Coil welding device and welding method

Abstract

The control unit (5) functions as an end information acquisition means that acquires various kinds of end information for each of the ends of the welding target, which are the sites, from the obtained end images of the coil. That is, the control unit (5) can acquire the end information from the images of the ends of the pair of segment coils to be welded. The control unit (5) functions as a welding condition setting means for setting welding conditions on the basis of the obtained end information. The control unit (5) controls the operation or the like of the laser irradiation unit (11) on the basis of the set welding conditions for each end section, and integrates the pair of segment coils to be welded by irradiating laser light onto the end sections of the pair of segment coils to be welded.

Description

Technical Field

[0001] The present invention relates to a welding device and a welding method for a coil used in, for example, a segmented coil motor. Background Art

[0002] For example, as winding wires used in stators of vehicle-mounted motors, enameled wires with round cross-sections have been used in the past. However, in recent years, rectangular winding wires with rectangular cross-sections have been used to improve the space factor. In addition, in the past, a manufacturing method of winding the winding wires around the core of the stator was mostly adopted, but with the adoption of rectangular winding wires, a method of forming the winding wires into short segmented coils and welding the ends of the segmented coils to each other after assembling them on the stator has tended to be adopted.

[0003] Fig.11 1 is a partial perspective view showing the stator core 50. The stator core 50 is substantially cylindrical and is formed by laminating electromagnetic steel sheets, for example. A plurality of slots 53 are provided on the inner circumference of the stator core 50. In each slot 53, a conductor is arranged and the conductors are joined to each other to form a coil.

[0004] Fig.12 1 is a schematic diagram showing a state where segment coils 55a and 55b are arranged in slots 53. It should be noted that for simplicity, only a pair of segment coils 55a and 55b are shown in the figure for description. The segment coils 55a and 55b have a substantially rectangular cross section and include a conductor portion and an insulating layer (not shown) covering the conductor portion.

[0005] Segment coils 55a and 55b are bent into a substantially U-shape and are arranged so that both ends protrude from one side of stator core 50. At this time, segment coils 55a and 55b protruding from stator core 50 are bent in a predetermined direction and arranged so that the ends are close to each other, forming a joint portion 59 where the ends are joined to each other.

[0006] Typically, the ends of the segment coils 55a and 55b are welded to each other by laser welding. For example, a method has been proposed in which the ends of the segment coils 55a and 55b are arranged in contact with each other, and a laser is irradiated from the end surface side of the segment coils 55a and 55b in a manner passing through a predetermined trajectory, thereby welding the two (Patent Document 1).

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: WO2019 / 159737 Summary of the invention

[0010] Problems to be solved by the invention

[0011] In Patent Document 1, the shapes of the segment coils to be joined are input, and laser beams are irradiated onto the end faces of the segment coils in a trajectory corresponding to their dimensions, thereby welding the ends together. However, the ends of the segment coils must be completely brought into contact with each other in advance, which results in poor workability.

[0012] For example, Fig.13A As shown in FIG. 1 , when the end portions of segment coils 55a and 55b are separated, it is difficult to join them along the irradiation trajectory as in Patent Document 1. On the other hand, the inventors have found that as a laser welding method for segment coils 55a and 55b separated in this way, the end surfaces of segment coils 55a and 55b are alternately scanned along a predetermined trajectory and this operation is repeated, thereby enabling the two to be efficiently joined.

[0013] For example, in Fig.13A In the case of , first, the laser is scanned on the end face of the segment coil 55a according to the trajectory S, and then the laser is scanned on the end face of the segment coil 55b according to the trajectory T. Next, the laser is scanned on the end face of the segment coil 55a again according to the trajectory S, and this operation is repeated thereafter, whereby the end portions of the segment coils 55a and 55b can be melted in substantially the same manner and integrated.

[0014] However, it is difficult to arrange the segment coils 55a and 55b with high accuracy so that the positions of the ends of the segment coils 55a and 55b are always constant. Fig. 13B As shown in FIG. 1 , when the segment coil 55 b is arranged to be offset from the reference relative to the segment coil 55 a , a part of the track S deviates from the segment coil 55 b , and the segment coil 55 b cannot be properly melted.

[0015] Likewise, if Fig. 13C As shown in FIG. 1 , when the segment coil 55b is arranged to be offset in the vertical direction from the opposing position with the segment coil 55a, a part of the track S is separated from the segment coil 55b, and the segment coil 55b cannot be melted properly. In addition, although not shown in the figure, the end faces of the segment coils 55a and 55b only need to be located at the same height (on the same plane), but if the position is offset in one direction (for example, the depth direction of the paper), the focus of the laser on the segment coils 55a and 55b is offset, and the segment coils 55b on both sides cannot be melted properly.

[0016] However, as described above, the workability of accurately aligning and contacting the ends of the segment coils is poor, and it is difficult to completely eliminate the variation in the arrangement of the ends.

[0017] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a coil welding device and a coil welding method capable of welding coil ends of a segment coil or the like to each other with high accuracy.

[0018] Solutions to Solve Problems

[0019] In order to achieve the above-mentioned purpose, the first invention is a coil welding device, characterized in that the coil welding device comprises: an end information acquisition mechanism, which acquires end information from an image of the ends of a pair of the coils that are to be welded for a plurality of coils; a welding condition setting mechanism, which sets welding conditions based on the obtained end information; and a welding mechanism, which irradiates a laser to the ends of the pair of the coils that are to be welded for integration based on the set welding conditions.

[0020] Preferably, the coil welding device includes a storage device storing a plurality of the welding conditions, and the welding condition setting device reads out the welding condition associated with each of the end information from the storage device and sets the welding condition.

[0021] Preferably, the end information includes position information in three directions orthogonal to each other for the ends of the pair of coils.

[0022] The end information may include size information of the ends of a pair of the coils.

[0023] Alternatively, the end information includes shape information of the end face of the coil, and when the welding condition setting mechanism determines that the shape of the end face of the coil has a corner, the irradiation position of the laser is set to a position offset outward for each of the opposing end faces of the coil.

[0024] The coil welding device may further include a quality inspection mechanism for determining the quality of the welded portion based on an image of the welded portion welded by the welding mechanism.

[0025] Alternatively, the coil welding device may further include a quality monitoring mechanism that measures heat radiation light or reflected light from near the laser irradiation portion during welding by the welding mechanism, and monitors whether the heat radiation light or reflected light during laser irradiation is within a specified range.

[0026] In this case, when the quality monitoring means determines that the heat radiation light or the reflected light is not within a predetermined range, the welding conditions may be adjusted during welding by the welding means.

[0027] Alternatively, the coil welding device may further include a conveying mechanism, which conveys the workpiece to the welding mechanism after acquiring the end information in the end information acquiring mechanism. The coil welding device may simultaneously perform welding of the workpiece at the welding mechanism and acquisition of the end information of the next workpiece in the end information acquiring mechanism.

[0028] According to the first invention, first, each end information is obtained from the image of each end of a pair of coils to be welded, and the welding conditions of each joint are set based on the obtained end information, so that even if the end position is slightly offset, welding can be performed under appropriate conditions accordingly. Therefore, it is not necessary to accurately arrange the position of the coil end in advance.

[0029] Furthermore, when setting welding conditions based on each end information, by storing a plurality of welding conditions in advance in the storage means and reading out appropriate conditions, the ends of a pair of coils can be welded to each other more reliably under appropriate conditions even when displacements in multiple directions overlap.

[0030] Furthermore, by including position information in three directions orthogonal to each other for the ends of a pair of coils as the end information, appropriate welding conditions can be set for all the positional deviation directions.

[0031] In addition, by including the size information of the end of the coil as the end information, it is possible to reduce the input of the size of the coil in advance, etc. In addition, appropriate welding conditions can be set according to the size.

[0032] In addition, when it is determined that the shape of the end face of the coil has a corner, the laser scanning position is set to a position offset to the outside for the ends of each opposing coil, thereby suppressing the occurrence of so-called corner residues in which corner shapes remain outside the end faces of each other after welding.

[0033] Furthermore, by performing a quality inspection to determine the quality of the welded portion based on an image of the welded end portion, it is possible to determine whether the automatically set welding conditions are appropriate.

[0034] Furthermore, by measuring the heat radiation light or reflected light from the vicinity of the laser irradiation portion during welding and monitoring whether they are within a predetermined range, it is possible to understand during welding whether welding is being properly performed.

[0035] Furthermore, welding can be performed more stably by adjusting welding conditions during welding when it is determined by the quality monitoring mechanism that the heat radiation light or the reflected light is not within a predetermined range.

[0036] Furthermore, by separating the location where the end information is acquired from the location where welding is performed and carrying the workpiece to perform the operations of each unit, welding of the workpiece at the welding mechanism and acquisition of the end information of the next workpiece can be performed simultaneously.

[0037] The second invention is a coil welding method, characterized in that the coil welding method comprises: a process of obtaining each end information from an image of the ends of a pair of coils that are welding objects for a plurality of coils; a process of setting welding conditions based on the obtained end information; and a process of irradiating the ends of a pair of coils that are welding objects with laser light to integrate them based on the set welding conditions.

[0038] According to the second invention, by appropriately setting welding conditions according to the positional deviation of both end portions and the like, welding can be performed with high accuracy without strictly arranging the arrangement of the end portions before welding.

[0039] Effects of the Invention

[0040] According to the present invention, it is possible to provide a coil welding device and a coil welding method capable of welding the ends of the coils to each other with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 1 is a diagram showing the structure of the segment coil welding device 1 .

[0042] Figure 2 1 is a flowchart showing the steps of the segment coil welding method.

[0043] Figure 3 This is a conceptual diagram of the vicinity of the ends of the segment coils 17a and 17b.

[0044] Figure 4A 1 and 2 are diagrams showing scanning loci in a state where the segment coils 17 a and 17 b are offset in the Y direction.

[0045] Figure 4B 1 and 2 are diagrams showing scanning loci in a state where the segment coils 17 a and 17 b are offset in the X direction.

[0046] Figure 5A This is a diagram showing an irradiation method in a state where the segment coils 17 a and 17 b are offset in the Z direction.

[0047] Figure 5B This is a diagram showing an irradiation method in a state where the segment coils 17 a and 17 b are offset in the Z direction.

[0048] Fig. 6A 1 and 2 are diagrams showing scanning loci when the segment coils 17 a and 17 b do not have corners.

[0049] Figure 6B 1 and 2 are diagrams showing scanning loci when the segment coils 17 a and 17 b have corners.

[0050] Fig. 7A FIG. 1 is a diagram showing a scanning trajectory after the segment coils 17 a and 17 b are connected.

[0051] Figure 7B 1 is a diagram showing a scanning trajectory based on the sizes of the segment coils 17 a and 17 b .

[0052] Figure 8 1 is a flowchart showing the steps of the segment coil welding method.

[0053] Fig. 9A It is a conceptual diagram showing a quality control image after welding of segment coils 17a and 17b, and is a conceptual diagram showing an appropriate welding state.

[0054] Fig. 9B This is a conceptual diagram showing a quality control image after welding of segment coils 17 a and 17 b , and is a conceptual diagram for a case where the difference in the amount of melting is equal to or greater than a predetermined value.

[0055] Fig. 9C 1 is a conceptual diagram showing a quality control image after welding of segment coils 17 a and 17 b , and is a conceptual diagram showing a state in which adjacent welded portions are short-circuited.

[0056] Fig.9D It is a conceptual diagram showing a quality control image after welding of segment coils 17 a and 17 b , and is a conceptual diagram showing a state in which shrinkage of the welded portion is greater than a predetermined value.

[0057] Fig.10 1 is a flowchart showing the steps of the segment coil welding method.

[0058] Fig.11 It is a partial perspective view showing the stator core 50 .

[0059] Fig.12 1 and 2 are diagrams showing a state where segment coils 55a and 55b are connected.

[0060] Fig.13A 1 is a conceptual diagram showing a scanning trajectory of a laser beam based on the positions of the segment coils 55 a and 55 b .

[0061] Fig. 13B 1 is a conceptual diagram showing a scanning trajectory of a laser beam based on the positions of the segment coils 55 a and 55 b .

[0062] Fig. 13C 1 is a conceptual diagram showing a scanning trajectory of a laser beam based on the positions of the segment coils 55 a and 55 b . DETAILED DESCRIPTION

[0063] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figure 1 1 is a diagram showing the structure of a segment coil welding device 1. The segment coil welding device 1 is mainly composed of a control unit 5, a storage unit 7, an imaging unit 9, a laser irradiation unit 11, a detection unit 13, etc. As described above, the segment coil welding device 1 is a device for welding the ends of a plurality of segment coils arranged on a stator core.

[0064] The imaging unit 9 can capture a digital image of the ends of a pair of segment coils to be welded. It should be noted that, although there are multiple welding target parts for one workpiece, the imaging unit 9 does not necessarily need to obtain images for each of all welding target parts, and can also obtain images including multiple welding target parts at once.

[0065] The imaging unit 9 is connected to the control unit 5. The control unit 5 is a unit that performs control and calculation of the operations of each unit, and is composed of a computer or the like together with the storage unit 7 described later. The end image data captured by the imaging unit 9 is sent to the control unit 5. In addition, the control unit 5 can obtain end information from the image of the end of a pair of segment coils that are welding objects. That is, the control unit 5 functions as an end information acquisition unit that acquires various end information for each of the ends that are welding objects of each part from the obtained end image. In addition, the control unit 5 can associate the end information with the position information of each part that is the object of the end information and store it in the storage unit 7. It should be noted that the details of the end information will be described later.

[0066] The laser irradiation unit 11 is a welding mechanism that can irradiate laser light to the welding object part to perform welding. The laser irradiation unit 11 is controlled by the control unit 5, and can irradiate laser light to the ends of a pair of segment coils that are welding objects based on the welding conditions set by the control unit 5 to integrate them. It should be noted that the laser irradiation unit 11 can continuously irradiate while scanning the irradiation unit relative to a predetermined direction using, for example, an electric scanner. In addition, the focus depth, intensity, etc. of the laser irradiated from the laser irradiation unit 11 can also be controlled by the control unit 5.

[0067] The detection unit 13 can detect the heat radiation light or reflected light generated when the laser is irradiated to the welding object through the laser irradiation unit 11. The obtained information is sent in real time by the control unit 5. The control unit 5 can determine whether the heat radiation light or reflected light is appropriate (normal) as needed.

[0068] The transport device 3 is, for example, a transport mechanism that moves the workpiece from the operating range of the imaging unit 9 to the operating range of the laser irradiation unit 11. That is, in this embodiment, after the end information of each part is obtained in the imaging unit 9, the workpiece can be transported to the irradiation range of the laser irradiation unit 11. Therefore, the welding of the workpiece 15a by the welding mechanism and the acquisition of the end information of the next workpiece 15b by the end information acquisition mechanism can be performed simultaneously. It should be noted that the transport device 3 can also be any form such as a rotary table type, a belt conveyor type, etc.

[0069] The storage unit 7 can store various information. For example, a plurality of welding conditions are stored, and the control unit 5 can read out appropriate welding conditions associated with the respective end information from the storage unit 7 (storage means) for the respective end information of the aforementioned parts and set them. That is, the control unit 5 functions as a welding condition setting means for setting welding conditions based on the obtained end information. It should be noted that the welding conditions to be set include, for example, a part or all of the number of irradiations, irradiation position (scanning position), focal depth, output, etc. In addition, the control unit 5 can pre-store images obtained by the imaging unit 9, end information obtained from the images, and quality information obtained by the aforementioned detection unit 13.

[0070] It should be noted that the structure of the segment coil welding device 1 is not limited to the example shown in the figure, and other structures may be appropriately added, or a part of the structure may be omitted. For example, the conveying device 3 may not be used, and the acquisition of the image by the imaging unit 9 and the welding by the laser irradiation unit 11 may be performed in two steps at the same position. In addition, the detection unit 13 may not be used, and the quality may be managed by other methods. In addition, the control of each part may be controlled by different control units, but in the present invention, these control units are collectively defined as a single control unit 5.

[0071] Next, an example of a segment coil welding method using the segment coil welding device 1 will be described. Figure 2 This is a flowchart showing an example of the operation of the segment coil welding device 1 .

[0072] First, the end image of the segment coil is captured by the imaging unit 9 (step 101). As described above, each segment coil is arranged in the stator core and arranged inside the welding device. It should be noted that since there are multiple ends of a pair of segment coils to be welded (hereinafter referred to as "end pairs"), it is also possible to acquire images including multiple predetermined ranges in such a manner that multiple end pairs are included in one image.

[0073] Figure 3This is a conceptual diagram of the vicinity of the end portions of the segment coils 17a and 17b (end pair). Here, the opposing direction of the segment coils 17a and 17b is defined as the X direction, the axial direction of the segment coils 17a and 17b is defined as the Z direction, and the direction perpendicular to the above directions (the lateral offset direction of the segment coils 17a and 17b) is defined as the Y direction. In the imaging unit 9, the imaging direction and the like are set so that the positions in three mutually orthogonal directions can be grasped in this way. For example, images can be acquired from multiple directions for one end pair, or when acquiring an image from the Z direction, the position in the Z direction can be grasped by acquiring the focal depth information of the end surface.

[0074] Next, the control unit 5 acquires end information for each end pair to be welded (step 102 ). Specifically, for a plurality of segment coils (end pairs) arranged in the stator core, each end information is acquired from an image of the ends of a pair of segment coils to be welded.

[0075] As described above, as the end information, it is desirable to include position information in three mutually orthogonal directions for the ends (end pairs) of a pair of segment coils. For example, a reference position of each end pair is set relative to a reference point of the stator core. The reference position information of each end pair is stored in, for example, the storage unit 7. At this time, the control unit 5 obtains the offset from the reference position in the three directions for each end pair.

[0076] exist Figure 3 In the example shown, the position (position in the XYZ direction) of the end surface 19 of the segment coil 17 a obtained from the actual image is calculated with respect to the reference position A (position in the XYZ direction) of the segment coil 17 a. Similarly, the position (position in the XYZ direction) of the end surface 19 of the segment coil 17 b obtained from the actual image is calculated with respect to the reference position B (position in the XYZ direction) of the segment coil 17 b.

[0077] Next, the control unit 5 determines whether the amount of deviation from the reference position is greater than or equal to a predetermined value for each of the end pairs. For example, when the amount of deviation is greater than or equal to a predetermined value, it is determined that it is impossible to perform appropriate welding by irradiation with laser light (step 103). When it is determined that there is an end pair that cannot be welded, the operation is terminated without moving to the subsequent welding. It should be noted that the portion that cannot be welded may also be removed and the next welding process may be entered. In either case, for example, the display unit may be made to display which portion of the end pair has an abnormality.

[0078] Next, the control unit 5 sets welding conditions for each end pair based on the end information (step 104). For example, the control unit 5 reads out welding conditions associated with each end information from the storage unit 7 based on the obtained end information of the end pair and sets the conditions. In addition, the control unit 5 controls the operation of the laser irradiation unit 11 based on the set welding conditions for each end pair, irradiates the ends of a pair of segment coils to be welded with laser light, and integrates them by welding (step 105).

[0079] Figure 4A , Figure 4B 1 is a diagram showing an example of setting welding conditions (scanning position, etc.) based on the state of the end pair. It should be noted that in the following example, for simplicity, the figure shows an example in which only the segment coil 17b is offset from the reference. In the following example, the laser is alternately irradiated to the scanning position C and the scanning position D. In addition, at this time, the irradiation position (scanning position) can also be changed according to the number of irradiations.

[0080] Figure 4A 1 and 2 are diagrams showing a state where segment coil 17b is offset in the Y direction from reference position B. In this case, control unit 5 adjusts scanning positions C and D of laser beams irradiated onto end surfaces 19 of segment coils 17a and 17b as welding conditions in accordance with the offset.

[0081] in addition, Figure 4B 1 is a diagram showing a state where segment coil 17b is offset in the X direction from reference position B. In this case, control unit 5 similarly adjusts scanning positions C and D of laser beams irradiated onto end surfaces 19 of segment coils 17a and 17b in accordance with the offset.

[0082] in addition, Figure 5A , Figure 5B 1 is a diagram showing a case where the positions of the end faces 19 of the segment coils 17a and 17b are offset in the Z direction. Figure 5A As shown in FIG. 1 , when the offset in the Z direction is less than a predetermined value, the focus can be set on the end face 19 of the higher end face position (segment coil 17a), and the laser beam can be irradiated to the segment coil 17b at the focus depth. In this case, the segment coil 17a with the focus can be melted preferentially to increase the melting amount, thereby absorbing the offset in the height positions of the two.

[0083] On the other hand, Figure 5BAs shown in FIG. 1 , when the offset in the Z direction is greater than a predetermined value, the focus may be placed on the end face 19 of the segment coil 17a having a higher end face position and the end face 19 of the segment coil 17b having a lower end face position, respectively, and the number of laser irradiations to the segment coil 17a having a higher end face position may be increased. In this case, the amount of melting of the segment coil 17a having a larger number of laser irradiations may be increased, thereby absorbing the offset in the height positions of the two.

[0084] It should be noted that, in the above description, a case where the offset is generated in each direction is shown, but appropriate conditions are set for the offsets in the three directions. For example, welding conditions are prepared in advance for each combination of offset amounts in each direction and stored in the storage unit 7, and the control unit 5 can read out the welding conditions associated with each combination of the offset amount ranges in the three directions for each end pair, thereby performing welding.

[0085] It should be noted that the end information of the pair of segment coils 17a and 17b may include not only the position information of the end but also the shape information of the end surface 19 of the segment coils 17a and 17b. For example, Fig. 6A The figure shows a state where there is no corner (chamfering is performed) on the end faces 19 of the segment coils 17a and 17b. In this case, the control unit 5 reads the end face shape, and when it is determined that there is no corner (chamfering is performed on the corner), it irradiates the laser to each end face 19 under normal conditions and scans.

[0086] In contrast, Figure 6B As shown in FIG. 1 , when the control unit 5 determines that the shape of the end faces of the segment coils 17a and 17b has a corner, the irradiation / scanning position of the laser is set at a position shifted outward (on the side opposite to the direction of opposition in the X direction) with respect to the end faces 19 of the opposing segment coils 17a and 17b. In this way, it is possible to suppress the corners from remaining after welding. It should be noted that, as described above, shifting the scanning positions outwards in this way may be part of the irradiation of the predetermined number of times.

[0087] In addition, if Fig. 7A As shown, the welded end portion (welded portion 23) may be irradiated with laser light and scanned near the outer periphery (arrow E in the figure). This can also prevent corners from remaining in the outer shape of the welded portion 23 after welding.

[0088] In addition, the end information of the pair of segment coils 17a and 17b may also include size information. Figure 7B As shown, appropriate scanning positions C and D can also be set according to the sizes of the segment coils 17a and 17b.

[0089] The control unit 5 ends the welding operation when welding of all the end pairs to be welded is completed.

[0090] It should be noted that the segment coil welding device 1 can also monitor the quality of welding. Figure 8 1 is a flowchart showing an example of a process for quality management. As described above, during welding by the laser irradiation unit 11, the detection unit 13 ( Figure 1 ) can measure the heat radiation light or reflected light from the vicinity of the portion irradiated by the laser (near the end surface of the segment coil). The control unit 5 obtains the intensity of the heat radiation light or reflected light during the laser irradiation, and monitors in real time whether the heat radiation light or reflected light is within a predetermined range (step 106). That is, the detection unit 13 and the control unit 5 function as a quality monitoring mechanism during welding.

[0091] For example, when welding is performed properly, the thermal radiation light or reflected light is relatively stable, but when abnormal points (such as pores, pits, unevenness) occur, the thermal radiation light or reflected light changes greatly. Therefore, by monitoring this change, it is possible to monitor in real time whether the welding is being performed stably.

[0092] It should be noted that, when the control unit 5 determines that there is an abnormality during welding (step 107), the abnormal portion is stored in the storage unit 7 (step 108). By identifying the abnormal portion, more detailed quality confirmation can be performed later.

[0093] When welding of all the objects to be joined is completed, the control unit 5 obtains an image of the welded portion of the segment coil (step 109). Figure 1 In the example shown, the workpiece can be transferred from the welding area to the imaging area by the transport device 3 , and the image of each welding part 23 can be captured by the imaging unit 9 .

[0094] Fig. 9A is a conceptual diagram showing an example of an acquired image. For example, in the illustrated example, an image of the welded portion 23 is acquired from a direction substantially orthogonal to the opposing direction of the segment coils 17a and 17b, that is, from an obliquely upward direction. It should be noted that, as described above, a plurality of welded portions 23 may be included in one image.

[0095] The control unit 5 determines whether or not there is an abnormality in the weld 23 based on the image captured by the imaging unit 9 (step 110 ). That is, the control unit 5 functions as a quality inspection unit that determines the quality after welding based on the image of the weld 23 welded by the laser irradiation unit 11 .

[0096] For example, in Fig. 9A The image shown is the reference case. Fig. 9BAs shown, when it is determined that the difference in the melting amount of the segment coils 17a and 17b is larger than the reference range (the melting amount of one is smaller than the reference range) (portion F in the figure), the portion is determined to be abnormal.

[0097] In addition, if Fig. 9C As shown in FIG. 1 , when the welded portions 23 of the adjacent end pairs are in contact with each other (portion G in the figure), it is determined to be abnormal. Fig.9D As shown, when the weld 23 is viewed from above, if the necking is larger than the predetermined reference range (H in the figure), it is judged to be abnormal. In addition, for example, the gloss of the weld 23 is judged, and if the gloss is above the predetermined reference, it is judged to be of good quality. If the gloss is less, it is considered that the degree of oxidation is large and it is judged to be abnormal.

[0098] It should be noted that, when the control unit 5 performs the quality confirmation based on the image, it is also possible to perform the quality evaluation with a stricter quality standard (or quality item) than usual when the abnormal part is confirmed by the quality evaluation based on the thermal radiation light or the reflected light during welding (step 108). That is, when there is an abnormality in the quality confirmation during welding, the degree of the abnormality can be confirmed in more detail in the quality evaluation based on the image.

[0099] In addition, for the abnormality found by the image-based quality check, the control unit 5 determines whether the abnormal part can be normalized by re-welding (step 111). Fig. 9B In the case of, the melting amount can be balanced by further melting the segment coil 17a side. Fig.9D In the case of , it is possible to obtain an appropriate shape by further melting the portion with a larger necking.

[0100] In this way, if the abnormal part can be re-welded, the control unit 5 sets appropriate welding conditions for the part again and re-welds the part (step 113). It should be noted that the re-welding conditions of the abnormal part are pre-set according to the type, degree, position, etc. of the abnormal part, and the control unit 5 can set the welding conditions by reading the welding conditions that meet the conditions from the storage unit 7. In addition, when re-welding is performed, the control unit 5 drives the conveying device 3 to convey the workpiece to the welding area, so that welding based on the laser irradiation unit 11 can be performed.

[0101] If the abnormality cannot be corrected by re-welding or the abnormality cannot be corrected by re-welding, the control unit 5 issues a quality warning and terminates the operation (step 112). If there is a quality warning, the workpiece is determined to be defective.

[0102] It should be noted that, in the segment coil welding device 1 , the quality of welding can be monitored and fed back to the welding conditions in real time. Fig.10 FIG. 1 is a flow chart showing an example of a welding process. Fig.10 In the example shown, when it is determined by the quality monitoring mechanism that the heat radiation light or the reflected light is not within a predetermined range, the welding conditions can be adjusted during welding by the welding mechanism.

[0103] It should be noted that in Fig.10 In step 101 to step 105, Figure 2 In addition, step 106 to step 107 are the same as Figure 8 Therefore, the repeated description of the steps from step 101 to step 107 will be omitted.

[0104] exist Fig.10 In the example shown, during welding, when the intensity of the heat radiation light or the reflected light is obtained by the detection unit 13 and the control unit 5 determines that there is an abnormality in welding, the control unit 5 temporarily adjusts the welding conditions according to the abnormality (step 114). For example, when the intensity of the heat radiation light or the reflected light is below a predetermined value, the output of the laser is increased, and when the intensity of the heat radiation light or the reflected light is above a predetermined value, the output of the laser is reduced. Such fine adjustment of the welding conditions is performed in real time until the welding of the welded portion is completed (step 115).

[0105] Thus, by controlling the intensity of the heat radiation light or the reflected light to be constant within a predetermined range, the surface state of the weld is stabilized, thereby stabilizing the welding range. In addition, the unstable region from the start of irradiation until melting progresses sufficiently can be reduced.

[0106] As described above, according to the present embodiment, it is possible to obtain an image of the end of the segment coil before welding, and set appropriate welding conditions for each pair of end portions to be welded based on the image, thereby reducing welding defects and enabling welding with stable quality. In addition, it is not necessary to make the segment coils contact each other before welding, and a slight arrangement deviation can be tolerated.

[0107] In addition, by storing appropriate conditions corresponding to the state of the end pair in advance as welding conditions in the storage unit 7, welding can be performed under stable conditions. It should be noted that the welding conditions may not be stored in advance in the storage unit 7, and the laser irradiation position and the like may be calculated based on the obtained end information. In other words, the welding conditions may be set by correcting the laser irradiation position each time for the position deviation relative to the reference without making a program in advance.

[0108] Furthermore, by using position information of the end portions in three orthogonal directions as the end portion information for setting welding conditions, it is possible to set appropriate welding conditions in response to positional deviations in any direction.

[0109] Furthermore, by including size information of the end of the segment coil as the end information for setting welding conditions, welding can be performed under appropriate conditions according to the size of end surface 19 of the segment coil.

[0110] Furthermore, by including the shape information of the segment coil as the end information for setting the welding conditions, welding can be performed under appropriate conditions depending on, for example, the presence or absence of chamfering.

[0111] In addition, by determining the quality of the welded portion based on the image after welding, it is possible to accurately detect abnormalities in the welded portion. In this case, it is also possible to determine whether welding can be performed again based on the type of abnormality.

[0112] In addition, by measuring the heat radiation light or reflected light from the vicinity of the laser irradiation part during welding, the presence or absence of abnormality can be detected in real time during welding. At this time, by adjusting the welding conditions in real time based on the measurement results of the heat radiation light or reflected light, stable welding can be performed.

[0113] Furthermore, by providing a conveying device 3 for conveying the workpiece between the location where the image is acquired and the location where welding is performed, it is possible to acquire the image of the next workpiece simultaneously during welding. Therefore, welding work can be performed efficiently.

[0114] The embodiments of the present invention are described above with reference to the accompanying drawings, but the technical scope of the present invention is not limited by the aforementioned embodiments. Obviously, those skilled in the art can think of various variations or modifications within the scope of the technical ideas recorded in the technical solution, and can understand that these variations and modifications certainly also belong to the technical scope of the present invention.

[0115] Description of Reference Numerals

[0116] 1………Segmented coil welding device

[0117] 3…………Transportation device

[0118] 5………Control Department

[0119] 7………Storage

[0120] 9…………Photography Department

[0121] 11……Laser irradiation part

[0122] 13…………Detection Department

[0123] 15a, 15b…………Workpiece

[0124] 17a, 17b... Segmented coil

[0125] 19…………End face

[0126] 21……Laser

[0127] 23…………Welding section

[0128] 50………Stator core

[0129] 53………slot

[0130] 55a, 55b... Segmented coil

[0131] 59…………Joint part.

Claims

1. A coil welding device, characterized in that: The coil welding device comprises: an end information acquisition unit for acquiring end information from an image of ends of a pair of the coils to be welded, with respect to the plurality of coils; a welding condition setting mechanism that sets welding conditions based on the obtained end information; as well as The welding mechanism irradiates the end portions of the pair of coils to be welded with laser light based on the set welding conditions to integrate the coils.

2. The coil welding device according to claim 1, characterized in that: The coil welding device has a storage mechanism, which stores a plurality of welding conditions. The welding condition setting means reads out the welding condition associated with each piece of the end information from the storage means and sets the welding condition.

3. The coil welding device according to claim 1, characterized in that: The end information includes position information in three directions orthogonal to each other for the ends of a pair of the coils.

4. The coil welding device according to claim 1, characterized in that: The end information includes size information of ends of a pair of the coils.

5. The coil welding device according to claim 1, characterized in that: The end information includes shape information of the end surface of the coil, and when the welding condition setting means determines that the shape of the end surface of the coil has a corner, the irradiation position of the laser beam is set to a position shifted outward for each of the opposing end surfaces of the coil.

6. The coil welding device according to claim 1, characterized in that: The coil welding device further includes a quality inspection mechanism for determining the quality of the welded portion based on an image of the welded portion welded by the welding mechanism.

7. The coil welding device according to claim 1, characterized in that: The coil welding device further includes a quality monitoring mechanism that measures heat radiation light or reflected light from the vicinity of the laser irradiation portion during welding by the welding mechanism and monitors whether the heat radiation light or reflected light is within a predetermined range during laser irradiation.

8. The coil welding device according to claim 7, characterized in that: When it is determined by the quality monitoring mechanism that the heat radiation light or the reflected light is not within a predetermined range, the welding conditions can be adjusted during welding by the welding mechanism.

9. The coil welding device according to claim 1, characterized in that: The coil welding device further comprises a conveying mechanism, which conveys the workpiece to the welding mechanism after the end information is acquired by the end information acquisition mechanism. The coil welding device can simultaneously perform welding of the workpiece by the welding mechanism and acquisition of the end information of the next workpiece by the end information acquisition mechanism.

10. A coil welding method, characterized in that: The coil welding method comprises: A step of acquiring information on each end portion of a plurality of coils from images of ends of a pair of the coils to be welded; A step of setting welding conditions based on the obtained end information; as well as A step of integrating the end portions of the pair of coils to be welded by irradiating them with laser light based on the set welding conditions.

Images