JP2004115096A - Bottle can and bottle can with cap - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bottle can to which a cap is attached in such a manner that the cap is not detached even by an abnormal pressure increase after re-plugging and to provide a bottle with a cap. <P>SOLUTION: In the bottle can capable of being re-plugged by attaching the cap, a dome portion 17 recessed toward the inside of a can body 4 is mounted on a can bottom 15 and an easily tearable portion 20 is formed in the vicinity of the center of the dome portion 17 or the easily tearable portion is formed on the circular concave curved surface portion 18 formed in the circumferential margin portion of the dome portion 17 of the can bottom 15. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a bottle can to which a cap is attached and hermetically sealed, in particular, a bottle can having a function of preventing an abnormal increase in internal pressure, and a bottle can with a cap to which the cap is attached. About.
[0002]
[Prior art]
Generally, a metal bottle can widely used as a beverage can is formed by drawing (drawing) a metal plate made of aluminum or an aluminum alloy and then performing ironing (ironing). It is manufactured by forming a base having an external thread on the top of a can called a DI can. After filling the contents into this bottle can, a cap is attached to the mouthpiece of the bottle can to obtain a bottle can with cap. The bottle can with a cap is characterized in that once the cap is opened, the cap can be re-attached to seal the opening of the bottle can and then re-opened. Further, when the bottle can with a cap is filled with, for example, a carbonated beverage, the inside of the bottle can has a positive pressure, and thus has a structure capable of withstanding a certain internal pressure.
[0003]
Also, conventionally, by forming a low-strength dent at the center of the can bottom, when a gas is generated due to deterioration or decay of the contents, the dent protrudes due to an increase in internal pressure due to the gas. There has been used a detection method capable of detecting alteration and decay from the soil. (See, for example, Patent Document 1.) Further, by forming a weak seal portion on the side seal surface of the cap and forming a small gas exhaust hole, the gas is discharged to the outside when the cap is deformed by the internal pressure. Gas exhaust methods were used. (For example, see Patent Document 2.)
[0004]
[Patent Document 1]
JP-A-2-23312 (Sections 1-4, Fig. 1)
[Patent Document 2]
Utility Model Registration No. 2545609 (Section 1-3, FIG. 1)
[0005]
[Problems to be solved by the invention]
By the way, in the bottle with a cap, when the cap is re-opened in a state where the contents remain, gas is generated by secondary fermentation of the contents inside the bottle with a cap depending on the subsequent storage condition, If the internal pressure rises abnormally due to the gas and the internal pressure rises beyond the fitting force between the female screw portion and the male screw portion, there is a problem that the cap gets over the screw thread and comes off, and the cap flies off due to the internal pressure. Even when the above-described method for detecting an increase in internal pressure is used, the same problem occurs if the subsequent storage condition is not improved, and even when the gas discharge method using a cap is used, deformation due to internal pressure is caused. Similar problems have arisen due to the difficulty of adjusting the deformation due to the small amount and the difficulty in setting the width and length of the side seal surface.
[0006]
For example, the withstand pressure value before opening is set to 0.8 to 1.5 MPa, and the withstand pressure value after reopening is set to 0.4 to 0.6 MPa. When the internal pressure exceeds the above withstand pressure value, the cap is closed. Comes off and flies. In order to solve such a problem, it is conceivable to increase the number of turns of the female screw portion and the male screw portion to increase the fitting force between the female screw portion and the male screw portion. It is also not preferable because the opening torque of the increases as well, and the number of turns of 1.7 to 2.5 turns is preferable. Further, it is conceivable to increase the fitting force by forming the screw depth of the male screw portion deeper and fitting the female screw portion more deeply, but in a metal bottle can made of aluminum, The screw depth of the male screw portion is determined by the limit of the workability, and it is generally preferable that the screw depth be 0.5 to 0.9 mm.
[0007]
The present invention has been made under such a background, and a bottle in which a cap is attached to a bottle can without being detached and flying even by an abnormal increase in internal pressure after re-closing. It is intended to provide cans and bottle cans with caps.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention proposes the following means.
The bottle can according to the present invention is characterized in that an easily crackable portion is formed at the bottom of the can which can be re-opened by attaching a cap.
In the bottle can of the present invention, since the easily cracked portion is formed at the bottom of the can of the bottle can, the cap comes off when the internal pressure of the bottle can with cap increases after being re-plugged with the contents remaining. Before the internal pressure rises to a pressure at which the internal pressure of the bottle can is increased, a gas is discharged due to the generation of a crack in the easily cracked portion, and the internal pressure of the bottle can with a cap decreases. In other words, by designing the bottle can so that a crack is generated in the easily cracked portion at a predetermined pressure, the easily cracked portion functions as a pressure regulating valve, and the gas generated inside the bottle can with cap is discharged from the crack to the outside. The discharge prevents the internal pressure from rising abnormally. This can prevent the cap from coming off the bottle can and flying. In addition, since the thickness of the bottom of the bottle can is thicker than the thickness of the can body, forming an easily cracked portion at the bottom of the can prevents the crack generated at the easily cracked portion from spreading. Can be.
[0009]
In addition, the bottle can according to the present invention is the bottle can, wherein the bottom of the can is provided with a dome recessed inside the can body, and the easy-to-crack portion is formed near the center of the dome. It is characterized by having.
In the bottle can of the present invention, since the dome portion which is recessed inside the can body is provided at the bottom of the can, when the internal pressure of the bottle can with cap rises after re-opening, the dome portion is caused to move outside the can body by this pressure. When the pressure further rises, a crack is generated in the easily cracked portion formed near the center of the dome portion. In other words, the location where the easily cracked portion is formed near the apex of the bulging portion due to buckling, so that the tensile force applied to the bottom of the can by the increase in internal pressure is the highest in the easily cracked portion, and the crack easily occurs. Cracks occur in the part. Thereby, it is possible to prevent the internal pressure from rising abnormally, and to prevent the cap from coming off the bottle can and flying.
[0010]
Further, the bottle can according to the present invention is the bottle can, wherein the bottom of the can is provided with a dome recessed inside the can body and an annular concave curved surface formed on a peripheral edge of the dome. In addition, the easy crack portion is formed in the annular concave curved surface portion.
In the bottle can of the present invention, since the easily cracked portion is formed in the annular concave curved surface portion formed on the peripheral edge of the dome portion, when the internal pressure of the bottle can with cap increases after re-closing, the easily cracked portion is removed. As a fulcrum, the annular concave curved portion is bent at an acute angle, the dome bulges out of the can body, and when the pressure further increases, a crack is generated in the easily cracked portion. In other words, the deformation of the easy-to-crack portion easily occurs due to the deformation caused by the buckling at the easy-to-crack portion. Thereby, it is possible to prevent the internal pressure from rising abnormally, and to prevent the cap from coming off the bottle can and flying.
[0011]
In addition, the bottle can with a cap according to the present invention is a bottle can with a cap that can be re-opened by attaching a cap to the bottle can, and a bottle can having any of the crack easily parts described above is used. It is characterized by having.
In the bottle can with a cap according to the present invention, since the bottle can having any of the above-described easily cracked portions is used, when the internal pressure rises after being re-plugged in a state where the contents remain, the easily cracked portion is used. When the cracks are generated, gas is discharged, and the internal pressure of the bottle can with a cap is reduced. Accordingly, it is possible to prevent the internal pressure of the bottle can with cap from abnormally increasing, and to prevent the cap from coming off the bottle can and flying.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A bottle can 1 with a cap as shown in FIG. 1 is hermetically sealed by attaching a cap 3 to a bottle can 2 made of an aluminum alloy. The bottle can 2 is provided with a reduced diameter portion 5 that is reduced in diameter upward from the cylindrical can body 4, and a cap portion 6 is provided above the reduced diameter portion 5. The base 6 is formed with a male screw 7, a bulge 8, and a curl 9. A top surface portion 10, a female screw portion 11, a pill fur proof portion 12, and a bridge portion 13 are formed on the cap 3, and a liner 14 as a sealing material is adhered to an inner surface of the top surface portion 10. The male screw part 7 of the bottle can 2 and the female screw part 11 of the cap 3 are fitted to each other, and the lower end of the pill fur proof part 12 is rolled under the bulging part 8. And the curl portion 9 and the liner 14 are tightly sealed to each other.
[0013]
In addition, a can bottom 15 is provided below the can body 4 of the bottle can 2, and the can bottom 15 has an annular convex portion 16 formed so as to continuously protrude downward from the can body 4, and an annular convex portion. A dome portion 17 formed so as to be recessed inside the can body 4 continuously from the portion 16 toward the inside in the radial direction is provided. At the boundary between the annular convex portion 16 and the dome portion 17, a counter sink R portion (annular concave curved surface portion) 18 formed by a curved surface having a smaller curvature than the curvature of the dome portion 17 is provided. That is, the countersink R portion 18 is a portion of an annular curved surface whose curvature changes from the inner wall 19 of the annular convex portion 16 toward the dome portion 17. Also, since the bottle can 2 is formed by drawing and ironing an aluminum alloy plate having a constant thickness, the thickness of the can bottom portion 15 having a small working degree is smaller than the thickness of the can body 4 having a large working degree. Is thick.
[0014]
FIG. 2 is a cross-sectional view of the vicinity of the bottom 15 of the bottle can 2, and FIG. 3 is a bottom view of the bottle can 2. In the figure, a portion where the thickness is thin near the center of the dome portion 17 is a score (easy cracking portion) 20, and a score is provided for the dome portion 17 having a plate thickness of 0.25 to 0.4 mm. Reference numeral 20 denotes a concave portion having a thickness of 0.1 mm or more. Specifically, the score 20 has a length of 5 to 10 mm, a width of 0.02 to 0.1 mm, and a depth of 0.05 to 0.3 mm. And has an X-shape. By partially forming the thin portion in this manner, the portion is formed so as to have a lower strength than other portions and to be easily cracked.
[0015]
In the bottle can 1 with a cap as described above, the female screw portion 11 is guided by the male screw portion 7 to move the cap 3 upward by rotating the cap 3 with respect to the bottle can 2, and the bulging portion 8 The bridge portion 13 is cut by the engagement of the pill fur proof portion 12 and the curl portion 9 and the liner 14 are separated and opened. Then, the cap 3 is put on the base portion 6, the female screw portion 11 and the male screw portion 7 are screwed together, and the liner 14 is brought into close contact with the curl portion 9, and the plug is re-plugged. If the contents remain in the bottle can 1 with cap thus re-plugged, the internal pressure of the bottle can 1 with cap may abnormally increase depending on the storage condition. A case where the internal pressure of the re-capped bottle can 1 with a cap rises is a case where the content is a fruit juice beverage or a beverage having a high sugar content and gas is generated by secondary fermentation when the content is in a high temperature state.
[0016]
When the internal pressure of the bottle can 1 with cap is abnormally increased in this manner, a buckling occurs in which the dome portion 17 formed to be recessed inside the can body 4 is deformed so as to bulge outward. In other words, the bulge bulges out like the deformed dome portion 17 'shown by the dashed line in FIG. 2, and the score 20 is located near the vertex thereof. Due to the buckling, the internal volume of the bottle can 1 with cap is increased, so that the internal pressure of the bottle can 1 with cap slightly decreases, but if the storage condition is not improved thereafter, the internal pressure will increase. Then, when the internal pressure rises to a predetermined value, a crack is generated in the score 20, and the internal gas is discharged from the crack. The internal pressure at which this crack occurs is set to be 0.2 to 0.3 MPa, which is lower than the pressure resistance value after reopening of the conventional bottle can with cap.
[0017]
As described above, when the internal pressure of the bottle can 1 with a cap rises, the score 20 provided on the can bottom 15 is cracked and the gas inside is discharged, so that the internal pressure is prevented from rising abnormally. can do. This can prevent the cap 3 from coming off and flying. In particular, since the bottom 15 of the can is made thicker than the can body 4, the crack generated in the score 20 does not spread, and the crack is generated only in the portion where the score 20 is formed. As a result, it is possible to avoid the risk of injury due to the end of a large crack or the like, which can be considered when a crack occurs at a place other than the score 20 and the crack spreads.
[0018]
The score 20 is formed near the center of the dome portion 17 and the score 20 is located near the apex of the dome portion 17 'deformed by buckling. The tensile force applied to the 'is highest at the position of score 20. That is, since the score 20 is formed at the position where the tensile force is most likely to be applied and the crack is likely to occur, the score 20 is surely cracked. Thereby, it is possible to reliably prevent the cap 3 from coming off and flying.
[0019]
FIG. 4 shows a modified example of the bottle can 1 with a cap in which a plurality of scores 21 are formed in the counter sink R portion 18. The scores 21 are arranged at equal intervals in four places in the countersink R portion 18 in a ring shape. The shape of the scores 21 is 5 to 10 mm in length, 0.02 to 0.1 mm in width, and 0.05 in depth. It is a groove-shaped recess of about 0.3 mm, which is slightly curved along the shape of the countersink R portion 18.
[0020]
When the internal pressure is abnormally increased in the bottle can 1 with cap in which the score 21 is formed, buckling occurs in the dome portion 17 and the counter sink R portion 18 is bent at an acute angle (see FIG. 2). At this time, since the score 21 is formed and the strength is low, the score 21 is easily bent with the score 21 as a fulcrum, and the strength of the score 21 is further reduced by the bending. That is, when the buckling occurs, the score 21 is easily cracked. Then, when the internal pressure further increases, a crack is generated in the score 21 and the gas inside is discharged. Thereby, it is possible to reliably prevent the cap 3 from coming off and flying.
[0021]
In the present embodiment, the easily cracked portion having the shape of score 20 and score 21 has been described. However, a score other than such a shape may be used. For example, a radial score may be provided near the center of dome portion 17. The score may be formed, or a score that is continuous over the entire circumference of the counter sink R section 18 or a score in the form of a broken line may be formed. Further, by using the bottle can 2 in which the score 20 and the score 21 are both formed, it is possible to more reliably prevent the cap 3 from coming off and flying. In addition, in addition to the shape of a groove-shaped concave portion such as a score as an easy-to-crack portion, a portion having low strength is partially formed without changing the thickness by using the anisotropy of the material to form the easily-crackable portion. Is also good. In addition, the bottle can 2 in which the can body 4 and the can bottom 15 are integrally formed has been described, but the present invention may be applied to a bottle can formed by winding the can bottom around the can body. Good.
[0022]
【The invention's effect】
As described above, according to the bottle can according to the present invention, since the easily cracked portion is formed at the bottom of the can of the bottle can, the crack can occur before the internal pressure of the bottle can reopened with the cap rises abnormally. The internal gas can be exhausted by the generation of cracks in the easy part. Thus, it is possible to prevent the cap from coming off the bottle can and flying due to an abnormal increase in the internal pressure. In addition, the thickness of the can bottom is thicker than the thickness of the can body of the bottle can, and by forming an easily cracked portion at the bottom of the can, it is possible to prevent the crack generated at the easily cracked portion from spreading. it can.
[0023]
In addition, a dome that is recessed inside the can body is provided at the bottom of the can, and an easy crack is formed near the center of the dome, so the internal pressure of the bottle can that has been re-sealed with a cap increases. Therefore, when buckling occurs in the dome portion, the easily cracked portion is located at the position where the tensile force is highest, and the crack can be reliably generated in the easily cracked portion. Thereby, it is possible to prevent the internal pressure from rising abnormally and to prevent the cap from coming off and flying.
[0024]
In addition, since an easily cracked portion is formed in the annular concave curved surface portion formed on the peripheral edge portion of the dome portion of the bottle can, buckling occurred in the dome portion due to an increase in internal pressure of the bottle can re-plugged with the cap. In this case, the annular concave curved surface portion is bent at an acute angle with the easily crackable portion as a fulcrum, whereby the strength of the easily cracked portion is reduced, and a crack can be reliably generated in the easily cracked portion. Thereby, it is possible to prevent the internal pressure from rising abnormally, and to prevent the cap from coming off and flying.
[0025]
Further, according to the bottle can with a cap according to the present invention, since the bottle can having any of the easily cracked portions described above is used, a crack is generated in the easily cracked portion due to an increase in internal pressure, and the bottle can with a cap is formed. The gas inside can be exhausted. Thus, it is possible to prevent the internal pressure of the bottle can with cap from rising abnormally, and to prevent the cap from coming off and flying.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional side view of a bottle can with cap according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the vicinity of the bottom of the bottle can with a cap.
FIG. 3 is a bottom view of the bottle can with cap.
FIG. 4 is a bottom view of a bottle can with cap showing a modification of the score.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 Bottle can with cap 2 Bottle can 3 Cap 4 Can body 15 Can bottom 17 Dome 18 Counter sink R (circular concave curved surface)
20, 21 Score (Easy crack)

Claims (4)

In a bottle can that can be re-opened by attaching a cap,
A bottle can having an easily crackable portion formed at the bottom of the can. The bottle can according to claim 1,
A bottle can provided with a dome recessed inside the can body at the bottom of the can, and the easy-to-crack portion formed near the center of the dome. A bottle can according to claim 1 or claim 2,
At the bottom of the can, a dome recessed inside the can body and an annular concave curved surface formed at the peripheral edge of the dome are provided, and the crack easy portion is formed at the annular concave curved surface. A bottle can characterized by the following. In a bottle can with a cap that can be re-opened by attaching a cap to the bottle can,
A bottle can with a cap, wherein the bottle can having the easily crackable portion according to any one of claims 1 to 3 is used.

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