JPH0360737B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a partially opening lid (hereinafter simply referred to as "easy") which can start opening with an extremely small force and can tear the opening piece smoothly. (referred to as open can lids).

[Conventional technology]

The easy-open can lid allows the can lid to be opened using the pulling force of the fingertips without the need for tools such as a cutter. Utilizing this advantage, it is now used in a wide range of applications such as food cans, carbonated beverage cans, and beer cans.

In order to improve the openability of this easy-open can lid, various proposals regarding can lids have been made. For example, an easy-open can that has a main score engraved on the can lid and an auxiliary score close to the lid score has been proposed in Japanese Patent Application Laid-Open No. 149251/1983.

As described above, by providing an auxiliary score, a certain improvement in can opening performance can be seen.

[Problem that the invention seeks to solve]

The force required to open this easy-open can lid is mainly divided into an initial opening force at the start of opening, a force for tearing the opening piece, and a force for separating the opening piece from the can lid. When these forces are averaged, it becomes possible to stably open the can with a constant force. Particularly, if the force required to tear the aperture piece is large among these forces, the aperture piece may be separated while the force is applied. As a result, unexpected movements such as shocks and vibrations are transmitted to the entire easy-open can, and the contents may spill out.

Therefore, the present inventors reduced the initial can opening force by providing a horizontal auxiliary score in the initial rupture area from the apex of the opening piece to a line passing through the center of the fixed part of the tension knob and perpendicular to the tearing direction. Developed an easy-to-open can lid, which was put into practice in 1982.
It was previously filed as No. 40595.

The present invention utilizes the characteristics of this horizontal auxiliary score and uniformly reduces the tearing force along the length of the opening piece, thereby making it possible to smoothly tear the opening piece from the lid body on the non-opening side. The purpose is to provide open can lids.

[Means for solving problems]

In order to achieve the purpose, the easy-open can lid of the present invention is provided with a score so as to surround the opening piece provided with the tension knob through the fixing portion, and the tension knob is fixed from the apex of the opening piece. A horizontal auxiliary score is engraved symmetrically and along a direction within 90 ± 12.5 degrees to the axis parallel to the tearing direction of the opening piece on the non-opening side of the lid body passing through the center of the opening piece and ending on a line perpendicular to the tearing direction. In addition, the opening piece is characterized by having a plurality of scores or thin-walled parts at intervals of 2 to 5 mm that intersect with the tearing direction of the opening piece at an angle of 45 degrees or less to reduce the bending rigidity of the opening piece. do.

The machined part here may be a straight, curved, V-shaped or inverted V-shaped score, or a thin walled part.

[Effect]

The present invention provides a horizontal auxiliary score on the non-opening side of the lid body from the apex of the opening piece to a line passing through the center of the fixed part of the tension knob and perpendicular to the tearing direction, with respect to an axis parallel to the tearing direction of the opening piece. Since it is provided along a direction within 90 ± 12.5 degrees, the bending rigidity of the lid body on the non-opening side in the tearing direction is weakened, and it is easily bent and deformed at the beginning of opening, which causes the pulling piece, and the apex of the opening piece. The bending stress of the surrounding non-opening portion increases, and the force required for initial opening is significantly reduced.

Furthermore, in the opening piece, 45 mm in the tear direction of the opening piece.
Score or thin section at an angle within 2 to 5 mm
Since the bending rigidity is reduced by providing the opening pieces at intervals of Tear force is reduced.

〔Example〕

Hereinafter, the features of the present invention will be specifically explained with reference to embodiments shown in the drawings.

FIG. 1 shows the easy-open can lid of this embodiment.

A score 2 is engraved on this easy-open can lid 1, and a portion surrounded by the score 2 becomes an opening piece 3. A protrusion is press-molded on a part of this opening piece 3, and after fitting the hole of the tension knob piece 4 into the protrusion, the protrusion is caulked to form a fixed part 5 to which the tension knob piece 4 is attached. are doing. When the tension knob 4 provided in this way is pulled and pulled, the apex 3a of the opening piece 3 on the fixed part 5 side becomes the opening starting point, and the opening piece 3 is sequentially torn from the lid body along the score 2. .

At this time, in this embodiment, a plurality of scores 7 extending perpendicularly to the tearing direction 6 of the opening piece 3 are provided on the opening piece 3, and from the apex 3a of the opening piece 3 to the center 5c of the fixed part 5. Range d (see Figure 4)
A horizontal auxiliary score 8 symmetrical with respect to the XX axis parallel to the tearing direction is carved on the lid main body 9 on the non-opening side.

FIG. 2 shows several examples with a score of 7 in cross-sectional view. That is, in the example shown in FIG.
In the example shown in FIG.
has been established.

Moreover, FIG. 3 shows several examples of this score 7 in a plan view. That is, the score 7 can be linear, V-shaped, inverted V-shaped, or arcuate, as shown in figures a to d, respectively. With this score of 7, the bending rigidity of the opening piece 3 in the tearing direction 6 is reduced. Therefore, when the opening piece 3 is torn along the tearing direction 6, the opening piece 3 is easily bent along the XX axis direction. Thereby, the tearing force is concentrated on the score 2, and it becomes easy to tear the opening piece 3 along the score 2. In order to obtain the effect of the score or the thin wall portion 7, it is necessary to provide the score or the thin wall portion 7 up to at least the front half of the opening piece 3.

A plurality of scores or thin parts 7 provided on the opening piece 3
The mutual pitch l (see FIG. 4) is preferably 2 to 5 mm. That is, this mutual pitch l
When maintained within this range, the part of the opening piece 3 whose bending rigidity is reduced due to one score or thin wall portion 7 becomes continuous with that due to the other score or thin wall portion 7, and the effect of reducing the tearing force is ensured. Become. When this mutual pitch exceeds 5 mm, the tearing force will vary greatly along the tearing direction 6, making it impossible to tear with a stable force. Further, when the mutual pitch l is less than 2 mm, the stiffness of the opening piece 3 becomes unnecessarily weak, and in some cases, the opening piece 3 may be partially torn off.

Further, when a V-shaped or inverted V-shaped score or thin wall portion 7 is provided, the angle θ (see FIG. 4) between the V-shaped side and the normal line of the X-X axis is 45 degrees or less. When this angle θ exceeds 45 degrees, the influence of the score or the thin wall portion 7 on the reduction in rigidity that facilitates bending of the opening piece 3 around the XX axis becomes small.

On the other hand, the horizontal auxiliary score 8 is as shown in Figure 3 a, c,
They are provided in the lid main body 9 on the non-opening side in a symmetrical positional relationship with respect to the X-X axis, either as a pair as shown in FIG. d, or as a plurality of pairs as shown in FIGS. Due to this symmetrical arrangement, the bending rigidity in the tearing direction of the lid main body 9 on the non-opening side around the fixed portion 5 is reduced uniformly, and the opening piece 3 can be torn from the lid main body 9 without bias. This horizontal supplementary score of 8 is X-X
The angle with the axis shall be maintained within the range of 90 ± 12.5 degrees.
If this angle range is satisfied, the apex 3a of the opening piece 3
The horizontal auxiliary score 8 may be provided anywhere within the range of the distance d from the center of the fixed portion 5c, but it is preferable to provide the horizontal auxiliary score 8 closer to the apex than in the middle of the distance d. By maintaining the horizontal auxiliary score 8 within these ranges, the bending rigidity of the lid body on the non-opening side in the tearing direction is weakened, and when the tension knob is pulled up to start opening the opening piece, the bending becomes easy and the apex of the opening piece is easily bent. The stress distribution on the surrounding non-opening side increases as shown by the solid line 10 in FIG. In addition, in this figure, the broken line 11 is the stress distribution around the apex of the aperture piece when the aperture piece without the horizontal auxiliary score is started to be opened.

In this way, the horizontal auxiliary score locally lowers the bending rigidity in the tearing direction on the non-opening side, bends easily and sharply at the beginning of opening, and increases the bending stress overall. The effect of the thin-walled portion is assisted, and the initial opening force (POP value) is significantly reduced as shown in Figure 9. However, when the horizontal auxiliary score is 8, the tear direction is 6.
If the angle formed with the axis X--X parallel to is more than 90±12.5 degrees, the bending rigidity in the tearing direction will decrease so little that the above-mentioned effects cannot be obtained.

The test material shown in Figure 9 was an easy-open can lid made from tin plate with a thickness of 0.23 mm, and the opening piece was scored with a residual thickness of 60 μm. In addition, although no supplementary score is provided, initial can opening power (POP value)
The weight was 1.70Kgf.

In this way, the horizontal auxiliary score 8 reduces the rigidity of the lid main body 9 around the fixed portion 5, and the score or thin wall portion 7 reduces the bending rigidity of the opening piece 3. As a result, the tearing force uniformly decreases in the tearing process of pulling the opening piece 3 along the score 2 from the start of opening. FIG. 5 shows the variation in the can opening force with the longitudinal direction of the opening piece 3 as the horizontal axis. The test material in Fig. 5 is an easy-open can lid made from tin plate with a thickness of 0.23 mm, and the score of the opening piece is determined to be 67 μm in remaining thickness.
It is.

The solid line in the figure shows the case where the easy-open can lid of the present invention with the horizontal auxiliary score 8 and score 7 engraved is opened. On the other hand, the case where the conventional easy-open can lid is opened without providing either the score 7 or the horizontal auxiliary score 8 is shown by a broken line.

As is clear from this figure, in the case of the broken line, the can-opening force and the fluctuations in the can-opening force are large, which gives unexpected shocks, vibrations, etc. to the can body when opening the can, and prevents smooth can opening. On the other hand, in the case of the solid line of this embodiment, the can opening force from the start of opening to the separation of the opening piece 3 is small and has little variation. Therefore, it has become possible to open the can with a small force without applying shock, vibration, etc. to the can body.

In this way, the can-opening force is reduced and the fluctuations in the can-opening force are reduced. In addition, the distance a (fourth
6), the force required to start opening the can can be further reduced.

That is, as shown in FIGS. 4 and 6, by setting the distance a between the outer periphery of the fixed portion 5 and the apex 3a of the opening piece 3 to 0.4 mm or less, preferably 0.3 mm or less, as shown in FIG. As shown in , the initial can opening force decreases rapidly. This is considered to be due to the fact that when the interval a is made small, the influence of the highly rigid fixed portion 5 is transmitted to the apex 3a, and the stress concentration at the apex 3a becomes more localized. Therefore, it is possible to start opening the can with a smaller force, and this, combined with the effect of the horizontal auxiliary score 8 and the score or thin wall part 7 described above, makes it possible to smoothly carry out the process from opening the can to tearing it. Become.

There is no need to specify the material to which the easy-open can lid of the present invention is applied, and the following materials can be used, including commonly used tin plate and aluminum plate.

(1) Non-ferrous metal materials such as iron and iron alloys, or aluminum and aluminum alloys (2) Metal materials that have undergone surface treatment such as plating or painting on the metal materials in (1) above (3) (1) and (4) A composite metal material in which dissimilar metal materials in (1) and/or (2) are bonded in layers to the metal material in (2), or The horizontal auxiliary score in the present invention is not limited to the embodiments shown in the drawings, but can be applied to the commonly used V-shaped cross-sectional shape, U-shaped cross-sectional shape, groove-shaped cross-sectional shape, etc., where the bending rigidity is locally reduced. It can be made into various cross-sectional shapes.

The present invention is also extremely effective when applied to easy-open can lids in which shallow auxiliary scores are carved parallel to the main score.

〔Effect of the invention〕

In the easy-open can lid of the present invention, the rigidity of the lid body on the non-opening side adjacent to the apex of the opening piece is reduced to facilitate deformation at the apex, and the bending rigidity of the opening piece in the tearing direction is scored or Since the strength is reduced by the thin wall portion, the aperture piece can be torn from the lid body with a small force, and the variation in the tear separation force when tearing the aperture piece along the score is reduced. In this way, the easy-open can lid can be opened smoothly without applying shocks, vibrations, etc. to the can body.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an easy-open can lid according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the score and thin wall portion provided on the opening piece of the can lid.
FIG. 3 also shows several examples of the score and horizontal auxiliary scores in plan view. Further, FIG. 4 shows an example in which a means for lowering the initial can opening force is added, and FIG. 5 is a graph showing the variation of the can opening force along the longitudinal direction of the opening piece. FIG. 6 is a diagram explaining the distance a, and FIG. 7 shows the initial can opening force and the distance a.
It is a graph showing the relationship between. Fig. 8 is a diagram for explaining the action of the horizontal auxiliary score of the present invention, and Fig. 9 shows that the angle at which the auxiliary score is provided with respect to the tearing direction axis of the opening piece is the initial can opening force (POP value).
FIG.

Claims (1)

[Scope of Claims] 1. A score is provided so as to surround an opening piece on which a tension knob piece is provided via a fixed part, and the score passes from the apex of the opening piece to the center of the fixed part of the tension knob piece,
90 degrees to the axis parallel to the tearing direction of the opening piece on the non-opening side of the lid body up to the line perpendicular to the tearing direction.
Horizontal auxiliary scores are engraved symmetrically along a direction within ±12.5 degrees, and a score or a thin wall part of 2 to 5 mm that crosses the opening piece at an angle of within 45 degrees to the tearing direction of the opening piece. An easy-open can lid with excellent can-opening characteristics, characterized in that a plurality of opening pieces are provided at intervals of , and the bending rigidity of the opening pieces is reduced. 2. The easy-open can lid with excellent can opening characteristics as claimed in claim 1, characterized in that the distance between the apex of the opening piece and the outer periphery of the fixed portion of the tension knob piece is 0.4 mm or less.