JP2017190962A - Work appearance inspection device and appearance inspection method - Google Patents

Abstract

An object of the present invention is to provide a workpiece visual inspection apparatus and a visual inspection method capable of performing visual inspection of both the front and back surfaces in a short time. A first inspection/conveyance unit (1) includes a moving mechanism unit that moves a front side transfer table (10) from a supply position of a work (W) to a reversing unit (3) via a front side photographing unit (2); It has a holder 17 which is fixed in place on the top. The front-side photographing unit 2 includes a plurality of sets of laser irradiation devices and cameras arranged across the movement path of the work W. As shown in FIG. The reversing unit 3 has a rotating mechanism for reversing the work W by 180 degrees around the movement direction thereof. [Selection drawing] Fig. 1

Description

  The present invention relates to an apparatus for inspecting the appearance of a workpiece such as various machine parts or electronic parts, and an appearance inspection method.

  2. Description of the Related Art Conventionally, an inspection device that inspects the appearance of a workpiece by irradiating a workpiece moving by a conveying device such as a conveyor with laser light and photographing the reflected light with a camera is known.

  The appearance of the workpiece that the conventional inspection device moves is photographed by a plurality of cameras, and the overall shape of the workpiece is grasped by synthesizing these images and stored in advance. By comparing with the reference shape, it is determined whether or not the workpiece is defective.

  For example, in the inventions described in Patent Documents 1 to 3, the entire shape of the workpiece supplied on the belt conveyor is photographed and compared with a reference shape. However, in a transport device such as a belt conveyor where positioning of the workpiece is impossible, the captured image differs depending on the workpiece to be inspected. Therefore, the image data of the entire workpiece obtained from the camera is used as the reference shape image data. It is necessary to perform coordinate transformation so that it can be compared. In addition, if the shape of the entire workpiece is not created by combining video data from a plurality of cameras, it cannot be compared with the reference shape, so that it takes time to combine the video data.

  Furthermore, when inspecting the shape of the entire periphery of the workpiece, it is necessary to invert the workpiece during the conveyance. However, in a device that cannot accurately position a workpiece such as a belt conveyor, it is necessary to move the reversing device in accordance with the position of the work, so that the configuration of the reversing device becomes complicated or the reversing operation takes time.

JP 2005-148010 A JP-A-10-197231 JP-A-6-26843

  In order to solve such a problem, it is conceivable to inspect the workpiece while photographing it while being supported by a holder provided at a fixed position of the transport device. However, in such a conventional technique, accurate image data cannot be obtained because the holder interferes with photographing. In addition, the work must be reversed by avoiding the holder, the structure of the reversing device becomes complicated, and the reversing work takes time. In particular, when one side of the workpiece is a member longer than the other side, the length of the workpiece becomes an obstacle, and it is difficult to quickly reverse the workpiece in a narrow space in the apparatus.

  In particular, since the conventional technique performs imaging of front and back image data and work reversal work while moving the workpiece by one transport device, the inspection of the next workpiece can be performed if the inspection of one workpiece is not completed. Can not. As a result, the prior art has a problem that it takes a long time to inspect the appearance of the workpiece.

  The present invention has been proposed to solve the above-described problems of the prior art. The objective of this invention is providing the external appearance inspection apparatus and external appearance inspection method of the workpiece | work which can implement the external appearance inspection of both front and back in a short time.

The present invention has the following configuration in a work appearance inspection apparatus that conveys a work in a straight line, images the appearance of the work with a camera, and inspects the appearance of the work.
(1) a first inspection transport unit arranged along the moving direction of the workpiece that moves linearly, a front side imaging unit that images the front side of the workpiece, and a reversing unit that inverts the workpiece. A back side imaging unit that images the back side of the workpiece and a second inspection transport unit are provided.
(2) The first inspection transport unit includes a front-side transport table, a moving mechanism unit that moves the front-side transport table from the workpiece supply position to the reversing unit via the front-side imaging unit, and the work Is provided at a predetermined position on the front-side transport table.
(3) The front-side imaging unit includes a plurality of sets of laser irradiations arranged on the one side and the other side in the movement direction on the left and right sides of the movement path above the workpiece movement path fixed to the holder, respectively. A device and a camera are provided.
(4) The reversing unit includes a push-up member that moves up and down from the bottom of the holder, a lift mechanism for the push-up member, a gripping mechanism that supports the workpiece pushed up by the push-up member, and the gripping mechanism. And a rotation mechanism for reversing 180 °.
(5) The back side imaging unit includes a plurality of sets of laser irradiations arranged on the one side and the other side in the moving direction on the left and right sides of the moving path above the moving path of the work fixed to the holder. A device and a camera are provided.
(6) The second inspection transport unit includes a back side transport table, a moving mechanism unit that moves the back side transport table from the reversing unit to the discharge position of the work through the back side photographing unit, and the work Is provided at a predetermined position on the back side transfer table.
(7) The front side photographing unit and the back side imaging unit each include a quality determination processing unit that determines the quality of the appearance of the work using the video information captured by each camera.

The appearance inspection apparatus of the present invention may have the following configuration.
(1) The rotating mechanism inverts the gripping mechanism by 180 ° around the moving direction of the workpiece.
(2) The laser irradiation device and the camera arranged on the one side and the other side in the moving direction on the left and right sides of the moving path are provided on a rectangular diagonal line having an intersection on the moving path of the workpiece.
(3) The workpiece is a long member extending along the moving direction, and the fixed laser irradiation device and the camera are arranged on the front and upper surfaces and side surfaces or the upper surface, side surfaces and rear surface of the long member. It is arranged at an angle at which at least two surfaces are photographed simultaneously.
(4) The holders provided on the front-side transfer table and the back-side transfer table hold one end side and the other end side of the work, and the push-up member pushes up the center of the work and lifts the work from above the holder The gripping mechanism holds the one end side and the other end side of the work lifted by the push-up member and reverses the work.
(5) The reversing unit includes a first support unit and a second support unit that change in distance from each other, and the first support unit is provided with a driving-side grip unit that is rotated 180 ° by a driving source. The second supporting portion is provided with a driven gripping portion that freely rotates, and in a state where the workpiece is held by the driving gripping portion and the driven gripping portion, as the driving gripping portion rotates. And the gripping part on the driven side rotate.
(6) The quality determination processing unit is provided in each of the front side imaging unit and the back side imaging unit.

The work visual inspection method of the present invention has the following configuration.
(1) A work appearance inspection method using the appearance inspection apparatus according to any one of claims 1 to 7.
(2) The front-side transport table and the back-side transport table are alternately stopped at the position of the reversing unit.
(3) The first inspection transport unit and the second inspection transport unit capture, move, supply or discharge, lift, or receive a workpiece transported by the first inspection transport unit and the second inspection transport unit, respectively. This is performed in parallel in a state in which the workpieces conveyed by the two inspection conveyance units do not interfere with each other.

  ADVANTAGE OF THE INVENTION According to this invention, the external appearance inspection apparatus and external appearance inspection method of the workpiece | work which can implement the external appearance inspection of both front and back in a short time can be provided.

FIG. 1 is a perspective view of an appearance inspection apparatus according to an embodiment as viewed from the front side. FIG. 2 is a perspective view of the appearance inspection apparatus according to the embodiment as viewed from the back side. FIG. 3 is a perspective view of the front transport table as viewed from the front side. FIG. 4 is a perspective view of the front transport table as viewed from the back side. FIG. 5 is a perspective view of the front side photographing unit viewed from the front side. FIG. 6 is a perspective view of the laser irradiation device and the camera fixed to the arm as seen from below. FIG. 7 is a side view of the front side photographing unit, the reversing unit, and the back side photographing unit. FIG. 8 is a plan view of the front side photographing unit, the reversing unit, and the front side photographing unit. FIG. 9 is a perspective view of the gripping mechanism of the reversing unit as viewed from the back side. FIG. 10 is a perspective view of the drive-side gripping unit as seen from the front side. FIG. 11 is a perspective view of the reversing unit as viewed from the front side, and shows a state where the push-up plate is in the standby position. FIG. 12 is a perspective view of the reversing unit viewed from the front side, and shows a state where the push-up plate is in the raised position. FIG. 13 is a perspective view of the discharge device as viewed from the back side. FIG. 14 is an enlarged perspective view of a grip portion of the discharge device. FIG. 15 is a plan view of the discharge device. FIG. 16 is a side view of the discharge device. FIG. 17 is a block diagram illustrating the camera and the image data processing unit.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, only the base and the support that support each part are displayed, and the entire frame that supports the base and the support is not shown. The workpiece supply side is called the front side of the apparatus, and the workpiece discharge side is called the back side of the apparatus. The right side or the left side means the right side or the left side when viewed from the front side of the apparatus unless otherwise specified.

  The workpiece to be inspected is a connecting rod that connects an engine piston and a crankshaft. The connecting rod is a small end that connects to the piston (one end of the workpiece in this embodiment), a big end that connects to the crankshaft (the other end of the workpiece in this embodiment), and a rod that connects the two. Part. In the present embodiment, the appearance inspection is performed by moving the rod portion from the near side to the far side in a state where the rod portion is arranged in parallel to the moving direction of the workpiece so that the big end faces the back side of the inspection apparatus.

[1. Configuration of Embodiment]
(1) Overall configuration: FIGS. 1 and 2
The appearance inspection apparatus according to the present embodiment includes a first inspection transport unit 1, a front-side imaging unit 2, a reversing unit 3, a back-side imaging unit 4, and a second that are arranged along the moving direction of the workpiece W that moves linearly. The inspection transport unit 5 and the discharge device 6 are provided. The first inspection transport unit 1 inspects the front side of the workpiece W, and the second inspection transport unit 5 inspects the back side of the workpiece W. Therefore, the first inspection transport unit 1 includes a front-side transport table 10, and the second inspection transport unit 5 includes a back-side transport table 50.

(2) 1st inspection conveyance part 1 ... FIG. 3, FIG.
On a frame (not shown), a plate-like base 11 extending along the conveyance direction of the workpiece W is provided. The base 11 reaches from the supply position of the workpiece W to the discharge position. Two rails 12 are provided on the upper surface of the base 11 along edges on both sides of the base 11. The front conveyance table 10 and the back conveyance table 50 are supported by the two rails 12 and move.

  The drive shaft 13 is extended from the supply position of the workpiece W to a position beyond the reversing unit 3 on the back side. A motor 14 for rotating the drive shaft 13 is connected to the front end of the drive shaft 13. A male screw is formed on the outer peripheral surface of the drive shaft 13 and is inserted into a female screw portion 15 provided on the lower surface of the front-side transport table 10. The drive shaft 13 is rotated in both forward and reverse directions by the motor 14. As the drive shaft 13 rotates forward or backward, the front-side transport table 10 reciprocates.

  The front conveyance table 10 is a quadrangular member having two sides parallel to the conveyance direction of the workpiece W. A slider 16 is provided on the lower surface of the front conveyance table 10 in accordance with the positions of the two rails 12. The slider 16 is supported by the two rails 12, and when the slider 16 slides on the rails 12, the front-side transport table 10 moves from the workpiece W supply position to the reverse position.

  A holder 17 is provided on the upper surface of the transfer table. The holder 17 has a table 17a fixed to the right surface of the front-side transport table 10, a front support 17b and a back support 17c fixed on the table 17a. The support portion 17b on the near side is provided with a positioning recess 17d that is recessed in a semicircular shape toward the near side. One end side of the workpiece W is fitted into the positioning recess 17d. The rear support portion 17c is provided with a substantially circular positioning projection 17e that fits inside the big end (the other end side of the workpiece) of the connecting rod that is the workpiece W.

  The back side transfer table 50 has the same configuration as the front side transfer table 10, and reciprocates from the reverse position to the discharge position of the workpiece W while being supported by the two rails 12. Therefore, the drive shaft 13 of the back side transfer table 50 is extended to the supply position side of the workpiece W from the reversing unit 3. The drive shaft 13 of the back side transfer table 50 is rotated in both forward and reverse directions by a motor 14 provided on the back side. With the forward or reverse rotation of the drive shaft 13, the back side conveyance table 50 reciprocates between the reversing unit 3 and the discharge device 6.

(3) Front side photographing unit 2...
The front-side imaging unit 2 includes a column 21 indicated by a frame (not shown). The support column 21 is fixed to the right side of the base 11 while avoiding the movement path of the workpiece W. A bracket 22 that extends horizontally toward the movement path of the workpiece W is provided on the upper end of the column 21. Four arms 23 are provided on the lower surface of the bracket 22. The four arms 23 are provided on a rectangular diagonal centered at the intersection of the central axis of the moving workpiece W and the central axis of the bracket 22 in the left-right direction when viewed from the plane. The upper portions of the four arms 23 are fixed to the bracket 22 and extend obliquely downward from the intersection of the diagonal lines.

  The laser irradiation device 24 and the camera 25 are fixed to the lower surfaces of the arms, that is, the surfaces facing each other while being inclined toward the conveyance direction of the workpiece W. The laser irradiation device 24 irradiates a moving workpiece W with a laser beam having a narrow width of a predetermined length obliquely from above. The width of the laser beam to be irradiated is a dimension that sufficiently covers the left and right widths of the workpiece W supported by the holder 17 and the height of the workpiece W protruding on the holder 17. The camera 25 is provided below the laser irradiation device 24, images the reflected light of a narrow laser beam irradiated to the workpiece W, and detects the external shape of the photographed workpiece W from the bent shape of the captured reflected light. To do.

  Each of the cameras 25 is connected to a quality determination processing unit that determines the quality of the appearance of the workpiece W using video information captured by each camera 25. As shown in FIG. 17, the pass / fail judgment processing unit includes a calculation unit 26 that detects the external shape of the workpiece W from the photographing data, and a storage unit that stores the normal external shape of the workpiece W stored at each camera position. 27 and a determination unit 28 that compares the appearance shape of the workpiece W to be inspected detected by the calculation unit 26 with the appearance shape of the normal workpiece W stored by the storage unit 27 to determine the suitability of the workpiece W to be inspected. Is provided.

(4) Reversing unit 3 ... FIGS. 9 to 12
The reversing unit 3 is provided after the front photographing unit 2. That is, four brackets 31 supported by a frame (not shown) are provided above the movement path of the work W in the rear stage of the front side photographing unit 2, and a square support frame 32 is fixed to the lower end of the bracket 31. Two rails 33 extending along the moving direction of the workpiece W are fixed to the lower surface of the support frame 32. A first support portion 34 that supports one end side of the workpiece W is suspended along the rail 33 so as to be movable on the front side of the two rails 33, that is, on the supply side of the workpiece W.

  On the back side of the two rails 33, that is, on the discharge side of the workpiece W, a second support portion 35 that supports the other end side of the workpiece W is suspended so as to be movable along the rail 33. Sliders 36 are respectively provided on the upper surfaces of the first support part 34 and the second support part 35, and these sliders 36 are fitted into the rails 33, whereby the first support part 34 and the second support part 35. Moves along the rail 33 in the direction in which the distance between them changes.

  On the lower surface of the first support portion 34, a driven-side bearing 34a is provided. The driven-side bearing 34a has a rotation center parallel to the central axis in the longitudinal direction of the moving workpiece W. When the reversing mechanism catches the workpiece W, the driven-side bearing 34a supports a grip portion 34b that is coaxial with the central axis in the longitudinal direction of the workpiece W so as to be rotatable. The driven side grip part 34b is a box-like member having an open back side, and this opening part is an insertion part into which one end side of the workpiece W is inserted. The front end of the rotating shaft of the gripping portion 34b protrudes toward the front side of the bearing 34a, and a disk 34c for detecting the rotation angle of the gripping portion 34b is fixed to the protruding portion.

  On the lower surface of the second support portion 35, a drive-side bearing 35 a is provided coaxially with the bearing of the first support portion 34. The driving-side bearing 35a is rotatably supported by the driving-side bearing 35a so as to face the gripping portion 34b provided on the driven-side bearing 34a. The driving-side grip 35b is a box-shaped member that opens on the front side, and the opening is an insertion portion into which the other end of the workpiece W is inserted. The end of the gripping part 35b on the back side of the rotating shaft protrudes further back than the drive-side bearing 35a, and the gear 35c is fixed to the protruding part.

  A rotation mechanism that reverses the gripping mechanism is provided on the left side (right side in FIG. 6) of the drive-side bearing 35a. That is, a bearing 35d for a rotating mechanism is provided on the lower surface of the second support portion 35, and a rotating shaft extending in the conveying direction of the workpiece W is supported by the bearing 35d. The front end of the rotating shaft protrudes to the front side of the bearing, and the output shaft of the driving motor 35e is connected to the protruding portion. The driving motor 35 e is fixed to the lower surface of the second support portion 35. The end on the far side of the rotating shaft projects farther than the bearing 35d, and the gear 35f is fixed to the projecting portion. A timing belt 35g is stretched between the motor-side gear 35f and the gripping gear 35c.

  Two cylinders 37, 38 on the front side and the back side are provided on the left side of the upper surface of the support frame 32. The cylinder 37 on the front side moves the first support portion 34 along the conveying direction of the workpiece W, and the tip of the cylinder rod is fixed to the portion of the first support portion 34 that protrudes from the upper surface of the support frame 32. Is done. The rear cylinder 38 moves the second support part 35 along the conveying direction of the workpiece W, and the tip of the cylinder rod is fixed to a part of the second support part 35 protruding above the support frame 32. Is done.

  On the side of the gripping mechanism, a push-up mechanism that lifts the workpiece W transported to the reversal position from the holder is arranged. The push-up mechanism includes a support member 71 fixed to a frame (not shown), a pair of cylindrical guides 72 provided at a predetermined interval on a horizontal portion of the support member 71, and ascending and descending along the cylindrical guide 72. A pair of guide bars 73 are provided. The lower ends of the pair of guide bars 73 are fixed to each other by a connecting plate 74.

  A push-up plate 75 is fixed to the upper ends of the pair of guide rods 73, and four positioning projections 76 that hold the left and right of the central portion of the work W are provided on the upper surface of the push-up plate 75. The outer dimensions of the four positioning projections 76 in the movement direction of the workpiece W are narrower than the distance in the movement direction of the workpiece W between the support portion 17b on the near side and the support portion 17c on the back side provided in the transfer holder 17. The push-up plate 75 can be moved up and down between the lower surface and the upper surface of the transport holder 17 through the space between the front support portion 17 b and the rear support portion 17 c of the transport holder 17.

  An elevating cylinder 77 is fixed between the pair of cylindrical guides 72 in the horizontal portion of the support member 71. The tip of the cylinder rod of the elevating cylinder 77 is fixed to the center of the lower surface of the push-up plate 75. The stop position on the lower side of the tip of the cylinder lot is a height at which the positioning projection 76 provided on the upper surface of the push-up plate 75 does not hinder the movement of the front conveyance table 10, and the stop position on the ascending side is the gripping portion of the reversing mechanism. This is a height at which the front and back end portions of the workpiece W can be inserted into the insertion portion provided in.

(5) Back side shooting unit 4
A back side photographing unit 4 is provided after the reversing unit 3. The configuration of the back side photographing unit 4 is the same as that of the front side photographing unit 2.

(6) Discharge device 6...
A discharge device 6 is provided at the rear stage of the back side photographing unit 4. The discharge device 6 includes a push-up mechanism having the same configuration as that provided in the reversing unit 3 and a suspension moving mechanism provided above the push-up mechanism. The structure of the push-up mechanism is the same as that of the reversing unit 3 and will not be described.

  The suspension moving mechanism includes one fixed rail 61 provided in a direction orthogonal to the moving direction of the workpiece W with respect to a frame (not shown), that is, in the left-right direction of the inspection apparatus. Two moving rails 62 and 63 are supported on the fixed rail 61 in a direction orthogonal to the fixed rail 61. The two moving rails 62 and 63 are supported so as to be movable independently of the fixed rail 61. The fixed rail 61 is provided with a mechanism for moving the two moving rails 62 and 63 along the fixed rail 61. In this embodiment, the moving mechanism is a cylinder (not shown), but a linear electric actuator or the like can also be used.

  The first moving rail 62 takes out the workpiece W determined as an unacceptable product, and the second moving rail 63 takes out the workpiece W determined as an acceptable product. Each moving rail 62, 63 is provided with an arm 64 extending vertically downward so as to be movable along the length direction of each moving rail 62, 63. Each arm 64 is provided with a mechanism for moving each arm 64. In this embodiment, the moving mechanism is a cylinder (not shown), but a linear electric actuator or the like can be used.

  At the lower end of each arm 64, a gripping portion 65 is provided for gripping and lifting the workpiece W stopped at the discharge position from above. That is, a support plate 65a is horizontally provided at the lower end of each arm 64, and a rail 65b extending to the left and right is fixed to the lower surface of the support plate 65a. A pair of left and right moving blocks 65c are suspended from the rail 65b, and concave portions 65d for sandwiching the workpiece W from the left and right are formed on the opposing surfaces of each moving block 65c. A cylinder 65e for moving each moving block 65c along the rail 65b is fixed to the lower surface of the support plate 65a, and the tip of the cylinder rod is connected to each moving block 65c.

  A chute (not shown) for collecting the workpiece W transported by the gripping portion 65 of the first moving rail 62 is provided at the rejected product take-out position. A plurality of holders 66 for temporarily storing the work W transported by the gripping portion 65 of the second moving rail 63 are provided at the picked-up position of the acceptable product.

[2. Operation of the embodiment]
In order to inspect the appearance of the workpiece W by the appearance inspection apparatus of the present embodiment having the above-described configuration, the following is performed.

(1) Supply of workpiece W When the workpiece W is set in the holder 17 of the front side conveyance table 10, the front side conveyance table 10 is moved to the supply position on the front side of the appearance inspection apparatus. The front-side transport table 10 is moved by rotating the drive shaft 13 by the motor 14 and rotating the male screw on the outer periphery of the drive shaft 13 inside the female screw portion 15. In a state where the front-side transport table 10 is stopped at the supply position, the workpiece W is set on the upper portion of the holder 17. In the set of the workpiece W, the small end of the connecting rod is fitted into the semicircular positioning recess 17d so that the longitudinal direction of the rod portion of the workpiece W coincides with the moving direction, and the substantially circular positioning projection 17e inside the big end. Fit.

(2) Front Side Inspection After the workpiece W is set on the transport holder 17, the drive shaft 13 is driven by the motor 14 to move the front side transport table 10 to the back side of the inspection apparatus. Along with the movement of the front-side transport table 10, the workpiece W on the holder 17 passes below the front-side imaging unit 2. Since the front-side imaging unit 2 is provided with four sets of laser irradiation devices 24 and cameras 25 on a diagonal line, the workpiece W receives laser irradiation from four diagonal directions on the front, rear, left and right. As a result, even if there is a blind spot in one set of laser irradiation device 24 and camera 25, the blind spot portion is also photographed by another set of laser irradiation device 24 and camera 25, and the entire circumference of workpiece W Can be inspected.

  The image data in the four oblique directions of the workpiece W photographed by the four cameras 25 are output to the calculation units 26 connected to the respective cameras 25. In the calculation unit 26, the image data of each camera 25 is processed separately and output to the determination unit 28. The determination unit 28 compares the image data to be inspected obtained from the calculation unit 26 with the image data of the accepted product stored in the storage unit 27 in advance, and the work to be inspected based on a predetermined standard. W pass / fail is determined.

(3) Reversal of work W The front-side transport table 10 that has started moving from the supply position stops when the work W reaches the reversal position after passing through the front-side imaging unit 2. When the workpiece W stops at the reversal position, the lifting cylinder 77 of the lifting mechanism is operated, and the lifting plate 75 fixed to the tip of the cylinder rod starts to rise from the standby position below the base 11. When the push-up plate 75 passes between the support portion 17b on the front side and the support portion 17c on the back side of the transport holder 17, the four positioning projections 76 provided on the surface of the push-up plate 75 are the rod portions of the workpiece W. The workpiece W is lifted from the transfer holder 17 with the pinch in between.

  When the push-up plate 75 further rises and reaches the height of the gripping portions 34b and 35b of the reversing mechanism, the distance between the first support portion 34 and the second support portion 35 is reduced by the two cylinders 37 and 38. It is moved in the narrowing direction. As a result, the small grip on the near side of the workpiece W supported by the push-up plate 75 is fitted so that the driven grip portion 34b provided on the first support portion 34 is covered, and at the back of the workpiece W. The big end is fitted so as to cover the drive side grip 35b provided on the second support 35. After the workpiece W is held from both sides by the two gripping portions 34b and 35d, the lifting plate 75 is lowered to the standby position below the base 11 by driving the elevating cylinder 77 downward.

  In this case, if the angles of both gripping portions 34b and 35d are not horizontal, both ends of the work W on the push-up plate 75 cannot enter the insertion portions of the gripping portions 34b and 35d. Therefore, in this embodiment, the driving side gripping portion 35b is secured by controlling the motor 35e for rotation, and the driven side gripping portion 34b is angled by the disk 34c fixed to the rotating shaft. Is detected by a switch (not shown) to ensure levelness.

  When the push-up plate 75 is lowered, the front-side transport table 10 returns toward the workpiece W supply position. When the front-side transport table 10 leaves the work W reversal position, the back-side transport table 50 enters the work W reversal position and stops there. In the meantime, in the reversing unit 3, the driven side gripping part 34b and the driving side gripping part 35b rotate 180 ° around the rotation axis of the both while holding the workpiece W therebetween. That is, the rotational force of the motor 35e fixed to the second support portion 35 is transmitted in the order of the gear 35f, the timing belt 35g, and the gear 35c, so that the drive-side grip portion 35b fixed to the gear 35c rotates. . Since the driven-side gripping portion 34b is supported so as to be freely rotatable with respect to the bearing 34a, the driven-side gripping portion 34b rotates with the workpiece W as the driving-side gripping portion 35b rotates.

  After the workpiece W is reversed, the push-up plate 75 rises again to the position of the reversing unit 3 through the inside of the transfer holder 17 of the back-side transfer table 50, and the four positioning protrusions 76 provided on the push-up plate 75. To sandwich the rod part of the workpiece W. In this state, the grips 34b and 35b are pulled away from both ends of the workpiece W by widening the distance between the first support 34 and the second support 35 with two cylinders. After the workpiece W becomes free from the gripping portions 34 b and 35 b, the push-up plate 75 is lowered and the work W on the push-up plate 75 is transferred onto the holder 17 of the back side transfer table 50.

(4) Back Side Inspection The back side transfer table 50 that supports the workpiece W on the holder 17 moves to the back side of the appearance inspection apparatus while being driven by the drive shaft 13. In the middle of the movement, the workpiece W passes under the back side photographing unit 4 and is irradiated with laser light and the reflected light is photographed by the camera in the same manner as the front side photographing unit 2 described above. As a result, also for the back side of the work W, image data viewed from four obliquely upward directions is acquired, and by comparing the image data with the reference data stored in the storage unit 27, the pass / fail for the back side of the work W is obtained. A determination is made. Since the back side photographing unit 4 and the front side photographing unit 2 are provided independently for this back side inspection, the front side inspection can be performed independently and simultaneously during the back side inspection.

(5) Discharge of Work The work W that has passed through the back side photographing unit 4 is sent to the discharge position by the back side conveyance table 50. When the back side transfer table 50 stops at the discharge position, the push-up mechanism provided below the discharge position is activated, and the workpiece W is lifted from the transfer holder 17 of the back-side transfer table 50 in the same manner as the push-up mechanism of the reversing unit. .

  When the workpiece W is a rejected product, the first moving rail 62 moves above the workpiece W along the fixed rail 61, and the grip 65 provided at the lower end of the first moving rail 62 The workpiece W on the push-up plate 75 is grasped. That is, when the workpiece W is lifted up between the moving blocks 65c of the gripping portion 65 by the push-up plate 75, the distance between the moving blocks 65c is narrowed by the cylinder 67, and the rod portion of the workpiece W is sandwiched and held from the left and right.

  After the workpiece W is held on the first moving rail 62, the push-up plate 75 is lowered to the standby position below the base 11. When the push-up plate 75 is lowered, the push-up plate 75 and the transfer holder 17 do not interfere with each other, so that the back-side transfer table 50 returns to the position of the reversing unit in order to receive the next workpiece W.

  At the same time, the first moving rail 62 moves toward a chute (not shown) provided on the right side of the base 11 and opens the moving block 65c of the gripping portion 65 in a state where the first moving rail 62 is reached. The workpiece W is discharged into the chute. In this case, the moving rail 62 moves along the fixed rail 61 in the left and right width directions in accordance with the position of the chute, and the vertical arm 64 provided on the moving rail 62 moves along the moving rail 62. By moving from the front side to the back side of the apparatus, the workpiece W supported by the holder 17 of the back side transfer table 50 can be moved in any of the front, rear, left and right directions.

  When the workpiece W is an acceptable product, the workpiece W supported by the holder 17 of the back side transfer table 50 is provided on the opposite side of the base 11 from the rejected product chute by the second moving rail 63. The holder 66 is moved. The movement of the workpiece W by the second moving rail 63 is the same operation as that of the first moving rail 62.

[3. Effects of the embodiment]
The appearance inspection apparatus according to the present embodiment has the following effects.

(1) The 1st inspection conveyance part 1, the front side imaging | photography part 2 which images the front side of the workpiece | work W, the back side imaging | photography part 4 which images the back side of the workpiece | work W, and the 2nd inspection conveyance part 5 are made independent. Therefore, while the second inspection transport unit 5 is inspecting the back side of the work W, the first inspection transport unit 1 can inspect the next work W. As a result, the waiting time for inspection of the workpiece W can be eliminated, and the inspection speed can be improved.

(2) In the appearance inspection apparatus of the present embodiment, since the workpiece W always moves along a certain route, the four cameras 25 always photograph the same portion of the workpiece W. Therefore, it is not necessary to grasp with the camera 25 of the entire shape of the workpiece W, and the pass / fail of the workpiece W can be determined by comparing with the dedicated reference data prepared for each camera 25 and the inspection data. As a result, the process of combining a plurality of image data is not necessary, and the amount of image data to be compared is small for each camera 25, so that the workpiece W has a complicated shape with many irregularities like a connecting rod. The pass / fail can be quickly determined. In addition, since the front-side imaging unit and the back-side imaging unit are each provided with a pass / fail determination processing unit, the determination on the front side and the determination on the back side are performed separately, so that the determination work time can be shortened.

(3) Since the four laser irradiation devices 24 and the camera 25 are arranged diagonally above the moving path of the workpiece W so as to be diagonal to the workpiece W, the workpiece W is a long member along the moving direction. Even so, while the positions of the laser irradiation device 24 and the camera 25 are fixed, the front and upper surfaces and side surfaces of the long member, or the upper surface, the side surfaces, and the rear surface are photographed with a single camera 25. be able to. For this reason, even a relatively large long member can be inspected for appearance with a simple device and a downsized device.

(4) Since the supply position of the work W, the front side photographing unit 2, the reversing unit 3, the back side front side photographing device 4 and the discharge device 6 are all arranged in a straight line along the moving direction of the work W, the width of the left and right of the device is Less is required, and the entire apparatus can be reduced in size.

(5) The reversing unit 3 grips the front side and the back side of the workpiece W in the longitudinal direction and rotates the workpiece W by 180 ° as the longitudinal direction and the movement direction axis. Therefore, the space required for reversing the work W can be a small area with a small width, and the apparatus can be miniaturized.

(6) When the transfer holder 17 holds both ends of the workpiece W and the push-up plate 75 lifts the central portion of the work W, the push-up plate 75 lifts the workpiece W above the holder 17 In addition, the push-up plate 75 and the holder 17 do not interfere with each other. Further, since the push-up plate 75 lifts the center portion of the work W, the work W can be easily reversed by grasping the near side and the far side by the reversing unit 3. Thus, by devising the configuration of the holder 17 for conveyance, the push-up device 75, and the reversing unit 3, the workpiece W can be reliably handled with a simple configuration.

(7) Since this embodiment uses a connecting rod having rings at both ends as the workpiece W, and uses a positioning projection 17e that fits inside the ring as the holder 17 of the front-side conveyance table 10 or the back-side conveyance table 5, the workpiece W The positioning projection 17e does not hinder the photographing by the camera 25, and the appearance of the workpiece W can be inspected with high accuracy. In addition, the positioning recess 17d into which the small end of the workpiece W is fitted is also less than or equal to half the height of the workpiece W, so that the portion hidden behind the positioning recess 17d is also reversed by the back side photographing unit 4 Appearance inspection can be performed.

(8) By using the push-up mechanism having the same configuration in the reversing unit 3 and the discharge device 6, it is possible to reduce the cost by sharing the parts.

[4. Other Embodiments]
The present invention is not limited to the above embodiment. The above embodiments are presented as examples and can be implemented in various other forms. Various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope, gist and equivalent range of the invention. An example is shown below.

(1) The drive mechanism of the front-side transfer table 10 and the back-side transfer table 5 and other drive mechanisms used in the illustrated embodiment are not limited to the drive shaft 13, but a hydraulic or air cylinder, an electric motor A rack and pinion or a linear type electric actuator using as a drive source can be used.

(2) The plurality of laser irradiation devices 24 and the camera 25 are not necessarily arranged on a rectangular diagonal. For example, the two sets of the laser irradiation device 24 and the camera 25 on the right side and the left side of the movement path of the workpiece W can be installed at positions shifted along the longitudinal direction of the movement path. Further, the angle of each camera 25 in the oblique direction is not limited to 45 degrees, and can be appropriately changed according to the height and width of the workpiece W. Preferably, it is good to arrange | position on the extension of the diagonal of the cross-sectional shape orthogonal to the moving direction of the workpiece | work W. It is sufficient that at least four sets of the laser irradiation device 24 and the camera 25 are provided, and it is possible to provide a larger number of sets just above the moving workpiece in order to improve the determination accuracy.

(3) Although the box-shaped member which has an opening part was used as the holding parts 34b and 35b of the inversion part 3, what reverse | inverted by pinching | interposing the workpiece | work W from up and down or right and left can also be used. In addition, although one gripping portion 35b is a driving side and the other gripping portion 34b is a driven side, both gripping portions may be rotated in synchronization by a cylinder or a motor.

W ... Work, 1 ... First inspection transport unit, 2 ... Front side imaging unit, 3 ... Reversing unit, 4 ... Back side imaging unit, 5 ... Second inspection transport unit, 6 ... Discharge device, 10 ... Front side transport Table, 11 ... Base, 12 ... Rail, 13 ... Drive shaft, 14 ... Motor, 15 ... Female thread, 16 ... Slider, 17 ... Holder, 17a ... Base, 17b ... Front side support, 17c ... Back side Supporting part, 17d ... positioning recess, 17e ... positioning projection, 21 ... post, 22 ... bracket, 23 ... arm, 24 ... laser irradiation device, 25 ... camera, 26 ... calculation part, 27 ... storage part, 28 ... determination part, DESCRIPTION OF SYMBOLS 31 ... Bracket, 32 ... Support frame, 33 ... Rail, 34 ... 1st support part, 34a ... Bearing, 34b ... Gripping part, 34c ... Disc, 35 ... 2nd support part, 35a ... Bearing, 35b ... Gripping part , 35c ... gears, 35d ... bearings, 3 e ... motor, 35f ... gear, 35g ... timing belt, 36 ... slider, 37, 38 ... cylinder, 50 ... back side transfer table, 61 ... fixed rail, 62, 63 ... moving rail, 64 ... arm, 65 ... gripping part, 65a ... support plate, 65b ... rail, 65c ... moving block, 65d ... recess, 65e ... cylinder, 66 ... holder, 71 ... support member, 72 ... cylindrical guide, 73 ... guide rod, 74 ... connecting plate, 75 ... push-up Plate, 76 ... positioning protrusion, 77 ... elevating cylinder.

Claims (8)

In a work appearance inspection apparatus that conveys a work in a straight line, images the appearance of the work with a camera, and inspects the appearance of the work,
A first inspection transport unit arranged along a moving direction of the workpiece that moves linearly, a front side imaging unit that images the front side of the workpiece, a reversing unit that inverts the workpiece, A back side imaging unit that images the back side and a second inspection transport unit;
The first inspection transport unit includes a front-side transport table, a moving mechanism unit that moves the front-side transport table from the supply position of the work to the reversing unit via the front-side photographing unit, and the work on the front side. A holder for holding it at a predetermined position on the transfer table;
The front-side imaging unit includes a plurality of sets of laser irradiation apparatuses and cameras arranged on the one side and the other side in the movement direction on the left and right sides of the movement path above the movement path of the work fixed to the holder, respectively. With
The reversing unit includes a push-up member that moves up and down from below the holder, a lift mechanism for the push-up member, a gripping mechanism that supports the workpiece pushed up by the push-up member, and a 180 ° reversal of the gripping mechanism. A rotating mechanism
The back side photographing unit includes a plurality of sets of laser irradiation devices and cameras arranged on the one side and the other side in the movement direction on the left and right sides of the movement path above the workpiece movement path fixed to the holder, respectively. With
The second inspection transport unit includes a back side transport table, a moving mechanism unit that moves the back side transport table from the reversing unit to the discharge position of the work through the back side photographing unit, and the work back side transport table. With a holder to hold it in place on top,
The work appearance inspection apparatus, wherein the front-side photographing unit and the back-side image pickup unit include a quality determination processing unit that determines the quality of the appearance of the work by using video information captured by each camera.   The work visual inspection apparatus according to claim 1, wherein the rotating mechanism reverses the gripping mechanism by 180 ° about the moving direction of the work.   2. The laser irradiation device and the camera arranged on the one side and the other side in the movement direction on both sides of the movement path are provided on a diagonal line of a quadrangle having an intersection on the movement path of the workpiece. Equipment inspection equipment.   The workpiece is a long member extending in the moving direction, and the fixed laser irradiation device and the camera have at least two surfaces of the front surface and the upper surface and the side surface or the upper surface, the side surface, and the rear surface of the long member. The work visual inspection apparatus according to any one of claims 1 to 3, wherein the work visual inspection apparatus is disposed at an angle at which images are simultaneously photographed. The holders provided on the front-side transfer table and the back-side transfer table hold one end side and the other end side of the workpiece,
The push-up member pushes up the central part of the workpiece, lifts the workpiece from the holder,
The work gripping inspection apparatus according to any one of claims 1 to 4, wherein the gripping mechanism holds one end side and the other end side of the work lifted by the push-up member to invert the work. The inversion part includes a first support part and a second support part whose mutual distance changes,
The first support portion is provided with a drive-side grip portion that is rotated 180 ° by a drive source,
The second support portion is provided with a driven grip portion that freely rotates,
6. The driven side gripping part rotates in accordance with the rotation of the driving side gripping part in a state in which the workpiece is held by the driving side gripping part and the driven side gripping part. 6. Equipment inspection equipment.   The work appearance inspection apparatus according to claim 1, wherein the quality determination processing unit is provided in each of the front side imaging unit and the back side imaging unit. A work appearance inspection method using the appearance inspection apparatus according to any one of claims 1 to 7,
The front-side transport table and the back-side transport table alternately stop at the position of the reversing unit,
The first inspection transport unit and the second inspection transport unit capture, move, supply or discharge, lift or receive the workpieces transported by the first inspection transport unit and the second inspection, respectively. A method for inspecting the appearance of a workpiece performed in parallel in a state in which the workpiece conveyed by the conveyance unit does not interfere.