Flap deployment device in angular bottom forming device of bag-making machine, angular bottom forming device in bag-making machine, and bag-making machine

Abstract

Provided are a flap deployment device in an angular bottom forming device of a bag-making machine, an angular bottom forming device in a bag-making machine, and a bag-making machine, which make it possible to ensure worker safety, and to adjust at least a pair of guide plates of the flap deployment device even during ongoing manufacturing work by the bag-making machine. This invention is provided with guide plates 60L, 60R, guide plate robots 62L, 62R, guide bars 61L, 61R, a guide bar robot 63, and a position / orientation adjustment device 7. As a result thereof, this invention is able to ensure worker safety, and also makes it possible to adjust the guide plates 60L, 60R and the guide bars 61L, 61R even during ongoing manufacturing work by a bag-making machine 1.

Description

Flap spreading device in square bottom forming device of bag making machine, square bottom forming device in bag making machine, and bag making machine

[0001] This invention relates to a square bottom forming device in a bag making machine that flattens the bottom of a flat cylindrical body being conveyed by a bottom folding drum in the process of forming the bottom of the flat cylindrical body into a square bottom, and to a square bottom forming device in a bag making machine that forms the bottom of a flat cylindrical body into a square bottom, and to a square bottom forming device that is equipped with a flap spreading device.This invention relates to a bag making machine that produces square bottom bags, and to a square bottom forming device that is equipped with a flap spreading device.

[0002] Examples of flap spreading devices in square bottom forming devices of bag making machines are disclosed in Patent Documents 1 and 2. Patent Documents 1 and 2 will be described below.

[0003] The flap folding device described in Patent Document 1 includes a pair of left and right guide plates arranged above a bottom folding drum and a pair of left and right linear members arranged between the guide plates. The guide plates and linear members are fixed to a mounting rod via a mounting arm. Each guide plate and linear member guides a paper tube, which is rotated and transported by the bottom folding drum, between the guide plates and the bottom folding drum. The top folding flaps, which are sucked by the bottom opening device, are pressed against the guide plates and linear members, thereby folding the top folding flaps inside out from the bottom folding line. In other words, the top and bottom folding flaps are deployed flatly along the outer periphery of the bottom folding drum, and the paper tube is transported stably through the small gap between the guide plates and the bottom folding drum, preventing it from floating up.

[0004] The flap folding device described in Patent Document 2, which serves as a flap unfolding device, is composed of a pair of left and right guide plates that guide both sides of the bag opening opened by the bottom opening device. The guide plates are fixed approximately horizontally via mounting arms to a mounting rod installed horizontally above the bottom folding drum. The left and right guide plates have a flat plate portion and a vertical portion that extends downward from both ends of the flat plate portion. One end of the flat plate portion (the bottom opening device side) has an inclined portion that gradually rises toward the outer edge, and the other end of the flat plate portion is fixed to the mounting arm so as to contact the outer peripheral surface of the bottom folding drum. Furthermore, between the guide plates, a linear member that presses the center portion of the paper tube against the outer peripheral surface of the bottom folding drum is fixed to the mounting rod via a mounting arm. The paper tube rotates and is guided between the left and right guide plates and the bottom folding drum. The front folding flaps, sucked by the bottom opening device, are pressed against the flat portions of the guide plates. As the bottom folding drum rotates, the front folding flaps are folded inside out along the folding lines. In other words, by folding only the front folding flaps inside out, leaving the back folding flaps, the front and back folding flaps are unfolded flat along the outer periphery of the bottom folding drum. In this way, the paper tube with the front and back folding flaps unfolded by the flap folding device is transported in unison with the rotation of the bottom folding drum. At this time, the press roller and the bottom folding drum clamp both sides of each folding flap, folding each flap flat. Furthermore, the paper tube is transported stably through a small gap between the curved guide and limiting plates attached to the bottom folding drum and the bottom folding drum, preventing the paper tube from floating up.

[0005] JP-A No. 11-309793 JP-A No. 8-90687

[0006] The flap folding device bag making machine of Patent Document 1 requires adjustment of the position and posture of the pair of left and right guide plates and the position and posture of the pair of left and right linear members depending on the material and thickness of the base paper used and the size of the square bottom bags being produced, and also to maintain the quality of each specified number of square bottom bags produced.

[0007] However, in the flap folding device of Patent Document 1, a pair of left and right guide plates and a pair of left and right linear members are fixed to a mounting rod via a mounting arm. Therefore, when adjusting the positions and postures of the pair of left and right guide plates and the pair of left and right linear members, the manufacturing operation of the bag making machine must be temporarily stopped to ensure the safety of workers, which creates an issue in manufacturing efficiency.

[0008] Similarly, the flap folding device bag making machine of Patent Document 2 requires adjustment of the position and posture of the pair of left and right guide plates and the position and posture of the linear member depending on the material and thickness of the base paper used and the size of the square bottom bags being manufactured, and also to maintain the quality of each specified number of square bottom bags manufactured.

[0009] However, in the flap folding device of Patent Document 1, a pair of left and right guide plates are fixed to an attachment arm, and the linear member is fixed to an attachment rod via the attachment arm. Therefore, when adjusting the position and attitude of the pair of left and right guide plates and the linear member, the manufacturing operation of the bag making machine must be temporarily stopped to ensure the safety of workers, which poses a problem in manufacturing efficiency.

[0010] The problem to be solved by this invention is to provide a flap spreading device in a square bottom forming device of a bag making machine, a square bottom forming device in a bag making machine, and a bag making machine, which can ensure the safety of workers and which can adjust at least one pair of guide plates of the flap spreading device even during manufacturing operations of the bag making machine.

[0011] In order to solve the above-mentioned problems, the flap unfolding device in the square bottom forming device of a bag making machine according to a first aspect of the present invention is a flap unfolding device that folds the front flaps of the bottom portion of a flat cylindrical body being transported by a bottom folding drum inside out relative to the back flaps, and unfolds the front flaps and the back flaps in a plane along the outer peripheral surface of the bottom folding drum, and is characterized by comprising: a pair of guide plates that guide both side portions of the flat cylindrical body along the transport direction of the bottom folding drum, and unfolds the front flaps and the back flaps in a plane; a pair of robots that use the pair of guide plates as end effectors; and a position and attitude adjustment device that adjusts the position and attitude of the pair of guide plates in three-dimensional space to a target position and attitude through the operation of the pair of robots.

[0012] In the flap unfolding device in the square bottom forming device of the bag making machine of this invention, it is preferable that the position and posture adjustment device has an input unit having an operation operation unit that inputs information on the target positions and target postures of the pair of guide plates, and a control unit that controls the operation of the pair of robots based on the target position information and target posture information input to the input unit by operating the operation operation unit.

[0013] In the flap unfolding device in the square bottom forming device of the bag making machine of this invention, it is preferable that the position and attitude adjustment device controls the pair of robots to operate via the control unit when information on the target position and information on the target attitude are input to the input unit in order to adjust the position and attitude of the pair of guide plates, and controls the pair of robots to stop operation via the control unit until new information on the target position and information on the target attitude are input to the input unit in order to maintain the adjusted position and attitude of the pair of guide plates.

[0014] In the flap unfolding device in the square bottom forming device of the bag making machine of this invention, it is preferable that the input unit has an offset operation unit that inputs offset position information for positioning the pair of guide plates, which are located at the target position and in the target posture, at an offset position offset from the target position, and the control unit operates the offset operation unit to position the pair of guide plates at the offset position offset from the target position through the operation of the pair of robots.

[0015] In the flap unfolding device in the square bottom forming device of the bag making machine of this invention, it is preferable that the position and posture adjustment device has a memory unit in which the target position information and the target posture information are stored, the input unit has an information retrieval operation unit that retrieves the target position information and the target posture information stored in the memory unit, and the control unit controls the operation of the pair of robots based on the target position information and the target posture information retrieved from the memory unit by operating the information retrieval operation unit.

[0016] In the flap unfolding device in the square bottom forming device of the bag making machine of this invention, it is preferable that the input unit has an offset operation unit that inputs offset position information for positioning the pair of guide plates, which are located at the target position and in the target posture, at an offset position offset from the target position, and the control unit operates the offset operation unit to position the pair of guide plates at the offset position offset from the target position through the operation of the pair of robots.

[0017] In the flap spreading device in the square bottom forming device of the bag making machine of the present invention, it is preferable that the pair of guide plates are attached to the pair of robots via joints and cushioning materials.

[0018] The flap unfolding device in the square bottom forming device of the bag making machine of this invention preferably comprises a pair of guide bars arranged between the pair of guide plates and guiding the central portion of the flat cylindrical body along the conveying direction of the bottom folding drum to unfold the front side flaps and the back side flaps in a planar manner, and a guide bar robot using the pair of guide bars as end effectors, and the position and posture adjustment device preferably adjusts the position and posture of the pair of guide bars in three-dimensional space to a target position and target posture through the operation of the guide bar robot.

[0019] In the flap unfolding device in the square bottom forming device of the bag making machine of this invention, it is preferable that the position and posture adjustment device has an input unit having an operation operation unit that inputs information on the target position and target posture of the pair of guide bars, and a control unit that controls the operation of the guide bar robot based on the target position information and target posture information input to the input unit by operating the operation operation unit.

[0020] In the flap unfolding device in the square bottom forming device of the bag making machine of this invention, it is preferable that the position and attitude adjustment device controls the guide bar robot to operate via the control unit when information on the target position and information on the target attitude are input to the input unit in order to adjust the position and attitude of the pair of guide bars, and controls the guide bar robot to stop operation via the control unit until new information on the target position and information on the target attitude are input to the input unit in order to maintain the adjusted position and attitude of the pair of guide bars.

[0021] In the flap unfolding device in the square bottom forming device of the bag making machine of this invention, it is preferable that a guide bar mounting member is attached to the guide bar robot, and that the pair of guide bars are attached to the guide bar mounting member so as to be movable in at least one direction of the conveying direction of the bottom folding drum or a direction intersecting the conveying direction of the bottom folding drum.

[0022] In the flap unfolding device in the square bottom forming device of the bag making machine of this invention, it is preferable that a guide bar mounting member is attached to the guide bar robot via a joint and a cushioning material, and that the pair of guide bars are attached to the guide bar mounting member so as to be movable in at least one direction of the conveying direction of the bottom folding drum or a direction intersecting the conveying direction of the bottom folding drum.

[0023] In order to solve the above-mentioned problems, a square bottom forming device in a bag making machine according to a first aspect of the present invention is a square bottom forming device in a bag making machine for forming the bottom portion of a flat tubular body into a square bottom, and includes a supply device for continuously supplying the flat tubular bodies at intervals, a bottom folding line marking device for marking a bottom fold line and a bottom fold-in line on the bottom portion of the flat tubular body in a direction perpendicular to the flow direction of the production line, a bottom folding drum for transporting the flat tubular body in the flow direction of the production line, an opening device for opening the front side flap and the back side flap of the bottom portion of the flat tubular body, and a folding device for folding the front side flap inside out relative to the back side flap along the bottom fold line to open the front side flap. The folding machine is characterized by comprising: a flap unfolding device of the present invention that unfolds the flaps and the back flaps in a plane along the outer peripheral surface of the bottom folding drum; an adhesive application device that applies adhesive to the front flaps and the back flaps that have been unfolded in a plane; a raising device that raises the front flaps and the back flaps that have been coated with adhesive along the bottom fold line; an adhering device that folds the raised front flaps and the back flaps along the bottom fold line and adheres them with the adhesive; and a press device that presses the front flaps and the back flaps that have been adhered with the adhesive to form a square bottom.

[0024] In order to solve the above-mentioned problems, the bag making machine of a first aspect of this invention is a bag making machine for making square bottom bags, characterized in that it comprises a paper feeding device that continuously feeds out rolled base paper in the flow direction of the production line, a flat cylinder forming device that forms a flat, cylindrical body from the base paper fed out from the paper feeding device, and a square bottom forming device of this invention that forms a square bottom from the bottom portion of the flat cylinder formed by the flat cylinder forming device.

[0025] The bag making machine of the present invention preferably includes a handle device that forms a handle and attaches the handle to a predetermined position on the opening of the square-bottom bag.

[0026] The flap unfolding device in the square bottom forming device of the bag making machine, the square bottom forming device in the bag making machine, and the bag making machine of this invention can ensure the safety of workers, and at least one pair of guide plates of the flap unfolding device can be adjusted even during manufacturing operations of the bag making machine.

[0027] FIG. 1 is a plan view showing an embodiment of a bag making machine, a square bottom forming device, and a flap spreading device according to the present invention. FIG. 2 is a side view showing an embodiment of a bag making machine, a square bottom forming device, and a flap spreading device according to the present invention. FIG. 3 is a front view showing a square bottom bag with a round string handle. FIG. 4 is a partial perspective view showing the round string handle attached to the base paper. FIG. 5 is a partial perspective view showing a continuous flat tubular body. FIG. 6 is a perspective view showing a flat tubular body with two sets of round string handles at the opening. FIG. 7 is a perspective view showing the front and back flaps at the bottom of the flat tubular body with the front and back flaps opened. FIG. 8 is a perspective view showing the opened front flaps folded inside out relative to the back flaps along the bottom fold line. FIG. 9 is a perspective view showing the front and back flaps spread out flat along the outer circumferential surface of a bottom folding drum. FIG. 10 is a perspective view showing the flatly spread front and back flaps with adhesive applied to them. FIG. 11 is a perspective view showing a square-bottom bag with a square bottom molded on the bottom portion of a flat cylindrical body. FIG. 12 is a side view showing a flap unfolding device. FIG. 13 is a front view showing a flap unfolding device. FIG. 14 is a perspective view showing a flap unfolding device. FIG. 15 is a perspective view showing a pair of left and right guide plates and a pair of left and right guide bars of the flap unfolding device in a retracted state. FIG. 16 is an explanatory diagram showing the left guide plate 60L. (A) is a plan view. (B) is a rear view (viewed from the arrow B in (A)). (C) is a side view (viewed from the arrow C in (A)). (D) is a perspective view (viewed from the arrow D in (A)). (E) is a front view (viewed from the arrow E in (C)). FIG. 17 is a front view showing the sixth arm, joint, cushioning material, and pair of left and right guide plates of a pair of left and right guide plate robots. Fig. 18 is a side view (viewed in the direction of arrow XVIII in Fig. 17) showing the sixth arm, joint, buffer material, and pair of left and right guide plates of the pair of left and right guide plate robots. Fig. 19 is a bottom view (viewed in the direction of arrow XIX-XIX in Fig. 17) showing the sixth arm and joint of the pair of left and right guide plate robots. Fig. 20 is a bottom view (viewed in the direction of arrow XIX-XIX in Fig. 17) showing the sixth arm, joint, and mounting portion of the pair of left and right guide plates of the pair of left and right guide plate robots.Fig. 21 is a front view showing the sixth arm, joint, cushioning material, mounting member, and pair of left and right guide bars of a pair of left and right guide bar robots. Fig. 22 is a side view (viewed from the arrow XXII in Fig. 21) showing the sixth arm, joint, cushioning material, mounting member, and pair of left and right guide bars of a pair of left and right guide bar robots. Fig. 23 is a block diagram showing a position and attitude adjustment device. Fig. 24 is a block diagram showing a first input unit. Fig. 25 is a front view showing a square-bottom bag with a flat string handle on the outside.

[0028] (Explanation of the Configuration of the Embodiments) Below, an example of an embodiment (example) of a flap spreading device (hereinafter referred to as the "flap spreading device") in a square bottom forming device of a bag making machine according to the present invention, an example of an embodiment (example) of a square bottom forming device (hereinafter referred to as the "square bottom forming device") in a bag making machine according to the present invention, and an example of an embodiment (example) of a bag making machine according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to these embodiments. Furthermore, the components in the following embodiments include those that are easily replaceable by a person skilled in the art, or those that are substantially identical.

[0029] In this specification, the downstream side of the flow in the production line for base paper, flat cylindrical bodies, and square-bottom bags is referred to as the front side, and the upstream side is referred to as the rear side. Looking from the rear side of the upstream side to the front side of the downstream side, the left side is referred to as the left side, and the right side is referred to as the right side. The upper side in the vertical direction is referred to as the top side, and the lower side in the vertical direction is referred to as the bottom side.

[0030] The drawings are schematic diagrams showing the flap spreading device, square bottom forming device, and bag making machine of the present invention, and therefore only show the main components of the flap spreading device, square bottom forming device, and bag making machine, while omitting other components. Also, some hatching has been omitted. Furthermore, in the drawings, the arrow "A" indicates the flow direction of the base paper, flat cylindrical body, and square bottom bag production line, pointing from upstream to downstream. Furthermore, in the drawings, the letters "F" and "B" indicate "front side," "rear side," "L" and "right side," "U" and "upper side," and "D" and "lower side."

[0031] (Description of Configuration of the Embodiment) Hereinafter, the configurations of the flap unfolding device, square bottom forming device, and bag making machine according to this embodiment will be described.

[0032] (Explanation of Bag Making Machine 1) Figure 1 is a plan view showing the bag making machine 1, and Figure 2 is a side view showing the bag making machine 1. In this example, the bag making machine 1 produces square bottom bags 10 with round string handles 34 shown in Figures 3 and 11 (square bottom bags 10 equipped with round string handles 34; hereinafter referred to as "square bottom bags 10").

[0033] As shown in FIGS. 1 and 2, the bag making machine 1 includes a paper feeder 2, a handle device 3, a flat cylinder forming device 4, and a square bottom forming device 5.

[0034] (Description of Paper Feeder 2) The paper feeder 2 is located at the most upstream position of the bag making machine 1. The paper feeder 2 continuously feeds rolled base paper 20 in the flow direction A of the production line. The width W2 of the rolled base paper 20 is set based on the width W1 of the square bottom bag 10, as shown in Figures 3 and 4.

[0035] The width W2 of the base paper 20 is the dimension in the direction perpendicular to the flow direction A of the production line for the base paper 20. The material and thickness of the base paper 20 are optional. Furthermore, the surface of the base paper 20 may be printed.

[0036] 1 and 2, the handle device 3 is disposed between the paper feed device 2 and the flat cylinder body forming device 4. That is, the handle device 3 is disposed downstream of the paper feed device 2, and includes a handle forming device 30 and a handle attaching device 31.

[0037] The handle forming device 30 forms a round cord handle 34 (see FIGS. 3 to 11) by integrating a U-shaped round cord handle portion 32 with an attachment paper 33. The attachment paper 33 also functions as a reinforcing paper.

[0038] The handle attaching device 31 applies an adhesive (not shown) to a predetermined position on the base paper 20. The handle attaching device 31 also attaches round cord handles 34 to the applied adhesive, as shown in Figure 4. The round cord handles 34 are arranged on the left and right sides of the base paper 20, one on each side.

[0039] (Explanation of the flat tube body forming device 4) As shown in Figures 1 and 2, the flat tube body forming device 4 is arranged downstream of the handle attaching device 31 and has a gore creasing device 40, a gore attaching device 41, and a cutting device 42.

[0040] The gore crease making device 40 makes gore creases 12 in the flow direction A of the production line at predetermined locations on the base paper 20 where one round string handle 34 is arranged on each side, i.e., at locations corresponding to the gore portions 11 on both the left and right sides of the square-bottom bag 10.

[0041] The gore attachment device 41 applies an adhesive (not shown) to at least one of the left and right edge portions along the flow direction A of the base paper 20, on which one round cord handle 34 is arranged on each side of the base paper 20. As shown in Figure 5, the gore attachment device 41 folds the base paper 20 along the gore grooves 12 and attaches it with an adhesive to form a continuous flat tube 21.

[0042] As shown in Fig. 5, the cutting device 42 cuts the continuous flat tubular body 21 at a predetermined location, i.e., at a location (see the two-dot chain line in Fig. 5) that corresponds to the opening edge 14 of the mouth portion 13 of the square-bottom bag 10 shown in Figs. 3 and 11, in a direction perpendicular to the flow direction A of the production line. This results in the formation of a flat tubular body 22 having two sets of round string handles 34 at the mouth portion 13, as shown in Fig. 6.

[0043] (Explanation of square bottom forming device 5) As shown in Figures 1 and 2, the square bottom forming device 5 is arranged downstream of the flat cylinder forming device 4, and is equipped with a supply device 50, a bottom crease line forming device 51, a bottom folding drum 52, an opening device 53, a flap unfolding device 6, an adhesive application device 54, a raising device 55, a pasting device 56, and a pressing device 57.

[0044] The supply device 50 is disposed downstream of the flat cylinder molding device 4 and continuously supplies the flat cylinders 22 (see FIG. 6) molded by the flat cylinder molding device 4 at intervals.

[0045] The bottom crease marking device 51 is disposed downstream of the supply device 50. As shown in Figure 6, the bottom crease marking device 51 marks a bottom fold line 24 and a bottom fold-in line 25 in the bottom portion 23 of the flat cylindrical body 22 (the portion corresponding to the square bottom 15 of the square-bottom bag 10 shown in Figures 3 and 11) in a direction perpendicular to the flow direction A of the production line. The bottom crease line 24 and the bottom fold-in line 25 are parallel to each other.

[0046] The bottom folding drum 52 rotates to convey the flat cylindrical body 22, on which the bottom folding line 24 and the bottom fold line 25 have been formed by the bottom folding line forming device 51, in the flow direction A of the production line. The bottom folding drum 52 is provided with a catch claw (not shown).

[0047] The opening device 53 is disposed downstream of the bottom folding device 51 and is disposed close to the outer peripheral surface of the bottom folding drum 52. The opening device 53 is provided with a suction pad (not shown). As shown in FIG. 7, the suction pad suctions the front flap 26 of the bottom portion 23 of the flat cylindrical body 22 and opens it toward the back flap 27 of the bottom portion 23 of the flat cylindrical body 22. At this time, the back flap 27 is captured by the capturing claws of the bottom folding drum 52 and is rotated and conveyed along the outer peripheral surface of the bottom folding drum 52. As a result, the front flap 26 and the back flap 27 of the bottom portion 23 of the flat cylindrical body 22 are opened, as shown in FIG. 7.

[0048] 8 and 9, the flap unfolding device 6 folds the front flap 26 opened by the opening device 53 inside out relative to the back flap 27 along the bottom folding line 24, and unfolds the front flap 26 and the back flap 27 in a plane along the outer circumferential surface of the bottom folding drum 52. The flap unfolding device 6 will be described in detail later.

[0049] The adhesive applicator 54 is disposed downstream of the flap unfolding device 6 on the outer peripheral surface of the bottom folding drum 52. As shown in Fig. 10 , the adhesive applicator 54 applies adhesive 28 (see the hatched portion in Fig. 10 ) to the front flap 26 and the back flap 27 that are unfolded in a plane.

[0050] The raising device 55 is disposed downstream of the adhesive applying device 54 and on the outer peripheral surface of the bottom folding drum 52. The raising device 55 raises the front flap 26 and the back flap 27, to which the adhesive 28 has been applied, along the bottom folding line 25.

[0051] The bonding device 56 is disposed downstream of the raising device 55 on the outer peripheral surface of the bottom folding drum 52. As shown in Fig. 11, the bonding device 56 folds the raised front flap 26 and back flap 27 along the bottom fold line 25 and bonds them together with an adhesive 28.

[0052] 1 and 2, the press device 57 is disposed downstream of the bonding device 56. As shown in FIGS. 3 and 11, the press device 57 presses the front flap 26 and the back flap 27, which are bonded together with the adhesive 28, to form the square bottom 15 on the bottom portion 23 of the flat cylindrical body 22. In this way, the square-bottom bag 10 is manufactured.

[0053] (Explanation of flap unfolding device 6) As shown in Figures 12 to 24, the flap unfolding device 6 includes a pair of left and right guide plates (also called binders) 60L, 60R, a pair of left and right guide bars (also called beating bars) 61L, 61R, a pair of left and right guide plate robots 62L, 62R, a guide bar robot 63, and a position and posture adjustment device 7.

[0054] (Description of the pair of left and right guide plates 60L, 60R) The pair of left and right guide plates 60L, 60R are attached to the pair of left and right guide plate robots 62L, 62R as end effectors of the pair of left and right guide plate robots 62L, 62R via joints 64 described below.

[0055] The left guide plate 60L of the pair of left and right guide plates 60L, 60R may hereinafter be referred to as the "left guide plate 60L." Furthermore, the right guide plate 60R of the pair of left and right guide plates 60L, 60R may hereinafter be referred to as the "right guide plate 60R."

[0056] In the process of folding the front flap 26 inside out along the bottom folding line 24 relative to the back flap 27, a pair of left and right guide plates 60L, 60R guide both left and right side portions of the flat cylindrical body 22 along the rotational conveying direction C of the bottom folding drum 52, thereby unfolding the front flap 26 and the back flap 27 in a flat plane.

[0057] 16 is an explanatory diagram showing the left guide plate 60L. The left guide plate 60L will be described below. The right guide plate 60R is bilaterally symmetrical to the left guide plate 60L, so a description of the right guide plate 60R will be omitted. The guide plate 60L has a horizontal plate portion 600, a curved portion 601, a rising plate portion 602, and an attachment portion 603.

[0058] The horizontal plate portion 600 has a rectangular plate shape and is located close to and opposite the outer peripheral surface of the bottom folding drum 52, pressing both left and right side portions of the flat cylindrical body 22 against the outer peripheral surface of the bottom folding drum 52.

[0059] The rising plate portion 602 is formed by raising a portion of the horizontal plate portion 600 via the curved portion 601 , and guides both the left and right sides of the flat cylindrical body 22 to the horizontal plate portion 600 together with the curved portion 601 .

[0060] The rising plate portion 602 is provided integrally with the central portion of the upper surface of the horizontal plate portion 600 and is attached to the guide plate robots 62L and 62R via joints 64.

[0061] (Explanation of the Pair of Left and Right Guide Bars 61L, 61R) The pair of left and right guide bars 61L, 61R are attached to the guide bar robot 63 as end effectors of the guide bar robot 63 via joints 64 and guide bar attachment members 65, which will be described later. Note that the pair of left and right guide bars 61L, 61R may hereinafter be referred to as "central guide bars 61L, 61R."

[0062] The pair of left and right guide bars 61L, 61R are disposed between the pair of left and right guide plates 60L, 60R. In the process of folding the front flap 26 inside out relative to the back flap 27 along the bottom folding line 24, the pair of left and right guide bars 61L, 61R guide the central portion of the flat cylindrical body 22 along the rotational conveying direction C of the bottom folding drum 52, thereby unfolding the front flap 26 and the back flap 27 in a plane.

[0063] 12, the pair of left and right guide bars 61L, 61R are formed by bending the central portion 610 of a round rod member. One end portion 611 of the pair of left and right guide bars 61L, 61R is attached to a guide bar robot 63 via a guide bar attachment member 65. The other end portion 612 of the pair of left and right guide bars 61L, 61R is disposed between the pair of left and right guide plates 60L, 60R, and faces closely to the outer peripheral surface of the bottom folding drum 52, guiding the central portion of the flat cylindrical body 22 and pressing it against the outer peripheral surface of the bottom folding drum 52.

[0064] (Explanation of the Pair of Left and Right Guide Plate Robots 62L, 62R) As shown in Figures 12 to 15, the pair of left and right guide plate robots 62L, 62R are provided on both the left and right sides of the ceiling frame 60. The ceiling frame 60 is integral with the frame (not shown) of the square bottom forming device 5, and is arranged on the ceiling part of the square bottom forming device 5 in the left-right direction perpendicular to the flow direction A of the production line.

[0065] Of the pair of left and right guide plate robots 62L, 62R, the left guide plate robot 62L may be referred to as the "first robot 62L" below. Also, of the pair of left and right guide plate robots 62L, 62R, the right guide plate robot 62R may be referred to as the "third robot 62R" below.

[0066] The pair of left and right guide plate robots 62L, 62R have fixed arms 620L, 620R, first arms 621L, 621R, second arms 622L, 622R, third arms 623L, 623R, fourth arms 624L, 624R, fifth arms 625L, 625R, and sixth arms 626L, 626R.

[0067] The fixed arms 620L, 620R are fixed to both the left and right sides of the ceiling mount 60. The first arms 621L, 621R are attached to the fixed arms 620L, 620R so as to be rotatable around a first axis (not shown). The second arms 622L, 622R are attached to the first arms 621L, 621R so as to be rotatable around a second axis (not shown). The third arms 623L, 623R are attached to the second arms 622L, 622R so as to be rotatable around a third axis (not shown). The fourth arms 624L, 624R are attached to the third arms 623L, 621R so as to be rotatable around a fourth axis (not shown). The fifth arms 625L, 625R are attached to the fourth arms 624L, 624R so as to be rotatable around a fifth axis (not shown). The sixth arms 626L and 626R are attached to the fifth arms 625L and 625R so as to be rotatable about a sixth axis (not shown).

[0068] The first arms 621L, 621R to the sixth arms 626L, 626R are rotationally driven by servo motors. A pair of left and right guide plates 60L, 60R are attached to the sixth arms 626L, 626R via joints 64.

[0069] 12 to 15, the guide bar robot 63 is provided in the center of the ceiling frame 60, between the pair of left and right guide plate robots 62L, 62R. Note that the guide bar robot 63 may hereinafter be referred to as the "second robot 63."

[0070] The guide bar robot 63 has a fixed arm 630 , a first arm 631 , a second arm 632 , a third arm 633 , a fourth arm 634 , a fifth arm 635 , and a sixth arm 636 .

[0071] The fixed arm 630 is fixed to the center of the ceiling mount 60. The first arm 631 is attached to the fixed arm 630 so as to be rotatable around a first axis (not shown). The second arm 632 is attached to the first arm 631 so as to be rotatable around a second axis (not shown). The third arm 633R is attached to the second arm 632 so as to be rotatable around a third axis (not shown). The fourth arm 634 is attached to the third arm 633 so as to be rotatable around a fourth axis (not shown). The fifth arm 635 is attached to the fourth arm 634 so as to be rotatable around a fifth axis (not shown). The sixth arm 636 is attached to the fifth arm 635 so as to be rotatable around a sixth axis (not shown).

[0072] The first arm 631 to the sixth arm 636 are rotationally driven by servo motors. A pair of left and right guide bars 61L, 61R are attached to the sixth arm 636 via a joint 64 and a guide bar attachment member 65.

[0073] (Explanation of Joint 64) As shown in Figures 17 to 22, the joint 64 has a disk-shaped main body 640 and a plate-shaped attachment portion 641 that is integrally formed in the central portion of one surface (lower surface) of the main body 640.

[0074] 17 to 20, the other surface (upper surface) of the main body 640 is attached to one surface (lower surface) of the sixth arms 626L, 626R of the pair of left and right guide plate robots 62L, 62R with shock absorbers 644 interposed therebetween by bolts 643. Furthermore, the other surface (upper surface) of the main body 640 is attached to one surface (lower surface) of the sixth arm 636 of the guide bar robot 63 with shock absorbers 644 interposed therebetween by bolts 643, as shown in FIGS. 21 and 22. The shock absorbers 644 may be of one type or multiple types.

[0075] 17, 18, and 20, the mounting portions 603 of the pair of left and right guide plates 60L, 60R are attached to the mounting portion 641 with bolts and nuts 642. Also, as shown in FIGS. 21 and 22, the first mounting portion 651 of the guide bar mounting member 65 is attached to the mounting portion 641 with bolts and nuts 642.

[0076] (Explanation of guide bar mounting member 65) As shown in Figures 21 and 22, the guide bar mounting member 65 has a main body portion 650, a first mounting portion 651, two mounting shaft portions 652, a pair of left and right slide portions 653L, 653R, and a pair of left and right second mounting portions 654L, 654R.

[0077] The main body 650 has a shape formed by bending both left and right end portions downward of a rectangular plate member that is long in the left-right direction. A first mounting portion 651 is integrally provided in the center portion of the top surface of the main body 650. The first mounting portion 651 is attached to the mounting portion 641 of the joint 64 with bolts and nuts 642. The front and rear of both left and right end portions of the main body 650 are attached at their end faces with bolts 655 to the front and rear of the main body 650.

[0078] A pair of left and right slide portions 653L, 653R are attached to the two mounting shaft portions 652 by bolts and nuts 656 so as to be slidable in the left-right direction. A pair of left and right second mounting portions 654L, 654R are integrally provided on the inner surfaces of the pair of left and right slide portions 653L, 653R, i.e., on the surfaces where the pair of left and right slide portions 653L, 653R face each other.

[0079] The pair of left and right second mounting portions 654L, 654R, together with the pair of left and right slide portions 653L, 653R, are slidable in the left-right direction relative to the two mounting shafts 652. One end portions 611 of the pair of left and right guide bars 61L, 61R are attached to the pair of left and right second mounting portions 654L, 654R by bolts and nuts 657 so as to be slidable in the front-rear direction.

[0080] The pair of left and right guide bars 61L, 61R are attached to the guide bar attachment member 65 so as to be movable in the left-right direction and the front-rear direction, but they may also be attached so as to be movable in the left-right direction or the front-rear direction.

[0081] (Description of position and orientation adjustment device 7) The position and orientation adjustment device 7 is, for example, a personal computer, and as shown in FIG. 23, has a first input unit 71, a second input unit 72, a third input unit 73, a memory unit 74, and a control unit 70.

[0082] The first input unit 71 adjusts the position and orientation of the left guide plate 60L via the first robot 62L through operation of the operation unit. The second input unit 72 adjusts the position and orientation of the central guide bars 61L, 61R via the second robot 63 through operation of the operation unit. The third input unit 73 adjusts the position and orientation of the right guide plate 60R via the third robot 62R through operation of the operation unit.

[0083] The first input unit 71 will be described below with reference to Fig. 24. Note that the second input unit 72 and the third input unit 73 have the same configuration as the first input unit 71, and therefore their description will be omitted.

[0084] As shown in FIG. 24, the first input unit 71 has six linear motion operation units, six rotational motion operation units, an information extraction operation unit, and an offset operation unit.

[0085] The first input unit 71 receives input of information on the target position and target orientation of the left guide plate 60L in three-dimensional space by the operator operating the six linear motion operation units and the six rotational motion operation units. The first input unit 71 also receives input of information on the target position and target orientation stored in the memory unit 74 by the operator operating the information retrieval operation unit. The first input unit 71 also receives input of offset position information by the operator operating the offset operation unit. The offset position information is information for positioning the left guide plate 60L, which is located at the target position and in the target orientation, to an offset position offset from the target position.

[0086] In this example, the position and orientation in three-dimensional space are expressed in a right-handed Cartesian coordinate system with a predetermined point as the origin. The X-axis is the front-to-back direction, with the front side F being + and the back side B being -. The Y-axis is the left-to-right direction, with the right side R being + and the left side L being -. The Z-axis is the up-down direction, with the upper side U being + and the lower side D being -. The clockwise rotation of the X-axis is + and the counterclockwise rotation of the X-axis is -. The clockwise rotation of the Y-axis is + and the counterclockwise rotation of the Y-axis is -. The clockwise rotation of the Z-axis is + and the counterclockwise rotation of the Z-axis is -. Note that the position and orientation in three-dimensional space may also be expressed in a left-handed Cartesian coordinate system.

[0087] The storage unit 74 includes, for example, a RAM, a solid state drive (SSD), or a hard disk drive (HDD). The storage unit 74 stores information on the target position and target orientation of the left guide plate 60L, information on the target position and target orientation of the central guide bars 61L and 61R, and information on the target position and target orientation of the right guide plate 60R. The information on the target position and target orientation stored in the storage unit 74 is retrieved by operating the information retrieval operation units of the first input unit 71, the second input unit 72, and the third input unit 73.

[0088] The information on the target position and the information on the target posture stored in the memory unit 74 includes information obtained by a worker operating the operation units of the first input unit 71, the second input unit 72, and the third input unit 73, and information obtained by a skilled worker operating the operation units of the first input unit 71, the second input unit 72, and the third input unit 73.

[0089] The control unit 70 is composed of other elements including a CPU (Central Processing Unit) and storage units (e.g., ROM (Read Only Memory), RAM (Random Access Memory), non-volatile memory, etc.). The control unit 70 controls the operations of the first robot 62L, the second robot 63, and the third robot 62R based on information on the target position and target orientation of the left guide plate 60L, the target position and target orientation of the central guide bars 61L and 61R, and the target position and target orientation of the right guide plate 60R, which are input to a first input unit 71, a second input unit 72, and a third input unit 73 (hereinafter sometimes referred to as "input units 71, 72, 73") through the operation of six linear motion operation units and six rotational motion operation units.

[0090] The control unit 70 controls the operation of the first robot 62L, the operation of the second robot 63, and the operation of the third robot 62R based on the target position information and target posture information of the left guide plate 60L, the target position information and target posture information of the central guide bars 61L and 61R, and the target position information and target posture information of the right guide plate 60R, which are retrieved from the memory unit 74 and input to the input units 71, 72, and 73 by operating the information retrieval operation unit.

[0091] The control unit 70 controls the operation of the first robot 62L, the operation of the second robot 63, and the operation of the third robot 62R based on the offset position information of the left guide plate 60L, the offset position information of the central guide bars 61L and 61R, and the offset position information of the right guide plate 60R input to the input units 71, 72, and 73 by operating the offset operation unit.

[0092] That is, the control unit 70 operates the first robot 62L, the second robot 63, and the third robot 62R (hereinafter sometimes referred to as "robots 62L, 63, 62R") to position the left guide plate 60L, the central guide bars 61L, 61R, and the right guide plate 60R (hereinafter sometimes referred to as "guides 60L, 61L, 61R, 60R") at the target position, production line A, and set them in the target posture, and also offset them from the target positions shown in Figures 12 to 14 to the offset position shown in Figure 15. The guides 60L, 61L, 61R, 60R located at the offset position shown in Figure 15 are in a retracted state and are far away from the target position, production line A.

[0093] The position and attitude adjustment device 7 controls the operation of the robots 62L, 63, and 62R as follows. That is, when information on a target position and information on a target attitude are input to the input units 71, 72, and 73 in order to adjust the positions and attitudes of the guides 60L, 61L, 61R, and 60R, the position and attitude adjustment device 7 controls the operation of the robots 62L, 63, and 62R via the control unit 70. Furthermore, in order to maintain the adjusted positions and attitudes of the guides 60L, 61L, 61R, and 60R, the position and attitude adjustment device 7 controls the operation of the robots 62L, 63, and 62R via the control unit 70 to stop until new information on the target position and information on the target attitude is input to the input units 71, 72, and 73.

[0094] (Explanation of Operation of the Embodiment) The flap unfolding device 6, square bottom forming device 5, and bag making machine 1 according to this embodiment are configured as described above, and their operation will be described below.

[0095] The paper feeder 2 of the bag making machine 1 supplies the base paper 20. Meanwhile, the handle device 3 of the bag making machine 1 forms a round cord handle 34 consisting of a round cord handle portion 32 and an attachment paper 33, and attaches the round cord handle 34 to the base paper 20 (see FIG. 4).

[0096] The flat cylinder forming device 4 of the bag making machine 1 forms the base paper 20 to which the round string handles 34 are attached into a continuous flat cylinder 21 (see Figure 5), and also forms a flat cylinder 22 from the continuous flat cylinder 21, which has two sets of round string handles 34 at the opening 13 (see Figure 6).

[0097] The square-bottom forming device 5 of the bag making machine 1 opens the bottom portion 23 of the flat cylindrical body 22 (see Figure 7), and the flap spreading device 6 flattens the opened bottom portion 23 of the flat cylindrical body 22 (see Figures 8 and 9), and then attaches the flattened bottom portion 23 of the flat cylindrical body 22 (see Figures 10 and 11), thereby forming the square-bottom bag 10 (see Figures 3 and 11).

[0098] When forming a square-bottom bag 10 from new base paper 20, the bag making machine 1 operates the position and attitude adjustment device 7 of the flap unfolding device 6 to position the guides 60L, 61L, 61R, and 60R at the optimal target positions and attitudes for the new base paper 20. In other words, base paper 20 varies in characteristics such as material and thickness, lot size, and waste paper recycling rate. For this reason, it is necessary to operate the position and attitude adjustment device 7 to adjust the positions and attitudes of the guides 60L, 61L, 61R, and 60R for each base paper 20.

[0099] Here, the position and attitude adjustment device 7 is operated either by an operator or by retrieving information stored in the storage unit 74 .

[0100] During the manufacturing process of the bag making machine 1, the molded square-bottom bags 10 are randomly removed and their quality checked. If the square-bottom bags 10 are molded according to the specified design, the manufacturing process continues as is. However, if the square-bottom bags 10 are not molded according to the specified design, the position and orientation adjustment device 7 must be operated to adjust the positions and orientations of the guides 60L, 61L, 61R, and 60R again, so that the guides 60L, 61L, 61R, and 60R are positioned at the optimal target positions and orientations.

[0101] Furthermore, during the manufacturing process of the bag making machine 1, the positions and postures of the guides 60L, 61L, 61R, and 60R may be automatically adjusted based on the information stored in the memory unit 74 for a predetermined number of square bottom bags 10, for example, every 100 units or every 1,000 units, and the guides 60L, 61L, 61R, and 60R may be repositioned to the optimal target position and posture.

[0102] Furthermore, in addition to the above cases, the position and posture adjustment device 7 may be operated to adjust the position and posture of the guides 60L, 61L, 61R, and 60R depending on the environment or season in which the bag making machine 1 is operated, and may also be performed after the guides 60L, 61L, 61R, and 60R are replaced with separate guides 60L, 61L, 61R, and 60R.

[0103] When the position and orientation adjustment device 7 is operated, the robots 62L, 63, and 62R operate to adjust the guides 60L, 61L, 61R, and 60R to be positioned at optimal target positions and to assume optimal target orientations. Furthermore, until the position and orientation adjustment device 7 is next operated, the robots 62L, 63, and 62R are stationary, and the guides 60L, 61L, 61R, and 60R maintain their optimal target positions and assume optimal target orientations.

[0104] (Explanation of Effects of the Embodiment) The flap unfolding device 6, square bottom forming device 5, and bag making machine 1 according to this embodiment have the above-described configurations and functions, and the effects thereof will be described below.

[0105] The flap unfolding device 6 in this embodiment comprises a pair of left and right guide plates 60L, 60R, a pair of left and right guide plate robots 62L, 62R that use the pair of left and right guide plates 60L, 60R as end effectors, a pair of left and right guide bars 61L, 61R that are arranged between the pair of left and right guide plates 60L, 60R, a guide bar robot 63 that uses the pair of left and right guide bars 61L, 61R as end effectors, and a position and posture adjustment device 7.

[0106] The position and posture adjustment device 7 adjusts the position and posture in three-dimensional space of the pair of left and right guide plates 60L, 60R to the target position and posture through the operation of the pair of left and right guide plate robots 62L, 62R, and adjusts the position and posture in three-dimensional space of the pair of left and right guide bars 61L, 61R to the target position and posture through the operation of the guide bar robot 63.

[0107] As a result, in the flap unfolding device 6 according to this embodiment, the adjustment work of the guides 60L, 61L, 61R, 60R that is normally performed by a worker can be performed by the robots 62L, 63, 62R, thereby ensuring the safety of the worker.

[0108] Furthermore, the flap unfolding device 6 according to this embodiment can adjust the guides 60L, 61L, 61R, and 60R to the optimal target positions and postures in a short time. As a result, the flap unfolding device 6 according to this embodiment can reduce production losses of square-bottom bags 10 that would otherwise be caused by long adjustment times, thereby improving the production efficiency of the bag making machine 1. In other words, the flap unfolding device 6 according to this embodiment can reduce production losses of square-bottom bags 10 and downtime of the bag making machine 1.

[0109] In the flap deployment device 6 according to this embodiment, the position and posture adjustment device 7 has a first input unit 71, a second input unit 72, and a third input unit 73 each having an operation operation unit for inputting information on the target position and target posture of the guides 60L, 61L, 61R, and 60R, and a control unit 70 that controls the operation of the robots 62L, 63, and 62R based on the target position information and target posture information input to the first input unit 71, the second input unit 72, and the third input unit 73 by operating the operation operation unit.

[0110] As a result, the flap deployment device 6 according to this embodiment can position the guides 60L, 61L, 61R, and 60R individually at the target positions and in the target attitudes.

[0111] In the flap unfolding device 6 according to this embodiment, when information on the target position and information on the target attitude are input to the input units 71, 72, 73 in order to adjust the positions and attitudes of the guides 60L, 61L, 61R, 60R, the position and attitude adjustment device 7 controls the robots 62L, 63, 62R to operate via the control unit 70, and controls the robots 62L, 63, 62R to stop operating via the control unit 70 until new information on the target position and information on the target attitude is input to the input units 71, 72, 73 in order to maintain the adjusted positions and attitudes of the guides 60L, 61L, 61R, 60R.

[0112] As a result, in the flap spreading device 6 according to this embodiment, when the position and attitude adjustment device 7 is operated, the robots 62L, 63, and 62R operate to adjust the guides 60L, 61L, 61R, and 60R so that they are positioned at the optimum target positions and take the optimum target attitudes. As a result, in the flap spreading device 6 according to this embodiment, the robots 62L, 63, and 62R operate in place of the operator to adjust the positions and attitudes of the guides 60L, 61L, 61R, and 60R without stopping the operation of the bag making machine 1, thereby ensuring the safety of the operator.

[0113] Furthermore, the flap unfolding device 6 according to this embodiment can adjust the position and posture of the guides 60L, 61L, 61R, 60R through the operation of the robots 62L, 63, 62R in place of an operator while the bag making machine 1 is running, making it possible to grasp subtle conditions and changes in the square bottom 15 of the square bottom bag 10. As a result, the flap unfolding device 6 according to this embodiment can shorten the time required to adjust the guides 60L, 61L, 61R, 60R and improve the production efficiency of square bottom bags 10.

[0114] Furthermore, the flap spreading device 6 according to this embodiment stops the operation of the robots 62L, 63, 62R and maintains the adjusted positions and orientations of the guides 60L, 61L, 61R, 60R until the next operation of the position and orientation adjustment device 7. This allows the flap spreading device 6 according to this embodiment to continue operating the bag making machine 1 without adjusting the positions and orientations of the guides 60L, 61L, 61R, 60R, thereby improving the production efficiency of square-bottom bags 10.

[0115] In the flap deployment device 6 according to this embodiment, the position and attitude adjustment device 7 has a memory unit 74 in which target position information and target attitude information are stored, the input units 71, 72, and 73 have information retrieval operation units that retrieve the target position information and target attitude information stored in the memory unit 74, and the control unit 70 controls the operations of the robots 62L, 63, and 62R based on the target position information and target attitude information retrieved from the memory unit 74 by operating the information retrieval operation unit.

[0116] As a result, the flap unfolding device 6 according to this embodiment can adjust the guides 60L, 61L, 61R, and 60R in an even shorter time than adjustments made by operating the operation control unit. As a result, the flap unfolding device 6 according to this embodiment can reduce production losses of square-bottom bags 10 caused by longer adjustment times, and can improve the production efficiency of the bag making machine 1.

[0117] Here, the target position information and target posture information are databases of adjustments made by skilled workers that have been digitized, so that the highly accurate adjustments made by skilled workers through years of experience can be reproduced, improving production efficiency. Moreover, by associating the skilled worker's adjustment information with information such as the characteristics and properties of the base paper 20 and information such as the environment and season in which the bag making machine 1 is operated, even more accurate adjustments can be obtained, improving production efficiency.

[0118] In the flap deployment device 6 according to this embodiment, the first input unit 71, the second input unit 72, and the third input unit 73 have an offset operation unit that inputs offset position information for positioning the guides 60L, 61L, 61R, and 60R, which are located at the target position and in the target posture, at offset positions offset from the target position, and the control unit 70 operates the offset operation unit to position the guides 60L, 61L, 61R, and 60R at the offset positions shown in FIG. 15, which are offset from the target positions shown in FIGS. 12 to 14, through the operation of the robots 62L, 63, and 62R.

[0119] As a result, when the base paper 20, the round string handle 34, or the square-bottom bag 10 becomes jammed, or when the mold for the square-bottom bag 10 is replaced, the flap unfolding device 6 according to this embodiment can offset the guides 60L, 61L, 61R, and 60R far away from the production line A, as shown in Figure 15. This allows the flap unfolding device 6 according to this embodiment to easily remove jams or replace molds.

[0120] The flap unfolding device 6 according to this embodiment has a pair of left and right guide plates 60L, 60 attached to a pair of left and right guide plate robots 62L, 62R via joints 64 and cushioning materials 644. As a result, in the flap unfolding device 6 according to this embodiment, when the pair of left and right guide plates 60L, 60 press the flat cylindrical body 22 against the outer peripheral surface of the bottom-folding drum 52, the cushioning materials 644 provide cushioning, allowing the flat cylindrical body 22 to conform to the outer peripheral surface of the bottom-folding drum 52, and enabling the production of high-precision square-bottom bags 10.

[0121] The flap unfolding device 6 according to this embodiment has a guide bar mounting member 65 attached to a guide bar robot 63, and a pair of left and right guide bars 61L, 61R attached to the guide bar mounting member 65 so as to be movable in the conveying direction (front-rear direction) of the bottom folding drum 52 and in a direction (left-right direction) intersecting the conveying direction of the bottom folding drum 52. As a result, the flap unfolding device 6 according to this embodiment allows the left-right and front-rear positions of the pair of left and right guide bars 61L, 61R to be manually adjusted separately for one guide bar robot 63.

[0122] The flap unfolding device 6 in this embodiment has a pair of left and right guide bars 61L, 61R attached to a single guide bar robot 63 via a guide bar mounting member 65, so only one expensive robot is required, thereby reducing the manufacturing costs of the device.

[0123] In the flap unfolding device 6 according to this embodiment, a guide bar mounting member 65 is attached to a guide bar robot 63 via a cushioning material 644. As a result, in the flap unfolding device 6 according to this embodiment, when the pair of left and right guide bars 61L, 61R press the flat cylindrical body 22 against the outer peripheral surface of the bottom-folding drum 52, the cushioning material 644 provides cushioning, allowing the flat cylindrical body 22 to conform to the outer peripheral surface of the bottom-folding drum 52, and enabling the production of high-precision square-bottom bags 10.

[0124] The square bottom forming device 5 according to this embodiment is equipped with the flap unfolding device 6 according to this embodiment, and therefore can achieve the same effects as those of the flap unfolding device 6 according to this embodiment.

[0125] The bag making machine 1 of this embodiment is equipped with the square bottom forming device 5 of this embodiment, and therefore can achieve the same effects as those of the square bottom forming device 5 of this embodiment and the flap unfolding device 6 of this embodiment.

[0126] (Comparison between the embodiment and the comparative example) The adjustment of the position and attitude in three-dimensional space of the guides 60L, 61L, 61R, and 60R by the flap deployment device 6 according to this embodiment will be compared with the adjustment of the position and attitude in three-dimensional space of the guides 60L, 61L, 61R, and 60R by the flap deployment device of the comparative example. Note that, among the components of the flap deployment device of the comparative example, the same components as those of the flap deployment device 6 according to this embodiment will be assigned the same reference numerals.

[0127] In the flap deployment device 6 according to this embodiment, the robots 62L, 63, 62R adjust the positions and postures of the guides 60L, 61L, 61R, 60R in three-dimensional space on behalf of the worker by operating the position and posture adjustment device 7. In contrast, in the flap deployment device of the comparative example, the worker manually adjusts the positions and postures of the guides 60L, 61L, 61R, 60R in three-dimensional space.

[0128] For this reason, in the flap unfolding device of the comparative example, when adjusting the guides 60L, 61L, 61R, and 60R, to ensure the safety of workers, it is necessary to stop the operation of the entire bag making machine 1. As a result, in the flap unfolding device of the comparative example, if the adjustment of the guides 60L, 61L, 61R, and 60R increases, the loss of square bottom bags 10 and the downtime of the bag making machine 1 increase.

[0129] Furthermore, adjusting guides 60L, 61L, 61R, and 60R requires adjusting their positions in the X-axis, Y-axis, and Z-axis directions in three-dimensional space, as well as their orientations around the X-axis, Y-axis, and Z-axis, making the adjustment work complicated. If this complicated adjustment work is performed by a worker, it takes a lot of time, and there is variation in the adjustment accuracy depending on the worker, which also leads to variation in the quality of the square-bottom bags 10 produced.

[0130] On the other hand, in the flap spreading device 6 according to this embodiment, an operator operates the position and orientation adjustment device 7 to use the robots 62L, 63, and 62R to adjust the positions and orientations of the guides 60L, 61L, 61R, and 60R in three-dimensional space. Therefore, the flap spreading device 6 according to this embodiment allows the robots 62L, 63, and 62R to perform adjustment work without stopping the operation of the entire bag making machine 1, thereby reducing loss of square-bottom bags 10 and downtime of the bag making machine 1. Moreover, in the flap spreading device 6 according to this embodiment, an operator simply operates the position and orientation adjustment device 7, and the robots 62L, 63, and 62R perform adjustment work under the control of the position and orientation adjustment device 7. Therefore, compared to the flap spreading device of the comparative example, the operation time can be shortened and variations in adjustment accuracy due to operators and variations in the quality of the square-bottom bags 10 can be reduced.

[0131] (Explanation of Examples Other Than the Embodiments) The bag making machine 1, square bottom forming device 5, and flap spreading device 6 of the present invention are not limited to the above-described embodiments.

[0132] In the above embodiment, an example is described in which a pair of left and right guide plates 60L, 60R, a pair of left and right guide plate robots 62L, 62R, and a pair of left and right guide bars 61L, 61R, and a guide bar robot 63 are provided. However, in this invention, a pair of left and right guide plates 60L, 60R, and a pair of left and right guide plate robots 62L, 62R may be provided without a pair of left and right guide bars 61L, 61R, and a guide bar robot 63. Also, in this invention, a pair of left and right guide plates 60L, 60R, a pair of left and right guide plate robots 62L, 62R, and a pair of left and right guide bars 61L, 61R may be provided without a guide bar robot 63. In other words, in this invention, it is sufficient that the position and orientation of the pair of left and right guide plates 60L, 60R can be adjusted by at least a pair of left and right guide plate robots 62L, 62R. The bag making machine, square bottom forming device, and flap spreading device of examples other than this embodiment can achieve effects almost similar to those of the bag making machine 1, square bottom forming device 5, and flap spreading device 6 of the above-mentioned embodiment.

[0133] In the above embodiment, the bag making machine 1 shown in Figure 3 is described as producing square bottom bags 10 with round string handles 34. However, in this invention, the bag making machine may be a bag making machine other than the bag making machine 1 shown in Figure 3 that produces square bottom bags 10 with round string handles 34. For example, it may be a bag making machine that produces square bottom bags 10A with external flat string handles 34A (square bottom bags 10A with external flat string handles 34A) as shown in Figure 25, or a bag making machine that produces square bottom bags with inward-folded flat string handles (square bottom bags with inward-folded flat string handles), not shown, or a bag making machine that produces square bottom bags without handles (plain square bottom bags), not shown.

[0134] Here, a bag making machine that produces square bottom bags 10A with outward-facing flat string handles 34A and a bag making machine that produces square bottom bags with inward-folded flat string handles must be equipped with a handle forming device that forms flat string handles 32A instead of the handle forming device 30 that forms round string handles 34. Furthermore, a bag making machine that produces square bottom bags without handles does not require a handle forming device or handle attaching device.

[0135] In the above embodiment, an example is described in which a pair of left and right guide bars 61L, 61R are attached to a single guide bar robot 63 via a guide bar attachment member 65. However, in the present invention, the pair of left and right guide bars 61L, 61R may be attached to a pair of left and right guide bar robots via a guide bar attachment member or joint 64. In this case, the pair of left and right guide bars 61L, 61R can be adjusted individually and more precisely. This makes it possible to accommodate cases where more precise adjustment of the pair of left and right guide bars 61L, 61R is required.

[0136] In the above embodiment, the storage unit 74 is included. However, in the present invention, the storage unit 74 may not be included.

[0137] REFERENCE SIGNS LIST 1 bag making machine 10 square bottom bag 11 gusset portion 12 gusset groove 13 opening portion 14 opening edge 15 square bottom 2 paper feeder 20 base paper 21 continuous flat cylinder 22 flat cylinder 23 bottom portion 24 bottom fold line 25 bottom fold line 26 front flap 27 back flap 28 adhesive 3 handle device 30 handle forming device 31 handle attaching device 32 round string handle portion 33 attaching paper 34 round string handle 4 flat cylinder forming device 40 gusset groove attaching device 41 gusset attaching device 42 cutting device 5 square bottom forming device 50 feeding device 51 bottom fold line attaching device 52 bottom folding drum 53 opening device 54 adhesive application device 55 Standing device 56 Bonding device 57 Pressing device 6 Flap unfolding device 60L, 60R Pair of left and right guide plates 600 Horizontal plate portion 601 Curved portion 602 Standing plate portion 603 Mounting portion 61L, 61R Pair of left and right guide bars 610 Central portion 611 One end portion 612 Other end portion 62L, 62R Pair of left and right guide plate robots 620L, 620R Fixed arm 621L, 621R First arm 622L, 622R Second arm 623L, 623R Third arm 624L, 624R Fourth arm 625L, 625R Fifth arm 626L, 626R Sixth arm 63 Guide bar robot 630 Fixed arm 631 First arm 632 Second arm 633 Third arm 634 Fourth arm 635 Fifth arm 636 Sixth arm 64 Joint 640 Main body 641 Mounting portion 642 Bolt nut 643 Bolt 644 Cushioning material 65 Guide bar mounting member 650 Main body 651 First mounting portion 652 Mounting shaft portion 653L, 653R Pair of left and right slide portions 654L, 654R Pair of left and right second mounting portions 655 Bolt 656 Bolt nut 657 Bolt nut 7 Position and attitude adjustment device 70 Control unit 71 First input unit 72 Second input unit 73 Third input unit 74 Memory unit 10A Square bottom bag 32A Flat string handle portion 34A Flat string handleA: Flow direction of the production line for base paper, flat cylindrical body, and square bottom bag B: Rear side C: Rotational conveying direction of the bottom folding drum 52 D: Lower side F: Front side L: Left side R: Right side U: Upper side W1: Width of square bottom bag 10 W2: Width of base paper 20

Claims

1. A flap unfolding device in a square bottom forming device of a bag making machine, which folds a front flap of a bottom portion of a flat cylindrical body being transported by a bottom folding drum inside out relative to a back flap, and unfolds the front flap and the back flap in a plane along the outer circumferential surface of the bottom folding drum, comprising: a pair of guide plates that guide both side portions of the flat cylindrical body along the transport direction of the bottom folding drum, and unfolds the front flap and the back flap in a plane; a pair of robots that use the pair of guide plates as end effectors; and a position and posture adjustment device that adjusts the position and posture of the pair of guide plates in three dimensional space to target position and target posture through the operation of the pair of robots.

2. The position and posture adjustment device of the present invention has an input unit having an operation operation unit that inputs information on the target positions and information on the target posture of the pair of guide plates, and a control unit that controls the operation of the pair of robots based on the information on the target positions and information on the target posture input to the input unit by operating the operation operation unit.

3. The position and posture adjustment device of the present invention performs the following operations: when information on the target position and information on the target posture are input to the input section in order to adjust the position and posture of the pair of guide plates, control to operate the pair of robots via the control section; and, in order to maintain the adjusted position and posture of the pair of guide plates, control to stop the operation of the pair of robots via the control section until new information on the target position and information on the target posture are input to the input section.

4. A flap spreading device in a square bottom forming device of a bag making machine as described in claim 2, characterized in that the input unit has an offset operation unit that inputs offset position information for positioning the pair of guide plates, which are located at the target position and in the target posture, at an offset position offset from the target position, and the control unit, by operating the offset operation unit, positions the pair of guide plates at the offset position offset from the target position through the movement of the pair of robots.

5. A flap spreading device in a square bottom forming device of a bag making machine as described in claim 2, characterized in that the position and posture adjustment device has a memory unit in which the target position information and the target posture information are stored, the input unit has an information retrieval operation unit which retrieves the target position information and the target posture information stored in the memory unit, and the control unit controls the operation of the pair of robots based on the target position information and the target posture information retrieved from the memory unit by operation of the information retrieval operation unit.

6. A flap spreading device in a square bottom forming device of a bag making machine as described in claim 5, characterized in that the input unit has an offset operation unit that inputs offset position information for positioning the pair of guide plates, which are located at the target position and in the target posture, at an offset position offset from the target position, and the control unit operates the offset operation unit to position the pair of guide plates at the offset position offset from the target position through the movement of the pair of robots.

7. The flap spreading device in the square bottom forming device of the bag making machine according to claim 1, characterized in that the pair of guide plates are attached to the pair of robots via joints and cushioning materials.

8. A flap unfolding device in a square bottom forming device of a bag making machine as described in claim 1, characterized in that it comprises: a pair of guide bars arranged between the pair of guide plates and guiding the central portion of the flat cylindrical body along the conveying direction of the bottom folding drum to unfold the front flap and the back flap in a planar manner; and a guide bar robot having the pair of guide bars as end effectors, wherein the position and posture adjustment device adjusts the position and posture of the pair of guide bars in three-dimensional space to a target position and target posture through the operation of the guide bar robot.

9. The position and posture adjustment device of the present invention has an input unit having an operation operation unit for inputting information on the target positions and information on the target posture of the pair of guide bars, and a control unit for controlling the operation of the guide bar robot based on the information on the target positions and the information on the target posture input to the input unit by operating the operation operation unit.

10. A flap unfolding device in a square bottom forming device of a bag making machine as described in claim 9, characterized in that the position and posture adjustment device performs the following controls: when information on the target position and information on the target posture are input to the input section in order to adjust the position and posture of the pair of guide bars, controls to operate the guide bar robot via the control section; and controls to stop the operation of the guide bar robot via the control section until new information on the target position and information on the target posture are input to the input section in order to maintain the adjusted position and posture of the pair of guide bars.

11. A flap unfolding device in a square bottom forming device of a bag making machine as described in claim 8, characterized in that a guide bar mounting member is attached to the guide bar robot, and a pair of the guide bars are attached to the guide bar mounting member so as to be movable in at least one of the conveying direction of the bottom folding drum and a direction intersecting the conveying direction of the bottom folding drum.

12. A flap unfolding device in a square bottom forming device of a bag making machine as described in claim 8, characterized in that a guide bar mounting member is attached to the guide bar robot via a joint and a cushioning material, and a pair of the guide bars are attached to the guide bar mounting member so as to be movable in at least one of the conveying direction of the bottom folding drum and a direction intersecting the conveying direction of the bottom folding drum.

13. A square bottom forming device for forming the bottom portion of a flat cylindrical body into a square bottom in a bag making machine, comprising: a supply device for continuously supplying the flat cylindrical bodies with intervals; a bottom folding line marking device for marking a bottom fold line and a bottom fold-in line on the bottom portion of the flat cylindrical body in a direction perpendicular to the flow direction of the production line; a bottom folding drum for transporting the flat cylindrical body in the flow direction of the production line; an opening device for opening the front flap and the back flap of the bottom portion of the flat cylindrical body; a flap unfolding device according to any one of claims 1 to 12 for folding the front flap inside out relative to the back flap along the bottom folding line and unfolding the front flap and the back flap in a plane along the outer circumferential surface of the bottom folding drum; and an adhesive application device for applying an adhesive to the front flap and the back flap unfolded in a plane. a raising device which raises the front flap and the back flap to which the adhesive has been applied along the bottom fold line; a bonding device which folds the raised front flap and the back flap along the bottom fold line and bonds them with the adhesive; and a pressing device which presses the front flap and the back flap bonded with the adhesive to form the square bottom.

14. A bag making machine for producing square bottom bags, comprising: a paper feeding device which continuously feeds out a roll of base paper in the flow direction of a production line; a flat cylinder forming device which forms a flat, cylindrical body from the base paper fed from the paper feeding device; and a square bottom forming device as described in claim 13 which forms a square bottom from the bottom portion of the flat cylinder formed by the flat cylinder forming device.

15. The bag making machine according to claim 14, further comprising a handle device for forming a handle and attaching said handle to a predetermined position on the mouth of said square bottom bag.

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