JPH1191708A - Automatic wrapping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent film from being torn, by carrying out a film stretching operation in which, in the case an amount of stretch calculated according to the size of an item being wrapped is larger than the preset largest amount of stretch, the largest amount of stretch is used as the upper limit. SOLUTION: In an automatic wrapping device 1 for wrapping by stretching stretchable film in the direction of its width by means of a side gripper 62 and interfolding it on the outside of the bottom of a tray 17, first, the tray 17 is supplied onto a lifter 67 while the size of the tray is detected by a sensor array. Then, the device calculates, according to a film-draw quantitative arithmetic expression determined in advance, an amount of film draw and an amount of film stretch which matches the size of the tray 17, and it judges whether or not it is equal to or smaller than the largest amount of film stretch. If the calculated amount of stretch is larger than the largest amount of stretch, the devices processes so that the largest amount of stretch is set as the actual amount of stretch. This prevents the wrapping film from being overstretched and torn as a result of it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically packing a packaged object such as a dish-shaped container (tray) containing foods to be sold at a department store or a supermarket food store, using a film. The present invention relates to an automatic packaging device such as a tray packaging device.

[0002]

2. Description of the Related Art A tray packaging apparatus includes a tray loading section, a film supply section, a tray packaging section, and a tray transport section. The tray loading section consisting of a belt conveyor, etc.
The tray containing the articles supplied thereto is carried into the tray packaging section, and the film supply section feeds out the stretchable transparent film that can be stretched and supplies it to the tray packaging section.

[0003] The tray wrapping section feeds the film fed from the film supply section to the tray conveyed there.
The tray is stretched and folded into the bottom outer surface of the tray from both sides in the width direction and both sides in the longitudinal direction, and the tray is wrapped, and the wrapped tray is delivered to the tray discharge section.

The stretching of the film to both sides in the width direction is performed by using a side gripper which is moved at a constant speed while gripping a side edge of the film. At this time, the film feeding end is gripped by a front gripper that pulls out the film, and the film feeding source side is pressed by a film holding unit of the film supply unit so that the film is not dragged out. Stretching by the side gripper is performed in a state where it is held so as not to move. Then, the tray carry-out unit carries out the packed tray outside the tray packaging device.

[0005] Further, the tray packaging device includes, in addition to an input section for inputting designated values for various settings, a detecting means for detecting the size of the tray conveyed in the tray loading section;
Control means for performing a packaging operation by stretching the film based on the execution of the various settings and the detected tray size.

The control means calculates a film stretching amount based on the detected tray size in accordance with a predetermined formula, and grips a side edge of the film to move the film in the width direction. By controlling the amount of movement of the side gripper in accordance with the result of the calculation, the film is stretched from both sides in the width direction, and subsequently, packaging is performed.

[0007]

By the way, it is known that a film is difficult to be stretched at a lower use temperature.
The temperature condition at which the stretchable packaging film currently provided can exhibit its properties is, for example, (23 ± 5) ° C., while the temperature condition of the tray packaging device is (5-3).
5) It is ° C. Therefore, if the tray packaging device is, for example, 5 ° C
If the film is used under such a low temperature condition, there is a problem in that the film is likely to be broken when stretched, resulting in poor packaging.

Further, even if the temperature condition is proper, FIG.
As shown in (A), when packaging a tray 17 in which fruits and vegetables f, such as tomatoes and apples, which are curled, protrude more than the upper opening of the tray 17, the stretched film F is used. There is a risk of tearing.

That is, the stretching amount of the film is determined according to the calculation result based on the size of the tray 17 detected by the detecting means as described above. The calculation is basically (W × a) + (L × b) + (H ×
c) It is performed according to the formula of + d. In this formula, W is the maximum width dimension extending in the direction orthogonal to the loading direction of the tray 17 to be loaded at the loading section, L is the maximum length dimension of the tray 17 extending in the loading direction, and H is the fruit and vegetable f
It is the maximum height including articles such as. Similarly, in the above formulas, a, b, and c are designated values (unit%) determined by testing and packaging hundreds of trays supplied to the market, respectively, and d is determined based on the same test packaging. Is a constant.

[0010] The stretching amount of the film F calculated by such an equation is basically determined by the length defined by the outer bottom surface of the tray 17 in FIG. The values are corrected using a, b, and c and a constant d. However, since it is impossible that the stored articles such as fruits and vegetables f protruding from the tray 17 have the same size as the opening dimension of the tray 17, in the actual packaging, the tray 17 is closed by the upper opening edges on both sides in the width direction of the tray 17. As shown in FIG. 10 (B), the film portion extending over the protruding fruits and vegetables f is sloping to the shortest distance to package the fruits and vegetables f. When packaging the tray 17 in which the stored articles such as the fruits and vegetables f are protruded more than the upper opening of the tray 17 in this manner, the above formula is used to calculate the amount of the film F that is actually required. In some cases, the calculated amount of enlargement becomes extremely large.

Even in such a case, in a conventional tray packaging apparatus that stretches a film by the calculated amount of stretching and wraps the film, the film is stretched excessively, and as a result, the film is broken and the packaging failure occurs. May occur.

Further, in the conventional tray packaging apparatus, the film is stretched in the width direction by moving the side gripper at a constant speed as described above. Therefore, when the calculated amount of stretching is large, the stretching speed is increased. Tend to be too strong, which can cause the stretched film to tear.
In addition, if the stretching speed is reduced in consideration of this point, the film is stretched slowly even when the calculated stretching amount is small, so that the packaging efficiency is reduced when packaging trays of various sizes. Will be forced to.

Further, in the conventional tray packaging apparatus, as described above, the film is fed at a constant speed by the side gripper in a state where the unwinding side of the film is pressed by the film presser so as not to move. As described above, the larger the amount of stretching calculated, the more likely it is to apply an excessive force to the film, so that the stretched film may be broken.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an automatic wrapping apparatus which is capable of wrapping a film, which is stretched in the width direction and wraps a packaged object, while preventing the film from being broken.

[0015]

According to a first aspect of the present invention, there is provided a film supply unit, a packaging unit that stretches a film fed from the supply unit and wraps an object to be packaged, and the package unit includes the film supply unit. A carry-in unit for supplying the package, a detecting unit provided in the carry-in unit and configured to detect a size of the package to be supplied to the packaging unit, and a size of the package detected by the detecting unit It is assumed that the automatic packaging apparatus includes a control unit for calculating a stretching amount of the film according to the above and performing a film stretching operation.

[0016] In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that the control means determines that the calculated stretching amount is larger than a preset maximum stretching amount.
It is characterized in that a film stretching operation with the maximum stretching amount as an upper limit is performed in the packaging section.

According to the first aspect of the present invention, the control means calculates a film stretching amount based on the detected size of the packaged object, and when the calculated amount is larger than a preset maximum stretching amount. In addition, the amount of stretching in the width direction of the film is limited to the maximum amount of stretching, and the packaging operation in the packaging unit is controlled. As a result, the film is no longer stretched outright in accordance with the calculated stretch amount. Such stretching restrictions are imposed, for example, in the case where articles contained in the tray are to be packaged with articles that protrude more than the upper opening of the tray, and such articles are already described in the related art section. As described above, since the stretching size actually required is smaller than the calculated stretching amount, even if the film is stretched at the maximum stretching amount of a value smaller than the calculated stretching amount, In fact, it can be packaged without hindrance.

Similarly, in order to solve the above-mentioned problem, the invention according to claim 2 is based on the same premise as that of the invention according to claim 1, and the control means controls the expansion speed in at least two stages of the preset speed. , A stretching speed at a stage corresponding to the calculated stretching amount is selected, and the film stretching operation in the packaging unit is performed at the selected stretching speed.

In the second aspect of the present invention, the control means calculates a film stretching amount based on the detected size of the packaged object, and selects a stretching speed according to the calculated value. This selection is to select a stretching speed of a stage corresponding to the calculated stretching amount from two or more stretching speeds set in advance. Is performed in the width direction. Accordingly, the film is stretched at a low stretching speed when the stretching amount is larger than the reference value forming the boundary of the step, and at a high stretching speed when the stretching amount is smaller than the reference value. Therefore, the film stretched according to the size of the article to be packaged can be stretched and packaged at an appropriate speed according to the stretched amount.

According to a third aspect of the present invention, there is provided a film supply unit having a film press for feeding the film and pressing the fed film so as not to move, and the film is fed from the film supply unit by gripping a leading edge of the film. A front gripper that pulls out the film; and a side gripper that grips a side edge of the film drawn out by the gripper and stretches the film in the width direction. A packaging section for packaging the package, a carry-in section for supplying the packaged article to the package section, and a detection means provided in the carry-in section and configured to detect a size of the packaged article supplied to the packaging section Calculating a stretching amount of the film according to the size of the packaged object detected by the detecting means, and performing a film stretching operation. It assumes automatic packaging apparatus comprising a that control means.

In order to solve the above-mentioned problem, the invention according to claim 3 is characterized in that when the control means stretches the film in the width direction by the side gripper, the control means adjusts the film in accordance with the calculated stretch amount. It is characterized in that the pressing operation of the film presser is changed at a timing later than the starting point of the stretching as the amount increases.

According to the third aspect of the present invention, when the film is stretched in the width direction, the film retainer for preventing the film from being pulled out from the film supply portion side is a film that has already been drawn at the start of the film stretching. However, the control means operates to press the film after the start of the stretching. In this case, the control means performs the pressing operation of the film presser at a timing delayed from the start time of the stretching as the amount is larger according to the stretching amount calculated based on the size of the packaged object. Control. Therefore, when the stretching amount of the film is large, the film is pulled out until a certain point in time when the stretching is started, and the film is stretched while suppressing the excessive stretching force from acting on the film. Can be stretched and packaged. Further, when the stretch amount of the film is small, the film can be packed so as to prevent the film from being pulled out at an early stage, thereby preventing the stretching force from lowering.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

The tray packaging apparatus 1 according to the first embodiment as an automatic packaging apparatus shown in the perspective view of FIG. 1 has an operation panel 2 as an input unit as shown in FIGS.
Loading section 11 serving as tray loading means, packaging section 12 serving as tray packaging means, and loading section 13 serving as tray loading means
, A film supply unit 14, a horizontal sensor array 31 as a detecting unit, a vertical sensor array 32, and a control unit 71 shown in FIG.

As shown in FIG. 1, an operation panel 2 is mounted on the upper part of the front frame 1a of the tray packaging device 1 so as to be exposed on the front surface thereof. The panel 2 is provided with a large number of operation buttons 3 for performing various operational instructions and various settings for the tray packaging device 1,
A display unit 4 such as a liquid crystal display device is provided. Display unit 4
For example, the setting content is displayed at the time of setting, and the number of packages and the like are displayed during packaging. In FIG. 1, reference numeral 5 denotes a cover which is detachably provided to cover the packaging unit 12 from above.

The carry-in section 11 is horizontally disposed so as to pass through a tray carry-in port 1b formed in the front frame 1a of the tray packaging apparatus 1 shown in FIG. This loading unit 1
1 has a plurality of belts 16a which are arranged at intervals in the left-right direction (width direction) and synchronously rotated by the power of the stepping motor 15, as shown in FIGS. It has a carry-in belt conveyor 16, the front part of which is located outside the front side of the front frame 1a, and the rear part of which is the front frame 1a and the rear frame 1c
(See FIG. 3).

The front portion of the carry-in section 11 is used as a tray supply section, in which a tray 1 containing an article A to be packaged, such as fresh food or the like, as shown in FIG.
7 is supplied by the user. The tray 17 is a shallow or deep dish with an open upper surface.

A wall which the carry-in section 11 has at one end in the width direction, for example, a vertical wall 35 on the right side when viewed from the front is a wall serving as a reference when the tray 17 is supplied.
As shown in FIG. 5, a supply switch 36 as a start switch is provided. The switch 36 is a pressing type and has a considerably large area, and the supply switch 36 is turned on when the side surface of the tray 17 is pressed against it. Thereby, the motor 1
5 is driven, the carry-in belt conveyor 16 starts the carrying operation, and carries the tray 17 toward the packaging unit 12. The rear part of the loading section 11 is the front and rear frames 1a,
1c, and the tray 17 loaded by the loading unit 11 is located in the packaging unit 12.
Is supplied.

The wrapping section 12 holds the tray 17 positioned in the wrapping section 12 upward from the rear of the loading section 11 and holds a film supply section 14 provided below the unloading section 13 (FIG. 4). The transparent stretchable film F which can be stretched out by drawing out from the tray 17 is drawn out based on the measured size of the tray 17 and stretched in the width direction. In addition, the tray 17 is automatically packaged together with the articles A by folding the tray 17 from both sides in the longitudinal direction into the outer surface of the bottom of the tray 17.

The wrapping unit 12 for performing the automatic wrapping operation is well known, but will be described with reference to FIGS. Between the front and rear frames 1a and 1c of the tray packaging device 1, a front gripper 61 which is pulled out with the leading edge of the film F interposed therebetween.
And a pair of side grippers 62 for individually gripping the width side edges of the drawn film F and stretching the film F in the width direction. Front gripper 61
The guide rail 6 is moved in the
A grip rubber (not shown) for preventing the film F from being pulled out when the gripped film F is pulled is provided on the inner surface of the film gripper 61a which is opened and closed by the gripper 61. ) Is provided.

The pair of side grippers 62 includes a drive mechanism 6
4, the film F is moved in a direction perpendicular to the drawing path of the film F toward each other and in a direction away from each other. The drive mechanism 64 has a stepping motor (not shown) as a drive source. Both grippers 6
Reference numeral 2 denotes a plurality of film grip portions 62a which are opened and closed, and are provided side by side. A grip is provided on at least one inner surface of each of the grip portions 62a to prevent the film F from being pulled out when the sandwiched film F is stretched. Rubbers 65 are provided respectively. In FIG. 5, reference numeral 66 denotes a lifter including an elevating body 67, a movable supporting body 68 supported by the elevating body 67, and a driving mechanism 69 for elevating the elevating body 67.
And is disposed at the rear of the carry-in section 11. The drive mechanism 69 has a stepping motor (not shown) as a drive source. The movable support 68 is maintained in a self-standing state by the force of a normal spring and tilts when pushed from the side by the side gripper 62 so as not to hinder the folding operation of the film F by the side gripper 62. .

The film F is withdrawn by the reciprocating movement of the front gripper 61 so as to be positioned above the movable support 68. Next, at the stretching start position, the edges on both sides in the width direction of the film F are separated by a pair of side grippers 62. After the sheet F is sandwiched, the drawn film F is preliminarily stretched by retreating the side grippers 61 as shown in FIG. In this state, the movable support 68
The tray 17 carried in is lifted by the lifting operation of the lifter 66, and is pushed up while further extending the drawn film F. Next, the pair of side grippers 62 approach each other and enter the lower side of the bottom outer surface of the tray 17 to fold the film F into the bottom outer surface of the tray 17 from both sides in the width direction, and then release the grip of the film F. It retreats away from each other and returns to its initial position. Thereafter, the front gripper 61 is moved in the direction of the unloading section 13, enters the lower side of the bottom outer surface of the tray 17, folds the film F from one longitudinal side thereof to the bottom outer surface of the tray 17, and removes the tray 17 from the unloading section. 13, the film F is released from the grip and then retracted and returned to the initial position. Thereby,
The film F is folded under the bottom outer surface of the tray 17 on which the film F is loaded in the carry-out section 13. Thus, the film F is folded into the bottom outer surface of the tray 17 from both sides in the longitudinal direction, and the packaging is completed by the automatic packaging operation described above.

As shown in FIG.
Is a roll 18 on which the film F is wound, and the roll 1
The first guide roller 19a which guides the film F fed from 8 is supported at one end and the lower lever 20a pivotally supported at the other end, a film guide mechanism 21 disposed above these, and An upper lever 20b supporting at one end a second guide roller 19b for guiding the film F toward the other end, and having the other end supported by the film guide mechanism 21
And The film supply unit 14 has a stepping motor (not shown) serving as a driving source for feeding out the film F from the roll 18. The film F drawn from the roll 18 is guided by a guide roller 19.
The film guide mechanism 21 is set to be inserted through the film guide mechanism 21 via a and 19b, and is pulled out onto the lifter 66 of the packaging part 12 by the movement of the front gripper 61 of the packaging part 12.

The film guide mechanism 21 has a cutter 22 which is raised immediately after the completion of the packaging. This cutter 2
Reference numeral 2 is urged downward by a spring (not shown), and is raised and lowered in accordance with energization and cutoff of a solenoid (not shown).

Further, the film supply section 14 has a film presser 23. The presser 23 has a comb-teeth shape as shown in FIG. 6, and is arranged at a film outlet of the film guide mechanism 21 in a posture extending in the width direction of the film F as shown in FIG. The film presser 23 is provided so as to be movable in the vertical direction. The film presser 23 is pulled downward by a solenoid (not shown) attached to the film guide mechanism 21 as a driving source during the stretching of the film, and presses the fed film F. It is used to hold it still. Except when the film F is stretched (at this time, the solenoid is turned off), the film presser 23 is provided with a spring (not shown) for allowing the front gripper 61 to pull out the film F passed thereunder. In such a manner, it is held at the ascending position.

As shown in FIG. 3, the carry-out portion 13 is provided continuously with the packing portion 12 so as to be continuous at right angles to the carry-in portion 11 via the packing portion 12 between the front and rear frames 1a and 1c. Have been. The unloading section 13 includes a pair of support frames 25 parallel to each other, an unloading conveyer 26 rotatably supported between the pair of supporting frames 25, and a rotatable support frame 25 located on the side of the packaging section 12 of the conveyor 26. , A plurality of unloading rollers 27, a stepping motor 28 serving as a drive source for rotating the unloading conveyor 26 and each unloading roller 27, and an electric heater 29.

As shown in FIGS. 3 and 4, the unloading conveyor 26 has a drive roller 26a installed at an intermediate position of the support frame 25 and an end of the support frame 25 furthest from the packaging section 12. An output shaft 28a of a motor 28 is connected to the driven roller 26b and an endless conveyer belt 26c made of a heat-resistant material and stretched over both rollers 26a, 26b. The output shaft 28a and each of the unloading rollers 27 are connected via a chain transmission mechanism 30, respectively. Therefore, the belt-type carry-out conveyor 26 and each carry-out roller 27 are driven synchronously. Unloading section 13
Is disposed such that the discharge roller 27 is positioned inside the tray packaging device 1 and the horizontal belt type discharge conveyor 26 projects outside the tray packaging device 1.

The electric heater 29 has a flat radiator and a heater wire which is embedded in the meandering shape and generates resistance heat, and is disposed inside the carry-out conveyor belt 26c. This electric heater 29 is provided in the tray packaging device 1.
Is turned on at the same time as the power supply is turned on, generates heat and emits heat to the surroundings when the temperature rises, whereby the packaging is automatically packaged and delivered to the unloading unit 13 via the unloading roller 27. While the used tray 17a is placed on the carry-out conveyor belt 26c, the film F wrapping the tray 17 is heated by the electric heater 29, and
The film portion folded into the outer surface of the bottom is adhered to maintain an appropriate packaging state.

As shown in FIGS. 1 and 2, a door 6 for opening and closing the tray entrance 1b is attached to the tray entrance 1b for dust prevention and safety. The door 6 has a pivot 7 whose upper end is rotated by the power of a stepping motor (not shown).
It is supported by. Then, the door 6 is turned by the power of a stepping motor driven by turning on the supply switch 36 from the hanging posture shown by the solid line in FIG. 2 to the rear frame 1c side shown by the two-dot chain line. Then, the tray entrance 1b is opened, and after maintaining this open state for a certain period of time, it is closed.

For example, the door 6 in the closed state is
The sensor arrays 31 and 32 for detecting the tray 17 to be carried in and located near the rear side are provided.

The horizontal sensor array 31 is used as a detecting means for detecting the width and depth of the tray 17 from below the tray 17 and detecting the number of tray packages. The sensor array 31 includes a plurality of reflective sensors 31a (only one is shown) in which a light emitting element made of a light emitting diode and a light receiving element made of a phototransistor are paired.
Are arranged side by side at regular intervals in the width direction, and are arranged so as to pass through the inside of the carry-in belt conveyor 16 and cross the carry-in portion 11 in the width direction. Each sensor 31a is
The tray 17 is exposed between the belts 16a of the carry-in belt conveyor 16 and is not interrupted by the belts 16a.
To be able to face the bottom surface.

Vertical sensor array 32 forming a transmission type sensor
Is the height of the tray 17 (note that the article A inside is the tray 1
In the case of projecting from the opening 7, this projecting height is included. ), And only one of them is shown in FIG. 2, but is provided vertically at both ends in the width direction of the carry-in portion 11. On one vertical sensor array, a plurality of light emitting elements 32a made of light emitting diodes are provided at regular intervals in the vertical direction. The other light emitting element 32 is provided on the other vertical sensor array (not shown) facing the vertical sensor array 32.
A plurality of phototransistor light receiving elements for receiving light emitted horizontally from a are provided at regular intervals in the vertical direction.

In FIG. 7, reference numeral 71 denotes a control means, which comprises a main control unit 72 comprising a CPU or the like, which controls overall packaging operations, and a memory unit 73 connected thereto via a bidirectional bus. Have. The operation panel 2, the carry-in unit 11, the packaging unit 12, the carry-out unit 13, the film supply unit 14, the sensor arrays 31, 32, and the like are connected to the main control unit 72 via a bidirectional bus. The memory unit 73 stores various control tables, programs, and the like for controlling the packaging operation. The program includes a stretching amount setting program for executing the flowchart shown in FIG. 8, and the stretching speed of the film F by the side gripper 62 can be changed by executing the flowchart shown in FIG. A packaging program having a speed selection program to be executed is included. Control means 71
Thus, the timing of the pressing operation of the film presser 23 can be changed based on the film stretching amount calculated by the above formula. Next, these will be described.

The setting of the stretching amount in the width direction for the film F drawn on the lifter 66 is performed according to the flowchart shown in FIG.

That is, first, in step 1, it is determined whether or not the supply switch 36 has been pressed by the tray 17 and turned on. If the result is YES, the carry-in section 11 and both sensor arrays 31, 32 are operated, respectively. While detecting the size (width W, length L, height H, etc.) of the tray 17 with both the sensor arrays 31 and 32, the step 2 of supplying the tray 17 onto the lifter 66 of the packaging unit 12 is executed.

Next, the process proceeds to step 3, where the amount of film to be withdrawn is calculated from the detected size of the tray 17 in accordance with a predetermined formula for calculating the amount of film withdrawal, and the detected amount of tray 17 is determined. Is calculated according to the size of the film. The formula described in the section of the related art is used for calculating the amount of enlargement α.

Next, the routine proceeds to step 4, where it is determined whether or not the calculated stretching amount α is equal to or less than the maximum stretching amount β of the film F preset in the memory unit 73. Here, the maximum stretch amount β is the film F used.
Is determined by the width of the sheet F, the mechanical operation of the tray packaging apparatus 1 and the like, and is determined from the position at which the side gripper 62 grips the side edge of the drawn film F, that is, from the reference stretching position. This is a stretching upper limit position for preventing the film F from being broken when the side gripper 62 moves while stretching the film F in the width direction.
For example, in the tray packaging apparatus 1 using a 210 mm wide film, the maximum stretching amount on one side in the width direction of the film F is set to 155 mm.

If the determination in step 4 is YES (α
In ≦ β), the process proceeds to the next step 5 where a process of setting the calculated extension amount α smaller than the maximum extension amount β as the actual extension amount is performed. If the determination in step 4 is NO (α> β), the process moves to the next step 6, where the maximum stretching amount is equal to or greater than the calculated stretching amount β that is equal to or greater than the maximum stretching amount β. A process of setting β as an actual stretching amount is performed.

The film F drawn on the lifter 66
The setting for selecting the stretching speed in the stretching in the width direction is performed according to the flowchart shown in FIG.

That is, first, in step 11,
It is determined whether or not the actual extension amount α or β set by executing the flowchart of FIG. 8 is equal to or less than the speed switching amount γ set in advance as a reference value. Here, the speed switching amount γ is, for example, a threshold value forming a boundary between the two-stage stretching speeds of a high speed and a low speed, and the stretching amount reaching an intermediate position between the stretching start position and the maximum stretching upper limit position. Is set in advance. For example, a stretching amount corresponding to a position that is exactly half of the two positions is set as the speed switching amount γ.

The determination in step 11 is YE
In the case of S, that is, when the actually set stretching amount α is equal to or less than the speed switching amount γ, since the stretching amount is small, the stretching speed in the high-speed stage according to the stretching amount is It is selected and set by the processing in step 12.
If the determination in step 11 is NO, that is, if the actually set stretching amount α or β is equal to or greater than the speed switching amount γ, the stretching amount is large. The stretching speed in the low speed stage
Select and set by the processing in 3.

After the automatic setting of the selection of the stretching amount and the stretching speed based on the loading of the tray 17 as described above, the control means 71 controls a driving source such as each of the stepping motors and performs the following automatic operations. Execute the packaging operation.

First, step 14 is executed, and the packaging unit 1
The front gripper 61 moves forward with respect to the unloading section 13.
By retreating, the leading edge of the unwound film F is gripped and the film F is pulled out onto the lift 66 as described above as the wrapping operation in the wrapping unit 12. At this time, the control unit 71 controls the operation of retracting the front gripper 61 so as to move away from the unloading unit 13 so that the film F is withdrawn by the amount calculated in step 3. Thereafter, in step 14, both side grippers 62 of the wrapping unit 12 are moved in a direction of coming and going with respect to the drawn-out film F, and the film fed out as described above as the wrapping operation in the wrapping unit 12. The film F is stretched in the width direction while holding both side edges of F.

At this time, the control means 71 controls the movement of the side gripper 62 so that the film F is stretched in the width direction until the actual stretching amount α or β set in the processing of step 5 or 6 is reached. In addition to the control, the stretching speed in this moving operation is also controlled by the side gripper 62 at the high speed or the low speed selected in the step 12 or 13.
Is controlled to be moved.

In this manner, the film F is loaded onto the tray 1 with the stretching amount and the stretching speed based on the size of the tray 17.
The following step 15 is executed when the 7 is reasonably stretched to a size suitable for packaging. In this step 15, the control means 71 turns on the solenoid (not shown) at the time when the stretching amount reaches the predetermined stretching ratio, and pulls down the film presser 23 of the film supply unit 14 by the exciting force. Then, the unwinding side portion of the film F being stretched is pressed. As a result, the film F is supplied to the film supply unit 14 with the progress of the stretching.
Can be held so as not to be dragged out of the device.

Here, the stretching ratio is set in advance by an input operation on the operation panel 2, and the film presser 23 is pulled out at various timings when the amount reaches, for example, several tens% of the amount. The held film F is held down so as not to move. Therefore, the larger the amount of stretching, the more the film presser 23 performs the pressing operation at a later timing from the start of the stretching of the film F. In other words, the control means 71 in step 15
Thus, the pressing operation of the film presser 23 can be changed according to the amount of stretching of the film F.

In the next step 16, the control means 71 continues the packaging operation to complete the packaging. That is, first, by lifting the lifter 66 of the packaging unit 12,
The tray 17 on the lifter 66 hits the film F that has been drawn out and stretched in the width direction from below, and is pushed up while further stretching this film F. Next, as described above as the wrapping operation in the wrapping section 12, the both side grippers 62 are controlled to move to the bottom side of the tray 17, and the film F is folded into the bottom outer surface of the tray 17, and then the front gripper 61 is moved to the unloading section. 13 to the film F
Of the tray 17 is folded into the outer surface of the bottom of the tray 17 and the tray 17 is pushed in so as to ride on the carry-out portion 13. As a result, the film F is folded into the bottom outer surface of the tray 17 which can be carried on the carry-out section 13,
The bottom surface of the tray 17 is packed. Thereafter, the cutter 22 is raised to cut the film F wrapping the tray 17, then the grip of the film F by the front gripper 61 is released, and the gripper 61 is retracted to return to the initial position. Finally, the unloading section 13 on which the tray 17 packed by the front gripper 61 has been transferred has been unloaded, and the packed tray 17 is unloaded. The packaging is completed by the above-mentioned automatic packaging operation, and is prepared for carrying in the next tray 17.

According to the automatic packaging described above, the control means 71 calculates the width α of the film f in the width direction based on the detected size of the tray 17, and the calculated amount α is set in advance. When the maximum stretching amount β is larger than the maximum stretching amount β, the wrapping operation in the packaging unit 12 is controlled according to the maximum stretching amount β, so that the film F is not excessively stretched according to the calculated stretching amount α, Film F due to simple overstretching based on calculations
Can be packaged while preventing tearing.

FIG. 10 shows such a stretching restriction.
, That is, the stored articles f
Is added when packaging the tray 17 projecting more than the upper surface opening. However, the stretching amount of the film F necessary for actually wrapping the tray 17 as described above is determined by the stretching amount α calculated as described in the section of the related art.
Less than the calculated stretch amount α, although the value of the preset maximum stretch amount β is smaller than the calculated stretch amount α,
As shown in FIG. 10B, packaging can be performed without any trouble.

Further, the control means 71 calculates a film stretching amount α based on the detected size of the tray 17,
A high-speed or low-speed stretching speed corresponding to the calculated amount α is selected. This selection is to select a stage stretching speed corresponding to the calculated stretching amount α from the preset two stages of stretching speed, so that the actual stretching amount is larger than the speed switching amount γ. In this case, the film F can be stretched at a low speed, and when the stretching amount is smaller than the speed switching amount γ, the film F can be stretched at a high speed. The control means 71 causes the film F to be stretched in the width direction in accordance with the speed selected in this way. Therefore, the film F is prevented from being broken due to giving the film F an excessive stretching speed, and the tray 1 is prevented from being broken.
The film F stretched according to the size of 7 can be stretched and packaged at an appropriate speed.

Since the stretching speed is automatically selected as described above, in order to prevent the film F from being torn due to the stretching speed, the stretching speed of the film F is set for all the stretching amounts. There is no need for automatic packaging at a low speed. This makes it unnecessary to slowly stretch the film F even when the calculated stretching amount α is small, and stretching can be performed at a high speed as described above, so that packaging efficiency can be improved.

Further, when the film F is stretched in the width direction as described above, the film F
Film presser 23 to prevent it from being pulled out from the side
Does not press the film F that has already been drawn at the start of the stretching of the film F, but is operated by the control means 71 so as to press the film F after the start of the stretching. In this case, in accordance with the stretching amount α calculated based on the size of the tray 17, as the amount α increases, the pressing operation of the film presser 23 is performed at a timing later than the starting point of the stretching.

Thus, when the amount of stretching of the film F is large, the film F is pulled out to some extent from the beginning, thereby suppressing the excessive stretching force from acting on the film F. The film F can be stretched and packaged. Such a film holding section 23
By controlling the timing of the pressing operation, it is possible to suppress an excessive stretching force from acting on the film F. Therefore, it is possible to prevent the film F from being broken by the film pressing portion 23 and perform packaging. Further, when the stretch amount of the film F is small, the film F can be pressed so as not to be pulled out at an early stage, and can be packed while preventing a decrease in the stretching force.

The present invention is not limited to the first embodiment, but may be any automatic packaging apparatus for packaging objects other than trays. Further, in the first embodiment, the regulation on the maximum stretching amount, the selection of the stretching speed, and the variation of the timing of the film press are all performed, but any one or more of these is performed. May be used as an automatic packaging device. When the stretching speed is selected to prevent the film from being broken, the speed may be selected from three or more, such as high speed, medium speed, and low speed.
In the present invention, the “stretch amount” is an expression viewed from the film F, but may be replaced with a “stretch position” in order to obtain an expression viewed from the side gripper.

[0065]

The present invention is embodied in the form described above and has the following effects.

According to the first aspect of the present invention, the film for wrapping the article to be packaged is not stretched excessively according to the stretching amount calculated according to the size of the article to be packaged. Packaging can be performed while preventing tearing of the film due to overstretching.

According to the second aspect of the present invention, the film for wrapping the package is stretched at an appropriate speed corresponding to the stretching amount calculated according to the size of the package.
Packaging can be performed while preventing the film from being broken due to an excessive stretching speed.

According to the third aspect of the present invention, the timing of the pressing operation of the film press for preventing the film drawn into the packaging portion from being pulled out from the film supply portion when the film is stretched is varied, When the stretching amount of the film is large, it is possible to suppress an excessive stretching force from acting on the film, so that the film can be prevented from being broken due to the film presser and can be packaged.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an entire tray packaging apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a configuration of a carry-in section of the tray packaging device according to the first embodiment.

FIG. 3 is a plan view showing a positional relationship among a carry-in unit, a packing unit, and a carry-out unit of the tray packaging device according to the first embodiment.

FIG. 4 is a cross-sectional view showing a positional relationship between a carry-out unit and a film supply unit shown along the line ZZ in FIG. 3;

FIG. 5 is a sectional view showing a configuration of a packaging unit of the tray packaging device according to the first embodiment.

FIG. 6 is a plan view showing a state in which the film is stretched in the packaging section of the tray packaging apparatus according to the first embodiment.

FIG. 7 is a block diagram showing an electrical configuration of the tray packaging device according to the first embodiment.

FIG. 8 is a flowchart showing a stretch amount setting program executed in the tray packaging apparatus according to the first embodiment.

FIG. 9 is a flowchart showing a packaging program including a stretching speed selection program executed in the tray packaging apparatus according to the first embodiment.

FIG. 10A is a diagram illustrating an example of an article to be packaged. (B) is a figure which shows the packaging state by which the film was folded in the bottom outer surface of the thing to be packaged shown in FIG. 10 (A).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tray packaging apparatus (automatic packaging apparatus), 11 ... Carry-in part, 12 ... Packaging part, 13 ... Carry-out part, 14 ... Film supply part, 23 ... Film presser, F ... Film, 17 ... Tray (object to be packaged), 31: Horizontal sensor array (detection means), 32: Vertical sensor array (detection means), 61: Front gripper, 62: Side gripper, 71: Control means, 72: Main control section, 73: Memory section, α: Calculation reference Stretching amount, β: Maximum stretching amount, γ: Speed switching amount.

Claims (3)

[Claims] 1. A film supply unit, a packaging unit that stretches a film fed from the supply unit and wraps and wraps a packaged object, a carry-in unit that supplies the packaged object to the packaging unit, and a carry-in unit Detecting means for detecting the size of the object to be packaged, which is provided in the packaging part and supplied to the packaging part; and calculating the amount of stretching of the film according to the size of the object to be packaged detected by the detecting means. When the calculated amount of stretching is larger than a preset maximum amount of stretching, the packaging unit includes a control unit for performing a film stretching operation with the maximum amount of stretching being an upper limit. Automatic packaging equipment. 2. A film supply unit, a packaging unit that stretches the film fed from the supply unit and wraps the packaged object, a carry-in unit that supplies the packaged object to the packaging unit, and a carry-in unit. Detecting means for detecting the size of the object to be packaged, which is provided in the packaging part and supplied to the packaging part; and calculating the amount of stretching of the film according to the size of the object to be packaged detected by the detecting means. And, a stretching speed of a stage corresponding to the calculated stretching amount is selected from the stretching speeds of at least two stages set in advance, and the selected stretching speed is used in the packaging unit. An automatic packaging apparatus comprising: a control unit configured to perform the film stretching operation. 3. A film feeder having a film presser for feeding the film and pressing the fed film so as not to move, and a front for pulling out the film fed from the film feeder by gripping a leading edge of the film. It has a gripper and a side gripper that grips a side edge of the film drawn by the gripper and stretches the film in the width direction, and stretches the drawn film to fold and wrap a packaged object. A packaging unit; a loading unit that supplies the packaged object to the packaging unit; a detection unit provided in the loading unit and configured to detect a size of the packaged product supplied to the packaging unit; Calculates the amount of stretching of the film according to the size of the object to be detected, and moves the film to the side gripper in the width direction thereof. An automatic wrapping apparatus comprising: control means for varying the pressing operation of the film presser at a timing later than the starting point of the stretching as the amount is larger according to the calculated stretching amount when the stretching is performed.