KR20010077864A - Method and apparatus for packing material - Google Patents

Abstract

The present invention relates to a filling method and a filling apparatus, wherein the filling method includes a container and a space portion coupled with the container, and alternately switches the air pressure state of the space for loading the material from the low air pressure state to the high air pressure state, The material is filled into the container by an air tapping process which maintains the low air pressure state higher than or equal to the atmospheric pressure existing outside the space, thereby preventing the inflation of the material due to the flow of atmospheric air outside the container. And the material is equally filled in the container.

Description

Filling method and filling device for filling materials {METHOD AND APPARATUS FOR PACKING MATERIAL}

The present invention relates to powders, granular materials, flake materials, plate materials or the like (collectively referred to herein as "materials"), openings for filling the powder or the like and receiving the material. The present invention relates to a filling method and a filling device for pouring into a can, a bag, a rubber mold, a die, or a container of the same type.

Applicant has described a method of filling materials using air-tapping methods in containers, cans, bags, rubber molds, dies or the like in Japanese prior applications KOKAI H9-78103, KOKAI H9-169301 and KOKAI H11-49101. Started.

By applying the above air filling method, the scattering of a large amount of material per filling is reduced, and the local difference in packing density of the materials in the container is reduced.

A conventional charging method will be described below with reference to FIGS. 5, 6 and 7. FIG. Here, the die and the punch inserted into the die form a container into which the powder is injected.

The portion 1 shown in FIG. 5 is a cylindrical die and the portion 2 is a punch inserted into the die 1 (hereafter referred to as “lower punch”). The powder is filled in a die cavity 3, which is a space formed by the die 1 and the lower punch 2. The table 4 is arranged such that the upper surface of the table is flush with the upper surface 1a of the die 1. A supply element (hereinafter referred to as "supply shoe") 5 without a box-shaped bottom is attached on the table 4. The outer wall of the projection of the supply shoe 5 is provided with a pipe 6 connected to the inhaler type vacuum generator 7. The pipe 8 connected to the outer wall 5a of the supply shoe 5 is connected to the compressed air supply 10 via an electromagnet valve 9. The part 11 is a cover attached to the upper opening of the part 5a of the supply shoe 5. The supply shoe 5 loads the powder p. The horizontal cylinder 12 is attached to the table 4 and the piston rod 12a attached to the horizontal cylinder is connected to the supply shoe 5.

In order to fill the die cavity 3 formed by the die 1 and the lower punch 2 inserted into the die 1 with powder p, a feed shoe 5 attached on the table 4 is shown in FIG. As shown in FIG. 6, the feed shoe 5 is moved by driving a horizontal cylinder 12 which moves the piston rod 12a until the feed shoe 5 is positioned on the die cavity 3. At that time, the powder 5 stored in the feed shoe falls into the die cavity 3.

Then, when the suction type vacuum generator 7 is operated together with the electromagnetic valve 9 in which the suction type vacuum generator 7 is closed, the air pressure is supplied to the inside of the supply shoe 5 in a standby state (a). Changes to the state (b) lower than atmospheric pressure. 7 shows an example where the low pneumatic state b is 0.5 atm. At that time, by degassing by the suction type vacuum generator 7 and opening the electromagnet valve 9, the supply shoe 5 is supplied with compressed air from the compressed air supply 10, and the inside of the supply shoe 5 is supplied. The pneumatic state of is in a higher state than the pneumatic state (b) described above. In Fig. 7, the air pressure inside the supply shoe is 0.8 atm higher than the air pressure state (b). When the air pressure inside the supply shoe 5 becomes higher than the air pressure state b lower than atmospheric pressure, the electromagnet valve 9 is closed again, and the suction type vacuum generator 7 has a state in which the inside of the supply shoe 5 is lower than atmospheric pressure ( b) to work. Then, the operation of the suction type vacuum generator 7 is stopped and the electromagnet valve 9 is opened so that compressed air is supplied into the supply shoe 5, whereby the state inside the supply shoe 5 becomes air pressure. The state (b) is changed to a higher air pressure state (c) than the air pressure state (b).

As described above, by means of the air tapping method, the air pressure state inside the supply shoe is repeatedly switched from a state (b) which is less than atmospheric pressure (b) to a state (c) higher than the state (b). The die cavity 3 formed of the lower punch 2 inserted therein can fill the powder P with uniform and high density. After the powder p is filled in the die cavity 3, the horizontal cylinder 12 moves to retract the piston rod 12a, whereby the feed shoe 5 is separated from the die cavity 3. To be relocated. At that time, an upper punch (not shown in the figure) is inserted into the die 1 and compacts the powder p filled in the die cavity 3 down to obtain a powder compact.

The conventional method of filling by gravity as well as air tapping has the problem that the filling amount changes with each filling, the filling density changes locally in the container, and at the same time the filling amount of each container is irregular when filling multiple containers. . In particular, when a cavity having a complex shape or a shallow ring shape is filled with powder by a filling method that does not use air tapping, the quality of the product is greatly degraded due to the irregularity of the cavity filling density.

Filling the container with material by applying air tapping prevents the problem as described above. However, in the conventional air tapping and apparatus described above, the supply shoe 5 is repeatedly switched by the air pressure state from the state (b) below the atmospheric pressure (b) to the state (c) higher than the state (b). The problem occurred when the internal air pressure was lower than atmospheric pressure. In other words, when the outside air of the die cavity 3 flows through the gap between the inner wall 1b of the die 1 and the outer wall 2a of the lower punch 2, it is filled in the die cavity 3. Powder (p) swells.

In addition, if the conventional air tapping method is used at the time of filling the rubber mold 17 shown in Fig. 3, the air pressure inside the rubber mold 17 becomes lower than atmospheric pressure when the low air pressure state is caused in the air tapping process, so that the rubber mold It was necessary to prevent the rubber mold from being deformed internally by means of bringing the outside of the to a low air pressure state. This prevention means complicates the structure of the device and makes the device expensive.

An object of the present invention is to solve the problems occurring in the conventional charging method and charging device.

1 is a vertical sectional view of a charging device embodying the present invention;

2 is an operational diagram showing the conversion of air pressure when the air tapping of the present invention is applied;

3 is a vertical sectional view of another charging device embodying the present invention;

4 is a vertical sectional view of another charging device embodying the present invention;

5 is a vertical sectional view of a conventional charging device;

6 is a vertical sectional view of another conventional charging device; And

7 is an operational diagram showing the switching of air pressure when conventional air tapping is applied.

* Explanation of symbols for the main parts of the drawings

1: die 2: lower punch

3: die cavity 4: table

5: supply shoe 6.8: pipe

9: electromagnet valve 10: compressed air supply

12: horizontal cylinder 12a: piston rod

13: pressure relief valve 14: pressure relief hole

In order to achieve the above-described object, in the present invention, the air tapping switches the air pressure state of the space including the container and the space portion connected to the container several times from the low air pressure state to the high air pressure state, and simultaneously A new charging method which is carried out to maintain a state higher than or equal to the atmospheric pressure outside the space, means for bringing the air pressure of the space into an air pressure state higher than the external atmospheric pressure of the space, and the space in the air pressure higher than atmospheric pressure Provided is a device comprising a means for bringing a pneumatic state to a state of low air pressure but above or equal to atmospheric pressure outside the space.

1 to 7, while specific embodiments of the present invention are discussed, the present invention is not limited to these embodiments and various modifications are possible within the scope of the present invention.

First, referring to FIGS. 1 and 2, in the embodiment, the compacted powder is filled in a die cavity, which is a filling space. Detailed descriptions of the parts correspond to those of the conventional charging device described above, and therefore, the descriptions thereof are omitted and denoted by the same reference numerals.

Similar to the conventional filling device described above, the pipe 8 attached to the outer wall of the protruding portion 5a of the supply shoe 5 is connected to the compressed air supply 10 via an electromagnet valve 9. Lose. The part 13 is a pressure relief valve attached to a pipe 6 which is connected to the outer wall of the supply shoe 5 protruding part 5a. The pressure relief valve 13 is designed to discharge the air inside the supply shoe 5 when the air pressure inside the supply shoe 5 becomes higher than some degree higher than atmospheric pressure. An air discharge hole 14 is formed in the wall of the protruding portion 5a of the supply shoe 5.

Similar to the conventional method, it is attached on the table 4 to fill the powder p in the die cavity 3 formed by the die 1 and the lower punch 2 inserted in the die 1. The supplied feed shoe 5 is moved by driving a horizontal cylinder 12 which moves the piston rod 12a until the feed shoe 5 is positioned on the die cavity 3 as shown in FIG. Lose. At that time, the powder stored in the supply shoe 5 falls into the die cavity 3.

Then, the electromagnet valve 9 supplies compressed air of the compressed air supply such that the air pressure inside the supply shoe 5 is in an air pressure state B0 of 1.3 atm higher than atmospheric pressure AO as shown in FIG. 2. It is opened to be fed into the shoe 5. If the air pressure supplied from the compressed air supply 10 to the supply shoe 5 exceeds the tolerance of the pressure relief valve 13, air is discharged to the pressure relief valve 13. At this time, the electromagnet valve 9 is closed to prevent the air from being supplied from the compressed air supply 10 to the supply shoe 5, and in the high air pressure BO, the air inside the supply shoe 5 is discharged from the air outlet hole ( 14), whereby the air pressure inside the supply shoe 5 drops to atmospheric pressure as shown by A1 in FIG. At this point, the electromagnet valve 9 is opened again so that compressed air is supplied from the compressed air supply 10 to the supply shoe 5, whereby the atmospheric pressure at which the air pressure inside the supply shoe 5 appears at A1. It becomes a higher air pressure state B1. Similar to the process described above, if the air pressure supplied from the compressed air supply 10 to the supply shoe 5 exceeds the tolerance of the pressure relief valve 13, air is discharged to the pressure relief valve 13. do. At this time, the electromagnet valve 9 is closed to prevent the supply of air from the compressed air supply 10 to the supply shoe into the supply shoe, and in the high air pressure state B1, the air inside the supply shoe 5 is air discharge hole 14 ), And the air pressure inside the supply shoe 5 drops to atmospheric pressure as shown by A2 in FIG.

As described so far, by the repetition of the air tapping in which the air pressure inside the supply shoe is higher than atmospheric pressure to the same state as the atmospheric pressure, the powder p is fed to the die 1 and the lower punch inserted therein ( It can be filled into the die cavity 3 formed of 2) evenly and with high density. After the powder p is filled into the die cavity 3, the horizontal cylinder 12 is moved to retract the piston rod 12a, whereby the feed shoe 5 is separated from the die cavity 3. Is relocated. At that time, an upper punch (not shown in the figure) is inserted into the die 1 and compresses the powder p filled in the die cavity 3 down to obtain a powder compact.

In this embodiment, air tapping is used to prevent atmospheric pressure outside the die cavity 3 from entering the die cavity 3 through the gap between the die inner wall 1b and the outer wall 2a of the lower punch 2. This is done by repeating the switching of the pneumatic state from the higher state to the atmospheric pressure state. Thus, the occurrence of the problem that the powder p is inflated by the air is prevented. In addition, the air tapping can be carried out by appropriately repeating the transition of the pneumatic state from the state above atmospheric pressure (high state) to the state below the high state but slightly above atmospheric pressure.

It is also possible to use an electromagnet valve instead of the pressure relief valve 13 and to remove the air vent 14 provided in the protruding portion 5a of the supply shoe 5. In this case, the air supplied from the compressed air supply 10 is discharged by the opening of the electromagnet valve replacing the air discharge hole 14 so that the air pressure inside the supply shoe 5 returns to atmospheric pressure.

As described above, by performing an air tapping process using an air pressure higher than atmospheric pressure around the die 1 and the lower punch 2, the air is transferred to the inner wall 1b and the lower punch 2 of the die 1; It does not enter into the die cavity 3 in the gap between the outer wall 2b of This does not cause the swelling problem of the powder p.

With reference to FIG. 3, an embodiment of the invention comprising a rubber mold and a cavity will now be described.

The lower punch 16 is inserted into the cylindrical die 15. The lower punch 16 includes a portion having a large diameter and a portion having a small diameter. Around this part, an internally protruding portion 15a of the die is provided to prevent the die 15 from sliding upward.

The rubber mold 17 is located in the space 18 formed by the inner wall of the die 15 and the outer wall of the lower punch 16. The outer diameter of the rubber mold 17 is about the same size as the inner diameter of the die 15. A backing ring 19 made of a synthetic resin is installed at the upper edge of the lower punch 16 to prevent the rubber mold from adhering between the die 15 and the lower punch 16. The lower punch 16 is installed on the support table 20 having the bolts 21 inserted into the holes 20a provided in the support table 20, and the bolts 21 are formed at the lower portion of the lower punch 16. It is installed in 16c). The lower portion of the lower punch 16 has a smaller diameter than the other portion provided with some flat spring that is inserted between the lower surface of the die 15 and the upper surface of the support table 20. The upper surface of the rubber mold 17 is designed to substantially coincide with the upper surface of the die 15.

The cylindrical guide element 23 is attached on the rubber mold 17 and the top surface of the die 15. The lower opening of the cylindrical guide 23 is provided with a grid element 24 comprising a parallel wire, a mesh, a plate with many holes or the like. Since such grid elements are disclosed in the applicant's KOKAIH-11-90694 patent application, only a brief description is given here. Powder p is injected into the cavity 17a of the rubber mold 17 through the grid element 24 while the air tapping process is performed. After the air tapping process is completed, when the grid element 24 functions to prevent the powder p from falling off the cylindrical guide element 23, the guide element is removed from the surface of the rubber mold 17 and the die 15. Raised

The portion indicated by " 25 " includes a body including a cylindrical portion 25a 'having a lower opening and a closed upper portion and a portion projecting horizontally from the lower portion of the cylindrical portion 25a', as well as the pipe 25d. An air-tapping device comprising a first electromagnet valve 25c connected to the cylindrical portion 25a 'and a second electromagnet valve 25e connected to the compressed air supply 25g via a pipe 25f.

The process by which the cavity 17a of the rubber mold 17 is filled with powder will now be described.

The cylindrical guide element 23 for loading the powder p is attached on the upper surface of the rubber mold 17 and the die 15, and the air-tapping device 25 is attached on the top of the cylindrical guide element. . When both the first electromagnet valve 25c and the second electromagnet valve 25e are closed, the compressed air supply 25g is operated. At that time, the second electromagnet valve 25e is opened to send compressed air from the compressed air supply 25g to the cylindrical guide element 23 and the inside of the cylindrical guide element 23 is in a high air pressure state higher than atmospheric pressure. Then, the second electromagnet valve 25e is closed and the first electromagnet valve is simultaneously opened to release the air in the high air pressure state so that the inside of the cylindrical guide element is brought to atmospheric pressure. After the inside of the cylindrical guide element is equal to atmospheric pressure, the first electromagnet valve 25c is closed. At that time, the second electromagnet valve 25e is reopened to send compressed air into the cylindrical guide element 23 and the inside of the cylindrical guide element 23 is in a high air pressure state higher than atmospheric pressure. At that time, the second electromagnet valve 25e is closed again and the first electromagnet valve 25c is opened to release the air in the high air pressure state so that the inside of the cylindrical guide element 23 returns to the atmospheric pressure state, at which time the first electromagnet valve 25c is closed. Through this air tapping process, the powder p of the cylindrical guide element 23 is injected into the cavity 17a of the rubber mold 17 through the grid element 24.

After the powder has been filled into the cavity 17a of the rubber mold 17 by air tapping, the cylindrical guide element 23 and the air-tapping device 25 are separated and the upper punch not shown in the drawing is the rubber mold 17 And attached to the top surface of the die 15 and down. While the upper punch is down, the die 15 is compressed down to suppress the elasticity of the flat spring provided between the die 15 and the support table 20. If the lower punch 16 supported by the support table 20 is not lowered, the depth of the space formed by the inner wall of the die 15 and the upper surface of the lower punch 16 is filled in the rubber mold 17. The powder p is internally compressed and reduced to decrease, thereby reducing the powder compact.

In the conventional filling method, the air tapping process was performed by alternately switching the internal pneumatic state of the cylindrical guide element 23 from the state lower than the atmospheric pressure b to the state c higher than the above state. In this case, when the air pressure inside the cavity 17a of the rubber mold 17 and the cylindrical guide element 23 is lower than atmospheric pressure, atmospheric air existing between the rubber mold 17 and the inner wall of the die 15 The rubber mold 17 was pushed in and the rubber mold 17 was deformed internally. In the present invention, since the air tapping process is performed by alternately switching the air pressure state inside the cylindrical guide element 23 from the state higher than atmospheric pressure to the same state as the atmospheric pressure, the outer wall of the rubber mold 17 has a cylindrical guide element. When the air pressure inside the 23 and the cavity 17a is higher than atmospheric pressure, it is compressed toward the inner wall of the die 15. Therefore, in the present invention, deformation of the rubber mold 17 does not occur, and a desired powder compact can be obtained.

As described so far, the conventional air tapping process of switching the air pressure state inside the cylindrical guide element 23 from the state lower than the atmospheric pressure (state b) to the state higher than the state (state c) is a rubber mold 17 Deformation occurred in the rubber mold 17 when the air pressure state inside the cavity 17a and the cylindrical guide element 23 of the C) became lower than atmospheric pressure (state b). In order to solve this problem, as disclosed in the prior patent application KOKAIH-9-78103, the atmospheric air existing between the rubber mold 17 and the die 15, the rubber mold 17 is a die 15 and rubber The negative pressure generated between the molds 17 had to be absorbed to adhere to the die 15. However, in the present invention, the means for generating the negative pressure is no longer needed because the air tapping is carried out by repeatedly switching from a higher than atmospheric pressure to an equivalent to atmospheric pressure. This simplifies the device structure.

In addition, the powder p is inflated by atmospheric air flowing into the cylindrical guide element 23 through a gap between the upper surface of the die 15 and the rubber mold 17 and the lower surface of the cylindrical guide element 23. Unlike the filling method of, the present invention prevents the powder from swelling.

An embodiment of the present invention in which the bag fills powder, granular material and materials of that kind is described below with reference to FIG.

The bag holding container 26 is open at the top, and the bag 27 is located in the bag holding container 26. The opening fringe 27a of the bag 27 is placed on the upper surface of the bag holding container 26. The cylindrical guide element is attached on the top of the bag holding container 26.

In this embodiment, the air tapping device 25 'is a main body 25h including an upper portion of which the bottom is opened and a through hole 25h' is provided, and a first of which is connected to the side wall of the main body through a pipe 25i. Compressed air supply 25p connected to electromagnet valve 25j, second electromagnet valve 25m connected to first electromagnet valve 25j through pipe 25k, and second valve 25m via pipe 25n. ).

The bag 27 is placed in the bag holding container 26 and the fringe 27a of the bag opening is placed on the top surface of the bag holding container 26 and the cylindrical guide element 28 is placed on the top of the bag holding container 26. It is attached on the face. Then, an amount of a portion of the powder p is injected to fill a portion of the bag 27 and the cylindrical guide element 28. At that time, the air tapping device 25 ′ is attached to cover the upper opening of the cylindrical guide element 28.

Then, when the second electromagnet valve 25m is opened and the first electromagnet valve 25j is closed, the compressed air supply 25p is operated. At this time, the second electromagnet valve 25m is provided from a compressed air supply 25p in which compressed air having a pressure higher than atmospheric pressure is included in the pipe 25k between the first electromagnet valve 25j and the second electromagnet valve 25m. It is closed to supply. At that time, the first electromagnet valve 25j is together with the second electromagnet valve 25m closed between the first electromagnet valves 25j such that the air contained in the pipe 25k flows to the air-tagging apparatus 25 '. It is opened, and the air pressure state in the cylindrical guide element 28 becomes a high air pressure state higher than atmospheric pressure. Then, the compressed air flowing to the cylindrical guide element 28 is discharged to the through hole 25h 'provided at the top of the body 25h, whereby the air pressure state in the cylindrical guide element 28 is returned to the atmospheric pressure state. Goes.

By performing the air tapping which alternates the air pressure state from the high air pressure state higher than atmospheric pressure to the atmospheric pressure state, the powder p injected into the cylindrical guide element 28 as well as the bag 27 is filled in the bag 27. Lose.

Similar to the previous embodiment, in this embodiment, air tapping is performed by alternately switching from the high air pressure state where the air pressure state is higher than atmospheric pressure to the atmospheric pressure state. The powder p injected into the cylindrical guide element 28 as well as the bag 27 is filled in the bag 27. The swelling problem caused by the flow of atmospheric air into the gap between the bag holding container 26 and the cylindrical guide element 28 in the cylindrical guide element 28 can thereby be prevented.

The powder p is applied to the bag 27 by a conventional filling method in which air tapping is performed by switching the air pressure state from a low air pressure state b lower than atmospheric pressure to a high air pressure state c higher than the state b. The problem arises when it is filled and the air pressure state inside the cylindrical guide element 28 and the bag 27 becomes a low air pressure state b lower than atmospheric pressure. In other words, the bag 27 is deformed internally by the flow of atmospheric air existing between the bag 27 and the bag holding container 26. According to the present invention, since the bag 27 is attached to the inner wall of the bag holding container 26 close to the inner wall of the bag holding container 26 by applying the air tapping to convert the air pressure state from the high air pressure state higher than atmospheric pressure to the atmospheric pressure state, the bag 27 is deformed. This does not occur.

As described above, the present invention allows the material to be evenly filled in the container. This effect can also be obtained by performing the following processing. The container loads the material by another filling method or conventional filling method, and has the same structure as the above-described supply shoe, but does not load the material to be filled (the shoe is a "cover shoe" below). The cover shoe is then subjected to a cycle of switching the air pressure state inside the cover shoe from a high air pressure state to a low air pressure state, and at the same time equals the air pressure outside the container (generally, atmospheric pressure). To maintain a higher or higher air pressure. This ensures that the material is filled evenly in the container with little scattering of the filling amount during each filling. Although this treatment has disadvantages in productivity compared to the method of simultaneously feeding and filling using a feed shoe that preloads the material, an air tapping method using a cover shoe is preferably used in the following cases. Can be.

When a container with a complex shape or shallow ring shape needs to be filled with powder that is accurately controlled in load and dimension, the powder is fed into the die cavity and weighed with a weighing device according to the amount to be filled. At this stage, the filling density in the die cavity is very irregular. The cover shoe is then attached on the top opening of the die cavity and subjected to air tapping. This treatment allows the powder to be filled in each corner of a complex shaped die cavity or in the circumferential wall of a shallow ring shaped cavity with great homogeneity as well as weight accuracy. Unlike the conventional air tapping method, in which the amount of powder to be filled by swelling the powder is changed, the air tapping method of the present invention does not change the amount of powder at all. Thus, complex shapes or shallow ring shaped powder compacts in which weight and shape are precisely controlled can also be produced by the present invention.

If the filled material is flammable powder or the like, the air used for tapping the air may be an inert gas such as nitrogen gas or argon gas. The air mentioned in the above embodiment is not limited to atmospheric air and may include an inert gas including nitrogen gas and argon gas.

As described so far, the present invention has the following effects.

Since the air tapping process is carried out at an air pressure equal to or higher than the atmospheric pressure, the problem that the material filled in the space is inflated by the flow of external atmospheric air in the space does not occur.

The apparatus of the present invention eliminates the need for means to prevent vessel deformation since the air tapping process is performed while maintaining an air pressure equal to or higher than atmospheric pressure. So the structure of the device can be simplified.

Claims (5)

A filling method for filling a material into a container by an air tapping process which alternates the pneumatic state of the space in which the material is loaded, including the container and the space portion connected to the container, from the low air pressure state to the high air pressure state. And said low air pressure state in said air tapping process is higher than or equal to atmospheric pressure outside the space. Connecting a container comprising a supply shoe into which material is loaded and a cavity into which the material is filled; And The supply shoe having the material is alternately switched from a low air pressure state to a high air pressure state while at the same time, an air tapping process for maintaining the low air pressure state above or equal to the atmospheric pressure of the outer space of the container. Including steps The filling method is characterized in that the material is filled into the container. Attaching a cover shoe onto a container comprising a cavity previously supplied with material; And Switching the cover shoe from the low air pressure state to the high air pressure state alternately, and simultaneously performing an air tapping process to maintain the low air pressure state higher than or equal to the atmospheric pressure of the outer space of the container. and, The filling method is characterized in that the material is filled into the container. A supply shoe for temporarily storing a material to be filled in the container and covering the opening of the container; Means for attaching the supply shoe to bring the air pressure inside the supply shoe into a high air pressure state higher than the atmospheric pressure in the outer space of the container; And Means for equalizing the charge, characterized in that it is attached to the supply shoe and has an air pressure state inside the supply shoe lower than the high air pressure state but higher than or equal to the atmospheric pressure of the outer space of the container. Charging device. A cover shoe covering the opening of the container; Means for attaching to the cover shoe and bringing the air pressure inside the cover shoe into a high air pressure state higher than the atmospheric pressure in the outer space of the container; And And means for adhering to the cover shoe and bringing the air pressure inside the cover shoe into a low air pressure state that is lower than the high air pressure state but higher than or equal to the atmospheric pressure of the outer space of the container. Charging device.