Patent Publication Number: US-2022219857-A1

Title: Box unpacking device and method of unpacking box using the same

Description:
TECHNICAL FIELD 
     The present disclosure relates to a device which unpacks a box which is boxed and sealed, and takes out item(s) accommodated inside the box, and a method using the same. 
     BACKGROUND ART 
     Patent Document 1 etc. proposes a device including a robot for unpacking a cardboard box which is boxed and sealed, and taking out accommodated item(s) inside the box. 
     REFERENCE DOCUMENT OF CONVENTIONAL ART 
     Patent Document 
     [Patent Document 1] JP2013-100118A 
     DESCRIPTION OF THE DISCLOSURE 
     Problem to be Solved by the Disclosure 
     According to the device of Patent Document 1 described above, the cardboard box is cut with a blade of a packing material cutting part. However, the packing material cutting part is installed in a conveying path, and thus, it can only deal with cardboard boxes of a given size and a given seal type. That is, it is difficult to deal with boxes of various sizes and various seal types. 
     The present disclosure is made in view of such a situation, and one purpose thereof is to provide a box unpacking device and a method of unpacking a box which are capable of dealing with boxes of various sizes and various seal types. 
     SUMMARY OF THE DISCLOSURE 
     A box unpacking device according to one aspect of the present disclosure includes a robot and a cutting device. A robot hand is attached to a wrist of the robot. The robot hand has a holding device configured to hold a packed box. The cutting device has a cutting blade of which the point is oriented downward or obliquely downward, and the robot moves the box held by the holding device in a vertical plane. 
     According to this configuration, the robot can move the box held by the holding device upward in the vertical plane to press the surface to be cut open against the cutting blade, and can move the box along the extending direction of the point of the cutting blade in the vertical plane to cut open the surface to be cut open. Therefore, the box can be unpacked while dealing with the various sizes of the box and various seal types. In addition, since the surface of the box is oriented upward when it is cut open, an accommodated item(s) inside the box is brought closer to the lower part by its own weight, thereby reducing the possibility of the damage to the accommodated item(s) by the cutting blade. 
     The robot may include a robot body including the wrist to which the robot hand having the holding device is attached, and a robot controller configured to control operation of the robot body and the holding device. The robot controller may control the robot body so that the robot body holds the box located at a given position by the holding device and moves the box held by the holding device at least in the vertical plane to cut open an upwardly oriented surface of the box by the cutting blade to open the box. 
     Here, “cutting open the surface of the box” means that a cut line which can reach an interior space, or a linear opening is formed in the surface of the box. 
     According to this configuration, the robot body is controlled automatically or manually to unpack the box while dealing with the various sizes of the box and the various seal types. 
     The controller may control the robot body so that the robot body holds a surface of the box other than the upper surface while placing the wrist at the side of the box, and then moves the box at least in the vertical plane to cut open the upper surface of the box by the cutting blade to open the box. 
     According to this configuration, the upper surface of the box can be cut open. When the up-and-down direction does not exist in the accommodated item(s), the opened box can be further flipped upside down to drop the accommodated item(s), so that the accommodated item(s) can be taken out from the box. 
     The robot may further change an angle of the box held by the holding device in a rotating direction in which the box is flipped upside down. 
     According to this configuration, since the lower surface of the box held by the holding device can be made to face the cutting blade, the lower surface of the box can be cut open. 
     The robot may include a robot body including the wrist to which the robot hand having the holding device is attached, and a robot controller configured to control operation of the robot body and the holding device. The robot controller may control the robot body so that the robot body changes the angle of the box held by the holding device at least in the rotating direction in which the box is flipped upside down, and then cuts open, by the cutting blade, a surface of the box that is oriented upward or obliquely upward to open the box. 
     The robot controller may control the robot body so that the robot body holds at least the upper surface of the box while placing the wrist above the box, then changes the angle of the held box in the rotating direction in which the box is flipped upside down, and then moves the box at least in the vertical plane to cut open, by the cutting blade, a lower surface of the box that is oriented upward or obliquely upward by the angle change to open the box. 
     According to this configuration, in a case where the box located at a given position is arranged such that only the upper surface thereof can be held (e.g., a case where a large number of boxes are stuck in multiple stages and, in each stage, a plurality of boxes are arranged in a matrix form, and the box located at the give position is a box in the upper-most stage), the box located at the given position can easily be held and the lower surface of the box can be cut open. 
     The robot controller may control the robot body so that the robot body holds a surface of the box other than a lower surface while placing the wrist at the side of the box, then changes the angle of the held box in the rotating direction in which the box is flipped upside down, and then moves the box at least in the vertical plane to cut open, by the cutting blade, the lower surface of the box that is oriented upward or obliquely upward by the angle change to open the box. 
     According to this configuration, in a case where the box located at a given position is arranged such that the side surface thereof can be held (e.g., a case where a large number of boxes are arranged in line and the box located at the give position is a box at the front end), the box located at the given position can easily be held and the lower surface of the box can be cut open. 
     The robot controller may control the robot body so that the robot body opens the box held by the holding device, and turns the surface cut open by the cutting blade downward to drop the accommodated item of the box. 
     According to this configuration, the accommodated item(s) of the opened box can be taken out easily by the robot. 
     The box may have a bottom surface, a top surface opposing to the bottom surface, and a side surface connecting the entire perimeter of the bottom surface and the entire perimeter of the top surface. The box may be located at the given position so that the top surface becomes the upper surface. The robot controller may control the robot body so that the robot body holds a surface of the box other than the bottom surface while placing the wrist above the box, then changes the angle of the held box in the rotating direction in which the box is flipped upside down, and then moves the box at least in the vertical plane to cut open, by the cutting blade, the bottom surface of the box that is oriented upward or obliquely upward by the angle change to open the box, and then turns the bottom surface cut open by the cutting blade downward to drop an accommodated item of the box. 
     According to this configuration, the robot can cut open the bottom surface to open the box, and turn the opened box upside down to take out the accommodated item(s). As a result, when the up-and-down direction exists in the accommodated item(s), the accommodated item(s) can be taken out in a proper direction. 
     The boxes may be placed as a box aggregate on a pallet. The holding device may be provided with a box position detector configured to detect the position of the box. The robot controller may hold, by the holding device, the box located at the given position of the box aggregate placed on the pallet based on the position of the box detected by the box position detection. 
     When the robot is program controlled, a box which is a detection target is designated in advance and the position thereof is also identified. However, the actual position of the box includes an error originating from the position error of the pallet, the arrangement error of the box when forming the box aggregate, etc. According to this configuration, for example, by correcting the position of the detection-target box to the position which is detected by the box position detector, the box can be held exactly. 
     The cutting blade of the cutting device may be disposed at a position where the robot is able to move the holding device of the robot hand below the cutting blade. 
     According to this configuration, the robot can press the box held by the holding device against the cutting blade from below the cutting blade, and can cut open the box. 
     The robot may be a vertical articulated robot. 
     According to this configuration, since the robot can put against the cutting blade the box held by the holding device in a given posture so as to cut open the box, the box can be unpacked easily while dealing with the various sizes of the box and the various seal types. 
     Moreover, a method of unpacking a box according to another aspect of the present disclosure is a method of unpacking a box by using a box unpacking device including a robot and a cutting device, a robot hand being attached to a wrist of the robot, the robot hand having a holding device configured to hold a packed box, and the cutting device having a cutting blade of which the point is oriented downward or obliquely downward. The method includes the step of (A) moving, by the robot, the box held by the holding device in a vertical plane. 
     According to this configuration, the box can be unpacked while dealing with the various sizes of the box and the various seal types. In addition, since the surface of the box is oriented upwardly when it is cut open, the accommodated item(s) inside the box is brought closer to the lower part by its own weight, thereby reducing the possibility of the damage to the accommodated item(s) by the cutting blade. 
     Effect of the Disclosure 
     According to the box unpacking device of the present disclosure, the box can be unpacked to take out the accommodated item(s) therein without damaging the accommodated item(s) inside the box, while dealing with the various sizes of the box and the various seal types. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a layout design view of one example of a box unpacking system including a box unpacking device of one embodiment of the present disclosure. 
         FIG. 2  is a perspective view illustrating a robot and a depalletizing area. 
         FIG. 3  is a view illustrating a box position measuring operation which is the first half of a depalletizing operation. 
         FIG. 4  is a front view illustrating a configuration of a holding device. 
         FIG. 5  is a block diagram illustrating a configuration of a control system of the box unpacking device of  FIG. 1 . 
         FIG. 6  is a flowchart illustrating the outline of a box unpacking operation of the box unpacking device of  FIG. 1 . 
         FIG. 7  is a flowchart illustrating the detail of the box unpacking operation of the box unpacking device of  FIG. 1 . 
         FIG. 8A  is a view illustrating a box lifting operation which is the second half of the depalletizing operation. 
         FIG. 8B  is a view illustrating the box lifting operation which is the second half of the depalletizing operation. 
         FIG. 8C  is a view illustrating a cardboard box cutting operation. 
         FIG. 8D  is a view illustrating the cardboard box cutting operation. 
         FIG. 8E  is a view illustrating the cardboard box cutting operation. 
         FIG. 8F  is a view illustrating the cardboard box cutting operation. 
         FIG. 8G  is a view illustrating the cardboard box cutting operation. 
         FIG. 8H  is a view illustrating the cardboard box cutting operation. 
         FIG. 8I  is a view illustrating a situation inside a box during the cardboard box cutting. 
         FIG. 8J  is a view illustrating the cardboard box cutting operation. 
         FIG. 8K  is a view illustrating product(s) (accommodated item(s)) taking-out operation. 
         FIG. 8L  is a view illustrating the product(s) (accommodated item(s)) taking-out operation. 
         FIG. 8M  is a view illustrating the product(s) (accommodated item(s)) taking-out operation. 
         FIG. 8N  is a view illustrating an empty box discharging operation. 
         FIG. 8O  is a view illustrating the empty box discharging operation. 
         FIG. 9  is a view illustrating another mode of the depalletizing operation. 
     
    
    
     MODES FOR CARRYING OUT THE DISCLOSURE 
     Hereinafter, embodiments of a box unpacking device of the present disclosure will be described with reference to the drawings. Note that, below, the same reference characters are assigned to the same or corresponding elements throughout the drawings to omit redundant description. Moreover, since the following drawings are to explain the present disclosure, an element which is unrelated to the present disclosure may be omitted, the dimension may not be exact because of an exaggeration etc., and the mutually-corresponding elements may not match up with each other in a plurality of drawings. Moreover, the present disclosure is not limited to the following embodiments. 
     Embodiment 
       FIG. 1  illustrates one example of a layout design view for a box unpacking system including a box unpacking device of one embodiment of the present disclosure.  FIG. 2  is a perspective view illustrating a robot and a depalletizing area.  FIG. 3  is a view illustrating a box position measuring operation which is the first half of a depalletizing operation.  FIG. 4  is a front view illustrating a configuration of a holding device. This box unpacking system is also a work environment of a box unpacking device  100 . 
     [Configuration] 
     {Configuration of Hardware} 
     Referring to  FIGS. 1 to 4 , the box unpacking system includes a robot  1 , a cutting device  40 , a depalletizing area  51 , an actual pallet conveyor  52 , a pallet magazine  53 , a bag unpacking machine  54 , a product taking-out conveyor  55 , and an empty box discharging conveyor  56 . The robot  1  and the cutting device  40  constitute the box unpacking device  100 . Operation of the robot  1  is controlled by a robot controller  3  ( FIG. 5 ), and operations of the components of the box unpacking system other than the robot  1  are controlled by a system controlling device (not illustrated). The control of the operation of the robot  1  and the control of the box unpacking system are performed coordinatively with each other. 
     In this box unpacking system, a pallet  31  where a box aggregate  32  which is formed by suitably gathering cardboard boxes (hereinafter, simply referred to as “the box”)  33  is placed (disposed) (hereinafter, the pallet where the box aggregate  32  is placed is referred to as “the actual pallet”) is conveyed on the actual pallet conveyor  52 , and it is stopped at the depalletizing area  51 . Accommodated item(s) (product(s))  36  is accommodated inside the box  33 , and the box  33  is sealed (closed) by a tape  34 . When the actual pallet  31  is stopped, the robot  1  picks up the box  33  from the box aggregate  32 , opens the box  33  by using the cutting device  40 , and drops the accommodated item(s)  36  on the product taking-out conveyor  55 . Then, the product taking-out conveyor  55  conveys the accommodated item(s)  36  to the bag unpacking machine  54 , and the bag unpacking machine  54  opens a bag of the accommodated item(s)  36  and suitably processes the accommodated item. The robot  1  drops the empty box  33  on the empty box discharging conveyor  56 . Then, the empty box discharging conveyor  56  takes out the empty box  33 . When a series of box unpacking operations are repeated and the top of the pallet  31  becomes empty, the empty pallet  31  is conveyed to the pallet magazine  53  and the next actual pallet  31  is stopped at the depalletizing area  51 , by the actual pallet conveyor  52 . The empty pallets  31  are stacked on the pallet magazine  53 . 
     Next, the box unpacking device  100  is described in detail. 
     &lt;Robot  1 &gt; 
     The robot  1  may have, at a wrist  2   a , a robot hand including a holding device  10  which holds a packed box  33 , and be capable of moving the box  33  held by the holding device  10  in a vertical plane. It is because, by the robot  1  moving the box  33  held by the holding device  10  upwardly in the vertical plane, a surface to be cut open can be pressed against a cutting blade  41 , and by moving the box  33  in an extending direction of the point of the cutting blade  41  in the vertical plane, the surface to be cut can be cut open. Here, “cutting open the surface of the box  33 ” means that a cut line which can reach an interior space, or a linear opening is formed in the surface of the box  33 . The robot  1  may further change the angle of the box  33  held by the holding device  10  in a rotating direction in which the box  33  is made upside down. According to this configuration, since a lower surface of the box  33  held by the holding device  10  can be turned toward the cutting blade  41 , the lower surface of the box  33  can be cut open. 
     In this embodiment, the robot  1  can move the box  33  held by the holding device  10  in the vertical plane, and can change the angle of the box  33  held by the holding device  10  in the rotating direction in which the box is flipped upside down. 
     The robot  1  may be a vertical articulated robot, a horizontal articulated robot, a delta robot, a parallel link robot, or a robot dedicated for box unpacking. 
     The robot  1  includes a robot body  2  and a robot controller  3  (see  FIG. 5 ). 
     Referring to  FIG. 3 , the robot  1  is comprised of, for example, a 6-axis vertical articulated robots, and the robot body  2  is comprised of a vertical articulated robotic arm. Since the vertical articulated robot is well-known, the detailed description is omitted. A robot hand provided with the holding device  10  (here, substantially, the robot hand is only comprised of the holding device  10 ) is attached to the wrist  2   a  of the robot body  2 . 
     &lt;Cardboard Box  33 &gt; 
     The box  33  may be what can accommodate the accommodated item(s)  36  therein and can be sealed (closed), and can be cut open by the cutting blade  41 . The form of the box  33  is not limited in particular. Here, the box  33  is configured to have a bottom surface, a top surface which opposes to the bottom surface, and a side surface which connects the entire perimeter of the bottom surface and the entire perimeter of the top surface. In detail, the box  33  is a cardboard box which is boxed (where item(s) is accommodated). Here, the shape of the box  33  is a rectangular parallelepiped, for example. The box  33  is comprised of a body part  33   a  of a rectangular pillar shape comprised of four side walls of the rectangular parallelepiped, and flaps  33   b  formed at an upper end and a lower end of each side wall of the body part  33   a.    
     A top wall and a bottom wall are formed by bending and suitably combining the flaps  33   b , and closing both the end surfaces of the rectangular-pillar-shaped body part  33   a . Note that, in this embodiment, when not distinguishing the upward and downward directions of the box  33  in particular, the walls at both the ends of the rectangular-pillar-shaped body part  33   a  are referred to as “the end wall(s).” Each end wall is sealed with an adhesive tape (hereinafter, simply referred to as “the tape”)  34  so that the flaps  33   b  will not open. Although the shape and the number of flap(s)  33   b  and the sealing mode by the tape  34  may be changed variously according to the form of the end walls of the box  33 , they are as follows if a general form is described. 
     For example, there is a box in which each of a pair of opposing short sides and a pair of opposing long sides of the end surface of the rectangular of the body part  33   a  is used as a bendable part, and the end wall is formed by the flaps  33   b  for the pair of short sides having the same rectangular shape and the flaps  33   b  for the pair of long sides having the same rectangular shape, which extend from the respective pairs of bendable parts. By bending the bendable parts of the pair of short sides of the rectangular end surface, the flaps  33   b  for the pair of short sides are made to extend along the end surface with a gap therebetween. Then, by bending the bendable parts of the pair of long sides of the rectangular end surface, free edges of the flaps  33   b  for the pair of long sides are abutted to each other. Then, the tape  34  pastes together the flaps  33   b  for the pair of long sides so that it covers the abutted part and straddles the flaps  33   b  for the pair of long sides. As a result, side edges of the flaps  33   b  for the long sides overlap with the bendable parts of the short sides of the body part  33   a . The tape  34  pastes together the flaps  33   b  for the long sides and the side plates of the box  33  so that it covers the overlapping part and straddles the flaps  33   b  for the long sides and the bendable parts of the short sides of the body part  33   a . Normally, the pasting of the side edges of the flaps  22  for the long sides and the short sides of the body part  33   a  is performed at two locations of the body part  33   a . As a result, when the end wall is seen as a front view, the tape  34  forms the H-shape (hereinafter, this pasting mode of the tape is referred to as the “H-shaped tape pasting mode”). Note that the pasting of the side edges of the flaps  22  for the long sides and the short sides of the body part  33   a  may be omitted. In this case, if the end wall is seen as the front view, the tape  34  forms the I-shape (hereinafter, this pasting mode of the tape  34  is referred to as the “I-shape tape pasting mode”). In this embodiment, the I-shape tape pasting mode is illustrated. However, the box unpacking operation which will be described below may completely be applied to the H-shaped tape pasting mode. 
     Moreover, the following is another mode. The end wall is comprised of a single flap  33   b. The flap  33   b  overlaps at its edge with a bottom edge of the side wall of the body part  33   a , and the tape  34  pastes together the flap  33   b  and the side wall of the body part  33   a  so that it covers the overlapping part and straddles the flap  33   b  and the side wall of the body part  33   a.    
     &lt;Box Aggregate  32 &gt; 
     Referring to  FIG. 3 , the boxes  33  are stacked so as to form the box aggregate  32  on the pallet  31 . The box aggregate  32  may be the boxes  33  disposed regularly. The reason why the regularity is required is that it is necessary to identify the position of each box  33  on the pallet  31  in order for the robot  1  to hold the box  33  disposed on the pallet  31 . 
     In detail, for example, the box aggregate  32  is comprised of one or more stacked stages, which forms, as a whole, a rectangular pillar shape with the flush circumferential surfaces. Each stage is comprised of one or more boxes  33  placed so as to form a geometric shape as a whole in a plan view. Here, the geometric shape is square. Of course, it may be other geometric shapes. Each box  33  is placed so that its top surface becomes an upper surface. 
     &lt;Cutting Device  40 &gt; 
     Referring to  FIG. 2 , the cutting device  40  is installed near the robot  1 . The cutting device  40  has the cutting blade  41 , of which the point is oriented downwardly. Note that the point of the cutting blade  41  may be oriented obliquely downwardly. The cutting blade  41  may have the point which is oriented downwardly or obliquely downwardly. The shape of the cutting blade  41  is not limited in particular, but it may be a disk, knife, or chain saw shape. The cutting blade  41  may be fixed or movable. 
     The cutting blade  41  is disposed at a position where the robot  1  is able to move the holding device  10  below the cutting blade  41 . This is because the robot  1  can press the box  33  held by the holding device  10  against the cutting blade  41  from below the cutting blade  41 , and can cut open the box  33 , if the cutting blade  41  is disposed in this way. 
     In detail, the cutting device  40  includes the cutting blade  41  of a disk shape, and a carrier  42 , for example. In  FIG. 2  (and  FIGS. 8D-8H  and J), the carrier  42  is drawn transparently for convenience of description. The carrier  42  is supported by a suitable support structure at a necessary height, and is formed in a frame where a lower end thereof opens. Further, the cutting blade  41  is rotatably attached to the carrier  42  in a vertical plane through a horizontal rotation axis  42   a  (see  FIG. 8I ). A lower end of the cutting blade  41  is exposed from the lower end of the carrier  42 . The cutting blade  41  is rotated by a motor (not illustrated), for example. 
     &lt;Accommodated Item (Product)  36 &gt; 
     The accommodated item  36  (see  FIG. 4 ) is not limited in particular. It may be a product or a postal item. The product may include a bagged product (for example, a foodstuff, a plastic bag where nuts are stuffed, a commodity), an industrial material, and a component. 
     &lt;Holding Device  10 &gt; 
     Here, referring to  FIGS. 3 and 4 , the holding device  10  includes a body part  11 , an attaching part  12 , a pair of gripper members  13 A and  13 B, a suction part  18 , and a three-dimensional (3D) position measuring instrument (box position detector)  20 . Note that, in  FIG. 4 , illustration of the 3D position measuring instrument  20  is omitted. The 3D position measuring instrument  20  will be described later in detail. Moreover, in  FIG. 4 , for convenience, a left-and-right direction and an up-and-down direction in the drawing are defined as a left-and-right direction and an up-and-down direction of the holding device  10 , respectively. 
     The body part  11  is formed in a frame which has an inverted U-shape in the cross section when seen in the left-and-right direction, and extends in the left-and-right direction (particularly, see  FIG. 3 ). 
     The attaching part  12  of a cylindrical shape having a flange at a tip end is provided so as to stand upwardly from a center part of the body part  11 . The center axis of the attaching part  12  constitutes a reference axis AR of the holding device  10 . The holding device  10  is attached to the wrist  2   a  of the robot body (robotic arm)  2  so that the reference axis AR becomes in agreement with the twist-rotation axis of the wrist  2   a . Moreover, as will be described later, the holding device  10  is positioned so that, by the robot body  2 , the body part  11  is located above the cardboard box  33  and the reference axis AR is substantially in agreement with the center axis of the cardboard box  33 . 
       FIG. 4  illustrates the holding device  10  in a posture where the reference axis AR extends in the up-and-down direction (vertically). 
     The pair of gripper members  13 A and  13 B are attached to the body part  11  so that their base-end parts are separated by a given distance in a given direction perpendicular to the reference axis AR (here, the left-and-right direction). The base-end parts of the pair of gripper members  13 A and  13 B are attached to the body part  11  so as to be rotatable on a pair of rotation axes A 1  and A 2  perpendicular to the extending direction of the reference axis AR and the given direction. The parts of the body part  11  to which the base-end parts of the pair of gripper members  13 A and  13 B are attached, respectively, are separated from the reference axis AR of the body part  11  by an equal distance in the given direction. The pair of gripper members  13 A and  13 B are driven by a pneumatic controlling circuit (not illustrated). In the drawings other than  FIGS. 4 and 81 , the pair of gripper members  13 A and  13 B are illustrated by one reference character “ 13 ” for simplification. 
     The pair of gripper members  13 A and  13 B are formed, for example, when seen in the extending directions of the respective rotation axes A 1  and A 2 , in a plate shape having a cross-sectional shape bent in a direction or to the side in which the pair of gripper members  13 A and  13 B approach each other (hereinafter, referred to as inward or the inside). 
     Pawls  15 A and  15 B which protrude inwardly are provided at tip ends of the pair of gripper members  13 A and  13 B, respectively. Moreover, friction members  17 A and  17 B are attached to parts of inner surfaces of the pair of gripper members  13 A and  13 B, on the tip-end sides from the bent parts, respectively. The pair of friction members  17 A and  17 B may be members with a large friction coefficient, and the pair of friction members  17 A and  17 B may be members made of rubber, sponge, or sandpaper. 
     The length and the bending degree of the pair of gripper members  13 A and  13 B are set (designed) so that, in a state where the body part  11  is located above the cardboard box  33  (in detail, in a state where the suction part  18  sucks a center part of the upper surface of the cardboard box  33 ), for example, the pair of pawls  15 A and  15 B may be stuck into upper parts of the left-and-right side walls of the cardboard box  33 , respectively, and the pair of friction members  17 A and  17 B contact the upper parts of the left-and-right side walls of the cardboard box  33 , respectively. 
     However, depending on the state of the accommodated item(s)  36  (for example, when the number of accommodated items  36  is small), the length and the bending degree of the pair of gripper members  13 A and  13 B may be set (designed) so that, in a state where the body part  11  is located above the cardboard box  33  (in detail, in a state where the suction part  18  sucks the center part of the upper surface of the cardboard box  33 ), the pair of pawls  15 A and  15 B are stuck into a part of any one of the left-and-right side walls of the cardboard box  33 , and the pair of friction members  17 A and  17 B contact a part of any one of the left-and-right side walls of the cardboard box  33 . 
     The suction part  18  is provided to a lower surface of the body part  11 . The suction part  18  is comprised of a vacuum suction pad, for example. The suction part  18  is provided, for example, so that the center axis is in agreement with the reference axis AR. The suction part  18  performs sucking/releasing operation by the pneumatic controlling circuit described above. 
     &lt;3D Position Measuring Instrument  20 &gt; 
     As illustrated in  FIG. 3 , the 3D position measuring instrument  20  as the box position detector is provided to a side part of the body part  11  of the holding device  10 . The 3D position measuring instrument  20  measures a three-dimensional position of the box  33 . The 3D position measuring instrument  20  may be comprised of a three-dimensional vision camera, an image sensor, or an ultrasonic distance sensor, for example. Here, the 3D position measuring instrument  20  is comprised of the three-dimensional vision camera. 
     {Configuration of Control System} 
       FIG. 5  is a block diagram illustrating a configuration of a control system of the box unpacking device  100  of  FIG. 1 . 
     Referring to  FIG. 5 , the robot controller  3  is comprised of a sole controller which performs a centralized control or a plurality of controllers which perform a distributed control. Here, the robot controller  3  is comprised of the sole controller which performs the centralized control. The installed location of the robot controller  3  is not limited in particular. The robot controller  3  is installed at a base part (see  FIG. 2 ) of the robot body  2 , for example. The robot controller  30  is provided with a processor Pr and a memory Me, for example. The robot controller  3  controls operations of the robot body  2  and the holding device  10  by the processor Pr reading and executing a given control program stored in the memory Me. In detail, the robot controller  3  is comprised of a microcontroller, an MPU, an FPGA (Field Programmable Gate Array), a PLC (Programmable Logic Controller), or a logic circuit, for example. 
     In detail, the robot controller  3  controls the motor which drives each joint of the robot body  2  to control operation of the robot body  2 , and controls the pneumatic controlling circuit of the holding device  10  to control operation of the holding device  10 . Moreover, the robot controller  3  identifies the 3D position of the box  33  based on measurement data of the 3D position measuring instrument  20 . Then, the robot controller controls the operations of the robot body  2  and the holding device  10  so as to hold the box  33  based on the identified 3D position of the box  33 , and makes the robot body  2  and the holding device  10  perform the box unpacking operation according to the given control program described above. 
     The cutting device  40  is suitably controlled by the system controlling device (not illustrated) described above. Note that the robot controller  3  may control the operation of the cutting device  40 . 
     [Operation] 
     Next, operation of the box unpacking device  100  configured as described above is described. First, an outline of the operation of the box unpacking device  100  is described using  FIGS. 2, 3, and 6 . 
       FIG. 6  is a flowchart illustrating the outline of the box unpacking operation by the box unpacking device of  FIG. 1 . The operations of the robot  1  and the holding device  10  are carried out by the control of the robot controller  3 . 
     Referring to  FIGS. 2, 3, and 6 , the robot  1  holds the box  33  by using the holding device  10  (Step S 1 ). 
     Next, the robot  1  moves the box  33  to the cutting device  40  (Step S 2 ). 
     Then, the robot  1  unpacks the box  33  by using the cutting blade  41  of the cutting device  40  (Step S 3 ). 
     Next, operation of the box unpacking device  100  is described in detail using  FIGS. 2-4, 7, and 8A-8N . This detailed operation is carried out as follows, for example. Of course, it may be carried out by operation of other modes. Below, an operation under a holding mode in which the robot body  2  holds surfaces other than the bottom surface of the box  33  (the upper surface and the side surface) by positioning the wrist  2   a  above the box  33 , is illustrated. Note that the cutting blade  41  is rotating. 
     First, as illustrated in  FIG. 3 , the robot  1  measures, by using the 3D position measuring instrument  20 , the 3D position of one of the plurality of boxes  33  which constitute the box aggregate  32  on the pallet  31 , of which the top surface is exposed and which is located at the given position. Although the box  33  of the measurement target is designated in advance by the given control program and its 3D position is also identified, since the actual 3D position of the box  33  includes an error originating from the position error of the pallet  31 , the arrangement error of the box  33  when forming the box aggregate  32 , etc., it is corrected to a 3D position which is obtained by measuring the error (Step S 1 - 1 ). Particularly, in the box unpacking device  100 , since the box  33  is griped by the pair of gripper members  13 A and  13 B of the holding device  10 , it is important for the 3D position of the box  33  to be exact in order to grip the box  33  correctly. 
     Next, as illustrated in  FIG. 8A , the robot  1  sucks the top surface of the designated box  33  by using the suction part  18  (see  FIG. 4 ) (Step S 1 - 2 ). 
     Next, as illustrated in  FIG. 8B , the robot  1  lifts the sucked box  33  to a given gripping position (Step S 1 - 3 ). 
     Then, as illustrated in  FIG. 8C , the robot  1  grips the upper part of the box by the pair of gripper members  13 A and  13 B ( 13 ) (Step S 1 - 4 ). Therefore, the box  33  is held firmly by the robot  1 , and it becomes possible to convey (move) the box  33 . 
     Next, as illustrated in  FIG. 8D , the robot  1  moves the held box  33  to in front of the cutting blade  41  of the cutting device  40  (Step S 2 ). In detail, the robot  1  changes the angle of the box  33  in the rotating direction in which the box is flipped upside down when holding the box  33  to change the posture of the box  33  so that the top surface of the held box  33  is turned obliquely upward. By this posture change, the accommodated item(s)  36  (see  FIG. 81 ) inside the box  33  is brought closer to a lower part of the box  33 . This forms a gap in an upper part of the interior space of the box  33 . Since the gap is formed in the upper part of the interior space of the box  33 , even when the cutting blade  41  relatively moves with respect to the box  33  while the point is stuck into the box, the cutting blade  41  will not damage the accommodated item(s) inside the box  33 . Then, the robot  1  positions an end (a right end in  FIG. 8D ) of one of the short sides of the box  33  at the left side of a bottom end part of the cutting blade  41 . 
     Then, the robot  1  moves the box  33  horizontally to the right side in  FIG. 8D  along an extending surface of the cutting blade  41 . 
     Therefore, as illustrated in  FIG. 8F , one side of the tape  34  at the bottom side of the box  33  is cut in the transverse direction (Step S 3 - 1 ). Note that, in the case of the H-shaped tape pasting mode, the tape corresponding to one of the short sides of the box  33  is also cut. Moreover, the cutting operation described above is carried out by moving the box  33  in a vertical plane including the extending surface of the point of the cutting blade  41 . 
     Next, as illustrated in  FIG. 8G , the robot  1  rotates the box  33  by  180  degrees on the center axis of the wrist  2   a  (the reference axis AR of the holding device  10 ), and then cuts the other side of the tape  34  at the bottom side of the box  33  in the transverse direction, similarly to Step S 3 - 1  (Step S 3 - 2 ). Note that, in the case of the H-shaped tape pasting mode, the tape corresponding to the other short side of the box  33  is also cut. 
     Then, as illustrated in  FIG. 8H , the robot  1  turns the box  33  vertically upward by rotating the box  33  by 90 degrees on the center axis of the wrist  2   a , and positions the center of one side of the short sides (right side in  FIG. 8H ) of the box  33 , at the left side of the bottom end of the cutting blade  41 . 
     Then, the robot  1  moves the box  33  horizontally to the right side in  FIG. 8H  along the extending surface of the cutting blade  41 . At this time, as illustrated in  FIG. 81 , since the accommodated item(s)  36  inside the box  33  is brought closer to the lower part of the box  33  and the gap is formed in the upper part of the interior space of the box  33 , the cutting blade  41  will not damage the accommodated item(s) inside the box  33 . 
     Therefore, as illustrated in  FIG. 8J , the part located in the bottom surface of the tape  34  at the bottom side of the box  33  is cut in the longitudinal direction (Step S 3 - 3 ). Note that, in the case of the H-shaped tape pasting mode, the part located in the bottom surface of the tape  34  at the bottom side of the box  33  is similarly cut in the longitudinal direction. Moreover, the cutting operation at Step S 3 - 3  is also carried out by moving the box  33  in the vertical plane including the extending surface of the point of the cutting blade  41 . 
     As a result, the sealed state of the bottom wall of the box  33  is canceled by cutting all the tapes  34  pasted on the flaps  33   b.    
     Next, the robot  1  moves the box  33  onto the product taking-out conveyor  55  which is an accommodated item table (Step S 4 ). 
     Then, as illustrated in  FIGS. 8K and 8L , the robot  1  twists the box  33  so that the accommodated item(s)  36  is discharged from the box  33  onto the product taking-out conveyor  55 , while pushing away the flaps  33   b  (Step S 5 ). 
     In this case, the box  33  may be twisted so as to become sideways, or may be twisted so as to stand upright. Alternatively, the posture of the box  33  may be changed in modes other than twisting. 
     Therefore, as illustrated in  FIG. 8M , the accommodated items  36  accommodated inside the box  33  fall altogether onto the product taking-out conveyor  55  and are discharged (Step S 6 ). 
     Next, as illustrated in  FIG. 8N , the robot  1  moves the empty box  33  onto the empty box discharging conveyor  56  (Step S 7 ). 
     Next, as illustrated in  FIG. 80 , the robot  1  releases the box  33  by canceling the suction by the suction part  18  of the holding device  10  and canceling the gripping by the pair of gripper members  13 . Then, the empty box  33  falls onto the empty box discharging conveyor  56  (Step S 8 ). The fallen empty box  33  is taken out by the empty box discharging conveyor  56 . 
     Then, the robot  1  repeats the operation described above. 
     According to such an embodiment, the robot  1  can change the angle of the box  33  held by the holding device  10  in the rotating direction in which the box is flipped upside down so that the surface of the box  33  to be cut open is turned to be perpendicular to the cutting blade  41 , and can move the box  33  upward in the vertical plane to press the surface to be cut open against the cutting blade  41 , and can move the box  33  in the extending direction of the cutting blade  41  in the vertical plane to cut open the surface to be cut open. 
     Therefore, the box  33  can be unpacked while dealing with the various sizes of the box  33  and various seal types. In addition, since the surface to be cut open is oriented upwardly when it is cut open, the accommodated item(s)  36  inside the box  33  is brought closer to the lower part by its own weight, thereby reducing the possibility of the damage to the accommodated item(s)  36  by the cutting blade  41 . 
     Modification 1 
       FIG. 9  is a view illustrating another mode of the depalletizing operation. Referring to  FIG. 9 , in Modification 1 of this embodiment, a plurality of boxes  33  are serially disposed on the pallet  31 , as the box aggregate  32 . The number of rows is not limited in particular. Such a case may be that the box  33  is vertically elongated, and when the boxes  33  are stacked, the box aggregate  32  becomes unstable, for example. 
     In this modification, the box  33  at the front end of the box row of the box aggregate  32  is the box located at the given position. At each point in time, the robot body  2  holds the surfaces other than the lower surface of the box  33  (here, three side surfaces (the front surface, the left side surface, and the right side surface)) located at the front end of the box row so that the wrist  2   a  is located forward (sideways) of the box  33 . 
     Other matters are completely the same as the above embodiment. 
     According to Modification 1, when the box  33  located at the given position is disposed so that the side surface of the box  33  is able to be held, the box  33  located at the given position can be held easily, and the lower surface of the box  33  can be cut open. 
     Modification 2 
     Modification 2 is similar to the modification other than followings. 
     In Modification 2, the robot body  2  holds the box  33  by using the holding device  10  similar to Modification 1, and then opens the box  33  without flipping the box  33  upside down. In detail, at Steps S 3 - 1  to S 3 - 3  of the flowchart in  FIG. 7 , the tape  34  at the top side of the box  33  is cut. 
     According to Modification 2, the upper surface in the arrangement state of the box  33  can be cut open. When the up-and-down direction does not exist in the accommodated item(s)  36 , the opened box  33  is further flipped upside down to drop the accommodated item(s)  36 , so that the accommodated item(s)  36  can be taken out from the box  33 . 
     Other Embodiments 
     In the above embodiment, Modification 1, and Modification 2 (hereinafter, they are simply referred to as “the above embodiment”), the box unpacking device  100  may be provided with a manipulator for manipulating the robot  1 , and unpack the box  33  by an operator manipulating the robot  1  using the manipulator. In this case, for example, the box unpacking device  100  may be configured so that the operator operates the robot body  2  and the holding device  10  without an intervention of the control device. Moreover, for example, a manipulation signal may be inputted into the robot controller  3  by the manipulation of the manipulator, and the box unpacking device  110  may be configured so that the robot controller  3  controls the operations of the robot body  2  and the holding device  10  according to the manipulation signal. 
     In the above embodiment, the box  33  may not be sealed by the tape  34 . For example, the box  33  may be sealed by engaging the flaps with each other, or pasting the flaps together. Alternatively, the box  33  may be sealed by attaching the end walls by a suitable mounting member (fitting, fastening, etc.). 
     In the above embodiment, although the box holding part is provided with an upper wall holding part (suction part  18 ) and a pair of side wall holding parts (gripper members  13 A and  13 B), either one may be provided. 
     Moreover, although in the above embodiment the cardboard boxes  33  are stacked, the placing mode of the cardboard boxes  33  is not limited to this configuration. For example, rows of the cardboard boxes may be stacked in a plurality of stages. In such a case, the upper wall holding part (suction part  18 ) may be omitted. 
     Moreover, the direction in which the holding device  10  holds the cardboard box  33  is not limited in particular. For example, when the cardboard box  33  is placed so that the top wall is oriented sideways or downwardly, the holding device  10  may hold the cardboard box  33  from the side or below. In short, the holding device  10  may hold the cardboard box  33  so that the body part  11  becomes adjacent to the end wall of the cardboard box  33  at the opposite side of the end wall to be cut open. 
     Moreover, the box holding part ( 18 ,  13 ) may hold the cardboard box  33  by supporting the part of the cardboard box  33  other than the end wall to be cut open, and, for example, it may hold a ridge line part or a corner part of the cardboard box  33 . 
     Although in the above embodiment the suction part  18  is illustrated as the upper wall holding part, the upper wall holding part may be able to hold and support the upper wall of the cardboard box  33 . For example, the upper wall holding part may be provided with a pawl which can stick into the upper wall and support the cardboard box  33 . 
     Although in the above embodiment the side wall holding part is comprised of the pair of gripper members  13 A and  13 B, the side wall holding part may support the side wall and hold the cardboard box  33 . For example, the side wall holding part may pinch the pair of side walls by moving in the left-and-right direction. 
     Moreover, although in the above embodiment the gripper member  13  of the holding device  10  is driven by the pneumatic controlling circuit, the power source of the gripper member  13  is not limited to this configuration. For example, the gripper member  13  may be driven by a motor. 
     Moreover, in the above embodiment, the cutting device  40  may have a plurality of cutting blades  41 . 
     Moreover, in the above embodiment, the 3D position measuring instrument  20  may be omitted. 
     It is apparent for the person skilled in the art that many improvements and other embodiments are possible from the above description. Therefore, the above description is to be interpreted only as illustration. 
     INDUSTRIAL APPLICABILITY 
     The box unpacking device of the present disclosure is useful in the technical field of devices configured to open the box which is boxed and sealed, and take out the accommodated item(s) inside the box. 
     DESCRIPTION OF REFERENCE CHARACTERS 
     
         
           1  Robot 
           2  Robot Body 
           2   a  Wrist 
           3  Robot Controller 
           10  Holding Device 
           11  Body Part 
           12  Attaching Part 
           13 ,  13 A,  13 B Gripper Member 
           15 A,  15 B Pawl 
           17 A,  17 B Friction Member 
           18  Suction Part 
           20  3D Position Measuring Instrument (Box Position Detector) 
           31  Pallet 
           32  Box Aggregate 
           33  Cardboard Box (Box) 
           33   a  Body Part 
           33   b  Flap 
           34  Adhesive Tape (Tape) 
           36  Accommodated Item 
           40  Cutting Device 
           41  Cutting Blade 
           42  Carrier 
           51  Depalletizing Area 
           52  Actual Pallet Conveyor 
           53  Pallet Magazine 
           54  Bag Unpacking Machine 
           55  Product Taking-out Conveyor 
           56  Empty Box Discharging Conveyor 
           100  Box Unpacking Device 
         Pr Processor 
         Me Memory