Patent Publication Number: US-2010115886-A1

Title: Boxing device and packaging device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This national phase application claims priority to Japanese Patent Application Nos. 2006-261586 and 2006-261587 both filed on Sep. 26, 2006. The entire disclosures of Japanese Patent Application Nos. 2006-261586 and 2006-261587 are hereby incorporated herein by reference. 
     1 Technical Field 
     The present invention relates to a boxing device that packs a predetermined weight or a predetermined number of articles in a box by collecting a plurality of articles as a group and gathering a plurality of such groups. In addition, the present invention relates to a packaging device that packages a plurality of articles whose weights are known in a packaging material. 
     2. Background Art 
     As a boxing device that packs a predetermined weight or a predetermined number of articles in a box, technology to improve the adequacy of the weight of articles to be packed in a box has been proposed, in which the weights of individual articles are measured and a combination of articles having a target weight is attained based on the measured weights (for example, see Japanese Laid-Open Patent Application Publication No. H2-109826). 
     Incidentally, with a type of boxing device that packs a predetermined weight or a predetermined number of articles in a box by collecting some of articles to be packed as a group and gathering a plurality of such groups, there are cases where an article gets stuck while being conveyed before being added to a group and therefore does not reach a predetermined position, and where articles grouped together fall apart because the articles are bag-shaped or the like. In such cases, a predetermined weight or a predetermined number of articles are not put in a box. Therefore, the gross weight is checked after box packing is completed in order to confirm the adequacy of the weight (number) of articles packed in the box. 
     DISCLOSURE OF THE INVENTION 
     However, when the gross weight is checked after box packing is completed and the weight (number) of the articles packed in the box is turned out to be inadequate, the whole box with the articles packed therein needs to be eliminated from the production line, causing a decrease in production efficiency. In addition, when the total number of articles to be packed in one box is large and variations in the weights of individual articles are accumulated, it is not possible to distinguish whether an error in the weight of the whole box is caused by missing of some articles or by the variations in the weights of the individual articles, and thus any box having such an inadequate weight had to be regarded uniformly as a defective and eliminated from the production line. 
     In view of such situation, an object of the present invention is to provide a boxing device that packs a predetermined weight or a predetermined number of articles in a box by collecting a plurality of articles as a group and gathering a plurality of such groups, in which the weight (number) of the group to be packed in a box is checked after the weights of individual articles are obtained and before these articles are packed in a box in order to prevent a reduction in production efficiency. 
     Further, when the packaging material used for packaging is a cardboard container or a recyclable container, the weight thereof may greatly change due to the humidity, aged deterioration, and other reasons, and therefore the range of the change in the weight of the packaging material may be greater than the weight of each article. Consequently, because of the change in the weight of the packaging material, there has been a case, for example, where the weight of packaged articles is erroneously determined to be adequate even when some of a plurality of articles to be packaged were left out before being packaged and therefore are not included in the packaging material. In other words, even when the gross weight with tare included is checked after packaging is completed, it has not been possible to confirm the adequacy of the weight (number) of articles themselves that are packaged. 
     In view of such situation, another object of the present invention is to provide a packaging device that packages a plurality of articles whose weights are known in a packaging material, in which the gross weight with tare included is checked after packaging is completed, thereby allowing to confirm the adequacy of the weight (number) of articles that are packaged. 
     A boxing device according to a first aspect of the present invention includes a collecting unit, a group weight measuring unit, a determination unit, and a boxing unit, and adapted to pack a predetermined weight or a predetermined number of articles in a box. The collecting unit is configured and arranged to collect articles as a group. The group weight measuring unit is configured and arranged to measure a weight of the group. Based on the weight measured by the group weight measuring unit, the determination unit is configured and arranged to determine whether or not the group of the articles is appropriate to be packed in the box. The boxing unit is configured and arranged to pack, in the box, a plurality of the groups of the articles determined by the determination unit to be appropriate to be packed in the box. 
     A boxing device according to a second aspect of the present invention is the boxing device according to the first aspect of the present invention, further including an individual weight measuring unit. The individual weight measuring unit is configured and arranged to measure a weight of each of the articles. The individual weight measuring unit is positioned on the upstream side of the group weight measuring unit. 
     A boxing device according to a third aspect of the present invention is the boxing device according to the first or second aspect of the present invention, further including a replenishment unit. The replenishment unit has a stocking area for stocking the articles. In addition, the replenishment unit is configured and arranged to replenish, when the group of the articles is determined by the determination unit to be not appropriate to be packed in the box because of a shortage in the number of the articles, the shortage with the article stocked in the stocking area. 
     A packaging device according to a fourth aspect of the present invention includes a tare weight obtaining unit, a packaging unit, and a weight checking unit. The tare weight obtaining unit is configured and arranged to obtain a weight of a packaging material. The packaging unit is configured and arranged to package a plurality of articles whose weights are known in the packaging material. The weight checking unit is configured and arranged to check a weight of the plurality of articles packaged in the packaging material, using a sum of the weight obtained by the tare weight obtaining unit and the known weights of the articles as a reference. 
     A packaging device according to a fifth aspect of the present invention includes a tare weight obtaining unit, a packaging unit, a gross weight measuring unit, and a determination unit. The tare weight obtaining unit is configured and arranged to obtain a weight of a packaging material. The packaging unit is configured and arranged to package a plurality of articles whose weights are known in the packaging material. The gross weight measuring unit is configured and arranged to measure a weight of the plurality of articles packaged in the packaging material. The determination unit is configured and arranged to determine whether or not the plurality of articles are adequately packaged in the packaging material based on a sum of the weight obtained by the tare weight obtaining unit and the known weights of the articles, and the weight measured by the gross weight measuring unit. 
     A packaging device according to a sixth aspect of the present invention is the packaging device according to the fourth or fifth aspect of the present invention, wherein the tare weight obtaining unit is configured and arranged to measure the weight of the packaging material. 
     A packaging device according to a seventh aspect of the present invention is the packaging device according to the fourth or fifth aspect of the present invention, wherein the packaging material has a storage medium in which the weight of the packaging material is stored. The tare weight obtaining unit is configured and arranged to read the weight of the packaging material stored in the storage medium. 
     A packaging device according to an eighth aspect of the present invention is the packaging device according to any one of the fourth through seventh aspects of the present invention, wherein the packaging unit is configured and arranged to package the articles in a cardboard container as the packaging material. 
     A packaging device according to a ninth aspect of the present invention is the packaging device according to any one of the fourth through eighth aspects of the present invention, wherein the packaging unit is configured and arranged to package the articles in a recyclable container as the packaging material. 
     The first aspect accomplishes a beneficial effect as follows. Because the weight of a group of articles is measured and the adequacy of the weight (number) of the articles to be packed in a box is determined based on the measured weight, it is possible to detect problems such as a defective article and the like before box packing is performed and take an appropriate countermeasure. As a result, the present invention is more efficient than the conventional boxing device that determines the adequacy of the weight (number) after box packing is completed and eliminates a whole box in which a problem is found from the production line. In addition, even when a total number of the articles to be packed in one box is large and variations in the weight of each article are multiply added, it is possible to prevent a box whose weight turned out to be significantly different due to the variations in the weight of each article from being regarded as a defective box because the articles to be packed in the box are separated into a plurality of groups and the weight is checked for each group having a small number of bags. 
     The second aspect accomplishes a beneficial effect as follows, in addition to the effect accomplished by the first aspect. Because the weight of each individual article is actually measured, it is possible to more accurately determine the weight of a group of articles. 
     The third aspect accomplishes a beneficial effect as follows, in addition to the effects accomplished by the first and second aspects. When it is determined that there is a shortage in the number of articles, the shortage of the articles is automatically replenished. Therefore, even when an article to be packed in a box is left out, it is possible to maintain good productivity. 
     The fourth through ninth aspects accomplish beneficial effects as follows. Because the sum of the known weights of the plurality of articles to be packed and the weight measured by the tare weight obtaining unit is used as a reference when checking the weight of the plurality of articles packaged in the packaging material, even when the tare weight significantly changes due to the humidity, aged deterioration, and other reasons, it is possible to confirm the adequacy of the weight (number) of the articles that are packaged by checking the gross weight with tare included after packaging is completed. In particular, even when the packaging material is made of cardboard (made of paper) that is highly hygroscopic and the weight easily changes due to the effect of humidity, or even when the packaging material is a recyclable container and there is a concern for the change in the weight due to long-term use, the adequacy of the weight or the number of the articles that are packaged is guaranteed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic side elevational view of a boxing device according to an illustrated embodiment of the present invention. 
         FIG. 2  is a schematic top plan view of the boxing device according to the illustrated embodiment of the present invention. 
         FIG. 3  is a function block diagram of the boxing device according to the illustrated embodiment of the present invention. 
         FIG. 4  is a perspective view of one example of boxed products produced by the boxing device according to the illustrated embodiment of the present invention. 
         FIG. 5  is an enlarged side elevational view of a thickness detection unit of a seal checker coupled to the boxing device according to the illustrated embodiment of the present invention. 
         FIG. 6  includes schematic top plan views (a) to (c) describing the operation of a stock unit of the boxing device according to the illustrated embodiment of the present invention. 
         FIG. 7  is a schematic front elevational view of a collecting unit of the boxing device according to the illustrated embodiment of the present invention. 
         FIG. 8  includes schematic side elevational views (a) to (c) describing the operation of a boxing/sealing unit of the boxing device according to the illustrated embodiment of the present invention. 
         FIG. 9  is a flowchart for a determination process flow based on the bag thickness executed in a control unit of the boxing device according to the illustrated embodiment of the present invention. 
         FIG. 10  is a flowchart for a determination process flow based on the bag weight executed in the control unit of the boxing device according to the illustrated embodiment of the present invention. 
         FIG. 11  is a flowchart for an alternative example of the determination process flow based on the bag thickness executed in a control unit of the boxing device according to the illustrated embodiment of the present invention. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Below, a boxing device (packaging device)  100  according to an embodiment of the present invention is described with reference to the drawings.  FIG. 1  is a schematic side elevational view of the boxing device  100 ,  FIG. 2  is a schematic top plan view thereof, and  FIG. 3  is a function block diagram thereof.  FIG. 4  is a perspective view of one example of boxed products produced by the boxing device  100 . 
     Overview of Boxing Device in Illustrated Embodiment 
     The boxing device  100  according to this embodiment is a packaging device that collects, as a group G, a plurality (6) of individual bags (articles) B sequentially supplied from a bag-manufacturing and packaging apparatus (not shown) in the upstream process, and repeatedly packs a plurality (2) of groups G of bags in a box C of a defined size. With this device, as shown in  FIG. 4 , a predetermined number (6 pieces×2 lines=12 pieces in total) of the bags B are packed in the box C, and the opening of the box is sealed by a tape or the like. The box C as a packaging material is a cardboard container and is also a recyclable container that can be collected at the destination of delivery and reused. 
     As shown in  FIGS. 1 and 2 , the boxing device  100  includes an individual weight checker  1  (individual weight measuring unit), a seal checker  2 , a defective bag sorting unit  3 , a stock unit  4 , a collecting unit  5 , a group weight checker  6  (group weight measuring unit), a boxing/scaling unit  7  (boxing unit, packaging unit), a gross weight checker  8  (gross weight measuring unit), and a defective box sorting unit  9 , which are arranged in that order from the upstream process side (left side in the figures). These components are controlled by a control unit  10  (determination unit, weight checking unit) shown in  FIG. 3 . The control unit  10  includes a CPU (central processing unit)  101 , a ROM (read-only memory)  102 , and a RAM (random-access memory)  103 . The CPU  101  transmits a control signal to each unit of the boxing device  100  and also executes, on the RAM  103 , a program to perform calculation, determination, and selection processes based on an information signal that the control unit  10  receives from each unit of the boxing device  100 . Note that the control unit  10  includes a touch panel display  20  and a keyboard  30 , which are connected thereto, and which respectively serve as a display unit that displays the device operating condition and the like and an operation inputting unit that is used for setting various setting values and for inputting operations. 
     Individual Weight Checker  1   
     The individual weight checker  1  is the individual weight obtaining unit configured and arranged to obtain a weight w n  of each individual bag B while sequentially conveying the individual bags B, which are continuously supplied from the upstream process, to the downstream side at a predetermined speed. Specifically, a transport conveyor  11  that receives the individual bags B supplied and conveys the same to the downstream side, and a weighing transport conveyor  12  that measures, by a load cell  12   a,  the weight w n  of each individual bag B discharged from the transport conveyor  11  and that conveys the same to the downstream side are arranged in line. Based on a weight information signal received from the load cell  12   a,  the control unit  10  determines whether or not the weight w n  of the individual bag B is within a predetermined weight range (upper weight limit w U , lower weight limit w L ). When the weight w n , of the individual bag B is outside the predetermined weight range, the control unit  10  discharges the bag B as a defective product to the outside of the process by the defective bag sorting unit  3  (described later). In addition, in order to determine the adequacy of the weight or the number of the individual bags B included in the group G of bags (i.e., that there are no bags that are left out from the group G of bags and the like) based on a weight Wg of the group G of bags measured by the group weight checker  6  in the downstream process, the control unit  10  calculates, in advance, a group weight W 2  of such group G of bags, by adding the weights w n  of the plurality of bags B included in that group G of bags whose weight Wg is measured by the group weight checker  6 . 
     Seal Checker  2   
     The seal checker  2  is a thickness detection unit configured and arranged to apply pressure on each individual bag B in a thickness direction thereof and detects a thickness d n  of the individual bags B at the time of pressure application, while sequentially conveying the individual bags B continuously supplied from the individual weight checker  1  to the downstream side at a predetermined speed. The seal checker  2  is used for a determination of the adequacy of sealing of the individual bags B based on the thickness. Specifically, the seal checker  2  includes a transport conveyor  21  that conveys, to the downstream side, the individual bags B continuously supplied from the individual weight checker  1  in the upstream process; a bag leveling unit  22  that applies pressure using a pressing member  221  to each individual bag B conveyed on the transport conveyor  21  to level out the entire individual bag to a uniform thickness; and a thickness detection unit  23  that applies pressure, using a pressing member  231  driven by a servo motor  233 , to the individual bag B whose thickness is leveled out by the bag leveling unit  22 , detects a thickness d n  of the individual bag based on the angular displacement of the servo motor  233 , and transmits a thickness information signal. 
     As shown in  FIG. 5 , the thickness detection unit  23  includes the pressing member  231  disposed so as to cover the conveying surface of the transport conveyor  21  from above; L-shaped parallel links  232  that are pivotally supported on the lateral side of the transport conveyor  21  and support the pressing member  231  such that the pressing member  231  can move closer to and away from the transport conveyor  21 ; and the servo motor  233  that moves the pressing member  231  closer to and away from the transport conveyor  21  by pivotally driving the parallel links  232 . At the timing when the individual bag B passes through below the pressing member  231 , the servo motor  233  is driven in a direction indicated by the arrow in  FIG. 5 , and thereby the thickness of the individual bag B can be detected. Note that a plurality of rollers  231   a  is disposed on the lower surface of the pressing member  231  in order to allow the individual bag B subject to pressure to smoothly pass through. As is the same with the thickness detection unit  23 , the bag leveling unit  22  includes the pressing member  221  disposed with a plurality of rollers on its lower surface, which is supported by parallel links  222  ( FIG. 2 ). By pivoting the parallel links  222  at a predetermined torque, the individual bag B that passes through below the pressing member  221  is leveled out and the thickness of the entire bag is made uniform. 
     Here, based on the thickness information signal received from the thickness detection unit  23 , the control unit  10  determines whether or not the thickness d n  of each individual bag B is within a predetermined thickness range (upper limit d U , lower limit d L ). When the thickness d n  of the individual bag B is outside the predetermined thickness range, it may be due to an air leakage due to sealing failure or an excess or deficiency in the amount of charged air. Thus, the control unit  10  transmits a control signal to the defective bag sorting unit  3  in the downstream process so as to discharge such individual bag B as a defective product to the outside of the process. In addition, as a calculation unit configured and arranged to add up the thicknesses d n  of a plurality of individual bags B that are collected as a group G of bags by the collecting unit  5  in the downstream process in order to calculate a thickness d of the group G of bags, the control unit  10  serves as the determination unit configured and arranged to determine, in advance, whether or not it is adequate to pack the group G of bags in the box C of the defined size based on a result of the addition. 
     Defective Bag Sorting Unit  3   
     When it is determined by the control unit  10  that the weight w n  of the individual bag B obtained by the individual weight checker  1  is outside the predetermined weight range, or when it is determined by the control unit  10  that the thickness d n  of the individual bag B detected by the seal checker  2  is outside the predetermined thickness range, the defective bag sorting unit  3  discharges such individual bag B to the outside of the process based on the control signal from the control unit  10 . Specifically, an air jet nozzle (not shown) is disposed on the lateral side of a transport conveyor  31 , and thereby a defective bag that passes through on the transport conveyor  31  is blown out in a direction orthogonal to the conveying direction. Note that when the weight of the individual bag B is large and cannot be easily discharged by the air jet, the individual bag B may be pushed out to the side by an elastic cylinder or the like. 
     Stock Unit  4   
     As shown in  FIGS. 2 and 6 , the stock unit  4  includes a plurality (2) of pairs of slide rails  41  and  42  extending in a direction orthogonal (transverse direction) to the conveying direction of the individual bag B on the conveyor; a plurality (3) of lines of the transport conveyors  43 - 43  and  44 - 44  respectively supported by the slide rails  41  and  42  and arranged in the transverse direction; and a drive unit (not shown) that moves the transport conveyors  43 - 43  and  44 - 44  along the slide rails  41 ,  42 . As shown in  FIG. 6(   a ), except for one line of the transport conveyor  43  and one line of the transport conveyor  44  which serve as a passageway for connecting the upstream process to the downstream process, the plurality of lines of the transport conveyors  43 - 43  and  44 - 44  respectively have spare individual bags B S1-S4  stocked therein. As is the case with other individual bags B, the spare individual bags B S1-S4  are the bags that have passed through the individual weight checker  1  and the seal checker  2  and whose weights and thicknesses are known. The known data are stored by the control unit  10  in a manner associated with the transport conveyors each having the relevant individual bags stocked therein. 
     When the thickness of the group G of bags (=a sum of the thicknesses of a plurality of individual bags B G1-G6  that constitute a group) that are collected by the collecting unit  5  is too large (or too small) and it is determined in advance that it is inadequate to pack such group in the cardboard box C of the defined size, the stock unit  4  selects an individual bag B Gn  to be replaced from the group G of bags and discharges it. At the same time, as an individual bag to be added to the group G of bags, the stock unit  4  selects an individual bag from the spare bags B S1-S4 , whose thickness is smaller (or larger) than the individual bag B Gn  to be replaced and with which the thickness of the group G of bags can be corrected to be within the predetermined range, and inserts the bag to the group. As a selection unit, the control unit  10  selects an individual bag B Gn  to be replaced and a bag B sn  to be added to the group G of bags instead thereof. However, with this boxing device  100 , a sum of the thickness of the group G of bags is identified after the last individual bag B G6  among the plurality of individual bag B G1-G6  which constitute the group G of bags passes through the seal checker  2 , i.e., at the time when the state shown in  FIG. 6(   a ) is reached. Thus, it is substantially difficult to retrieve any one of the individual bag B G1-G5  from the group G of bags and select any one of the spare individual bags B S1-S4  instead thereof to insert the spare to the group. Therefore, the last individual bag B G6  in the group G of bags is always selected as the individual bag B to be replaced. 
     Here, for example, when the individual bag B S1  among the spare individual bags B S1-S4  is selected as the individual bag B to be added instead of the individual bag B G6  to be replaced, first, as shown in  FIG. 6(   b ), after the individual bag B G6  to be replaced is taken onto the transport conveyor  43 , as shown in  FIG. 6(   c ), the plurality of lines of the transport conveyors  43  are transversely slid in order to change the position of the conveyors. Thereby, the selected individual bag B S1  is supplied downstream and added to the group G of bags. The individual bag B G6  that is replaced is stocked in the transport conveyor  43  instead of the individual bag B S1  that is added. Further, the data of the weight and thickness detected by the individual weight checker  1  and the seal checker  2 , respectively, are stored by the control unit  10  in a manner associated with the conveyor on which the individual bag B G6  is placed. Note that when the thickness of the group G of bags is determined to be inadequate to be packed in the box C although any one of the spare individual bags B S1-S4  is added and inserted instead of the individual bag B G6  that is replaced, the control unit  10  transmits to the touch panel display  20  a control signal to display a warning that the group is inadequate to be packed in the box, instead of replacing or adding an individual bag. Then, when such group G of bags reaches the group weight checker  6 , the control unit  10  transmits to a discharge member (described later) a control signal to discharge the group G of bags to the outside of the process. Note that a control signal to stop the device may be transmitted instead of or together with displaying a warning and discharging a group of bags. 
     Here, in view of the balance between the installation space of the stock unit  4  and the timing to change the position of the conveyors, the transport conveyors are set in 2 pairs×3 lines: however, the same number (4) of spare bags can be secured even with 1 pair×5 lines or 4 pairs×2 lines of the transport conveyors. Further, the number of spare individual bags B sn  may be increased by additionally installing a slide rail or a conveyor. By so doing, the occurrence of the situation where a group G of bags must be discharged as described above is reduced, improving process efficiency. In addition, when a conveyor like the transport conveyor  31  is additionally installed between the seal checker  2  and the stock unit  4 , it is possible to arrange more individual bags B in a standby manner in front of the stock unit  4 , and thus the B G1-G5  in addition to the B G6  can be subject to replacement. 
     Collecting Unit  5   
     The collecting unit  5  is a device that receives individual bags sequentially supplied from the upstream process and collects them as the group G of bags in a state capable of being packed in a box. As shown in  FIG. 7 , the collecting unit  5  includes a receiving unit  51  that receives the individual bags B from the upstream process and a holding unit  52  that holds the individual bags B received by the receiving unit  51 , in a state of being collected in the thickness direction. The receiving unit  51  includes a rotor  511  that is rotated about a rotation axis  511  a extending in a horizontal direction by a driving source (not shown), and a plurality (4) of receiving trays  512  that are disposed at predetermined intervals in a circumferential direction of the rotor  511  and that are rotatably supported by a rotation axis  512   a.  The receiving trays  512  are configured so as to move along a rotation path as shown by the dashed-dotted line along with the rotation of the rotor  511 . Thereby, each receiving tray  512  receives the bag B supplied in a lying position at a position P 1  shown in  FIG. 7  and supplies the bag B in a standing position to the holding unit  52  at a position P 2 . 
     The holding unit  52  includes a plurality of pairs of sandwich structures  522  on the conveying surface of a transport conveyor  521 , which sandwich, from the both sides, the group G of bags in a collected state in the thickness direction, and each sandwich structure  522  includes two sandwich members  522   a,    522   b  disposed with a space therebetween which corresponds to the thickness of the group G of bags. The two sandwich members  522   a,    522   b  move in the conveying direction. The sandwich member  522   a  moves while supporting the bags B sequentially supplied in the standing position from the receiving unit  51 . After the group G of bags is collected, the sandwich member  522   b  holds the group G of bags from behind to sandwich the same with the sandwich member  522   a.  Then, keeping the state the way it is, they move to a bag delivery position (position P 3  in  FIG. 7 ) where the bags B are delivered to the group weight checker  6  in the downstream process. When the group G of bags is moved to the bag delivery position, the group G of bags is pushed out to the front by a pushing member (not shown) arranged at a position corresponding to the position P 3 , and is supplied to a tray  61  of the group weight checker  6 . 
     Group Weight Checker  6   
     The group weight checker  6  is the group weight obtaining unit configured and arranged to receive the group G of bags supplied from the collecting unit  5  in the upstream process and to obtain the weight Wg of the group G of bags by measuring by a load cell  61   a  disposed at the lower portion of the tray  61 . The group weight checker  6  includes a boxing member (not shown) that pushes the group G of bags in the horizontal direction into the box C set in the boxing/sealing unit  7  in the downstream process, and the discharge member (not shown) that discharges the group G of bags by pushing out to the outside of the process. As described above, the control unit  10  adds up the weights w n  of the individual bags B included in the group G of bags and calculates, in advance, the group weight W 2 , which is the sum of the addition. Based on this sum and the weight Wg, the control unit  10  determines the adequacy of the weight or the number of the individual bags B included in such group G of bags. 
     When the group weight W 2  is equal to the measured weight Wg, the control unit  10  determines that the weight or the number of the individual bags B included in such group G of bags is adequate and also transmits a control signal to the above described boxing member so as to pack the group G of bags in the box C. In addition, when the group weight W 2  is not equal to the measured weight Wg, the control unit  10  determines that the weight or the number of the individual bags B included in such group G of bags is not adequate, i.e., that accidents such as that all or some of the individual bags in the group G of bags are left out in the course of the process and the like occurred. The control unit  10  also transmits a control signal to the above described discharge member so as to discharge the entire group G of bags to the outside of the process. 
     Boxing/Sealing Unit  7   
     The boxing/sealing unit  7  sets the empty box C in a state in which the box C is opened toward the group weight checker  6 ; and includes a boxing table  71  whose height is variable according to the number of lines (rows) of the groups G of bags pushed in from the group weight checker  6  and a sealing device  72  that seals the box C in which a predetermined number of rows of the groups G of bags are packed by the boxing table  71 . In order to allow the height of the boxing table  71  to be variable according to the number of rows of the groups G of bags to be pushed in, the boxing table  71  is disposed with a base  711  and a lifting and lowering table  712  disposed to be capable of moving upward and downward with respect to the base  711 . When the bags G on the first row are packed in the box, as shown in  FIG. 8(   a ), the lifting and lowering table  712  adjusts the lower surface of the box C that is set to the same height as the tray  61  of the group weight checker  6 . When the bags G on the second row and the followings are packed in the box, as shown in  FIG. 8(   b ), the lifting and lowering table  712  lowers by the height of the group G of bags at a time and moves the box C downward to a position where the bags G on the second row and the followings can be received. 
     Therefore, the predetermined number of rows of the bags G are packed in the box as shown in  FIG. 8(   c ) simply by being pushed in the horizontal direction by the boxing member of the group weight checker  6 . The box C in which box packing is completed is moved to the sealing device  72 , and the opening of the box C is closed by a cover by the sealing device  72  as shown in  FIGS. 8(   a ) and ( b ). Then, the box C is moved by a transport conveyor  721  to the gross weight checker  8  in a next process. Note that the box C is set in the boxing table  71  by a weighing transport conveyor  73  ( FIG. 2)  equipped with a load cell, and at that time, as a tare weight obtaining unit, the weighing transport conveyor  73  measures and obtains a weight (tare weight) W p  of the box C in an empty state, and transmits the weight information signal to the control unit  10 . 
     Gross Weight Checker  8   
     The gross weight checker  8  is a weighing transport conveyor equipped with a load cell  8   a.  As a conveying unit, the gross weight checker  8  conveys the box C supplied from the boxing/sealing unit  7  to the downstream process, and as the gross weight obtaining unit, the gross weight checker  8  measures and obtains a weight W h  of the packaging material and a predetermined number of individual bags B packaged in the packaging material, and transmits the weight information signal to the control unit  10 . The control unit  10  calculates a sum of the addition of that gross weight W 1  of the predetermined number of rows of groups G of bags which is obtained from the weights Wg measured by the group weight checker  6  and the tare weight W p  measured by the weighing transport conveyor  73 , and this sum is used as a reference for the weight check of the plurality of individual bags B packaged in the packaging material. In other words, when the sum of the known gross weight W 1  and the tare weight W p  is equal to the weight W h  measured by the gross weight checker  8 , it is determined that all the individual bags B are adequately packaged in the box C. When they are not equal to each other, it is determined that some of the individual bags B are left out or the like and not adequately packaged. Based on such determination, the control unit  10  transmits a control signal to the defective box sorting unit  9 . 
     Defective Box Sorting Unit  9   
     The defective box sorting unit  9  is a transport conveyor. The defective box sorting unit  9  conveys the box C in which the individual bags B are adequately packaged to a next process based on the control signal from the control unit  10 , and at the same time operates an elastic cylinder (not shown) disposed on the lateral side of the transport conveyor to discharge the box C, in which the individual bags B are not adequately packaged, to the outside of the process. 
     Determination Process Flow by Control Unit  10   
     Next, a determination process flow by the control unit  10  in the boxing device  100  configured as described above is described. Principally, the control unit  10  integrally and simultaneously performs a determination process regarding the thickness of the individual bag B and the thickness of the group G of bags which is obtained as the sum of thicknesses of the individual bags B, and another determination process regarding the weight of the individual bag B, the weight of the group G of bags, and the weight of the packaging material in which the predetermined number of rows of the bags G are packaged: however, for the sake of simplicity of description, these determination process flows are described separately. 
     Determination Process Flow Based On Bag Thickness 
       FIG. 9  shows a determination process flow that is performed based on the bag thickness. Before operating the boxing device  100 , as data necessary to the determination process by the control unit  10 , it is required to set and input the size (width dimension D) of the box C that is used, the number N of the individual bags B included in one row (group), and the upper limit d U  and the lower limit d L  of the thickness dimension of the individual bag B (steps A 1  to A 3 ). When the boxing device  100  starts operation, first, initial values of the number n of the individual bags B added to the group G of bags and a thickness sum d of these individual bags B are reset to zero (steps A 4  and A 5 ). Next, a thickness d n  of the individual bag B is detected by the seal checker  2  (step A 6 ) to determine whether or not it is within the predetermined thickness range (step A 7 ). When the thickness d n  of the individual bag B is within the predetermined thickness range, the thickness d n  of such individual bag B is added to the thickness sum d of the group (step A 8 ), the number n of the individual bags B added is counted (step A 9 ), and this process is repeated until the number N set in step A 2  is reached (step A 10 ). Note that when the thickness d n  of the individual bag B is not within the predetermined thickness range, the thickness d n  of such individual bag B is not added to the thickness sum d. Instead, such individual bag B is discharged to the outside of the process (step A 11 ), and the thickness d n  of a next individual bag B is detected (step A 6 ). 
     When the number of the individual bags B whose thicknesses are added reaches the number N, whether or not it is adequate to pack the group G of bags in the box C is determined. Specifically, whether the thickness sum d of the group G of bags is too small (step A 12 ) or large (step A 13 ) compared to the width dimension D of the box C is determined. A value  8  in step A 12  is selected based on the width dimension D of the box C, the number N of bags in a group G, and the like, and it is an empirical value that indicates a possible occurrence of damage of a bag and a pinhole when the difference between the width dimension D and the bag thickness sum d (space between the box C and the group G of bags) is greater than the value  8 . When it is determined that the thickness of the group G of bags is adequate for packing in the box C, such bags G of the first row are packed in the box (step A 14 ). When it is determined to be inadequate, a determination is made as to whether or not there is an individual bag B having the thickness with which the thickness of the group G of bags can be corrected to be within the predetermined range, among the plurality of spare bags B stocked in the stock unit  4  (step A 15 ). 
     When it is determined in step A 15  that there is such an individual bag B, the bag B to be replaced is discharged from the group G of bags to the stock unit  4 . At the same time, the individual bag B to be added is selected from the stock unit  4  and inserted to the group G of bags. On the other hand, when it is determined that there is no such an individual bag B, a warning that such group G of bags is inadequate to be packed in the box is displayed on the touch panel display  20  (step A 17 ), and such group G of bags is discharged to the outside of the process when reached the group weight checker  6  (step A 18 ). Thereafter, the determination process after step A 4  is repeated until the boxing device  100  is stopped. 
     Determination Process Flow Based On Bag Weight 
       FIG. 10  shows the determination process flow performed based on the bag weight. Before operating the boxing device  100 , as data necessary to the determination process by the control unit  10 , it is required to set and input the number K of rows (lines) of the groups G of bags to be packed in the box C, the number N of the individual bags B included in one row (group), and the upper limit w U  and the lower limit w L  of the weight of the individual bag B (steps B 1  to B 3 ). When the boxing device  100  starts operation, first, initial values of the gross weight W 1 , a counter k for the number of rows, the group weight W 2 , and the bag number counter n are reset to zero (steps B 4  to B 7 ). Next, the weight w n  of the individual bag B is detected by the individual weight checker  1  (step B 8 ) and whether or not it is within the predetermined weight range is determined (step B 9 ). When the weight w n  of the individual bag B is within the predetermined weight range, the weight w n  of such individual bag B is added to the group weight W 2  (step B 10 ), the number n of the individual bags B added is counted (step B 11 ), and this process is repeated until the number N set in step B 2  is reached (step B 12 ). Note that when the weight w n  of the individual bag B is not within the predetermined weight range, it is not added to the group weight W 2 . Instead, such individual bag B is discharged to the outside of the process (step B 13 ), and the weight w n  of a next individual bag B is detected (step B 8 ). 
     When the number of the individual bags B whose weights w n  are added reaches the number N, the weight Wg of the group G of bags is detected by the group weight checker  6  (step B 14 ), and whether or not the weight Wg is equal to the group weight W 2  is determined (step B 16 ). When they are equal to each other, such group of bags is packed in the box (step B 17 ), the number k of rows to be packed in the box is counted (step B 18 ), the weight Wg is added to the gross weight W 1  (step B 19 ), and this process is repeated until the number K of rows set in the step B 1  is reached (step B 20 ). Note that when the group weight W 2  is not equal to the weight Wg, such group G of bags is discharged to the outside of the process (step B 13 ), and the process for a new group G of bags is started (step B 6 ). 
     When the number k of rows to be packed in the box reaches the set number K, the weight W h  of the whole box is detected by the gross weight checker  8  (step B 22 ), and whether or not the weight W h  is equal to the sum of the gross weight W 1  and the tare weight W p  (measured in advance by the weighing transport conveyor  73 ) is determined (step B 23 ). When it is determined that they are equal to each other, such box C is conveyed to a next process (step B 24 ); and when it is determined that they are not equal to each other, such box C is discharged, as a defective product, to the outside of the process (step B  25 ). Thereafter, the determination process after step B 4  is repeated until the boxing device  100  is stopped. 
     Characteristics of Boxing Device In Illustrated Embodiment 
     As a result of the above described configuration, the boxing device  100  according to this embodiment has the following characteristics. 
     First, the boxing device  100  according to this embodiment includes the thickness detection unit (seal checker  2 ) to detect the thickness d n  of the each of individual bags B, and the calculation unit (control unit  10 ) to add the thicknesses d n  of individual bags B detected by the thickness detection unit before the group G of bags, which is formed by collecting a plurality of individual bags B to be packed in the box C of the defined size, is packed in the box. Therefore, it is possible to detect, in advance, a possibility of occurrence of problems such as breakage of a bag during box packing, formation of a pinhole in the course of conveyance after box packing, and the like. 
     Second, the boxing device  100  according to this embodiment includes the determination unit (control unit  10 ) to determine whether or not it is adequate to pack the group G of bags in the box C of the defined size based on the result of addition by the calculation unit. Therefore, it is possible to take an appropriate countermeasure, based on the determination result, to prevent problems such as breakage of a bag during box packing, formation of a pinhole in the course of conveyance after box packing, and the like. 
     Third, as a characteristic, the boxing device  100  according to this embodiment includes the selection unit (control unit  10 ) that is configured such that when the group G of bags is determined by the determination unit that it is inadequate to be packed in the box C of the defined size, the selection unit selects a bag to be replaced from such group G of bags. Therefore, it is possible to easily take an appropriate countermeasure to prevent problems such as breakage of a bag, a pinhole, and the like. 
     Fourth, the boxing device  100  according to this embodiment includes the stock unit  4  to stock spare individual bags B and the selection unit (control unit  10 ) to select an individual bag B among spare individual bags B, which is to be added to the group G of bags instead of the bag to be replaced. Therefore, it is possible to further easily take an appropriate countermeasure to prevent problems such as breakage of a bag, a pinhole, and the like. 
     Fifth, the boxing device  100  according to this embodiment automatically discharges the bag to be replaced from the group G of bags to the stock unit  4  and automatically inserts a bag to be added instead of the replaced bag from the stock unit  4 . Therefore, occurrence of a broken bag, a pinhole, and the like is reliably prevented, without stopping the device or taking the time of an operator. 
     Sixth, the boxing device  100  according to this embodiment is configured such that when an appropriate countermeasure cannot be taken with a spare individual bag B for the group G of bags determined to be inappropriate to be packed in the box C, the boxing device  100  discharges such group G of bags and issues a warning on the touch panel display  20 . Therefore, even when there is not any appropriate individual bag B in the stock unit  4 , occurrence of a broken bag, a pinhole, and the like is reliably prevented. Note that the device may be stopped along with displaying a warning, instead of discharging the group G of bags. 
     Seventh, the boxing device  100  according to this embodiment serves as the thickness detection unit by utilizing the seal checker  2  to apply pressure to each individual bag B in the thickness direction thereof to detect the bag thickness d n  at the time of pressure application and then determine whether or not the bag is adequately sealed based on the thickness d n . Therefore, it is possible to produce the device at low cost, compared to the case where the thickness detection unit is separately provided. 
     Eighth, the boxing device  100  according to this embodiment includes the individual weight obtaining unit (individual weight checker  1 ) to obtain the weight w n  of the individual bag B; the group weight obtaining unit (group weight checker  6 ) to measure the weight Wg of the group G of bags, which is formed by collecting a plurality of individual bags B to be packed in the box; and the determination unit (control unit  10 ) to determine the adequacy of the weight or the number of articles to be packed in the box based on the weight Wg. Therefore, it is possible to detect problems before box packing and take an appropriate countermeasure. 
     Ninth, the boxing device  100  according to this embodiment is configured such that the individual weight obtaining unit is the individual weight checker  1  disposed on the upstream side of the group weight obtaining unit. Therefore, it is possible to actually measure the weight of each individual bag B and more accurately determine the weight of the group G of bags. 
     Tenth, the boxing device  100  according to this embodiment includes the tare weight obtaining unit (weighing transport conveyor  73 ) that measures the weight W p  of the box C that is a packaging material, and the sum of the known gross weight W 1  and the weight W p  measured by the tare weight obtaining unit is used as a reference for the weight check of the plurality of individual bags B packaged (packed) in the box C. Therefore, even when the tare weight of the box C that is a cardboard recyclable container significantly changes due to the humidity, aged deterioration, and other reasons, it is possible to confirm the adequacy of the weight or the number of the individual bags B that are packaged by checking the actual gross weight W h  with the tare weight W p  included after packaging is completed. As a result, when some of the individual bags B are left out at the time of packaging, it is possible to reliably detect such a situation. In other words, it is possible to determine whether or not a plurality of individual bags (articles) is adequately packaged in the packaging material. 
     Alternative Embodiments 
     According to the above embodiment, the thicknesses d n  of the individual bags B detected by the thickness detection unit are added and whether or not it is adequate to pack the group G of bags in the box C is determined based on the result of the addition and the width dimension D of the box C. However, instead of this arrangement, as shown in  FIG. 11 , the thicknesses d n  of individual bags B may be subtracted one by one from a predetermined value (the width dimension D of the box C), and whether or not it is adequate to pack the group G of bags in the box C may be determined based on the result of subtraction (a remaining space d 1  resulted in the box C). Specifically, the possibility of occurrence of a pinhole and a broken bag is determined in advance depending on whether the remaining space d 1  is too large (step A 12 ) or too small (step A 13 ). 
     According to the above embodiment and the above alternative embodiment, whether or not it is adequate to pack the group G of bags in the box C of the defined size is determined when addition or subtraction from a predetermined value is finished for all of the individual bags B constituting the group G of bags. However, when the number N of the individual bags B included in the group G of bags is large and when most of the individual bags B have the thicknesses d n  close to either the upper limit or lower limit in the predetermined thickness range, it may be possible to determine that the group G of bags is inadequate to be packed in the box C before finishing addition or subtraction for all the individual bags B. For example, when the individual bags B each of which has the thickness close to the upper limit are continuously supplied, even if all the rest of the individual bags B to constitute the group G of bags have thicknesses d n  close to the lower limit, there is a case where these individual bags B do not fit in the remaining space d 1  in the box C and thus cannot be packed therein. 
     In such a case, nothing can be done even with a spare individual bag stocked in the stock unit  4 . Therefore, all the bags in the group G need to be discharged, which may reduce process efficiency. To solve this problem, before addition or subtraction is finished for all of the individual bags B, a check may be performed to determine whether the remaining space is too small even if all the rest of the individual bags B are the ones each of which has the thickness d n  close to the lower limit, or the remaining space is too large even if all the rest of the individual bags B are the ones each of which has the thickness d n  close to the upper limit, and determine whether or not it is adequate to pack the group G of bags in the box C. By so doing, it is possible to take an adequate countermeasure at an early stage, and a reduction in process efficiency is prevented. 
     According to the above embodiment and the above alternative embodiment, when the group weight W 2  is not equal to the weight Wg measured by the group weight checker  6 , such group G of bags is discharged to the outside of the process. However, when the reason for the discrepancy is determined based on the weight Wg, the thickness d, or the like to be a shortage of the number of bags which is caused as some of the individual bags are left out, the shortage may be replenished from the stock unit  4  (replenishment unit). When it is determined that there is a shortage in the number of articles, the amount of the shortage is automatically replenished. Thereby, a high productivity can be maintained. 
     According to the above embodiment and the above alternative embodiment, the weight w n  of the individual bag B is measured by the individual weight checker  1  disposed in the upstream side of the group weight checker  6 . However, a defined weight (for example, the median of a defined weight range) of the individual bag B may be used as the weight w n . Note that, here, when the defined number of individual bags B to be packed in the box is large, variations in the weights of the individual bags B each of which is in the defined weight range are accumulated so that the weight W h  of the whole box may have an error greater than the weight corresponding to one individual bag B. This situation is difficult to be distinguished from the situation where some bags are missing. However, with the present invention, because the individual bags B to be packed in the box are weight-checked on a predetermined small number basis by separating such individual bags B into a plurality of groups each of which has the predetermined small number of bags B, it is possible to reliably prevent from erroneously regarding the variations in the weights of the individual bags B as the occurrence of missing of some bags B. 
     According to the above embodiment and the above alternative embodiment, the packaging material to be used is the box C of the defined size, which is a cardboard recyclable container. However, it is not limited thereto. A container may be formed by a material other than a cardboard. For example, it may be a plastic container, and it may not need to be a recyclable container. In addition, it may be a container having a different shape such as a bag shape other than a box shape. 
     In the above embodiment and the above alternative embodiment, a storage medium (memory device) that stores the weight W p  of the box C may be mounted to the box C, and a transport conveyor having a function to read the tare weight W p  from the storage medium may be disposed instead of the weighing transport conveyor  73 . For example, an IC tag in which the weight W p  of the box C is stored may be attached to the box C, and an IC tag reader may be disposed to the transport conveyor provided instead of the weighing transport conveyor  73 . Alternatively, a barcode (including a QR code) in which the weight W p  of the box C is stored may be attached to the box C, and a bar code reader may be disposed to the transport conveyor provided instead of the weighing transport conveyor  73 . Note that the transport conveyor used instead of the weighing transport conveyor  73  is preferably incorporated into the box-packing process line of the boxing device  100 , in a manner in which the transport conveyor can smoothly perform the process to read the tare weight W p . In addition, the tare weight W p  that is read out is transmitted to the control unit  10 , and thereafter the same process as described in the above embodiment is performed. 
     Additionally, the boxing device of the present invention is not limited to the embodiments described above, and various changes and modifications can be made herein without departing from the scope of the invention.