JP2762961B2 - Stretch film packaging machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretch film wrapping machine, and more particularly, to a stretch film wrapping machine having a means for suppressing a movement of a pressing member for pressing an upper surface of a product to be wrapped.

[0002]

2. Description of the Related Art In a conventional stretch film wrapping machine, when a film end is folded under a product, a pressing plate 23 for holding down the product by its own weight is used to prevent the product from moving due to the operation of the folding plate and from being unable to be packed well. However, one end thereof is provided directly above the elevator head with the one end supported to be rotatable in the vertical direction.
(See Japanese Utility Model Laid-Open No. 2-141304)

[0003]

The pressing plate 23 of the above-mentioned conventional stretch film packaging machine is normally stopped at the lowermost position. When the product 24 in the pushing-up process by the elevator head is pushed up by contact, the product 24 is held down by its own weight, and when the product 24 is discharged by the discharge pusher, it loses its support and naturally descends to the lowermost position. Was. However, in such a structure, even after the folding of the film end by the folding plate is completed, the pressing member 23 still keeps pressing the product 24. Therefore, when the product is discharged, particularly immediately before the product 24 is completely discharged, if the weight of the holding member 23 is applied only to the rear end 26 of the product, the front portion 25 of the product rises, and the product is not discharged reliably. 24 overturned.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to prevent the weight of a holding member from being applied to a product when the product is discharged, thereby stably discharging the product. The present invention is to provide a stretch film packaging machine capable of performing the above.

[0005]

The technical means taken to achieve the above object is to convey a product from a carry-in portion to a portion below a packaging portion and push the product up on a film stretched horizontally in the packaging portion. In a stretch film wrapping machine in which the film end is folded under the product while pressing the upper surface of the product with a vertically movable pressing member, the downward movement of the pressing member is suppressed just before the discharge of the product is started, When the discharge is completed, a suppressing means for releasing the pressing member from the suppressed state is provided. Further, in addition to the above, a restraining means that restrains the movement of the pressing member when the elevator head reaches the top dead center and releases the pressing member from the restrained state when the folding of the film end is completed.

[0006] Electromagnetic brakes,
Alternatively, other hydraulic or pneumatic brakes can be used. Further, as for the timing to start the suppression, it is preferable to detect a timing pulse indicating that the elevator head pushing up the product has reached the top dead center.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings, in which a film clamp is constituted by a pair of upper and lower elastic belts and a clamp plate for pressing one elastic belt against the other belt. I do. The stretch film wrapping machine shown in FIGS. 1 and 2 is provided with a product placing portion a in front of a machine frame A, and a packaged object placed on the product placing portion a is conveyed on a conveyor B.
To the elevator 1 provided inside the machine frame A.
A packaging part b is provided above the elevator 1, and a film holding means C for holding a leading end of a film 3 fed from a film roll 2 set on a side of the packaging part b is provided. The film feeding means D for conveying the film to the film holding means C is arranged close to the tip of the film holding means C, and a cutter E is arranged between the two. Above the film feed means D, left and right folding plates 4a and 4b, a rear folding plate 5 and a discharge pusher 6 are arranged above the rear folding plate. Further, a holding member F is disposed at a position above the packaging section b and directly above the elevator 1.

[0008] Therefore, the article to be packaged placed on the elevator 1 is pushed up against the film 3 spread on the above-mentioned wrapping section b by raising the elevator, and the end of the stretched film is moved right and left. The front end of the film 3 is folded by pushing the packaged object horizontally toward the heat seal portion (not shown) on the front side of the machine frame A by the folding plates 4a and 4b and the rear folding plate 5. Make a fold. Then, the end portion of the film folded into the bottom surface of the article to be packaged by the heat sealing section is heat sealed to complete the packaging.

The film holding means C comprises a film receiving member 7 and a pressing member 8, and moves the leading end of the film sandwiched by both to a starting end of a film feeding means D to be described later. The film feeding means D includes:
Upper and lower pair of conveyor belts 9a, 9b and clamp plate 1
Two units composed of Oa, 10b, and 10c are arranged before and after the packaging part b. One unit is fixed, and the other unit is a guide rod 11
The units a and 11b are movably supported via connecting members 12a and 12b so that the distance between the two units can be adjusted.

The holding member F is a flat holding member 13.
The link mechanism is constituted by the ends of two link arms 15a and 15b axially supported by the bracket 14 attached to the machine casing A in parallel with each other to support the pressing member 13, thereby forming the pressing member. 13 can move up and down while maintaining a substantially horizontal state. The shaft 16a on the bracket side of one link arm 15a is connected to the restraining means H, and this shaft 16a is
The other link arm 15b is also connected to the bracket-side shaft 16b via the belts 18 and 17a.

Next, the operation of each part relating to packaging will be described.
Control of each part of the packaging machine is performed by a cam 19 for driving the elevator 1.
, And one cycle of packaging is performed when the cam 19 makes one rotation. The rotation angle of the cam 19 is detected by counting pulses from a rotary encoder 21 attached to the cam shaft 20 and detecting the count value. That is, the elevator 1 is moved up and down in the latter half of one packaging cycle, and in the first half of one packaging cycle, the conveyed object is carried in by the conveyor B, the film is pulled out by the film feeding means, centering, and pre-stretching are performed.

Next, the operation of the pressing member F will be described. FIG. 3A shows a state in which the holding member 13 is standing by in a state where the holding member 13 can freely move up and down, and shows a state immediately after the product 22 on the elevator starts pushing up. FIG. 3B shows a state where the elevator 1 has reached the top dead center. When the pressing member 13 is pushed up to the upper surface of the product 22 and rises, and when the pulse from the rotary encoder 21 detects that the elevator 1 has reached the top dead center, the restraining means H operates to activate the link arm 15.
The shafts 16a and 16b of the shafts 15a and 15b are prevented from rotating, so that downward movement is suppressed. And product 22
Is folded right and left while being held between the lower surface of the holding member 13 and the elevator head 1. Here, the holding member 13 is made very light, and does not hurt the product 22 even if the product 22 is pushed up. Then, since the vertical movement is suppressed at the time of folding, the product 22 can be firmly pressed and folded well. FIG. 3 (c)
This shows a state in which the right and left folding and the rear folding are completed, and the discharge pusher 6 is operated to discharge the product 22. At this time, the pressing member 13 maintains the state in which the downward movement is suppressed by the operation of the suppressing means H even when the product 22 is lost on the lower surface. FIG. 3D shows a state in which the operation of the discharge pusher 6 has been completed. Since the operation of the discharge pusher 6 is performed in relation to the position of the elevator head 1, the completion of the operation of the discharge pusher 6 can be detected by the pulse from the rotary encoder 21 described above. The operation of H is released, and the holding member 13 moves down to the standby position by its own weight.

In the embodiment of the present invention described above, the timing when the restraining means H of the holding member 13 is activated is when the elevator 1 reaches the top dead center. However, the present invention is not limited to this mode and the elevator is not limited to this mode. It is sufficient that the product 22 is moved from the time when 1 reaches the top dead center to the time when the discharge pusher 6 is actuated and the center of the product 22 passes the tip of the holding member 13.
Further, the timing for releasing the inhibiting means H is not limited to the embodiment of the present invention, and the product 22 may be released when the discharge pusher 6 is operated.
This may be performed after the rear end of the elevator 1 passes through the front end of the holding member 13 and before the elevator 1 pushing up the next product 22 reaches the top dead center. Further, these controls are not limited to electric controls, and may be mechanical controls linked to the main power. Further, the operation mechanism of the pressing member 13 is not limited to the horizontal movement method described above, but may be a method based on rotation. Further, a product feeding belt instead of the discharge pusher 6 may be worn. Further, when the period in which the movement of the pressing member 13 is suppressed is set to the period in which the edge of the film is folded,
At least the product 22 can be folded well without damage.

[0014]

In the stretch film wrapping machine according to the present invention, the holding member cannot be lowered until the end of the discharging of the goods, so that the rear end of the goods during the discharging step is not pressed by its own weight. . As a result, the product is reliably discharged, so that the operation rate of the packaging machine is improved, and the product is not overturned and cannot be sold. According to the configuration described in claim 2, since the movement of the pressing member is suppressed when the film is folded, the pressing member can be lightened, and the product can be packed well without being damaged by the weight of the pressing member when the product is pushed up. In addition, in the case of the configuration described in claim 3, since existing electric components can be used, the present invention can be implemented at low cost without adding new electric components.

[Brief description of the drawings]

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

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

FIG. 3 is a longitudinal sectional side view showing an operation process of a pressing member.

FIG. 4 is an exploded perspective view showing a configuration of a pressing member.

FIG. 5 is a vertical sectional side view showing a conventional example.

[Explanation of symbols]

 A: Machine frame B: Conveyor C: Film holding means D: Film feeding means E: Cutter F: Pressing member G: Discharge part H: Suppressing means

Claims (3)

(57) [Claims] 1. A product is conveyed from a carry-in portion to a portion below a packaging portion, the product is pushed up on a film stretched horizontally in the packaging portion, and a film end is pressed while holding an upper surface of the product by a vertically movable pressing member. In the stretch film wrapping machine which folds under the above, the movement of the pressing member is suppressed between the time when the elevator head reaches the top dead center and immediately before the discharge of the product starts, and when the discharge of the product is completed, the pressing member is restrained. A stretch film packaging machine, comprising a restraining means for releasing from a state. 2. A product is conveyed from a carry-in portion to a portion below a packaging portion, the product is pushed up on a film stretched horizontally in the packaging portion, and a film end is pressed while a top surface of the product is pressed by a vertically movable pressing member. A stretch film wrapping machine that folds under the film, wherein a restraining means is provided for restraining the movement of the pressing member when the elevator head reaches the top dead center, and releasing the pressing member from the restrained state when the folding of the film end is completed. A stretch film packaging machine. 3. The method according to claim 1, wherein the suppression is started when a timing pulse indicating that the elevator head pushing up the commodity has reached a top dead center is detected. Stretch film packaging machine.