JPH0439125Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a stretch film packaging machine, and more specifically, it is equipped with a film transfer mechanism that feeds and transfers the film by pinching both ends of the film at a plurality of points. Related to stretch film wrapping machine.

(Prior Art) Conventional stretch film packaging machines include a film transport mechanism that transports a film cut to a predetermined length to a wrapping position and stretches it, and a film transport mechanism that transports a film cut to a predetermined length to a wrapping position and stretches the film. Some devices include an elevator device that pushes up the packaged item from the lower part, and a film folding device that weaves the packaged item from the front, back, left and right to the bottom at the top of the film transport mechanism.

Further, as the film transport mechanism provided in the stretch film packaging machine, there are those disclosed in Japanese Patent Application Laid-open Nos. 50-53198, 53-89591, and 57-68309. In these film transfer devices, the film gripping portion of the grip is flat, and a large gripping force is required to securely grip the film, resulting in a complicated mechanism.

The present applicant has devised a film transport device as shown in FIG. 6, which does not require the above-mentioned complicated mechanism.

Endless chains 6 on both sides of the film transport path
c, and an endless elastic belt 6d is provided around the outer periphery of each chain 6c.
A plurality of mounting plates 7a are provided at predetermined intervals on the outer surface of the mounting plate 7a with bolts 7b.

A grip 7 is provided on each mounting plate 7a so as to be swingable about a shaft 7c. The grip 7 is lever-shaped with a shaft 7a at its center, and a round recess 7d is formed at the portion where it contacts the belt 6d.

In the figure, s represents a solenoid, and one end of the grip 7 is surrounded by upper and lower guide plates 22a and 22b, and the grip 7 is opened and closed by turning on and off the solenoid s.

Although the above-mentioned film transport mechanism has a large force for holding the film even if the force for pressing the grip is small and has a simple structure, it has the following disadvantages.

Since the stretch film A is bitten into the tip 7h of the grip 7, it is difficult to remove the stretch film A even if the grip 7 is opened as shown in FIG. Therefore, wrinkles, kinks, etc. are likely to occur in the packaged state, and there is a risk that the packaging quality will deteriorate.

(Purpose of the invention) This invention was devised to solve the above-mentioned problems.The purpose of this invention is to provide a large gripping force to the film even if the force to press the grip is small, a simple structure, and a simple structure for the film. To provide a stretch film packaging machine equipped with a film transfer mechanism that allows the film to be pulled out easily and does not cause damage to packaging quality.

(Structure of the invention) The stretch film wrapping machine of the invention includes a film transport mechanism that transports a film cut to a predetermined length to a wrapping position and stretches it, and a lower part that moves toward the film stretched at the wrapping position. In a stretch film packaging machine, the film transporting mechanism is connected to a film transporting path, and includes an elevator device for lifting up the object to be packaged, and a film folding device for folding the end of the film into the bottom of the object at the top of the film transporting mechanism. A pair of rotatable endless chains provided on both sides of the chain, an elastic belt provided around the outer periphery of the chain and rotating together with the chain, and an outer side of each chain as a fulcrum, with one end facing the elastic belt in a predetermined position. It is composed of a plurality of grips that swing in a range of angles and have recesses formed at the tips of the swinging ends to fit with the elastic belt, and both ends of the film are sandwiched between the grips and the elastic belt. By driving the chain in this state, the film is fed out and transferred, and the direction of the tensile force applied to the film held between the grip and the elastic belt is changed by pushing up the packaged object by the elevator device. A direction changing roller is placed near the inner side of at least one of the chains, parallel to the elastic belt, with the lower surface of the roller above the position where the film is held between the grip and the elastic belt, and spaced apart from the elastic belt. It is placed under the lower surface of the tip of the grip when the grip is in a closed position.

(Function) As described above, the direction changing roller is placed near the inner side of at least one of each chain in parallel with the elastic belt, and the lower surface of this roller is above the grip and the elastic belt at the position where the film is held between the elastic body and the elastic belt. Since the tip of the grip is located at the lower side of the lower surface of the grip when it is separated from the belt, when the item to be packaged is pushed up by the elevator device toward the film stretched on the wrapping device, the fitting recess of the grip and the elastic belt are disposed. The edge of the film between the two ends receives a horizontal or downward tensile force.

Therefore, when the end of the film is folded into the bottom of the object to be packaged using the film folding device, when the film is released and the grip is separated from the elastic belt, the fitting recess of the grip and the film held between the elastic belts are removed. The side edges can be easily separated from the grip by being pulled horizontally or downwardly as described above.

(Embodiment) A first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

10 in the figure is a machine frame, and this machine frame 10 is constructed into a substantially rectangular parallelepiped, with the lower side in FIG. 2 being the front side 10b and the upper side being the back side 10c. A carry-in port 10a is opened approximately in the center of this front surface 10b, and a carry-in conveyor 11 is disposed from this side of the carry-in port 10a to inside the machine frame 10.

The carry-in conveyor 11 is composed of a pusher conveyor 12 and a belt conveyor 14, and conveys the packaged items to a predetermined position on an elevator head 13 disposed at the discharge end side of the pusher conveyor 12.

As shown in FIG. 2, the pusher conveyor 12 is
The chain 12 is connected between a pair of sprockets 12a, 12a provided in front of the loading port 10a and a pair of sprockets 12'a, 12'a provided inside the machine frame 10.
b, 12b, and the chain 12b, 12b
A pusher 12c, 12c is provided at a predetermined position, respectively, and one article to be packaged is carried in each time the chains 12b, 12b rotate half a rotation. The pusher conveyor 12 pushes the packaged items placed on the conveyance surface 12d with pushers 12c and conveys them.
A roller 14a of the belt conveyor 14 is provided nearby so as to freely rotate.

The belt conveyor 14 has a roller 14b freely rotatable at the rear of the elevator head 13 (upper part in FIG. 2) corresponding to the roller 14a, and six belts 14c, 14c are provided between the rollers 14a, 14b.
...is strung up. Belt conveyor 14
is for transporting the packaged articles brought in by the pusher conveyor 12 to the rear end side of the elevator head 13.

The elevator head 13 is installed on a head mounting base (not shown) supported by a pair of arms (not shown) that swing up and down, and holds the packaged items carried in by the carry-in conveyor 11 in a predetermined position. It is pushed up and raised to the packaging position 9. Therefore, the lower end position of the elevator head 13 is set at approximately the same height as the conveying surface 12d of the carry-in conveyor 11, and the upper end position is set at approximately the same level as the packaging position 9, that is, the horizontal folding plates 17, 17 and the front folding plate 16, which will be described later. The position will be set to

It should be noted that, like the conventional packaging machine, the apparatus of this embodiment pushes up a stretch film to cover the upper surface with the stretch film while the item to be packaged is being pushed up to the packaging device 9 by the elevator head 13.

The elevator head 13 and the head mounting base are constructed in a slit shape as shown in FIG. 2, so that when the elevator head 13 is moved up and down, the belts 14c, 14c, . 13b so as not to come into contact with it.

The elevator head 13 is made up of a plurality of small blocks 13c, 13d, 13e..., and each of the small blocks 13c, 13d, 13e... is provided to be able to rise and fall freely in response to a force applied from a predetermined direction.
It is biased upright by a coil spring (not shown) or the like. The small block 13c is tilted by a force from the right side in FIG. 2, the small block 13d is tilted by a force from the left side in FIG. 2, and the small block 13e is tilted by a force from the bottom side in FIG. 2. To enable folding work of stretch film to be carried out without any hindrance.

In addition, 15 in FIG. 2 is a positioning plate provided at the rear of the elevator head 13.
The object to be packaged brought in in step 4 is positioned with reference to the rear end.

Around the packaging position 9, as shown in FIG.
A pair of horizontal folding plates 17, 17', a front folding plate 16, and a rear folding roller 18 are provided, and these constitute an opening through which the packaged items pushed up by the elevator head 13 pass. .

The horizontal folding plates 17, 17' are used to perform horizontal folding in the left-right direction, and are each provided so as to be slidable in the left-right direction in FIG. 2, and are configured to slide in conjunction with each other in opposite directions.

The front folding plate 16 performs forward folding after the horizontal folding is completed, and is provided so as to be slidable in the vertical direction in FIG. 2, and is driven independently of the horizontal folding plates 17, 17'. An unloading pusher 31 is disposed above the front folding plate 16.

The carry-out pusher 31 transfers the packaged items, which have undergone the front folding and the horizontal folding, to the rear folding roller 18.
During this movement, the back-folding roller 18 performs back-folding to complete the packaging. The packaged items that have been wrapped are placed on the heat belt 19.
The bottom folded portion is heat welded while being transported at the .

The above is a description of the packaging mechanism in the packaging machine of the embodiment, focusing on the transfer of the items to be packaged.

Next, the film supply section and the advance device will be explained.

In the figure, reference numerals 20 and 20' indicate support rollers, and a similar support roller (not shown) is provided below them.
It is configured to support two types of stretch film rolls (not shown) each having a different width and to be able to use them selectively.

The film fed out from the film roll is wound around the support roller 20' on the right side, passes through the drawn end detection roller 40, and then passes through the upper and lower feeding belts 27,
It is inserted between 27', 28, and 28'. The belt 2
At 7, 27', 28, 28', the forward feeding device 60,
60' is constructed.

Next, to briefly explain the feeding and transport of the stretch film, the belts 27, 27', 28,
The film inserted between the belts 27 and 28'
It is fed out by the rotational movement of 27', 28, and 28'. The film that has been fed out to the delivery end of the belts 27, 27', 28, 28' is then separated by grip groups 7, 7', which will be described later, and rubber belts 6d,
6'd, the film is fed out to a length necessary for packaging, and the cutter device 29 cuts the film to the required length.

The cut film is transferred to a predetermined position above the elevator head 13, that is, until the center of the film coincides with the center of the elevator head 13, and then stopped and placed in a standby state.

A film grip device consisting of grip groups 7, 7' and rubber belts 6d, 6'd is arranged at a height between the packaging position 9 and the lower end position of the elevator head 13 so as to sandwich the packaging position 9 as shown in FIG. They are arranged facing each other.

As shown in FIG. 3, a pair of adjuster screws 1 and 2 are rotatably provided in the machine frame 10 from the front side 10b to the back side 10c, and the rear side 10c of each adjuster screw 1 and 2 is rotatably provided. Hypoid gears 1c and 2c are provided at the side ends, respectively.

Further, a rotating shaft 3 is disposed along the back surface 10c of the machine frame 10, and the hypoid gears 1c,
Hypoid gears (not shown) meshing with 2c are each fixed.

A handle 3c is provided at the right end of the rotating shaft 3 on the outside of the machine frame 10, and by rotating the handle 3c, the adjusting screws 1 and 2 can be rotated via the rotating shaft 3. .

The adjusting screw 1 has threaded portions 1a, 1b,
The adjusting screw 2 is formed with threaded portions 2a and 2b, respectively, and the threaded portions 1a and 2b shown in the upper part of FIG.
2a has a close pitch, and the lower threaded portions 1b and 2b have reverse threads and a coarse pitch. As a result, as will be described later, when the distance between the chain conveyors 6 and 6' is changed in accordance with the width of the stretch film used, the amount of variation in the chain conveyor 6 is smaller than that in the chain conveyor 6'.

This is because the direction in which the packaged items are carried out is taken into consideration.

That is, in this embodiment, after completing the left and right horizontal folding and front folding of the packaged item, when carrying out the packaged item in the opposite direction to the carry-in direction, the package is folded backward to complete the packaging. This is because drastic changes in the amount cause twitching and wrinkles, which is undesirable. Further, the threaded portions 1a and 1b have a generally coarser pitch than the threaded portions 2a and 2b.

In the figure, D is the distance between the centers of the packaging position 9, d is the distance on the adjusting screw 2 side, and C is the film stretch rate (hereinafter referred to as pre-stretch degree).
Then, the pre-stretch degree C at the center of the packaging position 9 is expressed by the following equation.

C=(D-d)/d In order to keep this pre-stretch degree C constant regardless of the film width,
It is necessary to change the widening angle of the chain conveyors 6, 6', and the threaded portions 1a, 1b, 2a, 2b
The pitch is set to meet these requirements.

The apparatus of this embodiment is configured such that the degree of pre-stretching C at the center of the packaging position 9 is approximately 0.05 (5%).

Each screw portion 1 of the adjusting screw 1, 2
A, 1b, 2a, 2b are equipped with adjusting blocks 4a, 4b, 5 with nuts that fit with them.
a and 5b are arranged. Pass it to the adjusting blocks 4a, 5a on the back side 10c and connect it to the chain conveyor
At the same time, the chain conveyor 6' is passed to the adjusting blocks 4b, 5b on the front side 10b
Place.

The chain conveyors 6, 6' have a substantially symmetrical structure in the vertical direction in FIG. 3, and are disposed in a divergent shape with respect to the film transport direction (from right to left in FIG. 3). The chain conveyor 6 will be explained in detail below.

A mounting board 54 is provided between the adjusting blocks 4a and 5a so as to be rotatable and movable within a small range in the front and rear directions, thereby making it possible to change the diverging angle of the chain conveyor 6.

A sprocket (not shown) is rotatably disposed at each end of the mounting board 54, and an endless chain 6c is stretched between the sprockets.

An endless rubber belt 6d with a circular cross section is provided around the outer periphery of the chain 6c. The rear surface 10 of the chain 6c as shown in detail in FIG.
A plurality of approximately U-shaped mounting plates 7a, 7a, . . . are provided at predetermined intervals on the c-side side surface.

The mounting plates 7a, 7a, .
..., and each mounting plate 7a has a shaft 7c.
The grip 7 is rotatably attached via the .

The grip 7 is molded from a molding material such as ABS resin, and has a lever-like structure that swings around a mounting portion 7e provided at its center. A semicircular recess 7d that fits into the rubber belt 6d is formed on the rubber belt 6d side of the grip 7, and
The other end acts as an operating piece 7f when the grip 7 is opened or closed.

As shown in FIG. 1, a support plate 55 is attached to the upper part of the mounting board 54 over a predetermined area with screws 56, and a protrusion 55a integrally formed on this support plate 55 is connected to a chain. 6c to guide and support it, and the other protrusion 55b engages with the engagement hook 7g integrally formed on the mounting plate 7a to guide and support the mounting plate 7a. There is.

Next, a mechanism for opening and closing the grip 7 will be explained. Note that the state in which the grip 7 and the rubber belt 6d are in contact with each other as shown by the solid line in FIG.
The state in which d and d are separated is called an open state.

The opening/closing mechanism of the grip 7 includes a fixed guide member 8a,
8b and movable guide members 21, 22, and 23.

Fixed guide members 8a and 8b are disposed near the outside of the sprocket on the film supply section side and are configured to sandwich the side edges of the film. The grip 7 moves under the chain 6c by balance in a substantially closed state and reaches the fixed guide member 8a. The fixed guide member 8a is used to turn the grip 7 over the chain 6c in an open state, and its lower portion has a smooth slope so as to engage with and guide the operating piece 7f of the grip 7. Formed in a planar shape.

As shown in FIG. 3, three movable guide members 21, 22, and 23 on the left side, center, and right side are arranged near the outside of the chain conveyor 6. Each movable guide member 21, 22, 23 has a substantially similar structure, and the movable guide member 22 in the center will be explained.

As shown in FIG. 1, the movable guide member 22 includes an upper pressing plate 22a and a lower pressing plate 22b.
The upper pressing plate 22a is constructed to be substantially continuous with the lower pressing plates 21b and 23b, and the upper pressing plate 22a is slightly shorter than the lower pressing plate 22b.

The lower side of the upper pressing plate 22a is fixed to the side of the lower pressing plate 22b by spot welding or the like, and the operating piece 7f of the grip 7 is located in the space 22c formed by the upper pressing plate 22a and the lower pressing plate 22b. You will be guided.

The lower pressing plate 22b is provided with biasing means (not shown) such as springs below near both ends thereof, and is constantly biased upward.

As shown in FIG. 1, the lower pressing plate 22b is formed into a U-shape in cross section, and this side portion is formed by the pin 22e.
is connected to the tip of the operating rod 22f of the solenoid S. The solenoid S is arranged approximately at the center of the lower pressing plate 22b and is screwed to the side plate 58.

When the solenoid S is not energized, the operating rod 22f is in a slidable state, and the lower pressing plate 22b is urged upward by the urging means as shown by the solid line in FIG. Therefore, the operating piece 7f of the grip 7 is pressed upward by the lower pressing plate 22b.

Therefore, the recess 7d of the grip 7 is connected to the rubber belt 6a.
It fits firmly into the side edge of the film.

When the solenoid S is excited, the operating rod 22f is attracted by the solenoid S and moves downward, as shown by the dashed line in FIG. 1, and the upper pressing plate 22a moves downward.

The operating piece 7f in the space 22c is the upper pressing plate 22a.
The grip 7 is pushed down and moved downward, and the grip 7 becomes open.

As shown in FIG.
At each left and right end of 2 and 23, there is a mounting plate 4 from the side plate 58.
5, 45 are provided protrudingly, and the mounting plates 45, 45 are provided so as to protrude.
A roller R is provided across the tip of the roller.

This roller R is a roller for changing the direction of the tensile force applied to the film held between the rubber belt 6a and the grip 7 when the item to be packaged is pushed up to the packaging position 9 by the elevator head 13. , as shown in FIG. 1, the belt 6d is placed in a range 43 that is higher than the film clamping position 41 and lower than the upper end position 42 where the tip of the grip 7 is opened.
It is located close to.

The roller R is a movable guide member 21, 22, 2
3 to open the grip 7, the film A bit into the tip of the grip 7 is pulled almost horizontally or downwardly from the tip of the grip 7, as shown in FIG. The concave portion 7d of No. 7 becomes easy to peel off.

Therefore, when the film A is folded by the folding plate, the film A can be easily pulled out.

Next, a second embodiment will be explained with reference to FIG.

A substantially L-shaped shaft stopper plate 4 is provided on the upper surface of the side plate 58.
Fix 4,44. At the tip of the shaft stopper plates 44, 44, there are roller mounting plates 45, 45 having a substantially gate-shaped side surface.
One end of the shaft is connected to the shaft stop plate 4 by the shafts 46, 46.
4 and 44, and a roller R is rotatably attached to the other end. Yotsute Roller R
Roller mounting plates 45, 45 are attached to opposite ends of the rollers, and are attached to the upper surface of the side plate 58 by means of shaft stopper plates 44, 44, respectively.

Further, a spring mounting plate 47 having a substantially crank-shaped cross section is provided on the outer edge side of the side plate 58, and the mounting plate 47 and one end of the roller mounting plate 45 are connected by a spring 48, and the roller R is urged downward. Spring mounting plate 47
A nut 49 is fixed to the nut 49, and a screw 3 is attached to the nut
2 are fitted together to form a stopper for the roller mounting plate 45.

Note that the configuration other than the above is the same as that of the first embodiment, and a description thereof will be omitted.

In this embodiment, when the film is folded into the lower side of the tray by the folding plate 16, the film is pulled up and lifted so as to rotate the roller R counterclockwise. When the grip 7 is released, the roller R is urged clockwise, and this urging force causes the roller R to push the film downward, so that the grip 7
The film will be easier to separate from the tip.

Note that this roller R is at least connected to the heat belt 19.
It is effective to arrange it at the tip of the grip of the side chain conveyor 6. This is because, after the front folding is completed, when the unpacked item is discharged by the unloading pusher 31 and the rear folding is performed by the rear folding roller 18, the film held between the grips 7 on the chain conveyor 6 side is approximately This is because the film is pulled in the vertical direction, so even if the grip 7 is released, it is very difficult for the film to separate from the grip 7.

(Effect) Since the present application is structured as described above,
When the film is folded into the bottom of the packaged object using the folding device, when the grip is separated from the elastic belt and the film is released, the edge of the film that was held between the fitting recess of the grip and the elastic belt becomes horizontal. Alternatively, since the film is pulled downward, the film that has bitten into the recessed portion of the grip can be easily peeled off, thereby allowing the film to be smoothly removed from the grip and packaging with a good finish.

In this way, the intended purpose is achieved.

[Brief explanation of the drawing]

FIG. 1 is an enlarged side sectional view showing the main parts of the film transport mechanism according to the first embodiment of the present invention, FIG. 2 is a plan view of the packaging machine according to the first embodiment, and FIG. 3 is the main parts of FIG. 2. 4 is an enlarged side view showing the main parts of the second embodiment, FIG. 5 is a diagram of the principle of operation of the first and second embodiments, and FIG. 6 is a diagram of the principle of operation of the preceding example. . In the figure, 6...Chain conveyor, 6c...Chain, 6d...Elastic belt, 7...Grip,
7d...Recessed portion, 41...Film clamping position, 13
...Elevator head, 17, 17'...Horizontal folding plate, 16...Front folding plate, 42...Upper end position of grip tip, 43...Roller position, A...Stretch film, R...Roller.

Claims (1)

[Scope of utility model registration request] A film transport mechanism that transports a film cut to a predetermined length to a wrapping position and stretches it; an elevator device that pushes up the packaged object from below toward the film stretched at the packaging position; and the film transport mechanism. A stretch film packaging machine comprising a film folding device for folding the end of the film into the bottom of the packaged object at the upper part, the film transport mechanism comprising a pair of rotatable endless chains provided on both sides of a film transport path; , an elastic belt provided around the outer periphery of the chain and rotating together with the chain, and an elastic belt that swings within a predetermined angle range with one end facing the elastic belt using the outside of each chain as a fulcrum, and the elastic member at the tip of the swing. The film is composed of a plurality of grips each having a recessed portion that fits into the belt, and the film is fed out and transferred by driving the chain with both ends of the film being held between the grips and the elastic belt. At the same time, a direction changing roller is installed inside at least one of the chains to change the direction of the tensile force applied to the film held between the grip and the elastic belt when the packaged object is pushed up by the elevator device. Nearby, parallel to the elastic belt, the lower surface of the roller is located above the position where the film is held between the grip and the elastic belt, and below the lower surface of the tip of the grip that is spaced apart from the elastic belt. A stretch film wrapping machine characterized by the following: