JP2006193176A - Bag manufacturing and packaging machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bag manufacturing and packaging machine that can obtain a desired pressure (sealing pressure) even in case where a film is bited together with contents, dust, etc. <P>SOLUTION: The bag manufacturing and packaging machine produces a commodity packaged such that a pair of seal jaws 25a and 25b pinching a tubular film are opened or closed and a belt-like seal is formed sidewise with respect to the direction in which the film Fb flows. The bag manufacturing and packaging machine is equipped with a motor that rotates normally and reversely in order to open and close the seal jaws 25a and 25b, a link mechanism that transmits the drive force of the motor to the seal jaws 25a and 25b and increases a sealing pressure when the film is sealed, and a motor driver for controlling the drive of the motor. In accordance with the gap Δ between the pair of the seal jaws 25a and 25b during sealing the film, the rotating torque of the motor during sealing is controlled. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bag making and packaging machine that performs packaging in a so-called pillow type.

  If dust or the like adheres to the sealing jaws of the bag making and packaging machine, the sealing pressure changes to cause a sealing failure. Therefore, conventionally, a method has been adopted in which a spring is provided between the seal jaw and the link mechanism, and a constant pressure is obtained by absorbing a pressure exceeding a predetermined amount by the spring.

  However, in the method of controlling the applied pressure using a spring, changing the applied pressure requires changing the preload of the spring or replacing the spring itself, which is complicated. In particular, when the setup change frequently occurs during the production of a variety of products in small quantities, it is necessary to adjust the machine each time, and the work becomes a problem.

On the other hand, the relationship between the rotational torque of the link driving motor and the applied pressure is uniquely determined based on the geometrically determined link mechanism toggle state, and a constant applied pressure is obtained by controlling the motor torque. A method has been proposed (Patent Documents 1 and 2).
JP-A-5-000110 Japanese Patent Publication No.8-025542

  In the method of controlling the torque of the motor, for example, when the contents are sandwiched between the sealing jaws, when dust adheres to the surface of the sealing jaws, or when the thickness of the film to be produced is different, The torque of the motor assumed in design differs from the actually required torque. Therefore, this causes a seal failure.

  Accordingly, an object of the present invention is to provide a bag making and packaging machine that can obtain a desired pressure (seal pressure) even when biting of contents or dust occurs.

  In order to achieve the above object, the bag making and packaging machine of the present invention seals ends along the film flow direction with a vertical sealing device to form a film into a cylinder, and the film formed into the cylinder After the contents are filled in the bag, the pair of sealing jaws sandwiching the cylindrical film is opened and closed to produce a packaged product that is sealed in a strip shape in a direction transverse to the film flow direction. In a packaging machine, a motor that rotates forward and backward to open and close the seal jaw, a link mechanism that transmits a driving force of the motor to the seal jaw and increases a seal pressure when the seal jaw seals, and the motor A motor driver for controlling the driving of the motor, and according to the size of the gap between the pair of sealing jaws at the time of sealing, And controlling the rotation torque.

When the seal jaw is open, the motor rotates forward and the seal jaw slides in the closing direction via the link mechanism. When the seal jaw is almost closed, the movement speed of the seal jaw is “0” or “0”. Thus, sealing (welding) is performed by the sealing jaws.
At the time of this sealing, when the gap between the pair of sealing jaws is normally assumed in advance, the force is amplified by the link mechanism, and a predetermined sealing pressure is obtained. On the other hand, if the gap is larger than the value assumed in advance, the force amplification by the link mechanism becomes insufficient, so that the rotational torque of the motor is controlled to be larger than the normal time.
In this way, by controlling the rotational torque of the motor during sealing, a predetermined sealing pressure can be obtained regardless of the gap between the sealing jaws.

  In the present invention, a detecting means for detecting a physical quantity corresponding to the gap at the time of sealing is further provided, and the rotational torque of the motor at the time of sealing is controlled based on the detected physical quantity. As the physical quantity, a distance between seal jaws corresponding to the gap may be detected, but a rotation angle of a motor or a link described below may be detected.

  That is, the detection means further includes, for example, detection means for detecting an actual rotation angle of the motor when the motor stops at the time of sealing, and is based on the rotation angle of the motor detected by the detection means. Then, the rotational torque of the motor at the time of sealing may be controlled.

  In this case, if the rotation angle of the motor is a predetermined rotation angle, the motor is controlled so that a normal rotation torque is generated. When the rotation angle does not reach the predetermined rotation angle, the motor is torque controlled so that a rotation torque larger than usual is generated and a predetermined seal pressure is obtained. Thus, by controlling the rotational torque based on the rotational angle of the motor, a predetermined sealing pressure can be obtained regardless of the rotational angle of the motor during sealing.

  Further, as the detection means, for example, a detection means for detecting a rotation angle of the link of the link mechanism at the time of sealing is further provided, and based on the rotation angle of the link detected by the detection means, the detection at the time of sealing is performed. The rotational torque of the motor may be controlled.

  The position of the link mechanism's center of rotation and the length of the link cause production errors for each machine. Therefore, even if the rotation angle of the motor is a predetermined rotation angle, the gap between the sealing jaws may not be a predetermined value. On the other hand, by controlling the rotational torque of the motor based on the actual rotational angle of the link, even if there is a dimensional error for each machine in the relationship between the rotational angle of the motor and the rotational angle of the link, a predetermined seal Pressure is obtained.

In the present invention, further comprising a storage unit that stores an arithmetic expression for calculating the seal pressure to be a predetermined value based on a geometric structure of the link mechanism and a detection result by the detection unit, The rotational torque of the motor may be controlled so that the seal pressure becomes a predetermined value based on the arithmetic expression.
In this way, by performing the calculation, the trouble of storing the control values in the table can be saved.

  On the other hand, in the present invention, a storage unit for storing a control value for controlling the rotational torque of the motor at the time of sealing is provided according to a detection result by the detection unit, and the control value is read from the storage unit to read the control value. The rotational torque of the motor may be controlled.

In the present invention, the first period until the seal jaw is fully opened to the generally closed state is controlled on the basis of the rotational speed of the motor. On the other hand, the second period, which is the seal period after the generally closed state, is the Preferably, the motor is controlled on the basis of the rotational torque, and the motor is controlled on the basis of the rotational speed in the third period when the closed sealing jaw is fully opened.
Thus, by using both speed control and torque control, both high processing capacity per unit time and seal reliability can be realized.

In this case, the storage unit further stores a threshold value of the rotation angle of the motor at the time of sealing the sealing jaw, and when the motor is not rotating up to the threshold value, the sealing operation by the sealing jaw is stopped, When the motor rotates more than the threshold value, it is preferable to apply a sealing pressure during the sealing.
By controlling in this way, it is possible to avoid generation of excessive torque in the motor when a large foreign object is bitten.

Embodiments of the present invention will be described below with reference to the drawings.
In the following description, “front”, “rear”, “right”, and “left” mean “front side”, “back side”, “right side”, and “left side” in front view, respectively.

1 to 7 show Example 1. FIG.
As shown in FIG. 1, the present bag making and packaging machine 2 manufactures a packaged product B by wrapping the contents M input from above with a film (hereinafter referred to as “wrapping material”) Fb. .

overall structure:
The bag making and packaging machine 2 includes a roll support portion 21, a former 22, a pull-down belt mechanism 23, a vertical sealing device 24, a horizontal sealing device 25, and the like.
As shown by the arrow a, the strip-shaped packaging material Fa fed from the roll support portion 21 is formed into a cylindrical packaging material Fb formed by overlapping the left and right edges by the sailor 22a and the tube 22b of the former 22. Become.
The pull-down belt mechanism 23 conveys the tubular packaging material Fb downward as indicated by an arrow b while pressing the tubular packaging material Fb against the tube member 22b from the left and right sides. At the same time, the vertical sealing device 24 performs vertical sealing in the longitudinal direction (flow direction) on the overlapping portion of the cylindrical packaging material Fb.

  After the contents M are put into the cylindrical packaging material Fb, the horizontal sealing device 25 sandwiches the cylindrical packaging material Fb from both the front and rear sides, and a predetermined position of the cylindrical packaging material Fb is band-shaped in the width direction. While performing horizontal sealing, a cutter device (not shown) cuts the sealing portion to produce a product B.

Horizontal sealing device 25:
2 and 3 are schematic plan views of the lateral sealing device 25. FIG.
As shown in FIGS. 2 and 3, the horizontal sealing device 25 has a pair of front and rear sealing jaws 25 a and 25 b extending in the left-right direction. The sealing jaws 25a and 25b are repeatedly moved by the moving mechanism 40 between a proximity state in which they are close to each other during sealing and a separation (open) state in FIG. 3 as shown in FIG.

  Each of the sealing jaws 25a and 25b has a heater (not shown). The seal jaws 25a and 25b are moved to the close state so as to sandwich the tubular packaging material Fb, and the heater welds the tubular packaging material Fb to each other.

Moving mechanism 40:
As shown in FIG. 2, the horizontal sealing device 25 has a gantry 30 on which the moving mechanism 40 is mounted.
The mount 30 includes a pair of left and right side frames 31 extending in the front-rear direction, and connecting members 32 a and 32 b that connect the side frames 31 at the center side and the rear side. The gantry 30 is supported by the frame 2a of the bag making and packaging machine 2 through four brackets 33 protruding from the side frames 31, 31 to the left and right outwards.

  The moving mechanism 40 includes a pair of sliding rods 41 and base members 42a and 43. The sliding rod 41 extends in the front-rear direction along each side frame 31. The sliding rod 41 is slidably supported on the gantry 30 via a plurality of guides 44 provided on the side frame 31. Base members 42a and 43 are fixed to the front and rear ends of the sliding rod 41, respectively, and a rectangular frame is formed by the sliding rod 41 and the base members 42a and 43. A front seal jaw 25a protrudes rearward from the front base member 42a.

On the other hand, a sliding member 42b is bridged between the sliding rods 41 and 41. The sliding member 42 b is provided so as to be slidable with respect to the sliding rod 41 via a slider 45 fitted to the sliding rod 41. A rear seal jaw 25b projects from the sliding member 42b toward the front.
Accordingly, the sealing jaws 25a and 25b are set so as to be movable in the front-rear direction with respect to the side frame 31, respectively.
In order to make the drawing easier to see, the rear seal jaw 25b and its drive system members are shaded.

Link mechanism (reciprocating slider crank mechanism):
The seal jaws 25a and 25b are reciprocated in the front-rear direction by a link mechanism described below.
A gear box 49a of a servo motor 49b is fixed to the connecting member 32a on the center side. A drive shaft 46 is connected to an output shaft (not shown) of the motor 49b, and the drive shaft 46 is rotationally driven in the forward / reverse direction by the forward / reverse rotation of the motor 49b.

  A center portion of a crank 47 is fixed to the drive shaft 46. Connecting rods 48a and 48b are rotatably provided at both ends of the crank 47, respectively. A sliding member 42b is connected to the front connecting rod 48b so as to be relatively rotatable about a point O1, and a rear base member 43 is connected to the rear connecting rod 48a to be relatively rotatable.

  When the crank 47 is rotated around the drive shaft 46 in the direction of the arrow c by the rotation of the drive shaft 46, the connecting rod 48a pulls the rear base member 43 forward as shown in FIG. The front seal jaw 25a is moved forward via the front base member 42a. At the same time, the connecting rod 48b pulls the sliding member 42b rearward, and the rear seal jaw 25b is moved rearward. As a result, the seal jaws 25a and 25b change from the close state shown in FIG. 2 to the separated state shown in FIG.

  On the other hand, when the crank 47 is rotated in the reverse direction around the drive shaft 46 (in the direction of arrow d in FIG. 2), the connecting rod 48a pushes the rear base member 43 rearward and slides as shown in FIG. The front seal jaw 25a is moved backward via the rod 41. At the same time, the connecting rod 48b pushes the sliding member 42b forward, and the rear seal jaw 25b is moved forward. As a result, the seal jaws 25a and 25b change from the separated state shown in FIG. 3 to the close state shown in FIG.

  Accordingly, the two sets of link mechanisms including the crank 47, the connecting rod 48b and the sliding member (slider) 42b, and the crank 47, the connecting rod 48a and the rear base member (slider) 43 are two sets of reciprocating sliders. A crank mechanism is configured. This link mechanism constitutes a toggle joint that transmits the driving force of the motor 49b to the seal jaws 25a and 25b and increases the seal pressure by the seal jaws 25a and 25b.

  FIG. 4 is a schematic view in which front sectional views of the seal jaws 25a and 25b in each state of the proximity state correspond to the link mechanism in the state. Note that the schematic diagrams of FIGS. 4 and 5 illustrate the link mechanism on the rear side.

As shown in FIG. 4A, at a normal time assumed in design, a predetermined gap Δ is generated between the seal jaws 25a and 25b in the close state (during sealing), and the crank 47 has a predetermined crank angle (rotation of the link). Angle) θ. The crank angle θ is an angle formed by the crank 47 and a straight line (reference line) C connecting the rotation center (power point) O2 of the drive shaft 46 and the point O1.
When the thick film shown in FIG. 4B is used, when dust or the like adheres between the sealing jaws 25a and 25b of FIG. 4C, or when the contents M of FIG. The crank angle θ in the proximity state is larger than that in the normal state of FIG.

Here, the link mechanism of the bag making and packaging machine 2 constitutes a toggle joint composed of the reciprocating slider crank mechanism as described above. Therefore, as the crank 47 rotates and the value of the crank angle θ approaches 0, the force (seal pressure) applied to the slider increases rapidly.
Therefore, as shown in FIGS. 4B to 4D, when the crank angle θ is slightly larger than the predetermined value, the seal pressure is remarkably reduced.

Phase 1 to Phase 3:
Therefore, in the bag making and packaging machine 2, as shown in FIG. 6, the torque control of the motor 49b is controlled in the first period from when the sealing jaws 25a and 25b are fully opened (separated state in FIG. 3) to being generally closed (FIG. 2). In the second period (proximity state), which is the time of sealing after substantially closing, the control is divided into the third period in which the closed sealing jaws 25a and 25b are fully opened (FIG. 3). In the second period, the motor 49b is controlled based on the rotational torque, and in the first period and the third period, the motor 49b is controlled based on the speed.

FIGS. 6A to 6C are tables showing the moving speed of the sealing jaws 25a and 25b and the rotational torque of the motor over time, respectively.
In the normal time shown in FIG. 6A (FIG. 4A), in the second period, the motor 49b is rotated with a predetermined torque, and sealing is performed with a predetermined sealing pressure.
On the other hand, as shown in FIG. 6B, when a thick film is used (FIG. 4B) or when dust or the like adheres between the seal jaws 25a and 25b (FIG. 4C), the seal In order to keep the pressure at a predetermined value, the rotational torque of the motor 49b is made larger than the predetermined torque.

Torque control in the second phase:
In the second period, the bag making and packaging machine 2 controls the torque of the motor 49b as described below, and controls the seal pressure by the seal jaws 25a and 25b to be substantially constant.
The torque control is performed by detecting the crank angle θ and controlling the rotational torque of the motor 49b based on the crank angle θ.
That is, first, the crank angle θ is detected using detection means such as an encoder, and the seal pressure is calculated based on the crank angle θ. Next, the shaft torque of the drive shaft 46 is calculated so that the calculated seal pressure becomes a predetermined seal pressure. Based on the shaft torque of the drive shaft 46, the rotational torque of the motor 49b is calculated to control the torque of the motor 49b.

Calculation of shaft torque of drive shaft 46:
In FIG. 5, the angle α of the connecting rod 48b (48a) and the angle β formed between the perpendicular to the crank 47 and the connecting rod 48b can be calculated by the following equations (1) and (2), respectively.
sin α = r · sin θ / L …… (1)
β = π / 2−θ−α (2)
α: Angle formed between the reference line C and the connecting rod 48b β: Angle formed between the perpendicular to the crank 47 and the connecting rod 48b L: Length of the connecting rod 48b r: Length of the crank 47

At this time, the thrust F in the tangential direction of the crank, the thrust P in the axial direction of the connecting rod, and the seal pressure Px with respect to the shaft torque T of the drive shaft 46 are expressed by the following (3) to (5), respectively.
F = T / r (3)
P = F / cos β (4)
Px = P · cos α (5)

By using the relational expressions (1) to (5), the shaft torque T of the drive shaft 46 for obtaining a predetermined seal pressure Px can be calculated using the following expression (6). .
T = Px · r · cos α / cos β (6)
Therefore, the above equation (6) shows that the shaft torque T of the drive shaft 46 is a function f (θ) of the crank angle θ. Therefore, by detecting the crank angle θ, the shaft torque T of the drive shaft 46 for obtaining the desired pressure Px of the seal jaws 25a and 25b can be calculated.

Torque control of motor 49b:
Based on the calculated shaft torque T of the drive shaft 46, a predetermined calculation taking a reduction ratio and the like into consideration is performed, whereby the rotational torque of the motor 49b is obtained. Since this rotational torque has a predetermined correlation (generally proportional) with the drive current of the motor 49b, the desired rotational torque can be obtained by controlling the drive current to the motor 49b.
Therefore, in the second period, the seal pressure can be kept substantially constant by detecting the crank angle θ and controlling the rotational torque of the motor 49b according to the crank angle θ.

  Incidentally, as shown in FIG. 4D, when a large foreign matter such as the contents M is caught between the seal jaws 25a and 25b, the crank angle θ is increased. In such a case, if the torque control described above is performed, an excessive torque is generated in the motor 49b. Therefore, the bag making and packaging machine 2 is set to stop the sealing operation when the crank angle θ is equal to or greater than a predetermined biting threshold.

Equipment configuration:
As shown in FIG. 7, the bag making and packaging machine 2 includes a control unit (control means) 50 that controls the bag making and packaging machine 2. The control unit 50 is composed of, for example, a microcomputer, and a touch screen 56, a pull-down belt mechanism 23, a vertical sealing device 24, a horizontal sealing device 25, an encoder 28, and the like are connected to the control unit 50 through an interface (not shown). .

  The horizontal sealing device 25 includes a motor 49b, a rotary encoder 29, and a motor driver 26 for controlling driving of the motor 49b. The motor driver 26 is connected to the rotary encoder 29 and to the control unit 50. The rotary encoder 29 detects the rotation angle of the rotation shaft of the motor 49 b and sends the detected angle to the control unit 50 via the motor driver 26. On the other hand, the motor driver 26 can control the magnitude of the rotational torque of the motor 49b by varying the current value supplied to the motor 49b.

  The encoder 28 detects the crank angle θ and sends the detected angle to the control unit 50. Here, the encoder 28 constitutes an example of detection means for detecting a physical quantity with respect to the gap between the seal jaws 25a and 25b at the time of sealing.

The control unit 50 includes a CPU 51 and a memory (storage means) 52. The memory 52 is provided with an arithmetic expression storage unit 53, a product information storage unit 54, a threshold storage unit 55, and the like.
In the arithmetic expression storage unit 53, the mathematical expressions (1) to (6) for controlling the rotational torque of the motor 49b are stored in advance. As described above, these mathematical expressions are operations for performing an operation so that the seal pressure of the seal jaws 25a and 25b becomes a predetermined value based on the geometric structure of the link mechanism and the detection result by the encoder 28. It is a formula.
In the product information storage unit 54, product information including various values necessary for the production of the product B is stored in advance for each product. The threshold storage unit 55 stores a preset biting threshold.

Packaging operation:
When this system is activated, the CPU 51 reads out the arithmetic expression and the biting threshold from the arithmetic expression storage unit 53 and the threshold storage unit 55. On the other hand, when an operator selects a product to be produced by performing a predetermined operation, the CPU 51 reads product information necessary for production of the product from the product information storage unit 54, and production of the product B is started.

When the contents M are put into the cylindrical packaging material Fb of the bag making and packaging machine 2 shown in FIG. 1, the pull-down belt mechanism 23 (FIG. 1) moves the cylindrical packaging material Fb downward by the length of the bag.
Thereafter, the sealing process is started. The sealing jaws 25a and 25b in FIG. 2 are moved in the closing direction, and the cylindrical packaging material Fb into which the contents M have been put is sealed and separated, and the product 1 is produced. At the same time, a new bottom is formed at the lower end of the cylindrical packaging material Fb.

  On the other hand, due to the downward movement of the cylindrical packaging material Fb, the strip-shaped packaging material Fa is pulled out from the roll support portion 21 and wound around the tube 22b via the sailor 22a to be formed into a cylindrical shape. The overlapping portion of the strip-shaped wrapping material Fa (tubular wrapping material Fb) formed into a cylindrical shape is sealed in the longitudinal direction by the vertical sealing device 24 to form a new cylindrical wrapping material Fb.

Phase 1:
Here, in the sealing process, as shown in FIG. 6A, in the first period from the separation state of the sealing jaws 25a and 25b shown in FIG. 3 to the proximity state shown in FIG. Speed control. That is, a constant current is supplied to the motor 49b with a predetermined trigger, and the motor 49b is accelerated until the motor 49b reaches a predetermined rotation speed (0 to T1). After that, when the motor 49b is operated at a constant speed and the crank 47 rotates to a predetermined rotation angle (T1 to T2), the motor 49b generates a reverse rotational torque and stops the motor 49b (T2 to T3). , 25a and 25b are stopped at a substantially constant closed position.

Second period:
In the second period, the motor 49b rotates slightly for a predetermined minute time (T3 to T4) with a constant initial torque, and the cylindrical packaging material Fb is sandwiched between the sealing jaws 25a and 25b. Thereafter, based on the detection value from the encoder 28, the torque control described above is performed (T4 to T5).

Torque control;
That is, the CPU 51 in FIG. 7 calculates the crank angle θ in FIG. 5 based on the detection value from the encoder 28. Based on the calculated angle, the CPU 51 calculates the shaft torque T of the drive shaft 46 for obtaining a predetermined seal pressure using the above-described mathematical expressions (1) to (6) read from the arithmetic expression storage unit 53. . Next, the CPU 51 calculates, based on the calculated shaft torque T, a rotational torque of the motor 49b for generating the shaft torque T from a reduction ratio or the like. The CPU 51 causes the motor driver 26 to supply a current value corresponding to the rotational torque to the motor 49b. As a result, the motor 49b is driven with the rotational torque, whereby a substantially constant sealing pressure is obtained.

  For example, in the normal time shown in FIG. 4 (a), the crank angle θ shown in FIG. 4 (e) becomes a substantially constant value assumed in the design, so that the torque control shown in FIG. 6 (a) is performed. The rotational torque of (T4 to T5) is a substantially constant late torque. On the other hand, as shown in FIGS. 4B and 4C, for example, when a thick film is used or when dust or the like is attached, the crank angle θ shown in FIG. As shown in FIG. 6B, the rotational torque at the time of torque control (T4 to T5) is larger than the latter-stage torque at the normal time.

  The CPU 51 compares the biting threshold value read from the threshold value storage unit 55 with the crank angle θ, and when the crank angle θ is larger than the threshold value (when the motor 49b does not rotate to the threshold value), As shown in FIGS. 4D and 4G, it is determined that a large foreign matter has been caught, and the sealing operation is stopped in order to prevent an excessive torque from being generated in the motor 49b.

Third period:
Thereafter, in the third period from the proximity state shown in FIG. 2 to the separation state shown in FIG. 3, the CPU 51 again controls the speed of the motor 49b as shown in FIGS. .
That is, the motor 49b is rotated in the reverse direction, and the motor 49b is accelerated until the motor 49b reaches a predetermined rotational speed (T5 to T6). Thereafter, the motor 49b is operated at a constant speed, and when the crank 47 rotates to a predetermined rotation angle (T6 to T7), a positive rotational torque is generated in the motor 49b to stop the motor 49b (T7 to T8).

  In the first embodiment described above, the crank angle θ is detected by the encoder 28, and the rotational torque of the motor 49b is calculated based on the crank angle θ. However, in the second embodiment, the encoder 28 is not provided. That is, the crank angle θ is calculated from the actual rotation angle θM of the motor 49b detected by the rotary encoder 29, and the rotation torque of the motor 49b is calculated from the calculated crank angle θ using the above-described arithmetic expression.

  Thus, the encoder 28 for detecting the crank angle θ is not necessarily provided. However, the crank angle θ may become small or large even if the motor 49b is stopped at a predetermined rotation angle due to a mechanical error in manufacturing the moving mechanism 40 or the like. On the other hand, in the first embodiment, the crank angle θ is not calculated based on the rotation angle θM of the motor, but the crank angle θ itself is detected and the rotation torque of the motor 49b is controlled. Even if a mechanical error in manufacturing occurs, a constant sealing pressure can be obtained.

  That is, in the first embodiment, when the connecting rod 48b and the crank 47 are short, the crank angle θ at the normal time becomes a small value, so that the late torque of the motor 49b becomes a small value. When the connecting rod 48b and the crank 47 are long, the crank angle θ at the normal time becomes a large value, so that the late torque of the motor 49b becomes a large value, and the moving mechanism 40 has a manufacturing mechanical error. Even if it occurs, a substantially constant sealing pressure can be obtained.

FIG. 8 shows a third embodiment.
As shown in FIG. 8A, in this embodiment, a control value storage unit 57 is provided instead of the arithmetic expression storage unit 53 described in the first embodiment.
As shown in FIG. 8B, in the control value storage 57, the crank angle θ and a control value for controlling the rotational torque of the motor 49b are associated with each other in advance. The control value is, for example, a current value corresponding to the rotational torque of the motor 49b.
Other configurations are the same as those of the first embodiment, and the description and illustration thereof are omitted.

  In the first embodiment described above, the rotational torque of the motor 49b is controlled using an arithmetic expression so that the seal pressure becomes a predetermined value. On the other hand, in the third embodiment, when the encoder 28 detects the crank angle θ, the CPU 51 reads out the control value of the motor 49b associated with the crank angle θ from the control value storage unit 57. The CPU 51 applies torque corresponding to the control value to the motor 49b via the motor driver 26, thereby performing torque control and keeping the seal pressure constant.

  In the third embodiment, the control value storage unit 57 may store the rotation angle θM of the motor and the control value in association with each other in advance. In such a case, torque control is performed based on the rotation angle θM of the motor detected by the rotary encoder 29.

  Instead of detecting the crank angle θ and the motor rotation angle θM, another detection means for detecting a physical quantity corresponding to the gap between the seal jaws 25a and 25b at the time of sealing may be provided. As such a detecting means, for example, a distance measuring sensor that measures the distance between the sealing jaws 25a and 25b can be used. Based on the distance corresponding to the detected gap, the rotational torque of the motor 49b is controlled.

  This bag making and packaging machine can be used to manufacture products that are packed in a so-called pillow type.

It is a schematic side view which shows the bag making packaging machine concerning Example 1 of this invention. It is a schematic plan view which shows the sealing state of the horizontal sealing apparatus. It is a schematic plan view which shows the open state of the horizontal sealing apparatus. It is a front sectional view of the seal jaw in the proximity state, and a schematic diagram of the link mechanism in the state. It is a schematic diagram of a link mechanism. It is a figure which shows the relationship between the moving speed of a seal jaw, and the rotational torque of a motor. It is a schematic block diagram of the bag making packaging machine. It is a schematic block diagram which shows the bag making packaging machine concerning Example 3 of this invention.

Explanation of symbols

2: Bag making and packaging machine 24: Vertical seal device 25a, 25b: Seal jaw 26: Motor driver 28, 29: Encoder (detection means)
42b: sliding member (part of link mechanism)
43: Rear base member (part of link mechanism)
47: Crank (part of the link mechanism)
48b: Connecting rod (part of link mechanism)
49b: Motor 53: Arithmetic expression storage unit 55: Threshold storage unit 57: Control value storage unit B: Product Fa: Band-shaped packaging material (film)
Fb: cylindrical packaging material (film)
M: Contents θ: Crank angle Δ: Gap

Claims (8)

A pair of the end portions along the flow direction of the film is sealed with a vertical sealing device to form the film into a cylindrical shape, and the cylindrical film is filled with the contents and then sandwiched between the cylindrical films. In a bag making and packaging machine for producing a product that is sealed and packaged in a band shape in a direction transverse to the flow direction of the film by opening and closing the sealing jaw of
A motor that rotates forward and backward to open and close the sealing jaw;
A link mechanism for transmitting the driving force of the motor to the seal jaws and increasing a seal pressure when sealing with the seal jaws;
A motor driver for controlling the drive of the motor,
A bag making and packaging machine configured to control a rotational torque of the motor at the time of sealing in accordance with a size of a gap between the pair of sealing jaws at the time of sealing.   2. The bag making according to claim 1, further comprising detection means for detecting a physical quantity corresponding to the gap at the time of sealing, wherein the rotational torque of the motor at the time of sealing is controlled based on the detected physical quantity. Packaging machine.   2. The method according to claim 1, further comprising detection means for detecting an actual rotation angle of the motor when the motor is stopped during the sealing, and based on the rotation angle of the motor detected by the detection means. A bag making and packaging machine configured to control the rotational torque of the motor.   The rotation torque of the motor according to claim 1, further comprising detection means for detecting a rotation angle of the link of the link mechanism at the time of sealing, based on the rotation angle of the link detected by the detection means. A bag making and packaging machine designed to control.   5. The storage unit according to claim 2, 3 or 4 for storing an arithmetic expression for calculating the seal pressure to be a predetermined value based on a geometric structure of the link mechanism and a detection result by the detection means. A bag making and packaging machine that controls the rotational torque of the motor so that the seal pressure becomes a predetermined value based on the arithmetic expression.   5. The storage device according to claim 2, further comprising a storage unit that stores a control value for controlling a rotational torque of the motor at the time of sealing according to a detection result by the detection unit, and the control value is obtained from the storage unit. A bag making and packaging machine that reads and controls the rotational torque of the motor at the time of sealing.   7. The first period from when the sealing jaw is fully opened to when the sealing jaw is substantially closed according to claim 1, wherein the motor is controlled on the basis of the rotational speed of the motor, and on the other hand, when sealing is performed after the motor is substantially closed. In the second period, the motor is controlled based on the rotational torque, and in the third period when the closed sealing jaw is fully opened, the motor is controlled based on the rotational speed. In Claim 7, further comprising a storage unit for storing a threshold value of the rotation angle of the motor when the sealing jaw is closed,
In the second period, when the motor does not rotate to the threshold value, the sealing operation by the sealing jaw is stopped,
On the other hand, in the second period, when the motor rotates more than the threshold, the bag making and packaging machine is configured to apply the seal pressure to the seal jaw.

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