Gusset molding mechanism, seal device, packaging machine, and gusset molding method

Abstract

To provide a gusset molding mechanism capable of sufficient bleeding in a packaging material, and capable of preventing positional deviation of an article in the packaging material, to provide a seal device, to provide a packaging machine and to provide a gusset molding method.SOLUTION: A gusset molding mechanism 200 encloses an article XA1, and folds the packaging material YA1 and molds a gusset GA when sealing a cylindrical packaging material YA1 continued in a first direction by sealers 120, 160. The gusset molding mechanism 200 has: push-in means 300 for pushing in the packaging material YA1 by pushing the lateral side of the packaging material YA1 from the outside to the inside along a second direction crossing the first direction; and a movement mechanism 230 of the push-in means 300. The push-in means 300 has: a first push-in part 301 for pushing in the packaging material YA1 in the vicinity of the sealers 120, 160; and a second push-in part 302 for pushing in the packaging material YA1 at ta position closer to the article XA1 than the first push-in part 301 in the first direction.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a gusset forming mechanism, a sealing device, a packaging machine, and a gusset forming method for forming a gusset when sealing a packaging material.

Background Art

[0002] In a packaging machine for pillow-packaging articles such as foods and daily necessities, the articles are continuously supplied to the packaging machine, and these articles are individually pillow-packaged with a packaging material to produce a package. In pillow packaging, when sealing the packaging material with a sealer, a pushing portion (gusset claw) may be inserted into a tubular packaging material to form a gusset (seam) (see, for example, Patent Document 1). In the gusset forming mechanism described in Patent Document 1, a V-shaped gusset claw conforming to the shape of the gusset is formed by two plates, and the side of the packaging material is pushed in this way.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional gusset forming mechanism, there has been a problem that air evacuation in the packaging material is insufficient and minimization of the volume as a package is not advanced. In the conventional mechanism, although air is locally evacuated at the portion where the gusset claw pushes the packaging material, the air moves to the portions where the gusset claw does not contact the packaging material (for example, the upstream side and the downstream side of the article). Since sealing (top seal, end seal) is performed in that state, an air pocket in which a predetermined amount of air remains is generated in the package. For example, when a plurality of completed pillow packages are stacked (for example, housed in a box), the gusset is folded to minimize the volume of each pillow package, but if air evacuation in the package is insufficient, there is a limit to volume minimization.

[0005] Alternatively, in the conventional gusset forming mechanism, displacement of the article in the packaging material may occur. In the case of a package forming a gusset, a larger margin before and after the article is ensured compared to a package not forming a gusset. However, since the gusset claw locally pushes the packaging material in the region other than the article housing portion, or is pushed by the generated air pocket, movement (displacement) of the article is likely to occur. As a result, there has been a problem that the article is pinched in the seal portion.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a gusset forming mechanism, a sealing device, a packaging machine, and a gusset forming method capable of sufficiently evacuating air in a packaging material and preventing displacement of an article in the packaging material.

Means for Solving the Problems

[0007] The present invention relates to a gusset forming mechanism for folding a packaging material to form a gusset when sealing a tubular packaging material that encloses an article and is continuous in a first direction with a sealer, the gusset forming mechanism having pushing means for pushing the side of the packaging material from the outside to the inside along a second direction intersecting the first direction, and a moving mechanism for the pushing means, the pushing means having a first pushing portion for pushing the packaging material in the vicinity of the sealer, and a second pushing portion for pushing the packaging material at a position closer to the article than the first pushing portion in the first direction.

[0008] The present invention also relates to a sealing device characterized by comprising the above-described gusset forming mechanism and the sealer.

[0009] The present invention also relates to a packaging machine having the above-described gusset forming mechanism.

[0010] The present invention also relates to a gusset forming method for folding a packaging material to form a gusset when sealing a tubular packaging material that encloses an article and is continuous in a first direction with a sealer, the method including a step of pushing the side of the packaging material from the outside to the inside along a second direction intersecting the first direction by a first pushing portion, and a step of pushing the side of the packaging material at a position closer to the article than the first pushing portion in the first direction along the second direction by a second pushing portion. The second pushing portion pushes a part of the packaging material that has been folded by the first pushing portion and has become valley-shaped, and relates to a gusset forming method characterized by this.

Effect of the Invention

[0011] According to the present invention, it is possible to provide a gusset forming mechanism, a sealing device, a packaging machine, and a gusset forming method that enable sufficient air venting inside the packaging material and prevent displacement of the article inside the packaging material.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0013] Hereinafter, with reference to the drawings, the configuration of the packaging machine 1 according to an embodiment of the present invention will be described. FIG. 1 is a schematic diagram of the packaging machine 1. Further, FIG. 2 is an external perspective view of the package ZA1 packaged by the packaging machine 1 viewed from below. In this figure and the following figures, some configurations are appropriately omitted to simplify the drawings. And in this figure and the following figures, the size, shape, thickness, etc. of the members are exaggerated as appropriate for expression.

[0014] The packaging machine 1 shown in Fig. 1 is used in a line for successively packaging the article XA1 with the packaging material YA1. This packaging machine 1 includes an article supply device 2, a packaging material supply device 3, a packaging machine main body 4, a control unit (not shown), etc. As for the definitions of various directions in the packaging machine main body 4, the first direction, which is the longitudinal direction of the strip-shaped packaging material YA1 (the direction in which the center seal extends), is defined as the transport direction L, the second direction, which is the width direction of the packaging material YA1 (the direction in which the top seal extends), is defined as the transport width direction W, and the third direction, which is orthogonal to the first and second directions, is defined as the transport height direction H. Also, the transport direction L, the transport width direction W, and the transport height direction H refer to both directions without distinction between positive and negative. For example, the transport direction L refers to both the direction from upstream to downstream and the direction from downstream to upstream, the transport width direction W refers to both the direction from the center of the packaging material YA1 to the side end and the opposite direction, and the transport height direction H refers to both the direction from top to bottom and the direction from bottom to top.

[0015] Each part of these packaging machines 1 is comprehensively controlled by a control unit. The control unit is composed of a CPU, a RAM, a ROM, etc., and executes various controls. The CPU is a so-called central processing unit, and various programs are executed to realize various functions. The RAM is used as the working area of the CPU. The ROM stores the basic OS and programs executed by the CPU.

[0016] The article supply device 2 transports the article XA1 at equal intervals and successively transports the article XA1 to the downstream packaging machine main body 4. This article supply device 2 is composed of, for example, a finger conveyor. Specifically, the article supply device 2 includes a transport surface (reference numeral omitted) having slits, a side guide (not shown) for guiding the article XA1 on this transport surface from the side, a driving sprocket 5, a driven sprocket (not shown), an annular chain 6 that runs over these sprockets, a plurality of fingers 7 attached to this chain 6 at equal intervals, a servo motor (not shown) serving as a power source, etc. The plurality of fingers 7 push the article XA1 on the transport surface and send it out to the packaging machine main body 4.

[0017] The packaging material supply device 3 continuously supplies the packaging material YA1 to the downstream packaging machine main body 4. The packaging material supply device 3 includes an unwinding shaft 8, a servo motor (not shown), guide rollers 9a, 9b, etc. The unwinding shaft 8 rotatably holds the unwinding roll YB1. This unwinding shaft 8 is powered by a servo motor to rotate and rotate the held unwinding roll YB1. Thereby, the packaging material YA1 is fed out from the unwinding roll YB1. The guide rollers 9a, 9b appropriately convert the conveyance direction of the unwinding roll YB1 and guide it to the side of the packaging machine main body 4.

[0018] In addition, as a method of feeding out the packaging material YA1 from the unwinding roll YB1, instead of adopting the above-described unwinding drive type method, a feed roller may be separately provided, and a feed roller drive type method of moving the feed roller to pull out the packaging material YA1 may be adopted.

[0019] The packaging machine main body 4 packages the article XA1 supplied from the article supply device 2 with the packaging material YA1 supplied from the packaging material supply device 3. Specifically, the packaging machine main body 4 includes a bag former 14, pinch rollers 15, a center seal device 16, a first conveyance device 17, an upper pressing device 18, a top seal device 100, a second conveyance device 20, etc.

[0020] The bag former 14 forms a bag in a tubular shape so that both ends in the width direction of the packaging material YA1 supplied from the packaging material supply device 3 overlap each other. Also, the bag former 14 supplies the article XA1 supplied from the article supply device 2 to the packaging material YA1 formed into a tubular shape. Thereby, the article XA1 is wrapped in the packaging material YA1 formed into a tubular shape. That is, the bag former 14 functions as a bag forming device that bends the packaging material YA1 in the width direction and forms it into a tubular shape.

[0021] The pinch rollers 15 sandwich both ends of the overlapping packaging material YA1 (hereinafter referred to as the center seal portion CE1 (see FIG. 2)) and apply a conveying force to the center seal portion CE1.

[0022] The center seal device 16 includes a pair of bar sealers 16a and a press roller 16b. This center seal device 16 heats the center seal portion by sandwiching it with a pair of bar sealers 16a. Then, the center seal device 16 crimps the heated center seal portion with the press roller 16b to perform center sealing.

[0023] The first conveyor 17 places the center-sealed cylindrical packaging material YA1 together with the article XA1 wrapped by the packaging material YA1 on a conveying surface (reference numeral omitted) and conveys it toward the top seal device 100. This first conveyor 17 expands and contracts the conveying surface in the conveying direction L in accordance with the box motion of the top seal device 100.

[0024] The upper holding device 18 is disposed above the first conveyor 17 and holds the article XA1 conveyed to the first conveyor 17 together with the packaging material YA1 from above. Thereby, the article XA1 is conveyed while maintaining a horizontal state.

[0025] The top seal device 100 seals (also referred to as end seal and side seal) and cuts in the conveying width direction W at a pitch corresponding to the length of the article XA1. Thereby, as shown in FIG. 2, a top seal portion TO1 is formed and the package ZA1 is manufactured. The direction in FIG. 2 is shown as the direction during conveyance by the second conveyor 20. At both ends in the width direction (conveying width direction W) of the top seal portion TO1, the packaging material YA1 is folded inward so as to form a substantially triangular pyramid-shaped recess, thereby forming a gusset GA. The space between the gussets GA before and after in the conveying direction L (a rectangular parallelepiped-shaped space in this example) is the accommodation portion CN for the article XA1. Since the gusset GA is a three-dimensional region, it is possible for a part of the article XA1 to be accommodated (received) (for example, by moving within the package ZA1), but the accommodation portion CN in the present embodiment refers to a three-dimensional space that can surely accommodate the article XA1 even when the gusset GA is folded in the conveying direction L.

[0026] FIG. 3 is a view showing a gusset forming mechanism 200 employed in the top seal device 100. FIG. 3(A) is a front view of the top seal device 100 viewed from the downstream side in the conveying direction L with the sealers 120 and 160 separated, and FIG. 3(B) is a front view of the sealers 120 and 160 in the approaching state.

[0027] The top seal device 100 includes a first sealer 120 disposed on the upper side, a second sealer 160 disposed on the lower side, and a moving device (not shown) for relatively moving them. The first sealer 120 and the second sealer 160 are disposed so as to face both sides (upper and lower) in the conveying height direction H of the packaging material YA1, and approach and separate from each other by the moving device. Note that a cutter unit (not shown) is provided in the first seal unit (not shown) including the first sealer 120.

[0028] Since the drive mechanism of the pair of sealers (the first sealer 120 and the second sealer 160) in the top seal device 100, and the operations of sealing and cutting are of known configurations, the description thereof is omitted. The top seal device 100 further has a gusset forming mechanism 200. This gusset forming mechanism 200 is constituted by, for example, a pair of gusset units 210 disposed on both outer sides in the conveying width direction W of the packaging material YA1. When the gusset unit 210 seals the cylindrical packaging material YA1 that encloses the article XA1 and is continuous in the conveying direction L with a sealer (the first sealer 120 and the second sealer 160), the gusset GA (see FIG. 2) is formed in the package ZA1 by folding a pair of side surfaces in the conveying width direction W of the packaging material YA1 inward.

[0029] As shown in FIG. 3(A), the pair of gusset units 210 are disposed on one side and the other side in the conveying width direction W, and each has a gusset claw 300 serving as a pushing means and a moving mechanism (advancing and retracting mechanism) 230 for advancing and retracting the gusset claw 300 in the conveying width direction W. The pair of gusset units 210 have the same configuration and are disposed symmetrically (oppositely) with respect to the center line in the conveying direction L.

[0030] The moving mechanism 230 includes, for example, a guide rail 232 extending in the conveyance width direction W, a slider 234 movably disposed along the guide rail 232, a slide plate 236 vertically fixed to the slider 234, a motor 238, and a swing shaft 239. One end of the swing shaft 239 is fixed to the motor 238, and a pin is disposed at the other end. This pin is inserted into a vertical long hole 236A of the slide plate 236. Thereby, an orthogonal slide mechanism that converts rotational motion (forward and reverse rotation) into reciprocating motion is configured in the moving mechanism 230. When the swing shaft 239 rotates by the motor 238, the pin moves within the long hole 236A, and the slide plate 236 and the slider 234 reciprocate in the conveyance width direction W. Here, a structure that swings the swing shaft 239 is illustrated as the moving mechanism 230, but it is not limited to this example as long as it is a moving mechanism that moves the gusset claw 300 forward and backward in the conveyance width direction W. For example, an air cylinder or a cam mechanism can also be employed.

[0031] As shown in FIG. 3(A), in the vicinity before and after the timing when a pair of sealers (the first sealer 120 and the second sealer 160) approach the packaging material YA1 along the conveyance height direction H and contact the packaging material YA1, the gusset forming mechanism 200 causes the gusset claws 300 to enter inward from both sides in the conveyance width direction W.

[0032] Next, the first sealer 120 and the second sealer 160 approach each other and push the side of the packaging material YA1 inward. At the same time, the gusset forming mechanism 200 causes the gusset claws 300 to further enter inward. The gusset claws 300 abut against the side of the packaging material YA1 in the conveyance width direction W and deform it inward.

[0033] Thereafter, as shown in FIG. 3(B), the first sealer 120 and the second sealer 160 come closer, sandwich the packaging material YA1 at the contact position T, and perform heat sealing and cutting. The portion pushed in by the gusset claws 300 becomes a non-sealing area, and a gusset GA (for example, in a substantially triangular pyramid shape) is formed along the shape of the gusset claws 300 (see FIG. 2).

[0034] Referring to FIGS. 4 and 5, the gusset forming mechanism 200 will be described. FIG. 4 is a perspective view of the gusset unit 210 disposed on the right side shown in FIG. 3 as an example. Further, FIG. 5(A) is a top view of the gusset claw 300 in FIG. 4 viewed from above in the conveying height direction H, FIG. 5(B) is a side view of FIG. 5(A) viewed from the left side in the conveying width direction W, and FIG. 5(C) is a front view of the gusset claw 300 viewed from the downstream side (lower side) in the conveying direction L of FIG. 5(A).

[0035] The gusset claw 300 is a pushing means for pushing both sides in the conveying width direction W of the packaging material YA1 from the outside to the inside along the conveying width direction W. Hereinafter, the direction in which the gusset claw 300 pushes the packaging material YA1 is particularly referred to as the pushing direction P. The pushing direction P is a direction parallel to the conveying width direction W. While the conveying width direction W has no distinction between positive and negative, the pushing direction P is a direction from the outside to the inside of the packaging material YA1 as indicated by the arrow in FIGS. 4 and 5(A) (from right to left in FIG. 5(A)).

[0036] As shown in FIG. 4, the gusset claw 300 of the present embodiment is composed of an upstream gusset claw 300A that pushes the packaging material YA1 to the inside in the conveying width direction W upstream of the pair of sealers (the first sealer 120 and the second sealer 160), and a downstream gusset claw 300B that pushes the packaging material YA1 to the inside in the conveying width direction W downstream of the pair of sealers.

[0037] Here, instead of showing the pair of sealers (the first sealer 120 and the second sealer 160), the contact position T defined as the spatial location where the strip-shaped seal surfaces of the pair of sealers come into contact is shown.

[0038] On one side in the conveying width direction W, the upstream gusset claw 300A and the downstream gusset claw 300B are integrally connected by a support member 300C and move forward and backward in the same direction simultaneously. Similarly, on the other side in the conveying width direction W, the upstream gusset claw 300A and the downstream gusset claw 300B are integrally connected by a support member and move forward and backward in the same direction simultaneously. Since the configurations of the upstream gusset claw 300A and the downstream gusset claw 300B are the same, they will be hereinafter simply referred to as the gusset claw 300 for description.

[0039] The gusset claw 300 of the present embodiment has a first pushing portion 301 and a second pushing portion 302. The first pushing portion 301 is a means for pushing the packaging material YA1 in the vicinity of the first sealer 120 and the second sealer 160. In this example, the tip in the pushing direction P is configured in a arrowhead shape that is pointed. More specifically, the first pushing portion 301 of the upstream gusset claw 300A is constituted by a V-shaped plate member that inclines such that the distance in the conveying height direction H gradually increases as it goes from the downstream side to the upstream side along the conveying direction L. Also, the first pushing portion 301 of the downstream gusset claw 300B is constituted by a V-shaped plate member that inclines such that the distance in the conveying height direction H gradually increases as it goes from the upstream side to the downstream side along the conveying direction L.

[0040] The position of the V-shaped valley portion of the first pushing portion 301 is the position that is the center in the conveying height direction H of the packaging material YA1 (see FIG. 3), and is the position in the horizontal plane of the contact position T of the pair of sealers (the first sealer 120, the second sealer 160) (defined as the place in space where the strip-shaped seal surface contacts) (see FIG. 4).

[0041] Referring to FIG. 5, the V-shaped plate member constituting the first pushing portion 301 is formed by connecting the bottom sides of two substantially trapezoidal plate members to each other so that a predetermined angle α (FIG. 5(B)) is formed therebetween (bent around the bottom side). At least a part of the edge 301E of the first pushing portion 301 facing the packaging material YA1 in front of the pushing direction P abuts on the packaging material YA1 and pushes it in. The edge 301E in this example is also V-shaped when viewed in the conveying width direction W (FIG. 5(B)). In other words, the edge 301E is composed of two first edges 301e1 and 301e2 of two substantially trapezoidal plate members. The edge 301 (first edges 301e1, 301e2) refers to, for example, an edge parallel to the conveying direction L or an edge having a component parallel to the conveying direction L. When one end of the bottom side of the trapezoid (front end in the pushing direction P) is used as the base end SE, the two first edges 301e1 and 301e2 are opened in a direction in which the tip ends TE are separated from each other along the conveying height direction H.

[0042] The second pushing portion 302 is provided at a position closer to the article XA1 than the first pushing portion 301 in the conveying direction L (direction along) so as to be able to push the packaging material YA1. The second pushing portion 302 has an edge (second edge) 302e that extends along the conveying direction L and at least a part of which abuts on a part of the packaging material YA1. In this example, the second pushing portion 302 is a trapezoidal or rectangular plate member and is provided at a position near the center in the conveying height direction H of the packaging material YA1 (see FIG. 4). One side that is located in front of the pushing direction P of the second pushing portion 302 and extends in the conveying direction L is the second edge 302e. The second edge 302e refers to, for example, an edge parallel to the conveying direction L or an edge having a component parallel to the conveying direction L. The second pushing portion 302 in this example is a trapezoidal plate member in which the second edge 302e is inclined with respect to the conveying direction L and / or the conveying width direction W (has a component parallel to the conveying direction L).

[0043] When a virtual plane (indicated by a dashed line in FIGS. 5(A) and 5(C)) including two first edges 301e1 and 301e2 in the first pushing portion 301 is defined as the first virtual plane V1, the second edge 302e protrudes from the first virtual plane V1 toward the inner side of the packaging material YA1 (in both the conveying direction L and the conveying width direction W).

[0044] Alternatively, when a plane obtained by virtually expanding the first virtual plane V1 in the first pushing portion 301 in the direction of the tip TE of the first edges 301e1 and 301e2 is defined as the second virtual plane V2 (indicated by a two-dot chain line in FIGS. 5(A) and 5(C)), the second edge 302e may protrude from the second virtual plane V2 toward the inner side of the packaging material YA1 (in both the conveying direction L and the conveying width direction W).

[0045] As shown in FIG. 5(A), in a state where the gusset claw 300 is used, in a plan view seen from above in the conveying height direction H, the two first edges 301e1 and 301e2 generally overlap in the conveying height direction H. The first virtual plane V1 and the second virtual plane V2 are planes perpendicular to the conveying plane composed of the conveying direction L and the conveying width direction W, and are planes inclined with respect to the conveying width direction W. And, as the positional relationship in the conveying width direction W with respect to the packaging material YA1 (side surface) indicated by the broken line, the tip P1 of the V-shaped valley portion of the first pushing portion 301 is close to the packaging material YA1, and the second edge 302e (the position P2 at the most forward in the pushing direction P) of the second pushing portion 302 is at a position far from the packaging material YA1. Hereinafter, the tip P1 is referred to as the tip P1 of the first pushing portion, and the position P2 is referred to as the tip P2 of the second pushing portion. A part of the inclined region R0 constituting the first edges 301e1 and 301e2 exists between the tip P1 of the first pushing portion and the tip P2 of the second pushing portion.

[0046] In the present embodiment, when the gusset claw 300 moves in the pushing direction P, at least a part of the tip P1 of the first pushing portion, at least a part of the inclined region R0 (a portion continuous with the tip P1 of the first pushing portion), and at least a part of the second edge 302e come into contact with the packaging material YA1 in this order and push it inward.

[0047] By protruding a part of the second pushing part 302 (in this case, a part of the second edge 302e) from the virtual plane V1 (or virtual plane V2), the second pushing part 302 can push the packaging material YA1 at a position closer to the article XA1 than the first pushing part 301 in the conveying direction L (the direction along it).

[0048] Then, by pushing the packaging material YA1 at a position closer to the article XA1 than the first pushing part 301 with the second edge 302, it becomes possible to sufficiently remove the air inside the packaging material YA1, and it is possible to minimize the volume as the package ZA1.

[0049] Alternatively, the article XA1 can be moved downstream by the second edge 302e, and the positions of the article XA1 on the downstream side inside the packaging material YA1 can be aligned. Therefore, the movement (displacement) of the article XA1 can be avoided, and the intrusion of the article XA1 at the top seal part TO1 can be prevented.

[0050] Referring to FIG. 6, a method for forming the gusset GA by the gusset forming mechanism 200 and the operation of the second pushing part 302 will be described. FIG. 6 is a top (planar) view seen from the conveying height direction H near a pair of gusset claws 300 arranged in the conveying width direction W. Also, in FIG. 6, the left side is the upstream side in the conveying direction L, and the right side is the downstream side in the conveying direction L.

[0051] FIG. 6(A) shows a state in which the first sealer 120 and the second sealer 160 (indicated by the contact area T) are separated in the conveying height direction H (see FIG. 3(A)). In this state, the gusset forming mechanism 200 has the gusset claws 300 (the upstream gusset claw 300A and the downstream gusset claw 300B) waiting outside the lateral sides (opposite both side surfaces) of the packaging material YA1 formed in a cylindrical shape in the conveying width direction W.

[0052] Thereafter, when the first sealer 120 and the second sealer 160 seal the cylindrical packaging material YA1, the gusset forming mechanism 200 folds the packaging material YA1 to form a gusset. Specifically, when the first sealer 120 and the second sealer 160 approach the packaging material YA1 along the conveying height direction H, the gusset forming mechanism 200 causes the gusset claws 300 (the upstream gusset claw 300A and the downstream gusset claw 300B) to enter inward from both sides in the conveying width direction W, and deforms a part of the side of the packaging material YA1 (near the center in the conveying height direction H) inward as shown by the broken line in FIG. 6(B). Further, the first sealer 120, the second sealer 160, and the gusset claws 300 contact the cylindrical packaging material YA1 almost simultaneously.

[0053] In the pushing direction P (indicated by the arrow in FIG. 6(B)), first, the tip P1 of the first pushing portion contacts the packaging material YA1 and pushes it inward (in the pushing direction P).

[0054] Subsequently, while the first sealer 120 and the second sealer 160 are approaching the packaging material YA1 along the conveying height direction H until they contact the packaging material YA1, the gusset forming mechanism 200 causes the gusset claws 300 (the upstream gusset claw 300A and the downstream gusset claw 300B) to further enter inward as shown in FIG. 5(C). Although omitted for schematic illustration in FIG. 5(C), a part of the inclined region R0 contacts the packaging material YA1 (the folded part that becomes the valley side) at a position shifted vertically from the tip P1 of the first pushing portion in the conveying height direction H and pushes it inward. Subsequently, in this example of the second pushing portion 302, the second edge 302e contacts the packaging material YA1 and pushes it inward (in the pushing direction P). The position where the second edge 302e contacts and pushes the packaging material YA1 is closer to the article XA1 than the position where the tip P1 of the first pushing portion pushes the packaging material YA1.

[0055] The second pressing part 302 (second edge 302e) presses a part of the packaging material YA1 that has been folded into a valley shape by the first pressing part 301. Also, the second pressing part 302 starts to press the packaging material YA1 while the gusset claw 300 is moving in the pressing direction P, and at the latest when the pressing amount of the first pressing part 301 reaches its maximum (for example, in FIG. 6(C)), it is configured to press a part on the side of the packaging material YA1.

[0056] By the pressing of the second pressing part 302, a part of the air inside the packaging material YA1 is discharged to the outside of the packaging material YA1. Also, by the pressing of the second pressing part 302, the articles XA1 in the packaging material YA1 can be aligned or displacement can be prevented.

[0057] After that, the first sealer 120 and the second sealer 160 come closer, and the gusset claw 300 is retracted immediately before sealing. Then, the packaging material YA1 is clamped at the contact position T, and the hatched area is heat-sealed and cut (see FIG. 3(B)).

[0058] FIG. 7 is a plan view showing a state in which a gusset is formed by a gusset claw 350 (for example, a conventional configuration) that does not have the second pressing part 302 as a comparative example. The gusset claw 350 is composed of, for example, only the first pressing part 301 of the present embodiment. In this case, although air is locally removed in the part where the packaging material YA1 is pressed by the gusset claw 350, the air moves to the parts where the gusset claw 350 does not contact the packaging material YA1 (for example, the upstream side of the downstream article XA1 and the downstream side of the upstream article XA1). Since sealing is performed by the sealer S in that state, an air accumulation AB in which a predetermined amount of air remains is generated inside the packaging material YA1. For example, when a plurality of completed pillow packages are stacked (for example, housed in a box), even if an attempt is made to fold the gusset to minimize the volume of each pillow package, there is a limit to minimizing the volume due to the air accumulation AB.

[0059] Alternatively, in the case of a package forming a gusset, a larger margin before and after the article is ensured compared to a package that does not form a gusset. However, since the gusset claw 350 locally pushes in the packaging material YA1 in a region other than the accommodating portion of the article XA1, or the generated air pocket AB easily causes the article XA1 to move (shift in position). As a result, there has been a problem that the article XA1 is indented at the seal portion.

[0060] In the present embodiment, as shown in FIGS. 6(B) and 6(C), in the first pushing portion 301, the tip P1 of the first pushing portion first contacts the side surface of the packaging material YA1 and pushes the packaging material YA1 inward. Also, as the pushing amount increases, at least a part of the inclined region R0 (the first edge 301e1, 301e2) of the first pushing portion 301 contacts the packaging material YA1, and the packaging material YA1 is pushed inward without slack. Further, as the pushing amount increases, the second pushing portion 302 pushes the packaging material YA1, and before the sealing by the sealer, the air before and after the article XA1 is pushed out to the outside of the packaging material YA1. Thereafter, by performing the sealing, a gusset GA without wrinkles can be formed, and the generation of an air pocket AB near the gusset GA can also be avoided. As a result, the volume of the package ZA1 can be minimized, and the positions of the articles XA1 in the package ZA1 can be aligned (position shift can be prevented).

[0061] FIG. 8 is a plan view showing the positional relationship of the gusset claw 300 (particularly the second pushing portion 302) with respect to the packaging material YA1 (or the completed package ZA1) after the gusset GA is formed. The thick broken line in FIG. 8 indicates the position of the valley of the folded gusset GA.

[0062] As shown in FIG. 8(A), at least a part (second edge 302e) of the second pushing portion 302 of the present embodiment protrudes from the virtual surface V1 of the first pushing portion 301 in the inner direction of the packaging material YA1. Further, with respect to the packaging material YA1, the second edge 302e is configured to enter more from the center in the conveyance width direction W than the side of the packaging material YA1 (particularly, the side surface SS of the accommodation portion CN (see also FIG. 2) other than the gusset GA portion). By adopting such a configuration, it becomes possible to discharge the air near the broken-line circle mark, which has occurred conventionally, to the outside of the packaging material YA1.

[0063] In the above example, the case where the second pushing portion 302 is constituted by a plate member having a substantially trapezoidal shape (a shape in which the second edge 302e is inclined with respect to the conveyance direction L and / or the conveyance width direction W) in plan view has been described. However, the second pushing portion 302 may be a plate member in which the second edge 302e is parallel to the conveyance direction L.

[0064] Further, at least a part of the second pushing portion 302 may protrude from the virtual surface V1 or the virtual surface V2 of the first pushing portion 301 in the inner direction of the packaging material YA1, and / or with respect to the packaging material YA1, the second edge 302e may be configured to enter more from the center in the conveyance width direction W than the side of the packaging material YA1 (particularly, the side surface SS of the accommodation portion CN other than the gusset GA portion).

[0065] FIG. 8(B) is a plan view showing another example of the second pushing portion 302. The first pushing portion 301 may have any shape that can locally push the packaging material YA1 during the formation of the gusset GA. For example, the shape of the arrowhead may be smaller than the size of the gusset GA to be formed.

[0066] In that case, the second pushing portion 302 may be configured to protrude in the inner direction (conveying direction L and conveying width direction W) of the packaging material YA1 from a virtual surface V2 (indicated by a two-dot chain line) that extends the virtual surface V1. Further, the shape of the second pushing portion 302 may be a plate member attached to the tip of an extension member 306 attached to the first pushing portion 301 or its support portion 305 as shown in FIG. 8(B). In this case, the front in the pushing direction P of the second pushing portion 302 (plate member) is the second edge 302e.

[0067] Alternatively, the second pushing portion 302 may be a sphere or the like attached to the tip in the pushing direction P of the plate member shown in FIG. 8(B), or may be a sphere or the like attached to the tip of the extension member 306 instead of the plate member.

[0068] Furthermore, the first pushing portion 301 is not limited to the three-dimensional arrowhead shape (V-shaped) as shown in FIG. 8, and may be a claw portion formed of a rod-shaped member or a flat plate (strip) - shaped member. In that case (in the case of a configuration where the virtual surfaces V1 and V2 cannot be assumed), the second pushing portion 302 may be configured such that the second edge 302e enters more into the center in the conveying width direction W than the side of the packaging material YA1 (particularly, other than the gusset GA portion, for example, the side surface SS of the accommodating portion CN).

[0069] <Other Embodiments> As another embodiment of the present invention, with reference to FIGS. 9 to 11, an example of forming a gusset GA on a packaging material YA1' having a corner seal portion HE will be described.

[0070] FIG. 9 illustrates the configuration of a packaging material YA1' in which corner seal portions HE1 to HE4 are formed. FIG. 2 is a perspective view of the back surface of the packaging material YA1' in which corner seal portions HE1 to HE4 are formed.

[0071] The packaging material YA1' is formed with a plurality (four in this embodiment) of corner seal portions HE1 to HE4 along the conveyance direction L, with spaces therebetween. In this case, in FIG. 1, the packaging material supply device 3 sends out the packaging material YA1' fed out from the raw material roll YB1 to a corner seal portion forming means (not shown) provided upstream of the bag making device 14. The corner seal portion forming means forms a plurality (four in this embodiment) of corner seal portions HE1 to HE4 along the conveyance direction L on the packaging material YA1', either simultaneously or stepwise, with spaces therebetween. Specifically, the corner seal portion forming means forms the corner seal portions HE1 to HE4 by, for example, at least folding the strip-shaped packaging material YA1' into an outer three-fold in the longitudinal direction (conveyance direction L) so as to be continuous and laying it down horizontally, forming folds, and then heat-sealing the folds in the laid-down state. Thereafter, the corner seal portion forming means sends out the packaging material YA1' with the corner seal portions HE1 to HE4 formed to the packaging machine main body 4.

[0072] FIG. 10 is a view for explaining the package ZA1' formed by the packaging material YA1' of FIG. 9. FIG. 10(A) is an external perspective view of the package ZA1' viewed from below, and FIG. 10(B) is a cross-sectional view of the package ZA1'.

[0073] Corner seal portions HE1 to HE4 are formed at the four corners of the package ZA1' along the conveyance direction L. And on the bottom surface of the package ZA1, one center seal portion CE1 is formed along the conveyance direction L so as to be parallel to the corner seal portions HE1 to HE4. Also, a pair of top seal portions TO1 are formed at both ends of the package ZA1' in the conveyance direction L.

[0074] The corner seal portions HE1 to HE4 are highly rigid and can easily maintain the outer shape of the package ZA1' in a rectangular parallelepiped (cube) shape. There are advantages such as increased strength at the corners of the package ZA1', better appearance, and making the package ZA1' look larger. On the other hand, due to the increased rigidity at the corners of the package ZA1' and the protrusion of the highly rigid corner seal portions HE1 to HE4 in the conveyance width direction W (Figure 10(B)), there is a problem that it becomes difficult to form the gusset GA that folds the side of the packaging material YA1'.

[0075] Also, when the height of the tubular packaging material YA1 changes due to the displacement of the formation positions of the corner seal portions HE1 to HE4 by the corner seal portion forming means, wrinkles may occur during gusset forming.

[0076] Specifically, in the case of the V-shaped gusset claw 300 having the linear first edge portions 301e and 302e as shown in FIGS. 4 and 5, while the pushing-in of the pointed tip portion P1 of the first pushing-in portion is local, since the flexibility of the side of the packaging material YA1' (the side surface SS as the package ZA1') becomes small, there has been a problem that forming defects such as wrinkles and insufficient folding occur, for example, on the inner side (valley side) of the gusset GA.

[0077] Therefore, when forming the gusset GA on the packaging material YA1' having the corner seal portions HE1 to HE4, the gusset claw 300' shown in FIG. 11 is adopted.

[0078] FIG. 11(A) is a view showing the gusset claw 300' and is a top view corresponding to FIG. 5(A). FIG. 11(B) is a view showing the relationship between the gusset claw 300' and the packaging material YA1' having the corner seal portions HE to HE4 and is a top view corresponding to FIG. 8(A).

[0079] In this example, it is the same as the gusset claw 300 shown in FIG. 5, except that the shape of the first pushing portion 301', particularly the shape of the first edges 301e1', 301e2', is different. The first edges 301e1', 301e2' of the first pushing portion 301' include a flat portion 310 and a curved portion 311. Specifically, the tip portion P1 of the first pushing portion is composed of a flat portion 310 that is substantially parallel to the conveying direction L, and an inclined region R0 that is continuous with one end thereof is composed of a curved portion 311 that is convex in the pushing direction P. "Convex in the pushing direction" means that when a straight line is connected from one end to the other end of the curved portion 311 (shown by a dashed-dotted line in FIG. 11(A)), it is curved so as to protrude in the pushing direction P more than the straight line.

[0080] By pushing with the flat portion 310, local pushing is dispersed as compared with the case of pushing with the sharp first pushing portion tip P1 as shown in FIG. 5. In addition, since the curved portion 311 sufficiently extends the valley side of the gusset GA, the occurrence of wrinkles and insufficient folding on the inner side (valley side) of the gusset GA, for example, can be avoided, and a good gusset GA can be formed.

[0081] The second pushing portion 302 is the same as in the case of the gusset claw 300 shown in FIG. 5. That is, also in this case, when a first virtual surface V1 including the two first edges 301e1', 301e2' in the first pushing portion 301' (in this case, the first virtual surface V1 is also a curved surface), the second pushing portion 302 (second end surface 302e) is configured such that the second edge 302e in front of the pushing direction P protrudes from the first virtual surface V1 toward the inner side of the packaging material YA1 (both in the conveying direction L and in the conveying width direction W).

[0082] Alternatively, as shown in FIG. 10(B), for the packaging material YA1', the second pushing portion 302 is configured such that the second edge 302e enters more toward the center of the conveying width direction W than the side surface SS of the packaging material YA1' (particularly, the side surface other than the gusset GA portion, for example, see also FIG. 2).

[0083] By doing so, the air near the gusset GA (indicated by the dashed circle in Fig. 10(B)) can be sufficiently led out to the outside of the packaging material YA1´ by the second pushing portion 302. As a result, the volume of the package ZA1´ can be minimized, and the positions of the articles XA1 in the package ZA1 can be aligned (position displacement can be prevented).

[0084] As described above, in this embodiment, the case where there are a plurality of articles XA1 in the package ZA1 has been exemplified, but the number of articles XA1 in the package ZA1 may be one.

[0085] In addition, as the article supply device 2, for example, various conveying devices such as a belt conveyor, a plate conveyor, and a roller conveyor can be applied.

[0086] Also, although the configuration in which the second pushing portion 302 is provided on both the upstream gusset claw 300A and the downstream gusset claw 300B of the gusset claw 300 has been exemplified, the second pushing portion 302 may be provided on only one of the upstream gusset claw 300A and the downstream gusset claw 300B.

[0087] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and technical idea thereof. That is, in the above-described embodiment, the positions, sizes, lengths, shapes, materials, orientations, etc. of each component can be appropriately changed.

Explanation of Reference Numerals

[0088] 1 Packaging machine 2 Article supply device 3 Packaging material supply device 4 Packaging machine main body 8 Unwinding shaft 14 Bag making device 15 Pinch roller 16 Center seal device 16a Bar sealer 16b Press roller 100 Top seal device 120 Sealer (first sealer) 160 Sealer (second sealer) 200 Gusset forming mechanism 210 Gusset unit 230 Moving mechanism (forward and backward mechanism) 232 Guide rail 234 Slider 236 Slide plate 236A Long hole 238 Motor 239 Rocking shaft 300 Gusset claw 300A Upstream gusset claw 300B Downstream gusset claw 300C Support member 301 First pressing part 302 Second pressing part 301E Edge 301e1, 301e2 First edge 302e Second edge 305 Support part 306 Extension member 310 Flat part 311 Curved part CE1 Center seal part CN Accommodation part GA Gusset HE1~HE4 Corner seal part L Conveying direction P Pressing direction P1 Tip of the first pressing part R0 Inclined area S Sealer SE Base end SS Side surface T Contact position TO1 Top seal part V1, V2 Virtual surface XA1 Article YA1 Packaging material ZA1 Package

Claims

1. A gusset forming mechanism for folding a packaging material to form a gusset when sealing a tubular packaging material containing an article in a first direction with a sealer, comprising: pushing means for pushing the side of the packaging material from the outside to the inside along a second direction intersecting the first direction; a moving mechanism for the pushing means; the pushing means comprising: a first pushing portion for pushing the packaging material near the sealer; and a second pushing portion for pushing the packaging material at a position closer to the article than the first pushing portion in the first direction, characterized in that it is a gusset forming mechanism.

2. The first pushing portion has two first edges that are open in a direction away from each other from the base end toward the first direction and at least a part of which abuts against a part of the packaging material; the second pushing portion has a second edge that extends along the first direction and at least a part of which abuts against a part of the packaging material; when a virtual plane including the two first edges in the first pushing portion is defined as a first virtual plane and a plane obtained by virtually expanding the first virtual plane in the tip direction of the first edge is defined as a second virtual plane, the second edge protrudes from the first virtual plane or the second virtual plane, characterized in that it is the gusset forming mechanism according to Claim 1.

3. The packaging material has a corner seal portion; the second pushing portion is provided such that its tip protrudes from the first virtual plane; each of the two first edges of the first pushing portion includes a curved portion that is convex in the pushing direction, characterized in that it is the gusset forming mechanism according to Claim 2.

4. A sealing device, characterized by comprising the gusset forming mechanism according to any one of Claims 1 to 3 and the sealer.

5. A packaging machine having the gusset forming mechanism according to any one of Claims 1 to 3.

6. A gusset forming method for folding a packaging material to form a gusset when sealing a tubular packaging material containing an article in a first direction with a sealer, comprising: a step of pushing the side of the packaging material from the outside to the inside by a first pushing portion along a second direction intersecting the first direction; and a step of pushing the side of the packaging material at a position closer to the article than the first pushing portion in the first direction by a second pushing portion along the second direction, wherein the second pushing portion pushes a part of the packaging material that has been folded by the first pushing portion to form a valley shape. ​ A gusset forming method characterized by the above.

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