Bag body opening method and bag body opening device

Abstract

To provide a bag opening method and a bag opening device capable of reliably opening a bag even if it is difficult to open a bag mouth.SOLUTION: A preparation step S02 and an opening step S03 are provided. The preparation step S02 includes a first adsorption step S21 for adsorbing a back surface of a bag body B placed on a placement table 10, a gripping step S22 for gripping both side edge parts B2 and B2 in the width direction (left and right direction) of the bag body B by a pair of gripping means 40 and 40, and a second adsorption step S23 in which adsorption means 50 is brought close to the surface of the bag body B and the surface is adsorbed by the adsorption means 50. The opening step S03 includes a first moving step S31 for moving the pair of gripping means 40 and 40 in directions close to each other, a second moving step S32 for moving the pair of gripping means 40 and 40 to the side opposite to the placement table 10 side with respect to the bag body B, and a third moving step S33 for moving the adsorption means 50 to the side opposite to the placement table 10 side with respect to the bag body B.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a method for opening a bag body and a bag body opening device.

Background Art

[0002] For example, a continuous packaging machine that continuously manufactures a bag body while pulling out a long plastic film wound in a roll shape, sequentially inserts articles into the manufactured bag body, and then seals the bag mouth of the bag body to package the articles, or a bag feeding packaging machine that accumulates a plurality of bag bodies in a storage shelf in advance, sequentially takes out the bag bodies from the storage shelf, sequentially inserts articles into the taken-out bag bodies, and then seals the bag mouth of the bag body to package the articles. Various packaging machines for packaging articles with a bag body have been conventionally known. In such a packaging machine, it is necessary to open the bag mouth of the bag body at a stage before inserting the article into the bag body. For example, a method of opening the bag mouth of the bag body by adsorbing the front and back surfaces of the bag body with a pair of adsorbing means respectively and then separating the pair of adsorbing means from each other while maintaining the adsorbed state, or a method of ejecting compressed air into the bag mouth of the bag body to open the bag mouth is known. For example, in Patent Document 1, for a bag (bag body) mainly suspended in a vertical posture, a method of opening the bag mouth by adsorbing the vicinity of the bag mouth on the front and back surfaces of the bag with a pair of suction cups (adsorbing means) and separating the pair of suction cups from each other, or a method of gripping the vicinity of the bag mouth at both side edges in the width direction of the bag with a pair of grippers (gripping means) and then bringing the pair of grippers closer to each other toward the central portion in the width direction to open the bag mouth, or a method of ejecting compressed air toward the bag mouth of the bag in accordance with various operations in these methods to assist the opening operation of the bag mouth is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, depending on the material, thickness, outer size, etc. of the bag body, there are some that are difficult to open the bag mouth. For example, in the case of a bag body in which the front and back surfaces are each formed of different materials with different hardnesses, since the behaviors of the front and back surfaces when the bag mouth opens are very different from each other, in the conventional method as described above, when separating a pair of suction cups (suction means) from each other, one of the suction cups is peeled off from the bag (bag body) (that is, the suction state is released), etc., and it is easy to cause an opening operation error of the bag mouth. As a result, it has an adverse effect on the article feeding step of inserting an article into the bag body, which is the next step, and can be a factor causing a decrease in the operating rate of the entire apparatus.

[0005] The present invention has been made in view of the above-described current problems, and an object thereof is to provide a bag body opening method and a bag body opening apparatus that can surely open even a bag body that is difficult to open the bag mouth.

Means for Solving the Problems

[0006] The problems to be solved by the present invention are as described above. Next, means for solving these problems will be described. That is, the bag body opening method according to the present invention is a bag body opening method for opening the bag mouth of a bag body formed in a rectangular long sheet shape and having a bag mouth at one end side in the longitudinal direction, comprising a preparation step of preparing for the opening operation of the bag mouth, and an opening step of performing the opening operation of the bag mouth after the completion of the preparation step. The preparation step includes a first suction step of sucking the back surface, which is the mounting table side, of the bag body placed on the mounting table in a horizontal posture with the bag mouth closed, a gripping step of gripping both side edges in the width direction orthogonal to the longitudinal direction of the bag body by a pair of gripping means, and a second suction step of bringing a suction means close to the surface on the side opposite to the back surface of the bag body and sucking the surface by the suction means. The opening step includes a first movement step of moving the pair of gripping means in a direction approaching each other, a second movement step of moving the pair of gripping means to the side opposite to the mounting table side with respect to the bag body, and a third movement step of moving the suction means to the side opposite to the mounting table side with respect to the bag body.

[0007] Further, the bag body opening device according to the present invention is a bag body opening device for opening the bag mouth of a bag body formed in a rectangular long sheet shape and having a bag mouth at one end side in the longitudinal direction, comprising a mounting table for mounting the bag body in a horizontal posture with the bag mouth closed and sucking the back surface, which is the mounting side of the bag body, a pair of gripping means for gripping both side edges in the width direction orthogonal to the longitudinal direction of the bag body, a suction means for sucking the surface on the side opposite to the back surface of the bag body, a suction means movement mechanism for making the suction means movable in a direction approaching and separating from the surface of the bag body, a first gripping means movement mechanism for making the pair of gripping means movable in a direction approaching and separating from each other, and a second gripping means movement mechanism for making the pair of gripping means movable with respect to the bag body in the mounting table side and the side opposite to the mounting table side.

Advantages of the Invention

[0008] As an effect of the present invention, the following effects are achieved. That is, according to the bag body opening method and the bag body opening device of the present invention, even a bag body with a difficult-to-open bag mouth can be surely opened.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Best Mode for Carrying Out the Invention

[0010] Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 8. For the following description, for convenience, the vertical direction, the front-rear direction, and the left-right direction of the bag body opening device 1 are defined and described according to the direction of the arrows shown in FIGS. 1 to 6. Also, the vertical direction, the front-rear direction, and the left-right direction of the bag mouth inspection device 101 are defined and described according to the direction of the arrows shown in FIG. 7. Furthermore, in FIG. 8, based on the state of being placed on the mounting table 10, the vertical direction, the front-rear direction, and the left-right direction of the bag body B are defined and described according to the direction of the arrow.

[0011] [Bag Body Opening Method] First, the bag body opening method embodied by the present embodiment will be described with reference to FIGS. 1 and 8. The bag body opening method in the present embodiment is a method of opening the bag mouth B1 (see FIG. 8) of the continuously supplied bag body B, and is implemented by the bag body opening device 1 (see FIG. 2) described later.

[0012] Here, as shown in FIG. 8(a), in the present embodiment, the bag body B targeted for the opening operation is formed in, for example, a rectangular long sheet shape, and has a bag mouth B1 at one end side in the longitudinal direction (for example, the front end side in the present embodiment). Specifically, the bag body B is composed of a configuration in which a first sheet member Ba and a second sheet member Bb (see FIG. 8(b)), each cut into a substantially rectangular long sheet shape, are superimposed, and are continuously heat-pressed across both side edge portions B2·B2 in the width direction (the left-right direction in the present embodiment) and the side edge portion B3 at the other end side in the longitudinal direction (for example, the rear end side in the present embodiment), thereby forming a bag shape.

[0013] And in FIG. 8(b), the first sheet member Ba that forms the front surface which is the upper surface of the bag body B is made of a soft plastic film with low hardness, and the second sheet member Bb that forms the back surface which is the lower surface of the bag body B is made of a firm non-woven fabric that is slightly harder than the plastic film.

[0014] Note that the materials of the first sheet member Ba and the second sheet member Bb are not limited to this embodiment. For example, when the bag body B is placed on the placement table 10 with the front surface of the bag body B facing downward and the back surface facing upward, the first sheet member Ba that forms the upper surface may be made of non-woven fabric, and the second sheet member Bb that forms the lower surface may be made of plastic film.

[0015] Thus, in the bag body B in which the front surface (i.e., the first sheet member Ba) and the back surface (i.e., the second sheet member Bb) are each formed of different materials with different hardnesses, when the bag opening B1 opens, the behaviors of the front surface and the back surface are greatly different from each other. Therefore, when performing the opening operation of the bag opening B1 of the bag body B placed in a horizontal posture, since the front surface (the first sheet member Ba) and the back surface (the second sheet member Bb) are affected by gravity, for example, the adsorption position of the adsorption pad performing the opening operation is likely to come off. In particular, when it is made of a firm sheet member, it is easily affected and opening operation errors are likely to occur.

[0016] Also, when the bag body B is placed in a horizontal posture, it is difficult to move the placement part (for example, the placement table 10 described later) that places the bag body B in the vertical direction while adsorbing the back surface of the bag body B. Therefore, the adsorption pad adsorbs the bag surface on the side opposite to the placement part with the adsorption pad, and then moves the adsorption pad in the separating direction to open the bag opening B1. However, if the placement part is fixed without moving and only the adsorption side of each piece is moved in this way, the bag body B itself is easily pulled in the moving direction, and the back surface (the second sheet member Bb) adsorbed by the placement part is likely to peel off. In particular, when the surface (back surface) of the placement portion that adsorbs is made of a rigid body (such as an adsorption pad that does not easily elastically deform) that is difficult to elastically deform, the adsorption portion is likely to peel off. Also, when opening the bag body B in which a seat member with a waist is arranged on the placement portion side, it becomes easier to peel off from the placement portion.

[0017] In the bag body opening device 1 in the present embodiment, as will be described later, while the bag body B is reliably held by adsorbing the back surface of the bag body B in a stable horizontal posture state placed on the placement table 10, when performing the opening operation of the bag mouth B1, only the adsorption means 50 (see FIG. 2) that adsorbs the surface of the bag body B is moved to the side opposite to the placement table 10 side (that is, the upper side). Thus, even for the bag body B in which the bag mouth B1 is difficult to open, it can be reliably opened.

[0018] As shown in FIG. 1, the bag body opening method in the present embodiment mainly includes a regulation step S01, a preparation step S02, an opening step S03, and an ejection step S04, etc., which are sequentially performed over time. However, in the following description, for each step (S21 to S23, and S31 to S33) in each of the steps S01 to S04, although described in the order of time, depending on the situation, each step may be performed simultaneously and is not particularly limited.

[0019] The regulation step S01 is a step of regulating the bag body B placed on the placement table 10 to a predetermined position. Here, the bag body B is supplied one by one to the bag body opening device 1, placed on the placement table 10 in a horizontal posture with the bag mouth B1 closed, and then regulated to a predetermined position on the placement table 10 by the regulation step S01.

[0020] The preparation step S02 is a step that is executed after the end of the regulation step S01 and is a step of preparing for the opening operation of the bag mouth B1. The preparation step S02 includes a first adsorption step S21, a gripping step S22, and a second adsorption step S23, which are sequentially performed over time.

[0021] The first suction step S21 is a step of sucking the back surface on the mounting table 10 side (more specifically, the vicinity of the bag mouth B1 on the back surface of the second sheet member Bb (see FIG. 8)) of the bag body B placed on the mounting table 10 in a horizontal posture with the bag mouth B1 closed, through the bottomed hole portion 11a (see FIG. 2(a)) of the first fixed mounting portion 11 described later.

[0022] Also, the gripping step S22 is a step of gripping both side edge portions B2·B2 (see FIG. 8) in the width direction (left - right direction) orthogonal to the longitudinal direction (front - rear direction) of the bag body B by a pair of gripping means 40·40 (see FIG. 3) described later.

[0023] Furthermore, the second suction step S23 is a step of bringing the suction means 50 (see FIG. 2(b)) described later close to the surface of the bag body B on the side opposite to the back surface (more specifically, the vicinity of the bag mouth B1 on the surface of the first sheet member Ba (see FIG. 8)), and sucking the surface of the bag body B by the suction means 50.

[0024] And when these first suction step S21, gripping step S22, and second suction step S23 are executed and the preparation step S02 is completed, subsequently, the opening step S03 is executed.

[0025] The opening step S03 is a step of starting the opening operation of the bag mouth B1 for the bag body B. The opening step S03 includes a first movement step S31 and a second movement step S32 that are executed simultaneously with each other, and a third movement step S33 that is executed after the completion of both these steps S31·S32.

[0026] The first movement step S31 is a step of moving a pair of gripping means 40·40 that grip both side edge portions B2·B2 of the bag body B by the above - mentioned gripping step S22 in a direction approaching each other.

[0027] Further, the second moving step S32 is also a step of moving a pair of gripping means 40·40 that grip both side edges B2·B2 of the bag body B to the side opposite to the mounting table 10 side with respect to the bag body B, that is, the upper side.

[0028] Furthermore, the third moving step S33 is a step of moving the suction means 50 that has suctioned the vicinity of the bag mouth B1 on the surface of the bag body B by the second suction step S23 to the side opposite to the mounting table 10 side with respect to the bag body B, that is, the upper side.

[0029] Then, as will be described later, by simultaneously executing the first moving step S31 and the second moving step S32, first, the back surface (second sheet member Bb) is curved downward together with the surface (first sheet member Ba) of the bag body B, and subsequently, by executing the third moving step S33, only the surface (first sheet member Ba) of the bag body B is curved upward, and the bag mouth B1 of the bag body B is opened. Note that when the opening step S03 is completed, the ejection step S04 is subsequently executed.

[0030] By the way, the timing of executing the first moving step S31 and the second moving step S32 is not limited to being simultaneous as in this embodiment. For example, after executing the first moving step S31 (or the second moving step S32), the second moving step S32 (or the first moving step S31) may be executed. Also, regarding the timing of executing the third moving step S33, although it is set to be executed after executing the first moving step S31 and the second moving step S32, the first moving step S31, the second moving step S32, and the third moving step S33 may be executed simultaneously.

[0031] However, as will be described later, by simultaneously performing the first movement step S31 and the second movement step S32, as the back surface (second sheet member Bb) of the bag body B is gradually curved so as to protrude downward, it becomes possible to appropriately move the mounting table 10 relatively away from the bag body B, and it is possible to prevent the adsorption state on the back surface of the bag body B from being peeled off (released), which is more preferable.

[0032] The ejection step S04 is a step of ejecting compressed air toward the inside of the bag body B through the bag mouth B1 to assist the opening operation of the bag mouth B1. Here, in the present embodiment, the ejection step S04 is executed after the completion of the opening step S03, but it is not limited thereto, and it may be executed at any timing as long as it is after the completion of the preparation step S02.

[0033] Each of the steps (restriction step S01, preparation step S02, opening step S03, and ejection step S04) constituting the bag body opening method shown above is realized by each operation sequentially executed by the bag body opening device 1 over time.

[0034] [Bag body opening device 1] Next, the overall configuration of the bag body opening device 1 will be described with reference to FIGS. 2, 3, 7, and 8. The bag body opening device 1 in the present embodiment is a device provided in a packaging machine that sequentially inserts articles W (see FIG. 7(b)) into the continuously supplied bag body B and then seals the bag mouth B1 of the bag body B to package the articles W, and is a device that opens the bag mouth B1 of the bag body B before inserting the articles W. As shown in FIG. 2(a), the bag body opening device 1 mainly includes a mounting table 10, a positioning device 20, a fixed guide 30, a gripping means 40, a suction means 50 (see FIG. 2(b)), a suction means moving mechanism 60 (see FIG. 2(b)), a first gripping means moving mechanism 70, a second gripping means moving mechanism 80 (see FIG. 3), and an ejection means 90, etc.

[0035] The mounting table 10 mounts and holds the bag body B in a horizontal posture at a predetermined position of the bag body opening device 1. The placing table 10 includes, for example, a rectangular parallelepiped-shaped first fixed placing portion 11, a reverse "L"-shaped second fixed placing portion 12 that extends rearward from the rear side surface of the first fixed placing portion 11, and a rectangular parallelepiped-shaped moving placing portion 13 that is spaced apart from the second fixed placing portion 12 on the rear side and is provided so as to be movable in the front-rear direction. The upper surfaces of the first fixed placing portion 11, the second fixed placing portion 12, and the moving placing portion 13 are each set to be located on a common virtual horizontal plane L (see Fig. 2(b)), and constitute the placing surface of the bag body B.

[0036] Note that the shapes of the first fixed placing portion 11, the second fixed placing portion 12, and the moving placing portion 13 are not limited to those in this embodiment, and any shape may be used as long as it has an upper surface located on the common virtual horizontal plane L. Also, the split structure composed of the first fixed placing portion 11 and the second fixed placing portion 12 is not limited to this embodiment, and an integral structure made of a common material may be used.

[0037] Furthermore, the moving placing portion 13 is provided so as to be movable in the front-rear direction in order to correspond to various types of bag bodies B having different outer dimensions (dimensions in the longitudinal direction). At least when the dimension in the longitudinal direction of the bag body B that is the object of the opening operation by the bag body opening device 1 is defined as one type, it is not necessary to provide the moving function of the moving placing portion 13.

[0038] On the upper surface of the first fixed placing portion 11, an oval-shaped bottomed hole portion 11a that extends in the left-right direction in a plan view is provided on the front side of the central portion in the left-right direction. As shown in Fig. 2(b), the bottom surface of the bottomed hole portion 11a communicates with the outside of the first fixed placing portion 11 through a through passage 11b, and a first vacuum pump 2 is connected to the through passage portion 11b via a piping member, a solenoid valve, etc. (not shown).

[0039] After the bag body B is placed on the placing table 10 in a horizontally oriented state at a predetermined position, when the first vacuum pump 2 operates, the inside of the bottomed hole portion 11a becomes a vacuum state, and the bag body B placed on the placing table 10 is adsorbed on the back surface on the side of the placing table 10. In this embodiment, the inside of the bottomed hole 11a is evacuated using the first vacuum pump 2 to adsorb the back surface of the bag body B. However, the present invention is not limited to this. For example, a commercially available negative pressure generating means utilizing the ejector effect may be used to adsorb the back surface of the bag body B.

[0040] Further, a rear guide member 14 that extends upward beyond the upper surface of the moving placement portion 13 is fixed to the rear side surface of the moving placement portion 13. The rear guide member 14 moves in the front-rear direction following the movement of the moving placement portion 13 and abuts against the rear end portion of the bag body B placed on the placement table 10, and is configured to be able to regulate the position of the bag body B in the longitudinal direction (front-rear direction).

[0041] The positioning device 20, together with the above-described rear guide member 14, regulates the position of the bag body B placed on the placement table 10 in the longitudinal direction (front-rear direction) to a predetermined position. The positioning device 20 includes, for example, a pair of regulating bars 21·21 that extend in the vertical direction and have contact surfaces 21a·21a at the upper end portions of the rear side surfaces, and a rotating shaft 22 that extends in the left-right direction and penetrates through the lower end portions of the pair of regulating bars 21·21. As shown in FIG. 2(a), the pair of regulating bars 21·21 are respectively arranged in front of the placement table 10 (more specifically, the first fixed placement portion 11) and spaced apart from both sides in the left-right direction, and the contact surfaces 21a·21a are provided so as to be able to approach the upper end portion of the front side surface of the first fixed placement portion 11.

[0042] Then, as shown in FIG. 2(b), when the rotating shaft 22 is rotated about its axis by a drive motor (not shown), the pair of regulating bars 21·21 are displaced between a regulating position where the contact surfaces 21a·21a approach the first fixed placement portion 11 (the position of the regulating bar 21X shown by the solid line in FIG. 2(b)) and a retracted position where the contact surfaces 21a·21a are separated from the first fixed placement portion 11 (the position of the regulating bar 21Y shown by the two-dot chain line in FIG. 2(b)).

[0043] With the positioning device 20 configured as described above, the front end portion of the bag body B is restricted, and the rear end portion of the bag body B is restricted by the rear guide member 14 provided on the moving placement portion 13. As a result, the position of the bag body B placed on the placement table 10 in the front-rear direction is restricted to a predetermined position. Specifically, after the bag body B is placed on the placement table 10 in a horizontal posture, the pair of restricting bars 21, 21 are displaced from the retracted position to the restricting position. Thereby, the bag body B on the placement table 10 is pushed rearward through the front end portion by the contact surface 21a of the restricting bar 21. Thereafter, when the rear end portion of the bag body B comes into contact with the rear guide member 14, the position of the bag body B in the longitudinal direction (front-rear direction) is restricted to a predetermined position.

[0044] The fixed guide 30 restricts the position of the bag body B placed on the placement table 10 in the width direction (left-right direction) to a predetermined position. The fixed guide 30 is provided on both the left and right sides of the placement table 10 (see Fig. 2(a)), includes a pair of side guide members 31, 31 that extend in the front-rear direction along the placement table 10 and extend upward beyond the upper surface of the placement table 10, and support members 32, 32 that support the pair of side guide members 31, 31.

[0045] Then, as will be described later, when the bag body B is supplied to the bag opening device 1 by a transfer machine (not shown), the bag body B is placed on the placement table 10 from above while passing between the pair of side guide members 31, 31 in a horizontal posture. At this time, at least one end of the bag body B in the width direction (left-right direction) comes into contact with one of the pair of side guide members 31, 31, and the position of the bag body B in the width direction (left-right direction) is restricted to a predetermined position.

[0046] The gripping means 40, together with the suction means 50 described later, performs an opening operation on the bag mouth B1 (see Fig. 8) of the bag body B placed on the placement table 10 in a horizontal posture. The gripping means 40 is constituted by, for example, a commercially available air chuck or the like having a pair of chuck jaws 41·41 rotatable in the vertical direction, and as shown in Fig. 2(a), is disposed on both sides in the left-right direction of the mounting table 10 (more specifically, the first fixed mounting portion 11).

[0047] Specifically, as shown in Fig. 3, these pair of gripping means 40·40 are disposed facing each other in the left-right direction with the upper surface of the first fixed mounting portion 11 interposed therebetween, with the chuck jaw portions 41·41 each directed toward the first fixed mounting portion 11 side. Further, each gripping means 40 is provided such that the pair of chuck jaws 41·41 can be displaced between an open state in which they are rotated in a direction away from each other and a closed state in which they are rotated in a direction approaching each other.

[0048] And these pair of gripping means 40·40 are configured to be able to grip both side edges B2·B2 (see Fig. 8) in the width direction (left-right direction) orthogonal to the longitudinal direction (front-rear direction) of the bag body B placed on the mounting table 10 in a horizontal posture, in the vicinity of the bag mouth B1 (i.e., the front end portion of the bag body B). After gripping the bag body B, the pair of gripping means 40·40 are moved in a predetermined direction by the first gripping means moving mechanism 70 and the second gripping means moving mechanism 80 described later, whereby the opening operation of the bag mouth B1 in the bag body B is performed.

[0049] The suction means 50, together with the above-described gripping means 40, performs the opening operation of the bag mouth B1 on the bag body B placed on the mounting table 10 in a horizontal posture. The suction means 50·50 is constituted by, for example, commercially available suction pads or the like, and a plurality (two in this embodiment) are provided and are each disposed in a state of being separated from each other in the left-right direction above the mounting table 10 and at the center portion in the left-right direction with the suction surface facing downward. Also, as shown in Fig. 2(b), in a side view, these pair of suction means 50·50 are each disposed at a position substantially directly above the bottomed hole portion 11a provided in the first fixed mounting portion 11.

[0050] The suction means 50 is connected to a transfer machine (not shown later), and is set so that the suction means 50 is positioned at a suction standby position P12 (described later) simultaneously with the operation of the transfer machine transferring the bag body B to the mounting table 10. Therefore, compared with the case of providing the suction means separately and independently from the above transfer machine, the cycle time can be shortened. Note that the configuration in which the suction means 50 is connected to the transfer machine is not particularly limited, and may be appropriately determined according to the configuration of the transfer means of the bag body B or the like.

[0051] Note that the number of the suction means 50 is not limited to the present embodiment, and may be one or three or more.

[0052] These pair of suction means 50·50 are both connected to the second vacuum pump 3 via piping members, solenoid valves, etc. (not shown). Here, for the second vacuum pump 3, the first vacuum pump 2 connected to the bottomed hole portion 11a of the first fixed mounting portion 11 described above may be shared and used, or may be separately provided separately from the first vacuum pump 2. However, when the first vacuum pump 2 is shared and used, for example, since the timing of the suction operation by the bottomed hole portion 11a and the timing of the suction operation by the suction means 50 are different, it is necessary to provide separate control circuits for each. Note that the second vacuum pump 3 is not limited to this, and for example, a commercially available negative pressure generating means utilizing the ejector effect may be used to suck the surface of the bag body B.

[0053] As will be described later, the suction means 50 is configured to be movable (lift) in the vertical direction by a suction means moving mechanism 60. By moving (lowering) downward by the suction means moving mechanism 60, it approaches the bag body B placed on the mounting table 10 in a horizontal posture, and is configured to contact the vicinity of both left and right end portions of the bottomed hole portion 11a in a plan view on the surface opposite to the back surface of the bag body B. Then, in a state where the back surface of the bag body B is adsorbed by the bottomed hole portion 11a, after the adsorption means 50 abuts on the front surface of the bag body B, when the second vacuum pump 3 operates, the adsorption means 50 adsorbs the front surface of the bag body B, and then further, by moving (rising) upward by the adsorption means moving mechanism 60, the bag mouth B1 of the bag body B is opened.

[0054] By abutting on a location near the bottomed hole portion 11a of the mounting table 10, the adsorption means 50 physically presses the bag body B against the bottomed hole portion 11a, and by eliminating the gap between the bag body B and the bottomed hole portion 11a, the adsorption state can be made more reliable. Particularly, in the case of the bag body B with a gusset, if it is only placed in a horizontal posture, due to the habit of the bag body B or the like, a gap is likely to be generated between the bag body B and the bottomed hole portion 11a, which may cause poor adsorption, so it is more effective.

[0055] Incidentally, the adsorption means 50 is set to adsorb the bag body B within the range of the adsorption region Sa (see FIG. 8) located at the center in the width direction (left - right direction) on the front surface of the bag body B on the bag - mouth B1 side, that is, on the front - end side (front - end side in the longitudinal direction). Specifically, as shown in FIG. 8(a), the contact portions 50a·50a where the pair of adsorption means 50·50 contact the front surface of the bag body B are set to be located within the range of the adsorption region Sa with respect to the width direction (left - right direction) of the bag body B.

[0056] And the dimension in the width direction (left - right direction) of the bag body B in the adsorption region Sa is set to 20% of the total length S in the width direction (left - right direction) of the bag body B.

[0057] Therefore, in the bag - opening device 1 in the present embodiment, for example, when the adsorption means 50 adsorbs outside the central portion in the width direction (left - right direction) of the bag body B, when the adsorption means 50 moves upward while remaining adsorbed, the closer to both ends of the bag body B, the more difficult it is for the adsorption means 50 to follow the upward movement, so the adsorption location is likely to be peeled off, and the opening operation error is likely to occur. Thus, it is configured to prevent this as much as possible.

[0058] The suction means moving mechanism 60 is configured to move the suction means 50 in directions approaching and separating from the surface of the bag body B placed on the mounting table 10 in a horizontal posture. As shown in FIG. 3, the suction means moving mechanism 60 is constituted by, for example, a commercially available electric or pneumatic actuator or the like, and is arranged such that the moving direction of the first movable part 61 is in the vertical direction, and the pair of suction means 50·50 are both supported via the first movable part 61.

[0059] When the suction means moving mechanism 60 operates and the first movable part 61 moves downward (descends), the pair of suction means 50·50 descend together with the first movable part 61 and are moved to the suction position P11 (the vertical position of the suction means 50 in FIG. 5(c)) approaching the bag body B on the mounting table 10. When the first movable part 61 moves upward (ascends), the pair of suction means 50·50 ascend together with the first movable part 61 and are moved to a predetermined suction standby position P12 (the vertical position of the suction means 50 in FIG. 5(a)) separated upward from the bag body B on the mounting table 10.

[0060] The first gripping means moving mechanism 70 is provided on each of the pair of gripping means 40·40 and is configured to move the pair of gripping means 40·40 in directions approaching and separating from each other. Each first gripping means moving mechanism 70 is constituted by, for example, a commercially available pneumatic actuator or the like, and is arranged such that the moving direction of the second movable part 71 is in the left-right direction and in directions approaching and separating from the mounting table 10 (more specifically, the first fixed mounting part 11), and each gripping means 40 is supported via the second movable part 71.

[0061] When the pair of first gripping means moving mechanisms 70·70 operate simultaneously and the second movable parts 71·71 both move in a direction approaching the mounting table 10, the pair of gripping means 40·40 are moved to the first opening position P21 (the left-right position of the pair of gripping means 40·40 in FIG. 6(a)) approaching each other. Further, when both the second movable parts 71·71 move in a direction away from the mounting table 10, the pair of gripping means 40·40 are moved to a predetermined first opening standby position P22 where they are separated from each other (the left and right positions of the pair of gripping means 40·40 in Fig. 5(a)).

[0062] The second gripping means moving mechanism 80 is provided on each of the pair of gripping means 40·40, and enables these pair of gripping means 40·40 to be movable toward the mounting table 10 side (i.e., the lower side) and the side opposite to the mounting table 10 side (i.e., the upper side) with respect to the bag body B placed on the mounting table 10 in a horizontal posture. Each second gripping means moving mechanism 80 is constituted by, for example, a commercially available pneumatic actuator or the like, and is arranged such that the moving direction of the third movable part 81 is in the vertical direction, and supports each gripping means 40 together with the above-described first gripping means moving mechanism 70 via the third movable part 81.

[0063] Then, when the pair of second gripping means moving mechanisms 80·80 operate simultaneously and the third movable parts 81·81 both move upward (rise), the pair of gripping means 40·40, together with the first gripping means moving mechanisms 70·70, are moved to a predetermined second opening position P31 located on the side opposite to the mounting table 10 side (i.e., the upper side) with respect to the bag body B (the vertical positions of the pair of gripping means 40·40 in Fig. 6(a)). Further, when the third movable parts 81·81 both move downward (fall), the pair of gripping means 40·40, together with the first gripping means moving mechanisms 70·70, are moved to a predetermined second opening standby position P32 located on the mounting table 10 side (i.e., the lower side) with respect to the bag body B (the vertical positions of the pair of gripping means 40·40 in Fig. 5(a)).

[0064] The ejection means 90 ejects compressed air toward the inside of the bag body B through the bag mouth B1 (see Fig. 8) with respect to the bag body B placed on the mounting table 10 in a horizontal posture. The ejection means 90 is constituted by, for example, a commercially available air nozzle or the like, and as shown in FIGS. 2(a) and 2(b), it is disposed in front of the mounting table 10 (more specifically, the first fixed mounting portion 11) and at the center in the left-right direction, with the ejection port facing the upper surface of the first fixed mounting portion 11. Further, the ejection means 90 is connected to the compressor 4 via a piping member, a solenoid valve or the like (not shown).

[0065] Then, when the opening operation of the bag mouth B1 in the bag body B by the gripping means 40 and the suction means 50 described above starts, compressed air is supplied from the compressor 4, and the compressed air is ejected from the ejection means 90 toward the inside of the bag body B.

[0066] [Operation of the bag opening device 1] Next, the operation of the bag opening device 1 will be described with reference to FIGS. 2, 4 to 6. First, in FIG. 2(b), both the first vacuum pump 2 and the second vacuum pump 3 are in an operating state, but the suction operation through the bottomed hole portion 11a of the mounting table 10 (more specifically, the first fixed mounting portion 11) and the suction operation through the suction means 50 are both stopped by a solenoid valve or the like (not shown). Similarly, the compressor 4 is also in an operating state, but the ejection operation of the compressed air from the ejection means 90 is stopped by a solenoid valve or the like (not shown).

[0067] And the positioning device 20 is in a state where both of the pair of regulating bars 21·21 are stopped at the retracted position. Also, as shown in FIG. 3, the pair of gripping means 40·40 are each stopped in the open state at the first opening standby position P22 and the second opening standby position P32. Furthermore, the pair of suction means 50·50 are stopped at the suction standby position P12.

[0068] In the bag body opening device 1 in such an initial state, one bag body B is supplied by a transfer device (not shown), and as shown in Fig. 4(a), the bag body B is placed on the mounting table 10 in a horizontal posture. At this time, the bag body B is placed on the mounting table 10 from above while bringing at least one end in the width direction (left - right direction) into contact with the side guide member 31. As a result, the position of the bag body B in the width direction (left - right direction) on the mounting table 10 is regulated to a predetermined position.

[0069] When the bag body B is placed on the mounting table 10, the regulation process S01 is executed. Specifically, as shown in Fig. 4(b), in the positioning device 20, a pair of regulating bars 21·21 immediately displace from the standby position to the regulation position. As a result, the bag body B is pushed backward by the pair of regulating bars 21·21 through one end (front end) in the longitudinal direction (front - rear direction), and then comes into contact with the rear guide member 14 through the other end (rear end) in the longitudinal direction (front - rear direction). Thus, the position of the bag body B in the longitudinal direction (front - rear direction) on the mounting table 10 is regulated to a predetermined position.

[0070] When the regulation process S01 ends, subsequently, the preparation process S02 is executed. Specifically, as shown in Fig. 5(a), a solenoid valve (not shown) provided between the first vacuum pump 2 and the bottomed hole portion 11a of the mounting table 10 is switched, and the suction operation by the bottomed hole portion 11a is started (first suction step S21). As a result, the back surface of the bag body B is adsorbed to the mounting table 10 through the bottomed hole portion 11a, and the position of the bag body B on the mounting table 10 is held.

[0071] When the suction operation by the bottomed hole portion 11a starts, as shown in Fig. 5(b), a pair of gripping means 40·40 both displace from the open state to the closed state (gripping step S22). As a result, the bag body B is held in a state where both side edge portions B2·B2 (see Fig. 8) in the width direction (left - right direction) are gripped by the pair of gripping means 40·40.

[0072] Furthermore, when both of the pair of gripping means 40·40 are displaced to the above closed state, as shown in FIG. 5(c), the suction means moving mechanism 60 operates, and the pair of suction means 50·50 are moved from the suction standby position P12 to the suction position P11. Also, when the pair of suction means 50·50 reach the suction position P11 and come into contact with the surface of the bag body B, a solenoid valve (not shown) provided between the second vacuum pump 3 and the pair of suction means 50·50 is switched, and the suction operation by the pair of suction means 50·50 is started (second suction step S23). As a result, one end (front end) in the longitudinal direction (front-rear direction) of the bag body B is pressed against the mounting table 10 by the pair of suction means 50·50, and the surface of the bag body B is adsorbed by the pair of suction means 50·50, and the preparation step S02 ends.

[0073] When the preparation step S02 ends, subsequently, the opening step S03 is executed. Specifically, as shown in FIG. 6(a), the pair of first gripping means moving mechanisms 70·70 and the pair of second gripping means moving mechanisms 80·80 operate simultaneously, and the pair of gripping means 40·40 are moved from the first opening standby position P22 to the first opening position P21 (first movement step S31), and are moved from the second opening standby position P32 to the second opening position P31 (second movement step S32). As a result, with one end (front end) in the longitudinal direction (front-rear direction) of the bag body B pressed against the mounting table 10 by the pair of suction means 50·50, both ends in the width direction (left-right direction) approach each other while rising, and the first sheet member Ba forming the surface and the second sheet member Bb constituting the back surface (see FIG. 8) both become curved downward.

[0074] Also, when both of the pair of gripping means 40·40 are moved to the first opening position P21 and the second opening position P31, as shown in FIG. 6(b), the suction means moving mechanism 60 operates, and the pair of suction means 50·50 are moved (raised) from the suction position P11 to a predetermined position on the upper side (third movement step S33). Note that the above-mentioned "predetermined position on the upper side" may be set to a position equivalent to the adsorption standby position P12, or may be set to any position between the adsorption position P11 and the adsorption standby position P12. As a result, the bag body B is in a state where the back surface is adsorbed through the bottomed hole portion 11a of the mounting table 10, and the first sheet member Ba forming the front surface is pulled upward and curved by the pair of adsorption means 50·50, and the bag mouth B1 of the bag body B is opened. Then, when the bag mouth B1 of the bag body B is opened by the pair of adsorption means 50·50, the opening step S03 ends.

[0075] When the opening step S03 ends, the ejection step S04 is subsequently executed. Specifically, as shown in FIG. 6(c), a solenoid valve (not shown) provided between the compressor 4 and the ejection means 90 is switched, and the ejection operation of compressed air from the ejection means 90 is started. As a result, the compressed air ejected from the ejection means 90 is blown into the bag body B through the bag mouth B1, the opening operation of the bag mouth B1 is assisted, and the bag body B is more surely opened at the bag mouth B1. Then, when a predetermined time has elapsed since the start of the ejection operation, the solenoid valve is switched again, and the ejection operation of compressed air from the ejection means 90 stops. As a result, the ejection step S04 ends, and the opening operation of the bag mouth B1 in the bag body B is completed.

[0076] When the ejection step S04 ends, the article W (see FIG. 7(b)) moves from the front of the bag mouth B1 together with a regulation guide (not shown) that regulates the width direction (left-right direction) of the article W to the bag body B with the bag mouth B1 opened, and is inserted through the opened bag mouth B1. After that, when the regulation guide retreats from the bag mouth B1, the filling of the article W is completed, and the bag body B is sent to the next step. However, the filling of the article W may be performed in the next step and is not particularly limited. Then, the bag body B has its bag mouth B1 sealed by means such as thermocompression bonding, and the sealing state of the bag mouth B1 is inspected by a bag mouth inspection device 101 described later.

[0077] On the other hand, when the bag body B is carried out from the bag body opening device 1, the bag body opening device 1 returns to the initial state described above again, and waits for one bag body B to be supplied by a transfer device (not shown).

[0078] [Bag mouth inspection device 101 for bag body B] Next, with respect to the bag mouth inspection device 101 that inspects the sealing state of the bag mouth B1 of the bag body B into which a predetermined article W is inserted and the bag mouth B1 is sealed, it will be described with reference to FIG. 7.

[0079] As described above, the bag body B with its bag mouth B1 opened by the bag body opening device 1 (refer to FIG. 2) is then inserted with a predetermined article W, the bag mouth B1 is sealed by means such as thermocompression bonding, and then the sealing state of the bag mouth B1 is inspected by a bag mouth inspection device 101 described later. Here, the inspection of the sealing state of the bag mouth B1 is generally carried out by an inspection device including illumination means arranged on the back side (or front side) of the bag body B, imaging means arranged on the front side (or back side), and control means for determining the presence or absence of positional deviation, wrinkles, fuzz, etc. in the sealing state of the bag mouth B1 and melting of the bag mouth B1 due to thermocompression bonding based on the image data acquired by the imaging means.

[0080] However, in the inspection method of the sealing state of the bag mouth B1 using such a general inspection device, when the sheet members forming the front and back surfaces of the bag body B are both made of a transparent material such as a plastic film, the above sealing state can be grasped substantially appropriately. However, as in the present embodiment, when at least one of the sheet members forming the front and back surfaces of the bag body B is made of an opaque non-woven fabric as a material, the transmission of light by the illumination means is hindered, it is difficult to acquire clear image data by the imaging means, and it is difficult to appropriately grasp the above sealing state. In addition, when the sheet member is a non-woven fabric, there is also a problem that it is difficult to distinguish foreign matters, lint, etc. due to the fibers on the surface.

[0081] For these reasons, in the present embodiment, by using the bag mouth inspection device 101 shown below, even for a bag body B having a sheet member made of an opaque non-woven fabric as a material, it is possible to substantially appropriately grasp the sealing state of the bag mouth B1 in the bag body B.

[0082] The bag mouth inspection device 101 in the present embodiment is a device provided in a packaging machine that sequentially inserts an article W into a continuously supplied bag body B and then seals the bag mouth B1 of the bag body B to package the article W, similar to the above-described bag body opening device 1. It is a device that inspects the sealing state of the bag mouth B1 with respect to the bag body B into which a predetermined article W is inserted and the bag mouth B1 is sealed.

[0083] As shown in FIGS. 7(a) and 7(b), the bag mouth inspection device 101 mainly includes a mounting table 110 for mounting the bag body B in a horizontal posture, an imaging means 120 disposed directly above one end (the front end in the present embodiment) of the mounting table 110, and a pair of first lighting means 130·130 that are disposed opposite to each other with the upper surface of one end (the front end) of the mounting table 110 interposed therebetween and illuminate the upper surface of the one end (the front end). Above the mounting table 110, on one side (the front side in the present embodiment) and the other side (the rear side in the present embodiment) in a direction orthogonal to the opposing direction of the pair of first lighting means 130·130 with respect to the imaging means 120, a pair of second lighting means 140·140 that illuminate the upper surface of one end (the front end) of the mounting table 110, and a control unit 150 that determines the sealing state of the bag mouth B1 in the bag body B based on the image data acquired by the imaging means 120, etc. In addition, the bag mouth inspection device 101 includes a transparent pressing bar 160 made of, for example, an acrylic plate or a glass plate in order to reliably hold the bag mouth B1 of the bag body B mounted on the mounting table 110.

[0084] The imaging means 120 can be constituted by, for example, a commercially available digital high-definition camera or the like, and any of a CCD image sensor, a CMOS image sensor, etc. may be provided as the imaging element. Also, the first illumination means 130 and the second illumination means 140 can be constituted by, for example, commercially available LED illumination or the like.

[0085] As the control unit 150, an interface connected to the imaging means 120, a storage device such as a ROM, RAM, HDD, etc., a CPU (arithmetic unit), and a display device are provided, and a general-purpose personal computer installed with a predetermined image processing program can be used.

[0086] Then, with the bag mouth inspection device 101 having such a configuration, a predetermined article W is inserted, and for the bag body B with the bag mouth B1 sealed, the sealing state of the bag mouth B1 is inspected according to the following procedure.

[0087] That is, first, the bag body B is carried into the bag mouth inspection device 101, and the bag body B is placed on the mounting table 110 in a horizontal posture with the longitudinal direction as the front-rear direction and the bag mouth B1 positioned directly below the imaging means 120, and the position of the bag mouth B1 is held by the pressing bar 160 (inspection preparation step S101). At this time, the bag body B is placed on the mounting table 110 with the plastic film forming the front surface (first sheet member Ba) facing upward and the non-woven fabric forming the back surface (second sheet member Bb) facing downward.

[0088] When the above inspection preparation step S101 is completed and the bag body B is placed on the mounting table 110, the pair of first illumination means 130·130 is lit for a predetermined time (approximately one-thousandth to one-ten-thousandth of a second), and illuminates the periphery of the bag mouth B1 from the horizontal direction (in this embodiment, the left-right direction). Also, simultaneously with the pair of first illumination means 130·130 being lit, the imaging means 120 images the front end portion of the bag body B including the bag mouth B1. Then, the first image data captured by the imaging means 120 is converted into an electrical signal and transmitted to the control unit 150. Based on the received first image data, the control unit 150 determines the positional deviation of the sealed state of the bag mouth B1, the presence or absence of wrinkles, etc. (first inspection determination step S102).

[0089] When the above first inspection determination step S102 is completed, subsequently, the pair of second illumination means 140·140 is lit for a predetermined time (approximately one thousandth to one ten-thousandth of a second), and illuminates the periphery of the bag mouth B1 from an obliquely upper direction (in this embodiment, obliquely front upper and obliquely rear upper). Also, simultaneously with the lighting of the pair of second illumination means 140·140, the imaging means 120 captures the front end portion of the bag body B including the bag mouth B1. Then, the second image data captured by the imaging means 120 is converted into an electrical signal and transmitted to the control unit 150. Based on the received second image data, the control unit 150 determines the presence or absence of fluff, etc. at the bag mouth B1 (second inspection determination step S103).

[0090] When the above second inspection determination step S103 is completed, the pressing bar 160 is separated from the bag body B and the holding state is released, and the bag body B is carried out from the bag mouth inspection device 101 (carrying out step S104). Thereby, the inspection of the sealed state of the bag mouth B1 by the bag mouth inspection device 101 is completed.

[0091] Thus, in the bag mouth inspection device 101 in this embodiment, the pair of first illumination means 130·130 and the pair of second illumination means 140·140, both of which are located above the mounting table 110, illuminate the bag mouth B1 of the bag body B, and based on the image data acquired by the imaging means 120, the inspection of the sealed state of the bag mouth B1 is carried out.

[0092] Therefore, different from the general inspection device as described above, even for the bag body B used in this embodiment in which at least one of the front and back surfaces is formed of an opaque non-woven fabric as a sheet member, the sealed state of the bag mouth B1 can be grasped substantially appropriately.

[0093] [Effect] As described above, the bag body opening method in the present embodiment is a bag body opening method for opening the bag mouth B1 of a bag body B formed in a rectangular long sheet shape and having the bag mouth B1 at one end side (front end side) in the longitudinal direction. The method includes a preparation step S02 for preparing the opening operation of the bag mouth B1, and an opening step S03 that is executed after the completion of the preparation step S02 and performs the opening operation of the bag mouth B1. Here, the preparation step S02 includes a first suction step S21 of sucking the back surface (second sheet member Bb), which is the side of the mounting table 10, to the bag body B placed on the mounting table 10 in a horizontal posture with the bag mouth B1 closed, a gripping step S22 of gripping both side edges B2·B2 in the width direction (left and right direction) orthogonal to the longitudinal direction (front and back direction) of the bag body B by a pair of gripping means 40·40, and a second suction step S23 of bringing the suction means 50 close to the surface (first sheet member Ba) opposite to the back surface (second sheet member Bb) of the bag body B and sucking the surface (first sheet member Ba) by the suction means 50. Further, the opening step S03 includes a first movement step S31 of moving a pair of gripping means 40·40 in a direction approaching each other, a second movement step S32 of moving the pair of gripping means 40·40 to the side opposite to the mounting table 10 side with respect to the bag body B, and a third movement step S33 of moving the suction means 50 to the side opposite to the mounting table 10 side with respect to the bag body B.

[0094] Further, the bag body opening device 1 in the present embodiment is a bag body opening device 1 for opening the bag mouth B1 of a bag body B formed in a rectangular long sheet shape and having the bag mouth B1 at one end side in the longitudinal direction. Here, the bag body opening device 1 includes a mounting table 10 for mounting the bag body B in a horizontal posture with the bag mouth B1 closed and sucking the back surface (second sheet member Bb), which is the mounting side of the bag body B, a pair of gripping means 40·40 for gripping both side edges B2·B2 in the width direction (left and right direction) orthogonal to the longitudinal direction (front and back direction) of the bag body B, and a suction means 50 for sucking the surface (first sheet member Ba) opposite to the back surface (second sheet member Bb) of the bag body B. In addition, the bag body opening device 1 includes a suction means moving mechanism 60 that enables the suction means 50 to move in a direction approaching and separating from the surface (first sheet member Ba) of the bag body B, first gripping means moving mechanisms 70·70 that enable the pair of gripping means 40·40 to move in a direction approaching and separating from each other, and second gripping means moving mechanisms 80·80 that enable the pair of gripping means 40·40 to move toward the mounting table 10 side and the side opposite to the mounting table 10 side with respect to the bag body B.

[0095] Thus, according to the bag body opening method and the bag body opening device 1 in the present embodiment, unlike the conventional method, the pair of suction cups (suction means) do not separate from each other (symmetrically separate) with respect to the bag (bag body) suspended in a vertical posture, but rather the back surface (second sheet member Bb) of the bag body B is sucked in a stable horizontal posture state placed on the mounting table 10 to securely hold the bag body B. When performing the opening operation of the bag mouth B1, only the suction means 50 that sucks the surface (first sheet member Ba) of the bag body B is moved to the side opposite to the mounting table 10 side (i.e., the upper side), and the bag body B1 can be stably opened.

[0096] In addition, when opening the bag mouth B1 of the bag body B held in a horizontal posture, the surface of the bag body B is curved so as to protrude upward, and the back surface of the bag body B is curved so as to protrude downward. Therefore, as the back surface is curved, it is necessary to relatively move the mounting table 10 away from the bag body B. In this regard, according to the bag body opening method and the bag body opening device 1 in the present embodiment, in the opening step S03, the pair of gripping means 40·40 that grip both side edges B2·B2 of the bag body B are moved in a direction approaching each other and also moved toward the side opposite to the mounting table 10 side (upper side), so that the mounting table 10 can be relatively moved away from the bag body B.

[0097] From these facts, according to the bag body opening method in the present embodiment, for example, even for a rectangular long sheet-shaped bag body B with a bag mouth B that is difficult to open and whose surface (first sheet member Ba) and back surface (second sheet member Bb) are each formed of different materials with different hardnesses, it can be surely opened.

[0098] Further, in the bag body opening method according to the present embodiment, in the opening step S03, the first moving step S31 and the second moving step S32 are executed simultaneously with each other.

[0099] Here, when a pair of gripping means 40·40 for gripping both side edges B2·B2 of the bag body B are moved in a direction approaching each other (first moving step S31) and then moved toward the side opposite to the mounting table 10 side (upper side) (second moving step S32), with the execution of the first moving step S31, the front surface (first sheet member Ba) and the back surface (second sheet member Bb) of the bag body are both curved so as to protrude upward, and there is a possibility that the adsorption state on the back surface of the bag body is peeled off (released). On the other hand, even when a pair of gripping means 40·40 for gripping both side edges B2·B2 of the bag body B are moved toward the side opposite to the mounting table 10 side (upper side) (second moving step S32) and then moved in a direction approaching each other (first moving step S31), with the execution of the second moving step S32, the front surface (first sheet member Ba) and the back surface (second sheet member Bb) of the bag body B are forcibly moved upward, and there is a possibility that the adsorption state on the back surface of the bag body B is peeled off (released).

[0100] Therefore, in the bag body opening method according to the present embodiment, when performing the opening operation of the bag mouth B1 of the bag body B, by performing the first moving step S31 and the second moving step S32 simultaneously, as the back surface (second sheet member Bb) of the bag body B is gradually curved so as to protrude downward, it becomes possible to appropriately move the mounting table 10 relatively away from the bag body B, and it is possible to prevent the adsorption state on the back surface of the bag body B from being peeled off (released).

[0101] Further, in the bag body opening method according to the present embodiment, in the second adsorption step S23, the adsorption means 50 adsorbs the bag body B within the range of the adsorption region Sa located at the center in the width direction (left - right direction) on the front surface (first sheet member Ba) of the bag body B on the bag mouth B1 side.

[0102] By having such a configuration, on the surface (first sheet member Ba) on the bag mouth B1 side of the bag body B, which is greatly deviated from the central portion in the width direction (left - right direction) and thermocompression - bonded, the suction means 50 can be adsorbed to either side in the width direction (left - right direction), and it is possible to prevent the occurrence of an opening operation error of the bag mouth B1.

[0103] Also, in the bag body opening method of the present embodiment, the dimension of the bag body B in the width direction (left - right direction) in the suction region Sa is set to 20% of the total length S of the bag body B in the width direction (left - right direction).

[0104] By having such a configuration, on the surface (first sheet member Ba) on the bag mouth B1 side of the bag body B, which is greatly deviated from the central portion in the width direction (left - right direction) and thermocompression - bonded, the suction means 50 can be adsorbed to either side in the width direction (left - right direction), and it is possible to more reliably prevent the occurrence of an opening operation error of the bag mouth B1.

[0105] Also, the bag body opening method in the present embodiment is executed after the completion of the preparation step S02, and further includes a jetting step S04 of jetting compressed air toward the inside of the bag body B through the bag mouth B1.

[0106] Also, the bag body opening device 1 in the present embodiment further includes a jetting means 90 for jetting compressed air toward the inside of the bag body B through the bag mouth B1.

[0107] By having such a configuration, it is possible to assist the opening operation of the bag mouth B1 of the bag body B by the suction means 50 and the pair of gripping means 40·40, and more reliably open the bag mouth B1.

[0108] Also, the bag body opening method in the present embodiment is executed before the start of the preparation step S02, and further includes a regulating step S01 of regulating the bag body B placed on the mounting table 10 to a predetermined position.

[0109] By having such a configuration, the opening operation of the bag mouth B1 of the bag body B can always be carried out at a predetermined position defined in advance, preventing unexpected malfunction of the suction means 50, the pair of gripping means 40·40, etc., and enabling the bag mouth B1 to be opened more reliably.

[0110] Further, in the bag body opening method of the present embodiment, the bag body B includes a first sheet member Ba forming the front surface and a second sheet member Bb forming the back surface, and either one of the first sheet member Ba and the second sheet member Bb is made of a plastic film, and the other of the first sheet member Ba and the second sheet member Bb is made of a non-woven fabric.

[0111] Even in the case of the rectangular long sheet-shaped bag body B with a bag mouth B1 that is difficult to open, in which the front surface (first sheet member Ba) and the back surface (second sheet member Bb) are each formed of different materials (plastic film and non-woven fabric) with different hardnesses from each other, according to the bag body opening method of the present embodiment, it can be surely opened.

Explanation of reference numerals

[0112] 1 Opening device 10 Mounting table 40 Gripping means 50 Suction means 60 Suction means moving mechanism 70 First gripping means moving mechanism 80 Second gripping means moving mechanism 90 Ejection means B Bag body B1 Bag mouth B2 Both side edge portions Ba First sheet member Ba (front surface) Bb Second sheet member Bb (back surface) S Overall length S01 Regulation process S02 Preparation process S03 Opening process S04 Ejection process S21 First suction step S22 Gripping step S23 Second suction step S31 First movement step S32 Second movement step S33 Third movement step Sa Suction area

Claims

1. A method for opening a bag body having a bag mouth at one end in the longitudinal direction, the bag body being formed in a rectangular sheet shape, the method comprising: a preparation step of preparing for the opening operation of the bag mouth; an opening step that is executed after the completion of the preparation step and performs the opening operation of the bag mouth, wherein the preparation step a first suction step of sucking the back surface, which is the mounting table side, of the bag body placed on the mounting table in a horizontal posture with the bag mouth closed by a bottomed hole provided on the upper surface of the mounting table; a gripping step of gripping both side edges in the width direction orthogonal to the longitudinal direction of the bag body by a pair of gripping means; a second suction step of bringing a suction means close to the surface of the bag body opposite to the back surface and sucking the surface by the suction means, wherein the opening step a first movement step of horizontally moving the pair of gripping means in a direction approaching each other; a second movement step of vertically moving the pair of gripping means to the side opposite to the mounting table side with respect to the bag body; a third movement step of moving the suction means to the side opposite to the mounting table side with respect to the bag body, wherein the bag body comprises a first sheet member forming the surface and a second sheet member forming the back surface; either one of the first sheet member and the second sheet member is made of a plastic film, and the other of the first sheet member and the second sheet member is made of a non-woven fabric, in the second suction step, the suction means sucks the bag body within the range of the suction area located at the center in the width direction on the surface of the bag body on the bag mouth side, and the dimension in the width direction of the bag body in the suction area is set to 20% of the total length in the width direction of the bag body, characterized in that it is a method for opening a bag body.

2. In the opening step, the first movement step and the second movement step are executed simultaneously with each other, characterized in that it is the method for opening a bag body according to Claim 1.

3. which is executed after the completion of the preparation step, further comprising a jetting step of jetting compressed air toward the inside of the bag body through the bag mouth, characterized in that it is the method for opening a bag body according to Claim 1 or Claim 2.

4. which is executed before the start of the preparation step, further comprising a restricting step of restricting the bag body placed on the mounting table to a predetermined position, characterized in that it is the method for opening a bag body according to any one of Claims 1 to 3.

5. A bag body opening device for a bag body formed in a rectangular sheet shape and having a bag mouth at one end in the longitudinal direction, the device opening the bag mouth, a mounting table provided on the upper surface thereof, having a bottomed hole portion for mounting the bag body in a state where the bag mouth is closed in a horizontal posture and sucking the back surface which is the mounting side of the bag body, a pair of gripping means for gripping both side edges in the width direction orthogonal to the longitudinal direction of the bag body, a suction means for sucking the surface of the bag body opposite to the back surface, a suction means moving mechanism for enabling the suction means to move in a direction approaching and separating from the surface of the bag body, a first gripping means moving mechanism for enabling the pair of gripping means to move horizontally in a direction approaching and separating from each other, a second gripping means moving mechanism for enabling the pair of gripping means to move vertically with respect to the bag body toward the mounting table side and the side opposite to the mounting table side, and the bag body includes a first sheet member forming the surface and a second sheet member forming the back surface, either one of the first sheet member and the second sheet member is made of a plastic film, and the other of the first sheet member and the second sheet member is made of a non-woven fabric, the suction means sucks the bag body within the range of a suction area located at the center in the width direction on the surface of the bag body on the bag mouth side, and the dimension of the bag body in the width direction in the suction area is set to 20% of the total length of the bag body in the width direction, characterized in that it is a bag body opening device.

6. Further comprising ejection means for ejecting compressed air toward the inside of the bag body through the bag mouth, characterized in that it is the bag body opening device according to claim 5.

Images