JPH0348035Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention makes it possible to smoothly tear the opening piece from the lid body on the non-opening side in the initial breakage region from the apex of the opening piece to the periphery of the fixed part. This invention relates to a partially opening can lid (hereinafter simply referred to as an easy-open can lid).

[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 can opener. Taking advantage of 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 studies regarding can lids have been conducted. For example, an easy-open can that has a main score engraved on the can lid and an auxiliary score adjacent to the main score has been proposed in Japanese Patent Application Laid-Open No. 149251/1983.

By providing such an auxiliary score, a certain improvement in can opening performance can be seen.

[Problem that the invention attempts to solve]

However, the ease or difficulty a person feels when opening an easy-open can lid is largely influenced by the amount of force applied at the beginning of opening. That is, the greater the force required to start opening, the worse the opening performance is. Also, when opening with great force,
There is a risk that the tension tab may be torn rapidly, resulting in shock and vibration to the entire easy-open can, and the contents may spill out.

However, when using the above-mentioned auxiliary score, there is a limit to the improvement in can opening performance, and a relatively large force is still required to start opening.

Therefore, in order to facilitate the opening of this easy-open can lid, the inventor of the present invention installed a horizontal auxiliary score on the non-opening side of the lid body adjacent to the periphery of the fixed part to which the tension knob is attached via the score. An engraved version was developed and filed as Utility Application No. 40595, 1983.

The present invention takes advantage of the characteristics of this horizontal auxiliary score and creates an easy-open can lid that can tear the opening piece smoothly with a small force in the initial breakage region from the apex of the opening piece to the periphery of the stuck part. The purpose is to provide.

[Means for solving problems]

In order to achieve the purpose of the easy-open can lid of the present invention, a score is provided so as to surround the opening piece provided with the tension knob via the fixed part, and the apex of the opening piece in the tearing direction and the fixed part are provided. The distance between the opening piece and the outer periphery is 0.4 mm or less, and the opening piece is torn 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. A horizontal auxiliary score is carved along a direction within 90±12.5 degrees with respect to an axis parallel to the direction and symmetrically to the tearing direction.

[Effect]

The present invention provides an auxiliary score of 90% to 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 the axis parallel to the tearing direction of the opening piece. It is carved along a direction within ±12.5 degrees.

As a result, the bending rigidity of the lid body on the non-opening side in the direction of tearing the opening piece is locally weakened, and bending deformation becomes easy at the time of opening when the tension knob is triggered, resulting in bending stress around the apex of the opening piece on the non-opening side. increases overall, and the opening force at the start of opening becomes noticeably reduced.

〔Example〕

Hereinafter, 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. It should be noted that an auxiliary score may be provided along the score 2 to act as a stress absorbing portion to prevent cracks from occurring in the score 2 when forming the score 2 or handling the easy-open can.

After a protrusion is press-molded near the apex 3a of the opening piece 3, the hole of the tension knob 4 is fitted into the protrusion and the protrusion is caulked to form a fixing part 5 to which the tension knob 4 is fixed.

In this example, as shown in FIGS. 3 and 6, the distance a between the apex 3a of the opening piece 3 and the outer periphery of the fixed part 5 with respect to the XX axis parallel to the tearing direction A.
is 0.4 mm or less, preferably 0.3 mm or less.

In addition, a horizontal auxiliary score 7 is carved on the lid body 6 on the non-opening side along the direction intersecting the X-X axis within a distance l from the apex 3a of the opening piece 3 to the center 5b of the fixed part 5. ing. This horizontal auxiliary score is 7
may be a single pair or multiple pairs with respect to the X-X axis as shown in FIG. however,
Horizontal auxiliary score 7 extending left and right in Figure 3
It is necessary to provide them symmetrically with respect to the X-X axis. The angle that this horizontal auxiliary score 7 makes with the X-X axis is maintained within the range of 90±12.5 degrees. As long as this angle range is satisfied, the horizontal auxiliary score 7 may be provided at any location within the distance l from the apex 3a of the opening piece 3 to the center 5b of the fixed part.
It is preferable to carve from the apex to the middle of the distance l. By maintaining the angle of the horizontal auxiliary score 7 within these ranges, the bending rigidity of the lid body on the non-opening side in the tearing direction is partially weakened, and when the tension knob is pulled up and the opening piece starts opening, Bending deformation becomes easy, and the non-opening stress distribution around the apex of the opening piece increases as shown by the solid line 8 in FIG. In this figure, the broken line 9 represents the stress distribution around the top of the aperture when the aperture without the auxiliary score is started to be opened.

In this way, the horizontal auxiliary score locally reduces the bending stiffness in the tearing direction on the non-opening side, making bending deformation easier at the beginning of opening, increasing the bending stress overall, and increasing the opening force at the beginning of opening (POP value)
becomes significantly lower as shown in FIG.

However, if the angle that the horizontal auxiliary score 7 makes with the XX axis parallel to the tearing direction A exceeds 90±12.5 degrees, the bending rigidity in the tearing direction decreases so much that this effect cannot be obtained.

The test material in FIG. 8 is a tin plate with a thickness of 0.23 mm, and the remaining thickness of the score is 60 μm.

In addition, the opening force (POP value) without the auxiliary score is 1.7Kgf. Further, the remaining thickness of the lid main body 6 at the portion where the horizontal auxiliary score 7 is formed may be the same as the remaining thickness at the portion where the score 2 is formed, or may be slightly thicker.

When the distance a from the apex 3a of the opening piece 3 to the outer periphery of the fixed portion 5 is made small, the initial can-opening force sharply decreases after 0.4 mm. This decreasing tendency is due to the influence of the highly rigid fixed part 5 on the score 2 of the apex 3a.
This is thought to be due to the fact that the stress is concentrated more locally. The initial can-opening force shows an almost constant decreasing tendency when the distance a becomes 0.3 mm or less. Note that in consideration of ease of processing using a mold, it is preferable that the lower limit of the distance a be 0.1 mm.

To explain this using FIG. 4, when the tension knob 4 stands up, the pulling force F acts on the opening piece 3 with the end of the tension knob 4 on the side of the fixed portion 5 as a branch P. This acting force acts on the score 2 at the apex 3a of the opening piece 3, and that portion is torn. Here, the area around the fixed part 5 is a work-hardened area because the fixed part 5 was formed by caulking the protrusion provided on the opening piece 3, and a part of the tension knob piece 4 is overlapped. Since the opening piece 3 and other parts of the lid body are aligned, the rigidity of the opening piece 3 is considerably higher than that of the other parts of the lid body. Further, a horizontal auxiliary score 7 is provided on the non-opening side from the apex 3a of the opening piece to a line passing through the center of the fixed part and perpendicular to the tearing direction. Therefore, following the rise of the tension knob 4, the portions around the fixed portion 5 that have low bending rigidity are deformed. Therefore,
When a score is provided in a highly rigid part, bending stress is promoted to concentrate in that part, and the opening piece 3 is easily opened from the lid body.

After a crack has appeared in the score 2 at the apex 3a in this way, when the tension knob 4 is further pulled,
The crack moves along the score 2 and reaches the area where the horizontal auxiliary score 7 is provided. Here, the lid body 6 on the non-opening side is
Since the rigidity of the lid body 6 is weakened, the lid body 6 can be easily deformed. On the other hand, since the area around the fixed portion 5 still has high rigidity, the pulling force F is efficiently concentrated on the score 2 without being dispersed elsewhere. As a result, the initial breaking force at the start of opening is reduced.

FIG. 5 shows the effect of this distance a on the initial can opening force. As is clear from this figure, the initial can-opening force begins to decrease rapidly after the distance a=0.4 mm, and shows a nearly constant decreasing tendency below 0.3 mm. Note that the curve a in FIG. 5 shows the relationship between the initial can opening force and the distance a in this example, that is, in the case where there is a horizontal auxiliary score of 7, and the curve b shows the relationship between the initial can opening force and the distance a in the case where there is no horizontal auxiliary score of 7 as a comparative example. It is something that

In either example, there is a sudden drop in the initial can opening force after the distance a = 0.4 mm, because the influence of the highly rigid fixed part 5 is transmitted to the score 2.
It is thought that stress concentration becomes more localized. This horizontal auxiliary score 7 makes it easier to deform the lid body 6 on the non-opening side, resulting in a score of 2.
The opening piece 3 is likely to be torn along this line. This is represented in FIG. 5 as a decrease in curve a relative to curve b.

As a result, the following can be said. That is, in the case of this embodiment, since the can can be initially opened with a small force, the can can be opened without applying shock or vibration to the can body.

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 / or a composite metal material in which an organic material such as a resin is bonded in layers to the metal material in (2); (4) a composite metal material in which dissimilar metal materials in (1) and/or (2) are connected in a layer; The 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., which locally reduces bending rigidity. It can be made into various cross-sectional shapes.

[Effect of idea]

As explained above, in the easy-open can lid of the present invention, by bringing the apex of the opening piece closer to the outer periphery of the fixed part, and by carving horizontal auxiliary scores around the fixed part, the initial rupture area can be reduced. The opening piece can be opened from the lid body on the non-opening side with a small force, and therefore, when starting to open the can, shocks, vibrations, etc., which are seen in conventional easy-open can lids, are not applied to the can body. There is no. As described above, according to the present invention, an easy-open can lid with excellent can opening performance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an easy-open can lid according to an embodiment of the present invention, FIG. 2 is a diagram showing several examples of horizontal auxiliary scores provided on the lid, and FIG. 3 is a diagram showing the vicinity of the apex of the opening piece. It is a diagram showing an enlarged view of the fourth
The figure is a diagram explaining the opening state, FIG. 5 is a graph showing the relationship between initial can opening force and distance a, and FIG.
The figure is a diagram explaining the distance a. Figure 7 is a diagram for explaining the effect of the horizontal auxiliary score of the present invention, and Figure 8 shows the effect of the angle of the auxiliary score with respect to the tear direction axis of the opening piece on the initial opening force (POP value). FIG.

Claims (1)

[Scope of utility model registration request] A score is provided so as to surround the opening piece on which the tension knob is provided via the fixed part, and the distance between the apex of the opening piece in the tearing direction and the outer periphery of the fixed part is 0.4 mm or less, and On the lid body on the non-opening side from the apex to the line passing through the center of the fixed part of the tension knob and perpendicular to the tearing direction,
90±12.5 with respect to the axis parallel to the tearing direction of the opening piece
An easy-open can lid with excellent initial breakage characteristics, characterized by having horizontal auxiliary scores engraved along a direction within 100 degrees and symmetrically with respect to the tearing direction.