JP2014135819A - Method of manufacturing stator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a stator which can secure bond strength of a coil terminal by setting positional accuracy at a tip of a coil terminal within a predetermined reference value in a stator having a plurality of U-shape segment coils consisting of rectangular wires.SOLUTION: A method of manufacturing a stator 1 includes an inspection process for determining quality of positional accuracy by measuring each coil terminal position with image measurement before in-phase coil terminals Sga are bonded, after a U-shape segment coil is assembled to a stator core 2 in a stator 1 having a plurality of U-shape segment coils consisting of rectangular wires. The inspection process determines quality of positional accuracy by calculating the center position of a tip Sga11 in each coil terminal Sga from data obtained by performing image measurement to the outer shape of a coil conductor part Sga1 from which insulation coating is peeled in a coil terminal Sga.

Description

  The present invention relates to a method for manufacturing a stator in a motor. In particular, the present invention relates to a stator manufacturing method including an inspection step of measuring and determining a coil terminal position by image measurement after a plurality of segment coils are assembled to a stator core.

In general, a stator of a motor having a plurality of segment coils is formed by inserting a segment coil from which the insulating coating of the coil end has been peeled in advance into a slot of the stator core, and superimposing coils of the same phase on the coil end, Are manufactured by welding or the like. However, after each segment coil is inserted into the stator core, the coil terminal is twisted in the circumferential direction along the end of the stator core in order to overlap the coils in the same phase with the coil terminal. Therefore, in order to ensure the bonding strength at the tip end of the coil end, before joining by welding or the like, the circumferential and radial positions and the axial height of the tip end at each coil end are a predetermined reference value. It is necessary to keep it in.
Therefore, in the stator manufacturing method, an inspection technique for accurately measuring the positions of a plurality of coil terminals and determining the quality is required.
Here, Patent Document 1 discloses an inspection method for measuring the outer shape of the coil end of the stator coil by image measurement and determining the quality of the shape.
In addition, although the inspection object is not a stator coil, an alignment mark formed at the corner corner of the substrate is used for inspecting misalignment of the polarizing plate formed on the TFT array substrate and the color filter substrate constituting the liquid crystal panel. Patent Document 2 discloses a method of measuring an image of an edge line of a polarizing plate and determining a shift amount of a point at which the edge line is orthogonal to the alignment mark.

JP 2010-169450 A JP 2007-212939 A

However, the technique of Patent Document 1 is an optical cutting method that acquires a two-dimensional image (a cross-sectional image of a coil end) that is a captured image of reflected light obtained by irradiating a coil end with slit light from a laser projection unit or the like. It is. When the cross-sectional shape of the tip portion of the coil terminal is measured by this optical cutting method, the boundary line of the position where the coil terminals are close to or in contact with each other becomes unclear, and it is difficult to accurately determine the position of each coil terminal. Met.
Further, as in the technique of Patent Document 2, it is difficult to form the alignment mark at the tip of the coil terminal because the manufacturing process of the segment coil is complicated.
On the other hand, even if the alignment mark is not formed at the tip of the coil terminal, in image measurement, depending on the surface properties of the conductor part from which the insulating film has been peeled off at the coil terminal, how the lighting is applied to the conductor part and the insulating film part, etc. The measurement range setting (position, angle, etc.) for the coil terminal varies. If there is variation in the measurement range setting, the detection range of the outer shape of the conductor part will shift, and the coil terminal position is calculated based on that information, so the required position accuracy for the coil terminal cannot be ensured. There was a problem.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a predetermined reference value for the positional accuracy at the tip of the coil terminal in a stator having a plurality of U-shaped segment coils made of rectangular wires. It is to provide a method for manufacturing a stator that can be accommodated inside and ensure the strength of joining of coil terminals.

In order to solve the above problems, a stator manufacturing method according to the present invention has the following configuration.
(1) In a stator having a plurality of U-shaped segment coils made of rectangular wires, after assembling the U-shaped segment coils to the stator core, each coil terminal position is measured by image measurement before joining the coil terminals of the same phase. Is a method for manufacturing a stator comprising an inspection step of measuring the position accuracy and determining the quality of the position accuracy,
The inspection step calculates the center position of the tip of each coil terminal from data obtained by image measurement of the outer shape of the coil conductor part from which the insulating coating has been peeled off at the coil terminal, and determines whether the position accuracy is good or bad. Features.

In the present invention, the inspection step calculates the center position of the tip of each coil terminal from the data obtained by image measurement of the outer shape of the coil conductor part from which the insulating coating has been peeled off at the coil terminal, and determines the quality of the position accuracy. Therefore, it is possible to ensure the bonding strength of the coil terminal by keeping the positional accuracy at the tip of the coil terminal within a predetermined reference value.
That is, by calculating the center position of the tip portion at each coil terminal, whether or not the circumferential position and the radial position of the tip portion at each coil terminal are within a predetermined reference value is joined by welding or the like. Since it can confirm previously, joining by welding etc. of a coil end can be performed appropriately, and required joining strength can be ensured.
Moreover, since the external shape of the coil conductor part from which the insulating coating has been peeled is image-measured, the contours of the coil terminals do not overlap by separating at least the thickness of the peeling insulating coating. Therefore, the error of the image data is small and the coil terminal position can be determined with high accuracy.

(2) In the stator manufacturing method described in (1),
The inspection step is provided both before and after the coil terminal is twisted in the circumferential direction along the end of the stator core.

  In the present invention, the inspection step is provided both before and after the coil terminal is twisted in the circumferential direction along the end of the stator core. It is possible to guarantee the positional accuracy before the twist forming, and to reduce the variation in the position of the tip of the coil terminal after the twist forming. Therefore, the joining strength of the coil terminal can be more easily ensured.

(3) In the stator manufacturing method described in (1) or (2),
Image measurement is performed by selecting a range for each of two locations on the long side and the short side of the outer shape of the coil conductor portion, and the position of two points on the long side and two points on the short side from the measured image data Calculating the position of
Calculating four intersecting positions where straight lines passing through the positions of the two points intersect,
The position where two diagonal lines passing through the intersecting position intersect is calculated as the center position of the tip of each coil terminal.

In the present invention, two long positions and short sides in the outer shape of the coil conductor portion are selected and image measurement is performed by selecting a range for each of two locations, and the positions and short sides of the two points on the long side from the measured image data Since the position of the upper two points is calculated, by selecting two image measurement ranges, the light disturbance factor is reduced, and errors in the positions of the two points on the long side and short side to be calculated are reduced. Can be reduced.
In addition, since the four intersecting positions where the straight lines passing through the respective two points intersect are calculated, and the position where the two diagonal lines passing through the intersecting positions intersect is calculated as the center position of the tip of each coil terminal, A virtual quadrangle having four intersection positions as vertices is formed, and a position obtained by dividing the two diagonals of the virtual quadrant into two equals is the center position of the tip of each coil terminal. Therefore, even if the virtual quadrangle forms a rectangle, a square, a rhombus, or a parallelogram, etc., the center position of the tip of each coil terminal is the same position from the opposite vertex, and the coil terminal position is more accurate. Can be judged well.

(4) In the stator manufacturing method described in (3),
The length of each side constituting the virtual quadrangle having the four intersecting positions as vertices, or the inner angle (first inner angle) of the vertex at which each side intersects, the length of each diagonal line connecting the opposite vertices of the virtual quadrangle, When at least one of the inner angles (second inner angles) of the intersections where the diagonal lines intersect is not within the range of the respective reference values, the image is measured again and recalculated.

  In the present invention, the length of each side constituting a virtual quadrangle having four intersection positions as vertices, or the inner angle (first inner corner) of the vertex at which each side intersects, and each diagonal line connecting the opposite vertices of the virtual quadrangle If at least one of the length and the inner angle (second inner angle) of the intersection where the diagonal intersects is not within the range of the respective reference values, the image is measured again and recalculated. The error can be reduced, and the coil terminal position can be determined with higher accuracy.

  For example, the position on the long side or the short side in the outer shape of the coil conducting wire part is not measured depending on how the light is hit, and the long side or the short side in the outer shape of the coil insulating part where the insulating coating is not peeled off. The upper position may be measured. At that time, it passes through a straight line passing through an erroneous measurement position on the long side or short side in the outer shape of the coil insulating part and a normal measurement position on the long side or short side in the outer shape of the coil conductor part. A deformed virtual quadrangle having four intersection positions where the straight line intersects is formed. The length of each side in the deformed virtual quadrilateral, the interior angle (first interior angle) of the intersecting vertices of each side, the length of each diagonal connecting the opposite vertices of the virtual quadrangle, and the interior angle of the intersection at which the diagonal intersects ( There is a high possibility that at least one of the second interior angles will be out of the range of each reference value. In that case, since the image is measured again and recalculated, it is possible to prevent erroneous verification. Therefore, the coil terminal position can be determined with higher accuracy.

  According to the present invention, in a stator having a plurality of U-shaped segment coils made of rectangular wires, the positional accuracy at the tip of the coil terminal can be kept within a predetermined standard value, and the joining strength of the coil terminal can be ensured. A method for manufacturing a stator can be provided.

In the stator manufacturing method according to the present embodiment, it is a perspective view showing a state in which a plurality of U-shaped segment coils made of rectangular wires are inserted into slots of the stator core. It is a perspective view showing the state which twisted and formed the coil terminal of the stator shown in FIG. 1 in the circumferential direction. It is a perspective view showing the U-shaped segment coil of the stator shown in FIG. It is a perspective view showing the coil terminal of the segment coil shown in FIG. It is a schematic perspective view of the test | inspection apparatus used for the test process which concerns on this embodiment. It is a top view showing the measurement location which measures the outline of the coil conductor part shown in FIG. It is a top view showing the virtual quadrangle | vertical which makes the vertex the intersection position of the straight line which passes each 2 points | pieces on the long side and short side in the measurement location shown in FIG. FIG. 8 is a plan view illustrating a diagonal line connecting the vertices of the virtual quadrangle illustrated in FIG. 7. It is a top view showing the case where two places among the measurement places shown in Drawing 6 measure the position on the long side in the outline of a level difference part. FIG. 10 is a plan view illustrating a virtual quadrangle when the position illustrated in FIG. 9 is measured. It is a top view showing the diagonal which connects the vertex of the virtual quadrangle shown in FIG. It is an inspection flow figure concerning this embodiment. It is a data scatter diagram showing the inspection result before twist forming in the manufacturing method of the stator concerning this embodiment. It is a data scatter diagram showing the inspection result after twist forming in the manufacturing method of the stator concerning this embodiment. FIG. 5 is a monitor diagram showing a two-dimensional image after twist forming in the stator manufacturing method according to the present embodiment.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. First, in the stator manufacturing method according to the present embodiment, the segment coil insertion and twist forming steps will be schematically described, and then the coil terminal position inspection step, which is a feature of the present embodiment, will be described in detail. Finally, the inspection result in the inspection process of this embodiment will be described.

<Manufacturing method of stator>
(Segment coil insertion and twisting process)
The manufacturing method of the stator 1 according to the present embodiment includes a step of inserting the segment coil Sg into the stator core 2 and a twist forming process, a coil terminal position inspection process, and a coil terminal Sga joining process. The joining process of the coil terminal Sga uses the Tig welding method, but since the Tig welding method is known, the description thereof is omitted here.
First, the process of inserting the segment coil into the stator core and the twisting process will be described. FIG. 1 is a perspective view showing a state in which a plurality of U-shaped segment coils made of rectangular wires are inserted into slots of a stator core in the stator manufacturing method according to the present embodiment. FIG. 2 is a perspective view showing a state in which the coil terminal of the stator shown in FIG. 1 is twisted in the circumferential direction. FIG. 3 is a perspective view showing the U-shaped segment coil of the stator shown in FIG. FIG. 4 is a perspective view showing a coil terminal of the segment coil shown in FIG.

As shown in FIG. 1, the stator 1 according to this embodiment includes a stator core 2 and a stator coil SC.
In the stator core 2, a plurality of slots 22 are formed in the circumferential direction at equal intervals in the radial direction from the inner peripheral surface 21 of the cylindrical stator core body 20. In the slot 22, a U-shaped segment coil Sg made of a rectangular wire is inserted in a plurality of layers laminated in the radial direction. The segment coil Sg has a coil terminal Sga projecting upward by a predetermined length from the upper end of the stator core body 20. The gap between the coil terminals Sga adjacent in the radial direction is expanded in advance in the radial direction in order to join the coil terminals having the same phase.
In the segment coil Sg, the coil connecting portion Sgc protrudes downward from the lower end of the stator core body 20 by a predetermined length. A mounting flange 23 and a bolt through hole 24 that are attached to a motor case (not shown) are formed on the outer peripheral portion of the stator core body 20.

As shown in FIG. 2, the coil terminal Sga is twisted in the circumferential direction in order to join in-phase coil terminals inserted in different slots 22. For example, in the case of the stator 2 of a three-phase, eight-pole motor, 48 slots 22 are formed in the circumferential direction, and an in-phase segment coil Sg is inserted every six slots. Therefore, when 10 segment coils Sg are stacked in one slot 22 in the radial direction, the coil terminals Sga of the five segment coils Sg arranged every other layer are twisted clockwise in the circumferential direction. The coil terminals Sga of the remaining five segment coils Sg are formed by twisting counterclockwise in the circumferential direction, and the coil terminals of the same phase separated by 6 slots are overlapped at the same position in the circumferential direction. . The coil terminal Sga formed by twisting in the circumferential direction is composed of a coil conductor portion Sga1 erected upward and a coil insulating portion Sga2 inclined in the circumferential direction clockwise or counterclockwise. The coil conductor portion Sga1 is a portion where the insulating coating is peeled off by cutting or the like so that the conductor portion is exposed from the tip portion to a predetermined position. The coil insulating portion Sga2 is a portion in which the conductor portion is covered with an insulating film in order to ensure insulation with adjacent coil terminals.
A three-phase power line Sgd is formed in an L shape on the outer peripheral side of the upper end of the stator core 2.

As shown in FIG. 3, the segment coil Sg is formed in a substantially U shape by edgewise bending one flat wire. A flat wire is a conducting wire having a rectangular cross section having a long side of about 3 to 10 mm and a short side of about 1 to 5 mm. The surface is covered with an insulating coating such as enamel. The thickness of the insulating coating is about 80 to 110 μm.
The segment coil Sg includes a linear coil terminal Sga, a coil body portion Sgb, and a mountain-shaped coil crossing portion Sgc. The coil terminal Sga includes coil conductor portions Sga1A and Sga1B from which the outer insulating coating D is peeled off, and coil insulating portions Sga2A and Sga2B whose outer periphery is covered with the insulating coating D. The coil body portion Sgb includes coil insulating portions SgbA and SgbB whose entire outer periphery is covered with an insulating coating D. The coil crossover portion Sgc is composed of coil inclined portions SgcA and SgcB inclined in both the left and right directions, and a central coil peak portion SgcC, and the entire outer periphery is covered with an insulating coating D.

As shown in FIG. 4, a stepped portion Sga21 is formed between the coil conductor portion Sga1 (Sga1A, Sga1B) and the coil insulating portion Sga2 (Sga2A, Sga2B). The length of the coil conductor portion Sga1 in the vertical direction is about 8 to 10 mm. The height t of the stepped portion Sga21 is about 80 to 90 μm.
The upper end of the coil conductor portion Sga1 forms a tip end portion Sga11 of the coil terminal Sga. The tip end portion Sga11 is a flat surface and has a chamfered outer periphery. The side surface of the coil conductor portion Sga1 includes a flat long side surface Sga12 and a flat short side surface Sga13, and chamfers are formed at four corners. In addition, the in-phase segment coil Sg joins the tip portions Sga11 of each other by Tig welding in a state where the long side surfaces Sga12 are in contact with each other or close to each other.

(Inspection device for coil terminal position)
Next, the inspection apparatus for the coil terminal position will be described. FIG. 5 shows a schematic perspective view of an inspection apparatus used in the inspection process according to the present embodiment.
As shown in FIG. 5, the inspection device 10 includes an image processing device 4 and a table driving device 5.
The image processing device 4 measures a radial position and a circumferential position at the distal end Sga11 of the coil terminal and a second axial position (vertical direction) at the distal end Sga11 of the coil terminal. The measurement part 42, the data processing part 43 which calculates the measurement data which the 1st measurement part 41 and the 2nd measurement part 42 measured, and the display part 44 which displays the result calculated by the data processing part 43 are provided. . The data processing unit 43 can give various instructions regarding image measurement such as measurement start, measurement end, and position movement to the first measurement unit 41 and the second measurement unit 42.

The 1st measurement part 41 arrange | positions imaging cameras, such as a CCD camera, toward a coil terminal below, and measures the external shape of coil conducting wire part Sga1 of a coil terminal from image data. The 1st measurement part 41 measures coil terminal Sga in the state where the position was fixed fundamentally. When one coil terminal Sga is measured, the work rotates to measure the next coil terminal Sga. When the coil terminal Sga of the entire circumference is measured, the first measuring unit 41 moves in the arrow T1 direction (radial direction) and measures the coil terminal Sga of the adjacent layer. At this time, the first measurement unit 41 moves in the arrow T2 direction (axial direction) and adjusts the focal length for each measurement target.
The 2nd measurement part 42 arrange | positions slit-shaped optical sensors, such as a laser sensor, toward a lower coil terminal, and measures the cross-sectional shape of coil conducting-wire part Sga1 of a coil terminal from slit-shaped reflected light. The second measuring unit 42 measures a plurality of coil terminals Sga that are moved and stacked in the direction of the arrow T3 (radial direction) at a time. The second measurement unit 42 moves in the arrow T4 direction (axial direction) and adjusts the focal length for each measurement target. The arrow T1 direction and the arrow T3 direction are directions orthogonal to each other.

  The table driving device 5 includes a table 51 on which the pallet 3 that supports the stator 1 with the segment coil Sg inserted into the stator core 2 is placed, and rotates the table 51 in the direction of the arrow R1 around the axis at the time of measurement. A drive unit 52 (not shown) that horizontally moves in the direction of arrow R2 when unloaded is provided. Since the position of the coil terminal Sga differs between the coil terminal Sga before and after the coil terminal Sga of the segment coil Sg is twisted, the table driving device 5 sets the measurement start position based on the master jig. Adjust.

(Image measurement of coil terminal position, data processing)
Next, a data processing method for measuring the image of the coil terminal Sga and obtaining the radial and circumferential positions of the coil terminal Sga from the image data will be described. FIG. 6 is a plan view showing a measurement location for measuring the outline of the coil conductor portion shown in FIG. FIG. 7 is a plan view showing a virtual quadrangle whose vertex is the intersection of straight lines passing through two points on the long side and the short side in the measurement location shown in FIG. FIG. 8 is a plan view showing a diagonal line connecting the vertices of the virtual rectangle shown in FIG. FIG. 9 is a plan view showing a case where two of the measurement points shown in FIG. 6 measure the position on the long side of the outline of the stepped portion. FIG. 10 is a plan view showing a virtual quadrangle when the position shown in FIG. 9 is measured. FIG. 11 is a plan view showing a diagonal line connecting the vertices of the virtual rectangle shown in FIG.

First, as shown in FIG. 6, image measurement is performed by selecting two ranges each of the long side and the short side in the outer shape of the coil conductor portion Sga1. This image measurement is performed by the first measurement unit 41.
The measurement range on the long side of the coil conducting wire portion Sga1 is the range of (a) and (b) above the drawing and the range of (e) and (f) below the drawing. Further, the measurement range on the short side in the coil conductor portion Sga1 is the range of c and d on the right side of the drawing and the range of k and k on the left side of the drawing. In each measurement range, the outline of the coil conductor portion Sga1 is acquired as image data from the difference in brightness between the coil conductor portion Sga1 and the step portion Sga21.
Next, the position of two points on the long side and the position of two points on the short side are calculated from the acquired image data. This calculation is performed by the data processing unit 43. Specifically, from the image data measured in the range of A to A, the center point on the outline of the coil conductor portion Sga1 in each measurement range, the positions a, b, e, f on the long side, and Calculation is performed as positions c, d, g, and h of two points on the short side.

  Next, as shown in FIG. 7, the positions a, b, e, and f of the two points on the long side intersect with the straight lines passing through the positions c, d, g, and h of the two points on the short side. Two intersection positions K, L, M, and N are calculated. Further, the lengths L1 and L2 of the sides constituting the virtual quadrangle having the four intersection positions K, L, M, and N as vertices, and the interior angle (first interior angle) θ1 of the vertex at which the sides intersect are calculated. . These calculations are performed by the data processing unit 43.

Next, as shown in FIG. 8, the position G at which the two diagonals passing through the paired vertexes at the four intersecting positions K, L, M, and N intersect is calculated as the center position of the tip Sga11 at each coil terminal Sga. To do. Also, the lengths L3 and L4 of the diagonal lines connecting the paired vertices of the virtual quadrangle, and the interior angle (second interior angle) θ2 of the intersection where the diagonal lines intersect are calculated. These calculations are performed by the data processing unit 43.
As described above, image measurement is performed on the coil terminal Sga, and the radial position and the circumferential position of the tip end Sga11 in the coil terminal Sga are determined from the image data as the position G of the intersection where the diagonal lines connecting the opposite vertices of the virtual rectangle intersect. Can be sought.

However, the coil insulation in which the insulation film is not peeled off by not including the position on the long side or the short side in the outer shape of the coil conducting wire portion Sga1 in the measurement range depending on the lighting method when measuring the image of the coil terminal Sga. The position on the long side or the short side in the outer shape of the part Sga2 may be the measurement range.
For example, as shown in FIG. 9, there are cases where the measurement ranges on the long side in the outer shape of the coil insulating portion Sga2 are measured. In that case, two positions of the four points on the long side are calculated as positions B and F on the outline of the coil insulating portion Sga2.
Further, as shown in FIG. 10, two straight lines passing through the two positions a and e on the outline B of the two points B and F and the coil conductor portion Sga1, and four points on the short side. The deformed virtual quadrangle having the four intersection positions Q, R, S, and P where the two straight lines passing through the positions c, d, g, and h intersect is formed.

In addition, as shown in FIG. 11, a position T where two diagonal lines passing through the opposite vertices at the four intersection positions Q, R, S, and P by the deformed virtual quadrangle intersect with each other is defined as a tip Sga11 at each coil terminal Sga. It is calculated as the center position of. However, as a matter of course, the position T is deviated from the position G which is the normal center position of the tip end portion Sga11 in the coil terminal Sga obtained by the method shown in FIGS. If the amount of deviation is outside the range of the predetermined reference value, the position accuracy of the coil terminal Sga cannot be guaranteed, and the joining strength when joined by welding or the like is lowered. In the present embodiment, an inspection flow to be described later is used in order to maintain the bonding strength of the coil terminal Sga at an appropriate value.
It should be noted that the lengths L5 and L6 of each side in FIG. 10 and the inner angle (first inner angle) θ3 of the vertices intersecting each side, and the length L7 of each diagonal line connecting the opposite vertices of the virtual quadrangle in FIG. The data processing unit 43 calculates the inner angle (second inner angle) θ4 of the intersection where L8 and the diagonal line intersect.

(Inspection flow of coil terminal position)
Next, an inspection flow of radial and circumferential positions in the coil terminal Sga will be described. FIG. 12 shows an inspection flowchart according to this embodiment.
As shown in FIG. 12, the inspection flow SS according to the present embodiment includes the lengths L1 and L2 of the sides of the virtual quadrangle, the lengths L3 and L4 of the diagonal lines, and the interior angles (first interior angles) at which the sides intersect. It is determined whether θ1 and the interior angle (second interior angle) θ2 of the intersection where the diagonal lines intersect each other are within the range of the reference value, and if not, steps S1 to S1 are performed so that remeasurement and recalculation are performed. S7 is configured. In the stator manufacturing method, this inspection flow is preferably performed both before the coil terminal Sga is twisted and after the coil terminal Sga is twisted.
Specifically, in step S1, if the length L1 of the long side of the virtual rectangle is out of the range of the reference values L11 to L12, the first measurement unit 41 performs remeasurement, and the data processing unit 43 performs the measurement. By calculating again from the image data, the length L1 of the long side is obtained. If the length L1 of the long side of the virtual rectangle is within the range of the reference values L11 to L12, the process proceeds to step 2.

In step 2, if the length L2 of the short side of the virtual rectangle is out of the range of the reference values L21 to L22, the first measurement unit 41 performs remeasurement, and the data processing unit 43 calculates again from the image data. Thus, the length L2 of the short side is obtained. If the length L2 of the short side of the virtual rectangle is within the range of the reference values L21 to L22, the process proceeds to step 3.
In step 3, if the length L3 of the diagonal line of the virtual rectangle is out of the range of the reference values L31 to L32, the first measurement unit 41 performs remeasurement, and the data processing unit 43 recalculates the image data. To obtain a diagonal length L3. If the length L3 of the diagonal of the virtual rectangle is within the range of the reference values L31 to L32, the process proceeds to step 4.

In step 4, if the length L4 of the diagonal of the virtual rectangle is out of the range of the reference values L41 to L42, the first measurement unit 41 performs remeasurement, and the data processing unit 43 recalculates the image data. To obtain a diagonal length L4. If the length L4 of the diagonal of the virtual rectangle is within the range of the reference values L41 to L42, the process proceeds to step 5.
In step 5, if the inner angle (first inner angle) θ1 of the vertex at which each side of the virtual quadrangle intersects is out of the range of the reference values θ11 to θ12, the first measuring unit 41 performs remeasurement, and the data processing unit 43 To calculate the inner angle (first inner angle) θ1 again from the image data. If the interior angle (first interior angle) θ1 of the virtual rectangle is within the range of the reference values θ11 to θ12, the process proceeds to step 6.

In step 6, if the interior angle (second interior angle) θ2 of the intersection where the diagonal lines of the virtual quadrangle intersect is outside the range of the reference values θ21 to θ22, the first measurement unit 41 performs the remeasurement, and the data processing unit 43 performs the measurement. Then, the inner angle (second inner angle) θ2 is obtained by calculating again from the image data. If the interior angle (second interior angle) θ2 of the virtual quadrangle is within the range of the reference values θ21 to θ22, the process proceeds to step 7.
Step 7 formally calculates the position of the intersection where the diagonal lines of the virtual rectangle intersect as the center position of the tip end portion Sga11 in the coil terminal Sga.

(Inspection result of coil terminal position)
Next, the inspection result of the coil terminal position in this inspection process will be described. FIG. 13 is a data scatter diagram showing the inspection results before twist forming in the stator manufacturing method according to the present embodiment. FIG. 14 is a data scatter diagram showing the inspection results after twist forming in the stator manufacturing method according to the present embodiment. FIG. 15 is a monitor diagram showing a two-dimensional image after twisting in the stator manufacturing method according to the present embodiment.

The data P1 shown in FIG. 13 is measured before the coil terminal Sga is twisted, and the above-described image measurement and data processing are performed a plurality of times. This is data calculated as the center position of Sga11. In this figure, the horizontal axis X indicates the radial position, and the vertical axis Y indicates the circumferential position. A virtual line Q1 indicates a range of reference values in the radial direction and the circumferential direction.
As shown in FIG. 13, the calculated data P1 has little variation and is all within the range of the reference value.

Data P2 shown in FIG. 14 is measured after the coil terminal Sga is twisted, and the above-described image measurement and data processing are performed a plurality of times, and the position of the intersection where the diagonal lines of the virtual quadrangle intersect is determined as the tip Sga11. This is data calculated as the center position. In this figure, the horizontal axis X indicates the radial position, and the vertical axis Y indicates the circumferential position. An imaginary line Q2 indicates a range of reference values in the radial direction and the circumferential direction.
As shown in FIG. 14, the calculated data P <b> 2 has little variation, but is all out of the standard value range. In this case, it was possible to modify the twist forming jig and the like so that they were all within the standard range.
As shown by the above inspection results, according to this inspection process, the position of the tip end portion Sga11 in the coil terminal Sga can be measured with very high accuracy, and the quality can be reliably determined.

  FIG. 15 shows a configuration in which after the coil terminal Sga is twisted using the second measuring unit 42, the slit light of the laser sensor is irradiated toward the coil terminal Sga, and the eight pieces stacked in the radial direction from the reflected light. The cross-sectional shape of the coil conductor portion Sga1 is measured. In this figure, the horizontal axis X indicates the radial position, and the vertical axis Z indicates the axial position. The imaginary line W indicates a window range for measuring the axial position of one coil conductor portion Sga1. In the window range, the maximum value of the vertical axis Z can be calculated as the axial position of the tip end portion Sga11 of the coil conductor portion Sga1.

<Effect>
According to the present embodiment, the inspection step calculates the center position of the tip end portion Sga11 in each coil terminal Sga from data obtained by image measurement of the outer shape of the coil conductor portion Sga1 from which the insulating coating D is peeled off in the coil terminal Sga. Since the quality of the position accuracy is determined, the position accuracy at the tip end Sga11 of the coil terminal Sga can be kept within a predetermined standard value, and the bonding strength of the coil terminal Sga can be ensured.
That is, by calculating the center position of the tip end portion Sga11 in each coil terminal Sga, whether or not the circumferential position and the radial position of the tip end portion Sga11 in each coil terminal Sga are within a predetermined reference value is welded. Since it can confirm before joining by etc., joining by welding etc. of coil terminal Sga can be performed appropriately, and required joining strength can be ensured.
Further, since the outer shape of the coil conductor portion Sga1 from which the insulating coating has been peeled is image-measured, the contours of the coil terminals do not overlap by separating at least the thickness of the stripped insulating coating D. Therefore, the error of the image data is small and the coil terminal position can be determined with high accuracy.

  Further, according to the present embodiment, the inspection process is provided both before and after the coil terminal Sga is twisted in the circumferential direction along the upper end portion of the stator core 2. It is possible to guarantee the positional accuracy of each coil terminal Sga before being twisted, and to reduce variations in the position of the tip end portion Sga11 of the coil terminal Sga after the twisting. Therefore, the joining strength of the coil terminal Sga can be more easily ensured.

In addition, according to the present embodiment, two points on the long side are selected from the long side and the short side in the outer shape of the coil conductor portion Sga1, and two ranges are selected for image measurement. And the position of two points on the short side are calculated. By selecting two image measurement ranges, the light disturbance factor is reduced, and each of the two points on the long side and the short side to be calculated is calculated. The error in the position can be reduced.
Also, four intersection positions where straight lines passing through the positions of the two points intersect are calculated, and a position where two diagonal lines passing through the intersection positions intersect is calculated as the center position of the tip end portion Sga11 in each coil terminal Sga. Therefore, a virtual quadrangle having four intersection positions as vertices is formed, and a position obtained by dividing the two diagonals of the virtual quadrant into two equals becomes the center position of the tip end portion Sga11 in each coil terminal Sga. Therefore, even if the virtual quadrangle forms a rectangle, a square, a rhombus, a parallelogram, etc., the center position of the tip Sga11 at each coil terminal Sga is the same position from the opposite vertex, and the coil terminal position is more The determination can be made with higher accuracy.

  Further, according to the present embodiment, the lengths L1 and L2 of the sides constituting the virtual quadrangle having the four intersection positions as vertices, or the internal angle (first internal angle) θ1 of the vertex at which the sides intersect, the virtual quadrangle When at least one of the lengths L3 and L4 of the diagonal lines connecting the opposite vertices and the inner angle (second inner angle) θ2 of the intersection of the diagonal lines is not within the range of the respective reference values, image measurement is performed again. Therefore, it is possible to reduce the error due to lighting and reduce the position of the coil terminal with higher accuracy.

  In particular, the present invention can be used as a stator manufacturing method including an inspection step of measuring and determining a coil terminal position by image measurement after assembling a plurality of segment coils to a stator core.

DESCRIPTION OF SYMBOLS 1 Stator 2 Stator core 3 Pallet 4 Image processing apparatus 5 Table drive apparatus 10 Inspection apparatus 20 Stator core main body 41 1st measurement part 42 2nd measurement part 43 Data processing part D Insulation coating SC Stator coil Sg Segment coil Sga Coil terminal Sga1 Coil conductor part Sga11 tip

Claims (4)

In a stator having a plurality of U-shaped segment coils made of rectangular wires, the position of each coil terminal is measured by image measurement after the U-shaped segment coils are assembled to the stator core and before the coil terminals of the same phase are joined together. A stator manufacturing method comprising an inspection process for determining whether the positional accuracy is good or bad,
The inspection step calculates the center position of the tip of each coil terminal from data obtained by image measurement of the outer shape of the coil conductor part from which the insulating coating has been peeled off at the coil terminal, and determines whether the position accuracy is good or bad. A manufacturing method of a stator characterized by the above. In the manufacturing method of the stator according to claim 1,
The method for manufacturing a stator, wherein the inspection step is provided before and after the coil terminal is twisted in the circumferential direction along the end of the stator core. In the manufacturing method of the stator according to claim 1 or 2,
Image measurement is performed by selecting a range for each of two locations on the long side and the short side of the outer shape of the coil conductor portion, and the position of two points on the long side and two points on the short side from the measured image data Calculating the position of
Calculating four intersecting positions where straight lines passing through the positions of the two points intersect,
A method for manufacturing a stator, characterized in that a position where two diagonal lines passing through the intersecting position intersect is calculated as a center position of a tip portion of each coil terminal. In the manufacturing method of the stator according to claim 3,
The length of each side constituting the virtual quadrangle having the four intersecting positions as vertices, or the inner angle (first inner angle) of the vertex at which each side intersects, the length of each diagonal line connecting the opposite vertices of the virtual quadrangle, A method of manufacturing a stator, characterized in that, when at least one of the internal angles (second internal angles) of the intersection where the diagonal lines intersect is not within the range of the respective reference values, the image is measured again and recalculated.