JP7758015B2 - Appearance sorting device - Google Patents

Description

The present invention relates to an appearance sorting device.

Patent Document 1 describes an apparatus that aligns hexahedral workpieces on a conveying table, captures images of the workpieces on the conveying table with a camera, and inspects their appearance. Furthermore, paragraph 0075 of Patent Document 1 describes a method for ejecting the workpieces, in which compressed air is sprayed from the inner periphery of the conveying table, causing the workpieces to fly to the outer periphery of the conveying table and be guided into a storage box.

JP 2013-148362 A

However, because this ejection method is not mechanical, foreign matter adhering to the compressed air nozzle can change the path of the compressed air ejection, preventing the workpiece from being ejected reliably and resulting in the workpiece being ejected, for example, to the center of the transport table. It is also possible that a workpiece that is attached to a worker's sleeve may end up falling to the center of the transport table. Because the center of the transport table is outside the workpiece transport path, such workpieces will remain on the transport table even if the lot is replaced. As a result, there is a risk that such workpieces will be returned to the transport path in the event of an equipment malfunction and be mixed into the lot.

The present invention was made to solve the above problems, and aims to provide an appearance sorting device that does not leave workpieces on the conveying table.

The appearance sorting device of the present invention is an appearance sorting device that includes a disk-shaped conveying table that rotates with parts placed on it, a camera that is provided on the circular path along which the parts are conveyed on the rotating conveying table and captures images of the parts being conveyed, and a sensor that scans the conveying table in areas other than the circular path.

This invention provides an appearance sorting device that does not leave workpieces on the conveyor table.

FIG. 1 is a plan view schematically showing an example of an appearance sorting apparatus according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing the respective scanning areas of the camera of the appearance inspection unit and the sensor of the workpiece residue inspection unit in the appearance sorting apparatus shown in FIG.

The appearance sorting device of the present invention will be described below.
However, the present invention is not limited to the following configurations, and can be applied by making appropriate modifications within the scope of the present invention. Note that the present invention also includes a combination of two or more of the individual desirable configurations described below.

Figure 1 is a plan view showing a schematic example of an appearance sorting device according to an embodiment of the present invention.

The appearance sorting device 10 shown in Figure 1 inspects the appearance of workpieces W, which are parts to be sorted, and sorts the workpieces W based on the inspection results. It is equipped with a conveying table 11, a hopper 12, a bowl feeder 13, a linear feeder 14, an alignment guide 15, multiple appearance inspection units 20, a workpiece discharge unit 16, and a workpiece residue inspection unit 30.

Here, the workpiece W is a rectangular (hexahedral) chip component such as a capacitor or inductor, but the type and shape of the components to be sorted by the appearance sorting device 10 are not particularly limited.

The transport table 11 is in the shape of a transparent disk. It is preferably made of glass (glass table), but may also be made of a transparent resin such as polycarbonate. The transport table 11 is configured to be rotatable in a horizontal plane around the center O of the disk as an axis, and rotates with the workpiece W placed on it. The transport table 11 may transport the workpiece W intermittently.

The hopper 12 receives workpieces W and determines the amount of workpieces remaining on the ball feeder 13 based on the detection results of a sensor (not shown) attached to the ball feeder 13. Based on this determination, a certain amount of workpieces W is then fed into the ball feeder 13. The sensor attached to the ball feeder 13 may be, for example, an optical sensor, which is set to react to the workpieces W. If the optical sensor does not react for a certain period of time, it is determined that the amount of workpieces W fed in is low.

A lid (not shown) may be provided on the hopper 12, and the workpiece W may be fed into the ball feeder 13 by opening and closing the lid, or a piezoelectric element (not shown) may be connected to the hopper 12, and the piezoelectric element may transport the workpiece W to the ball feeder 13.

The bowl feeder 13 is vibrated by a piezoelectric element or the like, and transports the workpieces W to the linear feeder 14, which will be described later. The bowl feeder 13 is equipped with a sensor, as described above, and the amount of workpieces W is determined by the sensor's response.

A piezoelectric element (not shown) is connected to the linear feeder 14, and the workpiece W is transported to the transport table 11 by vibrations applied by the piezoelectric element. The linear feeder 14 and transport table 11 are not in contact with each other, and the linear feeder 14 is positioned above the transport table 11 at a fixed distance. The workpiece W is pushed out of the linear feeder 14 and placed on the transport table 11.

By adjusting the vibration of the piezoelectric element of the linear feeder 14 and the rotation speed of the conveying table 11, the workpieces W are lined up at equal intervals on the conveying table 11.

The alignment guide 15 is positioned at a distance from the conveying table 11, but it does not interfere with the workpiece W, ensuring that the workpiece W maintains a constant posture.

Although not shown, a sensor that reacts to the workpiece W may be placed in front of or behind the alignment guide 15. This sensor may be used to determine the amount of workpiece W supplied to the transport table 11.

Each visual inspection unit 20 is composed of a camera 21 such as an image sensor. The camera 21 is provided on the annular path (workpiece transport path) 17 along which the workpiece W placed on the rotating conveyor table 11 is transported. The camera 21 of each visual inspection unit 20 captures images of different surfaces of the workpiece W being transported. Each visual inspection unit 20 also has a light source (not shown). For example, a ring light or the like is used as the light source. Image data from each visual inspection unit 20 is transferred to a PC (not shown), which determines whether the workpiece W is good or defective and ejects the workpiece W based on these results. In this way, the annular path 17 along which the workpiece W is transported corresponds to the annular area scanned by the camera 21 for visual inspection of the workpiece W, and is usually located at the outermost periphery of the disc-shaped conveyor table 11.

The workpiece discharge section 16 has nozzles (not shown) that blow compressed air, arranged from the inner periphery of the conveyor table 11 toward the outer periphery, and the compressed air blows the workpieces W out of the conveyor table 11. A storage box (BIN, not shown) is provided outside the conveyor table 11 to catch the blown-out workpieces W, and the workpieces W are sorted and discharged based on the results of the discrimination.

As described above, the workpieces W supplied from the linear feeder 14 onto the conveying table 11 are transported in a circular pattern as the conveying table 11 rotates, creating a circular transport path 17 for the workpieces W. However, based on the inspection results from the visual inspection unit 20, the workpieces W are typically discharged from the conveying table 11 by the workpiece discharge unit 16 before completing one rotation on the conveying table 11. In other words, the trajectory of a workpiece W successfully discharged from the conveying table 11 by the workpiece discharge unit 16 is arc-shaped. However, because the workpiece discharge unit 16 blows away the workpieces W with compressed air, some workpieces W1 may pass through the workpiece discharge unit 16 without being discharged by the workpiece discharge unit 16. The trajectory of such workpieces W1 is circular. Furthermore, some workpieces W2 may remain in an area other than the workpiece W's transport path 17 (for example, the center of the conveying table 11) without being stored in a storage box. The trajectory of these remaining workpieces W2 is also circular.

The work residue inspection unit 30 is provided to detect such workpieces W2. The work residue inspection unit 30 consists of two parts. One is a sensor 31, which is set to react to workpieces W2. The other is an actuator 32 connected to the sensor 31.

The sensor 31 scans the conveying table 11. The sensor 31 is positioned in an area other than the annular path 17 along which the workpiece W is transported, and scans this area from above the conveying table 11. By using the sensor 31 to scan the conveying table 11 in an area other than the annular conveying path 17 of the workpiece W in this way, it is possible to detect workpiece W2 remaining in an area other than the conveying path 17 of the workpiece W. This makes it possible to prevent workpiece W from remaining on the conveying table 11. Here, it is preferable for the sensor 31 to scan the inside of the conveying path 17 of the workpiece W (the side closer to the center O of the conveying table 11).

In addition, the sensor 31 can scan the conveying table 11 in a circular pattern by rotating the conveying table 11. This allows the area on the disk-shaped conveying table 11 to be scanned efficiently.

Sensor 31 is preferably an image sensor such as a camera or line sensor. The resolution of the image sensor is preferably 508 dpi or more and 1270 dpi or less, and more preferably 1270 dpi or more and 2540 dpi or less.

The actuator 32 moves the sensor 31 in the radial direction of the conveying table 11. This allows the sensor 31 to scan a desired area of the conveying table 11. More specifically, the actuator 32 is configured to be capable of linear movement and is positioned from the center O of the conveying table 11 toward the outside of the conveying table 11. By operating the actuator 32, the sensor 31 moves in the radial direction of the conveying table 11. The sensor 31 can move in a direction toward the outer periphery of the conveying table 11, or conversely, in a direction toward the inner periphery of the conveying table 11.

Figure 2 is a diagram showing the respective scanning areas of the camera of the visual inspection unit and the sensor of the workpiece residue inspection unit in the visual sorting device shown in Figure 1.

As shown in Figure 2, the sensor 31 is moved radially by the actuator 32, scanning multiple annular areas 33 on the conveying table 11. This allows the entire disc-shaped conveying table 11 to be imaged without omission, even if an inexpensive, ordinary image sensor with a certain level of resolution is used as the sensor 31. On the other hand, even if such an ordinary image sensor images the entire conveying table 11, it may not be able to capture the workpiece W2 due to insufficient resolution.

More specifically, multiple annular areas 33 are scanned by repeatedly moving the position of the sensor 31 in the radial direction of the conveying table 11 using the actuator 32 and scanning with the sensor 31 while it is fixed. The multiple annular areas 33 have the same center (which coincides with the center O of the disk-shaped conveying table 11) but different radii. The width of each annular area 33 is normally the same. In other words, the width of the imaging area for each revolution of the image sensor serving as the sensor 31 is normally the same. Note that "width" here refers to the length in the radial direction of the conveying table 11.

Unlike Figure 2, the conveying table 11 may be scanned in a spiral pattern by rotating the conveying table 11 while moving the sensor 31 with the actuator 32.

In either case, the scanning ranges of the sensor 31 for each revolution may overlap. That is, in the case shown in Figure 2, adjacent annular regions 33 may overlap each other.

As shown in Figure 2, the area scanned by sensor 31 (the area imaged by the image sensor) is preferably inside the annular area 22 scanned by camera 21 of the visual inspection unit 20. This allows sensor 31 to efficiently detect remaining workpiece W2 that cannot be detected by camera 21 of the visual inspection unit 20.

However, the area scanned by sensor 31 may include area 22 scanned by camera 21 of visual inspection unit 20. In other words, the image sensor serving as sensor 31 may capture at least a portion of the area captured by camera 21 of visual inspection unit 20. For example, the outermost annular area 34 shown in Figure 2 may overlap with annular area 22 scanned by camera 21.

If workpiece W2 remains at this point, an alarm connected to the appearance sorting device 10 is sounded, or another method is used to notify the worker and have them remove the workpiece W2. The position of the remaining workpiece W2 may be displayed on a display (not shown) connected to the appearance sorting device 10. An air nozzle (not shown) may also be attached to the actuator 32, and the remaining workpiece W2 may be blown away by the air nozzle. Alternatively, the remaining workpiece W2 may be sucked up by the air nozzle. When the workpiece W2 is removed by the worker or by the air nozzle, the conveying table 11 is scanned again to check for any remaining workpiece W2.

As a result, the lot can be changed without any workpieces W remaining on the transport table 11, preventing them from being mixed into the lot.

In addition, workpiece W1 that is not discharged by the workpiece discharge unit 16 and remains on the workpiece W transport path 17 can be detected by the camera 21 of the appearance inspection unit 20.

This specification discloses the following:

<1>
a disc-shaped conveying table that rotates with parts placed on it;
a camera provided on a circular path along which the parts on the rotating conveying table are conveyed, the camera capturing an image of the parts being conveyed;
a sensor that scans the conveying table in an area other than the annular path.

<2>
The appearance sorting device according to <1>, further comprising an actuator connected to the sensor and configured to move the sensor in a radial direction of the conveying table.

<3>
The appearance sorting device according to <2>, wherein the sensor is moved in the radial direction by the actuator to scan a plurality of annular regions on the conveying table.

＜4＞
<4> The appearance sorting device according to any one of <1> to <3>, wherein the area scanned by the sensor is inside a circular area scanned by the camera.

<5>
<4> The appearance sorting device according to any one of <1> to <4>, wherein the sensor is an image sensor.

10 Appearance sorting device 11 Conveying table 12 Hopper 13 Bowl feeder 14 Linear feeder 15 Alignment guide 16 Work discharge section 17 Circular path along which the work is transported (work transport path)
20 Appearance inspection unit 21 Camera 22 Annular area scanned by the camera of the appearance inspection unit 30 Workpiece residue inspection unit 31 Sensor 32 Actuator 33 Annular area scanned by the sensor 34 Outermost annular area scanned by the sensor W, W1, W2 Workpiece (component)
O Center of transport table

Claims (5)

a disc-shaped conveying table that rotates with parts placed on it;
a camera provided on a circular path along which the parts on the rotating conveying table are conveyed, the camera capturing an image of the parts being conveyed;
a sensor that scans the conveying table in an area other than the annular path. The appearance sorting device of claim 1, further comprising an actuator connected to the sensor and moving the sensor in the radial direction of the conveying table. The appearance sorting device of claim 2, wherein the sensor scans multiple annular areas on the conveying table by being moved in the radial direction by the actuator. The appearance sorting device of claim 1 or 2, wherein the area scanned by the sensor is inside the annular area scanned by the camera. 3. The appearance sorting device according to claim 1, wherein the sensor is an image sensor.