JPS6264441A - Forming method for cleavage part in container cover - Google Patents

Abstract

PURPOSE:To increase the quality of a product and the productivity by forming a thin vertical wall part on the rising part of the vertical wall part formed by a drawing and by performing the bending of the vertical wall part and buckling of the thin vertical wall part with the pushdown of a panel face part as well. CONSTITUTION:A vertical wall part 2 is formed by executing a drawing on a cover blank plate 1. A shallow drawing is performed for the rising part 5 of the vertical wall part 2 formed in the first stage. The shallow drawing is performed by minutely crossing the lower side die 6 and upper side die 7 for shallow drawing. A thin vertical wall part 8 is formed on the clearance part of both dies 6, 7 with the drawing of the rising part 5 of the vertical wall part 2. The thin vertical wall part 8 is buckled by bending the vertical wall part 9 as well as pushing down a panel face part 9 in the third stage. The product of excellent quality can thus be produced efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of forming a tear in a container 4. In particular, the present invention relates to a method of forming a tear portion of a container lid, which is opened by tearing an opening piece portion with a tab along a tear guide line formed on a metal material plate.

Conventional technology Container lids that open using tabs have traditionally been used for soft drink cans, etc., but recently they have also been widely used for canned foods and other food cans that are heated in a full oven. . This type of can lid, which uses 5 tabs and has 158 openings, is said to be characterized by its simplicity and safety compared to the conventional means of opening using a can opener. It has been pointed out that sharp parts from tearing the tearing guide remain in the opening, posing a risk of injuring fingers and hands during and after the opening.

This is because the tearing guide line applied to the container lid is simply stamped on the board surface with a die-shaped cutting edge, so a tear portion remains as it is at the opening edge in the direction of the board surface after opening.

Regarding these problems, various technical solutions have been attempted as to how to safely configure the opening edge. Regarding Japanese Patent Publication No. 47-44077 (Title of Invention: Metal Lid and Method for Manufacturing the Same) and Japanese Patent Application No. 59-6099
Inventions such as No. 3 (name of invention: safe container lid with opening edge) have been developed.

In addition, as a means of safely constructing the opening piece that is separated after opening,
An invention related to the patent application (name of invention = 1311+:+one-edge safe container A) filed in Y1 has been developed.

Problems to be Solved by the Invention This invention was developed as a method for forming the tearing part of the latter [safe container lid with one edge of the opening], but depending on how it is used, the can body may be damaged after opening. It can also be applied to the formation of a safe tearing part of a container lid at the opening edge portion remaining on the side.

In addition, in the tearing part of a conventional container lid, where the tearing chamber line is simply stamped on the board surface with the cutting edge of a mold, the pop value, which is the force required to tear when the tab is pulled out, and the The tear value, which is the force required for the tearing to progress, is large, and it is not uncommon for the opening piece to tear suddenly when the tab is pulled forcefully, which further increases the risk. was.

To solve this problem, unlike the method of forming a tear guide line by stamping, the material plate is shallowly drawn, and the wall formed by the shallow drawing is buckled to form a tear guide line. Patent No. 1062741, which is a method, title of the invention:
A method for forming a tear-off type opening piece in a can exists as a prior art. According to this method of forming a tearing guide line, an extremely good tearing guide line can be formed even in cases where it is difficult to stably form a weakened tearing guide line, such as in the case of a tin material plate. It has the advantage that it can be stably formed.

This invention makes use of the special tearing guide wire forming method described in 1γj in the process to stably form a better tearing guide wire and to prevent the tearing part of the mo after tearing. It was created with the purpose of creating a safer tearing part by preventing direct contact with the person making the opening. , H7:l, 9. Means for Solving the Problems The method for forming a split portion in a container lid of the present invention consists of the following three steps:
The basic concept of each step is shown in FIGS. 1 to 4.

As shown in FIGS. 1 and 2, the first step is to form a vertical wall portion 2 on a photoresist material plate 1 by drawing. This drawing process is similar to what is commonly done, and as shown in FIG. A W wall portion 2 is formed in the clearance portion between the molds 3 and 4.

The second Xi step is the standing wall formed in the first step, $2
Notachi-F8i! There is one that performs shallow drawing processing on 5. This shallow drawing process is performed by slightly intersecting the lower die die 6 and the upper die die 7 for shallow drawing.
A thin vertical wall portion 8 is formed in the clearance portion.

The third lower step is to push down the board surface portion 9 that has been extruded by the drawing process in the first step. The second process is carried out by supporting the lower surface of the platen part 10 on the rising part 5 side of the standing wall part 2 with the lower die 11 and pressing down the extruded platen part 9 with the upper die 12. . and,
When the board surface part 9 is pushed down in this way, the vertical wall part 2 is
It is bent from the 11F portion into an inverted ■-shape or an inverted U-shape, forming a raised wall 2a protruding from the board surface portion 9.

Further, the thin vertical wall portion 8 formed in the second step simultaneously undergoes a buckling phenomenon and bends due to the depression of the board surface portion 9.

Since the thin vertical wall portion 8 formed in the second process further buckles in the third process, this part forms the crack [3) 1 guide line 8a that is weakened against shearing force. Become.

In the third step, the standing wall portion 2 is bent from the middle portion into an inverted V-shaped or continuous TJ-shape, so that the tearing guide line 8a remains in close contact with the raised wall 2a even after tearing. Therefore, damage caused by the tearing part can be prevented for 1 hour.

1'' p. 3 to 8 show the state in which the torn part formed by the method of the present invention is being torn apart. In each figure, the arrow indicates the opening piece 2 when attached to the container as a container lid.
As can be seen cheerfully in FIGS. 5 and 6, which show the direction of pushing or peeling of 0.21, the opening edge 20a, which is the part where the opening piece 20 is torn, is positioned in close contact with the bulge v21. Damage caused by one edge 20a of the opening can be prevented, and conversely, as shown in Figures 7 and 8, the torn part 22 remaining on the container side is in close contact with the raised wall 23, and when the device is installed. This means that the opening on the container side can be configured safely.

Further, as shown in FIG. 4, the tearing guide line 8a is connected to the raised wall 2a.
The raised wall 2a is formed at the rising part 5 of the wall 2a, and the raised wall 2a is subjected to drawing processing in the first step and is subjected to bending load in the third step, so that the entire structure is work hardened. Due to the increased rigidity, the structure is such that stress concentration is likely to occur on the tearing guide wire during tearing.

Therefore, the pop value and tear value for tearing the container lid formed by the method of the present invention are determined by the tearing guide line 8a.
Coupled with the way it is formed, it is possible to keep the value to a very low value.

Embodiment Next, an embodiment of the present invention will be described with reference to FIGS. 9 to 17.

FIGS. 9 to 12 sequentially show the steps of forming a tear portion on a container lid using a die.

In FIG. 1, 30 is a lid material plate, and in this process, first, a lower die mold 31 and an upper die mold 32 are used.
A part 30 is attached to the can body around the lid material plate 30.
A is formed, and at the same time, the plate portion 30b, which becomes the center portion of the container lid, is pressed down and formed by drawing.

Next, as shown in FIG. 10, by drawing using the lower die 33 and the upper die 34, the center plate surface portion 35 of the dish portion 30b is pushed up, and a standing wall portion 36 is formed around it. .

Next, the product formed in the previous step is subjected to a shallow drawing process on the rising portion 36a of the vertical wall portion 36 using the lower die die 37 and the upper die die 38, as shown in the 11th Y. This shallow drawing process is performed by slightly intersecting the lower die 37 and the lower die 38, as shown in No. 13 [4], so that the thickness of the rising portion 36a of the vertical wall portion 36 is shallowly drawn in the clearance area. This is to form a thin vertical wall portion 39.

Next, the molded product in the previous step is placed in the lower die 40 as shown in FIG.
The center y-plane portion 35 that has been extruded in the process shown in the figure is pushed away by the north die 41. That is, the lower die mold 40 has a thin vertical wall portion 3 that has been modified in the previous process.
The upper die mold 41 supports the outer part of the board 9 from below, and presses down the part of the center board surface part 35 that exists inside the vertical wall part 36. As a result of this step, as shown in FIG. 14, the standing wall portion 36 formed in the step of FIG. The thin vertical wall portion 39 undergoes the buckling phenomenon and becomes immersed, leading to splitting! It becomes 143.

Generally, such a bent raised part is formed by inserting a medium die into the bead part, but in this case, it can be formed automatically by pressing down the center board surface part 35 without using a medium die. A ridged wall 42 which is bent at the same time as a tearing guide line 43 is formed.

In this step, as shown in FIG. 15, the pressing part 44a of the upper die 44 is made into a truncated conical shape, and the central board surface part 45 is pressed down to bend the standing wall part while tilting it toward the rising part. If this is done, the raised wall 46 after molding will be formed to be inclined toward the tearing guide line 47, as shown in FIG. When the raised wall 46 is formed to be inclined in this manner, when the opening piece portion 48 is torn along the tearing guide line 47, the torn part is positioned below the raised wall 47. The periphery of the opening piece 4B becomes safer.

The entire container lid formed by the above process is the 17th
It will look like the one shown in the figure.

A tab 49 is attached to the container lid so that its tip 49a extends beyond the raised wall 42 and is positioned at the tearing guide line 43, and the tab 49 serves as an opening means as in a general lid of this type. This is done by pulling up the tearing guide line 43 to tear a local part of the tearing guide line 43, and then pulling up the tab 49 to tear it along the tearing guide line 49, and finally removing the opening piece 50. It will be done.

Effect of the invention This invention has the following advantages.

Since the tearing guide line of the container lid is formed by buckling the thin vertical wall, a weakened tearing guide line can be stably formed.

In addition, in addition to the tear guide line forming means, by forming the tear guide line on the rising portion of the raised wall, it is possible to construct a structure in which the stress at the time of tearing is easily concentrated on the tear guide line. It is possible to suppress the pop value and tear value, which are the forces required to tear the opening piece of the lid, to dramatically low values.

Therefore, even when the container lid is constructed from a tin material plate, the same tearing conditions as when using an aluminum acid material plate can be achieved.

Another important effect is that after opening the container lid formed by this invention, the torn part attaches to the raised wall, which provides excellent safety and prevents injury to the hands and fingers of the person opening the container. It becomes something.

From the perspective of the die to be used, the life of the die is extremely long because the blade required for stamping is not used to form the tearing guide line, and the life of the die is extremely long. Is it possible to form a tearing guide line by buckling a thin vertical wall without using a medium-sized tool? Another great advantage is that it can be done in one step.

[Brief explanation of the drawing]

Figures 1 to 4 show the method of this invention divided into steps,
5 to 8 are sectional views showing the state in which the cleavage portion formed by the method of the present invention is torn, and 9 to 12 are sectional views showing the basic concept. This is an embodiment of the invention, and is a cross-sectional view sequentially showing the steps of forming a tear portion on a container lid using a die mold. FIGS. 13 and 14 are main parts in FIGS. 11 and 12, respectively. The enlarged view, FIG. 15, is another actual/flow side of the present invention, and FIG. FIG. 17, which is an enlarged view of the main part in the figure, is a perspective view (including a partially broken surface) of the container lid molded according to the example. In each figure, 1 is the lid material plate, and 2 is the vertical wall part. 2a is a raised wall, 3 is a lower die mold, 4 is an upper die mold, 5 is a rising part, 6 is a lower die mold, 7 is an upper die mold, 8 is a thin vertical wall part, 8 & is a tearing guide line , 9 is the board part,
10 is the board surface part on the rising side, 11 is the lower die mold, 12
is an upper die mold, 20 and 21 are opening pieces, 20a is one edge of the opening, 22 is a split part, 23 is a raised wall, 30 is a lid material plate,
30a is a seaming part, 30b is a dish part, 31 is a lower die type, 32 is an upper die type, 33 is a lower die type, 34 is a side die type, 35 is a center board surface part, 36 is a standing wall part, 3
6a is a rising part, 37 is a lower die mold, 38 is an upper die mold, 39 is a thin wall part, 40 is a lower die mold, 41
is the upper die mold, 42 is the raised wall, 43 is the tearing guide line, 4
4 is an upper die mold, 44a is a pressing part, 45 is a center board surface part, 4, 6 are raised walls, 47 is a tearing guide line, 48 is an opening piece part, 49 is a tab, 49a is a tip of the tab, 50 is a The opening piece is shown. Toshikazu Nagai Figure 6 Figure 7 Figure 15 Figure 17

Claims (2)

[Claims] (1) Form a vertical wall part by drawing on the lid material plate, apply shallow drawing to the rising part of the vertical wall part to form a thin vertical wall part, and press the board surface part extruded by the drawing process. A method for forming a split portion in a container lid, characterized by bending the vertical wall portion by lowering the lid and buckling the thin vertical wall portion at the same time. (2) Tearing in a container lid as set forth in claim (1), in which the vertical wall portion is bent while tilting toward the rising portion in the step of pushing down the board surface portion extruded by the drawing process. How to form the part.