JPH11115906A - Cover mounting equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mount a cover body on a packaging container in a condition where an enough strength is maintained, and to increase the processing speed. SOLUTION: This equipment is provided with a rotating body which is supported freely rotatable and intermittently rotates in a predetermined degree by a driving means, a package holder 14 which is provided at more than one position on the periphery of the rotating body and holds a packaging container 17, a cap holder 57 which holds a cover corresponding the move of the package holder 14, a burner 71 which is positioned at the lower part of the cap holder 57 and heats the cover back face from the lower part, and an adjusting means which adjusts the distance between the cap holder 57 and the burner 71 while the package holder 14 is being moved. By adjusting the distance between the cap holder 57 and the burner 71, the heating amount by the burner 71 can be adjusted, and the peripheral edge of the cover back face can be heated for the most appropriate time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cover (lid) body mounting device.

[0002]

2. Description of the Related Art Conventionally, in a brick-type packaging container for storing liquid food such as milk and soft drinks, a lid that can be opened and closed is disposed on a top wall so that the liquid food can be repeatedly poured out. Is provided. In this case, the lid is attached to the packaging container by a hot melt method, a heat sealing method, an ultrasonic sealing method, or the like by the lid attaching device.

In the hot-melt method, a liquid adhesive is sprayed from a nozzle of a hot-melt gun and sprayed onto a cover attaching portion of a packaging container, and the lid is attached to the packaging container with the adhesive. Further, in the heat sealing method, hot air is blown onto a cover attachment portion of a packaging container to melt a film on a surface of a packaging material forming the packaging container, and the lid is attached to the packaging container.

Further, in the ultrasonic sealing method, ultrasonic waves are applied to the lid in a state where the lid is pressed against the lid attaching portion of the packaging container, and the ultrasonic wave forms a film on the surface of the packaging material forming the packaging container. Is melted, and the lid is attached to the packaging container.

[0005]

However, in the above-mentioned conventional lid mounting method, in the case of the hot melt method, it is difficult to spray the adhesive accurately and evenly on the lid mounting portion of the packaging container. As a result, not only is it difficult to attach the lid to the packaging container while maintaining sufficient strength, but if the adhesive is sprayed excessively, the appearance and feel of the packaging container will be impaired.

Further, in the heat sealing method, hot air is blown onto the cover mounting portion of the packaging container to melt the film on the surface of the packaging material forming the packaging container, so that the temperature of the hot air is raised. Not only does this increase the time required to melt the film, but it also increases the time required to melt the film, thus reducing the processing speed.

[0007] In the ultrasonic sealing method, since the film on the surface of the packaging material forming the packaging container is melted by ultrasonic waves, it is necessary to provide an ultrasonic generator, and the lid is attached. The cost of the device increases. In addition, the time required to melt the film becomes longer, so that the processing speed becomes lower.

[0008] The present invention solves the problems of the above-mentioned conventional method of attaching a lid, and can attach the lid to a packaging container with a simple mechanism while maintaining sufficient strength.
It is an object of the present invention to provide a lid attachment device that can reduce the cost and increase the processing speed.

[0009]

For this purpose, in the lid mounting apparatus of the present invention, a rotating body rotatably supported and intermittently rotated by a predetermined angle by a driving means, and a peripheral portion of the rotating body. A package holder that is provided at a plurality of locations and holds the packaging container; a cap holder that holds the lid in accordance with the movement of the package holder; and a back surface of the lid that is disposed below the cap holder and And a adjusting means for adjusting the distance between the cap holder and the burner while the package holder is being moved.

In another lid mounting apparatus of the present invention, the adjusting means further includes a cam, a follower brought into contact with a cam surface of the cam, and a cam moving means for moving the cam in a vertical direction. In still another lid mounting device of the present invention, a cap holder for gripping the lid, a preheating device disposed below the cap holder and preheating the lid, A burner that is disposed and heats the back surface of the lid after preheating, from below.

In still another lid mounting apparatus of the present invention, the preheating apparatus further comprises a hot air generating means for generating hot air, a nozzle for blowing hot air on the back surface of the lid, and a constant temperature of the hot air. Temperature control means.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 is a conceptual diagram of a lid attaching device according to the first embodiment of the present invention, and FIG.
FIG. 4 is a plan view of the ring cam according to the first embodiment of the present invention, and FIG. 4 is a developed view of the ring cam according to the first embodiment of the present invention.

In FIG. 1, reference numeral 11 denotes a cover attaching device, 12 denotes a shaft, and 13 denotes a shaft rotatably supported around the shaft 12. The motor is driven intermittently in the direction of arrow A by driving a motor (not shown). It is a main wheel as a rotating body that is rotated. In the present embodiment, the main wheel 13 can be accurately rotated by 45 ° by an intermittent feed gear unit (not shown).

The main wheel 13 has an octagonal shape, and package holders 14 are provided at a plurality of locations on the periphery of the main wheel 13. Each of the package holders 14 includes two brick-type packaging containers 17.
Holding portions 15 and 16 are provided so as to be able to hold. Then, the package holder 14 is sequentially moved to the first position S1 to the eighth position S8 by driving the motor and rotating the main wheel 13 by 45 °.

A conveyor 21 is provided for feeding the packaging container 17 to the lid mounting device 11 and discharging the packaging container 17 after the lid (not shown) has been mounted. The conveyor 21 extends along the main wheel 13 at the first position S1 and the eighth position S8, and
It is run in the direction. An in-feed brake 31 is provided before the first position S1 in the traveling direction of the conveyor 21, and a hose brake 29 is further provided before the in-feed brake 31. The packaging containers 17 conveyed on the conveyor 21 are firstly braked by a hose brake 29, and subsequently braked by an in-feed brake 31 to limit the number thereof.
And they are brought close together. Then, the in-feed brake 31 sends each packaging container 17 one by one to the first position S1 at regular intervals.

At the first position S1, an infeeder 32 is provided so as to face the package holder 14. The infeeder 32 continuously sets a pair of packaging containers 17 positioned on the conveyor 21 by the positioning device having the first stopper 85 and the second stopper 88 in the package holder 14. For this purpose, the first stopper 85 and the second stopper 88 are provided so as to be able to move forward and backward, and each of the packaging containers 17 on the conveyor 21 is stopped in a state where the first stopper 85 and the second stopper 88 are advanced. Can be. Note that the first stopper 85 is normally placed in an advanced state. The infeeder 32 includes a pair of pushers 3.
The packaging container 17 is pushed into the holding portions 15 and 16 by the pushers 33 and 34, respectively. The pushers 33 and 34 are provided with air cylinders 35 and 3
The air cylinders 35 and 36 are driven by supplying and discharging compressed air via a compressed air circuit (not shown).

When the pair of packaging containers 17 are set in the package holder 14 in this manner, the main wheel 13 is rotated by 45 °, and each of the package holders 14 moves to the next position. . Therefore, the package holder 14 on which the packaging container 17 is set is placed at the second position S2. At the second position S2, hot air is blown against the top wall of the packaging container 17, and the hot air blows off water droplets and the like adhering to the top wall, and the surface of the packaging container 17 Is preheated.

Subsequently, the main wheel 13 is 45
[°] The package holder 14 in which the packaging container 17 has been turned is placed in the third position S3. Meanwhile, the packaging container 17 is formed by sealing a web-shaped packaging material (not shown) in a vertical direction into a tubular shape, then sealing in a horizontal direction, and cutting at a sealed portion into a prototype container. It is formed by molding.

The wrapping material has a multilayer structure, and includes a paper base (not shown), a resin film such as polyethylene which covers the outer surface of the paper base to form an outermost layer, and A resin film such as polyethylene which covers the inner surface and forms the innermost layer is provided. If necessary, a gas barrier layer made of an aluminum foil (foil) layer having gas barrier properties may be provided between the paper base and the innermost layer.

A lid is attached to a predetermined lid attachment portion on the top wall of the packaging container 17, for example, a corner portion. The lid body is integrally formed of a resin, for example, a polyethylene resin, and has a substantially U-shaped main body, a pull tab that is swingably supported around a hinge, and a swingable body around the hinge. Movably supported,
And it has an opening flap rotated in conjunction with the rotation of the pull tab.

Therefore, when the pull tab is pulled up and rotated, the opening flap is rotated in conjunction with the rotation of the pull tab, so that the packaging material of the packaging container 17 is broken and the spout is opened. Therefore, in the portion corresponding to the lid in the packaging material, a break area is set substantially corresponding to the shape of the lid, and when the break area is pushed down with the rotation of the opening flap, the break area is broken. , The spout is opened.

In order to attach the lid to the packaging container 17, a picking device (not shown) is provided above each package holder 14, and the picking device comprises:
The main wheel 13 is rotated together with the package holder 14 as the main wheel 13 is rotated, and holds the pair of lids at the third position S3. A cap feeder 41 for supplying a lid to the picking device is provided at the third position S3.

The cap feeder 41 includes a pair of rails 4.
The lids provided with the caps 3 and 44 and peeled off from the cap ladders 45 and 46 are supplied to one end of each of the rails 43 and 44, and are conveyed on the rails 43 and 44 by vibration and wind pressure. Has become. And the rails 43, 4
When each of the lids reaches the other end of 4, the picking device grips the pair of lids by vacuum suction using a cap holder (not shown). During this time, the packaging container 1
7 is placed below the picking device while being held by the package holder 14.

Subsequently, the main wheel 13 is 45
The package holder 14 on which the packaging container 17 is set is rotated at the fourth position S4. In addition, the picking device also holds the fourth
It is placed at position S4. Then, at the fourth position S4, the back surface of each lid is heated and melted from below by a burner unit (not shown) disposed below the cap holder.

Next, the main wheel 13
The package holder 14 on which the packaging container 17 has been set is rotated at the fifth position S5. In addition, the picking device also holds the fifth
It is placed at position S5. Then, at the fifth position S5, the picking device is moved downward, and the lid is pressed against the corresponding packaging container 17. At this time, since the back surface of the lid is melted, the resin film on the surface of the packaging container 17 is melted.

Subsequently, the main wheel 13
The package holder 14 in which the packaging container 17 is set is rotated by [°] and is placed at the eighth position S8 via the sixth position S6 and the seventh position S7. During this time, the picking device also moves to the eighth position S8 with the lid pressed against the packaging container 17. During this time, the back surface of the lid and the surface of the packaging container 17 are fused.

When the lid is attached to the packaging container 17 in this manner, at the eighth position S8, the holder 1
The packaging containers 17 respectively held by 5 and 16 are pushed out of the holding portions 15 and 16 onto the conveyor 21 by an out feeder (not shown). Then, packaging container 1
7 is conveyed by the conveyor 21 and sent to the next step.

In the picking device, the back surface of the lid is melted by the burner unit at the fourth position S4, moved downward at the fifth position S5, and moved to the seventh position S7. In between, the lid is pressed against the packaging container 17 and attached. Thereafter, the picking device is moved upward at the eighth position S8.

For this purpose, a ring cam 50 having a structure as a so-called end face cam is arranged above the main wheel 13 and in the circumferential direction.
A cam follower (not shown) moves in the direction of arrow C along a cam surface set on the lower surface of the zero. As shown in FIG. 4, the ring cam 50 has a narrow width from the first position S1 to the fourth position S4, and has a fifth position S5.
The width is widened from to the seventh position S7. Further, an inclined portion K1 is formed between the fourth position S4 and the fifth position S5, and the width is gradually increased in the inclined portion K1.
Then, an inclined portion K2 is formed between the eighth position S8 and the first position S1, and the width of the inclined portion K2 is gradually reduced.

Adjustment cams 51 to 54 are provided before and after the inclined portions K1 and K2 so that the cam followers can smoothly enter the inclined portions K1 and K2 and exit the inclined portions K1 and K2. Will be arranged. At the third position S3 and the fourth position S4, an auxiliary cam (not shown) is provided to be vertically movable to temporarily move the picking device downward.

Next, the burner unit disposed at the fourth position S4 will be described. FIG. 1 is a view showing an arrangement state of a burner unit according to a first embodiment of the present invention.
FIG. 6 is a front view of a main part of the burner unit according to the first embodiment of the present invention, FIG. 6 is a side view of a main part of the burner unit according to the first embodiment of the present invention, and FIG. 7 is a first embodiment of the present invention. FIG. 8 is a plan view of a main part of a burner unit according to the first embodiment, and FIG. 8 is a schematic diagram of a picking device according to the first embodiment of the present invention.

In the figure, 14 is a package holder, 1
7 is a packaging container, 50 is a ring cam, and 55 is a picking device. The picking device 55 includes a main wheel 1
3 (FIG. 2) has a plate 56 supported movably in the up-down direction with respect to the frame F, and a pair of cap holders 57 suspended downward from the plate 56. An uncovered lid can be gripped by vacuum suction.

A guide post 61 extending downward from the plate 56 is supported on the frame F so as to be able to advance and retreat, and the plate 56 is urged upward by a spring 62. On the upper surface of the plate 56, a follower 63 is rotatably supported by contacting the cam surface of the ring cam 50, and an auxiliary follower 65 is rotatably supported by contacting the cam surface of an auxiliary cam 64. Supported. Further, the cam 64 is connected to an air cylinder 67 of a driving device 66 as a cam moving means, and is moved vertically by the air cylinder 67.

A burner unit 72 is provided below each cap holder 57. The burner unit 72 includes a plate 73 and each of the cap holders 57.
And a pair of burners 71 fixed to the plate 73 so as to face the suction surface S11. Each of the burner units 72 includes a nozzle group including a plurality of nozzles 74, and forms a plurality of minute flames by injecting a hydrogen / oxygen gas mixture from an opening (not shown) formed at the tip of each nozzle 74. You can do it. An igniter (not shown) is provided adjacent to one nozzle 74 in the nozzle group, and each nozzle 74 is ignited by the igniter. Each of the nozzles 74
Are arranged according to the shape of the lid, and are formed by a long pipe with a small diameter, so that only the peripheral portion on the back surface of the lid can be melted.

Since the nozzles 74 are arranged in a substantially "U" -shaped pattern at regular intervals as shown in FIG. 7, all of the nozzles 74 are formed at once by the igniter. Can not ignite. In this case, when the igniter is operated, only the nozzle 74 adjacent to the igniter is ignited, and the remaining nozzles 74 are not ignited. Therefore, as shown in FIG.
After the nozzles 74 adjacent to the igniter are ignited, a shielding (shield) plate 75 is disposed above each nozzle 74. In this case, the hydrogen / oxygen gas mixture injected from the non-ignited nozzle 74 tends to rise, but is shielded by the shielding plate 75, and is deflected by the synergistic action of the air flow generated at that time and spreads in the lateral direction. Therefore, only by igniting one nozzle 74 adjacent to the igniter, all the remaining nozzles 74 can be ignited.

By the way, the flame formed at the tip of each of the nozzles 74 melts the peripheral portion of the back surface of the lid, but when the peripheral portion of the rear surface of the lid is heated for a predetermined time or more. However, it is impossible to accurately heat and melt only the peripheral portion of the back surface of the lid, and the hinge of the lid may be erroneously heated and deformed. Therefore, a cam 64 is provided independently of the ring cam 50,
By operating the air cylinder 67 and rotating the follower 65 along the cam surface of the cam 64, the cap holder 5 is set for a set time and for a set amount.
7 can be moved downward so that heating by the burner 71 can be performed. In this case, the amount of heating by the burner 71 can be adjusted by adjusting the distance between the cap holder 57 and the burner 71.
Further, by changing the size and shape of the cam 64, the amount of heating by the burner 71 can be adjusted. The cam 64, the follower 65, and the driving device 6
6 constitutes an adjusting means.

Therefore, the peripheral portion of the back surface of the lid can be heated for an optimum time, so that only the peripheral portion of the rear surface of the lid can be accurately heated and melted. As a result, the hinge of the lid is not erroneously heated and the hinge is not deformed. In addition, since it is not necessary to arrange or remove a shielding member or the like between the cap holder 57 and the burner 71 in order to adjust the amount of heating by the burner 71, the operation can be simplified, and The overall processing time can be shortened. Moreover,
Since there is no need to use an ultrasonic generator, the cost of the lid mounting device can be reduced.

A rail 81 is provided so that the burner unit 72 can be advanced and retracted in the radial direction so as to be able to take an advanced position and a retracted position. Is disposed on the lower surface of the plate 73. Further, the burner unit 72 is placed at the forward position and heated by the burner 71. When the heating is completed, the burner unit 72 can be retracted along the rail 81 and placed at the retracted position. Therefore, it is possible to prevent the picking device 55 from interfering with the burner 71 when the heating is completed and the picking device 55 is to be moved downward.

In this embodiment, the lid is heated by the burner unit 72 to melt the peripheral edge of the back surface of the lid. In the burner unit 72, hydrogen / oxygen is used as fuel. Since the gas mixture is used to form a plurality of minute flames, the temperature of the flame is raised to 2000 ° C. or more to melt the peripheral edge of the back surface of the lid. However,
Since the lid is formed of a resin that is a heat-defective conductor, for example, a polyethylene resin, heat is not transmitted to the inside of the resin, and when the flame of the burner 71 is brought close to the lid, only the surface of the peripheral portion is melted. Would be done. In that case, it becomes difficult to attach the lid to the packaging container 17 while maintaining sufficient strength.

Therefore, a predetermined distance (in the present embodiment, the distance between the burner 71 and the lid is about 5 mm) is set between the flame and the lid, and the heating time is set. Is set to be long. Therefore, the package holder 14 is kept in the fourth position S4 for about 0.6 to 0.7 seconds until the peripheral portion of the back surface of the lid reaches a predetermined temperature.
(FIG. 4) must be placed on the main wheel 13
Must be stopped. As a result, the processing time of the lid attaching device 11 (FIG. 2) is prolonged.

Further, if the outside air temperature fluctuates and the temperature of the lid changes, the time required for the peripheral portion to reach a predetermined temperature changes. Therefore, the peripheral portion cannot be sufficiently heated and melted, or the peripheral portion is heated and melted more than necessary. Therefore, a second embodiment in which the lid is pre-heated before the lid is heated by the burner unit 72 will be described.

FIG. 9 is a conceptual diagram of a preheating device according to a second embodiment of the present invention. In the figure, reference numeral 91 denotes a lid, and the lid 91 is held by the cap holder 57 (FIG. 1) at the third position S3 (FIG. 4). Reference numeral 92 denotes a nozzle disposed below the cap holder 57 at the third position S3. The nozzle 92 preheats the lid 91. Therefore, the nozzle 92
Has a plurality of orifices 93 arranged in a pattern having a shape corresponding to the peripheral portion of the lid 91, and is connected to a heater 94 as hot air generating means and a blower (not shown) via a line L1. Therefore, the hot air generated by the heater 94 is
2 and is sprayed from the orifice 93 onto the back surface of the lid 91 for about 0.5 seconds.

A switch 95 is provided on the line L1. The switch 95 is opened for a time set at a predetermined timing by the controller 97. A temperature sensor 96 is disposed on the line L1, and a temperature control unit (not shown) of the control device 97
The feedback control is performed based on the temperature of the hot air detected by the control unit 6, and the temperature of the hot air is maintained at about 370 ° C. The preliminary heater is constituted by the heater 94, the nozzle 92 and the temperature control means.

As described above, since the lid 91 is preheated, the time required for the peripheral portion on the back surface of the lid 91 to reach a predetermined temperature can be shortened. Therefore, the time for keeping the package holder 14 at the fourth position S4, that is, the time for keeping the main wheel 13 stopped, can be shortened, and the processing time of the lid mounting device 11 (FIG. 2) can be shortened accordingly. can do.

Even if the outside air temperature fluctuates and the temperature of the lid 91 changes, the initial temperature of the lid 91 can be kept constant by performing preheating. Therefore, the time required for the peripheral portion to reach the predetermined temperature can be made constant, so that the peripheral portion can be stably heated and melted. It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0046]

As described in detail above, according to the present invention, the lid mounting device is rotatably supported,
A rotating body that is intermittently rotated by a predetermined angle by a driving unit, a package holder that is disposed at a plurality of locations on a peripheral edge of the rotating body and holds a packaging container, and a lid body that corresponds to the movement of the package holder Between the cap holder and the burner while the package holder is being moved, and a burner that is disposed below the cap holder and heats the back surface of the lid from below. Adjusting means for adjusting the distance.

In this case, the amount of heating by the burner can be adjusted by adjusting the distance between the cap holder and the burner. Therefore, the peripheral portion of the back surface of the lid can be heated for an optimum time, so that only the peripheral portion of the rear surface of the lid can be accurately heated and melted. As a result, the hinge of the lid is not erroneously heated and the hinge is not deformed.

Further, since it is not necessary to arrange or remove a shielding member or the like between the cap holder and the burner in order to adjust the amount of heating by the burner, the operation can be simplified. The overall processing time can be shortened. In addition, the cost of the lid mounting device can be reduced. In another lid mounting apparatus of the present invention, the adjusting means further includes a cam, a follower that is brought into contact with a cam surface of the cam, and a cam moving means that moves the cam in a vertical direction.

In this case, the amount of heating by the burner can be adjusted by changing the size and shape of the cam. In still another lid mounting device of the present invention,
A cap holder that grips the lid, a preheating device that is disposed below the cap holder and preheats the lid, and a preheating device that is disposed below the cap holder and is preheated. And a burner for heating the back surface from below.

In this case, since the lid is preheated, the time required for the peripheral portion on the back surface of the lid to reach a predetermined temperature can be shortened. Therefore, the processing time of the lid attaching device can be shortened. Further, even if the outside air temperature fluctuates and the temperature of the lid changes, the initial temperature of the lid can be kept constant by performing preheating. Therefore, the time required for the peripheral portion to reach the predetermined temperature can be made constant, so that the peripheral portion can be stably heated and melted.

[Brief description of the drawings]

FIG. 1 is a diagram showing an arrangement state of a burner unit according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram of a lid attaching device according to the first embodiment of the present invention.

FIG. 3 is a plan view of the ring cam according to the first embodiment of the present invention.

FIG. 4 is a development view of the ring cam according to the first embodiment of the present invention.

FIG. 5 is a front view of a main part of the burner unit according to the first embodiment of the present invention.

FIG. 6 is a side view of a main part of the burner unit according to the first embodiment of the present invention.

FIG. 7 is a plan view of a main part of the burner unit according to the first embodiment of the present invention.

FIG. 8 is a schematic diagram of a picking device according to the first embodiment of the present invention.

FIG. 9 is a conceptual diagram of a preheating device according to a second embodiment of the present invention.

[Explanation of symbols]

 13 Main Wheel 14 Package Holder 17 Packaging Container 57 Cap Holder 64 Cam 65 Follower 66 Driving Device 71 Burner 91 Lid 92 Nozzle 94 Heater 97 Control Device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Wolf Mossberg 211 20 Erubegerten 5 in Malmo, Sweden 5 (72) Inventor Hiroyuki Nishimura 6-12 Kioicho, Chiyoda-ku, Tokyo Inside Tetrapak Co., Ltd. (72) Inventor Masamichi Kaneko 6-12 Kioicho, Chiyoda-ku, Tokyo Inside Tetrapack Co., Ltd. (72) Inventor Toru Ishikawa 6-12 Kioichocho, Chiyoda-ku, Tokyo Inside Tetrapak Japan Co., Ltd. (72) Katsumi Mukaino 6-12 Kioicho, Chiyoda-ku, Tokyo Nippon Tetra Pack Co., Ltd.

Claims (4)

[Claims] 1. A rotating body rotatably supported and intermittently rotated by a predetermined angle by a driving means,
(B) package holders arranged at a plurality of locations on the peripheral edge of the rotating body and holding a packaging container; (c) a cap holder for gripping a lid corresponding to the movement of the package holder; and (d). And (e) adjusting the distance between the cap holder and the burner while the package holder is being moved, the burner being disposed below the cap holder and heating the back surface of the lid from below. A lid attaching device, comprising: an adjusting unit. 2. The lid mounting apparatus according to claim 1, wherein the adjusting means includes a cam, a follower that is brought into contact with a cam surface of the cam, and a cam moving means that moves the cam in a vertical direction. 3. A cap holder for holding a lid, (b) a preheating device disposed below the cap holder for preheating the lid, and (c) a lower portion of the cap holder. And a burner disposed on the back side and heating the back surface of the preliminarily heated lid from below. 4. The preheating device includes: a hot air generating means for generating hot air; a nozzle for blowing hot air on a back surface of the lid;
4. The lid attachment device according to claim 3, further comprising a temperature control unit for keeping the temperature of the hot air constant.