JP2021181315A - Packaging machine - Google Patents

Abstract

To provide a packaging machine capable of making a packaged article look better.SOLUTION: A packaging machine 10 holds a laminate T which is composed of newspaper P sandwiched between a film F1 pulled out from a roll R1 and a film F2 pulled out from a roll R2, conveys it with a conveyance mechanism, stops it at a predetermined position, and cuts it while welding the films F1 and F2 at an adhesive cutting section 4 upstream from the rear end of the laminate T. The packaging machine also has a controlling unit for controlling a brake so that the roll having a wound film where a shorter film is pulled out is made to suspend later than the roll having a wound film where a longer film is pulled out, after the laminate T is stopped at the predetermined position.SELECTED DRAWING: Figure 1

Description

The present invention relates to, for example, a packaging machine for packaging newspapers with a film.

A wrapping machine that wraps a newspaper with a film generally sandwiches the newspaper between the films drawn from two rolls and heat-welds the films around the newspaper. Then, the film is cut at the heat-welded portion, and the next newspaper is waited for. The roll of the film is provided to be freely rotatable, and is rotated by pulling out the film and stopped by stopping the pulling out.

The roll has a different moment of inertia during rotation depending on the remaining length of the film, that is, the size of the roll diameter. A roll with a large roll diameter is heavier than a roll with a small roll diameter and requires more time from the start of rotation until the rotation speed stabilizes, and more time from the start of braking to the stop. And.

Japanese Unexamined Patent Publication No. 8-143008

It is known that in the above-mentioned type of wrapping machine, there is a difference in the length of the film drawn from the two rolls by at least the thickness of the newspaper. As described above, if the length of the film drawn from the two rolls is different, the consumption of the film is different, and the roll diameters of the two rolls are also different. Further, such a difference in roll diameter gradually increases as the number of newspapers to be wrapped increases. As a result, the replacement times of the two rolls are different, and the packaging machine must be operated with the roll diameters always different.

When the diameters of the two rolls are different, as described above, the time required for the rolls to rotate and stop is different, and the slack of the film is varied. As a result, the seal position (welded portion) of the film deviates from the center position facing the end of the newspaper, or the film is wrinkled, resulting in poor appearance of the packaged product in which the newspaper is wrapped with the film.

The present invention has been made in view of the above points, and an object of the present invention is to provide a packaging machine capable of improving the appearance of a packaged product.

In one aspect of the packaging machine of the present invention, a laminate in which an object to be packaged is sandwiched between a first packaging material drawn from a first roll and a second packaging material drawn from a second roll is sandwiched and restrained. A transport mechanism that transports the first and second packaging materials in the drawing direction and stops them at a predetermined position, a first detecting unit that detects the withdrawal amount of the first packaging material, and a second packaging material withdrawal. The second detection unit that detects the amount, and the first packaging material and the second packaging material on the upstream side in the pulling direction from the rear end in the pulling direction of the laminate to be stopped at a predetermined position by the transport mechanism. The laminated body is started to be conveyed by the adhesive cutting portion for bonding and cutting, the first braking portion for stopping the rotation of the first roll, the second braking portion for stopping the rotation of the second roll, and the conveying mechanism. The withdrawal amount of the first and second packaging materials from the time of the operation to the stop at the predetermined position is detected via the first and second detection units, and the laminated body is stopped at the predetermined position and then withdrawn. A control unit that controls the first and second braking units so that the timing for stopping the roll with the smaller amount of packaging material is delayed from the timing for stopping the roll with the larger amount of packaging material. And have.

According to one aspect of the present invention, it is possible to provide a packaging machine capable of improving the appearance of the packaged product.

FIG. 1 is a schematic view showing a packaging machine according to an embodiment of the present invention. FIG. 2 is a block diagram of a control system that controls the operation of the packaging machine of FIG. FIG. 3 is a timing chart for explaining the operation timing of the packaging machine of FIG. FIG. 4 is a diagram showing an example of a data table used for operating control of the packaging machine of FIG. 1.

Hereinafter, the packaging machine 10 according to the embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram for explaining the structure of the packaging machine 10. FIG. 2 is a block diagram of a control system that controls the operation of the packaging machine 10. FIG. 3 is a timing chart for explaining the operation timing of the packaging machine 10. FIG. 4 is a diagram showing an example of a data table used for operating control of the packaging machine 10.

As shown in FIG. 1, the packaging machine 10 has an input port 1a for inputting a newspaper P to be packaged, and an discharge port 1b for discharging a packaged product W (not shown) in which the newspaper P is packaged with films F1 and F2. It has a housing 1 provided with. The housing 1 is formed in a substantially rectangular box shape, has a top wall 1c above in the direction of gravity, and has a bottom wall 1d below in the direction of gravity. The input port 1a extends in the direction perpendicular to the paper surface in FIG. 1 and is provided on the top wall 1c, and the discharge port 1b extends in the direction perpendicular to the paper surface in FIG. 1 and is provided on the bottom wall 1d. In the present embodiment, a newspaper P in which a plurality of newspapers are stacked and folded as an object to be packaged will be described as an example, but the object to be packaged is not limited to the newspaper P, but may be other articles such as a booklet or a flat box. There may be.

The packaging machine 10 includes a roll R1 (first roll) in which a long resin film F1 (first packaging material) is wound around a shaft S1, and a long resin film F2 (first roll) around the shaft S2. It has a roll R2 (second roll) wound around the packaging material (2). The axes S1 and S2 are extended in the direction perpendicular to the paper surface in FIG. 1, and are arranged at positions separated to the left and right by a distance that the rolls R1 and R2 do not interfere with each other. Both ends of the shafts S1 and S2 are rotatably supported with respect to the housing 1, and the rolls R1 and R2 can be freely rotated, respectively. Further, the rolls R1 and R2 are interchangeably attached to the housing 1.

The roll R1 on the left side in FIG. 1 is mounted in the housing 1 in a posture of rotating clockwise by pulling out the film F1. The roll R2 on the right side is mounted in the housing 1 in a posture of rotating counterclockwise by pulling out the film F2. The rolls R1 and R2 rotate by the action of pulling out the films F1 and F2, and even after the pulling out of the films F1 and F2 is stopped, the rolls R1 and R2 try to continue rotating for a while due to their inertia.

Two guide rollers 2a and 2b are provided on the downstream side of the insertion port 1a along the insertion direction of the newspaper P. The insertion direction of the newspaper P is the direction of gravity from top to bottom in FIG. 1, and hereinafter, this direction may be referred to as a withdrawal direction. The guide rollers 2a and 2b hang the films F1 and F2 drawn from the rolls R1 and R2, respectively, and guide them downward in FIG. The guide rollers 2a and 2b have an axis extending in a direction orthogonal to the paper surface in FIG. The guide rollers 2a and 2b are arranged near the insertion port 1a so as to be separated from each other to the left and right at a distance larger than the thickness of the newspaper P and slightly wider than the width of the insertion port 1a. The films F1 and F2 guided through between the guide rollers 2a and 2b are pulled out in the direction of gravity. The newspaper P loaded into the housing 1 via the loading port 1a is passed between the two films F1 and F2.

Guide plates 3a and 3b extending substantially parallel to the drawing direction are provided on the downstream side of the guide rollers 2a and 2b along the drawing direction of the films F1 and F2. In FIG. 1, the guide plate 3a on the left side is arranged to face the back surface opposite to the surface where the film F1 faces the passage of the newspaper P, and the guide plate 3b on the right side has the surface where the film F2 faces the passage of the newspaper P. They are arranged facing each other on the opposite back side. The guide plates 3a and 3b have a function of directing the tip of the films F1 and F2 in the drawing direction between the cutter 4a and the heater 4b of the adhesive cutting portion 4 and suppressing the fluttering of the films F1 and F2.

Further downstream of the guide plates 3a and 3b along the drawing direction of the films F1 and F2, an adhesive cutting portion 4 for adhering and cutting the two films F1 and F2 is provided. The adhesive cutting portion 4 has a cutter 4a having a blade extending in a direction orthogonal to the paper surface in FIG. 1, and a heater 4b extending in the same direction as the blade of the cutter 4a. The cutter 4a is arranged on the back surface side of the film F2 on the right side of the drawing, and the heater 4b is arranged on the back surface side of the film F1 on the left side. The heater 4b has a groove for receiving the blade of the cutter 4a. The cutter 4a and the heater 4b have a length exceeding at least the width of the films F1 and F2.

When the cutter 4a is moved to the left toward the heater 4b from the position shown in the figure, the two films F1 and F2 are sandwiched between the cutter 4a and the heater 4b and come into contact with each other, and the heat of the heater 4b causes the two films to come into contact with each other. F1 and F2 are welded. At the same time, the welded portions of the films F1 and F2 are cut by the cutter 4a at a substantially central position in the drawing direction. As a result, the rear ends of the two films F1 and F2 that have passed through the adhesive cutting portion 4 in the drawing direction are welded to each other, and the two films F1 and F2 on the upstream side of the adhesive cutting portion 4 are drawn out along the drawing direction. The tips in the direction are welded together.

A sensor 5 for detecting the passage of the newspaper P is provided on the upstream side of the adhesive cutting portion 4 and on the downstream side of the guide plates 3a and 3b along the drawing direction of the films F1 and F2. Further, a sensor 6 for detecting the passage of the newspaper P is provided on the downstream side of the adhesive cutting portion 4 along the drawing direction of the films F1 and F2. The sensors 5 and 6 are transmissive photoelectric sensors having a light emitting element and a light receiving element on both the left and right sides of the newspaper P, respectively. That is, the sensor 5 is arranged at a position where the light beam crosses the transport path of the newspaper P on the upstream side of the adhesive cutting portion 4, and the sensor 6 has the light ray on the downstream side of the adhesive cutting portion 4 along the transport path of the newspaper P. It is located across. Since the light rays of the sensors 5 and 6 pass through the films F1 and F2, it is possible to detect the passage of the newspaper P sandwiched between the films F1 and F2. The sensors 5 and 6 may be a reflective photoelectric sensor that detects the reflected light reflected by the newspaper P.

A transport mechanism 8 that holds and restrains a laminate T having a newspaper P sandwiched between two films F1 and F2 on the downstream side of the sensor 6 along the pull-out direction of the films F1 and F2, and transports the laminate T in the pull-out direction. Is placed. The transport mechanism 8 has transport units 8L and 8R having substantially the same structure on both the left and right sides of the laminated body T as shown in the drawing. The transport unit 8L on the left side of the drawing has a structure in which an endless transport belt 8c is wound around a drive roller 8a and a driven roller 8b separated from each other in the direction of gravity. The rotation axes of the drive roller 8a and the driven roller 8b extend in a direction orthogonal to the paper surface. The transport unit 8L is arranged at a position where the transport belt 8c is in contact with the surface of the laminated body T on the left side (the back surface of the film F1) and travels.

The transport unit 8R on the right side of the drawing is arranged on the opposite side of the laminate T with respect to the transport unit 8L, at a position where the transport belt 8c comes into contact with the surface of the laminate T on the right side of the drawing (the back surface of the film F2) and travels. ing. The transfer unit 8R may be connected to a drive shaft of the transfer unit 8L via a pulley or a timing belt (not shown), and is driven in synchronization with the transfer unit 8L. The traveling direction of the transport belt 8c of the transport unit 8L is a clockwise direction in FIG. 1, and the traveling direction of the transport belt 8c of the transport unit 8R is a counterclockwise direction. The packaged product W transported via the transport mechanism 8 and packaged by the films F1 and F2 is discharged from the packaging machine 10 via the discharge port 1b of the housing 1 by driving the temporarily stopped transport mechanism 8 again. Will be done.

As shown in FIG. 2, the packaging machine 10 has a control unit 20 that controls the operation of each unit.
Encoders 11a and 11b for detecting the withdrawal amounts of the films F1 and F2 drawn from the two rolls R1 and R2 are connected to the control unit 20, respectively. The encoder 11a for detecting the withdrawal amount of one film F1 functions as a first detection unit, and the encoder 11b for detecting the withdrawal amount of the other film F2 functions as a second detection unit.

The encoders 11a and 11b are attached to the rotation shafts of the rollers 9a and 9b (FIG. 1) arranged so as to be driven and rotatable by contacting the outer peripheral surfaces of the rolls R1 and R2 with the outer peripheral surfaces, respectively. The roller 9a functions as a first roller, and the roller 9b functions as a second roller. The rollers 9a and 9b also function as support members for supporting the rolls R1 and R2 from below, respectively. In other words, each of the rolls R1 and R2 is supported so that both ends of the shafts S1 and S2 can be moved up and down with respect to the housing 1, and are pressed against the corresponding rollers 9a and 9b by their own weight.

The encoders 11a and 11b have, for example, disks (not shown) fixed to the rotating shafts of the rollers 9a and 9b, respectively. The encoders 11a and 11b detect a plurality of notches provided on the entire circumference of each disk by a photoelectric sensor (not shown), and output a pulse signal in which the notches intermittently block the optical axis. That is, the encoders 11a and 11b output the drawing amount of the films F1 and F2 drawn from the rolls R1 and R2 as the number of pulses.

Further, brakes 12a and 12b for stopping the rotation of the two rolls R1 and R2 are connected to the control unit 20, respectively. The brake 12a that stops the rotation of one roll R1 functions as a first braking unit, and the brake 12b that stops the rotation of the other roll R2 functions as a second braking unit. The brakes 12a and 12b are the actuators 14a and 14b that press the brake shoes 13a and 13b, which are pressed against the rotating shafts of the rollers 9a and 9b to stop the rotation by friction, and the brake shoes 13a and 13b against the rotating shafts of the rollers 9a and 9b, respectively. To prepare for. When the brakes 12a and 12b are operated to stop the rotation of the rollers 9a and 9b, the rotation of the rolls R1 and R2 in contact with the outer peripheral surfaces of the rollers 9a and 9b is also stopped.

Further, an actuator 15 for driving the cutter 4a of the adhesive cutting portion 4 toward the heater 4b is connected to the control unit 20. Further, the control unit 20 is connected to a power supply device 17 for energizing the heater 4b of the adhesive cutting portion 4 and energizing the side heater 16. The side heater 16 seals both end edges of the two films F1 and F2 in the width direction. Further, a motor 18 for rotating the drive roller 8a of the transport mechanism 8 is connected to the control unit 20. Further, the control unit 20 is connected to a storage unit 19 that stores the operation program of the packaging machine 10 and stores the data table shown in FIG. The storage unit 19 temporarily stores the number of pulses detected via the encoders 11a and 11b.

Hereinafter, the processing operation using the above-mentioned packaging machine 10 will be described mainly with reference to FIGS. 3 and 4.

(preparation work)
First, the worker opens the cover (not shown) of the packaging machine 10, attaches the rolls R1 and R2 to predetermined positions in the housing 1, and pulls out the films F1 and F2 from the rolls R1 and R2. Then, the worker loosens the films F1 and F2 drawn from the rolls R1 and R2 above the guide rollers 2a and 2b and superimposes them on each other. After that, the worker closes the cover and turns on the power of the packaging machine 10.

(Preprocessing)
After the above-mentioned (preparatory work), when the newspaper P for pretreatment is loaded through the loading port 1a by the worker, the films F1 and F2 stacked above the guide rollers 2a and 2b are transferred to the newspaper P. It is pushed downward by the tip in the charging direction (hereinafter, simply referred to as the tip). The newspaper P introduced in this way is sent to the transport mechanism 8 together with the films F1 and F2 due to its own weight. At this time, the control unit 20 monitors the outputs of the sensors 5 and 6 and drives the motor 18 at the time when the tip of the newspaper P in the insertion direction blocks the light beam of the sensor 5 (FIG. 3; timing t1) to drive the transport mechanism. The operation of 8 is started.

The newspaper P sent to the transport mechanism 8 has films F1 and F2 stacked on both sides thereof (here, the one in this state is referred to as a laminated body T) between the two transport units 8L and 8R. The transport is started in a state of being sandwiched and restrained between the pair of transport belts 8c that have been fed and running. In this way, when the transfer mechanism 8 starts the transfer of the laminated body T, the films F1 and F2 are also pulled downward by the transfer mechanism 8 together with the newspaper P.

If the films F1 and F2 stacked during the above-mentioned (preparation work) are loosened on the upstream side of the transport mechanism 8 at the time when the transport of the laminated body T by the transport mechanism 8 is started, the films F1 and F2 The slack portion is first conveyed, and after the slack is eliminated, the films F1 and F2 are newly pulled out from the rolls R1 and R2. If there is no slack in the films F1 and F2 on the upstream side of the transfer mechanism 8 when the transfer of the laminated body T by the transfer mechanism 8 is started, the films F1 and F2 are pulled out from the rolls R1 and R2, and the rolls R1 and R2 It is rotated.

The control unit 20 is output from the encoders 11a and 11b at the time when the tip of the newspaper P included in the laminated body T is detected by the sensor 6 (timing t2) after the transfer of the laminated body T by the transport mechanism 8 is started. Start counting the number of pulses. Then, the control unit 20 ends counting the number of pulses at the time when the sensor 6 detects the rear end (hereinafter, simply referred to as the rear end) of the newspaper P in the insertion direction (timing t3), and the timing t2 to the timing t3. In the meantime, the number of pulses counted via the encoders 11a and 11b is written in the storage unit 19.

Further, the control unit 20 stops the motor 18 at the time (t3) when the rear end of the newspaper P is detected by the sensor 6, and stops the transport of the laminated body T by the transport mechanism 8. In this state, the laminated body T is held and restrained by the pair of transport belts 8c and stopped at a predetermined position. On the other hand, when the films F1 and F2 are pulled out from the rolls R1 and R2 while the laminated body T is being conveyed by the conveying mechanism 8, the rolls R1 and R2 are still due to their inertia even after the laminated body T is stopped. The films F1 and F2 continue to rotate and are sent out from the rolls R1 and R2 until the rolls R1 and R2 stop. Here, for the sake of clarity, it is assumed that the rolls R1 and R2 are rotating when the laminated body T is stopped.

The control unit 20 transports the laminated body T by the transport mechanism 8 and stops at a predetermined position (t3), and then operates the brakes 12a and 12b at a predetermined timing. That is, the control unit 20 calculates the difference in the number of pulses of the encoders 11a and 11b written in the storage unit 19 after stopping the driving of the motor 18, and the data shown in FIG. 4 stored in the storage unit 19 in advance. Get the corresponding brake timing from the table. Then, the control unit 20 operates the brakes 12a and 12b at the acquired timing to stop the rolls R1 and R2.

For example, when the number of pulses detected via the encoder 11a is 20 pulses less than the number of pulses detected via the encoder 11b, the timing for stopping the roll R1 is delayed by 10 msec from the timing for stopping the roll R2. Further, for example, when the number of pulses detected via the encoder 11b is 8 pulses less than the number of pulses detected via the encoder 11a, the timing for stopping the roll R2 is delayed by 5 msec from the timing for stopping the roll R1.

That is, in the present embodiment, the timing for stopping the roll having a small drawing amount of the film during the transport of the laminated body T is set to be later than the timing for stopping the roll having a large drawing amount. Further, in the present embodiment, the time for shifting the stop timing of the rolls R1 and R2 is changed according to the difference in the withdrawal amount of the films F1 and F2. As a result, after the laminated body T is stopped, the slack of the films F1 and F2 can be controlled to substantially the same amount on the upstream side of the transport mechanism 8. The data table of FIG. 4 is an example, and may be appropriately prepared according to the model of the packaging machine 10 and the customer's request.

After stopping the laminate T and stopping the rolls R1 and R2, the control unit 20 operates the cutter 4a of the adhesive cutting unit 4 to weld and cut the two films F1 and F2. At this time, since the two films F1 and F2 have the same slack length on the upstream side of the transport mechanism 8, the two films F1 and F2 are on the upstream side and the downstream side of the adhesive cutting portion 4, respectively. The slack of F2 can be the same length.

Further, after this, the control unit 20 drives the motor 18 to restart the transfer of the laminated body T by the transfer mechanism 8, and discharges the laminated body T through the discharge port 1b. The laminate T discharged in this way is open with the films F1 and F2 not welded on the tip side of the newspaper P. Therefore, the worker takes out only the newspaper P from the discharged laminate T and reprocesses it.

On the other hand, after discharging the laminated body T for pretreatment, as described above, the films F1 and F2 on the upstream side of the adhesive cutting portion 4 are loosened with substantially the same length, and the films F1 and F2 are drawn out. The ends on the downstream side are welded together. Therefore, the welded portion of the films F1 and F2 is located between the adhesive cutting portion 4 and the transport mechanism 8 without shifting to either the left or right side. In this state, the packaging machine 10 is in a standby state of waiting for the newspaper P to be loaded as a packaged object.

Here, in order to make the explanation easier to understand, it is assumed that the rolls R1 and R2 are rotating at the time when the transport of the laminated body T by the transport mechanism 8 is stopped (timing t3), but the above-mentioned (preparation) is assumed. When the films F1 and F2 stacked above the guide rollers 2a and 2b are largely loosened in the work), at least one of the rolls R1 and R2 is not rotating at the time when the laminated body T is stopped (t3). There is a possibility that That is, in this case, only the slack portion of the film is pulled into the transport mechanism 8 by the transport of the laminated body T, and the film is not newly pulled out from the rolls R1 and / or R2 around which the film is wound, and the roll is stopped. It will be in the same state as it was.

If both of the two rolls R1 and R2 are stopped at the time when the laminated body T is stopped, the number of pulses of the encoders 11a and 11b stored in the storage unit 19 becomes zero. In this case, it is highly possible that both the films F1 and F2 are loose on the upstream side of the transport mechanism 8. Further, when one of the two rolls R1 and R2 is stopped when the laminated body T is stopped, only the number of pulses detected via the encoder attached to the stopped roll becomes zero. In this case as well, the film pulled out from the stopped roll is likely to be slackened on the upstream side of the transport mechanism 8, and the film pulled out from the rotating roll is slackened until the roll is stopped. increase.

That is, even when at least one of the number of pulses detected via the two encoders 11a and 11b between the start and stop of the transfer of the laminated body T by the transfer mechanism 8 is zero, the transfer mechanism There is a high possibility that slack is formed in the films F1 and F2 on the upstream side of 8. Therefore, in this case, after the films F1 and F2 are welded and cut at the adhesive cutting portion 4, slack remains in the films F1 and F2 on the upstream side of the cutting position, and the welded portion does not shift to the left or right. It will be located between the portion 4 and the transport mechanism 8.

However, at the time when the transport of the laminated body T by the transport mechanism 8 is stopped, a situation may occur in which the films F1 and F2 do not loosen on the upstream side of the transport mechanism 8 very rarely. That is, this corresponds to the case where the slack of the film on the upstream side of the transport mechanism 8 at the time when the transport of the laminated body T is started disappears just when the transport of the laminated body T is stopped. In this case, the film is in a stretched state when the laminated body T is stopped, and if the film is welded and cut as it is, the film on the upstream side of the adhesive cutting portion 4 is likely to be stretched, and the newspaper P after that. It adversely affects the packaging process and may make the package product W look unattractive.

Therefore, in the present embodiment, the control unit 20 calculates the difference in the number of pulses detected via the two encoders 11a and 11b from the start to the stop of the transfer of the laminated body T by the transfer mechanism 8. Before this, it is determined whether or not at least one of the pulse numbers is zero, and if at least one of the pulse numbers is zero, each roll R1 and R2 is stopped 40 msec after stopping the laminated body T. The brakes 12a and 12b are controlled.

For example, if the number of pulses detected via the encoder 11a is zero and the number of pulses detected via the other encoder 11b is not zero when the transport of the laminated body T is stopped, the rotation of the roll R2 By setting the timing to stop the film F2 after 40 msec, the film F2 can be loosened more. As a result, after the films F1 and F2 are welded and cut at the adhesive cutting portion 4 with the film F1 stretched, the stretch of the film F1 can be eliminated by the slack of the other film F2. The adverse effect on the packaging process of the newspaper P can be reduced.

(Packaging operation)
After the above-mentioned (pretreatment), when the newspaper P as a packaged object is loaded through the loading port 1a by the worker, the tip of the newspaper P pushes the welded portions of the two films F1 and F2 downward. Push it in. The newspaper P introduced in this way is sent to the transport mechanism 8 together with the films F1 and F2 due to its own weight. At this time, the control unit 20 monitors the outputs of the sensors 5 and 6 and drives the motor 18 at the time when the tip of the newspaper P in the insertion direction blocks the light beam of the sensor 5 (FIG. 3; timing t1) to drive the transport mechanism. The operation of 8 is started.

The newspaper P fed to the transport mechanism 8 is fed between the two transport units 8L and 8R with the films F1 and F2 stacked on both sides thereof, and is fed between the pair of transport belts 8c running. Transport is started in a state of being pinched and restrained. In this way, when the transfer mechanism 8 starts the transfer of the laminated body T, the films F1 and F2 are also pulled downward by the transfer mechanism 8 together with the newspaper P. Then, by transporting the laminated body T, the films F1 and F2 are pulled out from the rolls R1 and R2, and the rolls R1 and R2 rotate.

The control unit 20 is output from the encoders 11a and 11b at the time when the tip of the newspaper P included in the laminated body T is detected by the sensor 6 (timing t2) after the transfer of the laminated body T by the transport mechanism 8 is started. Start counting the number of pulses. Then, the control unit 20 ends counting the number of pulses at the time when the rear end of the newspaper P is detected by the sensor 6 (timing t3), and counts via the encoders 11a and 11b between the timing t2 and the timing t3. The number of pulses is written in the storage unit 19.

Further, the control unit 20 stops the motor 18 at the time (t3) when the rear end of the newspaper P is detected by the sensor 6, and stops the transport of the laminated body T by the transport mechanism 8. In this state, the laminated body T is held and restrained by the pair of transport belts 8c and stopped at a predetermined position. On the other hand, the rolls R1 and R2 from which the films F1 and F2 have been pulled out while the laminated body T is being conveyed by the conveying mechanism 8 continue to rotate due to their inertia even after the laminated body T is stopped. That is, after the laminated body T is stopped, the films F1 and F2 are sent out from the rolls R1 and R2 until the rolls R1 and R2 are stopped.

The control unit 20 transports the laminated body T by the transport mechanism 8 and stops at a predetermined position (t3), and then operates the brakes 12a and 12b at a predetermined timing. That is, the control unit 20 calculates the difference in the number of pulses of the encoders 11a and 11b written in the storage unit 19 after stopping the driving of the motor 18, and the data shown in FIG. 4 stored in the storage unit 19 in advance. Get the corresponding brake timing from the table. Then, the control unit 20 operates the brakes 12a and 12b at the acquired timing to stop the rolls R1 and R2.

For example, when the number of pulses detected via the encoder 11a is 20 pulses less than the number of pulses detected via the encoder 11b, the timing for stopping the roll R1 is delayed by 10 msec from the timing for stopping the roll R2. Further, for example, when the number of pulses detected via the encoder 11b is 8 pulses less than the number of pulses detected via the encoder 11a, the timing for stopping the roll R2 is delayed by 5 msec from the timing for stopping the roll R1.

That is, in the present embodiment, the timing for stopping the roll having a small drawing amount of the film during the transport of the laminated body T is set to be later than the timing for stopping the roll having a large drawing amount. Further, in the present embodiment, the time for shifting the stop timing of the rolls R1 and R2 is changed according to the difference in the withdrawal amount of the films F1 and F2. As a result, after the laminated body T is stopped, the slack of the films F1 and F2 can be controlled to substantially the same amount on the upstream side of the transport mechanism 8.

After stopping the laminated body T and stopping the rolls R1 and R2, the control unit 20 operates the cutter 4a of the adhesive cutting portion 4, and the two sheets having the same slack length on the upstream side of the transport mechanism 8. The films F1 and F2 of the above are welded and cut. Further, after this, the control unit 20 drives the motor 18 to restart the transfer of the laminated body T by the transfer mechanism 8, and discharges the packaged product W (not shown) through the discharge port 1b.

On the other hand, after discharging the laminated body T for pretreatment, the films F1 and F2 on the upstream side of the adhesive cutting portion 4 are loosened with substantially the same length, and the end portions on the downstream side in the drawing direction of the films F1 and F2. They are in a welded state. Therefore, the welded portion of the films F1 and F2 is located between the adhesive cutting portion 4 and the transport mechanism 8 without shifting to either the left or right side. In this state, the packaging machine 10 is in a standby state waiting for the next newspaper P to be loaded.

The packaging machine 10 repeats the above operation to wrap a plurality of newspapers P with the films F1 and F2.

As described above, according to the present embodiment, even when the packaging machine 10 is operated in a state where the diameters of the rolls R1 and R2 are different, the slack of the films F1 and F2 can be uniformly controlled, and the packaging can be performed. The appearance of the product W can be improved.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications and applications are possible within the scope of the gist of the present invention. be.

For example, in the above-described embodiment, after the transport of the laminated body T by the transport mechanism 8 is stopped and the rolls R1 and R2 are stopped at appropriate timings, the cutter 4a of the adhesive cutting portion 4 is operated to operate the films F1 and F2. However, this is not limited to this, and the adhesive cutting portion 4 may be operated at a timing after stopping the transportation of the laminated body T and before stopping the rolls R1 and R2. Even in this case, the films F1 and F2 can be loosened at least on the upstream side of the adhesive cutting portion 4, and the deterioration of the packaging quality can be suppressed.

Further, in the above-described embodiment, the case where the stop timings of the rolls R1 and R2 are controlled stepwise with reference to the data table prepared in advance has been described. The rolls R1 and R2 may be stopped at the timing when the difference in the withdrawal amounts of the films F1 and F2 drawn from the rolls R1 and R2 becomes zero between the start and the stop.

Further, in the above-described embodiment, the case where the number of pulses is counted via the encoders 11a and 11b to stop and control the rolls R1 and R2 has been described, but the present invention is not limited to this, and for example, from each roll R1 and R2 to a unit time. The rolls R1 and R2 may be stopped and controlled by detecting the pulling speed of the drawn films F1 and F2.

Further, in the above-described embodiment, the vertical transport type packaging machine 10 in which the input port 1a is provided in the top wall 1c of the housing 1 and the discharge port 1b is provided in the bottom wall 1d has been described, but the present invention is not limited to this. The present invention can also be applied to a lateral transport type packaging machine in which an input port 1a is provided on one side wall of the body 1 and a discharge port 1b is provided on the other side wall facing the body 1.

1 ... Housing, 2a, 2b ... Guide roller, 3a, 3b ... Guide plate, 4 ... Adhesive cutting part, 4a ... Cutter, 4b ... Heater, 5, 6 ... Sensor, 8 ... Conveyance mechanism, 9a, 9b ... Roller, 10 ... Packaging machine, 11a, 11b ... Encoder, 12a, 12b ... Brake, 20 ... Control unit, F1, F2 ... Film, P ... Newspaper, R1, R2 ... Roll, T ... Laminate.

Claims (5)

The first and second packaging materials are restrained by sandwiching and restraining the laminate in which the object to be packaged is sandwiched between the first packaging material drawn from the first roll and the second packaging material drawn from the second roll. A transport mechanism that transports the product in the pull-out direction and stops it at a predetermined position.
A first detection unit that detects the withdrawal amount of the first packaging material, and
A second detection unit that detects the withdrawal amount of the second packaging material, and
The first packaging material and the second packaging material are adhered to each other on the upstream side in the drawing direction from the rear end in the drawing direction of the object to be packaged, which is stopped at the predetermined position by the transport mechanism. And the adhesive cutting part to cut
A first braking unit that stops the rotation of the first roll, and
A second braking unit that stops the rotation of the second roll, and
The amount of withdrawal of the first and second packaging materials from the start of transporting the laminated body to the stop at the predetermined position by the transport mechanism is detected via the first and second detection units. Then, after the laminate is stopped at the predetermined position, the timing of stopping the roll wrapped with the packaging material having the smaller withdrawal amount is later than the timing of stopping the roll with the packaging material having the larger drawing amount. A control unit that controls the first and second braking units, and a control unit that controls the first and second braking units.
Packaging machine with. The control unit is the first and second packaging materials drawn out from the first and second rolls between the start of transporting the laminated body by the transport mechanism and the stop at the predetermined position. The first and second rolls are stopped at the timing when the difference in the withdrawal amount of the above becomes zero.
The packaging machine of claim 1. The control unit operates the first and second braking units at the timing when the slack of the first and second packaging materials becomes the same on the upstream side of the transport mechanism along the withdrawal direction.
The packaging machine of claim 1. The control unit operates the first and second braking units at the timing when the slack of the first and second packaging materials becomes the same on the upstream side of the adhesive cutting portion along the withdrawal direction.
The packaging machine of claim 1. The first detection unit detects the amount of rotation of the first roller that accompanies the first roll.
The second detection unit detects the amount of rotation of the second roller that accompanies the second roll.
The packaging machine according to any one of claims 1 to 4.

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