Vacuum cup vacuum cavity sealing welding control method and system

Abstract

The application provides a vacuum chamber sealing welding control method and system for a vacuum cup, and relates to the technical field of vacuum cup welding. The method comprises the following steps: obtaining real-time temperature information of monitoring areas on both sides of a molten pool during energy beam sealing welding; determining real-time temperature differences of the first monitoring area and the second monitoring area according to the real-time temperature information; judging whether the real-time temperature differences meet preset asymmetric solidification triggering conditions; and when the asymmetric solidification triggering conditions are met, dynamically adjusting the energy distribution state of the energy beam to increase the energy input by the monitoring area with a lower temperature between the first monitoring area and the second monitoring area. The method aims to solve the problem of uneven heat dissipation of the molten pool during energy beam sealing welding caused by inconsistent material properties around the vacuum cup after cladding repair, thereby causing unstable welding quality and high defect rate, and ensure the symmetric solidification of the molten pool, thereby significantly improving the quality and reliability of sealing welding.

Description

Technical Field

[0001] This invention relates to the field of thermos cup welding technology, and more specifically, to a method and system for controlling the sealing welding of the vacuum cavity of a thermos cup. Background Technology

[0002] In daily life, insulated cups have become indispensable household items, keeping our drinks at the desired temperature for extended periods, whether hot or cold. This excellent insulation is primarily due to the vacuum layer formed between the inner and outer shells of the insulated cup. This vacuum environment acts like an invisible heat insulation barrier, significantly reducing heat transfer through conduction and convection, thus effectively locking in the internal temperature. During the manufacturing process, a small vent is typically left on the outer shell to remove air from the spacer. After achieving the desired vacuum level, this vent must be tightly sealed to create a permanent vacuum insulation cavity. To ensure reliable sealing, the industry commonly uses energy beam welding techniques such as laser welding for the sealing process. This is because such welding technology has concentrated energy, minimal thermal impact on the surrounding materials, and allows for rapid formation of high-quality sealing welds.

[0003] However, during actual production, transportation, warehousing, logistics, and subsequent user use, insulated cups inevitably encounter bumps and pressure, resulting in various minor damages to the outer shell, such as dents, scratches, and even tiny cracks. For insulated cups with high value or special commemorative significance, simply discarding them would result in unnecessary resource waste and increase user costs. Therefore, repair technologies for damaged insulated cups have emerged, among which laser cladding is a widely used advanced surface repair technology. This technology is like patching a damaged cup; a high-power laser beam melts matching alloy powder, which is then deposited layer by layer on the damaged area. After cooling, a new metal layer that bonds firmly to the substrate is formed, thus filling and smoothing the damage and restoring the cup to its original shape and structural integrity.

[0004] However, when this laser cladding repair technology is used in the repair of thermos cups, a rather tricky technical problem arises. The repaired cladding area is not simply a cover over the original substrate surface. This newly added cladding layer differs significantly from the original stainless steel substrate of the thermos cup in terms of material composition, internal metal structure, and forming thickness. For example, to give the repaired area better wear resistance and corrosion resistance, cobalt-based or nickel-based alloy powders are usually chosen as the cladding material. However, the thermal conductivity, melting temperature, and thermal expansion characteristics of these alloys are significantly different from the 304 stainless steel substrate commonly used in thermos cups. As a result, the repaired cladding area becomes a heterogeneous area with inconsistent material properties around the vent.

[0005] The core issue lies in the fact that the vent of a thermos flask is typically located at the edge of the bottom, precisely where everyday bumps and knocks are most likely to cause damage. Therefore, the vent is often very close to the cladding repair area, frequently situated at the boundary between the repaired and undamaged areas. When laser cladding repairs damage near the bottom, this newly formed cladding layer, with its different thickness and material properties compared to the original substrate, sits right next to the vent, which will be sealed during welding. This directly leads to a highly uneven thermal environment around the vent. During the subsequent energy beam sealing welding of the vent, this cladding layer acts as a heterogeneous heat sink with completely different thermophysical properties compared to the surrounding area. Its heat absorption and conduction behavior differs significantly from the unrepaired original area.

[0006] In welding environments with uneven heat distribution, if the standard energy beam welding process, originally designed for homogeneous materials, is still used to seal the vent holes, the final weld quality will become highly unstable and difficult to control. Specifically, when the energy beam acts on the vent hole to form a molten pool, the molten pool closer to the cladding repair area loses heat at different rates due to the different thermophysical properties of the cladding layer. Often, because the cladding layer has stronger thermal conductivity or greater thickness, the heat on that side is carried away rapidly, causing the molten pool on that side to cool much faster than the other side. This asymmetrical cooling rate will result in insufficient weld penetration on the repair area side, and may even cause fine welding cracks inside the weld due to the excessively rapid cooling rate. On the normal material side, farther from the cladding repair area, the slower heat dissipation rate makes it prone to localized overheating, leading to metal evaporation, welding spatter, and in severe cases, even burning through the cup shell, forming collapses or internal pores at the weld point. The final weld joint has an irregular shape, uneven distribution of internal residual stress, and insufficient weld joint density, which greatly reduces the reliability of the seal.

[0007] These welding defects caused by uneven heat dissipation directly result in a very low pass rate for repaired thermos cups. In subsequent vacuum leak testing, such as using a helium mass spectrometer for sealing checks, many repaired thermos cups are found to have minor leaks, making it impossible to maintain the vacuum level inside the interlayer for extended periods. This renders the previous repair work meaningless. To address this issue, industry technicians have attempted to improve the situation by simply adjusting welding parameters, such as increasing the overall energy beam output power to compensate for heat loss on one side of the cladding repair area. However, this adjustment often exacerbates the burn-through problem on the normal area away from the cladding layer. Conversely, reducing the overall energy beam output power to avoid burn-through fails to ensure sufficient melting and penetration of the metal closer to the cladding layer. This trade-off clearly demonstrates that a single, fixed welding parameter setting is fundamentally inadequate to adapt to the localized, uneven, and asymmetrical heat distribution caused by heterogeneous repair areas.

[0008] Therefore, the core challenge in sealing the vent holes at the interface of dissimilar materials is no longer finding and setting an optimal set of fixed welding parameters, but rather enabling the welding process to sense and adapt in real time to the uneven heat distribution around the vent holes caused by the cladding repair. Currently, there is an urgent need for a control scheme that can dynamically adjust the energy output of the energy beam in real time based on the changes in the thermal state of both sides of the molten pool during the welding process. This scheme needs to be able to adjust the energy distribution on both sides of the molten pool to compensate for the differences in heat dissipation caused by different material properties, ensuring that the molten pool can solidify synchronously and symmetrically, ultimately resulting in a reliable and sealed weld joint.

[0009] There is currently no effective technical solution to the above problems. Summary of the Invention

[0010] The purpose of this invention is to provide a method and system for controlling the sealing welding of the vacuum cavity of a thermos cup. This invention aims to solve the problem of uneven heat dissipation of the molten pool during the energy beam sealing welding process caused by inconsistent material properties around the vent after cladding repair of the thermos cup, which leads to unstable welding quality and high defect rate. The invention ensures symmetrical solidification of the molten pool and significantly improves the quality and reliability of the sealing welding.

[0011] In a first aspect, the present invention provides a method for controlling the sealing welding of a vacuum chamber in a thermos cup, used for energy beam sealing welding of the vent hole of a repaired workpiece, wherein the repaired workpiece includes a repair area and a normal area, the repair area and the normal area having different material properties, and the method for controlling the sealing welding of a vacuum chamber in a thermos cup includes the following steps: S1. During the energy beam sealing welding process, real-time temperature information of the monitoring areas on both sides of the molten pool is obtained; the monitoring areas on both sides of the molten pool include a first monitoring area on the side of the molten pool closer to the repair area, and a second monitoring area on the side of the molten pool closer to the normal area; S2. Determine the real-time temperature difference between the first monitoring area and the second monitoring area based on the real-time temperature information; S3. Determine whether the real-time temperature difference meets the preset asymmetric solidification triggering condition; S4. When the asymmetric solidification triggering condition is met, the energy distribution state of the energy beam is dynamically adjusted to increase the energy input to the monitoring area with lower temperature in the first monitoring area and the second monitoring area, thereby compensating for the uneven heat dissipation caused by the different material properties between the repair area and the normal area, and thus ensuring that the molten pool achieves symmetrical solidification.

[0012] The vacuum cavity sealing welding control method for thermos cups provided by this invention can sense the thermal state difference on both sides of the molten pool in real time and dynamically adjust the energy distribution of the energy beam. It effectively compensates for the uneven heat dissipation caused by the different material properties of the repair area and the normal area, thereby ensuring symmetrical solidification of the molten pool, significantly improving the quality and reliability of sealing welding, and solving the defect problem caused by welding of dissimilar materials in the prior art.

[0013] Secondly, the present invention provides a vacuum chamber sealing welding control system for a thermos cup, used for energy beam sealing welding of the vent hole of a repaired workpiece, wherein the repaired workpiece includes a repair area and a normal area, the repair area and the normal area having different material properties, and the vacuum chamber sealing welding control system for the thermos cup includes: The temperature monitoring unit is used to acquire real-time temperature information of the monitoring areas on both sides of the molten pool during the energy beam sealing welding process; the monitoring areas on both sides of the molten pool include a first monitoring area on the side of the molten pool closer to the repair area, and a second monitoring area on the side of the molten pool closer to the normal area. The calculation unit is used to determine the real-time temperature difference between the first monitoring area and the second monitoring area based on the real-time temperature information; A logic unit is used to determine whether the real-time temperature difference meets the preset asymmetric solidification triggering condition; The controller is used to dynamically adjust the energy distribution state of the energy beam when the asymmetric solidification triggering condition is met, so as to increase the energy invested in the monitoring area with lower temperature in the first monitoring area and the second monitoring area, thereby compensating for the uneven heat dissipation caused by the different material properties between the repair area and the normal area, and thus ensuring that the molten pool achieves symmetrical solidification.

[0014] As can be seen from the above, the vacuum cavity sealing welding control method for thermos cups provided by this invention effectively solves the problem in the prior art where uneven heat dissipation of the molten pool during the sealing welding of the evacuation hole is caused by the difference in material properties between the molten repair area and the normal area of ​​the thermos cup, leading to welding defects (such as insufficient melting depth, cracks, burn-through, spatter, porosity, etc.). By sensing and dynamically adjusting the energy distribution in real time, this application can accurately balance the heat input and loss on both sides of the molten pool, avoiding the limitations of traditional fixed-parameter welding processes. Therefore, this application can significantly improve welding quality, ensuring that the weld point shape is regular, the density is high, and the residual stress distribution is uniform, thereby greatly improving the sealing reliability and product qualification rate of the repaired thermos cup, overcoming the dilemma in the prior art where the repair work is rendered meaningless due to welding defects.

[0015] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0016] Figure 1 A flowchart illustrating a method for controlling the sealing welding of a vacuum chamber in a thermos cup, as provided in an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of a vacuum chamber sealing welding control system for a thermos provided in an embodiment of the present invention.

[0018] Label Explanation: 100. Temperature monitoring unit; 200. Calculation unit; 300. Logic unit; 400. Controller. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0021] In traditional vacuum chamber sealing welding processes for thermos cups, the material properties of the repaired and normal areas differ, leading to inconsistent thermal conductivity. This inconsistency manifests as a significant difference in heat dissipation rates across the molten pool during energy beam sealing welding, resulting in asymmetric solidification. Consequently, defects such as incomplete penetration, cracks, and porosity are prone to occur in the welded area, ultimately affecting the sealing integrity of the vacuum chamber and preventing the thermos cup from maintaining the required vacuum state.

[0022] For example, in the process of repairing dents on the bottom of a 304 stainless steel thermos, after laser cladding repair using cobalt-based alloy powder, the thermophysical properties of the repaired area differed significantly from the original stainless steel substrate. During subsequent laser sealing welding of the vent hole located at the edge of the bottom, the cladding repair area was adjacent to the vent, causing the heat loss rate on the side of the molten pool closer to the repair area to be much higher than on the other side. Specifically, during welding, the side of the molten pool closer to the repair area cooled too quickly due to rapid heat loss, resulting in insufficient penetration and microcracks; while the side farther from the repair area overheated due to excessive heat accumulation, causing metal spatter and localized burn-through. Furthermore, this asymmetric solidification led to irregular weld joint shapes and uneven internal stress distribution, making it impossible to meet the sealing requirements during vacuum testing.

[0023] If the above problems are not addressed, welding defects will inevitably lead to the failure of the vacuum chamber seal, preventing the thermos from effectively maintaining a vacuum state and thus losing its heat preservation function. Furthermore, the uncontrollable nature of the welding process will increase the scrap rate in production, extend the manufacturing cycle, and may cause potential safety risks due to seal failure. Therefore, solving this problem is essential to ensuring the reliability and lifespan of the repaired thermos.

[0024] For reference, see the appendix. Figure 1 This invention provides a method for controlling the sealing welding of a vacuum chamber in a thermos cup, used for energy beam sealing welding of the vent hole of a repaired workpiece. The repaired workpiece includes a repair area and a normal area, and the repair area and the normal area have different material properties. The method for controlling the sealing welding of a vacuum chamber in a thermos cup includes the following steps: S1. During the energy beam sealing welding process, a non-contact infrared temperature sensor array symmetrically arranged along the welding direction is used to obtain real-time temperature information of the monitoring areas on both sides of the molten pool; the monitoring areas on both sides of the molten pool include a first monitoring area on the side of the molten pool closer to the repair area and a second monitoring area on the side of the molten pool closer to the normal area. S2. Determine the real-time temperature difference between the first monitoring area and the second monitoring area based on real-time temperature information; S3. Determine whether the real-time temperature difference meets the preset asymmetric solidification triggering condition; S4. When the asymmetric solidification triggering condition is met, the energy distribution state of the energy beam is dynamically adjusted to increase the energy input to the monitoring area with a lower temperature in the first and second monitoring areas, thereby compensating for the uneven heat dissipation caused by the different material properties between the repair area and the normal area, and thus ensuring that the molten pool achieves symmetrical solidification.

[0025] This method aims to solve the problem of uneven heat dissipation caused by the different material properties between the repair area and the normal area when performing energy beam sealing welding on the vent hole of a workpiece that has been clad and repaired. This will help avoid asymmetrical solidification of the molten pool and improve welding quality and sealing reliability.

[0026] For ease of understanding, the following explains some key terms in this embodiment: Repaired workpiece after cladding: refers to a workpiece that has been repaired by laser cladding technology. Its surface has a new area (repair area) formed by cladding material. The material properties of this area are different from those of the original area (normal area) of the workpiece.

[0027] Vacuum hole: A pre-reserved hole between the inner and outer shells of the thermos for vacuuming. It needs to be sealed by welding after vacuuming is completed.

[0028] Energy beam sealing welding: a welding technology that uses a high-energy-density beam (such as a laser beam, electron beam, etc.) to melt and solidify the vent hole, thereby achieving a seal.

[0029] Repaired area: The area on the workpiece that has been repaired by laser cladding technology may have different material composition, microstructure and thickness than the original substrate.

[0030] Normal area: The original substrate area on the workpiece that has been repaired by laser cladding technology but has not been repaired.

[0031] Different material properties: This refers to the differences between the repaired area and the normal area in thermophysical properties such as thermal conductivity, heat capacity, melting point, and coefficient of thermal expansion.

[0032] Molten pool: A liquid metal region formed by the localized melting of workpiece material under the action of an energy beam.

[0033] Non-contact infrared temperature sensor array: A sensor system that measures temperature by receiving infrared energy radiated from the surface of an object. Its characteristics are non-contact measurement and the ability to acquire temperature distribution information within a certain area through an array.

[0034] Monitoring areas on both sides of the molten pool: These refer to two specific areas in the lateral direction of the molten pool, one near the repair area and the other near the normal area, used for real-time monitoring of temperature information.

[0035] Real-time temperature information: refers to the data continuously acquired by the sensor array during the energy beam sealing welding process, reflecting the current temperature status of the monitoring areas on both sides of the molten pool.

[0036] Real-time temperature difference: refers to the temperature difference between the first monitoring area and the second monitoring area at the same time, used to quantify the degree of heat imbalance on both sides of the molten pool.

[0037] Asymmetric solidification triggering conditions: Preset conditions used to determine whether the molten pool faces the risk of asymmetric solidification, which are usually related to the magnitude and direction of the real-time temperature difference.

[0038] Energy distribution state of the energy beam: refers to the energy density distribution of the energy beam in space, such as the location of the energy center of gravity of the light spot, the energy intensity of different regions, etc.

[0039] Symmetrical solidification: refers to the solidification process in which the solidification front of the molten pool advances towards the center at a relatively uniform speed, ultimately forming a weld with a uniform structure and symmetrical stress distribution.

[0040] This application proposes a method for controlling the sealing welding of the vacuum cavity of a thermos cup. This method is used to perform energy beam sealing welding on the vent holes of a workpiece that has been clad and repaired. The clad and repaired workpiece includes a repair area and a normal area, and the material properties of the repair area and the normal area differ.

[0041] During the process of energy beam seal welding, it is necessary to obtain real-time temperature information of the monitoring areas on both sides of the molten pool. The monitoring areas on both sides of the molten pool include the first monitoring area on the side of the molten pool close to the repair area and the second monitoring area on the side of the molten pool close to the normal area. To achieve this goal, a non-contact infrared temperature sensor array can be used. For example, an array consisting of 3 - 5 infrared sensors can be arranged respectively at positions 2 millimeters on both sides of the center line of the molten pool under the welding head, forming two temperature monitoring areas on the left and right. These sensors can be high-sensitivity non-contact infrared sensor arrays. For example, the MLX90614 infrared temperature sensor based on the thermopile principle or a faster infrared array sensor can be used to ensure that the temperature distribution data of the molten pool in the transverse direction can be obtained in real time on a millisecond time scale. These sensors continuously transmit temperature data to a high-speed industrial controller at a frequency of hundreds or even thousands of times per second through the I2C or SPI interface.

[0042] Based on the real-time temperature information, it is necessary to determine the real-time temperature difference between the first monitoring area and the second monitoring area. After receiving the real-time temperature data from the left and right sensor arrays, the high-speed industrial controller immediately compares and analyzes the temperatures on both sides of the molten pool. The controller calculates the average temperature T_left on the side close to the laser cladding repair area (for example, the left sensor array) and the average temperature T_right on the side far from the repair area (i.e., close to the original stainless steel substrate, for example, the right sensor array). Then, the controller continuously calculates and monitors the temperature difference between these two sides, Delta_T = T_left - T_right.

[0043] Subsequently, it is necessary to determine whether the real-time temperature difference meets the preset asymmetric solidification trigger condition. An expected temperature difference range between the two sides of the molten pool is set inside the controller. For example, a threshold Delta_T_threshold can be set, and its value is usually between 10°C and 30°C. The specific value needs to be calibrated according to the material and process. Once it is monitored that the absolute value of the temperature difference Delta_T between the two sides of the molten pool exceeds this preset range (for example, |Delta_T| > Delta_T_threshold), and Delta_T is negative (i.e., T_left < T_right, indicating that the temperature on the side close to the cladding layer is significantly lower than the other side, suggesting that the heat dissipation on this side is too fast), the system will determine that there is a risk of asymmetric solidification in the current molten pool.

[0044] When the asymmetric solidification trigger condition is met, it is necessary to dynamically adjust the energy distribution state of the energy beam to increase the energy input to the monitoring area with a lower temperature in the first monitoring area and the second monitoring area, thereby compensating for the uneven heat dissipation caused by different material properties in the repair area and the normal area, and then ensuring symmetric solidification of the molten pool. When the system determines that there is a risk of asymmetric solidification in the molten pool, it will immediately activate the dynamic energy biasing mechanism. This mechanism will send instructions to the laser or its beam shaping module according to the magnitude and direction of the temperature difference Delta_T to adjust the output of the laser energy in real time. For example, if the laser is equipped with a high-speed galvanometer scanning system or a spatial light modulator (SLM), the controller will adjust these optical elements to shift the energy centroid of the laser spot towards the side with faster heat dissipation and lower temperature. If T_left < T_right, the controller will instruct the galvanometer to move the energy center of the laser spot a small distance d to the left (towards the cladding layer side), or adjust the intensity distribution of the spot through the SLM to increase the energy density on the left side. This offset d can be adjusted proportionally according to the temperature difference Delta_T. For example, d = K_p * Delta_T, where K_p is a proportionality coefficient. Or, if a pulsed laser is used, the controller can adjust the laser pulse sequence. When it is detected that the temperature on one side of the molten pool is low, the controller can apply higher-energy laser pulses on that side or increase the pulse duration on that side to compensate for the local heat loss. For example, during the welding process, if the temperature on the left side is low, the controller can instruct the laser to increase the laser pulse energy in the left area by Delta_E, while keeping the laser pulse energy in the right area unchanged or slightly reducing it by Delta_E to maintain the total energy constant but achieve local biasing. Delta_E can also be adjusted proportionally according to Delta_T. The above processes of sensor data acquisition, temperature difference monitoring, asymmetric solidification judgment, and dynamic energy biasing adjustment will be carried out continuously and rapidly throughout the laser seal welding process, forming a closed-loop real-time control. The response time of the controller is usually between a few milliseconds and dozens of milliseconds, ensuring an immediate response to changes in the molten pool state. In this way, the system can dynamically balance the heat input and heat dissipation on both sides of the molten pool, ensuring that the molten pool maintains a symmetric temperature distribution and a uniform solidification front throughout the welding process.

[0045] The core technical concept of this method lies in its ability to actively compensate for the uneven local heat distribution caused by the laser cladding repair area by dynamically adjusting the laser energy input mode based on the real-time monitoring of temperature differences across the molten pool during laser welding. This method no longer relies on fixed welding parameters but instead uses the lateral thermal balance within the molten pool as a key control objective. By finely adjusting the energy centroid or pulse sequence of the laser spot, it ensures that the molten pool remains symmetrical and uniform throughout the solidification process, thus enabling the formation of high-quality sealing welds even in complex environments with inconsistent material properties.

[0046] The following example will provide a more detailed explanation of the above technical solution: Suppose a thermos cup that has undergone laser cladding repair has an evacuation vent located at the bottom edge, adjacent to an area that has been repaired. The material properties (e.g., thermal conductivity) of this repaired area differ significantly from the original stainless steel substrate (normal area) of the thermos cup. When performing energy beam sealing welding on this vent, if a traditional fixed-parameter welding method is used, the temperature of the molten pool near the repaired area will drop rapidly due to the faster heat dissipation rate in the repaired area compared to the normal area. This leads to asymmetrical solidification of the molten pool, resulting in welding defects.

[0047] To address this issue, the vacuum chamber sealing welding control method for thermos cups described in this application is applied to the welding process. First, during the energy beam sealing welding process, a non-contact infrared temperature sensor array symmetrically arranged along the welding direction acquires real-time temperature information from monitoring areas on both sides of the molten pool. Specifically, the side of the molten pool closer to the repair area is defined as the first monitoring area, and the side closer to the normal area is defined as the second monitoring area. The sensor array continuously collects temperature data from these two areas at a high frequency (e.g., hundreds of times per second) and transmits this real-time temperature information to a high-speed industrial controller.

[0048] Next, the high-speed industrial controller calculates the real-time temperature difference between the first and second monitoring areas based on the received real-time temperature information. For example, the controller calculates the average temperature T_left of the first monitoring area and the average temperature T_right of the second monitoring area, and derives Delta_T = T_left - T_right. This real-time temperature difference Delta_T can intuitively reflect the degree of heat imbalance on both sides of the molten pool.

[0049] Subsequently, the controller determines whether the real-time temperature difference meets the preset asymmetric solidification triggering condition. Before welding, the system has set a temperature difference threshold Delta_T_threshold (e.g., 15°C) according to the material properties and process requirements. If the controller detects that |Delta_T| > Delta_T_threshold and Delta_T is negative (i.e., T_left < T_right), this indicates that the temperature on the side close to the repair area is significantly lower than that on the normal area side, and there is a risk of asymmetric solidification caused by excessive heat dissipation. At this time, the system determines that the asymmetric solidification triggering condition is met.

[0050] Once the asymmetric solidification triggering condition is met, the controller immediately dynamically adjusts the energy distribution state of the energy beam. For example, if it is detected that T_left is significantly lower than T_right, the controller issues an instruction to the laser or its beam shaping module to shift the energy center of gravity of the laser spot towards the first monitored area with a lower temperature (i.e., the side close to the repair area). This offset d is adjusted proportionally according to the magnitude of Delta_T, e.g., d = K_p * |Delta_T|. In this way, more energy is input into the first monitored area with faster heat dissipation, thereby compensating for the uneven heat dissipation caused by different material properties between the repair area and the normal area.

[0051] Through the above closed-loop control process, the system can real-time sense the temperature imbalance on both sides of the molten pool and quickly respond to dynamically adjust the energy distribution of the energy beam. This ensures that the molten pool maintains a symmetric temperature distribution and a uniform solidification front throughout the welding process, thus avoiding welding defects caused by asymmetric solidification and ultimately achieving reliable sealing of the extraction hole.

[0052] The control method for the vacuum cavity sealing welding of the thermos cup in this application effectively solves the problems of uneven heat dissipation and asymmetric solidification of the molten pool caused by the difference in material properties between the repaired area and the normal area during the energy beam sealing welding of the already clad and repaired workpiece. Traditional existing welding methods usually adopt fixed welding parameters and cannot adapt to the change in heat distribution caused by uneven local material properties. For example, in the above example, if fixed parameters are used for welding, the molten pool on the side close to the repair area will cool insufficiently due to excessive heat dissipation, resulting in insufficient penetration or cracks; while on the side far from the repair area, it may overheat due to heat accumulation, causing burn-through or pores.

[0053] This application utilizes a non-contact infrared temperature sensor array symmetrically arranged along the welding direction to acquire temperature information on both sides of the molten pool in real time and accurately, and calculate the real-time temperature difference accordingly. This real-time feedback mechanism is not available in traditional methods. In the example above, when the controller detects that the temperature of the first monitoring area is significantly lower than that of the second monitoring area, it can immediately determine the risk of asymmetric solidification.

[0054] Furthermore, this application can dynamically adjust the energy distribution of the energy beam when the asymmetric solidification triggering condition is met. For example, it can shift the energy center of gravity of the laser spot or adjust the laser pulse sequence to inject more energy into the monitoring area with a lower temperature. This targeted energy compensation strategy can accurately compensate for the heat dissipation differences between different material regions, thereby ensuring symmetrical solidification of the molten pool. Compared with the traditional approach of trying to increase or decrease the laser power as a whole, which is a "loss of some aspects," the dynamic, local energy adjustment mechanism of this application can fundamentally balance the heat input and loss on both sides of the molten pool, significantly improving the welding quality and sealing reliability. Therefore, the technical solution of this application demonstrates significant technological progress and creativity in the precision welding of complex material workpieces.

[0055] In some embodiments, the specific steps in step S2 include: S21. Based on the real-time temperature information of the monitoring areas on both sides of the molten pool, the local temperature gradient characteristics of the first monitoring area and the second monitoring area are identified by analyzing the temperature distribution of the first monitoring area and the second monitoring area respectively. S22. Based on the identified local temperature gradient characteristics, adjust the temperature weights of all preset temperature monitoring points in the first and second monitoring areas respectively, and based on the adjusted weights, obtain the weighted average temperature of the first and second monitoring areas respectively by weighted averaging the real-time temperature information of the first and second monitoring areas respectively. S23. Calculate the weighted average temperature difference between the first monitoring area and the second monitoring area, and use it as the real-time temperature difference.

[0056] The real-time temperature information refers to the raw data set reflecting the surface temperature of the monitoring areas on both sides of the molten pool, acquired by a non-contact infrared temperature sensor array symmetrically arranged along the welding direction. This information typically includes temperature measurements from multiple spatially discrete points. Analyzing the temperature distribution involves processing the real-time temperature information to reveal the spatial variation patterns of temperature within the first and second monitoring areas. This may include interpolating and smoothing the temperature data collected by the sensor array, or constructing a temperature field model. Identifying the local temperature gradient characteristics involves characterizing the intensity and direction of heat loss or accumulation within the monitoring area by calculating the rate of change of temperature in space. For example, the ratio of temperature difference to distance between adjacent temperature monitoring points can be calculated using the finite difference method, or the temperature gradient can be obtained by fitting a temperature curve and then differentiating it. Adjusting the temperature weights involves dynamically assigning different importance coefficients to each preset temperature monitoring point in the first and second monitoring areas based on the identified local temperature gradient characteristics. For example, areas with larger temperature gradients, indicating more active heat loss or input, can be assigned higher weights; while areas with smaller temperature gradients or greater external interference can be assigned lower weights. The weighted average refers to multiplying the real-time temperature information of each temperature monitoring point within the monitoring area by its corresponding adjusted temperature weight, summing all products, and then dividing by the sum of all weights to obtain a weighted average temperature that more accurately reflects the overall thermal state of the monitoring area. Calculating the difference in the weighted average temperature involves arithmetically subtracting the weighted average temperature of the first monitoring area from the weighted average temperature of the second monitoring area to quantify the degree of thermal imbalance on both sides of the molten pool. Using this difference as the real-time temperature difference means that the calculation result will directly serve as the basis for subsequently determining whether the molten pool meets the asymmetric solidification triggering conditions and adjusting the energy beam; its accuracy is crucial for achieving symmetric solidification of the molten pool.

[0057] In the vacuum chamber sealing welding process of a thermos cup, to address the issue of uneven heat distribution caused by the different material properties between the repaired and normal areas of the cladding workpiece, this application refines the real-time temperature difference between the two sides of the molten pool to ensure the accuracy of subsequent energy adjustments. Specifically, during the energy beam sealing welding process, firstly, a non-contact infrared temperature sensor array symmetrically arranged along the welding direction continuously acquires real-time temperature information of the monitoring areas on both sides of the molten pool. This real-time temperature information forms the basis for subsequent analysis. Next, to more accurately reflect the true thermal balance state on both sides of the molten pool, this application performs in-depth processing on this real-time temperature information. Specifically, based on the acquired real-time temperature information, the system analyzes the temperature distribution of the first and second monitoring areas and identifies their respective local temperature gradient characteristics. This step reveals the severity and direction of temperature changes on both sides of the molten pool, thereby capturing localized thermal unevenness more precisely. Subsequently, based on the identified local temperature gradient characteristics, the system dynamically adjusts the temperature weights of all preset temperature monitoring points in both the first and second monitoring areas. This weighting mechanism assigns higher weights to monitoring points that better reflect heat dissipation differences, effectively eliminating the interference of irrelevant temperature data on the final temperature result. Based on this, by weighted averaging the real-time temperature information of the first and second monitoring areas, a weighted average temperature that better reflects the actual temperature conditions on both sides of the molten pool can be obtained. Finally, the difference between the weighted average temperature of the first and second monitoring areas is calculated and used as the final real-time temperature difference. Through this refined method for determining temperature differences, this application overcomes the problems of complex internal heat convection in the molten pool, nonlinear distribution of material properties, and the inability of limited sensor data to fully capture local thermal unevenness in traditional methods. Compared to simply calculating the average temperature difference, this application introduces temperature distribution analysis and local temperature gradient feature identification, and dynamically adjusts the weights of temperature monitoring points accordingly, enabling the determined real-time temperature difference to more comprehensively and accurately reflect the true thermal imbalance state on both sides of the molten pool. This more accurate real-time temperature difference information provides a reliable basis for subsequent judgment on whether the asymmetric solidification triggering conditions are met, and further guides the dynamic adjustment of the energy beam. This allows for more precise compensation for uneven heat dissipation caused by differences in material properties between the repair area and the normal area. Therefore, the solution proposed in this application can effectively assist in accurately compensating for uneven heat dissipation on both sides through energy adjustment, ensuring symmetrical solidification of the molten pool, and thus significantly improving the quality and reliability of the vacuum chamber sealing welding of the thermos cup.

[0058] The following is a concrete example. During laser sealing welding of the vacuum chamber evacuation port of a thermos cup, a high-speed industrial controller, such as a Siemens S7-1500 series PLC or a Beckhoff TwinCAT system, receives real-time temperature data from non-contact infrared temperature sensor arrays on both sides of the molten pool. After receiving the real-time temperature data from the two sensor arrays, the high-speed industrial controller immediately compares and analyzes the temperatures on both sides of the molten pool. Assume that each monitoring area (e.g., the first and second monitoring areas) consists of three infrared sensors, measuring temperature values ​​T1, T2, and T3 respectively. First, the controller analyzes the temperature distribution of the first and second monitoring areas based on this real-time temperature information. For example, for the first monitoring area, the temperature differences between adjacent sensors, such as (T2-T1) and (T3-T2), can be calculated to identify local temperature gradient characteristics. If the absolute value of (T2-T1) is large, it indicates that the temperature in that area changes drastically, possibly indicating rapid heat dissipation. Next, based on the identified local temperature gradient characteristics, the controller adjusts the temperature weights of all preset temperature monitoring points in both the first and second monitoring areas. For example, if sensor T1 in the first monitoring area is close to the repair area and has a large temperature gradient with T2, T1 can be assigned a higher weight W1, while T2 and T3 can be assigned relatively lower weights W2 and W3. Specifically, the weights can be dynamically adjusted based on the absolute value of the temperature gradient; for example, the larger the gradient, the higher the weight. Then, based on the adjusted weights, the controller performs a weighted average of the real-time temperature information of the first and second monitoring areas. For example, the weighted average temperature T_avg1 of the first monitoring area is calculated as (T1*W1 + T2*W2 + T3*W3) / (W1 + W2 + W3). Similarly, the weighted average temperature T_avg2 of the second monitoring area is calculated. Finally, the controller calculates the difference between the weighted average temperatures of the first and second monitoring areas, i.e., Delta_T = T_avg1 - T_avg2, and uses this result as the real-time temperature difference. For example, if T_avg1 is 1200°C and T_avg2 is 1230°C, the real-time temperature difference is -30°C. This difference value will be used to subsequently determine whether the preset asymmetric solidification triggering condition is met. The controller calculates the average temperature T_left on the side closer to the laser cladding repair area (e.g., the left sensor array) and the average temperature T_right on the side farther from the repair area (i.e., closer to the original stainless steel substrate, e.g., the right sensor array). Then, the controller continuously calculates and monitors the temperature difference between these two sides: Delta_T = T_left - T_right.

[0059] Through the above technical solution, this application effectively solves the problem that during the vacuum cavity sealing welding process of a thermos cup after laser cladding repair, the complex internal heat convection and nonlinear distribution of material properties within the molten pool mean that the surface temperature information collected by a limited number of sensor arrays cannot fully represent the true thermal balance state of the deep layer or the whole of the molten pool. This results in the calculation of real-time temperature differences on both sides of the molten pool failing to adequately capture localized thermal unevenness. This application analyzes the temperature distribution and identifies local temperature gradient characteristics of the real-time temperature information in the monitoring areas on both sides of the molten pool, dynamically adjusts the weights of the temperature monitoring points accordingly, and then performs a weighted average to obtain a more accurate and representative real-time temperature difference. This refined method of determining temperature differences can more comprehensively and accurately reflect the true thermal imbalance state on both sides of the molten pool, providing a reliable and precise basis for subsequent judgment on whether energy beam adjustment is necessary. Therefore, this application can assist in subsequent energy adjustment to accurately compensate for uneven heat dissipation on both sides, ensuring symmetrical solidification of the molten pool, thereby significantly improving the quality and reliability of vacuum cavity sealing welding of the thermos cup and reducing the leakage rate and scrap rate of the repaired product.

[0060] In some embodiments, the specific steps in step S3 include: S31. Before performing sealing welding, the local thermophysical properties of the surrounding area of ​​the vent are detected to obtain the local thermophysical property information of the repair area and the normal area respectively; the local thermophysical property information includes thermal conductivity and heat capacity. S32. Dynamically determine the asymmetric solidification triggering conditions based on local thermophysical property information; the asymmetric solidification triggering conditions include temperature difference thresholds; S33. Based on the determined asymmetric solidification triggering condition, determine whether the real-time temperature difference satisfies the asymmetric solidification triggering condition.

[0061] This method, before sealing welding, first probes the local thermophysical properties of the area surrounding the evacuation port. The aim is to obtain the material's thermal characteristics in this area, particularly the differences between the repaired and normal areas, providing accurate baseline data for subsequent welding control. Pre-welding probes avoid interference with the welding process and ensure real-time data accuracy. Local thermophysical property probes can be implemented using various techniques. For example, non-contact or micro-contact measurement techniques such as the transient planar heat source method (TPS) or laser flare method (LFA) can be used. These methods can rapidly measure the thermal conductivity and thermal diffusivity of the material in a localized area, thereby calculating the heat capacity. Alternatively, infrared thermal imaging combined with reverse heat conduction analysis can be used. By applying a known thermal pulse to a localized area and capturing the surface temperature change over time using a high-resolution infrared camera, the thermal conductivity and heat capacity of that area can be derived through numerical simulation and optimization algorithms. The acquired local thermophysical property information, namely thermal conductivity and heat capacity, are key parameters characterizing the material's heat conduction and heat storage capabilities; their differences directly affect the degree of heat dissipation unevenness on both sides of the molten pool.

[0062] Subsequently, based on the acquired local thermophysical property information, the asymmetric solidification triggering condition is dynamically determined. The core of this step lies in adaptively setting the conditions for determining whether asymmetric solidification occurs in the molten pool based on the actually measured thermophysical properties of the workpiece. This overcomes the problem that traditional fixed thresholds cannot adapt to differences in different workpieces, making the triggering conditions more precise and flexible. Dynamically determining the asymmetric solidification triggering condition can be achieved by establishing a welding thermal process model based on finite element analysis (FEA) or computational fluid dynamics (CFD). The thermal conductivity and heat capacity of the detected repair and normal regions are used as input parameters to simulate the temperature distribution and solidification behavior on both sides of the molten pool under different energy beams, thereby predicting the temperature difference at which asymmetric solidification will occur and dynamically setting the temperature difference threshold. Alternatively, machine learning algorithms can be used. By collecting a large amount of welding data from workpieces with different material properties, a predictive model can be trained to predict the most suitable temperature difference threshold based on the new workpiece thermophysical properties. The temperature difference threshold is a key parameter for determining whether the temperature difference between the two sides of the molten pool has reached the point where energy adjustment is required. It is a dynamic value, no longer fixed, but adjusted according to the actual thermophysical property differences of the workpiece, so as to more accurately reflect the degree of uneven heat dissipation of the current workpiece.

[0063] Finally, based on the determined asymmetric solidification triggering condition, it is determined whether the real-time temperature difference meets the asymmetric solidification triggering condition. This step is the decision-making link in the real-time control loop. It uses the dynamically determined asymmetric solidification triggering condition to evaluate the temperature difference between the two sides of the molten pool monitored in real time, thereby deciding whether to initiate dynamic adjustment of the energy beam. The controller can compare the real-time calculated temperature difference between the two sides of the molten pool with the dynamically determined temperature difference threshold. For example, if the absolute value of the real-time temperature difference is greater than the threshold, and the side with the lower temperature is the repair area, then it is determined that the triggering condition is met. Alternatively, a fuzzy logic controller can be used, taking the real-time temperature difference and the dynamic threshold as input, and outputting a judgment result indicating the degree to which the triggering condition is met through preset fuzzy rules and membership functions, thereby controlling subsequent energy adjustments more finely.

[0064] This application's solution accurately assesses the potential uneven heat dissipation on both sides of the molten pool by precisely acquiring local thermophysical properties such as thermal conductivity and heat capacity of the repair and normal areas before energy beam sealing welding. Based on this, a dynamically set temperature difference threshold can more accurately reflect the actual needs of the current workpiece, avoiding misjudgments or omissions that may occur with fixed thresholds. During welding, once the real-time temperature difference reaches or exceeds this dynamic threshold, the system can intervene in time, adjusting the energy distribution of the energy beam to deliver more energy to the side with faster heat dissipation and lower temperature, thereby balancing the heat input and loss on both sides of the molten pool and ensuring that the molten pool always maintains a symmetrical temperature distribution and a uniform solidification front. This mechanism enables the entire welding process to adaptively respond to the thermal differences of different repaired workpieces, significantly improving the quality and reliability of the weld.

[0065] The following is illustrated by a specific example. Before performing energy beam seal welding on the air extraction holes of the repaired and clad workpiece, the surrounding area of the air extraction holes can first be scanned using a local thermophysical property detection device. For example, a transient plane heat source method sensor can be used, and its probe is respectively contacted with the surfaces of the repaired area and the normal area. By applying a short thermal pulse and monitoring the surface temperature response curve, the thermal conductivity and heat capacity of these two areas can be accurately measured. Assume that the thermal conductivity of the repaired area is λ_repair, the heat capacity is C_repair, the thermal conductivity of the normal area is λ_normal, and the heat capacity is C_normal. After obtaining this local thermophysical property information, a high-speed industrial controller, such as the Siemens S7-1500 series PLC, will dynamically calculate the asymmetric solidification trigger condition based on these parameters. Specifically, the controller can have a built-in heat conduction model or a look-up table method. According to the differences in λ_repair, C_repair, λ_normal, and C_normal, it predicts the maximum allowable temperature difference on both sides of the molten pool under the current welding parameters. For example, if the thermal conductivity of the repaired area is much higher than that of the normal area, the controller will correspondingly increase the temperature difference threshold Delta_T_threshold to allow a larger real-time temperature difference because the clad layer will dissipate heat faster. Conversely, if the difference is small, the threshold will be set more strictly. An expected temperature difference range on both sides of the molten pool is set inside the controller. For example, a threshold Delta_T_threshold can be set, and its value is usually between 10°C and 30°C. The specific value needs to be calibrated according to the material and process. The controller will dynamically adjust Delta_T_threshold to a specific value within this range according to the actual detection results, such as 15°C or 25°C. During the welding process, the non-contact infrared temperature sensor array continuously obtains the real-time temperature information on both sides of the molten pool and calculates the real-time temperature difference Delta_T. The controller will then judge whether the real-time temperature difference Delta_T meets the asymmetric solidification trigger condition based on the dynamically determined Delta_T_threshold. For example, the controller will judge whether the absolute value of the real-time temperature difference Delta_T is greater than the dynamically set Delta_T_threshold. Once it is monitored that the absolute value of the temperature difference Delta_T on both sides of the molten pool exceeds this preset range (for example, |Delta_T|>Delta_T_threshold), and Delta_T is negative (that is, T_left<T_right, indicating that the temperature on the side close to the clad layer is significantly lower than the other side, suggesting that the heat dissipation on this side is too fast), the system will judge that there is a risk of asymmetric solidification in the current molten pool, that is, the asymmetric solidification trigger condition is met, and immediately start the dynamic adjustment mechanism of the energy beam.

[0066] Through the above technical solution, this application addresses the issue of uneven heat dissipation in the vacuum cavity sealing welding control method for thermos cups, which is caused by differences in material properties between the repaired and normal areas of the cladding repaired workpiece. It achieves adaptive dynamic adjustment of the asymmetric solidification triggering conditions. Specifically, before sealing welding, local thermophysical properties are detected in the area surrounding the evacuation port to obtain key information such as the thermal conductivity and heat capacity of the repaired and normal areas, enabling the system to accurately grasp the actual thermal characteristics of the workpiece. Based on this precise local thermophysical property information, the asymmetric solidification triggering conditions, especially the temperature difference threshold, are dynamically determined, overcoming the limitations of traditional fixed thresholds that cannot adapt to different repair scenarios. This dynamic adjustment mechanism ensures that the triggering conditions accurately match the degree of uneven heat dissipation of the current workpiece, thereby significantly improving the accuracy of judging whether the molten pool faces the risk of asymmetric solidification. Compared with methods that rely solely on preset fixed triggering conditions, this solution effectively avoids misjudgments or omissions caused by the diversity of material properties, ensuring intervention only when energy beam adjustment is truly needed, and avoiding unnecessary adjustments when not required. This allows for more timely and precise dynamic adjustment of the energy beam, thereby more effectively compensating for uneven heat dissipation on both sides of the molten pool and ensuring symmetrical solidification of the molten pool. Ultimately, this solution can significantly improve the sealing welding quality of repaired workpieces, reduce welding defects, increase product qualification rate, and extend the service life of insulated cups.

[0067] In some embodiments, the specific steps in step S32 include: S321. Evaluate the effect of the difference in thermal conductivity between the repaired area and the normal area on the rate of heat loss from the molten pool, and obtain the first evaluation result; S322. Evaluate the impact of the difference in heat capacity between the repaired area and the normal area on the heat storage capacity of the molten pool, and obtain the second evaluation result; S323. Determine the weighting coefficients based on the material properties of the repaired area and the normal area; S324. Based on the determined weighting coefficients, and according to the first evaluation result and the second evaluation result, calculate the temperature difference threshold by weighted combination.

[0068] Specifically, in assessing the impact of the difference in thermal conductivity between the repaired area and the normal area on the rate of heat loss from the molten pool, and obtaining the first evaluation result, this step aims to quantify the influence of different thermal conductivityes on the rate of heat loss from the molten pool. One approach is to use numerical simulation software, such as finite element analysis (FEA) or computational fluid dynamics (CFD) tools, to establish a heat conduction model of the molten pool region. By inputting the thermal conductivity of the repaired area and the normal area, the heat loss on both sides of the molten pool under the action of an energy beam is simulated, thereby determining the specific degree of influence of the difference in thermal conductivity on the rate of heat loss, and using this as the first evaluation result. Another approach is to combine experimental measurements with empirical modeling. Under controlled experimental conditions, samples with different differences in thermal conductivity are simulated for welding, and the temperature decay curves on both sides of the molten pool are monitored in real time. Based on these experimental data, an empirical model or lookup table can be established to correlate the difference in thermal conductivity with the change in the rate of heat loss from the molten pool, thereby obtaining the first evaluation result.

[0069] In assessing the impact of the difference in heat capacity between the repaired area and the normal area on the heat storage capacity of the molten pool, and obtaining the second assessment result, this step aims to quantify the influence of different heat capacities on the heat absorption and storage capacity of the molten pool. One approach is to utilize numerical simulation, considering the respective heat capacity parameters of the repaired and normal areas in a heat conduction model. By simulating the energy beam heating process, the difference in temperature rise when the two sides of the molten pool absorb the same amount of heat, or the difference in heat release during cooling, is observed to assess the impact of the heat capacity difference on the heat storage capacity, and this is used as the second assessment result. Another approach is to employ thermal analysis techniques such as differential scanning calorimetry (DSC) to accurately measure the heat capacity of the repair material and the substrate. These measurements are then substituted into a thermodynamic model to calculate the difference in heat storage capacity between the two sides of the molten pool under a specific heat input, thereby obtaining the second assessment result.

[0070] When determining weighting coefficients based on the material properties of the repaired area and the normal area, this step aims to dynamically adjust the relative importance of differences in thermal conductivity and heat capacity when calculating temperature difference thresholds, according to the characteristics of the actual material combination. One implementation is to establish a material property database pre-stores the weighting coefficients corresponding to different combinations of repair materials and substrates. These weighting coefficients can be pre-calibrated using extensive experimental data, numerical simulations, or expert experience. Once the system identifies the material properties of the repaired and normal areas of the current welded workpiece, it can query and retrieve the corresponding weighting coefficients from the database. Another implementation is to employ a rule-based expert system or a fuzzy logic system. This system dynamically calculates the weighting coefficients applicable to the current material combination based on the input material properties (e.g., the relative magnitude of differences in thermal conductivity, the relative magnitude of differences in heat capacity, etc.) through preset logical rules or fuzzy inference mechanisms.

[0071] When calculating the temperature difference threshold based on the determined weighting coefficients and the first and second evaluation results through a weighted combination, this step aims to comprehensively consider the two evaluation results to generate a temperature difference threshold that accurately reflects the current thermal environment. One implementation method is to use a linear weighted combination method: Temperature Difference Threshold = (Weighting Coefficient_Thermal Conductivity * First Evaluation Result) + (Weighting Coefficient_Heat Capacity * Second Evaluation Result). Here, the weighting coefficients_thermal conductivity and_heat capacity are weighting coefficients determined based on material properties, and the first and second evaluation results are the evaluation values ​​obtained in the aforementioned steps. Another implementation method is to use a nonlinear weighted combination model, such as a polynomial or exponential function, to more accurately capture the complex influence of thermal conductivity and heat capacity differences on the temperature difference threshold. This model can be trained and optimized on a large amount of experimental data using machine learning algorithms to adapt to a wider range of material combinations and welding conditions.

[0072] This application proposes a method that independently assesses the impact of differences in thermal conductivity and heat capacity on the thermal behavior of the molten pool from both sides. Weighting coefficients are determined based on the actual material properties of the repair and normal areas, and a weighted combination is used to calculate the temperature difference threshold. This method can more precisely capture the differences in heat loss and storage capacity caused by inconsistent material properties on both sides of the molten pool. Differences in thermal conductivity directly affect the rate at which heat is conducted from the molten pool outwards, while differences in heat capacity determine the material's ability to absorb and store heat; both together determine the temperature dynamics on both sides of the molten pool. By evaluating these factors separately and assigning different weights based on actual material properties, the calculated temperature difference threshold can accurately reflect the true thermal imbalance state of the current welding environment. This dynamic and precise threshold provides a reliable basis for subsequent dynamic adjustments of the energy beam, making the timing and magnitude of energy adjustments more accurate, thereby effectively compensating for the uneven heat dissipation caused by differences in material properties between the repair and normal areas.

[0073] In some embodiments, the specific steps in step S33 include: S331. Determine whether the absolute value of the real-time temperature difference is greater than the temperature difference threshold; S332. When the absolute value of the real-time temperature difference is greater than the temperature difference threshold, and the weighted average temperature of the first monitoring area is lower than the weighted average temperature of the second monitoring area, it is determined that the asymmetric solidification triggering condition is met.

[0074] During energy beam sealing welding, to effectively identify significant uneven heat dissipation on both sides of the molten pool, it is necessary to quantitatively assess the temperature difference between the monitored areas on both sides of the molten pool, acquired in real time. This judgment step aims to initially screen out cases where the temperature difference reaches a certain level, avoiding unnecessary energy adjustments to minor temperature fluctuations that are normal during welding. Its function is to ensure that the next step of fine-grained judgment is only performed when the degree of uneven heat dissipation is sufficient to affect the symmetrical solidification of the molten pool. Specifically, this judgment can be implemented using a high-speed industrial controller. For example, the controller can receive real-time temperature information acquired by a non-contact infrared temperature sensor array and calculate the real-time temperature difference between the first and second monitoring areas. Subsequently, the logic unit inside the controller compares the absolute value of this real-time temperature difference with a preset temperature difference threshold. If the absolute value of the real-time temperature difference exceeds the threshold, it indicates that the uneven heat dissipation on both sides of the molten pool has reached a level requiring attention. As another implementation, this judgment can also be performed using a dedicated hardware comparator circuit. This circuit can receive analog or digital signals representing the temperature difference in real time and compare them with a signal representing the temperature difference threshold, thereby quickly outputting a Boolean signal indicating whether the absolute value of the real-time temperature difference is greater than the preset threshold. This hardware implementation provides a faster response time to meet the extremely high real-time requirements of welding processes.

[0075] Based on confirming that the absolute value of the real-time temperature difference exceeds a preset threshold, this judgment step further incorporates consideration of the directionality of the temperature difference. Its purpose is to accurately identify the problem of excessive heat dissipation caused by differences in material properties in the repair area, thereby avoiding misjudgments and unnecessary energy adjustments. By combining the magnitude and direction of the temperature difference, it ensures that the asymmetric solidification condition is triggered only in scenarios where energy compensation is truly required. Specifically, in a high-speed industrial controller, when the absolute value of the real-time temperature difference is determined to be greater than the temperature difference threshold, the controller further compares the weighted average temperature of the first monitoring area with the weighted average temperature of the second monitoring area. If the weighted average temperature of the first monitoring area is lower than the weighted average temperature of the second monitoring area, it indicates that the heat dissipation rate is faster on the side closer to the repair area than on the side closer to the normal area, and only then is the asymmetric solidification trigger condition determined to be met. As another implementation method, this judgment logic can also be implemented through a software algorithm in an embedded system. This algorithm can contain multiple nested conditional statements, first determining whether the absolute value of the temperature difference exceeds the threshold, and then, based on this, further determining whether the weighted average temperature of the first monitoring area is lower than the weighted average temperature of the second monitoring area. The system will only output a signal that satisfies the asymmetric solidification triggering condition when both of these conditions are met. This software implementation provides greater flexibility, facilitating parameter adjustments and logic optimization based on actual process requirements.

[0076] Overall, this scheme breaks down the trigger judgment into two sequential judgment steps. Combining the magnitude and direction of the temperature difference to determine whether the trigger condition is met improves the accuracy of the trigger judgment, avoids false triggers that could affect welding quality, and ensures that energy adjustment is only initiated when there is a genuine need to compensate for uneven heat dissipation. The first step determines whether the absolute value of the real-time temperature difference exceeds a pre-determined temperature difference threshold. Only when the temperature difference between the two sides exceeds the threshold, indicating that the current uneven heat dissipation is sufficient to affect the symmetrical solidification of the molten pool, does the next judgment proceed. This step filters out the normal minor temperature fluctuations that occur during welding, avoiding unnecessary adjustments and maintaining the stability of the welding process. The second step, based on the absolute value of the temperature difference exceeding the threshold, further determines the direction of the temperature difference to confirm whether the temperature in the first monitoring area corresponding to the repair area is lower. Only when the temperature is lower on the repair area side does it indicate that the different material properties of the repair area are indeed causing faster heat dissipation, a scenario that truly requires energy compensation. This eliminates the false judgment of lower temperatures in normal areas, ensuring that the energy distribution adjustment operation accurately corresponds to the actual uneven heat dissipation problem, providing an accurate judgment basis for obtaining a symmetrically solidified molten pool and forming a qualified and reliable sealing weld. This judgment mechanism, working in conjunction with the energy beam sealing welding control method, enables the system to more accurately determine when dynamic adjustments to the energy beam's distribution are needed. When the asymmetric solidification trigger condition is met—that is, when the absolute value of the real-time temperature difference exceeds a threshold and the temperature is lower on the side closer to the repair area—the controller immediately initiates energy adjustment, increasing the energy input to the lower-temperature monitoring area. This precise judgment and timely energy compensation effectively offset the uneven heat dissipation caused by the different material properties between the repair and normal areas, thereby ensuring symmetrical solidification of the molten pool and forming a dense and reliable sealing weld.

[0077] In some embodiments, the specific steps in step S4 include: S4A1. Based on the real-time temperature difference between the first and second monitoring areas, control the energy center of the energy beam to shift towards the monitoring area with the lower temperature in the first and second monitoring areas; Alternatively, S4B1. Based on the magnitude of the real-time temperature difference between the first and second monitoring areas, adjust the pulse frequency or pulse width of the energy beam in the monitoring area with the lower temperature in the first and second monitoring areas.

[0078] The measurement of the real-time temperature difference between the first and second monitoring areas refers to the system continuously monitoring and calculating the real-time temperature difference between the two sides of the molten pool, obtaining the numerical value of this difference. This value directly reflects the degree of uneven heat loss on both sides of the molten pool. This difference is a key input parameter for subsequent energy adjustment, ensuring the accuracy of energy compensation. Shifting the energy center of gravity of the energy beam towards the lower-temperature monitoring area within the first and second monitoring areas involves changing the position of the energy beam on the workpiece surface, bringing the central energy region of the beam closer to the lower-temperature side. This shift can be achieved in various ways. For example, a high-speed galvanometer scanning system can be used to precisely control the deflection angle of the galvanometer, causing a slight displacement of the laser spot's energy center; alternatively, a spatial light modulator (SLM) can be used to adjust the intensity distribution of the spot, increasing the energy density on the lower-temperature side, thus effectively shifting the energy center of gravity. Adjusting the pulse frequency or pulse width of the energy beam in the lower-temperature monitoring area within the first and second monitoring areas refers to, for pulsed lasers, adjusting the local energy input by changing the repetition frequency of the laser pulses or the duration of a single pulse. When the temperature in a certain monitoring area is low, the laser pulse frequency in that area can be increased, that is, more pulses can be emitted per unit time, or the width of a single pulse can be increased, that is, the laser action time can be extended. Both of these methods can effectively increase the total energy received in that area per unit time, thereby compensating for heat loss.

[0079] This application's solution, based on the aforementioned real-time acquisition of temperature information from monitoring areas on both sides of the molten pool, determination of real-time temperature differences, and assessment of whether asymmetric solidification triggering conditions are met, further provides two selectable and practical energy adjustment implementation paths. When the system determines that there is a risk of asymmetric solidification in the molten pool, it immediately activates a dynamic energy bias mechanism. This mechanism sends instructions to the laser or its beam shaping module based on the magnitude and direction of the real-time temperature difference to adjust the laser energy output in real time. Specifically, if the real-time temperature difference between the two sides of the molten pool shows that the temperature on one side is significantly lower, indicating faster heat dissipation on that side, the system will proportionally control the energy center of gravity of the energy beam to shift towards the lower-temperature side based on the absolute value of the temperature difference. This shift can directly change the energy distribution of the energy beam, allowing more energy to naturally concentrate in the area with faster heat dissipation and lower temperature, thereby accurately completing heat compensation. Alternatively, the system can adjust the pulse frequency or pulse width of the energy beam in the monitoring area with the lower temperature based on the magnitude of the real-time temperature difference. By increasing the pulse frequency or pulse width in this area, the total amount of energy received per unit time in this area can be directly changed, specifically increasing the energy input on the low-temperature side. The aforementioned processes of sensor data acquisition, temperature difference monitoring, asymmetric solidification judgment, and dynamic energy bias adjustment are continuously and rapidly performed throughout the laser sealing welding process, forming a closed-loop real-time control. The controller's response time is typically between a few milliseconds and tens of milliseconds, ensuring immediate response to changes in the molten pool state. In this way, the system can dynamically balance heat input and heat loss on both sides of the molten pool, ensuring that the molten pool maintains a symmetrical temperature distribution and a uniform solidification front throughout the entire welding process.

[0080] The following is a concrete example. During laser sealing welding of the evacuation port of a thermos cup's vacuum chamber, suppose that real-time temperature information obtained through a non-contact infrared temperature sensor array shows that the weighted average temperature T_left of the first monitoring area near the repair area is lower than the weighted average temperature T_right of the second monitoring area near the normal area, and the absolute value of the real-time temperature difference Delta_T between the two is greater than a preset temperature difference threshold, indicating a risk of asymmetric solidification of the molten pool. In this case, the controller can, based on the magnitude of Delta_T, instruct the high-speed galvanometer scanning system equipped with the laser to move the energy center of the laser spot a small distance d to the left (i.e., the first monitoring area, near the repair area). This offset d can be adjusted proportionally according to Delta_T, for example, d = K_p * Delta_T, where K_p is a proportionality coefficient. In this way, more laser energy is guided to the lower-temperature first monitoring area to compensate for the additional heat loss caused by the different material properties of the repair area. As another specific implementation, if a pulsed laser is used, when the temperature of the first monitoring area is detected to be too low, the controller can instruct the laser to apply a higher-energy laser pulse to the first monitoring area. For example, this can be done by increasing the pulse frequency or pulse width in that area, thereby increasing the total energy received by that area per unit time. For instance, the laser can be instructed to increase the laser pulse energy in the first monitoring area by Delta_E, while keeping the laser pulse energy in the second monitoring area unchanged or slightly decreasing Delta_E, thus maintaining a constant total energy while achieving local bias. Delta_E can also be adjusted proportionally based on Delta_T.

[0081] Through the above technical solution, this application provides a clear and feasible implementation method for energy adjustment, effectively solving the welding quality problem caused by the lack of precise energy adjustment methods in traditional solutions. By dynamically controlling the energy center of gravity shift of the energy beam spot or adjusting the pulse frequency / pulse width according to the real-time temperature difference, the heat dissipation compensation needs of the repair area and the normal area can be precisely matched, allowing more energy to be naturally concentrated in the area with faster heat dissipation and lower temperature, thereby ensuring symmetrical solidification of the molten pool. This significantly improves the quality and reliability of sealing welding, reduces air leakage and product scrap rate caused by welding defects, and, because it provides two optional adjustment paths, it can be adapted to different types of energy beam welding equipment, further enhancing the applicability and practicality of the solution.

[0082] Reference Appendix Figure 2This invention provides a vacuum chamber sealing welding control system for a thermos cup (this thermos cup vacuum chamber sealing welding control system adopts the thermos cup vacuum chamber sealing welding control method of the above embodiment, the specific process is referred to the corresponding steps above), used for energy beam sealing welding of the vent hole of a workpiece that has been clad and repaired. The clad and repaired workpiece includes a repair area and a normal area, and the repair area and the normal area have different material properties. The thermos cup vacuum chamber sealing welding control system includes: The temperature monitoring unit 100 is used to acquire real-time temperature information of the monitoring areas on both sides of the molten pool during the energy beam sealing welding process; the monitoring areas on both sides of the molten pool include a first monitoring area on the side of the molten pool closer to the repair area and a second monitoring area on the side of the molten pool closer to the normal area. The calculation unit 200 is used to determine the real-time temperature difference between the first monitoring area and the second monitoring area based on real-time temperature information. Logic unit 300 is used to determine whether the real-time temperature difference meets the preset asymmetric solidification triggering condition; The controller 400 is used to dynamically adjust the energy distribution state of the energy beam when the asymmetric solidification triggering condition is met, so as to increase the energy input to the monitoring area with a lower temperature in the first monitoring area and the second monitoring area, thereby compensating for the uneven heat dissipation caused by the different material properties between the repair area and the normal area, and thus ensuring that the molten pool achieves symmetrical solidification.

[0083] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0084] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling the sealing welding of a vacuum cavity in a thermos cup, used for energy beam sealing welding of the vent hole of a repaired workpiece, wherein the repaired workpiece includes a repair area and a normal area, the repair area and the normal area having different material properties, characterized in that... The method for controlling the sealing welding of the vacuum chamber of the thermos cup includes the following steps: S1. During the energy beam sealing welding process, real-time temperature information of the monitoring areas on both sides of the molten pool is obtained; the monitoring areas on both sides of the molten pool include a first monitoring area on the side of the molten pool closer to the repair area, and a second monitoring area on the side of the molten pool closer to the normal area; S2. Determine the real-time temperature difference between the first monitoring area and the second monitoring area based on the real-time temperature information; S3. Determine whether the real-time temperature difference meets the preset asymmetric solidification triggering condition; S4. When the asymmetric solidification triggering condition is met, the energy distribution state of the energy beam is dynamically adjusted to increase the energy input to the monitoring area with lower temperature in the first monitoring area and the second monitoring area, thereby compensating for the uneven heat dissipation caused by the different material properties between the repair area and the normal area, and thus ensuring that the molten pool achieves symmetrical solidification. The specific steps in step S3 include: S31. Before performing sealing welding, the local thermophysical properties of the surrounding area of ​​the vent are detected to obtain the local thermophysical property information of the repair area and the normal area respectively; the local thermophysical property information includes thermal conductivity and heat capacity; the asymmetric solidification triggering condition includes a temperature difference threshold. S32. Dynamically determine the asymmetric solidification triggering condition based on the local thermophysical property information; S33. Based on the determined asymmetric solidification triggering condition, determine whether the real-time temperature difference satisfies the asymmetric solidification triggering condition; The specific steps in step S32 include: S321. Evaluate the effect of the difference in thermal conductivity between the repaired area and the normal area on the rate of heat loss from the molten pool, and obtain a first evaluation result; S322. Evaluate the impact of the difference in heat capacity between the repaired area and the normal area on the heat storage capacity of the molten pool, and obtain a second evaluation result; S323. Determine the weighting coefficient based on the material properties of the repaired area and the normal area; S324. Based on the determined weighting coefficients, the temperature difference threshold is calculated by weighted combination according to the first evaluation result and the second evaluation result; The specific steps in step S33 include: S331. Determine whether the absolute value of the real-time temperature difference is greater than the temperature difference threshold; S332. When the absolute value of the real-time temperature difference is greater than the temperature difference threshold, and the weighted average temperature of the first monitoring area is lower than the weighted average temperature of the second monitoring area, it is determined that the asymmetric solidification triggering condition is met.

2. The method for controlling the sealing welding of the vacuum cavity of a thermos cup according to claim 1, characterized in that, The specific steps in step S1 include: S11. The real-time temperature information is obtained by using a non-contact infrared temperature sensor array arranged symmetrically along the welding direction.

3. The method for controlling the sealing welding of the vacuum cavity of a thermos cup according to claim 1, characterized in that, The specific steps in step S2 include: S21. Based on the real-time temperature information of the monitoring areas on both sides of the molten pool, by analyzing the temperature distribution of the first monitoring area and the second monitoring area respectively, the local temperature gradient characteristics corresponding to the first monitoring area and the second monitoring area are identified. S22. Based on the identified local temperature gradient characteristics, adjust the temperature weights of all preset temperature monitoring points in the first monitoring area and the second monitoring area respectively, and based on the adjusted weights, obtain the weighted average temperature of the first monitoring area and the second monitoring area respectively by weighted averaging the real-time temperature information of the first monitoring area and the second monitoring area respectively. S23. Calculate the difference in weighted average temperature between the first monitoring area and the second monitoring area, and use it as the real-time temperature difference.

4. The method for controlling the sealing welding of the vacuum cavity of a thermos cup according to claim 1, characterized in that, The specific steps in step S4 include: S4A1. Based on the real-time temperature difference between the first monitoring area and the second monitoring area, control the energy center of gravity of the energy beam to shift towards the monitoring area with the lower temperature in the first monitoring area and the second monitoring area.

5. The method for controlling the sealing welding of the vacuum cavity of a thermos cup according to claim 1, characterized in that, The specific steps in step S4 include: S4B1. Based on the real-time temperature difference between the first monitoring area and the second monitoring area, adjust the pulse frequency or pulse width of the energy beam in the monitoring area with the lower temperature between the first monitoring area and the second monitoring area.

6. A vacuum chamber sealing welding control system for a thermos cup, employing the vacuum chamber sealing welding control method as described in any one of claims 1-5, for performing energy beam sealing welding on the vent holes of a repaired workpiece, wherein the repaired workpiece includes a repair area and a normal area, the repair area and the normal area having different material properties, characterized in that... The vacuum chamber sealing welding control system for the thermos cup includes: The temperature monitoring unit is used to acquire real-time temperature information of the monitoring areas on both sides of the molten pool during the energy beam sealing welding process; the monitoring areas on both sides of the molten pool include a first monitoring area on the side of the molten pool closer to the repair area, and a second monitoring area on the side of the molten pool closer to the normal area. The calculation unit is used to determine the real-time temperature difference between the first monitoring area and the second monitoring area based on the real-time temperature information; A logic unit is used to determine whether the real-time temperature difference meets the preset asymmetric solidification triggering condition; The controller is used to dynamically adjust the energy distribution state of the energy beam when the asymmetric solidification triggering condition is met, so as to increase the energy invested in the monitoring area with lower temperature in the first monitoring area and the second monitoring area, thereby compensating for the uneven heat dissipation caused by the different material properties between the repair area and the normal area, and thus ensuring that the molten pool achieves symmetrical solidification.

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