JP2000296954A - Tension controller for strip member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase precision of the tension control of a strip member on a conveyance path. SOLUTION: This tension controller determines and controls the tension of a strip film 1, wherein the controller involves guide rollers 44, 45 feeding the strip film 1, a dancer roller 64 which is disposed on a feed path P1 between the guide rollers 44, 45, and converts the feed direction of the strip film 1, and on which the strip film 1 is hung so that the front area 1B and rear area 1C of a converting part 1A in a feed direction may be in substantially parallel with each other, a linear way retaining the dancer roller 64 and controlling the operating direction of the dancer roller 64 so as to be in substantially parallel with the front area 1B and rear area 1C, metal springs 55, 56 energizing the dancer roller 64 in the opposite direction to force acting on the dancer roller 64 based on the tension of the strip film 1, and a variable cam controller determining the tension of the strip film 1 based on the operating amount of the dancer roller 64.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling the tension of a belt-like member conveyed in a longitudinal direction.

[0002]

2. Description of the Related Art Generally, when a belt-shaped member wound around an unwinding machine is unwound in the longitudinal direction and supplied to the next step via a conveying roller, environmental changes on the unwinding machine side can be prevented. Alternatively, there is a possibility that the tension of the belt-shaped member supplied to the transport roller fluctuates due to a change in the environment in the next process. As a state in which such a belt-like member is conveyed and processed, a can body manufacturing process is exemplified. In the manufacturing process of the can body, a work of attaching a thermoplastic resin film (belt-like member) on which a pattern, characters, and the like are printed in advance may be performed on the outer surface of the metal can body. In such a process, if the pitch of the pattern printed on the film is different from the reference pitch, the rotation speed of the transport roller that transports the film is controlled, and the tension of the film may change. There is.

An example of the invention for controlling the tension when the belt-shaped member fed from the unwinder is supplied to the transport roller to a constant state is disclosed in Japanese Utility Model Laid-Open Publication No. 1-153233.
And Japanese Utility Model Publication No. 3-44138. The device described in Japanese Utility Model Laid-Open Publication No. 1-153233 has a pair of fixed rollers around which a band-shaped printed material (a band-shaped member) is wound, and a dancer roller disposed between the pair of fixed rollers. This dancer roller is configured to be able to swing around a support shaft,
After the belt-shaped print conveyed by one fixed roller is wrapped around the dancer roller, it is wrapped around the other fixed roller. Then, the tension of the band-shaped printed matter is determined based on the swing angle of the dancer roller that changes according to the tension of the band-shaped printed matter.

A feeding device described in Japanese Utility Model Publication No. 3-44138 discloses a bobbin on which a tape (a belt-like member) is wound, a driving roller driven by a motor, a driven roller that contacts the driving roller, The tension lever includes a tension lever rotatably supported by a support member, an angle detector for detecting a rotation angle of the tension lever, a tension roller attached to the tension lever, and a presser foot for pressing a work cloth. Then, the tape fed from the bobbin is wound around a driving roller via a driven roller. Further, the tape is fed to the presser foot via a tension roller.

During the transport of the tape, a force acts on the tension roller due to the tension of the tape, and the tension lever swings about the support shaft by this force. Then, the rotation angle of the tension lever is detected by the angle detector, and the tension of the tape is determined based on the detection result. By controlling the drive motor based on the result of this determination, the tension of the tape is adjusted.

[0006]

However, in the apparatus described in each of the above publications, the dancer roller or the tension roller moves along an arc-shaped locus as the arm or the tension lever swings about the support shaft. I do. Then, the angle formed by the band-shaped member between the front region and the rear region of the dancer roller or the tension roller fluctuates. For this reason, in order to accurately detect the tension of the belt-like member, the correlation between the swing angle (swing position) of the arm or the tension lever and the tension of the belt-like member is predicted in advance, and the tension is determined. Must.
Therefore, a huge amount of data and setting values,
Alternatively, a program including a complicated calculation formula and a processing device are required, and there is a problem that the control device becomes complicated and cost increases.

Further, since the movable guide member moves along an arc-shaped locus, the length from the support shaft of the arm or the tension lever to the dancer roller or the tension roller (in other words, the operating radius of the movable guide member), the movable guide member, and the like. Due to the change of the initial setting position, the correlation between the swing angle of the arm or the tension lever and the tension of the band-shaped member becomes unstable, and it has been difficult to stably control the tension of the band-shaped member. If the above-mentioned inconvenience occurs, there is a possibility that wrinkles or meandering of the belt-shaped member may occur.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tension control device for a belt-like member which can improve the control accuracy of the tension of the belt-like member.

[0009]

In order to achieve the above object, the invention of claim 1 conveys the belt-like member in the longitudinal direction, determines the tension of the belt-like member, and determines the result of this determination. A tension control device for the belt-like member that controls the tension of the belt-like member based on a plurality of transport mechanisms for transporting the belt-like member in a longitudinal direction, and a plurality of transport mechanisms that are disposed on a transport path between the plurality of transport mechanisms. A movable guide member around which the belt-shaped member is looped such that the transport direction of the belt-shaped member is changed, and the front region and the rear region of the converted portion of the belt-shaped member in the transport direction are substantially parallel to each other. The movable guide member is operably held in accordance with a change in the tension of the band-shaped member, and the operation direction of the movable guide member is changed to a front region of a transfer direction changing portion of the band-shaped member, and An operation direction setting mechanism for controlling the direction of movement of the band-shaped member to be in a direction substantially parallel to the rear side region thereof, and a force acting on the movable guide member in accordance with the tension of the band-shaped member. An elastic mechanism having a constant elastic coefficient for applying a direction force to the movable guide member, and a tension determining mechanism for determining the tension of the band-shaped member based on the amount of movement of the movable guide member are provided. It is assumed that.

According to the first aspect of the present invention, since the movable guide member operates in a direction substantially parallel to the belt-shaped member to be transported, the front region and the rear region of the portion of the belt-shaped member which is changed in the transport direction substantially change. Maintained in parallel. Further, a force in a direction opposite to a force acting on the movable guide member in accordance with the tension of the belt-shaped member is applied to the movable guide member from the elastic mechanism. For this reason, the tension of the belt-shaped member in the transport path between the plurality of transport mechanisms can be uniquely determined based on the operation amount of the movable guide member.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the operation direction setting mechanism has a linear guide member, and the elastic mechanism has a movable guide according to a tension of the band-shaped member. A metal spring for applying a force opposite to the force acting on the member to the movable guide member, wherein the metal spring is configured to be detachable from the guide member. Things.

According to the second aspect of the present invention, in addition to the same effect as in the first aspect, the operation of the movable guide member corresponding to the tension of the belt-shaped member is achieved by replacing the metal spring and changing the spring constant. Can be remarkable.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings. FIG. 2 is a schematic front view showing the entire configuration of a film sticking system K1 for a can body to which the present invention is applied. The film sticking system K1 for a can body includes a band-shaped film 1 wound in a roll shape. An unwinding mechanism (unwinding station) 2 for unwinding, a joining mechanism (joining station) 3 for joining the strip films 1 to each other, and a joining mechanism 3
Tension control mechanism (tension control station) 4 for controlling the tension of the strip-shaped film 1 conveyed via the belt, and meandering adjustment for adjusting the width-wise meandering of the strip-shaped film 1 conveyed via the tension control mechanism 4 Mechanism (meandering adjustment station)
5, a cutting mechanism (cutting station) 6 for cutting the band-shaped film 1 conveyed via the meandering adjusting mechanism 5 into predetermined lengths, and attaching the cut film to a cylindrical metal can body And a sticking mechanism (sticking station) 7.

The band-shaped film 1 is a film that is adhered to a metal can, and a thermoplastic resin film is used as the band-shaped film 1. In particular,
Polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, copolymerized polyester resins composed of a copolymer of polyethylene terephthalate and isophthalic acid, polyolefin resins such as polypropylene resin and modified polypropylene resin, polycarbonate resin, polystyrene resin For example, a transparent polymer resin selected from the group consisting of vinyl chloride resin, polyvinylidene chloride copolymer and the like, or a thermoplastic resin film composed of a composite of the above resins is used.

The thickness of the resin film can be determined as appropriate. For example, a resin film having a thickness of about 10 to 30 μm can be used. A printing layer and an adhesive layer are sequentially formed on one surface of the resin film. That is, decorative printing is performed on one surface of the resin film, and an adhesive layer is provided on the surface of the printed layer. For the printing, ink made of a thermosetting urethane resin is used, and printing by gravure printing, flexographic printing, or the like is performed. Incidentally, a protective coating layer containing a lubricant may be provided on the other surface of the resin film. Further, a film in which an adhesive layer is provided on one side of a resin film and a printed layer and a protective coating layer are provided on the other side may be used.

FIG. 3 is a side view in which a part of the unwinding mechanism 2 is cut away. The unwinding mechanism 2 has an electric motor 9 mounted on a frame 8. The frame 2 has a bearing 10
Is mounted, and the shaft 1 is
1 is held horizontally. A gear 12 is mounted on the shaft 11 inside the frame 8. On the other hand, a gear 14 is provided on the output shaft 13 of the electric motor 9, and the gear 14 and the gear 12 are meshed. Therefore, the shaft 1 is driven by the power of the electric motor 9.
1 can be rotated.

A holding arm 15 is fixed to an end of the shaft 11 on the outside of the frame 8. The holding arm 15 is formed in a plate shape, and a central portion in the longitudinal direction of the holding arm 15 is connected to the shaft 11. The holding arm 15 is mounted orthogonal to the shaft 11. Bearings 16 are separately attached to both ends of the holding arm 15, and the holding shaft 17 is separately supported by each bearing 16. Each holding shaft 17 can rotate (rotate) about a horizontal axis (not shown), and when the holding arm 15 rotates, each holding shaft 17 revolves around the shaft 11. Become. The band-shaped film 1 wound in a roll shape is separately mounted on each holding shaft 17.

Then, in a state where the holding arm 15 is stopped, the belt-shaped film 1 held at a low position (use position) is fed toward the joining mechanism 3 (to be in use state), while the high position (to be used). The belt-shaped film 1 held at the (standby position) enters a standby (unused) state. Further, the frame 8 is provided with a remaining amount detection sensor 20, and the remaining amount detection sensor 20 detects the remaining amount of the band-shaped film 1 in use. The signal of the remaining amount detection sensor 20 is input to a control device (not shown) that controls the electric motor 9. Then, when the remaining amount of the band-shaped film 1 in use becomes small, the electric motor 9 is driven to rotate the holding arm 15 so that the band-shaped film 1 in the standby position is moved to the use position. It is.

At both ends of the holding arm 15, powder brakes (manufactured by Shinko Electric Co., Ltd.) 18 are provided. Each of the powder brakes 18 is provided with a corresponding one of the holding shafts 17 that rotates.
This is for applying a braking force to the vehicle. The powder brake 18 includes a fixed member (not shown) surrounding the periphery of the holding shaft 17, a magnetic powder interposed in a gap between the holding shaft 17 and the fixed member, and an exciting coil provided on the fixed member. (Not shown). When a current is applied to the excitation coil, a magnetic field is formed to generate a coupling force between the magnetic powders, and the coupling force becomes a frictional resistance to apply a braking force to the holding shaft 17. As shown in FIG. 2, the holding arm 15 has a holding rod 18A projecting in the opposite direction to the plane direction of the holding arm 15.
Is attached. A holding roller 19 is rotatably attached to the free end of each holding rod 18A. The belt-shaped film 1 unwound from the unwinding mechanism 2 is wrapped around the pressing roller 19.

As shown in FIG. 2, the joining mechanism 3 includes a splice arm 23 rotatable about a support shaft 22 provided on a base plate 21 and a base plate 21.
And a cylinder mechanism 24 provided on the side. The support shaft 22 is disposed horizontally and has a cylinder mechanism 24.
Thereby, the splice arm 23 operates within a predetermined angle range around the support shaft 22. The free end of the splice arm 23 is located below the belt-shaped film 1 at the standby position.

A roller 25 is provided on the support shaft 22 side of the splice arm 23, and a roller 26 is provided on the free end side of the splice arm 23. The roller 26 is provided with a cutter (not shown) for cutting the strip-shaped film being fed in the width direction after the strip-shaped film being fed and the strip-shaped film waiting are adhered. Further, a cylinder mechanism 29 for moving the roller 26 in the longitudinal direction of the splice arm 23 is provided. Roller 25 and roller 26
Is provided with another roller 27, and a cylinder mechanism 28 for moving the roller 27 in the longitudinal direction of the splice arm 23 is provided. Then, the belt-shaped film 1 wrapped around the roller 19 is
It is wrapped around the roller 25 via 6, 27.

FIG. 1 is a front view in which a part of the tension control mechanism 4 is broken, FIG. 4 is a plan view of the tension control mechanism 4, and FIG. 5 is a side view of the tension control mechanism 4. The tension control mechanism 4 has a plate-shaped block 40, and the block 40 and the base plate 21 are arranged in parallel. A cylindrical spacer 41 is interposed between the block 40 and the base plate 21, and a screw member 42 inserted into the spacer 41
Thus, the block 40 and the base plate 21 are fixed.

At the end of the block 40 on the side of the meandering adjustment mechanism 5, a pair of shafts 43 are provided horizontally and parallel to each other. One end of each shaft 43 is fixed to the block 40 side by a screw member 44. That is, each shaft 43 is cantilevered. Each shaft 43 projects in the thickness direction of the block 40 and toward the front side. Also, in each shaft 43,
Guide rollers 44 and 45 are rotatably mounted.

The side of the shaft 43 on the front surface of the block 40 and the end on the unwinding mechanism 2 side
The two shaft holders 46 and 47 are fixed by a screw member 48. And two shaft holders 4
6, 47 hold both ends of the shaft 49. The shaft 49 is held horizontally and parallel to the block 40, and the shaft 49 and the shaft holders 46 and 47 are fixed by set screws 50.

A rack base 51 is attached to the shaft 49. A shaft hole 52 penetrating in the horizontal direction is formed in the rack base 51, and the shaft hole 52 is formed in the shaft hole 52.
9 has been inserted. Rack base 51 facing shaft hole 52
Is formed with a flange 53 on its inner peripheral surface. Between the shaft holder 46 and the shaft holder 47 in the block 40, there is provided a horizontally extending linear way (track of a linear motion guide system) 58. Then, the rack base 51 is connected to the linear way 5 via the slider 59.
8 so as to be movable.

Guide roll 4 on outer periphery of shaft 49
An annular washer 54 is mounted between the shaft holder 46 on the 4, 45 side and the flange 53. This washer 5
A metal spring, specifically, a compression coil spring 55 is provided between the shaft holder 4 and the shaft holder 46. A metal spring, specifically, a compression coil spring 56 is provided between the washer 54 and the flange 53.
Further, a metal spring, specifically, a compression coil spring 57 is provided between the shaft holder 47 and the flange 53 on the unwinding mechanism 2 side. Each of the compression coil springs 55, 56, 57 has a shaft 49.
It is attached to the outer periphery of. In other words, the compression coil springs 55, 56, 57 are arranged in series in the length direction.

Here, the compression coil spring 55 and the compression coil spring 56 each have a length of 15
It is set to 0 mm and the winding diameter is set to 20 mm. The spring constants of the compression coil spring 55 and the compression coil spring 56 are both set to 0.06 kg / mm. Further, the spring constant of the compression coil spring 57 is set to 0.03 kg / mm, which is １ ／ of the spring constant of the compression coil spring 55 or 56. Therefore, the rack base 51 is urged (pressed) toward the shaft holder 47 by the elastic force of the compression coil springs 55 and 56. In other words, a biasing force based on a constant elastic coefficient (spring constant) is applied to the rack base 51 by the compression coil springs 55 and 56. On the other hand, the compression coil spring 57 has an elastic force for urging the rack base 51 toward the shaft holder 46, and this compression coil spring 5
Reference numeral 7 functions as a shock absorber for preventing the rack base 51 and the shaft holder 47 from contacting each other.

At the upper end of the rack base 51, a bar-shaped rack member 60 is horizontally fixed by a screw member 61. On the upper edge of this rack member 60, along the longitudinal direction,
A rack 62 made of resin is attached. A shaft 63 is fixed to the front side of the rack base 51, and the shaft 63 projects horizontally and in parallel with the shaft 43. That is, the shaft 63 is fixed cantilevered. A dancer roller 64 is rotatably attached to the shaft 63. And dancer roller 6
The set height of 4 is set between the guide roller 44 and the guide roller 45. The outer diameter of the dancer roller 64 is
The distance between the guide roller 44 and the guide roller 45 is set to be substantially the same.

With the above configuration, as shown in FIG. 2, the belt-shaped film 1 wrapped around the guide roller 44 via the roller 25 is wrapped around the dancer roller 64 to be changed in direction into a substantially U-shape (turned back). At the same time, and is hung around the guide roller 45. In this way, the transport path (pass line) P1 of the strip film 1 is formed between the guide roller 44 and the guide roller 45. When a predetermined tension is applied to the belt-like film 1 in the transport path P1 of the belt-like film 1, the front (entrance side) region 1B of the direction changing portion 1A of the belt-like film 1 is separated from the dancer roller 64, The rear (exit side) region 1C of the direction changing portion 1A of the strip film 1 is in a state parallel to each other. In other words, the front region 1 of the strip film 1
B and the rear area 1C are both in a horizontal state. Therefore, the linear way 58 and the shaft 49
And a front region 1B and a rear region 1C of the strip film 1.
And become parallel.

A variable cam plate 65 is fixed to the upper side of the block 40 by a screw member 66. Further, as shown in FIG. 4, a spacer 70 is interposed between the VARICAM plate 65 and the block 40. The VARICAM plate 65 has VARICAM 6
7 is attached. The VARICAM 67 is for indirectly detecting the horizontal position of the dancer roller 64. The VARICAM 67 includes a rotor 68, a stator (not shown) provided around the rotor 68 and around which a coil is wound, and a multi-rotation type angle detector (not shown) for detecting the rotation angle of the rotor 68. ) And a pinion gear 69 attached to the rotor 68. The module of the pinion gear 69 is set to 1.5.

The pinion gear 69 is meshed with the rack 62. For this reason, when the rack base 51 moves horizontally along the linear way 58, the pinion gear 69
And the rotor 68 rotates. By using such a gear transmission mechanism, the linear movement of the rack base 51 is
The rotation is reliably converted to the rotation of the roller 68. Then, the rotation angle of the rotor 68 is detected based on a differential change in the variable magnetic resistance caused by energizing the coil.

FIG. 6 is a block diagram showing a control circuit of the tension control mechanism 4 and the powder brake 18. A detection signal output from the angle detection unit of the VARICAM 67 is input to the VARICAM controller 71. And VARICAM 67
, The horizontal position of the rack base 51, in other words, the dancer roller 64 and the guide roller 4
The relative position with respect to 4, 45 is calculated. Based on the calculation result, the actual tension of the strip film 1 supplied to the guide roller 45 via the dancer roller 64 is determined.
More specifically, by comprehensively determining the correspondence between the tension applied to the band-shaped film 1 and the compression springs 55, 56, 57, the band-shaped film 1 is moved based on the horizontal position of the dancer roller 64. The tension can be estimated proportionally. Therefore, the VARICAM controller 71 includes:
The horizontal position of the dancer roller 64 and the band film 1
The data obtained by experimentally determining the relationship with the tension of the object is stored in advance.

On the other hand, in the VARICAM controller 71, a target value of the tension of the belt-like film 1 supplied to the guide roller 45 via the dancer roller 64 is set in advance.
The VARICAM controller 71 is an arithmetic circuit that compares the target tension with the detected tension, and turns on / off an output signal according to the comparison result. The electronic control unit 72 is for performing sequence control of the powder brake 18 based on a signal input from the VARICAM controller 71 with preset contents. The electronic control unit 72 includes an input / output interface, an arithmetic processing unit (CPU or MPU), and a storage device (ROM).
And RAM).

In the electronic control unit 72, a known P operation including a proportional operation, an integral operation, and a differential operation is performed.
ID control is performed. Further, the PID control signal output from the electronic control unit 72 is processed by the D / A converter 73, and the voltage applied from the power supply (DC constant voltage power supply) 74 to the powder brake 18 is controlled. As a result, the braking force on the holding shaft 17 holding the in-use strip film 1 is controlled, and the supply state of the strip film 1 is controlled. Specifically, the holding shaft 1
7, the feed speed (in other words, the feed amount) of the band-shaped film 1 is controlled. In the power supply 74, the braking of the powder brake 18 is released at a voltage of zero volt, the braking force of the powder brake 18 is maximized by a voltage of 24 volts, and the rotation of the holding shaft 17 is completely stopped. Such a variable voltage type is used.

On the other hand, the meandering adjustment mechanism 5 is provided on the base plate 21. The meandering adjustment mechanism 5 is configured in the same manner as this known adjustment mechanism. The meandering adjustment mechanism 5 includes rollers 75 and 76 arranged at substantially the same height.
And rollers 77 and 78 arranged at a position lower than the rollers 75 and 76 and at the same height as each other. The roller 75 is arranged near the guide roller 45, and the roller 77 is arranged below the roller 75. Also,
The roller 76 is disposed on the cutting mechanism 6 side, and a roller 78 is disposed below the roller 76. Then, the belt-shaped film 1 wrapped around the guide roller 45 is wrapped around the roller 77 via the roller 75, and then wrapped around the roller 76 via the roller 78.

The cutting mechanism 6 has a plurality of rollers 79, 80, 81 mounted on the base plate 21. In addition, the cutting mechanism 6 includes a drive roller 82 that transports the band-shaped film 1 via the rollers 79, 80, and 81 to a subsequent process. Further, a press roller 84 facing the drive roller 82 is provided, and a cylinder mechanism 85 for controlling a relative position between the press roller 84 and the drive roller 82 is provided. The strip film 1 is transported.

Further, a cutting blade 86 and a cutter roller 87 are provided downstream of the drive roller 82 and the pressing roller 84 in the transport direction of the strip film 1. The cutting blade 86 and the cutter roller 87 are for obtaining a film sheet (not shown) by cutting the band-shaped film 1 having passed between the drive roller 82 and the pressing roller 84.

The sticking mechanism 7 has a film holding drum 89 which rotates counterclockwise in FIG. 2 around a support shaft 88 on the base plate 21 side. An intake hole (not shown) is formed on the outer peripheral surface of the film holding drum 89, and the cut film sheet is transferred to the film holding drum 8
9 allows vacuum suction.

The sticking mechanism 7 has a rotating turret 9 which rotates clockwise in FIG. 2 around a rotating shaft (not shown).
Has zero. A plurality of mandrels 91 are formed on one side surface of the rotating turret 90 along the circumferential direction. The mandrel 91 is formed in a cylindrical shape, and its axis is set in the horizontal direction. This mandrel 9
1 holds a metal can (not shown). Further, a plurality of holding blocks 92 are formed on the inner peripheral side of each mandrel 91 in the rotating turret 90.

A moving mechanism (not shown) for moving each mandrel 91 in the radial direction of the rotating turret 90 is provided. Specifically, the mandrel 91 approaching the film holding drum 89 with the rotation of the rotating turret 90 is moved along a locus along the outer peripheral shape of the film holding drum 89, and then the rotating turret 9 is moved.
With the rotation of 0, the mandrel 91 is moved away from the film holding drum 89. Further, a mandrel rotating mechanism (not shown) for rotating the mandrel 91 clockwise in FIG. 2 when the mandrel 91 moves in an arc shape along the outer peripheral surface shape of the film holding drum 89 is provided. Furthermore, each mandrel 91
Is provided with a heating device (not shown) for heating the substrate by means such as high-frequency induction heating or heater heating.

Here, the correspondence between the configuration of the above embodiment and the configuration of the present invention will be described. The film sticking system K1 for a can body corresponds to the tension control device for the band-shaped member according to the present invention, the band-shaped film 1 corresponds to the band-shaped member according to the present invention, and the guide rollers 44 and 45 correspond to the transport mechanism according to the present invention. The dancer roller 64 corresponds to the movable guide member of the present invention. The linear way 58, the shaft 49, the slider 59, the rack base 51, and the shaft 63 correspond to the operation direction setting mechanism of the present invention.
5 and 56 correspond to the elastic mechanism of the present invention.
7, the variable cam controller 71 and the electronic control unit 72 correspond to a tension determining mechanism, and the shaft 49 corresponds to a guide member of the present invention.

Next, the operation of the embodiment shown in FIGS. 1 to 6 will be described. The belt-shaped film 1 mounted on the holding shaft 17 at the use position is wound around a roller 25 via a pressing roller 19, a roller 26 and a roller 27. Further, the belt-shaped film 1 is wound around the guide roller 44 and also wound around the dancer roller 64,
Then, it is wrapped around the guide roller 45. The belt-shaped film 1 is wound around rollers 75, 77, 78 and 76, and further wound around rollers 79, 80 and 81. Then, the strip film 1 enters between the drive roller 82 and the press roller 84, and the strip film 1 is transported (pulled) in the longitudinal direction by the pinching force between the drive roller 82 and the press roller 84, and is held by the holding shaft 17. The strip-shaped film 1 is continuously fed out. The holding shaft 17 rotates with the feeding operation of the strip film 1. When the strip film 1 is cut by the cutter roller 87 and the cutting blade 86, the cutting is performed after a part of the leading end in the transport direction is vacuum-adsorbed by the sticking roller 89. The cut film sheet is conveyed to the rotating turret 90 side while being held by the sticking roller 89 by rotating the sticking roller 89 counterclockwise as indicated by an arrow in FIG.

On the other hand, a can body is held in each mandrel 91, and the can body is heated by the heating device via each mandrel 91. Then, as the rotating turret 90 rotates clockwise as indicated by the arrow in FIG. 2, the can bodies held by each mandrel 91 are sequentially transferred in a direction approaching the sticking roller 90.

When the film sheet comes into contact with the can body, the heat of the can body causes the film sheet to be thermally bonded to the can body via an adhesive layer, and the mandrel 91 and the can body move clockwise in FIG. By rotating, the film sheet is sequentially adhered to the outer periphery of the can body. In this way, the can body to which the film sheet is adhered is transported in a direction away from the attaching roller 89 with the rotation of the rotating turret 90, and is removed from the mandrel 91. In other words, the mandrel 91 holding the can moves in a locus like an arrow indicated by a dashed line in FIG. Hereinafter, an operation of cutting the strip-shaped film 1, an operation of vacuum-sucking the cut film sheet by the sticking roller 89, and a can holding the film sheet vacuum-sucked by the sticking roller 89 by the mandrel 91 The operation of sticking to the body is repeated.

On the other hand, by repeating the above operation, the remaining amount of the band-shaped film 1 of the holding shaft 17 at the use position decreases. The remaining amount of the band-shaped film 1 is detected by the remaining amount detection sensor 20, and when the remaining amount of the band-shaped film 1 decreases to a predetermined amount or less, the low-speed operation mode (the drive roller 82).
In this case, the rotation speed of the belt film 1 is reduced, so that the transport speed of the strip film 1 is reduced.
2, the splice arm 23 rotates counterclockwise by a predetermined angle about the support shaft 22 in FIG.

In parallel with this operation, a pitch sensor (not shown) detects a pitch mark of the strip film 1, and the cylinder mechanism 28 operates in accordance with the pitch mark of the strip film 1. In this way, a part of the belt-like film 1 being fed is pushed up by the roller 27, and the pushed-up portion is pressed against the end of the band-like film 1 on standby on the pay-out side. Then, the band-shaped film 1 being fed and the band-shaped film 1 in a standby state are joined by means such as heat welding or bonding with an adhesive.

Next, by the operation of the cylinder mechanism 29,
A cutter (not shown) attached to a part of the roller 26 projects to cut off the remaining portion of the belt-like film 1 in use, and the belt-like film 1 on the holding shaft 17 side at the standby position is newly fed. When the two strip films 1 are joined in this manner, the operation of the cylinder mechanism 24 causes the splice arm 23 to rotate clockwise in FIG. 2 and return to the original position. Similarly, the cylinder mechanism 28,
29 also returns to its original position.

Further, the driving of the electric motor 9 rotates the holding arm 15 counterclockwise by a predetermined angle, and stops the holding arm 15 when the holding shaft 17 at the standby position moves to the use position. For this reason, the holding shaft 17 stopped at the use position moves to the standby position, and an unused band film is mounted in place of the used band film 1 mounted on the holding shaft 17. In addition, after the film joining portion is automatically removed, the mode is switched to the normal operation mode in which the transport speed of the strip film 1 is increased by increasing the rotation speed of the drive roller 82.

The belt-like film 1 sent from the tension control mechanism 4 to the meandering adjustment mechanism 5 due to the operation accompanying the exchange of the belt-like film 1 as described above or the sticking operation of the film on the sticking mechanism 7 side. Has a constant tension in the longitudinal direction. For example, if the pitch of the pattern printed on the strip film 1 is different from the supply interval of the cans, the transport speed of the strip film 1 sent to the sticking roller 89 is controlled.

In this embodiment, the control contents when the tension of the strip film 1 fluctuates will be specifically described. When the tension of the belt-shaped film 1 sent from the guide roller 44 to the guide roller 45 fluctuates due to the various operations described above, the dancer roller 64 moves in the horizontal direction. Specifically, when the tension of the strip film 1 increases, the rack base 51 is horizontally moved leftward in FIGS. 1 and 2 based on the correspondence between the elastic force and the tension of the compression coil springs 55 and 56. Moving. On the other hand, when the tension of the belt-shaped film 1 decreases, the rack base 51 moves horizontally to the right in FIGS. 1 and 2 based on the correspondence between the elastic force and the tension of the compression coil springs 55 and 56. Moving.

As a result, the pinion gear 69 and the rotor 68 of the VARICAM 67 rotate in a predetermined direction by a predetermined angle in accordance with the moving amount and the moving direction of the rack base 51. Then, the rotation direction and the rotation angle of the rotor 68 are detected by the VARICAM controller 71,
The horizontal position of the rack base 51, that is, the relative position between the dancer roller 64 and the guide rollers 44 and 45 is calculated. Based on the calculation result, the actual tension of the strip film 1 supplied to the guide roller 45 via the dancer roller 64 is determined.

Next, the variable cam controller 71 compares the target tension value with the detected tension value, and turns on / off an output signal corresponding to the comparison result. here,
Since the rotor 68 always rotates (vibrates) about 1 to 3 degrees while the belt-shaped film 1 is being conveyed, a dead zone is set within a certain range from the target value of the tension. In this embodiment,
The dead zone is set within a range of ± 5 degrees with respect to the target value. The calculation error of the tension due to the dead zone is within an error range of ± 0.05 kgf as compared with the actual tension, and does not hinder the tension control of the belt-shaped film 1.

Next, a PID control signal is output from the electronic control unit 72, and this signal is processed by the D / A converter 73 to control the voltage applied from the power supply 74 to the powder brake 18. In this manner, the braking force of the powder brake 18 on the holding shaft 17 that holds the unwinding strip film 1 is controlled, and the rotation speed of the holding shaft 17, that is, the feed speed of the unwinding strip film 1 (in other words, the feeding speed) The feed amount is controlled, and feedback control is performed so that the tension of the strip film 1 becomes a predetermined value. When the tension of the belt-shaped film 1 is set to a predetermined value, the braking force of the powder brake 18 is controlled to that state, and the rack base 51 stops at a predetermined position in the horizontal direction.

As described above, in the above-described embodiment, even when the dancer roller 64 moves horizontally due to a change in tension, the horizontal movement direction of the dancer roller 64, the front area 1B and the rear area 1B of the folded portion 1A of the belt-shaped film 1 can be obtained.
C are configured to be parallel to each other. Further, as shown in FIG. 1, the angle θ1 formed between the area between the dancer roller 64 and the guide roller 45 in the strip film 1 and the area between the guide roller 45 and the roller 75 in the strip film 1 is controlled to be constant. In addition, the dancer roller 64 and the guide roller 44 in the belt-shaped film 1 are
And the guide roller 4 in the film strip 1
4 is also controlled to be constant.

Therefore, the tension of the strip film 1 in the transport path P1 can be uniquely and accurately determined based on the horizontal operation position of the dancer roller 64. Accordingly, the guide roller 4 is moved from the dancer roller 64 to the guide roller 4.
The tension of the belt-shaped film 1 supplied to the roller 5 and the roller 75 can be controlled with high precision, and the tension control function is improved. In addition, there is no need to store complicated set values and enormous data for estimating the actual tension of the strip film 1 in the electronic control unit 72, and the actual tension is calculated by a relatively simple calculation formula or program. Can be calculated, and the powder brake 1 necessary for controlling the tension of the belt-like film 1 can be calculated.
8 can be simplified and the cost of the system can be reduced.

The tension of the strip film 1 at the initial position of the dancer roller 64 and the rotor 68 of the VARICAM 67
And the correlation with the phase becomes constant, and the estimation accuracy and the control accuracy of the tension can be stabilized. As described above, in this embodiment, since the estimation and control of the tension in the longitudinal direction of the strip film 1 can be reliably performed, the occurrence of wrinkles and meandering is suppressed regardless of the thickness and the material of the strip film 1. can do.

In particular, when the present invention is applied to an apparatus for sticking a strip-shaped film on which a pattern is printed to the outer peripheral surface of a can body as in this embodiment, a dimensional error in the longitudinal direction of the cut film sheet is avoided. In addition, troubles such as meandering and wrinkles of the film sheet hardly occur, and the appearance and the quality of the appearance of the film sheet after being attached to the can are improved.

Further, the tension control mechanism 4 applies a force in a direction opposite to the force acting on the dancer roller 64 in accordance with the tension of the linear shaft 49 and the belt-shaped film 1 to the dancer roller 6.
And compression coil springs 55 and 56 applied to the shaft 4.
9 is detachable. Therefore, for example, the screw member 50 of the shaft holder 46 is loosened to remove the shaft holder 46 from the block 40, and the compression coil springs 55 and 56 are replaced to change the spring constant, thereby changing the tension of the strip film 1. The horizontal movement amount (movement rate, movement rate) of the dancer roller 64 and the change amount of the rotation angle of the rotor 68 (change rate of the rotation angle, change rate of the rotation angle) corresponding to the above can be made remarkable. Therefore, even when the width, material, thickness, and the like of the belt-shaped film 1 are changed, it is possible to easily increase the actual tension detection range, improve the detection accuracy, and improve the tension control accuracy.

Further, in this embodiment, since the PID control is used for the tension control of the strip film 1, smooth control without hunting is performed by the proportional operation, the offset is automatically corrected by the integral operation, and the differential operation is performed. The response corresponding to the disturbance can be made faster by the operation. Therefore,
The operation from the start of the can body film sticking system K1 to the stop of the dancer roller 64 at the initial position and the application of the predetermined tension to the belt-shaped film 1 can be converged in a short time.

Further, in this embodiment, since the rotation angle of the rotor 68 is detected by a multi-rotation type position detection sensor, a mechanical position detection mechanism (for example, a limit switch type Movement length), and can be manufactured at lower cost, and
Even if there is noise due to vibration, the rotation angle of the rotor 68 can be accurately detected.

In this embodiment, the rack 6
The correspondence between the horizontal movement amount of the dancer roller 64 and the rotation angle of the rotor 68 of the variable cam 67 can be freely changed by changing the design of the number of teeth of the pinion 69 and the outer diameter of the pinion 69. . By making such a design change, it is possible to cope with a belt-like film having a small tension to be set (for example, 0.5 to 2.0 kgf).

Further, as the urging means for moving the dancer roller 64 in the horizontal direction in accordance with the tension of the belt-like film 1, a hydraulic pressure is used in place of the compression coil springs 55 and 56 which are metal springs having a constant spring constant. Alternatively, a synthetic resin spring such as a fluid spring using an air pressure, a rubber spring, or the like, a composite spring combining a metal spring and a rubber spring, a composite spring combining an air spring and a metal spring, or the like can be used. In the present invention, the mechanism for transporting the belt-shaped member is not limited to the roller, but may be a guide member or the like. Further, the tension control device for a belt-shaped member of the present invention sticks a film label obtained by cutting a band-shaped film to an outer surface of a container other than a metal can, for example, a glass bottle or a plastic bottle. Applicable to systems.

[0063]

As described above, according to the first aspect of the present invention, since the movable guide member operates in a direction substantially parallel to the belt-shaped member to be transported, the movable guide member is located on the front side of the portion where the transport direction of the belt-shaped member is changed. The region and the rear region are maintained in a substantially parallel state. For this reason, the tension of the belt-shaped member in the transport path between the plurality of transport mechanisms can be uniquely determined based on the operation amount of the movable guide member. Therefore, the tension of the belt-shaped member in the transport path between the plurality of transport mechanisms can be controlled with high accuracy, and the tension control function is improved.
In addition, complicated setting values and a large amount of data for estimating the actual tension of the belt-shaped member are not required, and the actual tension can be calculated by a relatively simple calculation formula or program. Simplification of the sequence control accompanying the control of the tension and the cost reduction of the system.

In addition, regardless of the amount of movement of the movable guide member, the front area and the rear area of the transfer direction changing portion of the belt-shaped member are maintained in a substantially parallel state. Therefore, the correlation between the tension of the belt-shaped member at the initial position of the movable guide member and the position of the movable guide member becomes constant, and the accuracy of the estimation and control of the tension can be stabilized. Therefore, generation of wrinkles and meandering can be suppressed irrespective of the thickness and material of the band-shaped member.

According to the second aspect of the present invention, in addition to obtaining the same effect as the first aspect, by replacing the metal spring and changing its spring constant, the movable guide member corresponding to the tension of the band-shaped member is changed. The amount of operation can be increased.
Therefore, even when the dimensions and material of the belt-shaped member are changed, the detection range of the tension is expanded and the detection accuracy is improved,
In addition, the control accuracy of the tension can be easily improved.

[Brief description of the drawings]

FIG. 1 is a partially determined front view showing a tension control mechanism of a film sticking system for a can body to which the present invention is applied.

FIG. 2 is a front view showing the overall configuration of a can body film sticking system to which the present invention is applied.

FIG. 3 is a partially cutaway side view of the unwinding mechanism shown in FIG. 2;

FIG. 4 is a plan view showing a main part of the tension control mechanism shown in FIG. 2;

FIG. 5 is a side view showing a main part of the tension control mechanism shown in FIG. 2;

FIG. 6 is a block diagram showing a control circuit of the tension control mechanism and the unwinding mechanism shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Strip film, 1A ... Direction change part, 1B ... Front side area, 1C ... Rear side area, 44, 45 ... Guide roller, 49 ... Shaft, 51 ... Rack base, 55,
56 ... compression coil spring, 59 ... slider,
63: Shaft, 64: Dancer roller, 66: VARICAM, 71: VARICAM controller, 72: Electronic control unit, 73: D / A converter, 74: Power supply, K1: Film sticking system for can body, P1: Transport path .

Claims (2)

[Claims] 1. A tension control device for a belt-like member that conveys the belt-like member in a longitudinal direction, determines the tension of the belt-like member, and controls the tension of the belt-like member based on a result of the determination. A plurality of transport mechanisms for transporting in the longitudinal direction, and arranged in a transport path between the plurality of transport mechanisms to change the transport direction of the belt-shaped member, and at the front side of the transport direction conversion portion of the belt-shaped member. A movable guide member around which the band-shaped member is looped so that the region and the rear region are substantially parallel to each other; and the movable guide member is operably held according to a change in tension of the band-shaped member. The operation direction of the movable guide member, the front side area of the transfer direction conversion portion of the belt-shaped member,
And an operation direction setting mechanism for controlling the belt-shaped member to be in a direction substantially parallel to a rear side region of the transfer direction changing portion; and a force acting on the movable guide member in accordance with a tension of the band-shaped member. Comprises an elastic mechanism having a constant elastic coefficient for applying a force in the opposite direction to the movable guide member, and a tension determining mechanism for determining the tension of the band-shaped member based on the amount of operation of the movable guide member. A tension control device for a belt-shaped member. 2. The moving direction setting mechanism has a linear guide member, and the elastic mechanism applies a force in a direction opposite to a force acting on the movable guide member in accordance with a tension of the band-shaped member. The tension control device for a belt-shaped member according to claim 1, further comprising a metal spring provided to the guide member, wherein the metal spring is configured to be detachable from the guide member.