JP3301373B2 - Stretch wrapping machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging machine for packaging an article to be packaged in a container such as a tray.
In particular, the present invention relates to a stretch wrapping machine that folds and packs a film on the bottom surface side of an object to be wrapped.

[0002]

2. Description of the Related Art As an example of a packaging machine for packaging objects to be packaged, for example, a stretch film packaging machine 1 shown in FIG.
Then, an elevator E provided with an elevator head H that supports the packaged object 2 and can be inverted is pushed up from below with respect to the film F stretched in the horizontal direction, and the upper surface of the packaged object 2 is placed on the film F. After covering with F, the folding plate B is moved between the packaged object 2 and the elevator head H while the elevator head H is lying down, thereby folding the end of the film F to the bottom side of the packaged object 2. It is designed to be packaged in.

[0003] Before the film F is pushed up by the elevator head H, the movable film clamping means C is pre-stretched (stretched) by a pre-stretching mechanism which clamps the end of the film F before the object 2 is pushed up.
In order to fold the packaged object 2 from the side surface to the bottom surface after the packaged object 2 is pushed up, the prestretching force is relaxed (the amount of stretching is reduced).

[0004] In the packaging of articles to be packed in which a product is stored in a storage container such as a Styrofoam tray, the product may protrude upward from the storage container, but it is prestretched and tension is applied. By pressing the object to be packaged toward the film, the entire object to be packaged can be efficiently packaged, and the film can be prevented from becoming loose or wrinkled.

[0005] In recent years, in the above-mentioned stretch film wrapping machine, the size (vertical dimension, lateral dimension) of the wrapped object is determined while the wrapped object is being loaded into the wrapping machine (or before the loading is started). , Height dimension) automatically detected by the sensor,
Based on the detected size data, various kinds of packaging control data (packing conditions such as film cut length, film pre-stretch amount (stretch amount), pre-stretch loosening amount, film clamp opening timing, etc.) are automatically set, Even if the size of the article to be packaged changes, good-looking and beautiful packaging is automatically performed without adjustment by the operator.

[0006] The stretch film packaging machine 1
Then, the film F is pre-stretched largely in the width direction according to the dimensions of the product, so that a small-sized product to a large-sized product are wrapped with one kind of narrow film F. In this case, the area of the elevator head H is changed to a size corresponding to the size of the product by selecting whether or not to use the side head and automatically adjusting the interval between the head elements.

[0007]

However, the conventional stretch wrapping machine as described above has the following problems. When packaging the article to be packaged 2, the film F
When folding is performed on the bottom surface side, the film clamping means C is moved in the direction of loosening the pre-stretch (direction of approaching the packaged object 2) in conjunction with the folding plate B. In the case of a large product, the elevator head H is The movement of the film clamping means C has been limited due to the increase in the size.

On the other hand, in the case of a large product, the amount of pre-stretch is large, so that the tension applied to the product is made appropriate so that the film is released when the movement of the film clamping means C is stopped. There is a need. Therefore, in the conventional stretch wrapping machine, in the case of a large product, the movement of the film clamping means C has to be stopped at an early stage of folding to the bottom side, and the holding of the film F has to be released.

In this case, when the holding of the film F is released, the film F shrinks to return to the original size.
There is a possibility that the end (folding margin) of the film F folded into the bottom surface side of the article to be packaged 2 becomes short and packaging fails. As a result, there has been a major drawback that the size of the wrappable product is limited.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and provides a stretch wrapping machine capable of wrapping a large-sized product, that is, a large packaged product, reliably and with good appearance. The purpose is to provide.

[0011]

In order to achieve the above object, the present invention employs the following constitution. According to the first aspect of the present invention, the film cut to a predetermined length is stretched over an elevator by clamping the front and rear ends of the film by a clamp mechanism, and the packaged object placed on the elevator is placed on the elevator. After covering the upper surface of the packaged object with the film by pushing up from below with respect to the film, folding the left and right and rear end portions of the film into the bottom of the packaged object by left and right folding plates and rear folding plates, respectively. Then, in a stretch wrapping machine that folds the front end of the film while discharging the packaged object, the left and right folding plates are formed in a two-layer structure having upper and lower flat plates, respectively, and the upper and lower flat plates are formed. The rear folding plate is disposed so as to be movable in the front-rear direction, and among the clamp mechanisms, at least a rear clamp mechanism is configured to be movable in the front-rear direction,
When the elevator is lowered during the period from when the folding operation of the left and right folding plates is started to when the rear folding plate is folded, and when packaging an object to be wrapped having at least a predetermined size or more, the rear folding plate In conjunction with the folding operation , the elevator is lowered by moving the rear clamp mechanism .
Is formed between the elevator and the packaged object.
Is moved to the movement space area of the elevator,
Thereafter, the film is released from being held in the moving space area .

In the stretch wrapping machine according to the first aspect, the left and right folding plates for folding the left and right ends of the film into the bottom of the article to be packaged have a two-layer structure having upper and lower plates, respectively. By arranging the rear folding plate movably in the front-rear direction between the left and right folding plates, in the state where the left and right folding is performed, the packaged object is placed by the upper flat plate of the left and right folding plates, thereby the rear folding plate. The elevator is lowered at the time of folding the rear end of the film due to the above.

When the size of the article to be packaged is at least equal to or greater than a predetermined value, the rear clamp mechanism is moved in conjunction with the folding operation of the rear folding plate to lower the elevator.
Is moved to the movement space area of the elevator, which is formed between the elevator and the articles to be packaged in a, then the
The film is released from being held in the moving space area . That is, in the conventional stretch wrapping machine in which the left and right folding plates are constituted by a single flat plate, when folding the rear end portion of the film by the rear folding plate, the object to be packaged must be placed by the elevator. The rear clamp mechanism is moved in conjunction with the rear folding plate to an area where the rear clamp mechanism cannot be moved, and the film clamp is released in the latter half of or immediately before the end of the rear folding.

For this reason, it is not necessary to release the rear clamp at the initial stage of the post-folding as in the prior art. Even when the amount is large, a sufficient margin for folding in the rear end of the film can be obtained. In addition, since the rear clamp mechanism is moved in conjunction with the rear folding plate to a region that was not possible in the past, the deformation force applied to the packaged object by the tension of the film at the time of rear folding can be appropriately reduced. For example, when the rear clamp mechanism is not moved, the movement amount of the rear folding plate is approximately 2
A double-length film is stretched, but if the amount of movement of the rear clamp mechanism is set to about twice the amount of movement of the rear folding plate, the amount of film stretching at the time of rear folding is almost zero. Thus, the deformation force hardly acts on the packaged object at the time of folding back. On the other hand, by setting the amount of movement of the rear clamp mechanism to an appropriate value of about twice or less, it becomes possible to fold into the package while maintaining an appropriate tension at the time of rear folding. .

According to a second aspect of the present invention, in the stretch wrapping machine according to the first aspect, the clamp mechanism clamps the front and rear ends of the film cut to a predetermined length and holds the film to the packaged object. And a pre-stretching means for pre-stretching in the front-rear direction according to the size.

In the stretch wrapping machine according to the second aspect, the clamp mechanism in the stretch wrapping machine according to the first aspect has a structure in which the rear clamp mechanism is movable at least in the front-rear direction. Can be appropriately expanded to the film width or more, so that the film can be pre-stretched in the front-rear direction according to the size of the article to be packaged by using the clamp mechanism as it is. Therefore, it is not necessary to separately provide the clamp mechanism and the pre-stretch means. In addition,
The pre-stretch method is (1) a type in which the front clamp mechanism is fixed and only the rear clamp mechanism is moved, (2)
Any of a type in which the front and rear clamp mechanisms are moved at the same amount and at the same speed, and (3) a type in which the front and rear clamp mechanisms are independently moved at different amounts and / or at different speeds may be used.

The third aspect of the present invention is the first or second aspect.
In the stretch wrapping machine described above, the clamping mechanism also serves as a film transfer unit that holds the front and rear ends of the film cut to a predetermined length and transfers the film to the upper part of the elevator. It is assumed that.

In the stretch wrapping machine according to the third aspect, it is not necessary to provide the film transfer means separately from the clamp mechanism, and when the transfer of the film is completed, the front and rear ends of the film are clamped by the clamp mechanism. Can be.

According to a fourth aspect of the present invention, in the stretch wrapping machine according to the third aspect, the rear clamp mechanism clamps the front side of a position where the film is being transferred in relation to the folding operation of the rear folding plate. It is configured to be movable to the mechanism side.

In the stretch wrapping machine according to the fourth aspect, the rear clamping mechanism is moved to the inside of the position being transported to the front clamping mechanism side in relation to the folding operation of the rear folding plate. Conventionally, there is a pre-stretching wrapping machine in which the pre-stretch is loosened when the elevator is lifted or folded back to reduce the tension (deformation force) applied to the packaged object. Pre-stretching, that is, returning the previously stretched portion to its original state, did not reduce the interval between the front and rear clamping mechanisms to less than the width of the film before pre-stretching, and when trying to do it again, Could not be done because of the existence. In the present invention, since the movement of the rear clamp mechanism is not limited by the elevator, by moving the film to the front clamp mechanism side which is inside from the position being transferred, the tension adjustment at the time of rear folding is performed immediately before the end of the rear folding. It is possible to do until.

According to a fifth aspect of the present invention, in the stretch wrapping machine of the first aspect, the rear side clamping mechanism has a plurality of film clamping units, and at least one of the film clamping units is provided. In addition, it is characterized in that the film is released from being pinched after moving to the moving space area of the elevator in conjunction with the folding operation of the rear folding plate.

In the stretch wrapping machine according to the fifth aspect, the rear clamping mechanism has a plurality of film clamping means, and some of these clamping means are suitable for folding the left and right ends of the film by the left and right folding plates. By releasing the clamp at an appropriate timing, the tension applied to the packaged object at the time of folding right and left is adjusted. Therefore, there is no need to separately provide the left and right clamp mechanisms.

According to a sixth aspect of the present invention, in the stretch packaging machine according to any one of the first to fifth aspects, the rear clamp mechanism is driven substantially in synchronization with the driving of the rear folding plate. It is assumed that.

In the stretch wrapping machine according to the sixth aspect, since the rear clamp mechanism is driven substantially in synchronization with the driving of the rear folding plate, a change in tension applied to the packaged object at the time of rear folding is reduced. That is, packaging can be performed with a substantially constant tension from the start to the end of folding.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A stretch packaging machine according to a first embodiment of the present invention will be described below with reference to FIGS.
A stretch film wrapping machine 1 (hereinafter abbreviated as “wrapping machine”) shown in FIG. 1 includes a carry-in conveyor 4 for carrying a wrapped article 2 into a machine body 3 and a lifting and lowering of the wrapped article 2 carried into the machine body 3. The film 5 (not shown in FIG. 1; an elevator 5 to be moved and a package 2 raised by the elevator 5 are shown in FIG.
And a discharge conveyor 8 for discharging the packaged object 2 from the packaging unit 7 to the outside of the machine body 3.

As shown in FIG. 2, on the side of the packaging section 7, a film storage section 9 for storing the film 6, and a film holding mechanism for holding the leading end of the film 6 pulled out from the film storage section 9. And a cutter 11 for cutting the film 6 to a target length. The film 6 held by the film holding mechanism 10 is drawn into the wrapping portion 7 and is wrapped in the wrapping portion 7.
Transport mechanism 12A, 12 for transporting to a target position within
B is provided.

As shown in FIG. 3, the carry-in conveyor 4 has a plurality of conveying rollers 41, 41,... Which convey the articles 2 to the body 3 by being driven to rotate, and a positioning mechanism ( The centering device 42 and the articles 2 conveyed by the conveying rollers 41, 41 are stocked immediately before the positioning mechanism 42 and sent out to the positioning mechanism 42 by a signal from a control unit (not shown in FIG. 3). And a first stopper 43.

When the first stopper 43 is raised and protruded from the transport rollers 41, 41, the movement of the packaged object 2 in the direction of the machine body 3 is restricted. The packaged object 2 conveyed in the direction of the machine body 3 with the first stopper 43 lowered is positioned on the positioning mechanism 4.
The movement in the direction of the machine body 3 is temporarily restricted by the second stopper 44 driven up and down in the vicinity of 2, and during this movement restriction time, the left and right positioning plates 45 advanced from both sides in the transport direction,
45, it is accurately positioned, ie, centered, at a predetermined position in the transport width direction (a direction orthogonal to the transport direction) (see FIG. 4).

When the positioning of the package 2 in the transport width direction is completed, the left and right positioning plates 45, 45 are quickly separated from the package 2 and the second stopper 44 is lowered to move the package 2. Is restarted and carried into the body 3. In addition,
The positioning mechanism 42 detects the width W (the length in the direction perpendicular to the transport direction) of the package 2. In FIGS. 3 and 4, reference numeral 46 denotes a first detection sensor for detecting the unloading of the packaged articles 2 stocked by the first stopper 43;
Reference numeral 7 denotes a second detection sensor that detects the carry-out of the packaged articles 2 stocked by the second stopper 44.

FIG. 5 shows an internal conveyor 48 for transporting the packaged goods 2 carried into the machine body 3 by the carry-in conveyor 4 onto the elevator 5. The inner conveyor 48 extends from the end of the carry-in conveyor 4 on the downstream side in the conveying direction of the carry-in conveyor 4 to the vicinity of the elevator 5, and the goods 2 to which the carry-in goods 2 have been transferred from the carry-in conveyor 4. The elevator 5
Endless belt-shaped first transport belts 48a and 48 for transporting to the vicinity
, from the central portion in the extending direction of the first transport belts 48a, 48a, to the downstream side in the transport direction of the package 2 by the first transport belts 48a, 48a,. , And a second transport belt 48b that transports the packaged article 2 further downstream than the second transport belt 48b.

The first conveyor belts 48a, 48a,...
a and 48a are separated from each other. Are arranged in the gaps between the first conveyor belts 48a, 48a, and a plurality of second conveyor belts 48b are arranged in parallel. The adjacent second transport belts 48b are separated from each other with a gap slightly larger than the width of the first transport belt 48a.

The speed at which the package 2 is transported by the second transport belts 48b, 48b.
Are slightly slower than the..., So that the packaged object 2 delivered to the internal conveyor 48 is pressed against the positioning protrusion 48c protruding from the second conveyor belt 48b, and is brought into contact with the first and second conveyors. It is accurately positioned and conveyed on the belts 48a and 48b.

In FIG. 5, reference numeral 49a denotes a height detection sensor for detecting the height H of the package 2 conveyed by the internal conveyor 48, and 49b denotes a depth L (depth of the package 2). A depth dimension detection sensor for detecting the dimension in the transport direction by the internal conveyor 48. The dimension in the stretch direction of the film 6 in the packaging section 7 described later, for example, based on the cutoff time of transmitted light or the like. This is a positioning protrusion detection sensor for detecting.

The upper part of the elevator 5 is divided into a plurality of elevator heads 5b.
At the downstream end of the internal conveyor 48 in the transport direction,
Are located in gaps between the conveyor belts 48b, 48b...
Therefore, the elevator 5 is provided with each elevator head 5b.
Is raised and lowered without interfering with the second transport belt 48b. Since the upper surface of the elevator head 5b of the elevator 5 lowered for receiving the package 2 is located lower than the transport surface of the package 2 by the second transport belt 48b, the second transport belt 48b is The article to be packaged 2 can be transported onto the elevator 5.

The positioning projections 48c are provided on the second transport belt 48.
b, protruding at equal intervals, and a positioning protrusion detection sensor 49c.
When the positioning projection 48c is detected by the above, it is detected that another positioning projection 48c exists at the position of the elevator 5. At this time, the packaged object 2 positioned in contact with the positioning protrusion 48c positioned at the position of the elevator 5 is positioned immediately above the elevator 5 that has been lowered below the transport surface of the second transport belt 48b.

As shown in FIG. 6, the internal conveyor 48 includes
Initially, the packaged object 2 delivered from the conveyor 4 is
It is conveyed in the direction of the elevator 5 by the first conveying belt 48a, and then is conveyed by both conveying belts 48a, 48b in a region where the first and second conveying belts 48a, 48b are parallel to each other. The package 2 is conveyed only by the second conveyor belt 48b, and is sent onto the elevator head 5b lowered below the second conveyor belts 48b, 48b.

As shown in FIG. 7, when the article 3 is placed on the elevator 5, the elevator 5 is raised and the article 2 is placed on the elevator head 5b, as shown in FIG. Further, by continuing to raise the elevator 5, the article to be packaged 2 is fed into the upper packaging section 7 (not shown in FIG. 8).

As shown in FIG. 9, in the packaging section 7, the film transport mechanisms 12A and 12B (see FIG. 1) are disposed opposite to each other on both sides of the elevator ascending position 5a (the upper surface position of the elevator head 5b of the elevator 5 which has been raised to the upper limit). By this, the film 6 is pulled in and stretched horizontally before the elevator 5 rises. One of the film transfer mechanisms 12A and 12B is a film transfer mechanism
The other film transfer mechanism 12B is disposed on the pusher 76 side for discharging the sheet, and is opposed to the film transfer mechanism 12A via the elevator ascending position 5a.

In addition, both film transport mechanisms 12A, 12A
B both extend in a direction perpendicular to the discharge direction (arrow G in FIG. 9) of the packaged object 2 by the pusher 76 and are parallel to each other. Then, the film 6 drawn into the packaging unit 7 is transported by the film transport mechanisms 12A and 12A.
After the film is transported to the center of the packaging unit 7 by B (centering), the film transport mechanisms 12A and 12B are moved in the direction of separation by a pre-stretch mechanism (not shown), thereby being stretched in a preset state at a predetermined position. Is done.

Here, as shown in FIG. 10, when the elevator 5 is raised and the elevator head 5b reaches the elevator raised position 5a, the packaged object 2 on the elevator head 5b presses the film 6 up by pressing it. At this time, the film 6 is held by the clamp mechanisms of the film transport mechanisms 12A and 12B, which will be described later, does not come off and is slightly stretched by pushing up the packaged object 2, so that the film 6 is placed on the packaged object 2 with a certain tension. Will be covered.

Further, both film transport mechanisms 12A, 12B
Before the elevator head 5b reaches the elevator ascending position 5a, the film 6 is moved in the direction of being separated from each other by the pre-stretch mechanism as described above.
Is pre-stretched by an amount corresponding to the size of the package 2, so that even when the height of the package 2 is small, the film 6 abuts on the upper surface of the package 2 with a desired tension,
The generation of wrinkles and looseness is prevented. In addition, when the elevator 5 is raised and the film 6 is pushed upward by the packaged object 2, the two film transport mechanisms 12A and 12B approach each other to relax the tension of the film 6 (pre-stretch return). The occurrence of inconvenience such as tearing can be prevented.

Reference numeral 71 in FIGS. 9 and 10 denotes a holding plate, which is located above the film 6 stretched by the film transport mechanisms 12A and 12B, and which is lifted by the elevator 5 to the elevator ascending position 5a. The object 2 is pressed between the elevator 2 and the elevator head 5b with an urging force.

As shown in FIGS. 9 to 11, the stretch film packaging machine 1 is provided with a folding mechanism 70 for folding the film 6 between the elevator 5 and the article 2 to be packaged. The folding mechanism 70 includes left and right folding plates 72 and 73.
, A rear folding plate 74, and a front folding plate 75. Before the elevator 5 rises, the left and right folding plates 72 and 73 are separated from the elevator raising position 5a and are separated from each other.
When the film 6 is raised, it advances toward the elevator ascending position 5a, and enters the space between the elevator 5 and the package 2 with the film 6 engaged, that is, enters the lower side of the package 2 on the elevator head 5b. .

At this time, the elevator head 5b is tilted in the traveling direction of the left and right folding plates 72 and 73, so that the left and right folding plates 72 and 73 do not interfere with the elevator head 5b and the outer peripheral portion of the lower surface of the article 2 to be packaged. Get into it. Since the left and right folding plates 72 and 73 are located above the film 6 stretched by the film transport mechanisms 12A and 12B, the film 6 is moved from the side of the package 2 to the lower surface in the process of entering the lower surface of the package 2. Fold it to the side.

At this time, as the left and right folding plates 72 and 73 are moved, the clamping of the film 6 by the film transport mechanisms 12A and 12B is sequentially released from the position separated from the elevator ascending position 5a. It is folded under the article to be packaged 2 without any significant deformation or the like.

That is, as shown in FIG. 17, each of the film transport mechanisms 12A and 12B rotates a pair of upper and lower endless film transport belts 12b and 12c in opposite directions to each other.
The film 6 sandwiched between b and 12c is transported. At this time, the lower film transport belt 12
The part of c that faces the lower surface of the upper film transport belt 12b has a plurality of pressing plates (clamp mechanisms) that are driven up and down.
Due to the rise of 12d to 12h, the upper film transport belt 12b is pressed by the upper film transport belt 12b,
The film 6 is clamped and held between 12c so that it cannot be pulled out.

Also, even if the pressing plates 12d to 12h are lowered, the upper and lower film transport belts 12b and 12c are
Although there is a clamping force of the film 6, the clamping force at this time is lighter than when the pressing plates 12d to 12h are raised, and the film 6 can be pulled out from between the upper and lower film transport belts 12b and 12c. I have. Therefore, as shown in FIG. 11, when the film 6 is folded right and left by the left and right folding plates 72 and 73, first, the pressing plates 12 at both ends in the extending direction of each of the film transport mechanisms 12A and 12B.
d, 12h descend to release the clamp of the film 6,
Next, the pressing plates 12e and 12g near the center in the extending direction of each of the film transport mechanisms 12A and 12B are lowered to release the clamp of the film 6.

The lowering of the pressing plates 12d, 12e, 12g and 12h is performed not at the same time as when the left and right folding plates 72 and 73 advancing toward the elevator ascending position 5a come into contact with the film 6, but with a slight delay. . Thereby, the film 6
Can be folded from the side of the article to be packaged 2 to the lower surface thereof while applying an appropriate tension, and the occurrence of looseness and wrinkles can be prevented. The pressing plate 12f at the center in the extending direction of the film transport mechanisms 12A, 12B is kept raised, and the clamping of the film 6 is continued during the folding operation of the film 6 by the left and right folding plates 72, 73.

When the left and right folding plates 72 and 73 enter the lower side of the article 2 to be packaged, the elevator 5 is lowered. Thereby, the packaged object 2 is supported on the left and right folding plates 72 and 73,
In addition, since the film 6 under tension is pressed against the left and right folding plates 72, 73, the left and right folding plates 7
No positional deviation occurs on the positions 2 and 73. Further, the lowered elevator 5 shifts to a receiving operation of the next packaged object 2.

In a stretch wrapping machine having a conventional structure, it is common to wrap and wrap a film for an object to be wrapped supported on an elevator head, and the elevator is lowered until the fold of the film is completed. However, it was difficult to shorten the time required to shift to the operation of receiving the next packaged object. On the other hand, in the packaging machine 1, the packaged object 2 was
At the same time as being supported by 73, the elevator 5 can be moved down to the receiving operation of the next packaged object 2 so that the time required for the elevator 5 to feed the next packaged object 2 to the packaging section 7 can be shortened. Can be.

When the folding of the film 6 into the package 2 by the left and right folding plates 72 and 73 is completed, the folding plate 74 waiting on the pusher 76 side is moved to the elevator ascending position 5a.
(See FIG. 12), the film 6 held by the clamp is engaged with the film transfer mechanism 12A on the pusher 76 side, and the film 6 is folded from the side of the packaged object 2 to the lower surface side. The film transport mechanism 12A is moved in the direction of the elevator ascending position 5a in substantially synchronization with the movement of the rear folding plate 74, and the pressing plate 12f of the film transport mechanism 12A is lowered at an appropriate time during the rear folding process by the rear folding plate 74. To release the clamp of the film 6, the film 6 stretched between the film transport mechanism 12A and the packaged object 2 is folded into the packaged object 2 while maintaining an appropriate tension, and becomes loose. Generation of wrinkles and wrinkles is prevented.

As shown in FIG. 13, the left and right folding plates 72, 7
Numeral 3 is slidably mounted on a guide bar 77 extending along the film transport mechanisms 12A and 12B (a guide bar on the film transport mechanism 12B side is omitted) and driven by a drive mechanism (not shown). Thus, it moves smoothly while being guided by the guide bar 77. The guide bars 78, 78
(Direction of arrow G in FIG. 13; pusher 7 in FIG. 13)
6 extend along (not shown) and support the rear folding plate 74 so as to be slidable.

The rear folding plate 74 is in the form of a long plate, and forms the left and right folding plates 72 in the gap between the upper and lower plates (flat plates) 72a and 72b which are vertically arranged in parallel and the upper and lower forming the left and right folding plates 73. It is slidably sandwiched in the gap extending direction between the upper and lower plates (flat plates) 73a and 73b arranged in parallel. Rear folding plate 74
Of the film 6 by the left and right folding plates 72 and 73
Since the film 6 is folded in a state where the packaged object 2 is supported thereon, the film 6 folded to the lower surface side of the packaged object 2 moves while being in contact with the lower plates 72b and 73b of the left and right folding plates 72 and 73, It is folded so as to be gathered between the left and right folding plates 72 and 73.

Further, since the strength of the pair of left and right folding plates 72 and 73 composed of a pair of upper and lower plates is easy to secure, the upper plates 72a and 73a are made thinner so that the lower surface of the packaged object 2 and the rear folding plate are formed. 74 can be reduced in the vertical direction with respect to the upper surface of the rear folding plate 7.
4 ensures that the film 6 is folded.

On the other hand, the film transport mechanisms 12A, 12B
Are independently movable in a direction away from and approaching each other, that is, in a direction away from and approaching the elevator ascending position 5a. These film transport mechanisms 12A and 12B move in a direction approaching each other when the object to be packaged 2 comes into pressure contact with the film 6 by raising the elevator 5 and the tension of the film 6 increases. Thereby, the tension of the film 6 stretched between them is reduced, and it is possible to prevent the film 6 from being applied with excessive tension.

When the height detecting sensor 49a and the depth detecting sensor 49b detect that the packaged object 2 is larger than a predetermined size, as shown in FIG. In a state where the rear folding plate 74 advances toward the elevator ascending position 5a and the film 6 is engaged, the elevator 5 descends and the space area 50 formed between the elevator 5 and the packaged object 2, That is, when it enters the lower side of the packaged object 2 on the elevator head 5b, it moves in the same direction substantially in synchronization with the movement of the rear folding plate 74. That is, when the rear folding plate 74 advances toward the elevator ascending position 5a, the rear folding plate 74
Since the film 6 is engaged with both surfaces of the film 6, the length of the film 6 is twice as long as the amount of movement of the rear folding plate 74 at the end of the film 6.

Therefore, as shown in FIG. 15, the film transfer mechanism 12A moves at a speed twice as high as the speed of the rear folding plate 74 to reduce the tension applied to the film 6. Also, this film transport mechanism 1
When moving 2A, as described above, elevator 5
Is moved down to a predetermined position, for example, about 2/3 beyond the middle of the length of the packaged object 2 without being limited by the elevator 5. it can. As a result, the film 6 on the bottom surface side of the article to be packaged 2 has a certain overlap length, so that good-looking packaging can be performed.

Then, the film transport mechanism 12A releases the clamp holding on the end of the film 6 just before the folding by the rear folding plate 74 is completed, so that the film 6 is maintained in a proper tension while maintaining the proper tension. And the occurrence of loosening and wrinkles is prevented.

As shown in FIG. 16, after the folding of the film 6 by the rear folding plate 74 is completed, the pusher 76 is quickly driven to push the packaged objects 2 on the left and right folding plates 72, 73 to the discharge conveyor 8. And discharge. At this time, as shown in FIG. 1, the film 6 stretched between the front end in the discharge direction of the package 2 and the film transport mechanism 12 </ b> B abuts on the front folding plate 75, so that the lower surface of the package 2 And the entire packaged object 2 is wrapped by the film 6.

As shown in FIG. 16, the articles 2 to be discharged from the packaging section 7 are conveyed to a target position by a discharge conveyor 8. The discharge conveyor 8 has a heat generating function, and heat-fuses the film 6 folded from a plurality of directions to the lower surface side of the packaged object 2. Thereby, the packaging of the article to be packaged 2 by the packaging machine 1 is completed.

Next, an example of the structure of the film storage 9, the film holding mechanism 10, and the film transport mechanisms 12A and 12B will be described with reference to FIGS. In FIG. 17, the film storage unit 9 includes film rolls 9a and 9b around which the film 6 is wound, and a plurality of film guide rollers 9c, 9d, 9e, and 9f disposed between the film rolls 9a and 9b and the film holding mechanism 10. And a tension roller 9g for applying tension to the film 6 drawn out between the film rolls 9a and 9b and the film holding mechanism 10. In FIG. 17, the tension roller 9g is in contact with the film 6 passed between the film guide rollers 9c and 9d.
The configuration and arrangement position of g are not limited to the example shown in FIG. 17, and various configurations can be adopted.

The film holding mechanism 10 includes movable plates 10a and 10b which are disposed above and below the film 6 so as to face each other. As shown in FIGS. 18 (a), (b) and (c), the upper movable plate 10a Installed clamp roller 10
c and the clamp roller 10d attached to the lower movable plate 10b. Since both the clamp rollers 10c and 10d always sandwich the film 6, as shown in FIG.
When 10b is moved in the direction of the film transport mechanisms 12A and 12B from the vicinity of the film outlet from the film storage unit 9 (near the film guide roller 9f), the rotation of both clamp rollers 10c and 10d is regulated by the built-in one-way clutch. The film 6 moves together with the clamp rollers 10 c and 10 d while being clamped, and the film 6 is inserted into the film receiving port 12 a of the film transport mechanism 12.
Is sent (see FIG. 19).

As shown in FIG. 17, the movable plate 10
a and 10b are formed with a plurality of roller openings 10e, 10e... Each of the roller openings 10e is provided with a clamp roller 10c or 10d (not shown in FIG. 17). A pair of clamp rollers 10c, 1
0d clamps from above and below. In addition, a plurality of notch grooves 10 are provided at the distal ends of the movable plates 10a and 10b.
f is formed. Then, as shown in FIG. 19, when the movable plates 10a and 10b are inserted into the film receiving port 12a, each of the film transport mechanisms 1 is inserted through the notch grooves 10f formed on both sides in the width direction of the lower movable plate 10b.
The film 6 abuts on the lower film transport belt 12c of 2A, 12B. Further, as shown in FIG. 18B, when the film receiving port 12a is closed, the upper film transport belt 12b of the film transport mechanisms 12A and 12B is closed.
Is a notch groove 10f formed in the upper movable plate 10a.
The film 6 is interposed between the upper and lower film transport belts 12b and 12c.

After the film receiving port 12a is closed and the film 6 is held in each of the film transport mechanisms 12A and 12B, as shown in FIG.
b is pulled back to the vicinity of the film guide roller 9f, and the film 6 is moved into the wrapping section 7 by the film transport mechanisms 12A and 12B (in the direction away from the film holding mechanism 10).
Be drawn in. At this time, as shown in FIG. 18C, since both clamp rollers 10c and 10d roll with respect to the film 6, drawing in the film 6 by the film transport mechanisms 12A and 12B affects pulling back of the film holding mechanism 10. Not done smoothly. In addition, tension is applied to the film 6 by the rotational resistance of the clamp rollers 10c and 10d, so that wrinkling and loosening of the film 6 can be prevented. Here, since the cutter 6 is driven to cut the film 6 while the tension is acting on the film 6, it can be cut accurately at the target position (see FIG. 21).

As shown in FIG. 19, the upper film transport belt 12b near the film receiving port 12a of each of the film transport mechanisms 12A and 12B is wound around the elevating roller 12i. , Is advanced toward the lower film transport belt 12c, and the film receiving port 12a is opened and closed. Here, when the film 6 is fed into the film receiving port 12a by the film holding mechanism 10 and the elevating roller 12i is lowered as shown in FIG. 20, the upper and lower film transport belts 12b and 12c
The film 6 is interposed therebetween, and thereafter, the film 6 is conveyed to the elevator ascending position 5a by the rotational driving of the film conveyance belts 12b and 12c (FIG. 22).

FIG. 23 shows an example of a control unit for controlling the operation of the packaging machine 1. In FIG. 23, this CPU 80
Includes a ROM 81, a RAM 82, an operation unit 83, and a display unit 8.
4. The I / O port 85 is connected. I / O port 8
5 includes a motor M1 drive circuit 91 for controlling a motor M1 for driving the elevator 5, a motor M2 drive circuit 92 for controlling a film transfer mechanism drive motor M2, and a pre-stretch motor M for driving the film transfer mechanism 12B.
And M4 drive circuit 93a for controlling M3 and M4 respectively
And motor M4 drive circuit 93b, film transport mechanism 1
A motor M5 drive circuit 94a and a motor M6 drive circuit 94b for controlling the pre-stretch motors M5 and M6 respectively for driving the 2A, a motor M7 drive circuit 95 for controlling the motor M7 for driving the left and right folding plates 72 and 73, a rear folding plate A motor M8 drive circuit 96 for controlling the motor M8 for driving the pusher 76 and a motor M9 drive circuit 97 for controlling the motor M9 for driving the pusher 76 are connected to the I / O port 85.
, Each of the motors M1 to M9 is driven. The motors M2 to M9 are pulse motors (stepping motors).

A rotary encoder 86 is connected to an elevator cam shaft (not shown) for the elevator 5 driven by the motor M1 for the elevator 5, and the pulses generated by the rotary encoder 86 are counted. The control of each operation unit is performed based on the count value of the above.

The sensors S 1, S 2, S 3 are connected to the I / O port 85 via a sensor drive circuit 87.
From the detection signals of these sensors S1, S2, S3, the size data of the packaged object 2 is input. That is, the sensor S1
From the width W of the package 2 and from the sensor S2 the package 2
And the height H of the packaged object 2 is input from the sensor S3. The sensor S1 corresponds to the positioning mechanism 42, and the sensor S2 corresponds to the depth dimension detection sensor 49b. The sensor S3 corresponds to the height detection sensor 49a.

FIG. 24 is a side view of the fold, the back fold,
Time indicating the operation timing of front folding (extrusion of the packaged object 2 by the pusher 76), rear stretching (movement of the film transport mechanism 12A), front stretching (movement of the film transport mechanism 12B), film feed, and elevation of the elevator 5. It is a table. In FIG. 24, the count value is represented by a rotary encoder 86 (FIG. 23).
), And the rotation angle is the rotation angle of the lifting cam.

In the packaging machine 1, the count value is "5".
Before reaching "0", that is, in the first half of the packaging cycle, the film transfer mechanisms 12A and 12B draw out and cut a predetermined length of film, and center the cut predetermined length film (transfer to a predetermined position). Is performed. Thereafter, pre-stretching before and after the film is performed.

The pre-stretching of the film is performed by independently moving the film transfer mechanisms 12A and 12B by a predetermined amount in the direction in which they are separated in the width direction. The moving amount and moving speed of the rear film transfer mechanism 12A are set to be larger and faster than the moving amount and moving speed of the front film transfer mechanism 12B. Also,
In parallel with this, loading and positioning of the packaged object 2 on the elevator head 5b are performed.

Then, in the latter half of the packaging cycle (the count value is “50 to 100”), the package
, The left and right folding plates 72 and 73, the rear folding plate 74, and the discharge pusher 76. The elevator 5 is lowered during the packaging.

After the elevator 5 has been lifted, the film transport mechanism 1 starts moving immediately before reaching the elevator lift position 5a.
Loosening of the stretch of the film 6 by the 2A and 12B (movement of the film transport mechanisms 12A and 12B in the direction of the elevator ascending position 5a) is started. Therefore, the film 6 stretched and stretched between the two film transport mechanisms 12A and 12B is pressed forward by the packaged object 2 on the ascending elevator 5 and is pushed upward. The side stretch will be relaxed. Thereby, it is possible to prevent inconvenience such as breakage due to a large load acting on the film 6 when the elevator 5 is raised. However, at this time, the tension acting on the film 6 is hardly changed.

Immediately before the elevator 5 reaches the elevator ascending position 5a and stops, the driving of the left and right folding plates 72 and 73 and the rear folding plate 74 is started. As a result, the left and right folding plates 72 and 73 and the rear folding plate 74 start moving in the direction of the elevator ascending position 5a, but the loading of the article to be packaged 2 into the packaging machine 1 is in the vertically long state, that is, the width W is the depth. The packaging is actually started in the direction larger than the dimension L, and the packaging object 2 carried into the packaging machine 1 is actually positioned on the elevator 5 based on the front end side (folding plate and film). Are engaged so that the film is folded into the bottom of the packaged object 2) by the left and right folding plates 72, 7
3 is performed first, followed by rear folding by the rear folding plate 74.

Then, in the process of right and left folding by the left and right folding plates 72 and 73, as described above, the film transport mechanism 12
The pressing plates 12d and 12h on both sides of A and 12B are lowered to release the clamp of the film 6, and then the pressing plates 12e and 12g near the center are lowered to release the clamping of the film 6.

The elevator 5 is lowered immediately before or immediately after the end of the left / right folding by the left / right folding plates 72 and 73. Then, after that (after the elevator 5 is lowered), the actual packaging by the rear folding plate 74 is started. At this time, the packaged object 2 is placed on the upper plate 72 of the left and right folding plates 72, 73.
No inconvenience occurs because they are placed by a and 73a.

At the time of rear folding by the rear folding plate 74, when the height dimension detecting sensor 49a and the depth dimension detecting sensor 49b detect that the packaged object 2 is larger than a predetermined size, the rear folding is performed. The rear film transport mechanism 12A has a slight time difference in synchronization with the movement of the plate 74.
Is moved in the direction of the front film transport mechanism 12B. At this time, the rear film transport mechanism 12A clamps the film 6 with the central pressing plate 12f.

As described above, since the elevator 5 has already been lowered, the movement of the film transport mechanism 12A is performed when the elevator 5 is at the raised position 5a as shown in FIGS. It is possible to enter an immovable area, that is, into the moving space area 50 of the elevator 5. The moving speed of the rear film transfer mechanism 12 </ b> A is set to be about twice the moving speed of the rear folding plate 74. Film transport mechanism 12A
Is moved to the predetermined position, the pressing plate 12f is lowered to release the clamp to the film 6.

The position where the film transfer mechanism 12A releases the clamp of the film 6 is determined by the position of the film transfer mechanism 12A.
A is a position inside the position where the film 6 is fed while sandwiching the end of the film 6, that is, a position shifted to the center line side of the film 6 to be fed.

As described above, the left and right folding plates 72 and 73 are formed in a two-layer structure including the upper and lower plates 72a, 72b, 73a and 73b, respectively. Can be placed, and the elevator 5 is lowered at the time of the backward folding by the rear folding plate 74, and when the packaged object 2 is at least a predetermined size or more, at the time of the backward folding by the rear folding plate 74,
The rear transfer means, which is the rear film clamping means, is moved into the moving space area 50 of the elevator 5 almost in synchronism with the rear folding plate 74 and then the clamp of the film 6 is released. A sufficient margin for folding the film 6 can be secured.

Further, since the moving speed of the film transfer mechanism 12A is about twice as high as the moving speed of the rear folding plate 74, the tension of the film 6 applied to the packaged object 2 at the time of rear folding is maintained at an appropriate level. can do.

FIG. 25 shows an article 2 to be packaged by the packaging machine 1.
2 shows the packaging process. First, in a first step S1, a packaged object 2 (commodity) is carried into the carry-in conveyor 4, and the carried-in package 2 is loaded into the carry-in conveyor 4 or the internal conveyor 4.
By 8, it is transported onto the elevator 5 that is moving down and waiting.

In the second step S2, the internal conveyor 4
In step 8 of transporting the package 2, the size of the package 2 is detected. The size of the package 2 to be detected includes
A width dimension W (a dimension in a direction orthogonal to a stretching direction of the film 6 in the packaging section 7; a dimension in a direction orthogonal to a transport direction by the internal conveyor 48); and a depth dimension L (a dimension in a stretching direction of the film 6 in the packaging section 7). Dimensions: Internal conveyor 48
In the transport direction) and a height dimension H. These detected size data are used for determining the packaging control data in the third step S3.

The packaging control data determined in the third step S 3 includes the cut length of the film 6, the pre-stretch amount of the film 6 pulled into the packaging section 7, the pre-stretch return timing, the pre-stretch return amount, the film Clamp release timing of the film 6 in the transfer mechanisms 12A and 12B (down timing of the pressing plates 12d to 12h),
And whether or not there is synchronous movement with respect to the rear folding plate 74 of the film transport mechanism 12A.

In the fourth step S4, corresponding to the size data of the packaged object 2 detected in the second step S2,
The packaging of the article to be packaged 2 is executed. After the packaging is completed, the process returns to the first step S1, and the first to fourth steps S1 to S4 are similarly performed for the packaging of the next packaged object 2.

In the packaging machine of the present embodiment, the left and right folding plates 7
Since the packages 2 and 73 support the package 2 from below, the elevator 5 is lowered, and the operation can be shifted to the receiving operation of the next package 2 until the next package 2 is sent to the packaging unit 7 by the elevator 5. Time can be shortened. Further, when the height dimension detection sensor 49a and the depth dimension detection sensor 49b detect that the packaged object 2 is equal to or larger than a predetermined size, the film transport mechanism 12A moves and excessive tension is applied to the film 6. It is possible to flexibly cope with everything from a small packaged object 2 to a large packaged object 2, for example, it is possible to prevent problems such as tearing of the film 6 beforehand.

As described above, when the film transport mechanism 12A moves in accordance with the folding operation of the rear folding plate 74, since the elevator 5 has been lowered in advance,
It is possible to move to a predetermined position without being limited to the elevator, for example, beyond the middle of the packaged object 2, and to make the folding allowance of the film 6 long enough to secure a certain overlap length.

Then, the film transport mechanisms 12A, 12B
However, since it also has a film clamping function, it is not necessary to provide a separate film clamping means. Further, since the film transport mechanisms 12A and 12B move in a direction approaching each other in synchronization with the elevation of the elevator 5, it is possible to prevent an excessive tension from being applied to the film 6. Further, since the film transfer mechanism 12A moves at twice the speed of the movement of the rear folding plate 74, the tension of the film 6 can be maintained at an appropriate level even when folding backward.

In the above-described embodiment, a configuration is adopted in which a small film to a large product are packed with a narrow film by pre-stretching according to the size of the product. However, the present invention is not limited to this. If the object to be packaged is raised and lowered and the film is pre-stretched according to the size of the product, a plurality of film rolls with different widths are arranged, and the width of the film used according to the size of the product is automatically set A configuration that allows selection may be used. Further, the synchronous movement of the film transport mechanism with the rear folding plate is performed when the size of the packaged object is equal to or larger than a predetermined size, but is not limited to this, regardless of the size of the packaged object. It may be configured to move synchronously.

Although the film is pre-stretched in the direction (width direction) perpendicular to the transport direction by the film transport mechanism, film clamping means is provided at both ends in the longitudinal direction of the film, and the film is moved in four directions. A prestretching configuration may be used. Furthermore, although the pressing plate constituting the film clamping means is configured to be divided into five pieces, the number may be five or more or five or less, and in this case, as described above, at both ends in the longitudinal direction of the film. When the film clamping means is provided, the pressing plate may not be divided.

On the other hand, in the present embodiment, the film transport mechanism is configured to serve both as a means for transporting the film to the stretched position and a means for pre-stretching the film. However, the present invention is not limited to this. Film feeding means for feeding the film by holding the leading end of the film,
A configuration in which the film clamping means and the pre-stretch means are separately provided may be employed.

Further, in the present invention, the elevator 5 can be lowered when the left and right folding is completed by making the left and right folding plates have a two-layer structure. However, the configuration of the left and right folding plates is limited to this embodiment. The configuration is not limited to a specific configuration as long as the configuration is such that the packaged object is placed on the upper plate of the left and right folding plates. For example, JP-A-61-1
It is also possible to employ the configuration described in JP-A-42109.

[0093]

As described above, according to the first aspect of the present invention, the left and right folding plates for folding the left and right ends of the film into the bottom of the packaged article are formed in a two-layer structure having upper and lower flat plates, respectively. Also, by arranging the rear folding plate between the upper and lower flat plates so as to be movable in the front-rear direction, when the left and right folding is performed, the packaged object is placed on the upper flat plate of the left and right folding plates. Thus, the elevator is lowered at the time of folding the rear end of the film by the rear folding plate.

When the size of the package is at least equal to or greater than a predetermined value, the rear clamp mechanism is moved in conjunction with the folding operation of the rear folding plate to lower the elevator.
And moving it into the moving space area of the elevator formed between the elevator and the packaged object, and then moving
The pinching of the film is released in the space area . That is, in the conventional stretch wrapping machine in which the left and right folding plates are constituted by a single flat plate, when folding the rear end portion of the film by the rear folding plate, the object to be packaged must be placed by the elevator. The rear clamp mechanism is moved in conjunction with the rear folding plate to a region where the rear clamp mechanism cannot be moved, and the clamp of the film is released in the second half of the rear folding or immediately before the end.

For this reason, there is no need to release the rear clamp at the initial stage of the backward folding as in the prior art,
Even if the size of the packaged object is equal to or larger than a predetermined value and the amount of front and rear pre-stretch is large, a sufficient margin for folding the rear end of the film can be obtained. Therefore, even a large-sized packaged object that cannot be packaged conventionally can be packaged reliably and with good appearance.

Also, since the rear clamp mechanism is moved in conjunction with the rear folding plate to a region where it was not possible in the past, the deformation force applied to the packaged object by the tension of the film at the time of rear folding can be appropriately reduced. Can be. For example,
If the rear clamp mechanism is not moved, the film having a length approximately twice as long as the rear folding plate is moved, but the moving distance of the rear clamping mechanism is larger than the moving distance of the rear folding plate. Is set to about twice, the stretching amount of the film at the time of the backward folding becomes substantially zero, and the deformation force hardly acts on the packaged object at the time of the backward folding.

On the other hand, by setting the amount of movement of the rear clamp mechanism to an appropriate value of about twice or less, the folded object can be folded while maintaining an appropriate tension at the time of folding backward. Becomes Therefore, it is possible to pack an object to be packaged with a good appearance, even if it is an object to be packaged, such as a soft tray, which needs to minimize the tension applied during packaging.

According to the second aspect of the present invention, since the film is pre-stretched using the clamp mechanism, it is not necessary to separately provide the clamp mechanism and the pre-stretch means. Therefore, the cost can be reduced as much as the number of component parts is reduced, and the structure of the stretch wrapping machine is simplified, so that the stretch wrapping machine can be made small and lightweight.

According to a third aspect of the present invention, the clamp mechanism comprises:
Since the film transfer means is also used, there is no need to provide the film transfer means separately from the clamp mechanism. Therefore, the cost can be reduced due to the reduced number of components, the structure of the stretch wrapping machine can be simplified, the stretch wrapping machine can be made compact and lightweight, and at the time when the transfer of the film is completed, the film is clamped by the clamp mechanism. Since the front and rear end portions are sandwiched, the processing speed of the stretch packaging machine is improved accordingly.

According to the fourth aspect of the present invention, the tension adjustment at the time of the rear folding can be performed immediately before the end of the rear folding by moving the rear clamping mechanism to the inside (the front clamping mechanism side) from the position where the film is being transferred. It is possible to do until. Conventionally, in a packaging machine that performs pre-stretching, tension (deformation force) applied to a packaged object by loosening the pre-stretch when the elevator is lifted or folded backward.
There is also a thing that relaxes, but this is just to pre-stretch, that is, to restore the stretched amount, narrowing the gap between the front and rear clamp mechanism to less than the width of the film before pre-stretching It was not a thing, and I could not do it because I had an elevator at the time of turning back.

In the present invention, since the movement of the rear clamp mechanism is not limited by the elevator, the tension adjustment at the time of the rear folding can be performed by moving the film to the inside (the front clamp mechanism side) from the position where the film is being transferred. This can be performed until immediately before the end of the folding.

According to a fifth aspect of the present invention, the rear clamping mechanism has a plurality of film clamping means, and some of these clamping means are suitable for folding the left and right end portions of the film by the left and right folding plates. By releasing at an appropriate timing, the tension applied to the packaged object at the time of folding right and left can be adjusted. Therefore, there is no need to separately provide the left and right clamp mechanisms.

According to the sixth aspect of the present invention, since the rear clamp mechanism is driven substantially in synchronization with the driving of the rear folding plate, a change in tension applied to the packaged object at the time of rear folding is reduced. In other words, packaging can be performed with a substantially constant tension from the start to the end of folding, and packaging can be performed with a more attractive appearance than before.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of the present invention, and is an overall front view showing a stretch film packaging machine.

FIG. 2 is a cross-sectional view showing the vicinity of a packaging section of the stretch film packaging machine of FIG.

FIG. 3 is a perspective view showing the vicinity of a carry-in conveyor of the stretch film packaging machine of FIG. 1;

FIG. 4 is a perspective view showing the operation of the carry-in conveyor of FIG. 3;

FIG. 5 is a perspective view showing an internal conveyor provided in the stretch film packaging machine of FIG.

6 is a view showing the operation of the internal conveyor of FIG. 5, and is a perspective view showing an initial stage of transport of an article to be packaged.

FIG. 7 is a perspective view showing the internal conveyor of FIG. 5 and showing the loading of an article to be packaged onto an elevator.

FIG. 8 is a perspective view showing an elevator provided in the stretch film packaging machine of FIG.

FIG. 9 is a perspective view showing the drawing of a film into a packaging unit provided in the stretch film packaging machine of FIG. 1;

FIG. 10 is a perspective view showing the loading of an article to be packaged into a packaging section when the elevator is lifted.

FIG. 11 is a perspective view showing left and right folding of a film into an article to be packaged.

FIG. 12 is a perspective view showing the back folding of the film into the packaged object.

FIG. 13 is a perspective view showing left and right folding plates, a rear folding plate, and a front folding plate provided in the packaging unit.

FIG. 14 is a front view in which a rear folding plate moves in a state where a film is engaged in a gap between left and right folding plates.

FIG. 15 is a front view in which the film transport mechanism moves in synchronization with the movement of the rear folding plate.

FIG. 16 is a perspective view showing front folding of a film into a packaged object.

FIG. 17 is a perspective view showing a film storage section and a film holding mechanism provided in the stretch film packaging machine of FIG. 1;

FIG. 18 is a side view showing a film holding mechanism,
(A) shows the initial state, (b) shows the drawing of the film into the film receiving port, and (c) shows the drawing back after drawing the film.

19 is a perspective view showing a state where the film is pulled out by the film holding mechanism of FIG.

FIG. 20 is a perspective view showing the drawing of the film drawn out to the film receiving port into the packaging part.

FIG. 21 is a perspective view showing a cut of the film drawn into the packaging unit.

FIG. 22 is a perspective view showing a state where the drawing of the film is completed.

FIG. 23 is a block diagram showing a configuration of a control unit provided in the stretch film packaging machine of FIG.

FIG. 24 is a view showing a time table of the operation of the stretch film packaging machine of FIG. 1;

FIG. 25 is a flowchart showing the operation of the stretch film packaging machine of FIG. 1;

FIG. 26 is a front view showing an example of a conventional packaging machine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Stretch film wrapping machine (stretch wrapping machine) 2 Packaged material 5 Elevator 6 Film 12A Film transfer mechanism 12d-12h Pressing plate (clamping mechanism) 50 Moving space area 72, 73 Left and right folding plates 72a, 72b, 73a, 73b Upper and lower plates (Flat plate) 74 Rear folding plate

Continuation of the front page (56) References JP-A-61-142109 (JP, A) JP-A-8-15009 (JP, A) JP-A 9-12004 (JP, A) JP-A-6-286713 (JP) JP-A-9-169307 (JP, A) JP-A-58-12106 (JP, U) JP-A-2-69802 (JP, U) JP-A-2-90203 (JP, U) (58) Field surveyed (Int.Cl. ⁷ , DB name) B65B 11/06-11/48 B65B 49/08

Claims (6)

(57) [Claims] 1. A film cut to a predetermined length is stretched over an elevator by sandwiching the front and rear ends of the film by a clamp mechanism, and a packaged object placed on the elevator is placed on the film with respect to the film. After covering the upper surface of the package with the film by pushing up from below, the left and right and rear end portions of the film are folded into the bottom of the package by left and right folding plates and rear folding plates, respectively. In a stretch wrapping machine that folds the front end of the film while discharging the package, the left and right folding plates are configured in a two-layer structure having upper and lower plates, and between the upper and lower plates. The rear folding plate is disposed so as to be movable in the front-rear direction, and at least a rear clamping mechanism of the clamping mechanisms is configured to be movable in the front-rear direction. When the elevator is lowered during the period from when the folding operation of the plate is started to when the rear folding plate is folded, and when packaging an object to be packaged having at least a predetermined size or more, the folding operation of the rear folding plate is performed. The rear clamp mechanism is operated in conjunction with the elevator,
Wherein the said elevator is moved up to the movement space area of the elevator, which is formed between the packaged articles, then before
A stretch wrapping machine configured to release the holding of the film in the moving space area . 2. The stretch packaging machine according to claim 1, wherein the clamp mechanism clamps the front and rear ends of the film cut to a predetermined length and moves the film back and forth according to the size of the article to be packaged. A stretch packaging machine characterized in that it also serves as a pre-stretch means for pre-stretching in the direction. 3. The stretch packaging machine according to claim 1, wherein the clamp mechanism holds the front and rear ends of the film cut to a predetermined length and transfers the film to the upper part of the elevator. A stretch wrapping machine, which also serves as a transfer means. 4. The stretch wrapping machine according to claim 3, wherein the rear clamp mechanism is movable from a position where the film is being transported to a front clamp mechanism side in relation to a folding operation of the rear folding plate. A stretch wrapping machine characterized in that: 5. The stretch wrapping machine according to claim 1, wherein the rear clamping mechanism has a plurality of film clamping means, and at least one of the film clamping means is provided on the rear folding plate. A stretch wrapping machine, wherein the film is released after being moved to the moving space area of the elevator in conjunction with the folding operation. 6. The stretch wrapping machine according to claim 1, wherein the rear clamp mechanism is driven substantially in synchronization with the driving of the rear folding plate.