Bag-making machine and bag-making method

Abstract

To correct deviation between two barrel materials so that one of the barrel material will not get too much load.SOLUTION: In a bag making machine, based on outputs from a sensor for detection of a mark of a first barrel material and a sensor for detection of a mark of a second barrel material, the first barrel material is corrected in the width direction on the basis of the second barrel material. Also, in the bag making machine, based on these sensor outputs, the second barrel material is corrected in the route direction on the basis of the first barrel material. In the bag making machine, the correction in the width direction is run by twisting a feed path of the first barrel material in a part section. In the bag making machine, the correction in the route direction is run by changing the length of the feed path of the second barrel material.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This application relates to a bag-making machine and a bag-making method for manufacturing bags from at least two web-shaped body materials, and particularly relates to the correction of relative displacement in the width direction and the longitudinal direction between the body materials.

Background Art

[0002] Bag-making machines and bag-making methods typically feed two web-shaped body materials in their longitudinal direction, overlap the body materials being fed, perform processing such as heat sealing on the body materials, and cross-cut the body materials in the width direction to manufacture bags.

[0003] When patterns are attached to the two body materials by printing or the like, it is important to align the patterns so that they match each other between the two body materials. Such alignment includes two types: alignment in the path direction (the longitudinal direction of the body material) along the feeding path of the body material and alignment in the width direction (the width direction of the body material) perpendicular to the path direction. For accurate alignment, when a displacement occurs in the width direction and / or the path direction between the body materials, this is corrected.

[0004] Patent Document 1 discloses correcting the displacement between the body materials in the path direction and the width direction by detecting marks attached to the body materials with a sensor such as a camera and performing the correction based on the detection.

[0005] Specifically, the bag-making machine of Patent Document 1 includes an ear-aligning roll disposed upstream of the position where the upper body material and the lower body material are overlapped with each other, and the upper body material is engaged with the ear-aligning roll. Then, the bag-making machine calculates the relative displacement amount in the width direction between the two body materials based on the mark detection, and tilts the ear-aligning roll from the horizontal state by a rotation amount corresponding to the calculated displacement amount. Thereby, the bag-making machine moves the upper body material with respect to the lower body material to correct the relative displacement in the width direction.

[0006] The bag-making machine described in Patent Document 1 further includes a printing alignment roll positioned upstream of the point where the upper and lower body materials overlap each other, with the upper body material engaged with the printing alignment roll. The bag-making machine then determines the relative displacement in the path direction between the two body materials based on mark detection, and moves the printing alignment roll linearly by a displacement corresponding to the determined displacement. In this way, the bag-making machine changes the feed path length of the upper body material, moves the upper body material relative to the lower body material, and corrects the relative displacement in the path direction. Thus, the bag-making machine described in Patent Document 1 corrects the relative displacement in two directions by moving the upper body material with respect to the lower body material.

[0007] In particular, regarding the correction of misalignment in the width direction, the bag-making machine described in Patent Document 1 forcibly tilts the selvage roller, causing uneven tension in the width direction of the upper body material, and causing the upper body material to slide on the selvage roller, resulting in a large load on the upper body material.

[0008] As described above, in the bag-making machine of Patent Document 1, when correcting misalignment, a large load may be applied to only one of the body members (upper body member). [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2008-100467 [Overview of the Initiative]

[0010] This application provides a bag-making machine for manufacturing bags from at least a web-shaped first body material and a web-shaped second body material. The aforementioned bag-making machine, A feeding device for feeding the first and second body members in their longitudinal direction, A superimposing member for overlapping the first and second body members, Upstream from the overlapping member, a first correcting member is provided that engages with the first body member but does not engage with the second body member, and a first actuator is provided for moving the first correcting member, and a correction mechanism is provided that moves the first correcting member to cause twisting of the feed path of the first body member in a portion section including the first correcting member. Upstream from the overlapping member, a second correcting member is provided which engages with the second body member but does not engage with the first body member, and a second actuator is provided for moving the second correcting member, and a second correction mechanism is provided which moves the second correcting member to change the feed path length of the second body member. A first sensor for detecting marks repeatedly applied to the first body material, A second sensor for detecting marks repeatedly applied to the second body material, The system comprises a controller for controlling the first and second actuators, The aforementioned controller, The first actuator is activated based on the outputs from the first and second sensors to correct the widthwise misalignment of the first body material relative to the second body material that is perpendicular to the feed path. The second actuator is configured to act based on the outputs from the first and second sensors in order to correct the misalignment of the second body member relative to the first body member in the path direction.

[0011] The first correction mechanism may include two meandering correction rollers arranged parallel to each other as the first correction member, and the first actuator may be configured to rotate the two meandering correction rollers in the same plane.

[0012] The second correction mechanism may include a pitch correction roller as the second correction member, and may be configured to move the pitch correction roller linearly in a direction perpendicular to the axis of the pitch correction roller by the second actuator.

[0013] The aforementioned controller, Based on the outputs from the first and second sensors, the relative displacement of the first body member with respect to the second body member in the width direction is determined, a first control signal indicating the amount of operation of the first actuator is generated based on the relative displacement in the width direction, and the first control signal is transmitted to the first actuator. The system may be configured to determine the relative displacement of the second body material with respect to the first body material in the path direction based on the outputs from the first and second sensors, generate a second control signal indicating the amount of operation of the second actuator based on the relative displacement in the path direction, and transmit the second control signal to the second actuator.

[0014] The feeding device is configured to intermittently feed the first and second drum members. The first and second sensors may be arranged to detect the marks on the first and second body members each time the intermittent feed is temporarily paused.

[0015] The aforementioned controller, The system may be configured to determine the relative displacement in the width direction / path direction each time intermittent feeding is paused, and to generate the first control signal / second control signal to be used in the next intermittent feeding based on the relative displacement.

[0016] The aforementioned controller, The first control signal and the second control signal may be configured to generate based on the average value of the relative displacement amounts in the width direction and the path direction, which are determined over multiple intermittent feeds.

[0017] The aforementioned controller, The feeder may be configured to adjust the pitch amount of intermittent feeding based on the output from either the first sensor or the second sensor.

[0018] The aforementioned controller, Based on the output from either the first sensor or the second sensor, determine the deviation amount of the mark from a predetermined reference position during the temporary stop of the intermittent feed, Based on the determined deviation amount, determine the pitch amount, The feeding device may be configured to control the feeding of the first and second body members by the determined pitch amount.

[0019] The controller, May be configured to adjust the pitch amount based on the output from the first sensor.

[0020] The bag-making machine further includes, A processing device for processing the first body member and / or the second body member, An additional sensor provided downstream of the first and second sensors and upstream of the processing device for detecting the mark on the first body member, The controller, May be configured to adjust the pitch amount of the intermittent feed by the feeding device based on the output from the additional sensor.

[0021] The present application also provides a bag-making method for manufacturing a bag from at least a web-like first body member and a web-like second body member, The bag-making method includes, Feeding the first and second body members in their longitudinal directions by a feeding device, Overlapping the first and second body members with each other by an overlapping member, The controller determines the relative deviation amount in the width direction perpendicular to the path direction of the first body member with respect to the second body member based on the outputs from the first sensor and the second sensor, The controller determines the relative deviation amount in the path direction of the second body member with respect to the first body member based on the outputs from the first and second sensors, The first sensor is provided to detect marks repeatedly attached to the first body member, The second sensor is provided to detect marks repeatedly applied to the second body material, The aforementioned bag-making method further includes, The controller operates the first actuator based on the amount of deviation in the width direction to move the first correction member, thereby causing twisting in the feed path of the first body member in a portion of the section including the first correction member, and correcting the first body member in the width direction with respect to the second body member, and The controller operates a second actuator based on the amount of deviation in the path direction to move a second correction member, thereby changing the feed path length of the second body member, and correcting the second body member in the path direction with respect to the first body member. The first corrective member is positioned upstream of the overlapping member and is configured to engage with the first body member but not with the second body member. The second corrective member is positioned upstream of the overlapping member and engages with the second body member, but is configured not to engage with the first body member. [Brief explanation of the drawing]

[0022] [Figure 1] Figure 1 shows a schematic representation of an example bag-making machine. [Figure 2] Figures 2A and 2B are views taken along the line k in Figure 1, illustrating the first modification mechanism, respectively, while Figure 2C is an enlarged view of region T in Figure 2B. [Figure 3] Figure 3 is a schematic diagram illustrating the first modification mechanism as an example. [Figure 4] Figure 4 is a schematic diagram illustrating the second modification mechanism as an example. [Figure 5] Figures 5A and 5B illustrate the marks applied to the body material. [Figure 6] Figure 6 is a block diagram illustrating an example of a bag-making machine for misalignment correction. [Figure 7] Figures 7A and 7B illustrate the correction of relative displacement in the width direction and relative displacement in the path direction, respectively. [Figure 8]Figure 8 illustrates the information displayed on the screen of the display device. [Figure 9] Figure 9 schematically shows an example of a movement mechanism for moving a sensor. [Figure 10] Figure 10 illustrates an example where the mark (part of the detected printed pattern) is misaligned between cylinder materials. [Figure 11] Figure 11 schematically shows another example of a bag-making machine. [Modes for carrying out the invention]

[0023] Embodiments of the present application will be described below with reference to the drawings. The following are merely illustrative examples of the present application. The drawings are schematic and may not be drawn to exact size. It should also be understood that the same reference numerals are used throughout the drawings to represent identical or similar components.

[0024] Figure 1 schematically shows an example bag-making machine. Two raw material rolls 10' and 11' are positioned at the upstream end of the bag-making machine. The raw material rolls 10' and 11' are formed by winding web-like (continuous) body materials 10 and 11 into rolls. The body materials 10 and 11 may be, for example, plastic films. The film may be a single-layer film (monomaterial film) or a multi-layer film (composite material film). The body materials 10 and 11 may also consist of a paper base and a resin applied partially or entirely to the base. Single-layer films (monomaterial films) are easily recyclable and are being re-evaluated from the perspective of SDGs such as environmental protection.

[0025] The bag-making machine is equipped with a feeding device 20. The feeding device 20 is equipped with at least one pair of drive rollers 200, 201 and is configured to intermittently feed the body materials 10, 11 in their longitudinal direction. The feeding direction is indicated by the symbol +X. The body materials 10, 11 may be fed by only the pair of drive rollers 201. Alternatively, one or more pairs of drive rollers 200 may be added, taking into consideration the elasticity of the body materials 10, 11.

[0026] The bag-making machine further includes two dancer rollers 21 and a pair of overlapping rollers 22 as overlapping members. The bag-making machine feeds the body members 10 and 11 from the raw rolls 10' and 11' respectively, feeding them continuously in a separated vertical position, passing them through the dancer rollers 21, and then through the pair of overlapping rollers 22. The dancer rollers 21 are moved by appropriate actuators (not shown), as is well known, to convert the feeding of the body members 10 / 11 from continuous feeding to intermittent feeding. When the body members 10 and 11 pass through the pair of overlapping rollers 22, they are overlapped by the pair of overlapping rollers 22 at the position of the pair of overlapping rollers 22. Therefore, the body members 10 and 11 are fed intermittently in the section downstream of the dancer rollers 21, that is, they alternate between feeding and pausing.

[0027] The bag-making machine further includes at least one processing device 23 located downstream of the overlapping roller pair 22 for processing the body materials 10 and 11. The processing device 23 is, for example, a heat sealing device. The heat sealing device heat-seals the body materials 10 and 11 in the widthwise and longitudinal directions using, for example, a heat sealing bar, with each intermittent feed, so that the manufactured bag 1 has a sealed portion along its perimeter (three sides).

[0028] The bag-making machine further includes a cross-cutting device 24 located downstream of the processing device 23. The cross-cutting device 24 uses, for example, a cutter to cross-cut the body materials 10 and 11 in the width direction with each intermittent feed, thereby sequentially manufacturing bags 1. Bags 1 are manufactured from the portions removed by the cross-cutting. Therefore, bag 1 comprises at least two body materials that are opposite each other.

[0029] Instead of the example in Figure 1, as disclosed in Patent Document 1, the bag-making machine may form the body members 10 and 11 by slitting a web taken from a large roll of raw material along its longitudinal direction. In addition, the bag-making machine may manufacture the bag 1 by incorporating auxiliary components such as a bottom gusset, side gusset material, and a zipper in addition to the body members 10 and 11.

[0030] The bag-making machine further includes a first correction mechanism 3, a second correction mechanism 4, and two sensors 5 and 6.

[0031] The first correction mechanism 3 comprises two meandering correction rollers 30a and 30b arranged parallel to each other and spaced apart in the feeding direction of the body material 10 upstream of the overlapping roller pair 22, and a plate-shaped support 31 that rotatably supports these rollers 30a and 30b.

[0032] Both the meandering correction rollers 30a and 30b engage with the body material 10 but are positioned so as not to engage with the body material 11. The meandering correction roller 30a is the upstream roller, and the meandering correction roller 30b is the downstream roller.

[0033] Figure 2A is a view taken along line k in Figure 1. As shown in Figure 2A, the support 31 is rotatably mounted on the fixed frame (not shown) of the bag-making machine around axis AX. Axis AX is set in the central part, near the upstream meandering correction roller 30a.

[0034] The first correction mechanism 3 includes a first actuator 32 for rotating the meandering correction rollers 30a and 30b integrally around axis AX within a small angular range in the same plane. The first actuator 32 is fixed to a fixed frame and connected to a support 31. When the first actuator 32 is actuated, the meandering correction rollers 30a and 30b and the support 31 rotate within the plane of the plate-shaped support 31. The direction of rotation is indicated by the signs +R and -R.

[0035] For example, the first actuator 32 is a known feed screw mechanism consisting of a feed screw (such as a trapezoidal screw) including a screw shaft and a nut, and a motor (such as a servo motor, stepping motor, or induction motor) for rotating the screw shaft to move the nut along the screw shaft. The screw shaft is fixed to a fixed frame, and the movable nut is directly or indirectly attached to the support 31. The amount of rotation of the compensating rollers 30a, 30b (support 31) can be controlled by controlling the rotation of the screw shaft via the motor.

[0036] As shown in Figure 2B, another example of the first correction mechanism 3 comprises a plurality of first actuators 32, which are arranged on a virtual circle centered on axis AX, fixed to a fixed frame, and connected to a support 31. Each first actuator 32 is a linear actuator and is oriented to act over a small distance in the tangential direction of the virtual circle (see Figure 2C). The first correction mechanism 3 may be configured such that the meandering correction rollers 30a, 30b and the support 31 rotate together by the simultaneous operation of the plurality of first actuators 32.

[0037] The operating principle of the first correction mechanism 3 will be explained with reference to Figures 2A, 2B, and 3. In Figure 3, reference numeral 33a denotes the upstream guide roller, and reference numeral 33b denotes the downstream guide roller. The first correction mechanism 3 can correct the body material 10 to direction +Y near the downstream meandering correction roller 30b by rotating the support 31 in direction +R using the first actuator 32. The first correction mechanism 3 can also correct the body material 10 to direction -Y near the meandering correction roller 30b by rotating the support 31 in direction -R using the first actuator 32. Directions +Y and -Y are defined based on a plan view of the bag-making machine and the feed direction +X (the same applies hereafter). Directions +Y and -Y are width directions perpendicular to the feed path of the body material 10.

[0038] In other words, the first correction mechanism 3, through the rotation of the rollers 30a and 30b, causes a slight twist in the feed path of the body material 10 in a section including the rollers 30a and 30b (the section upstream of the stacked roller pair 22). As a result, the first correction mechanism 3 slightly twists the body material 10 while it is being transported in that section, and corrects the trajectory by moving the position of the body material 10 (the position of its edge) in the width direction relative to the body material 11.

[0039] In Figure 3, when the meandering correction rollers 30a and 30b (support 31) are in the neutral position, it is desirable that the body material 10 be flat in the first section between roller 33a and roller 30a, the second section between roller 30a and roller 30b, and the third section between roller 30b and roller 33b. When the meandering correction rollers 30a and 30b (support 31) rotate, twisting occurs in the feed path in a portion of the first to third sections, resulting in the body material 10 twisting and becoming uneven in the first and third sections. However, since the amount of rotation (and therefore the amount of twisting) required to correct the following misalignment is minute, the tension distribution in the width direction of the body material 10 is almost uniform, and the load on the body material 10 does not become excessive.

[0040] Depending on the specific configuration of the first correction mechanism 3, for example, if the first correction mechanism 3 is configured to allow the meandering correction rollers 30a, 30b (support 31) to rotate at an angle of about 0.5°, it is sufficient to correct the deviation in the width direction.

[0041] As shown in Figure 1, the second correction mechanism 4 includes a pitch correction roller 40 as a second correction member. The pitch correction roller 40 engages with the body member 11 upstream of the overlapping roller pair 22, but is positioned so as not to engage with the body member 10.

[0042] As shown in Figure 4, the operating principle of the second correction mechanism 4 is explained. The second correction mechanism 4 includes a second actuator 41 used to control the position of the body material 11 in the transport direction. The second actuator 41 is connected to the pitch correction roller 40. When the second actuator 41 is operated, the pitch correction roller 40 moves linearly in a direction perpendicular to its axis. Note that in Figure 4, reference numeral 42a indicates the upstream guide roller, and reference numeral 42b indicates the downstream guide roller.

[0043] For example, the second actuator 41 may be a known lead screw mechanism consisting of a lead screw (including a screw shaft and a nut) and a motor, similar to the first actuator 32. The lead screw mechanism is configured such that when the screw shaft is rotated by the motor, the nut and the corrective pitch roller 40 attached thereto move linearly in the axial direction of the screw shaft. The amount of movement of the pitch corrective roller 40 can be controlled by controlling the rotation of the screw shaft via the motor.

[0044] When the second correction mechanism 4 moves the pitch correction roller 40 closer to the guide rollers 42a and 42b using the second actuator 41, the length of the feed path of the body material 11 is shortened. On the other hand, when the second correction mechanism 4 moves the pitch correction roller 40 further away from the guide rollers 42a and 42b using the second actuator 41, the length of the feed path of the body material 11 is lengthened.

[0045] In this way, the second correction mechanism 4 changes the feed path length of the body material 11 by moving the pitch correction roller 40. Therefore, the second correction mechanism 4 is configured to correct the body material 11 by moving it in the path direction (direction +X and direction -X (Figure 5A, etc.)) relative to the body material 10. This principle itself is the same as that in Patent Document 1.

[0046] As shown in Figure 1, sensors 5 and 6 are located downstream of the stacking roller pair 22. That is, both sensors 5 and 6 are located in the section where the body members 10 and 11 are being fed intermittently. Sensor 5 is positioned to detect the mark 100 (Figure 5A) attached to the body member 10 during a temporary pause in intermittent feeding. Second sensor 6 is positioned to detect the mark 110 (Figure 5B) attached to the body member 11 during a temporary pause in intermittent feeding. In this example, both sensors 5 and 6 are cameras.

[0047] Figure 5A shows the upper surface of the upper body material 10. In this example, the mark 100 is applied to the upper surface of the upper body material 10 by printing or other means, repeating in the longitudinal direction at a predetermined pitch. Figure 5B shows the lower surface of the lower body material 11. The mark 110 is applied to the lower surface of the body material 11 by printing or other means, repeating in the longitudinal direction. The marks 100 / 110 may be part or all of the pattern 101 / 111 that is applied to the body material 10 / 11 by printing or other means. Also, the shapes and positions of the marks 100 and 110 may be the same or different from each other.

[0048] As shown in Figure 6, the bag-making machine further includes a controller 7. Sensors 5 and 6 and actuators 32 and 41 are connected to the controller 7. Outputs from sensors 5 and 6 are sent to the controller 7. The controller 7 generates control signals based on the outputs from sensors 5 and 6 and transmits them to actuators 32 and 41 to control them as described later. The controller 7 includes one or more processors. The controller 7 performs the following control by having one or more processors execute a program stored in a storage medium (not shown).

[0049] Controller 7 has positional information of sensors 5 and 6 on the bag-making machine. Based on the outputs from sensors 5 and 6, Controller 7 determines the amount of deviation of body material 10 from the reference position and the amount of deviation of body material 11 from the reference position. Based on these, Controller 7 determines the relative deviation of body material 10 relative to body material 11 in the width direction (+Y, -Y) and the relative deviation of body material 11 relative to body material 10 in the path direction (+X, -X). These relative deviations are quantities that indicate not only magnitude but also direction, for example, by positive or negative values.

[0050] Here, the "reference position" is the position where, when the detected marks 100 and 110 are in that position during a temporary pause in intermittent feeding, the bag-making machine can produce a bag 1 in which the patterns 101 and 111 are perfectly aligned with each other. The reference position is known, and the controller 7 has this information. In this example, since sensors 5 and 6 are cameras, the controller 7 processes the output from the sensors (video or still image data) in a well-known way to determine the amount of deviation of the body material 10 and 11 from the reference position. In reality, it is difficult to align the patterns 101 and 111 to a perfectly aligned position, so the amount of deviation of the patterns 101 and 111 from the aligned position can be measured and this amount of deviation can be set as an "offset" value to control the machine so that the patterns 101 and 111 are aligned.

[0051] Furthermore, if the controller 7 can detect the relative displacement between the body materials 10 and 11 based on its output, sensors 5 and 6 may be other sensors, such as line sensors, instead of cameras. Line sensors may be used if the marks 100 and 110 are marks with clear boundaries, such as registration marks. If the patterns 101 and 111 do not include parts with clear boundaries, such as registration marks, the controller 7 may measure part or all of the patterns 101 and 111 as marks 100 and 110 using the output of sensors 5 and 6 (cameras) and a pattern search algorithm, and determine the relative displacement between the body materials 10 and 11 based on the measurement results.

[0052] Next, the controller 7 controls the first correction mechanism 3 (first actuator 32, its motor in the above example) to move the body member 10 relative to the body member 11 to correct the misalignment in the width direction. The amount of rotation of the first meandering correction rollers 30a, 30b (support 31) required to cancel the determined relative misalignment in the width direction, and therefore the amount of operation of the first actuator 32 corresponding to the amount of rotation, is determined based on the relative misalignment in the width direction, the known structure of the first correction mechanism 3 (distance between meandering correction rollers 30a, 30b, design of the support 31), etc. Note that the amount of rotation and the amount of operation are quantities that indicate magnitude and direction. Therefore, the controller 7 can determine the amount of operation required to cancel the misalignment from the relative misalignment in the width direction, etc.

[0053] In other words, the controller 7 generates a first control signal indicating the amount of operation of the first actuator 32 necessary to correct the misalignment, based on the calculated relative misalignment in the width direction, and transmits it to the first actuator 32. The first actuator 32 responds to the receipt of the first control signal by operating with the specified amount, rotating the meandering correction rollers 30a, 30b (supports 31). As a result, the body member 10 is moved relative to the body member 11, and the relative misalignment in the width direction is corrected with respect to the body member 11.

[0054] Figure 7A is an enlarged plan view of the body member 10 at the position of sensor 5. For example, if the controller 7 determines, based on the mark detection described above, that the body member 10 is misaligned with respect to the body member 11 by a distance D1 in the direction +Y, the first actuator 32 rotates the support 31 in the direction -R (see Figures 2A and 2B). As a result, the body member 10 is moved relative to the body member 11 in the direction -Y, and the relative misalignment in the width direction is corrected (the misalignment distance D1 is reduced).

[0055] On the other hand, if the controller 7 determines that the body member 10 is shifted in the opposite direction -Y relative to the body member 11, the first actuator 32 rotates the support 31 in the direction +R. As a result, the body member 10 is moved in the direction +Y relative to the body member, and the relative shift in the width direction is corrected.

[0056] Simultaneously, the controller 7 controls the second correction mechanism 4 (the second actuator 41, its motor in the above example) to move the body member 11 relative to the body member 10, thereby correcting the misalignment in the path direction. The amount of movement of the pitch correction roller required to cancel the determined relative misalignment in the path direction, and therefore the amount of operation of the second actuator 41 corresponding to that movement, is determined based on the relative misalignment in the path direction, the known structure of the second correction mechanism 4, the feed path near the pitch correction roller 40, etc. Note that the amount of movement is also a quantity that indicates magnitude and direction. Therefore, the controller 7 can determine the amount of operation required to cancel the misalignment from the determined misalignment in the path direction, etc.

[0057] Specifically, the controller 7 generates a second control signal indicating the amount of movement of the second actuator 41 required to correct the misalignment, based on the determined relative misalignment in the path direction, and transmits it to the second actuator 41. The second actuator 41 acts with the specified amount of movement in response to receiving the second control signal, causing the pitch correction roller 40 to move linearly. As a result, the body member 11 is moved relative to the body member 10, and the relative misalignment in the path direction is corrected with respect to the body member 10.

[0058] Figure 7B is an enlarged bottom view of the body material 11 at the position of the sensor 6. For example, if the controller 7 determines, based on the mark detection described above, that the body material 11 is shifted relative to the body material 10 by a distance D2 and in the direction +X, the second actuator 41 moves the pitch correction roller 40 so that the length of the feed path of the body material 11 increases (the pitch correction roller 40 is moved downward in Figure 4). This corrects the shift in the path direction (the shift distance D2 decreases when the next intermittent conveyance is paused).

[0059] On the other hand, if the controller 7 determines that the body material 11 is shifted relative to the body material 10 by a distance D2 in the opposite direction -X, the second actuator 41 moves the pitch correction roller 40 to shorten the feed path length of the body material 11 (in Figure 4, the pitch correction roller 40 is moved upward). This corrects the relative shift in the path direction.

[0060] Furthermore, the controller 7 may calculate the relative deviation in the width direction / path direction each time intermittent feeding is paused, generate first / second control signals, and reflect the above-mentioned width direction / path direction deviation correction in the next intermittent feeding.

[0061] Alternatively, the controller 7 may, each time intermittent feeding is paused, determine the amount of deviation in the width direction / path direction, calculate the average value of the relative deviation amounts in the width direction / path direction over the most recent series of intermittent feedings, and generate first / second control signals based on this average value to perform the above-mentioned width direction / path direction deviation correction.

[0062] As described above, even if a relative misalignment occurs between the body materials 10 and 11, it is automatically and immediately corrected. Therefore, downstream of the overlapping roller pair 22, the handles 101 and 111 align with each other with high precision, and as a result, the handles of the finished bag 1 also align with high precision.

[0063] Patent Document 1 applies tension to only one of the body members to correct relative misalignment in two directions, thus placing a large load on that one body member. In particular, creating a tension gradient in the width direction of the body member places a large load on the body member. On the other hand, in the embodiment, as described above, the relative misalignment in the width direction is corrected with respect to the other body member 11 by slightly twisting one body member 10, and the relative misalignment in the path direction is corrected with respect to the one body member 10 by adjusting the path length of the other body member 11. In particular, the slight twisting of the body member 10 as in the embodiment places virtually no load on the body member compared to Patent Document 1. Therefore, the embodiment does not place an excessive load on either of the body members.

[0064] More specifically, the configuration of Patent Document 1 forcibly generates varying (uneven) tension in the width direction and slides the body material in the width direction on the edge-aligning roll, thus placing a large load on the body material. On the other hand, as shown in Figures 2A and 2B, the embodiment corrects the relative misalignment in the width direction of the body materials 10 and 11 by the first correction mechanism 3 which twists the body material 10 at a small angle, without forcibly applying tension in the width direction of the body material 10 or forcibly sliding it on the roller. Therefore, the embodiment can correct the misalignment in the width direction with almost no load on the body material compared to Patent Document 1.

[0065] Thus, this embodiment does not impose an excessive load on only one of the body materials, and corrects the misalignment in the width direction with a lighter load than that described in Patent Document 1. Therefore, it is particularly preferable to apply this embodiment to bag making using monomaterial body materials 10 and 11, which have higher stretchability than laminate film.

[0066] The method for correcting misalignment in the width direction described in Patent Document 1 generates uneven tension in the width direction of the body material by forcibly tilting the selvage roll. In other words, it creates a tension difference by changing the length in the path direction at both ends of the body material. This tension difference is proportional to the driving force required to shift the upper body material in its width direction (axis direction of the selvage roll) on the selvage roll. When comparing laminate film material with monomaterial material such as polyethylene or polyester, if the tilt angle of the selvage roll is the same, the amount of change in the length in the path direction at both ends of the body material will also be the same, and the tension difference will be larger for laminate film material with a low expansion ratio (high Young's modulus). Conversely, the tension difference will not be so large for monomaterial material with a high expansion ratio (low Young's modulus). Therefore, the responsiveness of the method in Patent Document 1 for correcting misalignment in the width direction is poor.

[0067] In contrast, the embodiment directly moves the edge position of the drum body 10 by rotating the support 31 by a minute angle, so the responsiveness is almost the same for laminate film material and monomaterial material. The embodiment can be said to be more suitable for monomaterial material than the above-mentioned correction method in Patent Document 1. Of course, adding extra tension to the drum body to correct misalignment is not good because it can lead to damage to the drum body. A method that does not add extra tension to the drum body, as in the embodiment, is suitable.

[0068] In this case, the first modification mechanism 3 was assigned to the upper body member 10 and the second modification mechanism 4 was assigned to the lower body member 11. Alternatively, the first modification mechanism 3 may be assigned to the lower body member 11 and the second modification mechanism 4 may be assigned to the upper body member 10.

[0069] Furthermore, in this embodiment, the controller 7 adjusts the pitch amount (intermittent feed amount) of the intermittent feed of the feeder 20 based on the output from sensor 5 (camera) or sensor 6 (camera), thereby correcting the deviation of the marks 100, 110 (printed patterns 101, 111) from their reference position (which is their absolute position on the bag-making machine) when the intermittent feed is paused. In other words, the embodiment corrects the absolute deviation in the path direction in addition to the relative deviation correction in the two directions mentioned above. For this purpose, as shown in Figure 6, the feeder 20 (and its drive rollers 200) is connected to the controller 7.

[0070] As described above, the controller 7 determines the amount of deviation of the mark 100 from the above-mentioned reference position in the path direction during the temporary suspension of intermittent feeding, based on the output from the sensor 5.

[0071] Then, based on the calculated deviation amount, the controller 7 determines the pitch amount for the next intermittent feed of the body material 10,11 by the drive roller 200 directly upstream of the processing device 23. More specifically, if the controller 7 determines that the mark 100 is located downstream of the reference position (meaning that the body material 10,11 is being fed in excess), it sets the pitch amount for the next intermittent feed to a value smaller than the set value (equivalent to one bag). On the other hand, if the controller 7 determines that the mark 100 is located upstream of the reference position (meaning that the body material 10,11 is being fed insufficiently), it sets the pitch amount for the next intermittent feed to a value larger than the set value.

[0072] Then, the controller 7 controls the drive roller 200 so that the body members 10 and 11 are fed by the calculated (adjusted) pitch amount in the next intermittent feed.

[0073] Correcting only the relative deviation in the path direction may not be sufficient, as deviations from the reference position in the path direction can accumulate. As described above, in addition to correcting the relative deviation, correction of the deviation from the reference position in the path direction is also applied. Therefore, if the sensor 5 and the drive roller 200 are positioned near the upstream of the processing device 23, the body materials 10 and 11 can be stopped with high precision at the design position relative to the processing device 23. In other words, the processing device 23 can process the body materials 10 and 11 with high precision, for example, by heat sealing in the path direction or in the width direction.

[0074] Thus, the embodiment uses the sensor 5 to correct not only the relative positional misalignment of the body members 10 and 11 in the width direction, but also the absolute positional misalignment of the body members 10 and 11 in the path direction, thus eliminating the need to install an additional sensor for correcting absolute positional misalignment.

[0075] Furthermore, the controller 7 may stop driving the drive roller 200 the moment a sensor 5, such as a line sensor, detects the mark 100 (a specific point on the handle 101), thereby temporarily suspending the transport of the body material 10, 11, and ensuring alignment between the mark 100 and the reference position. The mode of intermittent feed control (adjustment of pitch amount) is appropriately selected depending on the required precision and the design of the bag.

[0076] In addition, this intermittent feed control may be performed based on the output from the sensor 6 for the body member 11 instead of the sensor 5 for the body member 10. However, since the relative deviation in the path direction is corrected with respect to the body member 10, it is preferable that the intermittent feed control be performed using the output from the sensor 5 for the body member 10.

[0077] As shown in Figure 8, the bag-making machine may also be equipped with a display device 25. The display device 25 may display image data (video data) from the camera acting as sensor 5 / 6 in real time on its display screen 250. The controller 7 may use the position information of sensor 5 / 6 and the reference position to always superimpose and display the mark images RM1 / RM2 at the reference position. As a result, when intermittent feeding is temporarily paused, the actual marks 100 / 110 on the body material 10 / 11 and the mark images RM1 / RM2 are displayed on the display screen 250.

[0078] For accurate identification of the mark positions, it is preferable that marks 100 and 110 have high-contrast boundary lines on both sides. In particular, when line sensors are used as sensors 5 and 6, it is preferable that marks 100 and 110 have boundary lines parallel to the path direction in order to accurately determine the relative amount of deviation in the width direction.

[0079] Depending on the bag 1 being manufactured, the patterns 101 and 111 may differ between the body materials 10 and 11, and the positions of the marks 100 and 110 to be detected (parts of the high-contrast patterns 101 and 111) may differ between the body materials 10 and 11. In this case, the sensors 5 and 6 (cameras) may be placed in different positions rather than facing each other.

[0080] Therefore, in order to accommodate the manufacture of bags with various patterns, it is preferable that the sensors 5 and 6 (cameras) are provided so as to be movable in the width direction and the path direction. For example, as shown in Figure 9, a moving mechanism 26 may be provided for sensor 5. The moving mechanism 26 may be a known mechanism, for example, comprising two first frames 260 that are spaced apart in the width direction (+Y, -Y) and extend in the path direction (+X, -X), a second frame 261 that spans the first frames 260 and extends in the width direction to support sensor 5 (camera), a rack and pinion (not shown) that moves the second frame 261 and sensor 5 (camera) in the path direction on the first frame 260, and a linear actuator (not shown) that moves sensor 5 (camera) in the width direction on the second frame 261. A similar moving mechanism is provided for sensor 6.

[0081] The controller 7 can determine the positions of sensors 5 and 6 (cameras) based on signals from sensors such as those from the moving mechanism 26. As shown in Figure 10, even if sensors 5 and 6 (cameras) are shifted to different positions in order to manufacture bags 1 where the detected marks 100 and 110 (parts of the printed patterns 101 and 111) are different in the vertical and horizontal directions (see parts P5 / P6 captured by sensors 5 / 6 (cameras) in Figure 10), the controller 7 can accurately correct the relative displacement in the width direction and path direction based on information such as the position of sensors 5 and 6 (cameras) and reference position.

[0082] Such a moving mechanism 26 is particularly preferable when low-resolution sensors 5,6 (cameras) are used to image a field of view narrower than the size of one bag. If high-resolution sensors 5,6 (cameras) are fixedly positioned so that the size of one bag fits within the field of view, the moving mechanism 26 may not be necessary.

[0083] Another example of a bag-making machine shown in Figure 11 further includes an additional sensor 8 located downstream of sensors 5 and 6 and upstream of the processing device 23 to detect the mark 100 on the body material 10. The controller 7 may control the feed device 20 (drive roller 200) in any of the above-described control modes based on the output from the additional sensor 8, rather than the output from sensors 5 and 6, to correct the deviation of the mark 100 from the reference position. The additional sensor 8 may be positioned to detect the mark 110 on the body material 11, but as mentioned above, it is preferable to position it to detect the mark 100 on the body material 10. In this example as well, the accuracy of processing by the processing device 23 is improved.

[0084] Whether to use sensor 5 or add sensor 8 to correct the absolute positional deviation of the body materials 10 and 11 in the path direction depends on various requirements such as the number of processing steps, the size (length) of the bag-making machine, and the size of the bags to be manufactured. In any case, the method disclosed above enables high-precision positioning without placing excessive load on the body materials 10 and 11. [Explanation of symbols]

[0085] 1 bag 10,11 Body material 100,101 marks 20 Feeder 22. Overlapping roller pair (overlapping member) 23 Processing equipment 3 First correction mechanism 30a, 30b Meandering correction roller (first correction member) 32 First Actuator 4 Second correction mechanism 40 Pitch correction roller (second correction member) 41. Second Actuator 5,6 Sensors 7 Controllers 8. Additional sensors

Claims

1. A bag-making machine that manufactures bags from at least a web-like first body material and a web-like second body material, A feeding device for feeding the first and second body members in their longitudinal direction, A superimposing member for overlapping the first and second body members, Upstream from the overlapping member, a first correction mechanism comprising: a first correction member provided to engage with the first body member but not with the second body member; and a first actuator for moving the first correction member; A second correction mechanism comprising: a second correction member provided upstream of the overlapping member, which engages with the second body member but does not engage with the first body member; and a second actuator for moving the second correction member; A first sensor for detecting marks repeatedly applied to the first body material, A second sensor for detecting marks repeatedly applied to the second body material, The system comprises a controller for controlling the first and second actuators, The first correction mechanism includes, as the first correction member, two meandering correction rollers arranged at a distance from each other and parallel to each other in the feeding direction of the first body material, and is configured to move the first body material in the width direction perpendicular to the feeding path of the first body material by rotating the two meandering correction rollers integrally in the same plane about a predetermined axis using the first actuator. The second correction mechanism is configured to move the second correction member to change the feed path length of the second body member, The aforementioned controller, The first actuator is activated based on the outputs from the first and second sensors to correct the widthwise displacement of the first body member relative to the second body member. The second actuator is configured to be activated based on the outputs from the first and second sensors in order to correct the misalignment of the second body member relative to the first body member in the path direction. Bag making machine.

2. The first correction mechanism further includes a plate-shaped support that rotatably supports the two meandering correction rollers, The first actuator is connected to the support, The first correction mechanism is configured such that the first actuator rotates the two meandering correction rollers and the support within the plane of the support. The bag-making machine according to claim 1.

3. The second correction mechanism includes a pitch correction roller as the second correction member, and is configured to move the pitch correction roller linearly in a direction perpendicular to the axis of the pitch correction roller by the second actuator. The bag-making machine according to claim 1.

4. The aforementioned controller, Based on the outputs from the first and second sensors, the relative displacement of the first body member with respect to the second body member in the width direction is determined, a first control signal indicating the amount of operation of the first actuator is generated based on the relative displacement in the width direction, and the first control signal is transmitted to the first actuator. Based on the outputs from the first and second sensors, the system is configured to determine the relative displacement of the second body member relative to the first body member in the path direction, generate a second control signal indicating the amount of operation of the second actuator based on the relative displacement in the path direction, and transmit the second control signal to the second actuator. The bag-making machine according to claim 1.

5. The feeding device is configured to intermittently feed the first and second drum members. The first and second sensors are arranged to detect the marks on the first and second body members each time the intermittent feed is temporarily paused. The bag-making machine according to claim 4.

6. The aforementioned controller, Each time intermittent feeding is temporarily paused, the relative displacement in the width direction and the path direction is determined, and based on this relative displacement, the first control signal and the second control signal to be used in the next intermittent feeding are generated. The bag-making machine according to claim 5.

7. The aforementioned controller, The system is configured to generate the first control signal and the second control signal based on the average value of the relative displacement amounts in the width direction and the path direction, which are determined over multiple intermittent feeds. The bag-making machine according to claim 5.

8. The aforementioned controller, The system is configured to adjust the pitch amount of intermittent feeding by the feeder based on the output from either the first sensor or the second sensor. The bag-making machine according to claim 1.

9. The aforementioned controller, Based on the output from either the first sensor or the second sensor, the amount of deviation of the mark from a predetermined reference position during a temporary pause of intermittent feeding is determined. Based on the calculated amount of displacement, the pitch amount is determined, The feeding device is configured to control the feeding mechanism so that the first and second body members are fed according to the calculated pitch amount. The bag-making machine according to claim 8.

10. The aforementioned controller, The pitch amount is configured to be adjusted based on the output from the first sensor. The bag-making machine according to claim 8.

11. The aforementioned bag-making machine further, A processing apparatus for processing the first body material and / or the second body material, The system includes an additional sensor located downstream of the first and second sensors and upstream of the processing apparatus for detecting the marks on the first body material, The aforementioned controller, Based on the output from the additional sensor, the feeder is configured to adjust the pitch amount of the intermittent feed. The bag-making machine according to claim 1.

12. A bag-making method for manufacturing a bag from at least a web-like first body material and a web-like second body material, The aforementioned bag-making method is, The first and second body members are fed in the longitudinal direction by the feeding device. The first and second body members are stacked on top of each other by overlapping members, The controller determines the relative displacement of the first body material in the width direction perpendicular to the path direction relative to the second body material, based on the outputs from the first and second sensors. The controller includes the ability to determine the relative displacement of the second body material with respect to the first body material in the path direction based on the outputs from the first and second sensors, The first sensor is provided to detect marks repeatedly applied to the first body material, The second sensor is provided to detect marks repeatedly applied to the second body material, The aforementioned bag-making method further includes, The controller operates the first actuator based on the amount of deviation in the width direction to rotate the two meandering correction rollers, which serve as the first correction member, integrally within the same plane around a predetermined axis, thereby correcting the first body member in the width direction with respect to the second body member, and The controller operates a second actuator based on the amount of deviation in the path direction to move a second correction member, thereby changing the feed path length of the second body member, and correcting the second body member in the path direction with respect to the first body member. The two meandering correction rollers are positioned upstream of the overlapping member, engaging with the first body member but not with the second body member, and are spaced apart from and parallel to each other in the feeding direction of the first body member. The second corrective member is positioned upstream of the overlapping member and engages with the second body member, but is not provided to engage with the first body member. Bag making method.

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