Patent Publication Number: US-2022219922-A1

Title: Unloading apparatus and unloading method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation Application of PCT Application No. PCT/JP2020/039736, filed Oct. 22, 2020 and based upon and claiming the benefit of priority from prior Japanese Patent Application No. 2019-194592, filed Oct. 25, 2019, the entire contents of all of which are incorporated herein by reference. 
    
    
     FIELD 
     Embodiments described herein relate generally to a package unloading apparatus and a package unloading method. 
     BACKGROUND 
     An unloading apparatus that unloads a package loaded on a mount portion such as a pallet is known. The unloading apparatus unloads the package by holding any one of side surfaces and an upper surface of the package and moving the package to a predetermined position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic perspective view showing an unloading apparatus according to an embodiment. 
         FIG. 2  is a schematic view showing a first moving mechanism, a support portion (rotation portion), a second moving mechanism, and a grip portion of the unloading apparatus according to the embodiment. 
         FIG. 3  is a schematic block diagram of the unloading apparatus according to the embodiment. 
         FIG. 4  is a flowchart showing an example of an operation of the unloading apparatus according to the embodiment. 
         FIG. 5  is a schematic view describing an example of the operation of the unloading apparatus according to the embodiment. 
         FIG. 6  is a schematic view describing an example of the operation of the unloading apparatus according to the embodiment. 
         FIG. 7  is a schematic view describing an example of the operation of the unloading apparatus according to the embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     A problem to be solved by one embodiment is to provide an unloading apparatus and an unloading method capable of unloading a package more efficiently. 
     According to one embodiment, an unloading apparatus includes a first sucking portion, a second sucking portion, a first moving device, a rotation portion, and a processor. The first sucking portion is configured to suck an upper surface of a package. The second sucking portion is configured to suck a side surface of the package. The first moving device is configured to move the first sucking portion and the second sucking portion. The rotation portion rotatably connects the first sucking portion and the second sucking portion to the first moving device. The processor is configured to control the first moving device. The processor is configured to control the first moving device to move the first moving device upward along a direction intersecting the side surface of the package sucked by the second sucking portion or a surface obtained by virtually extending the side surface in a state in which the upper surface of the package is sucked by the first sucking portion and the side surface of the package is sucked by the second sucking portion. The processor thereafter is configured to control the first moving device to move the first moving device to a position where the package is to be placed in the state. 
     Various Embodiments will be described hereinafter with reference to the accompanying drawings. 
     An unloading apparatus  12  according to an embodiment will be described using  FIGS. 1 to 7 . 
       FIG. 1  is a view schematically showing an example of the unloading apparatus  12 .  FIG. 2  is a view schematically showing a first moving device  24 , a support portion (rotation portion)  26 , a second moving device  28 , and a grip portion  30  of the unloading apparatus  12 .  FIG. 3  is a schematic block diagram of the unloading apparatus  12 .  FIG. 4  is a flowchart showing an example of an operation of the unloading apparatus  12 .  FIGS. 5 to 7  are explanatory views describing a series of operations from gripping to lifting, for example, a selected package P from a mount portion  8  using the unloading apparatus  12 . 
     The unloading apparatus  12  shown in  FIG. 1  takes out and unloads the package P one by one or a plurality of packages P simultaneously from the mount portion  8  such as a table on which the plurality of packages P are placed, and carries out the unloaded packages P to a main conveyor  14 . 
     The unloading apparatus  12  includes a frame  22 , the first moving device  24 , the support portion (rotation portion)  26 , the second moving device  28 , and the grip portion  30 . The unloading apparatus  12  further includes an intermediate conveyor portion  32 , a lifting and lowering portion (an intermediate conveyor portion lifting and lowering portion)  34 , a first sensor  36 , and a second sensor  38 . 
     The unloading apparatus  12  is an apparatus that grips each package P of a package group B loaded on the mount portion  8  arranged in the vicinity of the unloading apparatus  12 , unloads the package P onto the intermediate conveyor portion  32 , and carries out the package P from the intermediate conveyor portion  32  to the main conveyor  14 . 
     Here, the loaded package group B refers to one or a plurality of stages stacked including a plurality of packages P that are, for example, substantially rectangular parallelepipeds. 
     In  FIG. 1 , as an example, the package group B includes packages P stacked in three stages. The package group B includes three stages, an uppermost stage Us, a middle stage Ms, and a lowermost stage Ls. Each of the uppermost stage Us, the middle stage Ms, and the lowermost stage Ls includes a plurality of packages P. There is a case where the package P in the uppermost stage Us is indicated by a reference sign P 1 . There is a case where the package P in the middle stage Ms is indicated by a reference sign P 2 . There is a case where the package P in the lowermost stage Ls is indicated by a reference sign P 3 . The upper surface of each package P is indicated by a reference sign Pa, the side surface is indicated by a reference sign Pb, and the bottom surface is indicated by a reference sign Pc. 
     For example, the heights of the packages P 1  included in the uppermost stage Us may be the same as or different from each other. The same applies to the packages P 2  included in the middle stage Ms and the packages P 3  included in the lowermost stage Ls. The packages P included in the same stage may have different vertical lengths (depth) and horizontal lengths (width). The orientations of the packages P included in the same stage may be the same, or may be different as long as the side surfaces of the plurality of packages P face each other. For example, in  FIG. 1 , each of the stages Us, Ms, and Ls of the package group B includes a plurality of packages P having different orientations. The mount portion  8  of the loaded package group B is not limited to a flat pallet, and the package group may be accommodated in a cage-like pallet with a caster, a roll box pallet (RBP), or the like. 
     One or a plurality of packages P may be placed directly on the mount portion  8 , or an appropriate sheet may be arranged so that one or a plurality of packages P are placed indirectly on the sheet. In a present embodiment, placing the package P on the mount portion  8  includes both directly and indirectly placing the package P on the mount portion  8 . 
     As in an example shown in  FIG. 2 , for example, in order to prevent the occurrence of package collapse during transportation in a truck, an appropriate anti-slip treatment agent S such as a glue may be attached between the bottom surface Pc of the package P 1  and the upper surface Pa of the lower package P 2  on the upper and lower sides, and between the bottom surface Pc of the package P 2  and the upper surface Pa of the package P 3 . The anti-slip treatment agent S prevents or suppresses horizontal slip between the bottom surface Pc of the package P 1  and the upper surface Pa of the package P 2 . With the anti-slip treatment agent S, when the package P 1  on the upper side is lifted upward, frictional force and adhesive force that prevent the package P 2  on the lower side from being lifted together may act between the upper and lower packages P 1  and P 2 . In this manner, the upper and lower packages P 1  and P 2  and the packages P 2  and P 3  are in a light adhesion state due to the anti-slip treatment agent S. 
     Adhesive force between the upper and lower packages P 1  and P 2  and the packages P 2  and P 3  due to the anti-slip treatment agent S largely varies. Therefore, when the package P 1  on the upper side is lifted upward, the package P 2  on the lower side may be lifted together, and a load may be applied to the exterior of the package P 2  on the lower side. 
     In addition, when the package P is unloaded from the package group B on the mount portion  8 , the upper and lower packages P 1  and P 2  may be dragged together without being separated due to friction caused by the anti-slip treatment agent S, which may collapse the stage. 
     The anti-slip treatment agent S is not attached between the packages P on the front and rear sides and the left and right sides in the same stage. That is, the anti-slip treatment agent S is not attached to the side surface of the package P. Therefore, the slip between the upper and lower packages P 1  and P 2  and the slip between the upper and lower packages P 2  and P 3  are prevented by the anti-slip treatment agent S. 
     The anti-slip treatment agent S may be attached in a dotted or linear shape between the bottom surface Pc of the package P 1  and the upper surface Pa of the package P 2 , or may be attached in a planar shape so as to have an appropriate area. Similarly, the anti-slip treatment agent S may be attached in a dotted or linear shape between the bottom surface Pc of the package P 2  and the upper surface Pa of the package P 3 , or may be attached in a planar shape so as to have an appropriate area. An example of the package P is a cardboard box enclosing a plurality of plastic bottles. 
     As shown in  FIG. 1 , the frame  22  includes, for example, a frame body  52  and a protrusion portion  54 . 
     As shown in  FIGS. 1 and 2 , an XYZ coordinate system is set. An X-axis direction is an arrangement direction of the mount portion  8  with respect to the frame  22  and an arrangement direction of the main conveyor  14  with respect to the frame  22 . As an example, the X-axis direction is a moving direction (front-rear direction) of the package P when the package P is taken out from the package group B on the mount portion  8 . A Y-axis direction is a width direction (left-right direction). A Z-axis direction is an up-down direction. 
     As shown in  FIG. 1 , the frame body  52  includes, for example, four pillar portions  52   a  extending in the Z-axis direction, and a plurality of beam portions  52   b  provided at upper and lower ends of the four pillar portions  52   a  and extending in the X-axis direction and the Y-axis direction. The frame body  52  has a front opening  56   a  and a rear opening  56   b  in the front-rear direction. One or a plurality of packages P are grasped from the mount portion  8  outside the frame body  52 , placed on the intermediate conveyor portion  32  in the frame body  52  through the front opening  56   a , and carried out to the main conveyor  14  outside the frame body  52  through the rear opening  56   b.    
     The protrusion portion  54  is arranged above the position where the mount portion  8  is disposed. A first sensor  36  that detects information related to the package P is installed to the protrusion portion  54 . That is, the first sensor  36  is installed to the frame  22  and is arranged above a position where the package group B on the mount portion  8  is disposed. 
     The first sensor  36  is, for example, a stereo camera. The stereo camera measures a distance between the camera and each package P of the package group B based on parallax when images are captured from two different points. The first sensor  36  photographs the package group B loaded on the mount portion  8 , and detects the position, size, and shape of each package P of the package group B. Therefore, the first sensor  36  detects information related to the package P including position information of the package P. 
     A second sensor  38  measures a distance between the second sensor  38  and the package P. The second sensor  38  is provided between the package group B loaded on the mount portion  8  and the intermediate conveyor portion  32  in the X-axis direction. The second sensor  38  is installed to the bottom frame of the beam portion  52   b  of the frame body  52  of the frame  22 , for example. 
     The second sensor  38  is, for example, a laser range finder (LRF). The LRF is, for example, an optical instrument that oscillates an infrared laser from a measurement position where the second sensor  38  is installed to emit laser light, and measures a distance to the package P based on the time from the emission of the laser light to the reception of reflected light by the package P grasped by the grip portion  30 . The second sensor  38  measures the height of the bottom surface Pc of the package P by measuring the distance to the bottom surface Pc of the package P on the movement locus of the package P grasped by the grip portion  30  and moved by the grip portion  30  to the intermediate conveyor portion  32 . The laser light is not limited to infrared laser light, and may be laser light of a visible light beam, ultraviolet light beam, X-ray, and the like. 
     Then, the height of each package P can be calculated from the information of the distance to the upper surface Pa of the package P acquired by the first sensor  36  and the distance to the bottom surface Pc of the package P by the second sensor  38 . 
     The main conveyor  14  is provided on the side opposite to the position where the first sensor  36  and the second sensor  38  are located along the X axis with respect to the frame  22 . The conveying direction of the main conveyor  14  is, for example, the Y-axis direction. 
     As shown in  FIG. 2 , the first moving device  24  is supported by the frame body  52  of the frame  22 . 
     The first moving device  24  includes a lifting and lowering mechanism  62  that moves in the Z-axis direction, a horizontal moving device  64  that moves in the X-axis direction and the Y-axis direction, and a connecting portion (rotation assisting portion)  66  that connects the horizontal moving device  64  and the support portion  26 . 
     The lifting and lowering mechanism  62  includes, for example, a shaft  72  that extends in the Y-axis direction and is supported by the beam portion  52   b  at the upper end of the frame body  52 , a Z-axis actuator  74  that is supported by one end of the shaft  72  and rotates the shaft  72 , and a plurality of wires  76  wound around the shaft  72 . The shaft  72  may extend not in the Y-axis direction but in the X-axis direction. When the Z-axis actuator  74  is driven, the shaft  72  rotates. When the shaft  72  rotates, the horizontal moving device  64  supported by the wires  76  is lifted and lowered. 
     The lifting and lowering mechanism  62  is simply required to be configured to lift and lower the horizontal moving device  64 , and is not limited to the above-described configuration. For example, the horizontal moving device  64  may be lifted and lowered by directly supporting the wires  76  using a linear motor (Z-axis actuator) or the like, instead of rotating the shaft  72 . 
     The horizontal moving device  64  includes, for example, a base  82  supported by the wires  76 , an arm  84  extending in the X-axis direction, and a movable portion  86  movably supporting the arm  84 . The arm  84  can be moved by the movable portion  86  in the X-axis direction with respect to the base  82 . The arm  84  can be moved by the movable portion  86  in the Y-axis direction with respect to the base  82 . The movable portion  86  includes an X-axis actuator  86   a  and a Y-axis actuator  86   b  (see  FIG. 3 ). 
     The first moving device  24  according to the present embodiment includes an orthogonal robot arm that linearly moves in three axial directions shown in  FIG. 1 , that is, the X-axis direction (front-rear direction), the Y-axis direction (left-right direction), and the Z-axis direction (height direction). The first moving device  24  can move the arm  84  independently in the X-axis direction, the Y-axis direction, and the Z-axis direction in response to the control of the grip portion  30  by a controller  200  to be described later. That is, the operation of the first moving device  24  is controlled by the controller  200 . The first moving device  24  moves the grip portion  30  to a position where the package P of the package group B is grasped, and places the package P grasped by the grip portion  30  on the intermediate conveyor portion  32 , for example, by moving the arm  84  in the X-axis direction, the Y-axis direction, and the Z-axis direction. 
     The support portion  26  is supported by the end or the area near the end of the arm  84  of the horizontal moving device  64 . The support portion  26  supports the grip portion  30 . The support portion  26  is provided on the side opposite to the main conveyor  14  along the X-axis direction of the first moving device  24 . The support portion  26  integrally moves with the movement of the arm  84  of the horizontal moving device  64  in the X-axis direction, the Y-axis direction, and the Z-axis direction. A part or whole of the support portion  26  can be moved by the first moving device  24  between a position where the support portion is arranged in the space inside the frame body  52  of the frame  22  and a position where the support portion is arranged below the protrusion portion  54  outside the frame body  52  of the frame  22  through the front opening  56   a  of the frame body  52 . 
     The support portion  26  includes a base portion  122  and a rotation shaft  124  supporting the base portion  122  on the arm  84  of the horizontal moving device  64  of the first moving device  24 . 
     The base portion  122  has, for example, a substantially L shape. The base portion  122  includes an arm  122   a  configured in a rod shape extending in one direction, and an extension portion  122   b  extending from one end in the longitudinal direction of the arm  122   a  in a direction orthogonal to the longitudinal direction of the arm  122   a . It is preferable that the arm  122   a  and the extension portion  122   b  are integrally formed, and the angle between the extending direction of the arm  122   a  and the extending direction of the extension portion  122   b  is invariable. 
     As shown in  FIG. 2 , the base portion  122  configured as described above is supported by the arm  84  of the first moving device  24  so as to be rotatable by the rotation shaft  124  that is parallel to the Y-axis direction, at the boundary between the arm  122   a  and the extension portion  122   b . That is, the support portion  26  is rotatable by the rotation shaft  124  in the Y-axis direction, with respect to the horizontal moving device  64 . 
     At the initial position, the arm  122   a  and the extension portion  122   b  have a positional relationship that allows the arm  122   a  to be parallel to the X-axis direction (front-rear direction) and the extension portion  122   b  to take a posture extending downward along the Z-axis direction. The end surface of the arm  122   a  on the main conveyor  14  side, which is the rotation shaft  124  side, is configured as, for example, a curved surface  122   c  that allows the arm  122   a  of the support portion  26  to rotate within an appropriate range with respect to the arm  84  of the horizontal moving device  64 . The maximum rotation amount of the base portion  122  (the arm  122   a  and the extension portion  122   b ) of the support portion  26  with respect to the arm  84  of the horizontal moving device  64  may be defined by an appropriate stopper. 
     The base portion  122  is configured to be rotatable by a predetermined angle from the initial position in a state in which an upper surface sucking portion (upper surface holding portion)  142  and a side surface sucking portion (side surface holding portion)  144  of the grip portion  30  do not grip or hold the package P. The predetermined angle is an angle at which the grip portion  30  does not come into contact with the first moving device  24  when the base portion  122  of the support portion  26  rotates about the rotation shaft  124  due to the action of a rotation actuator  134  to be described later and the weight of the package P. In the present embodiment, the predetermined angle is, for example, 10 degrees to 15 degrees. The maximum rotation angle of the base portion  122  may be the same as or larger than the predetermined angle. 
     The second moving device  28  is supported by the support portion (rotation portion)  26 . The second moving device (front-rear moving device)  28  is supported on the extension portion  122   b  of the base portion  122  of the support portion  26 . The second moving device  28  is supported below the base portion  122  of the support portion  26  and is used to move the side surface sucking portion  144  to be described later in the front-rear direction. The operation of the second moving device  28  is controlled by the controller  200 . The second moving device  28  includes a base portion  126   a  fixed to, for example, the extension portion  122   b  of the base portion  122 , a moving portion  126   b  connected to the base portion  126   a  so as to be movable in the X axis direction, and a driving portion  126   c  for the moving portion  126   b . The driving portion  126   c  is fixed to the base portion  126   a , for example. The side surface sucking portion  144  to be described later of the grip portion  30  is supported on, for example, the end of the moving portion  126   b  in the moving direction. The position where the moving portion  126   b  is farthest from the upper surface sucking portion  142  in the front-rear direction is defined as the initial position. 
     When the driving portion  126   c  is driven to move the moving portion  126   b , the side surface sucking portion  144  moves. The driving portion  126   c  is, for example, a motor. The second moving device  28  configured as described above is fixed to the base portion  122  in a posture in which the moving direction of the moving portion  126   b  is parallel to the front-rear direction when the base portion  122  is at the initial position. 
     The connecting portion  66  includes, for example, an arm  132  extending forward along the X-axis direction from above the arm  84  of the horizontal moving device  64 , and the rotation actuator  134  supported by the arm  132 . For example, an air cylinder is used as the rotation actuator  134 . The rotation actuator  134  includes a cylinder  134   a  and a piston  134   b  that can be taken in to and out from the cylinder  134   a  by air supplied from an appropriate pump. For example, the cylinder  134   a  is supported by the arm  132 . A protrusion end  134   c  of the piston  134   b  is supported by the arm  122   a  of the base portion  122  of the support portion  26  through a shaft member  136   a  of a rotation metal fitting  136 . 
     By adjusting the protrusion amount of the protrusion end  134   c  of the piston  134   b  with respect to the cylinder  134   a  of the rotation actuator  134 , the rotation amount of the support portion  26  about the axis of the rotation shaft  124  with respect to the horizontal moving device  64  is adjusted. Therefore, the unloading apparatus  12  can actively move the support portion  26  with respect to the horizontal moving device  64  using the rotation actuator  134 . 
     At the initial position (fixed position) shown in  FIG. 2  in which the piston  134   b  is pulled into the cylinder  134   a , the protrusion amount of the protrusion end  134   c  of the piston  134   b  with respect to the cylinder  134   a  of the rotation actuator  134  is defined as D 0 . From the initial position, at the rotation position shown in  FIGS. 6 and 7  in which the piston  134   b  is pushed out from the cylinder  134   a , the protrusion amount of the protrusion end  134   c  of the piston  134   b  with respect to the cylinder  134   a  of the rotation actuator  134  is defined as D 1 . 
     By adjusting the protrusion amount (position) of the protrusion end  134   c  of the piston  134   b  of the rotation actuator  134 , the arm  122   a  of the base portion  122  is maintained at the initial position parallel to the front-rear direction in a state in which the package P is not grasped by the grip portion  30 . In a state in which the package P is grasped by the grip portion  30 , the support portion  26  rotates about the axis of the rotation shaft  124 , and the arm  122   a  of the base portion  122  shifts to an inclined position inclined in the front-rear direction. 
     The weights of the base portion  122  of the support portion  26 , the second moving device  28 , the grip portion  30 , and further the package P are applied to the rotation actuator  134 . The piston  134   b  of the rotation actuator  134  can be pushed out from and pulled into the cylinder  134   a  in a state in which the above-described weight is applied thereto. It is preferable that the piston  134   b  can adjust the pushing speed and/or the pulling speed with respect to the cylinder  134   a  in a state in which the above-described weight is applied. 
     In the present embodiment, when the package is appropriately grasped by the grip portion  30  and the protrusion amount of the piston  134   b  with respect to the cylinder  134   a  is shifted from D 0  to D 1 , free rotation is performed due to the weights of the support portion  26 , the second moving device  28 , the grip portion  30 , and the package P. That is, the rotation actuator  134  uses a single-acting air cylinder as an example. At this time, the rotation actuator  134  is used as a damper to slowly rotate the base portion  122  of the support portion  26 . When the protrusion amount of the piston  134   b  with respect to the cylinder  134   a  is shifted from D 1  to D 0 , the support portion  26  is moved to the initial position (fixed position) at an appropriate speed against the weights of the support portion  26 , the second moving device  28 , and the grip portion  30 . 
     In  FIG. 2 , the cylinder  134   a  is arranged on the arm  132  of the connecting portion  66 , and the piston  134   b  is connected to the arm  122   a  of the base portion  122  of the support portion  26  via the rotation metal fitting  136 . The cylinder  134   a  may be connected to the arm  122   a  of the base portion  122  of the support portion  26 , and the piston  134   b  may be connected to the arm  132  of the connecting portion  66 . 
     As the rotation actuator  134 , an electric cylinder or the like may be used in addition to the air cylinder. 
     In the present embodiment, an example that uses the air cylinder as the rotation actuator  134  supported on the arm  132  of the connecting portion  66  of the first moving device  24  will be described. The arm  132  of the connecting portion  66  may be rotated about an axis (Y axis) parallel to the rotation shaft  124  with respect to the arm  84  of the horizontal moving device  64 . At this time, an appropriate motor can be used as a rotation actuator for rotating the arm  132  of the connecting portion  66 . 
     The grip portion  30  grips the package P of the package group B and releases grip. The grip portion  30  includes, for example, the upper surface sucking portion (first sucking portion)  142  that is supported by the arm  122   a  of the support portion  26  and sucks the upper surface Pa of the package P, and the side surface sucking portion (second sucking portion)  144  that is supported by the moving portion  126   b  of the second moving device  28  and sucks the side surface Pb of the package P on the frame body  52  side. The upper surface sucking portion  142  faces downward at the initial position. The side surface sucking portion  144  faces a direction away from the frame  22  (far side) at the initial position. The directions in which the upper surface sucking portion  142  and the side surface sucking portion  144  face can be changed due to the rotation of the support portion  26 . The upper surface sucking portion  142  and the side surface sucking portion  144  are fixed at a predetermined angle. The predetermined angle is, for example, 90 degrees. Therefore, the grip portion  30  can grip the package P by sucking the upper surface Pa of the package P using the upper surface sucking portion  142  and sucking the side surface Pb of the package P using the side surface sucking portion  144 . 
     The upper surface sucking portion  142  includes a first body (block body)  142   a  having a substantially rectangular parallelepiped shape, and a plurality of first suction pads (upper surface sucking portion)  142   b  supported by the first body  142   a . The first suction pads  142   b  face downward. The first suction pads  142   b  are connected to, for example, a negative pressure generating portion  40  (see  FIG. 3 ) controlled by the controller  200 . Therefore, the upper surface sucking portion  142  grips the upper surface Pa of the package P by means of suction. 
     The side surface sucking portion  144  includes a second body (block body)  144   a  having a substantially rectangular parallelepiped shape, and a plurality of second suction pads (side surface sucking portion)  144   b  supported by the second body  144   a . The second body  144   a  is supported by, for example, the moving portion  126   b  of the second moving device  28 . The second suction pads  144   b  face a direction away from the frame  22 . The second suction pads  144   b  are connected to, for example, a negative pressure generating portion  40  (see  FIG. 3 ) controlled by the controller  200 . Therefore, the side surface sucking portion  144  grips the side surface Pb of the package P by means of suction. 
     The numbers of the first suction pads  142   b  and the second suction pads  144   b  of the grip portion  30  each may be one or more. The first suction pads  142   b  and the second suction pads  144   b  grip the package P by means of vacuum suction by the negative pressure generating portion  40 . When the first suction pads  142   b  and the second suction pads  144   b  are brought under a negative pressure in a state in which the first suction pads  142   b  and the second suction pads  144   b  are in contact with the surfaces of the package P, the first suction pads  142   b  and the second suction pads  144   b  are vacuum-sucked to the surfaces of the package P. When the negative pressure in the first suction pads  142   b  and the second suction pads  144   b  is released, the suction pads release the package P. The gripping and grip releasing of the package P are performed when the controller  200  controls the negative pressure generating portion  40 . 
     Various gripping mechanisms other than the suction pads may be adopted as the grip portion  30 . The grip portion may include, for example, a gripper that grips the package P. The gripper includes a plurality of fingers and a plurality of articulation mechanisms connecting the plurality of fingers. The articulation mechanism may be configured such that the finger operates in conjunction with the operation of the articulation mechanism. The gripper applies a force to the package, for example, from a plurality of opposing directions at two or more points of contact by the plurality of fingers. With this configuration, the grip portion grips the package by means of friction generated between the finger and the package. As described above, various gripping mechanisms capable of gripping the package P of the package group B may be used. 
     The grip portion  30 , that is, the upper surface sucking portion  142  and the side surface sucking portion  144  are rotated together with the base portion  122  of the support portion  26  and the second moving device  28  within a predetermined range by the rotation shaft  124  of the support portion  26 . 
     The lifting and lowering portion  34  that lifts and lowers the intermediate conveyor portion  32  is provided on the frame  22  of the unloading apparatus  12 . The intermediate conveyor portion  32  is supported by the lifting and lowering portion  34 . 
     The lifting and lowering portion  34  includes, for example, a shaft  92  that extends in the Y-axis direction and is supported by the beam portion  52   b  at the upper end of the frame body  52 , a Z-axis actuator  94  that is supported by one end of the shaft  92  and rotates the shaft  92 , and a plurality of wires  96  wound around the shaft  92 . The shaft  92  may extend not in the Y-axis direction but in the X-axis direction. When the Z-axis actuator  94  is driven, the shaft  92  rotates. When the shaft  92  rotates, the intermediate conveyor portion  32  supported by the wires  96  is lifted and lowered. 
     The intermediate conveyor portion  32  is, for example, a belt conveyor. The intermediate conveyor portion  32  may be a roller conveyor. The intermediate conveyor portion  32  includes, for example, a belt  102  on which the package can be placed and a motor  104  that drives the belt  102 . The belt  102  is an endless belt. An upper surface  102   a  of the belt  102  is movable, for example, in the front-rear direction (X-axis direction) by a motor  42 . The package P grasped by the grip portion  30  is placed on the upper surface  102   a  of the intermediate conveyor portion  32  due to the movement and grip releasing of the grip portion  30 . 
     One end of the belt  102  is located near the front opening  56   a . The other end of the belt  102  is located near the rear opening  56   b . The distance from the one end of the belt  102  on the main conveyor  14  side to an upper surface  14   a  of the main conveyor  14  is smaller than the dimension of the package P in the X-axis direction, and is set to a distance by which the package P is moved from the upper surface  102   a  of the belt  102  to the main conveyor  14 . In other words, the gap between the belt  102  and the upper surface  14   a  of the main conveyor  14  is set to a gap through which the package P does not fall. 
     The lifting and lowering portion  34  lifts and lowers the intermediate conveyor portion  32  so as to arrange the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32  at a position slightly higher than the upper surface  14   a  of the main conveyor  14 . When the upper surface  102   a  of the belt  102  moves toward the main conveyor  14 , the package P placed on the upper surface  102   a  is carried out to the main conveyor  14 . 
     For the lifting and lowering portion  34 , an example in which the shaft  92  and the actuator  94  are disposed on the upper side of the frame  22  has been described. The lifting and lowering portion  34  may be arranged on the lower side of the intermediate conveyor portion  32  to arrange the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32  at a desired position. 
     The lifting and lowering portion  34  is simply required to be configured to lift and lower the intermediate conveyor portion  32 . The above-described configuration of the lifting and lowering portion  34  is an example and is not limited thereto. 
     The unloading apparatus  12  includes the controller  200 . The controller  200  controls operation of each portion of the unloading apparatus  12 . The main conveyor  14  may be controlled by the controller  200  or may be controlled by another controller. The controller  200  may be arranged adjacent to the frame  22  of the unloading apparatus  12  and the main conveyor  14 , or may be located away from the frame  22  of the unloading apparatus  12  and the main conveyor  14 . 
     The controller  200  includes a communication interface  202 , a processor  204 , a memory  206 , and a storage  208 . These can communicate with each other via a bus line  210 . 
     The communication interface  202  is an interface used for communication with an external device. The communication interface  202  includes a terminal and a circuit corresponding to a communication standard or the like for the controller  200  to communicate with each portion of the unloading apparatus  12 . The communication interface  202  is connected to and communicates with each of the first moving device  24 , the grip portion  30 , the intermediate conveyor portion  32 , the first sensor  36 , and the second sensor  38  in a wired or wireless manner under the control of the processor  204  via a network N. The controller  200  (processor  204 ) controls the X-axis actuator  86   a , the Y-axis actuator  86   b , the Z-axis actuator  74 , and the rotation actuator  134  of the first moving device  24 , the driving portion  126   c  of the second moving device  28 , the grip portion  30 , the motor  42  of the intermediate conveyor portion  32 , the Z-axis actuator  94  of the lifting and lowering portion  34 , the first sensor  36 , and the second sensor  38 . 
     The processor  204  includes, for example, a central processing unit (CPU). The memory  206  includes a read only memory (ROM) that is a read-only data memory or a random access memory (RAM) that temporarily stores data. The storage  208  may be a mass storage such as a hard disk drive (HDD) or a solid state drive (SSD). The memory  206  or the storage  208  stores control programs and various data of each device of the unloading apparatus  12 . The processor  204  performs various processes based on a program or the like stored in the memory  206  or the storage  208 . That is, the processor  204  executes various programs as a software function unit. An application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or the like serving as a hardware functional unit may be used instead of the CPU. 
     Next, an example of the operation of the unloading apparatus  12  will be described with reference to  FIGS. 4 to 7 . Hereinafter, what the processor  204  executes includes what the controller  200  executes. 
     The processor  204  brings the unloading apparatus  12  into the initial state. The initial state is a state in which at least the first moving device  24 , the support portion  26 , the second moving device  28 , and the grip portion  30  are located at the initial positions (fixed positions), and the intermediate conveyor portion  32  is stopped. The intermediate conveyor portion  32  is located at a predetermined height. At this time, the rotation actuator  134  pulls the piston  134   b  into the cylinder  134   a.    
     The mount portion  8  is arranged at a predetermined position below the protrusion portion  54  and the first sensor  36  of the unloading apparatus  12 . One or a plurality of packages P (package group B) are placed on the mount portion  8  in advance. The processor  204  performs control so that the first sensor  36  photographs the plurality of packages P 1  placed on the mount portion  8 , transmits detection information such as a photographed image to the processor  204  to recognize the position, size, and shape of the package P 1  (step S 101 ). That is, the processor  204  performs control so that the first sensor  36  acquires information on the package P 1  including position information of the package P 1 . The processor  204  stores the detection information obtained by the first sensor  36  in the memory  206  and/or the storage  208 . 
     When the presence of the package P is not recognized from the detection information from the first sensor  36 , the processor  204  performs control to temporarily end the processing (No in step S 102 ). 
     When the presence of the package P 1  is recognized (Yes in step S 102 ), the processor  204  performs control to formulate an action plan for carrying out the package P 1  (step S 103 ). In step S 103 , the processor  204  performs control to formulate the action plan based on the detection information (recognition result) of the first sensor  36  recognized in step S 101 , that is, the position, size, and shape of the package P 1  in the uppermost stage Us. 
     The processor  204  determines the order of the packages P 1  to be unloaded from the plurality of packages P 1  in the uppermost stage Us recognized by the first sensor  36 . For example, the processor  204  determines the unloading order of each package P 1  in the uppermost stage Us so as to unload each package P 1  in the uppermost stage Us onto the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32  at the shortest moving distance of the first moving device  24 . The action plan of the processor  204  includes simultaneously gripping not only one but also a plurality of packages P 1  based on the size (width in the left-right direction) of the package P 1  acquired from the detection information of the first sensor  36 . 
     The processor  204  performs control so that the first moving device  24  moves the grip portion  30  to the gripping position of the package P 1  to be grasped in the uppermost stage Us according to the action plan (for example, the order of gripping) in step S 103  (step S 104 ). That is, the processor  204  operates the X-axis actuator  86   a , the Y-axis actuator  86   b , and the Z-axis actuator  74  so that the first moving device  24  moves the grip portion  30  to the gripping position of the package P 1 . 
     Here, the gripping position refers to a position where the first suction pads  142   b  of the upper surface sucking portion  142  are brought into contact with the upper surface Pa of the package P 1  to be grasped placed on the mount portion  8 . 
     At this time, the Z-axis actuator  94  of the intermediate conveyor portion  32  is controlled to adjust the height position of the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32  so that the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32  does not make contact with the first moving device  24 , the support portion  26 , and the grip portion  30 . 
     The rotation actuator  134  is in a state in which the piston  134   b  is pulled in. At this time, the lower ends of the plurality of suction pads  142   b  of the upper surface sucking portion  142  are parallel to the XY plane. Therefore, the plurality of suction pads  142   b  of the upper surface sucking portion  142  come into contact with the upper surface Pa of the package P 1  substantially simultaneously. Immediately before, at the same time as, or immediately after the plurality of suction pads  142   b  of the upper surface sucking portion  142  come into contact with the upper surface Pa of the package P 1 , the processor  204  performs control to drive the driving portion  126   c  of the second moving device  28  to move the moving portion  126   b  forward in the X-axis direction. At this time, the ends of the plurality of suction pads  144   b  of the side surface sucking portion  144  on the side surface Pb side of the package P 1  are parallel to the YZ plane. Therefore, the plurality of suction pads  144   b  of the side surface sucking portion  144  come into contact with the side surface Pb of the package P 1  substantially simultaneously. That is, the processor  204  performs control so that the grip portion  30  is brought into contact with the upper surface Pa and the side surface Pb on the near side of the package P 1 . 
     The processor  204  performs control to operate the negative pressure generating portion  40  to cause the first suction pads  142   b  and the second suction pads  144   b  to have a negative pressure until the vacuum pressure becomes constant. Thus, the processor  204  causes the suction pads  142   b  and  144   b  of the grip portion  30  to vacuum-suck and grip the upper surface Pa and the side surface Pb of the package P 1  to be grasped. Therefore, as shown in  FIG. 5 , the processor  204  causes the grip portion  30  located on the end side of the first moving device  24  to grip the package P (step S 105 ). 
     At this time, the lower ends of the plurality of suction pads  142   b  of the upper surface sucking portion  142  are parallel to the XY plane. The ends of the plurality of suction pads  144   b  of the side surface sucking portion  144  on the side surface Pb side of the package P are parallel to the YZ plane. 
     The processor  204  performs control to release the piston  134   b  from the cylinder  134   a  of the rotation actuator  134 . The processor  204  operates the X-axis actuator  86   a , the Y-axis actuator  86   b , the Z-axis actuator  74 , and the rotation actuator  134 . At this time, the processor  204  controls the first moving device  24  to move the first moving device  24  upward of the package P along a direction intersecting the side surface Pb of the package P sucked by the side surface sucking portion  144  or a surface obtained by virtually extending the side surface Pb of the package P in a state in which the upper surface Pa and the side surface Pb of the package P are sucked by the upper surface sucking portion  142  and the side surface sucking portion  144 . The processor  204  moves the rotation shaft  124  parallel to the Y-axis direction in a direction away from the frame  22  and upward along an appropriate locus using the first moving device  24 . At this time, the unloading apparatus  12  moves the package P 1  while pressing the upper surface Pa of the package P 2  on the lower side downward with a downward force with the bottom surface Pc of the package P 1  grasped by the grip portion  30 . Therefore, a downward pressing force acts on the package P 2  on the lower side due to the movement of the package P 1 , so that the bottom surface Pc of the package P 1  is easily peeled off from the anti-slip treatment agent S on the upper surface Pa of the package P 2 . 
     The processor  204  has released the piston  134   b  from the cylinder  134   a  of the rotation actuator  134 . Therefore, when the rotation shaft  124  is moved along the appropriate locus, the support portion  26  rotates with respect to the fixed position due to the weights of the support portion  26 , the grip portion  30  (the upper surface sucking portion  142  and the side surface sucking portion  144 ), and further the package P 1 . The processor  204  performs control to apparently push out the piston  134   b  from the cylinder  134   a  of the rotation actuator  134 . The arm  122   a  of the base portion  122  of the support portion  26  and the moving portion  126   b  of the second moving device  28  rotate about the axis of the rotation shaft  124  with respect to the direction of the arm  122   a  of the base portion  122  along the X-axis direction, while maintaining the parallel state. Therefore, the arm  122   a  of the base portion  122  is inclined. That is, the support portion  26  and the grip portion  30  rotates about the predetermined rotation shaft  124 . 
     The processor  204  performs control to apparently move the grip portion  30  from a near side to a far side (away side) with respect to the frame  22  of the unloading apparatus  12  using the X-axis actuator  86   a  of the first moving device  24 , press the package P from the near side to the far side with the side surface sucking portion  144  while appropriately operating the X-axis actuator  86   a , the Y-axis actuator  86   b , the Z-axis actuator  74 , and the rotation actuator  134  of the first moving device  24  to raise the upper surface sucking portion  142 . Therefore, the processor  204  performs control to move the near side of the bottom surface Pc of the package P upward with respect to the far side while lifting the near side of the package P from the position shown in  FIG. 5  to the position shown in  FIG. 6  (step S 106 ). 
     Here, the near side refers to the main conveyor  14  side along the X-axis direction with respect to the unloading apparatus  12 . The far side refers to the side away from the main conveyor  14  along the X-axis direction with respect to the unloading apparatus  12 . 
     As a result, the package P 1  rotates to the far side with a side Pd of the lower end on the far side of the package P 1  along the Y-axis direction (an end of the bottom surface Pc of the package P 1  away from the side surface Pb sucked by the side surface sucking portion  144 ) serving as a supporting axis. At this time, the side Pd maintains its position. Therefore, the package P 2  on the lower side of the package P 1  grasped by the grip portion  30  is pressed downward and is restricted from moving upward by the side Pd of the package P 1 . 
     At this time, the angle between the bottom surface Pc of the package P 1  grasped by the grip portion  30  and the upper surface Pa of the package P 2  on the lower side is 10 degrees to 15 degrees, for example. In addition, the distance between the bottom side of the side surface Pb grasped by the side surface sucking portion  144  of the package P 1  grasped by the grip portion  30  and the upper surface Pa of the package P 2  on the lower side is about several centimeters, for example, about 5 cm. The angle and the distance are merely required to allow, for example, the bottom surface Pc of the package P 1  grasped by the grip portion  30  to be separated from the anti-slip treatment agent S on the upper surface Pa of the package P 2  on the lower side. 
     The package P grasped by the grip portion  30  presses the package P on the farther side than the package P grasped by the grip portion  30  with respect to the frame  22  of the unloading apparatus  12  toward the far side (away side), depending on a gap with the package P on the far side with respect to the frame  22  of the unloading apparatus  12 . When the package P on the far side is pressed toward the far side by the package P grasped by the grip portion  30 , as shown in  FIG. 6 , the package P on the far side in the uppermost stage Us elastically deforms while maintaining a state in which the bottom surface Pc is in contact with the upper surface Pa of the package P in the middle stage Ms on the lower side. 
     As described above, the processor  204  performs control to lift the upper surface Pa on the near side of the package P 1  upward with respect to the upper surface Pa on the far side, without substantially moving the side Pd on the far side of the package P 1 , while pressing the side surface Pb of the package P 1  grasped by the grip portion  30  to the far side in the unloading apparatus  12 . That is, the processor  204  causes the package P 1  grasped by the grip portion  30  in the unloading apparatus  12  to rotate with the side Pd of the package P 1  serving as a supporting axis. In this manner, the processor  204  performs control so that the unloading apparatus  12  peels off the bottom surface Pc of the package P 1  grasped by the grip portion  30  from the anti-slip treatment agent S on the upper surface Pa of the package P 2  on the lower side of the package P 1  grasped by the grip portion  30 . As described above, the unloading apparatus  12  raises the lower end of the side surface Pb sucked by the side surface sucking portion  144  on the bottom surface Pc of the package P 1 , with respect to the end Pd away from the side surface Pb sucked by the side surface sucking portion  144  on the bottom surface Pc of the package P 1 . At this time, the bottom surface Pc serving as a point of action is raised due to the principle of leverage with the end Pd serving as a fulcrum and the sucking portions  142 , 144  serving as a point of force. Since the end Pd itself of the package P 1  is not separated from the upper surface Pa of the package P 2  on the lower side and is not actually lifted, the bottom surface Pc of the package P 1  can be peeled off with a light force from the anti-slip treatment agent S on the upper surface Pa of the package P 2  below the package P 1  grasped by the grip portion  30 . 
     As in the related art, when the package P 1  grasped by the grip portion  30  is simply moved upward along the Z-axis direction with respect to the package P 2  on the lower side, a tensile load is applied to the bottom surface Pc of the package P 1  so as to peel off the bottom surface Pc of the package P 1  substantially simultaneously with respect to all the contact surfaces with the anti-slip treatment agent S between the package P 1  grasped by the grip portion  30  and the package P 2  on the lower side. In this case, a load may be applied to the bottom surface Pc of the package P 1  grasped by the grip portion  30  and the upper surface Pa of the package P 2  below the package P 1  grasped by the grip portion  30 . In addition, when the bottom surface Pc of the package P 1  is peeled off from the anti-slip treatment agent S, the bottom surface Pc may not be peeled off over an appropriate time and be rapidly peeled off. In this case, appropriate vibration may be applied to the grip portion  30 . The vibration input can be a load on the grip portion  30 . The vibration input can be a load on the entire unloading apparatus  12  including the grip portion  30 . 
     As in the present embodiment, when the unloading apparatus  12  rotates the grasped package P 1  with the side Pd serving as a supporting axis without substantially moving the side Pd with respect to the package P 2  on the lower side, the bottom surface Pc of the package P 1  is gradually peeled off from the contact surface with the anti-slip treatment agent S between the bottom surface Pc of the package P 1  and the upper surface Pa of the package P 2  on the lower side due to the principle of leverage while restricting the upward movement of the package P 2  using the side Pd of the package P 1 . Therefore, the load on the bottom surface Pc of the package P 1  due to the adhesion of the anti-slip treatment agent S becomes small as the rotation amount about the side Pd of the package P 1  serving as the supporting axis becomes large. That is, the contact surface with the anti-slip treatment agent S between the bottom surface Pc of the package P 1  and the upper surface Pa of the package P 2  on the lower side does not suddenly become small but gradually becomes small. Therefore, when the bottom surface Pc of the package P 1  is peeled off from the anti-slip treatment agent S, it is unlikely that appropriate vibration is applied to the grip portion  30 . In other words, when the package P 1  is grasped and lifted by the grip portion  30 , the load is hardly generated on not only the grip portion  30  but also the entire unloading apparatus  12  because the package P 2  below the package P 1  grasped by the grip portion  30  is prevented from being hung in a row due to the anti-slip treatment agent S. Then, by operating the unloading apparatus  12  based on the control by the controller  200  as in the present embodiment, the unloading apparatus  12  reduces the load on the bottom surface Pc of the package P 1  and alleviates the load on the upper surface Pa (exterior) of the package P 2  on the lower side. 
     The processor  204  performs control so that the first moving device  24  operates the grip portion  30  from the position shown in  FIG. 6  to the position shown in  FIG. 7 . 
     The processor  204  measures the height of the bottom surface Pc of the package P 1  grasped by the grip portion  30  and moved to the position shown in  FIG. 7  using the second sensor  38 . The processor  204  performs control to operate the Z-axis actuator  94  based on the height of the bottom surface Pc of the package P 1  measured by the second sensor  38  and move the intermediate conveyor portion  32  to an appropriate height. That is, the lifting and lowering portion  34  that lifts and lowers the intermediate conveyor portion  32  is caused to move the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32  to the same position as or slightly lower than the position of the bottom surface Pc of the package P 1  (step S 107 ). 
     The height of the package P 1  grasped by the grip portion  30  can be calculated based on the information on the distance to the upper surface. Pa of the package P 1  already acquired by the first sensor  36  and the distance to the bottom surface Pc of the package P 1  by the second sensor  38 . 
     After adjusting the height of the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32 , the processor  204  moves the grip portion  30  to a position where the package P 1  is to be placed (the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32 ) using the first moving device  24 . 
     When the grip portion  30  is moved by the first moving device  24  to the position where the package P 1  is to be placed (the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32 ) after the first moving device  24  is moved upward of the package P 1  and the package P 1  is rotated with the side Pd serving as a supporting axis, the processor  204  performs control so that the first moving device  24  moves the side surface sucking portion  144  in a direction away from the package P in a state in which the side surface Pb of the package P is sucked by the side surface sucking portion  144 . In other words, the processor  204  controls the first moving device  24  so that the side surface sucking portion  144  is moved in the direction toward the near side along the direction intersecting the side surface Pb of the package P 1  or the surface obtained by virtually extending the side surface Pb. Therefore, the processor  204  performs control to operate the first moving device  24  to move the package P already grasped by the grip portion  30  in a direction away from the side surface Pb where the package P is assumed to be the one immediately before being grasped by the grip portion  30 . That is, the direction in which the first moving device  24  is separated or the direction toward the near side in which the first moving device  24  is moved refers to a direction in which the side surface sucking portion  144  is separated from the side surface Pb of the package P by operating the second moving device  28  when the support portion (rotation portion)  26  is at the fixed position. The direction in which the first moving device  24  is moved to be separated coincides or substantially coincides with the horizontal direction. 
     Therefore, the processor  204  controls the first moving device  24  to move the package P grasped by the grip portion  30  horizontally or substantially horizontally and performs control to move the package P to the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32  along the X axis through the front opening  56   a  of the frame  22  (step S 108 ). At this time, the processor  204  appropriately operates the X-axis actuator  86   a , the Y-axis actuator  86   b , and the Z-axis actuator  74  of the first moving device  24 . In this case, the unloading apparatus  12  pulls the package P 1  to above the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32  through the front opening  56   a  of the frame  22  while gripping the package P 1  with the grip portion  30  and bringing the side Pd of the rotated package P 1  into contact with the upper surface Pa of the package P 2  on the lower side. 
     With such control, when the package P 1  grasped by the grip portion  30  is pulled to above the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32 , the side Pd of the package P 1  comes into contact with the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32 . 
     The processor  204  controls the negative pressure generating portion  40  to release the generation of the negative pressure, and performs control to release the suction to the package P grasped by the grip portion  30  and release the package P onto the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32  (step S 109 ). The processor  204  causes the grip portion  30  to release the grasped package P and operates the Z-axis actuator  74  of the first moving device  24  to move the upper surface sucking portion  142  of the grip portion  30  upward. The processor  204  drives the driving portion  126   c  of the second moving device  28  to move the moving portion  126   b  to the near side along the X-axis direction to retract the side surface sucking portion  144  to the near side along the X-axis direction with respect to the package P, that is, to the main conveyor  14  side. At this time, the processor  204  operates the rotation actuator  134  to pull the piston  134   b  into the cylinder  134   a  to make the arm  122   a  of the base portion  122  of the support portion  26  parallel to the X-axis direction and the extension portion  122   b  of the base portion  122  parallel to the Y-axis direction. 
     The processor  204  operates the Z-axis actuator  94  of the lifting and lowering portion  34  to adjust the height of the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32  to the height of the main conveyor  14  (step S 110 ). At this time, in order to prevent the first moving device  24  and the package P from coming into contact with each other, the processor  204  operates the Z-axis actuator  74  of the first moving device  24  as necessary to further move the first moving device  24  upward. The processor  204  drives the motor  42  of the intermediate conveyor portion  32  to operate the belt  102  of the intermediate conveyor portion  32 . Therefore, the package P is carried out to the outside of the frame  22  through the rear opening  56   b  of the frame  22  and placed on the main conveyor  14 . 
     The processor  204  determines whether or not there is another package P 1  in the same stage Us of the package group B (step S 111 ). At this time, the processor  204  may determine the presence or absence of the package P 1  based on the information already detected by the first sensor  36 , or may obtain the information on the presence or absence of the package P 1  again using the first sensor  36 . If there is another package P 1  in the same stage Us (Yes in step S 111 ), the process returns to step S 104 . If there is no other package P 1  in the same stage Us (No in step S 111 ), the process returns to step S 101 . 
     As described above, the unloading apparatus  12  unloads all the packages P 1  with an appropriate height one by one or a plurality of packages P 1 , such as two packages arranged in the left-right direction (Y-axis direction), simultaneously, from the uppermost stage Us of the package group B on the mount portion  8  onto the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32 , and carries out the unloaded package P 1  to the main conveyor  14 . Thereafter, the unloading apparatus  12  unloads all the packages P 2  one by one or a plurality of packages P 2 , such as two packages arranged in the left-right direction (Y-axis direction), simultaneously, from the middle stage Ms of the package group B on the mount portion  8  onto the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32 , and carries out the unloaded package P 2  to the main conveyor  14 . Thereafter, further, the unloading apparatus  12  unloads all the packages P 3  one by one or a plurality of packages P 3 , such as two packages arranged in the left-right direction (Y-axis direction), simultaneously, from the lowermost stage Ls of the package group B on the mount portion  8  onto the upper surface  102   a  of the belt  102  of the intermediate conveyor portion  32 , and carries out the unloaded package P 3  to the main conveyor  14 . 
     In a case where the package P 3  in the lowermost stage Ls is rotated about the side Pd of the package P 3  by the unloading apparatus  12 , the unloading apparatus  12  has no package P further below. In this case, the unloading apparatus  12  controls the first moving device  24  to press the mount portion  8  downward with the bottom surface Pc of the package P 3 . In addition, the unloading apparatus  12  controls the first moving device  24  to maintain a state in which the side Pd of the package P 3  is in contact with the mount portion  8 . 
     In a case where two packages P arranged in the left-right direction are simultaneously grasped by the grip portion  30 , a load that is, for example, approximately twice as large as that in a case where one package P is grasped is applied to the grip portion  30 . However, since the respective packages P are grasped by the suction pads  142   b  and  144   b , it is not necessary to greatly increase the negative pressures in the first suction pad  142   b  and the second suction pad  144   b  in accordance with the package P. 
     The arrangement and dimensions of each package P of the package group B may be stored in advance in the storage  208  of the controller  200 . 
     In the present embodiment, an example using the first sensor  36  and the second sensor  38  has been described. The first sensor  36  and the second sensor  38  may be unnecessary. For example, in a case where the mount portion  8  is arranged at a predetermined position and the position of the mount portion  8  and the position, size, and shape of each package P of the package group B with respect to the mount portion  8  are stored in, for example, the storage  208  or the like, each package P can be carried out to the main conveyor  14  using the unloading apparatus  12  according to a control program for carrying out the package P created in advance and stored in the memory  206  and/or the storage  208  or the like without formulating an action plan. It is also preferable that the control program is not stored in the memory  206  and/or the storage  208  but is placed on an appropriate server or a cloud. In this case, the control program is executed while communicating with the processor  204  via the communication interface  202 . 
     In the present embodiment, an example of using the first moving device  24 , the support portion (rotation portion)  26 , and the second moving device  28  forming the orthogonal arm to appropriately rotate the grip portion  30  has been described. Also by using a six-axis robot instead of the first moving device  24 , the support portion  26 , and the second moving device  28 , it is possible to unload the package P onto the intermediate conveyor portion  32  or the like while minimizing the influence of the anti-slip treatment agent S by rotating the package P with the side indicated by the reference sign Pd of each package P serving as a supporting axis, and separating the bottom surface Pc of the package P 1  on the upper side from the upper surface Pa of the package P 2  on the lower side. 
     In the present embodiment, it has been described that the rotation shaft  124  of the support portion  26  is parallel to the Y-axis direction. The rotation shaft  124  of the support portion  26  may be rotatable within an appropriate range on the XY plane, for example, with the movable portion  86  of the horizontal moving device  64  serving as a fulcrum. In this case, even if the side surface Pb of the package P placed on the mount portion  8  is not parallel to the YZ plane, the package P can be appropriately grasped by the side surface sucking portion  144  of the grip portion  30 . 
     In the present embodiment, an example in which the anti-slip treatment agent S is present between the upper and lower packages P 1  and P 2  and between the packages P 2  and P 3  has been described. Even when the anti-slip treatment agent S is not present between the upper and lower packages P 1  and P 2  and between the packages P 2  and P 3 , it is possible to unload the package P in the same manner using the unloading apparatus  12 . 
     When the package P is simply lifted upward along the Z-axis direction by a general unloading apparatus, the package immediately below the grasped package P that is present via the anti-slip treatment agent S may be hung or about to be hung together with the grasped package P without being grasped by the grip portion. At this time, a load such as that twice as large as the planned package P is unintentionally applied to the grip portion of the unloading apparatus. Therefore, in the unloading apparatus, a gripping error may occur, such as the hung package P falling off due to gravity or the package falling off from the grip portion. To prevent the package from falling off from the grip portion, the unloading apparatus can increase the gripping force of the grip portion. However, the increase in the gripping force may apply a large load to the exterior of the package P such as cardboard. 
     On the other hand, the unloading apparatus  12  according to the present embodiment can reduce the influence of the anti-slip treatment agent S before lifting and separating the grasped package P 1  upward from the package P 2  on the lower side by rotating the bottom surface Pc of the package P 1  on the upper side with one side Pd of the bottom surface Pc serving as a supporting axis while maintaining the position of the upper surface Pa of the package P 2  on the lower side. The unloading apparatus  12  according to the present embodiment can unload each package P from the package group B onto the intermediate conveyor portion  32  while gripping the package P 1  on the upper side with the grip portion  30  with less influence of the anti-slip treatment agent S in the gap with the package P 2  on the lower side. Therefore, a load such as that twice as large as the planned package P is prevented from being unintentionally applied to the grip portion  30  of the unloading apparatus  12 . As a result, the unloading apparatus  12  according to the present embodiment can suppress the possibility that the gripping error occurs in the grip portion  30  compared with the unloading apparatus having a grip portion that simply lifts the package P upward. 
     In addition, the unloading apparatus  12  according to the present embodiment can simultaneously grip a plurality of packages P such as two packages arranged in the left-right direction. At this time, each package P is in contact with both the upper surface sucking portion  142  and the side surface sucking portion  144 . Therefore, even in a case where the plurality of packages P arranged in the left-right direction are simultaneously grasped by the grip portion  30 , it is not necessary, for example, to increase the magnitude of the negative pressure (gripping force) of the suction pads  142   b  and  144   b  of the grip portion  30  compared with a case where only one package P is grasped. As a result, a large load can be prevented from being applied to the exterior of the package P such as cardboard. 
     For the moving device  24  of the unloading apparatus  12  according to the present embodiment, an example that uses the connecting portion  66  having the rotation actuator  134  has been described. The connecting portion  66  is not necessarily required as long as the support portion  26  can be arranged at the initial position (fixed position) due to energizing when the package P is not grasped by the grip portion  30 , for example, by disposing a coil spring on the rotation shaft  124 . When the package P having an appropriate weight is grasped by the grip portion  30 , the support portion  26  may rotate due to gravity within a predetermined range at an appropriate speed while the coil spring plays a role of a damper from the position shown in  FIG. 5  to the position shown in  FIG. 6 . 
     In the unloading apparatus  12  according to the present embodiment, an example has been described in which the package P 1  grasped by the grip portion  30  is rotated so as to reduce the influence of the anti-slip treatment agent S on the upper surface Pa of the package P 2  on the lower side by separating the near side of the bottom surface Pc of the package P 1  with respect to the far side. The unloading apparatus  12  may rotate the package P 1  grasped by the grip portion  30  so as to reduce the influence of the anti-slip treatment agent S on the upper surface Pa of the package P 2  on the lower side by separating the far side of the bottom surface Pc of the package P 1  with respect to the near side. 
     The unloading apparatus  12  according to the present embodiment includes the upper surface sucking portion (first sucking portion)  142  that sucks the upper surface Pa of the package P, the side surface sucking portion (second sucking portion)  144  that sucks the side surface Pb of the package P, the first moving device  24  that moves the upper surface sucking portion  142  and the side surface sucking portion  144 , the support portion (rotation portion)  26  that rotatably connects the upper surface sucking portion  142  and the side surface sucking portion  144  to the first moving device  24 , and the processor  204  that controls the first moving device  24 . The processor  204  controls the first moving device  24  to move the upper surface Pa and the side surface Pb of the package P upward along the direction intersecting the side surface Pb of the package P sucked by the side surface sucking portion  144  or a surface obtained by virtually extending the side surface Pb of the package P in a state in which the upper surface Pa and the side surface Pb of the package P are sucked by the upper surface sucking portion  142  and the side surface sucking portion  144 . Thereafter, the processor  204  controls the first moving device  24  so that the first moving device  24  moves to a position where the package P is to be placed. 
     In addition, the processor  204  controls the support portion (rotation portion)  26  so that the support portion (rotation portion)  26  is in a rotatable release state with respect to the first moving device  24  during a period from when the package P is sucked by the upper surface sucking portion  142  to when the package P is placed on the position where the package P is to be placed. 
     In addition, the unloading apparatus  12  according to the present embodiment includes the second moving device  28  that moves the side surface sucking portion  144  in a direction approaching the side surface Pb of the package P and in a direction separating from the side surface Pb of the package P. The processor  204  controls the operation of the second moving device  28 . The second moving device  28  is supported by the support portion (rotation portion)  26 . 
     In addition, the processor  204  performs control so that, when sucking the package P and moving the first moving device  24  upward along the direction intersecting the side surface Pb of the package P or a surface obtained by virtually extending the side surface Pb, the end Pd of the bottom surface Pc of the package P away from the side surface Pb sucked by the side surface sucking portion  144  is maintained in contact with the upper surface Pa of the package P on the lower side facing the bottom surface Pc of the package P or the mount portion  8  on which the package P is placed in advance. 
     In addition, the processor  204  controls the first moving device  24  to move in a separating direction when moving the first moving device  24  to the position where the package P is to be placed. 
     In addition, the unloading method according to the present embodiment includes: causing the upper surface Pa of the package P to be sucked by the upper surface sucking portion  142  of the unloading apparatus  12  and causing the side surface Pb of the package P to be sucked by the side surface sucking portion  144  of the unloading apparatus  12 ; moving the upper surface Pa and the side surface Pb of the package P upward along a direction intersecting the side surface Pb of the package P or a surface obtained by virtually extending the side surface Pb in a state in which the upper surface Pa of the package is sucked by the upper surface sucking portion  142  and the side surface Pb of the package P is sucked by the side surface sucking portion  144 ; and moving the package P to the position where the package P is to be placed in a state in which the upper surface Pa of the package P is sucked by the upper surface sucking portion  142  and the side surface Pb of the package P is sucked by the side surface sucking portion  144 . 
     In addition, the unloading method according to the present embodiment makes the upper surface sucking portion  142  and the side surface sucking portion  144  rotatable with respect to the first moving device  24  that moves the upper surface sucking portion  142  and the side surface sucking portion  144  during a period from when the package P is sucked by the upper surface sucking portion  142  and the side surface sucking portion  144  to when the package P is moved to the position where the package P is to be placed. 
     According to at least one embodiment described above, it is possible to provide the unloading apparatus  12  and the unloading method capable of unloading the package more efficiently. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.