JP4972461B2 - Container with easily deformable bottom end - Google Patents

Description

  The present invention relates to a container capable of maintaining an upright state without being damaged even when the internal pressure rises to a predetermined value or more or the volume of the contents expands to a predetermined amount or more.

  Conventionally, in a metal container filled and sealed with contents such as beverages, it has been known that when the internal pressure of the container rises abnormally, a part of the container may be deformed by the internal pressure of the container. Patent Document 1 describes a container that can maintain an upright state even when such deformation occurs on the bottom wall of the container. Briefly explaining the configuration described in Patent Document 1, the bottom wall of the container body has an annular panel portion and a hollow recessed inwardly in the center, and the bottom wall expands outward due to the internal pressure of the container. In this case, the edge of the recess becomes the base on which the container sits, and the container can be supported upright.

Japanese Patent Publication No.54-35819

  However, in the configuration described in Patent Document 1, since the edge of the recess itself that deforms when the internal pressure rises becomes the base that the container sits on, the deformation does not occur so that the entire edge protrudes evenly. There is a possibility that the container cannot be stably erected.

  The present invention has been made against the background of the above circumstances, and an object thereof is to provide a container that can be stably maintained in an upright state even when deformation occurs due to an increase in internal pressure or the like. Is.

  In order to achieve the above object, the invention of claim 1 is characterized in that a first grounding portion located at an outer end in the axial direction is provided at the bottom, and a first grounding portion located inward in the axial direction from the first grounding portion. A second grounding portion and an easily deformable portion that connects the first grounding portion and the second grounding portion, and when the internal pressure rises to a predetermined value or more or the volume of the contents expands to a predetermined amount or more. The easily deformable portion is deformed, and the second grounding portion protrudes so as to be located outward in the axial direction from the first grounding portion, and is configured to be held upright by the second grounding portion. A container having a bottom end that can be easily deformed.

  The invention of claim 2 is the easily deformable feature of the invention of claim 1, wherein the easily deformable portion has two or more bent portions and is formed so that the bottom wall surface is folded. This is a container having a bottom end.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the bottom portion is a ring having a substantially U-shaped longitudinal section that is recessed inward in the axial direction between the first grounding portion and the easily deformable portion. A first bent portion having a groove portion, wherein the easily deformable portion is formed continuously with the inner peripheral end portion of the annular groove portion and is convex outward in the axial direction; and an inner peripheral end portion of the first bent portion A first inclined wall extending inward in the axial direction and inward in the radial direction, a second bent portion formed continuously from the inner peripheral end of the first inclined wall and recessed inward in the axial direction, A second inclined wall extending outward in the axial direction and inward in the radial direction from an inner peripheral end portion of the second bent portion and formed continuously with the second grounding portion, and The grounding portion has a third bent portion that protrudes outward in the axial direction, and the radius of curvature of the first bent portion and the second bent portion is half the curvature of the annular groove portion and the third bent portion. A container having a readily deformable bottom end, characterized in that it is set larger than the.

  According to the first aspect of the present invention, an easily deformable portion that connects the first grounding portion and the second grounding portion is formed at the bottom of the container, and the internal pressure of the container rises above a predetermined value or the volume of the content is a predetermined amount. When the internal pressure of the container rises to a predetermined value or more or the volume of the contents expands to a predetermined amount or more by deforming the easily deformable portion and causing the second grounding portion to protrude when expanded above, the second grounding portion Since the internal volume of the container can be increased and the internal pressure of the container can be lowered by the protrusion of the container, the container cap blows off the bottom of the bottom of the container when the easily deformable part is deformed and the volume of the contents. By setting the pressure lower than the pressure and volume at which the lid tightening part is destroyed, it is possible to prevent the container cap from blowing off and the bottom lid tightening part from being destroyed, By not deforming the part itself, It can be upright vessel stably by the two ground part.

  According to the invention of claim 2, the easily deformable portion has two or more bent portions, and the bottom wall surface is formed to be folded, so that the internal pressure of the container rises above a predetermined value or the contents When the volume expands to a predetermined amount or more, the inner volume of the container is easily increased by deforming so that the folding part is extended by pressure, and the second grounding part is placed outside the first grounding part in the container axial direction. It can protrude so that it may be located in the direction.

  According to the invention of claim 3, by setting the curvature radii of the first bent portion and the second bent portion formed in the easily deformable portion to be larger than the curvature radii of the annular groove portion and the third bent portion, the first bent portion The strength of the bent portion and the second bent portion can be made smaller than the strength of the annular groove portion and the third bent portion, and when the internal pressure of the container rises above a predetermined value or the volume of the contents expands above a predetermined amount, the second bent portion The one bent portion and the second bent portion can be easily opened by pressure, and thereby the second grounding portion can be reliably projected so as to be located outward of the first grounding portion in the container axis direction.

  The container of the present invention is a metal can container, a synthetic resin bottle, or the like, and is configured to stand upright by grounding a bottom wall provided at one end of the body. In FIG. 1 and FIG. 2, as an example, a bottle mold formed from a metal plate material in which a well-known metal plate for containers such as an aluminum alloy plate or a surface-treated steel plate is coated with a protective coating such as a coating film or a resin film. A can container 1 is shown. This can container 1 has a can body 2, a shoulder 3 having a reduced diameter at one end of the can body 2, a diameter that is continuous to the shoulder 3 and further reduced to a smaller diameter, and a threaded portion is formed. The mouth / neck portion 4, the cap 5 attached to the mouth / neck portion 4 by a roll-on method or the like, and the bottom lid 6 wound and fixed to the other end of the can body 2 are provided.

  The structure in which the bottom cover 6 is attached to the can body 2 is a conventionally known structure by double winding, a flange portion formed at the other end of the can body 2, and the outer periphery of the bottom cover 6 The flange part formed in the part is fixed by double winding. In this way, an annular winding portion 7 is formed at the bottom of the can container 1. This winding part 7 is a grounding part that comes into contact with a floor, a table or the like when the can container 1 is erected, and this winding part 7 corresponds to the first grounding part in the present invention.

  A portion of the bottom lid 6 that is continuous to the inner peripheral side of the tightening portion 7 is a chuck wall portion 8 that is recessed inward in the axial direction of the can container 1 through the chuck wall portion 8. An annular groove portion (so-called counter sink portion) 9 having a substantially U-shaped longitudinal section is formed. The inclined wall 10 on the inner peripheral side of the annular groove portion 9 is bent and bent back before the end portion of the can body 2 (opening end of the winding fastening portion 7), and the folded portion of the can container 1 The first bent portion 11 is convex outward in the axial direction.

  The portion connected inward in the radial direction from the first bent portion 11 extends inward in the axial direction of the can container 1 and inward in the radial direction of the can container 1, and becomes the first inclined wall 12. ing. The first inclined wall 12 is bent and bent at a position beyond or near the bottom of the annular groove 9 (the inner end in the axial direction of the can container 1). Accordingly, the first inclined wall 12 and a portion connected to the first inclined wall 12 form a second bent portion 13 that is recessed inward in the axial direction of the can container 1. The portion connected to the first inclined wall 12 via the second bent portion 13 is outward from the inner peripheral end of the second bent portion 13 in the axial direction of the can container 1 and in the radial direction of the can container 1. The second inclined wall 14 extends inward.

  The second inclined wall 14 is bent and bent at substantially the same position as or in the vicinity of the first bent portion 11 in the axial direction of the can container 1, and is thus connected to the inner peripheral end of the second inclined wall 14. The portion is convex outward in the axial direction of the can container 1, and an annular third bent portion 15 is formed here. The portion connected to the second inclined wall 14 via the third bent portion 15 is inward in the axial direction of the can container 1 from the inner peripheral end portion of the third bent portion 15 and in the radial direction of the can container 1. It extends inward and forms a third inclined wall 16. The portion connected to the third inclined wall 16 inward in the radial direction of the can container 1 is a curved surface that is recessed in the shape of a circular arc in the axial direction of the can container 1, and this portion is A dome portion 17 is formed. And in the radial direction of the can container 1 in the radial direction of the annular groove portion 9 at the bottom of the can container 1, the can container 1 is in a normal state in the axial direction of the can container 1 rather than the tip of the winding portion 7. It is set to be located inward. In other words, the front end of the tightening portion 7 is configured to be positioned at the outermost end in the axial direction of the can container 1.

  In the can container 1 according to the present invention, the first bent portion 11, the second bent portion 13, the first inclined wall 12, and the second inclined wall 14 are processed by folding the wall surface of the bottom lid 6 that is the bottom portion thereof. Is formed. The portion formed by the first bent portion 11, the second bent portion 13, the first inclined wall 12, and the second inclined wall 14 is weaker or less rigid than the other portions of the can container 1. Therefore, this portion is the easily deformable portion 18. That is, the easily deformable portion 18 is acted on by a load that increases the internal pressure of the can container 1 to a predetermined value or more, or expands the volume of the contents to a predetermined amount or more and presses the bottom lid 6 outward. In this case, the cap 5 is deformed in preference to the mounting portion of the cap 5, the tightening portion 7, the other portion of the bottom cover 6, and the like. For example, when a load that presses the bottom lid 6 outward in the axial direction of the can 1 is generated due to an increase in internal pressure or expansion of contents, the curvatures of the first bent portion 11 and the second bent portion 13 are generated. The first bent portion 11, the first inclined wall 12, the second bent portion 13, and the second inclined wall 14 that are formed so as to have a larger radius and are folded outwardly in the axial direction of the can container 1 and This is a deformation extending inward in the radial direction of the can container 1. The state after the deformation is shown in FIG.

  When such deformation occurs, the third bent portion 15 and the third inclined wall 16 are located inwardly in the radial direction of the can container 1 with respect to the easily deformable portion 18 and stronger than the easily deformable portion 18. The dome portion 17 is displaced so as to bulge outward in the axial direction of the can container 1 while maintaining its shape. In the can container 1 according to the present invention, when the third bent portion 15 bulges, the tip of the third bent portion 15 protrudes outward in the axial direction of the can container 1 from the tip of the winding fastening portion 7. When the can container 1 is set upright, the third bent portion 15 serves as a grounding portion instead of the winding tightening portion 7. Therefore, the third bent portion 15 corresponds to the second grounding portion in the present invention.

The can container 1 according to the present invention is not deformed by an internal pressure (about 61.8 N / cm ² ) that rises in the heat sterilization process of the contents after filling the contents, and is in a higher pressure range 68. It can be configured such that the easily deformable portion 18 is deformed when it is raised to a range of .6 to 88.3 N / cm ² . Specifically, the bottom lid 6 constituting the bottom of the can container 1 is formed of an aluminum alloy plate having a plate thickness of 0.20 to 0.35 mm and a proof stress of 196 to 343 N / mm ² , as shown in FIG. Further, the diameter (D) of the center position of the lower end (tip) of the winding tightening portion 7 is 50 to 70 mm, and the diameter (d) of the lower end (tip) position of the third bent portion 15 is the lower end position of the winding tightening portion 7. The range is 60 to 80% of the diameter (D). Further, the radii of curvature r2 and r3 of the first bent portion 11 and the second bent portion 13 are made larger than the radius of curvature r4 of the third bent portion 15, whereby the rigidity of the first bent portion 11 and the second bent portion 13 is increased. Is made lower than the rigidity of the annular groove portion 9 and the third bent portion 15. Specifically, the radius of curvature r1 of the bent portion of the annular groove 9 is 0.3 to 1.0 mm, the radius of curvature r2 of the first bent portion 11 is 0.5 to 1.5 mm, and the radius of curvature of the second bent portion 13 is. r3 is set to 0.5 to 1.5 mm, and the radius of curvature r4 of the third bent portion 15 is set to 0.3 to 1.3 mm. Further, the radius of curvature r5 of the dome portion 17 is set to 25 mm or more.

  Furthermore, the inclination angles θ2 and θ3 of the first inclined wall 12 and the second inclined wall 14 with respect to the horizontal direction are based on the inclination angles θ1 and θ4 of the inner inclined wall 10 and the third inclined wall 16 of the annular groove portion 9 with respect to the horizontal direction. Is set to be small, and when an outward force in the axial direction of the can container 1 is applied to the bottom portion (bottom lid 6) of the can container 1, the outward direction in the axial direction of the can container 1 It is easy to deform. Specifically, the inclination angle θ1 with respect to the horizontal direction of the inner inclined wall 10 of the annular groove portion 9 is 60 to 85 °, the inclination angle θ2 with respect to the horizontal direction of the first inclined wall 12 is 55 to 82 °, and the second inclined wall 14 The inclination angle θ3 with respect to the horizontal direction is 55 to 82 °, and the inclination angle θ4 with respect to the horizontal direction of the third inclined wall 16 is 65 to 85 °. The distance L1 from the outer surface of the upper end portion of the dome portion 17 to the outer surface of the lower end of the third bent portion 15 is 7 mm or more, the distance L2 from the upper end to the lower end on the outer surface side of the dome portion 17 is 6 mm or more, The distance L3 from the lower end of 11 to the upper end of the second bent portion 13 is set to 2 to 6 mm, and the distance L4 from the upper end of the second bent portion 13 to the lower end of the third bent portion 15 is set to 2 to 6 mm. Here, when the diameter d of the tip (lower end) of the third bent portion 15 is smaller than 60% of the diameter D of the tip (lower end) of the winding fastening portion 7 that is the first grounding portion, the can container 1 is made to stand upright. The leg portion that supports the can container 1 becomes smaller when the can container 1 is placed, and there is a possibility that the stability may deteriorate when the can container 1 is erected. On the other hand, when the diameter d of the tip (lower end) of the third bent portion 15 that is the second grounding portion is larger than 80% of the diameter D of the tip (lower end) of the tightening portion 7 that is the first grounding portion, The distance between the first grounding portion and the second grounding portion in the radial direction of the can container 1 becomes narrow, and when the easily deformable portion 18 is molded, there is a possibility that the bent portion or the like is tightly formed and cracking or constriction occurs during the molding process. is there.

By adopting the above configuration, the easily deformable portion 18 is suitably deformed within an internal pressure range of 68.6 to 88.3 N / cm ² , and the second grounding portion bulges outward in the axial direction of the can container 1. Can be made. And the can container 1 can be made to stand stably at the time of protrusion of the 3rd bending part 15 which is a 2nd earthing | grounding part.

(Concrete example)
The simulation was performed under the following conditions. In an aluminum alloy can container having a cap, a can body, and a bottom cover, a bottom cover constituting the bottom of the can container is formed of an aluminum alloy plate having a plate thickness of 0.29 mm and a proof stress of 304 N / mm ² . The lower end of the fastening portion is 62 mm, the lower end diameter of the third bent portion is 44 mm, the radius of curvature of the annular groove is 0.45 mm, the radius of curvature of the first bent portion is 0.75 mm, and the radius of curvature of the second bent portion is 0. 75mm, radius of curvature of the third bent portion is 0.60mm, radius of curvature of the dome portion is 31mm, angle of inclination of the inner inclined wall of the annular groove portion with respect to the horizontal direction is 82.5 °, angle of inclination of the first inclined wall with respect to the horizontal direction 63 °, the inclination angle of the second inclined wall with respect to the horizontal direction is 77 °, the inclination angle of the third inclined wall with respect to the horizontal direction is 82.5 °, and from the upper end on the outer surface side of the dome portion to the lower end of the third bent portion. The distance is 10 mm, The distance from the upper end to the lower end on the outer surface side of the arm portion is 8 mm, the distance from the lower end of the first bent portion to the upper end of the second bent portion is 4.5 mm, and the upper end of the second bent portion to the lower end of the third bent portion Was set to 4 mm.

When the internal pressure is gradually increased, when the internal pressure reaches 69.9 N / cm ² , the first bent portion and the second bent portion extend, and the second grounding portion protrudes outward in the axial direction of the can container. Deformation occurred. The amount of protrusion of the second grounding portion was almost uniform over the entire circumference, and therefore the can container could be held upright by the second grounding portion.

  As described above, in the container according to the present invention, the winding portion (first grounding portion) positioned at the outer end in the axial direction at the bottom portion, and the third portion positioned inward in the axial direction from the winding portion. A bent portion (second grounding portion) and an easily deformable portion that connects the tightened portion and the third bent portion are formed, and the internal pressure of the container rises to a predetermined value or more, or the volume of the content exceeds a predetermined amount The easily deformable portion is deformed when expanded, and the tip of the third bent portion can be protruded so as to be located outward of the end of the container axial direction from the tip of the tightening portion while maintaining its shape. Therefore, when the internal pressure of the container rises above a predetermined value or the volume of the contents expands beyond a predetermined amount, the internal volume of the container is increased by the protrusion of the third bent portion, and the pressure applied to the container is reduced. Therefore, the value of the internal pressure of the container and the volume of the contents when the easily deformable part is deformed are set lower than the pressure and volume at which the cap of the container blows off or the tightening part of the bottom lid is broken. By doing so, it is possible to suppress the container cap from being blown off and the winding part and the can body from being destroyed, and the third bent part itself is not deformed, thereby stabilizing the container by the third bent part. Can be upright.

  The container of the present invention does not have to be a metal can container in which the bottom lid is wrapped around the can body as described above, and a single metal plate is drawn and ironed to form a can body and a bottom portion. A first grounding portion having a substantially U-shaped vertical section that protrudes outward in the container axial direction, which becomes a grounding portion in a normal state, is formed at the bottom of a metal can container that is integrally formed with the first grounding portion. An annular groove having a substantially U-shaped longitudinal cross section that is connected to the inner peripheral end of the container and is recessed inward in the container axial direction is formed, and an easily deformable part is formed continuously to the inner peripheral end of the inner inclined wall of the annular groove. Even if the second grounding portion formed continuously from the inner peripheral end portion of the easily deformable portion and set so as to bulge from the tip of the first grounding portion when the internal pressure rises, etc. Good. Moreover, the same 1st earthing | grounding part, a deformation | transformation easy part, and the 2nd earthing | grounding part may be formed in the bottom part of the container which carried out the synthetic resin blow molding like a PET bottle. In addition, the first bent portion and the second bent portion, which are the easily deformable portions that are deformed so as to return to the flat state from the bent state when the internal pressure rises, do not need to be single as described above, A part may be formed in double or more, and a plurality of easily deformable parts may be provided. In that case, by changing the strength and rigidity step by step for each easy-to-deform part, and deforming one easy-to-deform part over the entire circumference, the next easy-to-deform part is deformed, so that multiple deformations Each of the easy portions can be uniformly extended and deformed, and the increase in the container internal pressure can be alleviated step by step.

It is the front view made into the partial cross section which shows an example of this invention. It is the front view made into the partial cross section which shows the state after a deformation | transformation arises in the bottom cover. It is a partial expanded sectional view for demonstrating the dimension and angle of each part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Can container, 2 ... Can trunk, 3 ... Shoulder part, 4 ... Mouth and neck part, 5 ... Cap, 6 ... Bottom cover, 7 ... Winding part, 8 ... Chuck wall part, 9 ... Annular groove part (counter sink part) ), 10 ... inclined wall, 11 ... first bent portion, 12 ... first inclined wall, 13 ... second bent portion, 14 ... second inclined wall, 15 ... third bent portion, 16 ... third inclined wall, 17 ... dome part, 18 ... deformable part.

Claims (3)

  A first grounding portion located at the outer end in the axial direction at the bottom, a second grounding portion located inward in the axial direction from the first grounding portion, the first grounding portion and the second grounding portion An easy-to-deform portion that connects the first and second deformable portions to each other when the internal pressure rises to a predetermined value or more, or the volume of the contents expands to a predetermined amount or more. A container having an easily deformable bottom end that is configured to protrude outwardly in the axial direction from one grounding portion and to be held upright by the second grounding portion.   The container having an easily deformable bottom end according to claim 1, wherein the easily deformable portion has two or more bent portions, and is formed so that a bottom wall surface is folded.   The bottom portion has an annular groove portion having a substantially U-shaped longitudinal section that is recessed inward in the axial direction between the first grounding portion and the easily deformable portion, and the easily deformable portion is an inner portion of the annular groove portion. A first bent portion that is continuously formed at the peripheral end portion and is convex outward in the axial direction, and a first bent portion extending inward in the axial direction and inward in the radial direction from the inner peripheral end portion of the first bent portion. An inclined wall, a second bent portion formed continuously from the inner peripheral end of the first inclined wall and recessed inward in the axial direction, and outward in the axial direction from the inner peripheral end of the second bent portion And a second inclined wall extending inward in the radial direction and continuously formed on the second grounding portion, wherein the second grounding portion protrudes outward in the axial direction. The curvature radius of said 1st bending part and said 2nd bending part is set larger than the curvature radius of an annular groove part and said 3rd bending part, It is characterized by the above-mentioned. A container having a readily deformable bottom end according to 1 or 2.

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