JPH0230926B2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> The present invention includes a continuous packaging film that encloses objects to be packaged at predetermined intervals and is sealed in the longitudinal direction.
The present invention relates to an end sealing device for an automatic packaging machine that seals horizontally between the items to be packaged.

<<Prior Art>> The above-mentioned end-sealing device generally performs end-sealing by sandwiching the packaging film of the packaged object from above and below while the upper end sealer and lower end sealer rotate respectively. .

In this conventional method and apparatus, if the items to be packaged are bulky and the distance between the items is narrow, wrinkles may occur in the end seal portion of the packaging film during end sealing. This not only makes the package look bad, but also has poor sealing performance after sealing, leading to the occurrence of defective packages.

In order to prevent the occurrence of wrinkles in such a package, for example, as shown in Japanese Utility Model Application No. 58-46710,
It is also conceivable to apply a clamp piece connected by a link mechanism between a pair of press bars that open and close in the vertical direction to an end sealing device (method) that is the technical field of the present invention.

<<Problems to be solved by the invention>> However, the mechanism disclosed in the above publication
As the press bar (sealer) closes,
The crank piece gradually closes and moves outward at the same time, and the closing operation and outward movement of the crank piece are completed when the press bar is completely closed.

Therefore, if this device is applied as is to the end seal device of the present invention, the following problems will occur.

In other words, since the closing operation and the outward movement of the clamp piece are performed at the same time, the outward movement is performed before the clamp piece completely clamps the edge of the packaging film, and the clamp piece is completely closed. Until then, the clamp piece will move outward relative to the edge with contact resistance occurring between the edge and the clamp piece, and the clamp piece will reach a position where it completely clamps the edge. becomes unstable. As a result, the amount of tension on the packaging film transmitted through the clamp piece and the edge may vary, wrinkles may occur, or conversely, the film may be damaged due to excessive tension.

Furthermore, as mentioned above, when the clamp piece slides along the edge and moves relatively outward, there is a risk that the film surface will be scratched due to the contact resistance generated between the two, which reduces the aesthetic appearance and commercial value of the package. There is also a risk of harm.

In particular, when the items to be packaged are bulky or the distance between the items to be packaged is narrow, the raised portions on both sides of the packaging film are likely to buckle, making the above problem more pronounced.

The present invention has been made in view of the above-mentioned problems, and its purpose is to more reliably and accurately end-seal a packaging film without causing wrinkles in the sealed portion when sealing the packaging film in the transverse direction. An object of the present invention is to provide an end sealing method and device for an automatic packaging machine.

<<Means for Solving the Problems>> According to the end sealing method for an automatic packaging machine according to the present invention to achieve the above object, the end sealing method for an automatic packaging machine according to the present invention has a continuous end sealing method in which items to be packaged are enclosed at predetermined intervals and sealed in the longitudinal direction. In an end sealing method in which a pair of end sealers are used to sandwich the packaging film between the two end sealers when sealing the packaging film in the transverse direction between the objects to be packaged, the packaging film is sealed with both end sealers. Before pinching the packaging film, pinch the edges of the packaging film on both front and back sides of the part to be end-sealed, then pull the edges outward, and in that state seal with the end sealer on both sides. I made it.

Furthermore, in the apparatus of the present invention for carrying out the above method, an automatic packaging machine that clamps and end-seals the packaging film between the items to be packaged from above and below while the upper end sealer and the lower end sealer rotate respectively. A clamp means for clamping the edge of the packaging film is disposed on both front and rear sides of the lower end sealer so as to be openable and closable and movable in the transverse direction, and a drive means for opening and closing the clamp means, and a drive means for opening and closing the clamp means in the transverse direction. The moving means for moving are independently driven, and when the upper end sealer is lowered and before the upper and lower end sealers clamp the packaging film, the driving means is actuated to stop the clamping means. were closed to clamp the edges of the packaging film, and then the moving means was actuated to move the clamping means outwardly.

<<Examples>> Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

In this embodiment, the packaging film containing the object to be packaged is sealed at both edges thereof in the longitudinal direction, and then laterally sealed at the front and rear ends of the object to be packaged.

That is, the object to be packaged 1 is placed on the upper and lower films 2a, 2b.
and then these films 2a, 2
Both side edges 3a and 3b of b are continuously heat-sealed in the longitudinal direction and sent by conveyor 4 to the end sealing device of the present invention. In this end sealing device, an endless conveyor 5 for transporting articles is provided in front of the conveyor 4, and as shown in FIG.
The rollers a to 6k are supported in sequence, and a predetermined interval is formed between the rollers 6g and 6k. These rollers 6g and 6k are respectively mounted on shafts at the front and rear upper ends of a conveyor-stretched movable stand 7 that is approximately U-shaped.
This movable frame 7 is mounted on a floor slab 8 so as to be movable in the front and back direction.

Rotatable upper and lower end sealers 9 and 10 are provided above and inside the U-shaped opening of the movable frame 7, and these upper and lower end sealers 9 and 10 are used to seal the packaging film between the items to be packaged 1-1. 2a and 2b are held from above and below, and moved horizontally for a certain period of time while maintaining this state, and after completing cutting of the seal in the lateral direction of the packaging film, they are rotated while drawing a trajectory in a certain direction that separates them from each other. It is configured.

The movement mechanism of the end sealers 9, 10 is known, and to summarize it, as shown in FIG. 2, the upper and lower end sealers 9, 10 are respectively attached to mounting plates 11, 12. Both end shafts of the mounting plates 11 and 12 are connected to link plates 13, respectively.
-13, and is slidably supported along the slit, and has a driven roller 14-14 attached to its tip.
This driven roller 14-14 is connected to the link plate 13-13.
Cam groove 1 of cam plate 15-15 disposed on the outside of
6-16. The link plates 13-13 are respectively connected to spur gears 17-17, and these spur gears 17-17 are meshed with each other.A sprocket 18 is fixed to the shaft of the lower spur gear 17, and this sprocket 18 is connected to a drive source. They are connected by a chain and can be rotated at a predetermined speed.

Further, guide poles 19 are installed on both sides of the upper mounting plate 11 and on both sides of the lower mounting plate 12.
-19 is inserted, and this guide pole 19-19
As a result, the upper mounting plate 11 is guided toward and away from the lower mounting plate 12.

When the sprocket 18 is driven to rotate, the upper and lower spur gears 17-17 rotate in the opposite direction, and when the link plates 13-13 rotate in the opposite direction, the upper and lower mounting plates 1 are guided by the slits.
The shaft portions 1 and 12 are in the cam groove 16 of the cam plate 15-15.
-16 and is moved up and down. As a result, the mounting plates 11 and 12 move up and down along the guide poles 19-19 with the end sealers 9 and 10 facing each other. Here, the cam grooves 16-16 in which the driven rollers 14-14 of the shaft portions of the mounting plates 11, 12 engage have an arcuate portion and a horizontal portion, and the upper and lower end sealers 9, 10 are used for the packaging film 2a, When 2b is held between the upper and lower sides, the end sealer mounting plates 11 and 12 are guided by this horizontal portion, and the upper and lower end sealers 9 and 10 move horizontally at the same speed as the moving speed of the films 2a and 2b. , during this period, the packaging film 2
A, 2b are sealed in the transverse direction, and at the same time, the films 2a, 2b are cut at the center of the seal.

Next, when the driven rollers 14-14 of the end sealer mounting plates 11 and 12 come into engagement with the arcuate portions of the cam grooves 16-16, the upper and lower end sealers 9 and 10 rotate in a direction that separates them from each other. be.

The movement of the movable frame 7 in the front-rear direction is configured to be linked with the rotation of the lower end sealer mounting plate 12. This interlocking structure is well known and can be summarized as follows: As shown in FIGS. 3 and 4, a bracket 20 protruding from the lower end sealer mounting plate 12 in the front and back direction is connected to a driven roller 21-2.
1 is attached, and this driven roller 21-21 is engaged in a groove 23-23 of a vertical arm 22-22 of the movable frame 7 so as to be able to move up and down. As a result, when the lower end sealer 9 moves in the front-rear direction, the movable frame 7 also moves accordingly, and the lower end sealer 9 is raised and lowered by the driven rollers 21-
21 is moved up and down within the grooves 23-23.

Here, in the present invention, as shown in detail in FIG. 5, the vertical arm 22-2 of the concave movable frame 7
A planar U-shaped frame 24-24 on the outer surface of the upper end of 2
is fixed to the frame 24-24, and a guide shaft 25-25 extending in a direction perpendicular to the traveling direction of the packaging film is attached to the frame 24-24.
A sliding block 26-26 is slidably mounted on 25. A rotatable roller 27 is attached to the inner surface of each sliding block 26, and a connecting plate 28 is attached to the inner upper surface of each sliding block 26.
is fixed, and a tension spring 2 is connected between the upper surface of the connecting plate 28 and the outer end of the frame 24.
9 is interposed, whereby the connecting plate 28 is always urged outward. A vertical plate 30 is fixed to the inner end of each connecting plate 28,
The upper ends of a pair of air cylinders 31 and 32 are attached to the inner surface of this vertical plate 30. A bearing plate 33 is attached to the lower end of the vertical plate 30, and a shaft 36 passing through a bearing block 35 fixed to the upper surface of the outer end of the upper clamp plate 34 and a lower clamp plate 37 are attached to the bearing plate 33. A shaft 39 is attached that passes through a bearing block 38 fixed to the upper surface of the outer end. That is, the above-mentioned clamp plates 34, 37, shafts 33, 36, etc. constitute the clamp means of the present invention.

The upper surface of the inner end of the upper clamp plate 34 is connected to the U-shaped frame 4
0 to the lower end of the inner cylinder 31. A substantially square window hole 41 is bored in the center of the upper clamp plate 34, and a U-shaped frame 42, which is fixed to the upper surface of the lower clamp plate 37 through this window hole 41, protrudes upward. The lower end of the outer cylinder 32 is attached to the frame 42 .
Therefore, when the piston rod of the inner air cylinder 31 is retracted, the upper clamp plate 34 is moved against the shaft 36.
The lower clamp plate 37 rotates upward around the
When the piston rod of the outer air cylinder 32 is extended, the lower clamp plate 37 moves downward about the shaft 39 and away from the upper clamp plate 34. In other words, both air cylinders 3
Reference numerals 1 and 32 constitute the basic structure of driving means for opening and closing the clamp plates 34 and 37.

On the other hand, overhanging blocks 43 are attached to the mounting plate 11 of the upper end sealer 9 near both ends and perpendicular thereto, and cam plates 44-44 are suspended from the front and rear end surfaces of this block 43. The lower inner surface of each cam plate 44 is in a positional relationship such that it is always in elastic pressure contact with a roller 27 attached to the sliding block 26. A concave cam groove 45 is formed inside the upper part of this cam plate 44, and when the cam plate 44 descends from the state shown in FIG.
The sliding block 26 is thereby moved outward by the action of the tension spring 29, and the upper and lower clamping plates 34, which are indirectly attached thereto,
37 also begins to move outward at the same time.
That is, the roller 27, the tension spring 29
A moving means is constituted by the cam plate 44 and the like.

Although FIG. 5 of the present invention shows only one side of the upper and lower end sealers, the other side of the end sealers is similarly constructed.

Next, an end sealing method according to the present invention using the above-described apparatus will be explained.

First, the present invention clamps the front and back edges of the portion of the packaging films 2a and 2b to be end-sealed between the upper and lower clamp plates 34 and 37, and then pulls them outward and end-seals them in that state. The operation of the embodiment described above will now be explained with reference to FIGS. 6 to 8.

In the present invention, the upper and lower clamp plates 34, 37 are fixed at a predetermined timing as the end sealer rotates.
The opening and closing operations of the clamp plates 34 and 37 are performed by shortening the piston rod of the inner air cylinder 31 and extending the piston rod of the outer air cylinder 34; The closing action of the clamp plates 34, 37 is effected by extending the piston rod of the inner air cylinder 31 and shortening the piston rod of the outer air cylinder 32.
The operation of these air cylinders 31 and 32 is omitted from illustration, but a solenoid valve is operated by a command from a timing cam attached to a shaft that rotates in synchronization with the rotary shaft of the end sealer, and the compressed air source and air cylinder are operated. This is done by switching the communication state with 31 and 32.

FIG. 7 shows the rotation locus of the upper end sealer 9, and the case where the upper and lower clamp plates 34, 37 are operated in synchronization with this rotation will be described below.

First, when the upper end sealer 9 is located at point A, the upper and lower clamp plates 34 and 37 are open. The upper end sealer 9 gradually descends from this point A and when it reaches point B, the upper and lower clamp plates 3
4 and 37 are closed to sandwich the longitudinally sealed side edges 3a and 3b of the upper and lower packaging films 2a and 2b, as shown in FIG.

Next, from this point B, install the upper end sealer 9.
As the roller 27 further descends, at point C, the roller 27 shown in FIG. The upper and lower clamp plates 34, 37, which are attached via the clamp plates 34 and 37, are moved outwardly by the action of the tension spring 29. That is, at point C, the front and rear edges 3a and 3b of the end-sealed portion of the packaging film are pulled outward, and the wrinkles that are normally formed on the packaging film at this portion are stretched and disappear. It turns out.

When the packaging film is pulled from both sides in this way, the upper end sealer 9 descends to the sealing position at point D, and at the same time the lower end sealer 10 rises to the sealing position, and the upper and lower packaging films are placed between them. It clamps and moves horizontally to point E in synchronization with the movement of the packaging film. During this time, the upper and lower packaging films between the items to be packaged are end-sealed in the lateral direction, and the center portion of the end seal is cut by a cutter installed at the center of the upper and lower end sealers. When end sealing and cutting are completed at the above point E,
The upper and lower clamp plates 34, 37 are opened. Subsequently, when the upper end sealer rises and reaches point F, the roller 27 shown in FIG. Board 3
4,37 moves inward. Next, when the upper end sealer continues to rotate from point F and reaches point A, the above operation from point A to point F will be repeated again.

In the above embodiment of the present invention, the air cylinder 31,
Although an example of determining the drive timing of the lower end sealer 10 has been described, it goes without saying that the rotation locus of the lower end sealer 10 can be used.

Moreover, the roller 27 and the cam plate 44 in FIG.
The engagement relationship with the spring 29 and the spring 29 can be changed as appropriate. For example, a compression spring is used instead of the tension spring 29, the cam plate 44 is pressed against the roller 27 at the outer end face instead of the inner end face, and the cam plate 44
Even if a convex protuberance is formed in place of the concave groove 45, the same effect as in the above embodiment can be obtained.

Further, in order to move the upper and lower clamp plates 34 and 37 inward and outward, in addition to the engagement between the roller and the cam plate 44, an air cylinder is provided to move the entire member to which these clamp plates are attached. It is possible to modify the mechanism in various ways, such as operating this air cylinder in accordance with the vertical movement of the upper end sealer.

<<Effects>> As described above, in the present invention, before end-sealing, first, the front and back edges of the portion of the packaging film to be end-sealed are clamped, then pulled outward, and the ends are sealed in this state. Since the packaging film is sealed, it is possible to securely hold the packaging film at a predetermined position.

As a result, the amount of tension applied to the packaging film can be made substantially the same, and it is possible to more reliably and accurately prevent wrinkles from forming in the seal portion.

In addition, since the clamping means is pulled after being securely clamped as described above, when the clamping means moves outward, it does not move outward relative to the edge of the packaging film, and the edge There is no risk of causing any damage.
As a result, the commercial value of the package can be increased.

[Brief explanation of drawings]

FIG. 1 is a schematic side sectional view showing the mutual positional relationship between the end sealer and the movable frame of the end sealing device according to the present invention, FIG. 2 is a schematic perspective view showing the mutual relationship between the upper and lower end sealers, and FIG. FIG. 4 is a longitudinal sectional front view showing the coupling relationship between the end sealer and the movable frame, FIG. 4 is a vertical sectional side view of FIG. 3, FIG. FIG. 7 is a partial perspective view showing a state in which the packaging film is held between the upper and lower clamp plates immediately before end sealing; FIG. 8
The figure is an explanatory view showing the opening/closing and lateral movement states of the upper and lower clamp plates at each operation timing in FIG. 7. 1... Item to be packaged, 2a, 2b... Upper and lower films, 3a, 3b... Both side edges of the film, 7...
Movable frame, 9, 10...upper and lower end sealers,
11, 12...Mounting plate, 26...Sliding block,
27...Roller, 29...Tension spring, 3
1,32...Air cylinder, 34,37...
Upper and lower clamp plates, 44...cam plate.

Claims (1)

[Scope of Claims] 1. When sealing in the transverse direction between the objects to be packaged in a continuous packaging film in which the objects to be packaged are enclosed at predetermined intervals and sealed in the longitudinal direction, a pair of end sealers are used to seal the objects in the longitudinal direction. In the end sealing method of sandwiching the packaging film between both end sealers, before sandwiching the packaging film with both end sealers, pinching the front and back edges of the portion of the packaging film to be end sealed, An end sealing method for an automatic packaging machine, characterized in that the edges are then pulled outward and sealed in that state with both end sealers. 2. In an automatic packaging machine that clamps and end-seals a packaging film between items to be packaged from above and below while an upper end sealer and a lower end sealer rotate, the edges of the packaging film are placed on both the front and rear sides of the lower end sealer. A clamp means for clamping the part is disposed so as to be freely openable and closable and movable in the lateral direction, and a drive means for opening and closing the clamp means and a moving means for moving the part in the lateral direction are each driven independently, When the upper end sealer is lowered and before the upper and lower end sealers clamp the packaging film, the driving means is activated to close the clamping means to clamp the edges of the packaging film, and then An end sealing device for an automatic packaging machine, characterized in that the moving means is actuated to move the clamping means outward. 3. The clamping means is attached to each upper end surface of a movable frame having a concave cross section that moves back and forth together with the lower end sealer, and is biased inward or outward in the lateral direction by elastic means to move the clamping means. 3. An end sealing device for an automatic packaging machine according to claim 2, wherein the means has an engaging arm that moves the clamping means outwardly against the elastic means when lowered.