Coating defect detection device, coating defect detection method, and manufacturing method of rotating electric machine

Abstract

The construction is provided with: a traveling mechanism that travels the covered conductor to form a traveling path (Wr); a discharge detection electrode (5) that is arranged opposite the covered conductor and is connected to an alternating current power source (6) that applies an alternating current voltage, the electrode length (L) being set to a value or more than the product of the traveling speed (Sr) of the covered conductor and the period of one cycle of the alternating current voltage; a signal detector (7) that detects discharge generated between the discharge detection electrode (5) and the covered conductor; a measuring device (23) that measures the detection interval (t) of the discharge signal (Sa) detected by the signal detector (7); and a determination section (25) that determines whether or not the covered conductor has a covering defect (92d) based on the relationship between the detection interval (t) and the time calculated from the applied alternating current frequency (f).

Description

Technical Field

[0001] This application relates to a device for detecting coating defects, a method for detecting coating defects, and a method for manufacturing a rotating electric motor. Background Technology

[0002] In the stator of rotating electrical machines such as motors and generators, coils are used. These coils are wound with a coated conductor called an electromagnetic wire, which is made by covering a conductor such as copper or aluminum with an organic insulating film. When a pinhole or damage occurs in the coating of the electromagnetic wire, an abnormal current flows through the short circuit between adjacent electromagnetic wires or between the electromagnetic wire and the stator core during the operation of the rotating electrical machine. The coil is abnormally heated, leading to burnout.

[0003] Therefore, the following inspection method has been proposed: two electrodes are arranged on the travel line of the electromagnetic wire, a detection voltage for pinhole detection is applied to one electrode, and a high voltage of several kV, which is several times the detection voltage, is applied to the other electrode, thereby improving the reliability of the detection (see, for example, Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2014-182053 (paragraphs 0018-0033) Figure 1 ) Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Applying high voltage to the electromagnetic wire increases the detection frequency of pinholes, leading to improved reliability. However, excessively high voltage can generate spark discharges that damage the normal coating and potentially harm the item being inspected.

[0009] This application discloses a technology for solving the above-mentioned problems, the purpose of which is to enable highly reliable defect detection without damaging the covered wires of the inspected product.

[0010] Methods for solving problems

[0011] The coated conductor defect detection device disclosed in the present application is characterized by including: a travel path forming mechanism that forms a travel path by causing a coated conductor to travel; a discharge detection electrode that is disposed opposite the coated conductor and is connected to an alternating-current power source that applies an alternating-current voltage, and that is set to a value or more than a value obtained by multiplying a travel speed of the coated conductor by a period of 1 cycle of the alternating-current voltage along a length of the travel path; a discharge detector that detects discharge generated between the discharge detection electrode and the coated conductor; a measurement device that measures a detection interval of a discharge signal detected by the discharge detector; and a determination section that determines whether or not the coated conductor has a coated conductor defect based on a relationship between the detection interval and a time calculated based on an applied alternating-current frequency.

[0012] The coated conductor defect detection method disclosed in the present application is characterized by including: a travel path forming step of forming a travel path by causing a coated conductor to travel; a discharge detection step of applying an alternating-current voltage of a frequency shorter than a value obtained by dividing a length of the discharge detection electrode along the travel path by a travel speed of the coated conductor to a discharge detection electrode disposed opposite the coated conductor, and detecting discharge generated between the discharge detection electrode and the coated conductor; a measurement step of measuring a detection interval of the detected discharge signal; and a determination step of determining whether or not the coated conductor has a coated conductor defect based on a relationship between the detection interval and a time calculated based on the applied frequency.

[0013] Effects of Invention

[0014] According to the coated conductor defect detection device or the coated conductor defect detection method disclosed in the present application, it is determined whether or not there is a coated conductor defect based on a detection interval of a discharge signal, and thus, it is possible to perform defect detection with high reliability without damaging the coated conductor as an inspection target. BRIEF DESCRIPTION OF DRAWINGS

[0015] [ Figure 1 ] is a schematic view for explaining a structure of the coated conductor defect detection device of Embodiment 1.

[0016] [ Figure 2 ] is a view showing an example of a coiled wire feeding machine and a coiled wire winding machine that form the travel path forming mechanism in the coated conductor defect detection device of Embodiment 1.

[0017] [ Figure 3 ] is a perspective view showing an example of a structure of an electromagnetic wire as an inspection target in the coated conductor defect detection device or the detection method of Embodiment 1.

[0018] [ Figure 4FIG. 1 is a perspective view showing the configuration of a discharge detection electrode of a coating defect detection apparatus according to Embodiment 1.

[0019] [ Figure 5 ] is a schematic view showing the electrical connection state of an inspection object, a discharge detection electrode, and a signal detector in the coating defect detection apparatus according to Embodiment 1.

[0020] [ Figure 6 ] is an equivalent circuit diagram showing the electrical connection state of an inspection object, a discharge detection electrode, and a signal detector in the coating defect detection apparatus according to Embodiment 1.

[0021] [ Figure 7 ] Figure 7 A and Figure 7 B are waveform charts each showing the relationship between a discharge signal detected by two discharge detection electrodes and an applied voltage waveform in the coating defect detection apparatus according to Embodiment 1.

[0022] [ Figure 8 ] Figure 8 A and Figure 8 B are waveform charts each showing a measurement example in which the detection interval is different in the coating defect detection apparatus according to Embodiment 1.

[0023] [ Figure 9 ] is a flowchart for explaining the operation of the coating defect detection apparatus according to Embodiment 1 or a coating defect detection method.

[0024] [ Figure 10 ] is a block diagram showing a configuration example of a part of the coating defect detection apparatus according to Embodiment 1 that performs an operation process.

[0025] [ Figure 11 ] is a schematic view for explaining the configuration of a coating defect detection apparatus according to Embodiment 2.

[0026] [ Figure 12 ] is a schematic view for explaining the configuration of a coating defect detection apparatus according to a second example of Embodiment 2.

[0027] [ Figure 13 ] is a schematic view for explaining the configuration of a coating defect detection apparatus according to Embodiment 3.

[0028] [ Figure 14 ] is a waveform chart showing the concept of a factor that reduces the measurement accuracy of a detection interval in the coating defect detection apparatus according to Embodiment 3.

[0029] [ Figure 15 ] is a schematic view for explaining the configuration of a coating defect detection apparatus according to Embodiment 4.

[0030] [ Figure 16FIG. 1 is a diagram showing an example of a screen display of a sampling result of a discharge signal waveform in the coating defect detection apparatus of Embodiment 1.

[0031] [ Figure 17 ] is a schematic diagram for explaining the structure of the coating defect detection apparatus of Embodiment 5.

[0032] [ Figure 18 ] is a diagram showing an example of a screen display of a sampling result of an AC voltage waveform applied to a discharge detection electrode and a discharge signal waveform in the coating defect detection apparatus of Embodiment 5.

[0033] [ Figure 19 ] Figure 19 A and Figure 19 B are each a schematic diagram of the coating defect detection apparatus and the wound portion of the stator core, respectively, for explaining a combination of the coating defect detection method and the wire winding process of the stator core as the manufacturing method of the rotating electric machine of Embodiment 6.

[0034] [ Figure 20 ] is a flowchart for explaining the manufacturing method of the rotating electric machine of Embodiment 6.

[0035] [ Figure 21 ] is a front view showing a main structure portion of the structure of the rotating electric machine produced by the manufacturing method of the rotating electric machine of Embodiment 6.

[0036] [ Figure 22 ] is a waveform chart showing a discharge signal waveform before and after signal processing for explaining the first signal processing of the discharge signal in the coating defect detection apparatus or the detection defect detection method of Embodiment 1.

[0037] [ Figure 23 ] is a waveform chart showing a discharge signal waveform before and after signal processing for explaining the second signal processing of the discharge signal in the coating defect detection apparatus or the detection defect detection method of Embodiment 1.

[0038] [ Figure 24 ] is a waveform chart showing a discharge signal waveform before and after signal processing for explaining the third signal processing of the discharge signal in the coating defect detection apparatus or the detection defect detection method of Embodiment 1. DETAILED DESCRIPTION

[0039] Embodiment 1

[0040] Figures 1-9 the structure and the operation of the coating defect detection apparatus for explaining Embodiment 1, Figure 1 is a schematic diagram showing the correlation between the traveling path of the electromagnetic wire as the inspection object and the structure of the coating defect detection apparatus, Figure 2is a diagram showing an example of a feeding machine and a winding machine as an electromagnetic wire that functions as a travel path forming mechanism that forms a travel path, Figure 3 is a perspective view of the vicinity of the end portion showing an example of the configuration of the electromagnetic wire that is an inspection object, Figure 4 is a perspective view showing the configuration of a discharge detection electrode that constitutes a coating defect detection device.

[0041] Furthermore, Figure 5 is a schematic diagram showing the electrical connection state in the inspection of the electromagnetic wire that is an inspection object, the discharge detection electrode, and the signal detector, Figure 6 is an equivalent circuit diagram showing the electrical connection state in the inspection of the electromagnetic wire that is an inspection object, the discharge detection electrode, and the signal detector.

[0042] Furthermore, Figure 7 A and Figure 7 B are waveform diagrams showing the relationship between the discharge signal detected by the first discharge detection electrode and the second discharge detection electrode, respectively, and the applied voltage waveform applied at different voltage frequencies, Figure 8 A and Figure 8 B are waveform diagrams showing measurement examples in which the detection interval t of the discharge signal detected by the discharge detection electrode is different, respectively, Figure 9 is a flowchart for explaining the operation of the coating defect detection device or the coating defect detection method. Hereinafter, Embodiment 1 will be described in detail with reference to the drawings. In addition, in the drawings hereinafter, the same or equivalent parts are denoted by the same reference numerals, and the description thereof will be omitted.

[0043] As Figure 1 shown, the coating defect detection device 1 of the electromagnetic wire 9 (coated wire) of the present application detects a coating defect 92d Figure 5 ) of the electromagnetic wire 9 before winding, is configured to form a travel path Wr, and is capable of inspecting the electromagnetic wire 9 in travel. A spool 9bf that feeds the electromagnetic wire 9 and a spool 9br that winds the electromagnetic wire 9 are provided before and after the travel path Wr, and further, a feeding machine 3 and a winding machine 4 are provided to the spool 9bf that feeds the electromagnetic wire 9 and the spool 9br that winds the electromagnetic wire 9, respectively.

[0044] The feeding machine 3 and the winding machine 4 are configured to adjust the travel speed Sr of the electromagnetic wire 9, and function as a travel path forming mechanism that forms a travel path Wr in which the electromagnetic wire 9 travels at a constant speed. In addition, the feeding machine 3 and the winding machine 4 can apply various structures, but, for example, as Figure 2 shown, can be configured by a turret 3T and a turret 4T.

[0045] As Figure 3As shown, the electromagnetic wire 9 is composed of a wire core 91 and a coating film 92 covering the wire core 91, and the electromagnetic wire 9 as an inspection object has the coating film 92 peeled off at the end portion so that the wire core 91 is grounded. Further, two discharge detection electrodes 5 (first discharge detection electrode 51 and second discharge detection electrode 52) each configured in a manner of surrounding the electromagnetic wire 9 are arranged in the traveling path Wr of the electromagnetic wire 9.

[0046] Further, an alternating current power source 6 is provided, which is connected to the discharge detection electrodes 5 respectively, and applies a lower voltage of a corona discharge region, for example, an alternating voltage of less than 1 kV, at a predetermined frequency f. For example, the first discharge detection electrode 51 is connected to a first alternating current power source 61 applying an alternating voltage at a frequency fl (= 60 Hz), and the second discharge detection electrode 52 is connected to a second alternating current power source 62 applying an alternating voltage at a frequency f2 (= 120 Hz) which is double the frequency. Note that, in the present embodiment, the frequency fl and the frequency f2 are set to different values, but are not limited thereto, and can be the same value.

[0047] Further, a signal detector 7 (first signal detector 71 and second signal detector 72) is provided, which is connected to the discharge detection electrodes 5 respectively, and detects an electric signal from the discharge detection electrodes 5 to which the alternating voltage is applied. Further, a control device 2 is provided, which controls the coating defect detection operation in the coating defect detection device 1, and detects a coating defect 92d of the electromagnetic wire 9 based on the signal detected by the signal detector 7. Figure 5 ).

[0048] In the control device 2, an A / D converter 21 which digitizes an analog signal detected by the signal detector 7, a storage device 22 which stores the data after A / D conversion, and a measurement device 23 which measures a detection interval t of a discharge signal Sa based on the obtained data are provided. Further, a time difference calculation section 24 which performs time difference processing on the measured detection interval t based on the position of the discharge detection electrode 5, and a determination section 25 which determines the presence or absence of a coating defect 92d based on the relationship between the detection interval t after the time difference processing and the frequency f are provided. Figure 7 ). Figure 8 ).

[0049] The other pole of each of the alternating current power sources 6 is grounded in the same manner as the wire core 91. The electrode length L of each of the discharge detection electrodes 5 in the wire traveling direction is determined based on the traveling speed Sr of the electromagnetic wire 9 and a time τ which is set to be longer than one cycle of the alternating voltage applied to each of the discharge detection electrodes 5, as shown in Expression (1).

[0050] L = Sr x τ... (1)

[0051] For example, if the traveling speed Sr is set to 1000 (mm / sec) and the time τ is set to a time of 1 cycle or more under an alternating voltage of a frequency f (60 Hz) (= 1 / 60 (sec)), the electrode length L of the discharge detection electrode 5 becomes 16.7 mm or more according to Equation (2).

[0052] L ≥ 1000 x (1 / 60) = 16.7... (2)

[0053] In addition, as the electrode length L, the electrode length LI of the first discharge detection electrode 51 and the electrode length L2 of the second discharge detection electrode 52 can also be set to different lengths according to Equation (2), respectively. However, in the case of being aligned to the same length, the electrode length L calculated for the discharge detection electrode 5 to which the voltage of the lowest frequency f is applied can be used.

[0054] It is preferable that the discharge detection electrode 5 be formed in contact with the entire circumference of the electromagnetic wire 9 or be opposed at a certain range of distance, as shown in FIG. 1, or can be formed in a cylindrical shape. In this case, the axis direction of the cylinder is made to coincide with the traveling direction of the electromagnetic wire 9, and the length of the axis direction (the electrode length L) is determined according to the traveling speed Sr and the frequency f according to Equation (1). In addition, the discharge detection electrode 5 can be formed of a metal material such as copper, aluminum, iron, or the like, or can be formed of an electrically conductive rubber or a resin material in which a metal material such as aluminum is continuously vapor-deposited from the inner surface 5fi to the connection site with the alternating power source 6. Figure 4 ei In addition, the inner diameter D of the cylinder can be formed in contact with the outer diameter of the electromagnetic wire 9, and can be formed to have a margin of 10 μm or more and 100 μm or less in order to avoid friction of the coating film 92 due to the contact.

[0055]

[0056] As shown in FIG. 2, a coupling capacitor 7c, a detection resistor 7r, and a voltage measurer 7s that measures the voltage of the detection resistor 7r are provided in the signal detector 7. Therefore, when the electromagnetic wire 9 that is the inspection object passes through the discharge detection electrode 5 described above, the alternating power source 6 applies an alternating voltage to the coating film 92, the coupling capacitor 7c, and the detection resistor 7r that are connected in parallel to the coating film 92. In the drawing, the coating defect 92d is a pinhole or a damage that is generated in the coating film 92. Figure 5 When this state is expressed by an equivalent circuit, as shown in FIG. 3, the voltage of the detection resistor 7r is measured by the voltage measurer 7s.

[0057] Figure 6 ​​​As shown in the figure, the electrostatic capacitance Cd for the portion with coating defect 92d and the electrostatic capacitance Cp connected in series with the portion with coating defect 92d are connected in parallel to the electrostatic capacitance Cn of the normal portion with coating 92. When a discharge occurs between the core 91 and the discharge detection electrode 5, the generated discharge charge is released to the grounding point through a closed circuit consisting of electrostatic capacitance Cd, electrostatic capacitance Cp, coupling capacitor 7c, and detection resistor 7r.

[0058] When a discharge occurs between the core 91 and the discharge detection electrode 5, the applied AC voltage changes drastically. The voltage measuring device 7s detects this change in AC voltage as the voltage value generated across the detection resistor 7r. Furthermore, when no discharge charge q flows through the detection resistor 7r, no voltage is generated across the detection resistor 7r; however, when discharge charge q flows through it, a voltage ΔV is detected according to equation (3).

[0059] ΔV=Rd×q…(3)

[0060] Additionally, Rd is the impedance of the sensing resistor 7r.

[0061] When the electromagnetic wire 9 with the covering defect 92d is traveled, and an AC voltage with voltage waveform Sp is applied to the discharge detection electrode 5, discharge is detected in the first discharge detection electrode 51. Figure 7 The discharge signal Sa is shown in Figure A. Here, it should be noted that, in the presence of the encapsulation defect 92d, the discharge signal Sa maintains a certain phase angle relative to the voltage waveform Sp, with the zero-crossing point as a reference, and is detected at time intervals equivalent to half a cycle for the positive and negative sides, being detected twice within one cycle. Furthermore, in the second discharge detection electrode 52 with different frequencies f, such as... Figure 7 As shown in B, the discharge signal Sa also maintains a certain phase angle relative to the voltage waveform Sp, with the zero-crossing point as the reference, and is detected at a time interval equivalent to half a cycle of the positive and negative sides, and is detected twice in one cycle.

[0062] In this example, the ratio (=f2 / f1)n of the voltage frequency f2 applied to the second discharge detection electrode 52 to the voltage frequency f1 applied to the first discharge detection electrode 51 is shown to be 2. Therefore, the detection interval t2 measured for the second discharge detection electrode 52 becomes half of the detection interval t1 measured for the first discharge detection electrode 51. This relationship depends on the multiple ratio of the voltage frequencies applied to the two electrodes.

[0063] That is, it was found that when the ratio of the voltage frequency f (=f2 / f1) is n, the detection interval t2 measured for the second discharge detection electrode 52 for a certain coating defect 92d becomes 1 / n of the detection interval t1 measured for the first discharge detection electrode 51. Furthermore, it was found that this relationship is observed regardless of the traveling speed Sr.

[0064] Therefore, in the plurality of discharge detection electrodes 5, the applied voltage frequency applied to the second and subsequent discharge detection electrodes 5 is set to, for example, 2 times, 3 times,..., n times, with respect to the applied voltage frequency f1 applied to the first electrode. Also, in a case where the detection interval t measured for each discharge detection electrode 5 becomes 1 / 2, 1 / 3,..., 1 / n, with respect to the detection interval t1 measured for the first electrode, it can be determined that the discharge signals Sa are from the same coating defect 92d.

[0065] Therefore, with respect to a noise discharge due to a measurement environment such as instability of the gap distance between the discharge detection electrode 5 and the electromagnetic wire 9 or a slight variation in the ground potential, the discharge due to the coating defect 92d of the electromagnetic wire 9 (discharge signal Sa) can be reliably distinguished, and it is possible to determine the presence or absence of the coating defect 92d. This is because the discharge signal Sa from the coating defect 92d is generated in such a manner that the phase angle is maintained with respect to the applied voltage waveform Sp.

[0066] In addition, in Figure 7 A, Figure 7 B, in order to clarify the relationship between the detection interval t and the phase angle of the applied voltage waveform Sp, a discharge generated near the zero crossing is exemplified, but the generation phase angle of the discharge is not limited thereto. As long as the detection is performed at the same phase angle position with respect to the zero crossing, even if it is separated from the zero crossing, the detection interval t can obtain the same detection interval t as that observed on the zero crossing.

[0067] Therefore, as Figure 1 described in A, with respect to the discharge signals Sa detected by each discharge detection electrode 5 two or more times, the signal detector 7 converts into a discharge signal waveform, and after A / D conversion at a certain sampling frequency by the A / D converter 21, it is saved in the storage device 22. The measurement device 23 measures the detection interval t of each of the discharge detection electrodes 5 based on the saved data.

[0068] It is possible to Figure 8 A to the interval of the maximum peak values Px of each of the discharge signals Sa from each other, Figure 8The detection interval t is measured using various methods, such as the interval between the initial peak values ​​Ph of each discharge signal Sa shown in B and their average values. Furthermore, sometimes multiple detection intervals t are measured by arranging more than three discharge signals; however, in this case, the average value can also be used, and any detection interval t can be used as a representative value, except for the detection interval t shown with values ​​offset from others.

[0069] Signal Processing

[0070] However, due to the vibration of the electromagnetic wire 9 during its travel, and the differences in the surface shape and depth of the coating defect 92d of the electromagnetic wire 9, Figure 8 The maximum peak value Px of each discharge signal Sa shown in A sometimes varies, and it is sometimes difficult to find the maximum peak value Px of each discharge signal Sa. Therefore, a method for signal waveform processing that makes it easy to find the maximum peak value Px of each discharge signal Sa under such circumstances will be explained.

[0071] Figures 22-24 These sections are used to describe the first to third signal processing steps, respectively. The upper section shows the signal waveform before processing, and the lower section shows the signal waveform after processing. In the first signal processing, such as... Figure 22 As shown, the absolute value of the discharge signal Sa is compared with the threshold Th. The portion of the discharge signal Sa whose absolute value is above the threshold Th is set to "1", and the portion whose absolute value is below the threshold Th is set to "0", thus converting the discharge signal Sa into signal Sa1. In this way, by using signal Sa1, which is the result of signal processing of the original discharge signal Sa, the maximum peak value Px can be easily found, and the detection interval t can be accurately measured.

[0072] In addition, Figure 8 A and Figure 8 In section B, an ideal example of the discharge signal Sa for the coating defect 92d of the electromagnetic wire 9 is shown. However, in actual discharge signals Sa, it is not possible to use such a method. Figure 8 As explained in B, while the initial peak value Ph can be explicitly determined, calculating the detection interval t is sometimes difficult. Therefore, as a second signal processing step, such as... Figure 23 As shown, the discharge signal Sa is converted into a smoothed signal Sa2, for example, by applying a low-pass filter. Thus, by using the processed signal Sa2, the initial peak Ph can be easily identified, and the detection interval t can be accurately measured.

[0073] Alternatively, due to the measurement environment of electromagnetic line 9, such as Figure 24As shown, noise such as noise Snl, noise Sn2, and the like can be superimposed on the discharge signal Sa. In the third signal processing, high-pass filtering is applied to the discharge signal Sa on which noise such as noise Snl, noise Sn2, and the like is superimposed, and the signal Sa3 from which the noise is removed is converted. Then, if the first signal processing or the second signal processing is used for the signal Sa3, the detection interval t can be measured more accurately.

[0074] On the other hand, it is necessary to make the measured detection interval t of each of the discharge detection electrodes 5 correspond to the coating defect 92d corresponding to the same position of the electromagnetic wire 9 in the traveling direction. Therefore, the time difference calculation section 24 performs time difference calculation processing of acquiring the time (measurement time) so that the positions of the discharge detection electrodes 5 corresponding to the measured detection interval t are aligned on the electromagnetic wire 9.

[0075] The determination section 25 confirms whether the ratio of the detection intervals t of the discharge signals Sa detected by the first discharge detection electrode 51 and the second discharge detection electrode 52 corresponding to the same position of the electromagnetic wire 9 in the traveling direction becomes the reciprocal multiple of the ratio n of the applied voltages. Then, in a case where it is confirmed that the ratio of the detection intervals t is in a reciprocal relationship within a range set in advance (for example, within a range in which an allowable error is specified in percentage positive and negative), it is determined that there is a pinhole or a damage or the like coating defect 92d. On the other hand, if the ratio of the detection intervals t does not enter the set range, it is determined that there is no coating defect 92d.

[0076] Reference Figure 9 The flowchart of FIG. 1 will be described again as a detection procedure operation of the coating defect 92d in the coating defect detection device 1 described above, that is, a coating defect detection method.

[0077] The electromagnetic wire 9 is erected from the reel 9bf toward the reel 9br by each of the discharge detection electrodes 5 in such a manner that it travels in the traveling path Wr by the winding of the winder 4 (step S100). In this state, an alternating current voltage is applied to each of the discharge detection electrodes 5 at a set frequency f, and the measurement of the discharge signal Sa is performed (step S110).

[0078] When the signal such as the discharge signal Sa is detected (step S120: Yes), the detection interval t of each of the discharge detection electrodes 5 is measured, and the time difference processing is performed (step S130). Then, the detection interval t of each of the discharge detection electrodes 5 is analyzed (step S140), and it is determined whether it is in a reciprocal relationship of n using the ratio n of the frequency f described above (step S150).

[0079] When in the assumed range is in the inverse relationship (step S150: Yes), it is determined that there is a coating defect (step S200), for example, by the time difference calculation section 24 to calculate the defect position and notify the calculated position (step S210) and the like corresponding processing. On the other hand, when in the assumed range is not in the inverse relationship (step S150: No), it is determined that there is no coating defect (step S300), end. In addition, not particularly noted on the flow, but, continue to perform these procedures until, for example, the electromagnetic wire 9 wound on the reel 9bf disappear can be.

[0080] At this time, for example, when the defect is found in 2 in the full length, it can also be notified in the presence of defects in the 253.25 m portion and the 781.74 m portion from the start of winding, and the like. In addition, if the data of the discharge signal waveform and the detection interval t in the case where it is determined that there is no coating defect 92d is sequentially deleted from the storage device 22, the storage area of the storage device 22 can be saved and effectively utilized.

[0081] In addition, in each of Embodiment 1 and subsequent embodiments, the following example is shown: In order to improve the separation ability (S / N ratio) from the noise, it is determined whether there is a coating defect 92d using the data of the detection interval t from a plurality of discharge detection electrodes 5, but is not limited thereto. For example, it can also be used that the discharge signal Sa appears every half cycle with a certain phase angle with respect to the zero crossing, and it is determined whether there is a coating defect 92d depending on whether the interval of two discharge signals Sa coincides with half a cycle.

[0082] Further, in the case where the same frequency f is set to a plurality of discharge detection electrodes 5, one discharge detection electrode 5 capable of measuring the electrode length L of three or more discharge signals Sa can also be provided, and it is determined whether there is a coating defect 92d depending on whether two or more intervals measured based on three or more signals coincide. However, the discharge detection electrodes 5 are divided and connected to different alternating current power sources 6, whereby it has the advantage that it can separate the noise unique to the alternating current power source 6. Similarly, by setting different frequencies to a plurality of discharge detection electrodes 5, it has the advantage that the noise resistance is stronger.

[0083] Further, with respect to the discharge signal Sa, using the phenomenon that the positive and negative are alternately reversed, the determination section 25 can also select the signal in which the polarity is alternately reversed as the determination object of the defect detection, whereby the noise removal efficiency is further improved. In addition, instead of selecting the signal in which the positive and negative are reversed, a signal with weak intensity can also be applied to the determination object, whereby the capture rate of the coating defect 92d can also be improved.

[0084] In addition, in each of Embodiment 1 and the following embodiments, in a case where the execution portion of the operation processing is configured by using software of a microcomputer, as shown in Figure 10 The control device 2 can be configured by one microcomputer 200 having a processor 201 and a storage device 202, as shown in

[0085] Embodiment 2

[0086] In Embodiment 1 described above, an example in which a discharge detection electrode for detecting discharge by applying an alternating voltage is arranged in the traveling path of the electromagnetic wire is described. In Embodiment 2, an example in which, with respect to Embodiment 1, a charge-removing electrode for removing charge from the charged electromagnetic wire is additionally arranged in the traveling path is described.

[0087] Figure 11 is a schematic view showing the correlation between the structure of the coating defect detection device relating to Embodiment 2 and the traveling path of the electromagnetic wire as an inspection object, Figure 12 is a schematic view showing the correlation between the structure of the coating defect detection device relating to the second example of the embodiment and the traveling path of the electromagnetic wire as an inspection object. In addition, the structure and the operation other than the charge-removing electrode are the same as those described in Embodiment 1, the description of the same portions is omitted, and the symbols used in Embodiment 1 are referred to. Figures 2-10 .

[0088] The coating 92 of the electromagnetic wire 9 can be positively or negatively charged due to friction with an unillustrated guide pulley, other structural members, or the like in the traveling path Wr. In this case, a portion of the voltage on the positive side or the negative side to which the alternating voltage is applied is canceled, and thus the discharge signal Sa from the coating defect 92d under the positive side phase or the negative side phase becomes unstable. As a result, the measured value of the detection interval t deviates, and as a result, the coating defect 92d can be overlooked.

[0089] Therefore, in the coating defect detection device 1 of Embodiment 2, as shown in Figure 11As shown, for the discharge detection electrode 5, a grounded electrode 8 is provided on the upstream side of the electromagnetic line's travel path Wr, thereby eliminating the charge on the coating 92. More specifically, a first electrode 81 is provided upstream of the first discharge detection electrode 51, and a second electrode 82 is provided downstream of the first discharge detection electrode 51 and upstream of the second discharge detection electrode 52.

[0090] The first de-energizing electrode 81, located upstream of the first discharge detection electrode 51, de-energizes the charged charge caused by friction between the structural components of the reel 9bf (for delivering the electromagnetic wire 9) and the first first discharge detection electrode 51. Similarly, the second de-energizing electrode 82, located upstream of the second discharge detection electrode 52, de-energizes the charged charge caused by friction between the reel 9bf and the second second discharge detection electrode 52, and de-energizes the charged charge caused by the application of an AC voltage to the first discharge detection electrode 51.

[0091] Second case

[0092] In addition, as a second example, such as Figure 12 As shown, a third de-energizing electrode 83 is provided downstream of the downstream discharge detection electrode 5 (in this example, downstream of the second discharge detection electrode 52). In this case, the charged charge caused by the application of an AC voltage to the downstream discharge detection electrode 5, i.e., the second discharge detection electrode 52, can be de-energized, and the coating defect 92d caused by the discharge of charged charge in the subsequent travel path Wr can be prevented, which is more preferable.

[0093] Implementation Method 3

[0094] In this third embodiment, an example of adding a countermeasure against sudden discharge based on the charged charge countermeasure in the second embodiment will be described. Figure 13 and Figure 14 This is used to illustrate the structure and operation of the coating defect detection device in Embodiment 3. Figure 13 This is a schematic diagram showing the relationship between the structure of the coating defect detection device and the travel path of the electromagnetic wire being inspected. Figure 14 This is a waveform diagram illustrating the concept of factors that reduce the measurement accuracy of the detection interval, which is the target of the countermeasure, in this embodiment. Furthermore, the structure and operation other than the sudden discharge countermeasure are the same as those described in Embodiments 1 and 2; descriptions of identical parts are omitted, and the descriptions used in Embodiment 1 are referenced. Figures 2-10 .

[0095] In defect detection of coated conductors, besides the charged coating described in Implementation Method 2, factors that reduce the measurement accuracy of the detection interval t include, for example... Figure 14As shown, a burst discharge caused by a discharge signal Sa of the same degree of intensity as the discharge signal Sa based on the coating defect 92d can be cited. Such a discharge has no regularity with respect to the applied voltage waveform Sp and is randomly generated. For example, when a noise Sn called spike noise is erroneously measured as a peak of the discharge from the coating defect 92d in the detection interval t, the measured value is deviated.

[0096] As a countermeasure therefor, it is effective to increase the number of the discharge detection electrodes 5. Therefore, in the coating defect detection device 1 of the present embodiment 3, as shown in FIG. 6, a third discharge detection electrode 53 is provided downstream of the third discharge removing electrode 83 shown in the second example of the present embodiment 2. The third discharge detection electrode 53 is also connected with a third alternating current power source 63 and a third signal detector 73 as with the other discharge detection electrodes 5, and a fourth discharge removing electrode 84 is further provided downstream thereof. Figure 13

[0097] Moreover, the frequency f3 of the alternating current voltage applied to the third discharge detection electrode 53 is set to m times the frequency f2 of the alternating current voltage applied to the second discharge detection electrode 52 explained in the present embodiment 1 and the present embodiment 2. Moreover, for example, in the step S150( Figure 9 ) as well, if the detection interval t is the inverse multiple of the frequency multiple ratio in at least two of the three discharge detection electrodes 5, the determination section 25 determines that the coating defect 92d exists.

[0098] That is, with respect to the voltage frequency fl of the first discharge detection electrode 51, the voltage of the frequency f2 of n times is applied to the second discharge detection electrode 52, and the voltage of the frequency f3 of m times the frequency f2, that is, n x m times the frequency fl is applied to the third discharge detection electrode 53. In this case, when the detection interval tl of the first discharge detection electrode 51, the detection interval t2 of the second discharge detection electrode 52, and the detection interval t3 of the third discharge detection electrode 53 are used, with respect to the presence or absence of the coating defect 92d, the following conditions A to D can be used in combination to determine.

[0099] t2≒t1 / n & t3≒t1 / (n x m)... Condition A

[0100] t2≒t1 / n... Condition B

[0101] t3≒t1 / (n x m)... Condition C

[0102] t3≒t2 / m... Condition D

[0103] t2≠t1 / n & t3≠t2 / m & t3≠t1 / (n x m)... Condition X

[0104] ​That is, if either of conditions B and C is satisfied (condition X is not satisfied), it is determined as "Yes" in step S150. Alternatively, the determination condition can be changed in consideration of the priority of noise removal and capture rate, so that it is determined as "Yes" when both of conditions B and C (condition A) are satisfied.

[0105] For example, in a case where the ratio of the detection intervals t is set as a condition, the determination reference of the coating defect 92d in Embodiments 1 and 2 is only condition B. In contrast, as in the present Embodiment 3, by adding only one discharge detection electrode 5, the coating defect 92d can be detected by the combination of conditions B and C, and the detection accuracy and the degree of freedom of the setting of the determination reference are improved.

[0106] In addition, if the discharge detection electrodes 5 are added, the inspection time increases, and the production capacity can be impaired, but the optimum number of discharge detection electrodes can be determined in advance by experiments or the like. Further, of course, the detection intervals t can be determined in accordance with the degree of coincidence between the time of half a cycle calculated on the basis of the frequency f instead of the ratio of the detection intervals t.

[0107] Further, in the present Embodiment 3, an example in which the number of discharge detection electrodes 5 is added with respect to Embodiment 2 using the charge eliminating electrode 8 is shown, but is not limited thereto. For example, the number of discharge detection electrodes 5 can be added with respect to the example of Embodiment 1 in which the coating electrification countermeasure is not described.

[0108] Embodiment 4

[0109] In the above-described Embodiments 1 to 3, the display of the measurement data is not mentioned. In the present Embodiment 4, the structure of displaying the measurement data in a screen is described. Figure 15 and Figure 16 the structure and the operation of the coating defect detection device for explaining Embodiment 4, Figure 15 is a schematic view showing the correlation between the structure of the coating defect detection device and the traveling path of the electromagnetic wire as an inspection object, Figure 16 is a drawing showing an example of a screen display of the sampling results of the measurement results of each discharge detection electrode, that is, the discharge signal waveforms. In addition, the structure and the operation other than the screen display are the same as those described in the above-described Embodiments 1 to 3, the description of the same parts is omitted, and the Figures 2-10 .

[0110] In the coating defect detection device 1 of the present Embodiment 4, as Figure 15As shown, an image display device 2g is provided for displaying measurement data obtained during measurement, and a display data generation unit 26 is provided for generating display data and outputting it to the image display device 2g. The display data generation unit 26 has the following function: when the determination unit 25 determines that there is a discharge from the coating defect 92d, it generates display data so that the image display device 2g displays the measurement data used in the determination.

[0111] Specifically, such as Figure 16 As shown, within the display screen Di of the image display device 2g, a text display Dt is displayed along with the applied voltage frequency f, along with a graphical display Dg showing the latest signal waveform at the time of determination of each discharge detection electrode 5, and the measured detection interval t. With this configuration, the operator can check the detection status of pinholes or damage at any time. Furthermore, it can be confirmed whether the positive and negative signals have been sequentially reversed. Additionally, as a layout of the display screen Di, an example is shown where the screen is divided into intervals for each discharge detection electrode 5 (first interval Di2, second interval Di3, third interval Di3), and the measurement information of each discharge detection electrode 5 is displayed centrally according to each interval; however, this is not the only possible layout.

[0112] Implementation Method 5

[0113] In Embodiment 4 described above, the waveform of the AC voltage applied to the discharge detection electrode was not mentioned. In this Embodiment 5, a structure for acquiring a signal from an AC power source and displaying the waveform of the AC voltage will be described. Figure 17 and Figure 18 This is used to illustrate the structure and operation of the coating defect detection device in Embodiment 5. Figure 17 This is a schematic diagram showing the relationship between the structure of the coating defect detection device and the travel path of the electromagnetic wire being inspected. Figure 18 This is a diagram showing an example of a screen displaying the measurement results of each discharge detection electrode, i.e., the sampling results of the discharge signal waveform.

[0114] Furthermore, the structure and operation other than the AC voltage waveform display are the same as those described in Embodiments 1-3 and 4 above, and the description of the same parts is omitted. The description used in Embodiment 1 is referenced. Figures 2-10 .

[0115] In the coating defect detection device 1 of this embodiment 5, such as Figure 17 As shown, the device is configured to input signals from each AC power source 6 into the control device 2. Furthermore, it adds the following function: after performing A / D conversion on the AC voltage waveform from each AC power source 6 applied to the discharge detection electrode 5 at a certain sampling frequency using the A / D converter 21, it saves the waveform in the storage device 22 and outputs it to the image display device 2g via the display data generation unit 26.

[0116] As for the control of the start of the sampling of the AC voltage waveform, for example, the start of the sampling of the discharge waveform signal of the first discharge signal Sa among the discharge signals Sa detected by the discharge detection electrodes 5 can be started as a trigger. In this case, for example, for the discharge detection electrodes 5 other than the discharge detection electrode 5 that detected the discharge signal Sa, it is sufficient to start the time with the consideration of the travel speed Sr and the time difference corresponding to the arrangement position. Further, as for the control of the stop, it is sufficient to stop after the sampling is continued for the time τ corresponding to one cycle or more of the AC voltage as described in Embodiment 1.

[0117] The AC voltage waveform thus sampled is superimposed and displayed with the discharge signal waveform as described in Embodiment 4. Specifically, as shown in the graphic display Dg, Figure 18 the waveform display Gw representing the applied voltage waveform Sp is displayed together with the discharge signal waveform. If thus configured, the operator can confirm at any time that the signal determined to be the discharge from the covering defect 92d is generated in a manner that the phase angle with respect to the applied voltage waveform Sp is maintained, and the determination is appropriate. At this time, if a scale representing the detection interval t and the length of half a cycle, or a scale representing the size of the reciprocal of the ratio of the detection interval t to the frequency f in the other discharge detection electrodes is displayed, it is possible to visually confirm that the determination is appropriate.

[0118] Embodiment 6

[0119] In this Embodiment 6, a method of manufacturing a rotating electric machine using the covering defect detection apparatus or the detection method described in Embodiments 1 to 5, or a method of manufacturing a rotating electric machine using an electromagnetic wire having no covering defect will be described. Figures 19-21 A manufacturing method of a rotating electric machine for describing Embodiment 6, Figure 19 is a view for describing a combination of a covering defect detection method and a winding process of a stator core, and shows a portion of the covering defect detection apparatus corresponding to Figure 17 A) of Embodiment 5, and Figure 19 is a view showing a winding portion of the stator core (unit core) corresponding to a portion of the winding machine in Figure 19 A), and Figure 17 is a view showing a winding portion of the stator core (unit core) corresponding to a portion of the winding machine in Figure 19 B).

[0120] Further, Figure 20 is a flowchart for describing a manufacturing method of a rotating electric machine, Figure 21 is a view showing a process of Figure 19 and Figure 20This is a front view of the main structural parts of the rotary electric motor manufactured according to the manufacturing method of the rotary electric motor described herein, viewed from the extension line of the rotation axis. Furthermore, in the manufacturing method of the rotary electric motor, the parts corresponding to the inspection devices or inspection methods described in Embodiments 1-5 are identical to those described in Embodiments 1-5, except for the winding machine part; therefore, descriptions of the identical parts are omitted, and the descriptions used in Embodiment 1 are referenced. Figures 2-10 .

[0121] In the manufacturing method of the rotary electric motor in Embodiment 6, such as Figure 19 A, Figure 19 B and Figure 20 As shown, the covering defect detection device 1 or detection method described in Embodiment 1 is incorporated into the winding process of the armature, i.e., the stator 102, of the rotary motor 100 or the linear motor. Additionally, the unit core 102i constituting the unit stator 102t for forming the annular stator 102 is depicted.

[0122] Instead of the winding machine 4 described in embodiments 1 to 5, a winding machine and winding nozzle 9n (not shown) are used, and a unit iron core 102i is used instead of the spool 9br. Moreover, instead of step S100, the electromagnetic wire 9 is made to travel in the travel path Wr by a winding operation in which the electromagnetic wire 9 passes through each discharge detection electrode 5 and is wound from the spool 9bf to the unit iron core 102i via the winding nozzle 9n of the winding machine (not shown) (step S100A).

[0123] In this state, steps S110 to S140 described in embodiments 1 to 5 are executed. When the detection interval t satisfies, for example, conditions A to D described in embodiment 3 (step S150: Yes), it is determined that a coating defect exists (step S200). Here, the travel path length Lw of the electromagnetic wire 9 between the final discharge detection electrode 5 of the discharge signal Sa up to the determination and the wound unit iron core 102i is known. Therefore, for example, the time difference calculation unit 24 calculates the time T = Lw / Sr from the time when the portion where the detected coating defect 92d is located reaches the wound unit iron core 102i based on the pre-input travel speed Sr and travel path length Lw, and inputs it to the measuring device 23.

[0124] The measuring device 23 starts a timer measurement with reference to the time T calculated by the time difference calculation section 24. Thus, the unit core 102i in which the winding operation is in progress at the point in time at which the measuring device 23 completes the measurement is determined and notified (step S210). Further, the unit core 102i determined to have a winding defect (the corresponding product) is ejected so as not to be mixed into the product (step S250). Note that, while the traveling speed Sr sometimes varies depending on the winding position during winding of the coil, the present embodiment is configured to be able to determine the location of the covering defect 92d in accordance with the varying traveling speed Sr.

[0125] On the other hand, the coil 102c is completed for the unit core 102i determined to have no defect, for example, as a unit stator 102t in which eight coils 102c are combined in a circular ring shape to constitute the stator 102, and the process proceeds to the stator assembly process (step S400). That is, the covering defect detection method described in Embodiments 1 to 5 is executed in the winding process of forming the coil 102c, whereby the unit stator 102t in which the coils 102c are combined in the unit core 102i is produced. Then, the unit stator 102t is coaxially arranged with the rotor 101 assembled in the rotor assembly process (step S500) performed in parallel, and the outer periphery is fixed with the frame 103, whereby the rotary electric machine 100 shown in FIG. 1 is formed. Figure 21

[0126] Thus, the unit stator 102t in which the covering defect 92d is contained in the coil 9 is determined not to flow to the subsequent processes, and can be distinguished from the good product by means such as transfer to a conveyor, a pallet, or the like that discharges defective products (step S250). Note that, before the measuring device 23 completes the measurement of the prescribed time, the traveling of the coil 9 can be stopped due to stoppage of the winding machine. However, in this case, the measuring device 23 receives a signal of winding stoppage from the winding machine, and stops the measurement during the period until the winding is restarted, or always receives a signal of winding in progress during winding, and can continue the measurement only while the signal is being received.

[0127] That is, the rotary electric machine 100 can be formed by the stator 102 formed only of the coil 9 that does not contain the covering defect 92d. Further, the defective stator can be reexamined by a known surge voltage application (pulse voltage application) test or the like, and if it is good, it can be incorporated in step S400. Alternatively, if the winding can be unwound and the covering defect 92d can be repaired, it can be incorporated in step S100A after the repair.

[0128] ​Further, in the manufacturing method of the rotating electric machine of Embodiment 6, an example in which the coated wire 9 used in the coil 102c of the stator 102 is checked for the presence or absence of a coating defect 92d is shown, but the present application is not limited thereto. For example, a process of checking the coated wire of the rotor 101 or the like that constitutes an armature for a coating defect can be incorporated.

[0129] As described above, according to the coating defect detection device or the coating defect detection method exemplified in each embodiment of the present application, spark discharge does not occur, a lower voltage (for example, an alternating voltage of less than 1 kV) of a corona discharge region is applied, and the presence or absence of a coating defect 92d is determined by the detection interval t. Therefore, even if a high voltage that damages the coating film 92 is not applied, the discharge signal Sa can be distinguished from noise and the presence or absence of a coating defect 92d can be accurately determined, and thus the detection of a coating defect 92d can be performed with high precision in a non-destructive manner. Furthermore, a rotating electric machine 100 can be formed using a sound coated wire 9.

[0130] Further, the present application describes exemplary embodiments, but the various features, modes, and functions described in the embodiments are not limited to the application of the specific embodiments and can be applied to the embodiments individually or in various combinations. Therefore, countless modifications that are not exemplified are conceivable within the technical scope disclosed in the present specification. For example, cases in which at least one structural element is modified, cases in which at least one structural element is added, or cases in which at least one structural element is omitted are included.

[0131] As described above, according to the coating defect detection device 1 of the present application, a traveling mechanism (the feeder 3, the winder 4) that causes a coated wire (the coated wire 9) to travel to form a traveling path Wr, a discharge detection electrode 5 that is disposed opposite the coated wire and is connected to an alternating power source 6 that applies an alternating voltage, the length (electrode length L) of which is set to a value obtained by multiplying the traveling speed Sr of the coated wire by the period of one cycle of the alternating voltage or more, a discharge detector (the signal detector 7) that detects discharge generated between the discharge detection electrode 5 and the coated wire, a measuring device 23 that measures the detection interval t of the discharge signal Sa detected by the discharge detector, and a determination section 25 that determines whether or not the coated wire has a coating defect 92d based on the relationship between the detection interval t and the time calculated from the applied alternating frequency f. Thus, an alternating voltage of a lower voltage of a corona discharge region is applied, spark discharge does not occur, and the presence or absence of a coating defect 92d can be determined. As a result, defect detection with high reliability can be performed without damaging the coated wire 9 that is the object of inspection.

[0132] At this time, if the determination section 25 determines whether or not the coated conductor has the coating defect 92d based on whether or not the detection interval t corresponds to half of the cycle of the alternating voltage, the influence of noise can be eliminated, and the coating defect 92d can be detected with high accuracy.

[0133] Alternatively, the discharge detection electrode 5 is constituted by a plurality of discharge detection electrodes 5 arranged separately at separate positions along the travel path Wr, and the determination section 25 determines whether or not the coated conductor has the coating defect 92d based on whether or not the ratio of the detection intervals t measured for the plurality of discharge detection electrodes 5 respectively and the ratio of the alternating frequencies f applied to the plurality of discharge detection electrodes 5 respectively are in an inverse relationship, and the influence of noise can be eliminated, and the coating defect 92d can be detected with high accuracy.

[0134] If the destaticizing electrode 8 that removes the electrification of the coated conductor is provided on the upstream side of the discharge detection electrode 5 along the travel path Wr, noise due to electrification can be removed, and the coating defect 92d can be detected with higher accuracy.

[0135] Further, if the determination section 25 sets the positive and negative inversion of the discharge signal Sa (adjacent signals) that becomes the measurement object of the detection interval t as the determination object of whether or not the coated conductor has the coating defect 92d, false determination due to noise can be further suppressed.

[0136] Further, if the determination section 25 performs signal processing (first signal processing) in which the absolute value of the discharge signal Sa is compared with a threshold value Th, and the case where the absolute value of the discharge signal Sa is equal to or greater than the threshold value Th is converted to a first value (for example, 1), and the case where the absolute value of the discharge signal Sa is less than the threshold value Th is converted to a second value (for example, 0), and the determination section 25 calculates the detection interval t based on the signal Sa1 after the signal processing, the detection interval t can be accurately measured.

[0137] Alternatively, if the determination section 25 performs signal processing (second signal processing) in which the discharge signal Sa is smoothed (for example, by a low-pass filter), and calculates the detection interval t based on the signal Sa2 after the signal processing, the detection interval t can be accurately measured.

[0138] Further, if the determination section 25 calculates the detection interval t based on a signal Sa3 to which noise filtering is applied to the discharge signal Sa (for example, high-pass filtering is performed as third signal processing), the detection interval t can be more accurately measured.

[0139] As described above, according to the coating defect detection method of the present application, if configured to include the following steps: a travel path forming step (step S100 / S100A) of causing the coated conductor (electromagnetic wire 9) to travel and form a travel path Wr; a discharge detection step (steps S110-S130) of applying an alternating voltage of a frequency f shorter than a value obtained by dividing a length of the discharge detection electrode 5 along the travel path Wr (electrode length L) by the travel speed Sr of the coated conductor to the discharge detection electrode 5 disposed opposite the coated conductor, detecting a discharge generated between the discharge detection electrode 5 and the coated conductor; a measurement step (step S140) of measuring a detection interval t of the detected discharge signal Sa; and a determination step (steps S150-S200 / S300) of determining whether or not the coated conductor has a coating defect 92d based on a relationship between the detection interval t and a time calculated from the applied alternating frequency f, then an alternating voltage of a lower voltage in the corona discharge region does not generate spark discharge, and it is possible to determine the presence or absence of a coating defect 92d. As a result, it is possible to perform defect detection with high reliability without causing damage to the electromagnetic wire 9 as the inspection target product.

[0140] At this time, if in the determination step (step S150), it is determined whether or not the coated conductor has a coating defect 92d depending on whether or not the detection interval t corresponds to half a cycle of the alternating voltage, then it is possible to exclude the influence of noise and detect the coating defect 92d with high accuracy.

[0141] Alternatively, in the discharge detection step (steps S110-S130), an alternating voltage of a separately set frequency f is applied to each of the discharge detection electrodes 5 composed of a plurality of discharge detection electrodes 5 dispersed at separate positions along the travel path Wr, and in the determination step (step S150), it is determined whether or not the coated conductor has a coating defect 92d depending on whether or not a ratio of the detection intervals t measured for the plurality of discharge detection electrodes 5 and a ratio of the alternating frequencies f applied to the plurality of discharge detection electrodes 5 are in an inverse relationship, and it is also possible to exclude the influence of noise and detect the coating defect 92d with high accuracy.

[0142] Further, if in the determination step (step S150), in the case where the positive and negative of the discharge signal Sa (adjacent signals) that becomes the measurement target of the detection interval t are reversed, it is set as a determination target of whether or not the coated conductor has a coating defect 92d, it is possible to further suppress false determinations due to noise.

[0143] Further, if signal processing (first signal processing) is performed in the determination step (step S150) in which the absolute value of the discharge signal Sa is compared with a threshold value Th, and the case where the absolute value of the discharge signal Sa is equal to or greater than the threshold value Th is converted into a first value (for example, 1), and the case where the absolute value of the discharge signal Sa is less than the threshold value Th is converted into a second value (for example, 0), the detection interval t is calculated from the signal Sa1 on which the signal processing is performed in the determination step (step S150), and thus the detection interval t can be accurately measured.

[0144] Alternatively, if signal processing (second signal processing) is performed in the determination step (step S150) in which the discharge signal Sa is smoothed (for example, by a low-pass filter), the detection interval t is calculated from the signal Sa2 on which the signal processing is performed, and thus the detection interval t can be accurately measured.

[0145] Further, if the detection interval t is calculated from the signal Sa3 on which noise filtering is applied to the discharge signal Sa (for example, high-pass filtering is performed as third signal processing) in the determination step (step S150), the detection interval t can be more accurately measured.

[0146] Further, according to the manufacturing method of the rotating electric machine 100 of the present application, if configured to include a stator assembly step (step S400) of assembling the stator 102, a rotor assembly step (step S500) of assembling the rotor 101, and a total assembly step (step S600) of arranging the stator 102 and the rotor 101 coaxially to assemble the rotating electric machine 100, in any of the stator assembly step and the rotor assembly step, in a coil formation process of winding the covered conductor (electromagnetic wire 9) around the core (unit core 102i), it is determined whether or not there is a covering defect 92d using the covering defect detection method described in Embodiments 1 to 5, and the core in which it is determined that there is the covering defect 92d in the determination step (step S150) is subjected to exclusion processing, and thus the rotating electric machine 100 having high reliability can be formed from the armature formed only from the intact electromagnetic wire 9 that does not include the covering defect 92d.

[0147] Explanation of Reference Numerals

[0148] 1: coating defect detection device; 2: control device; 21: A / D converter; 22: storage device; 23: measuring device; 24: time difference calculation section; 25: determination section; 26: display data generation section; 2g: image display device; 3: feeding machine (travel path forming mechanism); 4: winding machine (travel path forming mechanism); 5: discharge detection electrode; 6: alternating current power supply; 7: signal detector; 7c: coupling capacitor; 7s: voltage measurer; 7r: detection resistor; 8: de-electrification electrode; 9n: winding nozzle; 9: electromagnetic wire (coating wire); 91: wire core; 92: coating film; 9bf: bobbin; 9br: bobbin; 92d: coating defect; 100: rotary electric machine; 101: rotor; 102: stator; 102c: coil; 102i: unit core; 102t: unit stator; 103: frame; L: electrode length; t: detection interval; Sa: discharge signal; Sa1, Sa2, Sa3: signal; Sn: noise; Sp: voltage waveform; Sr: travel speed; Th: threshold value; Wr: travel path.

Claims

1. A clad defect detection apparatus characterized by comprising: The coating defect detection device has: a travel path forming mechanism that causes a coated conductor to travel and forms a travel path; a discharge detection electrode that is disposed opposite the coated conductor and is connected to an alternating-current power source that applies an alternating-current voltage, and that is set to a value or more along the length of the travel path that is obtained by multiplying the travel speed of the coated conductor by the period of 1 cycle of the alternating-current voltage; a discharge detector that detects discharge generated between the discharge detection electrode and the coated conductor; a measurement device that measures the detection interval of a discharge signal detected by the discharge detector; and a determination section that determines whether or not the coated conductor has a coating defect based on the relationship between the detection interval and the time calculated from the applied alternating-current frequency, the discharge detection electrode is composed of a plurality of discharge detection electrodes that are separately disposed at separate positions along the travel path, the determination section makes the determination according to whether or not the ratio of the detection intervals measured for the plurality of discharge detection electrodes and the ratio of the alternating-current frequencies applied to the plurality of discharge detection electrodes are in an inverse relationship.

2. The coating defect detection device according to claim 1, wherein an electric charge removing electrode that removes the electric charge of the coated conductor is provided on the upstream side of the discharge detection electrode along the travel path.

3. The coating defect detection device according to claim 1 or 2, wherein the determination section sets a discharge signal that is the measurement target of the detection interval as the object of the determination in the case where the polarity of the discharge signal is reversed.

4. The coating defect detection device according to any one of claims 1 to 3, wherein the determination section performs signal processing that compares the absolute value of the discharge signal with a threshold value, converts the case where the absolute value of the discharge signal is the threshold value or more into a first value, and converts the case where the absolute value of the discharge signal is less than the threshold value into a second value, the determination section calculates the detection interval from the signal after the signal processing.

5. The coating defect detection device according to any one of claims 1 to 3, wherein the determination section performs signal processing that smoothes the discharge signal, and calculates the detection interval from the signal after the signal processing.

6. The coating defect detection device according to any one of claims 1 to 5, wherein the determination section calculates the detection interval from a signal to which noise filtering has been applied to the discharge signal.

7. A method of detecting a coating defect, characterized by, The coating defect detection method includes the following steps: a travel path forming step that causes a coated conductor to travel and forms a travel path; a discharge detection step that applies an alternating-current voltage of a frequency shorter than a value obtained by dividing the length of a discharge detection electrode along the travel path by the travel speed of the coated conductor to the discharge detection electrode that is disposed opposite the coated conductor, and detects discharge generated between the discharge detection electrode and the coated conductor; a measurement step that measures the detection interval of the detected discharge signal; and a determination step that determines whether or not the coated conductor has a coating defect based on the relationship between the detection interval and the time calculated from the applied alternating-current frequency. determining whether the coated conductor has a coating defect based on a relationship between the detection interval and a time calculated from the frequency applied, in the discharge detection step, an alternating-current voltage of a separately set frequency is applied to each of discharge detection electrodes composed of a plurality of discharge detection electrodes dispersed at separate positions along the travel path, in the determining step, the determination is made based on whether a ratio of the detection intervals measured for the plurality of discharge detection electrodes and a ratio of the alternating-current frequencies separately applied to the plurality of discharge detection electrodes are in an inverse relationship.

8. The coating defect detection method according to claim 7, wherein in the determining step, in a case where a positive and negative inversion of a discharge signal that becomes a measurement target of the detection interval occurs, the discharge signal is set as a target of the determination.

9. The coating defect detection method according to claim 7 or 8, wherein in the determining step, signal processing is performed in which an absolute value of the discharge signal is compared with a threshold value, a case where the absolute value of the discharge signal is equal to or greater than the threshold value is converted into a first value, and a case where the absolute value of the discharge signal is less than the threshold value is converted into a second value, in the determining step, the detection interval is calculated based on a signal after the signal processing.

10. The coating defect detection method according to claim 7 or 8, wherein in the determining step, signal processing is performed in which the discharge signal is smoothed, and the detection interval is calculated based on a signal after the signal processing.

11. The coating defect detection method according to any one of claims 7 to 10, wherein in the determining step, the detection interval is calculated based on a signal after noise filtering is applied to the discharge signal.

12. A manufacturing method of a rotary electric machine characterized by comprising: The manufacturing method of the rotating electric machine includes the steps of: a stator assembling step of assembling a stator; a rotor assembling step of assembling a rotor; and a total assembling step of assembling a rotating electric machine by coaxially arranging the stator and the rotor, in any one of the stator assembling step and the rotor assembling step, in a coil forming process of winding the coated conductor around a core, it is determined whether there is a coating defect using the coating defect detection method according to any one of claims 7 to 11, and a core in which it is determined that there is a coating defect in the determining step is subjected to an exclusion process.

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