JP7589993B2 - Film Supply Device - Google Patents

Description

The present invention relates to a film supply device used in a packaging machine.

A pillow packaging machine continuously supplies a strip-shaped packaging film wound on a roll of raw material, for example, to a bag maker on the entrance side of the packaging machine body, and forms a cylindrical bag as it passes through the bag maker. Then, a center seal device arranged downstream of the bag maker seals the area where both side edges of the packaging film are overlapped after the bag maker to form a cylindrical bag. Also, a product conveying and supplying device is arranged upstream of the bag maker, and products conveyed from the product conveying and supplying device at predetermined intervals are supplied to the bag maker. As a result, when the products pass through the bag maker, they are stored at predetermined intervals in the cylindrical packaging film, and the products are conveyed together with the cylindrical packaging film. Then, an end seal device arranged on the exit side of the pillow packaging machine seals and cuts the cylindrical packaging film so as to cross the horizontal direction at predetermined intervals, thereby producing a pillow package containing the product.

As mentioned above, the supply of strip-shaped packaging film to the main body of the packaging machine is performed by supporting a roll of raw material wound into a roll so that it can rotate freely, and unwinding the strip-shaped packaging film from the raw material roll and supplying it to the main body of the packaging machine. Naturally, the supply of packaging film from one raw material roll is limited, and when all the wound packaging film has been unwound, packaging film will be supplied from another raw material roll, but there is a film supply device that automatically switches between them.

This film supply device supports multiple (usually two) raw rolls so that each can rotate freely, and connects the end of the strip of packaging film (A) unwound from one raw roll to the leading edge of packaging film (B) from the other raw roll, so that packaging film (B) is supplied to the packaging machine body in succession following packaging film (A).

For example, the revolver-type film supply device shown in Patent Document 1 has multiple rotating support shafts for mounting the original roll on a disk. A spare packaging film is set so that it fits against the packaging film from the original roll currently being supplied, and when the remaining amount of the original roll being supplied becomes low, the two packaging films are sealed, cut, and connected at an appropriate timing. Then, when the spare packaging film is connected and supplied to the packaging machine body, the disk rotates, and the rotating support shaft mounting the original roll on which the spare packaging film was wound is controlled to move to the position where the rotating support shaft mounting the original roll that had been supplying packaging film to the packaging machine body was located until then.

This allows the positional relationship between the original roll of packaging film being supplied to the packaging machine body and the original roll of film waiting as a spare to be the same, making it possible to use the same mechanism and process for connecting the spare packaging film.

This rotating support shaft is also linked to a drive motor such as a servo motor via a clutch mechanism. When the clutch mechanism is connected, it receives the rotational output of the drive motor and rotates, which causes the original roll to rotate and pay out the packaging film at a predetermined speed. Then, when the supply of packaging film to the packaging machine body is switched, the rotating support shaft to which the original roll that had been being supplied is attached disengages the clutch mechanism and becomes free. The rotating support shaft then rotates at high speed due to inertia, and the packaging film is paid out at high speed, causing slack, so the rotating support shaft is configured to apply the brakes, for example by pressing a brake pad or brake belt against it.

JP 2012-6691 A Japanese Patent Application Publication No. 9-142422

Braking devices that use brake pads and brake belts apply the brakes through mechanical contact, so the contact surface wears out over time and the braking effect decreases. Also, mechanical contact makes it difficult to achieve smooth control.

The inventors therefore discovered the use of eddy current brakes instead of conventional braking devices that use mechanical contact. However, typical eddy current brakes cannot be used as is because they are not structured to allow the bobbin shaft to move in the axial direction. That is, in film supply devices, for example, the rotating support shaft is configured to be movable in the axial direction in order to align the widthwise center of the raw roll attached to the rotating support shaft with the center of the packaging machine body or to adjust them to a specified positional relationship. In addition, there are also devices, such as the device disclosed in Patent Document 2, in which the rotating support shaft is configured to be movable in the axial direction in order to correct meandering of the packaging film.

Because the rotating support shaft is configured to be movable in the axial direction in this way, the eddy current brake cannot be applied as is, as described above. On the other hand, if the rotating support shaft is made unable to move in the axial direction in order to implement an eddy current brake, a separate device such as a meandering correction device is required. Also, for example, it becomes cumbersome to supply the packaging film so that its center in the width direction is aligned with the center of the packaging machine body.

The above-mentioned problems are described as being independent of each other, and the present invention does not necessarily have to solve all of the problems described, but it is sufficient if it can solve at least one of the problems. In addition, we intend to obtain rights to the configuration for solving this problem separately through divisional applications, amendments, etc.

In order to solve the above-mentioned problems, the film supply device of the present invention comprises a rotating support shaft that rotatably supports a raw roll on which packaging film is wound, a transport path that transports the packaging film continuously unwound from the raw roll supported by the rotating support shaft in a predetermined trajectory, a moving mechanism that moves the rotating support shaft back and forth along the axial direction, and a brake mechanism that applies a biasing force to the rotating support shaft to suppress its rotation, the brake mechanism utilizing eddy currents and configured to apply the biasing force to the rotating support shaft even when the moving mechanism has moved the rotating support shaft.

In this way, for example, if the rotating support shaft attempts to rotate at a predetermined speed or faster, a braking force based on eddy currents is applied to the rotating support shaft, slowing down the speed of the rotating support shaft or stopping its rotation. This makes it possible to prevent the packaging film from being unwound more than necessary from the original roll attached to the rotating support shaft, causing it to slacken. Furthermore, even if the rotating support shaft moves in the axial direction, eddy currents are generated and a brake can be applied. Because eddy currents are used, braking force can be applied to the rotating support shaft without contact, so deterioration over time can be minimized.

(1) Based on the above premise, the brake mechanism includes a first cylindrical body and a second cylindrical body arranged concentrically so as to overlap at least partially, the first cylindrical body is attached to the rotating support shaft and rotates therewith, and the second cylindrical body is configured to be attached to the side supporting the rotating support shaft, one of the first cylindrical body and the second cylindrical body has a plurality of permanent magnets arranged in the circumferential direction, and the other has a cylindrical portion made of an electrical conductor facing the permanent magnets, and the permanent magnets are configured to maintain a state facing the cylindrical portion even when the rotating support shaft is moved by the moving mechanism.

In this way, by appropriately setting the axial length of the cylindrical portion, even if the first cylindrical body and the second cylindrical body move relatively in the axial direction as the rotating support shaft moves in the axial direction, the permanent magnet faces the cylindrical portion (electrical conductor), and a braking force associated with eddy currents can be exerted.

In this embodiment, the first cylindrical body corresponds to the inner ring portion 52, and the second cylindrical body corresponds to the outer ring portion 51. In this manner, the first cylindrical body attached to the rotating support shaft is not limited to being placed on the inside, and the relationship between the inside and outside may be reversed. In addition, the positional relationship between the permanent magnet and the cylindrical portion (electrical conductor) may be either on the first cylindrical body side or the second cylindrical body side, or may be either on the inner ring or the outer ring.

(2) The rotation support shaft may be supported by a bearing so as to penetrate the rotor and may be configured to be reciprocally movable along the axial direction of the rotation support shaft, and the second cylindrical body may be configured to be attached to the rotor. In this way, the first cylindrical body and the second cylindrical body constituting the brake mechanism are attached to the rotation support shaft and the rotor, respectively, so that the relative rotational movement and axial movement between the first cylindrical body and the second cylindrical body can be stably performed.

(3) Based on the above premise, the brake mechanism may include a disk-shaped member made of an electrical conductor that is attached to the rotating support shaft and rotates integrally therewith, and permanent magnets that are arranged facing each other in a spaced-apart relationship on both sides of the outer edge of the disk-shaped member, and when the rotating support shaft is moved by the moving mechanism, the disk-shaped member and the permanent magnets also move in the same direction.

In this way, the brake mechanism can reduce the size of the axial force applied to the rotating support shaft, and it is possible to adjust, for example, the dimensions and shape of the disk-shaped member and the number of permanent magnets installed, thereby obtaining a large braking force.

(4) The rotating support shaft may be provided in plurality, the plurality of rotating support shafts being attached to the rotating body in a cantilevered manner, and the rotating support shaft may be configured to transmit the output from the drive motor via a clutch mechanism. In this way, for example, when the clutch is disengaged while the rotating support shaft is receiving the output from the drive motor, the rotating support shaft tends to rotate at high speed due to inertial force, but the brake mechanism of the present invention exerts a braking force according to the number of rotations, so that the rotating support shaft can be prevented from rotating at high speed in such a state as much as possible. The present invention can be effectively applied to such a film supply device. For example, in a revolver-type film supply device, the occurrence of slack in the packaging film during film splicing can be prevented.

The present invention provides one or more of the following effects. For example, the braking force on the rotating support shaft can be prevented from deteriorating over time. The rotating support shaft on which the original roll is mounted can be smoothly prevented from rotating at a speed greater than the desired speed. The original roll can be prevented from unwinding more packaging film than necessary as it rotates, causing the film to slacken.

1 is a perspective view showing a first embodiment of a film supply device according to the present invention; FIG. 2 is a perspective view showing an example of a usage state of the same. This is a front view. FIG. 5 is a cross-sectional view taken along line AA in FIG. 4. 1A is a perspective view showing a first brake mechanism, FIG. 1B is a side view thereof, FIG. 1C is a front view thereof, FIG. 1D is an exploded perspective view thereof, and FIG. FIG. 11 is a perspective view showing a second embodiment of the film supply device according to the present invention. This is a cross-sectional view. 4A is a side view showing the second brake mechanism, FIG. 4B is a front view, and FIG. 4C is an exploded perspective view.

The following describes in detail a preferred embodiment of the present invention with reference to the drawings. Note that the present invention is not to be interpreted as being limited to this embodiment, and various changes, modifications, and improvements may be made based on the knowledge of those skilled in the art without departing from the scope of the present invention.

Figures 1 to 6 show a preferred first embodiment of the film supply device according to the present invention. The film supply device 10 of this embodiment can hold two original rolls, one of which is used to supply a strip of packaging film to the packaging machine body, and the other is a spare. The supply roll and the spare roll are switched alternately, for example.

In this embodiment, a substantially disk-shaped rotating support 13 is placed in a circular opening 121 provided in the front wall 12 of a box 11 installed at a predetermined position of the packaging machine. The thickness of this rotating support 13 is made thicker (longer) than the thickness of the front wall 12. The front surface of the rotating support 13 is set in the opening 121 so that it is flush with the surface of the front wall 12. Accordingly, the back side of the rotating support 13 protrudes from the back surface of the front wall 12. A gear part 131 is provided on the peripheral surface of this protruding rotating support 13. Meanwhile, a plurality of gears meshing with the gear part 131 are arranged at a predetermined position in the box 11, and are configured to guide the rotation of the gear part 131. Furthermore, one of the plurality of gears is connected to the output of the first drive motor, becomes a drive gear, and applies a rotational force to the gear part 131 and the rotating support 13. In this way, the rotating support 13 rotates in a vertical plane parallel to the front wall 12 by receiving the rotational force from the first drive motor. The rotating support 13 receives the output of the first drive motor, rotates at an appropriate timing, and stops at any position.

The first rotating support shaft 15 and the second rotating support shaft 16 are attached to the front side of the rotating support 13 at 180 degree intervals so as to be cantilevered via the bearing portion 20. As shown in FIG. 2, the first rotating support shaft 15 and the second rotating support shaft 16 are respectively fitted with a first original roll 17 and a second original roll 18. In FIGS. 1 and 2, the first rotating support shaft 15 is located on the left side, and the packaging film 19 unwound from the first original roll 17 attached to the first rotating support shaft 15 is supplied to the packaging machine body (not shown). Then, before the first original roll 17 runs out, the operator attaches the second original roll 18 to the second rotating support shaft 16 and sets it up for connection.

The first rotating support shaft 15 has a cylindrical support shaft body 151. A pair of front and rear stopper parts 152 that can protrude from the circumferential surface are arranged on the support shaft body 151 at 120 degree intervals in the circumferential direction, and the stopper parts 152 move toward and away from each other along the axial direction by rotating the handle part 153 attached to the tip side surface on the front side of the support shaft body 151 forward and backward, and at least the stopper part 152 located on the front side is configured to protrude from the circumferential surface of the support shaft body 151 or fit inside. When the handle part 153 is rotated in a predetermined direction, the pair of front and rear stopper parts 152 move in a direction away from each other, and at least the stopper part 152 on the front side enters the support shaft body 151. This makes it possible to attach the first raw roll 17 to the support shaft body 151 from the front side of the first rotating support shaft 15. Then, when the handle portion 153 is rotated in the reverse direction with the first web roll 17 positioned appropriately, the pair of front and rear stopper portions 152 move closer to each other, and the front stopper portion 152 protrudes outward from the circumferential surface. The pair of front and rear stopper portions 152 then come into contact with both axial side surfaces of the first web roll 17, fixing the first web roll 17 in place. As a result, the first web roll 17 rotates integrally with the first rotating support shaft 15.

The first rotating support shaft 15 is supported by a bearing 20 so that its axially innermost side penetrates the bearing 20 and is rotatable. Furthermore, the innermost end of the first rotating support shaft 15 is located inside the box 11. The innermost end of the first rotating support shaft 15 is attached to a first gear 22 via a first clutch mechanism 21. This first gear 22 is linked to a second drive motor (not shown) whose position can be controlled, such as a servo motor, via a drive gear. As a result, when the clutch of the first clutch mechanism 21 is engaged (connected), the rotation output of the second drive motor is transmitted to the first rotating support shaft 15, which rotates, and the first original roll 17, which is integrated with the first rotating support shaft 15, rotates, and the strip-shaped packaging film 19 wound from the first original roll 17 is unwound at a predetermined speed. On the other hand, when the first clutch mechanism 21 is disconnected (disconnected), the rotational output of the second drive motor is not transmitted to the first rotary support shaft 15, and the first rotary support shaft 15 is free to rotate.

The second rotating support shaft 16 has a similar configuration to the first rotating support shaft 15, and includes a cylindrical support shaft body 161, three sets of stopper parts 162 that can protrude from the circumferential surface of the support shaft body 161, and a handle part 163 attached to the front side of the support shaft body 161. The second rotating support shaft 16 is supported by a bearing 20 so that the rear side of the axial direction of the second rotating support shaft 16 can freely rotate. Furthermore, the rear end of the first rotating support shaft 15 is located inside the box 11, and a second gear is attached via the second clutch mechanism. This second gear is configured to mesh with the drive gear that meshes with the first gear 22 described above. As a result, the rotation output of the second drive motor is transmitted to the second rotating support shaft 16 and it rotates on its own axis as the second clutch mechanism is turned on and off, or the transmission of the rotational force is released and it becomes free to rotate.

A first film splicing receiving member 25 and a second film splicing receiving member 26 for splicing the packaging film 19 unwound from the first raw web roll 17 and the second raw web roll 18 are attached in a cantilevered manner to predetermined positions on the front surface of the rotating support 13. The first film splicing receiving member 25 is provided below the first rotating support shaft 15 in FIG. 1 etc., that is, behind the first rotating support shaft 15 along the direction of rotation of the rotating support 13.

The first film splice receiving member 25 has the function of temporarily fixing the leading end of the packaging film wound around the first original roll 17 while the first original roll 17 is on standby, and keeping it on standby. Similarly, the second film splice receiving member 26 has the function of temporarily fixing the leading end of the packaging film 19 wound around the second original roll 18 while the second original roll 18 is on standby, and keeping it on standby. The packaging film currently being supplied moves along above the packaging film 19 temporarily fixed while on standby, and is sealed and cut by the sealing device 27 at the appropriate timing, and the packaging film 19 on standby and the packaging film 19 being supplied to the packaging machine body are spliced together, and thereafter the original roll that was on standby is switched to being supplied, and the supply of packaging film 19 continues continuously.

To perform the above operation, the first film splice receiving member 25 and the second film splice receiving member 26 have the following configuration. In Figs. 2 and 3, the first original roll 17 is being supplied, so the second film splice receiving member 26 is moving, and no packaging film is set on the first film splice receiving member 25. First, the second film splice receiving member 26 will be described. The second film splice receiving member 26 has a second supply roller 261 at a predetermined upstream position along the conveying direction of the packaging film 19, and a second standby roller 262 at a predetermined downstream position. The packaging film 19 unwound from the first original roll 17 being supplied is stretched over the second supply roller 261. The packaging film 19 stretched over the second supply roller 261 in this way is then stretched over the first free roller 31, and moves between the second supply roller 261 and the first free roller 31 in a taut state.

On the other hand, the packaging film 19 unwound from the second original roll 18 in standby is hung over the second standby roller 262, and the path of the packaging film 19 is configured to move toward the upstream side. Furthermore, a second film tip fixing part 263 is provided between the second supply roller 261 and the second standby roller 262 on the second supply roller 261 side. This second film tip fixing part 263 is for attaching and fixing the tip of the packaging film 19 unwound from the second original roll 18 for standby. For example, the tip of the packaging film 19 may be wrapped around and fixed, or the tip of the packaging film 19 may be clamped and fixed using a magnet or other fixing member. The packaging film 19, whose path has been changed to the upstream side by the second standby roller 262 in this way, is arranged with a predetermined gap directly below the supply packaging film 19 by fixing its tip with the second film tip fixing part 263. In this state, the supply and standby packaging films 19 are not in contact with each other due to a gap between them, so the packaging film 19 unwound from the first roll 17 is transported without stress and supplied to the packaging machine body. In addition, the two packaging films 19 that are placed close to each other on the second film joining receiving member 26 are hung so that their sealant surfaces face each other.

As shown in FIG. 3, a sealing device 27 is disposed above the second film splicing receiving member 26, sandwiching two sheets of packaging film 19. This sealing device 27 is fixedly installed at a predetermined position on the front wall 12 of the box 11, and is configured so that a heated sealer can move forward and backward toward the packaging film 19. The second film splicing receiving member 26 also has a receiving portion at a position opposite the sealer, and the two sheets of packaging film 19 are contacted by the approaching sealer and the receiving portion, and are sandwiched with a predetermined pressure and heat sealed. Furthermore, a cutter blade is built into the sealer, and for example, a heat-sealed sealed portion or a predetermined portion upstream of the sealed portion is cut so as to cross the width direction of the packaging film 19. As a result, the packaging film 19 supplied to the packaging machine main body is separated from the first original roll 17, and thereafter, the packaging film 19 unwound from the second original roll 18 is continuously supplied to the packaging machine main body.

The first film splice receiving member 25 also has a similar configuration to the second film splice receiving member 26. That is, the first film splice receiving member 25 has a first supply roller 251 at a predetermined position upstream along the conveying direction of the packaging film 19, and a first standby roller 252 at a predetermined position downstream. Furthermore, a first film tip fixing portion 253 is provided between the first supply roller 251 and the first standby roller 252, on the first supply roller 251 side. The function and configuration of each roller and fixing portion are the same as the corresponding members of the second film splice receiving member 26.

2 and 3, when the supply of film is switched from the first original roll 17 to the second original roll 18 as described above in a state where no packaging film is set on the first film splicing receiving member 25, a new first original roll 17 is set on the first rotating support shaft 15. Next, at an appropriate timing, the packaging film 19 is unwound from the newly set first original roll 17, and the unwound packaging film 19 is hung on the first standby roller 252 of the first film splicing receiving member 25, and its tip is attached and fixed to the first film tip fixing part 253. In this state, when the first drive motor operates and the rotating support 13 rotates counterclockwise, the positions of the second rotating support shaft 16 and the first rotating support shaft 15 reach the film setting position arranged above and below (not shown), and after the standby original roll is set, the rotating support 13 further rotates counterclockwise and switches from the position shown in FIG. 2, and the second rotating support shaft 16 reaches the supply position on the left side of the figure. As a result, the first film splice receiving member 25 reaches the position of the second film splice receiving member 26 shown in FIG. 2, and the first supply roller 251 enters below and spans the packaging film 19 being unwound from the second roll 18.

Furthermore, the first film splice receiving member 25 and the second film splice receiving member 26 each have a lever-equipped handle portion 33 on the front side. One end of a rotating shaft 34 is attached to the center of the rear side of this lever-equipped handle portion 33. Then, as shown in FIG. 5, the other end of the rotating shaft 34 penetrates the rotating support 13 and reaches the inside of the box 11. This rotating shaft 34 is supported by bearings on both side walls of the first film splice receiving member 25, which supports both ends of each roller and fixed portion, and the rotating shaft 34 rotates forward and backward integrally with the lever-equipped handle portion 33 as it rotates forward and backward.

The other end of the rotating shaft 34 (the side not attached to the lever-equipped handle portion 33) is attached to a hole 351 provided at one end of the connecting member 35. A male thread is provided on the outer peripheral surface of the other end of the rotating shaft 34, and a female thread that meshes with the male thread is provided on the inner peripheral surface of the hole 351. A bearing portion 352 is formed on the other end of the connecting member 35, and the inner side of the first rotating support shaft 15 is attached so as to pass through the bearing portion 352. The connecting member 35 and the first rotating support shaft 15 are linked by the bearing portion 352 so that rotation around the axis of the first rotating support shaft 15 is permitted, but relative movement in the axial direction is suppressed.

As a result, as the lever-equipped handle portion 33 rotates forward and backward, the connecting member 35 moves forward and backward in the axial direction, and accordingly the first rotating support shaft 15 also moves forward and backward along the axial direction. This operation therefore makes it possible to adjust the position of the first original roll 17 in the width direction, for example by aligning the center position of the first original roll 17 attached to the first rotating support shaft 15 with the center position in the width direction of the packaging machine body.

Figure 5 shows a mechanism for axially moving the first rotating support shaft 15, including the lever-equipped handle portion 33, rotating shaft 34, and connecting member 35 attached to the first film splicing receiving member 25, but the mechanism for axially moving the second rotating support shaft 16 attached to the second film splicing receiving member 26 is similar. Therefore, by rotating the lever-equipped handle portion 33 provided on the second film splicing receiving member 26 forward and backward, the second rotating support shaft 16 moves forward and backward in the axial direction.

On the other hand, a first feed roller 37 is provided at a predetermined position on the front wall 12 of the box 11 downstream of the first free roller 31, and clamps the packaging film 19 that has passed through the first free roller 31 from above and below, applying a conveying force to it, or slowing down or stopping the rotation of the first feed roller 37 while it is clamped, thereby slowing down or stopping the unwinding of the packaging film from the original roll.

Furthermore, downstream of the first feed roller 37, a tension adjustment device (dancer roller) 38 consisting of multiple rollers arranged at appropriate positions on the front wall 12 of the box 11 is arranged, and further downstream of this tension adjustment device 38, a second free roller 39 is arranged. Further downstream of this second free roller 39, a second feed roller is arranged. The packaging film 19 passes through a path determined by each of the rollers described above and is supplied to the packaging machine body.

The tension adjustment device 38 also has multiple rollers on the top and bottom, and the length of the path of the packaging film passing through the tension adjustment device 38 can be changed by raising and lowering the rollers. As a result, even if the rotation of the raw roll support shaft is temporarily stopped, the path length in the tension adjustment device 38 gradually shortens, making it possible to continue supplying the packaging film 19 to the packaging machine body.

In this embodiment, the first brake mechanism 50 is attached concentrically to a predetermined position on the first rotating support shaft 15 and the second rotating support shaft 16. The predetermined position may be, for example, close to the bearing portion 20 that rotatably attaches the rotating support shafts to the rotating support 13, and on the front side of the rotating support 13.

The first brake mechanism 50 has a cylindrical outer ring portion 51 that is open on both sides and is attached to the rotating support 13, more specifically to the bearing portion 20, and a cylindrical inner ring portion 52 that is open on both sides and can be inserted into the outer ring portion 51. A cylindrical member 53 made of an electrical conductor is attached to the inner circumferential surface of the outer ring portion 51 on the front side. The electrical conductor may be made of aluminum, for example.

The inner ring portion 52 is fixed at a predetermined position on the support shaft body 151 of the first rotating support shaft 15 and the support shaft body 161 of the second rotating support shaft 16. As a result, the inner ring portion 52 rotates integrally with the support shaft bodies 151, 161.

The outer ring portion 51 is attached and fixed to the bearing portion 20. At this time, the center of the outer ring portion 51 is aligned with the center of the bearing portion 20. Meanwhile, the inner ring portion 52 is fixed concentrically with the support shaft bodies 151, 161, which are further supported by the bearing portion 20. The inner diameter of the front side of the outer ring portion 51 is longer than the outer diameter of the rear side of the inner ring portion 52. As a result, when the inner ring portion 52 is attached to the support shaft body 151, 161 that is supported by the bearing portion 20 so that the rear side of the inner ring portion 52 is inserted into the outer ring portion 51 (see Figures 6(a) and (b)), as shown in Figure 6(c), a predetermined gap t1 is formed between the inner surface of the outer ring portion 51, i.e., the inner surface of the cylindrical member 53, and the outer surface of the inner ring portion 52, and the first rotating support shaft 15 and the second rotating support shaft 16 rotate with this gap t1 secured.

Furthermore, in this embodiment, multiple permanent magnets 54 are arranged at equal pitch in the circumferential direction on the outer peripheral surface at the rear side of the inner ring portion 52. The surfaces of the permanent magnets 54 arranged in the circumferential direction alternate between north and south poles. It is also advisable to use, for example, neodymium magnets for the permanent magnets 54.

In this way, a magnetic field is generated that connects adjacent permanent magnets 54 with different magnetic poles, and the cylindrical member 53 exists within this magnetic field. Therefore, for example, when the first rotary support shaft 15 and the second rotary support shaft 16 rotate and the inner ring portion 52 rotates relative to the outer ring portion 51, eddy currents are generated in the aluminum due to electromagnetic induction, and a biasing force is generated in a direction that suppresses rotation, applying the brakes. The braking force becomes greater the faster the rotation speed.

Therefore, for example, when switching the packaging film 19 supplied to the packaging machine body from the first original roll 17 to the second original roll 18, if the first clutch mechanism 21 is turned off and the first rotating support shaft 15 is set in a free state, it will try to rotate suddenly due to inertia, but the eddy current brake will work to prevent the first rotating support shaft 15 and therefore the first original roll 17 from rotating at high speed, and it is possible to minimize the first original roll 17 rotating due to inertia, which would cause the packaging film 19 to be unnecessarily unwound and the film to become loose.

Furthermore, in this embodiment, the axial length t2 of the cylindrical member 53 is made a predetermined distance longer than the diameter of the permanent magnet 54 or the axial length t3 of the magnetic field generating portion. The predetermined distance is made the same as or longer than the axial movement distance within the normal adjustment range of the first rotating support shaft 15 and the second rotating support shaft 16. In this way, even if the support shaft body 151 and the support shaft body 161 are moved axially to adjust the position of the first original fabric roll 17 and the second original fabric roll 18, for example, by operating the lever-equipped handle portion 33, the permanent magnet 54 faces the cylindrical member 53 even after the movement, and braking by eddy current braking can be performed.

In addition, as described above, when the clutch is disengaged, the eddy current brake can suppress unnecessary rotation of the rotating support shaft. On the other hand, when the clutch is engaged and the output of the second drive motor is transmitted to the rotating support shaft, a braking force is generated by the eddy current brake in association with the rotation of the rotating support shaft caused by the motor output, but the rotational force based on the rotational output of the second drive motor is sufficiently large, so there is no effect in suppressing rotation based on the motor output.

Figures 7 to 9 show a second embodiment of the film supply device according to the present invention. As shown in the figures, the basic configuration of the film supply device is the same as that of the first embodiment, so corresponding members are given the same reference numerals and detailed description is omitted. Also, although explanation using illustrations is omitted in the first embodiment, a second gear 24 is attached to the rear end of the second rotating support shaft 16 via a second clutch mechanism 23. This second gear 24 is linked to a second drive motor, the position of which can be controlled, such as a servo motor (not shown), via a drive gear 28. The configuration on the side of the second rotating support shaft 16 is the same as that of the first embodiment.

In this embodiment, a second brake mechanism 60 that exerts a braking force to prevent inadvertent rotation of the first rotating support shaft 15 and the second rotating support shaft 16 is disposed inside the box 11. The second brake mechanism 60 includes a disk-shaped member 61 made of an electrical conductor, and an arc-shaped member 62 that overlaps part of the outer periphery of the disk-shaped member 61. The electrical conductor may be made of aluminum, for example.

The disk-shaped member 61 is attached to the bearing portion 352 of the connecting member 35 and is configured to rotate integrally with the support shaft body 151 or the support shaft body 161 attached to the bearing portion 352.

The arc-shaped member 62 has a groove 621 extending in the circumferential direction on the inner peripheral surface side, and the outer peripheral edge of the disk-shaped member 61 is in a state of entering the groove 621. Then, permanent magnets 622 are arranged facing each other on the opposing surfaces in the groove 621. It is preferable that the magnetic poles of the opposing surfaces of the opposing permanent magnets 622 are different. In this way, the disk-shaped member 61 is arranged so as to cut the magnetic field formed between the opposing permanent magnets 622. Furthermore, the arc-shaped member 62 is fixed to the outer periphery of the connecting member 35. As a result, when the arc-shaped member 62 rotates in conjunction with the rotation of the first rotating support shaft 15 or the second rotating support shaft 16, an eddy current brake is generated according to the rotation speed.

Therefore, when the rotating support shafts rotate freely with the clutch disengaged and no output from the second drive motor, the eddy current brake applies braking force, preventing them from rotating due to inertia.

In addition, in this embodiment, both the disk-shaped member 61 and the arc-shaped member 62 that make up the second brake mechanism 60 are attached to the connecting member 35, and when the connecting member 35 moves to move the first rotating support shaft 15 or the second rotating support shaft 16 in the axial direction, the disk-shaped member 61 and the arc-shaped member 62 move together, but the relative positional relationship between the two in the fore-and-aft direction does not change, so braking can be applied in conjunction with rotation regardless of the position.

In addition, in this embodiment, the second brake mechanism 60 is a combination of a disk-shaped member 61 and an arc-shaped member 62, which allows the axial thickness to be made compact. Also, the braking force can be increased by increasing the number of permanent magnets installed.

In addition, in this embodiment, the permanent magnets are arranged in a section of the outer periphery of the disk-shaped member 61 using the arc-shaped member 62, but the arrangement position is arbitrary. For example, the permanent magnets may be arranged around the entire circumference of the disk-shaped member 61, or may be provided in multiple discontinuous sections. Also, multiple disk-shaped members 61 may be arranged in parallel. In this case, the arc-shaped member 62 may be provided for each individual disk-shaped member 61, but it is preferable to provide multiple grooves 621 extending in the circumferential direction on the inner periphery side.

In addition, as described above, when the clutch is disengaged, the eddy current brake can suppress unnecessary rotation of the rotating support shaft. On the other hand, when the clutch is engaged and the output of the second drive motor is transmitted to the rotating support shaft, a braking force is generated by the eddy current brake in association with the rotation of the rotating support shaft caused by the motor output, but the rotational force based on the rotational output of the second drive motor is sufficiently large, so there is no effect in suppressing rotation based on the motor output.

In addition, in each of the above-described embodiments, the revolver-type film supply device has two rotation support shafts, but it may have three or more.

In each of the above-mentioned embodiments, an example is described in which the device is applied to a revolver-type film supply device, but the present invention is not limited to this, and can be applied to various types of film supply devices, such as a type in which the relative position of the rotating support shaft does not change and the raw rolls that are alternately supplied are switched, and instead of applying a driving force to the first and second rotating support shafts, a feed roller that applies a conveying force to the packaging film is placed midway along the path to the packaging machine body, and the packaging film is pulled out from the raw roll.

Although various aspects of the present invention have been described above using embodiments, it should be noted that these embodiments and descriptions are not intended to limit the scope of the present invention, but are provided to aid in the understanding of the present invention. The scope of the present invention is not limited to the configurations and manufacturing methods explicitly described in the specification, but includes combinations of the various aspects of the present invention disclosed herein. Although the configurations of the present invention that are sought to be patented are specified in the appended claims, it is hereby reiterated that configurations disclosed in this specification that are not currently specified in the claims may be claimed in the future.

Reference Signs List 10: Film supply device 13: Rotating support 15: First rotating support shaft 16: Second rotating support shaft 17: First web roll 18: Second web roll 19: Packaging film 21: First clutch mechanism 22: First gear 25: First film splicing receiving member 26: Second film splicing receiving member 33: Lever-equipped handle 34: Rotating shaft 35: Connecting member 50: First brake mechanism 51: Outer ring 52: Inner ring 53: Cylindrical member 54: Permanent magnet 60: Second brake mechanism 61: Disk-shaped member 62: Arc-shaped member 622: Permanent magnet

Claims (4)

a rotation support shaft that rotatably supports a roll of packaging film around which the packaging film is wound;
a conveying path along which the packaging film continuously unwound from the original roll supported by the rotary support shaft is conveyed along a predetermined trajectory;
a moving mechanism for moving the rotary support shaft forward and backward along an axial direction;
a brake mechanism for applying a biasing force to the rotation support shaft to suppress the rotation of the rotation support shaft;
the brake mechanism utilizes eddy current and is configured to apply the biasing force to the rotation support shaft even when the moving mechanism moves the rotation support shaft ,
The brake mechanism includes a first cylindrical body and a second cylindrical body that are concentrically arranged so as to overlap at least a portion of each other,
The first cylindrical body is attached to the rotary support shaft and rotates integrally therewith, and the second cylindrical body is attached to a side supporting the rotary support shaft,
One of the first cylindrical body and the second cylindrical body has a plurality of permanent magnets arranged in a circumferential direction, and the other has a cylindrical portion made of an electric conductor so as to face the permanent magnets,
The film supply device is characterized in that the permanent magnet is configured to maintain a state facing the cylindrical portion even when the rotation support shaft is moved by the moving mechanism. the rotation support shaft is supported by a bearing so as to penetrate the rotor, and is configured to be reciprocally movable along an axial direction of the rotation support shaft,
2. The film supply device according to claim 1, wherein the second cylindrical body is configured to be attached to the rotating body. a rotation support shaft that rotatably supports a roll of packaging film around which the packaging film is wound;
a conveying path along which the packaging film continuously unwound from the original roll supported by the rotary support shaft is conveyed along a predetermined trajectory;
a moving mechanism for moving the rotary support shaft forward and backward along an axial direction;
a brake mechanism for applying a biasing force to the rotation support shaft to suppress the rotation of the rotation support shaft;
the brake mechanism utilizes eddy current and is configured to apply the biasing force to the rotation support shaft even when the moving mechanism moves the rotation support shaft ,
the brake mechanism includes a disk-shaped member made of an electric conductor attached to the rotary support shaft and rotating integrally therewith, and permanent magnets arranged on both sides of an outer periphery of the disk-shaped member in a spaced-apart relationship with each other;
The film supply device is configured so that when the rotation support shaft is moved by the moving mechanism, the disk-shaped member moves together with the permanent magnet in the same direction. The rotation support shaft is provided in plurality,
The plurality of rotation support shafts are attached to the rotor in a cantilever manner,
4. The film supply device according to claim 1, wherein the rotation support shaft is configured so that output from a drive motor is transmitted to the rotation support shaft via a clutch mechanism.

Images