Motor inspection device and motor inspection method

Abstract

This technology provides the ability to accurately detect the three-dimensional shape of an electric motor's coil during inspection. [Solution] The electric motor inspection device comprises: an irradiation unit that irradiates a motor, including a coil section formed by wires wound around a core, with patterned light; an image acquisition unit that acquires a pattern image of the patterned light irradiated onto the coil section; a 3D data generation unit that generates 3D shape data of the coil section using the acquired pattern image; and an inspection unit that compares the generated 3D shape data with reference data that defines the 3D shape of the coil section of a normal electric motor, and outputs the difference in the external shape of the coil section between the 3D shape data and the reference data as an inspection result.

Description

Technical Field

[0001] The present disclosure relates to an inspection device for an electric motor and an inspection method for an electric motor.

Background Art

[0002] In order to avoid contact between an electric motor and other members, an inspection device for inspecting whether the shape of the electric motor is appropriate is known. For example, Patent Document 1 discloses an inspection device for an electric motor using the light cutting method. This inspection device scans the coil ends of the electric motor with slit light including a pattern shape, images the change in the pattern shape projected onto the coil ends with a camera, and acquires the shape of the coil ends using the principle of triangulation. The inspection device compares the acquired shape of the coil ends with reference data, determines whether each measurement point of the coil ends is outside the reference data, and determines that the shape of the electric motor is appropriate if all the measurement points of the coil ends are not outside the reference data.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the coil of an electric motor includes a plurality of conducting wires that make up the coil, etc., the surface of the coil can have a complex shape including many uneven shapes. In this case, dead angles that cannot be detected by scanning slit light by the light cutting method may occur. Therefore, it is not possible to accurately detect the three-dimensional shape of the coil, which may reduce the inspection accuracy. Therefore, a technique that can inspect after accurately acquiring the three-dimensional shape of the coil is desired.

[0005] One non-limiting objective of this disclosure is to provide a technology that can accurately detect the three-dimensional shape of an electric motor coil. [Means for solving the problem]

[0006] According to one non-limiting aspect of the present disclosure, an inspection device for an electric motor is provided. The inspection device includes: an illumination unit that irradiates a motor, which includes a coil portion formed by wires wound around a core, with patterned light; an image acquisition unit that acquires a pattern image of the patterned light irradiated onto the coil portion; a three-dimensional data generation unit that generates three-dimensional shape data of the coil portion using the acquired pattern image; and an inspection unit that compares the generated three-dimensional shape data with reference data that defines the three-dimensional shape of a normal electric motor coil portion, and outputs the difference in the external shape of the coil portion between the three-dimensional shape data and the reference data as an inspection result.

[0007] The inspection device for the main unit's electric motor uses 3D shape data generated using patterned light. Therefore, it can improve the detection accuracy of the 3D shape of stator coils, which have complex shapes such as uneven surfaces, compared to methods such as light sectioning.

[0008] This disclosure can also be implemented in various forms other than electric motor inspection devices. For example, it can be implemented in the form of a compressor inspection device, a compressor inspection method, an electric motor inspection method, a control method for an electric motor inspection device, a computer program that implements the control method, a non-temporary recording medium that stores the computer program, etc. [Brief explanation of the drawing]

[0009] [Figure 1] An explanatory diagram showing the overall configuration of an inspection apparatus according to the first embodiment of this disclosure. [Figure 2] A perspective view showing the external configuration of the stator. [Figure 3] A magnified view of a portion of the stator as seen from one side in the axial direction. [Figure 4]A flowchart illustrating an inspection method for an electric motor according to the first embodiment of this disclosure. [Figure 5] A flowchart illustrating the inspection process. [Figure 6] An explanatory diagram showing the first example of a color map generated by the inspection department. [Figure 7] An explanatory diagram showing a second example of a color map generated by the inspection department. [Figure 8] An explanatory diagram showing an example of stator dimensions obtained by the inspection department. [Figure 9] A flowchart showing the inspection process in the inspection method for an electric motor according to the second embodiment. [Figure 10] An explanatory diagram showing an example of a color map generated by the inspection apparatus according to the second embodiment. [Modes for carrying out the invention]

[0010] In one non-limiting embodiment of this disclosure, the reference data may be CAD data defining the three-dimensional shape of a normal electric motor. The three-dimensional data generation unit may acquire point cloud data composed of three-dimensional coordinates using the acquired pattern image. The three-dimensional data generation unit may acquire the three-dimensional shape data by 3D modeling the acquired point cloud data. The inspection unit may compare the acquired three-dimensional shape data with the CAD data. The inspection unit may output an abnormality in the coil portion as an inspection result if the outer shape of the coil portion of the electric motor defined by the three-dimensional shape data is larger than the outer shape of the coil portion of a normal electric motor defined by the CAD data. According to this embodiment, the external shape of a three-dimensional form can be efficiently inspected by a simple method of converting point cloud data into a 3D model and comparing it with CAD data.

[0011] In addition to or in lieu of the above embodiments, the motor inspection device may further include a display unit capable of displaying the inspection results. The inspection unit may generate a color map in which, among the coil parts of the motor defined by the acquired three-dimensional shape data, locations of abnormalities in the outer shape of the coil parts are indicated in a first color, and output the generated color map as the inspection result. The display unit may display the color map. According to this embodiment, the user can easily identify any abnormalities in the coil and the location of the abnormality by viewing the color map through the display unit.

[0012] In addition to or in lieu of the above embodiments, the inspection unit may extract from the acquired three-dimensional shape data a conductive range corresponding to a conductive member and an insulating range corresponding to an insulating member. The inspection unit may generate a color map using the first color for the location of the abnormality in the coil's outer shape if that location is included in the conductive range, and using a second color different from the first color for the location of the abnormality in the coil's outer shape if that location is included in the insulating range. According to this embodiment, when there is an abnormality in the external shape of the coil section, it is possible to easily check whether or not the condition affects the quality of the electric motor by using a color map.

[0013] In addition to or in lieu of the above embodiments, the coil portion may include a conductive wire wound around the core and an insulating portion attached to the wire. The inspection unit may generate a color map using the second color for the insulating portion where the abnormality is located if the abnormality is in the insulating portion. According to this embodiment, a color map suitable for quality control of an electric motor equipped with an insulating part having insulating properties can be generated.

[0014] In addition to or instead of the above-described embodiment, the irradiation unit may be a projector. The image acquisition unit may be a stereo camera including two cameras. According to this embodiment, since it is possible to utilize stereo vision by a stereo camera and stereo vision by a combination of each monocular camera and a projector, the inspection area can be expanded.

[0015] In addition to or instead of the above-described embodiment, the inspection unit may further acquire dimensional data of the coil unit using the acquired three-dimensional shape data. According to this embodiment, in addition to the presence or absence of an abnormality in the outer shape of the coil unit, dimensional data of the coil unit can be acquired, and an inspection apparatus convenient for quality control in the manufacturing process of the electric motor can be provided.

[0016] In addition to or instead of the above-described embodiment, the electric motor may be a motor used for a compressor mounted on a vehicle, or a motor used for a compressor mounted on air-conditioning equipment including household and business use. According to this embodiment, an inspection apparatus capable of effectively detecting the three-dimensional shape of the coil unit of a motor used for a compressor mounted on a vehicle and a motor used for a compressor mounted on air-conditioning equipment including household and business use can be provided.

[0017] In addition to or instead of the above-described embodiment, the inspection method of the electric motor may further include a surface treatment step of performing a surface treatment on the electric motor to suppress reflection of light. The acquisition step may include a step of acquiring the pattern image irradiated on the electric motor subjected to the surface treatment. According to this embodiment, specular reflection or non-uniform reflection of the pattern image irradiated on a portion having high glossiness of the electric motor can be suppressed or prevented. Therefore, three-dimensional shape data of the electric motor can be stably acquired.

[0018] A. First Embodiment: Figure 1 is an explanatory diagram showing the overall configuration of an inspection apparatus 100 according to the first embodiment of this disclosure. The inspection apparatus 100 inspects whether or not there are any abnormalities in the external shape of an object to be inspected (workpiece). In the inspection by the inspection apparatus 100, a pattern projection method is used, for example, in which a predetermined pattern such as a striped pattern is projected onto the object to be inspected. The pattern projection method is sometimes also called the "striped projection method". The pattern projection method includes a phase shift method, in which pattern light is shifted at predetermined intervals and projected, and an image is acquired for each phase.

[0019] The object to be inspected by the inspection device 100 is an electric motor. The electric motor is a three-phase AC motor including a stator and rotor. The electric motor is used, for example, in a compressor mounted on a vehicle. The compressor is, for example, a scroll-type electric compressor, and is installed in the refrigerant circuit of a vehicle air conditioning system together with an evaporator, expansion valve, and condenser. Note that the electric motor is not limited to vehicle applications; for example, it may be used in a compressor mounted on air conditioning equipment that adjusts the temperature and humidity of indoor air. Air conditioning equipment includes, for example, household air conditioning equipment and commercial air conditioning equipment used in stores and buildings. The following explanation will use the case where the object to be inspected by the inspection device 100 is the stator 300 of the electric motor as an example. In Figure 1, the stator 300 is hatched for ease of understanding.

[0020] Figure 2 is a perspective view showing the external configuration of the stator 300. The axis of rotation of the rotor when it is rotatably mounted on the stator 300 is defined as the "axis P". The direction in which axis P extends is also called the "axial direction".

[0021] As shown in Figure 2, the stator 300 includes a stator core 310 and stator coils 340. In the stator 300, the ends of the wires constituting the stator coils 340 of each phase are brought out as power connection terminals. For example, the ends of the wires constituting the U-phase stator coil, V-phase stator coil, and W-phase stator coil are brought out as power connection terminals 340U, 340V, and 340W. The stator core 310 shown in Figure 2 is composed of a laminate formed by stacking multiple plate-shaped electromagnetic steel sheets. The stator core 310 is formed in a cylindrical shape that extends in the axial direction.

[0022] Figure 3 is an enlarged view of a portion of the stator 300 as seen from one side in the axial direction. The stator core 310 has a yoke 312 and a plurality of teeth 313. The yoke 312 extends in the circumferential direction. The plurality of teeth 313 are spaced apart from each other along the circumferential direction and extend radially inward from the yoke 312. Slots 317 are formed by circumferentially adjacent teeth 313. A tooth tip surface 316 is formed at the tip of each tooth 313. A space is defined radially inward from the tooth tip surface 316 in which the rotor is rotatably positioned.

[0023] As shown in Figure 2, the stator coil 340 is formed by a bundle of conductive wires that are wound around each tooth 313 of the stator core 310. In this embodiment, the stator coil 340 is formed by winding the wires around each tooth 313 in a distributed winding manner. The stator coil 340 includes a portion inserted into the slot 317 and a first coil end 340A and a second coil end 340B that protrude from the stator core 310.

[0024] The first coil end 340A is the portion of the stator coil 340 that protrudes from one end face of the stator core 310. The second coil end 340B is the portion of the stator coil 340 that protrudes from the other end face of the stator core 310. The first coil end 340A and the second coil end 340B are bundled together by a binding portion 342 formed from an insulating material such as thread or string. In addition to the binding portion 342, various insulators may be attached to the conductors of the stator coil 340 and power connection terminals 340U, 340V, 340W, etc. In this embodiment, the conductors are fitted with inter-phase insulating paper and connection point insulating to create an insulating distance between them and provide insulation. In this specification, insulating materials attached to the conductors that have insulating properties are collectively referred to as "insulating parts". The binding portion 342, inter-phase insulating paper, and connection point insulating are included in the insulating parts. The first coil end 340A, the second coil end 340B, and the insulating part are included in the “coil section” of this disclosure. The coil section has a complex shape with many irregularities because it includes a bundle of wires wound together and an insulating part. Therefore, high inspection accuracy is required to automatically inspect whether there are any abnormalities in the external shape (3D shape) of the coil section using an inspection device. Furthermore, when the coil section is inspected by a worker, human error in inspection accuracy is likely to occur, which may lead to variations in the quality of the electric motor. When the electric motor is small, it can be even more difficult to obtain the 3D shape of the coil. Therefore, this problem can be more pronounced when the electric motor is small.

[0025] Returning to Figure 1, the inspection device 100 inspects the external shape of the coil section of the stator 300. More specifically, the inspection device 100 determines whether the external shape of the first coil end 340A, the second coil end 340B, and the insulating section of the coil section shown in Figure 2 is abnormal. By detecting abnormalities in the external shape of the coil section, it is possible to determine whether there is a possibility that the case covering the motor and the motor will come into contact when the motor is mounted on the compressor.

[0026] As shown in Figure 1, the inspection device 100 comprises a support device 50, a 3D scanner 60, and a control device 80.

[0027] The support device 50 supports the stator 300, which is the object to be inspected, and the 3D scanner 60. The support device 50 comprises a turntable 52 that supports the stator 300 and a support column 54 that fixes the 3D scanner 60. The turntable 52 is driven by a motor under the control of the control device 80, which rotates the stator 300 about the axis P.

[0028] The 3D scanner 60 captures patterned light irradiated onto the object to be inspected and acquires a pattern image. The 3D scanner 60 comprises a housing 61, a projector 64, and a stereo camera including cameras 62 and 66 positioned on either side of the projector 64.

[0029] The projector 64 projects laser or LED light, which forms patterned light such as stripes or grid patterns, onto the object to be inspected. The projector 64 projects multiple types of patterned light, each with different stripe or grid pattern thicknesses, onto the object to be inspected.

[0030] Cameras 62 and 66 capture patterned light projected onto the object to be inspected and acquire patterned images. Cameras 62 and 66 acquire patterned images multiple times for each type of patterned light. The acquired patterned images are output to the control device 80. In this embodiment, the inspection apparatus 100 can utilize stereo vision using parallax from stereo cameras, as well as stereo vision using a combination of either camera 62 or camera 66 and the projector 64. With this configuration, it is possible to inspect not only the area where the field of view of camera 62 and the field of view of camera 66 overlap, but also a wide area including the field of view of each camera 62 and camera 66.

[0031] The control device 80 consists of a computer comprising a CPU 82 as a processor, memory 84 including ROM and RAM, an interface circuit 86, and a timer (not shown). These are connected bidirectionally by an internal bus 83. A display unit 88 capable of displaying inspection results is connected to the interface circuit 86. The display unit 88 is a general-purpose monitor or liquid crystal display.

[0032] Memory 84 stores various data acquired by the inspection device 100. Specifically, memory 84 stores reference data 842, 3D shape data 844, dimension data 846, and inspection results 848.

[0033] Reference data 842 is data that defines the three-dimensional shape of a normal coil section (insulating section including the first coil end 340A, the second coil end 340B, and the binding section 342). In this embodiment, reference data 842 consists of CAD data that defines the upper limit of the standard three-dimensional shape of a normal coil section. In other embodiments, reference data 842 may also be dimensional data of the external shape of a normal motor, or the three-dimensional coordinates of the external shape of a normal motor.

[0034] The 3D shape data 844 is 3D model data of the object to be inspected, generated by the 3D data generation unit 822, which will be described later. The dimension data 846 is the external dimensions of the object to be inspected, acquired by the inspection unit 824, which will be described later. The inspection result 848 is the inspection result of the object to be inspected by the inspection unit 824. In this embodiment, the inspection result 848 is the detection result of whether or not there is an abnormality in the external shape of the coil part and a color map corresponding to the detection result.

[0035] Memory 84 stores programs for executing each function realized by the inspection device 100 according to this embodiment. As shown in Figure 1, the control device 80 functions as a 3D data generation unit 822 and an inspection unit 824 when the CPU 82 reads and executes the programs stored in memory 84.

[0036] The 3D data generation unit 822 generates 3D shape data 844 of the object to be inspected using the pattern image acquired by the 3D scanner 60. The 3D data generation unit 822, for example, binarizes the acquired pattern image and assigns bit pattern information to the 3D coordinates. The 3D data generation unit 822 projects multiple pattern images onto the object to be inspected and acquires the changes in the projected pattern shape for each 3D coordinate. The 3D data generation unit 822 acquires point cloud data consisting of 3D coordinates represented by X, Y, and Z coordinates from the changes in the pattern shape based on the shape of the object to be inspected.

[0037] The 3D data generation unit 822 obtains 3D shape data 844 by converting the acquired point cloud data into a 3D model. Specifically, the 3D data generation unit 822 obtains 3D shape data 844 by converting the point cloud data into mesh data (also called polygon data) or surface data (also called geometry data), for example. By converting the point cloud data into a 3D model, the generated 3D shape data 844 can be compared with the reference data 842 composed of CAD data.

[0038] The inspection unit 824 compares the acquired 3D shape data 844 with the reference data 842 and detects the difference in the outer shape of the coil portion between the 3D shape data 844 and the reference data 842. In this embodiment, the inspection unit 824 determines that there is an abnormality in the coil portion if the outer shape of the coil portion defined by the acquired 3D shape data 844 is larger than the outer shape of the coil portion defined by the reference data 842.

[0039] The detection result from the inspection unit 824 is stored in the memory 84 as inspection result 848 and output to the display unit 88. In this embodiment, the inspection unit 824 generates a color map that visually represents the detection result, as will be described later. The generated color map is stored in the memory 84 as inspection result 848 and output to the display unit 88.

[0040] In this embodiment, the inspection unit 824 further measures the dimensions and geometric tolerances of each part of the stator 300 using the three-dimensional coordinate data included in the acquired three-dimensional shape data 844. The measured dimensions and geometric tolerances of each part may be used, for example, for detecting abnormalities in the manufacturing process, or for process capability management or quality control. The measurement results from the inspection unit 824 are stored in the memory 84 as dimension data 846.

[0041] Figure 4 is a flowchart showing an inspection method for an electric motor according to the first embodiment of this disclosure. The flowchart shown in Figure 4 is started, for example, in the manufacturing process of the stator 300, after the coil section has been formed on the stator 300. Specifically, this flowchart is started after the stator coil 340 is formed by winding a wire around each tooth 313 of the stator core 310, the coil ends 340A and 340B are bundled together with thread or string to form a binding section 342, and the interphase insulating paper and connection point insulating paper have been attached.

[0042] In step S10, a surface treatment process is performed on the stator 300. In this process, a worker or robot applies a material that suppresses the reflection of laser light or LED light to the surface of the coil. Examples of materials that suppress reflection include inorganic pigments and organic pigments.

[0043] In this embodiment, the conductor constituting the stator coil 340 is made of metal, and the surface of the stator coil 340 may have high gloss. Therefore, even when a pattern image from the projector 64 is projected onto the stator coil 340, the cameras 62 and 66 may not be able to properly acquire the pattern image. In this case, it may not be possible to acquire accurate three-dimensional shape data of the stator coil 340. In contrast, in this embodiment, by applying a surface treatment to suppress the gloss of the stator coil 340, diffuse reflection or uneven reflection of the pattern image projected onto the stator coil 340 can be suppressed or prevented. Therefore, the three-dimensional shape data 844 of the coil can be acquired stably.

[0044] It is preferable to use volatile materials for suppressing reflection. By volatilizing the material, it is possible to suppress or prevent the residue of surface treatment material remaining on the finished electric motor and affecting the quality of the motor. The surface treatment process may be performed automatically by dedicated equipment such as robots, or it may be performed manually by an operator.

[0045] In the acquisition process of step S20, the 3D scanner 60 acquires a pattern image. More specifically, the projector 64 irradiates a predetermined pattern light toward the coil portion of the stator 300. Cameras 62 and 66 capture the pattern light reflected from the coil portion and acquire a pattern image. The 3D scanner 60 outputs the acquired pattern image to the control device 80.

[0046] In this embodiment, when the 3D scanner 60 acquires a pattern image of the coil portion including the first coil end 340A, the arrangement of the stator 300 is inverted vertically. The 3D scanner 60 then acquires a pattern image of the second coil end 340B from the inverted stator 300. The inversion of the stator 300 may be done manually by an operator or automatically by a machine such as a robot. By combining the acquired pattern images of each coil end 340A and 340B, an integrated pattern image of the stator 300 is generated. However, the stator 300 does not necessarily have to be inverted. The 3D scanner 60 may acquire the pattern image of the coil portion including the first coil end 340A and the pattern image of the coil portion including the second coil end 340B at the same time by moving around the stator 300. In this embodiment, an example is shown in which the inspection device 100 is equipped with one 3D scanner 60, but the inspection device 100 may be equipped with multiple 3D scanners 60. With the inspection device 100 configured in this way, pattern images of multiple locations on a single object to be inspected can be acquired simultaneously. For example, an inspection device 100 equipped with two 3D scanners 60 corresponding to each coil end 340A and 340B can acquire the pattern image of the first coil end 340A and the pattern image of the second coil end 340B simultaneously, while the stator 300 and the 3D scanners 60 are fixed.

[0047] In the generation process of step S30, the 3D data generation unit 822 generates 3D shape data 844 of the coil portion using the acquired pattern images. More specifically, in step S32, the 3D data generation unit 822 acquires point cloud data of the coil portion using multiple pattern images acquired by the 3D scanner 60. In step S34, the 3D data generation unit 822 acquires 3D shape data 844 of the coil portion by 3D modeling the acquired point cloud data, and then proceeds to the inspection process of step S40.

[0048] Figure 5 is a flowchart of the inspection process. In step S42, the inspection unit 824 compares the acquired 3D shape data 844 with the CAD data used as reference data 842.

[0049] In step S44, the inspection unit 824 determines whether there is an abnormality in the outer shape of the coil. More specifically, the inspection unit 824 determines that there is an abnormality in the outer shape of the coil if the outer shape of the coil defined by the 3D shape data 844 is larger than the outer shape of a normal electric motor coil defined by the CAD data. The determination result by the inspection unit 824 is stored in the memory 84 as inspection result 848.

[0050] In step S46, the inspection unit 824 generates a color map showing the inspection results 848 and outputs it to the display unit 88. More specifically, the inspection unit 824 generates and displays a color map on the displayed 3D shape data that shows the locations of abnormalities in the outer shape of the coil section in predetermined colors. In step S48, the inspection unit 824 measures the dimensions of each part of the stator 300. More specifically, the inspection unit 824 calculates the dimensional data 846 of the coil section by calculating the distance using the 3D coordinates of pre-set locations in the 3D shape data 844. After completing the processing in step S48, the inspection unit 824 terminates this flow. Step S48 may be omitted if the dimensional data 846 is not required. In this case, the inspection unit 824 terminates this flow after processing in step S46.

[0051] Figure 6 is an explanatory diagram showing a first example of a color map generated by the inspection unit 824. Figure 6 shows an example of a color map CM1 generated on the 3D shape data of a stator 300A with no abnormalities in the outer shape of the coil section. For ease of understanding, Figure 6 and Figures 7 to 9, described later, include not only the color map but also reference numerals for the axis P and various parts of the stator 300.

[0052] The right side of Figure 6 shows the correspondence B1 between the color scheme of the color map CM1 and the external dimensions of the coil section. In the example in Figure 6, when the upper limit of the standard external dimensions of the coil section defined by the reference data 842 is set as the reference value ST, the color CF is assigned to the parts of the color map CM1 where the external dimensions of the acquired 3D shape data 844 are greater than the reference value ST. The color CP, which is different from color CF, is assigned to the parts where the external dimensions of the 3D shape data 844 are less than the reference value ST. For example, color CF is red, and color CP is green. In the example of the color map CM1 shown in Figure 6, the stator 300A is shown entirely in color CP (green).

[0053] Figure 7 is an explanatory diagram showing a second example of a color map generated by the inspection unit 824. Figure 7 shows an example of a color map CM2 generated on the 3D shape data of a stator 300B with an abnormality in the outer shape of the coil section. In the color map CM2, the area FP where the outer dimension of the 3D shape data 844 is larger than the reference value ST is marked with the color CF indicating the abnormality. By visually checking the color CF through the color map CM2, the user can easily confirm that there is an abnormality in the coil section of the stator 300B and the location of the abnormality in the coil section.

[0054] Figure 8 is an explanatory diagram showing an example of the dimensions of the stator 300C acquired by the inspection unit 824. Figure 8 shows the stator 300C as viewed along the axis P from one end of the stator 300C. In the example of Figure 8, the inspection unit 824 acquires the outer diameter LA and inner diameter LB of the coil section, the outer diameter LC and inner diameter LD of the stator core 310, and the width LE1 of one of the first coil ends 340A and the width LE2 of the other in the radial direction. The number of dimensions of the stator 300C to be acquired and the acquisition positions may be set arbitrarily. In this embodiment, the inspection unit 824 acquires the average, maximum, and minimum values ​​of the outer diameter LA, inner diameter LB, outer diameter LC, inner diameter LD, width LE1, and width LE2. The acquired dimension data 846 may be output to the display unit 88 along with a color map.

[0055] As described above, the inspection device 100 of this embodiment includes a 3D data generation unit 822 that generates 3D shape data 844 of the coil portion using a pattern image, and an inspection unit 824 that compares the generated 3D shape data 844 with reference data 842 and outputs the difference in the outer shape of the coil portion as an inspection result 848. The inspection device 100 of this embodiment uses 3D shape data 844 generated by the pattern projection method. Therefore, the detection accuracy of the 3D shape of the stator coil 340, which has complex shapes such as uneven shapes, can be improved compared to the light section method and the like. Consequently, the inspection device 100 can detect the 3D shape of the coil portion of the electric motor more accurately than conventional methods. Furthermore, by automating the inspection of the coil portion with complex shapes, human variation in inspection accuracy can be prevented, and variations in the quality of the electric motor can be suppressed or prevented. In addition, even for electric motors that are small compared to electric motors for vehicle drive systems, such as electric motors for vehicle air conditioning systems, the 3D shape of the coil portion can be effectively detected.

[0056] According to the inspection device 100 of this embodiment, the 3D data generation unit 822 acquires point cloud data composed of 3D coordinates, and acquires 3D shape data 844 by converting the acquired point cloud data into a 3D model. The external shape of the 3D object can be efficiently inspected by a simple method of converting point cloud data into a 3D model and comparing it with CAD data.

[0057] According to the inspection device 100 of this embodiment, the inspection unit 824 generates a color map CM2 that indicates, in color CF, the location FP of an abnormality in the outer shape of the coil portion of the electric motor, as defined by the acquired three-dimensional shape data 844. By viewing the color map CM2 via the display unit 88, the user can easily confirm that there is an abnormality in the coil portion and the location of the abnormality in the coil portion.

[0058] According to the inspection device 100 of this embodiment, the inspection unit 824 further acquires coil dimension data 846 using the acquired three-dimensional shape data 844. In addition to determining whether or not there is an abnormality in the coil, it is possible to acquire the dimensional data of the coil, thus eliminating the need for operators to measure the dimensions of the coil. Therefore, an inspection device 100 that is convenient for quality control in the manufacturing process of electric motors can be provided.

[0059] B. Second Embodiment: The configuration of the inspection apparatus 100 according to the second embodiment will be described with reference to Figures 9 and 10. The inspection apparatus 100 according to the second embodiment differs from the inspection apparatus 100 according to the first embodiment in that the algorithm for inspecting the coil portion by the inspection unit 824 is different, but the other configurations are the same as those of the inspection apparatus 100 according to the first embodiment.

[0060] In this embodiment, the inspection unit 824 uses different algorithms to inspect whether the location of the abnormality in the external shape of the stator coil 340 is included in a range corresponding to a conductive material (hereinafter also called the "conductive range") or in a range corresponding to an insulating material (hereinafter also called the "insulating range"). When the electric motor is housed in a compressor, even if there is a possibility that insulating parts such as the binding portion 342, interphase insulating paper, and connection point insulation may come into contact with the case housing the electric motor, the electric motor and the case may be insulated. Therefore, if the location of the abnormality in the external shape of the coil is an insulator such as an insulating part, in other words, if the abnormal location is included in the insulating range, the abnormality in the external shape of the coil may not affect the quality of the electric motor. In this embodiment, in order to detect such a state of the electric motor, the inspection unit 824 generates a color map CM3 based on different criteria for the conductive range and the insulating range.

[0061] Figure 9 is a flowchart showing the inspection process in the electric motor inspection method of the second embodiment. The inspection process of this embodiment differs from the electric motor inspection method of the first embodiment in that step S41 is added before step S42, and steps S44b and S46b are included instead of steps S44 and S46. The inspection device 100, as in the first embodiment, executes steps S10 to S30 to acquire the three-dimensional shape data 844 of the coil portion, and then proceeds to the inspection process shown in Figure 9.

[0062] In step S41, the inspection unit 824 extracts the conductive and insulating ranges from the acquired 3D shape data 844. In this embodiment, the inspection unit 824 detects insulating parts from the coil section, including the bundling section 342, the interphase insulating paper, and the connection point insulation, and treats the detected insulating parts as the insulating range. As a method for detecting insulating parts, for example, object detection using machine learning can be employed. As another embodiment of object detection, pattern matching may be used.

[0063] The inspection unit 824 functions as a machine learning model suitable for object detection, such as a convolutional neural network (CNN). The inspection unit 824 uses the trained training data stored in memory 84 to extract the insulating region from the acquired 3D shape data 844. In this embodiment, the inspection unit 824 treats the region of the coil other than the extracted insulating region as the conductive region. The convolutional neural network includes various machine learning models suitable for object detection, such as R-CNN, Fast R-CNN, Faster R-CNN, and YOLO.

[0064] In step S42, the inspection unit 824 compares the acquired 3D shape data 844 with the CAD data used as reference data 842, similar to the first embodiment. In step S44b, the inspection unit 824 determines whether or not there is an abnormality in the stator coil 340 using different reference values ​​for each extracted conductive range and insulating range.

[0065] As shown in Figure 9, in step S46b, the inspection unit 824 generates a color map showing the inspection results for the conductive range and insulating range, respectively, and displays it on the display unit 88. In step S48, similar to the first embodiment described above, the inspection unit 824 measures the dimensions of each part of the stator 300D and completes this flow.

[0066] Figure 10 is an explanatory diagram showing an example of a color map CM3 generated by the inspection device 100 according to the second embodiment. Figure 10 shows the stator 300D as viewed along the axis P from one end of the stator 300D. On the left side of Figure 10, the correspondence B1 between the color scheme of the color map CM3 applied to the conductive range and the external dimensions of the coil section is shown. The correspondence B1 is the same as the correspondence B1 shown in the first embodiment, so its explanation is omitted.

[0067] On the right side of Figure 10, the correspondence B2 between the color scheme of the color map CM3 applied to the insulation range and the external dimensions of the coil section is shown. As shown in Figure 10, two reference values ​​ST1 and ST2 are set in the insulation range. Reference value ST1 is the same as reference value ST in correspondence B1 and is the upper limit of the standard external dimensions of the coil section as defined by reference data 842. Reference value ST2 is the upper limit of the standard external dimensions that can be allowed for the insulator. Reference value ST2 is, for example, the value obtained by adding the distance corresponding to the upper limit of the standard external dimensions of the coil section to the outer dimensions that can be allowed for the insulator. In this embodiment, reference value ST2 is set, for example, reference value ST1 plus 0.5 mm.

[0068] As shown in Figure 10, in the color map CM3, as shown in correspondence B2, areas where the outer dimensions of the 3D shape data of the insulation range are less than the reference value ST1 are marked with the color CP, indicating normality, similar to correspondence B1. Areas where the outer dimensions of the 3D shape data of the insulation range are greater than or equal to the reference value ST2 are marked with the color CF, indicating abnormality. If the outer dimensions of the 3D shape data of the insulation range are greater than or equal to the reference value ST1 but less than the reference value ST2, a color CG, different from colors CF and CP, is marked. Note that color CG is yellow and is an example of a "second color". In the example of color map CM3 shown in Figure 10, all areas of the stator 300D other than those marked with color CG are shown with color CP (green).

[0069] Figure 10 shows an example in which the insulation range GR corresponding to the insulation portion (more specifically, the binding portion 342) is marked with color CG. The areas of the coil portion marked with color CG are larger than the upper limit of the standard external dimensions of the coil portion as defined by the reference data 842, and therefore are basically output as inspection results indicating an abnormality. However, whether the stator 300D with color CG on the coil portion is treated as a defective product or as a normal product that does not affect the quality of the motor can be set arbitrarily. Furthermore, whether or not the stator 300D is treated as a defective product can be done manually by an operator who has checked the color map CM3, or it can be done automatically by the inspection device 100.

[0070] As described above, according to the inspection device 100 of this embodiment, the inspection unit 824 generates a color map CM3 in which, if the location of the abnormality in the outer shape of the coil is within the conductive range, the location FP of the abnormality in the outer shape of the coil is indicated by color CF, and if the location of the abnormality in the outer shape of the coil is within the insulating range, the location of the abnormality in the outer shape of the coil is indicated by color CF or a different color CG. According to the inspection device 100 of this embodiment, it is possible to generate a color map CM3 that can easily inspect whether or not the abnormality in the outer shape of the coil affects the actual quality of the electric motor.

[0071] According to the inspection device 100 of this embodiment, the inspection unit 824 generates a color map CM3 that shows a different color CG from color CF and color CP when an abnormality in the outer shape of the coil is found in the insulating part. Therefore, it is possible to generate a color map CM3 that is suitable for quality control of the stator 300, which has an insulating part.

[0072] C. Other embodiments: (C1) In the first embodiment described above, an example was shown in which the 3D scanner 60 includes a projector 64 and a stereo camera. In contrast, the 3D scanner 60 is not limited to a stereo camera, but may also include a monocular camera. Furthermore, the 3D scanner 60 is not limited to a projector 64, but may use any light source capable of projecting a pattern image onto the object to be inspected.

[0073] (C2) In each of the above embodiments, the control device 80 is shown as an example in which a computer is composed of a CPU 82 and memory 84 such as ROM and RAM. In contrast, the control device 80 may be composed of a programmable logic device such as an ASIC (Application Specific Integrated Circuits) or an FPGA (Field Programmable Gate Array). The drive control processing in each of the above embodiments may be realized by the CPU executing a program stored in ROM. In this case, the program may be stored in advance in the ROM of the control device 80, or in non-volatile memory if the control device 80 includes non-volatile memory. Alternatively, the program may be recorded on an external storage medium (e.g., a USB memory) from which data can be read. The drive control processing in the above embodiments and modified examples may be distributed processing by a plurality of control circuits.

[0074] The correspondence between each component (feature) of the above embodiments and each component (feature) of the present disclosure or invention is shown below. However, each component of the embodiments is merely an example and does not limit each component of the present disclosure or invention.

[0075] The inspection device 100 of the first embodiment is an example of an "inspection device". The stator core 310 is an example of a "core". The stator 300 is an example of an "electric motor". The projector 64 is an example of an "illumination unit". Cameras 62 and 66 are examples of a "camera", "stereo camera", and "image acquisition unit". The 3D data generation unit 822 is an example of a "3D data generation unit". The 3D shape data 844 is an example of "3D shape data". The reference data 842 is an example of "reference data" and "CAD data". The inspection unit 824 is an example of an "inspection unit". The display unit 88 is an example of a "display unit". Color CF is an example of a "first color", and color CG is an example of a "second color". Color maps CM1, CM2, and CM3 are examples of "color maps". The stator coil 340, power connection terminals 340U, 340V, 340W, first coil end 340A, and second coil end 340B are examples of "conductors". The bundling section 342 is an example of "insulation". The dimension data 846 is an example of "dimensional data".

[0076] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of symbols]

[0077] 50...Support device, 52...Turret, 54...Support column, 60...3D scanner, 61...Housing, 62...Camera, 64...Projector, 66...Camera, 80...Control device, 82...CPU, 83...Internal bus, 84...Memory, 86...Interface circuit, 88...Display unit, 100...Inspection device, 300, 300A, 300B, 300C, 300D...Stator, 310...Stator core, 312...Yoke, 313...Teeth, 316... Tooth tip surface, 317... Slot, 340... Stator coil, 340A... First coil end, 340B... Second coil end, 340U, 340V, 340W... Power connection terminal, 342... Binding section, 822... 3D data generation section, 824... Inspection section, 842... Reference data, 844... 3D shape data, 846... Dimensional data, 848... Inspection result, CM1, CM2, CM3... Color map, GR... Insulation range, P... Axis line

Claims

1. An inspection device for electric motors, An illumination unit that irradiates a patterned light onto an electric motor, which includes a coil section formed by wires wrapped around a core, An image acquisition unit captures the pattern light irradiated onto the coil portion to acquire a pattern image, A 3D data generation unit generates 3D shape data of the coil portion using the acquired pattern image, The system includes an inspection unit that compares the generated three-dimensional shape data with reference data defining the three-dimensional shape of a normal electric motor coil and outputs the difference in the external shape of the coil between the three-dimensional shape data and the reference data as an inspection result. An inspection device for electric motors.

2. An electric motor inspection device according to claim 1, The aforementioned reference data is CAD data that defines the three-dimensional shape of the normal electric motor. The aforementioned three-dimensional data generation unit is Using the acquired pattern image, point cloud data composed of three-dimensional coordinates is obtained. By converting the acquired point cloud data into a 3D model, the three-dimensional shape data is obtained. The aforementioned inspection unit is The acquired 3D shape data and the CAD data are compared, If the outer shape of the coil portion of the electric motor, as defined by the three-dimensional shape data, is larger than the outer shape of the normal electric motor coil portion, as defined by the CAD data, then an abnormality in the outer shape of the coil portion is output as the inspection result. An inspection device for electric motors.

3. An electric motor inspection device according to claim 2, Furthermore, it is equipped with a display unit capable of displaying the inspection results, The inspection unit generates a color map in which, among the coils of the electric motor defined by the acquired three-dimensional shape data, locations of abnormalities in the outer shape of the coils are indicated in a first color, and outputs the generated color map as the inspection result. The display unit displays the color map. An inspection device for electric motors.

4. An inspection device for an electric motor according to claim 3, The aforementioned inspection unit is From the acquired three-dimensional shape data, the conductive range corresponding to the conductive member and the insulating range corresponding to the insulating member are extracted. If the area with an abnormality in the outer shape of the coil is included in the conductive range, the first color is used for the area with the abnormality in the outer shape of the coil; if the area with an abnormality in the outer shape of the coil is included in the insulating range, a color map is generated using a second color different from the first color for the area with the abnormality in the outer shape of the coil. An inspection device for electric motors.

5. An inspection device for an electric motor according to claim 4, The coil portion includes a conductive wire wound around the core and an insulating portion attached to the wire, The inspection unit generates a color map using the second color for the abnormal location of the insulating part if the abnormal location is the insulating part. An inspection device for electric motors.

6. An electric motor inspection device according to claim 1, The aforementioned irradiation unit is a projector, The image acquisition unit is a stereo camera including two cameras. An inspection device for electric motors.

7. An electric motor inspection device according to claim 1, The inspection unit further acquires dimensional data of the coil portion using the acquired three-dimensional shape data. An inspection device for electric motors.

8. The motor inspection device according to any one of claims 1 to 7, wherein the motor is a motor used in a compressor mounted on a vehicle, or a motor used in a compressor mounted on air conditioning equipment, including household and commercial use.

9. A method for inspecting electric motors, An acquisition step involves irradiating an electric motor, including a coil section, with patterned light, and capturing an image of the patterned light irradiated onto the coil section to obtain a pattern image. A generation step of generating three-dimensional shape data of the coil portion using the acquired pattern image, The inspection process includes comparing the generated three-dimensional shape data with reference data defining the three-dimensional shape of a normal electric motor coil, and outputting the difference in the external shape of the coil between the three-dimensional shape data and the reference data as an inspection result. Methods for inspecting electric motors.

10. A method for inspecting an electric motor according to claim 9, The aforementioned reference data is CAD data that defines the three-dimensional shape of the normal electric motor. The above production step further includes: A step of acquiring point cloud data composed of three-dimensional coordinates using the acquired pattern image, The process includes obtaining three-dimensional shape data by converting the acquired point cloud data into a 3D model, The aforementioned inspection process is, A step of comparing the acquired three-dimensional shape data with the CAD data, The process includes determining that there is an abnormality in the outer shape of the coil portion of the electric motor if the outer shape of the coil portion of the electric motor as defined by the three-dimensional shape data is larger than the outer shape of the normal coil portion of the electric motor as defined by the CAD data. Methods for inspecting electric motors.

11. A method for inspecting an electric motor according to claim 10, The inspection process further includes a step of generating and displaying a color map in which, among the coil parts of the electric motor defined by the acquired three-dimensional shape data, there are locations in the outer shape of the coil parts that are abnormal, indicated in a first color. Methods for inspecting electric motors.

12. A method for inspecting an electric motor according to claim 11, The aforementioned inspection process is, A step of extracting from the acquired three-dimensional shape data the conductive range corresponding to the conductive member and the insulating range corresponding to the insulating member, The process includes generating a color map using the first color for the area with the abnormal shape of the coil if the area with the abnormal shape of the coil is included in the conductive range, and using a second color different from the first color for the area with the abnormal shape of the coil if the area with the abnormal shape of the coil is included in the insulating range. Methods for inspecting electric motors.

13. A method for inspecting an electric motor according to any one of claims 9 to 12, Furthermore, the process includes a surface treatment step of applying a surface treatment to the electric motor to suppress light reflection. The acquisition step includes the step of acquiring the pattern image irradiated onto the electric motor that has been subjected to the surface treatment, Methods for inspecting electric motors.

Images