JPH08151009A - Stretch packing machine - Google Patents

Abstract

PURPOSE: To increase the treating speed, by lowering an elevator immediately after folding motion of right and left folding plates in a stretch packing machine. CONSTITUTION: This device is provided with right and left folding plates 4a folding up a film (e), which are constituted of the upper and lower right and left folding plates 42, 41. A subsequent folding plate 5 is provided between the right and left folding plates 42, 41 of both upper and lower stages so as to be movable back and forth. A means to lower the elevator 2 in the mean time until the subsequent folding plate 5 is actuated after the right and left folding plates 4a have been actuated to fold up the film, is provided to increase the treating speed of the packing process.

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 more specifically, it pushes up an article to be packaged with respect to a horizontally stretched film, and folds the left and right and rear sides of the film to the article to be packaged. The present invention relates to an improvement of a stretch wrapping machine that folds the front side of a film while discharging the objects to be wrapped after folding the bottom side.

[0002]

2. Description of the Related Art The front side referred to in the specification of the present application is a product discharge side. In the conventional stretch wrapping machine, the film is horizontally spread in the wrapping section for wrapping the object to be wrapped, and the elevator on which the object to be wrapped is placed is raised from below the film, thereby forming the film. Push up the item to be packaged, and fold the left and right and rear sides of the film to the bottom of the item to be packaged with the left and right folding plates and the rear folding plate provided around the packaging part, and then discharge the item to be packaged. However, there are those that fold the front side of the film.

[0003]

SUMMARY OF THE INVENTION In the above-mentioned stretch wrapping machine, when the film is folded, the left and right folding plates are horizontally moved along the bottom surface of the packaged object placed on the elevator. By folding the left and right of the film, and by inserting the rear folding plate horizontally between the object to be packaged and the left and right folding plates, the film folded left and right as described above is further directed from the rear side to the front side. The front side of the film is folded by folding and then ejecting the object to be packaged forward. Since the stretch wrapping machine is configured to horizontally insert the rear folding plate between the object to be packaged and the left and right folding plates, until the folding by the rear folding plate is completely finished, It was not possible to lower the elevator that was supported from below, and due to this delay, the processing speed for performing one stroke of packaging was reduced.

It is conceivable that the rear folding plate is configured to pass under the left and right folding plates in order to accelerate the descending timing of the elevator described above. The problem that the film folded on the bottom is gathered forward by the rear folding plate and swells left and right when folded, and then the film gathered when discharging the packaged item is caught on the left and right folding plates. Cause It is an object of the present invention to provide the stretch wrapping machine as described above with a function capable of lowering the elevator immediately after folding by the left and right folding plates, thereby improving the processing speed of packaging.

[0005]

In order to achieve the above-mentioned object, the present invention pushes a packaged object placed on an elevator up against a film horizontally stretched in a packaging section, and the film is left and right. In the stretch wrapping machine, which folds the front side of the film while discharging the article to be wrapped after folding the back side to the bottom surface of the article to be wrapped by the folding plate, comprises both left and right folding plates for folding the film left and right. Then, the left and right folding plates are respectively configured by an upper folding plate and a lower folding plate, and a rear folding plate is inserted between the upper and lower folding plates of the left and right folding plates to support the front and rear movable, and Means for lowering the elevator is provided between the start of the folding operation of the left and right folding plates and the folding of the rear folding plate.

The stretch wrapping machine described above folds the film by the left and right folding plates toward the center of the bottom surface of the article to be wrapped,
It is recommended to make it shallow at the upper folding plate and deep at the lower folding plate. Further, the stretch wrapping machine is more effective when the folding amount in the upper folding plate is deep on the front side of the article to be packaged and shallow on the rear side. Furthermore, in the stretch wrapping machine, the upper and lower folding plates may be integrally connected.

[0007]

According to the above means, the stretch wrapping machine of the present invention spreads the film horizontally in the wrapping section, pushes up the object to be packed placed on the elevator with respect to the film, and the film is folded by the folding plate. The left and right sides and the rear side of the film are folded into the bottom surface of the packaged object, and the front side of the film is folded while discharging the packaged object. As described above, the left and right folding plates for folding the film in a state where the article to be packaged is pushed up from the left and right are composed of the upper folding plate and the lower folding plate. A rear folding plate is inserted between the upper and lower folding plates so as to be movable back and forth.

The upper and lower folding plates constituting the left and right folding plates described above are folded from the left and right with respect to the film in a state where the object to be packaged is pushed up, and the left and right sides of the film are placed on the elevator. Fold it into the bottom of the package. At this time, the folding plate in the upper stage enters under the article to be packaged on the elevator together with the folding of the film and supports it from below. After the left and right folding plates on both upper and lower stages are folded, the rear folding plates provided between the upper and lower stages are activated, and the film folded on the bottom surface of the package by the left and right folding plates is further moved to the front side. Fold towards.

From the start of the folding operation of the left and right folding plates until the rear folding plate is folded, the elevator is lowered,
Operate for the next packaging process. After the folding of the film by the rear folding plate is completed, the objects to be packaged supported by the left and right folding plates are discharged toward the front while the front side film is folded to complete the folding of the film. Also,
When the amount of film folded by the left and right folding plates toward the center of the bottom of the package is shallow in the upper and right folding plates and deep in the lower left and right folding plates, the folding amount by the upper and right folding plates Since the thickness of the film becomes shallower, the catch of the end of the film folded to the front side by the rear folding plate is reduced when the packaged object is discharged. Further, in the case where the amount of folds in the upper left and right folding plates is deep on the front side of the packaged object and shallow on the rear side, the width of the folding margin at the time of folding by the rear folding plate can be ensured to be wide.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. The stretch wrapping machine shown in FIG. 1 and FIG. 2 is provided with a placing portion a for placing an article to be packaged on the front surface of the machine frame A, that is, in the front portion thereof, and the article to be packaged placed on the product placing section a is The conveyor 1 conveys it to the elevator 2 provided inside the machine frame A. A packaging portion b is provided above the elevator 2, and the film holding portions 3a and 3b are provided on both left and right sides of the packaging portion b, and a film feeder 6 that horizontally draws the film e from the film holding portions 3a and 3b. Clamps 7a, 7b, 8a, 8 for cutting and holding the front and rear and right and left of the drawn film e
b is provided. Further, left and right folding plates 4a and 4b and a rear folding plate 5 are arranged on the film holding portion 3.

The article to be packaged placed on the elevator 2 as described above is pushed up by the elevator e with respect to the film e stretched on the packaging part b, and the end portion of the film e in a stretched state is The left and right folding plates 4a,
After being folded into the bottom surface of the package by 4b and the rear folding plate 5, the discharge pusher 9 horizontally pushes the package to the discharge section c on the front side of the machine frame A, and the front side of the film e. Fold the edges to fold the film.

FIG. 4 shows a conveyor 1 and an elevator 2 which constitute a placing portion a for placing an article to be packaged. The conveyor 1 is configured by arranging four endless belts 11c in parallel between a drive roller 11a and a division roller 11b provided at a predetermined interval in the transport direction. The endless belts 11c are arranged at regular intervals in the width direction, a receiving member 13 for placing an article to be packaged is provided between the endless belts 11c at the start end, and the receiving members placed by these receiving members 13 are provided. The package is configured to be supported from below. In addition, a push piece 12 that comes into contact with the article to be packaged is attached to the outer circumference of each of the endless belts 11c so as to be aligned in a horizontal line. It is configured to be conveyed while being received by the piece 12. An optical sensor 15 is provided on one side of the conveyor 1 to detect the length, width and height of a packaged object moving on the conveyor 1 and direct it to a control means (not shown) described later. Output the detection information. Further, the control means selects the size of the film e based on the detection information.

The elevator 2 installed so as to be connected to the end portion of the conveyor 1 is made up of five support members 21 standing vertically at a predetermined interval.
The above-mentioned endless belts 1 each having the upper surface of 1 aligned flush with each other.
By inserting and arranging between 1c, the to-be-packaged goods conveyed by each conveyor 1 are received by the receiving surface comprised by each said support member 21. Also,
The elevator 2 supports the integrated support members 21 by an elevating mechanism (not shown) so as to move up and down between the end of the conveyor 1 at the descending position and the packaging unit b at the ascending position. Is configured.

As shown in FIGS. 2 and 5, holding portions 3a and 3b for the film e are provided immediately above the elevator 2 and at positions corresponding to both left and right sides of the packaging portion b.
In the stretch wrapping machine in this embodiment, two film rolls e1 and e2 having different sizes are separately arranged on the right and left sides of the machine frame A.
The film e pulled out from 2 is held by the holding portions 3a and 3b, respectively. Both holding parts 3a and 3b are constructed in exactly the same manner, and are installed in a state of facing both left and right side parts in the machine frame A. Since the holding portions 3a and 3b have exactly the same structure, the structure will be described based on the holding portion 3a on the right side.

As shown in FIG. 5, the holding portion 3a is mounted horizontally with respect to the machine frame A in a state where two holding plates 31 formed in a substantially comb-like plane are overlapped with each other with a slight gap. I support it. The film e drawn from the film roll e1 is inserted from the outside between the support plates 31 by bypassing the roll 32, and is held in a state of being drawn to the inner edge portion which is cut into a comb shape. Further, two guide shafts 35 are mounted and supported in parallel at a level slightly lower than the left and right holding portions 3a, 3b, with a gap somewhat larger than the width of the holding portions 3a, 3b. Guide shaft 35 described above
Is slidably supported by penetrating both ends of the feeder 6 and the left and right clamps 7a and 7b, so that the feeder 6 and the left and right clamps 7a and 7b are slid horizontally in the drawing direction of the film e, respectively. It is a guide to move.

The feeder 6 is driven by a drive mechanism (not shown) that uses a timing belt or the like to guide the guide shaft 35.
The film e is slidably moved in both the left and right directions along with, and selectively holds the film e held by either one of the holding portions 3a, 3b on the right side or the left side and pulls it out toward the center. The feeder 6 axially supports the support shaft 62 along the lower surface of the connecting member 61 that straddles between the left and right guide shafts 35.
A gripping plate 63 is integrally attached along and is swingably supported. That is, the film e is drawn out by the feeder 6 so as to cross the end portion of the conveyor 1. The holding plate 63 is formed by notching both left and right side edge portions in a comb-teeth shape, and the respective convex portions of these comb-teeth portions enter the corresponding gaps between the comb-teeth-shaped holding portions 3a and 3b. It is configured as follows.

The gripping plate 63 rotates like a seesaw to the right and left with the central support shaft 62 as a fulcrum, and contacts the right and left edges of the connecting member 61 to grip the film e. Further, anti-slip members 63a are attached to the upper surfaces of the convex portions of the grip plates 63, respectively, and the anti-slip members 63a and the connecting members 6 are connected with the rotation of the grip plates 63 as described above.
The film e is held between the lower surface and the lower surface. A rotating arm 62a is attached to one end of the support shaft 62 of the holding plate 63, and a drive cylinder 64 is connected to the tip of the rotating arm 62a.
The support shaft 62 and the grip plate 63 are selectively rotated rightward or leftward by the expansion and contraction operation of the.

The right clamp 7a holds the leading end of the film e held by the holding portion 3a on the right side of the feeder 6 and horizontally pulls it out, and then holds the right end of the film e pulled out. The film e is cut at the holding position, and a cutter 74 is provided together with the film e holding mechanism.

The right gromp 7a is slidably supported along the guide shaft 35 by inserting both guide shafts 35 into blocks 72a provided at both left and right ends of the connecting member 72, and at the same time, a timing belt is provided. A driving mechanism (not shown) utilizing the above, etc. slides along the guide shaft 35 in both the left and right directions similarly to the feeder 6. A support shaft 73 that is rotated by the same drive mechanism as the support shaft 62 of the feeder 6 is provided between the left and right blocks 72a.
Are installed and arranged along the lower surface of the connecting member 72.
The support plate 73 has a grip plate 7 bent into a crank shape in section.
The base end of No. 1 is attached, and the edge of the grip plate 71 on the tip side is rotatably supported toward the feeder 6. The holding plate 71
Rotates up and down with a support shaft 73 at the base end as a fulcrum, and contacts the edge portion of the connecting member 72 when ascending and holds the rear end portion of the film e pulled out by the film feeder 6. Also,
A cutter 74 is provided along the middle part of the grip plate 71, and as described above, the grip plate 71 grips the rear end of the film e, and at the same time, the rear side of the grip part of the film e is It is configured to be cut by a cutter 74.

The left clamp 7b grips the left end of the film e after the film e held by the holding part 3b on the left side is horizontally pulled out by the film feeder 6 and holds the gripping position. Is for cutting the film e with the same structure as the right clamp 7a,
It is installed on the left side of the film feeder 6 on the guide shaft 35.

As shown in FIGS. 1, 2 and 4, a front clamp 8a and a rear clamp 8b are provided at the front and rear portions of the same bell as the left and right clamps 7a and 7b placed in the machine frame A. The front and rear clamps 8a and 8b are, as described above, the film feeder 6 and either of the left and right clamps 7a and 7b.
It holds the front end and the rear end of the film e held between and. Each of the clamps 8a and 8b has a strip-shaped upper plate 82 extending parallel to the guide shaft 35 and the upper plate 8
2 is constituted by an elevating body 81 that comes into contact with the bottom from below, and both ends of these 81 and 82 are inserted into guide shafts 83 and 84 installed parallel to the conveyor 1 as shown in FIG. It is supported so that it can slide in any direction.

Elevating body 8 for the front and rear clamps 8a, 8b
1 is a mounting plate 8 that is installed across the guide shafts 83.
The cylinder rod 81b installed on the 1a moves up and down, and when the cylinder rod 81b rises, it abuts the lower surface of the upper plate 82 and holds the film e between the two 81 and 82. Further, the lifting body 81 and the upper plate 82 of both the front and rear clamps 8a and 8b move forward and backward in synchronization with each other by a drive mechanism such as a timing belt provided along the lateral sides of the guide shafts 83 and 84, respectively. Therefore, the film e pulled out from the left and right film rolls e1 or e2 is gripped at both left and right ends by the feeder 6 and either the left or right clamps 7a, 7b, and the front and rear ends by the front and rear clamps 8a, 8b. The rear end portion is gripped, and the four side portions are gripped and held horizontally below the packaging portion b.

The left and right clamps 7a in the packaging part b,
7b and the front and rear clamps 8a, 8b have left and right folding plates 4 for folding the left and right ends and the rear end of the film e in a state of being stretched by pushing up the object to be packaged to the bottom surface of the object to be packaged.
a, 4b and a rear folding plate 5 are installed. 1 to 3
As shown in, a pair of left and right folding plates 4a and 4b are provided. The left and right folding plates 4a and 4b are respectively the upper folding plate 4
2 and the lower folding plate 41 are superposed with a small gap therebetween. As shown in FIG. 3, the lower folding plate 41 of the left and right folding plates 4a, 4b is a strip-shaped plate extending in the front-rear direction, and two parallel attachments are supported at both front and rear ends thereof between the left and right side surfaces of the machine frame a. By inserting the guide shaft 43, the two folding plates 41 are configured to horizontally move from the left and right sides toward the center while maintaining the mutual parallelism.

Left and right folding plates 4a, 4b lower folding plate 4
The upper fold 42 provided on 1 is made of a strip-shaped plate similar to the lower fold plate 41, and its front and rear end portions are bent downward and fixed to the lower fold plate 41 by
The lower folding plate 41 is superposed and integrated with a small gap 45 therebetween. Further, a notch 44 is formed on the inner edge of the upper folding plate 42. The notch 44 is formed so that the width of the notch 44 increases in a taper shape from the front side to the rear side of the upper folding plate 42. According to the planar shape of the notch 44, the folding amount of the film e in the upper folding plate 42 is deep on the front side and shallow on the rear side. The notch 44 described above takes into consideration catching that occurs when the film e is folded and securing of the film adhesive surface, but the description thereof will be given later.

A rear folding plate 5 extending in the left-right width direction is fitted in a small gap 45 between the folding plates 41 and 42 on both upper and lower stages of the left and right folding plates 4a and 4b. The rear folding plate 5 is horizontally supported by inserting the left and right ends into a guide shaft 46 that is attached and supported along the outer sides of the left and right folding plates 4a and 4b, and is small between the folding plates 41 and 42 in both upper and lower stages. It slides back and forth along the gap 45. The drive of the rear folding plate 5 and the left and right folding plates 4a and 4b is performed by driving the respective guide shafts 43,
A drive mechanism (not shown) including a drive belt and the like provided along 46 is used.

A discharge pusher 9 is provided on the rear folding plate 5. The discharge pusher 9 is the rear folding plate 5.
Is configured to move horizontally from the rear side to the front side on the upper side of the film e, and the wrapping portion b has finished the folding of the left and right end portions and the rear end portion of the film e. Push it horizontally toward c. In the stretch wrapping machine configured as described above, the conveyor 1, the elevator 2, the film feeder 6, the left and right clamps 7a and 7b, the front and rear clamps 8 are provided.
The operations of the a and 8b, the left and right folding plates 4a and 4b, the rear folding plate 5, and the discharge pusher 9 are controlled by a control unit (not shown) configured by a microcomputer or the like. For example, the time chart of FIG. As described above, by activating each of the drive units by a predetermined imming, the article to be packaged placed on the placing section a5 is wrapped along a predetermined operation process.

Next, the operation of the above stretch wrapping machine will be described with reference to the wrapping process shown in FIGS. 6 to 20. still,
The object to be packaged f shown in this embodiment is in a state in which food or the like is placed on the tray. The operator places the article to be packaged f on the placing portion a protruding to the front of the packaging machine. The article to be packaged f placed on the receiving member 13 constituting the placing part a is pushed by the pushing piece 12 attached to the endless belt 1 of the operating conveyor 1 and pushed out horizontally, and the endless Belt 11
It is carried on top of the elevator c and is carried onto the elevator 2 (FIG. 6).
When the packaged object f is conveyed on the conveyor 1 as described above, the sensor 15 provided on one side of the conveyor 1 measures the size of the packaged object f in the length, width and height, and a detection signal thereof. To a control unit (not shown). Further, the control unit selects the films e1 and e2 for drawing out the film e, that is, the film size based on the dimension information of the packaged object f by the sensor.

At the same time, the feeder 6 moves toward the holding portion 3b in order to hold the tip of the selected film e2 (FIG. 7). In this explanation, the left film e
When 2 is selected but the right side film e1 is selected, the feeder 6 is moved toward the right side holding portion 3a as shown in FIG. The feeder 6 that has moved to the left end grips the end portion of the film e held by the holding portion 3b and pulls it toward the center (FIG. 10). When the end of the film e is pulled out to the center by the feeder 6,
The left clamp 7b moves along the guide shaft 35 and the holding portion 3 on the left side.
Move to the front of b (FIG. 11). The left clamp 7b moved to the front of the holding portion 3b is a film e that is pulled out horizontally.
Clamp the left end of the (Fig. 12). Simultaneously with the clamping by the left clamp 7b, the left end of the film e is cut by the cutter 74.

Next, the feeder 6 for holding the left and right sides of the cut film e and the left clamp 7b move further to the right, and the held film e is aligned with the center of the packaging part b (FIG. 13). . At this time, the feeder 6 and the left clamp 7b are stopped at a wider interval than when the film e was first gripped, and the film e thus gripped is pulled in the left-right direction to give an appropriate tension. Further, both front and rear clamps 8a and 8b are actuated to clamp both front and rear sides of the film e (FIG. 14). As a result, the cutting film e is clamped on all four sides. Then, the elevator 2 on which the article to be packaged f is placed moves up and is pushed up toward the film e stretched in the packaging section b (FIGS. 15 and 16). In addition, as for the to-be-packaged object f mounted on the elevator 2, the bottom surface of the tray has the left and right folding plates 4a,
The upper folding plate 42 of 4b is positioned at substantially the same level.

Next, the left and right folding plates 4a and 4b are actuated, and the film e in a state where the object f to be packaged is pushed up by the lift of the elevator 2 is horizontally actuated from both left and right sides, and the film e The left and right ends are folded into the bottom surface of the object to be packaged f. Left and right folding plates 4a, 4b upper folding plate 42
Together with the folding of the film e, it enters below the article to be packaged f on the elevator 2 and supports the article to be packaged f from below instead of the elevator 2. Further, the elevator 2 has an upper folding plate 4
At the same time that the article to be packaged 2 is supported by 2, the descent is started, and the next article to be packaged f to be conveyed is awaited at the end of the conveyor 1 (FIG. 17). The timing of lowering the elevator 2 is set from the moment when the packaged object f is supported by the left and right folding plates 4a and 4b to the time before the rear folding plate 5 is positioned directly below the packaged object f, The operation control is performed by the control unit (not shown) as described above.

Immediately after that, the rear folding plate 5 provided between the upper and lower folding plates 41, 42 of the left and right folding plates 4a, 4b is actuated to fold both left and right sides into the bottom surface of the object to be packaged f. Fold the film e from back to front, at that time,
The rear clamp 8b, the left clamp 7b and the film feeder 6 open the rear end portion and the left and right end portions of the film e held by the rear clamp 8b (FIG. 18). At the time of the folding operation shown in FIG. 17, the inner edge of the upper folding plate 42 is the lower folding plate 4.
It is configured so as to be located outside the inner edge of 1.
As a result, the folding amount of the film e by the upper folding plate 42 toward the center of the packaging portion b becomes shallow at the upper folding plate 42 and deep at the lower folding plate 41, whereby the rear folding plate 5 As a result, the gathering of the end portions of the film e that occurs when the film e is folded to the front side can be prevented from being caught by the upper folding plate 42 when the packaged object f is discharged.

Further, according to the planar shape of the notch 44 which spreads in a taper shape from the front to the rear, the folding amount of the film e in the upper folding plate 42 becomes deep on the front side and shallow on the rear side. As a result, the width of the folding margin at the time of folding the end portion of the film e by the rear folding plate 5 can be ensured to be wide, and the adhesion area at the folding margin portion can be sufficiently secured. As described above, after the rear folding plate 5 has moved to the front ends of the left and right folding plates 4a and 4b, the discharge pusher 9 operates and the left and right folding plates 4
The object f to be packaged on a and 4b is pushed horizontally toward the front discharge part c, and the front end part of the film e held by the front clamp 8a is released during the process (FIG. 19). . As a result, the left and right ends and the front and rear ends of the film e are folded back by 180 ° to the bottom surface of the packaged object f and attached to the bottom surface of the packaged object f.

An operator picks up the object to be packaged f placed in the discharge section c after the folding, and presses the bottom surface portion against the heat seal section d to heat and bond it. In the above embodiment, the upper and lower folding plates 41, 42 of the left and right folding plates 4a, 4b are integrally connected and fixed, but the upper folding plate and the lower folding plate are separated from each other. It may be supported and actuated separately. In addition, the upper folding plate 4 of the above embodiment
By forming a tapered notch 44 in a and 4b,
Although the film e is configured to be folded at the rear side shallowly, the upper folding plate of the left and right folding plates is pivotally supported at the front end of the plate and is supported so as to be rotated along a horizontal plane so that the folding operation is performed. The rear side of the film e may be shallowly folded in the same manner as in the above embodiment.

[0034]

As described above, the present invention is configured such that the left and right folding plates are stacked on each other and the left and right folding plates of both upper and lower stages are stacked, and the rear folding plate moves between the left and right folding plates of both upper and lower stages. Therefore, simultaneously with the folding operation of the left and right folding plates, the items to be packaged on the elevator are supported by the upper left and right folding plates, and the elevator descent starts immediately without waiting for the folding operation by the rear folding plate as in the conventional one, and then Move toward the packaging process. As a result, the processing speed of the packaging speed can be improved. Moreover, since the rear folding plate does not hit the object to be packaged, it can be folded smoothly.

According to a second aspect of the present invention, the film folding amount by the left and right folding plates toward the center of the bottom surface of the package is shallow at the upper and right folding plates and deep at the lower left and right folding plates. Can effectively prevent the left and right folding plates at the upper stage of the film end portion folded to the front side by the rear folding plate from being caught at the time of discharging the object to be packaged.

Further, as in the third aspect, the folding amount in the left and right folding plates of the upper stage is deep at the front side of the packaged object,
In the case of shallower ones on the rear side, the amount of folding by the upper left and right folding plates becomes wider on the rear side of the bottom surface of the packaged item, so it is sufficient to secure a wide folding margin when folding by the rear folding plate. The adhesive area can be secured, and peeling of the film after folding can be prevented.

Further, in the stretch wrapping machine in which the upper and lower folding plates are integrally connected, the structure of the left and right side plates formed by stacking the upper and lower folding plates is rationalized. It is possible to simplify, reduce the occurrence of failures, and reduce the cost.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a stretch wrapping machine embodying the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a perspective view showing left and right folding plates and a rear folding plate of the packaging unit.

FIG. 4 is a perspective view showing a conveyor and an elevator section.

FIG. 5 is a perspective view showing a film feeder and left and right clamps.

FIG. 6 is a side view showing a conveyor unit on which an article to be packaged is placed.

FIG. 7 is a vertical sectional front view showing a left holding portion.

FIG. 8 is a vertical cross-sectional front view showing a right holding portion.

FIG. 9 is a vertical cross-sectional front view of the left holding portion showing a state where the film end portion is held by the film feeder.

FIG. 10 is a vertical cross-sectional front view of a holding portion showing a state in which a film end portion is pulled out.

FIG. 11 is a vertical cross-sectional front view showing a state where the film is pulled out to the packaging unit by the film feeder.

FIG. 12 is a vertical sectional front view showing a state in which the left end of the film is cut by the left clamp.

FIG. 13 is a vertical cross-sectional front view showing a state in which the film held by the film feeder and the left clamp is centered in the packaging unit.

FIG. 14 is a vertical sectional front view showing a state where the rear end portion of the film is held by a rear clamp.

FIG. 15 is a vertical cross-sectional front view showing a state in which the object to be packaged is pushed up with respect to the film spread on the packaging section.

FIG. 16 is a vertical sectional side view of the same state.

FIG. 17 is a vertical sectional front view showing a state in which the left and right folding plates are operated.

FIG. 18 is a vertical cross-sectional side view showing a state where the rear folding plate is operated.

FIG. 19 is a vertical cross-sectional side view showing a state in which an object to be packaged is discharged by a discharge pusher.

FIG. 20 is a time chart showing one stroke of each operation unit.

[Explanation of symbols]

 A ... Machine frame a ... Placement part b ... Packaging part c ... Discharge part e ... Film 1 ... Conveyor 2 ... Elevator 3a, 3b ... Holding part 4a, 4b ... Left and right folding plate 5 ... Rear folding plate 6 ... Film feeder 7a, 7b ... Left and right clamp 8a, 8b ... Front and rear clamp 9 ... Discharge clamp 41 ... Lower stage folding plate 42 ... Upper folding plate

Claims (4)

[Claims] 1. A packaged object placed on an elevator is pushed up against a film horizontally spread in a packaging section, and the left and right and rear sides of the film are folded into a bottom surface of the packaged item by folding plates. After that, in a stretch wrapping machine that folds the front side of the film while discharging the object to be packaged, it is provided with left and right folding plates that fold the film left and right, and the left and right folding plates are respectively the upper folding plate and the lower folding plate. A folding plate, the rear folding plate is inserted between the upper and lower folding plates of the left and right folding plates to support the front and rear movably, and the rear folding plate after the folding operation of the left and right folding plates is started. A stretch wrapping machine that is equipped with means for lowering the elevator before it is folded. 2. The folding amount of the film by the left and right folding plates toward the center of the bottom surface of the article to be packaged is shallow in the upper folding plate and deep in the lower folding plate. Stretch wrapping machine as described. 3. The stretch wrapping machine according to claim 1, wherein the folding amount of the upper folding plate is deep on the front side of the article to be packaged and shallow on the rear side. 4. The stretch wrapping machine according to claim 1, wherein the upper and lower folding plates are integrally connected.