High-efficiency excitation head with temperature compensation function

Abstract

This invention relates to the field of pulsed composite magnetic field assisted welding technology, specifically a high-efficiency excitation magnetic head with temperature compensation. It comprises a composite low-leakage magnetic core, a high-temperature excitation coil, a temperature sensor array, a temperature compensation control unit, a high-efficiency heat pipe cooling structure, and a high-temperature resistant anti-spatter protective layer. It integrates a dual-dimensional temperature compensation model based on coil resistance and core permeability, allowing dynamic adjustment of excitation parameters according to real-time three-dimensional temperature field data. Combined with a low-leakage magnetic circuit and efficient heat dissipation design, it achieves a constant magnetic field output. This invention can control magnetic field strength fluctuations within ±1% under operating conditions ranging from -40℃ to 350℃, improving excitation efficiency by over 40%, heat dissipation efficiency by 50%, and significantly extending service life. It is adaptable to various welding conditions, providing core component support for the large-scale industrial application of magnetic field-controlled welding technology.

Description

Technical Field

[0001] This invention relates to the field of magnetic field-assisted welding equipment integration technology, specifically a high-efficiency excitation magnetic head with temperature compensation function. Background Technology

[0002] The excitation head is the core actuator of the pulsed magnetic field welding system. It generates a controllable magnetic field by energizing the excitation coil, thereby regulating the flow state of the weld pool, refining the weld grains, and eliminating welding defects. The stability of its magnetic field output, excitation efficiency, and environmental adaptability directly determine the welding quality and process reliability.

[0003] In the prior art, patent application CN110569681A discloses a magnetic head with temperature compensation function and its temperature compensation method. This solution targets the magnetic head of outdoor card readers, designing a magnetic head structure with temperature compensation. Its core includes a magnetic head body, a shell extending circumferentially along the magnetic head body, and a circuit board. The magnetic head body houses a coil and SMT pins, which abut against the circuit board to form a cavity structure. A temperature controller, a cooling element, and a heating element are housed within the cavity structure. The temperature compensation logic is as follows: the temperature controller detects the temperature signal inside the magnetic head body. When a low-temperature signal is detected, the heating element is triggered to heat up; when a high-temperature signal is detected, the cooling element is triggered to cool down. This controls the internal temperature of the magnetic head to remain within a set range, solving the problem of decreased electrical performance and magnetic reading performance caused by changes in the resistivity of the magnetic head coil in outdoor wide-temperature environments.

[0004] However, the aforementioned existing technical solutions have the following core defects that make them unsuitable for pulsed magnetic field welding conditions: The above-mentioned solutions suffer from severe limitations in adaptability to different operating conditions and are unable to cope with the extreme high-temperature environments of welding. The magnetic heads in these solutions are used in low-power card-reading devices with relatively stable temperature fluctuations, and their operating temperature range only covers -40℃ to +70℃. However, the excitation magnetic heads used for welding are subjected to the combined effects of strong heat radiation from welding arcs exceeding 2000℃ and continuous Joule heating from high-current excitation coils, resulting in a steady-state operating temperature of up to 350℃. The physical temperature control methods of semiconductor cooling and resistance heating in the above-mentioned solutions are completely unable to counteract the continuous strong heat input from welding arcs and cannot solve the problem of drastic temperature rise of the magnetic heads in welding scenarios.

[0005] The temperature compensation mechanism is simplistic and passive, failing to address the core issue of magnetic field attenuation. The aforementioned solution achieves temperature compensation solely through physical temperature control via cooling / heating, which is a passive temperature control method with a slow response time, unable to cope with transient temperature fluctuations during welding. Furthermore, this solution only controls temperature based on changes in coil resistance with temperature, completely neglecting the issues of decreased permeability and increased coercivity of the magnetic core material at high temperatures, leading to reduced magnetic circuit efficiency and increased magnetic leakage. It cannot compensate for the magnetic field strength attenuation caused by the degradation of the magnetic core's magnetic properties, and therefore cannot guarantee the stability of the magnetic field output under welding conditions.

[0006] The magnetic circuit and heat dissipation design are completely mismatched with the welding excitation requirements. The above solution lacks a dedicated low-leakage magnetic circuit design and an efficient heat dissipation structure for the continuous heat generation during welding. It only passively dissipates heat through simple heat dissipation holes and heat sinks, which cannot quickly dissipate the heat continuously accumulated by the magnetic head under welding conditions. This easily leads to coil insulation aging, short circuit burnout, and short service life. At the same time, its magnetic circuit design is crude, with a large amount of leakage flux and low excitation energy utilization. Under the high current excitation conditions of welding, it will form a vicious cycle of "heat generation - increased leakage flux - more severe heat generation".

[0007] The lack of magnetic field precision closed-loop control cannot meet the high precision requirements of the welding process. The above solution only performs open-loop control on the magnetic head temperature, without establishing a correlation model between temperature, excitation parameters, and magnetic field strength. It cannot verify and correct the magnetic field output accuracy in real time, and cannot meet the high precision requirement of the welding process for magnetic field strength fluctuation ≤±1%. This can easily lead to problems such as poor weld formation consistency and insufficient welding process stability.

[0008] Based on this, in response to the industry pain points of magnetic head temperature rise leading to magnetic field strength attenuation, excitation efficiency reduction, and overheating failure under harsh high-temperature welding conditions, there is an urgent need to develop a high-efficiency excitation magnetic head that is adapted to welding conditions, has dual-dimensional temperature compensation, low magnetic leakage, high heat dissipation, and high reliability. Summary of the Invention

[0009] The purpose of this invention is to provide a high-efficiency excitation magnetic head with temperature compensation function to solve the problems mentioned in the background art, such as magnetic head temperature rise leading to magnetic field strength attenuation, excitation efficiency reduction, and overheating failure under high-temperature welding conditions.

[0010] To achieve the above objectives, the present invention provides the following technical solution: A high-efficiency excitation magnetic head with temperature compensation function is used in pulsed composite magnetic field assisted welding equipment. It includes a composite low leakage magnetic core, a high-temperature excitation coil wound on the composite low leakage magnetic core, a temperature sensing array, a temperature compensation control unit, a high-efficiency heat pipe heat dissipation fins, and a high-temperature resistant anti-spatter protective layer. The composite low-leakage magnetic core is composed of DT4C electrical pure iron and nanocrystalline alloy composite laminate, adopts segmented magnetic circuit design, the air gap of the magnetic circuit is controllable, and pre-stores magnetic permeability-temperature characteristic calibration parameters. The high-temperature excitation coil is made of 240 grade polyimide high-temperature resistant enameled flat wire, and thermally conductive insulating sheets are provided between the coil layers. The temperature sensing array includes a coil winding temperature measuring NTC thermistor, a magnetic core body temperature measuring NTC thermistor, and a shell temperature measuring NTC thermistor. The three sensors are respectively deployed on the high-temperature excitation coil winding, the composite low-leakage magnetic core body, and the surface of the magnetic head shell. The sampling frequency is ≥100Hz, which is used to collect the three-dimensional temperature field data of the magnetic head in real time. The temperature compensation control unit is electrically connected to the temperature sensor array and the external excitation power supply, and has a built-in two-dimensional temperature compensation model. It is used to synchronously perform coil resistance temperature compensation and magnetic core permeability temperature compensation based on real-time temperature data, dynamically adjust the excitation power supply output parameters, and control the magnetic head magnetic field strength fluctuation to ≤±1%. The high-efficiency heat pipe heat dissipation fins are equipped with flat micro heat pipes, which are closely attached to the heating areas of the high-temperature excitation coil and the composite low-leakage magnetic core. The high-temperature resistant anti-spatter protective layer is a ceramic anti-spatter coating applied to the outer surface of the magnetic head. The magnetic head as a whole is a compact annular or horseshoe-shaped structure adapted for welding gun installation, and its operating temperature range is -40℃ to 350℃.

[0011] Preferably, the composite low-leakage magnetic core adopts an alternating stacked structure of DT4C electrical pure iron base layer and nanocrystalline alloy sheet, with low-leakage shielding yokes set at the magnetic circuit segments, and the magnetic head leakage coefficient ≤1.05; the permeability-temperature characteristic calibration parameters are obtained by fitting through pre-calibration experiments, and the fitting formula is: ; in, The real-time permeability of the magnetic core at temperature T. Reference temperature Initial permeability at [value] The temperature decay coefficient of magnetic permeability. The Curie temperature is the temperature of the magnetic core material.

[0012] Preferably, the NTC thermistor for coil winding temperature measurement is embedded between the winding layers of the high-temperature excitation coil, the NTC thermistor for core body temperature measurement is embedded inside the yoke of the composite low-leakage magnetic core, and the NTC thermistor for outer shell temperature measurement is embedded inside the arc radiation surface of the magnetic head shell. The temperature measurement accuracy of all three sensors is ±0.5℃. The temperature compensation control unit performs moving average filtering on the three collected temperature signals. The filtering algorithm is as follows: ; in, This is the filtered temperature value from the nth sample. Let be the original sample value of the nith time, and N be the length of the sliding window, which ranges from 5 to 20.

[0013] Preferably, the coil resistance temperature compensation of the temperature compensation control unit is used to calculate the coil resistance increment based on the real-time temperature collected by the NTC thermistor of the coil winding, and dynamically adjust the excitation output current to offset the excitation current attenuation caused by the increase in resistance. The compensation formula is as follows: ; in, Set the excitation current after temperature compensation. Reference temperature The rated excitation current under the condition, This represents the temperature coefficient of resistance of the copper conductor. This is the real-time temperature of the filtered coil.

[0014] Preferably, the temperature compensation control unit's core permeability temperature compensation is used to correct the magnetic circuit gain based on the real-time temperature collected by the NTC thermistor of the core body, fine-tune the duty cycle and peak voltage of the excitation waveform, and compensate for the magnetic field attenuation caused by the decrease in permeability at high temperatures. The magnetic circuit gain correction formula is: ; in, This is the temperature-corrected magnetic circuit gain. The rated magnetic circuit gain at the reference temperature. This represents the permeability corresponding to the real-time temperature of the filtered magnetic core. The initial permeability is at the reference temperature; the compensation response time of the temperature compensation control unit is ≤1ms.

[0015] Preferably, the temperature compensation control unit has a built-in real-time closed-loop verification module that executes a magnetic field strength closed-loop verification algorithm, the algorithm formula of which is: ; in, This is the relative deviation of the magnetic field strength. The real-time magnetic field strength is calculated based on real-time temperature and excitation parameters. The set rated magnetic field strength; when At that time, the temperature compensation control unit triggers secondary compensation adjustment until the magnetic field strength fluctuation is controlled within ±1%.

[0016] Preferably, the flat micro heat pipe supporting the high-efficiency heat pipe radiator fins is a copper powder sintered core heat pipe with a single heat pipe thickness of ≤2 mm. It adopts a U-shaped double-loop symmetric layout and is respectively bonded to the outer sides of the left and right yokes of the composite low-leakage magnetic core and the heat generation core areas on the upper and lower ends of the high-temperature excitation coil. The bonding surface between the heat pipe and the heating body is evenly coated with nano-carbon thermal conductive silicone grease, and the interface contact thermal resistance is ≤0.05 °C / W. The high-efficiency heat pipe radiator fins are aluminum-made dense-tooth fins with anodic oxidation treatment, the fin density is 20 fins per inch, the root of the fins is press-fitted with an interference fit to the condensation end of the flat micro heat pipe, and the fin arrangement direction is consistent with the air flow direction during welding operations.

[0017] Preferably, the high-temperature excitation coil adopts a structure of vertical winding and dense arrangement with 240-grade polyimide high-temperature enameled flat copper wire, the coil slot fill factor ≥78%, and the number of turns is precisely matched with the magnetic path length and air gap parameters of the composite low-leakage magnetic core. A full-width aluminum nitride ceramic-based thermal conductive insulating sheet is laid between adjacent layers of the coil, the breakdown voltage of the insulating sheet ≥5 kV, the thermal conductivity ≥180 W / (m•K), and the layers are positioned and fixed by high-temperature epoxy glue. The leading-out wires at the head and tail of the coil are extended with high-temperature flat wires of the same material, wrapped with polytetrafluoroethylene insulating sleeves, and the welding joints between the roots of the leading-out wires and the coil windings are protected by high-temperature potting. The bonding surface between the outer wall of the coil and the flat micro heat pipe is leveled.

[0018] Preferably, the high-temperature anti-splash protective layer is a gradient composite alumina ceramic-based anti-splash coating, which adopts a double-layer structure of a bottom bonding layer + a surface wear-resistant anti-splash layer as a whole. The bottom layer is a nickel-chromium alloy transition bonding layer, and the surface layer is an alumina-zirconia composite ceramic layer. The total thickness of the coating is 0.3 - 0.8 mm, of which the coating on the radiation surface of the magnetic head facing the welding arc is thickened to 0.6 - 0.8 mm, and the coating thickness on the non-radiation surface is 0.3 - 0.5 mm. The overall temperature resistance grade of the coating ≥1200 °C, the normal temperature adhesion ≥50 MPa, the relative magnetic permeability ≥0.99, and the coating coverage area avoids the area of the high-efficiency heat pipe radiator fins without hindering the circulation of the cooling air flow.

[0019] Preferably, the overall external dimensions of the magnetic head are 85 mm × 60 mm × 45 mm. Standardized card slots and positioning pin holes for adapting to the clamping and installation of the welding torch are provided on the side of the magnetic head body, and the flatness of the installation reference surface ≤0.02 mm. A quick plug interface for the excitation cable and a temperature signal transmission interface are integrally arranged at the tail of the magnetic head. The quick plug interface for the excitation cable adopts an anti-misinsertion keyway design and has a self-threading locking structure, which is adapted to special excitation cables with a temperature resistance of more than 200 °C and is electrically connected to the high-temperature excitation coil. The temperature signal transmission interface is a shielded aviation plug, and the overall protection level of the interface ≥IP65 and is electrically connected to the temperature sensing array and the temperature compensation control unit. The connection area between the temperature compensation control unit inside the magnetic head and the coil and the sensor is vacuum potted with high-temperature epoxy resin, and the temperature resistance grade of the potted area ≥180 °C.

[0020] Compared with the prior art, the beneficial effects of the present invention are: (1) In this invention, a correlation mathematical model of temperature-permeability-excitation parameters is established through a dual-dimensional active temperature compensation mechanism of coil resistance and magnetic core permeability. By collecting three-dimensional temperature field data in real time, the dynamic adjustment of excitation electrical parameters and real-time correction of magnetic circuit gain are completed simultaneously. Combined with a closed-loop verification process of magnetic field strength with millisecond-level response, the magnetic field strength fluctuation of the magnetic head under high-temperature conditions can be controlled within ±1%. This solution starts from the two core influencing factors of magnetic field generation and solves the two major industry problems of excitation current attenuation caused by coil temperature rise and magnetic circuit efficiency reduction caused by magnetic core high-temperature permeability degradation. It overcomes the technical defects of existing technologies, such as single compensation dimension, slow response speed, and inability to adapt to transient temperature changes in the welding process, and fundamentally ensures the stability and consistency of magnetic field output under welding conditions.

[0021] (2) This invention constructs a full-chain thermal management system of "heat reduction-heat dissipation-heat insulation" through the synergistic design of a composite low-leakage magnetic core, a high-efficiency heat pipe heat dissipation structure, and a high-temperature resistant anti-spatter protective layer. This solves the technical problems of low excitation efficiency, vicious cycle of heat generation, and short service life of existing magnetic heads. Among them, the segmented magnetic circuit design of composite lamination of DT4C electrical pure iron and nanocrystalline alloy controls the magnetic head leakage coefficient to within 1.05, which improves the excitation efficiency by more than 40% compared with traditional magnetic cores, and reduces the heat loss in the excitation process from the root of magnetic circuit design; the high-efficiency heat dissipation structure composed of a flat micro heat pipe and a dense toothed heat dissipation fin improves the heat dissipation efficiency by 50% compared with the traditional natural heat dissipation structure, and can quickly dissipate the continuous internal heat of the coil and magnetic core; the high-temperature resistant anti-spatter protective layer composed of a gradient composite alumina ceramic coating can isolate the strong heat radiation of welding arc and welding spatter, while not affecting the magnetic field output. All of the above structures adopt a compact integrated design, which can be adapted to the narrow installation space of the welding torch, overcome the application limitations of limited installation space and harsh working conditions of welding equipment, and greatly improve the working reliability and service life of the magnetic head.

[0022] (3) The technical solution of this invention has strong adaptability to working conditions and technical versatility, covering a variety of mainstream welding process scenarios such as conventional welding of low-carbon steel, multi-layer welding of thick plates of high-strength steel, and precision welding of ultra-thin plates. For different welding currents, ambient temperatures, and excitation requirements, stable magnetic field output can be achieved by adjusting the pre-calibrated permeability parameters and compensation model thresholds, solving the problem that existing magnetic heads have limited application scenarios and cannot be compatible with the needs of multiple welding processes. At the same time, the dual-dimensional temperature compensation method and integrated structural design of this invention do not require significant modifications to the excitation power supply and installation structure of existing welding equipment, resulting in low modification costs and strong adaptability. Its core temperature compensation logic can also be extended to electromagnetic actuators under various high-temperature working conditions, possessing broad technical promotion value. This solution effectively improves the stability and reliability of pulsed composite magnetic field assisted welding processes, providing core component support for the large-scale industrial application of magnetic field-controlled welding technology. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are explained in detail together with the embodiments of the invention, but do not constitute a limitation thereof.

[0024] Figure 1 This is a schematic diagram of the overall structure of the high-efficiency excitation magnetic head with temperature compensation function of the present invention; Figure 2 This is a schematic diagram of the internal magnetic circuit and temperature sensing arrangement of the magnetic head of the present invention; Figure 3 This is a block diagram of the temperature sensing and compensation control system of the present invention; Figure 4 This is a block diagram of the high-efficiency heat dissipation system of the present invention; Figure 5 This is a block diagram of the protection and interface system group of the present invention. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] like Figures 1-5As shown, the high-efficiency excitation magnetic head with temperature compensation function of the present invention is applied to pulsed composite magnetic field assisted welding equipment. It addresses the industry pain points of high-temperature arc radiation, Joule heating of coils causing magnetic head temperature rise, magnetic field strength attenuation, and excitation efficiency reduction during the welding process. Through the integrated design of dual-dimensional temperature compensation, low leakage magnetic circuit design, high-efficiency heat dissipation and high-temperature protection, it achieves a constant output with magnetic field strength fluctuation ≤±1% under operating conditions from -40℃ to 350℃.

[0027] The overall structure of this invention includes eight core components: a high-efficiency heat pipe heat dissipation fin 1, a temperature compensation control unit 2, a coil winding temperature measuring NTC thermistor 3, a magnetic core body temperature measuring NTC thermistor 4, a composite low-leakage magnetic core 5, a high-temperature excitation coil 6, a high-temperature resistant anti-spatter protective layer 7, and a shell temperature measuring NTC thermistor 8. The magnetic head is a compact C-shaped horseshoe structure adapted to the installation space of the welding torch, with overall dimensions of 85mm×60mm×45mm and an operating temperature range of -40℃ to 350℃.

[0028] The composite low-leakage magnetic core 5 serves as the core of the magnetic head's magnetic circuit. It employs a segmented magnetic circuit design with alternating layers of DT4C electrical pure iron and iron-based nanocrystalline alloy sheets. Low-leakage shielded yokes are installed at the circuit segments, ensuring precise control of the air gap and achieving a leakage coefficient ≤1.05. This represents a more than 40% improvement in excitation efficiency compared to traditional pure iron cores. The permeability-temperature characteristics of the composite low-leakage magnetic core 5 were fitted using a pre-calibration experiment, and the fitting formula is: ; in, For temperature The real-time permeability of the magnetic core, expressed in H / m; Reference temperature The initial permeability, expressed in H / m; is the temperature decay coefficient of magnetic permeability, which is dimensionless; Curie temperature of the magnetic core material, in °C; The reference temperature is 25℃.

[0029] During the pre-calibration process, magnetic core permeability data were collected every 25°C within the temperature range of 25°C to 350°C, and obtained by least squares fitting. The value is stored in the storage module of the temperature compensation control unit 2 to provide basic parameters for magnetic permeability temperature compensation.

[0030] The high-temperature excitation coil 6 is the excitation actuator of the magnetic head. It adopts a vertically wound, densely packed structure of 240-grade polyimide high-temperature resistant enameled flat copper wire, wound on the magnetic column of the composite low-leakage magnetic core 5. The coil slot fill factor is ≥78%, and the number of turns is precisely matched with the magnetic circuit length and air gap parameters of the composite low-leakage magnetic core 5. Aluminum nitride ceramic-based thermally conductive insulating sheets are placed across the entire width between adjacent layers of the coil. The breakdown voltage of the insulating sheets is ≥5kV, and the thermal conductivity is ≥180W / (m•K). The layers are fixed by high-temperature resistant epoxy adhesive. The lead wires at the beginning and end of the coil are extended from the same high-temperature resistant flat wire and wrapped with polytetrafluoroethylene insulating sleeves. The welding joint between the root of the lead wire and the coil winding is protected by high-temperature potting. The contact surface between the outer wall of the coil and the flat micro heat pipe is smoothed to reduce contact thermal resistance.

[0031] The temperature sensing array consists of three sensors: a coil winding temperature measuring NTC thermistor 3, a magnetic core body temperature measuring NTC thermistor 4, and a shell temperature measuring NTC thermistor 8. These sensors form a three-dimensional temperature field acquisition system for the magnetic head. The sampling frequency of all three sensors is ≥100Hz, and the temperature measurement accuracy is ±0.5℃.

[0032] The NTC thermistor 3, used for coil winding temperature measurement, is embedded between the winding layers of the high-temperature excitation coil 6 and is tightly fitted to the coil body to collect the operating temperature of the high-temperature excitation coil 6 in real time. This provides the core input for coil resistance temperature compensation; The NTC thermistor 4, used for core body temperature measurement, is embedded inside the yoke of the composite low-leakage magnetic core 5, and is in close contact with the core body to collect the operating temperature of the composite low-leakage magnetic core 5 in real time. This provides the core input for temperature compensation of magnetic core permeability; The NTC thermistor 8, which measures the temperature of the outer shell, is embedded inside the arc radiation surface of the high-temperature resistant and splash-proof protective layer 7, and collects the temperature of the magnetic head shell after being irradiated by the welding arc in real time. This provides an environmental temperature correction reference for the temperature compensation model.

[0033] The temperature compensation control unit 2 is the core of the magnetic head control, electrically connected to the temperature sensor array and the external excitation power supply. It incorporates a two-dimensional temperature compensation model and a real-time closed-loop verification module, with a compensation response time ≤1ms. The workflow of the temperature compensation control unit 2 consists of four steps: temperature signal filtering, two-dimensional compensation calculation, excitation output adjustment, and closed-loop verification. (1) Temperature signal filtering processing The temperature compensation control unit 2 performs moving average filtering on the raw temperature signals collected by the three sensors. The filtering algorithm is as follows:

[0034] in, For the first The filtered temperature value after the sampling, in °C; For the first The original sampling temperature value, in °C; The length of the sliding window ranges from 5 to 20. In this embodiment... Take 10.

[0035] (2) Two-dimensional temperature compensation calculation Coil resistance temperature compensation: based on the real-time temperature of the filtered coil. The coil resistance increment is calculated, and the excitation setting current is dynamically increased to compensate for the current attenuation caused by the increase in copper coil resistance with temperature. The compensation formula is as follows: ; in, The excitation setting current after temperature compensation, in A; Reference temperature The rated excitation current, in amperes (A); The temperature coefficient of resistance of copper wire is denoted as , and its value is . ; This is the real-time temperature of the filtered coil, in °C. The reference temperature is 25℃.

[0036] Calculation example: when the reference temperature At that time, the rated excitation current Real-time temperature of the coil during welding Substituting into the formula, we get: ; After temperature compensation, the excitation setting current is increased to 16.88A to offset the current attenuation caused by the increase in coil resistance.

[0037] Core permeability temperature compensation: based on the real-time temperature of the filtered core. The permeability at the corresponding temperature can be obtained by looking up the table. To correct the magnetic circuit gain, fine-tune the duty cycle and peak voltage of the excitation waveform, and compensate for the magnetic field attenuation caused by the decrease in permeability at high temperatures, the magnetic circuit gain correction formula is as follows: ; in, This is the temperature-corrected magnetic circuit gain, which is dimensionless. Reference temperature The rated magnetic circuit gain at the specified value is dimensionless. Reference temperature The initial permeability, expressed in H / m; The value represents the permeability of the magnetic core at the real-time temperature after filtering, in H / m.

[0038] (3) Real-time closed-loop verification The temperature compensation control unit 2 has a built-in real-time closed-loop verification module that executes a magnetic field strength closed-loop verification algorithm. The algorithm formula is as follows: ; in, The relative deviation of magnetic field strength is expressed in % (%). The real-time magnetic field strength is calculated based on real-time temperature and excitation parameters, and the unit is mT; The set rated magnetic field strength is expressed in mT.

[0039] when At this time, the temperature compensation control unit 2 triggers secondary compensation adjustment until the magnetic field strength fluctuation is controlled within ±1%, ensuring the stability of the magnetic field output.

[0040] The high-efficiency heat pipe fin 1 is equipped with a flat micro heat pipe, which is a copper powder sintered core heat pipe with a single heat pipe thickness ≤2mm. It adopts a U-shaped double-loop symmetrical layout and is respectively attached to the outer side of the left and right magnetic yokes of the composite low leakage magnetic core 5 and the upper and lower end faces of the high-temperature excitation coil 6 heating core area. The contact surface between the heat pipe and the heating element is uniformly coated with nano carbon thermal conductive silicone grease, and the interface contact thermal resistance is ≤0.05℃ / W. The high-efficiency heat pipe fin 1 is anodized aluminum fine tooth fin with a fin density of 20 fins / inch. The fin root is press-fitted to the condensation end of the flat micro heat pipe. The fin arrangement direction is consistent with the airflow direction during welding. Compared with the traditional natural heat dissipation structure, the heat dissipation efficiency is improved by 50% and the steady-state temperature rise is reduced by more than 40℃.

[0041] The high-temperature resistant anti-spatter protective layer 7 is a gradient composite alumina ceramic-based anti-spatter coating applied to the outer surface of the magnetic head. It employs a double-layer structure: a bottom adhesive layer and a top wear-resistant anti-spatter layer. The bottom layer is a nickel-chromium alloy transition adhesive layer, and the top layer is an alumina-zirconia composite ceramic layer. The total coating thickness is 0.3-0.8 mm, with the coating on the radiating surface of the magnetic head facing the welding arc thickened to 0.6-0.8 mm, and the coating thickness on the non-radiating surface being 0.3-0.5 mm. The overall temperature resistance of the coating is ≥1200℃, its adhesion at room temperature is ≥50 MPa, and its relative permeability is ≥0.99. The coating coverage avoids the area of ​​the high-efficiency heat pipe fins 1, does not obstruct the airflow of heat dissipation, effectively isolates the heat radiation of the welding arc, prevents welding spatter adhesion, and does not shield the magnetic field output.

[0042] Example 1: General-purpose excitation magnetic head for low-carbon steel welding The excitation head in this embodiment is used in the MAG welding scenario of Q235 low carbon steel flat plate butt joint. The welding current is 180A~220A, the arc temperature is about 2000℃, and the maximum working temperature of the head is 250℃, which is the most commonly used general working condition in the welding field.

[0043] Core structural parameters Composite low-leakage magnetic core 5: Employs alternating layers of 0.5mm thick DT4C electrical pure iron base and 0.02mm thick iron-based nanocrystalline alloy sheets, with a stacking factor of 0.85, a magnetic circuit air gap of 0.8mm, a yoke width of 12mm, and an initial permeability of [missing value] at a reference temperature of 25℃. Curie temperature The temperature decay coefficient of magnetic permeability was obtained by pre-calibration fitting. The leakage coefficient is 1.04.

[0044] High-temperature excitation coil 6: It adopts 240-grade polyimide enameled flat copper wire with a specification of 1.2mm×0.5mm, vertical winding structure, a total of 120 turns, a slot fill factor of 79%, and 0.2mm thick aluminum nitride thermally conductive insulating sheet between layers.

[0045] Temperature sensor array: 3-channel NTC thermistor, B value 3950K, temperature measurement range -40℃ to 350℃, sampling frequency 100Hz, sliding window length .

[0046] High-efficiency heat pipe fin 1: Equipped with 2 U-shaped flat micro heat pipes, 1.8mm thick, 75mm long, aluminum heat sink fin density 20 fins / inch, total heat dissipation area 0.12㎡.

[0047] High-temperature resistant splash-proof protective layer 7: Total thickness 0.5mm, arc radiation surface thickness 0.7mm, temperature resistance 1200℃, relative magnetic permeability 0.995.

[0048] Temperature compensation control unit 2: Rated excitation voltage 24VDC, rated excitation current at a reference temperature of 25℃ Rated magnetic field strength The compensation response time is 0.8ms.

[0049] Temperature compensation calculation process: During the welding process, the temperature sensor array collects and filters the temperature; coil temperature. Core temperature Casing temperature .

[0050] 1. Coil resistance temperature compensation calculation: Substitute into the compensation formula, copper resistance temperature coefficient reference temperature : ; The temperature compensation control unit 2 increases the excitation setting current to 12.87A to offset the effect of increased coil resistance.

[0051] 2. Temperature compensation calculation of magnetic core permeability: Substituting into the permeability fitting formula, calculate the real-time magnetic core permeability at 165℃: ; Substituting this into the magnetic circuit gain correction formula, the rated magnetic circuit gain... : ; The temperature compensation control unit 2 increases the excitation waveform duty cycle from 50% to 62% and the peak voltage from 24V to 29.7V to compensate for the magnetic field attenuation caused by the decrease in magnetic permeability.

[0052] 3. Closed-loop verification: The real-time magnetic field strength is calculated after compensation. Substitute into the closed-loop verification formula: ; It meets the requirements for magnetic field strength fluctuations and does not require secondary compensation.

[0053] Actual test results In this embodiment, under continuous welding conditions for 8 hours, the magnetic head has a maximum steady-state temperature of 225°C, a magnetic field strength fluctuation range of ±0.5%, uniform weld formation, no porosity or crack defects, no overheating or insulation aging, and a service life of over 8500 hours.

[0054] Example 2: High-stability excitation magnetic head for welding high-strength steel thick plates The excitation head in this embodiment is applied to multi-layer, multi-pass submerged arc welding of 30mm thick Q690 high-strength steel plates. The welding current is 500A~600A, the arc temperature is about 2800℃, and the maximum operating temperature of the head is 350℃. It has extremely high requirements for magnetic field stability, high temperature resistance, and heat dissipation.

[0055] Composite low-leakage magnetic core 5: Employs alternating layers of 0.3mm thick DT4C electrical pure iron base and 0.02mm thick iron-based nanocrystalline alloy sheets, with a stacking factor of 0.88, a magnetic circuit air gap of 1.2mm, a yoke width of 18mm, and an initial permeability at a reference temperature of 25℃. Curie temperature The temperature decay coefficient of magnetic permeability was obtained by pre-calibration fitting. The leakage coefficient is 1.03.

[0056] High-temperature excitation coil 6: It adopts 240-grade polyimide enameled flat copper wire with a specification of 2.0mm×0.8mm, vertical winding structure, a total of 200 turns, a slot fill factor of 82%, and 0.3mm thick aluminum nitride thermally conductive insulating sheet between layers. The outer wall of the coil is nickel-plated for thermal conductivity.

[0057] Temperature sensor array: 3-channel NTC thermistor, B value 3977K, temperature measurement range -40℃~400℃, sampling frequency 200Hz, sliding window length .

[0058] High-efficiency heat pipe fin 1: Equipped with 4 U-shaped flat micro heat pipes, 1.5mm thick, 80mm long, aluminum heat dissipation fin density of 22 fins / inch, total heat dissipation area of ​​0.2㎡, and equipped with a micro axial flow fan for auxiliary air cooling.

[0059] High-temperature resistant splash-proof protective layer 7: Total thickness 0.8mm, arc radiation surface thickness 0.8mm, temperature resistance 1300℃, bottom layer with 0.1mm thick mica heat insulation layer, relative magnetic permeability 0.992.

[0060] Temperature compensation control unit 2: Rated excitation voltage 48VDC, rated excitation current at a reference temperature of 25℃ Rated magnetic field strength The compensation response time is 0.5ms, and it has a built-in over-temperature protection module.

[0061] Temperature compensation calculation process During multi-layer welding, the temperature sensor array collects filtered temperature data: coil temperature. Core temperature Casing temperature .

[0062] 1. Coil resistance temperature compensation calculation: Substitute into the compensation formula, , : ; The temperature compensation control unit 2 increases the excitation setting current to 32.39A to counteract the effect of increased coil resistance.

[0063] 2. Temperature compensation calculation of magnetic core permeability: Substitute into the permeability fitting formula to calculate the real-time magnetic core permeability at 300℃: ; Substituting this into the magnetic circuit gain correction formula, the rated magnetic circuit gain... : ; The temperature compensation control unit 2 increases the excitation waveform duty cycle from 60% to 94% and the peak voltage from 48V to 75.4V to compensate for the magnetic field attenuation caused by the decrease in magnetic permeability.

[0064] 3. Closed-loop verification: The real-time magnetic field strength is calculated after compensation. Substitute into the closed-loop verification formula: It meets the requirements for magnetic field strength fluctuations and does not require secondary compensation.

[0065] Actual test results In this embodiment, under continuous multi-layer welding for 12 hours, the magnetic head reaches a maximum steady-state temperature of 330°C, with a magnetic field strength fluctuation range of ±0.6%. The weld grain refinement effect is significant, the low-temperature impact energy is increased by more than 45%, there are no welding cold crack defects, the magnetic head insulation performance is stable, there is no overheating and burn-out phenomenon, and the service life can reach more than 9000 hours.

[0066] Example 3: Low-power excitation magnetic head for precision welding of ultra-thin plates The excitation head in this embodiment is used in the TIG precision welding of 0.2mm thick 304 stainless steel ultrathin plates. The welding current is 5A~10A, the arc temperature is about 1500℃, and the maximum operating temperature of the head is 180℃. The requirements for the head to be lightweight, low leakage flux, low power consumption, and magnetic field control accuracy are extremely high.

[0067] Composite low-leakage magnetic core 5: Employs alternating layers of 0.2mm thick DT4C electrical pure iron base and 0.01mm thick iron-based nanocrystalline alloy sheets, with a stacking factor of 0.9, a magnetic circuit air gap of 0.3mm, a yoke width of 8mm, and an initial permeability at a reference temperature of 25℃. Curie temperature The temperature decay coefficient of magnetic permeability was obtained by pre-calibration fitting. With a magnetic leakage coefficient of 1.02, the magnetic circuit is fully enclosed by a permalloy shielding layer, reducing electromagnetic interference to the outside world.

[0068] High-temperature excitation coil 6: It adopts 240-grade polyimide enameled flat copper wire with a specification of 0.5mm×0.2mm, vertical winding structure, a total of 80 turns, a slot fill factor of 78%, and 0.1mm thick aluminum nitride thermally conductive insulating sheet between layers. The coil as a whole is lightweight.

[0069] Temperature sensing array: 3-channel miniature NTC thermistor, B value 3950K, temperature measurement range -40℃ to 200℃, sampling frequency 100Hz, sliding window length .

[0070] High-efficiency heat pipe fin 1: Equipped with one U-shaped flat micro heat pipe, 1.2mm thick and 60mm long, with an aluminum heat dissipation fin density of 18 fins / inch and a total heat dissipation area of ​​0.06㎡, natural heat dissipation without auxiliary air cooling.

[0071] High-temperature resistant splash-proof protective layer 7: Total thickness 0.3mm, arc radiation surface thickness 0.4mm, temperature resistance 1200℃, relative magnetic permeability 0.998, no excess coating, controlling overall weight.

[0072] Temperature compensation control unit 2: Rated excitation voltage 12VDC, rated excitation current at a reference temperature of 25℃ Rated magnetic field strength The compensation response time is 1ms, and the magnetic field control accuracy is ±0.2mT.

[0073] Temperature compensation calculation process During precision welding, the temperature sensor array collects filtered temperature data: coil temperature. Core temperature Casing temperature .

[0074] 1. Coil resistance temperature compensation calculation: Substitute into the compensation formula, , : ; The temperature compensation control unit 2 increases the excitation setting current to 4.47A to counteract the effect of increased coil resistance.

[0075] 2. Temperature compensation calculation of magnetic core permeability: Substituting into the permeability fitting formula, calculate the real-time magnetic core permeability at 135℃: ; Substituting this into the magnetic circuit gain correction formula, the rated magnetic circuit gain... : ; The temperature compensation control unit 2 increases the excitation waveform duty cycle from 40% to 47.5% and the peak voltage from 12V to 14.24V to compensate for the magnetic field attenuation caused by the decrease in magnetic permeability.

[0076] 3. Closed-loop verification: The real-time magnetic field strength is calculated after compensation. Substitute into the closed-loop verification formula: ; It meets the requirements for magnetic field strength fluctuations and does not require secondary compensation.

[0077] Actual test results In this embodiment, the magnetic head reaches a maximum steady-state temperature of 165°C and a magnetic field strength fluctuation range of ±0.6% under continuous precision welding conditions of 4 hours. The ultra-thin plate weld is smooth and beautiful, without burn-through or deformation defects. The overall weight of the magnetic head is only 120g, and the power consumption is reduced by 35% compared with traditional magnetic heads. It is perfectly adapted to the installation requirements of automated welding guns for precision welding.

[0078] This invention addresses the core technical challenge of magnetic field strength attenuation in excitation heads under high-temperature welding conditions. Breaking away from the single-compensation approach of passive physical temperature control in existing magnetic head systems, it pioneers a dual-dimensional active temperature compensation mechanism based on coil resistance and core permeability. A correlation mathematical model between temperature, permeability, and excitation parameters is established. Through real-time acquisition of three-dimensional temperature field data, dynamic adjustment of excitation electrical parameters and real-time correction of magnetic circuit gain are simultaneously achieved. Combined with a millisecond-level closed-loop verification process for magnetic field strength, the magnetic field strength fluctuation of the magnetic head under high-temperature conditions can be controlled within ±1%. This solution addresses the two core influencing factors of magnetic field generation, simultaneously solving two major industry challenges: excitation current attenuation due to coil temperature rise and magnetic circuit efficiency reduction caused by high-temperature permeability degradation of the core. It overcomes the technical shortcomings of existing technologies, such as single-dimensional compensation, slow response speed, and inability to adapt to transient temperature changes during welding, fundamentally ensuring the stability and consistency of magnetic field output under welding conditions.

[0079] This invention constructs a complete thermal management system encompassing heat reduction, heat dissipation, and insulation through the synergistic design of a composite low-leakage magnetic core, a high-efficiency heat pipe cooling structure, and a high-temperature resistant anti-spatter protective layer. This solves the technical problems of low excitation efficiency, vicious cycle of heat generation, and short service life of existing magnetic heads. Specifically, the segmented magnetic circuit design, composed of DT4C electrical pure iron and nanocrystalline alloy composite laminations, controls the magnetic head leakage coefficient to below 1.05, improving excitation efficiency by more than 40% compared to traditional magnetic cores, thus reducing heat loss during excitation from the root of the magnetic circuit design. The high-efficiency heat dissipation structure, composed of a fitted flat micro heat pipe and densely toothed heat dissipation fins, improves heat dissipation efficiency by 50% compared to traditional natural heat dissipation structures, quickly dissipating the continuous internal heat of the coil and magnetic core. The high-temperature resistant anti-spatter protective layer, composed of a gradient composite alumina ceramic coating, isolates the strong heat radiation of the welding arc and welding spatter without affecting the magnetic field output. All of the above structures adopt a compact integrated design, adaptable to the limited installation space of welding torches, overcoming the application limitations of limited installation space and harsh working conditions for welding equipment, and significantly improving the working reliability and service life of the magnetic head.

[0080] The technical solution of this invention possesses strong adaptability to various operating conditions and technical versatility, covering multiple mainstream welding process scenarios such as conventional welding of low-carbon steel, multi-layer welding of thick plates of high-strength steel, and precision welding of ultra-thin plates. For different welding currents, ambient temperatures, and excitation requirements, stable magnetic field output can be achieved by adjusting pre-calibrated permeability parameters and compensation model thresholds, solving the problem of existing magnetic heads having limited application scenarios and incompatibility with multiple welding process requirements. Furthermore, the dual-dimensional temperature compensation method and integrated structural design of this invention do not require significant modifications to the excitation power supply and installation structure of existing welding equipment, resulting in low modification costs and strong adaptability. Its core temperature compensation logic can also be extended to electromagnetic actuators under various high-temperature operating conditions, possessing broad technical promotion value. This solution effectively improves the stability and reliability of pulsed composite magnetic field-assisted welding processes, providing core component support for the large-scale industrial application of magnetic field-controlled welding technology.

[0081] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency excitation magnetic head with temperature compensation function, applied to pulsed composite magnetic field assisted welding equipment, comprising a composite low-leakage magnetic core (5) and a high-temperature excitation coil (6) wound on the composite low-leakage magnetic core (5), characterized in that, It also includes a temperature sensing array, a temperature compensation control unit (2), a high-efficiency heat pipe heat dissipation fin (1), and a high-temperature resistant splash-proof protective layer (7). The composite low leakage magnetic core (5) is composed of DT4C electrical pure iron and nanocrystalline alloy composite laminate, adopts segmented magnetic circuit design, the air gap of the magnetic circuit is controllable, and has pre-stored magnetic permeability-temperature characteristic calibration parameters. The high-temperature excitation coil (6) is made of 240 grade polyimide high-temperature resistant enameled flat wire, and thermally conductive insulating sheets are provided between the coil layers; The temperature sensing array includes a coil winding temperature measuring NTC thermistor (3), a magnetic core body temperature measuring NTC thermistor (4), and a shell temperature measuring NTC thermistor (8). The three sensors are respectively arranged on the high temperature excitation coil (6) winding, the composite low leakage magnetic core (5) body, and the magnetic head shell surface, with a sampling frequency ≥100Hz, for real-time acquisition of three-dimensional temperature field data of the magnetic head. The temperature compensation control unit (2) is electrically connected to the temperature sensing array and the external excitation power supply respectively. It has a built-in dual-dimensional temperature compensation model, which is used to synchronously perform coil resistance temperature compensation and magnetic core permeability temperature compensation according to real-time temperature data, dynamically adjust the excitation power supply output parameters, and control the magnetic head magnetic field strength fluctuation ≤±1%. The high-efficiency heat pipe heat dissipation fins (1) are equipped with flat micro heat pipes, and the flat micro heat pipes are closely attached to the heating areas of the high-temperature excitation coil (6) and the composite low leakage magnetic core (5). The high-temperature resistant anti-spatter protective layer (7) is a ceramic anti-spatter coating applied to the outer surface of the magnetic head. The magnetic head is a compact ring or horseshoe-shaped structure adapted to the installation of welding guns, and its working temperature range is -40℃ to 350℃.

2. The high-efficiency excitation head with temperature compensation function according to claim 1, characterized in that, The composite low-leakage magnetic core (5) adopts an alternating stacked structure of DT4C electrical pure iron base layer and nanocrystalline alloy sheet, with low-leakage shielding yokes set at the magnetic circuit segments, and the magnetic head leakage coefficient ≤1.05; the permeability-temperature characteristic calibration parameters are obtained by fitting through pre-calibration experiments, and the fitting formula is: ； in, The real-time permeability of the magnetic core at temperature T. Reference temperature Initial permeability at [value] The temperature decay coefficient of magnetic permeability. The Curie temperature is the temperature of the magnetic core material.

3. The high-efficiency excitation head with temperature compensation function according to claim 1, characterized in that, The coil winding temperature measuring NTC thermistor (3) is embedded between the winding layers of the high-temperature excitation coil (6), the core body temperature measuring NTC thermistor (4) is embedded inside the yoke of the composite low-leakage magnetic core (5), and the outer shell temperature measuring NTC thermistor (8) is embedded inside the arc radiation surface of the magnetic head shell. The temperature measurement accuracy of the three sensors is ±0.5℃. The temperature compensation control unit (2) performs moving average filtering on the three collected temperature signals. The filtering algorithm is as follows: ； in, This is the filtered temperature value from the nth sample. Let be the original sample value of the nith time, and N be the length of the sliding window, which ranges from 5 to 20.

4. The high-efficiency excitation head with temperature compensation function according to claim 1, characterized in that, The temperature compensation control unit (2) performs coil resistance temperature compensation to calculate the coil resistance increment based on the real-time temperature collected by the NTC thermistor (3) of the coil winding temperature measurement unit, and dynamically adjusts the excitation output current to offset the excitation current attenuation caused by the increase in resistance. The compensation formula is as follows: ； in, Set the excitation current after temperature compensation. Reference temperature The rated excitation current under the condition, This represents the temperature coefficient of resistance of the copper conductor. This is the real-time temperature of the filtered coil.

5. The high-efficiency excitation head with temperature compensation function according to claim 1, characterized in that, The temperature compensation control unit (2) for magnetic core permeability temperature compensation is used to correct the magnetic circuit gain based on the real-time temperature collected by the NTC thermistor (4) of the magnetic core body, fine-tune the duty cycle and peak voltage of the excitation waveform, and compensate for the magnetic field attenuation caused by the decrease in permeability at high temperature. The magnetic circuit gain correction formula is: ； in, This is the temperature-corrected magnetic circuit gain. The rated magnetic circuit gain at the reference temperature. This represents the permeability corresponding to the real-time temperature of the filtered magnetic core. The initial permeability is at the reference temperature; the compensation response time of the temperature compensation control unit (2) is ≤1ms.

6. The high-efficiency excitation head with temperature compensation function according to claim 1, characterized in that, The temperature compensation control unit (2) has a built-in real-time closed-loop verification module that executes a magnetic field strength closed-loop verification algorithm. The algorithm formula is as follows: ； in, This is the relative deviation of the magnetic field strength. The real-time magnetic field strength is calculated based on real-time temperature and excitation parameters. The set rated magnetic field strength; when At that time, the temperature compensation control unit (2) triggers secondary compensation adjustment until the magnetic field strength fluctuation is controlled within ±1%.

7. The high-efficiency excitation head with temperature compensation function according to claim 1, characterized in that, The flat micro heat pipes that are matched with the high-efficiency heat pipe heat dissipation fins (1) are copper powder sintered core heat pipes with a single heat pipe thickness ≤2mm. They adopt a U-shaped double-loop symmetrical layout and are respectively attached to the outer side of the left and right magnetic yokes of the composite low leakage magnetic core (5) and the upper and lower end heating core areas of the high-temperature excitation coil (6). The contact surfaces of the heat pipes and the heating elements are uniformly coated with nano carbon thermal conductive silicone grease, and the interface contact thermal resistance is ≤0.05℃ / W. The high-efficiency heat pipe heat dissipation fins (1) are aluminum fine-tooth fins with anodized treatment and a fin density of 20 fins / inch. The fin roots are press-fitted with the condensation end of the flat micro heat pipe, and the fin arrangement direction is consistent with the airflow direction during welding.

8. The high-efficiency excitation head with temperature compensation function according to claim 1, characterized in that, The high-temperature excitation coil (6) adopts a 240-grade polyimide high-temperature resistant enameled flat copper wire vertical winding close-packed structure, with a coil slot fill factor ≥78%, and the number of turns is precisely matched with the magnetic circuit length and air gap parameters of the composite low leakage magnetic core (5); aluminum nitride ceramic-based thermally conductive insulating sheets are installed on the full width between adjacent coil layers, with a breakdown voltage ≥5kV and a thermal conductivity ≥180W / (m•K), and the layers are fixed by high-temperature resistant epoxy glue; the coil leads are extended with the same material high-temperature resistant flat wire, wrapped with polytetrafluoroethylene insulating sleeve, and the welded joint between the lead root and the coil winding is protected by high-temperature potting, and the contact surface between the outer wall of the coil and the flat micro heat pipe is flattened.

9. The high-efficiency excitation head with temperature compensation function according to claim 1, characterized in that, The high-temperature resistant anti-splash protective layer (7) is a gradient composite alumina ceramic-based anti-splash coating. The whole adopts a double-layer structure of bottom adhesive layer + top wear-resistant anti-splash layer. The bottom layer is a nickel-chromium alloy transition adhesive layer, and the top layer is an alumina-zirconia composite ceramic layer. The total thickness of the coating is 0.3-0.8mm, of which the coating on the radiating surface facing the welding arc of the magnetic head is thickened to 0.6-0.8mm, and the coating on the non-radiating surface is 0.3-0.5mm thick. The overall temperature resistance of the coating is ≥1200℃, the adhesion at room temperature is ≥50MPa, the relative permeability is ≥0.99, and the coating coverage avoids the area of ​​the high-efficiency heat pipe heat dissipation fins (1) and does not obstruct the flow of heat dissipation airflow.

10. The high-efficiency excitation head with temperature compensation function according to claim 1, characterized in that, The overall dimensions of the magnetic head are 85mm×60mm×45mm. The side of the magnetic head body is provided with a standardized slot and positioning pin hole for welding gun clamping and installation. The flatness of the mounting reference surface is ≤0.02mm. The tail of the magnetic head is integrated with an excitation cable quick-connect interface and a temperature signal transmission interface. The excitation cable quick-connect interface adopts an anti-misinsertion key design and has a built-in threaded locking structure. It is compatible with special excitation cables with a temperature resistance of 200℃ or higher and is electrically connected to the high-temperature excitation coil (6). The temperature signal transmission interface is a shielded aviation plug with an overall protection level of ≥IP65. It is electrically connected to the temperature sensing array and the temperature compensation control unit (2). The connection area between the temperature compensation control unit (2) inside the magnetic head and the coil and sensor is vacuum potted with high-temperature resistant epoxy resin. The temperature resistance level of the potted area is ≥180℃.

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