JP2556502B2 - Easy-open can lid with excellent openability - Google Patents

Description

TECHNICAL FIELD The present invention relates to a partial opening lid (hereinafter, simply referred to as an easy-open can lid) that can very easily perform an initial opening of an opening piece.

[Conventional technology]

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

In order to improve the openability of this easy open can lid,
Various proposals for can lids have been made so far. For example, JP-A-58-149251 proposes an easy-open can lid provided with a main score engraved on the can lid and an auxiliary score close to the main score.

Further, Japanese Patent Publication No. 40679/1974 discloses that a pulling tab extends outwardly from the main score portion of a region that is first broken by pulling up the pulling tab, substantially parallel to the longitudinal axis of the pulling tab. An easy-open can lid with an auxiliary score has been proposed. This auxiliary score does not break even if the main score is first broken by pulling up the pull knob, but in this way the auxiliary score is extended almost parallel to the longitudinal axis of the pull knob and outward. The opening can be facilitated and a certain improvement in can openability can be seen.

[Problems to be solved by the invention]

However, the ease and difficulty of opening that a person feels when opening the can lid of the easy-open can lid largely depends on the magnitude of the force at the start of opening. Further, when opening with a large force, the pull tab may be torn rapidly, and as a result, the entire easy open can may be impacted and vibrated, and the contents may spill out.

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

Therefore, in order to easily open the easy-open can lid, the inventors of the present invention have provided a horizontal auxiliary score to the lid main body on the non-opening side that is adjacent to the peripheral portion of the fixed portion to which the pulling tab is attached via the score in order to easily open the lid. Was developed, and this was filed in Japanese Patent Application No. 61-40595.

The present invention has been completed as a result of various studies to further improve the can openability, particularly the ease of opening at the early stage of can opening, and is applied to a non-opening one-side can lid in the vicinity of a fixed part to which a pulling tab is fixed. An object of the present invention is to provide an easy-open can lid capable of performing initial opening of an opening piece with a small force by performing mechanical processing for locally weakening the rigidity in the tearing direction of the opening piece.

[Means for solving problems]

The easy-open can lid of the present invention is an easy-open can lid having an opening piece surrounded by a score and having a tension knob fixed thereto, and having a machined portion in which the rigidity in the tearing direction of the opening piece is locally weakened. , The machined part is continuous within a range of ± 15 degrees with respect to the direction orthogonal to the tearing direction of the opening piece, with the starting point being the region from the straight line passing through the center point of the fixing part and orthogonal to the tearing direction to the vertex of the opening piece. Alternatively, it is characterized in that it is provided in the non-open one-sided can lid in the vicinity of the fixing portion so as to extend in the left and right in a discontinuous manner.

Here, the machined portion has a region from a straight line passing through the center point of the fixed portion and orthogonal to the tearing direction to the apex of the opening piece as the starting point, and within a range of ± 15 degrees with respect to the direction orthogonal to the tearing direction of the opening piece. It can be provided on the non-opening one-sided can lid so as to extend to the left or right in a continuous or discontinuous manner. The cross-sectional shape of the machined portion can be formed by thinning the non-opening side portion into a V shape, a U shape, a thin shape, or the like. Further, the distance between the apex of the opening piece and the outer periphery of the fixed portion of the pulling tab is preferably 0.4 mm or less.

〔Example〕

Hereinafter, the features of the present invention will be specifically described by way of examples with reference to the drawings.

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

A score 2 is engraved on the 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 the opening piece 3,
After the hole of the pulling tab 4 is fitted into the protrusion, the protrusion is caulked to form the fixing portion 5 to which the pulling tab 4 is attached. An auxiliary score 7 may be provided on the non-opening side portion 6 of the easy-open can lid 1 along the score 2.

In this embodiment, a machined portion 8 for locally weakening the rigidity of the opening piece 3 in the tearing direction 9 is provided at a portion of the non-opening side portion 6 close to the fixing portion 5.

FIG. 2 shows several examples of the cross-sectional shape of the machined part 8. In the figure, (a) is V-shaped, (b) is U-shaped,
In (c), the groove is locally thin-walled, which reduces the rigidity. The cross-sectional shape of the machined portion 8 in the present invention is not restricted to that shown in FIG. 2, and various other shapes can be adopted. For example, any cross-sectional shape may be used as long as it can be locally thinned by combining these, such as a groove-shaped shape to which a V-shape is added.
The remaining thickness t of the thin portion of the machined portion 8 is preferably equal to or greater than the remaining thickness of the score 2.

The position where the machining portion 8 is provided on the non-opening side portion 6 and the installation direction of the machining portion 8 are as follows.
Is important in reducing the rigidity in the tearing direction 9.

First, as shown in FIG. 3, the position where the machined portion 8 is provided is within the range surrounded by the inclined lines 10 and 11. This inclined line 10 is a straight line extending from the intersection point 13 of the score 2 and the straight line 12 passing through the center of the fixing portion 5 and orthogonal to the tearing direction 9 to the straight line 12 in the tearing direction 9 to the left and right. Is. The other inclined line 11 is a straight line extending from the apex 3a of the opening piece 3 to the left and right, inclining in the direction opposite to the tearing direction 9 with respect to the straight line 14 passing through the apex 3a of the opening piece 3 and orthogonal to the tearing direction 9. is there. The angle θ formed by these inclined lines 10 and 11 with the respective straight lines 12 and 14 is 15 degrees.
That is, the machined portion 8 in the present invention is provided in the area shown by the diagonal lines surrounded by the inclined lines 10 and 11 and the score 2 in FIG.

Regarding the starting point 8a of the machined portion 8, as shown in FIG. 4, the distance l from the apex 3a of the opening piece 3 to the center of the fixed portion 5
To the apex 3a of the opening piece 3 from the starting point 8a of the machined part 8
The distance d to is maintained in the relationship of 0 ≦ d ≦ l. Preferably, 0 <d ≦ 2 / 3l. Here, the starting point of the machining section 8
8a may or may not be linked to score 2. When not connected to the score 2, it is preferable to maintain the distance a between the starting point 8a of the machined portion 8 and the score 2 at 1.5 mm or less.

Next, with respect to the engraving direction of the machined portion 8, it is engraved along the direction orthogonal to the tearing direction 9 or the angle ψ formed by the engraved direction of the machined portion 8 with respect to this orthogonal direction is set. , −15 degrees ≦ φ ≦ + 15 degrees can be maintained. This inclination angle ψ is more preferably −12.5 to +
The range is 12.5 degrees.

FIG. 5 shows the influence of the inclination angle ψ on the initial can opening force. As is clear from this figure, the inclination angle ψ is about 20.
When the inclination angle is ψ ≦ + 15 degrees, the effect of decreasing the initial can-opening force appears, and the effect becomes remarkable when the inclination angle is ψ ≦ + 15 degrees. Furthermore, the inclination angle ψ
Is less than ± 12.5 degrees, the can opening force is the smallest. In this example, the inclination angle ψ when the easy-open can lid 1 is made of T-4 tinplate material having a plate thickness of 0.25 mm and the remaining thickness of the score 2 and the remaining thickness of the machined portion 8 are set to 65 μm. It shows the effect of.

As described above, the machined portion 8 is engraved in the vicinity of the fixed portion 5 of the non-opening side portion 6 by defining the starting point 8a and the engraving direction, so that the tearing direction 9 is formed in the vicinity of the fixed portion 5 of the non-opening side portion 6. The bending rigidity of is locally weakened, and as a result, the can opening force is concentrated at the opening start point, and the initial can opening force is significantly reduced. That is, the initial can opening force at the time of initial can opening is reduced, and the can opening property becomes extremely good.

FIG. 6 shows several examples of the shape of the machined part 8 when viewed in a plane. That is, the machined portion 8 has a single thin-walled portion having a V-shaped or U-shaped cross section linearly provided in a direction orthogonal to the tearing direction as shown in FIG. A plurality of similar linear thin-walled portions as shown in FIG. 2, a thin-walled thin-walled portion having a thin cross-sectional shape (see FIG. 2 (c)) as shown in FIG. As shown in (d), the starting point 8a of the machined part 8 is provided linearly apart from the score 2, and the starting point 8a of the machined part 8 is discontinuous from the score 2 as shown in FIG. Provided, the machined portion 8 as shown in FIG. 7F has a thin cross-sectional shape and a wide thin portion, and the machined portion 8 has a curved shape as shown in FIG. Things are adopted.

Next, Table 1 shows the results obtained by making various easy open can lids from T-4 tinplate material having a plate thickness of 0.23 mm and measuring the initial can opening force thereof. In the table, a conventional easy-open can lid without a machined part and an easy-open can lid with an auxiliary score 7 on the non-opening side along the tearing direction 9 as shown in FIG. 9 ( Japanese Patent Publication Sho 49-40679
Gazette) and Comparative Examples 1 and 2, respectively. On the other hand, Examples 1 to 7 are easy-open can lids having the shape shown in FIG.

As is clear from Table 1, as compared with Comparative Examples 1 and 2,
Example 1 in which the bending rigidity in the tearing direction of the opening piece of the non-opening one-side can lid in the vicinity of the fixing portion 5 was locally weakened by the machined portion 8
In the case of ~ 7, the initial can opening force is reduced. Therefore, the can opening work could be started without applying a large force to the easy open can lid.

Furthermore, by maintaining the distance D between the apex 3a of the opening piece 3 and the outer periphery of the fixed portion 5 with respect to the XX axis parallel to the tearing direction 9 at a predetermined value or less, the initial can opening force can be further reduced. it can. FIG. 7 is an enlarged view showing the periphery of the fixing portion 5. That is, when the distance from the apex 3a of the opening piece 3 defined by the score 2 to the periphery of the fixed portion 5 is D, this distance D is 0.4 mm or less, more preferably 0.3 mm or less.

When the distance D is reduced, the initial can-opening force drops sharply at 0.4 mm. It is considered that this decreasing tendency is due to the influence of the highly rigid fixing portion 5 being transmitted to the score 2 at the apex 3a portion and the concentration of stress becoming more localized. Then, the initial can-opening force shows a substantially constant decreasing tendency when the distance D becomes 0.3 mm or less. The lower limit of the distance D is preferably set to 0.1 mm in consideration of the ease of processing using a mold.

FIG. 8 shows the influence of the distance D on the initial can opening force. As is clear from this figure, the initial opening force is
It begins to decrease sharply at a distance of a = 0.4 mm, and tends to decrease substantially at 0.3 mm or less. It should be noted that the curve (a) in FIG. 8 shows the relationship between the initial canning force and the distance D in the present embodiment, that is, the case where the machining section 8 is present, and the curve (b) shows the case where the machining section 8 is not present. This is shown as a comparative example.

In any of the examples, the sharp decrease in the initial can opening force is seen at the distance a = 0.4 mm as described above, because the influence of the highly rigid fixing portion 5 is transmitted to the score 2 as described above, It is believed that concentration will be more localized. In addition to this, in the case of the present embodiment, the non-opening side portion 6 is more easily deformed by the machined portion 8, so that the tearing of the opening piece 3 is likely to occur along the score 2. . This is represented as a decrease in the curve (a) with respect to the curve (b) in FIG.

As described above, according to the present invention, it was demonstrated that the initial can opening force is significantly reduced and the can opening operation can be started very easily.

The material used for the easy open can lid of the present invention is not particularly limited, and various materials listed below can be used.

(1) Metal materials typified by iron and iron alloys or aluminum and aluminum alloys (2) Metal materials coated with an organic material such as coating or coating on the metal material of (1) (3) The above (1) or Composite metal material obtained by joining an organic material such as a resin to the metal material of (2) in a layered manner (4) A composite metal material in which different kinds of metal materials of the above (1) and / or (2) are layered together Effect] As described above, in the easy open can lid of the present invention, the rigidity in the tearing direction of the opening piece of the non-opening side portion in the vicinity of the fixed portion of the pulling tab is locally weakened, and the initial opening can. Power is greatly reduced. As a result, it is possible to smoothly open the can without requiring an excessive force, and to prevent unexpected vibration or impact on the can body.

[Brief description of drawings]

FIG. 1 shows an outline of an easy-open can lid in one embodiment of the present invention, FIG. 2 shows an example of a sectional shape of a machined portion, and FIG. 3 shows the machined portion provided on a non-open one-sided can lid. FIG. 4 is a view for explaining the region, and FIG. 4 is a view for explaining the position of the starting point of the machining portion provided on the non-opening one-sided can lid, and FIG. 5 is the influence of the engraving direction of the machining portion on the initial can opening force. FIG. 6 shows several examples of the planar shape of the machined portion provided in the non-opening side portion, and FIG. 7 is a diagram for explaining the distance D between the apex of the opening piece and the outer periphery of the fixed portion. , Fig. 8 shows the effect of the distance D on the initial can opening force, and Fig. 9 shows the Japanese Patent Publication No. 49-4067.
The shape of the easy-open can lid disclosed in Japanese Patent No. 9 is shown.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-57-199535 (JP, A) Actually opened 62-152919 (JP, U) Actually opened 59-133439 (JP, U) JP-B 49- 40679 (JP, B1) JP-B 57-42544 (JP, B2) JP-B 55-39794 (JP, Y2)

Claims (3)

(57) [Claims] 1. An easy-open can lid having an opening piece surrounded by a score and having a tension knob fixed thereto, and having a machined portion in which the rigidity in the tearing direction of the opening piece is locally weakened, the mechanical processing being carried out. The part is continuous or discontinuous within ± 15 degrees with respect to the direction orthogonal to the tearing direction of the opening piece, starting from the area from the straight line passing through the center point of the fixed part and orthogonal to the tearing direction to the vertex of the opening piece. An easy-open can lid with excellent openability, which is provided on the non-opening one-side can lid near the fixed part so as to extend to the left and right. 2. The cross-sectional shape of the machined portion according to claim 1 is a thin portion provided by processing the non-opening side portion into a V shape, a U shape, a groove shape, or the like. Easy-open can lid with excellent can open characteristics. 3. An easy-open can with excellent openability, characterized in that the distance between the apex of the opening piece and the outer periphery of the fixed portion of the pulling pick piece according to claim 1 is 0.4 mm or less. lid.