JP2015024506A - Bag making machine and bag making method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bag making machine and a bag making method which require no drive parts or position detection parts arranged for processing parts, e.g. heat seal parts or cooling parts, and can prevent occurrence of product defects, e.g. seal deviation, by a simple configuration.SOLUTION: A bag making machine includes mark detection parts, e.g. a detection sensor 48, which are arranged in the upstream of individual processing parts in the conveyance direction of a belt-like film W and detect detection marks provided in each product pitch in the belt-like film W carried by a carriage part and a path length adjustment mechanism 50 which adjusts the path length of the film W between processing parts so that the path length of the film W between the processing parts matches a desirable length, on the basis of detection information on the detection marks from the mark detection parts.

Description

  The present invention relates to a bag making machine and a bag making method for producing a bag body from a belt-like film.

  2. Description of the Related Art Conventionally, various types of bag making machines for producing a bag (product) from a film such as a two-layer belt-like plastic film are known (see, for example, Patent Document 1). In a general bag making machine, a two-layer belt-like film is intermittently conveyed for each product pitch. Further, a plurality of movable units are arranged along the longitudinal direction of the film at intervals based on the product pitch (specifically, intervals having an integer multiple of the product pitch). Each is supported by a support member so as to be movable along the longitudinal direction of the film. Further, the bag making machine is equipped with a drive mechanism for each support member, and each movable unit can be moved by moving each support member by the drive mechanism.

  In a general bag making machine, a bag (specifically, a plastic bag) is manufactured by performing various treatments on the film by each movable unit. Specifically, a vertical heater, a vertical cooling member, a horizontal heater, a horizontal cooling member, and a cutter are used as the movable unit, and a bag is manufactured for each intermittent feed of the film.

  In the bag-making machine disclosed in Patent Document 1, it is possible to prevent a production abnormality due to intermittent feeding deviation of a film due to slipping, a certain amount of intermittent feeding deviation such as film elongation and product pitch deviation due to heat, and meandering during film conveyance. By detecting the meandering and pitch deviation of the film by a detection sensor such as a CCD camera, measuring the deviation amount, and moving each support member so as to automatically correct the position of each movable unit such as a heater and a cooling member Further, a technique for preventing the occurrence of product defects due to seal position deviation or the like is disclosed.

JP 2011-121220 A

  However, in the conventional bag making machine as disclosed in Patent Document 1 and the like, each support member that supports each movable unit such as a heater and a cooling member is provided in order to prevent the occurrence of a product defect due to a seal position shift or the like. Since the position of each movable unit is corrected by being moved independently, there is a problem that a drive unit and a position detection unit are required for each movable unit, and the entire apparatus becomes expensive. Moreover, in such a conventional bag making machine, it is necessary to consider the routing of the wiring from each position detection unit, and there is a problem that the wiring work becomes complicated.

  The present invention has been made in consideration of such points, and there is no need to install a driving unit and a position detection unit for each processing unit such as a heat seal unit and a cooling unit, and thus a simple configuration. An object of the present invention is to provide a bag making machine and a bag making method that can prevent the occurrence of product defects such as seal position deviation.

  The bag-making machine of the present invention performs processing on the transport unit that transports the strip-shaped film along the longitudinal direction of the film and the strip-shaped film transported by the transport unit, respectively, along the longitudinal direction of the film. Multiple detection units provided in series, and upstream of each processing unit in the film conveyance direction, and detection marks attached to the belt-shaped film conveyed by the conveyance unit for each product pitch are detected. And a path for adjusting the film path length between the processing units based on the detection information of the detected marks by the mark detection unit so that the film path length between the processing units becomes a desired size. And a length adjusting mechanism.

  According to such a bag making machine, in order to prevent the occurrence of a product defect due to a seal position shift or the like, the detection mark attached to the film for each product pitch is detected, and the film between the processing units is based on this detection information. By adjusting the path length of the film between the processing units so that the path length becomes a desired size, it is necessary to install a driving unit and a position detection unit for each processing unit such as a heat seal unit and a cooling unit, respectively. For this reason, it is possible to prevent the occurrence of product defects such as a deviation of the seal position with a simple configuration.

  In the bag making machine according to the present invention, the path length adjusting mechanism is provided between the plurality of processing units, and each of the plurality of dancer rolls for stretching the film and the plurality of dancer rolls are integrally moved. And a dancer roll drive unit.

  In this case, the dancer roll drive unit may include an elevating unit provided with a dancer roll support portion for supporting each dancer roll, and a drive unit for elevating the elevating unit.

  At this time, the drive unit may include a linear motion linear actuator or a servo motor.

  In the bag making machine of the present invention, the transport unit is provided on the downstream side of each processing unit in the film transport direction, and a first transport part provided on the upstream side of each processing unit in the film transport direction. And the path length adjusting mechanism is configured to detect the film transport speed by the first transport portion and the second transport speed based on the detection information of the detection mark by the mark detection unit. Even if the tension of the film between the processing units is changed by adjusting the difference between the conveyance speed of the film by the conveying part and the path length of the film between the processing units is thereby changed. Good.

  In this case, the path length adjusting mechanism is provided between each of the plurality of processing units, each of which is provided with a plurality of dancer rolls that stretch the film and a dancer roll support unit that supports each dancer roll. You may have a guide member which guides a unit along a perpendicular direction.

  Further, each of the first transport portion and the second transport portion may include a pair of nip rolls, and the film may be transported by sandwiching the film between the pair of nip rolls. .

  In the bag making machine of the present invention, each of the plurality of processing units includes a heat sealing unit that heat-seals the band-shaped film and a cooling that cools the band-shaped film heat-sealed by the heat sealing unit. It may consist of any one of the parts.

  In the bag-making method of the present invention, a belt-shaped film is transported by a step of transporting a strip-shaped film along the longitudinal direction of the film and a plurality of processing units provided in series along the longitudinal direction of the film. A process of performing each processing, and a step of detecting detection marks attached to the belt-shaped film to be transported for each product pitch at a location upstream of each processing unit in the film transport direction, The film path length between the processing units is adjusted based on the detection information of the detection mark so that the film path length between the processing units becomes a desired size.

  According to such a bag making method, in order to prevent the occurrence of a product defect due to a seal position shift or the like, the detection mark attached to the film for each product pitch is detected, and the film between the processing units is based on this detection information. By adjusting the path length of the film between the processing units so that the path length becomes a desired size, it is necessary to install a driving unit and a position detection unit for each processing unit such as a heat seal unit and a cooling unit, respectively. For this reason, it is possible to prevent the occurrence of product defects such as a deviation of the seal position with a simple configuration.

  In the bag-making method of the present invention, a plurality of dancer rolls each of which stretches a film is provided between the plurality of processing units, and when adjusting the path length of the film between the processing units, A plurality of dancer rolls may be moved together.

  Alternatively, when adjusting the path length of the film between the processing units, the film transport speed by the first transport part provided on the upstream side of each processing unit in the film transport direction, and the film transport direction The tension of the film between the processing units is changed by adjusting the difference with the film transport speed by the second transport part provided on the downstream side of the processing units. The path length of the film may be changed.

  According to the bag making machine and the bag making method of the present invention, there is no need to install a driving unit and a position detection unit for each processing unit such as a heat seal unit and a cooling unit, and therefore, the seal position is shifted by a simple configuration. It is possible to prevent the occurrence of product defects due to the above.

It is a block diagram which shows the whole structure of the bag making machine by embodiment of this invention. It is a perspective view which shows the structure of the path length adjustment mechanism which adjusts the path length of the film between process parts, such as a heat seal unit and a cooling unit, in the horizontal seal part of the bag making machine shown in FIG. It is a side view which shows the structure of each process part and path length adjustment mechanism shown in FIG. It is a top view when the path length adjustment mechanism shown in FIG. It is a side view which shows the structure of the linear motion linear actuator in the path length adjustment mechanism shown in FIG. It is a side view which shows the other structure of the path length adjustment mechanism which adjusts the path length of the film between process parts, such as a heat seal unit and a cooling unit, in the horizontal seal part of the bag making machine shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 are views showing a bag making machine according to the present embodiment. Among these, FIG. 1 is a block diagram showing the overall configuration of the bag making machine according to the present embodiment, and FIG. 2 shows a heat seal unit, a cooling unit, etc. in the lateral seal portion of the bag making machine shown in FIG. It is a perspective view which shows the structure of the path length adjustment mechanism which adjusts the path length of the film between process parts. 3 is a side view showing the configuration of each processing unit and path length adjustment mechanism shown in FIG. 2, and FIG. 4 is a top view of the path length adjustment mechanism shown in FIG. FIG. 5 is a side view showing the configuration of the linear motion linear actuator in the path length adjusting mechanism shown in FIG. FIG. 6 is a side view showing another configuration of a path length adjusting mechanism that adjusts a path length of a film between processing units such as a heat seal unit and a cooling unit in the horizontal seal unit of the bag making machine shown in FIG. It is.

  First, the overall configuration of the bag making machine according to the present embodiment will be described with reference to FIG. As shown in FIG. 1, in the bag making machine according to the present embodiment, a belt-like film W is fed out from a paper feed roll 10. A printed pattern is repeatedly printed on the strip-shaped film W with a constant printing pitch (hereinafter also referred to as a product pitch), and a detection mark is provided for each product pitch in the vicinity of the side edge of the film W. Yes. Further, the transport direction of the film W fed out from the paper feed roll 10 is changed by an angle of 90 ° by the turn bar 12 (specifically, on the upstream side of the turn bar 12 in the transport direction of the film W). The film W extends in a direction perpendicular to the paper surface of FIG. 1, but the direction of the film W is changed by the turn bar 12 so that it extends along the paper surface of FIG. Thereafter, the film W is cut into two at the center position in the width direction by the center blade 14, and the two cut films W are turned again at an angle of 90 ° by the M-shaped plate 16, and the inner surfaces face each other. The two films W extend in the direction along the plane of FIG. 1 on the upstream side of the M-shaped plate 16 in the transport direction of the film W. The transport direction of each film W is changed to extend in a direction perpendicular to the paper surface of FIG. 1). At this time, the thermoplastic resin layers in each of the two strip-shaped films W face each other.

  Thereafter, the two belt-like films W are superposed, and the two-layer superposed belt-like films W are intermittently conveyed by the front nip roll 20, the intermediate nip roll 22, and the rear nip roll 24. Here, the front nip roll 20, the intermediate nip roll 22 and the rear nip roll 24 are each composed of a pair, and the film W is conveyed by being sandwiched between the pair of nip rolls. In the present embodiment, the front nip roll 20, the intermediate nip roll 22, and the rear nip roll 24 constitute a transport unit that transports the belt-like film W along the longitudinal direction of the film W. Specifically, the film W is continuously conveyed by a certain amount of movement (specifically, a movement amount having the same size as the product pitch) by the front nip roll 20, the intermediate nip roll 22, and the rear nip roll 24, and then is constant. The operation of stopping the conveyance only for the period is repeated. In addition, the dancer roll 26 provided on the upstream side of the preceding nip roll 20 in the film transport direction aligns the film W in the transport direction between the two layers of the belt-shaped film W.

  As shown in FIG. 1, a vertical seal portion 30 is provided between the front nip roll 20 and the intermediate nip roll 22 in the film W conveyance direction. The vertical seal portion 30 is configured to perform sealing at both side edge portions on the two-layered strip-shaped film W in an overlapped state. Specifically, the vertical seal portion 30 includes a heat seal unit 32 that performs heat seal at both side edges of the two-layered strip-shaped film W in an overlapped state, and heat seal in the transport direction of the film W. A cooling unit 34 is provided on the downstream side of the unit 32 and cools both side edges of the film W heat-sealed by the heat-seal unit 32.

  Further, as shown in FIG. 1, a lateral seal portion 40 is provided between the intermediate nip roll 22 and the rear nip roll 24 in the film W conveyance direction. The horizontal seal portion 40 is configured to seal the two-layered strip-shaped film W in an overlapped state along the width direction. Specifically, the horizontal seal portion 40 includes a plurality of heat seal units 42 that perform sealing along the width direction of the two-layered strip-shaped film W in an overlapped state, and each heat seal unit 42. And a plurality of cooling units 44 that cool the film W that has been sealed in the width direction. In the present embodiment, the plurality of heat seal units 42 and the plurality of cooling units 44 are used to convey the belt-like film W conveyed by the conveyance unit (specifically, the front nip roll 20, the intermediate nip roll 22, and the rear nip roll 24). A plurality of processing units are configured to perform processing on each. Details of the configurations of the heat seal unit 42 and the cooling unit 44 will be described later.

  Further, a cutter unit 46 is provided on the downstream side of the rear-stage nip roll 24 in the transport direction of the film W, and the two-layer belt-like film W sealed by the vertical seal portion 30 and the horizontal seal portion 40 is a cutter. The unit 46 is cut into two at the center position in the width direction and cut along the width direction. In this way, a bag body (specifically, a plastic bag) W ′ as a product is manufactured.

  Next, details of the configuration of the lateral seal portion 40 in the bag making machine of the present embodiment will be described with reference to FIGS. Here, as described above, FIG. 2 shows a path length for adjusting the path length of the film W between the processing parts such as the heat seal unit 42 and the cooling unit 44 in the lateral seal part 40 of the bag making machine shown in FIG. 3 is a perspective view showing a configuration of an adjustment mechanism 50. FIG. 3 is a side view showing the configuration of each processing unit and the path length adjustment mechanism 50 shown in FIG. 2, and FIG. 4 is a top view of the path length adjustment mechanism 50 shown in FIG. These are side views which show the structure of the linear motion linear actuator 60 in the path length adjustment mechanism 50 shown in FIG. In addition, the path length of the film W between process parts is the location (for example, location shown with the reference symbol A) where the process with respect to the film W is performed by a certain process unit (for example, the heat seal unit 42 on the leftmost side in FIG. ) To a place where the processing for the film W is performed (for example, a place indicated by reference numeral B) by another processing part (for example, the cooling unit 44 on the rightmost side in FIG. 3) arranged next to this processing part. The length of the film W.

  As shown in FIG. 2, each heat seal unit 42 includes an elongate heat seal hot plate (heat seal bar) 42 a extending in the width direction of the film W and a heat seal hot plate 42 a sandwiching two layers of the film W. It has the receiving member 42b provided so as to oppose. The heat seal hot plate 42a is made of, for example, a metal such as iron or aluminum, and has a convex cross section. The heat seal hot plate 42a is covered with a sheet of fluorine resin or the like. Then, high-temperature heat is transmitted from a heat source (not shown) to the heat seal hot plate 42a. On the other hand, the receiving member 42b is formed by covering a surface of a rubber member (a surface facing the heat seal hot plate 42a) with a sheet of fluorine resin or the like. Here, the heat seal hot plate 42a is supported by a frame member (not shown) so as to be movable in the vertical direction in FIG. 2, while the receiving member 42b is fixedly attached to the frame member. In each heat seal unit 42, the heat seal hot plate 42a moves toward the receiving member 42b, and the heat seal hot plate 42a comes into contact with the receiving member 42b with the two-layer belt-like film W interposed therebetween. The sealing is performed along the width direction of the film W between the two-layered film W sandwiched between the heat seal hot plate 42a and the receiving member 42b. In FIG. 2 and the like, three heat seal units 42 are shown, but in the rightmost heat seal unit 42 and the third heat seal unit 42 from the right in FIG. 2 and the like, the heat seal hot plate 42a is a receiving member. In the heat seal unit 42 that is second from the right in FIG. 2 and the like, the heat seal hot plate 42a is positioned above the receiving member 42b.

  Further, as shown in FIG. 2, each cooling unit 44 has an elongated cooling plate (cooling bar) 44a and a receiving member 44b provided so as to face the cooling plate 44a with a two-layer belt-like film W interposed therebetween. doing. The cooling plate 44a is made of a metal such as iron or aluminum and is cooled by a cooling source (not shown). The cooling plate 44a is covered with a sheet of fluorine resin or the like. On the other hand, the receiving member 44b is formed by covering a surface of a rubber member (a surface facing the cooling plate 44a) with a sheet of fluorine resin or the like. Here, the cooling plate 44a is supported by a frame member (not shown) so as to be movable in the vertical direction in FIG. 2, while the receiving member 44b is fixedly attached to the frame member. In each cooling unit 44, the cooling plate 44a moves toward the receiving member 44b, and the cooling plate 44a comes into contact with the receiving member 44b with the two layers of the strip-shaped film W interposed therebetween. The two-layered strip-shaped film W sandwiched between the receiving member 44b is cooled along the width direction. In FIG. 2 and the like, two cooling units 44 are shown. In the cooling unit 44 on the right side in FIG. 2 and the like, the cooling plate 44a is positioned above the receiving member 44b, whereas FIG. In the cooling unit 44 on the left side in the above, the cooling plate 44a is positioned below the receiving member 44b.

  Further, as shown in FIG. 2 and the like, a plurality of guide rolls 49 are provided at a fixed position so as to be arranged in series along a horizontal plane in the horizontal seal portion 40, and the film W is stretched by these guide rolls 49. Thus, the film W is guided.

  In the horizontal seal portion 40, a detection sensor 48 such as a CCD camera is installed on the upstream side of each heat seal unit 42 or each cooling unit 44 in the transport direction of the film W. As described above, the printed pattern is repeatedly printed at a constant product pitch on the belt-like film W fed out from the paper feed roll 10, and a detection mark is provided for each product pitch in the vicinity of the side edge of the film W. Although attached, this detection mark is detected by the detection sensor 48. In the bag making machine according to the present embodiment, based on the detection information of the detection mark detected by the detection sensor 48, a path length adjusting mechanism 50 described later is used between processing units such as the heat seal unit 42 and the cooling unit 44. The path length of the film W between the processing units is adjusted so that the path length of the film W becomes a desired size (specifically, an integral multiple of the product pitch), and the film W between the heat seal units 42 is adjusted. The path length, the path length of the film W between the cooling units 44, and the path length of the film W between the heat seal unit 42 and the cooling unit 44 are each determined by the size of the interval based on the product pitch (that is, the product pitch). It is designed to match the size of an integer multiple of.

  Details of the configuration of the path length adjusting mechanism 50 will be described below. As shown in FIG. 2 and the like, the path length adjusting mechanism 50 has a plurality of dancer rolls 52 provided between processing units such as the heat seal unit 42 and the cooling unit 44, respectively. Each dancer roll 52 is provided between a pair of guide rolls 49 in the conveyance direction of the film W, and the film W is stretched between the guide rolls 49. The path length adjustment mechanism 50 is configured to change the path length of the film W between the processing units by lifting and lowering the plurality of dancer rolls 52 integrally. Here, as shown in FIGS. 2 to 4, each dancer roll 52 is rotatably supported at both ends by dancer roll support portions 54, and the plurality of dancer roll support portions 54 are supported by the lifting member 56. It is attached. More specifically, as shown in FIG. 4, two elevating members 56 are provided so as to extend in parallel along the horizontal plane with a space therebetween, and a plurality of dancer roll support portions 54 are attached to each elevating member 56. It has been. And each dancer roll 52 rotates between the dancer roll support part 54 attached to the upper raising / lowering member 56 in FIG. 4 and the dancer roll support part 54 attached to the lower raising / lowering member 56 in FIG. It is supported freely.

  As shown in FIG. 4, two elevating members 56 provided so as to extend in parallel along a horizontal plane with a space therebetween are connected by a connecting member 58, and a linear motion linear actuator is connected to the connecting member 58. 60 is disposed. Then, when the connecting member 58 is driven by the linear motion linear actuator 60 to move in the vertical direction (a direction orthogonal to the paper surface of FIG. 4), each lifting member 56 is integrally formed in the direction of the arrow in FIGS. And the dancer rolls 52 are also raised and lowered. Here, in FIG. 2 and FIG. 3, the positions of the dancer rolls 52 and the elevating members 56 when the print pitch (that is, the product pitch) of the printed pattern repeatedly printed on the belt-like film W is relatively small are indicated by solid lines. In addition, the positions of the dancer rolls 52 and the elevating members 56 when the print pitch (that is, product pitch) of the printed pattern repeatedly printed on the belt-like film W is relatively large are indicated by two-dot chain lines. As described above, the path length is adjusted based on the detection information of the detection mark detected by the detection sensor 48 in accordance with the size of the print pattern (that is, the product pitch) of the printed pattern repeatedly printed on the belt-like film W. The film between the processing units is set such that the path length of the film W between the processing units such as the heat seal unit 42 and the cooling unit 44 is set to a desired size (specifically, an integral multiple of the product pitch). The path length of W can be changed. In particular, in the bag making machine as shown in FIG. 1, the pitch deviation of the adjacent patterns in the belt-like film W is generally zero, so that the dancer roll 52 is integrally moved up and down by the path length adjusting mechanism 50, and the heat seal unit By making the path length of the film W between the processing units such as 42 and the cooling unit 44 uniform, it is possible to prevent occurrence of a seal position shift and a cooling position shift in the film W.

  Next, details of the configuration of the linear motion linear actuator 60 will be described with reference to FIG. As shown in FIG. 5, the linear motion linear actuator 60 has a ball screw 62 extending in the vertical direction, a motor 64 that rotationally drives the ball screw 62, and a nut 66 fitted to the ball screw 62. The nut 66 is attached to the connecting member 58 via the attachment member 68. When the motor 64 rotates the ball screw 62, the nut 66 moves in the vertical direction in FIG. 5, and the connecting member 58 attached to the nut 66 also moves in the vertical direction in FIG. In this way, the elevating members 56 are integrally moved up and down along the direction of the arrows in FIGS. 2 and 3 by driving the motor 64, and the dancer rolls 52 are also raised and lowered.

  In the present embodiment, an elevating unit is configured by two elevating members 56 provided with dancer roll support portions 54 that support each dancer roll 52 and a connecting member 58 that connects these two elevating members 56. Yes. In addition, a dancer roll driving unit that integrally moves the plurality of dancer rolls 52 by uniaxial driving is configured by the lifting unit and the linear motion linear actuator 60 that lifts and lowers the lifting unit.

  According to the bag making machine and the bag making method of the present embodiment configured as described above, on the upstream side of each processing unit such as the heat seal unit 42 and the cooling unit 44 in the conveyance direction of the film W, the conveyance unit A detection sensor 48 is provided as a mark detection unit for detecting detection marks attached to the product film pitch on the belt-like film W conveyed by the processing unit. Based on detection information of the detection mark by the detection sensor 48, a processing unit is provided. The path length of the film W between the processing units is adjusted by the path length adjusting mechanism 50 so that the path length of the film W between the processing units becomes a desired size. According to the configuration of such a bag making machine, in order to prevent the occurrence of a product defect due to a seal position shift or the like, the detection mark attached to the film W for each product pitch is detected, and the processing unit is based on this detection information. By adjusting the path length of the film W between the processing units by, for example, uniaxial driving so that the path length of the film W between them becomes a desired size, the driving unit and position detection for each heat seal unit 42 and cooling unit 44 Therefore, it is not necessary to install the respective parts, and therefore, it is possible to prevent the occurrence of product defects such as deviation of the seal position with a simple configuration.

  Further, in the bag making machine according to the present embodiment, even when the printing item is changed, and the size of the print pattern (that is, the product pitch) of the printed pattern that is repeatedly printed on the belt-like film W is changed. It is not necessary to move the heat seal unit 42 or the cooling unit 44 along the transport direction of the film W. Here, in the prior art, the path length of the film W between the processing units is an integral multiple of the product pitch by manually or automatically moving the heat seal unit 42 and the cooling unit 44 along the transport direction of the film W. However, when the heat seal unit 42 and the cooling unit 44 are manually aligned, for example, the heat seal unit 42 and the cooling unit 44 can be moved in units of 1 mm, for example. For this reason, the path length of the film W between the processing units cannot be adjusted with high accuracy. On the other hand, when the path length of the film W between the processing units is automatically adjusted by the above-described path length adjusting mechanism 50, the path length of the film W between the processing units is adjusted in units of several tens of micrometers. Therefore, the path length of the film W between the processing units can be accurately adjusted to an integral multiple of the product pitch, and the work burden on the operator can be reduced.

  In the bag making machine according to the present embodiment, as described above, the path length adjusting mechanism 50 is provided between a plurality of processing units such as the heat seal unit 42 and the cooling unit 44, and A plurality of dancer rolls 52 that are stretched and a dancer roll drive unit that moves the plurality of dancer rolls 52 integrally. Here, the dancer roll drive unit is an elevating unit (specifically, two elevating members 56 and a connecting member 58 that connects these elevating members 56) provided with dancer roll support portions 54 that support each dancer roll 52. ) And a drive unit for moving the lifting unit up and down. As described above, the linear motion linear actuator 60 is used as the drive unit.

  In addition, the bag making machine and the bag making method according to the present embodiment are not limited to the above-described aspects, and various modifications can be made.

  For example, in the path length adjusting mechanism of the present embodiment, the drive unit that moves up and down the lifting unit composed of the two lifting members 56 and the connecting member 58 that connects these lifting members 56 is a linear motion linear as shown in FIG. The actuator 60 is not limited. Various mechanisms other than the linear motion linear actuator 60, such as a servo motor, can be used as the drive unit for moving the lifting unit up and down.

  Further, as a path length adjusting mechanism for adjusting the path length of the film W between the processing units such as the heat seal unit 42 and the cooling unit 44, as shown in FIG. 6 instead of the configuration shown in FIGS. You may use the thing of a simple structure.

  As shown in FIG. 6, an intermediate nip roll 22 including a pair of nip rolls is provided as a first transport portion on the upstream side of each processing unit such as the heat seal unit 42 and the cooling unit 44 in the transport direction of the film W. In addition, a downstream nip roll 24 including a pair of nip rolls is provided as a second transport portion on the downstream side of each processing unit in the transport direction of the film W. Then, the path length adjusting mechanism 50a according to the modification as shown in FIG. 6 is based on the detection information of the detection mark by the detection sensor 48, and the conveyance speed of the film W by the intermediate nip roll 22 that is the first conveyance portion, The tension of the film W between the processing units is changed by adjusting the difference from the conveyance speed of the film W by the second-stage nip roll 24 which is the second conveyance part, and thereby the path length of the film W between the processing units is changed. It is supposed to change.

  The path length adjusting mechanism 50a according to the modified example shown in FIG. 6 will be described in more detail. The path length adjusting mechanism 50a is provided between the processing units such as the heat seal unit 42 and the cooling unit 44, and each is a film. A plurality of dancer rolls 52 that stretch W are provided. Each dancer roll 52 is rotatably supported at both ends by a dancer roll support portion 54, and the plurality of dancer roll support portions 54 are attached to an elevating member 56. More specifically, two elevating members 56 are provided so as to extend in parallel along the horizontal plane with a space therebetween (only one elevating member 56 is shown in FIG. 6), and each elevating member 56 has a plurality of elevating members 56. A dancer roll support 54 is attached. Moreover, the two raising / lowering members 56 provided so that it may extend in parallel at intervals may be connected by the connection member (not shown). Here, also in the path length adjustment mechanism 50a according to the modification, two elevating members 56 provided with dancer roll support portions 54 that support the dancer rolls 52, and a connecting member that connects these two elevating members 56, Thus, the lifting unit is configured.

  As shown in FIG. 6, the path length adjusting mechanism 50 a according to the modification includes a pair of guide members 70 that vertically guide a lifting unit provided with a dancer roll support portion 54 that supports each dancer roll 52. Have. The pair of guide members 70 are provided so as to extend along the vertical direction, and the elevating member 56 is guided by these guide members 70 so as to move along the vertical direction. Further, a pair of left and right bar-shaped balancing members 72 are provided at both ends of the elevating member 56. A support shaft 72 b is provided at a substantially central position of each balancing member 72. In addition, pins 56 a are provided at both ends of the elevating member 56, and an elongated hole into which the pin 56 a is fitted into one end of each balancing member 72 (an end closer to the elevating member 56). 72a is formed, and the pin 56a provided on the elevating member 56 is movable in the elongated hole 72a. Further, a weight 74 is suspended from the other end 72c (the end far from the elevating member 56) of each balancing member 72. Since each of the balancing members 72 applies an upward force to the elevating member 56 via the pin 56a, the elevating unit is prevented from dropping due to its own weight.

  Further, as shown in FIG. 6, rotary encoders 23 and 25 are provided on the intermediate nip roll 22 as the first conveyance portion and the rear nip roll 24 as the second conveyance portion, respectively. The rotational speeds of the intermediate nip roll 22 and the rear nip roll 24 are detected by these rotary encoders 23 and 25. Based on the detection results of the rotary encoders 23 and 25, the film by the intermediate nip roll 22 and the rear nip roll 24 is detected. The transport speed of W is calculated respectively.

  In the path length adjusting mechanism 50a according to such a modified example, based on the detection information of the detection mark by the detection sensor 48, the transport speed of the film W by the intermediate nip roll 22 that is the first transport portion, and the second transport portion. The tension of the film W between the processing units is changed by adjusting the difference between the transport speed of the film W by the latter-stage nip roll 24 and thereby the path length of the film W between the processing units is adjusted. ing. More specifically, when it is desired to increase the path length of the film W between the processing units such as the heat seal unit 42 and the cooling unit 44, the intermediate nip roll 22 ( The conveyance speed of the film W by a 1st conveyance part) is made larger than the conveyance speed of the film W by the back | latter stage nip roll 24 (2nd conveyance part). As a result, the tension of the film W between the processing units decreases, and the elevating unit moves downward due to its own weight, so that each dancer roll 52 also descends and the path length of the film W between the processing units increases. On the other hand, when it is desired to reduce the path length of the film W between the processing units such as the heat seal unit 42 and the cooling unit 44, the intermediate nip roll 22 (the first nip roll 22) is used when the film W is moved in the intermittent feeding of the film W. The conveyance speed of the film W by (conveyance part) is made smaller than the conveyance speed of the film W by the back | latter stage nip roll 24 (2nd conveyance part). As a result, the tension of the film W between the processing units increases, and the lifting unit is moved upward by each balance member 72, so that each dancer roll 52 also rises, and the path length of the film W between the plurality of processing units Becomes smaller.

  As described above, even the path length adjusting mechanism 50a according to the modification shown in FIG. 6 is detected according to the size of the print pattern (that is, the product pitch) of the printed pattern that is repeatedly printed on the belt-like film W. Based on the detection information of the detection mark detected by the sensor 48, the path length adjustment mechanism 50a allows the path length of the film W between the processing units such as the heat seal unit 42 and the cooling unit 44 to have a desired size (specifically, It becomes possible to adjust the path length of the film W between the processing units so as to be an integral multiple of the product pitch. In particular, as described above, in the bag making machine as shown in FIG. 1, the pitch deviation of the adjacent pattern in the belt-like film W is generally zero, so the path length adjusting mechanism 50a causes the film W between the processing units to be moved. By adjusting the tension and making the size of the path length of the film W between the processing portions uniform, it is possible to prevent the occurrence of a seal position shift or a cooling position shift in the film W.

  In a further modification according to the present invention, the path length adjustment mechanism is configured such that the path length of the film W between the processing units is a desired size (specifically, the product) As long as the path length of the film W between the processing units can be adjusted so as to be an integral multiple of the pitch), the configuration other than the configuration shown in FIGS. 2 to 5 or the configuration shown in FIG. The thing of the structure of may be used.

DESCRIPTION OF SYMBOLS 10 Paper feed roll 12 Turn bar 14 Center blade 16 M-shaped board 20 Front nip roll 22 Intermediate nip roll 23 Rotary encoder 24 Rear nip roll 25 Rotary encoder 26 Dancer roll 30 Vertical seal part 32 Heat seal unit 34 Cooling unit 40 Horizontal seal part 42 Heat seal unit 42a Heat seal hot plate 42b Receiving member 44 Cooling unit 44a Cooling plate 44b Receiving member 46 Cutter unit 48 Detection sensor 49 Guide roll 50, 50a Path length adjusting mechanism 52 Dancer roll 54 Dancer roll support 56 Lifting member 56a Pin 58 Connecting member 60 Linear actuator 62 Ball screw 64 Motor 66 Nut 68 Mounting member 70 Guide member 72 Balance member 72a Long hole 72b Support shaft 72c End 74 Weight W Lum W'bag

Claims (11)

A transport unit for transporting the belt-shaped film along the longitudinal direction of the film; and
A plurality of processing units provided in series along the longitudinal direction of the film, each performing processing on the belt-shaped film transported by the transport unit;
A mark detection unit that is provided on the upstream side of each processing unit in the conveyance direction of the film, and detects a detection mark that is attached to the belt-like film conveyed by the conveyance unit for each product pitch;
A path length adjustment mechanism for adjusting the film path length between the processing units based on detection information of the detection marks by the mark detection unit so that the film path length between the processing units has a desired size;
A bag making machine.   The path length adjusting mechanism includes a plurality of dancer rolls provided between the plurality of processing units, each of which stretches a film, and a dancer roll driving unit that integrally moves the plurality of dancer rolls. The bag making machine according to claim 1.   The bag making machine according to claim 2, wherein the dancer roll drive unit includes an elevating unit provided with a dancer roll support part for supporting each dancer roll, and a drive part for elevating the elevating unit.   The bag making machine according to claim 3, wherein the drive unit includes a linear motion linear actuator or a servo motor. The transport unit includes a first transport part provided on the upstream side of the processing units in the film transport direction, and a second transport part provided on the downstream side of the processing units in the film transport direction. Including,
The path length adjustment mechanism adjusts a difference between a film conveyance speed by the first conveyance part and a film conveyance speed by the second conveyance part based on detection information of the detection mark by the mark detection unit. 2. The bag making machine according to claim 1, wherein the tension of the film between the processing units is changed thereby changing the path length of the film between the processing units.   The path length adjusting mechanism is vertically provided between the plurality of processing units, and vertically includes a plurality of dancer rolls that stretch the film and a dancer roll support unit that supports the dancer rolls. The bag making machine according to claim 5, further comprising a guide member that guides along the direction.   The first transport portion and the second transport portion each include a pair of nip rolls, and the film is transported by being sandwiched between the pair of nip rolls. Or the bag making machine of 6.   Each of the plurality of processing units includes any one of a heat sealing unit that heat-seals a band-shaped film and a cooling unit that cools the band-shaped film heat-sealed by the heat sealing unit. The bag making machine according to any one of claims 1 to 7. A step of conveying the belt-like film along the longitudinal direction of the film;
A process of performing processing on each of the belt-shaped films conveyed by a plurality of processing units provided in series along the longitudinal direction of the film,
A step of detecting a detection mark attached to each of the product pitches on the belt-like film to be transported at a location upstream of each processing unit in the film transport direction;
With
A bag making method of adjusting a film path length between the processing units based on detection information of a detection mark so that a film path length between the processing units becomes a desired size. A plurality of dancer rolls each extending a film are provided between the plurality of processing units,
The bag making method according to claim 9, wherein the plurality of dancer rolls are integrally moved when adjusting a path length of the film between the processing units.   When adjusting the path length of the film between the processing units, the film transport speed by the first transport part provided on the upstream side of each processing unit in the film transport direction, and the each in the film transport direction The tension of the film between the processing units is changed by adjusting the difference with the film transport speed by the second transport part provided on the downstream side of the processing unit, and thereby the film between the processing units. The bag making method according to claim 9, wherein the path length is changed.

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