JP3301374B2 - 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, such as fresh food, with a stretch film, and more particularly to a technique for cutting out a film used for packaging from a film roll.

[0002]

2. Description of the Related Art An operation of pulling out a film from a film roll set in a stretch packaging machine and cutting the film at a predetermined length is performed by pressing a cutter having a saw-toothed edge against a film surface stretched under a predetermined tension. It is done by that. This means that if tension is not applied to the film, the film is not cut instantaneously even if the cutter is hit, and is not cut until the cutter hits the film surface deeply. It is very rough and easy to tear.
The leading end of the film on the film roll side is held by holding means provided with a notch that partially exposes the leading end of the film so that the conveying means can grip the next film withdrawal. The film was transported to the packaging section by a transport means, stretched, and used for packaging.

[0003]

However, the pulling force (tension) of the film is lost due to the cutting of the film, and the leading end of the film on the film roll side returns to the roll side, and the film cannot be held by the holding means. There has been a rare problem that the film is retracted to the back and the leading end of the film cannot be grasped by the conveying means.

[0004] The present invention has been made in view of the above-mentioned problems of the prior art.
When cutting the film drawn from the film roll,
An object of the present invention is to provide a stretch wrapping machine provided with a film holding means capable of reliably pulling out a film for the next wrapping without the leading end of the film on the film roll being drawn into the film roll.

[0005]

In order to achieve the above object, the present invention provides a technical means in which a film roll side is moved by a predetermined distance by holding a film leading end on a film roll side.
This allows the transport means to receive the leading edge of the film,
In operation, the film is pulled out to a predetermined length and cut, and the cut film of a predetermined length is conveyed by a conveying means and stretched over a packaging portion. In a stretch wrapping machine in which an upper surface is covered with a film and an end of the film is folded into the bottom of the object to be packaged, a film end on a film roll side is held near a front end of the film holding portion almost simultaneously with cutting of a predetermined length of film. In addition, a pinching means for releasing the pinching of the leading end of the film is provided at a timing when the packaging by the cut and separated film is almost completed.

The holding means holds the film tip on the film roll side near the tip of the film holding portion almost simultaneously with the cutting of the film of a predetermined length, and until just before the next film is pulled out for the next packaged object. A holding means for performing the holding may be used. Further, in the holding means, one of the holding members constituting the holding means may be connected to a cutter or a cutter receiver which approaches the cutter at the time of cutting.
The cutting of the film may be performed while the film is pulled out for a predetermined length and stopped, or may be performed while the film is being drawn. Further, the timing for opening the holding means is not required to detect the end of the packaging or the draw-out of the film, and as a result, the timing may be substantially the same in the ordinary packaging.

According to the first aspect of the present invention, since the film tip on the film roll side is held by the holding means at the same time as the film is cut, and the film is held until the packaging of the cut film is almost completed, the film contracts. The time is reduced, and the return of the leading end of the film in the film holding unit can be reduced. According to the second aspect of the present invention, since the leading end of the film is held until the timing immediately before the drawing of the film for packaging the next packaged object, the return of the leading end of the film in the holding portion can be reduced.

Further, according to the third aspect of the present invention, when one of the holding members of the holding means for holding the leading end of the film is connected to the cutter or the cutter receiver, the timing of interlocking with the cutting operation can be ensured with a simple structure. It is possible to obtain.
According to the fourth aspect of the present invention, by cutting the film while it is being pulled out, the tension of the film at the time of cutting can be increased, whereby the cut edge can be made clear and the film can be quickly conveyed to the packaging section. Becomes possible.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 show an overall view of a stretch film wrapping machine. A machine frame A has a conveyor 1 on the side and an elevator 2 inside. A packaging part b is provided above the elevator 2, and a film roll placement part 3 and a film roll 4 set in the placement part 3 are provided beside the packaging part b.
A film holding portion 5 for holding a leading end of a film 4a fed out of the apparatus is movably arranged at a predetermined distance.
A conveying means B is disposed on a path passing from the film holding section 5 to the packaging section b. The conveying means B sandwiches the leading end of the film 4a held by the film holding section 5 with the conveying means B. Draw out a predetermined length and cut it,
The cut film 4 'is stretched around the packaging part b, and the film 4' is pre-stretched so that it can be stretched and packaged according to the depth dimension of the article to be packaged. Further, left and right folding plates 6 and 6 'and a rear folding plate 7 are arranged above the conveying means B so that the end of the film 4' covering the upper surface of the packaged object a is folded toward the bottom surface of the product. A discharge pusher 10 is disposed above the rear folding plate so as to discharge the packaged articles.

The conveyor 1 comprises a first conveyor 101 in which a plurality of belt-like belts are arranged in parallel at a predetermined interval, and a second conveyor
The conveyor 102 is configured to partially overlap, and the transport speed of the first conveyor 101 on which the packaged object a is supplied and placed is higher than the transport speed of the second conveyor, and the packaged object is placed on the elevator 2. A stopper 103 for receiving the front end of the packaged article a carried in by the first conveyor 101 is fixed on the belt surface of the second conveyor 102 that conveys a. As a result, the transport of the packaged object a is performed by the stopper 1.
03 is performed on the basis of the front end where the front end of the packaged object a is abutted. The end of the second conveyor 102 for transporting the packaged article a onto the elevator 2 in the transport direction is the elevator 2
And the conveyor surface of the second conveyor 102 is located above the surface of the elevator head 201.

The elevator head 201 of the elevator 2 on which the article to be packaged is mounted has at least left and right folding plates 6, 6 '.
And, when one of the folding plates of the rear folding plate 7 abuts, it is configured to fall down (tilt).

A film 4 'stretched over a wrapping part b above the elevator 2 is pulled out from a film roll 4 set on a film roll placement part 3, and a film holding part 5 holding the leading end of the film is placed under the film. The lower holding plate 5 is fixed via an engaging portion 502 to an endless belt 501 disposed in parallel with a gap equal to or greater than the maximum width of the film roll 4 set on the film roll disposing portion 3 positioned on the side.
03 and the film 4 supported on the surface of the lower holding plate 503
The upper holding plate 504 for holding a with a slight gap by the lower holding plate 503, the holding roller 505 attached to the lower holding plate 503, and the film holding portion 5 are directed toward the film transport means B. And a moving means 8 for moving the film. The leading end of the film roll 4 set in the film roll disposing unit 3 is transferred to the film holding unit 5 via a feeding roller 9 disposed above the film roll disposing unit 3. Supplied (see FIGS. 2 to 4). The film holding section 5 is installed so as to move horizontally between the feeding roller 9 and the conveying means B on the conveying plane line (flow line) of the film 4a in the conveying means B described later.

The lower holding plate 503 is a flat plate having a rectangular planar shape, and has engaging portions 502 on both sides in the width direction near the feeding roller 9.
The holding roller 505 is rotatably supported by bearings 506 provided at both ends. Further, at the leading end of the lower holding plate 503 near the conveying means B, a position corresponding to the reference side of the film roll 4 (the lower side of the film roll width indicated by the two-dot chain line in FIG. 3) and several types having different roll widths ( Notches 507 and 507 'are respectively formed at positions corresponding to the opposite sides of the film roll 4 (three types in the drawings), so that both sides in the width direction of the held film are exposed.

The holding roller 505 is a so-called stepped roller in which the diameter corresponding to the notch 507 on the reference side and the notch 507 'on the opposite side is large and the diameter of the other portions is small. A one-way clutch is built in the roller and is configured to be rotatable only in the film unwinding direction. In addition, the surface of the portion having a large diameter, that is, the surface that comes into contact with the film is mirror-finished to enhance the adhesion to the film.

The upper holding plate 504 is supported with a small gap from the lower holding plate 503, and is a flat plate having substantially the same shape as the lower holding plate 503. The notches 507, 507 'are formed so as to be located on the same line as the notches 507, 507' formed on the plate 503. The upper holding plate 504 is formed with an engaging portion 502 ′ that engages with the engaging portion 502 of the lower holding plate 503, so that the upper holding plate 504 moves together with the lower holding plate 503. (See FIG. 6). The upper holding plate 504 is integrally supported via a mounting piece 511 on a guide shaft 510 provided inside an openable and closable protective cover 509 that covers the upper part of the film holding portion 5, and the protective cover 509 is closed. Then, lower holding plate 503 and upper holding plate 5
04 is moved horizontally along the guide shaft 510 as a unit.

The moving means 8 includes a rotating shaft 801 'of the motor 801.
The connecting portion 502 of the lower holding plate 503 is connected to the sprocket 802 fixed to the feeding roller 9, the sprocket 803 fixed to the shaft 9 ′ of the feeding roller 9, and the idle sprocket 804 and the tension sprocket 805 arranged on the conveying means B side. The upper and lower holding plates 504, 503 and the holding roller 505 are driven by a motor 801.
Is horizontally reciprocated between the sprocket 803 and the sprocket 804.

The conveying means B includes a conveying belt B disposed on the line of the notch 507 of the lower holding plate 503 and the upper holding plate 504.
1 and two sets of a conveyor belt B2 arranged on the line of the notch 507 ', which are arranged in parallel with the packaging part b interposed therebetween, and are supported so as to be movable in the width direction of the film. The two conveyor belts B1 and B2 are a pair of upper and lower endless elastic belts 11 and 12, which sandwich the widthwise side end of the film 4 ', and the upper elastic belt 11 And a receiving plate inserted between the forward side and the backward side of the upper elastic belt 11.
14, and these components are supported by mounting frames 15, 15 'movable in the width direction of the film.

The mounting frames 15, 15 'are supported via connecting members 17, 17' on two guide rods 16, 16 'arranged at right angles to the lower side of the mounting frame. This mounting frame
15 and 15 'are two endless belts 18 and
When the endless belts 18 and 18 'rotate in opposite directions, the conveyor belt B1 and the conveyor belt B2 move parallel to each other outward in the width direction, and the size of the packaged object a ( The width of the film 4 'can be pre-stretched according to the height and the depth.

A pair of upper and lower elastic belts 11 and 12 of the transport belts B 1 and B 2 are driven by a drive mechanism (not shown).
The film 4 'is driven and rotated so that the film 4' can be conveyed while nipping the side end in the width direction.

At the beginning of the conveyor belts B1, B2,
A receiving portion C is formed so that the leading end of the film 4a held by the film holding portion 5 is drawn toward the receiving and conveying means B by the movement of the film holding portion 5. The receiving portion C is provided with an opening / closing roller on the axis of the starting end rollers 111 and 112 around which the pair of upper and lower elastic belts 11 and 12 are wound.
An upper frame 129 to which an 128 is attached and a lower frame 131 to which an opening / closing roller 130 is attached are mounted so as to be able to move up and down in the vertical direction.
It is wound by extending 1,12.

The opening / closing mechanism for opening and closing the upper frame 129 and the lower frame 131 of the receiving portion C in the vertical direction includes the mounting frames 15, 15 '.
The linear motion of the core rod that moves in and out by switching ON / OFF the electromagnetic solenoids 132 and 132 '
By 133, it is transmitted to the upper frame 129 and the lower frame 131 as a rotational motion. Thus, the upper frame 129 is configured to open and close in the vertical direction about the axis of the roller 111, and the lower frame 131 is configured to open and close in the vertical direction about the axis of the roller 112 (see FIG. 4). When the upper frame 129 and the lower frame 131 are closed, the receiving surface of the film formed by the two belts is in contact with the conveying surface (flow line) of the conveying means B that is continuous with the receiving portion C. The film is configured to be substantially straight, so that the film received from the film holding unit 5 can be transported without stress.

As shown in FIG. 2, a film cutting mechanism D for cutting the film 4a drawn by driving the conveying means B into a predetermined length is disposed between the receiving portion C and the film holding portion 5. . The film cutting mechanism D includes a cutter 34 disposed below the film 4a passed from the film holding unit 5 to the receiving unit C, and a cutter receiver 35 disposed above the film 4a. Cutter holder
35 is operated up and down when the electromagnetic solenoids 36 and 37 are turned on, respectively, and when the electromagnetic solenoids 36 and 37 are turned off, both are urged to return to the separated initial position. The cutting edge (saw tooth) of the cutter 34 enters the film surface stretched between the film holding portion 5 and the receiving portion C at an acute angle, and there is almost no speed difference between the cutter 34 and the film 4a in the moving direction of the film. It has become.

A film 4 'of a predetermined length used for packaging is cut by the film cutting mechanism, and the leading end of the film on the film roll 4 side is held by the film holding portion 5, but the leading end of the film is drawn into the film roll side. The holding means E for preventing the occurrence of such a situation will be described below. As shown in FIGS. 3 to 5, particularly FIG.
It is composed of a film contact member 21 and a film pressing member 22. The film sticking member 21 is located at a position shifted downward from the film transfer surface and at the front lower portion of the lower holding plate 503 of the film holding section 5, and has both side ends fixed to the machine frame A to hold the lower side. It is suspended across the entire width of the plate 503. The contact member 21 is formed of a material capable of supporting the film in close contact, and has a structure in which, for example, a mirror-like plastic plate is adhered to the surface of a metal strip. Film pressing member 22
Is constituted by a long member so as to move toward and away from the upper surface of the close contact member 21 from above, and in the embodiment, a structure in which a sponge material is adhered to the bottom surface of the rear leg 35 'of the cutter receiver 35 of the cutting mechanism D. Is shown.

Next, the operation of each part relating to packaging and the operation of clamping the leading end of the film will be described with reference to the time chart of FIG. In the drawing, the solid line indicates the case of a film having standard characteristics. Control of each part of the packaging machine is performed based on a rotation angle of a cam 38 for driving the elevator 2, and one cycle of the packaging is performed when the cam 38 makes one rotation. The rotation angle of the cam is detected by counting output pulses from the rotary encoder 39 attached to the cam shaft and detecting the count value. By one rotation of the cam 37, the elevator 2 moves up and down at the timing of (3). That is, the elevator 2 moves up and down in the latter half of one packaging cycle, and the transporting of the packaged object by the transport conveyor 1, the drawing out of the film by the transporting means B, centering, and pre-stretching are performed in the first half of the one packaging cycle. The conveyor 1 for carrying in the package is turned ON / OFF at the timing (4), and the conveyor B is turned ON / OFF at the timing (5). The cutter 34 and the cutter receiver 35 of the film cutting mechanism D are operated to cut the film while the conveying means B is in the ON state, that is, while the film is being pulled out, and the cut film 4 'is centered. Although the timing at which the conveying means B is turned off varies depending on the cut length of the film, in the case shown in the figure, the cut length is long, and when the cut length is short, it is turned off before the timing shown. The transporting means B pre-stretches the film 4 'in the width direction by moving the transporting means B1 and the transporting means B2 in a direction in which the distance between them is expanded. The timing of the pre-stretch is shown in (6) (the pre-stretch is performed when the line rises to the right). The pre-stretch amount changes according to the depth dimension of the packaged object a, and is indicated by a dotted line. Indicates the case of the maximum size. Also, (7) shows the timing of the left and right folding plates 6 and 6 ', (8) shows the timing of the rear folding plate 7, and (9) shows the timing of the discharge pusher 10. ing. Cutter holder 35,
The electromagnetic solenoid 37 is turned on together with the cutter 34 which is turned on / off at the timing (1) and turned on / off at the timing (2).
As shown by the solid line, the elevator 2 descends and the folding of the film is completed, and when the next film can be transported onto the packaging unit, the electromagnetic solenoid 37 is turned off and the initial position is set by the urging force. Return to Further, when the electromagnetic solenoid 37 is turned on so as to coincide with the timing of the end of folding, a timer may be started and the return time may be determined by the timer. In the operation of the cutter receiver 35, the broken line may be returned at a timing immediately before the start of the next film transport instead of returning at the end of packaging, in which case there is a period until the next packaged object comes. In this case, turn on the electromagnetic solenoid for the entire allowable heat generation time, and then turn it off. Alternatively, the ON / OFF timing may be reversed by reversing the operation direction and the urging direction of the electromagnetic solenoid. At this timing, there is almost no time for the leading end of the film to return to the film roll side, so that the return preventing effect is remarkable.

The film contacting member constituting the above-mentioned holding means is not necessarily required to have a tight contact with the other cutter receiver as long as it can firmly hold the leading end of the film with the other cutter receiver. There is an advantage that there is no need. Further, the cutting of the film is not limited to being performed during the drawing of the film, and the cutting of the film may be stopped. Further, the means for transporting the cut film to the packaging unit is not limited to the embodiment in which the film is nipped on both sides in the width direction, and may be a form in which the front end of the film is gripped and transported . Also, feeding roller 9, the moving speed of the conveyance means B and the film of the film 4a is a common driving source to be the same. In adjusting the tension at the time of cutting the film, the tension can be increased by applying the brake earlier than the cutting. Further, the pressing of the film (to the film contact member) at the time of cutting is not limited to being performed by the cutter receiver, and the position of the film contact member is set above the film holding portion so that the film pressing member operates integrally with the cutter. It may be.
For example, as shown in FIG. 9, a pressing member 42 is attached to a cutter 40 operated by an electromagnetic solenoid, a close contact member 43 is attached to a cutter receiver 41, and the film is cut by the operation of the cutter 40. May be sandwiched between the pressing member 42 and the close contact member 43. Further, a pressing member or a close contact member independent of the cutter and the cutter receiver may be used.

[0026]

According to the first aspect of the present invention, the stretch wrapping machine of the present invention holds the leading end of the film on the film roll side with the film holding portion almost simultaneously with the cutting of the film and holds the film until the packaging is almost completed. In addition, the returning speed of the film is reduced, so that the return (pull-in) of the leading end of the film in the film holding portion can be reduced. In particular, when a large number of packages are successively packed, the time required for the film to shrink can be reduced, and the return of the film tip can be reduced. This allows the film to be pulled for the next package.
We offer a stretch wrapping machine that can perform
Can be provided. Since the return of the film can be reduced as described above, the tension at the time of cutting the film can be increased to facilitate cutting. Further, according to the configuration of the second aspect, since the leading end of the film is held until immediately before drawing out the film for the next packaged object, the returning speed of the film is reduced, and the returning of the leading end of the film in the film holding portion can be reduced. . Since the return of the film can be reduced as described above, the tension at the time of cutting the film can be increased to facilitate cutting. In addition, even if there is a long time until the next packaged object is carried in, the time required for the film to shrink is shortened, so that the effect of preventing the leading end of the film from returning can be enhanced.

Furthermore, according to the third aspect of the present invention, a cutter or a cutter receiver can be used for driving for holding, so that the configuration can be simplified and manufactured at low cost, and the timing of interlocking with the cutting operation can be adjusted. It can be done reliably. Further, according to the configuration of claim 4, it is possible to increase the tension of the film, to obtain a clean film cutting edge by cutting during film drawing without worrying about the return of the film front end in the film holding portion, The film can be quickly conveyed to the packaging unit.

[Brief description of the drawings]

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

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

FIG. 3 is an enlarged plan view showing a film holding unit.

FIG. 4 is an enlarged view showing a configuration of a film holding unit and a receiving unit.

FIG. 5 is a perspective view illustrating a relationship between a film holding unit, a conveying unit, a receiving unit, and a holding unit.

FIG. 6 is an enlarged sectional view of an engaging portion showing engagement between a lower holding plate and an upper holding plate constituting a film holding portion.

FIG. 7 is a partial view corresponding to FIG. 4, and is a front view showing a state in which the film is being conveyed and before the holding means is operated.

FIG. 8 is a front view showing a state in which the holding means is operating in the film cutting step in the same manner.

FIG. 9 is a partial front view showing another example of the holding means.

FIG. 10 is a time chart illustrating an operation of a part related to packaging.

[Explanation of symbols]

 A: Machine frame B: Conveying means B1, B2: Conveying belt C: Receiving part D: Film cutting mechanism E: Holding means 1: Conveying conveyor 2: Elevator 4: Film roll 5: Film holding part 21: Film adhesion member 22: Film pressing member

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B65B 11/00-11/48 B65B 41/00-41/18

Claims (4)

(57) [Claims] 1. A conveyor means holds the film leading end of the full Irumuroru side film holding portion by a predetermined distance moved
To receive the leading edge of the film
Is pulled out to a predetermined length and cut, and the cut film of a predetermined length is conveyed by a conveying means and stretched over a packaging portion. In a stretch wrapping machine that covers with a film end and folds the end of the film to the bottom of the packaged object, near the front end of the film holding portion, almost simultaneously with cutting a predetermined length of the film, the front end of the film on the film roll side is cut and cut. A stretch wrapping machine, characterized in that a wrapping means for releasing the wrapping of the leading end of the film is provided at a timing when the packaging with the separated film is almost completed. 2. A conveying means for moving a predetermined distance while holding a leading end of a film on a film roll side by a film holding section.
To receive the leading edge of the film
Is pulled out to a predetermined length and cut, and the cut film of a predetermined length is conveyed by a conveying means and stretched over a packaging portion. In a stretch wrapping machine that covers with a film end and folds the end of the film to the bottom of the article to be packaged, near the front end of the film holding section, almost simultaneously with cutting a predetermined length of the film, the front end of the film on the film roll side is sandwiched. A stretch packing machine provided with a holding means for performing the holding until immediately before drawing out a film for an article to be packaged. 3. The stretch wrap according to claim 1, wherein one of the holding members constituting the holding means is connected to a cutter or a cutter receiver which approaches the cutter at the time of cutting. Machine. 4. The stretch packaging machine according to claim 1, wherein the cutting of the film is performed while the film is being drawn.