Coating failure detection device and coating failure determination method

Abstract

To provide a coating failure detection device capable of quantitatively evaluating the size of a foreign object which has entered a coating surface, and a related feature.SOLUTION: A coating failure detection device 1 comprises: a hollow trunk 21; an irradiation unit; a photographing unit; and an arithmetic operation unit 31. The hollow trunk 21 extends from a base end side toward a tip side. An opening edge 21E for opening an internal space of the hollow trunk 21 is provided on the tip side of the hollow trunk 21. The irradiation unit is provided in the internal space of the hollow trunk 21 and irradiates a part of a coating surface enclosed by the opening edge 21E in a state where the opening edge 21E is in contact with the coating surface. The photographing unit is provided in the internal space of the hollow trunk 21 and photographs a part of the coating surface irradiated by the irradiation unit. The arithmetic operation unit 31 calculates the size of a foreign object that has entered the part of the coating surface on the basis of image data of the part of the coating surface photographed by the photographing unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a coating defect detection device and related techniques. [Background technology]

[0002] Conventionally, techniques for inspecting defects in painted surfaces have been proposed. For example, Patent Document 1 discloses an inspection device that detects scratches and dents on the painted surface of a vehicle body, distinguishing them from other dirt and the like. Also, Patent Document 2 discloses a painted surface inspection device that automatically inspects the painted surface of an object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-184143 [Patent Document 2] Japanese Patent Publication No. 2020-159793 Summary of the Invention [Problem to be solved by the invention]

[0004] However, foreign matter (dust) may get mixed into the painted surface of a painted object. If the foreign matter mixed into the painted surface is larger than a predetermined value, it is considered a coating defect, but if the foreign matter is smaller than the predetermined value, it is not considered a coating defect.

[0005] One method for determining the above-mentioned paint defects is for a human to visually compare them using a dot gauge (standard / sample). However, when a human visually judges the paint, the judgement results tend to vary, and the judgement results of the painting company (contractor) and the client (orderer) may not match.

[0006] Therefore, an object of the present invention is to provide a paint defect detection device and related technology that can quantitatively evaluate the size of foreign matter that has become mixed into a painted surface. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides a paint defect detection device comprising: a hollow body portion extending from a base end side to a tip end side, with an opening edge portion at the tip end portion that opens up an internal space; an irradiation unit provided in the internal space that irradiates a portion of the painted surface surrounded by the opening edge portion when the opening edge portion is in contact with the painted surface; a photographing unit provided in the internal space that photographs the portion of the painted surface illuminated by the irradiation unit; and a calculation unit that calculates the size of foreign matter mixed into the portion of the painted surface based on image data of the portion of the painted surface photographed by the photographing unit.

[0008] Here, it is preferable that the photographing range of the photographing unit is the same as or larger than the opening of the opening edge portion.

[0009] It is also preferable to further include a photographing instruction unit that causes the irradiating unit to irradiate and the photographing unit to photograph at the timing when the opening edge portion comes into contact with the painted surface.

[0010] Preferably, a distal end portion of the hollow barrel is tapered from the base end toward the distal end.

[0011] It is also preferable that an auxiliary rib be provided around the opening edge portion, which contacts the contact surface together with the opening edge portion in the contact state.

[0012] Furthermore, it is preferable that a sliding shutter be provided on the side surface of the hollow barrel, which can be slid from the base end side to the tip end side to perform irradiation by the irradiation unit and photography by the photography unit.

[0013] The present invention also provides a coating defect detection method for determining defects in foreign matter using a coating defect detection device comprising: a hollow barrel portion extending from a base end side to a tip end side, with an opening edge portion at the tip end side that opens up an internal space; an irradiation unit provided in the internal space that irradiates a portion of the coated surface surrounded by the opening edge portion when the opening edge portion is in contact with the coated surface; a photographing unit provided in the internal space that photographs the portion of the coated surface illuminated by the irradiation unit; and a calculation unit that calculates the size of a foreign matter that has mixed into the portion of the coated surface based on image data of the portion of the coated surface photographed by the photographing unit, the method comprising: a) detecting at least one foreign matter that has mixed into the coated surface; a) identifying a foreign object to be judged as defective from among the objects using a paint defect detection device as a foreign object to be judged as defective; b) bringing the opening edge into contact with the painted surface so that the foreign object to be judged is surrounded by the opening edge; c) illuminating the portion of the painted surface surrounded by the opening edge with the irradiation unit and photographing it with the photographing unit; d) calculating with the calculation unit the size of the foreign object to be judged based on image data of the portion of the painted surface photographed by the photographing unit; and e) judging whether the foreign object to be judged is defective based on the size of the foreign object to be judged calculated by the calculation unit. [Effects of the Invention]

[0014] According to the coating defect detection device of the present invention, a portion of the coated surface surrounded by the opening edge of the hollow barrel is illuminated by the illumination unit and photographed by the photographing unit. The size of any foreign matter mixed into the coated surface is calculated by the calculation unit based on the image data of the portion of the coated surface photographed by the photographing unit. Therefore, by using the coating defect detection device of the present invention, it is possible to quantitatively evaluate the size of any foreign matter mixed into the coated surface.

[0015] Incidentally, the above-mentioned Patent Documents 1 and 2 do not describe at all a specific configuration for quantitatively evaluating the size of foreign matter that has become mixed into a coating surface. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a perspective view showing a coating defect detection device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a side view showing a detector that constitutes a part of the coating defect detection device. [Figure 3] FIG. 3 is a view taken along arrow III in FIG. 2. [Figure 4] A side view of Figure 2 showing the inside of the detector (camera and LED light). [Figure 5] View from the V arrow in Figure 2. [Figure 6] 10A is a perspective view of a coating defect detection device according to a modified example, as seen from diagonally below, and FIG. 10B is a perspective view of a coating defect detection device according to a modified example, as seen from diagonally above. [Figure 7] 10A and 10B are reference six-sided views of a coating defect detection device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0017] <1. Embodiment> A paint defect detection device according to an embodiment of the present invention will be described with reference to Figures 1 to 5. In the following, a paint defect detection device 1 shown in Figure 1 will be illustrated as an example of a paint defect detection device according to the present invention.

[0018] As shown in Fig. 1, the paint defect detection device 1 is configured to include a detector 2 that detects paint defects and an arithmetic and display device 3 that is wired to the detector 2. Note that the detector 2 and the arithmetic and display device 3 are each supplied with power from a power source (not shown).

[0019] 1, the detector 2 is configured to include a hollow body 21 that extends cylindrically from the base end side to the tip end side and has a tapered tip end portion. In other words, the tip end portion of the hollow body 21 is configured to taper from the base end side to the tip end side.

[0020] 1 and 5, a rectangular opening edge 21E that opens the internal space is provided on the tip side of hollow body 21. As a result, a rectangular opening 210 is formed at the tip of hollow body 21. On the other hand, as shown in FIG. 2, the base end side of hollow body 21 is closed by a blocking member 23.

[0021] The tip side of opening edge 21E is configured as an end face that can come into surface contact with the coating surface. When opening edge 21E comes into surface contact with the coating surface, opening 210 is closed, and the internal space of hollow body 21 is shielded from light and becomes a dark room.

[0022] As shown in FIGS. 4 and 5, a camera 4 and eight LED lights 5 are provided inside the hollow body 21.

[0023] Camera 4 is positioned so that its shooting direction coincides with the axial direction (longitudinal direction) of hollow body 21. This allows camera 4 to shoot an image of the outside of hollow body 21 through opening 210. As shown in FIG. 5, when opening edge 21E is viewed from directly in front, camera lens 4L of camera 4 can be seen through opening 210. Here, it is assumed that the shooting range of camera 4 is set to be the same as the size of opening 210 of opening edge 21E. Camera 4 is an example of the "shooting unit" according to the present invention.

[0024] The eight LED lights 5 are arranged at predetermined intervals in the circumferential direction so as to surround the outer periphery of the camera lens 4L of the camera 4. As described above, when the opening edge 21E comes into surface contact with the painted surface, the internal space of the hollow body 21 is light-blocked, creating a dark room. Since it is difficult for the camera 4 to take pictures in a dark room, the eight LED lights 5 illuminate the subject to be photographed (more specifically, a portion of the painted surface to be detected for paint defects). The eight LED lights 5 are an example of an "illumination unit" according to the present invention.

[0025] As shown in FIGS. 1, 3, and 5, the tapered tip of the detector 2 is provided with a shutter button 6 for illuminating the LED lights 5 and capturing an image with the camera 4. The shutter button 6 is positioned so that it protrudes slightly toward the tip beyond the opening edge 21E. This causes the shutter button 6 to be automatically pushed (depressed) when the opening edge 21E comes into contact with the painted surface. When the shutter button 6 is pushed (depressed), the eight LED lights 5 illuminate the subject to be photographed (more specifically, a portion of the painted surface surrounded by the opening edge 21E), and the camera 4 captures the illuminated subject. The shutter button 6 is an example of a "photography instruction unit" according to the present invention.

[0026] As shown in FIG. 1, the calculation and display device 3 is configured to include a calculation unit 31 and a display unit 32 controlled by a controller.

[0027] The calculation unit 31 is a processing unit that calculates the size of a foreign substance mixed into a portion of the painted surface based on image data of the portion of the painted surface (more specifically, the portion of the painted surface surrounded by the opening edge 21E) photographed by the camera 4. Specifically, the calculation unit 31 calculates the proportion of the image (number of pixels) of the foreign substance to the image (number of pixels) of the portion of the painted surface that includes the foreign substance. The calculation unit 31 then calculates the area (absolute value) of the foreign substance by multiplying the area (absolute value) of the portion of the painted surface by the calculated proportion. Note that in this embodiment, the area (absolute value) of the portion of the painted surface matches the size (area) of the opening 210 of the opening edge 21E.

[0028] The display unit 32 is configured by a known liquid crystal display or the like, and is a processing unit that displays the size (area) of the foreign matter calculated by the calculation unit 31.

[0029] Next, a coating defect detection method for detecting defects of foreign matter mixed into a coating surface using the coating defect detection device 1 described above will be described.

[0030] First, the worker visually identifies, from among a plurality of debris (foreign matter) present on the coating surface, a foreign matter that is to be judged as defective (hereinafter, also simply referred to as a "foreign matter to be judged").

[0031] Thereafter, the tip end of opening edge 21E is brought into surface contact with the painted surface so that the target foreign matter is surrounded by opening edge 21E. When opening edge 21E comes into surface contact with the painted surface, opening 210 is closed, and the internal space of hollow body 21 is shielded from light, becoming a dark room.

[0032] At the same time that opening edge 21E comes into surface contact with the painted surface, shutter button 6 is pushed (depressed) by the painted surface. Accordingly, a portion of the painted surface surrounded by opening edge 21E is illuminated by eight LED lights 5, and the illuminated portion of the painted surface is photographed by camera 4.

[0033] Image data of the part of the painted surface photographed by the camera 4 is transmitted to the calculation unit 31 of the calculation and display device 3. The calculation unit 31 calculates the size (area) of the foreign matter to be determined that has become mixed into the part of the painted surface based on the received image data.

[0034] The display unit 32 then displays the size (area) of the foreign matter to be determined calculated by the calculation unit 31. The operator determines whether or not the foreign matter to be determined is defective based on the size of the foreign matter to be determined displayed on the display unit 32. Specifically, if the foreign matter to be determined is larger than a preset value, the operator determines that the foreign matter to be determined is defective. On the other hand, if the foreign matter to be determined is smaller than the preset value, the operator determines that the foreign matter to be determined is not defective.

[0035] According to the embodiment described above, a portion of the painted surface surrounded by the opening edge 21E of the hollow barrel 21 is illuminated by the eight LED lights 5, and the illuminated portion of the painted surface is photographed by the camera 4. Then, based on the image data of the portion of the painted surface photographed by the camera 4, the size of any foreign matter mixed into the portion of the painted surface is calculated by the calculation unit 31. This makes it possible to quantitatively evaluate the size of any foreign matter mixed into the painted surface.

[0036] Furthermore, according to the above-described embodiment, the imaging range of camera 4 is set to be the same as the size of opening 210 of opening edge 21E. Therefore, a foreign object (target foreign object) surrounded by the opening of opening edge 21E falls within the imaging range of camera 4, and the target foreign object can be reliably photographed.

[0037] 2 and 3, the shutter button 6 is disposed so as to protrude slightly toward the tip side beyond the opening edge 21E. This causes the shutter button 6 to be automatically pushed (depressed) in response to the operation of bringing the opening edge 21E into contact with the painted surface. This saves the operator the trouble of having to separately push (depress) the shutter button 6.

[0038] Furthermore, according to the above-described embodiment, the distal end portion of hollow body 21 is configured to taper from the base end toward the distal end, which improves visibility during operation compared to when the distal end is not tapered, and enables the target foreign object to be detected to be more reliably enclosed by opening edge 21E.

[0039] <2. Modifications> The coating defect detection device and coating defect determination method according to the present invention are not limited to the above-described embodiments, and various modifications and improvements are possible within the scope of the claims.

[0040] For example, in the above-described embodiment, the paint defect detection device 1 is configured with two components, the detector 2 and the calculation and display device 3, but the invention is not limited to this. The paint defect detection device may be configured with the detector alone by mounting both the controller (calculation unit) and the display (display unit) on the detector.

[0041] In the above-described embodiment, the case where the shooting range of camera 4 is set to be the same as the size of opening 210 in opening edge portion 21E has been exemplified, but this is not limiting. For example, the shooting range of camera 4 may be set to be wider than the size of opening 210 in opening edge portion 21E.

[0042] Alternatively, the imaging range of camera 4 may be set to be narrower than the size of opening 210 of opening edge 21E. However, in order to more reliably capture an image of a foreign object (a foreign object to be determined) surrounded by the opening of opening edge 21E, it is preferable to set the imaging range of camera 4 to be the same as or wider than the size of opening 210 of opening edge 21E.

[0043] Furthermore, in the above-described embodiment, the detector 2 shown in Figures 1 to 5 was given as an example of the detector 2 constituting the paint defect detection device of the present invention, but this is not limited to this, and a detector 2 such as that shown in Figures 6 and 7 may also be used.

[0044] 6 and 7, the detector 2 according to the modified example is configured to include a hollow body 21 having an octagonal cross section. As in the above-described embodiment, a portion of the tip side of the hollow body 21 is configured to taper from the base end side toward the tip side. The tapered surface 21T is configured with eight surfaces according to the cross-sectional shape of the hollow body 21.

[0045] As in the above-described embodiment, a rectangular opening edge 21E that opens the internal space is provided at the tip of the hollow barrel 21. The tip side of the opening edge 21E is configured as an end face that can come into surface contact with the coating surface. Here, the opening edge 21E has a rectangular shape with four sides.

[0046] Providing a tapered surface 21T at a portion of the tip end of the hollow body 21 improves visibility when surrounding the target foreign matter. On the other hand, the diameter of the opening edge 21E is inevitably small, so when the end face of the opening edge 21E is brought into contact with the painted surface, rattles and wobble are more likely to occur than with a larger diameter.

[0047] In this regard, four auxiliary ribs 21R are provided around the periphery of the opening edge 21E according to this modification, extending outward from approximately the center of each side. A portion of the tip of each auxiliary rib 21R is configured as an end face that can come into surface contact with the painted surface. The end faces of the auxiliary ribs 21R extend outward from approximately the center of each side that constitutes the opening edge 21E so as to be continuous with the opening edge 21E.

[0048] When the end face of opening edge 21E comes into surface contact with the painted surface, the end face of auxiliary rib 21R also comes into surface contact with the painted surface. This reduces rattles and wobble when contacting the painted surface, ensuring that the end face of opening edge 21E comes into surface contact with the painted surface. As a result, light is prevented from entering hollow body 21, ensuring a darkroom within hollow body 21 when photographing a target foreign object.

[0049] 6 and 7, a connector 30 for connecting a cable (not shown) is provided on the base end side of the detector 2. As a result, the detector 2 is connected to the above-mentioned calculation and display device 3 via the cable connected to the connector 30. Also, the camera 4 and the LED light 5 provided inside the hollow body 21 are configured in the same positional relationship as in the above-mentioned embodiment.

[0050] Furthermore, in the above-described embodiment, the shutter button 6 is positioned so as to protrude slightly toward the tip side from the opening edge 21E, and the shutter button 6 is automatically pushed when the opening edge 21E comes into contact with the painted surface (i.e., illumination by the LED light 5 and photography by the camera 4 are performed), but this is not limited to this.

[0051] 6 and 7, sliding shutters 21S may be provided on the side surfaces of hollow body 21. More specifically, sliding shutters 21S may be provided on two opposing sides of hollow body 21.

[0052] Both of the two sliding shutters 21S are configured to be slidable from the base end to the tip end. With the opening edge 21E in surface contact with the painted surface, the two sliding shutters 21S are grasped from both sides and slid toward the tip end, thereby capturing an image with the camera 4. In this modified example, the LED lights 5 are always on. When the opening edge 21E surrounds the target foreign matter, the portion of the painted surface surrounded by the opening edge 21E is illuminated by the lit LED lights 5.

[0053] In this modification, the sliding shutters 21S are configured with a mechanism that physically does not function on its own (more specifically, a mechanism that does not contact a tactile switch, not shown). Therefore, in this modification, photography by the camera 4 is performed only when the two sliding shutters 21S are slid simultaneously. [Explanation of symbols]

[0054] 1. Paint defect detection device 2. Detector 3 Calculation display device 4. Camera 4L camera lens 5 Light 6 Shutter button 21 Hollow body 21E Opening edge 21R Auxiliary rib 21S sliding shutter 21T tapered surface 23 Closure member 31 Arithmetic section 32 Display section 210 Aperture

Claims

1. A coating defect detection device, a hollow body portion extending from a base end side toward a tip end side, and having an opening edge portion that opens an internal space provided at the tip end side; an irradiation unit provided in the internal space and configured to irradiate a portion of the coating surface surrounded by the opening edge portion when the opening edge portion is in contact with the coating surface; an imaging unit that is provided in the internal space and that images the portion of the painted surface illuminated by the illumination unit; a calculation unit that calculates the size of foreign matter mixed into the portion of the painted surface based on image data of the portion of the painted surface photographed by the photographing unit; A coating defect detection device comprising:

2. 2. The coating defect detection device according to claim 1, wherein the photographing range of the photographing unit is the same as or larger than the opening of the opening edge portion.

3. 3. The coating defect detection device according to claim 1, further comprising an imaging instruction unit that causes the irradiation unit to irradiate and the imaging unit to photograph at the timing when the opening edge portion comes into contact with the coating surface.

4. 2. The coating defect detecting device according to claim 1, wherein a tip portion of the hollow barrel is tapered from the base end toward the tip.

5. 5. The coating defect detecting device according to claim 4, wherein an auxiliary rib is provided around the edge of the opening, and contacts the contact surface together with the edge of the opening in the contact state.

6. 2. The coating defect detection device according to claim 1, wherein a sliding shutter is provided on the side of the hollow barrel portion, which can be slid from the base end side to the tip end side to perform irradiation by the irradiation unit and photography by the photography unit.

7. a hollow body portion extending from a base end side toward a tip end side, and having an opening edge portion that opens an internal space provided at the tip end side; an irradiation unit provided in the internal space and configured to irradiate a portion of the coating surface surrounded by the opening edge portion when the opening edge portion is in contact with the coating surface; an imaging unit that is provided in the internal space and that images the portion of the painted surface illuminated by the illumination unit; a calculation unit that calculates the size of foreign matter mixed into the portion of the painted surface based on image data of the portion of the painted surface photographed by the photographing unit; A coating defect determination method for determining defects of the foreign matter using a coating defect detection device comprising: a) identifying a foreign substance to be judged as a defect using a coating defect detection device from among at least one foreign substance mixed in the coating surface as a foreign substance to be judged; b) bringing the edge of the opening into contact with the painted surface so that the target foreign matter is surrounded by the edge of the opening; c) illuminating the portion of the painted surface surrounded by the opening edge portion with the illumination unit and photographing the portion with the photographing unit; d) calculating the size of the target foreign matter by the calculation unit based on image data of the portion of the painted surface photographed by the photographing unit; e) determining whether the target foreign matter is defective or not based on the size of the target foreign matter calculated by the calculation unit; A coating defect determination method comprising:

Images