JP2018036164A - Method and device for examining insulation of coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method which can examine insulation of a coil in a reduced number of processes using vacuum discharge when the coil is still used as a product due to lack of significant quality problems.SOLUTION: In the method for examining isolation of coils, a direct voltage is applied between a coil 201 and an electrode 20 so that no currents larger than a preset limitation current value Iwill flow between the coil 201 and the electrode 20, and the size A of a scratch of the coil 201 is determined on the basis of the direct current V applied between the coil 201 and the electrode 20.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a coil insulation inspection method and a coil insulation inspection apparatus.

  2. Description of the Related Art Conventionally, a coil insulation inspection device that inspects a coil for damage is known (see, for example, Patent Document 1).

  Patent Document 1 discloses a coil insulation inspection apparatus that inspects a coil for flaws. In this coil insulation inspection apparatus, a coil is arranged in a chamber, an electrode is arranged at a position facing the coil, and a voltage is applied between the coil and the electrode in a state where the chamber is decompressed. When the coil has a flaw, a vacuum discharge is generated between the coil and the electrode, so that a current flows between the coil and the electrode. In this coil insulation inspection apparatus, the presence or absence of a scratch on the coil is determined by detecting the current flowing between the coil and the electrode.

Japanese Patent No. 4749416

  However, in the coil insulation inspection apparatus described in Patent Document 1, the presence or absence of a scratch on the coil is determined, but the size of the scratch on the coil is not determined. For this reason, in the coil insulation inspection apparatus described in Patent Document 1, other inspection methods such as measurement of leakage current by a salt water test, which is a kind of destructive inspection, are used in order to determine the size of the wound on the coil. In addition, there is a problem that the number of man-hours required for inspection increases. In addition, when determining the size of the wound of the coil by destructive inspection such as a salt water test, even if the size of the wound of the coil is a size that does not cause any quality problems, There is a problem that the coil needs to be discarded.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to use a wound-sized coil that does not have a quality problem as a product without being discarded. An object of the present invention is to provide a coil insulation inspection method and a coil insulation inspection apparatus capable of reducing the number of steps involved in inspection when inspecting a wound of a coil using vacuum discharge.

  To achieve the above object, a coil insulation inspection method according to a first aspect of the present invention provides a DC voltage between a coil and an electrode disposed at a position facing the coil in a decompressed inspection container. A method for inspecting insulation of a coil that is applied and discharged between the coil and the electrode, the coil and the electrode being arranged so that a current larger than a preset limit current value does not flow between the coil and the electrode. A direct current voltage is applied between the coil and the electrode, and the magnitude of the scratch on the coil is determined based on the direct current voltage value applied between the coil and the electrode.

  In the coil insulation inspection method according to the first aspect of the present invention, as described above, the size of the coil flaw is determined based on the DC voltage value applied between the coil and the electrode. Thereby, since the magnitude | size of the wound of a coil can be judged using vacuum discharge, it is not necessary to perform the other test | inspection method which can judge the magnitude | size of the wound of a coil further. As a result, when inspecting the wound of the coil using vacuum discharge, the number of man-hours related to the inspection can be reduced. Further, in the coil insulation inspection method of the present invention, since the size of the coil flaw can be determined using vacuum discharge, the size of the coil flaw can be determined by nondestructive inspection. Therefore, unlike the case where the size of the wound on the coil is judged by destructive inspection such as a salt water test, when the size of the wound on the coil can be determined to be a size with no problem in quality as a result of the inspection, The coil after the inspection can be used as a product without being discarded. This effect is particularly effective in that, for example, when an insulation inspection is performed for the stator of the rotating electrical machine including the coil, the stator of the rotating electrical machine including the coil after the inspection can be used as a product without being discarded.

  A coil insulation inspection apparatus according to a second aspect of the present invention includes a cuvette in which a coil can be arranged, an electrode that can be arranged at a position facing the coil arranged in the cuvette, and a reduced pressure that depressurizes the cuvette. And a DC power supply including a DC voltage control unit that controls to apply a DC voltage between the coil and the electrode so that a current larger than a preset limit current value does not flow between the coil and the electrode And a voltage detection unit for detecting a DC voltage value applied between the coil and the electrode, and a DC voltage value is acquired based on a detection result of the voltage detection unit, and the acquired DC voltage And a control unit that determines the size of the wound of the coil based on the value.

  In the coil insulation inspection apparatus according to the second aspect of the present invention, as described above, the control unit that acquires the DC voltage value and determines the size of the wound on the coil based on the acquired DC voltage value. Provide. As a result, as in the case of the coil insulation inspection method according to the first aspect, it is possible to reduce the number of man-hours related to the inspection when the wound of the coil is inspected using vacuum discharge. Further, in the coil insulation inspection apparatus according to the present invention, as in the case of the coil insulation inspection method according to the first aspect, when it is possible to determine that the wound on the coil is a scratch having no quality problem, the coil after the inspection is removed. It can be used as a product without being discarded. This effect is particularly effective in that, for example, when an insulation inspection is performed for the stator of the rotating electrical machine including the coil, the stator of the rotating electrical machine including the coil after the inspection can be used as a product without being discarded.

  According to the present invention, as described above, when the coil wound is inspected using vacuum discharge while being used as a product without discarding the coil having a scratch size that does not cause a problem in quality, the inspection is performed. It is possible to provide a coil insulation inspection method and a coil insulation inspection apparatus capable of reducing the number of steps.

It is a mimetic diagram showing an insulation inspection device of a coil by one embodiment of the present invention. It is a figure which shows the relationship between a DC voltage value and the magnitude | size of the damage | wound of a coil. It is a figure for demonstrating the time change of a DC voltage value, and the time change of a direct current value. It is a figure which shows the relationship between the direct-current voltage value applied between the electrode and the coil, and the direct-current value which flows between an electrode and a coil. It is a flowchart for demonstrating the coil damage | wound judgment process of the insulation test apparatus of the coil by one Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  With reference to FIGS. 1 to 4, an insulation inspection apparatus (hereinafter simply referred to as “insulation inspection apparatus”) 100 for a coil 201 according to an embodiment of the present invention will be described.

(Configuration of coil insulation inspection device)
As shown in FIG. 1, the insulation inspection apparatus 100 is an inspection apparatus that inspects a flaw of the coil 201 on which an insulating film is formed using vacuum discharge. Here, the scratches on the coil 201 are insulation defects such as pinholes and cracks generated in the insulating film. The insulation inspection apparatus 100 is configured to be able to inspect the scratches of the coil 201 disposed on the stator 300. Stator 300 includes a coil 201 and a stator core 202.

  The insulation inspection apparatus 100 includes an inspection container 10, an electrode 20, a vacuum pump 30, a DC power supply unit 40, a voltage detection unit 50, a current detection unit 60, and a control unit 70. The vacuum pump 30 is an example of the “decompression unit” in the claims.

  The cuvette 10 is an airtight container that can be decompressed, and is configured so that the stator 300 (coil 201) can be disposed therein.

  The electrode 20 may be disposed at a position facing the coil end 201a of the coil 201 disposed in the cuvette 10 in a state of being separated by a predetermined distance in order to generate a vacuum discharge with the coil 201. It is configured as possible.

  The electrode 20 is configured to be able to move along the outer peripheral surface of the coil 201 by a rotation driving unit (not shown) while maintaining a predetermined distance. Thereby, the insulation test | inspection apparatus 100 is comprised so that the damage | wound of the coil 201 in the arbitrary positions of the outer peripheral surface of the coil end 201a of the coil 201 can be test | inspected.

  The vacuum pump 30 is configured to depressurize the inside of the inspection container 10 to a predetermined inspection pressure (for example, 750 Pa) when inspecting the wound of the coil 201.

The DC power supply unit 40 includes a DC voltage application unit 41 and a DC voltage control unit 42. The DC voltage application unit 41 is configured to generate an arbitrary DC voltage and to apply an arbitrary DC voltage between the coil 201 and the electrode 20. The DC voltage control unit 42 controls the DC voltage application unit 41 so that a current larger than a preset limit current value I _L (for example, 1 mA) does not flow between the coil 201 and the electrode 20. In addition, it is configured to control to apply a DC voltage between the coil 201 and the electrode 20. Specifically, the DC voltage control unit 42, when a DC voltage is applied between the coil 201 and the electrode 20, if the limit current value I _L larger current flows than between the coil 201 and the electrodes 20 the, as current flows with limited current value I _L between the coil 201 and the electrodes 20, applying a DC voltage to be applied between the coil 201 and the electrode 20 (lowering) to perform the control It is configured. Further, the DC voltage control unit 42 acquires the DC current value I flowing between the coil 201 and the electrode 20 based on the detection result of the current detection unit 43 provided separately from the current detection unit 60, and based on the obtained DC current value I, and is configured to determine whether the current larger than the limit current value I _L between the coil 201 and the electrode 20 is flowing. The current detection unit 43 is connected to the electric wire 102 connected to the negative electrode side of the DC power supply unit 40 and is provided to detect the DC current value I flowing between the coil 201 and the electrode 20. .

  Further, the positive electrode of the DC power supply unit 40 is connected to the electrode 20 through the electric wire 101. In addition, the negative electrode of the DC power supply unit 40 is connected to the coil end 201 a of the coil 201 through the electric wire 102.

  The voltage detection unit 50 is provided to detect a DC voltage value V applied between the coil 201 and the electrode 20. Based on the detection result of the voltage detection unit 50, the control unit 70 is configured to acquire a DC voltage value V applied between the coil 201 and the electrode 20.

  The current detection unit 60 is connected to the electric wire 102 connected to the negative electrode side of the DC power supply unit 40 and is provided to detect the DC current value I flowing between the coil 201 and the electrode 20. . Based on the detection result of the current detection unit 60, the control unit 70 is configured to acquire a DC current value I flowing between the coil 201 and the electrode 20.

  The control unit 70 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and controls the operation of the insulation inspection apparatus 100 and determines the size A of the flaw of the coil 201. It is configured as follows. The control unit 70 is a circuit that controls the operation of the insulation inspection apparatus 100 and determines the size A of the flaw of the coil 201.

  The insulation testing apparatus 100 includes two power source protection resistors 81 and 82, two switch units 83 and 84, a current limiting resistor 85, and a capacitor 86.

  The power protection resistor 81, the power protection resistor 82, the switch unit 83, and the current limiting resistor 85 are provided on the electric wire 101. The switch unit 84 and the capacitor 86 are provided at positions where the electric wire 101 and the electric wire 102 are connected. The switch unit 83 is provided to switch application / non-application of the DC voltage supplied from the DC power supply unit 40 to the coil 201. The switch portion 84 is provided to release the electric charge accumulated in the circuit when the coil 201 is not damaged (when no vacuum discharge occurs between the coil 201 and the electrode 20). The current limiting resistor 85 is provided to limit the current flowing between the coil 201 and the electrode 20 outside the DC power supply unit 40. The capacitor 86 is provided for supplying electric charges when a transiently large current flows between the coil 201 and the electrode 20.

(Configuration related to determination of the size of coil scratches)
Here, in this embodiment, as shown in FIG. 2, the control unit 70 determines the scratch size A of the coil 201 based on the DC voltage value V acquired based on the detection result of the voltage detection unit 50. It is configured to judge.

  Specifically, the control unit 70 is based on the correlation (correlation formula F described later) between the DC voltage value V applied between the coil 201 and the electrode 20 and the size A of the scratch on the coil 201. In addition, the size A of the wound of the coil 201 is obtained. In the present embodiment, the correlation (correlation formula F) between the DC voltage value V and the scratch size A of the coil 201 is determined as follows, for example.

First, a correlation acquisition coil (not shown) having a known scratch size A is prepared. Then, the prepared correlation acquisition coil is arranged in the cuvette 10 and the electrode 20 is arranged at a position facing the scratch of the correlation acquisition coil. Then, the pressure in the cuvette 10 is reduced to the inspection pressure by the vacuum pump 30, and an initial DC voltage value V _I (for example, 1500 V) is set between the correlation acquisition coil and the electrode 20 by the DC power supply unit 40. DC voltage is applied.

Since the correlation acquisition coil is flawed, as shown in FIG. 3, a vacuum discharge occurs between the correlation acquisition coil and the electrode 20, and a current flows between the correlation acquisition coil and the electrode 20. Flowing. When a current larger than the limit current value I _L flows between the correlation acquisition coil and the electrode 20, the DC power supply unit 40 causes the limit current value I _L between the correlation acquisition coil and the electrode 20. The direct current voltage applied between the correlation acquisition coil and the electrode 20 is dropped so that a current having a current flows. As a result, the DC voltage applied between the correlation acquisition coil and the electrode 20 converges to a dropped DC voltage value V _D that has dropped from the initial DC voltage value V _I. In FIG. 3, such a waveform is shown as a voltage waveform W _V. Further, the direct current applied between the correlation acquisition coil and the electrode 20 converges to the limit current value I _L. In FIG. 3, such a waveform is shown as a current waveform W _I. Then, the voltage waveform W _V and the current waveform W _I are acquired in advance in the correlation acquisition coil having no flaw and the plurality of correlation acquisition coils having different flaw sizes.

FIG. 2 shows the relationship between the DC voltage drop V _D and the coil scratch size A in the correlation acquisition coil having no scratch and the plurality of correlation acquisition coils having different scratch sizes. In the correlation acquisition coil having no flaw, no voltage drop occurs, and therefore the drop DC voltage value V _D is substantially the same as the initial DC voltage value V _I.

As shown in FIG. 2, there is a correlation between the drop DC voltage value V _D and the scratch size A of the correlation acquisition coil. Specifically, there is a correlation in which the drop DC voltage value V _D decreases as the scratch size A of the correlation acquisition coil increases.

Therefore, based on the correlation between the drop DC voltage value V _D to the size A of the flaw correlation acquisition coil, a function of the drop DC voltage value V _D to the size A of the flaw correlation acquisition coil A certain correlation equation F can be obtained. FIG. 2 shows a plurality (five) of correlation equations F1 to F5 obtained when a plurality of (five) characteristic values are used as the drop DC voltage value V _D.

The correlation formula F1 is a correlation formula F obtained when the average value of the voltage values in the predetermined period T of the voltage waveform W _V is used as the dropped DC voltage value V _D. That is, the correlation formula F1 is a function of the average value of the voltage value in the predetermined period T of the voltage waveform W _V as the drop DC voltage value V _D and the size A of the scratch on the correlation acquisition coil.

Further, the correlation equation F2 is the correlation equation F obtained when the minimum value of the voltage value in the predetermined period T of the voltage waveform W _V is used as the dropped DC voltage value V _D. That is, the correlation equation F2 is a function of the minimum value of the voltage value in the predetermined period T of the voltage waveform W _V as the drop DC voltage value V _D and the scratch size A of the correlation acquisition coil.

Further, the correlation equation F3 is the correlation equation F obtained when the maximum value of the voltage value in the predetermined period T of the voltage waveform W _V is used as the drop DC voltage value V _D. That is, the correlation expression F3 is a function of the maximum value of the voltage value in the predetermined period T of the voltage waveform W _V as the drop DC voltage value V _D and the size A of the scratch on the correlation acquisition coil.

Further, the correlation equation F4 is a correlation equation F obtained when a value obtained by adding 4σ to the average value of the voltage values in the predetermined period T of the voltage waveform W _V is used as the dropped DC voltage value V _D. That is, the correlation formula F4 is obtained by adding 4σ to the average value of the voltage value in the predetermined period T of the voltage waveform W _V as the drop DC voltage value V _D , the flaw size A of the correlation acquisition coil, and Is a function of Here, σ is a cumulative value of the voltage value in the predetermined period T of the voltage waveform W _V.

Further, the correlation equation F5 is a correlation equation F obtained when a value obtained by subtracting 4σ from the average value of the voltage value in the predetermined period T of the voltage waveform W _V is used as the dropped DC voltage value V _D. That is, the correlation formula F5 is obtained by subtracting 4σ from the average value of the voltage value in the predetermined period T of the voltage waveform W _V as the drop DC voltage value V _D , the scratch size A of the correlation acquisition coil, and Is a function of

In this embodiment, it has been confirmed that in any of the correlation equations F1 to F5, there is a high correlation between the drop DC voltage value V _D and the scratch size A of the correlation acquisition coil.

Therefore, in the present embodiment, the control unit 70 uses the correlation equation F as a correlation between the DC voltage value V applied between the coil 201 and the electrode 20 and the size A of the scratch on the coil 201. In addition, the size A of the wound of the coil 201 is obtained. As described above, the correlation (correlation formula F) between the DC voltage value V and the flaw size A of the coil 201 is obtained with respect to the DC voltage value V _D acquired in advance for the correlation acquisition coil. This is determined based on the correlation with the size A of the wound of the coil for use.

  Any one of correlation equations F1 to F5 may be used as correlation equation F, but from the viewpoint of strictly managing the scratches on coil 201, the size A of the scratches on coil 201 is acquired the largest. It is preferable to use correlation formula F4.

In the present embodiment, the control unit 70 detects the voltage in the correlation equation F determined based on the DC voltage value V _D acquired in advance and the scratch size A of the correlation acquisition coil acquired in advance. By substituting the DC voltage value V of the coil 201 to be inspected (that is, the DC voltage value V _D of the coil 201 to be inspected) acquired based on the detection result of the unit 50, the size of the scratch on the coil 201 It is comprised so that A may be acquired. As the DC voltage value V to be substituted, a value corresponding to the characteristic value of the dropped DC voltage value V _D used in the correlation equation F may be used.

That is, when the correlation formula F1 is used, an average value of voltage values in a predetermined period T of the voltage waveform W _V measured in the coil 201 to be inspected may be used as the DC voltage value V to be substituted. Further, when the correlation equation F2 is used, the minimum value of the voltage value in the predetermined period T of the voltage waveform W _V measured in the coil 201 to be inspected may be used as the DC voltage value V to be substituted. When the correlation equation F3 is used, the maximum value of the voltage value in the predetermined period T of the voltage waveform W _V measured in the coil 201 to be inspected may be used as the DC voltage value V to be substituted. When the correlation equation F4 is used, a value obtained by adding 4σ to the average value of the voltage values in the predetermined period T of the voltage waveform W _V measured in the coil 201 to be inspected is used as the DC voltage value V to be substituted. Use it. When the correlation equation F5 is used, a value obtained by subtracting 4σ from the average value of the voltage values in the predetermined period T of the voltage waveform W _V measured in the coil 201 to be inspected is used as the DC voltage value V to be substituted. Use it.

In addition, the control unit 70 cannot use the coil 201 when the acquired scratch size A of the coil 201 is equal to or larger than the scratch size A _a of the coil 201 that is determined to be unusable. It is comprised so that it may be notified.

Further, when the acquired scratch size A of the coil 201 is smaller than the scratch size A _a of the coil 201 in which the coil 201 is determined to be unusable, the control unit 70 The position and the acquired size A of the wound of the coil 201 are informed. Thus, the inspector estimates whether the coil 201 is damaged in any of the manufacturing steps of the stator 300 based on the notified position of the wound on the coil 201 and the size A of the wound on the coil 201. Is possible.

Further, in the present embodiment, as shown in FIG. 2, in the region R1 where the scratch size A of the correlation acquisition coil is relatively small, the region R2 where the scratch size A of the correlation acquisition coil is relatively large. As compared with the above, the obtained value of the drop DC voltage value V _D varies greatly. For this reason, when the correlation equation F is used, it is considered that the scratch size A of the coil 201 may not be obtained with high accuracy when the scratch size A of the coil 201 is relatively small.

  Therefore, in the present embodiment, the control unit 70 adds the DC current value I acquired based on the detection result of the current detection unit 60 in addition to the DC voltage value V acquired based on the detection result of the voltage detection unit 50. Also based on the above, the size A of the wound of the coil 201 is determined. Specifically, the control unit 70 determines whether or not the wound of the coil 201 is a relatively small scratch based on the DC current value I acquired based on the detection result of the current detection unit 60. It is configured. This point will be described with reference to FIG.

In FIG. 4, a correlation acquisition coil having no flaw, a correlation acquisition coil having a flaw size A1, a correlation acquisition coil having a flaw size A2, and a correlation acquisition coil having a flaw size A3 The relationship between a voltage value and a current value in a coil, a correlation acquisition coil having a scratch size A4, and a correlation acquisition coil having a scratch size A5 is shown. As the voltage value, an average value of voltage values in a predetermined period T of the voltage waveform W _V is used. Further, as the current value, an average value of current values in a predetermined period T of the current waveform W _I is used. Further, the scratch sizes A1, A2, A3, A4, and A5 are larger in this order. The scratch size A1 is the size of the scratch corresponding to the size of the scratch in the region R1 (see FIG. 2). Also, flaw size A1 is a magnitude of the wound coil 201 is determined to be used, is the size of smaller wounds than wounds magnitude A _a coil 201 is determined to be unusable . The scratch size A1 is an example of the “first scratch size” in the claims.

As shown in FIG. 4, the correlation acquisition coil having a flaw sizes A2 to A5, generally, it has a current value smaller than the limit current value I _L. On the other hand, the correlation acquisition coil having a flaw size A1, and has a current value greater than the limit current value I _L. This is because the correlation acquisition coil having a relatively small flaw size A1, since it is possible to compensate for the charge by the charge supplied from the capacitor 86, is a current value greater than transiently limit current value I _L while the resulting, in correlation acquisition coil having a magnitude A2~A5 relatively large wounds, since the only charge supplied from the capacitor 86 not be compensated charge, and a current value smaller than the limit current value I _L This is thought to be because of

Therefore, in the present embodiment, the control unit 70 is larger threshold value Th1 or more than the detection result direct current value I acquired on the basis of the limit current value I _L of the current detector 60, a coil It is configured to determine that the size A of the scratch 201 is equal to or less than the size A1 of the scratch.

  In the present embodiment, when the acquired DC current value I is smaller than the threshold value Th1, the control unit 70 determines the size of the scratches on the coil 201 based on the DC voltage value V as described above. It is comprised so that A may be judged.

  In the present embodiment, the control unit 70 is configured to determine whether or not the coil 201 is damaged based on the acquired direct current value I. Specifically, when the acquired DC current value I is smaller than a threshold value Th2 (for example, 0.1 mA) for determining whether or not a current has occurred, the control unit 70 determines that the coil 201 It is configured to judge that there is no scratch. Further, when it is determined that the coil 201 is not damaged, the control unit 70 is configured to notify that the coil 201 can be used without determining the size A of the wound of the coil 201. ing.

  Further, the control unit 70 is configured to determine that the coil 201 is damaged when the acquired DC current value I is equal to or greater than a threshold value Th2 for determining whether or not a current has occurred. Has been. Further, when it is determined that the coil 201 has a flaw, the control unit 70 is configured to determine the flaw size A of the coil 201 based on the DC voltage value V as described above. Yes.

(Coil wound judgment processing)
Next, with reference to FIG. 5, the coil damage determination processing by the insulation inspection apparatus 100 of the present embodiment will be described based on a flowchart. Each process of the flowchart is executed by the control unit 70.

  First, the stator 300 (coil 201) is disposed in the cuvette 10, and the electrode 20 is disposed at a position facing the coil end 201a of the coil 201. Then, as shown in FIG. 5, in step S <b> 1, the inside of the cuvette 10 is decompressed to the inspection pressure by the vacuum pump 30.

In step S <b> 2, a DC voltage having an initial DC voltage value V _I is applied between the coil 201 and the electrode 20 by the DC power supply unit 40.

  In step S <b> 3, the DC voltage value V applied between the coil 201 and the electrode 20 is acquired based on the detection result of the voltage detection unit 50, and based on the detection result of the current detection unit 60. The DC current value I flowing between the coil 201 and the electrode 20 is acquired.

  In step S4, it is determined whether or not the direct current value I acquired in step S3 is equal to or greater than a threshold value Th2 for determining whether or not a current has occurred. If it is determined that the direct current value I is smaller than the threshold value Th2, it is considered that no vacuum discharge has occurred between the coil, 201, and the electrode 20, so the process proceeds to step S5.

  In step S5, it is determined that the coil 201 is not damaged.

  In step S6, it is notified that the coil 201 can be used. Thereafter, the coil flaw determination process is terminated.

  If it is determined in step S4 that the direct current value I is equal to or greater than the threshold value Th2, it is considered that no vacuum discharge has occurred between the coil 201 and the electrode 20, and therefore, the process proceeds to step S7. move on.

  In step S7, it is determined that the coil 201 is damaged.

Then, in step S8, the DC current value I acquired in step S3 is is determined whether or not the larger threshold value Th1 or more than the limit current value I _L. If it is determined that the DC current value I is equal to or greater than the threshold value Th1, the process proceeds to step S9.

  In step S9, it is determined that the scratch size A of the coil 201 is equal to or smaller than the scratch size A1. Since the scratch size A1 is the size of the scratch for which it is determined that the coil 201 can be used, the process advances to step S6 to notify that the coil 201 can be used. Thereafter, the coil flaw determination process is terminated.

  If it is determined in step S8 that the direct current value I is smaller than the threshold value Th1, the process proceeds to step S10.

  In step S10, it is determined that the scratch size A of the coil 201 is larger than the scratch size A1.

  In step S11, the scratch size A of the coil 201 is acquired based on the correlation equation F.

In step S12, it is determined whether or not the scratch size A of the coil 201 acquired in step S11 is greater than or equal to the scratch size A _a of the coil 201 that is determined to be unusable. . If the flaw size A of the coil 201 is determined to be wound size A _a or more, the process proceeds to step S13.

  In step S13, it is notified that the coil 201 cannot be used. Thereafter, the coil flaw determination process is terminated.

Further, in step S12, if the flaw size A of the coil 201 is determined to be smaller than the scratch size A _a, the process proceeds to step S14.

  In step S14, the position of the wound on the coil 201 and the size A of the wound on the coil 201 are notified. Thereafter, the coil flaw determination process is terminated.

(Effect of this embodiment)
In the present embodiment, the following effects can be obtained.

  In the present embodiment, as described above, the DC voltage value V applied between the coil 201 and the electrode 20 is acquired, and the scratch size A of the coil 201 is determined based on the DC voltage value V. The control unit 70 is configured as described above. Accordingly, since the size A of the scratch on the coil 201 can be determined using vacuum discharge, it is not necessary to further perform another inspection method capable of determining the size A of the scratch on the coil 201. As a result, when the wound of the coil 201 is inspected using vacuum discharge, the number of man-hours related to the inspection can be reduced. In the present embodiment, since the size A of the scratch on the coil 201 can be determined using vacuum discharge, the size A of the scratch on the coil 201 can be determined by nondestructive inspection. Therefore, unlike the case where the size A of the wound of the coil 201 is determined by a destructive inspection such as a salt water test, the size of the wound of the coil 201 can be determined to be a size having no quality problem as a result of the inspection. The coil 201 after the inspection can be used as a product without being discarded. This effect is particularly effective in that when the insulation inspection is performed for the entire stator 300 including the coil 201 as in the present embodiment, the stator 300 after the inspection can be used as a product without being discarded.

In the present embodiment, as described above, when a DC voltage is applied between the coil 201 and the electrode 20, a current larger than the limit current value I _L flows between the coil 201 and the electrode 20. The DC voltage control unit 42 is controlled so that a DC voltage is applied between the coil 201 and the electrode 20 so that a current having a limit current value I _L flows between the coil 201 and the electrode 20. Configure. As a result, the lowered DC voltage value V can be set to a substantially constant value, so that the size A of the flaw of the coil 201 can be easily determined based on the DC voltage value V.

In the present embodiment, as described above, the flaw of the coil 201 is based on the correlation between the DC voltage value V applied between the coil 201 and the electrode 20 and the flaw size A of the coil 201. The control unit 70 is configured to acquire the size A. Then, for the correlation acquisition coil, the correlation is such that the DC voltage value V _D dropped with respect to the initial DC voltage value V _I acquired in advance and the scratch size of the correlation acquisition coil acquired in advance. Based on A. Thus, the scratch size A of the coil 201 can be accurately acquired using the correlation between the DC voltage value V _D having a large correlation and the scratch size A of the correlation acquisition coil. it can.

Further, in the present embodiment, as described above, the correlation equation F determined based on the DC voltage value V _D acquired in advance and the scratch size A of the correlation acquisition coil acquired in advance, By substituting the DC voltage value V, the control unit 70 is configured to acquire the size A of the wound of the coil 201. Thereby, compared with the case where the conversion table of DC voltage value V and the magnitude | size A of the wound of the coil 201 is used, the magnitude | size A of the wound of the coil 201 can be acquired finely. As a result, the size A of the scratch on the coil 201 can be determined finely.

In the present embodiment, as described above, when a DC voltage is applied between the coil 201 and the electrode 20, a charge is supplied when a transient current flows between the coil 201 and the electrode 20. A capacitor 86 is provided. When the direct current value I is equal to or greater than the threshold value Th1 that is greater than the limit current value I _L , the control unit 70 determines that the scratch size A of the coil 201 is equal to or less than the scratch size A1. Configure. As a result, even when the scratch size A of the coil 201 that is difficult to determine with the DC voltage value V is relatively small, the scratch size A of the coil 201 can be accurately determined based on the DC current value I. it can.

  In the present embodiment, as described above, when the direct current value I is smaller than the threshold value, the control unit 70 determines the scratch size A of the coil 201 based on the direct current voltage value V. Configure. As a result, when the scratch size A of the coil 201 that is easy to determine based on the DC voltage value V is relatively large, the scratch size A of the coil 201 can be accurately determined based on the DC voltage value V. it can.

  Further, in the present embodiment, as described above, based on the direct current value I, it is determined whether or not the coil 201 is damaged, and when it is determined that the coil 201 is not damaged, If it is determined that the coil 201 is scratched without determining the magnitude A, the controller 70 is configured to determine the scratch size A of the coil 201 based on the DC voltage value V. To do. Thereby, since the magnitude | size A of the damage | wound of the coil 201 is judged only when there exists a damage | wound of the coil 201, the coil 201 can be test | inspected efficiently. Further, since the presence / absence of a flaw in the coil 201 is determined based on the DC current value I, the value of which varies greatly depending on whether the coil 201 is flawed or not as compared with the DC voltage value V. Can be accurately determined.

[Modification]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the said embodiment, although the example which test | inspects the coil of a stator with the insulation test | inspection apparatus was shown, this invention is not limited to this. In this invention, you may test | inspect other members and apparatuses containing coils other than a stator with an insulation test | inspection apparatus. For example, a rotor coil or a solenoid coil may be inspected. Moreover, you may test | inspect a coil alone with an insulation test | inspection apparatus.

  Moreover, although the control part acquired the magnitude | size of the damage | wound of a coil by substituting a direct-current voltage value to a correlation type in the said embodiment, this invention is not limited to this. In the present invention, the control unit may acquire the size of the wound on the coil by a method other than substituting the DC voltage value into the correlation equation. For example, a database that records the correlation between the DC voltage value and the coil scratch size may be further provided, and the control unit may acquire the coil scratch size from the database based on the DC voltage value.

  Moreover, although the control part determined the magnitude | size of the damage | wound of a coil based on a direct current value in addition to a direct current voltage value in the said embodiment, this invention is not limited to this. In the present invention, if it is possible to determine the size of the scratch on the coil, the control unit may determine the size of the coil on the basis of only the DC voltage value.

  Moreover, although the control part determined the presence or absence of the damage | wound of a coil based on a direct current value in the said embodiment, this invention is not limited to this. In the present invention, the control unit may determine whether or not the coil is damaged based on the DC voltage value.

  Moreover, although the control part alert | reported that a coil is usable or unusable etc. was shown in the said embodiment, this invention is not limited to this. In the present invention, the control unit does not need to notify that the coil is usable or unusable. For example, the control unit may simply notify the size of the wound on the coil.

  Moreover, although the insulation test | inspection apparatus showed the example provided with the resistance for power supply protection, the switch part, the resistance for electric current limitation, and the capacitor | condenser in the said embodiment, this invention is not limited to this. In the present invention, the insulation inspection device may not include the power source protection resistor, the switch unit, the current limiting resistor, and the capacitor.

  Moreover, in the said embodiment, although the process operation | movement of the control part was demonstrated using the flow drive type flowchart which processes in order along a process flow for convenience of explanation, this invention is not limited to this. In the present invention, the processing operation of the control unit may be performed by event-driven (event-driven) processing that executes processing in units of events. In this case, it may be performed by a complete event drive type or a combination of event drive and flow drive.

10 Inspection container 20 Electrode 30 Vacuum pump (decompression unit)
DESCRIPTION OF SYMBOLS 40 DC power supply part 41 DC voltage application part 42 DC voltage control part 50 Power supply detection part 70 Control part 100 Insulation inspection apparatus of coil 201 Coil

Claims (10)

This is a method for inspecting insulation of a coil in which a DC voltage is applied between a coil and an electrode disposed at a position opposite to the coil in a depressurized cuvette to discharge between the coil and the electrode. And
Applying the DC voltage between the coil and the electrode so that a current larger than a preset current limit value does not flow between the coil and the electrode,
A method for inspecting insulation of a coil, wherein the magnitude of a flaw in the coil is determined based on a DC voltage value applied between the coil and the electrode.   Applying the DC voltage between the coil and the electrode means that when the DC voltage is applied between the coil and the electrode, the limit current value is applied between the coil and the electrode. Applying a DC voltage between the coil and the electrode so that a current having the limit current value flows between the coil and the electrode when a larger current flows. Item 2. A coil insulation inspection method according to Item 1. The determination of the size of the coil scratch is based on the correlation between the DC voltage value applied between the coil and the electrode and the size of the coil scratch. Including getting the size,
The correlation is based on the DC voltage value dropped with respect to the initial DC voltage value acquired in advance for the correlation acquisition coil and the size of the scratch on the correlation acquisition coil acquired in advance. The insulation test method for a coil according to claim 1 or 2, wherein the insulation test method is determined.   Obtaining the size of the scratch on the coil based on the correlation is determined based on the DC voltage value acquired in advance and the size of the scratch on the correlation acquiring coil acquired in advance. The insulation test method for a coil according to claim 3, further comprising: acquiring a magnitude of a scratch on the coil by substituting the DC voltage value into a correlation equation. Further acquiring a direct current value flowing between the coil and the electrode,
Determining the size of the scratch on the coil means that the size of the scratch on the coil is equal to or less than the size of the first scratch when the direct current value is greater than or equal to a threshold value greater than the limit current value. The insulation test method for a coil according to any one of claims 1 to 4, comprising determining that the coil is.   Determining the size of the coil scratch includes determining the size of the coil scratch based on the DC voltage value when the DC current value is smaller than the threshold value. The coil insulation inspection method according to claim 5.   Determining the size of the scratch on the coil is based on the direct current value, determining whether or not the coil is scratched, and if it is determined that the coil is not scratched, If it is determined that the coil is damaged without determining the size of the coil, the method includes determining the size of the coil based on the DC voltage value. The insulation test method of the coil as described in 2. A cuvette in which a coil can be placed;
An electrode that can be disposed at a position facing the coil disposed in the cuvette;
A decompression section for decompressing the inside of the cuvette;
By controlling the DC voltage application unit that applies a DC voltage between the coil and the electrode, and by controlling the DC voltage application unit, a current larger than a preset limit current value is generated between the coil and the electrode. A direct-current power supply unit including a direct-current voltage control unit that performs control to apply the direct-current voltage between the coil and the electrode so as not to flow between them;
A voltage detection unit for detecting a DC voltage value applied between the coil and the electrode;
A control unit that acquires the DC voltage value based on the detection result of the voltage detection unit and determines the size of the scratch on the coil based on the acquired DC voltage value. Insulation inspection equipment.   When the DC voltage is applied between the coil and the electrode, and the current greater than the limit current value flows between the coil and the electrode, the DC voltage control unit 9. The control according to claim 8, wherein control is performed to apply the DC voltage between the coil and the electrode so that a current having a current value flows between the coil and the electrode. Coil insulation inspection device.   The capacitor further includes a capacitor for supplying a charge when a current flows transiently between the coil and the electrode when the DC voltage is applied between the coil and the electrode. Or the coil insulation inspection device according to 9.

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