Defect detection device, defect detection method, defect detection system, and manufacturing method of rotating electric machine

Abstract

While existing inspection devices can detect the presence of fully penetrating defects such as pinholes, they struggle to detect defects where the metal wire is not exposed. To address this issue, an electrode (8) is provided, which is impregnated with a conductive liquid (7) and formed to make contact with the periphery of the insulating layer of the electromagnetic wire (2). Defects in the insulating coating are detected by measuring the amount of discharge charge generated by the partial discharge between the electromagnetic wire (2) and the conductive liquid (7).

Description

Technical Field

[0001] This application relates to defect detection devices, defect detection methods, defect detection systems, and methods for manufacturing rotating electric machines. Background Technology

[0002] Electrical insulation is typically achieved by applying a varnish to the surface of the electromagnetic wire wound around the coils of a rotating electric machine or transformer. If defects such as scratches, bubbles, or pinholes exist in the varnish layer, these areas become electrically vulnerable and may become the starting point for damage when voltage is applied.

[0003] In the prior art, one method for detecting defects in insulating films involves contacting a soft pad impregnated with a conductive liquid with the insulating film and determining the location of the defect based on the change in resistance caused by the pinhole. (See, for example, Patent Document 1)

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 5-332981 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] While such pinhole inspection methods and devices can detect the existence of fully penetrating defects like pinholes, there is a problem that it is difficult to detect non-penetrating defects caused by scratches or bubbles in the varnish layer where the metal wires of the electromagnetic wires are not exposed, based on changes in the conduction resistance.

[0009] This application was made to solve the problems mentioned above, and its purpose is to provide a defect detection device, defect detection method, defect detection system, and method for manufacturing a rotating electric machine that can detect even non-penetrating insulation coating defects in a non-destructive manner.

[0010] Methods for solving problems

[0011] The defect detection device disclosed in this application is characterized by comprising: an electrode impregnated with a conductive liquid and formed in contact with the insulating layer of an electromagnetic wire; and a partial discharge detection device connected in parallel with the electrode, wherein the electrode applies an alternating voltage between the electromagnetic wire and the conductive liquid, and the partial discharge detection device measures the amount of discharge charge of the partial discharge generated between the electromagnetic wire and the conductive liquid, thereby detecting defects in the insulating coating of the electromagnetic wire.

[0012] Invention Effects

[0013] According to the defect detection device disclosed in this application, defects in the insulation coating of electromagnetic wires can be detected in a non-destructive manner. Attached Figure Description

[0014] Figure 1 This is a structural concept diagram of a coil winding device equipped with the defect detection device of Embodiment 1.

[0015] Figure 2 This is a diagram showing the structure of the defect detection device according to Embodiment 1.

[0016] Figure 3 This is a structural concept diagram of a round-wire type electromagnetic wire inspected by the defect detection device of Embodiment 1.

[0017] Figure 4 This is a structural concept diagram of a flat-angle type electromagnetic wire inspected by the defect detection device of Embodiment 1.

[0018] Figure 5 This is a diagram showing the relationship between the motor coil wound around the iron core, the wet electrode, and the encoder during defect detection in Embodiment 1.

[0019] Figure 6 This is a diagram illustrating the relationship between the distances to the defect locations used to calculate the defect detection in Implementation Method 1.

[0020] Figure 7 This is a flowchart illustrating the measurement steps of the defect detection device in Embodiment 1.

[0021] Figure 8 This is a diagram showing the stator with the motor coil teeth arranged in a circle when viewed from the axial direction.

[0022] Figure 9 This is a diagram showing the structure of another defect detection device according to Embodiment 1.

[0023] Figure 10 This is a structural concept diagram of the liquid supply mechanism of the conductive liquid tank in Embodiment 1.

[0024] Figure 11 This is a structural diagram of the wet electrode of the defect detection device in Embodiment 2.

[0025] Figure 12 This is a structural diagram of the wet electrode of the defect detection device in Embodiment 3.

[0026] Figure 13 This is a structural concept diagram of the electromagnetic wire winding method in Implementation Method 4.

[0027] Figure 14 This is a hardware structure diagram of the control device of the defect detection device in Implementation Method 1. Detailed Implementation

[0028] Hereinafter, preferred embodiments of the defect detection device of this application will be described with reference to the accompanying drawings. Furthermore, identical reference numerals will be used for the same content and substantial portions, and detailed descriptions thereof will be omitted. Similarly, in subsequent embodiments, repeated descriptions of structures labeled with the same reference numerals will be omitted.

[0029] Implementation method 1.

[0030] Hereinafter, Embodiment 1 will be described with reference to the accompanying drawings. Figure 1 The coil winding device 100 is shown, as well as the configuration of the electromagnetic wire insulation coating defect detection device (hereinafter referred to as defect detection device 200) and its positional relationship with other devices.

[0031] The coil winding device 100 draws out an electromagnetic wire 2, which is used as material, from a spool 1, which is positioned with its axis perpendicular to the ground. The drawn electromagnetic wire 2 passes through a tensioner 3 and a nozzle 4 and is wound into a motor coil 5.

[0032] The electromagnetic wire 2 in the section from the tensioner 3 to the motor coil 5 is maintained at a predetermined tension by the tensioner 3. In addition, the electromagnetic wire 2 is electrically connected through the end of the spool 1 at the beginning of the winding.

[0033] The defect detection device 200 of this embodiment is disposed in the area between the tensioner 3 and the nozzle 4, and is positioned at a location that crosses the motion path of the electromagnetic wire 2. The coil winding device 100 is mainly classified into spindle winding, spindle winding, and nozzle winding according to the winding method, but the defect detection device 200 of this embodiment can be applied to any winding method.

[0034] Figure 2 The structure of the defect detection device 200 according to Embodiment 1 is shown. A conductive liquid tank 6 is provided, which is filled with conductive liquid 7. Rectangular wet electrodes 8A and 8B, formed of a soft and hygroscopic felt material, are disposed on the upper part of the conductive liquid tank 6, and an electromagnetic wire 2 is arranged between the wet electrodes 8A and 8B. The wet electrodes 8A and 8B are pressed and held against the electromagnetic wire 2 by a clamp 9, which is fixed to a coil winding device 100 or the conductive liquid tank 6. That is, the rectangular wet electrodes 8A and 8B are in contact with the electromagnetic wire 2 in a manner that clamps them.

[0035] The lower portion of the wet electrode 8 is immersed in the conductive liquid 7. The wet electrode 8 is hygroscopic and therefore wetted by the conductive liquid 7. Furthermore, since the wet electrode 8 is soft, it is pressed against the electromagnetic wire 2 by the clamp 9, thereby achieving full circumference contact with the electromagnetic wire 2 within the region of electrode width D1. That is, the conductive liquid 7 makes full circumference contact with the electromagnetic wire 2 within the region of electrode width D1. This structure enables efficient contact between the conductive liquid 7 and the surface of the electromagnetic wire 2.

[0036] The electromagnetic wire 2 moves with the wet electrode 8 while ensuring the contact area of ​​the electrode width D1 through the winding action of the coil winding device 100 winding the motor coil 5.

[0037] The lower part of the metal electrode 10, which is connected to the power supply V and the partial discharge detection device P, is immersed in the conductive liquid 7, and a measurement voltage is applied to the conductive liquid 7. Since the wet electrodes 8A and 8B are wetted by the conductive liquid 7, a voltage is applied to the entire circumference of the electromagnetic wire 2 in the region of electrode width D1 by connecting the power supply V.

[0038] The partial discharge detection device P is connected in parallel with the voltage application circuit. When a partial discharge occurs in the region of electrode width D1, the partial discharge detection device P detects the change in voltage or current in the circuit caused by the discharge.

[0039] Other methods for detecting partial discharge include placing a sensor outside the voltage application circuit to capture the discharge light and electromagnetic waves that accompany the partial discharge. However, this structure can perform discharge detection with higher sensitivity by directly obtaining the electrical signal within the circuit.

[0040] Figure 3 This is a cross-sectional view of a circular electromagnetic wire 2 cut perpendicular to the axis. The electromagnetic wire 2 is constructed such that it has a conductor 21 at the center of the axis, and an insulating layer 22 covers the entire surface of the conductor 21 with a predetermined coating thickness.

[0041] Figure 4 This is a cross-sectional view of an electromagnetic wire 2 of the flat-angle type cut perpendicular to the axis. Except that the cross-sectional shape of the conductor 21 is square, the basic structure is the same as... Figure 3 The circular lines are of the same type.

[0042] With this structure, electrical defects in the insulating layer 22 of the electromagnetic wire 2 can be continuously detected in a non-destructive manner using the following measurement method.

[0043] [Determination Method]

[0044] During the measurement, as described above, a power supply V is connected, and an alternating voltage is applied to the outer peripheral surface of the electromagnetic wire 2 in the region of electrode width D1.

[0045] In the case of a pinhole defect penetrating the insulating layer 22 in the measurement region of electrode width D1, since the conductive liquid 7 is in direct contact with the conductor 21 inside the insulating layer 22, a current is detected when a voltage is applied, and the insulation defect can be detected in the region of electrode width D1. Furthermore, even if an electrically vulnerable portion that does not penetrate the insulating layer 22 passes through the measurement region of electrode width D1, the defect can be detected based on the change in the partial discharge waveform before and after the defect.

[0046] Furthermore, during the winding operation in the coil winding device 100, the electromagnetic wire 2 will inevitably pass through the electrode width D1 area of ​​the defect detection device 200. Therefore, defects in the entire area of ​​the electromagnetic wire 2 can be inspected before it is wound into a motor coil 5 as a product. Thus, by applying the defect location determination method described later, the defect location in the wound motor coil can be determined. In addition, since the size of the defect can also be detected based on the detected discharge signal, larger defective portions can be removed before being wound into a motor coil by pre-determining the threshold of the discharge signal.

[0047] Next, use Figure 5 The method for determining the location of defects after the coil 5 is wound into a motor coil is explained. Figure 5 This is a diagram showing the relationship between the motor coil 5 wound around the iron core 11, the wet electrode 8, and the encoder E during defect detection. Figure 5 (a) shows the structure of the core 11 when viewed from the back of the core along the protruding direction, up to the point where the electromagnetic wire 2 is wound into the motor coil 5. The coil distance T1 is the length along the circumference of the motor, and the coil distance T2 is the length along the axial direction of the motor.

[0048] The electromagnetic wire 2 is wound around the teeth of the iron core 11 as the motor coil 5. Furthermore, for ease of understanding, Figure 5 (b) shows a perspective view of the motor coil 5 wound on the insulator 12 of the iron core 11. Figure 6 As shown, the distance L1 from the wet electrode 8 to the front end of the nozzle 4, the distance L2 from the front end of the nozzle 4 to the motor coil 5, the distance T1 in the short side direction and the distance T2 in the long side direction of the motor coil 5, and the elongation of the electromagnetic wire 2 under winding tension are known in advance.

[0049] An encoder E is installed between the wet electrode 8 and the nozzle 4 of the defect detection device 200. The distance (length) is measured based on the speed of the electromagnetic wire 2 passing through the encoder E. Signals from the partial discharge detection device P and the encoder E are input into the PC. Using the distance at the beginning of the winding of the motor coil 5 as the zero point, the winding distance until the defect is detected and the winding distance after detection are recorded. Therefore, based on the winding distance data from the encoder E, the known distances L1, L2, T1, T2, and the elongation of the electromagnetic wire 2 following the winding tension, the exact position of the defect on which turn of the motor coil 5 is located can be accurately calculated.

[0050] Figure 7 The measurement procedure is shown. The measurement procedure is executed in the control device PC. The control device PC controls the wet electrode 8, the partial discharge detection device P, and the encoder E according to the measurement procedure to perform the measurement.

[0051] Figure 14 An example of the hardware of a control device PC is shown. It consists of a processor 1000 and a storage device 2000. Although not shown, the storage device 2000 includes a volatile storage device such as random access memory and a non-volatile auxiliary storage device such as flash memory. Alternatively, a hard disk drive may be used as an auxiliary storage device instead of flash memory. The processor 1000 executes the measurement process described below by executing a program input from the storage device 2000. In this case, the program is input to the processor 1000 from the auxiliary storage device via a volatile storage device. Furthermore, the processor 1000 can output data such as calculation results and measurement values ​​to the volatile storage device of the storage device 2000, and can also save data to the auxiliary storage device via the volatile storage device.

[0052] First, winding begins using the coil winding device 100, and simultaneously, distance counting by the encoder E begins (step S1). If no defect is detected until the winding is completed, the workpiece is replaced to begin the next winding (step S12). If a defect is detected (step S2), the distance E1 counted at the time of detection is obtained and stored in the control device PC (step S3). Simultaneously with obtaining distance E1, a new count for obtaining distance E2 begins (step S4). The total distance R of the electromagnetic wire 2 required to complete winding is calculated. total The distance E1 from which the defect was detected is compared (step S5). During the comparison, distance E1 is pre-added to the known distances L1 and L2 at the start of winding (refer to...). Figure 6 (The relationships between the various distances).

[0053] The distance E1 + distance L1 + distance L2 is less than the total distance R. totalAt step S5, the defect position on the motor coil 5 corresponding to distance E1 + distance L1 + distance L2 is calculated and recorded in the control device PC (step S9). By adding the distance E1 from the detected defect to the current distance E2 from the detected defect to the present, the distance E1 from the beginning of winding to the present is set as the current distance E1 (step S11), and the counting of distance E1 continues. At this time, the distance E2 is reset (step S10).

[0054] When distance E1 + distance L1 + distance L2 equals the total distance R total or greater than the total distance R total At that time, it is presumed that a defect occurred at any location within the range from the end of the winding to the location tracing back to a distance of L1 + L2, thus the workpiece is replaced (step S7), and the defect location on the motor coil 5 corresponding to L1 + L2 - E2 is calculated (refer to...). Figure 6 The distance relationships are calculated and recorded in the control device PC (step S8). After recording, the counted distances E1 and E2 are reset (step S9).

[0055] The distance count is reset whenever the workpiece of motor coil 5 is replaced. Therefore, the deviation between the distance reading of encoder E and the actual feed of electromagnetic wire 2 will not increase as the production of motor coil 5 proceeds.

[0056] As an example, a method for determining the location of defects under spindle winding is shown, but the location of defects can also be determined under spindle winding and nozzle winding.

[0057] Through the above-described measurement process, the location of defects on the wound motor coil 5 can be accurately determined. For example, in the case of a single-tooth core motor, by pre-excluding only defective teeth, the defect rate in subsequent processes can be suppressed, and overall cost reduction can be expected. Furthermore, even with defective motor coils, by configuring them so that their positions are not adjacent when assembling the stator, they can be used smoothly without causing problems, and the yield rate can be expected to improve.

[0058] Furthermore, defects can be detected even when bubbles or cracks exist within the insulating layer 22, although the defect may not penetrate it. Specifically, when a predetermined AC voltage is applied, a partial discharge is generated between the conductive liquid 7 wetting the wet electrode 8 and the electromagnetic wire 2, and the charge is detected in the partial discharge detection device P. The amount of discharge charge detected when defects such as bubbles or cracks exist in the insulating layer 22 is greater than when there are no defects. By utilizing partial discharge in this way, defects in the insulating layer 22 can be detected even if they are not through holes like conductive holes.

[0059] If partial discharge occurs in the same location for a long period of time, it may cause the insulation layer 22 to deteriorate. However, if the feed speed of a normal winding machine is used to pass through the electrode width D1 for a short time, the deterioration is almost negligible. That is, defects in the insulation layer 22 of the electromagnetic wire 2 can be detected in a substantially non-destructive manner.

[0060] If the defect location of a coil is determined using the defect detection device and detection method of this embodiment, not only can the quality be improved in motor manufacturing, but production costs can also be expected to be reduced.

[0061] For example, in the case of manufacturing a single-tooth core motor, by pre-selecting only defective motor coils, the overall manufacturing cost can be reduced compared to discovering defects in processes after assembling the stator assembly. Moreover, even if defects exist within the coils, as long as the location of the defects is determined by a detection device, the coils can be used without being discarded.

[0062] Figure 8 This diagram illustrates the stator constructed by arranging the teeth of the motor coils into a circle when viewed from the axial direction. Figure 8 The diagram omits the rotor, which is positioned opposite the stator on the inner diameter side with a gap between it and the stator, and is capable of rotating relative to the stator. Figure 8 In the configuration shown on the left, due to the close proximity of the defects between the motor coils, a short circuit caused by discharge may occur when energized. Conversely, if... Figure 8 As shown on the right, by swapping the teeth and arranging them so that the defects are not adjacent to each other, the stator can be used freely without discarding teeth, and the pass rate can be expected to be further improved.

[0063] Partial discharge occurs at most twice per wavelength of the applied AC voltage. Therefore, assuming the frequency of the measurement voltage of the defect detection device 200 is 50 Hz, the frequency of partial discharge is 100 times per second. That is, in order to inspect the entire area of ​​the wound electromagnetic wire 2 without omission, the distance advanced per second, which is the winding speed, must be set to less than 100 times the area of ​​the electrode width D1 (less than twice the frequency). Assuming the electrode width D1 is 10 mm, the winding speed needs to be set to less than 1000 mm / sec. While increasing the area of ​​the electrode width D1 further increases the probability of defect detection, the location of the defect becomes somewhere within the same range as the electrode width D1, thus requiring attention to reduce the position determination accuracy in the motor coil 5.

[0064] exist Figure 5 , Figure 6 The example used was a round electromagnetic wire, but since the wet electrode 8 is soft, it can also be applied to... Figure 4 The flat-angle type electromagnetic wire is shown. For wet electrodes, felt materials are listed, but any soft material that is absorbent and can adhere tightly to the curved surface of the electromagnetic wire used can be used, such as sponge materials.

[0065] Examples of conductive liquids 7 include volatile alcohols such as methanol and ethanol. Liquids other than alcohols may also be used, but they must have high conductivity, low viscosity for penetrating defects such as pinholes or electromagnetic wires 2, and the property of being rapidly removable after passing through the measurement area of ​​electrode width D1.

[0066] While clamping device 9 is used to press wet electrodes 8A and 8B against electromagnetic wire 2, it also serves to prevent the conductive liquid 7 from evaporating from the surfaces of wet electrodes 8A and 8B in the air. Furthermore, the clamping device 9 can be made of resin, metal, or a conductive metal such as copper or iron, thereby achieving the desired effect. Figure 9 Remove the metal electrode 10 as shown, and directly connect the power supply V and the partial discharge detection device P to the clamp 9, and apply voltage to perform the measurement.

[0067] The conductive liquid tank 6 is made of an insulating material, specifically a material that does not dissolve in the conductive liquid 7. In this embodiment, a rectangular box shape with an open upper surface has been described, but it can be any shape—cubic, cylindrical, or conical—as long as it can hold the conductive liquid 7. Furthermore, to prevent the conductive liquid 7 from evaporating from the surface, a float can be provided, and a cover can be provided on the upper surface of the conductive liquid tank 6.

[0068] In the measurement of electromagnetic wire 2, the wet electrode 8 needs to be constantly wetted by the conductive liquid 7. When a voltage is applied to the wet electrode 8 through the metal electrode 10, both ends of the wet electrode 8 must always be below the surface of the conductive liquid 7. To maintain the liquid level, in addition to the aforementioned float body for suppressing evaporation, other methods can be used as follows: Figure 10 As shown, a liquid supply mechanism 300 for conductive liquid 7 is provided in the conductive liquid tank 6.

[0069] Figure 10 In this system, a level switch 13 is installed in the conductive liquid tank 6. Then, when the water level falls below a predetermined lower limit, valve 14 is opened to supply conductive liquid 7 from the supply tank 15 into the conductive liquid tank 6. When the upper limit water level is reached, valve 14 is closed to stop the supply of conductive liquid 7. Alternatively, a float-type level switch can be used instead of an electrical level switch.

[0070] By bringing the wet electrode 8 into contact with the surface of the conductive liquid 7 supplied to the conductive liquid tank 6 and applying an AC voltage to the conductive liquid 7 or the wet electrode 8, the conductive liquid 7 can be stably and continuously supplied to the wet electrode 8, thus keeping the wet electrode 8 constantly wet.

[0071] Implementation method 2.

[0072] Figure 2 The wet electrode 8 shown is divided into two parts, wet electrode 8A and wet electrode 8B, with the electromagnetic wire 2 sandwiched between them, but it could also be... Figure 11 The shape is similar to that of the wet electrode 8C shown. Figure 11 (a) shows a front view of the wet electrode 8C. Figure 11 (b) shows a three-dimensional view, but for ease of understanding, the clamps and conductive liquid are removed from the diagram.

[0073] Wet electrode 8C, for example, to have Figure 2 The long wet electrode, approximately twice the length of wet electrode 8A or wet electrode 8B, is a cuboid shape with its upper part bent into a U-shape. The electromagnetic wire 2 is incorporated into this bent portion. Thus, two portions extending from the U-shaped bent portion... Figure 11 The contact is as shown in (a). Furthermore, as long as the wet electrode 8C can be formed into the same shape, it is not necessary to form the electrode with a longer cuboid shape.

[0074] Based on the structure of the wet electrode 8C, it is possible to exclude... Figure 2 The tiny gaps created between the contact surfaces of the wet electrodes 8A and 8B and the upper and lower surfaces of the electromagnetic wire 2 enable the conductive liquid 7 to contact the surface of the electromagnetic wire 2 more efficiently and reliably.

[0075] Implementation method 3.

[0076] In addition, it can also be Figure 12 The shape of the wet electrode 8D is shown. Figure 12 (a) shows a front view of the wet electrode 8D. Figure 12 (b) shows a perspective view, but for ease of understanding, the clamps and conductive liquid are removed for illustration. The wet electrode 8D is a device that will have... Figure 2 A longer wet electrode, approximately 2.5 to 3 times the length of the wet electrode 8A or wet electrode 8B shown, is spirally wound relative to the electromagnetic wire 2, with both ends immersed in the conductive liquid 7.

[0077] Based on the structure of this wet electrode 8D, it is possible to eliminate [something] throughout its entire circumference. Figure 2The tiny gaps created between the contact surfaces of the wet electrodes 8A and 8B and the upper and lower surfaces of the electromagnetic wire 2 allow the conductive liquid 7 to contact the surface of the electromagnetic wire 2 more reliably than in Embodiments 1 and 2.

[0078] Furthermore, regarding the winding method of the wet electrode 8D into the electromagnetic wire 2, as long as the entire circumference of the electromagnetic wire 2 is in contact with the wet electrode 8D, it can also be done as follows: Figure 12 As shown in (b), gaps exist between adjacent wet electrodes. Furthermore, the number of turns can be two or more. However, as explained in Embodiment 1, while increasing the number of turns increases the probability of defect detection, it also increases the area of ​​electrode width D1. Therefore, care must be taken to ensure that the accuracy of determining the location of defects in the motor coil 5 decreases.

[0079] Implementation method 4.

[0080] The electromagnetic wire winding method in this embodiment can be used not only for motor coil winding, but also for other applications such as... Figure 13 It is wound around the spool as shown.

[0081] After passing through the defect detection device 200, the electromagnetic wire 2 is wound onto the winding spool 17 via the transverse mechanism 16. The axial direction of the winding spool 17 is perpendicular to the movement path of the electromagnetic wire 2, and the spool rotates by transmitting power from the servo motor 18. Figure 13 The diagram shows power transmission via a belt, but as long as it is a mechanism that rotates the shaft of the winding spool 17, the power transmission method can also be a chain or gear.

[0082] According to this embodiment, it can be used not only for motor production, but also for material receiving and inspection to determine in advance the frequency of defects in the insulation coating of the electromagnetic wire and the extent of their distribution within the spool.

[0083] Although this application describes various exemplary embodiments and examples, the various features, methods and functions described in one or more embodiments are not limited to the application of specific embodiments, and can be applied to embodiments individually or in various combinations.

[0084] Therefore, numerous variations not illustrated can be conceived within the scope of the technology disclosed in this application. These include variations on at least one constituent element, additions, omissions, and extraction of at least one constituent element combined with constituent elements of other embodiments.

[0085] Label Explanation

[0086] 1: Bollard; 2: Electromagnetic wire; 3: Tensioner; 4: Nozzle; 5: Motor coil; 6: Conductive liquid tank; 7: Conductive liquid; 8, 8A, 8B, 8C, 8D: Wet electrode; 9: Clamping device; 10: Metal electrode; 11: Iron core; 12: Insulator; 13: Liquid level switch; 14: Valve; 15: Liquid supply tank; 16: Transverse movement mechanism; 17: Winding bollard; 18: Servo motor; 100: Coil winding device; 200: Defect detection device; 300: Liquid supply mechanism; 1000: Processor; 2000: Storage device.

Claims

1. A defect detection device characterized by comprising: an electrode which is impregnated with an electrically conductive liquid and is formed so as to contact the periphery of an insulator layer of an electromagnetic wire with the electrically conductive liquid; and a partial discharge detection device which is connected in parallel with the electrode, the electrode applying an alternating voltage between the electromagnetic wire and the electrically conductive liquid, and the partial discharge detection device measuring the discharge charge amount of a partial discharge generated between the electromagnetic wire and the electrically conductive liquid, thereby detecting a defect of an insulating coating of the electromagnetic wire and the size thereof.

2. The defect detection device according to claim 1, characterized in that the electrode is formed so as to contact the entire periphery of the insulator layer of the electromagnetic wire which is running with the electrically conductive liquid.

3. The defect detection device according to claim 1, characterized in that the electrode is a wet electrode which is composed of a soft and hygroscopic material.

4. The defect detection device according to claim 2, characterized in that the electrode is a wet electrode which is composed of a soft and hygroscopic material.

5. The defect detection device according to claim 3, characterized in that the electrode contacts the liquid surface of the electrically conductive liquid in an electrically conductive liquid tank.

6. The defect detection device according to claim 5, characterized in that the electrically conductive liquid tank is provided with a liquid supply mechanism which is composed of a liquid level switch, a liquid supply tank of the electrically conductive liquid, and a valve.

7. The defect detection device according to any one of claims 1 to 6, characterized in that the electrode is configured so that two cuboid-shaped wet electrodes sandwich the electromagnetic wire.

8. The defect detection device according to any one of claims 1 to 6, characterized in that the electrode is in a U shape and is formed so as to contact the periphery of the electromagnetic wire with a bent portion for forming the U.

9. The defect detection device according to any one of claims 1 to 6, characterized in that the electrode is formed so as to be wound in a spiral shape on the electromagnetic wire.

10. The defect detection device according to any one of claims 1 to 6, characterized by comprising a clamp which sandwiches the electrode from an outer surface.

11. A defect detection system, wherein the defect detection system is provided with: a coil winding device which winds an electromagnetic wire into a motor coil; and the defect detection device according to any one of claims 1 to 10, the defect detection device detecting a defect of the electromagnetic wire before the electromagnetic wire is wound into a motor coil in the coil winding device.

12. A defect detection system, wherein the defect detection system is provided with: a coil winding device which winds an electromagnetic wire into a motor coil; and the defect detection device according to any one of claims 1 to 10, the defect detection device being provided with a winding bobbin which is connected with a rotational power behind the electrode in the defect detection device.

13. A defect detection system, characterized by ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The defect detection system is provided with a coil winding device that winds an electromagnetic wire into a motor coil, and the defect detection device according to any one of claims 1 to 10, with an encoder that detects the speed of the electromagnetic wire being arranged between the electrode in the defect detection device and the motor coil, the defect detection system calculating the position of a defect of the electromagnetic wire wound into the motor coil based on the output of the encoder and the defect detection signal output from the defect detection device.

14. A defect detection method characterized by, using a coil winding device that winds an electromagnetic wire into a motor coil, the defect detection device according to any one of claims 1 to 10, and an encoder that detects the speed of the electromagnetic wire between the electrode in the defect detection device and the motor coil, calculating the position of a defect of the motor coil based on the winding distance until a defect is detected and the winding distance after a defect is detected, with the distance of the winding start end of the motor coil as the zero point.

15. A manufacturing method of a rotary electric machine, wherein, a rotary electric machine is manufactured using a motor coil that has been subjected to defect detection using a coil winding device that winds an electromagnetic wire into the motor coil and the defect detection device according to any one of claims 1 to 10.

16. A defect detection device characterized by, the defect detection device is provided with an electrode that is impregnated with an electrically conductive liquid and formed so as to contact the periphery of an insulator layer of an electromagnetic wire with the electrically conductive liquid, and a partial discharge detection device that is connected in parallel with the electrode, the defect detection device applying an alternating-current voltage between the electromagnetic wire and the electrode, measuring the discharge charge amount of a partial discharge generated between the electromagnetic wire and the electrically conductive liquid using the partial discharge detection device, thereby detecting a defect of an insulating coating of the electromagnetic wire and the size thereof.

17. The defect detection device according to claim 16, characterized in that, the electrode is formed so as to contact the entire periphery of the insulator layer of the electromagnetic wire that is advancing with the electrically conductive liquid.

18. The defect detection device according to claim 16, characterized in that, the electrode is a wet electrode that is composed of a soft and hygroscopic material.

19. The defect detection device according to claim 17, characterized in that, the electrode is a wet electrode that is composed of a soft and hygroscopic material.

20. The defect detection device according to claim 18, characterized in that, the electrode contacts the liquid surface of the electrically conductive liquid in an electrically conductive liquid tank.

21. The defect detection device according to claim 20, characterized in that, the electrically conductive liquid tank is provided with a liquid supply mechanism composed of a liquid level switch, a liquid supply tank of the electrically conductive liquid, and a valve.

22. The defect detection device according to any one of claims 16 to 21, characterized in that, the electrode is configured with two wet electrodes of a cuboid shape sandwiching the electromagnetic wire.

23. The defect detection device according to any one of claims 16 to 21, characterized in that, The electrode is in a U shape, and a bent portion for forming the U shape is in contact with the periphery of the electromagnetic wire.

24. The defect detection device according to any one of claims 16 to 21, characterized in that, The electrode is formed in a spiral shape wound around the electromagnetic wire.

25. The defect detection device according to any one of claims 16 to 21, characterized in that, The defect detection device is provided with a clamp that clamps the electrode from the outer surface.

26. A defect detection system, wherein The defect detection system is provided with: a coil winding device that winds an electromagnetic wire into a motor coil; and the defect detection device according to any one of claims 16 to 25, which detects a defect of the electromagnetic wire before the electromagnetic wire is wound into the motor coil in the coil winding device.

27. A defect detection system, wherein The defect detection system is provided with: a coil winding device that winds an electromagnetic wire into a motor coil; and the defect detection device according to any one of claims 16 to 25, which is provided with a winding bobbin connected to a rotational power source behind the electrode in the defect detection device.

28. A defect detection system, wherein The defect detection system is provided with: a coil winding device that winds an electromagnetic wire into a motor coil; and the defect detection device according to any one of claims 16 to 25, an encoder that detects a speed of the electromagnetic wire is arranged between the electrode in the defect detection device and the motor coil, and the defect detection system calculates a position of a defect of the electromagnetic wire wound into the motor coil based on an output of the encoder and a defect detection signal output from the defect detection device.

29. A defect detection method, wherein A coil winding device that winds an electromagnetic wire into a motor coil, the defect detection device according to any one of claims 16 to 25, and an encoder that detects a speed of the electromagnetic wire between the electrode in the defect detection device and the motor coil are used, a distance from a winding start end of the motor coil is taken as zero, and a position of a defect of the motor coil is calculated based on a winding distance until the defect is detected and a winding distance after the defect is detected.

30. A manufacturing method of a rotary electric machine, wherein A rotary electric machine is manufactured using a motor coil that has been subjected to defect detection using a coil winding device that winds an electromagnetic wire into the motor coil and the defect detection device according to any one of claims 16 to 25.

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