy, the sensor is typically a miniature armored thermocouple with a high response speed and a thermally insulating ceramic sheath to ensure it is not damaged by the instantaneous high temperature while sensing rapid thermal pulses.

[0050] The subsurface temperature sensing points of the gating system, as the second level, are distributed in the area near the gating system, typically at a depth of 5 to 10 millimeters from the gating wall. The main function of this level is to monitor the preheating status and cold material accumulation trend in the gating area. Since the gating system is the only channel for molten alloy to enter the mold cavity, even slight temperature changes directly affect the filling flow rate and fluidity of the aluminum-magnesium alloy. If the temperature at this location is too low, the molten alloy will solidify before entering the mold cavity, resulting in cold shut defects.

[0051] The deep temperature sensing points in the mold base serve as the third level, deeply embedded in the central region of the mold substrate, typically more than 30 millimeters from the molding surface. This level does not aim for high-frequency fluctuation response; its purpose is to monitor the heat accumulation in the mold substrate, i.e., the substrate temperature of the mold. As a large metal heat storage body, the stability of the deep thermal field within the mold determines the efficiency of subsequent cooling cycles.

[0052] Through these three layers of vertically distributed sensors, the main control unit can construct a three-dimensional thermal field distribution model, thereby determining whether the heat is conducted outward from the cavity or caused by excessive cooling leading to heat backflow.

[0053] The zoned heating module mainly consists of several groups of high-power-density electric heating tubes, which are vertically or horizontally embedded in the fixed mold base, close to the periphery of the sprue and runner. This zoned, circumferential arrangement ensures uniform runner wall temperature and avoids localized cold spots. During the preheating stage before the die-casting cycle begins, the main control unit supplies power to these heating tubes via the main circuit, generating significant Joule heat which is conducted to the runner wall, preheating the runner area to a predetermined temperature of approximately 250 to 300 degrees Celsius. This localized compensatory heating, combined with the overall mold temperature control preheating, significantly reduces energy loss of the molten alloy at the inlet, ensuring the molten metal at the front end maintains good filling activity. During production, if the main control unit detects excessive heat loss in a region through the subsurface temperature sensing point of the runner, it automatically increases the heating current of that zone for real-time heat replenishment.

[0054] To achieve rapid heat exchange response, the partitioned conformal cooling module adopts a conformal design that differs from traditional straight-through water holes.

[0055] like Figure 1 As shown in the actuator arrangement, the conformal cooling channel of the partitioned conformal cooling module exhibits a complex curved shape, with its inlet and outlet connected to the inlet at the top of the mold and the outlet at the bottom, respectively. This channel is formed using metal additive manufacturing (i.e., 3D printing), and its three-dimensional trajectory dynamically conforms to the complex geometry of the cavity, thus eliminating heat dissipation dead zones that traditional direct drainage channels cannot reach. This equidistant distribution ensures that the heat transfer distance from each cavity surface to the channel is consistent, thereby eliminating the heat dissipation problems caused by uneven wall thickness in traditional cooling methods.

[0056] In this embodiment, these conformal flow channels with complex curved shapes are formed simultaneously during the mold insert processing using a metal additive manufacturing process, namely laser selective melting technology. Inside the flow channels, the cooling medium is typically softened circulating water or high-temperature heat transfer oil. The main control unit controls the flow rate of each zone flow channel by adjusting the opening of an external proportional control valve. This zoned control capability allows the system to provide powerful forced cooling to the thicker central areas of automotive parts, while providing moderate cooling or natural cooling to the thin-walled edge areas. This guides the alloy liquid to solidify sequentially from the far end towards the gating system, which is significant for eliminating shrinkage cavities and porosity inside the casting.

[0057] The main control unit, acting as the brain of the entire system, employs a programmable logic controller (PLC) as its computing core. It features multiple high-speed analog input interfaces and a pulse-width modulation (PWM) output interface. The main control unit receives temperature signals from three depth levels via shielded compensation wires, and after internal signal filtering and analog-to-digital conversion, analyzes the mold's thermal balance in real time. The main control unit has a pre-set PID control algorithm tailored to the characteristics of aluminum-magnesium alloys. This algorithm automatically calculates the energy supply required for each zone's heating module and conformal cooling module based on a preset temperature control curve. When the temperature at the surface sensing point of the cavity reaches the set solidification endpoint, the main control unit immediately outputs a command to cut off the corresponding cooling circuit and sends a mold-opening signal. Furthermore, the main control unit has data diagnostic capabilities. By analyzing the temperature gradient between the deep and surface sensing points, it assesses the thermal stress level inside the mold and dynamically fine-tunes the cooling strategy accordingly. This ensures production cycle time while maximizing mold protection against thermal fatigue cracks.

[0058] In practical operation of this embodiment, technicians first need to determine the areas with the highest and lowest heat loads through numerical simulation based on the structural characteristics of the automotive aluminum-magnesium alloy parts to be produced. Then, following the spatial arrangement principles described in this embodiment, mounting holes are machined at corresponding positions in the fixed and moving molds, and the layered temperature sensors and heating tubes are embedded accordingly. The inserts for the conformal cooling channels need to be pre-processed using 3D printing equipment and undergo airtightness pressure testing before being press-fitted into the mold base. All sensor leads and power lines must be led out to the main control unit through dedicated wiring channels. After system startup, the main control unit will first activate the zoned heating module to preheat the mold until the deep temperature sensing point of the mold frame reaches a stable value. During the injection process, the system automatically switches to real-time monitoring mode, directing the cooling medium to circulate or shut off within the channels based on the collected surface, subsurface, and deep temperatures. Through this precise linkage of multi-level sensing and zoned execution, those skilled in the art can achieve closed-loop control of the complex die-casting thermal process.

[0059] Example 2

[0060] This embodiment discloses a temperature control device for die casting of automotive aluminum-magnesium alloy parts. It is applied to a die casting mold including a fixed mold and a moving mold. After the fixed mold and the moving mold are closed, a cavity is formed inside. The temperature control device includes: a layered temperature measurement module, comprising multiple temperature sensors disposed inside the die casting mold, distributed on the surface near the cavity, the subsurface near the runner, and the deep layer of the mold base; a zoned heating module, disposed inside the fixed mold base and arranged circumferentially around the runner; a zoned conformal cooling module, comprising conformal cooling channels disposed inside the fixed mold and the moving mold and distributed to conform to the contour trajectory of the cavity; and a main control unit, whose signal input terminal is electrically connected to the layered temperature measurement module, and whose control output terminal is connected to the zoned heating module and the zoned conformal cooling module respectively. The temperature sensing points on the surface of the mold cavity are achieved through an intelligent hollow ejector pin structure. The intelligent hollow ejector pin includes a hollow ejector pin body that moves through the moving mold base. A miniature thermocouple is inserted inside the hollow ejector pin body, and the sensing end of the miniature thermocouple is flush with the end face of the hollow ejector pin body that contacts the molten alloy in the mold cavity. A safety, anti-erosion metal wall of preset thickness is provided between the bottom of the sensor mounting hole corresponding to the subsurface temperature sensing point of the gating system and the inner wall of the gating system. The mounting hole is filled with a high-temperature resistant thermally conductive medium, which wraps around the sensing end of the sensor. An elastic pre-tightening mechanism is provided at the tail of the sensor corresponding to the deep temperature sensing point of the mold base, pressing the sensor's sensing head tightly against the bottom of the blind hole in the mold base base.

[0061] In the die-casting process of aluminum-magnesium alloys, the reliability of the mold sensing end directly determines the effectiveness of the temperature control system. Especially when dealing with materials like ADC12 aluminum alloy or AZ91D magnesium alloy, which have high fluidity and drastic fluctuations in filling pressure, ordinary surface-mount or blind-hole insertion sensors are prone to failure due to mechanical impact, thermal fatigue, or signal lag. This embodiment constructs a physical sensing layer capable of withstanding injection impacts exceeding 120 MPa and possessing millisecond-level response capabilities by deploying sensors with specific mechanical structures deep within the mold cavity, runner, and mold base. This solution addresses extreme conditions such as frequent opening and closing of the die-casting mold, severe vibration of the mold base, and high-speed scouring of molten metal at the gate. Through three unique installation methods—hollow ejector pins, thick-walled conduction, and elastic locking—it ensures the linearity and repeatability of the thermoelectric conversion signal, thus providing a physical basis for the subsequent main control unit to adjust the proportional valve flow rate and heating power.

[0062] Regarding the arrangement of temperature sensing points on the surface of the moving mold cavity, such as Figure 3The diagram shown is a cross-sectional schematic of the intelligent hollow ejector pin temperature-sensing structure on the cavity side of this invention. In this embodiment, a hollow ejector pin serves as the temperature-sensing carrier, movably positioned within the moving mold base. The thermocouple wire passes through the hollow hole of the ejector pin, with its sensing end flush with the end face of the ejector pin that contacts the molten alloy in the overflow groove. This structure, while achieving the ejection function, eliminates temperature hysteresis and can capture transient temperature change signals during the solidification stage of the molten alloy in real time.

[0063] In terms of structural details, the central aperture of the hollow ejector pin is precisely fitted with the outer diameter of the thermocouple wire. Crucially, the temperature-sensing end of the thermocouple wire is sealed and fixed to the working end face of the hollow ejector pin via laser circumferential welding or high-precision laser cladding. This sealing structure physically forms a high-strength pressure barrier, ensuring that when facing extremely high injection pressures exceeding 100 MPa during injection, the molten aluminum-magnesium alloy can only exchange heat with the ejector pin end face and cannot flow back into the ejector pin or behind the mold frame through the central aperture. Furthermore, the flush encapsulation design of the temperature-sensing end and the ejector pin end face not only eliminates temperature measurement lag but also ensures that the temperature-sensing end will not be displaced or damaged by lateral shear forces during component ejection, guaranteeing the structural integrity of the sensing layer during dynamic reciprocating cycles.

[0064] Combination Figure 3 The cross-sectional features further illustrate that the working end of the hollow ejector pin extends into the cavity of the overflow groove. It should be noted that the overflow groove is a pre-set accommodating cavity when the mold is closed and not being injected; however, during the injection and pressure holding stage, the overflow groove is filled with molten alloy to be solidified. Figure 3 The shaded area on the left represents the molten alloy filling the overflow groove, while the slanted area on the right represents the mold base. The temperature sensing end directly abuts against the boundary of the molten alloy in the overflow groove. This arrangement ensures that the measured temperature signal can directly reflect the thermal state of the molten alloy at the end of the flow path in the cavity, thus providing the main control unit with the most up-to-date raw data for determining the venting effect and the solidification endpoint.

[0065] This solution avoids the conventional practice of directly drilling holes in the precision molding surface, as this would damage the surface finish of the casting and leave obvious temperature-sensing end marks on the component surface. This embodiment uses a hollow ejector pin body as the carrier of the temperature-sensing element. This hollow ejector pin body slides back and forth within the moving mold base, its function physically coupling demolding ejection with real-time temperature measurement. A through-hole micro-hole is machined at the center of the hollow ejector pin body, the inner diameter of which is determined by the outer diameter of the miniature thermocouple, typically a 0.5 mm diameter K-type armored thermocouple. The temperature-sensing end of the miniature thermocouple is flush with and sealed to the top plane of the hollow ejector pin body using high-temperature laser micro-hole welding. This ensures that when the end face comes into contact with molten alloy at 650°C to 700°C, the molten metal will not seep into the ejector pin, causing a short circuit in the sensor. Because the temperature-sensing end is directly exposed to the cavity environment, its temperature response time is controlled within 50 milliseconds, enabling complete capture of the instantaneous thermal peak during filling. This structure utilizes the original ejector pin holes in the mold, enabling direct measurement of the dynamic changes in the innermost thermal field of the cavity without increasing the complexity of the mold structure.

[0066] Temperature sensing in the gating area on the fixed mold side faces the risk of physical erosion. The flow velocity of the molten alloy at the gating inlet can reach 40 meters per second. If the sensor is embedded too shallowly, the steel in the thin-walled section will develop thermal fatigue cracks or even be punctured after thousands of injection cycles. This embodiment adopts a subsurface embedding scheme on the gating side, machining sensor mounting holes on the back of the fixed mold substrate, and maintaining a 3.5 mm to 5.0 mm safety anti-erosion metal wall between the bottom of the hole and the inner wall of the gating. Although this thickness of H13 mold steel will generate some thermal resistance, this scheme compensates for this hysteresis by forcibly filling the mounting hole with a high-temperature resistant thermally conductive medium. The high-temperature resistant thermally conductive medium is a thermally conductive paste formulated with micron-sized copper powder and high-temperature resistant synthetic oil, whose thermal conductivity is much higher than that of air. The sensing end of the miniature thermocouple is tightly wrapped in the thermally conductive medium, which completely eliminates the microscopic air gap between the probe and the bottom of the hole, allowing heat to be quickly conducted from the inner wall of the gating through the safety anti-erosion metal wall to the probe. This design ensures that the main control unit can monitor the preheating temperature of the gate in real time while guaranteeing the strength of the mold in the gating area, effectively preventing the problem of aluminum liquid cooling and crusting caused by excessively low gate temperature.

[0067] The setting of deep temperature sensing points in the mold base focuses on monitoring the overall heat distribution of the mold base. Since this position is far from the cavity, it is less affected by thermal shock. However, the 5g to 10g mechanical vibration generated during the high-speed mold closing and ejection process can easily cause the sensor to be axially displaced in the deep hole, causing the temperature sensing head to detach from the bottom of the hole, thus resulting in serious temperature measurement errors.

[0068] To address this issue, this embodiment integrates an elastic pre-tensioning mechanism at the sensor's tail, such as... Figure 2The diagram shown is a detailed cross-sectional view of the core sensing end structure of this invention, highlighting the elastic pre-tightening installation structure of the deep temperature sensing point in the mold frame.

[0069] In terms of mechanical connection, the armored thermocouple is deeply embedded inside a blind hole in the mold base. To overcome the axial displacement of the sensor caused by the high-frequency vibration of the die-casting machine, this solution has a fixed seat threaded or bolted at the opening of the blind hole, and a heat-resistant spring is pressed between the fixed seat and the tail of the armored thermocouple.

[0070] In the installed state, the mounting bracket restricts the outward displacement of the heat-resistant spring, forcing the spring into a compressed state and releasing a continuous axial thrust (typically 20N to 50N). This elastic preload is transmitted axially along the armored thermocouple, forcing the front end of the armored thermocouple to press firmly against the bottom of the blind hole.

[0071] The engineering significance of this mechanical structure lies in the fact that, through the dynamic compensation of the spring, it ensures that the sensing end of the armored thermocouple maintains a rigid, zero-gap contact with the bottom of the blind hole when the mold experiences severe thermal expansion and contraction or mechanical vibrations of 5g to 10g. This completely eliminates the microscopic air thermal resistance layer at the bottom of the blind hole, creating an extremely low-delay solid heat conduction channel between the metal mold frame and the temperature sensing element, thereby ensuring that the main control unit can obtain the true body temperature of the deep layers of the mold frame in real time and with precision.

[0072] The elastic pre-tightening mechanism includes a pre-compressed heat-resistant spring and a fixing seat. The fixing seat is located at the opening of the blind hole in the mold base. The heat-resistant spring is constrained between the fixing seat and the tail of the sensor. The fixing seat limits the spring to maintain a pre-compressed state, thereby generating a continuous axial pressure pointing towards the bottom of the hole. The fixing seat is located on the outermost structural surface of the mold base, that is, at the opening of the sensor mounting hole. It is fixed to the mold base by mechanical locking, sealing the opening of the blind hole.

[0073] During installation, the spring provides a continuous axial thrust of 20 to 50 Newtons, firmly pressing the temperature sensor against the bottom of the blind hole in the mold base. Even if the mold base experiences severe vibrations during continuous production or undergoes slight deformation due to thermal expansion and contraction, the temperature sensor maintains zero-gap contact with the bottom of the metal hole. For signal transmission, the microvolt-level signal output by the sensor is led out through a shielded compensating wire, which is protected by a stainless steel corrugated tube to prevent aluminum splashing or mechanical wear.

[0074] Heat conduction process: The molten aluminum in the cavity releases heat, which passes through the thick mold steel and reaches the blind hole end face. Relying on the spring thrust and the heat conduction medium, the heat crosses the interface and enters the sensor's armor shell. The heat is then transferred to the internal thermocouple wire (such as the nickel-chromium / nickel-silicon end of a K-type thermocouple wire), generating a thermoelectric electromotive force.

[0075] The physical implementation of this temperature control device requires strict assembly procedures. Technicians first use deep-hole drilling and precision wire cutting to machine the corresponding temperature-sensing holes on the base of the fixed and moving molds, with the hole diameter accuracy controlled within ±0.02 mm. Before installing the hollow ejector pin body into the moving mold ejector plate, the internal thermocouple must be encapsulated and calibrated. Before installing the sensor in the gating area, a specific amount of heat-conducting medium must be injected into the bottom of the hole using a special syringe, and the overflow state of the medium after probe insertion must be observed to ensure full filling. The compression amount of the elastic preload mechanism needs to be preset according to the mold's closing stroke to prevent insufficient or excessive preload from damaging the sensor lead root.

[0076] Example 3

[0077] This embodiment discloses a temperature control device for die casting of automotive aluminum-magnesium alloy parts. It is applied to a die casting mold including a fixed mold and a moving mold. After the fixed mold and the moving mold are closed, a cavity is formed inside. The temperature control device includes: a layered temperature measurement module, comprising multiple temperature sensors disposed inside the die casting mold, distributed on the surface near the cavity, the subsurface near the runner, and the deep layer of the mold base; a zoned heating module, disposed inside the fixed mold base and arranged circumferentially around the runner; a zoned conformal cooling module, comprising conformal cooling channels disposed inside the fixed mold and the moving mold and distributed to conform to the contour trajectory of the cavity; and a main control unit, whose signal input terminal is electrically connected to the layered temperature measurement module, and whose control output terminal is connected to the zoned heating module and the zoned conformal cooling module respectively. The partitioned conformal cooling module also includes a water supply distributor and a water return collector located outside the mold. The inlet of the conformal cooling channel is connected to the water supply distributor, and the outlet of the conformal cooling channel is connected to the water return collector. An electromagnetic proportional regulating valve is provided between the water supply distributor and the main water supply pipe of the external constant temperature machine. The branch outlet of the water return collector integrates an ultrasonic flow meter and a pressure sensor, and the signal output terminals of the ultrasonic flow meter and pressure sensor are electrically connected to the main control unit. The conformal cooling channel is formed inside the mold insert using laser selective melting additive manufacturing process, and the distance between the centerline trajectory of the conformal cooling channel and the normal distance to the surface of the cavity is a constant value.

[0078] To address the issue that thick sections in automotive aluminum-magnesium alloy parts are prone to heat spots and shrinkage defects, the partitioned conformal cooling module in this embodiment aims to solve the problems of low heat exchange efficiency and lack of monitoring in traditional drilling water circuits.

[0079] like Figure 4The diagram shows the temperature field distribution of a conventional straight-through cooling system under 0% initial heat load. In this system, the cooling channels can only be arranged in a straight line within the mold base. Limited by traditional mechanical drilling processes, the channels cannot penetrate deep into or conform to the deep cavities and corners of the mold cavity. After several injection cycles with an initial heat load of 0% (i.e., the baseline state at the start of the simulation), due to the existence of heat exchange dead zones deep within the mold, heat will accumulate at the bottom of the cavity (…). Figure 4 A distinct hot spot region (indicated by the central indicator area) forms in this area. The heat in this region cannot be effectively dissipated by the surrounding cooling medium, leading to severe internal shrinkage cavities in the molten aluminum-magnesium alloy during solidification.

[0080] Furthermore, such as Figure 5 The diagram shows the steady-state temperature field distribution of a conventional straight-through cooling system under 100% heat load. When the die-casting mold enters the continuous production stage and reaches 100% heat load (i.e., steady-state condition), the conventional straight-through cooling pipes cannot penetrate deep into the geometric center of the bottom of the cavity, resulting in a very significant high-temperature hot spot in that area.

[0081] Simulation results show that the cooling medium can only remove heat from the sides of the mold frame near the direct water channel. Figure 5 The low-temperature zones on both sides of the cavity, while the center of the cavity experiences severe physical heat accumulation due to the excessive heat exchange distance (usually exceeding 30mm). Figure 5 (Dark high-heat value indicator area at the bottom center). This thermal field distribution not only prevents the aluminum-magnesium alloy liquid from solidifying sequentially from the far end to the gating system, but also forms independent liquid islands at hot spots, ultimately resulting in uncontrollable shrinkage cavities and porosity defects inside the casting.

[0082] The latent heat generated during the die casting process of aluminum-magnesium alloys is released extremely rapidly. Conventional straight-line deep-hole water channels, due to limitations in machining processes, cannot reach the deep slopes or corners of the mold cavity, resulting in the mold temperature in these areas remaining at ultra-high temperatures above 320°C for extended periods, thus delaying the sequential solidification process of the alloy liquid. This embodiment transforms the cooling process hidden deep within the mold into a transparent, real-time monitorable and adjustable process through digital execution. The system architecture relies on high-precision metal additive manufacturing flow channels, a water distributor assembly with digital feedback, and health diagnostic logic based on pressure and flow dual parameters, achieving a structural upgrade from the actuator to a closed-loop sensing system.

[0083] The conformal cooling channel forming process is fundamental to achieving equidistant heat dissipation. In traditional processes, water-cooling channels on the mold base are often machined by radial drilling machines or CNC machining centers, with paths limited to straight lines and distances from the cavity surface fluctuating between 15mm and 45mm. This uneven wall thickness results in significant differences in cooling gradients across the cavity surface, with thin-walled areas prone to rapid cooling and thick-walled areas experiencing heat accumulation. In this embodiment, the conformal cooling channel employs selective laser melting (SLM) technology, using maraging steel MS1 powder as the substrate. This material achieves a hardness exceeding 50 HRC after heat treatment. The channel's inner diameter is set to 8mm, and its three-dimensional trajectory maintains a constant normal distance of 10mm from the complex geometry of the cavity surface during the modeling stage using an offset algorithm. The advantage of this structure is that even in complex areas with deep cavities or narrow ribs in automotive parts, the channel can adhere closely to the surface like a blood vessel, increasing the heat exchange area by more than 45% compared to traditional straight water channels. The inner wall of the flow channel retains a certain degree of original sintering roughness, with Ra controlled between 15μm and 25μm. This is not due to processing limitations, but rather a proactively designed feature to enhance heat transfer. The rough inner wall of the flow channel effectively breaks the boundary layer as the fluid flows through, inducing strong turbulence in the heat transfer medium at lower pump pressures, resulting in a Reynolds number Re exceeding 4000. The reason for not using a composite manufacturing scheme with embedded pure copper tubes is that the physical gap between pure copper and steel components would create significant thermal resistance, and the copper tubes are prone to interfacial delamination under long-term vibration cycles exceeding 1000 times / hour in the mold. The SLM integral molding technology, however, ensures the continuity of the heat transfer medium and the structural integrity.

[0084] The digital connection between the externally integrated water distributor and the execution unit ensures the distribution of flow. This embodiment abandons the traditional fully open / fully closed ball valve and instead installs an electromagnetic proportional regulating valve on each independent branch of the water supply distributor. These regulating valves receive a 4-20mA analog signal output from the main control unit and can precisely control the valve core opening between 0% and 100%. At different stages of the die-casting cycle, the main control unit dynamically adjusts the medium flow rate of each conformal water tank based on the cavity temperature rise rate fed back by the layered temperature measurement module. For example, in the pressure holding stage after filling, the proportional valve is fully open in the water circuit of the thick-walled hub area to output the maximum heat exchange power; while in the thin-walled flange area, the valve core opening is reduced to prevent a sudden drop in local mold temperature. The water supply distributor and the return water collector are completely isolated in physical space and are arranged on the side walls of the moving and fixed molds, respectively. The main water supply pipe connecting the two is externally connected to a constant temperature machine, and the system uses pressurized softened water as the medium. To prevent the heat exchange efficiency from decreasing due to internal scaling in the conformal flow channel, a water softening device is connected to the front end of the system to forcibly reduce the calcium and magnesium ion hardness to below 50 mg / L.

[0085] The flow and pressure monitoring system at the return water collector end constitutes a closed-loop health diagnosis system for conformal water channels. Due to their narrow diameter and numerous bends, conformal flow channels are highly susceptible to physical blockage caused by impurities or scale buildup, which is difficult to detect with traditional temperature controllers and pressure gauges. In this embodiment, an ultrasonic flow meter and pressure sensor are integrated at the end of the return water branch in each zone. The ultrasonic flow meter uses an externally mounted structure, avoiding contact with high-temperature media and eliminating the risk of corrosion. The main control unit compares the instantaneous flow rate Q with the inlet and outlet pressure difference ΔP in real time within the same flow channel. If the monitoring data shows a continuous decrease in the Q value while ΔP abnormally increases, the system automatically identifies and alerts the system to physical blockage or scaling in the flow channel of that zone. This diagnostic scheme based on dual-parameter coupling is superior to single flow monitoring because pressure feedback effectively eliminates false alarms when water temperature increases leading to viscosity changes. Conversely, if the Q value increases while ΔP decreases, it is determined that the sealing of the insert interface inside the mold has failed or the flow channel has cracked and leaked water. The main control unit will immediately interlock and shut down the main pump of the thermostat to prevent high-pressure cold water from being injected into the high-temperature cavity being filled and causing a safety accident.

[0086] In practical applications, technicians must conduct a 1.5MPa pressure test and leak check on the 3D printed inserts before installing the conformal cooling module, and then install high-temperature fluororubber O-rings at the interfaces. During pipe connection, the markings on the inlet and outlet must strictly correspond. The circulating pressure output by the thermostat is set between 4 bar and 6 bar. Due to the strong heat exchange capacity of the conformal flow channel, during the initial mold preheating stage of production, the main control unit will reduce the proportional valve opening to 20%, achieving a slow and uniform temperature rise through low-speed hot water circulation to prevent premature thermal fatigue of the conformal inserts due to excessive temperature differences. During production, if the ultrasonic flow meter detects that the single-channel flow fluctuation exceeds the preset 15% threshold, the system will automatically initiate backflushing logic, briefly fully opening the proportional valve and switching to high-pressure airflow for flushing. Through this technical approach, from internal conformal design to precise external adjustment and end-point health monitoring, those skilled in the art can maintain the mold temperature field within an extremely narrow dynamic range of ±5°C.

[0087] Here's some clarification regarding 3D-printed inserts. These inserts aren't made of ordinary iron, but rather using specialized hot-work die steel powder, such as 1.2709 maraging steel, whose performance even surpasses that of traditional H13 steel. Molten aluminum has a melting point of approximately 600°C-700°C, while the melting point of 3D-printed die steel is 1400°C-1500°C. The biggest advantage of 3D printing is its ability to create "internal cavities" that traditional machining cannot produce. These cavities act as cooling water channels, continuously carrying away heat from the cavity surface. With this "water-cooled outer shell," the actual surface temperature of the insert is suppressed to around 200°C-300°C, far below its softening temperature.

[0088] Example 4

[0089] This embodiment discloses a temperature control device for die casting of automotive aluminum-magnesium alloy parts. It is applied to a die casting mold including a fixed mold and a moving mold. After the fixed mold and the moving mold are closed, a cavity is formed inside. The temperature control device includes: a layered temperature measurement module, comprising multiple temperature sensors disposed inside the die casting mold, distributed on the surface near the cavity, the subsurface near the runner, and the deep layer of the mold base; a zoned heating module, disposed inside the fixed mold base and arranged circumferentially around the runner; a zoned conformal cooling module, comprising conformal cooling channels disposed inside the fixed mold and the moving mold and distributed to conform to the contour trajectory of the cavity; and a main control unit, whose signal input terminal is electrically connected to the layered temperature measurement module, and whose control output terminal is connected to the zoned heating module and the zoned conformal cooling module respectively. The temperature sensing point on the surface of the cavity is achieved through an intelligent hollow ejector pin structure. The intelligent hollow ejector pin includes a hollow ejector pin body that moves through the moving mold base. A miniature thermocouple is installed inside the hollow ejector pin body, and the sensing end of the miniature thermocouple is flush with the end face of the hollow ejector pin body that contacts the molten alloy inside the cavity. The pipeline connecting the conformal cooling channel on the moving mold side to the external temperature control unit is laid inside a flexible cable chain. The moving end of the flexible cable chain moves back and forth synchronously with the moving mold.

[0090] To address the operational reliability under dynamic conditions on the moving mold side, this embodiment solves the problem of physical wear and tear on pipelines and sensors caused by frequent impacts during the opening and closing of the die-casting machine through mechanical structure coupling and motion trajectory constraints.

[0091] When the die-casting cycle time of aluminum-magnesium alloy parts is controlled between 45 and 60 seconds, the moving mold base and its ejector plate need to complete 60 to 80 linear reciprocating movements per hour, with a stroke typically between 400 and 600 mm. If conventional suspended wiring is used, the sensor wires will experience metal fatigue fracture within a short period, and the cooling pipes are prone to friction with the die-casting machine column, leading to media leakage. This solution addresses the special dynamic environment of the moving mold side by integrating temperature-sensing nerve endings inside the reciprocating hollow ejector body, and utilizing a flexible cable chain that combines rigidity and flexibility to construct a pipeline protection channel, ensuring continuous physical performance of signal transmission and cooling medium circulation during more than 100,000 motion cycles.

[0092] The structural design of the intelligent hollow ejector pin is the core technology for real-time sensing on the moving mold side. It not only undertakes the mechanical task of ejecting the casting but also serves as a carrier of high-frequency thermoelectric signals. The hollow ejector pin body is made of hot-work die steel H13 with a hardness of 48HRC to 52HRC, and its center hole diameter is machined to 1.2mm. The inner micro-thermocouple has an outer diameter of 1.0mm and is a K-type armored probe. To prevent molten alloy from seeping into the ejector pin through the pores when the injection pressure exceeds 120MPa, the temperature-sensing end of the micro-thermocouple is fixed to the top center of the hollow ejector pin body using laser spot welding, and the end face remains flush. This structure avoids drilling additional temperature-sensing blind holes on the mold cavity surface and utilizes the original ejector plate's reciprocating movement. Wireless radio frequency transmission technology is not used because the die-casting workshop contains numerous frequency converters and high-current motors, and the aluminum-magnesium alloy liquid has a strong shielding effect on electromagnetic waves, making it impossible for wireless signals to penetrate stably inside the closed mold. Guided by physical wiring, the sensor signal is led out from the tail of the ejector pin to the back of the ejector pin fixing plate. This position is in the relatively static area of ​​the moving mold base, which greatly alleviates the stress concentration of the root wire.

[0093] The overall laying path of the pipelines and wires adopts a layered aggregation and flexible constraint strategy. The conformal cooling channels connected to the moving mold side involve multiple inlet and outlet water pipes. These pipes are made of PTFE high-pressure flexible hoses lined with stainless steel braided mesh. If ordinary rubber hoses are used, the rubber will age and become brittle rapidly when in contact with hot oil or hot water above 150°C, and cannot withstand high-frequency bending. All main pipes, return pipes, and shielded compensation wires of the conformal cooling channels are uniformly converged to the interface panel on the side of the moving mold base, and then enter the flexible cable chain. The flexible cable chain is made of flame-retardant reinforced nylon material, and its bending radius R is set to 100mm. The reason for setting this radius is that if the radius is less than 80mm, the internally laid shielded compensation wires will experience resistance drift due to excessive bending stress, affecting the accuracy of temperature measurement. If the radius is greater than 150mm, it will cause the cable chain to swing and collide when the moving mold retracts to its limit position. The fixed end of the flexible cable chain is fastened to the electrical cabinet frame on the stationary side of the die-casting machine, and the moving end is fastened to the moving mold follower template.

[0094] During the mold opening process, the moving end moves back and forth synchronously with the moving mold, and the pipelines inside the cable chain are arranged in a U-shape and unfolded in an orderly manner. This solution abandons the cantilevered installation of pipelines because the cantilever structure will sway violently during rapid movement, and the roots of the conductors are prone to cold work hardening and eventual breakage. Through the constraint of the cable chain, the conductors and pipelines only undergo controlled bending in the vertical plane, eliminating torsional stress. To isolate signal interference, the compensating conductors adopt a metal braided shielding layer and are grounded at one end at the main control unit.

[0095] The conformal cooling channels utilize high-temperature resistant adapters at their connections within the moving mold. Heat exchange requirements on the moving mold side are typically concentrated around the overflow channel and ejector pin holes. An arc-shaped conformal cooling channel, pre-installed within the moving mold insert using the SLM process, has its inlet and outlet pipes led to the back of the moving mold via rigid tubes, and then connected to a flexible pipeline within the cable chain via quick-connect couplings. This design prioritizes ease of mold maintenance; when ejector pins need replacement or cavity adjustments are required, operators only need to disconnect the quick-connect couplings without disassembling the entire cable chain system. To address potential liquid splashing issues during aluminum-magnesium alloy die casting, the cable chain employs a fully enclosed structure to prevent fine aluminum slag from falling into the chain and damaging the cable sheath. This protective logic is based on trial-and-error conclusions from long-term front-line production, avoiding electrical short-circuit faults caused by dust and metal shavings.

[0096] When implementing this solution, those skilled in the art need to determine the length of the flexible cable chain based on the maximum mold opening stroke of the die-casting machine, with a allowance typically 20% of the stroke. When the hollow ejector pin body is installed into the moving mold base, axial coaxiality must be checked to ensure that the miniature thermocouple does not experience squeezing friction with the hole wall during continuous movement. Appropriate slack should be reserved for the wires before they enter the cable chain to prevent the shielding layer from tearing due to stress overload under extreme stretching conditions. The signal acquisition module needs to be equipped with a self-diagnostic program to monitor the loop resistance of the compensation wires in real time. Once the resistance abnormally rises above the preset range, the system will determine that the pipeline has suffered fatigue damage and issue a warning.

[0097] Example 5

[0098] like Figure 9 The diagram shown is a logic flowchart of the temperature control system of this invention. This embodiment relates to a temperature control system for die-casting automotive aluminum-magnesium alloy parts. Through a preheating logic unit, a cooling control unit, and a status monitoring unit integrated within the main control unit, the system converts multi-dimensional thermal field data collected by the layered temperature measurement module into millisecond-level scheduling commands for the actuators. Addressing the extremely unbalanced heat exchange characteristic of AZ91D magnesium alloy or similar aluminum alloy die-cast parts during a 45-second production cycle, combined with… Figure 9 As can be seen from the process branches, the core logic of the system presents a parallel and collaborative architecture from preheating preparation, dynamic cooling to status monitoring:

[0099] First, during the mold preparation stage before injection begins, the preheating logic unit monitors the heat accumulation status of the mold substrate through deep temperature sensing points on the mold base (typically set to a reference temperature of 180 degrees Celsius). If the deep temperature is below 150 degrees Celsius, the system determines that the mold is in a "cold mold" state, at which point the zone heating module is forcibly activated for high-power compensation heating; if the temperature is normal, injection filling is performed directly (entering an initial thermal load of 560 degrees Celsius).

[0100] Secondly, after the alloy liquid is filled and enters the pressure holding and cooling stage, the core of the temperature control system switches to the cooling control unit. At this time, the temperature rise status is acquired in real time through temperature sensing points on the surface of the cavity, and the opening of the proportional valve is dynamically adjusted according to the temperature. The cooling control unit implements a precise braking strategy. When the surface temperature reaches the preset solidification endpoint threshold of 430 degrees Celsius, a judgment is immediately triggered, the cooling circuit is cut off, and an ejection command is issued to prevent overcooling from causing damage.

[0101] Meanwhile, the status monitoring unit operates in parallel in the background. Utilizing the ultrasonic flow meter and pressure sensor integrated at the return water collector, it monitors the branch flow (Q) and pressure (P) in real time. If the system determines that Q and P are in opposite directions (e.g., a decrease in flow and an increase in pressure indicate blockage, or an increase in flow and a decrease in pressure indicate leakage), it immediately executes an alarm or interlock shutdown to ensure the operational health of the conformal flow channel.

[0102] This embodiment relates to a temperature control system for die-casting automotive aluminum-magnesium alloy parts. Through a preheating logic unit, cooling control unit, and status monitoring unit integrated within the main control unit, multi-dimensional thermal field data collected by the layered temperature measurement module is converted into millisecond-level scheduling commands for the actuators. Addressing the extremely unbalanced heat exchange characteristic of AZ91D magnesium alloy or similar aluminum alloy die-casting parts during a 45-second production cycle, the core logic of the system utilizes temperature feedback at different depths to refine the mold's macroscopic heat capacity management into localized transient thermal field intervention. During the mold preparation stage before injection, the preheating logic unit monitors the heat accumulation state of the mold substrate through deep temperature sensing points on the mold frame, typically setting the substrate reference temperature to 180 degrees Celsius. If the deep temperature is below 150 degrees Celsius, the system determines that the mold is in a cold mold state. At this time, the preheating logic unit forcibly activates the zoned heating module to provide high-power compensation heating to the gating area, preventing the alloy liquid above 600 degrees Celsius from being rapidly cooled upon contact with the cold walls before entering the cavity.

[0103] After the alloy melt is filled and enters the pressure holding and cooling stage, the core of the temperature control system switches to the cooling control unit. At this time, the temperature sensing point on the cavity surface monitors the latent heat release during the solidification process of the alloy melt in real time through an intelligent hollow ejector pin structure with a sampling period of 100 milliseconds. When the AZ91D magnesium alloy melt is in the two-phase region of 470 degrees Celsius to 595 degrees Celsius, the cooling control unit adjusts the opening of the electromagnetic proportional regulating valve through a proportional control algorithm. For the conformal cooling channel corresponding to the thick-walled area, the proportional valve opening is set to 80% to 100% to maintain the turbulent state of the heat exchange medium in the channel. The system abandons the constant flow cooling scheme because a constant flow will cause overcooling in the thin-walled area, generating huge internal stress and causing casting deformation. The cooling control unit implements a precise braking strategy, that is, when the temperature sensing point on the cavity surface drops to the preset solidification endpoint threshold of 430 degrees Celsius, it immediately instructs the electromagnetic proportional regulating valve to close to a 5% maintenance opening to prevent the mold temperature from dropping further below 150 degrees Celsius. Without this intervention, excessive cooling can cause the shrinkage clamping force between the casting and the mold core to exceed 20 MPa, increasing demolding resistance and causing scratches on the product surface.

[0104] The status monitoring unit utilizes an ultrasonic flow meter and pressure sensor integrated into the return water collector to perform closed-loop assessment of the operational health of the conformal cooling channels. Due to the use of laser selective melting additive manufacturing technology, the conformal channels typically have an internal aperture of only 8 mm and a complex spatial bending structure. During long-term production, scale buildup or 3D printing residue powder agglomeration can lead to increased local resistance in the channels. The status monitoring unit compares the correlation curve between the inlet and outlet pressure difference ΔP and the real-time flow rate Q. If the monitoring data shows that ΔP increases from 4 bar to 5.5 bar, while Q decreases from 15 liters per minute to 8 liters per minute, the system automatically determines that a physical blockage has occurred in that section of the water path. At this time, the main control unit will output the specific channel number on the human-machine interface and recommend that the operator perform descaling maintenance. This monitoring method avoids batch product scrap due to localized cooling failure causing shrinkage. Compared to existing main channel pressure monitoring, zone monitoring achieves sub-meter level precision diagnosis of the conformal internal cavity status, ensuring the traceability of production data.

[0105] When implementing this closed-loop temperature control system, those skilled in the art need to interface the signal interface of the main control unit with the host control system of the die-casting machine via the Profinet bus to achieve synchronous triggering of the mold closing signal and the preheating logic unit. All temperature signals undergo multi-stage Butterworth filtering within the main control unit to eliminate high-frequency electromagnetic interference generated during the injection of the die-casting machine. When setting the cooling valve logic, a 3-second hysteresis compensation must be reserved to offset the physical delivery delay of the heat exchange medium in the hoses and cable chains. Data from the deep temperature sensing points of the mold frame are also used to adjust the automatic spraying parameters of the release agent. When the substrate temperature exceeds 200 degrees Celsius, the system will automatically link the spraying robot to extend the spraying time and increase the aerosol cooling intensity. This closed-loop process, from point to surface and from hardware perception to software decision-making, enables the entire temperature control system to autonomously maintain stable thermal balance performance of the aluminum-magnesium alloy die-casting mold throughout its entire lifespan of over 30,000 mold cycles without interference from human experience, significantly improving the mechanical properties and dimensional consistency of key automotive structural components.

[0106] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0107] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A temperature control device for die casting of automotive aluminum-magnesium alloy parts, applied to a die casting mold including a fixed mold and a moving mold, wherein the fixed mold and the moving mold form a cavity inside after being closed, characterized in that, The temperature control device includes: The layered temperature measurement module includes multiple temperature sensors disposed inside the die-casting mold, the multiple temperature sensors being distributed in the surface layer near the cavity, the subsurface layer near the gating, and the deep layer of the mold base. A zoned heating module is disposed inside the fixed mold base and arranged circumferentially around the gating system; A partitioned conformal cooling module includes conformal cooling channels disposed inside the fixed mold and the moving mold and distributed in accordance with the contour trajectory of the cavity; and The main control unit has its signal input terminal electrically connected to the layered temperature measurement module, and its control output terminal connected to the zoned heating module and the zoned conformal cooling module, respectively.

2. The temperature control device for die-casting automotive aluminum-magnesium alloy parts according to claim 1, characterized in that, The layered temperature measurement module includes temperature sensing points on the surface of the cavity, temperature sensing points on the subsurface of the sprue, and temperature sensing points deep within the mold frame.

3. The temperature control device for die-casting automotive aluminum-magnesium alloy parts according to claim 2, characterized in that, The temperature sensing point on the surface of the cavity is achieved through an intelligent hollow ejector pin structure. The intelligent hollow ejector pin includes a hollow ejector pin body that moves through the moving mold base. A miniature thermocouple is inserted inside the hollow ejector pin body. The temperature sensing end of the miniature thermocouple is flush with the end face of the hollow ejector pin body that contacts the alloy liquid in the cavity.

4. The temperature control device for die-casting automotive aluminum-magnesium alloy parts according to claim 2, characterized in that, A safety anti-erosion metal wall of preset thickness is provided between the bottom of the sensor mounting hole corresponding to the temperature sensing point on the subsurface of the sprue and the inner wall of the sprue. The mounting hole is filled with a high-temperature resistant thermally conductive medium, which wraps around the temperature sensing end of the sensor.

5. The temperature control device for die-casting automotive aluminum-magnesium alloy parts according to claim 2, characterized in that, The sensor tail corresponding to the deep temperature sensing point of the mold frame is provided with an elastic pre-tightening mechanism, which presses the temperature sensing head of the sensor tightly against the bottom of the blind hole in the mold frame base.

6. The temperature control device for die casting of automotive aluminum-magnesium alloy parts according to claim 1, characterized in that, The partitioned conformal cooling module also includes a water supply distributor and a water return collector located outside the mold. The inlet of the conformal cooling channel is connected to the water supply distributor, and the outlet of the conformal cooling channel is connected to the water return collector. An electromagnetic proportional regulating valve is provided between the water supply distributor and the main water supply pipe of the external constant temperature machine.

7. The temperature control device for die casting of automotive aluminum-magnesium alloy parts according to claim 6, characterized in that, The branch outlet of the return water collector is equipped with an ultrasonic flow meter and a pressure sensor, and the signal output terminals of the ultrasonic flow meter and the pressure sensor are electrically connected to the main control unit.

8. The temperature control device for die casting of automotive aluminum-magnesium alloy parts according to claim 6, characterized in that, The conformal cooling channel is formed inside the mold insert using laser selective melting additive manufacturing process, and the centerline trajectory of the conformal cooling channel and the normal distance to the cavity surface are constant.

9. The temperature control device for die casting of automotive aluminum-magnesium alloy parts according to claim 6, characterized in that, The pipeline connecting the conformal cooling channel on the moving mold side to the external constant temperature machine is laid inside the flexible drag chain, and the moving end of the flexible drag chain moves back and forth synchronously with the moving mold.

10. A temperature control system for die-casting automotive aluminum-magnesium alloy parts, employing the temperature control device for die-casting automotive aluminum-magnesium alloy parts as described in any one of claims 1 to 9, characterized in that... The temperature control system includes: The preheating logic unit is used to control the zone heating module to compensate for heating of the gating area based on the feedback of the deep temperature sensing point of the mold frame before the injection begins. A cooling control unit is used to dynamically adjust the opening of the electromagnetic proportional regulating valve based on real-time data from temperature sensing points on the cavity surface during the pressure holding and cooling stage; and The status monitoring unit is used to determine the unobstructed status of the conformal cooling channel based on the flow rate and pressure data at the return water collector end.

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