JP7231214B2 - Corrosion prevention treatment method for seamed portion of metal square can and metal square can - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rust prevention treatment method for a seamed portion of a metal square can and to a metal square can.

Conventionally, metal square cans such as 18-liter cans are formed by joining one end of a rectangular metal plate to the other end to form a square tubular can body, and then connecting the top plate and the bottom plate. It is assembled by seaming the top and bottom ends of the can body. In this type of square can, the seam portions on the top plate side and the bottom plate side are subjected to antirust treatment. Spraying, brush coating, dip coating, and the like are known as methods for anticorrosive treatment of the seamed portion (see, for example, paragraph 0015 of Patent Document 1).

JP-A-6-47339

However, since the anticorrosive liquid is sprayed in the form of a mist, the anticorrosive liquid tends to diffuse not only to the seamed portion but also to the surrounding area, and there is a problem that it is difficult to apply the anticorrosive liquid evenly to the seamed portion. In addition, since the rust preventive liquid tends to diffuse to the surroundings, there is also a problem that the utilization efficiency of the rust preventive liquid is low (a lot of the rust preventive liquid is wasted). In the case of brush coating, uneven coating due to air bubbles and the like has been a problem. Furthermore, dip coating requires a large-scale facility such as a dip treatment line having a dipping bath, etc., in addition to a normal manufacturing and transport line, which causes a problem of increased cost.

It is a technical object of the present invention to provide a method for rust-proofing the seamed portion of a metal square can and a metal square can that have been improved in consideration of the above-described current situation.

The invention of the present application is a method for rust-proofing a seam portion of a metal square can transported by a transport conveyor, wherein heating members arranged on both sides of the transport conveyor cover the seam portion. The outer peripheral side including the hook radius is heated, and the rust preventive liquid discharged from nozzles arranged on both sides of the conveying conveyor and downstream of the heating member is applied from the outside of the metal square can . It is applied by flowing down toward the cover hook radius of the tightening part.

In the rust preventive treatment method of the present invention, the rust preventive liquid dripping from the seam portion may be collected in a collection tray disposed below the nozzle for reuse.

Further, in the rust prevention treatment method of the present invention, the seam tightening portion may be wiped by a wiping member disposed downstream of the nozzle and on the collection tray.

Furthermore, in the rust preventive treatment method of the present invention, the seam portion may be heated by a heating member before the rust preventive liquid is flowed down and applied to the seam portion.

The present invention also includes a metal square can in which the seam portion is treated for rust prevention by the above method.

According to the invention of the present application, since the rust preventive liquid from the nozzle is applied by flowing down toward the cover hook radius of the seam portion, the rust preventive liquid can be evenly, accurately and efficiently applied to the seam portion. In particular, according to the present invention, it is possible to cause the antirust liquid to enter between the cover hook and the can body at the seam portion by capillary action. Therefore, the effect of preventing the occurrence of rust from the seamed portion is extremely high. In addition, according to the present invention, although the anticorrosive liquid can be applied to the seam portion as accurately and efficiently as unevenly as dip coating, large-scale equipment such as dip coating is not required. Cost can be reduced.

1 is a schematic perspective view showing an embodiment of the present invention; FIG. It is a schematic perspective view which shows a conveyance conveyor and an anticorrosive processing apparatus. It is a perspective view of a metal square can. FIG. 4 is an enlarged cross-sectional view showing the relationship between the seam portion and the nozzle; It is an enlarged plan view showing the joint of the can body, (a) is a view in which the joint is welded, and (b) is a view in which the joint is soldered.

Embodiments of the present invention will be described below with reference to the drawings. The rust preventive treatment apparatus 10 of the embodiment is provided in a part of a square can manufacturing line 1 for manufacturing metal square cans 20 such as 18-liter cans. A square can production line 1 is provided with a conveyer 2 for carrying a plurality of square cans 20 arranged in a row. On the transport conveyor 2, a plurality of square cans 20 are arranged in a row at predetermined pitch intervals and transported from the upstream side to the downstream side. The transport conveyor 2 of the embodiment is a chain conveyor. Note that the type of the transport conveyor 2 is not particularly limited.

The square can 20 has a conventionally well-known shape. One end of a rectangular metal plate is joined to the other end to form a square tubular can body 21, and then a top plate 22 is formed. It is assembled by seaming the main plate 23 to both upper and lower ends of the can body 21 (see FIGS. 3 and 4). Here, in the drawings of the embodiment, for convenience of explanation, the winding portion on the top plate 22 side facing the upstream side on the conveying conveyor 2 is the top plate side first winding portion 24a, and the winding portion on the main plate 23 side is the main plate. Referred to as the side first seam tightening portion 25a, the top plate side second seam tightening portion 24b, the bottom plate side second seam tightening portion 25b, and the top plate side third seam tightening portion 24b in counterclockwise order in FIG. They are referred to as the portion 24c, the bottom plate side third seam tightening portion 25c, the top plate side fourth seam tightening portion 24d, and the bottom plate side fourth seam tightening portion 25d. Therefore, in FIG. 1, the second seam portions 24b, 25b and the fourth seam portions 24d, 25d face the left and right outer sides of the conveyor 2, and the third seam portions 24c, 25c face the downstream side of the conveyor 2. (direction of travel). In addition, in the following description, they may be collectively referred to as "winding portions 24 and 25".

As shown in FIGS. 1 and 2, anticorrosive treatment devices 10 are arranged on both sides of the transport conveyor 2 . The antirust treatment apparatus 10 includes a nozzle 11 for applying an antirust solution 3 to the seam portions 24 and 25 of the square cans 20 on the conveying conveyor 2 , a collection tray 12 arranged below the nozzle 11 , and a nozzle 11 downstream of the nozzle 11 . and a wiping member 13 disposed on the side and on the collection tray 12 .

In the embodiment shown in FIGS. 1, 2 and 4, the opening end of each nozzle 11 is the cover of the bottom side second seam portion 25b or the bottom side fourth seam portion 25d of the square can 20 on the conveyor 2. It faces the hook radius 26. Therefore, the rust preventive liquid 3 discharged from the nozzle 11 flows down toward the cover hook radius 26 of the second base plate side seam portion 25b or the fourth base plate side seam portion 25d. 25b or the outer peripheral side of the fourth seam portion 25d on the main plate side (where the cover hook radius 26, the seaming wall radius 27 and the seaming wall radius 28 are located).

Further, in this case, the antirust liquid 3 can enter between the cover hook 29 and the can body 21 at the seam portions 24 and 25 by capillary action (see FIG. 4). Therefore, the effect of preventing the generation of rust from the seamed portions 24 and 25 is extremely high. Furthermore, since the antirust liquid 3 is caused to flow down from the nozzle 11 toward the cover hook radius 26 of the seam portions 24 and 25, four corner portions 31 of the seam portions 24 and 25 (can The portion corresponding to the joint portion 30 of the barrel 21) is also sufficiently coated with the rust preventive liquid 3 (see FIGS. 5(a) and 5(b)). The antirust liquid 3 from the nozzle 11 may be configured to always flow down, or may be configured to flow down intermittently according to the arrival of the square can 20 .

Although detailed illustration is omitted, the nozzle 11 is communicatively connected to a storage tank that stores the antirust liquid 3 via a supply pipe line. A supply pump for supplying the antirust liquid 3 in the storage tank to the nozzle 11 is arranged in the supply pipe. The collection tray 12 is connected to the storage tank via a return line. That is, the storage tank, the supply line, the nozzle 11, the collection tray 12 and the return line form a closed circuit in which the antirust liquid 3 can be circulated. The antirust liquid 3 dripping down from the bottom plate side second seam portion 25b and the bottom plate side fourth seam portion 25d is recovered in the recovery tray 12 and returned to the storage tank. Therefore, the surplus rust preventive liquid 3 can be returned to the storage tank and applied to the seam tightening portions 24 and 25 again (reusable). Therefore, the utilization efficiency of the antirust liquid 3 can be improved (waste of the antirust liquid 3 can be reduced).

As described above, the wiping member 13 is arranged downstream of the nozzle 11 and above the collection tray 12 . The wiping member 13 is provided with a brush, a sponge, a cloth, or the like, and in the embodiment, it is attached to the outer peripheral side (cover hook radius 26, seaming wall 27 and the seaming wall radius 28), and is configured to wipe those places. Therefore, the rust preventive liquid 3 evenly falling on the outer peripheral side of the second base plate side seam portion 25b or the fourth base plate side seam portion 25d is evened so as to be familiar with the portion, and the rust preventive liquid 3 is evenly distributed. The surplus will be dropped on the collection tray 12 .

Heating members 14 are arranged on both sides of the transport conveyor 2 on the upstream side of the pair of antirust treatment devices 10 . By heating the outer peripheral side of the second base plate side seam portion 25b and the fourth base plate side seam portion 25d with the heating member 14 before the anticorrosive liquid 3 is applied, the foreign matter is removed and cleaned from the portion. be. Further, since the portion is preheated, the adhesion of the antirust liquid 3 to the portion is also improved. The type of heating member 14 may be, for example, a gas burner or an electric heater, and is not particularly limited.

The embodiment shown in FIGS. 1 and 2 is a configuration for applying the antirust liquid 3 to the outer peripheral side of the second base plate side seam portion 25b and the fourth base plate side seam portion 25d. Although detailed illustration is omitted, on the downstream side of the pair of anticorrosive treatment devices 10, there are a rotating device for rotating the square can 20 by 90° in a plan view, a pair of heating members 14, a pair of antirust treatment devices 10, A reversing device for reversing the square can 20 upside down, a pair of heating members 14, a pair of antirust treatment devices 10, a rotating device, a pair of heating members 14, and a pair of antirust treatment devices 10 are arranged in order from the upstream side. there is Needless to say, the configuration and operation of the heating device 14 and the rust prevention treatment device 10 located downstream of the pair of rust prevention treatment devices 10 shown in FIGS. 1 and 2 are the same as those described above. Common symbols are attached.

In the above-described configuration, the square can 20 on the conveyer 2 is first heated by a pair of heating devices 14 to heat the outer peripheral side of the bottom plate side second seam portion 25b and the bottom plate side fourth seam portion 25d. Clean the area and apply preheat to the area. Next, the anticorrosive liquid 3 is evenly sprinkled on the outer peripheral side of the second base plate side seam portion 25b and the fourth base plate side seam portion 25d by the pair of anticorrosive treatment devices 10 to evenly distribute them. After that, the square can 20 is rotated by 90° in a plan view with a rotating device so that the outer peripheral sides of the first base plate side seaming portion 25a and the third base side seaming portion 25c face the left and right sides of the conveyer 2. Then, the pair of heating devices 14 heat the outer peripheral sides of the first base plate side seam portion 25a and the third base plate side seam portion 25c, and then the pair of rust prevention treatment devices 10 heat the first base plate side seam portion 25a. The anticorrosive liquid 3 is sprinkled evenly on the outer peripheral side of the third seam part 25c on the main plate side to make it uniform.

Next, the rectangular can 20 is turned upside down by a reversing device so that the outer peripheral side of the top plate side first seam portion 24a and the top plate side third seam portion 24c face the left and right sides of the conveyer 2, and then the heating device. 14 pairs heat the outer peripheral side of the top plate side first seam portion 24a and the top plate side third seam portion 24c, and then the pair of the rust prevention treatment device 10 heats the top plate side first seam portion 24a and the top plate side third seam portion 24c. The antirust liquid 3 is sprinkled evenly on the outer peripheral side of the third seam part 24c on the top plate side to make it uniform. Then, the square can is rotated by 90° in a plan view with a rotating device so that the outer peripheral sides of the top plate side second seam portion 24b and the top plate side fourth seam portion 24d face the left and right sides of the conveyer 2, The pair of heating devices 14 heat the outer peripheral side of the top plate side second seam portion 24b and the top plate side fourth seam portion 24d, and then the pair of the rust prevention treatment devices 10 heat the top plate side second seam portion. 24b and the outer peripheral side of the fourth seam portion 24d on the top plate side are evenly sprinkled with the antirust liquid 3 to evenly distribute them. All of the seam portions 24, 25 on the top plate side and the bottom plate side are subjected to the rust prevention treatment by the above steps.

As is clear from the above, according to the embodiment, the anticorrosive liquid 3 from the nozzle 11 is applied by flowing down toward the cover hook radius 26 of the seam tightening portions 24 and 25, so that the coating can be applied evenly, accurately and efficiently. The antirust liquid 3 can be applied to the seam portions 24 and 25 well. In particular, in the embodiment, the antirust liquid 3 can enter between the cover hook 29 and the can body 21 at the seam portions 24 and 25 by capillary action. Therefore, the effect of preventing the generation of rust from the seamed portions 24 and 25 is extremely high. Further, according to the embodiment, although the anticorrosive liquid 3 can be applied to the seam portions 24 and 25 accurately and efficiently as uniformly as dip coating, a large-scale facility such as dip coating is required. It is not necessary, and the cost can be reduced.

The configuration of each part in the present invention is not limited to the illustrated embodiment, and various modifications are possible without departing from the gist of the present invention. For example, metal square cans are not limited to 18-liter cans. A rotating device for rotating the square can 20 by 90° in plan view may be composed of a stopper and a guide rail, or may be of a magnet type. A reversing device for reversing the square can 20 upside down may be a magnet type or a cross spring wheel type. The configuration is not particularly limited as long as each function can be exhibited. The antirust liquid 3 may be either oily or water-based.

2 Conveyor 3 Antirust liquid 10 Antirust treatment device 11 Nozzle 12 Collection tray 13 Wiping member 14 Heating member 20 Square can 21 Can body 24, 25 Winding part 26 Cover hook radius 27 Seaming wall 28 Seaming wall radius 29 cover hook

Claims (2)

A method for rust-proofing the seamed portion of a metal square can conveyed by a conveyer, comprising:
Heating the outer peripheral side including the cover hook radius of the seam tightening portion with heating members arranged on both sides of the conveying conveyor,
The anticorrosive liquid discharged from nozzles arranged on both sides of the conveyer and downstream of the heating member flows downward from the outside of the metal square can toward the cover hook radius of the seaming portion. to apply,
A rust-proofing treatment method for the seamed portion of a metal square can. The seam portion is subjected to rust prevention treatment by the method according to claim 1,
metal canister.

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