Visual inspection device for shaft member

Abstract

To provide an inspection device for shaft member capable of automatically performing a high-level visual inspection.SOLUTION: An outer peripheral surface of a shaft member 9 is line-scanned by imaging means 8 while the shaft member 9 is rotated with rotating means 13, A pair of lights 5a and 5b are positioned diagonally above shaft member 9 at different angles, and the shaft member 9 is illuminated by the lights 5a and 5b. The imaging means 8 can clearly capture a scratch on the outer peripheral surface of the shaft member 9 by imaging an oblique axial position of the shaft member 9 in the center.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an apparatus for inspecting the appearance of a shaft member such as an actuator rod. [Background technology]

[0002] Electric linear actuators have been used for adjusting the height of electric beds and the angles of the back and knees. These actuators are devices that generate thrust by converting the rotational motion of a motor into the linear motion of a rod via gears and screws (see Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 9-191606

[0004] As shown in FIG. 7, a packing 103 is attached between a rod 101 that moves linearly and a casing 102 of the actuator in order to improve the waterproofing of the casing 102.

[0005] The rod 101, which moves linearly, slides with its outer circumferential surface in contact with this packing 103. Therefore, if there is a scratch on the outer circumferential surface of the rod 101, the packing 103 in contact with it will also be damaged, resulting in a decrease in the waterproof performance of the actuator. Therefore, after the rod 101 is manufactured, it becomes necessary to inspect the outer circumferential surface of the rod 101 for scratches. Summary of the Invention [Problem to be solved by the invention]

[0006] Generally, visual inspection of rods is often performed visually by workers. Visual inspection depends on the skill of the worker, which leads to variations in the quality of the inspection. Furthermore, visual inspection takes a long time, which leads to reduced productivity.

[0007] Therefore, an object of the present invention is to automate the visual inspection of rods while improving the inspection accuracy, thereby achieving a high level of uniformity in inspection quality, shortening the inspection time, and increasing productivity. [Means for solving the problem]

[0008] The invention described in claim 1 is characterized in that it comprises a support means for supporting both ends of an axial member, a rotation means for rotating the support means, an imaging means for imaging the rotating axial member, and an illumination means for illuminating the axial member, and the imaging means is positioned so that the center of the imaging position by the imaging means is at the diagonal axis position of the axial member.

[0009] The invention described in claim 2 is characterized in that the lighting means described in claim 1 consists of two bar lights for inspecting the presence or absence of linear or circumferential scratches on the shaft member, and the two bar lights are arranged at different angular positions diagonally upward along the longitudinal direction of the shaft member.

[0010] The invention described in claim 3 is characterized in that it comprises support means for supporting both ends of an axle member, rotation means for rotating the support means, imaging means for imaging the rotating axle member, and illumination means for illuminating the axle member, wherein the imaging means is positioned so that the center of the imaging position by the imaging means is at the top axis position of the axle member, and the illumination means comprises a focusing illuminator with an umbrella portion for inspecting the axle member for the presence or absence of dents or scratches, and a light is placed within the umbrella portion, and the light from the light is reflected on the inner surface of the umbrella portion to illuminate the axle member, and the umbrella portion is provided with a window portion that enables the imaging means to image the axle member.

[0011] The invention as set forth in claim 4 is characterized in that the imaging of the shaft member by the imaging means as set forth in any one of claims 1 to 3 is line scanning.

[0012] The invention described in claim 5 is characterized in that the shaft member described in either claim 1 or claim 3 has a hollow tubular shape, and the support means is configured to include a pair of conical portions inserted into the hollow portion of the shaft member to support the shaft member, and one of the pair of conical portions is equipped with an electric cylinder for moving it back and forth.

[0013] The invention as set forth in claim 6 is characterized in that the rotating means as set forth in either claim 1 or claim 3 is configured to include a rotating electric motor that rotates the supporting means.

[0014] The invention as set forth in claim 7 is characterized in that it is configured to include the shaft member as set forth in either claim 1 or claim 3, and a blackout curtain that covers the illumination means and the imaging means. [Effects of the Invention]

[0015] According to the invention of claim 1, the appearance of the shaft member can be inspected without relying on visual inspection by an operator, which makes it possible to standardize the quality of the inspection and reduce the number of inspection steps.

[0016] In addition, by adjusting the center of the imaging position of the imaging means to be the diagonal axis position of the shaft member, the surface of the shaft member illuminated by the lighting means can be clearly imaged, thereby improving the quality of the inspection.

[0017] According to the invention described in claim 2, the illumination from the two bar lights can be prevented from being reflected by the shaft member and directly incident on the imaging means, thereby reliably preventing the reflected light from the illumination from impeding the inspection of linear scratches and circumferential scratches on the shaft member.

[0018] According to the invention of claim 3, the window provided in the umbrella part can be used to capture an image of the shaft member by the imaging means. Also, lighting suitable for inspecting the presence or absence of dents can be applied to the shaft member.

[0019] According to the invention as set forth in claim 4, the entire outer periphery of the shaft member can be inspected.

[0020] According to the invention as set forth in claim 5, the shaft member can be supported with a simple structure.

[0021] According to the invention as set forth in claim 6, the supported shaft member can be rotated with a simple structure.

[0022] According to the invention of claim 7, it becomes easier to inspect the shaft member for linear scratches, circumferential scratches or dent scratches, and the quality of inspection of the shaft member can be improved. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a perspective view showing a first structure of a visual inspection device according to the present invention. [Figure 2] 1 is a plan view showing a first structure of a visual inspection device according to the present invention. [Figure 3] 3 is a schematic diagram showing the positional relationship between lighting and a shaft member in a first structure of the visual inspection device according to the present invention. FIG. [Figure 4] FIG. 10 is a perspective view showing a second structure of the visual inspection device according to the present invention. [Figure 5] FIG. 10 is a plan view showing a second structure of the visual inspection device according to the present invention. [Figure 6] 10 is a schematic diagram showing the positional relationship between lighting and a shaft member in a second structure of the visual inspection device according to the present invention. FIG. [Figure 7] FIG. 2 is a vertical cross-sectional view showing a part of the actuator. DETAILED DESCRIPTION OF THE INVENTION

[0024] An embodiment of the present invention will be described below with reference to Figures 1 and 2. Figure 1 is a perspective view showing a first structure of a visual inspection device according to the present invention. In Figure 1, 1a to 1d denote vertical supports erected at the four corners of a bottom plate 2 of the visual inspection device A, and 3a, 3b, 3c, and 3d denote horizontal supports fixed to the vertical supports 1a, 1b, 1c, and 1d, respectively.

[0025] Reference numeral 4a denotes a mounting plate that bridges between horizontal supports 3a and 3c, and 4b denotes a mounting plate that bridges between horizontal supports 3b and 3d. Reference numeral 5a denotes a light that is fixed to the underside of mounting plate 4a, and 5b denotes a light that is fixed to the underside of mounting plate 4b. The lights 5a and 5b are bar lights that can change the direction of light illumination as needed using angle adjustment mechanisms 5a1, 5b1, 5c1, and 5d1 attached to each of the horizontal supports 3a to 3d.

[0026] Reference numerals 6a and 6b denote central vertical supports erected on the bottom plate 2, and reference numeral 7 denotes a central horizontal support fixed between the central vertical supports 6a and 6b. Reference numeral 8 denotes an imaging means (camera) attached to the central horizontal support 7, and the imaging direction is downward.

[0027] Reference numeral 9 denotes a shaft member arranged below the imaging means 8, and has a hollow tube shape. An example of such a shaft member is a shaft member that constitutes an electric linear actuator. Reference numeral 10 denotes a support means that supports the shaft member 9 from both longitudinal ends, and is composed of a pair of conical portions 11a and 11b that are inserted into the hollow portion from both ends of the shaft member 9 and support it. The conical portion 11b is equipped with an electric cylinder 12 that moves it forward or backward along the longitudinal direction of the shaft member 9. The conical portion 11b is attached to the electric cylinder 12 so as to be rotatable.

[0028] Reference numeral 13 denotes a rotation means that rotates conical portion 11a to rotate shaft member 9 around the axis between conical portion 11b, and is constituted by a rotation motor 14. Reference numerals 15a and 15b denote arms on the tips of which shaft member 9 is temporarily placed when shaft member 9 is supported by conical portions 11a and 11b, and arms 15a and 15b have their base ends fixed via fixing member 16 and connecting portion 17 to bearing mechanism 18 fixed on bottom plate 2.

[0029] Fig. 2 is a side view showing the left side of the visual inspection device A shown in Fig. 1. In Fig. 2, the shaft member 9 is temporarily placed on the arm 15a (15b), and by inserting the conical portion 11a (11b) shown in Fig. 1 into the hollow portion 9a of the shaft member 9, the shaft member 9 is slightly lifted from the tip end of the arm 15a (15b), and is released from contact with the arm 15a (15b).

[0030] In other words, the radial center position of the conical portion 11a (11b) is located slightly above the radial center position of the hollow portion 9a of the shaft member 9, so that when the conical portion 11a (11b) is inserted into the hollow portion 9a of the shaft member 9, the shaft member 9 is lifted from above the arm 15a (15b) by the conical portion 11a (11b) and rises slightly.

[0031] By releasing the contact between the shaft member 9 and the arm 15a (15b), when the conical portion 11a (11b) is rotated by the rotating motor 14, the shaft member 9 rotates smoothly above the arm 15a (15b) without coming into contact with it.

[0032] As shown in FIG. 2, the imaging means 8 is disposed at a position where its center position X is shifted by h [mm] from the center position Y of the shaft member 9. When the radius of the shaft member 9 is 13.5 [mm], the position of the imaging means 8 is adjusted so that h is in the range of 3 [mm] to 7 [mm], preferably in the range of 4 [mm] to 6 [mm]. In other words, by shifting the center position of the imaging position by the imaging means 8 from the center position Y of the shaft member 9 by 22% to 52% of the radius of the shaft member, preferably by 29% to 45%, the imaging means 8 captures an image centered on an axis position P that is offset from the top axis position of the shaft member 9. In the present invention, this axis position offset from the top is referred to as an oblique axis position.

[0033] Fig. 3 shows angles θ1 and θ2 formed by the two bar lights 5a and 5b shown in Fig. 2 and the shaft member 9. As shown in Fig. 3, the two bar lights 5a and 5b are arranged diagonally above the shaft member 9, and the angle θ1 between the line connecting the shaft member 9 and each bar light 5a and the vertical direction of the shaft member 9 is arranged to be in the range of 40° to 50° (optimum angle). More preferably, it is arranged to be in the range of 43° to 47° (optimum angle).

[0034] Furthermore, the angle θ2 between the line connecting the shaft member 9 and each bar light 5b and the vertical direction of the shaft member 9 is set to be in the range of 55° to 75° (optimum angle), and more preferably in the range of 57° to 61° (optimum angle).

[0035] In other words, the two bar lights 5a, 5b are arranged at different angular positions diagonally above the shaft member 9. As described above, by arranging the imaging means 8 so that the diagonal axis position P of the shaft member 9 is the center of the imaging position, and by arranging the bar lights 5a, 5b at the appropriate angle or optimal angle, it becomes possible for the imaging means 8 to clearly image linear scratches and circumferential scratches on the outer peripheral surface of the shaft member 9.

[0036] In the present invention, the imaging means 8 captures images of the shaft member 9 using line scanning. While rotating the shaft member 9, the outer peripheral surface of the shaft member 9 is continuously imaged using line scanning, and the captured images are then developed, making it possible to inspect the entire outer peripheral surface of the shaft member 9. Furthermore, by positioning the imaging means 8 at a height that allows it to capture images of the entire longitudinal direction of the shaft member 9, the inspection time can be shortened.

[0037] Fig. 4 is a perspective view showing a second structure of a visual inspection device according to the present invention. In Fig. 4, 19a and 19b are vertical supports erected on a bottom plate 20 of the visual inspection device B, 21 is a horizontal support plate fixed to the vertical supports 19a and 19b, and 22 is a mounting plate attached to the horizontal support plate 21 via a connecting member 23. 24 is a light fixed to the mounting plate 22 and is made of a condensing light with a shade portion 24a.

[0038] Reference numerals 25a and 25b denote middle vertical supports erected on the bottom plate 20, and 26 denotes a middle horizontal support fixed between the middle vertical supports 25a and 25b. Reference numeral 27 denotes an imaging means (camera) attached to the middle horizontal support 26, and the imaging direction is downward.

[0039] A shaft member 28 (see FIG. 5) is disposed below the imaging means 27. The shaft member 28 has a hollow tubular shape. An example of such a shaft member is a shaft member that constitutes an electric linear actuator. Reference numeral 29 denotes a support means that supports the shaft member 28 from both ends in the longitudinal direction, and is composed of a pair of conical parts (not shown) that enter the hollow part from both ends of the shaft member 28 and support it.

[0040] Of the pair of conical parts (not shown), one of them is equipped with an electric cylinder 31 that moves it forward or backward along the longitudinal direction of the shaft member 28. The one of the conical parts is rotatably attached to the electric cylinder 31. The method of supporting the shaft member 28 by the support means 29 is the same as the method of supporting the shaft member 9 by the support means 10 in the visual inspection device A of the first structure shown in FIGS.

[0041] Reference numeral 32 denotes a rotating means for rotating the other conical portion (not shown) constituting the support means 29 to rotate the shaft member 28 around the axis between the other conical portion (not shown) and the other conical portion, and is constituted by a rotating motor 33. Reference numerals 34a and 34b denote arms for temporarily placing the shaft member 28 on the tip end thereof when the shaft member 28 is supported by the conical portion (not shown) of the support means 29.

[0042] The base ends of the arms 34a and 34b are attached to a bearing 36 fixed on the bottom plate 20 via a fixing member 35 and a connecting portion 36 (see FIG. 5). The method of attaching the base ends of the arms 34a and 34b to the bearing 37 via the fixing member 35 and the connecting portion 36 is the same as the method of attaching the base ends of the arms 15a and 15b to the bearing 18 via the fixing member 16 and the connecting portion 17 in the first structure appearance inspection device A shown in FIGS.

[0043] Fig. 5 is a side view showing the appearance inspection device B shown in Fig. 1 from the right side. In Fig. 5, shaft member 28 is temporarily placed on arm 34b (34a), and a pair of conical portions (not shown) is inserted into hollow portion 28a of shaft member 28, causing shaft member 28 to lift slightly from the tip end of arm 34b (34a) and release it from contact with arm 34b (34a).

[0044] In other words, the radial center position of the conical portion (not shown) is located slightly above the radial center position of the hollow portion 28a of the shaft member 28, and therefore, by inserting the conical portion into the hollow portion 28a of the shaft member 28, the shaft member 28 is lifted by the conical portion and rises slightly above the tip of the arm 34b (34a).

[0045] By releasing the contact between the shaft member 28 and the arm 34b (34a), the conical portion can be rotated by the rotating motor 33, allowing the shaft member 28 to rotate smoothly without coming into contact with the arm 34b (34a).

[0046] 5, a window portion 24b is opened in the top plate of the umbrella portion 24a of the lighting device 24, which allows the imaging means 27 to capture an image of the shaft member 28. The window portion 24b is opened over a wide range in the longitudinal direction of the lighting device 24, as shown in FIG. 4, which allows the imaging means 27 to capture an image of the entire length of the shaft member 28.

[0047] For example, multiple LED lights 38a, 38b are arranged inside the umbrella portion 24a along the longitudinal direction (the depth direction of the paper in FIG. 5). Light emitted by the LED lights 38a, 38b is reflected by the inner surface of the umbrella portion 24a and then irradiated onto the shaft member 28 as indirect light, as shown in FIG. 6. The center X of the imaging position of the imaging means 27 coincides with the position of the top axis of the shaft member 28.

[0048] FIG. 6 shows the distance H between the condensing illuminator 24 and the shaft member 28 shown in FIG. 6. As shown in FIG. 6, light emitted by the LED illuminators 38a and 38b inside the umbrella portion 24a is reflected by the inner surface of the umbrella portion 24a and irradiated onto the shaft member 28. The opposing bar illuminators 38a and 38b are positioned diagonally above the shaft member 28, and the distance H between the condensing illuminator 24 and the shaft member 28 is set to approximately 3 mm to 8 mm. A distance of approximately 5 mm is preferably set, allowing the imaging means 27 to clearly capture dents on the outer peripheral surface of the shaft member 28 using the reflected light from the LED illuminators 38a and 38b.

[0049] In the present invention, imaging of the shaft member 28 is performed by line scanning using the imaging means 27. While the shaft member 28 is rotating, the imaging means 27 continuously images the outer circumferential surface of the shaft member 28 by line scanning, and by developing the captured images, it is possible to inspect the entire outer circumferential surface of the shaft member 28. Furthermore, the imaging means 27 can be adjusted to a height position that allows it to image the entire longitudinal direction of the shaft member 28, thereby contributing to shortening the inspection time.

[0050] As described above, the appearance inspection device of the present invention can accurately inspect for scratches on the outer peripheral surface of a shaft member. In particular, the appearance inspection device A can accurately inspect for linear scratches and circumferential scratches, and the appearance inspection device B can accurately inspect for dent scratches.

[0051] Furthermore, because the inspection can be performed automatically, unlike visual inspection by workers, it does not depend on the ability of the worker and can ensure a high level of standardized inspection quality.In addition, the inspection time can be shortened, which can improve productivity.

[0052] It should be noted that by covering the visual inspection devices A and B of the present invention with a blackout curtain, it is possible to further improve the clarity of the images captured by the imaging means 8 and 27. This method makes it possible to further improve the inspection accuracy. [Industrial Applicability]

[0053] The present invention is applicable to the inspection of the outer circumferential surface of any hollow tubular shaft member. [Explanation of symbols]

[0054] 1a~1d, 19a, 19b Vertical support 2,20 Bottom plate 3a~3d horizontal support 4a, 4b, 22 Mounting plate 5a, 5b Bar lighting 5a1,5b1,5c1,5d1 Angle adjustment mechanism 6a, 6b, 25, 25b Middle vertical support 7,26 Medial lateral support 8,27 Imaging means (camera) 9,28 Shaft member 10,29 Support means 11a, 11b Conical members 12,31 Electric cylinder 13,32 Rotation means 14,33 Rotation motor 15a, 15b, 34a, 34b Arms 16,35 Fixing member 17, 23, 36 Connecting members 18,37 Bearing mechanism 21 Lateral support plate 24 Concentrated Lighting 38a,38b LED lighting A. Visual inspection device (first structure) B. Visual inspection device (second structure)

Claims

1. An external inspection device for shaft members, comprising: a support means for supporting both ends of a shaft member; a rotation means for rotating the support means; an imaging means for imaging the rotating shaft member; and an illumination means for illuminating the shaft member, wherein the imaging means is positioned so that the center of the imaging position by the imaging means is at the diagonal axis position of the shaft member.

2. The visual inspection device for shaft members as described in claim 1, characterized in that the lighting means consists of two bar lights for inspecting the presence or absence of linear scratches or circumferential scratches on the shaft member, and the two bar lights are arranged at different angular positions diagonally upward along the longitudinal direction of the shaft member.

3. An appearance inspection device for a shaft member, comprising: support means for supporting both ends of a shaft member; rotating means for rotating the support means; imaging means for imaging the rotating shaft member; and lighting means for illuminating the shaft member, wherein the imaging means is positioned so that the center of the imaging position by the imaging means is the top axis position of the shaft member, and the lighting means comprises a focusing light with an umbrella portion for inspecting the shaft member for the presence or absence of dents or scratches, wherein a light is disposed within the umbrella portion and the light from the light is reflected on the inner surface of the umbrella portion to illuminate the shaft member, and the umbrella portion is provided with a window portion which enables the imaging means to image the shaft member.

4. 4. The shaft member appearance inspection device according to claim 1, wherein the imaging means captures an image of the shaft member by line scanning.

5. An external inspection device for a shaft member as described in either claim 1 or claim 3, characterized in that the shaft member has a hollow tubular shape, the support means consists of a pair of conical portions that are inserted into the hollow portion of the shaft member and support the shaft member, and one of the pair of conical portions is equipped with an electric cylinder that moves it back and forth.

6. 4. The shaft member appearance inspection device according to claim 1, wherein said rotating means comprises a rotating electric motor for rotating said supporting means.

7. 4. The shaft member appearance inspection device according to claim 1, further comprising a blackout curtain covering said shaft member, the illumination means and the imaging means.

Images