JP2025171518A - Bag inversion device - Google Patents

Abstract

[Problem] To provide a bag inverting device capable of inverting a stacked row of packaging bags formed by partially overlapping multiple packaging bags and adjusting the length of the overlap between the overlapping packaging bags that make up the stacked row of packaging bags. [Solution] The bag inverting device 10 comprises a supply conveyor 11, an inverting section 12 with an inverting path R, and an output conveyor 13. A forward stacked row of packaging bags Cf formed on the supply conveyor by overlapping the front half of a subsequent packaging bag on the rear half of a previous packaging bag passes through the inverting path and is then inverted into a reverse stacked row of packaging bags Cr formed by overlapping the front half of a subsequent packaging bag under the rear half of the previous packaging bag. The length of the overlap between the previous and subsequent packaging bags can be adjusted by changing the running speed of the inverting belt 26 relative to the rotational speed of the inverting drum 25. [Selected Figure] Figure 4

Description

The present invention relates to a bag inversion device that inverts packaging bags when feeding them into a packaging machine.

A packaging machine that produces bag products by filling packaging bags with packaged materials is configured to perform a predetermined packaging process while moving the packaging bags along a predetermined conveying path. A bag feeder that supplies packaging bags to the conveying path has a packaging bag stocker that stacks and stocks multiple packaging bags, and a bag feeder conveyor that removes packaging bags one by one from the bottom of the packaging bags stocked in the packaging bag stocker and carries them to the bag feeder.
When the belt surface of the bag feed conveyor comes into contact with the underside of a packaging bag, that packaging bag slides against the underside of the other packaging bags stacked above it and is pulled out of the packaging bag stocker. Then, once the first packaging bag has been pulled out to a certain extent, the underside of the other packaging bag comes into contact with the belt surface of the bag feed conveyor. At this time, the other packaging bag slides against the packaging bags stacked further up the top than its bottom, so the first packaging bag and the other packaging bag are pulled out of the packaging bag stocker while still partially overlapping. In this way, multiple packaging bags, partially overlapping each other, are arranged in a row on the bag feed conveyor. Hereinafter, this is referred to as a forward-direction overlapping row of packaging bags.
In such a stack of packaging bags, the packaging bag pulled out later is stacked on top of the packaging bag that was pulled out earlier in the direction of travel of the bag feeding conveyor.Therefore, when an attempt is made to feed the earlier packaging bag to the conveying path on the packaging machine side, the earlier packaging bag is sandwiched between the belt surface of the bag feeding conveyor and the underside of the later packaging bag, so there is a risk that it will get caught on the belt surface due to friction or static electricity, or will stick to other packaging bags, thereby interfering with the operation of the bag feeding device.
Therefore, the inventors of the present application came up with the idea that by overlapping the subsequent packaging bag on the underside of the previous packaging bag, i.e., by reversing the front and back of the forward-direction overlapping row of packaging bags to form a reverse-direction overlapping row of packaging bags, it is possible to prevent problems from occurring when feeding bags.

Here, a bag inverting device that inverts a packaging bag is disclosed in Japanese Patent Application Laid-Open No. 2017-186056.
The bag inversion device is a device that inverts packed packaging bags in a stage prior to the print inspection process or the final boxing process, and is composed of a supply section equipped with a supply belt that runs continuously together with the packaging bags through an inversion area having an arc-shaped path, a conveying and holding section equipped with a holding belt that faces the supply belt in the inversion area and holds the packaging bags together with the supply belt, a tension adjustment section that adjusts the tension of the holding belt to press the holding belt against the supply belt, and an unloading section where the packaging bags are transported from the inversion area.

Japanese Patent Application Laid-Open No. 2017-186056

However, the above-mentioned bag inversion device is configured so that when packaging bags overlap, the holding belt that is clamping the packaging bags is moved relatively away from the supply belt, and the overlapping packaging bags are discharged outside the packaging process.
Therefore, when supplying packaging bags to the bag supply device, in order to save space and improve work efficiency, it is not possible to form an overlapping row of packaging bags by shortening the distance between the packaging bag that was pulled out first and the packaging bag that was pulled out later, so that they partially overlap each other.
Furthermore, the bag inverting device is configured such that the control unit uniquely determines the feed speed of the holding belt relative to the feed speed of the supply belt so that the packaging bags do not overlap.
Therefore, since the front and back of the packaging bag are simply inverted, it is not possible to shorten the distance between the first packaging bag and the second packaging bag to form a stacked row of packaging bags in which parts of the packaging bags are overlapped on top of each other, and it is not possible to adjust the length of the overlapping part where the first packaging bag and the second packaging bag overlap.

Therefore, the problem that the present invention aims to solve is to provide a bag inverting device that can invert a stacked row of packaging bags formed by partially overlapping multiple packaging bags on top of each other, and that can adjust the length of the overlapping portions between the stacked packaging bags that make up the stacked row of packaging bags.

The bag inverting device according to claim 1 includes a supply conveyor having a start end on the side of a packaging bag stocker that stores a plurality of stacked packaging bags, the supply conveyor having a supply belt that continuously pulls out packaging bags one by one from the lowest one stored in the packaging bag stocker;
a cylindrical reversing drum connected to the end of the supply conveyor and rotating at a predetermined rotation speed; and a reversing belt disposed opposite to the peripheral wall surface of the reversing drum and continuously running while being urged toward the peripheral wall surface, whereby the reversing unit sandwiches the packaging bag between the peripheral wall surface and the belt surface of the reversing belt to turn the packaging bag over;
and a carry-out conveyor having a carry-out belt that continuously carries out the packaging bags that have passed through the reversing section and been turned upside down,
The supply conveyor overlaps the front half of the packaging bag that has been pulled out from the packaging bag stocker on the rear half of the packaging bag that has been pulled out first along the traveling direction of the supply belt, thereby forming a stacked row of packaging bags in the forward direction in which the plurality of packaging bags are partially overlapped with each other and arranged in a row,
The inverting unit sandwiches the stacked row of packaging bags in the forward direction between the peripheral wall surface and the belt surface, rotates it approximately halfway around the inverting drum, and inverts it into the stacked row of packaging bags in the reverse direction in which the first half portion of the subsequent packaging bag is overlapped under the second half portion of the previous packaging bag,
The discharge conveyor is characterized in that the stack of packaging bags in the reverse direction is discharged by the discharge belt.

The bag inverting device according to claim 2 is the invention of claim 1, further comprising an inverting drum drive unit that rotates the inverting drum at a predetermined rotation speed, an inverting belt drive unit that runs the inverting belt at a predetermined belt speed, and a control unit that independently controls the inverting drum drive unit and the inverting belt drive unit,
The control unit changes the belt speed of the reversing belt driven by the reversing belt drive unit relative to the rotation speed of the reversing drum driven by the reversing drum drive unit,
The method is characterized in that the overlap length of the packaging bag at the front and the packaging bag at the rear of the packaging bag stacking row is adjusted.

The bag inverting device according to claim 3 is the invention of claim 1, further comprising a plurality of inverting rollers, each of which is made up of one inverting main roller that supports the inverting belt and at least one inverting follower roller that supports the inverting belt and is driven by the inverting main roller,
The reversing belt is characterized in that it is made up of a plurality of round belts arranged at equal intervals along the axial direction of the reversing roller.

The bag inverting device described in claim 4 is the invention described in claim 1 or claim 2, characterized in that the inverting section is provided with a tension adjustment mechanism that adjusts the tension of the inverting belt to adjust the pressure with which the stack of packaging bags is sandwiched between the inverting belt and the inverting drum.

The bag inverting device described in claim 5 is the invention described in claim 1, characterized in that the supply conveyor is provided with a feeding mechanism that feeds the packaging bags pulled out from the packaging bag stocker toward the inverting section and forms a stack of the packaging bags in the forward direction.

According to the bag inversion device of the present invention, the front half of a packaging bag that has been pulled out from a packaging bag stocker is overlapped on the rear half of the previous packaging bag that has been pulled out earlier on the supply conveyor, and multiple packaging bags that partially overlap each other are lined up in a row to form a stacked row of packaging bags in the forward direction.Then, the bags are sandwiched between an inversion drum and an inversion belt and rotated approximately halfway around the peripheral wall surface of the inversion drum, and are inverted into a stacked row of packaging bags in the reverse direction, with the front half of the subsequent packaging bag overlapping under the rear half of the previous packaging bag.
This allows a stack of packaging bags made up of a plurality of packaging bags that partially overlap each other to be continuously turned upside down so that the leading packaging bag is stacked on top of the trailing packaging bag. Therefore, when the bag feeding device feeds packaging bags to the conveyance path of the packaging machine near the end of the discharge conveyor, the bag that is located at the forefront of the stack of packaging bags and at the top of the stack of packaging bags can be fed to the conveyance path, thereby enabling the bag feeding device to smoothly transfer packaging bags.
Preferably, the belt speed of the reversing belt is controlled relatively to the rotation speed of the reversing drum to adjust the overlap length, which is the length of the overlapping portion where the previous packaging bag and the subsequent packaging bag overlap each other.
This allows the spacing between the packaging bags to be optimized to match the timing at which the bag feeding device feeds the bags to the conveying path, by packing the subsequent packaging bags against the previous packaging bags at the inversion section to increase the number of packaging bags per unit length of the stacked row of packaging bags arranged on the conveying conveyor, or by delaying the subsequent packaging bags against the previous packaging bags to reduce the number of packaging bags per unit length of the stacked row of packaging bags arranged on the conveying conveyor.
Preferably, the continuously running reversing belt is supported by a plurality of reversing rollers, each of which is made up of one reversing main roller and at least one reversing secondary roller that is driven by the reversing main roller via the reversing belt, and the reversing belt is made up of a plurality of round belts that are arranged at equal intervals along the axial direction of the reversing roller.
This makes it easier to replace the reversing belt than using a large reversing belt made up of a flat belt with a width that faces the reversing drum, and reduces the cost of parts for the flat belt.
More preferably, a tension adjusting mechanism is provided for adjusting the tension of the reversing belt, so that the pressure applied to the stack of packaging bags sandwiched between the reversing belt and the reversing drum can be adjusted.
This allows the clamping pressure to be optimized to match the thickness of the packaging bag or the thickness of the stacked rows of packaging bags, and when changing the overlap length between the leading packaging bag and the trailing packaging bag, the clamping pressure can be weakened to make it easier to adjust the position of the trailing packaging bag relative to the leading packaging bag, or the clamping pressure can be strengthened to make it less likely for the packaging bag to shift after its position relative to the leading packaging bag has been determined.
Furthermore, preferably, a feeding mechanism is provided which feeds the packaging bags drawn from the packaging bag stocker toward the inverting section and forms a stack of packaging bags in the forward direction.
This prevents the packaging bags being pulled out of the packaging bag stocker from getting stuck near the packaging bag discharge outlet of the packaging bag stocker, and also prevents the pulled packaging bags from curling up, forming a stacked row of packaging bags in the forward direction with the front half of the subsequent packaging bag overlapped on the rear half of the previous packaging bag, and making it possible to pay out the stacked row of packaging bags to the reversing section.

1 is a side view showing an outline of the configuration of a bag inverting device according to a first embodiment. FIG. 1 is an explanatory diagram showing an outline of the configuration of a bag inverting device according to a first embodiment. FIG. 1 is an explanatory diagram showing an outline of the configuration of a reversing belt and a reversing roller that supports the reversing belt that constitute the bag reversing device according to the first embodiment; FIG. 3 is an explanatory diagram showing an outline of the flow of packaging bags when the bag inverting device according to the first embodiment is operating. FIG. 4A to 4C are explanatory diagrams illustrating an outline of a process in which packaging bags inverted by the bag inverting device according to the first embodiment are fed.

An embodiment of the bag inversion device according to the present invention will be described with reference to the accompanying drawings. Figure 1 is a side view showing the outline of the configuration of the bag inversion device according to this embodiment.

As shown in FIG. 1, the bag inverting device 10 is made up of a supply conveyor 11, an inverting unit 12, a carry-out conveyor 13, and a control unit (not shown).
The supply conveyor 11 is composed of a supply belt 15 that runs from the packaging bag stocker 100 toward the reversing unit 12 and a supply belt driving unit 16 that drives the supply belt 15 .
The packaging bag stocker 100 is composed of a box body with an upper opening and a lower opening. A bundle of packaging bags formed by stacking multiple packaging bags B can be inserted through the upper opening. The starting end of a supply belt 15 is located below the lower opening. As a result, the lowest packaging bag B of the bundle of packaging bags stocked in the packaging bag stocker 100 comes into contact with the supply belt 15, and is pulled out one by one as the supply belt 15 moves.
2, the supply belt 15 is installed between a main supply rotor 17 and a secondary supply rotor 18 driven by the main supply rotor 17, and is configured so that the belt surface runs continuously from its starting end on the packaging bag stocker 100 side to its terminal end on the reversing section side. The packaging bags B at the bottom of the bundle of packaging bags at the starting end, i.e., below the opening at the bottom end of the packaging bag stocker, are pulled out one by one as the supply belt 15 runs and supplied to the reversing section 12 at the terminal end.
At this time, when the lowest packaging bag (hereinafter referred to as the "first packaging bag") that was pulled out first from the packaging bag stocker 100 is conveyed to the supply belt 15, it is stacked on top of the lowest packaging bag, and the packaging bag (hereinafter referred to as the "last packaging bag") that is pulled out later comes into contact with the belt surface and is pulled out while partially overlapping the first packaging bag. This is repeated as the supply belt 15 continues to run, and the front half of the back half of the first packaging bag is overlapped on the rear half of the first packaging bag along the direction of travel of the supply belt 15, so that a stacked row of packaging bags C is formed on the supply conveyor 11 in which multiple packaging bags are lined up in a row with portions overlapping each other. This stacked row of packaging bags C will be referred to as the forward stacked row of packaging bags Cf below.
The supply belt drive unit 16 has a supply motor (not shown) that rotates at a predetermined rotation speed, and is configured to rotate the supply main rotor 17 connected to the supply motor to run the supply belt 15 at a predetermined speed.

Preferably, a supply tensioner 19 may be provided to adjust the tension of the supply belt 15. This allows the tension on the belt surface between the start and end of the supply belt 15 to be adjusted according to the weight of the stocked packaging bags B, thereby keeping the belt surface flat.
Preferably, as shown in FIG. 1, a feeding mechanism 20 may be provided on the supply conveyor 11 before the discharge outlet of the packaging bag stocker 100.
The payout mechanism 20 has a payout rotor 21 that is biased toward the belt surface of the supply belt 15, and a payout rotor drive unit 22 that rotates the payout rotor 21 at a predetermined rotation speed.
The payout rotor 21 is configured to sandwich the packaging bag B pulled out from the packaging bag stocker 100 between the peripheral wall surface of the payout rotor 21 and the supply belt 15 with a predetermined pressure.
The payout rotor drive unit 22 has a payout motor (not shown) that rotates at a predetermined rotation speed, and is configured to rotate the payout rotor 21 connected to the payout motor at the predetermined rotation speed.
This allows the packaging bag B to be fed toward the reversing section along the traveling direction of the supply belt 15.
As described above, the stacked row Cf of packaging bags in the forward direction is formed by overlapping the rear half of a preceding packaging bag with the front half of a succeeding packaging bag in a continuous manner. Therefore, when a packaging bag B is pulled out of the packaging bag stocker 100, the front end of the succeeding packaging bag may float up or may get caught on the discharge opening of the packaging bag stocker 100 and bend backward.
In contrast, the payout rotor 21 is biased with a predetermined pressure toward the belt surface of the supply belt 15, and can therefore press the front end of the packaging bag B that is beginning to curl or that is floating up toward the supply belt 15. This makes it possible to prevent the packaging bag B drawn out from the packaging bag stocker 100 from curling up or the front end of the packaging bag B that is aligned with the traveling direction of the supply belt 15 from floating up.

As shown in FIG. 1 , the reversing unit 12 includes a reversing drum 25 and a reversing belt 26 disposed opposite to the peripheral wall surface of the reversing drum 25 .
The reversing drum 25 is composed of a cylindrical drum body and a reversing drum drive unit 27 that rotates the drum body at a predetermined rotation speed. The peripheral wall surface of the drum body is processed to prevent the packaging bags B from slipping, for example by forming irregularities on the surface or by attaching or wrapping an anti-slip material such as rubber. This allows the supplied packaging bags B to be moved and reversed without slipping.
The reversing drum driving unit 27 has a reversing drum motor (not shown) made of a servo motor. The reversing drum motor rotates at a predetermined rotation speed, and rotates the connected drum body at the same rotation speed.
The reversing drum 25 is not limited to a configuration in which only the drum body rotates, but may also be configured to have a belt wound around the drum body, and to run the belt by rotating the drum body with the reversing drum drive unit 27.

As shown in FIG. 2, the reversing belt 26 includes a plurality of reversing rollers that support the reversing belt 26, a reversing belt drive unit 28 that causes the reversing belt 26 to run continuously at a predetermined speed, and a tension adjustment mechanism 29 that adjusts the tension of the reversing belt.
The plurality of reversing rollers are composed of a reversing main roller 30 and at least one, in this embodiment, two, reversing slave rollers 31. The reversing main roller 30 is connected to a reversing belt drive unit 28. As shown in FIG. 2 , the reversing slave roller 31 supports the reversing belt 26 together with the reversing main roller 30, and is driven by the reversing main roller 30 via the reversing belt 26.
The reversing belt drive unit 28 has a reversing belt motor 32 made of a servo motor. The reversing belt motor 32 rotates at a predetermined rotation speed, causing the connected reversing main roller 30 to rotate at the same rotation speed. The reversing main roller 30, rotating at the predetermined rotation speed, causes the reversing belt 26 to run continuously at a predetermined speed.
The tension adjustment mechanism 29 is driven by the main reversing roller 30 via the reversing belt 26 and has a tension roller 33 that is arranged to be able to move toward and away from the reversing drum 25. When the tension roller 33 is moved toward the reversing drum 25, the tension of the reversing belt 26 can be loosened, and when it is moved away from the reversing drum 25, the tension of the reversing belt 26 can be increased. In this way, the tension adjustment mechanism 29 can appropriately adjust the tension of the reversing belt 26 in accordance with the thickness or flexibility of the packaging bag B or the stacked row of packaging bags Cf, and can urge the reversing belt 26 toward the peripheral wall surface of the reversing drum 25 with a predetermined pressure.

As shown in Fig. 3, the reversing belt 26 is made up of round belts arranged at equal intervals along the axial direction of the reversing rollers, which are made up of a reversing main roller 30 and a reversing slave roller 31. As shown in Fig. 3, a plurality of guide grooves 34 are formed at equal intervals in the reversing rollers, and a round belt is fitted into each of the guide grooves 34. In Fig. 3, some of the round belts are omitted in order to show the guide grooves 34, but round belts may be fitted into all of the guide grooves 34, or the round belts may be arranged at predetermined intervals, such as by fitting a round belt into every other guide groove 34.
The use of multiple round belts makes belt replacement easier than using a single wide flat belt, and the use of round belts reduces costs compared to using a flat belt. Furthermore, since the reversing belt 26 is configured to urge the packaging bags toward the peripheral wall surface of the reversing drum 25, using a round belt that has a linear portion in contact with the surface of the packaging bag rather than a flat belt that is entirely in close contact with the surface of the packaging bag makes it less likely that the belt will rub off letters, drawings, etc. printed on the packaging bag or soil the packaging bag.
The reversing belt 26 is not limited to a round belt, but may be a flat belt having a width opposite to the width of the reversing drum, or a mesh belt with holes at predetermined intervals in the flat belt, or a ribbed belt with gaps at predetermined intervals.

Here, the arc-shaped gap formed between the opposing peripheral wall surfaces of the reversing drums 25 and the reversing belts 26 is defined as a reversing path R from the supply conveyor 11 to the carry-out conveyor 13 .
2, the reversing unit 12 having the above-described configuration is configured so that the stacked row of packaging bags Cf in the forward direction can be inserted from the supply conveyor 11 side of the reversing path R. The stacked row of packaging bags Cf in the forward direction inserted into the reversing path R is urged toward the peripheral wall surface of the reversing drum 25 by the reversing belt 26, and moves along the reversing path R toward the discharge conveyor 13 side together with the rotation of the reversing drum 25 and the movement of the reversing belt 26.
2, the reverse path R is arc-shaped, and therefore, when it travels approximately halfway from the end on the supply conveyor 11 side toward the end on the discharge conveyor 13 side, the stacked row of packaging bags C sandwiched in the reverse path R is turned upside down. The upside-down stacked row of packaging bags C is formed in such a way that the front half of a subsequent packaging bag B overlaps the rear half of a previous packaging bag B, as shown in FIG. 5. When the stacked row of packaging bags C is turned upside down on the discharge conveyor, the stacked rows are stacked in the reverse direction, as if the forward stacked row of packaging bags Cf had been reversed, and this is referred to as the reverse-direction stacked row of packaging bags Cr. As shown in FIG. 5, the reverse-direction stacked row of packaging bags Cr is formed in such a way that the foremost packaging bag that has reached the end of the discharge conveyor 13 is positioned at the top of the stacked row of packaging bags Cr, and from there, the stacked rows are arranged in a row toward the reverse path R, with subsequent packaging bags overlapping below the previous packaging bag.
In this way, the reversing unit 12 can move the forward stacked row of packaging bags Cf along the reversing path R and reverse it to the backward stacked row of packaging bags Cr.

As shown in FIG. 1 , the discharge conveyor 13 is composed of a discharge belt 35 that runs from the reversing unit 12 toward the bag supply conveyor 110 , and a discharge belt drive unit 36 that drives the discharge belt 35 .
When the stacked row of packaging bags Cr in the reverse direction is handed over from the discharge conveyor 13 to the bag supply conveyor 110, as shown in Figure 5, at the end of the bag supply conveyor 110, a bag supply arm 120 equipped with a suction cup 120a at its tip adsorbs and lifts the packaging bag B, and a bag supply process is carried out in which the packaging bag B is handed over to a gripper device 130 circulating along a packaging bag transport path formed on the packaging machine side.
Here, in the reverse-direction stacked row Cr of packaging bags that are conveyed on the carry-out conveyor 13 and the bag feed conveyor 110 and reach the end of the bag feed conveyor 110, as described above, the foremost packaging bag B0 is placed at the top of the stacked row Cr of packaging bags, and the packaging bags following the packaging bag B0 are stacked on top of the following packaging bags to form a row. Therefore, unlike packaging bags lined up on the conventional bag feed conveyor 110 or a forward-direction stacked row Cf of packaging bags that are pulled out from the packaging bag stocker 100, the packaging bags can be sucked one by one from the top in the order of feeding, starting with the foremost packaging bag B0.
This prevents bag feeding problems such as the inability to properly adsorb the previous packaging bag due to resistance such as friction on the surfaces where the previous packaging bag and the subsequent packaging bag come into contact, or the weight of the subsequent packaging bag stacked on top of the previous packaging bag, during the bag feeding process of the packaging bag B in which the suction cup 120a adsorbs the area near the opening end and passes it to the gripper device 130.

The control unit is configured to separately and independently control the drive units of each unit, namely the reversing drum drive unit 27, the reversing belt drive unit 28, the supply belt drive unit 16, the discharge belt drive unit 36, and preferably the payout rotor drive unit 20.

The control unit is configured to separately and independently control the reversing drum drive unit 27 and the reversing belt drive unit 28. As a result, the rotation speed of the reversing drum 25 driven by the reversing drum drive unit 27 and the running speed of the reversing belt 26 driven by the reversing belt drive unit 28 can be changed relative to one another using the other speed as a reference. By moving the reversing drum 25 and the reversing belt 26 relative to one another, the overlapping length along the reversing path R of the leading packaging bag B and the trailing packaging bag B that form the overlapping row C of packaging bags can be changed along the reversing path R. The overlapping length is the length of the overlapping portion of the leading packaging bag and the trailing packaging bag along the reversing path R.
When the rotation speed of the reversing drum 25 and the running speed of the reversing belt 26 are set to the same speed, the overlap length of the forward stacked row of packaging bags Cf formed on the supply belt 15 does not change, and the number of packaging bags B contained per unit length is also unchanged, and the reverse stacked row of packaging bags Cr is conveyed to the conveying belt 35 side.
When the running speed of the reversing belt 26 is made relatively faster than the rotation speed of the reversing drum 25, the overlap length of the forward stacked row of packaging bags Cf formed on the supply belt 15 becomes longer, the number of packaging bags B contained per unit length increases and is reversed, and the reverse stacked row of packaging bags Cr is conveyed to the conveying belt 35 side.
When the running speed of the reversing belt 26 is slowed relatively to the rotation speed of the reversing drum 25, the overlap length of the forward stacked row of packaging bags Cf formed on the supply belt 15 becomes shorter, the number of packaging bags B contained per unit length decreases and is reversed, and the reverse stacked row of packaging bags Cr is conveyed to the conveying belt 35 side.
As described above, by adjusting the overlap length of the overlapping packaging bags while inverting them on the inversion route R, the inversion unit 12 can invert the stacked row C of packaging bags from the forward direction to the reverse direction while correcting the stacked row C of packaging bags each time to achieve the optimal overlapping state when feeding bags.
In addition, the running speed of the reversing belt 26 is not limited to being changed based on the rotational speed of the reversing drum 25 as described above, but the rotational speed of the reversing drum 25 may be changed based on the running speed of the reversing belt 26.

The control unit is also configured to control the supply belt drive unit 16 and preferably the payout rotor drive unit 20 to drive at a constant predetermined speed based on the rotation speed of the reversing drum 25.
This allows the supply belt drive unit 16 and the payout rotor drive unit 20 to transport the forward stacked row of packaging bags Cf by synchronizing the running speed of the supply belt 15 with the rotational speed of the reversing drum 25, preventing problems such as the forward stacked row of packaging bags Cf becoming clogged at the entrance of the reversing unit 12.
The control unit is configured to control the discharge belt drive unit 36 so as to drive the discharge belt drive unit 36 at a constant predetermined speed based on the running speed of the reversing belt 26 .
This allows the discharge belt drive unit 36 to transport the reverse-direction stacked row of packaging bags Cr by synchronizing the running speed of the discharge belt 35 with the running speed of the reversing belt 26, and after adjusting the overlap length, the reverse-direction stacked row of packaging bags Cr can be accepted by the discharge belt 35 and passed on to the next bag supply conveyor 110.

The method of using the bag inverting device 10 configured as described above will be explained with reference to the attached drawings, focusing on the movement of the packaging bag B.

As shown in Fig. 4, packaging bags B are stacked and stored in a packaging bag stocker 100. A supply conveyor 11 is disposed below the packaging bag stocker 100, so that when the bag inverting device 10 operates and the supply conveyor 11 starts operating, packaging bags B are successively drawn out of the packaging bag stocker 100 by a supply belt 15, starting from the lowest one in the packaging bag stocker 100.
When the lowest packaging bag B is pulled out, the second packaging bag B stacked on top of this packaging bag B comes into contact with the supply belt 15. While the area of this contact is small, that is, while a large portion of the packaging bag B overlaps with the lowest packaging bag B, the friction between the weight of the packaging bag bundle resting on top of the second packaging bag B and the third packaging bag B stacked on top of the second packaging bag B is greater than the frictional force with the supply belt 15, so the second packaging bag B does not move and only the lowest packaging bag B is pulled out.
Then, when the area of the portion of the second packaging bag B that is in contact with the supply belt 15 reaches a predetermined size, the second packaging bag B begins to move against the frictional force between the second packaging bag B and the supply belt 15 that it is in contact with, the weight of the packaging bag bundle, the frictional force between the second packaging bag B and the third packaging bag B, static electricity adhesion, etc. At this time, the rear half of the bottommost packaging bag B and the front half of the second packaging bag B overlap as shown in Figure 4 and are pulled out of the packaging bag stocker 100.
In this way, a portion of the packaging bag B that is pulled out later is superimposed on the packaging bag B that was pulled out earlier from the packaging bag stocker 100, and they are arranged in a row on the supply belt 15 to form a forward-direction overlapping row Cf of packaging bags.
Preferably, the stacked row of packaging bags Cf in the forward direction may be sandwiched between the supply belt 15 and the payout rotor 21. This prevents the following packaging bag B from floating up or rolling up relative to the preceding packaging bag B, and allows the stacked row of packaging bags Cf in the forward direction to be sent to the reversing section 12 without the front end of the packaging bag B floating up.

The forward stacked row of packaging bags Cf that has reached the inversion section 12 is first placed on the peripheral wall surface of the inversion drum 25, as shown in Figure 4, and as the inversion drum 25 rotates, it proceeds to the inversion path R formed between the peripheral wall surface of the inversion drum 25 and the inversion belt 26.
The forward stacked row of packaging bags Cf proceeding along the inversion path R is turned upside down while making approximately half a revolution along the peripheral wall surface of the inversion drum 25, and is inverted into a reverse stacked row of packaging bags Cr in which the following packaging bag B is overlapped under the preceding packaging bag B, as shown in Figure 4.
Here, when the reversing drum drive unit 27 and the reversing belt drive unit 28 are controlled so that the rotation speed of the reversing drum 25 and the running speed of the reversing belt 26 are the same, the overlap length where the latter half of the previous packaging bag B and the former half of the next packaging bag B overlap remains unchanged on the reversing path R, and the bags are reversed from the forward stacked row of packaging bags Cf to the reverse stacked row of packaging bags Cr.
Next, when the reversing drum drive unit 27 and the reversing belt drive unit 28 are controlled so that the running speed of the reversing belt 26 is faster than the rotation speed of the reversing drum 25, the front half of the subsequent packaging bag B, which is stacked on top of the previous packaging bag B, is reduced in distance from the previous packaging bag B on the reversing path R as the reversing belt 26 travels. This makes it possible to increase the overlap length and increase the number of packaging bags included per unit length of the stacked row C of packaging bags.
When the reversing drum drive unit 27 and the reversing belt drive unit 28 are controlled so that the running speed of the reversing belt 26 is slower than the rotation speed of the reversing drum 25, the front half of the subsequent packaging bag B that is stacked on top of the previous packaging bag B is delayed relative to the previous packaging bag B on the reversing path R as the reversing belt 26 runs. This makes it possible to shorten the overlap length and reduce the number of packaging bags included per unit length of the stacked row C of packaging bags.
As described above, in the forward stacked row Cf of packaging bags, the subsequent packaging bag B stacked on top of the previous packaging bag B can be reversed to the reverse stacked row Cr of packaging bags by changing the traveling speed of the reversing belt 26 relative to the rotational speed of the reversing drum 25. Note that the same effect can be obtained by changing the rotational speed of the reversing drum 25 relative to the traveling speed of the reversing belt 26.

As described above, the overlap length between the leading packaging bag B and the trailing packaging bag B in the forward stack of packaging bags Cf formed by being pulled out by the supply conveyor 11 is determined by the frictional force between the overlapping packaging bags as well as the weight of the stack of packaging bags in the packaging bag stocker 100.
When the bundle of packaging bags is large and heavy, the subsequent packaging bag B sandwiched between the bundle of packaging bags and the preceding packaging bag B becomes difficult to pull out, and the overlap length of the subsequent packaging bag B with respect to the preceding packaging bag B becomes shorter.
On the other hand, when the number of packaging bags is small and light, the packaging bag B sandwiched between the packaging bag bundle and the previous packaging bag B becomes easier to pull out, so the overlap length of the subsequent packaging bag B with respect to the previous packaging bag B becomes longer.
Based on this, for example, a counting counter that counts how many packaging bags B have been drawn out from the packing bag stack in the packing bag stocker 100, or a weight counter that measures the weight of the packing bag stack may be provided at the start end of the supply conveyor 11, and the running speed of the reversing belt 26 may be made slower or faster relative to the rotational speed of the reversing drum 25 depending on the remaining amount of packing bags, thereby adjusting the overlap length, thereby making it possible to optimally adjust the degree of overlap of the stack of packaging bags to match the fixed timing at which the bag feeding device hands over the packaging bags to the packing bag conveying path provided in the packaging machine.

An image sensor may also be installed on the supply conveyor 11 to capture images of, for example, predetermined measurement points set on the packaging bags B, and provide feedback to the control unit regarding the overlapping state of the packaging bags B pulled by the supply belt 15 from the packaging bag stocker 100, misalignment between the packaging bags B, etc. This allows the control unit to control the reversing belt drive unit 28 as needed to change the speed of the reversing belt 26 when the overlap lengths of the leading and trailing packaging bags B detected by the image sensor are different, thereby forming a stacked row Cr of packaging bags in the reverse direction on the reversing path R with a predetermined overlap length. As described below, this is effective when operating the bag feed arm 120 at high speed to increase the bag feed speed per unit time to the gripper device 130, shortening the distance between the leading and trailing packaging bags, and increasing the number of packaging bags processed per unit time in accordance with the processing timing of the bag feed arm.

The packaging bags B that have been inverted into the reverse-direction stacked row of packaging bags Cr are delivered to the discharge conveyor 13 connected to the reversing path R and transported on the discharge belt 35. Thereafter, as shown in FIG. 5, the reverse-direction stacked row of packaging bags Cr is delivered from the discharge conveyor 13 to the bag supply conveyor 110 of the bag supply device.
5, the reverse-direction stacked row Cr of packaging bags is placed on the bag feed conveyor 110, with the succeeding packaging bag B overlapping the preceding packaging bag B. When the packaging bag B0 at the head of the reverse-direction stacked row Cr reaches near the end of the bag feed conveyor 110, the vicinity of the opening of the packaging bag B0 is attracted by suction cups 120a and lifted by the bag feed arm 120 with the opening facing up. The bag is then handed over to a gripper device 130 moving on the conveyance path of the packaging machine.
In this way, the bag feeding device can feed bags to the gripper device 130 by the bag feeding arm 120 one after another, starting from the packaging bag B0 that has reached the head of the stacked row Cr of packaging bags in the reverse direction.

According to the bag inversion device 10 of this embodiment, the packaging bags stacked in the packaging bag stocker 100 are sequentially pulled out starting from the lowest packaging bag B to form a stacked row Cf of packaging bags in the forward direction, and then the top and bottom are inverted along the inversion path R to form a stacked row Cr of packaging bags in the reverse direction.
Here, the leading packaging bag B0 at the head of the stacked row of packaging bags Cr in the reverse direction is overlapped on top of the trailing packaging bag B, and as shown in Fig. 5, the entire packaging bag is exposed. Therefore, when the bag feed arm 120 lifts up the leading packaging bag B0, there is very little risk that the trailing packaging bag B will provide resistance. Therefore, after the leading packaging bag B0 is attracted to the suction cup 120a, it can be smoothly lifted up by the bag feed arm 120.

Including the conventional case in which packaging bags B are stocked one by one on the bag feed conveyor 110 without being overlapped and are then lifted in order by the bag feed arm 120, when a stack of packaging bags Cf in the forward direction is placed as is on the bag feed conveyor 110, as long as the reciprocating motion of the bag feed arm 120 is relatively slow, even if a later packaging bag B is overlapping on the foremost packaging bag B0, the packaging bags can be lifted by the bag feed arm 120 without any problems, except in special situations such as when the packaging bags B are stuck together due to static electricity or the like.
However, if the packaging efficiency per unit time of the packaging machine is increased and the gripper device 130 is configured to move at high speed on the conveying path, the reciprocating motion of the bag feed arm 120 that supplies packaging bags B to the gripper device 130 also becomes faster. In this case, if the overlap length of the stacked row of packaging bags C is set long so as to synchronize with the high-speed reciprocating motion of the bag feed arm 120 and increase the number of packaging bags B that can be picked up per unit time, a forward-direction stacked row of packaging bags Cf is formed in which the vicinity of the opening of the preceding packaging bag B is slightly exposed from the front end of the succeeding packaging bag B, and the stacked row of packaging bags Cf is formed in the opposite direction along the traveling direction of the bag feed conveyor 110 to the reverse-direction stacked row of packaging bags Cr shown in FIG. Under such circumstances, if a forward stacked row Cf of packaging bags in which a subsequent packaging bag B is overlapped on top of a previous packaging bag B is placed on the bag supply conveyor 110, there is a risk that the overlapping subsequent packaging bag B will move along with the previous packaging bag B due to static electricity, frictional force, etc. when the previous packaging bag B is lifted up.If this movement occurs, the bag supply arm 120 will attract the packaging bag B with the suction cup 120a, making it more likely that mistakes will occur in the lifting process.

In contrast, with the bag inverting device 10 according to this embodiment, as shown in FIG. 5, the overlap length between the leading packaging bag B and the trailing packaging bag B is increased, shortening the rear end of the trailing packaging bag B exposed from the leading packaging bag B. Even if the number of packaging bags B per unit distance is increased, the leading packaging bag B0 in the stacked row Cr in the reverse direction is stacked on top of the stacked row Cr, leaving the entire packaging bag exposed. This allows the bag feed arm 120 to easily pick up the leading packaging bag B0, and furthermore, the trailing packaging bag B does not interfere with the feeding of the leading packaging bag B, improving the efficiency of the bag feeding process and easily accommodating situations where the gripper device 130 is moving at high speed due to increased packaging machine speeds.

10...Bag inversion device,
11...supply conveyor, 12...reversal section, 13...discharge conveyor,
15...supply belt, 16...supply belt drive unit, 17...supply main rotor, 18...supply sub rotor, 19...supply tensioner,
20... payout mechanism, 21... payout rotor, 22... payout rotor drive unit,
25...reversing drum, 26...reversing belt, 27...reversing drum drive unit, 28...reversing belt drive unit, 29...tension adjustment mechanism,
30...reversing main rotor, 31...reversing sub rotor, 32...reversing belt motor,
33... tension roller, 34... guide groove,
35... conveying belt, 36... conveying belt drive unit,
100...packaging bag stocker,
110... bag feeding conveyor, 120... bag feeding arm, 120a... suction cup,
130... Gripper device,
B...Packaging bag, B0...First packaging bag,
C...packaging bag stacking row, Cf...forward packaging bag stacking row, Cr...reverse packaging bag stacking row,
R...Reverse route.

Claims (5)

a supply conveyor having a start end on the packaging bag stocker side that stores a plurality of stacked packaging bags and equipped with a supply belt that continuously pulls out packaging bags one by one from the lowest one stored in the packaging bag stocker;
a cylindrical reversing drum connected to the end of the supply conveyor and rotating at a predetermined rotation speed; and a reversing belt disposed opposite to the peripheral wall surface of the reversing drum and continuously running while being urged toward the peripheral wall surface, whereby the reversing unit sandwiches the packaging bag between the peripheral wall surface and the belt surface of the reversing belt to turn the packaging bag over;
and a carry-out conveyor having a carry-out belt that continuously carries out the packaging bags that have passed through the reversing section and been turned upside down,
The supply conveyor overlaps the front half of the packaging bag that has been pulled out from the packaging bag stocker on the rear half of the packaging bag that has been pulled out first along the traveling direction of the supply belt, thereby forming a stacked row of packaging bags in the forward direction in which the plurality of packaging bags are partially overlapped with each other and arranged in a row,
The inverting unit sandwiches the stacked row of packaging bags in the forward direction between the peripheral wall surface and the belt surface, rotates it approximately halfway around the inverting drum, and inverts it into the stacked row of packaging bags in the reverse direction in which the first half portion of the subsequent packaging bag is overlapped under the second half portion of the previous packaging bag,
A bag inverting device characterized in that the discharge conveyor discharges the stack of packaging bags in the reverse direction using the discharge belt. a reversing drum driving unit that rotates the reversing drum at a predetermined rotation speed, a reversing belt driving unit that runs the reversing belt at a predetermined belt speed, and a control unit that independently controls the reversing drum driving unit and the reversing belt driving unit,
The control unit changes the belt speed of the reversing belt driven by the reversing belt drive unit relative to the rotation speed of the reversing drum driven by the reversing drum drive unit,
2. The bag inverting device according to claim 1, wherein an overlap length between the leading packaging bag and the trailing packaging bag in the stacked row of packaging bags is adjustable. a plurality of reversing rollers are provided, each of which includes one reversing main roller supporting the reversing belt and at least one reversing follower roller supporting the reversing belt and driven by the reversing main roller;
2. The bag inverting device according to claim 1, wherein the inverting belts are made up of a plurality of round belts arranged at equal intervals along the axial direction of the inverting rollers. The bag inverting device according to claim 1 or 2, characterized in that the inverting section is provided with a tension adjustment mechanism that adjusts the tension of the inverting belt to adjust the pressure with which the stack of packaging bags is sandwiched between the inverting belt and the inverting drum. 2. The bag inversion device according to claim 1, wherein the supply conveyor is provided with a feeding mechanism that feeds the packaging bags drawn from the packaging bag stocker toward the inversion section and forms a stack of the packaging bags in a forward direction.