JP2932971B2 - Stretch film packaging 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 stretch film wrapping machine, and more particularly to a stretch film covering a wrapped object, in which a widthwise end portion of the stretch film is sandwiched by a conveyor belt. The present invention relates to a packaging machine for pre-stretching and packaging in the width direction.

[0002]

2. Description of the Related Art In general, when a film drawn from a film roll is cut into a predetermined length in a stretch film wrapping machine of this type, a predetermined amount of the film is drawn so that the cut edge (cut edge) becomes a clean straight line, and the film is conveyed. Was stopped and the cutter was activated. In particular, by changing the amount of pre-stretching in the width direction of the film according to the size of the object to be packaged, a packaging machine that packages objects of various sizes with one narrow film roll can cut the film. If the edge is not a clean straight line, the film will tear during pre-stretching when the pre-stretch amount is large.Therefore, stop the transport belt when cutting the film, restart the transport belt after cutting the film, and then cut the film. The length of the film was transported to the packaging section.

[0003]

Therefore, when the cut film of a predetermined length is conveyed to the packaging section and centering is performed at a predetermined position, the film conveying device is restarted, and the conveying speed increases. Until the completion of the centering, extra time is required, and as a result, the packaging capacity per unit time is reduced.

Accordingly, the applicant of the present application has filed a patent application for a packaging machine in which a film is drawn out to a predetermined length, then the film is cut while moving the cutter at the same speed as the film, and the film is moved to a predetermined position without stopping. Hei 6-32821
No. 1 proposes. However, the above-mentioned packaging machine requires a mechanism for moving the cutter and a mechanism for grasping the rear end of the cut film, and has a problem that the structure of the entire apparatus is complicated and the cost is high.

[0005] The present invention has been made in view of the above-mentioned problems of the prior art.
It is an object of the present invention to provide a stretch film packaging machine capable of shortening a film supply time and improving a packaging processing capacity.

[0006]

The technical means taken by the present invention to achieve the above object is to draw out a film from a film roll, and wrap the film by holding both side edges in the width direction of the film with a conveyor belt. Transported to the department and stretched,
In a stretch film packaging machine in which an object to be packaged is pushed up from an underside of the film by an elevator mechanism, the upper surface of the object to be packaged is covered with a film, and the end of the film is folded into the bottom surface of the object to be packaged, A cutter for cutting the film, and a film transfer means for transferring and transferring the leading end of the film upstream of the cutter to the transport belt at a position upstream of the cutter, and when the film has been transported by a predetermined amount, disposes the cutter. Cutter control means for operating; and transport belt control means for continuously operating the transport belt after receiving the film by the film transfer means and transporting the film to a predetermined position in the packaging unit.

A feed roller for feeding a film from a film roll may be provided upstream of the film transfer means, and a feed roller control means for stopping the feed roller simultaneously with the operation of the cutter may be provided.

Further, the film is prestretched and stretched in the width direction in accordance with the dimensions of the object to be packaged, and the object to be packaged is pushed up from below the film by an elevator mechanism so that the upper surface of the object to be packaged is covered with the film. In a stretch film packaging machine that performs packaging using a narrow film by pre-stretching a film in the width direction according to the dimensions of the packaged object before covering up and pushing up the packaged object, an upstream side of the transport belt A cutter for cutting the film, and a film transfer means for transferring and transferring the leading end of the film upstream of the cutter to the transport belt at a position upstream of the cutter, and when the film has been transported by a predetermined amount, disposes the cutter. Cutter control means to be actuated, and the film is received by the film transfer means, and then the film is transported to a predetermined position in the packaging unit. Transport belt control means for operating the transport belt, further provided with a determination means for determining whether the dimensional value of the packaged object is greater than a predetermined value, the output of the determination means to control the transport belt control means Control, when cutting the film conveyed by a predetermined amount, the output of the determination means is YE
In the case of S, the transport belt is stopped to cut the film, and when the output of the determination means is NO, the film is cut without stopping the transport belt. The detecting means for detecting the size of the article to be packaged is placed in the middle of placing the article to be packaged on the mounting table a and transporting it to the elevator 1 by the conveyor B.

[0009]

According to the first aspect of the present invention, when the film is pulled out from the film roll and cut at a predetermined length, the film is cut without stopping the driving of the conveyor belt that draws and conveys the film. The film cut to a predetermined length can be transported to a predetermined position in the packaging unit. Therefore, the film can be quickly stretched onto the packaging section, and the time required for one packaging can be reduced. According to the second aspect, at the time of cutting the film, the feeding roller for feeding the film from the film roll is stopped at the same time as the operation of the cutter, so that the cutting of the film is performed instantaneously while the feeding is stopped. , Easy to cut and clean,
The leading end position of the next film is constant. Further, according to the third aspect, since the drive and stop of the transport belt at the time of cutting the film are controlled to be switched depending on the size of the article to be packaged, stable pre-stretching is performed while increasing the processing capacity.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. The stretch film packaging machine shown in FIG. 1 and FIG.
A product placing section a for placing the article to be packaged is provided on the side of the machine frame A, and the article to be packaged placed on the article placing section a is transported by the conveyor B to the elevator 1 provided inside the machine frame A. . Around the conveyor B, sensors for measuring the width, depth, and height of the packaged object are provided. A packaging portion b is provided above the elevator 1, and a side of the packaging portion b holds a film roll disposition portion 2 and a leading end portion of a film 3 'unwound from a film roll 3 set in the disposition portion 2. A film transfer means C is provided, and a conveyor belt D for nipping and drawing out the leading end of the film held by the film transfer means C and conveying the film to the packaging section b is arranged close to the front end of the film transfer means C. ,
In addition, a cutter E that cuts the drawn film held between the film transfer means C and the conveyor belt D to a predetermined length is disposed. Also, the conveyor belt D
Above the left and right folding plates 4, 4 'and the rear folding plate 5,
A discharge pusher 6 is disposed above the rear folding plate 5.

Therefore, the article to be packaged placed on the elevator 1 is pushed up against the film 3 'spread on the packaging section b by raising the elevator, and the end of the film in the stretched state is After folding on the bottom surface of the package by the left and right folding plates 4 and 4 'and the rear folding plate 5,
While the object to be packaged is horizontally moved by the discharge pusher 6 toward the discharge portion in front of the machine frame A, the front end of the film 3 'is folded to fold the film.

The film transfer means C includes a film 3 ′ of the film roll 3 set in the film roll placement section 2.
As shown in FIG. 3, the endless belt 7 is disposed under the film and is disposed in parallel with a gap corresponding to the film width of the film roll 3 in the front-rear direction. A film receiving plate 8 erected and fixed
A holding plate 9 for holding a film supported on the surface of the film receiving plate 8 by sandwiching the film between the film receiving plate 8 and a holding roller 10 attached to the holding plate 9 is provided. Protective cover that can be freely opened and closed with respect to A
11, is vertically slidably supported inside, and is engaged with a film receiving plate 8 erected and fixed to an endless belt 7 and slides up and down together, and is sandwiched between the film receiving plate 8 and the holding plate 9. It is configured such that the leading end of the film 3 ′ to be attached and held can be transferred to the transport belt D. The holding roller 10 attached to the holding plate 9 has its outer surface fitted and projected from a through hole 12 formed in the holding plate 9 into a through hole 17 formed in the film receiving plate 8 to hold the film. The film is meandered along the peripheral surface of the film 10 to reliably hold the film, and the holding roller 10 is configured to be rotatable only in the direction in which the film is pulled out.

Further, the endless belt 7 is wound around a pulley fixed to a rotating shaft of a motor 13, a pulley 15 coaxial with a feeding roller 14, and a driven pulley 16, and is driven by the motor 13. The endless belt 7 is configured to move up and down (rotate) along the moving direction of the film.
The drive of the feed roller 14 for drawing out and supplying the film of the film roll 3 to the above-mentioned film transfer means C is connected to a drive system of a conveyor belt D, which will be described later, via a pulley. The drive and stop of the feeding roller are controlled separately from the film transfer means C by using a tag, and are controlled so as to stop simultaneously with the operation of the cutter for cutting the film. In addition, the film transfer means C is a film roll placement unit 2
It is also optional that one or both of the transfer means can be moved in the width direction according to the film width so as to correspond to the film roll to be set in the apparatus.

The transport belt D is a pair of upper and lower endless elastic belts 18 and 18 'for sandwiching a lateral end of the film in the width direction.
And a clamp plate 19 for pressing the lower elastic belt 18 ′ against the upper elastic belt 18, and a top plate on the starting end side of the lower elastic belt 18 ′, and the tip side is opened and closed. It is composed of a holding belt 20 which can be freely arranged, and these are arranged back and forth with the packing part b interposed therebetween, and the interval is the same as the pair of front and rear holding means constituting the film transfer means C described above. The pair of front and rear components are supported by mounting frames 21, 21 ', and the mounting frames 21, 21' are two guides arranged at right angles to the lower side of the mounting frames 21, 21 '. The mounting frame 21 'on which one of the conveyor belts D1 is mounted is fixed, and the mounting frame 21 on which the other conveyor belt D2 is mounted is supported by the rods 22 and 22' via connecting members 23 and 23 '. The movable belt D2 is configured to be movable along the movable belt 22 and 22 '. The movable belt D2 is connected to a distance extending means (not shown) so that the distance between the movable belt D2 and the fixed belt D1 can be adjusted. Have been.

A pair of upper and lower endless elastic belts 18 and 18 'constituting the above-mentioned transport belt are driven and rotated in the same direction so as to pinch and transport the film. Chain sprocket fixed to the shaft of the drive roller and the chain sprocket fixed to the shaft of the drive roller around which the elastic belt 18 'is wound. The power transmission is performed by winding the chain between the two, and the upper elastic belt 18 is also rotated. Further, the clamp plate 19 for pressing the lower elastic belt 18 'against the upper elastic belt 18 is not limited to the illustrated three-division but may be divided into four or more, and such a clamp plate can be uniformly transported and expanded. As shown in the figure, the films are arranged symmetrically with respect to the center of the film.

The cutter E, which cuts the film drawn by the operation of the conveyor belt D and the feed roller 14 to a predetermined length, appears and retracts substantially at right angles to the film 3 'by a control means constituted by an electromagnetic solenoid 25. The cutting of the film 3 ′ is performed by controlling the energization of the electromagnetic solenoid 25.

Next, the operation of cutting and transporting the film in the packaging machine described above includes (A) an operation of stopping the transport belt to cut the film, and (B) an operation of driving and rotating the transport belt to rotate the film. FIG. 5 shows the cutting operation.
And a time chart of FIG. still,
Switching between (A) and (B) is performed by the film roll placement unit 2
It is determined by the width of the film roll set in, and the depth dimension (vertical width) of the packaged material to be provided for packaging. For example, when the film roll width is 250 mm, the depth dimension of the packaged product is 150 mm or more. (A), when the depth dimension of the packaged object is less than 150 mm, the operation is switched to (B).
Further, each control of driving / stopping a feeding roller for feeding a film, operating / stopping a cutter, moving up / down a film transfer means C, and driving / stopping a conveyor belt D is performed based on a rotation angle of a cam 26 for driving an elevator. When the cam makes one rotation, one cycle of packaging is performed. The rotation angle of the cam is detected by counting output pulses from the rotary encoder 27 attached to the cam shaft and detecting the count value.

(A) will be described. (See FIG. 5) (I) When the object to be packaged is placed on the product placement part a and the weighing is completed, the main motor starts rotating. The cam is rotated by the main motor, and the elevator moves up and down at the timing shown by one rotation of the cam. When it is determined that the depth dimension of the package to be waited is equal to or more than the predetermined value, the transport belt is stopped to set the mode for cutting the film, and the main motor is set to the low speed mode. At this time, the time chart is 0
Start from ゜. (II) Immediately after the conveyor B is driven, the articles to be packaged which have been placed last time and are waiting before the elevator 1 are placed on the elevator 1. (III) At substantially the same time when the conveyor B is driven, the film receiving plate 8 and the holding plate 9 constituting the film transfer means C are integrally lowered. (IV) Next, the conveyor belt D is driven, and the feed roller 14 is driven and rotated with a slight delay to draw out a film having a length optimal for the previous packaging of the article to be packaged from the film roll 3 and simultaneously stop. Incidentally, the length of the film pulled out is detected by measuring the amount of movement of the belt by providing an optical counter on the rotating shaft of the conveyor belt. (V) Next, the electromagnetic solenoid 25 for moving the cutter E to the film side is turned on, the cutter operates, and the stopped film 3 'is cut so as to have a clean straight cutting edge.

(VI) After cutting the film, the electromagnetic solenoid is turned off, the cutter E is returned to the original position, and the motor of the conveyor belt D is restarted so that the cut film is positioned at the center of the wrapping portion b. Then, the conveyor belt D is moved by a predetermined amount and stopped. (VII) The film expansion is started simultaneously with the stop of the transport belt D, and the expansion is completed before the elevator 1 rises. During this time, the rear folding plate and the left and right folding plates are in the most opened state. Then, the loading of the packaged article is also completed, and the packaged article weighed this time detects the “width” in the early stage of loading, and the “depth dimension” in the later stage, and when the depth dimension is detected to be 150 mm or more, the packaged article is removed. Waiting in front of elevator 1. (VIII) At the time when the elevator 1 starts to ascend and reaches the top, the closing movement of the rear folding plate and the left and right folding plates is started, and the movable conveyor belt D2 of the conveyor belt D, which has been expanding the film, is closed. Start to move. By moving the movable conveyor belt D2 in the closing direction to weaken the film expansion, the tensile strength of the film is reduced.

(IX) When the folding of the end of the film is completed, the pressing belt provided on the upper part of the starting end of the conveying belt D
The start end side of 20 rotates upward, and then the film transfer means C is raised to the conveyor belt D side. At this time, the feeding roller 14
Is in a free rotation state, and since the holding roller provided in the film transfer means C holds the film, the film 3 'is pulled out by the raising of the film transfer means C,
The leading end of the film is the lower elastic belt of the conveyor belt D
It is located between 18 'and the presser belt 20. This makes it possible to pull out the film by the next conveyance belt D, and one packaging cycle is completed.

As for (B), during the above-mentioned process, the depth dimension of the packaged article which has been previously loaded and is waiting is 150 mm.
The operation in the case where it is detected to be less than mm may be considered as an operation that is continuous to the above (IX). (See FIG. 6) (X) When the next weighing of the packaged object is completed, it is determined whether the depth dimension of the packaged object waiting is less than 150 mm,
Since the result of the determination is “YES”, the mode is set to the mode in which the film is cut while the transport belt D is driven and rotated, and the main motor is started in the high-speed mode. (XI) Same as (II) in (A). (XII) Same as (III) in (A).

(XIII) The conveyor belt D is rotated first, and then the feed roller 14 is driven and rotated to operate the cutter E immediately before the film of the optimum length is pulled out of the film roll 3 from the film roll 3 on standby. And cut the film to the correct length. When the delivery roller 14 is pulled out by a predetermined length, the delivery roller 18 is turned off the clutch of the transmission pulley 18 and the brake is turned on so that the delivery roller 14 is not linked with the transport belt D.
14 is suddenly stopped. (XIV) After cutting the film, the electromagnetic solenoid is turned off, and the cutter E is returned to the original position. (XV) The conveyor belt D performs the continuous operation from (XIII) until the cut film reaches the centering position. Subsequent steps are the same as (A) and (VII).

Comparing the above (A) and (B), the centering end time of the film is about 1.
0 seconds, about 0.7 seconds for (B), and about 0.7 seconds for (B).
It turns out that it is about 3 seconds earlier. Therefore, the subsequent operation can be started earlier by that much, and as a result, the packaging capacity can be increased. In addition, it is more preferable that the switching between the modes (A) and (B) is performed not only by determining the depth dimension of the packaged object but also by determining the height dimension from the viewpoint of the finished packaging. In the type in which the film is pulled out from the rear of the packaging machine to the front, the width of the packaged object should be determined. The dimension data may not be detected and obtained, but may be set in advance for each product and called.
Further, the driving of the feed roller 14 described above is not limited to the configuration linked to the drive system of the transport belt D shown in the embodiment, and is operated by a drive system independent of the drive system of the transport belt D. You may. Further, the film transfer means is not limited to the above-described embodiment, but may be a form in which the leading end of the film is gripped and transferred. Further, although the present embodiment has been described for a type in which one film roll is mounted, a packaging machine of a type in which a plurality of film rolls having different film widths are mounted can be applied to claims 1 and 2. In addition, the present invention can be applied to claim 3 as long as the pre-stretch amount is changed depending on the dimensions of the article to be packaged.

[0024]

According to the first aspect of the present invention, the stretch film packaging machine can cut the film while rotating the transport belt without stopping the transport belt. Therefore, the transport belt is stopped and restarted. In this case, there is no rise time, and the cut film can be quickly stretched to a predetermined position of the packaging section, and the packaging processing speed can be increased. In the case of the configuration shown in claim 2, since the film can be instantly stopped from being fed by the feeding roller when cutting the film,
Cutting is stable, and the next film tip position can be kept constant. Further, in the case of the configuration shown in claim 3, the film is not uniformly operated for all the objects to be packaged, and the film is cut while rotating the transport belt for the objects to be packaged with a small amount of film expansion. Therefore, the packaging capacity can be increased without any problem.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view schematically showing a stretch film packaging machine according to the present invention.

FIG. 2 is a vertical sectional front view of FIG.

FIG. 3 is an enlarged view showing a film transfer section from a film transfer means to a conveyor belt.

FIG. 4 is an enlarged view showing a state in which the film transfer means is raised and transfers the film to the conveyor belt.

FIG. 5 is a time chart when a film is cut by stopping a conveyance belt.

FIG. 6 is a time chart in a case where a film is cut while a conveyor belt is rotated.

[Explanation of symbols]

 C: Film transfer means D: Conveying belt E: Cutter 1: Elevator 3: Film roll 14: Feeding roller

Claims (3)

(57) [Claims] 1. A film is pulled out from a film roll, and both side edges of the film in the width direction are conveyed to a packaging portion while being held by a conveyor belt, and stretched, and an object to be packaged is lifted from below the film by an elevator mechanism. In a stretch film packaging machine that pushes up and covers the upper surface of the packaged object with a film, and folds the end of the film into the bottom surface of the packaged object, a cutter that cuts the film on the upstream side of the conveyor belt, and a position upstream of the cutter. A film transfer means for transferring and transferring the leading end of the film upstream of the cutter to the transport belt, and a cutter control means for operating the cutter when the film is transported by a predetermined amount; and The transport belt that continuously operates the transport belt until the film is transported to the predetermined position in the packaging section after receiving the A stretch film packaging machine, comprising: 2. A feed roller for feeding a film from a film roll upstream of the film transfer means, and a feed roller control means for stopping the feed roller simultaneously with the operation of the cutter. The stretch film packaging machine according to claim 1, wherein 3. A film is pulled out from a film roll, and both side edges in the width direction of the film are conveyed to a packaging portion while being held by a conveyor belt and stretched. The packaging is performed using a narrow film by pushing up and covering the upper surface of the packaged object with the film and pre-stretching the film in the width direction according to the dimensions of the packaged object before pushing up the packaged object. In the stretch film packaging machine, a cutter for cutting a film on the upstream side of the conveyor belt, and a film transfer means for transferring the front end of the film on the upstream side of the cutter to the conveyor belt at a position upstream of the cutter, And cutter control means for operating the cutter when the film is conveyed by a predetermined amount; and Transport belt control means for operating the transport belt until the film is transported to a predetermined position of the packaging section after receipt, and further provided with determination means for determining whether or not the dimensional value of the article to be packaged is greater than a predetermined value. When the output of the determination means controls the transport belt control means to cut the film conveyed by a predetermined amount, if the output of the determination means is YES, the transport belt is stopped to cut the film, and the determination means A stretch film packaging machine characterized by cutting a film without stopping the conveyor belt when the output of the film is NO.