Patent Publication Number: US-11396393-B2

Title: Box packing device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the U.S. National Phase of International Application No. PCT/JP2018/040738, filed Nov. 1, 2018. This application claims priority to Japanese Patent Application No. 2018-029351, filed Feb. 22, 2018. The contents of that application are incorporated by reference herein in their entirety. 
     TECHNICAL FIELD 
     The present invention relates to a box packing device for packing articles into boxes. 
     BACKGROUND ART 
     Conventionally, a box packing device for packing articles into boxes, such as disclosed in Japanese Patent Application Publication No. 2004-155428 A, has been known. This box packing device pushes articles into a box conveyed thereto in a state in which an opening thereof faces sideways, thereafter lowers the box, and then pushes more articles into the box in the space above the articles that has just been pushed in. That is, this box packing device pushes the articles into the box by repeatedly performing an operation in which it pushes the articles into the box and an operation in which it lowers the box. 
     BRIEF SUMMARY 
     However, in a case where the articles are sealed bags, the articles are sometimes compressed by a stopper to ensure that the articles do not stick out of the boxes when the articles are pushed into the boxes. In this case, when lowering the boxes, sometimes the articles freed from the stopper expand and stick out of the boxes a little. Additionally, there is the concern that portions of the articles sticking out of the box will get caught so that the articles end up rotating inside the box. As a result, there is the potential for the articles to not be properly packed and for the articles to end up sustaining damage. 
     It is an object of the present invention to provide a reliable box packing device that inhibits the occurrence of a problem where, when packing articles into boxes, the articles end up rotating in the boxes. 
     A box packing device pertaining to the invention includes a push-in mechanism, a retention mechanism, a guide, and a control unit. The push-in mechanism pushes, into a box that is in a state in which an opening thereof faces sideways, an article through the opening. The retention mechanism retains the box that is in a state in which the opening faces sideways and lowers the box after the article have been pushed into the box by the push-in mechanism. The guide opposes the opening and is a member for preventing the article from falling out from the opening of the box that has been lowered by the retention mechanism. The control unit temporarily increases the distance between the box and the guide after the article have been pushed into the box by the push-in mechanism. 
     The box packing device pertaining to the invention inhibits the articles from getting caught on the guide and rotating in a case where the articles have expanded in the box by temporarily moving the box away from the guide after the box packing device has pushed the articles into the box that is in a state in which the openings face sideways. Consequently, the reliability of the box packing device pertaining to the invention can be improved. 
     Furthermore, in the box packing device pertaining to the invention, it is preferred that the control unit temporarily tilt the box so that the opening faces upward. 
     In this case, the box packing device can temporarily move the box away from the guide simply by tilting the box. 
     Furthermore, it is preferred that the box packing device pertaining to the invention further include a shutter. The shutter is a member that is temporarily inserted inside the box while the push-in mechanism is pushing the article into the box. The push-in mechanism pushes the article resting on top of the shutter into the box. 
     In this case, the box packing device can smoothly push the articles into the box by using the shutter. 
     Furthermore, in the box packing device pertaining to the invention, it is preferred that the control unit remove the shutter from the box before temporarily increasing the distance between the box and the guide and, after temporarily increasing the distance between the box and the guide, control the retention mechanism to lower the box, return the distance between the box and the guide to what it was before, and thereafter insert the shutter inside the box. 
     In this case, the box packing device can appropriately control the distance between the box and the guide by removing and inserting the shutter at appropriate timings. 
     Furthermore, in the box packing device pertaining to the invention, it is preferred that the control unit, after inserting the shutter inside the box after having returned the distance between the box and the guide to what it was before, raise the box to a position in which the article that have been pushed into the box come into contact with the shutter. 
     In this case, the box packing device can efficiently pack the articles into the box. 
     Furthermore, it is preferred that the box packing device pertaining to the invention further include a rotation mechanism. The rotation mechanism rotates the box to switch the box between a state in which the opening faces sideways and a state in which the opening faces upward. The control unit controls the rotation mechanism to temporarily increase the distance between the box and the guide. 
     In this case, the box packing device can easily control the distance between the box and the guide using the rotation mechanism. 
     Furthermore, in the box packing device pertaining to the invention, it is preferred that the rotation mechanism have a servo motor for controlling the rotational speed of the box. 
     In this case, the box packing device can easily control the distance between the box and the guide using the servo motor of the rotation mechanism. 
     Furthermore, in the box packing device pertaining to the invention, it is preferred that the guide have a shape that recedes upward from the box. 
     In this case, the box packing device can inhibit the articles from getting caught on the guide and rotating in a case where the articles have expanded in the box. 
     The box packing device pertaining to the invention inhibits the occurrence of a problem where, when packing articles into boxes, the articles end up rotating in the boxes, so an improvement in reliability can be expected. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic front view of a box packing device  10  pertaining to an embodiment of the invention. 
         FIG. 2  is a view, seen from a closed bottom lid B side, of a cardboard box C used in the box packing device  10 . 
         FIG. 3A  is a view for describing the operation of a box packing unit  2 , and shows a state in which the height position of the cardboard box C has been changed by a drop mechanism  20 . 
         FIG. 3B  is a view for describing the operation of the box packing unit  2 , and shows a state just before a first layer of articles A is put into the cardboard box C. 
         FIG. 3C  is a view for describing the operation of the box packing unit  2 , and shows a state just after the first layer of the articles A has been put into the cardboard box C. 
         FIG. 3D  is a view for describing the operation of the box packing unit  2 , and shows a state just before a second layer of the articles A is put into the cardboard box C. 
         FIG. 3E  is a view for describing the operation of the box packing unit  2 , and shows a state just after the second layer of the articles A has been put into the cardboard box C. 
         FIG. 3F  is a view for describing the operation of the box packing unit  2 , and shows a state just before a third layer of the articles A is put into the cardboard box C. 
         FIG. 3G  is a view for describing the operation of the box packing unit  2 , and shows a state just after the third layer of the articles A has been put into the cardboard box C. 
         FIG. 3H  is a view for describing the operation of the box packing unit  2 , and shows a state in which the cardboard box C packed with the articles A is conveyed by a box conveyance mechanism  90 . 
         FIG. 4  is a block diagram of the box packing unit  2 . 
         FIG. 5A  is a diagram for describing the operation of the box packing unit  2 , and shows a state just after the first layer of the articles A has been put into the cardboard box C. 
         FIG. 5B  is a view for describing the operation of the box packing unit  2 , and shows a state in which a shutter has been removed from the cardboard box C. 
         FIG. 5C  is a view for describing the operation of the box packing unit  2 , and shows a state in which the cardboard box C has been tilted. 
         FIG. 5D  is a view for describing the operation of the box packing unit  2 , and shows a state in which the cardboard box C in the tilted state has been moved downward. 
         FIG. 5E  is a view for describing the operation of the box packing unit  2 , and shows a state in which the posture of the cardboard box C in the tilted state has been returned to what it was before. 
         FIG. 5F  is a view for describing the operation of the box packing unit  2 , and shows a state in which the shutter has been reinserted into the cardboard box C. 
         FIG. 5G  is a view for describing the operation of the box packing unit  2 , and shows a state in which the cardboard box C has been moved slightly upward. 
         FIG. 6  is a view showing a state in which an article A that has expanded inside the cardboard box C has gotten caught on a guide  70  and is rotating. 
     
    
    
     DETAILED DESCRIPTION 
     An embodiment of the invention will be described with reference to the drawings. The embodiment described below is a specific example of the invention and is not intended to limit the technical scope of the invention. 
     (1) Configuration and Operation of Box Packing Device 
       FIG. 1  is a general view of a box packing device  10  pertaining to an embodiment of the invention. The box packing device  10  is installed on a line of a food factory, for example, and is a device for box packing articles A that have been produced on the line of the food factory. The box packing device  10  puts, into cardboard boxes C placed in a location to which the articles A to be packed are fed one after another, a plurality of the articles A through openings Op of the cardboard boxes C to thereby box pack them. The articles A are, for example, bags in which a food such as potato chips is packaged by a packaging material. 
     The box packing device  10  mainly includes a box making unit  1 , a box packing unit  2 , and a box closing unit  3 .  FIG. 1  is a schematic front view of the box packing device  10 . 
     In the following description, terms such as upper, lower, left, right, front (front surface), and rear (back surface) are used to describe directions and positions. These terms, unless otherwise specified, mean up, down, left, right, front, and rear indicated by arrows in the drawings. “Right” is the right side in a case where the box packing device  10  is viewed from the front side, and “left” is the left side in a case where the box packing device  10  is viewed from the front side. 
     (1-1) Box Making Unit 
     The box making unit  1  makes the cardboard boxes C having just one side open by opening cardboard sheets S, which are the cardboard boxes C in a collapsed state, closing bottom lids B of the cardboard boxes C, and sealing the bottom lids B shut with tape T.  FIG. 2  is a view of the cardboard box C seen from the closed bottom lid B side. Flaps C 21  to C 24  on an upper lid side opposite the bottom lid B are opened outward. The opened upper lid side of the cardboard box C corresponds to the opening Op of the cardboard box C. 
     The cardboard boxes C made by the box making unit  1  are conveyed by a conveyor (not shown in the drawings) to the box packing unit  2 . The box making unit  1  feeds one after another the cardboard boxes C it has made to the box packing unit  2 . 
     (1-2) Box Packing Unit 
     The box packing unit  2  puts a plurality of the articles A into the cardboard boxes C and thereby box packs them.  FIG. 3A  to  FIG. 3H  are views for describing the operation of the box packing unit  2 .  FIG. 3A  to  FIG. 3H  are schematic views, seen from the right side, of the neighborhood of the box packing unit  2  of the box packing device  10  shown in  FIG. 1 . In  FIG. 3A  to  FIG. 3H , the articles A are put one row at a time six times into the cardboard box C by the box packing unit  2 . One row of the articles A put once into the cardboard box C comprises one article A or a plurality of the articles A arranged in the right and left direction. Even when the number of the articles A per row is plural, only the article A positioned on the rightmost side is shown in  FIG. 3B  to  FIG. 3H . As shown in  FIG. 3G , in the cardboard box C just after a total of six rows of the articles A have been put into it, two rows of the articles A per layer are box packed in a state in which there are three layers of the articles A stacked on top of each other in the up and down direction. The total number of the articles A put into the cardboard box C, the number of the articles A per row, and the number of rows of the articles A per layer are appropriately decided on the basis of the dimensions of the cardboard box C and the articles A. 
     The cardboard boxes C that are in a state in which the openings Op face sideways are supplied to the box packing unit  2  by the conveyor of the box making unit  1 . Specifically, the cardboard boxes C having the bottom lids B formed on the front surface side of the box packing device  10  and having the openings Op formed on the back surface side of the box packing device  10  are supplied to the box packing unit  2 . 
     As shown in  FIG. 2 , the cardboard box C used by the box packing device  10  has four side surfaces C 11  to C 14  that are interconnected in a loop and eight flat panel-like flaps C 21  to C 28  that extend forward and rearward from the four side surfaces C 11  to C 14 . The flap C 21  and the flap C 25  extend from the back surface side and the front surface side, respectively, of the side surface C 11 . The flap C 22  and the flap C 26  extend from the back surface side and the front surface side, respectively, of the side surface C 12 . The flap C 23  and the flap C 27  extend from the back surface side and the front surface side, respectively, of the side surface C 13 . The flap C 24  and the flap C 28  extend from the back surface side and the front surface side, respectively, of the side surface C 14 . 
     At the point in time when the cardboard box C is supplied to the box packing unit  2 , the flaps C 25  to C 28  on the front surface side of the box packing device  10  have been closed and sealed shut with the tape T by the box making unit  1  to form the bottom lid B. However, at the point in time when the cardboard box C is supplied to the box packing unit  2 , the flaps C 21  to C 24  on the back surface side of the box packing device  10  are open outward. That is, the opening Op of the cardboard box C supplied to the box packing unit  2  faces rearward (the back surface side). The cardboard box C is supplied to the box packing unit  2  in a state in which the side surface C 14  faces downward as shown in  FIG. 3A  to  FIG. 3H . 
     The box packing unit  2  mainly has a drop mechanism  20 , a retention mechanism  30 , a rotation mechanism  40 , a push-in mechanism  50 , a shutter  60 , a guide  70 , an article conveyance mechanism  80 , and a box conveyance mechanism  90 . 
     The drop mechanism  20  drops the cardboard boxes C supplied one after another from the box making unit  1 . Because of the drop mechanism  20 , the cardboard boxes C drop in a state in which the side surface portion C 14  faces downward and the opening Op faces rearward. 
     The retention mechanism  30  retains, in the place where the articles A are packed into the cardboard boxes C, the cardboard boxes C that have been dropped by the drop mechanism  20 . Furthermore, the retention mechanism  30  moves the cardboard boxes C that have been packed with the articles A from the place where the articles A were packed to a conveyor belt of the box conveyance mechanism  90 . The retention mechanism  30  has a mechanism that rotates the cardboard boxes C about a predetermined axis. 
     The rotation mechanism  40  rotates the cardboard boxes C to switch them between a state in which the opening Op faces sideways (rearward) as shown in  FIG. 3A  to  FIG. 3G  and a state in which the opening Op faces upward as shown in  FIG. 3H . The axis of rotation for rotating the cardboard boxes C lies along the front and rear direction. 
     The push-in mechanism  50  puts the articles A, which have been conveyed by the article conveyance mechanism  80 , through the openings Op of the cardboard boxes C into the cardboard boxes C being retained by the retention mechanism  30 . The push-in mechanism  50  puts the articles A into the cardboard boxes C by forwardly pushing off the articles A using a push-off plate. 
     The shutter  60  is a tabular member for inhibiting the articles A that have already been put into the cardboard boxes C from obstructing the input of the articles A when the articles A are put into the cardboard boxes C. The shutter  60  is inserted into the cardboard boxes C and is removed from the cardboard boxes C as a result of being driven in the front and rear direction by an air cylinder or the like. 
     The guide  70  prevents the articles A that have already been put into the cardboard boxes C from spilling and falling out of the cardboard boxes C that are in a state in which the opening Op faces sideways. As shown in  FIG. 3A  to  FIG. 3H , the guide  70  has a sloping portion on the upper end portion of its front surface. The sloping portion has a shape that slopes upward and rearward. That is, the sloping portion has a shape that recedes upward away from the cardboard boxes C. 
     The article conveyance mechanism  80  conveys the articles A before they are put into the cardboard boxes C. The article conveyance mechanism  80  conveys the articles A by means of a conveyor belt at predetermined timings so that the articles A are conveyed to the front of the push-off plate of the push-in mechanism  50 . 
     The box conveyance mechanism  90  conveys, in the horizontal direction by means of a conveyor belt, the cardboard boxes C that have been moved by the retention mechanism  30  and which are in a state in which the opening Op faces upward and supplies them to the box closing unit  3 . 
     (1-3) Box Closing Unit 
     The box closing unit  3  closes the flaps C 21  to C 24  of the cardboard boxes C supplied from the box conveyance mechanism  90  of the box packing unit  2  and whose openings Op face upward and seals them shut with tape or the like to form upper lids. The cardboard boxes C whose upper lids have been formed by the box closing unit  3  are conveyed out from the box packing device  10 . 
     (2) Configuration and Operation of Box Packing Unit 
     The detailed configuration of the box packing unit  2  will be described.  FIG. 4  is a block diagram of the box packing unit  2 . The box packing unit  2  has a control unit  100 . The control unit  100  is connected to various elements of the box packing unit  2 , such as the drop mechanism  20 , the retention mechanism  30 , the rotation mechanism  40 , the push-in mechanism  50 , the shutter  60 , the article conveyance mechanism  80 , and the box conveyance mechanism  90 . Furthermore, the control unit  100  is also connected to the box making unit  1  and the box closing unit  3 . The control unit  100  mainly controls the various elements of the box packing unit  2  and exchanges various types of information with the various elements of the box packing unit  2 . The control unit  100  is, for example, a microcomputer. As shown in  FIG. 4 , the control unit  100  includes a storage unit  101  and a computation unit  102 . The storage unit  101  is mainly configured by a ROM, a RAM, and a hard disk drive (HDD). The computation  102  is mainly configured by a CPU. 
     The control unit  100  controls the rotation mechanism  40  to adjust the posture of the cardboard boxes C. Specifically, the control unit  100  controls the angle of the cardboard boxes C so that the posture of the cardboard boxes C becomes an arbitrary posture between a state in which the opening Op faces sideways and a state in which the opening Op faces upward. The rotation mechanism  40  has a servo motor  41 . The control unit  100  controls the servo motor  41  to control the rotational speed of the cardboard boxes C when changing the angle of the cardboard boxes C. 
     The detailed operation of the box packing unit  2  will be described with reference to  FIG. 3A  to  FIG. 3H . First, as shown in  FIG. 3A , the cardboard box C that is in a state in which the opening OP faces sideways is dropped by the drop mechanism  20  so that the height position of the cardboard box C is changed. Specifically, the cardboard box C drops to a predetermined height position while the right-side flap C 21  and the left-side flap C 23  are supported. 
     Next, as shown in  FIG. 3B , the retention mechanism  30  moves to a position in which it comes into contact with the side surface C 14  of the cardboard box C. At this time, the opening Op of the cardboard box C faces sideways, and the side surface C 14  of the cardboard box C is positioned on the lower side. The retention mechanism  30  can move the cardboard box C in the up and down direction in a state in which it sucks hold of the side surface C 14  of the cardboard box C and retains the cardboard box C. Furthermore, as described later, the retention mechanism  30  can rotate the cardboard box C about a predetermined axis in a state in which it retains the cardboard box C. The control unit  100  controls the retention mechanism  30  to move the cardboard box C in the up and down direction and, as shown in  FIG. 3B , move the cardboard box C to a position in which a first layer of two rows of the articles A can be pushed one row at a time into the cardboard box C. Furthermore, the control unit  100  controls the shutter  60  to insert the shutter  60  through the opening Op of the cardboard box C and push in the shutter  60  as far as the neighborhood of the bottom lid B of the cardboard box C. Furthermore, the control unit  100  controls the push-in mechanism  50  to move the push-off plate of the push-in mechanism  50  rearward. Additionally, the articles A to be pushed into the cardboard box C are conveyed one row&#39;s worth at a time by the article conveyance mechanism  80  to the rear of the opening Op of the cardboard box C and the front of the push-off plate of the push-in mechanism  50 . 
     Next, as indicated by the arrow in  FIG. 3B , the control unit  100  controls the push-in mechanism  50  to move the push-off plate of the push-in mechanism  50  forward and forwardly push off a first row of the articles A conveyed by the article conveyance mechanism  80 . Thereafter, the control unit  100  repeats the same control to forwardly push off a second row of the articles A conveyed by the article conveyance mechanism  80 . Because of this, two rows&#39; worth of the articles A are pushed into the cardboard box C while being placed on the shutter  60  as shown in  FIG. 3C . As a result, a first layer of two rows of the articles A is put into the cardboard box C. 
     Next, the retention mechanism  30  moves the cardboard box C downward. Specifically, the control unit  100  controls the retention mechanism  30  to move the cardboard box C downward and thereby move the cardboard box C to a position in which a second layer of two rows of the articles A can be pushed one row at a time into the cardboard box C as shown in  FIG. 3D . Before the retention mechanism  30  moves the cardboard box C downward, the control unit  100  controls the shutter  60  to remove the shutter  60  from the cardboard box C. After the retention mechanism  30  has moved the cardboard box C downward, the control unit  100  controls the shutter  60  to reinsert the shutter  60  through the opening Op of the cardboard box C. Furthermore, the control unit  100  controls the push-in mechanism  50  to move the push-off plate of the push-in mechanism  50  rearward. Additionally, more articles A to be pushed into the cardboard box C are conveyed one row at a time by the article conveyance mechanism  80  to the rear of the opening Op of the cardboard box C and the front of the push-off plate of the push-in mechanism  50 . Details of the operation of moving the cardboard box C downward will be described later. 
     Next, as indicated by the arrow in  FIG. 3D , the control unit  100  controls the push-in mechanism  50  to move the push-off plate of the push-in mechanism  50  forward and forwardly push off a first row&#39;s worth of the articles A conveyed by the article conveyance mechanism  80 . Thereafter, the control unit  100  repeats the same control to forwardly push off a second row&#39;s worth of the articles A conveyed by the article conveyance mechanism  80 . Because of this, two rows&#39; worth of the articles A are pushed into the cardboard box C while being placed on the shutter  60  as shown in  FIG. 3E . As a result, a second layer of two rows of the articles A is put into the cardboard box C. The second layer of two rows of the articles A is positioned above the first layer of two rows of the articles A. 
     Next, the retention mechanism  30  moves the cardboard box C downward. Specifically, the control unit  100  controls the retention mechanism  30  to move the cardboard box C downward and thereby move the cardboard box C to a position in which a third layer of two rows of the articles A can be pushed one row at a time into the cardboard box C as shown in  FIG. 3F . Before the retention mechanism  30  moves the cardboard box C downward, the control unit  100  controls the shutter  60  to remove the shutter  60  from the cardboard box C. After the retention mechanism  30  has moved the cardboard box C downward, the control unit  100  controls the shutter  60  to reinsert the shutter  60  through the opening Op of the cardboard box C. Furthermore, the control unit  100  controls the push-in mechanism  50  to move the push-off plate of the push-in mechanism  50  rearward. Additionally, more articles A to be pushed into the cardboard box C are conveyed one row at a time by the article conveyance mechanism  80  to the rear of the opening Op of the cardboard box C and the front of the push-off plate of the push-in mechanism  50 . 
     Next, as indicated by the arrow in  FIG. 3F , the control unit  100  controls the push-in mechanism  50  to move the push-off plate of the push-in mechanism  50  forward and forwardly push off a first row of the articles A conveyed by the article conveyance mechanism  80 . Thereafter, the control unit  100  repeats the same control to forwardly push off a second row of the articles A conveyed by the article conveyance mechanism  80 . Because of this, two rows&#39; worth of the articles A are pushed into the cardboard box C while being placed on the shutter  60  as shown in  FIG. 3G . As a result, a third layer of two rows of the articles A are put into the cardboard box C. The third layer of two rows of the articles A is positioned above the second layer of two rows of the articles A. At this time, a total of six rows of the articles A have been packed in three layers into the cardboard box C. 
     Next, the control unit  100  controls the shutter  60  to remove the shutter  60  from the opening Op of the cardboard box C. Next, the control unit  100  controls the retention mechanism  30  to move the cardboard box C downward and at the same time controls the rotation mechanism  40  to rotate the cardboard box C 90°. Because of this, the cardboard box C transitions from a state in which the opening Op faces sideways to a state in which the opening Op faces upward. Next, the control unit  100  controls the retention mechanism  30  to move the cardboard box C and place the cardboard box C onto the conveyor belt of the box conveyance mechanism  90  as shown in  FIG. 3H . Next, the control unit  100  cancels the retention of the cardboard box C by the retention mechanism  30 . Next, the cardboard box C is conveyed by the box conveyance mechanism  90 . Because of this, the cardboard box C holding six rows of the articles A is conveyed from the box packing unit  2  to the box closing unit  3 . 
     In this way, the box packing unit  2  puts the articles A in multiple layers into the cardboard box C. Specifically, the box packing unit  2  pushes the articles A one row at a time six times into the cardboard box C while moving the cardboard box C in the up and down direction. Furthermore, the box packing unit  2  pushes the articles A two times per layer into the cardboard box C. For that reason, the operation of moving the cardboard box C in the up and down direction to change the position (layer) in which the articles A are put into the cardboard box C is performed the same number of times as the number of layers (three layers) of the articles A packed into the cardboard box C. 
     Next, details of the operation by which the retention mechanism  30  moves the cardboard box C downward in order for the next layer of the articles A to be pushed into the cardboard box C after the first layer or the second layer of the articles A has been pushed into the cardboard box C will be described.  FIG. 5A  to  FIG. 5G  are views for describing the operation by which the retention mechanism  30  moves downward the cardboard box C holding the first layer of two rows of the articles A.  FIG. 5A  to  FIG. 5G  show a state between those of  FIG. 3C  and  FIG. 3D . 
       FIG. 5A  shows the same state as  FIG. 3C , and shows a state just after the first layer of two rows of the articles A has been put into the cardboard box C. Next, as shown in  FIG. 5B , the shutter  60  is temporarily removed from the cardboard box C in order to move the cardboard box C downward. At this time, the control unit  100  controls the shutter  60  to move the shutter  60  rearward and remove the shutter  60  from the opening Op of the cardboard box C. 
     Next, as shown in  FIG. 5C , the cardboard box C rotates a predetermined angle to a tilted state. At this time, the control unit  100  controls the rotation mechanism  40  and the servo motor  41  to rotate the cardboard box C the predetermined angle so that the opening Op of the cardboard box C faces upward. In  FIG. 5A  to  FIG. 5G , the cardboard box C rotates about an axis of rotation  32 . As shown in  FIG. 5A  to  FIG. 5G , the cardboard box C rotates counter-clockwise in a case where it is viewed from the right side. The angle of rotation of the cardboard box C is, for example, 5° to 30°. The upper flap C 22  of the cardboard box C in the rotated and tilted state is positioned more forward than the lower flap C 24 . The purpose of tilting the cardboard box C in this way is to temporarily increase the distance between the cardboard box C and the guide  70 . Because of this, the articles A already held in the cardboard box C move away from the front surface of the guide  70 , so the articles A in the cardboard box C are inhibited from contacting the guide  70 , as described later. 
     Next, as shown in  FIG. 5D , the cardboard box C moves downward. At this time, the control unit  100  controls the retention mechanism  30  to move the cardboard box C in its tilted state downward along the up and down direction. How much the cardboard box C is moved in the up and down direction is the same as, or substantially the same as, the up and down direction dimension of the articles A held in the cardboard box C. 
     Next, as shown in  FIG. 5E , the cardboard box C rotates a predetermined angle so that the posture of the cardboard box C is returned to what it was before. At this time, the control unit  100  controls the rotation mechanism  40  and the servo motor  41  to rotate the cardboard box C a predetermined angle so that the opening Op of the cardboard box C faces sideways (rearward). As shown in  FIG. 5A  to  FIG. 5G , the cardboard box C rotates clockwise in a case where it is viewed from the right side. The angle of rotation of the cardboard box C is the same as the angle of rotation when the cardboard box C was tilted. For that reason, this rotation operation returns the cardboard box C to a state in which it is not tilted. The cardboard box C before tilting which is shown in  FIG. 5B  and the cardboard box C that has moved downward which is shown in  FIG. 5E  differ only in position in the up and down direction. That is, the position of the cardboard box C in the front and rear direction is the same in  FIG. 5B  and  FIG. 5E . 
     Next, as shown in  FIG. 5F , the shutter  60  is inserted into the cardboard box C. At this time, the control unit  100  controls the shutter  60  to move the shutter  60  forward and insert the shutter  60  through the opening Op of the cardboard box C. At this time, the height position of the shutter  60  is positioned higher than the first layer of the articles A held in the cardboard box C. That is, there is a space between the first layer of the articles A and the shutter  60  in the cardboard box C. 
     Next, as shown in  FIG. 5G , the cardboard box C rises. At this time, the control unit  100  controls the retention mechanism  30  to move the cardboard box C upward along the up and down direction. How much the cardboard box C is moved in the up and down direction is the same as, or substantially the same as, the up and down direction dimension of the space between the first layer of the articles A and the shutter  60  in the cardboard box C. This operation eliminates the space between the first layer of the articles A and the shutter  60  in the cardboard box C. That is, in the cardboard box C, the first layer of the articles A and the shutter  60  come into contact with each other. 
     Next, the control unit  100  controls the push-in mechanism  50  to move the push-off plate of the push-in mechanism  50  rearward. Additionally, one row&#39;s worth of the articles A to be pushed next into the cardboard box C is conveyed by the article conveyance mechanism  80  to the rear of the opening Op of the cardboard box C and the front of the push-off plate of the push-in mechanism  50 . This results in the state shown in  FIG. 3D . 
     The above operation described with reference to  FIG. 5A  to  FIG. 5G  is a preparatory operation for the retention mechanism  30  to move downward the cardboard box C holding the first layer of two rows of the articles A so that the second layer of two rows of the articles A can be put into the cardboard box C. However, the operation shown in  FIG. 5A  to  FIG. 5G  can also be applied to a preparatory operation for the retention mechanism  30  to move downward the cardboard box C holding the second layer of two rows of the articles A so that the third layer of two rows of the articles A can be put into the cardboard box C. 
     (3) Characteristics 
     (3-1) 
     The box packing device  10  performs an operation in which, after it has pushed the articles A into the cardboard box C that is in a state in which the opening Op faces sideways, it temporarily moves the cardboard box C away from the guide  70  while moving the cardboard box C downward as shown in  FIG. 5B  and  FIG. 5C . Specifically, the box packing device  10  moves the cardboard box C downward along the up and down direction as shown in  FIG. 5D  while maintaining the state in which the cardboard box C is away from the guide  70  as shown in  FIG. 5C , and thereafter brings the cardboard box C closer to the guide  70  as shown in  FIG. 5E . 
     The box packing device  10  inhibits, by means of the operation of temporarily moving the cardboard box C away from the guide  70 , the articles A from getting caught on the guide  70  or the like and rotating in a case where the articles A have expanded in the cardboard box C while the box packing device  10  is moving the cardboard box C downward. For example, in a case where the sum of the front and rear direction dimensions of two rows of the articles A that have been put into the same layer in the cardboard box C is longer than the front and rear direction dimension of the cardboard box C, the two rows of the articles A just after having been put into the same layer in the cardboard box C by the push-in mechanism  50  become compressed in the front and rear direction. When the cardboard box C is moved downward in that state, the compressed articles A become freed from the push-in mechanism  50  as shown in  FIG. 6 . Because of this, sometimes the compressed articles A expand in the front and rear direction.  FIG. 6  is a view showing a state in which an article A that has expanded inside the cardboard box C has gotten caught on the guide  70  and is rotating. When the state shown in  FIG. 6  occurs, there is the concern that the article A will become sandwiched between the cardboard box C and the shutter  60  or the like and become compressed. In a case where the articles A are bags in which a food such as potato chips is packaged by a packaging material, there is the concern that if the articles A become compressed the food inside the packaging material will sustain damage. 
     The box packing device  10  ensures, by means of the operation of temporarily moving the cardboard box C away from the guide  70 , that the articles A do not contact the guide  70  even if the articles A expand in the cardboard box C. Consequently, the box packing device  10  inhibits the occurrence of a problem where, when packing the articles A into the cardboard boxes C, the articles A end up rotating inside the cardboard boxes C, so reliability can be improved. Furthermore, because of this, the box packing device  10  can inhibit the occurrence of a state in which the articles A are not properly packed into the cardboard boxes C. 
     (3-2) 
     The box packing device  10  temporarily tilts the cardboard box C so that the opening Op of the cardboard box C faces upward to perform the operation of temporarily moving the cardboard box C away from the guide  70  while moving the cardboard box C downward. Specifically, the box packing device  10  can temporarily move the cardboard box C away from the guide  70  by tilting the cardboard box C using the rotation mechanism  40 . The rotation mechanism  40  is also used to place the cardboard box C packed with the articles A onto the conveyor belt of the box conveyance mechanism  90  as shown in  FIG. 3H . Consequently, the box packing device  10  can easily execute the operation of temporarily moving the cardboard box C away from the guide  70  simply by tilting the cardboard box C using the rotation mechanism  40  for placing the cardboard box C onto the conveyor belt of the box conveyance mechanism  90 . Furthermore, the box packing device  10  can easily control the distance between the cardboard box C and the guide  70  at appropriate timings by using the servo motor  41  of the rotation mechanism  40  to finely set and control the angle of rotation of the cardboard box C. 
     (3-3) 
     The box packing device  10  returns the distance between the cardboard box C and the guide  70  to what it was before and reinserts the shutter  60  inside the cardboard box C as shown in  FIG. 5F , and thereafter raises the cardboard box C to a position in which the articles A that have been pushed into the cardboard box C come into contact with the shutter  60  as shown in  FIG. 5G . In the state shown in  FIG. 5F , a space is formed between the articles A that have been pushed into the cardboard box C and the shutter  60 . By raising the cardboard box C the dimension of the space in this state, the articles A that have been pushed into the cardboard box C come into contact with the shutter  60  as shown in  FIG. 5G . Because of this, when the box packing device  10  puts the third layer of the articles A into the cardboard box C as shown in  FIG. 3F , the occurrence of a situation where the articles A hit the side surface C 12  on the upper side of the cardboard box C such that the articles A are not smoothly put into the cardboard box C is inhibited. Consequently, the box packing device  10  can, by means of the above operation, efficiently pack the articles A into the cardboard boxes C. 
     (3-4) 
     The box packing device  10  includes the guide  70  for preventing the articles A that have already been put into the cardboard box C from spilling and falling out. As shown in  FIG. 3A  to  FIG. 3H , the guide  70  has the sloping portion on the upper end portion of the front surface. The sloping portion has a shape that recedes upward away from the cardboard boxes C. The sloping portion of the guide  70  inhibits to some extent the articles A from getting caught on the guide  70  and rotating in a case where the articles A have expanded in the cardboard box C. When the guide  70  does not have the sloping portion, there is the concern that the corner portion of an article A that has expanded will get caught in the space between the push-off plate of the push-in mechanism  50  and the guide  70 , for example, when the cardboard box C moves downward. When the guide  70  does have the sloping portion, the occurrence of such catching of the articles A is inhibited when the cardboard box C moves downward. 
     (4) Example Modification 
     An embodiment of the invention has been described above, but the invention is not limited to the embodiment and various changes can be made thereto in a range that does not depart from the spirit of the invention. 
     An example modification of the box packing device  10  will be described. The box packing device  10  of the embodiment rotates the cardboard box C a predetermined angle to a tilted state as shown in  FIG. 5C , thereafter moves the cardboard box C downward along the up and down direction as shown in  FIG. 5D , and thereafter rotates the cardboard box C again a predetermined angle to return the posture of the cardboard box C to what it was before as shown in  FIG. 5E . However, the box packing device  10  can also perform another operation with respect to the cardboard box C in addition to the operation of temporarily tilting the cardboard box C when moving the cardboard box C downward. 
     For example, after rotating the cardboard box C a predetermined angle to a tilted state, the box packing device  10  can perform an operation in which it moves the cardboard box C a predetermined distance forward to move it away from the guide  70 . In this case, the box packing device  10  next moves the cardboard box C downward along the up and down direction, thereafter moves the cardboard box C a predetermined distance rearward to bring it closer to the guide  70 , and thereafter rotates the cardboard box C a predetermined angle again to return the posture of the cardboard box C to what it was before. That is, the box packing device  10  further performs, in addition to the operation of rotating the cardboard box C to temporarily move the cardboard box C away from the guide  70 , an operation in which it moves the cardboard box C in the front and rear direction to temporarily move the cardboard box C away from the guide  70 . By means of these operations, the box packing device  10  can sufficiently move the cardboard box C away from the guide  70  when moving the cardboard box C downward. 
     In this example modification, the box packing device  10  can also rotate the cardboard box C a predetermined angle to a tilted state after performing the operation of moving the cardboard box C a predetermined distance forward to move it away from the guide  70 . In this case, the box packing device  10  next moves the cardboard box C downward along the up and down direction, thereafter rotates the cardboard box C a predetermined angle again to return the posture of the cardboard box C to what it was before, and thereafter moves the cardboard box C a predetermined distance rearward to bring it closer to the guide  70 . 
     REFERENCE SIGNS LIST 
     
         
           10  Box Packing Device 
           30  Retention Mechanism 
           40  Rotation Mechanism 
           41  Servo Motor 
           50  Push-in Mechanism 
           60  Shutter 
           70  Guide 
           100  Control Unit 
         Op Opening 
         C Cardboard Box (Box) 
         A Article