JP2000025130A - Bag making machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely realize the turning-down of a front side tucking-in flap at the making of a bag having a small gore dimension by a method wherein a scoring plate for scoring a bottom return line and another scoring plate for scoring a bottom return line are acted on the sides different from each other or the front and rear sides of a paper cylinder. SOLUTION: A bottom folding scoring device 620 has a scoring blade 621A for scoring a bottom return line L4 by pressing the portion near the bottom of a bag of a paper cylinder T from above and a scoring blade 621B for scoring the bottom return line L5 by pressing the fore side of the bottom return line L4 from below. When the two parallel scores of the bottom return line L4 and the bottom tucking-in line L5 are scored on the paper cylinder T by rotating a lower rotation shaft 624 and an upper rotation shaft 622, the bottom return line L4 is under the state projected toward an underside and the bottom tucking-in line L5 is under the state projected toward a topside. When the paper cylinder T is developed in one plane by folding back the paper cylinder T at the bottom return line L4, a fore bottom tucking-in line is under the state projected toward the underside or the folding of the fore side tucking-in flap is performed by the valley folding in the direction of easy movement. Accordingly, the setting of a folding-back position can be performed precisely at the tucking-in of the fore side tucking-in flap inside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bag making machine for continuously forming paper bags such as shopping bags.

[0002]

2. Description of the Related Art As paper bags for shopping bags and the like,
For example, a square bottom paper bag is used. In this type of square bottom paper bag making machine, one bag paper P cut in advance to a predetermined size is sequentially and intermittently conveyed. 10
As shown in (a) and (b), both sides are folded into an M shape and folded in two, and the outer edge is glued to form a paper cylinder T that is open front and rear. Then, FIG.
As shown in FIGS. 0 (c) to (e), a bottom folded line L4 and a bottom folded line L5 are engraved on the paper cylinder T in parallel, and the bottom of the paper cylinder T is bent at the bottom folded drum. Back side flap T of T
1, while the paper cylinder T is rotationally transported with the rotation of the bottom folding drum, and only the front side folding flap T2 is turned upside down from the bottom folding line L4 to turn the front and back flaps T1,
T2 is developed in a plane along the outer periphery of the bottom folding drum, glued to the front and back flaps T1 and T2, and the front and back folding flaps T1 and T2 are folded inward to form the bottom portion B1 of the bottom of the paper bag B. To form a paper bag.

[0003] In such a bag making machine, when forming a square bottom portion of a paper bag T, as shown in FIG.
After the bottom turn-back line L4 and the bottom fold line L5 are engraved on the paper cylinder T in parallel by rotation of the upper rotation shaft K3 having the following and the receiving roller K4 having a rubber lining on the surface, the paper cylinder T
Is opened from the bottom return line L4, and the bag bottom is opened as shown in FIG.
As shown in the figure, the front side folding flap T2 is connected to the bottom folding line L5.
From B, the back side folding flap T1 was folded inward from the back bottom folding line L5A, respectively, and attached. At this time, the bottom return line L4 and the bottom insertion line L5 are connected as shown in FIG.
It is engraved in the paper cylinder T in the same direction as a concave state, and when it is folded back from the bottom folded line L4, as shown in FIG. 13, the back bottom folded line L5A is turned forward when the back folded flap T1 is folded. It is a valley fold in the direction, and the outer bottom fold line L5B
Is a mountain fold in the opposite direction when the front side folding flap T2 is folded.

[0004] When the back side folding flap T1 is folded from the back bottom folding line L5A, the front and rear sides of the back bottom folding line L5A are held over the entire length of the bag by a device called a front jaw. From the fold line L5B to the front side flap T2
When the front side folding line L5B is folded, the front side folding flap T2 is raised from the space between the paper tube T at both ends of the front bottom folding line L5B, and then folded back to the back side of the portion of the paper bag B where the bottom folding line L5B abuts. They had created so-called straight paper bags with no lines.

[0005]

However, when a front side folding flap T2 is folded inward from the bottom folding line L5B in a bag making machine for producing a straight paper bag, only the both ends of the bottom folding line L5B are used. In order to fold, the outsole folding line L5
There is a problem that the intermediate position of B rises, and the front-side folding flap T2 may not be folded along the bottom folding line L5B. Further, as shown in FIG. 13, since the front bottom folding line L5B is folded in the opposite direction when the front folding flap T2 is folded, when the front folding flap T2 is raised, the folding position is changed. Outer bottom folding line L5B
There is a problem that it is difficult to set along. Further, when the gore size of the paper bag B to be manufactured is small, for example, when the gore size is 70 mm or less, the length of the front-side folded flap T2 is about 50 mm or less. The distance between the fold flap T2 and the front fold flap T2 is further reduced.
B becomes difficult to fold, and the folding position along the outsole folding line L5B cannot be set accurately. In addition, the problem of setting the folding position along the outsole folding line L5B is that when the quality of the paper used is difficult to fold, especially when the thickness and hardness are insufficient, the accuracy may be further increased. was there.

Further, in a bag making machine for producing a straight paper bag, a surface of a receiving roller K4 corresponding to blades K1 and K2 for engraving a bottom folded line L4 and a bottom folded line L5 in a paper cylinder T is provided. , With rubber lining. Since the rotation of the upper rotation shaft K3 and the rotation of the receiving roller K4 are synchronized, the rubber lining has blades K1, K2
, But only this portion is severely deteriorated. But,
Since the rubber lining is integrally attached over the entire circumference of the receiving roller K4, it is not possible to replace only the deteriorated portion of the rubber lining, and there is a problem that it takes a long working time for replacement. Also, blades K1,
The distance between K2 needs to be set according to the gore size of the paper bag B to be manufactured, but this is manually performed by an operator, and there is a problem that the working efficiency is poor.

The present invention has been made in view of the above circumstances, and aims to achieve the following objects. An object of the present invention is to provide a bag making machine for a square-bottomed bag capable of reliably folding back a front side folding flap in correspondence with the production of a paper bag having a small gore. Improve work efficiency in maintenance. To improve workability in setting the positions of the bottom return line and the bottom insertion line.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a paper cylinder having an M-shaped folded portion is formed by folding bag paper for a paper bag into two folds and bonding together, and folding both sides inward. The bottom folding line and the bottom folding line of the folding flap are engraved on the front and back of the paper cylinder parallel to the bag bottom of the paper cylinder, and the front folding flap is turned upside down from the bottom folding line, and In a bag making machine for a square-bottom bag, the front-side folding flap and the back-side folding flap are overlapped with each other, and the front and back folding flaps are folded inward from the bottom folding line to form a square bottom portion of the paper bag. A pair of creased blades and a receiving portion for engraving the bottom folded line by sandwiching a tube from the front and back, and a pair of creased blades and a receiving portion for engraving the bottom folded line by sandwiching the paper cylinder from the front and back Having these two creased blades, It has solved the above problems by having a contact with the bottom folding knurling device in the paper tube from the front and back different sides of the tube. In the present invention, a hard receiving portion is provided corresponding to the scoring blade for engraving the bottom folded line, the bottom folded line is engraved only on the front side of the paper cylinder, and the bottom folded line is engraved. Means is provided in which a concave groove is provided as a receiving portion corresponding to the scoring blade to be provided, and the bottom folding line is carved on the front and back of the paper cylinder.
Further, a soft receiving member can be attached to the concave groove. Further, the scoring blade may be folded inward on both sides to have an M-shaped folded portion, and the central portion thereof may be higher than both end portions in correspondence with the thickness of the paper cylinder. The present invention provides a gore size setting device in which the scoring blade for engraving the bottom return line and the receiving portion for engraving the bottom return line are attached to the same rotating shaft and set a circumferential position thereof. Is preferably provided. Further, a scoring blade for engraving the bottom folding line is attached to the rotating shaft, and a receiving portion corresponding to the scoring blade for engraving the bottom folding line,
It can be mounted as a hard lining on the surface of the receiving roller around the rotation shaft. Further, the hard lining may be provided in a plurality of parts around the receiving roller in the circumferential direction.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a bag making machine and a bag making method according to the present invention will be described below with reference to the drawings. 1 to 9, reference symbol M denotes a bag making machine, P denotes bag paper, T denotes a paper cylinder, B denotes a paper bag, H denotes a handle, 1 denotes a paper feeder,
2 is a handle device, 3 is a creasing device, 4 and 5 are paper tube forming devices,
6 is a bag bottom forming device, and 7 is a press device.

[0010] As shown in FIG.
, A gripper device 2 that forms a handle H and affixes the handle H to the bag paper P, and an outer edge portion and a substantially central portion of the bag paper P supplied from the paper feed device 1. Folding part P1
Fold line L1, fold line L2, and fold line L3 for forming
Device 3, which conveys the bag paper P from the creasing device 3 to the bottom forming device 6, and folds the folding line L1 and the folding line L2 formed by the creasing device 3. Paper tube forming devices 4 and 5 for forming a paper tube T by folding and pasting bag paper P in two along the tatami line L3, and a bag bottom forming device 6 for forming a square bottom portion B1 of the paper bag B. And a press device 7 for pressing the paper bag B having the square bottom portion formed thereon and sending it out to a product table, and counting the number of manufactured paper bags B.

The paper feeder 1 is positioned at the uppermost stream of the bag making machine M, and continuously supplies bag paper (sheets) P for paper bags cut into a predetermined size in advance at intervals. It is said.

As shown in FIGS. 6 (a) and 6 (b), for example, the gripping device 2 includes a sticking paper H1 and a string-like gripping portion H2.
Are integrally formed to form a handle H, and the handle H is affixed to, for example, two predetermined positions of the bag paper P. At this time, a substantially J-shaped portion is formed at the folded portion P4 on the rear side in the transport direction of the bag paper P. And a cut in the shape of a substantially inverted J-shape, cut the cut portion K from the end to be the folded portion P2 of the folded portion P4, attach the handle H, and then fold the folded portion P4 back. The sheet H to be stuck is sandwiched and stuck together to form a bag mouth portion of the paper bag B.

As shown in FIG. 1, the creasing device 3 is located downstream of the handle device 2 and sandwiches the bag paper P to form a folding portion P1.
Fold line L1, fold line L2, fold line L3 for forming
And a plurality of creased rollers formed with creased grooves corresponding to the creased convex rollers, and a plurality of creased rollers. A position setting unit (not shown) for setting the position to a predetermined position.

As shown in FIG. 1, the paper tube forming devices 4 and 5 are located downstream of the creasing device 3 and are folded by being sandwiched between a folding line L1 and a folding line L2 by a roller conveyor connected in series. FIGS. 7C to 7E show a first folding section and a folding section (second folding section) that folds the bag paper P in two along the folding line L3. Thus, the paper cylinder T is formed.

As shown in FIGS. 1 and 2, the bag bottom forming device 6 includes a supply device 60A for continuously supplying, for example, a formed paper cylinder T at intervals, and a supply device 60A at the end of the supply device 60A. A folding crease device 610 to be disposed; a bottom creasing device 620 for forming a crease between the bottom folding line L4 and the bottom folding line L5 near the bottom of the bag, which is a corner portion of the paper bag B; A bottom folding drum 640 for rotatingly transferring the cylinder T;
And a bottom opening device 630 that is disposed close to the outer periphery of the paper cylinder T and opens the bag bottom by adsorbing the bag bottom side of the paper cylinder T, and the bottom folding device that is disposed close to the outer periphery of the bottom folding drum 640. A flap folding device 650 that folds the front-side folded flap T2 from the bottom folded line L4 formed by the bottom 620 to the inside of the paper tube T, and unfolds the front and back folded flaps T1 and T2 in a plane along the bottom folding drum 640; A gluing device 660 for gluing the front and back folding flaps T1 and T2, a flap rising device 670 for raising the front and back folding flaps T1 and T2, and a bag bottom folding for attaching the folding flaps T1 and T2. Device 680.

As shown in FIG. 2, the supply device 60A comprises, for example, a pair of right and left endless conveyor chains provided between a driving sprocket and a driven subrocket, and attached to the conveyor chain. The paper tube T is conveyed to the creasing bottom folding and sticking step of the next step with the bag bottom side directed in the conveying direction by the feed claw.

As shown in FIG. 2, the folding crease device 610 includes, for example, an upper rotating shaft 612 having a single flat creasing blade 611 and a roller for receiving the creasing blade 611. A lower rotation shaft 614 provided with a 613,
The creasing blade 611 is screwed to a pair of mounting plates fixed to the upper rotating shaft 612, and the lower rotating shaft 6
One of the sides 14 is connected to a drive source to rotate and drive the lower rotating shaft, and to transmit the rotation to the upper rotating shaft 612 to rotate the upper rotating shaft 612 in the opposite direction to the lower rotating shaft 614. Paper cylinder T sent from paper cylinder supply device 60A
The creasing blade 611 is pressed against the bottom of the bag to make a fold at the time of folding.

The bottom creasing device 620 is shown in FIGS.
As shown in the figure, the upper rotating shaft 622 and the upper rotating shaft 6
22, a creasing blade 621 </ b> A which presses the bottom of the bag, which is on the front side in the transport direction of the paper cylinder T, from the upper side to engrave the bottom return line L <b> 4, a lower rotating shaft 624, A creasing blade 621B provided on the rotating shaft 624 for pressing the front side of the bottom return line L4 of the paper cylinder T from below to cut a bottom fold line L5 parallel to the bottom return line L4; A receiving roller 62 provided on the lower rotating shaft 624 and having a hard lining on its surface to be a receiving portion of the creasing blade 621A.
3, a receiving portion 621C provided on the upper rotary shaft 622 and having a concave groove 621c for pressing the paper cylinder T corresponding to the creasing blade 621B, a creasing blade 621A and the receiving portion 6
And a gore size setting device 626 for setting a circumferential position with respect to the upper rotation shaft 622 with respect to the upper rotation shaft 21C. The groove 621
As shown in FIG. 3, a plurality of hard linings of hard rubber or resin of the receiving roller 623 for mounting a soft receiving member made of rubber or soft urethane, for example, as shown in FIG. ), And when worn out, the pasting position can be exchanged. Further, each of the creased blades 621A and 621B is folded inward on both sides to form M
Corresponding to the thickness of the paper tube T having the letter-shaped folded portion, the vicinity of the center is set higher than both end portions, so that both sides of the thick paper tube T are not damaged, and The crease can be reliably engraved near the center.

The creasing blade 621A and the receiving portion 6
21C is a pair of mounting plates 627A, 627A, 627B, 6 having a notch 625 fixed to the upper rotation shaft 622.
27B, and these mounting plates 627A, 6
27B is attached to the upper rotation shaft 622 so as to be rotatable with respect to each other, and one side of the lower rotation shaft 624 is connected to a driving source via a driving gear 624A to rotate and drive the lower rotation shaft. Rotate the drive gear 622
A is transmitted to the upper rotation shaft 622 via A, the upper rotation shaft 622 is rotated in the opposite direction to the lower rotation shaft 624, and the line is moved toward the bottom of the bag of the paper cylinder T sent from the folding crease device 610. The creasing blade 621A and the creasing blade 621B are pressed against each other to form a fold at the time of folding.

The mounting plates 627B and 627B are integrally connected by a position setting rod 628B parallel to the upper rotation shaft 622, and the mounting plates 627A and 627A are positioned so as to pass through the elongated holes 627C of the mounting plates 627B and 627B. They are integrally connected by a position setting bar 628A parallel to the setting bar 628B. These position setting bars 628A and 628B
The upper rotating shaft 6 is screwed by the position setting screw 628C.
A circumferential position around 22 is set. These mounting plates 627A, 627B, position setting rods 628A, 628B,
The position setting screw 628C constitutes a gore size setting device 626.

The bottom opening device 630 includes, as shown in FIG.
For example, a rotating arc plate 632 fixed to the upper rotating shaft 631
And a bottom opening flange 633 located on both outer sides of the rotating arc plate 632 and fixed to the upper rotating shaft 631, and a rotating arc plate 632 facing an opening formed by cutting out the outer peripheral surface of the rotating arc plate 632. , A lower rotating shaft 636 paired up and down with the upper rotating shaft 631 of the rotating arc plate 632, and a bottom folding drum 64 as described later.
The bottom opening flange 63 corresponding to the opening / closing claw
3 and an opening / closing claw respectively disposed on the front side folding flap T2 at the time of opening the paper cylinder T from the bag mouth serving as the bag bottom to set the inner folding line B2 at the bottom. A kick plate.

The suction pad of the bottom opening device 630 is connected to a negative pressure generating device such as a vacuum pump to suck the front folding flap T2 of the paper cylinder T and rotate the rotary arc plate 632 and the suction pad. The front side flap T2 of the paper tube T is sucked along the locus. At about the same time, the catch claw 641 provided on the bottom folding drum 640 disposed close to the bottom opening device 630 captures the tip of the back side flap T1 of the paper cylinder T with the bag bottom opened, and
As shown in FIG. 4, the rear position of the bottom folding line L5 of the paper cylinder T is captured from the folding portions T3 on both sides by the respective opening and closing claws,
By rotating the upper rotation shaft 631 and the bottom folding drum 640 in mutually opposite directions, the bag bottom of the paper tube T is opened.

As shown in FIGS. 2 and 4, the flap folding device 650 includes a pair of left and right guide plates 651 disposed above the bottom folding drum 640, for example.
The guide plate 651 and the linear member 652 are fixed to a mounting rod 653 via a mounting arm 654. And each guide plate 6
51 and the linear member 652 guide the paper tube T rotated and conveyed by the bottom folding drum 640 between each guide plate 651 and the bottom folding drum 640, and the front folding flap sucked by the bottom opening device 630. By pressing T2 against each guide plate 651 and the linear member 652, the front-side folded flap T2 is folded back from the bottom folded line L4, that is, the front and back folded flaps T1 and T2 are formed on the outer periphery of the bottom folded drum 640. The paper tube T is unfolded along the plane and is stably conveyed through a slight gap between the guide plate 651 and the bottom folding drum 640 while suppressing the rise of the paper cylinder T. At the front position of the flap folding device 650, as shown in FIGS. 2 and 4, a press roller 659 is arranged in contact with the outer peripheral surface of the bottom folding drum 640.

As shown in FIG. 2, the gluing device 660 is disposed on the outer periphery of the bottom folding drum 640 and in front of the press roller 659. As shown in FIG. And a glue roller having a glue pad made of synthetic rubber or the like on the outer peripheral surface, and the adhesive in the tank is applied to the glue pad of the glue port via a relay roller. The adhesive is adhered and glued to the front and back folded flaps T1 by rotation of a gluing roller.

The bottom folding drum 640 is shown in FIGS.
As shown in FIG. 5, for example, it is composed of an aggregate of a plurality of divided drums 640B fixed at appropriate intervals to a mounting cylinder fixed to the rotating shaft 640A. It is assumed that. Each of the divided drums 640B has a catch claw 6 that is disposed on the outer periphery of the bottom folding drum 640 and that sandwiches the tip of the back side folding flap T1 of the paper cylinder T.
41, front holding claws 642 and 642A for engaging the front and rear positions of the bottom folding line L4 of the back side folding flap T1, and opening and closing claws for holding the paper cylinder T from the folding portion T3 corresponding to the opening and closing claws of the bottom opening device 630. , A rear holding pawl 644 and a rear raising pawl 645 located near the bottom return line L4 of the front side folding flap T2.
And a plurality of suction ports for sucking the back side folding flap T1. As shown in FIG. 4, the catching claw 641 is located at a central portion in the axial direction of the bottom folding drum 640, and its tip portion extends from the groove to the outer periphery of the divided drum 640 </ b> B. The back side folding flap T1 is held between the portion and the divided drum 640B. On the other hand, as shown in FIG. 6, the front holding claws 642 and 642A hold the front and rear sides of the bottom folding line L5 of the back folding flap T1 by opening and closing the movable claws 642.

Also, on both sides of the bottom folding drum 640,
As shown in FIG. 4, for example, a rear pressing claw 644 that presses the front side of the bottom fold line L5 of the front side fold flap T2 from above the front side fold flap T2 and a rear position of the bottom fold line L5 of the front side fold flap T2. Front side folding flap T2
And a raised pawl 645 located between the paper cylinder T and the front surface paper of the paper cylinder T. Back holding claw 644 and back raising claw 6
Reference numeral 45 denotes a pair arranged in the width direction of the divided drum 640B so as to reciprocate the bottom folding drum 640 in the rotation axis direction.

As shown in FIGS. 2 and 5, the flap rising device 670 includes a rotary shaft 67 having two flat push blades 671, 671 in front of the bottom folding drum 640.
2, the rotating shaft 672 is driven in synchronization with the driving of the bottom folding drum 640, and the rotation of the rotating shaft 672 causes the front and back folding of the paper tube T conveyed by the bottom folding drum 640. The pushing blades 671, 671 are pressed against each other along the bottom folding line L5 of the flaps T1, T2, and the front holding claws 642, 64 holding the vicinity of the bottom folding line L5 in an open state.
It is guided between 2A and between the back presser nail 644 and the rear raise nail 645. Then, the front holding claws 642 are closed, and the front folding flaps T1 in a state where the front folding flaps T1 pressed by the rear pressing claws 644 are raised by engaging the front and rear sides of the bottom folding line L5 of the rear folding flaps T1. Raised when the claw 645 moves upward, the front and back folding flaps T1 and T2 are raised and brought into a state where the folding can be performed by the bag bottom folding device 680.

As shown in FIG. 2, the bag bottom folding device 680 folds the front and back folding flaps T1 and T2 raised by the flap rising device 670 or the like into the inside. A bottom folding rod that is rotatably provided horizontally in synchronization with the rotation of the drum 640;
0 and a bottom folded plate provided with a slight gap,
The front folding flap T2 is folded inward by the bottom folding bar, and the back folding flap T1 is folded inward by the bottom folding plate.

As shown in FIG. 2, the rotary transport drum 690 is provided below the bottom folding drum 640, and has two endless belts spanning the rotary transport drum 690 and a plurality of guide rollers 691. The front and back folding flaps T1 and T2, which have insides 692 and 693 and are folded inward by the bag bottom folding device 680, are transferred to the supply position of the press device 7 in the next process, and the front and back folding flaps glued in the previous process are provided. Attach T1 and T2.

As shown in FIG. 1, the press device 7 includes front and back folding flaps T1, T2 by a bag bottom folding device 680.
The drum 71 for transporting the folded paper cylinder T and the folded front and back flaps T1 and T2 are pressed to form a paper bag B.
, A press roller 72 for forming the square bottom portion B1, a counting device for counting the formed paper bags B, and a product table 73 for arranging the paper bags B.

Hereinafter, the manufacture of a paper bag in the bag making machine M configured as described above will be described.

First, bag paper P cut in advance to a predetermined size
Are continuously supplied at intervals by the paper feeding device 1, and the sticking paper H 1 and the string-shaped grip portion H 2 are
6A, a substantially J-shaped and substantially inverted J-shaped cut is made at the rear side in the transport direction of the bag paper P, as shown by (b) in FIG. Cut the cut portion K from the end portion of the portion P4 that becomes the folded portion P2,
After gluing, as shown in FIG.
As shown by (c) in FIG. 6 (b), the handle H is pasted,
As shown by (e) in FIG. 6 (b), the handle H is glued to the pasting paper H1, and as shown by (d) in FIG. 6 (b), the rear end of the bag paper P is folded back. Sandwiching the sticking paper H1 of the handle H to form a bag mouth portion of the paper bag B;
As shown in FIGS. 7C and 7D, two sets of fold lines L1 and return lines L2 are formed on the bag paper P by the creased convex roller 31 and the creased concave roller 32 of the crease device 3. The folding line L3 is engraved.

Next, as shown by (g) and (h) in FIG.
The bag paper P is sandwiched between the folding line L1 and the folding line L2 and folded, and as shown in FIGS. 7D and 7N, the bag is folded along the folding line L3 by the second folding process unit. The sheet P is folded in two and the glue margin P3 is attached to form a paper cylinder T.

Here, in the bottom crease device 620 of the bag bottom forming device 6, the lower rotary shaft 624 and the upper rotary shaft 622 are driven to rotate, and as shown in FIGS. Tube T
Each of the creasing blades 621A and 621B is pressed against the bag bottom on the front side in the conveyance direction to form two parallel creases of the bottom return line L4 and the bottom fold line L5 at the time of bottom folding.
At this time, as shown in FIGS.
Since the crimping blade 621B comes in contact with the crimping blade 621B from the lower side of the paper cylinder T, the bottom folded line L4 is convex downward as shown in FIG. When it is opened, the valley is folded in the forward direction, and the bottom fold line L5 is in an upwardly convex state. Also, in the figure, the convex state of the bottom return line L4 is emphasized for clarifying the direction in which the crease is formed, but the creasing blade 621A is located between the hard lining of the receiving roller 623. The paper cylinder T which does not need to be creased because the bottom folded line L4 is carved with the paper cylinder T interposed therebetween
There is no streak trace on the lower side, and a bottom fold line can be carved only on the back side of the paper tube T. Further, in the scribing blades 621A and 621B, the central portion is set higher than both end portions in correspondence with the thickness of the paper cylinder T having both sides thereof folded inward and having an M-shaped folded portion. Therefore, it is possible not to damage both sides of the thick paper tube T, and it is possible to reliably form a crease near the center of the thin paper tube T.

Thereafter, the paper tube T containing the bottom return line L4 and the bottom return line L5 is transferred to the bottom opening device 630, and the bag bottom of the paper tube T is opened along the rotation path of the suction pad. At this time, the catching claw 64 provided on the bottom folding drum 640 which is disposed close to the bottom opening device 630 while nipping the folded portion T3 of the paper cylinder T by the opening / closing claws of the bottom opening device 630 and the bottom folding drum 640.
1 holds the front end of the paper cylinder T with the bag bottom open on the back paper side, that is, the back side folded flap T1.

On the other hand, the back holding claw 644 and the back-raising claw 64
5, the rear holding claw 644 and the rear raising claw 645 are in contact with the bottom folding drum 640 and are located on both outer sides of the paper cylinder T held down by the capturing claw 641 until the paper cylinder T is nipped by the capturing claw 641. It is kept in a state. Then, as shown in FIG. 4, the rear-raised claw 645 is on the inner side,
1 and overhangs the paper cylinder T,
And the bottom folding line L of the front folding flap T2
5 and above the front surface paper of the paper cylinder T. At this time, the rear holding claw 644 is in a standby state in a state in which it comes into contact with the bottom folding drum 640 and is positioned outside the paper cylinder T suppressed by the catching claw 641.

In this state, the bag bottom of the paper tube T is opened by rotating the upper rotation shaft 631 and the bottom folding drum 640 in mutually opposite directions. The paper cylinder T having the open bottom of the bag has a bag bottom portion having a flap folding device 650 and a bottom folding drum 64.
0, only the front-side folded flap T2 is folded back to the front side paper of the paper tube T, and at the same time, the rear-raising claw 645 is moved to the front side paper of the paper cylinder T and the front side folded flap T2.
Between the front and back flaps T1,
The paper cylinder T is conveyed by the rotation of the bottom folding drum 640 in a state where T2 is developed in a plane along the outer periphery of the bottom folding drum 640. Next, the rear holding claw 644 that is in contact with the bottom folding drum 640 and stands by at a position outside the paper tube T held by the catching claws 641 is inside, that is, the paper tube T held by the catching claws 641. And comes into contact with the front side flap T2 of the paper tube T. Thereafter, the paper cylinder T is conveyed by the rotation of the bottom folding drum 640, and the gluing roller 662 is rotated, so that the front and back folding flaps are moved to the gluing position shown in FIG. Gluing of T1 and T2 is performed.

After the gluing step is completed, the rotating shafts 672 of the pushing blades 671 of the flap rising device 670 are rotated so that the front and back folding flaps T1, T1 of the paper tube T are rotated.
Each of the pushing blades 671 along the bottom folding line L5 of T2.
Bites into the back bottom flap T1 and the back bottom fold line L5A
The part is held between the front holding claws 642 and 642A holding the part in an open state, and thereafter, as shown in FIG.
The push-in blade 671 rotates the front-side folded flap T2 to raise the front bottom folded line L5B portion of the pawl 64.
5 and the rear holding claw 644 are guided toward the rear raising claw 645 side. Then, the catching claw 641 moves upward along the protruding portion formed by the rotating roller on the cam surface, separates from the back side folding flap T1 that has been gripped up to that time, and closes the front holding claw 642. While biting back and forth of the back bottom folding line L4A of the folding flap T1,
The opening / closing claw is separated from the folding part T3, while the back-raising claw 64
5 rotates upward, whereby the front side of the front bottom folding line L5B in the front side folding flap T2 is pressed by the rear pressing claw 644, and the rear side of the front bottom folding line L5B is raised by the rear raising claw 645. increase. Then, the front and back folding flaps T1 and T2 are folded inward from the bottom folding lines L5A and L5B by the bag bottom folding device 680.

At this time, as shown in FIG. 9, the paper cylinder T folded back from the bottom folded line L4 and opened flatly has the back bottom folded line L5A protruding upward, that is, the back folded flap T1.
Is folded in the opposite direction when the fold is folded, but the outsole folding line L5B is convex downward, that is, the front folding flap T
2 is folded in the forward direction when folding. Accordingly, when the front side folding flap T2 is folded inward from the bottom sole folding line L5B, it is only necessary to raise the front bottom folding line L5B from both ends of the valley-folding bottom sole folding line L5B with the rearwardly raised claws 645, so that the center of the bottom sole folding line L5B can be folded. It is possible to accurately set the turn-back position without the part being raised. Also,
Since the outer bottom folding line L5B is folded in the forward direction when the front folding flap T2 is folded, the folding can be easily performed even in the thick paper cylinder T where it is normally difficult to set the folding position. , Can further facilitate folding. Therefore, it is possible to avoid a step of making the paper cylinder T unnecessarily damaged. Also, the back bottom folding line L5A is formed into a mountain fold in the opposite direction when the back side folding flap T1 is folded. However, the back bottom folding line L5A is held over the entire length of the bag width by the front holding claws 642 and 642A. The folding position does not become inaccurate, for example, emerges in the middle position of the fold.

Then, the sheet is transported to the supply position of the press device 7 by the rotary transport drum 690, and the front and back folded flaps T1 and T2 that have been glued in the previous step are attached.

In the press device 7, the paper cylinder T in which the front and back folding flaps T1 and T2 have been folded by the bag bottom folding device 680 is transported by the drum 71, and in the middle of this transport, the front and back folded by the press roller 72. Press the fold flaps T1 and T2 and press the square bottom B of the paper bag B
1 is formed, and finally, the formed paper bag B is counted by the counting device.
Are arranged as shown in FIG.

[0042]

According to the bag making machine of the present invention, the following effects can be obtained. (1) When the front side folding flap is folded inward from the bottom folding line, a scoring blade for carving the bottom folding line and a scoring blade for carving the bottom folding line so as to form a forward valley fold. And
Since the paper cylinder comes in contact with the paper cylinder from different sides, it is possible to improve the accuracy of the setting of the folding position, so that the folding of the front folding flap is ensured in response to the production of paper bags with small gore dimensions. Can be provided. (2) When the hard receiving portion is formed as a plurality of hard linings around the receiving roller in the circumferential direction, each of the divided portions can be easily replaced when the hard lining deteriorates. In addition, work efficiency in maintenance can be improved. (3) A hard receiving portion is provided corresponding to the scoring blade for engraving the bottom return line, the bottom return line is engraved only on the surface side of the paper cylinder, and the bottom inversion line is engraved. By providing a concave groove equipped with a soft receiving member as a receiving portion corresponding to the scoring blade,
In the case where the bottom folding line is carved on the front and back of the paper cylinder, unnecessary creasing marks are not formed on the completed paper bag because the hardened receiving portion does not cause the creasing blade to bite into the paper cylinder. Since the engraving position can be set at the receiving portion as well, the certainty of the folding of the front side folding flap and the accuracy of the folding position setting can be improved. (4) A gore dimension setting device is provided in which a scoring blade for engraving the bottom turn-back line and the receiving portion for engraving the bottom turn-in line are mounted on the same rotating shaft, and set a circumferential position thereof. When provided, the gore dimension setting device makes it easy to set the position between the creased blade and the receiving portion, so that it is possible to improve workability in setting the positions of the bottom return line and the bottom return line. .

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one embodiment of a bag making machine and a bag making method according to the present invention.

FIG. 2 is a front view showing a bottom forming device in the bag making machine of FIG.

FIG. 3 is a perspective view showing a bottom creasing device in the bag bottom forming device of FIG. 2;

4 is a perspective view showing a state in which a bag opening of a paper cylinder is opened by a bottom opening device and a flap folding device in the bag bottom forming device of FIG. 2;

5 is a front sectional view showing a bag bottom folding device, a front holding claw, a rear holding claw, and a rear raising claw in the bag bottom forming device of FIG. 2;

FIG. 6 is a perspective view showing cutting and gluing (a) for gripping on bag paper and sticking and folding back of the grip (b) in one embodiment of the bag making machine according to the present invention.

FIG. 7 shows a method (c) (d) for forming a paper cylinder from bag paper and a method (e) (f) (g) for forming a paper bag from a paper cylinder in an embodiment of the bag making machine according to the present invention. It is a perspective view.

FIG. 8 is a schematic cross-sectional view showing the engraving of a bottom folded line and a bottom folded line on a paper cylinder in an embodiment of the bag making machine according to the present invention.

FIG. 9 is a schematic cross-sectional view showing the state of the front bottom folding line and the back bottom folding line in the paper cylinder developed in one embodiment of the bag making machine according to the present invention.

FIG. 10 is a perspective view showing a conventional paper bag formation.

FIG. 11 is a front view showing a conventional bag making machine.

FIG. 12 is a schematic cross-sectional view showing a conventional folding of a bottom folded line and a bottom folded line in a paper cylinder.

FIG. 13 is a schematic cross-sectional view showing a state of a front bottom folding line and a back bottom folding line in a conventional developed paper cylinder.

[Explanation of symbols]

 M: bag making machine P: bag paper T: paper cylinder T1: back side folding flap T2: front side folding flap B ... paper bag H ... handle L4 ... bottom folded back line L5 ... bottom folding line, L5A ... back bottom folding line L5B ... front bottom Folding line 6 ... Bag bottom forming device 620 ... Bottom folding crease device 640 ... Bottom folding drum 641 ... Capturing claw 642,642A ... Front holding claw 644 ... Back holding claw 645 ... Back raising claw 670 ... Flap rising device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E075 BA48 BB23 CA01 CA10 DA03 DA04 DA05 DA14 DA15 DA32 DB02 DB22 DC26 DC28 DC33 DC43 DC44 DD09 DD33 DE06 GA02 GA03 GA04 GA05

Claims (7)

[Claims] 1. A paper bag for a paper bag is folded in two and bonded together, and both sides thereof are folded inward to form a paper cylinder having an M-shaped folded portion. The bottom fold line and the bottom fold line of the fold flap are engraved in parallel on the front and back of the paper cylinder, and the front fold flap is turned upside down from the bottom fold line, and the front fold flap and the back fold flap In a bag making machine for a square bottom bag that folds both front and back folding flaps inward from the bottom folding line so as to form a square bottom portion of the paper bag, the paper cylinder is sandwiched from the front and back. A pair of creased blades and receiving portions for engraving the bottom return line, and a pair of creased blades and receiving portions for engraving the bottom folding line by sandwiching the paper cylinder from the front and back; Creased blades from different sides of the paper cylinder A bag making machine, comprising: a bottom creasing device that comes into contact with the paper cylinder. 2. A hard receiving portion is provided corresponding to the scoring blade for engraving the bottom folded line, and the bottom folded line is engraved only on the front side of the paper cylinder, and the bottom folded line is engraved. 2. The bag making machine according to claim 1, wherein a concave groove is provided as a receiving portion corresponding to the scoring blade to be provided, and the bottom folding line is engraved on the front and back of the paper cylinder. 3. The bag making machine according to claim 2, wherein a soft receiving member is mounted in said concave groove. 4. The scoring blade is characterized in that both sides are folded inward and the center of the paper cylinder having an M-shaped folded part is higher than both ends in correspondence with the thickness of the paper cylinder. A bag making machine according to any one of claims 1 to 3. 5. A gore size setting for mounting a scoring blade for engraving the bottom folded line and the receiving portion for engraving the bottom folded line on the same rotating shaft and setting a circumferential position thereof. 5. The bag making machine according to claim 1, further comprising an apparatus. 6. A scoring blade for engraving the bottom folding line is attached to a rotating shaft, and a receiving portion corresponding to the scoring blade for engraving the bottom folding line has a receiving roller surface around the rotating shaft. The bag making machine according to any one of claims 1 to 5, which is attached as a hard lining. 7. The bag making machine according to claim 6, wherein the hard lining is provided in a plurality of parts around the receiving roller in a circumferential direction.