A detection instrument for measuring the bending force of a large-scale litz wire and a detection method thereof

Abstract

The application relates to a detection instrument for measuring the bending force of a large-size Litz wire and a detection method thereof, and belongs to the technical field of Litz wire detection. The detection instrument comprises a detection table, an automatic wire feeding device for driving the Litz wire to feed along the x-axis direction, a center shaft assembly arranged on the detection table and used for fixing the bending center position of the sample wire, a fixed clamping assembly arranged on one side of the center shaft assembly, a bending assembly arranged on the other side of the center shaft assembly, a wire cutting device arranged between the fixed clamping assembly and the center shaft assembly and used for cutting the Litz wire into a plurality of sample wires, a force detection device used for detecting the stress data of the sample wire in the bending process in real time, and a control processing system in signal connection with the bending assembly and the force detection device. The application replaces the traditional visual inspection or hand feeling test by accurately quantifying the soft bending force of the Litz wire, improves the reliability and stability of the detection, and improves the automation degree of the detection and reduces the labor intensity.

Description

Technical Field

[0001] This application relates to the field of Litz wire testing, and more particularly to a testing instrument for measuring the bending force of large Litz wires. Background Technology

[0002] Litz wire is made of multiple strands of mutually insulated single-strand wires twisted together and is widely used in applications with operating frequencies between 10kHz and 5MHz. In high-frequency applications, due to the skin effect and proximity effect of current, high-frequency currents generate eddy current losses, and these losses increase with the increase of current frequency. These eddy current losses caused by high-frequency magnetic fields can be overcome by the twisted structure of Litz wire. Litz wire has the characteristics of high voltage resistance, high frequency resistance, good flexibility and elasticity, and the ability to withstand high mechanical stress. Rectangular Litz wire after the squaring process also has advantages such as good dimensional stability, high conductor filling rate, and high slot fill factor after coiling.

[0003] Litz wire is typically wound into coils for use in high-frequency transformers, high-frequency sensors, high-frequency motors, large energy storage motors, and large drive motors. In China, there is rarely specialized equipment for winding large Litz coils; they are usually wound manually by operators or semi-manually using equipment. The flexibility and bendability of Litz wire significantly impact the winding process. If the Litz wire is too stiff, it will make the winding process much more difficult, and may even cause significant deformation during bending, resulting in coil failure. Therefore, testing the flexibility and bending force of Litz wire before winding is crucial. Currently, there are no unified standards or specific testing methods for this property of Litz wire in China, and the assessment of its flexibility and bending force is very simple and primitive, usually relying on manual "feel" or visual inspection. This leads to significant errors between different evaluators, which can seriously affect the winding process or even cause coil failure. Summary of the Invention

[0004] To improve the reliability and stability of testing and reduce labor intensity, this application provides a testing instrument and testing method for measuring the bending force of large Litz wires.

[0005] Firstly, this application provides a testing instrument for measuring the bending force of large Litz wires, which adopts the following technical solution:

[0006] An instrument for measuring the bending force of large Litz wires includes:

[0007] Testing station;

[0008] An automatic feed device is used to drive the Litz wire to feed along the x-axis.

[0009] A central shaft assembly, mounted on the testing platform, is used to fix the center position of the bending of the template line;

[0010] A fixed clamping assembly is provided on one side of the central shaft assembly and is used to clamp one end of the template.

[0011] A bending assembly is located on the other side of the central shaft assembly and is used to drive the other end of the template to bend around the bending center;

[0012] A wire cutting device, located between the fixed clamping assembly and the central shaft assembly, is used to cut Litz wire into several sample wires;

[0013] Force detection device, used for real-time online detection of force data on the template during bending process;

[0014] The control and processing system is connected to the bending assembly and the force detection device for controlling the bending motion and processing the force data.

[0015] Optionally, the central shaft assembly includes a turntable frame and multiple central shaft bodies of different diameters mounted on the turntable frame. Each central shaft body is arranged along the z-axis direction. The turntable frame is mounted below the surface of the testing table. The turntable frame is equipped with a lifting drive device that drives each central shaft body to move up and down along the z-axis direction. The testing table is equipped with a moving drive device that drives the turntable frame to move along the y-axis direction. The testing table is equipped with a clearance hole that allows the central shaft body to pass through the surface of the table. The clearance hole is an elongated hole and its length direction is parallel to the y-axis direction.

[0016] Optionally, the detection platform is equipped with a contour scanning device for identifying the geometric features of the sample section, and the contour scanning device and the turntable are respectively connected to the control processing system.

[0017] Optionally, the fixing and clamping assembly includes a first L-shaped support plate and a clamping plate disposed on one side of the first L-shaped support plate. The first L-shaped support plate is fixed on the testing table, and the clamping plate is used to hold one end of the template against the side plate of the first L-shaped support plate.

[0018] The bending assembly includes an arc-shaped slide rail and a second L-shaped support plate. The arc-shaped slide rail is located below the table surface of the testing station. An extension is provided on the electric slide of the arc-shaped slide rail. An arc-shaped groove is provided on the table surface of the testing station for the extension to pass through and move to avoid obstacles. The second L-shaped support plate is connected to the extension.

[0019] When the second L-shaped support plate is in the initial position, the bottom plate of the second L-shaped support plate supports the lower end of the template line, and its opening is set towards the template line.

[0020] Optionally, the upper end of the central shaft body is provided with a threaded section, the threaded section is threadedly connected to a pressure cap, the lower end of the pressure cap is provided with a washer, and the bottom plate of the first L-shaped support plate is provided with a first pressure sensor, the first pressure sensor is signal-connected to an alarm module.

[0021] Optionally, the automatic feed device includes a plurality of drive wheels rotatably mounted on a testing table, the plurality of drive wheels being arranged along the x-axis direction, the testing table being provided with a pressing wheel for pressing the Litz wire onto the drive wheels, and the drive wheels being signal-connected to the control processing system.

[0022] Optionally, the force detection device is located on the side plate of the second L-shaped support plate, and the detection end of the force detection device is oriented towards the template line; the arc-shaped slide rail is signal-connected to the control and processing system, and the control and processing system is signal-connected to an operation interface and a display interface.

[0023] Secondly, this application also provides a testing method for a testing instrument used to measure the bending force of large Litz wires, employing the following technical solution:

[0024] A detection method using the above-mentioned detection instrument includes the following detection steps:

[0025] S1. Fixed template: The Litz wire is fed in by an automatic feeding device. After the template reaches the designated position, the template is clamped by a fixed clamping assembly.

[0026] S2. Call the center axis body: The cross-sectional shape and size of the template are automatically detected by the contour scanning device, and the detection results are transmitted to the control processing system. The control processing system selects the corresponding center axis body according to the preset range and controls the turntable to execute in place;

[0027] S3. Precisely position the center axis body: Raise the target center axis body to the working position and make the target center axis body abut against the center of the template bending;

[0028] S4. Input parameters and calibration: Set experimental parameters and perform zeroing calibration through the operation interface. Experimental parameters include sample type, bending motion angular velocity and number of experiments.

[0029] S5, Bending Test: Control the bending component to drive the sample line to bend around the central axis at a set angular velocity. The force detection device collects the force data in real time, and the control processing system records the angular displacement and time data synchronously. If it is a multiple experiment, the sample line that has completed the test is cut off by the wire cutting device, and then the steps S1-S5 are automatically repeated until the set number of experiments is completed.

[0030] S6. Output Results: Generate dynamic curves and statistical reports, and determine the qualification of the bending force of the Litz line.

[0031] Optionally, in step S5, under multiple experiment mode, the control processing system executes automatically:

[0032] S51. Generate a real-time force-time curve after each bending test is completed;

[0033] S52. After accumulating the set number of experiments, display all single experiment curves overlaid on the same coordinate system;

[0034] S53. Calculate the curve overlap rate based on formula (1):

[0035] Formula (1)

[0036] in, This represents the real-time force value in the nth experiment. This is the average force value from multiple experiments;

[0037] The overlap ratio η is used as an indicator to evaluate the uniformity of the softness of the Litz line.

[0038] In summary, this application includes at least one of the following beneficial technical effects:

[0039] 1. This application improves the reliability and stability of testing by accurately quantifying the flexible bending force of Litz wire, replacing traditional visual or tactile testing. The testing platform supports the coordinated operation of various functional modules, the automatic wire feeding device achieves accurate delivery of the sample wire, the central shaft assembly establishes a standard bending benchmark, the fixed clamping assembly and bending assembly work together to simulate real bending conditions, the wire cutting device automatically cuts the test sample wire, the force detection device captures dynamic force changes in real time, and the control and processing system integrates motion control and data analysis to achieve automation from wire feeding, positioning, bending to testing.

[0040] 2. This application uses a contour scanning device to accurately acquire the characteristic dimensions of the sample line, and then the control and processing system automatically matches a central axis body with an appropriate diameter. When testing small-sized sample lines, a small-diameter central axis body is selected to enhance the bending strain intensity, so that the slight resistance changes caused by conductor lattice slippage are fully amplified, avoiding the inability to effectively identify material deformation differences due to excessive bending radius. When testing large-sized sample lines, a large-diameter central axis is matched to suppress the bending strain intensity, preventing irreversible plastic deformation of the inner lattice of the conductor due to excessive compression. This intelligent matching mechanism simultaneously constrains the bending tests of Litz wires of different sizes within the sensitive range dominated by elastic deformation, ensuring the detectability of minute performance differences while protecting the structural integrity of large-sized sample lines, fundamentally solving the industry pain point of "inaccurate measurement of differences for small lines and inaccurate measurement of limits for large lines" in traditional uniaxial testing.

[0041] 3. This application establishes a highly automated testing process: a contour scanning device acquires sample section data to drive intelligent matching of the central axis, eliminating operational deviations from manual axis selection; a parametric calibration module automatically zeroes system errors, ensuring consistency of initial conditions for bending tests; and a flexible switching mechanism between single and multiple test modes meets testing scenarios with different accuracy requirements. This method, through the streamlined integration of mechanical positioning, motion control, and data acquisition, ensures that bending force tests of different batches and specifications of Litz wire operate within a unified benchmark system while minimizing manual intervention, thus improving the reliability of bending force detection. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the overall structure of a testing instrument for measuring the bending force of large Litz wires according to an embodiment of this application.

[0043] Figure 2 This is a control principle diagram illustrating the control processing system in the embodiments of this application.

[0044] Figure 3 This is a schematic diagram illustrating the structure of the automatic wire feeding device, the fixed clamping assembly, and the wire cutting device in the embodiments of this application.

[0045] Figure 4 This is a structural schematic diagram illustrating the positional relationship between the turntable frame and the testing table in the embodiments of this application.

[0046] Figure 5 This is a schematic diagram illustrating the structure of the central shaft assembly in the embodiments of this application.

[0047] Figure 6 This is a structural schematic diagram illustrating the positional relationship between the bending component and the turntable frame in the embodiments of this application.

[0048] Figure 7 This is a flowchart illustrating the detection method using the detection instrument in the embodiments of this application.

[0049] Explanation of reference numerals in the attached drawings: 1. Detection table; 11. Avoidance perforation; 12. Moving drive device; 13. Arc-shaped groove; 2. Automatic wire feeding device; 21. Drive wheel; 22. Pressure wheel; 3. Fixed clamping assembly; 31. First L-shaped support plate; 311. First pressure sensor; 32. Clamping plate; 4. Wire cutting device; 5. Central shaft assembly; 51. Turntable frame; 52. Central shaft body; 521. Threaded section; 522. Pressure cap; 523. Washer; 53. Lifting drive device; 6. Bending assembly; 61. Arc-shaped slide rail; 62. Second L-shaped support plate; 63. Protruding part; 7. Force detection device; 8. Control and processing system; 81. Operation interface; 82. Display interface; 9. Contour scanning device. Detailed Implementation

[0050] The following combination Figures 1-7 This application will be described in further detail below.

[0051] Example:

[0052] In a first aspect, embodiments of this application disclose a testing instrument for measuring the bending force of large Litz wires.

[0053] Reference Figure 1 A testing instrument for measuring the bending force of large Litz wire includes a testing platform 1 and, sequentially arranged on the testing platform 1, an automatic wire feeding device 2, a fixing clamping assembly 3, a wire cutting device 4, a central shaft assembly 5, and a bending assembly 6. The automatic wire feeding device 2 drives the Litz wire to feed along the x-axis, the central shaft assembly 5 fixes the bending center position of the wire, the fixing clamping assembly 3 clamps one end of the wire, the bending assembly 6 drives the other end of the wire to bend around the bending center, and the wire cutting device 4 cuts the Litz wire into several wires.

[0054] Reference Figure 1 and Figure 2 The bending assembly 6 is equipped with a force detection device 7, which is used to detect the force data of the template during the bending process in real time online. The force detection device 7 is connected to the control processing system 8. The bending assembly 6 and the wire cutting device 4 are respectively connected to the control processing system 8. The control processing system 8 is also connected to the operation interface 81 and the display interface 82.

[0055] This application improves the reliability and stability of testing by accurately quantifying the flexible bending force of Litz wire, replacing traditional visual or tactile testing. The testing platform 1 supports the coordinated operation of various functional modules, the automatic wire feeding device 2 realizes the precise delivery of the sample wire, the central shaft assembly 5 establishes a standard bending benchmark, the fixed clamping assembly 3 and the bending assembly 6 work together to simulate real bending conditions, the wire cutting device 4 automatically cuts the test sample wire, the force detection device 7 captures dynamic force changes in real time, the control and processing system 8 integrates motion control and data analysis, the display interface 82 outputs the force-time curve, and automatically calculates the maximum value, average value, standard deviation and other data of the bending force of the sample wire, generating an electronic report, realizing automation from wire feeding, positioning, bending, testing and result presentation.

[0056] Reference Figures 1-3 The automatic feed device 2 includes several drive wheels 21 rotatably mounted on the inspection table 1, arranged along the x-axis. The inspection table 1 is equipped with pressing wheels 22 for pressing the Litz wire onto the drive wheels 21. The drive wheels 21 have built-in meter counters and are connected to the control processing system 8. Thus, the drive wheels 21 and the pressing wheels 22 form a friction feed mechanism. The control processing system 8 precisely adjusts the feed speed and length to ensure the consistency of the sample wire segment length, which is especially suitable for the smooth transport of large-section Litz wire.

[0057] Reference Figure 1 and Figures 4-6 The central shaft assembly 5 includes a turntable frame 51 and multiple central shaft bodies 52 of different diameters mounted on the turntable frame 51. Each central shaft body 52 is arranged along the z-axis direction. The turntable frame 51 is located below the table surface of the testing table 1. A lifting drive device 53 is installed on the turntable frame 51 to drive each central shaft body 52 to rise and fall along the z-axis direction. A moving drive device 12 is installed on the testing table 1 to drive the turntable frame 51 to move along the y-axis direction. The testing table 1 has a clearance through hole 11 for the central shaft body 52 to pass through the table surface. The clearance through hole 11 is an elongated hole with its length direction parallel to the y-axis direction.

[0058] Reference Figure 1 and Figure 2 The detection table 1 is equipped with a contour scanning device 9 for identifying the geometric features of the sample line cross section. The contour scanning device 9 is fixed on the detection table 1 and is oriented towards the sample line. The contour scanning device 9 and the turntable frame 51 are respectively connected to the control processing system 8.

[0059] During testing, the contour scanning device 9 accurately acquires the characteristic dimensions of the sample line, and the control processing system 8 automatically matches the central axis body 52 with an appropriate diameter. When testing small-sized sample lines, a small-diameter central axis body 52 is selected to enhance the bending strain intensity, so that the slight resistance changes caused by conductor lattice slippage are fully amplified, avoiding the inability to effectively identify material deformation differences due to excessive bending radius. When testing large-sized sample lines, a large-diameter central axis is matched to suppress the bending strain intensity, preventing irreversible plastic deformation of the inner lattice of the conductor due to excessive compression. This intelligent matching mechanism simultaneously constrains the bending tests of Litz wires of different sizes within the sensitive range dominated by elastic deformation, ensuring the detectability of minute performance differences while protecting the structural integrity of large-sized sample lines, fundamentally solving the industry pain point of "inaccurate measurement of differences in small lines and inaccurate measurement of limits in large lines" in traditional uniaxial testing.

[0060] Reference Figure 1 and Figure 3 The fixed clamping assembly 3 includes a first L-shaped support plate 31 and a clamping plate 32 disposed on one side of the first L-shaped support plate 31. The first L-shaped support plate 31 is fixed on the testing table 1, and the clamping plate 32 is driven by a driver to clamp and hold one end of the sample line against the side plate of the first L-shaped support plate 31.

[0061] Reference Figure 1 , Figure 4 and Figure 6The bending assembly 6 includes an arc-shaped slide rail 61 and a second L-shaped support plate 62. The arc-shaped slide rail 61 is located below the table surface of the testing table 1 and is connected to the control processing system 8. An extension member 63 is provided on the electric slide of the arc-shaped slide rail 61. An arc-shaped groove 13 is provided on the table surface of the testing table 1 to allow the extension member 63 to pass through and move freely. The second L-shaped support plate 62 is fixedly connected to the extension member 63. When the second L-shaped support plate 62 is in its initial position, its bottom plate supports the lower end of the template line, and its opening faces the template line. A force detection device 7 is fixed to the side plate of the second L-shaped support plate 62, and the detection end of the force detection device 7 faces the template line. In this embodiment, the force detection device 7 is a second pressure sensor. By monitoring the bending resistance applied to the side plate of the second L-shaped support plate 62 during the bending process of the sample line in real time, the deformation resistance generated by the lattice slip inside the sample line is converted into an electrical signal. The signal is then processed by the control processing system 8 to generate a continuous bending force-time curve. The peak value of the bending resistance directly maps the limit of the Litz wire's ability to resist plastic deformation, while the change in the slope of the curve reflects the strain strengthening characteristics of the Litz wire conductor material. The two work together to quantitatively characterize the flexibility of the Litz wire.

[0062] Reference Figure 1 , Figure 3 and Figure 5 The upper end of the central shaft body 52 is coaxially integrally formed with a threaded section 521, which is threadedly connected to a pressure cap 522. A washer 523 is fixed to the lower end of the pressure cap 522. A first pressure sensor 311 is fixed to the bottom plate of the first L-shaped support plate 31, and the first pressure sensor 311 is signal-connected to an alarm module. In this way, the displacement of the template along the y-axis is limited by the cooperation of the side plate of the first L-shaped support plate 31 and the clamping plate 32, and the displacement of the template along the z-axis is limited by the cooperation of the bottom plate of the first L-shaped support plate 31 and the pressure cap 522, thereby ensuring that the bending center of the template strictly coincides with the axis of the selected central shaft body 52 during the bending test, thus improving the reliability of the test. In addition, the first pressure sensor 311 can provide feedback on the clamping force of the pressure cap 522 on the sample line. When the clamping force exceeds the limit, the alarm module 312 is triggered and the operation interface 81 prompts "clamping force exceeds the limit". At this time, the test needs to be stopped and the next section of sample line needs to be replaced to avoid the distortion of the test results caused by the deformation of the sample line under pressure.

[0063] Secondly, this application also discloses a testing method for a testing instrument used to measure the bending force of large Litz wires.

[0064] Reference Figure 7 A testing scheme for a testing instrument used to measure the bending force of large Litz wires includes the following steps:

[0065] S1. Fixing the template: The Litz wire is fed in by the automatic feeding device 2. After the template reaches the designated position, the template is clamped by the fixing clamping component 3.

[0066] S2. Calling the center axis body: The profile scanning device 9 automatically detects the cross-sectional shape and size of the template and transmits the detection results to the control processing system 8. The control processing system 8 selects the corresponding center axis body 52 according to the preset range and controls the turntable 51 to execute in place.

[0067] S3. Precisely position the center shaft body 52: Raise the target center shaft body 52 to the working position and make the target center shaft body 52 abut against the center of the template bending;

[0068] S4. Input parameters and calibration: Set experimental parameters and perform zeroing calibration through the operation interface 81. Experimental parameters include sample type, bending motion angular velocity and number of experiments.

[0069] S5, Bending Test: Control the bending component 6 to drive the sample line to bend around the central axis at a set angular velocity. The force detection device 7 collects the force data in real time, and the control processing system 8 records the angular displacement and time data simultaneously. If it is a multiple experiment, the sample line that has completed the test is cut off by the wire cutting device 4, and then the steps S1-S5 are automatically repeated until the set number of experiments is completed.

[0070] S6. Output Results: Generate dynamic curves and statistical reports, and determine the qualification of the bending force of the Litz line.

[0071] This application establishes a highly automated testing process: the contour scanning device 9 acquires the profile cross-sectional data to drive intelligent matching of the central axis, eliminating operational deviations from manual axis selection; the parametric calibration module automatically clears system errors, ensuring the consistency of initial conditions for bending tests; and a flexible switching mechanism between single and multiple test modes meets testing scenarios with different accuracy requirements. This method, through the streamlined integration of mechanical positioning, motion control, and data acquisition, ensures that bending force tests of different batches and specifications of Litz wire operate within a unified benchmark system while minimizing manual intervention, thus improving the reliability of bending force detection.

[0072] In this embodiment, the bending force qualification is determined by comparing the sample type and cross-sectional area with a preset standard library, and an electronic report is output. The sample type is Litz wire conductor material; the specific Litz wire flexibility bending force qualification judgment criteria are shown in Table 1.

[0073]

[0074] The system will automatically determine that the test is unqualified if the following situation occurs during the testing process: After the force data collected by the force testing device 7 is compared with the standard library preset in Table 1 by the control processing system 8, if the maximum value of the curve exceeds the threshold corresponding to the current Litz wire specification (conductor material + cross-sectional area), the output electronic report will display the conclusion of "softness unqualified".

[0075] In step S5, the cutting operation of the wire cutting device 4 includes:

[0076] S5a, Control and processing system 8 retrieves the data of the horizontal width W and vertical height H of the Litz line obtained by scanning in step S2;

[0077] S5b. When W≥H, the wire cutting device 4 is controlled to move along the y-axis to cut the template; when the width-to-height ratio W<H, the wire cutting device 4 is controlled to move along the z-axis to cut the template.

[0078] S5c, The remaining segment of the Litz wire after cutting and retaining it on the fixed clamping assembly 3 is directly used as the fixed end of the new template wire.

[0079] When cutting the template after the bending test has been completed, the movement direction of the wire cutting device 4 is dynamically controlled by the cross-sectional scanning data based on the contour scanning device 9. When the width value of the Litz wire cross-section is detected to be greater than or equal to the height value, horizontal shearing is driven; when the width value of the Litz wire cross-section is detected to be less than the height value, vertical shearing is driven. This reduces the possibility of cross-sectional crushing distortion at the cut point of the Litz wire during cutting, thereby avoiding detection distortion of the next template.

[0080] Reference Figure 1 In step S5, under the multiple experiment mode, the control processing system 8 executes automatically:

[0081] S51. Generate a real-time force-time curve after each bending test is completed;

[0082] S52. After accumulating the set number of experiments, display all single experiment curves overlaid on the same coordinate system;

[0083] S53. Calculate the curve overlap rate based on formula (1):

[0084] Formula (1)

[0085] in, This represents the real-time force value in the nth experiment. This is the average force value from multiple experiments;

[0086] The overlap ratio η is used as an indicator to evaluate the uniformity of the softness of the Litz line.

[0087] Through repeated experiments, the overlap rate of multiple experimental curves was quantified as a mathematical representation of the uniformity of the measured Litz wire's flexibility. When the force curves from multiple experiments showed a high degree of agreement in the overlapping coordinate system (η→100%), it indicated that the conductor lattice slip characteristics were highly consistent across the entire length of the Litz wire. Conversely, a low overlap rate directly reflects the fluctuating defects in the Litz wire material. This technology overcomes the limitations of traditional extreme value statistics, providing a traceable basis for uniformity judgment in production quality control through the synergistic output of visualized graphs and normalized indicators.

[0088] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A measuring instrument for measuring the bending force of a large-scale Litz wire, characterized by, The utility model relates to a kind of automatic wire bending device, including: Detection platform (1); Automatic wire feeding device (2) for driving litz wire along x-axis direction feed; Center shaft assembly (5) is arranged on the detection platform (1), for fixing sample line bending center position; Fixed clamping assembly (3) is arranged on one side of the center shaft assembly (5), for clamping one end of sample line; Bending assembly (6) is arranged on the other side of the center shaft assembly (5), for driving the other end of sample line around bending center bending; Wire cutting device (4) is arranged between fixed clamping assembly (3) and center shaft assembly (5), for cutting litz wire into several sample lines; Force detection device (7) for real-time online detection of sample line stress data in bending process; Control processing system (8) is signal connected with the bending assembly (6) and force detection device (7), for controlling bending movement and processing stress data; The center shaft assembly (5) includes rotary table frame (51) and a plurality of different diameter center shaft bodies (52) arranged on the rotary table frame (51), each center shaft body (52) is arranged along z-axis direction, the rotary table frame (51) is arranged below the table top of detection platform (1), the rotary table frame (51) is provided with lifting drive device (53) for driving each center shaft body (52) to lift along z-axis direction, the detection platform (1) is provided with moving drive device (12) for driving rotary table frame (51) to move along y-axis direction, the detection platform (1) is provided with the avoidance hole (11) that can be used for the center shaft body (52) to pass through table top, the avoidance hole (11) is long hole and its length direction is parallel with y-axis direction; The detection platform (1) is provided with profile scanning device (9) for identifying sample line cross section geometric feature, the profile scanning device (9) and rotary table frame (51) are signal connected with control processing system (8) respectively; The fixed clamping assembly (3) includes first L-shaped supporting plate (31) and clamping plate (32) arranged on one side of first L-shaped supporting plate (31), the first L-shaped supporting plate (31) is fixed on the detection platform (1), and the clamping plate (32) is used to abut one end of the sample line on the side plate of the first L-shaped supporting plate (31); The bending assembly (6) includes arc-shaped sliding rail (61) and second L-shaped supporting plate (62), the arc-shaped sliding rail (61) is arranged below the table top of the detection platform (1), the electric sliding table of the arc-shaped sliding rail (61) is provided with extension piece (63), the table top of the detection platform (1) is provided with arc-shaped groove (13) that can be used for extension piece (63) to pass through and movement avoidance, and the second L-shaped supporting plate (62) is connected with extension piece (63); When the second L-shaped supporting plate (62) is in initial position, the bottom plate of the second L-shaped supporting plate (62) supports the lower end of the sample line, and the opening thereof is arranged towards the sample line; The force detection device (7) is arranged on the side plate of the second L-shaped supporting plate (62), and the detection end of the force detection device (7) is arranged towards the sample line;The arc-shaped sliding rail (61) is signal connected with control processing system (8), and the control processing system (8) is signal connected with operation interface (81) and display interface (82).

2. The detection instrument for measuring the bending force of a large-scale Litz wire according to claim 1, characterized in that: The upper end of the central shaft body (52) is provided with a threaded segment (521), the threaded segment (521) is threadedly connected with a pressing cap (522), the lower end of the pressing cap (522) is provided with a gasket (523), the bottom plate of the first L-shaped supporting plate (31) is provided with a first pressure sensor (311), and the first pressure sensor (311) is signal connected with an alarm module.

3. The instrument for measuring the bending force of a large-scale Litz wire according to claim 1, characterized in that: The automatic wire feeding device (2) comprises a plurality of driving wheels (21) rotatably arranged on a detection table (1), the driving wheels (21) are arranged along the x-axis direction, the detection table (1) is provided with a pressing wheel (22) for pressing the litz wire on the driving wheel (21), and the driving wheel (21) is signal connected with a control processing system (8).

4. A detection method using the detection instrument according to any one of claims 1 to 3, characterized by, The method comprises the following detection steps: S1, fixing the sample line: feeding the litz wire through the automatic wire feeding device (2), and clamping the sample line through the fixing and clamping assembly (3) after the sample line reaches the specified position; S2, calling the central shaft body (52): automatically detecting the cross-sectional shape and size of the sample line through the contour scanning device (9), and transmitting the detection result to the control processing system (8); the control processing system (8) selects the corresponding central shaft body (52) according to the preset range and controls the rotating disc holder (51) to execute the positioning; S3, accurately positioning the central shaft body (52): lifting the target central shaft body (52) to the working position, and making the target central shaft body (52) abut against the bending center of the sample line; S4, inputting parameters and calibration: setting the experimental parameters through the operation interface (81) and executing the zero calibration, the experimental parameters including the sample type, the bending motion angular velocity and the experimental times; S5, bending test: controlling the bending assembly (6) to drive the sample line to bend around the central shaft at the set angular velocity, the force detection device (7) collects the force data in real time, and the control processing system (8) synchronously records the angular displacement and time data; If it is a multiple experiment, the sample line which has completed the test is cut off by the cutting device (4), and then the steps S1-S5 are automatically cycled until the set experimental times are completed; S6, result output: generating a dynamic curve and a statistical report and determining the bending force of the litz wire.

5. The detection method according to claim 4, characterized in that, In the step S5, in the multiple experiment mode, the control processing system (8) automatically executes: S51, generating a real-time force-time curve after completing a bending test; S52, after completing the set experimental times, all single experiment curves are displayed in the same coordinate system; S53, calculating the curve overlap rate based on formula (1): ; Equation (1) wherein, is the real-time force value of the nth experiment, is the average force value of multiple experiments; The overlap rate η is used as an index for evaluating the uniformity of the litz wire softness.

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