Broadband magnetic characteristic measuring device and system under temperature-biaxial stress cooperative loading

Abstract

The invention discloses a broadband magnetic characteristic measuring device and system under temperature-biaxial stress cooperative loading. According to the measuring device, normal pressure is applied to the upper side of a rectangular sample through a jack with a force sensor and a display screen, horizontal pulling and pressing stress is applied through a motor with a force sensor and a hand wheel sliding table, the temperature is adjusted through a heater and a cast aluminum heating plate, and the measuring device is controlled through a measuring circuit of a measuring system. Multi-axis stress and temperature working condition simulation is achieved, magnetic characteristic data better fitting the actual working condition of the electrical equipment is obtained, and then optimization design of the electrical equipment is guided more accurately. The phenolic resin framework on the upper layer of the measuring device adopts a cover deep hole type structure, so that the H sensor of the measuring device is more convenient to replace and inspect, and in order to ensure the measuring accuracy, a double-layer H coil is used, so that the problem of inaccurate measurement possibly caused by the fact that a single-layer H coil is not tightly attached to a rectangular sample is solved.

Description

Technical Field

[0001] The invention relates to the technical field of soft magnetic material performance measurement, in particular to a broadband magnetic property measurement device and system under temperature-biaxial stress coordinated loading. Background Art

[0002] Silicon steel, amorphous alloys, nanocrystalline and other soft magnetic materials are widely used in various high-power electrical equipment such as power transformers, generators, motors, etc. They play an irreplaceable role in the power industry and are of great significance to national development. However, electrical equipment will be affected by operating temperature and bolt preload in actual operation, resulting in reduced working efficiency and even accidents such as burning. Accurately measuring the magnetic properties of soft magnetic materials used in transformers and other equipment under multiple working conditions has important guiding significance for the optimal design of electrical equipment.

[0003] The magnetic property measurement of soft magnetic materials can be divided into one-dimensional, two-dimensional and three-dimensional magnetic property measurement according to the excitation conditions. One-dimensional magnetic property measurement refers to the measurement of the magnetic properties of magnetic materials under the excitation of a single-direction magnetic field. At present, the situation of single-direction magnetic field excitation is still very common in electrical equipment. Most of the soft magnetic materials operate under multiple working conditions. Therefore, it is of great significance to simulate and test the one-dimensional magnetic properties of soft magnetic materials under multiple working conditions.

[0004] The one-dimensional magnetic property measurement mainly relies on the law of electromagnetic induction and Ampere's loop law. The methods include Epstein square ring method, ring sample method and single-piece measurement method. At present, the single-piece measurement method is the simplest and most widely used in sample preparation. The literature "S. Huang, C. Stefano Ragusa, W. Xu, L. Solimene and S. Wang, "Measurement of the Vector Magnetic Property of Electrical Steel Sheet UnderTriaxial Stress" in IEEE Transactions on Instrumentation and Measurement, vol. 73, pp. 1-13, 2024, Art no. 6008313, doi: 10.1109 / TIM.2024.3442856." uses a handwheel slide to apply normal stress to simulate the lamination condition, but the normal stress that can be applied by this method is limited. Using human power to rotate the handwheel slide cannot produce a large enough compressive stress on the rectangular sample, and cannot fully reflect the actual engineering situation. In addition, the device does not have a temperature module and uses a single yoke. Although the single yoke will not exert pressure on the rectangular sample to deteriorate its magnetic properties, it will cause serious eddy current problems. The patent "Zhang Changgeng, Li Xizheng, Wang Li, etc. A magnetic property test device for electrical steel sheets considering the stress in the direction of the stacking [P]. Tianjin: CN202311729009.1, 2024-03-15." uses a jack to apply normal stress, ensuring the range of normal stress, but it only involves uniaxial stress, without horizontal tensile stress and compressive stress, and cannot simulate the actual working environment, and does not consider temperature factors.

[0005] During the actual operation of electrical equipment such as transformer cores and motors, they all work under multiple working conditions. The magnetic properties will deteriorate with changes in temperature and stress loading, resulting in reduced working efficiency. For example, the transformer core may be subjected to mechanical stress due to being fastened by clamps or bolts during installation or operation, and the core loss of the rotor and stator in the motor and the copper loss of the winding will increase the operating temperature of the equipment to more than 100°C. Existing test equipment cannot provide accurate measurement of the actual magnetic properties of soft magnetic materials under multiple working conditions. Summary of the invention

[0006] In order to solve the deficiencies of the prior art, the present invention provides a broadband magnetic property measurement device and system under temperature-biaxial stress coordinated loading. The measurement device and system can accurately obtain the actual magnetic properties of soft magnetic materials under multiple working conditions, and play a guiding role in the structural optimization design of transformer cores, motors, etc.

[0007] The technical solution of the present invention to solve the technical problem is: to provide a broadband magnetic property measurement device under temperature-biaxial stress coordinated loading, characterized in that the device includes a top plate, a side plate with holes, a longitudinal stress application module, a side plate without holes, an excitation module, a temperature loading device, a sensor module, a side plate of a base, a horizontal stress application device on the side of a handwheel slide, a horizontal stress application device on the side of a motor, and a bottom plate; The measuring device has two base side plates, which are parallel, opposite and centrally fixed on the front and rear sides of the upper surface of the bottom plate, and the aluminum alloy pad is horizontally fixed on the top between the two base side plates; the side plate with holes and the side plate without holes have the same size, and the two are parallel, opposite and centrally fixed on the front and rear sides of the top surface of the aluminum alloy pad, and because the top plate is horizontally fixed on the upper part between the side plate with holes and the side plate without holes, it is fixedly connected with the side plate with holes and the side plate without holes by horizontal screws; the lower part of the side plate with holes is provided with a longitudinal stress loading hole that is opposite to the side plate without holes; The temperature loading device comprises a phenolic resin heat insulation board, a cast aluminum heating plate, an aluminum alloy pad and a temperature loading device terminal; an inner groove is arranged in the center of the upper surface of the aluminum alloy pad, and a wire through hole is arranged at the bottom of the inner groove to penetrate the bottom surface of the aluminum alloy pad; a positioning groove is symmetrically arranged in the middle position of the left and right sides to penetrate the upper and lower directions; the outer size of the phenolic resin heat insulation board matches the size of the inner groove on the aluminum alloy pad, and a heating groove is arranged in the center of the upper surface; the phenolic resin heat insulation board is arranged in the inner groove on the aluminum alloy pad, and its A through hole is provided at the bottom of the heating slot and at a position directly opposite to the wire through hole of the aluminum alloy pad; the cast aluminum heating plate is arranged in the heating slot of the phenolic resin insulation plate; two heating wires arranged in reverse parallel are buried inside the cast aluminum heating plate, and the power connection ends of the two heating wires are respectively wound on two temperature loading device terminals, and the two temperature loading device terminals are arranged in the wire through hole of the aluminum alloy pad, and the outer sides of the two temperature loading device terminals are connected to the external measurement circuit, and the external measurement circuit provides working current for the heating wire, thereby heating the rectangular sample; The sensor module includes an upper winding skeleton, a skeleton cover, a lower winding skeleton, an H coil, an H coil pad, and an H coil partition, wherein the H coil includes a PCB board and an H coil copper wire; the upper winding skeleton, the skeleton cover, and the lower winding skeleton constitute a winding skeleton, which is arranged in the middle position on the upper surface of the aluminum alloy pad along the left-right direction, and its setting direction is parallel to the perforated side plate, its left-right length is equal to the left-right length of the aluminum alloy pad, and its front-to-back width is not greater than the front-to-back width of the inner groove opening of the cast aluminum heating plate; the upper winding skeleton and the lower winding skeleton The length and width are the same, and a two-step notch is set in the middle of the upper winding frame, of which the lower one is a rectangular H sensor group slot, and the upper one is a notch matching the outer dimensions of the frame cover; the H sensor group slot is used to set the sensor group, and an H coil outlet hole is set on the top of the front side wall of the H sensor group slot; the upper winding frame and the lower winding frame are stacked up and down, and a row of B coil wire holes that horizontally penetrate along the front-to-back direction to the rear side of the upper winding frame is set at the lower part of the front side surface of the upper winding frame, and the total length of the row of B coil wire holes in the left-right direction is not less than the H sensor wire hole. The length of the sensor group slot in the left-right direction; a row of B coil wire holes is also provided on the upper part of the front side of the lower winding frame horizontally penetrating the rear side thereof in the front-to-back direction; the positions of the two rows of B coil wire holes are directly opposite in the up-down direction and are used for winding the B coil; the B coil is obtained by winding the insulated wire on the two rows of B coil wire holes on the upper winding frame and the lower winding frame; two H coils, two H coil pads and one H coil partition constitute a sensor group, which is assembled in the order of one H coil, one H coil pad, one H coil partition, one H coil pad and one H coil; The component PCB board in the H coil is placed horizontally in the left-right direction, the H coil copper wire is wound in the middle position of the PCB board in the front-back direction, H coil screw fixing holes are set at both ends of the PCB board, and through holes are set at both ends of the H coil pad and the H coil partition. The positions of the above through holes are directly opposite to the positions of the H coil screw fixing holes in the vertical direction, and the sensor group is assembled by adding screws; the middle part of the H coil pad is a through hole for accommodating the H coil copper wire; the two terminals of the H coil copper wire of each H coil are connected to the external measurement circuit through the conductive line through the H coil outlet hole; The upper magnetic yoke, the lower magnetic yoke and the exciting winding constitute the exciting module of the measuring device. The upper magnetic yoke and the lower magnetic yoke have the same structure and size, and are both "U"-shaped structural members with a certain thickness. The "U"-shaped structural member is connected by a horizontal connecting edge and two vertical edges. The exciting winding is arranged in the middle of the horizontal connecting edges of the upper magnetic yoke and the lower magnetic yoke. The lower magnetic yoke is arranged with its opening facing upward in the middle position between the two base side plates, and its two vertical edges are respectively fixed in the positioning notches on the left and right side surfaces of the aluminum alloy pad; the upper magnetic yoke is placed with its opening facing downward on the top of the lower magnetic yoke, and the two positions are directly opposite, and its horizontal connecting edge is located above the top plate; the width of the lower magnetic yoke in the front-to-back direction is The length is the same as the width of the lower winding frame in the front-to-back direction to ensure the smoothness of the magnetic flux circuit; the front side surface of the lower magnetic yoke and the front side surface of the lower winding frame are located on the same plane, and the top surface of the lower magnetic yoke and the top surface of the lower winding frame are located on the same horizontal plane; the distance between the left and right inner sides of the open end of the lower magnetic yoke is equal to the length of the lower winding frame in the left-right direction; one terminal of the excitation winding on the upper magnetic yoke and one terminal of the excitation winding on the lower magnetic yoke are electrically connected through the terminal post, so that the two excitation windings are connected in series, and the other terminal of the excitation winding on the upper magnetic yoke and the other terminal of the excitation winding on the lower magnetic yoke connect the two excitation windings to the external measurement circuit; The horizontal stress applying device on the handwheel slide side is composed of a handwheel, a slide, a handwheel slide fixing plate, a handwheel slide polished rod, a handwheel slide lead screw, a handwheel slide-sensor adapter, a handwheel slide side pressure sensor, a handwheel slide side sensor-lower clamp adapter, an upper clamp on the handwheel slide side, and a lower clamp on the handwheel slide side; a threaded hole is provided in the middle of the slide along the left and right directions, and a through hole is provided on the front and rear sides respectively along the left and right directions; the handwheel slide fixing plate is a structure with a "U"-shaped support frame on the top and a support rod connected to the bottom, the slide is arranged in the "U"-shaped support frame of the handwheel slide fixing plate, and the side plates on the left and right ends of the "U"-shaped support frame. Each of the opposite sides is provided with a through hole along the left and right directions; the middle part of the handwheel slide screw is arranged in the threaded hole of the slide, and the outer surface of the handwheel slide screw is meshed and connected with the inner surface of the threaded hole of the slide; the left end of the handwheel slide screw passes through the through hole on the left end side plate of the "U"-shaped support frame of the handwheel slide fixing plate and is fixedly connected with the handwheel, and the right end of the handwheel slide screw is rotatably connected with the through hole on the right end side plate of the "U"-shaped support frame through a bearing and an end cover; a handwheel slide polished rod is respectively arranged in the through holes on the front and rear sides of the slide, and the two handwheel slide polished rods are arranged parallel to the handwheel slide screw and the left and right ends thereof are respectively fixed on the left and right side plates of the "U"-shaped support frame; The bottom of the handwheel slide fixing plate is fixedly connected to the bottom plate; there is a handwheel slide-sensor connecting piece on the upper part of the slide, one end of which is fixed to the upper surface of the slide with screws, and the other end is horizontally connected to the pressure sensor on the handwheel slide side; the other side of the pressure sensor on the handwheel slide side is connected to the handwheel slide side sensor-lower clamp adapter, and the other side of the handwheel slide side sensor-lower clamp adapter is fixedly connected to the middle position of the left side surface of the lower clamp on the handwheel slide side by screws; The lower clamp on the handwheel slide and the upper clamp on the handwheel slide are rectangular structures made of aluminum alloy with the same size, and two screw holes are arranged on the upper clamp on the handwheel slide, and two screw holes are also arranged on the lower clamp on the handwheel slide. The screw holes on the lower clamp on the handwheel slide are directly opposite to the screw holes on the upper clamp on the handwheel slide in the vertical direction. The lower clamp on the handwheel slide and the upper clamp on the handwheel slide are clamped by adding screws to clamp the rectangular sample horizontally placed between the two screw holes in the up-down direction; rubber material is arranged on the clamping surface between the lower clamp on the handwheel slide and the upper clamp on the handwheel slide; The motor side horizontal stress applying device is composed of a motor upper clamp, a motor lower clamp, a motor polished rod, a bearing fixing plate, a motor side sensor-lower clamp adapter, a motor side pressure sensor, a motor-sensor adapter, a motor fixing plate, a motor reinforcement plate, a motor damping plate, and a servo motor; the motor upper clamp and the motor lower clamp are rectangular parallelepiped structures made of aluminum alloy materials of the same size, and two screw holes are provided on the motor upper clamp, and two screw holes are also provided on the motor lower clamp. The screw holes on the motor upper clamp and the screw holes on the motor lower clamp are directly opposite in the vertical direction, and the motor upper clamp and the motor lower clamp are clamped by adding screws to clamp the rectangular sample horizontally placed between the two screw holes in the up and down direction; rubber material is provided on the clamping surface between the motor upper clamp and the motor lower clamp; A motor polished rod is fixedly arranged in the middle of the front and rear ends of the right side surface of the motor lower clamp, and a threaded connector is fixedly arranged in the middle position of the right side surface, one end of the motor side sensor-lower clamp adapter is connected to the connector, and the other end is connected to one end of the motor side pressure sensor; the other end of the motor side pressure sensor is connected to one end of the motor-sensor adapter, and the other end of the motor-sensor adapter is connected to the threaded column of the servo motor; the middle of the right end surface of the motor-sensor adapter is a concave threaded hole, and the inner surface of the threaded hole is meshed and connected with the threaded column of the servo motor; The bearing fixing plate is arranged directly below the motor side pressure sensor, and a notch is opened in the middle of the top thereof for accommodating the motor side pressure sensor. A through hole along the left and right directions is arranged on the front and rear sides thereof respectively, and bearings are arranged in the two through holes, and two motor polished rods on the motor lower clamp are respectively arranged in the bearings in the two through holes; The motor fixing plate is fixed at the middle position of the right side of the bearing fixing plate, and the motor fixing plate and the bearing fixing plate have screw holes at the bottom, and are fixedly connected to the bottom plate by installing screws; a motor reinforcement plate is fixed to the top of the right side of the motor fixing plate by screws, and a motor damping plate is fixed to the upper part of the right side of the motor reinforcement plate. Both the motor reinforcement plate and the motor damping plate are provided with through holes for accommodating the threaded column of the servo motor. The servo motor is fixed to the right side of the motor damping plate and its threaded column is horizontally arranged on the side facing the motor side pressure sensor; The top surface of the lower magnetic yoke is in the same horizontal plane as the top surface of the lower clamp of the motor and the top surface of the lower clamp on the handwheel slide. The central axis of the threaded column of the servo motor, the central axis of the sensor-lower clamp adapter on the handwheel slide, and the center line of the lower winding skeleton in the left-right direction are all parallel and coplanar. When using the horizontal stress applying device on the handwheel slide side, use the horizontal stress applying device on the motor side as the fixed end to fix the threaded column of the motor; The longitudinal stress applying device includes a jack pressure sensor and a jack; during measurement, the jack is placed at the exact center of the upper winding frame, the jack pressure sensor is placed at the center of the top of the jack, and then the jack is pressurized. When the jack pressure sensor contacts the top plate, longitudinal stress begins to be generated and is transmitted to the rectangular sample through the upper winding frame.

[0008] Furthermore, the present invention provides a broadband magnetic property measurement system under temperature-biaxial stress coordinated loading, characterized in that the system comprises the measurement device as described above, and also comprises a measurement circuit; the measurement circuit comprises a differential amplifier, an NI acquisition card, an industrial computer, a power amplifier, a protection resistor, a matching capacitor, a stress control device, and a temperature control device; The two terminals of the B coil and the two conductive wires of each H coil are electrically connected to the signal input terminal of a differential amplifier respectively; the signal output terminal of each differential amplifier is connected to the signal input terminal of the NI acquisition card; the NI acquisition card is inserted into the inside of the industrial computer to transmit the input data to the LabVIEW program of the industrial computer; the signal output terminal of the NI acquisition card is connected to the input port of the power amplifier, one terminal of the output channel of the power amplifier is connected to the protection resistor, the other end of the protection resistor is connected to the matching capacitor, the other end of the matching capacitor is connected to one end of the excitation winding on the upper yoke, the other end of the excitation winding on the upper yoke is connected in series with one end of the excitation winding on the lower yoke through the terminal, and the other end of the excitation winding on the lower yoke is connected to the other terminal of the output channel of the power amplifier to form a closed loop; The signal input end of the stress control device is connected to the industrial computer, and the signal output end thereof is electrically connected to the servo motor. The industrial computer controls the stress control device to realize the forward and reverse control of the servo motor; the pressure sensor on the motor side is electrically connected to the force display on the motor side to read the magnitude of the tensile stress and the compressive stress in real time; The pressure sensor on the handwheel slide is electrically connected to the handwheel side force display to read the magnitude of tensile stress and compressive stress in real time; the jack pressure sensor is electrically connected to the jack force display to read the magnitude of compressive stress in real time; The temperature control device includes a temperature controller and a thermocouple. The temperature controller is electrically connected to the terminal of the temperature loading device to provide working current for the cast aluminum heating plate. At the same time, the industrial computer is electrically connected to the temperature controller to set the target temperature for the PID control program inside the temperature controller. The sensing end of the thermocouple is set in the middle of the gap between the upper winding skeleton and the lower winding skeleton, and is in direct contact with the rectangular sample, and its signal output end is electrically connected to the temperature controller. The thermocouple detects the temperature of the upper surface of the rectangular sample and feeds it back to the thermostat. The PID control program inside the thermostat controls the on-off of the power line connected to the cast aluminum heating plate according to the feedback temperature to adjust the power of the cast aluminum heating plate to adjust its temperature.

[0009] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention solves the problem that traditional magnetic measuring devices cannot simulate and test the magnetic properties of soft magnetic materials in electrical equipment under multiple working conditions. On the upper side of the rectangular sample, a jack with a force sensor and a display screen is used to apply normal pressure, a motor with a force sensor and a handwheel slide are used to apply horizontal tensile and compressive stresses, and a heater and a cast aluminum heating plate are used to adjust the temperature. Multi-axis stress and temperature working condition simulation is achieved to obtain magnetic property data that is more in line with the actual working conditions of the electrical equipment, thereby more accurately guiding the optimal design of the electrical equipment.

[0010] 2. The present invention solves the problem that traditional magnetic measurement devices cannot accurately apply tensile stress and compressive stress to most soft magnetic materials. By fixing a large-range, low-precision force sensor on the motor side of the device, it is used to measure the stress of magnetic materials with high mechanical strength such as oriented silicon steel and non-oriented silicon steel with a thickness of more than 0.1mm during the measurement process; and fixing a small-range, high-precision force sensor on the handwheel slide side, it is used to measure the stress of magnetic materials with low mechanical strength such as amorphous alloys and nanocrystalline with a thickness of about 0.02mm during the measurement. The same device can measure electrical magnetic materials of different thicknesses and different stiffnesses.

[0011] 3. The present invention solves the problem that normal stress may damage the exciting winding, B coil and H coil. The present invention evenly and symmetrically winds the exciting winding on the upper and lower magnetic yokes, winds the B coil in a frame with an upper layer of phenolic resin and a lower layer of aluminum alloy, and buries the H coil inside the upper phenolic resin frame, thereby protecting the exciting winding, B coil and H coil from being damaged by the jack.

[0012] 4. The upper phenolic resin skeleton of the present invention adopts a lid deep hole structure, which makes it more convenient to replace and check the H sensor of the present invention. In order to ensure the measurement accuracy, a double-layer H coil is used to make up for the problem that the single-layer H coil may not measure accurately if it is not close to the rectangular sample. The two H coils form an array along the normal of the rectangular sample and calculate the magnetic field strength on the surface of the rectangular sample by linear interpolation, which has higher accuracy.

[0013] 5. The number of turns of the excitation winding wire of the present invention is adjustable and has a large current resistance, which basically ensures that all types of rectangular samples can be measured to saturation. The adjustment range of the number of turns of the wire is 100, 200, 300, 400, 500 and 600 turns. For samples of different thicknesses and tests of different frequencies, excitation windings with appropriate numbers of turns can be used.

[0014] 6. The present invention uses amorphous alloy 1K101 to make double yokes. The yoke length is 230mm and the inner magnetic path length is 200mm. It can effectively reduce the leakage magnetic flux caused by the vertical entry of magnetic flux into the rectangular sample. The yoke width is 50mm, and a variety of rectangular samples with different widths can be measured and a margin can be left for insulating gaskets. The yoke height is 135mm. The upper yoke can leave a margin to place the jack, and the lower yoke can leave a margin to place the heating module. In addition, the material has a high saturation magnetic permeability and lower loss than general materials, so it is not easy to heat up, and the amorphous alloy yoke can increase the frequency test range, and can test most of the electrical soft magnetic materials currently used in electrical equipment.

[0015] 7. The present invention uses phenolic plates to insulate the device. The phenolic plates cover all parts except the surface where the cast aluminum heating plate and the aluminum alloy frame meet, ensuring that heat is efficiently transferred to the rectangular sample and can effectively isolate the temperature generated by the heating device, so that the outside of the device will not generate excessively high temperatures.

[0016] 8. The present invention is easy to install, simple to operate, and has a high safety factor. Most of the materials in the device are aluminum alloy, and are all fixed by M8 screws, which has strong stability. The present invention is designed with a control hole for the jack, which reduces the difficulty of operation.

[0017] 9. The present invention has good promotion value. The test results can provide guidance for the design of motors and transformers, reduce production costs, and generate huge benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The figure is a schematic diagram of the overall structure of an embodiment of a broadband magnetic property measurement device under temperature-biaxial stress coordinated loading of the present invention.

[0019] Figure 2 The figure is a schematic diagram of assembling a longitudinal stress applying device and a winding skeleton of an embodiment of a broadband magnetic property measuring device under temperature-biaxial stress coordinated loading of the present invention.

[0020] Figure 3 This is a structural schematic diagram (disassembly diagram) of a winding skeleton of an embodiment of a wide-band magnetic property measurement device under temperature-biaxial stress coordinated loading of the present invention.

[0021] Figure 4 It is a structural schematic diagram of a temperature loading device of an embodiment of a broadband magnetic property measurement device under temperature-biaxial stress coordinated loading of the present invention (disassembly diagram, left side azimuth view).

[0022] Figure 5 The present invention is a schematic structural diagram of a motor-side horizontal stress applying device of an embodiment of a broadband magnetic property measuring device under temperature-biaxial stress coordinated loading.

[0023] Figure 6 The present invention is a schematic structural diagram of a horizontal stress applying device on the handwheel slide side of an embodiment of a broadband magnetic property measuring device under temperature-biaxial stress coordinated loading of the present invention.

[0024] Figure 7 It is a structural schematic diagram (disassembly diagram) of a sensor group of one embodiment of a broadband magnetic property measurement device under temperature-biaxial stress coordinated loading of the present invention.

[0025] Figure 8 It is a structural schematic diagram of an H coil of an embodiment of a broadband magnetic property measurement device under temperature-biaxial stress coordinated loading of the present invention.

[0026] Fig. 9 The structure and principle diagram of an embodiment of a broadband magnetic property measurement system under temperature-biaxial stress coordinated loading of the present invention.

[0027] In the figure: 1. differential amplifier; 2. NI acquisition card; 3. industrial computer; 4. power amplifier; 5. protection resistor; 6. matching capacitor; 7. stress control device; 8. temperature control device; 9. measuring device; 10. top plate; 11. side plate with holes; 12. longitudinal stress applying device; 13. side plate without holes; 14. excitation winding; 15. temperature loading device; 16. sensor module; 17. side plate of the base; 18. horizontal stress applying device on the handwheel slide side; 19. horizontal stress applying device on the motor side; 20. Bottom plate; 21. Upper winding skeleton; 22. Skeleton cover; 23. H coil outlet hole; 24. B coil wire hole; 25. Lower winding skeleton; 26. Phenolic resin insulation board; 27. Cast aluminum heating plate; 28. Aluminum alloy pad; 29. ​​Upper yoke; 30. Lower yoke; 31. Jack pressure sensor; 32. Jack; 33. H sensor group slot; 34. Temperature loading device terminal; 35. Upper clamp on the motor side; 36. Lower clamp on the motor side; 37. Motor polished rod; 38. Bearing fixing plate; 39. Motor side sensor-lower clamp adapter; 40. Motor side pressure sensor; 41. Motor-sensor adapter ;42. Motor fixing plate;43. Motor reinforcement plate;44. Motor damping plate;45. Servo motor;46. Handwheel;47. Slide;48. Handwheel slide fixing plate;49. Handwheel slide bare rod;50. Handwheel slide lead screw;51. Handwheel slide-sensor connector;52. Handwheel slide side pressure sensor;53. Handwheel slide side sensor-lower clamp adapter;54. Handwheel slide side upper clamp;55. Handwheel slide side lower clamp;56. H coil;57. H coil pad;58. H coil partition;59. H coil screw fixing hole;60. H coil welding hole;61. PCB board;62. H coil copper wire. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention are given below. The specific embodiments are only used to further illustrate the present invention in detail and do not limit the protection scope of the claims of this application.

[0029] The present invention provides a broadband magnetic property measuring device under temperature-biaxial stress coordinated loading, the device comprising a top plate 10, a side plate with holes 11, a longitudinal stress applying module 12, a side plate without holes 13, an excitation module, a temperature loading device 15, a sensor module 16, a side plate of a base 17, a horizontal stress applying device 18 on the side of a handwheel slide, a horizontal stress applying device 19 on the side of a motor, and a bottom plate 20.

[0030] The bottom plate 20, top plate 10, base side plate 17, non-perforated side plate 13, perforated side plate 11 and aluminum alloy pad 28 in temperature loading device 15 provide mechanical support for the whole measuring device. The measuring device has two base side plates 17, which are fixedly arranged on the front and rear sides of the upper surface of the bottom plate 20 in parallel, facing and centering. The aluminum alloy pad 28 is horizontally fixed on the top between the two base side plates 17; the perforated side plate 11 and the non-perforated side plate 13 have the same size, and the two are fixedly arranged on the front and rear sides of the top surface of the aluminum alloy pad 28 in parallel, facing and centering. Since the top plate 10 is horizontally fixed on the upper part between the perforated side plate 11 and the non-perforated side plate 13, it is fixedly connected with the perforated side plate 11 and the non-perforated side plate 13 by horizontal screws. The lower part of the perforated side plate 11 is provided with a longitudinal stress loading hole facing the non-perforated side plate 13; the bottom plate 20 is also provided with a bottom plate hand support on both sides to facilitate the measurement personnel to carry.

[0031] As an embodiment, the front and rear sides of the top surface of the aluminum alloy backing plate 28 are symmetrically provided with an inner groove along the left-right direction, and the bottoms of the side plate with holes 11 and the side plate without holes 13 are correspondingly located in the two inner grooves, and the side plate with holes 11 and the side plate without holes 13 are fixed in the corresponding grooves by screws in the up-down direction and the left-right direction. Since the side plate with holes 11 and the side plate without holes 13 also have to bear the force generated by the longitudinal stress applying module 12, the inner groove setting can improve the safety of the measuring device.

[0032] The temperature loading device 15 comprises a phenolic resin heat insulation board 26, a cast aluminum heating board 27, an aluminum alloy pad 28 and a temperature loading device terminal 34. An inner groove is arranged in the center of the upper surface of the aluminum alloy pad 28, and a wire through hole is arranged at the bottom of the inner groove, which passes through the bottom surface of the aluminum alloy pad 28; a positioning groove is arranged symmetrically in the middle position of the left and right side surfaces, which passes through the up and down directions; the outer size of the phenolic resin heat insulation board 26 matches the size of the inner groove on the aluminum alloy pad 28, and a heating groove is arranged in the center of the upper surface; the phenolic resin heat insulation board 26 is arranged in the inner groove on the aluminum alloy pad 28, and the bottom of the heating groove is aligned with the wire through hole of the aluminum alloy pad 28. A through hole is set at the corresponding position; the cast aluminum heating plate 27 is set in the heating groove of the phenolic resin insulation plate 26; two electric heating wires arranged in an anti-parallel manner are buried inside the cast aluminum heating plate 27, and the power connection ends of the two heating wires are respectively wound on two temperature loading device terminals 34, and the two temperature loading device terminals 34 are set in the wire through holes of the aluminum alloy pad 28. The outer sides of the two temperature loading device terminals 34 are connected to the external measurement circuit, and the external measurement circuit provides working current for the heating wires, thereby heating the rectangular sample.

[0033] The phenolic resin insulation board 26 is wrapped around the outer periphery of the cast aluminum heating plate 27. The phenolic resin insulation board 26 is used to isolate the heat loss generated by the cast aluminum heating plate 27 to the outside, ensuring that the heat diffuses to the periphery of the device as little as possible; the aluminum alloy pad 28 is wrapped around the outer periphery of the phenolic resin insulation board 26, mainly used to fix the side panels and withstand the compressive stress applied downward by the jack, playing a supporting role.

[0034] The sensor module 16 comprises an upper winding skeleton 21, a skeleton cover 22, a lower winding skeleton 25, an H coil 56, an H coil pad 57, and an H coil partition 58, wherein the H coil 56 further comprises an H coil screw fixing hole 59, an H coil welding hole 60, a PCB board 61, and an H coil copper wire 62. The upper winding skeleton 21, the skeleton cover 22, and the lower winding skeleton 25 constitute a winding skeleton, which is arranged in the middle position of the upper surface of the aluminum alloy pad 28 along the left-right direction, and its setting direction is parallel to the perforated side plate 33, its left-right length is equal to the left-right length of the aluminum alloy pad 28, and its front-to-back width is not greater than the front-to-back width of the inner groove opening of the cast aluminum heating plate 27. The upper winding skeleton 21 and the lower winding skeleton 25 have the same length and width. A two-step notch is provided in the middle of the upper winding skeleton 21, wherein the lower one is a rectangular H sensor group slot 33, and the upper one is a notch matching the outer dimensions of the skeleton cover 22. As an embodiment, the skeleton cover 22 is a cross-shaped structure. The H sensor group slot 33 is used to set the sensor group, and an H coil outlet hole 23 is provided at the top of the front side wall of the H sensor group slot 33. The upper winding skeleton 21 and the lower winding skeleton 25 are connected to each other. The upper and lower frames 25 are stacked opposite each other. A row of B coil wire holes 24 are provided at the lower part of the front side of the upper winding frame 21, which extend horizontally from the front to the rear side thereof. The total length of the row of B coil wire holes 24 in the left-right direction is not less than the length of the H sensor group slot 33 in the left-right direction. A row of B coil wire holes 24 are also provided at the upper part of the front side of the lower winding frame 25, which extend horizontally from the front to the rear side thereof. The positions of the two rows of B coil wire holes 24 are opposite to each other in the up-down direction, and are used to wind the B coils. The B coils are obtained by winding insulated wires (such as copper wires coated with insulating paint) on the two rows of B coil wire holes 24 on the upper winding frame 21 and the lower winding frame 25, so that the rectangular sample can be surrounded and the induced voltage generated by the rectangular sample can be measured. Two H coils 56, two H coil pads 57 and one H coil partition 58 constitute a sensor group, which is assembled in the order of one H coil 56, one H coil pad 57, H coil partition 58, one H coil pad 57 and one H coil 56; the component PCB board 61 of the H coil 56 is placed horizontally in the left-right direction, and the H coil copper wire 62 is wound in the front-back direction (to ensure that it is orthogonal to the rectangular sample. During measurement, the magnetic flux flows through the rectangular sample, thereby generating an induced voltage signal) in the middle position of the PCB board 61, and H coil screw fixing holes 59 are set at both ends of the PCB board. Through holes are set at both ends of the H coil pad 57 and the H coil partition 58. The position of the above-mentioned through holes is directly opposite to the position of the H coil screw fixing hole 59 in the vertical direction. The sensor group is assembled by adding screws; the middle part of the H coil pad 57 is a through hole for accommodating the H coil copper wire 62 to prevent the H coil 56 from directly contacting the H coil partition 58 and generating force to crush the coil.The main function of the H coil partition 58 is to isolate the double-layer H coil 56 to prevent direct contact from forming a short circuit between turns and affecting the measurement.

[0035] The two terminals of the H coil copper wire 62 of each H coil 56 are connected to the external measurement circuit through the H coil outlet hole 23 via the conductive line; specifically, both ends of the PCB board 61 of each H coil 56 are provided with a plurality of rows of H coil welding holes 60, and the number of each row of H coil welding holes 60 is two, and the two H coil welding holes 60 in a row are connected through the conductive line inside the PCB; the H coil copper wire 62 of the H coil 56 selects a row of H coil welding holes 60 on the left and right sides of the PCB board 61 for connection, wherein the two H coil welding holes 60 close to the H coil copper wire 62 are used to connect the two terminals of the H coil copper wire 62, and the two H coil welding holes 60 far from the H coil copper wire 62 are respectively connected to one end of the two conductive wires, and the other ends of the two conductive wires are connected to the external measurement circuit after passing through the H coil outlet hole 23. This embodiment adopts a double-layer H coil 56 for the purpose of measuring more accurate values, and its main function is to induce the magnetic flux flowing through the rectangular sample and then generate an induced voltage, so as to calculate the magnetic field strength of the rectangular sample.

[0036] When preparing for measurement, the rectangular sample to be measured is set between the upper winding skeleton 21 and the lower winding skeleton 25, and the width of the rectangular sample to be measured in the front-to-back direction is not greater than the width of the upper winding skeleton 21 in the front-to-back direction; then remove the skeleton cover 22, and put the sensor group into the H sensor group slot 33; lead the sensor group lead wire from the H coil outlet hole 23, connect it to the measurement circuit, and finally cover the skeleton cover 22; the upper and lower B coil wire holes 24 are used to wind the B coil, mainly for measuring the induced voltage generated on the rectangular sample, and finally the induced voltage generated by the B coil is connected to the measurement circuit.

[0037] The upper magnetic yoke 29, the lower magnetic yoke 30, and the exciting winding 14 constitute the exciting module of the measuring device. The upper magnetic yoke 29 and the lower magnetic yoke 30 have the same structure and size, and are both "U"-shaped structural members with a certain thickness. The "U"-shaped structural member is connected by a horizontal connecting edge and two vertical edges; the exciting winding 14 is arranged in the middle of the horizontal connecting edges of the upper magnetic yoke 29 and the lower magnetic yoke 30; the lower magnetic yoke 30 is arranged in the middle position between the two base side plates 17 with its opening facing upward, and its two vertical edges are respectively fixed in the positioning notches on the left and right side surfaces of the aluminum alloy pad 28; the upper magnetic yoke 29 is placed with its opening facing downward At the top of the lower yoke 30, the two are directly opposite each other, and their horizontal connecting edge is located above the top plate 10; the width of the lower yoke 30 in the front-to-back direction is the same as the width of the lower winding frame 25 in the front-to-back direction, ensuring the smoothness of the magnetic flux circuit; the front side surface of the lower yoke 30 and the front side surface of the lower winding frame 25 are located on the same plane, and the top surface of the lower yoke 30 and the top surface of the lower winding frame 25 are located on the same horizontal plane, so that the rectangular sample can be naturally pressed by the yoke without any protrusion; the distance between the left and right inner sides of the open end of the lower yoke 30 is equal to the length of the lower winding frame 25 in the left-to-right direction. One terminal of the excitation winding 14 on the upper magnetic yoke 29 is electrically connected to one terminal of the excitation winding 14 on the lower magnetic yoke 30 through a terminal post, so that the two excitation windings 14 are connected in series, and the other terminal of the excitation winding 14 on the upper magnetic yoke 29 and the other terminal of the excitation winding 14 on the lower magnetic yoke 30 connect the two excitation windings 14 to an external measurement circuit.

[0038] The upper yoke 29 and the lower yoke 30 are made of amorphous alloy 1K101. The yoke length is 230 mm and the inner magnetic path length is 200 mm, which can effectively reduce the leakage magnetic flux caused by the vertical entry of the magnetic flux into the rectangular sample. The yoke width is 50 mm, which can measure a variety of rectangular samples of different widths and leave a margin for insulating gaskets. The yoke height is 135 mm.

[0039] The handwheel slide side horizontal stress applying device 18 is composed of a handwheel 46, a slide 47, a handwheel slide fixing plate 48, a handwheel slide polished rod 49, a handwheel slide screw 50, a handwheel slide-sensor adapter 51, a handwheel slide side pressure sensor 52, a handwheel slide side sensor-lower clamp adapter 53, a handwheel slide side upper clamp 54, and a handwheel slide side lower clamp 55. The working principle of the handwheel slide is to rotate the handwheel slide screw 50 by rotating the handwheel 46, and because the slide 47 is provided with a thread inside and is placed on the handwheel slide screw 50, the slide 47 will move forward or backward along the handwheel slide polished rod 49.

[0040] The middle of the slide 47 is provided with a threaded hole along the left-right direction, and the front and rear sides thereof are each provided with a through hole along the left-right direction; the handwheel slide fixing plate 48 is a structure with a "U"-shaped support frame at the top and a support rod connected at the bottom, the slide 47 is arranged in the "U"-shaped support frame of the handwheel slide fixing plate 48, and the side plates at the left and right ends of the "U"-shaped support frame are each provided with a through hole along the left-right direction; the middle of the handwheel slide screw 50 is arranged in the threaded hole of the slide 47, and the outer surface of the handwheel slide screw 50 is meshed and connected with the inner surface of the threaded hole of the slide 47. The left end of the handwheel slide screw 50 passes through the through hole on the left end side plate of the "U"-shaped support frame of the handwheel slide fixing plate 48 and is fixedly connected with the handwheel 46, and the right end of the handwheel slide screw 50 is rotatably connected with the through hole on the right end side plate of the "U"-shaped support frame through a bearing and an end cover. A handwheel slide rod 49 is respectively arranged in the through holes on the front and rear sides of the slide 47. The two handwheel slide rods 49 are arranged parallel to the handwheel slide screw 50 and their left and right ends are respectively fixed to the left and right side panels of the "U"-shaped support frame.

[0041] The bottom of the handwheel slide fixing plate 48 is fixedly connected to the bottom plate 20, which ensures the stability of the handwheel slide module during operation; the upper part of the slide 47 is provided with a handwheel slide-sensor connector 51, one end of which is fixed to the upper surface of the slide 47 with screws, and the other end is horizontally connected to the handwheel slide side pressure sensor 52. When the handwheel 46 is turned, the slide 47 will have a tendency to move left and right, and the generated force will be received and recorded by the handwheel slide side pressure sensor 52. The other side of the handwheel slide side pressure sensor 52 is connected to the handwheel slide side sensor-lower clamp adapter 53, and the other side of the handwheel slide side sensor-lower clamp adapter 53 is fixedly connected to the middle position of the left side surface of the handwheel slide side lower clamp 55 by screws.

[0042] The lower clamp 55 on the handwheel slide side and the upper clamp 54 on the handwheel slide side are rectangular structures made of aluminum alloy with the same size, and two screw holes are provided on the upper clamp 54 on the handwheel slide side. Two screw holes are also provided on the lower clamp 55 on the handwheel slide side. The screw holes on the lower clamp 55 on the handwheel slide side are directly opposite to the screw holes on the upper clamp 54 on the handwheel slide side in the vertical direction. The lower clamp 55 on the handwheel slide side and the upper clamp 54 on the handwheel slide side are clamped by adding screws to clamp the rectangular sample horizontally placed between the two screw holes in the up and down direction; rubber material is provided on the clamping surface between the lower clamp 55 on the handwheel slide side and the upper clamp 54 on the handwheel slide side to increase the friction between the clamping surface and the rectangular sample, so as to ensure that the rectangular sample will not slide when the motor pulls or presses the rectangular sample.

[0043] During measurement, tensile and compressive stresses are applied to the rectangular sample by rotating the handle of the handwheel 46 forward and reversely, and the magnitude of the force generated is displayed in real time on the handwheel side force display through the handwheel slide side pressure sensor 52. The handwheel slide side pressure sensor 52 adopts the Zhongnuo ZNLBM-IIX-50kg type high-precision dual-purpose tension and pressure sensor, with a maximum load of 50kg. The shape is a cylinder with a diameter of 41mm and a height of 25mm, and M8 threaded columns extend from both ends. The part where the handwheel slide-sensor connector 51 is connected to the handwheel slide side pressure sensor 52 is a rectangular parallelepiped with a side length of 10mm. The middle part is provided with an M8 threaded through hole. One end is fixed to the slide 47 by a screw, and the other end is fixed with the threaded column of the handwheel slide side pressure sensor 52. The handwheel slide side sensor-lower clamp adapter 53 is a cylinder with a diameter of 40mm and a height of 20mm. There are M8 threaded through holes at the center of both ends. One end is fixed to the handwheel slide side lower clamp 55 by screws, and the other end is fixed to the threaded column of the handwheel slide side pressure sensor 52. The handwheel slide adopts the Ouli transmission linear guide slide.

[0044] The motor side horizontal stress applying device 19 is composed of a motor upper clamp 35, a motor lower clamp 36, a motor bare rod 37, a bearing fixing plate 38, a motor side sensor-lower clamp adapter 39, a motor side pressure sensor 40, a motor-sensor adapter 41, a motor fixing plate 42, a motor reinforcement plate 43, a motor shock absorbing plate 44, and a servo motor 45. The upper motor clamp 35 and the lower motor clamp 36 are rectangular structures made of aluminum alloy materials of the same size, and two screw holes are provided on the upper motor clamp 35, and two screw holes are also provided on the lower motor clamp 36. The screw holes on the upper motor clamp 35 and the screw holes on the lower motor clamp 36 are directly opposite in the vertical direction. The upper motor clamp 35 and the lower motor clamp 36 are clamped by adding screws to clamp the rectangular sample horizontally placed between the two screw holes in the upper and lower directions; rubber material is provided on the clamping surface between the upper motor clamp 35 and the lower motor clamp 36 to increase the friction between the clamping surface and the rectangular sample, so as to ensure that the rectangular sample will not slide when the motor pulls or presses the rectangular sample.

[0045] A motor polished rod 37 is fixedly disposed in the middle of the front and rear ends of the right side of the motor lower clamp 36, and a threaded connector is fixedly disposed in the middle position of the right side. One end of the motor side sensor-lower clamp adapter 39 is connected to the connector, and the other end is connected to one end of the motor side pressure sensor 40; the other end of the motor side pressure sensor 40 is connected to one end of the motor-sensor adapter 41, and the other end of the motor-sensor adapter 41 is connected to the threaded column (i.e., the output shaft) of the servo motor 45. The middle of the right end face of the motor-sensor adapter 41 is a concave threaded hole, and the inner surface of the threaded hole is meshed and connected with the threaded column of the servo motor 45; The bearing fixing plate 38 is arranged directly below the motor side pressure sensor 40, and a slot is opened in the middle of the top thereof for accommodating the motor side pressure sensor 40. A through hole is arranged along the left-right direction on the front and rear sides thereof respectively, and bearings are arranged in the two through holes. The two motor rods 37 on the motor lower layer fixture 36 are respectively arranged in the bearings in the two through holes. When the servo motor 45 is working, the motor lower layer fixture 36 moves left or right along the motor rods 37, thereby providing tensile and compressive stresses for the rectangular sample piece. The length of the threaded hole on the right end face of the motor-sensor adapter 41 along the left-right direction is the maximum distance limit value of the movement of the motor lower layer fixture 36.

[0046] The motor fixing plate 42 is fixed in the middle of the right side of the bearing fixing plate 38, and the motor fixing plate 42 and the bearing fixing plate 38 have screw holes at the bottom, and are fixedly connected to the bottom plate 20 by installing screws to resist the force generated when the motor rotates and ensure the stability of the motor module. The top of the right side of the motor fixing plate 42 is fixed with a motor reinforcement plate 43 by screws, and the upper part of the right side of the motor reinforcement plate 43 is fixed with a motor damping plate 44. The motor reinforcement plate 43 and the motor damping plate 44 are both provided with through holes for accommodating the threaded column of the servo motor 45. The servo motor 45 is fixed on the right side of the motor damping plate 44 and its threaded column is horizontally arranged on the side facing the motor side pressure sensor 40.

[0047] The top surface of the lower yoke 30 is in the same horizontal plane as the top surface of the motor lower clamp 36 and the top surface of the handwheel slide side lower clamp 55, and the center axis of the threaded column of the servo motor 45, the center axis of the handwheel slide side sensor-lower clamp adapter 53 and the center line of the lower winding skeleton 25 in the left and right directions are all parallel and coplanar.

[0048] When the hand wheel slide side horizontal stress applying device 18 is used, the motor side horizontal stress applying device 19 is used as a fixed end to fix the threaded column of the motor, that is, the two devices do not work at the same time.

[0049] The motor damping plate 44 is made of ABS resin material, which has good flexibility and impact resistance, and can better protect the motor and prevent the motor from colliding with metal materials. The magnitude of the force generated during the measurement is collected by the motor side pressure sensor 40 and displayed in real time in the motor side force display.

[0050] The motor side pressure sensor 40 adopts the Zhongnuo ZNLBM-IIX-300kg type high-precision tension and pressure dual-purpose sensor, with a maximum load of 300kg. It is a cylinder with a diameter of 41mm and a height of 25mm, and M8 threaded columns extend from both ends. The motor-sensor adapter 41 is an aluminum alloy cylinder with a diameter of 30mm and a height of 45mm. There is an M8 threaded hole at the center of one end, which is fixed with the threaded column of the motor side pressure sensor 40, and an M14 threaded column at the center of the other end, which is fixed with the servo motor 45. The motor side sensor-lower layer fixture adapter 39 is a nylon cylinder with a diameter of 40mm and a height of 20mm. There are M8 threaded through holes at the center of both ends. One end is fixed with the motor lower layer fixture 36 by screws, and the other end is fixed with the threaded column of the motor side pressure sensor 40. The servo motor 45 adopts the RCP2-RA6C motor of Japan IAI Company.

[0051] The longitudinal stress applying device 12 includes a jack pressure sensor 31 and a jack 32. During measurement, the jack 32 is placed at the exact center of the upper winding skeleton 21, and the jack pressure sensor 31 is placed at the center of the top of the jack 32. Then, the jack 32 is pressurized. When the jack pressure sensor 31 contacts the top plate 10, longitudinal stress begins to be generated and is transmitted to the rectangular sample through the upper winding skeleton 21. The pressure collected by the jack pressure sensor 31 is displayed in the jack force display.

[0052] The jack pressure sensor 31 adopts the Zhongnuo ZNHM-IIX-10t pressure sensor, with a maximum load of 10t and a cylindrical shape of 58mm in diameter and 30mm in height. The jack 32 adopts the RSC-1050 hydraulic jack, and the maximum pressure generated is 10t.

[0053] Furthermore, the present invention provides a broadband magnetic property measurement system under temperature-biaxial stress coordinated loading, the system includes the measuring device 9 as described above, and also includes a measuring circuit; the measuring circuit includes a differential amplifier 1, an NI acquisition card 2, an industrial computer 3, a power amplifier 4, a protection resistor 5, a matching capacitor 6, a stress control device 7, and a temperature control device 8.

[0054] The two terminals of the B coil and the two conductive wires of each H coil 56 are electrically connected to the signal input terminal of a differential amplifier 1 respectively. The amplification factor of each differential amplifier 1 is selected according to the size of the signal, and the amplification factor can be selected from 1 to 1000 times; the signal output terminal of each differential amplifier 1 is connected to the signal input terminal of the NI acquisition card 2; the NI acquisition card 2 is inserted into the inside of the industrial computer 3 to transmit the input data to the LabVIEW program of the industrial computer 3; the signal output terminal of the NI acquisition card 2 is connected to the input port of the power amplifier 4, and one terminal of the output channel of the power amplifier 4 is connected to the protection resistor 5, the other end of the protection resistor 5 is connected to the matching capacitor 6, and the other end of the matching capacitor 6 is connected to one end of the excitation winding 14 on the upper yoke 29, and the other end of the excitation winding 14 on the upper yoke 29 is connected in series with one end of the excitation winding 14 on the lower yoke 30 through a terminal, and the other end of the excitation winding 14 on the lower yoke 30 is connected to another terminal of the output channel of the power amplifier 4 to form a closed loop. The power amplifier 4 amplifies the output signal of the NI acquisition card 2 controlled by the LabVIEW program.

[0055] The signal input end of the stress control device 7 is connected to the industrial computer 3, and the signal output end thereof is electrically connected to the servo motor 45. The industrial computer 3 controls the stress control device 7 to realize the forward and reverse control of the servo motor 45. The motor side pressure sensor 40 is electrically connected to the motor side force display to read the magnitude of the tensile stress and the compressive stress in real time. The motor side force display adopts the ZN4S model. The handwheel slide side pressure sensor 52 is electrically connected to the handwheel side force display to read the magnitude of tensile stress and compressive stress in real time. The handwheel side force display adopts ZN4S model; the jack pressure sensor 31 is electrically connected to the jack force display to read the magnitude of compressive stress in real time. The jack force display adopts ZN5H model.

[0056] The temperature control device 8 includes a temperature controller and a thermocouple. The temperature controller is electrically connected to the temperature loading device terminal 34 to provide working current for the cast aluminum heating plate 27. At the same time, the industrial computer 3 is electrically connected to the temperature controller to set the target temperature for the PID control program inside the temperature controller. The sensing end of the thermocouple is set in the middle of the gap between the upper winding skeleton 21 and the lower winding skeleton 25, and is in direct contact with the rectangular sample. Its signal output end is electrically connected to the temperature controller. The thermocouple detects the temperature of the upper surface of the rectangular sample and feeds it back to the temperature controller. The PID control program inside the temperature controller controls the on-off of the power line connected to the cast aluminum heating plate 27 according to the feedback temperature to adjust the power of the cast aluminum heating plate 27 to adjust its temperature.

[0057] The differential amplifier 1 is an instrument used to amplify the signal, and its magnification is adjustable. When the cross-sectional area of ​​the rectangular sample to be measured is very small, if the signal is directly transmitted to the NI acquisition card 2, the B coil voltage value and the H coil voltage value and other parameter values ​​collected by the NI acquisition card 2 will be very low, and the signal provided to the industrial computer for controlling the excitation will be inaccurate. At this time, the signal needs to be amplified by the differential amplifier 1. The differential amplifier 1 is built with power electronic components. When there is a voltage input to the differential amplifier 1, the differential amplifier 1 will amplify and output the signal. Usually, multiple differential amplifiers 1 are used together; the NI acquisition card 2 is a component used to obtain parameters such as the B coil voltage value and the H coil voltage value in the measurement. It is connected to the external acquisition box through the signal transmission line on the back of the industrial computer 3. It has eight signal input channels and two signal output channels; the industrial computer 3 is a device used by the measurement personnel to set the parameters of the rectangular sample, voltage and current constraints, excitation mode, and store data. The NI acquisition card 2 is inserted into the industrial computer 3 to transmit the collected signal to the industrial computer 3; the power amplifier The function of the amplifier 4 is to amplify the signal. When a signal is input to the power amplifier 4, the power amplifier 4 will amplify and output the signal, which is generally used to amplify the output signal of the NI acquisition card 2; the function of the protection resistor 5 is to protect the entire circuit, and the instrument will not be damaged when a short circuit occurs in the experiment; the function of the matching capacitor 6 is to compensate for reactive power. When the primary side voltage and current are in phase, it is considered that the impedance matching reaches the optimal state, ensuring the accuracy of data measurement; the function of the stress control device 7 is to control the rotation of the servo motor 45, thereby applying tensile stress and compressive stress to the rectangular sample, specifically the motor drive module; the function of the temperature control device 8 is to regulate the temperature on the sample so that the sample temperature reaches the set value.

[0058] The working principle and process of the measurement system of the present invention are shown in the following steps: Step 1: Prepare the sensor module and a rectangular sample suitable for the device size. Wind the B coil evenly in the B coil wire hole, ensuring that each turn of the coil is orthogonal to the frame and has a certain distance from the frame surface. Then put the H sensor module into the sensor slot, lead the sensor wire from the H coil wire hole, then cover the frame cover, and then place the rectangular sample to be tested between the upper and lower winding frames supported by a 0.5mm thick rubber gasket. After placement, pull out the gasket. If the amorphous alloy or nanocrystalline rectangular sample is measured and no longitudinal stress is required, there is no need to pull out the gasket.

[0059] Step 2: Place the upper yoke to press down the two ends of the rectangular sample and make it completely match the lower yoke. If the measurement requires the application of tensile or compressive stress, place the two ends of the rectangular sample between the upper and lower clamps and tighten the clamps to firmly fix the rectangular sample.

[0060] Step 3: Connect the measurement device, connect the excitation winding to the power amplifier, connect the B coil and the H coil to the input of the differential amplifier, the differential amplifier adjusts the amplification factor according to the input signal, and then connect the output of the differential amplifier to the acquisition card to form a negative feedback closed loop. The wiring of the excitation circuit and the signal acquisition circuit is completed.

[0061] Step 4: Adjust the jack, temperature controller, motor or handwheel slide to the required state according to the different working conditions of the measurement conditions, and turn on the power after ensuring that there are no errors.

[0062] Step 5: Observe the magnetic flux density, magnetic field strength and magnetostrictive waveform. Adjust the parameters of the LabVIEW program inside the industrial computer. The parameters of the LabVIEW program will feed back to the NI acquisition card, making the output signal it generates continuously larger. The output signal is then input into the power amplifier. The signal output by the power amplifier is then used to excite the sample, which can continuously increase the amplitude of the excitation voltage and store the required magnetic characteristic data at any time until the sample reaches saturation; Step 6: After the required data is stored, slowly reduce the excitation signal to demagnetize the rectangular sample to be tested; Step 7: Repeat steps 4, 5, and 6 until the magnetic property test under the required frequency and excitation mode is completed, and the magnetic induction intensity and magnetic field intensity trajectory diagrams of the sample under different working conditions (force / heating), different frequencies, and different excitation currents are obtained. Then, the data can be analyzed to obtain the loss model to calculate the loss.

[0063] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A broadband magnetic property measurement device under temperature-biaxial stress coordinated loading, characterized in that: The device comprises a top plate, a side plate with holes, a longitudinal stress applying module, a side plate without holes, an excitation module, a temperature loading device, a sensor module, a side plate of a base, a horizontal stress applying device on the side of a handwheel slide, a horizontal stress applying device on the side of a motor, and a bottom plate; The measuring device has two base side plates, which are parallel, opposite and centrally fixed on the front and rear sides of the upper surface of the bottom plate, and the aluminum alloy pad is horizontally fixed on the top between the two base side plates; the side plate with holes and the side plate without holes have the same size, and the two are parallel, opposite and centrally fixed on the front and rear sides of the top surface of the aluminum alloy pad, and because the top plate is horizontally fixed on the upper part between the side plate with holes and the side plate without holes, it is fixedly connected with the side plate with holes and the side plate without holes by horizontal screws; the lower part of the side plate with holes is provided with a longitudinal stress loading hole that is opposite to the side plate without holes; The temperature loading device comprises a phenolic resin heat insulation board, a cast aluminum heating plate, an aluminum alloy pad and a temperature loading device terminal; an inner groove is arranged in the center of the upper surface of the aluminum alloy pad, and a wire through hole is arranged at the bottom of the inner groove to penetrate the bottom surface of the aluminum alloy pad; a positioning groove is symmetrically arranged in the middle position of the left and right sides to penetrate the upper and lower directions; the outer size of the phenolic resin heat insulation board matches the size of the inner groove on the aluminum alloy pad, and a heating groove is arranged in the center of the upper surface; the phenolic resin heat insulation board is arranged in the inner groove on the aluminum alloy pad, and its A through hole is provided at the bottom of the heating slot and at a position directly opposite to the wire through hole of the aluminum alloy pad; the cast aluminum heating plate is arranged in the heating slot of the phenolic resin insulation plate; two heating wires arranged in reverse parallel are buried inside the cast aluminum heating plate, and the power connection ends of the two heating wires are respectively wound on two temperature loading device terminals, and the two temperature loading device terminals are arranged in the wire through hole of the aluminum alloy pad, and the outer sides of the two temperature loading device terminals are connected to the external measurement circuit, and the external measurement circuit provides working current for the heating wire, thereby heating the rectangular sample; The sensor module includes an upper winding skeleton, a skeleton cover, a lower winding skeleton, an H coil, an H coil pad, and an H coil partition, wherein the H coil includes a PCB board and an H coil copper wire; the upper winding skeleton, the skeleton cover, and the lower winding skeleton constitute a winding skeleton, which is arranged in the middle position on the upper surface of the aluminum alloy pad along the left-right direction, and its setting direction is parallel to the perforated side plate, its left-right length is equal to the left-right length of the aluminum alloy pad, and its front-to-back width is not greater than the front-to-back width of the inner groove opening of the cast aluminum heating plate; the upper winding skeleton and the lower winding skeleton The length and width are the same, and a two-step notch is set in the middle of the upper winding frame, of which the lower one is a rectangular H sensor group slot, and the upper one is a notch matching the outer dimensions of the frame cover; the H sensor group slot is used to set the sensor group, and an H coil outlet hole is set on the top of the front side wall of the H sensor group slot; the upper winding frame and the lower winding frame are stacked up and down, and a row of B coil wire holes that horizontally penetrate along the front-to-back direction to the rear side of the upper winding frame is set at the lower part of the front side surface of the upper winding frame, and the total length of the row of B coil wire holes in the left-right direction is not less than the H sensor wire hole. The length of the sensor group slot in the left-right direction; a row of B coil wire holes is also provided on the upper part of the front side of the lower winding frame horizontally penetrating the rear side thereof in the front-to-back direction; the positions of the two rows of B coil wire holes are directly opposite in the up-down direction and are used for winding the B coil; the B coil is obtained by winding the insulated wire on the two rows of B coil wire holes on the upper winding frame and the lower winding frame; two H coils, two H coil pads and one H coil partition constitute a sensor group, which is assembled in the order of one H coil, one H coil pad, one H coil partition, one H coil pad and one H coil; The component PCB board in the H coil is placed horizontally in the left-right direction, the H coil copper wire is wound in the middle position of the PCB board in the front-back direction, H coil screw fixing holes are set at both ends of the PCB board, and through holes are set at both ends of the H coil pad and the H coil partition. The positions of the above through holes are directly opposite to the positions of the H coil screw fixing holes in the vertical direction, and the sensor group is assembled by adding screws; the middle part of the H coil pad is a through hole for accommodating the H coil copper wire; the two terminals of the H coil copper wire of each H coil are connected to the external measurement circuit through the conductive line through the H coil outlet hole; The upper magnetic yoke, the lower magnetic yoke and the exciting winding constitute the exciting module of the measuring device. The upper magnetic yoke and the lower magnetic yoke have the same structure and size, and are both "U"-shaped structural members with a certain thickness. The "U"-shaped structural member is connected by a horizontal connecting edge and two vertical edges. The exciting winding is arranged in the middle of the horizontal connecting edges of the upper magnetic yoke and the lower magnetic yoke. The lower magnetic yoke is arranged with its opening facing upward in the middle position between the two base side plates, and its two vertical edges are respectively fixed in the positioning notches on the left and right side surfaces of the aluminum alloy pad. The upper magnetic yoke is placed with its opening facing downward on the top of the lower magnetic yoke, and the two positions are directly opposite, and its horizontal connecting edge is located above the top plate. The width of the lower magnetic yoke in the front-to-back direction is The length is the same as the width of the lower winding frame in the front-to-back direction to ensure the smoothness of the magnetic flux circuit; the front side surface of the lower magnetic yoke and the front side surface of the lower winding frame are located on the same plane, and the top surface of the lower magnetic yoke and the top surface of the lower winding frame are located on the same horizontal plane; the distance between the left and right inner sides of the open end of the lower magnetic yoke is equal to the length of the lower winding frame in the left-right direction; one terminal of the excitation winding on the upper magnetic yoke and one terminal of the excitation winding on the lower magnetic yoke are electrically connected through the terminal post, so that the two excitation windings are connected in series, and the other terminal of the excitation winding on the upper magnetic yoke and the other terminal of the excitation winding on the lower magnetic yoke connect the two excitation windings to the external measurement circuit; The horizontal stress applying device on the handwheel slide side is composed of a handwheel, a slide, a handwheel slide fixing plate, a handwheel slide polished rod, a handwheel slide lead screw, a handwheel slide-sensor adapter, a handwheel slide side pressure sensor, a handwheel slide side sensor-lower clamp adapter, an upper clamp on the handwheel slide side, and a lower clamp on the handwheel slide side; a threaded hole along the left and right directions is arranged in the middle of the slide, and a through hole along the left and right directions is arranged on the front and rear sides respectively; the handwheel slide fixing plate is a structure with a "U"-shaped support frame on the top and a support rod connected to the bottom, the slide is arranged in the "U"-shaped support frame of the handwheel slide fixing plate, and the side plates on the left and right ends of the "U"-shaped support frame. Each of the opposite sides is provided with a through hole along the left and right directions; the middle part of the handwheel slide screw is arranged in the threaded hole of the slide, and the outer surface of the handwheel slide screw is meshed and connected with the inner surface of the threaded hole of the slide; the left end of the handwheel slide screw passes through the through hole on the left end side plate of the "U"-shaped support frame of the handwheel slide fixing plate and is fixedly connected with the handwheel, and the right end of the handwheel slide screw is rotatably connected with the through hole on the right end side plate of the "U"-shaped support frame through a bearing and an end cover; a handwheel slide polished rod is respectively arranged in the through holes on the front and rear sides of the slide, and the two handwheel slide polished rods are arranged parallel to the handwheel slide screw and the left and right ends thereof are respectively fixed on the left and right side plates of the "U"-shaped support frame; The bottom of the handwheel slide fixing plate is fixedly connected to the bottom plate; there is a handwheel slide-sensor connecting piece on the upper part of the slide, one end of which is fixed to the upper surface of the slide with screws, and the other end is horizontally connected to the pressure sensor on the handwheel slide side; the other side of the pressure sensor on the handwheel slide side is connected to the handwheel slide side sensor-lower clamp adapter, and the other side of the handwheel slide side sensor-lower clamp adapter is fixedly connected to the middle position of the left side surface of the lower clamp on the handwheel slide side by screws; The lower clamp on the handwheel slide and the upper clamp on the handwheel slide are rectangular structures made of aluminum alloy with the same size, and two screw holes are arranged on the upper clamp on the handwheel slide, and two screw holes are also arranged on the lower clamp on the handwheel slide. The screw holes on the lower clamp on the handwheel slide are directly opposite to the screw holes on the upper clamp on the handwheel slide in the vertical direction. The lower clamp on the handwheel slide and the upper clamp on the handwheel slide are clamped by adding screws to clamp the rectangular sample horizontally placed between the two screw holes in the up-down direction; rubber material is arranged on the clamping surface between the lower clamp on the handwheel slide and the upper clamp on the handwheel slide; The motor side horizontal stress applying device is composed of a motor upper clamp, a motor lower clamp, a motor polished rod, a bearing fixing plate, a motor side sensor-lower clamp adapter, a motor side pressure sensor, a motor-sensor adapter, a motor fixing plate, a motor reinforcement plate, a motor damping plate, and a servo motor; the motor upper clamp and the motor lower clamp are rectangular parallelepiped structures made of aluminum alloy materials of the same size, and two screw holes are provided on the motor upper clamp, and two screw holes are also provided on the motor lower clamp. The screw holes on the motor upper clamp and the screw holes on the motor lower clamp are directly opposite in the vertical direction, and the motor upper clamp and the motor lower clamp are clamped by adding screws to clamp the rectangular sample horizontally placed between the two screw holes in the up and down direction; rubber material is provided on the clamping surface between the motor upper clamp and the motor lower clamp; A motor polished rod is fixedly arranged in the middle of the front and rear ends of the right side surface of the motor lower clamp, and a threaded connector is fixedly arranged in the middle position of the right side surface, one end of the motor side sensor-lower clamp adapter is connected to the connector, and the other end is connected to one end of the motor side pressure sensor; the other end of the motor side pressure sensor is connected to one end of the motor-sensor adapter, and the other end of the motor-sensor adapter is connected to the threaded column of the servo motor; the middle of the right end surface of the motor-sensor adapter is a concave threaded hole, and the inner surface of the threaded hole is meshed and connected with the threaded column of the servo motor; The bearing fixing plate is arranged directly below the motor side pressure sensor, and a notch is opened in the middle of the top thereof for accommodating the motor side pressure sensor. A through hole along the left and right directions is arranged on the front and rear sides thereof respectively, and bearings are arranged in the two through holes, and two motor polished rods on the motor lower clamp are respectively arranged in the bearings in the two through holes; The motor fixing plate is fixed at the middle position of the right side of the bearing fixing plate, and the motor fixing plate and the bearing fixing plate have screw holes at the bottom, and are fixedly connected to the bottom plate by installing screws; a motor reinforcement plate is fixed to the top of the right side of the motor fixing plate by screws, and a motor damping plate is fixed to the upper part of the right side of the motor reinforcement plate. Both the motor reinforcement plate and the motor damping plate are provided with through holes for accommodating the threaded column of the servo motor. The servo motor is fixed to the right side of the motor damping plate and its threaded column is horizontally arranged on the side facing the motor side pressure sensor; The top surface of the lower magnetic yoke is in the same horizontal plane as the top surface of the lower clamp of the motor and the top surface of the lower clamp on the handwheel slide. The central axis of the threaded column of the servo motor, the central axis of the sensor-lower clamp adapter on the handwheel slide, and the center line of the lower winding skeleton in the left-right direction are all parallel and coplanar. When using the horizontal stress applying device on the handwheel slide side, use the horizontal stress applying device on the motor side as the fixed end to fix the threaded column of the motor; The longitudinal stress applying device includes a jack pressure sensor and a jack; during measurement, the jack is placed at the exact center of the upper winding frame, the jack pressure sensor is placed at the center of the top of the jack, and then the jack is pressurized. When the jack pressure sensor contacts the top plate, longitudinal stress begins to be generated and is transmitted to the rectangular sample through the upper winding frame.

2. The broadband magnetic property measurement device under temperature-biaxial stress coordinated loading according to claim 1, characterized in that: There are bottom plate hand support openings on both sides of the bottom plate; the frame cover is a cross-shaped structure.

3. The broadband magnetic property measurement device under temperature-biaxial stress coordinated loading according to claim 1, characterized in that: The front and rear sides of the top surface of the aluminum alloy pad are symmetrically provided with an inner groove opening along the left and right direction. The bottoms of the side panels with holes and the side panels without holes are correspondingly located in the two inner groove openings, and the side panels with holes and the side panels without holes are fixed in the corresponding grooves by screws in the up and down directions and the left and right directions.

4. The broadband magnetic property measuring device under temperature-biaxial stress coordinated loading according to claim 1, characterized in that: Both ends of the PCB board of each H coil are provided with several rows of H coil welding holes, the number of each row of H coil welding holes is two, and the two H coil welding holes in one row are connected through the conductive wire inside the PCB; the H coil copper wire of the H coil selects one row of H coil welding holes on the left and right sides of the PCB board for connection, wherein the two H coil welding holes close to the H coil copper wire are used to connect the two terminal ends of the H coil copper wire, and the two H coil welding holes far from the H coil copper wire are respectively connected to one end of the two conductive wires, and the other ends of the two conductive wires are connected to the external measurement circuit after passing through the H coil outlet hole.

5. The broadband magnetic property measurement device under temperature-biaxial stress coordinated loading according to claim 1, characterized in that: The pressure sensor on the handwheel slide side adopts Zhongnuo ZNLBM-IIX-50kg type high-precision dual-purpose tension and pressure sensor with a maximum load of 50kg. The shape is a cylinder with a diameter of 41mm and a height of 25mm, with M8 threaded columns extending from both ends; the part where the handwheel slide-sensor connector is connected to the pressure sensor on the handwheel slide side is a rectangular block with a side length of 10mm, and an M8 threaded through hole is provided in the middle part. One end is fixed to the slide by a screw, and the other end is fixed to the threaded column of the pressure sensor on the handwheel slide side; the handwheel slide side sensor-lower clamp adapter is a cylinder with a diameter of 40mm and a height of 20mm. There are M8 threaded through holes at the center of both ends. One end is fixed to the lower clamp on the handwheel slide side by a screw, and the other end is fixed to the threaded column of the pressure sensor on the handwheel slide side.

6. The broadband magnetic property measurement device under temperature-biaxial stress coordinated loading according to claim 1, characterized in that: When the servo motor is working, the motor lower fixture moves left or right along the motor polished rod, thereby providing tensile and compressive stresses to the rectangular sample. The length of the threaded hole on the right end face of the motor-sensor adapter along the left and right directions is the maximum distance limit for the movement of the motor lower fixture.

7. The broadband magnetic property measurement device under temperature-biaxial stress coordinated loading according to claim 1, characterized in that: The motor damping plate is made of ABS resin material.

8. The broadband magnetic property measurement device under temperature-biaxial stress coordinated loading according to claim 1, characterized in that: The motor side pressure sensor adopts Zhongnuo ZNLBM-IIX-300kg type high-precision dual-purpose tension and pressure sensor with a maximum load of 300kg. Its appearance is a cylinder with a diameter of 41mm and a height of 25mm, with M8 threaded columns extending from both ends; the motor-sensor adapter is an aluminum alloy cylinder with a diameter of 30mm and a height of 45mm. There is an M8 threaded hole at the center of one end, which is fixed with the threaded column of the motor side pressure sensor, and there is an M14 threaded column at the center of the other end, which is fixed with the servo motor; the motor side sensor-lower layer fixture adapter is a nylon cylinder with a diameter of 40mm and a height of 20mm. There are M8 threaded through holes at the center of both ends. One end is fixed to the motor lower layer fixture by screws, and the other end is fixed with the threaded column of the motor side pressure sensor.

9. The broadband magnetic property measurement device under temperature-biaxial stress coordinated loading according to claim 1, characterized in that: The jack pressure sensor uses Zhongnuo ZNHM-IIX-10t pressure sensor with a maximum load of 10t and a cylindrical shape with a diameter of 58mm and a height of 30mm. The jack uses RSC-1050 hydraulic jack, which generates a maximum pressure of 10t.

10. A broadband magnetic property measurement system under temperature-biaxial stress coordinated loading, characterized in that: The system comprises the measuring device according to any one of claims 1 to 9, and further comprises a measuring circuit; the measuring circuit comprises a differential amplifier, an NI acquisition card, an industrial computer, a power amplifier, a protection resistor, a matching capacitor, a stress control device, and a temperature control device; The two terminals of the B coil and the two conductive wires of each H coil are electrically connected to the signal input terminal of a differential amplifier respectively; the signal output terminal of each differential amplifier is connected to the signal input terminal of the NI acquisition card; the NI acquisition card is inserted into the inside of the industrial computer to transmit the input data to the LabVIEW program of the industrial computer; the signal output terminal of the NI acquisition card is connected to the input port of the power amplifier, one terminal of the output channel of the power amplifier is connected to the protection resistor, the other end of the protection resistor is connected to the matching capacitor, the other end of the matching capacitor is connected to one end of the excitation winding on the upper yoke, the other end of the excitation winding on the upper yoke is connected in series with one end of the excitation winding on the lower yoke through the terminal, and the other end of the excitation winding on the lower yoke is connected to the other terminal of the output channel of the power amplifier to form a closed loop; The signal input end of the stress control device is connected to the industrial computer, and the signal output end thereof is electrically connected to the servo motor. The industrial computer controls the stress control device to realize the forward and reverse control of the servo motor; the pressure sensor on the motor side is electrically connected to the force display on the motor side to read the magnitude of the tensile stress and the compressive stress in real time; The pressure sensor on the handwheel slide is electrically connected to the handwheel side force display to read the magnitude of tensile stress and compressive stress in real time; the jack pressure sensor is electrically connected to the jack force display to read the magnitude of compressive stress in real time; The temperature control device includes a temperature controller and a thermocouple. The temperature controller is electrically connected to the terminal of the temperature loading device to provide working current for the cast aluminum heating plate. At the same time, the industrial computer is electrically connected to the temperature controller to set the target temperature for the PID control program inside the temperature controller. The sensing end of the thermocouple is set in the middle of the gap between the upper winding skeleton and the lower winding skeleton, and is in direct contact with the rectangular sample, and its signal output end is electrically connected to the temperature controller. The thermocouple detects the temperature of the upper surface of the rectangular sample and feeds it back to the thermostat. The PID control program inside the thermostat controls the on-off of the power line connected to the cast aluminum heating plate according to the feedback temperature to adjust the power of the cast aluminum heating plate to adjust its temperature.

Images