Apparatus for inspecting bottom surface of transformer tank

Abstract

To provide an inspection device of a bottom surface of a transformer tank capable of reducing a burden of a worker and stabilizing inspection quality.SOLUTION: The inspection device 100 inspects the coating state of the bottom surface of the transformer tank 200. The inspection device 100 includes an imaging unit 180 configured to be capable of imaging the bottom surface of the transformer tank 200 after being coated, and an image processing unit 162 that automatically inspects the coating state of the bottom surface of the transformer tank 200 by performing predetermined image processing on an image for inspection captured by the imaging unit 180. The imaging section 180 includes an articulated robot 110 to which a wrist unit 170 is attached, an image sensor 120 attached to the distal end of the wrist unit 170, and an imaging control section 161 that controls the articulated robot 110 and the image sensor 120.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to an inspection device for the bottom of a transformer tank. [Background technology]

[0002] Conventionally, in a painting line where the transformer tank that forms the outer shell of a transformer is painted, there is an inspection process for inspecting the paint condition of the bottom surface of the painted transformer tank. In such an inspection process, the transformer tank is transported while suspended, for example, on a rail that extends along the ceiling of a building, and a worker crawls under the suspended transformer tank to visually inspect the paint condition of the bottom surface.

[0003] Such conventional inspections by workers can impose a heavy burden on the workers and cannot be said to be highly safe. Furthermore, there is a risk that the inspection results may vary due to individual differences between workers, leading to human error, and there is also room for improvement in terms of the stability of the inspection quality. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-100395 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, we provide an inspection device for the bottom of a transformer tank that can reduce the burden on workers and stabilize the inspection quality. [Means for solving the problem]

[0006] The transformer tank inspection device of this embodiment inspects the paint condition of the bottom surface of the transformer tank and includes an imaging unit configured to be able to image the bottom surface of the transformer tank after it has been painted, and an image processing unit that automatically inspects the paint condition of the bottom surface of the transformer tank by performing predetermined image processing on the inspection image captured by the imaging unit. The imaging unit includes an articulated robot equipped with a wrist unit, an image sensor attached to the tip of the wrist unit, and an imaging control unit that controls the articulated robot and the image sensor. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a transformer tank and an inspection device according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing an example of an inspection range on the bottom, side, and inner surface of a transformer tank according to the first embodiment. [Figure 3] FIG. 1 is a diagram showing an example of a mode of transportation of a transformer tank according to the first embodiment. [Figure 4] 1 is a perspective view of the transformer tank according to the first embodiment, seen from the bottom side. [Figure 5] Part 2 is a perspective view of the transformer tank according to the first embodiment, seen from the bottom side. [Figure 6] FIG. 10 is a diagram showing a specific example of a paint state inspection result that is rejected according to the first embodiment. [Figure 7] FIG. 1 is a diagram showing an example of the configuration of an anti-sway mechanism according to the first embodiment; [Figure 8] FIG. 1 is a diagram showing an example of specific content of processing executed in an inspection process by the inspection device according to the first embodiment; [Figure 9] FIG. 10 is a diagram illustrating the configuration of a transformer tank and an inspection device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, several embodiments will be described with reference to the drawings. Note that substantially the same components in the respective embodiments will be denoted by the same reference numerals, and the description thereof will be omitted. (First embodiment) The first embodiment will be described below with reference to FIGS.

[0009] 1, the inspection device 100 of this embodiment is an example of an inspection device for a transformer tank 200, which is intended to inspect the paint condition of the bottom surface of the transformer tank 200. The transformer tank 200 includes a peripheral wall member 210 having a large number of heat dissipation ribs R, and frame members 220 and 230 welded to both the upper and lower ends of the peripheral wall member 210, and has an overall rectangular box shape.

[0010] The transformer tank 200 is a sealed type closed by a lid member 240 that covers the upper frame member 220 and a bottom member 250 that covers the lower frame member 230, and serves as the outer casing of a wet transformer inside which the transformer body (not shown) is immersed in insulating oil. The transformer tank 200 is manufactured by assembling each of its constituent members, namely, the peripheral wall member 210, the frame members 220 and 230, the lid member 240, and the bottom member 250, into the outer casing through a pressing process, a welding process, etc., and then by manufacturing the tank through a pickling process, a painting process, etc.

[0011] The inspection device 100 of this embodiment is used in the painting process among the various steps involved in the manufacturing of the above-described transformer tank 200. In the painting process, the transformer tank 200 is painted using a powder coating device. The inspection device 100 is a device that inspects the painted condition of the surface of the bottom member 250 of the transformer tank 200 that is exposed to the outside after the painting has been performed, i.e., the bottom surface of the transformer tank 200.

[0012] The inspection range that is the target of inspection by the inspection device 100 is the entire bottom surface of the transformer tank 200, as shown by the dotted line in area A1 in Fig. 2. Note that the entire side surface of the transformer tank 200, as shown by the dotted line in area A2 in Fig. 2, and a partial area of ​​the inner surface of the transformer tank 200, as shown by the dotted line in area A3 in Fig. 2, are inspected visually by an operator, rather than inspected by the inspection device 100. In other words, areas A2 and A3 are visual inspection ranges, and are not the target of inspection by the inspection device 100.

[0013] The painting process includes various steps such as receiving, pre-treatment, water-draining drying oven, painting, baking drying oven, cooling, inspection, and unloading. Inspection of the bottom surface of the transformer tank 200 using the inspection device 100 is carried out during the above-mentioned inspection process. As shown in Figures 1 and 3, when the transformer tank 200 is transported between the above-mentioned steps, it is suspended by a suspension member 400 such as a chain from a rail 300 that is installed, for example, along the ceiling of a building.

[0014] 1, the inspection device 100 includes an articulated robot 110, an image sensor 120, left and right travel axes 130, a monitor 140, an operation panel 150, and a control device 160. The articulated robot 110 is, for example, a six-axis vertical articulated robot, and has a wrist unit 170 attached to the end of its arm. The wrist unit 170 is, for example, an i-WRIST, and can set the end of the arm of the articulated robot 110 to various postures. The image sensor 120 is, for example, a camera, and is attached to the end of the wrist unit 170.

[0015] The base end of the articulated robot 110 is attached to the left-right traveling shaft 130, which allows the articulated robot 110 to move left-right in FIG. 1, that is, in a direction along one side of the bottom surface of the transformer tank 200. In this way, the left-right traveling shaft 130 functions as a moving device that moves the articulated robot 110 in a direction along at least one of the sides of the bottom surface of the transformer tank 200.

[0016] The control device 160 is mainly configured as a computer equipped with a CPU, ROM, RAM, etc., and controls the overall operation of the inspection device 100. The control device 160 has functional blocks such as an imaging control unit 161 and an image processing unit 162. Each of these functional blocks is realized by the CPU of the control device 160 executing a computer program stored in a ROM or the like to perform processing corresponding to the computer program, that is, by software. Note that at least a portion of each functional block may be configured to be realized by hardware.

[0017] The imaging control unit 161 controls the operations of the articulated robot 110, the image sensor 120, and the left and right traveling axis 130. In this case, the imaging unit 180 is made up of the articulated robot 110, the image sensor 120, the left and right traveling axis 130, the wrist unit 170, and the imaging control unit 161. The imaging unit 180 is configured to be able to capture images of the bottom surface of the transformer tank 200 after it has been painted. There are about 50 locations that need to be imaged for inspection, and imaging is required in various postures.

[0018] As shown in FIGS. 4 and 5, legs 251 are provided on the bottom member 250 of the transformer tank 200. To check the paint condition of each part inside the legs 251, the imaging unit 180 needs to go around and capture images of the legs 251. In this embodiment, the imaging unit 180 uses a wrist unit 170 whose arm tip can be positioned in various positions, so that the imaging unit 180 can go around and capture images of the legs 251 and can also capture images of various parts of the bottom surface of the transformer tank 200 from the front. Note that in FIG. 4, multiple arrows indicate an example of the imaging direction. Furthermore, a configuration using the wrist unit 170 has the advantage of making it easier to adjust the imaging angle for the target part.

[0019] The control device 160 can display various information related to the inspection performed by the inspection device 100, such as the inspection results, on the monitor 140. The control device 160 can accept various operations from the user via the operation panel 150. The image processing unit 162 performs predetermined image processing using AI such as VisionProDL on the inspection image captured by the imaging unit 180, thereby automatically inspecting the coating condition of the bottom surface of the transformer tank 200.

[0020] The inspection contents of the inspection device 100 include the presence or absence of paint, abnormal paint, etc. Specific examples of inspection results that will result in a failure are shown in Figure 6. In Figure 6, (1) is "blank," which means the paint is thinner than specified, (2) is "unpainted," which means no paint is applied, (3) is "foreign matter," which means paint has been applied over foreign matter such as dirt, and (4) is "sagging," which means paint has dripped.

[0021] The pass / fail judgment of the inspection by the inspection device 100 is performed using AI image processing by the image processing unit 162. In this case, the information provided to the AI ​​may include images of NG products with problems in the coating state, i.e., images corresponding to the above-mentioned failure cases, and images of OK products with no problems in the coating state.

[0022] The inspection device 100 displays NG areas where there are problems with the coating state, areas where the pass / fail judgment is unclear, etc. on the monitor 140, allowing the worker to visually check. In this case, for areas where the pass / fail judgment is unclear, that is, areas that are at an intermediate level between OK and NG, the worker can make a judgment without the inspection device 100 automatically judging them as NG.

[0023] In this case, the inspection device 100 inspects multiple models of transformer tanks 200, for example, approximately 20 models. In other words, there are multiple types of transformer tanks 200, for example, approximately 20 types, that are inspected by the inspection device 100. The transformer tanks 200 have different bottom shapes and sizes, depending on the type. Therefore, the imaging control unit 161 of the inspection device 100 uses the image sensor 120 to capture and recognize the four corners of the bottom of the transformer tank 200, and adjusts the imaging range, which is the range within which the inspection image is captured, based on the recognition results. This enables the inspection device 100 to reliably inspect the paint condition of the bottom of multiple types of transformer tanks 200.

[0024] The inspection device 100 is equipped with an anti-sway mechanism 190 as shown in Fig. 7. The transformer tank 200 is transported in a suspended state from the previous process to the inspection process, so there is a possibility that the transformer tank 200 may be in a swaying state when transported to the inspection process. The anti-sway mechanism 190 is configured to be able to prevent the transformer tank 200 from swaying.

[0025] Specifically, the anti-sway mechanism 190 is configured to stop the vibration of the transformer tank 200 and keep it still by clamping two side surfaces of the transformer tank 200 from both sides with movable clamping members 191. The imaging control unit 161 is configured to capture an image of the bottom surface of the transformer tank 200 with the image sensor 120 after the anti-sway mechanism 190 has stopped the vibration of the transformer tank 200.

[0026] Next, the specific contents of the processing executed in the inspection process by the inspection device 100 configured as described above will be described with reference to FIG. When the transformer tank 200 to be inspected is transported from the previous process to the inspection process, the inspection device 100 executes a series of processes as shown in Fig. 8. In step S101, the type of the transformer tank 200, that is, the model, is determined.

[0027] In step S102, the anti-sway mechanism 190 performs an anti-sway operation to stop the vibration of the transformer tank 200. In step S103, the four corners of the bottom surface of the transformer tank 200 are imaged and recognized. Then, based on the recognition result and the model of the transformer tank 200 to be inspected, the imaging range, which is the range within which the inspection image is captured, is adjusted. In step S104, the paint condition of the bottom surface of the transformer tank 200 is inspected.

[0028] In step S105, it is determined whether the result of the inspection carried out in step S104 is OK. If the inspection result is OK, step S105 becomes "YES" and the process proceeds to step S106. In step S106, the inspection process is passed, and then this series of processes ends. On the other hand, if the inspection result is NG, step S105 becomes "NO" and the process proceeds to step S107.

[0029] In step S107, an alarm is sounded indicating that there is a problem with the paint condition. The alarm is sounded, for example, by displaying a warning on the monitor 140 or outputting a warning sound from a speaker (not shown). After step S107 is executed, the process proceeds to step S108, where the paint is corrected for the defective area. The paint correction can be performed automatically using the articulated robot 110, or can be performed manually by an operator. After step S108 is executed, this series of processes ends.

[0030] According to the present embodiment described above, the following effects can be obtained. The inspection device 100 includes an imaging unit 180 configured to be able to capture an image of the bottom surface of the transformer tank 200 after it has been painted, and an image processing unit 162 that automatically inspects the paint condition of the bottom surface of the transformer tank 200 by performing predetermined image processing on the inspection image captured by the imaging unit 180. The imaging unit 180 includes an articulated robot 110 to which a wrist unit 170 is attached, an image sensor 120 attached to the tip of the wrist unit 170, and an imaging control unit 161 that controls the articulated robot 110 and the image sensor 120.

[0031] According to the above configuration, the paint condition of the bottom surface of the transformer tank 200 is automatically inspected by the inspection device 100 during the inspection process. This eliminates the need for the worker to enter under the suspended load, frees the worker from the conventional work that requires nerves and physical strength, and prevents the occurrence of variability in judgment and human error due to individual differences between workers. In other words, the above configuration reduces the burden on the worker, improves worker safety, and further improves the stability of inspection quality. Therefore, according to this embodiment, the effects of reducing the burden on the worker and stabilizing inspection quality are achieved.

[0032] In this embodiment, the imaging unit 180 is configured with a wrist unit 170 that can position the arm tip of the articulated robot 110 in various positions, so that various locations on the bottom surface of the transformer tank 200 can be imaged from the front, and this movement can be performed at a relatively high speed.

[0033] Furthermore, a configuration including the wrist unit 170 can maintain good operability even in a configuration using an articulated robot 110 where singular points occur and teaching becomes difficult. Furthermore, a configuration including the wrist unit 170 makes it possible to perform tasks such as imaging in a small space, so the inspection device 100 can be installed without any problems within the constraints of installation height, area, etc. at the site where the inspection process is carried out.

[0034] In this embodiment, the imaging unit 180 includes a left-right traveling axis 130 that moves the articulated robot 110 in a direction along at least one of the sides of the bottom of the transformer tank 200. This configuration makes it possible to inspect transformer tanks 200 with a relatively small bottom size as well as those with a relatively large bottom size. Furthermore, this configuration makes it possible to move the articulated robot 110 so that the image sensor 120 is located within a dust-proof area during periods when inspections are not being performed, thereby preventing the image sensor 120 from becoming dirty.

[0035] In this embodiment, the inspection device 100 further includes an anti-sway mechanism 190 that prevents the transformer tank 200 from shaking. This configuration makes it possible to keep the imaging position of the imaging unit 180 constant, thereby further stabilizing the quality of the paint condition inspection. Furthermore, with the above configuration, if the paint condition inspection result is NG, the paint in the defective area can be easily corrected, i.e., paint repair can be easily performed.

[0036] In this embodiment, the imaging control unit 161 uses the image sensor 120 to capture and recognize the four corners of the bottom surface of the transformer tank 200, and adjusts the imaging range, which is the range within which the inspection image is captured, based on the recognition result. In this way, even if there are many types of transformer tanks 200 to be inspected, the inspection device 100 can reliably inspect the coating conditions of the bottom surfaces of these many types of transformer tanks 200.

[0037] (Second embodiment) The second embodiment will be described below with reference to FIG. As shown in Fig. 9, the inspection device 101 of this embodiment differs from the inspection device 100 of the first embodiment in that it includes a pillar-shaped member 131 instead of the left and right traveling shaft 130. The pillar-shaped member 131 is provided so as to extend upward from the floor surface of the building. In this case, the base end of the articulated robot 110 is fixed to the side surface of the pillar-shaped member 131. As a result, the articulated robot 110 is provided in a fixed state at a predetermined position.

[0038] With this configuration, although the articulated robot 110 cannot be moved as in the first embodiment, the position and posture of the arm tip of the articulated robot 110 can be changed, and therefore the imaging unit 180 can capture images of various locations on the bottom surface of the transformer tank 200. Therefore, with this embodiment as well, it is possible to obtain the same effects as with the first embodiment.

[0039] (Other embodiments) The present invention is not limited to the embodiments described above and illustrated in the drawings, but can be arbitrarily modified, combined, or expanded without departing from the spirit of the invention. The numerical values ​​and the like shown in the above embodiments are examples and are not limited to these. The number of axes of the articulated robot 110 is not limited to six, and may be any number that can reliably capture an image of the area to be inspected.

[0040] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0041] 100, 101... inspection device, 110... articulated robot, 120... image sensor, 130... left and right traveling axis, 161... imaging control unit, 162... image processing unit, 170... wrist unit, 180... imaging unit, 190... anti-vibration mechanism

Claims

1. An inspection device for inspecting the paint condition of the bottom surface of a transformer tank, an imaging unit configured to be able to image the bottom surface of the transformer tank after it has been painted; an image processing unit that automatically inspects the coating condition of the bottom surface of the transformer tank by performing predetermined image processing on the inspection image captured by the imaging unit; Equipped with The imaging unit an articulated robot equipped with a wrist unit; an image sensor attached to the tip of the wrist unit; an imaging control unit that controls the articulated robot and the image sensor; A transformer tank bottom inspection device comprising:

2. The imaging unit 2. The transformer tank bottom surface inspection device according to claim 1, further comprising a movement device that moves the articulated robot in a direction along at least one of the sides of the bottom surface of the transformer tank.

3. The transformer tank is adapted to be transported in a suspended state, The transformer tank further includes an anti-sway mechanism for preventing the transformer tank from swaying.

3. The transformer tank bottom inspection device according to claim 1, wherein the imaging control unit images the bottom surface of the transformer tank using the image sensor after the anti-sway mechanism has immobilized the transformer tank.

4. 3. The transformer tank bottom inspection device according to claim 1, wherein the imaging control unit uses the image sensor to image and recognize four corners of the bottom surface of the transformer tank, and adjusts an imaging range, which is a range in which the inspection image is captured, based on the recognition result.

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