JP6543059B2 - Article inspection method - Google Patents

Description

  The present invention relates to an apparatus for magnetically attracting and holding a minute article, and an inspection apparatus for an article using the holding apparatus.

  In recent years, the use of minute parts has increased due to the miniaturization of electronic devices and the like and the refinement of various mechanical devices. Therefore, an apparatus for holding these minute parts is used in various processes such as manufacturing, inspection, and shipping.

  As an example of such a device, a device for vacuum-adhering and holding an article on a nozzle is known. However, the device by vacuum suction can not be used when the suction surface of the article has irregularities such as grooves or ridges, or there is a hole penetrating the article, and can be used in the form of an article that can be held. There is a limit.

  On the other hand, Patent Documents 1 to 3 describe devices for magnetically attracting and holding articles. The device by magnetic adsorption can hold articles of relatively various shapes although the material of the articles to be targeted is limited. Also, with the development of high performance magnets, the types of materials that can be adsorbed are increasing.

JP 2008-188747 A Unexamined-Japanese-Patent No. 2006-150529 Unexamined-Japanese-Patent No. 6-099387

  A desirable feature of a micro article holding device is that it can hold articles of various shapes reliably in addition to the small size of the holding device itself. Furthermore, since the minute articles are easily moved by the change of the magnetic field, the holding device can prevent the adsorption position of the articles held during transport from shifting or changing the direction, and release the articles to the correct position. Is desired.

  However, none of the devices described in Patent Documents 1 to 3 have means for preventing displacement of the articles when adsorbing, moving and releasing the articles. In these devices, the article may move during adsorption to shift the adsorption position, the adsorption position of the article may shift while holding and transporting the article, or the article may move when the article is released.

  The present invention has been made in consideration of the above, and an object thereof is to provide a holding device suitable for holding a minute article. More specifically, it is an object of the present invention to provide a holding device provided with means for positioning an article when adsorbing, moving and releasing a minute article. Another object of the present invention is to provide a method of inspecting an article using such a holding device.

  The article holding device according to the present invention is fixed directly or indirectly to a sleeve made of nonmagnetic material, a linear actuator in which a movable rod linearly moving in the axial direction of the sleeve is inserted in the sleeve, and the movable rod directly or indirectly And a magnet unit housed in the sleeve. The magnet unit is configured by a combination of a plurality of magnetic members including one permanent magnet or at least one permanent magnet, the front end face is a first magnetic pole, and the rear end face is a second magnetic pole. .

  Here, the front means the direction in which the article to be held is seen from the holding device, and the rear means the opposite direction. Further, forward movement of the magnet unit or the movable rod is referred to as forward movement, and backward movement is referred to as backward movement. The magnetic member is a member made of a magnetic material, and the magnetic material is a concept including a permanent magnet and a soft magnetic material. The first pole is an N pole or an S pole, and the second pole is an S pole or an N pole opposite to the first pole.

  Preferably, of the members constituting the magnet unit, the most front member is an annular or cylindrical shape in which a hole penetrating in the axial direction of the sleeve is formed. Alternatively, preferably, at least a central portion of a front end surface of the magnet unit is a spherical surface that is convex forward.

  In addition, preferably, of the members constituting the magnet unit, the member located on the frontmost side is a permanent magnet. At this time, more preferably, the magnet unit is composed of two or more magnetic members, and the permanent magnet is magnetically attracted to and coupled to a magnetic member adjacent to the rear.

  In addition, preferably, the permanent magnet is an Nd-Fe-B based magnet. Preferably, the magnetic flux density at the front end face of the magnet unit is 300 mT or more.

  Also preferably, the linear actuator is an air cylinder.

  An article inspection apparatus according to the present invention includes: the article holding apparatus according to any one of the above; and an articulated robot arm having the article holding apparatus fixed at its tip and moving an article held by the article holding apparatus to a predetermined position in a predetermined posture. An illumination for projecting light to the article at the predetermined position; and a camera for imaging the article projected to the illumination.

  Preferably, the illumination is low angle illumination.

  According to the article holding device of the present invention, when a minute article is adsorbed, moved, or released, the position or the orientation of the article does not easily change, and accurate positioning can be performed. Further, according to the article inspection method of the present invention, the appearance of the article can be observed and inspected from a plurality of directions.

It is a figure showing the structure of the article holding device of a 1st embodiment. It is a figure which shows the modification of a structure of a magnet unit. It is a figure which shows the modification of a sleeve shape. It is a figure for demonstrating the positioning mechanism of the articles | goods in which the through-hole was formed. It is a figure which shows operation | movement of the articles | goods holding | maintenance apparatus of 1st Embodiment. It is a figure showing the structure of the article holding device of a 2nd embodiment. It is a figure which shows operation | movement of the articles | goods holding | maintenance apparatus of 2nd Embodiment. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole structure of one Embodiment of a goods inspection apparatus. It is a figure which shows the structure of the imaging part of one Embodiment of a goods inspection apparatus. It is a figure which shows the relationship between the outline of an article, and the size of a sleeve.

  A first embodiment of the article holding device of the present invention will be described based on FIGS. In the drawings, in order to facilitate understanding of the structure, some members are shown as appropriate in cross section.

  In FIG. 1, the article holding device 11 of the present embodiment has a sleeve 30, an air cylinder 35, and a magnet unit 41. The sleeve has an opening 32 at the front (lower side in FIG. 1) end. In the air cylinder, the main body 36 is fixed to the sleeve via the flange 38, and the movable rod 37 is accommodated in the sleeve. The magnet unit is fixed to the tip of the movable rod of the air cylinder. When the air cylinder is extended, the magnet unit can be advanced to adsorb the article at the opening.

  The sleeve 30 is made of nonmagnetic material. Plastic, copper, aluminum or the like can be used as the nonmagnetic material. Among them, it is preferable to use a plastic. This is because when the open end 31 of the sleeve abuts on the article, the article is not easily damaged.

  In addition, the sleeve opening end 31 may be provided with a non-slip portion in order to suppress displacement of the article. The non-slip portion can be formed, for example, by sticking an elastic sheet made of rubber or resin having a thickness of about 0.1 mm to 0.3 mm on the opening end 31.

  The shape of the sleeve 30 is not particularly limited, but is preferably cylindrical. This is because, when used for the inspection of an article to be described later, regardless of the direction of the adsorbed article, it is difficult to protrude from the contour of the article, and it is difficult to interfere with the illumination.

  In the air cylinder 35, the main body 36 is fixed to the sleeve 30 via the flange 38. As a method of fixing an air cylinder to a flange and a method of fixing a sleeve, known methods such as screwing can be used. Also, the air cylinder body may be fixed directly to the sleeve without using a flange. Since the main body 36 is fixed to the sleeve, when the air cylinder is expanded and contracted, the movable rod 37 accommodated in the sleeve can linearly move in the axial direction relative to the sleeve.

  The air cylinder 35 is a type of linear actuator. A linear actuator is a device that converts various energy into linear motion. As the linear actuator, in addition to the air cylinder, one using a hydraulic cylinder, an electric cylinder, a linear motor, or one that converts rotational motion of the motor into linear motion by a motion conversion mechanism can be used. Among them, it is preferable to use an air cylinder because miniaturization is possible and accurate control is easy.

  The magnet unit 41 is fixed to the tip of the movable rod 37. Thereby, when the air cylinder 35 expands and contracts, the magnet unit is guided to the inner surface of the sleeve 30 and linearly moved in the axial direction of the sleeve in accordance with the linear motion of the movable rod.

  The magnet unit 41 is configured by a combination of a plurality of magnetic members including one permanent magnet or at least one permanent magnet. The front end surface 47 of the magnet unit is a first magnetic pole (e.g., N pole), and the opposite rear end surface 48 is a second magnetic pole (e.g., S pole). By forming the magnetic pole facing the opening 32 in this manner, the magnetic flux density emanating from the front end face of the magnet unit is increased, and a strong attractive force can be obtained.

  The magnet unit 41 consists of two members in this embodiment. The front member is a permanent magnet 51. The rear magnetic member 61 may be a permanent magnet or a soft magnetic member made of a soft magnetic material. As the soft magnetic material, various known materials such as iron having high magnetic permeability can be used. Preferably, the foremost member of the magnet unit is a permanent magnet. This is because a stronger adsorption power can be obtained.

  The configuration of the magnet unit is not limited to that shown in FIG. For example, as shown in FIG. 2A, the magnet unit 42 may consist of a single permanent magnet 52. Also, for example, as shown in FIG. 2B, the magnet unit 43 may dispose the soft magnetic member 63 in the front and the permanent magnet 53 in the rear.

  It is preferable to use a permanent magnet having a strong magnetic force. This is because an article made of more various materials can be adsorbed. The permanent magnet is preferably a Nd-Fe-B based magnet (neodymium magnet). Alternatively, regardless of the type of permanent magnet, the magnetic flux density at the front end face 47 of the magnet unit 40 is preferably 300 mT or more, more preferably 400 mT or more, and particularly preferably 500 mT or more. This makes it possible to adsorb an article made of austenitic stainless steel that is not adsorbed by general magnets, or an article made of many alloys including iron, cobalt, nickel, chromium, manganese and the like as components. In addition, by holding strongly with strong magnetic force, it is possible to convey a minute article at high speed. In addition, it is preferable that the magnetic flux density of a permanent magnet is 700 mT or less from the point of the availability.

  The method of fixing the magnet unit 41 to the tip of the movable rod 37 of the air cylinder is not particularly limited, and a method of bonding using an adhesive, a mechanical method using a screw or the like, or the like can be used.

  The method of joining the members constituting the magnet unit 41 is not particularly limited. In FIG. 1, the permanent magnet 51 located on the front side is attracted and coupled to the magnetic member 61 located on the rear side by magnetic force. In order to adopt this structure, the attraction between the permanent magnet and the magnetic member needs to be much larger than the attraction between the magnet unit and the article. For example, if the permanent magnet is a Ne--Fe--B magnet and the article does not reach a general magnet, this structure can be adopted because the attraction between the permanent magnet and the magnetic member is extremely large. By this structure, the permanent magnet 51 can be replaced very easily.

  The size of the permanent magnet 51 is preferably large in that a strong magnetic force can be obtained. On the other hand, in the holding device according to this embodiment for minute articles, the holding device itself is desirably small, and the outer diameter in a cross section perpendicular to the axis of the sleeve is preferably 40 mm or less, more preferably It is 20 mm or less. In practice, depending on the type of the article and the content of handling, the type, size, etc. of the magnet for obtaining the required adsorption force will be determined, and the sleeve will be selected according to the outer shape of the magnet. FIG. 3 shows an example of a holding device 14 employing a magnet unit 44 consisting of a permanent magnet 54 of a smaller diameter and a magnetic member 64 and a sleeve 34 of a smaller diameter. The length in the sleeve axial direction of the permanent magnet is not particularly limited. The longer the magnet, the stronger the magnetic force, so one with an appropriate length can be selected as needed.

  In the present embodiment, the permanent magnet 51 is annular. When a hole is present on the suction surface of the article, this shape acts as a magnetic positioning means for the article if the foremost member of the magnet unit is annular or tubular. It will be described below.

  When the article is attracted to the magnet, a force acts to change the position or the direction of the article so that magnetic lines of force from the magnet pass through the article as much as possible. Many small parts have holes formed for fixation. Then, the tendency to change the position or the direction at the time of adsorption becomes particularly remarkable when the hole penetrating the article is formed on the adsorption surface of the article.

  The top view of the articles | goods 91 in which the hole 97 was formed in FIG. 4A is shown. When such an article is adsorbed by a magnet without holes, for example, a cylindrical magnet 50, the article moves at the moment of adsorption, and the position is likely to shift or change direction (change from FIG. 4B to FIG. 4C) . In addition, even if it is once adsorbed, the article is easy to move during transport, and the article is easy to move even at the moment of releasing the article. This phenomenon can also occur when using an annular or tubular magnet 51 having a hole 57 (change from FIG. 4D to FIG. 4E). However, with the magnet's hole 57 concentric with the article's hole 97, and with the magnet being brought close to perpendicular to the suction surface, once it is attracted, the position and orientation of the article is stabilized (FIG. 4F). In the holding device according to the present embodiment, the magnet unit 41 can be brought close to and adsorbed while the article is held by the sleeve so that the hole of the permanent magnet 51 and the hole of the article are concentric. The goods are hard to move. In order to suppress the displacement of articles due to high-speed conveyance, it is preferable to provide a non-slip portion at the sleeve open end 31 as described above.

  Next, the operation of the holding device of the present embodiment will be described based on FIG.

  The tip portion of the holding device 11 and an article 91 are shown in FIG. The article 91 is in the form of a piece, and a hole 97 penetrating the article is formed substantially at the center.

  In FIG. 5A, the holding device 11 is made to face the suction surface 95 of the article so that the hole 57 of the permanent magnet 51 and the hole 97 of the article 91 are concentric. At this time, the magnet unit is in the retracted position in the sleeve.

  Then, in FIG. 5B, the holding device is brought close to the article, and the open end 31 of the sleeve is brought into contact with the suction surface 95 of the article. When the holding device is operated by a robot arm or the like, accurate operation can be performed by adjusting the posture and position of the holding device while confirming the position of an article with a camera that is an eye of the robot.

  Next, in FIG. 5C, the air cylinder is extended, and the movable rod 37 and the magnet unit 41 are advanced to be attracted to the article 91. At this time, since the magnet unit is brought close while holding the article at the open end of the sleeve, the article does not move at the moment of adsorption. In addition, since the article is held not on the point but on the entire circumference of the opening end, the article does not rotate at the moment of adsorption. When the magnetic force is strong, a sufficient adsorptive force can be obtained at a position where the front end surface 47 of the magnet unit is slightly recessed from the open end 31 of the sleeve. In that case, the front end face of the magnet unit may stop immediately before contacting the article 91. Such control is also possible because accurate position feed can be performed by the air cylinder.

  Then, in FIG. 5D, the holding device can be moved while holding the article. Also at this time, it is preferable to keep the sleeve open end 31 in contact with the article. When moving a holding | maintenance apparatus using a robot arm etc., big force may act on articles. By keeping the open end of the sleeve in contact with the article, it is possible to prevent displacement of the article during conveyance and change in orientation (rotation in a plane perpendicular to the axis). In particular, in the case where a holding device is used in an inspection device or the like to be described later, high-speed transport as much as possible is required in order to reduce the tact time. Therefore, the moving speed of the actual robot arm may reach 2500 mm / sec, and the acceleration may reach 2.5 G. Even in such a case, stable handling of the article is possible by using the holding device of the present embodiment.

  The operation of the holding device 11 releasing the article is opposite to the above-mentioned suction operation. First, place the article in the required position (FIG. 5C). Next, the magnet unit is retracted while the sleeve open end is in contact with the article (FIG. 5B). At this time, since the magnet unit is retracted while holding the article at the open end of the sleeve, the article hardly moves at the moment when the magnet unit is released. Then, after fully retracting the magnet unit, the holding device is released from the article to release the article (FIG. 5A).

  The effects of the present embodiment will be described again.

  According to the holding device of the present embodiment, since the sleeve is brought into contact with the article and the magnet is adsorbed while holding the article, the article does not easily move or shift in position or change its direction during adsorption. At this time, since the article is held by the open end of the circular sleeve, the article is more difficult to rotate than in the case of holding at one point with a pin or the like. By keeping the open end of the sleeve in contact with the article even after the article is adsorbed to the magnet unit, the article is not easily displaced or rotated during transport. When releasing the article, since the magnet is released while holding the article with the sleeve, it is difficult for the article to move at the moment of detachment. As a result, the article can be released to the correct position. Thus, the sleeve of this embodiment functions as an article positioning means.

  Furthermore, in the present embodiment, since the annular permanent magnet 51 is disposed on the front end surface of the magnet unit, the positioning effect can be obtained for the article in which the hole is formed. That is, since the magnet is adsorbed while holding the article by the sleeve, the article does not move at the moment of adsorption, and the hole of the permanent magnet 51 and the hole of the article can be concentric to attract the magnet unit. Then, when the two holes are concentric and the suction is completed, it is less likely that the position of the article will shift or the direction will change during transport. Even when the article is released, the article does not move easily. Thus, the shape of the annular permanent magnet 51 functions as a means for positioning an article.

  Next, a second embodiment of the article holding device of the present invention will be described based on FIG. 6 and FIG.

  In FIG. 6, the article holding device 15 of the present embodiment differs from the first embodiment in that the permanent magnet 55 is spherical.

  As described above, when the central portion of the front end surface 47 of the magnet unit 45 is a spherical surface convex toward the front, when an article having a hole or an adsorption surface 95 adsorbs an article or the like having a curved surface, positioning is physically performed. it can. The shape of the permanent magnet 55 is not limited to a spherical shape, and may be, for example, a hemispherical shape.

  Also in the present embodiment, the front end face 47 of the magnet unit 45 is the first magnetic pole (for example, the N pole). When the spherical permanent magnet 55 is coupled to the magnetic member 65 adjacent to the rear only by the magnetic force, by using a rod-like permanent magnet as the magnetic member, the direction of the permanent magnet 55 is correct so that the first magnetic pole comes to the front end face correctly. Can be combined. In addition, the magnetic force of the bar magnet in that case may be weak.

  The operation of the present embodiment will be described based on FIG.

  The tip portion of the holding device 15 and the article 91 are shown in FIG. The article 91 is in the form of a piece, and a hole 97 penetrating the article is formed substantially at the center.

  In FIG. 7A, the holding device 15 is faced to the suction surface 95 of the article so that the center of the ball of the permanent magnet 55 is in front of the hole 97 of the article 91. Next, the holding device is brought close to the article, and the sleeve open end 31 is brought into contact with the suction surface of the article (FIG. 7B). Then, while holding the article at the open end of the sleeve, the air cylinder is extended and the magnet unit 45 is advanced to be attracted to the article (FIG. 7C). At this time, the article adheres to the magnet with the front end surface 47 of the magnet unit slightly inserted into the hole of the article, and therefore, unlike the first embodiment (FIG. 5C), the tip of the permanent magnet 55 is from the opening of the sleeve A little out.

  Next, in FIG. 7D, the article is moved while being held. Also at this time, it is preferable to keep the sleeve open end 31 in contact with the article.

  The operation of the holding device 15 releasing the article is opposite to the above-mentioned suction operation.

  Next, an embodiment of the article inspection apparatus of the present invention will be described based on FIGS. 8 and 9.

  For precision parts and the like, the appearance inspection of parts is increasingly required. In order to inspect and inspect the appearance of a wide variety of articles from multiple directions, there is a method of holding the articles in some way and imaging with a camera while changing the posture of the articles by the articulated robot arm. The holding device used for such an inspection method should be compact so as not to disturb the illumination at the time of inspection, and the position and posture of the held article should be large even if the article is subjected to great acceleration and deceleration. It is required not to shift. The article holding device of the present invention is suitable for use in such an inspection method.

  In FIG. 8, the article inspection apparatus 70 of the present embodiment has an article holding device 16, an articulated robot arm 71, a low angle ring illumination 72, and a camera 73.

  The holding device 16 is the article holding device of the present invention. Preferably, the article holding device described in the first or second embodiment can be used. The holding device is fixed to the tip of the articulated robot arm 71.

  The articulated robot arm can perform complicated movements similar to a human arm by having many rotation axes. The robot arm 71 moves the article 92 sucked and held by the tip of the holding device 16 to a predetermined position immediately before the low angle ring illumination 72 in a predetermined posture.

  In FIG. 9, the low angle ring illumination 72 is a ring-shaped low angle illumination. Low-angle illumination projects light L from a low angle onto the surface of the article 92 to be inspected. By this, the flaw etc. of the article surface are easy to be conspicuous, and the discovery of a fault becomes easy. Here, the low angle means that the angle from the inspection surface is small, and the angle of incidence θi to the inspection surface, that is, the angle from the perpendicular made to the surface of the article is large. The incident angle θi is preferably 45 degrees or more, more preferably 60 degrees or more, and particularly preferably 75 degrees or more. In order to evenly illuminate the surface of the article 92 with low angle illumination, it is necessary to make the distance between the illumination and the work sufficiently short. The distance between the low angle illumination 72 and the article 92 is preferably 15 mm or less.

  The camera 73 images the surface of the article 92 projected to the low angle ring illumination 72 through the hole of the low angle ring illumination. The obtained image is processed by an image processing apparatus (not shown) to determine the presence or absence of defects such as scratches and chips.

  Next, the operation of the article inspection method of the present embodiment will be described.

  First, the article 92 to be inspected is adsorbed by the holding device 16 and taken up from the pallet or the like.

  Next, the article 92 is moved by the articulated robot arm 71 to a predetermined position immediately before the low angle ring illumination 72 in a predetermined posture. The posture of the article is, for example, oriented so that the surface opposite to the suction surface is perpendicular to the low angle ring illumination and the optical axis of the camera 73. At this time, since the orientation of the held article (rotational direction in a plane perpendicular to the sleeve axis of the holding device) is not constant, the camera captures an image of the article, and image processing determines the orientation of the article. At the same time, an appearance inspection of the imaged surface is performed.

  In image processing, the direction of the article is determined by extracting the edge of the article from the captured image. At this time, if the sleeve of the holding device protrudes from the contour of the article, it is reflected in the image, which is not preferable because the image processing becomes complicated. Thus, the outer diameter of the sleeve of the holding device is preferably tapered so as to be completely within the contour of the article. In FIG. 10, when the cross section of the sleeve 30 is circular, the diameter is preferably smaller than the largest inscribed circle 96 of the contour P of the article 92. In order to be available for many types of articles, the diameter of the sleeve of the holding device is preferably 50 mm or less, more preferably 30 mm or less, particularly preferably 20 mm or less.

  Once the article's orientation is determined, taking into account the results, the article's attitude is changed so that the other side to be examined faces the low angle ring illumination and the camera. FIG. 9 shows this state. At this time, if the sleeve protrudes from the contour of the article, it is not preferable because a shadow of illumination is formed on the side to be inspected. Also from this point of view, it is preferable that the diameter of the sleeve of the holding device be thin so as to completely enter the contour of the article. Further, in FIG. 9, the length of the sleeve 30 is preferably longer than the radius of the low angle ring illumination 72. Considering that the radius of general low angle ring illumination is about 50 to 100 mm, the length of the sleeve is preferably 50 mm or more, more preferably 75 mm or more, and particularly preferably 100 mm or more.

  Subsequently, the attitude of the article can be changed to inspect the other side. In order to inspect the suction surface of the article, the article may be placed on a table, inverted, and picked up again by the holding device.

  When all inspections are completed, the articulated robot arm loads the articles on a pallet or the like.

  If the article holding device of the present invention is used, the position of the article is unlikely to shift or change its direction in the middle of the inspection process even if movement and rotation by the robot arm are repeated. In addition, when the holding device according to the first or second embodiment is used, the position of the article is unlikely to shift or change its direction even when the hole is formed in the article. Also, when loading the goods onto the pallet after the inspection, the goods can be released to the correct position.

  The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the technical idea thereof.

  The article holding device of the present invention can be used not only for visual inspection of articles but also in various scenes such as taking out from a pallet, stacking on a pallet, moving from one process to another process, and the like.

  Moreover, the holding | maintenance apparatus and test | inspection apparatus of this invention can be used with respect to various articles | goods, if it adsorb | sucks to a magnet. Examples of such articles include micro magnets, bolts, nuts, cemented carbide tips, tablets, cam parts, connector pins and the like.

11, 14-16 Article holding device 30, 34 Sleeve 31 Sleeve open end 32 Sleeve opening 35 Air cylinder (linear actuator)
36 Air cylinder main body 37 Movable rod of air cylinder 38 Flange 41-45 Magnet unit 47 Front end face of magnet unit 48 Rear end face of magnet unit 50-55 Permanent magnet 57 Hole of permanent magnet 61, 63-65 Magnetic member 70 Inspection device 71 Articulated robot arm 72 low angle ring lighting L light θi angle of incidence 73 camera 91, 92 article 95 suction surface of article P outline of article 96 maximum inscribed circle of outline of article 97 hole of article

Claims (1)

A method of inspecting an article in which a through hole is formed using an article holding device, comprising:
The article holding device is
A sleeve made of nonmagnetic material,
A linear actuator in which a movable rod linearly moving in the axial direction of the sleeve is inserted in the sleeve;
A magnet unit fixed directly or indirectly to the tip of the movable rod and housed in the sleeve;
The magnet unit is
Comprising a combination of magnetic members including one permanent magnet or at least one permanent magnet,
The front end face is a first magnetic pole, and the rear end face is a second magnetic pole,
Among the members constituting the magnet unit, the most forward member is an annular or cylindrical shape in which a hole penetrating in the axial direction of the sleeve is formed,
The article holding device operates the articulated robot arm fixed to the tip so that the hole of the most forward member of the members constituting the magnet unit and the hole of the article are concentric. Aligning the device with the suction side of the article and bringing the open end of the sleeve into contact with the suction side of the article;
Advancing the movable rod while holding the article at the open end so that the magnet unit is adsorbed to the article;
Operating the articulated robot arm to move the article held by the article holding device to a predetermined position in front of a camera in a predetermined posture;
Projecting light from the illumination to the article at the predetermined position;
Imaging the article illuminated by the illumination with the camera;
An article inspection method having:

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