JPH0534109U - End seal device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an end seal device capable of obtaining a desired seal strength while receiving a small reaction force at the moment of contact between both sealers. [Structure] A lower end sealer 31 placed on a lower support stand 33 and an upper end sealer 30 supported by an upper support stand 36 are integrated via a guide rod 35. The upper end sealer is guided by a guide pin 49 arranged upright on the upper surface thereof to move up and down with respect to the upper support base, and is urged downward by an elastic restoring force of a coil spring 50 arranged around the guide pin. Then, the film is clamped between both sealers. Further, the guide pin is arranged so as to be able to contact the cylinder rod 53 of the air cylinder 52 arranged above it, and the cylinder rod extending at a predetermined timing causes the upper sealer to move further downward through the guide pin. A large biasing force is applied to the coil spring.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an end seal device incorporated in a packaging device.

[0002]

[Prior Art]

 Generally, in a horizontal type automatic wrapping machine, the product to be packaged is transported at predetermined intervals, and during the transportation, the heat-meltable film is bent, overlapped, or formed into a predetermined shape. A package is manufactured by surrounding the periphery of the packaged product with heat and then heat-sealing the polymerized edge of the film and cutting a predetermined part. As a device for such sealing, a vertical sealing device that normally heat seals in the same direction as the film advancing direction, and a horizontal sealing device (end sealing device) that consists of a pair of upper and lower sealers that seal in the direction orthogonal to the advancing direction. ) And the end seal device has a built-in cutter means to perform cutting simultaneously with lateral sealing.

[0003]

[Problems to be solved by the device]

 By the way, the sealing strength of the part that is heat-sealed by the end-sealing device is the time when heat sealing (the time when a pair of sealers holds the film), the heating temperature, and the film sandwiching between both sealers when sealing. It is determined by the three factors of the applied pressure. The longer the time, the higher the temperature, and the higher the pressure, the stronger the sealing strength. However, it is difficult to adjust the heating time because the heating time is determined by the shape configuration of the device. Therefore, in reality, two factors, particularly the temperature conditions that are easy to control, are controlled to obtain the optimum sealing strength according to the film material.

However, when the film used is a material having a good heat shrinkability or a material weak to heat such as a shrink film, the sealing temperature cannot be increased so much. Therefore, conventionally, in order to surely obtain the seal strength for the film, the applied pressure is increased. Specifically, the pressure of the coil spring installed on the upper sealer is increased.

That is, as shown by the chain double-dashed line in FIG. 9, the end faces 1a, 2a of the upper sealer 1 and the lower sealer 2 partly lap in the up-down direction in the unloaded state (before contact). As shown by the solid line in the figure, the upper sealer 1 is pushed up against the coil springs 4 provided on the upper sealer 1 by hitting the film 3 as it is. .. Then, the elastic restoring force of the coil spring 4 urges the upper sealer 1 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 overlapping amount d of the end faces 1a and 1b of both sealers 1 and 2 described above becomes large, and the pushing amount of the upper sealer 1 at the moment when the end faces 1a and 2a abut each other. In addition, a large reaction force is applied from the coil spring 4, and a great amount of force is applied to both sealers 1 and 2. Therefore, there is a high possibility that both the sealers 1 and 2 and the mechanical system that drives them will be damaged in a relatively short time. Moreover, a motor having a large capacity must be used in order to rotate and drive both sealers 1 and 2 against the strong pressure. In addition, there is a problem that a metal noise is generated every time the end faces 1a and 2a of the two sealers 1 and 2 hit each other, resulting in noise.

The present invention has been made in view of the above background, and an object of the present invention is to receive a small reaction force at the moment when the upper and lower sealers come into contact with each other and to operate with a small power source. It is an object of the present invention to provide an end seal device which is low in noise and can obtain a desired seal strength.

[0008]

[Means for Solving the Problems]

 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, which are opposed to each other with a heat-fusible film sandwiched therebetween, and the end faces of both sealers are provided with the film. A first biasing means such as a spring that is pressed through the spring is provided. Further, a second biasing force that exerts a greater biasing force on the film than the first biasing means when the end faces of the sealers are pressed against at least one of the sealers via the film. A means is provided.

[0009]

[Action]

 A predetermined part of the film containing the packaged product is sandwiched between the upper and lower sealers. When the end faces of the two sealers hit each other, the biasing force of the second biasing means is not exerted, so that only the relatively weak biasing force of the first biasing means is resisted, and the sealer is contacted immediately. The reaction force received by is small. Then, when both sealers are in contact with each other in this manner, the second biasing force is activated to apply a relatively strong biasing force between both sealers. Thereby, a large clamping force can be applied to the film, and a seal having desired strength is provided.

[0010]

【Example】

 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an example of a packaging device to which the end seal 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 conveys a product to be packaged 3 in which an item 2 is stored in a tray 1 with an upper portion opened at predetermined intervals. The end seal device 5 according to the present invention is disposed in front of the conveying device 4 in the traveling direction, and the raw film 8 around which the strip-shaped film 7 is wound is disposed above the conveying device 4, and the end seal device 5 is further provided. A shrink tunnel 10 is provided on the carry-out end side of the device 5.

As the band-shaped film 7, a film material having low gas permeability, that is, having good gas barrier property and high heat shrinkability, for example, BDF-2050 (manufactured by Cryovac Co.) is used. Then, the strip-shaped film 7 becomes a tubular film 7'which is formed into a tubular shape by the bag-making device 14 disposed at the intermediate point of the transport device 4 via the pull-out roller 12 and the plurality of tension rollers 13. The to-be-packaged product 3 is further fed while being accommodated in the tubular film 7'in order.

The transporting device 4 transports only the article to be packaged 3 and sequentially feeds the article to be packaged 3 into the tubular film 7 ′. It is arranged in the vicinity of the unloading side of the first carrying device 15 and is composed of a second carrying device 16 for carrying the article to be packaged 3 together with the tubular film 7 '. The first transfer device 15 is composed of an endless chain 18 laid on a pair of sprockets 17, 17 and fingers 19 arranged at predetermined intervals of the endless chain 18.

On the other hand, a center seal device 20 for sealing the overlapping end portion 7a of the tubular film 7'is disposed below the vicinity of the loading side of the second transport device 16. This center seal device 20 is a device for heat-bonding by superposing and heating the polymerized ends 7a of the tubular film 7'from both sides thereof to heat and melt the film bonding surface. It has the structure shown in FIG. That is, it is composed of a heating roller 21 having a relatively large diameter and a receiving roller 22 having a small diameter which is arranged to face the heating roller 21 with the overlapping end 7a interposed therebetween. Then, three annular projections 23 are formed on the side peripheral surface of the heating roller 21, and the tubular film is formed between the three projections 23 and the receiving roller 22 having a flat side peripheral surface. The overlapping end 7a of 7'is sandwiched and heated to prevent heat from being applied to the entire surface of the overlapping end 7a, and the amount of heat applied to the film is reduced.

That is, in this example, since the film material used has high heat shrinkability (shrinks to about 50 to 60% before shrinkage), if the heating amount is large, the polymerization end 7a shrinks too much and the polymerized end 7a becomes round. However, the thickness of that part will increase, and it will not be possible to perform a complete hermetic end seal in a later step as it is, but by suppressing the heating amount as described above, the center seal part will be flat, The end seal is made sure. The overlapping end 7a sealed by the center seal device 20 has a substantially flat shape with three vertically extending seal portions 7a 'formed as shown in an enlarged view in FIG.

The end seal device 5 according to the present invention will be described below. In this example, the end seal device 5 is a so-called box motion type device, and an upper sealer 30 and a lower part which are vertically arranged with a tubular film 7 ′ interposed therebetween. The sealers 31 and 31 are provided with a sealer 31. The sealers 31 and 31 are shown in FIG. It is designed to rotate and move along the locus shown. That is, the two ends 30a and 31a sandwich a predetermined portion of the tubular film 7 ', and move in parallel along the transport of the tubular film 7'for a certain section.

A specific mechanism for moving the sealers 30 and 31 along a predetermined locus is as shown in FIGS. 3 to 5. That is, first, at the lower predetermined position of the tubular film 7 ', an elongated substantially flat plate-shaped lower support base 33 is arranged so as to extend in a direction orthogonal to the traveling direction thereof. It is possible to move forward and backward as well as up and down. The lower end sealer 31 is attached to the upper surface of the lower support base 33. Further, disk-shaped cam floors 34, 34 are attached to both ends of the lower support base 33, and the cam floors 34 are coupled with grooved cams (not shown) to restrict the movement of the lower support base 33, and the above-mentioned predetermined The lower support table 33, that is, the lower sealer 31, is moved along the locus.

Further, a pair of guide rods 35, 35 are installed upright in the vicinity of both ends of the lower support base 33, and move in synchronization with the movement of the lower support base 33. .. An elongated substantially flat plate-shaped upper support 36 is slidably mounted on the guide rods 35, 35 along the rod axis. Specifically, the 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, L-shaped mounting plates 39 are placed on the upper surfaces of both ends of the upper support base 36, and two sets of rotary rollers 40 are arranged on the outer side surface of the L-shaped mounting plate 39 in the vertical direction. The guide rod 35 is sandwiched by a pair of rotating rollers 40, 40. That is, in this example, the upper support base 36 can be vertically moved in a stable state by the one bearing 38 and the four rotating rollers 40 that contact the one guide rod 35. Further, cam floors 41, 41 are provided at both ends of the upper support base 36, and similar to the lower support base 35 described above, the upper support base 36 is rotationally moved in a predetermined locus by a cam groove (not shown). It is like this.

Further, the upper support base 36 has a rectangular window portion 42 that vertically penetrates in a central portion thereof, and the upper sealer 30 is inserted and arranged in the window portion 42. The upper sealer 30 is configured to rotate along with the rotation of the upper support base 36 and move up and down with respect to the upper support base 36 at a predetermined span. That is, as shown in FIG. 5, first, flat plate-like connecting plates 43, 43 are attached to predetermined positions on the upper surface of the upper sealer 30. The width of the connecting plate 43 is set larger than the width of the window portion 42 formed on the support base 36. As a result, the window 42 and the connecting plate 43 are engaged with each other to prevent the upper sealer 30 from falling from the upper support 36.

Two pairs of side walls 44, 44 are erected on the side edges of the upper surface of the upper support base 36 in the longitudinal direction, and a top plate 45 is installed on the upper ends of the side walls 44. Then, screw holes 46, 46 are formed at both ends of the top plate 45, and a bolt 47 having a through hole 47a is screwed into the screw hole 46. Further, a nut 48 for preventing rotation is attached to the bolt 47. A guide pin 49 standing upright on the connecting plate 43 is inserted in the through hole 47a of the bolt 47, and the guide pin 49 is guided by the through hole 47a to move up and down. Thus, the upper sealer 30 also moves up and down with respect to the upper support base 36.

Furthermore, a coil spring 50 as a first biasing means is arranged around the guide pin 49, and the upper and lower ends of the coil spring 50 are respectively connected to the lower end of the bolt 47 and the connecting plate 43. Abutting. The elastic restoring force of the coil spring 50 urges the upper sealer 30 downward. In this example, the urging force generated by the coil spring 50 can be adjusted by vertically moving the bolt 47. It is like this. In this example, the urging force generated by the coil spring 50 (elastic restoring force of the spring) is set to be as small as possible, and both sealers 30, 31a at the moment when the end faces 30a, 31a of both sealers 30, 31 abut. The force applied to 31 is made small.

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

Further, a hole 55 is formed in the central portion of the top plate 45, and an operating rod 56 is arranged so as to be vertically movable so as to be inserted through the hole 55, and the operation thereof is performed. 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, one end of a swing rod 59 is connected to the lower end of the operating rod 56, and the other end of the swing rod 59 is arranged on the lower support stand 33 so as to be movable up and down and inside the upper support stand 36. It is in contact with the push-up pin 60 penetrating through. That is, when the push-up pin 60 rises, the other end of the swing rod 59 is biased upward, whereby the swing rod 59 rotates about the fulcrum 61 and one end of the swing rod 59, that is, the cutter 58 descends. Then, the cutter 58 shown in the figure projects downward from the end surface 30a of the upper sealer 30. On the other hand, when the push-up pin 60 descends, the upward biasing force acting on the other end of the swinging winding 59 is released, and the elastic restoring force of the spring 57 raises the operating rod 56, that is, the cutter 58. , Goes into the upper sealer 30.

Further, in this example, as shown in FIG. 1, an endless belt 63 is provided around the lower sealer 31 so as to extend over a large number of fixed and movable pulleys 62 a and 62 b, and the lower sealer 63 can be moved back and forth. As the moving pulley 62b moves in synchronization, the space 63a of the endless belt 63 formed around the lower sealer 31 moves back and forth in synchronization with the movement of the lower sealer 31. ..

Further, in this example, the film pressing member 65 is connected to the front surface of the upper sealer 30 of the end seal device 5 in the traveling direction. The film holding member 65 is made of a rectangular sponge, and its shape is set smaller than the planar shape of the tray 1.

Next, the operation of the above-described embodiment will be described. First, the strip film 7 is continuously pulled out from the raw film 8 and guided to the bag making device 14, where it is formed into a tubular shape. It becomes a tubular film 7 '. On the other hand, the article to be packaged 3 is pushed to the finger 1, conveyed at predetermined intervals, and successively supplied into the tubular film 7 '. While being conveyed in this state on the second conveying device 16, the center sealing device 20 heat seals the overlapping ends 7a of the tubular film 7'in the middle thereof.

When it 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 manufacture the intermediate package 66. At this time, in the present invention, first, the end faces 30a, 31a of both sealers 30, 31 which rotate and move in a predetermined locus abut against each other with the tubular film 7'in between, and press the tubular film 7'with a predetermined pressure, Heat at the same time. At the time of this abutment, in this example, the elastic restoring force of the coil spring 50 is weakened as described above, so the reaction force generated between the sealers 30 and 31 is weakened, and as a result, both ends are smoothly moved with relatively small force. The surfaces 30a and 31a abut each other with the tubular film 7'in between. However, the sandwiching force between the sealers 30 and 31 generated by the coil spring 50 cannot give sufficient sealing strength to the tubular film 7 '.

While the two sealers 30 and 31 move forward in this state for a certain period, the air cylinder 52 is operated and the cylinder rod 53 is extended during the movement. Then, the guide rod 49 is pushed by the cylinder rod 53 and tries to move downward. As a result, the upper sealer 30 connected to the guide pin 49 is also urged downward, and tries to push the lower sealer 31 downward. Due to the reaction force generated from the lower sealer 31 at that time, a pressure is generated between the sealers 30 and 31 to obtain the desired sealing strength for the tubular film 7 '. Since the urging force generated by the air cylinder 52 is applied to both sealers 30 and 31 in the contact state, even if the urging force is large, there is almost no damage to both sealers 30 and 31, and no noise is generated. There is no occurrence. In this way, the tubular film 7'is reliably heat-sealed. Therefore, heat sealing is surely performed. Simultaneously with the heat sealing, the cutter 58 is moved downward to cut the heat sealed portion, thereby manufacturing the intermediate packaging body 66. The above-mentioned operation timing of the air cylinder 52 is determined by detecting contact between the upper sealer 30 and the lower sealer 31 by means of various sensors such as a limit switch.

Further, in this example, before the end seal device 5 performs end-sealing on the rear side in the traveling direction of the article to be packaged 3, as shown in FIG. 6, the holding member 65 holds the upper surface of the tubular film 7 ′. It is designed to be urged downward so that it is recessed inward. As a result, the manufactured intermediate package 66 has a recessed upper surface as shown in FIG. 7, and the amount of gas existing therein is reduced.

Next, the intermediate package 66 is fed into the shrink tunnel 10. Since the upper side of the shrink tunnel 10 has a particularly high temperature, the cylindrical film 7'contracts significantly especially at the upper surface portion. As a result, as shown in FIG. 8, the film portion located on the upper opening side of the tray 1 becomes taut. At the same time, the gas existing in the intermediate package 66 thermally expands, but as the position of the upper surface of the film rises, it flows into the newly defined upper space 67, so that the upper surface of the film expands above the tray 1. I will not put it out.

As a result, the shrink-wrapping body 68 in which the tubular film 7 ′ is heat-shrinked and is in close contact with the tray 1 is manufactured. Since the manufactured shrink wrapping body 68 is a completely sealed bag having no through hole formed therein, there is a possibility that the nitrogen gas or the like filled in the shrink wrapping body 68 will flow out to the outside by using the gas replacement device together. In addition, since the gas barrier property of the film material is also good, nitrogen gas does not leak out from the film surface.

In addition, in the above-mentioned embodiment, an example in which it is applied to a shrink wrapping device using a special film is shown, but the present invention is not limited to this, and a normal shrink wrapping device is not limited to this. That is, it can be applied to various types of packaging devices. Further, the first and second biasing means are not limited to the coil spring and the air cylinder described above, but various members can be used.

Furthermore, in the above-described embodiment, an example in which the first and second biasing means are both provided on the upper sealer has been described, but the present invention is not limited to this, and the lower sealer side, Alternatively, it may be provided on both sides, and further, one of the first and second biasing means may be provided on the upper sealer and the other may be provided on the lower sealer. is there.

[0033]

[Effect of the device]

 As described above, in the end seal device according to the present invention, when the upper and lower sealers strike, only the comparatively weak urging force of the first urging means is resisted, so that the end seal device receives the reaction at the moment of contact. The force is low, damage to both sealers can be prevented, and it can be operated with a small power source, and the noise generated at the time of impact can be reduced.

Further, once both sealers are in contact with each other, a relatively stronger biasing force than the second biasing force is applied between both sealers, so that a large pinching force can be applied to the film, which ensures that Moreover, a desired sealing strength can be obtained.

[Brief description of drawings]

FIG. 1 is a view showing an example of a packaging device to which an end seal device according to the present invention is applied.

FIG. 2 is a view showing a center seal device which is a position constituting member 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.

5 is a cross-sectional view taken along the line VV of FIG.

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

FIG. 7 is a diagram showing an intermediate package.

FIG. 8 is a diagram showing a package.

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

[Explanation of symbols]

 5 End Sealing Device 7'Cylindrical Film 30 Upper Sealer 31 Lower Sealer 50 Coil Spring (First Biasing Means) 52 Air Cylinder (Second Biasing Means)

Claims (1)

[Scope of utility model registration request] 1. An end-seal device for laterally sealing the film between the articles to be packaged while continuously transferring the heat-fusible film containing the articles to be packaged at predetermined intervals. An end seal device is provided on an upper sealer and a lower sealer, which are opposed to each other with the film sandwiched therebetween, and at least one of those sealers, and a first spring or the like that presses the end faces of both sealers against each other through the film. And a biasing means provided on at least one of the both sealers, and a greater biasing force than the first biasing means to the film when the end faces of both sealers are in pressure contact with each other through the film. An end seal device including a second urging means that emits the light.