JPH089363B2 - 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 stretch wrapping machine, and in particular, the four side edges of a wrapping film drawn into a wrapping section are folded into the bottom side of an article to be packed (product) carried into the wrapping section. The final folding is related to the improvement of the clamp device of the stretch wrapping machine in which the unloading operation of the article to be packaged and the releasing operation of the wrapping side film edge of the clamping device are performed in conjunction with each other.

[0002]

2. Description of the Related Art Conventionally, a packaging film is pulled out to a packaging portion, and four side edges of the film are folded to the bottom side of the packaging object carried into the packaging portion to package the packaging object. There are two types of stretch wrapping machine: a type that draws the film into the wrapping section in a direction orthogonal to the loading direction of the article to be packed, and a type that draws the film into the wrapping section in a direction parallel to the loading direction. Is mainly known. The maximum film width of the packaging film especially used for these packaging machines is about 500 mm because it is easily available and inexpensive.

However, the conventional packaging machine described above, the former,
In the latter case, the four side edges of the film are folded into the bottom side of the packaged article (product) that has been loaded into the packaging section. When the folding is performed, the final folding is performed by interlocking with (cooperating with) the transporting operation of the packaged article. The clamp width (grip width) of the clamp device for gripping the side film edge is constant. That is, the above-mentioned clamping device of the conventional packaging machine always keeps the final folding edge of the film at a constant clamping width by a fixed clamping plate disposed above the edge and a movable clamping plate disposed so as to face the lower portion thereof. Since it has a gripping structure, the above-mentioned 500 mm wide film is used, for example, in the case of a packaged product having a size of 360 mm × 260 mm square large tray (for meat, etc.)
As indicated by the diagonal lines in (a), the folding edge width l to be folded at the end is reduced, and the exposed portion 60 is likely to be formed on a part of the bottom of the tray, and the reliable heat sealing required for this type of packaging cannot be achieved. May occur.

This inconvenience can be solved by widening the clamp width (grasping width) of the film edge as shown in (b), but on the other hand, the number of products is much larger than that of the packaged object using a large tray and a large amount. For example, in the case of an object to be packaged using a small tray of 145 mm x 90 mm square used in, the folding edge width l'to be folded at the end is too wide as shown by the slanted line and the protruding portion 61 protruding from the bottom of the tray 61. If you do, you will not be able to package correctly.

It is also conceivable to blister stretch the film in the width direction to expand and wrap the film, but a complicated pre-stretching mechanism is required, and there is a risk that the object to be packaged will be monitored by the hearing of the film. Therefore, according to the conventional packaging machine for a large tray, which is manufactured with a clamp width corresponding to the film width for packaging the packaged object using the large tray, and the film width for packaging the packaged object using the small tray. Two units are required, including a small tray packaging machine manufactured with a clamp width.

As a method for solving the above-mentioned inconvenience that occurs when packaging an article to be packaged using a large tray,
This can be solved by using a film having a width of 600 mm because the folding width of the film edge in the direction orthogonal to the film edge to be finally folded can be widened. However, 600
mm-width film is less available than 500 mm-width film, so it is difficult to obtain, and because it is not produced in large quantities, it is expensive and costly. Also, 6
A number of problems occur, such as having to separately manufacture a wrapping machine large enough to pull out a 00 mm wide film into the wrapping section.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and it is possible to properly package an object to be packaged using a large tray or an object to be packaged using a small tray. Moreover, it is an object of the present invention to provide a stretch wrapping machine capable of reducing the amount of film used.

[0008]

To achieve the above object, the technical means taken by the present invention are as follows. The four side edges of the packaging film pulled out to the packaging part are the objects to be packaged carried into the packaging part. In the stretch wrapping machine, the final fold of the film to be folded into the bottom side is carried out by the carry-out operation of the article to be packaged and the clamp device which holds the final fold film edge, thereby gripping the film edge. It is characterized in that the clamp width of the clamp device is variable and is variable according to the width of the film drawn to the wrapping portion or the cutting length thereof or the size of the article to be wrapped.

The clamp device includes a fixed clamp plate and a movable clamp plate for gripping the film edge from above and below,
A fixed clamp plate or a movable clamp plate, wherein the fixed clamp plate or the movable clamp plate is provided with a pair of divided clamp plates that move toward and away from each other in the edge direction of the film. Is provided with a pair of split clamp plates that move in and out of each other, and the spacing between the pair of split clamp plates is determined according to the film width or the cutting length of the selected film drawn into the packaging unit. The feature is that it can be changed.

Further, the pair of clamps are arranged so that the contact / separation distance between the pair of divided clamp plates can be varied in a direction orthogonal to the drawing direction of the film drawn into the packaging section and move in the width direction corresponding to the film width. It is characterized in that it is performed in conjunction with the movement of the device.

[0011]

According to the above-mentioned technical means of the present invention, the clamp device determines the clamp width according to the film width of the film drawn into the wrapping portion or the cut length thereof or the size of the packaged object. Changeable. As a result, when the four side edges of the film are folded into the bottom side of the package that has been carried into the packaging unit, the unloading operation of the package and the cooperative operation with the clamp device that holds the final folded film edge. The final film edge that is folded to the bottom side of the package is folded with a correct folding edge width that does not cause an unwrapped exposed portion at the bottom or protrude from the bottom.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 to FIG. 4 are parallel to a carrying-in direction X of an article to be packaged (hereinafter referred to as a commodity) 1 into a packaging section A. Shows the entire packaging machine of the type in which the film 2 is pulled out to the packaging part A from the direction, that is, the facing direction (the film pulling direction Y),
The product 1 is from the product supply device B (from the left side in FIG. 1)
It is once transported to the weighing conveyor device C by the supply conveyor 3 and is also transported from the weighing conveyor device C to the elevator / conveyor device D by the belt conveyor 4 and lifted into the packaging section A by the elevator mechanism 5.

On the other hand, the film 2 is pulled out from the film feeding device E (from the right side in FIG. 1) by the film pulling-out device F so that its front edge 2a is grasped and pulled out to the wrapping section A by a predetermined length. Left and right side edges by a pair of left and right clamp devices G arranged in a direction orthogonal to the drawing direction Y
The front edge 2a of the film 2, the left and right side edges 2b, and the rear edge 2c of the film 2 are grasped by the rear clamp device I disposed on the film supply device E side while the 2b is grasped. The four side edges are retained. Thereafter, the film 2 is moved by the film cutting device H to the film supply device E and the rear clamp device I.
To be separated between.

Then, the product 1 is pushed up by the elevator mechanism 5 toward the film 2 whose four side edges are held, and after the product 1 is pushed up and carried into the packaging section A, the front edge 2a and both side edges of the film 2 are conveyed. 2b is folded into the bottom side of the product 1 by the film folding devices J and K on the front and left and right sides at substantially the same time, and the product 1 is carried out of the packaging part A by the pusher 6 to the carry-out device M. By the operation and the cooperative operation of the rear clamp device I, the last trailing edge 2c is folded to the bottom side of the product 1 to complete the packaging.

The product 1 conveyed from the product supply device B to the weighing conveyor device C by the supply conveyor 3 is centered by the width-shifting device N while being moved to the center of the supply conveyor 3. At the same time, the product width is detected, and the size (height and length) is detected by the detectors 7 and 8. That is, based on the detection result, either one of the two films 2 and 2'having different widths individually arranged in the film supply device E is selected based on the detection result of the width of the product 1. The product 1 is pulled out to the packaging section A by the pull-out device F and
The pull-out length is selected based on the length detection result and the height detection result, and the film is cut by the film cutting device H.
Further, the weight of the product 1 is detected by the weight detector 9 in the weighing conveyor device C.

The elevator / conveyor device D comprises an elevator mechanism 5 having a conveyor 11 and an elevator head 10 at its upper end, and conveys the product 1 conveyed by the belt conveyor 4 to the conveyor 11.
The product is received and introduced into the elevator head 10, and the elevator head 10 on which the product 1 is introduced and placed is lifted by the elevator mechanism 5 to carry the product 1 into the packaging unit A. The conveyor head 11 is provided with the elevator head 10 in a substantially penetrating manner in order to position the product 1 against the stopper 12 (see FIG. 2), but the elevator head 10 is synchronized with the lift of the elevator head 10.
It is arranged so that it can be swung from the ascending path of 10 to the position where it is retracted.

In the rear clamp device I, after the film 2 is pulled out by the film pull-out device F to the packaging portion A by a predetermined length, the trailing edge 2c, that is, the product 1 carried into the packaging portion A.
The four side edges of the film 2 are folded on the bottom side of the packaging, and the trailing edge 2c of the film 2 that is folded last when the folding is performed is grasped and clamped, and is horizontally laid across both left and right side plates 13 of the packaging machine. A fixed clamp plate 14 and a clamp mechanism 16 attached to a support plate 15 that is installed below the fixed clamp plate 14 in parallel at a predetermined interval. The air that constitutes the clamp mechanism 16 disposed at the central position of the support plate 15 is formed. A movable clamp plate 17 is provided on the upper surface of an elevating frame 16b connected and supported to the rod tip of the cylinder 16a, and guides 18 for slidably supporting the supporting plate 15 are fixedly hung on both lower surfaces of the elevating frame 16b ( 7 to 8).

Then, a pair of divided clamp plates 19 which move to and from the fixed clamp plate 14 or the movable clamp plate 17 of the clamp device I so as to move toward and away from each other in the edge direction of the trailing edge 2c of the film 2, that is, in the width direction of the film 2. Equipped with.

The pair of split clamp plates 19 are made to fold lastly by changing the contact / separation interval L (clamp width) according to the film width of the film 2 drawn out to the wrapping section A by the film drawing device F. When the trailing edge 2c is folded into the bottom side of the product 1, the unwrapped exposed part does not occur at the bottom of the product 1 or the trailing edge 2c is folded so that it does not protrude from the bottom so that the trailing edge 2c is folded. Clamping, movable clamp plate in the embodiment
On the lower surface of the fixed clamp plate 14 in the range where 17 abuts,
A fixed clamp plate is fixedly connected to a sliding plate 30 that supports an end of a fixed clamp plate 24 of a left and right clamp device G described later.
The left and right connecting frames 20 along the lower surface of 14 are fixedly supported, respectively, so that the contact / separation distance L between them can be varied in association with the movement of the left and right clamp devices G in the width direction of the film 2 ( (See FIG. 4).

In the figure, reference numeral 21 indicates the pair of left and right split clamp plates 19 described above.
A fixed split clamp plate is provided by being fixedly attached to the lower surface of the fixed clamp plate 14 provided with at the center between the split clamp plates 19, and a film is formed together with the pair of split clamp plates 19 by the contact of the movable clamp plate 17. The second rear edge 2c is gripped and clamped. That is, the pair of left and right split clamp plates 19 interlock with the fixed split clamp plate 21 (as a center) so as to change the contact / separation distance L from each other in conjunction with the movement of the left and right clamp devices G in the width direction of the film 2. It can be moved in and out.

Thus, the product 1 is conveyed from the product supply device B to the measuring conveyor device C by the supply conveyor 3 and the film 2 of the width selected according to the size thereof is moved by the film drawing device F to move its front edge 2a. When grasped and pulled out to the wrapping section A, it is arranged on the lower surface of the fixed clamp plate 14 of the rear clamp device I in conjunction with the movement of the left and right clamp devices G that move in the width direction according to the film 2 of the selected width. The pair of left and right divided clamp plates 19 are moved toward or away from each other, and the contact / separation distance L between them is made variable according to the width of the film 2 (see FIG. 4).

Then, the left and right side edges 2b of the film 2 pulled out to the packaging portion A by a predetermined length are gripped by the left and right clamp device G, and the rear edge 2c of the film 2 is moved to the air cylinder 16
The movable clamp plate 17 comes into contact with the split clamp plate 19 and the fixed split clamp plate 21 at the center when the elevating frame 16b, which is moved up and down by the operation of a, ascends to hold the movable clamp plate 17 (state of FIG. 6B). The front edge 2a of the film 2 and the side edges 2b of the film 2 are almost simultaneously at the same time by the film folding devices J and K on the front and left and right sides.
When the unloading operation is started in which the product 1 is unloaded from the wrapping section A to the unloading device M by the pusher 6 after being folded to the bottom side, the air cylinder that operates at substantially the same time or at a predetermined timing as the unloading operation starts. Lifting frame 16 by 16a
When b is lowered, the movable clamp plate 17 is
And the trailing edge 2c is finally folded into the bottom side of the product 1 by the cooperation operation with the edge opening operation of moving away from the fixed split clamp plate 21.

Therefore, the trailing edge 2c of the film 2 which is finally folded on the bottom side of the product 1 by the cooperative operation of the unloading operation of the product 1 to the unloading device M by the pusher 6 and the edge opening operation of the rear clamp device I. , A gripping width (clamping width) corresponding to the width of the film 2 selected by a pair of left and right divided clamp plates 19 that change the contacting / separating distance L of the film 2 drawn out into the packaging portion A from each other. Since the product 1 is folded, there is no unwrapped exposed portion at the bottom of the product 1 and there is no packaging failure such as protruding from the bottom, and the product 1 can always be packaged correctly.

The contacting / separating movement of the pair of left and right split clamp plates 19 that moves toward and away from each other to change the contact / separation distance L between them is, as described above, the movement of the left / right clamp device G in the film width direction. It is also possible to use a manual type instead of the linked automatic type. In this case, the fixed clamp plate 14 of the rear clamp device I is provided with elongated holes extending in the contact and separation directions, and the divided clamp plates 19 are attached to the left and right elongated holes by appropriate fastening means such as screws. Further, it is preferable to connect a pair of left and right split clamp plates 19 by a linking means so as to synchronize the movements of the both, if necessary.

The left and right clamp device G is for simultaneously gripping and clamping both left and right edges 2b of the film 2 when the film 2 is drawn out by the film drawing device F into the wrapping part A. The fixed clamp plate 14 and the movable clamp plate 17 of the rear clamp device I are provided across the space between the left and right side plates 13 of the packing machine on the side of the drawer device F so as to face the support plate 15 supported by the clamp mechanism 16. Of the upper and lower two guide rods 22 and 23 installed in parallel at intervals, a fixed clamp plate 24 installed over the upper guide rod 22 and the fixed clamp plate 14, a lower guide rod 23, and a support plate 15. The upper surface of the elevating frame 26b that is connected to and supported by the rod tip of the air cylinder 26a that comprises the clamp mechanism 26 attached to the support plate 25 that is installed over the Acceptable to Fixed vertical set a guide 28 which slidably penetrates supported on the support plate 25 on both sides the lower surface of the lifting frame 26b provided with a clamping plate 27 (see FIG. 5).

The upper guide rod of the fixed clamp plate 24
A mover 29 is provided at one end on the 22 side, and the mover 29 is slidably fitted into the upper guide rod 22 and fixed clamp plate.
A slide plate 30 is provided at the other end on the 14 side, and the slide plate 30 is slidably mounted on the fixed clamp plate 14 of the rear clamp device I, and the fixed clamp plate 24 is attached to the film 2 width. It can be moved in any direction.

On the other hand, a support plate having a movable clamp plate 27
A mover 29 is also provided at one end of the lower guide rod 23 on the side of the lower guide rod 23 so that the mover 29 can be slidably fitted into the lower guide rod 23 and a sliding plate can be attached to the other end of the support plate 15 side. 30 is provided, and the sliding plate 30 is slidably mounted on the support plate 15 having the movable clamp plate 17 of the rear clamp device I, and the support plate 25 is provided.
Is also movable in the width direction of the film 2.

The movement of the left and right clamp device G in the width direction of the film 1 is carried out by linking the movable element 29 provided at the end of the fixed clamp plate 24 and the support plate 25 to the link 31 as shown in FIGS. Via the gears 34 driven by the motor 33, and the upper and lower ends of the rotary shafts 35 tuned to each other by the gear mechanism 34 driven by the motor 33. The rotation shaft 35 is moved forward or backward to move in the approaching or separating direction. Further, the size (width) of the product 1 in the width direction of the film 2 of the left and right clamp device G and the setting of the movement amount based on the film 2 having the width selected accordingly are set by the timing circle attached to the rotary shaft 35. This is done by the plate 36 and the detector 37.

The elevator mechanism 5 divides the elevator head 10 into two groups, a main head 10a and an auxiliary head 10b, and a supporting rod for supporting the heads 10a and 10b is divided into a main supporting rod 38 and an auxiliary supporting rod 39. When the product 1 is small, only the main head 10a is lifted (moved up and down) when the product 1 is small, and when the product 1 is large, both the main head 10a and the auxiliary head 10b are lifted to allow use of the tip (Fig. 1, Fig. 1, Fig. 1). 2).
That is, as shown in FIGS. 9 to 10, the swing arm 42 is attached to the main base 40 attached to the lower end of the main support rod 38 via the link 41.
The main support rod 38 is always moved upward by the swinging of the arm 42, and the main base 40 is provided with an air cylinder 43, and a connecting pin 44 which is retracted by the operation of the cylinder 43 is provided. A connecting portion is provided at the lower end of the auxiliary supporting rod 39.
An auxiliary base 46 having 45 is provided, and a connecting hole 47 for fitting the connecting pin 44 is formed in the connecting portion 45.

Further, a light transmission type detector 48 is provided on the main base 40.
The air cylinder 43 rod and connecting pin
A flag 50 is provided on the connector 49 for connecting with 44, and this flag is
The connection state between the connection pin 44 and the connection hole 47 is detected by the detection operation of the detector 48 which detects the movement of 50.

In FIG. 1, reference numeral 51 is a main motor, and a cam shaft 53 is linked to the main motor 51 via a gear mechanism 52. A cam 54 attached to the cam shaft 53 has a cam floor 55 and a lever 56. The swing arm 42 described above is connected via the rotary shaft 57, and the swing arm 42 is swingably arranged by the rotation of the cam 54. The swinging arm 42 has its swinging end connected to the elevator mechanism 5 and is swung by the rotation of the cam 54 so that the elevator mechanism 5 moves to the elevator head.
It is designed to move up and down 10. Reference numeral 58 is a timing disc, and the timing disc 58 controls the operation timing of each of the above-mentioned parts of the packaging machine.

Incidentally, in the above-mentioned embodiment, FIG.
As shown in FIG. 2, the left and right edges 2b of the film 2 pulled out to the wrapping section A are gripped by the left and right clamp devices G arranged in the direction orthogonal to the carrying-in direction X of the product 1 into the wrapping section A. Although detailed description has been given as the form, as shown in (b), the left and right clamp devices G may be arranged in parallel on both sides of the rear clamp device I.

Further, the carrying-out direction of the product 1 from the packaging section A is not limited to the facing direction parallel to the carrying-in direction X, but the carrying-out direction of returning (folding back) to the carrying-in direction X side (left side in FIG. 1). It may be in the form. In this case, the pair of divided clamp plates 19 are arranged in the film drawing device F.
FIG. 12 shows another embodiment of the film withdrawing direction Y in which the film 2 is withdrawn into the packaging unit A from a direction orthogonal to the carrying-in direction X of the product 1 into the packaging unit A. 1. A pair of divided clamp plates 19 are arranged on the side of a clamp device that holds one side edge of the film 2 folded into the bottom side of the film 1, and the divided clamp plates 19 are made variable according to the length of the film 2 to be cut. The configuration.

When the film is pulled out in the same direction as the loading direction X of the product 1, the clamp width of the edge folded at the bottom of the product 1 is changed according to the width of the film.
When the film is pulled out from the direction orthogonal to the carrying-in direction X of the product 1, the clamp width is changed according to the length of the film. However, in the former case, the film width is selected according to the width of the product 1, while in the latter case, the film length is selected according to the width of the product 1. This is because the film width or the film cut length has a correspondence relationship with the width of the product 1. However, even if the clamp width is varied according to the width of the product 1, the same effect can be obtained. Yes.

Further, in the above-mentioned embodiment, the clamp width of the film edge which is finally folded on the bottom side of the product 1 is changed.
Although detailed description has been given as a configuration in which the pair of divided clamp plates 19 arranged so as to be movable toward and away from each other are changed, the clamp width is changed according to the film width or the film cutting length or the size (width, etc.) of the product 1. Any configuration can be used, and the specific configuration is not limited to the configuration described above.

[0036]

Since the stretch wrapping device of the present invention is constructed as described above, the correct folding edge depending on the size of the object to be packaged using the large tray or the object to be packaged using the small tray is provided. Can be folded in width. Therefore, unlike the conventional case, there is no unsuccessful packaging such as an unwrapped exposed portion at the bottom of the article to be packaged or protruding from the bottom, and the article to be packaged can be always correctly and beautifully packaged.

Moreover, the size range of the wrapping object that can be wrapped is widened, and it is difficult to obtain, and the price is high. Even a large wrapping object using a large tray can be correctly wrapped without using a 600 mm wide film. Therefore, it is possible to significantly reduce the amount of film used.

Further, the divided clamp plates are interlocked with the movement of a pair of clamp devices that move in the width direction of the film arranged in the direction orthogonal to the drawing direction of the film drawn out to the packaging section, and the contact / separation distance L between them is set. Since it is made variable, the split clamp plates are brought into contact with and separated from each other by a pair of clamp devices that move in the width direction according to the film of the selected width, and the contact distance L between them is ensured according to the film width. And it can be changed accurately.

[Brief description of drawings]

FIG. 1 is a side view showing an example of implementation of a stretch wrapping machine of the present invention.

FIG. 2 is a plan view taken along the line II-II of FIG.

FIG. 3 is a plan view taken along the line III-III in FIG.

FIG. 4 is an enlarged plan view of a main part viewed from the opposite side of FIG.

5 is a vertical cross-sectional side view taken along the line VV of FIG.

6 is an enlarged sectional view taken along line VI-VI of FIG.
Shows the state before gripping (before clamping), and (b) shows the state where the trailing edge of the film is gripped.

FIG. 7 is a vertical sectional front view taken along line VII-VII of FIG.

[Fig. 8] The same V with the right and left edges of the film held
It is a vertical front view which follows the II-VII line.

FIG. 9 is an enlarged side view of an elevator mechanism portion.

10 is a cross-sectional plan view taken along the line XX of FIG.

FIG. 11 is a schematic view of an embodiment showing an arrangement form of the left and right clamp devices, in which (a) is a state in which the left and right clamp devices are arranged in a direction orthogonal to the carrying-in direction of the article to be packaged (product), (B) shows a state in which the left and right clamp devices are arranged side by side on the rear clamp device.

FIG. 12 is a schematic view showing another example of the film withdrawing direction in which the film is withdrawn to the wrapping portion from a direction orthogonal to the carrying-in direction of the article to be wrapped into the wrapping portion.

FIG. 13 is a schematic view showing a packaging state of an object to be packaged caused by a clamp width of a film edge to be finally folded, and (a) shows that the film edge is clamped with a clamp width when a small object to be packaged is packaged. The state (b) shows a state in which the film edge is clamped by the clamp width when packaging a large object to be packaged.

[Explanation of symbols]

A ... Wrapping part G, I ... Clamping device 1 ... Wrapped product (product) 2 ... Film 14, 24 ... Fixed clamp plate 17, 27 ...
Movable clamp plate 19 ... Split clamp plate L ... Contact / separation interval

Claims (3)

[Claims] 1. The final folding of folding the four side edges of the packaging film pulled out to the packaging section to the bottom side of the packaged article carried into the packaging section is the unloading operation of the packaged article and its final folding. In a stretch wrapping machine that is carried out in cooperation with a clamp device that holds the film edge,
Stretch characterized in that the clamp width of the clamp device for holding the film edge is configured to be variable, and is variable according to the width of the film drawn to the wrapping portion or the cutting length thereof or the size of the object to be wrapped. Wrapping machine. 2. The clamp device according to claim 1, wherein the clamp device includes a fixed clamp plate and a movable clamp plate that grip the film edge from above and below; A pair of split clamp plates that move freely; and a distance between the pair of split clamp plates that is in contact with or separated from each other, the film width of the film drawn into the wrapping portion, the cutting length thereof, or the size of the packaged object. Stretch wrapping machine characterized by changing according to. 3. The variable contact distance between the pair of split clamp plates according to claim 2, wherein the distance between the pair of split clamp plates is variable in a width direction corresponding to a film width, the width being provided in a direction orthogonal to a drawing direction of the film drawn into the packaging portion. A stretch wrapping machine, which is operated in conjunction with movement of a pair of moving clamp devices.