JPS6121372Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the structure of a cap formed by curling in a pressure vessel such as an aluminum mini-barrel.

For example, in an aluminum mini keg for draft beer, a cap 3 is formed by curling on a funnel-shaped upper body 2 which is caulked and fixed to a lower body 1 as shown in FIG. The cap 3 is formed by pressing the upper body 2, and generally, as shown in FIG. 5, and then burring the outer ring part 5 so that it is coextensive with the cylindrical part 4, and then the cylindrical part 4' formed including the outer ring part 5 in this way. It is formed by curling the tip of the tip outward. Since a lip cap (not shown) is then attached to the thus formed cap 3 by caulking, it is important that the cap 3 is not deformed by the crimping force of the lip cap and does not impair its sealing performance.

For this purpose, conventionally, the end edge 4'A of the tip portion to be curled by the curling process was brought into active contact with the base of the mouthpiece, that is, the outer surface of the cylindrical portion 4'.
In other words, this contact increases the strength of the curled portion.

However, when this type of pressure vessel is surface-treated by electrolytic treatment, dipping treatment, etc., the treatment liquid that has entered the inside of the curled portion of the mouthpiece 3 cannot be easily and completely discharged. For this reason, it is difficult to avoid problems such as the processing liquid flowing out from inside the curl and causing stains during subsequent processing. In addition, a relatively long time was required to discharge the processing liquid.

An object of the present invention is to provide a cap structure that can easily and completely discharge the processing liquid that has entered the curl interior space.

For this purpose, the cap structure of the present invention is such that a notch is formed with a gap in the tip edge to be curled, and in the state after the curling process, the notch forms an opening that communicates the curl internal space with the outside. It is characterized by being configured as follows.

Examples will be described below with reference to FIGS. 3 to 6.

The feature of the cap 10 of this embodiment (see FIGS. 3 and 6) is that the cylindrical portion 4' is curled.
A notch 5A is formed with a gap in the tip 4'A of the curl, and when the tip 4'A is in contact with the outer surface of the cylindrical part 4', the notch 5A communicates between the curl internal space and the outside. This is because an opening is formed to Such a cap 10 is attached to an upper body 2 as shown in FIG.
When punching is performed while leaving the outer ring part 5 on the top wall of the cylindrical part 4 formed on the top wall of the cylinder, a notch 5A as shown in FIG. 5 is simultaneously formed in the outer ring part 5. Can be done. That is, this can be achieved by providing a punch for punching the top wall and a processing section for the notch 5A. The outer ring part 5 having the notches 5A formed therein is then burred in the same direction as the cylindrical part 4 as shown in FIG. 6 to form a cylindrical part 4' including the outer ring part 5, and then curled. The tip portion is curled outward to form a cap 10 as shown in FIG. This molding process is the same as the conventional one.

Here, as shown in FIG. 5, this base 10 is 1/4
Four notches 5A are formed in the outer ring portion 5 at circumferential positions, but the number and positions thereof are arbitrary. Similarly, the notch 5A can be formed by means other than those described above.

According to the cap having the notch in the tip edge as described above, the curl internal space is communicated with the outside through the opening formed by the notch, and the processing liquid can be discharged extremely easily and completely. Further, since the tip edge is in contact with the base of the cap, that is, the surface of the cylindrical portion except for the area of the notch, it has sufficient strength to withstand the caulking force of the lip cap, so that the sealing performance etc. is not impaired. Furthermore, the notches allow active surface treatment of the inner surface of the curl, resulting in improved product quality. Many effects such as those mentioned above can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing a product having a cap structure according to an embodiment of the present invention. FIG. 2 is a sectional view showing a method of processing the upper body in FIG. 1. FIG. 3 is a partially enlarged sectional view showing the features of the base structure of the present invention. FIG. 4 is a sectional view showing the step of forming the notch shown in FIG. 3; FIG. 5 is a top view showing the notch.
FIG. 6 is a sectional view showing the stages of burring and curling. 2... Upper body, 3, 10... Base, 4, 4'
...Cylindrical part, 5...Outer ring part, 5A...Notch.

Claims (1)

[Scope of utility model registration request] In a cap formed by curling in a pressure vessel, a notch is formed with a gap along the tip edge to be curled, and when the tip edge is in contact with the base of the cap due to curling, the notch is formed in the curl internal space. A cap structure for a pressure vessel characterized by forming an opening that communicates with the outside.