Box unpacking device and method of unpacking box using the same

A box unpacking device 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. The robot can move the box held by the holding device in a vertical plane, and change an angle of the box in the vertical plane.

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

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 detector.

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.

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.1illustrates 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.2is a perspective view illustrating a robot and a depalletizing area.FIG.3is a view illustrating a box position measuring operation which is the first half of a depalletizing operation.FIG.4is a front view illustrating a configuration of a holding device. This box unpacking system is also a work environment of a box unpacking device100.

Referring toFIGS.1to4, the box unpacking system includes a robot1, a cutting device40, a depalletizing area51, an actual pallet conveyor52, a pallet magazine53, a bag unpacking machine54, a product taking-out conveyor55, and an empty box discharging conveyor56. The robot1and the cutting device40constitute the box unpacking device100. Operation of the robot1is controlled by a robot controller3(FIG.5), and operations of the components of the box unpacking system other than the robot1are controlled by a system controlling device (not illustrated). The control of the operation of the robot1and the control of the box unpacking system are performed coordinatively with each other.

In this box unpacking system, a pallet31where a box aggregate32which is formed by suitably gathering cardboard boxes (hereinafter, simply referred to as “the box”)33is placed (disposed) (hereinafter, the pallet where the box aggregate32is placed is referred to as “the actual pallet”) is conveyed on the actual pallet conveyor52, and it is stopped at the depalletizing area51. Accommodated item(s) (product(s))36is accommodated inside the box33, and the box33is sealed (closed) by a tape34. When the actual pallet31is stopped, the robot1picks up the box33from the box aggregate32, opens the box33by using the cutting device40, and drops the accommodated item(s)36on the product taking-out conveyor55. Then, the product taking-out conveyor55conveys the accommodated item(s)36to the bag unpacking machine54, and the bag unpacking machine54opens a bag of the accommodated item(s)36and suitably processes the accommodated item. The robot1drops the empty box33on the empty box discharging conveyor56. Then, the empty box discharging conveyor56takes out the empty box33. When a series of box unpacking operations are repeated and the top of the pallet31becomes empty, the empty pallet31is conveyed to the pallet magazine53and the next actual pallet31is stopped at the depalletizing area51, by the actual pallet conveyor52. The empty pallets31are stacked on the pallet magazine53.

Next, the box unpacking device100is described in detail.

The robot1may have, at a wrist2a, a robot hand including a holding device10which holds a packed box33, and be capable of moving the box33held by the holding device10in a vertical plane. It is because, by the robot1moving the box33held by the holding device10upwardly in the vertical plane, a surface to be cut open can be pressed against a cutting blade41, and by moving the box33in an extending direction of the point of the cutting blade41in the vertical plane, the surface to be cut can be cut open. Here, “cutting open the surface of the box33” means that a cut line which can reach an interior space, or a linear opening is formed in the surface of the box33. The robot1may further change the angle of the box33held by the holding device10in a rotating direction in which the box33is made upside down. According to this configuration, since a lower surface of the box33held by the holding device10can be turned toward the cutting blade41, the lower surface of the box33can be cut open.

In this embodiment, the robot1can move the box33held by the holding device10in the vertical plane, and can change the angle of the box33held by the holding device10in the rotating direction in which the box is flipped upside down.

The robot1may be a vertical articulated robot, a horizontal articulated robot, a delta robot, a parallel link robot, or a robot dedicated for box unpacking.

The robot1includes a robot body2and a robot controller3(seeFIG.5).

Referring toFIG.3, the robot1is comprised of, for example, a 6-axis vertical articulated robots, and the robot body2is 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 device10(here, substantially, the robot hand is only comprised of the holding device10) is attached to the wrist2aof the robot body2.

The box33may be what can accommodate the accommodated item(s)36therein and can be sealed (closed), and can be cut open by the cutting blade41. The form of the box33is not limited in particular. Here, the box33is 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 box33is a cardboard box which is boxed (where item(s) is accommodated). Here, the shape of the box33is a rectangular parallelepiped, for example. The box33is comprised of a body part33aof a rectangular pillar shape comprised of four side walls of the rectangular parallelepiped, and flaps33bformed at an upper end and a lower end of each side wall of the body part33a. A top wall and a bottom wall are formed by bending and suitably combining the flaps33b, and closing both the end surfaces of the rectangular-pillar-shaped body part33a. Note that, in this embodiment, when not distinguishing the upward and downward directions of the box33in particular, the walls at both the ends of the rectangular-pillar-shaped body part33aare referred to as “the end wall(s).” Each end wall is sealed with an adhesive tape (hereinafter, simply referred to as “the tape”)34so that the flaps33bwill not open. Although the shape and the number of flap(s)33band the sealing mode by the tape34may be changed variously according to the form of the end walls of the box33, 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 part33ais used as a bendable part, and the end wall is formed by the flaps33bfor the pair of short sides having the same rectangular shape and the flaps33bfor 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 flaps33bfor 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 flaps33bfor the pair of long sides are abutted to each other. Then, the tape34pastes together the flaps33bfor the pair of long sides so that it covers the abutted part and straddles the flaps33bfor the pair of long sides. As a result, side edges of the flaps33bfor the long sides overlap with the bendable parts of the short sides of the body part33a. The tape34pastes together the flaps33bfor the long sides and the side walls of the box33so that it covers the overlapping part and straddles the flaps33bfor the long sides and the bendable parts of the short sides of the body part33a. Normally, the pasting of the side edges of the flaps22for the long sides and the short sides of the body part33ais performed at two locations of the body part33a. As a result, when the end wall is seen as a front view, the tape34forms 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 flaps22for the long sides and the short sides of the body part33amay be omitted. In this case, if the end wall is seen as the front view, the tape34forms the I-shape (hereinafter, this pasting mode of the tape34is 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 flap33b.The flap33boverlaps at its edge with a bottom edge of the side wall of the body part33a, and the tape34pastes together the flap33band the side wall of the body part33aso that it covers the overlapping part and straddles the flap33band the side wall of the body part33a.

Referring toFIG.3, the boxes33are stacked so as to form the box aggregate32on the pallet31. The box aggregate32may be the boxes33disposed regularly. The reason why the regularity is required is that it is necessary to identify the position of each box33on the pallet31in order for the robot1to hold the box33disposed on the pallet31.

In detail, for example, the box aggregate32is 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 boxes33placed 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 box33is placed so that its top surface becomes an upper surface.

Referring toFIG.2, the cutting device40is installed near the robot1. The cutting device40has the cutting blade41, of which the point is oriented downwardly. Note that the point of the cutting blade41may be oriented obliquely downwardly. The cutting blade41may have the point which is oriented downwardly or obliquely downwardly. The shape of the cutting blade41is not limited in particular, but it may be a disk, knife, or chain saw shape. The cutting blade41may be fixed or movable.

The cutting blade41is disposed at a position where the robot1is able to move the holding device10below the cutting blade41. This is because the robot1can press the box33held by the holding device10against the cutting blade41from below the cutting blade41, and can cut open the box33, if the cutting blade41is disposed in this way.

In detail, the cutting device40includes the cutting blade41of a disk shape, and a carrier42, for example. InFIG.2(andFIGS.8D-8Hand J), the carrier42is drawn transparently for convenience of description. The carrier42is 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 blade41is rotatably attached to the carrier42in a vertical plane through a horizontal rotation axis42a(seeFIG.8I). A lower end of the cutting blade41is exposed from the lower end of the carrier42. The cutting blade41is rotated by a motor (not illustrated), for example.

The accommodated item36(seeFIG.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.

Here, referring toFIGS.3and4, the holding device10includes a body part11, an attaching part12, a pair of gripper members13A and13B, a suction part18, and a three-dimensional (3D) position measuring instrument (box position detector)20. Note that, inFIG.4, illustration of the 3D position measuring instrument20is omitted. The 3D position measuring instrument20will be described later in detail. Moreover, inFIG.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 device10, respectively.

The body part11is 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, seeFIG.3).

The attaching part12of a cylindrical shape having a flange at a tip end is provided so as to stand upwardly from a center part of the body part11. The center axis of the attaching part12constitutes a reference axis AR of the holding device10. The holding device10is attached to the wrist2aof the robot body (robotic arm)2so that the reference axis AR becomes in agreement with the twist-rotation axis of the wrist2a. Moreover, as will be described later, the holding device10is positioned so that, by the robot body2, the body part11is located above the cardboard box33and the reference axis AR is substantially in agreement with the center axis of the cardboard box33.

FIG.4illustrates the holding device10in a posture where the reference axis AR extends in the up-and-down direction (vertically).

The pair of gripper members13A and13B are attached to the body part11so 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 members13A and13B are attached to the body part11so as to be rotatable on a pair of rotation axes A1and A2perpendicular to the extending direction of the reference axis AR and the given direction. The parts of the body part11to which the base-end parts of the pair of gripper members13A and13B are attached, respectively, are separated from the reference axis AR of the body part11by an equal distance in the given direction. The pair of gripper members13A and13B are driven by a pneumatic controlling circuit (not illustrated). In the drawings other thanFIGS.4and8I, the pair of gripper members13A and13B are illustrated by one reference character “13” for simplification.

The pair of gripper members13A and13B are formed, for example, when seen in the extending directions of the respective rotation axes A1and A2, in a plate shape having a cross-sectional shape bent in a direction or to the side in which the pair of gripper members13A and13B approach each other (hereinafter, referred to as inward or the inside).

Pawls15A and15B which protrude inwardly are provided at tip ends of the pair of gripper members13A and13B, respectively. Moreover, friction members17A and17B are attached to parts of inner surfaces of the pair of gripper members13A and13B, on the tip-end sides from the bent parts, respectively. The pair of friction members17A and17B may be members with a large friction coefficient, and the pair of friction members17A and17B may be members made of rubber, sponge, or sandpaper.

The length and the bending degree of the pair of gripper members13A and13B are set (designed) so that, in a state where the body part11is located above the cardboard box33(in detail, in a state where the suction part18sucks a center part of the upper surface of the cardboard box33), for example, the pair of pawls15A and15B may be stuck into upper parts of the left-and-right side walls of the cardboard box33, respectively, and the pair of friction members17A and17B contact the upper parts of the left-and-right side walls of the cardboard box33, respectively.

However, depending on the state of the accommodated item(s)36(for example, when the number of accommodated items36is small), the length and the bending degree of the pair of gripper members13A and13B may be set (designed) so that, in a state where the body part11is located above the cardboard box33(in detail, in a state where the suction part18sucks the center part of the upper surface of the cardboard box33), the pair of pawls15A and15B are stuck into a part of any one of the left-and-right side walls of the cardboard box33, and the pair of friction members17A and17B contact a part of any one of the left-and-right side walls of the cardboard box33.

The suction part18is provided to a lower surface of the body part11. The suction part18is comprised of a vacuum suction pad, for example. The suction part18is provided, for example, so that the center axis is in agreement with the reference axis AR. The suction part18performs sucking/releasing operation by the pneumatic controlling circuit described above.

As illustrated inFIG.3, the 3D position measuring instrument20as the box position detector is provided to a side part of the body part11of the holding device10. The 3D position measuring instrument20measures a three-dimensional position of the box33. The 3D position measuring instrument20may be comprised of a three-dimensional vision camera, an image sensor, or an ultrasonic distance sensor, for example. Here, the 3D position measuring instrument20is comprised of the three-dimensional vision camera.

{Configuration of Control System}

FIG.5is a block diagram illustrating a configuration of a control system of the box unpacking device100ofFIG.1.

Referring toFIG.5, the robot controller3is comprised of a sole controller which performs a centralized control or a plurality of controllers which perform a distributed control. Here, the robot controller3is comprised of the sole controller which performs the centralized control. The installed location of the robot controller3is not limited in particular. The robot controller3is installed at a base part (seeFIG.2) of the robot body2, for example. The robot controller3is provided with a processor Pr and a memory Me, for example. The robot controller3controls operations of the robot body2and the holding device10by the processor Pr reading and executing a given control program stored in the memory Me. In detail, the robot controller3is 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 controller3controls the motor which drives each joint of the robot body2to control operation of the robot body2, and controls the pneumatic controlling circuit of the holding device10to control operation of the holding device10. Moreover, the robot controller3identifies the 3D position of the box33based on measurement data of the 3D position measuring instrument20. Then, the robot controller controls the operations of the robot body2and the holding device10so as to hold the box33based on the identified 3D position of the box33, and makes the robot body2and the holding device10perform the box unpacking operation according to the given control program described above.

The cutting device40is suitably controlled by the system controlling device (not illustrated) described above. Note that the robot controller3may control the operation of the cutting device40.

Next, operation of the box unpacking device100configured as described above is described. First, an outline of the operation of the box unpacking device100is described usingFIGS.2,3, and6.

FIG.6is a flowchart illustrating the outline of the box unpacking operation by the box unpacking device ofFIG.1. The operations of the robot1and the holding device10are carried out by the control of the robot controller3.

Referring toFIGS.2,3, and6, the robot1holds the box33by using the holding device10(Step S1).

Next, the robot1moves the box33to the cutting device40(Step S2).

Then, the robot1unpacks the box33by using the cutting blade41of the cutting device40(Step S3).

Next, operation of the box unpacking device100is described in detail usingFIGS.2-4,7, and8A-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 body2holds surfaces other than the bottom surface of the box33(the upper surface and the side surface) by positioning the wrist2aabove the box33, is illustrated. Note that the cutting blade41is rotating.

First, as illustrated inFIG.3, the robot1measures, by using the 3D position measuring instrument20, the 3D position of one of the plurality of boxes33which constitute the box aggregate32on the pallet31, of which the top surface is exposed and which is located at the given position. Although the box33of 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 box33includes an error originating from the position error of the pallet31, the arrangement error of the box33when forming the box aggregate32, etc., it is corrected to a 3D position which is obtained by measuring the error (Step S1-1). Particularly, in the box unpacking device100, since the box33is griped by the pair of gripper members13A and13B of the holding device10, it is important for the 3D position of the box33to be exact in order to grip the box33correctly.

Next, as illustrated inFIG.8A, the robot1sucks the top surface of the designated box33by using the suction part18(seeFIG.4) (Step S1-2).

Next, as illustrated inFIG.8B, the robot1lifts the sucked box33to a given gripping position (Step S1-3).

Then, as illustrated inFIG.8C, the robot1grips the upper part of the box by the pair of gripper members13A and13B (13) (Step S1-4). Therefore, the box33is held firmly by the robot1, and it becomes possible to convey (move) the box33.

Next, as illustrated inFIG.8D, the robot1moves the held box33to in front of the cutting blade41of the cutting device40(Step S2). In detail, the robot1changes the angle of the box33in the rotating direction in which the box is flipped upside down when holding the box33to change the posture of the box33so that the top surface of the held box33is turned obliquely upward. By this posture change, the accommodated item(s)36(seeFIG.81) inside the box33is brought closer to a lower part of the box33. This forms a gap in an upper part of the interior space of the box33. Since the gap is formed in the upper part of the interior space of the box33, even when the cutting blade41relatively moves with respect to the box33while the point is stuck into the box, the cutting blade41will not damage the accommodated item(s) inside the box33. Then, the robot1positions an end (a right end inFIG.8D) of one of the short sides of the box33at the left side of a bottom end part of the cutting blade41.

Then, the robot1moves the box33horizontally to the right side inFIG.8Dalong an extending surface of the cutting blade41.

Therefore, as illustrated inFIG.8E, one side of the tape34at the bottom side of the box33is cut in the transverse direction (Step S3-1). Note that, in the case of the H-shaped tape pasting mode, the tape corresponding to one of the short sides of the box33is also cut. Moreover, the cutting operation described above is carried out by moving the box33in a vertical plane including the extending surface of the point of the cutting blade41.

Next, as illustrated inFIG.8F-8G, the robot1rotates the box33by180degrees on the center axis of the wrist2a(the reference axis AR of the holding device10), and then cuts the other side of the tape34at the bottom side of the box33in the transverse direction, similarly to Step S3-1(Step S3-2). Note that, in the case of the H-shaped tape pasting mode, the tape corresponding to the other short side of the box33is also cut.

Then, as illustrated inFIG.8H, the robot1turns the box33vertically upward by rotating the box33by 90 degrees on the center axis of the wrist2a, and positions the center of one side of the short sides (right side inFIG.8H) of the box33, at the left side of the bottom end of the cutting blade41.

Then, the robot1moves the box33horizontally to the right side inFIG.8Halong the extending surface of the cutting blade41. At this time, as illustrated inFIG.81, since the accommodated item(s)36inside the box33is brought closer to the lower part of the box33and the gap is formed in the upper part of the interior space of the box33, the cutting blade41will not damage the accommodated item(s) inside the box33.

Therefore, as illustrated inFIG.8J, the part located in the bottom surface of the tape34at the bottom side of the box33is cut in the longitudinal direction (Step S3-3). Note that, in the case of the H-shaped tape pasting mode, the part located in the bottom surface of the tape34at the bottom side of the box33is similarly cut in the longitudinal direction. Moreover, the cutting operation at Step S3-3is also carried out by moving the box33in the vertical plane including the extending surface of the point of the cutting blade41.

As a result, the sealed state of the bottom wall of the box33is canceled by cutting all the tapes34pasted on the flaps33b.

Next, the robot1moves the box33onto the product taking-out conveyor55which is an accommodated item table (Step S4).

Then, as illustrated inFIGS.8K and8L, the robot1twists the box33so that the accommodated item(s)36is discharged from the box33onto the product taking-out conveyor55, while pushing away the flaps33b(Step S5).

In this case, the box33may be twisted so as to become sideways, or may be twisted so as to stand upright. Alternatively, the posture of the box33may be changed in modes other than twisting.

Therefore, as illustrated inFIG.8M, the accommodated items36accommodated inside the box33fall altogether onto the product taking-out conveyor55and are discharged (Step S6).

Next, as illustrated inFIG.8N, the robot1moves the empty box33onto the empty box discharging conveyor56(Step S7).

Next, as illustrated inFIG.8O, the robot1releases the box33by canceling the suction by the suction part18of the holding device10and canceling the gripping by the pair of gripper members13. Then, the empty box33falls onto the empty box discharging conveyor56(Step S8). The fallen empty box33is taken out by the empty box discharging conveyor56.

Then, the robot1repeats the operation described above.

According to such an embodiment, the robot1can change the angle of the box33held by the holding device10in the rotating direction in which the box is flipped upside down so that the surface of the box33to be cut open is turned to be perpendicular to the cutting blade41, and can move the box33upward in the vertical plane to press the surface to be cut open against the cutting blade41, and can move the box33in the extending direction of the cutting blade41in the vertical plane to cut open the surface to be cut open.

Therefore, the box33can be unpacked while dealing with the various sizes of the box33and various seal types. In addition, since the surface to be cut open is oriented upwardly when it is cut open, the accommodated item(s)36inside the box33is brought closer to the lower part by its own weight, thereby reducing the possibility of the damage to the accommodated item(s)36by the cutting blade41.

FIG.9is a view illustrating another mode of the depalletizing operation. Referring toFIG.9, in Modification 1 of this embodiment, a plurality of boxes33are serially disposed on the pallet31, as the box aggregate32. The number of rows is not limited in particular. Such a case may be that the box33is vertically elongated, and when the boxes33are stacked, the box aggregate32becomes unstable, for example.

In this modification, the box33at the front end of the box row of the box aggregate32is the box located at the given position. At each point in time, the robot body2holds the surfaces other than the lower surface of the box33(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 wrist2ais located forward (sideways) of the box33.

Other matters are completely the same as the above embodiment.

According to Modification 1, when the box33located at the given position is disposed so that the side surface of the box33is able to be held, the box33located at the given position can be held easily, and the lower surface of the box33can be cut open.

Modification 2 is similar to the modification1other than followings.

In Modification 2, the robot body2holds the box33by using the holding device10similar to Modification 1, and then opens the box33without flipping the box33upside down. In detail, at Steps S3-1to S3-3of the flowchart inFIG.7, the tape34at the top side of the box33is cut.

According to Modification 2, the upper surface in the arrangement state of the box33can be cut open. When the up-and-down direction does not exist in the accommodated item(s)36, the opened box33is further flipped upside down to drop the accommodated item(s)36, so that the accommodated item(s)36can be taken out from the box33.

Other Embodiments

In the above embodiment, Modification 1, and Modification 2 (hereinafter, they are simply referred to as “the above embodiment”), the box unpacking device100may be provided with a manipulator for manipulating the robot1, and unpack the box33by an operator manipulating the robot1using the manipulator. In this case, for example, the box unpacking device100may be configured so that the operator operates the robot body2and the holding device10without an intervention of the control device. Moreover, for example, a manipulation signal may be inputted into the robot controller3by the manipulation of the manipulator, and the box unpacking device100may be configured so that the robot controller3controls the operations of the robot body2and the holding device10according to the manipulation signal.

In the above embodiment, the box33may not be sealed by the tape34. For example, the box33may be sealed by engaging the flaps with each other, or pasting the flaps together. Alternatively, the box33may 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 part18) and a pair of side wall holding parts (gripper members13A and13B), either one may be provided.

Moreover, although in the above embodiment the cardboard boxes33are stacked, the placing mode of the cardboard boxes33is 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 part18) may be omitted.

Moreover, the direction in which the holding device10holds the cardboard box33is not limited in particular. For example, when the cardboard box33is placed so that the top wall is oriented sideways or downwardly, the holding device10may hold the cardboard box33from the side or below. In short, the holding device10may hold the cardboard box33so that the body part11becomes adjacent to the end wall of the cardboard box33at the opposite side of the end wall to be cut open.

Moreover, the box holding part (18,13) may hold the cardboard box33by supporting the part of the cardboard box33other 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 box33.

Although in the above embodiment the suction part18is 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 box33. For example, the upper wall holding part may be provided with a pawl which can stick into the upper wall and support the cardboard box33.

Although in the above embodiment the side wall holding part is comprised of the pair of gripper members13A and13B, the side wall holding part may support the side wall and hold the cardboard box33. 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 member13of the holding device10is driven by the pneumatic controlling circuit, the power source of the gripper member13is not limited to this configuration. For example, the gripper member13may be driven by a motor.

Moreover, in the above embodiment, the cutting device40may have a plurality of cutting blades41.

Moreover, in the above embodiment, the 3D position measuring instrument20may 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