JP6018900B2 - Center seal device for bag making filling and packaging machine - Google Patents

Description

  The present invention relates to a center seal device in a bag-filling and packaging machine that forms a center seal by heating a superposed portion at both side edges of a cylindrical packaging material and crimping the heated superposed portion.

  2. Description of the Related Art Conventionally, a bag making and filling machine, particularly a horizontal bag making and filling machine, horizontally transfers a packaging material bent from a belt shape to a substantially cylindrical shape by a cylinder making machine, and transfers articles supplied by a supply conveyor. A cylindrical packaging material is formed by applying a center seal to a superposed portion of the side edge portion extending in the longitudinal direction of the packaging material by a center seal device. A pillow package is manufactured by applying an end seal to the cylindrical packaging material at positions before and after the longitudinal direction with the end seal device interposed therebetween. The bag packaging body is separated from the cylindrical packaging material by a cutter device provided by being incorporated in the end seal device.

  In the center seal device, a pair of substantially rectangular parallelepiped heater bars (bar heaters) with built-in heaters are arranged so as to sandwich the overlapping portions at both side edges of the packaging material, thereby forming a heater unit for the center seal. Has been. By maintaining the gap between the heater bars at a gap that is lightly in contact with the overlapped portion of the packaging material, the overlapped portion of the packaging material that passes through the gap is softened by being heated by the radiant heat from both heater bars. The softened overlapped portion is pressed by being clamped by a pressing roller arranged at the next stage of the heater portion, and a center seal is applied (see Patent Document 1).

  The pair of heater bars as described above are positioned so as to maintain the gap during operation of the horizontal bag making filling and packaging machine, but when the horizontal bag making filling and packaging machine is stopped, the pair of heater bars are moved in a direction to open the gap. Take a position away from the overlapped portion of the cylindrical packaging material. This is because if the packaging machine is stopped while the overlapping portion of the packaging material is close to the heater bar and the transfer of the packaging material is also stopped at that time, the specific overlapping portion sandwiched between the two heater bars is excessively heated by the heater bar. This is to avoid melting the polymerized portion. Even during the operation of the packaging machine, for example, if an empty bag prevention function that prevents the manufacture of empty bags that do not contain articles in the bag is activated, the transfer of the packaging material is stopped. The heater bar is configured to open and wait.

  As a drive source for opening and closing the heater bar, conventionally, there are one using an electromagnetic solenoid (see Patent Document 2) and one using an air cylinder (air actuator). The amount of gap required when the heater bar is closed is determined in advance by conditions such as the thickness of the packaging material to be used. In this way, the amount of gap when the heater bar is closed varies depending on the conditions. Therefore, when various packaging materials are used in one packaging machine, the clearance is adjusted according to the type of packaging material before use. Was necessary. Mechanical adjustment is required to adjust the gap. Such adjustment is troublesome and time consuming, and is a factor that reduces the operating efficiency of the packaging machine. In view of this, the present applicant has proposed a bar heater device that uses a servo motor as a heater bar opening / closing drive source so that the gap can be easily adjusted. According to this proposal, adjustment of the gap between the heater bars is facilitated, and by using a servo motor, foreign matter contamination detection is also performed without adding a sensor (Japanese Patent Application No. 2011-126809).

  On the other hand, if the packaging material from the roll is almost finished while the packaging machine is in operation, the packaging material from the new roll is spliced using, for example, a paper joining tape, and the packaging machine is stopped. The continuous operation is not performed, and the operation efficiency of the packaging machine is improved. When the splicing part is detected by detecting a splicing tape, the heater bar is opened in accordance with the timing when the splicing part reaches the bar heater, the gap is enlarged, the paper splicing part is passed, and then closed again after passing. The operation is performed (see the above-mentioned patent application: Paragraph 37 of Japanese Patent Application No. 2011-126809). Since the jointed portion of the paper is overlapped with the wrapping material and connected with tape, the portion has a thickness equivalent to three wrapping materials, and the edge of the center seal portion is polymerized. There is the thickness of the sheet. When the heater bar open / close drive source is an electromagnetic solenoid or air cylinder, it is configured to maintain a predetermined gap amount. It becomes caught without being able to enter the gap, and the normal packaging material cannot be transferred. In order to avoid such a situation, the heater bar is opened and closed as described above.

  In particular, when a servo motor is used, the gap amount determined by the position control is maintained, so that the paper splicing part is caught by the heater bar, and the catching force is within the rated range of the servo motor. If there is, the conveyance of the packaging material will be poor, and if more force is applied, an overload alarm will occur and the machine will stop. In order to prevent such a situation, when a paper splicing part is detected during operation of the packaging machine, the heater bar is opened in accordance with the timing at which the paper splicing part reaches the bar heater, and the paper splicing part is allowed to pass through the open gap. The servo motor is driven and controlled to perform the operation of closing the heater bar again after the passage. A packaging bag or bag package made of a packaging material including a paper spliced portion that has been passed through is discharged out of the system as a defective product in the downstream portion.

  As a matter of course, the center seal is not applied to the wrapping material before and after the paper splicing which the heater bar is opened and passed. If the article to be packaged is a normal solid, there is no problem, but if it is a food sprinkled with powder such as candy or fertilizer, or food with a fluid such as jam, the center seal There is a problem that powder or fluid leaks from a portion where no is applied, and the conveying path is soiled.

Japanese Utility Model Publication No. 5-18129 Japanese Utility Model Publication No. 51-43966

  Therefore, in the bag-filling and packaging machine that forms the center seal by heating the overlapping portions at both side edges along the longitudinal direction of the packaging material and crimping the heated overlapping portions, the overlapping portion of the packaging material has a thickness. A center seal device that makes it possible to easily pass a splicing portion appearing as an increased portion without being caught and to seal a superposed portion including the splicing portion with a minimum sealing performance as a center seal is obtained. There is a problem to be solved in terms of points.

  An object of the present invention is to solve the above-mentioned problem, and in a center seal device of a bag making filling and packaging machine, a paper splicing portion that appears as a portion having an increased thickness in a superposed portion of a packaging material pushes a gap between heater bars. It is another object of the present invention to provide a center seal device in a bag making and filling and packaging machine that is easy to pass through.

  In order to solve the above-mentioned problems, the center seal device in the bag making and filling and packaging machine according to the present invention is disposed so as to face the gap, and the overlapping portion of the side edge portion extending in the longitudinal direction of the packaging material has the gap. Two heater bars that heat the overlapped portion when passing, a servo motor as a drive source that normally drives the heater bar to open and close by a position control method, and the rotation output of the servo motor is converted into an opening / closing operation of the heater bar A bar heater portion having a motion conversion mechanism, a pressure roller portion disposed on the downstream side in the feed direction of the packaging material of the heater bar and crimping the heated overlapping portion to perform center sealing, and the opening and closing of the heater bar In order to operate, a control unit for controlling the drive of the servo motor is provided, and the control unit includes a paper splicing portion of the packaging material that is the heater. At the moment that passes through the gap over, and switches the torque control scheme to weaken the position holding force for the control method applied from the position control scheme in the closing direction of the heater bar of the servo motor.

  According to the center seal device in this bag-filling and packaging machine, the gap between the pair of heater bars is normally set to a predetermined gap according to the seal specification of the packaging material by driving a servo motor for opening and closing. The position is controlled. When the overlapping portions at both side edges of the packaging material pass between the heater bars, the overlapping portions are heated by the radiant heat from the heater bars. The heated superposed portion is subjected to pressure bonding at a pressure roller portion provided at the next stage of the bar heater portion, so that a center seal is applied. A continuous wrapping operation can be performed without stopping the bag making filling and wrapping machine by joining the strip wrapping material with the strip wrapping material fed from a new wrapping material roll. The paper spliced portion appears as a portion where the thickness is greatly increased in the overlapped portion of the belt-shaped packaging material. Since the timing at which the splicing portion passes the bar heater after the splicing portion is detected can be predicted, the servo motor control method is the position control method in accordance with the timing at which the splicing portion passes the heater member. To a torque control system with a weak position holding force acting in the closing direction. Accordingly, the position holding force is weak without opening the heater bar by driving by the servo motor position control method, and therefore the paper splicing portion can pass while pushing the heater bar open. Since the heater bar is not far away from the passing overlapping portion, it is possible to heat the overlapping portion including the paper splicing portion to the extent that the minimum sealing performance can be obtained by pressure bonding. After the paper splicing portion passes through the bar heater portion, the servo motor immediately returns the heater bar to the original gap by the torque control method.

In the center seal device in this bag making filling and packaging machine, the center seal of the packaging material is continuously performed through a packaging cycle assigned to each packaging material portion corresponding to one bag, and the servo motor The control method can be switched to the torque control method for each packaging cycle including the paper splicing portion when the paper splicing portion passes through the gap between the two heater bars. By switching to the torque control method of the servo motor for each packaging cycle, the center seal is normally performed continuously throughout the packaging cycle by the position control method, but at the timing when the paper splice part passes through the gap of the heater bar. The servo motor control method is switched to the torque control method in correspondence with a specific packaging cycle including the spliced portion. Therefore, when all paper splicing parts are included in one packaging cycle, the bag packaging body having the minimum sealing performance is the one bag packaging body, and the paper splicing section spans two packaging cycles. In such a case, the bag package having the minimum sealing performance becomes the two bag packages, and the number of bag packages that are handled as defective products can be minimized.

  In the center seal device in this bag making filling and packaging machine, from the packaging cycle after the paper spliced portion has passed between the two heater bars, the control method of the servo motor is changed from the torque control method to the position control method. You can return to By returning the servo motor control system to the position control system from the packaging cycle after passing through the paper spliced portion, normal center sealing is continuously performed throughout the packaging cycle, and a normal bag package is manufactured.

  In the center seal device in this bag making filling and packaging machine, the packaging assigned to the packaging material extending from an installation position of a paper joint part detection sensor for detecting the paper joint part of the packaging material to an installation position of the heater bar. A set shift number is set as the number of cycles, and the control unit starts counting the number of shifts in accordance with the first packaging cycle after detecting the paper splicing portion, and each subsequent transition of the packaging cycle. The control method can be switched in response to the number of shifts counted and added reaching the set shift number. By this control unit, the control of the bar heater unit according to the feeding of the packaging material from the time when the paper joining part detection sensor detects the paper joining part of the packaging material to the switching of the servo motor control method, the length of one bag is controlled. Control is performed with the number of shifts counted for each packaging cycle through the packaging cycle according to each, and the control method of the servo motor is switched when the shift number reaches the set shift number, so the control is simplified. The

  In the center seal device in this bag making filling and packaging machine, in the torque control method, as the output torque of the servo motor, when the paper splicing portion passes through the gap between the heater bars, the paper splicing portion causes the heater bar to move. A small set torque can be set so that the heater bar quickly returns to the original position after passing through the paper splicing portion. By setting the output torque of the servo motor to such a small setting torque, when the paper splicing part passes through the gap between the heater bars, the paper splicing part passes through the heater bar, and the paper splicing part passes through the heater bar. After the paper splicing portion moves between the heater bars, the heater bar quickly returns to the original position, and the superposed portion including the paper splicing portion can be heated to the minimum.

In the center seal device in this bag making filling and packaging machine, a setting / display unit is provided for an operator to set the control unit. In the setting / display unit, the normal gap amount between the heater bars is provided. Value, the value of the set shift number as a packaging cycle assigned to the packaging material extending from the placement position of the paper splicing portion detection sensor to the placement position of the heater bar , and the splicing portion pushes the heater bar open. It is possible to set a value of the set torque that allows the passage and allows the heater bar to quickly return to the original position after passing through the spliced portion . Depending on the value of the normal gap between the heater bars set by the operator in the setting / display section, the gap between the heater bars of the bar heater section in the normal packaging operation is controlled by the servo motor position control method. Controlled by quantity. In addition, the packaging cycle corresponding to the set shift number that matches the timing when the paper splicing part passes the bar heater part is determined by the value of the set shift number and the set torque value set by the operator in the setting / display unit, Further, torque control is performed so that the torque of the servo motor becomes the set torque in the packaging cycle.

  In the center seal device in this bag making filling and packaging machine, the motion conversion mechanism is provided at both ends of the rotating bar attached to the output shaft of the servomotor and the output bar center of the rotating bar. The fitting pin, two guide shafts provided in parallel to the direction of sandwiching the overlapped portion of the packaging material, and the fitting pin that is guided by the two guide shafts and is movable toward and away from each other. It is possible to provide an attachment block in which a long hole is formed to fit, and the heater bar containing the heater is attached to the attachment block via a heat insulating material. When the servomotor is driven by this motion conversion mechanism and the output shaft rotates, the rotation bar rotates, and the fitting pins provided at both ends of the rotation bar perform an arc motion. The mounting block in which the fitting pin is fitted into the long hole is guided by the two guide shafts by the circular motion of the fitting pin and moves toward and away from each other. Because of this motion conversion mechanism, the position of the heater bar attached to the mounting block uniquely corresponds to the amount of rotation of the servomotor output shaft. The position of the heater bar can be accurately controlled by controlling the amount.

In the center seal device in this bag making filling and packaging machine, the heater bar has a large opening on the inlet side where the packaging material relatively enters, and the opening gradually narrows as the entering packaging material advances. A taper can be provided. By providing a taper with a large opening on the inlet side of the packaging material of the heater bar, the paper splice portion with increased thickness is guided by the taper and smoothly enters the gap without being caught on the inlet side of the heater bar. After the taper is narrowed and the paper splicing portion comes into contact with the heater bar, the paper splicing portion can enter by pushing the heater bar open.

In the center seal device in this bag making filling and packaging machine, the bag making filling and packaging machine is configured such that the center is overlapped with overlapping portions on both side edges of a belt-like packaging material bent in a substantially cylindrical shape as the packaging material. A cylindrical packaging material is formed by applying the center seal by a sealing device, the product to be packaged is filled in the cylindrical packaging material, and end sealing is applied to the cylindrical packaging material before and after the product. Thus, it can be a horizontal bag making and filling machine or a vertical bag making and filling machine that performs pillow packaging. Further, in the bag making and filling machine, the servo motor is controlled from the position control method according to the control mode that is always the position control method and the timing at which the paper splicing portion passes through the gap of the heater bar. It can be assumed that it is possible to switch between the control modes changed to the control method. By making the control mode switchable in this way, the servo motor control system is always set to the position control system according to the properties of the articles to be packaged and the type and nature of the packaging material, Whether to use the position control method or the torque control method can be selected in accordance with the timing of passing through the gap between the heater bars.

  Since the center seal device in the bag-filling and packaging machine according to the present invention is configured as described above, the position of the servo motor control system for opening and closing the heater bar when the paper splicing portion passes through the bar heater portion is controlled. Since the torque control method is switched to the torque control method, and the torque control method is driven with a torque that weakens the position holding force of the heater bar, the increased thickness of the spliced portion is allowed to pass through the gap between the heater bars. Further, since the heater bar is not separated from the overlapped portion of the packaging material including the paper spliced portion, the overlapped portion of the packaging material can be heated, and therefore, a center seal with a minimum sealing performance can be applied. As a result, even if food to be packaged is food that is sprinkled with powder such as candy or fertilizer, or food that is accompanied by fluid such as jam, powder or fluid from the polymerized part that has been center-sealed. Can be prevented from leaking, and the conveyance path can be prevented from becoming dirty. As a result, the operation of the packaging machine is not stopped for cleaning the conveying path and the operation efficiency of the packaging machine can be improved.

FIG. 1 is a side view showing an embodiment of a bag making and filling machine according to the present invention. FIG. 2 is a top view of the bag making and filling machine shown in FIG. FIG. 3 is a top view of a center seal device used in the bag making filling and packaging machine shown in FIG. FIG. 4 is a perspective view illustrating an example of a bar heater unit provided in the center seal device illustrated in FIG. 3. FIG. 5 is a four-sided view showing details of the bar heater portion of the center seal device shown in FIG. FIG. 6 is a block diagram illustrating an example of a control unit that controls the center seal device provided in the bag making filling and packaging machine illustrated in FIG. 1. FIG. 7 is a flowchart showing an example of the operation of the control unit shown in FIG. 8 is an operation chart corresponding to the flowchart shown in FIG. 7 of the control unit shown in FIG.

  Hereinafter, an embodiment of a center seal device of a bag making filling and packaging machine according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a side view showing an embodiment of a bag making and filling machine according to the present invention, and FIG. 2 is a plan view of the bag making and filling machine shown in FIG.

  The bag making filling and packaging machine shown in FIGS. 1 and 2 is configured such that a bag is formed from a film-like packaging material (hereinafter referred to as “packaging film”) that is transported in the lateral direction, and an article P is fed into the bag. This is a horizontal bag making and filling machine 1 in which a pillow package Bp which is a bag package is continuously manufactured. The horizontal bag making filling and packaging machine 1 includes a film supply source 2 that rotatably loads and supports a film roll Fr wound with a web-like packaging film Fw on the upstream side of the packaging film, and a web-like packaging film from the film roll Fr. And a paper feed roller 3 for feeding out Fw. The paper feed roller 3 includes a driving roller 3 a and a driven roller 3 b that sandwich and feed the web-like packaging film Fw. The driving roller 3 a of the paper feed roller 3 is appropriately transmitted from the paper feed servomotor 4. Driven through the mechanism. The web-shaped packaging film Fw fed out from the paper feed roller 3 is bent by the cylinder making machine (former) 5 until the side edge portions are drawn toward each other and become substantially cylindrical.

  On the upstream side of the paper feed roller 3, a paper splicing part detection sensor 62 is provided for detecting the passage of the paper splicing part when the packaging film is spliced. The splicing part detection sensor 62 can also serve as a registration mark detection sensor that detects a registration mark that is marked on the packaging film by printing or the like for each unit of the packaging bag and serves as a mark of the packaging material for one bag. Since the tape width of the splicing tape used for the splicing portion is usually wider than the mark width of the registration mark, the splicing tape and the registration mark are detected by the same sensor depending on the detection time or detection length of the sensor. (In an actual packaging machine, the tape width to be detected is set). A dedicated sensor may be provided as a sensor for detecting the registration mark.

  The web-shaped packaging film Fw that is bent into a substantially cylindrical shape when passing through the cylinder making device 5 then passes through the center seal device 6, and at that time, the overlapped portions where the both side edge portions of the packaging film are superimposed on each other. The cylindrical sealing film Ft is formed by applying the center seal. The cylindrical packaging film Ft is then end-sealed by the end sealer 7 between the articles P, whereby the pillow packaging body Bp is manufactured. The end sealer 7 can incorporate a cutter (a well-known one, not shown here) that cuts the packaging film and individually separates the pillow package Bp in the end-sealed region. In the horizontal bag making filling and packaging machine 1, in order to send the article P into the web-like packaging film Fw bent by the cylinder making machine 5, the feeding conveyor 8 is combined.

  The center seal device 6 includes a paper drawing roller unit 10, a heating bar heater unit 20, a pressure roller unit 30, and a weight roller unit 40 in order from the upstream side of the packaging film. The paper drawing roller section 10 includes a pair of rollers 11 and 12, and both side edge portions (overlapping portions) of the web-shaped packaging film Fw formed in a substantially cylindrical shape are overlapped between the peripheral surfaces of the rollers 11 and 12. ) Fe and Fe are sandwiched. The rollers 11 and 12 receive the driving force supplied from the paper-drawing servomotor 13 and are rotated at a speed synchronized with each other in the opposite direction. Accordingly, the web-like packaging film Fw is drawn by receiving the pulling force acting on both side edge portions Fe and Fe sandwiched between the peripheral surfaces of the rollers 11 and 12 from the rollers 11 and 12. It is sent to the bar heater unit 20 for heating arranged immediately after the wake side.

  The bar heater 20 for heating is a pair of elongated rectangular parallelepiped (block) -shaped along the direction in which the side edge portions Fe and Fe are fed so that the side edge portions Fe and Fe of the web-shaped packaging film Fw pass between them. Heater bars 21 and 22 are provided. The bar heater unit 20 also includes an opening / closing servo motor 23 for bringing the pair of heater bars 21 and 22 close to each other or separating them. The heater bars 21 and 22 have built-in heat generating means (heaters) embedded therein, and radiant heat is emitted from the opposed surfaces of the heated heater bars 21 and 22 so that the heater bars 21 and 22 are connected to each other. Both side edge portions Fe and Fe of the web-like packaging film Fw passing through the gap are heated. When the opening / closing servo motor 23 is driven, the heater bars 21 and 22 are opened and closed, so that the gap amount between the heater bars 21 and 22 can be easily adjusted according to the type, material, thickness, etc. of the packaging film, for example. it can.

  Immediately after the downstream side of the bar heater section 20, a pressure roller section 30 is disposed. The pressure roller 30 part is provided with pressure rollers 31 and 32 that are arranged with their peripheral surfaces close to and opposed to each other so as to sandwich both side edge portions Fe and Fe of the web-like packaging film Fw heated by the bar heater part 20. The pressure rollers 31 and 32 provide center sealing by sandwiching and pressing the side edge portions Fe and Fe of the web-like packaging film Fw heated by the bar heater 20. The bent packaging film Fw is formed into a cylindrical packaging film Ft by applying a center seal. Since the pressure roller section 30 is not provided with a driving means, the pressure rollers 31 and 32 are not driven to rotate by power, but rotate following the feeding of the side edge portions Fe and Fe that are pressure bonded. The peripheral surfaces of the pressure rollers 31 and 32 have a smooth cylindrical surface shape with no basis weight. The pressure roller section 30 includes an opening / closing servo motor 33 for moving the pressure rollers 31, 32 closer to or away from each other, and the opening / closing operation of the pressure rollers 31, 32 is controlled by driving the opening / closing servo motor 33. Further, the pressure contact force applied to the side edge portions Fe and Fe is adjusted by the pressure rollers 31 and 32.

  A weighting roller portion 40 is disposed immediately after the downstream side of the pressure roller portion 30. The weighting roller unit 40 includes a pair of weighting rollers 41 and 42 that sandwich both side edge portions Fe and Fe on which the heat sealing of the cylindrical packaging film Ft is performed, and a drive for driving the weighting rollers 41 and 42. Servo motor 43. The weighting rollers 41 and 42 are supplied with a driving force from the driving servomotor 43 and are rotated at a speed synchronized with each other in the opposite direction to convey the packaging film. The rotation speeds of the weighting rollers 41 and 42 are basically synchronized with the output of the paper drawing servo motor 13 of the paper drawing roller unit 10, but the ratio can be changed. Circumferential grooves such as sealing eyes are formed on the peripheral surfaces of the weighting rollers 41 and 42, and mesh with each other with both side edge portions Fe and Fe having heat sealing therebetween. If it is a general film, it will be sealed just by pinching because it is just after sealing, but it is possible to heat with a built-in heater in the case of a film that is difficult to see such as a thick packaging film It is. An end sealer 7 is disposed at the next stage of the weighting roller section 40.

  The horizontal bag making and packaging machine 1 controls each part in accordance with the packaging operation from the feeding of the packaging film and the article P to the packaging of the article P by the packaging film. A motor (not shown) for driving the embedded conveyor 8, a paper-drawing servomotor 13 for the paper-drawing roller unit 10, an opening-closing servomotor 23 for opening and closing the heater bars 21 and 22 in accordance with the transfer of the packaging material, A servo motor 33 for opening and closing the pressure roller unit 30, a servo motor 43 for driving the weight roller unit 40, and a controller 9 for controlling the driving of the end sealer 7 are provided. In the bar heater unit 20, the control unit 9 controls the operation of the opening / closing servomotor 23 so that the rotation output of the opening / closing servomotor 23 is converted into the opening / closing operation of the heater bars 21, 22 by the motion conversion mechanism 51 described later. Both side edge portions Fe and Fe of the packaging film sandwiched between the heater bars 21 and 22 are heated for sealing.

  FIG. 3 is an enlarged plan view showing the main part from the paper drawing roller part to the weighting roller part in the horizontal bag making filling and packaging machine shown in FIG. About the paper drawing roller part 10, the pressure roller part 30, and the fabric weight roller part 40, since the code | symbol same as what is shown in FIG.1 and FIG.2 is attached | subjected to the component, description for the second time is abbreviate | omitted. As a device for facilitating the passage of the paper spliced portion to the center seal device 6, the inlet sides of the heater bars 21 and 22 into which the side edge portions Fe and Fe of the packaging material relatively enter are directed upstream. A tapered opening 26 is provided, which has a large opening toward the wake side, and the opening gradually narrows. The taper opening 26 is formed by arranging the taper surfaces 24 and 25 to face the heater bars 21 and 22, respectively. By adopting such a taper structure on the inlet side of the bar heater portion 20, when the paper splicing portion enters between the heater bars 21 and 22 with the progress of the overlapping portion of the packaging material, the paper splicing portion in which the thickness of the packaging material is increased. Is guided by the taper opening 26 and smoothly enters between the heater bars 21 and 22 without hitting, collapsing, or catching on the inlet side ends of the heater bars 21 and 22.

  4 is a perspective view showing an example of a bar heater unit provided in the center seal device shown in FIG. 3, and FIG. 5 is a four-side view showing details of the bar heater unit of the center seal device shown in FIG. 5A and 5B are top views, FIG. 5C is a view seen from the packaging material feeding direction, and FIG. 5D is a side view. As shown in FIGS. 4 and 5, the bar heater unit 20 includes a stay 27 that supports the open / close servo motor 23 that opens and closes the heater bars 21 and 22 on the lower side and the motion conversion mechanism 51 is assembled on the upper side. . The stay 27 is attached to an apparatus frame 28 of the packaging machine. In addition, support plates 29a and 29b for supporting a guide shaft, which will be described later, are attached to the stay 27 below the heater bars 21 and 22 and in a direction orthogonal to the traveling direction of the packaging film (a direction in which the packaging film is sandwiched horizontally). It has been.

  Between the support plates 29a and 29b, the two guide shafts 52 and 52 are parallel to each other and at the same height in a direction perpendicular to the traveling direction of the packaging film (a direction in which both side edge portions Fe and Fe of the packaging material are sandwiched). Is provided. Two mounting blocks 53, 53 are slidably disposed across the guide shafts 52, 52. One connecting member 54 is attached to one mounting block 53, and the connecting member 54 is slidably provided on one guide shaft 52. The other connecting member 54 is attached to the other mounting block 53, and the connecting member 54 is slidably provided on the other guide shaft 52. In the connecting members 54, 54, a long hole 55 having a long axis in a direction parallel to the traveling direction of the packaging film at a point-symmetrical position with respect to the axis A located at the center of the two guide shafts 52, 52. 55 is formed. Therefore, the mounting block 53 and the connecting member 54 have a point-symmetric structure and arrangement around the vertical axis A. The heater bars 21 and 22 are attached to the attachment blocks 53 and 53 via heat insulating materials 58 and 58. In addition, although the connection member 54 was demonstrated as a member different from the attachment block 53, you may comprise it as an attachment block which united the quantity member.

  The vertical axis A coincides with the central axis of the output rotation axis of the opening / closing servomotor 23. A rotation bar 56 is attached to the output shaft 23a of the opening / closing servomotor 23 at its center position, and the fitting pins 57 protrude in an upward direction at both ends of the rotation bar 56 sandwiching the center of the output shaft 23a. , 57 are provided. The fitting pins 57 and 57 are fitted in the long holes 55 and 55 of the connecting members 54 and 54. Accordingly, when the opening / closing servo motor 23 is operated to rotate the output shaft 23a, the rotation bar 56 is also rotated, and the fitting pins 57, 57 are moved in the long holes 55, 55. The connecting members 54 and 54, and therefore the mounting blocks 53 and 53 and the heater bars 21 and 22 move on the guide shafts 52 and 52 toward or away from each other on the guide shafts 52 and 52 according to the rotation direction of the output shaft 23a. 5A corresponds to the opened state of the heater bars 21 and 22, and FIG. 5B corresponds to the closed state of the heater bars 21 and 22. FIG.

FIG. 6 is a block diagram illustrating an example of a control unit that controls a center seal device provided in the bag making filling and packaging machine illustrated in FIG. 1. The control unit 9 receives the setting signal 61 based on the setting value set by the setting / display unit 60 and the detection signal 63 from the paper splicing part detection sensor 62 to detect that the paper splicing part has been detected. A control signal for controlling the operation of the opening / closing servomotor 23 of the unit 20 is output. In the setting / display unit 60, the operator sets the value of the gap amount G (shown in FIG. 4 or FIG. 5) between the heater bars 21 and 22 according to the specification of the packaging film and the packaging operation status (ambient temperature and packaging speed) . The value of the set shift number NSc to be counted from the detection of the paper splicing part by the paper splicing part detection sensor 62 and the setting torque Ts to be output by the opening / closing servo motor 23 when the paper splicing part passes through the bar heater section 20. Set the value of.

  The shift number is a number that is counted every time the packaging film is sent by the length of one bag after the paper joint detection sensor 62 detects the paper joint of the packaging film. Specifically, Counts when the registration mark sensor (which may also be used as the paper splice detection sensor 62) detects a registration mark (corresponding to one packaging cycle) printed on the packaging film for each length of one bag. Up is done. That is, the count is started every time a wrapping film of the length of one bag is sent after the paper splicing portion detection sensor 62 detects the splicing portion and starts counting according to the first packaging cycle. . The set shift number is the number of registration marks assigned to the packaging film extending from the position where the paper splice portion detection sensor 62 is disposed to the position where the heater bars 21 and 22 are disposed. Therefore, the fact that the shift number is equal to the set shift number indicates that the paper splicing portion detected by the paper splicing portion detection sensor 62 has moved to the heating position of the heater bars 21 and 22.

  The control unit 9 outputs a method selection signal 64 indicating that a control method, that is, a position control method or a torque control method is selected as an operation control of the opening / closing servo motor 23, and selects the opening / closing servo motor 23. Control with the selected control method. When the control method is the position control method, the control unit 9 outputs a position command signal 65 for instructing the position of each of the heater bars 21 and 22, drives the opening / closing servo motor 23 by position control, and the heater bar 21 and 22 are controlled to take the commanded position. When the control method is the torque control method, the control unit 9 outputs a torque command signal 66 for instructing the driving torque value of the opening / closing servo motor 23, and the opening / closing servo motor 23 is driven by the commanded torque. Control to do.

  FIG. 7 is a flowchart showing an example of the operation of the control unit shown in FIG. After the start of the flowchart, first, it is determined whether or not the flag indicating that the seam portion of the packaging film has been detected is 1 and the undetected state is 0 (step 01; “S01”). Abbreviated to "." When the determination in S01 is YES, that is, when the paper splicing portion is not detected, it is determined whether or not the paper splicing portion detection sensor 62 is ON (S02). If the paper splice portion detection sensor 62 is not ON, the flow exits (out). If the paper splicing part detection sensor 62 is ON in the determination of S02, that is, if a paper splicing part passing through the sensor 62 is detected, the shift number NS as the number of registration marks is set to 0 (S03). Then, for this shift number, the setting shift number NSc preset by the operator in the setting / display unit 60 is read, and the set value is set in NSc (S04). The flag is set to 1 in accordance with the set shift number NSc (S05). If the determination is NO in S01 (that is, the flag is 1) or if the flag is set to 1 in S05, whether or not the registration mark sensor is ON, that is, the registration mark of the packaging film is It is determined whether the registration mark sensor is passed (S06). If the determination in S06 is NO, the process is out of this flow. If the determination in S06 is YES, it means that the registration mark has been detected, and accordingly, the shift number NS is incremented by 1 (counted up) (S07).

Next, it is determined whether or not the added shift number NS is equal to the set shift number NSc (S8). If it is determined in S08 that the shift number NS is equal to the set shift number NSc, the control unit 9 controls the opening / closing servo motor 23 because the paper splicing portion of the packaging film passes through the bar heater unit 20. The system is switched from the position control system up to that time to the torque control system (S09), and the set torque is further set to Ts (S10), and the process goes out of the flow. In the torque control method, since the set torque Ts is set to a small value, when the paper splicing portion passes the bar heater unit 20, the heater bars 21 and 22 can pass the paper splicing portion against the set torque Ts. Can be opened. Since the taper openings 26 are formed in the heater bars 21 and 22 by the taper surfaces 24 and 25, the paper spliced portion smoothly enters the taper opening 26 and comes into contact with the heater bars 21 and 22. , 22 can be pushed open, and the heater bars 21 and 22 having the gap can be passed with low resistance. If the shift number NS is not equal to the set shift NSc in the determination in S08, that is, if the shift number has not reached the set shift number NSc, the process proceeds to the determination in S11, and the shift number NS is also determined in the determination in S11. Since it is not equal to the number obtained by adding 1 to NSc, it goes out of the flow.

After it is determined in S08 that the shift number NS is equal to the set shift number NSc, the packaging film advances, and when the registration mark sensor detects the passage of the next registration mark in S06, the shift number in S07 accordingly. NS is incremented by 1 (counted up). In S08, the count-up shift number NS is INO a equal to the set number of shifts NSc, proceeds to S11 is judged NO, the equal to the number of shift number NS is obtained by adding 1 to the set number of shifts NSc in S11 Is determined , and this determination is YES. S08 the determination is that if the determination at S08 of again after a which was YES is NO, the registration mark sensor registration mark again after the control system of the opening-closing servo motor 23 is migrated to the torque control system In this case, the control unit 9 switches the control method of the open / close servo motor 23 from the torque control method to the position control method (YES) in S11. In step S12, the shift number NS is further reset to 0 (S13). Thereafter, the flag is returned to 0 (S14), and the process goes out of this flow. If the determination in S08 other than immediately after the determination in S08 is switched from YES to NO is NO, the determination in S11 is also NO and the process is out of this flow. Regarding the determination formula of S11, the flow of the flow is the same even if the shift number NS is greater than the set shift number NSc (NS> NSc).

  FIG. 8 is an operation chart corresponding to the flowchart shown in FIG. 7, which is the operation of the control unit shown in FIG. As shown in FIG. 8, in the initial operation state of the bag making and filling and packaging machine, the detection signal of the paper splicing part detection sensor 62 does not detect the paper splicing part. The control method 23 is a position control method, and the positions of the heater bars 21 and 22 are at a gap setting position corresponding to the gap amount G. When the paper splicing part detection sensor 62 detects a paper splicing part, a sensor output corresponding to that fact appears. After that, when the registration mark sensor (which may also be used as the paper splicing part detection sensor 62) detects the registration mark, the shift number NS is set to 1 corresponding to the packaging cycle (0 to 1 is added), and further Thereafter, every time the registration mark sensor detects a registration mark, 1 is added to the shift number NS.

  When the shift number NS is 5 and equal to the set shift number NSc, it is assumed that the paper splicing portion detected by the paper splicing portion detection sensor 62 passes in the packaging cycle. Therefore, the control unit 9 outputs a signal for switching the control method of the opening / closing servomotor 23 in the packaging cycle to the torque control method. In the packaging cycle, the initial positions of the heater bars 21 and 22 are the same as before, but the opening / closing servo motor 23 is driven with a set torque Ts with a small position holding force acting in the closing direction, and the splicing portion is moved. When passing, the heater bars 21 and 22 are slightly pushed open against the opening / closing servomotor 23. After the paper splicing portion has passed, the heater bars 21 and 22 are returned to the gap setting position by the opening / closing servomotor 23 driven by the value of the set torque Ts. Further, in the next packaging cycle corresponding to the detection of the next registration mark, the shift number NS is reset, and the control method of the opening / closing servomotor 23 is switched to the position control method.

  As described above, according to the center seal device of the bag-filling and packaging machine, when the wrapping film is to be joined, it is possible to know in advance the timing at which the joined portion passes through the bar heater portion 20, so that this timing is matched. Thus, by switching the control system of the servo motor 23 for opening / closing the bar heater unit 20 to the torque control system and setting the set torque value as a relatively small torque value to reduce the position holding force acting in the closing direction, the heater bar 21, 22 is allowed to be spread without causing a large running resistance against the paper splicing portion. Therefore, it is possible to apply a center seal that keeps the minimum sealing performance by heating the overlapping part of the packaging material, so that the conveyance path is not soiled, and the paper splicing part stops the bag making filling packaging machine. Since it passes through the bar heater section 20, the continuous operation of the bag making filling and packaging machine can be performed.

  Moreover, in this bag making filling and packaging machine, the servo motor control method is always the position control method, although it is the same bag making filling and packaging machine according to the properties of the article to be packaged and the type and nature of the packaging material. Alternatively, it is possible to switch the control mode for selecting whether to use the position control method or the torque control method in accordance with the timing when the paper splicing portion passes through the gap between the heater bars. That is, when packaging an article that is an article to be packaged such as food sprinkled with powder or food with a fluid such as jam, the paper splicing portion passes through the gap of the heater bar as described above. The center seal device is controlled by selecting a control mode in which the position control method is changed from the position control method to the torque control method in which the position holding force acting in the closing direction of the heater bar is weakened according to the timing. If the article is a normal article without powder or fluid, or if the packaging material is thin and the thickness of the paper splice does not increase so much, the powder or fluid does not exist at all. However, by forming the center seal with sufficient strength, there is no possibility of powder or fluid leaking out of the center seal part. You can use that to control Lumpur apparatus, operation performance of the bag making and filling and packaging machine can be enhanced.

DESCRIPTION OF SYMBOLS 1 Horizontal bag making filling packaging machine 2 Film supply source 3 Paper feed roller 3
3a Drive side roller 3b Driven side roller 4 Paper feed servo motor 5 Cylinder (former) 6 Center seal device 7 End sealer 8 Feeding conveyor 9 Control unit 10 Paper drawing roller unit 11, 12 Roller 13 Paper drawing servo motor 20 Bar heater unit 21, 22 Heater bar 23 Opening / closing servo motor 23a Output shaft 24, 25 Tapered surface 26 Tapered opening 27 Stay 28 Device frame 29a, 29b Support plate 30 Pressure roller unit 31, 32 Pressure roller 33 Opening / closing servo motor 40 Roller portion 41, 42 Weight roller 43 Drive servo motor 51 Motion conversion mechanism 52, 52 Guide shaft 53, 53 Mounting block 54, 54 Connecting member 55, 55 Long hole 56 Turning bar 57, 57 Fitting pin 58, 58 Thermal insulation Material 60 Setting / display part 61 Input Signal 62 Paper splicing part detection sensor 63 Detection signal 64 Method selection signal 65 Position command signal Bp Pillow package P Article A Vertical axis (point symmetry axis)
Fr Film roll Fw Web wrapping film Ft Cylindrical wrapping film Fe, Fe Side edge portion G Gap amount NS Shift number NSc Set shift number Ts Set torque

Claims (10)

Two heater bars that are arranged opposite to each other with a gap therebetween and that are superposed on the side edge portion extending in the longitudinal direction of the packaging material when the overlapping portion passes through the gap, and the heater bar is usually position-controlled. A bar heater unit having a servo motor as a drive source that is driven to open and close by a method, and a motion conversion mechanism that converts a rotation output of the servo motor into an opening and closing operation of the heater bar, on the downstream side in the feed direction of the packaging material of the heater bar A pressure roller section that performs center sealing by pressing the superposed portion that is arranged and heated, and a control section that controls the drive of the servo motor to cause the heater bar to perform the opening and closing operation,
The control unit weakens the position holding force that acts in the closing direction of the heater bar from the position control method to the servo motor control method in accordance with the timing at which the splicing portion of the packaging material passes through the gap of the heater bar. A center seal device in a bag making filling and packaging machine, wherein the torque control method is switched to the above. In the torque control method, as the output torque of the servo motor, when the paper splicing part passes through the gap between the heater bars, the paper splicing part pushes the heater bar through and passes through the paper splicing part. 2. The center seal device in a bag-filling-packaging machine according to claim 1, wherein a small set torque is set so that the heater bar can quickly return to its original position. The center seal of the packaging material is continuously performed through a packaging cycle assigned to each packaging material portion corresponding to one bag, and the switching of the control method of the servo motor to the torque control method is as follows. The center seal in the bag making and filling packaging machine according to claim 2 , wherein the centering is performed in units of the packaging cycle including the paper splicing portion when the paper splicing portion passes through the gap between the two heater bars. apparatus. From the wrapping cycle after said paper splicing portion has passed between said two heater bar, the said control system of the servo motors to claim 3, characterized in that it is returned from the torque control mode to the position control system The center seal apparatus in the bag making filling and packaging machine described. A set shift number is set as the number of the packaging cycles allocated to the packaging material extending from the placement position of the joint portion detection sensor for detecting the joint portion of the packaging material to the placement position of the heater bar. ,
The control unit starts counting the number of shifts in accordance with the first packaging cycle after detecting the paper splicing portion, and the number of shifts added every time the packaging cycle is changed is the set shift number. The center seal device in the bag making and filling and packaging machine according to claim 3 or 4 , wherein the control method is switched in response to reaching. A setting / display unit is provided for the operator to set the control unit,
6. The manufacturing method according to claim 5, wherein a value as a normal gap amount between the heater bars, a value of the set shift number, and a value of the set torque can be set in the setting / display unit. Center seal device for bag filling and packaging machine. The motion conversion mechanism includes a rotation bar attached to the output shaft of the servo motor, fitting pins provided at both ends of the rotation bar across the output shaft center, and the overlapping portion of the packaging material. Two guide shafts provided in parallel to the sandwiching direction, and an attachment that is guided by the two guide shafts and can move in a direction approaching and moving away from each other and in which a fitting hole is formed to fit the fitting pin With blocks,
The center seal device for a bag-filling-packaging machine according to any one of claims 1 to 6, wherein the heater bar containing the heater is attached to the attachment block via a heat insulating material. The heater bar is provided with a taper having a large opening on an inlet side into which the packaging material enters relatively, and an opening gradually narrowing as the entering packaging material progresses. The center seal apparatus in the bag making filling packaging machine as described in any one of claim | item 1 -7. The bag making filling and packaging machine has a cylindrical shape by applying the center seal to the overlapped portion where both side edges of the belt-shaped packaging material bent into a substantially cylindrical shape as the packaging material are overlapped by the center seal device. Horizontal type bag making and filling machine in which a packaging material is formed, an article to be packaged is filled in the cylindrical packaging material, and pillow packaging is performed by end sealing the cylindrical packaging material before and after the article Or it is a vertical bag-making filling and packaging machine, The center seal apparatus in the bag-making filling and packaging machine as described in any one of Claims 1-8 characterized by the above-mentioned.   The servo motor always includes a control mode that is the position control method, and a control mode that is changed from the position control method to the torque control method in accordance with the timing when the splicing portion passes through the gap of the heater bar. The center seal device in the bag making and filling and packaging machine according to claim 9, wherein the center seal device can be switched between.

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