Adhesion inspection apparatus and adhesion inspection method using the same

The present invention relates to an adhesive strength inspection device, and more particularly to an adhesive strength inspection device that inspects the adhesive strength at the time of assembling or packaging a packaging box or the like.

For example, when forming a packaging box with cardboard or the like, after putting an object to be packaged in the box body, an adhesive such as hot melt is applied to the flap of the packaging box, and the flap of the box body is passed through this adhesive. The packaging boxes are sealed by overlapping each other. At that time, it is necessary that the flaps are securely adhered by the adhesive. As a conventional adhesive force inspection device, there are some methods for indirectly determining. For example, the amount of the applied adhesive, the adhesive temperature, the coating position, the coating range, and the like are detected by a camera, an infrared sensor, or the like, and the adhesive strength is estimated.

Further, as a method for directly inspecting the adhesive strength, a box sealing defect inspection device is disclosed (see Patent Document 1). This sealing defect inspection device circulates along the lid suction path La in which the lid suction tool 31 is lined up in the box transport path, and the lid lifting path Lb that follows the lid suction path La and separates from the box transport path. The lid suction tool moving device 30 and the lid detection sensor 50 that detects the upper surface of the lid 3 that has been peeled off from the box body 2 and lifted by the lifting force exerted on the lid 3 by the lid suction tool 31 in the lid lifting path Lb. It has. When such a sealing inspection device is used, when the lid 3 has poor adhesion, the lid 3 is lifted away from the box body 2, and the lifted lid 3 is detected by a detection means such as an optical sensor, and finally. It is possible to inspect for defective sealing (adhesion).<patcit num="1"><text>Japanese Patent Application Laid-Open No. 2005-104568 (See FIG. 1 in particular)</text></patcit>

<p> However, the conventional adhesive force inspection device has the following inconveniences. That is, the adhesive force cannot be accurately grasped by the method of indirectly estimating the adhesive force. Further, even in the case of the above-mentioned conventional example of direct inspection, since the inspection can be performed only when the lid 3 is completely peeled off from the box body 2, the lid 3 is not completely peeled off, but it is intermediate when the adhesive strength is weak. It is not possible to inspect for defects. That is, if such an adhesive force is weak, the lid 3 may be peeled off from the box body 2 after the inspection, and such an intermediate defect cannot be inspected. Further, since the lifted lid 2 is detected by an optical sensor or the like to inspect for poor adhesion, complicated work such as adjusting the optical axis of the equipment constituting the sensor is required.</p>

<p> The present invention improves the inconvenience of such a conventional adhesive force inspection device, and in particular, provides an adhesive force inspection device that can reliably detect intermediate defects and does not require complicated work such as adjusting the optical axis of the device. The purpose is to do.</p>

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [Overview] First, FIG. 1 is a perspective view of an overall outline of the adhesive force inspection device 1 according to the present embodiment. As shown in this figure, the adhesive force inspection device 1 includes a vacuum pad 5 that directly adsorbs to the packaging box 3, a suction tube 7 that communicates the vacuum pad 5 with a vacuum source (not shown) such as a vacuum pump, and a suction tube 7. The inspection arm 9 that supports the vacuum pad 5, the rotating shaft 11 that rotatably supports the inspection arm 9, the driving means 13 that rotates the rotating shaft 11, and the torque generated in the driving means 13. It is equipped with a torque sensor 15 for detecting. Each of these components is supported on a predetermined frame 17 (see FIG. 2) so that it can move together with the frame 17. In FIG. 1, for convenience of explanation, the rotating shaft 11, the driving means 13, and the torque sensor 15 are described as not being fixed, but in reality, the rotating shaft 11 is fixed by a bearing and the driving means. The 13 housings are also fixed so that they do not rotate. Each component will be described below.

[Vacuum pad] The vacuum pad 5 is made of a flexible material such as rubber and has a substantially triangular pyramid shape. The size of the vacuum pad 5 has a diameter narrower than the length at both ends of each flap 4 of the packaging box 3 (vertical direction in FIG. 1), and the entire vacuum pad 5 is adsorbed on the surface of the flap 4. You can do it. The place where the vacuum pad 5 is adsorbed is the area bonded by the hot melt. In the figure, it is described that two vacuum pads are attracted to the upper flap 4, but this is a simplified description, and in fact, the lower flap 4 also has two vacuum pads as well. Adsorb. Further, although not shown, the four vacuum pads 5 are similarly attracted to the upper and lower flaps on the opposite side of the packaging box 3. Therefore, a total of eight vacuum pads 5 are attracted to one packaging box 3 (see also FIG. 3).

[Suction tube] Next, the suction tube 7 will be described. The suction tube 7 is a tubular member that communicates with the vacuum pad 5 via an inspection arm 9 described later. The suction pipe 7 is connected to a vacuum source (vacuum pump), and communicates with or shuts off the vacuum source by the action of a control unit (not shown). As a result, the suction force can be generated in the vacuum pad 5 and conversely, the suction force can be extinguished. Since the vacuum pad 5 is supported on the inspection arm 9 and rotates during the inspection process, the suction tube 7 is preferably made of a flexible material. Specifically, a tubular member such as rubber or plastic is desirable. However, since the internal pressure is reduced, it is necessary to have a predetermined rigidity and not to be crushed. In the present embodiment, the suction tube 7 is connected to the vacuum pad 5 via the inspection arm 9, but the present invention is not limited to this, and the suction tube 7 may be directly connected to the vacuum pad 5. .. Further, not necessarily in the case of suction, air may be made to flow back to positively separate the vacuum pad 5 from the packaging box 3. In this case, a positive pressure is applied to the suction tube 7.

[Inspection arm] Next, the inspection arm 9 will be described. The inspection arm 9 is a rod-shaped member extending in the vertical direction, and supports the vacuum pad 5 at one end (lower end in FIG. 1). On the other hand, the other end of the inspection arm 9 is connected to a predetermined block member 10. Then, the rotating shaft 11 is fitted to the block member 10. Therefore, when the rotation shaft 11 rotates, the inspection arm 9 can also rotate accordingly. The inspection arm 9 may be directly connected to the rotation shaft 11 without using the block member 10.

[Rotating shaft] Next, the rotation shaft 11 will be described. The rotating shaft 11 is arranged so as to extend substantially parallel to the flap 4 at a predetermined distance from the packaging box 3. Then, it is rotatably supported by a bearing (not shown), and only rotation is allowed.

[Drive means] Next, the driving means 13 will be described. The drive means 13 according to the present embodiment is a servomotor, and the servomotor 13 is connected to one end of the rotation shaft 11 in order to rotate the rotation shaft 11. The servomotor 13 can detect the rotation angle, and the detected rotation angle can be output to the outside as an angle signal. The angle signal is transmitted to a control unit (not shown) to calculate the rotation angle. As described above, the housing of the servomotor is fixed by a predetermined fixing means so as not to rotate.

[Torque sensor] Next, the torque sensor 15 will be described. The torque sensor 15 is connected to the servomotor 13 so as to detect the torque generated in the rotating shaft 11 and output the torque information to the outside. The torque detected here is a torque generated when the vacuum pad 5 is attracted to the flap 4 and the inspection arm 9 is retracted as described later, and poor adhesion is determined based on this torque information. Therefore, a signal related to the torque is also transmitted to the control unit.

[Other] In addition to the above-mentioned main components, a peeling detecting means (not shown) for detecting peeling of the flap 4 is separately provided in the present embodiment, although it is not essential. Various types of peeling detection means can be considered, but in the present embodiment, an optical sensor (not shown) is provided in the vicinity of the inspection arm. This optical sensor is composed of a light source and a light receiver, and is designed to block light from the light source to the light receiver when the adhesive portion of the flap is peeled off by a predetermined amount or more during the inspection of the adhesive strength. By blocking the light, poor adhesion can be detected. In addition, a CCD camera may be used to photograph the vicinity of the flap, and the peeling of the flap may be detected by image processing.

[Inspection procedure] Next, the inspection procedure by the adhesive strength inspection device 1 according to the present embodiment will be described. FIG. 2 is a plan view of the packaging line 21, the adhesive strength inspection device 1, and the frame 17. As shown in FIG. 2, the adhesion inspection device 1 according to the present embodiment is installed on the packaging line 21. In this figure, the packaging box 3 continuously moves from left to right on the roller conveyor 23 (arrow P in the figure). On the other hand, the adhesive force inspection device 1 is supported on the frame 17 so as to reciprocate along the rail 25 parallel to the packaging line 21 (arrow Q in the figure). When actually inspecting the adhesive strength, the adhesive strength inspection device 1 moves toward the downstream side of the packaging line 21 at the same speed as the moving speed of the packaging box 3. As a result, the relative speed between the packaging box 3 and the adhesive strength inspection device 1 becomes 0, and the inspection process can be executed. Then, when the inspection of one packaging box 3 is completed, the product moves to the upstream side of the packaging line 21 and returns to the position of the next packaging box 3, and the same inspection process is repeated again.

FIG. 3 is a schematic view of the packaging box 3 and the adhesive strength inspection device 1 viewed from the upstream side to the downstream side of the packaging line 21. As shown in this figure, the vacuum pad 5 is adsorbed on each of the flaps 4 on the upper left, lower left, upper right and lower right of the packaging box 3. Then, since two vacuum pads 5 are adsorbed on each flap 4, a total of eight vacuum pads 5 are adsorbed on one packaging box 3. The vacuum pad 5 is supported on the inspection arm 9, and as shown in FIG. 4, the inspection arm 9 rotates in a direction retracting from the packaging box 3 as the servomotor 13 rotates. Here, as shown in FIG. 4, the adhesive strength inspection device 1 has a length L of 85 mm from the rotation center of the inspection arm 9 to the center of the vacuum pad 5, and a distance H from the rotation center to the upper surface of the packaging box. It is set to about 50 mm. However, this is an example, and the length L and the distance H are appropriately set according to the size of the packaging box 3.

FIG. 5 is a diagram showing the relationship between the angle A of the inspection arm and the torque value detected by the torque sensor 15. Here, the horizontal axis is the angle of the inspection arm 9, and the vertical axis is the torque value. This figure illustrates both the case where normal bonding is performed and the case where bonding is poor. In the normally bonded packaging box 3, the torque value increases with the rotation of the inspection arm 9, and exceeds the threshold torque. Then, when the inspection arm 9 is further rotated, the maximum torque value is shown. When the inspection arm 9 is further rotated beyond this, the adhesive portion is peeled off and the torque value is reduced. On the other hand, in the case of poor adhesion, the shape of the basic curve is similar to that in the case of normal adhesion, but the torque value increases with the rotation of the inspection arm 9, but the maximum torque is reached before the threshold torque is reached. It shows a value, and then the torque value decreases.

In the adhesive strength test under the conditions of the present embodiment, as shown in FIG. 5, the maximum torque value is shown when the angle of the inspection arm 9 is between about 7 ° and 8 ° even in the case of normal adhesion and poor adhesion. .. Therefore, if a defect is determined in the adhesive strength test in this angle range, the adhesive defect can be detected with high accuracy. Here, the threshold torque to be set is determined by a number of experiments.

A specific inspection procedure will be described on the premise of the above configuration and inspection principle. FIG. 6 is a table showing the relationship between the position of the inspection arm 9 (arm angle), the on / off of suction of the vacuum pad 5, and the output voltage from the torque sensor 15, and the time elapses to the right. .. First, in the first stage, the angle of the inspection arm 9 is in the retracted position (for example, A = 10 ° in FIG. 4). At this time, since the vacuum pad 5 is not in contact with the packaging box 3, the suction is off. And since no torque is generated, the output voltage is 0.

Next, in the advancing section of the second stage, the inspection arm 9 approaches the packaging box 3 so as to be in the advancing position (for example, A = 0 ° in FIG. 4). At this time as well, the vacuum pad 5 is suction off. However, the output voltage of the torque value is generated as the inspection arm 9 rotates. However, since the actual inspection has not started, the output voltage here is ignored.

Subsequently, in the third stage, the angle of the inspection arm 9 reaches the forward position (for example, A = 0 ° in FIG. 4). Therefore, the vacuum pad 5 comes into contact with the predetermined position of the packaging box 3, so that the vacuum pad 5 is suction-on. At this point, the inspection arm 9 remains stopped, so the output voltage of the torque value does not change much from the previous section. The position where the vacuum pad 5 is adsorbed is the adhesive region by an adhesive such as hot melt.

In the subsequent fourth stage (reverse section), the servomotor 13 rotates to retract the inspection arm 9. At this time, since the vacuum pad 5 remains suction-on, torque is generated so that the inspection arm 9 is kept in the vicinity of the packaging box 3, and an output voltage corresponding to this is generated. Then, when the inspection arm 9 reaches a position corresponding to the determination timing, the servomotor 13 is stopped to stop the inspection arm 9. Then, the output voltage from the torque sensor at this point is detected.

In the fifth step that follows, the angle of the inspection arm 9 is fixed and the vacuum pad 5 is also left on suction. Then, since the determination is completed when the predetermined time elapses, the vacuum pad 5 is sucked off while the angle of the inspection arm 9 is fixed as the sixth step. As a result, the restraint of the inspection arm 9 from the packaging box 3 is released, and the output voltage of the torque value approaches 0.

Finally, as the seventh step, the series of inspection steps is completed by returning the inspection arm 9 to the initial retracted position. When one inspection step is completed, as described above, the adhesive strength inspection device 1 moves to the upstream side of the packaging line 21 and starts the inspection of the next packaging box 3. The packaging box 3 determined to have poor adhesion by inspection is removed from the packaging line 21 downstream.

FIG. 6 shows a graph of the output voltage in the case of normal adhesion (OK) and the case of poor adhesion (NG1, NG2). By repeating a number of experiments to determine the threshold value of the output voltage, it is possible to accurately inspect the adhesive strength only by the output voltage from the torque sensor 15.

Further, in order to further improve the inspection accuracy, a peeling detecting means (not shown) is provided in the present embodiment. This peeling detecting means is arranged in the vicinity of the inspection arm 9, and can detect when the flap 4 having poor adhesion is peeled off and tries to separate from the packaging box 3. By using such a peeling detecting means, even if the adhesive defect cannot be detected by the torque value, the adhesive defect can be reliably detected.

The above has described the case where the suction on and off of the vacuum pad 5 is positively controlled to perform the adhesive strength test, but the present invention is not limited to this. For example, the suction force of the vacuum pad 5 may be set so as to generate a torque that is detached from the flap that is normally adhered but not from the flap that is poorly adhered. If the suction force is set in this way, the vacuum pad is automatically removed from the normally bonded packaging box in the inspection process, so that the control of suction on / off is simplified.

Further, as shown in FIG. 4, the center of rotation when the upper flap 4 of the packaging box 3 is peeled off is the upper left corner of the packaging box 3. On the other hand, the center of rotation of the inspection arm 9 exists above the distance H. Therefore, when the flap 4 and the inspection arm 9 are both oriented in the vertical direction, they are parallel to each other, but as the inspection arm 9 rotates, the angle between the inspection arm 9 and the flap 4 becomes higher. The gap between them increases. When such an angle deviation occurs, even if the packaging box 3 has poor adhesion, when the vacuum pad 5 is removed from the flap 4, a large torque that occurs when the packaging box 5 is normally adhered may be generated. As described above, if a large torque is generated in spite of the poor adhesion, an accurate adhesion inspection becomes impossible.

In order to solve such a problem, the distance H from the rotation center of the flap 4 to the rotation center of the inspection arm 9 may be minimized. Specifically, it is desirable that the rotating shaft 11 is as close as possible to each corner of the packaging box 3.

It can be applied to a means for directly inspecting the adhesive strength of a packaging box or the like using an adhesive.

<figref num="1">It is a schematic perspective view of the adhesive force inspection apparatus which concerns on one Embodiment of this invention.</figref><figref num="2">It is a schematic plan view which shows the adhesive force inspection apparatus arranged on a packaging line.</figref><figref num="3">It is the figure which looked at the adhesive force inspection apparatus from the upstream side of a packaging line.</figref><figref num="4">It is a figure explaining the operation of the adhesive force inspection apparatus.</figref><figref num="5">It is a figure explaining the inspection principle of the adhesive force inspection apparatus which concerns on this invention.</figref><figref num="6">It is a figure explaining the specific operation of the adhesive force inspection apparatus which concerns on this invention.</figref>

Code description

1 Adhesive strength inspection device 3 Packaging box 4 flaps 5 vacuum pad 7 Suction tube 9 Inspection arm 10 block members 11 Rotating shaft 13 Drive means (servo motor) 15 Torque sensor 17 frames 21 Packaging line 23 Roller conveyor 25 rails