Binding device

Abstract

To provide a binding device that binds an article group consisting of multiple articles and is flexible enough to respond to changes in an external shape of the article group and the number of articles constituting the article group.SOLUTION: A binding device 100 includes conveying means 10, upper binding band feed means 23 having an upper servomotor 24, lower binding band feed means 33 having a lower servomotor 34, binding means 50 for binding an article group XA1 conveyed to a binding position N, and control means 60. The control means outputs a first torque command to the upper servomotor for each article group to feed out an upper binding band 25 of a first length from the upper binding band feed means, outputs a second torque command to the lower servomotor to feed out a lower binding band 35 of a second length, which is shorter than the first length, from the lower binding band feed means, and outputs a third torque command that generates torque lower than that in the second torque command to the lower servomotor during a binding period by the binding means.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a binding device, and more particularly to a binding device that automatically and continuously binds articles with heat-sealable binding straps (heat-sealable plastic films or the like). [Background technology]

[0002] Conventionally, in a binding device that automatically and continuously binds objects with heat-sealable binding straps, a technique is known in which the tension of the binding strap wrapped around the objects is kept constant by accurately positioning the objects at a predetermined position within the binding position, thereby tightly and stably binding the objects (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4366214 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology described in Patent Document 1, each item is always positioned at a fixed position within the binding position by the positioning means, so that it is difficult to adjust the tightness of the binding band. Specifically, when binding a group of items in which a plurality of individually packaged, relatively flexible rod-shaped items (e.g., fish sausages, etc.) are accumulated together with a binding band, even if the number of items in the group is the same (e.g., 5 items), the outer shape of the group of items (cross-sectional shape in a direction intersecting the length direction of the items), i.e., the shape of the wrapping of the binding band, does not necessarily have a fixed shape depending on the state of accumulation of the items, and may vary, for example, to an approximately diamond shape, an approximately triangular shape, an approximately pentagonal shape, etc. In addition, the number of items constituting one group of items may change in the binding line (e.g., a group of 5 items and a group of 4 items may be mixed). In either of these cases, the wrapping length of the binding band required for each group of items (hereinafter, referred to as the body circumference) changes.

[0005] Conventional binding devices were unable to flexibly respond to changes in the trunk circumference of a group of items due to variations in the external shape and number of each group of items, resulting in problems such as items falling off due to loose binding, deterioration of the quality of the items due to over-tightening of the binding strap, or poor binding due to insufficient heat sealing.

[0006] The present invention has been developed in consideration of the above-mentioned conventional problems, and aims to provide a binding device for binding a group of items consisting of a plurality of items, which can flexibly respond to changes in the external shape of the group of items and the number of items that make up the group, and can perform reliable binding. [Means for solving the problem]

[0007] The present invention includes a conveying means for moving a group of articles consisting of a plurality of articles on a conveying path, a first wrapper strap feeding means having a first servo motor and supplying a first wrapper strap to a binding position provided in the middle of the conveying path, a second wrapper strap feeding means having a second servo motor and supplying a second wrapper strap to the binding position, a binding means for wrapping the first wrapper strap and the second wrapper strap around the group of articles conveyed to the binding position and sealing the excess length of the wrap to bind the group of articles, and a control means, wherein the control means controls the first servo motor and the second wrapper strap feeding means to feed the first wrapper strap and the second wrapper strap around the group of articles conveyed to the binding position and seal the excess length of the wrap to bind the group of articles. The present invention relates to a binding device characterized in that a first control command including a first torque command is output to a motor to feed the first binding strap of a first length from the first binding strap feed means, a second control command including a second torque command is output to the second servo motor to feed the second binding strap of a second length shorter than the first length from the second binding strap feed means, and control is performed to output a command to the second servo motor to reduce torque during the period from the start to the completion of the sealing by the binding means (hereinafter referred to as the "binding period").

[0008] The present invention also relates to a binding device comprising: a conveying means for moving a group of articles consisting of a plurality of articles on a conveying path; a first cable tie feed means having an adjustment means and supplying a first cable tie to a binding position provided midway along the conveying path; a second cable tie feed means having a servo motor and supplying a second cable tie to the binding position; a binding means for wrapping the first cable tie and the second cable tie around the group of articles conveyed to the binding position and sealing the excess length of the wrap to bind the group of articles; and a control means, wherein the control means outputs a control command including a torque command to the servo motor for each group of articles to feed out the second cable tie from the second cable tie feed means, and controls to output a command to the servo motor to reduce torque during the period from the start to the completion of the sealing by the binding means (hereinafter referred to as the "binding period"). Effect of the Invention

[0009] According to the present invention, a binding device can be provided that binds a group of items consisting of a plurality of items, and that can flexibly respond to changes in the external shape of the group of items and the number of items that make up the group, and that can perform reliable binding. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic front view illustrating the overall configuration of a binding device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic plan view illustrating a conveying path of the binding device according to the first embodiment. [Diagram 3] 1A to 1C are diagrams illustrating a strap feeding means of a strapping device according to a first embodiment, in which (A) is a schematic front view, (B) is a schematic front view, and (C) is a schematic plan view. [Figure 4] FIG. 2 is a schematic front view illustrating the binding means of the binding device according to the first embodiment. [Diagram 5] FIG. 2 is a front schematic view illustrating an adjustment means of the binding device according to the first embodiment. [Figure 6] 4 is a timing chart illustrating the operation of the binding device according to the first embodiment. [Figure 7] FIG. 11 is a schematic front view illustrating the overall configuration of a binding device according to a second embodiment of the present invention. [Figure 8] 10 is a timing chart illustrating the operation of the binding device according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In this drawing and each of the following drawings, some configurations are omitted as appropriate to simplify the drawings. In this drawing and each of the following drawings, the size, shape, thickness, etc. of the members are exaggerated as appropriate. In the following description of this embodiment, the directions are defined as follows: a first direction in which the group of articles XA1 moves from upstream to downstream (from left to right in FIG. 1) is the conveying direction T, a second direction perpendicular to the conveying direction T is the conveying width direction W, and a third direction perpendicular to the conveying direction T and the conveying width direction W is the conveying height direction H.

[0012] First Embodiment First, a binding device 100 according to a first embodiment of the present invention will be described. <Binding device> 1 is a schematic front view showing an example of a binding device 100 according to this embodiment (first embodiment). The binding device 100 of this embodiment has a conveying means 10 for conveying a group of articles XA1, a first wrapper strap supplying device 20 for supplying a first wrapper strap 25, a second wrapper strap supplying device 30 for supplying a second wrapper strap 35, an adjusting means 40, a binding means 50 for binding the group of articles XA1 with an upper wrapper strap 25 and a lower wrapper strap 35, and a control means 60.

[0013] Fig. 2 is a top (plan) schematic diagram illustrating the conveying means 10, Fig. 3 is a front schematic diagram illustrating the first wrapper strap feed means 23 and the second wrapper strap feed means 33, Fig. 4 is a front schematic diagram illustrating the binding means 50, and Fig. 5 is a front schematic diagram illustrating the adjustment means 40. The first wrapper strap feed means 23 has a first servo motor 24, and the second wrapper strap feed means 33 has a second servo motor 34.

[0014] Here, the first cable tie supply device 20 (first cable tie feed means 23 and first servo motor 24) is provided on one side (in this example, the upper side in the conveying height direction H) of the conveying means 10, and the second cable tie supply device 30 (second cable tie feed means 33 and second servo motor 34) is provided on the other side (in this example, the lower side in the conveying height direction H) of the conveying means 10. In the following description, the first cable tie supply device 20, first cable tie feed means 23, first servo motor 24 and first cable tie 25 will be referred to as the upper cable tie supply device 20, upper cable tie feed means 23, upper servo motor 24 and upper cable tie 25, respectively. In addition, the second cable tie supplying device 30, the second cable tie feeding means 33, the second servo motor 34 and the second cable tie 35 are referred to as the lower cable tie supplying device 30, the lower cable tie feeding means 33, the lower servo motor 34 and the lower cable tie 35, respectively.

[0015] 1 and 2, the conveying means 10 is, for example, a finger conveyor that moves an article group XA1 consisting of a plurality of articles XA1' placed on the conveying path 11 along the conveying path 11. The conveying path 11 is formed by a pair of slide plates 11A that are arranged horizontally and parallel to each other at a predetermined interval as shown in FIG. 2, and the article group XA1 is placed on the upper part of the pair of slide plates 11A at predetermined intervals. As shown in FIG. 1, the conveying means 10 includes a pair of sprockets 16 that are rotatably provided below both ends of each slide plate 11A in the longitudinal direction, two chains 13 that are hung between the two sprockets 16 at a distance in the conveying width direction W and rotate along an elliptical path parallel to each slide plate 11A, a motor (not shown) that rotates one of the sprockets 16, and a plurality of conveying fingers 14 (front fingers 14A and rear fingers 14B) that are attached to the two chains 13 at predetermined intervals. As shown in Figures 1 and 2, multiple front fingers 14A and rear fingers 14B of one chain 13 and multiple front fingers 14A and rear fingers 14B of the other chain 13 are attached to each chain 13 at the same pitch in the longitudinal direction of each chain 13 and so as to face each other in the conveying width direction W.

[0016] Each transport finger 14 is configured to be movable along the inside of each slide plate 11A and to protrude upward from the upper surface of each slide plate 11A. In detail, the front finger 14A is erected at an angle with respect to the surface of the slide plate 11A so that the tip (upper) of the front finger 14A in the transport height direction H is located forward (downstream) in the transport direction T than the attachment portion (lower) of the chain 13. On the other hand, the rear finger 14B is erected in a direction approximately perpendicular to the surface of the slide plate 11A.

[0017] A set of article groups XA1 are arranged between the protruding portions of a pair of front fingers 14A and rear fingers 14B arranged in front and behind each other so as to be sandwiched between them. When both chains 13 are driven to rotate, each article group XA1 is transported in the transport direction T (from left to right in FIG. 1) by the pair of front fingers 14A facing each other in the transport width direction W and the pair of rear fingers 14B facing each other in the transport width direction W.

[0018] <Upper and lower cable tie supply devices> 1 and 3, upper wrapper strap supplying device 20 has, for example, an original roll support section 21 for upper wrapper strap 25, a plurality of rollers 22 around which upper wrapper strap 25 is stretched, and upper wrapper strap feeding means 23 for feeding upper wrapper strap 25 toward a binding position N provided midway along conveying path 11. Binding position N is a position where upper wrapper strap 25 and lower wrapper strap 35 are bound (sealed) by binding means 50, which will be described later.

[0019] The upper wrapper strap feeding means 23 has an upper feed roller 27 that pinches the upper wrapper strap 25, an upper pressure roller 26 rotatably attached to a rotating shaft (not shown), and an upper servo motor 24 that rotates and drives the upper feed roller 27. During operation of the binding device 100, the upper pressure roller 26 and the upper feed roller 27 are fixed in position, and the upper wrapper strap 25 is pinched between the upper feed roller 27 and the upper pressure roller 26 without slipping relative to them. The upper servo motor 24 rotates and drives the upper feed roller 27 based on a control command output from the control means 60, whereby a predetermined amount (length) of the upper wrapper strap 25 according to the control command is fed toward the binding position N for each article group XA1. In this embodiment, after the upper wrapper strap feed means 23 feeds out a predetermined amount (first length L1) of the upper wrapper strap 25 for a certain set of article groups XA1, it stops the rotation of the upper feed roller 27. The upper wrapper strap 25 is clamped between the upper feed roller 27 and the upper pressure roller 26 without slipping, and the supply (feed-out) of the upper wrapper strap 25 is also stopped when the upper feed roller 27 stops rotating. The first length L1 is a length required to bind the article group XA1, and is, for example, approximately 1 / 2 the circumference of the article group XA1.

[0020] The lower wrapper strap feeding means 33 has an original roll support section 31 for the lower wrapper strap 35, a plurality of rollers 32 around which the lower wrapper strap 35 is stretched, and a lower wrapper strap supply device 30 that supplies the lower wrapper strap 35 toward the binding position N provided midway along the conveying path 11. The lower wrapper strap supply device 30 has a lower feed roller 36 and a lower hold-down roller 37 that can pinch the lower wrapper strap 35, and a lower servo motor 34 that drives and rotates the lower feed roller 36. The lower servo motor 34 drives and rotates the lower feed roller 36 based on a control command output from the control means 60, whereby an amount (length) of the lower wrapper strap 35 according to the control command is fed toward the binding position N. As will be described later, in this embodiment, based on a control command output from the control means 60, the lower wrapper strap 35 is either clamped between the lower feed roller 36 and the lower pressure roller 37 without slipping and sent out toward the binding position N, or sent out toward the binding position N while slipping against the lower feed roller 36 and the lower pressure roller 37.

[0021] <Binding means> Fig. 4 is a schematic front view of the binding means 50, Fig. 4(A) and Fig. 4(B) are schematic front views showing the binding state in chronological order, Fig. 4(C) is an enlarged view of Fig. 4(A) and Fig. 4(D) is an enlarged view of the vicinity of the binding means 50 of Fig. 4(A), and Fig. 4(B) is an enlarged view of Fig. 4(C) and Fig. 4(D) are enlarged views of Fig. 4(B) showing the lengths of the upper and lower wrap straps 25 and 35. Fig. 4(E) is a view explaining the first length L1. Fig. 4(D) and Fig. 4(E) omit the illustration of the sealer 51.

[0022] 1 and 4, the binding means 50 has a pair of sealers 51 (e.g., upper sealer 51A and lower sealer 51B) arranged one above the other in the example of FIG. 1 on either side of the conveying path 11, and a drive mechanism (e.g., an air cylinder, etc.) 52 that moves the sealers 51 toward or away from the conveying path 11 in a direction approximately perpendicular to the conveying path 11.

[0023] As shown in Fig. 4(A), at the bundling position N, the upper sealer 51A comes into contact with the upper wrapper strap 25 and pushes it downward, and the lower sealer 51B comes into contact with the lower wrapper strap 35 and pushes it upward, approaching each other. As a result, as shown in Fig. 4(B), the upper wrapper strap 25 and the lower wrapper strap 35 are wrapped around the group of articles XA1 being transported to the bundling position N. The excess length of the upper wrapper strap 25 and the lower wrapper strap 35 are then sealed to bind the group of articles XA1.

[0024] 4(C) and 4(D), when the upper wrapper strap 25 and the lower wrapper strap 35 are bound (sealed) by the binding means 50, the upper wrapper strap feeding means 23 stops feeding the upper wrapper strap 25 after the first length L1 required for binding is supplied to the upper wrapper strap 25. The upper wrapper strap 25 is pinched by the upper feed roller 27 and the upper hold-down roller 26 without slipping against them. The first length L1 is, for example, approximately 1 / 2 the length of the circumference of the article group XA1, and strictly speaking, as shown in FIG. 4(E), is the length of the front and rear seal areas L1b, L1c in the conveying direction T during conveying (in the following description, the length of the front and rear seal areas L1b, L1c will be omitted and will be referred to as "approximately 1 / 2 the length of the circumference of the article group XA1").

[0025] After the lower wrapper strap 35 is fed by the second length L2, which is shorter than the first length L1, the lower wrapper strap feeding means 33 stops feeding the lower wrapper strap 35. The lower wrapper strap 35 is pinched by the lower feed roller 36 and the upper pressure roller 37 without slipping.

[0026] At this point, the total length (L1+L2) of the supplied upper and lower wrapper straps 25 and 35 is insufficient (shortage length Lx) relative to the overall wrapper strap length L3 that is necessary and sufficient for binding the group of articles XA1.

[0027] Therefore, when the binding means 50 presses the upper and lower cable ties 25 and 35 together and binds (seals) them, the upper and lower cable ties 25 and 35 are squeezed by the binding means 50, so that the upper and lower cable ties 25 and 35 adhere closely to the outer shape of the group of articles XA1 and a squeezing tension is generated in the upper and lower cable ties 25 and 35.

[0028] Thereafter, as will be described in detail later, the control means 60 issues a control command to supply the shortfall length Lx from the lower wrapper strap feed means 33 in accordance with the squeezing tension of the binding means 50. If there is a change in the external shape of the group of articles XA1, the overall wrapper strap length L3 necessary and sufficient for binding the group of articles XA1 will also change, and the shortfall length Lx will also change. In this embodiment, the shortfall length Lx is supplied in accordance with the squeezing tension of the binding means 50, so that the overall wrapper strap length L3 necessary and sufficient for binding the group of articles XA1 can be supplied, enabling reliable binding.

[0029] <Adjustment means> 1 and 5, for example, the upper wrapper strap feed means 23 includes an adjustment means 40. When the supply (feed-out) of the upper wrapper strap 25 is stopped due to the upper feed roller 27 stopping rotation, the adjustment means 40 adjusts the tension of the upper wrapper strap 25 present between the upper feed roller 27 and the binding position N. The adjustment means 40 has a swing shaft 41 (e.g., a rotation shaft of the upper pressure roller 26) fixedly attached to the binding device 100 (its base, not shown), an arm 42 one end of which is attached to the swing shaft 41 so as to be able to swing freely, a dancer roller 43 attached to the other end of the arm 42, a biasing means (elastic member, e.g., a spring) 44 one end of which is attached to the dancer roller 43, and an air cylinder 45 connected to the other end of the biasing means 44.

[0030] Fig. 5(A) shows a case where the tension of the upper wrapper strap 25 is not adjusted (not possible) (outside the tension adjustment period). Outside the tension adjustment period, the air cylinder 45 extends. This releases the force on the dancer roller 43, and the dancer roller 43 moves to the stop position shown in Fig. 5(A).

[0031] 5(B) to 5(D) show a case where the tension of the upper wrapper strap 25 is adjusted (tension adjustment period). During the tension adjustment period, as shown in FIG. 5(B), the air cylinder 45 is compressed to move the dancer roller 43 backward (upstream) in the conveying direction T via the biasing means 44 (a biasing force is applied to move the dancer roller 43 upstream (to the left in the figure)). In this state, the dancer roller 43 can move back and forth in the conveying direction T within a predetermined range depending on the magnitude relationship between the tension applied to the upper wrapper strap 25 and the biasing force of the biasing means 44 (e.g., the elastic force of a spring) (the biasing force of the biasing means 44 is set in this manner).

[0032] When the dancer roller 43 is in the position shown in Fig. 5(C), the tension of the upper wrapper strap 25 between the upper feed roller 27 and the binding position N is reduced, and if the upper wrapper strap 25 is too tightly fastened by the squeezing of the binding means 50, the fastening is reduced. On the other hand, when the dancer roller 43 is in the position shown in Fig. 5(D), the tension of the upper wrapper strap 25 between the upper feed roller 27 and the binding position N is increased, and if there is slack in the upper wrapper strap 25, the slack is absorbed.

[0033] <Control means> The control means 60 is composed of a CPU, memories such as RAM and ROM, storage devices such as HDD and SDD, and generally controls the binding device 100. The CPU is a so-called central processing unit, and executes various programs to realize various functions. The RAM is used as a working area for the CPU. The ROM and / or storage device store the basic OS and programs executed by the CPU.

[0034] Although not shown, the control means 60 of this embodiment also has a torque command generating section that generates and outputs torque commands for the upper servo motor 24 and the lower servo motor 34, a position command generating section that generates and outputs position commands, and a speed command generating section that generates and outputs speed commands. This outputs control commands to the upper servo motor 24 and the lower servo motor 34, respectively. The control commands include a torque command, a position command, and / or a speed command.

[0035] The control means 60 outputs a first control command (first torque command and first position command and / or first speed command) to the upper servo motor 24 to feed the upper wrapper strap 25 of the first length L1 from the upper wrapper strap supply device 20 (upper wrapper strap feeding means 23) toward the binding position N. Here, the first length L1 is the amount of upper wrapper strap 25 required (planned) to bind one set of articles XA1, and is, for example, approximately half the binding circumference of one set of articles XA1.

[0036] Furthermore, the control means 60 outputs a fourth control command to the upper servo motor 24 at least during the period when the binding means 50 is binding the group of articles XA1 (this is referred to as the "binding period"). The fourth control command is a command to maintain the torque based on the first torque command in the upper servo motor 24 (a fourth torque command instructing the same torque output as the first torque command) and to stop the rotation of the upper feed roller 27 (a command including a fourth position command and / or a fourth speed command). This stops the feed of the upper wrapper strap 25 from the upper wrapper strap feed means 23.

[0037] Furthermore, the control means 60 outputs a second control command (a second torque command and a second position command and / or a second speed command) to the lower servo motor 34 to feed the lower wrapper strap 35 of the second length L2 from the lower wrapper strap supply device 30 (lower wrapper strap feeding means 33) toward the binding position N. Here, the second length L2 is, for example, a length shorter than half the binding circumference of the set of article group XA1.

[0038] Furthermore, during the bundling period, the control means 60 outputs a third control command (a third torque command and a third position command and / or a third speed command) to the lower servo motor 34. This third torque command is a command that generates a torque lower than the second torque command.

[0039] <Control command (torque command)> Next, the control commands, particularly the torque commands, of this embodiment will be described. For example, the first control command for the upper servo motor 24 is a command for the upper wrapper strap 25, which is pinched by the upper feed roller 27 and the upper pressure roller 26, to be fed in accordance with the amount of rotation of the upper feed roller 27 without slipping against the upper feed roller 27 and the upper pressure roller 26. In this case, the feeding of the upper wrapper strap 25 is completely (100%) driven by the upper servo motor 24. In this embodiment, the torque generated in the upper servo motor 24 when the feeding of the upper wrapper strap 25 is 100% driven by the upper servo motor 24 is set as a reference (100%), and the torque command value is expressed as a ratio to this torque (the same applies to the lower servo motor 34).

[0040] For example, before the binding period, the upper servo motor 24 feeds out the upper wrapper strap 25 of the first length L1 based on a first control command. This first control command is a command that includes a first torque command of "100% torque" and a first position command and / or a first speed command that indicate "the number of rotations for feeding out the upper wrapper strap 25 of a predetermined amount required for binding, that is, the first length L1 (for example, approximately half the length of the trunk circumference of the article group XA1)."

[0041] During the binding period for a certain group of articles XA1, the upper servo motor 24 stops feeding the upper wrapper strap 25 from the upper wrapper strap supplying device 20 based on the fourth control command. The fourth control command is a command including a fourth torque command of "100% torque" and a fourth position command and / or a fourth speed command indicating "0 rotation speed."

[0042] Furthermore, before the binding period, the lower servo motor 34 feeds out the lower wrapper strap 35 of the second length L2 based on a second control command. This second control command is a command including a second torque command of "torque 100%" and a second position command and / or a second speed command indicating "the number of rotations for feeding out the lower wrapper strap 35 of the second length L2 (e.g., a length shorter than 1 / 2 the waist circumference of the article group XA1)."

[0043] During the bundling period for a certain group of articles XA1, the lower servo motor 34 is controlled based on a third control command. The third control command is a command including a third torque command lower than the second torque command, for example, a "torque 10%", and a third position command and / or a third speed command indicating a "rotation speed '0'".

[0044] In this embodiment, the lower servo motor 34 is controlled based on the second' control command during the period from when the lower wrapper strap 35 of the second length L2 is fed out until the third control command is received. The second' control command includes a second' torque command, a second' position command, and / or a second' rotation command. The second' torque command is the same torque command value (100% torque) as the second torque command, and the second' position command and / or the second' rotation command are commands indicating "number of rotations '0'". In other words, the lower wrapper strap feed means 33 stops feeding the lower wrapper strap 35 during the period from when the lower wrapper strap 35 of the second length L2 is fed out until the third control command is received. The lower wrapper strap 35 is pinched between the lower feed roller 36 and the lower hold-down roller 37 without slipping.

[0045] By such control, before the binding period, the upper wrapper strap supplying device 20 supplies the upper wrapper strap 25 of the first length L1 (length equivalent to half the waist circumference of the set of articles XA1) and then stops supplying. Meanwhile, the lower wrapper strap supplying device 30 supplies the lower wrapper strap 35 of the second length L2 (length shorter than half the waist circumference of the set of articles XA1) and then stops supplying. In other words, as shown in FIG. 4(D), the total length of the wrapper straps (L1+L2) is insufficient (insufficient length Lx) compared to the total length L3 of the wrapper straps that is necessary and sufficient for binding the set of articles XA1. In this state, when binding by the binding means 50 begins during the binding period, the upper and lower wrapper straps 25 and 35 are wrapped around the group of articles XA1 by the adjacent upper and lower sealers 51A and 51B, and a squeezing tension is generated in the upper and lower wrapper straps 25 and 35 due to the proximity of the binding means 50 (upper sealer 51A and lower sealer 51B).

[0046] During this bundling period, the control means 60 outputs a third control command to the lower servo motor 34. The third control command includes a third torque command that generates a torque weaker than the tension of the ironing caused by the proximity of the bundling means 50 (the upper sealer 51A and the lower sealer 51B). Specifically, this torque command value is a torque command value lower than the second torque command, for example, "torque 10%." The third control command includes a third position command and / or a third speed command indicating "rotation speed '0'."

[0047] That is, in the lower wrapper strap feeding means 33, during the binding period, control is performed to reduce the torque output of the lower servo motor 34 from "torque 100%" (second torque command) to "torque 10%".

[0048] By this control, when the lower cable tie feed means 33 receives the third control command as shown in FIG. 4(D), when the tension of the lower cable tie 35 becomes greater than the torque output of the lower servo motor 34 depending on the squeezing tension, the lower feed roller 36 rotates in the film pay-out direction to feed the lower cable tie 35 by the missing length Lx toward the binding position N until the upper sealer 51A and the lower sealer 51B complete sealing (the binding means 50 is allowed to pull out the lower cable tie 35 by the missing length).

[0049] This enables the group of articles XA1 to be bound reliably without loosening (slack) or over-tightening.

[0050] Fig. 6 is a timing chart showing an example of the operation of each component of the binding device 100 of the first embodiment. In Fig. 6, one cycle of the binding process for one set of article group XA1 from the start of conveyance by the conveying fingers 14 to the separation into a single bound article (group) by bundling (sealing) and cutting is defined as 360°, and the operation timing from the initial state (bundling process cycle 0°) to the bundling process cycle 360° is shown. The initial state is, for example, a state in which the conveying fingers 14 conveying the target article group XA1 are at the initial position P0.

[0051] The "torque control timing" in the first upper row indicates the timing for executing torque control in the lower servo motor 34, particularly control based on a third control command including the third torque command (torque command value "10% torque", "rotation speed "0"), and "torque control on" indicates a period during which control based on the third torque command is performed. On the other hand, "torque control off" indicates a period during which control based on the third torque command is not performed, in other words, a period during which control based on a second control command including the second torque command (torque command value "100% torque", rotation speed for feeding out the second length L2) or control based on a second' control command (torque command value "100% torque", rotation speed "0") is performed.

[0052] The second row, "Upper servo feed," indicates the period during which the upper wrapper strap 25 is fed from the upper servo motor 24 toward the binding position N based on the first control command. The third row, "Lower servo feed," indicates the period during which the lower wrapper strap 35 is fed from the lower servo motor 34 toward the binding position N based on the second control command. The timing of the feed (stop) of the upper wrapper strap 25 and the timing of the feed of the lower wrapper strap 35 are approximately the same, but the feed period of the upper wrapper strap 25 is longer than the feed period of the lower wrapper strap 25.

[0053] The fourth row, "Upper cable tie adjustment," indicates the period during which the adjustment means 40 is able to adjust the tension of the upper cable tie 25 (movement of the dancer roller 43), "Adjusted" indicates the tension adjustment period, and "No adjustment" indicates outside the tension adjustment period.

[0054] The "sealer" in the fifth row indicates the open / closed state of the sealer 51 of the binding means 50, and the "fingers" in the sixth row indicate the periods (timing) of movement and stoppage of the transport fingers 14.

[0055] First, in the initial state of the bundling process (bundling process cycle 0°), the conveying finger 14 conveying the target article group XA1 is at the initial position P0 (see FIG. 1) and starts moving from a stopped state. The "torque control timing" is "torque control off", that is, control by the third torque command is not performed, and the "lower servo feed" is in the "feed" state. That is, the control means 60 outputs a second control command including a second torque command to the lower servo motor 34, and the lower wrapper strap 35 with the second length L2 shorter than the first length L1 is fed from the lower wrapper strap supply device 30 toward the bundling position N. The control means 60 also outputs a first control command including a first torque command to the upper servo motor 24, and the upper wrapper strap 35 with the first length L1 is fed from the upper wrapper strap supply device 20 toward the bundling position N.

[0056] Additionally, the "upper wrapper strap adjustment" is "not adjusted" and the adjustment means 40 is in the "off" state outside the tension adjustment period. The "sealer" is between "open" and "closed" with the sealer 51 in a state where it is spaced a predetermined distance, and then moves gradually away from there. The sealer 51 reaches its most open state at 77° in the strapping cycle, and remains in that state until 141°.

[0057] At the timing of 80° in the binding process cycle, the "lower servo feed" is "stopped." That is, at this timing, the lower servo motor 34 finishes feeding the lower wrapper strap 35 of the second length L2 based on the second control command, and is controlled based on the second' control command. That is, while maintaining the same torque command value (100% torque) as the second torque command, the "number of rotations becomes '0'" (i.e., feeding of the lower wrapper strap 35 is stopped).

[0058] After the feeding of the lower wrap strap 35 has stopped (for example, at a timing of 85°), the "upper servo feed" is "stopped." In other words, at this timing, the upper servo motor 24 finishes feeding the upper wrap strap 25 of the first length L1 based on the first control command, and is controlled based on the fourth control command. The fourth control command is a command that includes a fourth torque command of "torque 100%" and a fourth position command and / or a fourth speed command indicating "number of revolutions 0," and this causes the feeding of the upper wrap strap 25 to stop.

[0059] At the timing of 140° of the binding process cycle, the "upper wrapper strap adjustment" becomes "adjusted." In other words, the adjustment means 40 becomes "on" (tension adjustment period), and the adjustment means 40 can adjust the tension of the upper wrapper strap 25 (movement of the dancer roller 44).

[0060] At the timing of 141° of the binding process cycle (immediately after the adjustment means 40 is turned “ON”), the upper and lower sealers 51 start approaching each other to seal the upper and lower wrapper straps 25 and 35. This timing is the start timing of the binding period in this embodiment.

[0061] At the timing of 150° of the bundling process cycle (after the start of the bundling period), the conveying fingers 14 finish (stop) pushing the group of articles XA1.

[0062] After the conveying fingers 14 finish pushing the group of articles XA1, the upper servo motor 24 stops feeding the upper wrapper strap 25, and also stops feeding the lower wrapper strap 35 at 100% torque, and in this state the sealers 51 gradually approach each other. That is, at the binding position N, the upper sealer 51A abuts against the upper wrapper strap 25 and pushes it in, and the lower sealer 51B abuts against the lower wrapper strap 35 and pushes it in, moving closer to each other. As a result, the upper wrapper strap 25 and the lower wrapper strap 35 are wrapped around the group of articles XA1 being conveyed to the binding position N.

[0063] Here, the total length of the fed upper and lower cable ties 25 and 35 is insufficient for the waist circumference of the article group XA1, and as the sealer 51 approaches, a squeezing tension is generated in the upper and lower cable ties 25 and 35 due to the proximity of the binding means 50 (upper sealer 51A and lower sealer 51B).

[0064] During this binding period (for example, at the timing of 180° of the binding process cycle), the control means 60 outputs a third torque command (including a third control command) to the lower servo motor 34, and the "torque control timing" becomes "torque control on." The third torque command is a command to generate a torque (torque command value "10%) that is weaker than the squeezing tension caused by the proximity of the binding means 50 (upper sealer 51A and lower sealer 51B). The third position command and / or the third speed command is a command that indicates, for example, "number of rotations '0'."

[0065] When the lower cable tie feed means 33 receives the third control command, the lower cable tie 35 is fed toward the binding position N by the missing length Lx while sliding against the lower feed roller 36 and the lower pressure roller 37 in accordance with the squeezing tension of the sealer 51 (the binding means 50 is allowed to pull out the missing length of the lower cable tie 35, see Figures 4(C) and 4(D)).

[0066] Thus, in this embodiment, during the period when the third torque command (10% torque) is being output, the lower wrapper strap 35 is appropriately pulled out by the binding means 50 in accordance with the outer shape of the group of articles XA1 and the tension of the binding means 50. In other words, after the first length L1 of the upper wrapper strap 25 and the second length L2 of the lower wrapper strap 35 have been delivered, the lower wrapper strap 35 is pulled out based on the third control command to make up for the insufficient length Lx of the binding.

[0067] Furthermore, the adjustment means 40 is in the ON state at least during the binding period (after 140° of the binding process cycle). The biasing force (e.g., the elastic force of a spring) of the biasing means 44 in the adjustment means 40 is also set to a force weaker than the squeezing tension of the upper and lower wrapper straps 25 and 35 caused by the approach of the binding means 50. As a result, in the upper wrapper strap supply device 20, the tension of the upper wrapper strap 25 is adjusted according to the squeezing tension caused by the sealer 51.

[0068] In principle, the upper wrapper strap 25 supplies a predetermined amount in response to the first control command, and then the supply is stopped in response to the fourth control command. However, depending on the external shape of the article group XA1 (variation in the stacking state) and the stretching of the upper wrapper strap 25 and / or the lower wrapper strap 35, the predetermined amount may be in excess of or insufficient to the actual amount used.

[0069] In this embodiment, a biasing force weaker than the tension of the upper and lower wrapper straps 25 and 35 squeezed by the binding means 50 is applied to the dancer roller 43, so that when the binding means 50 starts squeezing the upper and lower wrapper straps 25 and 35 during the binding period, the dancer roller 43 moves according to that tension, and as a result, the tension of the upper wrapper strap 25 downstream of the upper servo motor 24 is adjusted. In other words, if any slack occurs in the upper wrapper strap 25 downstream of the upper servo motor 24, it is absorbed (FIG. 5(D)), or if there is a shortage (over-tightening), the dancer roller 43 moves to unwind it (FIG. 5(C)).

[0070] Returning to Fig. 6, at the timing of 240° in the binding process cycle, the "torque control timing" becomes "torque control off". In other words, at this timing, the control means 60 outputs a control command different from the third torque command (including the third control command) to the lower servo motor 34. This control command is, for example, the same as the second' control command (100% torque, rotation speed "0"). This causes the pulling out of the lower wrapper strap 35 to stop.

[0071] At the timing of bundling cycle 271° (the timing after "torque control off"), the sealers 51 are closest to each other, sealing the upper and lower wrapper straps 25 and 35 that are the excess length of the wrap, and in the period up to bundling cycle 307° (for example, at the timing of bundling cycle 307°), the sealed portion is cut to separate the single bundled group of articles XA1. In this embodiment, for example, the period from bundling cycle 141° (the point at which the upper and lower sealers 51 start to move toward each other) to the cutting of the sealed portion after bundling cycle 271° (for example, at the timing of bundling cycle 307°) is the "bundling period".

[0072] At the timing of 280° of the binding process cycle, the "upper wrapper strap adjustment" is set to "no adjustment", that is, the adjustment by the adjustment means 40 is turned off.

[0073] Thereafter, at the timing of 307° in the bundling process cycle, the upper and lower sealers 51 start to move in directions away from each other.

[0074] Thereafter, for example, at a timing of 315° in the binding process cycle, the "upper servo feed" is set to "feeding on", that is, based on the first control command, the upper servo motor 24 feeds the lower binding strap 35 of the first length L1 toward the binding position N to bind the next group of items XA1.

[0075] At the timing of 320° of the binding process cycle after the "upper servo feed" becomes "feeding in", the "lower servo feed" becomes "feeding in", that is, based on the second control command, the lower servo motor 34 feeds out the lower tie strap 35 of the second length L2 toward the binding position N.

[0076] Thus, in this embodiment, before the binding period, the upper wrapper strap 25 is supplied with a first length L1 (e.g., approximately half the length of the waist circumference of a set of article group XA1), which is a predetermined usage amount, and the lower wrapper strap 35 is supplied with a second length L2 shorter than the first length L1, resulting in a shortage of wrapper strap for binding the group of articles XA1. In this embodiment, with the supply of the upper wrapper strap 25 stopped during the binding period, the lower servo motor 34 is controlled to generate a torque weaker than the tension of the upper wrapper strap 25 and the lower wrapper strap 35 squeezed by the binding means 50 (in this example, a torque of 10% of the command value).

[0077] This allows the torque of the lower servo motor 34 to be overcome by the tension of the upper cable tie 25 and the lower cable tie 35, and the lower cable tie 35 to be pulled out (compensated) by the missing length Lx until the upper sealer 51A and the lower sealer 51B complete sealing.

[0078] The adjustment means 40 is configured to function at least during the binding period. When the adjustment means 40 functions (is turned on), the biasing means 44 biases the dancer roller 43 with a biasing force weaker than the tension of the upper and lower wrapper straps 25 and 35 applied by the binding means 50. Therefore, even if the supply of the upper wrapper strap 25 is stopped by the fourth control command, the dancer roller 43 can adjust the tension of the upper wrapper strap 25 downstream of the upper servo motor 24 to absorb slack in the upper wrapper strap 25 or pay out the insufficient amount.

[0079] As a result, each group of articles XA1 can be bound reliably along its outer shape without loosening or over-tightening. In this way, a binding device 100 can be provided that can flexibly accommodate changes in the outer shape and number of articles of the group of articles XA1.

[0080] Incidentally, even if the supply of the upper wrap strap 25 stops, the lower wrap strap 35 is allowed to be pulled out (supplemented) by the missing length Lx, so the adjustment means 40 does not need to be provided in the above-mentioned binding device 100.

[0081] <Second embodiment> Next, a description will be given of a binding device 100' according to a second embodiment of the present invention. Fig. 7 is a schematic front view showing an example of the binding device 100' according to the second embodiment, and Fig. 8 is a timing chart showing an example of the operation of each component of the binding device 100' according to the second embodiment.

[0082] With reference to FIG. 7, the upper servo motor 24 may be omitted in the upper wrapper strap supply device 20' (upper wrapper strap feeding means 23') of the binding device 100'. In this case, the upper feed roller 27' is attached rotatably around a rotation axis, and the upper pressure roller 26' is a roller that does not rotate at all times. The upper feed roller 27' and the upper pressure roller 26' are configured to approach and move away from each other during operation of the binding device 100', and when they approach each other, the upper wrapper strap 25 is pinched. When the upper feed roller 27' and the upper pressure roller 26' are separated, the upper wrapper strap 25 is supplied toward the binding position N, and when it is pinched between the upper feed roller 27' and the upper pressure roller 26', the supply is stopped. In other words, the upper feed roller 27' and the upper pressure roller 26' function as a "wrapper strap holding means 28" that holds down the supply of the upper wrapper strap 25. Other than this, the configuration is almost the same as in the first embodiment, and the same components are denoted by the same reference numerals as in Fig. 1. Below, the differences from the first embodiment will be mainly described.

[0083] The binding device 100' comprises a conveying means 10 for moving an article group XA1 consisting of a plurality of articles XA1' along a conveying path 11, a first (upper) wrapper strap feed means 23' having an adjustment means 40 and supplying a first (e.g., upper) wrapper strap 25 to a binding position N provided midway along the conveying path 11, a second (lower) wrapper strap feed means 33 having a lower servo motor 34 and supplying a second (lower) wrapper strap to binding position N, a binding means 50 for wrapping the upper wrapper strap 25 and the lower wrapper strap 35 around the article group XA1 being conveyed to binding position N and sealing the excess length of the wrap to bind the article group XA1, and a control means 60.

[0084] <Upper and lower cable tie supply devices> The upper wrapper strap supplying device 20' of the second embodiment is configured so that the upper wrapper strap 25 is pulled out (sent out) in accordance with the movement of the group of articles XA1 pushed toward the binding position N by the conveying means 10, and the sending out and stopping of the upper wrapper strap 25 are controlled by the wrapper strap holding means 28 (upper feed roller 27' and upper hold down roller 26'). In other words, when the upper feed roller 27' and the upper hold down roller 26' are separated, the upper wrapper strap 25 is pulled out by a first length L1' (according to the movement) in accordance with the movement of the group of articles XA1 immediately upstream of the binding position N. Then, as will be described later, when the wrapper strap holding means 28 approaches at a certain timing and pinches the upper wrapper strap 25, the pulling out (sent out) stops. In the first embodiment, the feed amount (first length L1) of the upper wrapper strap 25 was set by controlling the upper servo motor 24, but in the second embodiment, the feed length (first length L1') of the upper wrapper strap 25 may differ (vary in length) for each article group XA1 due to variations in the external shape of the article group XA1, etc. The first length L1' is generally about 1 / 2 the circumference of the body of the article group XA1.

[0085] The lower wrapper strap feeding means 33 has the same configuration as that of the first embodiment, and the lower servo motor 34 rotates and drives the lower feed roller 36 based on a control command output from the control means 60, thereby feeding the lower wrapper strap 35 toward the binding position N by an amount (length) according to the control command. The amount of the lower wrapper strap 35 fed by the lower servo motor 34 is a predetermined value (second length L2) based on the control command. The second length L2 is shorter than 1 / 2 the circumference length of the article group XA1. Based on the control command output from the control means 60, the lower wrapper strap 35 may be sandwiched between the lower feed roller 36 and the lower pressure roller 37 and fed toward the binding position N without slipping against them, or may be fed toward the binding position N while slipping against the lower feed roller 36 and the lower pressure roller 37.

[0086] <Binding means>

[0087] 4, when the upper wrapper strap 25 and the lower wrapper strap 35 are bound (sealed) by the binding means 50, the upper wrapper strap 25 is fed a first length L1' corresponding to the amount of movement of the group of articles XA1 by the conveying device 10, and then the feeding of the upper wrapper strap 25 is stopped by the wrapper strap holding means 28. Also, the lower wrapper strap 35 is fed a second length L2 that is shorter than 1 / 2 the circumference length of the group of articles XA1, and then the lower wrapper strap feeding means 33 stops feeding the lower wrapper strap 35. The lower wrapper strap 35 is pinched by the lower feed roller 36 and the upper holding roller 37 without slipping relative to them.

[0088] At this point, the total length (L1'+L2) of the supplied upper and lower wrapper straps 25 and 35 is insufficient (shortage length Lx') relative to the overall wrapper strap length L3 that is necessary and sufficient for binding the group of articles XA1.

[0089] Therefore, when the binding means 50 presses the upper and lower cable ties 25 and 35 together and binds (seals) them, the upper and lower cable ties 25 and 35 are squeezed by the binding means 50, so that the upper and lower cable ties 25 and 35 adhere closely to the outer shape of the group of articles XA1 and a squeezing tension is generated in the upper and lower cable ties 25 and 35.

[0090] Thereafter, the lower wrapper strap 35 is supplied from the lower wrapper strap feed means 33 in response to the tension of the binding means 50 by a control command from the control means 60. In addition, in some cases, the upper wrapper strap 25 is supplied by the adjustment means 40 of the upper wrapper strap feed means 23, and the shortage length Lx is thereby supplemented. Here, if there is a change in the number of articles XA1' constituting the article group XA1 or in the external shape of the article group XA1, the total wrapper strap length L3 necessary and sufficient for binding the article group XA1 also changes, and the shortage length Lx' also changes. In this embodiment, the shortage length Lx' is supplemented by the supply of the lower wrapper strap 35 and, in some cases, the upper wrapper strap 25 in response to the tension of the binding means 50, so that the total wrapper strap length L3 necessary and sufficient for binding the article group XA1 can be supplied, enabling reliable binding.

[0091] <Adjustment means> 7 and 5, the upper wrapper strap feed means 23' includes an adjustment means 40. When the supply (feed-out) of the upper wrapper strap 25 is stopped by the wrapper strap holding means 28, the adjustment means 40 adjusts the tension of the upper wrapper strap 25 between the upper feed roller 27' and the binding position N. That is, similar to the first embodiment, during the tension adjustment period (FIG. 5(B)), the dancer roller 43 is moved back and forth in the conveying direction T within a predetermined range depending on the magnitude relationship between the tension applied to the upper wrapper strap 25 and the biasing force (e.g., the elastic force of a spring) of the biasing means 44 (the biasing force of the biasing means 44 is set in this manner).

[0092] When the dancer roller 43 is in the position shown in Fig. 5(C), the tension of the upper wrapper strap 25 between the upper feed roller 27 and the binding position N is reduced, and if the upper wrapper strap 25 is too tightly fastened by the squeezing of the binding means 50, the fastening is reduced. On the other hand, when the dancer roller 43 is in the position shown in Fig. 5(D), the tension of the upper wrapper strap 25 between the upper feed roller 27 and the binding position N is increased, and if there is slack in the upper wrapper strap 25, the slack is absorbed.

[0093] <Control means> The control means 60 has a torque command generating section that generates and outputs a torque command for the lower servo motor 34, a position command generating section that generates and outputs a position command, and a speed command generating section that generates and outputs a speed command. Thereby, control commands (second control command, second' control command, third control command) are output to the lower servo motor 34. The contents of these control commands are the same as those in the first embodiment.

[0094] The control means 60 outputs a second control command to the lower servo motor 34 to feed the lower wrapper strap 35 of the second length L2 from the lower wrapper strap supply device 30 (lower wrapper strap feeding means 33) toward the binding position N. After feeding the lower wrapper strap 35 of the second length L2, the control means 60 outputs a second' control command to the lower servo motor 34 to stop feeding the lower wrapper strap 35. Furthermore, the control means 60 outputs a third control command to the lower servo motor 34 during the binding period. This third torque command is a command to generate a torque lower than the second torque command.

[0095] With this control, before the binding period, the upper wrapper strap supplying device 20 supplies an upper wrapper strap 25 of a first length L1' (approximately half the circumference of the article group XA1, but there is variation for each article group XA1) and then stops supplying. Meanwhile, the lower wrapper strap supplying device 30 supplies a lower wrapper strap 35 of a second length L2 (shorter than half the circumference of the article group XA1) and then stops supplying. In other words, as shown in FIG. 4(D), the total length of the wrapper straps (L1'+L2) is insufficient (insufficient length Lx') compared to the total wrapper strap length L3 that is necessary and sufficient for binding the article group XA1. In this state, when binding by the binding means 50 begins during the binding period, the upper and lower wrapper straps 25 and 35 are wrapped around the group of articles XA1 by the adjacent upper and lower sealers 51A and 51B, and a squeezing tension is generated in the upper and lower wrapper straps 25 and 35 due to the proximity of the binding means 50 (upper sealer 51A and lower sealer 51B).

[0096] During this binding period, the control means 60 outputs a third control command to the lower servo motor 34, including a command (third torque command) to generate a torque weaker than the tension of the squeezing caused by the approach of the binding means 50. As a result, in the lower wrapper belt feeding means 33, when the tension of the lower wrapper belt 35 becomes greater than the torque output of the lower servo motor 34 according to the tension of the squeezing, the lower feed roller 36 rotates in the film payout direction until the upper sealer 51A and the lower sealer 51B complete sealing, so that the lower wrapper belt 35 is fed toward the binding position N by approximately the same amount as the insufficient length Lx' (the binding means 50 is allowed to pull out the lower wrapper belt 35 by the insufficient length). In addition, the tension of the upper wrapper belt 25 present between the upper feed roller 27' and the binding position N is adjusted by the adjustment means 40 depending on the circumstances. This enables the group of articles XA1 to be bound reliably without loosening (slack) or over-tightening.

[0097] An example of the operation of each component of the binding device 100' will be described with reference to Fig. 8. In the second embodiment, the sending out (pulling out) of the upper wrapper strap 25 depends on the movement of the group of articles XA1, and is therefore not subject to control by the binding device 100' (control means 60). On the other hand, the control means 60 controls the wrapper strap holding means 28, and therefore shows the timing of the operation (with / without holding) of the wrapper strap holding means 28 as "upper wrapper strap holding" in the fourth row.

[0098] In the fourth row, "upper wrapper strap holding" "with holding" is a period during which the upper wrapper strap 25 is pinched (held) by the upper feed roller 27' and the upper hold-down roller 26' and feeding is stopped, and "without holding" is a period during which the upper feed roller 27' and the upper hold-down roller 26' are separated and the upper wrapper strap 25 is fed (pulled out) by the movement of the group of articles XA1. The timing of the other rows (rows 1 to 3 and rows 5 and 6) is the same as in the first embodiment.

[0099] First, in the initial state of the bundling process (0° bundling process cycle), the conveying finger 14 that conveys the target group of articles XA1 is at the initial position P0 (see FIG. 1) and starts moving from a stopped state. The "torque control timing" is "torque control off", that is, control by the third torque command is not performed, and the "lower servo feed" is in the "feed" state. That is, the control means 60 outputs a second control command including a second torque command to the lower servo motor 34. As a result, the lower wrapper strap 35 of the second length L2 is fed from the lower wrapper strap supply device 30 toward the bundling position N. The control means 60 also separates the wrapper strap holding means 28 ("no hold" in "upper wrapper strap hold"), and the upper wrapper strap 35 is fed from the upper wrapper strap supply device 20 toward the bundling position N by relying on the movement of the group of articles XA1.

[0100] Also, the "upper wrapper strap adjustment" is "not adjusted" and the adjustment means 40 is in the "off" state outside the tension adjustment period. The "sealer" is between "open" and "closed" and the sealer 51 is in a state where it is spaced a predetermined distance, and then gradually moves away from there.

[0101] The sealer 51 is in the most open state at 77° in the bundling cycle, and remains in that state until 141°.

[0102] At the timing of 80° in the binding process cycle, the "lower servo feed" is "stopped." That is, at this timing, the lower servo motor 34 finishes feeding the lower wrapper strap 35 of the second length L2 based on the second control command, and is controlled based on the second' control command. That is, while maintaining the same torque command value (100% torque) as the second torque command, the "number of rotations becomes '0'" (i.e., feeding of the lower wrapper strap 35 is stopped).

[0103] At the timing of 140° of the binding process cycle, the "upper wrapper strap adjustment" becomes "adjusted." In other words, the adjustment means 40 becomes "on" (tension adjustment period), and the adjustment means 40 can adjust the tension of the upper wrapper strap 25 (movement of the dancer roller 44).

[0104] At the timing of 141° of the binding process cycle (immediately after the adjustment means 40 is turned “ON”), the upper and lower sealers 51 start approaching each other to seal the upper and lower wrapper straps 25 and 35. This timing is the start timing of the binding period in this embodiment.

[0105] At the timing of 150° of the bundling process cycle (after the start of the bundling period), the conveying fingers 14 finish (stop) pushing the group of articles XA1.

[0106] At the timing of 152° of the strapping process cycle (after the conveying finger 14 finishes pushing the group of articles XA1), the "upper strap holder (strap holder means 28)" is in the "holding" state. That is, at least during the strapping period, the control means 60 pinches the upper strap 25 with the strap holder means 28 and stops the upper strap 25 from being fed from the upper strap feed means 23. After this, the feed of the upper strap 25 is stopped, and the feed of the lower strap 35 is stopped at 100% torque, and the sealers 51 gradually approach each other. That is, at the strapping position N, the upper sealer 51A abuts against the upper strap 25 and pushes it in, and the lower sealer 51B abuts against the lower strap 35 and pushes it in, while they approach each other. As a result, the upper wrap strap 25 and the lower wrap strap 35 are wrapped around the group of articles XA1 transported to the bundling position N.

[0107] Here, the total length of the fed upper and lower cable ties 25 and 35 is insufficient for the waist circumference of the article group XA1, and as the sealer 51 approaches, a squeezing tension is generated in the upper and lower cable ties 25 and 35 due to the proximity of the binding means 50 (upper sealer 51A and lower sealer 51B).

[0108] During this binding period (for example, at the timing of 180° of the binding process cycle), the control means 60 outputs a third torque command (including a third control command) to the lower servo motor 34, and the "torque control timing" becomes "torque control on." The third torque command is a command to generate a torque (torque command value "10%) that is weaker than the squeezing tension caused by the proximity of the binding means 50 (upper sealer 51A and lower sealer 51B). The third position command and / or the third speed command is a command that indicates, for example, "number of rotations '0'."

[0109] When the lower cable tie feed means 33 receives the third control command, the lower cable tie 35 is fed toward the binding position N by the missing length Lx while sliding against the lower feed roller 36 and the lower pressure roller 37 in accordance with the squeezing tension of the sealer 51 (the binding means 50 is allowed to pull out the missing length of the lower cable tie 35, see Figures 4(C) and 4(D)).

[0110] Thus, in this embodiment, while the third torque command (10% torque) is being output, the binding means 50 pulls out the lower wrapper strap 35 appropriately in accordance with the outer shape of the group of articles XA1 and the tension of the binding means 50. In other words, after the first length L1' of the upper wrapper strap 25 and the second length L2 of the lower wrapper strap 35 have been fed out, the lower wrapper strap 35 is pulled out based on the third control command to make up for the insufficient length Lx' of the binding.

[0111] Furthermore, the adjustment means 40 is in the ON state at least during the binding period (after 140° of the binding process cycle). The biasing force (e.g., the elastic force of a spring) of the biasing means 44 in the adjustment means 40 is also set to a force weaker than the squeezing tension of the upper and lower wrapper straps 25 and 35 caused by the approach of the binding means 50. As a result, in the upper wrapper strap supply device 20, the tension of the upper wrapper strap 25 is adjusted according to the squeezing tension caused by the sealer 51.

[0112] In principle, the upper wrap strap 25 is supplied at any amount depending on the movement of the article group XA1, and then the supply is stopped by pinching with the wrap strap holding means 28. However, due to the external shape of the article group XA1 (variation in the stacking state), fluctuations in the number of articles XA1' that make up the article group XA1, or stretching of the upper wrap strap 25 and / or the lower wrap strap 35, the supply of the upper wrap strap 25 may be in excess or insufficient compared to the actual amount used.

[0113] In this embodiment, a biasing force weaker than the tension of the upper and lower wrapper straps 25 and 35 squeezed by the binding means 50 is applied to the dancer roller 43, so when the binding means 50 starts squeezing the upper and lower wrapper straps 25 and 35 during the binding period, the dancer roller 43 moves according to that tension, and as a result, the tension of the upper wrapper strap 25 downstream of the upper feed roller 27' is adjusted. In other words, if any slack occurs in the upper wrapper strap 25 downstream of the upper feed roller 27', it is absorbed (FIG. 5(D)), or if there is a shortage (over-tightening), the dancer roller 43 moves to unwind it (FIG. 5(C)).

[0114] Returning to Fig. 8, at the timing of 240° of the binding process cycle, the "torque control timing" becomes "torque control off". In other words, at this timing, the control means 60 outputs a control command different from the third torque command (including the third control command) to the lower servo motor 34. This control command is, for example, the same as the second' control command (100% torque, rotation speed "0"). This causes the pulling out of the lower wrapper strap 35 to stop.

[0115] At the timing of bundling process cycle 271° (the timing after "torque control off"), the sealer 51 is closest and seals the upper and lower cable ties 25 and 35, which are the excess lengths of the wrap, and in the period up to bundling process cycle 307° (for example, at the timing of bundling process cycle 307°), the sealed portion is cut to separate the single bundling group XA1.

[0116] At the timing of 280° of the binding process cycle, the "upper wrapper strap adjustment" is set to "no adjustment", that is, the adjustment by the adjustment means 40 is turned off.

[0117] Thereafter, at the timing of 307° in the bundling process cycle, the upper and lower sealers 51 start to move in directions away from each other.

[0118] At the timing of 320° of the binding process cycle, the “lower servo feed” is “feeding in progress”, that is, the lower servo motor 34 feeds the lower wrapper strap 35 of the second length L2 toward the binding position N based on the second control command.

[0119] Thus, in this embodiment, before the binding period, the upper wrapper strap 25 is supplied with an arbitrary first length L1' (for example, approximately half the length of the waist circumference of a set of article groups XA1) depending on the movement of the group of articles XA1, and the lower wrapper strap 35 is supplied with a second length L2 that is shorter than half the waist circumference, resulting in a shortage of wrapper strap for binding the group of articles XA1. In this embodiment, with the supply of the upper wrapper strap 25 stopped during the binding period, the lower servo motor 34 is controlled to generate a torque weaker than the tension of the upper wrapper strap 25 and the lower wrapper strap 35 by the binding means 50 (torque of 10% of the command value in this example).

[0120] This allows the torque of the lower servo motor 34 to be overcome by the tension of the upper cable tie 25 and the lower cable tie 35, allowing the lower cable tie 35 to be pulled out (compensated) by the missing length Lx' until the upper sealer 51A and the lower sealer 51B complete sealing.

[0121] The adjustment means 40 is configured to function at least during the binding period. When the adjustment means 40 functions (is turned on), the biasing means 44 biases the dancer roller 43 with a biasing force weaker than the tension of the upper wrapper strap 25 and the lower wrapper strap 35 squeezed by the binding means 50. Therefore, even if the supply of the upper wrapper strap 25 is stopped by the wrapper strap holding means 28, the dancer roller 43 can adjust the tension of the upper wrapper strap 25 downstream of the upper feed roller 27' to absorb slack in the upper wrapper strap 25 or pay out the insufficient amount.

[0122] As a result, each group of articles XA1 can be bound reliably along its outer shape without loosening or over-tightening. In the case of the second embodiment, a binding device 100 can be provided that can flexibly respond to changes in the outer shape of the group of articles XA1, particularly changes in the number of articles (e.g., number of pieces) that make up the group of articles XA1.

[0123] In the above embodiment, the first length L1 of the upper cable tie 25 is set to a predetermined amount that is approximately 1 / 2 the circumference of the article group XA1, but the first length L1 in the first control command may be adjusted each time, for example, by feedback control of the length of the upper cable tie 25 actually used for binding.

[0124] Also, the upper servo motor 24 may be configured to compensate for the insufficient amount of binding (insufficient length Lx) during the binding period. That is, the upper servo motor 24 may be controlled to generate a torque (torque of a command value of 10% in this example) weaker than the tension of the upper wrapper strap 25 and the lower wrapper strap 35 squeezed by the binding means 50 during the binding period. In this case, the lower servo motor 34 may be configured to stop supplying the lower wrapper strap 35 (configuration in which the top and bottom are reversed in the above embodiment), or the lower servo motor 34 may also be configured to compensate for the insufficient amount of binding. In this case, the adjustment means 40 may not be provided.

[0125] In addition, in the above embodiment, the first length L1 is approximately 1 / 2 the circumference of the article group XA1, but the first length L1 may be any predetermined amount required for binding, and may be longer or shorter than approximately 1 / 2 the circumference of the article group XA1.

[0126] In the above embodiment, the first cable tie supplying device 20 may be a lower cable tie supplying device, and the second cable tie supplying device 30 may be an upper cable tie supplying device. For example, the transport path 11 may be configured to extend in a (substantially) vertical direction, and the first cable tie supplying device 20 and the second cable tie supplying device 30 may be disposed on the left and right sides of the transport path 11.

[0127] As described above, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and technical concept of the present invention. [Explanation of symbols]

[0128] 100 Binding device 10. Means of transportation 11 Transport path 11A Slide 13 Chain 14 Transport finger 14A Front Finger 14B Rear Finger 16 Sprockets 20 Upper strap supply device 21 Original roll support section 22 Laura 23 Upper strap feed means 24 Upper servo motor 25 Upper cable tie 30 Lower cable tie supply device 31 Original roll support section 33 Lower strap feed means 34 Lower servo motor 35 Lower cable tie 40 Adjustment means 43 Dancer Lola 44 Actuation means 50 Binding means 51 Sealer 60 Control Means XA1 Article group

Claims

1. A conveying means for moving a group of articles on a conveying path; a first strapping band feeding means having a first servo motor and configured to feed a first strapping band to a strapping position provided in the middle of the conveying path; a second strap feed means having a second servo motor and configured to feed a second strap to the strapping position; a binding means for wrapping the first and second wrap straps around the group of articles transported to the binding position and sealing the excess length of the wrap to bind the group of articles; A control means, The control means, for each of the item groups, outputting a first control command including a first torque command to the first servo motor to feed the first strapping strap of a first length from the first strapping strap feeding means; outputting a second control command including a second torque command to the second servo motor to feed the second strap from the second strap feeding means a second length shorter than the first length; A control is performed to output a command to the second servo motor to reduce torque during a period from the start to the completion of the sealing by the bundling means (hereinafter referred to as a "bundling period"). A binding device characterized by:

2. A conveying means for moving a group of articles on a conveying path; a first wrapper band feeding means having an adjustment means and configured to feed a first wrapper band to a binding position provided in the middle of the conveying path; a second strap feed means having a servo motor and configured to feed a second strap to the strapping position; a binding means for wrapping the first and second wrap straps around the group of articles transported to the binding position and sealing the excess length of the wrap to bind the group of articles; A control means, The control means, for each of the item groups, outputting a control command including a torque command to the servo motor to feed the second strap from the second strap feeding means; A control is performed to output a command to the servo motor to reduce torque during a period from the start to the completion of the sealing by the bundling means (hereinafter referred to as a "bundling period"). A binding device characterized by:

3. The second length is less than half the bundled perimeter of the set of articles.

2. The binding device according to claim 1.

4. During the binding period, tension is applied to the first and second binding straps wound around the group of articles by the binding means, The control means outputs a command to generate a torque weaker than the tension as the command to reduce the torque.

3. The binding device according to claim 1 or 2.

5. An adjustment means for adjusting the tension of the first strap at least during the strapping period is provided.

2. The binding device according to claim 1.

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