JP2017132502A - Top seal device and top seal method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a top seal device and top seal method capable of reducing a shock when sealing with a pair of upper and lower sealers while surely performing top sealing to a film.SOLUTION: A top seal device for energizing a pair of top sealers oppositely arranged across a film by pressure from a fluid cylinder, and sealing the film in a direction traversing the transportation direction is such that the fluid cylinder is set so as to energize by first pressure until the pair of top sealers sandwich the film and are abutted, and is set so as to energize by second pressure higher than the first pressure while the pair of top sealers sandwich the film and are abutted.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a top seal device and a top seal method.

  In the conventional horizontal automatic packaging device, the packaged goods are conveyed at predetermined intervals, the heat-meltable film is folded, overlapped, or formed into a predetermined shape during the conveyance, etc. The package body is manufactured by surrounding the packaged product and then heat-sealing the polymerization edge of the film and cutting a predetermined portion. As a device for performing such sealing, a vertical sealing device that normally heat-seals in the same direction as the film traveling direction and a top seal device (horizontal sealing device) that includes a pair of upper and lower sealers that seal the direction orthogonal to the traveling direction In addition, the top seal device has a built-in cutter means so as to cut simultaneously with the lateral seal.

  In such a top seal device, the pair of upper and lower sealers are energized with a predetermined pressure so as to sandwich the film, and are heat sealed by abutting the sealers against each other. And as an urging means of the upper and lower sealers in this case, one using a spring (coil spring) (for example, see Patent Document 1) or one using air supplied from an air cylinder (for example, see Patent Document 2) )It has been known.

  A so-called box motion type is used in order to obtain a desired sealing strength by ensuring a long sealing time and heat sealing. In this box motion type top seal device, the sealers positioned at the top and bottom move horizontally with a predetermined trajectory in a state where the seal surfaces are always facing each other, that is, in a state where both seal surfaces are in contact with each other, and then separated from each other. On the other hand, it takes a trajectory that rotates in a substantially arc shape and returns to its original position.

  By the way, the seal strength of the part heat-sealed by the top seal device is determined by the heat sealing time (the time during which the pair of sealers hold the film), the heating temperature, and the temperature of holding the film with both sealers at the time of sealing. It is determined by the three factors of pressure, each of which takes a long time, the temperature is high, and the higher the pressure, the stronger the seal strength.

  However, since the heating time is determined by the configuration of the apparatus, it is difficult to adjust the time. In addition, when the film to be used is a material having a good heat shrinkability such as a shrink film or a material weak to heat, the sealing temperature cannot be increased too much.

  Therefore, in order to reliably obtain a sealing strength for such a film, the pressure applied to the film has been increased.

Japanese Utility Model Publication No. 5-35612 JP 2000-21615 A

  However, in the conventional top seal device, whether the spring is used or air is used, the urging strength of the urging means of the sealer is constant during the box motion.

  That is, if the pressure of the film is increased (stronger) in order to obtain a reliable sealing strength, a great force is applied to both sealers at the moment when the sealing surfaces of the upper and lower sealers abut against each other. Therefore, both sealers themselves and the mechanism system that drives them are highly likely to be damaged in a relatively short time.

  Further, the top seal device may be rattled due to repeated impacts when the upper and lower sealers abut against each other via the film. When rattling occurs in the top seal device, the parallelism of the upper and lower sealers becomes non-uniform, which may cause a defective package (edge breakage) that is cut from the sealed portion after heat sealing. .

  Furthermore, every time the seal surfaces of both sealers hit each other, there is a problem that a metal sound is generated and becomes a noise.

  The present invention has been made in view of the above problems, and can reduce the impact of sealing a pair of upper and lower sealers while performing a reliable top seal (top seal, end seal) on the film. An object is to provide a top seal device and a top seal method.

  (1) The present invention seals the film in a direction transverse to the conveying direction by urging with a pressure from a fluid cylinder while moving a pair of top sealers arranged opposite to each other with a film in a predetermined locus. In the top seal device, the fluid cylinder adjusts the pressure so that the pressure is lower than the seal pressure when sealing the film when the pair of top sealers are in contact with the film sandwiched therebetween. This is a top seal device.

  According to such a structure, the impact at the time of sealing of a pair of upper and lower sealers can be reduced while performing reliable top seal (top seal, end seal) on the film.

  Thereby, damage to both sealers themselves and the mechanism system that drives them can be reduced.

  Further, rattling of the top seal device due to repeated impacts when the upper and lower sealers abut against each other via the film can be prevented. Thereby, since the parallelism of the upper and lower sealers becomes non-uniform, it is possible to prevent the occurrence of defective packaging (edge breakage) that is cut from the sealed portion after heat sealing.

  Moreover, the noise at the time of the sealing surfaces of both sealers striking can be reduced.

  (2) The present invention also includes a first flow path for supplying fluid to the fluid cylinder, a second flow path for supplying fluid to the fluid cylinder, and the downstream of the first flow path on the first flow path. A first fluid tank connected to a fluid cylinder; a second fluid tank on the second flow path and connected to the downstream fluid cylinder; the first flow path and the second flow path; Switching means capable of switching between the first and second fluid tanks, wherein the first fluid tank is capable of storing a fluid at a first pressure, and the second fluid tank is higher than the first pressure. A fluid at a second pressure can be stored, and the fluid cylinder urges one top sealer at the first pressure until the pair of top sealers abut against each other with the film interposed therebetween. Adjust the pressure to the pair of top seams Is adjusted so that the one top sealer is urged by the second pressure after contacting the film, and the one top sealer is adjusted to the first pressure by the switching means. The top seal device according to (1), wherein the low pressure state biased in step (1) and the high pressure state in which the one top sealer is biased by the second pressure are switched.

  According to such a configuration, a plurality of (two types) pressures (high pressure state and low pressure state) can be easily switched. For example, in a configuration in which a film is pressed with a plurality of pressures (biasing forces) using a spring, it is difficult to control the plurality of pressures to be switched at a desired timing during the box motion period. However, according to the present embodiment, the high pressure state and the low pressure state can be easily changed by switching the tank capable of storing the low pressure fluid (air) and the tank capable of storing the low pressure fluid (air) with a solenoid valve. Can be switched.

  (3) The present invention also includes a decompression means upstream of the first fluid tank, and the decompression means lowers the pressure in the first fluid tank in the high pressure state than the first pressure. The top seal device according to (2), wherein the pressure is reduced to a third pressure.

  (4) The present invention also includes a backflow stop means upstream of the first fluid tank, and the backflow stop means stops backflow upstream from the first fluid tank in the low pressure state. The top seal device according to the above (2) or (3), characterized in that

  According to such a configuration, when switching from the high pressure supply to the low pressure supply, the air in the air cylinder is allowed to flow into the low pressure air tank in a reduced pressure state than in the air cylinder, and the low pressure air tank is not backflowed upstream. The air stored inside can be supplied to the air cylinder (low pressure supply), and the pressure on the low pressure air tank side can be easily controlled.

  (5) The present invention is also a direction in which the pair of top sealers arranged opposite to each other with the film interposed therebetween is moved along a predetermined locus and urged by pressure from a fluid cylinder to cross the film with respect to the transport direction. A method of adjusting the pressure so that the pressure is lower than the sealing pressure when sealing the film when the pair of top sealers are in contact with the film sandwiched therebetween, and And a step of sealing the film with a sealing pressure.

  According to such a configuration, it is possible to provide a top seal method capable of reducing the impact at the time of sealing the pair of upper and lower sealers while performing reliable top seal (top seal, end seal) on the film.

  Thereby, damage to both sealers themselves and the mechanism system that drives them can be reduced. Further, rattling of the top seal device due to repeated impacts when the upper and lower sealers abut against each other via the film can be prevented. Thereby, since the parallelism of the upper and lower sealers becomes non-uniform, it is possible to prevent the occurrence of defective packaging (edge breakage) that is cut from the sealed portion after heat sealing. Moreover, the noise at the time of the sealing surfaces of both sealers striking can be reduced.

  (6) The present invention also includes a first flow path for supplying fluid to the fluid cylinder, a second flow path for supplying fluid to the fluid cylinder, and a first flow path on the first flow path. A first fluid tank capable of storing a fluid having a pressure, and a second fluid tank capable of storing a fluid having a second pressure higher than the first pressure on the second flow path. A fluid tank, and urging one top sealer with a first pressure until the pair of top sealers abut against each other with the film sandwiched therebetween; and Urging the one top sealer with the second pressure after contact, and switching the first top sealer to the first pressure by switching the first flow path and the second flow path. The low pressure state energized by the And a step of switching between a high pressure state for urging the Pushira at the second pressure, and that a top sealing method according to (5), characterized in.

  According to such a configuration, a plurality of (two types) pressures (high pressure state and low pressure state) can be easily switched. A top sealing method can be provided.

  (7) In the above (6), the present invention is characterized in that, in the high pressure state, the pressure in the first fluid tank is reduced to a third pressure lower than the first pressure. This is the top sealing method.

  (8) The present invention is also the top sealing method according to (6) or (7) above, characterized in that in the low pressure state, back flow upstream from the first fluid tank is stopped.

  According to such a configuration, when switching from the high pressure supply to the low pressure supply, the air in the air cylinder is allowed to flow into the low pressure air tank in a reduced pressure state than in the air cylinder, and the low pressure air tank is not backflowed upstream. It is possible to provide a top seal method that can supply the air stored in the air cylinder (low pressure supply), and can easily control the pressure on the low pressure air tank side.

  ADVANTAGE OF THE INVENTION According to this invention, the top seal apparatus and the top seal method which can reduce the impact at the time of sealing of a pair of upper and lower sealers can be provided, performing a reliable top seal with respect to a film.

BRIEF DESCRIPTION OF THE DRAWINGS It is the (a) front view and (b) side view which show the outline | summary of the top seal apparatus which concerns on embodiment of this invention. It is a schematic diagram for demonstrating control of the top seal apparatus which concerns on embodiment of this invention. It is a schematic diagram which shows a time-dependent change of the state of the top seal apparatus which concerns on embodiment of this invention.

  The configuration of the top seal device 10 according to the embodiment of the present invention will be described below with reference to the drawings. In addition, the “top seal” in this specification may be referred to as “lateral seal” or “end seal”. Further, in this drawing and each of the following drawings, a part of the configuration is omitted as appropriate, and the drawing is simplified. And in this figure and each subsequent figure, the magnitude | size, shape, thickness, etc. of a member are exaggerated suitably and expressed.

<Top seal device>
FIG. 1 is a diagram showing an outline of the top seal device 10, in which FIG. 1A is a front view showing a main part viewed from the conveying direction of the film YA1, and FIG. It is a side view of the sealer 31 part.

  The top seal device 10 is employed in, for example, a horizontal automatic packaging device. The horizontal automatic packaging device conveys the article (article) to be packaged at predetermined intervals, and wraps, overlaps, or forms a heat-meltable film in the middle of the conveyance. The package body (pillow package body) is manufactured by surrounding the object and then heat-sealing the polymerization edge of the film and cutting a predetermined portion.

  The top seal device 10 performs top seal and cut in the width direction of the film (packaging film) 11 (direction crossing the traveling direction T, direction crossing the film YA1) for each pitch according to the length of the package. Do. That is, the top sealing device 10 performs sealing and cutting in the width direction at a predetermined interval on the center-sealed film YA1.

  As shown in FIG. 1, the top seal device 10 of the present embodiment is a so-called box motion type device in a direction orthogonal to the traveling direction T of the film YA1 in which a packaged object is accommodated and formed into a cylindrical shape. The sealer 30 has an upper sealer 30 and a lower sealer 31 that are arranged above and below the film YA1. The sealers 30 and 31 are in contact with the film YA1. While maintaining the surfaces (end surfaces) 30a and 31a always facing each other, they are rotated and moved along a locus shown by a broken line in FIG. That is, while the predetermined part of the film is sandwiched between the sealing surfaces 30a and 31a, the film moves in parallel along the conveyance of the film in a certain section.

  A specific movement mechanism in which the sealers 30 and 31 move along a predetermined locus (for example, box motion) is as follows.

  First, as shown in FIG. 1 (a), an elongated, substantially flat lower support base 33 is disposed at a predetermined position below the film YA1 so as to extend in a direction perpendicular to the traveling direction T. The lower support base 33 is movable in the front-rear direction and the up-down direction. A lower sealer 31 is attached to the upper surface of the lower support base 33. Further, disc-shaped cam followers 34 are attached to both ends of the lower support base 33, and the cam follower 34 is coupled to a groove cam driven by a motor (not shown) to move the lower support base 33. The lower support 33, that is, the lower sealer 31 is moved along the predetermined locus.

  The upper support 36 and the lower support 33 are supported by a pair of linear guides (linear guides) L. That is, the rails 35 of the pair of linear guides L are installed upright in the vicinity of both ends of the upper support base 36 and the lower support base 33, and the vicinity of both ends of the lower support base 33 holds the rail 35. The slider 38 is fixed. Thereby, the lower support base 33 can move up and down stably. An upper and lower flat support 36 is fixed to the upper ends of the rails 35 and 35.

  Further, cam followers 41 and 41 are provided at both ends of the upper support base 36, and the upper support base 36 is fixed to a predetermined position by a groove cam driven by a motor (not shown) as with the lower support base 33 described above. It is designed to rotate around the trajectory.

  Further, the upper surface of the upper sealer 30 is fixed to an upper sealer mounting base 37 that moves up and down with respect to the upper support base 36. As a result, the upper sealer 30 rotates and moves up and down with a predetermined span with respect to the upper support 36 as the upper support 36 is rotated.

  Specifically, two power transmission rods 46 are formed upright on the top surface of the upper sealer mount 37, and the upper ends of the power transmission rods 46 are linked to the cylinder rod 53 of the air cylinder 52, The upper sealer mount 37 and the upper sealer 30 are urged downward by the cylinder rod 53.

  That is, when the upper support base 36 and the lower support base 33 come close to each other along the locus shown in FIG. 5B, the upper sealer 30 and the lower sealer 31 come into contact with the packaging film YA1. When air with a predetermined pressure (compressed air) is supplied to the air cylinder 52, the cylinder rod 53 biases the power transmission rod 46 downward according to the pressure. At this time, when the sealers 30 and 31 are already in contact, the upper sealer 30 cannot be moved any further downward, so that it is pushed toward the upper support 36 against the urging force of the air cylinder 52, An appropriate clamping force (clamping pressure) is generated between the upper sealer 30 and the lower sealer, and the film YA1 interposed between the sealers 30 and 31 is pressurized with the clamping pressure, and the heat of the sealers 30 and 31 Film YA1 is sealed.

  In the present embodiment, the urging force generated from the air cylinder 52 can be switched between a first pressure (low pressure) and a second pressure (high pressure) stronger than the first pressure.

  Further, a hole 55 is formed in the central portion of the upper support base 36, and the cylinder 56 is arranged so as to be vertically movable so as to be inserted through the hole 55, and at the lower end of the cylinder 56. The cutter 58 is suspended, and the cutter 58 is accommodated in the upper sealer mount 37 and the upper sealer 30 so as to be movable up and down. When the cutter 58 is lowered by driving the cylinder 56, the cutter 58 protrudes from the sealing surface of the upper sealer 30 as shown by a one-dot chain line in FIG. 5A, and the cutting edge enters the receiving groove of the lower sealer 31. As a result, the film YA1 is cut.

  In this way, in addition to the box motion operation described above, the top seal device 10 includes a pair of an upper sealer 30 and a lower sealer 31 that are arranged to face each other with the film YA1 sandwiched therebetween when the film YA1 is heat sealed. (In this example, the pressure is applied from the air cylinder 52). Then, the seal surfaces 30a and 31a of both sealers 30 and 31 that rotate and move along a predetermined locus are brought into contact with each other with the film YA1 interposed therebetween, and the film YA1 is pressurized and heated with a predetermined pressure, so that the film YA1 is transported. Seal in the direction transverse to

Here, the air cylinder 52 of the present embodiment is set so as to urge the upper sealer 30 with the first pressure until the upper sealer 30 abuts (contacts) with the lower sealer 31 and the film YA1. While the upper sealer 30 is in contact with the lower sealer 31 across the film YA1 (while the upper sealer 30 is in contact with the lower sealer 31 and heat-sealed), the second pressure is higher (stronger) than the first pressure. It sets so that the upper sealer 30 may be urged | biased with the pressure of. The second pressure is a sufficient pressure that can securely heat-seal the film YA1, that is, a sealing pressure, and is 3 kg / cm ² as an example. The first pressure is lower than the second pressure and higher than the atmospheric pressure, and is 2 kg / cm ² as an example.

  The urging force generated by the air cylinder 52 is applied to both sealers 30 and 31 in contact. That is, after the seal surfaces 30a and 31a of both sealers 30 and 31 are in contact with each other with the film YA1 interposed therebetween, the upper sealer 30 that is urged by a second pressure stronger than that at the time of contact is the lower sealer 31. Try to push down. The reaction force generated from the lower sealer 31 at that time generates a pressure between the sealers 30 and 31 to obtain a desired seal strength for the film YA1.

  In this state, the film YA1 is reliably heat-sealed while the sealers 30 and 31 are moved forward for a certain period. Simultaneously with this heat sealing, the cutter 58 is moved downward to cut the heat sealing portion.

  By doing so, when the upper sealer 30 and the lower sealer 31 come into contact with each other, the seal surfaces 30a and 31a come into contact with each other with the film YA1 sandwiched therebetween with a relatively small force, and both the sealers 30 and 31 come into contact with each other. Since the impact at the time can be reduced as compared with the conventional case, generation of noise can be suppressed. On the other hand, while the upper sealer 30 is in contact with the lower sealer 31 and heat-sealed, the film YA1 can be sandwiched with a force sufficient for heat-sealing, and a reliable top seal can be achieved.

<Air cylinder control>
Next, with reference to FIG. 2, control of the air cylinder that operates the top seal device 10 of the present embodiment will be described. As a control system for the air cylinder 52, the top seal device 10 includes a first flow path R1 that supplies air (compressed air) to the air cylinder 52, a second flow path R2 that supplies air to the air cylinder 52, A first air tank (low pressure air tank 87) connected to the downstream air cylinder 52 on the first flow path R1 and a second air tank connected to the downstream air cylinder 52 on the second flow path R2. An air tank (high-pressure air tank 82) and switching means 90 capable of switching between the first flow path R1 and the second flow path R2 are provided.

The low pressure air tank 87 can store air at a first pressure (for example, 2 kg / cm ² ), and the high pressure air tank 82 stores air at a second pressure (for example, 3 kg / cm ² ). It is possible.

  The switching means 90 is constituted by a solenoid valve (electromagnetic valve) 83 in this example. The switching means 90 switches between a low pressure state in which the upper sealer 30 is biased with the first pressure and a high pressure state in which the upper sealer 30 is biased with the second pressure. When a predetermined pressure is exceeded, the electronic pressure switch 84 outputs a contact signal in order to issue an alarm or stop the top seal device 10 and the automatic packaging device including the top seal device 10.

  In addition, a decompression unit 85 is provided on the upstream side of the low-pressure air tank 87 on the first flow path R1. The decompression means 85 is, for example, a relief valve 85, and decompresses the pressure in the low-pressure air tank 87 to a third pressure (for example, atmospheric pressure or higher) lower than the first pressure in a high pressure state.

  Further, on the first flow path R <b> 1, a backflow stopping unit 86 is provided on the upstream side of the low pressure air tank 87 (between the pressure reducing unit 85). The backflow stopping means 86 is, for example, a solenoid valve 86 having a check valve, and stops backflow from the low pressure air tank 87 upstream in a low pressure state.

  More specifically, a relief valve 85, a solenoid valve 86, and a low-pressure air tank 87 are provided from the upstream side to the first supply pipe 54a serving as the first flow path R1 for supplying air to the pressure chamber of the air cylinder 52. Insertion is arranged in order. Further, the second supply pipe 54b serving as the second flow path R2 for supplying air to the pressure chamber of the air cylinder 52 is inserted in this order from the upstream side into the electropneumatic regulator 81 and the high-pressure air tank 82. Has been placed. The capacity of the high pressure air tank 82 is about 10L as an example, and the capacity of the low pressure air tank 87 is about 0.3L as an example.

  The downstream ends of the first supply pipe 54 a and the second supply pipe 54 b are connected to a common solenoid valve 83. An electronic pressure switch 84 is provided between the solenoid valve 83 and the pressure chamber of the air cylinder 52.

  In the present embodiment, the upstream end of the first supply pipe 54a and the upstream end of the second supply pipe 54b are merged, but they are not merged, and the upstream end of the first supply pipe 54a is a relief. It may terminate with a valve 85.

  In the electropneumatic regulator 81 provided on the path of the second supply pipe 54b, the controller 88 controls the opening or opening / closing of the solenoid valve 81a. Since the sensor output signal (pressure value) is given from the pressure sensor 81b to the controller 88, the opening degree of the solenoid valve 81a is adjusted so that the sensor output value becomes a set value. As a result, it is possible to control the air cylinder 52 to be supplied with a constant pressure (second pressure) via the high-pressure air tank 82.

  The solenoid valve 86 provided on the upstream side of the low-pressure air tank 87 incorporates a check valve that restricts the flow from the air cylinder 52 toward the upstream side. By operating the check valve, the air cylinder 52 can be supplied with air at a constant pressure (first pressure) stored in the low-pressure air tank 87. The relief valve 85 discharges the air in the low pressure air tank 87 to the outside and controls the pressure of the air in the low pressure air tank 87.

  The solenoid valve 83 switches the air cylinder 52 between a low pressure supply for supplying air at a first pressure and a high pressure supply for supplying air at a second pressure.

<Operation control of top seal device by air cylinder>
Hereinafter, operation control of the top seal device 10 by the air cylinder 52 will be described.

  First, at the time of low pressure supply, the solenoid valve 83 communicates with the low pressure air tank 87 (the internal pressure is the first pressure (for example, 2 kg / cm 2)) so that the port of the solenoid valve 83 is disconnected from the high pressure air tank. Switch to. At the same time, the solenoid valve 83 switches the solenoid valve 86 on the upstream side of the low-pressure air tank 87 so that the check valve operates.

  As a result, the air in the low pressure air tank 87 is prevented from flowing out (reverse flow) to the upstream side, and the air stored in the low pressure air tank 87 is supplied to the air cylinder 52 via the solenoid valve 83, and the cylinder rod 53. Is pressed with the first pressure.

  The solenoid valve 83 switches to the high pressure supply after the low pressure supply has elapsed for a predetermined time. That is, the solenoid valve 83 is switched so that the port of the solenoid valve 83 is disconnected from the low pressure air tank 87 and communicates with the high pressure air tank. The solenoid valve 83 is switched so that the port of the solenoid valve 86 on the upstream side of the low-pressure air tank 87 communicates with the relief valve 85 and the check valve is inactivated.

  As a result, the air stored in the high-pressure air tank 82 (the internal pressure is always set to the second pressure (eg, 3 kg / cm 2)) is supplied to the air cylinder 52 via the solenoid valve 83. The cylinder rod 53 is pressed with the second pressure.

  At this time, the relief valve 85 is in a state where the inside of the low-pressure air tank 87 separated from the air cylinder 52 is depressurized from a predetermined low-pressure supply (for example, a pressure higher than 1 kg / cm 2 (atmospheric pressure) and lower than 2 kg / cm 2). The air in the low pressure air tank 87 is discharged outside until Hereinafter, a state in which the inside of the low-pressure air tank 87 is depressurized from the time of low-pressure supply is referred to as an excessively low pressure state.

  The solenoid valve 83 switches to the low pressure supply again after the high pressure supply has passed for a predetermined time. The solenoid valve 83 is switched so that the port of the solenoid valve 83 communicates with the low pressure air tank 87 and is disconnected from the high pressure air tank. The solenoid valve 83 switches the solenoid valve 86 on the upstream side of the low-pressure air tank 87 so that the check valve operates. As a result, the air stored in the air cylinder 52 flows into the above-described low-pressure air tank 87 through the solenoid valve 83. At this time, a check valve operates on the solenoid valve 86 on the upstream side of the low-pressure air tank 87, and the air in the low-pressure air tank 87 is prevented from flowing out (backflow) to the upstream side. In this way, the air stored in the low-pressure air tank 87 is supplied to the air cylinder 52 via the solenoid valve 83, and the cylinder rod 53 is pressed with the first pressure.

Here, the amount of air stored in the low-pressure air tank 87 and the air cylinder 52 is such that when the air flows from the high-pressure air cylinder 52 into the low-pressure air tank 87 and is filled, the internal pressure is low (2 kg / cm ² ). Thus, the amount (capacity) is appropriately selected. Further, the pressure in the excessively low pressure state is appropriately selected so that air is filled into the low pressure air tank 87 within a time during which the operation of the upper sealer 30 can be appropriately performed.

  As described above, in this embodiment, by appropriately selecting the capacity of the low-pressure air tank, the amount of air stored in the air cylinder 52, and the amount of exhaust from the relief valve 85 (pressure in an excessively low pressure state), the low pressure can be reduced from the high pressure supply. When switching to supply, the air in the air cylinder 52 is caused to flow into the low-pressure air tank 87 in a decompressed state than in the air cylinder 52, and the air stored in the low-pressure air tank 87 without flowing back upstream is used as the air cylinder. 52 can be supplied (low pressure supply).

<Changes in the state of the top seal device>
FIG. 3 is a schematic diagram showing a change in the state of the upper sealer 30 of the top seal device 10 of the present embodiment. FIG. 3A is a point on the seal surface 30a (for example, the center point in the longitudinal direction and the short direction). (B) is a transition of the pressure of the air supplied to the air cylinder 52, (c) is a schematic diagram showing a transition of the stress applied to the seal surface 30a, FIG. 4D is a schematic diagram showing a change in pressure inside the high-pressure air tank 82, and FIG. 8E is a schematic diagram showing a change in pressure inside the low-pressure air tank 87.

  The horizontal axis represents time t, which is indicated by the same time axis in FIGS.

When the top-sealed film YA1 is conveyed to a predetermined position, the upper sealer 30 starts to descend and advance by the above-described box motion moving mechanism of the upper support 36. At this time, the upper sealer 30 receives a biasing force of a first pressure (2 kg / cm ² ) from the air cylinder 52 (is in a low pressure state). Except at the time of top sealing, the upper sealer 30 receives a biasing force of a first pressure (2 kg / cm ² ) from the air cylinder 52. Further, the upper sealer 30 is in a non-contact state with the lower sealer 31 that starts to rise and move forward by the box motion moving mechanism of the lower support base 33 described above ((a) in the figure).

  Thereafter, at time t1, the solenoid valve 83 switches from low pressure supply to high pressure supply (ON).

  Time t2 is the timing at which the upper sealer 30 and the lower sealer 31 are in contact with each other. There is a slight time lag from the switching (ON) of the solenoid valve 83 at time t1 to the switching to the high pressure state, and at this timing, the urging force of the upper sealer 30 remains in the low pressure state ((b) in the figure). . That is, at time t2, the upper sealer 30 and the lower sealer 31 that are urged in a low pressure state come into contact with each other. At this time, the upper sealer 30 urged by the first pressure pushes the lower sealer 31 downward, and the reaction force generated from the lower sealer 31 ensures that the film YA1 is sandwiched between the sealers 30 and 31 ( (C) in the figure.

  If the time lag from switching of the solenoid valve 83 to switching to the high pressure state is shorter than this example, the solenoid valve 83 may be switched to the high pressure state immediately after the upper sealer 30 and the lower sealer 31 contact each other. Good.

  In any case, at the timing (time t2) when the upper sealer 30 and the lower sealer 31 contact each other, the upper sealer 30 is urged in a low pressure state.

Time t3 is the timing when the air cylinder 52 starts energizing the upper sealer 30 with the second pressure (3 kg / cm ² ) (becomes a high pressure state) (FIG. 5B). After this timing, during the high pressure state (until time t6), the upper sealer 30 urged by the second pressure stronger than that immediately after the contact pushes the lower sealer 31 downward, and the lower sealer 31 at that time Due to the reaction force generated more, a pressure (seal pressure) for obtaining the desired seal strength of the film YA1 is generated between the sealers 30 and 31 ((c) in the figure).

  In this state, the film YA1 is reliably heat-sealed while the sealers 30 and 31 move forward in a certain period. In addition, at time t4, the heat seal portion is cut by moving the cutter 58 downward.

  Thereafter, at time t5, the solenoid valve 83 switches from high pressure supply to low pressure supply (OFF). At this timing, the upper sealer 30 and the lower sealer 31 are in contact with each other, and the urging force of the upper sealer 30 remains in a high pressure state (FIGS. (B) and (c)).

Time t6 is a timing at which the air cylinder 52 again starts energizing the upper sealer 30 at the first pressure (2 kg / cm ² ) (becomes a low pressure state). At this timing, the upper sealer 30 and the lower sealer 31 are in contact with each other, and the upper sealer 30 urged by the first pressure (low pressure) pushes the lower sealer 31 downward and generates a reaction force generated from the lower sealer 31. ((B) and (c) in the figure).

  Time t7 is a timing at which the upper sealer 30 and the lower sealer 31 are separated. After this timing, the upper sealer 30 starts to rise and advance by the above-described box motion moving mechanism.

  As described above, the upper sealer 30 and the lower sealer 31 of the present embodiment are in contact with each other in a low pressure state, and are biased in a sufficiently high pressure state so that the film YA1 is sealed with a desired seal strength after the contact.

As shown in FIG. 6D, during this period, the pressure in the high-pressure air tank 82 is always kept constant (3 kg / cm ² ) under the control of the electropneumatic regulator 81. On the other hand, as shown in FIG. 5E, simultaneously with the switching of the solenoid valve 83 at time t1 (switching from low pressure supply to high pressure supply), the relief valve 85 discharges air, and the pressure in the low pressure air tank 87 is It becomes an excessively low pressure state in which the pressure is further reduced from a predetermined low pressure state (2 kg / cm ² ). The pressure in the excessively low pressure state is lower than the low pressure state and higher than the atmospheric pressure (for example, 1.2 kg / cm ^{2 to} 1.7 kg / cm ^2, etc.). When the solenoid valve 83 is switched from high pressure supply to low pressure supply at time t5, air flows into the low pressure air tank 87 from the air cylinder 52 (back flow), and the reverse flow upstream from the low pressure air tank 87 is stopped. To a low pressure state (2 kg / cm ² ).

  As described above, in this embodiment, the upper sealer 30 is urged downward at a low pressure (for example, 2 kg / cm 2) until the upper sealer 30 abuts (contacts) with the lower sealer 31, and the upper sealer 30 When heat sealing after contacting the sealer 31, the upper sealer 30 is urged downward at a high pressure (eg, 3 kg / cm 2).

  In more detail, until the upper sealer 30 abuts (contacts) the lower sealer 31 (until time t2 in FIG. 3 elapses), the upper sealer 30 is attached downward at a low pressure (for example, 2 kg / cm 2). After that, when the upper sealer 30 comes into contact with the lower sealer 31 and heat seals, the upper sealer 30 is urged downward at a high pressure (for example, 3 kg / cm 2).

  Thereby, when the upper sealer 30 and the lower sealer 31 are in contact with each other, the sealing surfaces 30a and 31a are in contact with each other with the film YA1 interposed therebetween with a relatively small force, and the impact when the sealers 30 and 31 are in contact with each other. It can be reduced compared to the prior art. In the heat sealing after contact, the upper sealer 30 is urged downward with a high pressure (sufficient sealing pressure), so that reliable heat sealing is possible.

  That is, it is possible to suppress damage (deterioration) of both sealers themselves and a mechanism system that drives the sealers due to an impact when the sealers 30 and 31 come into contact with each other. Moreover, the occurrence of rattling of the top seal device due to repeated impacts can be suppressed, and the possibility of non-uniformity in the parallelism of the upper and lower sealers is reduced, so that the seal portion after heat sealing is cut off. The occurrence of defective packaging (edge breakage) can be reduced. Furthermore, it is possible to reduce the generation of noise when the seal surfaces of both sealers abut.

  Further, when the upper sealer 30 and the lower sealer 31 are separated from each other, the low pressure state is set before that (before time t7 in FIG. 3), so that the repulsion that the upper sealer 30 receives from the lower sealer 31 can be reduced.

  Even when the upper sealer 30 and the lower sealer 31 are separated from each other, it is only necessary that the two are separated after switching to the low pressure state. The timing at which the solenoid valve 83 switches from the high pressure supply to the low pressure supply is adjusted accordingly. Selected.

  Note that the relief valve 85 is not provided upstream of the low-pressure air tank 87, and when switching from low-pressure supply to high-pressure supply, the air in the low-pressure air tank 87 is discharged to the outside so that the inside of the low-pressure air tank 87 is equivalent to the atmospheric pressure. May be.

  In the above-described embodiment, the example in which the cutter 58 is built in the upper sealer 30 has been described. However, the present invention is not limited to this and can be applied to a top seal device in which the cutter 58 is not provided. . That is, the present invention can be applied to a top seal device using a so-called fusing type sealer having both functions of a seal and a cut as well as the cutter device arranged separately from the top seal device.

  Further, the case where the upper sealer 30 is urged downward by the air cylinder 52 has been described as an example, but the lower sealer 31 may be urged upward by the air cylinder.

  Further, the top seal device 10 is not limited to heat sealing, and may be one that seals the film YA1 with ultrasonic waves.

  In the above-described embodiment, the top seal device 10 employed in the horizontal automatic packaging device has been described as an example. However, the top seal device 10 may be employed in a vertical automatic packaging device.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and technical idea thereof. That is, in the above embodiment, the position, size, length, shape, material, orientation, and the like of each component can be changed as appropriate.

  For example, in the embodiment of the top seal device, the case where the cam is driven by the motor is illustrated, but the present invention is not limited to this, and various power sources such as an air cylinder, a hydraulic cylinder, an electric or magnetic solenoid are used. Available. The power source of the upper sealer 30 and the lower sealer 31 is not limited to an air cylinder, and a hydraulic cylinder may be used.

DESCRIPTION OF SYMBOLS 10 Top seal device 30 Upper sealer 31 Lower sealers 30a, 31a Seal surface 33 Lower support base 34 Cam follower 35 Rail 36 Upper support base 37 Upper sealer mounting base 41 Cam follower 46 Power transmission rod 52 Air cylinder 53 Cylinder rod 54a Supply pipe 54b Supply pipe 56 Cylinder 58 Cutter 81 Electropneumatic regulator 81a Solenoid valve 81b Pressure sensor 82 High pressure air tank 83 Solenoid valve 84 Electronic pressure switch 85 Relief valve (pressure reducing means)
86 Solenoid valve (back flow stop means)
87 Low pressure air tank 88 Controller 90 Switching means R1 channel R2 channel YA1 film

Claims (8)

A top seal device for energizing with a pressure from a fluid cylinder while moving a pair of top sealers arranged opposite to each other with a film interposed therebetween and sealing the film in a direction transverse to the conveying direction. ,
The fluid cylinder is
When the pair of top sealers are in contact with each other with the film interposed therebetween, the pressure is adjusted to be lower than the sealing pressure when the film is sealed;
A top seal device characterized by that. A first flow path for supplying fluid to the fluid cylinder;
A second flow path for supplying fluid to the fluid cylinder;
A first fluid tank on the first flow path and connected to the downstream fluid cylinder;
A second fluid tank on the second flow path and connected to the downstream fluid cylinder;
Switching means capable of switching between the first flow path and the second flow path,
The first fluid tank is capable of storing a fluid at a first pressure,
The second fluid tank is capable of storing a fluid having a second pressure higher than the first pressure,
The fluid cylinder adjusts the pressure so as to urge one top sealer with a first pressure until the pair of top sealers abut against each other with the film interposed therebetween. Adjusting the one top sealer so as to be urged by the second pressure after being sandwiched and abutted,
The switching means switches between a low pressure state in which the one top sealer is biased with the first pressure and a high pressure state in which the one top sealer is biased with the second pressure.
The top seal device according to claim 1, wherein: A pressure reducing means on the upstream side of the first fluid tank;
The pressure reducing means reduces the pressure in the first fluid tank to a third pressure lower than the first pressure in the high pressure state;
The top seal device according to claim 2, wherein: Backflow stop means is provided upstream of the first fluid tank,
The backflow stopping means stops backflow upstream from the first fluid tank in the low pressure state.
The top seal device according to claim 2, wherein the top seal device is provided. This is a top sealing method in which a pair of top sealers arranged opposite to each other with a film interposed between them are urged by a pressure from a fluid cylinder while being moved along a predetermined locus to seal the film in a direction transverse to the transport direction. And
A step of adjusting the pressure so that the pressure is lower than the sealing pressure when sealing the film when the pair of top sealers are in contact with the film sandwiched therebetween;
Sealing the film with the sealing pressure,
A top sealing method characterized by the above. A first flow path for supplying fluid to the fluid cylinder;
A second flow path for supplying fluid to the fluid cylinder;
A first fluid tank on the first flow path and capable of storing a fluid at a first pressure;
A second fluid tank on the second flow path and capable of storing a fluid having a second pressure higher than the first pressure, and
Urging one top sealer with a first pressure until the pair of top sealers abut against each other with the film interposed therebetween;
Energizing the one top sealer with the second pressure after the pair of top sealers abuts with the film interposed therebetween;
By switching between the first flow path and the second flow path, the one top sealer is biased with the first pressure, and the one top sealer is pressed with the second pressure. And a step of switching between the high pressure state
The top sealing method according to claim 5, wherein: In the high pressure state, the pressure in the first fluid tank is reduced to a third pressure lower than the first pressure.
The top sealing method according to claim 6. In the low pressure state, the back flow upstream from the first fluid tank is stopped.
The top-seal method according to claim 6 or 7, wherein

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