JP7592196B2 - Winding load reproduction device, magnet wire insulation coating inspection device, magnet wire insulation coating inspection method, and rotating electric machine manufacturing method - Google Patents

Description

This application relates to a winding load reproduction device, a magnet wire insulation coating inspection device, a magnet wire insulation coating inspection method, and a manufacturing method for a rotating electric machine.

The magnet wire wound around the coils of motors and transformers has its surface coated with varnish to provide electrical insulation. If the varnish insulating coating has defects such as scratches, air bubbles, pinholes, or cracks, these become electrically weak spots and can become the starting point of breakdown when voltage is applied.

As a method for detecting coating defects, a method for detecting defects before the magnet wire to be used is wound has been disclosed (for example, Patent Document 1). Also, a method for identifying the location of defects by immersing the coil after winding in a conductive liquid has been disclosed (for example, Patent Document 2).

JP 2008-42147 A Patent No. 3614141

In the manufacture of winding products, when selecting the magnet wire material to be used, an inspection method and inspection device are required to grasp the frequency of defects in the insulation coating in advance. In addition, in order to reduce the occurrence of electrical defects in winding products, it is necessary to grasp not only defects that occur during magnet wire manufacturing and transportation, but also defects caused by the loads received during the manufacture of winding products.
However, with the method of Patent Document 1, it is difficult to detect defects in the insulation coating that occur during the manufacturing process of the winding product, and with the method of Patent Document 2, inspection is performed after the winding product is completed, which results in a problem that inspecting the entire product is very costly and time-consuming.

This application discloses technology to solve the above-mentioned problems, and aims to provide an apparatus and inspection method that reproduces the load that the magnet wire insulation coating experiences when manufacturing a winding product and detects any defects that may occur in the insulation coating.

The winding load reproduction device disclosed in the present application includes a load reproduction mechanism that reproduces at least one load of friction or stretching on the insulating coating of a magnet wire, and simulates the occurrence of defects in the insulating coating of a magnet wire during the manufacture of a winding product.The load reproduction mechanism includes a back tensioner that clamps the magnet wire between multiple plates, and a back tensioner load reproduction section that applies kinetic friction force to the passing magnet wire and presses it from both sides to reproduce the load on the insulating coating due to friction .
The magnet wire insulation coating inspection device disclosed in the present application includes a winding load reproduction device, and further includes a defect detection device that detects defects in the insulation coating of the magnet wire.
The magnet wire insulation coating inspection device disclosed in the present application includes a load reproduction mechanism that reproduces at least one load of friction or stretching on the insulation coating of a magnet wire, a winding load reproduction device that simulates the occurrence of defects in the insulation coating of a magnet wire in the manufacture of a winding product, and a defect detection device that detects defects in the insulation coating of the magnet wire. The defect detection device is impregnated with a conductive liquid in a conductive liquid tank and includes electrodes formed so that the conductive liquid comes into contact with the periphery of the insulation coating of the magnet wire. A voltage is applied between the conductive portion of the magnet wire and the electrodes, and the amount of discharge charge of partial discharge occurring between the magnet wire and the conductive liquid is measured to detect defects in the insulation coating of the magnet wire.
The magnet wire insulation coating inspection method disclosed in the present application is a method for detecting defects in the insulation coating of a magnet wire, and includes a back tensioner load reproduction step in which a back tensioner clamps the magnet wire between multiple plates to apply a kinetic frictional force to the passing magnet wire and press it from both sides to reproduce the load on the insulation coating due to friction.
The manufacturing method of a rotating electric machine disclosed in the present application includes a step of manufacturing a rotating electric machine using a wound iron core using magnet wire from the same lot as magnet wire that has been inspected using an inspection method for magnet wire insulation coating and found to have no problem with the tendency of occurrence of insulation coating defects in the magnet wire due to winding load.

The winding load reproducing device disclosed in the present application can reproduce the load that the magnet wire insulating coating experiences when a winding product is manufactured.
The magnet wire insulation coating inspection device disclosed in the present application can provide a device that reproduces the load that the magnet wire insulation coating receives when manufacturing a winding product and detects any defects in the insulation coating that occur.
The magnet wire insulation coating inspection method disclosed in the present application can provide a method for reproducing the load that the magnet wire insulation coating experiences when a winding product is manufactured and detecting defects in the insulation coating that occur.
According to the manufacturing method of a rotating electric machine disclosed in the present application, it is possible to provide a rotating electric machine that uses the same lot of magnet wire that has been inspected by an inspection method for magnet wire insulation coating and that has been found to have no problem with the tendency of occurrence of insulation coating defects due to winding load.

1 is an overall configuration diagram of an inspection device for a magnet wire insulating coating according to a first embodiment; 3 is a schematic configuration diagram of a back tensioner load reproducing section of the winding load reproducing device according to the first embodiment. FIG. 3 is a schematic configuration diagram of a winding nozzle load reproducing section of the winding load reproducing device according to the first embodiment; FIG. 3 is a schematic configuration diagram of a tension fluctuation load reproducing section of the winding load reproducing device according to the first embodiment; FIG. 4 is a perspective view of a dummy core rotating body of a tension fluctuation load reproducing portion of the winding load reproducing device according to embodiment 1. FIG. 3 is a schematic configuration diagram of a core corner load reproduction section of the winding load reproduction device according to the first embodiment; FIG. 4 is a perspective view of a corner reproduction rotor of a core corner load reproduction portion of the winding load reproduction device according to embodiment 1; FIG. 3 is a schematic configuration diagram of a core corner load reproduction section of the winding load reproduction device according to the first embodiment; FIG. 1 is a configuration diagram of a defect detection device for an inspection device for a magnet wire insulating coating according to a first embodiment. FIG. Fig. 10A is a structural conceptual diagram of an inspection target (round wire type) of the magnet wire insulation coating inspection device according to embodiment 1. Fig. 10B is a structural conceptual diagram of an inspection target (rectangular wire type) of the magnet wire insulation coating inspection device according to embodiment 1. 4 is another configuration diagram of the defect detection device of the inspection device for the magnet wire insulating coating according to embodiment 1. FIG. 4 is a conceptual diagram showing the configuration of a conductive liquid supply mechanism of the magnet wire insulation coating inspection device according to embodiment 1. FIG. 4 is a flowchart of a method for inspecting a magnet wire insulating coating according to the first embodiment. 4 is an explanatory diagram of an example of application of the magnet wire insulation coating inspection method according to the first embodiment to a rotating electric machine; Fig. 15A is a structural diagram of a wet electrode of the magnet wire insulation coating inspection device according to embodiment 2. Fig. 15B is a perspective view of the wet electrode of the magnet wire insulation coating inspection device according to embodiment 2. Fig. 16A is a structural diagram of a wet electrode of the magnet wire insulation coating inspection device according to embodiment 2. Fig. 16B is a perspective view of the wet electrode of the magnet wire insulation coating inspection device according to embodiment 2. FIG. 11 is a configuration diagram of a defect detection device for an inspection device for a magnet wire insulating coating according to embodiment 3.

Embodiment 1.
The first embodiment is provided with a load reproduction mechanism that reproduces at least one load of friction or stretching on the insulation coating of the magnet wire, and simulates the occurrence of defects in the insulation coating of the magnet wire in the manufacture of a winding product. The first embodiment also relates to an inspection device for the magnet wire insulation coating that is provided with a winding load reproduction device. The first embodiment also relates to an inspection method for the magnet wire insulation coating using the winding load reproduction device, and a manufacturing method for a rotating electric machine that uses a wound core and a magnet wire that has been inspected by the magnet wire insulation coating inspection method and found to have no problem with the tendency of occurrence of insulation coating defects due to winding load.

Hereinafter, the winding load reproduction device, the magnet wire insulation coating inspection device, the magnet wire insulation coating inspection method, and the rotating electric machine manufacturing method according to the first embodiment will be described with reference to FIG. 1 which is an overall configuration diagram of the magnet wire insulation coating inspection device, FIG. 2 which is a schematic configuration diagram of a back tensioner load reproduction section of the winding load reproduction device, FIG. 3 which is a schematic configuration diagram of a winding nozzle load reproduction section, FIG. 4 which is a schematic configuration diagram of a tension fluctuation load reproduction section, FIG. 5 which is a perspective view of a dummy core rotor, FIG. 6 which is a schematic configuration diagram of a core corner load reproduction section, FIG. 7 which is a perspective view of a corner reproduction rotor, FIG. 8 which is a schematic configuration diagram of the core corner load reproduction section, FIG. 9 which is a configuration diagram of a defect detection device of the magnet wire insulation coating inspection device, FIG. 10A which is a structural conceptual diagram of an inspection object (round wire type), FIG. 10B which is a structural conceptual diagram of an inspection object (rectangular wire type), FIG. 11 which is another structural diagram of the defect detection device, FIG. 12 which is a structural conceptual diagram of a conductive liquid supply mechanism of the inspection device, FIG. 13 which is a flowchart of the magnet wire insulation coating inspection method, and FIG. 14 which is an explanatory diagram of an application example of the magnet wire insulation coating inspection method to a rotating electric machine.
In each drawing, the same or corresponding parts are indicated by the same reference numerals, and duplicated explanations will be omitted.

First, the overall configuration of an inspection device 100 for an insulating coating of a magnet wire according to the first embodiment will be described with reference to FIG.
The magnet wire insulation coating inspection device 100 of the first embodiment includes a winding load reproduction device 300, a defect detection device 400, and a wire sweep device (servo motor 5, etc.) in order to inspect the magnet wire to be inspected.

First, the overall operation of the magnet wire insulation coating inspection device 100 (the flow of the magnet wire 2) will be described.
The wire sweeping device is a device for sweeping the magnet wire 2 to be inspected,
The system includes a supply bobbin 1, a tensioner 3, a take-up bobbin 4, a servo motor 5, and traverse mechanisms 6A and 6B.
In Fig. 1, the arrow "WPD" indicates the traveling direction of the magnet wire 2. The same applies to Fig. 2 and subsequent figures. When there is no need to distinguish between the traverse mechanisms 6A and 6B, they will be referred to as the traverse mechanism 6 as appropriate.

In the magnet wire insulation coating inspection device 100, a magnet wire 2, which is a material, is drawn out from a supply bobbin 1 placed so that its axial direction is perpendicular to the ground. The drawn out magnet wire 2 passes through a tensioner 3, a winding load reproduction device 300, a defect detection device 400, and a traverse mechanism 6, and is wound up on a take-up bobbin 4.
The axial direction of the winding bobbin 4 is perpendicular to the direction of travel of the magnet wire 2, and the shaft rotates when power is transmitted from a servo motor 5.
The magnet wire 2 in the section from the tensioner 3 to the winding bobbin 4 is maintained at a predetermined tension by the tensioner 3. The magnet wire 2 is also installed so as to be electrically connected through the end of the supply bobbin 1 on the winding start side.
Although FIG. 1 shows power transmission by a belt, a chain and gears may be used for the power transmission system as long as the mechanism rotates the shaft of the winding bobbin 4.

In this embodiment, the winding load reproduction device 300 is disposed in the region between the traverse mechanisms 6A and 6B behind the tensioner 3, and is installed at a location where the flow line of the magnet wire 2 crosses.
The defect detection device 400 is disposed in the region between the winding load reproduction device 300 and the traverse mechanism 6B, and is installed at a location where the flow line of the magnet wire 2 crosses.

Next, the winding load reproduction device 300 will be described.
The winding load reproduction device 300 has a function of reproducing the load that the magnet wire receives on the path from when it is supplied from the bobbin to when it is wound around the core, when production is performed using a general motor coil winding machine.
That is, the winding load reproduction device 300 includes a load reproduction mechanism that reproduces at least one load of friction or stretching on the insulating coating of the magnet wire, and can simulate the occurrence of defects in the insulating coating of the magnet wire during the manufacture of a winding product.
For example, in the case of a spindle winding machine, the magnet wire is subjected to mainly (1) load due to friction with the tensioner, (2) load due to friction with the winding nozzle, (3) load due to tension fluctuations that occur when winding around a rectangular core, and (4) load due to bending at the corners of the core when winding around a rectangular motor core.

By reproducing the load on the path in the motor coil winding machine using the winding load reproduction device 300, it is possible to grasp not only defects such as pinholes that exist from the magnet wire production process, but also defects such as cracks caused by the load of motor coil processing. This is expected to enable more accurate performance evaluation of magnet wire when selecting materials for motor manufacturing.

The winding load reproducing device 300 includes, as load reproducing mechanisms, a back tensioner load reproducing section 300A, a winding nozzle load reproducing section 300B, a tension fluctuation load reproducing section 300C, and a core corner load reproducing section 300D.
The configuration, function and operation of each load reproduction unit will be described in turn with reference to FIG. 2 to FIG.
In addition, when the load reproduction units (300A, 300B, 300C, 300D) are not differentiated from one another and are collectively described, they are appropriately described as a load reproduction mechanism.

The back tensioner load reproducing unit 300A will be described with reference to Fig. 2. The back tensioner load reproducing unit 300A reproduces the load caused by friction with the tensioner described in (1) above. In Fig. 2, P stands for "pressure."
In the back tensioner load reproduction section 300A, the back tensioner 31 sandwiches the magnet wire 2 between multiple sapphire plates 32, and applies kinetic friction force to the passing magnet wire 2 to press it from both sides. An air cylinder or the like is used for the pressing force and its adjustment.
Also, although the present embodiment is described using a sapphire plate, other crystalline materials and even felt materials may be used instead.
Even in the case of simulating an actual coil winding process, the winding nozzle is installed in front of the load reproduction section 300B in FIG.

The winding nozzle load reproducing section 300B will be described with reference to Fig. 3. The winding nozzle load reproducing section 300B reproduces the load due to friction with the winding nozzle as described in (2) above.
The winding nozzle load reproduction section 300B is provided with a hollow winding nozzle 33, a pulley 34, and a movable pulley 35, and the magnet wire 2 is passed through the winding nozzle 33 and the pulley 34. The winding nozzle 33 and the pulley 34 are fixed within the inspection device 100 for the magnet wire insulation coating.
The winding nozzle load reproduction unit 300B includes a hollow winding nozzle 33 and reproduces the load on the insulating coating caused by friction with the end of the winding nozzle when the magnet wire 2 passes through the inside of the winding nozzle and is wound.
The fixed position of the movable pulley 35 can be moved back and forth along the traveling direction of the magnet wire 2 after it has passed the movable pulley 35. By changing the angle at which the magnet wire 2 emerges from the nozzle opening of the winding nozzle 33, the friction load that the magnet wire 2 receives with the winding nozzle 33 can be adjusted as desired.

The tension variation load reproducing unit 300C will be described with reference to Figures 4 and 5. The tension variation load reproducing unit 300C reproduces the load due to tension variation that occurs when winding a wire around the rectangular parallelepiped core in (3) above.
4 is a side view of the tension fluctuation load reproducing section 300C.
Even in the case of simulating an actual coil winding process, the winding nozzle is installed behind the load reproduction section 300B.

The tension fluctuation load reproducing section 300C includes a dummy core rotor 36, a dancer roller 37, and a pulley 34. The magnet wire 2 passing through is wound around the dummy core rotor 36 one or more times as shown in the perspective view of the dummy core rotor 36 in FIG.
When the dummy core rotor 36 rotates, its square, rectangular cross-sectional shape generates periodic and steep tension fluctuations along the flow path. This allows the tension fluctuation load of an actual spindle winding to be reproduced. The dancer roller 37 absorbs tension fluctuations that occur along the subsequent flow path.

In addition, a guide with an area larger than the cross-sectional shape is provided at the axial end of the dummy core rotor 36 to prevent the magnet wire 2 from falling off during rotation. It is desirable to use a material with high friction for the side surface of the dummy core rotor 36 so that the magnet wire 2 in contact therewith does not slip.
The cross-sectional shape of the dummy core rotor 36 can be matched to the cross-sectional shape of the motor core expected to be used in production.
As described above, the tension fluctuation load reproduction unit 300C is equipped with a dancer roller 37 and a rectangular shaped dummy core rotor 36, and reproduces the load on the insulating coating due to tension fluctuations by generating periodic and steep tension fluctuations in the movement path of the magnet wire 2 using the dummy core rotor 36.

The core corner load reproducing portion 300D will be described with reference to Figures 6, 7 and 8. The core corner load reproducing portion 300D reproduces the load caused by bending at the core corners when winding the rectangular parallelepiped motor core of (4) above.
Fig. 6 is a side view of the core corner load reproducing portion 300D. Fig. 7 is a perspective view of the corner reproduction rotating body 38. Fig. 8 is a side view of the core corner load reproducing portion 300D using the rounded corner reproduction rotating body 39.

The core corner load reproducing section 300D includes a rectangular parallelepiped corner reproducing rotor 38 and a pulley 34. The position of the pulley 34 is adjusted so that the copper wire path of the magnet wire 2 passing through the corner reproducing rotor 38 is bent at a right angle at the corner reproducing rotor 38 as shown in the perspective view of the corner reproducing rotor 38 in FIG.
When the corner reproduction rotor 38 rotates, a periodic bend of up to 90° occurs in the movement path due to the square cross-sectional shape, so that the bending load of the magnet wire at the core corner of the actual spindle winding can be reproduced.

Similarly to the dummy core rotor 36, a guide with an area larger than the cross-sectional shape is provided at the axial end of the corner-reproducing rotor 38 to prevent the magnet wire 2 from falling off during rotation. It is desirable to use a material with high friction for the side surface of the corner-reproducing rotor 38 so that the magnet wire 2 in contact with it does not slip.
The cross-sectional shape of the corner reproduction rotor 38 can be matched to the R of the corners of the motor core expected to be used in production.

Although the tension fluctuation load reproduction unit 300C can also reproduce the bending load of the magnet wire at the core corners using the dummy core rotor 36, the use of the core corner load reproduction unit 300D allows the circumferential length of the corner reproduction rotor 38 to be shorter than that of the motor core. This allows the bending load at the core corners to be reproduced on the magnet wire at a higher density than in the case of a motor core for the same wire length.

As shown in the side view of the core corner load reproduction unit 300D in Fig. 8, if a cylindrical round corner reproduction rotor 39, which is a pulley having a minute diameter equivalent to the radius of the motor core corner, is used instead of the corner reproduction rotor 38, the load due to the bending of the core corner can be continuously reproduced on the magnet wire. In other words, a bending equivalent to the radius of the motor core corner is continuously generated in the flow path.

When distinguishing between the core corner load reproduction section in Fig. 6 using the corner reproduction rotor 38 and the core corner load reproduction section in Fig. 8 using the rounded corner reproduction rotor 39, the core corner load reproduction section in Fig. 6 is referred to as a periodic bent core corner load reproduction section. The core corner load reproduction section in Fig. 8 is referred to as a continuous bent core corner load reproduction section. When not distinguishing between them and describing them together, they are referred to as a core corner load reproduction section.

In this embodiment, by adjusting the settings of each load reproduction section (300A, 300B, 300C, 300D) shown in Figures 2 to 8, it is possible to reproduce the load that the magnet wire receives along the flow line path in various winding machines.
For example, when reproducing the load in a nozzle winding machine, in the winding nozzle load reproduction unit 300B in FIG. 3, the movable pulley 35 is moved to immediately below the nozzle outlet, and the path of the magnet wire 2 is changed so that it is bent 90° at the nozzle outlet.
The load on the magnet wire in the magnet wire flow path of the flyer winding machine is basically the same as that of the spindle winding machine. However, by moving the movable pulley 35 in accordance with the production equipment to which it is applied and adjusting the angle of the magnet wire at the nozzle outlet, it is possible to reproduce a load close to the actual load.

Next, the configuration, functions and operations of the defect detection device 400 will be described with reference to FIG.
The defect detection device 400 includes, as equipment for applying a partial discharge detection voltage to the magnet wire 2, a conductive liquid tank 41, a conductive liquid 42, wet electrodes 43A, 43B, a metal electrode 44 with its lower portion immersed in the conductive liquid 42, and a clamp 45 for holding the wet electrode 43.
The defect detection device 400 further includes a power supply 46 for applying a detection voltage between the conductor of the magnet wire 2 and the surface of the insulating coating, a partial discharge detection device 47, and a personal computer 48 as devices for detecting partial discharge.
In FIG. 9, "D1" represents the electrode width of the wet electrode 43, and a personal computer is written as "PC."
Furthermore, the wet electrodes 43A and 43B will be referred to as the wet electrodes 43 unless there is a particular need to distinguish between them.

A conductive liquid 42 is held inside a conductive liquid tank 41. Rectangular wet electrodes 43A and 43B made of a soft, hygroscopic felt material are provided on the upper part of the conductive liquid tank 41. A magnet wire 2 is disposed between these wet electrodes 43A and 43B.
The wet electrodes 43A, 43B are pressed against and held by a clamp 45 fixed to the conductive liquid tank 41. That is, the rectangular parallelepiped wet electrodes 43A, 43B are in contact with the magnet wire 2 so as to sandwich the magnet wire 2 therebetween.

The wet electrode 43, whose lower part is immersed in the conductive liquid 42, is hygroscopic and is therefore wet with the conductive liquid 42. Furthermore, since the wet electrode 43 is soft, it is pressed against the magnet wire 2 by the clamp 45 and comes into contact with the entire circumference of the magnet wire 2 in the region of electrode width D1 of the wet electrode 43. That is, the conductive liquid 42 comes into contact with the entire circumference of the magnet wire 2 in the region of electrode width D1 of the wet electrode 43. This configuration allows the conductive liquid 42 to come into efficient contact with the surface of the magnet wire 2.
The magnet wire 2 slides against the wet electrode 43 while maintaining a contact area of electrode width D1 due to the winding operation onto the winding bobbin 4 of FIG. 1 described in the overall operation of the inspection apparatus 100 for magnet wire insulation coating.

The metal electrode 44, which is connected to the power source 46 and the partial discharge detection device 47, has its lower part immersed in the conductive liquid 42 and is used as an electrode that applies a partial discharge detection voltage to the conductive liquid 42. Furthermore, since the wet electrodes 43A and 43B are wetted with the conductive liquid 42, when the power source 46 is connected, a partial discharge detection voltage is applied to the entire circumference of the magnet wire 2 in the region of the electrode width D1 of the wet electrode 43.

Here, two types of magnet wires 2 will be described with reference to Figs. 10A and 10B.
10A is a cross-sectional view taken perpendicular to the axial direction of a round magnet wire 21. The magnet wire 21 has a conductor 21A at the center of the axis, and its entire surface is covered with an insulating coating 21B of a set thickness.
10B is a cross-sectional view taken perpendicular to the axial direction of a rectangular magnet wire 22. The basic structure is the same as that of the round wire in FIG. 10A, except that the cross-sectional shapes of the conductor 22A and the insulating coating 22B are rectangular.
Since the magnet wire 21 (22) has such a configuration, it is possible to continuously detect electrical defects in the insulating coating 21B (22B) of the magnet wire 21 (22) by the following measurement method.
In order to distinguish between them, the round wire type is referred to as magnet wire 21 and the rectangular wire type is referred to as magnet wire 22. When describing them collectively, they are referred to as magnet wire 2, and when necessary, the round wire type magnet wire 21 is described as a representative example.

Since each load reproduction section of the winding load reproduction device 300 can be attached and detached individually, it is possible to isolate and verify the cause of the defect.
In other words, according to the configuration of this embodiment, it is possible to determine whether a defect occurring in the magnet wire 2 is due to the influence of the load from the winding nozzle, the influence of the load from the back tensioner 31, or the characteristics of the magnet wire strand.
As a result, appropriate measures can be taken in the development of winding products, such as changing the design of the nozzle tip shape of the winding machine, reducing the pressing force of the back tensioner 31, or changing the magnet wire 2 to a grade with higher wear resistance.

The magnet wire insulation coating inspection device 100 is intended to be used for selecting magnet wire materials and for considering load design in a winding machine, and inspected magnet wires are not generally reused in production. Note that magnet wires from the same production lot as magnet wires that have been inspected and found to have no problem with the tendency for insulation coating defects to occur due to winding loads may be used to manufacture stators for use in rotating electric machines.

Next, a specific method for detecting defects in the insulating coating of the magnet wire 2 will be described.
Although either a DC power supply or an AC power supply can be used as the power supply for applying a voltage for detecting partial discharge, the following description will be given assuming that an AC power supply is used, since it is easy to generate a high voltage.
When detecting defects in the insulating coating of the magnet wire 2, as described above, the power source 46 is connected to the conductor 21A of the magnet wire 2 and the metal electrode 44, and an AC voltage is applied to the outer surface of the magnet wire 2 in the region of the electrode width D1 of the wet electrode 43.
If a pinhole defect penetrating the insulating coating 21B exists in the detection area of the electrode width D1 of the wet electrode 43, the conductive liquid 42 will be in direct contact with the conductor 21A inside the insulating coating 21B, so that a current will be detected when a voltage is applied, and an insulating defect can be detected in the electrode width D1 area.

In addition, when the winding operation is performed in the magnet wire insulation coating inspection device 100, the magnet wire 2 always passes through the electrode width D1 area of the wet electrode 43 of the defect detection device 400. Therefore, defects that occur during manufacturing and due to winding load can be detected for the entire area of the magnet wire 2 unwound from the supply bobbin 1.

Furthermore, even if there are air bubbles or cracks inside the insulating coating 21B, but not penetrating through, it is possible to detect defects in the insulating coating.
That is, by applying an AC voltage of a predetermined magnitude, partial discharge occurs between the magnet wire 2 and the conductive liquid 42 that wets the wet electrode 43, and the charge is detected by the partial discharge detection device 47. When the insulating coating 21B has a defect such as an air bubble or a crack, the amount of discharge charge detected is larger than when there is no defect.
By using partial discharge in this manner, it is possible to detect defects in the insulating coating 21B even if they are not through holes that provide electrical continuity.

If partial discharge occurs in the same place for a long period of time, it can cause deterioration of the insulating coating 21B, but if it occurs within the time it takes for the wet electrode 43 to pass through the electrode width D1 at the feed speed of a typical winding machine, it is hardly affected by deterioration. In other words, it is possible to detect defects in the insulating coating 21B of the magnet wire 2 non-destructively.

Partial discharges occur a maximum of two times per wavelength of the applied AC voltage. Therefore, if the frequency of the measurement voltage of the defect detection device 400 is 50 Hz, the occurrence frequency of partial discharges is 100 times per second.
Therefore, in order to thoroughly inspect the entire area of the wound magnet wire 2 for defects, the winding speed, that is, the distance traveled per second, must be set to 100 times or less (2 times or less the frequency) the area of the electrode width D1 of the wet electrode 43. If the electrode width D1 is 10 mm, the winding speed must be set to 1000 mm/sec or less.
If the electrode width D1 of the wet electrode 43 is further increased, it is expected that the probability of detecting defects in the insulating coating of the magnet wire 2 will be further improved.

The above explanation has been given using the round wire-type magnet wire 21 in FIG. 10A as an example, but since the wet electrode 43 is soft, it is equally applicable to the rectangular wire-type magnet wire 22 shown in FIG. 10B.
Although a felt material has been mentioned as the material for the wet electrode 43, any material may be used as long as it is absorbent, soft enough to be able to adhere closely to the curved surface of the magnet wire 2 to be used, and conductive, such as a sponge-like material. In other words, the wet electrode 43 may be a sponge electrode.

Volatile alcohols such as methyl alcohol and ethyl alcohol can be used for the conductive liquid 42. The conductive liquid 42 may be a liquid other than alcohols, but it must have high conductivity and low viscosity to penetrate defects in the magnet wire 2 such as pinholes. The conductive liquid 42 must also have the property of being quickly removed after passing through the detection area of the electrode width D1 of the wet electrode 43.

The clamps 45 are used to press the wet electrodes 43A, 43B against the magnet wire 2, and also serve to prevent the conductive liquid 42 from evaporating from the surfaces of the wet electrodes 43A, 43B in the air.
The material of the clamp 45 may be resin or metal, but by using a conductive metal material such as copper or iron, the metal electrode 44 can be eliminated, as will be described next.

Here, another example of the configuration of the defect detection device in which the metal electrode 44 is omitted will be described with reference to FIG.
The defect detection device 401 in Fig. 11 has the same basic configuration as the defect detection device 400 in Fig. 9, but the method of applying an AC voltage for partial discharge detection is different. To distinguish it from the defect detection device 400 in Fig. 9, it is referred to as the defect detection device 401.
In the defect detection device 401 of FIG. 11, a power supply 46 and a partial discharge detection device 47 are directly connected to the clamp 45 to apply an AC voltage and detect partial discharge.

Next, the conductive liquid tank 41 will be described.
The conductive liquid tank 41 is made of an insulating material, and a material that is not dissolved by the conductive liquid 42 is selected. In this embodiment, a rectangular parallelepiped box shape with an open top is described, but any shape such as a cube, cylinder, or cone may be used as long as it can hold the conductive liquid 42. Also, in order to suppress evaporation of the conductive liquid 42 from the liquid surface, a float may be provided, or a lid may be provided on the top surface of the conductive liquid tank 41.

Here, the conductive liquid supply mechanism 450 of the magnet wire insulating coating inspection device 100 will be described with reference to FIG.
The wet electrode 43 must always be wet with the conductive liquid 42 during the inspection of the magnet wire 2. When a voltage is applied to the wet electrode 43 via the metal electrode 44, both ends of the wet electrode 43 must always be located below the surface of the conductive liquid 42. In order to maintain the liquid level, in addition to providing a float for suppressing evaporation as described above, it is effective to provide a conductive liquid refill mechanism 450 for refilling the conductive liquid tank 41 with the conductive liquid 42 as shown in FIG.

12, the conductive liquid supply mechanism 450 includes a liquid supply tank 51 and a liquid supply mechanism liquid tank 50 equipped with a valve 52. A liquid level switch 53 is provided in the conductive liquid tank 41, and a valve 52 is opened and closed by a signal from this liquid level switch 53.
Specifically, when the conductive liquid 42 in the conductive liquid tank 41 falls below a predetermined lower limit level, the valve 52 is opened and the conductive liquid 42 is supplied from the liquid supply tank 51 into the conductive liquid tank 41. When the conductive liquid 42 reaches an upper limit level, the valve 52 is closed to stop the supply of the conductive liquid 42.
A float type liquid level switch may be used instead of the electric liquid level switch.

In this way, by providing the conductive liquid supply mechanism 450, it is possible to continuously and stably supply the conductive liquid 42 to the wet electrode 43. As a result, the wet electrode 43 can be kept constantly wet, and partial discharge in the insulating coating of the magnet wire 2 can be stably detected by applying an AC voltage to the conductive liquid 42 or to the wet electrode 43 via the metal electrode 44.

The above has mainly described the configuration, functions, and operations of the inspection device for a magnet wire insulation coating according to embodiment 1. Here, a method for inspecting a magnet wire insulation coating will be described with reference to the flow chart of FIG.
In FIG. 13, the back tensioner load reproduction step is indicated as "BLS", the winding nozzle load reproduction step is indicated as "WNS", and the tension fluctuation load reproduction step is indicated as "TFS".

The process of the magnet wire insulating coating inspection method is composed of step 01 (S01) to step 07 (S07).
In step 01 (S01), it is selected whether or not to perform the back tensioner load reproduction step (S02). If the back tensioner load reproduction step (S02) is to be performed, the process proceeds to step 02 (S02), and if not, the process proceeds to step 03 (S03).

In the back tensioner load reproduction step (S02), the load caused by friction with the tensioner in the winding manufacturing process is reproduced. That is, a kinetic frictional force is applied to the passing magnet wire 2 to press it from both sides, thereby reproducing the load on the insulating coating caused by friction.
When the process of step 02 (S02) is completed, the process proceeds to step 03 (S03).

In step 03 (S03), select whether or not to perform the winding nozzle load reproduction step (S04). If the winding nozzle load reproduction step (S04) is to be performed, proceed to step 04 (S04); if not, proceed to step 05 (S05).

In the winding nozzle load reproduction step (S04), the load caused by friction with the winding nozzle in the winding manufacturing process is reproduced. That is, the load on the insulating coating caused by friction with the winding nozzle end during magnet wire winding is reproduced.
When the process of step 04 (S04) is completed, the process proceeds to step 05 (S05).

In step 05 (S05), select whether or not to perform the tension fluctuation load reproduction step (S06). If the tension fluctuation load reproduction step (S06) is to be performed, proceed to step 06 (S06); if not, proceed to step 07 (S07).

In the tension variation load reproduction step (S06), a load due to tension variation occurring when winding the magnet wire around a rectangular core in the winding manufacturing process is reproduced. That is, the load on the insulating coating due to tension variation is reproduced by generating periodic and steep tension variation in the movement path of the magnet wire 2.
When the process of step 06 (S06) is completed, the process proceeds to step 07 (S07).

In the defect detection step (S07), an AC voltage is applied between the conductor of the magnet wire and the surface of the insulating coating to detect partial discharges and thereby detect defects in the insulating coating of the magnet wire.

In the above description of the magnet wire insulation coating inspection method based on the flowchart of Fig. 13, a selection is made as to whether or not to perform each load reproduction step. However, in a normal inspection of the magnet wire 2, all the load reproduction steps are performed, and then the defect detection step is performed.
However, when inspecting a newly developed magnet wire or a magnet wire whose manufacturing process has been modified, it is sufficient to carry out any one, any two, or all of the load reproduction steps according to the load to be verified.

If the load caused by bending at the corners of the motor core when winding the magnet wire around the rectangular parallelepiped motor core is to be reproduced, a core corner load reproduction step can be added before the defect detection step (S07). In other words, the load on the insulating coating caused by bending at the corners of the motor core when winding the magnet wire is reproduced by generating periodic or continuous bending.

Next, an example of manufacturing a rotating electric machine using magnet wire 2 from the same lot as a magnet wire lot for which the inspection method for the magnet wire insulation coating has been applied and which has been found to have no problem with the tendency of occurrence of insulation coating defects due to winding load will be described with reference to FIG. 14.
FIG. 14 shows a method for manufacturing a rotating electric machine, which includes a step of manufacturing a rotating electric machine 80 having a stator core 72 wound with a nozzle 71 of a winding machine using a magnet wire 2 that has been determined to have no problem with the tendency of occurrence of insulation coating defects due to winding load by applying an inspection method for the magnet wire insulation coating.
In other words, this method of manufacturing a rotating electric machine makes it possible to manufacture a rotating electric machine that uses a magnet wire that has been inspected by a highly reliable inspection method for a magnet wire insulating coating.

This rotating electric motor 80 can also be manufactured by a method for manufacturing a rotating electric motor that includes a step of manufacturing a rotating electric motor using a stator core 72 wound with magnet wire 2 that has been determined to have no problem with the tendency for the occurrence of insulation coating defects due to winding load by applying an inspection device for the magnet wire insulation coating.

As described above, according to the winding load reproducing device of the first embodiment, it is possible to reproduce the load that the magnet wire insulating coating receives when a winding product is manufactured.
The magnet wire insulation coating inspection device can provide a device that reproduces the load that the magnet wire insulation coating receives when a winding product is manufactured and detects any defects that may occur in the insulation coating.
The method for inspecting magnet wire insulation coating can provide a method for reproducing the load that the magnet wire insulation coating experiences when a wound product is manufactured and detecting any defects that may occur in the insulation coating.
According to the manufacturing method of a rotating electric machine, a rotating electric machine can be provided that uses a magnet wire that has been inspected by an inspection method for a magnet wire insulation coating and that has been found to have no problem with the tendency of occurrence of insulation coating defects due to winding load.

Embodiment 2.
The magnet wire insulating coating inspection device of the second embodiment uses a wet electrode having a different form from that of the first embodiment.

The wet electrode of the magnet wire insulation coating inspection device of the second embodiment will be described with reference to FIGS. 15A and 16A which are structural diagrams of the wet electrode, and FIGS. 15B and 16B which are oblique views of the wet electrode, focusing on the differences from the first embodiment.
In the configuration diagram of the second embodiment, parts that are the same as or equivalent to those in the first embodiment are given the same reference numerals.
In each figure, the clamp and conductive liquid are omitted for clarity.

First, the U-shaped wet electrode 43C in Fig. 15A and Fig. 15B will be described. In the description, the U-shaped wet electrode 43C will be referred to as the wet electrode 43C.
The wet electrode 43 shown in Fig. 6 of the first embodiment is divided into two parts, wet electrode 43A and wet electrode 43B, which sandwich the magnet wire 2. However, it may have a shape like wet electrode 43C shown in Fig. 15A and Fig. 15B. Fig. 15A shows a front view of wet electrode 43C, and Fig. 15B shows a perspective view.

Wet electrode 43C is used in the form of a single long wet electrode having a rectangular parallelepiped shape, which is approximately twice as long as wet electrodes 43A and 43B shown in Fig. 6, bent at the top into a U-shape. The bent portion is formed to encase magnet wire 2.
As a result, the two parts extending from the bent U-shape come into contact with each other as shown in Fig. 15A. If wet electrode 43C can be formed in a similar shape, it is not necessary to form the electrode in the shape of a single long rectangular parallelepiped.

This configuration of the wet electrode 43C can eliminate the minute gaps that occur between the contact surfaces of the wet electrodes 43A and 43B shown in Figure 6 and the upper and lower surfaces of the magnet wire 2. This allows the conductive liquid 42 to come into contact with the surface of the magnet wire 2 more efficiently and reliably.

Next, the spiral wet electrode 43D of Fig. 16A and Fig. 16B will be described. In the description, the spiral wet electrode 43D will be referred to as the wet electrode 43D.
16A shows a front view of wet electrode 43D, and FIG. 16B shows a perspective view. Wet electrode 43D is a single long wet electrode having a length about 2.5 to 3 times that of wet electrodes 43A and 43B shown in FIG. 6, which is wound in a spiral shape around magnet wire 2, with both ends immersed in conductive liquid 42.

In the configuration of the wet electrode 43D, the minute gaps that occur between the contact surfaces of the wet electrodes 43A and 43B shown in Fig. 6 and the upper and lower surfaces of the magnet wire 2 can be eliminated over the entire circumference. Therefore, the conductive liquid 42 can be brought into contact with the surface of the magnet wire 2 more reliably than with the wet electrode 43 of embodiment 1 and the wet electrode 43C of Figs. 15A and 15B.

As for how the wet electrode 43D is wound around the magnet wire 2, as long as the entire circumference of the magnet wire 2 is in contact with the wet electrode 43D, there may be a gap between adjacent wet electrodes as shown in Fig. 16B. Also, the number of turns of the winding may be two or more.

As described above, the inspection device for a magnet wire insulating coating according to the second embodiment uses a wet electrode having a different form from that of the first embodiment.
Therefore, the magnet wire insulation coating inspection device of the second embodiment can reproduce the load that the magnet wire insulation coating receives when a winding product is manufactured, and detect defects in the insulation coating that occur. Furthermore, it is possible to reliably bring the conductive liquid into contact with the surface of the magnet wire.

Embodiment 3.
The defect detection device for the magnet wire insulating coating inspection device of the third embodiment uses dry electrodes instead of wet electrodes.

The configuration and operation of the defect detection apparatus of the third embodiment will be described with reference to FIG. 17 which is a configuration diagram of the defect detection apparatus, focusing on the differences from the first embodiment.
In the configuration diagram of the third embodiment, the same or corresponding parts as those in the first embodiment are denoted by the same reference numerals.
In order to distinguish it from the first embodiment, it is referred to as a defect detection device 410 .

A defect detection apparatus 410 in FIG. 17 is obtained by replacing the wet electrode 43 of the defect detection apparatus 400 in FIG. 6 with a dry electrode 60 and eliminating the conductive liquid tank 41.
A brush made of soft carbon and conductive polymer material that does not damage the enamel coating layer is used for the dry electrode 60. The material of the dry electrode 60 may also be a conductive sponge.
The dry electrode 60 is placed so that the tip of the brush is in contact with the surface of the magnet wire 2 .

In Figure 17, for the purpose of explanation, the brushes are arranged so that they sandwich the round magnet wire 2 from above and below, but in reality, the brush tips are arranged so that they are in contact all around the circumference. This is also true for rectangular magnet wire.

During partial discharge detection, when a defect in the insulating coating of the magnet wire 2 passes through the area of the dry electrode 60 to which a voltage is applied, a partial discharge occurs between the dry electrode 60 and the defect in the insulating coating, and is detected by the partial discharge detection device 47.
When detecting partial discharge, it is possible that the tip of the brush of the dry electrode 60 will momentarily separate from the surface of the magnet wire 2 while the magnet wire 2 is moving. However, if the distance is only a few mm, a partial discharge will occur between the insulating coating defect and the brush, even if the tip is not in direct contact with the surface of the magnet wire 2, and the defect can be detected.

When dry electrodes are used instead of wet electrodes in the defect detection device, the conductive liquid tank 41 and conductive liquid 42 are not required, and the liquid supply mechanism liquid tank 50 and related equipment for maintaining a constant level of conductive liquid 42 are also not required. This simplifies the equipment and makes it easier to operate the defect detection device.

As described above, the defect detection device of the magnet wire insulation coating inspection device of embodiment 3 uses dry electrodes instead of wet electrodes. Therefore, the magnet wire insulation coating inspection device of embodiment 3 can reproduce the load that the magnet wire insulation coating receives when manufacturing a wire product and detect defects in the insulation coating that occur. Furthermore, the defect detection device is simplified and operation is easier.

Although the present application describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations.
Therefore, countless modifications not illustrated are conceivable within the scope of the technology disclosed in the present application, including, for example, modifying, adding, or omitting at least one component, and further, extracting at least one component and combining it with a component of another embodiment.

The winding load reproduction device of the present application is equipped with a load reproduction mechanism that reproduces at least one load of friction or stretching on the insulating coating of a magnet wire, and simulates the occurrence of defects in the insulating coating of a magnet wire during the manufacture of winding products, and therefore can be widely applied to defect detection devices that detect defects in the insulating coating of magnet wire.

1 Supply bobbin, 2 Magnet wire, 3 Tensioner, 4 Winding bobbin, 5 Servo motor, 6A, 6B Traverse mechanism, 21 Round wire magnet wire, 21A, 22A Conductor, 21B, 22B Insulating coating, 22 Rectangular wire magnet wire, 31 Back tensioner, 32 Sapphire plate, 33 Winding nozzle, 34 Pulley, 35 Movable pulley, 36 Dummy core rotor, 37 Dancer roller, 38 Corner reproduction rotor, 39 Round corner reproduction rotor, 41 Conductive liquid tank, 42 Conductive liquid, 43A, 43B Wet electrode, 43C U-shaped wet electrode, 43D Spiral wet electrode, 44 Metal electrode, 45 Clamp, 46 Power source, 47 Partial discharge detection device, 48 Personal computer, 50 Liquid supply mechanism liquid tank, 51 Liquid supply tank, 52 valve, 53 liquid level switch, 60 dry electrode, 71 winding machine nozzle, 72 stator core, 80 rotating electric machine, 100 magnet wire insulation coating inspection device, 300 winding load reproduction device, 300A back tensioner load reproduction unit, 300B winding nozzle load reproduction unit, 300C tension fluctuation load reproduction unit, 300D core corner load reproduction unit, 400, 410 defect detection device, 450 conductive liquid supply mechanism.

Claims (21)

A load reproducing mechanism is provided for reproducing at least one load of friction or stretching on an insulating coating of a magnet wire, and the occurrence of defects in the insulating coating of the magnet wire during the manufacture of a winding product is simulated;
The load reproduction mechanism includes a back tensioner that clamps the magnet wire between multiple plates, and a back tensioner load reproduction unit that applies kinetic friction to the passing magnet wire and presses it from both sides to reproduce the load on the insulating coating due to friction. The winding load reproduction device according to claim 1, further comprising a hollow winding nozzle as the load reproduction mechanism, and a winding nozzle load reproduction section that reproduces the load on the insulating coating due to friction with the end of the winding nozzle when the magnet wire is wound, for the magnet wire passing through the inside of the winding nozzle. The winding load reproduction device according to claim 1 or 2, further comprising a tension fluctuation load reproduction unit that reproduces the load on the insulating coating due to tension fluctuations by generating periodic and steep tension fluctuations in the flow path of the magnet wire using the dummy core rotor as the load reproduction mechanism. The winding load reproduction device according to claim 1 or 2, which includes a rectangular parallelepiped corner reproduction rotor as the load reproduction mechanism, and a periodic bending core corner load reproduction unit that generates periodic bending at the points where the magnet wire's flow path is bent at right angles by the corner reproduction rotor, thereby reproducing the load on the insulating coating due to bending at the core corners. 3. The winding load reproduction device according to claim 1 or 2, further comprising a cylindrical round corner reproduction rotor as the load reproduction mechanism, and a continuous bending core corner load reproduction section which causes a continuous bending of the magnet wire at the points where the flow path of the magnet wire is bent at right angles by the round corner reproduction rotor, thereby reproducing the load on the insulating coating due to bending at the core corners. 3. A magnet wire insulation coating inspection device comprising: the winding load reproduction device according to claim 1 or 2; and a defect detection device for detecting defects in the insulation coating of the magnet wire. a load reproducing mechanism for reproducing at least one load of friction or stretching on an insulating coating of a magnet wire, and a winding load reproducing device for simulating the occurrence of defects in the insulating coating of the magnet wire in the manufacture of a winding product;
a defect detection device for detecting defects in the insulating coating of the magnet wire,
The defect detection device is an inspection device for magnet wire insulation coating that is impregnated with a conductive liquid in a conductive liquid tank and has an electrode formed so that the conductive liquid comes into contact with the periphery of the insulating coating of the magnet wire, applies a voltage between the conductive portion of the magnet wire and the electrode, measures the amount of discharge charge of partial discharge occurring between the magnet wire and the conductive liquid, and detects defects in the insulating coating of the magnet wire. An inspection device for magnet wire insulation coating as described in claim 7, wherein the electrode is a wet electrode made of a soft and hygroscopic material. The magnet wire insulation coating inspection device according to claim 8, which applies an AC voltage between the conductive portion of the magnet wire and the wet electrode. The magnet wire insulation coating inspection device according to claim 8, wherein the wet electrode contacts the surface of the conductive liquid and applies an AC voltage between the conductive portion of the magnet wire and the conductive liquid. The magnet wire insulation coating inspection device according to claim 10, wherein the conductive liquid tank is provided with a conductive liquid supply mechanism consisting of a liquid level switch, a supply tank for the conductive liquid, and a valve. An inspection device for magnet wire insulation coating according to any one of claims 8 to 11, in which the wet electrodes are two rectangular parallelepipeds arranged to sandwich the magnet wire. An inspection device for magnet wire insulation coating according to any one of claims 8 to 11, wherein the wet electrode is U-shaped and the bent portion for forming the U-shape is formed so as to contact the periphery of the magnet wire. An inspection device for magnet wire insulation coating according to any one of claims 8 to 11, wherein the wet electrode is formed so as to be wound around the magnet wire in a spiral shape. An inspection device for magnet wire insulation coating according to any one of claims 8 to 11, comprising a clamp that clamps the wet electrode from the outside. The magnet wire insulation coating inspection device according to claim 6, wherein the defect detection device is provided with a brush-shaped dry electrode made of a soft conductive material, applies an AC voltage between the conductive portion of the magnet wire and the dry electrode, measures the amount of discharge charge of partial discharge occurring between the magnet wire and the dry electrode, and detects defects in the insulation coating of the magnet wire. An inspection device for magnet wire insulation coating as described in claim 7, in which the electrode is a sponge electrode made of a soft and conductive material. 1. A method for detecting defects in an insulation coating of a magnet wire, comprising the steps of:
A magnet wire insulation coating inspection method comprising a back tensioner load reproduction step of applying a dynamic friction force to the magnet wire passing through a back tensioner that clamps the magnet wire between multiple plates, thereby reproducing the load on the insulation coating due to friction by pressing the magnet wire from both sides. a winding nozzle load reproducing step of reproducing a load on the insulating coating caused by friction with an end of the winding nozzle during winding of the magnet wire;
a tension fluctuation load reproducing step of reproducing a load on the insulating coating due to tension fluctuation by generating periodic and steep tension fluctuations in a flow path of the magnet wire;
a core corner load reproducing step of reproducing a load on an insulating coating caused by bending at a corner of a motor core during winding of the magnet wire by generating periodic or continuous bending at a point where a flow path of the magnet wire is bent at a right angle;
a defect detection step of detecting a defect in the insulating coating of the magnet wire;
20. The method of claim 18, further comprising: The magnet wire insulation coating inspection method according to claim 19, in which any one, any two, any three, or all of the back tensioner load reproduction step, the winding nozzle load reproduction step, the tension fluctuation load reproduction step, and the core corner load reproduction step are selected and performed according to the winding machine used. A method for manufacturing a rotating electric machine comprising the steps of manufacturing a rotating electric machine using a wound iron core using magnet wire from the same lot as the magnet wire that has been inspected using the magnet wire insulation coating inspection method described in claim 19 and found to have no problem with the tendency of occurrence of insulation coating defects in the magnet wire due to winding load.

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