JP2007061881A - Metallic screw lid working method, and metallic screw lid formed by the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metallic screw lid working method capable of forming the thread at a pitch wider than 8 ridges/inch, e.g., 6 ridges/inch; and also to provide a metallic screw lid formed by the method. <P>SOLUTION: In the metallic screw lid working method, a thread is formed in a curved portion by pressing a screw form against the curved portion in which a metallic plate is bent inward of a lid. The thread has 6 ridges/inch, and the ratio of the radius of curvature obtained by dividing the radius of curvature of a ridge tip portion of the screw form by the radius of curvature of a ridge intermediate portion is smaller than the thread of 8 ridges/inch. In other words, the thread is 6 ridges/inch, and the steepness of each thread of the screw form is higher than the thread of 8 ridges/inch. Further, the thickness of the curved portion to the lid diameter direction is set to be larger than the thread of 8 ridges/inch. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for processing a metal screw cap and a metal screw cap formed by this processing method. More specifically, a metal screw lid processing method for forming a screw thread in a curved portion by press-contacting a screw mold to a curved portion obtained by bending a metal plate material toward the inside of the lid, and a metal screw formed by this processing method It relates to a screw cap.

As a method for processing a metal screw lid and a metal screw lid formed by this processing method, for example, the one described in the following Patent Document 1 is known.
Noto 3085619

  According to this publication, a process is shown in which a bent portion is formed by bending a sheet metal, and a screw thread is formed on the bent portion by press-contacting a screw mold to the portion.

  By the way, in forming the screw thread in the above-mentioned process, it was a limit to form a screw thread of 8 threads / 1 inch from the characteristics of a metal plate such as a steel plate or an aluminum plate. Even if the screw mold is pressed against the curved portion to form a wider pitch, that is, for example, 6 threads / 1 inch thread, the curved portion cannot withstand the pressing force, and the screw has a sufficient depth. The part could not be formed.

  In particular, in the glass bottle industry, 6 threads / 1 inch thread is standard, but for metal screw caps, 8 threads / 1 inch is the limit, so as long as a metal screw cap is used, the glass bottle must be customized. However, there has been a strong demand for a method for processing a metal screw cap that can form a thread of 6 threads / 1 inch.

  In view of such a conventional situation, the present invention provides a method for processing a metal screw cap capable of forming a thread having a pitch wider than 8 threads / 1 inch, for example, 6 threads / 1 inch, and this processing method. An object is to provide a formed metal screw cap.

In order to achieve the above object, the metal screw lid processing method according to the present invention is characterized by forming a screw thread in the curved portion by pressing the screw mold against the curved portion obtained by bending the metal plate toward the inside of the lid. A way to
The screw thread is 6 threads / 1 inch, and the curvature radius ratio obtained by dividing the radius of curvature of the thread tip of the screw type by the radius of curvature of the middle part of the thread is 8 threads / 1 inch. There is also in making it small.

Another feature of the method for processing a metal screw lid according to the present invention is a method of forming a screw thread in a curved portion by pressing a screw die against a curved portion obtained by bending a metal plate material toward the inside of the lid. ,
The thread is 6 threads / 1 inch, and the kurtosis of each thread of the screw type is higher than the thread of 8 threads / 1 inch.

In each of the above features, the thickness of the curved portion with respect to the lid diameter method may be larger than a thread of 8 threads / 1 inch.
A metal screw cap formed by any of the processing methods described above also forms part of the present invention.

According to the above-described method for processing a metal screw lid according to the present invention and the feature of the metal screw lid formed by this processing method, a thread having a pitch wider than 8 threads / 1 inch, for example, 6 threads / 1 inch, is provided. It became possible to form. As a result, the industry standard 6-cylinder / 1-inch glass bottle can be used, and a great contribution can be made in terms of effective utilization of standard resources different from simple design changes.
Other objects, configurations, and effects of the present invention will become apparent from the following embodiments of the present invention.

Next, the present invention will be described in more detail with reference to the accompanying drawings as appropriate.
As shown in FIGS. 1 to 4, the metal screw cap 1 according to the present invention is used together with a glass bottle 30. The metal screw cover 1 is obtained by bending a cover material 1a by sheet metal processing as shown in FIG. For example, a steel plate having a thickness of about 0.22 to 0.23 mm is used for the lid member 1a. The plate thickness is not limited to this value, and a metal plate such as an aluminum plate may be used. The metal screw cap 1 has a disk-shaped top portion 2 and a side portion 3 continuous vertically around the top portion 2. A curved portion 4 is folded inside the side portion 3, and a screw thread 10 and a valley portion 11 are formed in the curved portion 4. A packing 20 is provided on the inner surface of the top portion 2.

  The glass bottle 30 has a bottle thread 32 at its mouth 31. The bottle thread 32 is formed as a standard pitch of 6 threads / 1 inch, and the thread 10 of the metal screw lid 1 is screwed together. 6 threads / 1 inch means that 6 threads are formed in a width of 1 inch. The 6-thread / 1-inch screw in the lid and the bottle does not necessarily have to be formed continuously, and may be an intermittent screw.

  FIG. 3 (a) shows a partial cross section of a screw mold 50 used at the time of forming a screw in the present invention. The mold 50 has a top 51 that forms the valley 11 by pressing and a thread 10 portion. And a corresponding valley portion 53. The first curvature radius Ra of the top portion 51 is 1.5 mm, and the second curvature radius Rb of the middle portion 52 of the screw thread of the mold is set to 2.5 mm.

  On the other hand, FIG. 3 (b) shows a partial cross section of a screw mold 50 used when forming an 8-thread / 1-inch screw, and this mold 50 has a top 51 ′ that forms the valley 11 by pressing. And a trough portion 53 ′ corresponding to the thread 10 portion. The first radius of curvature Ra 'of the top 51' is 1.5 mm, and the second radius of curvature Rb 'of the middle portion 52' of the mold thread is set to 2.0 mm.

  According to the configuration of the mold 50, in the case of 6 threads / 1 inch thread, the curvature radius ratio obtained by dividing the radius of curvature Ra of the thread tip of the thread mold by the radius of curvature Rb of the middle portion of the thread. (Ra / Rb) is smaller than the radius-of-curvature ratio (Ra ′ / Rb ′) of 8 threads / 1 inch thread. In other words, a thread of 6 threads / 1 inch can be said to have a higher kurtosis of each thread of the thread type than a thread of 8 threads / 1 inch.

  Next, the thread forming process of FIG. 4 will be described. First, a disk-shaped lid 1a is formed in a cylindrical shape with the top 2 as the bottom as shown in FIG. 5A, and a turn 1b is formed around the periphery as shown in FIG. The bent portion 1c is formed by further bending as shown in FIG. Next, the bush 1d is added to the lower portion of the curved portion 1c, and the mold 50 is pressed against the curved portion 1c from the inner surface to form the above-described thread 10 in the curved portion 1c (4).

  Here, conventionally, in the mold in which the mold of the mold 50 ′ is enlarged in a similar shape to 6 threads / 1 inch, it is not possible to form the screw threads 10 and the valley portions 11 with sufficient depth. . Therefore, the metal plate of the curved portion 4 is sufficiently bent by setting the mold 50 to a screw thread having a sharpness higher than that of the eight threads / one inch thread with the setting as described above in the curvature radius. Thus, it is possible to form the thread 10 and the valley 11 having a sufficient depth. Furthermore, by increasing the thickness of the curved portion 4 in the lid diameter direction to 3.2-4.0 mm, which was conventionally about 2.8-3.0 mm, the screw thread 10 and the valley portion have a further sufficient depth. 11 can be formed.

  The present invention relates to a method for processing a metal screw cap capable of forming a thread having a pitch wider than 8 threads / 1 inch, for example, 6 threads / 1 inch, and a metal screw cover formed by this processing method. Can be used. In addition, the present invention can be suitably applied to a glass bottle, and can also be used as a lid for a metal bottle or a resin bottle.

It is sectional drawing of the glass bottle in which the metal screw lids were screwed together. It is the A section partial enlarged view of FIG. It is a fragmentary sectional view of a metal mold | die, (a) is this invention, (b) is used for a cover of 8 ridges / 1 inch, respectively. It is sectional drawing which shows the process process of a lid | cover.

Explanation of symbols

1: Metal screw cover, 1a: Cover material, 2: Top part, 3: Side part, 4: Curved part, 10: Screw thread, 11: Valley part, 20: Packing, 30: Glass bottle, 31: Mouth part, 32 : Bottle screw thread, 50: mold, 51: top part, 52: intermediate part, 53: valley part, Ra: first radius of curvature, Rb: second radius of curvature

Claims (4)

A metal screw lid processing method for forming a screw thread in a curved portion by press-contacting a screw mold to a curved portion obtained by bending a metal plate material toward the inside of the lid,
The thread is 6 threads / 1 inch, and the radius of curvature obtained by dividing the radius of curvature of the thread tip of the screw type by the curvature radius of the middle part of the thread is 8 threads / 1 inch. A method for processing a metal screw cap, which is smaller than the above. A metal screw lid processing method for forming a screw thread in a curved portion by press-contacting a screw mold to a curved portion obtained by bending a metal plate material toward the inside of the lid,
A method of processing a metal screw cap, wherein the thread is 6 threads / 1 inch, and the kurtosis of each thread of the screw mold is higher than 8 threads / 1 inch. 3. The method for processing a metal screw lid according to claim 1, wherein the thickness of the curved portion with respect to the lid diameter method is larger than a thread of 8 threads / 1 inch. A metal screw cap formed by the processing method according to claim 1.

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