JP5077896B2 - Folding device for corner cut carton - Google Patents

Description

  The present invention relates to a device for folding a flap of a corner cut carton.

  As a carton used for packaging a container, a corner cut carton having a shape in which four corners of a rectangular parallelepiped are obliquely chamfered is put into practical use. The chamfered portion of the corner cut carton cuts four corners of the bottom plate and top plate of the carton at an angle, and each of four flaps (sometimes called inner flaps) connected to both ends of the side plate of the carton. , It is formed by being folded in two stages along the cut portions of the top plate and the bottom plate. As a device for folding the flap of the corner cut carton, the flap located on the front side (downstream side) of the carton in the transport direction is folded with the guides on both sides of the transport path, while the flap located on the rear side (upstream side) in the transport direction is A device for folding with a cam roller or a fan-shaped tacker is known (see, for example, Patent Documents 1 and 2). In addition, Patent Documents 3 to 7 exist as prior art documents related to the present invention.

Japanese Patent No. 3780249 JP 2001-48123 A Japanese Utility Model Publication 7-38085 JP 2004-59027 A JP 2001-48117 A JP 2002-19772 A Japanese Patent No. 3586658

  In the conventional flap folding device, the shape of the cam roller or the tacker does not sufficiently correspond to the two-fold folding shape of the flap, and a relatively large error may occur in the folding shape of the flap. A first fold line is formed at the boundary with the side plate of the flap, and a second fold line is formed on the tip side of the first fold line. Therefore, if the flap is folded along the first fold line, the tacker tends to be pushed away from the flap and push only the tip side. Thereby, the flap is folded along the second fold line when the flap is not sufficiently folded along the first fold line, and as a result, the first fold may be insufficient. . In that case, there arises a problem that a gap is left between the cut portions at the four corners of the top plate and the bottom plate of the carton and the upper and lower edges of the corner surface formed by folding the flap.

  Then, an object of this invention is to provide the flap folding apparatus which can fold a flap reliably along the fold line of the 1st step | line.

According to the present invention, the flap (4) is pressed against the flap (4) on the rear side in the conveyance direction of the corner cut carton (1) conveyed by the conveyor (11) while being rotated forward in the conveyance direction, and the flap is folded. The flap folding device (20) includes an initial contact portion (28) positioned at a front end portion in a rotation direction when the flap is folded, and a rear end portion in the rotation direction on the outer periphery of the tacker. A late contact portion (29) positioned, and an intermediate contact portion (30) extending so as to draw a convex arc between the initial contact portion and the late contact portion. The curvature of the intermediate portion (30a) is set to be larger than the curvature of the regions (30b, 30c) before and after the rotation direction with respect to the intermediate portion, and the intermediate contact portion is connected to the first fold line ( 4a The second fold line can be contacted with the flap while suppressing the bending of the second fold line from the second fold line (4b) to beyond the second fold line to the tip side of the flap. As described above, the flap folding device of the corner cut carton in which the positional relationship between the tacker and the flap is set .

According to the flap folding apparatus of the present invention, the initial contact portion of the tacker is first brought into contact with the flap of the carton, and the bending force along the first fold line can be applied to the flap. Subsequently, the flap can be further folded while suppressing the return action due to the elastic restoring force of the flap by bringing the middle-term contact portion of the tacker into contact with the flap. Since the curvature of the middle part of the medium-term contact part is set larger than the curvature of the area before and after that, the medium-term contact part has a contour that the middle part bulges compared to the front and back areas. Thus, the medium-term contact portion can be protruded relatively large toward the flap. Therefore, after the flap is bent by the initial contact portion, the medium-term contact portion is brought into early contact with the flap from the vicinity of the first fold line, and the second fold line is attached to the flap at the intermediate contact portion. It is possible to continuously fold the flap along the first fold line by continuously contacting the middle contact portion with the flap from the second fold line to the front end side of the flap while restraining the fold. This makes it possible to reliably fold the flap along the first fold line. The second crease line can be folded in the process of sealing the opening at both ends of the carton after the packaged item such as a container is accommodated in the carton. In addition, the flap can be reliably folded along the first fold line while suppressing the bending along the second fold line of the flap at the middle contact portion.

  In the flap folding device of the present invention, the initial contact portion has a rounded shape, and the curvature (1 / Ra) of the initial contact portion is greater than the curvature (1 / Rc) of the region of the intermediate contact portion. It may be set larger. As a result, the flap is temporarily strongly pressed along with the contact between the initial contact portion and the flap, and the flap is folded along the first fold line due to the impact. Thereafter, the flap can be continuously folded along the first fold line by using the middle contact portion while suppressing the bending along the second fold line by the middle contact portion.

  In addition, in the above description, in order to make an understanding of this invention easy, the reference sign of the accompanying drawing was attached in parenthesis, but this invention is not limited to the form of illustration by it.

  As described above, in the flap folding device of the present invention, since the curvature of the intermediate portion of the middle-term contact portion of the tacker is set larger than the curvature of the region before and after the rotation direction, A contour that bulges in a hump compared with the front and rear regions is given, so that the medium-term contact portion can protrude relatively large toward the flap. Accordingly, the flap can be reliably folded along the first fold line while suppressing the bending along the second fold line of the flap at the middle contact portion.

The perspective view which shows an example of a corner cut carton. The perspective view which shows the form of the corner cut carton supplied to a caser. The fragmentary top view of the caser with which the flap folding apparatus which concerns on one form of this invention was integrated. The partial front view which looked at the caser of FIG. 3 from the arrow IV direction of the figure. The top view of the tacker provided in a flap folding apparatus. The figure which shows a mode that folding of an inner flap is started when a tacker contacts an inner flap. The figure which shows a mode that the tacker rotated further from the position of FIG. The figure which shows a mode that the tacker rotated further from the position of FIG. The figure which shows a mode that the tacker rotated further from the position of FIG. The figure which shows a mode that the tacker rotated further from the position of FIG. The figure which shows a mode that a tacker further rotated from the position of FIG. 10, and was separated from the inner flap.

  Hereinafter, an embodiment in which the present invention is applied to a folding process of a flap of a corner cut carton for can beverage packaging will be described. As shown in FIG. 1, a corner cut carton (hereinafter sometimes abbreviated as a carton) 1 includes a body 3 that accommodates a plurality (24 as an example) of canned beverages 2 in a state of being arranged vertically and horizontally. The inner flap 4 and the outer flap 5 are provided so as to be folded so as to close both ends of the body portion 3 and bonded to each other. FIG. 1 shows a state where the inner flap 4 is folded and the outer flap 5 is not yet folded. FIG. 2 shows a state in which one side plate 3c of the body portion 3 and the top plate 3b connected thereto are bent so as to stand upright with respect to the bottom plate 3a. As is apparent from these drawings, the body 3 includes a bottom plate 3a and a top plate 3b covering the bottom side and the top side of the can beverage 2, respectively, and a pair of plates disposed between the bottom plate 3a and the top plate 3b. And a side plate 3c. The inner flap 4 is connected to both ends of the side plate 3c, and the outer flap 5 is connected to both ends of the bottom plate 3a and the top plate 3b. The four corners of the bottom plate 3a and the top plate 3b are cut obliquely to form a chamfered portion 3d. Each inner flap 4 is folded in two along the chamfered portion 3d with two ruled lines (crease lines) 4a and 4b as bending axes. Therefore, by bonding the inner flap 4 and the outer flap 5, the carton 1 is configured as a packing container having a shape in which corner surfaces 6 are formed at four corners of a rectangular parallelepiped. The ruled line 4a located at the boundary with the side plate 3c corresponds to the first fold line, and the ruled line 4b located closer to the tip of the inner flap 4 than the ruled line 4a corresponds to the second fold line. Hereinafter, the ruled line 4a may be referred to as an A ruled line 4a, and the ruled line 4b may be referred to as a B ruled line 4b.

  The carton 1 folded up to the stage of FIG. 2 is supplied to the caser 10 shown in FIGS. The caser 10 is a device for supplying a predetermined number of canned beverages 2 onto the carton 1 in the middle of molding to complete the molding of the carton 1, thereby completing the package of the canned beverage 2. The flap folding apparatus of this embodiment is incorporated in the caser 10 and constitutes a part of the caser 10. The caser 10 has a conveyor 11 that conveys the carton 1 linearly. The cartons 1 in the state shown in FIG. 2 are sequentially carried into the conveyor 11 one by one from the left side in the drawing. In addition, the conveyance direction of the carton 1 is determined so that the side plate 3c on the side connected to the top plate 3b faces the front (downstream side) in the conveyance direction, as indicated by an arrow A in FIGS.

  The conveyor 11 includes a transport surface 12 on which the bottom plate 3 a of the carton 1 is placed, and a transport mechanism 13 that transports the carton 1 along the transport surface 12. As an example, the transport mechanism 13 attaches a plurality of hooks (not shown) to the chain 13a traveling along the transport direction so as to protrude from the transport surface 12 at a predetermined pitch in the transport direction. The carton 1 is transported by hooking the side plate 3c on the rear side in the transport direction. The transport mechanism 13 is provided with a chain drive mechanism 13b that travels the chain 13a and a side guide 14 that guides the carton 1 along one side edge (lower side edge in FIG. 3) of the transport surface 12. Yes. The side guide 14 is provided from the middle of the conveyance path by the conveyor 11. An inlet portion 14a that is curved so as to draw an arc toward the outer side in the width direction of the conveyor 11 (the direction crossing the conveying surface 12) is formed at the inlet side of the side guide 14, that is, the end portion on the upstream side in the conveying direction. . The introduction part 14a is provided to fold the inner flap 4 located in front of the carton 1 in the conveyance direction. That is, as the carton 1 is transported, the inner flap 4 at the front in the transport direction sequentially comes into contact with the introduction portion 14a from the base (that is, the side connected to the side plate 3c) and is taken into the side guide 14. Thereby, the inner flap 4 is folded along the A ruled line 4a.

  A flap folding device 20 is provided on the upstream side of the introduction unit 14a in the transport direction. The flap folding device 20 is provided to fold the inner flap 4 on the rear side (upstream side) of the carton 1 in the conveying direction. The flap folding device 20 includes a tacker 21 and a drive mechanism 22 that rotationally drives the tacker 21. The entire tacker 21 has a flat plate shape, and is provided as means for folding the inner flap 4 by contacting the inner flap 4 and pushing it forward in the conveying direction. The drive mechanism 22 rotationally drives the tacker 21 around the drive shaft 23 in the clockwise direction in FIG. The drive mechanism 22 is a constant in a horizontal plane centered on the drive shaft 23 of the arm 24, with the rotational motion transmitted from the chain drive mechanism 13 b of the transport mechanism 13 via the chain 22 a, the transmission shaft 22 b, the gear box 22 c and the like. The tacker 21 is driven by converting into a reciprocating rotational motion within the range. The tacker 21 is attached to the upper surface of the arm 24 so as to be integrally rotatable using a bolt 25. The reciprocating rotational motion of the tacker 21 is associated with the transporting motion of the conveyor 11 so that each time one carton 1 passes through the installation location of the flap folding device 20, the reciprocating rotational motion. In the following, when the tacker 21 rotates in the clockwise direction, in other words, the front and rear of the rotation direction are distinguished on the basis of the rotation direction when the tacker 21 contacts the inner flap 4.

  As is clear from FIG. 4, the tacker 21 is provided at a position higher than the conveying surface 12 so as to be in contact with the inner flap 4. As shown in FIG. 3, the rotation trajectory B on the outer periphery of the tacker 21 partially overlaps with the introduction portion 14 a of the side guide 14. Therefore, as shown in FIG. 4, the introduction portion 14 a of the side guide 14 is formed with a slit 14 b for allowing the tacker 21 to pass therethrough.

  As shown in FIG. 5, the tacker 21 includes a tacker body 26 and a handle portion 27 extending from the tacker body 26. The handle portion 27 is a portion overlapped with the arm 24 of the drive mechanism 22, and two elongated holes 27 a for passing the bolts 25 are formed therein. On the other hand, the tacker body 26 of the tacker 21 is provided as a portion that contacts and presses the inner flap 4. On the outer periphery of the tacker body 26, there are an initial contact portion 28 located at the front end in the rotational direction of the tacker 21, a late contact portion 29 located at the rear end in the rotational direction, an initial contact portion 28 and a late contact portion 29. And a medium-term contact portion 30 extending so as to draw a convexly bulging arc. The initial contact portion 28 and the late contact portion 29 have a shape in which both end portions of the tacker body 26 are rounded from the outer peripheral side of the tacker 21 to the inner peripheral side where the handle portion 27 exists. Each of the initial contact portion 28, the late contact portion 29, and the intermediate contact portion 30 is divided with positions P1 and P2 where the curvature changes as a boundary. The curvature of the initial contact portion 28 (the reciprocal of the curvature radius Ra) is set smaller than that of the late contact portion 29.

  The curvature of the medium-term contact portion 30 is different between the intermediate portion 30a, that is, the central portion in the rotational direction, and the regions 30b and 30c on both sides in the rotational direction. In other words, between the positions P3 to P4 where the curvature changes in the medium-term contact portion 30 is the intermediate portion 30a, between the positions P1 to P3 is the front region 30b, and between the positions P4 and P2 is the rear region 30c. The curvature of the intermediate portion 30a of the medium-term contact portion 30 is set to be larger than that of the regions 30b and 30c. As a result, the middle contact portion 30 is formed in a shape that draws a gentle arc with a smaller curvature from the intermediate portion 30a toward the contact portions 28 and 29 on both sides from the intermediate portion 30a. In other words, the medium-term contact portion 30 has a curved outline having a maximum portion 30a of curvature in the middle thereof. The curvature of each contact portion 30 may be appropriately set according to the size, rigidity, etc. of the inner flap 4 to be folded, but as an example, the curvature radius Ra of the initial contact portion 28 is set to the curvature radius Rb of the late contact portion 29. The radius of curvature Rc of the regions 30b and 30c of the medium-term contact portion 30 can be set to about five times that of the initial contact portion 28.

  Next, the operation of the flap folding device 20 will be described with reference to FIGS. As shown in FIG. 6, when the inner flap 4 forward in the transport direction is fed to the inside of the side guide 14 by the conveyor 11 of the caser 10, the initial contact portion 28 of the tacker 21 is moved to the inner flap 4 on the rear side in the transport direction. Rotate to contact position. Subsequently, as shown in FIG. 7, the tacker 21 is rotated in the clockwise direction (that is, forward in the conveying direction) so as to push in the inner flap 4 in synchronization with the conveyance of the carton 1 by the conveyor 11. 4 is folded along the A ruled line 4a (see FIG. 2). After that, as shown in FIG. 8, the region 30b on the front side in the rotational direction of the middle contact portion 30 contacts the inner flap 4, and the inner flap 4 is further folded around the A ruled line 4a.

  As the tacker 21 continues to rotate clockwise, the intermediate portion 30a of the middle contact portion 30 of the tacker 21 contacts the inner flap 4 between the A ruled line 4a and the B ruled line 4b of the inner flap 4, and the B ruled line 4b. The contact between the medium-term contact portion 30 and the inner flap 4 is continued until it reaches the tip side of the inner flap 4 beyond the B ruled line 4b. Thus, the contact between the inner flap 4 and the tacker 21 is continued while the B ruled line 4b is suppressed so as not to bend along the B ruled line 4b. The state at this time is shown in FIG. Thereby, a clearer crease is given to the inner flap 4 with the A ruled line 4a as an axis, and bending along the B ruled line 4b is prevented. Further rotation of the tacker 21 in the clockwise direction causes the region 30c on the rear side in the rotation direction of the middle-term contact portion 30 of the tacker 21 to continue to suppress bending along the B ruled line 4b of the inner flap 4 as shown in FIG. The region moves to the tip side of the ruled line 4b. Thereafter, the late contact portion 29 comes into contact with the inner flap 4. Thereby, the inner flap 4 can be smoothly introduced into the introduction portion 14 a of the side guide 14 while suppressing the return action due to the elastic restoring force of the inner flap 4. As shown in FIG. 11, when the tacker 21 rotates clockwise until it separates from the inner flap 4, the inner flap 4 on the rear side in the transport direction moves further to the downstream side in the transport direction than the introduction portion 14 a of the side guide 14. Fully captured. Thereafter, the inner flap 4 is transported while being held in a shape folded along the A ruled line 4a in the same manner as the inner flap 4 on the front side in the transport direction. When the carton 1 passes in front of the flap folding device 20, the tacker 21 is returned counterclockwise. When the next carton 1 is carried in, the tacker 21 is rotationally driven again in the clockwise direction, and the folding of the inner flap 4 is started from the state shown in FIG.

  In addition, in the area | region downstream of the conveyance direction rather than the part shown in FIG. 3 of the caser 10, the mechanism which sends the drink can 2 in the alignment state from the width direction opposite side (upper side of FIG. 3) of the conveyor 11 is provided. . After the beverage can 2 is fed by the mechanism, the inner flap 4 of the opening portion on the opposite side in the width direction of the carton 1 is A-ruled by the same mechanism as the side guide 14 and the flap folding device 20 shown in FIGS. It is folded along 4a. After the folding along the A ruled line 4 a of the inner flap 4 is completed, the outer flap 5 is folded and bonded to the inner flap 4. At this time, since the beverage can 2 is taken in on the carton 1, each inner flap 4 is folded not only along the A ruled line 4a but also along the B ruled line 4b by the pushing force through the outer flap 5. Thereby, the four corners of the carton 1 are correctly formed. Further, the top plate 3b is folded and bonded to the adhesive margin 3e of the side plate 3c on the rear side in the transport direction. Thereby, shaping | molding of the carton 1 is completed and the package of the drink can 2 is completed.

  As described above, according to the flap folding device 20 of this embodiment, the inner flap 4 is folded along the first ruled line 4 a by the initial contact portion 28 of the tacker 21, and then the inner contact portion 30 The inner flap 4 can be folded more strongly along the A ruled line 4a while suppressing the return due to the elastic restoring force of the flap 4. At that time, in particular, the medium-term contact portion 30 moves on the inner flap 4 toward the tip side while suppressing the B ruled line 4b from being bent. Therefore, the possibility that the inner flap 4 is bent along the B ruled line 4b during the folding by the tacker 21 can be eliminated. Therefore, the inner flap 4 can be sufficiently folded along the A ruled line 4a. Thereby, when the carton 1 is completed, the chamfered portions 3d of the bottom plate 3a and the top plate 3b and the chamfered portions 3d of the inner flap 4 can be aligned with no gap, thereby improving the shape accuracy of the corners of the carton 1.

  Incidentally, as shown by an imaginary line in FIG. 5, when the middle-term contact portion 30 is formed in a gentle curved shape with a uniform curvature, the tacker is more A than the B ruled line 4 b during folding of the inner flap 4. The folds along the B ruled line 4b are easily imparted by the folding force acting only on the tip side of the inner flap 4 from the B ruled line 4b. In that case, the crease along the A ruled line 4a becomes insufficient, the area around the A ruled line 4a swells, and there is a possibility that inconvenience may occur such that a gap is generated between the inner flap 4 and the chamfered portion 3d. is there. According to the tacker 21 of the present embodiment, the middle part 30a of the medium-term contact part 30 suppresses the B ruled line 4b from being bent, and the medium-term contact part 30 passes before and after the B ruled line 4b. It is possible to give a sufficient crease along the ruled line 4a.

  In order to bring the tacker 21 into contact with the inner flap 4 as described above, for example, the mounting position in the rotation direction of the arm 24 with respect to the drive shaft 23 and the distance from the rotation center of the drive shaft 23 to the outer periphery of the tacker 21. May be adjusted by the bolt 25 and the long hole 27a.

  The present invention is not limited to the above-described form, and various modifications can be made. For example, in the above embodiment, the tacker 21 is reciprocally rotated. However, the tacker 21 may be driven so as to return to the original position after making a round in the clockwise direction. The drive of the tacker 21 is not limited to an example in which power is transmitted from the conveyor 11 as long as it is synchronized with the conveyance of the carton 1 by the conveyor 11. For example, the tacker 21 is rotationally driven in synchronization with the conveyor 11 by an electric motor. Also good. In the present invention, the initial contact portion and the late contact portion are not necessarily limited to a shape rounded with a constant curvature, but can be modified such as a polygonal shape or a linear shape. In the above embodiment, the inner flap 4 is folded using one tacker 21. However, the inner flap 4 may be folded by arranging two or more tackers 21 side by side and rotating them synchronously. . By using the plurality of tackers 21, it is possible to easily cope with an increase in the height dimension of the inner flap 4.

DESCRIPTION OF SYMBOLS 1 Carton 2 Beverage cans 3 Carton trunk 3a Carton bottom plate 3b Carton top plate 3c Carton side plate 3d Chamfer chamfer 4 Inner flap 4a A ruled line (first fold line)
4b B ruled line (second crease line)
5 outer flap 6 corner surface 10 caser 11 conveyor 12 transport surface 13 transport mechanism 14 side guide 14a introduction part 20 flap folding device 21 tacker 26 tacker body 27 handle part 29 late contact part 30 middle stage contact part 30a intermediate part 30b front side of intermediate part Area 30c Rear area in the middle

Claims (2)

A flap folding device that folds the flap by pressing against the flap on the rear side in the conveyance direction of the corner cut carton conveyed by the conveyor while rotating the tacker forward in the conveyance direction,
On the outer periphery of the tacker, an initial contact portion located at a front end portion in the rotation direction when folding the flap, a late contact portion located at a rear end portion in the rotation direction, the initial contact portion, and the A middle-term contact portion extending so as to draw a convexly bulging arc with the latter-stage contact portion;
The curvature of the intermediate portion of the middle contact portion is set to be larger than the curvature of the region before and after the rotation direction than the intermediate portion ,
The second stage fold line extends from between the first fold line and the second fold line of the flap to the tip side of the flap beyond the second fold line. A flap folding device for a corner cut carton in which a positional relationship between the tacker and the flap is set so that the flap can be brought into contact with the flap while suppressing bending to a line .   The flap folding device according to claim 1, wherein the initial contact portion has a rounded shape, and the curvature of the initial contact portion is set larger than the curvature of the region of the medium-term contact portion.

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