Segment coil peeling inspection method and peeling inspection device used therefor

Abstract

To determine the amount of peeling at a peeled portion which is an end of each segment coil to be joined to prevent poor joining due to poor peeling before joining the segment coils of a motor stator.SOLUTION: A segment coil peeling inspection device 100 includes: mounting means 110 for rotatably mounting a motor stator 50 in which a segment coil is housed; and an inspection unit 120 arranged at a distance from the mounting means. The inspection unit includes: a length measurement probe that can move in an axial direction of the motor stator; and a first conductivity probe and a second conductivity probe for detecting conductivity that are arranged at a distance from the length measurement probe and can move in the axial direction of the motor stator. The first conductivity probe can rotate around the end of the segment coil.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method and device for inspecting the peeling state of the insulating coating of segment coils in a motor stator that houses multiple segment coils within a stator core, and particularly to a segment coil peeling inspection method and peeling inspection device that are suitable for use in mass-produced motors. [Background technology]

[0002] In the manufacture of motors consisting of a stator and a rotor, multiple rows of segment coils are arranged radially within the stator core, and multiple segment coils are arranged circumferentially, with each segment coil connected to an adjacent segment coil at one end to form a single-phase, three-phase, or multi-phase electric motor. The segment coils are housed in slots provided on the inner surface of the stator core, or are fixed and arranged at approximately equal intervals circumferentially using other means.

[0003] After the segment coils are fixedly positioned within the stator core in a previous process, one end of the segment coil is connected to other segment coils by laser welding or the like to form a coil that makes up one phase of the stator. Before laser welding can be performed, the insulating coating that covers the entire segment coil must be stripped from the welding end of the segment coil, and in a previous process the insulating coating is stripped by laser processing (e.g., JP 2000-23428 A) or cutting work (e.g., JP 2012-257442 A) or the like.

[0004] However, if the length of the peeled portion, which is the end where the segment coil is welded, deviates from the specified dimension, there is a risk that the insulating coating will melt due to the welding heat during welding and become fused to the adjacent segment coil. This may also change the position of the segment coil inside the stator core, which may cause problems during subsequent motor assembly work. Furthermore, in some cases, there is a risk that adjacent segment coils may come into contact with each other, causing a short circuit and resulting in a failure to achieve the specified motor performance. Therefore, in the past, defective products were extracted by visually inspecting the state of peeling of the insulating coating at the welded ends of the segment coils, or by conducting a conductivity test after completing the manufacture of the stator.

[0005] Patent Document 1 discloses an apparatus for inspecting stators with high accuracy at a location distant from the stator core. This publication describes an insulation-coated conductor inspection method for inspecting the electrical insulation characteristics of an insulation-coated conductor in a coil formed by winding the insulation-coated conductor. The method involves placing the coil in a test vessel, reducing the pressure inside the vessel, providing a gap between the coil and the electrode, and then arranging electrodes facing each other. An AC voltage is then applied between the electrode and the coil. The frequency of discharges occurring between the coil and the electrode is measured, and if the frequency is equal to or greater than a reference frequency, the product is deemed to be non-defective.

[0006] Patent document 2 also describes that in order to improve the joint strength between segment coils of a rotating electrical device, the peeled portion at the end of a segment coil is joined to the peeled portion of another segment coil, and a buffer recess is provided on the joint surface facing the peeled portion of the other segment coil.

[0007] Furthermore, Patent Document 3 discloses a method for suppressing the occurrence of coating residue at the coating peeled portion of a unit coil, thereby suppressing the occurrence of welding defects and an increase in electrical resistance. Specifically, at least the insulating coating formed on a pair of opposing side surfaces is removed to form a pair of removed surfaces in a portion of a conductor wire with a rectangular cross section that forms multiple unit coils, and pressure is applied to one of the pair of removed surfaces to plastically deform the conductor portion, making the other of the removed surfaces a flat surface continuous with the surface of the insulating coating, thereby forming a pair of opposing surfaces in the coating peeled portion. Thereafter, the other pair of opposing side surfaces is removed to form the other opposing surface in the coating peeled portion in a portion of the conductor wire. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-8124 [Patent Document 2] Japanese Patent Application Publication No. 2019-118214 [Patent Document 3] Japanese Patent Application Publication No. 2019-221034 Summary of the Invention [Problem to be solved by the invention]

[0009] For example, in the case of a motor stator with 24 segment coils arranged circumferentially and in three radial layers, there are a total of 72 coil joints. Visually monitoring these joints imposes a significant amount of work on the inspector. Particularly in the case of mass-produced motors, motor stators are continuously transported to the inspection location, so as the inspection volume increases, it is also necessary to shorten the inspection time. Therefore, in the past, instead of visual inspection, continuity and insulation tests were performed after all segment coils were joined to identify defective products. With this inspection method, even if joint defects repeatedly occur in the same position due to a defect in the stripping device, it may be impossible to address the issue until a large number of defective products have been produced.

[0010] On the other hand, the method of inspecting an insulating coated body described in Patent Document 1 has the advantage of making it easy to detect insulation defects not only at the joints but throughout the coil. However, this method not only requires large-scale equipment, but also cannot detect peeling conditions specific to the joints, making it impossible to determine whether the insulating coating at the joints is peeling properly. Early detection of peeling defects at joints and feedback of the results to the upstream process to prevent poor positioning of segment coils due to improper laser welding would improve motor manufacturing throughput, but this point is not disclosed in Patent Document 1.

[0011] Patent Document 2 describes a method for reducing the stress intensity factor of a joint by removing the insulating coating from the joint of a segment coil, providing a buffer recess in the removed area, and laser welding the end. However, even this publication does not disclose how to optimize the amount of insulating coating removed to prevent poor positioning and short circuits in the segment coil caused by imperfect laser welding.

[0012] Furthermore, Patent Document 3 describes a method of cutting or removing the portions corresponding to the ends of a rectangular cross-section segment coil on both sides with a punch to remove the insulating coating and thin the coil, plastically deforming one side of the thinned portion to form a peeled portion, and then placing the two peeled portions back to back with each other, after which the end faces are laser welded. This publication does indeed state that the segment coils are placed back to back with no gaps between them, which suggests that there is no risk of springback occurring after laser welding and the welded portion peeling. However, even with this method, there is no disclosure of the peeling defects that can occur when cutting with a punch.

[0013] The present invention has been made in consideration of the above-mentioned drawbacks of the conventional technology, and its purpose is to determine the amount of peeling at the end of the segment coil of the motor stator before joining the segment coil, thereby preventing poor joining in the next process due to poor peeling. Another purpose of the present invention is to establish an inspection method suitable for mass production in accordance with the above-mentioned purpose. [Means for solving the problem]

[0014] A feature of the present invention that achieves the above-mentioned object is that in an inspection method for a motor stator in which segment coils are housed in a stator core, after the segment coils are wound around the stator core, it is detected before joining whether the peeling length of the peeling portion, which is the joint end portion between the segment coils, is within a predetermined length range.

[0015] In this feature, it is desirable to include the steps of first measuring the end position of each segment coil, detecting the conductivity state of the segment coil at a first position that is a first predetermined distance away from the end position of the segment coil, and detecting the conductivity state of the segment coil at a second position that is a second predetermined distance away from the end position of the segment coil.It is even more desirable to judge all the segment coils to be joined as good products and proceed with the next manufacturing process if conductivity is confirmed at the first position and insulation is confirmed at the second position, and to judge all other segment coils as defective products and either feed back to the previous process or stop manufacturing.

[0016] Another feature of the present invention that achieves the above-mentioned object is that in a segment coil peeling inspection device that includes a mounting means for rotatably mounting a motor stator containing a segment coil, and an inspection unit arranged at a distance from the mounting means, the inspection unit includes a length measuring probe that can move in the axial direction of the motor stator, and a first conductivity probe and a second conductivity probe for detecting conductivity that are arranged at a distance from the length measuring probe and can move in the axial direction of the motor stator.

[0017] In this feature, when detecting the conductivity of a segment coil, it is desirable to arrange the first conductivity probe and the second conductivity probe so that the first conductivity probe for detecting conductivity is capable of contacting the end, side portion, of the segment coil, and the second conductivity probe for detecting conductivity is capable of contacting the end face of the segment coil being inspected.

[0018] Furthermore, it is desirable that the length measuring probe is connected to a first actuator that drives the length measuring probe in the axial direction of the stator, and that the first and second conductivity probes are connected to a second actuator that drives the first and second conductivity probes in the axial direction of the stator and to a control means that controls the drive amount of the second actuator, and that the control means use the second actuator to drive and control the first conductivity probe from the end face of the segment coil to the first position and the second position axially inward, and that the control means also include a rotation means that allows the first conductivity probe to rotate around the end of the segment coil. Furthermore, it is particularly desirable that the first position is a peeling detection position for the segment coil and the second position is an insulation detection position for the segment coil. [Effects of the Invention]

[0019] According to the present invention, before joining the segment coils that make up the motor stator, it is determined whether the peeled length of the peeled portion, which is the joint end of the segment coil, is a predetermined length, thereby preventing joint defects due to poor peeling.In addition, since an automated detection means is provided instead of manual inspection such as visual inspection, an inspection method suitable for mass production can be established. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic oblique view of the main parts of one embodiment of a segment coil peeling inspection device according to the present invention. [Figure 2] 2A and 2B are diagrams showing an inspection unit provided in the peel inspection device shown in FIG. 1, where (a) is a front view and (b) is a side view. [Figure 3] 2A and 2B are perspective views for explaining the operation of the peel inspection device shown in FIG. 1, in which FIG. 2A shows a measurement state using a length measuring probe, and FIG. 2B shows an inspection state using a conduction probe. [Figure 4]4 is a partially enlarged view of FIG. 3, where (a) shows the measurement state using a length measuring probe, (b) shows the inspection state using a conduction probe, and (c) is a partial top view of the segment coil. [Figure 5] 1A to 1C are diagrams showing an embodiment of a rotating part of a conductivity probe according to the present invention, in which (a) is a perspective view, (b) is a front view, and (c) is a side view. [Figure 6] 1 is a flowchart illustrating one embodiment of a segment coil peeling inspection method according to the present invention. [Figure 7] 10 is a flowchart illustrating another embodiment of a segment coil peeling inspection method according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] An embodiment of a segment coil peeling inspection method and a peeling inspection device used therein according to the present invention will be described below with reference to the drawings. Figure 1 is a perspective view of the main parts of a segment coil peeling inspection device 100 according to the present invention. This peeling inspection device 100 is used in line processing or batch processing and is suitable for mass-produced products.

[0022] In a general-purpose motor, to construct a motor stator 50, segment coils 54 are wound in slots formed in a stator core 52, and the ends of the wound segment coils 54 are joined by laser welding or the like to form a single coil. In order to perform the laser welding, part of the insulating coating originally formed on the segment coils 54 is peeled off to form peeled portion 62 (see Figure 4).

[0023] The segment coil peeling inspection device 100 inspects whether the welds of the segment coils 54 built into the stator core 52 are properly formed before welding. The peeling inspection device 100 broadly comprises a mounting means 110 and an inspection unit 120. The mounting means 110 mounts the motor stator 50 to be inspected and assists the inspection unit 120 in positioning the segment coil to be inspected. Meanwhile, the inspection unit 120 is equipped with measuring tools and inspection instruments that inspect the peeling conditions of the peeled portions 62 formed at each end of the numerous segment coils 54 that the motor stator 50 has.

[0024] The motor stator 50, which has the segment coil 54 to be joined, is transported by a robot or the like (not shown) and then fitted onto the stator fitting shaft (simulated rotor) 222 formed on the vertical axis. The mounting means 110 is equipped with a workpiece circumferential positioning cylinder 230. A positioning block 232 attached to the tip of the cylinder 230 is inserted into the circumferential reference position 50a of the motor stator 50, ensuring the absolute position of the segment coil 54 being inspected.

[0025] A toothed pulley 218 is attached to the lower end of the stator fitting shaft 222, and is connected via a toothed belt 216 to a toothed pulley 214 attached to the shaft end of a stepping motor 212 that rotates the stator fitting shaft 222. The stepping motor 212 is used to rotate the motor stator 50 around the stator fitting shaft 222 by a fixed angle at a time.

[0026] The inspection unit 120 includes a length measuring probe 380, which is a characteristic feature of the present invention, and multiple conductive probes 412 and 414. To position these two types of probes 380, 412, and 414, the inspection unit 120 includes linear motion mechanisms in two orthogonal axes, namely, a horizontal (Y-axis) linear motion mechanism 310 and a vertical (Z-axis) linear motion mechanism 330. The first Z-axis linear motion mechanism 330 is attached to the Y-axis linear motion mechanism 310 via a mounting device 320. The inspection unit 120 includes an inspection unit control means 450 that drives and controls these linear motion mechanisms 310 and 330. Furthermore, the inspection unit 120 includes a control device 460, such as a personal computer, that includes a memory means 462 that stores the measurement and inspection results of the length measuring probe 380 and the conductive probes 412 and 414. Together with the inspection unit control means 450, this constitutes a control means 400.

[0027] The inspection unit 120 will be described in detail using FIG. 2. Note that the inspection unit control means 450 is not shown in FIG. 2. FIG. 2(a) is a front view of the inspection unit 120, and FIG. 2(b) is a side view of the inspection unit 120. The Y-axis linear motion mechanism 310 of the inspection unit 120 has a rail-shaped guide 314 and a slider 312. A servo motor (not shown) rotates a ball screw (not shown), causing the slider 312 to move left and right in FIG. 2(a) along the guide rail 314 as a guide. Similarly, the first Z-axis linear motion mechanism 330 has a rail-shaped guide 332 and a slider 334. A servo motor (not shown) rotates a ball screw (not shown), causing the slider 334 to move up and down in FIG. 2(a) or 2(b) along the guide rail 332 as a guide. Because general-purpose products can be used for Y-axis linear motion mechanism 310 and first Z-axis linear motion mechanism 330, in order to connect them, an attachment device 320 is disposed on the back surface of first Z-axis linear motion mechanism 330. By providing attachment device 320, first Z-axis linear motion mechanism 330 can move together with slider 312 of Y-axis linear motion mechanism 310 in the Y direction, i.e., left and right directions in Figure 2(a).

[0028] A base plate (mounting plate) 356 extending over almost the entire width of the first Z-axis linear motion mechanism 330 is fixed to the upper surface of the first Z-axis linear motion mechanism 330. A guide rail 352 extending over almost the entire length of the base plate 356 in the vertical direction is vertically disposed on the upper surface of the base plate 356, on the right side in FIG. 2(a), and a slider 354 engages with the guide rail 352. The guide rail 352 and the slider 354 constitute the second Z-axis linear motion mechanism 350.

[0029] A base plate (measurement probe mounting plate) 372 having an L-shaped shape in a side view is attached to the upper surface of the slider 354. The base plate (measurement probe mounting plate) 372 mounts a movable end of a cylinder 370, which is an actuator. A cylinder holder 360 is attached to a middle portion in the vertical direction (Z direction), which is the longitudinal direction of the base plate 356, in order to fix the fixed end of the cylinder 370, which is the starting point of the movable part, to the base plate 356. The cylinder 370 is inserted into a hole (not shown) formed in the cylinder holder 360 to form a fixed insertion part, and with the fixed insertion part as the fixed end, the cylinder 370 expands and contracts up and down (Z direction) together with the vertical movement of the slider 354 of the second Z-axis linear motion mechanism 350, i.e., the base plate 372.

[0030] The movable end of the cylinder 370 is fixed, and an axial middle portion of the length measuring probe 380 is fixed to a base plate 372 constituting the second Z-axis linear motion mechanism 350 at an interval in the width direction (Y direction) of the base plate 356. Therefore, the length measuring probe 380 moves up and down (Z direction) with the up and down movement of the base plate 372 of the second Z-axis linear motion mechanism 350, i.e., with the extension and contraction of the cylinder 370. In other words, the length measuring probe 380 can be positioned in the up and down direction by controlling the extension and contraction of the cylinder 370. A stopper mounting plate 357 is attached to the lower end surface of the base plate 356, and a stopper 358 is attached to the stopper mounting plate 357. The stopper 358 prevents the base plate 372 of the second Z-axis linear motion mechanism 350 from running out of control and provides a reference position.

[0031] A conductive probe holder 410 having an L-shape in a side view is attached to the lower end of a base plate 356 constituting the first Z-axis linear motion mechanism 330, at a position spaced apart in the width direction from the guide rail 352, i.e., on the left side in FIG. 2(a). A rotating disk 420 having through holes formed in two locations, one at the center and one away from the center, is attached to the horizontal surface of the conductive probe holder 410. First and second conductive probes 412, 414 are inserted through the through holes formed in the rotating disk 420. The rotating disk 420 is rotated by a driving device (not shown) in response to commands from a control device 460.

[0032] The operation of the inspection unit 120 when inspecting the continuity of the peeled portion of the segment coil 54 using the inspection unit 120 configured in this manner will be explained using Figures 3 and 4. Figure 3(a) is a perspective view showing the state in which the end face position of the segment coil 54 to be joined is measured using the length measuring probe 380 possessed by the inspection unit 120 prior to the continuity inspection, and Figure 3(b) is a perspective view showing the state in which the continuity of the segment coil 54 to be joined is inspected using the first and second continuity probes 412, 414. Figure 4(a) is a partially enlarged view of Figure 3(a), and Figure 4(b) is a partially enlarged view of Figure 3(b). Figure 4(c) is a top view of part A in Figure 4(b).

[0033] The multiple segment coils 54 whose ends were peeled off in the previous process are stored in the stator core 52, with the peeled ends 70 facing up, in rows of 24 in the circumferential direction and three layers in the radial direction. The motor stator 50 with the segment coils 54 stored therein is then placed in this state on the mounting means 110. The inspection unit 120 controls the Y-axis linear motion mechanism 310 and the circumferential positioning cylinder 230 and stepping motor 212 (see Figure 1) of the mounting means 110 to position the segment coil 54 to be inspected first at the inspection position.

[0034] As shown in FIG. 4(c), the joined segment coils 54, 54 (pairs) are arranged so that their radial back surfaces abut, with a gap 66 between each pair of segment coils 54 and the adjacent pair of segment coils 54. The axial (Z-direction) heights of each pair of segment coils 54 are consistent, but the axial (Z-direction) heights of the other pairs of segment coils 54 do not necessarily match due to assembly accuracy. Therefore, to check whether the length of the peeled portion 62 of each segment coil 54 is the correct length, the height of the upper end surface 58 of each segment coil 54 is measured in advance (Step 1), and then it is checked whether the peeled portion 62 is formed within a predetermined distance from the measured height position (Step 2). In this example, the reference height of the peeled portion 62 from the end surface is 10 mm, with a tolerance of less than 1 mm. In other words, since the length of the peeled portion 62 needs to be in the range of 10 to 11 mm, it is confirmed that there is continuity at a position 10 mm above the edge 58 of the peeled portion 62, and that there is no continuity (is in an insulating state) at a position 11 mm above the edge 58 of the peeled portion 62.

[0035] To perform step 1, as shown in FIG. 3(a), the inspection unit control means 450 is used to position the first Z-axis linear motion mechanism 330, which is the actuator of the first and second conductivity probes 412 and 414, at an upper position. This prevents the first and second conductivity probes 412 and 414, which are attached to the base plate 356 of the first Z-axis linear motion mechanism 330 via the conductivity probe holder 410, from contacting the motor stator 50. At the start of step 1, the base plate 372 of the second Z-axis linear motion mechanism 350 is raised to the position where the cylinder 370 is most retracted, in order to prevent the length measuring probe 380 from colliding with or contacting the motor stator.

[0036] In this state, the length measuring probe 380 is positioned above the pair of segment coils 54 to be inspected using the Y-axis linear motion mechanism 310 or the like. Then, the inspection unit control means 450 controls the extension of the cylinder 370, causing the abutment portion 381 formed at the lower end of the cylinder 370 to abut against the upper end surface 58 of the segment coil 54 (see FIGS. 4(a) and 4(b)). The output (height) of the length measuring probe 380 when it abuts against the segment coil 54 is stored in the memory means 462 (see FIG. 1).

[0037] Next, to execute step 2, the cylinder 370 is retracted to its shortest length, the base plate 372 of the second Z-axis linear motion mechanism 350 is positioned at the upper position, and the length measuring probe 380 is retracted from the motor stator 50. At the same time, the Y-axis linear motion mechanism 310 and other components are controlled to position the second end-face conductivity probe 414 above the segment coil 54 to be inspected. Next, based on the position of the end face 58 of the segment coil 54 measured by the length measuring probe 380 and stored in the memory means 462, the inspection unit control means 450 drives the first Z-axis linear motion mechanism 330 to abut the contact portion 424 of the second conductivity probe 414 against the end face 58 of the segment coil 54. The first side-face conductivity probe 412 is preset to abut the contact portion 422 of the first side-face conductivity probe 412 against the side face of the same segment coil 54 that the contact portion 424 of the second conductivity probe 414 abuts against, at a position 10 mm from the end face. When the contact portions 422, 424 of the first and second conductivity probes 412, 414 come into contact with the segment coil, a continuity test is performed using the first and second conductivity probes 412, 414 as electrodes (see FIG. 3(b)). After the continuity test at the height of 10 mm is completed, the first Z-axis linear motion mechanism 330 is moved downward by another 1 mm. At this time, the second conductivity probe 414 moves upward by 1 mm relative to the conductivity probe holder 410 against the spring 484 (see FIG. 5(b)) that is pressing the second conductivity probe 414 downward. Through the above operation, the first conductivity probe 412 is positioned 11 mm from the end face 58, and the second conductivity probe 414 is positioned at the end face, so a continuity test is performed using the first and second conductivity probes 412, 414 as electrodes. The results of the continuity test are stored in the memory means 462.

[0038] Because the segment coil 54 in this embodiment has a rectangular cross section, inspection of the length of the peeled portion 62 is performed on three of the four sides 60a, 60b, and 60c that form the side surfaces of the segment coil 54. The remaining side cannot be inspected because it faces back to back with the paired segment coil 54 and forms the joint 56, but inspection is not necessary because it does not affect the conductivity of the other pairs of segment coils 54. Step 2 is performed sequentially on the three sides 60a, 60b, and 60c of the peeled portion, and once inspection of one side 60a is completed, the first and second conductivity probes 412 and 414 are temporarily separated from the segment coil 54, and the inspection unit control means 450 drives and controls the rotating disk 420, which is the rotation means, to move the position of the first conductivity probe 412 from side 60a to side 60b. Then, the contact portions 422, 424 of the first and second conductivity probes 412, 414 are brought into contact with predetermined positions on the segment coil 54 to perform a conductivity test. After the conductivity test on the side surface 60b is completed, the first conductivity probe 412 is moved to the side surface 60c.

[0039] Once the continuity test is completed for each of the three sides of a pair of segment coils 54 (six sides in total, with the position of the end face continuity probe 414 changed for every three sides), a continuity test is performed on the other adjacent pair of segment coils 54. If the next pair of adjacent segment coils 54 to be tested is adjacent in the radial direction of the motor stator 50, the Y-axis linear motion mechanism 310 is controlled and driven, and the test is performed from step 1, which is height measurement using the length measuring probe 380. If the next pair of adjacent segment coils 54 to be tested is adjacent in the circumferential direction of the motor stator 50, the stepping motor 212 of the mounting means 110 is driven to rotate the motor stator 50 in the circumferential direction by the pitch of one segment coil.

[0040] Next, details of another embodiment of a rotating unit that rotates the conduction probes 412, 414 to test the continuity on three sides of the segment coil 54 will be described with reference to Figure 5. In the above embodiment, the rotating means 420 was rotated by a drive unit (not shown), but in this embodiment, a rotation control device 464 rotates the conduction probe 412 via a pair of rotating disks 470, 472. Figure 5(a) is a perspective view of the rotating unit of the conduction probes 412, 414, Figure 5(b) is a front view thereof, and Figure 5(c) is a side view thereof.

[0041] A conductive probe holder 410 having an L-shape in a side view is attached to the base plate 356 in order to hold the conductive probes 412, 414. A rotation control device 464 that rotates and drives the conductive probes 412, 414 is attached to the underside of the conductive probe holder 410. The rotation control device 464 is equipped with a drive motor (not shown), and an upper rotating disk 470 is attached to the shaft of the drive motor. Here, the upper rotating disk 470 is configured to be movable in the X-axis direction (a direction perpendicular to both the up and down direction and the movement direction of the Y-axis linear motion mechanism 310) together with the drive motor. A lower rotating disk 472 is disposed at a vertical interval from the upper rotating disk 470. The upper rotating disk 470 and the lower rotating disk 472 are connected by a plurality of support posts 474 (three in the figure). Therefore, when the upper rotating disk 470 rotates, the lower rotating disk 472 also rotates in synchronization.

[0042] A through hole is formed in the center of the lower rotating disk 472, and an end face conductive probe 414 is fitted into this hole. A spring 484 is disposed in contact with the upper end of the conductive probe 414, and the conductive probe 414, together with the portion extending upward from the upper rotating disk 470, is held within a cap 482. Meanwhile, the side face conductive probe 412 is fitted into a hole formed eccentrically and obliquely in the lower rotating disk 472. When the side face conductive probe 412 and the end face conductive probe 414 are fitted into the holes formed in the lower rotating disk 472 into which they fit, respectively, in a free state where the conductive probes 412 and 414 are not contacting anything, the difference in vertical height between the tips of the conductive probe 412 and the conductive probe 414, or more specifically, their contact portions 422 and 424, is set to the peel limit height. In this example, the adhesive attachment position of the cap 482 is adjusted so that it is 10 mm.

[0043] Therefore, both the conductive probes 412 and 414 are moved to the height position measured by the length measuring probe. The first Z-axis linear motion mechanism 330 is used to lower the cap 482, and when the end face continuity probe 414 contacts the end face of the segment coil 54, the spring 484 maintains its initial state. After the inspection of the peeled portion 62 is completed, the first Z-axis linear motion mechanism 330 is further lowered to inspect the non-peeled portion or insulated portion 64. The continuity probe 412 is lowered to the insulated portion 64 along with the lower rotating disk 472, but the spring 484 in the cap 482 contracts, leaving the end face continuity probe 414 in contact with the end face of the segment coil 54. In other words, the end face continuity probe 414 rises relative to the lower rotating disk 472. During the continuity inspection, the rotation control device 464 or control device 460 applies current between the lead wire 478 connected to the cap 482 or end face continuity probe 414 and the lead wire 476 connected to the side face continuity probe 412, thereby inspecting the continuity state. The test results are stored in the storage means 462 (see FIG. 1).

[0044] The details of the peel inspection method for the segment coil 54 using the peel inspection device 100 configured as described above will be described with reference to the flowcharts shown in Figures 6 and 7. Figure 6 is a flowchart showing one embodiment of the peel inspection method according to the present invention, and Figure 7 is a flowchart showing a peel inspection method according to another embodiment.

[0045] First, the reference points (zero points) of the probes 380, 412, and 414 are aligned. This is because the length measuring probe 380 and the continuity probes 412 and 414 can move independently. The zero point alignment is performed using a standard such as a gauge block or by mounting a reference stator model on the mounting table 220 (step S502). As an example of the zero point alignment, a block with a known step is prepared, and the contact portion 381 of the length measuring probe 380 is brought into contact with the higher part of the step, and the contact portion 422 of the first continuity probe 412 is brought into contact with the lower part of the step. At this time, the second Z-axis linear motion mechanism 350 is brought into contact with the stopper 358. The position of the length measuring probe 380 at this time is defined as the zero point.

[0046] After completing the zero-point positioning of each probe 380, 412, 414, the motor stator 50 to be inspected, which has been transported to the inspection unit 120 in a batch or assembly line fashion, is placed on the mounting table 220 of the mounting means 110 using a transport robot (not shown) or the like (step S504). Then, using the stepping motor 212, the Y-axis linear motion mechanism 310, or the like, the length measuring probe 380 is positioned so that it is located directly above the segment coil 54 to be measured (step S510). At this time, in the first Z-axis linear motion mechanism 330, the inspection unit control means 450 drives and controls the ball screw so that the base plate 356 attached to the slider 334 is positioned at an upper position (near the upper limit within the movement range). This completes the preparation stage for peel inspection (FIG. 6(a)).

[0047] Next, the actual peeling inspection process shown in FIG. 6(b) begins. When the inspection starts, in step S512, the cylinder 370 extends, bringing the length measuring probe 380 into contact with the segment coil. As the cylinder 370 extends, the slider 354 attached to the base plate 372 to which the tip of the cylinder 370 is fixed moves downward along the guide rail 352 in the second Z-axis linear motion mechanism 350, until the bottom surface of the base plate 372 abuts against the stopper 358 and stops. Since the length measuring probe 380 is also fixedly attached to the base plate 372, the length measuring probe 380 also moves downward as the cylinder 370 extends. When the base plate 372 abuts against the stopper 358, the length measuring probe 380, which had been in contact with the segment coil 54 just before abutting against the base plate 372, retracts, and the change in its position is stored in the storage means 462 as a change from the reference height (zero point). This determines the measurement reference position of the segment coil 54 that is currently being measured or inspected.

[0048] Now that the height of the end face 58 of the segment coil 54 to be inspected has been determined, the length measuring probe 380 is raised so that it does not interfere with the stator 50, etc. during the peel inspection. Specifically, the cylinder 370 is retracted, and the base plate 372 together with the slider 354 of the second Z-axis linear motion mechanism 350 is retracted upward from the motor stator 50 (step S514).

[0049] Next, using the stepping motor 212 and the Y-axis linear motion mechanism 310, the second conductivity probe 414 is positioned directly above the end face 58 of the segment coil to be inspected. The positioned second conductivity probe 414 is lowered to the measurement reference position measured by the length measuring probe 380, and the abutment portion 381 of the length measuring probe 380 is brought into contact with the end face 58 of the segment coil 54 (step S516). Note that in the following processing, the lowering and raising of the first and second conductivity probes 412, 414 is achieved by the servo motor rotating the ball screw provided in the first Z-axis linear motion mechanism 330. The positioning accuracy of the first Z-axis linear motion mechanism 330 is several μm, which is sufficient for determining the peel position. The inspection unit control means 450, which controls the second Z-axis linear motion mechanism 350, reads the height of the end face 58 of the segment coil 54 measured by the length measuring probe 380 from the memory means 462, and determines the amount of rotation of the ball screw, i.e., the amount of movement of the slider 334, based on the measurement value.

[0050] At the same time, the first conductivity probe 412 is lowered to a first continuity test height, for example, 10 mm from the end face 58. The first conductivity probe 412 is then brought into contact with one side face 60a of the segment coil (step S520). Note that if the difference in height between the contact portion 422 of the first conductivity probe 412 and the contact portion 424 of the second conductivity probe 414 is set to the first continuity test height in advance, this process is executed simultaneously with S516.

[0051] When the two continuity probes 412, 414 come into contact with the segment coil 54, current is passed through the lead wires 476, 478 to check for continuity (step S522). At the first continuity test height, if the stripping process of the segment coil 54 is normal, a stripped portion 62 is formed, so continuity is the normal state. If continuity is present, proceed to step S526. If there is no continuity, this indicates that the stripping process was insufficient. Therefore, as a defective product (NG), the circumferential position of the segment coil 54 currently being inspected relative to the reference position 50a of the motor stator 50 (see FIG. 1) is stored in the storage means 462 together with NG information (step S524), and proceed to step S526.

[0052] Next, in step S526, the first continuity probe 412 is further lowered on the same side of the segment coil 54 until it contacts the segment coil 54 at a second continuity test height, e.g., 11 mm above the end face 58. At this time, the second continuity probe 414 is displaced 1 mm upward relative to the continuity probe holder 410 or the rotating disk 420 (470, 472) against the spring 484 shown in FIG. 5(b). This achieves a second continuity test state. The peeling process is then inspected for pass / fail (step S528), as in step S522. However, unlike step S522, this time, continuity between the two continuity probes 412, 414 indicates that the peeled portion 62 is too long and therefore defective. At this second continuity test height, non-continuity indicates that the insulating portion 64 is maintained, and the product is non-defective. Therefore, if there is no continuity, the process proceeds to step S532, but if there is continuity, the product is deemed defective and the position of the defective segment coil 54 and NG information are stored in the storage means 462 in the same manner as in step S524 (step S530).

[0053] This completes the inspection of one side surface 60a of the segment coil 54, so the inspection position is changed to the other side surface 60b of the same segment coil 54. Even if the rotating means 420 is rotated in this state, rotation is prevented by the corners of the segment coil 54, so after the first conductivity probe is raised, the rotating means 420 (472) to which the conductivity probes 412, 414 are attached is rotated so that the first conductivity probe 412 can abut against the other side surface (step S532).

[0054] As described above, three sides of one segment coil 54 are inspected, so the same process is repeated three times (step S534). When the inspection of the same segment coil 54 is completed in step S534 and there are no other sides to inspect, the second conductivity probe 414 is raised (step S536), and the process proceeds to step S538 to move on to inspecting other segment coils 54.

[0055] In step S538, when inspection of all segment coils 54 to be inspected in the same motor stator 50 has been completed, the process proceeds to step S550 to complete the peel inspection (FIG. 6(c)). In step S538, if there are still segment coils 54 to be inspected, the process proceeds to step S540. In step S540, it is determined whether the segment coils 54 to be inspected next are in the same row within the motor stator 50. Here, the same row refers to a row aligned from the inner diameter side to the outer diameter side at the same position circumferentially of the motor stator. The motor stator illustrated in this embodiment includes 24 segment coils 54 (rows) in the circumferential direction and three layers in the radial direction, so each row includes three pairs of segment coils 54 (six segment coils 54 themselves) (see FIG. 4(c)).

[0056] If the movement of the conductive probes 412, 414 is within the same row, the inspection unit control means 450 drives and controls the stepping motor provided in the Y-axis linear motion mechanism 310 to move the conductive probes 412, 414 from the inner diameter side to the outer diameter side, or vice versa, by the distance of one pair of segment coils 54 (step S542). In step S540, if the movement of the conductive probes 412, 414 is not within the same row but to an adjacent row, the stepping motor 212 of the mounting means 110 is driven and controlled to rotate the motor stator 50 circumferentially by the distance of one segment (step S544). The above process is then continued until inspection of all segment coils 54 within the same motor stator 50 is completed.

[0057] After the peeling inspection process is completed (step S550), the process proceeds to the post-processing shown in FIG. 6(c). This post-processing checks whether or not there are any defective (NG) motor stators 50 in the peeling inspection. The controller 460 checks whether any defective (NG) information is stored in the storage means 462 (step S552). If even one defective (NG) has been detected, an alarm is generated in step S554 to notify the operator. The operator hears the alarm, checks the peeling status at the corresponding location, and if the peeling defect is specific to the peeling machine, repairs or improves the peeling machine. If the peeling defect is a one-off occurrence due to some factor, the peeled portion will likely be corrected manually. In other words, by providing this post-processing, it is possible to prevent the same peeling machine from repeatedly producing defects at an early stage.

[0058] Another embodiment of the method for inspecting segment coils 54 for stripping is shown in Figure 7. In Figure 7, the processes with the same step numbers as those in Figure 6 are the same as those in Figure 6, so their explanation will be omitted. This embodiment differs from the embodiment shown in Figure 6 in that when a defect (NG) is detected during stripping inspection, the inspection is immediately stopped. This is to allow for early extraction of defective products, even if it means stopping automated operations, in order to avoid being forced to inspect a large number of defective products, even if the frequency of defective products is extremely low.

[0059] Specifically, if a defect is detected in the process of step S522, which is an inspection in the conductive position, or step S528, which is an inspection in the non-conductive or insulated position, the automatic inspection is immediately stopped (step S610) and an alarm is sounded to notify the worker (step S612). Upon hearing the alarm, the worker either removes the motor stator 50 in which the defect was detected from the inspection unit 120 and places a new motor stator 50 in the inspection unit, or stops further inspection. This prevents the continued occurrence of defective products and minimizes the inspection work required for defective products. This method is suitable for rewinding segment coils from scratch around the stator core of a defective motor stator 50.

[0060] As described above, according to each embodiment of the present invention, it is possible to automatically and reliably determine whether the stripping portion at the joint of the segment coil is proper, thereby improving work efficiency and reliability. Furthermore, visual monitoring by the worker is no longer necessary, significantly reducing the burden on the worker. Furthermore, if a defect occurs due to the same stripping device, the cause of the stripping failure can be fed back to the stripping device early on, improving the yield rate of motor stator manufacturing or reducing the amount of work related to defective products. [Explanation of symbols]

[0061] 50... (motor) stator, 50a... reference position, 52... stator core, 54... segment coil, 56... joint portion, 58... (upper) end face, 60, 60a, 60b, 60c... measurement side, 62... peeled portion, 64... insulating portion (non-peeled portion), 66... ​​gap (space), 70... (segment coil) end, 100... peeling inspection device, 110... placement means, 120... inspection unit, 212... stepping motor 214...(toothed) pulley, 216...toothed belt, 218...(toothed) pulley, 220...mounting table, 222...stator fitting shaft (simulated rotor), 230...cylinder, 232...positioning block, 310...Y-axis linear motion mechanism, 312...slider, 314...guide rail, 320...mounting device, 330...first Z-axis linear motion mechanism, 332...guide rail, 334...slider, 35 0...second Z-axis linear motion mechanism, 352...guide rail, 354...slider, 356...base plate (mounting plate), 357...(stopper) mounting plate, 358...stopper, 360...cylinder holder, 370...cylinder (actuator), 372...base plate (length measuring probe mounting plate), 380...length measuring probe, 381...contact portion, 400...control means, 410...(conductive) probe holder, 412 ...(First) conductive probe (for side surface), 414...(Second) conductive probe (for end surface), 420...rotating means (rotating disk), 422, 424...contact portion, 450...inspection unit control means, 460...control device, 462...storage means, 464...rotation control device, 470...(upper) rotating disk, 472...(lower) rotating disk, 474...support, 476, 478...lead wire, 482...cap, 484...spring

Claims

1. A segment coil peeling inspection method for detecting the peeling length of a peeled portion, which is a joint end of a segment coil wound around a stator core of a motor stator, comprising: A step of contacting a length measuring probe with the segment coil to measure the position of an end face of the segment coil; A method for inspecting stripping of a segment coil, comprising the steps of determining the amount of movement of a conductive probe based on the position of the end face and contacting the conductive probe with the segment coil.

2. The conductive probe includes two conductive probes, The step of contacting the conductive probe with the segment coil includes: A method for inspecting a segment coil for peeling as described in claim 1, comprising abutting one of the conductive probes against the end face and abutting the other of the conductive probes against a side face of the segment coil.

3. A segment coil peeling inspection device that detects the peeling length of a peeled portion that is a joint end of a segment coil wound around a stator core of a motor stator, A length measuring probe for contacting the segment coil to measure the position of the end face of the segment coil; A conduction probe that is brought into contact with the segment coil to measure a conduction state, A segment coil peeling inspection device, wherein the amount of movement of the conductive probe is determined based on the position of the end face measured by the length measuring probe.

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