JP2553756Y2 - End seal device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end seal device incorporated in a packaging device.

[0002]

2. Description of the Related Art In general, in a horizontal automatic packaging apparatus, articles to be packaged are conveyed at predetermined intervals, and a heat-meltable film is folded, overlapped, or formed into a predetermined shape during the conveyance. A package is manufactured by surrounding the periphery of the article to be packaged with heat, and then heat-sealing the overlapping edge of the film and cutting a predetermined portion. And as a device for performing such sealing, usually,
A horizontal seal device (end seal device) composed of a vertical seal device that heat seals in the same direction as the film traveling direction and a pair of upper and lower sealers that seals in a direction perpendicular to the traveling direction.
In addition, the end sealing device has a built-in cutter means for cutting simultaneously with the lateral sealing.

[0003]

Incidentally, the sealing strength of the part heat-sealed by the end sealing device is determined by the time during which the heat is sealed (the time when the pair of sealers sandwich the film), the heating temperature, and the sealing temperature. Sometimes it is determined by the three factors of the pressing force holding the film between the two sealers, each having a longer time, a higher temperature, and the higher the pressure, the stronger the sealing strength. However, since the heating time is determined by the configuration of the apparatus, it is difficult to adjust the heating time. Therefore, in practice, by controlling two factors, in particular, a temperature condition that is easily controlled, an optimum sealing strength is obtained according to the material of the film.

However, when the film to be used is made of a material having good heat shrinkage or a material weak to heat, such as a shrink film, the sealing temperature cannot be raised so much. Therefore, conventionally, in order to reliably obtain the sealing strength for such a film, the pressing force has been increased. Specifically, the pressure of the coil spring provided in the upper sealer is increased.

That is, as shown by a two-dot chain line in FIG. 9, the end surfaces 1a and 2a of the upper sealer 1 and the lower sealer 2 are partially wrapped in the vertical direction (before the contact) in a no-load state. The upper sealer 1 is pushed up against the coil spring 4 provided on the upper sealer 1 as shown by a solid line in FIG. Then, due to the elastic restoring force of the coil spring 4, the upper sealer 1 is urged toward the lower sealer 2 with a predetermined pressure, whereby the film 3 is heat-sealed.

However, when the pressure of the coil spring is increased, the end surfaces 1a and 1b of the sealers 1 and 2 described above are increased.
Overlap amount d of the end faces 1a,
At the moment when the two seals 2a come into contact with each other, the upper sealer 1 has a large push-up amount and receives a strong reaction force from the coil spring 4, so that a large force is applied to both the sealers 1 and 2.
Therefore, there is a high possibility that both the sealers 1 and 2 themselves and the mechanism for driving them are damaged in a relatively short time. In addition, a large-capacity motor must be used to rotate the sealers 1 and 2 against the strong pressure. Furthermore, the end faces 1a,
Each time 2a strikes, there is a problem that a metallic sound is generated and noise is generated.

The present invention has been made in view of the above background, and has as its object the purpose of receiving a small reaction force at the moment when the upper and lower sealers come into contact with each other, enabling operation with a small power source and noise. Another object of the present invention is to provide an end seal device which is small in size and can obtain a desired seal strength.

[0008]

In order to achieve the above-mentioned object, in the end seal device according to the present invention, at least one of an upper sealer and a lower sealer opposed to each other with a heat-fusible film interposed therebetween is provided. First biasing means such as a spring for pressing the end faces of both sealers through the film is provided. Further, a second urging means for generating an urging force larger than the first urging means against the film when the end faces of the both sealers are in pressure contact with at least one of the both sealers via the film. It was provided.

[0009]

According to the present invention, a predetermined portion of a film including an article to be packaged is held between upper and lower sealers. When the end faces of both sealers abut against each other, the biasing force of the second biasing means is not working, so that the sealer only resists the relatively weak biasing force of the first biasing means. The reaction force is small. Next, when the two sealers are in contact with each other, the second urging force is operated to apply a relatively strong urging force between the two sealers. As a result, a large squeezing force can be applied to the film, and a seal having a desired strength is provided.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an example of a packaging device to which the end sealing device of the present invention is applied. As shown in the figure, this packaging device is a so-called horizontal pillow type shrink packaging device, and a tray 1 with an upper part expanded.
An end seal device 5 according to the present invention is disposed in front of a transport device 4 for transporting a packaged product 3 in which articles 2 are stored at predetermined intervals, and a belt-like device is provided above the transport device 4. An original film 8 around which the film 7 is wound is provided,
Further, a shrink tunnel 10 is provided on the discharge end side of the end seal device 5.

As the belt-like film 7, a film material having low gas permeability, that is, good gas barrier property and high heat shrinkage, for example, BDF-2050 (manufactured by Cryovac) is used. Then, the band-shaped film 7 becomes a cylindrical film 7 ′ formed into a cylindrical shape by a bag-making device 14 disposed at an intermediate point of the transport device 4 via the draw-out roller 12 and the plurality of tension rollers 13, The packaged articles 3 are further transported in a state of being sequentially supplied and stored in the cylindrical film 7 '.

The transporting device 4 transports only the packaged product 3 and sequentially supplies the packaged product 3 into the cylindrical film 7 ′. A second transporting device 16 is disposed in proximity to the unloading side of the first transporting device 15 and transports the article to be packaged 3 together with the tubular film 7 ′. The first transfer device 15 includes an endless chain 18 laid over a pair of sprockets 17, 17 and the endless chain 1.
And eight fingers 19 arranged at predetermined intervals.

On the other hand, a center sealing device 20 for sealing the overlapped end portion 7a of the tubular film 7 'is provided below the vicinity of the loading side of the second transporting device 16. The center sealing device 20 is provided with a superposed end 7a of the cylindrical film 7 '.
Is heat-fused by sandwiching and heating the film from both sides thereof to heat and fuse the film bonding surface, and specifically has a structure shown in FIG. That is, a relatively large-diameter heating roller 21 and a small-diameter receiving roller 2 disposed opposite to the heating roller 21 with the overlapping end 7a interposed therebetween.
And 2. Then, three annular ridges 23 are formed on the side peripheral surface of the heating roller 21, and the cylindrical film 7 is formed between the three ridges 23 and the receiving roller 22 having a flat side peripheral surface. ', The overlapping end 7a is pinched and heated to prevent heat from being applied to the entire surface of the overlapping end 7a, thereby reducing the amount of heating of the film.

That is, in this example, the heat shrinkage of the film material used is high (shrinks to about 50 to 60% before shrinkage). Therefore, if the heating amount is large, the polymerization end 7a shrinks too much and becomes round. However, the thickness of the part increases, and it is impossible to perform a completely sealed end seal in a subsequent process as it is, but as described above, by suppressing the heating amount,
The center seal is flattened to ensure the end seal. The overlapped end 7a sealed by the center seal device 20 has three sealing portions 7 extending in the vertical direction as shown in an enlarged manner in FIG.
It is substantially flat with a 'formed.

Here, the end seal device 5 according to the present invention will be described. In the present embodiment, the device is a so-called box motion type device, and an upper sealer 30 and a lower sealer 31 which are arranged vertically with a tubular film 7 'interposed therebetween. And both of the sealers 30, 31 are provided with a cylindrical film 7 '.
End faces 30a, 31a of both sealers 30, 31 abutting against
While constantly maintaining a state in which they face each other, they rotate in a locus as shown by a dashed line in FIG. That is, the cylindrical film 7 'is moved in parallel with the conveyance of the cylindrical film 7' for a certain section while the predetermined portion of the cylindrical film 7 'is sandwiched between both end surfaces 30a and 31a.

FIGS. 3 to 5 show a specific mechanism for moving the two sealers 30 and 31 along a predetermined trajectory. That is, first, the cylindrical film 7 '
An elongated substantially flat plate-like lower support 33 is arranged at a predetermined position below the lower support 33 so as to extend in a direction orthogonal to the traveling direction. The lower support 33 is movable in the front-rear direction and the up-down direction. Has become. The lower end sealer 31 is attached to the upper surface of the lower support 33. Further, disc-shaped cam floors 34, 34 are attached to both ends of the lower support base 33, and the cam floors 34 are coupled to groove cams (not shown) to restrict the movement of the lower support base 33. The lower support 33, that is, the lower sealer 31, is moved along the locus.

A pair of guide rods 35, 35 are installed in the vicinity of both ends of the lower support 33 in an upright state, and move in synchronization with the movement of the lower support 33. An elongated, substantially flat upper support 36 is slidably mounted on the guide rods 35 along the rod axis. Specifically, a guide rod 35 is inserted through a bearing 38 into a through hole 37 provided at a predetermined position near both ends of the upper support base 36. further,
An L-shaped mounting plate 39 is placed on the upper surfaces of both ends of the upper support base 36, and two sets of rotating rollers 40 are arranged vertically on the outer side surface of the L-shaped mounting plate 39 to form a pair of rotating rollers. The guide rod 35 is held between the rollers 40 and 40. That is, in this example, one guide rod 3
The upper support 36 can be moved up and down in a stable state by one bearing 38 and four rotating rollers 40 that come into contact with 5. Further, cam floors 41, 41 are provided at both ends of the upper support base 36, and the upper support base 36 is rotated and moved along a predetermined locus by a cam groove (not shown) similarly to the above-described lower support base 35. It has become.

The upper support 36 has a rectangular window 42 penetrating vertically at the center thereof, and the upper sealer 30 is inserted and arranged in the window 42. The upper sealer 30 rotates in accordance with the rotation of the upper support base 36 and moves up and down with respect to the upper support base 36 at a predetermined span. That is, as shown in FIG. 5, first, flat connection plates 43, 43 are mounted at predetermined positions on the upper surface of the upper sealer 30. The width of the connecting plate 43 is set to be larger than the width of the window 42 formed on the support base 36. As a result, the window 42 and the connecting plate 43 are locked to prevent the upper sealer 30 from dropping from the upper support base 36.

Further, two sets of a pair of side walls 44, 44 are erected and arranged on the longitudinal side edge of the upper surface of the upper support base 36, and a top plate 45 is provided on the upper end of each side wall 44. Screw holes 46, 46 are formed at both ends of the top plate 45, and a bolt 47 having a through hole 47 a is screwed into the screw hole 46. Further, a nut 48 for preventing rotation is attached to the bolt 47. The connecting plate 4 is inserted into the through hole 47a of the bolt 47.
A guide pin 49 erected on the top 3 is inserted and arranged. When the guide pin 49 is guided by the through hole 47a and moves up and down, the upper sealer 30 also moves up and down with respect to the upper support base 36. It has become.

Further, a coil spring 50 as a first urging means is disposed around the guide pin 49, and the upper and lower ends of the coil spring 50 contact the lower end of the bolt 47 and the connecting plate 43, respectively. In contact. The upper sealer 30 is urged downward by the elastic restoring force of the coil spring 50. In this example, the urging force generated by the coil spring 50 can be adjusted by moving the bolt 47 up and down. It has become. In this example, the coil spring 50
The urging force (the elastic restoring force of the spring) generated is set as small as possible.
The force applied to both the sealers 30, 31 at the moment when the end faces 30a, 31a of the first abutment are made small.

Further, on the upper surface of the top plate 45, a support plate 51 located on the same line as the side wall 44 is erected, and the support plate 51 supports an air cylinder 52 as a second urging means. I am trying to do it. Then, the cylinder rod 53 of the air cylinder 52 is inserted into the through hole 47 a provided in the bolt 47, and when the cylinder rod 53 is extended, its distal end abuts on the guide pin 49, It is designed to urge it down.

Further, a hole 55 is formed in a central portion of the top plate 45, and an operating rod 56 is vertically movably disposed so as to pass through the hole 55. The rod 56 is constantly urged upward by a spring 57 arranged around the rod 56. A cutter 58 is suspended from the lower end of the operating rod 56, and the cutter 58 is built in the upper sealer 30. Further, the operating rod 5
The lower end of 6 is connected to one end of a swinging rod 59, and the other end of the swinging rod 59 is disposed on the lower support 33 so as to be movable up and down, and a push-up pin 60 penetrating through the upper support 36. Is in contact with That is, when the push-up pin 60 rises, the other end of the swinging rod 59 is urged upward, whereby the swinging rod 59 rotates about the fulcrum 61 and one end of the swinging rod 59, that is, the cutter 58 descends. As shown, the cutter 58 projects downward from the end surface 30a of the upper sealer 30. On the other hand, when the push-up pin 60 is lowered, the upward urging force applied to the other end of the swing winding 59 is released, and the operating rod 56, that is, the cutter 58 is raised by the elastic restoring force of the spring 57, and the upper sealer Get inside 30.

Further, in this embodiment, as shown in FIG. 1, around the lower sealer 31, a number of fixed and movable pulleys 62 are provided.
The endless belt 63 is provided between the endless belt 63 and the space 63a of the endless belt 63 formed around the lower sealer 31 by moving the movable pulley 62b in synchronization with the forward and backward movement of the lower sealer 63.
However, it moves back and forth in synchronization with the movement of the lower sealer 31.

Further, in this embodiment, a film restraining member 65 is connected to a front surface of the upper sealer 30 of the end seal device 5 in the traveling direction. This film holding member 6
Reference numeral 5 denotes a rectangular sponge whose shape is set smaller than the planar shape of the tray 1.

Next, the operation of the above embodiment will be described. First, the strip film 7 is continuously pulled out from the raw film 8 and guided to the bag making machine 14, where it is formed into a tubular shape. Film 7 '. On the other hand, the article 3 to be packaged is pushed by the finger 1, conveyed at predetermined intervals, and sequentially supplied into the tubular film 7 '. When the film is conveyed over the second conveying device 16 in this state, the overlapped ends 7a of the tubular film 7 'are heat-sealed by the center seal device 20 on the way.

When the sheet is further moved forward, the end seal device 5 heat seals and cuts the tubular film 7 'in the lateral direction at predetermined intervals to produce an intermediate package 66. At this time, in the present invention, first, the end surfaces 30a, 31a of both the sealers 30, 31 rotating and moving along a predetermined locus abut each other with the cylindrical film 7 'interposed therebetween, and pressurize the cylindrical film 7' with a predetermined pressure. Heat. In this end, in this example, as described above, the coil spring 50 is used.
Because the elastic restoring force of the sealers is weakened, both sealers 30, 3
The reaction force generated between the two becomes weak, and as a result, both end surfaces 30a, 31a abut each other with the cylindrical film 7 'interposed therebetween with a relatively small force. However, the clamping force between the sealers 30 and 31 generated by the coil spring 50 cannot provide sufficient sealing strength to the tubular film 7 '.

In this state, both the sealers 30, 31 move forward for a certain period of time. During the movement, the air cylinder 52 is operated to extend the cylinder rod 53. Then, the guide pin 49 tries to move downward by being pushed by the cylinder rod 53. As a result, the upper sealer 30 connected to the guide pin 49 is also urged downward, and attempts to push the lower sealer 31 downward. Due to the reaction force emitted from the lower sealer 31 at that time,
Pressure is generated between the sealers 30 and 31 to obtain the desired sealing strength of the tubular film 7 '. Since the urging force generated by the air cylinder 52 is applied to both the sealers 30 and 31 in the contact state, even if the urging force is large, there is almost no damage to both the sealers 30 and 31 and noise is generated. Nor. In this way,
The cylindrical film 7 'is reliably heat-sealed. Therefore, heat sealing is ensured. At the same time as the heat sealing, when the cutter 58 moves downward, the heat sealing portion is cut, and the intermediate package 66 is manufactured. The operation timing of the air cylinder 52 described above is
The detection is performed by detecting that the upper sealer 30 and the lower sealer 31 are in contact with each other by a limit switch or various other sensors.

In this embodiment, before the end sealing device 5 performs end sealing on the rear side in the traveling direction of the packaged article 3, as shown in FIG. It is designed to be urged downward to be depressed inside. As a result, the manufactured intermediate package body 66 is in a state in which the upper surface is depressed as shown in FIG. 7, and the amount of gas present therein is reduced.

Next, the intermediate package 66 is supplied into the shrink tunnel 10. This shrink tunnel 1
In the case of No. 0, since the upper side has a particularly high temperature, the upper surface portion of the cylindrical film 7 'is particularly largely contracted. As a result, FIG.
As shown in (1), the film portion located on the upper surface opening side of the tray 1 is in a taut state. At the same time, the gas present in the intermediate package 66 thermally expands, but flows into the newly defined upper space 67 as the film upper surface position rises, so that the film upper surface bulges out of the tray 1. I will not do it.

As a result, the shrink wrapped body 68 in which the cylindrical film 7 ′ is thermally contracted and adhered to the tray 1 is manufactured. Since the manufactured shrink wrapper 68 is a completely sealed bag having no through-hole, the nitrogen gas or the like filled in the shrink wrapper 68 may flow out to the outside by using a gas replacement device together. Also, since the film material has good gas barrier properties, nitrogen gas does not leak out from the film surface.

In the above-described embodiment, an example in which the present invention is applied to a shrink wrapping apparatus using a special film is shown. However, the present invention is not limited to this. It can be applied to various types of packaging devices. Further, the first and second urging means are not limited to the coil spring and the air cylinder described above, and various members can be used.

Further, in the above-described embodiment,
Although the example in which the second biasing means is provided on the upper sealer has been described, the present invention is not limited thereto, and may be provided on the lower sealer side or on both sides.
Various changes can be made such that one of the first and second urging means may be provided on the upper sealer and the other may be provided on the lower sealer.

[0033]

As described above, in the end seal device according to the present invention, when the upper and lower sealers abut,
Since only the relatively weak urging force of the first urging means is resisted, the reaction force received at the moment of contact is small, so that both sealers can be prevented from being damaged, and it can be operated with a small power source. It is also possible to reduce noise generated at the time of hitting.

Further, in a state where the two sealers are once in contact with each other, a relatively stronger urging force than the second urging force is applied between the two sealers, so that a large clamping force can be applied to the film, and the Thus, a desired seal strength can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a packaging device to which an end sealing device according to the present invention is applied;

FIG. 2 is a view showing a center seal device which is a position component of the packaging device shown in FIG.

FIG. 3 is a front view showing an embodiment of the end seal according to the present invention.

FIG. 4 is a plan view thereof.

FIG. 5 is a sectional view taken along line VV of FIG. 3;

FIG. 6 is a diagram showing one process of an operation.

FIG. 7 is a view showing an intermediate package.

FIG. 8 is a view showing a package.

FIG. 9 is a view showing a conventional end seal device.

[Explanation of symbols]

 Reference Signs List 5 end seal device 7 'tubular film 30 upper sealer 31 lower sealer 50 coil spring (first biasing means) 52 air cylinder (second biasing means)

Claims (1)

(57) [Scope of request for utility model registration] 1. An end seal device for horizontally sealing a film between articles to be packaged while continuously transferring a heat-fusible film including articles to be packaged at predetermined intervals. An end seal device is provided on at least one of the upper sealer and the lower sealer opposed to each other with the film interposed therebetween, and a first spring or the like that presses the end surfaces of both sealers against each other via the film. A biasing means, provided on at least one of the two sealers, when the end faces of the two sealers are pressed against each other via the film, a greater biasing force than the first biasing means is applied to the film. An end seal device comprising: a second urging means that emits heat.