Abstract:
A general-purpose fluid injecting device is provided that can be used if an air bag is accommodated in a box of a different height. A fluid injecting device is provided that injects a fluid into an air bag through a nozzle projecting from a box the air bag being housed in the box. The device includes a detection apparatus for detecting a height position of the nozzle and a control apparatus for varying the height position of fluid injecting device in accordance with the detection.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a fluid injecting device that injects a fluid from the outside of a box into an air bag accommodated in the box to inflate the air bag so as to allow the air bag to function as a cushioning material. 
   BACKGROUND OF THE INVENTION 
   A fluid injecting device is conventionally known which injects a fluid from the outside of a box into an air bag accommodated in the box to inflate the air bag (the Unexamined Japanese Patent Application Publication (Tokkai-Hei) No. 2002-154579). As shown in  FIG. 14 , the fluid injecting device has an article loading station  101 , a banding station  102 , and a fluid supply station  103  provided along a conveying line  100 . An empty box  104  is conveyed from upstream of the article loading station  101 . Then, in the article loading station  101 , an article  105  is loaded into the box  104 . Subsequently, as shown in  FIG. 15 , an air bag  107  is placed on the article  105 ; a nozzle  106  has been installed in the air bag  107 . On this occasion, the air bag is installed so that the nozzle  106  projects out of the box  104 . 
   Then, in the banding station  102 , as shown in  FIG. 16 , a cover  108  is placed on the box  104  to close it. The box  104  is then tied with a band  109 . 
   Then, in the fluid supply station  103 , a fluid is injected into the air bag  107  through the nozzle  106  to inflate the air bag  107 . The air bag  107  thus functions as a cushioning material in the box  104 . 
   After the operation of injecting air into the air bag  107  is completed, the nozzle  106  is removed. 
   However, the prior art fluid injecting device can be used only if the nozzle is set at the same height in the box, that is, only if the box has the same height. Accordingly, the prior art fluid injecting device has poor general purpose properties. Thus, a fluid injecting device has been desired which is applicable to the case in which the air bag is accommodated in a box of a different height. 
   SUMMARY OF THE INVENTION 
   The present invention is made to solve the above problem of the prior art. It is thus an object of the present invention to provide a general-purpose fluid injecting device that can also be used if an air bag is accommodated in a box of a different height. 
   An aspect of the present invention set forth in Claim  1  provides a fluid injecting device that injects a fluid into an air bag through a nozzle projecting from a box, the air bag being housed in the box, the fluid injecting device being characterized by comprising means for detecting a height position of the nozzle, and control means for varying the height position of the fluid injecting means in accordance with the detection. 
   An aspect of the present invention set forth in Claim  2  provides the fluid injecting device according to Claim  1 , characterized in that the nozzle height position detecting means comprises a sensor that detects a top surface of the box. 
   An aspect of the present invention set forth in Claim  3  provides the fluid injecting device according to Claim  2 , characterized in that the injection of the fluid is ended in accordance with the detection carried out by the sensor. 
   According to the aspect of the present invention set forth in Claim  1 , a fluid can be automatically injected into air bags housed in boxes of various sizes. 
   According to the aspect of the present invention set forth in Claim  2 , not only the effects of the aspect of the present invention set forth in Claim  1  are provided but it is also possible to easily and reliably detect the height position of the nozzle set so as to project from the top of the box. 
   According to the aspect of the present invention set forth in Claim  3 , not only the effects of the aspect of the present invention set forth in Claim  1  are provided but it is also possible to end the injection of the fluid by detecting that the top surface of the box has been inflated. Consequently, the amount of fluid injected can be optimized. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic diagram of the present invention (embodiment of the present invention). 
       FIG. 2  is a sectional view of a box showing its inside (embodiment of the present invention). 
       FIG. 3  is a diagram showing the appearance of the banded box (embodiment of the present invention). 
       FIG. 4  is a diagram showing nozzle height position detecting means (embodiment of the present invention). 
       FIG. 5  is a diagram showing the configuration of a fluid injecting device (embodiment of the present invention). 
       FIG. 6  is a diagram partly showing the configuration of the fluid injecting device (embodiment of the present invention). 
       FIG. 7  is a diagram showing the configuration of the fluid injecting device (embodiment of the present invention). 
       FIG. 8  is a front view of an operation of a gripping device (embodiment of the present invention). 
       FIG. 9  is a perspective view of a presser member and a receiving member (embodiment of the present invention). 
       FIG. 10  is a sectional view of  FIG. 9  (embodiment of the present invention). 
       FIG. 11  is a diagram showing a variation of the nozzle height position detecting means (embodiment of the present invention). 
       FIG. 12  is a perspective view of a variation of the presser member (embodiment of the present invention). 
       FIG. 13  is a side view of  FIG. 12  (embodiment of the present invention). 
       FIG. 14  is a schematic diagram of the configuration of a prior art fluid injecting device (prior art). 
       FIG. 15  is a sectional view of a box in which an article and an air bag are accommodated (prior art). 
       FIG. 16  is a perspective view of the box (prior art) 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The entire configuration of a fluid injecting system will be described with reference to  FIG. 1 . In this figure,  1  is a conveying line. The conveying line  1  is composed of a belt conveyor or the like, and the conveying line  1  conveys a packing box  2  from upstream to downstream (in the drawing, from left to right). 
   An article loading station  3 , a banding station  4 , and a fluid injecting station  5  are arranged at intervals on the conveying line  1  from upstream to downstream. 
   An empty box  2  is conveyed from upstream of the article loading station  3  toward the article loading station  3 . As shown in  FIG. 2 , in the article loading station  3 , an article  6  is loaded into the packing box  2 , and a deflated air bag  7  is placed on the article  6 . A nozzle  8  having a check valve is installed in the air bag  7 . The nozzle  8  is set so as to project out of the box  2 . 
   As shown in  FIG. 3 , in the banding station  4 , a cover  9  is placed on the packing box  2 , and then, an outer periphery of the box  2  is tied with a band  10 . The banding station  4  is provided with a cover setting device (not shown in the drawings) that automatically places the cover  9  on the box  2  and a banding device (not shown in the drawings) that automatically winds the band  10  around the outer periphery of the box  2 . 
   In the fluid injecting station  5 , a fluid is injected into the air bag  7  in the box  2  through the nozzle  8  projects out of the box  2  to inflate the air bag  7 . This allows the air bag  7  to function as a cushioning material for the article in the box  2 . 
   As shown in  FIG. 1 , the fluid injecting device  5  is provided with a nozzle presence detecting means  18  for detecting whether or not the nozzle  8  is attached to the box  2 . The nozzle presence detecting means  18  detects whether or not the nozzle  8  is present in the box  2  conveyed from upstream. The nozzle presence detecting means  18  can also detect whether or not the nozzle  8  remains in the box  2  instead of being removed as described below after a fluid has been completely injected into the air bag  7 . The specific configuration of the nozzle presence detecting means  18  will be described later. 
   Further, as shown in  FIG. 1 , the fluid injecting station  5  is provided with nozzle height position detecting means  20 . The nozzle height position detecting means  20  can detect a top surface of the box  2 , that is, the height position of the top surface of the box  2 , to which the nozzle  8  is attached. 
   As shown in  FIG. 4 , the nozzle height position detecting means  20  can be composed of a light emitting portion  21  and a light receiving portion  22 . The light emitting portion  21  and the light receiving portion  22  are provided above the center of box  2  as shown in  FIG. 4 . The light emitting portion  21  emits a laser beam R to the top surface of the box  2 . The light receiving portion  22  then receives the laser beam R reflected by the box  2 . Then, by measuring the amount of time after the light emitting portion  21  outputs the laser beam R and before the light receiving portion  22  receives the laser beam R, it is possible to measure the distance from the nozzle height position detecting means  20  to the nozzle  8 . 
   Further, the nozzle height position detecting means  20  can detect that the air bag  7  is filled with a fluid. That is, as the fluid is filled into the air bag  7 , the top surface of the bag  2  is pushed up by the air bag  7  as shown by an alternate long and two short dashes line in  FIG. 4 . This reduces the length of optical path of the laser beam R, thus making it possible to detect that the air bag  8  is being filled with the fluid. If the optical path length changes by a predetermined amount, the supply of air from the air supply portion  19  to the nozzle  8  is ended. The nozzle height position detecting means  20  preferably detects the central portion of the top surface of the box  2 . Accordingly, the position of the nozzle height position detecting means  20  may be varied depending on the amount by which biasing means (not shown in the drawings) for biasing the box  2  toward one side of the conveying line  1 . Alternatively, a diffusion type photoelectric sensor or the like may be attached to an elevating and lowering portion, and then, the height position of the nozzle  8  (top surface of the box  2 ) may be detected by elevating or lowering the diffusion type photoelectric sensor. On the other hand, the top surface of the box  2  may not be raised even after a predetermined time has passed since the start of injection of the fluid into the air bag  7 . This makes it impossible to detect that the fluid is filled into the air bag  7 . In this case, a disadvantage such as a hole accidentally formed in the air bag  7  can be detected. 
   As shown in  FIG. 1 , drive-away means  23  is provided downstream of the fluid injecting station  5 . The drive-away means  23  is a device that drives away a box  2  corresponding to an error to a drive-away line A that is different from the regular conveying line  1 . 
   That is, if the detection executed by the nozzle presence detecting means  18  indicates that the nozzle  8  has not been attached to the box  2  conveyed from upstream, the drive-away means  23  determines this to be an error and pushes out and drives away the box  2  to the drive-away line A. Further, if the detection executed by the nozzle height position detecting means  20  indicates that the air bag  7  has not been filled in spite of a predetermined flow of fluid injected into the air bag  7 , the drive-away means  23  determines this to be an error and pushes out and drives away the box  2  to the drive-away line A. Moreover, if the detection executed by the nozzle presence detecting means  18  indicates that after the fluid is filled into the air bag  7 , the nozzle  8 , which would otherwise have been removed from the box  2 , remains in the box  2 , the drive-away means  23  determines this to be an error and pushes out and drives away the box  2  to the drive-away line A. 
   Now, with reference to  FIGS. 5 to 10 , a description will be given of the configuration of a fluid injecting device  30  provided in the fluid injecting station  5 . In  FIG. 5 ,  31  is an elevating and lowering portion, and the elevating and lowering portion  31  can be elevated and lowered by, for example, a motor M. When the elevating and lowering portion  31  is thus elevated and lowered by the motor M, one end of a chain  32  or the like is attached to the elevating and lowering portion  31 . The other end of the chain  32  is wound around a driving sprocket S via a sprocket (not shown in the drawings) provided at the top of a fixed portion  33 . The driving sprocket S is rotatively driven by the motor M. The elevation and lowering of the elevating and lowering portion  31  is controlled by regulating power supplied to the motor M in accordance with the detected height position of the nozzle  8  on the basis of the detection executed by the nozzle height position detecting means  20 . Control means according to Claim  1  is composed of the motor M, the driving sprocket S, and the chain  32 . 
   A base portion  34  is provided with the elevating and lowering portion  31 . The base portion  34  is attached to a cylinder rod  35   a  of a cylinder  35  fixed to the elevating and lowering portion  31 . The cylinder rod  35   a  is placed so as to approach the conveying line  1  from a direction perpendicular to the conveying line  1  when expanded and to leave the conveying line  1  when contracted. The cylinder  35  is connected to an air supply/discharge switching portion (not shown in the drawings) through supply/discharge tubes  36 ,  37 . 
   Accordingly, the base portion  34  operates to approach or leave the conveying line  1  as the cylinder  35   a  is expanded or contracted. 
   A pivotal shaft  38  is provided upright from the base portion  34 . A movable frame  39  is rotatably attached to the pivotal shaft  38 . When the nozzle  8  is gripped, the movable frame  39  follows the nozzle  8 . A projection  40  is provided on a bottom surface of the movable frame  39 . Further, a projection  41  is provided on a top surface of the base portion  34 . The opposite ends of a spring  42  are attached to the respective projections  40 ,  41 . Thus, the force of the spring  42  prevents the movable frame  34  from moving rotatively around the pivotal shaft  38  except when the nozzle  8  is gripped. 
   As shown in  FIG. 5 , the air supply portion  19 , shown in  FIG. 1 , is provided on a top surface of the movable frame  39 . A spring  44  is provided between a rear end of the air supply portion  19  and a movable plate  43 . Further, a cylinder rod  45   a  of a cylinder  45  is attached to the movable plate  43 . Accordingly, when air is supplied to or discharged from the cylinder  45  to expand or contract the cylinder rod  45   a , the movable plate  43  and the air supply portion  19  slide. As the movable plate  43  slides, the air supply portion  19  approaches or leaves the nozzle  8 . 
   As shown in  FIG. 6 , a through-hole  47  is formed in the center of the air supply portion  19 , and a hole  19   a  is also formed in a side surface of the air supply portion  19 , and an air supply tube  48  is connected to the hole  19   a . The tip of the through-hole  47  constitutes an air supply port  49 , and the air supply port  49  can be connected to the nozzle  8  to supply air to the nozzle  8 . The air supply portion  19  releases air supplied through the air supply tube  48 , to the nozzle  8 . through the through-hole  47  in the air supply portion  19 . Further, a vent pipe  50  is slidably inserted into the through-hole  47  in the air supply portion  19 . A tube  51  is connected to the vent pipe  50 . 
   The vent pipe  50  is used to detect the air pressure at the tip of the air supply portion  19 . When the value of the air pressure at the tip of the air supply portion  19  becomes equal to or larger than a predetermined threshold, the supply of air to the air supply portion  19  is stopped. That is, when the air bag  7  is supplied with and becomes full of air or if the supply of air to the air bag  7  is inhibited, the supplied air flows backwards through the vent pipe  50 . Thus, when air flows through the vent pipe  50  and the backward flow pressure reaches the threshold, the supply of air to the air supply portion  19  is stopped. As a result, the supply of air to the nozzle  8  is stopped. In the present embodiment, in addition to the nozzle height position detecting means  20 , the vent pipe  50  is used to detect the air pressure. However, the detection can be achieved using only the nozzle height position detecting means  20 . 
   As shown in  FIG. 5 , the movable frame  39  is provided with a gripping device  52 .  FIG. 8  is a front view of the gripping device  52 . The gripping device  52  comprises gripping portions  53 ,  53  and a cylinder  54  that drives the gripping portions  53 ,  53 . The gripping portions  53 ,  53  are devices that grip the nozzle  8  by being closed or opened when air is supplied to or discharged from the cylinder  54 . A semicircular concave portion  55  is formed on each of the opposite surfaces of the gripping portions  53 ,  53 . When the gripping portions  53 ,  53  grip the nozzle  8 , the nozzle  8  can be appropriately gripped so that the two concave portions  55 ,  55  sandwich the nozzle  8  between them. 
   The gripping device  52  grips the nozzle  8  when a fluid is injected into the air bag  7  as shown in  FIG. 6 . Further, once the injection of the fluid into the air bag  7  is completed, the gripping device  52  leaves the air bag  7  while keeping gripping the nozzle  8  as shown in  FIG. 7 . 
   As shown in  FIGS. 1 and 8 , the gripping device  52  is provided with the nozzle presence detecting means  18 . The nozzle presence detecting means  18  is composed of a photoelectric switch, and so on. The nozzle presence detecting means  18  can detect whether or not the gripping device  52  has gripped the nozzle  8 . 
   Consequently, when the nozzle presence detecting means  18  does not detect the presence of the nozzle  8 , which would otherwise be gripped by the gripping portions  53  in order to inject the fluid into the air bag  7  as shown in  FIG. 6 , it is possible to detect that the nozzle  8  has not been attached to the box  2  conveyed from upstream. Further, a fluid has been completely injected into the air bag  7 , and when the nozzle presence detecting means  18  does not detect the presence of the nozzle  8 , which would otherwise be kept gripped by the gripping device  52  leaving the air bag  7  as shown in  FIG. 7 , it is possible to detect that the nozzle  8  remains attached to the box  2 , that is, the nozzle  8  remains in the box  2  instead of being removed. 
   In  FIG. 5 ,  56  is horizontal positioning means. The horizontal positioning means  56  holds a projecting end side of the nozzle  8 , which projects from the box  2 , horizontally so as to sandwich the projecting end side of the nozzle  8  between its upper and lower parts to position the nozzle  8  horizontally. The horizontal positioning means  56  is composed of a cylinder  57  extending in a vertical direction, a presser member  59  attached to a cylinder rod  58  of the cylinder  57 , and a receiving member  60  provided opposite the presser member  59  as shown in  FIGS. 9 and 10 . The receiving member  60  supports the nozzle  8  at one point from below. On the other hand, the presser member  59  presses the nozzle  8  at two points so as to stride the receiving member  60 . A tapered surface is formed on the presser member  59  to regulate the lateral position of the nozzle  8 . In the horizontal positioning means configured as described above, with its lateral movement regulated by tapered surfaces  61 ,  61 , the nozzle  8  is sandwiched between the presser member  59 , located above, and the receiving member  60 , located below, at three points. The nozzle  8  is thus appropriately positioned. In the above description, the receiving member  60  is provided below the nozzle  8 , while the presser member  59  is provided above the nozzle  8 . However, the receiving member  60  is provided above the nozzle  8 , while the presser member  59  may be provided below the nozzle  8 . 
   Now, the operation of the present invention will be described. As shown in  FIG. 1 , the empty packing box  2  is conveyed from upstream of the conveying line  1 . When the box  2  reaches the article loading station  3 , the desired article  6  is loaded into the box  2 . Further, the deflated air bag  7  is placed on the article  6 . Moreover, the nozzle  8  is installed on the air bag  7 . 
   Then, the box  2  is conveyed to the banding station  4 , located downstream. In the banding station  4 , as shown in  FIG. 3 , the cover  9  is placed on the box  2  to close it. Then, the outer periphery of the box  2  is tied with the band  10 . 
   Then, in the fluid injecting station  5 , as shown in  FIG. 5 , the nozzle height position detecting means  20  detects the top surface of the box  2 , that is, the height position of the nozzle  8 . The height position of the elevating and lowering portion  31  is adjusted on the basis of the detection executed by the height position detecting means  20  to align the height position of the air supply portion  19  with the height position of the nozzle  8 . 
   Subsequently, as shown in  FIG. 5 , the cylinder rod  35   a  of the cylinder  35  is extended to move the base portion  34  closer to the nozzle  8 . Air is supplied to or discharged from the cylinder  57  of the horizontal positioning means  56  to contract the cylinder rod  58 . The presser member  59  is thus lowered to press the nozzle  8  from above. In this case, as shown in  FIGS. 9 and 10 , the nozzle  8  is pressed at three points by the presser member  59  and the receiving member  60 , and is thus positioned horizontally. 
   Then, as shown in  FIG. 8 , the cylinder  54  is actuated to allow the gripping portions  53 ,  53  to grip the nozzle  8 . Then, as shown in  FIG. 6 , the cylinder rod  45   a  of the cylinder  45  is contracted to connect the air supply portion  19  to the nozzle  8 . 
   Then, the air supply portion  19  supplies air, which then flows through the nozzle  8  to inflate the air bag  7 . 
   Then, when the nozzle height position detecting means  20 , shown in  FIG. 1  or  FIG. 4 , detects that the top surface of the box  2  has been inflated, that is, that the air bag  8  is full of the fluid, the supply of air from the air supply portion  19  to the nozzle  8  is stopped. This in turn stops the injection of the fluid into the air bag  7 . 
   Then, in the state shown in  FIG. 6 , the cylinder rod  45   a  of the cylinder  45  is extended to separate the air supply portion  19  from the nozzle  8 . Subsequently, as shown in  FIG. 7 , the cylinder rod  58  of the cylinder  57  is extended upward to separate the presser member  59  of the horizontal positioning member  56  from the nozzle  8 . Then, as shown in  FIG. 7 , the cylinder rod  36  of the cylinder  35  is contracted. The base portion  34  is then separated from the box  2  with the gripping device  52  keeping gripping the nozzle  8 . That is, the nozzle  8  can be removed from the air bag  7 . In this state, the gripping device  52  is opened to drop the nozzle  8  into a recovery box. Thus, the process of injecting the fluid into the air bag  7  is completed. Nozzle removing means removes the nozzle  8  from the air bag  7  after the fluid has been injected into the air bag  7 . The nozzle removing means is composed of the cylinder  35 , the base portion  34 , the movable frame  39 , and the gripping device  52  as shown in  FIG. 7 . 
   On the other hand, if the nozzle  8  cannot be removed from the air bag  7  as shown in  FIG. 7 , the nozzle presence detecting means  18  of the gripping device  52  does not detect the presence of the nozzle  8 . In this case, the nozzle  8  remains in the air bag  7 . Consequently, the drive-away means  23 , shown in  FIG. 1 , drives the box  2  in which the nozzle  8  remains, away to the drive-away line A so as to push it out. 
   In the above description, as shown in  FIG. 4 , the nozzle height position detecting means  20  is composed of the light emitting portion  21 , located above the center of the box  2 , and the light receiving portion  22 . However, as shown in  FIG. 11 , plural sets of a light emitting portion  12  and a light receiving portion  13  may be arranged in a vertical direction so that the height position of the top surface of the box  2 , that is, the height position of the nozzle  8  can be detected by the light emitting portion  12  and the light receiving portion  13  corresponding to the position where the box  2  blocks the beam R. 
     FIGS. 12 and 13  show a variation of the presser member  59  of the horizontal positioning means  56 . A presser member  80  comprises an attachment portion  81  attached to the tip of the cylinder rod  58  as shown in  FIG. 6 , a presser piece  82  folded downward from the tip of the attachment portion  81 , and an auxiliary presser piece  83  provided inside the presser piece  82 . A presser groove  84  has a pair of tapered surfaces  85 ,  85  that fans out downward. Further, the auxiliary presser piece  83  has a horizontal auxiliary presser portion  86  extending straight in the horizontal direction. The auxiliary presser piece  83  is generally L-shaped. 
   In the presser member  59  formed as described above, as shown in  FIG. 12 , the tapered surfaces  85 ,  85  of the presser portion  81  guide the nozzle  8  to the bottom of the presser groove  84 . The horizontal auxiliary presser portion  86  of the auxiliary presser piece  83  positions the nozzle  8  horizontally so that the surfaces press the nozzle  8  downward.