JP2010210440A - Method and device for inspecting connection of motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the quality of a stator coil by efficiently finding out a stator whose connection state is imperfect by a non-destructive inspection method. <P>SOLUTION: This inspection method includes: a stage for preparing a stator 1 wherein core coils 3 provided respectively for a plurality of split cores 4 are connected with bus bars 2 (step S10); a stage for causing a current to flow into the core coil 3 of at least one split core 4 (step S20); a stage for measuring the temperature distribution of the split core 4 having the core coil 3 into which the current has been made to flow (step S30); a stage for recognizing whether or not the measured temperature distribution of the split core 4 is a temperature distribution within a predetermined temperature range (step S40); and a stage for determining that the connection states between the split core 4 and bus bars 2 are good when the temperature distribution of the split core 4 is within the temperature range, and that the connection states between the split core 4 and the bus bars 2 are not good when it is not within the temperature range (step S50). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a connection inspection method and a connection inspection apparatus for inspecting a connection failure of a motor.

  The concentrated winding motor is a direct-winding motor in which a core coil is directly wound around stator windings via stators (insulating material). The core coil is formed in advance by winding a plurality of divided core teeth through an insulator. A plurality of divided cores are assembled to form a stator. The motor is completed by combining a stator and a rotor.

  Here, when assembling a plurality of divided cores, the stator is formed through a plurality of steps. For example, as a plurality of processes, a plurality of divided cores are press-fitted and connected to form a stator. There is a step of attaching a bus bar to the core, fusing (connecting) each core coil of a plurality of divided cores, and impregnating the varnish.

  The prepared stator is subjected to an electrical property inspection and the like before the motor is completed by combining with the rotor. For example, in a method for inspecting the electrical characteristics of a three-phase stator coil, a test voltage is applied between U-V, V-W, and W-U of the stator coil, and the correspondence between the output voltage and the test voltage is examined. Thus, the connection mistake of the stator coil is inspected (see Patent Document 1).

JP 2001-289922 A

  However, only by applying a voltage between U-V, V-W, and W-U of the stator coil, only two types of inspections can be inspected: whether the connection is correct or not. That is, when the connection state is incomplete, it may be determined that the connection is made, and there is a problem that the incomplete motor is completed by combining with the rotor with insufficient inspection. Also, motors were tested at the shipping stage, and incomplete motors were discarded or repaired without passing the test by measuring the induced voltage and cogging torque.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a method for destructive inspection of a stator in which the connection state is incomplete at a stage after the connection where the divided core is mounted on the bus bar and connected. It is an object to provide a connection inspection device and a connection inspection method capable of efficiently finding out by a method that is not, and improving the quality of the stator coil.

  The connection inspection method of the present invention for achieving the above object is based on a step of preparing a stator in which a core coil is connected by a bus bar, a step of passing a current through the core coil, a step of measuring a temperature distribution of the core coil, and a measurement result. And determining the connection state.

  According to the present invention, it is possible to easily confirm the pass / fail of the connection state by passing a current through the divided cores constituting the core coil and measuring the temperature distribution due to heat radiation generated from the coils.

It is a flowchart figure which test | inspects the connection state of the connection part of the concentrated winding stator regarding this embodiment. It is the front view which shows the structure of the concentrated winding stator regarding this embodiment, and the schematic of a split core. It is a schematic diagram which shows the connection with a bus-bar and a split core. It is a schematic diagram of the terminal part of a bus bar. It is a schematic circuit diagram which shows the connection of 3 phases and a some division | segmentation core. It is the schematic which showed a mode that an electric current was sent through a division | segmentation core. It is the schematic which showed a mode that an electric current was sent through a concentrated winding stator. It is the schematic which showed the measurement of the temperature distribution of the division | segmentation core U1. It is the schematic which showed the measurement of the temperature distribution of U1-U8 of a split core. It is the schematic which showed the measurement of the temperature distribution of the core coil with which the concentrated winding stator was equipped. It is the figure of the reference experiment data which measured the temperature distribution of the division | segmentation core connected normally, and the division | segmentation core of poor connection. It is a flowchart figure which determines the connection state of a connection part based on an identification result.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments to which the invention is applied will be described with reference to the accompanying drawings.

  FIG. 1 is a flowchart for inspecting a connection state of a connection portion of a concentrated winding stator according to the present embodiment.

  First, the connection inspection method in this embodiment prepares a concentrated winding stator (step S1).

  FIG. 2 is a front view (a) showing the structure of the concentrated winding stator 1 according to the present embodiment and a schematic view (b) of the split core 4.

  The concentrated winding stator according to this embodiment is a part of a motor that is combined with a rotor (not shown) having a permanent magnet and is completed, and the connection inspection according to this embodiment is an inspection performed before being combined with the rotor. . Generally, a motor has a rotor disposed on the inner peripheral side of the stator, but this is not a limitation.

  As shown in FIG. 2A, the concentrated winding stator 1 is an annular stator, and the stator 1 is provided with a bus bar 2 including a plurality of electric wires for causing current to flow through the coil, and a core coil 3.

  The motor is driven by a plurality of n-phase alternating currents whose phases are shifted by 360 / n degrees. Here, a motor driven by a three-phase alternating current (U-phase current, V-phase current, and W-phase current) whose phases are shifted by 120 degrees will be described, but this is not restrictive.

  As shown in FIG. 2B, the split core 4 is formed by winding a coil 25 by concentrated winding via an insulator (insulating material) 24 so as to surround the extending direction of the teeth 23.

  Here, although the core coil 3 is arrange | positioned at the inner peripheral side of the bus-bar 2, it is not restricted to this, The core coil 3 may be arrange | positioned at the outer peripheral side of the bus-bar 2. Moreover, the core coil 3 can also be divided and created. Here, although the core coil 3 in which the 24 divided cores 4 are arranged at equal intervals in the circumferential direction will be described, this is not restrictive.

  FIG. 3 is a schematic diagram showing the connection between the bus bar and the split core. As shown in FIG. 3, the bus bar 2 is provided with a neutral wire LN, a U-phase wire LU, a V-phase wire LV, and a W-phase wire LW in order to flow a three-phase alternating current. Twenty-four divided cores 4 are respectively assigned to three-phase (U-phase, V-phase, W-phase) electric wires (U1-U8, V1-V8, W1-W8).

  Each divided core is connected and connected to a neutral wire of the bus bar and any one of three-phase electric wires belonging to each phase at a connection portion. For example, as shown in FIG. 3, U1 of the split core 4 is connected to the U-phase electric wire LU at the terminal C1 of the connection portion of the bus bar 2 and the neutral wire LN at the terminal C2 of the connection portion. Similarly, V1 of the split core 4 is connected to the V-phase electric wire LV at the terminal C3 of the connection portion of the bus bar 2 and the neutral line LN at the terminal C4 of the connection portion, and W1 of the split core 4 is connected to the connection portion of the bus bar 2. The terminal C5 is connected to the W-phase electric wire LW and the terminal C6 of the connection portion to the neutral wire LN.

  FIG. 4 is a schematic diagram of the terminal portion of the bus bar 2. (A) in FIG. 4 is a schematic diagram from the front, and (b) is a schematic diagram from the side. As shown in FIG. 4, a terminal protrudes from the bus bar, and an electric wire from the split core is installed and connected to a U-shaped hole. As a method for connecting the electric wire and the terminal, for example, the insulating coating of the electric wire is removed, and the terminal is pressurized to be caulked and brazed. It is also possible to solder instead of brazing. In addition, there can be mentioned many methods such as fusing in which a current is passed and crimped, but this is not restrictive.

  FIG. 5 is a schematic circuit diagram showing the connection between the three phases and the plurality of divided cores. Here, eight divided cores are connected in parallel, but this is not restrictive. As shown in FIG. 5, eight divided cores U1 to U8 are connected in parallel to the U phase and the neutral point. Similarly, eight divided cores V1 to V8 are connected in parallel to the V phase and the neutral point, and eight divided cores W1 to W8 are connected in parallel to the W phase and the neutral point. Connection between the split core 4 and the electric wire of the bumper is performed by a terminal provided in the bumper. The split core U1 is connected to a U-phase electric wire at a terminal C1 of the connection portion, and is connected to a neutral wire at a terminal C2 of the connection portion. Similarly, the split core V1 is connected to the V-phase electric wire at the terminal C3 of the connection portion and the neutral wire at the terminal C4 of the connection portion, and the split core W1 is connected to the V-phase electric wire and the terminal of the connection portion at the terminal C5 of the connection portion. Connected to neutral wire at C6. The other divided cores U2 to U8, V2 to V8, and W2 to W8 are similarly connected. Neutral lines are finally combined into one at the neutral point.

  Here, in general, when connecting the terminal provided on the bus bar and the electric wire from the coil in the connection portion with respect to the connection state, if the connection is normally performed, a contact resistance is not formed and the coil itself has. Only the resistor, that is, one resistor exists between the terminals (terminal-resistance (coil) -terminal). However, when the connection state is poor contact, the place has a resistance other than the coil (terminal-contact resistance-resistance (coil) -contact resistance-terminal) due to the contact resistance. Also, if the current is constant and current is applied between the terminals (for example, between the U phase and the neutral point), the contact resistance increases if the connection is inferior compared to the amount of heat generated from the coil that has been connected normally. The calorific value increases accordingly. Thus, even if the stator 1 has a plurality of phases, as long as the current wire of any phase and the core coil 3 of the split core 4 are connected in the bus bar 2 attached to the stator 1, the current is The connection state can be determined by measuring the temperature distribution of the flowing core coil 3.

  Usually, when the contact resistance is 0.01 mΩ or less, it is designed that the quality of the connected portion is good. For example, assuming that one split core coil is 100 mΩ, if there is a contact failure (about 0.1 mΩ) in two split core coils, the resistance value of the phase is about 12.516 mΩ. It becomes.

  In the connected state, as a defective state, there is a case where no connection is made in addition to the contact failure, that is, the connection is not performed. In the case of this unconnected, since no current flows through the coil, no heat is generated from the coil.

  Based on such a principle, the connection state between the coil and the bus bar terminal can be inspected based on heat generation by passing a current through the coil.

  Next, in the connection inspection method in the present embodiment, a current is passed through at least one divided core (step S20).

  FIG. 6 is a schematic diagram illustrating a state in which a current is passed through the split core. As shown in FIG. 6, current is passed through the split core U <b> 1 through current flowing between the U phase and the neutral point by energizing between A and B using an energization device (not shown). it can. Similarly, current can be passed through the other divided cores (U2 to U8). Moreover, it is also possible to energize a plurality of divided cores simultaneously or sequentially by installing an energizing device and a device having a switch function.

  FIG. 7 is a schematic diagram showing a state in which a current is passed through the concentrated winding stator. As shown in FIG. 7, by energizing the winding AB using an energizing device (not shown), the U phase-neutral point, the V phase-neutral point, and the W phase-neutral point are obtained. A current is allowed to flow through each of the divided cores, that is, the core coils 3. In addition, by installing a current-carrying device and a device having a switch function, it is possible to flow current to the split cores connected to the three phases by energizing the three phases simultaneously or sequentially. .

  Next, the connection inspection method in this embodiment measures the temperature distribution of the divided cores (step S30).

  FIG. 8 is a schematic diagram showing measurement of the temperature distribution of the split core U1. As shown in FIG. 8, the temperature distribution of the heat generated from the split core U1 is measured by passing a current through the split core U1. For example, a non-contact thermometer or thermography is used to measure. That is, in thermography, the temperature distribution can be measured by looking at the region R10 where the split core where current flows is located. In the non-contact thermometer, a plurality of points or surfaces of the core coil can be inspected to measure the temperature distribution in the region R10 where the split core where current flows is located.

  FIG. 9 is a schematic diagram showing measurement of the temperature distribution of U1 to U8 of the split core. In FIG. 8, the temperature distribution is measured by looking at the region R10 where the split core where the current flows is located using thermography, but the split core where the current flows is located using thermography as shown in FIG. The temperature distribution can also be measured by looking at the region R11. By energizing between A and B using the energization device, current flows from the divided cores U2 to U8 in addition to the divided core U1, and thus heat is generated from all the divided cores U1 to U8. Therefore, by energizing one phase of the stator, the temperature distribution of the plurality of divided cores can be measured at the same time by using the thermography to see the region R11 where the plurality of divided cores where current flows are located. . Here, the region R11 viewed by the thermography may consist of several screens instead of one screen.

  In addition, by recognizing the position of the workpiece and the position on the thermography in advance, it is possible to easily identify which divided core temperature distribution is being measured, thereby increasing the efficiency of the inspection work.

  FIG. 10 is a schematic diagram showing the measurement of the temperature distribution of the core coil 3 provided in the concentrated winding stator 1. As shown in FIG. 10, the region R12 viewed by thermography is set in the core coil 3 of the concentrated winding stator 1 in a state where current flows through the U phase-neutral point, the V phase-neutral point, and the W phase-neutral point. By doing so, the temperature distribution of all the divided cores can be measured. Further, by installing an energization device and a device having a switch function, it is possible to energize a plurality of divided cores simultaneously or sequentially and measure the temperature distribution of the target divided core.

  Next, the connection inspection method in the present embodiment identifies whether or not the temperature distribution is within a predetermined temperature range (step S40).

  FIG. 11 is a diagram of reference experiment data obtained by measuring the temperature distribution of the divided cores that are normally connected and the divided cores that are poorly connected. Here, a split core in which the terminal and the electric wire are completely bonded by welding is used as a normal product, and a split core in which the coating of the electric wire is removed and sandwiched between the terminals and pressed as a defective connection product, The temperature distribution was measured with constant flow. In other words, the electrical resistance of the defective connection product was increased from that of the normal product, and measurement was performed.

  As shown in FIG. 11, when the temperature distribution of the divided cores in which the connection was normally performed was measured, it was about 70 degrees, whereas when the divided cores with poor connection were measured, it was about 95 degrees. For example, when the temperature distribution of the split core single unit U1 is 75 degrees and the predetermined temperature range is 60 degrees to 90 degrees, the temperature distribution of the split core single unit U1 is identified as being within the predetermined temperature range, When the temperature distribution of another split core unit U2 is 95 degrees, it is identified that it is not within the predetermined temperature range. Here, when there was a difference of 0.01 mΩ in contact resistance, it was shown that a difference of exothermic temperature of 0.8 degree occurred in this system.

  In general, in order to prepare an output necessary for a motor, the configuration of the split core can take various forms such as the size of the core coil, the type of electric wire, and the number of windings. Therefore, the predetermined temperature range may be determined by measuring the temperature distribution of the divided cores that are determined to be normal in advance and determining the predetermined temperature range.

  In addition, a predetermined temperature range can be determined in advance by calculating the heat generation amount by inputting the configuration of the divided core into simulation software and creating a normal temperature distribution of the divided core.

  Furthermore, a predetermined temperature distribution may be created by analyzing data obtained by measuring the temperature distribution of a plurality of divided cores at the same time without preparing the predetermined temperature distribution in advance before measuring the temperature distribution of the divided cores. it can. For example, as shown in FIG. 9, the temperature distribution of the divided cores U1 to U8 is measured by looking at the region R11 by thermography, a distribution map is created based on the data of the eight temperature distributions, and a predetermined temperature range is determined. May be. Further, as shown in FIG. 10, the temperature distribution of all the divided cores is measured by looking at the region R12 by thermography, a distribution diagram is created based on the data of 24 temperature distributions, and a predetermined temperature range is determined. Also good.

  Finally, the connection inspection method in the present embodiment determines the connection state of the connection part based on the identification result (step S50).

  FIG. 12 is a flowchart for determining the connection state of the connection unit based on the identification result. As shown in FIG. 12, it is determined whether or not the temperature distribution of the divided cores is within a predetermined temperature range at the identification stage in step 40 (step S51). When the measured temperature distribution is within the predetermined temperature range (step S52), it is determined that the connection of the divided core is in a good state. On the other hand, when the temperature is not within the predetermined temperature range (step S53), it is determined that the connection of the divided core is in a defective state.

  According to the embodiment described above, the following effects are obtained.

  According to the present invention, it is possible to easily confirm the pass / fail of the connection state by passing a current through the divided cores constituting the core coil and measuring the temperature distribution due to heat radiation generated from the coils.

  Further, the temperature distribution of the coil of the split core can be easily measured by using a non-contact thermometer or thermography. Furthermore, by recognizing the position of the workpiece and the position on the thermography in advance, it is possible to easily identify which divided core temperature distribution is being measured, thereby increasing the efficiency of the inspection work.

  In addition, even if the stator has a plurality of phases, the temperature distribution of the core coil through which the current flows is maintained as long as the current lines of the respective phases and the core coil of the split core are connected in the bus par attached to the stator. The connection state can be determined by measuring.

  In addition, by energizing one phase of the stator, the temperature distribution of the plurality of divided cores can be measured simultaneously by looking at the region R11 where the plurality of divided cores where current flows is located using thermography. .

  Further, by installing an energization device and a device having a switch function, it is possible to energize a plurality of divided cores simultaneously or sequentially and measure the temperature distribution of the target divided core.

1 Concentrated winding stator,
2 Busbar,
3 core coil,
4 Split core.

Claims (6)

Preparing a stator in which a core coil provided in each of a plurality of divided cores is connected by a bus bar;
Passing a current through a core coil of at least one of the split cores;
Measuring a temperature distribution of a split core having a core coil through which the current flows;
Identifying whether the measured temperature distribution of the split core is a temperature distribution within a predetermined temperature range; and
When the temperature distribution of the split core is identified as being within the temperature range, the split core and the bus bar are connected in good condition, and when not within the temperature range, the split core and the bus bar are connected. Determining that it is wired in a defective state;
A connection inspection method comprising:   The connection inspection method according to claim 1, wherein the temperature distribution is measured by a non-contact thermometer or thermography.   The bus bar includes a neutral line and a current line corresponding to each phase for flowing current to each phase of the plurality of phases, and the plurality of divided cores correspond to any one of the plurality of phases. 3. The connection inspection method according to claim 1, wherein the core coil of the divided core is connected to the current wire of the phase divided so as to correspond to the neutral wire. 4.   4. The connection inspection method according to claim 1, wherein in the step of passing the current, a current is passed through at least one of the plurality of phases. 5.   5. The method according to claim 1, wherein in the step of passing the current, when a current is supplied to two or more phases of the plurality of phases, a current is supplied to the plurality of phases in order. The connection inspection method described in 1. Energizing means for passing current to the core coil of at least one of the divided cores of the stator in which a core coil provided in each of the divided cores is connected by a bus bar;
Measuring means for measuring a temperature distribution of a split core having a core coil through which the current flows;
Identifying means for identifying whether the measured temperature distribution of the divided core is a temperature distribution within a predetermined temperature range;
When the temperature distribution of the split core is identified as being within the temperature range, the split core and the bus bar are connected in good condition, and when not within the temperature range, the split core and the bus bar are connected. Determination means for determining that the connection is made in a defective state;
Connection inspection equipment consisting of

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