Ultrahigh-temperature precision glass molding device and method based on pulse direct current heating

Abstract

The application provides an ultra-high-temperature precision glass molding device and method based on pulse direct current conductive heating, which comprises: an upper conductive molding assembly and a lower conductive molding assembly arranged oppositely along an axial direction, the molding ends of the two assemblies extending into a vacuum chamber to jointly clamp and shape a glass material; a pulse direct current power source is electrically connected with the upper conductive molding assembly and the lower conductive molding assembly respectively, and is used for applying a pulse current to the glass material through the two conductive molding assemblies, so that the glass material is softened due to the Joule heat generated by the resistance when the current flows through the glass material; an electrical isolation structure is connected with the mounting end of the upper conductive molding assembly and / or the mounting end of the lower conductive molding assembly; a pressure detection unit is connected with the electrical isolation structure; a pressing mechanism is connected with the electrical isolation structure or the pressure detection unit; a temperature detection unit is used for detecting the temperature of the glass material in real time; and the pulse direct current power source is configured to adjust its output parameters according to the temperature detected by the temperature detection unit.

Description

Technical Field

[0001] This application relates to the field of optical glass manufacturing technology, and in particular to an ultra-high temperature precision glass molding device and method based on pulsed DC conductive heating. Background Technology

[0002] Precision optical glass components are widely used in high-end imaging systems, laser optics, optical communications, automotive sensing, and consumer electronics. With the miniaturization and integration of optical systems, the demand for complex microstructure optical devices such as freeform lenses, aspherical lenses, and microprism arrays is increasing. These components have high precision, high steepness, or three-dimensional asymmetric surfaces, placing extremely high demands on the molding process. The principle of molding is to place glass material between high-precision molds, apply pressure after heating to a softened state, and make it replicate the mold surface. After cooling, the desired optical surface is obtained. The key to this process is the controlled heating of the glass material to achieve a suitable rheological state for shaping without crystallization or thermal damage.

[0003] In existing technologies, heating elements (such as resistance wires, infrared lamps, etc.) are arranged inside a vacuum chamber, and the mold is indirectly heated through thermal radiation and / or thermal conduction. The mold then transfers the heat to the glass material, softening it. However, for special optical glasses with a transition temperature exceeding 800°C, especially high-refractive-index glasses, glasses containing rare earth elements, or other special components with high glass transition temperatures, this indirect heating method reveals significant limitations: On the one hand, heat must be conducted to the glass through the mold, resulting in a slow heating rate and high thermal inertia. This not only leads to high energy consumption and long process cycles, but the slow heating rate also prolongs the residence time of the glass in the crystallization-sensitive temperature range, making it prone to crystallization, oxidation, or component volatilization, which seriously affects optical performance and surface quality. On the other hand, the large heat capacity of the cavity and mold leads to uneven temperature distribution, making it difficult to meet the high-precision forming requirements of complex microstructures.

[0004] Therefore, the technical problem of how to achieve rapid, uniform, and energy-efficient heating and softening of glass materials under ultra-high temperature conditions still needs to be further solved. Summary of the Invention

[0005] The purpose of this application is to provide an ultra-high temperature precision glass molding device and method based on pulsed DC conductive heating, so as to achieve rapid, uniform and energy-saving heating and softening of glass materials under ultra-high temperature conditions, and ensure the optical performance and surface quality of optical glass components.

[0006] To address the aforementioned technical problems, this application provides the following technical solutions: The first aspect of this application provides an ultra-high temperature precision glass molding device based on pulsed DC conductive heating, comprising: Vacuum chamber; An upper conductive molding assembly and a lower conductive molding assembly are arranged opposite each other along the axial direction, with their molding ends extending into the vacuum chamber to jointly clamp and mold the glass material; A pulsed DC power supply is electrically connected to the upper conductive molding assembly and the lower conductive molding assembly, respectively, and is used to apply a pulsed current to the glass material through the two conductive molding assemblies, so that the glass material softens due to Joule heating generated by resistance when the current flows through it. An electrical isolation structure is connected to the mounting end of the upper conductive molding assembly and / or the mounting end of the lower conductive molding assembly; A pressure detection unit, connected to the electrical isolation structure, is used to detect molding pressure. The electrical isolation structure can block the flow of pulse current into the pressure detection unit. A pressure-applying mechanism, connected to the electrical isolation structure or the pressure detection unit, is used to drive the corresponding conductive molding assembly to move axially in order to apply molding pressure to the softened glass material; A temperature detection unit is used to detect the temperature of the glass material in real time. The pulsed DC power supply is configured to adjust its output parameters according to the temperature detected by the temperature detection unit.

[0007] In some modified embodiments of the first aspect of this application, both the upper conductive molding assembly and the lower conductive molding assembly include: The tube body has a closed end and an open end; A graphite indenter is fixed to and electrically contacted with the closed end, and the graphite indenter has the molding end; The conductive flange is electrically connected to the open end and the pulsed DC power supply, respectively.

[0008] In some modified embodiments of the first aspect of this application, both the upper conductive molding assembly and the lower conductive molding assembly further include: Cooling pipes are inserted into the tube body; A heat-conducting plate is disposed between the outer wall of the cooling pipe and the inner wall of the pipe body.

[0009] Some modified embodiments of the first aspect of this application also include: A flexible electrical connector, one end of which is electrically connected to the pulsed DC power supply; Two rigid conductive busbars are provided, one of which is electrically connected at both ends to the conductive flange of the lower conductive molding assembly and the other end of the flexible electrical connector, respectively. The other rigid conductive busbar is electrically connected at both ends to the pulsed DC power supply and the conductive flange of the upper conductive molding assembly, respectively. The pressure application mechanism is used to drive the lower conductive molding assembly to move.

[0010] In some modified embodiments of the first aspect of this application, the outer diameter of the conductive flange is larger than the outer diameter of the pipe body, and the first end face of the conductive flange facing away from the graphite pressure head is connected to the rigid conductive busbar. The electrical isolation structure includes: An insulating ring is fitted around the outer periphery of the tube and abuts against the second end face of the conductive flange that is opposite to the first end face. The mounting ring is fitted around the outer periphery of the pipe body and abuts against the side of the insulating ring away from the conductive flange. A barrier ring is fitted onto the portion of the tube body located outside the vacuum chamber, and is positioned axially between the graphite indenter and the mounting ring. An insulating pad abuts against the side of the rigid conductive bar that is away from the conductive flange; The mounting pad abuts against the side of the insulating pad opposite to the rigid conductive bar, and the pressure detection unit is connected to the side of the mounting pad opposite to the insulating pad.

[0011] In some modified embodiments of the first aspect of this application, the side wall of the vacuum chamber is provided with an observation window; The temperature detection unit includes: Side plate, connected to the outer wall of the vacuum chamber; A laser thermometer is connected to the side plate, with the detection end of the laser thermometer facing the observation window.

[0012] Some modified embodiments of the first aspect of this application also include: A vacuum connection flange is connected to the side wall of the vacuum chamber. The vacuum connection flange has a vacuum pump port and a pressure detection port. The vacuum pump port is used to communicate with a vacuum pump to evacuate the vacuum chamber, and the pressure detection port is used to communicate with a pressure transmitter to monitor the pressure inside the vacuum chamber. The vacuum chamber is provided with a nitrogen inlet, which is used to connect to a nitrogen generation system. A water-cooling channel is provided inside the side wall of the vacuum chamber, and the water-cooling channel is used to communicate with the water chiller.

[0013] A second aspect of this application provides a method for ultra-high temperature precision glass molding based on pulsed DC conductive heating, comprising: The glass material is placed inside the vacuum chamber and clamped between the upper conductive molding assembly and the lower conductive molding assembly; A pulsed DC current is applied to the upper conductive molding assembly and the lower conductive molding assembly, so that the current flows through the glass material to form a conductive circuit. Joule heating is generated by the resistance of the glass material itself to heat it to the softening temperature. During the heating process, the temperature of the glass material is monitored in real time, and the output parameters of the pulsed DC current are adjusted according to the detected temperature. Molding pressure is applied to the glass material in a softened state, and the molding pressure is detected by a pressure detection unit; wherein the pressure detection unit is isolated from the upper conductive molding assembly and / or the lower conductive molding assembly by an electrical isolation structure to block the inflow of pulsed DC current.

[0014] Some modified embodiments of the second aspect of this application include: During the molding process, the temperature, molding displacement, and molding pressure of the glass material are simultaneously monitored. The output parameters of the pulsed DC current are dynamically adjusted based on the detected temperature of the glass material, the molding displacement, and the molding pressure.

[0015] In some modified embodiments of the second aspect of this application, the dynamic adjustment includes: When the temperature of the glass material is detected to be within the preset softening temperature range, the first rate of change of the molding displacement with respect to time and the second rate of change of the molding pressure with respect to time are calculated in real time. If the first rate of change exceeds the first threshold and the second rate of change is lower than the second threshold, the output parameter of the pulsed DC current is reduced. If the second rate of change exceeds the third threshold and the first rate of change is lower than the fourth threshold, the output parameters of the pulsed DC current are increased.

[0016] Compared to existing technologies, the ultra-high temperature precision glass molding device based on pulsed DC conductive heating provided in the first aspect of this application connects the pulsed DC power supply to the upper and lower conductive molding components respectively, allowing the pulsed current to flow directly through the glass material itself. Since special optical glass possesses a certain degree of conductivity at high temperatures, when current flows through, electrical energy is directly converted into Joule heat within the glass, achieving volumetric heating from the inside out. Because Joule heat is generated relatively uniformly within the glass, the temperature field distribution during softening is highly consistent, effectively avoiding defects such as crystallization, thermal decomposition, or component volatilization caused by localized overheating, thereby ensuring the optical performance and surface quality of the optical glass components. The uniform rheological state ensures synchronous deformation of all areas of the glass during molding, which is beneficial for improving the replication accuracy and surface integrity of complex microstructures such as free-form surfaces and microprism arrays. Since the heat source is located inside the glass material, the thermal inertia and heat transfer delay in traditional indirect heating are fundamentally eliminated, significantly improving the heating rate; simultaneously, the pulsed current can be started and stopped instantaneously, resulting in a rapid heating response and facilitating millisecond-level dynamic control. In addition, electrical energy acts directly on the glass material, significantly reducing energy loss and improving thermal efficiency.

[0017] An electrical isolation structure is installed between the mounting end of the conductive molding assembly and the pressure detection unit, effectively blocking the flow of pulse currents in the thousands of amperes into the pressure detection unit. As a result, the pressure detection unit is unaffected by strong electrical interference and can accurately feed back the molding pressure signal, which helps ensure the reliability and long-term operational stability of the pressure application mechanism, providing fundamental support for high-precision pressure control.

[0018] The actual temperature of the glass material is monitored in real time by a temperature detection unit, and the signal is fed back to the pulsed DC power supply. The power supply dynamically adjusts its output parameters (such as amplitude, pulse width, frequency and / or duty cycle) accordingly, so that the glass strictly follows the preset temperature curve to achieve precise thermal management under ultra-high temperature (≥800℃) conditions.

[0019] In summary, the device of this invention, through the synergistic design of glass self-heating, rapid pulse current regulation, temperature closed-loop feedback, and electrical safety isolation, successfully addresses multiple requirements such as rapid heating, uniform temperature, energy efficiency, precise temperature control, and high-precision force control in the molding of special optical glass with ultra-high glass transition temperature. This provides a reliable technical path for the efficient and high-quality manufacturing of high-performance optical components.

[0020] The ultra-high temperature precision glass molding method based on pulsed DC conductive heating provided in the second aspect of this application has similar technical effects to the ultra-high temperature precision glass molding device based on pulsed DC conductive heating in the first aspect. Attached Figure Description

[0021] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of this application are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein: Figure 1 A schematic diagram of the vacuum chamber, upper conductive molding assembly, and lower conductive molding assembly of an ultra-high temperature precision glass molding device based on pulsed DC conductive heating is shown. Figure 2 The schematic diagram shows the upper conductive molding assembly and the lower conductive molding assembly of an ultra-high temperature precision glass molding device based on pulsed DC conductive heating; Figure 3 A schematic diagram of the frame structure of an ultra-high temperature precision glass molding device based on pulsed DC conductive heating is shown. Figure 4 A schematic diagram of the cooling pipe and heat-conducting plate of an ultra-high temperature precision glass molding device based on pulsed DC conductive heating is shown. Figure 5The schematic diagram shows the structure of the vacuum chamber, vacuum pump, nitrogen generation system, and water chiller of the ultra-high temperature precision glass molding device based on pulsed DC conductive heating.

[0022] Explanation of icon numbers: 1. Vacuum chamber; 2. Upper conductive molding assembly; 21. Tube body; 22. Graphite indenter; 23. Conductive flange; 24. Cooling pipe; 25. Heat-conducting plate; 26. Expansion ring; 3. Lower conductive molding assembly; 4. Pulse DC power supply; 5. Electrical isolation structure; 51. Insulating ring; 52. Mounting ring; 53. Barrier ring; 54. Insulating pad; 55. Mounting pad; 6. Pressure detection unit; 7. Pressurizing mechanism; 8. Temperature detection unit; 81. Side plate; 82. Laser thermometer; 9. Flexible electrical connector; 10. Rigid conductive busbar; 11. Vacuum connection flange; 12. Pressure transmitter; 13. Vacuum pump; 14. Nitrogen generation system; 15. Water chiller; 16. Frame; 161. Housing; 1611. Frame; 1612. Protective plate; 162. First mounting plate; 163. Second mounting plate; 164. Third mounting plate; 17. Controller; 18. Mounting flange; 19. CNC panel. Detailed Implementation

[0023] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0024] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains.

[0025] like Figures 1 to 3 , Figure 5 As shown, the first aspect of this application provides an ultra-high temperature precision glass molding device based on pulsed DC conductive heating, comprising: Vacuum chamber 1; The upper conductive molding assembly 2 and the lower conductive molding assembly 3 are arranged opposite each other along the axial direction, and their molding ends extend into the vacuum chamber 1 to jointly clamp and mold the glass material. The pulsed DC power supply 4 is electrically connected to the upper conductive molding assembly 2 and the lower conductive molding assembly 3 respectively, and is used to apply pulsed current to the glass material through the two conductive molding assemblies so that the glass material softens due to Joule heating generated by resistance when the current flows through it. Electrical isolation structure 5 is connected to the mounting end of the upper conductive molding assembly 2 and / or the mounting end of the lower conductive molding assembly 3; The pressure detection unit 6 is connected to the electrical isolation structure 5 and is used to detect the molding pressure. The electrical isolation structure 5 can block the pulse current from flowing into the pressure detection unit 6. The pressure application mechanism 7 is connected to the electrical isolation structure 5 or the pressure detection unit 6 and is used to drive the corresponding conductive molding assembly to move axially to apply molding pressure to the softened glass material. Temperature detection unit 8 is used to detect the temperature of the glass material in real time; The pulsed DC power supply 4 is configured to adjust its output parameters according to the temperature detected by the temperature detection unit 8.

[0026] Specifically, vacuum chamber 1 is used to provide a sealed, ultra-high temperature working environment for the glass molding process.

[0027] The upper conductive molding assembly 2 and the lower conductive molding assembly 3 combine the functions of conducting electricity, applying pressure, and molding. Their structures can be identical and arranged symmetrically to ensure uniform stress and a symmetrical temperature field.

[0028] The upper conductive molding assembly 2 and the lower conductive molding assembly 3 can be made of materials with high conductivity, high temperature resistance, and stable chemical properties, such as graphite, molybdenum, tungsten, or their composite materials. During the heating process, the pulsed DC power supply 4 introduces current into the glass material sandwiched between the upper conductive molding assembly 2 and the lower conductive molding assembly 3, allowing the current to flow through the glass itself and generating Joule heating through its resistance, thus achieving rapid and uniform bulk heating of the glass material (i.e., heat is generated throughout the glass material).

[0029] The molding end of the upper conductive molding component 2 is in direct contact with the molding end of the lower conductive molding component 3 and clamps the glass material. When the glass material is heated to a softened state, the pressure applying mechanism 7 drives at least one conductive molding component to move axially and apply controllable molding pressure, so that the softened glass material fits the surface of the molding end and accurately replicates its micron- or nano-scale morphology, thereby completing the molding of high-precision optical components (such as aspherical lenses and microlens arrays).

[0030] The pulsed DC power supply 4 provides a controllable pulsed DC current to the upper conductive molding assembly 2 and the lower conductive molding assembly 3 to achieve Joule heating of the glass material. The positive terminal of the pulsed DC power supply 4 is electrically connected to the upper conductive molding assembly 2, and the negative terminal of the pulsed DC power supply 4 is electrically connected to the lower conductive molding assembly 3, or vice versa, so as to form a conductive path together with the glass material during the molding process.

[0031] The pulsed DC power supply 4 is configured with adjustable output parameters. In some embodiments, the output parameters include output amplitude (peak setpoint of current or voltage), pulse width, frequency, and / or duty cycle. The pulsed DC power supply 4 may employ a high-precision digital control module with an output current control resolution of 1 A and an output voltage control resolution of 0.01 V, thereby enabling fine-tuning of the heating power and ensuring the stability and repeatability of the heating process.

[0032] The electrical isolation structure 5 is used to electrically isolate the conductive molding assembly from the pressure detection unit 6, ensuring that the pressure detection unit 6 is not subject to strong electrical interference when a pulsed DC current flows through the conductive molding assembly, thus achieving safe and reliable molding pressure monitoring.

[0033] Both conductive molding components have mounting ends and molding ends along the axial direction. There can be one electrical isolation structure 5, which can be located at the mounting end of the upper conductive molding component 2, or at the mounting end of the lower conductive molding component 3. Alternatively, there can be two electrical isolation structures 5, which can be respectively located at the mounting ends of the upper conductive molding component 2 and the lower conductive molding component 3; preferably, there are two electrical isolation structures 5.

[0034] The electrical isolation structure 5 can be made of non-metallic materials with high insulation strength, high temperature resistance and high mechanical strength, such as alumina ceramic, boron nitride, polyether ether ketone or glass fiber reinforced epoxy resin.

[0035] The pressure detection unit 6 is used to monitor the axial pressure applied to the glass material in real time during the molding process, so as to realize pressure monitoring and safety protection during the molding process and ensure the reliability of equipment operation.

[0036] The pressure detection unit 6 includes at least one pressure sensor. The number of pressure sensors can be one or two, but preferably two pressure detection units 6. Each of the two pressure detection units 6 is connected to an electrical isolation structure 5. The pressure sensors are located from the conductive molding assembly to the frame. The axial force transmission path of 16 is used to directly sense the molding load. The pressure sensor can be a strain gauge pressure sensor, piezoelectric force sensor, piezoresistive sensor, or capacitive pressure sensor, etc.

[0037] The pressure applying mechanism 7 is used to drive the conductive molding assembly to move precisely along the axial direction, thereby applying controllable molding pressure after the glass material softens, and completing the precision molding. The pressure applying mechanism 7 can be a high-precision linear motor or a servo press, with a servo press being preferred. Its axial feed force control accuracy is better than ±0.1 N, its position positioning accuracy reaches ±0.1 μm, and its maximum output load range is 0 to 10 kN (approximately equivalent to 0-1 ton force), to meet the precise control requirements of optical glass for minute pressure and nanometer-level displacement in the softened state.

[0038] In some embodiments, the pressure applying mechanism 7 is a single entity, the output of which is connected to either the upper conductive molding assembly 2 or the lower conductive molding assembly 3 via the pressure detection unit 6 and the electrical isolation structure 5, to drive the conductive molding assembly to move axially (i.e., corresponding to the upper conductive molding assembly 2), while the other conductive molding assembly remains fixed. For example, the pressure applying mechanism 7 is sequentially connected to the pressure sensor, the electrical isolation structure 5, and the upper conductive molding assembly 2 to push the upper mold downward (i.e., corresponding to the lower conductive molding assembly 3); or, the pressure applying mechanism 7 is sequentially connected to the pressure sensor, the electrical isolation structure 5, and the lower conductive molding assembly 3 to push the lower mold upward.

[0039] In some embodiments, there may be two pressure-applying mechanisms 7, which are respectively connected to the upper conductive molding component 2 and the lower conductive molding component 3 to achieve bidirectional synchronous or independent driving, thereby improving the centering accuracy and pressure uniformity.

[0040] Preferably, a single pressure-applying mechanism 7 is used to simplify the system structure, reduce control complexity, and decrease costs.

[0041] The temperature detection unit 8 is used to detect the surface temperature of the glass material in real time during the molding process. The temperature detection unit 8 can be embedded in the side of the upper conductive molding assembly 2 and / or the side of the lower conductive molding assembly 3, avoiding direct contact with the molding end surface of the glass to ensure the integrity of the molded surface. The temperature detection unit 8 can be a tungsten-rhenium thermocouple, a platinum-rhodium thermocouple, or a fiber optic temperature sensor, etc.

[0042] In some embodiments, the device further includes an electrical control box, which houses a controller 17. The controller 17 is signal-connected to the control module of the pulsed DC power supply 4 and the temperature detection unit 8, and is configured to receive the glass material temperature signal from the temperature detection unit 8, and dynamically adjust the output parameters of the pulsed DC power supply 4 based on the real-time feedback.

[0043] In some embodiments, the device further includes a frame 16 and a laser displacement meter, both of which are mounted on the frame 16. The laser displacement meter is located outside the vacuum chamber 1, which has an optical window. The detection end of the laser displacement meter is aligned with the motion output end of the pressure application mechanism 7 through the window to acquire the molding displacement signal in a non-contact manner.

[0044] In a further embodiment, the controller 17 is also connected to the pressure detection unit 6 and the laser displacement meter signal, and is configured to simultaneously receive the glass material temperature signal from the temperature detection unit 8, the molding pressure signal from the pressure detection unit 6, and the molding displacement signal from the displacement sensor, and dynamically adjust the output parameters of the pulsed DC power supply 4 and the motion state (such as the pressurization speed or holding pressure) of the pressure applying mechanism 7 according to multi-source real-time feedback, thereby realizing the thermo-mechanical coordinated closed-loop control of the glass heating and softening and precision forming process.

[0045] In some embodiments, the frame 16 includes a frame 1611, a protective plate 1612, a first mounting plate 162, a second mounting plate 163, a third mounting plate 164, and a fourth mounting plate. The housing 161 is generally rectangular or cylindrical, and includes the frame 1611 and the protective plate 1612. The protective plate 1612 is fixedly connected to the outer periphery of the frame 1611, together forming a housing 161 with accommodating space.

[0046] The first mounting plate 162, the second mounting plate 163, the third mounting plate 164, and the fourth mounting plate are all located within the accommodating space and fixed to the frame 1611. The first mounting plate 162 and the second mounting plate 163 are spaced apart in the vertical direction and are both horizontally arranged. The vacuum chamber 1 is mounted on the first mounting plate 162, which has a through hole. The pressure applying mechanism 7 is mounted on the second mounting plate 163, and its motion output end passes through the through hole and connects to the pressure detection unit 6. The third mounting plate 164 is spaced apart from the first mounting plate 162 in the horizontal direction and is used to mount the pulsed DC power supply 4. The fourth mounting plate is spaced apart from the first mounting plate 162 in the horizontal direction and is used to mount the controller 17.

[0047] In some embodiments, a CNC panel 19 is fixedly mounted on the outer wall of the housing 161. The CNC panel 19 is communicatively connected to the controller 17 and is used to display real-time process parameters during the molding process (such as glass material temperature, molding pressure, displacement, and pulse power supply output status, etc.), and to provide a human-machine interface for operators to set target process curves, start and stop the equipment, or perform manual intervention. The CNC panel 19 may also be equipped with an emergency stop button and status indicator lights to ensure operational safety.

[0048] Compared to existing technologies, the ultra-high temperature precision glass molding device based on pulsed DC conductive heating provided in the first aspect of this application connects the pulsed DC power supply 4 to the upper and lower conductive molding components 3 respectively, allowing the pulsed current to flow directly through the glass material itself. Since special optical glass possesses a certain degree of conductivity at high temperatures, when current flows through, electrical energy is directly converted into Joule heat within the glass, achieving volumetric heating from the inside out. Because Joule heat is generated relatively uniformly within the glass, the temperature field distribution during softening is highly consistent, effectively avoiding defects such as crystallization, thermal decomposition, or component volatilization caused by localized overheating, thereby ensuring the optical performance and surface quality of the optical glass components. The uniform rheological state ensures synchronous deformation of all areas of the glass during molding, which is beneficial for improving the replication accuracy and surface integrity of complex microstructures such as free-form surfaces and microprism arrays. Since the heat source is located inside the glass material, the thermal inertia and heat transfer delay in traditional indirect heating are fundamentally eliminated, significantly improving the heating rate; simultaneously, the pulsed current can be started and stopped instantaneously, resulting in a rapid heating response and facilitating millisecond-level dynamic control. In addition, electrical energy acts directly on the glass material, significantly reducing energy loss and improving thermal efficiency.

[0049] An electrical isolation structure 5 is installed between the mounting end of the conductive molding assembly and the pressure detection unit 6, which can effectively block the flow of pulse currents of thousands of amperes into the pressure detection unit 6. As a result, the pressure detection unit 6 is not affected by strong electrical interference and can accurately feed back the molding pressure signal, which helps to ensure the reliability and long-term operational stability of the pressure application mechanism 7 and provides a basic support for high-precision pressure control.

[0050] The actual temperature of the glass material is monitored in real time by the temperature detection unit 8, and the signal is fed back to the pulse DC power supply 4. The power supply dynamically adjusts its output parameters (such as amplitude, pulse width, frequency and / or duty cycle) accordingly, so that the glass strictly follows the preset temperature curve to achieve precise thermal management under ultra-high temperature (≥800℃) conditions.

[0051] In summary, the device of this invention, through the synergistic design of glass self-heating, rapid pulse current regulation, temperature closed-loop feedback, and electrical safety isolation, successfully addresses multiple requirements such as rapid heating, uniform temperature, energy efficiency, precise temperature control, and high-precision force control in the molding of special optical glass with ultra-high glass transition temperature. This provides a reliable technical path for the efficient and high-quality manufacturing of high-performance optical components.

[0052] like Figure 1 and Figure 2 As shown, in some embodiments, both the upper conductive molding assembly 2 and the lower conductive molding assembly 3 include: The tube body 21 has a closed end and an open end; A graphite pressing head 22 is fixed to and electrically contacts the closed end, and the graphite pressing head 22 has the molding end; The conductive flange 23 is electrically connected to the open end and the pulsed DC power supply 4, respectively.

[0053] Specifically, in some embodiments, both the upper conductive molding assembly 2 and the lower conductive molding assembly 3 include: An expansion ring 26 is fitted around the outer periphery of the closed end and the graphite pressure head 22 to ensure close contact between the graphite pressure head 22 and the closed end, maintaining good electrical contact and mechanical fit.

[0054] The graphite indenter 22 is located inside the vacuum chamber 1. A blind hole is formed on the side wall of the graphite indenter 22, and the temperature detection unit 8 is embedded in this blind hole and fixed by a high-temperature resistant insulating filler. The lead wire of the temperature detection unit 8 passes through a ceramic insulating sleeve and is led out to an external signal acquisition module via an insulating channel inside the tube body 21.

[0055] The tube body 21 is a through-type conductive rod, with its open end extending to the outside of the vacuum chamber 1. It is connected to the conductive flange 23 by bolts, and the mating surface is fitted with a high-temperature resistant conductive sealing ring to achieve dual protection of airtightness and electrical continuity. The conductive flange 23 and the tube body 21 are made of the same or compatible high-conductivity metal material (such as oxygen-free copper or chromium zirconium copper) to reduce contact resistance and improve thermal matching.

[0056] The conductive flange 23 can achieve both airtightness and electrical continuity through bolt fastening. The conductive flange 23 and the pipe body 21 can be made of the same conductive material.

[0057] To effectively control the temperature rise of the conductive molding assembly during pulse heating and molding processes, such as Figure 1 , Figure 2 and Figure 4 As shown, in some embodiments, both the upper conductive molding assembly 2 and the lower conductive molding assembly 3 further include: Cooling pipe 24 is inserted into the pipe body 21; A heat-conducting plate 25 is disposed between the outer wall of the cooling pipe 24 and the inner wall of the pipe body 21.

[0058] Specifically, the cooling pipe 24 is used to connect to an external cooling circulation system. The heat-conducting plate 25 can be connected to the outer wall of the cooling pipe 24 and / or the inner wall of the pipe body 21. The heat-conducting plate 25 can be in a ring-shaped or spiral-shaped structure. Both the heat-conducting plate 25 and the cooling pipe 24 can be made of highly thermally conductive materials (such as oxygen-free copper, aluminum, or graphene composite materials). In some embodiments, the heat-conducting plate 25 is connected to the outer wall of the cooling pipe 24, and the heat-conducting plate 25 forms surface contact with the inner wall of the pipe body 21, thereby efficiently conducting the heat transferred laterally from the graphite pressure head 22 of the pipe body 21 to the cooling pipe 24, where it is then carried away by the flowing cooling medium.

[0059] This cooling structure can quickly reduce the temperature of the conductive molding components after molding, shortening the process cycle; at the same time, it can maintain the area of ​​tube 21 and conductive flange 23 at a safe operating temperature during long-term operation, ensuring the reliability and safety of the equipment in long-term operation.

[0060] To accommodate the axial displacement generated by the pressure applying mechanism 7 driving the conductive molding assembly 3, when the pressure applying mechanism 7 drives the conductive molding assembly 3 to move axially, as follows: Figure 1 and Figure 2 As shown, in some embodiments, it also includes: The flexible electrical connector 9 has one end electrically connected to the pulsed DC power supply 4; Two rigid conductive busbars 10 are provided. One of the rigid conductive busbars 10 has its two ends electrically connected to the conductive flange 23 of the lower conductive molding assembly 3 and the other end of the flexible electrical connector 9, respectively. The other rigid conductive busbar 10 has its two ends electrically connected to the pulsed DC power supply 4 and the conductive flange 23 of the upper conductive molding assembly 2, respectively. The pressure applying mechanism 7 is used to drive the lower conductive molding assembly 3 to move. That is, by placing the flexible electrical connector 9 in the power supply path on the moving side (lower conductive molding assembly 3), the main current path remains continuous and reliable when the lower conductive molding assembly 3 moves axially under the drive of the pressure applying mechanism 7; while the fixed side (upper conductive molding assembly 2) uses a fully rigid connection to ensure low impedance and stability of the current path.

[0061] Specifically, the flexible electrical connector 9 is a flexible conductor with high conductivity that allows axial expansion or contraction, such as a serpentine copper strip or a braided copper braid.

[0062] It should be understood that when the pressure applying mechanism 7 drives the upper conductive molding assembly 2 to move, the flexible electrical connector 9 is correspondingly arranged in the power supply path of the upper conductive molding assembly 2; when the double pressure applying mechanism 7 drives the upper and lower conductive molding assemblies 3 to move synchronously towards each other, the flexible electrical connector 9 can be arranged in both power supply paths, and the remaining structures can be symmetrically arranged with reference to the above-described single-sided movement embodiment.

[0063] To achieve reliable electrical isolation between high-voltage / high-current molded components and external mechanical structures, while ensuring the continuity of the axial force transmission path, such as Figure 1 and Figure 2 As shown, in some embodiments, the outer diameter of the conductive flange 23 is larger than the outer diameter of the tube body 21, and the first end face of the conductive flange 23 facing away from the graphite pressure head 22 is electrically connected to the rigid conductive busbar 10. The electrical isolation structure 5 includes: An insulating ring 51 is fitted around the outer periphery of the tube body 21 and abuts against the second end face of the conductive flange 23 that is opposite to the first end face; it is used for electrical isolation. The mounting ring 52 is fitted around the outer periphery of the tube body 21 and abuts against the side of the insulating ring 51 opposite to the conductive flange 23; it is used to provide a mechanical support reference. The barrier ring 53 is sleeved on the part of the tube body 21 located outside the vacuum chamber 1, and is located axially between the graphite pressure head 22 and the mounting ring 52; it is used to enhance thermal shielding and assist in vacuum sealing.

[0064] An insulating pad 54 abuts against the side of the rigid conductive bar 10 opposite to the conductive flange 23; it is used for electrical isolation.

[0065] Mounting pad 55 abuts against the side of insulating pad 54 opposite to the rigid conductive bar 10, and pressure detection unit 6 is connected to the side of mounting pad 55 opposite to the insulating pad 54. This provides a mechanical support reference.

[0066] Specifically, there are two electrical isolation structures 5, which are respectively disposed on the upper conductive molding assembly 2 and the lower conductive molding assembly 3, so as to realize that the upper and lower molds are respectively isolated from the external frame. Electrical isolation between 16.

[0067] Taking the conductive molding assembly 2 as an example, along the axial direction of its tube body 21 (from the graphite pressure head 22 outwards), the arrangement of each component is as follows: barrier ring 53, mounting ring 52, insulating ring 51, conductive flange 23, rigid conductive busbar 10, insulating pad 54, mounting pad 55, and pressure detection unit 6.

[0068] The main current flows through the graphite indenter 22 and the tube body 21 to the conductive flange 23. The outer diameter of the conductive flange 23 is larger than that of the tube body 21, forming a radial flange. Its second end face is in contact with the insulating ring 51 to achieve high-voltage isolation. The insulating ring 51 and the mounting ring 52 are sleeved on the outer circumference of the tube body 21 and do not participate in the conduction of the main current. The rigid conductive bus 10 is fixed to the first end face of the conductive flange 23 and electrically connected to it, forming part of the main current path (the current flows through the graphite indenter 22, the tube body 21, and the conductive flange 23 to the pulsed DC power supply 4). In the force transmission path, the outer side of the rigid conductive bus 10 is sequentially provided with an insulating pad 54, a mounting pad 55, and a pressure detection unit 6.

[0069] Mounting ring 52, insulating ring 51, insulating pad 54, mounting pad 55, and rigid conductive busbar 10 are all equipped with mounting holes corresponding to the flange holes of conductive flange 23. High-strength insulating bolts or ceramic-coated screws are passed through these mounting holes to pre-tighten and fix these components axially, forming a stable mechanical-electrical integrated unit. This connection method ensures axial stiffness while avoiding direct bridging of high-voltage areas and grounding components with metal bolts, thus maintaining overall insulation performance.

[0070] The insulating ring 51 and insulating pad 54 can be made of high-insulation-strength, high-temperature-resistant ceramic materials (such as alumina, boron nitride) or high-performance engineering plastics (such as polyetheretherketone, polyimide). The mounting ring 52 and mounting pad 55 can be made of high-rigidity metals (such as tool steel or cemented carbide). The mounting ring 52 has a continuous ring structure or consists of a pair of arc-shaped clamping pads, which facilitates assembly and maintenance.

[0071] The combined structure consisting of the upper conductive molding component 2 and the electrical isolation structure 5 can be the same as the combined structure consisting of the lower conductive molding component 3 and the electrical isolation structure 5, and the two combined structures are arranged axially symmetrically.

[0072] In some embodiments, the device further includes a mounting flange 18. Taking the pressure applying mechanism 7 driving the lower conductive molding assembly 3 as an example, the mounting flange 18 is fixed to the motion output end of the pressure applying mechanism 7 and connected to one side of the pressure detection unit 6; the other side of the pressure detection unit 6 is connected to the mounting pad 55 of the lower conductive molding assembly 3, thereby forming a complete axial force transmission path.

[0073] Furthermore, in some embodiments, another pressure detection unit 6 may be provided on the side of the mounting pad 55 of the upper conductive molding assembly 2 away from the molding end. This pressure detection unit 6 is rigidly abutted against the fixed support structure (e.g., protective plate 1612 or frame 1611) of the frame 16, and is used to monitor the reaction force on the upper mold in real time, so as to realize synchronous feedback and closed-loop control of the pressure of the upper and lower molds. Figure 3 As shown (only part of the protective plate 1612 is shown in the figure).

[0074] like Figure 1 As shown, in some embodiments, the sidewall of the vacuum chamber 1 is provided with an observation window; Temperature detection unit 8 includes: Side plate 81 is connected to the outer wall of the vacuum chamber 1; A laser thermometer 82 is connected to the side plate 81, with the detection end of the laser thermometer 82 facing the observation window.

[0075] Specifically, the observation window is made of a high-temperature resistant, high-transmittance material (such as quartz glass or sapphire) to enable non-contact temperature measurement within the cavity.

[0076] The laser thermometer 82 emits a laser and receives the thermal radiation signal from the surface of the graphite indenter 22 to obtain the temperature of the glass or graphite in real time during the molding process, thus achieving non-contact, high-response temperature monitoring.

[0077] like Figure 1 and Figure 5 As shown, in some embodiments, it also includes: A vacuum connection flange 11 is connected to the side wall of the vacuum chamber 1. The vacuum connection flange 11 has a vacuum pump port 13 and a pressure detection port. The vacuum pump port 13 is used to communicate with a vacuum pump 13 to evacuate the vacuum chamber 1. The pressure detection port is used to communicate with a pressure transmitter 12 to monitor the pressure inside the vacuum chamber 1. The vacuum chamber 1 is provided with a nitrogen inlet, which is used to connect with the nitrogen generation system 14 and to supply nitrogen into the vacuum chamber to maintain a non-oxidizing atmosphere.

[0078] A water-cooling channel is provided in the side wall of the vacuum chamber 1, and the water-cooling channel is used to communicate with the water chiller 15.

[0079] Specifically, the water-cooling channel can be arranged in a spiral or loop shape, with both ends connected to the outlet and return water ports of the external water chiller 15, respectively, to cool the cavity and prevent heat from being conducted to the frame 16.

[0080] In some embodiments, the device may further integrate a vacuum pump 13, a nitrogen generation system 14, and a water chiller 15 to form a fully functional glass molding system.

[0081] like Figure 1 and Figure 2 As shown, the second aspect of this application provides a method for ultra-high temperature precision glass molding based on pulsed DC conductive heating, comprising: The glass material is placed inside the vacuum chamber 1 and clamped between the upper conductive molding assembly 2 and the lower conductive molding assembly 3; A pulsed DC current is applied to the upper conductive molding component 2 and the lower conductive molding component 3, so that the current flows through the glass material to form a conductive circuit. Joule heating is generated by the resistance of the glass material itself to heat it to the softening temperature. During the heating process, the temperature of the glass material is monitored in real time, and the output parameters of the pulsed DC current are adjusted according to the detected temperature. Molding pressure is applied to the glass material in a softened state, and the molding pressure is detected by the pressure detection unit 6; wherein, the pressure detection unit 6 is isolated from the upper conductive molding assembly 2 and / or the lower conductive molding assembly 3 by an electrical isolation structure 5 to block the inflow of pulsed DC current.

[0082] Specifically, during the heating process, the temperature of the glass material can be acquired in real time through the temperature detection unit 8, and the temperature signal is fed back to the controller 17. The controller 17 dynamically adjusts the output parameters of the pulsed DC power supply 4 according to the preset target temperature curve.

[0083] In some embodiments, the target temperature profile can be set based on the thermophysical properties of the glass material to be molded (such as glass transition temperature, softening point, coefficient of thermal expansion) and / or historical process data or simulation results. This target temperature profile can be input by the operator or automatically retrieved by the system.

[0084] The controller 17 compares the measured temperature at the current moment with the set temperature corresponding to the target temperature curve at that moment, and adjusts the output parameters of the pulse DC power supply 4 according to the following strategy: When the measured temperature is higher than the target temperature, the controller 17 reduces the output parameters of the pulsed DC power supply 4, and may perform at least one of the following operations: Reducing the output amplitude (i.e., decreasing the peak setting of current or voltage) directly reduces single-pulse energy; Shorten the pulse width (i.e., the duration of each pulse) to reduce the energy injection per pulse. Reduce the frequency (i.e., lengthen the pulse interval) to reduce the number of pulses per unit time; Reduce the duty cycle (the ratio of pulse width to pulse period) and comprehensively regulate the average power.

[0085] When the measured temperature is lower than the target temperature, the controller 17 increases the output parameters of the pulsed DC power supply 4, and may perform at least one of the following operations: Increase output amplitude to enhance single-pulse heating intensity; Increase the pulse width and prolong the duration of each power-on cycle; Increase the frequency, thereby increasing the frequency of energy input per unit time; Increase the duty cycle to improve the average heating power.

[0086] When the temperature of the glass material is detected to be within the preset softening temperature range, molding pressure is applied.

[0087] Through this multi-degree-of-freedom closed-loop control strategy, the system can achieve precise control of the Joule heat generation of glass materials within a millisecond response time, effectively ensuring the repeatability of the ultra-high temperature molding process and the forming quality of optical components.

[0088] The ultra-high temperature precision glass molding method based on pulsed DC conductive heating provided in the second aspect of this application has similar technical effects to the ultra-high temperature precision glass molding device based on pulsed DC conductive heating in the first aspect.

[0089] Although the molding process begins after the glass material reaches a preset softening temperature range, the measured temperature may still deviate from the preset softening temperature range during molding due to thermal conduction, material inhomogeneity, and the dynamic characteristics of electrothermal coupling. Therefore, temperature can be continuously monitored during the molding stage, and the pulsed DC current can be dynamically adjusted in conjunction with displacement and pressure responses to maintain the material in a suitable rheological state for forming. In some embodiments, this includes: During the molding process, the temperature, molding displacement, and molding pressure of the glass material are simultaneously monitored. The output parameters of the pulsed DC current are dynamically adjusted based on the detected temperature of the glass material, the molding displacement, and the molding pressure.

[0090] In some embodiments, it also includes: The pressure application mechanism 7 is dynamically adjusted based on the detected temperature of the glass material, the molding displacement, and the molding pressure.

[0091] Specifically, when the molding pressure has reached the set value, but the molding displacement growth stagnates and the measured temperature is lower than the lower limit of the preset softening temperature range, it indicates that the glass is not sufficiently softened. At this time, the controller 17 increases the output parameters of the pulsed DC power supply 4 to supplement Joule heat. At the same time, the pressure applying mechanism 7 can be controlled to pause further pressing or maintain the current pressure to avoid forced compression in an unsoftened state, thereby preventing glass cracking or mold damage. Pressurization is resumed after the temperature rises back to the softening range.

[0092] When the molding displacement increases rapidly, the molding pressure drops sharply, and the measured temperature is significantly higher than the upper limit of the preset softening temperature range, it indicates that the material is over-softened and there is a risk of collapse. At this time, the controller 17 reduces the output parameters of the pulsed DC power supply 4 to suppress overheating. At the same time, the pressure applying mechanism 7 can be controlled to slow down the pressing speed, switch to displacement control mode, or briefly retract to release part of the load, preventing the glass from overflowing the cavity or losing contour accuracy due to excessive fluidity.

[0093] When the measured temperature is within the preset softening temperature range, but the displacement and pressure response are abnormal (such as the molding pressure continuously rising while the molding displacement remains almost unchanged), it may be due to poor contact or uneven resistance distribution between the glass and the graphite indenter 22, resulting in insufficient local heating. In this case, the pulse frequency or pulse width can be appropriately increased to enhance Joule heat input, optimize the current path and heat distribution, promote uniform softening of the material, and thus restore normal molding fluidity. At the same time, the pressure application mechanism 7 is controlled to perform micro-amplitude reciprocating vibration to improve the contact state between the glass and the indenter, promote heat conduction and uniform softening of the material, and continue to apply pressure stably after the displacement-pressure response returns to normal.

[0094] Through the above-mentioned electro-thermal-mechanical multi-domain coordinated control strategy, the system can adaptively balance heating and loading behavior under complex dynamic conditions, significantly improving the forming stability of ultra-high temperature glass molding and the surface quality of optical components.

[0095] In some embodiments, the dynamic adjustment includes: When the temperature of the glass material is detected to be within the preset softening temperature range, the first rate of change of the molding displacement with respect to time and the second rate of change of the molding pressure with respect to time are calculated in real time. If the first rate of change exceeds the first threshold and the second rate of change is lower than the second threshold, the output parameter of the pulsed DC current is reduced. If the second rate of change exceeds the third threshold and the first rate of change is lower than the fourth threshold, the output parameters of the pulsed DC current are increased.

[0096] Specifically, when the temperature of the glass material is detected to be within the preset softening temperature range, the controller 17 calculates in real time the first rate of change of the molding displacement with respect to time and the second rate of change of the molding pressure with respect to time.

[0097] If the first rate of change exceeds a first threshold (e.g., greater than 0.5 mm / s), it indicates that the glass material is flowing rapidly; simultaneously, if the second rate of change is below a second threshold (e.g., the pressure change rate is close to zero or negative), it indicates that the molding load has not been effectively established or is decreasing; this combined characteristic reflects that the material has become excessively soft, posing a risk of collapse or molding instability. At this time, the controller 17 reduces the output parameter of the pulsed DC current to suppress further heating and slow down the material flow.

[0098] Conversely, if the second rate of change exceeds the third threshold (e.g., a rapid increase in pressure with a rate of change greater than 10 N / s), it indicates a sharp increase in molding resistance; simultaneously, if the first rate of change is below the fourth threshold (e.g., less than 0.05 mm / s), it indicates that material deformation has almost stopped; this combined characteristic reflects insufficient local hardening or softening of the glass. In this case, the controller 17 increases the output parameter of the pulsed DC current to enhance the Joule heat input and promote the recovery of material fluidity.

[0099] The first, second, third, and fourth thresholds can be preset based on the glass material type, mold structure, and process experience. Through this dynamic criterion based on the rate of change, the system can identify rheological anomalies within milliseconds and achieve feedforward-feedback coordinated adjustment of heating power, significantly improving the stability and repeatability of the molding process.

[0100] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A high-temperature precision glass molding device based on pulsed DC conductive heating, characterized in that, include: Vacuum chamber; An upper conductive molding assembly and a lower conductive molding assembly are arranged opposite each other along the axial direction, with their molding ends extending into the vacuum chamber to jointly clamp and mold the glass material; A pulsed DC power supply is electrically connected to the upper conductive molding assembly and the lower conductive molding assembly, respectively, and is used to apply a pulsed current to the glass material through the two conductive molding assemblies, so that the glass material softens due to Joule heating generated by resistance when the current flows through it. An electrical isolation structure is connected to the mounting end of the upper conductive molding assembly and / or the mounting end of the lower conductive molding assembly; A pressure detection unit, connected to the electrical isolation structure, is used to detect molding pressure. The electrical isolation structure can block the flow of pulse current into the pressure detection unit. A pressure-applying mechanism, connected to the electrical isolation structure or the pressure detection unit, is used to drive the corresponding conductive molding assembly to move axially in order to apply molding pressure to the softened glass material; A temperature detection unit is used to detect the temperature of the glass material in real time. The pulsed DC power supply is configured to adjust its output parameters according to the temperature detected by the temperature detection unit.

2. The ultra-high temperature precision glass molding device based on pulsed DC conductive heating according to claim 1, characterized in that, Both the upper conductive molding assembly and the lower conductive molding assembly include: The tube body has a closed end and an open end; A graphite indenter is fixed to and electrically contacted with the closed end, and the graphite indenter has the molding end; The conductive flange is electrically connected to the open end and the pulsed DC power supply, respectively.

3. The ultra-high temperature precision glass molding device based on pulsed DC conductive heating according to claim 2, characterized in that, Both the upper conductive molding assembly and the lower conductive molding assembly further include: Cooling pipes are inserted into the tube body; A heat-conducting plate is disposed between the outer wall of the cooling pipe and the inner wall of the pipe body.

4. The ultra-high temperature precision glass molding device based on pulsed DC conductive heating according to claim 2, characterized in that, Also includes: A flexible electrical connector, one end of which is electrically connected to the pulsed DC power supply; Two rigid conductive busbars are provided, one of which is electrically connected at both ends to the conductive flange of the lower conductive molding assembly and the other end of the flexible electrical connector, respectively. The other rigid conductive busbar is electrically connected at both ends to the pulsed DC power supply and the conductive flange of the upper conductive molding assembly, respectively. The pressure application mechanism is used to drive the lower conductive molding assembly to move.

5. The ultra-high temperature precision glass molding device based on pulsed DC conductive heating according to claim 4, characterized in that, The outer diameter of the conductive flange is larger than the outer diameter of the pipe body, and the first end face of the conductive flange away from the graphite indenter is electrically connected to the rigid conductive busbar. The electrical isolation structure includes: An insulating ring is fitted around the outer periphery of the tube and abuts against the second end face of the conductive flange that is opposite to the first end face. The mounting ring is fitted around the outer periphery of the pipe body and abuts against the side of the insulating ring away from the conductive flange. A barrier ring is fitted onto the portion of the tube body located outside the vacuum chamber, and is positioned axially between the graphite indenter and the mounting ring. An insulating pad abuts against the side of the rigid conductive bar that is away from the conductive flange; The mounting pad abuts against the side of the insulating pad opposite to the rigid conductive bar, and the pressure detection unit is connected to the side of the mounting pad opposite to the insulating pad.

6. The ultra-high temperature precision glass molding device based on pulsed DC conductive heating according to claim 1, characterized in that, The side wall of the vacuum chamber is equipped with an observation window; The temperature detection unit includes: Side plate, connected to the outer wall of the vacuum chamber; A laser thermometer is connected to the side plate, with the detection end of the laser thermometer facing the observation window.

7. The ultra-high temperature precision glass molding device based on pulsed DC conductive heating according to claim 1, characterized in that, Also includes: A vacuum connection flange is connected to the side wall of the vacuum chamber. The vacuum connection flange has a vacuum pump port and a pressure detection port. The vacuum pump port is used to communicate with a vacuum pump to evacuate the vacuum chamber, and the pressure detection port is used to communicate with a pressure transmitter to monitor the pressure inside the vacuum chamber. The vacuum chamber is provided with a nitrogen inlet, which is used to connect to a nitrogen generation system. A water-cooling channel is provided inside the side wall of the vacuum chamber, and the water-cooling channel is used to communicate with the water chiller.

8. A method for ultra-high temperature precision glass molding based on pulsed DC conductive heating, characterized in that, include: The glass material is placed inside the vacuum chamber and clamped between the upper conductive molding assembly and the lower conductive molding assembly; A pulsed DC current is applied to the upper conductive molding assembly and the lower conductive molding assembly, so that the current flows through the glass material to form a conductive circuit. Joule heating is generated by the resistance of the glass material itself to heat it to the softening temperature. During the heating process, the temperature of the glass material is monitored in real time, and the output parameters of the pulsed DC current are adjusted according to the detected temperature. Molding pressure is applied to the glass material in a softened state, and the molding pressure is detected by a pressure detection unit; wherein the pressure detection unit is isolated from the upper conductive molding assembly and / or the lower conductive molding assembly by an electrical isolation structure to block the inflow of pulsed DC current.

9. The ultra-high temperature precision glass molding method based on pulsed DC conductive heating according to claim 8, characterized in that, include: During the molding process, the temperature, molding displacement, and molding pressure of the glass material are simultaneously monitored. The output parameters of the pulsed DC current are dynamically adjusted based on the detected temperature of the glass material, the molding displacement, and the molding pressure.

10. The ultra-high temperature precision glass molding method based on pulsed DC conductive heating according to claim 9, characterized in that, The dynamic adjustment includes: When the temperature of the glass material is detected to be within the preset softening temperature range, the first rate of change of the molding displacement with respect to time and the second rate of change of the molding pressure with respect to time are calculated in real time. If the first rate of change exceeds the first threshold and the second rate of change is lower than the second threshold, the output parameter of the pulsed DC current is reduced. If the second rate of change exceeds the third threshold and the first rate of change is lower than the fourth threshold, the output parameters of the pulsed DC current are increased.

Images